fix RADIUS indexing (should have 16K entries with 64 sockets)
[l2tpns.git] / l2tpns.c
index 87ff163..e0e3cf2 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -1,10 +1,10 @@
 // L2TP Network Server
 // Adrian Kennard 2002
-// Copyright (c) 2003, 2004 Optus Internet Engineering
+// Copyright (c) 2003, 2004, 2005 Optus Internet Engineering
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.49 2004/11/16 07:54:32 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.104 2005/05/16 04:51:16 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -19,6 +19,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.49 2004/11/16 07:54:32 bodea Exp
 #include <sys/mman.h>
 #include <netdb.h>
 #include <netinet/in.h>
+#include <netinet/ip6.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -54,7 +55,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.49 2004/11/16 07:54:32 bodea Exp
 #endif /* BGP */
 
 // Globals
-struct configt *config = NULL; // all configuration
+configt *config = NULL;                // all configuration
 int tunfd = -1;                        // tun interface file handle. (network device)
 int udpfd = -1;                        // UDP file handle
 int controlfd = -1;            // Control signal handle
@@ -62,25 +63,31 @@ int clifd = -1;                     // Socket listening for CLI connections.
 int snoopfd = -1;              // UDP file handle for sending out intercept data
 int *radfds = NULL;            // RADIUS requests file handles
 int ifrfd = -1;                        // File descriptor for routing, etc
+int ifr6fd = -1;               // File descriptor for IPv6 routing, etc
+static int rand_fd = -1;       // Random data source
 time_t basetime = 0;           // base clock
 char hostname[1000] = "";      // us.
-static u32 sessionid = 0;      // session id for radius accounting
+static int tunidx;             // ifr_ifindex of tun device
 static int syslog_log = 0;     // are we logging to syslog
-static FILE *log_stream = NULL;        // file handle for direct logging (i.e. direct into file, not via syslog).
+static FILE *log_stream = 0;   // file handle for direct logging (i.e. direct into file, not via syslog).
 extern int cluster_sockfd;     // Intra-cluster communications socket.
-u32 last_id = 0;               // Last used PPP SID. Can I kill this?? -- mo
+uint32_t last_id = 0;          // Unique ID for radius accounting
 
 struct cli_session_actions *cli_session_actions = NULL;        // Pending session changes requested by CLI
 struct cli_tunnel_actions *cli_tunnel_actions = NULL;  // Pending tunnel changes required by CLI
 
 static void *ip_hash[256];     // Mapping from IP address to session structures.
+struct ipv6radix {
+       int sess;
+       struct ipv6radix *branch;
+} ipv6_hash[256];              // Mapping from IPv6 address to session structures.
 
 // Traffic counters.
-static u32 udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
-static u32 eth_rx = 0, eth_rx_pkt = 0;
-u32 eth_tx = 0;
+static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
+static uint32_t eth_rx = 0, eth_rx_pkt = 0;
+uint32_t eth_tx = 0;
 
-static u32 ip_pool_size = 1;           // Size of the pool of addresses used for dynamic address allocation.
+static uint32_t ip_pool_size = 1;      // Size of the pool of addresses used for dynamic address allocation.
 time_t time_now = 0;                   // Current time in seconds since epoch.
 static char time_now_string[64] = {0}; // Current time as a string.
 static char main_quit = 0;             // True if we're in the process of exiting.
@@ -88,24 +95,26 @@ linked_list *loaded_plugins;
 linked_list *plugins[MAX_PLUGIN_TYPES];
 
 #define membersize(STRUCT, MEMBER) sizeof(((STRUCT *)0)->MEMBER)
-#define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(struct configt, MEMBER), membersize(struct configt, MEMBER), TYPE }
+#define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(configt, MEMBER), membersize(configt, MEMBER), TYPE }
 
-struct config_descriptt config_values[] = {
+config_descriptt config_values[] = {
        CONFIG("debug", debug, INT),
        CONFIG("log_file", log_filename, STRING),
        CONFIG("pid_file", pid_file, STRING),
+       CONFIG("random_device", random_device, STRING),
        CONFIG("l2tp_secret", l2tpsecret, STRING),
-       CONFIG("primary_dns", default_dns1, IP),
-       CONFIG("secondary_dns", default_dns2, IP),
-       CONFIG("save_state", save_state, BOOL),
-       CONFIG("primary_radius", radiusserver[0], IP),
-       CONFIG("secondary_radius", radiusserver[1], IP),
+       CONFIG("primary_dns", default_dns1, IPv4),
+       CONFIG("secondary_dns", default_dns2, IPv4),
+       CONFIG("primary_radius", radiusserver[0], IPv4),
+       CONFIG("secondary_radius", radiusserver[1], IPv4),
        CONFIG("primary_radius_port", radiusport[0], SHORT),
        CONFIG("secondary_radius_port", radiusport[1], SHORT),
        CONFIG("radius_accounting", radius_accounting, BOOL),
+       CONFIG("radius_interim", radius_interim, INT),
        CONFIG("radius_secret", radiussecret, STRING),
-       CONFIG("bind_address", bind_address, IP),
-       CONFIG("peer_address", peer_address, IP),
+       CONFIG("radius_authtypes", radius_authtypes_s, STRING),
+       CONFIG("bind_address", bind_address, IPv4),
+       CONFIG("peer_address", peer_address, IPv4),
        CONFIG("send_garp", send_garp, BOOL),
        CONFIG("throttle_speed", rl_rate, UNSIGNED_LONG),
        CONFIG("throttle_buckets", num_tbfs, INT),
@@ -117,10 +126,12 @@ struct config_descriptt config_values[] = {
        CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
        CONFIG("lock_pages", lock_pages, BOOL),
        CONFIG("icmp_rate", icmp_rate, INT),
-       CONFIG("cluster_address", cluster_address, IP),
+       CONFIG("packet_limit", max_packets, INT),
+       CONFIG("cluster_address", cluster_address, IPv4),
        CONFIG("cluster_interface", cluster_interface, STRING),
        CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
        CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
+       CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
        { NULL, 0, 0, 0 },
 };
 
@@ -141,38 +152,42 @@ static char *plugin_functions[] = {
 
 #define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
 
+// Counters for shutdown sessions
+static sessiont shut_acct[8192];
+static sessionidt shut_acct_n = 0;
+
 tunnelt *tunnel = NULL;                        // Array of tunnel structures.
 sessiont *session = NULL;              // Array of session structures.
-sessioncountt *sess_count = NULL;      // Array of partial per-session traffic counters.
+sessionlocalt *sess_local = NULL;      // Array of local per-session counters.
 radiust *radius = NULL;                        // Array of radius structures.
 ippoolt *ip_address_pool = NULL;       // Array of dynamic IP addresses.
+ip_filtert *ip_filters = NULL; // Array of named filters.
 static controlt *controlfree = 0;
 struct Tstats *_statistics = NULL;
 #ifdef RINGBUFFER
 struct Tringbuffer *ringbuffer = NULL;
 #endif
 
-static void cache_ipmap(ipt ip, int s);
-static void uncache_ipmap(ipt ip);
+static void cache_ipmap(in_addr_t ip, int s);
+static void uncache_ipmap(in_addr_t ip);
+static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s);
 static void free_ip_address(sessionidt s);
-static void dump_acct_info(void);
+static void dump_acct_info(int all);
 static void sighup_handler(int sig);
 static void sigalrm_handler(int sig);
 static void sigterm_handler(int sig);
 static void sigquit_handler(int sig);
 static void sigchild_handler(int sig);
-static void read_state(void);
-static void dump_state(void);
-static void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
+static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response);
 static void update_config(void);
 static void read_config_file(void);
 static void initplugins(void);
-static void add_plugin(char *plugin_name);
-static void remove_plugin(char *plugin_name);
+static int add_plugin(char *plugin_name);
+static int remove_plugin(char *plugin_name);
 static void plugins_done(void);
-static void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
 static tunnelidt new_tunnel(void);
-static int unhide_avp(u8 *avp, tunnelidt t, sessionidt s, u16 length);
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
 
 // return internal time (10ths since process startup)
 static clockt now(void)
@@ -185,7 +200,7 @@ static clockt now(void)
 // work out a retry time based on try number
 // This is a straight bounded exponential backoff.
 // Maximum re-try time is 32 seconds. (2^5).
-clockt backoff(u8 try)
+clockt backoff(uint8_t try)
 {
        if (try > 5) try = 5;                  // max backoff
        return now() + 10 * (1 << try);
@@ -193,12 +208,11 @@ clockt backoff(u8 try)
 
 
 //
-// Log a debug message.  Typically called vias LOG macro
+// Log a debug message.  Typically called via the LOG macro
 //
-void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...)
+void _log(int level, sessionidt s, tunnelidt t, const char *format, ...)
 {
        static char message[65536] = {0};
-       static char message2[65536] = {0};
        va_list ap;
 
 #ifdef RINGBUFFER
@@ -211,7 +225,6 @@ void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format,
                                ringbuffer->head = 0;
 
                ringbuffer->buffer[ringbuffer->tail].level = level;
-               ringbuffer->buffer[ringbuffer->tail].address = address;
                ringbuffer->buffer[ringbuffer->tail].session = s;
                ringbuffer->buffer[ringbuffer->tail].tunnel = t;
                va_start(ap, format);
@@ -223,32 +236,27 @@ void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format,
        if (config->debug < level) return;
 
        va_start(ap, format);
+       vsnprintf(message, sizeof(message), format, ap);
+
        if (log_stream)
-       {
-               vsnprintf(message2, 65535, format, ap);
-               snprintf(message, 65535, "%s %02d/%02d %s", time_now_string, t, s, message2);
-               fprintf(log_stream, "%s", message);
-       }
+               fprintf(log_stream, "%s %02d/%02d %s", time_now_string, t, s, message);
        else if (syslog_log)
-       {
-               vsnprintf(message2, 65535, format, ap);
-               snprintf(message, 65535, "%02d/%02d %s", t, s, message2);
-               syslog(level + 2, message); // We don't need LOG_EMERG or LOG_ALERT
-       }
+               syslog(level + 2, "%02d/%02d %s", t, s, message); // We don't need LOG_EMERG or LOG_ALERT
+
        va_end(ap);
 }
 
 void _log_hex(int level, const char *title, const char *data, int maxsize)
 {
        int i, j;
-       const u8 *d = (const u8 *)data;
+       const uint8_t *d = (const uint8_t *) data;
 
        if (config->debug < level) return;
 
        // No support for _log_hex to syslog
        if (log_stream)
        {
-               _log(level, 0, 0, 0, "%s (%d bytes):\n", title, maxsize);
+               _log(level, 0, 0, "%s (%d bytes):\n", title, maxsize);
                setvbuf(log_stream, NULL, _IOFBF, 16384);
 
                for (i = 0; i < maxsize; )
@@ -289,6 +297,72 @@ void _log_hex(int level, const char *title, const char *data, int maxsize)
        }
 }
 
+// initialise the random generator
+static void initrandom(char *source)
+{
+       static char path[sizeof(config->random_device)] = "*undefined*";
+
+       // reinitialise only if we are forced to do so or if the config has changed
+       if (source && !strncmp(path, source, sizeof(path)))
+               return;
+
+       // close previous source, if any
+       if (rand_fd >= 0) close(rand_fd);
+
+       rand_fd = -1;
+
+       if (source)
+       {
+               // register changes
+               snprintf(path, sizeof(path), "%s", source);
+
+               if (*path == '/')
+               {
+                       rand_fd = open(path, O_RDONLY|O_NONBLOCK);
+                       if (rand_fd < 0)
+                               LOG(0, 0, 0, "Error opening the random device %s: %s\n",
+                                       path, strerror(errno));
+               }
+       }
+
+       // no source: seed prng
+       {
+               unsigned seed = time_now ^ getpid();
+               LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
+               srand(seed);
+       }
+}
+
+// fill buffer with random data
+void random_data(uint8_t *buf, int len)
+{
+       int n = 0;
+
+       CSTAT(random_data);
+       if (rand_fd >= 0)
+       {
+               n = read(rand_fd, buf, len);
+               if (n >= len) return;
+               if (n < 0)
+               {
+                       if (errno != EAGAIN)
+                       {
+                               LOG(0, 0, 0, "Error reading from random source: %s\n",
+                                       strerror(errno));
+
+                               // fall back to rand()
+                               initrandom(0);
+                       }
+
+                       n = 0;
+               }
+       }
+
+       // append missing data
+       while (n < len)
+               // not using the low order bits from the prng stream
+               buf[n++] = (rand() >> 4) & 0xff;
+}
 
 // Add a route
 //
@@ -298,7 +372,7 @@ void _log_hex(int level, const char *title, const char *data, int maxsize)
 //
 // 'ip' and 'mask' must be in _host_ order.
 //
-static void routeset(sessionidt s, ipt ip, ipt mask, ipt gw, u8 add)
+static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
 {
        struct rtentry r;
        int i;
@@ -310,25 +384,23 @@ static void routeset(sessionidt s, ipt ip, ipt mask, ipt gw, u8 add)
        memset(&r, 0, sizeof(r));
        r.rt_dev = config->tundevice;
        r.rt_dst.sa_family = AF_INET;
-       *(u32 *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
+       *(uint32_t *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
        r.rt_gateway.sa_family = AF_INET;
-       *(u32 *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
+       *(uint32_t *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
        r.rt_genmask.sa_family = AF_INET;
-       *(u32 *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
+       *(uint32_t *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
        r.rt_flags = (RTF_UP | RTF_STATIC);
        if (gw)
                r.rt_flags |= RTF_GATEWAY;
        else if (mask == 0xffffffff)
                r.rt_flags |= RTF_HOST;
 
-       LOG(1, ip, 0, 0, "Route %s %u.%u.%u.%u/%u.%u.%u.%u %u.%u.%u.%u\n",
-           add ? "add" : "del",
-           ip   >> 24, ip   >> 16 & 0xff, ip   >> 8 & 0xff, ip   & 0xff,
-           mask >> 24, mask >> 16 & 0xff, mask >> 8 & 0xff, mask & 0xff,
-           gw   >> 24, gw   >> 16 & 0xff, gw   >> 8 & 0xff, gw   & 0xff);
+       LOG(1, s, 0, "Route %s %s/%s%s%s\n", add ? "add" : "del",
+           fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1),
+           gw ? " via" : "", gw ? fmtaddr(htonl(gw), 2) : "");
 
        if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
-               LOG(0, 0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
+               LOG(0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
 
 #ifdef BGP
        if (add)
@@ -355,11 +427,61 @@ static void routeset(sessionidt s, ipt ip, ipt mask, ipt gw, u8 add)
        }
 }
 
+void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add)
+{
+       struct in6_rtmsg rt;
+       char ipv6addr[INET6_ADDRSTRLEN];
+
+       if (ifr6fd < 0)
+       {
+               LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n");
+               return;
+       }
+
+       memset(&rt, 0, sizeof(rt));
+
+       memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr));
+       rt.rtmsg_dst_len = prefixlen;
+       rt.rtmsg_metric = 1;
+       rt.rtmsg_flags = RTF_UP;
+       rt.rtmsg_ifindex = tunidx;
+
+       LOG(1, 0, 0, "Route %s %s/%d\n",
+           add ? "add" : "del",
+           inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN),
+           prefixlen);
+
+       if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0)
+               LOG(0, 0, 0, "route6set() error in ioctl: %s\n",
+                               strerror(errno));
+
+       // FIXME: need to add BGP routing (RFC2858)
+
+       if (s)
+       {
+               if (!add)       // Are we deleting a route?
+                       s = 0;  // Caching the session as '0' is the same as uncaching.
+
+               cache_ipv6map(ip, prefixlen, s);
+       }
+       
+       return;
+}
+
+// defined in linux/ipv6.h, but tricky to include from user-space
+// TODO: move routing to use netlink rather than ioctl
+struct in6_ifreq {
+       struct in6_addr ifr6_addr;
+       __u32 ifr6_prefixlen;
+       unsigned int ifr6_ifindex;
+};
+
 //
 // Set up TUN interface
 static void inittun(void)
 {
        struct ifreq ifr;
+       struct in6_ifreq ifr6;
        struct sockaddr_in sin = {0};
        memset(&ifr, 0, sizeof(ifr));
        ifr.ifr_flags = IFF_TUN;
@@ -367,7 +489,7 @@ static void inittun(void)
        tunfd = open(TUNDEVICE, O_RDWR);
        if (tunfd < 0)
        {                          // fatal
-               LOG(0, 0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
+               LOG(0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
                exit(1);
        }
        {
@@ -376,7 +498,7 @@ static void inittun(void)
        }
        if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
                exit(1);
        }
        assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
@@ -389,22 +511,58 @@ static void inittun(void)
 
        if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
                exit(1);
        }
        /* Bump up the qlen to deal with bursts from the network */
        ifr.ifr_qlen = 1000;
        if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
                exit(1);
        }
        ifr.ifr_flags = IFF_UP;
        if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
                exit(1);
        }
+       if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
+       {
+               LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
+               exit(1);
+       }
+       tunidx = ifr.ifr_ifindex;
+
+       // Only setup IPv6 on the tun device if we have a configured prefix
+       if (config->ipv6_prefix.s6_addr[0] > 0) {
+               ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
+
+               // Link local address is FE80::1
+               memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
+               ifr6.ifr6_addr.s6_addr[0] = 0xFE;
+               ifr6.ifr6_addr.s6_addr[1] = 0x80;
+               ifr6.ifr6_addr.s6_addr[15] = 1;
+               ifr6.ifr6_prefixlen = 64;
+               ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+               if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
+               {
+                       LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
+                               " %s\n", strerror(errno));
+               }
+
+               // Global address is prefix::1
+               memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
+               ifr6.ifr6_addr = config->ipv6_prefix;
+               ifr6.ifr6_addr.s6_addr[15] = 1;
+               ifr6.ifr6_prefixlen = 64;
+               ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+               if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
+               {
+                       LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
+                               strerror(errno));
+               }
+       }
 }
 
 // set up UDP port
@@ -426,7 +584,7 @@ static void initudp(void)
        }
        if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
        {
-               LOG(0, 0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
                exit(1);
        }
        snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
@@ -434,12 +592,12 @@ static void initudp(void)
        // Control
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
-       addr.sin_port = htons(1702);
-       controlfd = socket(AF_INET, SOCK_DGRAM, 17);
+       addr.sin_port = htons(NSCTL_PORT);
+       controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
        if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
        {
-               LOG(0, 0, 0, 0, "Error in control bind: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
                exit(1);
        }
 }
@@ -459,27 +617,71 @@ static void initudp(void)
 // IP address.
 //
 
-static int lookup_ipmap(ipt ip)
+static int lookup_ipmap(in_addr_t ip)
+{
+       uint8_t *a = (uint8_t *) &ip;
+       uint8_t **d = (uint8_t **) ip_hash;
+
+       if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
+       if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
+       if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
+
+       return (int) (intptr_t) d[(size_t) *a];
+}
+
+static int lookup_ipv6map(struct in6_addr ip)
 {
-       u8 *a = (u8 *)&ip;
-       char **d = (char **) ip_hash;
+       struct ipv6radix *curnode;
+       int i;
        int s;
+       char ipv6addr[INET6_ADDRSTRLEN];
+
+       curnode = &ipv6_hash[ip.s6_addr[0]];
+       i = 1;
+       s = curnode->sess;
+
+       while (s == 0 && i < 15 && curnode->branch != NULL)
+       {
+               curnode = &curnode->branch[ip.s6_addr[i]];
+               s = curnode->sess;
+               i++;
+       }
 
-       if (!(d = (char **) d[(size_t) *a++])) return 0;
-       if (!(d = (char **) d[(size_t) *a++])) return 0;
-       if (!(d = (char **) d[(size_t) *a++])) return 0;
+       LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
+                       inet_ntop(AF_INET6, &ip, ipv6addr,
+                               INET6_ADDRSTRLEN),
+                       s);
 
-       s = (ipt) d[(size_t) *a];
        return s;
 }
 
-sessionidt sessionbyip(ipt ip)
+sessionidt sessionbyip(in_addr_t ip)
 {
        int s = lookup_ipmap(ip);
-       CSTAT(call_sessionbyip);
+       CSTAT(sessionbyip);
+
+       if (s > 0 && s < MAXSESSION && session[s].opened)
+               return (sessionidt) s;
+
+       return 0;
+}
+
+sessionidt sessionbyipv6(struct in6_addr ip)
+{
+       int s;
+       CSTAT(sessionbyipv6);
 
-       if (s > 0 && s < MAXSESSION && session[s].tunnel)
+       if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
+               (ip.s6_addr[0] == 0xFE && ip.s6_addr[1] == 0x80 &&
+                (ip.s6_addr16[1] == ip.s6_addr16[2] == ip.s6_addr16[3] == 0))) {
+               s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
+       } else {
+               s = lookup_ipv6map(ip);
+       }
+
+       if (s > 0 && s < MAXSESSION && session[s].opened)
                return s;
+
        return 0;
 }
 
@@ -489,38 +691,75 @@ sessionidt sessionbyip(ipt ip)
 //
 // (It's actually cached in network order)
 //
-static void cache_ipmap(ipt ip, int s)
+static void cache_ipmap(in_addr_t ip, int s)
 {
-       ipt nip = htonl(ip);            // MUST be in network order. I.e. MSB must in be ((char*)(&ip))[0]
-       u8 *a = (u8 *) &nip;
-       char **d = (char **) ip_hash;
+       in_addr_t nip = htonl(ip);      // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
+       uint8_t *a = (uint8_t *) &nip;
+       uint8_t **d = (uint8_t **) ip_hash;
        int i;
 
        for (i = 0; i < 3; i++)
        {
                if (!d[(size_t) a[i]])
                {
-                       if (!(d[(size_t) a[i]] = calloc(256, sizeof (void *))))
+                       if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
                                return;
                }
 
-               d = (char **) d[(size_t) a[i]];
+               d = (uint8_t **) d[(size_t) a[i]];
        }
 
-       d[(size_t) a[3]] = (char *)((int)s);
+       d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
 
        if (s > 0)
-               LOG(4, ip, s, session[s].tunnel, "Caching ip address %s\n", inet_toa(nip));
+               LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
+
        else if (s == 0)
-               LOG(4, ip, 0, 0, "Un-caching ip address %s\n", inet_toa(nip));
+               LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
        // else a map to an ip pool index.
 }
 
-static void uncache_ipmap(ipt ip)
+static void uncache_ipmap(in_addr_t ip)
 {
        cache_ipmap(ip, 0);     // Assign it to the NULL session.
 }
 
+static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
+{
+       int i;
+       int bytes;
+       struct ipv6radix *curnode;
+       char ipv6addr[INET6_ADDRSTRLEN];
+
+       curnode = &ipv6_hash[ip.s6_addr[0]];
+
+       bytes = prefixlen >> 3;
+       i = 1;
+       while (i < bytes) {
+               if (curnode->branch == NULL)
+               {
+                       if (!(curnode->branch = calloc(256,
+                                       sizeof (struct ipv6radix))))
+                               return;
+               }
+               curnode = &curnode->branch[ip.s6_addr[i]];
+               i++;
+       }
+
+       curnode->sess = s;
+
+       if (s > 0)
+               LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
+                               inet_ntop(AF_INET6, &ip, ipv6addr, 
+                                       INET6_ADDRSTRLEN),
+                               prefixlen);
+       else if (s == 0)
+               LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
+                               inet_ntop(AF_INET6, &ip, ipv6addr, 
+                                       INET6_ADDRSTRLEN),
+                               prefixlen);
+}
+
 //
 // CLI list to dump current ipcache.
 //
@@ -539,22 +778,22 @@ int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
        {
                if (!d[i])
                        continue;
-               e = (char**) d[i];
+               e = (char **) d[i];
                for (j = 0; j < 256; ++j)
                {
                        if (!e[j])
                                continue;
-                       f = (char**) e[j];
+                       f = (char **) e[j];
                        for (k = 0; k < 256; ++k)
                        {
                                if (!f[k])
                                        continue;
-                               g = (char**)f[k];
+                               g = (char **)f[k];
                                for (l = 0; l < 256; ++l)
                                {
                                        if (!g[l])
                                                continue;
-                                       cli_print(cli, "%7d %d.%d.%d.%d", (int) g[l], i, j, k, l);
+                                       cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
                                        ++count;
                                }
                        }
@@ -574,10 +813,13 @@ int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
 sessionidt sessionbyuser(char *username)
 {
        int s;
-       CSTAT(call_sessionbyuser);
+       CSTAT(sessionbyuser);
 
-       for (s = 1; s < MAXSESSION ; ++s)
+       for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
        {
+               if (!session[s].opened)
+                       continue;
+
                if (session[s].walled_garden)
                        continue;               // Skip walled garden users.
 
@@ -588,30 +830,30 @@ sessionidt sessionbyuser(char *username)
        return 0;       // Not found.
 }
 
-void send_garp(ipt ip)
+void send_garp(in_addr_t ip)
 {
        int s;
        struct ifreq ifr;
-       u8 mac[6];
+       uint8_t mac[6];
 
        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (s < 0)
        {
-               LOG(0, 0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
                return;
        }
        memset(&ifr, 0, sizeof(ifr));
        strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
        if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
                close(s);
                return;
        }
        memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
        if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
        {
-               LOG(0, 0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
                close(s);
                return;
        }
@@ -619,31 +861,30 @@ void send_garp(ipt ip)
        sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
-// Find session by username, 0 for not found
 static sessiont *sessiontbysessionidt(sessionidt s)
 {
-       if (!s || s > MAXSESSION) return NULL;
+       if (!s || s >= MAXSESSION) return NULL;
        return &session[s];
 }
 
 static sessionidt sessionidtbysessiont(sessiont *s)
 {
        sessionidt val = s-session;
-       if (s < session || val > MAXSESSION) return 0;
+       if (s < session || val >= MAXSESSION) return 0;
        return val;
 }
 
 // actually send a control message for a specific tunnel
-void tunnelsend(u8 * buf, u16 l, tunnelidt t)
+void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
 {
        struct sockaddr_in addr;
 
-       CSTAT(call_tunnelsend);
+       CSTAT(tunnelsend);
 
        if (!t)
        {
                static int backtrace_count = 0;
-               LOG(0, 0, 0, t, "tunnelsend called with 0 as tunnel id\n");
+               LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
                STAT(tunnel_tx_errors);
                log_backtrace(backtrace_count, 5)
                return;
@@ -652,18 +893,19 @@ void tunnelsend(u8 * buf, u16 l, tunnelidt t)
        if (!tunnel[t].ip)
        {
                static int backtrace_count = 0;
-               LOG(1, 0, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
+               LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
                log_backtrace(backtrace_count, 5)
                STAT(tunnel_tx_errors);
                return;
        }
+
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
-       *(u32 *) & addr.sin_addr = htonl(tunnel[t].ip);
+       *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
        addr.sin_port = htons(tunnel[t].port);
 
        // sequence expected, if sequence in message
-       if (*buf & 0x08) *(u16 *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
+       if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
 
        // If this is a control message, deal with retries
        if (*buf & 0x80)
@@ -673,13 +915,13 @@ void tunnelsend(u8 * buf, u16 l, tunnelidt t)
                if (tunnel[t].try > 1)
                {
                        STAT(tunnel_retries);
-                       LOG(3, tunnel[t].ip, 0, t, "Control message resend try %d\n", tunnel[t].try);
+                       LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
                }
        }
 
        if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
        {
-               LOG(0, tunnel[t].ip, ntohs((*(u16 *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
+               LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
                                strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
                STAT(tunnel_tx_errors);
                return;
@@ -694,37 +936,37 @@ void tunnelsend(u8 * buf, u16 l, tunnelidt t)
 // Tiny helper function to write data to
 // the 'tun' device.
 //
-int tun_write(u8 * data, int size)
+int tun_write(uint8_t * data, int size)
 {
        return write(tunfd, data, size);
 }
 
 // process outgoing (to tunnel) IP
 //
-static void processipout(u8 * buf, int len)
+static void processipout(uint8_t * buf, int len)
 {
        sessionidt s;
        sessiont *sp;
        tunnelidt t;
-       ipt ip;
+       in_addr_t ip;
 
-       char * data = buf;      // Keep a copy of the originals.
+       char *data = buf;       // Keep a copy of the originals.
        int size = len;
 
-       u8 b[MAXETHER + 20];
+       uint8_t b[MAXETHER + 20];
 
-       CSTAT(call_processipout);
+       CSTAT(processipout);
 
        if (len < MIN_IP_SIZE)
        {
-               LOG(1, 0, 0, 0, "Short IP, %d bytes\n", len);
-               STAT(tunnel_tx_errors);
+               LOG(1, 0, 0, "Short IP, %d bytes\n", len);
+               STAT(tun_rx_errors);
                return;
        }
        if (len >= MAXETHER)
        {
-               LOG(1, 0, 0, 0, "Oversize IP packet %d bytes\n", len);
-               STAT(tunnel_tx_errors);
+               LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
+               STAT(tun_rx_errors);
                return;
        }
 
@@ -733,13 +975,13 @@ static void processipout(u8 * buf, int len)
        len -= 4;
 
        // Got an IP header now
-       if (*(u8 *)(buf) >> 4 != 4)
+       if (*(uint8_t *)(buf) >> 4 != 4)
        {
-               LOG(1, 0, 0, 0, "IP: Don't understand anything except IPv4\n");
+               LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
                return;
        }
 
-       ip = *(u32 *)(buf + 16);
+       ip = *(uint32_t *)(buf + 16);
        if (!(s = sessionbyip(ip)))
        {
                // Is this a packet for a session that doesn't exist?
@@ -754,14 +996,57 @@ static void processipout(u8 * buf, int len)
 
                if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
                {
-                       LOG(4, 0, 0, 0, "IP: Sending ICMP host unreachable to %s\n", inet_toa(*(u32 *)(buf + 12)));
-                       host_unreachable(*(u32 *)(buf + 12), *(u16 *)(buf + 4), ip, buf, (len < 64) ? 64 : len);
+                       LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
+                       host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4), ip, buf, (len < 64) ? 64 : len);
                }
                return;
        }
        t = session[s].tunnel;
        sp = &session[s];
 
+       // DoS prevention: enforce a maximum number of packets per 0.1s for a session
+       if (config->max_packets > 0)
+       {
+               if (sess_local[s].last_packet_out == TIME)
+               {
+                       int max = config->max_packets;
+
+                       // All packets for throttled sessions are handled by the
+                       // master, so further limit by using the throttle rate.
+                       // A bit of a kludge, since throttle rate is in kbps,
+                       // but should still be generous given our average DSL
+                       // packet size is 200 bytes: a limit of 28kbps equates
+                       // to around 180 packets per second.
+                       if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
+                               max = sp->throttle_out;
+
+                       if (++sess_local[s].packets_out > max)
+                       {
+                               sess_local[s].packets_dropped++;
+                               return;
+                       }
+               }
+               else
+               {
+                       if (sess_local[s].packets_dropped)
+                       {
+                               INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
+                               LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
+                                       sess_local[s].packets_dropped, sess_local[s].packets_out,
+                                       fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
+                                       sp->user);
+                       }
+
+                       sess_local[s].last_packet_out = TIME;
+                       sess_local[s].packets_out = 1;
+                       sess_local[s].packets_dropped = 0;
+               }
+       }
+
+       // run access-list if any
+       if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
+               return;
+
        if (sp->tbf_out)
        {
                // Are we throttling this session?
@@ -778,16 +1063,121 @@ static void processipout(u8 * buf, int len)
                return;
        }
 
-       LOG(5, session[s].ip, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
+       LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
 
        // Add on L2TP header
        {
-               u8 *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
-               if (!p)
+               uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
+               if (!p) return;
+               tunnelsend(b, len + (p-b), t); // send it...
+       }
+
+       // Snooping this session, send it to intercept box
+       if (sp->snoop_ip && sp->snoop_port)
+               snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
+
+       sp->cout += len; // byte count
+       sp->total_cout += len; // byte count
+       sp->pout++;
+       udp_tx += len;
+       sess_local[s].cout += len;      // To send to master..
+}
+
+// process outgoing (to tunnel) IPv6
+//
+static void processipv6out(uint8_t * buf, int len)
+{
+       sessionidt s;
+       sessiont *sp;
+       tunnelidt t;
+       in_addr_t ip;
+       struct in6_addr ip6;
+
+       char *data = buf;       // Keep a copy of the originals.
+       int size = len;
+
+       uint8_t b[MAXETHER + 20];
+
+       CSTAT(processipv6out);
+
+       if (len < MIN_IP_SIZE)
+       {
+               LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
+               STAT(tunnel_tx_errors);
+               return;
+       }
+       if (len >= MAXETHER)
+       {
+               LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
+               STAT(tunnel_tx_errors);
+               return;
+       }
+
+       // Skip the tun header
+       buf += 4;
+       len -= 4;
+
+       // Got an IP header now
+       if (*(uint8_t *)(buf) >> 4 != 6)
+       {
+               LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
+               return;
+       }
+
+       ip6 = *(struct in6_addr *)(buf+24);
+       s = sessionbyipv6(ip6);
+
+       if (s == 0)
+       {
+               ip = *(uint32_t *)(buf + 32);
+               s = sessionbyip(ip);
+       }
+       
+       if (s == 0)
+       {
+               // Is this a packet for a session that doesn't exist?
+               static int rate = 0;    // Number of ICMP packets we've sent this second.
+               static int last = 0;    // Last time we reset the ICMP packet counter 'rate'.
+
+               if (last != time_now)
                {
-                       LOG(3, session[s].ip, s, t, "failed to send packet in processipout.\n");
-                       return;
+                       last = time_now;
+                       rate = 0;
+               }
+
+               if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
+               {
+                       // FIXME: Should send icmp6 host unreachable
                }
+               return;
+       }
+       t = session[s].tunnel;
+       sp = &session[s];
+
+       // FIXME: add DoS prevention/filters?
+
+       if (sp->tbf_out)
+       {
+               // Are we throttling this session?
+               if (config->cluster_iam_master)
+                       tbf_queue_packet(sp->tbf_out, data, size);
+               else
+                       master_throttle_packet(sp->tbf_out, data, size);
+               return;
+       }
+       else if (sp->walled_garden && !config->cluster_iam_master)
+       {
+               // We are walled-gardening this
+               master_garden_packet(s, data, size);
+               return;
+       }
+
+       LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
+
+       // Add on L2TP header
+       {
+               uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6);
+               if (!p) return;
                tunnelsend(b, len + (p-b), t); // send it...
        }
 
@@ -799,24 +1189,24 @@ static void processipout(u8 * buf, int len)
        sp->total_cout += len; // byte count
        sp->pout++;
        udp_tx += len;
-       sess_count[s].cout += len;      // To send to master..
+       sess_local[s].cout += len;      // To send to master..
 }
 
 //
 // Helper routine for the TBF filters.
 // Used to send queued data in to the user!
 //
-static void send_ipout(sessionidt s, u8 *buf, int len)
+static void send_ipout(sessionidt s, uint8_t *buf, int len)
 {
        sessiont *sp;
        tunnelidt t;
-       ipt ip;
+       in_addr_t ip;
 
-       u8 b[MAXETHER + 20];
+       uint8_t b[MAXETHER + 20];
 
        if (len < 0 || len > MAXETHER)
        {
-               LOG(1,0,0,0, "Odd size IP packet: %d bytes\n", len);
+               LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
                return;
        }
 
@@ -824,7 +1214,7 @@ static void send_ipout(sessionidt s, u8 *buf, int len)
        buf += 4;
        len -= 4;
 
-       ip = *(u32 *)(buf + 16);
+       ip = *(in_addr_t *)(buf + 16);
 
        if (!session[s].ip)
                return;
@@ -832,16 +1222,12 @@ static void send_ipout(sessionidt s, u8 *buf, int len)
        t = session[s].tunnel;
        sp = &session[s];
 
-       LOG(5, session[s].ip, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
+       LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
 
        // Add on L2TP header
        {
-               u8 *p = makeppp(b, sizeof(b),  buf, len, t, s, PPPIP);
-               if (!p)
-               {
-                       LOG(3, session[s].ip, s, t, "failed to send packet in send_ipout.\n");
-                       return;
-               }
+               uint8_t *p = makeppp(b, sizeof(b),  buf, len, t, s, PPPIP);
+               if (!p) return;
                tunnelsend(b, len + (p-b), t); // send it...
        }
 
@@ -853,55 +1239,55 @@ static void send_ipout(sessionidt s, u8 *buf, int len)
        sp->total_cout += len; // byte count
        sp->pout++;
        udp_tx += len;
-       sess_count[s].cout += len;      // To send to master..
+       sess_local[s].cout += len;      // To send to master..
 }
 
 // add an AVP (16 bit)
-static void control16(controlt * c, u16 avp, u16 val, u8 m)
+static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
 {
-       u16 l = (m ? 0x8008 : 0x0008);
-       *(u16 *) (c->buf + c->length + 0) = htons(l);
-       *(u16 *) (c->buf + c->length + 2) = htons(0);
-       *(u16 *) (c->buf + c->length + 4) = htons(avp);
-       *(u16 *) (c->buf + c->length + 6) = htons(val);
+       uint16_t l = (m ? 0x8008 : 0x0008);
+       *(uint16_t *) (c->buf + c->length + 0) = htons(l);
+       *(uint16_t *) (c->buf + c->length + 2) = htons(0);
+       *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
+       *(uint16_t *) (c->buf + c->length + 6) = htons(val);
        c->length += 8;
 }
 
 // add an AVP (32 bit)
-static void control32(controlt * c, u16 avp, u32 val, u8 m)
+static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
 {
-       u16 l = (m ? 0x800A : 0x000A);
-       *(u16 *) (c->buf + c->length + 0) = htons(l);
-       *(u16 *) (c->buf + c->length + 2) = htons(0);
-       *(u16 *) (c->buf + c->length + 4) = htons(avp);
-       *(u32 *) (c->buf + c->length + 6) = htonl(val);
+       uint16_t l = (m ? 0x800A : 0x000A);
+       *(uint16_t *) (c->buf + c->length + 0) = htons(l);
+       *(uint16_t *) (c->buf + c->length + 2) = htons(0);
+       *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
+       *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
        c->length += 10;
 }
 
-// add an AVP (32 bit)
-static void controls(controlt * c, u16 avp, char *val, u8 m)
+// add an AVP (string)
+static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
 {
-       u16 l = ((m ? 0x8000 : 0) + strlen(val) + 6);
-       *(u16 *) (c->buf + c->length + 0) = htons(l);
-       *(u16 *) (c->buf + c->length + 2) = htons(0);
-       *(u16 *) (c->buf + c->length + 4) = htons(avp);
+       uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
+       *(uint16_t *) (c->buf + c->length + 0) = htons(l);
+       *(uint16_t *) (c->buf + c->length + 2) = htons(0);
+       *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
        memcpy(c->buf + c->length + 6, val, strlen(val));
        c->length += 6 + strlen(val);
 }
 
 // add a binary AVP
-static void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m)
+static void controlb(controlt * c, uint16_t avp, char *val, unsigned int len, uint8_t m)
 {
-       u16 l = ((m ? 0x8000 : 0) + len + 6);
-       *(u16 *) (c->buf + c->length + 0) = htons(l);
-       *(u16 *) (c->buf + c->length + 2) = htons(0);
-       *(u16 *) (c->buf + c->length + 4) = htons(avp);
+       uint16_t l = ((m ? 0x8000 : 0) + len + 6);
+       *(uint16_t *) (c->buf + c->length + 0) = htons(l);
+       *(uint16_t *) (c->buf + c->length + 2) = htons(0);
+       *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
        memcpy(c->buf + c->length + 6, val, len);
        c->length += 6 + len;
 }
 
 // new control connection
-static controlt *controlnew(u16 mtype)
+static controlt *controlnew(uint16_t mtype)
 {
        controlt *c;
        if (!controlfree)
@@ -913,7 +1299,7 @@ static controlt *controlnew(u16 mtype)
        }
        assert(c);
        c->next = 0;
-       *(u16 *) (c->buf + 0) = htons(0xC802); // flags/ver
+       *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
        c->length = 12;
        control16(c, 0, mtype, 1);
        return c;
@@ -923,34 +1309,36 @@ static controlt *controlnew(u16 mtype)
 // (ZLB send).
 static void controlnull(tunnelidt t)
 {
-       u8 buf[12];
+       uint8_t buf[12];
        if (tunnel[t].controlc) // Messages queued; They will carry the ack.
                return;
 
-       *(u16 *) (buf + 0) = htons(0xC802); // flags/ver
-       *(u16 *) (buf + 2) = htons(12); // length
-       *(u16 *) (buf + 4) = htons(tunnel[t].far); // tunnel
-       *(u16 *) (buf + 6) = htons(0); // session
-       *(u16 *) (buf + 8) = htons(tunnel[t].ns); // sequence
-       *(u16 *) (buf + 10) = htons(tunnel[t].nr); // sequence
+       *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
+       *(uint16_t *) (buf + 2) = htons(12); // length
+       *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
+       *(uint16_t *) (buf + 6) = htons(0); // session
+       *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
+       *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
        tunnelsend(buf, 12, t);
 }
 
 // add a control message to a tunnel, and send if within window
-static void controladd(controlt * c, tunnelidt t, sessionidt s)
+static void controladd(controlt * c, tunnelidt t, sessionidt far)
 {
-       *(u16 *) (c->buf + 2) = htons(c->length); // length
-       *(u16 *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
-       *(u16 *) (c->buf + 6) = htons(s ? session[s].far : 0); // session
-       *(u16 *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
+       *(uint16_t *) (c->buf + 2) = htons(c->length); // length
+       *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
+       *(uint16_t *) (c->buf + 6) = htons(far); // session
+       *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
        tunnel[t].ns++;              // advance sequence
        // link in message in to queue
        if (tunnel[t].controlc)
                tunnel[t].controle->next = c;
        else
                tunnel[t].controls = c;
+
        tunnel[t].controle = c;
        tunnel[t].controlc++;
+
        // send now if space in window
        if (tunnel[t].controlc <= tunnel[t].window)
        {
@@ -971,7 +1359,7 @@ static void controladd(controlt * c, tunnelidt t, sessionidt s)
 //
 void throttle_session(sessionidt s, int rate_in, int rate_out)
 {
-       if (!session[s].tunnel)
+       if (!session[s].opened)
                return; // No-one home.
 
        if (!*session[s].user)
@@ -1006,94 +1394,160 @@ void throttle_session(sessionidt s, int rate_in, int rate_out)
        }
 }
 
+// add/remove filters from session (-1 = no change)
+static void filter_session(sessionidt s, int filter_in, int filter_out)
+{
+       if (!session[s].opened)
+               return; // No-one home.
+
+       if (!*session[s].user)
+               return; // User not logged in
+
+       // paranoia
+       if (filter_in > MAXFILTER) filter_in = -1;
+       if (filter_out > MAXFILTER) filter_out = -1;
+       if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
+       if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
+
+       if (filter_in >= 0)
+       {
+               if (session[s].filter_in)
+                       ip_filters[session[s].filter_in - 1].used--;
+
+               if (filter_in > 0)
+                       ip_filters[filter_in - 1].used++;
+
+               session[s].filter_in = filter_in;
+       }
+
+       if (filter_out >= 0)
+       {
+               if (session[s].filter_out)
+                       ip_filters[session[s].filter_out - 1].used--;
+
+               if (filter_out > 0)
+                       ip_filters[filter_out - 1].used++;
+
+               session[s].filter_out = filter_out;
+       }
+}
+
 // start tidy shutdown of session
-void sessionshutdown(sessionidt s, char *reason)
+void sessionshutdown(sessionidt s, char *reason, int result, int error)
 {
        int walled_garden = session[s].walled_garden;
 
 
-       CSTAT(call_sessionshutdown);
+       CSTAT(sessionshutdown);
 
-       if (!session[s].tunnel)
+       if (!session[s].opened)
        {
-               LOG(3, session[s].ip, s, session[s].tunnel, "Called sessionshutdown on a session with no tunnel.\n");
+               LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
                return;                   // not a live session
        }
 
        if (!session[s].die)
        {
                struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
-               LOG(2, 0, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
+               LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
                run_plugins(PLUGIN_KILL_SESSION, &data);
        }
 
-       // RADIUS Stop message
-       if (session[s].opened && !walled_garden && !session[s].die)
+       if (session[s].ip && !walled_garden && !session[s].die)
        {
-               u16 r = session[s].radius;
+               // RADIUS Stop message
+               uint16_t r = sess_local[s].radius;
                if (!r)
+                       r = radiusnew(s);
+
+               if (r)
                {
-                       if (!(r = radiusnew(s)))
-                       {
-                               LOG(1, 0, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
-                               STAT(radius_overflow);
-                       }
-                       else
-                       {
-                               int n;
-                               for (n = 0; n < 15; n++)
-                                       radius[r].auth[n] = rand();
-                       }
+                       // stop, if not already trying
+                       if (radius[r].state != RADIUSSTOP)
+                               radiussend(r, RADIUSSTOP);
                }
-               if (r && radius[r].state != RADIUSSTOP)
-                       radiussend(r, RADIUSSTOP); // stop, if not already trying
+               else
+                       LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
+
+               // Save counters to dump to accounting file
+               if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
+                       memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
        }
 
        if (session[s].ip)
        {                          // IP allocated, clear and unroute
                int r;
+               int routed = 0;
                for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
                {
+                       if ((session[s].ip & session[s].route[r].mask) ==
+                           (session[s].route[r].ip & session[s].route[r].mask))
+                               routed++;
+
                        routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
                        session[s].route[r].ip = 0;
                }
 
                if (session[s].ip_pool_index == -1) // static ip
                {
-                       routeset(s, session[s].ip, 0, 0, 0);    // Delete route.
+                       if (!routed) routeset(s, session[s].ip, 0, 0, 0);
                        session[s].ip = 0;
                }
                else
                        free_ip_address(s);
+
+               // unroute IPv6, if setup
+               if (session[s].flags & SF_IPV6_ROUTED)
+                       route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
        }
 
        if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
                throttle_session(s, 0, 0);
 
+       if (result)
        {                            // Send CDN
                controlt *c = controlnew(14); // sending CDN
-               control16(c, 1, 3, 1);    // result code (admin reasons - TBA make error, general error, add message
+               if (error)
+               {
+                       char buf[4];
+                       *(uint16_t *) buf     = htons(result);
+                       *(uint16_t *) (buf+2) = htons(error);
+                       controlb(c, 1, buf, 4, 1);
+               }
+               else
+                       control16(c, 1, result, 1);
+
                control16(c, 14, s, 1);   // assigned session (our end)
-               controladd(c, session[s].tunnel, s); // send the message
+               controladd(c, session[s].tunnel, session[s].far); // send the message
        }
 
        if (!session[s].die)
-               session[s].die = now() + 150; // Clean up in 15 seconds
+               session[s].die = TIME + 150; // Clean up in 15 seconds
+
+       // update filter refcounts
+       if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
+       if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
 
        cluster_send_session(s);
 }
 
 void sendipcp(tunnelidt t, sessionidt s)
 {
-       u8 buf[MAXCONTROL];
-       u16 r = session[s].radius;
-       u8 *q;
+       uint8_t buf[MAXCONTROL];
+       uint16_t r = sess_local[s].radius;
+       uint8_t *q;
 
-       CSTAT(call_sendipcp);
+       CSTAT(sendipcp);
 
        if (!r)
                r = radiusnew(s);
 
+       if (!r)
+       {
+               sessionshutdown(s, "No free RADIUS sessions for IPCP", 3, 0);
+               return;
+       }
+
        if (radius[r].state != RADIUSIPCP)
        {
                radius[r].state = RADIUSIPCP;
@@ -1104,48 +1558,83 @@ void sendipcp(tunnelidt t, sessionidt s)
        if (radius[r].try > 10)
        {
                radiusclear(r, s);      // Clear radius session.
-               sessionshutdown(s, "No reply on IPCP");
+               sessionshutdown(s, "No reply to IPCP.", 3, 0);
                return;
        }
 
        q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
-       if (!q)
-       {
-               LOG(3, session[s].ip, s, t, "failed to send packet in sendipcp.\n");
-               return;
-       }
+       if (!q) return;
 
        *q = ConfigReq;
-       q[1] = r << RADIUS_SHIFT;                    // ID, dont care, we only send one type of request
-       *(u16 *) (q + 2) = htons(10);
+       q[1] = r >> RADIUS_SHIFT;                    // ID, dont care, we only send one type of request
+       *(uint16_t *) (q + 2) = htons(10);
        q[4] = 3;
        q[5] = 6;
-       *(u32 *) (q + 6) = config->peer_address ? config->peer_address :
-                          config->bind_address ? config->bind_address :
-                          my_address; // send my IP
+       *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
+                                config->bind_address ? config->bind_address :
+                                my_address; // send my IP
 
        tunnelsend(buf, 10 + (q - buf), t); // send it
        session[s].flags &= ~SF_IPCP_ACKED;     // Clear flag.
+
+       // If we have an IPv6 prefix length configured, assume we should
+       // try to negotiate an IPv6 session as well. Unless we've had a
+       // (N)ACK for IPV6CP.
+       if (config->ipv6_prefix.s6_addr[0] > 0 && 
+                       !(session[s].flags & SF_IPV6CP_ACKED) &&
+                       !(session[s].flags & SF_IPV6_NACKED))
+       {
+               q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
+               if (!q) return;
+
+               *q = ConfigReq;
+               q[1] = r >> RADIUS_SHIFT;               // ID, don't care, we
+                                                       // only send one type
+                                                       // of request
+               *(uint16_t *) (q + 2) = htons(14);
+               q[4] = 1;
+               q[5] = 10;
+               *(uint32_t *) (q + 6) = 0;              // We'll be prefix::1
+               *(uint32_t *) (q + 10) = 0;
+               q[13] = 1;
+
+               tunnelsend(buf, 14 + (q - buf), t);     // send it
+       }
+}
+
+static void sessionclear(sessionidt s)
+{
+       memset(&session[s], 0, sizeof(session[s]));
+       memset(&sess_local[s], 0, sizeof(sess_local[s]));
+       memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
+
+       session[s].tunnel = T_FREE;     // Mark it as free.
+       session[s].next = sessionfree;
+       sessionfree = s;
 }
 
 // kill a session now
-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)
 {
 
-       CSTAT(call_sessionkill);
+       CSTAT(sessionkill);
 
-       session[s].die = now();
-       sessionshutdown(s, reason);  // close radius/routes, etc.
-       if (session[s].radius)
-               radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
+       if (!session[s].opened) // not alive
+               return;
 
-       LOG(2, 0, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
+       if (session[s].next)
+       {
+               LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
+               return;
+       }
 
-       memset(&session[s], 0, sizeof(session[s]));
-       session[s].tunnel = T_FREE;     // Mark it as free.
-       session[s].next = sessionfree;
-       sessionfree = s;
-       cli_session_actions[s].action = 0;
+       session[s].die = TIME;
+       sessionshutdown(s, reason, 3, 0);  // close radius/routes, etc.
+       if (sess_local[s].radius)
+               radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
+
+       LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
+       sessionclear(s);
        cluster_send_session(s);
 }
 
@@ -1162,7 +1651,7 @@ static void tunnelkill(tunnelidt t, char *reason)
        sessionidt s;
        controlt *c;
 
-       CSTAT(call_tunnelkill);
+       CSTAT(tunnelkill);
 
        tunnel[t].state = TUNNELDIE;
 
@@ -1176,23 +1665,23 @@ static void tunnelkill(tunnelidt t, char *reason)
                controlfree = c;
        }
        // kill sessions
-       for (s = 1; s < MAXSESSION; s++)
+       for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                if (session[s].tunnel == t)
                        sessionkill(s, reason);
 
        // free tunnel
        tunnelclear(t);
-       LOG(1, 0, 0, t, "Kill tunnel %d: %s\n", t, reason);
-       cli_tunnel_actions[s].action = 0;
+       LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
+       cli_tunnel_actions[t].action = 0;
        cluster_send_tunnel(t);
 }
 
 // shut down a tunnel cleanly
-static void tunnelshutdown(tunnelidt t, char *reason)
+static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
 {
        sessionidt s;
 
-       CSTAT(call_tunnelshutdown);
+       CSTAT(tunnelshutdown);
 
        if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
        {
@@ -1200,34 +1689,55 @@ static void tunnelshutdown(tunnelidt t, char *reason)
                tunnelkill(t, reason);
                return;
        }
-       LOG(1, 0, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
+       LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
 
        // close session
-       for (s = 1; s < MAXSESSION; s++)
+       for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                if (session[s].tunnel == t)
-                       sessionshutdown(s, reason);
+                       sessionshutdown(s, reason, 3, 0);
 
        tunnel[t].state = TUNNELDIE;
-       tunnel[t].die = now() + 700; // Clean up in 70 seconds
+       tunnel[t].die = TIME + 700; // Clean up in 70 seconds
        cluster_send_tunnel(t);
        // TBA - should we wait for sessions to stop?
-       {                            // Send StopCCN
-               controlt *c = controlnew(4); // sending StopCCN
-               control16(c, 1, 1, 1);    // result code (admin reasons - TBA make error, general error, add message
-               control16(c, 9, t, 1);    // assigned tunnel (our end)
-               controladd(c, t, 0);      // send the message
+       if (result) 
+       {
+               controlt *c = controlnew(4);    // sending StopCCN
+               if (error)
+               {
+                       char buf[64];
+                       int l = 4;
+                       *(uint16_t *) buf     = htons(result);
+                       *(uint16_t *) (buf+2) = htons(error);
+                       if (msg)
+                       {
+                               int m = strlen(msg);
+                               if (m + 4 > sizeof(buf))
+                                   m = sizeof(buf) - 4;
+
+                               memcpy(buf+4, msg, m);
+                               l += m;
+                       }
+
+                       controlb(c, 1, buf, l, 1);
+               }
+               else
+                       control16(c, 1, result, 1);
+
+               control16(c, 9, t, 1);          // assigned tunnel (our end)
+               controladd(c, t, 0);            // send the message
        }
 }
 
 // read and process packet on tunnel (UDP)
-void processudp(u8 * buf, int len, struct sockaddr_in *addr)
+void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 {
        char *chapresponse = NULL;
-       u16 l = len, t = 0, s = 0, ns = 0, nr = 0;
-       u8 *p = buf + 2;
+       uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
+       uint8_t *p = buf + 2;
 
 
-       CSTAT(call_processudp);
+       CSTAT(processudp);
 
        udp_rx += len;
        udp_rx_pkt++;
@@ -1236,69 +1746,68 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
        INC_STAT(tunnel_rx_bytes, len);
        if (len < 6)
        {
-               LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "Short UDP, %d bytes\n", len);
+               LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
                STAT(tunnel_rx_errors);
                return;
        }
        if ((buf[1] & 0x0F) != 2)
        {
-               LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
+               LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
                STAT(tunnel_rx_errors);
                return;
        }
        if (*buf & 0x40)
        {                          // length
-               l = ntohs(*(u16 *) p);
+               l = ntohs(*(uint16_t *) p);
                p += 2;
        }
-       t = ntohs(*(u16 *) p);
+       t = ntohs(*(uint16_t *) p);
        p += 2;
-       s = ntohs(*(u16 *) p);
+       s = ntohs(*(uint16_t *) p);
        p += 2;
        if (s >= MAXSESSION)
        {
-               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Received UDP packet with invalid session ID\n");
+               LOG(1, s, t, "Received UDP packet with invalid session ID\n");
                STAT(tunnel_rx_errors);
                return;
        }
        if (t >= MAXTUNNEL)
        {
-               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Received UDP packet with invalid tunnel ID\n");
+               LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
                STAT(tunnel_rx_errors);
                return;
        }
        if (*buf & 0x08)
        {                          // ns/nr
-               ns = ntohs(*(u16 *) p);
+               ns = ntohs(*(uint16_t *) p);
                p += 2;
-               nr = ntohs(*(u16 *) p);
+               nr = ntohs(*(uint16_t *) p);
                p += 2;
        }
        if (*buf & 0x02)
        {                          // offset
-               u16 o = ntohs(*(u16 *) p);
+               uint16_t o = ntohs(*(uint16_t *) p);
                p += o + 2;
        }
        if ((p - buf) > l)
        {
-               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Bad length %d>%d\n", (p - buf), l);
+               LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
                STAT(tunnel_rx_errors);
                return;
        }
        l -= (p - buf);
        if (*buf & 0x80)
        {                          // control
-               u16 message = 0xFFFF; // message type
-               u8 fatal = 0;
-               u8 mandatorymessage = 0;
-               u8 chap = 0;      // if CHAP being used
-               u16 asession = 0;  // assigned session
-               u32 amagic = 0;    // magic number
-               u8 aflags = 0;    // flags from last LCF
-               u16 version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
-               int requestchap = 0;    // do we request PAP instead of original CHAP request?
-               char called[MAXTEL] = ""; // called number
-               char calling[MAXTEL] = ""; // calling number
+               uint16_t message = 0xFFFF;      // message type
+               uint8_t fatal = 0;
+               uint8_t mandatory = 0;
+               uint8_t authtype = 0;           // proxy auth type
+               uint16_t asession = 0;          // assigned session
+               uint32_t amagic = 0;            // magic number
+               uint8_t aflags = 0;             // flags from last LCF
+               uint16_t version = 0x0100;      // protocol version (we handle 0.0 as well and send that back just in case)
+               char called[MAXTEL] = "";       // called number
+               char calling[MAXTEL] = "";      // calling number
 
                if (!config->cluster_iam_master)
                {
@@ -1306,16 +1815,18 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                        return;
                }
 
-               if ((*buf & 0xCA) != 0xC8)
+               // control messages must have bits 0x80|0x40|0x08
+               // (type, length and sequence) set, and bits 0x02|0x01
+               // (offset and priority) clear
+               if ((*buf & 0xCB) != 0xC8)
                {
-                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Bad control header %02X\n", *buf);
+                       LOG(1, s, t, "Bad control header %02X\n", *buf);
                        STAT(tunnel_rx_errors);
                        return;
                }
-               LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
-                               l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
-               // if no tunnel specified, assign one
-               if (!t)
+
+               // check for duplicate tunnel open message
+               if (!t && ns == 0)
                {
                        int i;
 
@@ -1325,28 +1836,52 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                        for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
                        {
                                if (tunnel[i].state != TUNNELOPENING ||
-                                       tunnel[i].ip != ntohl(*(ipt *) & addr->sin_addr) ||
+                                       tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
                                        tunnel[i].port != ntohs(addr->sin_port) )
                                        continue;
                                t = i;
+                               LOG(3, s, t, "Duplicate SCCRQ?\n");
                                break;
                        }
                }
 
+               LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
+                       l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
+
+               // if no tunnel specified, assign one
                if (!t)
                {
                        if (!(t = new_tunnel()))
                        {
-                               LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "No more tunnels\n");
+                               LOG(1, 0, 0, "No more tunnels\n");
                                STAT(tunnel_overflow);
                                return;
                        }
                        tunnelclear(t);
-                       tunnel[t].ip = ntohl(*(ipt *) & addr->sin_addr);
+                       tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
                        tunnel[t].port = ntohs(addr->sin_port);
                        tunnel[t].window = 4; // default window
-                       LOG(1, ntohl(addr->sin_addr.s_addr), 0, t, "   New tunnel from %u.%u.%u.%u/%u ID %d\n", tunnel[t].ip >> 24, tunnel[t].ip >> 16 & 255, tunnel[t].ip >> 8 & 255, tunnel[t].ip & 255, tunnel[t].port, t);
                        STAT(tunnel_created);
+                       LOG(1, 0, t, "   New tunnel from %s:%u ID %d\n",
+                               fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
+               }
+
+                       // If the 'ns' just received is not the 'nr' we're
+                       // expecting, just send an ack and drop it.
+                       //
+                       // if 'ns' is less, then we got a retransmitted packet.
+                       // if 'ns' is greater than missed a packet. Either way
+                       // we should ignore it.
+               if (ns != tunnel[t].nr)
+               {
+                       // is this the sequence we were expecting?
+                       STAT(tunnel_rx_errors);
+                       LOG(1, 0, t, "   Out of sequence tunnel %d, (%d is not the expected %d)\n",
+                               t, ns, tunnel[t].nr);
+
+                       if (l)  // Is this not a ZLB?
+                               controlnull(t);
+                       return;
                }
 
                // This is used to time out old tunnels
@@ -1356,7 +1891,7 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                {
                        int skip = tunnel[t].window; // track how many in-window packets are still in queue
                                // some to clear maybe?
-                       while (tunnel[t].controlc && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
+                       while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
                        {
                                controlt *c = tunnel[t].controls;
                                tunnel[t].controls = c->next;
@@ -1367,22 +1902,6 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                tunnel[t].try = 0; // we have progress
                        }
 
-                               // If the 'ns' just received is not the 'nr' we're
-                               // expecting, just send an ack and drop it.
-                               //
-                               // if 'ns' is less, then we got a retransmitted packet.
-                               // if 'ns' is greater than missed a packet. Either way
-                               // we should ignore it.
-                       if (ns != tunnel[t].nr)
-                       {
-                               // is this the sequence we were expecting?
-                               LOG(1, ntohl(addr->sin_addr.s_addr), 0, t, "   Out of sequence tunnel %d, (%d is not the expected %d)\n", t, ns, tunnel[t].nr);
-                               STAT(tunnel_rx_errors);
-
-                               if (l)  // Is this not a ZLB?
-                                       controlnull(t);
-                               return;
-                       }
                        // receiver advance (do here so quoted correctly in any sends below)
                        if (l) tunnel[t].nr = (ns + 1);
                        if (skip < 0) skip = 0;
@@ -1409,274 +1928,309 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                }
                if (l)
                {                     // if not a null message
+                       int result = 0;
+                       int error = 0;
+                       char *msg = 0;
+
                        // process AVPs
-                       while (l && !(fatal & 0x80))
+                       while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
                        {
-                               u16 n = (ntohs(*(u16 *) p) & 0x3FF);
-                               u8 *b = p;
-                               u8 flags = *p;
-                               u16 mtype;
-                               p += n;       // next
-                               if (l < n)
+                               uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
+                               uint8_t *b = p;
+                               uint8_t flags = *p;
+                               uint16_t mtype;
+                               if (n > l)
                                {
-                                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Invalid length in AVP\n");
+                                       LOG(1, s, t, "Invalid length in AVP\n");
                                        STAT(tunnel_rx_errors);
-                                       fatal = flags;
                                        return;
                                }
+                               p += n;       // next
                                l -= n;
+                               if (flags & 0x3C) // reserved bits, should be clear
+                               {
+                                       LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
+                                       fatal = flags;
+                                       result = 2; // general error
+                                       error = 3; // reserved field non-zero
+                                       msg = 0;
+                                       continue; // next
+                               }
+                               b += 2;
+                               if (*(uint16_t *) (b))
+                               {
+                                       LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
+                                       fatal = flags;
+                                       result = 2; // general error
+                                       error = 6; // generic vendor-specific error
+                                       msg = "unsupported vendor-specific";
+                                       continue; // next
+                               }
+                               b += 2;
+                               mtype = ntohs(*(uint16_t *) (b));
+                               b += 2;
+                               n -= 6;
+
                                if (flags & 0x40)
                                {
+                                       uint16_t orig_len;
+
                                        // handle hidden AVPs
                                        if (!*config->l2tpsecret)
                                        {
-                                               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP requested, but no L2TP secret.\n");
+                                               LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
                                                fatal = flags;
+                                               result = 2; // general error
+                                               error = 6; // generic vendor-specific error
+                                               msg = "secret not specified";
                                                continue;
                                        }
                                        if (!session[s].random_vector_length)
                                        {
-                                               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP requested, but no random vector.\n");
+                                               LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
                                                fatal = flags;
+                                               result = 2; // general error
+                                               error = 6; // generic
+                                               msg = "no random vector";
                                                continue;
                                        }
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP\n");
+                                       if (n < 8)
+                                       {
+                                               LOG(2, s, t, "Short hidden AVP.\n");
+                                               fatal = flags;
+                                               result = 2; // general error
+                                               error = 2; // length is wrong
+                                               msg = 0;
+                                               continue;
+                                       }
+
+                                       LOG(4, s, t, "Hidden AVP\n");
+
                                        // Unhide the AVP
-                                       n = unhide_avp(b, t, s, n);
-                                       if (n == 0)
+                                       unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
+
+                                       orig_len = ntohs(*(uint16_t *) b);
+                                       if (orig_len > n + 2)
                                        {
+                                               LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
+                                                   orig_len, n);
+
                                                fatal = flags;
+                                               result = 2; // general error
+                                               error = 2; // length is wrong
+                                               msg = 0;
                                                continue;
                                        }
+
+                                       b += 2;
+                                       n = orig_len;
                                }
-                               if (*b & 0x3C)
-                               {
-                                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unrecognised AVP flags %02X\n", *b);
-                                       fatal = flags;
-                                       continue; // next
-                               }
-                               b += 2;
-                               if (*(u16 *) (b))
-                               {
-                                       LOG(2, ntohl(addr->sin_addr.s_addr), s, t, "Unknown AVP vendor %d\n", ntohs(*(u16 *) (b)));
-                                       fatal = flags;
-                                       continue; // next
-                               }
-                               b += 2;
-                               mtype = ntohs(*(u16 *) (b));
-                               b += 2;
-                               n -= 6;
 
-                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   AVP %d (%s) len %d\n", mtype, avpnames[mtype], n);
+                               LOG(4, s, t, "   AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
                                switch (mtype)
                                {
                                case 0:     // message type
-                                       message = ntohs(*(u16 *) b);
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Message type = %d (%s)\n", *b,
-                                                       l2tp_message_types[message]);
-                                       mandatorymessage = flags;
+                                       message = ntohs(*(uint16_t *) b);
+                                       mandatory = flags & 0x80;
+                                       LOG(4, s, t, "   Message type = %d (%s)\n", *b, l2tp_message_type(message));
                                        break;
                                case 1:     // result code
                                        {
-                                               u16 rescode = ntohs(*(u16 *)(b));
+                                               uint16_t rescode = ntohs(*(uint16_t *) b);
                                                const char* resdesc = "(unknown)";
                                                if (message == 4)
                                                { /* StopCCN */
-                                                       if (rescode <= MAX_STOPCCN_RESULT_CODE)
-                                                               resdesc = stopccn_result_codes[rescode];
+                                                       resdesc = stopccn_result_code(rescode);
                                                }
                                                else if (message == 14)
                                                { /* CDN */
-                                                       if (rescode <= MAX_CDN_RESULT_CODE)
-                                                               resdesc = cdn_result_codes[rescode];
+                                                       resdesc = cdn_result_code(rescode);
                                                }
 
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Result Code %d: %s\n",
-                                                       rescode, resdesc);
+                                               LOG(4, s, t, "   Result Code %d: %s\n", rescode, resdesc);
                                                if (n >= 4)
                                                {
-                                                       u16 errcode = ntohs(*(u16 *)(b + 2));
-                                                       const char* errdesc = "(unknown)";
-                                                       if (errcode <= MAX_ERROR_CODE)
-                                                               errdesc = error_codes[errcode];
-                                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Error Code %d: %s\n",
-                                                               errcode, errdesc);
+                                                       uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
+                                                       LOG(4, s, t, "   Error Code %d: %s\n", errcode, error_code(errcode));
                                                }
                                                if (n > 4)
-                                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Error String: %.*s\n",
-                                                               n-4, b+4);
+                                                       LOG(4, s, t, "   Error String: %.*s\n", n-4, b+4);
 
                                                break;
                                        }
                                        break;
                                case 2:     // protocol version
                                        {
-                                               version = ntohs(*(u16 *) (b));
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Protocol version = %d\n", version);
+                                               version = ntohs(*(uint16_t *) (b));
+                                               LOG(4, s, t, "   Protocol version = %d\n", version);
                                                if (version && version != 0x0100)
                                                {   // allow 0.0 and 1.0
-                                                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "   Bad protocol version %04X\n",
-                                                                       version);
+                                                       LOG(1, s, t, "   Bad protocol version %04X\n", version);
                                                        fatal = flags;
+                                                       result = 5; // unspported protocol version
+                                                       error = 0x0100; // supported version
+                                                       msg = 0;
                                                        continue; // next
                                                }
                                        }
                                        break;
                                case 3:     // framing capabilities
-//                                     LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Framing capabilities\n");
+//                                     LOG(4, s, t, "Framing capabilities\n");
                                        break;
                                case 4:     // bearer capabilities
-//                                     LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Bearer capabilities\n");
+//                                     LOG(4, s, t, "Bearer capabilities\n");
                                        break;
                                case 5:         // tie breaker
                                        // We never open tunnels, so we don't care about tie breakers
-//                                     LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Tie breaker\n");
+//                                     LOG(4, s, t, "Tie breaker\n");
                                        continue;
                                case 6:     // firmware revision
-//                                     LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Firmware revision\n");
+//                                     LOG(4, s, t, "Firmware revision\n");
                                        break;
                                case 7:     // host name
-                                       memset(tunnel[t].hostname, 0, 128);
-                                       memcpy(tunnel[t].hostname, b, (n >= 127) ? 127 : n);
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
+                                       memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
+                                       memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
+                                       LOG(4, s, t, "   Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
                                        // TBA - to send to RADIUS
                                        break;
                                case 8:     // vendor name
                                        memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
-                                       memcpy(tunnel[t].vendor, b, (n >= sizeof(tunnel[t].vendor) - 1) ? sizeof(tunnel[t].vendor) - 1 : n);
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Vendor name = \"%s\"\n", tunnel[t].vendor);
+                                       memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
+                                       LOG(4, s, t, "   Vendor name = \"%s\"\n", tunnel[t].vendor);
                                        break;
                                case 9:     // assigned tunnel
-                                       tunnel[t].far = ntohs(*(u16 *) (b));
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Remote tunnel id = %d\n", tunnel[t].far);
+                                       tunnel[t].far = ntohs(*(uint16_t *) (b));
+                                       LOG(4, s, t, "   Remote tunnel id = %d\n", tunnel[t].far);
                                        break;
                                case 10:    // rx window
-                                       tunnel[t].window = ntohs(*(u16 *) (b));
+                                       tunnel[t].window = ntohs(*(uint16_t *) (b));
                                        if (!tunnel[t].window)
                                                tunnel[t].window = 1; // window of 0 is silly
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   rx window = %d\n", tunnel[t].window);
+                                       LOG(4, s, t, "   rx window = %d\n", tunnel[t].window);
                                        break;
                                case 11:        // Challenge
                                        {
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   LAC requested CHAP authentication for tunnel\n");
+                                               LOG(4, s, t, "   LAC requested CHAP authentication for tunnel\n");
                                                build_chap_response(b, 2, n, &chapresponse);
                                        }
                                        break;
                                case 13:    // Response
                                        // Why did they send a response? We never challenge.
-                                       LOG(2, ntohl(addr->sin_addr.s_addr), s, t, "   received unexpected challenge response\n");
+                                       LOG(2, s, t, "   received unexpected challenge response\n");
                                        break;
 
                                case 14:    // assigned session
-                                       asession = session[s].far = ntohs(*(u16 *) (b));
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   assigned session = %d\n", asession);
+                                       asession = session[s].far = ntohs(*(uint16_t *) (b));
+                                       LOG(4, s, t, "   assigned session = %d\n", asession);
                                        break;
                                case 15:    // call serial number
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   call serial number = %d\n", ntohl(*(u32 *)b));
+                                       LOG(4, s, t, "   call serial number = %d\n", ntohl(*(uint32_t *)b));
                                        break;
                                case 18:    // bearer type
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   bearer type = %d\n", ntohl(*(u32 *)b));
+                                       LOG(4, s, t, "   bearer type = %d\n", ntohl(*(uint32_t *)b));
                                        // TBA - for RADIUS
                                        break;
                                case 19:    // framing type
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   framing type = %d\n", ntohl(*(u32 *)b));
+                                       LOG(4, s, t, "   framing type = %d\n", ntohl(*(uint32_t *)b));
                                        // TBA
                                        break;
                                case 21:    // called number
-                                       memset(called, 0, MAXTEL);
-                                       memcpy(called, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Called <%s>\n", called);
+                                       memset(called, 0, sizeof(called));
+                                       memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
+                                       LOG(4, s, t, "   Called <%s>\n", called);
                                        break;
                                case 22:    // calling number
-                                       memset(calling, 0, MAXTEL);
-                                       memcpy(calling, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Calling <%s>\n", calling);
+                                       memset(calling, 0, sizeof(calling));
+                                       memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
+                                       LOG(4, s, t, "   Calling <%s>\n", calling);
                                        break;
                                case 23:    // subtype
                                        break;
                                case 24:    // tx connect speed
                                        if (n == 4)
                                        {
-                                               session[s].tx_connect_speed = ntohl(*(u32 *)b);
+                                               session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
                                        }
                                        else
                                        {
                                                // AS5300s send connect speed as a string
-                                               char tmp[30] = {0};
-                                               memcpy(tmp, b, (n >= 30) ? 30 : n);
+                                               char tmp[30];
+                                               memset(tmp, 0, sizeof(tmp));
+                                               memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
                                                session[s].tx_connect_speed = atol(tmp);
                                        }
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   TX connect speed <%u>\n",
-                                                       session[s].tx_connect_speed);
+                                       LOG(4, s, t, "   TX connect speed <%u>\n", session[s].tx_connect_speed);
                                        break;
                                case 38:    // rx connect speed
                                        if (n == 4)
                                        {
-                                               session[s].rx_connect_speed = ntohl(*(u32 *)b);
+                                               session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
                                        }
                                        else
                                        {
                                                // AS5300s send connect speed as a string
-                                               char tmp[30] = {0};
-                                               memcpy(tmp, b, (n >= 30) ? 30 : n);
+                                               char tmp[30];
+                                               memset(tmp, 0, sizeof(tmp));
+                                               memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
                                                session[s].rx_connect_speed = atol(tmp);
                                        }
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   RX connect speed <%u>\n",
-                                                       session[s].rx_connect_speed);
+                                       LOG(4, s, t, "   RX connect speed <%u>\n", session[s].rx_connect_speed);
                                        break;
                                case 25:    // Physical Channel ID
                                        {
-                                               u32 tmp = ntohl(*(u32 *)b);
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Physical Channel ID <%X>\n", tmp);
+                                               uint32_t tmp = ntohl(*(uint32_t *) b);
+                                               LOG(4, s, t, "   Physical Channel ID <%X>\n", tmp);
                                                break;
                                        }
                                case 29:    // Proxy Authentication Type
                                        {
-                                               u16 authtype = ntohs(*(u16 *)b);
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Proxy Auth Type %d (%s)\n",
-                                                       authtype, authtypes[authtype]);
-                                               requestchap = (authtype == 2);
+                                               uint16_t atype = ntohs(*(uint16_t *)b);
+                                               LOG(4, s, t, "   Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
+                                               if (atype == 2)
+                                                       authtype = AUTHCHAP;
+                                               else if (atype == 3)
+                                                       authtype = AUTHPAP;
+
                                                break;
                                        }
                                case 30:    // Proxy Authentication Name
                                        {
-                                               char authname[64] = {0};
-                                               memcpy(authname, b, (n > 63) ? 63 : n);
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Proxy Auth Name (%s)\n",
+                                               char authname[64];
+                                               memset(authname, 0, sizeof(authname));
+                                               memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
+                                               LOG(4, s, t, "   Proxy Auth Name (%s)\n",
                                                        authname);
                                                break;
                                        }
                                case 31:    // Proxy Authentication Challenge
                                        {
-                                               memcpy(radius[session[s].radius].auth, b, 16);
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Proxy Auth Challenge\n");
+                                               LOG(4, s, t, "   Proxy Auth Challenge\n");
+                                               if (sess_local[s].radius)
+                                                       memcpy(radius[sess_local[s].radius].auth, b, 16);
                                                break;
                                        }
                                case 32:    // Proxy Authentication ID
                                        {
-                                               u16 authid = ntohs(*(u16 *)(b));
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Proxy Auth ID (%d)\n",
-                                                       authid);
-                                               if (session[s].radius)
-                                                       radius[session[s].radius].id = authid;
+                                               uint16_t authid = ntohs(*(uint16_t *)(b));
+                                               LOG(4, s, t, "   Proxy Auth ID (%d)\n", authid);
+                                               if (sess_local[s].radius)
+                                                       radius[sess_local[s].radius].id = authid;
                                                break;
                                        }
                                case 33:    // Proxy Authentication Response
-                                       {
-                                               char authresp[64] = {0};
-                                               memcpy(authresp, b, (n > 63) ? 63 : n);
-                                               LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Proxy Auth Response\n");
-                                               break;
-                                       }
-                               case 27:    // last send lcp
+                                       LOG(4, s, t, "   Proxy Auth Response\n");
+                                       break;
+                               case 27:    // last sent lcp
                                        {        // find magic number
-                                               u8 *p = b, *e = p + n;
+                                               uint8_t *p = b, *e = p + n;
                                                while (p + 1 < e && p[1] && p + p[1] <= e)
                                                {
                                                        if (*p == 5 && p[1] == 6) // Magic-Number
-                                                               amagic = ntohl(*(u32 *) (p + 2));
-                                                       else if (*p == 3 && p[1] == 5 && *(u16 *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
-                                                               chap = 1;
+                                                               amagic = ntohl(*(uint32_t *) (p + 2));
+                                                       else if (*p == 3 && p[1] == 4 && *(uint16_t *) (p + 2) == htons(PPPPAP)) // Authentication-Protocol (PAP)
+                                                               authtype = AUTHPAP;
+                                                       else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol (CHAP)
+                                                               authtype = AUTHCHAP;
                                                        else if (*p == 7) // Protocol-Field-Compression
                                                                aflags |= SESSIONPFC;
                                                        else if (*p == 8) // Address-and-Control-Field-Compression
@@ -1692,20 +2246,26 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                case 39:    // seq required - we control it as an LNS anyway...
                                        break;
                                case 36:    // Random Vector
-                                       LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "   Random Vector received. Enabled AVP Hiding.\n");
+                                       LOG(4, s, t, "   Random Vector received.  Enabled AVP Hiding.\n");
                                        memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
                                        memcpy(session[s].random_vector, b, n);
                                        session[s].random_vector_length = n;
                                        break;
                                default:
-                                       LOG(2, ntohl(addr->sin_addr.s_addr), s, t, "   Unknown AVP type %d\n", mtype);
-                                       fatal = flags;
-                                       continue; // next
+                                       {
+                                               static char e[] = "unknown AVP 0xXXXX";
+                                               LOG(2, s, t, "   Unknown AVP type %d\n", mtype);
+                                               fatal = flags;
+                                               result = 2; // general error
+                                               error = 8; // unknown mandatory AVP
+                                               sprintf((msg = e) + 14, "%04x", mtype);
+                                               continue; // next
+                                       }
                                }
                        }
                        // process message
                        if (fatal & 0x80)
-                               tunnelshutdown(t, "Unknown Mandatory AVP");
+                               tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
                        else
                                switch (message)
                                {
@@ -1717,7 +2277,7 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                                controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
                                                if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
                                                control16(c, 9, t, 1); // assigned tunnel
-                                               controladd(c, t, s); // send the resply
+                                               controladd(c, t, 0); // send the resply
                                        }
                                        tunnel[t].state = TUNNELOPENING;
                                        break;
@@ -1730,8 +2290,7 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                        break;
                                case 4:       // StopCCN
                                        controlnull(t); // ack
-                                       tunnelshutdown(t, "Stopped"); // Shut down cleanly
-                                       tunnelkill(t, "Stopped"); // Immediately force everything dead
+                                       tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
                                        break;
                                case 6:       // HELLO
                                        controlnull(t); // simply ACK
@@ -1746,15 +2305,9 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                        // TBA
                                        break;
                                case 10:      // ICRQ
-                                       if (!sessionfree)
-                                       {
-                                               STAT(session_overflow);
-                                               tunnelshutdown(t, "No free sessions");
-                                       }
-                                       else
+                                       if (sessionfree)
                                        {
-                                               u16 r;
-                                               controlt *c;
+                                               uint16_t r;
 
                                                s = sessionfree;
                                                sessionfree = session[s].next;
@@ -1764,34 +2317,40 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                                        config->cluster_highest_sessionid = s;
 
                                                // make a RADIUS session
-                                               if (!(r = radiusnew(s)))
+                                               if ((r = radiusnew(s)))
                                                {
-                                                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "No free RADIUS sessions for ICRQ\n");
-                                                       sessionkill(s, "no free RADIUS sesions");
-                                                       return;
+                                                       controlt *c = controlnew(11); // sending ICRP
+                                                       session[s].opened = time_now;
+                                                       session[s].tunnel = t;
+                                                       session[s].far = asession;
+                                                       session[s].last_packet = time_now;
+                                                       LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
+                                                       control16(c, 14, s, 1); // assigned session
+                                                       controladd(c, t, asession); // send the reply
+
+                                                       strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
+                                                       strncpy(session[s].called, called, sizeof(session[s].called) - 1);
+                                                       strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
+                                                       STAT(session_created);
+                                                       break;
                                                }
 
-                                               c = controlnew(11); // sending ICRP
-                                               session[s].id = sessionid++;
-                                               session[s].opened = time(NULL);
-                                               session[s].tunnel = t;
-                                               session[s].far = asession;
-                                               session[s].last_packet = time_now;
-                                               LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
-                                               control16(c, 14, s, 1); // assigned session
-                                               controladd(c, t, s); // send the reply
-                                               {
-                                                       // Generate a random challenge
-                                                       int n;
-                                                       for (n = 0; n < 15; n++)
-                                                               radius[r].auth[n] = rand();
-                                               }
-                                               strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
-                                               strncpy(session[s].called, called, sizeof(session[s].called) - 1);
-                                               strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
-                                               STAT(session_created);
+
+                                               LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
+                                               sessionclear(s);
                                        }
-                                       break;
+                                       else
+                                       {
+                                               STAT(session_overflow);
+                                               LOG(1, 0, t, "No free sessions\n");
+                                       }
+
+                                       {
+                                               controlt *c = controlnew(14); // CDN
+                                               control16(c, 1, 4, 1); // temporary lack of resources
+                                               controladd(c, session[s].tunnel, asession); // send the message
+                                       }
+                                       return;
                                case 11:      // ICRP
                                        // TBA
                                        break;
@@ -1799,25 +2358,28 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                                        if (amagic == 0) amagic = time_now;
                                        session[s].magic = amagic; // set magic number
                                        session[s].l2tp_flags = aflags; // set flags received
-                                       LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Magic %X Flags %X\n", amagic, aflags);
+                                       LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
                                        controlnull(t); // ack
-                                       // In CHAP state, request PAP instead
-                                       if (requestchap)
-                                               initlcp(t, s);
+                                       // proxy authentication type is not supported
+                                       if (!(config->radius_authtypes & authtype))
+                                               authtype = config->radius_authprefer;
+
+                                       // start LCP
+                                       sendlcp(t, s, authtype);
                                        break;
                                case 14:      // CDN
                                        controlnull(t); // ack
-                                       sessionshutdown(s, "Closed (Received CDN)");
+                                       sessionshutdown(s, "Closed (Received CDN).", 0, 0);
                                        break;
                                case 0xFFFF:
-                                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Missing message type\n");
+                                       LOG(1, s, t, "Missing message type\n");
                                        break;
                                default:
                                        STAT(tunnel_rx_errors);
-                                       if (mandatorymessage & 0x80)
-                                               tunnelshutdown(t, "Unknown message");
+                                       if (mandatory)
+                                               tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
                                        else
-                                               LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unknown message type %d\n", message);
+                                               LOG(1, s, t, "Unknown message type %d\n", message);
                                        break;
                                }
                        if (chapresponse) free(chapresponse);
@@ -1825,12 +2387,12 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                }
                else
                {
-                       LOG(4, 0, s, t, "   Got a ZLB ack\n");
+                       LOG(4, s, t, "   Got a ZLB ack\n");
                }
        }
        else
        {                          // data
-               u16 prot;
+               uint16_t prot;
 
                LOG_HEX(5, "Receive Tunnel Data", p, l);
                if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
@@ -1840,7 +2402,7 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                }
                if (l < 2)
                {
-                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Short ppp length %d\n", l);
+                       LOG(1, s, t, "Short ppp length %d\n", l);
                        STAT(tunnel_rx_errors);
                        return;
                }
@@ -1851,12 +2413,12 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                }
                else
                {
-                       prot = ntohs(*(u16 *) p);
+                       prot = ntohs(*(uint16_t *) p);
                        p += 2;
                        l -= 2;
                }
 
-               if (s && !session[s].tunnel)    // Is something wrong??
+               if (s && !session[s].opened)    // Is something wrong??
                {
                        if (!config->cluster_iam_master)
                        {
@@ -1866,19 +2428,11 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                        }
 
 
-                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "UDP packet contains session %d "
-                                       "but no session[%d].tunnel exists (LAC said"
-                                       " tunnel = %d). Dropping packet.\n", s, s, t);
+                       LOG(1, s, t, "UDP packet contains session which is not opened.  Dropping packet.\n");
                        STAT(tunnel_rx_errors);
                        return;
                }
 
-               if (session[s].die)
-               {
-                       LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Session %d is closing. Don't process PPP packets\n", s);
-// I'm pretty sure this isn't right -- mo.
-//                     return;              // closing session, PPP not processed
-               }
                if (prot == PPPPAP)
                {
                        session[s].last_packet = time_now;
@@ -1903,6 +2457,19 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                        if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
                        processipcp(t, s, p, l);
                }
+               else if (prot == PPPIPV6CP)
+               {
+                       if (config->ipv6_prefix.s6_addr[0] > 0)
+                       {
+                               session[s].last_packet = time_now;
+                               if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+                               processipv6cp(t, s, p, l);
+                       }
+                       else
+                       {
+                               LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
+                       }
+               }
                else if (prot == PPPCCP)
                {
                        session[s].last_packet = time_now;
@@ -1911,42 +2478,75 @@ void processudp(u8 * buf, int len, struct sockaddr_in *addr)
                }
                else if (prot == PPPIP)
                {
+                       if (session[s].die)
+                       {
+                               LOG(4, s, t, "Session %d is closing.  Don't process PPP packets\n", s);
+                               return;              // closing session, PPP not processed
+                       }
+
                        session[s].last_packet = time_now;
                        if (session[s].walled_garden && !config->cluster_iam_master)
                        {
                                master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
                                return;
                        }
+
                        processipin(t, s, p, l);
                }
+               else if (prot == PPPIPV6)
+               {
+                       if (!config->ipv6_prefix.s6_addr[0] > 0)
+                       {
+                               LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
+                               return;
+                       }
+                       if (session[s].die)
+                       {
+                               LOG(4, s, t, "Session %d is closing.  Don't process PPP packets\n", s);
+                               return;              // closing session, PPP not processed
+                       }
+
+                       session[s].last_packet = time_now;
+                       if (session[s].walled_garden && !config->cluster_iam_master)
+                       {
+                               master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+                               return;
+                       }
+
+                       processipv6in(t, s, p, l);
+               }
                else
                {
                        STAT(tunnel_rx_errors);
-                       LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unknown PPP protocol %04X\n", prot);
+                       LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
                }
        }
 }
 
 // read and process packet on tun
-static void processtun(u8 * buf, int len)
+static void processtun(uint8_t * buf, int len)
 {
        LOG_HEX(5, "Receive TUN Data", buf, len);
        STAT(tun_rx_packets);
        INC_STAT(tun_rx_bytes, len);
 
-       CSTAT(call_processtun);
+       CSTAT(processtun);
 
        eth_rx_pkt++;
        eth_rx += len;
        if (len < 22)
        {
-               LOG(1, 0, 0, 0, "Short tun packet %d bytes\n", len);
+               LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
                STAT(tun_rx_errors);
                return;
        }
 
-       if (*(u16 *) (buf + 2) == htons(PKTIP)) // IP
+       if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
                processipout(buf, len);
+       else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
+           && config->ipv6_prefix.s6_addr[0] > 0)
+               processipv6out(buf, len);
+
        // Else discard.
 }
 
@@ -1961,11 +2561,12 @@ static int regular_cleanups(void)
        static sessionidt s = 0;        // Next session to check for actions on.
        tunnelidt t;
        int count=0,i;
-       u16 r;
+       uint16_t r;
        static clockt next_acct = 0;
+       static clockt next_shut_acct = 0;
        int a;
 
-       LOG(3, 0, 0, 0, "Begin regular cleanup\n");
+       LOG(3, 0, 0, "Begin regular cleanup\n");
 
        for (r = 1; r < MAXRADIUS; r++)
        {
@@ -1994,7 +2595,7 @@ static int regular_cleanups(void)
                        if (tunnel[t].retry <= TIME)
                        {
                                controlt *c = tunnel[t].controls;
-                               u8 w = tunnel[t].window;
+                               uint8_t w = tunnel[t].window;
                                tunnel[t].try++; // another try
                                if (tunnel[t].try > 5)
                                        tunnelkill(t, "Timeout on control message"); // game over
@@ -2011,7 +2612,7 @@ static int regular_cleanups(void)
                {
                        controlt *c = controlnew(6); // sending HELLO
                        controladd(c, t, 0); // send the message
-                       LOG(3, tunnel[t].ip, 0, t, "Sending HELLO message\n");
+                       LOG(3, 0, t, "Sending HELLO message\n");
                }
 
                // Check for tunnel changes requested from the CLI
@@ -2020,8 +2621,8 @@ static int regular_cleanups(void)
                        cli_tunnel_actions[t].action = 0;
                        if (a & CLI_TUN_KILL)
                        {
-                               LOG(2, tunnel[t].ip, 0, t, "Dropping tunnel by CLI\n");
-                               tunnelshutdown(t, "Requested by administrator");
+                               LOG(2, 0, t, "Dropping tunnel by CLI\n");
+                               tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
                        }
                }
 
@@ -2034,51 +2635,50 @@ static int regular_cleanups(void)
                if (s > config->cluster_highest_sessionid)
                        s = 1;
 
-               if (!session[s].tunnel) // Session isn't in use
+               if (!session[s].opened) // Session isn't in use
                        continue;
 
-               if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
+               // check for expired sessions
+               if (session[s].die)
                {
-                       // IPCP has not completed yet. Resend
-                       LOG(3, session[s].ip, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
-                       sendipcp(session[s].tunnel, s);
+                       if (session[s].die <= TIME)
+                       {
+                               sessionkill(s, "Expired");
+                               if (++count >= MAX_ACTIONS) break;
+                       }
+                       continue;
                }
 
-               // check for expired sessions
-               if (session[s].die && session[s].die <= TIME)
+               if (session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
                {
-                       sessionkill(s, "Expired");
-                       if (++count >= MAX_ACTIONS) break;
-                       continue;
+                       // IPCP has not completed yet. Resend
+                       LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
+                       sendipcp(session[s].tunnel, s);
                }
 
                // Drop sessions who have not responded within IDLE_TIMEOUT seconds
                if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
                {
-                       sessionkill(s, "No response to LCP ECHO requests");
+                       sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
                        STAT(session_timeout);
                        if (++count >= MAX_ACTIONS) break;
                        continue;
                }
 
-               // No data in IDLE_TIMEOUT seconds, send LCP ECHO
+               // No data in ECHO_TIMEOUT seconds, send LCP ECHO
                if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
                {
-                       u8 b[MAXCONTROL] = {0};
+                       uint8_t b[MAXCONTROL] = {0};
 
-                       u8 *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
-                       if (!q)
-                       {
-                               LOG(3, session[s].ip, s, t, "failed to send ECHO packet.\n");
-                               continue;
-                       }
+                       uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
+                       if (!q) continue;
 
                        *q = EchoReq;
-                       *(u8 *)(q + 1) = (time_now % 255); // ID
-                       *(u16 *)(q + 2) = htons(8); // Length
-                       *(u32 *)(q + 4) = 0; // Magic Number (not supported)
+                       *(uint8_t *)(q + 1) = (time_now % 255); // ID
+                       *(uint16_t *)(q + 2) = htons(8); // Length
+                       *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
 
-                       LOG(4, session[s].ip, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
+                       LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
                                        (int)(time_now - session[s].last_packet));
                        tunnelsend(b, 24, session[s].tunnel); // send it
                        if (++count >= MAX_ACTIONS) break;
@@ -2092,22 +2692,23 @@ static int regular_cleanups(void)
                        cli_session_actions[s].action = 0;
                        if (a & CLI_SESS_KILL)
                        {
-                               LOG(2, 0, s, session[s].tunnel, "Dropping session by CLI\n");
-                               sessionshutdown(s, "Requested by administrator");
+                               LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
+                               sessionshutdown(s, "Requested by administrator.", 3, 0);
                                a = 0; // dead, no need to check for other actions
                        }
 
                        if (a & CLI_SESS_NOSNOOP)
                        {
-                               LOG(2, 0, s, session[s].tunnel, "Unsnooping session by CLI\n");
+                               LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
                                session[s].snoop_ip = 0;
                                session[s].snoop_port = 0;
                                send++;
                        }
                        else if (a & CLI_SESS_SNOOP)
                        {
-                               LOG(2, 0, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
-                                   inet_toa(cli_session_actions[s].snoop_ip), cli_session_actions[s].snoop_port);
+                               LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
+                                   fmtaddr(cli_session_actions[s].snoop_ip, 0),
+                                   cli_session_actions[s].snoop_port);
 
                                session[s].snoop_ip = cli_session_actions[s].snoop_ip;
                                session[s].snoop_port = cli_session_actions[s].snoop_port;
@@ -2116,13 +2717,13 @@ static int regular_cleanups(void)
 
                        if (a & CLI_SESS_NOTHROTTLE)
                        {
-                               LOG(2, 0, s, session[s].tunnel, "Un-throttling session by CLI\n");
+                               LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
                                throttle_session(s, 0, 0);
                                send++;
                        }
                        else if (a & CLI_SESS_THROTTLE)
                        {
-                               LOG(2, 0, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
+                               LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
                                    cli_session_actions[s].throttle_in,
                                    cli_session_actions[s].throttle_out);
 
@@ -2130,24 +2731,74 @@ static int regular_cleanups(void)
                                send++;
                        }
 
+                       if (a & CLI_SESS_NOFILTER)
+                       {
+                               LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
+                               filter_session(s, 0, 0);
+                               send++;
+                       }
+                       else if (a & CLI_SESS_FILTER)
+                       {
+                               LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
+                                   cli_session_actions[s].filter_in,
+                                   cli_session_actions[s].filter_out);
+
+                               filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
+                               send++;
+                       }
+
                        if (send)
                                cluster_send_session(s);
 
                        if (++count >= MAX_ACTIONS) break;
                }
+
+               // RADIUS interim accounting
+               if (config->radius_accounting && config->radius_interim > 0
+                   && session[s].ip && !session[s].walled_garden
+                   && !sess_local[s].radius // RADIUS already in progress
+                   && time_now - sess_local[s].last_interim >= config->radius_interim)
+               {
+                       if (!(r = radiusnew(s)))
+                       {
+                               LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
+                               STAT(radius_overflow);
+                               continue;
+                       }
+
+                       LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
+                               session[s].user, session[s].unique_id);
+
+                       radiussend(r, RADIUSINTERIM);
+                       sess_local[s].last_interim = time_now;
+
+                       if (++count >= MAX_ACTIONS)
+                               break;
+               }
        }
 
-       if (*config->accounting_dir && next_acct <= TIME)
+       if (*config->accounting_dir)
        {
-               // Dump accounting data
-               next_acct = TIME + ACCT_TIME;
-               dump_acct_info();
+               if (next_acct <= TIME)
+               {
+                       // Dump accounting data
+                       next_acct = TIME + ACCT_TIME;
+                       next_shut_acct = TIME + ACCT_SHUT_TIME;
+                       dump_acct_info(1);
+               }
+               else if (next_shut_acct <= TIME)
+               {
+                       // Dump accounting data for shutdown sessions
+                       next_shut_acct = TIME + ACCT_SHUT_TIME;
+                       if (shut_acct_n)
+                               dump_acct_info(0);
+               }
        }
 
        if (count >= MAX_ACTIONS)
                return 1;       // Didn't finish!
 
-       LOG(3, 0, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
+       LOG(3, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
        return 0;
 }
 
@@ -2171,7 +2822,7 @@ static int still_busy(void)
 
                if (last_talked != TIME)
                {
-                       LOG(2,0,0,0, "Tunnel %d still has un-acked control messages.\n", i);
+                       LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
                        last_talked = TIME;
                }
                return 1;
@@ -2180,7 +2831,7 @@ static int still_busy(void)
        // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
        if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
        {
-               LOG(1, 0, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
+               LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty.  Shutting down anyway.\n");
                return 0;
        }
 
@@ -2193,7 +2844,7 @@ static int still_busy(void)
 
                if (last_talked != TIME)
                {
-                       LOG(2,0,0,0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
+                       LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
                        last_talked = TIME;
                }
                return 1;
@@ -2209,13 +2860,13 @@ static int readset_n = 0;
 static void mainloop(void)
 {
        int i;
-       u8 buf[65536];
+       uint8_t buf[65536];
        struct timeval to;
        clockt next_cluster_ping = 0;   // send initial ping immediately
        time_t next_clean = time_now + config->cleanup_interval;
 
-       LOG(4, 0, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
-                       udpfd, tunfd, cluster_sockfd, controlfd);
+       LOG(4, 0, 0, "Beginning of main loop.  udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
+               udpfd, tunfd, cluster_sockfd, controlfd);
 
        FD_ZERO(&readset);
        FD_SET(udpfd, &readset);
@@ -2273,6 +2924,8 @@ static void mainloop(void)
                n = select(n + 1, &r, 0, 0, &to);
 #endif /* BGP */
 
+               STAT(select_called);
+
                TIME = now();
                if (n < 0)
                {
@@ -2280,69 +2933,127 @@ static void mainloop(void)
                            errno == ECHILD) // EINTR was clobbered by sigchild_handler()
                                continue;
 
-                       LOG(0, 0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
+                       LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
                        main_quit++;
                        break;
                }
                else if (n)
                {
                        struct sockaddr_in addr;
-                       int alen = sizeof(addr);
-                       if (FD_ISSET(udpfd, &r))
-                       {
-                               int c, n;
-                               for (c = 0; c < config->multi_read_count; c++)
-                               {
-                                       if ((n = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
-                                               processudp(buf, n, &addr);
-                                       else
-                                               break;
-                               }
-                       }
-                       if (FD_ISSET(tunfd, &r))
+                       int alen, c, s;
+                       int udp_pkts = 0;
+                       int tun_pkts = 0;
+                       int cluster_pkts = 0;
+
+                       // nsctl commands
+                       if (FD_ISSET(controlfd, &r))
                        {
-                               int c, n;
-                               for (c = 0; c < config->multi_read_count; c++)
-                               {
-                                       if ((n = read(tunfd, buf, sizeof(buf))) > 0)
-                                               processtun(buf, n);
-                                       else
-                                               break;
-                               }
+                               alen = sizeof(addr);
+                               processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+                               n--;
                        }
 
+                       // RADIUS responses
                        if (config->cluster_iam_master)
+                       {
                                for (i = 0; i < config->num_radfds; i++)
+                               {
                                        if (FD_ISSET(radfds[i], &r))
+                                       {
                                                processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
+                                               n--;
+                                       }
+                               }
+                       }
 
-                       if (FD_ISSET(cluster_sockfd, &r))
+                       // CLI connections
+                       if (FD_ISSET(clifd, &r))
                        {
-                               int size;
-                               size = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen);
-                               processcluster(buf, size, addr.sin_addr.s_addr);
+                               int cli;
+                               
+                               alen = sizeof(addr);
+                               if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
+                               {
+                                       cli_do(cli);
+                                       close(cli);
+                               }
+                               else
+                                       LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
+
+                               n--;
                        }
 
-                       if (FD_ISSET(controlfd, &r))
-                               processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr);
+#ifdef BGP
+                       for (i = 0; i < BGP_NUM_PEERS; i++)
+                       {
+                               int isr = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0;
+                               int isw = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0;
+                               bgp_process(&bgp_peers[i], isr, isw);
+                               if (isr) n--;
+                               if (isw) n--;
+                       }
+#endif /* BGP */
 
-                       if (FD_ISSET(clifd, &r))
+                       for (c = 0; n && c < config->multi_read_count; c++)
                        {
-                               struct sockaddr_in addr;
-                               int sockfd;
-                               int len = sizeof(addr);
+                               // L2TP
+                               if (FD_ISSET(udpfd, &r))
+                               {
+                                       alen = sizeof(addr);
+                                       if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
+                                       {
+                                               processudp(buf, s, &addr);
+                                               udp_pkts++;
+                                       }
+                                       else
+                                       {
+                                               FD_CLR(udpfd, &r);
+                                               n--;
+                                       }
+                               }
 
-                               if ((sockfd = accept(clifd, (struct sockaddr *)&addr, &len)) <= 0)
+                               // incoming IP
+                               if (FD_ISSET(tunfd, &r))
                                {
-                                       LOG(0, 0, 0, 0, "accept error: %s\n", strerror(errno));
-                                       continue;
+                                       if ((s = read(tunfd, buf, sizeof(buf))) > 0)
+                                       {
+                                               processtun(buf, s);
+                                               tun_pkts++;
+                                       }
+                                       else
+                                       {
+                                               FD_CLR(tunfd, &r);
+                                               n--;
+                                       }
                                }
-                               else
+
+                               // cluster
+                               if (FD_ISSET(cluster_sockfd, &r))
                                {
-                                       cli_do(sockfd);
-                                       close(sockfd);
+                                       alen = sizeof(addr);
+                                       if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
+                                       {
+                                               processcluster(buf, s, addr.sin_addr.s_addr);
+                                               cluster_pkts++;
+                                       }
+                                       else
+                                       {
+                                               FD_CLR(cluster_sockfd, &r);
+                                               n--;
+                                       }
                                }
                        }
+
+                       if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
+                               STAT(multi_read_used);
+
+                       if (c >= config->multi_read_count)
+                       {
+                               LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
+                                       config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
+
+                               STAT(multi_read_exceeded);
+                       }
                }
 
                        // Runs on every machine (master and slaves).
@@ -2392,15 +3103,6 @@ static void mainloop(void)
                                next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
                        }
                }
-
-#ifdef BGP
-               for (i = 0; i < BGP_NUM_PEERS; i++)
-               {
-                       bgp_process(&bgp_peers[i],
-                               bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0,
-                               bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0);
-               }
-#endif /* BGP */
        }
 
                // Are we the master and shutting down??
@@ -2485,71 +3187,82 @@ static void initdata(int optdebug, char *optconfig)
 {
        int i;
 
-       if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
-       {
-               LOG(0, 0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
-               exit(1);
-       }
-       if (!(config = shared_malloc(sizeof(struct configt))))
+       if (!(config = shared_malloc(sizeof(configt))))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for configuration: %s\n", strerror(errno));
+               fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
                exit(1);
        }
-       memset(config, 0, sizeof(struct configt));
+
+       memset(config, 0, sizeof(configt));
        time(&config->start_time);
        strncpy(config->config_file, optconfig, strlen(optconfig));
        config->debug = optdebug;
        config->num_tbfs = MAXTBFS;
        config->rl_rate = 28; // 28kbps
+       strcpy(config->random_device, RANDOMDEVICE);
 
-       if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
+       log_stream = stderr;
+
+#ifdef RINGBUFFER
+       if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
+               exit(1);
+       }
+       memset(ringbuffer, 0, sizeof(struct Tringbuffer));
+#endif
+
+       if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
+       {
+               LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
+               exit(1);
+       }
+       if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
+       {
+               LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
                exit(1);
        }
        if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
                exit(1);
        }
 
-       if (!(sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION)))
+       if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for sessions_count: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
                exit(1);
        }
 
        if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
                exit(1);
        }
 
        if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
                exit(1);
        }
 
-#ifdef RINGBUFFER
-       if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
+       if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
                exit(1);
        }
-       memset(ringbuffer, 0, sizeof(struct Tringbuffer));
-#endif
+       memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
 
        if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
                exit(1);
        }
        memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
 
        if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
        {
-               LOG(0, 0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
                exit(1);
        }
        memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
@@ -2560,7 +3273,7 @@ static void initdata(int optdebug, char *optconfig)
        memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
 
                // Put all the sessions on the free list marked as undefined.
-       for (i = 1; i < MAXSESSION - 1; i++)
+       for (i = 1; i < MAXSESSION; i++)
        {
                session[i].next = i + 1;
                session[i].tunnel = T_UNDEF;    // mark it as not filled in.
@@ -2569,7 +3282,7 @@ static void initdata(int optdebug, char *optconfig)
        sessionfree = 1;
 
                // Mark all the tunnels as undefined (waiting to be filled in by a download).
-       for (i = 1; i < MAXTUNNEL- 1; i++)
+       for (i = 1; i < MAXTUNNEL; i++)
                tunnel[i].state = TUNNELUNDEF;  // mark it as not filled in.
 
        if (!*hostname)
@@ -2582,24 +3295,24 @@ static void initdata(int optdebug, char *optconfig)
        _statistics->start_time = _statistics->last_reset = time(NULL);
 
 #ifdef BGP
-       if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
-       {
-               LOG(0, 0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
-               exit(1);
-       }
+       if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
+       {
+               LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
+               exit(1);
+       }
 #endif /* BGP */
 }
 
 static int assign_ip_address(sessionidt s)
 {
-       u32 i;
+       uint32_t i;
        int best = -1;
        time_t best_time = time_now;
        char *u = session[s].user;
        char reuse = 0;
 
 
-       CSTAT(call_assign_ip_address);
+       CSTAT(assign_ip_address);
 
        for (i = 1; i < ip_pool_size; i++)
        {
@@ -2623,7 +3336,7 @@ static int assign_ip_address(sessionidt s)
 
        if (best < 0)
        {
-               LOG(0, 0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
+               LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
                return 0;
        }
 
@@ -2641,8 +3354,8 @@ static int assign_ip_address(sessionidt s)
                strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
 
        STAT(ip_allocated);
-       LOG(4, ip_address_pool[best].address, s, session[s].tunnel,
-               "assign_ip_address(): %s ip address %d from pool\n", reuse ? "Reusing" : "Allocating", best);
+       LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
+               reuse ? "Reusing" : "Allocating", best);
 
        return 1;
 }
@@ -2652,7 +3365,7 @@ static void free_ip_address(sessionidt s)
        int i = session[s].ip_pool_index;
 
 
-       CSTAT(call_free_ip_address);
+       CSTAT(free_ip_address);
 
        if (!session[s].ip)
                return; // what the?
@@ -2695,8 +3408,9 @@ void rebuild_address_pool(void)
        for (i = 0; i < MAXSESSION; ++i)
        {
                int ipid;
-               if (!session[i].ip || !session[i].tunnel)
+               if (!(session[i].opened && session[i].ip))
                        continue;
+
                ipid = - lookup_ipmap(htonl(session[i].ip));
 
                if (session[i].ip_pool_index < 0)
@@ -2705,8 +3419,8 @@ void rebuild_address_pool(void)
                        if (ipid < 1)                   // Not found in the pool either? good.
                                continue;
 
-                       LOG(0, 0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
-                               i, inet_toa(session[i].ip), ipid);
+                       LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
+                               i, fmtaddr(session[i].ip, 0), ipid);
 
                        // Fall through and process it as part of the pool.
                }
@@ -2714,7 +3428,7 @@ void rebuild_address_pool(void)
 
                if (ipid > MAXIPPOOL || ipid < 0)
                {
-                       LOG(0, 0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
+                       LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
                        ipid = -1;
                        session[i].ip_pool_index = ipid;
                        continue;
@@ -2753,7 +3467,7 @@ static void fix_address_pool(int sid)
 //
 // Add a block of addresses to the IP pool to hand out.
 //
-static void add_to_ip_pool(u32 addr, u32 mask)
+static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
 {
        int i;
        if (mask == 0)
@@ -2774,7 +3488,7 @@ static void add_to_ip_pool(u32 addr, u32 mask)
                ++ip_pool_size;
                if (ip_pool_size >= MAXIPPOOL)
                {
-                       LOG(0,0,0,0, "Overflowed IP pool adding %s\n", inet_toa(htonl(addr)) );
+                       LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
                        return;
                }
        }
@@ -2790,7 +3504,7 @@ static void initippool()
 
        if (!(f = fopen(IPPOOLFILE, "r")))
        {
-               LOG(0, 0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
+               LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
                exit(1);
        }
 
@@ -2804,12 +3518,12 @@ static void initippool()
                if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
                if ((p = (char *)strchr(buf, ':')))
                {
-                       ipt src;
+                       in_addr_t src;
                        *p = '\0';
                        src = inet_addr(buf);
                        if (src == INADDR_NONE)
                        {
-                               LOG(0, 0, 0, 0, "Invalid address pool IP %s\n", buf);
+                               LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
                                exit(1);
                        }
                        // This entry is for a specific IP only
@@ -2822,20 +3536,22 @@ static void initippool()
                {
                        // It's a range
                        int numbits = 0;
-                       u32 start = 0, mask = 0;
+                       in_addr_t start = 0, mask = 0;
 
-                       LOG(2, 0, 0, 0, "Adding IP address range %s\n", buf);
+                       LOG(2, 0, 0, "Adding IP address range %s\n", buf);
                        *p++ = 0;
                        if (!*p || !(numbits = atoi(p)))
                        {
-                               LOG(0, 0, 0, 0, "Invalid pool range %s\n", buf);
+                               LOG(0, 0, 0, "Invalid pool range %s\n", buf);
                                continue;
                        }
                        start = ntohl(inet_addr(pool));
-                       mask = (u32)(pow(2, numbits) - 1) << (32 - numbits);
+                       mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
 
                        // Add a static route for this pool
-                       LOG(5, 0, 0, 0, "Adding route for address pool %s/%u\n", inet_toa(htonl(start)), 32 + mask);
+                       LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
+                               fmtaddr(htonl(start), 0), 32 + mask);
+
                        routeset(0, start, mask, 0, 1);
 
                        add_to_ip_pool(start, mask);
@@ -2847,10 +3563,10 @@ static void initippool()
                }
        }
        fclose(f);
-       LOG(1, 0, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
+       LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
 }
 
-void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port)
+void snoop_send_packet(char *packet, uint16_t size, in_addr_t destination, uint16_t port)
 {
        struct sockaddr_in snoop_addr = {0};
        if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
@@ -2860,62 +3576,81 @@ void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port)
        snoop_addr.sin_addr.s_addr = destination;
        snoop_addr.sin_port = ntohs(port);
 
-       LOG(5, 0, 0, 0, "Snooping packet at %p (%d bytes) to %s:%d\n",
-                       packet, size, inet_toa(snoop_addr.sin_addr.s_addr), htons(snoop_addr.sin_port));
+       LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
+               fmtaddr(snoop_addr.sin_addr.s_addr, 0),
+               htons(snoop_addr.sin_port));
+
        if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
-               LOG(0, 0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
+               LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
+
        STAT(packets_snooped);
 }
 
-static void dump_acct_info()
+static int dump_session(FILE **f, sessiont *s)
 {
-       char filename[1024];
-       char timestr[64];
-       time_t t = time(NULL);
-       int i;
-       FILE *f = NULL;
-
+       if (!s->opened || !s->ip || !(s->cin || s->cout) || !*s->user || s->walled_garden)
+               return 1;
 
-       CSTAT(call_dump_acct_info);
+       if (!*f)
+       {
+               char filename[1024];
+               char timestr[64];
+               time_t now = time(NULL);
 
-       strftime(timestr, 64, "%Y%m%d%H%M%S", localtime(&t));
-       snprintf(filename, 1024, "%s/%s", config->accounting_dir, timestr);
+               strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
+               snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
 
-       for (i = 0; i < MAXSESSION; i++)
-       {
-               if (!session[i].opened || !session[i].ip || !(session[i].cin || session[i].cout) || !*session[i].user || session[i].walled_garden)
-                       continue;
-               if (!f)
+               if (!(*f = fopen(filename, "w")))
                {
-                       time_t now = time(NULL);
-                       if (!(f = fopen(filename, "w")))
-                       {
-                               LOG(0, 0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
-                               return ;
-                       }
-                       LOG(3, 0, 0, 0, "Dumping accounting information to %s\n", filename);
-                       fprintf(f, "# dslwatch.pl dump file V1.01\n"
-                               "# host: %s\n"
-                               "# time: %ld\n"
-                               "# uptime: %ld\n"
-                               "# format: username ip qos uptxoctets downrxoctets\n",
-                               hostname,
-                               now,
-                               now - basetime);
+                       LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
+                       return 0;
                }
 
-               LOG(4, 0, 0, 0, "Dumping accounting information for %s\n", session[i].user);
-               fprintf(f, "%s %s %d %u %u\n",
-                       session[i].user,                                                // username
-                       inet_toa(htonl(session[i].ip)),                                 // ip
-                       (session[i].throttle_in || session[i].throttle_out) ? 2 : 1,    // qos
-                       (u32)session[i].cin,                                            // uptxoctets
-                       (u32)session[i].cout);                                          // downrxoctets
+               LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
+               fprintf(*f, "# dslwatch.pl dump file V1.01\n"
+                       "# host: %s\n"
+                       "# time: %ld\n"
+                       "# uptime: %ld\n"
+                       "# format: username ip qos uptxoctets downrxoctets\n",
+                       hostname,
+                       now,
+                       now - basetime);
+       }
+
+       LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
+       fprintf(*f, "%s %s %d %u %u\n",
+               s->user,                                                // username
+               fmtaddr(htonl(s->ip), 0),                               // ip
+               (s->throttle_in || s->throttle_out) ? 2 : 1,            // qos
+               (uint32_t) s->cin,                                      // uptxoctets
+               (uint32_t) s->cout);                                    // downrxoctets
+
+       s->pin = s->cin = 0;
+       s->pout = s->cout = 0;
+
+       return 1;
+}
+
+static void dump_acct_info(int all)
+{
+       int i;
+       FILE *f = NULL;
+
+
+       CSTAT(dump_acct_info);
 
-               session[i].pin = session[i].cin = 0;
-               session[i].pout = session[i].cout = 0;
+       if (shut_acct_n)
+       {
+               for (i = 0; i < shut_acct_n; i++)
+                       dump_session(&f, &shut_acct[i]);
+
+               shut_acct_n = 0;
        }
 
+       if (all)
+               for (i = 1; i <= config->cluster_highest_sessionid; i++)
+                       dump_session(&f, &session[i]);
+
        if (f)
                fclose(f);
 }
@@ -2934,32 +3669,31 @@ int main(int argc, char *argv[])
        {
                switch (i)
                {
-                       case 'd':
-                               if (fork()) exit(0);
-                               setsid();
-                               freopen("/dev/null", "r", stdin);
-                               freopen("/dev/null", "w", stdout);
-                               freopen("/dev/null", "w", stderr);
-                               break;
-                       case 'v':
-                               optdebug++;
-                               break;
-                       case 'c':
-                               optconfig = optarg;
-                               break;
-                       case 'h':
-                               snprintf(hostname, sizeof(hostname), "%s", optarg);
-                               break;
-                       default:
-                               printf("Args are:\n"
-                                      "\t-d\tDetach from terminal\n"
-                                      "\t-c <file>\tConfig file\n"
-                                      "\t-h <hostname>\tForce hostname\n"
-                                      "\t-a <address>\tUse specific address\n"
-                                      "\t-v\t\tDebug\n");
-
-                               return (0);
-                               break;
+               case 'd':
+                       if (fork()) exit(0);
+                       setsid();
+                       freopen("/dev/null", "r", stdin);
+                       freopen("/dev/null", "w", stdout);
+                       freopen("/dev/null", "w", stderr);
+                       break;
+               case 'v':
+                       optdebug++;
+                       break;
+               case 'c':
+                       optconfig = optarg;
+                       break;
+               case 'h':
+                       snprintf(hostname, sizeof(hostname), "%s", optarg);
+                       break;
+               default:
+                       printf("Args are:\n"
+                              "\t-d\t\tDetach from terminal\n"
+                              "\t-c <file>\tConfig file\n"
+                              "\t-h <hostname>\tForce hostname\n"
+                              "\t-v\t\tDebug\n");
+
+                       return (0);
+                       break;
                }
        }
 
@@ -2976,16 +3710,17 @@ int main(int argc, char *argv[])
        read_config_file();
        init_tbf(config->num_tbfs);
 
-       LOG(0, 0, 0, 0, "L2TPNS version " VERSION "\n");
-       LOG(0, 0, 0, 0, "Copyright (c) 2003, 2004 Optus Internet Engineering\n");
-       LOG(0, 0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
+       LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
+       LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
+       LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
        {
                struct rlimit rlim;
                rlim.rlim_cur = RLIM_INFINITY;
                rlim.rlim_max = RLIM_INFINITY;
                // Remove the maximum core size
                if (setrlimit(RLIMIT_CORE, &rlim) < 0)
-                       LOG(0, 0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
+                       LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
+
                // Make core dumps go to /tmp
                chdir("/tmp");
        }
@@ -2998,18 +3733,18 @@ int main(int argc, char *argv[])
 
                if (get_nprocs() < 2)
                {
-                       LOG(0, 0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
+                       LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
                        config->scheduler_fifo = 0;
                }
                else
                {
                        if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
                        {
-                               LOG(1, 0, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
+                               LOG(1, 0, 0, "Using FIFO scheduler.  Say goodbye to any other processes running\n");
                        }
                        else
                        {
-                               LOG(0, 0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
+                               LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
                                config->scheduler_fifo = 0;
                        }
                }
@@ -3033,14 +3768,12 @@ int main(int argc, char *argv[])
 #endif /* BGP */
 
        inittun();
-       LOG(1, 0, 0, 0, "Set up on interface %s\n", config->tundevice);
+       LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
 
        initudp();
        initrad();
        initippool();
 
-       read_state();
-
        signal(SIGHUP, sighup_handler);
        signal(SIGTERM, sigterm_handler);
        signal(SIGINT, sigterm_handler);
@@ -3051,9 +3784,9 @@ int main(int argc, char *argv[])
        if (config->lock_pages)
        {
                if (!mlockall(MCL_CURRENT))
-                       LOG(1, 0, 0, 0, "Locking pages into memory\n");
+                       LOG(1, 0, 0, "Locking pages into memory\n");
                else
-                       LOG(0, 0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
+                       LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
        }
 
        alarm(1);
@@ -3087,9 +3820,11 @@ int main(int argc, char *argv[])
 
 static void sighup_handler(int sig)
 {
-       if (log_stream && log_stream != stderr)
+       if (log_stream)
        {
-               fclose(log_stream);
+               if (log_stream != stderr)
+                       fclose(log_stream);
+
                log_stream = NULL;
        }
 
@@ -3131,10 +3866,7 @@ static void sigalrm_handler(int sig)
 
 static void sigterm_handler(int sig)
 {
-       LOG(1, 0, 0, 0, "Shutting down cleanly\n");
-       if (config->save_state)
-               dump_state();
-
+       LOG(1, 0, 0, "Shutting down cleanly\n");
        main_quit++;
 }
 
@@ -3142,215 +3874,43 @@ static void sigquit_handler(int sig)
 {
        int i;
 
-       LOG(1, 0, 0, 0, "Shutting down without saving sessions\n");
-       for (i = 1; i < MAXSESSION; i++)
-       {
-               if (session[i].opened)
-                       sessionkill(i, "L2TPNS Closing");
-       }
-       for (i = 1; i < MAXTUNNEL; i++)
-       {
-               if (tunnel[i].ip || tunnel[i].state)
-                       tunnelshutdown(i, "L2TPNS Closing");
-       }
-
-       main_quit++;
-}
-
-static void sigchild_handler(int sig)
-{
-       while (waitpid(-1, NULL, WNOHANG) > 0)
-           ;
-}
-
-static void read_state()
-{
-       struct stat sb;
-       int i;
-       ippoolt itmp;
-       FILE *f;
-       char magic[sizeof(DUMP_MAGIC) - 1];
-       u32 buf[2];
-
-       if (!config->save_state)
-       {
-               unlink(STATEFILE);
-               return ;
-       }
-
-       if (stat(STATEFILE, &sb) < 0)
-       {
-               unlink(STATEFILE);
-               return ;
-       }
+       LOG(1, 0, 0, "Shutting down without saving sessions\n");
 
-       if (sb.st_mtime < (time(NULL) - 60))
-       {
-               LOG(0, 0, 0, 0, "State file is too old to read, ignoring\n");
-               unlink(STATEFILE);
-               return ;
-       }
-
-       f = fopen(STATEFILE, "r");
-       unlink(STATEFILE);
-
-       if (!f)
-       {
-               LOG(0, 0, 0, 0, "Can't read state file: %s\n", strerror(errno));
-               exit(1);
-       }
-
-       if (fread(magic, sizeof(magic), 1, f) != 1 || strncmp(magic, DUMP_MAGIC, sizeof(magic)))
-       {
-               LOG(0, 0, 0, 0, "Bad state file magic\n");
-               exit(1);
-       }
-
-       LOG(1, 0, 0, 0, "Reading state information\n");
-       if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] > MAXIPPOOL || buf[1] != sizeof(ippoolt))
-       {
-               LOG(0, 0, 0, 0, "Error/mismatch reading ip pool header from state file\n");
-               exit(1);
-       }
-
-       if (buf[0] > ip_pool_size)
-       {
-               LOG(0, 0, 0, 0, "ip pool has shrunk!  state = %d, current = %d\n", buf[0], ip_pool_size);
-               exit(1);
-       }
-
-       LOG(2, 0, 0, 0, "Loading %u ip addresses\n", buf[0]);
-       for (i = 0; i < buf[0]; i++)
+       if (config->cluster_iam_master)
        {
-               if (fread(&itmp, sizeof(itmp), 1, f) != 1)
-               {
-                       LOG(0, 0, 0, 0, "Error reading ip %d from state file: %s\n", i, strerror(errno));
-                       exit(1);
-               }
-
-               if (itmp.address != ip_address_pool[i].address)
+               for (i = 1; i < MAXSESSION; i++)
                {
-                       LOG(0, 0, 0, 0, "Mismatched ip %d from state file: pool may only be extended\n", i);
-                       exit(1);
+                       if (session[i].opened)
+                               sessionkill(i, "L2TPNS Closing");
                }
-
-               memcpy(&ip_address_pool[i], &itmp, sizeof(itmp));
-       }
-
-       if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXTUNNEL || buf[1] != sizeof(tunnelt))
-       {
-               LOG(0, 0, 0, 0, "Error/mismatch reading tunnel header from state file\n");
-               exit(1);
-       }
-
-       LOG(2, 0, 0, 0, "Loading %u tunnels\n", MAXTUNNEL);
-       if (fread(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
-       {
-               LOG(0, 0, 0, 0, "Error reading tunnel data from state file\n");
-               exit(1);
-       }
-
-       for (i = 0; i < MAXTUNNEL; i++)
-       {
-               tunnel[i].controlc = 0;
-               tunnel[i].controls = NULL;
-               tunnel[i].controle = NULL;
-               if (*tunnel[i].hostname)
-                       LOG(3, 0, 0, 0, "Created tunnel for %s\n", tunnel[i].hostname);
-       }
-
-       if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXSESSION || buf[1] != sizeof(sessiont))
-       {
-               LOG(0, 0, 0, 0, "Error/mismatch reading session header from state file\n");
-               exit(1);
-       }
-
-       LOG(2, 0, 0, 0, "Loading %u sessions\n", MAXSESSION);
-       if (fread(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
-       {
-               LOG(0, 0, 0, 0, "Error reading session data from state file\n");
-               exit(1);
-       }
-
-       for (i = 0; i < MAXSESSION; i++)
-       {
-               session[i].tbf_in = 0;
-               session[i].tbf_out = 0;
-               if (session[i].opened)
+               for (i = 1; i < MAXTUNNEL; i++)
                {
-                       LOG(2, 0, i, 0, "Loaded active session for user %s\n", session[i].user);
-                       if (session[i].ip)
-                               sessionsetup(session[i].tunnel, i);
+                       if (tunnel[i].ip || tunnel[i].state)
+                               tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
                }
        }
 
-       fclose(f);
-       LOG(0, 0, 0, 0, "Loaded saved state information\n");
+       main_quit++;
 }
 
-static void dump_state()
+static void sigchild_handler(int sig)
 {
-       FILE *f;
-       u32 buf[2];
-
-       if (!config->save_state)
-               return;
-
-       do
-       {
-               if (!(f = fopen(STATEFILE, "w")))
-                       break;
-
-               LOG(1, 0, 0, 0, "Dumping state information\n");
-
-               if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC) - 1, 1, f) != 1)
-                       break;
-
-               LOG(2, 0, 0, 0, "Dumping %u ip addresses\n", ip_pool_size);
-               buf[0] = ip_pool_size;
-               buf[1] = sizeof(ippoolt);
-               if (fwrite(buf, sizeof(buf), 1, f) != 1)
-                       break;
-               if (fwrite(ip_address_pool, sizeof(ippoolt), ip_pool_size, f) != ip_pool_size)
-                       break;
-
-               LOG(2, 0, 0, 0, "Dumping %u tunnels\n", MAXTUNNEL);
-               buf[0] = MAXTUNNEL;
-               buf[1] = sizeof(tunnelt);
-               if (fwrite(buf, sizeof(buf), 1, f) != 1)
-                       break;
-               if (fwrite(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
-                       break;
-
-               LOG(2, 0, 0, 0, "Dumping %u sessions\n", MAXSESSION);
-               buf[0] = MAXSESSION;
-               buf[1] = sizeof(sessiont);
-               if (fwrite(buf, sizeof(buf), 1, f) != 1)
-                       break;
-               if (fwrite(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
-                       break;
-
-               if (fclose(f) == 0)
-                       return ; // OK
-       }
-       while (0);
-
-       LOG(0, 0, 0, 0, "Can't write state information: %s\n", strerror(errno));
-       unlink(STATEFILE);
+       while (waitpid(-1, NULL, WNOHANG) > 0)
+           ;
 }
 
-static void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response)
+static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
 {
        MD5_CTX ctx;
        *challenge_response = NULL;
 
        if (!*config->l2tpsecret)
        {
-               LOG(0, 0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
+               LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
                return;
        }
 
-       LOG(4, 0, 0, 0, "   Building challenge response for CHAP request\n");
+       LOG(4, 0, 0, "   Building challenge response for CHAP request\n");
 
        *challenge_response = (char *)calloc(17, 1);
 
@@ -3377,6 +3937,7 @@ static int facility_value(char *name)
 static void update_config()
 {
        int i;
+       char *p;
        static int timeout = 0;
        static int interval = 0;
 
@@ -3385,9 +3946,12 @@ static void update_config()
        syslog_log = 0;
        if (log_stream)
        {
-               fclose(log_stream);
+               if (log_stream != stderr)
+                       fclose(log_stream);
+
                log_stream = NULL;
        }
+
        if (*config->log_filename)
        {
                if (strstr(config->log_filename, "syslog:") == config->log_filename)
@@ -3419,7 +3983,6 @@ static void update_config()
                setbuf(log_stream, NULL);
        }
 
-
        // Update radius
        config->numradiusservers = 0;
        for (i = 0; i < MAXRADSERVER; i++)
@@ -3433,18 +3996,71 @@ static void update_config()
                        // test twice, In case someone works with
                        // a secondary radius server without defining
                        // a primary one, this will work even then.
-                       if (i>0 && !config->radiusport[i])
+                       if (i > 0 && !config->radiusport[i])
                                config->radiusport[i] = config->radiusport[i-1];
                        if (!config->radiusport[i])
                                config->radiusport[i] = RADPORT;
                }
 
        if (!config->numradiusservers)
+               LOG(0, 0, 0, "No RADIUS servers defined!\n");
+
+       config->num_radfds = 1 << RADIUS_SHIFT;
+
+       // parse radius_authtypes_s
+       config->radius_authtypes = config->radius_authprefer = 0;
+       p = config->radius_authtypes_s;
+       while (p && *p)
+       {
+               char *s = strpbrk(p, " \t,");
+               int type = 0;
+
+               if (s)
+               {
+                       *s++ = 0;
+                       while (*s == ' ' || *s == '\t')
+                               s++;
+
+                       if (!*s)
+                               s = 0;
+               }
+
+               if (!strncasecmp("chap", p, strlen(p)))
+                       type = AUTHCHAP;
+               else if (!strncasecmp("pap", p, strlen(p)))
+                       type = AUTHPAP;
+               else
+                       LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
+
+               config->radius_authtypes |= type;
+               if (!config->radius_authprefer)
+                       config->radius_authprefer = type;
+
+               p = s;
+       }
+
+       if (!config->radius_authtypes)
+       {
+               LOG(0, 0, 0, "Defaulting to PAP authentication\n");
+               config->radius_authtypes = config->radius_authprefer = AUTHPAP;
+       }
+
+       // normalise radius_authtypes_s
+       if (config->radius_authprefer == AUTHPAP)
+       {
+               strcpy(config->radius_authtypes_s, "pap");
+               if (config->radius_authtypes & AUTHCHAP)
+                       strcat(config->radius_authtypes_s, ", chap");
+       }
+       else
        {
-               LOG(0, 0, 0, 0, "No RADIUS servers defined!\n");
+               strcpy(config->radius_authtypes_s, "chap");
+               if (config->radius_authtypes & AUTHPAP)
+                       strcat(config->radius_authtypes_s, ", pap");
        }
 
-       config->num_radfds = 2 << RADIUS_SHIFT;
+       // re-initialise the random number source
+       initrandom(config->random_device);
 
        // Update plugins
        for (i = 0; i < MAXPLUGINS; i++)
@@ -3463,6 +4079,7 @@ static void update_config()
                        remove_plugin(config->old_plugins[i]);
                }
        }
+
        memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
        if (!config->cleanup_interval) config->cleanup_interval = 10;
        if (!config->multi_read_count) config->multi_read_count = 10;
@@ -3484,7 +4101,7 @@ static void update_config()
 
                if (config->cluster_hb_timeout < t)
                {
-                       LOG(0,0,0,0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
+                       LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
                        config->cluster_hb_timeout = t;
                }
 
@@ -3508,7 +4125,7 @@ static void update_config()
                }
                else
                {
-                       LOG(0, 0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
+                       LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
                }
        }
 
@@ -3526,9 +4143,9 @@ static void read_config_file()
                return;
        }
 
-       LOG(3, 0, 0, 0, "Reading config file %s\n", config->config_file);
+       LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
        cli_do_file(f);
-       LOG(3, 0, 0, 0, "Done reading config file\n");
+       LOG(3, 0, 0, "Done reading config file\n");
        fclose(f);
        update_config();
 }
@@ -3536,26 +4153,26 @@ static void read_config_file()
 int sessionsetup(tunnelidt t, sessionidt s)
 {
        // A session now exists, set it up
-       ipt ip;
+       in_addr_t ip;
        char *user;
        sessionidt i;
        int r;
 
-       CSTAT(call_sessionsetup);
+       CSTAT(sessionsetup);
 
-       LOG(3, session[s].ip, s, t, "Doing session setup for session\n");
+       LOG(3, s, t, "Doing session setup for session\n");
 
-       if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
+       if (!session[s].ip)
        {
                assign_ip_address(s);
                if (!session[s].ip)
                {
-                       LOG(0, 0, s, t, "   No IP allocated. The IP address pool is FULL!\n");
-                       sessionshutdown(s, "No IP addresses available");
+                       LOG(0, s, t, "   No IP allocated.  The IP address pool is FULL!\n");
+                       sessionshutdown(s, "No IP addresses available.", 2, 7);
                        return 0;
                }
-               LOG(3, 0, s, t, "   No IP allocated. Assigned %s from pool\n",
-                       inet_toa(htonl(session[s].ip)));
+               LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
+                       fmtaddr(htonl(session[s].ip), 0));
        }
 
 
@@ -3577,23 +4194,36 @@ int sessionsetup(tunnelidt t, sessionidt s)
                }
        }
 
+       {
+               int routed = 0;
+
                // Add the route for this session.
-               //
-               // Static IPs need to be routed. Anything else
-               // is part of the IP address pool and is already routed,
-               // it just needs to be added to the IP cache.
-       if (session[s].ip_pool_index == -1) // static ip
-               routeset(s, session[s].ip, 0, 0, 1);
-       else
-               cache_ipmap(session[s].ip, s);
+               for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
+               {
+                       if ((session[s].ip & session[s].route[r].mask) ==
+                           (session[s].route[r].ip & session[s].route[r].mask))
+                               routed++;
+
+                       routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
+               }
 
-       for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
-               routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
+               // Static IPs need to be routed if not already
+               // convered by a Framed-Route.  Anything else is part
+               // of the IP address pool and is already routed, it
+               // just needs to be added to the IP cache.
+               // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
+               if (session[s].ip_pool_index == -1) // static ip
+               {
+                       if (!routed) routeset(s, session[s].ip, 0, 0, 1);
+               }
+               else
+                       cache_ipmap(session[s].ip, s);
+       }
 
        if (!session[s].unique_id)
        {
                // did this session just finish radius?
-               LOG(3, session[s].ip, s, t, "Sending initial IPCP to client\n");
+               LOG(3, s, t, "Sending initial IPCP to client\n");
                sendipcp(t, s);
                session[s].unique_id = ++last_id;
        }
@@ -3610,15 +4240,9 @@ int sessionsetup(tunnelidt t, sessionidt s)
 
        session[s].last_packet = time_now;
 
-       {
-               char *sessionip, *tunnelip;
-               sessionip = strdup(inet_toa(htonl(session[s].ip)));
-               tunnelip = strdup(inet_toa(htonl(tunnel[t].ip)));
-               LOG(2, session[s].ip, s, t, "Login by %s at %s from %s (%s)\n",
-                               session[s].user, sessionip, tunnelip, tunnel[t].hostname);
-               if (sessionip) free(sessionip);
-               if (tunnelip) free(tunnelip);
-       }
+       LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
+               fmtaddr(htonl(session[s].ip), 0),
+               fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
 
        cluster_send_session(s);        // Mark it as dirty, and needing to the flooded to the cluster.
 
@@ -3632,12 +4256,13 @@ int sessionsetup(tunnelidt t, sessionidt s)
 int load_session(sessionidt s, sessiont *new)
 {
        int i;
+       int newip = 0;
 
                // Sanity checks.
        if (new->ip_pool_index >= MAXIPPOOL ||
                new->tunnel >= MAXTUNNEL)
        {
-               LOG(0,0,s,0, "Strange session update received!\n");
+               LOG(0, s, 0, "Strange session update received!\n");
                        // FIXME! What to do here?
                return 0;
        }
@@ -3649,54 +4274,101 @@ int load_session(sessionidt s, sessiont *new)
 
        session[s].tunnel = new->tunnel; // For logging in cache_ipmap
 
+       // See if routes/ip cache need updating
+       if (new->ip != session[s].ip)
+               newip++;
+
+       for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
+               if (new->route[i].ip != session[s].route[i].ip ||
+                   new->route[i].mask != session[s].route[i].mask)
+                       newip++;
 
-       if (new->ip != session[s].ip)   // Changed ip. fix up hash tables.
+       // needs update
+       if (newip)
        {
-               if (session[s].ip)      // If there's an old one, remove it.
+               int routed = 0;
+
+               // remove old routes...
+               for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
                {
-                       // Remove any routes if the IP has changed
-                       for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
-                       {
-                               routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
-                               session[s].route[i].ip = 0;
-                       }
+                       if ((session[s].ip & session[s].route[i].mask) ==
+                           (session[s].route[i].ip & session[s].route[i].mask))
+                               routed++;
+
+                       routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
+               }
 
+               // ...ip
+               if (session[s].ip)
+               {
                        if (session[s].ip_pool_index == -1) // static IP
-                               routeset(s, session[s].ip, 0, 0, 0);
+                       {
+                               if (!routed) routeset(s, session[s].ip, 0, 0, 0);
+                       }
                        else            // It's part of the IP pool, remove it manually.
                                uncache_ipmap(session[s].ip);
                }
 
+               routed = 0;
+
+               // add new routes...
+               for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
+               {
+                       if ((new->ip & new->route[i].mask) ==
+                           (new->route[i].ip & new->route[i].mask))
+                               routed++;
+
+                       routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
+               }
+
+               // ...ip
                if (new->ip)
                {
                        // If there's a new one, add it.
                        if (new->ip_pool_index == -1)
-                               routeset(s, new->ip, 0, 0, 1);
+                       {
+                               if (!routed) routeset(s, new->ip, 0, 0, 1);
+                       }
                        else
                                cache_ipmap(new->ip, s);
                }
        }
 
-       // Update routed networks
-       for (i = 0; i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
+       // check v6 routing
+       if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
+                   route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
+
+       // check filters
+       if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
        {
-               if (new->route[i].ip == session[s].route[i].ip &&
-                   new->route[i].mask == session[s].route[i].mask)
-                       continue;
+               LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
+               new->filter_in = 0;
+       }
 
-               if (session[s].route[i].ip) // Remove the old one if it exists.
-                       routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
+       if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
+       {
+               LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
+               new->filter_out = 0;
+       }
 
-               if (new->route[i].ip)   // Add the new one if it exists.
-                       routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
+       if (new->filter_in != session[s].filter_in)
+       {
+               if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
+               if (new->filter_in)       ip_filters[new->filter_in - 1].used++;
+       }
+
+       if (new->filter_out != session[s].filter_out)
+       {
+               if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
+               if (new->filter_out)       ip_filters[new->filter_out - 1].used++;
        }
 
        if (new->tunnel && s > config->cluster_highest_sessionid)       // Maintain this in the slave. It's used
                                        // for walking the sessions to forward byte counts to the master.
                config->cluster_highest_sessionid = s;
 
-       // TEMP: old session struct used a u32 to define the throttle
-       // speed for both up/down, new uses a u16 for each.  Deal with
+       // TEMP: old session struct used a uint32_t to define the throttle
+       // speed for both up/down, new uses a uint16_t for each.  Deal with
        // sessions from an old master for migration.
        if (new->throttle_out == 0 && new->tbf_out)
                new->throttle_out = new->throttle_in;
@@ -3725,7 +4397,7 @@ static void *open_plugin(char *plugin_name, int load)
        char path[256] = "";
 
        snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
-       LOG(2, 0, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
+       LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
        return dlopen(path, RTLD_NOW);
 }
 
@@ -3741,30 +4413,33 @@ static void *getconfig(char *key, enum config_typet type)
                        if (config_values[i].type == type)
                                return ((void *) config) + config_values[i].offset;
 
-                       LOG(1, 0, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
+                       LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
                                key, type, config_values[i].type);
 
                        return 0;
                }
        }
 
-       LOG(1, 0, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
+       LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
        return 0;
 }
 
-static void add_plugin(char *plugin_name)
+static int add_plugin(char *plugin_name)
 {
        static struct pluginfuncs funcs = {
                _log,
                _log_hex,
-               inet_toa,
+               fmtaddr,
                sessionbyuser,
                sessiontbysessionidt,
                sessionidtbysessiont,
-               sessionkill,
                radiusnew,
                radiussend,
                getconfig,
+               sessionshutdown,
+               sessionkill,
+               throttle_session,
+               cluster_send_session,
        };
 
        void *p = open_plugin(plugin_name, 1);
@@ -3773,23 +4448,23 @@ static void add_plugin(char *plugin_name)
 
        if (!p)
        {
-               LOG(1, 0, 0, 0, "   Plugin load failed: %s\n", dlerror());
-               return;
+               LOG(1, 0, 0, "   Plugin load failed: %s\n", dlerror());
+               return -1;
        }
 
        if (ll_contains(loaded_plugins, p))
        {
                dlclose(p);
-               return;
+               return 0; // already loaded
        }
 
        {
-               int *v = dlsym(p, "__plugin_api_version");
+               int *v = dlsym(p, "plugin_api_version");
                if (!v || *v != PLUGIN_API_VERSION)
                {
-                       LOG(1, 0, 0, 0, "   Plugin load failed: API version mismatch: %s\n", dlerror());
+                       LOG(1, 0, 0, "   Plugin load failed: API version mismatch: %s\n", dlerror());
                        dlclose(p);
-                       return;
+                       return -1;
                }
        }
 
@@ -3797,9 +4472,9 @@ static void add_plugin(char *plugin_name)
        {
                if (!initfunc(&funcs))
                {
-                       LOG(1, 0, 0, 0, "   Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
+                       LOG(1, 0, 0, "   Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
                        dlclose(p);
-                       return;
+                       return -1;
                }
        }
 
@@ -3810,12 +4485,13 @@ static void add_plugin(char *plugin_name)
                void *x;
                if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
                {
-                       LOG(3, 0, 0, 0, "   Supports function \"%s\"\n", plugin_functions[i]);
+                       LOG(3, 0, 0, "   Supports function \"%s\"\n", plugin_functions[i]);
                        ll_push(plugins[i], x);
                }
        }
 
-       LOG(2, 0, 0, 0, "   Loaded plugin %s\n", plugin_name);
+       LOG(2, 0, 0, "   Loaded plugin %s\n", plugin_name);
+       return 1;
 }
 
 static void run_plugin_done(void *plugin)
@@ -3826,45 +4502,51 @@ static void run_plugin_done(void *plugin)
                donefunc();
 }
 
-static void remove_plugin(char *plugin_name)
+static int remove_plugin(char *plugin_name)
 {
        void *p = open_plugin(plugin_name, 0);
-       int i;
+       int loaded = 0;
 
        if (!p)
-               return;
-
-       for (i = 0; i < max_plugin_functions; i++)
-       {
-               void *x;
-               if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
-                       ll_delete(plugins[i], x);
-       }
+               return -1;
 
        if (ll_contains(loaded_plugins, p))
        {
+               int i;
+               for (i = 0; i < max_plugin_functions; i++)
+               {
+                       void *x;
+                       if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
+                               ll_delete(plugins[i], x);
+               }
+
                ll_delete(loaded_plugins, p);
                run_plugin_done(p);
+               loaded = 1;
        }
 
        dlclose(p);
-       LOG(2, 0, 0, 0, "Removed plugin %s\n", plugin_name);
+       LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
+       return loaded;
 }
 
 int run_plugins(int plugin_type, void *data)
 {
        int (*func)(void *data);
-       if (!plugins[plugin_type] || plugin_type > max_plugin_functions) return 1;
+
+       if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
+               return PLUGIN_RET_ERROR;
 
        ll_reset(plugins[plugin_type]);
        while ((func = ll_next(plugins[plugin_type])))
        {
-               int rc;
-               rc = func(data);
-               if (rc == PLUGIN_RET_STOP) return 1;
-               if (rc == PLUGIN_RET_ERROR) return 0;
+               int r = func(data);
+
+               if (r != PLUGIN_RET_OK)
+                       return r; // stop here
        }
-       return 1;
+
+       return PLUGIN_RET_OK;
 }
 
 static void plugins_done()
@@ -3876,39 +4558,176 @@ static void plugins_done()
                run_plugin_done(p);
 }
 
-static void processcontrol(u8 * buf, int len, struct sockaddr_in *addr)
+static void processcontrol(uint8_t * buf, int len, struct sockaddr_in *addr, int alen)
 {
-       char *resp;
-       int l;
-       struct param_control param = { buf, len, ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port), NULL, 0, 0 };
-
+       struct nsctl request;
+       struct nsctl response;
+       int type = unpack_control(&request, buf, len);
+       int r;
+       void *p;
 
        if (log_stream && config->debug >= 4)
        {
-               LOG(4, ntohl(addr->sin_addr.s_addr), 0, 0, "Received ");
-               dump_packet(buf, log_stream);
+               if (type < 0)
+               {
+                       LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
+                               fmtaddr(addr->sin_addr.s_addr, 0), type);
+               }
+               else
+               {
+                       LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
+                       dump_control(&request, log_stream);
+               }
        }
 
-       resp = calloc(1400, 1);
-       l = new_packet(PKT_RESP_ERROR, resp);
-       *(int *)(resp + 6) = *(int *)(buf + 6);
+       switch (type)
+       {
+       case NSCTL_REQ_LOAD:
+               if (request.argc != 1)
+               {
+                       response.type = NSCTL_RES_ERR;
+                       response.argc = 1;
+                       response.argv[0] = "name of plugin required";
+               }
+               else if ((r = add_plugin(request.argv[0])) < 1)
+               {
+                       response.type = NSCTL_RES_ERR;
+                       response.argc = 1;
+                       response.argv[0] = !r
+                               ? "plugin already loaded"
+                               : "error loading plugin";
+               }
+               else
+               {
+                       response.type = NSCTL_RES_OK;
+                       response.argc = 0;
+               }
+
+               break;
+
+       case NSCTL_REQ_UNLOAD:
+               if (request.argc != 1)
+               {
+                       response.type = NSCTL_RES_ERR;
+                       response.argc = 1;
+                       response.argv[0] = "name of plugin required";
+               }
+               else if ((r = remove_plugin(request.argv[0])) < 1)
+               {
+                       response.type = NSCTL_RES_ERR;
+                       response.argc = 1;
+                       response.argv[0] = !r
+                               ? "plugin not loaded"
+                               : "plugin not found";
+               }
+               else
+               {
+                       response.type = NSCTL_RES_OK;
+                       response.argc = 0;
+               }
+
+               break;
+
+       case NSCTL_REQ_HELP:
+               response.type = NSCTL_RES_OK;
+               response.argc = 0;
+
+               ll_reset(loaded_plugins);
+               while ((p = ll_next(loaded_plugins)))
+               {
+                       char **help = dlsym(p, "plugin_control_help");
+                       while (response.argc < 0xff && help && *help)
+                               response.argv[response.argc++] = *help++;
+               }
+
+               break;
+
+       case NSCTL_REQ_CONTROL:
+               {
+                       struct param_control param = {
+                               config->cluster_iam_master,
+                               request.argc,
+                               request.argv,
+                               0,
+                               NULL,
+                       };
+
+                       int r = run_plugins(PLUGIN_CONTROL, &param);
+
+                       if (r == PLUGIN_RET_ERROR)
+                       {
+                               response.type = NSCTL_RES_ERR;
+                               response.argc = 1;
+                               response.argv[0] = param.additional
+                                       ? param.additional
+                                       : "error returned by plugin";
+                       }
+                       else if (r == PLUGIN_RET_NOTMASTER)
+                       {
+                               static char msg[] = "must be run on master: 000.000.000.000";
+
+                               response.type = NSCTL_RES_ERR;
+                               response.argc = 1;
+                               if (config->cluster_master_address)
+                               {
+                                       strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
+                                       response.argv[0] = msg;
+                               }
+                               else
+                               {
+                                       response.argv[0] = "must be run on master: none elected";
+                               }
+                       }
+                       else if (!(param.response & NSCTL_RESPONSE))
+                       {
+                               response.type = NSCTL_RES_ERR;
+                               response.argc = 1;
+                               response.argv[0] = param.response
+                                       ? "unrecognised response value from plugin"
+                                       : "unhandled action";
+                       }
+                       else
+                       {
+                               response.type = param.response;
+                               response.argc = 0;
+                               if (param.additional)
+                               {
+                                       response.argc = 1;
+                                       response.argv[0] = param.additional;
+                               }
+                       }
+               }
+
+               break;
 
-       param.type = ntohs(*(short *)(buf + 2));
-       param.id = ntohl(*(int *)(buf + 6));
-       param.data_length = ntohs(*(short *)(buf + 4)) - 10;
-       param.data = (param.data_length > 0) ? (char *)(buf + 10) : NULL;
-       param.response = resp;
-       param.response_length = l;
+       default:
+               response.type = NSCTL_RES_ERR;
+               response.argc = 1;
+               response.argv[0] = "error unpacking control packet";
+       }
 
-       run_plugins(PLUGIN_CONTROL, &param);
+       buf = calloc(NSCTL_MAX_PKT_SZ, 1);
+       if (!buf)
+       {
+               LOG(2, 0, 0, "Failed to allocate nsctl response\n");
+               return;
+       }
 
-       if (param.send_response)
+       r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
+       if (r > 0)
        {
-               send_packet(controlfd, ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port), param.response, param.response_length);
-               LOG(4, ntohl(addr->sin_addr.s_addr), 0, 0, "Sent Control packet response\n");
+               sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
+               if (log_stream && config->debug >= 4)
+               {
+                       LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
+                       dump_control(&response, log_stream);
+               }
        }
+       else
+               LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
+                       fmtaddr(addr->sin_addr.s_addr, 0), r);
 
-       free(resp);
+       free(buf);
 }
 
 static tunnelidt new_tunnel()
@@ -3918,13 +4737,13 @@ static tunnelidt new_tunnel()
        {
                if (tunnel[i].state == TUNNELFREE)
                {
-                       LOG(4, 0, 0, i, "Assigning tunnel ID %d\n", i);
+                       LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
                        if (i > config->cluster_highest_tunnelid)
                                config->cluster_highest_tunnelid = i;
                        return i;
                }
        }
-       LOG(0, 0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
+       LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
        return 0;
 }
 
@@ -3947,7 +4766,7 @@ void become_master(void)
        {
                for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                {
-                       if (!session[s].tunnel) // Not an in-use session.
+                       if (!session[s].opened) // Not an in-use session.
                                continue;
 
                        run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
@@ -3979,7 +4798,7 @@ int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc
        for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
        {
                int idle;
-               if (!session[s].tunnel)
+               if (!session[s].opened)
                        continue;
 
                idle = time_now - session[s].last_packet;
@@ -4017,7 +4836,7 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc
        for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
        {
                int open = 0, d;
-               if (!session[s].tunnel)
+               if (!session[s].opened)
                        continue;
 
                d = time_now - session[s].opened;
@@ -4044,74 +4863,159 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc
 
 /* Unhide an avp.
  *
- * This unencodes the AVP using the L2TP CHAP secret and the
- * previously stored random vector. It replaces the hidden data with
- * the cleartext data and returns the length of the cleartext data
- * (including the AVP "header" of 6 bytes).
- *
- * Based on code from rp-l2tpd by Roaring Penguin Software Inc.
+ * This unencodes the AVP using the L2TP secret and the previously
+ * stored random vector.  It overwrites the hidden data with the
+ * unhidden AVP subformat.
  */
-static int unhide_avp(u8 *avp, tunnelidt t, sessionidt s, u16 length)
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
 {
        MD5_CTX ctx;
-       u8 *cursor;
-       u8 digest[16];
-       u8 working_vector[16];
-       uint16_t hidden_length;
-       u8 type[2];
-       size_t done, todo;
-       u8 *output;
-
-       // Find the AVP type.
-       type[0] = *(avp + 4);
-       type[1] = *(avp + 5);
-
-       // Line up with the hidden data
-       cursor = output = avp + 6;
+       uint8_t digest[16];
+       uint8_t *last;
+       size_t d = 0;
 
        // Compute initial pad
        MD5Init(&ctx);
-       MD5Update(&ctx, type, 2);
+       MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
+       MD5Update(&ctx, (uint8_t)  type       & 0xff, 1);
        MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-       MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length);
+       MD5Update(&ctx, vector, vec_len);
        MD5Final(digest, &ctx);
 
-       // Get hidden length
-       hidden_length = ((uint16_t) (digest[0] ^ cursor[0])) * 256 + (uint16_t) (digest[1] ^ cursor[1]);
+       // pointer to last decoded 16 octets
+       last = value;
+
+       while (len > 0)
+       {
+               // calculate a new pad based on the last decoded block
+               if (d >= sizeof(digest))
+               {
+                       MD5Init(&ctx);
+                       MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+                       MD5Update(&ctx, last, sizeof(digest));
+                       MD5Final(digest, &ctx);
+
+                       d = 0;
+                       last = value;
+               }
+
+               *value++ ^= digest[d++];
+               len--;
+       }
+}
+
+static int ip_filter_port(ip_filter_portt *p, uint16_t port)
+{
+       switch (p->op)
+       {
+       case FILTER_PORT_OP_EQ:    return port == p->port;
+       case FILTER_PORT_OP_NEQ:   return port != p->port;
+       case FILTER_PORT_OP_GT:    return port > p->port;
+       case FILTER_PORT_OP_LT:    return port < p->port;
+       case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
+       }
 
-       // Keep these for later use
-       working_vector[0] = *cursor;
-       working_vector[1] = *(cursor + 1);
-       cursor += 2;
+       return 0;
+}
 
-       if (hidden_length > length - 8)
+static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
+{
+       switch (op)
        {
-               LOG(1, 0, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length);
+       case FILTER_FLAG_OP_ANY:
+               return (flags & sflags) || (~flags & cflags);
+
+       case FILTER_FLAG_OP_ALL:
+               return (flags & sflags) == sflags && (~flags & cflags) == cflags;
+
+       case FILTER_FLAG_OP_EST:
+               return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
+       }
+
+       return 0;
+}
+
+int ip_filter(uint8_t *buf, int len, uint8_t filter)
+{
+       uint16_t frag_offset;
+       uint8_t proto;
+       in_addr_t src_ip;
+       in_addr_t dst_ip;
+       uint16_t src_port = 0;
+       uint16_t dst_port = 0;
+       uint8_t flags = 0;
+       ip_filter_rulet *rule;
+
+       if (len < 20) // up to end of destination address
+               return 0;
+
+       if ((*buf >> 4) != 4) // IPv4
                return 0;
+
+       frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
+       proto = buf[9];
+       src_ip = *(in_addr_t *) (buf + 12);
+       dst_ip = *(in_addr_t *) (buf + 16);
+
+       if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
+       {
+               int l = (buf[0] & 0xf) * 4; // length of IP header
+               if (len < l + 4) // ports
+                       return 0;
+
+               src_port = ntohs(*(uint16_t *) (buf + l));
+               dst_port = ntohs(*(uint16_t *) (buf + l + 2));
+               if (proto == IPPROTO_TCP)
+               {
+                       if (len < l + 14) // flags
+                               return 0;
+
+                       flags = buf[l + 13] & 0x3f;
+               }
        }
 
-       /* Decrypt remainder */
-       done = 2;
-       todo = hidden_length;
-       while (todo)
+       for (rule = ip_filters[filter].rules; rule->action; rule++)
        {
-               working_vector[done] = *cursor;
-               *output = digest[done] ^ *cursor;
-               ++output;
-               ++cursor;
-               --todo;
-               ++done;
-               if (done == 16 && todo)
+               if (rule->proto != IPPROTO_IP && proto != rule->proto)
+                       continue;
+
+               if (rule->src_wild != INADDR_BROADCAST &&
+                   (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
+                       continue;
+
+               if (rule->dst_wild != INADDR_BROADCAST &&
+                   (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
+                       continue;
+
+               if (frag_offset)
                {
-                       // Compute new digest
-                       done = 0;
-                       MD5Init(&ctx);
-                       MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-                       MD5Update(&ctx, &working_vector, 16);
-                       MD5Final(digest, &ctx);
+                       if (!rule->frag || rule->action == FILTER_ACTION_DENY)
+                               continue;
+               }
+               else
+               {
+                       if (rule->frag)
+                               continue;
+
+                       if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
+                       {
+                               if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
+                                       continue;
+
+                               if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
+                                       continue;
+
+                               if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
+                                   !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
+                                       continue;
+                       }
                }
+
+               // matched
+               rule->counter++;
+               return rule->action == FILTER_ACTION_PERMIT;
        }
 
-       return hidden_length + 6;
+       // default deny
+       return 0;
 }
-