reset .die on master takeover
[l2tpns.git] / l2tpns.c
index f2537a4..10ab3a5 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -4,7 +4,7 @@
 // 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 1.75 2005/01/07 07:18:33 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.89 2005/04/01 06:39:00 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -19,6 +19,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.75 2005/01/07 07:18:33 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>
@@ -62,9 +63,11 @@ 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 int tunidx;             // ifr_ifindex of tun device
 static uint32_t sessionid = 0; // session id for radius accounting
 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).
@@ -75,6 +78,10 @@ struct cli_session_actions *cli_session_actions = NULL;      // Pending session chang
 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 uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
@@ -99,7 +106,6 @@ config_descriptt config_values[] = {
        CONFIG("l2tp_secret", l2tpsecret, STRING),
        CONFIG("primary_dns", default_dns1, IPv4),
        CONFIG("secondary_dns", default_dns2, IPv4),
-       CONFIG("save_state", save_state, BOOL),
        CONFIG("primary_radius", radiusserver[0], IPv4),
        CONFIG("secondary_radius", radiusserver[1], IPv4),
        CONFIG("primary_radius_port", radiusport[0], SHORT),
@@ -120,10 +126,12 @@ config_descriptt config_values[] = {
        CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
        CONFIG("lock_pages", lock_pages, BOOL),
        CONFIG("icmp_rate", icmp_rate, INT),
+       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 },
 };
 
@@ -150,7 +158,7 @@ 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.
@@ -162,6 +170,7 @@ struct Tringbuffer *ringbuffer = NULL;
 
 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(int all);
 static void sighup_handler(int sig);
@@ -169,8 +178,6 @@ 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, uint8_t id, uint16_t challenge_length, char **challenge_response);
 static void update_config(void);
 static void read_config_file(void);
@@ -180,7 +187,7 @@ static int remove_plugin(char *plugin_name);
 static void plugins_done(void);
 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
 static tunnelidt new_tunnel(void);
-static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t 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)
@@ -420,11 +427,61 @@ static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, i
        }
 }
 
+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;
@@ -470,6 +527,42 @@ static void inittun(void)
                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
@@ -536,17 +629,62 @@ static int lookup_ipmap(in_addr_t ip)
        return (int) (intptr_t) d[(size_t) *a];
 }
 
+static int lookup_ipv6map(struct in6_addr ip)
+{
+       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++;
+       }
+
+       LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
+                       inet_ntop(AF_INET6, &ip, ipv6addr,
+                               INET6_ADDRSTRLEN),
+                       s);
+
+       return s;
+}
+
 sessionidt sessionbyip(in_addr_t ip)
 {
        int s = lookup_ipmap(ip);
        CSTAT(sessionbyip);
 
-       if (s > 0 && s < MAXSESSION && session[s].tunnel)
+       if (s > 0 && s < MAXSESSION && session[s].opened)
                return (sessionidt) s;
 
        return 0;
 }
 
+sessionidt sessionbyipv6(struct in6_addr ip)
+{
+       int s;
+       CSTAT(sessionbyipv6);
+
+       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;
+}
+
 //
 // Take an IP address in HOST byte order and
 // add it to the sessionid by IP cache.
@@ -586,6 +724,42 @@ 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.
 //
@@ -641,8 +815,11 @@ sessionidt sessionbyuser(char *username)
        int s;
        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.
 
@@ -684,17 +861,16 @@ void send_garp(in_addr_t 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;
 }
 
@@ -774,7 +950,7 @@ static void processipout(uint8_t * buf, int len)
        tunnelidt t;
        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;
 
        uint8_t b[MAXETHER + 20];
@@ -784,13 +960,13 @@ static void processipout(uint8_t * buf, int len)
        if (len < MIN_IP_SIZE)
        {
                LOG(1, 0, 0, "Short IP, %d bytes\n", len);
-               STAT(tunnel_tx_errors);
+               STAT(tun_rx_errors);
                return;
        }
        if (len >= MAXETHER)
        {
                LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
-               STAT(tunnel_tx_errors);
+               STAT(tun_rx_errors);
                return;
        }
 
@@ -828,6 +1004,45 @@ static void processipout(uint8_t * buf, int len)
        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;
@@ -865,7 +1080,116 @@ static void processipout(uint8_t * 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..
+}
+
+// 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)
+               {
+                       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...
+       }
+
+       // 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..
 }
 
 //
@@ -915,7 +1239,7 @@ static void send_ipout(sessionidt s, uint8_t *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)
@@ -940,7 +1264,7 @@ static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
        c->length += 10;
 }
 
-// add an AVP (32 bit)
+// add an AVP (string)
 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
 {
        uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
@@ -1035,7 +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)
@@ -1071,9 +1395,9 @@ void throttle_session(sessionidt s, int rate_in, int rate_out)
 }
 
 // add/remove filters from session (-1 = no change)
-void filter_session(sessionidt s, int filter_in, int filter_out)
+static void filter_session(sessionidt s, int filter_in, int filter_out)
 {
-       if (!session[s].tunnel)
+       if (!session[s].opened)
                return; // No-one home.
 
        if (!*session[s].user)
@@ -1109,16 +1433,16 @@ void filter_session(sessionidt s, int filter_in, int 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(sessionshutdown);
 
-       if (!session[s].tunnel)
+       if (!session[s].opened)
        {
-               LOG(3, 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
        }
 
@@ -1129,7 +1453,7 @@ void sessionshutdown(sessionidt s, char *reason)
                run_plugins(PLUGIN_KILL_SESSION, &data);
        }
 
-       if (session[s].opened && !walled_garden && !session[s].die)
+       if (session[s].ip && !walled_garden && !session[s].die)
        {
                // RADIUS Stop message
                uint16_t r = session[s].radius;
@@ -1175,20 +1499,34 @@ void sessionshutdown(sessionidt s, char *reason)
                }
                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
        }
 
        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--;
@@ -1218,7 +1556,7 @@ 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 on IPCP", 3, 0);
                return;
        }
 
@@ -1236,16 +1574,49 @@ void sendipcp(tunnelidt t, sessionidt s)
 
        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
+       }
 }
 
 // kill a session now
-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)
 {
 
        CSTAT(sessionkill);
 
-       session[s].die = now();
-       sessionshutdown(s, reason);  // close radius/routes, etc.
+       if (!session[s].opened) // not alive
+               return;
+
+       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;
+       }
+
+       session[s].die = TIME;
+       sessionshutdown(s, reason, 3, 0);  // close radius/routes, etc.
        if (session[s].radius)
                radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
 
@@ -1286,19 +1657,19 @@ 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, t, "Kill tunnel %d: %s\n", t, reason);
-       cli_tunnel_actions[s].action = 0;
+       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;
 
@@ -1313,19 +1684,40 @@ static void tunnelshutdown(tunnelidt t, char *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
        }
 }
 
@@ -1400,7 +1792,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
        {                          // control
                uint16_t message = 0xFFFF;      // message type
                uint8_t fatal = 0;
-               uint8_t mandatorymessage = 0;
+               uint8_t mandatory = 0;
                uint8_t chap = 0;               // if CHAP being used
                uint16_t asession = 0;          // assigned session
                uint32_t amagic = 0;            // magic number
@@ -1416,7 +1808,10 @@ void processudp(uint8_t * 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, s, t, "Bad control header %02X\n", *buf);
                        STAT(tunnel_rx_errors);
@@ -1526,71 +1921,111 @@ void processudp(uint8_t * 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
                        {
                                uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
                                uint8_t *b = p;
                                uint8_t flags = *p;
                                uint16_t mtype;
-                               p += n;       // next
-                               if (l < n)
+                               if (n > l)
                                {
                                        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, 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, s, t, "Hidden AVP requested, but no random vector.\n");
                                                fatal = flags;
+                                               result = 2; // general error
+                                               error = 6; // generic
+                                               msg = "no random vector";
+                                               continue;
+                                       }
+                                       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, s, t, "Unrecognised AVP flags %02X\n", *b);
-                                       fatal = flags;
-                                       continue; // next
-                               }
-                               b += 2;
-                               if (*(uint16_t *) (b))
-                               {
-                                       LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
-                                       fatal = flags;
-                                       continue; // next
-                               }
-                               b += 2;
-                               mtype = ntohs(*(uint16_t *) (b));
-                               b += 2;
-                               n -= 6;
 
                                LOG(4, s, t, "   AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
                                switch (mtype)
                                {
                                case 0:     // message type
                                        message = ntohs(*(uint16_t *) b);
+                                       mandatory = flags & 0x80;
                                        LOG(4, s, t, "   Message type = %d (%s)\n", *b, l2tp_message_type(message));
-                                       mandatorymessage = flags;
                                        break;
                                case 1:     // result code
                                        {
@@ -1625,6 +2060,9 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                                {   // allow 0.0 and 1.0
                                                        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
                                                }
                                        }
@@ -1801,14 +2239,20 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        session[s].random_vector_length = n;
                                        break;
                                default:
-                                       LOG(2, 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)
                                {
@@ -1833,8 +2277,7 @@ void processudp(uint8_t * 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
@@ -1852,7 +2295,8 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        if (!sessionfree)
                                        {
                                                STAT(session_overflow);
-                                               tunnelshutdown(t, "No free sessions");
+                                               LOG(1, 0, t, "No free sessions");
+                                               return;
                                        }
                                        else
                                        {
@@ -1876,7 +2320,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 
                                                c = controlnew(11); // sending ICRP
                                                session[s].id = sessionid++;
-                                               session[s].opened = time(NULL);
+                                               session[s].opened = time_now;
                                                session[s].tunnel = t;
                                                session[s].far = asession;
                                                session[s].last_packet = time_now;
@@ -1907,15 +2351,15 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        break;
                                case 14:      // CDN
                                        controlnull(t); // ack
-                                       sessionshutdown(s, "Closed (Received CDN)");
+                                       sessionshutdown(s, "Closed (Received CDN)", 0, 0);
                                        break;
                                case 0xFFFF:
                                        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, s, t, "Unknown message type %d\n", message);
                                        break;
@@ -1956,7 +2400,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                        l -= 2;
                }
 
-               if (s && !session[s].tunnel)    // Is something wrong??
+               if (s && !session[s].opened)    // Is something wrong??
                {
                        if (!config->cluster_iam_master)
                        {
@@ -1966,9 +2410,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                        }
 
 
-                       LOG(1, 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;
                }
@@ -1997,6 +2439,19 @@ void processudp(uint8_t * 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;
@@ -2020,6 +2475,28 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 
                        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);
@@ -2048,6 +2525,10 @@ static void processtun(uint8_t * buf, int len)
 
        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.
 }
 
@@ -2123,7 +2604,7 @@ static int regular_cleanups(void)
                        if (a & CLI_TUN_KILL)
                        {
                                LOG(2, 0, t, "Dropping tunnel by CLI\n");
-                               tunnelshutdown(t, "Requested by administrator");
+                               tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
                        }
                }
 
@@ -2136,7 +2617,7 @@ 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))
@@ -2157,13 +2638,13 @@ static int regular_cleanups(void)
                // Drop sessions who have not responded within IDLE_TIMEOUT seconds
                if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
                {
-                       sessionshutdown(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))
                {
                        uint8_t b[MAXCONTROL] = {0};
@@ -2191,7 +2672,7 @@ static int regular_cleanups(void)
                        if (a & CLI_SESS_KILL)
                        {
                                LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
-                               sessionshutdown(s, "Requested by administrator");
+                               sessionshutdown(s, "Requested by administrator", 3, 0);
                                a = 0; // dead, no need to check for other actions
                        }
 
@@ -2691,9 +3172,9 @@ static void initdata(int optdebug, char *optconfig)
                exit(1);
        }
 
-       if (!(sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION)))
+       if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
        {
-               LOG(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);
        }
 
@@ -2745,7 +3226,7 @@ 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.
@@ -2754,7 +3235,7 @@ 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)
@@ -2880,8 +3361,9 @@ 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)
@@ -3245,8 +3727,6 @@ int main(int argc, char *argv[])
        initrad();
        initippool();
 
-       read_state();
-
        signal(SIGHUP, sighup_handler);
        signal(SIGTERM, sigterm_handler);
        signal(SIGINT, sigterm_handler);
@@ -3338,9 +3818,6 @@ static void sigalrm_handler(int sig)
 static void sigterm_handler(int sig)
 {
        LOG(1, 0, 0, "Shutting down cleanly\n");
-       if (config->save_state)
-               dump_state();
-
        main_quit++;
 }
 
@@ -3360,7 +3837,7 @@ static void sigquit_handler(int sig)
                for (i = 1; i < MAXTUNNEL; i++)
                {
                        if (tunnel[i].ip || tunnel[i].state)
-                               tunnelshutdown(i, "L2TPNS Closing");
+                               tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
                }
        }
 
@@ -3373,182 +3850,6 @@ static void sigchild_handler(int sig)
            ;
 }
 
-static void read_state()
-{
-       struct stat sb;
-       int i;
-       ippoolt itmp;
-       FILE *f;
-       char magic[sizeof(DUMP_MAGIC) - 1];
-       uint32_t buf[2];
-
-       if (!config->save_state)
-       {
-               unlink(STATEFILE);
-               return ;
-       }
-
-       if (stat(STATEFILE, &sb) < 0)
-       {
-               unlink(STATEFILE);
-               return ;
-       }
-
-       if (sb.st_mtime < (time(NULL) - 60))
-       {
-               LOG(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, "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, "Bad state file magic\n");
-               exit(1);
-       }
-
-       LOG(1, 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, "Error/mismatch reading ip pool header from state file\n");
-               exit(1);
-       }
-
-       if (buf[0] > ip_pool_size)
-       {
-               LOG(0, 0, 0, "ip pool has shrunk!  state = %d, current = %d\n", buf[0], ip_pool_size);
-               exit(1);
-       }
-
-       LOG(2, 0, 0, "Loading %u ip addresses\n", buf[0]);
-       for (i = 0; i < buf[0]; i++)
-       {
-               if (fread(&itmp, sizeof(itmp), 1, f) != 1)
-               {
-                       LOG(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)
-               {
-                       LOG(0, 0, 0, "Mismatched ip %d from state file: pool may only be extended\n", i);
-                       exit(1);
-               }
-
-               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, "Error/mismatch reading tunnel header from state file\n");
-               exit(1);
-       }
-
-       LOG(2, 0, 0, "Loading %u tunnels\n", MAXTUNNEL);
-       if (fread(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
-       {
-               LOG(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, "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, "Error/mismatch reading session header from state file\n");
-               exit(1);
-       }
-
-       LOG(2, 0, 0, "Loading %u sessions\n", MAXSESSION);
-       if (fread(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
-       {
-               LOG(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)
-               {
-                       LOG(2, i, 0, "Loaded active session for user %s\n", session[i].user);
-                       if (session[i].ip)
-                               sessionsetup(session[i].tunnel, i);
-               }
-       }
-
-       fclose(f);
-       LOG(0, 0, 0, "Loaded saved state information\n");
-}
-
-static void dump_state()
-{
-       FILE *f;
-       uint32_t buf[2];
-
-       if (!config->save_state)
-               return;
-
-       do
-       {
-               if (!(f = fopen(STATEFILE, "w")))
-                       break;
-
-               LOG(1, 0, 0, "Dumping state information\n");
-
-               if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC) - 1, 1, f) != 1)
-                       break;
-
-               LOG(2, 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, "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, "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, "Can't write state information: %s\n", strerror(errno));
-       unlink(STATEFILE);
-}
-
 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
 {
        MD5_CTX ctx;
@@ -3808,13 +4109,13 @@ int sessionsetup(tunnelidt t, sessionidt s)
 
        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, s, t, "   No IP allocated.  The IP address pool is FULL!\n");
-                       sessionshutdown(s, "No IP addresses available");
+                       sessionshutdown(s, "No IP addresses available", 2, 7);
                        return 0;
                }
                LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
@@ -3857,6 +4158,7 @@ int sessionsetup(tunnelidt t, sessionidt s)
                // 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);
@@ -3979,6 +4281,10 @@ int load_session(sessionidt s, sessiont *new)
                }
        }
 
+       // 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]))
        {
@@ -4406,7 +4712,7 @@ 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]);
@@ -4438,7 +4744,7 @@ 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;
@@ -4476,7 +4782,7 @@ 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;
@@ -4503,75 +4809,45 @@ 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(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length)
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
 {
        MD5_CTX ctx;
-       uint8_t *cursor;
        uint8_t digest[16];
-       uint8_t working_vector[16];
-       uint16_t hidden_length;
-       uint8_t type[2];
-       size_t done, todo;
-       uint8_t *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 *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]);
-
-       // Keep these for later use
-       working_vector[0] = *cursor;
-       working_vector[1] = *(cursor + 1);
-       cursor += 2;
-
-       if (hidden_length > length - 8)
-       {
-               LOG(1, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length);
-               return 0;
-       }
+       // pointer to last decoded 16 octets
+       last = value;
 
-       /* Decrypt remainder */
-       done = 2;
-       todo = hidden_length;
-       while (todo)
+       while (len > 0)
        {
-               working_vector[done] = *cursor;
-               *output = digest[done] ^ *cursor;
-               ++output;
-               ++cursor;
-               --todo;
-               ++done;
-               if (done == 16 && todo)
+               // calculate a new pad based on the last decoded block
+               if (d >= sizeof(digest))
                {
-                       // Compute new digest
-                       done = 0;
                        MD5Init(&ctx);
                        MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-                       MD5Update(&ctx, &working_vector, 16);
+                       MD5Update(&ctx, last, sizeof(digest));
                        MD5Final(digest, &ctx);
+
+                       d = 0;
+                       last = value;
                }
-       }
 
-       return hidden_length + 6;
+               *value++ ^= digest[d++];
+               len--;
+       }
 }
 
 static int ip_filter_port(ip_filter_portt *p, uint16_t port)