X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/67fb382676922a55ea4e9b3bff5f9a368c8765e7..560fad4be9a737cce1990547b0ebf5195646dd3d:/l2tpns.c?ds=sidebyside

diff --git a/l2tpns.c b/l2tpns.c
index 7b8822d..39f72d7 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -1,8 +1,11 @@
 // L2TP Network Server
 // Adrian Kennard 2002
-// (c) Copyrigth 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd)
+// 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 1.150 2005/11/17 07:35:35 bodea Exp $";
+
 #include <arpa/inet.h>
 #include <assert.h>
 #include <errno.h>
@@ -16,24 +19,27 @@
 #include <sys/mman.h>
 #include <netdb.h>
 #include <netinet/in.h>
-#include <signal.h>
+#include <netinet/ip6.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
-#define __USE_GNU
 #include <string.h>
+#include <ctype.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/resource.h>
-#include <sys/types.h>
 #include <sys/wait.h>
 #include <linux/if.h>
 #include <stddef.h>
 #include <time.h>
 #include <dlfcn.h>
 #include <unistd.h>
+#include <sched.h>
+#include <sys/sysinfo.h>
+#include <libcli.h>
+
 #include "md5.h"
 #include "l2tpns.h"
 #include "cluster.h"
@@ -42,68 +48,109 @@
 #include "constants.h"
 #include "control.h"
 #include "util.h"
+#include "tbf.h"
+
+#ifdef BGP
+#include "bgp.h"
+#endif
 
 // Globals
-struct configt *config = NULL;	// all configuration
-int tapfd = -1;			// tap interface file handle
+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
+int clifd = -1;			// Socket listening for CLI connections.
+int daefd = -1;			// Socket listening for DAE 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
+int rand_fd = -1;		// Random data source
+int cluster_sockfd = -1;	// Intra-cluster communications socket.
+int epollfd = -1;		// event polling
 time_t basetime = 0;		// base clock
 char hostname[1000] = "";	// us.
-ipt myip = 0;			// MY IP
-u16 tapmac[3];			// MAC of tap interface
-int tapidx;			// ifr_ifindex of tap device
-u32 sessionid = 0;		// session id for radius accounting
-int syslog_log = 0;		// are we logging to syslog
-FILE *log_stream = NULL;
-struct sockaddr_in snoop_addr = {0};
-extern int cluster_sockfd;
-unsigned long last_sid = 0;
-int clifd = 0;
-sessionidt *cli_session_kill = NULL;
-tunnelidt *cli_tunnel_kill = NULL;
-static void *ip_hash[256];
-unsigned long udp_tx = 0, udp_rx = 0, udp_rx_pkt = 0;
-unsigned long eth_tx = 0, eth_rx = 0, eth_rx_pkt = 0;
-unsigned int ip_pool_size = 0;
-time_t time_now;
-char time_now_string[64] = {0};
-char main_quit = 0;
-char *_program_name = NULL;
+static int tunidx;		// ifr_ifindex of tun device
+static int syslog_log = 0;	// are we logging to syslog
+static FILE *log_stream = 0;	// file handle for direct logging (i.e. direct into file, not via syslog).
+uint32_t last_id = 0;		// Unique ID for radius accounting
+
+// calculated from config->l2tp_mtu
+uint16_t MRU = 0;		// PPP MRU
+uint16_t MSS = 0;		// TCP MSS
+
+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 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 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.
+int time_changed = 0;			// time_now changed
+char main_quit = 0;			// True if we're in the process of exiting.
+char main_reload = 0;			// Re-load pending
 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("l2tp_secret", l2tpsecret, STRING),
-	CONFIG("primary_dns", default_dns1, IP),
-	CONFIG("secondary_dns", default_dns2, IP),
-	CONFIG("save_state", save_state, BOOL),
-	CONFIG("snoop_host", snoop_destination_host, IP),
-	CONFIG("snoop_port", snoop_destination_port, SHORT),
-	CONFIG("primary_radius", radiusserver[0], IP),
-	CONFIG("secondary_radius", radiusserver[1], IP),
+	CONFIG("pid_file", pid_file, STRING),
+	CONFIG("random_device", random_device, STRING),
+	CONFIG("l2tp_secret", l2tp_secret, STRING),
+	CONFIG("l2tp_mtu", l2tp_mtu, INT),
+	CONFIG("ppp_restart_time", ppp_restart_time, INT),
+	CONFIG("ppp_max_configure", ppp_max_configure, INT),
+	CONFIG("ppp_max_failure", ppp_max_failure, INT),
+	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("cluster_master", cluster_address, IP),
+	CONFIG("radius_authtypes", radius_authtypes_s, STRING),
+	CONFIG("radius_dae_port", radius_dae_port, SHORT),
+	CONFIG("allow_duplicate_users", allow_duplicate_users, BOOL),
+	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),
 	CONFIG("accounting_dir", accounting_dir, STRING),
 	CONFIG("setuid", target_uid, INT),
 	CONFIG("dump_speed", dump_speed, BOOL),
-	CONFIG("cleanup_interval", cleanup_interval, INT),
 	CONFIG("multi_read_count", multi_read_count, INT),
+	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_mcast_ttl", cluster_mcast_ttl, INT),
+	CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
+	CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
+ 	CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
+	CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
 	{ NULL, 0, 0, 0 },
 };
 
-char *plugin_functions[] = {
+static char *plugin_functions[] = {
 	NULL,
 	"plugin_pre_auth",
 	"plugin_post_auth",
@@ -114,51 +161,87 @@ char *plugin_functions[] = {
 	"plugin_kill_session",
 	"plugin_control",
 	"plugin_radius_response",
+	"plugin_radius_reset",
+	"plugin_radius_account",
+	"plugin_become_master",
+	"plugin_new_session_master",
 };
+
 #define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
 
-tunnelt *tunnel = NULL;		// 1000 * 45 = 45000 = 45k
-sessiont *session = NULL;	// 5000 * 213 = 1065000 = 1 Mb
-radiust *radius = NULL;
-ippoolt *ip_address_pool = NULL;
-controlt *controlfree = 0;
+// 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.
+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
-tbft *filter_buckets = NULL;
-
-void sigalrm_handler(int);
-void sighup_handler(int);
-void sigterm_handler(int);
-void sigquit_handler(int);
-void sigchild_handler(int);
-void read_config_file();
-void read_state();
-void dump_state();
-void tunnel_clean();
-tunnelidt new_tunnel();
-void update_config();
-
-// return internal time (10ths since run)
-clockt now(void)
+
+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);
+static void shutdown_handler(int sig);
+static void sigchild_handler(int sig);
+static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response);
+static void update_config(void);
+static void read_config_file(void);
+static void initplugins(void);
+static int add_plugin(char *plugin_name);
+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 void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
+
+// on slaves, alow BGP to withdraw cleanly before exiting
+#define QUIT_DELAY	5
+
+// quit actions (master)
+#define QUIT_FAILOVER	1 // SIGTERM: exit when all control messages have been acked (for cluster failover)
+#define QUIT_SHUTDOWN	2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
+
+// return internal time (10ths since process startup), set f if given
+// as a side-effect sets time_now, and time_changed
+static clockt now(double *f)
 {
 	struct timeval t;
 	gettimeofday(&t, 0);
+	if (f) *f = t.tv_sec + t.tv_usec / 1000000.0;
+	if (t.tv_sec != time_now)
+	{
+	    time_now = t.tv_sec;
+	    time_changed++;
+	}
 	return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
 }
 
 // work out a retry time based on try number
-clockt backoff(u8 try)
+// This is a straight bounded exponential backoff.
+// Maximum re-try time is 32 seconds. (2^5).
+clockt backoff(uint8_t try)
 {
 	if (try > 5) try = 5;                  // max backoff
-	return now() + 10 * (1 << try);
+	return now(NULL) + 10 * (1 << try);
 }
 
-void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...)
+
+//
+// Log a debug message.  Typically called via the LOG macro
+//
+void _log(int level, sessionidt s, tunnelidt t, const char *format, ...)
 {
-	static char message[65535] = {0};
-	static char message2[65535] = {0};
+	static char message[65536] = {0};
 	va_list ap;
 
 #ifdef RINGBUFFER
@@ -171,7 +254,6 @@ 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);
@@ -183,32 +265,27 @@ 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, 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, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize)
+void _log_hex(int level, const char *title, const uint8_t *data, int maxsize)
 {
 	int i, j;
-	unsigned const char *d = (unsigned const char *)data;
+	const uint8_t *d = data;
 
 	if (config->debug < level) return;
 
-	// No support for log_hex to syslog
+	// No support for _log_hex to syslog
 	if (log_stream)
 	{
-		log(level, address, s, t, "%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; )
@@ -249,53 +326,216 @@ void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *tit
 	}
 }
 
+// update a counter, accumulating 2^32 wraps
+void increment_counter(uint32_t *counter, uint32_t *wrap, uint32_t delta)
+{
+	uint32_t new = *counter + delta;
+	if (new < *counter)
+		(*wrap)++;
+
+	*counter = new;
+}
+
+// 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));
+		}
+	}
+}
+
+// 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(NULL);
+			}
+
+			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
-void routeset(ipt ip, ipt mask, ipt gw, u8 add)
+//
+// This adds it to the routing table, advertises it
+// via BGP if enabled, and stuffs it into the
+// 'sessionbyip' cache.
+//
+// 'ip' and 'mask' must be in _host_ order.
+//
+static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
 {
 	struct rtentry r;
+	int i;
+
+	if (!mask) mask = 0xffffffff;
+
+	ip &= mask;		// Force the ip to be the first one in the route.
+
 	memset(&r, 0, sizeof(r));
-	r.rt_dev = config->tapdevice;
+	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 ? mask : 0xFFFFFFF);
+	*(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
+	else if (mask == 0xffffffff)
 		r.rt_flags |= RTF_HOST;
-	if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0) perror("routeset");
-	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 & 255, ip >> 8 & 255, ip & 255, mask >> 24, mask >> 16 & 255, mask >> 8 & 255, mask & 255, gw >> 24, gw >> 16 & 255, gw >> 8 & 255, gw & 255);
+
+	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, "routeset() error in ioctl: %s\n", strerror(errno));
+
+#ifdef BGP
+	if (add)
+		bgp_add_route(htonl(ip), htonl(mask));
+	else
+		bgp_del_route(htonl(ip), htonl(mask));
+#endif /* BGP */
+
+		// Add/Remove the IPs to the 'sessionbyip' cache.
+		// Note that we add the zero address in the case of
+		// a network route. Roll on CIDR.
+
+		// Note that 's == 0' implies this is the address pool.
+		// We still cache it here, because it will pre-fill
+		// the malloc'ed tree.
+
+	if (s)
+	{
+		if (!add)	// Are we deleting a route?
+			s = 0;	// Caching the session as '0' is the same as uncaching.
+
+		for (i = ip; (i&mask) == (ip&mask) ; ++i)
+			cache_ipmap(i, s);
+	}
+}
+
+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;
 }
 
-// Set up TAP interface
-void inittap(void)
+// 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;
 
-	tapfd = open(TAPDEVICE, O_RDWR);
-	if (tapfd < 0)
+	tunfd = open(TUNDEVICE, O_RDWR);
+	if (tunfd < 0)
 	{                          // fatal
-		log(0, 0, 0, 0, "Can't open %s: %s\n", TAPDEVICE, strerror(errno));
-		exit(-1);
+		LOG(0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
+		exit(1);
 	}
 	{
-		int flags = fcntl(tapfd, F_GETFL, 0);
-		fcntl(tapfd, F_SETFL, flags | O_NONBLOCK);
+		int flags = fcntl(tunfd, F_GETFL, 0);
+		fcntl(tunfd, F_SETFL, flags | O_NONBLOCK);
 	}
-	if (ioctl(tapfd, TUNSETIFF, (void *) &ifr) < 0)
+	if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
 	{
-		log(0, 0, 0, 0, "Can't set tap interface: %s\n", strerror(errno));
-		exit(-1);
+		LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
+		exit(1);
 	}
-	assert(strlen(ifr.ifr_name) < sizeof(config->tapdevice));
-	strncpy(config->tapdevice, ifr.ifr_name, sizeof(config->tapdevice) - 1);
+	assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
+	strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
 	ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
 
 	sin.sin_family = AF_INET;
@@ -304,38 +544,69 @@ void inittap(void)
 
 	if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
 	{
-		perror("set tap addr");
-		exit( -1);
+		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)
 	{
-		perror("set tap qlen");
-		exit( -1);
+		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)
+	/* set MTU to modem MRU + 4 (tun header) */
+	ifr.ifr_mtu = MRU + 4;
+	if (ioctl(ifrfd, SIOCSIFMTU, (void *) &ifr) < 0)
 	{
-		perror("set tap flags");
-		exit( -1);
+		LOG(0, 0, 0, "Error setting tun MTU: %s\n", strerror(errno));
+		exit(1);
 	}
-	if (ioctl(ifrfd, SIOCGIFHWADDR, (void *) &ifr) < 0)
+	ifr.ifr_flags = IFF_UP;
+	if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
 	{
-		perror("get tap hwaddr");
-		exit( -1);
+		LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
+		exit(1);
 	}
-	memcpy(&tapmac, 2 + (u8 *) & ifr.ifr_hwaddr, 6);
 	if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
 	{
-		perror("get tap ifindex");
-		exit( -1);
+		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]) {
+		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));
+		}
 	}
-	tapidx = ifr.ifr_ifindex;
 }
 
-// set up UDP port
-void initudp(void)
+// set up UDP ports
+static void initudp(void)
 {
 	int on = 1;
 	struct sockaddr_in addr;
@@ -345,7 +616,7 @@ void initudp(void)
 	addr.sin_family = AF_INET;
 	addr.sin_port = htons(L2TPPORT);
 	addr.sin_addr.s_addr = config->bind_address;
-	udpfd = socket(AF_INET, SOCK_DGRAM, UDP);
+	udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
 	{
 		int flags = fcntl(udpfd, F_GETFL, 0);
@@ -353,119 +624,293 @@ void initudp(void)
 	}
 	if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
 	{
-		perror("udp bind");
-		exit( -1);
+		LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
+		exit(1);
 	}
-	snoopfd = socket(AF_INET, SOCK_DGRAM, UDP);
 
 	// 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)
 	{
-		perror("bind");
-		exit(-1);
+		LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
+		exit(1);
+	}
+
+	// Dynamic Authorization Extensions to RADIUS
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(config->radius_dae_port);
+	daefd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	setsockopt(daefd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+	if (bind(daefd, (void *) &addr, sizeof(addr)) < 0)
+	{
+		LOG(0, 0, 0, "Error in DAE bind: %s\n", strerror(errno));
+		exit(1);
 	}
+
+	// Intercept
+	snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 }
 
-// Find session by IP, 0 for not found
-sessionidt sessionbyip(ipt ip)
+//
+// Find session by IP, < 1 for not found
+//
+// Confusingly enough, this 'ip' must be
+// in _network_ order. This being the common
+// case when looking it up from IP packet headers.
+//
+// We actually use this cache for two things.
+// #1. For used IP addresses, this maps to the
+// session ID that it's used by.
+// #2. For un-used IP addresses, this maps to the
+// index into the pool table that contains that
+// IP address.
+//
+
+static int lookup_ipmap(in_addr_t ip)
 {
-	unsigned char *a = (unsigned char *)&ip;
-	char **d = (char **) ip_hash;
-	sessionidt s;
+	uint8_t *a = (uint8_t *) &ip;
+	uint8_t **d = (uint8_t **) ip_hash;
 
-#ifdef STAT_CALLS
-	STAT(call_sessionbyip);
-#endif
+	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)
+{
+	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].opened)
+		return (sessionidt) s;
+
+	return 0;
+}
 
-	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;
+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] == 0 &&
+		 ip.s6_addr16[2] == 0 &&
+		 ip.s6_addr16[3] == 0)) {
+		s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
+	} else {
+		s = lookup_ipv6map(ip);
+	}
 
-	s = (ipt) d[(size_t) *a];
-	if (s && session[s].tunnel)
+	if (s > 0 && s < MAXSESSION && session[s].opened)
 		return s;
+
 	return 0;
 }
 
-void cache_sessionid(ipt ip, sessionidt s)
+//
+// Take an IP address in HOST byte order and
+// add it to the sessionid by IP cache.
+//
+// (It's actually cached in network order)
+//
+static void cache_ipmap(in_addr_t ip, int s)
 {
-	unsigned char *a = (unsigned char *) &ip;
-	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]];
 	}
 
-	log(4, ip, s, session[s].tunnel, "Caching session ID %d for ip address\n", s);
-	d[(size_t) a[3]] = (char *)((int)s);
+	d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
+
+	if (s > 0)
+		LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
+
+	else if (s == 0)
+		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(in_addr_t ip)
+{
+	cache_ipmap(ip, 0);	// Assign it to the NULL session.
 }
 
-void uncache_sessionid(ipt ip)
+static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
 {
-	unsigned char *a = (unsigned char *) &ip;
-	char **d = (char **) ip_hash;
 	int i;
+	int bytes;
+	struct ipv6radix *curnode;
+	char ipv6addr[INET6_ADDRSTRLEN];
 
-	for (i = 0; i < 3; i++)
+	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.
+//
+int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
+{
+	char **d = (char **) ip_hash, **e, **f, **g;
+	int i, j, k, l;
+	int count = 0;
+
+	if (CLI_HELP_REQUESTED)
+		return CLI_HELP_NO_ARGS;
+
+	cli_print(cli, "%7s %s", "Sess#", "IP Address");
+
+	for (i = 0; i < 256; ++i)
 	{
-		if (!d[(size_t) a[i]]) return;
-		d = (char **) d[(size_t) a[i]];
+		if (!d[i])
+			continue;
+		e = (char **) d[i];
+		for (j = 0; j < 256; ++j)
+		{
+			if (!e[j])
+				continue;
+			f = (char **) e[j];
+			for (k = 0; k < 256; ++k)
+			{
+				if (!f[k])
+					continue;
+				g = (char **)f[k];
+				for (l = 0; l < 256; ++l)
+				{
+					if (!g[l])
+						continue;
+					cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
+					++count;
+				}
+			}
+		}
 	}
-	d[(size_t) a[3]] = NULL;
+	cli_print(cli, "%d entries in cache", count);
+	return CLI_OK;
 }
 
+
 // Find session by username, 0 for not found
 // walled garden users aren't authenticated, so the username is
 // reasonably useless. Ignore them to avoid incorrect actions
+//
+// This is VERY inefficent. Don't call it often. :)
+//
 sessionidt sessionbyuser(char *username)
 {
 	int s;
-#ifdef STAT_CALLS
-	STAT(call_sessionbyuser);
-#endif
-	for (s = 1; s < MAXSESSION && (session[s].walled_garden || strncmp(session[s].user, username, 128)); s++);
-	if (s < MAXSESSION)
-		return s;
-	return 0;
+	CSTAT(sessionbyuser);
+
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
+	{
+		if (!session[s].opened)
+			continue;
+
+		if (session[s].walled_garden)
+			continue;		// Skip walled garden users.
+
+		if (!strncmp(session[s].user, username, 128))
+			return s;
+
+	}
+	return 0;	// Not found.
 }
 
-void send_garp(ipt ip)
+void send_garp(in_addr_t ip)
 {
 	int s;
 	struct ifreq ifr;
-	unsigned char 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;
 	}
@@ -473,123 +918,30 @@ void send_garp(ipt ip)
 	sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
-// Find session by username, 0 for not found
-sessiont *sessiontbysessionidt(sessionidt s)
+static sessiont *sessiontbysessionidt(sessionidt s)
 {
-	if (!s || s > MAXSESSION) return NULL;
+	if (!s || s >= MAXSESSION) return NULL;
 	return &session[s];
 }
 
-sessionidt sessionidtbysessiont(sessiont *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;
 }
 
-// send gratuitous ARP to set ARP table for newly allocated IP
-void sessionsendarp(sessionidt s)
-{
-        unsigned char mac[6];
-#ifdef STAT_CALLS
-	STAT(call_sendarp);
-#endif
-	*(u16 *) (mac + 0) = htons(tapmac[0]); // set source address
-	*(u16 *) (mac + 2) = htons(tapmac[1]);
-	*(u16 *) (mac + 4) = htons(tapmac[2]);
-	sendarp(tapidx, mac, session[s].ip);
-	STAT(arp_sent);
-}
-
-// Handle ARP requests
-void processarp(u8 * buf, int len)
-{
-	ipt ip;
-	sessionidt s;
-
-#ifdef STAT_CALLS
-	STAT(call_processarp);
-#endif
-	STAT(arp_recv);
-	if (len != 46)
-	{
-		log(0, 0, 0, 0, "Unexpected length ARP %d bytes\n", len);
-		STAT(arp_errors);
-		return;
-	}
-	if (*(u16 *) (buf + 16) != htons(PKTARP))
-	{
-		log(0, 0, 0, 0, "Unexpected ARP type %04X\n", ntohs(*(u16 *) (buf + 16)));
-		STAT(arp_errors);
-		return;
-	}
-	if (*(u16 *) (buf + 18) != htons(0x0001))
-	{
-		log(0, 0, 0, 0, "Unexpected ARP hard type %04X\n", ntohs(*(u16 *) (buf + 18)));
-		STAT(arp_errors);
-		return;
-	}
-	if (*(u16 *) (buf + 20) != htons(PKTIP))
-	{
-		log(0, 0, 0, 0, "Unexpected ARP prot type %04X\n", ntohs(*(u16 *) (buf + 20)));
-		STAT(arp_errors);
-		return;
-	}
-	if (buf[22] != 6)
-	{
-		log(0, 0, 0, 0, "Unexpected ARP hard len %d\n", buf[22]);
-		STAT(arp_errors);
-		return;
-	}
-	if (buf[23] != 4)
-	{
-		log(0, 0, 0, 0, "Unexpected ARP prot len %d\n", buf[23]);
-		STAT(arp_errors);
-		return;
-	}
-	if (*(u16 *) (buf + 24) != htons(0x0001))
-	{
-		log(0, 0, 0, 0, "Unexpected ARP op %04X\n", ntohs(*(u16 *) (buf + 24)));
-		STAT(arp_errors);
-		return;
-	}
-	ip = ntohl(*(u32 *) (buf + 42));
-	// look up session
-	s = sessionbyip(htonl(ip));
-	if (s)
-	{
-		log(3, ip, s, session[s].tunnel, "ARP reply for %u.%u.%u.%u\n", ip >> 24, ip >> 16 & 255, ip >> 8 & 255, ip & 255);
-		memcpy(buf + 4, buf + 10, 6); // set destination as source
-		*(u16 *) (buf + 10) = htons(tapmac[0]); // set soucre address
-		*(u16 *) (buf + 12) = htons(tapmac[1]);
-		*(u16 *) (buf + 14) = htons(tapmac[2]);
-		*(u16 *) (buf + 24) = htons(0x0002); // ARP reply
-		memcpy(buf + 26, buf + 10, 6); // sender ethernet
-		memcpy(buf + 36, buf + 4, 6); // target ethernet
-		*(u32 *) (buf + 42) = *(u32 *) (buf + 32); // target IP
-		*(u32 *) (buf + 32) = htonl(ip); // sender IP
-		write(tapfd, buf, len);
-		STAT(arp_replies);
-	}
-	else
-	{
-		log(3, ip, 0, 0, "ARP request for unknown IP %u.%u.%u.%u\n", ip >> 24, ip >> 16 & 255, ip >> 8 & 255, ip & 255);
-		STAT(arp_discarded);
-	}
-}
-
 // 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;
 
-#ifdef STAT_CALLS
-	STAT(call_tunnelsend);
-#endif
+	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;
@@ -598,59 +950,135 @@ 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)
 	{
 		tunnel[t].last = time_now; // control message sent
 		tunnel[t].retry = backoff(tunnel[t].try); // when to resend
-		if (tunnel[t].try > 1)
+		if (tunnel[t].try)
 		{
 			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;
 	}
 
-	log_hex(5, "Send Tunnel Data", buf, l);
+	LOG_HEX(5, "Send Tunnel Data", buf, l);
 	STAT(tunnel_tx_packets);
 	INC_STAT(tunnel_tx_bytes, l);
 }
 
+//
+// Tiny helper function to write data to
+// the 'tun' device.
+//
+int tun_write(uint8_t * data, int size)
+{
+	return write(tunfd, data, size);
+}
+
+// adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
+void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
+{
+	int d = (tcp[12] >> 4) * 4;
+	uint8_t *mss = 0;
+	uint8_t *opts;
+	uint8_t *data;
+	uint16_t orig;
+	uint32_t sum;
+
+	if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
+		return;
+
+	if (tcp + d > buf + len) // short?
+		return;
+
+	opts = tcp + 20;
+	data = tcp + d;
+
+	while (opts < data)
+	{
+		if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
+		{
+			mss = opts + 2;
+			if (mss + 2 > data) return; // short?
+			break;
+		}
+
+		if (*opts == 0) return; // end of options
+		if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
+			opts++;
+		else
+			opts += opts[1]; // skip over option
+	}
+
+	if (!mss) return; // not found
+	orig = ntohs(*(uint16_t *) mss);
+
+	if (orig <= MSS) return; // mss OK
+
+	LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
+		fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
+		fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
+		(tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
+
+	// set mss
+	*(int16_t *) mss = htons(MSS);
+
+	// adjust checksum (see rfc1141)
+	sum = orig + (~MSS & 0xffff);
+	sum += ntohs(*(uint16_t *) (tcp + 16));
+	sum = (sum & 0xffff) + (sum >> 16);
+	*(uint16_t *) (tcp + 16) = htons(sum + (sum >> 16));
+}
+
 // process outgoing (to tunnel) IP
-void processipout(u8 * buf, int len)
+//
+static void processipout(uint8_t *buf, int len)
 {
 	sessionidt s;
 	sessiont *sp;
 	tunnelidt t;
-	ipt ip;
-	u8 b[MAXETHER];
-#ifdef STAT_CALLS
-	STAT(call_processipout);
-#endif
+	in_addr_t ip;
+
+	uint8_t *data = buf;	// Keep a copy of the originals.
+	int size = len;
+
+	uint8_t b[MAXETHER + 20];
+
+	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, "Oversize IP packet %d bytes\n", len);
+		STAT(tun_rx_errors);
 		return;
 	}
 
@@ -659,84 +1087,335 @@ 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)))
 	{
-		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);
+		// 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.
+		{
+			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),
+				config->bind_address ? config->bind_address : my_address, buf, len);
+		}
 		return;
 	}
 	t = session[s].tunnel;
 	sp = &session[s];
 
-	// Snooping this session, send it to ASIO
-	if (sp->snoop) snoop_send_packet(buf, len);
-
-	log(5, session[s].ip, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
-
-	// Add on L2TP header
+	// DoS prevention: enforce a maximum number of packets per 0.1s for a session
+	if (config->max_packets > 0)
 	{
-		u8 *p = makeppp(b, buf, len, t, s, PPPIP);
-		tunnelsend(b, len + (p-b), t); // send it...
-		sp->cout += len; // byte count
-		sp->total_cout += len; // byte count
-		sp->pout++;
-		udp_tx += len;
-	}
-}
+		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;
+
+	// adjust MSS on SYN and SYN,ACK packets with options
+	if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
+	{
+		int ihl = (buf[0] & 0xf) * 4; // length of IP header
+		if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
+			adjust_tcp_mss(s, t, buf, len, buf + ihl);
+	}
+
+	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;
+	}
+
+	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, s, t, 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);
+
+	increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
+	sp->cout_delta += len;
+	sp->pout++;
+	udp_tx += len;
+
+	sess_local[s].cout += len;	// To send to master..
+	sess_local[s].pout++;
+}
+
+// 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;
+
+	uint8_t *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, s, t, 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);
+
+	increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
+	sp->cout_delta += len;
+	sp->pout++;
+	udp_tx += len;
+
+	sess_local[s].cout += len;	// To send to master..
+	sess_local[s].pout++;
+}
+
+//
+// Helper routine for the TBF filters.
+// Used to send queued data in to the user!
+//
+static void send_ipout(sessionidt s, uint8_t *buf, int len)
+{
+	sessiont *sp;
+	tunnelidt t;
+	in_addr_t ip;
+
+	uint8_t b[MAXETHER + 20];
+
+	if (len < 0 || len > MAXETHER)
+	{
+		LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
+		return;
+	}
+
+	// Skip the tun header
+	buf += 4;
+	len -= 4;
+
+	ip = *(in_addr_t *)(buf + 16);
+
+	if (!session[s].ip)
+		return;
+
+	t = session[s].tunnel;
+	sp = &session[s];
+
+	LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
+
+	// Add on L2TP header
+	{
+		uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
+		if (!p) return;
+		tunnelsend(b, len + (p-b), t); // send it...
+	}
+
+	// Snooping this session.
+	if (sp->snoop_ip && sp->snoop_port)
+		snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
+
+	increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
+	sp->cout_delta += len;
+	sp->pout++;
+	udp_tx += len;
+
+	sess_local[s].cout += len;	// To send to master..
+	sess_local[s].pout++;
+}
 
 // add an AVP (16 bit)
-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)
-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)
-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
-void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m)
+static void controlb(controlt * c, uint16_t avp, uint8_t *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
-controlt *controlnew(u16 mtype)
+static controlt *controlnew(uint16_t mtype)
 {
 	controlt *c;
 	if (!controlfree)
@@ -748,42 +1427,46 @@ 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;
 }
 
 // send zero block if nothing is waiting
-void controlnull(tunnelidt t)
+// (ZLB send).
+static void controlnull(tunnelidt t)
 {
-	u8 buf[12];
-	if (tunnel[t].controlc)
+	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
-void controladd(controlt * c, tunnelidt t, sessionidt s)
+static void controladd(controlt *c, sessionidt far, tunnelidt t)
 {
-	*(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)
 	{
@@ -792,134 +1475,300 @@ void controladd(controlt * c, tunnelidt t, sessionidt s)
 	}
 }
 
+//
+// Throttle or Unthrottle a session
+//
+// Throttle the data from/to through a session to no more than
+// 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
+// user).
+//
+// If either value is -1, the current value is retained for that
+// direction.
+//
+void throttle_session(sessionidt s, int rate_in, int rate_out)
+{
+	if (!session[s].opened)
+		return; // No-one home.
+
+	if (!*session[s].user)
+	        return; // User not logged in
+
+	if (rate_in >= 0)
+	{
+		int bytes = rate_in * 1024 / 8; // kbits to bytes
+		if (session[s].tbf_in)
+			free_tbf(session[s].tbf_in);
+
+		if (rate_in > 0)
+			session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
+		else
+			session[s].tbf_in = 0;
+
+		session[s].throttle_in = rate_in;
+	}
+
+	if (rate_out >= 0)
+	{
+		int bytes = rate_out * 1024 / 8;
+		if (session[s].tbf_out)
+			free_tbf(session[s].tbf_out);
+
+		if (rate_out > 0)
+			session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
+		else
+			session[s].tbf_out = 0;
+
+		session[s].throttle_out = rate_out;
+	}
+}
+
+// add/remove filters from session (-1 = no change)
+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 dead = session[s].die;
 	int walled_garden = session[s].walled_garden;
 
-#ifdef STAT_CALLS
-	STAT(call_sessionshutdown);
-#endif
-	if (!session[s].tunnel)
+
+	CSTAT(sessionshutdown);
+
+	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)
-		log(2, 0, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
-
-	session[s].die = now() + 150; // Clean up in 15 seconds
-
 	{
 		struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
+		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 && !dead) {
-		u16 r = session[s].radius;
-		if (!r)
+	if (session[s].ip && !walled_garden && !session[s].die)
+	{
+		// RADIUS Stop message
+		uint16_t 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
-		u16 r;
-		if (session[s].route[0].ip)
+		int r;
+		int routed = 0;
+		for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
 		{
-			routeset(session[s].ip, 0, 0, 0);
-			for (r = 0; r < MAXROUTE; r++)
-			{
-				if (session[s].route[r].ip)
-				{
-					routeset(session[s].route[r].ip, session[s].route[r].mask, session[s].ip, 0);
-					session[s].route[r].ip = 0;
-				}
-			}
+			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
+		{
+			if (!routed) routeset(s, session[s].ip, 0, 0, 0);
+			session[s].ip = 0;
 		}
-		if (session[s].throttle) throttle_session(s, 0); session[s].throttle = 0;
-		free_ip_address(s);
+		else
+			free_ip_address(s);
+
+		// unroute IPv6, if setup
+		if (session[s].ppp.ipv6cp == Opened && session[s].ipv6prefixlen)
+			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)
+		{
+			uint8_t 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].far, session[s].tunnel); // send the message
 	}
+
+	if (!session[s].die)
+		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--;
+
+	// clear PPP state
+	memset(&session[s].ppp, 0, sizeof(session[s].ppp));
+	sess_local[s].lcp.restart = 0;
+	sess_local[s].ipcp.restart = 0;
+	sess_local[s].ipv6cp.restart = 0;
+	sess_local[s].ccp.restart = 0;
+
 	cluster_send_session(s);
 }
 
-void sendipcp(tunnelidt t, sessionidt s)
+void sendipcp(sessionidt s, tunnelidt t)
 {
-	u8 buf[MAXCONTROL];
-	u16 r = session[s].radius;
-	u8 *q;
-#ifdef STAT_CALLS
-	STAT(call_sendipcp);
-#endif
-	if (!r)
-		r = radiusnew(s);
-	if (radius[r].state != RADIUSIPCP)
-	{
-		radius[r].state = RADIUSIPCP;
-		radius[r].try = 0;
-	}
-	radius[r].retry = backoff(radius[r].try++);
-	if (radius[r].try > 10)
+	uint8_t buf[MAXETHER];
+	uint8_t *q;
+
+	CSTAT(sendipcp);
+	LOG(3, s, t, "IPCP: send ConfigReq\n");
+
+	if (!session[s].unique_id)
 	{
-		sessionshutdown(s, "No reply on IPCP");
-		return;
+		if (!++last_id) ++last_id; // skip zero
+		session[s].unique_id = last_id;
 	}
-	q = makeppp(buf, 0, 0, t, s, PPPIPCP);
+
+	q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
+	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[4] = 3;
-	q[5] = 6;
-	*(u32 *) (q + 6) = htonl(myip ? myip : session[s].ip); // send my IP (use theirs if I dont have one)
+	q[1] = session[s].unique_id & 0xf;	// ID, dont care, we only send one type of request
+	*(uint16_t *) (q + 2) = htons(10);	// packet length
+	q[4] = 3;				// ip address option
+	q[5] = 6;				// option length
+	*(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
+	restart_timer(s, ipcp);
 }
 
-// kill a session now
-void sessionkill(sessionidt s, char *reason)
+void sendipv6cp(sessionidt s, tunnelidt t)
+{
+	uint8_t buf[MAXETHER];
+	uint8_t *q;
+
+	CSTAT(sendipv6cp);
+	LOG(3, s, t, "IPV6CP: send ConfigReq\n");
+
+	q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
+	if (!q) return;
+
+	*q = ConfigReq;
+	q[1] = session[s].unique_id & 0xf;	// ID, don't care, we
+						// only send one type
+						// of request
+	*(uint16_t *) (q + 2) = htons(14);
+	q[4] = 1;				// interface identifier option
+	q[5] = 10;				// option length
+	*(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
+	restart_timer(s, ipv6cp);
+}
+
+static void sessionclear(sessionidt s)
 {
-#ifdef STAT_CALLS
-	STAT(call_sessionkill);
-#endif
-	sessionshutdown(s, reason);  // close radius/routes, etc.
-	if (session[s].radius)
-		radiusclear(session[s].radius, 0); // cant send clean accounting data, session is killed
-	log(2, 0, s, session[s].tunnel, "Kill session %d: %s\n", s, reason);
 	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
+void sessionkill(sessionidt s, char *reason)
+{
+
+	CSTAT(sessionkill);
+
+	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 (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);
 }
 
+static void tunnelclear(tunnelidt t)
+{
+	if (!t) return;
+	memset(&tunnel[t], 0, sizeof(tunnel[t]));
+	tunnel[t].state = TUNNELFREE;
+}
+
 // kill a tunnel now
-void tunnelkill(tunnelidt t, char *reason)
+static void tunnelkill(tunnelidt t, char *reason)
 {
 	sessionidt s;
 	controlt *c;
-#ifdef STAT_CALLS
-	STAT(call_tunnelkill);
-#endif
+
+	CSTAT(tunnelkill);
 
 	tunnel[t].state = TUNNELDIE;
 
@@ -933,190 +1782,246 @@ 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[t].action = 0;
 	cluster_send_tunnel(t);
-	log(1, 0, 0, t, "Kill tunnel %d: %s\n", t, reason);
-	tunnel[t].die = 0;
-	tunnel[t].state = TUNNELFREE;
 }
 
 // shut down a tunnel cleanly
-void tunnelshutdown(tunnelidt t, char *reason)
+static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
 {
 	sessionidt s;
-#ifdef STAT_CALLS
-	STAT(call_tunnelshutdown);
-#endif
+
+	CSTAT(tunnelshutdown);
+
 	if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
 	{
 		// never set up, can immediately kill
 		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)
-			sessionkill(s, reason);
+			sessionshutdown(s, reason, 0, 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)
+		{
+			uint8_t 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, 0, t);		// 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;
+	uint8_t *chapresponse = NULL;
+	uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
+	uint8_t *p = buf + 2;
 
-#ifdef STAT_CALLS
-	STAT(call_processudp);
-#endif
-	udp_rx += len;
+
+	CSTAT(processudp);
+
+	udp_rx += len;
 	udp_rx_pkt++;
-	log_hex(5, "UDP Data", buf, len);
+	LOG_HEX(5, "UDP Data", buf, len);
 	STAT(tunnel_rx_packets);
 	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");
-		STAT(tunnel_rx_errors);
-		return;
-	}
-	if (s && !session[s].tunnel)
-	{
-		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, "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);
+
+	// used to time out old tunnels
+	if (t && tunnel[t].state == TUNNELOPEN)
+		tunnel[t].lastrec = time_now;
+
 	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
-		if ((*buf & 0xCA) != 0xC8)
-		{
-			log(1, ntohl(addr->sin_addr.s_addr), s, t, "Bad control header %02X\n", *buf);
+		uint16_t message = 0xFFFF;	// message type
+		uint8_t fatal = 0;
+		uint8_t mandatory = 0;
+		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)
+		{
+			master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+			return;
+		}
+
+		// 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);
 			return;
 		}
-		log(3, ntohl(addr->sin_addr.s_addr), s, t, "Control message (%d bytes): %d ns %d nr %d ns %d nr %d\n",
-				l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
+
+		// check for duplicate tunnel open message
+		if (!t && ns == 0)
+		{
+			int i;
+
+				//
+				// Is this a duplicate of the first packet? (SCCRQ)
+				//
+			for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
+			{
+				if (tunnel[i].state != TUNNELOPENING ||
+					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);
 		}
 
-		// This is used to time out old tunnels
-		tunnel[t].lastrec = time_now;
+			// 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;
+		}
 
 		// check sequence of this message
 		{
 			int skip = tunnel[t].window; // track how many in-window packets are still in queue
-			if (tunnel[t].controlc)
-			{                  // some to clear maybe
-				while (tunnel[t].controlc && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
-				{
-					controlt *c = tunnel[t].controls;
-					tunnel[t].controls = c->next;
-					tunnel[t].controlc--;
-					c->next = controlfree;
-					controlfree = c;
-					skip--;
-					tunnel[t].try = 0; // we have progress
-				}
-			}
-			if (tunnel[t].nr < ns && tunnel[t].nr != 0)
+				// some to clear maybe?
+			while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
 			{
-				// is this the sequence we were expecting?
-				log(1, ntohl(addr->sin_addr.s_addr), 0, t, "   Out of sequence tunnel %d, (%d not %d)\n", t, ns, tunnel[t].nr);
-				STAT(tunnel_rx_errors);
-//				controlnull(t);
-				return;
+				controlt *c = tunnel[t].controls;
+				tunnel[t].controls = c->next;
+				tunnel[t].controlc--;
+				c->next = controlfree;
+				controlfree = c;
+				skip--;
+				tunnel[t].try = 0; // we have progress
 			}
+
 			// receiver advance (do here so quoted correctly in any sends below)
-			if (l) tunnel[t].nr++;
+			if (l) tunnel[t].nr = (ns + 1);
 			if (skip < 0) skip = 0;
 			if (skip < tunnel[t].controlc)
 			{
@@ -1141,318 +2046,352 @@ 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)
+					if (!*config->l2tp_secret)
 					{
-						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 (*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
+					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;
+					}
+
+					// Unhide the AVP
+					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;
 				}
-				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%s%s\n", mtype, l2tp_avp_name(mtype), n,
+					flags & 0x40 ? ", hidden" : "", flags & 0x80 ? ", mandatory" : "");
+
 				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_code(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];
-						} else if (message == 14) { /* CDN */
-							if (rescode <= MAX_CDN_RESULT_CODE)
-								resdesc = cdn_result_codes[rescode];
+						if (message == 4)
+						{ /* StopCCN */
+							resdesc = l2tp_stopccn_result_code(rescode);
 						}
-
-						log(4, ntohl(addr->sin_addr.s_addr), 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);
+						else if (message == 14)
+						{ /* CDN */
+							resdesc = l2tp_cdn_result_code(rescode);
 						}
-						if (n > 4) {
-							/* %*s doesn't work?? */
-							char *buf = (char *)strndup(b+4, n-4);
-							log(4, ntohl(addr->sin_addr.s_addr), s, t, "   Error String: %s\n",
-								buf);
-							free(buf);
+
+						LOG(4, s, t, "   Result Code %d: %s\n", rescode, resdesc);
+						if (n >= 4)
+						{
+							uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
+							LOG(4, s, t, "   Error Code %d: %s\n", errcode, l2tp_error_code(errcode));
 						}
+						if (n > 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, 128);
-					memcpy(tunnel[t].vendor, b, (n >= 127) ? 127 : n);
-					log(4, ntohl(addr->sin_addr.s_addr), s, t, "   Vendor name = \"%s\"\n", tunnel[t].vendor);
+					memset(tunnel[t].vendor, 0, sizeof(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, 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 <%lu>\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 <%lu>\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, ppp_auth_type(atype));
 						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");
 						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);
 						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;
-						while (p < e && p[1])
+						uint8_t *p = b, *e = p + n;
+						while (p + 1 < e && p[1] && p + p[1] <= e)
 						{
-							if (*p == 5 && p[1] == 6)
-								amagic = ntohl(*(u32 *) (p + 2));
-							else if (*p == 3 && p[1] == 5 && *(u16 *) (p + 2) == htons(PPPCHAP) && p[4] == 5)
-								chap = 1;
-							else if (*p == 7)
-								aflags |= SESSIONPFC;
-							else if (*p == 8)
-								aflags |= SESSIONACFC;
+							if (*p == 5 && p[1] == 6) // Magic-Number
+								amagic = ntohl(*(uint32_t *) (p + 2));
+							else if (*p == 7) // Protocol-Field-Compression
+								aflags |= SESSION_PFC;
+							else if (*p == 8) // Address-and-Control-Field-Compression
+								aflags |= SESSION_ACFC;
 							p += p[1];
 						}
-
-						{
-							char tmp[500] = {0};
-							tmp[0] = ConfigReq;
-							memcpy((tmp + 1), b, n);
-						}
 					}
 					break;
 				case 28:    // last recv lcp confreq
-					{
-						char tmp[500] = {0};
-						tmp[0] = ConfigReq;
-						memcpy((tmp + 1), b, n);
-						break;
-					}
+					break;
 				case 26:    // Initial Received LCP CONFREQ
-					{
-						char tmp[500] = {0};
-						tmp[0] = ConfigReq;
-						memcpy((tmp + 1), b, n);
-					}
 					break;
 				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));
+					if (n > sizeof(session[s].random_vector))
+						n = 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)
 				{
 				case 1:       // SCCRQ - Start Control Connection Request
+					tunnel[t].state = TUNNELOPENING;
+					if (main_quit != QUIT_SHUTDOWN)
 					{
 						controlt *c = controlnew(2); // sending SCCRP
 						control16(c, 2, version, 1); // protocol version
 						control32(c, 3, 3, 1); // framing
-						controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
+						controls(c, 7, hostname, 1); // host name
 						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, 0, t); // send the resply
+					}
+					else
+					{
+						tunnelshutdown(t, "Shutting down", 6, 0, 0);
 					}
-					tunnel[t].state = TUNNELOPENING;
 					break;
 				case 2:       // SCCRP
 					tunnel[t].state = TUNNELOPEN;
@@ -1463,8 +2402,7 @@ 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
@@ -1479,73 +2417,79 @@ 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 && main_quit != QUIT_SHUTDOWN)
 					{
-						u16 r;
-						controlt *c;
+						controlt *c = controlnew(11); // ICRP
 
 						s = sessionfree;
 						sessionfree = session[s].next;
 						memset(&session[s], 0, sizeof(session[s]));
 
-						// make a RADIUS session
-						if (!(r = radiusnew(s)))
-						{
-							log(1, ntohl(addr->sin_addr.s_addr), s, t, "No free RADIUS sessions for ICRQ\n");
-							return;
-						}
+						if (s > config->cluster_highest_sessionid)
+							config->cluster_highest_sessionid = s;
 
-						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;
-						log(3, ntohl(addr->sin_addr.s_addr), s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
+						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, 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);
+						controladd(c, asession, t); // send the reply
+
 						strncpy(session[s].called, called, sizeof(session[s].called) - 1);
 						strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
+
+						session[s].ppp.phase = Establish;
+						session[s].ppp.lcp = Starting;
+
 						STAT(session_created);
+						break;
 					}
-					break;
+
+					{
+						controlt *c = controlnew(14); // CDN
+						if (!sessionfree)
+						{
+							STAT(session_overflow);
+							LOG(1, 0, t, "No free sessions\n");
+							control16(c, 1, 4, 0); // temporary lack of resources
+						}
+						else
+							control16(c, 1, 2, 7); // shutting down, try another
+
+						controladd(c, asession, t); // send the message
+					}
+					return;
 				case 11:      // ICRP
 					// TBA
 					break;
 				case 12:      // ICCN
+					if (amagic == 0) amagic = time_now;
 					session[s].magic = amagic; // set magic number
 					session[s].flags = aflags; // set flags received
-					log(3, ntohl(addr->sin_addr.s_addr), s, t, "Magic %X Flags %X\n", amagic, aflags);
+					session[s].mru = PPPMTU; // default
 					controlnull(t); // ack
-					// In CHAP state, request PAP instead
-					if (requestchap)
-						initlcp(t, s);
+
+					// start LCP
+					sess_local[s].lcp_authtype = config->radius_authprefer;
+					sess_local[s].ppp_mru = MRU;
+					sendlcp(s, t);
+					change_state(s, lcp, RequestSent);
 					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);
@@ -1553,19 +2497,14 @@ 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 proto;
 
-		log_hex(5, "Receive Tunnel Data", p, l);
-		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);
-			return;              // closing session, PPP not processed
-		}
+		LOG_HEX(5, "Receive Tunnel Data", p, l);
 		if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
 		{                     // HDLC address header, discard
 			p += 2;
@@ -1573,1450 +2512,2881 @@ 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;
 		}
 		if (*p & 1)
 		{
-			prot = *p++;
+			proto = *p++;
 			l--;
 		}
 		else
 		{
-			prot = ntohs(*(u16 *) p);
+			proto = ntohs(*(uint16_t *) p);
 			p += 2;
 			l -= 2;
 		}
-		if (prot == PPPPAP)
+
+		if (s && !session[s].opened)	// Is something wrong??
+		{
+			if (!config->cluster_iam_master)
+			{
+				// Pass it off to the master to deal with..
+				master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+				return;
+			}
+
+
+			LOG(1, s, t, "UDP packet contains session which is not opened.  Dropping packet.\n");
+			STAT(tunnel_rx_errors);
+			return;
+		}
+
+		if (proto == PPPPAP)
+		{
+			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; }
+			processpap(s, t, p, l);
+		}
+		else if (proto == PPPCHAP)
+		{
+			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; }
+			processchap(s, t, p, l);
+		}
+		else if (proto == PPPLCP)
 		{
 			session[s].last_packet = time_now;
-			processpap(t, s, p, l);
+			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+			processlcp(s, t, p, l);
 		}
-		else if (prot == PPPCHAP)
+		else if (proto == PPPIPCP)
 		{
 			session[s].last_packet = time_now;
-			processchap(t, s, p, l);
+			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+			processipcp(s, t, p, l);
 		}
-		else if (prot == PPPLCP)
+		else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
 		{
 			session[s].last_packet = time_now;
-			processlcp(t, s, p, l);
+			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+			processipv6cp(s, t, p, l);
 		}
-		else if (prot == PPPIPCP)
+		else if (proto == PPPCCP)
 		{
 			session[s].last_packet = time_now;
-			processipcp(t, s, p, l);
+			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+			processccp(s, t, p, l);
 		}
-		else if (prot == PPPCCP)
+		else if (proto == 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;
-			processccp(t, s, p, l);
+			if (session[s].walled_garden && !config->cluster_iam_master)
+			{
+				master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+				return;
+			}
+
+			processipin(s, t, p, l);
 		}
-		else if (prot == PPPIP)
+		else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
 		{
+			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;
-			processipin(t, s, p, l);
+			if (session[s].walled_garden && !config->cluster_iam_master)
+			{
+				master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+				return;
+			}
+
+			processipv6in(s, t, p, l);
+		}
+		else if (session[s].ppp.lcp == Opened)
+		{
+			uint8_t buf[MAXETHER];
+			uint8_t *q;
+			int mru = session[s].mru;
+			if (mru > sizeof(buf)) mru = sizeof(buf);
+
+			l += 6;
+			if (l > mru) l = mru;
+
+			q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
+			if (!q) return;
+
+			*q = ProtocolRej;
+			*(q + 1) = ++sess_local[s].lcp_ident;
+			*(uint16_t *)(q + 2) = htons(l);
+			*(uint16_t *)(q + 4) = htons(proto);
+			memcpy(q + 6, p, l - 6);
+
+			if (proto == PPPIPV6CP)
+				LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+			else
+				LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+			tunnelsend(buf, l + (q - buf), t);
 		}
 		else
 		{
-			STAT(tunnel_rx_errors);
-			log(1, ntohl(addr->sin_addr.s_addr), s, t, "Unknown PPP protocol %04X\n", prot);
+			LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
+				proto, ppp_state(session[s].ppp.lcp));
 		}
 	}
 }
 
-// read and process packet on tap
-void processtap(u8 * buf, int len)
+// read and process packet on tun
+static void processtun(uint8_t * buf, int len)
 {
-	log_hex(5, "Receive TAP Data", buf, len);
-	STAT(tap_rx_packets);
-	INC_STAT(tap_rx_bytes, len);
-#ifdef STAT_CALLS
-	STAT(call_processtap);
-#endif
+	LOG_HEX(5, "Receive TUN Data", buf, len);
+	STAT(tun_rx_packets);
+	INC_STAT(tun_rx_bytes, len);
+
+	CSTAT(processtun);
+
 	eth_rx_pkt++;
 	eth_rx += len;
 	if (len < 22)
 	{
-		log(1, 0, 0, 0, "Short tap packet %d bytes\n", len);
-		STAT(tap_rx_errors);
+		LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
+		STAT(tun_rx_errors);
 		return;
 	}
-	if (*(u16 *) (buf + 2) == htons(PKTARP)) // ARP
-		processarp(buf, len);
-	else 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])
+		processipv6out(buf, len);
+
+	// Else discard.
 }
 
-// main loop - gets packets on tap or udp and processes them
-void mainloop(void)
+// Handle retries, timeouts.  Runs every 1/10th sec, want to ensure
+// that we look at the whole of the tunnel, radius and session tables
+// every second
+static void regular_cleanups(double period)
 {
-	fd_set cr;
-	int cn, i;
-	u8 buf[65536];
-	struct timeval to;
+	// Next tunnel, radius and session to check for actions on.
+	static tunnelidt t = 0;
+	static int r = 0;
+	static sessionidt s = 0;
+
+	int t_actions = 0;
+	int r_actions = 0;
+	int s_actions = 0;
+
+	int t_slice;
+	int r_slice;
+	int s_slice;
+
+	int i;
+	int a;
+
+	// divide up tables into slices based on the last run
+	t_slice = config->cluster_highest_tunnelid  * period;
+	r_slice = (MAXRADIUS - 1)                   * period;
+	s_slice = config->cluster_highest_sessionid * period;
+
+	if (t_slice < 1)
+	    t_slice = 1;
+	else if (t_slice > config->cluster_highest_tunnelid)
+	    t_slice = config->cluster_highest_tunnelid;
+
+	if (r_slice < 1)
+	    r_slice = 1;
+	else if (r_slice > (MAXRADIUS - 1))
+	    r_slice = MAXRADIUS - 1;
 
-	clockt slow = now();       // occasional functions like session/tunnel expiry, tunnel hello, etc
-	clockt next_acct = slow + ACCT_TIME;
-	clockt next_cluster_ping = slow + 50;
-	clockt next_clean = time_now + config->cleanup_interval;
-	to.tv_sec = 1;
-	to.tv_usec = 0;
-	log(4, 0, 0, 0, "Beginning of main loop. udpfd=%d, tapfd=%d, cluster_sockfd=%d, controlfd=%d\n",
-			udpfd, tapfd, cluster_sockfd, controlfd);
+	if (s_slice < 1)
+	    s_slice = 1;
+	else if (s_slice > config->cluster_highest_sessionid)
+	    s_slice = config->cluster_highest_sessionid;
 
-	FD_ZERO(&cr);
-	FD_SET(udpfd, &cr);
-	FD_SET(tapfd, &cr);
-	FD_SET(controlfd, &cr);
-	FD_SET(clifd, &cr);
-	if (cluster_sockfd) FD_SET(cluster_sockfd, &cr);
-	cn = udpfd;
-	if (cn < tapfd) cn = tapfd;
-	if (cn < controlfd) cn = controlfd;
-	if (cn < clifd) cn = clifd;
-	if (cn < cluster_sockfd) cn = cluster_sockfd;
-	for (i = 0; i < config->num_radfds; i++)
+	LOG(4, 0, 0, "Begin regular cleanup (last %f seconds ago)\n", period);
+
+	for (i = 0; i < t_slice; i++)
 	{
-		if (!radfds[i]) continue;
-		FD_SET(radfds[i], &cr);
-		if (radfds[i] > cn)
-			cn = radfds[i];
+		t++;
+		if (t > config->cluster_highest_tunnelid)
+			t = 1;
+
+		// check for expired tunnels
+		if (tunnel[t].die && tunnel[t].die <= TIME)
+		{
+			STAT(tunnel_timeout);
+			tunnelkill(t, "Expired");
+			t_actions++;
+			continue;
+		}
+		// check for message resend
+		if (tunnel[t].retry && tunnel[t].controlc)
+		{
+			// resend pending messages as timeout on reply
+			if (tunnel[t].retry <= TIME)
+			{
+				controlt *c = tunnel[t].controls;
+				uint8_t w = tunnel[t].window;
+				tunnel[t].try++; // another try
+				if (tunnel[t].try > 5)
+					tunnelkill(t, "Timeout on control message"); // game over
+				else
+					while (c && w--)
+					{
+						tunnelsend(c->buf, c->length, t);
+						c = c->next;
+					}
+
+				t_actions++;
+			}
+		}
+		// Send hello
+		if (tunnel[t].state == TUNNELOPEN && !tunnel[t].controlc && (time_now - tunnel[t].lastrec) > 60)
+		{
+			controlt *c = controlnew(6); // sending HELLO
+			controladd(c, 0, t); // send the message
+			LOG(3, 0, t, "Sending HELLO message\n");
+			t_actions++;
+		}
+
+		// Check for tunnel changes requested from the CLI
+		if ((a = cli_tunnel_actions[t].action))
+		{
+			cli_tunnel_actions[t].action = 0;
+			if (a & CLI_TUN_KILL)
+			{
+				LOG(2, 0, t, "Dropping tunnel by CLI\n");
+				tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
+				t_actions++;
+			}
+		}
 	}
 
-	while (!main_quit)
+	for (i = 0; i < r_slice; i++)
 	{
-		fd_set r;
-		int n = cn;
+		r++;
+		if (r >= MAXRADIUS)
+			r = 1;
 
-		if (config->reload_config)
+		if (!radius[r].state)
+			continue;
+
+		if (radius[r].retry <= TIME)
 		{
-			// Update the config state based on config settings
-			update_config();
+			radiusretry(r);
+			r_actions++;
 		}
+	}
 
-		memcpy(&r, &cr, sizeof(fd_set));
-		n = select(n + 1, &r, 0, 0, &to);
-		if (n < 0)
+	for (i = 0; i < s_slice; i++)
+	{
+		s++;
+		if (s > config->cluster_highest_sessionid)
+			s = 1;
+
+		if (!session[s].opened)	// Session isn't in use
+			continue;
+
+		// check for expired sessions
+		if (session[s].die)
 		{
-			if (errno != EINTR)
+			if (session[s].die <= TIME)
 			{
-				perror("select");
-				exit( -1);
+				sessionkill(s, "Expired");
+				s_actions++;
 			}
+			continue;
 		}
-		else if (n)
+
+		// PPP timeouts
+		if (sess_local[s].lcp.restart <= time_now)
 		{
-			struct sockaddr_in addr;
-			int alen = sizeof(addr);
-			if (FD_ISSET(udpfd, &r))
+			int next_state = session[s].ppp.lcp;
+			switch (session[s].ppp.lcp)
 			{
-				int c, n;
-				for (c = 0; c < config->multi_read_count; c++)
+			case RequestSent:
+			case AckReceived:
+			    	next_state = RequestSent;
+
+			case AckSent:
+				if (sess_local[s].lcp.conf_sent < config->ppp_max_configure)
 				{
-					if ((n = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
-						processudp(buf, n, &addr);
-					else
-						break;
+					LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
+					sendlcp(s, session[s].tunnel);
+					change_state(s, lcp, next_state);
 				}
-			}
-			if (FD_ISSET(tapfd, &r))
-			{
-				int c, n;
-				for (c = 0; c < config->multi_read_count; c++)
+				else
 				{
-					if ((n = read(tapfd, buf, sizeof(buf))) > 0)
-						processtap(buf, n);
-					else
-						break;
+					sessionshutdown(s, "No response to LCP ConfigReq.", 3, 0);
+					STAT(session_timeout);
 				}
+
+				s_actions++;
 			}
-			for (i = 0; i < config->num_radfds; i++)
-				if (FD_ISSET(radfds[i], &r))
-					processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
-			if (FD_ISSET(cluster_sockfd, &r))
-				processcluster(buf, recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen));
-			if (FD_ISSET(controlfd, &r))
-				processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr);
-			if (FD_ISSET(clifd, &r))
+
+			if (session[s].die)
+				continue;
+		}
+
+		if (sess_local[s].ipcp.restart <= time_now)
+		{
+			int next_state = session[s].ppp.ipcp;
+			switch (session[s].ppp.ipcp)
 			{
-				struct sockaddr_in addr;
-				int sockfd;
-				int len = sizeof(addr);
+			case RequestSent:
+			case AckReceived:
+			    	next_state = RequestSent;
 
-				if ((sockfd = accept(clifd, (struct sockaddr *)&addr, &len)) <= 0)
+			case AckSent:
+				if (sess_local[s].ipcp.conf_sent < config->ppp_max_configure)
 				{
-					log(0, 0, 0, 0, "accept error: %s\n", strerror(errno));
-					continue;
+					LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
+					sendipcp(s, session[s].tunnel);
+					change_state(s, ipcp, next_state);
 				}
 				else
 				{
-					cli_do(sockfd);
-					close(sockfd);
+					sessionshutdown(s, "No response to IPCP ConfigReq.", 3, 0);
+					STAT(session_timeout);
 				}
+
+				s_actions++;
 			}
-		}
 
-		/* Handle timeouts. Make sure that this gets run anyway, even if there was
-		 * something to read, else under load this will never actually run....
-		 */
-		if (n == 0 || next_clean <= time_now) {
-			clockt when = now();
-			clockt best = when + 100; // default timeout
-			sessionidt s;
-			tunnelidt t;
-			int count;
-			u16 r;
+			if (session[s].die)
+				continue;
+		}
 
-			log(3, 0, 0, 0, "Begin regular cleanup\n");
-			for (r = 1; r < MAXRADIUS; r++)
+		if (sess_local[s].ipv6cp.restart <= time_now)
+		{
+			int next_state = session[s].ppp.ipv6cp;
+			switch (session[s].ppp.ipv6cp)
 			{
-				if (radius[r].state && radius[r].retry)
+			case RequestSent:
+			case AckReceived:
+			    	next_state = RequestSent;
+
+			case AckSent:
+				if (sess_local[s].ipv6cp.conf_sent < config->ppp_max_configure)
+				{
+					LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
+					sendipv6cp(s, session[s].tunnel);
+					change_state(s, ipv6cp, next_state);
+				}
+				else
 				{
-					if (radius[r].retry <= when)
-						radiusretry(r);
-					if (radius[r].retry && radius[r].retry < best)
-						best = radius[r].retry;
+					LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq\n");
+					change_state(s, ipv6cp, Stopped);
 				}
-				else if (radius[r].state && !radius[r].retry)
-					radius[r].retry = backoff(radius[r].try+1);
+
+				s_actions++;
 			}
-			for (t = 1; t < MAXTUNNEL; t++)
+		}
+
+		if (sess_local[s].ccp.restart <= time_now)
+		{
+			int next_state = session[s].ppp.ccp;
+			switch (session[s].ppp.ccp)
 			{
-				// check for expired tunnels
-				if (tunnel[t].die && tunnel[t].die <= when)
+			case RequestSent:
+			case AckReceived:
+			    	next_state = RequestSent;
+
+			case AckSent:
+				if (sess_local[s].ccp.conf_sent < config->ppp_max_configure)
 				{
-					STAT(tunnel_timeout);
-					tunnelkill(t, "Expired");
-					continue;
+					LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
+					sendccp(s, session[s].tunnel);
+					change_state(s, ccp, next_state);
 				}
-				// check for message resend
-				if (tunnel[t].retry && tunnel[t].controlc)
+				else
 				{
-					// resend pending messages as timeout on reply
-					if (tunnel[t].retry <= when)
-					{
-						controlt *c = tunnel[t].controls;
-						u8 w = tunnel[t].window;
-						tunnel[t].try++; // another try
-						if (tunnel[t].try > 5)
-							tunnelkill(t, "Timeout on control message"); // game over
-						else
-							while (c && w--)
-							{
-								tunnelsend(c->buf, c->length, t);
-								c = c->next;
-							}
-					}
-					if (tunnel[t].retry && tunnel[t].retry < best)
-						best = tunnel[t].retry;
-				}
-				// Send hello
-				if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < when + 600)
-				{
-					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, s, session[s].tunnel, "No ACK for CCP ConfigReq\n");
+					change_state(s, ccp, Stopped);
 				}
+
+				s_actions++;
+			}
+		}
+
+		// 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.", 3, 0);
+			STAT(session_timeout);
+			s_actions++;
+			continue;
+		}
+
+		// No data in ECHO_TIMEOUT seconds, send LCP ECHO
+		if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
+			(time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
+		{
+			uint8_t b[MAXETHER];
+
+			uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
+			if (!q) continue;
+
+			*q = EchoReq;
+			*(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, 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
+			sess_local[s].last_echo = time_now;
+			s_actions++;
+		}
+
+		// Check for actions requested from the CLI
+		if ((a = cli_session_actions[s].action))
+		{
+			int send = 0;
+
+			cli_session_actions[s].action = 0;
+			if (a & CLI_SESS_KILL)
+			{
+				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
+				s_actions++;
 			}
 
-			// Check for sessions that have been killed from the CLI
-			if (cli_session_kill[0])
+			if (a & CLI_SESS_NOSNOOP)
 			{
-				int i;
-				for (i = 0; i < MAXSESSION && cli_session_kill[i]; i++)
-				{
-					log(2, 0, cli_session_kill[i], 0, "Dropping session by CLI\n");
-					sessionshutdown(cli_session_kill[i], "Requested by administrator");
-					cli_session_kill[i] = 0;
-				}
+				LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
+				session[s].snoop_ip = 0;
+				session[s].snoop_port = 0;
+				s_actions++;
+				send++;
 			}
-			// Check for tunnels that have been killed from the CLI
-			if (cli_tunnel_kill[0])
+			else if (a & CLI_SESS_SNOOP)
 			{
-				int i;
-				for (i = 1; i < MAXTUNNEL && cli_tunnel_kill[i]; i++)
-				{
-					log(2, 0, cli_tunnel_kill[i], 0, "Dropping tunnel by CLI\n");
-					tunnelshutdown(cli_tunnel_kill[i], "Requested by administrator");
-					cli_tunnel_kill[i] = 0;
-				}
+				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;
+				s_actions++;
+				send++;
 			}
 
-			count = 0;
-			for (s = 1; s < MAXSESSION; s++)
+			if (a & CLI_SESS_NOTHROTTLE)
 			{
-				// check for expired sessions
-				if (session[s].die && session[s].die <= when)
-				{
-					sessionkill(s, "Expired");
-					if (++count >= 1000) break;
-					continue;
-				}
+				LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
+				throttle_session(s, 0, 0);
+				s_actions++;
+				send++;
+			}
+			else if (a & CLI_SESS_THROTTLE)
+			{
+				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);
 
-				// 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");
-					STAT(session_timeout);
-					if (++count >= 1000) break;
-					continue;
-				}
+				throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
+				s_actions++;
+				send++;
+			}
 
-				// No data in IDLE_TIMEOUT seconds, send LCP ECHO
-				if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
-				{
-					u8 b[MAXCONTROL] = {0};
-					u8 *q = makeppp(b, 0, 0, session[s].tunnel, s, PPPLCP);
-
-					*q = EchoReq;
-					*(u8 *)(q + 1) = (time_now % 255); // ID
-					*(u16 *)(q + 2) = htons(8); // Length
-					*(u32 *)(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",
-							(int)(time_now - session[s].last_packet));
-					tunnelsend(b, 24, session[s].tunnel); // send it
-					if (++count >= 1000) break;
-					continue;
-				}
+			if (a & CLI_SESS_NOFILTER)
+			{
+				LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
+				filter_session(s, 0, 0);
+				s_actions++;
+				send++;
 			}
-			if (config->accounting_dir && next_acct <= when)
+			else if (a & CLI_SESS_FILTER)
 			{
-				// Dump accounting data
-				next_acct = when + ACCT_TIME;
-				dump_acct_info();
+				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);
+				s_actions++;
+				send++;
 			}
 
-			if (cluster_sockfd && next_cluster_ping <= when)
+			if (send)
+				cluster_send_session(s);
+		}
+
+		// 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)
+		{
+		    	int rad = radiusnew(s);
+			if (!rad)
 			{
-				// Dump accounting data
-				next_cluster_ping = when + 50;
-				cluster_send_message(config->cluster_address, config->bind_address, C_PING, hostname, strlen(hostname));
+				LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
+				STAT(radius_overflow);
+				continue;
 			}
 
-			if (best < when + config->cleanup_interval)
-				best = when + config->cleanup_interval; // Throttle to at most once per 10 seconds
-			next_clean = time_now + config->cleanup_interval;
-			to.tv_sec = config->cleanup_interval;
-			to.tv_usec = 0;
-			log(3, 0, 0, 0, "End regular cleanup, next in %d seconds\n", config->cleanup_interval);
+			LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
+				session[s].user, session[s].unique_id);
+
+			radiussend(rad, RADIUSINTERIM);
+			sess_local[s].last_interim = time_now;
+			s_actions++;
 		}
 	}
+
+	LOG(4, 0, 0, "End regular cleanup: checked %d/%d/%d tunnels/radius/sessions; %d/%d/%d actions\n",
+		t_slice, r_slice, s_slice, t_actions, r_actions, s_actions);
 }
 
-// Init data structures
-void initdata(void)
+//
+// Are we in the middle of a tunnel update, or radius
+// requests??
+//
+static int still_busy(void)
 {
 	int i;
+	static clockt last_talked = 0;
+	static clockt start_busy_wait = 0;
 
-	_statistics = mmap(NULL, sizeof(struct Tstats), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (_statistics == MAP_FAILED)
+	if (!config->cluster_iam_master)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for _statistics: %s\n", strerror(errno));
-		exit(1);
+#ifdef BGP
+		static time_t stopped_bgp = 0;
+	    	if (bgp_configured)
+		{
+			if (!stopped_bgp)
+			{
+			    	LOG(1, 0, 0, "Shutting down in %d seconds, stopping BGP...\n", QUIT_DELAY);
+
+				for (i = 0; i < BGP_NUM_PEERS; i++)
+					if (bgp_peers[i].state == Established)
+						bgp_stop(&bgp_peers[i]);
+
+				stopped_bgp = time_now;
+
+				// we don't want to become master
+				cluster_send_ping(0);
+
+				return 1;
+			}
+
+			if (time_now < (stopped_bgp + QUIT_DELAY))
+				return 1;
+		}
+#endif /* BGP */
+
+		return 0;
 	}
-	config = mmap(NULL, sizeof(struct configt), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (config == MAP_FAILED)
+
+	if (main_quit == QUIT_SHUTDOWN)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for configuration: %s\n", strerror(errno));
-		exit(1);
+		static int dropped = 0;
+		if (!dropped)
+		{
+		    	int i;
+
+			LOG(1, 0, 0, "Dropping sessions and tunnels\n");
+			for (i = 1; i < MAXTUNNEL; i++)
+				if (tunnel[i].ip || tunnel[i].state)
+					tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
+
+			dropped = 1;
+		}
 	}
-	memset(config, 0, sizeof(struct configt));
-	time(&config->start_time);
-	strncpy(config->config_file, CONFIGFILE, sizeof(config->config_file) - 1);
-	tunnel = mmap(NULL, sizeof(tunnelt) * MAXTUNNEL, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (tunnel == MAP_FAILED)
+
+	if (start_busy_wait == 0)
+		start_busy_wait = TIME;
+
+	for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for tunnels: %s\n", strerror(errno));
-		exit(1);
+		if (!tunnel[i].controlc)
+			continue;
+
+		if (last_talked != TIME)
+		{
+			LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
+			last_talked = TIME;
+		}
+		return 1;
 	}
-	session = mmap(NULL, sizeof(sessiont) * MAXSESSION, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (session == MAP_FAILED)
+
+	// We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
+	if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for sessions: %s\n", strerror(errno));
-		exit(1);
+		LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty.  Shutting down anyway.\n");
+		return 0;
 	}
-	radius = mmap(NULL, sizeof(radiust) * MAXRADIUS, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (radius == MAP_FAILED)
+
+	for (i = 1; i < MAXRADIUS; i++)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for radius: %s\n", strerror(errno));
-		exit(1);
+		if (radius[i].state == RADIUSNULL)
+			continue;
+	        if (radius[i].state == RADIUSWAIT)
+			continue;
+
+		if (last_talked != TIME)
+		{
+			LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
+			last_talked = TIME;
+		}
+		return 1;
 	}
-	ip_address_pool = mmap(NULL, sizeof(ippoolt) * MAXIPPOOL, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (ip_address_pool == MAP_FAILED)
+
+	return 0;
+}
+
+#ifdef HAVE_EPOLL
+# include <sys/epoll.h>
+#else
+# define FAKE_EPOLL_IMPLEMENTATION /* include the functions */
+# include "fake_epoll.h"
+#endif
+
+// the base set of fds polled: cli, cluster, tun, udp, control, dae
+#define BASE_FDS	6
+
+// additional polled fds
+#ifdef BGP
+# define EXTRA_FDS	BGP_NUM_PEERS
+#else
+# define EXTRA_FDS	0
+#endif
+
+// main loop - gets packets on tun or udp and processes them
+static void mainloop(void)
+{
+	int i;
+	uint8_t buf[65536];
+	clockt next_cluster_ping = 0;	// send initial ping immediately
+	struct epoll_event events[BASE_FDS + RADIUS_FDS + EXTRA_FDS];
+	int maxevent = sizeof(events)/sizeof(*events);
+
+	if ((epollfd = epoll_create(maxevent)) < 0)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for radius: %s\n", strerror(errno));
+	    	LOG(0, 0, 0, "epoll_create failed: %s\n", strerror(errno));
 		exit(1);
 	}
-#ifdef RINGBUFFER
-	ringbuffer = mmap(NULL, sizeof(struct Tringbuffer), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (ringbuffer == MAP_FAILED)
+
+	LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
+		clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
+
+	/* setup our fds to poll for input */
 	{
-		log(0, 0, 0, 0, "Error doing mmap for radius: %s\n", strerror(errno));
-		exit(1);
+		static struct event_data d[BASE_FDS];
+		struct epoll_event e;
+
+		e.events = EPOLLIN;
+		i = 0;
+
+		d[i].type = FD_TYPE_CLI;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
+
+		d[i].type = FD_TYPE_CLUSTER;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, cluster_sockfd, &e);
+
+		d[i].type = FD_TYPE_TUN;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, tunfd, &e);
+
+		d[i].type = FD_TYPE_UDP;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, udpfd, &e);
+
+		d[i].type = FD_TYPE_CONTROL;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, controlfd, &e);
+
+		d[i].type = FD_TYPE_DAE;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
 	}
-	memset(ringbuffer, 0, sizeof(struct Tringbuffer));
-#endif
 
-	cli_session_kill = mmap(NULL, sizeof(sessionidt) * MAXSESSION, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (cli_session_kill == MAP_FAILED)
+#ifdef BGP
+	signal(SIGPIPE, SIG_IGN);
+	bgp_setup(config->as_number);
+	if (config->bind_address)
+		bgp_add_route(config->bind_address, 0xffffffff);
+
+	for (i = 0; i < BGP_NUM_PEERS; i++)
 	{
-		log(0, 0, 0, 0, "Error doing mmap for cli session kill: %s\n", strerror(errno));
-		exit(1);
+		if (config->neighbour[i].name[0])
+			bgp_start(&bgp_peers[i], config->neighbour[i].name,
+				config->neighbour[i].as, config->neighbour[i].keepalive,
+				config->neighbour[i].hold, 0); /* 0 = routing disabled */
 	}
-	memset(cli_session_kill, 0, sizeof(sessionidt) * MAXSESSION);
-	cli_tunnel_kill = mmap(NULL, sizeof(tunnelidt) * MAXSESSION, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (cli_tunnel_kill == MAP_FAILED)
+#endif /* BGP */
+
+	while (!main_quit || still_busy())
 	{
-		log(0, 0, 0, 0, "Error doing mmap for cli tunnel kill: %s\n", strerror(errno));
-		exit(1);
+		int more = 0;
+		int n;
+
+
+		if (main_reload)
+		{
+			main_reload = 0;
+			read_config_file();
+			config->reload_config++;
+		}
+
+		if (config->reload_config)
+		{
+			config->reload_config = 0;
+			update_config();
+		}
+
+#ifdef BGP
+		bgp_set_poll();
+#endif /* BGP */
+
+		n = epoll_wait(epollfd, events, maxevent, 100); // timeout 100ms (1/10th sec)
+		STAT(select_called);
+
+		TIME = now(NULL);
+		if (n < 0)
+		{
+			if (errno == EINTR ||
+			    errno == ECHILD) // EINTR was clobbered by sigchild_handler()
+				continue;
+
+			LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
+			break; // exit
+		}
+
+		if (n)
+		{
+			struct sockaddr_in addr;
+			socklen_t alen;
+			int c, s;
+			int udp_ready = 0;
+			int tun_ready = 0;
+			int cluster_ready = 0;
+			int udp_pkts = 0;
+			int tun_pkts = 0;
+			int cluster_pkts = 0;
+#ifdef BGP
+			uint32_t bgp_events[BGP_NUM_PEERS];
+			memset(bgp_events, 0, sizeof(bgp_events));
+#endif /* BGP */
+
+			for (c = n, i = 0; i < c; i++)
+			{
+				struct event_data *d = events[i].data.ptr;
+				switch (d->type)
+				{
+				case FD_TYPE_CLI: // CLI connections
+				{
+					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--;
+					break;
+				}
+
+				// these are handled below, with multiple interleaved reads
+				case FD_TYPE_CLUSTER:	cluster_ready++; break;
+				case FD_TYPE_TUN:	tun_ready++; break;
+				case FD_TYPE_UDP:	udp_ready++; break;
+
+				case FD_TYPE_CONTROL: // nsctl commands
+					alen = sizeof(addr);
+					processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+					n--;
+					break;
+
+				case FD_TYPE_DAE: // DAE requests
+					alen = sizeof(addr);
+					processdae(buf, recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+					n--;
+					break;
+
+				case FD_TYPE_RADIUS: // RADIUS response
+					s = recv(radfds[d->index], buf, sizeof(buf), 0);
+					if (s >= 0 && config->cluster_iam_master)
+						processrad(buf, s, d->index);
+
+					n--;
+					break;
+
+#ifdef BGP
+				case FD_TYPE_BGP:
+				    	bgp_events[d->index] = events[i].events;
+				    	n--;
+					break;
+#endif /* BGP */
+
+				default:
+				    	LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
+				}
+			}
+
+#ifdef BGP
+			bgp_process(bgp_events);
+#endif /* BGP */
+
+			for (c = 0; n && c < config->multi_read_count; c++)
+			{
+				// L2TP
+				if (udp_ready)
+				{
+					alen = sizeof(addr);
+					if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
+					{
+						processudp(buf, s, &addr);
+						udp_pkts++;
+					}
+					else
+					{
+						udp_ready = 0;
+						n--;
+					}
+				}
+
+				// incoming IP
+				if (tun_ready)
+				{
+					if ((s = read(tunfd, buf, sizeof(buf))) > 0)
+					{
+						processtun(buf, s);
+					    	tun_pkts++;
+					}
+					else
+					{
+						tun_ready = 0;
+						n--;
+					}
+				}
+
+				// cluster
+				if (cluster_ready)
+				{
+					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
+					{
+						cluster_ready = 0;
+						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);
+				more++;
+			}
+		}
+
+		if (time_changed)
+		{
+			double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
+
+			// Log current traffic stats
+			snprintf(config->bandwidth, sizeof(config->bandwidth),
+				"UDP-ETH:%1.0f/%1.0f  ETH-UDP:%1.0f/%1.0f  TOTAL:%0.1f   IN:%u OUT:%u",
+				(udp_rx / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
+				((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
+				udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
+		 
+			udp_tx = udp_rx = 0;
+			udp_rx_pkt = eth_rx_pkt = 0;
+			eth_tx = eth_rx = 0;
+			time_changed = 0;
+		 
+			if (config->dump_speed)
+				printf("%s\n", config->bandwidth);
+		 
+			// Update the internal time counter
+			strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
+		 
+			{
+				// Run timer hooks
+				struct param_timer p = { time_now };
+				run_plugins(PLUGIN_TIMER, &p);
+			}
+		}
+
+			// Runs on every machine (master and slaves).
+		if (next_cluster_ping <= TIME)
+		{
+			// Check to see which of the cluster is still alive..
+
+			cluster_send_ping(basetime);	// Only does anything if we're a slave
+			cluster_check_master();		// ditto.
+
+			cluster_heartbeat();		// Only does anything if we're a master.
+			cluster_check_slaves();		// ditto.
+
+			master_update_counts();		// If we're a slave, send our byte counters to our master.
+
+			if (config->cluster_iam_master && !config->cluster_iam_uptodate)
+				next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
+			else
+				next_cluster_ping = TIME + config->cluster_hb_interval;
+		}
+
+		if (!config->cluster_iam_master)
+			continue;
+
+			// Run token bucket filtering queue..
+			// Only run it every 1/10th of a second.
+		{
+			static clockt last_run = 0;
+			if (last_run != TIME)
+			{
+				last_run = TIME;
+				tbf_run_timer();
+			}
+		}
+
+			// Handle timeouts, retries etc.
+		{
+			static double last_clean = 0;
+			double this_clean;
+			double diff;
+
+			TIME = now(&this_clean);
+			diff = this_clean - last_clean;
+
+			// Run during idle time (after we've handled
+			// all incoming packets) or every 1/10th sec
+			if (!more || diff > 0.1)
+			{
+				regular_cleanups(diff);
+				last_clean = this_clean;
+			}
+		}
+
+		if (*config->accounting_dir)
+		{
+			static clockt next_acct = 0;
+			static clockt next_shut_acct = 0;
+
+			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);
+			}
+		}
 	}
-	memset(cli_tunnel_kill, 0, sizeof(tunnelidt) * MAXSESSION);
 
-	filter_buckets = mmap(NULL, sizeof(tbft) * MAXSESSION, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-	if (filter_buckets == MAP_FAILED)
+		// Are we the master and shutting down??
+	if (config->cluster_iam_master)
+		cluster_heartbeat(); // Flush any queued changes..
+
+		// Ok. Notify everyone we're shutting down. If we're
+		// the master, this will force an election.
+	cluster_send_ping(0);
+
+	//
+	// Important!!! We MUST not process any packets past this point!
+	LOG(1, 0, 0, "Shutdown complete\n");
+}
+
+static void stripdomain(char *host)
+{
+	char *p;
+
+	if ((p = strchr(host, '.')))
 	{
-		log(0, 0, 0, 0, "Error doing mmap for filter buckets: %s\n", strerror(errno));
-		exit(1);
-	}
-	memset(filter_buckets, 0, sizeof(tbft) * MAXSESSION);
+		char *domain = 0;
+		char _domain[1024];
 
-	memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
-	memset(session, 0, sizeof(sessiont) * MAXSESSION);
-	memset(radius, 0, sizeof(radiust) * MAXRADIUS);
-	memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
-	for (i = 1; i < MAXSESSION - 1; i++)
-		session[i].next = i + 1;
-	session[MAXSESSION - 1].next = 0;
-	sessionfree = 1;
-	if (!*hostname)
+		// strip off domain
+		FILE *resolv = fopen("/etc/resolv.conf", "r");
+		if (resolv)
+		{
+			char buf[1024];
+			char *b;
+
+			while (fgets(buf, sizeof(buf), resolv))
+			{
+				if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
+					continue;
+
+				if (!isspace(buf[6]))
+					continue;
+
+				b = buf + 7;
+				while (isspace(*b)) b++;
+
+				if (*b)
+				{
+					char *d = b;
+					while (*b && !isspace(*b)) b++;
+					*b = 0;
+					if (buf[0] == 'd') // domain is canonical
+					{
+						domain = d;
+						break;
+					}
+
+					// first search line
+					if (!domain)
+					{
+						// hold, may be subsequent domain line
+						strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
+						domain = _domain;
+					}
+				}
+			}
+
+			fclose(resolv);
+		}
+
+		if (domain)
+		{
+			int hl = strlen(host);
+			int dl = strlen(domain);
+			if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
+				host[hl -dl - 1] = 0;
+		}
+		else
+		{
+			*p = 0; // everything after first dot
+		}
+	}
+}
+
+// Init data structures
+static void initdata(int optdebug, char *optconfig)
+{
+	int i;
+
+	if (!(config = shared_malloc(sizeof(configt))))
+	{
+		fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
+		exit(1);
+	}
+
+	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
+	config->cluster_mcast_ttl = 1;
+ 	config->cluster_master_min_adv = 1;
+	config->ppp_restart_time = 3;
+	config->ppp_max_configure = 10;
+	config->ppp_max_failure = 5;
+	strcpy(config->random_device, RANDOMDEVICE);
+
+	log_stream = stderr;
+
+#ifdef RINGBUFFER
+	if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
+	{
+		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, "Error doing malloc for sessions: %s\n", strerror(errno));
+		exit(1);
+	}
+
+	if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
+	{
+		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, "Error doing malloc for radius: %s\n", strerror(errno));
+		exit(1);
+	}
+
+	if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
+	{
+		LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
+		exit(1);
+	}
+
+	if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
+	{
+		LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
+		exit(1);
+	}
+	memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
+
+	if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
+	{
+		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, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
+		exit(1);
+	}
+	memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
+
+	memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
+	memset(session, 0, sizeof(sessiont) * MAXSESSION);
+	memset(radius, 0, sizeof(radiust) * MAXRADIUS);
+	memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
+
+		// Put all the sessions on the free list marked as undefined.
+	for (i = 1; i < MAXSESSION; i++)
+	{
+		session[i].next = i + 1;
+		session[i].tunnel = T_UNDEF;	// mark it as not filled in.
+	}
+	session[MAXSESSION - 1].next = 0;
+	sessionfree = 1;
+
+		// Mark all the tunnels as undefined (waiting to be filled in by a download).
+	for (i = 1; i < MAXTUNNEL; i++)
+		tunnel[i].state = TUNNELUNDEF;	// mark it as not filled in.
+
+	if (!*hostname)
+	{
+		// Grab my hostname unless it's been specified
+		gethostname(hostname, sizeof(hostname));
+		stripdomain(hostname);
+	}
+
+	_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, "Error doing malloc for bgp: %s\n", strerror(errno));
+		exit(1);
+	}
+#endif /* BGP */
+}
+
+static int assign_ip_address(sessionidt s)
+{
+	uint32_t i;
+	int best = -1;
+	time_t best_time = time_now;
+	char *u = session[s].user;
+	char reuse = 0;
+
+
+	CSTAT(assign_ip_address);
+
+	for (i = 1; i < ip_pool_size; i++)
+	{
+		if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
+			continue;
+
+		if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
+		{
+			best = i;
+			reuse = 1;
+			break;
+		}
+
+		if (ip_address_pool[i].last < best_time)
+		{
+			best = i;
+			if (!(best_time = ip_address_pool[i].last))
+				break; // never used, grab this one
+		}
+	}
+
+	if (best < 0)
+	{
+		LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
+		return 0;
+	}
+
+	session[s].ip = ip_address_pool[best].address;
+	session[s].ip_pool_index = best;
+	ip_address_pool[best].assigned = 1;
+	ip_address_pool[best].last = time_now;
+	ip_address_pool[best].session = s;
+	if (session[s].walled_garden)
+		/* Don't track addresses of users in walled garden (note: this
+		   means that their address isn't "sticky" even if they get
+		   un-gardened). */
+		ip_address_pool[best].user[0] = 0;
+	else
+		strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
+
+	STAT(ip_allocated);
+	LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
+		reuse ? "Reusing" : "Allocating", best);
+
+	return 1;
+}
+
+static void free_ip_address(sessionidt s)
+{
+	int i = session[s].ip_pool_index;
+
+
+	CSTAT(free_ip_address);
+
+	if (!session[s].ip)
+		return; // what the?
+
+	if (i < 0)	// Is this actually part of the ip pool?
+		i = 0;
+
+	STAT(ip_freed);
+	cache_ipmap(session[s].ip, -i);	// Change the mapping to point back to the ip pool index.
+	session[s].ip = 0;
+	ip_address_pool[i].assigned = 0;
+	ip_address_pool[i].session = 0;
+	ip_address_pool[i].last = time_now;
+}
+
+//
+// Fsck the address pool against the session table.
+// Normally only called when we become a master.
+//
+// This isn't perfect: We aren't keep tracking of which
+// users used to have an IP address.
+//
+void rebuild_address_pool(void)
+{
+	int i;
+
+		//
+		// Zero the IP pool allocation, and build
+		// a map from IP address to pool index.
+	for (i = 1; i < MAXIPPOOL; ++i)
+	{
+		ip_address_pool[i].assigned = 0;
+		ip_address_pool[i].session = 0;
+		if (!ip_address_pool[i].address)
+			continue;
+
+		cache_ipmap(ip_address_pool[i].address, -i);	// Map pool IP to pool index.
+	}
+
+	for (i = 0; i < MAXSESSION; ++i)
+	{
+		int ipid;
+		if (!(session[i].opened && session[i].ip))
+			continue;
+
+		ipid = - lookup_ipmap(htonl(session[i].ip));
+
+		if (session[i].ip_pool_index < 0)
+		{
+			// Not allocated out of the pool.
+			if (ipid < 1)			// Not found in the pool either? good.
+				continue;
+
+			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.
+		}
+
+
+		if (ipid > MAXIPPOOL || ipid < 0)
+		{
+			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;
+		}
+
+		ip_address_pool[ipid].assigned = 1;
+		ip_address_pool[ipid].session = i;
+		ip_address_pool[ipid].last = time_now;
+		strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
+		session[i].ip_pool_index = ipid;
+		cache_ipmap(session[i].ip, i);	// Fix the ip map.
+	}
+}
+
+//
+// Fix the address pool to match a changed session.
+// (usually when the master sends us an update).
+static void fix_address_pool(int sid)
+{
+	int ipid;
+
+	ipid = session[sid].ip_pool_index;
+
+	if (ipid > ip_pool_size)
+		return;		// Ignore it. rebuild_address_pool will fix it up.
+
+	if (ip_address_pool[ipid].address != session[sid].ip)
+		return;		// Just ignore it. rebuild_address_pool will take care of it.
+
+	ip_address_pool[ipid].assigned = 1;
+	ip_address_pool[ipid].session = sid;
+	ip_address_pool[ipid].last = time_now;
+	strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
+}
+
+//
+// Add a block of addresses to the IP pool to hand out.
+//
+static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
+{
+	int i;
+	if (mask == 0)
+		mask = 0xffffffff;	// Host route only.
+
+	addr &= mask;
+
+	if (ip_pool_size >= MAXIPPOOL)	// Pool is full!
+		return ;
+
+	for (i = addr ;(i & mask) == addr; ++i)
+	{
+		if ((i & 0xff) == 0 || (i&0xff) == 255)
+			continue;	// Skip 0 and broadcast addresses.
+
+		ip_address_pool[ip_pool_size].address = i;
+		ip_address_pool[ip_pool_size].assigned = 0;
+		++ip_pool_size;
+		if (ip_pool_size >= MAXIPPOOL)
+		{
+			LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
+			return;
+		}
+	}
+}
+
+// Initialize the IP address pool
+static void initippool()
+{
+	FILE *f;
+	char *p;
+	char buf[4096];
+	memset(ip_address_pool, 0, sizeof(ip_address_pool));
+
+	if (!(f = fopen(IPPOOLFILE, "r")))
+	{
+		LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
+		exit(1);
+	}
+
+	while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
+	{
+		char *pool = buf;
+		buf[4095] = 0;	// Force it to be zero terminated/
+
+		if (*buf == '#' || *buf == '\n')
+			continue; // Skip comments / blank lines
+		if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
+		if ((p = (char *)strchr(buf, ':')))
+		{
+			in_addr_t src;
+			*p = '\0';
+			src = inet_addr(buf);
+			if (src == INADDR_NONE)
+			{
+				LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
+				exit(1);
+			}
+			// This entry is for a specific IP only
+			if (src != config->bind_address)
+				continue;
+			*p = ':';
+			pool = p+1;
+		}
+		if ((p = (char *)strchr(pool, '/')))
+		{
+			// It's a range
+			int numbits = 0;
+			in_addr_t start = 0, mask = 0;
+
+			LOG(2, 0, 0, "Adding IP address range %s\n", buf);
+			*p++ = 0;
+			if (!*p || !(numbits = atoi(p)))
+			{
+				LOG(0, 0, 0, "Invalid pool range %s\n", buf);
+				continue;
+			}
+			start = ntohl(inet_addr(pool));
+			mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
+
+			// Add a static route for this pool
+			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);
+		}
+		else
+		{
+			// It's a single ip address
+			add_to_ip_pool(inet_addr(pool), 0);
+		}
+	}
+	fclose(f);
+	LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
+}
+
+void snoop_send_packet(uint8_t *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)
+		return;
+
+	snoop_addr.sin_family = AF_INET;
+	snoop_addr.sin_addr.s_addr = destination;
+	snoop_addr.sin_port = ntohs(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, "Error sending intercept packet: %s\n", strerror(errno));
+
+	STAT(packets_snooped);
+}
+
+static int dump_session(FILE **f, sessiont *s)
+{
+	if (!s->opened || !s->ip || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
+		return 1;
+
+	if (!*f)
+	{
+		char filename[1024];
+		char timestr[64];
+		time_t now = time(NULL);
+
+		strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
+		snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
+
+		if (!(*f = fopen(filename, "w")))
+		{
+			LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
+			return 0;
+		}
+
+		LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
+		fprintf(*f, "# dslwatch.pl dump file V1.01\n"
+			"# host: %s\n"
+			"# endpoint: %s\n"
+			"# time: %ld\n"
+			"# uptime: %ld\n"
+			"# format: username ip qos uptxoctets downrxoctets\n",
+			hostname,
+			fmtaddr(config->bind_address ? config->bind_address : my_address, 0),
+			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_delta,				// uptxoctets
+		(uint32_t) s->cout_delta);				// downrxoctets
+
+	s->cin_delta = s->cout_delta = 0;
+
+	return 1;
+}
+
+static void dump_acct_info(int all)
+{
+	int i;
+	FILE *f = NULL;
+
+
+	CSTAT(dump_acct_info);
+
+	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);
+}
+
+// Main program
+int main(int argc, char *argv[])
+{
+	int i;
+	int optdebug = 0;
+	char *optconfig = CONFIGFILE;
+
+	time(&basetime);             // start clock
+
+	// scan args
+	while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
+	{
+		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\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;
+		}
+	}
+
+	// Start the timer routine off
+	time(&time_now);
+	strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
+
+	initplugins();
+	initdata(optdebug, optconfig);
+
+	init_cli(hostname);
+	read_config_file();
+	update_config();
+	init_tbf(config->num_tbfs);
+
+	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, "Can't set ulimit: %s\n", strerror(errno));
+
+		// Make core dumps go to /tmp
+		chdir("/tmp");
+	}
+
+	if (config->scheduler_fifo)
+	{
+		int ret;
+		struct sched_param params = {0};
+		params.sched_priority = 1;
+
+		if (get_nprocs() < 2)
+		{
+			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, "Using FIFO scheduler.  Say goodbye to any other processes running\n");
+			}
+			else
+			{
+				LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
+				config->scheduler_fifo = 0;
+			}
+		}
+	}
+
+	/* Set up the cluster communications port. */
+	if (cluster_init() < 0)
+		exit(1);
+
+	inittun();
+	LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
+
+	initudp();
+	initrad();
+	initippool();
+
+	// seed prng
+	{
+		unsigned seed = time_now ^ getpid();
+		LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
+		srand(seed);
+	}
+
+	signal(SIGHUP,  sighup_handler);
+	signal(SIGCHLD, sigchild_handler);
+	signal(SIGTERM, shutdown_handler);
+	signal(SIGINT,  shutdown_handler);
+	signal(SIGQUIT, shutdown_handler);
+
+	// Prevent us from getting paged out
+	if (config->lock_pages)
+	{
+		if (!mlockall(MCL_CURRENT))
+			LOG(1, 0, 0, "Locking pages into memory\n");
+		else
+			LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
+	}
+
+	// Drop privileges here
+	if (config->target_uid > 0 && geteuid() == 0)
+		setuid(config->target_uid);
+
+	mainloop();
+
+	/* remove plugins (so cleanup code gets run) */
+	plugins_done();
+
+	// Remove the PID file if we wrote it
+	if (config->wrote_pid && *config->pid_file == '/')
+		unlink(config->pid_file);
+
+	/* kill CLI children */
+	signal(SIGTERM, SIG_IGN);
+	kill(0, SIGTERM);
+	return 0;
+}
+
+static void sighup_handler(int sig)
+{
+	main_reload++;
+}
+
+static void shutdown_handler(int sig)
+{
+	main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
+}
+
+static void sigchild_handler(int sig)
+{
+	while (waitpid(-1, NULL, WNOHANG) > 0)
+	    ;
+}
+
+static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response)
+{
+	MD5_CTX ctx;
+	*challenge_response = NULL;
+
+	if (!*config->l2tp_secret)
+	{
+		LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
+		return;
+	}
+
+	LOG(4, 0, 0, "   Building challenge response for CHAP request\n");
+
+	*challenge_response = calloc(17, 1);
+
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, &id, 1);
+	MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
+	MD5_Update(&ctx, challenge, challenge_length);
+	MD5_Final(*challenge_response, &ctx);
+
+	return;
+}
+
+static int facility_value(char *name)
+{
+	int i;
+	for (i = 0; facilitynames[i].c_name; i++)
+	{
+		if (strcmp(facilitynames[i].c_name, name) == 0)
+			return facilitynames[i].c_val;
+	}
+	return 0;
+}
+
+static void update_config()
+{
+	int i;
+	char *p;
+	static int timeout = 0;
+	static int interval = 0;
+
+	// Update logging
+	closelog();
+	syslog_log = 0;
+	if (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)
+		{
+			char *p = config->log_filename + 7;
+			if (*p)
+			{
+				openlog("l2tpns", LOG_PID, facility_value(p));
+				syslog_log = 1;
+			}
+		}
+		else if (strchr(config->log_filename, '/') == config->log_filename)
+		{
+			if ((log_stream = fopen((char *)(config->log_filename), "a")))
+			{
+				fseek(log_stream, 0, SEEK_END);
+				setbuf(log_stream, NULL);
+			}
+			else
+			{
+				log_stream = stderr;
+				setbuf(log_stream, NULL);
+			}
+		}
+	}
+	else
+	{
+		log_stream = stderr;
+		setbuf(log_stream, NULL);
+	}
+
+#define L2TP_HDRS		(20+8+6+4)	// L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
+#define TCP_HDRS		(20+20)		// TCP encapsulation: ip + tcp
+
+	if (config->l2tp_mtu <= 0)		config->l2tp_mtu = PPPMTU;
+	else if (config->l2tp_mtu < MINMTU)	config->l2tp_mtu = MINMTU;
+	else if (config->l2tp_mtu > MAXMTU)	config->l2tp_mtu = MAXMTU;
+
+	// reset MRU/MSS globals
+	MRU = config->l2tp_mtu - L2TP_HDRS;
+	MSS = MRU - TCP_HDRS;
+
+	// Update radius
+	config->numradiusservers = 0;
+	for (i = 0; i < MAXRADSERVER; i++)
+		if (config->radiusserver[i])
+		{
+			config->numradiusservers++;
+			// Set radius port: if not set, take the port from the
+			// first radius server.  For the first radius server,
+			// take the #defined default value from l2tpns.h
+
+			// 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])
+				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");
+
+	// 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
+	{
+		strcpy(config->radius_authtypes_s, "chap");
+		if (config->radius_authtypes & AUTHPAP)
+			strcat(config->radius_authtypes_s, ", pap");
+	}
+
+	if (!config->radius_dae_port)
+		config->radius_dae_port = DAEPORT;
+
+	// re-initialise the random number source
+	initrandom(config->random_device);
+
+	// Update plugins
+	for (i = 0; i < MAXPLUGINS; i++)
+	{
+		if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
+			continue;
+
+		if (*config->plugins[i])
+		{
+			// Plugin added
+			add_plugin(config->plugins[i]);
+		}
+		else if (*config->old_plugins[i])
+		{
+			// Plugin removed
+			remove_plugin(config->old_plugins[i]);
+		}
+	}
+
+	memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
+	if (!config->multi_read_count) config->multi_read_count = 10;
+	if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
+	if (!*config->cluster_interface)
+		strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
+
+	if (!config->cluster_hb_interval)
+		config->cluster_hb_interval = PING_INTERVAL;	// Heartbeat every 0.5 seconds.
+
+	if (!config->cluster_hb_timeout)
+		config->cluster_hb_timeout = HB_TIMEOUT;	// 10 missed heartbeat triggers an election.
+
+	if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
+	{
+		// Paranoia:  cluster_check_master() treats 2 x interval + 1 sec as
+		// late, ensure we're sufficiently larger than that
+		int t = 4 * config->cluster_hb_interval + 11;
+
+		if (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;
+		}
+
+		// Push timing changes to the slaves immediately if we're the master
+		if (config->cluster_iam_master)
+			cluster_heartbeat();
+
+		interval = config->cluster_hb_interval;
+		timeout = config->cluster_hb_timeout;
+	}
+
+	// Write PID file
+	if (*config->pid_file == '/' && !config->wrote_pid)
+	{
+		FILE *f;
+		if ((f = fopen(config->pid_file, "w")))
+		{
+			fprintf(f, "%d\n", getpid());
+			fclose(f);
+			config->wrote_pid = 1;
+		}
+		else
+		{
+			LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
+		}
+	}
+}
+
+static void read_config_file()
+{
+	FILE *f;
+
+	if (!config->config_file) return;
+	if (!(f = fopen(config->config_file, "r")))
+	{
+		fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
+		return;
+	}
+
+	LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
+	cli_do_file(f);
+	LOG(3, 0, 0, "Done reading config file\n");
+	fclose(f);
+}
+
+int sessionsetup(sessionidt s, tunnelidt t)
+{
+	// A session now exists, set it up
+	in_addr_t ip;
+	char *user;
+	sessionidt i;
+	int r;
+
+	CSTAT(sessionsetup);
+
+	LOG(3, s, t, "Doing session setup for session\n");
+
+	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.", 2, 7); // try another
+			return 0;
+		}
+		LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
+			fmtaddr(htonl(session[s].ip), 0));
+	}
+
+
+	// Make sure this is right
+	session[s].tunnel = t;
+
+	// zap old sessions with same IP and/or username
+	// Don't kill gardened sessions - doing so leads to a DoS
+	// from someone who doesn't need to know the password
 	{
-		char *p;
-		// Grab my hostname unless it's been specified
-		gethostname(hostname, sizeof(hostname));
+		ip = session[s].ip;
+		user = session[s].user;
+		for (i = 1; i <= config->cluster_highest_sessionid; i++)
 		{
-			struct hostent *h = gethostbyname(hostname);
-			if (h)
-				myip = ntohl(*(u32 *) h->h_addr);
-		}
+			if (i == s) continue;
+			if (!session[s].opened) continue;
+			if (ip == session[i].ip)
+			{
+				sessionkill(i, "Duplicate IP address");
+				continue;
+			}
 
-		if ((p = strstr(hostname, ".optusnet.com.au"))) *p = 0;
+			if (config->allow_duplicate_users) continue;
+			if (session[s].walled_garden || session[i].walled_garden) continue;
+			if (!strcasecmp(user, session[i].user))
+				sessionkill(i, "Duplicate session for users");
+		}
 	}
-	_statistics->start_time = _statistics->last_reset = time(NULL);
-}
-
-void initiptables(void)
-{
-	/* Flush the tables here so that we have a clean slate */
-	system("iptables -t nat -F l2tpns");
-	system("iptables -t mangle -F l2tpns");
-}
-
-int assign_ip_address(sessionidt s)
-{
-	unsigned i;
-	int best = -1;
-	clockt best_time = time_now;
-	char *u = session[s].user;
-	char reuse = 0;
 
-#ifdef STAT_CALLS
-	STAT(call_assign_ip_address);
-#endif
-	for (i = 0; i < ip_pool_size; i++)
 	{
-		if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
-			continue;
+	    	int routed = 0;
 
-		if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
+		// Add the route for this session.
+		for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
 		{
-			best = i;
-			reuse = 1;
-			break;
+			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);
 		}
 
-		if (ip_address_pool[i].last < best_time)
+		// 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
 		{
-			best = i;
-			if (!(best_time = ip_address_pool[i].last))
-				break; // never used, grab this one
+			if (!routed) routeset(s, session[s].ip, 0, 0, 1);
 		}
+		else
+			cache_ipmap(session[s].ip, s);
 	}
 
-	if (best < 0)
+	sess_local[s].lcp_authtype = 0; // RADIUS authentication complete
+	lcp_open(s, t); // transition to Network phase and send initial IPCP
+
+	// Run the plugin's against this new session.
 	{
-		log(0, 0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
-		return 0;
+		struct param_new_session data = { &tunnel[t], &session[s] };
+		run_plugins(PLUGIN_NEW_SESSION, &data);
 	}
 
-	session[s].ip = ntohl(ip_address_pool[best].address);
-	session[s].ip_pool_index = best;
-	ip_address_pool[best].assigned = 1;
-	ip_address_pool[best].last = time_now;
-	ip_address_pool[best].session = s;
-	if (session[s].walled_garden)
-		/* Don't track addresses of users in walled garden (note: this
-		   means that their address isn't "sticky" even if they get
-		   un-gardened). */
-		ip_address_pool[best].user[0] = 0;
-	else
-		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);
-
-	return 1;
-}
+	// Allocate TBFs if throttled
+	if (session[s].throttle_in || session[s].throttle_out)
+		throttle_session(s, session[s].throttle_in, session[s].throttle_out);
 
-void free_ip_address(sessionidt s)
-{
-	int i = session[s].ip_pool_index;
+	session[s].last_packet = time_now;
 
-#ifdef STAT_CALLS
-	STAT(call_free_ip_address);
-#endif
+	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);
 
-	if (!session[s].ip)
-		return; // what the?
+	cluster_send_session(s);	// Mark it as dirty, and needing to the flooded to the cluster.
 
-	STAT(ip_freed);
-	uncache_sessionid(session[s].ip);
-	session[s].ip = 0;
-	ip_address_pool[i].assigned = 0;
-	ip_address_pool[i].session = 0;
-	ip_address_pool[i].last = time_now;
+	return 1;       // RADIUS OK and IP allocated, done...
 }
 
-// Initialize the IP address pool
-void initippool()
+//
+// This session just got dropped on us by the master or something.
+// Make sure our tables up up to date...
+//
+int load_session(sessionidt s, sessiont *new)
 {
-	FILE *f;
-	char *buf, *p;
-	int pi = 0;
-	memset(ip_address_pool, 0, sizeof(ip_address_pool));
+	int i;
+	int newip = 0;
 
-	if (!(f = fopen(IPPOOLFILE, "r")))
+		// Sanity checks.
+	if (new->ip_pool_index >= MAXIPPOOL ||
+		new->tunnel >= MAXTUNNEL)
 	{
-		log(0, 0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
-		exit(-1);
+		LOG(0, s, 0, "Strange session update received!\n");
+			// FIXME! What to do here?
+		return 0;
 	}
 
-	buf = (char *)malloc(4096);
+		//
+		// Ok. All sanity checks passed. Now we're committed to
+		// loading the new session.
+		//
 
-	while (pi < MAXIPPOOL && fgets(buf, 4096, f))
+	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++;
+
+	// needs update
+	if (newip)
 	{
-		char* pool = buf;
-		if (*buf == '#' || *buf == '\n')
-			continue; // Skip comments / blank lines
-		if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
-		if ((p = (char *)strchr(buf, ':')))
-		{
-			ipt src;
-			*p = '\0';
-			src = inet_addr(buf);
-			if (src == INADDR_NONE)
-			{
-				log(0, 0, 0, 0, "Invalid address pool IP %s", buf);
-				exit(-1);
-			}
-			// This entry is for a specific IP only
-			if (src != config->bind_address)
-				continue;
-			*p = ':';
-			pool = p+1;
-		}
-		if ((p = (char *)strchr(pool, '/')))
+	    	int routed = 0;
+
+		// remove old routes...
+		for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
 		{
-			// It's a range
-			int numbits = 0;
-			unsigned long start = 0, end = 0, mask = 0, ip;
-			struct rtentry r;
+			if ((session[s].ip & session[s].route[i].mask) ==
+			    (session[s].route[i].ip & session[s].route[i].mask))
+				routed++;
 
-			log(2, 0, 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);
-				continue;
-			}
-			start = end = ntohl(inet_addr(pool));
-			mask = (unsigned long)(pow(2, numbits) - 1) << (32 - numbits);
-			start &= mask;
-			end = start + (int)(pow(2, (32 - numbits))) - 1;
-			for (ip = (start + 1); ip < end && pi < MAXIPPOOL; ip++)
-			{
-				if ((ip & 0xFF) == 0 || (ip & 0xFF) == 255)
-					continue;
-				ip_address_pool[pi++].address = htonl(ip);
-			}
+			routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
+		}
 
-			// Add a static route for this pool
-			log(5, 0, 0, 0, "Adding route for address pool %s/%lu\n", inet_toa(htonl(start)), 32 + mask);
-			memset(&r, 0, sizeof(r));
-			r.rt_dev = config->tapdevice;
-			r.rt_dst.sa_family = AF_INET;
-			*(u32 *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(start);
-			r.rt_genmask.sa_family = AF_INET;
-			*(u32 *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
-			r.rt_flags = (RTF_UP | RTF_STATIC);
-			if (ioctl(ifrfd, SIOCADDRT, (void *) &r) < 0)
+		// ...ip
+		if (session[s].ip)
+		{
+			if (session[s].ip_pool_index == -1) // static IP
 			{
-				log(0, 0, 0, 0, "Error adding ip address pool route %s/%lu: %s\n",
-					inet_toa(start), mask, strerror(errno));
+				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);
 		}
-		else
-		{
-			// It's a single ip address
-			ip_address_pool[pi++].address = inet_addr(pool);
-		}
-	}
-
-	free(buf);
-	fclose(f);
-	log(1, 0, 0, 0, "IP address pool is %d addresses\n", pi);
-	ip_pool_size = pi;
-}
-
-void snoop_send_packet(char *packet, u16 size)
-{
-	if (!snoop_addr.sin_port || snoopfd <= 0 || size <= 0 || !packet)
-		return;
-
-	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));
-	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));
-	STAT(packets_snooped);
-}
-
-void dump_acct_info()
-{
-    char filename[1024];
-    char timestr[64];
-    time_t t = time(NULL);
-    int i;
-    FILE *f = NULL;
 
-#ifdef STAT_CALLS
-	STAT(call_dump_acct_info);
-#endif
-    strftime(timestr, 64, "%Y%m%d%H%M%S", localtime(&t));
-    snprintf(filename, 1024, "%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)
-	{
-	    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(4, 0, 0, 0, "Dumping accounting information for %s\n", session[i].user);
-	fprintf(f, "%s %s %d %lu %lu\n",
-	    session[i].user,				// username
-	    inet_toa(htonl(session[i].ip)),		// ip
-	    (session[i].throttle) ? 2 : 1,		// qos
-	    (unsigned long)session[i].cin,		// uptxoctets
-	    (unsigned long)session[i].cout);		// downrxoctets
-
-	session[i].pin = session[i].cin = 0;
-	session[i].pout = session[i].cout = 0;
-    }
-
-    if (f) fclose(f);
-}
-
-// Main program
-int main(int argc, char *argv[])
-{
-	int o;
+		routed = 0;
 
-	_program_name = strdup(argv[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++;
 
-	time(&basetime);             // start clock
-	// scan args
+			routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
+		}
 
-	while ((o = getopt(argc, argv, "vc:h:a:d")) >= 0)
-	{
-		switch (o)
+		// ...ip
+		if (new->ip)
 		{
-			case 'd':
-				// Double fork to detach from terminal
-				if (fork()) exit(0);
-				if (fork()) exit(0);
-				break;
-			case 'v':
-				config->debug++;
-				break;
-			case 'h':
-				strncpy(hostname, optarg, 999);
-				break;
-			case '?':
-			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;
+			// If there's a new one, add it.
+			if (new->ip_pool_index == -1)
+			{
+				if (!routed) routeset(s, new->ip, 0, 0, 1);
+			}
+			else
+				cache_ipmap(new->ip, s);
 		}
 	}
 
-	// Start the timer routine off
-	time(&time_now);
-	strftime(time_now_string, 64, "%Y-%m-%d %H:%M:%S", localtime(&time_now));
-	signal(SIGALRM, sigalrm_handler);
-	siginterrupt(SIGALRM, 0);
+	// check v6 routing
+	if (new->ipv6prefixlen && new->ppp.ipv6cp == Opened && session[s].ppp.ipv6cp != Opened)
+		    route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
 
-	initiptables();
-	initplugins();
-	initdata();
-	init_cli();
-	read_config_file();
-	log(0, 0, 0, 0, "$Id: l2tpns.c,v 1.7 2004/05/24 04:42:50 fred_nerk Exp $\n(c) Copyright 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
+	// check filters
+	if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
 	{
-		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));
-		// Make core dumps go to /tmp
-		chdir("/tmp");
+		LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
+		new->filter_in = 0;
 	}
 
-	/* Start up the cluster first, so that we don't have two machines with
-	 * the same IP at once.
-	 * This is still racy, but the second GARP should fix that
-	 */
-	cluster_init(config->bind_address, 0);
-	cluster_send_message(config->cluster_address, config->bind_address, C_HELLO, hostname, strlen(hostname));
-
-	inittap();
-	log(1, 0, 0, 0, "Set up on interface %s\n", config->tapdevice);
-
-	initudp();
-	initrad();
-	initippool();
-	init_rl();
-	if (config->bind_address)
-		send_garp(config->bind_address);
+	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 NOSTATEFILE exists, we will ignore any updates from the cluster master for this execution
-	if (!unlink(NOSTATEFILE))
-	    config->ignore_cluster_updates = 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++;
+	}
 
-	read_state();
+	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++;
+	}
 
-	signal(SIGHUP, sighup_handler);
-	signal(SIGTERM, sigterm_handler);
-	signal(SIGINT, sigterm_handler);
-	signal(SIGQUIT, sigquit_handler);
-	signal(SIGCHLD, sigchild_handler);
+	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;
 
-	alarm(1);
+	memcpy(&session[s], new, sizeof(session[s]));	// Copy over..
 
-	// Drop privileges here
-	if (config->target_uid > 0 && geteuid() == 0)
-		setuid(config->target_uid);
+		// Do fixups into address pool.
+	if (new->ip_pool_index != -1)
+		fix_address_pool(s);
 
-	mainloop();
-	return 0;
+	return 1;
 }
 
-void sighup_handler(int junk)
+static void initplugins()
 {
-	if (log_stream && log_stream != stderr)
-	{
-		fclose(log_stream);
-		log_stream = NULL;
-	}
+	int i;
 
-	read_config_file();
+	loaded_plugins = ll_init();
+	// Initialize the plugins to nothing
+	for (i = 0; i < MAX_PLUGIN_TYPES; i++)
+		plugins[i] = ll_init();
 }
 
-void sigalrm_handler(int junk)
+static void *open_plugin(char *plugin_name, int load)
 {
-	// Log current traffic stats
+	char path[256] = "";
 
-	snprintf(config->bandwidth, sizeof(config->bandwidth),
-		"UDP-ETH:%1.0f/%1.0f  ETH-UDP:%1.0f/%1.0f  TOTAL:%0.1f   IN:%lu OUT:%lu",
-		(udp_rx / 1024.0 / 1024.0 * 8),
-		(eth_tx / 1024.0 / 1024.0 * 8),
-		(eth_rx / 1024.0 / 1024.0 * 8),
-		(udp_tx / 1024.0 / 1024.0 * 8),
-		((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
-		udp_rx_pkt, eth_rx_pkt);
+	snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
+	LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
+	return dlopen(path, RTLD_NOW);
+}
 
-	udp_tx = udp_rx = 0;
-	udp_rx_pkt = eth_rx_pkt = 0;
-	eth_tx = eth_rx = 0;
+// plugin callback to get a config value
+static void *getconfig(char *key, enum config_typet type)
+{
+	int i;
 
-	if (config->dump_speed)
-		printf("%s\n", config->bandwidth);
+	for (i = 0; config_values[i].key; i++)
+	{
+		if (!strcmp(config_values[i].key, key))
+		{
+			if (config_values[i].type == type)
+				return ((void *) config) + config_values[i].offset;
 
-	// Update the internal time counter
-	time(&time_now);
-	strftime(time_now_string, 64, "%Y-%m-%d %H:%M:%S", localtime(&time_now));
-	alarm(1);
+			LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
+				key, type, config_values[i].type);
 
-	{
-		// Run timer hooks
-		struct param_timer p = { time_now };
-		run_plugins(PLUGIN_TIMER, &p);
+			return 0;
+		}
 	}
 
+	LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
+	return 0;
 }
 
-void sigterm_handler(int junk)
-{
-	log(1, 0, 0, 0, "Shutting down cleanly\n");
-	if (config->save_state)
-		dump_state();
-	main_quit++;
-}
-
-void sigquit_handler(int junk)
+static int add_plugin(char *plugin_name)
 {
-	FILE *f;
+	static struct pluginfuncs funcs = {
+		_log,
+		_log_hex,
+		fmtaddr,
+		sessionbyuser,
+		sessiontbysessionidt,
+		sessionidtbysessiont,
+		radiusnew,
+		radiussend,
+		getconfig,
+		sessionshutdown,
+		sessionkill,
+		throttle_session,
+		cluster_send_session,
+	};
+
+	void *p = open_plugin(plugin_name, 1);
+	int (*initfunc)(struct pluginfuncs *);
 	int i;
 
-	log(1, 0, 0, 0, "Shutting down without saving sessions\n");
-	for (i = 1; i < MAXSESSION; i++)
+	if (!p)
 	{
-		if (session[i].opened)
-			sessionkill(i, "L2TPNS Closing");
+		LOG(1, 0, 0, "   Plugin load failed: %s\n", dlerror());
+		return -1;
 	}
-	for (i = 1; i < MAXTUNNEL; i++)
+
+	if (ll_contains(loaded_plugins, p))
+	{
+		dlclose(p);
+		return 0; // already loaded
+	}
+
+	{
+		int *v = dlsym(p, "plugin_api_version");
+		if (!v || *v != PLUGIN_API_VERSION)
+		{
+			LOG(1, 0, 0, "   Plugin load failed: API version mismatch: %s\n", dlerror());
+			dlclose(p);
+			return -1;
+		}
+	}
+
+	if ((initfunc = dlsym(p, "plugin_init")))
 	{
-		if (tunnel[i].ip || tunnel[i].state)
-			tunnelshutdown(i, "L2TPNS Closing");
+		if (!initfunc(&funcs))
+		{
+			LOG(1, 0, 0, "   Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
+			dlclose(p);
+			return -1;
+		}
 	}
 
-	cluster_send_goodbye();
+	ll_push(loaded_plugins, p);
 
-	// Touch a file which says not to reload the state
-	f = fopen(NOSTATEFILE, "w");
-	if (f) fclose(f);
+	for (i = 0; i < max_plugin_functions; i++)
+	{
+		void *x;
+		if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
+		{
+			LOG(3, 0, 0, "   Supports function \"%s\"\n", plugin_functions[i]);
+			ll_push(plugins[i], x);
+		}
+	}
 
-	main_quit++;
+	LOG(2, 0, 0, "   Loaded plugin %s\n", plugin_name);
+	return 1;
 }
 
-void sigchild_handler(int signal)
+static void run_plugin_done(void *plugin)
 {
-	while (waitpid(-1, NULL, WNOHANG) > 0)
-	    ;
+	int (*donefunc)(void) = dlsym(plugin, "plugin_done");
+
+	if (donefunc)
+		donefunc();
 }
 
-void read_state()
+static int remove_plugin(char *plugin_name)
 {
-    struct stat sb;
-    int i;
-    ippoolt itmp;
-    FILE *f;
-    char magic[sizeof(DUMP_MAGIC)-1];
-    u32 buf[2];
-
-    if (!config->save_state)
-	return;
+	void *p = open_plugin(plugin_name, 0);
+	int loaded = 0;
 
-    // Ignore saved state if NOSTATEFILE exists
-    if (config->ignore_cluster_updates)
-    {
-	unlink(STATEFILE);
-	return;
-    }
+	if (!p)
+		return -1;
 
-    if (stat(STATEFILE, &sb) < 0)
-	return;
+	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);
+		}
 
-    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 (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)
-	{
-	    log(0, 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, 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 = 0;
-	if (session[i].opened)
-	{
-	    log(2, 0, i, 0, "Loaded active session for user %s\n", session[i].user);
-	    if (session[i].ip && session[i].ip != 0xFFFFFFFE)
-		sessionsetup(session[i].tunnel, i, 0);
-	}
-    }
-
-    fclose(f);
-    log(0, 0, 0, 0, "Loaded saved state information\n");
-}
-
-void dump_state()
-{
-    FILE *f;
-    u32 buf[2];
-
-    if (!config->save_state)
-	return;
+		ll_delete(loaded_plugins, p);
+		run_plugin_done(p);
+		loaded = 1;
+	}
 
-    do {
-	if (!(f = fopen(STATEFILE, "w")))
-	    break;
+	dlclose(p);
+	LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
+	return loaded;
+}
 
-	log(1, 0, 0, 0, "Dumping state information\n");
+int run_plugins(int plugin_type, void *data)
+{
+	int (*func)(void *data);
 
-	if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC)-1, 1, f) != 1) break;
+	if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
+		return PLUGIN_RET_ERROR;
 
-	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;
+	ll_reset(plugins[plugin_type]);
+	while ((func = ll_next(plugins[plugin_type])))
+	{
+		int r = func(data);
 
-	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;
+		if (r != PLUGIN_RET_OK)
+			return r; // stop here
+	}
 
-	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;
+	return PLUGIN_RET_OK;
+}
 
-	if (fclose(f) == 0) return; // OK
-    } while (0);
+static void plugins_done()
+{
+	void *p;
 
-    log(0, 0, 0, 0, "Can't write state information: %s\n", strerror(errno));
-    unlink(STATEFILE);
+	ll_reset(loaded_plugins);
+	while ((p = ll_next(loaded_plugins)))
+		run_plugin_done(p);
 }
 
-void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response)
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen)
 {
-	MD5_CTX ctx;
-	*challenge_response = NULL;
+	struct nsctl request;
+	struct nsctl response;
+	int type = unpack_control(&request, buf, len);
+	int r;
+	void *p;
 
-	if (!*config->l2tpsecret)
+	if (log_stream && config->debug >= 4)
 	{
-		log(0, 0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
-		return;
+		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);
+		}
 	}
 
-	log(4, 0, 0, 0, "   Building challenge response for CHAP request\n");
+	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;
+		}
 
-	*challenge_response = (char *)calloc(17, 1);
+		break;
 
-	MD5Init(&ctx);
-	MD5Update(&ctx, &id, 1);
-	MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-	MD5Update(&ctx, challenge, challenge_length);
-	MD5Final(*challenge_response, &ctx);
+	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;
+		}
 
-	return;
-}
+		break;
 
-static int facility_value(char *name)
-{
-    int i;
-    for (i = 0; facilitynames[i].c_name; i++)
-    {
-	if (strcmp(facilitynames[i].c_name, name) == 0)
-	    return facilitynames[i].c_val;
-    }
-    return 0;
-}
+	case NSCTL_REQ_HELP:
+		response.type = NSCTL_RES_OK;
+		response.argc = 0;
 
-void update_config()
-{
-	int i;
+		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++;
+		}
 
-	snoop_addr.sin_family = AF_INET;
-	snoop_addr.sin_addr.s_addr = config->snoop_destination_host;
-	snoop_addr.sin_port = htons(config->snoop_destination_port);
+		break;
 
-	// Update logging
-	closelog();
-	syslog_log = 0;
-	if (log_stream)
-	{
-		fclose(log_stream);
-		log_stream = NULL;
-	}
-	if (*config->log_filename)
-	{
-		if (strstr(config->log_filename, "syslog:") == config->log_filename)
+	case NSCTL_REQ_CONTROL:
 		{
-			char *p = config->log_filename + 7;
-			if (*p)
+			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)
 			{
-				openlog("l2tpns", LOG_PID, facility_value(p));
-				syslog_log = 1;
+				response.type = NSCTL_RES_ERR;
+				response.argc = 1;
+				response.argv[0] = param.additional
+					? param.additional
+					: "error returned by plugin";
 			}
-		}
-		else if (strchr(config->log_filename, '/') == config->log_filename)
-		{
-			if ((log_stream = fopen((char *)(config->log_filename), "a")))
+			else if (r == PLUGIN_RET_NOTMASTER)
 			{
-				fseek(log_stream, 0, SEEK_END);
-				setbuf(log_stream, NULL);
+				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
 			{
-				log_stream = stderr;
-				setbuf(log_stream, NULL);
+				response.type = param.response;
+				response.argc = 0;
+				if (param.additional)
+				{
+					response.argc = 1;
+					response.argv[0] = param.additional;
+				}
 			}
 		}
-	}
-	else
-	{
-		log_stream = stderr;
-		setbuf(log_stream, NULL);
-	}
 
+		break;
 
-	// Update radius
-	config->numradiusservers = 0;
-	for (i = 0; i < MAXRADSERVER; i++)
-		if (config->radiusserver[i]) config->numradiusservers++;
+	default:
+		response.type = NSCTL_RES_ERR;
+		response.argc = 1;
+		response.argv[0] = "error unpacking control packet";
+	}
 
-	if (!config->numradiusservers)
+	buf = calloc(NSCTL_MAX_PKT_SZ, 1);
+	if (!buf)
 	{
-		log(0, 0, 0, 0, "No RADIUS servers defined!\n");
+		LOG(2, 0, 0, "Failed to allocate nsctl response\n");
+		return;
 	}
 
-	config->num_radfds = 2 << RADIUS_SHIFT;
-
-	// Update plugins
-	for (i = 0; i < MAXPLUGINS; i++)
+	r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
+	if (r > 0)
 	{
-		if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
-			continue;
-		if (*config->plugins[i])
+		sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
+		if (log_stream && config->debug >= 4)
 		{
-			// Plugin added
-			add_plugin(config->plugins[i]);
-		}
-		else if (*config->old_plugins[i])
-		{
-			// Plugin removed
-			remove_plugin(config->old_plugins[i]);
+			LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
+			dump_control(&response, log_stream);
 		}
 	}
-	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 = 1;
-	config->reload_config = 0;
+	else
+		LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
+			fmtaddr(addr->sin_addr.s_addr, 0), r);
+
+	free(buf);
 }
 
-void read_config_file()
+static tunnelidt new_tunnel()
 {
-	FILE *f;
-
-	if (!config->config_file) return;
-	if (!(f = fopen(config->config_file, "r"))) {
-		fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
-		return;
+	tunnelidt i;
+	for (i = 1; i < MAXTUNNEL; i++)
+	{
+		if (tunnel[i].state == TUNNELFREE)
+		{
+			LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
+			if (i > config->cluster_highest_tunnelid)
+				config->cluster_highest_tunnelid = i;
+			return i;
+		}
 	}
-
-	log(3, 0, 0, 0, "Reading config file %s\n", config->config_file);
-	cli_do_file(f);
-	log(3, 0, 0, 0, "Done reading config file\n");
-	fclose(f);
-	update_config();
+	LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
+	return 0;
 }
 
-int sessionsetup(tunnelidt t, sessionidt s, u8 routes)
+//
+// We're becoming the master. Do any required setup..
+//
+// This is principally telling all the plugins that we're
+// now a master, and telling them about all the sessions
+// that are active too..
+//
+void become_master(void)
 {
-	// A session now exists, set it up
-	ipt ip;
-	char *user;
-	sessionidt i;
-#ifdef STAT_CALLS
-	STAT(call_sessionsetup);
-#endif
-	log(3, session[s].ip, s, t, "Doing session setup for session\n");
-	if (!session[s].ip) {
-		log(0, session[s].ip, s, t, "VERY VERY BAD! sessionsetup() called with no session[s].ip\n");
-		return 1;
-	}
+	int s, i;
+	static struct event_data d[RADIUS_FDS];
+	struct epoll_event e;
 
-	// Make sure this is right
-	session[s].tunnel = t;
-	// zap old sessions with same IP and/or username
-	// Don't kill gardened sessions - doing so leads to a DoS
-	// from someone who doesn't need to know the password
-	ip = session[s].ip;
-	user = session[s].user;
-	for (i = 1; i < MAXSESSION; i++)
-	{
-		if (i == s) continue;
-		if (ip == session[i].ip) sessionkill(i, "Duplicate IP address");
-		if (!session[s].walled_garden && !session[i].walled_garden && strcasecmp(user, session[i].user) == 0)
-			sessionkill(i, "Duplicate session for user");
-	}
+	run_plugins(PLUGIN_BECOME_MASTER, NULL);
 
-	if (routes)
+	// running a bunch of iptables commands is slow and can cause
+	// the master to drop tunnels on takeover--kludge around the
+	// problem by forking for the moment (note: race)
+	if (!fork_and_close())
 	{
-		if (session[s].route[routes].ip && session[s].route[routes].mask)
+		for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 		{
-			log(2, session[s].ip, s, t, "Routing session\n");
-			routeset(session[s].ip, 0, 0, 1);
-			while (routes--)
-				routeset(session[s].route[routes].ip, session[s].route[routes].mask,
-						session[s].ip, 1);
+			if (!session[s].opened) // Not an in-use session.
+				continue;
+
+			run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
 		}
+		exit(0);
 	}
-	sessionsendarp(s);
-	if (!session[s].sid)
-		sendipcp(t, s);
-
-	// Force throttling on or off
-	// This has the advantage of cleaning up after another throttled user who may have left
-	// firewall rules lying around
-	session[s].throttle = throttle_session(s, session[s].throttle);
 
+	// add radius fds
+	e.events = EPOLLIN;
+	for (i = 0; i < RADIUS_FDS; i++)
 	{
-		struct param_new_session data = { &tunnel[t], &session[s] };
-		run_plugins(PLUGIN_NEW_SESSION, &data);
+	    	d[i].type = FD_TYPE_RADIUS;
+		d[i].index = i;
+		e.data.ptr = &d[i];
+
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, radfds[i], &e);
 	}
+}
 
-	if (!session[s].sid)
-		session[s].sid = ++last_sid;
+int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
+{
+	int s, i;
+	int count = 0;
+	int buckets[64];
 
-	cache_sessionid(htonl(session[s].ip), s);
+	if (CLI_HELP_REQUESTED)
+		return CLI_HELP_NO_ARGS;
 
-	cluster_send_session(s);
-	session[s].last_packet = time_now;
+	time(&time_now);
+	for (i = 0; i < 64;++i) buckets[i] = 0;
+
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 	{
-		char *sessionip, *tunnelip;
-		sessionip = strdup(inet_toa(ntohl(session[s].ip)));
-		tunnelip = strdup(inet_toa(ntohl(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);
-	}
+		int idle;
+		if (!session[s].opened)
+			continue;
 
-	return 1;       // RADIUS OK and IP allocated, done...
-}
+		idle = time_now - session[s].last_packet;
+		idle /= 5 ; // In multiples of 5 seconds.
+		if (idle < 0)
+			idle = 0;
+		if (idle > 63)
+			idle = 63;
 
-#ifdef RINGBUFFER
-void ringbuffer_dump(FILE *stream)
-{
-	int i = ringbuffer->head;
+		++count;
+		++buckets[idle];
+	}
 
-	while (i != ringbuffer->tail)
+	for (i = 0; i < 63; ++i)
 	{
-		if (*ringbuffer->buffer[i].message)
-			fprintf(stream, "%d-%s", ringbuffer->buffer[i].level, ringbuffer->buffer[i].message);
-		if (++i == ringbuffer->tail) break;
-		if (i == RINGBUFFER_SIZE) i = 0;
+		cli_print(cli, "%3d seconds  : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
 	}
+	cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
+	cli_print(cli, "%d total sessions open.", count);
+	return CLI_OK;
 }
-#endif
 
-void initplugins()
+int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
 {
-	int i;
+	int s, i;
+	int count = 0;
+	int buckets[64];
 
-	loaded_plugins = ll_init();
-	// Initialize the plugins to nothing
-	for (i = 0; i < MAX_PLUGIN_TYPES; i++)
-		plugins[i] = ll_init();
-}
+	if (CLI_HELP_REQUESTED)
+		return CLI_HELP_NO_ARGS;
 
-void add_plugin(char *plugin_name)
-{
-	void *p;
-	int (*initfunc)(struct pluginfuncs *);
-	char path[256] = {0};
-	int i;
-	struct pluginfuncs funcs;
-
-	funcs._log = _log;
-	funcs._log_hex = _log_hex;
-	funcs.inet_toa = inet_toa;
-	funcs.get_session_by_username = sessionbyuser;
-	funcs.get_session_by_id = sessiontbysessionidt;
-	funcs.get_id_by_session = sessionidtbysessiont;
-	funcs.sessionkill = sessionkill;
-	funcs.radiusnew = radiusnew;
-	funcs.radiussend = radiussend;
-
-	snprintf(path, 256, "%s/%s.so", LIBDIR, plugin_name);
-
-	log(2, 0, 0, 0, "Loading plugin from %s\n", path);
-	p = dlopen(path, RTLD_NOW);
-	if (!p)
-	{
-		log(1, 0, 0, 0, "   Plugin load failed: %s\n", dlerror());
-		return;
-	}
+	time(&time_now);
+	for (i = 0; i < 64;++i) buckets[i] = 0;
 
-	if (ll_contains(loaded_plugins, p))
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 	{
-		dlclose(p);
-		return;
-	}
+		int open = 0, d;
+		if (!session[s].opened)
+			continue;
 
-	{
-		int *v = dlsym(p, "__plugin_api_version");
-		if (!v || *v != PLUGIN_API_VERSION)
+		d = time_now - session[s].opened;
+		if (d < 0)
+			d = 0;
+		while (d > 1 && open < 32)
 		{
-			log(1, 0, 0, 0, "   Plugin load failed: API version mismatch: %s\n", dlerror());
-			dlclose(p);
-			return;
+			++open;
+			d >>= 1; // half.
 		}
+		++count;
+		++buckets[open];
 	}
 
-	initfunc = dlsym(p, "plugin_init");
-	if (!initfunc)
-	{
-		log(1, 0, 0, 0, "   Plugin load failed: function plugin_init() does not exist: %s\n", dlerror());
-		dlclose(p);
-		return;
-	}
-
-	if (!initfunc(&funcs))
+	s = 1;
+	for (i = 0; i  < 30; ++i)
 	{
-		log(1, 0, 0, 0, "   Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
-		dlclose(p);
-		return;
+		cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
+		s <<= 1;
 	}
+	cli_print(cli, "%d total sessions open.", count);
+	return CLI_OK;
+}
 
-	for (i = 0; i < max_plugin_functions; i++)
+/* Unhide an avp.
+ *
+ * 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 void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
+{
+	MD5_CTX ctx;
+	uint8_t digest[16];
+	uint8_t *last;
+	size_t d = 0;
+	uint16_t m = htons(type);
+
+	// Compute initial pad
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, (unsigned char *) &m, 2);
+	MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
+	MD5_Update(&ctx, vector, vec_len);
+	MD5_Final(digest, &ctx);
+
+	// pointer to last decoded 16 octets
+	last = value;
+
+	while (len > 0)
 	{
-		void *x;
-		if (!plugin_functions[i]) continue;
-		if ((x = dlsym(p, plugin_functions[i])))
+		// calculate a new pad based on the last decoded block
+		if (d >= sizeof(digest))
 		{
-			log(3, 0, 0, 0, "   Supports function \"%s\"\n", plugin_functions[i]);
-			ll_push(plugins[i], x);
+			MD5_Init(&ctx);
+			MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
+			MD5_Update(&ctx, last, sizeof(digest));
+			MD5_Final(digest, &ctx);
+
+			d = 0;
+			last = value;
 		}
+
+		*value++ ^= digest[d++];
+		len--;
 	}
-	log(2, 0, 0, 0, "   Loaded plugin %s\n", plugin_name);
 }
 
-void remove_plugin(char *plugin_name)
+int find_filter(char const *name, size_t len)
 {
-	void *p;
-	int (*donefunc)();
-	char path[256] = {0};
+	int free = -1;
 	int i;
 
-	snprintf(path, 256, "%s/%s.so", LIBDIR, plugin_name);
+	for (i = 0; i < MAXFILTER; i++)
+	{
+	    	if (!*ip_filters[i].name)
+		{
+			if (free < 0)
+				free = i;
+
+			continue;
+		}
 
-	log(2, 0, 0, 0, "Removing plugin %s\n", plugin_name);
-	// Get the existing pointer
-	p = dlopen(path, RTLD_LAZY);
-	if (!p) return;
+		if (strlen(ip_filters[i].name) != len)
+			continue;
 
-	for (i = 0; i < max_plugin_functions; i++)
-	{
-		void *x;
-		if (!plugin_functions[i]) continue;
-		if ((x = dlsym(p, plugin_functions[i]))) ll_delete(plugins[i], x);
+		if (!strncmp(ip_filters[i].name, name, len))
+			return i;
 	}
+			
+	return free;
+}
 
-	if (ll_contains(loaded_plugins, p))
+static int ip_filter_port(ip_filter_portt *p, uint16_t port)
+{
+	switch (p->op)
 	{
-		ll_delete(loaded_plugins, p);
-
-		donefunc = dlsym(p, "plugin_done");
-		if (donefunc) donefunc();
+	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;
 	}
 
-	dlclose(p);
-	dlclose(p);
-	log(2, 0, 0, 0, "Removed plugin %s\n", plugin_name);
+	return 0;
 }
 
-int run_plugins(int plugin_type, void *data)
+static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
 {
-	int (*func)(void *data);
-	if (!plugins[plugin_type] || plugin_type > max_plugin_functions) return 1;
-
-	ll_reset(plugins[plugin_type]);
-	while ((func = ll_next(plugins[plugin_type])))
+	switch (op)
 	{
-		int rc;
-		rc = func(data);
-		if (rc == PLUGIN_RET_STOP) return 1;
-		if (rc == PLUGIN_RET_ERROR) return 0;
+	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 1;
+
+	return 0;
 }
 
-void processcontrol(u8 * buf, int len, struct sockaddr_in *addr)
+int ip_filter(uint8_t *buf, int len, uint8_t filter)
 {
-	char *resp;
-	int l;
-	struct param_control param = { buf, len, ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port), NULL, 0, 0 };
+	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;
 
-	log(4, ntohl(addr->sin_addr.s_addr), 0, 0, "Received ");
-	if (log_stream)
-		dump_packet(buf, log_stream);
+	if ((*buf >> 4) != 4) // IPv4
+		return 0;
 
-	resp = calloc(1400, 1);
-	l = new_packet(PKT_RESP_ERROR, resp);
-	*(int *)(resp + 6) = *(int *)(buf + 6);
+	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);
 
-	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;
+	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;
 
-	run_plugins(PLUGIN_CONTROL, &param);
+		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;
 
-	if (param.send_response)
-	{
-		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");
+			flags = buf[l + 13] & 0x3f;
+		}
 	}
 
-	free(resp);
-}
+	for (rule = ip_filters[filter].rules; rule->action; rule++)
+	{
+		if (rule->proto != IPPROTO_IP && proto != rule->proto)
+			continue;
 
-/*
- * HACK
- * Go through all of the tunnels and do some cleanups
- */
-void tunnel_clean()
-{
-	int i;
+		if (rule->src_wild != INADDR_BROADCAST &&
+		    (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
+			continue;
 
-	log(1, 0, 0, 0, "Cleaning tunnels array\n");
+		if (rule->dst_wild != INADDR_BROADCAST &&
+		    (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
+			continue;
 
-	for (i = 1; i < MAXTUNNEL; i++)
-	{
-		if (!tunnel[i].ip
-				|| !*tunnel[i].hostname
-				|| (tunnel[i].state == TUNNELDIE && tunnel[i].die >= time_now))
+		if (frag_offset)
 		{
-			tunnelclear(i);
+			// layer 4 deny rules are skipped
+			if (rule->action == FILTER_ACTION_DENY &&
+			    (rule->src_ports.op || rule->dst_ports.op || rule->tcp_flag_op))
+				continue;
 		}
-	}
-}
+		else
+		{
+			if (rule->frag)
+				continue;
 
-void tunnelclear(tunnelidt t)
-{
-	if (!t) return;
-	memset(&tunnel[t], 0, sizeof(tunnel[t]));
-	tunnel[t].state = TUNNELFREE;
-}
+			if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
+			{
+				if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
+					continue;
 
-tunnelidt new_tunnel()
-{
-	tunnelidt i;
-	for (i = 1; i < MAXTUNNEL; i++)
-	{
-		if (tunnel[i].state == TUNNELFREE)
-		{
-			log(4, 0, 0, i, "Assigning tunnel ID %d\n", i);
-			return i;
+				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;
 	}
-	log(0, 0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
-	return 0;
-}
 
+	// default deny
+    	return 0;
+}