X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/d93ad232837788263c14cc07bdfac45a15c78d90..b6ed56dbaf96eb673085083ee5cdc5940fcad591:/l2tpns.c?ds=inline

diff --git a/l2tpns.c b/l2tpns.c
index 5ed1dce..98f4b86 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.83 2005-02-09 00:45:34 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.99 2005-05-07 13:12:25 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -68,11 +68,10 @@ static int rand_fd = -1;	// Random data source
 time_t basetime = 0;		// base clock
 char hostname[1000] = "";	// us.
 static int tunidx;		// ifr_ifindex of tun device
-static uint32_t sessionid = 0;	// session id for radius accounting
 static int syslog_log = 0;	// are we logging to syslog
-static FILE *log_stream = NULL;	// file handle for direct logging (i.e. direct into file, not via syslog).
+static FILE *log_stream = 0;	// file handle for direct logging (i.e. direct into file, not via syslog).
 extern int cluster_sockfd;	// Intra-cluster communications socket.
-uint32_t last_id = 0;		// Last used PPP SID. Can I kill this?? -- mo
+uint32_t last_id = 0;		// Unique ID for radius accounting
 
 struct cli_session_actions *cli_session_actions = NULL;	// Pending session changes requested by CLI
 struct cli_tunnel_actions *cli_tunnel_actions = NULL;	// Pending tunnel changes required by CLI
@@ -111,6 +110,7 @@ config_descriptt config_values[] = {
 	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("radius_authtypes", radius_authtypes_s, STRING),
 	CONFIG("bind_address", bind_address, IPv4),
@@ -187,7 +187,7 @@ static int remove_plugin(char *plugin_name);
 static void plugins_done(void);
 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
 static tunnelidt new_tunnel(void);
-static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length);
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
 
 // return internal time (10ths since process startup)
 static clockt now(void)
@@ -660,7 +660,7 @@ sessionidt sessionbyip(in_addr_t ip)
 	int s = lookup_ipmap(ip);
 	CSTAT(sessionbyip);
 
-	if (s > 0 && s < MAXSESSION && session[s].tunnel)
+	if (s > 0 && s < MAXSESSION && session[s].opened)
 		return (sessionidt) s;
 
 	return 0;
@@ -679,7 +679,7 @@ sessionidt sessionbyipv6(struct in6_addr ip)
 		s = lookup_ipv6map(ip);
 	}
 
-	if (s > 0 && s < MAXSESSION && session[s].tunnel)
+	if (s > 0 && s < MAXSESSION && session[s].opened)
 		return s;
 
 	return 0;
@@ -815,8 +815,11 @@ sessionidt sessionbyuser(char *username)
 	int s;
 	CSTAT(sessionbyuser);
 
-	for (s = 1; s < MAXSESSION ; ++s)
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 	{
+		if (!session[s].opened)
+			continue;
+
 		if (session[s].walled_garden)
 			continue;		// Skip walled garden users.
 
@@ -858,17 +861,16 @@ void send_garp(in_addr_t ip)
 	sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
-// Find session by username, 0 for not found
 static sessiont *sessiontbysessionidt(sessionidt s)
 {
-	if (!s || s > MAXSESSION) return NULL;
+	if (!s || s >= MAXSESSION) return NULL;
 	return &session[s];
 }
 
 static sessionidt sessionidtbysessiont(sessiont *s)
 {
 	sessionidt val = s-session;
-	if (s < session || val > MAXSESSION) return 0;
+	if (s < session || val >= MAXSESSION) return 0;
 	return val;
 }
 
@@ -1262,7 +1264,7 @@ static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
 	c->length += 10;
 }
 
-// add an AVP (32 bit)
+// add an AVP (string)
 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
 {
 	uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
@@ -1357,7 +1359,7 @@ static void controladd(controlt * c, tunnelidt t, sessionidt s)
 //
 void throttle_session(sessionidt s, int rate_in, int rate_out)
 {
-	if (!session[s].tunnel)
+	if (!session[s].opened)
 		return; // No-one home.
 
 	if (!*session[s].user)
@@ -1395,7 +1397,7 @@ void throttle_session(sessionidt s, int rate_in, int rate_out)
 // add/remove filters from session (-1 = no change)
 static void filter_session(sessionidt s, int filter_in, int filter_out)
 {
-	if (!session[s].tunnel)
+	if (!session[s].opened)
 		return; // No-one home.
 
 	if (!*session[s].user)
@@ -1431,16 +1433,16 @@ static void filter_session(sessionidt s, int filter_in, int filter_out)
 }
 
 // start tidy shutdown of session
-void sessionshutdown(sessionidt s, char *reason)
+void sessionshutdown(sessionidt s, char *reason, int result, int error)
 {
 	int walled_garden = session[s].walled_garden;
 
 
 	CSTAT(sessionshutdown);
 
-	if (!session[s].tunnel)
+	if (!session[s].opened)
 	{
-		LOG(3, s, session[s].tunnel, "Called sessionshutdown on a session with no tunnel.\n");
+		LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
 		return;                   // not a live session
 	}
 
@@ -1451,25 +1453,21 @@ void sessionshutdown(sessionidt s, char *reason)
 		run_plugins(PLUGIN_KILL_SESSION, &data);
 	}
 
-	if (session[s].opened && !walled_garden && !session[s].die)
+	if (session[s].ip && !walled_garden && !session[s].die)
 	{
 		// RADIUS Stop message
-		uint16_t r = session[s].radius;
+		uint16_t r = sess_local[s].radius;
 		if (!r)
+			r = radiusnew(s);
+
+		if (r)
 		{
-			if (!(r = radiusnew(s)))
-			{
-				LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
-				STAT(radius_overflow);
-			}
-			else
-			{
-				random_data(radius[r].auth, sizeof(radius[r].auth));
-			}
+			// 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))
@@ -1506,15 +1504,25 @@ void sessionshutdown(sessionidt s, char *reason)
 	if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
 		throttle_session(s, 0, 0);
 
+	if (result)
 	{                            // Send CDN
 		controlt *c = controlnew(14); // sending CDN
-		control16(c, 1, 3, 1);    // result code (admin reasons - TBA make error, general error, add message
+		if (error)
+		{
+			char buf[4];
+			*(uint16_t *) buf     = htons(result);
+			*(uint16_t *) (buf+2) = htons(error);
+			controlb(c, 1, buf, 4, 1);
+		}
+		else
+			control16(c, 1, result, 1);
+
 		control16(c, 14, s, 1);   // assigned session (our end)
 		controladd(c, session[s].tunnel, s); // send the message
 	}
 
 	if (!session[s].die)
-		session[s].die = now() + 150; // Clean up in 15 seconds
+		session[s].die = TIME + 150; // Clean up in 15 seconds
 
 	// update filter refcounts
 	if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
@@ -1526,7 +1534,7 @@ void sessionshutdown(sessionidt s, char *reason)
 void sendipcp(tunnelidt t, sessionidt s)
 {
 	uint8_t buf[MAXCONTROL];
-	uint16_t r = session[s].radius;
+	uint16_t r = sess_local[s].radius;
 	uint8_t *q;
 
 	CSTAT(sendipcp);
@@ -1534,6 +1542,12 @@ void sendipcp(tunnelidt t, sessionidt s)
 	if (!r)
 		r = radiusnew(s);
 
+	if (!r)
+	{
+		sessionshutdown(s, "No free RADIUS sessions for IPCP", 3, 0);
+		return;
+	}
+
 	if (radius[r].state != RADIUSIPCP)
 	{
 		radius[r].state = RADIUSIPCP;
@@ -1544,7 +1558,7 @@ void sendipcp(tunnelidt t, sessionidt s)
 	if (radius[r].try > 10)
 	{
 		radiusclear(r, s);	// Clear radius session.
-		sessionshutdown(s, "No reply on IPCP");
+		sessionshutdown(s, "No reply to IPCP.", 3, 0);
 		return;
 	}
 
@@ -1588,24 +1602,39 @@ void sendipcp(tunnelidt t, sessionidt s)
 	}
 }
 
+static void sessionclear(sessionidt s)
+{
+	memset(&session[s], 0, sizeof(session[s]));
+	memset(&sess_local[s], 0, sizeof(sess_local[s]));
+	memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
+
+	session[s].tunnel = T_FREE;	// Mark it as free.
+	session[s].next = sessionfree;
+	sessionfree = s;
+}
+
 // kill a session now
-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)
 {
 
 	CSTAT(sessionkill);
 
-	session[s].die = now();
-	sessionshutdown(s, reason);  // close radius/routes, etc.
-	if (session[s].radius)
-		radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
+	if (!session[s].opened) // not alive
+		return;
 
-	LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
+	if (session[s].next)
+	{
+		LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
+		return;
+	}
 
-	memset(&session[s], 0, sizeof(session[s]));
-	session[s].tunnel = T_FREE;	// Mark it as free.
-	session[s].next = sessionfree;
-	sessionfree = s;
-	cli_session_actions[s].action = 0;
+	session[s].die = TIME;
+	sessionshutdown(s, reason, 3, 0);  // close radius/routes, etc.
+	if (sess_local[s].radius)
+		radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
+
+	LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
+	sessionclear(s);
 	cluster_send_session(s);
 }
 
@@ -1636,19 +1665,19 @@ static void tunnelkill(tunnelidt t, char *reason)
 		controlfree = c;
 	}
 	// kill sessions
-	for (s = 1; s < MAXSESSION; s++)
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 		if (session[s].tunnel == t)
 			sessionkill(s, reason);
 
 	// free tunnel
 	tunnelclear(t);
 	LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
-	cli_tunnel_actions[s].action = 0;
+	cli_tunnel_actions[t].action = 0;
 	cluster_send_tunnel(t);
 }
 
 // shut down a tunnel cleanly
-static void tunnelshutdown(tunnelidt t, char *reason)
+static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
 {
 	sessionidt s;
 
@@ -1663,19 +1692,40 @@ static void tunnelshutdown(tunnelidt t, char *reason)
 	LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
 
 	// close session
-	for (s = 1; s < MAXSESSION; s++)
+	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 		if (session[s].tunnel == t)
-			sessionshutdown(s, reason);
+			sessionshutdown(s, reason, 3, 0);
 
 	tunnel[t].state = TUNNELDIE;
-	tunnel[t].die = now() + 700; // Clean up in 70 seconds
+	tunnel[t].die = TIME + 700; // Clean up in 70 seconds
 	cluster_send_tunnel(t);
 	// TBA - should we wait for sessions to stop?
-	{                            // Send StopCCN
-		controlt *c = controlnew(4); // sending StopCCN
-		control16(c, 1, 1, 1);    // result code (admin reasons - TBA make error, general error, add message)
-		control16(c, 9, t, 1);    // assigned tunnel (our end)
-		controladd(c, t, 0);      // send the message
+	if (result) 
+	{
+		controlt *c = controlnew(4);	// sending StopCCN
+		if (error)
+		{
+			char buf[64];
+			int l = 4;
+			*(uint16_t *) buf     = htons(result);
+			*(uint16_t *) (buf+2) = htons(error);
+			if (msg)
+			{
+				int m = strlen(msg);
+				if (m + 4 > sizeof(buf))
+				    m = sizeof(buf) - 4;
+
+				memcpy(buf+4, msg, m);
+				l += m;
+			}
+
+			controlb(c, 1, buf, l, 1);
+		}
+		else
+			control16(c, 1, result, 1);
+
+		control16(c, 9, t, 1);		// assigned tunnel (our end)
+		controladd(c, t, 0);		// send the message
 	}
 }
 
@@ -1750,13 +1800,12 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 	{                          // control
 		uint16_t message = 0xFFFF;	// message type
 		uint8_t fatal = 0;
-		uint8_t mandatorymessage = 0;
-		uint8_t chap = 0;		// if CHAP being used
+		uint8_t mandatory = 0;
+		uint8_t authtype = 0;		// proxy auth type
 		uint16_t asession = 0;		// assigned session
 		uint32_t amagic = 0;		// magic number
 		uint8_t aflags = 0;		// flags from last LCF
 		uint16_t version = 0x0100;	// protocol version (we handle 0.0 as well and send that back just in case)
-		int requestchap = 0;		// do we request PAP instead of original CHAP request?
 		char called[MAXTEL] = "";	// called number
 		char calling[MAXTEL] = "";	// calling number
 
@@ -1766,7 +1815,10 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 			return;
 		}
 
-		if ((*buf & 0xCA) != 0xC8)
+		// control messages must have bits 0x80|0x40|0x08
+		// (type, length and sequence) set, and bits 0x02|0x01
+		// (offset and priority) clear
+		if ((*buf & 0xCB) != 0xC8)
 		{
 			LOG(1, s, t, "Bad control header %02X\n", *buf);
 			STAT(tunnel_rx_errors);
@@ -1876,71 +1928,111 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 		}
 		if (l)
 		{                     // if not a null message
+			int result = 0;
+			int error = 0;
+			char *msg = 0;
+
 			// process AVPs
-			while (l && !(fatal & 0x80))
+			while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
 			{
 				uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
 				uint8_t *b = p;
 				uint8_t flags = *p;
 				uint16_t mtype;
-				p += n;       // next
-				if (l < n)
+				if (n > l)
 				{
 					LOG(1, s, t, "Invalid length in AVP\n");
 					STAT(tunnel_rx_errors);
-					fatal = flags;
 					return;
 				}
+				p += n;       // next
 				l -= n;
+				if (flags & 0x3C) // reserved bits, should be clear
+				{
+					LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
+					fatal = flags;
+					result = 2; // general error
+					error = 3; // reserved field non-zero
+					msg = 0;
+					continue; // next
+				}
+				b += 2;
+				if (*(uint16_t *) (b))
+				{
+					LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
+					fatal = flags;
+					result = 2; // general error
+					error = 6; // generic vendor-specific error
+					msg = "unsupported vendor-specific";
+					continue; // next
+				}
+				b += 2;
+				mtype = ntohs(*(uint16_t *) (b));
+				b += 2;
+				n -= 6;
+
 				if (flags & 0x40)
 				{
+					uint16_t orig_len;
+
 					// handle hidden AVPs
 					if (!*config->l2tpsecret)
 					{
 						LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
 						fatal = flags;
+						result = 2; // general error
+						error = 6; // generic vendor-specific error
+						msg = "secret not specified";
 						continue;
 					}
 					if (!session[s].random_vector_length)
 					{
 						LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
 						fatal = flags;
+						result = 2; // general error
+						error = 6; // generic
+						msg = "no random vector";
+						continue;
+					}
+					if (n < 8)
+					{
+						LOG(2, s, t, "Short hidden AVP.\n");
+						fatal = flags;
+						result = 2; // general error
+						error = 2; // length is wrong
+						msg = 0;
 						continue;
 					}
+
 					LOG(4, s, t, "Hidden AVP\n");
+
 					// Unhide the AVP
-					n = unhide_avp(b, t, s, n);
-					if (n == 0)
+					unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
+
+					orig_len = ntohs(*(uint16_t *) b);
+					if (orig_len > n + 2)
 					{
+						LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
+						    orig_len, n);
+
 						fatal = flags;
+						result = 2; // general error
+						error = 2; // length is wrong
+						msg = 0;
 						continue;
 					}
+
+					b += 2;
+					n = orig_len;
 				}
-				if (*b & 0x3C)
-				{
-					LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
-					fatal = flags;
-					continue; // next
-				}
-				b += 2;
-				if (*(uint16_t *) (b))
-				{
-					LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
-					fatal = flags;
-					continue; // next
-				}
-				b += 2;
-				mtype = ntohs(*(uint16_t *) (b));
-				b += 2;
-				n -= 6;
 
 				LOG(4, s, t, "   AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
 				switch (mtype)
 				{
 				case 0:     // message type
 					message = ntohs(*(uint16_t *) b);
+					mandatory = flags & 0x80;
 					LOG(4, s, t, "   Message type = %d (%s)\n", *b, l2tp_message_type(message));
-					mandatorymessage = flags;
 					break;
 				case 1:     // result code
 					{
@@ -1975,6 +2067,9 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 						{   // allow 0.0 and 1.0
 							LOG(1, s, t, "   Bad protocol version %04X\n", version);
 							fatal = flags;
+							result = 5; // unspported protocol version
+							error = 0x0100; // supported version
+							msg = 0;
 							continue; // next
 						}
 					}
@@ -1993,14 +2088,14 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 //					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);
+					memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
+					memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
 					LOG(4, s, t, "   Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
 					// TBA - to send to RADIUS
 					break;
 				case 8:     // vendor name
 					memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
-					memcpy(tunnel[t].vendor, b, (n >= sizeof(tunnel[t].vendor) - 1) ? sizeof(tunnel[t].vendor) - 1 : n);
+					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
@@ -2040,13 +2135,13 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					// TBA
 					break;
 				case 21:    // called number
-					memset(called, 0, MAXTEL);
-					memcpy(called, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
+					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);
+					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
@@ -2059,8 +2154,9 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					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, s, t, "   TX connect speed <%u>\n", session[s].tx_connect_speed);
@@ -2073,8 +2169,9 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					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, s, t, "   RX connect speed <%u>\n", session[s].rx_connect_speed);
@@ -2089,47 +2186,51 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					{
 						uint16_t atype = ntohs(*(uint16_t *)b);
 						LOG(4, s, t, "   Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
-						requestchap = (atype == 2);
+						if (atype == 2)
+							authtype = AUTHCHAP;
+						else if (atype == 3)
+							authtype = AUTHPAP;
+
 						break;
 					}
 				case 30:    // Proxy Authentication Name
 					{
-						char authname[64] = {0};
-						memcpy(authname, b, (n > 63) ? 63 : n);
+						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, s, t, "   Proxy Auth Challenge\n");
+						if (sess_local[s].radius)
+							memcpy(radius[sess_local[s].radius].auth, b, 16);
 						break;
 					}
 				case 32:    // Proxy Authentication ID
 					{
 						uint16_t authid = ntohs(*(uint16_t *)(b));
 						LOG(4, s, t, "   Proxy Auth ID (%d)\n", authid);
-						if (session[s].radius)
-							radius[session[s].radius].id = authid;
+						if (sess_local[s].radius)
+							radius[sess_local[s].radius].id = authid;
 						break;
 					}
 				case 33:    // Proxy Authentication Response
-					{
-						char authresp[64] = {0};
-						memcpy(authresp, b, (n > 63) ? 63 : n);
-						LOG(4, 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
 						uint8_t *p = b, *e = p + n;
 						while (p + 1 < e && p[1] && p + p[1] <= e)
 						{
 							if (*p == 5 && p[1] == 6) // Magic-Number
 								amagic = ntohl(*(uint32_t *) (p + 2));
-							else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
-								chap = 1;
+							else if (*p == 3 && p[1] == 4 && *(uint16_t *) (p + 2) == htons(PPPPAP)) // Authentication-Protocol (PAP)
+								authtype = AUTHPAP;
+							else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol (CHAP)
+								authtype = AUTHCHAP;
 							else if (*p == 7) // Protocol-Field-Compression
 								aflags |= SESSIONPFC;
 							else if (*p == 8) // Address-and-Control-Field-Compression
@@ -2151,14 +2252,20 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					session[s].random_vector_length = n;
 					break;
 				default:
-					LOG(2, s, t, "   Unknown AVP type %d\n", mtype);
-					fatal = flags;
-					continue; // next
+					{
+						static char e[] = "unknown AVP 0xXXXX";
+						LOG(2, s, t, "   Unknown AVP type %d\n", mtype);
+						fatal = flags;
+						result = 2; // general error
+						error = 8; // unknown mandatory AVP
+						sprintf((msg = e) + 14, "%04x", mtype);
+						continue; // next
+					}
 				}
 			}
 			// process message
 			if (fatal & 0x80)
-				tunnelshutdown(t, "Unknown Mandatory AVP");
+				tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
 			else
 				switch (message)
 				{
@@ -2183,8 +2290,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					break;
 				case 4:       // StopCCN
 					controlnull(t); // ack
-					tunnelshutdown(t, "Stopped"); // Shut down cleanly
-					tunnelkill(t, "Stopped"); // Immediately force everything dead
+					tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
 					break;
 				case 6:       // HELLO
 					controlnull(t); // simply ACK
@@ -2202,7 +2308,8 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					if (!sessionfree)
 					{
 						STAT(session_overflow);
-						tunnelshutdown(t, "No free sessions");
+						LOG(1, 0, t, "No free sessions\n");
+						return;
 					}
 					else
 					{
@@ -2220,13 +2327,12 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 						if (!(r = radiusnew(s)))
 						{
 							LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
-							sessionkill(s, "no free RADIUS sesions");
+							sessionclear(s);
 							return;
 						}
 
 						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;
@@ -2234,8 +2340,6 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 						control16(c, 14, s, 1); // assigned session
 						controladd(c, t, s); // send the reply
 
-						// Generate a random challenge
-						random_data(radius[r].auth, sizeof(radius[r].auth));
 						strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
 						strncpy(session[s].called, called, sizeof(session[s].called) - 1);
 						strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
@@ -2251,21 +2355,21 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 					session[s].l2tp_flags = aflags; // set flags received
 					LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
 					controlnull(t); // ack
-					// In CHAP state, request PAP instead
-					if (requestchap)
-						initlcp(t, s);
+					// proxy authentication type is not supported
+					if (authtype && !(config->radius_authtypes & authtype))
+						sendlcp(t, s, config->radius_authprefer);
 					break;
 				case 14:      // CDN
 					controlnull(t); // ack
-					sessionshutdown(s, "Closed (Received CDN)");
+					sessionshutdown(s, "Closed (Received CDN).", 0, 0);
 					break;
 				case 0xFFFF:
 					LOG(1, s, t, "Missing message type\n");
 					break;
 				default:
 					STAT(tunnel_rx_errors);
-					if (mandatorymessage & 0x80)
-						tunnelshutdown(t, "Unknown message");
+					if (mandatory)
+						tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
 					else
 						LOG(1, s, t, "Unknown message type %d\n", message);
 					break;
@@ -2306,7 +2410,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 			l -= 2;
 		}
 
-		if (s && !session[s].tunnel)	// Is something wrong??
+		if (s && !session[s].opened)	// Is something wrong??
 		{
 			if (!config->cluster_iam_master)
 			{
@@ -2316,9 +2420,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 			}
 
 
-			LOG(1, s, t, "UDP packet contains session %d but no session[%d].tunnel "
-				     "exists (LAC said tunnel = %d).  Dropping packet.\n", s, s, t);
-
+			LOG(1, s, t, "UDP packet contains session which is not opened.  Dropping packet.\n");
 			STAT(tunnel_rx_errors);
 			return;
 		}
@@ -2512,7 +2614,7 @@ static int regular_cleanups(void)
 			if (a & CLI_TUN_KILL)
 			{
 				LOG(2, 0, t, "Dropping tunnel by CLI\n");
-				tunnelshutdown(t, "Requested by administrator");
+				tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
 			}
 		}
 
@@ -2525,34 +2627,37 @@ static int regular_cleanups(void)
 		if (s > config->cluster_highest_sessionid)
 			s = 1;
 
-		if (!session[s].tunnel)	// Session isn't in use
+		if (!session[s].opened)	// Session isn't in use
 			continue;
 
-		if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
+		// check for expired sessions
+		if (session[s].die)
 		{
-			// IPCP has not completed yet. Resend
-			LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
-			sendipcp(session[s].tunnel, s);
+			if (session[s].die <= TIME)
+			{
+				sessionkill(s, "Expired");
+				if (++count >= MAX_ACTIONS) break;
+			}
+			continue;
 		}
 
-		// check for expired sessions
-		if (session[s].die && session[s].die <= TIME)
+		if (session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
 		{
-			sessionkill(s, "Expired");
-			if (++count >= MAX_ACTIONS) break;
-			continue;
+			// IPCP has not completed yet. Resend
+			LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
+			sendipcp(session[s].tunnel, s);
 		}
 
 		// Drop sessions who have not responded within IDLE_TIMEOUT seconds
 		if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
 		{
-			sessionshutdown(s, "No response to LCP ECHO requests");
+			sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
 			STAT(session_timeout);
 			if (++count >= MAX_ACTIONS) break;
 			continue;
 		}
 
-		// No data in IDLE_TIMEOUT seconds, send LCP ECHO
+		// No data in ECHO_TIMEOUT seconds, send LCP ECHO
 		if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
 		{
 			uint8_t b[MAXCONTROL] = {0};
@@ -2580,7 +2685,7 @@ static int regular_cleanups(void)
 			if (a & CLI_SESS_KILL)
 			{
 				LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
-				sessionshutdown(s, "Requested by administrator");
+				sessionshutdown(s, "Requested by administrator.", 3, 0);
 				a = 0; // dead, no need to check for other actions
 			}
 
@@ -2639,6 +2744,29 @@ static int regular_cleanups(void)
 
 			if (++count >= MAX_ACTIONS) break;
 		}
+
+		// RADIUS interim accounting
+		if (config->radius_accounting && config->radius_interim > 0
+		    && session[s].ip && !session[s].walled_garden
+		    && !sess_local[s].radius // RADIUS already in progress
+		    && time_now - sess_local[s].last_interim >= config->radius_interim)
+		{
+			if (!(r = radiusnew(s)))
+			{
+				LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
+				STAT(radius_overflow);
+				continue;
+			}
+
+			LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
+				session[s].user, session[s].unique_id);
+
+			radiussend(r, RADIUSINTERIM);
+			sess_local[s].last_interim = time_now;
+
+			if (++count >= MAX_ACTIONS)
+				break;
+		}
 	}
 
 	if (*config->accounting_dir)
@@ -3051,16 +3179,12 @@ static void initdata(int optdebug, char *optconfig)
 {
 	int i;
 
-	if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
-	{
-		LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
-		exit(1);
-	}
 	if (!(config = shared_malloc(sizeof(configt))))
 	{
-		LOG(0, 0, 0, "Error doing malloc for configuration: %s\n", strerror(errno));
+		fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
 		exit(1);
 	}
+
 	memset(config, 0, sizeof(configt));
 	time(&config->start_time);
 	strncpy(config->config_file, optconfig, strlen(optconfig));
@@ -3069,6 +3193,22 @@ static void initdata(int optdebug, char *optconfig)
 	config->rl_rate = 28; // 28kbps
 	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));
@@ -3105,15 +3245,6 @@ static void initdata(int optdebug, char *optconfig)
 	}
 	memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
 
-#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 (!(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));
@@ -3269,8 +3400,9 @@ void rebuild_address_pool(void)
 	for (i = 0; i < MAXSESSION; ++i)
 	{
 		int ipid;
-		if (!session[i].ip || !session[i].tunnel)
+		if (!(session[i].opened && session[i].ip))
 			continue;
+
 		ipid = - lookup_ipmap(htonl(session[i].ip));
 
 		if (session[i].ip_pool_index < 0)
@@ -3680,9 +3812,11 @@ int main(int argc, char *argv[])
 
 static void sighup_handler(int sig)
 {
-	if (log_stream && log_stream != stderr)
+	if (log_stream)
 	{
-		fclose(log_stream);
+		if (log_stream != stderr)
+			fclose(log_stream);
+
 		log_stream = NULL;
 	}
 
@@ -3744,7 +3878,7 @@ static void sigquit_handler(int sig)
 		for (i = 1; i < MAXTUNNEL; i++)
 		{
 			if (tunnel[i].ip || tunnel[i].state)
-				tunnelshutdown(i, "L2TPNS Closing");
+				tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
 		}
 	}
 
@@ -3804,7 +3938,9 @@ static void update_config()
 	syslog_log = 0;
 	if (log_stream)
 	{
-		fclose(log_stream);
+		if (log_stream != stderr)
+			fclose(log_stream);
+
 		log_stream = NULL;
 	}
 
@@ -3886,7 +4022,7 @@ static void update_config()
 		else if (!strncasecmp("pap", p, strlen(p)))
 			type = AUTHPAP;
 		else
-			LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"", p);
+			LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
 
 		config->radius_authtypes |= type;
 		if (!config->radius_authprefer)
@@ -4016,13 +4152,13 @@ int sessionsetup(tunnelidt t, sessionidt s)
 
 	LOG(3, s, t, "Doing session setup for session\n");
 
-	if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
+	if (!session[s].ip)
 	{
 		assign_ip_address(s);
 		if (!session[s].ip)
 		{
 			LOG(0, s, t, "   No IP allocated.  The IP address pool is FULL!\n");
-			sessionshutdown(s, "No IP addresses available");
+			sessionshutdown(s, "No IP addresses available.", 2, 7);
 			return 0;
 		}
 		LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
@@ -4619,7 +4755,7 @@ void become_master(void)
 	{
 		for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 		{
-			if (!session[s].tunnel) // Not an in-use session.
+			if (!session[s].opened) // Not an in-use session.
 				continue;
 
 			run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
@@ -4651,7 +4787,7 @@ int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc
 	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 	{
 		int idle;
-		if (!session[s].tunnel)
+		if (!session[s].opened)
 			continue;
 
 		idle = time_now - session[s].last_packet;
@@ -4689,7 +4825,7 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc
 	for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
 	{
 		int open = 0, d;
-		if (!session[s].tunnel)
+		if (!session[s].opened)
 			continue;
 
 		d = time_now - session[s].opened;
@@ -4716,75 +4852,45 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc
 
 /* Unhide an avp.
  *
- * This unencodes the AVP using the L2TP CHAP secret and the
- * previously stored random vector. It replaces the hidden data with
- * the cleartext data and returns the length of the cleartext data
- * (including the AVP "header" of 6 bytes).
- *
- * Based on code from rp-l2tpd by Roaring Penguin Software Inc.
+ * This unencodes the AVP using the L2TP secret and the previously
+ * stored random vector.  It overwrites the hidden data with the
+ * unhidden AVP subformat.
  */
-static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length)
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
 {
 	MD5_CTX ctx;
-	uint8_t *cursor;
 	uint8_t digest[16];
-	uint8_t working_vector[16];
-	uint16_t hidden_length;
-	uint8_t type[2];
-	size_t done, todo;
-	uint8_t *output;
-
-	// Find the AVP type.
-	type[0] = *(avp + 4);
-	type[1] = *(avp + 5);
-
-	// Line up with the hidden data
-	cursor = output = avp + 6;
+	uint8_t *last;
+	size_t d = 0;
 
 	// Compute initial pad
 	MD5Init(&ctx);
-	MD5Update(&ctx, type, 2);
+	MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
+	MD5Update(&ctx, (uint8_t)  type       & 0xff, 1);
 	MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-	MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length);
+	MD5Update(&ctx, vector, vec_len);
 	MD5Final(digest, &ctx);
 
-	// Get hidden length
-	hidden_length = ((uint16_t) (digest[0] ^ cursor[0])) * 256 + (uint16_t) (digest[1] ^ cursor[1]);
-
-	// Keep these for later use
-	working_vector[0] = *cursor;
-	working_vector[1] = *(cursor + 1);
-	cursor += 2;
+	// pointer to last decoded 16 octets
+	last = value;
 
-	if (hidden_length > length - 8)
+	while (len > 0)
 	{
-		LOG(1, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length);
-		return 0;
-	}
-
-	/* Decrypt remainder */
-	done = 2;
-	todo = hidden_length;
-	while (todo)
-	{
-		working_vector[done] = *cursor;
-		*output = digest[done] ^ *cursor;
-		++output;
-		++cursor;
-		--todo;
-		++done;
-		if (done == 16 && todo)
+		// calculate a new pad based on the last decoded block
+		if (d >= sizeof(digest))
 		{
-			// Compute new digest
-			done = 0;
 			MD5Init(&ctx);
 			MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-			MD5Update(&ctx, &working_vector, 16);
+			MD5Update(&ctx, last, sizeof(digest));
 			MD5Final(digest, &ctx);
+
+			d = 0;
+			last = value;
 		}
-	}
 
-	return hidden_length + 6;
+		*value++ ^= digest[d++];
+		len--;
+	}
 }
 
 static int ip_filter_port(ip_filter_portt *p, uint16_t port)