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remove dead session fields
[l2tpns.git] / l2tpns.c
diff --git a/l2tpns.c b/l2tpns.c
index f49586b..1f47934 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
 // 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 1.82 2005/02/09 00:16:17 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.90 2005/04/18 05:07:20 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
 
 #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
 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).
 extern int cluster_sockfd;     // Intra-cluster communications socket.
 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).
 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
 
 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
@@ -187,7 +186,7 @@ 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 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)
 
 // return internal time (10ths since process startup)
 static clockt now(void)
@@ -660,7 +659,7 @@ sessionidt sessionbyip(in_addr_t ip)
        int s = lookup_ipmap(ip);
        CSTAT(sessionbyip);
 
        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;
                return (sessionidt) s;
 
        return 0;
@@ -679,7 +678,7 @@ sessionidt sessionbyipv6(struct in6_addr ip)
                s = lookup_ipv6map(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;
                return s;
 
        return 0;
@@ -815,8 +814,11 @@ sessionidt sessionbyuser(char *username)
        int s;
        CSTAT(sessionbyuser);
 
        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.
 
                if (session[s].walled_garden)
                        continue;               // Skip walled garden users.
 
@@ -858,17 +860,16 @@ void send_garp(in_addr_t ip)
        sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
        sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
-// Find session by username, 0 for not found
 static sessiont *sessiontbysessionidt(sessionidt s)
 {
 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;
        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;
 }
 
        return val;
 }
 
@@ -1262,7 +1263,7 @@ static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
        c->length += 10;
 }
 
        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);
 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
 {
        uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
@@ -1357,7 +1358,7 @@ static void controladd(controlt * c, tunnelidt t, sessionidt s)
 //
 void throttle_session(sessionidt s, int rate_in, int rate_out)
 {
 //
 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)
                return; // No-one home.
 
        if (!*session[s].user)
@@ -1395,7 +1396,7 @@ 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)
 {
 // 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)
                return; // No-one home.
 
        if (!*session[s].user)
@@ -1431,16 +1432,16 @@ static void filter_session(sessionidt s, int filter_in, int filter_out)
 }
 
 // start tidy shutdown of session
 }
 
 // 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);
 
 {
        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
        }
 
                return;                   // not a live session
        }
 
@@ -1451,7 +1452,7 @@ void sessionshutdown(sessionidt s, char *reason)
                run_plugins(PLUGIN_KILL_SESSION, &data);
        }
 
                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;
        {
                // RADIUS Stop message
                uint16_t r = session[s].radius;
@@ -1506,15 +1507,25 @@ void sessionshutdown(sessionidt s, char *reason)
        if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
                throttle_session(s, 0, 0);
 
        if (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
        {                            // 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)
                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--;
 
        // update filter refcounts
        if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
@@ -1544,7 +1555,7 @@ void sendipcp(tunnelidt t, sessionidt s)
        if (radius[r].try > 10)
        {
                radiusclear(r, s);      // Clear radius session.
        if (radius[r].try > 10)
        {
                radiusclear(r, s);      // Clear radius session.
-               sessionshutdown(s, "No reply on IPCP");
+               sessionshutdown(s, "No reply on IPCP", 3, 0);
                return;
        }
 
                return;
        }
 
@@ -1589,13 +1600,22 @@ void sendipcp(tunnelidt t, sessionidt s)
 }
 
 // kill a session now
 }
 
 // kill a session now
-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)
 {
 
        CSTAT(sessionkill);
 
 {
 
        CSTAT(sessionkill);
 
-       session[s].die = now();
-       sessionshutdown(s, reason);  // close radius/routes, etc.
+       if (!session[s].opened) // not alive
+               return;
+
+       if (session[s].next)
+       {
+               LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
+               return;
+       }
+
+       session[s].die = TIME;
+       sessionshutdown(s, reason, 3, 0);  // close radius/routes, etc.
        if (session[s].radius)
                radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
 
        if (session[s].radius)
                radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
 
@@ -1636,19 +1656,19 @@ static void tunnelkill(tunnelidt t, char *reason)
                controlfree = c;
        }
        // kill sessions
                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);
                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
        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;
 
 {
        sessionidt s;
 
@@ -1663,19 +1683,40 @@ static void tunnelshutdown(tunnelidt t, char *reason)
        LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
 
        // close session
        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)
                if (session[s].tunnel == t)
-                       sessionshutdown(s, reason);
+                       sessionshutdown(s, reason, 3, 0);
 
        tunnel[t].state = TUNNELDIE;
 
        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?
        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
        }
 }
 
        }
 }
 
@@ -1750,7 +1791,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
        {                          // control
                uint16_t message = 0xFFFF;      // message type
                uint8_t fatal = 0;
        {                          // control
                uint16_t message = 0xFFFF;      // message type
                uint8_t fatal = 0;
-               uint8_t mandatorymessage = 0;
+               uint8_t mandatory = 0;
                uint8_t chap = 0;               // if CHAP being used
                uint16_t asession = 0;          // assigned session
                uint32_t amagic = 0;            // magic number
                uint8_t chap = 0;               // if CHAP being used
                uint16_t asession = 0;          // assigned session
                uint32_t amagic = 0;            // magic number
@@ -1766,7 +1807,10 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                        return;
                }
 
                        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);
                {
                        LOG(1, s, t, "Bad control header %02X\n", *buf);
                        STAT(tunnel_rx_errors);
@@ -1876,71 +1920,111 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                }
                if (l)
                {                     // if not a null message
                }
                if (l)
                {                     // if not a null message
+                       int result = 0;
+                       int error = 0;
+                       char *msg = 0;
+
                        // process AVPs
                        // 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;
                        {
                                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);
                                {
                                        LOG(1, s, t, "Invalid length in AVP\n");
                                        STAT(tunnel_rx_errors);
-                                       fatal = flags;
                                        return;
                                }
                                        return;
                                }
+                               p += n;       // next
                                l -= n;
                                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)
                                {
                                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;
                                        // 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;
                                                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;
                                        }
                                                continue;
                                        }
+
                                        LOG(4, s, t, "Hidden AVP\n");
                                        LOG(4, s, t, "Hidden AVP\n");
+
                                        // Unhide the AVP
                                        // 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;
                                                fatal = flags;
+                                               result = 2; // general error
+                                               error = 2; // length is wrong
+                                               msg = 0;
                                                continue;
                                        }
                                                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);
 
                                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));
                                        LOG(4, s, t, "   Message type = %d (%s)\n", *b, l2tp_message_type(message));
-                                       mandatorymessage = flags;
                                        break;
                                case 1:     // result code
                                        {
                                        break;
                                case 1:     // result code
                                        {
@@ -1975,6 +2059,9 @@ 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;
                                                {   // 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
                                                }
                                        }
                                                        continue; // next
                                                }
                                        }
@@ -2151,14 +2238,20 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        session[s].random_vector_length = n;
                                        break;
                                default:
                                        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)
                                }
                        }
                        // process message
                        if (fatal & 0x80)
-                               tunnelshutdown(t, "Unknown Mandatory AVP");
+                               tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
                        else
                                switch (message)
                                {
                        else
                                switch (message)
                                {
@@ -2183,8 +2276,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        break;
                                case 4:       // StopCCN
                                        controlnull(t); // ack
                                        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
                                        break;
                                case 6:       // HELLO
                                        controlnull(t); // simply ACK
@@ -2202,7 +2294,8 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        if (!sessionfree)
                                        {
                                                STAT(session_overflow);
                                        if (!sessionfree)
                                        {
                                                STAT(session_overflow);
-                                               tunnelshutdown(t, "No free sessions");
+                                               LOG(1, 0, t, "No free sessions");
+                                               return;
                                        }
                                        else
                                        {
                                        }
                                        else
                                        {
@@ -2225,8 +2318,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                                }
 
                                                c = controlnew(11); // sending ICRP
                                                }
 
                                                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;
                                                session[s].tunnel = t;
                                                session[s].far = asession;
                                                session[s].last_packet = time_now;
@@ -2257,15 +2349,15 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        break;
                                case 14:      // CDN
                                        controlnull(t); // ack
                                        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);
                                        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;
                                        else
                                                LOG(1, s, t, "Unknown message type %d\n", message);
                                        break;
@@ -2306,7 +2398,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                        l -= 2;
                }
 
                        l -= 2;
                }
 
-               if (s && !session[s].tunnel)    // Is something wrong??
+               if (s && !session[s].opened)    // Is something wrong??
                {
                        if (!config->cluster_iam_master)
                        {
                {
                        if (!config->cluster_iam_master)
                        {
@@ -2316,9 +2408,7 @@ 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;
                }
                        STAT(tunnel_rx_errors);
                        return;
                }
@@ -2512,7 +2602,7 @@ static int regular_cleanups(void)
                        if (a & CLI_TUN_KILL)
                        {
                                LOG(2, 0, t, "Dropping tunnel by CLI\n");
                        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);
                        }
                }
 
                        }
                }
 
@@ -2525,7 +2615,7 @@ static int regular_cleanups(void)
                if (s > config->cluster_highest_sessionid)
                        s = 1;
 
                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))
                        continue;
 
                if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
@@ -2546,13 +2636,13 @@ static int regular_cleanups(void)
                // Drop sessions who have not responded within IDLE_TIMEOUT seconds
                if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
                {
                // 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;
                }
 
                        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};
                if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
                {
                        uint8_t b[MAXCONTROL] = {0};
@@ -2580,7 +2670,7 @@ static int regular_cleanups(void)
                        if (a & CLI_SESS_KILL)
                        {
                                LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
                        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
                        }
 
                                a = 0; // dead, no need to check for other actions
                        }
 
@@ -3134,7 +3224,7 @@ static void initdata(int optdebug, char *optconfig)
        memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
 
                // Put all the sessions on the free list marked as undefined.
        memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
 
                // Put all the sessions on the free list marked as undefined.
-       for (i = 1; i < MAXSESSION - 1; i++)
+       for (i = 1; i < MAXSESSION; i++)
        {
                session[i].next = i + 1;
                session[i].tunnel = T_UNDEF;    // mark it as not filled in.
        {
                session[i].next = i + 1;
                session[i].tunnel = T_UNDEF;    // mark it as not filled in.
@@ -3143,7 +3233,7 @@ static void initdata(int optdebug, char *optconfig)
        sessionfree = 1;
 
                // Mark all the tunnels as undefined (waiting to be filled in by a download).
        sessionfree = 1;
 
                // Mark all the tunnels as undefined (waiting to be filled in by a download).
-       for (i = 1; i < MAXTUNNEL- 1; i++)
+       for (i = 1; i < MAXTUNNEL; i++)
                tunnel[i].state = TUNNELUNDEF;  // mark it as not filled in.
 
        if (!*hostname)
                tunnel[i].state = TUNNELUNDEF;  // mark it as not filled in.
 
        if (!*hostname)
@@ -3269,8 +3359,9 @@ void rebuild_address_pool(void)
        for (i = 0; i < MAXSESSION; ++i)
        {
                int ipid;
        for (i = 0; i < MAXSESSION; ++i)
        {
                int ipid;
-               if (!session[i].ip || !session[i].tunnel)
+               if (!(session[i].opened && session[i].ip))
                        continue;
                        continue;
+
                ipid = - lookup_ipmap(htonl(session[i].ip));
 
                if (session[i].ip_pool_index < 0)
                ipid = - lookup_ipmap(htonl(session[i].ip));
 
                if (session[i].ip_pool_index < 0)
@@ -3744,7 +3835,7 @@ static void sigquit_handler(int sig)
                for (i = 1; i < MAXTUNNEL; i++)
                {
                        if (tunnel[i].ip || tunnel[i].state)
                for (i = 1; i < MAXTUNNEL; i++)
                {
                        if (tunnel[i].ip || tunnel[i].state)
-                               tunnelshutdown(i, "L2TPNS Closing");
+                               tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
                }
        }
 
                }
        }
 
@@ -4016,13 +4107,13 @@ int sessionsetup(tunnelidt t, sessionidt s)
 
        LOG(3, s, t, "Doing session setup for session\n");
 
 
        LOG(3, s, t, "Doing session setup for session\n");
 
-       if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
+       if (!session[s].ip)
        {
                assign_ip_address(s);
                if (!session[s].ip)
                {
                        LOG(0, s, t, "   No IP allocated.  The IP address pool is FULL!\n");
        {
                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",
                        return 0;
                }
                LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
@@ -4619,7 +4710,7 @@ void become_master(void)
        {
                for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                {
        {
                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]);
                                continue;
 
                        run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
@@ -4651,7 +4742,7 @@ 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;
        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;
                        continue;
 
                idle = time_now - session[s].last_packet;
@@ -4689,7 +4780,7 @@ 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;
        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;
                        continue;
 
                d = time_now - session[s].opened;
@@ -4716,75 +4807,45 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc
 
 /* Unhide an avp.
  *
 
 /* 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;
 {
        MD5_CTX ctx;
-       uint8_t *cursor;
        uint8_t digest[16];
        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);
 
        // 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, config->l2tpsecret, strlen(config->l2tpsecret));
-       MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length);
+       MD5Update(&ctx, vector, vec_len);
        MD5Final(digest, &ctx);
 
        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));
                        MD5Init(&ctx);
                        MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
-                       MD5Update(&ctx, &working_vector, 16);
+                       MD5Update(&ctx, last, sizeof(digest));
                        MD5Final(digest, &ctx);
                        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)
 }
 
 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
for cloning use: "git clone git://git.sameswireless.fr/l2tpns.git" ; For add to your sources.list: "deb http://package.sameswifi.fr/ jessie main"