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layer 4 info implies !frag
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index 005d42a..d2411a6 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.76 2005/08/29 03:21:14 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.85 2005/11/04 14:41:50 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
 
 #include <stdio.h>
 #include <string.h>
@@ -88,7 +88,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        if (session[s].ip || !(r = radiusnew(s)))
        {
                // respond now, either no RADIUS available or already authenticated
        if (session[s].ip || !(r = radiusnew(s)))
        {
                // respond now, either no RADIUS available or already authenticated
-               uint8_t b[MAXCONTROL];
+               uint8_t b[MAXETHER];
                uint8_t id = p[1];
                uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP);
                if (!p) return;
                uint8_t id = p[1];
                uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP);
                if (!p) return;
@@ -300,7 +300,7 @@ static void dumplcp(uint8_t *p, int l)
                                else if (length == 5)
                                {
                                        int proto = ntohs(*(uint16_t *)(o + 2));
                                else if (length == 5)
                                {
                                        int proto = ntohs(*(uint16_t *)(o + 2));
-                                       int algo = *(uint8_t *)(o + 4);
+                                       int algo = *(o + 4);
                                        LOG(4, 0, 0, "    %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo,
                                                (proto == PPPCHAP && algo == 5) ? "CHAP MD5"  : "UNSUPPORTED");
                                }
                                        LOG(4, 0, 0, "    %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo,
                                                (proto == PPPCHAP && algo == 5) ? "CHAP MD5"  : "UNSUPPORTED");
                                }
@@ -374,7 +374,7 @@ static void lcp_restart(sessionidt s)
        change_state(s, ccp, Dead);
 }
 
        change_state(s, ccp, Dead);
 }
 
-static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+static uint8_t *ppp_conf_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option)
 {
        if (!*response || **response != ConfigRej)
        uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option)
 {
        if (!*response || **response != ConfigRej)
@@ -397,7 +397,7 @@ static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        return queued + option[1];
 }
 
        return queued + option[1];
 }
 
-static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+static uint8_t *ppp_conf_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option,
        uint8_t *value, size_t vlen)
 {
        uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option,
        uint8_t *value, size_t vlen)
 {
@@ -415,13 +415,13 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
                if (*nak_sent < config->ppp_max_failure) // reject queued
                        return queued;
 
                if (*nak_sent < config->ppp_max_failure) // reject queued
                        return queued;
 
-               return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+               return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
        }
 
        if (!*response)
        {
                if (*nak_sent >= config->ppp_max_failure)
        }
 
        if (!*response)
        {
                if (*nak_sent >= config->ppp_max_failure)
-                       return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+                       return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
 
                queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
                if (!queued)
 
                queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
                if (!queued)
@@ -444,10 +444,35 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        return queued + vlen;
 }
 
        return queued + vlen;
 }
 
+static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
+       char *pname, uint8_t *p, uint16_t l, uint8_t *buf, size_t size)
+{
+       uint8_t *q;
+       int mru = session[s].mru;
+       if (mru > size) mru = size;
+
+       l += 4;
+       if (l > mru) l = mru;
+
+       q = makeppp(buf, size, 0, 0, s, t, proto);
+       if (!q) return;
+
+       *q = CodeRej;
+       *(q + 1) = ++sess_local[s].lcp_ident;
+       *(uint16_t *)(q + 2) = htons(l);
+       memcpy(q + 4, p, l - 4);
+
+       LOG(2, s, t, "Unexpected %s code %s\n", pname, ppp_code(*p));
+       LOG(3, s, t, "%s: send %s\n", pname, ppp_code(*q));
+       if (config->debug > 3) dumplcp(q, l);
+
+       tunnelsend(buf, l + (q - buf), t);
+}
+
 // Process LCP messages
 void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 // Process LCP messages
 void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q = NULL;
        uint32_t magicno = 0;
        uint16_t hl;
        uint8_t *q = NULL;
        uint32_t magicno = 0;
        uint16_t hl;
@@ -521,7 +546,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        if (session[s].ppp.lcp == Opened)
                                lcp_restart(s);
 
                        if (session[s].ppp.lcp == Opened)
                                lcp_restart(s);
 
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        change_state(s, lcp, RequestSent);
                        break;
 
                        change_state(s, lcp, RequestSent);
                        break;
 
@@ -558,7 +583,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                                break;
 
                                        LOG(3, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
                                                break;
 
                                        LOG(3, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
-                                       q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
                                        break;
 
                                case 3: // Authentication-Protocol
                                        break;
 
                                case 3: // Authentication-Protocol
@@ -596,14 +621,14 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                                alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
                                                if (alen < 2) break; // paranoia
 
                                                alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
                                                if (alen < 2) break; // paranoia
 
-                                               q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+                                               q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
                                                if (q && *response == ConfigNak &&
                                                        config->radius_authtypes != config->radius_authprefer)
                                                {
                                                        // alternate type
                                                        alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer);
                                                        if (alen < 2) break;
                                                if (q && *response == ConfigNak &&
                                                        config->radius_authtypes != config->radius_authprefer)
                                                {
                                                        // alternate type
                                                        alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer);
                                                        if (alen < 2) break;
-                                                       q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+                                                       q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
                                                }
 
                                                break;
                                                }
 
                                                break;
@@ -621,7 +646,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                                default: // Reject any unknown options
                                        LOG(3, s, t, "    Rejecting unknown PPP LCP option %d\n", type);
 
                                default: // Reject any unknown options
                                        LOG(3, s, t, "    Rejecting unknown PPP LCP option %d\n", type);
-                                       q = ppp_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
+                                       q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
                        }
                        x -= length;
                        o += length;
                        }
                        x -= length;
                        o += length;
@@ -651,7 +676,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                case Stopped:
                        initialise_restart_count(s, lcp);
 
                case Stopped:
                        initialise_restart_count(s, lcp);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        if (*response == ConfigAck)
                                change_state(s, lcp, AckSent);
                        else
                        if (*response == ConfigAck)
                                change_state(s, lcp, AckSent);
                        else
@@ -673,7 +698,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                case Opened:
                        lcp_restart(s);
 
                case Opened:
                        lcp_restart(s);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        /* fallthrough */
 
                case AckSent:
                        /* fallthrough */
 
                case AckSent:
@@ -694,7 +719,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                tunnelsend(b, l + (response - b), t);
        }
 
                tunnelsend(b, l + (response - b), t);
        }
-       else if (*p == ConfigNak)
+       else if (*p == ConfigNak || *p == ConfigRej)
        {
                int x = l - 4;
                uint8_t *o = (p + 4);
        {
                int x = l - 4;
                uint8_t *o = (p + 4);
@@ -709,14 +734,24 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        switch (type)
                        {
                                case 1: // Maximum-Receive-Unit
                        switch (type)
                        {
                                case 1: // Maximum-Receive-Unit
-                                       session[s].mru = ntohs(*(uint16_t *)(o + 2));
-                                       LOG(3, s, t, "    Remote requested MRU of %u\n", session[s].mru);
+                                       if (*p == ConfigNak)
+                                       {
+                                               sess_local[s].ppp_mru = ntohs(*(uint16_t *)(o + 2));
+                                               LOG(3, s, t, "    Remote requested MRU of %u\n", sess_local[s].ppp_mru);
+                                       }
+                                       else
+                                       {
+                                               sess_local[s].ppp_mru = 0;
+                                               LOG(3, s, t, "    Remote rejected MRU negotiation\n");
+                                       }
+
                                        break;
 
                                case 3: // Authentication-Protocol
                                        if (authtype > 0)
                                                break;
 
                                        break;
 
                                case 3: // Authentication-Protocol
                                        if (authtype > 0)
                                                break;
 
+                                       if (*p == ConfigNak)
                                        {
                                                int proto = ntohs(*(uint16_t *)(o + 2));
                                                if (proto == PPPPAP)
                                        {
                                                int proto = ntohs(*(uint16_t *)(o + 2));
                                                if (proto == PPPPAP)
@@ -737,11 +772,16 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                                                proto);
                                                }
                                        }
                                                                proto);
                                                }
                                        }
+                                       else
+                                       {
+                                               LOG(2, s, t, "LCP: remote rejected auth negotiation\n");
+                                               authtype = 0; // shutdown
+                                       }
 
                                        break;
 
                                default:
 
                                        break;
 
                                default:
-                                       LOG(2, s, t, "    Remote NAKed LCP type %u?\n", type);
+                                       LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type);
                                        break;
                        }
                        x -= length;
                                        break;
                        }
                        x -= length;
@@ -777,17 +817,17 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                case RequestSent:
                case AckSent:
                        initialise_restart_count(s, lcp);
                case RequestSent:
                case AckSent:
                        initialise_restart_count(s, lcp);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                case AckReceived:
                        LOG(2, s, t, "LCP: ConfigNak in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
                        break;
 
                case AckReceived:
                        LOG(2, s, t, "LCP: ConfigNak in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                case Opened:
                        lcp_restart(s);
                        break;
 
                case Opened:
                        lcp_restart(s);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                default:
                        break;
 
                default:
@@ -851,24 +891,9 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                // Ignore it, last_packet time is set earlier than this.
        }
        {
                // Ignore it, last_packet time is set earlier than this.
        }
-       else
+       else if (*p != CodeRej)
        {
        {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
-
-               if (l > mru) l = mru;
-
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
-               if (!q) return;
-
-               LOG(2, s, t, "Unexpected LCP code %s\n", ppp_code(code));
-               LOG(3, s, t, "LCP: send %s\n", ppp_code(*q));
-               if (config->debug > 3) dumplcp(q, l);
-
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
        }
 }
 
        }
 }
 
@@ -878,11 +903,17 @@ static void ipcp_open(sessionidt s, tunnelidt t)
 
        change_state(s, ipcp, Opened);
 
 
        change_state(s, ipcp, Opened);
 
-       if (!session[s].walled_garden)
+       if (!(session[s].walled_garden || session[s].flags & SESSION_STARTED))
        {
                uint16_t r = radiusnew(s);
                if (r)
        {
                uint16_t r = radiusnew(s);
                if (r)
+               {
                        radiussend(r, RADIUSSTART); // send radius start
                        radiussend(r, RADIUSSTART); // send radius start
+
+                       // don't send further Start records if IPCP is restarted
+                       session[s].flags |= SESSION_STARTED;
+                       cluster_send_session(s);
+               }
        }
 
        // start IPv6 if configured and still in passive state
        }
 
        // start IPv6 if configured and still in passive state
@@ -896,7 +927,7 @@ static void ipcp_open(sessionidt s, tunnelidt t)
 // Process IPCP messages
 void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 // Process IPCP messages
 void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q = 0;
        uint16_t hl;
 
        uint8_t *q = 0;
        uint16_t hl;
 
@@ -970,7 +1001,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
                                        uint8_t *oq = q;
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
                                        uint8_t *oq = q;
-                                       q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
                                        if (!q || (q != oq && *response == ConfigRej))
                                        {
                                                sessionshutdown(s, "Can't negotiate IPCP.", 3, 0);
                                        if (!q || (q != oq && *response == ConfigRej))
                                        {
                                                sessionshutdown(s, "Can't negotiate IPCP.", 3, 0);
@@ -986,7 +1017,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                addr = htonl(session[s].dns1);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
                                addr = htonl(session[s].dns1);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
-                                       q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
                                        if (!q) return;
                                }
 
                                        if (!q) return;
                                }
 
@@ -998,7 +1029,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                addr = htonl(session[s].dns1);
                                if (memcmp(o + 2, &addr, sizeof(addr)))
                                {
                                addr = htonl(session[s].dns1);
                                if (memcmp(o + 2, &addr, sizeof(addr)))
                                {
-                                       q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
                                        if (!q) return;
                                }
 
                                        if (!q) return;
                                }
 
@@ -1006,7 +1037,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                        default:
                                LOG(2, s, t, "    Rejecting PPP IPCP Option type %d\n", *o);
 
                        default:
                                LOG(2, s, t, "    Rejecting PPP IPCP Option type %d\n", *o);
-                               q = ppp_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
+                               q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
                                if (!q) return;
                        }
 
                                if (!q) return;
                        }
 
@@ -1094,22 +1125,9 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                tunnelsend(b, l + (q - b), t);
                change_state(s, ipcp, Stopped);
        }
                tunnelsend(b, l + (q - b), t);
                change_state(s, ipcp, Stopped);
        }
-       else
+       else if (*p != CodeRej)
        {
        {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
-
-               if (l > mru) l = mru;
-
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
-               if (!q) return;
-
-               LOG(2, s, t, "Unexpected IPCP code %s\n", ppp_code(code));
-               LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
        }
 }
 
        }
 }
 
@@ -1128,7 +1146,7 @@ static void ipv6cp_open(sessionidt s, tunnelidt t)
 // Process IPV6CP messages
 void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 // Process IPV6CP messages
 void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q = 0;
        uint16_t hl;
 
        uint8_t *q = 0;
        uint16_t hl;
 
@@ -1158,16 +1176,6 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
        LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
 
 
        LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
 
-       if (!config->ipv6_prefix.s6_addr[0])
-       {
-               LOG(2, s, t, "IPV6CP: %s rejected (not configured)\n", ppp_code(*p));
-               *p = ProtocolRej;
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP);
-               if (!q) return;
-               tunnelsend(b, l + (q - b), t);
-               return;
-       }
-
        if (!session[s].ip)
        {
                LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp));
        if (!session[s].ip)
        {
                LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp));
@@ -1219,7 +1227,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                                if (memcmp(o + 2, ident, sizeof(ident)))
                                {
 
                                if (memcmp(o + 2, ident, sizeof(ident)))
                                {
-                                       q = ppp_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
                                        if (!q) return;
                                }
 
                                        if (!q) return;
                                }
 
@@ -1227,7 +1235,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                        default:
                                LOG(2, s, t, "    Rejecting PPP IPV6CP Option type %d\n", *o);
 
                        default:
                                LOG(2, s, t, "    Rejecting PPP IPV6CP Option type %d\n", *o);
-                               q = ppp_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
+                               q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
                                if (!q) return;
                        }
 
                                if (!q) return;
                        }
 
@@ -1315,22 +1323,9 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                tunnelsend(b, l + (q - b), t);
                change_state(s, ipv6cp, Stopped);
        }
                tunnelsend(b, l + (q - b), t);
                change_state(s, ipv6cp, Stopped);
        }
-       else
+       else if (*p != CodeRej)
        {
        {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
-
-               if (l > mru) l = mru;
-
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
-               if (!q) return;
-
-               LOG(2, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code));
-               LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
        }
 }
 
        }
 }
 
@@ -1346,6 +1341,13 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
        LOG_HEX(5, "IP", p, l);
 
 
        LOG_HEX(5, "IP", p, l);
 
+       if (l < 20)
+       {
+               LOG(1, s, t, "IP packet too short %d\n", l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+
        ip = ntohl(*(uint32_t *)(p + 12));
 
        if (l > MAXETHER)
        ip = ntohl(*(uint32_t *)(p + 12));
 
        if (l > MAXETHER)
@@ -1369,6 +1371,14 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
                return;
 
        if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
                return;
 
+       // adjust MSS on SYN and SYN,ACK packets with options
+       if ((ntohs(*(uint16_t *) (p + 6)) & 0x1fff) == 0 && p[9] == IPPROTO_TCP) // first tcp fragment
+       {
+               int ihl = (p[0] & 0xf) * 4; // length of IP header
+               if (l >= ihl + 20 && (p[ihl + 13] & TCP_FLAG_SYN) && ((p[ihl + 12] >> 4) > 5))
+                       adjust_tcp_mss(s, t, p, l, p + ihl);
+       }
+
        // Add on the tun header
        p -= 4;
        *(uint32_t *) p = htonl(PKTIP);
        // Add on the tun header
        p -= 4;
        *(uint32_t *) p = htonl(PKTIP);
@@ -1560,7 +1570,7 @@ void send_ipin(sessionidt s, uint8_t *buf, int len)
 // Process CCP messages
 void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 // Process CCP messages
 void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q;
 
        CSTAT(processccp);
        uint8_t *q;
 
        CSTAT(processccp);
@@ -1676,29 +1686,16 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                tunnelsend(b, l + (q - b), t);
                change_state(s, ccp, Stopped);
        }
                tunnelsend(b, l + (q - b), t);
                change_state(s, ccp, Stopped);
        }
-       else
+       else if (*p != CodeRej)
        {
        {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
-
-               if (l > mru) l = mru;
-
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP);
-               if (!q) return;
-
-               LOG(2, s, t, "Unexpected CCP code %s\n", ppp_code(code));
-               LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b));
        }
 }
 
 // send a CHAP challenge
 void sendchap(sessionidt s, tunnelidt t)
 {
        }
 }
 
 // send a CHAP challenge
 void sendchap(sessionidt s, tunnelidt t)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint16_t r;
        uint8_t *q;
 
        uint16_t r;
        uint8_t *q;
 
@@ -1756,12 +1753,12 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid
        *(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel
        *(uint16_t *) (b + 4) = htons(session[s].far); // session
        b += 6;
        *(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel
        *(uint16_t *) (b + 4) = htons(session[s].far); // session
        b += 6;
-       if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC))
+       if (mtype == PPPLCP || !(session[s].flags & SESSION_ACFC))
        {
                *(uint16_t *) b = htons(0xFF03); // HDLC header
                b += 2;
        }
        {
                *(uint16_t *) b = htons(0xFF03); // HDLC header
                b += 2;
        }
-       if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
+       if (mtype < 0x100 && session[s].flags & SESSION_PFC)
                *b++ = mtype;
        else
        {
                *b++ = mtype;
        else
        {
@@ -1810,9 +1807,10 @@ static int add_lcp_auth(uint8_t *b, int size, int authtype)
 }
 
 // Send initial LCP ConfigReq for MRU, authentication type and magic no
 }
 
 // Send initial LCP ConfigReq for MRU, authentication type and magic no
-void sendlcp(sessionidt s, tunnelidt t, int authtype)
+void sendlcp(sessionidt s, tunnelidt t)
 {
        uint8_t b[500], *q, *l;
 {
        uint8_t b[500], *q, *l;
+       int authtype = sess_local[s].lcp_authtype;
 
        if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP)))
                return;
 
        if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP)))
                return;
@@ -1822,17 +1820,17 @@ void sendlcp(sessionidt s, tunnelidt t, int authtype)
            authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
            authtype ? ")" : "");
 
            authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
            authtype ? ")" : "");
 
-       if (!session[s].mru)
-               session[s].mru = DEFAULT_MRU;
-
        l = q;
        *l++ = ConfigReq;
        l = q;
        *l++ = ConfigReq;
-       *l++ = (time_now % 255) + 1; // ID
+       *l++ = ++sess_local[s].lcp_ident; // ID
 
        l += 2; //Save space for length
 
 
        l += 2; //Save space for length
 
-       *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
-       *(uint16_t *) l = htons(session[s].mru); l += 2;
+       if (sess_local[s].ppp_mru)
+       {
+               *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
+               *(uint16_t *) l = htons(sess_local[s].ppp_mru); l += 2;
+       }
 
        if (authtype)
                l += add_lcp_auth(l, sizeof(b) - (l - b), authtype);
 
        if (authtype)
                l += add_lcp_auth(l, sizeof(b) - (l - b), authtype);
@@ -1847,6 +1845,7 @@ void sendlcp(sessionidt s, tunnelidt t, int authtype)
        if (config->debug > 3) dumplcp(q, l - q);
 
        tunnelsend(b, (l - b), t);
        if (config->debug > 3) dumplcp(q, l - q);
 
        tunnelsend(b, (l - b), t);
+       restart_timer(s, lcp);
 }
 
 // Send CCP request for no compression
 }
 
 // Send CCP request for no compression
@@ -1860,9 +1859,10 @@ void sendccp(sessionidt s, tunnelidt t)
        LOG(3, s, t, "CCP: send ConfigReq (no compression)\n");
 
        *q = ConfigReq;
        LOG(3, s, t, "CCP: send ConfigReq (no compression)\n");
 
        *q = ConfigReq;
-       *(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID
+       *(q + 1) = ++sess_local[s].lcp_ident; // ID
        *(uint16_t *)(q + 2) = htons(4); // Length
 
        LOG_HEX(5, "PPPCCP", q, 4);
        tunnelsend(b, (q - b) + 4 , t);
        *(uint16_t *)(q + 2) = htons(4); // Length
 
        LOG_HEX(5, "PPPCCP", q, 4);
        tunnelsend(b, (q - b) + 4 , t);
+       restart_timer(s, ccp);
 }
 }
for cloning use: "git clone git://git.sameswireless.fr/l2tpns.git" ; For add to your sources.list: "deb http://package.sameswifi.fr/ jessie main"