drop backtrace
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index ff8d4c1..a01c2c0 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.65 2005/07/31 10:04:10 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.89 2005/12/14 02:19:15 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -26,7 +26,7 @@ extern configt *config;
 static int add_lcp_auth(uint8_t *b, int size, int authtype);
 
 // Process PAP messages
-void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
        char user[MAXUSER];
        char pass[MAXPASS];
@@ -85,13 +85,12 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                LOG(3, s, t, "PAP login %s/%s\n", user, pass);
        }
 
-       r = radiusnew(s);
-       if (session[s].ip || !r)
+       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, t, s, PPPPAP);
+               uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP);
                if (!p) return;
 
                if (session[s].ip)
@@ -134,13 +133,13 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                free(packet.password);
 
                radius[r].id = p[1];
-               LOG(3, s, t, "Sending login for %s/%s to radius\n", user, pass);
+               LOG(3, s, t, "Sending login for %s/%s to RADIUS\n", user, pass);
                radiussend(r, RADIUSAUTH);
        }
 }
 
 // Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
        uint16_t r;
        uint16_t hl;
@@ -148,13 +147,6 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        CSTAT(processchap);
 
        LOG_HEX(5, "CHAP", p, l);
-       r = sess_local[s].radius;
-       if (!r)
-       {
-               LOG(1, s, t, "Unexpected CHAP message\n");
-               STAT(tunnel_rx_errors);
-               return;
-       }
 
        if (l < 4)
        {
@@ -181,6 +173,13 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                return;
        }
 
+       r = sess_local[s].radius;
+       if (!r)
+       {
+               LOG(3, s, t, "Unexpected CHAP message\n");
+               return;
+       }
+
        if (session[s].ppp.phase != Authenticate)
        {
                LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
@@ -289,24 +288,24 @@ static void dumplcp(uint8_t *p, int l)
                                        LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), asyncmap);
                                }
                                else
-                                       LOG(4, 0, 0, "   %s odd length %d\n", ppp_lcp_option(type), length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 3: // Authentication-Protocol
                                if (length == 4)
                                {
                                        int proto = ntohs(*(uint16_t *)(o + 2));
-                                       LOG(4, 0, 0, "   %s 0x%x (%s)\n", ppp_lcp_option(type), proto,
+                                       LOG(4, 0, 0, "    %s 0x%x (%s)\n", ppp_lcp_option(type), proto,
                                                proto == PPPPAP  ? "PAP"  : "UNSUPPORTED");
                                }
                                else if (length == 5)
                                {
                                        int proto = ntohs(*(uint16_t *)(o + 2));
-                                       int algo = *(uint8_t *)(o + 4);
-                                       LOG(4, 0, 0, "   %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo,
+                                       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");
                                }
                                else
-                                       LOG(4, 0, 0, "   %s odd length %d\n", ppp_lcp_option(type), length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 4: // Quality-Protocol
                                {
@@ -321,7 +320,7 @@ static void dumplcp(uint8_t *p, int l)
                                        LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), magicno);
                                }
                                else
-                                       LOG(4, 0, 0, "   %s odd length %d\n", ppp_lcp_option(type), length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 7: // Protocol-Field-Compression
                        case 8: // Address-And-Control-Field-Compression
@@ -336,23 +335,25 @@ static void dumplcp(uint8_t *p, int l)
        }
 }
 
-void lcp_open(tunnelidt t, sessionidt s)
+void lcp_open(sessionidt s, tunnelidt t)
 {
        // transition to Authentication or Network phase: 
        session[s].ppp.phase = sess_local[s].lcp_authtype ? Authenticate : Network;
 
+       LOG(3, s, t, "LCP: Opened, phase %s\n", ppp_phase(session[s].ppp.phase));
+
        // LCP now Opened
        change_state(s, lcp, Opened);
 
        if (session[s].ppp.phase == Authenticate)
        {
                if (sess_local[s].lcp_authtype == AUTHCHAP)
-                       sendchap(t, s);
+                       sendchap(s, t);
        }
        else
        {
                // This-Layer-Up
-               sendipcp(t, s);
+               sendipcp(s, t);
                change_state(s, ipcp, RequestSent);
                // move to passive state for IPv6 (if configured), CCP
                if (config->ipv6_prefix.s6_addr[0])
@@ -373,12 +374,12 @@ static void lcp_restart(sessionidt s)
        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)
        {
-               queued = *response = makeppp(buf, blen, packet, 2, session[s].tunnel, s, mtype);
+               queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
                if (!queued)
                        return 0;
 
@@ -396,7 +397,7 @@ static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        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)
 {
@@ -414,19 +415,19 @@ 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;
 
-               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)
-                       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, session[s].tunnel, s, mtype);
+               queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
                if (!queued)
                        return 0;
 
-               *nak_sent++;
+               (*nak_sent)++;
                *queued = ConfigNak;
                queued += 4;
        }
@@ -443,10 +444,36 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
        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 < MINMTU) mru = MINMTU;
+       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(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+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;
@@ -472,15 +499,15 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        if (session[s].die) // going down...
                return;
 
+       LOG(*p == EchoReq ? 4 : 3, s, t, "LCP: recv %s\n", ppp_code(*p));
+       if (config->debug > 3) dumplcp(p, l);
+
        if (*p == ConfigAck)
        {
                int x = l - 4;
                uint8_t *o = (p + 4);
                int authtype = 0;
 
-               LOG(3, s, t, "LCP: ConfigAck (%d bytes)...\n", l);
-               if (config->debug > 3) dumplcp(p, l);
-
                while (x > 2)
                {
                        int type = o[0];
@@ -516,20 +543,20 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                case Opened:
-                       LOG(3, s, t, "LCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
+                       LOG(2, s, t, "LCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
                        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;
 
                case AckSent:
-                       lcp_open(t, s);
+                       lcp_open(s, t);
                        break;
 
                default:
-                       LOG(3, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                }
        }
        else if (*p == ConfigReq)
@@ -540,9 +567,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                static uint8_t asyncmap[4] = { 0, 0, 0, 0 }; // all zero
                static uint8_t authproto[5];
 
-               LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
-               if (config->debug > 3) dumplcp(p, l);
-
                while (x > 2)
                {
                        int type = o[0];
@@ -552,15 +576,26 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        switch (type)
                        {
                                case 1: // Maximum-Receive-Unit
-                                       session[s].mru = ntohs(*(uint16_t *)(o + 2));
+                                       {
+                                               uint16_t mru = ntohs(*(uint16_t *)(o + 2));
+                                               if (mru >= MINMTU)
+                                               {
+                                                       session[s].mru = mru;
+                                                       break;
+                                               }
+
+                                               LOG(3, s, t, "    Remote requesting MRU of %u.  Rejecting.\n", mru);
+                                               mru = htons(MRU);
+                                               q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, (uint8_t *) &mru, sizeof(mru));
+                                       }
                                        break;
 
                                case 2: // Async-Control-Character-Map
                                        if (!ntohl(*(uint32_t *)(o + 2))) // all bits zero is OK
                                                break;
 
-                                       LOG(2, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
-                                       q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
+                                       LOG(3, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
                                        break;
 
                                case 3: // Authentication-Protocol
@@ -593,19 +628,19 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                                else
                                                        sprintf(proto_name, "%#4.4x", proto);
 
-                                               LOG(2, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+                                               LOG(3, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
 
                                                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;
-                                                       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;
@@ -622,8 +657,8 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                        break;
 
                                default: // Reject any unknown options
-                                       LOG(2, s, t, "    Rejecting PPP LCP Option type %d\n", type);
-                                       q = ppp_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
+                                       LOG(3, s, t, "    Rejecting unknown PPP LCP option %d\n", type);
+                                       q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
                        }
                        x -= length;
                        o += length;
@@ -637,7 +672,7 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                else
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -645,7 +680,7 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                switch (session[s].ppp.lcp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -653,7 +688,7 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                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
@@ -669,13 +704,13 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                        if (*response == ConfigAck)
-                               lcp_open(t, s);
+                               lcp_open(s, t);
 
                        break;
 
                case Opened:
                        lcp_restart(s);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        /* fallthrough */
 
                case AckSent:
@@ -687,22 +722,21 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        break;
 
                default:
-                       LOG(3, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                        return;
                }
 
-               LOG(3, s, t, "LCP: Sending %s\n", ppp_code(*response));
+               LOG(3, s, t, "LCP: send %s\n", ppp_code(*response));
+               if (config->debug > 3) dumplcp(response, l);
+
                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 authtype = -1;
 
-               LOG(3, s, t, "LCP: ConfigNak (%d bytes)...\n", l);
-               if (config->debug > 3) dumplcp(p, l);
-
                while (x > 2)
                {
                        int type = o[0];
@@ -712,14 +746,24 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        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;
 
+                                       if (*p == ConfigNak)
                                        {
                                                int proto = ntohs(*(uint16_t *)(o + 2));
                                                if (proto == PPPPAP)
@@ -740,11 +784,16 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                                                proto);
                                                }
                                        }
+                                       else
+                                       {
+                                               LOG(2, s, t, "LCP: remote rejected auth negotiation\n");
+                                               authtype = 0; // shutdown
+                                       }
 
                                        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;
@@ -765,10 +814,14 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                case Closed:
                case Stopped:
                        {
-                               uint8_t *response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP);
+                               uint8_t *response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP);
                                if (!response) return;
                                *response = TerminateAck;
                                *((uint16_t *) (response + 2)) = htons(l = 4);
+
+                               LOG(3, s, t, "LCP: send %s\n", ppp_code(*response));
+                               if (config->debug > 3) dumplcp(response, l);
+
                                tunnelsend(b, l + (response - b), t);
                        }
                        break;
@@ -776,30 +829,33 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                case RequestSent:
                case AckSent:
                        initialise_restart_count(s, lcp);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                case AckReceived:
-                       LOG(3, s, t, "LCP: ConfigNak in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       LOG(2, s, t, "LCP: ConfigNak in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
+                       sendlcp(s, t);
                        break;
 
                case Opened:
                        lcp_restart(s);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                default:
-                       LOG(3, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                        return;
                }
        }
        else if (*p == TerminateReq)
        {
-               LOG(3, s, t, "LCP: Received TerminateReq.  Sending TerminateAck\n");
                *p = TerminateAck;      // close
-               q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPLCP);
                if (!q) return;
+
+               LOG(3, s, t, "LCP: send %s\n", ppp_code(*q));
+               if (config->debug > 3) dumplcp(q, l);
+
                tunnelsend(b, l + (q - b), t); // send it
                sessionshutdown(s, "Remote end closed connection.", 3, 0);
        }
@@ -809,74 +865,81 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        }
        else if (*p == ProtocolRej)
        {
-               if (*(uint16_t *) (p+4) == htons(PPPIPV6CP))
+               uint16_t proto = 0;
+
+               if (l > 4)
+               {
+                       proto = *(p+4);
+                       if (l > 5 && !(proto & 1))
+                       {
+                               proto <<= 8;
+                               proto |= *(p+5);
+                       }
+               }
+
+               if (proto == PPPIPV6CP)
                {
                        LOG(3, s, t, "IPv6 rejected\n");
                        change_state(s, ipv6cp, Closed);
                }
                else
                {
-                       LOG(1, s, t, "Unexpected LCP protocol reject 0x%X\n",
-                               ntohs(*(uint16_t *) (p+4)));
-                       STAT(tunnel_rx_errors);
+                       LOG(3, s, t, "LCP protocol reject: 0x%04X\n", proto);
                }
        }
        else if (*p == EchoReq)
        {
-               LOG(5, s, t, "LCP: Received EchoReq.  Sending EchoReply\n");
                *p = EchoReply;         // reply
                *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number
-               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
                if (!q) return;
+
+               LOG(4, s, t, "LCP: send %s\n", ppp_code(*q));
+               if (config->debug > 3) dumplcp(q, l);
+
                tunnelsend(b, l + (q - b), t); // send it
        }
        else if (*p == EchoReply)
        {
                // 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, t, s, PPPLCP);
-               if (!q) return;
-
-               LOG(3, s, t, "Unexpected LCP code %s\n", ppp_code(code));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
        }
 }
 
-static void ipcp_open(tunnelidt t, sessionidt s)
+static void ipcp_open(sessionidt s, tunnelidt t)
 {
-       LOG(3, s, t, "IPCP Acked, session is now active\n");
+       LOG(3, s, t, "IPCP: Opened, session is now active\n");
 
        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)
+               {
                        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
        if (session[s].ppp.ipv6cp == Stopped)
        {
-               sendipv6cp(t, s);
+               sendipv6cp(s, t);
                change_state(s, ipv6cp, RequestSent);
        }
 }
 
 // Process IPCP messages
-void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+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;
 
@@ -904,6 +967,8 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                return;
        }
 
+       LOG(3, s, t, "IPCP: recv %s\n", ppp_code(*p));
+
        if (*p == ConfigAck)
        {
                switch (session[s].ppp.ipcp)
@@ -915,17 +980,17 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                case Opened:
-                       LOG(3, s, t, "IPCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipcp));
+                       LOG(2, s, t, "IPCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipcp));
                        sendipcp(s, t);
                        change_state(s, ipcp, RequestSent);
                        break;
 
                case AckSent:
-                       ipcp_open(t, s);
+                       ipcp_open(s, t);
                        break;
 
                default:
-                       LOG(3, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
+                       LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
                }
        }
        else if (*p == ConfigReq)
@@ -936,8 +1001,6 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                int gotip = 0;
                in_addr_t addr;
 
-               LOG(4, s, t, "IPCP ConfigReq received\n");
-
                while (length > 2)
                {
                        switch (*o)
@@ -949,8 +1012,9 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                addr = htonl(session[s].ip);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
-                                       q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
-                                       if (!q || *response == ConfigRej)
+                                       uint8_t *oq = q;
+                                       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);
                                                return;
@@ -965,7 +1029,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                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;
                                }
 
@@ -974,10 +1038,10 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        case 131: // secondary DNS
                                if (o[1] != 6 || o[1] > length) return;
 
-                               addr = htonl(session[s].dns1);
+                               addr = htonl(session[s].dns2);
                                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;
                                }
 
@@ -985,7 +1049,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                        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;
                        }
 
@@ -1001,7 +1065,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                else if (gotip)
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -1015,7 +1079,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                switch (session[s].ppp.ipcp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, t, s, PPPIPCP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPCP);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -1039,7 +1103,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                        if (*response == ConfigAck)
-                               ipcp_open(t, s);
+                               ipcp_open(s, t);
 
                        break;
 
@@ -1057,56 +1121,44 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        break;
 
                default:
-                       LOG(3, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
+                       LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
                        return;
                }
 
-               LOG(3, s, t, "IPCP: Sending %s\n", ppp_code(*response));
+               LOG(3, s, t, "IPCP: send %s\n", ppp_code(*response));
                tunnelsend(b, l + (response - b), t);
        }
        else if (*p == TerminateReq)
        {
-               LOG(3, s, t, "IPCP: Received TerminateReq.  Sending TerminateAck\n");
                *p = TerminateAck;
-               q = makeppp(b, sizeof(b),  p, l, t, s, PPPIPCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
                if (!q) return;
+               LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q));
                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, t, s, PPPIPCP);
-               if (!q) return;
-
-               LOG(3, s, t, "Unexpected IPCP code %s\n", ppp_code(code));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
        }
 }
 
-static void ipv6cp_open(tunnelidt t, sessionidt s)
+static void ipv6cp_open(sessionidt s, tunnelidt t)
 {
-       LOG(3, s, t, "IPV6CP Acked\n");
+       LOG(3, s, t, "IPV6CP: Opened\n");
 
        change_state(s, ipv6cp, Opened);
        if (session[s].ipv6prefixlen)
                route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 1);
 
        // Send an initial RA (TODO: Should we send these regularly?)
-       send_ipv6_ra(t, s, NULL);
+       send_ipv6_ra(s, t, NULL);
 }
 
 // Process IPV6CP messages
-void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+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;
 
@@ -1134,15 +1186,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                return;
        }
 
-       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, t, s, PPPIPV6CP);
-               if (!q) return;
-               tunnelsend(b, l + (q - b), t);
-               return;
-       }
+       LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
 
        if (!session[s].ip)
        {
@@ -1161,17 +1205,17 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                case Opened:
-                       LOG(3, s, t, "IPV6CP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipv6cp));
+                       LOG(2, s, t, "IPV6CP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipv6cp));
                        sendipv6cp(s, t);
                        change_state(s, ipv6cp, RequestSent);
                        break;
 
                case AckSent:
-                       ipv6cp_open(t, s);
+                       ipv6cp_open(s, t);
                        break;
 
                default:
-                       LOG(3, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+                       LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
                }
        }
        else if (*p == ConfigReq)
@@ -1182,8 +1226,6 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                int gotip = 0;
                uint8_t ident[8];
 
-               LOG(4, s, t, "IPV6CP ConfigReq received\n");
-
                while (length > 2)
                {
                        switch (*o)
@@ -1197,7 +1239,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                                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;
                                }
 
@@ -1205,7 +1247,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                        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;
                        }
 
@@ -1221,7 +1263,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                else if (gotip)
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, t, s, PPPIPV6CP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -1235,7 +1277,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                switch (session[s].ppp.ipv6cp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, t, s, PPPIPV6CP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPV6CP);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -1259,7 +1301,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                        if (*response == ConfigAck)
-                               ipv6cp_open(t, s);
+                               ipv6cp_open(s, t);
 
                        break;
 
@@ -1277,37 +1319,25 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        break;
 
                default:
-                       LOG(3, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+                       LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
                        return;
                }
 
-               LOG(3, s, t, "IPV6CP: Sending %s\n", ppp_code(*response));
+               LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*response));
                tunnelsend(b, l + (response - b), t);
        }
        else if (*p == TerminateReq)
        {
-               LOG(3, s, t, "IPV6CP: Received TerminateReq.  Sending TerminateAck\n");
                *p = TerminateAck;
-               q = makeppp(b, sizeof(b),  p, l, t, s, PPPIPV6CP);
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP);
                if (!q) return;
+               LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
                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, t, s, PPPIPV6CP);
-               if (!q) return;
-
-               LOG(3, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
        }
 }
 
@@ -1315,7 +1345,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 //
 // This MUST be called with at least 4 byte behind 'p'.
 // (i.e. this routine writes to p[-4]).
-void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
        in_addr_t ip;
 
@@ -1323,6 +1353,13 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t 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)
@@ -1346,6 +1383,14 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        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);
@@ -1401,7 +1446,7 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 //
 // This MUST be called with at least 4 byte behind 'p'.
 // (i.e. this routine writes to p[-4]).
-void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
        struct in6_addr ip;
        in_addr_t ipv4;
@@ -1438,7 +1483,7 @@ void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        *(uint32_t *)(p + 34) == 0 &&
                        *(p + 38) == 0 && *(p + 39) == 2 && *(p + 40) == 133) {
                LOG(3, s, t, "Got IPv6 RS\n");
-               send_ipv6_ra(t, s, &ip);
+               send_ipv6_ra(s, t, &ip);
                return;
        }
 
@@ -1535,9 +1580,9 @@ void send_ipin(sessionidt s, uint8_t *buf, int len)
 
 
 // Process CCP messages
-void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+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);
@@ -1556,6 +1601,7 @@ void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                STAT(tunnel_rx_errors);
        }
 
+       LOG(3, s, t, "CCP: recv %s\n", ppp_code(*p));
        if (*p == ConfigAck)
        {
                switch (session[s].ppp.ccp)
@@ -1567,18 +1613,18 @@ void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                case AckReceived:
                case Opened:
-                       LOG(3, s, t, "CCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ccp));
+                       LOG(2, s, t, "CCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ccp));
                        sendccp(s, t);
                        change_state(s, ccp, RequestSent);
                        break;
 
                case AckSent:
-                       LOG(3, s, t, "CCP Acked\n");
+                       LOG(3, s, t, "CCP: Opened\n");
                        change_state(s, ccp, Opened);
                        break;
 
                default:
-                       LOG(3, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
+                       LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
                }
        }
        else if (*p == ConfigReq)
@@ -1588,13 +1634,13 @@ void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                else // compression requested--reject
                        *p = ConfigRej;
 
-               q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP);
                if (!q) return;
 
                switch (session[s].ppp.ccp)
                {
                case Closed:
-                       q = makeppp(b, sizeof(b), p, 2, t, s, PPPCCP);
+                       q = makeppp(b, sizeof(b), p, 2, s, t, PPPCCP);
                        if (!q) return;
                        *q = TerminateAck;
                        *((uint16_t *) (q + 2)) = htons(l = 4);
@@ -1636,49 +1682,38 @@ void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                        break;
 
                default:
-                       LOG(3, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
+                       LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
                        return;
                }
 
-               LOG(3, s, t, "CCP: Sending %s\n", ppp_code(*q));
+               LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
                tunnelsend(b, l + (q - b), t);
        }
        else if (*p == TerminateReq)
        {
-               LOG(3, s, t, "CCP: Received TerminateReq.  Sending TerminateAck\n");
                *p = TerminateAck;
-               q = makeppp(b, sizeof(b),  p, l, t, s, PPPCCP);
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPCCP);
                if (!q) return;
+               LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
                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, t, s, PPPCCP);
-               if (!q) return;
-
-               LOG(3, s, t, "Unexpected CCP code %s\n", ppp_code(code));
-               tunnelsend(b, l + (q - b), t);
+               ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b));
        }
 }
 
 // send a CHAP challenge
-void sendchap(tunnelidt t, sessionidt s)
+void sendchap(sessionidt s, tunnelidt t)
 {
-       uint8_t b[MAXCONTROL];
-       uint16_t r = sess_local[s].radius;
+       uint8_t b[MAXETHER];
+       uint16_t r;
        uint8_t *q;
 
        CSTAT(sendchap);
 
+       r = radiusnew(s);
        if (!r)
        {
                LOG(1, s, t, "No RADIUS to send challenge\n");
@@ -1701,7 +1736,7 @@ void sendchap(tunnelidt t, sessionidt s)
                STAT(tunnel_tx_errors);
                return ;
        }
-       q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
+       q = makeppp(b, sizeof(b), 0, 0, s, t, PPPCHAP);
        if (!q) return;
 
        *q = 1;                                 // challenge
@@ -1716,13 +1751,11 @@ void sendchap(tunnelidt t, sessionidt s)
 // fill in a L2TP message with a PPP frame,
 // copies existing PPP message and changes magic number if seen
 // returns start of PPP frame
-uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionidt s, uint16_t mtype)
+uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype)
 {
        if (size < 12) // Need more space than this!!
        {
-               static int backtrace_count = 0;
                LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
-               log_backtrace(backtrace_count, 5)
                return NULL;
        }
 
@@ -1730,12 +1763,12 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionid
        *(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;
        }
-       if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
+       if (mtype < 0x100 && session[s].flags & SESSION_PFC)
                *b++ = mtype;
        else
        {
@@ -1745,9 +1778,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionid
 
        if (l + 12 > size)
        {
-               static int backtrace_count = 0;
                LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
-               log_backtrace(backtrace_count, 5)
                return NULL;
        }
 
@@ -1784,28 +1815,30 @@ static int add_lcp_auth(uint8_t *b, int size, int authtype)
 }
 
 // Send initial LCP ConfigReq for MRU, authentication type and magic no
-void sendlcp(tunnelidt t, sessionidt s, int authtype)
+void sendlcp(sessionidt s, tunnelidt t)
 {
        uint8_t b[500], *q, *l;
+       int authtype = sess_local[s].lcp_authtype;
 
-       if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
+       if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP)))
                return;
 
-       LOG(4, s, t, "Sending LCP ConfigReq%s%s\n",
-           authtype ? " for " : "",
-           authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "");
-
-       if (!session[s].mru)
-               session[s].mru = DEFAULT_MRU;
+       LOG(3, s, t, "LCP: send ConfigReq%s%s%s\n",
+           authtype ? " (" : "",
+           authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
+           authtype ? ")" : "");
 
        l = q;
        *l++ = ConfigReq;
-       *l++ = (time_now % 255) + 1; // ID
+       *l++ = ++sess_local[s].lcp_ident; // ID
 
        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);
@@ -1817,22 +1850,57 @@ void sendlcp(tunnelidt t, sessionidt s, int authtype)
        *(uint16_t *)(q + 2) = htons(l - q); // Length
 
        LOG_HEX(5, "PPPLCP", q, l - q);
+       if (config->debug > 3) dumplcp(q, l - q);
+
        tunnelsend(b, (l - b), t);
+       restart_timer(s, lcp);
 }
 
 // Send CCP request for no compression
-void sendccp(tunnelidt t, sessionidt s)
+void sendccp(sessionidt s, tunnelidt t)
 {
        uint8_t b[500], *q;
 
-       if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP)))
+       if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPCCP)))
                return;
 
-       LOG(4, s, t, "Sending CCP ConfigReq for no compression\n");
+       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);
+       restart_timer(s, ccp);
+}
+
+// Reject unknown/unconfigured protocols
+void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto)
+{
+
+       uint8_t buf[MAXETHER];
+       uint8_t *q;
+       int mru = session[s].mru;
+       if (mru < MINMTU) mru = MINMTU;
+       if (mru > sizeof(buf)) mru = sizeof(buf);
+
+       l += 6;
+       if (l > mru) l = mru;
+
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
+       if (!q) return;
+
+       *q = ProtocolRej;
+       *(q + 1) = ++sess_local[s].lcp_ident;
+       *(uint16_t *)(q + 2) = htons(l);
+       *(uint16_t *)(q + 4) = htons(proto);
+       memcpy(q + 6, p, l - 6);
+
+       if (proto == PPPIPV6CP)
+               LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+       else
+               LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+       tunnelsend(buf, l + (q - buf), t);
 }