fix sign problem with reporting of unknown RADIUS VSAs
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index c5aaf19..fd89d91 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.70 2005/08/11 06:18:56 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.101 2006/06/03 08:16:46 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -15,6 +15,8 @@ char const *cvs_id_ppp = "$Id: ppp.c,v 1.70 2005/08/11 06:18:56 bodea Exp $";
 #include "cluster.h"
 
 extern tunnelt *tunnel;
+extern bundlet *bundle;
+extern fragmentationt *frag;
 extern sessiont *session;
 extern radiust *radius;
 extern int tunfd;
@@ -24,6 +26,10 @@ extern time_t time_now;
 extern configt *config;
 
 static int add_lcp_auth(uint8_t *b, int size, int authtype);
+static bundleidt new_bundle(void);
+static int epdiscmp(epdist, epdist);
+static void setepdis(epdist *, epdist);
+static void ipcp_open(sessionidt s, tunnelidt t);
 
 // Process PAP messages
 void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
@@ -40,7 +46,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Short PAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "Short PAP packet.", 3, 0);
+               sessionshutdown(s, "Short PAP packet.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -48,7 +54,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "PAP length mismatch.", 3, 0);
+               sessionshutdown(s, "PAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
        l = hl;
@@ -57,7 +63,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Unexpected PAP code %d\n", *p);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "Unexpected PAP code.", 3, 0);
+               sessionshutdown(s, "Unexpected PAP code.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -85,13 +91,12 @@ void processpap(sessionidt s, tunnelidt t, 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, s, t, PPPPAP);
+               uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP, 0, 0, 0);
                if (!p) return;
 
                if (session[s].ip)
@@ -111,7 +116,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                else
                {
                        LOG(1, s, t, "No RADIUS session available to authenticate session...\n");
-                       sessionshutdown(s, "No free RADIUS sessions.", 4, 0);
+                       sessionshutdown(s, "No free RADIUS sessions.", CDN_UNAVAILABLE, TERM_SERVICE_UNAVAILABLE);
                }
        }
        else
@@ -148,19 +153,12 @@ void processchap(sessionidt s, tunnelidt t, 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)
        {
                LOG(1, s, t, "Short CHAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "Short CHAP packet.", 3, 0);
+               sessionshutdown(s, "Short CHAP packet.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -168,7 +166,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "CHAP length mismatch.", 3, 0);
+               sessionshutdown(s, "CHAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
        l = hl;
@@ -177,7 +175,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "CHAP length mismatch.", 3, 0);
+               sessionshutdown(s, "CHAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -187,11 +185,26 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                return;
        }
 
+       r = sess_local[s].radius;
+       if (!r)
+       {
+               LOG(3, s, t, "Unexpected CHAP message\n");
+
+               // Some modems (Netgear DM602, possibly others) persist in using CHAP even
+               // after ACKing our ConfigReq for PAP.
+               if (sess_local[s].lcp_authtype == AUTHPAP && config->radius_authtypes & AUTHCHAP)
+               {
+                       sess_local[s].lcp_authtype = AUTHCHAP;
+                       sendchap(s, t);
+               }
+               return;
+       }
+
        if (p[1] != radius[r].id)
        {
                LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "Unexpected CHAP response ID.", 3, 0);
+               sessionshutdown(s, "Unexpected CHAP response ID.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -199,7 +212,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "Bad CHAP response length.", 3, 0);
+               sessionshutdown(s, "Bad CHAP response length.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -209,7 +222,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "CHAP user too long %d\n", l - 16);
                STAT(tunnel_rx_errors);
-               sessionshutdown(s, "CHAP username too long.", 3, 0);
+               sessionshutdown(s, "CHAP username too long.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                return;
        }
 
@@ -301,7 +314,7 @@ static void dumplcp(uint8_t *p, int l)
                                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");
                                }
@@ -353,16 +366,29 @@ void lcp_open(sessionidt s, tunnelidt t)
        }
        else
        {
-               // This-Layer-Up
-               sendipcp(s, t);
-               change_state(s, ipcp, RequestSent);
-               // move to passive state for IPv6 (if configured), CCP
-               if (config->ipv6_prefix.s6_addr[0])
-                       change_state(s, ipv6cp, Stopped);
+               if (session[s].bundle && bundle[session[s].bundle].num_of_links > 1)
+               {
+                       sessionidt first_ses = bundle[session[s].bundle].members[0];
+                       LOG(3, s, t, "MPPP: Skipping IPCP negotiation for session:%d, first session of bundle is:%d\n", s, first_ses);
+                       session[s].ip = session[first_ses].ip;
+                       session[s].dns1 = session[first_ses].dns1;
+                       session[s].dns2 = session[first_ses].dns2;
+                       session[s].timeout = session[first_ses].timeout;
+                       ipcp_open(s, t);
+               }
                else
-                       change_state(s, ipv6cp, Closed);
+               {
+                       // This-Layer-Up
+                       sendipcp(s, t);
+                       change_state(s, ipcp, RequestSent);
+                       // move to passive state for IPv6 (if configured), CCP
+                       if (config->ipv6_prefix.s6_addr[0])
+                               change_state(s, ipv6cp, Stopped);
+                       else
+                               change_state(s, ipv6cp, Closed);
 
-               change_state(s, ccp, Stopped);
+                       change_state(s, ccp, Stopped);
+               }
        }
 }
 
@@ -375,12 +401,12 @@ 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, s, session[s].tunnel, mtype);
+               queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype, 0, 0, 0);
                if (!queued)
                        return 0;
 
@@ -398,7 +424,7 @@ 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)
 {
@@ -416,19 +442,19 @@ 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, s, session[s].tunnel, mtype);
+               queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype, 0, 0, 0);
                if (!queued)
                        return 0;
 
-               *nak_sent++;
+               (*nak_sent)++;
                *queued = ConfigNak;
                queued += 4;
        }
@@ -445,12 +471,37 @@ 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, 0, 0, 0);
+       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)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q = NULL;
-       uint32_t magicno = 0;
        uint16_t hl;
 
        CSTAT(processlcp);
@@ -474,7 +525,9 @@ void processlcp(sessionidt s, tunnelidt t, 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));
+       LOG((*p == EchoReq || *p == EchoReply) ? 4 : 3, s, t,
+               "LCP: recv %s\n", ppp_code(*p));
+
        if (config->debug > 3) dumplcp(p, l);
 
        if (*p == ConfigAck)
@@ -522,7 +575,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        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;
 
@@ -541,6 +594,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                uint8_t *response = 0;
                static uint8_t asyncmap[4] = { 0, 0, 0, 0 }; // all zero
                static uint8_t authproto[5];
+               int changed = 0;
 
                while (x > 2)
                {
@@ -551,7 +605,19 @@ void processlcp(sessionidt s, tunnelidt t, 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;
+                                                       changed++;
+                                                       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
@@ -559,7 +625,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                                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
@@ -597,37 +663,95 @@ 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
 
-                                               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;
                                        }
                                        break;
 
-                               case 5: // Magic-Number
-                                       magicno = ntohl(*(uint32_t *)(o + 2));
-                                       break;
-
                                case 4: // Quality-Protocol
+                               case 5: // Magic-Number
                                case 7: // Protocol-Field-Compression
                                case 8: // Address-And-Control-Field-Compression
                                        break;
 
+                               case 17: // Multilink Max-Receive-Reconstructed-Unit
+                                       {
+                                               uint16_t mrru = ntohs(*(uint16_t *)(o + 2));
+                                               session[s].mrru = mrru;
+                                               changed++;
+                                               LOG(3, s, t, "    Received PPP LCP option MRRU: %d\n",mrru);
+                                       }
+                                       break;
+                                       
+                               case 18: // Multilink Short Sequence Number Header Format
+                                       {
+                                               session[s].mssf = 1;
+                                               changed++;
+                                               LOG(3, s, t, "    Received PPP LCP option MSSN format\n");
+                                       }
+                                       break;
+                                       
+                               case 19: // Multilink Endpoint Discriminator
+                                       {
+                                               uint8_t epdis_class = o[2];
+                                               int addr;
+
+                                               session[s].epdis.addr_class = epdis_class;
+                                               session[s].epdis.length = length - 3;
+                                               if (session[s].epdis.length > 20)
+                                               {
+                                                       LOG(1, s, t, "Error: received EndDis Address Length more than 20: %d\n", session[s].epdis.length);
+                                                       session[s].epdis.length = 20;
+                                               }
+
+                                               for (addr = 0; addr < session[s].epdis.length; addr++)
+                                                       session[s].epdis.address[addr] = o[3+addr];
+
+                                               changed++;
+
+                                               switch (epdis_class)
+                                               {
+                                               case LOCALADDR:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis Local Address Class: %d\n",epdis_class);
+                                                       break;
+                                               case IPADDR:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis IP Address Class: %d\n",epdis_class);
+                                                       break;
+                                               case IEEEMACADDR:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis IEEE MAC Address Class: %d\n",epdis_class);
+                                                       break;
+                                               case PPPMAGIC:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis PPP Magic No Class: %d\n",epdis_class);
+                                                       break;
+                                               case PSNDN:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis PSND No Class: %d\n",epdis_class);
+                                                       break;
+                                               default:
+                                                       LOG(3, s, t, "    Received PPP LCP option Multilink EndDis NULL Class %d\n",epdis_class);
+                                               }
+                                       }
+                                       break;
+
                                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;
                }
 
+               if (changed)
+                       cluster_send_session(s);
+
                if (response)
                {
                        l = q - response; // LCP packet length
@@ -636,7 +760,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                else
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP, 0, 0, 0);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -644,7 +768,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                switch (session[s].ppp.lcp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP, 0, 0, 0);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -652,7 +776,7 @@ void processlcp(sessionidt s, tunnelidt t, 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
@@ -674,7 +798,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                case Opened:
                        lcp_restart(s);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        /* fallthrough */
 
                case AckSent:
@@ -695,7 +819,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t 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);
@@ -710,23 +834,38 @@ void processlcp(sessionidt s, tunnelidt t, 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)
+                                       {
+                                               if (length < 4) break;
+                                               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));
+                                               int proto;
+
+                                               if (length < 4) break;
+                                               proto = ntohs(*(uint16_t *)(o + 2));
+
                                                if (proto == PPPPAP)
                                                {
                                                        authtype = config->radius_authtypes & AUTHPAP;
                                                        LOG(3, s, t, "    Remote requested PAP authentication...%sing\n",
                                                                authtype ? "accept" : "reject");
                                                }
-                                               else if (proto == PPPCHAP && *(o + 4) == 5)
+                                               else if (proto == PPPCHAP && length > 4 && *(o + 4) == 5)
                                                {
                                                        authtype = config->radius_authtypes & AUTHCHAP;
                                                        LOG(3, s, t, "    Remote requested CHAP authentication...%sing\n",
@@ -738,12 +877,78 @@ void processlcp(sessionidt s, tunnelidt t, 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);
+                               case 5: // Magic-Number
+                                       session[s].magic = 0;
+                                       if (*p == ConfigNak)
+                                       {
+                                               if (length < 6) break;
+                                               session[s].magic = ntohl(*(uint32_t *)(o + 2));
+                                       }
+
+                                       if (session[s].magic)
+                                               LOG(3, s, t, "    Remote requested magic-no %x\n", session[s].magic);
+                                       else
+                                               LOG(3, s, t, "    Remote rejected magic-no\n");
+
+                                       cluster_send_session(s);
                                        break;
+
+                               case 17: // Multilink Max-Receive-Reconstructed-Unit
+                               {
+                                       if (*p == ConfigNak)
+                                       {
+                                               sess_local[s].mp_mrru = ntohs(*(uint16_t *)(o + 2));
+                                               LOG(3, s, t, "    Remote requested MRRU of %u\n", sess_local[s].mp_mrru);
+                                       }
+                                       else
+                                       {
+                                               sess_local[s].mp_mrru = 0;
+                                               LOG(3, s, t, "    Remote rejected MRRU negotiation\n");
+                                       }
+                               }
+                               break;
+
+                               case 18: // Multilink Short Sequence Number Header Format
+                               {
+                                       if (*p == ConfigNak)
+                                       {
+                                               sess_local[s].mp_mssf = 0;
+                                               LOG(3, s, t, "    Remote requested Naked mssf\n");
+                                       }
+                                       else
+                                       {
+                                               sess_local[s].mp_mssf = 0;
+                                               LOG(3, s, t, "    Remote rejected mssf\n");
+                                       }
+                               }
+                               break;
+
+                               case 19: // Multilink Endpoint Discriminator
+                               {
+                                       if (*p == ConfigNak)
+                                       {
+                                               LOG(2, s, t, "    Remote should not configNak Endpoint Dis!\n");
+                                       }
+                                       else
+                                       {
+                                               sess_local[s].mp_epdis = 0;
+                                               LOG(3, s, t, "    Remote rejected Endpoint Discriminator\n");
+                                       }
+                               }
+                               break;
+
+                               default:
+                                       LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type);
+                                       sessionshutdown(s, "Unable to negotiate LCP.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+                                       return;
                        }
                        x -= length;
                        o += length;
@@ -751,7 +956,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                if (!authtype)
                {
-                       sessionshutdown(s, "Unsupported authentication.", 3, 0);
+                       sessionshutdown(s, "Unsupported authentication.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                        return;
                }
 
@@ -763,7 +968,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                case Closed:
                case Stopped:
                        {
-                               uint8_t *response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP);
+                               uint8_t *response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP, 0, 0, 0);
                                if (!response) return;
                                *response = TerminateAck;
                                *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -778,17 +983,17 @@ void processlcp(sessionidt s, tunnelidt t, 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(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);
-                       sendlcp(s, t, sess_local[s].lcp_authtype);
+                       sendlcp(s, t);
                        break;
 
                default:
@@ -798,39 +1003,66 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
        else if (*p == TerminateReq)
        {
-               *p = TerminateAck;      // close
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPLCP);
+               switch (session[s].ppp.lcp)
+               {
+               case Closed:
+               case Stopped:
+               case Closing:
+               case Stopping:
+               case RequestSent:
+               case AckReceived:
+               case AckSent:
+                       break;
+
+               case Opened:
+                       lcp_restart(s);
+                       zero_restart_count(s, lcp);
+                       change_state(s, lcp, Closing);
+                       break;
+
+               default:
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+                       return;
+               }
+
+               *p = TerminateAck;      // send ack
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPLCP, 0, 0, 0);
                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);
-       }
-       else if (*p == TerminateAck)
-       {
-               sessionshutdown(s, "Connection closed.", 3, 0);
        }
        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)
        {
                *p = EchoReply;         // reply
                *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP, 0, 0, 0);
                if (!q) return;
 
                LOG(4, s, t, "LCP: send %s\n", ppp_code(*q));
@@ -842,25 +1074,97 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                // 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;
+               ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
+       }
+}
+
+int join_bundle(sessionidt s)
+{
+       // Search for a bundle to join
+       bundleidt i;
+       bundleidt b;
+       for (i = 1; i < MAXBUNDLE; i++)
+       {
+               if (bundle[i].state != BUNDLEFREE)
+               {
+                       if (epdiscmp(session[s].epdis,bundle[i].epdis) && !strcmp(session[s].user, bundle[i].user))
+                       {
+                               session[s].bundle = i;
+                               bundle[i].mrru = session[s].mrru;
+                               bundle[i].mssf = session[s].mssf;
+                               if (session[s].epdis.length > 0)
+                                       setepdis(&bundle[i].epdis, session[s].epdis);
+
+                               strcpy(bundle[i].user, session[s].user);
+                               bundle[i].members[bundle[i].num_of_links] = s;
+                               bundle[i].num_of_links++;
+                               LOG(3, s, session[s].tunnel, "MPPP: Bundling additional line in bundle (%d), lines:%d\n",i,bundle[i].num_of_links);
+                               return i;
+                       }
+               }
+       }
 
-               if (l > mru) l = mru;
+       // No previously created bundle was found for this session, so create a new one
+       if (!(b = new_bundle())) return 0;
 
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
-               if (!q) return;
+       session[s].bundle = b;
+       bundle[b].mrru = session[s].mrru;
+       bundle[b].mssf = session[s].mssf;
+       if (session[s].epdis.length > 0)
+               setepdis(&bundle[b].epdis, session[s].epdis);
 
-               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);
+       strcpy(bundle[b].user, session[s].user);
+       bundle[b].members[0] = s;
+       LOG(3, s, session[s].tunnel, "MPPP: Created a new bundle (%d)\n", b);
+       return b;
+}
 
-               tunnelsend(b, l + (q - b), t);
+static int epdiscmp(epdist ep1, epdist ep2)
+{
+       int ad;
+       if (ep1.length != ep2.length)
+               return 0;
+
+       if (ep1.addr_class != ep2.addr_class)
+               return 0;
+
+       for (ad = 0; ad < ep1.length; ad++)
+               if (ep1.address[ad] != ep2.address[ad])
+                       return 0;
+
+       return 1;
+}
+
+static void setepdis(epdist *ep1, epdist ep2)
+{
+       int ad;
+       ep1->length = ep2.length;
+       ep1->addr_class = ep2.addr_class;
+       for (ad = 0; ad < ep2.length; ad++)
+               ep1->address[ad] = ep2.address[ad];
+}
+
+static bundleidt new_bundle()
+{
+       bundleidt i;
+       for (i = 1; i < MAXBUNDLE; i++)
+       {
+               if (bundle[i].state == BUNDLEFREE)
+               {
+                       LOG(4, 0, 0, "MPPP: Assigning bundle ID %d\n", i);
+                       bundle[i].num_of_links = 1;
+                       bundle[i].last_check = time_now;        // Initialize last_check value
+                       bundle[i].state = BUNDLEOPEN;
+                       bundle[i].current_ses = -1;     // This is to enforce the first session 0 to be used at first
+                       if (i > config->cluster_highest_bundleid)
+                               config->cluster_highest_bundleid = i;
+                       return i;
+               }
        }
+       LOG(0, 0, 0, "MPPP: Can't find a free bundle! There shouldn't be this many in use!\n");
+       return 0;
 }
 
 static void ipcp_open(sessionidt s, tunnelidt t)
@@ -869,11 +1173,17 @@ static void ipcp_open(sessionidt s, tunnelidt t)
 
        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
@@ -887,14 +1197,14 @@ static void ipcp_open(sessionidt s, tunnelidt t)
 // 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;
 
        CSTAT(processipcp);
 
        LOG_HEX(5, "IPCP", p, l);
-       if (l < 5)
+       if (l < 4)
        {
                LOG(1, s, t, "Short IPCP %d bytes\n", l);
                STAT(tunnel_rx_errors);
@@ -951,19 +1261,22 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                while (length > 2)
                {
+                       if (!o[1] || o[1] > length) return;
+
                        switch (*o)
                        {
                        case 3: // ip address
                                gotip++; // seen address
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) return;
 
                                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);
+                                               sessionshutdown(s, "Can't negotiate IPCP.", CDN_ADMIN_DISC, TERM_USER_ERROR);
                                                return;
                                        }
                                }
@@ -971,24 +1284,24 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                break;
 
                        case 129: // primary DNS
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) return;
 
                                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;
                                }
 
                                break;
 
                        case 131: // secondary DNS
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) 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;
                                }
 
@@ -996,7 +1309,7 @@ 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);
-                               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;
                        }
 
@@ -1012,7 +1325,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                else if (gotip)
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP, 0, 0, 0);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -1026,7 +1339,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                switch (session[s].ppp.ipcp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPCP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPCP, 0, 0, 0);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -1077,29 +1390,37 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
        else if (*p == TerminateReq)
        {
-               *p = TerminateAck;
-               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
-       {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
+               switch (session[s].ppp.ipcp)
+               {
+               case Closed:
+               case Stopped:
+               case Closing:
+               case Stopping:
+               case RequestSent:
+               case AckReceived:
+               case AckSent:
+                       break;
 
-               if (l > mru) l = mru;
+               case Opened:
+                       zero_restart_count(s, ipcp);
+                       change_state(s, ipcp, Closing);
+                       break;
+
+               default:
+                       LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
+                       return;
+               }
 
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
+               *p = TerminateAck;      // send ack
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP, 0, 0, 0);
                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);
+               tunnelsend(b, l + (q - b), t); // send it
+       }
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
        }
 }
 
@@ -1118,7 +1439,7 @@ static void ipv6cp_open(sessionidt s, tunnelidt t)
 // 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;
 
@@ -1148,16 +1469,6 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
        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));
@@ -1198,18 +1509,20 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                while (length > 2)
                {
+                       if (!o[1] || o[1] > length) return;
+
                        switch (*o)
                        {
                        case 1: // interface identifier
                                gotip++; // seen address
-                               if (o[1] != 10 || o[1] > length) return;
+                               if (o[1] != 10) return;
 
                                *(uint32_t *) ident = htonl(session[s].ip);
                                *(uint32_t *) (ident + 4) = 0;
 
                                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;
                                }
 
@@ -1217,7 +1530,7 @@ 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);
-                               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;
                        }
 
@@ -1233,7 +1546,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                else if (gotip)
                {
                        // Send packet back as ConfigAck
-                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP, 0, 0, 0);
                        if (!response) return;
                        *response = ConfigAck;
                }
@@ -1247,7 +1560,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                switch (session[s].ppp.ipv6cp)
                {
                case Closed:
-                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPV6CP);
+                       response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPV6CP, 0, 0, 0);
                        if (!response) return;
                        *response = TerminateAck;
                        *((uint16_t *) (response + 2)) = htons(l = 4);
@@ -1298,29 +1611,37 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
        else if (*p == TerminateReq)
        {
-               *p = TerminateAck;
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP);
-               if (!q) return;
-               LOG(3, s, t, "IPV6CP: Sending %s\n", ppp_code(*response));
-               tunnelsend(b, l + (q - b), t);
-               change_state(s, ipv6cp, Stopped);
-       }
-       else
-       {
-               int code = *p;
-               int mru = session[s].mru;
-               if (!mru)
-                       mru = DEFAULT_MRU;
+               switch (session[s].ppp.ipv6cp)
+               {
+               case Closed:
+               case Stopped:
+               case Closing:
+               case Stopping:
+               case RequestSent:
+               case AckReceived:
+               case AckSent:
+                       break;
 
-               if (l > mru) l = mru;
+               case Opened:
+                       zero_restart_count(s, ipv6cp);
+                       change_state(s, ipv6cp, Closing);
+                       break;
 
-               *p = CodeRej;
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
+               default:
+                       LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+                       return;
+               }
+
+               *p = TerminateAck;      // send ack
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP, 0, 0, 0);
                if (!q) return;
 
-               LOG(2, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code));
-               LOG(3, s, t, "IPV6CP: Sending %s\n", ppp_code(*response));
-               tunnelsend(b, l + (q - b), t);
+               LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
+               tunnelsend(b, l + (q - b), t); // send it
+       }
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
        }
 }
 
@@ -1336,6 +1657,13 @@ void processipin(sessionidt s, tunnelidt t, 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)
@@ -1348,17 +1676,28 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        if (session[s].ppp.phase != Network || session[s].ppp.ipcp != Opened)
                return;
 
-       // no spoof (do sessionbyip to handled statically routed subnets)
-       if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
+       if (!session[s].bundle || bundle[session[s].bundle].num_of_links < 2) // FIXME: 
        {
-               LOG(5, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0));
-               return;
+               // no spoof (do sessionbyip to handled statically routed subnets)
+               if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
+               {
+                       LOG(4, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0));
+                       return;
+               }
        }
 
        // run access-list if any
        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);
@@ -1410,6 +1749,167 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        INC_STAT(tun_tx_bytes, l);
 }
 
+// process Multilink PPP packet received
+void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
+{
+       bundleidt b = session[s].bundle;
+       uint8_t begin_frame;
+       uint8_t end_frame;
+       uint32_t seq_num;
+       uint32_t offset;
+
+       if (!b)
+       {
+               LOG(3, s, t, "MPPP: Invalid bundle id: 0\n");
+               return;
+       }
+
+       begin_frame = (*p & 0x80);
+       end_frame = (*p & 0x40);
+       if (session[s].mssf)
+       {
+               // Get 12 bit for seq number
+               uint16_t short_seq_num = ntohs((*(uint16_t *) p) & 0xFF0F);
+               uint16_t short_seq_num2 = short_seq_num >> 4;
+               p += 2;
+               l -= 2;
+               seq_num = short_seq_num2;
+               // After this point the pointer should be advanced 2 bytes
+               LOG(3, s, t, "MPPP: 12 bits, sequence number: %d, short1: %d, short2: %d\n",seq_num, short_seq_num, short_seq_num2);
+       }
+       else
+       {
+               // Get 24 bit for seq number
+               p++;
+               seq_num = ntohl((*(uint32_t *) p) & 0xFFFFFF00);
+               seq_num = seq_num >> 8;
+               p += 3;
+               l -= 4;
+               // After this point the pointer should be advanced 4 bytes
+               LOG(4, s, t, "MPPP: 24 bits sequence number:%d\n",seq_num);
+       }
+
+       if (seq_num - bundle[b].offset < 0)
+       {
+               bundle[b].offset = 0;
+               bundle[b].pending_frag = 0;
+       }
+
+       offset = bundle[b].offset;
+       if (begin_frame)
+       {
+               // Check for previous non-assembled frames
+               int error = 0;
+               if (bundle[b].pending_frag)
+               {
+                       uint32_t fn = bundle[b].seq_num_m - offset;
+                       uint16_t cur_len;
+                       bundle[b].pending_frag = 0;
+                       // Check for array indexes
+                       if (fn < 0 || fn > MAXFRAGNUM)
+                       {
+                               LOG(2, s, t, "ERROR: Index out of range fn:%d, bundle:%d\n",fn,b);
+                               return;
+                       }
+
+                       if (seq_num-offset < 0 || seq_num-offset > MAXFRAGNUM)
+                       {
+                               LOG(2, s, t, "ERROR: Index out of range fn(last):%d, bundle:%d\n",fn,b);
+                               return;
+                       }
+                       /////////////////////////////////////////////////////
+                       cur_len = 4;   // This is set to 4 to leave 4 bytes for function processipin
+                       for (fn = bundle[b].seq_num_m - offset; fn < seq_num - offset; fn++)
+                       {
+                               if (!frag[b].fragment[fn].length)
+                               {
+                                       LOG(4, s, t, "MPPP: Found lost fragment while reassembling frame %d in (%d,%d)\n",fn, bundle[b].seq_num_m-offset, seq_num-offset);
+                                       error = 1;
+                                       break;
+                               }
+
+                               if (cur_len + frag[b].fragment[fn].length > MAXETHER)
+                               {
+                                       LOG(2, s, t, "MPPP: ERROR: very long frame after assembling %d\n", frag[b].fragment[fn].length+cur_len);
+                                       error = 1;
+                                       break;
+                               }
+
+                               memcpy(frag[b].reassembled_frame+cur_len, frag[b].fragment[fn].data, frag[b].fragment[fn].length);
+                               cur_len += frag[b].fragment[fn].length; 
+                               frag[b].fragment[fn].length = 0;      // Indicates that this fragment has been consumed
+                               // This is usefull for compression
+                               memset(frag[b].fragment[fn].data, 0, sizeof(frag[b].fragment[fn].data));
+                       }
+
+                       if (!error)
+                       {
+                               frag[b].re_frame_len = cur_len;
+                               // Process the resassembled frame
+                               LOG(4, s, t, "MPPP: Process the reassembled frame, len=%d\n",cur_len);
+                               processmpframe(s, t, frag[b].reassembled_frame, frag[b].re_frame_len, 1);
+                               // Set reassembled frame length to zero after processing it
+                               frag[b].re_frame_len = 0;
+                               memset(frag[b].reassembled_frame, 0, sizeof(frag[b].reassembled_frame));
+                       }
+               }
+               //////////////////////////////////////////
+               bundle[b].seq_num_m = seq_num;
+               if (end_frame)
+               {
+                       // Both bits are set
+                       LOG(4, s, t, "MPPP: Both bits are set (Begin and End).\n");
+                       processmpframe(s, t, p, l, 0);
+                       // The maximum number of fragments is 1500
+                       if (seq_num - bundle[b].offset >= 1400)
+                       {
+                               bundle[b].offset = seq_num;
+                               LOG(4, s, t, "MPPP: Setting offset to: %d\n",bundle[b].offset);
+                       }
+               }
+               else
+               {
+                       bundle[b].pending_frag = 1;
+                       // End bit is clear
+                       LOG(4, s, t, "MPPP: Push to receive buffer\n");
+                       // Push to the receive buffer
+                       // Array indexes checking
+                       if (seq_num-offset < 0 || seq_num-offset >= MAXFRAGNUM)
+                       {
+                               LOG(2, s, t, "ERROR: Index out of range, push to receive buffer(1) seq:%d, offset:%d, bundle:%d\n",seq_num,offset,b);
+                               return;
+                       }
+                       // Perform length checking
+                       if (l > MAXFRAGLEN)
+                       {
+                               LOG(2, s, t, "MPPP: ERROR: very long fragment length (1)\n");
+                               return;
+                       }
+                       frag[b].fragment[seq_num - offset].length = l;
+                       memcpy(frag[b].fragment[seq_num - offset].data, p, l);
+               }
+       }
+       else
+       {
+               LOG(4, s, t, "MPPP: Push to receive buffer\n");
+               // Push to the receive buffer
+               // Array indexes checking
+               if (seq_num-offset < 0 || seq_num-offset >= MAXFRAGNUM)
+               {
+                       LOG(2, s, t, "ERROR: Index out of range, push to receive buffer(2) seq:%d, offset:%d, bundle:%d\n",seq_num,offset,b);
+                       return;
+               }
+               // Perform length checking
+               if (l > MAXFRAGLEN)
+               {
+                       LOG(2, s, t, "MPPP: ERROR: very long fragment length (2).\n");
+                       return;
+               }
+               frag[b].fragment[seq_num - offset].length = l;
+               memcpy(frag[b].fragment[seq_num - offset].data, p, l);
+       }
+}
+
 // process IPv6 packet received
 //
 // This MUST be called with at least 4 byte behind 'p'.
@@ -1550,7 +2050,7 @@ 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)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint8_t *q;
 
        CSTAT(processccp);
@@ -1569,7 +2069,7 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                STAT(tunnel_rx_errors);
        }
 
-       LOG(3, s, t, "CCP: recv %s\n", ppp_code(*p));
+       LOG(4, s, t, "CCP: recv %s\n", ppp_code(*p));
        if (*p == ConfigAck)
        {
                switch (session[s].ppp.ccp)
@@ -1602,13 +2102,13 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                else // compression requested--reject
                        *p = ConfigRej;
 
-               q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP, 0, 0, 0);
                if (!q) return;
 
                switch (session[s].ppp.ccp)
                {
                case Closed:
-                       q = makeppp(b, sizeof(b), p, 2, s, t, PPPCCP);
+                       q = makeppp(b, sizeof(b), p, 2, s, t, PPPCCP, 0, 0, 0);
                        if (!q) return;
                        *q = TerminateAck;
                        *((uint16_t *) (q + 2)) = htons(l = 4);
@@ -1654,41 +2154,28 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        return;
                }
 
-               LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
+               LOG(4, s, t, "CCP: send %s\n", ppp_code(*q));
                tunnelsend(b, l + (q - b), t);
        }
        else if (*p == TerminateReq)
        {
                *p = TerminateAck;
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPCCP);
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPCCP, 0, 0, 0);
                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, 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)
 {
-       uint8_t b[MAXCONTROL];
+       uint8_t b[MAXETHER];
        uint16_t r;
        uint8_t *q;
 
@@ -1713,11 +2200,11 @@ void sendchap(sessionidt s, tunnelidt t)
        radius[r].retry = backoff(radius[r].try++);
        if (radius[r].try > 5)
        {
-               sessionshutdown(s, "CHAP timeout.", 3, 0);
+               sessionshutdown(s, "CHAP timeout.", CDN_ADMIN_DISC, TERM_REAUTHENTICATION_FAILURE);
                STAT(tunnel_tx_errors);
                return ;
        }
-       q = makeppp(b, sizeof(b), 0, 0, s, t, PPPCHAP);
+       q = makeppp(b, sizeof(b), 0, 0, s, t, PPPCHAP, 0, 0, 0);
        if (!q) return;
 
        *q = 1;                                 // challenge
@@ -1730,43 +2217,87 @@ void sendchap(sessionidt s, tunnelidt t)
 }
 
 // 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, sessionidt s, tunnelidt t, uint16_t mtype)
+uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits)
 {
-       if (size < 12) // Need more space than this!!
+       uint16_t hdr = 0x0002; // L2TP with no options
+       uint16_t type = mtype;
+       uint8_t *start = b;
+
+       if (size < 16) // 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;
        }
 
-       *(uint16_t *) (b + 0) = htons(0x0002); // L2TP with no options
+       if (prio) hdr |= 0x0100; // set priority bit
+
+       *(uint16_t *) (b + 0) = htons(hdr);
        *(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))
+
+       // Check whether this session is part of multilink
+       if (bid)
+       {
+               if (bundle[bid].num_of_links > 1)
+                       type = PPPMP; // Change PPP message type to the PPPMP
+               else
+                       bid = 0;
+       }
+
+       if (type == PPPLCP || !(session[s].flags & SESSION_ACFC))
        {
                *(uint16_t *) b = htons(0xFF03); // HDLC header
                b += 2;
        }
-       if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
-               *b++ = mtype;
+
+       if (type < 0x100 && session[s].flags & SESSION_PFC)
+       {
+               *b++ = type;
+       }
        else
        {
-               *(uint16_t *) b = htons(mtype);
+               *(uint16_t *) b = htons(type);
                b += 2;
        }
 
-       if (l + 12 > size)
+       if (bid)
+       {
+               // Set the sequence number and (B)egin (E)nd flags
+               if (session[s].mssf)
+               {
+                       // Set the multilink bits
+                       uint16_t bits_send = mp_bits;
+                       *(uint16_t *) b = htons((bundle[bid].seq_num_t & 0xFF0F)|bits_send);
+                       b += 2;
+               }
+               else
+               {
+                       *(uint32_t *) b = htonl(bundle[bid].seq_num_t);
+                       // Set the multilink bits
+                       *b = mp_bits;
+                       b += 4;
+               }
+
+               bundle[bid].seq_num_t++;
+
+               // Add the message type if this fragment has the begin bit set
+               if (mp_bits & MP_BEGIN)
+               {
+                       //*b++ = mtype; // The next two lines are instead of this 
+                       *(uint16_t *) b = htons(mtype); // Message type
+                       b += 2;
+               }
+       }
+
+       if ((b - start) + l > 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)
+               LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, (b - start) + l);
                return NULL;
        }
 
+       // Copy the payload
        if (p && l)
                memcpy(b, p, l);
 
@@ -1799,37 +2330,55 @@ static int add_lcp_auth(uint8_t *b, int size, int authtype)
        return len;
 }
 
-// Send initial LCP ConfigReq for MRU, authentication type and magic no
-void sendlcp(sessionidt s, tunnelidt t, int authtype)
+// Send LCP ConfigReq for MRU, authentication type and magic no
+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, s, t, PPPLCP)))
+        if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP, 0, 0, 0)))
                return;
 
-       LOG(3, s, t, "LCP: send ConfigReq%s%s%s\n",
+        LOG(3, s, t, "LCP: send ConfigReq%s%s%s including MP options\n",
            authtype ? " (" : "",
            authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
            authtype ? ")" : "");
 
-       if (!session[s].mru)
-               session[s].mru = DEFAULT_MRU;
-
        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);
 
-       *l++ = 5; *l++ = 6; // Magic-Number (length 6)
-       *(uint32_t *) l = htonl(session[s].magic);
-       l += 4;
+       if (session[s].magic)
+       {
+               *l++ = 5; *l++ = 6; // Magic-Number (length 6)
+               *(uint32_t *) l = htonl(session[s].magic);
+               l += 4;
+       }
+
+        if (sess_local[s].mp_mrru)
+        {
+               *l++ = 17; *l++ = 4; // Multilink Max-Receive-Reconstructed-Unit (length 4)
+               *(uint16_t *) l = htons(sess_local[s].mp_mrru); l += 2;
+       }
+
+        if (sess_local[s].mp_epdis)
+        {
+               *l++ = 19; *l++ = 7;    // Multilink Endpoint Discriminator (length 7)
+               *l++ = IPADDR;  // Endpoint Discriminator class
+               *(uint32_t *) l = htonl(sess_local[s].mp_epdis);
+               l += 4;
+       }
 
        *(uint16_t *)(q + 2) = htons(l - q); // Length
 
@@ -1837,6 +2386,7 @@ void sendlcp(sessionidt s, tunnelidt t, int authtype)
        if (config->debug > 3) dumplcp(q, l - q);
 
        tunnelsend(b, (l - b), t);
+       restart_timer(s, lcp);
 }
 
 // Send CCP request for no compression
@@ -1844,14 +2394,46 @@ void sendccp(sessionidt s, tunnelidt t)
 {
        uint8_t b[500], *q;
 
-       if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPCCP)))
+       if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPCCP, 0, 0, 0)))
                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, 0, 0, 0);
+       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);
 }