fix log message
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index 49f0858..8c1c9a3 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.99 2006-04-18 06:00:08 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 1.99 2006-04-18 06:00:08 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)
@@ -90,7 +96,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                // respond now, either no RADIUS available or already authenticated
                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)
@@ -173,16 +179,24 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                return;
        }
 
-       r = sess_local[s].radius;
-       if (!r)
+       if (session[s].ppp.phase != Authenticate)
        {
-               LOG(3, s, t, "Unexpected CHAP message\n");
+               LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
                return;
        }
 
-       if (session[s].ppp.phase != Authenticate)
+       r = sess_local[s].radius;
+       if (!r)
        {
-               LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
+               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;
        }
 
@@ -352,16 +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);
+               }
        }
 }
 
@@ -379,7 +406,7 @@ static uint8_t *ppp_conf_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t m
 {
        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;
 
@@ -423,7 +450,7 @@ static uint8_t *ppp_conf_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t m
                if (*nak_sent >= config->ppp_max_failure)
                        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;
 
@@ -455,7 +482,7 @@ static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
        l += 4;
        if (l > mru) l = mru;
 
-       q = makeppp(buf, size, 0, 0, s, t, proto);
+       q = makeppp(buf, size, 0, 0, s, t, proto, 0, 0, 0);
        if (!q) return;
 
        *q = CodeRej;
@@ -567,6 +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)
                {
@@ -582,7 +610,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                                if (mru >= MINMTU)
                                                {
                                                        session[s].mru = mru;
-                                                       cluster_send_session(s);
+                                                       changed++;
                                                        break;
                                                }
 
@@ -655,6 +683,64 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                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_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
@@ -663,6 +749,9 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        o += length;
                }
 
+               if (changed)
+                       cluster_send_session(s);
+
                if (response)
                {
                        l = q - response; // LCP packet length
@@ -671,7 +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;
                }
@@ -679,7 +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);
@@ -812,6 +901,50 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                        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);
@@ -835,7 +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);
@@ -893,7 +1026,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                }
 
                *p = TerminateAck;      // send ack
-               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(3, s, t, "LCP: send %s\n", ppp_code(*q));
@@ -929,7 +1062,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                *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));
@@ -947,6 +1080,93 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
 }
 
+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;
+                       }
+               }
+       }
+
+       // No previously created bundle was found for this session, so create a new one
+       if (!(b = new_bundle())) return 0;
+
+       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);
+
+       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;
+}
+
+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)
 {
        LOG(3, s, t, "IPCP: Opened, session is now active\n");
@@ -1105,7 +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;
                }
@@ -1119,7 +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);
@@ -1192,7 +1412,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                }
 
                *p = TerminateAck;      // send ack
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPCP);
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP, 0, 0, 0);
                if (!q) return;
 
                LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q));
@@ -1326,7 +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;
                }
@@ -1340,7 +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);
@@ -1413,7 +1633,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                }
 
                *p = TerminateAck;      // send ack
-               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP);
+               q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP, 0, 0, 0);
                if (!q) return;
 
                LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
@@ -1456,11 +1676,14 @@ 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
@@ -1526,6 +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'.
@@ -1685,7 +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)
@@ -1718,13 +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);
@@ -1770,13 +2154,13 @@ 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);
@@ -1820,7 +2204,7 @@ void sendchap(sessionidt s, tunnelidt t)
                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
@@ -1834,37 +2218,86 @@ void sendchap(sessionidt s, tunnelidt t)
 
 // fill in a L2TP message with a PPP frame,
 // 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!!
        {
                LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
                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].flags & SESSION_ACFC))
+
+       // 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].flags & SESSION_PFC)
-               *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)
        {
-               LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
+               // 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)
+       {
+               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);
 
@@ -1903,10 +2336,10 @@ 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 ? ")" : "");
@@ -1933,6 +2366,20 @@ void sendlcp(sessionidt s, tunnelidt t)
                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
 
        LOG_HEX(5, "PPPLCP", q, l - q);
@@ -1947,7 +2394,7 @@ 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(3, s, t, "CCP: send ConfigReq (no compression)\n");
@@ -1974,7 +2421,7 @@ void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t pro
        l += 6;
        if (l > mru) l = mru;
 
-       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP, 0, 0, 0);
        if (!q) return;
 
        *q = ProtocolRej;