Update changelog.
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index 0b63596..93e360e 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,12 +1,13 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.86 2005-11-17 05:24:17 bodea Exp $";
-
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdlib.h>
+#include <sys/socket.h>
+#include <linux/rtnetlink.h>
+
 #include "l2tpns.h"
 #include "constants.h"
 #include "plugin.h"
@@ -14,16 +15,36 @@ char const *cvs_id_ppp = "$Id: ppp.c,v 1.86 2005-11-17 05:24:17 bodea Exp $";
 #include "tbf.h"
 #include "cluster.h"
 
+#include "l2tplac.h"
+#include "pppoe.h"
+
 extern tunnelt *tunnel;
+extern bundlet *bundle;
+extern fragmentationt *frag;
 extern sessiont *session;
 extern radiust *radius;
 extern int tunfd;
 extern char hostname[];
 extern uint32_t eth_tx;
 extern time_t time_now;
+extern uint64_t time_now_ms;
 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);
+
+static int first_session_in_bundle(sessionidt s)
+{
+       bundleidt i;
+       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))
+                               return 0;
+       return 1;       
+}
 
 // Process PAP messages
 void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
@@ -40,7 +61,7 @@ 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 +69,7 @@ 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 +78,7 @@ 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;
        }
 
@@ -85,12 +106,18 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                LOG(3, s, t, "PAP login %s/%s\n", user, pass);
        }
 
+       if ((!config->disable_lac_func) && lac_conf_forwardtoremotelns(s, user))
+       {
+               // Creating a tunnel/session has been started
+               return;
+       }
+
        if (session[s].ip || !(r = radiusnew(s)))
        {
                // 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)
@@ -110,7 +137,7 @@ 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
@@ -134,7 +161,10 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                radius[r].id = p[1];
                LOG(3, s, t, "Sending login for %s/%s to RADIUS\n", user, pass);
-               radiussend(r, RADIUSAUTH);
+               if ((session[s].mrru) && (!first_session_in_bundle(s)))
+                       radiussend(r, RADIUSJUSTAUTH);
+               else
+                       radiussend(r, RADIUSAUTH);
        }
 }
 
@@ -152,7 +182,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                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;
        }
 
@@ -160,7 +190,7 @@ 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;
@@ -169,20 +199,28 @@ 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;
        }
 
-       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;
        }
 
@@ -190,7 +228,7 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        {
                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;
        }
 
@@ -198,7 +236,7 @@ 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;
        }
 
@@ -208,7 +246,7 @@ 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;
        }
 
@@ -225,6 +263,14 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                packet.username = calloc(l + 1, 1);
                memcpy(packet.username, p, l);
 
+               if ((!config->disable_lac_func) && lac_conf_forwardtoremotelns(s, packet.username))
+               {
+                       free(packet.username);
+                       free(packet.password);
+                       // Creating a tunnel/session has been started
+                       return;
+               }
+
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
                {
@@ -243,7 +289,10 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
        radius[r].chap = 1;
        LOG(3, s, t, "CHAP login %s\n", session[s].user);
-       radiussend(r, RADIUSAUTH);
+       if ((session[s].mrru) && (!first_session_in_bundle(s)))
+               radiussend(r, RADIUSJUSTAUTH);
+       else
+               radiussend(r, RADIUSAUTH);
 }
 
 static void dumplcp(uint8_t *p, int l)
@@ -352,20 +401,29 @@ 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);
-               else
-                       change_state(s, ipv6cp, Closed);
+               if(session[s].bundle == 0 || bundle[session[s].bundle].num_of_links == 1)
+               {
+                       // 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);
+               }
+               else
+               {
+                       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);
+                       ipcp_open(s, t);
+                }
        }
 }
 
-static void lcp_restart(sessionidt s)
+void lcp_restart(sessionidt s)
 {
        session[s].ppp.phase = Establish;
        // This-Layer-Down
@@ -379,7 +437,7 @@ 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 +481,7 @@ 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;
 
@@ -449,12 +507,13 @@ static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
 {
        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);
+       q = makeppp(buf, size, 0, 0, s, t, proto, 0, 0, 0);
        if (!q) return;
 
        *q = CodeRej;
@@ -474,7 +533,6 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
        uint8_t b[MAXETHER];
        uint8_t *q = NULL;
-       uint32_t magicno = 0;
        uint16_t hl;
 
        CSTAT(processlcp);
@@ -498,7 +556,9 @@ 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)
@@ -565,6 +625,7 @@ 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)
                {
@@ -577,9 +638,10 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                case 1: // Maximum-Receive-Unit
                                        {
                                                uint16_t mru = ntohs(*(uint16_t *)(o + 2));
-                                               if (mru >= 576)
+                                               if (mru >= MINMTU)
                                                {
                                                        session[s].mru = mru;
+                                                       changed++;
                                                        break;
                                                }
 
@@ -646,15 +708,70 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                        }
                                        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_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
@@ -663,6 +780,9 @@ 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 +791,7 @@ 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 +799,7 @@ 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);
@@ -720,6 +840,10 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                        break;
 
+               case Closing:
+                       sessionshutdown(s, "LCP: ConfigReq in state Closing. This should not happen. Killing session.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
+                       break;
+
                default:
                        LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                        return;
@@ -747,6 +871,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                case 1: // Maximum-Receive-Unit
                                        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);
                                        }
@@ -764,14 +889,18 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                                        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",
@@ -791,9 +920,70 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                                        break;
 
+                               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);
-                                       break;
+                                       sessionshutdown(s, "Unable to negotiate LCP.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+                                       return;
                        }
                        x -= length;
                        o += length;
@@ -801,7 +991,7 @@ 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;
                }
 
@@ -813,7 +1003,7 @@ 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);
@@ -848,19 +1038,36 @@ 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)
        {
@@ -890,7 +1097,7 @@ 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));
@@ -908,6 +1115,112 @@ 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))
+                       {
+                               sessionidt first_ses = bundle[i].members[0];
+                               if (bundle[i].mssf != session[s].mssf)
+                               {
+                                       // uniformity of sequence number format must be insured
+                                       LOG(3, s, session[s].tunnel, "MPPP: unable to bundle session %d in bundle %d cause of different mssf\n", s, i);
+                                       return -1;
+                               }
+                               session[s].bundle = i;
+                               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;
+
+                               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;
+       // FIXME !!! to enable l2tpns reading mssf frames receiver_max_seq, sender_max_seq must be introduce
+       // now session[s].mssf flag indecates that the receiver wish to receive frames in mssf, so max_seq (i.e. recv_max_seq) = 1<<24
+       /*
+       if (bundle[b].mssf)
+               bundle[b].max_seq = 1 << 12;
+       else */
+               bundle[b].max_seq = 1 << 24;
+       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;
+       bundle[b].timeout = session[s].timeout;
+       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
+                       memset(&frag[i], 0, sizeof(fragmentationt));
+                       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");
@@ -945,7 +1258,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        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);
@@ -1002,11 +1315,13 @@ 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)))
@@ -1015,7 +1330,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                        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;
                                        }
                                }
@@ -1023,7 +1338,7 @@ 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)))
@@ -1035,9 +1350,9 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                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_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
@@ -1064,7 +1379,7 @@ 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;
                }
@@ -1078,7 +1393,7 @@ 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);
@@ -1129,12 +1444,33 @@ 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);
+               switch (session[s].ppp.ipcp)
+               {
+               case Closed:
+               case Stopped:
+               case Closing:
+               case Stopping:
+               case RequestSent:
+               case AckReceived:
+               case AckSent:
+                       break;
+
+               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 = TerminateAck;      // send ack
+               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));
-               tunnelsend(b, l + (q - b), t);
-               change_state(s, ipcp, Stopped);
+               tunnelsend(b, l + (q - b), t); // send it
        }
        else if (*p != CodeRej)
        {
@@ -1223,22 +1559,24 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                uint8_t *o = p + 4;
                int length = l - 4;
                int gotip = 0;
-               uint8_t ident[8];
+               uint32_t ident[2];
 
                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;
+                               ident[0] = htonl(session[s].ip);
+                               ident[1] = 0;
 
                                if (memcmp(o + 2, ident, sizeof(ident)))
                                {
-                                       q = ppp_conf_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, (uint8_t *)ident, sizeof(ident));
                                        if (!q) return;
                                }
 
@@ -1262,7 +1600,7 @@ 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;
                }
@@ -1276,7 +1614,7 @@ 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);
@@ -1327,12 +1665,33 @@ 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);
+               switch (session[s].ppp.ipv6cp)
+               {
+               case Closed:
+               case Stopped:
+               case Closing:
+               case Stopping:
+               case RequestSent:
+               case AckReceived:
+               case AckSent:
+                       break;
+
+               case Opened:
+                       zero_restart_count(s, ipv6cp);
+                       change_state(s, ipv6cp, Closing);
+                       break;
+
+               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(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
-               tunnelsend(b, l + (q - b), t);
-               change_state(s, ipv6cp, Stopped);
+               tunnelsend(b, l + (q - b), t); // send it
        }
        else if (*p != CodeRej)
        {
@@ -1340,6 +1699,39 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
 }
 
+static void update_sessions_in_stat(sessionidt s, uint16_t l)
+{
+       bundleidt b = session[s].bundle;
+       if (!b)
+       {
+               increment_counter(&session[s].cin, &session[s].cin_wrap, l);
+               session[s].cin_delta += l;
+                       session[s].pin++;
+
+               sess_local[s].cin += l;
+               sess_local[s].pin++;
+       }
+       else
+       {
+               int i = frag[b].re_frame_begin_index;
+               int end = frag[b].re_frame_end_index;
+               for (;;)
+               {
+                       l = frag[b].fragment[i].length;
+                       s = frag[b].fragment[i].sid;
+                       increment_counter(&session[s].cin, &session[s].cin_wrap, l);
+                       session[s].cin_delta += l;
+                               session[s].pin++;
+
+                       sess_local[s].cin += l;
+                       sess_local[s].pin++;
+                       if (i == end)
+                               return;
+                       i = (i + 1) & MAXFRAGNUM_MASK;
+               }
+       }
+}
+
 // process IP packet received
 //
 // This MUST be called with at least 4 byte behind 'p'.
@@ -1371,11 +1763,14 @@ 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 (!config->disable_no_spoof && 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
@@ -1395,17 +1790,13 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        *(uint32_t *) p = htonl(PKTIP);
        l += 4;
 
-       // Are we throttled and a slave?
-       if (session[s].tbf_in && !config->cluster_iam_master) {
-               // Pass it to the master for handling.
-               master_throttle_packet(session[s].tbf_in, p, l);
-               return;
-       }
-
-       // Are we throttled and a master??
-       if (session[s].tbf_in && config->cluster_iam_master) {
-               // Actually handle the throttled packets.
-               tbf_queue_packet(session[s].tbf_in, p, l);
+       if (session[s].tbf_in)
+       {
+               // Are we throttling this session?
+               if (config->cluster_iam_master)
+                       tbf_queue_packet(session[s].tbf_in, p, l);
+               else
+                       master_throttle_packet(session[s].tbf_in, p, l);
                return;
        }
 
@@ -1428,12 +1819,7 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
 
-       increment_counter(&session[s].cin, &session[s].cin_wrap, l);
-       session[s].cin_delta += l;
-       session[s].pin++;
-
-       sess_local[s].cin += l;
-       sess_local[s].pin++;
+       update_sessions_in_stat(s, l);
 
        eth_tx += l;
 
@@ -1441,6 +1827,393 @@ 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;
+       bundlet * this_bundle = &bundle[b];
+       uint32_t maskSeq, max_seq;
+       int frag_offset;
+       uint16_t frag_index, frag_index_next, frag_index_prev;
+       fragmentationt *this_fragmentation = &frag[b];
+       uint8_t begin_frame = (*p & MP_BEGIN);
+       uint8_t end_frame = (*p & MP_END);
+       uint32_t seq_num, seq_num_next, seq_num_prev;
+       uint32_t i;
+       uint8_t flags = *p;
+       uint16_t begin_index, end_index;
+
+       // Perform length checking
+       if(l > MAXFRAGLEN)
+       {
+               LOG(2, s, t, "MPPP: discarding fragment larger than MAXFRAGLEN\n");
+               return;
+       }
+
+       if(!b)
+       {
+               LOG(2, s, t, "MPPP: Invalid bundle id: 0\n");
+               return;
+       }
+       // FIXME !! session[s].mssf means that the receiver wants to receive frames in mssf not means the receiver will send frames in mssf
+       /* if(session[s].mssf)
+       {
+               // Get 12 bit for seq number
+               seq_num = ntohs((*(uint16_t *) p) & 0xFF0F);
+               p += 2;
+               l -= 2;
+               // After this point the pointer should be advanced 2 bytes
+               LOG(3, s, t, "MPPP: 12 bits, sequence number: %d\n",seq_num);
+       }
+       else */
+       {
+               // Get 24 bit for seq number
+               seq_num = ntohl((*(uint32_t *) p) & 0xFFFFFF00);
+               p += 4;
+               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);
+       }
+
+       max_seq = this_bundle->max_seq;
+       maskSeq = max_seq - 1;
+
+       /*
+        * Expand sequence number to 32 bits, making it as close
+        * as possible to this_fragmentation->M.
+        */
+       seq_num |= this_fragmentation->M & ~maskSeq;
+       if ((int)(this_fragmentation->M - seq_num) > (int)(maskSeq >> 1))
+       {
+               seq_num += maskSeq + 1;
+       }
+       else if ((int)(seq_num - this_fragmentation->M) > (int)(maskSeq >> 1))
+       {
+               seq_num -= maskSeq + 1; /* should never happen */
+       }
+
+       // calculate this fragment's offset from the begin seq in the bundle
+       frag_offset = (int) (seq_num - this_fragmentation->start_seq);
+       
+       sess_local[s].last_seq = seq_num;
+
+       // calculate the jitter average
+       uint32_t ljitter = time_now_ms - sess_local[s].prev_time;
+       if (ljitter > 0)
+       {
+               sess_local[s].jitteravg = (sess_local[s].jitteravg + ljitter)>>1;
+               sess_local[s].prev_time = time_now_ms;
+       }
+
+       uint32_t Mmin;
+
+       if (seq_num < this_fragmentation->M)
+       {
+               Mmin = seq_num;
+               this_fragmentation->M = seq_num;
+       }
+       else
+       {
+               Mmin = sess_local[(this_bundle->members[0])].last_seq;
+               for (i = 1; i < this_bundle->num_of_links; i++)
+               {
+                       uint32_t s_seq = sess_local[(this_bundle->members[i])].last_seq;
+                       if (s_seq < Mmin)
+                               Mmin = s_seq;
+               }
+               this_fragmentation->M = Mmin;
+       }
+
+       // calculate M offset of the M seq in the bundle
+       int M_offset = (int) (Mmin - this_fragmentation->start_seq);
+
+       if (M_offset >= MAXFRAGNUM)
+       {
+               // There have a long break of the link !!!!!!!!
+               // M_offset is bigger that the fragmentation buffer size
+               LOG(3, s, t, "MPPP: M_offset out of range, min:%d, begin_seq:%d\n", Mmin, this_fragmentation->start_seq);
+
+               // Calculate the new start index, the previous frag are lost
+               begin_index = (M_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+
+               // Set new Start sequence
+               this_fragmentation->start_index = begin_index;
+               this_fragmentation->start_seq = Mmin;
+               M_offset = 0;
+               // recalculate the fragment offset from the new begin seq in the bundle
+               frag_offset = (int) (seq_num - Mmin);
+       }
+
+       // discard this fragment if the packet comes before the start sequence
+       if (frag_offset < 0)
+       {
+               // this packet comes before the next
+               LOG(3, s, t, "MPPP: (COMES BEFORE) the next, seq:%d, begin_seq:%d, size_frag:%d, flags:%02X is LOST\n", seq_num, this_fragmentation->start_seq, l, flags);
+               return;
+       }
+
+       // discard if frag_offset is bigger that the fragmentation buffer size
+       if (frag_offset >= MAXFRAGNUM)
+       {
+               // frag_offset is bigger that the fragmentation buffer size
+               LOG(3, s, t, "MPPP: Index out of range, seq:%d, begin_seq:%d\n", seq_num, this_fragmentation->start_seq);
+               return;
+       }
+
+       //caculate received fragment's index in the fragment array
+       frag_index = (frag_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+
+       // insert the frame in it's place
+       fragmentt *this_frag = &this_fragmentation->fragment[frag_index];
+
+       if (this_frag->length > 0)
+               // This fragment is lost, It was around the buffer and it was never completed the packet.
+               LOG(3, this_frag->sid, this_frag->tid, "MPPP: (INSERT) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                       this_frag->seq, frag_index, this_frag->flags);
+
+       this_frag->length = l;
+       this_frag->sid = s;
+       this_frag->tid = t;
+       this_frag->flags = flags;
+       this_frag->seq = seq_num;
+       this_frag->jitteravg = sess_local[s].jitteravg;
+       memcpy(this_frag->data, p, l);
+
+       LOG(4, s, t, "MPPP: seq_num:%d frag_index:%d INSERTED flags: %02X\n",  seq_num, frag_index, flags);
+
+       //next frag index
+       frag_index_next = (frag_index + 1) & MAXFRAGNUM_MASK;
+       //previous frag index
+       frag_index_prev = (frag_index - 1) & MAXFRAGNUM_MASK;
+       // next seq
+       seq_num_next = seq_num + 1;
+       // previous seq
+       seq_num_prev = seq_num - 1;
+
+       // Clean the buffer and log the lost fragments
+       if ((frag_index_next != this_fragmentation->start_index) && this_fragmentation->fragment[frag_index_next].length)
+       {
+               // check if the next frag is a lost fragment
+               if (this_fragmentation->fragment[frag_index_next].seq != seq_num_next)
+               {
+                       // This fragment is lost, It was around the buffer and it was never completed the packet.
+                       LOG(3, this_fragmentation->fragment[frag_index_next].sid, this_fragmentation->fragment[frag_index_next].tid,
+                               "MPPP: (NEXT) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                               this_fragmentation->fragment[frag_index_next].seq, frag_index_next,
+                               this_fragmentation->fragment[frag_index_next].flags);
+                       // this frag is lost
+                       this_fragmentation->fragment[frag_index_next].length = 0;
+                       this_fragmentation->fragment[frag_index_next].flags = 0;
+
+                       if (begin_frame && (!end_frame)) return; // assembling frame failed
+               }
+       }
+
+       // Clean the buffer and log the lost fragments
+       if ((frag_index != this_fragmentation->start_index) && this_fragmentation->fragment[frag_index_prev].length)
+       {
+               // check if the next frag is a lost fragment
+               if (this_fragmentation->fragment[frag_index_prev].seq != seq_num_prev)
+               {
+                       // This fragment is lost, It was around the buffer and it was never completed the packet.
+                       LOG(3, this_fragmentation->fragment[frag_index_prev].sid, this_fragmentation->fragment[frag_index_prev].tid,
+                               "MPPP: (PREV) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                               this_fragmentation->fragment[frag_index_prev].seq, frag_index_prev,
+                               this_fragmentation->fragment[frag_index_prev].flags);
+
+                       this_fragmentation->fragment[frag_index_prev].length = 0;
+                       this_fragmentation->fragment[frag_index_prev].flags = 0;
+
+                       if (end_frame && (!begin_frame)) return; // assembling frame failed
+               }
+       }
+
+find_frame:
+       begin_index = this_fragmentation->start_index;
+       uint32_t b_seq = this_fragmentation->start_seq;
+       // Try to find a Begin sequence from the start_seq sequence to M sequence
+       while (b_seq < Mmin)
+       {
+               if (this_fragmentation->fragment[begin_index].length)
+               {
+                       if (b_seq == this_fragmentation->fragment[begin_index].seq)
+                       {
+                               if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
+                               {
+                                       int isfoundE = 0;
+                                       // Adjust the new start sequence and start index
+                                       this_fragmentation->start_index = begin_index;
+                                       this_fragmentation->start_seq = b_seq;
+                                       // Begin Sequence found, now try to found the End Sequence to complete the frame
+                                       end_index = begin_index;
+                                       while (b_seq < Mmin)
+                                       {
+                                               if (this_fragmentation->fragment[end_index].length)
+                                               {
+                                                       if (b_seq == this_fragmentation->fragment[end_index].seq)
+                                                       {
+                                                               if (this_fragmentation->fragment[end_index].flags & MP_END)
+                                                               {
+                                                                       // The End sequence was found and the frame is complete
+                                                                       isfoundE = 1;
+                                                                       break;
+                                                               }
+                                                       }
+                                                       else
+                                                       {
+                                                               // This fragment is lost, it was never completed the packet.
+                                                               LOG(3, this_fragmentation->fragment[end_index].sid, this_fragmentation->fragment[end_index].tid,
+                                                                       "MPPP: (FIND END) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                                                                       this_fragmentation->fragment[end_index].seq, begin_index,
+                                                                       this_fragmentation->fragment[end_index].flags);
+                                                               // this frag is lost
+                                                               this_fragmentation->fragment[end_index].length = 0;
+                                                               this_fragmentation->fragment[end_index].flags = 0;
+                                                               // This frame is not complete find the next Begin
+                                                               break;
+                                                       }
+                                               }
+                                               else
+                                               {
+                                                       // This frame is not complete find the next Begin if exist
+                                                       break;
+                                               }
+                                               end_index = (end_index +1) & MAXFRAGNUM_MASK;
+                                               b_seq++;
+                                       }
+
+                                       if (isfoundE)
+                                               // The End sequence was found and the frame is complete
+                                               break;
+                                       else
+                                               // find the next Begin
+                                               begin_index = end_index;
+                               }
+                       }
+                       else
+                       {
+                               // This fragment is lost, it was never completed the packet.
+                               LOG(3, this_fragmentation->fragment[begin_index].sid, this_fragmentation->fragment[begin_index].tid,
+                                       "MPPP: (FIND BEGIN) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                                       this_fragmentation->fragment[begin_index].seq, begin_index,
+                                       this_fragmentation->fragment[begin_index].flags);
+                               // this frag is lost
+                               this_fragmentation->fragment[begin_index].length = 0;
+                               this_fragmentation->fragment[begin_index].flags = 0;
+                       }
+               }
+               begin_index = (begin_index +1) & MAXFRAGNUM_MASK;
+               b_seq++;
+       }
+
+assembling_frame:
+       // try to assemble the frame that has the received fragment as a member
+       // get the beginning of this frame
+       begin_index = end_index = this_fragmentation->start_index;
+       if (this_fragmentation->fragment[begin_index].length)
+       {
+               if (!(this_fragmentation->fragment[begin_index].flags & MP_BEGIN))
+               {
+                       LOG(3, this_fragmentation->fragment[begin_index].sid, this_fragmentation->fragment[begin_index].tid,
+                               "MPPP: (NOT BEGIN) seq_num:%d frag_index:%d flags:%02X\n",
+                               this_fragmentation->fragment[begin_index].seq, begin_index,
+                               this_fragmentation->fragment[begin_index].flags);
+                       // should occur only after an "M_Offset out of range"
+                       // The start sequence must be a begin sequence
+                       this_fragmentation->start_index = (begin_index +1) & MAXFRAGNUM_MASK;
+                       this_fragmentation->start_seq++;
+                       return; // assembling frame failed
+               }
+       }
+       else
+               return; // assembling frame failed
+
+       // get the end of his frame
+       while (this_fragmentation->fragment[end_index].length)
+       {
+               if (this_fragmentation->fragment[end_index].flags & MP_END)
+                       break;
+
+               end_index = (end_index +1) & MAXFRAGNUM_MASK;
+
+               if (end_index == this_fragmentation->start_index)
+                       return; // assembling frame failed
+       }
+
+       // return if a lost fragment is found
+       if (!(this_fragmentation->fragment[end_index].length))
+               return; // assembling frame failed
+
+       // assemble the packet
+       //assemble frame, process it, reset fragmentation
+       uint16_t cur_len = 4;   // This is set to 4 to leave 4 bytes for function processipin
+
+       LOG(4, s, t, "MPPP: processing fragments from %d to %d\n", begin_index, end_index);
+       // Push to the receive buffer
+
+       for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)
+       {
+               this_frag = &this_fragmentation->fragment[i];
+               if(cur_len + this_frag->length > MAXETHER)
+               {
+                       LOG(2, s, t, "MPPP: discarding reassembled frames larger than MAXETHER\n");
+                       break;
+               }
+
+               memcpy(this_fragmentation->reassembled_frame+cur_len, this_frag->data, this_frag->length);
+               LOG(5, s, t, "MPPP: processing frame at %d, with len %d\n", i, this_frag->length);
+
+               cur_len += this_frag->length;
+               if (i == end_index)
+               {
+                       this_fragmentation->re_frame_len = cur_len;
+                       this_fragmentation->re_frame_begin_index = begin_index;
+                       this_fragmentation->re_frame_end_index = end_index;
+                       // Process the resassembled frame
+                       LOG(5, s, t, "MPPP: Process the reassembled frame, len=%d\n",cur_len);
+                       processmpframe(s, t, this_fragmentation->reassembled_frame, this_fragmentation->re_frame_len, 1);
+                       break;
+               }
+       }
+
+       // Set reassembled frame length to zero after processing it
+       this_fragmentation->re_frame_len = 0;
+       for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)
+       {
+               this_fragmentation->fragment[i].length = 0;      // Indicates that this fragment has been consumed
+               this_fragmentation->fragment[i].flags = 0;
+               if (i == end_index)
+                       break;
+       }
+
+       // Set the new start_index and start_seq
+       this_fragmentation->start_index = (end_index + 1) & MAXFRAGNUM_MASK;
+       this_fragmentation->start_seq = this_fragmentation->fragment[end_index].seq + 1;
+       LOG(4, s, t, "MPPP after assembling: start index is = %d, start seq=%d\n", this_fragmentation->start_index, this_fragmentation->start_seq);
+
+       begin_index = this_fragmentation->start_index;
+       if ((this_fragmentation->fragment[begin_index].length) &&
+               (this_fragmentation->fragment[begin_index].seq != this_fragmentation->start_seq))
+       {
+               LOG(3, this_fragmentation->fragment[begin_index].sid, this_fragmentation->fragment[begin_index].tid,
+                               "MPPP: (START) seq_num:%d frag_index:%d flags:%02X is LOST\n",
+                               this_fragmentation->fragment[begin_index].seq, begin_index,
+                               this_fragmentation->fragment[begin_index].flags);
+                       this_fragmentation->fragment[begin_index].length = 0;
+                       this_fragmentation->fragment[begin_index].flags = 0;
+       }
+
+       if (this_fragmentation->start_seq <= Mmin)
+               // It's possible to find other complete frame or lost frame.
+               goto find_frame;
+       else if ((this_fragmentation->fragment[begin_index].length) &&
+                         (this_fragmentation->fragment[begin_index].flags & MP_BEGIN))
+               // may be that the next frame is completed
+               goto assembling_frame;
+
+       return;
+}
+
 // process IPv6 packet received
 //
 // This MUST be called with at least 4 byte behind 'p'.
@@ -1468,7 +2241,7 @@ void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                return;
 
        // no spoof
-       if (ipv4 != session[s].ip && memcmp(&config->ipv6_prefix, &ip, 8) && sessionbyipv6(ip) != s)
+       if ((ipv4 != session[s].ip || memcmp(&config->ipv6_prefix, &ip, 8)) && sessionbyipv6(ip) != s)
        {
                char str[INET6_ADDRSTRLEN];
                LOG(5, s, t, "Dropping packet with spoofed IP %s\n",
@@ -1524,12 +2297,7 @@ void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
 
-       increment_counter(&session[s].cin, &session[s].cin_wrap, l);
-       session[s].cin_delta += l;
-       session[s].pin++;
-
-       sess_local[s].cin += l;
-       sess_local[s].pin++;
+       update_sessions_in_stat(s, l);
 
        eth_tx += l;
 
@@ -1600,7 +2368,7 @@ 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)
@@ -1633,13 +2401,13 @@ 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);
@@ -1685,13 +2453,13 @@ 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);
@@ -1731,66 +2499,194 @@ 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
        q[1] = radius[r].id;                    // ID
        q[4] = 16;                              // value size (size of challenge)
        memcpy(q + 5, radius[r].auth, 16);      // challenge
-       strcpy((char *) q + 21, hostname);      // our name
-       *(uint16_t *) (q + 2) = htons(strlen(hostname) + 21); // length
-       tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it
+       strcpy((char *) q + 21, config->multi_n_hostname[tunnel[t].indexudp][0]?config->multi_n_hostname[tunnel[t].indexudp]:hostname); // our name
+       *(uint16_t *) (q + 2) = htons(strlen(config->multi_n_hostname[tunnel[t].indexudp][0]?config->multi_n_hostname[tunnel[t].indexudp]:hostname) + 21); // length
+       tunnelsend(b, strlen(config->multi_n_hostname[tunnel[t].indexudp][0]?config->multi_n_hostname[tunnel[t].indexudp]:hostname) + 21 + (q - b), t); // send it
 }
 
 // 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 (t == TUNNEL_ID_PPPOE)
+       {
+               return pppoe_makeppp(b, size, p, l, s, t, mtype, prio, bid, mp_bits);
+       }
+
+       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].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)
        {
-               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)
+               // 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 & 0x0FFF)|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=%td)\n", size, (b - start) + l);
                return NULL;
        }
 
+       // Copy the payload
        if (p && l)
                memcpy(b, p, l);
 
        return b;
 }
 
+// fill in a L2TP message with a PPP frame,
+// returns start of PPP frame
+//(note: THIS ROUTINE CAN WRITES TO p[-28]).
+uint8_t *opt_makeppp(uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits)
+{
+       uint16_t hdr = 0x0002; // L2TP with no options
+       uint16_t type = mtype;
+       uint8_t *b = p;
+
+       if (t == TUNNEL_ID_PPPOE)
+       {
+               return opt_pppoe_makeppp(p, l, s, t, mtype, prio, bid, mp_bits);
+       }
+
+       // 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 (bid)
+       {
+               // Add the message type if this fragment has the begin bit set
+               if (mp_bits & MP_BEGIN)
+               {
+                       b -= 2;
+                       *(uint16_t *) b = htons(mtype); // Message type
+               }
+
+               // Set the sequence number and (B)egin (E)nd flags
+               if (session[s].mssf)
+               {
+                       // Set the multilink bits
+                       uint16_t bits_send = mp_bits;
+                       b -= 2;
+                       *(uint16_t *) b = htons((bundle[bid].seq_num_t & 0x0FFF)|bits_send);
+               }
+               else
+               {
+                       b -= 4;
+                       *(uint32_t *) b = htonl(bundle[bid].seq_num_t);
+                       // Set the multilink bits
+                       *b = mp_bits;
+               }
+
+               bundle[bid].seq_num_t++;
+       }
+
+       if (type < 0x100 && session[s].flags & SESSION_PFC)
+       {
+               b--;
+               *b = type;
+       }
+       else
+       {
+               b -= 2;
+               *(uint16_t *) b = htons(type);
+       }
+
+       if (type == PPPLCP || !(session[s].flags & SESSION_ACFC))
+       {
+               b -= 2;
+               *(uint16_t *) b = htons(0xFF03); // HDLC header
+       }
+
+       if (prio) hdr |= 0x0100; // set priority bit
+       b -= 2;
+       *(uint16_t *) b = htons(session[s].far); // session
+       b -= 2;
+       *(uint16_t *) b = htons(tunnel[t].far); // tunnel
+       b -= 2;
+       *(uint16_t *) b = htons(hdr);
+
+       return b;
+}
+
 static int add_lcp_auth(uint8_t *b, int size, int authtype)
 {
        int len = 0;
@@ -1817,16 +2713,16 @@ 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
+// 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 ? ")" : "");
@@ -1846,9 +2742,26 @@ void sendlcp(sessionidt s, tunnelidt t)
        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
 
@@ -1864,7 +2777,7 @@ 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");
@@ -1877,3 +2790,33 @@ void sendccp(sessionidt s, tunnelidt t)
        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);
+}