Fix the strange bundles' members looping use.
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index 078696d..7be79ce 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.23 2004/11/09 05:42:53 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.104 2009/12/08 14:49:28 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -15,100 +15,128 @@ char const *cvs_id_ppp = "$Id: ppp.c,v 1.23 2004/11/09 05:42:53 bodea Exp $";
 #include "cluster.h"
 
 extern tunnelt *tunnel;
+extern bundlet *bundle;
+extern fragmentationt *frag;
 extern sessiont *session;
 extern radiust *radius;
 extern int tunfd;
 extern char hostname[];
-extern u32 eth_tx;
+extern uint32_t eth_tx;
 extern time_t time_now;
-extern struct configt *config;
+extern configt *config;
 
-void sendccp(tunnelidt t, sessionidt s);
+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(tunnelidt t, sessionidt s, u8 *p, u16 l)
+void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       char user[129];
-       char pass[129];
-       u16 hl;
+       char user[MAXUSER];
+       char pass[MAXPASS];
+       uint16_t hl;
+       uint16_t r;
 
-       CSTAT(call_processpap);
+       CSTAT(processpap);
 
        LOG_HEX(5, "PAP", p, l);
        if (l < 4)
        {
-               LOG(1, 0, s, t, "Short PAP %u bytes\n", l);
+               LOG(1, s, t, "Short PAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Short PAP packet.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
 
-       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
        {
-               LOG(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l);
+               LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "PAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
        l = hl;
 
        if (*p != 1)
        {
-               LOG(1, 0, s, t, "Unexpected PAP code %d\n", *p);
+               LOG(1, s, t, "Unexpected PAP code %d\n", *p);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Unexpected PAP code.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
+       }
+
+       if (session[s].ppp.phase != Authenticate)
+       {
+               LOG(2, s, t, "PAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
+               return;
        }
 
        {
-               u8 *b = p;
+               uint8_t *b = p;
                b += 4;
+               user[0] = pass[0] = 0;
                if (*b && *b < sizeof(user))
+               {
                        memcpy(user, b + 1, *b);
-               user[*b] = 0;
-               b += 1 + *b;
-               if (*b && *b < sizeof(pass))
-                       memcpy(pass, b + 1, *b);
-               pass[*b] = 0;
-               LOG(3, 0, s, t, "PAP login %s/%s\n", user, pass);
+                       user[*b] = 0;
+                       b += 1 + *b;
+                       if (*b && *b < sizeof(pass))
+                       {
+                               memcpy(pass, b + 1, *b);
+                               pass[*b] = 0;
+                       }
+               }
+               LOG(3, s, t, "PAP login %s/%s\n", user, pass);
        }
-       if (session[s].ip || !session[s].radius)
+
+       if (session[s].ip || !(r = radiusnew(s)))
        {
                // respond now, either no RADIUS available or already authenticated
-               u8 b[MAXCONTROL];
-               u8 id = p[1];
-               u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
-               if (!p) {       // Failed to make ppp header!
-                       LOG(1,0,0,0, "Failed to make PPP header in process pap!\n");
-                       return;
-               }
+               uint8_t b[MAXETHER];
+               uint8_t id = p[1];
+               uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP, 0, 0, 0);
+               if (!p) return;
+
                if (session[s].ip)
-                       *p = 2;                 // ACK
+                       *p = 2;                         // ACK
                else
-                       *p = 3;                 // cant authorise
+                       *p = 3;                         // cant authorise
                p[1] = id;
-               *(u16 *) (p + 2) = htons(5);    // length
-               p[4] = 0;                       // no message
+               *(uint16_t *) (p + 2) = htons(5);       // length
+               p[4] = 0;                               // no message
+               tunnelsend(b, 5 + (p - b), t);          // send it
+
                if (session[s].ip)
                {
-                       LOG(3, session[s].ip, s, t, "Already an IP allocated: %s (%d)\n", inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
-                       session[s].flags &= ~SF_IPCP_ACKED;
+                       LOG(3, s, t, "Already an IP allocated: %s (%d)\n",
+                               fmtaddr(htonl(session[s].ip), 0), session[s].ip_pool_index);
                }
                else
                {
-                       LOG(1, 0, s, t, "No radius session available to authenticate session...\n");
+                       LOG(1, s, t, "No RADIUS session available to authenticate session...\n");
+                       sessionshutdown(s, "No free RADIUS sessions.", CDN_UNAVAILABLE, TERM_SERVICE_UNAVAILABLE);
                }
-               LOG(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
-               tunnelsend(b, 5 + (p - b), t); // send it
        }
        else
        {
-               // set up RADIUS request
-               u16 r = session[s].radius;
-
                // Run PRE_AUTH plugins
                struct param_pre_auth packet = { &tunnel[t], &session[s], strdup(user), strdup(pass), PPPPAP, 1 };
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
                {
-                       LOG(3, 0, s, t, "A plugin rejected PRE_AUTH\n");
+                       LOG(3, s, t, "A plugin rejected PRE_AUTH\n");
                        if (packet.username) free(packet.username);
                        if (packet.password) free(packet.password);
                        return;
@@ -121,73 +149,94 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
                free(packet.password);
 
                radius[r].id = p[1];
-               LOG(3, 0, s, t, "Sending login for %s/%s to radius\n", user, pass);
-               radiussend(r, RADIUSAUTH);
+               LOG(3, s, t, "Sending login for %s/%s to RADIUS\n", user, pass);
+               if ((session[s].mrru) && (!first_session_in_bundle(s)))
+                       radiussend(r, RADIUSJUSTAUTH);
+               else
+                       radiussend(r, RADIUSAUTH);
        }
 }
 
 // Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
+void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       u16 r;
-       u16 hl;
+       uint16_t r;
+       uint16_t hl;
 
-       CSTAT(call_processchap);
+       CSTAT(processchap);
 
        LOG_HEX(5, "CHAP", p, l);
-       r = session[s].radius;
-       if (!r)
-       {
-               LOG(1, 0, s, t, "Unexpected CHAP message\n");
-
-// FIXME: Need to drop the session here.
-
-               STAT(tunnel_rx_errors);
-               return;
-       }
 
        if (l < 4)
        {
-               LOG(1, 0, s, t, "Short CHAP %u bytes\n", l);
+               LOG(1, s, t, "Short CHAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Short CHAP packet.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
 
-       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
        {
-               LOG(1, 0, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
+               LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "CHAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
        l = hl;
 
        if (*p != 2)
        {
-               LOG(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
+               LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
                STAT(tunnel_rx_errors);
+               sessionshutdown(s, "CHAP length mismatch.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
+       }
+
+       if (session[s].ppp.phase != Authenticate)
+       {
+               LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
+               return;
+       }
+
+       r = sess_local[s].radius;
+       if (!r)
+       {
+               LOG(3, s, t, "Unexpected CHAP message\n");
+
+               // Some modems (Netgear DM602, possibly others) persist in using CHAP even
+               // after ACKing our ConfigReq for PAP.
+               if (sess_local[s].lcp_authtype == AUTHPAP && config->radius_authtypes & AUTHCHAP)
+               {
+                       sess_local[s].lcp_authtype = AUTHCHAP;
+                       sendchap(s, t);
+               }
                return;
        }
+
        if (p[1] != radius[r].id)
        {
-               LOG(1, 0, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
+               LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Unexpected CHAP response ID.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
 
        if (l < 5 || p[4] != 16)
        {
-               LOG(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
+               LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Bad CHAP response length.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
 
        l -= 5;
        p += 5;
        if (l < 16 || l - 16 >= sizeof(session[s].user))
        {
-               LOG(1, 0, s, t, "CHAP user too long %d\n", l - 16);
+               LOG(1, s, t, "CHAP user too long %d\n", l - 16);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "CHAP username too long.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+               return;
        }
 
        // Run PRE_AUTH plugins
@@ -206,7 +255,7 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
                {
-                       LOG(3, 0, s, t, "A plugin rejected PRE_AUTH\n");
+                       LOG(3, s, t, "A plugin rejected PRE_AUTH\n");
                        if (packet.username) free(packet.username);
                        if (packet.password) free(packet.password);
                        return;
@@ -220,34 +269,21 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
        }
 
        radius[r].chap = 1;
-       LOG(3, 0, s, t, "CHAP login %s\n", session[s].user);
-       radiussend(r, RADIUSAUTH);
+       LOG(3, s, t, "CHAP login %s\n", session[s].user);
+       if ((session[s].mrru) && (!first_session_in_bundle(s)))
+               radiussend(r, RADIUSJUSTAUTH);
+       else
+               radiussend(r, RADIUSAUTH);
 }
 
-char *ppp_lcp_types[] = {
-       NULL,
-       "ConfigReq",
-       "ConfigAck",
-       "ConfigNak",
-       "ConfigRej",
-       "TerminateReq",
-       "TerminateAck",
-       "CodeRej",
-       "ProtocolRej",
-       "EchoReq",
-       "EchoReply",
-       "DiscardRequest",
-       "IdentRequest",
-};
-
-void dumplcp(u8 *p, int l)
+static void dumplcp(uint8_t *p, int l)
 {
        int x = l - 4;
-       u8 *o = (p + 4);
+       uint8_t *o = (p + 4);
 
        LOG_HEX(5, "PPP LCP Packet", p, l);
-       LOG(4, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
-       LOG(4, 0, 0, 0, "Length: %d\n", l);
+       LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_code((int)*p), ntohs( ((uint16_t *) p)[1]) );
+       LOG(4, 0, 0, "Length: %d\n", l);
        if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck)
                return;
 
@@ -257,12 +293,12 @@ void dumplcp(u8 *p, int l)
                int length = o[1];
                if (length < 2)
                {
-                       LOG(4, 0, 0, 0, "       Option length is %d...\n", length);
+                       LOG(4, 0, 0, "  Option length is %d...\n", length);
                        break;
                }
                if (type == 0)
                {
-                       LOG(4, 0, 0, 0, "       Option type is 0...\n");
+                       LOG(4, 0, 0, "  Option type is 0...\n");
                        x -= length;
                        o += length;
                        continue;
@@ -271,51 +307,57 @@ void dumplcp(u8 *p, int l)
                {
                        case 1: // Maximum-Receive-Unit
                                if (length == 4)
-                                       LOG(4, 0, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+                                       LOG(4, 0, 0, "    %s %d\n", ppp_lcp_option(type), ntohs(*(uint16_t *)(o + 2)));
                                else
-                                       LOG(4, 0, 0, 0, "    %s odd length %d\n", lcp_types[type], length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 2: // Async-Control-Character-Map
                                if (length == 6)
                                {
-                                       u32 asyncmap = ntohl(*(u32 *)(o + 2));
-                                       LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], asyncmap);
+                                       uint32_t asyncmap = ntohl(*(uint32_t *)(o + 2));
+                                       LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), asyncmap);
                                }
                                else
-                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 3: // Authentication-Protocol
                                if (length == 4)
                                {
-                                       int proto = ntohs(*(u16 *)(o + 2));
-                                       LOG(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
-                                               proto == PPPCHAP ? "CHAP" :
-                                               proto == PPPPAP  ? "PAP"  : "UNKNOWN");
+                                       int proto = ntohs(*(uint16_t *)(o + 2));
+                                       LOG(4, 0, 0, "    %s 0x%x (%s)\n", ppp_lcp_option(type), proto,
+                                               proto == PPPPAP  ? "PAP"  : "UNSUPPORTED");
+                               }
+                               else if (length == 5)
+                               {
+                                       int proto = ntohs(*(uint16_t *)(o + 2));
+                                       int algo = *(o + 4);
+                                       LOG(4, 0, 0, "    %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo,
+                                               (proto == PPPCHAP && algo == 5) ? "CHAP MD5"  : "UNSUPPORTED");
                                }
                                else
-                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 4: // Quality-Protocol
                                {
-                                       u32 qp = ntohl(*(u32 *)(o + 2));
-                                       LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], qp);
+                                       uint32_t qp = ntohl(*(uint32_t *)(o + 2));
+                                       LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), qp);
                                }
                                break;
                        case 5: // Magic-Number
                                if (length == 6)
                                {
-                                       u32 magicno = ntohl(*(u32 *)(o + 2));
-                                       LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
+                                       uint32_t magicno = ntohl(*(uint32_t *)(o + 2));
+                                       LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), magicno);
                                }
                                else
-                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                                       LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
                                break;
                        case 7: // Protocol-Field-Compression
                        case 8: // Address-And-Control-Field-Compression
-                               LOG(4, 0, 0, 0, "    %s\n", lcp_types[type]);
+                               LOG(4, 0, 0, "    %s\n", ppp_lcp_option(type));
                                break;
                        default:
-                               LOG(2, 0, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
+                               LOG(2, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
                                break;
                }
                x -= length;
@@ -323,403 +365,1698 @@ void dumplcp(u8 *p, int l)
        }
 }
 
+void lcp_open(sessionidt s, tunnelidt t)
+{
+       // transition to Authentication or Network phase: 
+       session[s].ppp.phase = sess_local[s].lcp_authtype ? Authenticate : Network;
+
+       LOG(3, s, t, "LCP: Opened, phase %s\n", ppp_phase(session[s].ppp.phase));
+
+       // LCP now Opened
+       change_state(s, lcp, Opened);
+
+       if (session[s].ppp.phase == Authenticate)
+       {
+               if (sess_local[s].lcp_authtype == AUTHCHAP)
+                       sendchap(s, t);
+       }
+       else
+       {
+               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);
+               }
+               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)
+{
+       session[s].ppp.phase = Establish;
+       // This-Layer-Down
+       change_state(s, ipcp, Dead);
+       change_state(s, ipv6cp, Dead);
+       change_state(s, ccp, Dead);
+}
+
+static uint8_t *ppp_conf_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+       uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option)
+{
+       if (!*response || **response != ConfigRej)
+       {
+               queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype, 0, 0, 0);
+               if (!queued)
+                       return 0;
+
+               *queued = ConfigRej;
+               queued += 4;
+       }
+
+       if ((queued - buf + option[1]) > blen)
+       {
+               LOG(2, s, session[s].tunnel, "PPP overflow for ConfigRej (proto %u, option %u).\n", mtype, *option);
+               return 0;
+       }
+
+       memcpy(queued, option, option[1]);
+       return queued + option[1];
+}
+
+static uint8_t *ppp_conf_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+       uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option,
+       uint8_t *value, size_t vlen)
+{
+       int *nak_sent;
+       switch (mtype)
+       {
+       case PPPLCP:    nak_sent = &sess_local[s].lcp.nak_sent;    break;
+       case PPPIPCP:   nak_sent = &sess_local[s].ipcp.nak_sent;   break;
+       case PPPIPV6CP: nak_sent = &sess_local[s].ipv6cp.nak_sent; break;
+       default:        return 0; // ?
+       }
+
+       if (*response && **response != ConfigNak)
+       {
+               if (*nak_sent < config->ppp_max_failure) // reject queued
+                       return queued;
+
+               return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
+       }
+
+       if (!*response)
+       {
+               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, 0, 0, 0);
+               if (!queued)
+                       return 0;
+
+               (*nak_sent)++;
+               *queued = ConfigNak;
+               queued += 4;
+       }
+
+       if ((queued - buf + vlen + 2) > blen)
+       {
+               LOG(2, s, session[s].tunnel, "PPP overflow for ConfigNak (proto %u, option %u).\n", mtype, *option);
+               return 0;
+       }
+
+       *queued++ = *option;
+       *queued++ = vlen + 2;
+       memcpy(queued, value, vlen);
+       return queued + vlen;
+}
+
+static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
+       char *pname, uint8_t *p, uint16_t l, uint8_t *buf, size_t size)
+{
+       uint8_t *q;
+       int mru = session[s].mru;
+       if (mru < MINMTU) mru = MINMTU;
+       if (mru > size) mru = size;
+
+       l += 4;
+       if (l > mru) l = mru;
+
+       q = makeppp(buf, size, 0, 0, s, t, proto, 0, 0, 0);
+       if (!q) return;
+
+       *q = CodeRej;
+       *(q + 1) = ++sess_local[s].lcp_ident;
+       *(uint16_t *)(q + 2) = htons(l);
+       memcpy(q + 4, p, l - 4);
+
+       LOG(2, s, t, "Unexpected %s code %s\n", pname, ppp_code(*p));
+       LOG(3, s, t, "%s: send %s\n", pname, ppp_code(*q));
+       if (config->debug > 3) dumplcp(q, l);
+
+       tunnelsend(buf, l + (q - buf), t);
+}
+
 // Process LCP messages
-void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
+void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       u8 b[MAXCONTROL];
-       u8 *q = NULL;
-       u32 magicno = 0;
-       u16 hl;
+       uint8_t b[MAXETHER];
+       uint8_t *q = NULL;
+       uint16_t hl;
 
-       CSTAT(call_processlcp);
+       CSTAT(processlcp);
 
        LOG_HEX(5, "LCP", p, l);
        if (l < 4)
        {
-               LOG(1, session[s].ip, s, t, "Short LCP %d bytes\n", l);
+               LOG(1, s, t, "Short LCP %d bytes\n", l);
                STAT(tunnel_rx_errors);
                return ;
        }
 
-       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
        {
-               LOG(1, 0, s, t, "Length mismatch LCP %u/%u\n", hl, l);
+               LOG(1, s, t, "Length mismatch LCP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
                return ;
        }
        l = hl;
 
+       if (session[s].die) // going down...
+               return;
+
+       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)
-       {
-               LOG(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
-               session[s].flags |= SF_LCP_ACKED;
-       }
-       else if (*p == ConfigReq)
        {
                int x = l - 4;
-               u8 *o = (p + 4);
-               u8 response = 0;
-
-               LOG(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
-               if (config->debug > 3) dumplcp(p, l);
+               uint8_t *o = (p + 4);
+               int authtype = 0;
 
                while (x > 2)
                {
                        int type = o[0];
                        int length = o[1];
+
                        if (length == 0 || type == 0 || x < length) break;
                        switch (type)
                        {
-                               case 1: // Maximum-Receive-Unit
-                                       session[s].mru = ntohs(*(u16 *)(o + 2));
+                               case 3: // Authentication-Protocol
+                                       {
+                                               int proto = ntohs(*(uint16_t *)(o + 2));
+                                               if (proto == PPPPAP)
+                                                       authtype = AUTHPAP;
+                                               else if (proto == PPPCHAP && *(o + 4) == 5)
+                                                       authtype = AUTHCHAP;
+                                       }
+
                                        break;
+                       }
+                       x -= length;
+                       o += length;
+               }
 
-                               case 2: // Async-Control-Character-Map
-                                       if (!ntohl(*(u32 *)(o + 2))) // all bits zero is OK
-                                               break;
+               if (!session[s].ip && authtype)
+                       sess_local[s].lcp_authtype = authtype;
 
-                                       if (response && response != ConfigNak) // rej already queued
-                                               break;
+               switch (session[s].ppp.lcp)
+               {
+               case RequestSent:
+                       initialise_restart_count(s, lcp);
+                       change_state(s, lcp, AckReceived);
+                       break;
+
+               case AckReceived:
+               case Opened:
+                       LOG(2, s, t, "LCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
+                       if (session[s].ppp.lcp == Opened)
+                               lcp_restart(s);
+
+                       sendlcp(s, t);
+                       change_state(s, lcp, RequestSent);
+                       break;
+
+               case AckSent:
+                       lcp_open(s, t);
+                       break;
+
+               default:
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+               }
+       }
+       else if (*p == ConfigReq)
+       {
+               int x = l - 4;
+               uint8_t *o = (p + 4);
+               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)
+               {
+                       int type = o[0];
+                       int length = o[1];
 
-                                       LOG(2, session[s].ip, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
-                                       if (!response)
+                       if (length == 0 || type == 0 || x < length) break;
+                       switch (type)
+                       {
+                               case 1: // Maximum-Receive-Unit
                                        {
-                                               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                                               if (!q)
+                                               uint16_t mru = ntohs(*(uint16_t *)(o + 2));
+                                               if (mru >= MINMTU)
                                                {
-                                                       LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
+                                                       session[s].mru = mru;
+                                                       changed++;
                                                        break;
                                                }
-                                               response = *q++ = ConfigNak;
+
+                                               LOG(3, s, t, "    Remote requesting MRU of %u.  Rejecting.\n", mru);
+                                               mru = htons(MRU);
+                                               q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, (uint8_t *) &mru, sizeof(mru));
                                        }
-                                       *q++ = type;
-                                       *q++ = 6;
-                                       memset(q, 0, 4); // asyncmap 0
-                                       q += 4;
+                                       break;
+
+                               case 2: // Async-Control-Character-Map
+                                       if (!ntohl(*(uint32_t *)(o + 2))) // all bits zero is OK
+                                               break;
+
+                                       LOG(3, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
                                        break;
 
                                case 3: // Authentication-Protocol
                                        {
-                                               int proto = ntohs(*(u16 *)(o + 2));
+                                               int proto = ntohs(*(uint16_t *)(o + 2));
                                                char proto_name[] = "0x0000";
+                                               int alen;
+
                                                if (proto == PPPPAP)
-                                                       break;
+                                               {
+                                                       if (config->radius_authtypes & AUTHPAP)
+                                                       {
+                                                               sess_local[s].lcp_authtype = AUTHPAP;
+                                                               break;
+                                                       }
 
-                                               if (response && response != ConfigNak) // rej already queued
-                                                       break;
+                                                       strcpy(proto_name, "PAP");
+                                               }
+                                               else if (proto == PPPCHAP)
+                                               {
+                                                       if (config->radius_authtypes & AUTHCHAP
+                                                           && *(o + 4) == 5) // MD5
+                                                       {
+                                                               sess_local[s].lcp_authtype = AUTHCHAP;
+                                                               break;
+                                                       }
 
-                                               if (proto == PPPCHAP)
                                                        strcpy(proto_name, "CHAP");
+                                               }
                                                else
                                                        sprintf(proto_name, "%#4.4x", proto);
 
-                                               LOG(2, session[s].ip, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+                                               LOG(3, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+
+                                               alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
+                                               if (alen < 2) break; // paranoia
 
-                                               if (!response)
+                                               q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+                                               if (q && *response == ConfigNak &&
+                                                       config->radius_authtypes != config->radius_authprefer)
                                                {
-                                                       q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                                                       if (!q)
-                                                       {
-                                                               LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
-                                                               break;
-                                                       }
-                                                       response = *q++ = ConfigNak;
+                                                       // alternate type
+                                                       alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer);
+                                                       if (alen < 2) break;
+                                                       q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
                                                }
-                                               memcpy(q, o, length);
-                                               *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
-                                               q += length;
-                                       }
-                                       break;
 
-                               case 5: // Magic-Number
-                                       magicno = ntohl(*(u32 *)(o + 2));
+                                               break;
+                                       }
                                        break;
 
                                case 4: // Quality-Protocol
+                               case 5: // Magic-Number
                                case 7: // Protocol-Field-Compression
                                case 8: // Address-And-Control-Field-Compression
                                        break;
 
-                               default: // Reject any unknown options
-                                       LOG(2, session[s].ip, s, t, "    Rejecting PPP LCP Option type %d\n", type);
-                                       if (!response || response != ConfigRej) // drop nak in favour of rej
+                               case 17: // Multilink Max-Receive-Reconstructed-Unit
                                        {
-                                               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                                               if (!q)
+                                               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)
                                                {
-                                                       LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
+                                               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);
                                                }
-                                               response = *q++ = ConfigRej;
                                        }
+                                       break;
 
-                                       memcpy(q, o, length);
-                                       q += length;
+                               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);
                        }
                        x -= length;
                        o += length;
                }
 
-               if (!response)
+               if (changed)
+                       cluster_send_session(s);
+
+               if (response)
                {
-                       // Send back a ConfigAck
-                       q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                       if (!q)
-                       {
-                               LOG(3, session[s].ip, s, t, " failed to create packet.\n");
-                               return;
-                       }
-                       response = *q = ConfigAck;
+                       l = q - response; // LCP packet length
+                       *((uint16_t *) (response + 2)) = htons(l); // update header
                }
-
-               LOG(3, session[s].ip, s, t, "Sending %s\n", ppp_lcp_types[response]);
-               tunnelsend(b, l + (q - b), t);
-
-               if (!(session[s].flags & SF_LCP_ACKED))
-                       initlcp(t, s);
-       }
-       else if (*p == ConfigNak)
-       {
-               LOG(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
-               if (config->debug > 3) dumplcp(p, l);
-               return ;
-       }
-       else if (*p == TerminateReq)
-       {
-               *p = TerminateAck;      // close
-               q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
-               if (!q)
+               else
                {
-                       LOG(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
-                       return;
+                       // Send packet back as ConfigAck
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP, 0, 0, 0);
+                       if (!response) return;
+                       *response = ConfigAck;
                }
-               LOG(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n");
-               sessionshutdown(s, "Remote end closed connection.");
-               tunnelsend(b, l + (q - b), t); // send it
-       }
-       else if (*p == TerminateAck)
-       {
-               sessionshutdown(s, "Connection closed.");
-       }
-       else if (*p == EchoReq)
-       {
-               *p = EchoReply;         // reply
-               *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
-               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-               if (!q)
+
+               switch (session[s].ppp.lcp)
                {
-                       LOG(3, session[s].ip, s, t, " failed to send EchoReply.\n");
+               case Closed:
+                       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);
+                       break;
+
+               case Stopped:
+                       initialise_restart_count(s, lcp);
+                       sendlcp(s, t);
+                       if (*response == ConfigAck)
+                               change_state(s, lcp, AckSent);
+                       else
+                               change_state(s, lcp, RequestSent);
+
+                       break;
+
+               case RequestSent:
+                       if (*response == ConfigAck)
+                               change_state(s, lcp, AckSent);
+
+                       break;
+
+               case AckReceived:
+                       if (*response == ConfigAck)
+                               lcp_open(s, t);
+
+                       break;
+
+               case Opened:
+                       lcp_restart(s);
+                       sendlcp(s, t);
+                       /* fallthrough */
+
+               case AckSent:
+                       if (*response == ConfigAck)
+                               change_state(s, lcp, AckSent);
+                       else
+                               change_state(s, lcp, RequestSent);
+
+                       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;
                }
-               LOG(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n");
-               tunnelsend(b, l + (q - b), t); // send it
+
+               LOG(3, s, t, "LCP: send %s\n", ppp_code(*response));
+               if (config->debug > 3) dumplcp(response, l);
+
+               tunnelsend(b, l + (response - b), t);
        }
-       else if (*p == EchoReply)
+       else if (*p == ConfigNak || *p == ConfigRej)
+       {
+               int x = l - 4;
+               uint8_t *o = (p + 4);
+               int authtype = -1;
+
+               while (x > 2)
+               {
+                       int type = o[0];
+                       int length = o[1];
+
+                       if (length == 0 || type == 0 || x < length) break;
+                       switch (type)
+                       {
+                               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);
+                                       }
+                                       else
+                                       {
+                                               sess_local[s].ppp_mru = 0;
+                                               LOG(3, s, t, "    Remote rejected MRU negotiation\n");
+                                       }
+
+                                       break;
+
+                               case 3: // Authentication-Protocol
+                                       if (authtype > 0)
+                                               break;
+
+                                       if (*p == ConfigNak)
+                                       {
+                                               int proto;
+
+                                               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 && length > 4 && *(o + 4) == 5)
+                                               {
+                                                       authtype = config->radius_authtypes & AUTHCHAP;
+                                                       LOG(3, s, t, "    Remote requested CHAP authentication...%sing\n",
+                                                               authtype ? "accept" : "reject");
+                                               }
+                                               else
+                                               {
+                                                       LOG(3, s, t, "    Rejecting unsupported authentication %#4x\n",
+                                                               proto);
+                                               }
+                                       }
+                                       else
+                                       {
+                                               LOG(2, s, t, "LCP: remote rejected auth negotiation\n");
+                                               authtype = 0; // shutdown
+                                       }
+
+                                       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);
+                                       sessionshutdown(s, "Unable to negotiate LCP.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+                                       return;
+                       }
+                       x -= length;
+                       o += length;
+               }
+
+               if (!authtype)
+               {
+                       sessionshutdown(s, "Unsupported authentication.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+                       return;
+               }
+
+               if (authtype > 0)
+                       sess_local[s].lcp_authtype = authtype;
+
+               switch (session[s].ppp.lcp)
+               {
+               case Closed:
+               case Stopped:
+                       {
+                               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);
+
+                               LOG(3, s, t, "LCP: send %s\n", ppp_code(*response));
+                               if (config->debug > 3) dumplcp(response, l);
+
+                               tunnelsend(b, l + (response - b), t);
+                       }
+                       break;
+
+               case RequestSent:
+               case AckSent:
+                       initialise_restart_count(s, lcp);
+                       sendlcp(s, t);
+                       break;
+
+               case AckReceived:
+                       LOG(2, s, t, "LCP: ConfigNak in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
+                       sendlcp(s, t);
+                       break;
+
+               case Opened:
+                       lcp_restart(s);
+                       sendlcp(s, t);
+                       break;
+
+               default:
+                       LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+                       return;
+               }
+       }
+       else if (*p == TerminateReq)
+       {
+               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
+       }
+       else if (*p == ProtocolRej)
+       {
+               uint16_t proto = 0;
+
+               if (l > 4)
+               {
+                       proto = *(p+4);
+                       if (l > 5 && !(proto & 1))
+                       {
+                               proto <<= 8;
+                               proto |= *(p+5);
+                       }
+               }
+
+               if (proto == PPPIPV6CP)
+               {
+                       LOG(3, s, t, "IPv6 rejected\n");
+                       change_state(s, ipv6cp, Closed);
+               }
+               else
+               {
+                       LOG(3, s, t, "LCP protocol reject: 0x%04X\n", proto);
+               }
+       }
+       else if (*p == EchoReq)
+       {
+               *p = EchoReply;         // reply
+               *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP, 0, 0, 0);
+               if (!q) return;
+
+               LOG(4, s, t, "LCP: send %s\n", ppp_code(*q));
+               if (config->debug > 3) dumplcp(q, l);
+
+               tunnelsend(b, l + (q - b), t); // send it
+       }
+       else if (*p == EchoReply)
        {
                // Ignore it, last_packet time is set earlier than this.
        }
-       else if (*p == IdentRequest)
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
+       }
+}
+
+int join_bundle(sessionidt s)
+{
+       // Search for a bundle to join
+       bundleidt i;
+       bundleidt b;
+       for (i = 1; i < MAXBUNDLE; i++)
+       {
+               if (bundle[i].state != BUNDLEFREE)
+               {
+                       if (epdiscmp(session[s].epdis,bundle[i].epdis) && !strcmp(session[s].user, bundle[i].user))
+                       {
+                               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");
+
+       change_state(s, ipcp, Opened);
+
+       if (!(session[s].walled_garden || session[s].flags & SESSION_STARTED))
+       {
+               uint16_t r = radiusnew(s);
+               if (r)
+               {
+                       radiussend(r, RADIUSSTART); // send radius start
+
+                       // don't send further Start records if IPCP is restarted
+                       session[s].flags |= SESSION_STARTED;
+                       cluster_send_session(s);
+               }
+       }
+
+       // start IPv6 if configured and still in passive state
+       if (session[s].ppp.ipv6cp == Stopped)
+       {
+               sendipv6cp(s, t);
+               change_state(s, ipv6cp, RequestSent);
+       }
+}
+
+// Process IPCP messages
+void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
+{
+       uint8_t b[MAXETHER];
+       uint8_t *q = 0;
+       uint16_t hl;
+
+       CSTAT(processipcp);
+
+       LOG_HEX(5, "IPCP", p, l);
+       if (l < 4)
+       {
+               LOG(1, s, t, "Short IPCP %d bytes\n", l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+
+       if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
+       {
+               LOG(1, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+       l = hl;
+
+       if (session[s].ppp.phase < Network)
+       {
+               LOG(2, s, t, "IPCP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase));
+               return;
+       }
+
+       LOG(3, s, t, "IPCP: recv %s\n", ppp_code(*p));
+
+       if (*p == ConfigAck)
+       {
+               switch (session[s].ppp.ipcp)
+               {
+               case RequestSent:
+                       initialise_restart_count(s, ipcp);
+                       change_state(s, ipcp, AckReceived);
+                       break;
+
+               case AckReceived:
+               case Opened:
+                       LOG(2, s, t, "IPCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipcp));
+                       sendipcp(s, t);
+                       change_state(s, ipcp, RequestSent);
+                       break;
+
+               case AckSent:
+                       ipcp_open(s, t);
+                       break;
+
+               default:
+                       LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
+               }
+       }
+       else if (*p == ConfigReq)
+       {
+               uint8_t *response = 0;
+               uint8_t *o = p + 4;
+               int length = l - 4;
+               int gotip = 0;
+               in_addr_t addr;
+
+               while (length > 2)
+               {
+                       if (!o[1] || o[1] > length) return;
+
+                       switch (*o)
+                       {
+                       case 3: // ip address
+                               gotip++; // seen address
+                               if (o[1] != 6) return;
+
+                               addr = htonl(session[s].ip);
+                               if (memcmp(o + 2, &addr, (sizeof addr)))
+                               {
+                                       uint8_t *oq = q;
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+                                       if (!q || (q != oq && *response == ConfigRej))
+                                       {
+                                               sessionshutdown(s, "Can't negotiate IPCP.", CDN_ADMIN_DISC, TERM_USER_ERROR);
+                                               return;
+                                       }
+                               }
+
+                               break;
+
+                       case 129: // primary DNS
+                               if (o[1] != 6) return;
+
+                               addr = htonl(session[s].dns1);
+                               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));
+                                       if (!q) return;
+                               }
+
+                               break;
+
+                       case 131: // secondary DNS
+                               if (o[1] != 6) return;
+
+                               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));
+                                       if (!q) return;
+                               }
+
+                               break;
+
+                       default:
+                               LOG(2, s, t, "    Rejecting PPP IPCP Option type %d\n", *o);
+                               q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
+                               if (!q) return;
+                       }
+
+                       length -= o[1];
+                       o += o[1];
+               }
+
+               if (response)
+               {
+                       l = q - response; // IPCP packet length
+                       *((uint16_t *) (response + 2)) = htons(l); // update header
+               }
+               else if (gotip)
+               {
+                       // Send packet back as ConfigAck
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP, 0, 0, 0);
+                       if (!response) return;
+                       *response = ConfigAck;
+               }
+               else
+               {
+                       LOG(1, s, t, "No IP in IPCP request\n");
+                       STAT(tunnel_rx_errors);
+                       return;
+               }
+
+               switch (session[s].ppp.ipcp)
+               {
+               case Closed:
+                       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);
+                       break;
+
+               case Stopped:
+                       initialise_restart_count(s, ipcp);
+                       sendipcp(s, t);
+                       if (*response == ConfigAck)
+                               change_state(s, ipcp, AckSent);
+                       else
+                               change_state(s, ipcp, RequestSent);
+
+                       break;
+
+               case RequestSent:
+                       if (*response == ConfigAck)
+                               change_state(s, ipcp, AckSent);
+
+                       break;
+
+               case AckReceived:
+                       if (*response == ConfigAck)
+                               ipcp_open(s, t);
+
+                       break;
+
+               case Opened:
+                       initialise_restart_count(s, ipcp);
+                       sendipcp(s, t);
+                       /* fallthrough */
+
+               case AckSent:
+                       if (*response == ConfigAck)
+                               change_state(s, ipcp, AckSent);
+                       else
+                               change_state(s, ipcp, RequestSent);
+
+                       break;
+
+               default:
+                       LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp));
+                       return;
+               }
+
+               LOG(3, s, t, "IPCP: send %s\n", ppp_code(*response));
+               tunnelsend(b, l + (response - b), t);
+       }
+       else if (*p == TerminateReq)
+       {
+               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); // send it
+       }
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
+       }
+}
+
+static void ipv6cp_open(sessionidt s, tunnelidt t)
+{
+       LOG(3, s, t, "IPV6CP: Opened\n");
+
+       change_state(s, ipv6cp, Opened);
+       if (session[s].ipv6prefixlen)
+               route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 1);
+
+       // Send an initial RA (TODO: Should we send these regularly?)
+       send_ipv6_ra(s, t, NULL);
+}
+
+// Process IPV6CP messages
+void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
+{
+       uint8_t b[MAXETHER];
+       uint8_t *q = 0;
+       uint16_t hl;
+
+       CSTAT(processipv6cp);
+
+       LOG_HEX(5, "IPV6CP", p, l);
+       if (l < 4)
+       {
+               LOG(1, s, t, "Short IPV6CP %d bytes\n", l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+
+       if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
+       {
+               LOG(1, s, t, "Length mismatch IPV6CP %u/%u\n", hl, l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+       l = hl;
+
+       if (session[s].ppp.phase < Network)
+       {
+               LOG(2, s, t, "IPV6CP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase));
+               return;
+       }
+
+       LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
+
+       if (!session[s].ip)
+       {
+               LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp));
+               return; // need IPCP to complete...
+       }
+
+       if (*p == ConfigAck)
+       {
+               switch (session[s].ppp.ipv6cp)
+               {
+               case RequestSent:
+                       initialise_restart_count(s, ipv6cp);
+                       change_state(s, ipv6cp, AckReceived);
+                       break;
+
+               case AckReceived:
+               case Opened:
+                       LOG(2, s, t, "IPV6CP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ipv6cp));
+                       sendipv6cp(s, t);
+                       change_state(s, ipv6cp, RequestSent);
+                       break;
+
+               case AckSent:
+                       ipv6cp_open(s, t);
+                       break;
+
+               default:
+                       LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+               }
+       }
+       else if (*p == ConfigReq)
+       {
+               uint8_t *response = 0;
+               uint8_t *o = p + 4;
+               int length = l - 4;
+               int gotip = 0;
+               uint8_t ident[8];
+
+               while (length > 2)
+               {
+                       if (!o[1] || o[1] > length) return;
+
+                       switch (*o)
+                       {
+                       case 1: // interface identifier
+                               gotip++; // seen address
+                               if (o[1] != 10) return;
+
+                               *(uint32_t *) ident = htonl(session[s].ip);
+                               *(uint32_t *) (ident + 4) = 0;
+
+                               if (memcmp(o + 2, ident, sizeof(ident)))
+                               {
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
+                                       if (!q) return;
+                               }
+
+                               break;
+
+                       default:
+                               LOG(2, s, t, "    Rejecting PPP IPV6CP Option type %d\n", *o);
+                               q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
+                               if (!q) return;
+                       }
+
+                       length -= o[1];
+                       o += o[1];
+               }
+
+               if (response)
+               {
+                       l = q - response; // IPV6CP packet length
+                       *((uint16_t *) (response + 2)) = htons(l); // update header
+               }
+               else if (gotip)
+               {
+                       // Send packet back as ConfigAck
+                       response = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP, 0, 0, 0);
+                       if (!response) return;
+                       *response = ConfigAck;
+               }
+               else
+               {
+                       LOG(1, s, t, "No interface identifier in IPV6CP request\n");
+                       STAT(tunnel_rx_errors);
+                       return;
+               }
+
+               switch (session[s].ppp.ipv6cp)
+               {
+               case Closed:
+                       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);
+                       break;
+
+               case Stopped:
+                       initialise_restart_count(s, ipv6cp);
+                       sendipv6cp(s, t);
+                       if (*response == ConfigAck)
+                               change_state(s, ipv6cp, AckSent);
+                       else
+                               change_state(s, ipv6cp, RequestSent);
+
+                       break;
+
+               case RequestSent:
+                       if (*response == ConfigAck)
+                               change_state(s, ipv6cp, AckSent);
+
+                       break;
+
+               case AckReceived:
+                       if (*response == ConfigAck)
+                               ipv6cp_open(s, t);
+
+                       break;
+
+               case Opened:
+                       initialise_restart_count(s, ipv6cp);
+                       sendipv6cp(s, t);
+                       /* fallthrough */
+
+               case AckSent:
+                       if (*response == ConfigAck)
+                               change_state(s, ipv6cp, AckSent);
+                       else
+                               change_state(s, ipv6cp, RequestSent);
+
+                       break;
+
+               default:
+                       LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+                       return;
+               }
+
+               LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*response));
+               tunnelsend(b, l + (response - b), t);
+       }
+       else if (*p == TerminateReq)
        {
-               *p = CodeRej;
-               if (l > MAXCONTROL)
-               {
-                       LOG(1, 0, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
-                       l = 1400;
-               }
-               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-               if (!q)
+               switch (session[s].ppp.ipv6cp)
                {
-                       LOG(3, session[s].ip, s, t, "Failed to create IdentRej.\n");
+               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;
                }
-               LOG_HEX(5, "LCPIdentRej", q, l + 4);
-               tunnelsend(b, 12 + 4 + l, t);
+
+               *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); // send it
+       }
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
+       }
+}
+
+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
        {
-               LOG(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p);
-               STAT(tunnel_rx_errors);
-               return ;
+               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 IPCP messages
-void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
+// process IP packet received
+//
+// This MUST be called with at least 4 byte behind 'p'.
+// (i.e. this routine writes to p[-4]).
+void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       u16 hl;
+       in_addr_t ip;
 
-       CSTAT(call_processipcp);
+       CSTAT(processipin);
 
-       LOG_HEX(5, "IPCP", p, l);
-       if (l < 5)
+       LOG_HEX(5, "IP", p, l);
+
+       if (l < 20)
        {
-               LOG(1, 0, s, t, "Short IPCP %d bytes\n", l);
+               LOG(1, s, t, "IP packet too short %d\n", l);
                STAT(tunnel_rx_errors);
                return ;
        }
 
-       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       ip = ntohl(*(uint32_t *)(p + 12));
+
+       if (l > MAXETHER)
        {
-               LOG(1, 0, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
+               LOG(1, s, t, "IP packet too long %d\n", l);
                STAT(tunnel_rx_errors);
                return ;
        }
-       l = hl;
 
-       if (*p == ConfigAck)
+       if (session[s].ppp.phase != Network || session[s].ppp.ipcp != Opened)
+               return;
+
+       if (!session[s].bundle || bundle[session[s].bundle].num_of_links < 2) // FIXME: 
        {
-               // happy with our IPCP
-               u16 r = session[s].radius;
-               if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
+               // no spoof (do sessionbyip to handled statically routed subnets)
+               if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
                {
-                       if (!r)
-                               r = radiusnew(s);
-                       if (r)
-                               radiussend(r, RADIUSSTART); // send radius start, having got IPCP at last
+                       LOG(4, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0));
+                       return;
                }
-               session[s].flags |= SF_IPCP_ACKED;
+       }
+
+       // run access-list if any
+       if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
+               return;
+
+       // adjust MSS on SYN and SYN,ACK packets with options
+       if ((ntohs(*(uint16_t *) (p + 6)) & 0x1fff) == 0 && p[9] == IPPROTO_TCP) // first tcp fragment
+       {
+               int ihl = (p[0] & 0xf) * 4; // length of IP header
+               if (l >= ihl + 20 && (p[ihl + 13] & TCP_FLAG_SYN) && ((p[ihl + 12] >> 4) > 5))
+                       adjust_tcp_mss(s, t, p, l, p + ihl);
+       }
+
+       // Add on the tun header
+       p -= 4;
+       *(uint32_t *) p = htonl(PKTIP);
+       l += 4;
 
-               LOG(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+       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;
        }
-       if (*p != ConfigReq)
+
+       // send to ethernet
+       if (tun_write(p, l) < 0)
        {
-               LOG(1, 0, s, t, "Unexpected IPCP code %d\n", *p);
-               STAT(tunnel_rx_errors);
-               return ;
+               STAT(tun_tx_errors);
+               LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+                       l, strerror(errno), tunfd, p);
+
+               return;
        }
-       LOG(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
 
-       if (!session[s].ip)
+       p += 4;
+       l -= 4;
+
+       if (session[s].snoop_ip && session[s].snoop_port)
        {
-               LOG(3, 0, s, t, "Waiting on radius reply\n");
-               return;                 // have to wait on RADIUS reply
+               // Snooping this session
+               snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
-       // form a config reply quoting the IP in the session
+
+       update_sessions_in_stat(s, l);
+
+       eth_tx += l;
+
+       STAT(tun_tx_packets);
+       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 frag_offset, M_offset;
+       uint16_t frag_index, M_index;
+       fragmentationt *this_fragmentation = &frag[b];
+       uint8_t begin_frame = (*p & MP_BEGIN);
+        uint8_t end_frame = (*p & MP_END);
+        uint32_t seq_num;
+       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);
+        }
+
+       // calculate this fragment's offset from the begin seq in the bundle
+       frag_offset = (seq_num + this_bundle->max_seq - this_fragmentation->start_seq) & (this_bundle->max_seq-1);
+
+       // discard this fragment if frag_offset is bigger that the fragmentation buffer size
+       if (frag_offset >= MAXFRAGNUM)
+        {
+               LOG(3, s, t, "MPPP: Index out of range, received more than MAXFRAGNUM fragment (lost frag) seq:%d, begin_seq:%d, bundle:%d, max:%d\n",seq_num, this_fragmentation->start_seq, b, this_bundle->max_seq);
+                return;
+        }
+       
+       // update M
+       sess_local[s].last_seq = seq_num;
+       if (seq_num < this_fragmentation->M)
+               this_fragmentation->M = seq_num;
+       else
        {
-               u8 b[MAXCONTROL];
-               u8 *i,
-               *q;
+               uint32_t i, min = 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 < min)
+                               min = s_seq;
+               }
+               this_fragmentation->M = min;
+       }
+
+       LOG(4, s, t, "MPPP: Setting M to %d\n", this_fragmentation->M); 
+       //calculate M's offset from the begin seq in the bundle
+       M_offset = (this_fragmentation->M + this_bundle->max_seq - this_fragmentation->start_seq) & (this_bundle->max_seq-1);
 
-               q = p + 4;
-               i = p + l;
-               while (q < i && q[1])
+       //caculate M's index in the fragment array
+       M_index = (M_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+       
+       //caculate received fragment's index in the fragment array
+       frag_index = (frag_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+
+       //frame with a single fragment
+       if (begin_frame && end_frame)
+       {
+               // process and reset fragmentation
+                LOG(4, s, t, "MPPP: Both bits are set (Begin and End).\n");
+               this_fragmentation->fragment[frag_index].length = l;
+               this_fragmentation->fragment[frag_index].sid = s;
+               this_fragmentation->fragment[frag_index].flags = flags;
+               this_fragmentation->fragment[frag_index].seq = seq_num;
+               this_fragmentation->re_frame_begin_index = frag_index;
+               this_fragmentation->re_frame_end_index = frag_index;
+               processmpframe(s, t, p, l, 0);
+               this_fragmentation->fragment[frag_index].length = 0;
+               this_fragmentation->fragment[frag_index].flags = 0;
+               end_index = frag_index;
+       }
+       else
+       {
+               // insert the frame in it's place
+               fragmentt *this_frag = &this_fragmentation->fragment[frag_index];
+               this_frag->length = l;
+               this_frag->sid = s;
+               this_frag->flags = flags;
+               this_frag->seq = seq_num;
+                memcpy(this_frag->data, p, l);
+
+               // try to assemble the frame that has the received fragment as a member         
+               // get the beginning of this frame
+               begin_index = end_index = frag_index;
+               while (this_fragmentation->fragment[begin_index].length)
                {
-                       if (*q != 0x81 && *q != 0x83 && *q != 3)
+                       if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
                                break;
-                       q += q[1];
+                       begin_index = (begin_index ? (begin_index -1) : (MAXFRAGNUM -1)); 
                }
-               if (q < i)
+
+               // return if a lost fragment is found
+               if (!(this_fragmentation->fragment[begin_index].length))
+                       return; // assembling frame failed
+               // get the end of his frame
+               while (this_fragmentation->fragment[end_index].length)
                {
-                       // reject
-                       u16 n = 4;
-                       i = p + l;
-                       if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
-                       {
-                               LOG(2, 0, s, t, "Failed to send IPCP ConfigRej\n");
-                               return;
-                       }
-                       *q = ConfigRej;
-                       p += 4;
-                       while (p < i && p[1])
-                       {
-                               if (*p != 0x81 && *p != 0x83 && *p != 3)
-                               {
-                                       LOG(2, 0, s, t, "IPCP reject %d\n", *p);
-                                       memcpy(q + n, p, p[1]);
-                                       n += p[1];
-                               }
-                               p += p[1];
-                       }
-                       *(u16 *) (q + 2) = htons(n);
-                       LOG(4, session[s].ip, s, t, "Sending ConfigRej\n");
-                       tunnelsend(b, n + (q - b), t); // send it
+                       if (this_fragmentation->fragment[end_index].flags & MP_END)
+                               break;
+                       end_index = (end_index +1) & MAXFRAGNUM_MASK; 
                }
-               else
-               {
-                       LOG(4, session[s].ip, s, t, "Sending ConfigAck\n");
-                       *p = ConfigAck;
-                       if ((i = findppp(p, 0x81))) // Primary DNS address
-                       {
-                               if (*(u32 *) (i + 2) != htonl(session[s].dns1))
-                               {
-                                       *(u32 *) (i + 2) = htonl(session[s].dns1);
-                                       *p = ConfigNak;
-                                       LOG(5, session[s].ip, s, t, "   DNS1 = %s\n", inet_toa(session[s].dns1));
-                               }
-                       }
-                       if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it)
-                       {
-                               if (*(u32 *) (i + 2) != htonl(session[s].dns2))
-                               {
-                                       *(u32 *) (i + 2) = htonl(session[s].dns2);
-                                       *p = ConfigNak;
-                                       LOG(5, session[s].ip, s, t, "   DNS2 = %s\n", inet_toa(session[s].dns2));
-                               }
-                       }
-                       i = findppp(p, 3);              // IP address
-                       if (!i || i[1] != 6)
-                       {
-                               LOG(1, 0, s, t, "No IP in IPCP request\n");
-                               STAT(tunnel_rx_errors);
-                               return ;
-                       }
-                       if (*(u32 *) (i + 2) != htonl(session[s].ip))
-                       {
-                               *(u32 *) (i + 2) = htonl(session[s].ip);
-                               *p = ConfigNak;
-                               LOG(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
-                                               inet_toa(htonl(session[s].ip)));
-                       }
-                       if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+
+               // 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
+               uint32_t i;
+
+                       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)
                        {
-                               LOG(2, 0, s, t, " Failed to send IPCP packet.\n");
-                               return;
+                               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;
                        }
-                       tunnelsend(b, l + (q - b), t); // send it
+                }
+                // 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;
                }
        }
+       //discard fragments received before the recently assembled frame
+       begin_index = this_fragmentation->start_index;
+       this_fragmentation->start_index = (end_index + 1) & MAXFRAGNUM_MASK;
+        this_fragmentation->start_seq = (this_fragmentation->fragment[end_index].seq + 1) & (this_bundle->max_seq-1);
+       //clear length and flags of the discarded fragments
+       while (begin_index != this_fragmentation->start_index)
+        {
+                this_fragmentation->fragment[begin_index].flags = 0;
+               this_fragmentation->fragment[begin_index].length = 0;
+                begin_index = (begin_index + 1) & MAXFRAGNUM_MASK;
+        }
+
+       LOG(4, s, t, "MPPP after assembling: M index is =%d, start index is = %d, start seq=%d\n",M_index, this_fragmentation->start_index, this_fragmentation->start_seq);     
+       return;
 }
 
-// process IP packet received
+// process IPv6 packet received
 //
 // This MUST be called with at least 4 byte behind 'p'.
 // (i.e. this routine writes to p[-4]).
-void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
+void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-       ipt ip;
+       struct in6_addr ip;
+       in_addr_t ipv4;
 
-       CSTAT(call_processipin);
+       CSTAT(processipv6in);
 
-       LOG_HEX(5, "IP", p, l);
+       LOG_HEX(5, "IPv6", p, l);
 
-       ip = ntohl(*(u32 *)(p + 12));
+       ip = *(struct in6_addr *) (p + 8);
+       ipv4 = ntohl(*(uint32_t *)(p + 16));
 
        if (l > MAXETHER)
        {
-               LOG(1, ip, s, t, "IP packet too long %d\n", l);
+               LOG(1, s, t, "IP packet too long %d\n", l);
                STAT(tunnel_rx_errors);
                return ;
        }
 
-       // no spoof (do sessionbyip to handled statically routed subnets)
-       if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
+       if (session[s].ppp.phase != Network || session[s].ppp.ipv6cp != Opened)
+               return;
+
+       // no spoof
+       if (ipv4 != session[s].ip && memcmp(&config->ipv6_prefix, &ip, 8) && sessionbyipv6(ip) != s)
        {
-               LOG(5, ip, s, t, "Dropping packet with spoofed IP %s\n", inet_toa(htonl(ip)));
+               char str[INET6_ADDRSTRLEN];
+               LOG(5, s, t, "Dropping packet with spoofed IP %s\n",
+                               inet_ntop(AF_INET6, &ip, str, INET6_ADDRSTRLEN));
+               return;
+       }
+
+       // Check if it's a Router Solicition message.
+       if (*(p + 6) == 58 && *(p + 7) == 255 && *(p + 24) == 0xFF && *(p + 25) == 2 &&
+                       *(uint32_t *)(p + 26) == 0 && *(uint32_t *)(p + 30) == 0 &&
+                       *(uint32_t *)(p + 34) == 0 &&
+                       *(p + 38) == 0 && *(p + 39) == 2 && *(p + 40) == 133) {
+               LOG(3, s, t, "Got IPv6 RS\n");
+               send_ipv6_ra(s, t, &ip);
                return;
        }
 
        // Add on the tun header
        p -= 4;
-       *(u32 *)p = htonl(0x00000800);
+       *(uint32_t *) p = htonl(PKTIPV6);
        l += 4;
 
-       if (session[s].tbf_in && !config->cluster_iam_master) { // Are we throttled and a slave?
-               master_throttle_packet(session[s].tbf_in, p, l); // Pass it to the master for handling.
+       // 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;
        }
 
-       if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets.
+       // 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);
                return;
        }
@@ -728,242 +2065,457 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
        if (tun_write(p, l) < 0)
        {
                STAT(tun_tx_errors);
-               LOG(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+               LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
                        l, strerror(errno), tunfd, p);
 
                return;
        }
 
+       p += 4;
+       l -= 4;
+
        if (session[s].snoop_ip && session[s].snoop_port)
        {
                // Snooping this session
-               snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
+               snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
 
-       session[s].cin += l - 4;
-       session[s].total_cin += l - 4;
-       sess_count[s].cin += l - 4;
+       update_sessions_in_stat(s, l);
 
-       session[s].pin++;
-       eth_tx += l - 4;
+       eth_tx += l;
 
        STAT(tun_tx_packets);
-       INC_STAT(tun_tx_bytes, l - 4);
+       INC_STAT(tun_tx_bytes, l);
 }
 
 //
 // Helper routine for the TBF filters.
 // Used to send queued data in from the user.
 //
-void send_ipin(sessionidt s, u8 *buf, int len)
+void send_ipin(sessionidt s, uint8_t *buf, int len)
 {
        LOG_HEX(5, "IP in throttled", buf, len);
 
        if (write(tunfd, buf, len) < 0)
        {
                STAT(tun_tx_errors);
-               LOG(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+               LOG(0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
                        len, strerror(errno), tunfd, buf);
 
                return;
        }
 
+       buf += 4;
+       len -= 4;
+
        if (session[s].snoop_ip && session[s].snoop_port)
        {
                // Snooping this session
-               snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
+               snoop_send_packet(buf, len, session[s].snoop_ip, session[s].snoop_port);
        }
 
        // Increment packet counters
-       session[s].cin += len - 4;
-       session[s].total_cin += len - 4;
-       sess_count[s].cin += len - 4;
-
+       increment_counter(&session[s].cin, &session[s].cin_wrap, len);
+       session[s].cin_delta += len;
        session[s].pin++;
-       eth_tx += len - 4;
+
+       sess_local[s].cin += len;
+       sess_local[s].pin++;
+
+       eth_tx += len;
 
        STAT(tun_tx_packets);
-       INC_STAT(tun_tx_bytes, l - 4);
+       INC_STAT(tun_tx_bytes, len - 4);
 }
 
 
 // Process CCP messages
-void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
+void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
+       uint8_t b[MAXETHER];
+       uint8_t *q;
 
-       CSTAT(call_processccp);
+       CSTAT(processccp);
 
        LOG_HEX(5, "CCP", p, l);
-       if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
+
+       if (session[s].ppp.phase < Network)
+       {
+               LOG(2, s, t, "CCP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase));
+               return;
+       }
+
+       if (l < 1)
        {
-               LOG(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
+               LOG(1, s, t, "Short CCP packet\n");
                STAT(tunnel_rx_errors);
-               return ;
        }
-       // reject
+
+       LOG(4, s, t, "CCP: recv %s\n", ppp_code(*p));
+       if (*p == ConfigAck)
        {
-               u8 b[MAXCONTROL];
-               u8 *q;
-               if (*p == ConfigReq)
+               switch (session[s].ppp.ccp)
                {
-                       if (l < 6)
-                       {
-                               *p = ConfigAck;         // accept no compression
-                       }
-                       else
-                       {
-                               *p = ConfigRej;         // reject
-                               sendccp(t, s);
-                       }
+               case RequestSent:
+                       initialise_restart_count(s, ccp);
+                       change_state(s, ccp, AckReceived);
+                       break;
+
+               case AckReceived:
+               case Opened:
+                       LOG(2, s, t, "CCP: ConfigAck in state %s?  Sending ConfigReq\n", ppp_state(session[s].ppp.ccp));
+                       sendccp(s, t);
+                       change_state(s, ccp, RequestSent);
+                       break;
+
+               case AckSent:
+                       LOG(3, s, t, "CCP: Opened\n");
+                       change_state(s, ccp, Opened);
+                       break;
+
+               default:
+                       LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
                }
-               else
-                       *p = TerminateAck;              // close
-               if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
+       }
+       else if (*p == ConfigReq)
+       {
+               if (l < 6) // accept no compression
+                       *p = ConfigAck;
+               else // compression requested--reject
+                       *p = ConfigRej;
+
+               q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP, 0, 0, 0);
+               if (!q) return;
+
+               switch (session[s].ppp.ccp)
                {
-                       LOG(1,0,0,0, "Failed to send CCP packet.\n");   
+               case Closed:
+                       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);
+                       break;
+
+               case Stopped:
+                       initialise_restart_count(s, ccp);
+                       sendccp(s, t);
+                       if (*q == ConfigAck)
+                               change_state(s, ccp, AckSent);
+                       else
+                               change_state(s, ccp, RequestSent);
+
+                       break;
+
+               case RequestSent:
+                       if (*q == ConfigAck)
+                               change_state(s, ccp, AckSent);
+
+                       break;
+
+               case AckReceived:
+                       if (*q == ConfigAck)
+                               change_state(s, ccp, Opened);
+
+                       break;
+
+               case Opened:
+                       initialise_restart_count(s, ccp);
+                       sendccp(s, t);
+                       /* fallthrough */
+
+               case AckSent:
+                       if (*q == ConfigAck)
+                               change_state(s, ccp, AckSent);
+                       else
+                               change_state(s, ccp, RequestSent);
+
+                       break;
+
+               default:
+                       LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
                        return;
                }
-               tunnelsend(b, l + (q - b), t); // send it
+
+               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, 0, 0, 0);
+               if (!q) return;
+               LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
+               tunnelsend(b, l + (q - b), t);
+               change_state(s, ccp, Stopped);
+       }
+       else if (*p != CodeRej)
+       {
+               ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b));
        }
 }
 
-// send a CHAP PP packet
-void sendchap(tunnelidt t, sessionidt s)
+// send a CHAP challenge
+void sendchap(sessionidt s, tunnelidt t)
 {
-       u8 b[MAXCONTROL];
-       u16 r = session[s].radius;
-       u8 *q;
+       uint8_t b[MAXETHER];
+       uint16_t r;
+       uint8_t *q;
 
-       CSTAT(call_sendchap);
+       CSTAT(sendchap);
 
+       r = radiusnew(s);
        if (!r)
        {
-               LOG(1, 0, s, t, "No RADIUS to send challenge\n");
+               LOG(1, s, t, "No RADIUS to send challenge\n");
                STAT(tunnel_tx_errors);
-               return ;
-       }
-       LOG(1, 0, s, t, "Send CHAP challenge\n");
-       {
-               // new challenge
-               int n;
-               for (n = 0; n < 15; n++)
-                       radius[r].auth[n] = rand();
+               return;
        }
+
+       LOG(1, s, t, "Send CHAP challenge\n");
+
        radius[r].chap = 1;             // CHAP not PAP
        radius[r].id++;
        if (radius[r].state != RADIUSCHAP)
                radius[r].try = 0;
+
        radius[r].state = RADIUSCHAP;
        radius[r].retry = backoff(radius[r].try++);
        if (radius[r].try > 5)
        {
-               sessionshutdown(s, "Timeout CHAP");
+               sessionshutdown(s, "CHAP timeout.", CDN_ADMIN_DISC, TERM_REAUTHENTICATION_FAILURE);
                STAT(tunnel_tx_errors);
                return ;
        }
-       q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
-       if (!q)
-       {
-               LOG(1, 0, s, t, "failed to send CHAP challenge.\n");
-               return;
-       }
+       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;                              // length
+       q[4] = 16;                              // value size (size of challenge)
        memcpy(q + 5, radius[r].auth, 16);      // challenge
-       strcpy(q + 21, hostname);               // our name
-       *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length
+       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
 }
 
 // fill in a L2TP message with a PPP frame,
-// copies existing PPP message and changes magic number if seen
 // returns start of PPP frame
-u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 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)
-               return NULL;    // 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;
+       }
 
-       *(u16 *) (b + 0) = htons(0x0002); // L2TP with no options
-       *(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
-       *(u16 *) (b + 4) = htons(session[s].far); // session
+       if (prio) hdr |= 0x0100; // set priority bit
+
+       *(uint16_t *) (b + 0) = htons(hdr);
+       *(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel
+       *(uint16_t *) (b + 4) = htons(session[s].far); // session
        b += 6;
-       if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC))
+
+       // Check whether this session is part of multilink
+       if (bid)
+       {
+               if (bundle[bid].num_of_links > 1)
+                       type = PPPMP; // Change PPP message type to the PPPMP
+               else
+                       bid = 0;
+       }
+
+       if (type == PPPLCP || !(session[s].flags & SESSION_ACFC))
        {
-               *(u16 *) b = htons(0xFF03); // HDLC header
+               *(uint16_t *) b = htons(0xFF03); // HDLC header
                b += 2;
        }
-       if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
-               *b++ = mtype;
+
+       if (type < 0x100 && session[s].flags & SESSION_PFC)
+       {
+               *b++ = type;
+       }
        else
        {
-               *(u16 *) b = htons(mtype);
+               *(uint16_t *) b = htons(type);
                b += 2;
        }
 
-       if (l + 12 > size) {
-               LOG(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l);
-               return NULL;    // Run out of room to hold the packet!
+       if (bid)
+       {
+               // Set the sequence number and (B)egin (E)nd flags
+               if (session[s].mssf)
+               {
+                       // Set the multilink bits
+                       uint16_t bits_send = mp_bits;
+                       *(uint16_t *) b = htons((bundle[bid].seq_num_t & 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=%d)\n", size, (b - start) + l);
+               return NULL;
        }
+
+       // Copy the payload
        if (p && l)
                memcpy(b, p, l);
+
        return b;
 }
 
-// find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 *b, u8 mtype)
+static int add_lcp_auth(uint8_t *b, int size, int authtype)
 {
-       u16 l = ntohs(*(u16 *) (b + 2));
-       if (l < 4)
+       int len = 0;
+       if ((authtype == AUTHCHAP && size < 5) || size < 4)
                return 0;
-       b += 4;
-       l -= 4;
-       while (l)
+
+       *b++ = 3; // Authentication-Protocol
+       if (authtype == AUTHCHAP)
+       {
+               len = *b++ = 5; // length
+               *(uint16_t *) b = htons(PPPCHAP); b += 2;
+               *b++ = 5; // MD5
+       }
+       else if (authtype == AUTHPAP)
+       {
+               len = *b++ = 4; // length
+               *(uint16_t *) b = htons(PPPPAP); b += 2;
+       }
+       else
        {
-               if (l < b[1] || !b[1])
-                       return 0;               // faulty
-               if (*b == mtype)
-                       return b;
-               l -= b[1];
-               b += b[1];
+               LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype);
        }
-       return 0;
+
+       return len;
 }
 
-// Send initial LCP ConfigReq
-void initlcp(tunnelidt t, sessionidt s)
+// Send LCP ConfigReq for MRU, authentication type and magic no
+void sendlcp(sessionidt s, tunnelidt t)
 {
-       char b[500] = {0}, *q;
+       uint8_t b[500], *q, *l;
+       int authtype = sess_local[s].lcp_authtype;
 
-       q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
-       if (!q)
-       {
-               LOG(1, 0, s, t, "Failed to send LCP ConfigReq.\n");
+        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 including MP options\n",
+           authtype ? " (" : "",
+           authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
+           authtype ? ")" : "");
+
+       l = q;
+       *l++ = ConfigReq;
+       *l++ = ++sess_local[s].lcp_ident; // ID
+
+       l += 2; //Save space for length
+
+       if (sess_local[s].ppp_mru)
+       {
+               *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
+               *(uint16_t *) l = htons(sess_local[s].ppp_mru); l += 2;
        }
-       LOG(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
-       *q = ConfigReq;
-       *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
-       *(u16 *)(q + 2) = htons(14); // Length
-       *(u8 *)(q + 4) = 5;
-       *(u8 *)(q + 5) = 6;
-       *(u32 *)(q + 6) = htonl(session[s].magic);
-       *(u8 *)(q + 10) = 3;
-       *(u8 *)(q + 11) = 4;
-       *(u16 *)(q + 12) = htons(PPPPAP); // PAP
-       tunnelsend(b, 12 + 14, t);
+
+       if (authtype)
+               l += add_lcp_auth(l, sizeof(b) - (l - b), authtype);
+
+       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
+
+       LOG_HEX(5, "PPPLCP", q, l - q);
+       if (config->debug > 3) dumplcp(q, l - q);
+
+       tunnelsend(b, (l - b), t);
+       restart_timer(s, lcp);
 }
 
-// Send CCP reply
-void sendccp(tunnelidt t, sessionidt s)
+// Send CCP request for no compression
+void sendccp(sessionidt s, tunnelidt t)
 {
-       char *q, b[500] = {0};
+       uint8_t b[500], *q;
+
+       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");
 
-       q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
        *q = ConfigReq;
-       *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
-       *(u16 *)(q + 2) = htons(4); // Length
+       *(q + 1) = ++sess_local[s].lcp_ident; // ID
+       *(uint16_t *)(q + 2) = htons(4); // Length
+
        LOG_HEX(5, "PPPCCP", q, 4);
        tunnelsend(b, (q - b) + 4 , t);
+       restart_timer(s, ccp);
 }
 
+// Reject unknown/unconfigured protocols
+void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto)
+{
+
+       uint8_t buf[MAXETHER];
+       uint8_t *q;
+       int mru = session[s].mru;
+       if (mru < MINMTU) mru = MINMTU;
+       if (mru > sizeof(buf)) mru = sizeof(buf);
+
+       l += 6;
+       if (l > mru) l = mru;
+
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP, 0, 0, 0);
+       if (!q) return;
+
+       *q = ProtocolRej;
+       *(q + 1) = ++sess_local[s].lcp_ident;
+       *(uint16_t *)(q + 2) = htons(l);
+       *(uint16_t *)(q + 4) = htons(proto);
+       memcpy(q + 6, p, l - 6);
+
+       if (proto == PPPIPV6CP)
+               LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+       else
+               LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+       tunnelsend(buf, l + (q - buf), t);
+}