add Multilink support from Khaled Al Hamwi
[l2tpns.git] / l2tpns.c
index 67211ce..bd044eb 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.146 2005/11/04 14:41:50 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.163 2006/04/27 09:53:49 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -96,9 +96,9 @@ uint32_t eth_tx = 0;
 static uint32_t ip_pool_size = 1;      // Size of the pool of addresses used for dynamic address allocation.
 time_t time_now = 0;                   // Current time in seconds since epoch.
 static char time_now_string[64] = {0}; // Current time as a string.
-int time_changed = 0;                  // time_now changed
+static int time_changed = 0;           // time_now changed
 char main_quit = 0;                    // True if we're in the process of exiting.
-char main_reload = 0;                  // Re-load pending
+static char main_reload = 0;           // Re-load pending
 linked_list *loaded_plugins;
 linked_list *plugins[MAX_PLUGIN_TYPES];
 
@@ -127,6 +127,7 @@ config_descriptt config_values[] = {
        CONFIG("radius_authtypes", radius_authtypes_s, STRING),
        CONFIG("radius_dae_port", radius_dae_port, SHORT),
        CONFIG("allow_duplicate_users", allow_duplicate_users, BOOL),
+       CONFIG("guest_account", guest_user, STRING),
        CONFIG("bind_address", bind_address, IPv4),
        CONFIG("peer_address", peer_address, IPv4),
        CONFIG("send_garp", send_garp, BOOL),
@@ -174,6 +175,8 @@ static sessiont shut_acct[8192];
 static sessionidt shut_acct_n = 0;
 
 tunnelt *tunnel = NULL;                        // Array of tunnel structures.
+bundlet *bundle = NULL;                        // Array of bundle structures.
+fragmentationt *frag = NULL;           // Array of fragmentation structures.
 sessiont *session = NULL;              // Array of session structures.
 sessionlocalt *sess_local = NULL;      // Array of local per-session counters.
 radiust *radius = NULL;                        // Array of radius structures.
@@ -200,9 +203,10 @@ static void initplugins(void);
 static int add_plugin(char *plugin_name);
 static int remove_plugin(char *plugin_name);
 static void plugins_done(void);
-static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local);
 static tunnelidt new_tunnel(void);
 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
+static void bundleclear(bundleidt b);
 
 // on slaves, alow BGP to withdraw cleanly before exiting
 #define QUIT_DELAY     5
@@ -554,6 +558,13 @@ static void inittun(void)
                LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
                exit(1);
        }
+       /* set MTU to modem MRU */
+       ifr.ifr_mtu = MRU;
+       if (ioctl(ifrfd, SIOCSIFMTU, (void *) &ifr) < 0)
+       {
+               LOG(0, 0, 0, "Error setting tun MTU: %s\n", strerror(errno));
+               exit(1);
+       }
        ifr.ifr_flags = IFF_UP;
        if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
        {
@@ -627,6 +638,7 @@ static void initudp(void)
        addr.sin_port = htons(NSCTL_PORT);
        controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+       setsockopt(controlfd, SOL_IP, IP_PKTINFO, &on, sizeof(on)); // recvfromto
        if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
        {
                LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
@@ -639,6 +651,7 @@ static void initudp(void)
        addr.sin_port = htons(config->radius_dae_port);
        daefd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        setsockopt(daefd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+       setsockopt(daefd, SOL_IP, IP_PKTINFO, &on, sizeof(on)); // recvfromto
        if (bind(daefd, (void *) &addr, sizeof(addr)) < 0)
        {
                LOG(0, 0, 0, "Error in DAE bind: %s\n", strerror(errno));
@@ -933,18 +946,14 @@ void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
 
        if (!t)
        {
-               static int backtrace_count = 0;
                LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
                STAT(tunnel_tx_errors);
-               log_backtrace(backtrace_count, 5)
                return;
        }
 
        if (!tunnel[t].ip)
        {
-               static int backtrace_count = 0;
                LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
-               log_backtrace(backtrace_count, 5)
                STAT(tunnel_tx_errors);
                return;
        }
@@ -1043,7 +1052,55 @@ void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *t
        sum = orig + (~MSS & 0xffff);
        sum += ntohs(*(uint16_t *) (tcp + 16));
        sum = (sum & 0xffff) + (sum >> 16);
-       *(uint16_t *) (tcp + 16) = htons(sum);
+       *(uint16_t *) (tcp + 16) = htons(sum + (sum >> 16));
+}
+
+void processmpframe(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint8_t extra)
+{
+       uint16_t proto;
+       if (extra) {
+               // Skip the four extra bytes
+               p += 4;
+               l -= 4;
+       }
+
+       // Process this frame
+       if (*p & 1)
+       {
+               proto = *p++;
+               l--;
+       }
+       else
+       {
+               proto = ntohs(*(uint16_t *) p);
+               p += 2;
+               l -= 2;
+       }
+       if (proto == PPPIP)
+       {
+               if (session[s].die)
+               {
+                       LOG(4, s, t, "MPPP: Session %d is closing.  Don't process PPP packets\n", s);
+                       return;              // closing session, PPP not processed
+               }
+               session[s].last_packet = time_now;
+               processipin(s, t, p, l);
+       }
+       else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
+       {
+               if (session[s].die)
+               {
+                       LOG(4, s, t, "MPPP: Session %d is closing.  Don't process PPP packets\n", s);
+                       return;              // closing session, PPP not processed
+               }
+
+               session[s].last_packet = time_now;
+               processipv6in(s, t, p, l);
+       }
+       else
+       {
+               LOG(2, s, t, "MPPP: Unsupported MP protocol 0x%04X received\n",proto);
+       }
 }
 
 // process outgoing (to tunnel) IP
@@ -1058,7 +1115,8 @@ static void processipout(uint8_t *buf, int len)
        uint8_t *data = buf;    // Keep a copy of the originals.
        int size = len;
 
-       uint8_t b[MAXETHER + 20];
+       uint8_t b1[MAXETHER + 20];
+       uint8_t b2[MAXETHER + 20];
 
        CSTAT(processipout);
 
@@ -1170,20 +1228,51 @@ static void processipout(uint8_t *buf, int len)
                        master_throttle_packet(sp->tbf_out, data, size);
                return;
        }
-       else if (sp->walled_garden && !config->cluster_iam_master)
+
+       if (sp->walled_garden && !config->cluster_iam_master)
        {
                // We are walled-gardening this
                master_garden_packet(s, data, size);
                return;
        }
 
-       LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
-
        // Add on L2TP header
        {
-               uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
-               if (!p) return;
-               tunnelsend(b, len + (p-b), t); // send it...
+               bundleidt bid = 0;
+               if (session[s].bundle && bundle[session[s].bundle].num_of_links > 1)
+               {
+                       bid = session[s].bundle;
+                       s = bundle[bid].members[bundle[bid].current_ses = ++bundle[bid].current_ses % bundle[bid].num_of_links];
+                       LOG(4, s, t, "MPPP: (1)Session number becomes: %d\n", s);
+                       if (len > 256)
+                       {
+                               // Partition the packet to 2 fragments
+                               uint32_t frag1len = len / 2;
+                               uint32_t frag2len = len - frag1len;
+                               uint8_t *p = makeppp(b1, sizeof(b1), buf, frag1len, s, t, PPPIP, 0, bid, MP_BEGIN);
+                               uint8_t *q;
+
+                               if (!p) return;
+                               tunnelsend(b1, frag1len + (p-b1), t); // send it...
+                               s = bundle[bid].members[bundle[bid].current_ses = ++bundle[bid].current_ses % bundle[bid].num_of_links];
+                               LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
+                               q = makeppp(b2, sizeof(b2), buf+frag1len, frag2len, s, t, PPPIP, 0, bid, MP_END);
+                               if (!q) return;
+                               tunnelsend(b2, frag2len + (q-b2), t); // send it...
+                       }
+                       else {
+                               // Send it as one frame
+                               uint8_t *p = makeppp(b1, sizeof(b1), buf, len, s, t, PPPIP, 0, bid, MP_BOTH_BITS);
+                               if (!p) return;
+                               tunnelsend(b1, len + (p-b1), t); // send it...
+                       }
+               }
+               else
+               {
+                       uint8_t *p = makeppp(b1, sizeof(b1), buf, len, s, t, PPPIP, 0, 0, 0);
+                       if (!p) return;
+                       tunnelsend(b1, len + (p-b1), t); // send it...
+               }
        }
 
        // Snooping this session, send it to intercept box
@@ -1267,6 +1356,12 @@ static void processipv6out(uint8_t * buf, int len)
                }
                return;
        }
+       if (session[s].bundle && bundle[session[s].bundle].num_of_links > 1)
+       {
+               bundleidt bid = session[s].bundle;
+               s = bundle[bid].members[bundle[bid].current_ses = ++bundle[bid].current_ses % bundle[bid].num_of_links];
+               LOG(3, s, session[s].tunnel, "MPPP: Session number becomes: %d\n", s);
+       }
        t = session[s].tunnel;
        sp = &session[s];
 
@@ -1292,7 +1387,7 @@ static void processipv6out(uint8_t * buf, int len)
 
        // Add on L2TP header
        {
-               uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6);
+               uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6, 0, 0, 0);
                if (!p) return;
                tunnelsend(b, len + (p-b), t); // send it...
        }
@@ -1344,7 +1439,7 @@ static void send_ipout(sessionidt s, uint8_t *buf, int len)
 
        // Add on L2TP header
        {
-               uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
+               uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP, 0, 0, 0);
                if (!p) return;
                tunnelsend(b, len + (p-b), t); // send it...
        }
@@ -1553,7 +1648,7 @@ void filter_session(sessionidt s, int filter_in, int filter_out)
 }
 
 // start tidy shutdown of session
-void sessionshutdown(sessionidt s, char *reason, int result, int error)
+void sessionshutdown(sessionidt s, char const *reason, int cdn_result, int cdn_error, int term_cause)
 {
        int walled_garden = session[s].walled_garden;
 
@@ -1581,7 +1676,11 @@ void sessionshutdown(sessionidt s, char *reason, int result, int error)
                {
                        // stop, if not already trying
                        if (radius[r].state != RADIUSSTOP)
+                       {
+                               radius[r].term_cause = term_cause;
+                               radius[r].term_msg = reason;
                                radiussend(r, RADIUSSTOP);
+                       }
                }
                else
                        LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
@@ -1621,18 +1720,18 @@ void sessionshutdown(sessionidt s, char *reason, int result, int error)
        if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
                throttle_session(s, 0, 0);
 
-       if (result)
+       if (cdn_result)
        {                            // Send CDN
                controlt *c = controlnew(14); // sending CDN
-               if (error)
+               if (cdn_error)
                {
                        uint8_t buf[4];
-                       *(uint16_t *) buf     = htons(result);
-                       *(uint16_t *) (buf+2) = htons(error);
+                       *(uint16_t *) buf     = htons(cdn_result);
+                       *(uint16_t *) (buf+2) = htons(cdn_error);
                        controlb(c, 1, buf, 4, 1);
                }
                else
-                       control16(c, 1, result, 1);
+                       control16(c, 1, cdn_result, 1);
 
                control16(c, 14, s, 1);   // assigned session (our end)
                controladd(c, session[s].far, session[s].tunnel); // send the message
@@ -1669,7 +1768,7 @@ void sendipcp(sessionidt s, tunnelidt t)
                session[s].unique_id = last_id;
        }
 
-       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP, 0, 0, 0);
        if (!q) return;
 
        *q = ConfigReq;
@@ -1693,7 +1792,7 @@ void sendipv6cp(sessionidt s, tunnelidt t)
        CSTAT(sendipv6cp);
        LOG(3, s, t, "IPV6CP: send ConfigReq\n");
 
-       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP, 0, 0, 0);
        if (!q) return;
 
        *q = ConfigReq;
@@ -1725,6 +1824,7 @@ static void sessionclear(sessionidt s)
 // kill a session now
 void sessionkill(sessionidt s, char *reason)
 {
+       bundleidt b;
 
        CSTAT(sessionkill);
 
@@ -1738,11 +1838,43 @@ void sessionkill(sessionidt s, char *reason)
        }
 
        session[s].die = TIME;
-       sessionshutdown(s, reason, 3, 0);  // close radius/routes, etc.
+       sessionshutdown(s, reason, CDN_ADMIN_DISC, TERM_ADMIN_RESET);  // close radius/routes, etc.
        if (sess_local[s].radius)
                radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
 
        LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
+       if ((b = session[s].bundle))
+       {
+               // This session was part of a bundle
+               bundle[b].num_of_links--;
+               LOG(3, s, 0, "MPPP: Dropping member link: %d from bundle %d\n",s,b);
+               if (bundle[b].num_of_links == 0)
+               {
+                       bundleclear(b);
+                       LOG(3, s, 0, "MPPP: Kill bundle: %d (No remaing member links)\n",b);
+               }
+               else
+               {
+                       // Adjust the members array to accomodate the new change
+                       uint8_t mem_num = 0;
+                       // It should be here num_of_links instead of num_of_links-1 (previous instruction "num_of_links--")
+                       if (bundle[b].members[bundle[b].num_of_links] != s)
+                       {
+                               uint8_t ml;
+                               for (ml = 0; ml<bundle[b].num_of_links; ml++)
+                               {
+                                       if (bundle[b].members[ml] == s)
+                                       {
+                                               mem_num = ml;
+                                               break;
+                                       }
+                               }
+                               bundle[b].members[mem_num] = bundle[b].members[bundle[b].num_of_links];
+                               LOG(3, s, 0, "MPPP: Adjusted member links array\n");
+                       }
+               }
+               cluster_send_bundle(b);
+       }
        sessionclear(s);
        cluster_send_session(s);
 }
@@ -1754,6 +1886,13 @@ static void tunnelclear(tunnelidt t)
        tunnel[t].state = TUNNELFREE;
 }
 
+static void bundleclear(bundleidt b)
+{
+       if (!b) return;
+       memset(&bundle[b], 0, sizeof(bundle[b]));
+       bundle[b].state = BUNDLEFREE;
+}
+
 // kill a tunnel now
 static void tunnelkill(tunnelidt t, char *reason)
 {
@@ -1803,7 +1942,7 @@ static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, cha
        // close session
        for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                if (session[s].tunnel == t)
-                       sessionshutdown(s, reason, 0, 0);
+                       sessionshutdown(s, reason, CDN_NONE, TERM_ADMIN_RESET);
 
        tunnel[t].state = TUNNELDIE;
        tunnel[t].die = TIME + 700; // Clean up in 70 seconds
@@ -2042,6 +2181,12 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                        int error = 0;
                        char *msg = 0;
 
+                       // default disconnect cause/message on receipt
+                       // of CDN (set to more specific value from
+                       // attribute 46 if present below).
+                       int disc_cause = TERM_NAS_REQUEST;
+                       char const *disc_reason = "Closed (Received CDN).";
+
                        // process AVPs
                        while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
                        {
@@ -2049,6 +2194,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                uint8_t *b = p;
                                uint8_t flags = *p;
                                uint16_t mtype;
+
                                if (n > l)
                                {
                                        LOG(1, s, t, "Invalid length in AVP\n");
@@ -2185,17 +2331,13 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                        }
                                        break;
                                case 3:     // framing capabilities
-//                                     LOG(4, s, t, "Framing capabilities\n");
                                        break;
                                case 4:     // bearer capabilities
-//                                     LOG(4, s, t, "Bearer capabilities\n");
                                        break;
                                case 5:         // tie breaker
                                        // We never open tunnels, so we don't care about tie breakers
-//                                     LOG(4, s, t, "Tie breaker\n");
                                        continue;
                                case 6:     // firmware revision
-//                                     LOG(4, s, t, "Firmware revision\n");
                                        break;
                                case 7:     // host name
                                        memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
@@ -2350,6 +2492,84 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                        memcpy(session[s].random_vector, b, n);
                                        session[s].random_vector_length = n;
                                        break;
+                               case 46:    // ppp disconnect cause
+                                       if (n >= 5)
+                                       {
+                                               uint16_t code = ntohs(*(uint16_t *) b);
+                                               uint16_t proto = ntohs(*(uint16_t *) (b + 2));
+                                               uint8_t dir = *(b + 4);
+
+                                               LOG(4, s, t, "   PPP disconnect cause "
+                                                       "(code=%u, proto=%04X, dir=%u, msg=\"%.*s\")\n",
+                                                       code, proto, dir, n - 5, b + 5);
+
+                                               switch (code)
+                                               {
+                                               case 1: // admin disconnect
+                                                       disc_cause = TERM_ADMIN_RESET;
+                                                       disc_reason = "Administrative disconnect";
+                                                       break;
+                                               case 3: // lcp terminate
+                                                       if (dir != 2) break; // 1=peer (LNS), 2=local (LAC)
+                                                       disc_cause = TERM_USER_REQUEST;
+                                                       disc_reason = "Normal disconnection";
+                                                       break;
+                                               case 4: // compulsory encryption unavailable
+                                                       if (dir != 1) break; // 1=refused by peer, 2=local
+                                                       disc_cause = TERM_USER_ERROR;
+                                                       disc_reason = "Compulsory encryption refused";
+                                                       break;
+                                               case 5: // lcp: fsm timeout
+                                                       disc_cause = TERM_PORT_ERROR;
+                                                       disc_reason = "LCP: FSM timeout";
+                                                       break;
+                                               case 6: // lcp: no recognisable lcp packets received
+                                                       disc_cause = TERM_PORT_ERROR;
+                                                       disc_reason = "LCP: no recognisable LCP packets";
+                                                       break;
+                                               case 7: // lcp: magic-no error (possibly looped back)
+                                                       disc_cause = TERM_PORT_ERROR;
+                                                       disc_reason = "LCP: magic-no error (possible loop)";
+                                                       break;
+                                               case 8: // lcp: echo request timeout
+                                                       disc_cause = TERM_PORT_ERROR;
+                                                       disc_reason = "LCP: echo request timeout";
+                                                       break;
+                                               case 13: // auth: fsm timeout
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = "Authentication: FSM timeout";
+                                                       break;
+                                               case 15: // auth: unacceptable auth protocol
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = "Unacceptable authentication protocol";
+                                                       break;
+                                               case 16: // auth: authentication failed
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = "Authentication failed";
+                                                       break;
+                                               case 17: // ncp: fsm timeout
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = "NCP: FSM timeout";
+                                                       break;
+                                               case 18: // ncp: no ncps available
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = "NCP: no NCPs available";
+                                                       break;
+                                               case 19: // ncp: failure to converge on acceptable address
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = (dir == 1)
+                                                               ? "NCP: too many Configure-Naks received from peer"
+                                                               : "NCP: too many Configure-Naks sent to peer";
+                                                       break;
+                                               case 20: // ncp: user not permitted to use any address
+                                                       disc_cause = TERM_SERVICE_UNAVAILABLE;
+                                                       disc_reason = (dir == 1)
+                                                               ? "NCP: local link address not acceptable to peer"
+                                                               : "NCP: remote link address not acceptable";
+                                                       break;
+                                               }
+                                       }
+                                       break;
                                default:
                                        {
                                                static char e[] = "unknown AVP 0xXXXX";
@@ -2459,19 +2679,24 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                        if (amagic == 0) amagic = time_now;
                                        session[s].magic = amagic; // set magic number
                                        session[s].flags = aflags; // set flags received
-                                       session[s].mru = PPPMTU; // default
+                                       session[s].mru = PPPoE_MRU; // default
                                        controlnull(t); // ack
 
                                        // start LCP
                                        sess_local[s].lcp_authtype = config->radius_authprefer;
                                        sess_local[s].ppp_mru = MRU;
+
+                                       // Set multilink options before sending initial LCP packet
+                                       sess_local[s].mp_mrru = 1614;
+                                       sess_local[s].mp_epdis = config->bind_address ? config->bind_address : my_address;
+
                                        sendlcp(s, t);
                                        change_state(s, lcp, RequestSent);
                                        break;
 
                                case 14:      // CDN
                                        controlnull(t); // ack
-                                       sessionshutdown(s, "Closed (Received CDN).", 0, 0);
+                                       sessionshutdown(s, disc_reason, CDN_NONE, disc_cause);
                                        break;
                                case 0xFFFF:
                                        LOG(1, s, t, "Missing message type\n");
@@ -2588,6 +2813,23 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
                        processipin(s, t, p, l);
                }
+               else if (proto == PPPMP)
+               {
+                       if (session[s].die)
+                       {
+                               LOG(4, s, t, "Session %d is closing.  Don't process PPP packets\n", s);
+                               return;              // closing session, PPP not processed
+                       }
+
+                       session[s].last_packet = time_now;
+                       if (session[s].walled_garden && !config->cluster_iam_master)
+                       {
+                               master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+                               return;
+                       }
+
+                       processmpin(s, t, p, l);
+               }
                else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
                {
                        if (session[s].die)
@@ -2607,29 +2849,9 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                }
                else if (session[s].ppp.lcp == Opened)
                {
-                       uint8_t buf[MAXETHER];
-                       uint8_t *q;
-                       int mru = session[s].mru;
-                       if (mru > sizeof(buf)) mru = sizeof(buf);
-
-                       l += 6;
-                       if (l > mru) l = mru;
-
-                       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
-                       if (!q) return;
-
-                       *q = ProtocolRej;
-                       *(q + 1) = ++sess_local[s].lcp_ident;
-                       *(uint16_t *)(q + 2) = htons(l);
-                       *(uint16_t *)(q + 4) = htons(proto);
-                       memcpy(q + 6, p, l - 6);
-
-                       if (proto == PPPIPV6CP)
-                               LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
-                       else
-                               LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
-
-                       tunnelsend(buf, l + (q - buf), t);
+                       session[s].last_packet = time_now;
+                       if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+                       protoreject(s, t, p, l, proto);
                }
                else
                {
@@ -2802,6 +3024,37 @@ static void regular_cleanups(double period)
                        continue;
                }
 
+               // check for timed out sessions
+               if (session[s].timeout)
+               {
+                       bundleidt bid = session[s].bundle;
+                       if (bid)
+                       {
+                               clockt curr_time = time_now;
+                               if (curr_time - bundle[bid].last_check >= 1)
+                               {
+                                       bundle[bid].online_time += (curr_time-bundle[bid].last_check)*bundle[bid].num_of_links;
+                                       bundle[bid].last_check = curr_time;
+                                       if (bundle[bid].online_time >= session[s].timeout)
+                                       {
+                                               int ses;
+                                               for (ses = bundle[bid].num_of_links - 1; ses >= 0; ses--)
+                                               {
+                                                       sessionshutdown(bundle[bid].members[ses], "Session timeout", CDN_ADMIN_DISC, TERM_SESSION_TIMEOUT);
+                                                       s_actions++;
+                                                       continue;
+                                               }
+                                       }
+                               }
+                       }
+                       else if (session[s].timeout <= time_now - session[s].opened)
+                       {
+                               sessionshutdown(s, "Session timeout", CDN_ADMIN_DISC, TERM_SESSION_TIMEOUT);
+                               s_actions++;
+                               continue;
+                       }
+               }
+
                // PPP timeouts
                if (sess_local[s].lcp.restart <= time_now)
                {
@@ -2821,7 +3074,7 @@ static void regular_cleanups(double period)
                                }
                                else
                                {
-                                       sessionshutdown(s, "No response to LCP ConfigReq.", 3, 0);
+                                       sessionshutdown(s, "No response to LCP ConfigReq.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
                                        STAT(session_timeout);
                                }
 
@@ -2850,7 +3103,7 @@ static void regular_cleanups(double period)
                                }
                                else
                                {
-                                       sessionshutdown(s, "No response to IPCP ConfigReq.", 3, 0);
+                                       sessionshutdown(s, "No response to IPCP ConfigReq.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
                                        STAT(session_timeout);
                                }
 
@@ -2916,7 +3169,7 @@ static void regular_cleanups(double period)
                // Drop sessions who have not responded within IDLE_TIMEOUT seconds
                if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
                {
-                       sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
+                       sessionshutdown(s, "No response to LCP ECHO requests.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
                        STAT(session_timeout);
                        s_actions++;
                        continue;
@@ -2928,13 +3181,13 @@ static void regular_cleanups(double period)
                {
                        uint8_t b[MAXETHER];
 
-                       uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
+                       uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP, 1, 0, 0);
                        if (!q) continue;
 
                        *q = EchoReq;
                        *(uint8_t *)(q + 1) = (time_now % 255); // ID
                        *(uint16_t *)(q + 2) = htons(8); // Length
-                       *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
+                       *(uint32_t *)(q + 4) = session[s].ppp.lcp == Opened ? htonl(session[s].magic) : 0; // Magic Number
 
                        LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
                                        (int)(time_now - session[s].last_packet));
@@ -2952,7 +3205,7 @@ static void regular_cleanups(double period)
                        if (a & CLI_SESS_KILL)
                        {
                                LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
-                               sessionshutdown(s, "Requested by administrator.", 3, 0);
+                               sessionshutdown(s, "Requested by administrator.", CDN_ADMIN_DISC, TERM_ADMIN_RESET);
                                a = 0; // dead, no need to check for other actions
                                s_actions++;
                        }
@@ -3184,9 +3437,12 @@ static void mainloop(void)
                e.events = EPOLLIN;
                i = 0;
 
-               d[i].type = FD_TYPE_CLI;
-               e.data.ptr = &d[i++];
-               epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
+               if (clifd >= 0)
+               {
+                       d[i].type = FD_TYPE_CLI;
+                       e.data.ptr = &d[i++];
+                       epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
+               }
 
                d[i].type = FD_TYPE_CLUSTER;
                e.data.ptr = &d[i++];
@@ -3264,6 +3520,7 @@ static void mainloop(void)
                if (n)
                {
                        struct sockaddr_in addr;
+                       struct in_addr local;
                        socklen_t alen;
                        int c, s;
                        int udp_ready = 0;
@@ -3280,6 +3537,7 @@ static void mainloop(void)
                        for (c = n, i = 0; i < c; i++)
                        {
                                struct event_data *d = events[i].data.ptr;
+
                                switch (d->type)
                                {
                                case FD_TYPE_CLI: // CLI connections
@@ -3306,20 +3564,30 @@ static void mainloop(void)
 
                                case FD_TYPE_CONTROL: // nsctl commands
                                        alen = sizeof(addr);
-                                       processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+                                       s = recvfromto(controlfd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
+                                       if (s > 0) processcontrol(buf, s, &addr, alen, &local);
                                        n--;
                                        break;
 
                                case FD_TYPE_DAE: // DAE requests
                                        alen = sizeof(addr);
-                                       processdae(buf, recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+                                       s = recvfromto(daefd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
+                                       if (s > 0) processdae(buf, s, &addr, alen, &local);
                                        n--;
                                        break;
 
                                case FD_TYPE_RADIUS: // RADIUS response
-                                       s = recv(radfds[d->index], buf, sizeof(buf), 0);
+                                       alen = sizeof(addr);
+                                       s = recvfrom(radfds[d->index], buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen);
                                        if (s >= 0 && config->cluster_iam_master)
-                                               processrad(buf, s, d->index);
+                                       {
+                                               if (addr.sin_addr.s_addr == config->radiusserver[0] ||
+                                                   addr.sin_addr.s_addr == config->radiusserver[1])
+                                                       processrad(buf, s, d->index);
+                                               else
+                                                       LOG(3, 0, 0, "Dropping RADIUS packet from unknown source %s\n",
+                                                               fmtaddr(addr.sin_addr.s_addr, 0));
+                                       }
 
                                        n--;
                                        break;
@@ -3628,6 +3896,16 @@ static void initdata(int optdebug, char *optconfig)
                LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
                exit(1);
        }
+       if (!(bundle = shared_malloc(sizeof(bundlet) * MAXBUNDLE)))
+       {
+               LOG(0, 0, 0, "Error doing malloc for bundles: %s\n", strerror(errno));
+               exit(1);
+       }
+       if (!(frag = shared_malloc(sizeof(fragmentationt) * MAXBUNDLE)))
+       {
+               LOG(0, 0, 0, "Error doing malloc for fragmentations: %s\n", strerror(errno));
+               exit(1);
+       }
        if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
        {
                LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
@@ -3674,6 +3952,7 @@ static void initdata(int optdebug, char *optconfig)
        memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
 
        memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
+       memset(bundle, 0, sizeof(bundlet) * MAXBUNDLE);
        memset(session, 0, sizeof(sessiont) * MAXSESSION);
        memset(radius, 0, sizeof(radiust) * MAXRADIUS);
        memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
@@ -3691,6 +3970,10 @@ static void initdata(int optdebug, char *optconfig)
        for (i = 1; i < MAXTUNNEL; i++)
                tunnel[i].state = TUNNELUNDEF;  // mark it as not filled in.
 
+       for (i = 1; i < MAXBUNDLE; i++) {
+               bundle[i].state = BUNDLEUNDEF;
+       }
+
        if (!*hostname)
        {
                // Grab my hostname unless it's been specified
@@ -3965,7 +4248,7 @@ static void initippool()
                else
                {
                        // It's a single ip address
-                       add_to_ip_pool(inet_addr(pool), 0);
+                       add_to_ip_pool(ntohl(inet_addr(pool)), 0);
                }
        }
        fclose(f);
@@ -4311,12 +4594,15 @@ static void update_config()
 #define L2TP_HDRS              (20+8+6+4)      // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
 #define TCP_HDRS               (20+20)         // TCP encapsulation: ip + tcp
 
-       if (config->l2tp_mtu <= 0)              config->l2tp_mtu = PPPMTU;
+       if (config->l2tp_mtu <= 0)              config->l2tp_mtu = 1500; // ethernet default
        else if (config->l2tp_mtu < MINMTU)     config->l2tp_mtu = MINMTU;
        else if (config->l2tp_mtu > MAXMTU)     config->l2tp_mtu = MAXMTU;
 
        // reset MRU/MSS globals
        MRU = config->l2tp_mtu - L2TP_HDRS;
+       if (MRU > PPPoE_MRU)
+               MRU = PPPoE_MRU;
+
        MSS = MRU - TCP_HDRS;
 
        // Update radius
@@ -4501,7 +4787,7 @@ int sessionsetup(sessionidt s, tunnelidt t)
                if (!session[s].ip)
                {
                        LOG(0, s, t, "   No IP allocated.  The IP address pool is FULL!\n");
-                       sessionshutdown(s, "No IP addresses available.", 2, 7); // try another
+                       sessionshutdown(s, "No IP addresses available.", CDN_TRY_ANOTHER, TERM_SERVICE_UNAVAILABLE);
                        return 0;
                }
                LOG(3, s, t, "   No IP allocated.  Assigned %s from pool\n",
@@ -4512,6 +4798,14 @@ int sessionsetup(sessionidt s, tunnelidt t)
        // Make sure this is right
        session[s].tunnel = t;
 
+       // Join a bundle if the MRRU option is accepted
+       if (session[s].mrru > 0 && !session[s].bundle)
+       {
+               LOG(3, s, t, "This session can be part of multilink bundle\n");
+               if (join_bundle(s))
+                       cluster_send_bundle(session[s].bundle);
+       }
+
        // zap old sessions with same IP and/or username
        // Don't kill gardened sessions - doing so leads to a DoS
        // from someone who doesn't need to know the password
@@ -4528,8 +4822,21 @@ int sessionsetup(sessionidt s, tunnelidt t)
                                continue;
                        }
 
-                       if (config->allow_duplicate_users) continue;
-                       if (session[s].walled_garden || session[i].walled_garden) continue;
+                       if (config->allow_duplicate_users)
+                               continue;
+
+                       if (session[s].walled_garden || session[i].walled_garden)
+                               continue;
+
+                       // Allow duplicate sessions for guest account.
+                       if (*config->guest_user && !strcasecmp(user, config->guest_user))
+                               continue;
+
+                       // Allow duplicate sessions for multilink ones of the same bundle.
+                       if (session[s].bundle && session[i].bundle && session[s].bundle == session[i].bundle)
+                               continue;
+
+                       // Drop the new session in case of duplicate sessionss, not the old one.
                        if (!strcasecmp(user, session[i].user))
                                sessionkill(i, "Duplicate session for users");
                }
@@ -4888,7 +5195,7 @@ static void plugins_done()
                run_plugin_done(p);
 }
 
-static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen)
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local)
 {
        struct nsctl request;
        struct nsctl response;
@@ -5046,7 +5353,7 @@ static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int
        r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
        if (r > 0)
        {
-               sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
+               sendtofrom(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen, local);
                if (log_stream && config->debug >= 4)
                {
                        LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
@@ -5350,7 +5657,9 @@ int ip_filter(uint8_t *buf, int len, uint8_t filter)
 
                if (frag_offset)
                {
-                       if (!rule->frag || rule->action == FILTER_ACTION_DENY)
+                       // layer 4 deny rules are skipped
+                       if (rule->action == FILTER_ACTION_DENY &&
+                           (rule->src_ports.op || rule->dst_ports.op || rule->tcp_flag_op))
                                continue;
                }
                else