X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/442b04cea2db5efc9636bb6a7d5b7166dee8fb3c..0834bba08ed4f1e507320306dc682d7e62371af5:/l2tpns.c?ds=inline

diff --git a/l2tpns.c b/l2tpns.c
index d1c1337..694726d 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -53,11 +53,23 @@
 #include "bgp.h"
 #endif
 
+#ifdef LAC
+#include "l2tplac.h"
+#endif
+
+#ifdef LAC
+char * Vendor_name = "Linux L2TPNS";
+uint32_t call_serial_number = 0;
+#endif
+
 // Globals
 configt *config = NULL;		// all configuration
 int nlfd = -1;			// netlink socket
 int tunfd = -1;			// tun interface file handle. (network device)
 int udpfd = -1;			// UDP file handle
+#ifdef LAC
+int udplacfd = -1;		// UDP LAC file handle
+#endif
 int controlfd = -1;		// Control signal handle
 int clifd = -1;			// Socket listening for CLI connections.
 int daefd = -1;			// Socket listening for DAE connections.
@@ -102,6 +114,7 @@ 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.
+uint64_t time_now_ms = 0;		// Current time in milliseconds since epoch.
 static char time_now_string[64] = {0};	// Current time as a string.
 static int time_changed = 0;		// time_now changed
 char main_quit = 0;			// True if we're in the process of exiting.
@@ -159,8 +172,16 @@ config_descriptt config_values[] = {
 	CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
 	CONFIG("cli_bind_address", cli_bind_address, IPv4),
 	CONFIG("hostname", hostname, STRING),
+#ifdef BGP
 	CONFIG("nexthop_address", nexthop_address, IPv4),
 	CONFIG("nexthop6_address", nexthop6_address, IPv6),
+#endif
+	CONFIG("echo_timeout", echo_timeout, INT),
+	CONFIG("idle_echo_timeout", idle_echo_timeout, INT),
+#ifdef LAC
+	CONFIG("disable_lac_func", disable_lac_func, BOOL),
+	CONFIG("bind_portremotelns", bind_portremotelns, SHORT),
+#endif
 	{ NULL, 0, 0, 0 },
 };
 
@@ -221,13 +242,6 @@ 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
-
-// quit actions (master)
-#define QUIT_FAILOVER	1 // SIGTERM: exit when all control messages have been acked (for cluster failover)
-#define QUIT_SHUTDOWN	2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
-
 // return internal time (10ths since process startup), set f if given
 // as a side-effect sets time_now, and time_changed
 static clockt now(double *f)
@@ -240,6 +254,10 @@ static clockt now(double *f)
 	    time_now = t.tv_sec;
 	    time_changed++;
 	}
+
+	// Time in milliseconds
+	time_now_ms = (t.tv_sec * 1000) + (t.tv_usec/1000);
+
 	return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
 }
 
@@ -855,6 +873,24 @@ static void initudp(void)
 		exit(1);
 	}
 
+#ifdef LAC
+	// Tunnel to Remote LNS
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(config->bind_portremotelns);
+	udplacfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	setsockopt(udplacfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+	{
+		int flags = fcntl(udplacfd, F_GETFL, 0);
+		fcntl(udplacfd, F_SETFL, flags | O_NONBLOCK);
+	}
+	if (bind(udplacfd, (struct sockaddr *) &addr, sizeof(addr)) < 0)
+	{
+		LOG(0, 0, 0, "Error in UDP REMOTE LNS bind: %s\n", strerror(errno));
+		exit(1);
+	}
+#endif
+
 	// Intercept
 	snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 }
@@ -1175,8 +1211,11 @@ void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
 			LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
 		}
 	}
-
+#ifdef LAC
+	if (sendto((tunnel[t].isremotelns?udplacfd:udpfd), buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
+#else
 	if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
+#endif
 	{
 		LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
 				strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
@@ -1323,7 +1362,8 @@ static void update_session_out_stat(sessionidt s, sessiont *sp, int len)
 
 // process outgoing (to tunnel) IP
 //
-static void processipout(uint8_t *buf, int len)
+// (i.e. this routine writes to data[-8]).
+void processipout(uint8_t *buf, int len)
 {
 	sessionidt s;
 	sessiont *sp;
@@ -1462,6 +1502,14 @@ static void processipout(uint8_t *buf, int len)
 
 	if(session[s].bundle != 0 && bundle[session[s].bundle].num_of_links > 1)
 	{
+
+		if (!config->cluster_iam_master)
+		{
+			// The MPPP packets must be managed by the Master.
+			master_forward_mppp_packet(s, data, size);
+			return;
+		}
+
 		// Add on L2TP header
 		sessionidt members[MAXBUNDLESES];
 		bundleidt bid = session[s].bundle;
@@ -1483,7 +1531,7 @@ static void processipout(uint8_t *buf, int len)
 
 		if (nb_opened < 1)
 		{
-			LOG(2, s, t, "MPPP: PROCESSIPOUT ERROR, no session opened in bundle:%d\n", bid);
+			LOG(3, s, t, "MPPP: PROCESSIPOUT ERROR, no session opened in bundle:%d\n", bid);
 			return;
 		}
 
@@ -1492,58 +1540,70 @@ static void processipout(uint8_t *buf, int len)
 		s = members[b->current_ses];
 		t = session[s].tunnel;
 		sp = &session[s];
+		LOG(4, s, t, "MPPP: (1)Session number becomes: %d\n", s);
 
-		if ((num_of_links > 1) && (len > MINFRAGLEN))
+		if (num_of_links > 1)
 		{
-			LOG(4, s, t, "MPPP: (1)Session number becomes: %d\n", s);
-
-			//for rotate traffic among the member links
-			uint32_t divisor = num_of_links;
-			if (divisor > 2)
-				divisor--;
-
-			// Partition the packet to "num_of_links" fragments
-			uint32_t fraglen = len / divisor;
-			uint32_t last_fraglen = fraglen + len % divisor;
-			uint32_t remain = len;
-
-			// send the first packet
-			uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, fraglen, s, t, PPPIP, 0, bid, MP_BEGIN);
-			if (!p) return;
-			tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
+			if(len > MINFRAGLEN)
+			{
+				//for rotate traffic among the member links
+				uint32_t divisor = num_of_links;
+				if (divisor > 2)
+					divisor = divisor/2 + (divisor & 1);
+
+				// Partition the packet to "num_of_links" fragments
+				uint32_t fraglen = len / divisor;
+				uint32_t last_fraglen = fraglen + len % divisor;
+				uint32_t remain = len;
+
+				// send the first packet
+				uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, fraglen, s, t, PPPIP, 0, bid, MP_BEGIN);
+				if (!p) return;
+				tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
 
-			// statistics
-			update_session_out_stat(s, sp, fraglen);
+				// statistics
+				update_session_out_stat(s, sp, fraglen);
 
-			remain -= fraglen;
-			while (remain > last_fraglen)
-			{ 
+				remain -= fraglen;
+				while (remain > last_fraglen)
+				{
+					b->current_ses = (b->current_ses + 1) % num_of_links;
+					s = members[b->current_ses];
+					t = session[s].tunnel;
+					sp = &session[s];
+					LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
+					p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), fraglen, s, t, PPPIP, 0, bid, 0);
+					if (!p) return;
+					tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
+					update_session_out_stat(s, sp, fraglen);
+					remain -= fraglen;
+				}
+				// send the last fragment
 				b->current_ses = (b->current_ses + 1) % num_of_links;
 				s = members[b->current_ses];
 				t = session[s].tunnel;
 				sp = &session[s];
 				LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
-				p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), fraglen, s, t, PPPIP, 0, bid, 0);
+				p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), remain, s, t, PPPIP, 0, bid, MP_END);
 				if (!p) return;
-				tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
-				update_session_out_stat(s, sp, fraglen);
-				remain -= fraglen;
+				tunnelsend(fragbuf, remain + (p-fragbuf), t); // send it...
+				update_session_out_stat(s, sp, remain);
+				if (remain != last_fraglen)
+					LOG(3, s, t, "PROCESSIPOUT ERROR REMAIN != LAST_FRAGLEN, %d != %d\n", remain, last_fraglen);
+			}
+			else
+			{
+				// Send it as one frame
+				uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, len, s, t, PPPIP, 0, bid, MP_BOTH_BITS);
+				if (!p) return;
+				tunnelsend(fragbuf, len + (p-fragbuf), t); // send it...
+				LOG(4, s, t, "MPPP: packet sent as one frame\n");
+				update_session_out_stat(s, sp, len);
 			}
-			// send the last fragment
-			b->current_ses = (b->current_ses + 1) % num_of_links;
-			s = members[b->current_ses];
-			t = session[s].tunnel;
-			sp = &session[s];
-			LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
-			p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), remain, s, t, PPPIP, 0, bid, MP_END);
-			if (!p) return;
-			tunnelsend(fragbuf, remain + (p-fragbuf), t); // send it...
-			update_session_out_stat(s, sp, remain);
-			if (remain != last_fraglen)
-				LOG(3, s, t, "PROCESSIPOUT ERROR REMAIN != LAST_FRAGLEN, %d != %d\n", remain, last_fraglen);
 		}
-		else {
-			// Send it as one frame
+		else
+		{
+			// Send it as one frame (NO MPPP Frame)
 			uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, len, s, t, PPPIP, 0, 0, 0);
 			if (!p) return;
 			tunnelsend(fragbuf, len + (p-fragbuf), t); // send it...
@@ -2016,11 +2076,11 @@ void sessionshutdown(sessionidt s, char const *reason, int cdn_result, int cdn_e
 				{
 					uint8_t ml;
 					for(ml = 0; ml<bundle[b].num_of_links; ml++)
-							if(bundle[b].members[ml] == s)
-							{
-									mem_num = ml;
-									break;
-							}
+					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, session[s].tunnel, "MPPP: Adjusted member links array\n");
 
@@ -2181,6 +2241,18 @@ void sessionkill(sessionidt s, char *reason)
 	if (sess_local[s].radius)
 		radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
 
+#ifdef LAC
+	if (session[s].forwardtosession)
+	{
+		sessionidt sess = session[s].forwardtosession;
+		if (session[sess].forwardtosession == s)
+		{
+			// Shutdown the linked session also.
+			sessionshutdown(sess, reason, CDN_ADMIN_DISC, TERM_ADMIN_RESET);
+		}
+	}
+#endif
+
 	LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
 	sessionclear(s);
 	cluster_send_session(s);
@@ -2596,7 +2668,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 				case 0:     // message type
 					message = ntohs(*(uint16_t *) b);
 					mandatory = flags & 0x80;
-					LOG(4, s, t, "   Message type = %u (%s)\n", *b, l2tp_code(message));
+					LOG(4, s, t, "   Message type = %u (%s)\n", message, l2tp_code(message));
 					break;
 				case 1:     // result code
 					{
@@ -2691,6 +2763,15 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 					}
 					break;
 				case 13:    // Response
+#ifdef LAC
+					if (tunnel[t].isremotelns)
+					{
+						chapresponse = calloc(17, 1);
+						memcpy(chapresponse, b, (n < 17) ? n : 16);
+						LOG(3, s, t, "received challenge response from REMOTE LNS\n");
+					}
+					else
+#endif /* LAC */
 					// Why did they send a response? We never challenge.
 					LOG(2, s, t, "   received unexpected challenge response\n");
 					break;
@@ -2916,8 +2997,10 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 				{
 				case 1:       // SCCRQ - Start Control Connection Request
 					tunnel[t].state = TUNNELOPENING;
+					LOG(3, s, t, "Received SCCRQ\n");
 					if (main_quit != QUIT_SHUTDOWN)
 					{
+						LOG(3, s, t, "sending SCCRP\n");
 						controlt *c = controlnew(2); // sending SCCRP
 						control16(c, 2, version, 1); // protocol version
 						control32(c, 3, 3, 1); // framing
@@ -2934,13 +3017,47 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 				case 2:       // SCCRP
 					tunnel[t].state = TUNNELOPEN;
 					tunnel[t].lastrec = time_now;
+#ifdef LAC
+					LOG(3, s, t, "Received SCCRP\n");
+					if (main_quit != QUIT_SHUTDOWN)
+					{
+						if (tunnel[t].isremotelns && chapresponse)
+						{
+							hasht hash;
+
+							lac_calc_rlns_auth(t, 2, hash); // id = 2 (SCCRP)
+							// check authenticator
+							if (memcmp(hash, chapresponse, 16) == 0)
+							{
+								LOG(3, s, t, "sending SCCCN to REMOTE LNS\n");
+								controlt *c = controlnew(3); // sending SCCCN
+								controls(c, 7, hostname, 1); // host name
+								controls(c, 8, Vendor_name, 1); // Vendor name
+								control16(c, 2, version, 1); // protocol version
+								control32(c, 3, 3, 1); // framing Capabilities
+								control16(c, 9, t, 1); // assigned tunnel
+								controladd(c, 0, t); // send
+							}
+							else
+							{
+								tunnelshutdown(t, "Bad chap response from REMOTE LNS", 4, 0, 0);
+							}
+						}
+					}
+					else
+					{
+						tunnelshutdown(t, "Shutting down", 6, 0, 0);
+					}
+#endif /* LAC */
 					break;
 				case 3:       // SCCN
+					LOG(3, s, t, "Received SCCN\n");
 					tunnel[t].state = TUNNELOPEN;
 					tunnel[t].lastrec = time_now;
 					controlnull(t); // ack
 					break;
 				case 4:       // StopCCN
+					LOG(3, s, t, "Received StopCCN\n");
 					controlnull(t); // ack
 					tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
 					break;
@@ -2949,18 +3066,24 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 					break;
 				case 7:       // OCRQ
 					// TBA
+					LOG(3, s, t, "Received OCRQ\n");
 					break;
 				case 8:       // OCRO
 					// TBA
+					LOG(3, s, t, "Received OCRO\n");
 					break;
 				case 9:       // OCCN
 					// TBA
+					LOG(3, s, t, "Received OCCN\n");
 					break;
 				case 10:      // ICRQ
+					LOG(3, s, t, "Received ICRQ\n");
 					if (sessionfree && main_quit != QUIT_SHUTDOWN)
 					{
 						controlt *c = controlnew(11); // ICRP
 
+						LOG(3, s, t, "Sending ICRP\n");
+
 						s = sessionfree;
 						sessionfree = session[s].next;
 						memset(&session[s], 0, sizeof(session[s]));
@@ -2988,6 +3111,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
 					{
 						controlt *c = controlnew(14); // CDN
+						LOG(3, s, t, "Sending CDN\n");
 						if (!sessionfree)
 						{
 							STAT(session_overflow);
@@ -3001,9 +3125,26 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 					}
 					return;
 				case 11:      // ICRP
-					// TBA
+#ifdef LAC
+				LOG(3, s, t, "Received ICRP\n");
+				if (session[s].forwardtosession)
+				{
+					controlt *c = controlnew(12); // ICCN
+
+					session[s].opened = time_now;
+					session[s].tunnel = t;
+					session[s].far = asession;
+					session[s].last_packet = session[s].last_data = time_now;
+
+					control32(c, 19, 1, 1); // Framing Type
+					control32(c, 24, 10000000, 1); // Tx Connect Speed
+					controladd(c, asession, t); // send the message
+					LOG(3, s, t, "Sending ICCN\n");
+				}
+#endif /* LAC */
 					break;
 				case 12:      // ICCN
+					LOG(3, s, t, "Received ICCN\n");
 					if (amagic == 0) amagic = time_now;
 					session[s].magic = amagic; // set magic number
 					session[s].flags = aflags; // set flags received
@@ -3023,6 +3164,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 					break;
 
 				case 14:      // CDN
+					LOG(3, s, t, "Received CDN\n");
 					controlnull(t); // ack
 					sessionshutdown(s, disc_reason, CDN_NONE, disc_cause);
 					break;
@@ -3073,6 +3215,16 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 			l -= 2;
 		}
 
+#ifdef LAC
+		if (session[s].forwardtosession)
+		{
+			LOG(5, s, t, "Forwarding data session to session %u\n", session[s].forwardtosession);
+			// Forward to LAC or Remote LNS session
+			lac_session_forward(buf, len, s, proto);
+			return;
+		}
+#endif /* LAC */
+
 		if (s && !session[s].opened)	// Is something wrong??
 		{
 			if (!config->cluster_iam_master)
@@ -3082,7 +3234,6 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 				return;
 			}
 
-
 			LOG(1, s, t, "UDP packet contains session which is not opened.  Dropping packet.\n");
 			STAT(tunnel_rx_errors);
 			return;
@@ -3191,6 +3342,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 }
 
 // read and process packet on tun
+// (i.e. this routine writes to buf[-8]).
 static void processtun(uint8_t * buf, int len)
 {
 	LOG_HEX(5, "Receive TUN Data", buf, len);
@@ -3464,8 +3616,8 @@ 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))
+		// Drop sessions who have not responded within IDLE_ECHO_TIMEOUT seconds
+		if (session[s].last_packet && (time_now - session[s].last_packet >= config->idle_echo_timeout))
 		{
 			sessionshutdown(s, "No response to LCP ECHO requests.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
 			STAT(session_timeout);
@@ -3474,7 +3626,7 @@ static void regular_cleanups(double period)
 		}
 
 		// No data in ECHO_TIMEOUT seconds, send LCP ECHO
-		if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
+		if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= config->echo_timeout) &&
 			(time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
 		{
 			uint8_t b[MAXETHER];
@@ -3740,8 +3892,13 @@ static int still_busy(void)
 # include "fake_epoll.h"
 #endif
 
+#ifdef LAC
+// the base set of fds polled: cli, cluster, tun, udp, control, dae, netlink, udplac
+#define BASE_FDS	8
+#else
 // the base set of fds polled: cli, cluster, tun, udp, control, dae, netlink
 #define BASE_FDS	7
+#endif
 
 // additional polled fds
 #ifdef BGP
@@ -3755,6 +3912,8 @@ static void mainloop(void)
 {
 	int i;
 	uint8_t buf[65536];
+	uint8_t *p = buf + 8; // for the hearder of the forwarded MPPP packet (see C_MPPP_FORWARD)
+	int size_bufp = sizeof(buf) - 8;
 	clockt next_cluster_ping = 0;	// send initial ping immediately
 	struct epoll_event events[BASE_FDS + RADIUS_FDS + EXTRA_FDS];
 	int maxevent = sizeof(events)/sizeof(*events);
@@ -3765,8 +3924,13 @@ static void mainloop(void)
 		exit(1);
 	}
 
+#ifdef LAC
+	LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d, nlfd=%d , udplacfd=%d\n",
+		clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd, nlfd, udplacfd);
+#else
 	LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d, nlfd=%d\n",
 		clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd, nlfd);
+#endif
 
 	/* setup our fds to poll for input */
 	{
@@ -3806,6 +3970,12 @@ static void mainloop(void)
 		d[i].type = FD_TYPE_NETLINK;
 		e.data.ptr = &d[i++];
 		epoll_ctl(epollfd, EPOLL_CTL_ADD, nlfd, &e);
+
+#ifdef LAC
+		d[i].type = FD_TYPE_UDPLAC;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, udplacfd, &e);
+#endif
 	}
 
 #ifdef BGP
@@ -3868,6 +4038,10 @@ static void mainloop(void)
 			socklen_t alen;
 			int c, s;
 			int udp_ready = 0;
+#ifdef LAC
+			int udplac_ready = 0;
+			int udplac_pkts = 0;
+#endif
 			int tun_ready = 0;
 			int cluster_ready = 0;
 			int udp_pkts = 0;
@@ -3905,7 +4079,9 @@ static void mainloop(void)
 				case FD_TYPE_CLUSTER:	cluster_ready++; break;
 				case FD_TYPE_TUN:	tun_ready++; break;
 				case FD_TYPE_UDP:	udp_ready++; break;
-
+#ifdef LAC
+				case FD_TYPE_UDPLAC:	udplac_ready++; break;
+#endif
 				case FD_TYPE_CONTROL: // nsctl commands
 					alen = sizeof(addr);
 					s = recvfromto(controlfd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
@@ -3995,13 +4171,31 @@ static void mainloop(void)
 						n--;
 					}
 				}
+#ifdef LAC
+				// L2TP REMOTE LNS
+				if (udplac_ready)
+				{
+					alen = sizeof(addr);
+					if ((s = recvfrom(udplacfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
+					{
+						if (!config->disable_lac_func)
+							processudp(buf, s, &addr);
 
+						udplac_pkts++;
+					}
+					else
+					{
+						udplac_ready = 0;
+						n--;
+					}
+				}
+#endif
 				// incoming IP
 				if (tun_ready)
 				{
-					if ((s = read(tunfd, buf, sizeof(buf))) > 0)
+					if ((s = read(tunfd, p, size_bufp)) > 0)
 					{
-						processtun(buf, s);
+						processtun(p, s);
 					    	tun_pkts++;
 					}
 					else
@@ -4033,9 +4227,13 @@ static void mainloop(void)
 
 			if (c >= config->multi_read_count)
 			{
+#ifdef LAC
+				LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster %d rmlns packets\n",
+					config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts, udplac_pkts);
+#else
 				LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
 					config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
-
+#endif
 				STAT(multi_read_exceeded);
 				more++;
 			}
@@ -4250,6 +4448,9 @@ static void initdata(int optdebug, char *optconfig)
 	config->ppp_max_failure = 5;
 	config->kill_timedout_sessions = 1;
 	strcpy(config->random_device, RANDOMDEVICE);
+	// Set default value echo_timeout and idle_echo_timeout
+	config->echo_timeout = ECHO_TIMEOUT;
+	config->idle_echo_timeout = IDLE_ECHO_TIMEOUT;
 
 	log_stream = stderr;
 
@@ -4366,6 +4567,10 @@ static void initdata(int optdebug, char *optconfig)
 		exit(1);
 	}
 #endif /* BGP */
+
+#ifdef LAC
+	lac_initremotelnsdata();
+#endif
 }
 
 static int assign_ip_address(sessionidt s)
@@ -4652,7 +4857,11 @@ void snoop_send_packet(uint8_t *packet, uint16_t size, in_addr_t destination, ui
 
 static int dump_session(FILE **f, sessiont *s)
 {
+#ifdef LAC
+	if (!s->opened || (!s->ip && !s->forwardtosession) || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
+#else
 	if (!s->opened || !s->ip || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
+#endif
 		return 1;
 
 	if (!*f)
@@ -5059,6 +5268,11 @@ static void update_config()
 	if (!config->radius_dae_port)
 		config->radius_dae_port = DAEPORT;
 
+#ifdef LAC
+	if(!config->bind_portremotelns)
+		config->bind_portremotelns = L2TPLACPORT;
+#endif
+
 	// re-initialise the random number source
 	initrandom(config->random_device);
 
@@ -5193,18 +5407,18 @@ int sessionsetup(sessionidt s, tunnelidt t)
 	LOG(3, s, t, "Doing session setup for session\n");
 
 	// Join a bundle if the MRRU option is accepted
-        if(session[s].mrru > 0 && session[s].bundle == 0)
-        {
-                LOG(3, s, t, "This session can be part of multilink bundle\n");
-                if (join_bundle(s) > 0)
-                	cluster_send_bundle(session[s].bundle);
+	if(session[s].mrru > 0 && session[s].bundle == 0)
+	{
+		LOG(3, s, t, "This session can be part of multilink bundle\n");
+		if (join_bundle(s) > 0)
+			cluster_send_bundle(session[s].bundle);
 		else
 		{
 			LOG(0, s, t, "MPPP: Mismaching mssf option with other sessions in bundle\n");
 			sessionshutdown(s, "Mismaching mssf option.", CDN_NONE, TERM_SERVICE_UNAVAILABLE);
 			return 0;
 		}
-        }
+	}
 
 	if (!session[s].ip)
 	{
@@ -5219,7 +5433,6 @@ int sessionsetup(sessionidt s, tunnelidt t)
 			fmtaddr(htonl(session[s].ip), 0));
 	}
 
-
 	// Make sure this is right
 	session[s].tunnel = t;
 
@@ -5232,13 +5445,14 @@ int sessionsetup(sessionidt s, tunnelidt t)
 		for (i = 1; i <= config->cluster_highest_sessionid; i++)
 		{
 			if (i == s) continue;
-			if (!session[s].opened) continue;
+			if (!session[s].opened) break;
 			// Allow duplicate sessions for multilink ones of the same bundle.
-                        if (session[s].bundle && session[i].bundle && session[s].bundle == session[i].bundle)
-                                continue;
+			if (session[s].bundle && session[i].bundle && session[s].bundle == session[i].bundle) continue;
+
 			if (ip == session[i].ip)
 			{
 				sessionkill(i, "Duplicate IP address");
+				cluster_listinvert_session(s, i);
 				continue;
 			}
 
@@ -5246,16 +5460,16 @@ int sessionsetup(sessionidt s, tunnelidt t)
 			if (session[s].walled_garden || session[i].walled_garden) continue;
 			// Guest change
 			int found = 0;
-                        int gu;
-                        for (gu = 0; gu < guest_accounts_num; gu++)
-                        {
-                                if (!strcasecmp(user, guest_users[gu]))
-                                {
-                                        found = 1;
-                                        break;
-                                }
-                        }
-                        if (found) continue;
+			int gu;
+			for (gu = 0; gu < guest_accounts_num; gu++)
+			{
+				if (!strcasecmp(user, guest_users[gu]))
+				{
+					found = 1;
+					break;
+				}
+			}
+			if (found) continue;
 
 			// Drop the new session in case of duplicate sessionss, not the old one.
 			if (!strcasecmp(user, session[i].user))
@@ -5266,7 +5480,7 @@ int sessionsetup(sessionidt s, tunnelidt t)
 	// no need to set a route for the same IP address of the bundle
 	if (!session[s].bundle || (bundle[session[s].bundle].num_of_links == 1))
 	{
-	    	int routed = 0;
+		int routed = 0;
 
 		// Add the route for this session.
 		for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
@@ -6112,3 +6326,52 @@ int ip_filter(uint8_t *buf, int len, uint8_t filter)
 	// default deny
     	return 0;
 }
+
+#ifdef LAC
+
+tunnelidt lac_new_tunnel()
+{
+	return new_tunnel();
+}
+
+void lac_tunnelclear(tunnelidt t)
+{
+	tunnelclear(t);
+}
+
+void lac_send_SCCRQ(tunnelidt t, uint8_t * auth, unsigned int auth_len)
+{
+	uint16_t version = 0x0100;	// protocol version
+
+	tunnel[t].state = TUNNELOPENING;
+
+	// Sent SCCRQ - Start Control Connection Request
+	controlt *c = controlnew(1); // sending SCCRQ
+	controls(c, 7, hostname, 1); // host name
+	controls(c, 8, Vendor_name, 1); // Vendor name
+	control16(c, 2, version, 1); // protocol version
+	control32(c, 3, 3, 1); // framing Capabilities
+	control16(c, 9, t, 1); // assigned tunnel
+	controlb(c, 11, (uint8_t *) auth, auth_len, 1);  // CHAP Challenge
+	LOG(3, 0, t, "Sent SCCRQ to REMOTE LNS\n");
+	controladd(c, 0, t); // send
+}
+
+void lac_send_ICRQ(tunnelidt t, sessionidt s)
+{
+	// Sent ICRQ  Incoming-call-request
+	controlt *c = controlnew(10); // ICRQ
+
+	control16(c, 14, s, 1); // assigned sesion
+	call_serial_number++;
+	control32(c, 15, call_serial_number, 1);  // call serial number
+	LOG(3, s, t, "Sent ICRQ to REMOTE LNS (far ID %u)\n", tunnel[t].far);
+	controladd(c, 0, t); // send
+}
+
+void lac_tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
+{
+	tunnelshutdown(t, reason, result, error, msg);
+}
+
+#endif