X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/17fd46618e32be940b963537b35ff265775a54c0..65270c4bd287b5a27c567ff1ebb595738d466b4d:/ppp.c?ds=inline

diff --git a/ppp.c b/ppp.c
index 8e1e844..8c1c9a3 100644
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.41 2005-01-13 07:57:39 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.101 2006-06-03 08:16:46 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -15,6 +15,8 @@ char const *cvs_id_ppp = "$Id: ppp.c,v 1.41 2005-01-13 07:57:39 bodea Exp $";
 #include "cluster.h"
 
 extern tunnelt *tunnel;
+extern bundlet *bundle;
+extern fragmentationt *frag;
 extern sessiont *session;
 extern radiust *radius;
 extern int tunfd;
@@ -23,14 +25,19 @@ extern uint32_t eth_tx;
 extern time_t time_now;
 extern configt *config;
 
-static void initccp(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);
 
 // Process PAP messages
-void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-	char user[129];
-	char pass[129];
+	char user[MAXUSER];
+	char pass[MAXPASS];
 	uint16_t hl;
+	uint16_t r;
 
 	CSTAT(processpap);
 
@@ -39,14 +46,16 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t 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(*(uint16_t *) (p + 2))) > 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;
 
@@ -54,27 +63,40 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	{
 		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;
 	}
 
 	{
 		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;
+			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
-		uint8_t b[MAXCONTROL];
+		uint8_t b[MAXETHER];
 		uint8_t id = p[1];
-		uint8_t *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
+		uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP, 0, 0, 0);
 		if (!p) return;
 
 		if (session[s].ip)
@@ -84,25 +106,21 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		p[1] = id;
 		*(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, s, t, "Already an IP allocated: %s (%d)\n",
 				fmtaddr(htonl(session[s].ip), 0), session[s].ip_pool_index);
-
-			session[s].flags &= ~SF_IPCP_ACKED;
 		}
 		else
 		{
-			LOG(1, 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, 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
-		uint16_t 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);
@@ -121,13 +139,13 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		free(packet.password);
 
 		radius[r].id = p[1];
-		LOG(3, s, t, "Sending login for %s/%s to radius\n", user, pass);
+		LOG(3, s, t, "Sending login for %s/%s to RADIUS\n", user, pass);
 		radiussend(r, RADIUSAUTH);
 	}
 }
 
 // Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 	uint16_t r;
 	uint16_t hl;
@@ -135,29 +153,21 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	CSTAT(processchap);
 
 	LOG_HEX(5, "CHAP", p, l);
-	r = session[s].radius;
-	if (!r)
-	{
-		LOG(1, s, t, "Unexpected CHAP message\n");
-
-// FIXME: Need to drop the session here.
-
-		STAT(tunnel_rx_errors);
-		return;
-	}
 
 	if (l < 4)
 	{
 		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(*(uint16_t *) (p + 2))) > 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;
 
@@ -165,20 +175,45 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	{
 		LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
 		STAT(tunnel_rx_errors);
+		sessionshutdown(s, "CHAP length mismatch.", 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, 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, 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;
@@ -187,7 +222,8 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	{
 		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
@@ -230,7 +266,7 @@ static void dumplcp(uint8_t *p, int l)
 	uint8_t *o = (p + 4);
 
 	LOG_HEX(5, "PPP LCP Packet", p, l);
-	LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_type((int)*p), ntohs( ((uint16_t *) p)[1]) );
+	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;
@@ -255,48 +291,54 @@ static void dumplcp(uint8_t *p, int l)
 		{
 			case 1: // Maximum-Receive-Unit
 				if (length == 4)
-					LOG(4, 0, 0, "    %s %d\n", lcp_type(type), ntohs(*(uint16_t *)(o + 2)));
+					LOG(4, 0, 0, "    %s %d\n", ppp_lcp_option(type), ntohs(*(uint16_t *)(o + 2)));
 				else
-					LOG(4, 0, 0, "    %s odd length %d\n", lcp_type(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)
 				{
 					uint32_t asyncmap = ntohl(*(uint32_t *)(o + 2));
-					LOG(4, 0, 0, "    %s %x\n", lcp_type(type), asyncmap);
+					LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), asyncmap);
 				}
 				else
-					LOG(4, 0, 0, "   %s odd length %d\n", lcp_type(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(*(uint16_t *)(o + 2));
-					LOG(4, 0, 0, "   %s 0x%x (%s)\n", lcp_type(type), proto,
-						proto == PPPCHAP ? "CHAP" :
-						proto == PPPPAP  ? "PAP"  : "UNKNOWN");
+					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, "   %s odd length %d\n", lcp_type(type), length);
+					LOG(4, 0, 0, "    %s odd length %d\n", ppp_lcp_option(type), length);
 				break;
 			case 4: // Quality-Protocol
 				{
 					uint32_t qp = ntohl(*(uint32_t *)(o + 2));
-					LOG(4, 0, 0, "    %s %x\n", lcp_type(type), qp);
+					LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), qp);
 				}
 				break;
 			case 5: // Magic-Number
 				if (length == 6)
 				{
 					uint32_t magicno = ntohl(*(uint32_t *)(o + 2));
-					LOG(4, 0, 0, "    %s %x\n", lcp_type(type), magicno);
+					LOG(4, 0, 0, "    %s %x\n", ppp_lcp_option(type), magicno);
 				}
 				else
-					LOG(4, 0, 0, "   %s odd length %d\n", lcp_type(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, "    %s\n", lcp_type(type));
+				LOG(4, 0, 0, "    %s\n", ppp_lcp_option(type));
 				break;
 			default:
 				LOG(2, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
@@ -307,12 +349,159 @@ static void dumplcp(uint8_t *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 && bundle[session[s].bundle].num_of_links > 1)
+		{
+			sessionidt first_ses = bundle[session[s].bundle].members[0];
+			LOG(3, s, t, "MPPP: Skipping IPCP negotiation for session:%d, first session of bundle is:%d\n", s, first_ses);
+			session[s].ip = session[first_ses].ip;
+			session[s].dns1 = session[first_ses].dns1;
+			session[s].dns2 = session[first_ses].dns2;
+			session[s].timeout = session[first_ses].timeout;
+			ipcp_open(s, t);
+		}
+		else
+		{
+			// 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);
+		}
+	}
+}
+
+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, uint8_t *p, uint16_t l)
+void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-	uint8_t b[MAXCONTROL];
+	uint8_t b[MAXETHER];
 	uint8_t *q = NULL;
-	uint32_t magicno = 0;
 	uint16_t hl;
 
 	CSTAT(processlcp);
@@ -333,19 +522,79 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	}
 	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, s, t, "LCP: Discarding ConfigAck\n");
-		session[s].flags |= SF_LCP_ACKED;
+		int x = l - 4;
+		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 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;
+		}
+
+		if (!session[s].ip && authtype)
+			sess_local[s].lcp_authtype = authtype;
+
+		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;
-
-		LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
-		if (config->debug > 3) dumplcp(p, l);
+		static uint8_t asyncmap[4] = { 0, 0, 0, 0 }; // all zero
+		static uint8_t authproto[5];
+		int changed = 0;
 
 		while (x > 2)
 		{
@@ -356,348 +605,1326 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 			switch (type)
 			{
 				case 1: // Maximum-Receive-Unit
-					session[s].mru = ntohs(*(uint16_t *)(o + 2));
+					{
+						uint16_t mru = ntohs(*(uint16_t *)(o + 2));
+						if (mru >= MINMTU)
+						{
+							session[s].mru = mru;
+							changed++;
+							break;
+						}
+
+						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));
+					}
 					break;
 
 				case 2: // Async-Control-Character-Map
 					if (!ntohl(*(uint32_t *)(o + 2))) // all bits zero is OK
 						break;
 
-					if (response && *response != ConfigNak) // rej already queued
-						break;
-
-					LOG(2, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
-					if (!response)
-					{
-						q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP);
-						if (!q) break;
-						*q = ConfigNak;
-						q += 4;
-					}
-
-					if ((q - b + 11) > sizeof(b))
-					{
-						LOG(2, s, t, "LCP overflow for asyncmap ConfigNak.\n");
-						break;
-					}
-
-					*q++ = type;
-					*q++ = 6;
-					memset(q, 0, 4); // asyncmap 0
-					q += 4;
-					*((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
+					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(*(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, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+						LOG(3, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
 
-						if (!response)
-						{
-							q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP);
-							if (!q) break;
-							*q = ConfigNak;
-							q += 4;
-						}
+						alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
+						if (alen < 2) break; // paranoia
 
-						if ((q - b + length) > sizeof(b))
+						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)
 						{
-							LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
-							break;
+							// 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);
-						*(uint16_t *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
-						q += length;
-						*((uint16_t *) (response + 2)) = htons(q - response);
+						break;
 					}
 					break;
 
-				case 5: // Magic-Number
-					magicno = ntohl(*(uint32_t *)(o + 2));
-					break;
-
 				case 4: // Quality-Protocol
+				case 5: // Magic-Number
 				case 7: // Protocol-Field-Compression
 				case 8: // Address-And-Control-Field-Compression
 					break;
 
-				default: // Reject any unknown options
-					LOG(2, 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 = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP);
-						if (!q) break;
-						*q = ConfigRej;
-						q += 4;
+						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);
 					}
-
-					if ((q - b + length) > sizeof(b))
+					break;
+					
+				case 18: // Multilink Short Sequence Number Header Format
 					{
-						LOG(2, s, t, "LCP overflow for ConfigRej (type=%d).\n", type);
-						break;
+						session[s].mssf = 1;
+						changed++;
+						LOG(3, s, t, "    Received PPP LCP option MSSN format\n");
+					}
+					break;
+					
+				case 19: // Multilink Endpoint Discriminator
+					{
+						uint8_t epdis_class = o[2];
+						int addr;
+
+						session[s].epdis.addr_class = epdis_class;
+						session[s].epdis.length = length - 3;
+						if (session[s].epdis.length > 20)
+						{
+							LOG(1, s, t, "Error: received EndDis Address Length more than 20: %d\n", session[s].epdis.length);
+							session[s].epdis.length = 20;
+						}
+
+						for (addr = 0; addr < session[s].epdis.length; addr++)
+							session[s].epdis.address[addr] = o[3+addr];
+
+						changed++;
+
+						switch (epdis_class)
+						{
+						case LOCALADDR:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis Local Address Class: %d\n",epdis_class);
+							break;
+						case IPADDR:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis IP Address Class: %d\n",epdis_class);
+							break;
+						case IEEEMACADDR:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis IEEE MAC Address Class: %d\n",epdis_class);
+							break;
+						case PPPMAGIC:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis PPP Magic No Class: %d\n",epdis_class);
+							break;
+						case PSNDN:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis PSND No Class: %d\n",epdis_class);
+							break;
+						default:
+							LOG(3, s, t, "    Received PPP LCP option Multilink EndDis NULL Class %d\n",epdis_class);
+						}
 					}
+					break;
 
-					memcpy(q, o, length);
-					q += length;
-					*((uint16_t *) (response + 2)) = htons(q - response); // LCP header 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 = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-			if (!q) return;
-			*q = ConfigAck;
+			l = q - response; // LCP packet length
+			*((uint16_t *) (response + 2)) = htons(l); // update header
 		}
-
-		LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response));
-		tunnelsend(b, l + (q - b), t);
-
-		if (!(session[s].flags & SF_LCP_ACKED))
-			initlcp(t, s);
-	}
-	else if (*p == ConfigNak)
-	{
-		LOG(1, s, t, "Remote end sent a ConfigNak.  Ignoring\n");
-		if (config->debug > 3) dumplcp(p, l);
-		return ;
-	}
-	else if (*p == TerminateReq)
-	{
-		LOG(3, s, t, "LCP: Received TerminateReq.  Sending TerminateAck\n");
-		*p = TerminateAck;	// close
-		q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
-		if (!q) return;
-		tunnelsend(b, l + (q - b), t); // send it
-		sessionshutdown(s, "Remote end closed connection.");
-	}
-	else if (*p == TerminateAck)
-	{
-		sessionshutdown(s, "Connection closed.");
-	}
-	else if (*p == EchoReq)
-	{
-		LOG(5, s, t, "LCP: Received EchoReq.  Sending EchoReply\n");
-		*p = EchoReply;		// reply
-		*(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number
-		q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-		if (!q) return;
-		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)
-	{
-		*p = CodeRej;
-		if (l > MAXCONTROL)
+		else
 		{
-			LOG(1, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
-			l = 1400;
+			// Send packet back as ConfigAck
+			response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP, 0, 0, 0);
+			if (!response) return;
+			*response = ConfigAck;
 		}
-		q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-		if (!q) return;
-		LOG_HEX(5, "LCPIdentRej", q, l + 4);
-		tunnelsend(b, 12 + 4 + l, t);
-	}
-	else
-	{
-		LOG(1, s, t, "Unexpected LCP code %d\n", *p);
-		STAT(tunnel_rx_errors);
-		return ;
-	}
-}
 
-// find a PPP option, returns point to option, or 0 if not found
-static uint8_t *findppp(uint8_t *b, uint8_t mtype)
-{
-	uint16_t l = ntohs(*(uint16_t *) (b + 2));
-	if (l < 4)
-		return 0;
-	b += 4;
-	l -= 4;
-	while (l)
-	{
-		if (l < b[1] || !b[1])
-			return 0;		// faulty
-		if (*b == mtype)
-			return b;
-		l -= b[1];
-		b += b[1];
-	}
-	return 0;
-}
+		switch (session[s].ppp.lcp)
+		{
+		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;
 
-// Process IPCP messages
-void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
-{
-	uint16_t hl;
+		case Stopped:
+		    	initialise_restart_count(s, lcp);
+			sendlcp(s, t);
+			if (*response == ConfigAck)
+				change_state(s, lcp, AckSent);
+			else
+				change_state(s, lcp, RequestSent);
 
-	CSTAT(processipcp);
+			break;
 
-	LOG_HEX(5, "IPCP", p, l);
-	if (l < 5)
-	{
+		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;
+
+		default:
+		    	LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+			return;
+		}
+
+		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 == 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 != 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))
+			{
+				session[s].bundle = i;
+				bundle[i].mrru = session[s].mrru;
+				bundle[i].mssf = session[s].mssf;
+				if (session[s].epdis.length > 0)
+					setepdis(&bundle[i].epdis, session[s].epdis);
+
+				strcpy(bundle[i].user, session[s].user);
+				bundle[i].members[bundle[i].num_of_links] = s;
+				bundle[i].num_of_links++;
+				LOG(3, s, session[s].tunnel, "MPPP: Bundling additional line in bundle (%d), lines:%d\n",i,bundle[i].num_of_links);
+				return i;
+			}
+		}
+	}
+
+	// No previously created bundle was found for this session, so create a new one
+	if (!(b = new_bundle())) return 0;
+
+	session[s].bundle = b;
+	bundle[b].mrru = session[s].mrru;
+	bundle[b].mssf = session[s].mssf;
+	if (session[s].epdis.length > 0)
+		setepdis(&bundle[b].epdis, session[s].epdis);
+
+	strcpy(bundle[b].user, session[s].user);
+	bundle[b].members[0] = s;
+	LOG(3, s, session[s].tunnel, "MPPP: Created a new bundle (%d)\n", b);
+	return b;
+}
+
+static int epdiscmp(epdist ep1, epdist ep2)
+{
+	int ad;
+	if (ep1.length != ep2.length)
+		return 0;
+
+	if (ep1.addr_class != ep2.addr_class)
+		return 0;
+
+	for (ad = 0; ad < ep1.length; ad++)
+		if (ep1.address[ad] != ep2.address[ad])
+			return 0;
+
+	return 1;
+}
+
+static void setepdis(epdist *ep1, epdist ep2)
+{
+	int ad;
+	ep1->length = ep2.length;
+	ep1->addr_class = ep2.addr_class;
+	for (ad = 0; ad < ep2.length; ad++)
+		ep1->address[ad] = ep2.address[ad];
+}
+
+static bundleidt new_bundle()
+{
+	bundleidt i;
+	for (i = 1; i < MAXBUNDLE; i++)
+	{
+		if (bundle[i].state == BUNDLEFREE)
+		{
+			LOG(4, 0, 0, "MPPP: Assigning bundle ID %d\n", i);
+			bundle[i].num_of_links = 1;
+			bundle[i].last_check = time_now;	// Initialize last_check value
+			bundle[i].state = BUNDLEOPEN;
+			bundle[i].current_ses = -1;	// This is to enforce the first session 0 to be used at first
+			if (i > config->cluster_highest_bundleid)
+				config->cluster_highest_bundleid = i;
+			return i;
+		}
+	}
+	LOG(0, 0, 0, "MPPP: Can't find a free bundle! There shouldn't be this many in use!\n");
+	return 0;
+}
+
+static void ipcp_open(sessionidt s, tunnelidt t)
+{
+	LOG(3, s, t, "IPCP: Opened, session is now active\n");
+
+	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)
+	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)
+	{
+		switch (session[s].ppp.ipv6cp)
+		{
+		case Closed:
+		case Stopped:
+		case Closing:
+		case Stopping:
+		case RequestSent:
+		case AckReceived:
+		case AckSent:
+		    	break;
+
+		case Opened:
+		    	zero_restart_count(s, ipv6cp);
+			change_state(s, ipv6cp, Closing);
+			break;
+
+		default:
+		    	LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp));
+			return;
+		}
+
+		*p = TerminateAck;	// send ack
+		q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP, 0, 0, 0);
+		if (!q) return;
+
+		LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
+		tunnelsend(b, l + (q - b), t); // send it
+	}
+	else if (*p != CodeRej)
+	{
+		ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
+	}
+}
+
+// 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)
+{
+	in_addr_t ip;
+
+	CSTAT(processipin);
+
+	LOG_HEX(5, "IP", p, l);
+
+	if (l < 20)
+	{
+		LOG(1, s, t, "IP packet too short %d\n", l);
+		STAT(tunnel_rx_errors);
+		return ;
+	}
+
+	ip = ntohl(*(uint32_t *)(p + 12));
+
+	if (l > MAXETHER)
 	{
-		LOG(1, 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
-		uint16_t 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);
+	}
 
-		LOG(3, s, t, "IPCP Acked, session is now active\n");
+	// Add on the tun header
+	p -= 4;
+	*(uint32_t *) p = htonl(PKTIP);
+	l += 4;
+
+	// Are we throttled and a slave?
+	if (session[s].tbf_in && !config->cluster_iam_master) {
+		// Pass it to the master for handling.
+		master_throttle_packet(session[s].tbf_in, p, l);
+		return;
+	}
+
+	// Are we throttled and a master??
+	if (session[s].tbf_in && config->cluster_iam_master) {
+		// Actually handle the throttled packets.
+		tbf_queue_packet(session[s].tbf_in, p, l);
+		return;
+	}
 
-		// clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers
-		session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED);
+	// send to ethernet
+	if (tun_write(p, l) < 0)
+	{
+		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;
 	}
-	if (*p != ConfigReq)
+
+	p += 4;
+	l -= 4;
+
+	if (session[s].snoop_ip && session[s].snoop_port)
 	{
-		LOG(1, s, t, "Unexpected IPCP code %d\n", *p);
-		STAT(tunnel_rx_errors);
-		return ;
+		// Snooping this session
+		snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
 	}
-	LOG(4, s, t, "IPCP ConfigReq received\n");
 
-	if (!session[s].ip)
+	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++;
+
+	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;
+	uint8_t begin_frame;
+	uint8_t end_frame;
+	uint32_t seq_num;
+	uint32_t offset;
+
+	if (!b)
+	{
+		LOG(3, s, t, "MPPP: Invalid bundle id: 0\n");
+		return;
+	}
+
+	begin_frame = (*p & 0x80);
+	end_frame = (*p & 0x40);
+	if (session[s].mssf)
 	{
-		LOG(3, s, t, "Waiting on radius reply\n");
-		return;			// have to wait on RADIUS reply
+		// Get 12 bit for seq number
+		uint16_t short_seq_num = ntohs((*(uint16_t *) p) & 0xFF0F);
+		uint16_t short_seq_num2 = short_seq_num >> 4;
+		p += 2;
+		l -= 2;
+		seq_num = short_seq_num2;
+		// After this point the pointer should be advanced 2 bytes
+		LOG(3, s, t, "MPPP: 12 bits, sequence number: %d, short1: %d, short2: %d\n",seq_num, short_seq_num, short_seq_num2);
 	}
-	// form a config reply quoting the IP in the session
+	else
 	{
-		uint8_t b[MAXCONTROL];
-		uint8_t *i, *q;
+		// Get 24 bit for seq number
+		p++;
+		seq_num = ntohl((*(uint32_t *) p) & 0xFFFFFF00);
+		seq_num = seq_num >> 8;
+		p += 3;
+		l -= 4;
+		// After this point the pointer should be advanced 4 bytes
+		LOG(4, s, t, "MPPP: 24 bits sequence number:%d\n",seq_num);
+	}
 
-		q = p + 4;
-		i = p + l;
-		while (q < i && q[1])
-		{
-			if (*q != 0x81 && *q != 0x83 && *q != 3)
-				break;
-			q += q[1];
-		}
-		if (q < i)
+	if (seq_num - bundle[b].offset < 0)
+	{
+		bundle[b].offset = 0;
+		bundle[b].pending_frag = 0;
+	}
+
+	offset = bundle[b].offset;
+	if (begin_frame)
+	{
+		// Check for previous non-assembled frames
+		int error = 0;
+		if (bundle[b].pending_frag)
 		{
-			// reject
-			uint16_t n = 4;
-			i = p + l;
-			if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+			uint32_t fn = bundle[b].seq_num_m - offset;
+			uint16_t cur_len;
+			bundle[b].pending_frag = 0;
+			// Check for array indexes
+			if (fn < 0 || fn > MAXFRAGNUM)
+			{
+				LOG(2, s, t, "ERROR: Index out of range fn:%d, bundle:%d\n",fn,b);
 				return;
+			}
 
-			*q = ConfigRej;
-			p += 4;
-			while (p < i && p[1])
+			if (seq_num-offset < 0 || seq_num-offset > MAXFRAGNUM)
 			{
-				if (*p != 0x81 && *p != 0x83 && *p != 3)
-				{
-					LOG(2, s, t, "IPCP reject %d\n", *p);
-					memcpy(q + n, p, p[1]);
-					n += p[1];
-				}
-				p += p[1];
+				LOG(2, s, t, "ERROR: Index out of range fn(last):%d, bundle:%d\n",fn,b);
+				return;
 			}
-			*(uint16_t *) (q + 2) = htons(n);
-			LOG(4, s, t, "Sending ConfigRej\n");
-			tunnelsend(b, n + (q - b), t); // send it
-		}
-		else
-		{
-			LOG(4, s, t, "Sending ConfigAck\n");
-			*p = ConfigAck;
-			if ((i = findppp(p, 0x81))) // Primary DNS address
+			/////////////////////////////////////////////////////
+			cur_len = 4;   // This is set to 4 to leave 4 bytes for function processipin
+			for (fn = bundle[b].seq_num_m - offset; fn < seq_num - offset; fn++)
 			{
-				if (*(uint32_t *) (i + 2) != htonl(session[s].dns1))
+				if (!frag[b].fragment[fn].length)
+				{
+					LOG(4, s, t, "MPPP: Found lost fragment while reassembling frame %d in (%d,%d)\n",fn, bundle[b].seq_num_m-offset, seq_num-offset);
+					error = 1;
+					break;
+				}
+
+				if (cur_len + frag[b].fragment[fn].length > MAXETHER)
 				{
-					*(uint32_t *) (i + 2) = htonl(session[s].dns1);
-					*p = ConfigNak;
-					LOG(5, s, t, "   DNS1 = %s\n",
-						fmtaddr(htonl(session[s].dns1), 0));
+					LOG(2, s, t, "MPPP: ERROR: very long frame after assembling %d\n", frag[b].fragment[fn].length+cur_len);
+					error = 1;
+					break;
 				}
+
+				memcpy(frag[b].reassembled_frame+cur_len, frag[b].fragment[fn].data, frag[b].fragment[fn].length);
+				cur_len += frag[b].fragment[fn].length; 
+				frag[b].fragment[fn].length = 0;      // Indicates that this fragment has been consumed
+				// This is usefull for compression
+				memset(frag[b].fragment[fn].data, 0, sizeof(frag[b].fragment[fn].data));
 			}
-			if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it)
+
+			if (!error)
 			{
-				if (*(uint32_t *) (i + 2) != htonl(session[s].dns2))
-				{
-					*(uint32_t *) (i + 2) = htonl(session[s].dns2);
-					*p = ConfigNak;
-					LOG(5, s, t, "   DNS2 = %s\n",
-						fmtaddr(htonl(session[s].dns2), 0));
-				}
+				frag[b].re_frame_len = cur_len;
+				// Process the resassembled frame
+				LOG(4, s, t, "MPPP: Process the reassembled frame, len=%d\n",cur_len);
+				processmpframe(s, t, frag[b].reassembled_frame, frag[b].re_frame_len, 1);
+				// Set reassembled frame length to zero after processing it
+				frag[b].re_frame_len = 0;
+				memset(frag[b].reassembled_frame, 0, sizeof(frag[b].reassembled_frame));
 			}
-			i = findppp(p, 3);		// IP address
-			if (!i || i[1] != 6)
+		}
+		//////////////////////////////////////////
+		bundle[b].seq_num_m = seq_num;
+		if (end_frame)
+		{
+			// Both bits are set
+			LOG(4, s, t, "MPPP: Both bits are set (Begin and End).\n");
+			processmpframe(s, t, p, l, 0);
+			// The maximum number of fragments is 1500
+			if (seq_num - bundle[b].offset >= 1400)
 			{
-				LOG(1, s, t, "No IP in IPCP request\n");
-				STAT(tunnel_rx_errors);
-				return ;
+				bundle[b].offset = seq_num;
+				LOG(4, s, t, "MPPP: Setting offset to: %d\n",bundle[b].offset);
 			}
-			if (*(uint32_t *) (i + 2) != htonl(session[s].ip))
+		}
+		else
+		{
+			bundle[b].pending_frag = 1;
+			// End bit is clear
+                	LOG(4, s, t, "MPPP: Push to receive buffer\n");
+                	// Push to the receive buffer
+			// Array indexes checking
+			if (seq_num-offset < 0 || seq_num-offset >= MAXFRAGNUM)
 			{
-				*(uint32_t *) (i + 2) = htonl(session[s].ip);
-				*p = ConfigNak;
-				LOG(4, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
-						fmtaddr(htonl(session[s].ip), 0));
+				LOG(2, s, t, "ERROR: Index out of range, push to receive buffer(1) seq:%d, offset:%d, bundle:%d\n",seq_num,offset,b);
+				return;
 			}
-			if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+			// Perform length checking
+			if (l > MAXFRAGLEN)
+			{
+				LOG(2, s, t, "MPPP: ERROR: very long fragment length (1)\n");
 				return;
-
-			tunnelsend(b, l + (q - b), t); // send it
+			}
+                	frag[b].fragment[seq_num - offset].length = l;
+                	memcpy(frag[b].fragment[seq_num - offset].data, p, l);
+		}
+	}
+	else
+	{
+		LOG(4, s, t, "MPPP: Push to receive buffer\n");
+		// Push to the receive buffer
+		// Array indexes checking
+		if (seq_num-offset < 0 || seq_num-offset >= MAXFRAGNUM)
+		{
+			LOG(2, s, t, "ERROR: Index out of range, push to receive buffer(2) seq:%d, offset:%d, bundle:%d\n",seq_num,offset,b);
+			return;
+		}
+		// Perform length checking
+		if (l > MAXFRAGLEN)
+		{
+			LOG(2, s, t, "MPPP: ERROR: very long fragment length (2).\n");
+			return;
 		}
+		frag[b].fragment[seq_num - offset].length = l;
+		memcpy(frag[b].fragment[seq_num - offset].data, p, l);
 	}
 }
 
-// process 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, uint8_t *p, uint16_t l)
+void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-	in_addr_t ip;
+	struct in6_addr ip;
+	in_addr_t ipv4;
 
-	CSTAT(processipin);
+	CSTAT(processipv6in);
 
-	LOG_HEX(5, "IP", p, l);
+	LOG_HEX(5, "IPv6", p, l);
 
-	ip = ntohl(*(uint32_t *)(p + 12));
+	ip = *(struct in6_addr *) (p + 8);
+	ipv4 = ntohl(*(uint32_t *)(p + 16));
 
 	if (l > MAXETHER)
 	{
@@ -706,28 +1933,43 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		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, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0));
+		char str[INET6_ADDRSTRLEN];
+		LOG(5, s, t, "Dropping packet with spoofed IP %s\n",
+				inet_ntop(AF_INET6, &ip, str, INET6_ADDRSTRLEN));
 		return;
 	}
 
-	// run access-list if any
-	if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
+	// 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;
-	*(uint32_t *) 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;
 	}
@@ -742,21 +1984,26 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		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_local[s].cin += l - 4;
-
+	increment_counter(&session[s].cin, &session[s].cin_wrap, l);
+	session[s].cin_delta += l;
 	session[s].pin++;
-	eth_tx += l - 4;
+
+	sess_local[s].cin += l;
+	sess_local[s].pin++;
+
+	eth_tx += l;
 
 	STAT(tun_tx_packets);
-	INC_STAT(tun_tx_bytes, l - 4);
+	INC_STAT(tun_tx_bytes, l);
 }
 
 //
@@ -776,19 +2023,24 @@ void send_ipin(sessionidt s, uint8_t *buf, int len)
 		return;
 	}
 
+	buf += 4;
+	len -= 4;
+
 	if (session[s].snoop_ip && session[s].snoop_port)
 	{
 		// Snooping this session
-		snoop_send_packet(buf + 4, len - 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_local[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, len - 4);
@@ -796,65 +2048,140 @@ void send_ipin(sessionidt s, uint8_t *buf, int len)
 
 
 // Process CCP messages
-void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
+void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
-	uint8_t b[MAXCONTROL];
+	uint8_t b[MAXETHER];
 	uint8_t *q;
 
 	CSTAT(processccp);
 
 	LOG_HEX(5, "CCP", p, l);
-	switch (l > 1 ? *p : 0)
+
+	if (session[s].ppp.phase < Network)
 	{
-	case ConfigAck:
-		session[s].flags |= SF_CCP_ACKED;
+	    	LOG(2, s, t, "CCP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase));
 		return;
+	}
 
-	case ConfigReq:
-		if (l < 6) // accept no compression
+	if (l < 1)
+	{
+		LOG(1, s, t, "Short CCP packet\n");
+		STAT(tunnel_rx_errors);
+	}
+
+	LOG(4, s, t, "CCP: recv %s\n", ppp_code(*p));
+	if (*p == ConfigAck)
+	{
+		switch (session[s].ppp.ccp)
 		{
-			*p = ConfigAck;
+		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 if (*p == ConfigReq)
+	{
+		if (l < 6) // accept no compression
+			*p = ConfigAck;
+		else // compression requested--reject
+			*p = ConfigRej;
 
-		// compression requested--reject
-		*p = ConfigRej;
+		q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP, 0, 0, 0);
+		if (!q) return;
 
-		// send CCP request for no compression for our end if not negotiated
-		if (!(session[s].flags & SF_CCP_ACKED))
-			initccp(t, s);
+		switch (session[s].ppp.ccp)
+		{
+		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;
 
-		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);
 
-	case TerminateReq:
-	    	*p = TerminateAck;
-		break;
+			break;
 
-	default:
-		if (l > 1)
-			LOG(1, s, t, "Unexpected CCP request code %d\n", *p);
-		else
-			LOG(1, s, t, "Short CCP packet\n");
+		case RequestSent:
+			if (*q == ConfigAck)
+				change_state(s, ccp, AckSent);
 
-		STAT(tunnel_rx_errors);
-		return;
-	}
+			break;
 
-	if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
-		return;
+		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);
 
-	tunnelsend(b, l + (q - b), t); // send it
+			break;
+
+		default:
+		    	LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp));
+			return;
+		}
+
+		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)
 {
-	uint8_t b[MAXCONTROL];
-	uint16_t r = session[s].radius;
+	uint8_t b[MAXETHER];
+	uint16_t r;
 	uint8_t *q;
 
 	CSTAT(sendchap);
 
+	r = radiusnew(s);
 	if (!r)
 	{
 		LOG(1, s, t, "No RADIUS to send challenge\n");
@@ -864,8 +2191,6 @@ void sendchap(tunnelidt t, sessionidt s)
 
 	LOG(1, s, t, "Send CHAP challenge\n");
 
-	// new challenge
-	random_data(radius[r].auth, sizeof(radius[r].auth));
 	radius[r].chap = 1;		// CHAP not PAP
 	radius[r].id++;
 	if (radius[r].state != RADIUSCHAP)
@@ -875,102 +2200,240 @@ void sendchap(tunnelidt t, sessionidt s)
 	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);
+	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
+	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
-uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionidt s, uint16_t mtype)
+uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits)
 {
-	if (size < 12) // Need more space than this!!
+	uint16_t hdr = 0x0002; // L2TP with no options
+	uint16_t type = mtype;
+	uint8_t *start = b;
+
+	if (size < 16) // Need more space than this!!
 	{
-		static int backtrace_count = 0;
 		LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
-		log_backtrace(backtrace_count, 5)
 		return NULL;
 	}
 
-	*(uint16_t *) (b + 0) = htons(0x0002); // L2TP with no options
+	if (prio) hdr |= 0x0100; // set priority bit
+
+	*(uint16_t *) (b + 0) = htons(hdr);
 	*(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel
 	*(uint16_t *) (b + 4) = htons(session[s].far); // session
 	b += 6;
-	if (mtype == PPPLCP || !(session[s].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))
 	{
 		*(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
 	{
-		*(uint16_t *) b = htons(mtype);
+		*(uint16_t *) b = htons(type);
 		b += 2;
 	}
 
-	if (l + 12 > size)
+	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 & 0xFF0F)|bits_send);
+			b += 2;
+		}
+		else
+		{
+			*(uint32_t *) b = htonl(bundle[bid].seq_num_t);
+			// Set the multilink bits
+			*b = mp_bits;
+			b += 4;
+		}
+
+		bundle[bid].seq_num_t++;
+
+		// Add the message type if this fragment has the begin bit set
+		if (mp_bits & MP_BEGIN)
+		{
+			//*b++ = mtype; // The next two lines are instead of this 
+			*(uint16_t *) b = htons(mtype); // Message type
+			b += 2;
+		}
+	}
+
+	if ((b - start) + l > size)
 	{
-		static int backtrace_count = 0;
-		LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
-		log_backtrace(backtrace_count, 5)
+		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;
 }
 
-// Send initial LCP ConfigReq for PAP, set magic no.
-void initlcp(tunnelidt t, sessionidt s)
+static int add_lcp_auth(uint8_t *b, int size, int authtype)
+{
+	int len = 0;
+	if ((authtype == AUTHCHAP && size < 5) || size < 4)
+		return 0;
+
+	*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
+	{
+		LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype);
+	}
+
+	return len;
+}
+
+// Send LCP ConfigReq for MRU, authentication type and magic no
+void sendlcp(sessionidt s, tunnelidt t)
 {
-	char b[500], *q;
+	uint8_t b[500], *q, *l;
+	int authtype = sess_local[s].lcp_authtype;
 
-	if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
+        if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP, 0, 0, 0)))
 		return;
 
-	LOG(4, s, t, "Sending LCP ConfigReq for PAP\n");
-	*q = ConfigReq;
-	*(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID
-	*(uint16_t *)(q + 2) = htons(14); // Length
-	*(uint8_t *)(q + 4) = 5;
-	*(uint8_t *)(q + 5) = 6;
-	*(uint32_t *)(q + 6) = htonl(session[s].magic);
-	*(uint8_t *)(q + 10) = 3;
-	*(uint8_t *)(q + 11) = 4;
-	*(uint16_t *)(q + 12) = htons(PPPPAP); // PAP
-
-	LOG_HEX(5, "PPPLCP", q, 14);
-	tunnelsend(b, (q - b) + 14, t);
+        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;
+	}
+
+	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 request for no compression
-static void initccp(tunnelidt t, sessionidt s)
+void sendccp(sessionidt s, tunnelidt t)
 {
-	char b[500], *q;
+	uint8_t b[500], *q;
 
-	if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP)))
+	if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPCCP, 0, 0, 0)))
 		return;
 
-	LOG(4, s, t, "Sending CCP ConfigReq for no compression\n");
+	LOG(3, s, t, "CCP: send ConfigReq (no compression)\n");
+
 	*q = ConfigReq;
-	*(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID
+	*(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);
 }