X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/1be4c47f885820ba815e8c52330a22b0e6201826..17552803b25d07f0df3add1ede410ec72afa099c:/ppp.c?ds=sidebyside

diff --git a/ppp.c b/ppp.c
index 078696d..2baad57 100644
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.23 2004/11/09 05:42:53 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.33 2004/11/29 02:17:18 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -21,9 +21,9 @@ extern int tunfd;
 extern char hostname[];
 extern u32 eth_tx;
 extern time_t time_now;
-extern struct configt *config;
+extern configt *config;
 
-void sendccp(tunnelidt t, sessionidt s);
+static void initccp(tunnelidt t, sessionidt s);
 
 // Process PAP messages
 void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
@@ -37,14 +37,14 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	LOG_HEX(5, "PAP", p, l);
 	if (l < 4)
 	{
-		LOG(1, 0, s, t, "Short PAP %u bytes\n", l);
+		LOG(1, s, t, "Short PAP %u bytes\n", l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
 
 	if ((hl = ntohs(*(u16 *) (p + 2))) > l)
 	{
-		LOG(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l);
+		LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -52,7 +52,7 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 
 	if (*p != 1)
 	{
-		LOG(1, 0, s, t, "Unexpected PAP code %d\n", *p);
+		LOG(1, s, t, "Unexpected PAP code %d\n", *p);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -67,7 +67,7 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		if (*b && *b < sizeof(pass))
 			memcpy(pass, b + 1, *b);
 		pass[*b] = 0;
-		LOG(3, 0, s, t, "PAP login %s/%s\n", user, pass);
+		LOG(3, s, t, "PAP login %s/%s\n", user, pass);
 	}
 	if (session[s].ip || !session[s].radius)
 	{
@@ -75,10 +75,8 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		u8 b[MAXCONTROL];
 		u8 id = p[1];
 		u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
-		if (!p) {	// Failed to make ppp header!
-			LOG(1,0,0,0, "Failed to make PPP header in process pap!\n");
-			return;
-		}
+		if (!p) return;
+
 		if (session[s].ip)
 			*p = 2;			// ACK
 		else
@@ -88,14 +86,16 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		p[4] = 0;			// no message
 		if (session[s].ip)
 		{
-			LOG(3, session[s].ip, s, t, "Already an IP allocated: %s (%d)\n", inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
+			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, 0, s, t, "No radius session available to authenticate session...\n");
+			LOG(1, s, t, "No radius session available to authenticate session...\n");
 		}
-		LOG(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
+		LOG(3, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
 		tunnelsend(b, 5 + (p - b), t); // send it
 	}
 	else
@@ -108,7 +108,7 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		run_plugins(PLUGIN_PRE_AUTH, &packet);
 		if (!packet.continue_auth)
 		{
-			LOG(3, 0, s, t, "A plugin rejected PRE_AUTH\n");
+			LOG(3, s, t, "A plugin rejected PRE_AUTH\n");
 			if (packet.username) free(packet.username);
 			if (packet.password) free(packet.password);
 			return;
@@ -121,7 +121,7 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		free(packet.password);
 
 		radius[r].id = p[1];
-		LOG(3, 0, s, t, "Sending login for %s/%s to radius\n", user, pass);
+		LOG(3, s, t, "Sending login for %s/%s to radius\n", user, pass);
 		radiussend(r, RADIUSAUTH);
 	}
 }
@@ -138,7 +138,7 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	r = session[s].radius;
 	if (!r)
 	{
-		LOG(1, 0, s, t, "Unexpected CHAP message\n");
+		LOG(1, s, t, "Unexpected CHAP message\n");
 
 // FIXME: Need to drop the session here.
 
@@ -148,14 +148,14 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 
 	if (l < 4)
 	{
-		LOG(1, 0, s, t, "Short CHAP %u bytes\n", l);
+		LOG(1, s, t, "Short CHAP %u bytes\n", l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
 
 	if ((hl = ntohs(*(u16 *) (p + 2))) > l)
 	{
-		LOG(1, 0, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
+		LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -163,20 +163,20 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 
 	if (*p != 2)
 	{
-		LOG(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
+		LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
 		STAT(tunnel_rx_errors);
 		return;
 	}
 	if (p[1] != radius[r].id)
 	{
-		LOG(1, 0, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
+		LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
 
 	if (l < 5 || p[4] != 16)
 	{
-		LOG(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
+		LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -185,7 +185,7 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	p += 5;
 	if (l < 16 || l - 16 >= sizeof(session[s].user))
 	{
-		LOG(1, 0, s, t, "CHAP user too long %d\n", l - 16);
+		LOG(1, s, t, "CHAP user too long %d\n", l - 16);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -206,7 +206,7 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		run_plugins(PLUGIN_PRE_AUTH, &packet);
 		if (!packet.continue_auth)
 		{
-			LOG(3, 0, s, t, "A plugin rejected PRE_AUTH\n");
+			LOG(3, s, t, "A plugin rejected PRE_AUTH\n");
 			if (packet.username) free(packet.username);
 			if (packet.password) free(packet.password);
 			return;
@@ -220,11 +220,11 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	}
 
 	radius[r].chap = 1;
-	LOG(3, 0, s, t, "CHAP login %s\n", session[s].user);
+	LOG(3, s, t, "CHAP login %s\n", session[s].user);
 	radiussend(r, RADIUSAUTH);
 }
 
-char *ppp_lcp_types[] = {
+static char *ppp_lcp_types[] = {
 	NULL,
 	"ConfigReq",
 	"ConfigAck",
@@ -240,14 +240,14 @@ char *ppp_lcp_types[] = {
 	"IdentRequest",
 };
 
-void dumplcp(u8 *p, int l)
+static void dumplcp(u8 *p, int l)
 {
 	int x = l - 4;
 	u8 *o = (p + 4);
 
 	LOG_HEX(5, "PPP LCP Packet", p, l);
-	LOG(4, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
-	LOG(4, 0, 0, 0, "Length: %d\n", l);
+	LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
+	LOG(4, 0, 0, "Length: %d\n", l);
 	if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck)
 		return;
 
@@ -257,12 +257,12 @@ void dumplcp(u8 *p, int l)
 		int length = o[1];
 		if (length < 2)
 		{
-			LOG(4, 0, 0, 0, "	Option length is %d...\n", length);
+			LOG(4, 0, 0, "	Option length is %d...\n", length);
 			break;
 		}
 		if (type == 0)
 		{
-			LOG(4, 0, 0, 0, "	Option type is 0...\n");
+			LOG(4, 0, 0, "	Option type is 0...\n");
 			x -= length;
 			o += length;
 			continue;
@@ -271,51 +271,51 @@ void dumplcp(u8 *p, int l)
 		{
 			case 1: // Maximum-Receive-Unit
 				if (length == 4)
-					LOG(4, 0, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+					LOG(4, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
 				else
-					LOG(4, 0, 0, 0, "    %s odd length %d\n", lcp_types[type], length);
+					LOG(4, 0, 0, "    %s odd length %d\n", lcp_types[type], length);
 				break;
 			case 2: // Async-Control-Character-Map
 				if (length == 6)
 				{
 					u32 asyncmap = ntohl(*(u32 *)(o + 2));
-					LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], asyncmap);
+					LOG(4, 0, 0, "    %s %x\n", lcp_types[type], asyncmap);
 				}
 				else
-					LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+					LOG(4, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
 				break;
 			case 3: // Authentication-Protocol
 				if (length == 4)
 				{
 					int proto = ntohs(*(u16 *)(o + 2));
-					LOG(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
+					LOG(4, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
 						proto == PPPCHAP ? "CHAP" :
 						proto == PPPPAP  ? "PAP"  : "UNKNOWN");
 				}
 				else
-					LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+					LOG(4, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
 				break;
 			case 4: // Quality-Protocol
 				{
 					u32 qp = ntohl(*(u32 *)(o + 2));
-					LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], qp);
+					LOG(4, 0, 0, "    %s %x\n", lcp_types[type], qp);
 				}
 				break;
 			case 5: // Magic-Number
 				if (length == 6)
 				{
 					u32 magicno = ntohl(*(u32 *)(o + 2));
-					LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
+					LOG(4, 0, 0, "    %s %x\n", lcp_types[type], magicno);
 				}
 				else
-					LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+					LOG(4, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
 				break;
 			case 7: // Protocol-Field-Compression
 			case 8: // Address-And-Control-Field-Compression
-				LOG(4, 0, 0, 0, "    %s\n", lcp_types[type]);
+				LOG(4, 0, 0, "    %s\n", lcp_types[type]);
 				break;
 			default:
-				LOG(2, 0, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
+				LOG(2, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
 				break;
 		}
 		x -= length;
@@ -336,14 +336,14 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	LOG_HEX(5, "LCP", p, l);
 	if (l < 4)
 	{
-		LOG(1, session[s].ip, s, t, "Short LCP %d bytes\n", l);
+		LOG(1, s, t, "Short LCP %d bytes\n", l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
 
 	if ((hl = ntohs(*(u16 *) (p + 2))) > l)
 	{
-		LOG(1, 0, s, t, "Length mismatch LCP %u/%u\n", hl, l);
+		LOG(1, s, t, "Length mismatch LCP %u/%u\n", hl, l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -351,7 +351,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 
 	if (*p == ConfigAck)
 	{
-		LOG(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
+		LOG(3, s, t, "LCP: Discarding ConfigAck\n");
 		session[s].flags |= SF_LCP_ACKED;
 	}
 	else if (*p == ConfigReq)
@@ -360,7 +360,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		u8 *o = (p + 4);
 		u8 response = 0;
 
-		LOG(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
+		LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
 		if (config->debug > 3) dumplcp(p, l);
 
 		while (x > 2)
@@ -381,17 +381,20 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 					if (response && response != ConfigNak) // rej already queued
 						break;
 
-					LOG(2, session[s].ip, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
+					LOG(2, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
 					if (!response)
 					{
-						q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-						if (!q)
-						{
-							LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
-							break;
-						}
+						q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+						if (!q) break;
 						response = *q++ = ConfigNak;
 					}
+
+					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
@@ -413,18 +416,21 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 						else
 							sprintf(proto_name, "%#4.4x", proto);
 
-						LOG(2, session[s].ip, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+						LOG(2, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
 
 						if (!response)
 						{
-							q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-							if (!q)
-							{
-								LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
-								break;
-							}
+							q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+							if (!q) break;
 							response = *q++ = ConfigNak;
 						}
+
+						if ((q - b + length) > sizeof(b))
+						{
+							LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
+							break;
+						}
+
 						memcpy(q, o, length);
 						*(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
 						q += length;
@@ -441,18 +447,20 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 					break;
 
 				default: // Reject any unknown options
-					LOG(2, session[s].ip, s, t, "    Rejecting PPP LCP Option type %d\n", type);
+					LOG(2, s, t, "    Rejecting PPP LCP Option type %d\n", type);
 					if (!response || response != ConfigRej) // drop nak in favour of rej
 					{
-						q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-						if (!q)
-						{
-							LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
-							break;
-						}
+						q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+						if (!q) return;
 						response = *q++ = ConfigRej;
 					}
 
+					if ((q - b + length) > sizeof(b))
+					{
+						LOG(2, s, t, "LCP overflow for ConfigRej (type=%d).\n", type);
+						break;
+					}
+
 					memcpy(q, o, length);
 					q += length;
 			}
@@ -464,15 +472,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		{
 			// Send back a ConfigAck
 			q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-			if (!q)
-			{
-				LOG(3, session[s].ip, s, t, " failed to create packet.\n");
-				return;
-			}
+			if (!q) return;
 			response = *q = ConfigAck;
 		}
 
-		LOG(3, session[s].ip, s, t, "Sending %s\n", ppp_lcp_types[response]);
+		LOG(3, s, t, "Sending %s\n", ppp_lcp_types[response]);
 		tunnelsend(b, l + (q - b), t);
 
 		if (!(session[s].flags & SF_LCP_ACKED))
@@ -480,22 +484,18 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	}
 	else if (*p == ConfigNak)
 	{
-		LOG(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
+		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)
-		{
-			LOG(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
-			return;
-		}
-		LOG(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n");
-		sessionshutdown(s, "Remote end closed connection.");
+		if (!q) return;
 		tunnelsend(b, l + (q - b), t); // send it
+		sessionshutdown(s, "Remote end closed connection.");
 	}
 	else if (*p == TerminateAck)
 	{
@@ -503,15 +503,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	}
 	else if (*p == EchoReq)
 	{
+		LOG(5, s, t, "LCP: Received EchoReq.  Sending EchoReply\n");
 		*p = EchoReply;		// reply
 		*(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
 		q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-		if (!q)
-		{
-			LOG(3, session[s].ip, s, t, " failed to send EchoReply.\n");
-			return;
-		}
-		LOG(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n");
+		if (!q) return;
 		tunnelsend(b, l + (q - b), t); // send it
 	}
 	else if (*p == EchoReply)
@@ -523,26 +519,42 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		*p = CodeRej;
 		if (l > MAXCONTROL)
 		{
-			LOG(1, 0, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
+			LOG(1, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
 			l = 1400;
 		}
 		q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-		if (!q)
-		{
-			LOG(3, session[s].ip, s, t, "Failed to create IdentRej.\n");
-			return;
-		}
+		if (!q) return;
 		LOG_HEX(5, "LCPIdentRej", q, l + 4);
 		tunnelsend(b, 12 + 4 + l, t);
 	}
 	else
 	{
-		LOG(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p);
+		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 u8 *findppp(u8 *b, u8 mtype)
+{
+	u16 l = ntohs(*(u16 *) (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;
+}
+
 // Process IPCP messages
 void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
@@ -553,14 +565,14 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	LOG_HEX(5, "IPCP", p, l);
 	if (l < 5)
 	{
-		LOG(1, 0, s, t, "Short IPCP %d bytes\n", l);
+		LOG(1, s, t, "Short IPCP %d bytes\n", l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
 
 	if ((hl = ntohs(*(u16 *) (p + 2))) > l)
 	{
-		LOG(1, 0, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
+		LOG(1, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -579,20 +591,24 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 		}
 		session[s].flags |= SF_IPCP_ACKED;
 
-		LOG(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+		LOG(3, s, t, "IPCP Acked, session is now active\n");
+
+		// clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers
+		session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED);
+
 		return;
 	}
 	if (*p != ConfigReq)
 	{
-		LOG(1, 0, s, t, "Unexpected IPCP code %d\n", *p);
+		LOG(1, s, t, "Unexpected IPCP code %d\n", *p);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
-	LOG(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
+	LOG(4, s, t, "IPCP ConfigReq received\n");
 
 	if (!session[s].ip)
 	{
-		LOG(3, 0, s, t, "Waiting on radius reply\n");
+		LOG(3, s, t, "Waiting on radius reply\n");
 		return;			// have to wait on RADIUS reply
 	}
 	// form a config reply quoting the IP in the session
@@ -615,29 +631,27 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 			u16 n = 4;
 			i = p + l;
 			if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
-			{
-				LOG(2, 0, s, t, "Failed to send IPCP ConfigRej\n");
 				return;
-			}
+
 			*q = ConfigRej;
 			p += 4;
 			while (p < i && p[1])
 			{
 				if (*p != 0x81 && *p != 0x83 && *p != 3)
 				{
-					LOG(2, 0, s, t, "IPCP reject %d\n", *p);
+					LOG(2, s, t, "IPCP reject %d\n", *p);
 					memcpy(q + n, p, p[1]);
 					n += p[1];
 				}
 				p += p[1];
 			}
 			*(u16 *) (q + 2) = htons(n);
-			LOG(4, session[s].ip, s, t, "Sending ConfigRej\n");
+			LOG(4, s, t, "Sending ConfigRej\n");
 			tunnelsend(b, n + (q - b), t); // send it
 		}
 		else
 		{
-			LOG(4, session[s].ip, s, t, "Sending ConfigAck\n");
+			LOG(4, s, t, "Sending ConfigAck\n");
 			*p = ConfigAck;
 			if ((i = findppp(p, 0x81))) // Primary DNS address
 			{
@@ -645,7 +659,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 				{
 					*(u32 *) (i + 2) = htonl(session[s].dns1);
 					*p = ConfigNak;
-					LOG(5, session[s].ip, s, t, "   DNS1 = %s\n", inet_toa(session[s].dns1));
+					LOG(5, s, t, "   DNS1 = %s\n", fmtaddr(session[s].dns1, 0));
 				}
 			}
 			if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it)
@@ -654,13 +668,13 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 				{
 					*(u32 *) (i + 2) = htonl(session[s].dns2);
 					*p = ConfigNak;
-					LOG(5, session[s].ip, s, t, "   DNS2 = %s\n", inet_toa(session[s].dns2));
+					LOG(5, s, t, "   DNS2 = %s\n", fmtaddr(session[s].dns2, 0));
 				}
 			}
 			i = findppp(p, 3);		// IP address
 			if (!i || i[1] != 6)
 			{
-				LOG(1, 0, s, t, "No IP in IPCP request\n");
+				LOG(1, s, t, "No IP in IPCP request\n");
 				STAT(tunnel_rx_errors);
 				return ;
 			}
@@ -668,14 +682,12 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 			{
 				*(u32 *) (i + 2) = htonl(session[s].ip);
 				*p = ConfigNak;
-				LOG(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
-						inet_toa(htonl(session[s].ip)));
+				LOG(4, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
+						fmtaddr(htonl(session[s].ip), 0));
 			}
 			if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
-			{
-				LOG(2, 0, s, t, " Failed to send IPCP packet.\n");
 				return;
-			}
+
 			tunnelsend(b, l + (q - b), t); // send it
 		}
 	}
@@ -697,7 +709,7 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 
 	if (l > MAXETHER)
 	{
-		LOG(1, ip, s, t, "IP packet too long %d\n", l);
+		LOG(1, s, t, "IP packet too long %d\n", l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -705,10 +717,14 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	// no spoof (do sessionbyip to handled statically routed subnets)
 	if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
 	{
-		LOG(5, ip, s, t, "Dropping packet with spoofed IP %s\n", inet_toa(htonl(ip)));
+		LOG(5, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0));
 		return;
 	}
 
+	// run access-list if any
+	if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
+		return;
+
 	// Add on the tun header
 	p -= 4;
 	*(u32 *)p = htonl(0x00000800);
@@ -728,7 +744,7 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 	if (tun_write(p, l) < 0)
 	{
 		STAT(tun_tx_errors);
-		LOG(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+		LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
 			l, strerror(errno), tunfd, p);
 
 		return;
@@ -762,7 +778,7 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 	if (write(tunfd, buf, len) < 0)
 	{
 		STAT(tun_tx_errors);
-		LOG(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+		LOG(0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
 			len, strerror(errno), tunfd, buf);
 
 		return;
@@ -771,7 +787,7 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 	if (session[s].snoop_ip && session[s].snoop_port)
 	{
 		// Snooping this session
-		snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
+		snoop_send_packet(buf + 4, len - 4, session[s].snoop_ip, session[s].snoop_port);
 	}
 
 	// Increment packet counters
@@ -783,48 +799,59 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 	eth_tx += len - 4;
 
 	STAT(tun_tx_packets);
-	INC_STAT(tun_tx_bytes, l - 4);
+	INC_STAT(tun_tx_bytes, len - 4);
 }
 
 
 // Process CCP messages
 void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
+	u8 b[MAXCONTROL];
+	u8 *q;
 
 	CSTAT(call_processccp);
 
 	LOG_HEX(5, "CCP", p, l);
-	if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
+	switch (l > 1 ? *p : 0)
 	{
-		LOG(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
-		STAT(tunnel_rx_errors);
-		return ;
-	}
-	// reject
-	{
-		u8 b[MAXCONTROL];
-		u8 *q;
-		if (*p == ConfigReq)
+	case ConfigAck:
+		session[s].flags |= SF_CCP_ACKED;
+		return;
+
+	case ConfigReq:
+		if (l < 6) // accept no compression
 		{
-			if (l < 6)
-			{
-				*p = ConfigAck;		// accept no compression
-			}
-			else
-			{
-				*p = ConfigRej;		// reject
-				sendccp(t, s);
-			}
+			*p = ConfigAck;
+			break;
 		}
+
+		// compression requested--reject
+		*p = ConfigRej;
+
+		// send CCP request for no compression for our end if not negotiated
+		if (!(session[s].flags & SF_CCP_ACKED))
+			initccp(t, s);
+
+		break;
+
+	case TerminateReq:
+	    	*p = TerminateAck;
+		break;
+
+	default:
+		if (l > 1)
+			LOG(1, s, t, "Unexpected CCP request code %d\n", *p);
 		else
-			*p = TerminateAck;		// close
-		if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
-		{
-			LOG(1,0,0,0, "Failed to send CCP packet.\n");	
-			return;
-		}
-		tunnelsend(b, l + (q - b), t); // send it
+			LOG(1, s, t, "Short CCP packet\n");
+
+		STAT(tunnel_rx_errors);
+		return;
 	}
+
+	if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
+		return;
+
+	tunnelsend(b, l + (q - b), t); // send it
 }
 
 // send a CHAP PP packet
@@ -838,11 +865,11 @@ void sendchap(tunnelidt t, sessionidt s)
 
 	if (!r)
 	{
-		LOG(1, 0, s, t, "No RADIUS to send challenge\n");
+		LOG(1, s, t, "No RADIUS to send challenge\n");
 		STAT(tunnel_tx_errors);
 		return ;
 	}
-	LOG(1, 0, s, t, "Send CHAP challenge\n");
+	LOG(1, s, t, "Send CHAP challenge\n");
 	{
 		// new challenge
 		int n;
@@ -862,11 +889,8 @@ void sendchap(tunnelidt t, sessionidt s)
 		return ;
 	}
 	q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
-	if (!q)
-	{
-		LOG(1, 0, s, t, "failed to send CHAP challenge.\n");
-		return;
-	}
+	if (!q) return;
+
 	*q = 1;					// challenge
 	q[1] = radius[r].id;			// ID
 	q[4] = 16;				// length
@@ -881,8 +905,13 @@ void sendchap(tunnelidt t, sessionidt s)
 // returns start of PPP frame
 u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype)
 {
-	if (size < 12)
-		return NULL;	// Need more space than this!!
+	if (size < 12) // 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;
+	}
 
 	*(u16 *) (b + 0) = htons(0x0002); // L2TP with no options
 	*(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
@@ -901,47 +930,29 @@ u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype)
 		b += 2;
 	}
 
-	if (l + 12 > size) {
-		LOG(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l);
-		return NULL;	// Run out of room to hold the packet!
+	if (l + 12 > 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)
+		return NULL;
 	}
+
 	if (p && l)
 		memcpy(b, p, l);
-	return b;
-}
 
-// find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 *b, u8 mtype)
-{
-	u16 l = ntohs(*(u16 *) (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;
+	return b;
 }
 
-// Send initial LCP ConfigReq
+// Send initial LCP ConfigReq for PAP, set magic no.
 void initlcp(tunnelidt t, sessionidt s)
 {
-	char b[500] = {0}, *q;
+	char b[500], *q;
 
-	q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
-	if (!q)
-	{
-		LOG(1, 0, s, t, "Failed to send LCP ConfigReq.\n");
+	if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
 		return;
-	}
-	LOG(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
+
+	LOG(4, s, t, "Sending LCP ConfigReq for PAP\n");
 	*q = ConfigReq;
 	*(u8 *)(q + 1) = (time_now % 255) + 1; // ID
 	*(u16 *)(q + 2) = htons(14); // Length
@@ -951,19 +962,24 @@ void initlcp(tunnelidt t, sessionidt s)
 	*(u8 *)(q + 10) = 3;
 	*(u8 *)(q + 11) = 4;
 	*(u16 *)(q + 12) = htons(PPPPAP); // PAP
-	tunnelsend(b, 12 + 14, t);
+
+	LOG_HEX(5, "PPPLCP", q, 14);
+	tunnelsend(b, (q - b) + 14, t);
 }
 
-// Send CCP reply
-void sendccp(tunnelidt t, sessionidt s)
+// Send CCP request for no compression
+static void initccp(tunnelidt t, sessionidt s)
 {
-	char *q, b[500] = {0};
+	char b[500], *q;
 
-	q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
+	if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP)))
+		return;
+
+	LOG(4, s, t, "Sending CCP ConfigReq for no compression\n");
 	*q = ConfigReq;
 	*(u8 *)(q + 1) = (time_now % 255) + 1; // ID
 	*(u16 *)(q + 2) = htons(4); // Length
+
 	LOG_HEX(5, "PPPCCP", q, 4);
 	tunnelsend(b, (q - b) + 4 , t);
 }
-