fix code-reject/protocol-reject

Changes

@@ -1,5 +1,7 @@
-* Mon Sep 12 2005 Brendan O'Dea <bod@optus.net> 2.1.6
+* Wed Sep 14 2005 Brendan O'Dea <bod@optus.net> 2.1.6
 - Any traffic on a tunnel resets lastrec, not just control messages.
+- Use a unique identifier for LCP.
+- Fix Code-Reject/Protocol-Reject.
 
 * Sat Sep 3 2005 Brendan O'Dea <bod@optus.net> 2.1.5
 - Avoid Code-Reject loop.

l2tpns.c

@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.129 2005-09-12 05:16:42 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.130 2005-09-13 14:23:07 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -2483,7 +2483,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
 			processipcp(s, t, p, l);
 		}
-		else if (prot == PPPIPV6CP)
+		else if (prot == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
 		{
 			session[s].last_packet = time_now;
 			if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
@@ -2512,13 +2512,8 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
 			processipin(s, t, p, l);
 		}
-		else if (prot == PPPIPV6)
+		else if (prot == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
 		{
-			if (!config->ipv6_prefix.s6_addr[0])
-			{
-				LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
-				return;
-			}
 			if (session[s].die)
 			{
 				LOG(4, s, t, "Session %d is closing.  Don't process PPP packets\n", s);
@@ -2534,10 +2529,40 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
 			processipv6in(s, t, p, l);
 		}
+		else if (session[s].ppp.lcp == Opened)
+		{
+			uint8_t
+			uint8_t *q;
+			int mru = session[s].mru;
+
+			if (!mru) mru = MAXMRU;
+			if (mru > size) mru = size;
+
+			l += 6;
+			if (l > mru) l = mru;
+
+			q = makeppp(buf, size, 0, 0, s, t, proto);
+			if (!q) return;
+
+			*q = CodeRej;
+			*(q + 1) = ++sess_local[s].lcp_ident;
+			*(uint16_t *)(q + 2) = l;
+			*(uint16_t *)(q + 4) = htons(proto);
+			memcpy(q + 6, p, l - 6);
+
+			if (prot == PPPIPV6CP)
+				LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+			else
+				LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", prot);
+
+			if (config->debug > 3) dumplcp(q, l);
+
+			tunnelsend(buf, l + (q - buf), t);
+		}
 		else
 		{
-			STAT(tunnel_rx_errors);
+			LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
-			LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
+				prot, ppp_state(session[s].ppp.lcp));
 		}
 	}
 }

l2tpns.h

@@ -1,5 +1,5 @@
 // L2TPNS Global Stuff
-// $Id: l2tpns.h,v 1.88 2005-09-12 05:16:42 bodea Exp $
+// $Id: l2tpns.h,v 1.89 2005-09-13 14:23:07 bodea Exp $
 
 #ifndef __L2TPNS_H__
 #define __L2TPNS_H__
@@ -31,7 +31,8 @@
 #define T_FREE		(0)		// A tunnel ID that won't ever be used. Mark session as free.
 
 #define	MAXCONTROL	1000		// max length control message we ever send...
-#define	MAXETHER	(1500+18)	// max packet we try sending to tun
+#define MAXMRU		1500		// max MRU as defined by RFC1661
+#define	MAXETHER	(MAXMRU+18)	// max packet we try sending to tun
 #define	MAXTEL		96		// telephone number
 #define MAXUSER		128		// username
 #define MAXPASS		128		// password
@@ -286,6 +287,9 @@ typedef struct
 		int nak_sent;
 	} lcp, ipcp, ipv6cp, ccp;
 
+	// identifier for Protocol-Reject, Code-Reject
+	uint8_t lcp_ident;
+
 	// authentication to use
 	int lcp_authtype;
 

l2tpns.spec

@@ -43,5 +43,5 @@ rm -rf %{buildroot}
 %attr(644,root,root) /usr/share/man/man[58]/*
 
 %changelog
-* Mon Sep 12 2005 Brendan O'Dea <bod@optus.net> 2.1.6-1
+* Wed Sep 14 2005 Brendan O'Dea <bod@optus.net> 2.1.6-1
 - 2.1.6 release, see /usr/share/doc/l2tpns-2.1.6/Changes

ppp.c

@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.79 2005-08-31 12:41:09 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.80 2005-09-13 14:23:07 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -300,7 +300,7 @@ static void dumplcp(uint8_t *p, int l)
 				else if (length == 5)
 				{
 					int proto = ntohs(*(uint16_t *)(o + 2));
-					int algo = *(uint8_t *)(o + 4);
+					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");
 				}
@@ -374,7 +374,7 @@ static void lcp_restart(sessionidt s)
 	change_state(s, ccp, Dead);
 }
 
-static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+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)
@@ -397,7 +397,7 @@ static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
 	return queued + option[1];
 }
 
-static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+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)
 {
@@ -415,13 +415,13 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
 	    	if (*nak_sent < config->ppp_max_failure) // reject queued
 			return queued;
 
-		return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+		return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
 	}
 
 	if (!*response)
 	{
 	    	if (*nak_sent >= config->ppp_max_failure)
-			return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+			return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
 
 		queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
 		if (!queued)
@@ -444,6 +444,33 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
 	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) mru = MAXMRU;
+	if (mru > size) mru = size;
+
+	l += 4;
+	if (l > mru) l = mru;
+
+	q = makeppp(buf, size, 0, 0, s, t, proto);
+	if (!q) return;
+
+	*q = CodeRej;
+	*(q + 1) = ++sess_local[s].lcp_ident;
+	*(uint16_t *)(q + 2) = 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(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
@@ -558,7 +585,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 						break;
 
 					LOG(3, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
-					q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
+					q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
 					break;
 
 				case 3: // Authentication-Protocol
@@ -596,14 +623,14 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 						alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
 						if (alen < 2) break; // paranoia
 
-						q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+						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)
 						{
 							// alternate type
 						    	alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer);
 							if (alen < 2) break;
-							q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+							q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
 						}
 
 						break;
@@ -621,7 +648,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
 				default: // Reject any unknown options
 					LOG(3, s, t, "    Rejecting unknown PPP LCP option %d\n", type);
-					q = ppp_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
+					q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
 			}
 			x -= length;
 			o += length;
@@ -868,22 +895,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 	}
 	else if (*p != CodeRej)
 	{
-		int code = *p;
+		ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
-		int mru = session[s].mru;
-		if (!mru)
-			mru = DEFAULT_MRU;
-
-		if (l > mru) l = mru;
-
-		*p = CodeRej;
-		q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
-		if (!q) return;
-
-		LOG(2, s, t, "Unexpected LCP code %s\n", ppp_code(code));
-		LOG(3, s, t, "LCP: send %s\n", ppp_code(*q));
-		if (config->debug > 3) dumplcp(q, l);
-
-		tunnelsend(b, l + (q - b), t);
 	}
 }
 
@@ -985,7 +997,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 				if (memcmp(o + 2, &addr, (sizeof addr)))
 				{
 					uint8_t *oq = q;
-					q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+					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.", 3, 0);
@@ -1001,7 +1013,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 				addr = htonl(session[s].dns1);
 				if (memcmp(o + 2, &addr, (sizeof addr)))
 				{
-					q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+					q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
 					if (!q) return;
 				}
 
@@ -1013,7 +1025,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 				addr = htonl(session[s].dns1);
 				if (memcmp(o + 2, &addr, sizeof(addr)))
 				{
-					q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+					q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
 					if (!q) return;
 				}
 
@@ -1021,7 +1033,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
 			default:
 				LOG(2, s, t, "    Rejecting PPP IPCP Option type %d\n", *o);
-				q = ppp_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
+				q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
 				if (!q) return;
 			}
 
@@ -1111,20 +1123,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 	}
 	else if (*p != CodeRej)
 	{
-		int code = *p;
+		ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
-		int mru = session[s].mru;
-		if (!mru)
-			mru = DEFAULT_MRU;
-
-		if (l > mru) l = mru;
-
-		*p = CodeRej;
-		q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
-		if (!q) return;
-
-		LOG(2, s, t, "Unexpected IPCP code %s\n", ppp_code(code));
-		LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q));
-		tunnelsend(b, l + (q - b), t);
 	}
 }
 
@@ -1173,16 +1172,6 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
 	LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
 
-	if (!config->ipv6_prefix.s6_addr[0])
-	{
-	    	LOG(2, s, t, "IPV6CP: %s rejected (not configured)\n", ppp_code(*p));
-		*p = ProtocolRej;
-		q = makeppp(b, sizeof(b),  p, l, s, t, PPPIPV6CP);
-		if (!q) return;
-		tunnelsend(b, l + (q - b), t);
-		return;
-	}
-
 	if (!session[s].ip)
 	{
 		LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp));
@@ -1234,7 +1223,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
 				if (memcmp(o + 2, ident, sizeof(ident)))
 				{
-					q = ppp_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
+					q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
 					if (!q) return;
 				}
 
@@ -1242,7 +1231,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
 			default:
 				LOG(2, s, t, "    Rejecting PPP IPV6CP Option type %d\n", *o);
-				q = ppp_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
+				q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
 				if (!q) return;
 			}
 
@@ -1332,20 +1321,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 	}
 	else if (*p != CodeRej)
 	{
-		int code = *p;
+		ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
-		int mru = session[s].mru;
-		if (!mru)
-			mru = DEFAULT_MRU;
-
-		if (l > mru) l = mru;
-
-		*p = CodeRej;
-		q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
-		if (!q) return;
-
-		LOG(2, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code));
-		LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
-		tunnelsend(b, l + (q - b), t);
 	}
 }
 
@@ -1693,20 +1669,7 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 	}
 	else if (*p != CodeRej)
 	{
-		int code = *p;
+		ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b));
-		int mru = session[s].mru;
-		if (!mru)
-			mru = DEFAULT_MRU;
-
-		if (l > mru) l = mru;
-
-		*p = CodeRej;
-		q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP);
-		if (!q) return;
-
-		LOG(2, s, t, "Unexpected CCP code %s\n", ppp_code(code));
-		LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
-		tunnelsend(b, l + (q - b), t);
 	}
 }
 
@@ -1840,7 +1803,7 @@ void sendlcp(sessionidt s, tunnelidt t)
 
 	l = q;
 	*l++ = ConfigReq;
-	*l++ = (time_now % 255) + 1; // ID
+	*l++ = ++sess_local[s].lcp_ident; // ID
 
 	l += 2; //Save space for length
 
@@ -1876,7 +1839,7 @@ void sendccp(sessionidt s, tunnelidt t)
 	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);