X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/29c173cadc5969d03fabac250fa9868c2481f10c..ec4de7f8c59e136f02451f4adfbe87b6d7ef36af:/ppp.c

diff --git a/ppp.c b/ppp.c
index b18840f..0a0dd45 100644
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.45 2005/03/10 03:31:25 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.62 2005/06/02 11:32:31 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -24,6 +24,7 @@ extern time_t time_now;
 extern configt *config;
 
 static void initccp(tunnelidt t, sessionidt s);
+static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype);
 
 // Process PAP messages
 void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
@@ -39,14 +40,16 @@ 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.", 3, 0);
+		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.", 3, 0);
+		return;
 	}
 	l = hl;
 
@@ -54,7 +57,8 @@ 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.", 3, 0);
+		return;
 	}
 
 	{
@@ -74,7 +78,7 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		}
 		LOG(3, s, t, "PAP login %s/%s\n", user, pass);
 	}
-	if (session[s].ip || !session[s].radius)
+	if (session[s].ip || !sess_local[s].radius)
 	{
 		// respond now, either no RADIUS available or already authenticated
 		uint8_t b[MAXCONTROL];
@@ -102,11 +106,12 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		}
 		LOG(3, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
 		tunnelsend(b, 5 + (p - b), t); // send it
+		sessionshutdown(s, "PAP authentication failed.", 3, 0);
 	}
 	else
 	{
 		// set up RADIUS request
-		uint16_t r = session[s].radius;
+		uint16_t r = sess_local[s].radius;
 
 		// Run PRE_AUTH plugins
 		struct param_pre_auth packet = { &tunnel[t], &session[s], strdup(user), strdup(pass), PPPPAP, 1 };
@@ -140,7 +145,7 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	CSTAT(processchap);
 
 	LOG_HEX(5, "CHAP", p, l);
-	r = session[s].radius;
+	r = sess_local[s].radius;
 	if (!r)
 	{
 		LOG(1, s, t, "Unexpected CHAP message\n");
@@ -152,14 +157,16 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	{
 		LOG(1, s, t, "Short CHAP %u bytes\n", l);
 		STAT(tunnel_rx_errors);
-		return ;
+		sessionshutdown(s, "Short CHAP packet.", 3, 0);
+		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.", 3, 0);
+		return;
 	}
 	l = hl;
 
@@ -167,20 +174,23 @@ 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.", 3, 0);
 		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.", 3, 0);
+		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.", 3, 0);
+		return;
 	}
 
 	l -= 5;
@@ -189,7 +199,8 @@ 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.", 3, 0);
+		return;
 	}
 
 	// Run PRE_AUTH plugins
@@ -275,8 +286,14 @@ static void dumplcp(uint8_t *p, int l)
 				{
 					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");
+						proto == PPPPAP  ? "PAP"  : "UNSUPPORTED");
+				}
+				else if (length == 5)
+				{
+					int proto = ntohs(*(uint16_t *)(o + 2));
+					int algo = *(uint8_t *)(o + 4);
+					LOG(4, 0, 0, "   %s 0x%x 0x%x (%s)\n", lcp_type(type), proto, algo,
+						(proto == PPPCHAP && algo == 5) ? "CHAP MD5"  : "UNSUPPORTED");
 				}
 				else
 					LOG(4, 0, 0, "   %s odd length %d\n", lcp_type(type), length);
@@ -337,7 +354,33 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
 	if (*p == ConfigAck)
 	{
-		LOG(3, s, t, "LCP: Discarding ConfigAck\n");
+		int x = l - 4;
+		uint8_t *o = (p + 4);
+
+		LOG(3, s, t, "LCP: ConfigAck (%d bytes)...\n", l);
+		if (config->debug > 3) dumplcp(p, l);
+
+		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 == PPPCHAP && *(o + 4) == 5)
+							sendchap(t, s);
+					}
+
+					break;
+			}
+			x -= length;
+			o += length;
+		}
+
 		session[s].flags |= SF_LCP_ACKED;
 	}
 	else if (*p == ConfigReq)
@@ -387,24 +430,35 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 					*q++ = 6;
 					memset(q, 0, 4); // asyncmap 0
 					q += 4;
-					*((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
 					break;
 
 				case 3: // Authentication-Protocol
 					{
 						int proto = ntohs(*(uint16_t *)(o + 2));
 						char proto_name[] = "0x0000";
+						uint8_t *a;
+
 						if (proto == PPPPAP)
-							break;
+						{
+							if (config->radius_authtypes & 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
+								break;
 
-						if (proto == PPPCHAP)
 							strcpy(proto_name, "CHAP");
+						}
 						else
 							sprintf(proto_name, "%#4.4x", proto);
 
+						if (response && *response != ConfigNak) // rej already queued
+							break;
+
 						LOG(2, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
 
 						if (!response)
@@ -415,16 +469,28 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 							q += 4;
 						}
 
-						if ((q - b + length) > sizeof(b))
+						a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authprefer);
+						if (!a)
 						{
 							LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
 							break;
 						}
 
-						memcpy(q, o, length);
-						*(uint16_t *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
-						q += length;
-						*((uint16_t *) (response + 2)) = htons(q - response);
+						q = a;
+
+						if (config->radius_authtypes != config->radius_authprefer)
+						{
+							a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authtypes & ~config->radius_authprefer);
+							if (!a)
+							{
+								LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
+								break;
+							}
+
+							q = a;
+						}
+
+						break;
 					}
 					break;
 
@@ -455,31 +521,97 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
 					memcpy(q, o, length);
 					q += length;
-					*((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
 			}
 			x -= length;
 			o += length;
 		}
 
-		if (!response)
+		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
+		}
+		else
+		{
+			// Send packet back as ConfigAck
+			response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+			if (!response) return;
+			*response = ConfigAck;
 		}
 
 		LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response));
-		tunnelsend(b, l + (q - b), t);
+		tunnelsend(b, l + response - b, t);
 
 		if (!(session[s].flags & SF_LCP_ACKED))
-			initlcp(t, s);
+			sendlcp(t, s, config->radius_authprefer);
 	}
 	else if (*p == ConfigNak)
 	{
-		LOG(1, s, t, "Remote end sent a ConfigNak.  Ignoring\n");
+		int x = l - 4;
+		uint8_t *o = (p + 4);
+		int authtype = -1;
+
+		LOG(3, s, t, "LCP: ConfigNak (%d bytes)...\n", l);
 		if (config->debug > 3) dumplcp(p, l);
-		return ;
+
+		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
+					session[s].mru = ntohs(*(uint16_t *)(o + 2));
+					LOG(3, s, t, "    Remote requested MRU of %u\n", session[s].mru);
+					break;
+
+				case 3: // Authentication-Protocol
+					if (authtype > 0)
+						break;
+
+					{
+						int 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 && *(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);
+						}
+					}
+
+					break;
+
+				default:
+				    	LOG(2, s, t, "    Remote NAKed LCP type %u?\n", type);
+					break;
+			}
+			x -= length;
+			o += length;
+		}
+
+		if (!authtype)
+		{
+			sessionshutdown(s, "Unsupported authentication.", 3, 0);
+			return;
+		}
+
+		if (authtype == -1)
+			authtype = config->radius_authprefer;
+
+		sendlcp(t, s, authtype);
 	}
 	else if (*p == TerminateReq)
 	{
@@ -488,11 +620,11 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 		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.");
+		sessionshutdown(s, "Remote end closed connection.", 3, 0);
 	}
 	else if (*p == TerminateAck)
 	{
-		sessionshutdown(s, "Connection closed.");
+		sessionshutdown(s, "Connection closed.", 3, 0);
 	}
 	else if (*p == ProtocolRej)
 	{
@@ -538,7 +670,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	{
 		LOG(1, s, t, "Unexpected LCP code %d\n", *p);
 		STAT(tunnel_rx_errors);
-		return ;
 	}
 }
 
@@ -588,7 +719,7 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	if (*p == ConfigAck)
 	{
 		// happy with our IPCP
-		uint16_t r = session[s].radius;
+		uint16_t r = sess_local[s].radius;
 		if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
 		{
 			if (!r)
@@ -884,21 +1015,26 @@ 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);
 }
 
 // process IPv6 packet received
@@ -972,21 +1108,26 @@ void processipv6in(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);
 }
 
 //
@@ -1006,19 +1147,24 @@ 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);
@@ -1076,11 +1222,11 @@ void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 	tunnelsend(b, l + (q - b), t); // send it
 }
 
-// send a CHAP PP packet
+// send a CHAP challenge
 void sendchap(tunnelidt t, sessionidt s)
 {
 	uint8_t b[MAXCONTROL];
-	uint16_t r = session[s].radius;
+	uint16_t r = sess_local[s].radius;
 	uint8_t *q;
 
 	CSTAT(sendchap);
@@ -1094,8 +1240,6 @@ 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)
@@ -1105,7 +1249,7 @@ 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.", 3, 0);
 		STAT(tunnel_tx_errors);
 		return ;
 	}
@@ -1114,7 +1258,7 @@ void sendchap(tunnelidt t, sessionidt s)
 
 	*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
 	*(uint16_t *) (q + 2) = htons(strlen(hostname) + 21); // length
@@ -1165,27 +1309,64 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionid
 	return b;
 }
 
-// Send initial LCP ConfigReq for PAP, set magic no.
-void initlcp(tunnelidt t, sessionidt s)
+static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype)
 {
-	char b[500], *q;
+	if ((authtype == AUTHCHAP && size < 5) || size < 4)
+		return 0;
+
+	*b++ = 3; // Authentication-Protocol
+	if (authtype == AUTHCHAP)
+	{
+		*b++ = 5; // length
+		*(uint16_t *) b = htons(PPPCHAP); b += 2;
+		*b++ = 5; // MD5
+	}
+	else if (authtype == AUTHPAP)
+	{
+		*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 b;
+}
+
+// Send initial LCP ConfigReq for MRU, authentication type and magic no
+void sendlcp(tunnelidt t, sessionidt s, int authtype)
+{
+	char b[500], *q, *l;
 
 	if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
 		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(4, s, t, "Sending LCP ConfigReq for %s\n",
+	    authtype == AUTHCHAP ? "CHAP" : "PAP");
+
+	if (!session[s].mru)
+		session[s].mru = DEFAULT_MRU;
+
+	l = q;
+	*l++ = ConfigReq;
+	*l++ = (time_now % 255) + 1; // ID
+
+	l += 2; //Save space for length
+
+	*l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
+	*(uint16_t *) l = htons(session[s].mru); l += 2;
+
+	l = add_lcp_auth(l, sizeof(b) - (l - b), authtype);
+
+	*l++ = 5; *l++ = 6; // Magic-Number (length 6)
+	*(uint32_t *) l = htonl(session[s].magic);
+	l += 4;
+
+	*(uint16_t *)(q + 2) = htons(l - q); // Length
+
+	LOG_HEX(5, "PPPLCP", q, l - q);
+	tunnelsend(b, (l - b), t);
 }
 
 // Send CCP request for no compression