X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/db0ded520aee06ef21acbc519ea078e2463a4a96..66ded1b9e5e9eaf47ba84784c7212af292ab0f91:/ppp.c

diff --git a/ppp.c b/ppp.c
index c2c3379..6f5bacf 100644
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.17 2004-10-29 04:01:53 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.20 2004-11-05 02:21:55 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -26,11 +26,11 @@ extern struct configt *config;
 void sendccp(tunnelidt t, sessionidt s);
 
 // Process PAP messages
-void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 	char user[129];
 	char pass[129];
-
+	u16 hl;
 
 	CSTAT(call_processpap);
 
@@ -41,18 +41,22 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		STAT(tunnel_rx_errors);
 		return ;
 	}
-	if (*p != 1)
+
+	if ((hl = ntohs(*(u16 *) (p + 2))) > l)
 	{
-		log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
+		log(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
-	if (ntohs(*(u16 *) (p + 2)) > l)
+	l = hl;
+
+	if (*p != 1)
 	{
-		log(1, 0, s, t, "Length mismatch PAP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
+		log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
+
 	{
 		u8 *b = p;
 		b += 4;
@@ -123,11 +127,10 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 }
 
 // Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 	u16 r;
-	u16 len;
-
+	u16 hl;
 
 	CSTAT(call_processchap);
 
@@ -142,6 +145,22 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		STAT(tunnel_rx_errors);
 		return;
 	}
+
+	if (l < 4)
+	{
+		log(1, 0, 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);
+		STAT(tunnel_rx_errors);
+		return ;
+	}
+	l = hl;
+
 	if (*p != 2)
 	{
 		log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
@@ -154,22 +173,19 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		STAT(tunnel_rx_errors);
 		return ;
 	}
-	len = ntohs(*(u16 *) (p + 2));
-	if (len > l)
-	{
-		log(1, 0, s, t, "Bad CHAP length %d\n", len);
-		STAT(tunnel_rx_errors);
-		return ;
-	}
-	if (p[4] != 16)
+
+	if (l < 5 || p[4] != 16)
 	{
-		log(1, 0, s, t, "Bad CHAP response length %d\n", p[4]);
+		log(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
-	if (len - 21 >= sizeof(session[s].user))
+
+	l -= 5;
+	p += 5;
+	if (l < 16 || l - 16 >= sizeof(session[s].user))
 	{
-		log(1, 0, s, t, "CHAP user too long %d\n", len - 21);
+		log(1, 0, s, t, "CHAP user too long %d\n", l - 16);
 		STAT(tunnel_rx_errors);
 		return ;
 	}
@@ -178,10 +194,14 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 	{
 		struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 };
 
-		packet.username = calloc(len-20, 1);
-		packet.password = calloc(16, 1);
-		memcpy(packet.username, p + 21, len - 21);
-		memcpy(packet.password, p + 5, 16);
+		packet.password = calloc(17, 1);
+		memcpy(packet.password, p, 16);
+
+		p += 16;
+		l -= 16;
+
+		packet.username = calloc(l + 1, 1);
+		memcpy(packet.username, p, l);
 
 		run_plugins(PLUGIN_PRE_AUTH, &packet);
 		if (!packet.continue_auth)
@@ -222,7 +242,7 @@ char *ppp_lcp_types[] = {
 
 void dumplcp(u8 *p, int l)
 {
-	signed int x = l - 4;
+	int x = l - 4;
 	u8 *o = (p + 4);
 
 	log_hex(5, "PPP LCP Packet", p, l);
@@ -261,8 +281,8 @@ void dumplcp(u8 *p, int l)
 					{
 						int proto = ntohs(*(u16 *)(o + 2));
 						log(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
-							proto == 0xC223 ? "CHAP" :
-							proto == 0xC023 ? "PAP"  : "UNKNOWN");
+							proto == PPPCHAP ? "CHAP" :
+							proto == PPPPAP  ? "PAP"  : "UNKNOWN");
 					}
 					else
 						log(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
@@ -305,12 +325,12 @@ void dumplcp(u8 *p, int l)
 }
 
 // Process LCP messages
-void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 	u8 b[MAXCONTROL];
 	u8 *q = NULL;
-	u32  magicno = 0;
-
+	u32 magicno = 0;
+	u16 hl;
 
 	CSTAT(call_processlcp);
 
@@ -321,6 +341,15 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 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);
+		STAT(tunnel_rx_errors);
+		return ;
+	}
+	l = hl;
+
 	if (*p == ConfigAck)
 	{
 		log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
@@ -328,12 +357,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 	}
 	else if (*p == ConfigReq)
 	{
-		l =  ntohs(*(u16 *)(p + 2));
-		signed int x = l - 4;
+		int x = l - 4;
 		u8 *o = (p + 4);
 
 		log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
-		dumplcp(p, l);
+		if (config->debug > 3) dumplcp(p, l);
 
 		while (x > 2)
 		{
@@ -352,7 +380,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 				case 3: // Authentication-Protocol
 					{
 						int proto = ntohs(*(u16 *)(o + 2));
-						if (proto == 0xC223)
+						if (proto == PPPCHAP)
 						{
 							log(2, session[s].ip, s, t, "    Remote end is trying to do CHAP. Rejecting it.\n");
 
@@ -366,7 +394,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 								*q++ = ConfigNak;
 							}
 							memcpy(q, o, length);
-							*(u16 *)(q += 2) = htons(0xC023); // NAK -> Use PAP instead
+							*(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
 							q += length;
 						}
 						break;
@@ -436,7 +464,7 @@ 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");
-		dumplcp(p, l);
+		if (config->debug > 3) dumplcp(p, l);
 		return ;
 	}
 	else if (*p == TerminateReq)
@@ -497,8 +525,9 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 }
 
 // Process IPCP messages
-void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
+	u16 hl;
 
 	CSTAT(call_processipcp);
 
@@ -509,6 +538,15 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 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);
+		STAT(tunnel_rx_errors);
+		return ;
+	}
+	l = hl;
+
 	if (*p == ConfigAck)
 	{
 		// happy with our IPCP
@@ -532,12 +570,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		return ;
 	}
 	log(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
-	if (ntohs(*(u16 *) (p + 2)) > l)
-	{
-		log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
-		STAT(tunnel_rx_errors);
-		return ;
-	}
+
 	if (!session[s].ip)
 	{
 		log(3, 0, s, t, "Waiting on radius reply\n");
@@ -549,7 +582,6 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		u8 *i,
 		*q;
 
-		l = ntohs(*(u16 *) (p + 2)); // We must use length from IPCP len field
 		q = p + 4;
 		i = p + l;
 		while (q < i && q[1])
@@ -634,7 +666,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 //
 // 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, u8 * p, u16 l)
+void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 	ipt ip;
 
@@ -658,6 +690,12 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
 		return;
 	}
 
+	if (session[s].snoop_ip && session[s].snoop_port)
+	{
+		// Snooping this session
+		snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
+	}
+
 	// Add on the tun header
 	p -= 4;
 	*(u32 *)p = htonl(0x00000800);
@@ -675,11 +713,6 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
 	session[s].pin++;
 	eth_tx += l - 4;
 
-	if (session[s].snoop_ip && session[s].snoop_port)
-	{
-		// Snooping this session
-		snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
-	}
 	STAT(tun_tx_packets);
 	INC_STAT(tun_tx_bytes, l);
 
@@ -723,7 +756,7 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 
 
 // Process LCP messages
-void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 
 	CSTAT(call_processccp);
@@ -813,7 +846,7 @@ void sendchap(tunnelidt t, sessionidt s)
 // fill in a L2TP message with a PPP frame,
 // copies existing PPP message and changes magic number if seen
 // returns start of PPP frame
-u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype)
+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!!
@@ -845,7 +878,7 @@ u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtyp
 }
 
 // find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 * b, u8 mtype)
+u8 *findppp(u8 *b, u8 mtype)
 {
 	u16 l = ntohs(*(u16 *) (b + 2));
 	if (l < 4)
@@ -883,7 +916,7 @@ void initlcp(tunnelidt t, sessionidt s)
 	*(u32 *)(q + 6) = htonl(session[s].magic);
 	*(u8 *)(q + 10) = 3;
 	*(u8 *)(q + 11) = 4;
-	*(u16 *)(q + 12) = htons(0xC023); // PAP
+	*(u16 *)(q + 12) = htons(PPPPAP); // PAP
 	tunnelsend(b, 12 + 14, t);
 }