X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/c422d3ab0f6de2d38512a4566637bc47df291e74..refs/heads/tcpdump-3.8:/print-tcp.c

diff --git a/print-tcp.c b/print-tcp.c
index e423f8c3..9a965ff4 100644
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -20,8 +20,8 @@
  */
 
 #ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.103 2002-09-05 21:25:49 guy Exp $ (LBL)";
+static const char rcsid[] _U_ =
+    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.107.2.5 2004-07-28 20:11:31 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -46,6 +46,7 @@ static const char rcsid[] =
 #ifdef INET6
 #include "ip6.h"
 #endif
+#include "ipproto.h"
 
 #include "nameser.h"
 
@@ -99,7 +100,7 @@ static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
 
 static int tcp_cksum(register const struct ip *ip,
 		     register const struct tcphdr *tp,
-		     register int len)
+		     register u_int len)
 {
 	union phu {
 		struct phdr {
@@ -114,7 +115,7 @@ static int tcp_cksum(register const struct ip *ip,
 	const u_int16_t *sp;
 
 	/* pseudo-header.. */
-	phu.ph.len = htons(len);	/* XXX */
+	phu.ph.len = htons((u_int16_t)len);
 	phu.ph.mbz = 0;
 	phu.ph.proto = IPPROTO_TCP;
 	memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
@@ -130,9 +131,9 @@ static int tcp_cksum(register const struct ip *ip,
 
 #ifdef INET6
 static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
-	int len)
+	u_int len)
 {
-	int i, tlen;
+	size_t i;
 	register const u_int16_t *sp;
 	u_int32_t sum;
 	union {
@@ -146,14 +147,11 @@ static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
 		u_int16_t pa[20];
 	} phu;
 
-	tlen = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr) -
-	    ((const char *)tp - (const char*)ip6);
-
 	/* pseudo-header */
 	memset(&phu, 0, sizeof(phu));
 	phu.ph.ph_src = ip6->ip6_src;
 	phu.ph.ph_dst = ip6->ip6_dst;
-	phu.ph.ph_len = htonl(tlen);
+	phu.ph.ph_len = htonl(len);
 	phu.ph.ph_nxt = IPPROTO_TCP;
 
 	sum = 0;
@@ -162,10 +160,10 @@ static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
 
 	sp = (const u_int16_t *)tp;
 
-	for (i = 0; i < (tlen & ~1); i += 2)
+	for (i = 0; i < (len & ~1); i += 2)
 		sum += *sp++;
 
-	if (tlen & 1)
+	if (len & 1)
 		sum += htons((*(const u_int8_t *)sp) << 8);
 
 	while (sum > 0xffff)
@@ -208,17 +206,18 @@ tcp_print(register const u_char *bp, register u_int length,
 		return;
 	}
 
-	sport = ntohs(tp->th_sport);
-	dport = ntohs(tp->th_dport);
+	sport = EXTRACT_16BITS(&tp->th_sport);
+	dport = EXTRACT_16BITS(&tp->th_dport);
 
 	hlen = TH_OFF(tp) * 4;
 
 	/*
-	 * If data present and NFS port used, assume NFS.
+	 * If data present, header length valid, and NFS port used,
+	 * assume NFS.
 	 * Pass offset of data plus 4 bytes for RPC TCP msg length
 	 * to NFS print routines.
 	 */
-	if (!qflag) {
+	if (!qflag && hlen >= sizeof(*tp) && hlen <= length) {
 		if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
 		    dport == NFS_PORT) {
 			nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
@@ -259,15 +258,25 @@ tcp_print(register const u_char *bp, register u_int length,
 		}
 	}
 
+	if (hlen < sizeof(*tp)) {
+		(void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
+		    length - hlen, hlen, (unsigned long)sizeof(*tp));
+		return;
+	}
+
 	TCHECK(*tp);
 
-	seq = (u_int32_t)ntohl(tp->th_seq);
-	ack = (u_int32_t)ntohl(tp->th_ack);
-	win = ntohs(tp->th_win);
-	urp = ntohs(tp->th_urp);
+	seq = EXTRACT_32BITS(&tp->th_seq);
+	ack = EXTRACT_32BITS(&tp->th_ack);
+	win = EXTRACT_16BITS(&tp->th_win);
+	urp = EXTRACT_16BITS(&tp->th_urp);
 
 	if (qflag) {
-		(void)printf("tcp %d", length - TH_OFF(tp) * 4);
+		(void)printf("tcp %d", length - hlen);
+		if (hlen > length) {
+			(void)printf(" [bad hdr length %u - too long, > %u]",
+			    hlen, length);
+		}
 		return;
 	}
 	if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
@@ -289,6 +298,7 @@ tcp_print(register const u_char *bp, register u_int length,
 
 	if (!Sflag && (flags & TH_ACK)) {
 		register struct tcp_seq_hash *th;
+		const void *src, *dst;
 		register int rev;
 		struct tha tha;
 		/*
@@ -301,63 +311,68 @@ tcp_print(register const u_char *bp, register u_int length,
 		memset(&tha, 0, sizeof(tha));
 		rev = 0;
 		if (ip6) {
+			src = &ip6->ip6_src;
+			dst = &ip6->ip6_dst;
 			if (sport > dport)
 				rev = 1;
 			else if (sport == dport) {
-				int i;
-
-				for (i = 0; i < 4; i++) {
-					if (((u_int32_t *)(&ip6->ip6_src))[i] >
-					    ((u_int32_t *)(&ip6->ip6_dst))[i]) {
-						rev = 1;
-						break;
-					}
-				}
+				if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
+					rev = 1;
 			}
 			if (rev) {
-				tha.src = ip6->ip6_dst;
-				tha.dst = ip6->ip6_src;
+				memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
+				memcpy(&tha.dst, src, sizeof ip6->ip6_src);
 				tha.port = dport << 16 | sport;
 			} else {
-				tha.dst = ip6->ip6_dst;
-				tha.src = ip6->ip6_src;
+				memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
+				memcpy(&tha.src, src, sizeof ip6->ip6_src);
 				tha.port = sport << 16 | dport;
 			}
 		} else {
-			if (sport > dport ||
-			    (sport == dport &&
-			     ip->ip_src.s_addr > ip->ip_dst.s_addr)) {
+			src = &ip->ip_src;
+			dst = &ip->ip_dst;
+			if (sport > dport)
 				rev = 1;
+			else if (sport == dport) {
+				if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
+					rev = 1;
 			}
 			if (rev) {
-				*(struct in_addr *)&tha.src = ip->ip_dst;
-				*(struct in_addr *)&tha.dst = ip->ip_src;
+				memcpy(&tha.src, dst, sizeof ip->ip_dst);
+				memcpy(&tha.dst, src, sizeof ip->ip_src);
 				tha.port = dport << 16 | sport;
 			} else {
-				*(struct in_addr *)&tha.dst = ip->ip_dst;
-				*(struct in_addr *)&tha.src = ip->ip_src;
+				memcpy(&tha.dst, dst, sizeof ip->ip_dst);
+				memcpy(&tha.src, src, sizeof ip->ip_src);
 				tha.port = sport << 16 | dport;
 			}
 		}
 #else
-		if (sport < dport ||
-		    (sport == dport &&
-		     ip->ip_src.s_addr < ip->ip_dst.s_addr)) {
-			tha.src = ip->ip_src, tha.dst = ip->ip_dst;
-			tha.port = sport << 16 | dport;
-			rev = 0;
-		} else {
-			tha.src = ip->ip_dst, tha.dst = ip->ip_src;
-			tha.port = dport << 16 | sport;
+		rev = 0;
+		src = &ip->ip_src;
+		dst = &ip->ip_dst;
+		if (sport > dport)
 			rev = 1;
+		else if (sport == dport) {
+			if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
+				rev = 1;
+		}
+		if (rev) {
+			memcpy(&tha.src, dst, sizeof ip->ip_dst);
+			memcpy(&tha.dst, src, sizeof ip->ip_src);
+			tha.port = dport << 16 | sport;
+		} else {
+			memcpy(&tha.dst, dst, sizeof ip->ip_dst);
+			memcpy(&tha.src, src, sizeof ip->ip_src);
+			tha.port = sport << 16 | dport;
 		}
 #endif
 
 		threv = rev;
 		for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
 		     th->nxt; th = th->nxt)
-			if (!memcmp((char *)&tha, (char *)&th->addr,
-				  sizeof(th->addr)))
+			if (memcmp((char *)&tha, (char *)&th->addr,
+				  sizeof(th->addr)) == 0)
 				break;
 
 		if (!th->nxt || (flags & TH_SYN)) {
@@ -387,7 +402,8 @@ tcp_print(register const u_char *bp, register u_int length,
 		thseq = thack = threv = 0;
 	}
 	if (hlen > length) {
-		(void)printf(" [bad hdr length]");
+		(void)printf(" [bad hdr length %u - too long, > %u]",
+		    hlen, length);
 		return;
 	}
 
@@ -396,7 +412,7 @@ tcp_print(register const u_char *bp, register u_int length,
 		if (TTEST2(tp->th_sport, length)) {
 			sum = tcp_cksum(ip, tp, length);
 			if (sum != 0) {
-				tcp_sum = ntohs(tp->th_sum);
+				tcp_sum = EXTRACT_16BITS(&tp->th_sum);
 				(void)printf(" [bad tcp cksum %x (->%x)!]",
 				    tcp_sum, in_cksum_shouldbe(tcp_sum, sum));
 			} else
@@ -615,7 +631,7 @@ tcp_print(register const u_char *bp, register u_int length,
 			 * TCP DNS query has 2byte length at the head.
 			 * XXX packet could be unaligned, it can go strange
 			 */
-			ns_print(bp + 2, length - 2);
+			ns_print(bp + 2, length - 2, 0);
 		} else if (sport == MSDP_PORT || dport == MSDP_PORT) {
 			msdp_print(bp, length);
 		}