* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
* The Regents of the University of California. All rights reserved.
*
+ * Copyright (c) 1999-2004 The tcpdump.org project
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
#ifndef lint
static const char rcsid[] _U_ =
- "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.111 2004-03-23 07:15:36 guy Exp $ (LBL)";
+ "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.120.2.3 2005-10-16 06:05:46 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include <tcpdump-stdinc.h>
-#include <rpc/rpc.h>
-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "ip6.h"
#endif
#include "ipproto.h"
+#include "rpc_auth.h"
+#include "rpc_msg.h"
#include "nameser.h"
#ifdef HAVE_LIBCRYPTO
#include <openssl/md5.h>
-static int tcp_verify_signature(const struct ip *ip, struct tcphdr *tp,
+#define SIGNATURE_VALID 0
+#define SIGNATURE_INVALID 1
+#define CANT_CHECK_SIGNATURE 2
+
+static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
const u_char *data, int length, const u_char *rcvsig);
#endif
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 ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
+ if (!qflag && hlen >= sizeof(*tp) && hlen <= length) {
+ if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg) <= snapend &&
dport == NFS_PORT) {
nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
(u_char *)ip);
return;
- } else if ((u_char *)tp + 4 + sizeof(struct rpc_msg)
+ } else if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg)
<= snapend &&
sport == NFS_PORT) {
nfsreply_print((u_char *)tp + hlen + 4, length - hlen,
}
}
+ 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 = EXTRACT_32BITS(&tp->th_seq);
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|
thseq = thack = threv = 0;
}
if (hlen > length) {
- (void)printf(" [bad hdr length]");
+ (void)printf(" [bad hdr length %u - too long, > %u]",
+ hlen, length);
return;
}
u_int16_t sum, tcp_sum;
if (TTEST2(tp->th_sport, length)) {
sum = tcp_cksum(ip, tp, length);
+
+ (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
if (sum != 0) {
tcp_sum = EXTRACT_16BITS(&tp->th_sum);
- (void)printf(" [bad tcp cksum %x (->%x)!]",
- tcp_sum, in_cksum_shouldbe(tcp_sum, sum));
+ (void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
} else
- (void)printf(" [tcp sum ok]");
+ (void)printf(" (correct),");
}
}
#ifdef INET6
if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) {
- int sum;
+ u_int16_t sum,tcp_sum;
if (TTEST2(tp->th_sport, length)) {
sum = tcp6_cksum(ip6, tp, length);
- if (sum != 0)
- (void)printf(" [bad tcp cksum %x!]", sum);
- else
- (void)printf(" [tcp sum ok]");
+ (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
+ if (sum != 0) {
+ tcp_sum = EXTRACT_16BITS(&tp->th_sum);
+ (void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
+ } else
+ (void)printf(" (correct),");
+
}
}
#endif
break;
case TCPOPT_SACK:
- (void)printf("sack");
datalen = len - 2;
if (datalen % 8 != 0) {
- (void)printf(" malformed sack ");
+ (void)printf("malformed sack");
} else {
u_int32_t s, e;
- (void)printf(" sack %d ", datalen / 8);
+ (void)printf("sack %d ", datalen / 8);
for (i = 0; i < datalen; i += 8) {
LENCHECK(i + 4);
s = EXTRACT_32BITS(cp + i);
}
(void)printf("{%u:%u}", s, e);
}
- (void)printf(" ");
}
break;
case TCPOPT_SIGNATURE:
(void)printf("md5:");
- if (IP_V(ip) != 4) {
- (void)printf("!ipv4");
- break;
- }
datalen = TCP_SIGLEN;
LENCHECK(datalen);
#ifdef HAVE_LIBCRYPTO
- if (tcp_verify_signature(ip, tp,
- bp + TH_OFF(tp) * 4, length, cp) == 0)
+ switch (tcp_verify_signature(ip, tp,
+ bp + TH_OFF(tp) * 4, length, cp)) {
+
+ case SIGNATURE_VALID:
(void)printf("valid");
- else
+ break;
+
+ case SIGNATURE_INVALID:
(void)printf("invalid");
+ break;
+
+ case CANT_CHECK_SIGNATURE:
+ (void)printf("can't check - ");
+ for (i = 0; i < TCP_SIGLEN; ++i)
+ (void)printf("%02x", cp[i]);
+ break;
+ }
#else
for (i = 0; i < TCP_SIGLEN; ++i)
(void)printf("%02x", cp[i]);
} else if (sport == MSDP_PORT || dport == MSDP_PORT) {
msdp_print(bp, length);
}
- else if (sport == LDP_PORT || dport == LDP_PORT)
- printf(": LDP, length: %u", length);
+ else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
+ ldp_print(bp, length);
+ }
}
return;
bad:
#ifdef HAVE_LIBCRYPTO
static int
-tcp_verify_signature(const struct ip *ip, struct tcphdr *tp,
+tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
const u_char *data, int length, const u_char *rcvsig)
{
- char sig[TCP_SIGLEN];
+ struct tcphdr tp1;
+ u_char sig[TCP_SIGLEN];
char zero_proto = 0;
MD5_CTX ctx;
- u_short savecsum, tlen;
+ u_int16_t savecsum, tlen;
+#ifdef INET6
+ struct ip6_hdr *ip6;
+#endif
+ u_int32_t len32;
+ u_int8_t nxt;
+
+ tp1 = *tp;
if (tcpmd5secret == NULL)
- return (-1);
+ return (CANT_CHECK_SIGNATURE);
MD5_Init(&ctx);
/*
* Step 1: Update MD5 hash with IP pseudo-header.
*/
- MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
- MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
- MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
- MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
- tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
- tlen = htons(tlen);
- MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
+ if (IP_V(ip) == 4) {
+ MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
+ MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
+ MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
+ MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
+ tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
+ tlen = htons(tlen);
+ MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
+#ifdef INET6
+ } else if (IP_V(ip) == 6) {
+ ip6 = (struct ip6_hdr *)ip;
+ MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
+ MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
+ len32 = htonl(ntohs(ip6->ip6_plen));
+ MD5_Update(&ctx, (char *)&len32, sizeof(len32));
+ nxt = 0;
+ MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
+ MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
+ MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
+ nxt = IPPROTO_TCP;
+ MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
+#endif
+ } else
+ return (CANT_CHECK_SIGNATURE);
+
/*
* Step 2: Update MD5 hash with TCP header, excluding options.
* The TCP checksum must be set to zero.
*/
- savecsum = tp->th_sum;
- tp->th_sum = 0;
- MD5_Update(&ctx, (char *)tp, sizeof(struct tcphdr));
- tp->th_sum = savecsum;
+ savecsum = tp1.th_sum;
+ tp1.th_sum = 0;
+ MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
+ tp1.th_sum = savecsum;
/*
* Step 3: Update MD5 hash with TCP segment data, if present.
*/
MD5_Update(&ctx, tcpmd5secret, strlen(tcpmd5secret));
MD5_Final(sig, &ctx);
- return (memcmp(rcvsig, sig, 16));
+ if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
+ return (SIGNATURE_VALID);
+ else
+ return (SIGNATURE_INVALID);
}
#endif /* HAVE_LIBCRYPTO */
projects / tcpdump / blobdiff