+/* $NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $ */
+
/*
* 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 1.112 2004-04-05 00:12:54 mcr Exp $ (LBL)";
+#else
+__RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");
#endif
+#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#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>
+#include <signature.h>
-static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
- const u_char *data, int length, const u_char *rcvsig);
+static int tcp_verify_signature(netdissect_options *ndo,
+ const struct ip *ip, const struct tcphdr *tp,
+ const u_char *data, int length, const u_char *rcvsig);
#endif
-static void print_tcp_rst_data(register const u_char *sp, u_int length);
+static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length);
#define MAX_RST_DATA_LEN 30
struct tha {
-#ifndef INET6
- struct in_addr src;
- struct in_addr dst;
-#else
- struct in6_addr src;
- struct in6_addr dst;
-#endif /*INET6*/
- u_int port;
+ struct in_addr src;
+ struct in_addr dst;
+ u_int port;
};
struct tcp_seq_hash {
- struct tcp_seq_hash *nxt;
- struct tha addr;
- tcp_seq seq;
- tcp_seq ack;
+ struct tcp_seq_hash *nxt;
+ struct tha addr;
+ tcp_seq seq;
+ tcp_seq ack;
+};
+
+#ifdef INET6
+struct tha6 {
+ struct in6_addr src;
+ struct in6_addr dst;
+ u_int port;
+};
+
+struct tcp_seq_hash6 {
+ struct tcp_seq_hash6 *nxt;
+ struct tha6 addr;
+ tcp_seq seq;
+ tcp_seq ack;
};
+#endif
#define TSEQ_HASHSIZE 919
/* These tcp optinos do not have the size octet */
#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
-static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
-
-
-#ifndef TELNET_PORT
-#define TELNET_PORT 23
-#endif
-#ifndef BGP_PORT
-#define BGP_PORT 179
-#endif
-#define NETBIOS_SSN_PORT 139
-#ifndef PPTP_PORT
-#define PPTP_PORT 1723
-#endif
-#define BEEP_PORT 10288
-#ifndef NFS_PORT
-#define NFS_PORT 2049
+static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
+#ifdef INET6
+static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
#endif
-#define MSDP_PORT 639
-#define LDP_PORT 646
-static int tcp_cksum(register const struct ip *ip,
- register const struct tcphdr *tp,
- register u_int len)
-{
- union phu {
- struct phdr {
- u_int32_t src;
- u_int32_t dst;
- u_char mbz;
- u_char proto;
- u_int16_t len;
- } ph;
- u_int16_t pa[6];
- } phu;
- const u_int16_t *sp;
-
- /* pseudo-header.. */
- 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));
- if (IP_HL(ip) == 5)
- memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
- else
- phu.ph.dst = ip_finddst(ip);
-
- sp = &phu.pa[0];
- return in_cksum((u_short *)tp, len,
- sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
-}
+static const struct tok tcp_flag_values[] = {
+ { TH_FIN, "F" },
+ { TH_SYN, "S" },
+ { TH_RST, "R" },
+ { TH_PUSH, "P" },
+ { TH_ACK, "." },
+ { TH_URG, "U" },
+ { TH_ECNECHO, "E" },
+ { TH_CWR, "W" },
+ { 0, NULL }
+};
-#ifdef INET6
-static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
- u_int len)
+static const struct tok tcp_option_values[] = {
+ { TCPOPT_EOL, "eol" },
+ { TCPOPT_NOP, "nop" },
+ { TCPOPT_MAXSEG, "mss" },
+ { TCPOPT_WSCALE, "wscale" },
+ { TCPOPT_SACKOK, "sackOK" },
+ { TCPOPT_SACK, "sack" },
+ { TCPOPT_ECHO, "echo" },
+ { TCPOPT_ECHOREPLY, "echoreply" },
+ { TCPOPT_TIMESTAMP, "TS" },
+ { TCPOPT_CC, "cc" },
+ { TCPOPT_CCNEW, "ccnew" },
+ { TCPOPT_CCECHO, "" },
+ { TCPOPT_SIGNATURE, "md5" },
+ { TCPOPT_AUTH, "enhanced auth" },
+ { TCPOPT_UTO, "uto" },
+ { TCPOPT_MPTCP, "mptcp" },
+ { TCPOPT_EXPERIMENT2, "exp" },
+ { 0, NULL }
+};
+
+static int
+tcp_cksum(netdissect_options *ndo,
+ register const struct ip *ip,
+ register const struct tcphdr *tp,
+ register u_int len)
{
- size_t i;
- register const u_int16_t *sp;
- u_int32_t sum;
- union {
- struct {
- struct in6_addr ph_src;
- struct in6_addr ph_dst;
- u_int32_t ph_len;
- u_int8_t ph_zero[3];
- u_int8_t ph_nxt;
- } ph;
- u_int16_t pa[20];
- } phu;
-
- /* 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(len);
- phu.ph.ph_nxt = IPPROTO_TCP;
-
- sum = 0;
- for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
- sum += phu.pa[i];
-
- sp = (const u_int16_t *)tp;
-
- for (i = 0; i < (len & ~1); i += 2)
- sum += *sp++;
-
- if (len & 1)
- sum += htons((*(const u_int8_t *)sp) << 8);
-
- while (sum > 0xffff)
- sum = (sum & 0xffff) + (sum >> 16);
- sum = ~sum & 0xffff;
-
- return (sum);
+ return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len,
+ IPPROTO_TCP);
}
-#endif
void
-tcp_print(register const u_char *bp, register u_int length,
- register const u_char *bp2, int fragmented)
+tcp_print(netdissect_options *ndo,
+ register const u_char *bp, register u_int length,
+ register const u_char *bp2, int fragmented)
{
- register const struct tcphdr *tp;
- register const struct ip *ip;
- register u_char flags;
- register u_int hlen;
- register char ch;
- u_int16_t sport, dport, win, urp;
- u_int32_t seq, ack, thseq, thack;
- int threv;
+ register const struct tcphdr *tp;
+ register const struct ip *ip;
+ register u_char flags;
+ register u_int hlen;
+ register char ch;
+ uint16_t sport, dport, win, urp;
+ uint32_t seq, ack, thseq, thack;
+ u_int utoval;
+ uint16_t magic;
+ register int rev;
#ifdef INET6
- register const struct ip6_hdr *ip6;
+ register const struct ip6_hdr *ip6;
#endif
- tp = (struct tcphdr *)bp;
- ip = (struct ip *)bp2;
-#ifdef INET6
- if (IP_V(ip) == 6)
- ip6 = (struct ip6_hdr *)bp2;
- else
- ip6 = NULL;
-#endif /*INET6*/
- ch = '\0';
- if (!TTEST(tp->th_dport)) {
- (void)printf("%s > %s: [|tcp]",
- ipaddr_string(&ip->ip_src),
- ipaddr_string(&ip->ip_dst));
- return;
- }
-
- 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.
- * 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 &&
- 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)
- <= snapend &&
- sport == NFS_PORT) {
- nfsreply_print((u_char *)tp + hlen + 4, length - hlen,
- (u_char *)ip);
- return;
- }
- }
+ tp = (struct tcphdr *)bp;
+ ip = (struct ip *)bp2;
#ifdef INET6
- if (ip6) {
- if (ip6->ip6_nxt == IPPROTO_TCP) {
- (void)printf("%s.%s > %s.%s: ",
- ip6addr_string(&ip6->ip6_src),
- tcpport_string(sport),
- ip6addr_string(&ip6->ip6_dst),
- tcpport_string(dport));
- } else {
- (void)printf("%s > %s: ",
- tcpport_string(sport), tcpport_string(dport));
- }
- } else
+ if (IP_V(ip) == 6)
+ ip6 = (struct ip6_hdr *)bp2;
+ else
+ ip6 = NULL;
#endif /*INET6*/
- {
- if (ip->ip_p == IPPROTO_TCP) {
- (void)printf("%s.%s > %s.%s: ",
- ipaddr_string(&ip->ip_src),
- tcpport_string(sport),
- ipaddr_string(&ip->ip_dst),
- tcpport_string(dport));
- } else {
- (void)printf("%s > %s: ",
- tcpport_string(sport), tcpport_string(dport));
- }
- }
+ ch = '\0';
+ if (!ND_TTEST(tp->th_dport)) {
+ ND_PRINT((ndo, "%s > %s: [|tcp]",
+ ipaddr_string(ndo, &ip->ip_src),
+ ipaddr_string(ndo, &ip->ip_dst)));
+ return;
+ }
- TCHECK(*tp);
+ sport = EXTRACT_16BITS(&tp->th_sport);
+ dport = EXTRACT_16BITS(&tp->th_dport);
- seq = EXTRACT_32BITS(&tp->th_seq);
- ack = EXTRACT_32BITS(&tp->th_ack);
- win = EXTRACT_16BITS(&tp->th_win);
- urp = EXTRACT_16BITS(&tp->th_urp);
+ hlen = TH_OFF(tp) * 4;
- if (qflag) {
- (void)printf("tcp %d", length - TH_OFF(tp) * 4);
- return;
- }
- if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
- TH_ECNECHO|TH_CWR)) {
- if (flags & TH_SYN)
- putchar('S');
- if (flags & TH_FIN)
- putchar('F');
- if (flags & TH_RST)
- putchar('R');
- if (flags & TH_PUSH)
- putchar('P');
- if (flags & TH_CWR)
- putchar('W'); /* congestion _W_indow reduced (ECN) */
- if (flags & TH_ECNECHO)
- putchar('E'); /* ecn _E_cho sent (ECN) */
- } else
- putchar('.');
-
- if (!Sflag && (flags & TH_ACK)) {
- register struct tcp_seq_hash *th;
- const void *src, *dst;
- register int rev;
- struct tha tha;
- /*
- * Find (or record) the initial sequence numbers for
- * this conversation. (we pick an arbitrary
- * collating order so there's only one entry for
- * both directions).
- */
#ifdef INET6
- 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) {
- if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
- rev = 1;
- }
- if (rev) {
- memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
- memcpy(&tha.dst, src, sizeof ip6->ip6_src);
- tha.port = dport << 16 | sport;
- } else {
- memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
- memcpy(&tha.src, src, sizeof ip6->ip6_src);
- tha.port = sport << 16 | dport;
- }
- } else {
- 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;
- }
- }
-#else
- 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)) == 0)
- break;
-
- if (!th->nxt || (flags & TH_SYN)) {
- /* didn't find it or new conversation */
- if (th->nxt == NULL) {
- th->nxt = (struct tcp_seq_hash *)
- calloc(1, sizeof(*th));
- if (th->nxt == NULL)
- error("tcp_print: calloc");
- }
- th->addr = tha;
- if (rev)
- th->ack = seq, th->seq = ack - 1;
- else
- th->seq = seq, th->ack = ack - 1;
- } else {
- if (rev)
- seq -= th->ack, ack -= th->seq;
- else
- seq -= th->seq, ack -= th->ack;
- }
-
- thseq = th->seq;
- thack = th->ack;
- } else {
- /*fool gcc*/
- thseq = thack = threv = 0;
- }
- if (hlen > length) {
- (void)printf(" [bad hdr length]");
- return;
- }
-
- if (IP_V(ip) == 4 && vflag && !fragmented) {
- u_int16_t sum, tcp_sum;
- if (TTEST2(tp->th_sport, length)) {
- sum = tcp_cksum(ip, tp, length);
- 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));
- } else
- (void)printf(" [tcp sum ok]");
- }
- }
+ if (ip6) {
+ if (ip6->ip6_nxt == IPPROTO_TCP) {
+ ND_PRINT((ndo, "%s.%s > %s.%s: ",
+ ip6addr_string(ndo, &ip6->ip6_src),
+ tcpport_string(sport),
+ ip6addr_string(ndo, &ip6->ip6_dst),
+ tcpport_string(dport)));
+ } else {
+ ND_PRINT((ndo, "%s > %s: ",
+ tcpport_string(sport), tcpport_string(dport)));
+ }
+ } else
+#endif /*INET6*/
+ {
+ if (ip->ip_p == IPPROTO_TCP) {
+ ND_PRINT((ndo, "%s.%s > %s.%s: ",
+ ipaddr_string(ndo, &ip->ip_src),
+ tcpport_string(sport),
+ ipaddr_string(ndo, &ip->ip_dst),
+ tcpport_string(dport)));
+ } else {
+ ND_PRINT((ndo, "%s > %s: ",
+ tcpport_string(sport), tcpport_string(dport)));
+ }
+ }
+
+ if (hlen < sizeof(*tp)) {
+ ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]",
+ length - hlen, hlen, (unsigned long)sizeof(*tp)));
+ return;
+ }
+
+ ND_TCHECK(*tp);
+
+ 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 (ndo->ndo_qflag) {
+ ND_PRINT((ndo, "tcp %d", length - hlen));
+ if (hlen > length) {
+ ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
+ hlen, length));
+ }
+ return;
+ }
+
+ flags = tp->th_flags;
+ ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)));
+
+ if (!ndo->ndo_Sflag && (flags & TH_ACK)) {
+ /*
+ * Find (or record) the initial sequence numbers for
+ * this conversation. (we pick an arbitrary
+ * collating order so there's only one entry for
+ * both directions).
+ */
+ rev = 0;
#ifdef INET6
- if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) {
- int 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]");
- }
- }
+ if (ip6) {
+ register struct tcp_seq_hash6 *th;
+ struct tcp_seq_hash6 *tcp_seq_hash;
+ const struct in6_addr *src, *dst;
+ struct tha6 tha;
+
+ tcp_seq_hash = tcp_seq_hash6;
+ src = &ip6->ip6_src;
+ dst = &ip6->ip6_dst;
+ if (sport > dport)
+ rev = 1;
+ else if (sport == dport) {
+ if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0)
+ rev = 1;
+ }
+ if (rev) {
+ UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst);
+ UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src);
+ tha.port = dport << 16 | sport;
+ } else {
+ UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst);
+ UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src);
+ tha.port = sport << 16 | dport;
+ }
+
+ for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
+ th->nxt; th = th->nxt)
+ if (memcmp((char *)&tha, (char *)&th->addr,
+ sizeof(th->addr)) == 0)
+ break;
+
+ if (!th->nxt || (flags & TH_SYN)) {
+ /* didn't find it or new conversation */
+ if (th->nxt == NULL) {
+ th->nxt = (struct tcp_seq_hash6 *)
+ calloc(1, sizeof(*th));
+ if (th->nxt == NULL)
+ error("tcp_print: calloc");
+ }
+ th->addr = tha;
+ if (rev)
+ th->ack = seq, th->seq = ack - 1;
+ else
+ th->seq = seq, th->ack = ack - 1;
+ } else {
+ if (rev)
+ seq -= th->ack, ack -= th->seq;
+ else
+ seq -= th->seq, ack -= th->ack;
+ }
+
+ thseq = th->seq;
+ thack = th->ack;
+ } else {
+#else /*INET6*/
+ {
+#endif /*INET6*/
+ register struct tcp_seq_hash *th;
+ struct tcp_seq_hash *tcp_seq_hash;
+ const struct in_addr *src, *dst;
+ struct tha tha;
+
+ tcp_seq_hash = tcp_seq_hash4;
+ src = &ip->ip_src;
+ dst = &ip->ip_dst;
+ if (sport > dport)
+ rev = 1;
+ else if (sport == dport) {
+ if (UNALIGNED_MEMCMP(src, dst, sizeof ip->ip_dst) > 0)
+ rev = 1;
+ }
+ if (rev) {
+ UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip->ip_dst);
+ UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip->ip_src);
+ tha.port = dport << 16 | sport;
+ } else {
+ UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip->ip_dst);
+ UNALIGNED_MEMCPY(&tha.src, src, sizeof ip->ip_src);
+ tha.port = sport << 16 | dport;
+ }
+
+ for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
+ th->nxt; th = th->nxt)
+ if (memcmp((char *)&tha, (char *)&th->addr,
+ sizeof(th->addr)) == 0)
+ break;
+
+ if (!th->nxt || (flags & TH_SYN)) {
+ /* didn't find it or new conversation */
+ if (th->nxt == NULL) {
+ th->nxt = (struct tcp_seq_hash *)
+ calloc(1, sizeof(*th));
+ if (th->nxt == NULL)
+ error("tcp_print: calloc");
+ }
+ th->addr = tha;
+ if (rev)
+ th->ack = seq, th->seq = ack - 1;
+ else
+ th->seq = seq, th->ack = ack - 1;
+ } else {
+ if (rev)
+ seq -= th->ack, ack -= th->seq;
+ else
+ seq -= th->seq, ack -= th->ack;
+ }
+
+ thseq = th->seq;
+ thack = th->ack;
+ }
+ } else {
+ /*fool gcc*/
+ thseq = thack = rev = 0;
+ }
+ if (hlen > length) {
+ ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
+ hlen, length));
+ return;
+ }
+
+ if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {
+ /* Check the checksum, if possible. */
+ uint16_t sum, tcp_sum;
+
+ if (IP_V(ip) == 4) {
+ if (ND_TTEST2(tp->th_sport, length)) {
+ sum = tcp_cksum(ndo, ip, tp, length);
+ tcp_sum = EXTRACT_16BITS(&tp->th_sum);
+
+ ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
+ if (sum != 0)
+ ND_PRINT((ndo, " (incorrect -> 0x%04x)",
+ in_cksum_shouldbe(tcp_sum, sum)));
+ else
+ ND_PRINT((ndo, " (correct)"));
+ }
+ }
+#ifdef INET6
+ else if (IP_V(ip) == 6 && ip6->ip6_plen) {
+ if (ND_TTEST2(tp->th_sport, length)) {
+ sum = nextproto6_cksum(ip6, (const uint8_t *)tp,
+ length, length, IPPROTO_TCP);
+ tcp_sum = EXTRACT_16BITS(&tp->th_sum);
+
+ ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
+ if (sum != 0)
+ ND_PRINT((ndo, " (incorrect -> 0x%04x)",
+ in_cksum_shouldbe(tcp_sum, sum)));
+ else
+ ND_PRINT((ndo, " (correct)"));
+
+ }
+ }
#endif
-
- length -= hlen;
- if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
- (void)printf(" %u:%u(%u)", seq, seq + length, length);
- if (flags & TH_ACK)
- (void)printf(" ack %u", ack);
-
- (void)printf(" win %d", win);
-
- if (flags & TH_URG)
- (void)printf(" urg %d", urp);
- /*
- * Handle any options.
- */
- if (hlen > sizeof(*tp)) {
- register const u_char *cp;
- register u_int i, opt, datalen;
- register u_int len;
-
- hlen -= sizeof(*tp);
- cp = (const u_char *)tp + sizeof(*tp);
- putchar(' ');
- ch = '<';
- while (hlen > 0) {
- putchar(ch);
- TCHECK(*cp);
- opt = *cp++;
- if (ZEROLENOPT(opt))
- len = 1;
- else {
- TCHECK(*cp);
- len = *cp++; /* total including type, len */
- if (len < 2 || len > hlen)
- goto bad;
- --hlen; /* account for length byte */
- }
- --hlen; /* account for type byte */
- datalen = 0;
+ }
+
+ length -= hlen;
+ if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
+ ND_PRINT((ndo, ", seq %u", seq));
+
+ if (length > 0) {
+ ND_PRINT((ndo, ":%u", seq + length));
+ }
+ }
+
+ if (flags & TH_ACK) {
+ ND_PRINT((ndo, ", ack %u", ack));
+ }
+
+ ND_PRINT((ndo, ", win %d", win));
+
+ if (flags & TH_URG)
+ ND_PRINT((ndo, ", urg %d", urp));
+ /*
+ * Handle any options.
+ */
+ if (hlen > sizeof(*tp)) {
+ register const u_char *cp;
+ register u_int i, opt, datalen;
+ register u_int len;
+
+ hlen -= sizeof(*tp);
+ cp = (const u_char *)tp + sizeof(*tp);
+ ND_PRINT((ndo, ", options ["));
+ while (hlen > 0) {
+ if (ch != '\0')
+ ND_PRINT((ndo, "%c", ch));
+ ND_TCHECK(*cp);
+ opt = *cp++;
+ if (ZEROLENOPT(opt))
+ len = 1;
+ else {
+ ND_TCHECK(*cp);
+ len = *cp++; /* total including type, len */
+ if (len < 2 || len > hlen)
+ goto bad;
+ --hlen; /* account for length byte */
+ }
+ --hlen; /* account for type byte */
+ datalen = 0;
/* Bail if "l" bytes of data are not left or were not captured */
-#define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
-
- switch (opt) {
-
- case TCPOPT_MAXSEG:
- (void)printf("mss");
- datalen = 2;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_16BITS(cp));
-
- break;
-
- case TCPOPT_EOL:
- (void)printf("eol");
- break;
-
- case TCPOPT_NOP:
- (void)printf("nop");
- break;
-
- case TCPOPT_WSCALE:
- (void)printf("wscale");
- datalen = 1;
- LENCHECK(datalen);
- (void)printf(" %u", *cp);
- break;
-
- case TCPOPT_SACKOK:
- (void)printf("sackOK");
- break;
-
- case TCPOPT_SACK:
- (void)printf("sack");
- datalen = len - 2;
- if (datalen % 8 != 0) {
- (void)printf(" malformed sack ");
- } else {
- u_int32_t s, e;
-
- (void)printf(" sack %d ", datalen / 8);
- for (i = 0; i < datalen; i += 8) {
- LENCHECK(i + 4);
- s = EXTRACT_32BITS(cp + i);
- LENCHECK(i + 8);
- e = EXTRACT_32BITS(cp + i + 4);
- if (threv) {
- s -= thseq;
- e -= thseq;
- } else {
- s -= thack;
- e -= thack;
- }
- (void)printf("{%u:%u}", s, e);
- }
- (void)printf(" ");
- }
- break;
-
- case TCPOPT_ECHO:
- (void)printf("echo");
- datalen = 4;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- break;
-
- case TCPOPT_ECHOREPLY:
- (void)printf("echoreply");
- datalen = 4;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- break;
-
- case TCPOPT_TIMESTAMP:
- (void)printf("timestamp");
- datalen = 8;
- LENCHECK(4);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp + 4));
- break;
-
- case TCPOPT_CC:
- (void)printf("cc");
- datalen = 4;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- break;
-
- case TCPOPT_CCNEW:
- (void)printf("ccnew");
- datalen = 4;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- break;
-
- case TCPOPT_CCECHO:
- (void)printf("ccecho");
- datalen = 4;
- LENCHECK(datalen);
- (void)printf(" %u", EXTRACT_32BITS(cp));
- break;
-
- case TCPOPT_SIGNATURE:
- (void)printf("md5:");
- if (IP_V(ip) != 4) {
- (void)printf("!ipv4");
- break;
- }
- datalen = TCP_SIGLEN;
- LENCHECK(datalen);
+#define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); }
+
+
+ ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt)));
+
+ switch (opt) {
+
+ case TCPOPT_MAXSEG:
+ datalen = 2;
+ LENCHECK(datalen);
+ ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp)));
+ break;
+
+ case TCPOPT_WSCALE:
+ datalen = 1;
+ LENCHECK(datalen);
+ ND_PRINT((ndo, " %u", *cp));
+ break;
+
+ case TCPOPT_SACK:
+ datalen = len - 2;
+ if (datalen % 8 != 0) {
+ ND_PRINT((ndo, "malformed sack"));
+ } else {
+ uint32_t s, e;
+
+ ND_PRINT((ndo, " %d ", datalen / 8));
+ for (i = 0; i < datalen; i += 8) {
+ LENCHECK(i + 4);
+ s = EXTRACT_32BITS(cp + i);
+ LENCHECK(i + 8);
+ e = EXTRACT_32BITS(cp + i + 4);
+ if (rev) {
+ s -= thseq;
+ e -= thseq;
+ } else {
+ s -= thack;
+ e -= thack;
+ }
+ ND_PRINT((ndo, "{%u:%u}", s, e));
+ }
+ }
+ break;
+
+ case TCPOPT_CC:
+ case TCPOPT_CCNEW:
+ case TCPOPT_CCECHO:
+ case TCPOPT_ECHO:
+ case TCPOPT_ECHOREPLY:
+
+ /*
+ * those options share their semantics.
+ * fall through
+ */
+ datalen = 4;
+ LENCHECK(datalen);
+ ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+ break;
+
+ case TCPOPT_TIMESTAMP:
+ datalen = 8;
+ LENCHECK(datalen);
+ ND_PRINT((ndo, " val %u ecr %u",
+ EXTRACT_32BITS(cp),
+ EXTRACT_32BITS(cp + 4)));
+ break;
+
+ case TCPOPT_SIGNATURE:
+ datalen = TCP_SIGLEN;
+ LENCHECK(datalen);
#ifdef HAVE_LIBCRYPTO
- if (tcp_verify_signature(ip, tp,
- bp + TH_OFF(tp) * 4, length, cp) == 0)
- (void)printf("valid");
- else
- (void)printf("invalid");
+ switch (tcp_verify_signature(ndo, ip, tp,
+ bp + TH_OFF(tp) * 4, length, cp)) {
+
+ case SIGNATURE_VALID:
+ ND_PRINT((ndo, "valid"));
+ break;
+
+ case SIGNATURE_INVALID:
+ ND_PRINT((ndo, "invalid"));
+ break;
+
+ case CANT_CHECK_SIGNATURE:
+ ND_PRINT((ndo, "can't check - "));
+ for (i = 0; i < TCP_SIGLEN; ++i)
+ ND_PRINT((ndo, "%02x", cp[i]));
+ break;
+ }
#else
- for (i = 0; i < TCP_SIGLEN; ++i)
- (void)printf("%02x", cp[i]);
+ for (i = 0; i < TCP_SIGLEN; ++i)
+ ND_PRINT((ndo, "%02x", cp[i]));
#endif
- break;
-
- default:
- (void)printf("opt-%u:", opt);
- datalen = len - 2;
- for (i = 0; i < datalen; ++i) {
- LENCHECK(i);
- (void)printf("%02x", cp[i]);
- }
- break;
- }
-
- /* Account for data printed */
- cp += datalen;
- hlen -= datalen;
-
- /* Check specification against observed length */
- ++datalen; /* option octet */
- if (!ZEROLENOPT(opt))
- ++datalen; /* size octet */
- if (datalen != len)
- (void)printf("[len %d]", len);
- ch = ',';
- if (opt == TCPOPT_EOL)
- break;
- }
- putchar('>');
- }
-
- if (length <= 0)
- return;
-
- /*
- * Decode payload if necessary.
- */
- bp += TH_OFF(tp) * 4;
- if (flags & TH_RST) {
- if (vflag)
- print_tcp_rst_data(bp, length);
- } else {
- if (sport == TELNET_PORT || dport == TELNET_PORT) {
- if (!qflag && vflag)
- telnet_print(bp, length);
- } else if (sport == BGP_PORT || dport == BGP_PORT)
- bgp_print(bp, length);
- else if (sport == PPTP_PORT || dport == PPTP_PORT)
- pptp_print(bp);
+ break;
+
+ case TCPOPT_AUTH:
+ ND_PRINT((ndo, "keyid %d", *cp++));
+ datalen = len - 3;
+ for (i = 0; i < datalen; ++i) {
+ LENCHECK(i);
+ ND_PRINT((ndo, "%02x", cp[i]));
+ }
+ break;
+
+
+ case TCPOPT_EOL:
+ case TCPOPT_NOP:
+ case TCPOPT_SACKOK:
+ /*
+ * Nothing interesting.
+ * fall through
+ */
+ break;
+
+ case TCPOPT_UTO:
+ datalen = 2;
+ LENCHECK(datalen);
+ utoval = EXTRACT_16BITS(cp);
+ ND_PRINT((ndo, "0x%x", utoval));
+ if (utoval & 0x0001)
+ utoval = (utoval >> 1) * 60;
+ else
+ utoval >>= 1;
+ ND_PRINT((ndo, " %u", utoval));
+ break;
+
+ case TCPOPT_MPTCP:
+ datalen = len - 2;
+ LENCHECK(datalen);
+ if (!mptcp_print(ndo, cp-2, len, flags))
+ goto bad;
+ break;
+
+ case TCPOPT_EXPERIMENT2:
+ datalen = len - 2;
+ LENCHECK(datalen);
+ if (datalen < 2)
+ goto bad;
+ /* RFC6994 */
+ magic = EXTRACT_16BITS(cp);
+ ND_PRINT((ndo, "-"));
+
+ switch(magic) {
+
+ case 0xf989:
+ /* TCP Fast Open: draft-ietf-tcpm-fastopen-04 */
+ if (datalen == 2) {
+ /* Fast Open Cookie Request */
+ ND_PRINT((ndo, "tfo cookiereq"));
+ } else {
+ /* Fast Open Cookie */
+ if (datalen % 2 != 0 || datalen < 6 || datalen > 18) {
+ ND_PRINT((ndo, "tfo malformed"));
+ } else {
+ ND_PRINT((ndo, "tfo cookie "));
+ for (i = 2; i < datalen; ++i)
+ ND_PRINT((ndo, "%02x", cp[i]));
+ }
+ }
+ break;
+
+ default:
+ /* Unknown magic number */
+ ND_PRINT((ndo, "%04x", magic));
+ break;
+ }
+ break;
+
+ default:
+ datalen = len - 2;
+ if (datalen)
+ ND_PRINT((ndo, " 0x"));
+ for (i = 0; i < datalen; ++i) {
+ LENCHECK(i);
+ ND_PRINT((ndo, "%02x", cp[i]));
+ }
+ break;
+ }
+
+ /* Account for data printed */
+ cp += datalen;
+ hlen -= datalen;
+
+ /* Check specification against observed length */
+ ++datalen; /* option octet */
+ if (!ZEROLENOPT(opt))
+ ++datalen; /* size octet */
+ if (datalen != len)
+ ND_PRINT((ndo, "[len %d]", len));
+ ch = ',';
+ if (opt == TCPOPT_EOL)
+ break;
+ }
+ ND_PRINT((ndo, "]"));
+ }
+
+ /*
+ * Print length field before crawling down the stack.
+ */
+ ND_PRINT((ndo, ", length %u", length));
+
+ if (length <= 0)
+ return;
+
+ /*
+ * Decode payload if necessary.
+ */
+ bp += TH_OFF(tp) * 4;
+ if ((flags & TH_RST) && ndo->ndo_vflag) {
+ print_tcp_rst_data(ndo, bp, length);
+ return;
+ }
+
+ if (ndo->ndo_packettype) {
+ switch (ndo->ndo_packettype) {
+ case PT_ZMTP1:
+ zmtp1_print(ndo, bp, length);
+ break;
+ }
+ return;
+ }
+
+ if (sport == TELNET_PORT || dport == TELNET_PORT) {
+ if (!ndo->ndo_qflag && ndo->ndo_vflag)
+ telnet_print(ndo, bp, length);
+ } else if (sport == BGP_PORT || dport == BGP_PORT)
+ bgp_print(ndo, bp, length);
+ else if (sport == PPTP_PORT || dport == PPTP_PORT)
+ pptp_print(ndo, bp);
#ifdef TCPDUMP_DO_SMB
- else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
- nbt_tcp_print(bp, length);
+ else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
+ nbt_tcp_print(ndo, bp, length);
+ else if (sport == SMB_PORT || dport == SMB_PORT)
+ smb_tcp_print(ndo, bp, length);
#endif
- else if (sport == BEEP_PORT || dport == BEEP_PORT)
- beep_print(bp, length);
- else if (length > 2 &&
- (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
- sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
- /*
- * TCP DNS query has 2byte length at the head.
- * XXX packet could be unaligned, it can go strange
- */
- ns_print(bp + 2, length - 2, 0);
- } 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);
- }
- return;
-bad:
- fputs("[bad opt]", stdout);
- if (ch != '\0')
- putchar('>');
- return;
-trunc:
- fputs("[|tcp]", stdout);
- if (ch != '\0')
- putchar('>');
+ else if (sport == BEEP_PORT || dport == BEEP_PORT)
+ beep_print(ndo, bp, length);
+ else if (sport == OPENFLOW_PORT_OLD || dport == OPENFLOW_PORT_OLD ||
+ sport == OPENFLOW_PORT_IANA || dport == OPENFLOW_PORT_IANA)
+ openflow_print(ndo, bp, length);
+ else if (length > 2 &&
+ (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
+ sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
+ /*
+ * TCP DNS query has 2byte length at the head.
+ * XXX packet could be unaligned, it can go strange
+ */
+ ns_print(ndo, bp + 2, length - 2, 0);
+ } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
+ msdp_print(ndo, bp, length);
+ } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) {
+ rpki_rtr_print(ndo, bp, length);
+ }
+ else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
+ ldp_print(ndo, bp, length);
+ }
+ else if ((sport == NFS_PORT || dport == NFS_PORT) &&
+ length >= 4 && ND_TTEST2(*bp, 4)) {
+ /*
+ * 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.
+ */
+ uint32_t fraglen;
+ register struct sunrpc_msg *rp;
+ enum sunrpc_msg_type direction;
+
+ fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
+ if (fraglen > (length) - 4)
+ fraglen = (length) - 4;
+ rp = (struct sunrpc_msg *)(bp + 4);
+ if (ND_TTEST(rp->rm_direction)) {
+ direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
+ if (dport == NFS_PORT && direction == SUNRPC_CALL) {
+ ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
+ nfsreq_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip);
+ return;
+ }
+ if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
+ ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
+ nfsreply_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip);
+ return;
+ }
+ }
+ }
+
+ return;
+ bad:
+ ND_PRINT((ndo, "[bad opt]"));
+ if (ch != '\0')
+ ND_PRINT((ndo, ">"));
+ return;
+ trunc:
+ ND_PRINT((ndo, "[|tcp]"));
+ if (ch != '\0')
+ ND_PRINT((ndo, ">"));
}
/*
*/
static void
-print_tcp_rst_data(register const u_char *sp, u_int length)
+print_tcp_rst_data(netdissect_options *ndo,
+ register const u_char *sp, u_int length)
{
- int c;
-
- if (TTEST2(*sp, length))
- printf(" [RST");
- else
- printf(" [!RST");
- if (length > MAX_RST_DATA_LEN) {
- length = MAX_RST_DATA_LEN; /* can use -X for longer */
- putchar('+'); /* indicate we truncate */
- }
- putchar(' ');
- while (length-- && sp <= snapend) {
- c = *sp++;
- safeputchar(c);
- }
- putchar(']');
+ int c;
+
+ ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST"));
+ if (length > MAX_RST_DATA_LEN) {
+ length = MAX_RST_DATA_LEN; /* can use -X for longer */
+ ND_PRINT((ndo, "+")); /* indicate we truncate */
+ }
+ ND_PRINT((ndo, " "));
+ while (length-- && sp <= ndo->ndo_snapend) {
+ c = *sp++;
+ safeputchar(ndo, c);
+ }
+ ND_PRINT((ndo, "]"));
}
#ifdef HAVE_LIBCRYPTO
+USES_APPLE_DEPRECATED_API
static int
-tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
- const u_char *data, int length, const u_char *rcvsig)
+tcp_verify_signature(netdissect_options *ndo,
+ const struct ip *ip, const struct tcphdr *tp,
+ const u_char *data, int length, const u_char *rcvsig)
{
struct tcphdr tp1;
- char sig[TCP_SIGLEN];
- char zero_proto = 0;
- MD5_CTX ctx;
- u_short savecsum, tlen;
-
- tp1 = *tp;
-
- if (tcpmd5secret == NULL)
- return (-1);
-
- 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));
-
- /*
- * Step 2: Update MD5 hash with TCP header, excluding options.
- * The TCP checksum must be set to zero.
- */
- 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.
- */
- if (length > 0)
- MD5_Update(&ctx, data, length);
- /*
- * Step 4: Update MD5 hash with shared secret.
- */
- MD5_Update(&ctx, tcpmd5secret, strlen(tcpmd5secret));
- MD5_Final(sig, &ctx);
-
- return (memcmp(rcvsig, sig, 16));
+ u_char sig[TCP_SIGLEN];
+ char zero_proto = 0;
+ MD5_CTX ctx;
+ uint16_t savecsum, tlen;
+#ifdef INET6
+ struct ip6_hdr *ip6;
+ uint32_t len32;
+ uint8_t nxt;
+#endif
+
+ if (data + length > ndo->ndo_snapend) {
+ ND_PRINT((ndo, "snaplen too short, "));
+ return (CANT_CHECK_SIGNATURE);
+ }
+
+ tp1 = *tp;
+
+ if (ndo->ndo_sigsecret == NULL) {
+ ND_PRINT((ndo, "shared secret not supplied with -M, "));
+ return (CANT_CHECK_SIGNATURE);
+ }
+
+ MD5_Init(&ctx);
+ /*
+ * Step 1: Update MD5 hash with IP pseudo-header.
+ */
+ 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(EXTRACT_16BITS(&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 {
+#ifdef INET6
+ ND_PRINT((ndo, "IP version not 4 or 6, "));
+#else
+ ND_PRINT((ndo, "IP version not 4, "));
+#endif
+ return (CANT_CHECK_SIGNATURE);
+ }
+
+ /*
+ * Step 2: Update MD5 hash with TCP header, excluding options.
+ * The TCP checksum must be set to zero.
+ */
+ 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.
+ */
+ if (length > 0)
+ MD5_Update(&ctx, data, length);
+ /*
+ * Step 4: Update MD5 hash with shared secret.
+ */
+ MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));
+ MD5_Final(sig, &ctx);
+
+ if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
+ return (SIGNATURE_VALID);
+ else
+ return (SIGNATURE_INVALID);
}
+USES_APPLE_RST
#endif /* HAVE_LIBCRYPTO */
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */
projects / tcpdump / blobdiff