6baefd92e4
- more length overflow check for ip6 related parsing - protocol decode fixes - add dhcp6 parser XXX how should we maintain usr.sbin/tcpdump for years to come? relationship with www.tcpdump.org codebase?
562 lines
13 KiB
C
562 lines
13 KiB
C
/* $NetBSD: print-tcp.c,v 1.16 1999/12/10 05:45:08 itojun Exp $ */
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/*
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* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code distributions
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* retain the above copyright notice and this paragraph in its entirety, (2)
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* distributions including binary code include the above copyright notice and
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* this paragraph in its entirety in the documentation or other materials
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* provided with the distribution, and (3) all advertising materials mentioning
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* features or use of this software display the following acknowledgement:
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* ``This product includes software developed by the University of California,
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* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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* the University nor the names of its contributors may be used to endorse
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* or promote products derived from this software without specific prior
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* written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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#if 0
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static const char rcsid[] =
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"@(#) Header: print-tcp.c,v 1.55 97/06/15 13:20:28 leres Exp (LBL)";
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#else
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__RCSID("$NetBSD: print-tcp.c,v 1.16 1999/12/10 05:45:08 itojun Exp $");
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#endif
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#endif
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#include <sys/param.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/tcp.h>
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#include <netinet/tcpip.h>
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#include <rpc/rpc.h>
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#ifdef HAVE_MEMORY_H
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#include <memory.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#ifdef INET6
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#include <netinet/ip6.h>
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#endif
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#include "interface.h"
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#include "addrtoname.h"
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#include "extract.h"
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#include "nfs.h"
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#ifndef TCPOPT_WSCALE
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#define TCPOPT_WSCALE 3 /* window scale factor (rfc1072) */
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#endif
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#ifndef TCPOPT_SACKOK
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#define TCPOPT_SACKOK 4 /* selective ack ok (rfc1072) */
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#endif
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#ifndef TCPOPT_SACK
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#define TCPOPT_SACK 5 /* selective ack (rfc1072) */
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#endif
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#ifndef TCPOPT_ECHO
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#define TCPOPT_ECHO 6 /* echo (rfc1072) */
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#endif
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#ifndef TCPOPT_ECHOREPLY
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#define TCPOPT_ECHOREPLY 7 /* echo (rfc1072) */
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#endif
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#ifndef TCPOPT_TIMESTAMP
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#define TCPOPT_TIMESTAMP 8 /* timestamps (rfc1323) */
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#endif
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#ifndef TCPOPT_CC
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#define TCPOPT_CC 11 /* T/TCP CC options (rfc1644) */
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#endif
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#ifndef TCPOPT_CCNEW
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#define TCPOPT_CCNEW 12 /* T/TCP CC options (rfc1644) */
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#endif
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#ifndef TCPOPT_CCECHO
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#define TCPOPT_CCECHO 13 /* T/TCP CC options (rfc1644) */
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#endif
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struct tha {
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#ifndef INET6
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struct in_addr src;
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struct in_addr dst;
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#else
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struct in6_addr src;
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struct in6_addr dst;
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#endif /*INET6*/
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u_int port;
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};
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struct tcp_seq_hash {
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struct tcp_seq_hash *nxt;
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struct tha addr;
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tcp_seq seq;
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tcp_seq ack;
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};
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#define TSEQ_HASHSIZE 919
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/* These tcp optinos do not have the size octet */
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#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
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static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
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static int tcp_cksum(register const struct ip *ip,
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register const struct tcphdr *tp,
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register int len)
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{
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int i, tlen;
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union phu {
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struct phdr {
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u_int32_t src;
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u_int32_t dst;
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u_char mbz;
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u_char proto;
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u_int16_t len;
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} ph;
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u_int16_t pa[6];
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} phu;
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register const u_int16_t *sp;
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u_int32_t sum;
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tlen = ntohs(ip->ip_len) - ((const char *)tp-(const char*)ip);
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/* pseudo-header.. */
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phu.ph.len = htons(tlen);
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phu.ph.mbz = 0;
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phu.ph.proto = ip->ip_p;
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memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
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memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
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sp = &phu.pa[0];
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sum = sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5];
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sp = (const u_int16_t *)tp;
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for (i=0; i<(tlen&~1); i+= 2)
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sum += *sp++;
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if (tlen & 1) {
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sum += htons( (*(const char *)sp) << 8);
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}
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while (sum > 0xffff)
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sum = (sum & 0xffff) + (sum >> 16);
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sum = ~sum & 0xffff;
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return (sum);
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}
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void
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tcp_print(register const u_char *bp, register u_int length,
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register const u_char *bp2)
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{
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register const struct tcphdr *tp;
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register const struct ip *ip;
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register u_char flags;
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register int hlen;
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register char ch;
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u_int16_t sport, dport, win, urp;
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tcp_seq seq, ack;
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#ifdef INET6
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register const struct ip6_hdr *ip6;
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#endif
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tp = (struct tcphdr *)bp;
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ip = (struct ip *)bp2;
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#ifdef INET6
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if (ip->ip_v == 6)
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ip6 = (struct ip6_hdr *)bp2;
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else
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ip6 = NULL;
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#endif /*INET6*/
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ch = '\0';
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TCHECK(*tp);
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if (length < sizeof(*tp)) {
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(void)printf("truncated-tcp %d", length);
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return;
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}
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sport = ntohs(tp->th_sport);
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dport = ntohs(tp->th_dport);
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seq = ntohl(tp->th_seq);
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ack = ntohl(tp->th_ack);
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win = ntohs(tp->th_win);
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urp = ntohs(tp->th_urp);
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hlen = tp->th_off * 4;
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/*
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* If data present and NFS port used, assume NFS.
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* Pass offset of data plus 4 bytes for RPC TCP msg length
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* to NFS print routines.
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*/
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if (!qflag) {
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u_int len = length - hlen;
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if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
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dport == NFS_PORT) {
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nfsreq_print((u_char *)tp + hlen + 4, len,
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(u_char *)ip);
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return;
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}
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else if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
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sport == NFS_PORT) {
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nfsreply_print((u_char *)tp + hlen + 4, len,
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(u_char *)ip);
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return;
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}
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}
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#ifdef INET6
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if (ip6) {
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if (bp == (u_char *)(ip6 + 1)) {
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(void)printf("%s.%s > %s.%s: ",
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ip6addr_string(&ip6->ip6_src),
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tcpport_string(sport),
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ip6addr_string(&ip6->ip6_dst),
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tcpport_string(dport));
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} else {
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(void)printf("%s > %s: ",
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tcpport_string(sport), tcpport_string(dport));
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}
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} else
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#endif /*INET6*/
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{
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if (bp == (u_char *)(ip + 1)) {
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(void)printf("%s.%s > %s.%s: ",
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ipaddr_string(&ip->ip_src),
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tcpport_string(sport),
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ipaddr_string(&ip->ip_dst),
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tcpport_string(dport));
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} else {
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(void)printf("%s > %s: ",
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tcpport_string(sport), tcpport_string(dport));
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}
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}
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if (qflag) {
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(void)printf("tcp %d", length - tp->th_off * 4);
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return;
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}
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#ifdef TH_ECN
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if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|TH_ECN))
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#else
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if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH))
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#endif
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{
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if (flags & TH_SYN)
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putchar('S');
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if (flags & TH_FIN)
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putchar('F');
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if (flags & TH_RST)
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putchar('R');
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if (flags & TH_PUSH)
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putchar('P');
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#ifdef TH_ECN
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if (flags & TH_ECN)
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putchar('C');
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#endif
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} else
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putchar('.');
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if (!Sflag && (flags & TH_ACK)) {
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register struct tcp_seq_hash *th;
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register int rev;
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struct tha tha;
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/*
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* Find (or record) the initial sequence numbers for
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* this conversation. (we pick an arbitrary
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* collating order so there's only one entry for
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* both directions).
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*/
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#ifdef INET6
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bzero(&tha, sizeof(tha));
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rev = 0;
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if (ip6) {
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if (sport > dport) {
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rev = 1;
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} else if (sport == dport) {
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int i;
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for (i = 0; i < 4; i++) {
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if (((u_int32_t *)(&ip6->ip6_src))[i] >
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((u_int32_t *)(&ip6->ip6_dst))[i]) {
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rev = 1;
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break;
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}
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}
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}
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if (rev) {
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tha.src = ip6->ip6_dst;
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tha.dst = ip6->ip6_src;
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tha.port = dport << 16 | sport;
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} else {
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tha.dst = ip6->ip6_dst;
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tha.src = ip6->ip6_src;
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tha.port = sport << 16 | dport;
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}
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} else {
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if (sport > dport ||
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(sport == dport &&
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ip->ip_src.s_addr > ip->ip_dst.s_addr)) {
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rev = 1;
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}
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if (rev) {
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*(struct in_addr *)&tha.src = ip->ip_dst;
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*(struct in_addr *)&tha.dst = ip->ip_src;
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tha.port = dport << 16 | sport;
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} else {
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*(struct in_addr *)&tha.dst = ip->ip_dst;
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*(struct in_addr *)&tha.src = ip->ip_src;
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tha.port = sport << 16 | dport;
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}
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}
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#else
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if (sport < dport ||
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(sport == dport &&
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ip->ip_src.s_addr < ip->ip_dst.s_addr)) {
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tha.src = ip->ip_src, tha.dst = ip->ip_dst;
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tha.port = sport << 16 | dport;
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rev = 0;
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} else {
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tha.src = ip->ip_dst, tha.dst = ip->ip_src;
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tha.port = dport << 16 | sport;
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rev = 1;
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}
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#endif
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for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
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th->nxt; th = th->nxt)
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if (!memcmp((char *)&tha, (char *)&th->addr,
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sizeof(th->addr)))
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break;
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if (!th->nxt || flags & TH_SYN) {
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/* didn't find it or new conversation */
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if (th->nxt == NULL) {
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th->nxt = (struct tcp_seq_hash *)
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calloc(1, sizeof(*th));
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if (th->nxt == NULL)
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error("tcp_print: calloc");
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}
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th->addr = tha;
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if (rev)
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th->ack = seq, th->seq = ack - 1;
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else
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th->seq = seq, th->ack = ack - 1;
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} else {
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if (rev)
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seq -= th->ack, ack -= th->seq;
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else
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seq -= th->seq, ack -= th->ack;
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}
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}
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hlen = tp->th_off * 4;
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if (hlen > length) {
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(void)printf(" [bad hdr length]");
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return;
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}
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if (ip->ip_v == 4 && vflag) {
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int sum;
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if (TTEST2(tp->th_sport, length)) {
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sum = tcp_cksum(ip, tp, length);
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if (sum != 0)
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(void)printf(" [bad tcp cksum %x!]", sum);
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else
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(void)printf(" [tcp sum ok]");
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}
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}
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length -= hlen;
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if (length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
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(void)printf(" %lu:%lu(%d)", (long) seq, (long) (seq + length),
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length);
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if (flags & TH_ACK)
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(void)printf(" ack %u", ack);
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(void)printf(" win %d", win);
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if (flags & TH_URG)
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(void)printf(" urg %d", urp);
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/*
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* Handle any options.
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*/
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if ((hlen -= sizeof(*tp)) > 0) {
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register const u_char *cp;
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register int i, opt, len, datalen;
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cp = (const u_char *)tp + sizeof(*tp);
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putchar(' ');
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ch = '<';
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while (hlen > 0) {
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putchar(ch);
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TCHECK(*cp);
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opt = *cp++;
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if (ZEROLENOPT(opt))
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len = 1;
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else {
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TCHECK(*cp);
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len = *cp++; /* total including type, len */
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if (len < 2 || len > hlen)
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goto bad;
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--hlen; /* account for length byte */
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}
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--hlen; /* account for type byte */
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datalen = 0;
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/* Bail if "l" bytes of data are not left or were not captured */
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#define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
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switch (opt) {
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case TCPOPT_MAXSEG:
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(void)printf("mss");
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datalen = 2;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_16BITS(cp));
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break;
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case TCPOPT_EOL:
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(void)printf("eol");
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break;
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case TCPOPT_NOP:
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(void)printf("nop");
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break;
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case TCPOPT_WSCALE:
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(void)printf("wscale");
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datalen = 1;
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LENCHECK(datalen);
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(void)printf(" %u", *cp);
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break;
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case TCPOPT_SACKOK:
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(void)printf("sackOK");
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break;
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case TCPOPT_SACK:
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(void)printf("sack");
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datalen = len - 2;
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for (i = 0; i < datalen; i += 4) {
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LENCHECK(i + 4);
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/* block-size@relative-origin */
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(void)printf(" %u@%u",
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EXTRACT_16BITS(cp + i + 2),
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EXTRACT_16BITS(cp + i));
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}
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if (datalen % 4)
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(void)printf("[len %d]", len);
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break;
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case TCPOPT_ECHO:
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(void)printf("echo");
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datalen = 4;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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break;
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case TCPOPT_ECHOREPLY:
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(void)printf("echoreply");
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datalen = 4;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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break;
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case TCPOPT_TIMESTAMP:
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(void)printf("timestamp");
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datalen = 8;
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LENCHECK(4);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp + 4));
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break;
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case TCPOPT_CC:
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(void)printf("cc");
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datalen = 4;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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break;
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case TCPOPT_CCNEW:
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(void)printf("ccnew");
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datalen = 4;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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break;
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case TCPOPT_CCECHO:
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(void)printf("ccecho");
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datalen = 4;
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LENCHECK(datalen);
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(void)printf(" %u", EXTRACT_32BITS(cp));
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break;
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default:
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(void)printf("opt-%d:", opt);
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datalen = len - 2;
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for (i = 0; i < datalen; ++i) {
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LENCHECK(i);
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(void)printf("%02x", cp[i]);
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}
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break;
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}
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/* Account for data printed */
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cp += datalen;
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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('>');
|
|
}
|
|
#ifndef TELNET_PORT
|
|
# define TELNET_PORT 23
|
|
#endif
|
|
#ifndef BGP_PORT
|
|
# define BGP_PORT 179
|
|
#endif
|
|
if (!qflag && vflag && length > 0
|
|
&& (dport == TELNET_PORT || sport == TELNET_PORT)) {
|
|
hlen = tp->th_off * 4; /* restore it */
|
|
telnet_print((u_char *)tp + hlen, length);
|
|
} else if (sport == BGP_PORT || dport == BGP_PORT) {
|
|
hlen = tp->th_off * 4; /* restore it */
|
|
bgp_print((u_char *)tp + hlen, length);
|
|
}
|
|
return;
|
|
bad:
|
|
fputs("[bad opt]", stdout);
|
|
if (ch != '\0')
|
|
putchar('>');
|
|
return;
|
|
trunc:
|
|
fputs("[|tcp]", stdout);
|
|
if (ch != '\0')
|
|
putchar('>');
|
|
}
|
|
|