/* * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 * The Regents of the University of California. All rights reserved. * * 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) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.63 1999/12/22 15:44:10 itojun Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #ifdef HAVE_MEMORY_H #include #endif #include #include #include #include #ifdef INET6 #include #endif #include "interface.h" #include "addrtoname.h" #include "extract.h" /* Compatibility */ #ifndef TCPOPT_WSCALE #define TCPOPT_WSCALE 3 /* window scale factor (rfc1072) */ #endif #ifndef TCPOPT_SACKOK #define TCPOPT_SACKOK 4 /* selective ack ok (rfc1072) */ #endif #ifndef TCPOPT_SACK #define TCPOPT_SACK 5 /* selective ack (rfc1072) */ #endif #ifndef TCPOPT_ECHO #define TCPOPT_ECHO 6 /* echo (rfc1072) */ #endif #ifndef TCPOPT_ECHOREPLY #define TCPOPT_ECHOREPLY 7 /* echo (rfc1072) */ #endif #ifndef TCPOPT_TIMESTAMP #define TCPOPT_TIMESTAMP 8 /* timestamps (rfc1323) */ #endif #ifndef TCPOPT_CC #define TCPOPT_CC 11 /* T/TCP CC options (rfc1644) */ #endif #ifndef TCPOPT_CCNEW #define TCPOPT_CCNEW 12 /* T/TCP CC options (rfc1644) */ #endif #ifndef TCPOPT_CCECHO #define TCPOPT_CCECHO 13 /* T/TCP CC options (rfc1644) */ #endif 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 tcp_seq_hash { struct tcp_seq_hash *nxt; struct tha addr; tcp_seq seq; tcp_seq ack; }; #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 void tcp_print(register const u_char *bp, register u_int length, register const u_char *bp2) { register const struct tcphdr *tp; register const struct ip *ip; register u_char flags; register int hlen; register char ch; u_short sport, dport, win, urp; u_int32_t seq, ack, thseq, thack; int threv; #ifdef INET6 register const struct ip6_hdr *ip6; #endif tp = (struct tcphdr *)bp; ip = (struct ip *)bp2; #ifdef INET6 if (ip->ip_v == 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 = ntohs(tp->th_sport); dport = ntohs(tp->th_dport); #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 #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)); } } TCHECK(*tp); seq = ntohl(tp->th_seq); ack = ntohl(tp->th_ack); win = ntohs(tp->th_win); urp = ntohs(tp->th_urp); if (qflag) { (void)printf("tcp %d", length - tp->th_off * 4); return; } #ifdef TH_ECN if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|TH_ECN)) #else if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH)) #endif { if (flags & TH_SYN) putchar('S'); if (flags & TH_FIN) putchar('F'); if (flags & TH_RST) putchar('R'); if (flags & TH_PUSH) putchar('P'); #ifdef TH_ECN if (flags & TH_ECN) putchar('C'); #endif } else putchar('.'); if (flags&0xc0) { printf(" ["); if (flags&0x40) printf("ECN-Echo"); if (flags&0x80) printf("%sCWR", (flags&0x40) ? "," : ""); printf("]"); } if (!Sflag && (flags & TH_ACK)) { register struct tcp_seq_hash *th; 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 bzero(&tha, sizeof(tha)); rev = 0; if (ip6) { 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 (rev) { tha.src = ip6->ip6_dst; tha.dst = ip6->ip6_src; tha.port = dport << 16 | sport; } else { tha.dst = ip6->ip6_dst; tha.src = ip6->ip6_src; tha.port = sport << 16 | dport; } } else { if (sport > dport || (sport == dport && ip->ip_src.s_addr > ip->ip_dst.s_addr)) { rev = 1; } if (rev) { *(struct in_addr *)&tha.src = ip->ip_dst; *(struct in_addr *)&tha.dst = 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; 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 = 1; } #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))) 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 { thseq = th->seq; thack = th->ack; if (rev) seq -= th->ack, ack -= th->seq; else seq -= th->seq, ack -= th->ack; } } hlen = tp->th_off * 4; if (hlen > length) { (void)printf(" [bad hdr length]"); return; } length -= hlen; if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) (void)printf(" %u:%u(%d)", 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)) > 0) { register const u_char *cp; register int i, opt, len, datalen; 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; /* 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; default: (void)printf("opt-%d:", 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 += (tp->th_off * 4); if (!qflag && vflag && length > 0 && (sport == TELNET_PORT || dport == TELNET_PORT)) telnet_print(bp, length); else if (sport == BGP_PORT || dport == BGP_PORT) bgp_print(bp, length); else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT) nbt_tcp_print(bp, length); return; bad: fputs("[bad opt]", stdout); if (ch != '\0') putchar('>'); return; trunc: fputs("[|tcp]", stdout); if (ch != '\0') putchar('>'); }