static uint16_t tcp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6, const struct tcphdr *tp, u_int len) { return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len, IPPROTO_TCP); }
static int dccp6_cksum(const struct ip6_hdr *ip6, const struct dccp_hdr *dh, u_int len) { return nextproto6_cksum(ip6, (const u_int8_t *)(void *)dh, len, dccp_csum_coverage(dh, len), IPPROTO_DCCP); }
void tcp_print(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; u_int utoval; int threv; #ifdef INET6 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, 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 && hlen >= sizeof(*tp) && hlen <= length && (length - hlen) >= 4) { u_char *fraglenp; u_int32_t fraglen; register struct sunrpc_msg *rp; enum sunrpc_msg_type direction; fraglenp = (u_char *)tp + hlen; if (TTEST2(*fraglenp, 4)) { fraglen = EXTRACT_32BITS(fraglenp) & 0x7FFFFFFF; if (fraglen > (length - hlen) - 4) fraglen = (length - hlen) - 4; rp = (struct sunrpc_msg *)(fraglenp + 4); if (TTEST(rp->rm_direction)) { direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction); if (dport == NFS_PORT && direction == SUNRPC_CALL) { nfsreq_print((u_char *)rp, fraglen, (u_char *)ip); return; } if (sport == NFS_PORT && direction == SUNRPC_REPLY) { nfsreply_print((u_char *)rp, fraglen, (u_char *)ip); return; } } } } #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)); } } 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); 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 - hlen); if (hlen > length) { (void)printf(" [bad hdr length %u - too long, > %u]", hlen, length); } return; } flags = tp->th_flags; printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)); 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 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 { /* * Zero out the tha structure; the src and dst * fields are big enough to hold an IPv6 * address, but we only have IPv4 addresses * and thus must clear out the remaining 124 * bits. * * XXX - should we just clear those bytes after * copying the IPv4 addresses, rather than * zeroing out the entire structure and then * overwriting some of the zeroes? * * XXX - this could fail if we see TCP packets * with an IPv6 address with the lower 124 bits * all zero and also see TCP packes with an * IPv4 address with the same 32 bits as the * upper 32 bits of the IPv6 address in question. * Can that happen? Is it likely enough to be * an issue? */ memset(&tha, 0, sizeof(tha)); 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 %u - too long, > %u]", hlen, length); return; } if (IP_V(ip) == 4 && vflag && !Kflag && !fragmented) { 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(" (incorrect -> 0x%04x)",in_cksum_shouldbe(tcp_sum, sum)); } else (void)printf(" (correct)"); } } #ifdef INET6 if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !Kflag && !fragmented) { u_int16_t sum,tcp_sum; if (TTEST2(tp->th_sport, length)) { sum = nextproto6_cksum(ip6, (u_short *)tp, length, IPPROTO_TCP); (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 length -= hlen; if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { (void)printf(", seq %u", seq); if (length > 0) { (void)printf(":%u", seq + 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); printf(", options ["); while (hlen > 0) { if (ch != '\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); } printf("%s", tok2str(tcp_option_values, "Unknown Option %u", opt)); switch (opt) { case TCPOPT_MAXSEG: datalen = 2; LENCHECK(datalen); (void)printf(" %u", EXTRACT_16BITS(cp)); break; case TCPOPT_WSCALE: datalen = 1; LENCHECK(datalen); (void)printf(" %u", *cp); break; case TCPOPT_SACK: datalen = len - 2; if (datalen % 8 != 0) { (void)printf("malformed sack"); } else { u_int32_t s, e; (void)printf(" %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); } } 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); (void)printf(" %u", EXTRACT_32BITS(cp)); break; case TCPOPT_TIMESTAMP: datalen = 8; LENCHECK(datalen); (void)printf(" val %u ecr %u", EXTRACT_32BITS(cp), EXTRACT_32BITS(cp + 4)); break; case TCPOPT_SIGNATURE: datalen = TCP_SIGLEN; LENCHECK(datalen); #ifdef HAVE_LIBCRYPTO switch (tcp_verify_signature(ip, tp, bp + TH_OFF(tp) * 4, length, cp)) { case SIGNATURE_VALID: (void)printf("valid"); 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]); #endif break; case TCPOPT_AUTH: (void)printf("keyid %d", *cp++); datalen = len - 3; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%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); (void)printf("0x%x", utoval); if (utoval & 0x0001) utoval = (utoval >> 1) * 60; else utoval >>= 1; (void)printf(" %u", utoval); break; default: 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(']'); }
void 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; uint16_t sport, dport, win, urp; uint32_t seq, ack, thseq, thack; u_int utoval; uint16_t magic; register int rev; register const struct ip6_hdr *ip6; tp = (const struct tcphdr *)bp; ip = (const struct ip *)bp2; if (IP_V(ip) == 6) ip6 = (const struct ip6_hdr *)bp2; else ip6 = NULL; 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; } sport = EXTRACT_16BITS(&tp->th_sport); dport = EXTRACT_16BITS(&tp->th_dport); hlen = TH_OFF(tp) * 4; if (ip6) { if (ip6->ip6_nxt == IPPROTO_TCP) { ND_PRINT((ndo, "%s.%s > %s.%s: ", ip6addr_string(ndo, &ip6->ip6_src), tcpport_string(ndo, sport), ip6addr_string(ndo, &ip6->ip6_dst), tcpport_string(ndo, dport))); } else { ND_PRINT((ndo, "%s > %s: ", tcpport_string(ndo, sport), tcpport_string(ndo, dport))); } } else { if (ip->ip_p == IPPROTO_TCP) { ND_PRINT((ndo, "%s.%s > %s.%s: ", ipaddr_string(ndo, &ip->ip_src), tcpport_string(ndo, sport), ipaddr_string(ndo, &ip->ip_dst), tcpport_string(ndo, dport))); } else { ND_PRINT((ndo, "%s > %s: ", tcpport_string(ndo, sport), tcpport_string(ndo, 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; 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) (*ndo->ndo_error)(ndo, "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 { register struct tcp_seq_hash *th; struct tcp_seq_hash *tcp_seq_hash; struct tha tha; tcp_seq_hash = tcp_seq_hash4; if (sport > dport) rev = 1; else if (sport == dport) { if (UNALIGNED_MEMCMP(&ip->ip_src, &ip->ip_dst, sizeof ip->ip_dst) > 0) rev = 1; } if (rev) { UNALIGNED_MEMCPY(&tha.src, &ip->ip_dst, sizeof ip->ip_dst); UNALIGNED_MEMCPY(&tha.dst, &ip->ip_src, sizeof ip->ip_src); tha.port = dport << 16 | sport; } else { UNALIGNED_MEMCPY(&tha.dst, &ip->ip_dst, sizeof ip->ip_dst); UNALIGNED_MEMCPY(&tha.src, &ip->ip_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) (*ndo->ndo_error)(ndo, "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)")); } } 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)")); } } } 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; 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, "invalid 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 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) ND_PRINT((ndo, "%02x", cp[i])); #endif 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_FASTOPEN: datalen = len - 2; LENCHECK(datalen); print_tcp_fastopen_option(ndo, cp, datalen, FALSE); 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 RFC 7413 */ print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE); 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, "]")); }
static int dccp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6, const struct dccp_hdr *dh, u_int len) { return nextproto6_cksum(ndo, ip6, (const uint8_t *)(const void *)dh, len, dccp_csum_coverage(dh, len), IPPROTO_DCCP); }
void tcp_print(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; u_int utoval; int threv; #ifdef INET6 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, 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 && hlen >= sizeof(*tp) && hlen <= length && (length - hlen) >= 4) { u_char *fraglenp; u_int32_t fraglen; register struct sunrpc_msg *rp; enum sunrpc_msg_type direction; fraglenp = (u_char *)tp + hlen; if (TTEST2(*fraglenp, 4)) { fraglen = EXTRACT_32BITS(fraglenp) & 0x7FFFFFFF; if (fraglen > (length - hlen) - 4) fraglen = (length - hlen) - 4; rp = (struct sunrpc_msg *)(fraglenp + 4); if (TTEST(rp->rm_direction)) { direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction); if (dport == NFS_PORT && direction == SUNRPC_CALL) { nfsreq_print((u_char *)rp, fraglen, (u_char *)ip); return; } if (sport == NFS_PORT && direction == SUNRPC_REPLY) { nfsreply_print((u_char *)rp, fraglen, (u_char *)ip); return; } } } } #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)); } } 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); 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 - hlen); if (hlen > length) { (void)printf(" [bad hdr length %u - too long, > %u]", hlen, length); } return; } flags = tp->th_flags; printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)); 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 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 { /* * Zero out the tha structure; the src and dst * fields are big enough to hold an IPv6 * address, but we only have IPv4 addresses * and thus must clear out the remaining 124 * bits. * * XXX - should we just clear those bytes after * copying the IPv4 addresses, rather than * zeroing out the entire structure and then * overwriting some of the zeroes? * * XXX - this could fail if we see TCP packets * with an IPv6 address with the lower 124 bits * all zero and also see TCP packes with an * IPv4 address with the same 32 bits as the * upper 32 bits of the IPv6 address in question. * Can that happen? Is it likely enough to be * an issue? */ memset(&tha, 0, sizeof(tha)); 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 %u - too long, > %u]", hlen, length); return; } if (vflag && !Kflag && !fragmented) { /* Check the checksum, if possible. */ u_int16_t sum, tcp_sum; if (IP_V(ip) == 4) { if (TTEST2(tp->th_sport, length)) { sum = tcp_cksum(ip, tp, length); tcp_sum = EXTRACT_16BITS(&tp->th_sum); (void)printf(", cksum 0x%04x", tcp_sum); if (sum != 0) (void)printf(" (incorrect -> 0x%04x)", in_cksum_shouldbe(tcp_sum, sum)); else (void)printf(" (correct)"); } } #ifdef INET6 else if (IP_V(ip) == 6 && ip6->ip6_plen) { if (TTEST2(tp->th_sport, length)) { sum = nextproto6_cksum(ip6, (const u_int8_t *)tp, length, IPPROTO_TCP); tcp_sum = EXTRACT_16BITS(&tp->th_sum); (void)printf(", cksum 0x%04x", tcp_sum); if (sum != 0) (void)printf(" (incorrect -> 0x%04x)", in_cksum_shouldbe(tcp_sum, sum)); else (void)printf(" (correct)"); } } #endif } length -= hlen; if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { (void)printf(", seq %u", seq); if (length > 0) { (void)printf(":%u", seq + 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); printf(", options ["); while (hlen > 0) { if (ch != '\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); } printf("%s", tok2str(tcp_option_values, "Unknown Option %u", opt)); switch (opt) { case TCPOPT_MAXSEG: datalen = 2; LENCHECK(datalen); (void)printf(" %u", EXTRACT_16BITS(cp)); break; case TCPOPT_WSCALE: datalen = 1; LENCHECK(datalen); (void)printf(" %u", *cp); break; case TCPOPT_SACK: datalen = len - 2; if (datalen % 8 != 0) { (void)printf("malformed sack"); } else { u_int32_t s, e; (void)printf(" %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); } } 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); (void)printf(" %u", EXTRACT_32BITS(cp)); break; case TCPOPT_TIMESTAMP: datalen = 8; LENCHECK(datalen); (void)printf(" val %u ecr %u", EXTRACT_32BITS(cp), EXTRACT_32BITS(cp + 4)); break; case TCPOPT_SIGNATURE: datalen = TCP_SIGLEN; LENCHECK(datalen); #ifdef HAVE_LIBCRYPTO switch (tcp_verify_signature(ip, tp, bp + TH_OFF(tp) * 4, length, cp)) { case SIGNATURE_VALID: (void)printf("valid"); 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]); #endif break; case TCPOPT_AUTH: (void)printf("keyid %d", *cp++); datalen = len - 3; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%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); (void)printf("0x%x", utoval); if (utoval & 0x0001) utoval = (utoval >> 1) * 60; else utoval >>= 1; (void)printf(" %u", utoval); break; case TCPOPT_MPTCP: { uint8_t subtype; datalen = 1; LENCHECK(datalen); subtype = (*cp) >> 4; printf(" %s ", tok2str(mptcp_subtypes, "Unknown MPTCP subtype %u", subtype)); switch (subtype) { case TCPOPT_MPTCP_MP_CAPABLE: { uint8_t version = (*cp) & 0x0f; uint8_t mpflags; if (version != 0) { printf(" version %u ", version); for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%02x", cp[i]); } break; } datalen += 1; LENCHECK(datalen); mpflags = cp[1]; printf("%s%s%s%s%s%s%s%s%s", (mpflags) ? "flags:" : "", (mpflags & 0x80) ? "A" : "", (mpflags & 0x40) ? "B" : "", (mpflags & 0x20) ? "C" : "", (mpflags & 0x10) ? "D" : "", (mpflags & 0x08) ? "E" : "", (mpflags & 0x04) ? "F" : "", (mpflags & 0x02) ? "G" : "", (mpflags & 0x01) ? "H" : ""); if (len == 12 || len == 20) { printf(" sndkey:"); for (i = 0; i < 8; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[2 + i]); } if (len == 20) { printf(" rcvkey:"); for (i = 0; i < 8; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[10 + i]); } } } else { printf(" unknown:"); datalen = len - 2; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%02x", cp[i]); } } break; } case TCPOPT_MPTCP_MP_JOIN: { uint8_t mpflags = (*cp) & 0x0f; /* Flags on SYN only */ if (flags & TH_SYN) { printf("%s%s%s%s%s", (mpflags) ? "flags:" : "", (mpflags & 0x08) ? "0" : "", (mpflags & 0x04) ? "1" : "", (mpflags & 0x02) ? "2" : "", (mpflags & 0x01) ? "B" : ""); } /* Address ID on SYN only, otherwise ignored */ datalen += 1; LENCHECK(datalen); if ((flags & TH_SYN)) printf(" addrid:%0x", cp[1]); if (flags == TH_SYN && len == 12) { /* Initial SYN */ printf(" rcvtok:"); for (i = 0; i < 4; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[2 + i]); } printf(" sndrand:"); for (i = 0; i < 4; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[6 + i]); } } else if ((flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK) && len == 16) { /* Responding SYN/ACK */ printf(" sndhmac:"); for (i = 0; i < 8; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[2 + i]); } printf(" sndrand:"); for (i = 0; i < 4; ++i) { datalen++; LENCHECK(datalen); (void)printf("%02x", cp[8 + i]); } } else if ((flags & (TH_SYN | TH_ACK)) == TH_ACK && len == 24) { /* Third ACK */ printf(" sndhmac:"); for (i = 0; i < 20; ++i) { datalen++; LENCHECK(i); (void)printf("%02x", cp[2 + i]); } } else { datalen = len - 2; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%02x", cp[i]); } } break; } case TCPOPT_MPTCP_DSS: { uint8_t mpflags; u_int ack_len = 0; u_int dsn_len = 0; u_int64_t dack; u_int64_t dsn; u_int32_t sfsn; u_int16_t dlen; u_int16_t csum; datalen += 1; LENCHECK(datalen); mpflags = cp[1] & 0x1f; printf("%s%s%s%s%s%s", (mpflags) ? "flags:" : "", (mpflags & 0x10) ? "F" : "", (mpflags & 0x08) ? "m" : "", (mpflags & 0x04) ? "M" : "", (mpflags & 0x02) ? "a" : "", (mpflags & 0x01) ? "A" : ""); if ((mpflags & MPDSS_FLAG_A)) { if ((mpflags & MPDSS_FLAG_a)) { ack_len = 8; datalen += ack_len; LENCHECK(datalen); dack = EXTRACT_64BITS(cp + 2); } else { ack_len = 4; datalen += ack_len; LENCHECK(datalen); dack = EXTRACT_32BITS(cp + 2); } (void)printf(" dack: %" PRIu64, dack); } if ((mpflags & MPDSS_FLAG_M)) { if ((mpflags & MPDSS_FLAG_m)) { dsn_len = 8; datalen += dsn_len; LENCHECK(datalen); dsn = EXTRACT_64BITS(cp + 2 + ack_len); } else { dsn_len = 4; datalen += dsn_len; LENCHECK(datalen); dsn = EXTRACT_32BITS(cp + 2 + ack_len); } (void)printf(" dsn: %" PRIu64, dsn); datalen += 4; LENCHECK(datalen); sfsn = EXTRACT_32BITS(cp + 2 + ack_len + dsn_len); (void)printf(" sfsn: %" PRIu32, sfsn); datalen += 2; LENCHECK(datalen); dlen = EXTRACT_16BITS(cp + 2 + ack_len + dsn_len + 4); (void)printf(" dlen: %" PRIu16, dlen); /* * Use the length of the option to find out if * the checksum is present */ if (datalen < len - 2) { datalen += 2; LENCHECK(datalen); csum = EXTRACT_16BITS(cp + 2 + ack_len + dsn_len + 6); (void)printf(" csum: %" PRIu16, csum); } } break; } case TCPOPT_MPTCP_ADD_ADDR: { uint8_t ipvers; u_int addrlen = 0; u_int16_t port; ipvers = cp[1] & 0xf0; printf(" vers:%u", ipvers); datalen = 2; LENCHECK(datalen); printf(" addrid:%0x", cp[1]); switch (ipvers) { case 4: { datalen = 6; LENCHECK(datalen); ipaddr_string(cp + 2); break; } case 6: { datalen = 18; LENCHECK(datalen); #ifdef INET6 ip6addr_string(cp + 2); #endif break; } default: goto bad; } /* * Use the length of the option to find out if * the port is present */ if (datalen < len - 2) { datalen += 2; LENCHECK(datalen); port = EXTRACT_16BITS(cp + 2 + addrlen); printf(" port: %u", port); } break; } case TCPOPT_MPTCP_REMOVE_ADDR: datalen = len - 2; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf(" %u", cp[i]); } break; case TCPOPT_MPTCP_MP_PRIO: { uint8_t mpflags = (*cp) & 0x0f; if (mpflags == 0x01) printf("flag B"); else if (mpflags != 0) { printf("flag %c%c%c%c%c%c%c%c", mpflags & 0x80 ? '1' : '0', mpflags & 0x40 ? '1' : '0', mpflags & 0x20 ? '1' : '0', mpflags & 0x10 ? '1' : '0', mpflags & 0x08 ? '1' : '0', mpflags & 0x04 ? '1' : '0', mpflags & 0x02 ? '1' : '0', mpflags & 0x01 ? 'B' : '0'); } if (len == 4) { datalen = 2; LENCHECK(datalen); printf("%saddrid:%u", mpflags ? " " : "", cp[1]); } break; } case TCPOPT_MPTCP_MP_FAIL: datalen = 10; LENCHECK(datalen); printf(" dsn:"); for (i = 0; i < 8; ++i) { (void)printf("%02x", cp[2 + i]); } break; case TCPOPT_MPTCP_MP_FASTCLOSE: datalen = 10; LENCHECK(datalen); printf(" rcvrkey:"); for (i = 0; i < 8; ++i) { (void)printf("%02x", cp[2 + i]); } break; default: datalen = len - 2; for (i = 0; i < datalen; ++i) { LENCHECK(i); (void)printf("%02x", cp[i]); } break; } break; } default: 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(']'); }