| /* $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) |
| * 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. |
| */ |
| |
| /* \summary: TCP printer */ |
| |
| #ifndef lint |
| #else |
| __RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $"); |
| #endif |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include "netdissect-stdinc.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "netdissect.h" |
| #include "addrtoname.h" |
| #include "extract.h" |
| |
| #include "diag-control.h" |
| |
| #include "tcp.h" |
| |
| #include "ip.h" |
| #include "ip6.h" |
| #include "ipproto.h" |
| #include "rpc_auth.h" |
| #include "rpc_msg.h" |
| |
| #ifdef HAVE_LIBCRYPTO |
| #include <openssl/md5.h> |
| #include "signature.h" |
| |
| static int tcp_verify_signature(netdissect_options *ndo, |
| const struct ip *ip, const struct tcphdr *tp, |
| const u_char *data, u_int length, const u_char *rcvsig); |
| #endif |
| |
| static void print_tcp_rst_data(netdissect_options *, const u_char *sp, u_int length); |
| static void print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp, |
| u_int datalen, int exp); |
| |
| #define MAX_RST_DATA_LEN 30 |
| |
| |
| struct tha { |
| nd_ipv4 src; |
| nd_ipv4 dst; |
| u_int port; |
| }; |
| |
| struct tcp_seq_hash { |
| struct tcp_seq_hash *nxt; |
| struct tha addr; |
| uint32_t seq; |
| uint32_t ack; |
| }; |
| |
| struct tha6 { |
| nd_ipv6 src; |
| nd_ipv6 dst; |
| u_int port; |
| }; |
| |
| struct tcp_seq_hash6 { |
| struct tcp_seq_hash6 *nxt; |
| struct tha6 addr; |
| uint32_t seq; |
| uint32_t ack; |
| }; |
| |
| #define TSEQ_HASHSIZE 919 |
| |
| /* These tcp options do not have the size octet */ |
| #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP) |
| |
| static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE]; |
| static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE]; |
| |
| 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 } |
| }; |
| |
| 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_SCPS, "scps" }, |
| { TCPOPT_UTO, "uto" }, |
| { TCPOPT_TCPAO, "tcp-ao" }, |
| { TCPOPT_MPTCP, "mptcp" }, |
| { TCPOPT_FASTOPEN, "tfo" }, |
| { TCPOPT_EXPERIMENT2, "exp" }, |
| { 0, NULL } |
| }; |
| |
| static uint16_t |
| tcp_cksum(netdissect_options *ndo, |
| const struct ip *ip, |
| const struct tcphdr *tp, |
| u_int len) |
| { |
| return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len, |
| IPPROTO_TCP); |
| } |
| |
| 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); |
| } |
| |
| void |
| tcp_print(netdissect_options *ndo, |
| const u_char *bp, u_int length, |
| const u_char *bp2, int fragmented) |
| { |
| const struct tcphdr *tp; |
| const struct ip *ip; |
| u_char flags; |
| u_int hlen; |
| char ch; |
| uint16_t sport, dport, win, urp; |
| uint32_t seq, ack, thseq, thack; |
| u_int utoval; |
| uint16_t magic; |
| int rev; |
| const struct ip6_hdr *ip6; |
| u_int header_len; /* Header length in bytes */ |
| |
| ndo->ndo_protocol = "tcp"; |
| 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_2(tp->th_dport)) { |
| if (ip6) { |
| ND_PRINT("%s > %s:", |
| GET_IP6ADDR_STRING(ip6->ip6_src), |
| GET_IP6ADDR_STRING(ip6->ip6_dst)); |
| } else { |
| ND_PRINT("%s > %s:", |
| GET_IPADDR_STRING(ip->ip_src), |
| GET_IPADDR_STRING(ip->ip_dst)); |
| } |
| nd_print_trunc(ndo); |
| return; |
| } |
| |
| sport = GET_BE_U_2(tp->th_sport); |
| dport = GET_BE_U_2(tp->th_dport); |
| |
| if (ip6) { |
| if (GET_U_1(ip6->ip6_nxt) == IPPROTO_TCP) { |
| ND_PRINT("%s.%s > %s.%s: ", |
| GET_IP6ADDR_STRING(ip6->ip6_src), |
| tcpport_string(ndo, sport), |
| GET_IP6ADDR_STRING(ip6->ip6_dst), |
| tcpport_string(ndo, dport)); |
| } else { |
| ND_PRINT("%s > %s: ", |
| tcpport_string(ndo, sport), tcpport_string(ndo, dport)); |
| } |
| } else { |
| if (GET_U_1(ip->ip_p) == IPPROTO_TCP) { |
| ND_PRINT("%s.%s > %s.%s: ", |
| GET_IPADDR_STRING(ip->ip_src), |
| tcpport_string(ndo, sport), |
| GET_IPADDR_STRING(ip->ip_dst), |
| tcpport_string(ndo, dport)); |
| } else { |
| ND_PRINT("%s > %s: ", |
| tcpport_string(ndo, sport), tcpport_string(ndo, dport)); |
| } |
| } |
| |
| ND_TCHECK_SIZE(tp); |
| |
| hlen = TH_OFF(tp) * 4; |
| |
| if (hlen < sizeof(*tp)) { |
| ND_PRINT(" tcp %u [bad hdr length %u - too short, < %zu]", |
| length - hlen, hlen, sizeof(*tp)); |
| return; |
| } |
| |
| seq = GET_BE_U_4(tp->th_seq); |
| ack = GET_BE_U_4(tp->th_ack); |
| win = GET_BE_U_2(tp->th_win); |
| urp = GET_BE_U_2(tp->th_urp); |
| |
| if (ndo->ndo_qflag) { |
| ND_PRINT("tcp %u", length - hlen); |
| if (hlen > length) { |
| ND_PRINT(" [bad hdr length %u - too long, > %u]", |
| hlen, length); |
| } |
| return; |
| } |
| |
| flags = GET_U_1(tp->th_flags); |
| ND_PRINT("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) { |
| struct tcp_seq_hash6 *th; |
| struct tcp_seq_hash6 *tcp_seq_hash; |
| const void *src, *dst; |
| struct tha6 tha; |
| |
| tcp_seq_hash = tcp_seq_hash6; |
| src = (const void *)ip6->ip6_src; |
| dst = (const void *)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 = ((u_int)dport) << 16 | sport; |
| } else { |
| UNALIGNED_MEMCPY(&tha.dst, dst, sizeof(ip6->ip6_dst)); |
| UNALIGNED_MEMCPY(&tha.src, src, sizeof(ip6->ip6_src)); |
| tha.port = ((u_int)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 */ |
| /* calloc() return used by the 'tcp_seq_hash6' |
| hash table: do not free() */ |
| if (th->nxt == NULL) { |
| th->nxt = (struct tcp_seq_hash6 *) |
| calloc(1, sizeof(*th)); |
| if (th->nxt == NULL) |
| (*ndo->ndo_error)(ndo, |
| S_ERR_ND_MEM_ALLOC, |
| "%s: calloc", __func__); |
| } |
| 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 { |
| 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 = ((u_int)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 = ((u_int)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 */ |
| /* calloc() return used by the 'tcp_seq_hash4' |
| hash table: do not free() */ |
| if (th->nxt == NULL) { |
| th->nxt = (struct tcp_seq_hash *) |
| calloc(1, sizeof(*th)); |
| if (th->nxt == NULL) |
| (*ndo->ndo_error)(ndo, |
| S_ERR_ND_MEM_ALLOC, |
| "%s: calloc", __func__); |
| } |
| 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(" [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_TTEST_LEN(tp->th_sport, length)) { |
| sum = tcp_cksum(ndo, ip, tp, length); |
| tcp_sum = GET_BE_U_2(tp->th_sum); |
| |
| ND_PRINT(", cksum 0x%04x", tcp_sum); |
| if (sum != 0) |
| ND_PRINT(" (incorrect -> 0x%04x)", |
| in_cksum_shouldbe(tcp_sum, sum)); |
| else |
| ND_PRINT(" (correct)"); |
| } |
| } else if (IP_V(ip) == 6) { |
| if (ND_TTEST_LEN(tp->th_sport, length)) { |
| sum = tcp6_cksum(ndo, ip6, tp, length); |
| tcp_sum = GET_BE_U_2(tp->th_sum); |
| |
| ND_PRINT(", cksum 0x%04x", tcp_sum); |
| if (sum != 0) |
| ND_PRINT(" (incorrect -> 0x%04x)", |
| in_cksum_shouldbe(tcp_sum, sum)); |
| else |
| ND_PRINT(" (correct)"); |
| |
| } |
| } |
| } |
| |
| length -= hlen; |
| if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { |
| ND_PRINT(", seq %u", seq); |
| |
| if (length > 0) { |
| ND_PRINT(":%u", seq + length); |
| } |
| } |
| |
| if (flags & TH_ACK) { |
| ND_PRINT(", ack %u", ack); |
| } |
| |
| ND_PRINT(", win %u", win); |
| |
| if (flags & TH_URG) |
| ND_PRINT(", urg %u", urp); |
| /* |
| * Handle any options. |
| */ |
| if (hlen > sizeof(*tp)) { |
| const u_char *cp; |
| u_int i, opt, datalen; |
| u_int len; |
| |
| hlen -= sizeof(*tp); |
| cp = (const u_char *)tp + sizeof(*tp); |
| ND_PRINT(", options ["); |
| while (hlen > 0) { |
| if (ch != '\0') |
| ND_PRINT("%c", ch); |
| opt = GET_U_1(cp); |
| cp++; |
| if (ZEROLENOPT(opt)) |
| len = 1; |
| else { |
| len = GET_U_1(cp); |
| 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_TCHECK_LEN(cp, l); } |
| |
| |
| ND_PRINT("%s", tok2str(tcp_option_values, "unknown-%u", opt)); |
| |
| switch (opt) { |
| |
| case TCPOPT_MAXSEG: |
| datalen = 2; |
| LENCHECK(datalen); |
| ND_PRINT(" %u", GET_BE_U_2(cp)); |
| break; |
| |
| case TCPOPT_WSCALE: |
| datalen = 1; |
| LENCHECK(datalen); |
| ND_PRINT(" %u", GET_U_1(cp)); |
| break; |
| |
| case TCPOPT_SACK: |
| datalen = len - 2; |
| if (datalen % 8 != 0) { |
| ND_PRINT(" invalid sack"); |
| } else { |
| uint32_t s, e; |
| |
| ND_PRINT(" %u ", datalen / 8); |
| for (i = 0; i < datalen; i += 8) { |
| LENCHECK(i + 4); |
| s = GET_BE_U_4(cp + i); |
| LENCHECK(i + 8); |
| e = GET_BE_U_4(cp + i + 4); |
| if (rev) { |
| s -= thseq; |
| e -= thseq; |
| } else { |
| s -= thack; |
| e -= thack; |
| } |
| ND_PRINT("{%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(" %u", GET_BE_U_4(cp)); |
| break; |
| |
| case TCPOPT_TIMESTAMP: |
| datalen = 8; |
| LENCHECK(datalen); |
| ND_PRINT(" val %u ecr %u", |
| GET_BE_U_4(cp), |
| GET_BE_U_4(cp + 4)); |
| break; |
| |
| case TCPOPT_SIGNATURE: |
| datalen = TCP_SIGLEN; |
| LENCHECK(datalen); |
| ND_PRINT(" "); |
| #ifdef HAVE_LIBCRYPTO |
| switch (tcp_verify_signature(ndo, ip, tp, |
| bp + TH_OFF(tp) * 4, length, cp)) { |
| |
| case SIGNATURE_VALID: |
| ND_PRINT("valid"); |
| break; |
| |
| case SIGNATURE_INVALID: |
| nd_print_invalid(ndo); |
| break; |
| |
| case CANT_CHECK_SIGNATURE: |
| ND_PRINT("can't check - "); |
| for (i = 0; i < TCP_SIGLEN; ++i) |
| ND_PRINT("%02x", |
| GET_U_1(cp + i)); |
| break; |
| } |
| #else |
| for (i = 0; i < TCP_SIGLEN; ++i) |
| ND_PRINT("%02x", GET_U_1(cp + i)); |
| #endif |
| break; |
| |
| case TCPOPT_SCPS: |
| datalen = 2; |
| LENCHECK(datalen); |
| ND_PRINT(" cap %02x id %u", GET_U_1(cp), |
| GET_U_1(cp + 1)); |
| break; |
| |
| case TCPOPT_TCPAO: |
| datalen = len - 2; |
| /* RFC 5925 Section 2.2: |
| * "The Length value MUST be greater than or equal to 4." |
| * (This includes the Kind and Length fields already processed |
| * at this point.) |
| */ |
| if (datalen < 2) { |
| nd_print_invalid(ndo); |
| } else { |
| LENCHECK(1); |
| ND_PRINT(" keyid %u", GET_U_1(cp)); |
| LENCHECK(2); |
| ND_PRINT(" rnextkeyid %u", |
| GET_U_1(cp + 1)); |
| if (datalen > 2) { |
| ND_PRINT(" mac 0x"); |
| for (i = 2; i < datalen; i++) { |
| LENCHECK(i + 1); |
| ND_PRINT("%02x", |
| GET_U_1(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 = GET_BE_U_2(cp); |
| ND_PRINT(" 0x%x", utoval); |
| if (utoval & 0x0001) |
| utoval = (utoval >> 1) * 60; |
| else |
| utoval >>= 1; |
| ND_PRINT(" %u", utoval); |
| break; |
| |
| case TCPOPT_MPTCP: |
| { |
| const u_char *snapend_save; |
| int ret; |
| |
| datalen = len - 2; |
| LENCHECK(datalen); |
| /* Update the snapend to the end of the option |
| * before calling mptcp_print(). Some options |
| * (MPTCP or others) may be present after a |
| * MPTCP option. This prevents that, in |
| * mptcp_print(), the remaining length < the |
| * remaining caplen. |
| */ |
| snapend_save = ndo->ndo_snapend; |
| ndo->ndo_snapend = ND_MIN(cp - 2 + len, |
| ndo->ndo_snapend); |
| ret = mptcp_print(ndo, cp - 2, len, flags); |
| ndo->ndo_snapend = snapend_save; |
| if (!ret) |
| goto bad; |
| break; |
| } |
| |
| case TCPOPT_FASTOPEN: |
| datalen = len - 2; |
| LENCHECK(datalen); |
| ND_PRINT(" "); |
| print_tcp_fastopen_option(ndo, cp, datalen, FALSE); |
| break; |
| |
| case TCPOPT_EXPERIMENT2: |
| datalen = len - 2; |
| LENCHECK(datalen); |
| if (datalen < 2) |
| goto bad; |
| /* RFC6994 */ |
| magic = GET_BE_U_2(cp); |
| ND_PRINT("-"); |
| |
| 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("%04x", magic); |
| break; |
| } |
| break; |
| |
| default: |
| datalen = len - 2; |
| if (datalen) |
| ND_PRINT(" 0x"); |
| for (i = 0; i < datalen; ++i) { |
| LENCHECK(i + 1); |
| ND_PRINT("%02x", GET_U_1(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("[len %u]", len); |
| ch = ','; |
| if (opt == TCPOPT_EOL) |
| break; |
| } |
| ND_PRINT("]"); |
| } |
| |
| /* |
| * Print length field before crawling down the stack. |
| */ |
| ND_PRINT(", length %u", length); |
| |
| if (length == 0) |
| return; |
| |
| /* |
| * Decode payload if necessary. |
| */ |
| header_len = TH_OFF(tp) * 4; |
| /* |
| * Do a bounds check before decoding the payload. |
| * At least the header data is required. |
| */ |
| if (!ND_TTEST_LEN(bp, header_len)) { |
| ND_PRINT(" [remaining caplen(%u) < header length(%u)]", |
| ND_BYTES_AVAILABLE_AFTER(bp), header_len); |
| nd_trunc_longjmp(ndo); |
| } |
| bp += header_len; |
| 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; |
| case PT_RESP: |
| resp_print(ndo, bp, length); |
| break; |
| case PT_DOMAIN: |
| /* over_tcp: TRUE, is_mdns: FALSE */ |
| domain_print(ndo, bp, length, TRUE, FALSE); |
| break; |
| } |
| return; |
| } |
| |
| if (IS_SRC_OR_DST_PORT(TELNET_PORT)) { |
| telnet_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) { |
| ND_PRINT(": "); |
| smtp_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(WHOIS_PORT)) { |
| ND_PRINT(": "); |
| whois_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(BGP_PORT)) |
| bgp_print(ndo, bp, length); |
| else if (IS_SRC_OR_DST_PORT(PPTP_PORT)) |
| pptp_print(ndo, bp); |
| else if (IS_SRC_OR_DST_PORT(REDIS_PORT)) |
| resp_print(ndo, bp, length); |
| else if (IS_SRC_OR_DST_PORT(SSH_PORT)) |
| ssh_print(ndo, bp, length); |
| #ifdef ENABLE_SMB |
| else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT)) |
| nbt_tcp_print(ndo, bp, length); |
| else if (IS_SRC_OR_DST_PORT(SMB_PORT)) |
| smb_tcp_print(ndo, bp, length); |
| #endif |
| else if (IS_SRC_OR_DST_PORT(BEEP_PORT)) |
| beep_print(ndo, bp, length); |
| else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA)) |
| openflow_print(ndo, bp, length); |
| else if (IS_SRC_OR_DST_PORT(FTP_PORT)) { |
| ND_PRINT(": "); |
| ftp_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) { |
| ND_PRINT(": "); |
| http_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) { |
| ND_PRINT(": "); |
| rtsp_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(NAMESERVER_PORT)) { |
| /* over_tcp: TRUE, is_mdns: FALSE */ |
| domain_print(ndo, bp, length, TRUE, FALSE); |
| } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) { |
| msdp_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) { |
| rpki_rtr_print(ndo, bp, length); |
| } else if (IS_SRC_OR_DST_PORT(LDP_PORT)) { |
| ldp_print(ndo, bp, length); |
| } else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) && |
| length >= 4 && ND_TTEST_4(bp)) { |
| /* |
| * 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; |
| const struct sunrpc_msg *rp; |
| enum sunrpc_msg_type direction; |
| |
| fraglen = GET_BE_U_4(bp) & 0x7FFFFFFF; |
| if (fraglen > (length) - 4) |
| fraglen = (length) - 4; |
| rp = (const struct sunrpc_msg *)(bp + 4); |
| if (ND_TTEST_4(rp->rm_direction)) { |
| direction = (enum sunrpc_msg_type) GET_BE_U_4(rp->rm_direction); |
| if (dport == NFS_PORT && direction == SUNRPC_CALL) { |
| ND_PRINT(": NFS request xid %u ", |
| GET_BE_U_4(rp->rm_xid)); |
| nfsreq_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); |
| return; |
| } |
| if (sport == NFS_PORT && direction == SUNRPC_REPLY) { |
| ND_PRINT(": NFS reply xid %u ", |
| GET_BE_U_4(rp->rm_xid)); |
| nfsreply_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); |
| return; |
| } |
| } |
| } |
| |
| return; |
| bad: |
| ND_PRINT("[bad opt]"); |
| if (ch != '\0') |
| ND_PRINT("]"); |
| return; |
| trunc: |
| nd_print_trunc(ndo); |
| if (ch != '\0') |
| ND_PRINT(">"); |
| } |
| |
| /* |
| * RFC1122 says the following on data in RST segments: |
| * |
| * 4.2.2.12 RST Segment: RFC-793 Section 3.4 |
| * |
| * A TCP SHOULD allow a received RST segment to include data. |
| * |
| * DISCUSSION |
| * It has been suggested that a RST segment could contain |
| * ASCII text that encoded and explained the cause of the |
| * RST. No standard has yet been established for such |
| * data. |
| * |
| */ |
| |
| static void |
| print_tcp_rst_data(netdissect_options *ndo, |
| const u_char *sp, u_int length) |
| { |
| u_char c; |
| |
| ND_PRINT(ND_TTEST_LEN(sp, length) ? " [RST" : " [!RST"); |
| if (length > MAX_RST_DATA_LEN) { |
| length = MAX_RST_DATA_LEN; /* can use -X for longer */ |
| ND_PRINT("+"); /* indicate we truncate */ |
| } |
| ND_PRINT(" "); |
| while (length && sp < ndo->ndo_snapend) { |
| c = GET_U_1(sp); |
| sp++; |
| fn_print_char(ndo, c); |
| length--; |
| } |
| ND_PRINT("]"); |
| } |
| |
| static void |
| print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp, |
| u_int datalen, int exp) |
| { |
| u_int i; |
| |
| if (exp) |
| ND_PRINT("tfo"); |
| |
| if (datalen == 0) { |
| /* Fast Open Cookie Request */ |
| ND_PRINT(" cookiereq"); |
| } else { |
| /* Fast Open Cookie */ |
| if (datalen % 2 != 0 || datalen < 4 || datalen > 16) { |
| nd_print_invalid(ndo); |
| } else { |
| ND_PRINT(" cookie "); |
| for (i = 0; i < datalen; ++i) |
| ND_PRINT("%02x", GET_U_1(cp + i)); |
| } |
| } |
| } |
| |
| #ifdef HAVE_LIBCRYPTO |
| DIAG_OFF_DEPRECATION |
| static int |
| tcp_verify_signature(netdissect_options *ndo, |
| const struct ip *ip, const struct tcphdr *tp, |
| const u_char *data, u_int length, const u_char *rcvsig) |
| { |
| struct tcphdr tp1; |
| u_char sig[TCP_SIGLEN]; |
| char zero_proto = 0; |
| MD5_CTX ctx; |
| uint16_t savecsum, tlen; |
| const struct ip6_hdr *ip6; |
| uint32_t len32; |
| uint8_t nxt; |
| |
| if (data + length > ndo->ndo_snapend) { |
| ND_PRINT("snaplen too short, "); |
| return (CANT_CHECK_SIGNATURE); |
| } |
| |
| tp1 = *tp; |
| |
| if (ndo->ndo_sigsecret == NULL) { |
| ND_PRINT("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, (const char *)&ip->ip_src, sizeof(ip->ip_src)); |
| MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst)); |
| MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto)); |
| MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p)); |
| tlen = GET_BE_U_2(ip->ip_len) - IP_HL(ip) * 4; |
| tlen = htons(tlen); |
| MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen)); |
| } else if (IP_V(ip) == 6) { |
| ip6 = (const struct ip6_hdr *)ip; |
| MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); |
| MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); |
| len32 = htonl(GET_BE_U_2(ip6->ip6_plen)); |
| MD5_Update(&ctx, (const char *)&len32, sizeof(len32)); |
| nxt = 0; |
| MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); |
| MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); |
| MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); |
| nxt = IPPROTO_TCP; |
| MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); |
| } else { |
| ND_PRINT("IP version not 4 or 6, "); |
| return (CANT_CHECK_SIGNATURE); |
| } |
| |
| /* |
| * Step 2: Update MD5 hash with TCP header, excluding options. |
| * The TCP checksum must be set to zero. |
| */ |
| memcpy(&savecsum, tp1.th_sum, sizeof(savecsum)); |
| memset(tp1.th_sum, 0, sizeof(tp1.th_sum)); |
| MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr)); |
| memcpy(tp1.th_sum, &savecsum, sizeof(tp1.th_sum)); |
| /* |
| * 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); |
| } |
| DIAG_ON_DEPRECATION |
| #endif /* HAVE_LIBCRYPTO */ |
