/* packet-tcp.c * Routines for TCP packet disassembly * * $Id: packet-tcp.c,v 1.106 2001/09/03 17:57:17 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #ifdef HAVE_SYS_TYPES_H # include #endif #ifdef HAVE_NETINET_IN_H # include #endif #include #include #include #include "in_cksum.h" #ifdef NEED_SNPRINTF_H # include "snprintf.h" #endif #include "resolv.h" #include "ipproto.h" #include "follow.h" #include "prefs.h" #include "packet-tcp.h" #include "packet-ip.h" #include "conversation.h" #include "strutil.h" /* Place TCP summary in proto tree */ static gboolean tcp_summary_in_tree = TRUE; extern FILE* data_out_file; guint16 tcp_urgent_pointer; static int proto_tcp = -1; static int hf_tcp_srcport = -1; static int hf_tcp_dstport = -1; static int hf_tcp_port = -1; static int hf_tcp_seq = -1; static int hf_tcp_nxtseq = -1; static int hf_tcp_ack = -1; static int hf_tcp_hdr_len = -1; static int hf_tcp_flags = -1; static int hf_tcp_flags_cwr = -1; static int hf_tcp_flags_ecn = -1; static int hf_tcp_flags_urg = -1; static int hf_tcp_flags_ack = -1; static int hf_tcp_flags_push = -1; static int hf_tcp_flags_reset = -1; static int hf_tcp_flags_syn = -1; static int hf_tcp_flags_fin = -1; static int hf_tcp_window_size = -1; static int hf_tcp_checksum = -1; static int hf_tcp_checksum_bad = -1; static int hf_tcp_urgent_pointer = -1; static gint ett_tcp = -1; static gint ett_tcp_flags = -1; static gint ett_tcp_options = -1; static gint ett_tcp_option_sack = -1; static dissector_table_t subdissector_table; static heur_dissector_list_t heur_subdissector_list; static conv_dissector_list_t conv_subdissector_list; /* TCP structs and definitions */ typedef struct _e_tcphdr { guint16 th_sport; guint16 th_dport; guint32 th_seq; guint32 th_ack; guint8 th_off_x2; /* combines th_off and th_x2 */ guint8 th_flags; #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_PUSH 0x08 #define TH_ACK 0x10 #define TH_URG 0x20 #define TH_ECN 0x40 #define TH_CWR 0x80 guint16 th_win; guint16 th_sum; guint16 th_urp; } e_tcphdr; /* Minimum TCP header length. */ #define TCPH_MIN_LEN 20 /* * TCP option */ #define TCPOPT_NOP 1 /* Padding */ #define TCPOPT_EOL 0 /* End of options */ #define TCPOPT_MSS 2 /* Segment size negotiating */ #define TCPOPT_WINDOW 3 /* Window scaling */ #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ #define TCPOPT_SACK 5 /* SACK Block */ #define TCPOPT_ECHO 6 #define TCPOPT_ECHOREPLY 7 #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ #define TCPOPT_CC 11 #define TCPOPT_CCNEW 12 #define TCPOPT_CCECHO 13 #define TCPOPT_MD5 19 /* RFC2385 */ /* * TCP option lengths */ #define TCPOLEN_MSS 4 #define TCPOLEN_WINDOW 3 #define TCPOLEN_SACK_PERM 2 #define TCPOLEN_SACK_MIN 2 #define TCPOLEN_ECHO 6 #define TCPOLEN_ECHOREPLY 6 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_CC 6 #define TCPOLEN_CCNEW 6 #define TCPOLEN_CCECHO 6 #define TCPOLEN_MD5 18 static void tcp_info_append_uint(frame_data *fd, const char *abbrev, guint32 val) { if (check_col(fd, COL_INFO)) col_append_fstr(fd, COL_INFO, " %s=%u", abbrev, val); } static void dissect_tcpopt_maxseg(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { guint16 mss; mss = tvb_get_ntohs(tvb, offset + 2); proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s: %u bytes", optp->name, mss); tcp_info_append_uint(fd, "MSS", mss); } static void dissect_tcpopt_wscale(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { guint8 ws; ws = tvb_get_guint8(tvb, offset + 2); proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s: %u bytes", optp->name, ws); tcp_info_append_uint(fd, "WS", ws); } static void dissect_tcpopt_sack(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { proto_tree *field_tree = NULL; proto_item *tf; guint leftedge, rightedge; tf = proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s:", optp->name); offset += 2; /* skip past type and length */ optlen -= 2; /* subtract size of type and length */ while (optlen > 0) { if (field_tree == NULL) { /* Haven't yet made a subtree out of this option. Do so. */ field_tree = proto_item_add_subtree(tf, *optp->subtree_index); } if (optlen < 4) { proto_tree_add_text(field_tree, tvb, offset, optlen, "(suboption would go past end of option)"); break; } leftedge = tvb_get_ntohl(tvb, offset); optlen -= 4; if (optlen < 4) { proto_tree_add_text(field_tree, tvb, offset, optlen, "(suboption would go past end of option)"); break; } /* XXX - check whether it goes past end of packet */ rightedge = tvb_get_ntohl(tvb, offset + 4); optlen -= 4; proto_tree_add_text(field_tree, tvb, offset, 8, "left edge = %u, right edge = %u", leftedge, rightedge); tcp_info_append_uint(fd, "SLE", leftedge); tcp_info_append_uint(fd, "SRE", rightedge); offset += 8; } } static void dissect_tcpopt_echo(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { guint32 echo; echo = tvb_get_ntohl(tvb, offset + 2); proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s: %u", optp->name, echo); tcp_info_append_uint(fd, "ECHO", echo); } static void dissect_tcpopt_timestamp(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { guint32 tsv, tser; tsv = tvb_get_ntohl(tvb, offset + 2); tser = tvb_get_ntohl(tvb, offset + 6); proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s: tsval %u, tsecr %u", optp->name, tsv, tser); tcp_info_append_uint(fd, "TSV", tsv); tcp_info_append_uint(fd, "TSER", tser); } static void dissect_tcpopt_cc(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset, guint optlen, frame_data *fd, proto_tree *opt_tree) { guint32 cc; cc = tvb_get_ntohl(tvb, offset + 2); proto_tree_add_text(opt_tree, tvb, offset, optlen, "%s: %u", optp->name, cc); tcp_info_append_uint(fd, "CC", cc); } static const ip_tcp_opt tcpopts[] = { { TCPOPT_EOL, "EOL", NULL, NO_LENGTH, 0, NULL, }, { TCPOPT_NOP, "NOP", NULL, NO_LENGTH, 0, NULL, }, { TCPOPT_MSS, "Maximum segment size", NULL, FIXED_LENGTH, TCPOLEN_MSS, dissect_tcpopt_maxseg }, { TCPOPT_WINDOW, "Window scale", NULL, FIXED_LENGTH, TCPOLEN_WINDOW, dissect_tcpopt_wscale }, { TCPOPT_SACK_PERM, "SACK permitted", NULL, FIXED_LENGTH, TCPOLEN_SACK_PERM, NULL, }, { TCPOPT_SACK, "SACK", &ett_tcp_option_sack, VARIABLE_LENGTH, TCPOLEN_SACK_MIN, dissect_tcpopt_sack }, { TCPOPT_ECHO, "Echo", NULL, FIXED_LENGTH, TCPOLEN_ECHO, dissect_tcpopt_echo }, { TCPOPT_ECHOREPLY, "Echo reply", NULL, FIXED_LENGTH, TCPOLEN_ECHOREPLY, dissect_tcpopt_echo }, { TCPOPT_TIMESTAMP, "Time stamp", NULL, FIXED_LENGTH, TCPOLEN_TIMESTAMP, dissect_tcpopt_timestamp }, { TCPOPT_CC, "CC", NULL, FIXED_LENGTH, TCPOLEN_CC, dissect_tcpopt_cc }, { TCPOPT_CCNEW, "CC.NEW", NULL, FIXED_LENGTH, TCPOPT_CCNEW, dissect_tcpopt_cc }, { TCPOPT_CCECHO, "CC.ECHO", NULL, FIXED_LENGTH, TCPOLEN_CCECHO, dissect_tcpopt_cc }, { TCPOPT_MD5, "TCP MD5 signature", NULL, FIXED_LENGTH, TCPOLEN_MD5, NULL } }; #define N_TCP_OPTS (sizeof tcpopts / sizeof tcpopts[0]) /* TCP flags flag */ static const true_false_string flags_set_truth = { "Set", "Not set" }; /* Determine if there is a sub-dissector and call it. This has been */ /* separated into a stand alone routine to other protocol dissectors */ /* can call to it, ie. socks */ void decode_tcp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, int src_port, int dst_port) { tvbuff_t *next_tvb; next_tvb = tvb_new_subset(tvb, offset, -1, -1); /* determine if this packet is part of a conversation and call dissector */ /* for the conversation if available */ if (try_conversation_dissector(&pinfo->src, &pinfo->dst, PT_TCP, src_port, dst_port, next_tvb, pinfo, tree)) return; /* do lookup with the subdissector table */ if (dissector_try_port(subdissector_table, src_port, next_tvb, pinfo, tree) || dissector_try_port(subdissector_table, dst_port, next_tvb, pinfo, tree)) return; /* do lookup with the heuristic subdissector table */ if (dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree)) return; /* Oh, well, we don't know this; dissect it as data. */ dissect_data(next_tvb, 0, pinfo, tree); } static void dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { e_tcphdr th; proto_tree *tcp_tree = NULL, *field_tree = NULL; proto_item *ti, *tf; int offset = 0; gchar flags[64] = ""; gchar *fstr[] = {"FIN", "SYN", "RST", "PSH", "ACK", "URG", "ECN", "CWR" }; gint fpos = 0, i; guint bpos; guint hlen; guint optlen; guint32 seglen; guint32 nxtseq; guint len; guint reported_len; vec_t cksum_vec[4]; guint32 phdr[2]; guint16 computed_cksum; guint length_remaining; if (check_col(pinfo->fd, COL_PROTOCOL)) col_set_str(pinfo->fd, COL_PROTOCOL, "TCP"); /* Clear out the Info column. */ if (check_col(pinfo->fd, COL_INFO)) col_clear(pinfo->fd, COL_INFO); /* Avoids alignment problems on many architectures. */ tvb_memcpy(tvb, (guint8 *)&th, offset, sizeof(e_tcphdr)); th.th_sport = ntohs(th.th_sport); th.th_dport = ntohs(th.th_dport); th.th_win = ntohs(th.th_win); th.th_sum = ntohs(th.th_sum); th.th_urp = ntohs(th.th_urp); th.th_seq = ntohl(th.th_seq); th.th_ack = ntohl(th.th_ack); /* Export the urgent pointer, for the benefit of protocols such as rlogin. */ tcp_urgent_pointer = th.th_urp; if (check_col(pinfo->fd, COL_INFO) || tree) { for (i = 0; i < 8; i++) { bpos = 1 << i; if (th.th_flags & bpos) { if (fpos) { strcpy(&flags[fpos], ", "); fpos += 2; } strcpy(&flags[fpos], fstr[i]); fpos += 3; } } flags[fpos] = '\0'; } hlen = hi_nibble(th.th_off_x2) * 4; /* TCP header length, in bytes */ reported_len = tvb_reported_length(tvb); len = tvb_length(tvb); /* Compute the length of data in this segment. */ seglen = reported_len - hlen; /* Compute the sequence number of next octet after this segment. */ nxtseq = th.th_seq + seglen; if (hlen < TCPH_MIN_LEN) { if (check_col(pinfo->fd, COL_INFO)) col_add_fstr(pinfo->fd, COL_INFO, "Bogus TCP header length (%u, must be at least %u)", hlen, TCPH_MIN_LEN); ti = proto_tree_add_item(tree, proto_tcp, tvb, offset, hlen, FALSE); tcp_tree = proto_item_add_subtree(ti, ett_tcp); if (tree) { proto_tree_add_uint_format(tcp_tree, hf_tcp_hdr_len, tvb, offset, 1, hlen, "Header length: %u bytes (bogus, must be at least %u)", hlen, TCPH_MIN_LEN); } return; } if (check_col(pinfo->fd, COL_INFO)) { if (th.th_flags & TH_URG) col_append_fstr(pinfo->fd, COL_INFO, "%s > %s [%s] Seq=%u Ack=%u Win=%u Urg=%u Len=%d", get_tcp_port(th.th_sport), get_tcp_port(th.th_dport), flags, th.th_seq, th.th_ack, th.th_win, th.th_urp, seglen); else col_append_fstr(pinfo->fd, COL_INFO, "%s > %s [%s] Seq=%u Ack=%u Win=%u Len=%d", get_tcp_port(th.th_sport), get_tcp_port(th.th_dport), flags, th.th_seq, th.th_ack, th.th_win, seglen); } if (tree) { if (tcp_summary_in_tree && hlen >= TCPH_MIN_LEN) { ti = proto_tree_add_protocol_format(tree, proto_tcp, tvb, offset, hlen, "Transmission Control Protocol, Src Port: %s (%u), Dst Port: %s (%u), Seq: %u, Ack: %u", get_tcp_port(th.th_sport), th.th_sport, get_tcp_port(th.th_dport), th.th_dport, th.th_seq, th.th_ack); } else { ti = proto_tree_add_item(tree, proto_tcp, tvb, offset, hlen, FALSE); } tcp_tree = proto_item_add_subtree(ti, ett_tcp); proto_tree_add_uint_format(tcp_tree, hf_tcp_srcport, tvb, offset, 2, th.th_sport, "Source port: %s (%u)", get_tcp_port(th.th_sport), th.th_sport); proto_tree_add_uint_format(tcp_tree, hf_tcp_dstport, tvb, offset + 2, 2, th.th_dport, "Destination port: %s (%u)", get_tcp_port(th.th_dport), th.th_dport); proto_tree_add_uint_hidden(tcp_tree, hf_tcp_port, tvb, offset, 2, th.th_sport); proto_tree_add_uint_hidden(tcp_tree, hf_tcp_port, tvb, offset + 2, 2, th.th_dport); proto_tree_add_uint(tcp_tree, hf_tcp_seq, tvb, offset + 4, 4, th.th_seq); if (nxtseq != th.th_seq) proto_tree_add_uint(tcp_tree, hf_tcp_nxtseq, tvb, offset, 0, nxtseq); if (th.th_flags & TH_ACK) proto_tree_add_uint(tcp_tree, hf_tcp_ack, tvb, offset + 8, 4, th.th_ack); proto_tree_add_uint_format(tcp_tree, hf_tcp_hdr_len, tvb, offset + 12, 1, hlen, "Header length: %u bytes", hlen); tf = proto_tree_add_uint_format(tcp_tree, hf_tcp_flags, tvb, offset + 13, 1, th.th_flags, "Flags: 0x%04x (%s)", th.th_flags, flags); field_tree = proto_item_add_subtree(tf, ett_tcp_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_cwr, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_ecn, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_urg, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_ack, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_push, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_reset, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_syn, tvb, offset + 13, 1, th.th_flags); proto_tree_add_boolean(field_tree, hf_tcp_flags_fin, tvb, offset + 13, 1, th.th_flags); proto_tree_add_uint(tcp_tree, hf_tcp_window_size, tvb, offset + 14, 2, th.th_win); if (!pinfo->fragmented && len >= reported_len) { /* The packet isn't part of a fragmented datagram and isn't truncated, so we can checksum it. XXX - make a bigger scatter-gather list once we do fragment reassembly? */ /* Set up the fields of the pseudo-header. */ cksum_vec[0].ptr = pinfo->src.data; cksum_vec[0].len = pinfo->src.len; cksum_vec[1].ptr = pinfo->dst.data; cksum_vec[1].len = pinfo->dst.len; cksum_vec[2].ptr = (const guint8 *)&phdr; switch (pinfo->src.type) { case AT_IPv4: phdr[0] = htonl((IP_PROTO_TCP<<16) + reported_len); cksum_vec[2].len = 4; break; case AT_IPv6: phdr[0] = htonl(reported_len); phdr[1] = htonl(IP_PROTO_TCP); cksum_vec[2].len = 8; break; default: /* TCP runs only atop IPv4 and IPv6.... */ g_assert_not_reached(); break; } cksum_vec[3].ptr = tvb_get_ptr(tvb, offset, len); cksum_vec[3].len = reported_len; computed_cksum = in_cksum(&cksum_vec[0], 4); if (computed_cksum == 0) { proto_tree_add_uint_format(tcp_tree, hf_tcp_checksum, tvb, offset + 16, 2, th.th_sum, "Checksum: 0x%04x (correct)", th.th_sum); } else { proto_tree_add_boolean_hidden(tcp_tree, hf_tcp_checksum_bad, tvb, offset + 16, 2, TRUE); proto_tree_add_uint_format(tcp_tree, hf_tcp_checksum, tvb, offset + 16, 2, th.th_sum, "Checksum: 0x%04x (incorrect, should be 0x%04x)", th.th_sum, in_cksum_shouldbe(th.th_sum, computed_cksum)); } } else { proto_tree_add_uint_format(tcp_tree, hf_tcp_checksum, tvb, offset + 16, 2, th.th_sum, "Checksum: 0x%04x", th.th_sum); } if (th.th_flags & TH_URG) proto_tree_add_uint(tcp_tree, hf_tcp_urgent_pointer, tvb, offset + 18, 2, th.th_urp); } /* Decode TCP options, if any. */ if (tree && hlen > sizeof (e_tcphdr)) { /* There's more than just the fixed-length header. Decode the options. */ optlen = hlen - sizeof (e_tcphdr); /* length of options, in bytes */ tf = proto_tree_add_text(tcp_tree, tvb, offset + 20, optlen, "Options: (%d bytes)", optlen); field_tree = proto_item_add_subtree(tf, ett_tcp_options); dissect_ip_tcp_options(tvb, offset + 20, optlen, tcpopts, N_TCP_OPTS, TCPOPT_EOL, pinfo->fd, field_tree); } /* Skip over header + options */ offset += hlen; pinfo->ptype = PT_TCP; pinfo->srcport = th.th_sport; pinfo->destport = th.th_dport; /* Check the packet length to see if there's more data (it could be an ACK-only packet) */ length_remaining = tvb_length_remaining(tvb, offset); if (length_remaining != 0) { if (th.th_flags & TH_RST) { /* * RFC1122 says: * * 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. * * so for segments with RST we just display the data as text. */ proto_tree_add_text(tcp_tree, tvb, offset, length_remaining, "Reset cause: %s", tvb_format_text(tvb, offset, length_remaining)); } else decode_tcp_ports( tvb, offset, pinfo, tree, th.th_sport, th.th_dport); } if( data_out_file ) { reassemble_tcp( th.th_seq, /* sequence number */ seglen, /* data length */ tvb_get_ptr(tvb, offset, length_remaining), /* data */ length_remaining, /* captured data length */ ( th.th_flags & TH_SYN ), /* is syn set? */ &pinfo->net_src, &pinfo->net_dst, pinfo->srcport, pinfo->destport); } } void proto_register_tcp(void) { static hf_register_info hf[] = { { &hf_tcp_srcport, { "Source Port", "tcp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_dstport, { "Destination Port", "tcp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_port, { "Source or Destination Port", "tcp.port", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_seq, { "Sequence number", "tcp.seq", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_nxtseq, { "Next sequence number", "tcp.nxtseq", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_ack, { "Acknowledgement number", "tcp.ack", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_hdr_len, { "Header Length", "tcp.hdr_len", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_flags, { "Flags", "tcp.flags", FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_tcp_flags_cwr, { "Congestion Window Reduced (CWR)", "tcp.flags.cwr", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_CWR, "", HFILL }}, { &hf_tcp_flags_ecn, { "ECN-Echo", "tcp.flags.ecn", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_ECN, "", HFILL }}, { &hf_tcp_flags_urg, { "Urgent", "tcp.flags.urg", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_URG, "", HFILL }}, { &hf_tcp_flags_ack, { "Acknowledgment", "tcp.flags.ack", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_ACK, "", HFILL }}, { &hf_tcp_flags_push, { "Push", "tcp.flags.push", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_PUSH, "", HFILL }}, { &hf_tcp_flags_reset, { "Reset", "tcp.flags.reset", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_RST, "", HFILL }}, { &hf_tcp_flags_syn, { "Syn", "tcp.flags.syn", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_SYN, "", HFILL }}, { &hf_tcp_flags_fin, { "Fin", "tcp.flags.fin", FT_BOOLEAN, 8, TFS(&flags_set_truth), TH_FIN, "", HFILL }}, { &hf_tcp_window_size, { "Window size", "tcp.window_size", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_tcp_checksum, { "Checksum", "tcp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_tcp_checksum_bad, { "Bad Checksum", "tcp.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_tcp_urgent_pointer, { "Urgent pointer", "tcp.urgent_pointer", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, }; static gint *ett[] = { &ett_tcp, &ett_tcp_flags, &ett_tcp_options, &ett_tcp_option_sack, }; module_t *tcp_module; proto_tcp = proto_register_protocol("Transmission Control Protocol", "TCP", "tcp"); proto_register_field_array(proto_tcp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* subdissector code */ subdissector_table = register_dissector_table("tcp.port"); register_heur_dissector_list("tcp", &heur_subdissector_list); register_conv_dissector_list("tcp", &conv_subdissector_list); /* Register configuration preferences */ tcp_module = prefs_register_protocol(proto_tcp, NULL); prefs_register_bool_preference(tcp_module, "tcp_summary_in_tree", "Show TCP summary in protocol tree", "Whether the TCP summary line should be shown in the protocol tree", &tcp_summary_in_tree); } void proto_reg_handoff_tcp(void) { dissector_add("ip.proto", IP_PROTO_TCP, dissect_tcp, proto_tcp); }