epan/dissectors/packet-fmtp.c

   1 /* packet-fmtp.c
   2  *
   3  * Routines for FMTP version 2 packet dissection.
   4  *
   5  * The specifications of this public protocol can be found on Eurocontrol web site:
   6  * http://www.eurocontrol.int/sites/default/files/publication/files/20070614-fmtp-spec-v2.0.pdf
   7  *
   8  * Copyright 2011, Christophe Paletou <c.paletou@free.fr>
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * SPDX-License-Identifier: GPL-2.0-or-later
  15  */
  16
  17 #include "config.h"
  18
  19 #include <epan/packet.h>
  20 #include "packet-tcp.h"
  21
  22 void proto_register_fmtp(void);
  23 void proto_reg_handoff_fmtp(void);
  24
  25 static int proto_fmtp;
  26 static int hf_fmtp_pdu_version;
  27 static int hf_fmtp_pdu_reserved;
  28 static int hf_fmtp_pdu_type;
  29 static int hf_fmtp_pdu_length;
  30 static int ett_fmtp;
  31
  32 /* #define TCP_PORT_FMTP       8500 */
  33 #define FMTP_HEADER_LEN     5
  34 #define FMTP_MAX_DATA_LEN   10240
  35 #define FMTP_MAX_LEN        FMTP_HEADER_LEN + FMTP_MAX_DATA_LEN
  36
  37 #define FMTP_TYP_OPERATIONAL    1
  38 #define FMTP_TYP_OPERATOR       2
  39 #define FMTP_TYP_IDENTIFICATION 3
  40 #define FMTP_TYP_SYSTEM         4
  41
  42 #define INFO_STR_SIZE        1024
  43
  44 static const value_string packet_type_names[] = {
  45     { FMTP_TYP_OPERATIONAL,    "Operational message" },
  46     { FMTP_TYP_OPERATOR,       "Operator message" },
  47     { FMTP_TYP_IDENTIFICATION, "Identification message" },
  48     { FMTP_TYP_SYSTEM        , "System message" },
  49     { 0, NULL }
  50 };
  51
  52 static const value_string system_message_names[] = {
  53     { 12337, "Startup" },   /* 0x3031 */
  54     { 12336, "Shutdown" },  /* 0x3030 */
  55     { 12339, "Heartbeat" }, /* 0x3033 */
  56     { 0, NULL }
  57 };
  58
  59 static int
  60 dissect_fmtp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  61 {
  62     uint8_t     packet_type;
  63     uint16_t    packet_len;
  64     tvbuff_t   *next_tvb;
  65     proto_item *ti = NULL;
  66     proto_tree *fmtp_tree = NULL;
  67
  68     packet_type = tvb_get_uint8(tvb, 4);
  69     packet_len  = tvb_get_ntohs(tvb, 2);
  70
  71     col_set_str(pinfo->cinfo, COL_PROTOCOL, "FMTP");
  72
  73     /* Clear out stuff in the info column */
  74     col_clear(pinfo->cinfo, COL_INFO);
  75
  76     ti = proto_tree_add_item(tree, proto_fmtp, tvb, 0, -1, ENC_NA);
  77     proto_item_append_text(ti, ", %s",
  78         val_to_str(packet_type, packet_type_names, "Unknown (0x%02x)"));
  79
  80     switch (packet_type) {
  81
  82         case FMTP_TYP_IDENTIFICATION:
  83             proto_item_append_text(ti, " (%s)",
  84                 tvb_get_string_enc(pinfo->pool, tvb, FMTP_HEADER_LEN, packet_len-FMTP_HEADER_LEN, ENC_ASCII));
  85             col_add_fstr(pinfo->cinfo, COL_INFO, "%s (%s)",
  86                 val_to_str(packet_type, packet_type_names, "Unknown (0x%02x)"),
  87                 tvb_get_string_enc(pinfo->pool, tvb, FMTP_HEADER_LEN, packet_len-FMTP_HEADER_LEN, ENC_ASCII));
  88             break;
  89
  90         case FMTP_TYP_SYSTEM:
  91             proto_item_append_text(ti, " (%s)",
  92                 tvb_get_string_enc(pinfo->pool, tvb, FMTP_HEADER_LEN, packet_len-FMTP_HEADER_LEN, ENC_ASCII));
  93             col_add_fstr(pinfo->cinfo, COL_INFO, "%s (%s)",
  94                 val_to_str(packet_type, packet_type_names, "Unknown (0x%02x)"),
  95                 val_to_str(tvb_get_ntohs(tvb, FMTP_HEADER_LEN), system_message_names, "Unknown (0x%02x)"));
  96             break;
  97
  98         default:
  99             col_add_str(pinfo->cinfo, COL_INFO,
 100                 val_to_str(packet_type, packet_type_names, "Unknown (0x%02x)"));
 101             break;
 102     }
 103     if (tree) { /* we are being asked for details */
 104         fmtp_tree = proto_item_add_subtree(ti, ett_fmtp);
 105         proto_tree_add_item(fmtp_tree, hf_fmtp_pdu_version,  tvb, 0, 1, ENC_BIG_ENDIAN);
 106         proto_tree_add_item(fmtp_tree, hf_fmtp_pdu_reserved, tvb, 1, 1, ENC_BIG_ENDIAN);
 107         proto_tree_add_item(fmtp_tree, hf_fmtp_pdu_length,   tvb, 2, 2, ENC_BIG_ENDIAN);
 108         proto_tree_add_item(fmtp_tree, hf_fmtp_pdu_type,     tvb, 4, 1, ENC_BIG_ENDIAN);
 109
 110         next_tvb = tvb_new_subset_remaining(tvb, FMTP_HEADER_LEN);
 111         call_data_dissector(next_tvb, pinfo, fmtp_tree);
 112     }
 113
 114     return tvb_captured_length(tvb);
 115 }
 116
 117 static unsigned
 118 get_fmtp_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
 119 {
 120     return (unsigned)tvb_get_ntohs(tvb, offset+2);
 121 }
 122
 123 static bool
 124 dissect_fmtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 125 {
 126     uint16_t length;
 127
 128     if (tvb_captured_length(tvb) < 5)
 129         return false;
 130     /*
 131      * Check that packet looks like FMTP before going further
 132      */
 133     /* VERSION must currently be 0x02 */
 134     if (tvb_get_uint8(tvb, 0) != 0x02) return false;
 135     /* RESERVED must currently be 0x00 */
 136     if (tvb_get_uint8(tvb, 1) != 0x00) return false;
 137     length = tvb_get_ntohs(tvb, 2);
 138     /* LENGTH must currently not exceed 5 (header) + 10240 (data) */
 139     if ((length > FMTP_MAX_LEN) || (length < FMTP_HEADER_LEN)) return false;
 140     /* TYP must currently be in range 0x01-0x04 */
 141     if ((tvb_get_uint8(tvb, 4) < 0x01) || (tvb_get_uint8(tvb, 4) > 0x04))
 142         return false;
 143
 144     tcp_dissect_pdus(tvb, pinfo, tree, true, FMTP_HEADER_LEN,
 145                      get_fmtp_message_len, dissect_fmtp_message, data);
 146     return true;
 147 }
 148
 149 void
 150 proto_register_fmtp(void)
 151 {
 152     static hf_register_info hf[] = {
 153         { &hf_fmtp_pdu_version,
 154             { "Version", "fmtp.version",
 155             FT_UINT8, BASE_DEC,
 156             NULL, 0x0,
 157             NULL, HFILL }
 158         },
 159         { &hf_fmtp_pdu_reserved,
 160             { "Reserved", "fmtp.reserved",
 161             FT_UINT8, BASE_DEC,
 162             NULL, 0x0,
 163             NULL, HFILL }
 164         },
 165         { &hf_fmtp_pdu_length,
 166             { "Length", "fmtp.length",
 167             FT_UINT16, BASE_DEC,
 168             NULL, 0x0,
 169             NULL, HFILL }
 170         },
 171         { &hf_fmtp_pdu_type,
 172             { "Type", "fmtp.type",
 173             FT_UINT8, BASE_DEC,
 174             VALS(packet_type_names), 0x0,
 175             NULL, HFILL }
 176         }
 177     };
 178
 179     /* Setup protocol subtree array */
 180     static int *ett[] = {
 181         &ett_fmtp
 182     };
 183
 184     proto_fmtp = proto_register_protocol("Flight Message Transfer Protocol (FMTP)", "FMTP", "fmtp");
 185
 186     proto_register_field_array(proto_fmtp, hf, array_length(hf));
 187     proto_register_subtree_array(ett, array_length(ett));
 188 }
 189
 190 void
 191 proto_reg_handoff_fmtp(void)
 192 {
 193     /* Register as heuristic dissector for TCP */
 194     heur_dissector_add("tcp", dissect_fmtp, "FMTP over TCP", "fmtp_tcp", proto_fmtp, HEURISTIC_ENABLE);
 195 }
 196
 197 /*
 198  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 199  *
 200  * Local variables:
 201  * c-basic-offset: 4
 202  * tab-width: 8
 203  * indent-tabs-mode: nil
 204  * End:
 205  *
 206  * vi: set shiftwidth=4 tabstop=8 expandtab:
 207  * :indentSize=4:tabSize=8:noTabs=true:
 208  */
 209