905 lines
35 KiB
C
905 lines
35 KiB
C
/* packet-udp.c
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* Routines for UDP/UDPLite packet disassembly
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* Richard Sharpe, 13-Feb-1999, added dispatch table support and
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* support for tftp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#define NEW_PROTO_TREE_API
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#include "config.h"
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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#include <epan/wmem/wmem.h>
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#include <epan/addr_resolv.h>
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#include <epan/ipproto.h>
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#include <epan/in_cksum.h>
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#include <epan/prefs.h>
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#include <epan/expert.h>
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#include "packet-udp.h"
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#include "packet-ip.h"
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#include <epan/conversation.h>
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#include <epan/tap.h>
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#include <epan/decode_as.h>
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void proto_register_udp(void);
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void proto_reg_handoff_udp(void);
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static dissector_handle_t udp_handle;
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static dissector_handle_t udplite_handle;
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static int udp_tap = -1;
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static int udp_follow_tap = -1;
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static header_field_info *hfi_udp = NULL;
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static header_field_info *hfi_udplite = NULL;
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#define UDP_HFI_INIT HFI_INIT(proto_udp)
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#define UDPLITE_HFI_INIT HFI_INIT(proto_udplite)
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static header_field_info hfi_udp_srcport UDP_HFI_INIT =
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{ "Source Port", "udp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udp_dstport UDP_HFI_INIT =
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{ "Destination Port", "udp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udp_port UDP_HFI_INIT =
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{ "Source or Destination Port", "udp.port", FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udp_stream UDP_HFI_INIT =
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{ "Stream index", "udp.stream", FT_UINT32, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udp_length UDP_HFI_INIT =
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{ "Length", "udp.length", FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udp_checksum UDP_HFI_INIT =
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{ "Checksum", "udp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
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"Details at: http://www.wireshark.org/docs/wsug_html_chunked/ChAdvChecksums.html", HFILL };
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static header_field_info hfi_udp_checksum_good UDP_HFI_INIT =
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{ "Good Checksum", "udp.checksum_good", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
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"True: checksum matches packet content; False: doesn't match content or not checked", HFILL };
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static header_field_info hfi_udp_checksum_bad UDP_HFI_INIT =
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{ "Bad Checksum", "udp.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
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"True: checksum doesn't match packet content; False: matches content or not checked", HFILL };
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static header_field_info hfi_udp_proc_src_uid UDP_HFI_INIT =
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{ "Source process user ID", "udp.proc.srcuid", FT_UINT32, BASE_DEC, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_src_pid UDP_HFI_INIT =
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{ "Source process ID", "udp.proc.srcpid", FT_UINT32, BASE_DEC, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_src_uname UDP_HFI_INIT =
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{ "Source process user name", "udp.proc.srcuname", FT_STRING, BASE_NONE, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_src_cmd UDP_HFI_INIT =
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{ "Source process name", "udp.proc.srccmd", FT_STRING, BASE_NONE, NULL, 0x0,
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"Source process command name", HFILL};
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static header_field_info hfi_udp_proc_dst_uid UDP_HFI_INIT =
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{ "Destination process user ID", "udp.proc.dstuid", FT_UINT32, BASE_DEC, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_dst_pid UDP_HFI_INIT =
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{ "Destination process ID", "udp.proc.dstpid", FT_UINT32, BASE_DEC, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_dst_uname UDP_HFI_INIT =
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{ "Destination process user name", "udp.proc.dstuname", FT_STRING, BASE_NONE, NULL, 0x0,
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NULL, HFILL};
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static header_field_info hfi_udp_proc_dst_cmd UDP_HFI_INIT =
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{ "Destination process name", "udp.proc.dstcmd", FT_STRING, BASE_NONE, NULL, 0x0,
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"Destination process command name", HFILL};
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static header_field_info hfi_udplite_checksum_coverage UDPLITE_HFI_INIT =
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{ "Checksum coverage", "udp.checksum_coverage", FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL };
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static header_field_info hfi_udplite_checksum_coverage_bad UDPLITE_HFI_INIT =
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{ "Bad Checksum coverage", "udp.checksum_coverage_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
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NULL, HFILL };
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static gint ett_udp = -1;
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static gint ett_udp_checksum = -1;
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static gint ett_udp_process_info = -1;
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static expert_field ei_udp_possible_traceroute = EI_INIT;
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static expert_field ei_udp_length = EI_INIT;
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static expert_field ei_udplite_checksum_coverage = EI_INIT;
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static expert_field ei_udp_checksum_zero = EI_INIT;
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static expert_field ei_udp_checksum_bad = EI_INIT;
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/* Preferences */
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/* Place UDP summary in proto tree */
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static gboolean udp_summary_in_tree = TRUE;
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/* Check UDP checksums */
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static gboolean udp_check_checksum = FALSE;
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/* Collect IPFIX process flow information */
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static gboolean udp_process_info = FALSE;
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/* Ignore an invalid checksum coverage field for UDPLite */
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static gboolean udplite_ignore_checksum_coverage = TRUE;
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/* Check UDPLite checksums */
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static gboolean udplite_check_checksum = FALSE;
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static dissector_table_t udp_dissector_table;
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static heur_dissector_list_t heur_subdissector_list;
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static dissector_handle_t data_handle;
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static guint32 udp_stream_count;
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/* Determine if there is a sub-dissector and call it. This has been */
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/* separated into a stand alone routine so other protocol dissectors */
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/* can call to it, ie. socks */
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static gboolean try_heuristic_first = FALSE;
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/* Per-packet-info for UDP */
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typedef struct
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{
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gboolean found_heuristic;
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} udp_p_info_t;
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/* XXX - redefined here to not create UI dependencies */
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#define UTF8_LEFTWARDS_ARROW "\xe2\x86\x90" /* 8592 / 0x2190 */
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#define UTF8_RIGHTWARDS_ARROW "\xe2\x86\x92" /* 8594 / 0x2192 */
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#define UTF8_LEFT_RIGHT_ARROW "\xe2\x86\x94" /* 8596 / 0x2194 */
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static void udp_src_prompt(packet_info *pinfo, gchar* result)
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{
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g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Source (%u%s)", pinfo->srcport, UTF8_RIGHTWARDS_ARROW);
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}
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static gpointer udp_src_value(packet_info *pinfo)
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{
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return GUINT_TO_POINTER(pinfo->srcport);
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}
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static void udp_dst_prompt(packet_info *pinfo, gchar* result)
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{
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g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Destination (%s%u)", UTF8_RIGHTWARDS_ARROW, pinfo->destport);
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}
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static gpointer udp_dst_value(packet_info *pinfo)
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{
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return GUINT_TO_POINTER(pinfo->destport);
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}
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static void udp_both_prompt(packet_info *pinfo, gchar* result)
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{
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g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Both (%u%s%u)", pinfo->srcport,UTF8_LEFT_RIGHT_ARROW, pinfo->destport);
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}
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/* Conversation and process code originally copied from packet-tcp.c */
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static struct udp_analysis *
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init_udp_conversation_data(void)
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{
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struct udp_analysis *udpd;
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/* Initialize the udp protocol data structure to add to the udp conversation */
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udpd = wmem_new0(wmem_file_scope(), struct udp_analysis);
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/*
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udpd->flow1.username = NULL;
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udpd->flow1.command = NULL;
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udpd->flow2.username = NULL;
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udpd->flow2.command = NULL;
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*/
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udpd->stream = udp_stream_count++;
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return udpd;
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}
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static struct udp_analysis *
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get_udp_conversation_data(conversation_t *conv, packet_info *pinfo)
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{
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int direction;
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struct udp_analysis *udpd=NULL;
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/* Did the caller supply the conversation pointer? */
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if (conv == NULL)
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conv = find_or_create_conversation(pinfo);
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/* Get the data for this conversation */
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udpd=(struct udp_analysis *)conversation_get_proto_data(conv, hfi_udp->id);
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/* If the conversation was just created or it matched a
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* conversation with template options, udpd will not
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* have been initialized. So, initialize
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* a new udpd structure for the conversation.
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*/
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if (!udpd) {
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udpd = init_udp_conversation_data();
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conversation_add_proto_data(conv, hfi_udp->id, udpd);
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}
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if (!udpd) {
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return NULL;
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}
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/* check direction and get ua lists */
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direction=CMP_ADDRESS(&pinfo->src, &pinfo->dst);
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/* if the addresses are equal, match the ports instead */
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if (direction == 0) {
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direction= (pinfo->srcport > pinfo->destport) ? 1 : -1;
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}
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if (direction >= 0) {
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udpd->fwd=&(udpd->flow1);
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udpd->rev=&(udpd->flow2);
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} else {
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udpd->fwd=&(udpd->flow2);
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udpd->rev=&(udpd->flow1);
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}
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return udpd;
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}
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/* Attach process info to a flow */
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/* XXX - We depend on the UDP dissector finding the conversation first */
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void
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add_udp_process_info(guint32 frame_num, address *local_addr, address *remote_addr, guint16 local_port, guint16 remote_port, guint32 uid, guint32 pid, gchar *username, gchar *command) {
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conversation_t *conv;
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struct udp_analysis *udpd;
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udp_flow_t *flow = NULL;
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if (!udp_process_info) {
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return;
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}
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conv = find_conversation(frame_num, local_addr, remote_addr, PT_UDP, local_port, remote_port, 0);
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if (!conv) {
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return;
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}
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udpd = (struct udp_analysis *)conversation_get_proto_data(conv, hfi_udp->id);
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if (!udpd) {
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return;
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}
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if ((CMP_ADDRESS(local_addr, &conv->key_ptr->addr1) == 0) && (local_port == conv->key_ptr->port1)) {
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flow = &udpd->flow1;
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} else if ((CMP_ADDRESS(remote_addr, &conv->key_ptr->addr1) == 0) && (remote_port == conv->key_ptr->port1)) {
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flow = &udpd->flow2;
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}
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if (!flow || flow->command) {
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return;
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}
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flow->process_uid = uid;
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flow->process_pid = pid;
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flow->username = wmem_strdup(wmem_file_scope(), username);
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flow->command = wmem_strdup(wmem_file_scope(), command);
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}
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/* Return the current stream count */
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guint32 get_udp_stream_count(void)
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{
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return udp_stream_count;
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}
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void
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decode_udp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo,
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proto_tree *tree, int uh_sport, int uh_dport, int uh_ulen)
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{
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tvbuff_t *next_tvb;
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int low_port, high_port;
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gint len, reported_len;
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udp_p_info_t *udp_p_info = NULL;
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gboolean prev_heur_found = FALSE;
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if (pinfo->fd->flags.visited) {
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udp_p_info = (udp_p_info_t*)p_get_proto_data(wmem_file_scope(), pinfo, hfi_udp->id, pinfo->curr_layer_num);
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if (udp_p_info) {
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prev_heur_found = udp_p_info->found_heuristic;
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}
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}else{
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/* Force heuristic check on first pass */
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prev_heur_found = TRUE;
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}
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len = tvb_length_remaining(tvb, offset);
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reported_len = tvb_reported_length_remaining(tvb, offset);
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if (uh_ulen != -1) {
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/* This is the length from the UDP header; the payload should be cut
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off at that length. (If our caller passed a value here, they
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are assumed to have checked that it's >= 8, and hence >= offset.)
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XXX - what if it's *greater* than the reported length? */
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if ((uh_ulen - offset) < reported_len)
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reported_len = uh_ulen - offset;
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if (len > reported_len)
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len = reported_len;
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}
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next_tvb = tvb_new_subset(tvb, offset, len, reported_len);
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/* If the user has a "Follow UDP Stream" window loading, pass a pointer
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* to the payload tvb through the tap system. */
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if (have_tap_listener(udp_follow_tap))
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tap_queue_packet(udp_follow_tap, pinfo, next_tvb);
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/* determine if this packet is part of a conversation and call dissector */
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/* for the conversation if available */
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if (try_conversation_dissector(&pinfo->dst, &pinfo->src, PT_UDP,
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uh_dport, uh_sport, next_tvb, pinfo, tree, NULL)) {
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return;
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}
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if (try_heuristic_first && prev_heur_found) {
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/* Do lookup with the heuristic subdissector table */
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/* Save curr_layer_num as it might be changed by subdissector */
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guint8 curr_layer_num = pinfo->curr_layer_num;
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if (dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree, NULL)) {
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if (!udp_p_info) {
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udp_p_info = wmem_new0(wmem_file_scope(), udp_p_info_t);
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udp_p_info->found_heuristic = TRUE;
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p_add_proto_data(wmem_file_scope(), pinfo, hfi_udp->id, curr_layer_num, udp_p_info);
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}
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return;
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}
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}
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/* Do lookups with the subdissector table.
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We try the port number with the lower value first, followed by the
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port number with the higher value. This means that, for packets
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where a dissector is registered for *both* port numbers:
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1) we pick the same dissector for traffic going in both directions;
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2) we prefer the port number that's more likely to be the right
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one (as that prefers well-known ports to reserved ports);
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although there is, of course, no guarantee that any such strategy
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will always pick the right port number.
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XXX - we ignore port numbers of 0, as some dissectors use a port
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number of 0 to disable the port, and as RFC 768 says that the source
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port in UDP datagrams is optional and is 0 if not used. */
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if (uh_sport > uh_dport) {
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low_port = uh_dport;
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high_port = uh_sport;
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} else {
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low_port = uh_sport;
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high_port = uh_dport;
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}
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if ((low_port != 0) &&
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dissector_try_uint(udp_dissector_table, low_port, next_tvb, pinfo, tree))
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return;
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if ((high_port != 0) &&
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dissector_try_uint(udp_dissector_table, high_port, next_tvb, pinfo, tree))
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return;
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if (!try_heuristic_first && prev_heur_found) {
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/* Do lookup with the heuristic subdissector table */
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/* Save curr_layer_num as it might be changed by subdissector */
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guint8 curr_layer_num = pinfo->curr_layer_num;
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if (dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree, NULL)) {
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if (!udp_p_info) {
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udp_p_info = wmem_new0(wmem_file_scope(), udp_p_info_t);
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udp_p_info->found_heuristic = TRUE;
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p_add_proto_data(wmem_file_scope(), pinfo, hfi_udp->id, curr_layer_num, udp_p_info);
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}
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return;
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}
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}
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call_dissector(data_handle,next_tvb, pinfo, tree);
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}
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static void
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dissect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ip_proto)
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{
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proto_tree *udp_tree = NULL;
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proto_item *ti, *hidden_item, *port_item;
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guint len;
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guint reported_len;
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vec_t cksum_vec[4];
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guint32 phdr[2];
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guint16 computed_cksum;
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int offset = 0;
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e_udphdr *udph;
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proto_tree *checksum_tree;
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proto_item *item;
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conversation_t *conv = NULL;
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struct udp_analysis *udpd = NULL;
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|
proto_tree *process_tree;
|
|
|
|
udph=wmem_new(wmem_packet_scope(), e_udphdr);
|
|
SET_ADDRESS(&udph->ip_src, pinfo->src.type, pinfo->src.len, pinfo->src.data);
|
|
SET_ADDRESS(&udph->ip_dst, pinfo->dst.type, pinfo->dst.len, pinfo->dst.data);
|
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, (ip_proto == IP_PROTO_UDP) ? "UDP" : "UDPlite");
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
udph->uh_sport=tvb_get_ntohs(tvb, offset);
|
|
udph->uh_dport=tvb_get_ntohs(tvb, offset+2);
|
|
|
|
col_add_fstr(pinfo->cinfo, COL_INFO, "Source port: %s Destination port: %s",
|
|
get_udp_port(udph->uh_sport), get_udp_port(udph->uh_dport));
|
|
|
|
if (tree) {
|
|
if (udp_summary_in_tree) {
|
|
if (ip_proto == IP_PROTO_UDP) {
|
|
ti = proto_tree_add_protocol_format(tree, hfi_udp->id, tvb, offset, 8,
|
|
"User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)",
|
|
get_udp_port(udph->uh_sport), udph->uh_sport, get_udp_port(udph->uh_dport), udph->uh_dport);
|
|
} else {
|
|
ti = proto_tree_add_protocol_format(tree, hfi_udplite->id, tvb, offset, 8,
|
|
"Lightweight User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)",
|
|
get_udp_port(udph->uh_sport), udph->uh_sport, get_udp_port(udph->uh_dport), udph->uh_dport);
|
|
}
|
|
} else {
|
|
ti = proto_tree_add_item(tree, (ip_proto == IP_PROTO_UDP) ? hfi_udp : hfi_udplite, tvb, offset, 8, ENC_NA);
|
|
}
|
|
udp_tree = proto_item_add_subtree(ti, ett_udp);
|
|
|
|
port_item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_srcport.id, tvb, offset, 2, udph->uh_sport,
|
|
"%s (%u)", get_udp_port(udph->uh_sport), udph->uh_sport);
|
|
/* The beginning port number, 32768 + 666 (33434), is from LBL's traceroute.c source code and this code
|
|
* further assumes that 3 attempts are made per hop */
|
|
if ((udph->uh_sport > (32768 + 666)) && (udph->uh_sport <= (32768 + 666 + 30)))
|
|
expert_add_info_format(pinfo, port_item, &ei_udp_possible_traceroute, "Possible traceroute: hop #%u, attempt #%u",
|
|
((udph->uh_sport - 32768 - 666 - 1) / 3) + 1,
|
|
((udph->uh_sport - 32768 - 666 - 1) % 3) + 1
|
|
);
|
|
|
|
port_item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_dstport.id, tvb, offset + 2, 2, udph->uh_dport,
|
|
"%s (%u)", get_udp_port(udph->uh_dport), udph->uh_dport);
|
|
if ((udph->uh_dport > (32768 + 666)) && (udph->uh_dport <= (32768 + 666 + 30)))
|
|
expert_add_info_format(pinfo, port_item, &ei_udp_possible_traceroute, "Possible traceroute: hop #%u, attempt #%u",
|
|
((udph->uh_dport - 32768 - 666 - 1) / 3) + 1,
|
|
((udph->uh_dport - 32768 - 666 - 1) % 3) + 1
|
|
);
|
|
|
|
hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_port, tvb, offset, 2, udph->uh_sport);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_port, tvb, offset+2, 2, udph->uh_dport);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
}
|
|
|
|
if (ip_proto == IP_PROTO_UDP) {
|
|
udph->uh_ulen = udph->uh_sum_cov = tvb_get_ntohs(tvb, offset+4);
|
|
if (udph->uh_ulen < 8) {
|
|
/* Bogus length - it includes the header, so it must be >= 8. */
|
|
/* XXX - should handle IPv6 UDP jumbograms (RFC 2675), where the length is zero */
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_length.id, tvb, offset + 4, 2,
|
|
udph->uh_ulen, "%u (bogus, must be >= 8)", udph->uh_ulen);
|
|
expert_add_info_format(pinfo, item, &ei_udp_length, "Bad length value %u < 8", udph->uh_ulen);
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD UDP LENGTH %u < 8]", udph->uh_ulen);
|
|
return;
|
|
}
|
|
if ((udph->uh_ulen > tvb_reported_length(tvb)) && ! pinfo->fragmented && ! pinfo->flags.in_error_pkt) {
|
|
/* Bogus length - it goes past the end of the IP payload */
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_length.id, tvb, offset + 4, 2,
|
|
udph->uh_ulen, "%u (bogus, payload length %u)", udph->uh_ulen, tvb_reported_length(tvb));
|
|
expert_add_info_format(pinfo, item, &ei_udp_length, "Bad length value %u > IP payload length", udph->uh_ulen);
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD UDP LENGTH %u > IP PAYLOAD LENGTH]", udph->uh_ulen);
|
|
} else {
|
|
if (tree) {
|
|
proto_tree_add_uint(udp_tree, &hfi_udp_length, tvb, offset + 4, 2, udph->uh_ulen);
|
|
/* XXX - why is this here, given that this is UDP, not Lightweight UDP? */
|
|
hidden_item = proto_tree_add_uint(udp_tree, &hfi_udplite_checksum_coverage, tvb, offset + 4,
|
|
0, udph->uh_sum_cov);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
}
|
|
}
|
|
} else {
|
|
udph->uh_ulen = tvb_reported_length(tvb);
|
|
udph->uh_sum_cov = tvb_get_ntohs(tvb, offset+4);
|
|
if (((udph->uh_sum_cov > 0) && (udph->uh_sum_cov < 8)) || (udph->uh_sum_cov > udph->uh_ulen)) {
|
|
/* Bogus length - it includes the header, so it must be >= 8, and no larger then the IP payload size. */
|
|
if (tree) {
|
|
hidden_item = proto_tree_add_boolean(udp_tree, &hfi_udplite_checksum_coverage_bad, tvb, offset + 4, 2, TRUE);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_length, tvb, offset + 4, 0, udph->uh_ulen);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
}
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udplite_checksum_coverage.id, tvb, offset + 4, 2,
|
|
udph->uh_sum_cov, "%u (bogus, must be >= 8 and <= %u (ip.len-ip.hdr_len))",
|
|
udph->uh_sum_cov, udph->uh_ulen);
|
|
expert_add_info_format(pinfo, item, &ei_udplite_checksum_coverage, "Bad checksum coverage length value %u < 8 or > %u",
|
|
udph->uh_sum_cov, udph->uh_ulen);
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD LIGHTWEIGHT UDP CHECKSUM COVERAGE LENGTH %u < 8 or > %u]",
|
|
udph->uh_sum_cov, udph->uh_ulen);
|
|
if (!udplite_ignore_checksum_coverage)
|
|
return;
|
|
} else {
|
|
if (tree) {
|
|
hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_length, tvb, offset + 4, 0, udph->uh_ulen);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
proto_tree_add_uint(udp_tree, &hfi_udplite_checksum_coverage, tvb, offset + 4, 2, udph->uh_sum_cov);
|
|
}
|
|
}
|
|
}
|
|
|
|
udph->uh_sum_cov = (udph->uh_sum_cov) ? udph->uh_sum_cov : udph->uh_ulen;
|
|
udph->uh_sum = tvb_get_ntohs(tvb, offset+6);
|
|
reported_len = tvb_reported_length(tvb);
|
|
len = tvb_length(tvb);
|
|
if (udph->uh_sum == 0) {
|
|
/* No checksum supplied in the packet. */
|
|
if ((ip_proto == IP_PROTO_UDP) && (pinfo->src.type == AT_IPv4)) {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb, offset + 6, 2, 0,
|
|
"0x%04x (none)", 0);
|
|
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
} else {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb, offset + 6, 2, 0,
|
|
"0x%04x (Illegal)", 0);
|
|
expert_add_info(pinfo, item, &ei_udp_checksum_zero);
|
|
col_append_str(pinfo->cinfo, COL_INFO, " [ILLEGAL CHECKSUM (0)]");
|
|
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, TRUE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
}
|
|
} else if (!pinfo->fragmented && (len >= reported_len) &&
|
|
(len >= udph->uh_sum_cov) && (reported_len >= udph->uh_sum_cov) &&
|
|
(udph->uh_sum_cov >= 8)) {
|
|
/* 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? */
|
|
|
|
if (((ip_proto == IP_PROTO_UDP) && udp_check_checksum) ||
|
|
((ip_proto == IP_PROTO_UDPLITE) && udplite_check_checksum)) {
|
|
/* Set up the fields of the pseudo-header. */
|
|
cksum_vec[0].ptr = (const guint8 *)pinfo->src.data;
|
|
cksum_vec[0].len = pinfo->src.len;
|
|
cksum_vec[1].ptr = (const guint8 *)pinfo->dst.data;
|
|
cksum_vec[1].len = pinfo->dst.len;
|
|
cksum_vec[2].ptr = (const guint8 *)&phdr;
|
|
switch (pinfo->src.type) {
|
|
|
|
case AT_IPv4:
|
|
if (ip_proto == IP_PROTO_UDP)
|
|
phdr[0] = g_htonl((ip_proto<<16) | udph->uh_ulen);
|
|
else
|
|
phdr[0] = g_htonl((ip_proto<<16) | reported_len);
|
|
cksum_vec[2].len = 4;
|
|
break;
|
|
|
|
case AT_IPv6:
|
|
if (ip_proto == IP_PROTO_UDP)
|
|
phdr[0] = g_htonl(udph->uh_ulen);
|
|
else
|
|
phdr[0] = g_htonl(reported_len);
|
|
phdr[1] = g_htonl(ip_proto);
|
|
cksum_vec[2].len = 8;
|
|
break;
|
|
|
|
default:
|
|
/* UDP runs only atop IPv4 and IPv6.... */
|
|
DISSECTOR_ASSERT_NOT_REACHED();
|
|
break;
|
|
}
|
|
cksum_vec[3].ptr = tvb_get_ptr(tvb, offset, udph->uh_sum_cov);
|
|
cksum_vec[3].len = udph->uh_sum_cov;
|
|
computed_cksum = in_cksum(&cksum_vec[0], 4);
|
|
if (computed_cksum == 0) {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb,
|
|
offset + 6, 2, udph->uh_sum, "0x%04x [correct]", udph->uh_sum);
|
|
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, TRUE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
} else {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb,
|
|
offset + 6, 2, udph->uh_sum,
|
|
"0x%04x [incorrect, should be 0x%04x (maybe caused by \"UDP checksum offload\"?)]", udph->uh_sum,
|
|
in_cksum_shouldbe(udph->uh_sum, computed_cksum));
|
|
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, TRUE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
expert_add_info(pinfo, item, &ei_udp_checksum_bad);
|
|
|
|
col_append_str(pinfo->cinfo, COL_INFO, " [UDP CHECKSUM INCORRECT]");
|
|
}
|
|
} else {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb,
|
|
offset + 6, 2, udph->uh_sum, "0x%04x [validation disabled]", udph->uh_sum);
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
}
|
|
} else {
|
|
item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_checksum.id, tvb,
|
|
offset + 6, 2, udph->uh_sum, "0x%04x [unchecked, not all data available]", udph->uh_sum);
|
|
|
|
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_good, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_boolean(checksum_tree, &hfi_udp_checksum_bad, tvb,
|
|
offset + 6, 2, FALSE);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
}
|
|
|
|
/* Skip over header */
|
|
offset += 8;
|
|
|
|
pinfo->ptype = PT_UDP;
|
|
pinfo->srcport = udph->uh_sport;
|
|
pinfo->destport = udph->uh_dport;
|
|
|
|
tap_queue_packet(udp_tap, pinfo, udph);
|
|
|
|
/* find(or create if needed) the conversation for this udp session */
|
|
conv=find_or_create_conversation(pinfo);
|
|
udpd=get_udp_conversation_data(conv,pinfo);
|
|
|
|
|
|
if (udpd) {
|
|
item = proto_tree_add_uint(udp_tree, &hfi_udp_stream, tvb, offset, 0, udpd->stream);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
|
|
/* Copy the stream index into the header as well to make it available
|
|
* to tap listeners.
|
|
*/
|
|
udph->uh_stream = udpd->stream;
|
|
}
|
|
|
|
if (udpd && ((udpd->fwd && udpd->fwd->command) || (udpd->rev && udpd->rev->command))) {
|
|
ti = proto_tree_add_text(udp_tree, tvb, offset, 0, "Process Information");
|
|
PROTO_ITEM_SET_GENERATED(ti);
|
|
process_tree = proto_item_add_subtree(ti, ett_udp_process_info);
|
|
if (udpd->fwd && udpd->fwd->command) {
|
|
proto_tree_add_uint_format_value(process_tree, hfi_udp_proc_dst_uid.id, tvb, 0, 0,
|
|
udpd->fwd->process_uid, "%u", udpd->fwd->process_uid);
|
|
proto_tree_add_uint_format_value(process_tree, hfi_udp_proc_dst_pid.id, tvb, 0, 0,
|
|
udpd->fwd->process_pid, "%u", udpd->fwd->process_pid);
|
|
proto_tree_add_string_format_value(process_tree, hfi_udp_proc_dst_uname.id, tvb, 0, 0,
|
|
udpd->fwd->username, "%s", udpd->fwd->username);
|
|
proto_tree_add_string_format_value(process_tree, hfi_udp_proc_dst_cmd.id, tvb, 0, 0,
|
|
udpd->fwd->command, "%s", udpd->fwd->command);
|
|
}
|
|
if (udpd->rev->command) {
|
|
proto_tree_add_uint_format_value(process_tree, hfi_udp_proc_src_uid.id, tvb, 0, 0,
|
|
udpd->rev->process_uid, "%u", udpd->rev->process_uid);
|
|
proto_tree_add_uint_format_value(process_tree, hfi_udp_proc_src_pid.id, tvb, 0, 0,
|
|
udpd->rev->process_pid, "%u", udpd->rev->process_pid);
|
|
proto_tree_add_string_format_value(process_tree, hfi_udp_proc_src_uname.id, tvb, 0, 0,
|
|
udpd->rev->username, "%s", udpd->rev->username);
|
|
proto_tree_add_string_format_value(process_tree, hfi_udp_proc_src_cmd.id, tvb, 0, 0,
|
|
udpd->rev->command, "%s", udpd->rev->command);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Call sub-dissectors.
|
|
*
|
|
* XXX - should we do this if this is included in an error packet?
|
|
* It might be nice to see the details of the packet that caused the
|
|
* ICMP error, but it might not be nice to have the dissector update
|
|
* state based on it.
|
|
* Also, we probably don't want to run UDP taps on those packets.
|
|
*
|
|
* We definitely don't want to do it for an error packet if there's
|
|
* nothing left in the packet.
|
|
*/
|
|
if (!pinfo->flags.in_error_pkt || (tvb_length_remaining(tvb, offset) > 0))
|
|
decode_udp_ports(tvb, offset, pinfo, tree, udph->uh_sport, udph->uh_dport,
|
|
udph->uh_ulen);
|
|
}
|
|
|
|
static void
|
|
dissect_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
dissect(tvb, pinfo, tree, IP_PROTO_UDP);
|
|
}
|
|
|
|
static void
|
|
dissect_udplite(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
dissect(tvb, pinfo, tree, IP_PROTO_UDPLITE);
|
|
}
|
|
|
|
static void
|
|
udp_init(void)
|
|
{
|
|
udp_stream_count = 0;
|
|
}
|
|
|
|
void
|
|
proto_register_udp(void)
|
|
{
|
|
module_t *udp_module;
|
|
module_t *udplite_module;
|
|
expert_module_t* expert_udp;
|
|
|
|
#ifndef HAVE_HFI_SECTION_INIT
|
|
static header_field_info *hfi[] = {
|
|
&hfi_udp_srcport,
|
|
&hfi_udp_dstport,
|
|
&hfi_udp_port,
|
|
&hfi_udp_stream,
|
|
&hfi_udp_length,
|
|
&hfi_udp_checksum,
|
|
&hfi_udp_checksum_good,
|
|
&hfi_udp_checksum_bad,
|
|
&hfi_udp_proc_src_uid,
|
|
&hfi_udp_proc_src_pid,
|
|
&hfi_udp_proc_src_uname,
|
|
&hfi_udp_proc_src_cmd,
|
|
&hfi_udp_proc_dst_uid,
|
|
&hfi_udp_proc_dst_pid,
|
|
&hfi_udp_proc_dst_uname,
|
|
&hfi_udp_proc_dst_cmd,
|
|
};
|
|
|
|
static header_field_info *hfi_lite[] = {
|
|
&hfi_udplite_checksum_coverage_bad,
|
|
&hfi_udplite_checksum_coverage,
|
|
};
|
|
#endif
|
|
|
|
static gint *ett[] = {
|
|
&ett_udp,
|
|
&ett_udp_checksum,
|
|
&ett_udp_process_info
|
|
};
|
|
|
|
static ei_register_info ei[] = {
|
|
{ &ei_udp_possible_traceroute, { "udp.possible_traceroute", PI_SEQUENCE, PI_CHAT, "Possible traceroute", EXPFILL }},
|
|
{ &ei_udp_length, { "udp.length.bad", PI_MALFORMED, PI_ERROR, "Bad length value", EXPFILL }},
|
|
{ &ei_udplite_checksum_coverage, { "udp.checksum_coverage.expert", PI_MALFORMED, PI_ERROR, "Bad checksum coverage length value", EXPFILL }},
|
|
{ &ei_udp_checksum_zero, { "udp.checksum.zero", PI_CHECKSUM, PI_ERROR, "Illegal Checksum value (0)", EXPFILL }},
|
|
{ &ei_udp_checksum_bad, { "udp.checksum_bad.expert", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
|
|
};
|
|
|
|
static build_valid_func udp_da_src_values[1] = {udp_src_value};
|
|
static build_valid_func udp_da_dst_values[1] = {udp_dst_value};
|
|
static build_valid_func udp_da_both_values[2] = {udp_src_value, udp_dst_value};
|
|
static decode_as_value_t udp_da_values[3] = {{udp_src_prompt, 1, udp_da_src_values}, {udp_dst_prompt, 1, udp_da_dst_values}, {udp_both_prompt, 2, udp_da_both_values}};
|
|
static decode_as_t udp_da = {"udp", "Transport", "udp.port", 3, 2, udp_da_values, "UDP", "port(s) as",
|
|
decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
|
|
|
|
int proto_udp, proto_udplite;
|
|
|
|
proto_udp = proto_register_protocol("User Datagram Protocol",
|
|
"UDP", "udp");
|
|
hfi_udp = proto_registrar_get_nth(proto_udp);
|
|
udp_handle = register_dissector("udp", dissect_udp, proto_udp);
|
|
expert_udp = expert_register_protocol(proto_udp);
|
|
proto_register_fields(proto_udp, hfi, array_length(hfi));
|
|
|
|
proto_udplite = proto_register_protocol("Lightweight User Datagram Protocol",
|
|
"UDPlite", "udplite");
|
|
udplite_handle = create_dissector_handle(dissect_udplite, proto_udplite);
|
|
hfi_udplite = proto_registrar_get_nth(proto_udplite);
|
|
proto_register_fields(proto_udplite, hfi_lite, array_length(hfi_lite));
|
|
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
expert_register_field_array(expert_udp, ei, array_length(ei));
|
|
|
|
/* subdissector code */
|
|
udp_dissector_table = register_dissector_table("udp.port",
|
|
"UDP port", FT_UINT16, BASE_DEC);
|
|
register_heur_dissector_list("udp", &heur_subdissector_list);
|
|
register_heur_dissector_list("udplite", &heur_subdissector_list);
|
|
|
|
/* Register configuration preferences */
|
|
udp_module = prefs_register_protocol(proto_udp, NULL);
|
|
prefs_register_bool_preference(udp_module, "summary_in_tree",
|
|
"Show UDP summary in protocol tree",
|
|
"Whether the UDP summary line should be shown in the protocol tree",
|
|
&udp_summary_in_tree);
|
|
prefs_register_bool_preference(udp_module, "try_heuristic_first",
|
|
"Try heuristic sub-dissectors first",
|
|
"Try to decode a packet using an heuristic sub-dissector"
|
|
" before using a sub-dissector registered to a specific port",
|
|
&try_heuristic_first);
|
|
prefs_register_bool_preference(udp_module, "check_checksum",
|
|
"Validate the UDP checksum if possible",
|
|
"Whether to validate the UDP checksum",
|
|
&udp_check_checksum);
|
|
prefs_register_bool_preference(udp_module, "process_info",
|
|
"Collect process flow information",
|
|
"Collect process flow information from IPFIX",
|
|
&udp_process_info);
|
|
|
|
udplite_module = prefs_register_protocol(proto_udplite, NULL);
|
|
prefs_register_bool_preference(udplite_module, "ignore_checksum_coverage",
|
|
"Ignore UDPlite checksum coverage",
|
|
"Ignore an invalid checksum coverage field and continue dissection",
|
|
&udplite_ignore_checksum_coverage);
|
|
prefs_register_bool_preference(udplite_module, "check_checksum",
|
|
"Validate the UDPlite checksum if possible",
|
|
"Whether to validate the UDPlite checksum",
|
|
&udplite_check_checksum);
|
|
|
|
register_decode_as(&udp_da);
|
|
|
|
register_init_routine(udp_init);
|
|
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_udp(void)
|
|
{
|
|
dissector_add_uint("ip.proto", IP_PROTO_UDP, udp_handle);
|
|
dissector_add_uint("ip.proto", IP_PROTO_UDPLITE, udplite_handle);
|
|
data_handle = find_dissector("data");
|
|
udp_tap = register_tap("udp");
|
|
udp_follow_tap = register_tap("udp_follow");
|
|
}
|
|
|
|
/*
|
|
* Editor modelines - http://www.wireshark.org/tools/modelines.html
|
|
*
|
|
* Local variables:
|
|
* c-basic-offset: 2
|
|
* tab-width: 8
|
|
* indent-tabs-mode: nil
|
|
* End:
|
|
*
|
|
* vi: set shiftwidth=2 tabstop=8 expandtab:
|
|
* :indentSize=2:tabSize=8:noTabs=true:
|
|
*/
|