forked from osmocom/wireshark
![Dario Lombardo](/assets/img/avatar_default.png)
Change-Id: I92c94448e6641716d03158a5f332c8b53709423a Reviewed-on: https://code.wireshark.org/review/25756 Petri-Dish: Dario Lombardo <lomato@gmail.com> Reviewed-by: Anders Broman <a.broman58@gmail.com>
202 lines
7 KiB
C
202 lines
7 KiB
C
/* packet-jmirror.c
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* Routines for Jmirror protocol packet disassembly
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* By Wayne Brassem <wbrassem@juniper.net>
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* Copyright 2009 Wayne Brassem
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* 2012 Wayne Brassem - Correction to support IPv6 over PPP
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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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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "config.h"
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#include <epan/packet.h>
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void proto_register_jmirror(void);
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void proto_reg_handoff_jmirror(void);
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#define MIRROR_HDR_SZ 8
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#define MIRROR_ID_SZ 4
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#define SESSION_ID_SZ 4
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#define DEF_JMIRROR_UDP_PORT 30030 /* a product of primes (1*2*3*5*7*11*13) :-) Not IANA registered */
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/*
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* See www.juniper.net JUNOSe Packet Mirroring documentation
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*/
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/* Jmirror protocol variables */
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static int proto_jmirror = -1;
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static int hf_jmirror_mid = -1;
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static int hf_jmirror_sid = -1;
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static gint ett_jmirror = -1;
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/* Handles which point to the packet dissectors */
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static dissector_handle_t ipv4_handle;
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static dissector_handle_t ipv6_handle;
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static dissector_handle_t hdlc_handle;
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/* Routine to return the dissector handle based on heuristic packet inspection */
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static dissector_handle_t
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get_heuristic_handle(tvbuff_t *tvb)
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{
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int offset = MIRROR_HDR_SZ; /* Point past the 8 byte mirror header */
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int byte0, byte1, byte2, byte3;
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/* The following section is designed to determine the nature of the mirrored packet.
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*
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* The first four bytes will be inspected to deduce the type of traffic.
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* The bit pattern shown below is the basis. A bit of "x" is a variable field.
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*
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* IPv4 Header: 0100 0101 xxxx xx00 ==> Pattern for standard IPv4 20-byte header
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* IPv6 Header: 0110 xxxx xxxx xxxx xxxx xxxx xxxx xxxx ==> Pattern for standard IPv6 header with variable TC and Flow
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* PPP/HDLC: 1111 1111 0000 0011 xx00 0000 0010 0001 ==> HDLC-like framing for PPP (FF 03 x0 21)
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* PPP/HDLC: 1111 1111 0000 0011 0000 0000 0101 0111 ==> HDLC-like framing for PPP IPv6 (FF 03 00 57)
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*/
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if (!tvb_bytes_exist(tvb, offset, 4))
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return NULL; /* Not enough bytes for heuristic test */
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/* Filter for IPv4 and IPv6 packets */
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byte0 = tvb_get_guint8(tvb, offset + 0);
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byte1 = tvb_get_guint8(tvb, offset + 1);
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byte2 = tvb_get_guint8(tvb, offset + 2);
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byte3 = tvb_get_guint8(tvb, offset + 3);
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/* Look for IPv4 with standard header length */
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if ( byte0 == 0x45 && ipv4_handle )
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return ipv4_handle;
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/* Look for IPv6 */
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else if ( hi_nibble(byte0) == 6 && ipv6_handle )
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return ipv6_handle;
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/* Look for PPP/HDLC for LCP and IPv4 */
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else if ( byte0 == 0xff && byte1 == 0x03 && lo_nibble(byte2) == 0 && byte3 == 0x21 && hdlc_handle )
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return hdlc_handle;
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/* Look for PPP/HDLC for IPv6 */
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else if ( byte0 == 0xff && byte1 == 0x03 && byte2 == 0 && byte3 == 0x57 && hdlc_handle )
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return hdlc_handle;
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/* If it's something else entirely return nothing */
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else
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return NULL;
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}
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/* Heuristic UDP dissector called by Wireshark looking for embedded IPv4, IPv6 or L2TP/HDLC Jmirror packets */
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static int
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dissect_jmirror(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
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{
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int offset = 0;
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dissector_handle_t dissector_handle;
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unsigned int midval, sidval;
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proto_item *ti = NULL;
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proto_tree *jmirror_tree = NULL;
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tvbuff_t *next_tvb = NULL;
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if ( !( dissector_handle = get_heuristic_handle(tvb) ) )
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return 0;
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/* Populate the Protocol field in the Wireshark packet display */
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "Jmirror");
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/* Build the Jmirror Identifier value and store the string in a buffer */
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midval = tvb_get_ntohl(tvb, offset);
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/* Build the Session Identifier value and store the string in a buffer */
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sidval = tvb_get_ntohl(tvb, offset+MIRROR_ID_SZ);
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/* Populate the Info field in the Wireshark packet display */
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col_add_fstr(pinfo->cinfo, COL_INFO, "MID: 0X%08x (%d), SID: 0x%08x (%d)", midval, midval, sidval, sidval);
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/* Create a header for the Mirror Header in the protocol tree */
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ti = proto_tree_add_protocol_format(tree, proto_jmirror, tvb, offset, MIRROR_HDR_SZ,
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"Juniper Packet Mirror, MID: 0x%08x (%d), SID: 0x%08x (%d)", midval, midval, sidval, sidval);
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/* Add the Juniper Packet Mirror to the main protocol tree */
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jmirror_tree = proto_item_add_subtree(ti, ett_jmirror);
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/* Insert the Jmirror Identifier into the protocol tree and assign value to filter variable */
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proto_tree_add_item(jmirror_tree, hf_jmirror_mid, tvb, offset, MIRROR_ID_SZ, ENC_BIG_ENDIAN);
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/* Push the tvbuff_t offset pointer along to the Session Identifier */
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offset += MIRROR_ID_SZ;
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/* Insert the Session Identifier into the protocol tree and assign value to filter variable */
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proto_tree_add_item(jmirror_tree, hf_jmirror_sid, tvb, offset, SESSION_ID_SZ, ENC_BIG_ENDIAN);
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/* Push the tvbuff_t offset pointer along to the start of the mirrored packet */
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offset += SESSION_ID_SZ;
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/* Create a buffer pointer for the next dissector */
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next_tvb = tvb_new_subset_remaining(tvb, offset);
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/* Call the next dissector based on the heuristics and return the number of bytes dissected */
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return MIRROR_HDR_SZ + call_dissector(dissector_handle, next_tvb, pinfo, tree);
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}
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/* Register Jmirror dissector with Wireshark */
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void
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proto_register_jmirror(void)
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{
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/* Used by the Expression dialog and filter box */
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static hf_register_info jmirror_hf[] = {
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{ &hf_jmirror_mid,
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{ "Jmirror Identifier", "jmirror.mid", FT_UINT32, BASE_HEX_DEC, NULL, 0x0,
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"Unique identifier of the mirrored session", HFILL }
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},
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{ &hf_jmirror_sid,
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{ "Session Identifier", "jmirror.sid", FT_UINT32, BASE_HEX_DEC, NULL, 0x0,
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"Unique identifier of the user session", HFILL }
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}
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};
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static gint *jmirror_ett[] = {
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&ett_jmirror
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};
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/* Register the Jmirror protocol with Wireshark */
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proto_jmirror = proto_register_protocol("Juniper Packet Mirror", "Jmirror", "jmirror");
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/* Register the Jmirror subfields for filters */
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proto_register_field_array(proto_jmirror, jmirror_hf, array_length(jmirror_hf));
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proto_register_subtree_array(jmirror_ett, array_length(jmirror_ett));
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}
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/* Create attachment point for dissector in Wireshark */
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void
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proto_reg_handoff_jmirror(void)
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{
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dissector_handle_t jmirror_handle;
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/* register as heuristic dissector for UDP */
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/* heur_dissector_add("udp", dissect_jmirror, proto_jmirror); */
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/* Create a dissector handle for the Jmirror protocol */
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jmirror_handle = create_dissector_handle(dissect_jmirror, proto_jmirror);
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/* Create pointer to ipv4, ipv6, ppp and data dissectors */
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ipv4_handle = find_dissector_add_dependency("ip", proto_jmirror);
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ipv6_handle = find_dissector_add_dependency("ipv6", proto_jmirror);
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hdlc_handle = find_dissector_add_dependency("pw_hdlc_nocw_hdlc_ppp", proto_jmirror);
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/* Register as a normal IP dissector with default UDP port 30030 */
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dissector_add_uint_with_preference("udp.port", DEF_JMIRROR_UDP_PORT, jmirror_handle);
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local variables:
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* c-basic-offset: 8
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* tab-width: 8
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* indent-tabs-mode: t
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* End:
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*
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* vi: set shiftwidth=8 tabstop=8 noexpandtab:
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* :indentSize=8:tabSize=8:noTabs=false:
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*/
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