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/* packet-msnip.c 2001 Ronnie Sahlberg <See AUTHORS for email>
* Routines for IGMP/MSNIP packet disassembly
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
MSNIP
code
0x23 x
0x24 x
0x25 x
MSNIP " Multicast Source Notification of Interest Protocol
Defined in draft-ietf-idmr-igmp-msnip-00.txt
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/to_str.h>
#include "packet-igmp.h"
void proto_register_msnip(void);
void proto_reg_handoff_msnip(void);
static dissector_handle_t msnip_handle;
static int proto_msnip = -1;
static int hf_checksum = -1;
static int hf_checksum_status = -1;
static int hf_type = -1;
static int hf_count = -1;
static int hf_holdtime = -1;
static int hf_groups = -1;
static int hf_maddr = -1;
static int hf_mask = -1;
static int hf_holdtime16 = -1;
static int hf_genid = -1;
static int hf_rec_type = -1;
static int ett_msnip = -1;
static int ett_groups = -1;
static expert_field ei_checksum = EI_INIT;
#define MC_ALL_IGMPV3_ROUTERS 0xe0000016
#define MSNIP_GM 0x23
#define MSNIP_IS 0x24
#define MSNIP_RMR 0x25
static const value_string msnip_types[] = {
{MSNIP_GM, "Multicast Group Map"},
{MSNIP_IS, "Multicast Interest Solicitation"},
{MSNIP_RMR, "Multicast Receiver Membership Report"},
{0, NULL}
};
#define MSNIP_RECTYPE_TRANSMIT 1
#define MSNIP_RECTYPE_HOLD 2
static const value_string msnip_rec_types[] = {
{MSNIP_RECTYPE_TRANSMIT, "Request to start transmitting group"},
{MSNIP_RECTYPE_HOLD, "Request to hold transmitting group"},
{0, NULL}
};
static int
dissect_msnip_rmr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
{
guint8 count;
/* group count */
count = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
offset += 1;
/* checksum */
igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
offset += 2;
while (count--) {
proto_tree *tree;
proto_item *item;
guint8 rec_type;
int old_offset = offset;
item = proto_tree_add_item(parent_tree, hf_groups,
tvb, offset, -1, ENC_NA);
tree = proto_item_add_subtree(item, ett_groups);
/* record type */
rec_type = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(tree, hf_rec_type, tvb, offset, 1, rec_type);
offset += 1;
/* skip 3 unused bytes */
offset += 3;
/* multicast group */
proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
if (item) {
proto_item_set_text(item,"Group: %s %s",
tvb_ip_to_str(pinfo->pool, tvb, offset-4),
val_to_str(rec_type, msnip_rec_types,
"Unknown Type:0x%02x"));
proto_item_set_len(item, offset-old_offset);
}
}
return offset;
}
static int
dissect_msnip_is(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
{
/* skip reserved byte */
offset += 1;
/* checksum */
igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
offset += 2;
/* 16 bit holdtime */
proto_tree_add_item(parent_tree, hf_holdtime16, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
/* Generation ID */
proto_tree_add_item(parent_tree, hf_genid, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
return offset;
}
static int
dissect_msnip_gm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
{
guint8 count;
/* group count */
count = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
offset += 1;
/* checksum */
igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
offset += 2;
/* holdtime */
proto_tree_add_uint(parent_tree, hf_holdtime, tvb, offset, 4, count);
offset += 4;
while (count--) {
proto_tree *tree;
proto_item *item;
guint8 masklen;
int old_offset = offset;
item = proto_tree_add_item(parent_tree, hf_groups,
tvb, offset, -1, ENC_NA);
tree = proto_item_add_subtree(item, ett_groups);
/* multicast group */
proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
/* mask length */
masklen = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(tree, hf_mask, tvb,
offset, 1, masklen);
offset += 1;
/* skip 3 unused bytes */
offset += 3;
if (item) {
proto_item_set_text(item,"Group: %s/%d",
tvb_ip_to_str(pinfo->pool, tvb, offset - 8), masklen);
proto_item_set_len(item, offset-old_offset);
}
}
return offset;
}
/* This function is only called from the IGMP dissector */
static int
dissect_msnip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void* data _U_)
{
proto_tree *tree;
proto_item *item;
guint8 type;
int offset = 0;
guint32 dst = g_htonl(MC_ALL_IGMPV3_ROUTERS);
/* Shouldn't be destined for us */
if ((pinfo->dst.type != AT_IPv4) || memcmp(pinfo->dst.data, &dst, 4))
return 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MSNIP");
col_clear(pinfo->cinfo, COL_INFO);
item = proto_tree_add_item(parent_tree, proto_msnip, tvb, offset, -1, ENC_NA);
tree = proto_item_add_subtree(item, ett_msnip);
type = tvb_get_guint8(tvb, offset);
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str(type, msnip_types,
"Unknown Type:0x%02x"));
/* type of command */
proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
offset += 1;
switch (type) {
case MSNIP_GM:
offset = dissect_msnip_gm(tvb, pinfo, tree, offset);
break;
case MSNIP_IS:
offset = dissect_msnip_is(tvb, pinfo, tree, offset);
break;
case MSNIP_RMR:
offset = dissect_msnip_rmr(tvb, pinfo, tree, offset);
break;
}
if (item) {
proto_item_set_len(item, offset);
}
return offset;
}
void
proto_register_msnip(void)
{
static hf_register_info hf[] = {
{ &hf_type,
{ "Type", "msnip.type", FT_UINT8, BASE_HEX,
VALS(msnip_types), 0, "MSNIP Packet Type", HFILL }},
{ &hf_checksum,
{ "Checksum", "msnip.checksum", FT_UINT16, BASE_HEX,
NULL, 0, "MSNIP Checksum", HFILL }},
{ &hf_checksum_status,
{ "Checksum Status", "msnip.checksum.status", FT_UINT8, BASE_NONE,
VALS(proto_checksum_vals), 0x0, NULL, HFILL }},
{ &hf_count,
{ "Count", "msnip.count", FT_UINT8, BASE_DEC,
NULL, 0, "MSNIP Number of groups", HFILL }},
{ &hf_holdtime,
{ "Holdtime", "msnip.holdtime", FT_UINT32, BASE_DEC,
NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
{ &hf_groups,
{ "Groups", "msnip.groups", FT_NONE, BASE_NONE,
NULL, 0, "MSNIP Groups", HFILL }},
{ &hf_maddr,
{ "Multicast group", "msnip.maddr", FT_IPv4, BASE_NONE,
NULL, 0, "MSNIP Multicast Group", HFILL }},
{ &hf_mask,
{ "Netmask", "msnip.netmask", FT_UINT8, BASE_DEC,
NULL, 0, "MSNIP Netmask", HFILL }},
{ &hf_holdtime16,
{ "Holdtime", "msnip.holdtime16", FT_UINT16, BASE_DEC,
NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
{ &hf_genid,
{ "Generation ID", "msnip.genid", FT_UINT16, BASE_DEC,
NULL, 0, "MSNIP Generation ID", HFILL }},
{ &hf_rec_type,
{ "Record Type", "msnip.rec_type", FT_UINT8, BASE_DEC,
VALS(msnip_rec_types), 0, "MSNIP Record Type", HFILL }},
};
static gint *ett[] = {
&ett_msnip,
&ett_groups,
};
static ei_register_info ei[] = {
{ &ei_checksum, { "msnip.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
};
expert_module_t* expert_msnip;
proto_msnip = proto_register_protocol("MSNIP: Multicast Source Notification of Interest Protocol", "MSNIP", "msnip");
proto_register_field_array(proto_msnip, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_msnip = expert_register_protocol(proto_msnip);
expert_register_field_array(expert_msnip, ei, array_length(ei));
msnip_handle = register_dissector("msnip", dissect_msnip, proto_msnip);
}
void
proto_reg_handoff_msnip(void)
{
dissector_add_uint("igmp.type", IGMP_TYPE_0x23, msnip_handle);
dissector_add_uint("igmp.type", IGMP_TYPE_0x24, msnip_handle);
dissector_add_uint("igmp.type", IGMP_TYPE_0x25, msnip_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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