nexmon – Rev 1
?pathlinks?
/* packet-babel.c
* Routines for Babel dissection (RFC 6126)
* Copyright 2011 by Juliusz Chroboczek <jch@pps.jussieu.fr>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/to_str.h>
void proto_register_babel(void);
void proto_reg_handoff_babel(void);
static int proto_babel = -1;
static gint ett_babel = -1;
static int hf_babel_magic = -1;
static int hf_babel_version = -1;
static int hf_babel_bodylen = -1;
static int hf_babel_message = -1;
static gint ett_message = -1;
static int hf_babel_message_type = -1;
static int hf_babel_message_length = -1;
static int hf_babel_message_nonce = -1;
static int hf_babel_message_interval = -1;
static int hf_babel_message_seqno = -1;
static int hf_babel_message_ae = -1;
static int hf_babel_message_prefix = -1;
static int hf_babel_message_rxcost = -1;
static int hf_babel_message_routerid = -1;
static int hf_babel_message_flags = -1;
static int hf_babel_message_plen = -1;
static int hf_babel_message_omitted = -1;
static int hf_babel_message_metric = -1;
static int hf_babel_message_hopcount = -1;
static gint ett_subtree = -1;
#define UDP_PORT_BABEL 6696
#define UDP_PORT_BABEL_OLD 6697
#define MESSAGE_PAD1 0
#define MESSAGE_PADN 1
#define MESSAGE_ACK_REQ 2
#define MESSAGE_ACK 3
#define MESSAGE_HELLO 4
#define MESSAGE_IHU 5
#define MESSAGE_ROUTER_ID 6
#define MESSAGE_NH 7
#define MESSAGE_UPDATE 8
#define MESSAGE_REQUEST 9
#define MESSAGE_MH_REQUEST 10
#define MESSAGE_TS_PC 11
#define MESSAGE_HMAC 12
#define MESSAGE_SRC_UPDATE 13
#define MESSAGE_SRC_REQUEST 14
#define MESSAGE_SRC_SEQNO 15
/** message string values listed in rfc7557 */
static const value_string messages[] = {
{ MESSAGE_PAD1, "pad1"},
{ MESSAGE_PADN, "padn"},
{ MESSAGE_ACK_REQ, "ack-req"},
{ MESSAGE_ACK, "ack"},
{ MESSAGE_HELLO, "hello"},
{ MESSAGE_IHU, "ihu"},
{ MESSAGE_ROUTER_ID, "router-id"},
{ MESSAGE_NH, "nh"},
{ MESSAGE_UPDATE, "update"},
{ MESSAGE_REQUEST, "request"},
{ MESSAGE_MH_REQUEST, "mh-request"},
{ MESSAGE_TS_PC, "ts/pc"},
{ MESSAGE_HMAC, "hmac" },
{ MESSAGE_SRC_UPDATE, "source-specific-update"},
{ MESSAGE_SRC_REQUEST,"source-specific-req"},
{ MESSAGE_SRC_SEQNO, "source-specific-seqno"},
{ 0, NULL}
};
static const value_string aes[] = {
{ 0, "Wildcard" },
{ 1, "IPv4" },
{ 2, "IPv6" },
{ 3, "Link-Local IPv6"},
{ 0, NULL }
};
/* The prefix for v6-mapped IPv4 addresses. Format_address below
returns IPv4 addresses in that format. */
static const unsigned char v4prefix[16] =
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
/* The following two functions return ephemeral or constant strings, no
need to call free. */
static const char *
format_address(const unsigned char *prefix)
{
address addr;
if (prefix == NULL)
return "corrupt";
else if (memcmp(prefix, v4prefix, 12) == 0)
{
addr.type = AT_IPv4;
addr.len = 4;
addr.data = prefix + 12;
return address_to_str(wmem_packet_scope(), &addr);
}
else
{
addr.type = AT_IPv6;
addr.len = 16;
addr.data = prefix;
return address_to_str(wmem_packet_scope(), &addr);
}
}
static const char *
format_prefix(const unsigned char *prefix, unsigned char plen)
{
return wmem_strdup_printf(wmem_packet_scope(), "%s/%u", format_address(prefix), plen);
}
static int
network_prefix(int ae, int plen, unsigned int omitted,
tvbuff_t *tvb, int offset, const unsigned char *dp,
unsigned int len, unsigned char *p_r)
{
guint pb;
unsigned char prefix[16];
if (plen >= 0)
pb = (plen + 7) / 8;
else if (ae == 1)
pb = 4;
else
pb = 16;
if (pb > 16)
return -1;
memset(prefix, 0, 16);
switch(ae) {
case 0: break;
case 1:
if (omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
return -1;
memcpy(prefix, v4prefix, 12);
if (omitted) {
if (dp == NULL) return -1;
memcpy(prefix, dp, 12 + omitted);
}
if (pb > omitted)
tvb_memcpy(tvb, prefix + 12 + omitted, offset, pb - omitted);
break;
case 2:
if (omitted > 16 || (pb > omitted && len < pb - omitted))
return -1;
if (omitted) {
if (dp == NULL) return -1;
memcpy(prefix, dp, omitted);
}
if (pb > omitted)
tvb_memcpy(tvb, prefix + omitted, offset, pb - omitted);
break;
case 3:
if (pb > 8 && len < pb - 8) return -1;
prefix[0] = 0xfe;
prefix[1] = 0x80;
if (pb > 8)
tvb_memcpy(tvb, prefix + 8, offset, pb - 8);
break;
default:
return -1;
}
memcpy(p_r, prefix, 16);
return 1;
}
static int
network_address(int ae, tvbuff_t *tvb, int offset, unsigned int len,
unsigned char *a_r)
{
return network_prefix(ae, -1, 0, tvb, offset, NULL, len, a_r);
}
static int
dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti;
unsigned char v4_prefix[16] = {0}, v6_prefix[16] = {0};
int i;
proto_tree *babel_tree = NULL;
guint8 version;
guint16 bodylen;
if (tvb_captured_length(tvb) < 4)
return 0;
if (tvb_get_guint8(tvb, 0) != 42)
return 0;
version = tvb_get_guint8(tvb, 1);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Babel");
col_set_str(pinfo->cinfo, COL_INFO, "Babel");
if (version != 2) {
col_add_fstr(pinfo->cinfo, COL_INFO, "Version %u", version);
return 2;
}
if (tree) {
ti = proto_tree_add_item(tree, proto_babel, tvb, 0, -1, ENC_NA);
babel_tree = proto_item_add_subtree(ti, ett_babel);
proto_tree_add_item(babel_tree, hf_babel_magic, tvb, 0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(babel_tree, hf_babel_version, tvb, 1, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(babel_tree, hf_babel_bodylen,
tvb, 2, 2, ENC_BIG_ENDIAN);
}
bodylen = tvb_get_ntohs(tvb, 2);
i = 0;
while (i < bodylen) {
guint8 type, len = 0, total_length;
proto_tree *message_tree = NULL;
int message = 4 + i;
type = tvb_get_guint8(tvb, message);
if (type == MESSAGE_PAD1)
total_length = 1;
else {
len = tvb_get_guint8(tvb, message + 1);
total_length = len + 2;
}
col_append_fstr(pinfo->cinfo, COL_INFO, " %s",
val_to_str_const(type, messages, "unknown"));
ti = proto_tree_add_uint_format(babel_tree, hf_babel_message,
tvb, message, total_length, type,
"Message %s (%u)",
val_to_str_const(type, messages, "unknown"),
type);
if (tree) {
message_tree = proto_item_add_subtree(ti, ett_message);
proto_tree_add_item(message_tree, hf_babel_message_type,
tvb, message, 1, ENC_BIG_ENDIAN);
}
if (type == MESSAGE_PAD1) {
i++;
continue;
}
if (tree) {
proto_tree_add_item(message_tree, hf_babel_message_length,
tvb, message + 1, 1, ENC_BIG_ENDIAN);
if (type == MESSAGE_PADN) {
} else if (type == MESSAGE_ACK_REQ) {
proto_tree_add_item(message_tree, hf_babel_message_nonce,
tvb, message + 4, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_interval,
tvb, message + 6, 2, ENC_BIG_ENDIAN);
} else if (type == MESSAGE_ACK) {
proto_tree_add_item(message_tree, hf_babel_message_nonce,
tvb, message + 2, 2, ENC_BIG_ENDIAN);
} else if (type == MESSAGE_HELLO) {
proto_tree_add_item(message_tree, hf_babel_message_seqno,
tvb, message + 4, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_interval,
tvb, message + 6, 2, ENC_BIG_ENDIAN);
} else if (type == MESSAGE_IHU) {
proto_tree *subtree;
unsigned char addr_str[16];
int rc =
network_address(tvb_get_guint8(tvb, message + 2),
tvb, message + 8, len - 6, addr_str);
proto_tree_add_item(message_tree, hf_babel_message_rxcost,
tvb, message + 4, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_interval,
tvb, message + 6, 2, ENC_BIG_ENDIAN);
subtree = proto_tree_add_subtree_format(message_tree,
tvb, message + 4, len - 2,
ett_subtree, NULL, "Address: %s",
format_address(rc < 0 ?
NULL : addr_str));
proto_tree_add_item(subtree, hf_babel_message_ae,
tvb, message + 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_prefix,
tvb, message + 4, len - 2, ENC_NA);
} else if (type == MESSAGE_ROUTER_ID) {
proto_tree_add_item(message_tree, hf_babel_message_routerid,
tvb, message + 4, 8, ENC_NA);
} else if (type == MESSAGE_NH) {
proto_tree *subtree;
unsigned char nh[16];
int rc =
network_address(tvb_get_guint8(tvb, message + 2),
tvb, message + 4, len - 2, nh);
subtree = proto_tree_add_subtree_format(message_tree,
tvb, message + 4, len - 2,
ett_subtree, NULL,
"NH: %s",
format_address(rc < 0 ? NULL : nh));
proto_tree_add_item(subtree, hf_babel_message_ae,
tvb, message + 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_prefix,
tvb, message + 4, len - 2, ENC_NA);
} else if (type == MESSAGE_UPDATE) {
proto_tree *subtree;
unsigned char p[16];
guint8 ae = tvb_get_guint8(tvb, message + 2);
guint8 flags = tvb_get_guint8(tvb, message + 3);
guint8 plen = tvb_get_guint8(tvb, message + 4);
int rc =
network_prefix(ae, plen,
tvb_get_guint8(tvb, message + 5),
tvb, message + 12,
ae == 1 ? v4_prefix : v6_prefix,
len - 10, p);
if (rc >= 0 && (flags & 0x80)) {
if (ae == 1)
memcpy(v4_prefix, p, 16);
else
memcpy(v6_prefix, p, 16);
}
proto_tree_add_item(message_tree, hf_babel_message_flags,
tvb, message + 3, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_interval,
tvb, message + 6, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_seqno,
tvb, message + 8, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_metric,
tvb, message + 10, 2, ENC_BIG_ENDIAN);
subtree = proto_tree_add_subtree_format(message_tree,
tvb, message + 12, len - 10,
ett_subtree, NULL,
"Prefix: %s",
format_prefix(rc < 0 ? NULL : p,
plen));
proto_tree_add_item(subtree, hf_babel_message_ae,
tvb, message + 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_plen,
tvb, message + 4, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_omitted,
tvb, message + 5, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_prefix,
tvb, message + 12, len - 10, ENC_NA);
} else if (type == MESSAGE_REQUEST) {
proto_tree *subtree;
unsigned char p[16];
guint8 plen = tvb_get_guint8(tvb, message + 3);
int rc =
network_prefix(tvb_get_guint8(tvb, message + 2), plen,
0, tvb, message + 4, NULL,
len - 2, p);
subtree = proto_tree_add_subtree_format(message_tree,
tvb, message + 4, len - 2,
ett_subtree, NULL,
"Prefix: %s",
format_prefix(rc < 0 ? NULL : p,
plen));
proto_tree_add_item(subtree, hf_babel_message_ae,
tvb, message + 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_plen,
tvb, message + 3, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_prefix,
tvb, message + 4, len - 2, ENC_NA);
} else if (type == MESSAGE_MH_REQUEST) {
proto_tree *subtree;
unsigned char p[16];
guint8 plen = tvb_get_guint8(tvb, message + 3);
int rc =
network_prefix(tvb_get_guint8(tvb, message + 2), plen,
0, tvb, message + 16, NULL,
len - 14, p);
proto_tree_add_item(message_tree, hf_babel_message_seqno,
tvb, message + 4, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_hopcount,
tvb, message + 6, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(message_tree, hf_babel_message_routerid,
tvb, message + 8, 8, ENC_NA);
subtree = proto_tree_add_subtree_format(message_tree,
tvb, message + 16, len - 14,
ett_subtree, NULL,
"Prefix: %s",
format_prefix(rc < 0 ? NULL : p,
plen));
proto_tree_add_item(subtree, hf_babel_message_ae,
tvb, message + 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_plen,
tvb, message + 3, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_babel_message_prefix,
tvb, message + 16, len - 14, ENC_NA);
}
}
i += len + 2;
}
return i;
}
void
proto_register_babel(void)
{
static hf_register_info hf[] = {
{ &hf_babel_magic,
{ "Magic", "babel.magic", FT_UINT8, BASE_DEC,
NULL, 0, "Magic value 42", HFILL }
},
{ &hf_babel_version,
{ "Version", "babel.version", FT_UINT8, BASE_DEC,
NULL, 0, "Version of the Babel protocol", HFILL }
},
{ &hf_babel_bodylen,
{ "Body Length", "babel.bodylen", FT_UINT16, BASE_DEC,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message,
{ "Message", "babel.message", FT_UINT8, BASE_DEC,
NULL, 0, "Babel Message", HFILL }
},
{ &hf_babel_message_type,
{ "Message Type", "babel.message.type", FT_UINT8, BASE_DEC,
VALS(messages), 0, NULL, HFILL }
},
{ &hf_babel_message_length,
{ "Message Length", "babel.message.length", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_nonce,
{ "Nonce", "babel.message.nonce", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_interval,
{ "Interval", "babel.message.interval", FT_UINT16, BASE_DEC,
NULL, 0, "Interval (in centiseconds)", HFILL }
},
{ &hf_babel_message_seqno,
{ "Seqno", "babel.message.seqno", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_ae,
{ "Address Encoding", "babel.message.ae", FT_UINT8, BASE_DEC,
VALS(aes), 0, NULL, HFILL }
},
{ &hf_babel_message_prefix,
{ "Raw Prefix", "babel.message.prefix", FT_BYTES, BASE_NONE,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_rxcost,
{ "Rxcost", "babel.message.rxcost", FT_UINT16, BASE_HEX,
NULL, 0, "Rxcost (from the point of vue of the sender)", HFILL }
},
{ &hf_babel_message_routerid,
{ "Router ID", "babel.message.routerid", FT_BYTES, BASE_NONE,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_flags,
{ "Flags", "babel.message.flags", FT_UINT8, BASE_HEX,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_plen,
{ "Prefix Length", "babel.message.plen", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_omitted,
{ "Omitted Bytes", "babel.message.omitted", FT_UINT8, BASE_DEC,
NULL, 0, "Number of bytes omitted from the prefix", HFILL }
},
{ &hf_babel_message_metric,
{ "Metric", "babel.message.metric", FT_UINT16, BASE_DEC,
NULL, 0, NULL, HFILL }
},
{ &hf_babel_message_hopcount,
{ "Hop Count", "babel.message.hopcount", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL }
},
};
static gint *ett[] = {
&ett_babel,
&ett_message,
&ett_subtree,
};
proto_babel =
proto_register_protocol("Babel Routing Protocol", "Babel", "babel");
proto_register_field_array(proto_babel, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_babel(void)
{
dissector_handle_t babel_handle;
babel_handle = create_dissector_handle(dissect_babel, proto_babel);
dissector_add_uint("udp.port", UDP_PORT_BABEL, babel_handle);
dissector_add_uint("udp.port", UDP_PORT_BABEL_OLD, babel_handle);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/