Wireshark · Ethereal-dev: [ethereal-dev] zebra dissector

[Jochen Friedrich <jochen@xxxxxxxx>]

Hi there,

this is a first version of a Zebra protocol dissector. It dissects the
protocol internally used by zebra (see http://www.zebra.org) for the
communication between the main zebra daemon and the various routing
protocol deamons. Nice to have when debugging zebra itself :-)

Cheers,
Jochen

/* packet-zebra.c
 * Routines for zebra packet disassembly
 *
 * Jochen Friedrich <jochen@xxxxxxxx>
 *
 * $Id:$
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@xxxxxxxx>
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#include <string.h>
#include <ctype.h>

#include <glib.h>
#include "packet.h"

static int proto_zebra = -1;
static int hf_zebra_len = -1;
static int hf_zebra_command = -1;
static int hf_zebra_request = -1;
static int hf_zebra_interface = -1;
static int hf_zebra_index = -1;
static int hf_zebra_type = -1;
static int hf_zebra_flags = -1;
static int hf_zebra_metric = -1;
static int hf_zebra_mtu = -1;
static int hf_zebra_family = -1;
static int hf_zebra_nexthop4 = -1;
static int hf_zebra_nexthop6 = -1;
static int hf_zebra_dest4 = -1;
static int hf_zebra_dest6 = -1;
static int hf_zebra_prefixlen = -1;
static int hf_zebra_prefix4 = -1;
static int hf_zebra_prefix6 = -1;

static gint ett_zebra = -1;
static gint ett_zebra_request = -1;

#define TCP_PORT_ZEBRA			2600

/* Zebra message types. */
#define ZEBRA_INTERFACE_ADD                1
#define ZEBRA_INTERFACE_DELETE             2
#define ZEBRA_INTERFACE_ADDRESS_ADD        3
#define ZEBRA_INTERFACE_ADDRESS_DELETE     4
#define ZEBRA_IPV4_ROUTE_ADD               5
#define ZEBRA_IPV4_ROUTE_DELETE            6
#define ZEBRA_IPV6_ROUTE_ADD               7
#define ZEBRA_IPV6_ROUTE_DELETE            8
#define ZEBRA_REDISTRIBUTE_ADD             9
#define ZEBRA_REDISTRIBUTE_DELETE         10
#define ZEBRA_REDISTRIBUTE_DEFAULT_ADD    11
#define ZEBRA_REDISTRIBUTE_DEFAULT_DELETE 12

/* Is this really correct? */
#define ZEBRA_INTERFACE_UP                11
#define ZEBRA_INTERFACE_DOWN              12

static const value_string messages[] = {
	{ ZEBRA_INTERFACE_ADD,			"Add Interface" },
	{ ZEBRA_INTERFACE_DELETE,		"Delete Interface" },
	{ ZEBRA_INTERFACE_ADDRESS_ADD,		"Add Interface Address" },
	{ ZEBRA_INTERFACE_ADDRESS_DELETE,	"Delete Interface Address" },
	{ ZEBRA_IPV4_ROUTE_ADD,			"Add IPv4 Route" },
	{ ZEBRA_IPV4_ROUTE_DELETE,		"Delete IPv4 Route" },
	{ ZEBRA_IPV6_ROUTE_ADD,			"Add IPv6 Route" },
	{ ZEBRA_IPV6_ROUTE_DELETE,		"Delete IPv6 Route" },
	{ ZEBRA_REDISTRIBUTE_ADD,		"Add Redistribute" },
	{ ZEBRA_REDISTRIBUTE_DELETE,		"Delete Redistribute" },
	{ ZEBRA_REDISTRIBUTE_DEFAULT_ADD,	"Add Default Redistribute" },
	{ ZEBRA_REDISTRIBUTE_DEFAULT_DELETE,	"Delete Default Redistribute" },
	{ 0,					NULL },
};

/* Zebra route's types. */
#define ZEBRA_ROUTE_SYSTEM               0
#define ZEBRA_ROUTE_KERNEL               1
#define ZEBRA_ROUTE_CONNECT              2
#define ZEBRA_ROUTE_STATIC               3
#define ZEBRA_ROUTE_RIP                  4
#define ZEBRA_ROUTE_RIPNG                5
#define ZEBRA_ROUTE_OSPF                 6
#define ZEBRA_ROUTE_OSPF6                7
#define ZEBRA_ROUTE_BGP                  8

static const value_string routes[] = {
	{ ZEBRA_ROUTE_SYSTEM,			"System Route" },
	{ ZEBRA_ROUTE_KERNEL,			"Kernel Route" },
	{ ZEBRA_ROUTE_CONNECT,			"Connected Route" },
	{ ZEBRA_ROUTE_STATIC,			"Static Route" },
	{ ZEBRA_ROUTE_RIP,			"RIP Route" },
	{ ZEBRA_ROUTE_RIPNG,			"RIPnG Route" },
	{ ZEBRA_ROUTE_OSPF,			"OSPF Route" },
	{ ZEBRA_ROUTE_OSPF6,			"OSPF6 Route" },
	{ ZEBRA_ROUTE_BGP,			"BGP Route" },
	{ 0,					NULL },
};

/* Zebra's family types. */
#define ZEBRA_FAMILY_IPV4                1
#define ZEBRA_FAMILY_IPV6                2

static const value_string families[] = {
	{ ZEBRA_FAMILY_IPV4,			"IPv4" },
	{ ZEBRA_FAMILY_IPV6,			"IPv6" },
	{ 0,					NULL },
};

/* Error codes of zebra. */
#define ZEBRA_ERR_RTEXIST                1
#define ZEBRA_ERR_RTUNREACH              2
#define ZEBRA_ERR_EPERM                  3
#define ZEBRA_ERR_RTNOEXIST              4

static const value_string errors[] = {
	{ ZEBRA_ERR_RTEXIST,			"Route Exists" },
	{ ZEBRA_ERR_RTUNREACH,			"Route Unreachable" },
	{ ZEBRA_ERR_EPERM,			"Permission Denied" },
	{ ZEBRA_ERR_RTNOEXIST,			"Route Does Not Exist" },
	{ 0,					NULL },
};

/* Zebra message flags */
#define ZEBRA_FLAG_INTERNAL           0x01
#define ZEBRA_FLAG_SELFROUTE          0x02
#define ZEBRA_FLAG_BLACKHOLE          0x04

/* Subsequent Address Family Identifier. */
#define ZEBRA_SAFI_UNICAST               1
#define ZEBRA_SAFI_MULTICAST             2
#define ZEBRA_SAFI_UNICAST_MULTICAST     3
#define ZEBRA_SAFI_MPLS_VPN              4

static const value_string safis[] = {
	{ ZEBRA_SAFI_UNICAST,			"Unicast" },
	{ ZEBRA_SAFI_MULTICAST,			"Multicast" },
	{ ZEBRA_SAFI_UNICAST_MULTICAST,		"Unicast And Multicast" },
	{ ZEBRA_SAFI_MPLS_VPN,			"MPLS VPN" },
	{ 0,					NULL },
};

#define INTERFACE_NAMSIZ      20

#define PSIZE(a) (((a) + 7) / (8))

void
dissect_zebra_request(proto_tree *tree, gboolean request, tvbuff_t *tvb,
	int offset, guint16 len, guint8 command)
{
	guint32	flags, metric, mtu, prefix4, destination4, nexthop4;
	guint16 index, i;
	guint8  family, prefixlen, type, buffer6[16];
	gpointer prefix6, destination6, nexthop6, prefix, ptr;

	proto_tree_add_uint(tree, hf_zebra_len, NullTVB, offset, 2, len);
	offset += 2;
	if ((command == ZEBRA_REDISTRIBUTE_DEFAULT_ADD) && (!request))
		proto_tree_add_string(tree, hf_zebra_command, NullTVB, offset,
			 1, "Interface Up");
	else if ((command == ZEBRA_REDISTRIBUTE_DEFAULT_DELETE) && (!request))
		proto_tree_add_string(tree, hf_zebra_command, NullTVB, offset,				 1, "Interface Down");
	else proto_tree_add_string(tree, hf_zebra_command, NullTVB, offset, 1, 
		val_to_str(command, messages, "Unknown command: %d"));
	offset += 1;
	switch(command) {
		case ZEBRA_INTERFACE_ADD:
			add:
			proto_tree_add_string(tree, hf_zebra_interface, 
				NullTVB, offset, INTERFACE_NAMSIZ, 
				tvb_get_ptr(tvb, offset, INTERFACE_NAMSIZ));
			offset += INTERFACE_NAMSIZ;

			index = tvb_get_ntohs(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_index, NullTVB,
				 offset, 2, index);
			offset += 2;

			flags = tvb_get_ntohl(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_flags, NullTVB,
				 offset, 4, flags);
			offset += 4;
			
			metric = tvb_get_ntohl(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_metric, NullTVB,
				 offset, 4, metric);
			offset += 4;

			mtu = tvb_get_ntohl(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_mtu, NullTVB,
				 offset, 4, mtu);
			offset += 4;

			break;
		case ZEBRA_INTERFACE_DELETE:
			proto_tree_add_string(tree, hf_zebra_interface,
				NullTVB, offset, INTERFACE_NAMSIZ,
				tvb_get_ptr(tvb, offset, INTERFACE_NAMSIZ));
			offset += INTERFACE_NAMSIZ;

			index = tvb_get_ntohs(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_index, NullTVB,
				 offset, 2, index);
			offset += 2;
			break;
		case ZEBRA_INTERFACE_ADDRESS_ADD:
		case ZEBRA_INTERFACE_ADDRESS_DELETE:
			index = tvb_get_ntohs(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_index, NullTVB,
				 offset, 2, index);
			offset += 2;

			family = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_family, NullTVB,
				 offset, 1, family);
			offset += 1;

			if (len == 15) { /* IPv4 */
				prefix4 = tvb_get_letohl(tvb, offset);
				proto_tree_add_ipv4(tree, hf_zebra_prefix4,
					NullTVB, offset, 4, prefix4);
				offset += 4;
			}
			else if (len == 39) { /* IPv6 */
				prefix6 = tvb_get_ptr(tvb, offset, 16);
				proto_tree_add_ipv6(tree, hf_zebra_prefix6,
					NullTVB, offset, 16, prefix6);
				offset += 16;
			}
			else break;

			prefixlen = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_prefixlen, NullTVB,
				 offset, 1, prefixlen);
			offset += 1;

			if (len == 15) { /* IPv4 */
				destination4 = tvb_get_letohl(tvb, offset);
				proto_tree_add_ipv4(tree, hf_zebra_dest4,
					NullTVB, offset, 4, destination4);
				offset += 4;
			}
			else if (len == 39) { /* IPv6 */
				destination6 = tvb_get_ptr(tvb, offset, 16);
				proto_tree_add_ipv6(tree, hf_zebra_dest6,
					NullTVB, offset, 16, destination6);
				offset += 16;
			}
			break;

		case ZEBRA_IPV4_ROUTE_ADD:
		case ZEBRA_IPV4_ROUTE_DELETE:
			type = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_type, NullTVB,
				 offset, 1, type);
			offset += 1;

			flags = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_flags, NullTVB,
				 offset, 1, flags);
			offset += 1;

			nexthop4 = tvb_get_letohl(tvb, offset);
			proto_tree_add_ipv4(tree, hf_zebra_nexthop4,
				NullTVB, offset, 4, nexthop4);
			offset += 4;

			index = tvb_get_ntohl(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_index, NullTVB,
				 offset, 4, index);
			offset += 4;

			prefixlen = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_prefixlen, NullTVB,
				 offset, 1, prefixlen);
			offset += 1;

			prefix = tvb_get_ptr(tvb, offset, PSIZE(prefixlen));
			prefix4 = 0;
			ptr = (gpointer) &prefix4;

			for (i=0; i< PSIZE(prefixlen); i++)
				*(guint8*)ptr++ = *(guint8*)prefix++;
			proto_tree_add_ipv4(tree, hf_zebra_prefix4,
				NullTVB, offset, 4, prefix4);
			offset += PSIZE(prefixlen);
			break;
		case ZEBRA_IPV6_ROUTE_ADD:
		case ZEBRA_IPV6_ROUTE_DELETE:
			type = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_type, NullTVB,
				 offset, 1, type);
			offset += 1;

			flags = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_flags, NullTVB,
				 offset, 1, flags);
			offset += 1;

			nexthop6 = tvb_get_ptr(tvb, offset, 16);
			proto_tree_add_ipv6(tree, hf_zebra_nexthop6,
				NullTVB, offset, 16, nexthop6);
			offset += 16;

			index = tvb_get_ntohs(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_index, NullTVB,
				 offset, 4, index);
			offset += 4;

			prefixlen = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_prefixlen, NullTVB,
				 offset, 1, prefixlen);
			offset += 1;

			prefix = tvb_get_ptr(tvb, offset, PSIZE(prefixlen));
			for (i=0; i < 16; i++) buffer6[i] = 0;
			ptr = (gpointer) buffer6;

			for (i=0; i< PSIZE(prefixlen); i++)
				*(guint8*)ptr++ = *(guint8*)prefix++;
			proto_tree_add_ipv6(tree, hf_zebra_prefix6,
				NullTVB, offset, 16, prefix6);
			offset += PSIZE(prefixlen);
			break;
		case ZEBRA_REDISTRIBUTE_ADD:
		case ZEBRA_REDISTRIBUTE_DELETE:
			type = tvb_get_guint8(tvb, offset);
			proto_tree_add_uint(tree, hf_zebra_type, NullTVB,
				 offset, 1, type);
			offset += 1;
		case ZEBRA_REDISTRIBUTE_DEFAULT_ADD:
		case ZEBRA_REDISTRIBUTE_DEFAULT_DELETE:
			if (!request) goto add; /* IF Up / IF Down */

			break;
	}
}
		
void
dissect_zebra(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
{
	proto_item	*ti;
	proto_tree	*zebra_tree;
	tvbuff_t	*tvb;
	gboolean	request;
	int		left;

	if (check_col(fd, COL_PROTOCOL))
		col_add_str(fd, COL_PROTOCOL, "ZEBRA");

	tvb = tvb_create_from_top(0);
	request = (pi.destport == TCP_PORT_ZEBRA);
	left = tvb_reported_length(tvb) - offset;

	if (check_col(fd, COL_INFO)) {
		col_add_str(fd, COL_INFO, 
			request? "ZEBRA Request" : "ZEBRA Reply");
	}
	if (tree) {
		ti = proto_tree_add_boolean_hidden(tree, hf_zebra_request,
			NullTVB, offset, END_OF_FRAME, request);
		ti = proto_tree_add_item(tree, proto_zebra, NullTVB, offset,
			END_OF_FRAME, FALSE);
		zebra_tree = proto_item_add_subtree(ti, ett_zebra);

		for (;;) {
			guint8		command;
			guint16		len;
			proto_tree	*zebra_request_tree;
			
			if (left < 3) break;

			len = tvb_get_ntohs(tvb, offset);
			if (len < 3) break;

			command = tvb_get_guint8(tvb, offset+2);

			if ((command == ZEBRA_REDISTRIBUTE_DEFAULT_ADD)
				&& (!request))
				ti = proto_tree_add_string(zebra_tree,
					hf_zebra_command, NullTVB, offset, len,
					"Interface Up");
			else if ((command == ZEBRA_REDISTRIBUTE_DEFAULT_DELETE)
				&& (!request))
				ti = proto_tree_add_string(zebra_tree,
					hf_zebra_command, NullTVB, offset, len,
					"Interface Down");
			else ti = proto_tree_add_string(zebra_tree,
					hf_zebra_command, NullTVB, offset, len,
					val_to_str(command,
				messages, "Unknown command: %d"));
			zebra_request_tree = proto_item_add_subtree(ti,
				ett_zebra_request);
			dissect_zebra_request(zebra_request_tree, request, tvb,
				offset, len, command);

			offset += len;
			left -= len;
		}
	}
}

void
proto_register_zebra(void)
{

  static hf_register_info hf[] = {
    { &hf_zebra_len,
      { "Length",		"zebra.len",
	FT_UINT16, BASE_DEC, NULL, 0x0,
	"Length of ZEBRA request" }},
    { &hf_zebra_request,
      { "Request",		"zebra.request",
	FT_BOOLEAN, BASE_NONE, NULL, 0x0,
	"TRUE if ZEBRA request" }},
    { &hf_zebra_command,
      { "Command",		"zebra.command",
	FT_STRING, BASE_NONE, NULL, 0x0,
	"ZEBRA command" }},
    { &hf_zebra_interface,
      { "Interface",		"zebra.interface",
	FT_STRING, BASE_NONE, NULL, 0x0,
	"Interface name of ZEBRA request" }},
    { &hf_zebra_index,
      { "Index",		"zebra.index",
	FT_UINT16, BASE_DEC, NULL, 0x0,
	"Index of interface" }},
    { &hf_zebra_flags,
      { "Flags",		"zebra.flags",
	FT_UINT32, BASE_DEC, NULL, 0x0,
	"Flags of interface" }},
    { &hf_zebra_type,
      { "Type",			"zebra.type",
	FT_UINT8, BASE_DEC, NULL, 0x0,
	"Type of route" }},
    { &hf_zebra_metric,
      { "Metric",		"zebra.metric",
	FT_UINT32, BASE_DEC, NULL, 0x0,
	"Metric of interface" }},
    { &hf_zebra_mtu,
      { "MTU",			"zebra.mtu",
	FT_UINT32, BASE_DEC, NULL, 0x0,
	"MTU of interface" }},
    { &hf_zebra_family,
      { "Family",		"zebra.family",
	FT_UINT32, BASE_DEC, NULL, 0x0,
	"Family of IP address" }},
    { &hf_zebra_dest4,
      { "Destination",		"zebra.dest4",
	FT_IPv4, BASE_NONE, NULL, 0x0,
	"Destination IPv4 field" }},
    { &hf_zebra_dest6,
      { "Destination",		"zebra.dest6",
	FT_IPv6, BASE_NONE, NULL, 0x0,
	"Destination IPv6 field" }},
    { &hf_zebra_nexthop4,
      { "Nexthop",		"zebra.nexthop4",
	FT_IPv4, BASE_NONE, NULL, 0x0,
	"Nethop IPv4 field of route" }},
    { &hf_zebra_nexthop6,
      { "Nexthop",		"zebra.nexthop6",
	FT_IPv6, BASE_NONE, NULL, 0x0,
	"Nethop IPv6 field of route" }},
    { &hf_zebra_prefixlen,
      { "Prefix length",	"zebra.prefixlen",
	FT_UINT32, BASE_DEC, NULL, 0x0,
	"Prefix length" }},
    { &hf_zebra_prefix4,
      { "Prefix",		"zebra.prefix4",
	FT_IPv4, BASE_NONE, NULL, 0x0,
	"Prefix IPv4" }},
    { &hf_zebra_prefix6,
      { "Prefix",		"zebra.prefix6",
	FT_IPv6, BASE_NONE, NULL, 0x0,
	"Prefix IPv6" }},
  };

  static gint *ett[] = {
    &ett_zebra,
    &ett_zebra_request,
  };

  proto_zebra = proto_register_protocol("Zebra Protocol", "zebra");
  proto_register_field_array(proto_zebra, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_zebra(void)
{
  dissector_add("tcp.port", TCP_PORT_ZEBRA, dissect_zebra);
}