print-geonet.c

/*
 * Copyright (c) 2013 The TCPDUMP project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code
 * distributions retain the above copyright notice and this paragraph
 * in its entirety, and (2) distributions including binary code include
 * the above copyright notice and this paragraph in its entirety in
 * the documentation or other materials provided with the distribution.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * Original code by Ola Martin Lykkja (ola.lykkja@q-free.com)
 */

/* \summary: ISO CALM FAST and ETSI GeoNetworking printer */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "netdissect-stdinc.h"

#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"


/*
   ETSI TS 102 636-5-1 V1.1.1 (2011-02)
   Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking;
   Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol

   ETSI TS 102 636-4-1 V1.1.1 (2011-06)
   Intelligent Transport Systems (ITS); Vehicular communications; GeoNetworking;
   Part 4: Geographical addressing and forwarding for point-to-point and point-to-multipoint communications;
   Sub-part 1: Media-Independent Functionality
*/

#define GEONET_ADDR_LEN 8

static const struct tok msg_type_values[] = {
	{   0, "CAM" },
	{   1, "DENM" },
	{ 101, "TPEGM" },
	{ 102, "TSPDM" },
	{ 103, "VPM" },
	{ 104, "SRM" },
	{ 105, "SLAM" },
	{ 106, "ecoCAM" },
	{ 107, "ITM" },
	{ 150, "SA" },
	{   0, NULL }
};

static void
print_btp_body(netdissect_options *ndo,
	       const u_char *bp)
{
	u_int msg_type;

	/* Assuming ItsPduHeader */
	ND_PRINT("; ItsPduHeader v:%u", GET_U_1(bp));

	msg_type = GET_U_1(bp + 1);
	ND_PRINT(" t:%u-%s", msg_type,
	         tok2str(msg_type_values, "unknown (%u)", msg_type));
}

/* EN 302 636-5-1 V2.2.1 Section 7.2: BTP-A header */
static void
print_btp(netdissect_options *ndo,
	  const u_char *bp)
{
	ND_PRINT("; BTP Dst:%u", GET_BE_U_2(bp + 0));
	ND_PRINT(" Src:%u", GET_BE_U_2(bp + 2));
}

static void
print_long_pos_vector(netdissect_options *ndo,
		      const u_char *bp)
{
	ND_PRINT("GN_ADDR:%s ", GET_LINKADDR_STRING(bp, LINKADDR_OTHER, GEONET_ADDR_LEN));
	ND_PRINT("lat:%u ", GET_BE_U_4(bp + 12));
	ND_PRINT("lon:%u", GET_BE_U_4(bp + 16));
}


/*
 * This is the top level routine of the printer.  'p' points
 * to the geonet header of the packet.
 */
void
geonet_print(netdissect_options *ndo, const u_char *bp, u_int length,
	     const struct lladdr_info *src)
{
	u_int version;
	u_int next_hdr;
	u_int hdr_type;
	u_int hdr_subtype;
	uint16_t payload_length;
	u_int hop_limit;
	const char *next_hdr_txt = "Unknown";
	const char *hdr_type_txt = "Unknown";
	int hdr_size = -1;

	ndo->ndo_protocol = "geonet";
	ND_PRINT("GeoNet ");
	if (src != NULL)
		ND_PRINT("src:%s", (src->addr_string)(ndo, src->addr));
	ND_PRINT("; ");

	/* Process Common Header */
	if (length < 36) {
		ND_PRINT(" (common header length %u < 36)", length);
		goto invalid;
	}

	version = GET_U_1(bp) >> 4;
	next_hdr = GET_U_1(bp) & 0x0f;
	hdr_type = GET_U_1(bp + 1) >> 4;
	hdr_subtype = GET_U_1(bp + 1) & 0x0f;
	payload_length = GET_BE_U_2(bp + 4);
	hop_limit = GET_U_1(bp + 7);

	switch (next_hdr) {
		case 0: next_hdr_txt = "Any"; break;
		case 1: next_hdr_txt = "BTP-A"; break;
		case 2: next_hdr_txt = "BTP-B"; break;
		case 3: next_hdr_txt = "IPv6"; break;
	}

	switch (hdr_type) {
		case 0: hdr_type_txt = "Any"; break;
		case 1: hdr_type_txt = "Beacon"; break;
		case 2: hdr_type_txt = "GeoUnicast"; break;
		case 3: switch (hdr_subtype) {
				case 0: hdr_type_txt = "GeoAnycastCircle"; break;
				case 1: hdr_type_txt = "GeoAnycastRect"; break;
				case 2: hdr_type_txt = "GeoAnycastElipse"; break;
			}
			break;
		case 4: switch (hdr_subtype) {
				case 0: hdr_type_txt = "GeoBroadcastCircle"; break;
				case 1: hdr_type_txt = "GeoBroadcastRect"; break;
				case 2: hdr_type_txt = "GeoBroadcastElipse"; break;
			}
			break;
		case 5: switch (hdr_subtype) {
				case 0: hdr_type_txt = "TopoScopeBcast-SH"; break;
				case 1: hdr_type_txt = "TopoScopeBcast-MH"; break;
			}
			break;
		case 6: switch (hdr_subtype) {
				case 0: hdr_type_txt = "LocService-Request"; break;
				case 1: hdr_type_txt = "LocService-Reply"; break;
			}
			break;
	}

	ND_PRINT("v:%u ", version);
	ND_PRINT("NH:%u-%s ", next_hdr, next_hdr_txt);
	ND_PRINT("HT:%u-%u-%s ", hdr_type, hdr_subtype, hdr_type_txt);
	ND_PRINT("HopLim:%u ", hop_limit);
	ND_PRINT("Payload:%u ", payload_length);
	print_long_pos_vector(ndo, bp + 8);

	/* Skip Common Header */
	ND_TCHECK_LEN(bp, 36);
	length -= 36;
	bp += 36;

	/* Process Extended Headers */
	switch (hdr_type) {
		case 0: /* Any */
			hdr_size = 0;
			break;
		case 1: /* Beacon */
			hdr_size = 0;
			break;
		case 2: /* GeoUnicast */
			break;
		case 3: switch (hdr_subtype) {
				case 0: /* GeoAnycastCircle */
					break;
				case 1: /* GeoAnycastRect */
					break;
				case 2: /* GeoAnycastElipse */
					break;
			}
			break;
		case 4: switch (hdr_subtype) {
				case 0: /* GeoBroadcastCircle */
					break;
				case 1: /* GeoBroadcastRect */
					break;
				case 2: /* GeoBroadcastElipse */
					break;
			}
			break;
		case 5: switch (hdr_subtype) {
				case 0: /* TopoScopeBcast-SH */
					hdr_size = 0;
					break;
				case 1: /* TopoScopeBcast-MH */
					hdr_size = 68 - 36;
					break;
			}
			break;
		case 6: switch (hdr_subtype) {
				case 0: /* LocService-Request */
					break;
				case 1: /* LocService-Reply */
					break;
			}
			break;
	}

	/* Skip Extended headers */
	if (hdr_size >= 0) {
		if (length < (u_int)hdr_size) {
			ND_PRINT(" (header size %d > %u)", hdr_size, length);
			goto invalid;
		}
		ND_TCHECK_LEN(bp, hdr_size);
		length -= hdr_size;
		bp += hdr_size;
		switch (next_hdr) {
			case 0: /* Any */
				break;
			case 1:
			case 2: /* BTP A/B */
				if (length < 4) {
					ND_PRINT(" (BTP length %u < 4)", length);
					goto invalid;
				}
				print_btp(ndo, bp);
				length -= 4;
				bp += 4;
				if (length >= 2) {
					/*
					 * XXX - did print_btp_body()
					 * return if length < 2
					 * because this is optional,
					 * or was that just not
					 * reporting genuine errors?
					 */
					print_btp_body(ndo, bp);
				}
				break;
			case 3: /* IPv6 */
				break;
		}
	}

	/* Print user data part */
	if (ndo->ndo_vflag)
		ND_DEFAULTPRINT(bp, length);
	return;

invalid:
	nd_print_invalid(ndo);
	/* XXX - print the remaining data as hex? */
}