Home | History | Annotate | Line # | Download | only in dist
print-rip.c revision 1.10 
      1 /*
      2  * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1996
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that: (1) source code distributions
      7  * retain the above copyright notice and this paragraph in its entirety, (2)
      8  * distributions including binary code include the above copyright notice and
      9  * this paragraph in its entirety in the documentation or other materials
     10  * provided with the distribution, and (3) all advertising materials mentioning
     11  * features or use of this software display the following acknowledgement:
     12  * ``This product includes software developed by the University of California,
     13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     14  * the University nor the names of its contributors may be used to endorse
     15  * or promote products derived from this software without specific prior
     16  * written permission.
     17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     20  */
     21 
     22 #include <sys/cdefs.h>
     23 #ifndef lint
     24 __RCSID("$NetBSD: print-rip.c,v 1.10 2024/09/02 16:15:32 christos Exp $");
     25 #endif
     26 
     27 /* \summary: Routing Information Protocol (RIP) printer */
     28 
     29 /* specification: RFC 1058, RFC 2453, RFC 4822 */
     30 
     31 #include <config.h>
     32 
     33 #include "netdissect-stdinc.h"
     34 
     35 #include "netdissect.h"
     36 #include "addrtoname.h"
     37 #include "extract.h"
     38 
     39 #include "af.h"
     40 
     41 
     42 /*
     43  * RFC 1058 and RFC 2453 header of packet.
     44  *
     45  *  0                   1                   2                   3 3
     46  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     47  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     48  * | Command (1)   | Version (1)   |           unused              |
     49  * +---------------+---------------+-------------------------------+
     50  */
     51 struct rip {
     52 	nd_uint8_t rip_cmd;		/* request/response */
     53 	nd_uint8_t rip_vers;		/* protocol version # */
     54 	nd_byte    unused[2];		/* unused */
     55 };
     56 
     57 #define	RIPCMD_REQUEST		1	/* want info */
     58 #define	RIPCMD_RESPONSE		2	/* responding to request */
     59 #define	RIPCMD_TRACEON		3	/* turn tracing on */
     60 #define	RIPCMD_TRACEOFF		4	/* turn it off */
     61 /* 5 is reserved */
     62 #define RIPCMD_TRIGREQ		6
     63 #define RIPCMD_TRIGRESP		7
     64 #define RIPCMD_TRIGACK		8
     65 #define RIPCMD_UPDREQ		9
     66 #define RIPCMD_UPDRESP		10
     67 #define RIPCMD_UPDACK		11
     68 
     69 static const struct tok rip_cmd_values[] = {
     70     { RIPCMD_REQUEST,	        "Request" },
     71     { RIPCMD_RESPONSE,	        "Response" },
     72     { RIPCMD_TRACEON,	        "Trace on" },
     73     { RIPCMD_TRACEOFF,	        "Trace off" },
     74     { RIPCMD_TRIGREQ,	        "Triggered Request" },
     75     { RIPCMD_TRIGRESP,	        "Triggered Response" },
     76     { RIPCMD_TRIGACK,	        "Triggered Acknowledgement" },
     77     { RIPCMD_UPDREQ,	        "Update Request" },
     78     { RIPCMD_UPDRESP,	        "Update Response" },
     79     { RIPCMD_UPDACK,	        "Update Acknowledge" },
     80     { 0, NULL}
     81 };
     82 
     83 #define RIP_AUTHLEN  16
     84 #define RIP_ROUTELEN 20
     85 
     86 /*
     87  * First 4 bytes of all RIPv1/RIPv2 entries.
     88  */
     89 struct rip_entry_header {
     90 	nd_uint16_t rip_family;
     91 	nd_uint16_t rip_tag;
     92 };
     93 
     94 /*
     95  * RFC 1058 entry.
     96  *
     97  *  0                   1                   2                   3 3
     98  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     99  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    100  * | Address Family Identifier (2) |       must be zero (2)        |
    101  * +-------------------------------+-------------------------------+
    102  * |                         IP Address (4)                        |
    103  * +---------------------------------------------------------------+
    104  * |                        must be zero (4)                       |
    105  * +---------------------------------------------------------------+
    106  * |                        must be zero (4)                       |
    107  * +---------------------------------------------------------------+
    108  * |                         Metric (4)                            |
    109  * +---------------------------------------------------------------+
    110  */
    111 struct rip_netinfo_v1 {
    112 	nd_uint16_t rip_family;
    113 	nd_byte     rip_mbz1[2];
    114 	nd_ipv4     rip_dest;
    115 	nd_byte     rip_mbz2[4];
    116 	nd_byte     rip_mbz3[4];
    117 	nd_uint32_t rip_metric;		/* cost of route */
    118 };
    119 
    120 
    121 /*
    122  * RFC 2453 route entry
    123  *
    124  *  0                   1                   2                   3 3
    125  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    126  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    127  * | Address Family Identifier (2) |        Route Tag (2)          |
    128  * +-------------------------------+-------------------------------+
    129  * |                         IP Address (4)                        |
    130  * +---------------------------------------------------------------+
    131  * |                         Subnet Mask (4)                       |
    132  * +---------------------------------------------------------------+
    133  * |                         Next Hop (4)                          |
    134  * +---------------------------------------------------------------+
    135  * |                         Metric (4)                            |
    136  * +---------------------------------------------------------------+
    137  *
    138  */
    139 
    140 struct rip_netinfo_v2 {
    141 	nd_uint16_t rip_family;
    142 	nd_uint16_t rip_tag;
    143 	nd_ipv4     rip_dest;
    144 	nd_uint32_t rip_dest_mask;
    145 	nd_ipv4     rip_router;
    146 	nd_uint32_t rip_metric;		/* cost of route */
    147 };
    148 
    149 /*
    150  * RFC 2453 authentication entry
    151  *
    152  *  0                   1                   2                   3 3
    153  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    154  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    155  * |            0xFFFF             |    Authentication Type (2)    |
    156  * +-------------------------------+-------------------------------+
    157  * -                      Authentication (16)                      -
    158  * +---------------------------------------------------------------+
    159  */
    160 
    161 struct rip_auth_v2 {
    162 	nd_uint16_t rip_family;
    163 	nd_uint16_t rip_tag;
    164 	nd_byte     rip_auth[16];
    165 };
    166 
    167 /*
    168  * RFC 4822 Cryptographic Authentication entry.
    169  *
    170  *  0                   1                   2                   3 3
    171  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    172  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    173  * |     RIPv2 Packet Length       |   Key ID      | Auth Data Len |
    174  * +---------------+---------------+---------------+---------------+
    175  * |               Sequence Number (non-decreasing)                |
    176  * +---------------+---------------+---------------+---------------+
    177  * |                      reserved must be zero                    |
    178  * +---------------+---------------+---------------+---------------+
    179  * |                      reserved must be zero                    |
    180  * +---------------+---------------+---------------+---------------+
    181  */
    182 struct rip_auth_crypto_v2 {
    183 	nd_uint16_t rip_packet_len;
    184 	nd_uint8_t  rip_key_id;
    185 	nd_uint8_t  rip_auth_data_len;
    186 	nd_uint32_t rip_seq_num;
    187 	nd_byte     rip_mbz1[4];
    188 	nd_byte     rip_mbz2[4];
    189 };
    190 
    191 static unsigned
    192 rip_entry_print_v1(netdissect_options *ndo, const u_char *p,
    193 		   unsigned remaining)
    194 {
    195 	const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
    196 	u_short family;
    197 	const struct rip_netinfo_v1 *ni = (const struct rip_netinfo_v1 *)p;
    198 
    199 	/* RFC 1058 */
    200 	if (remaining < RIP_ROUTELEN)
    201 		return (0);
    202 	ND_TCHECK_SIZE(ni);
    203 	family = GET_BE_U_2(ni->rip_family);
    204 	if (family != BSD_AFNUM_INET && family != 0) {
    205 		ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
    206 		print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
    207 		return (RIP_ROUTELEN);
    208 	}
    209 	if (GET_BE_U_2(ni->rip_mbz1) ||
    210 	    GET_BE_U_4(ni->rip_mbz2) ||
    211 	    GET_BE_U_4(ni->rip_mbz3)) {
    212 		/* MBZ fields not zero */
    213 		print_unknown_data(ndo, p, "\n\t  ", RIP_ROUTELEN);
    214 		return (RIP_ROUTELEN);
    215 	}
    216 	if (family == 0) {
    217 		ND_PRINT("\n\t  AFI 0, %s, metric: %u",
    218 			 GET_IPADDR_STRING(ni->rip_dest),
    219 			 GET_BE_U_4(ni->rip_metric));
    220 		return (RIP_ROUTELEN);
    221 	} /* BSD_AFNUM_INET */
    222 	ND_PRINT("\n\t  %s, metric: %u",
    223 		 GET_IPADDR_STRING(ni->rip_dest),
    224 		 GET_BE_U_4(ni->rip_metric));
    225 	return (RIP_ROUTELEN);
    226 trunc:
    227 	return 0;
    228 }
    229 
    230 UNALIGNED_OK
    231 static unsigned
    232 rip_entry_print_v2(netdissect_options *ndo, const u_char *p,
    233 		   unsigned remaining)
    234 {
    235 	const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
    236 	u_short family;
    237 	const struct rip_netinfo_v2 *ni;
    238 
    239 	if (remaining < sizeof(*eh))
    240 		return (0);
    241 	ND_TCHECK_SIZE(eh);
    242 	family = GET_BE_U_2(eh->rip_family);
    243 	if (family == 0xFFFF) { /* variable-sized authentication structures */
    244 		uint16_t auth_type = GET_BE_U_2(eh->rip_tag);
    245 
    246 		p += sizeof(*eh);
    247 		remaining -= sizeof(*eh);
    248 		if (auth_type == 2) {
    249 			ND_PRINT("\n\t  Simple Text Authentication data: ");
    250 			nd_printjnp(ndo, p, RIP_AUTHLEN);
    251 		} else if (auth_type == 3) {
    252 			const struct rip_auth_crypto_v2 *ch;
    253 
    254 			ch = (const struct rip_auth_crypto_v2 *)p;
    255 			ND_TCHECK_SIZE(ch);
    256 			if (remaining < sizeof(*ch))
    257 				return (0);
    258 			ND_PRINT("\n\t  Auth header:");
    259 			ND_PRINT(" Packet Len %u,",
    260 				 GET_BE_U_2(ch->rip_packet_len));
    261 			ND_PRINT(" Key-ID %u,", GET_U_1(ch->rip_key_id));
    262 			ND_PRINT(" Auth Data Len %u,",
    263 				 GET_U_1(ch->rip_auth_data_len));
    264 			ND_PRINT(" SeqNo %u,", GET_BE_U_4(ch->rip_seq_num));
    265 			ND_PRINT(" MBZ %u,", GET_BE_U_4(ch->rip_mbz1));
    266 			ND_PRINT(" MBZ %u", GET_BE_U_4(ch->rip_mbz2));
    267 		} else if (auth_type == 1) {
    268 			ND_PRINT("\n\t  Auth trailer:");
    269 			print_unknown_data(ndo, p, "\n\t  ", remaining);
    270 			return (sizeof(*eh) + remaining); /* AT spans till the packet end */
    271 		} else {
    272 			ND_PRINT("\n\t  Unknown (%u) Authentication data:",
    273 				 auth_type);
    274 			print_unknown_data(ndo, p, "\n\t  ", remaining);
    275 			return (sizeof(*eh) + remaining); /* we don't know how long this is, so we go to the packet end */
    276 		}
    277 	} else if (family != BSD_AFNUM_INET && family != 0) {
    278 		ND_PRINT("\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
    279 		print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
    280 	} else { /* BSD_AFNUM_INET or AFI 0 */
    281 		ni = (const struct rip_netinfo_v2 *)p;
    282 		ND_TCHECK_SIZE(ni);
    283 		if (remaining < sizeof(*ni))
    284 			return (0);
    285 		ND_PRINT("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
    286 			 tok2str(bsd_af_values, "%u", family),
    287 			 GET_IPADDR_STRING(ni->rip_dest),
    288 			 mask2plen(GET_BE_U_4(ni->rip_dest_mask)),
    289 			 GET_BE_U_2(ni->rip_tag),
    290 			 GET_BE_U_4(ni->rip_metric));
    291 		if (GET_BE_U_4(ni->rip_router))
    292 			ND_PRINT("%s", GET_IPADDR_STRING(ni->rip_router));
    293 		else
    294 			ND_PRINT("self");
    295 	}
    296 	return (RIP_ROUTELEN);
    297 trunc:
    298 	return 0;
    299 }
    300 
    301 void
    302 rip_print(netdissect_options *ndo,
    303 	  const u_char *dat, u_int length)
    304 {
    305 	const struct rip *rp;
    306 	uint8_t vers, cmd;
    307 	const u_char *p;
    308 	u_int len, routecount;
    309 	unsigned entry_size;
    310 
    311 	ndo->ndo_protocol = "rip";
    312 	if (ndo->ndo_snapend < dat) {
    313 		nd_print_trunc(ndo);
    314 		return;
    315 	}
    316 	len = ND_BYTES_AVAILABLE_AFTER(dat);
    317 	if (len > length)
    318 		len = length;
    319 	if (len < sizeof(*rp)) {
    320 		nd_print_trunc(ndo);
    321 		return;
    322 	}
    323 	len -= sizeof(*rp);
    324 
    325 	rp = (const struct rip *)dat;
    326 
    327 	ND_TCHECK_SIZE(rp);
    328 	vers = GET_U_1(rp->rip_vers);
    329 	ND_PRINT("%sRIPv%u",
    330 		 (ndo->ndo_vflag >= 1) ? "\n\t" : "",
    331 		 vers);
    332 
    333 	/* dump version and lets see if we know the commands name*/
    334 	cmd = GET_U_1(rp->rip_cmd);
    335 	ND_PRINT(", %s, length: %u",
    336 		tok2str(rip_cmd_values, "unknown command (%u)", cmd),
    337 		length);
    338 
    339 	if (ndo->ndo_vflag < 1)
    340 		return;
    341 
    342 	switch (cmd) {
    343 
    344 	case RIPCMD_REQUEST:
    345 	case RIPCMD_RESPONSE:
    346 		switch (vers) {
    347 
    348 		case 1:
    349 			routecount = length / RIP_ROUTELEN;
    350 			ND_PRINT(", routes: %u", routecount);
    351 			p = (const u_char *)(rp + 1);
    352 			while (len != 0) {
    353 				entry_size = rip_entry_print_v1(ndo, p, len);
    354 				if (entry_size == 0) {
    355 					/* Error */
    356 					nd_print_trunc(ndo);
    357 					break;
    358 				}
    359 				if (len < entry_size) {
    360 					ND_PRINT(" [remaining entries length %u < %u]",
    361 						 len, entry_size);
    362 					nd_print_invalid(ndo);
    363 					break;
    364 				}
    365 				p += entry_size;
    366 				len -= entry_size;
    367 			}
    368 			break;
    369 
    370 		case 2:
    371 			routecount = length / RIP_ROUTELEN;
    372 			ND_PRINT(", routes: %u or less", routecount);
    373 			p = (const u_char *)(rp + 1);
    374 			while (len != 0) {
    375 				entry_size = rip_entry_print_v2(ndo, p, len);
    376 				if (entry_size == 0) {
    377 					/* Error */
    378 					nd_print_trunc(ndo);
    379 					break;
    380 				}
    381 				if (len < entry_size) {
    382 					ND_PRINT(" [remaining entries length %u < %u]",
    383 						 len, entry_size);
    384 					nd_print_invalid(ndo);
    385 					break;
    386 				}
    387 				p += entry_size;
    388 				len -= entry_size;
    389 			}
    390 			break;
    391 
    392 		default:
    393 			ND_PRINT(", unknown version");
    394 			break;
    395 		}
    396 		break;
    397 
    398 	case RIPCMD_TRACEON:
    399 	case RIPCMD_TRACEOFF:
    400 	case RIPCMD_TRIGREQ:
    401 	case RIPCMD_TRIGRESP:
    402 	case RIPCMD_TRIGACK:
    403 	case RIPCMD_UPDREQ:
    404 	case RIPCMD_UPDRESP:
    405 	case RIPCMD_UPDACK:
    406 		break;
    407 
    408 	default:
    409 		if (ndo->ndo_vflag <= 1) {
    410 			if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
    411 				return;
    412 		}
    413 		break;
    414 	}
    415 	/* do we want to see an additionally hexdump ? */
    416 	if (ndo->ndo_vflag> 1) {
    417 		if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
    418 			return;
    419 	}
    420 trunc:
    421 	return;
    422 }
    423