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print-rip.c revision 1.7.12.1
      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 1.7.12.1 2020/04/08 14:04:14 martin Exp $");
     25 #endif
     26 
     27 /* \summary: Routing Information Protocol (RIP) printer */
     28 
     29 #ifdef HAVE_CONFIG_H
     30 #include "config.h"
     31 #endif
     32 
     33 #include <netdissect-stdinc.h>
     34 
     35 #include <stdio.h>
     36 
     37 #include "netdissect.h"
     38 #include "addrtoname.h"
     39 #include "extract.h"
     40 
     41 #include "af.h"
     42 
     43 static const char tstr[] = "[|rip]";
     44 
     45 struct rip {
     46 	uint8_t rip_cmd;		/* request/response */
     47 	uint8_t rip_vers;		/* protocol version # */
     48 	uint8_t unused[2];		/* unused */
     49 };
     50 
     51 #define	RIPCMD_REQUEST		1	/* want info */
     52 #define	RIPCMD_RESPONSE		2	/* responding to request */
     53 #define	RIPCMD_TRACEON		3	/* turn tracing on */
     54 #define	RIPCMD_TRACEOFF		4	/* turn it off */
     55 #define	RIPCMD_POLL		5	/* want info from everybody */
     56 #define	RIPCMD_POLLENTRY	6	/* poll for entry */
     57 
     58 static const struct tok rip_cmd_values[] = {
     59     { RIPCMD_REQUEST,	        "Request" },
     60     { RIPCMD_RESPONSE,	        "Response" },
     61     { RIPCMD_TRACEON,	        "Trace on" },
     62     { RIPCMD_TRACEOFF,	        "Trace off" },
     63     { RIPCMD_POLL,	        "Poll" },
     64     { RIPCMD_POLLENTRY,	        "Poll Entry" },
     65     { 0, NULL}
     66 };
     67 
     68 #define RIP_AUTHLEN  16
     69 #define RIP_ROUTELEN 20
     70 
     71 /*
     72  * rfc 1723
     73  *
     74  *  0                   1                   2                   3 3
     75  *  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
     76  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     77  * | Command (1)   | Version (1)   |           unused              |
     78  * +---------------+---------------+-------------------------------+
     79  * | Address Family Identifier (2) |        Route Tag (2)          |
     80  * +-------------------------------+-------------------------------+
     81  * |                         IP Address (4)                        |
     82  * +---------------------------------------------------------------+
     83  * |                         Subnet Mask (4)                       |
     84  * +---------------------------------------------------------------+
     85  * |                         Next Hop (4)                          |
     86  * +---------------------------------------------------------------+
     87  * |                         Metric (4)                            |
     88  * +---------------------------------------------------------------+
     89  *
     90  */
     91 
     92 struct rip_netinfo {
     93 	uint16_t rip_family;
     94 	uint16_t rip_tag;
     95 	uint32_t rip_dest;
     96 	uint32_t rip_dest_mask;
     97 	uint32_t rip_router;
     98 	uint32_t rip_metric;		/* cost of route */
     99 };
    100 
    101 UNALIGNED_OK
    102 static void
    103 rip_entry_print_v1(netdissect_options *ndo,
    104                    register const struct rip_netinfo *ni)
    105 {
    106 	register u_short family;
    107 
    108 	/* RFC 1058 */
    109 	family = EXTRACT_16BITS(&ni->rip_family);
    110 	if (family != BSD_AFNUM_INET && family != 0) {
    111 		ND_PRINT((ndo, "\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family)));
    112 		print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
    113 		return;
    114 	}
    115 	if (EXTRACT_16BITS(&ni->rip_tag) ||
    116 	    EXTRACT_32BITS(&ni->rip_dest_mask) ||
    117 	    EXTRACT_32BITS(&ni->rip_router)) {
    118 		/* MBZ fields not zero */
    119                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
    120 		return;
    121 	}
    122 	if (family == 0) {
    123 		ND_PRINT((ndo, "\n\t  AFI 0, %s, metric: %u",
    124 			ipaddr_string(ndo, &ni->rip_dest),
    125 			EXTRACT_32BITS(&ni->rip_metric)));
    126 		return;
    127 	} /* BSD_AFNUM_INET */
    128 	ND_PRINT((ndo, "\n\t  %s, metric: %u",
    129                ipaddr_string(ndo, &ni->rip_dest),
    130 	       EXTRACT_32BITS(&ni->rip_metric)));
    131 }
    132 
    133 UNALIGNED_OK
    134 static unsigned
    135 rip_entry_print_v2(netdissect_options *ndo,
    136                    register const struct rip_netinfo *ni, const unsigned remaining)
    137 {
    138 	register u_short family;
    139 
    140 	family = EXTRACT_16BITS(&ni->rip_family);
    141 	if (family == 0xFFFF) { /* variable-sized authentication structures */
    142 		uint16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
    143 		if (auth_type == 2) {
    144 			register const u_char *p = (const u_char *)&ni->rip_dest;
    145 			u_int i = 0;
    146 			ND_PRINT((ndo, "\n\t  Simple Text Authentication data: "));
    147 			for (; i < RIP_AUTHLEN; p++, i++)
    148 				ND_PRINT((ndo, "%c", ND_ISPRINT(*p) ? *p : '.'));
    149 		} else if (auth_type == 3) {
    150 			ND_PRINT((ndo, "\n\t  Auth header:"));
    151 			ND_PRINT((ndo, " Packet Len %u,", EXTRACT_16BITS((const uint8_t *)ni + 4)));
    152 			ND_PRINT((ndo, " Key-ID %u,", *((const uint8_t *)ni + 6)));
    153 			ND_PRINT((ndo, " Auth Data Len %u,", *((const uint8_t *)ni + 7)));
    154 			ND_PRINT((ndo, " SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask)));
    155 			ND_PRINT((ndo, " MBZ %u,", EXTRACT_32BITS(&ni->rip_router)));
    156 			ND_PRINT((ndo, " MBZ %u", EXTRACT_32BITS(&ni->rip_metric)));
    157 		} else if (auth_type == 1) {
    158 			ND_PRINT((ndo, "\n\t  Auth trailer:"));
    159 			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
    160 			return remaining; /* AT spans till the packet end */
    161 		} else {
    162 			ND_PRINT((ndo, "\n\t  Unknown (%u) Authentication data:",
    163 			       EXTRACT_16BITS(&ni->rip_tag)));
    164 			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
    165 		}
    166 	} else if (family != BSD_AFNUM_INET && family != 0) {
    167 		ND_PRINT((ndo, "\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family)));
    168                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
    169 	} else { /* BSD_AFNUM_INET or AFI 0 */
    170 		ND_PRINT((ndo, "\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
    171                        tok2str(bsd_af_values, "%u", family),
    172                        ipaddr_string(ndo, &ni->rip_dest),
    173 		       mask2plen(EXTRACT_32BITS(&ni->rip_dest_mask)),
    174                        EXTRACT_16BITS(&ni->rip_tag),
    175                        EXTRACT_32BITS(&ni->rip_metric)));
    176 		if (EXTRACT_32BITS(&ni->rip_router))
    177 			ND_PRINT((ndo, "%s", ipaddr_string(ndo, &ni->rip_router)));
    178 		else
    179 			ND_PRINT((ndo, "self"));
    180 	}
    181 	return sizeof (*ni);
    182 }
    183 
    184 void
    185 rip_print(netdissect_options *ndo,
    186           const u_char *dat, u_int length)
    187 {
    188 	register const struct rip *rp;
    189 	register const struct rip_netinfo *ni;
    190 	register u_int i, j;
    191 
    192 	if (ndo->ndo_snapend < dat) {
    193 		ND_PRINT((ndo, " %s", tstr));
    194 		return;
    195 	}
    196 	i = ndo->ndo_snapend - dat;
    197 	if (i > length)
    198 		i = length;
    199 	if (i < sizeof(*rp)) {
    200 		ND_PRINT((ndo, " %s", tstr));
    201 		return;
    202 	}
    203 	i -= sizeof(*rp);
    204 
    205 	rp = (const struct rip *)dat;
    206 
    207 	ND_PRINT((ndo, "%sRIPv%u",
    208                (ndo->ndo_vflag >= 1) ? "\n\t" : "",
    209                rp->rip_vers));
    210 
    211 	switch (rp->rip_vers) {
    212 	case 0:
    213 		/*
    214 		 * RFC 1058.
    215 		 *
    216 		 * XXX - RFC 1058 says
    217 		 *
    218 		 * 0  Datagrams whose version number is zero are to be ignored.
    219 		 *    These are from a previous version of the protocol, whose
    220 		 *    packet format was machine-specific.
    221 		 *
    222 		 * so perhaps we should just dump the packet, in hex.
    223 		 */
    224                 print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
    225 		break;
    226 	default:
    227                 /* dump version and lets see if we know the commands name*/
    228                 ND_PRINT((ndo, ", %s, length: %u",
    229                        tok2str(rip_cmd_values,
    230                                "unknown command (%u)",
    231                                rp->rip_cmd),
    232                        length));
    233 
    234                 if (ndo->ndo_vflag < 1)
    235                     return;
    236 
    237 		switch (rp->rip_cmd) {
    238 		case RIPCMD_REQUEST:
    239 		case RIPCMD_RESPONSE:
    240 			j = length / sizeof(*ni);
    241 			ND_PRINT((ndo, ", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : ""));
    242 			ni = (const struct rip_netinfo *)(rp + 1);
    243 			for (; i >= sizeof(*ni); ++ni) {
    244 				if (rp->rip_vers == 1)
    245 				{
    246 					rip_entry_print_v1(ndo, ni);
    247 					i -= sizeof(*ni);
    248 				}
    249 				else if (rp->rip_vers == 2)
    250 					i -= rip_entry_print_v2(ndo, ni, i);
    251                                 else
    252                                     break;
    253 			}
    254 			if (i)
    255 				ND_PRINT((ndo, "%s", tstr));
    256 			break;
    257 
    258 		case RIPCMD_TRACEOFF:
    259 		case RIPCMD_POLL:
    260 		case RIPCMD_POLLENTRY:
    261 			break;
    262 
    263 		case RIPCMD_TRACEON:
    264                     /* fall through */
    265 	        default:
    266                     if (ndo->ndo_vflag <= 1) {
    267                         if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
    268                             return;
    269                     }
    270                     break;
    271                 }
    272                 /* do we want to see an additionally hexdump ? */
    273                 if (ndo->ndo_vflag> 1) {
    274                     if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
    275                         return;
    276                 }
    277         }
    278 }
    279