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