Home | History | Annotate | Download | only in tcpdump
      1 /*
      2  * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
      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  * Code by Gert Doering, SpaceNet GmbH, gert (at) space.net
     22  *
     23  * Reference documentation:
     24  *    http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
     25  */
     26 
     27 #ifndef lint
     28 static const char rcsid[] _U_ =
     29     "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.25 2004/10/07 14:53:11 hannes Exp $";
     30 #endif
     31 
     32 #ifdef HAVE_CONFIG_H
     33 #include "config.h"
     34 #endif
     35 
     36 #include <tcpdump-stdinc.h>
     37 
     38 #include <stdio.h>
     39 #include <string.h>
     40 
     41 #include "interface.h"
     42 #include "addrtoname.h"
     43 #include "extract.h"			/* must come after interface.h */
     44 #include "nlpid.h"
     45 
     46 #define CDP_HEADER_LEN  4
     47 
     48 static struct tok cdp_tlv_values[] = {
     49     { 0x01,             "Device-ID"},
     50     { 0x02,             "Address"},
     51     { 0x03,             "Port-ID"},
     52     { 0x04,             "Capability"},
     53     { 0x05,             "Version String"},
     54     { 0x06,             "Platform"},
     55     { 0x07,             "Prefixes"},
     56     { 0x08,             "Protocol-Hello option"},
     57     { 0x09,             "VTP Management Domain"},
     58     { 0x0a,             "Native VLAN ID"},
     59     { 0x0b,             "Duplex"},
     60     { 0x0e,             "ATA-186 VoIP VLAN request"},
     61     { 0x0f,             "ATA-186 VoIP VLAN assignment"},
     62     { 0x10,             "power consumption"},
     63     { 0x11,             "MTU"},
     64     { 0x12,             "AVVID trust bitmap"},
     65     { 0x13,             "AVVID untrusted ports CoS"},
     66     { 0x14,             "System Name"},
     67     { 0x15,             "System Object ID (not decoded)"},
     68     { 0x16,             "Management Addresses"},
     69     { 0x17,             "Physical Location"},
     70     { 0, NULL}
     71 };
     72 
     73 static struct tok cdp_capability_values[] = {
     74     { 0x01,             "Router" },
     75     { 0x02,             "Transparent Bridge" },
     76     { 0x04,             "Source Route Bridge" },
     77     { 0x08,             "L2 Switch" },
     78     { 0x10,             "L3 capable" },
     79     { 0x20,             "IGMP snooping" },
     80     { 0x40,             "L1 capable" },
     81     { 0, NULL }
     82 };
     83 
     84 static int cdp_print_addr(const u_char *, int);
     85 static int cdp_print_prefixes(const u_char *, int);
     86 static unsigned long cdp_get_number(const u_char *, int);
     87 
     88 void
     89 cdp_print(const u_char *pptr, u_int length, u_int caplen)
     90 {
     91 	int type, len, i, j;
     92         const u_char *tptr;
     93 
     94 	if (caplen < CDP_HEADER_LEN) {
     95 		(void)printf("[|cdp]");
     96 		return;
     97 	}
     98 
     99         tptr = pptr; /* temporary pointer */
    100 
    101         if (!TTEST2(*tptr, CDP_HEADER_LEN))
    102                 goto trunc;
    103 	printf("CDPv%u, ttl: %us", *tptr, *(tptr+1));
    104         if (vflag)
    105                 printf(", checksum: %u (unverified), length %u", EXTRACT_16BITS(tptr), length);
    106 	tptr += CDP_HEADER_LEN;
    107 
    108 	while (tptr < (pptr+length)) {
    109 
    110                 if (!TTEST2(*tptr, 4)) /* read out Type and Length */
    111                     goto trunc;
    112 		type = EXTRACT_16BITS(tptr);
    113 		len  = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */
    114                 tptr += 4;
    115                 len -= 4;
    116 
    117 		if (!TTEST2(*tptr, len))
    118 			goto trunc;
    119 
    120                 if (vflag || type == 1) { /* in non-verbose mode just print Device-ID */
    121 
    122                     if (vflag)
    123                         printf("\n\t%s (0x%02x), length: %u byte%s: ",
    124                                tok2str(cdp_tlv_values,"unknown field type", type),
    125                                type,
    126                                len,
    127                                len>1 ? "s" : ""); /* plural */
    128 
    129                     switch (type) {
    130 
    131                     case 0x01: /* Device-ID */
    132                         if (!vflag)
    133                             printf(", Device-ID '%.*s'", len, tptr);
    134                         else
    135                             printf("'%.*s'", len, tptr);
    136 			break;
    137                     case 0x02: /* Address */
    138                         if (cdp_print_addr(tptr, len) < 0)
    139                             goto trunc;
    140 			break;
    141                     case 0x03: /* Port-ID */
    142 			printf("'%.*s'", len, tptr);
    143 			break;
    144                     case 0x04: /* Capabilities */
    145 			printf("(0x%08x): %s",
    146                                EXTRACT_32BITS(tptr),
    147                                bittok2str(cdp_capability_values, "none",EXTRACT_32BITS(tptr)));
    148 			break;
    149                     case 0x05: /* Version */
    150                         printf("\n\t  ");
    151                         for (i=0;i<len;i++) {
    152                             j = *(tptr+i);
    153                             putchar(j);
    154                             if (j == 0x0a) /* lets rework the version string to get a nice identation */
    155                                 printf("\t  ");
    156                         }
    157 			break;
    158                     case 0x06: /* Platform */
    159 			printf("'%.*s'", len, tptr);
    160 			break;
    161                     case 0x07: /* Prefixes */
    162 			if (cdp_print_prefixes(tptr, len) < 0)
    163                             goto trunc;
    164 			break;
    165                     case 0x08: /* Protocol Hello Option - not documented */
    166 			break;
    167                     case 0x09: /* VTP Mgmt Domain  - not documented */
    168 			printf("'%.*s'", len,tptr);
    169 			break;
    170                     case 0x0a: /* Native VLAN ID - not documented */
    171 			printf("%d",EXTRACT_16BITS(tptr));
    172 			break;
    173                     case 0x0b: /* Duplex - not documented */
    174 			printf("%s", *(tptr) ? "full": "half");
    175 			break;
    176 
    177                     /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
    178                      * plus more details from other sources
    179                      */
    180                     case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
    181 			printf("app %d, vlan %d",
    182                                *(tptr), EXTRACT_16BITS(tptr+1));
    183 			break;
    184                     case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
    185 			printf("%1.2fW",
    186                                cdp_get_number(tptr, len)/1000.0 );
    187 			break;
    188                     case 0x11: /* MTU - not documented */
    189 			printf("%u bytes", EXTRACT_32BITS(tptr));
    190 			break;
    191                     case 0x12: /* AVVID trust bitmap - not documented */
    192 			printf("0x%02x", *(tptr) );
    193 			break;
    194                     case 0x13: /* AVVID untrusted port CoS - not documented */
    195 			printf("0x%02x", *(tptr));
    196 			break;
    197                     case 0x14: /* System Name - not documented */
    198 			printf("'%.*s'", len, tptr);
    199 			break;
    200                     case 0x16: /* System Object ID - not documented */
    201 			if (cdp_print_addr(tptr, len) < 0)
    202 				goto trunc;
    203 			break;
    204                     case 0x17: /* Physical Location - not documented */
    205 			printf("0x%02x/%.*s", *(tptr), len - 1, tptr + 1 );
    206 			break;
    207                     default:
    208                         print_unknown_data(tptr,"\n\t  ",len);
    209 			break;
    210                     }
    211                 }
    212 		/* avoid infinite loop */
    213 		if (len == 0)
    214 			break;
    215 		tptr = tptr+len;
    216 	}
    217         if (vflag < 1)
    218             printf(", length %u",caplen);
    219 
    220 	return;
    221 trunc:
    222 	printf("[|cdp]");
    223 }
    224 
    225 /*
    226  * Protocol type values.
    227  *
    228  * PT_NLPID means that the protocol type field contains an OSI NLPID.
    229  *
    230  * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
    231  * LLC header that specifies that the payload is for that protocol.
    232  */
    233 #define PT_NLPID		1	/* OSI NLPID */
    234 #define PT_IEEE_802_2		2	/* IEEE 802.2 LLC header */
    235 
    236 static int
    237 cdp_print_addr(const u_char * p, int l)
    238 {
    239 	int pt, pl, al, num;
    240 	const u_char *endp = p + l;
    241 #ifdef INET6
    242 	static u_char prot_ipv6[] = {
    243 		0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
    244 	};
    245 #endif
    246 
    247 	TCHECK2(*p, 2);
    248 	num = EXTRACT_32BITS(p);
    249 	p += 4;
    250 
    251 	while (p < endp && num >= 0) {
    252 		TCHECK2(*p, 2);
    253 		if (p + 2 > endp)
    254 			goto trunc;
    255 		pt = p[0];		/* type of "protocol" field */
    256 		pl = p[1];		/* length of "protocol" field */
    257 		p += 2;
    258 
    259 		TCHECK2(p[pl], 2);
    260 		if (p + pl + 2 > endp)
    261 			goto trunc;
    262 		al = EXTRACT_16BITS(&p[pl]);	/* address length */
    263 
    264 		if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
    265 			/*
    266 			 * IPv4: protocol type = NLPID, protocol length = 1
    267 			 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
    268 			 * address length = 4
    269 			 */
    270 			p += 3;
    271 
    272 			TCHECK2(*p, 4);
    273 			if (p + 4 > endp)
    274 				goto trunc;
    275 			printf("IPv4 (%u) %s",
    276                                num,
    277                                ipaddr_string(p));
    278 			p += 4;
    279 		}
    280 #ifdef INET6
    281 		else if (pt == PT_IEEE_802_2 && pl == 8 &&
    282 		    memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
    283 			/*
    284 			 * IPv6: protocol type = IEEE 802.2 header,
    285 			 * protocol length = 8 (size of LLC+SNAP header),
    286 			 * protocol = LLC+SNAP header with the IPv6
    287 			 * Ethertype, address length = 16
    288 			 */
    289 			p += 10;
    290 			TCHECK2(*p, al);
    291 			if (p + al > endp)
    292 				goto trunc;
    293 
    294 			printf("IPv6 (%u) %s",
    295                                num,
    296                                ip6addr_string(p));
    297 			p += al;
    298 		}
    299 #endif
    300 		else {
    301 			/*
    302 			 * Generic case: just print raw data
    303 			 */
    304 			TCHECK2(*p, pl);
    305 			if (p + pl > endp)
    306 				goto trunc;
    307 			printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
    308 			while (pl-- > 0)
    309 				printf(" %02x", *p++);
    310 			TCHECK2(*p, 2);
    311 			if (p + 2 > endp)
    312 				goto trunc;
    313 			al = (*p << 8) + *(p + 1);
    314 			printf(", al=%d, a=", al);
    315 			p += 2;
    316 			TCHECK2(*p, al);
    317 			if (p + al > endp)
    318 				goto trunc;
    319 			while (al-- > 0)
    320 				printf(" %02x", *p++);
    321 		}
    322 		num--;
    323 		if (num)
    324 			printf(" ");
    325 	}
    326 
    327 	return 0;
    328 
    329 trunc:
    330 	return -1;
    331 }
    332 
    333 
    334 static int
    335 cdp_print_prefixes(const u_char * p, int l)
    336 {
    337 	if (l % 5)
    338 		goto trunc;
    339 
    340 	printf(" IPv4 Prefixes (%d):", l / 5);
    341 
    342 	while (l > 0) {
    343 		printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
    344 		l -= 5;
    345 		p += 5;
    346 	}
    347 
    348 	return 0;
    349 
    350 trunc:
    351 	return -1;
    352 }
    353 
    354 /* read in a <n>-byte number, MSB first
    355  * (of course this can handle max sizeof(long))
    356  */
    357 static unsigned long cdp_get_number(const u_char * p, int l)
    358 {
    359     unsigned long res=0;
    360     while( l>0 )
    361     {
    362 	res = (res<<8) + *p;
    363 	p++; l--;
    364     }
    365     return res;
    366 }
    367