diff options
Diffstat (limited to 'print-cdp.c')
| -rw-r--r-- | print-cdp.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/print-cdp.c b/print-cdp.c new file mode 100644 index 000000000000..6f8f356736fe --- /dev/null +++ b/print-cdp.c @@ -0,0 +1,404 @@ +/* + * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997 + * The Regents of the University of California. All rights reserved. + * + * 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, (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, and (3) all advertising materials mentioning + * features or use of this software display the following acknowledgement: + * ``This product includes software developed by the University of California, + * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of + * the University nor the names of its contributors may be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * 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. + * + * Code by Gert Doering, SpaceNet GmbH, gert@space.net + * + * Reference documentation: + * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm + */ + +/* \summary: Cisco Discovery Protocol (CDP) printer */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <netdissect-stdinc.h> + +#include <string.h> + +#include "netdissect.h" +#include "addrtoname.h" +#include "extract.h" +#include "nlpid.h" + +static const char tstr[] = "[|cdp]"; + +#define CDP_HEADER_LEN 4 +#define CDP_HEADER_VERSION_OFFSET 0 +#define CDP_HEADER_TTL_OFFSET 1 +#define CDP_HEADER_CHECKSUM_OFFSET 2 + +#define CDP_TLV_HEADER_LEN 4 +#define CDP_TLV_TYPE_OFFSET 0 +#define CDP_TLV_LEN_OFFSET 2 + +static const struct tok cdp_tlv_values[] = { + { 0x01, "Device-ID"}, + { 0x02, "Address"}, + { 0x03, "Port-ID"}, + { 0x04, "Capability"}, + { 0x05, "Version String"}, + { 0x06, "Platform"}, + { 0x07, "Prefixes"}, + { 0x08, "Protocol-Hello option"}, + { 0x09, "VTP Management Domain"}, + { 0x0a, "Native VLAN ID"}, + { 0x0b, "Duplex"}, + { 0x0e, "ATA-186 VoIP VLAN request"}, + { 0x0f, "ATA-186 VoIP VLAN assignment"}, + { 0x10, "power consumption"}, + { 0x11, "MTU"}, + { 0x12, "AVVID trust bitmap"}, + { 0x13, "AVVID untrusted ports CoS"}, + { 0x14, "System Name"}, + { 0x15, "System Object ID (not decoded)"}, + { 0x16, "Management Addresses"}, + { 0x17, "Physical Location"}, + { 0, NULL} +}; + +static const struct tok cdp_capability_values[] = { + { 0x01, "Router" }, + { 0x02, "Transparent Bridge" }, + { 0x04, "Source Route Bridge" }, + { 0x08, "L2 Switch" }, + { 0x10, "L3 capable" }, + { 0x20, "IGMP snooping" }, + { 0x40, "L1 capable" }, + { 0, NULL } +}; + +static int cdp_print_addr(netdissect_options *, const u_char *, int); +static int cdp_print_prefixes(netdissect_options *, const u_char *, int); +static unsigned long cdp_get_number(const u_char *, int); + +void +cdp_print(netdissect_options *ndo, + const u_char *pptr, u_int length, u_int caplen) +{ + int type, len, i, j; + const u_char *tptr; + + if (caplen < CDP_HEADER_LEN) { + ND_PRINT((ndo, "%s", tstr)); + return; + } + + tptr = pptr; /* temporary pointer */ + + ND_TCHECK2(*tptr, CDP_HEADER_LEN); + ND_PRINT((ndo, "CDPv%u, ttl: %us", *(tptr + CDP_HEADER_VERSION_OFFSET), + *(tptr + CDP_HEADER_TTL_OFFSET))); + if (ndo->ndo_vflag) + ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_16BITS(tptr+CDP_HEADER_CHECKSUM_OFFSET), length)); + tptr += CDP_HEADER_LEN; + + while (tptr < (pptr+length)) { + ND_TCHECK2(*tptr, CDP_TLV_HEADER_LEN); /* read out Type and Length */ + type = EXTRACT_16BITS(tptr+CDP_TLV_TYPE_OFFSET); + len = EXTRACT_16BITS(tptr+CDP_TLV_LEN_OFFSET); /* object length includes the 4 bytes header length */ + if (len < CDP_TLV_HEADER_LEN) { + if (ndo->ndo_vflag) + ND_PRINT((ndo, "\n\t%s (0x%02x), TLV length: %u byte%s (too short)", + tok2str(cdp_tlv_values,"unknown field type", type), + type, + len, + PLURAL_SUFFIX(len))); /* plural */ + else + ND_PRINT((ndo, ", %s TLV length %u too short", + tok2str(cdp_tlv_values,"unknown field type", type), + len)); + break; + } + tptr += CDP_TLV_HEADER_LEN; + len -= CDP_TLV_HEADER_LEN; + + ND_TCHECK2(*tptr, len); + + if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */ + + if (ndo->ndo_vflag) + ND_PRINT((ndo, "\n\t%s (0x%02x), value length: %u byte%s: ", + tok2str(cdp_tlv_values,"unknown field type", type), + type, + len, + PLURAL_SUFFIX(len))); /* plural */ + + switch (type) { + + case 0x01: /* Device-ID */ + if (!ndo->ndo_vflag) + ND_PRINT((ndo, ", Device-ID ")); + ND_PRINT((ndo, "'")); + (void)fn_printn(ndo, tptr, len, NULL); + ND_PRINT((ndo, "'")); + break; + case 0x02: /* Address */ + if (cdp_print_addr(ndo, tptr, len) < 0) + goto trunc; + break; + case 0x03: /* Port-ID */ + ND_PRINT((ndo, "'")); + (void)fn_printn(ndo, tptr, len, NULL); + ND_PRINT((ndo, "'")); + break; + case 0x04: /* Capabilities */ + if (len < 4) + goto trunc; + ND_PRINT((ndo, "(0x%08x): %s", + EXTRACT_32BITS(tptr), + bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr)))); + break; + case 0x05: /* Version */ + ND_PRINT((ndo, "\n\t ")); + for (i=0;i<len;i++) { + j = *(tptr+i); + if (j == '\n') /* lets rework the version string to + get a nice indentation */ + ND_PRINT((ndo, "\n\t ")); + else + fn_print_char(ndo, j); + } + break; + case 0x06: /* Platform */ + ND_PRINT((ndo, "'")); + (void)fn_printn(ndo, tptr, len, NULL); + ND_PRINT((ndo, "'")); + break; + case 0x07: /* Prefixes */ + if (cdp_print_prefixes(ndo, tptr, len) < 0) + goto trunc; + break; + case 0x08: /* Protocol Hello Option - not documented */ + break; + case 0x09: /* VTP Mgmt Domain - CDPv2 */ + ND_PRINT((ndo, "'")); + (void)fn_printn(ndo, tptr, len, NULL); + ND_PRINT((ndo, "'")); + break; + case 0x0a: /* Native VLAN ID - CDPv2 */ + if (len < 2) + goto trunc; + ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr))); + break; + case 0x0b: /* Duplex - CDPv2 */ + if (len < 1) + goto trunc; + ND_PRINT((ndo, "%s", *(tptr) ? "full": "half")); + break; + + /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html + * plus more details from other sources + */ + case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */ + if (len < 3) + goto trunc; + ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1))); + break; + case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ + ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0)); + break; + case 0x11: /* MTU - not documented */ + if (len < 4) + goto trunc; + ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr))); + break; + case 0x12: /* AVVID trust bitmap - not documented */ + if (len < 1) + goto trunc; + ND_PRINT((ndo, "0x%02x", *(tptr))); + break; + case 0x13: /* AVVID untrusted port CoS - not documented */ + if (len < 1) + goto trunc; + ND_PRINT((ndo, "0x%02x", *(tptr))); + break; + case 0x14: /* System Name - not documented */ + ND_PRINT((ndo, "'")); + (void)fn_printn(ndo, tptr, len, NULL); + ND_PRINT((ndo, "'")); + break; + case 0x16: /* System Object ID - not documented */ + if (cdp_print_addr(ndo, tptr, len) < 0) + goto trunc; + break; + case 0x17: /* Physical Location - not documented */ + if (len < 1) + goto trunc; + ND_PRINT((ndo, "0x%02x", *(tptr))); + if (len > 1) { + ND_PRINT((ndo, "/")); + (void)fn_printn(ndo, tptr + 1, len - 1, NULL); + } + break; + default: + print_unknown_data(ndo, tptr, "\n\t ", len); + break; + } + } + tptr = tptr+len; + } + if (ndo->ndo_vflag < 1) + ND_PRINT((ndo, ", length %u", caplen)); + + return; +trunc: + ND_PRINT((ndo, "%s", tstr)); +} + +/* + * Protocol type values. + * + * PT_NLPID means that the protocol type field contains an OSI NLPID. + * + * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2 + * LLC header that specifies that the payload is for that protocol. + */ +#define PT_NLPID 1 /* OSI NLPID */ +#define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */ + +static int +cdp_print_addr(netdissect_options *ndo, + const u_char * p, int l) +{ + int pt, pl, al, num; + const u_char *endp = p + l; + static const u_char prot_ipv6[] = { + 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd + }; + + ND_TCHECK2(*p, 4); + if (p + 4 > endp) + goto trunc; + num = EXTRACT_32BITS(p); + p += 4; + + while (p < endp && num >= 0) { + ND_TCHECK2(*p, 2); + if (p + 2 > endp) + goto trunc; + pt = p[0]; /* type of "protocol" field */ + pl = p[1]; /* length of "protocol" field */ + p += 2; + + ND_TCHECK2(p[pl], 2); + if (p + pl + 2 > endp) + goto trunc; + al = EXTRACT_16BITS(&p[pl]); /* address length */ + + if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) { + /* + * IPv4: protocol type = NLPID, protocol length = 1 + * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4), + * address length = 4 + */ + p += 3; + + ND_TCHECK2(*p, 4); + if (p + 4 > endp) + goto trunc; + ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p))); + p += 4; + } + else if (pt == PT_IEEE_802_2 && pl == 8 && + memcmp(p, prot_ipv6, 8) == 0 && al == 16) { + /* + * IPv6: protocol type = IEEE 802.2 header, + * protocol length = 8 (size of LLC+SNAP header), + * protocol = LLC+SNAP header with the IPv6 + * Ethertype, address length = 16 + */ + p += 10; + ND_TCHECK2(*p, al); + if (p + al > endp) + goto trunc; + + ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p))); + p += al; + } + else { + /* + * Generic case: just print raw data + */ + ND_TCHECK2(*p, pl); + if (p + pl > endp) + goto trunc; + ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl)); + while (pl-- > 0) + ND_PRINT((ndo, " %02x", *p++)); + ND_TCHECK2(*p, 2); + if (p + 2 > endp) + goto trunc; + al = (*p << 8) + *(p + 1); + ND_PRINT((ndo, ", al=%d, a=", al)); + p += 2; + ND_TCHECK2(*p, al); + if (p + al > endp) + goto trunc; + while (al-- > 0) + ND_PRINT((ndo, " %02x", *p++)); + } + num--; + if (num) + ND_PRINT((ndo, " ")); + } + + return 0; + +trunc: + return -1; +} + + +static int +cdp_print_prefixes(netdissect_options *ndo, + const u_char * p, int l) +{ + if (l % 5) + goto trunc; + + ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5)); + + while (l > 0) { + ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4])); + l -= 5; + p += 5; + } + + return 0; + +trunc: + return -1; +} + +/* read in a <n>-byte number, MSB first + * (of course this can handle max sizeof(long)) + */ +static unsigned long cdp_get_number(const u_char * p, int l) +{ + unsigned long res=0; + while( l>0 ) + { + res = (res<<8) + *p; + p++; l--; + } + return res; +} |