X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/c422d3ab0f6de2d38512a4566637bc47df291e74..5ef0bcb5edd748de9d9af13c40da0395dfdd94e8:/print-cdp.c diff --git a/print-cdp.c b/print-cdp.c index 72f9ea85..0ab646e5 100644 --- a/print-cdp.c +++ b/print-cdp.c @@ -21,162 +21,271 @@ * Code by Gert Doering, SpaceNet GmbH, gert@space.net * * Reference documentation: - * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm + * https://web.archive.org/web/20000914194913/http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.pdf */ -#ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.17 2002-09-05 21:25:38 guy Exp $"; -#endif +/* \summary: Cisco Discovery Protocol (CDP) printer */ #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include +#include "netdissect-stdinc.h" -#include #include -#include "interface.h" +#include "netdissect.h" #include "addrtoname.h" -#include "extract.h" /* must come after interface.h */ - -static int cdp_print_addr(const u_char *, int); -static int cdp_print_prefixes(const u_char *, int); -static unsigned long cdp_get_number(const u_char *, int); +#include "extract.h" +#include "nlpid.h" + + +#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 assignment"}, + { 0x0f, "ATA-186 VoIP VLAN request"}, + { 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 *, u_int); +static int cdp_print_prefixes(netdissect_options *, const u_char *, u_int); +static unsigned int cdp_get_number(netdissect_options *, const u_char *, u_int); void -cdp_print(const u_char *p, u_int length, u_int caplen) +cdp_print(netdissect_options *ndo, + const u_char *pptr, u_int length, u_int caplen) { - u_int i; - int type, len; - - /* Cisco Discovery Protocol */ + u_int type, len, i; + const u_char *tptr; - if (caplen < 4) { - (void)printf("[|cdp]"); + ndo->ndo_protocol = "cdp"; + if (caplen < CDP_HEADER_LEN) { + nd_print_trunc(ndo); return; } - i = 0; /* CDP data starts at offset 0 */ - printf("CDP v%u, ttl=%us", p[i], p[i + 1]); - i += 4; /* skip version, TTL and chksum */ + tptr = pptr; /* temporary pointer */ + + ND_TCHECK_LEN(tptr, CDP_HEADER_LEN); + ND_PRINT("CDPv%u, ttl: %us", + GET_U_1((tptr + CDP_HEADER_VERSION_OFFSET)), + GET_U_1(tptr + CDP_HEADER_TTL_OFFSET)); + if (ndo->ndo_vflag) + ND_PRINT(", checksum: 0x%04x (unverified), length %u", + GET_BE_U_2(tptr + CDP_HEADER_CHECKSUM_OFFSET), + length); + tptr += CDP_HEADER_LEN; + + while (tptr < (pptr+length)) { + ND_TCHECK_LEN(tptr, CDP_TLV_HEADER_LEN); /* read out Type and Length */ + type = GET_BE_U_2(tptr + CDP_TLV_TYPE_OFFSET); + len = GET_BE_U_2(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("\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(", %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; - while (i < length) { - if (i + 4 > caplen) - goto trunc; - type = (p[i] << 8) + p[i + 1]; - len = (p[i + 2] << 8) + p[i + 3]; + ND_TCHECK_LEN(tptr, len); - if (vflag > 1) - printf("\n\t"); + if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */ - if (vflag) - printf(" %02x/%02x", type, len); + if (ndo->ndo_vflag) + ND_PRINT("\n\t%s (0x%02x), value length: %u byte%s: ", + tok2str(cdp_tlv_values,"unknown field type", type), + type, + len, + PLURAL_SUFFIX(len)); /* plural */ - if (i + len > caplen) - goto trunc; + switch (type) { - switch (type) { - case 0x00: - printf(" Goodbye"); + case 0x01: /* Device-ID */ + if (!ndo->ndo_vflag) + ND_PRINT(", Device-ID "); + ND_PRINT("'"); + (void)nd_printn(ndo, tptr, len, NULL); + ND_PRINT("'"); break; - case 0x01: - printf(" DevID '%.*s'", len - 4, p + i + 4); + case 0x02: /* Address */ + if (cdp_print_addr(ndo, tptr, len) < 0) + goto trunc; break; - case 0x02: - printf(" Addr"); - if (cdp_print_addr(p + i + 4, len - 4) < 0) - goto trunc; + case 0x03: /* Port-ID */ + ND_PRINT("'"); + (void)nd_printn(ndo, tptr, len, NULL); + ND_PRINT("'"); break; - case 0x03: - printf(" PortID '%.*s'", len - 4, p + i + 4); + case 0x04: /* Capabilities */ + if (len < 4) + goto trunc; + ND_PRINT("(0x%08x): %s", + GET_BE_U_4(tptr), + bittok2str(cdp_capability_values, "none", GET_BE_U_4(tptr))); break; - case 0x04: - printf(" CAP 0x%02x", (unsigned) p[i + 7]); + case 0x05: /* Version */ + ND_PRINT("\n\t "); + for (i=0;i 1) - printf(" Version:\n%.*s", len - 4, p + i + 4); - else - printf(" Version: (suppressed)"); + case 0x06: /* Platform */ + ND_PRINT("'"); + (void)nd_printn(ndo, tptr, len, NULL); + ND_PRINT("'"); break; - case 0x06: - printf(" Platform: '%.*s'", len - 4, p + i + 4); + case 0x07: /* Prefixes */ + if (cdp_print_prefixes(ndo, tptr, len) < 0) + goto trunc; break; - case 0x07: - if (cdp_print_prefixes(p + i + 4, len - 4) < 0) - goto trunc; + case 0x08: /* Protocol Hello Option - not documented */ break; - case 0x08: /* guess - not documented */ - printf(" Protocol-Hello option" ); + case 0x09: /* VTP Mgmt Domain - CDPv2 */ + ND_PRINT("'"); + (void)nd_printn(ndo, tptr, len, NULL); + ND_PRINT("'"); break; - case 0x09: /* guess - not documented */ - printf(" VTP Management Domain: '%.*s'", len - 4, - p + i + 4); + case 0x0a: /* Native VLAN ID - CDPv2 */ + if (len < 2) + goto trunc; + ND_PRINT("%u", GET_BE_U_2(tptr)); break; - case 0x0a: /* guess - not documented */ - printf(" Native VLAN ID: %d", - (p[i + 4] << 8) + p[i + 4 + 1] ); + case 0x0b: /* Duplex - CDPv2 */ + if (len < 1) + goto trunc; + ND_PRINT("%s", GET_U_1(tptr) ? "full": "half"); break; - case 0x0b: /* guess - not documented */ - printf(" Duplex: %s", p[i + 4] ? "full": "half"); - break; -/* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm - * plus more details from other sources - */ - case 0x0e: /* incomplete doc. */ - printf(" ATA-186 VoIP VLAN request, app %d, vlan %d", - p[i + 4], EXTRACT_16BITS(&p[i+4+1])); - break; - case 0x0f: /* incomplete doc. */ - printf(" ATA-186 VoIP VLAN assignment" ); + + /* https://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 + * + * There are apparently versions of the request with both + * 2 bytes and 3 bytes of value. The 3 bytes of value + * appear to be a 1-byte application type followed by a + * 2-byte VLAN ID; the 2 bytes of value are unknown + * (they're 0x20 0x00 in some captures I've seen; that + * is not a valid VLAN ID, as VLAN IDs are 12 bits). + * + * The replies all appear to be 3 bytes long. + */ + case 0x0e: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ + if (len < 3) + goto trunc; + ND_PRINT("app %u, vlan %u", GET_U_1(tptr), + GET_BE_U_2(tptr + 1)); break; - case 0x10: /* incomplete doc. */ - printf(" power consumption: %1.2fW", - cdp_get_number(p+i+4, len-4)/1000.0 ); + case 0x0f: /* ATA-186 VoIP VLAN request - incomplete doc. */ + if (len < 2) + goto trunc; + if (len == 2) + ND_PRINT("unknown 0x%04x", GET_BE_U_2(tptr)); + else + ND_PRINT("app %u, vlan %u", GET_U_1(tptr), + GET_BE_U_2(tptr + 1)); break; - case 0x11: /* guess - not documented */ - printf(" MTU %u bytes", EXTRACT_32BITS(&p[i+4])); + case 0x10: /* Power - not documented */ + ND_PRINT("%1.2fW", cdp_get_number(ndo, tptr, len) / 1000.0); break; - case 0x12: /* guess - not documented */ - printf(" AVVID trust bitmap 0x%02x", p[i+4] ); + case 0x11: /* MTU - not documented */ + if (len < 4) + goto trunc; + ND_PRINT("%u bytes", GET_BE_U_4(tptr)); break; - case 0x13: /* guess - not documented */ - printf(" AVVID untrusted ports CoS: 0x%02x", p[i+4]); + case 0x12: /* AVVID trust bitmap - not documented */ + if (len < 1) + goto trunc; + ND_PRINT("0x%02x", GET_U_1(tptr)); break; - case 0x14: /* guess - not documented */ - printf(" System Name: '%.*s'", len - 4, - p + i + 4); + case 0x13: /* AVVID untrusted port CoS - not documented */ + if (len < 1) + goto trunc; + ND_PRINT("0x%02x", GET_U_1(tptr)); break; - case 0x15: /* guess - not documented */ - printf(" System Object ID (not decoded) "); /* TODO */ + case 0x14: /* System Name - not documented */ + ND_PRINT("'"); + (void)nd_printn(ndo, tptr, len, NULL); + ND_PRINT("'"); break; - case 0x16: /* guess - not documented */ - printf(" Management Addresses: "); - if (cdp_print_addr(p + i + 4, len - 4) < 0) + case 0x16: /* System Object ID - not documented */ + if (cdp_print_addr(ndo, tptr, len) < 0) goto trunc; break; - case 0x17: /* guess - not documented */ - printf(" Physical Location: 0x%02x/%.*s", - p[i+4], len - 5, p + i + 5 ); + case 0x17: /* Physical Location - not documented */ + if (len < 1) + goto trunc; + ND_PRINT("0x%02x", GET_U_1(tptr)); + if (len > 1) { + ND_PRINT("/"); + (void)nd_printn(ndo, tptr + 1, len - 1, NULL); + } break; - default: - printf(" unknown field type %02x, len %d", type, len); + default: + print_unknown_data(ndo, tptr, "\n\t ", len); break; + } } - - /* avoid infinite loop */ - if (len == 0) - break; - i += len; + tptr = tptr+len; } + if (ndo->ndo_vflag < 1) + ND_PRINT(", length %u", caplen); return; - trunc: - printf("[|cdp]"); + nd_print_trunc(ndo); } /* @@ -191,33 +300,36 @@ trunc: #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */ static int -cdp_print_addr(const u_char * p, int l) +cdp_print_addr(netdissect_options *ndo, + const u_char * p, u_int l) { - int pt, pl, al, num; + u_int pt, pl, al, num; const u_char *endp = p + l; -#ifdef INET6 - static u_char prot_ipv6[] = { + static const u_char prot_ipv6[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd }; -#endif - num = EXTRACT_32BITS(p); + ND_TCHECK_4(p); + if (p + 4 > endp) + goto trunc; + num = GET_BE_U_4(p); p += 4; - printf(" (%d): ", num); - - while (p < endp && num >= 0) { + while (p < endp && num != 0) { + ND_TCHECK_2(p); if (p + 2 > endp) goto trunc; - pt = p[0]; /* type of "protocol" field */ - pl = p[1]; /* length of "protocol" field */ + pt = GET_U_1(p); /* type of "protocol" field */ + pl = GET_U_1(p + 1); /* length of "protocol" field */ p += 2; + ND_TCHECK_2(p + pl); if (p + pl + 2 > endp) goto trunc; - al = EXTRACT_16BITS(&p[pl]); /* address length */ + al = GET_BE_U_2(p + pl); /* address length */ - if (pt == PT_NLPID && pl == 1 && *p == 0xcc && al == 4) { + if (pt == PT_NLPID && pl == 1 && GET_U_1(p) == NLPID_IP && + al == 4) { /* * IPv4: protocol type = NLPID, protocol length = 1 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4), @@ -227,10 +339,9 @@ cdp_print_addr(const u_char * p, int l) if (p + 4 > endp) goto trunc; - printf("IPv4 %u.%u.%u.%u", p[0], p[1], p[2], p[3]); + ND_PRINT("IPv4 (%u) %s", num, GET_IPADDR_STRING(p)); p += 4; } -#ifdef INET6 else if (pt == PT_IEEE_802_2 && pl == 8 && memcmp(p, prot_ipv6, 8) == 0 && al == 16) { /* @@ -240,35 +351,44 @@ cdp_print_addr(const u_char * p, int l) * Ethertype, address length = 16 */ p += 10; + ND_TCHECK_LEN(p, al); if (p + al > endp) goto trunc; - printf("IPv6 %s", ip6addr_string(p)); + ND_PRINT("IPv6 (%u) %s", num, GET_IP6ADDR_STRING(p)); p += al; } -#endif else { /* * Generic case: just print raw data */ + ND_TCHECK_LEN(p, pl); if (p + pl > endp) goto trunc; - printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl); - while (pl-- > 0) - printf(" %02x", *p++); + ND_PRINT("pt=0x%02x, pl=%u, pb=", GET_U_1((p - 2)), + pl); + while (pl != 0) { + ND_PRINT(" %02x", GET_U_1(p)); + p++; + pl--; + } + ND_TCHECK_2(p); if (p + 2 > endp) goto trunc; - al = (*p << 8) + *(p + 1); - printf(", al=%d, a=", al); + ND_PRINT(", al=%u, a=", al); p += 2; + ND_TCHECK_LEN(p, al); if (p + al > endp) goto trunc; - while (al-- > 0) - printf(" %02x", *p++); + while (al != 0) { + ND_PRINT(" %02x", GET_U_1(p)); + p++; + al--; + } } num--; if (num) - printf(" "); + ND_PRINT(" "); } return 0; @@ -279,15 +399,18 @@ trunc: static int -cdp_print_prefixes(const u_char * p, int l) +cdp_print_prefixes(netdissect_options *ndo, + const u_char * p, u_int l) { if (l % 5) goto trunc; - printf(" IPv4 Prefixes (%d):", l / 5); + ND_PRINT(" IPv4 Prefixes (%u):", l / 5); while (l > 0) { - printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]); + ND_PRINT(" %u.%u.%u.%u/%u", + GET_U_1(p), GET_U_1(p + 1), GET_U_1(p + 2), + GET_U_1(p + 3), GET_U_1(p + 4)); l -= 5; p += 5; } @@ -299,14 +422,15 @@ trunc: } /* read in a -byte number, MSB first - * (of course this can handle max sizeof(long)) + * (of course this can handle max sizeof(int)) */ -static unsigned long cdp_get_number(const u_char * p, int l) +static unsigned int +cdp_get_number(netdissect_options *ndo, const u_char * p, u_int l) { - unsigned long res=0; + unsigned int res=0; while( l>0 ) { - res = (res<<8) + *p; + res = (res<<8) + GET_U_1(p); p++; l--; } return res;