diff options
Diffstat (limited to 'contrib/tcpdump/print-cdp.c')
| -rw-r--r-- | contrib/tcpdump/print-cdp.c | 596 |
1 files changed, 332 insertions, 264 deletions
diff --git a/contrib/tcpdump/print-cdp.c b/contrib/tcpdump/print-cdp.c index 6f8f356736fe..9f5c24bca6bd 100644 --- a/contrib/tcpdump/print-cdp.c +++ b/contrib/tcpdump/print-cdp.c @@ -21,25 +21,25 @@ * 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 */ /* \summary: Cisco Discovery Protocol (CDP) printer */ #ifdef HAVE_CONFIG_H -#include "config.h" +#include <config.h> #endif -#include <netdissect-stdinc.h> +#include "netdissect-stdinc.h" #include <string.h> +#define ND_LONGJMP_FROM_TCHECK #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 @@ -50,31 +50,6 @@ static const char tstr[] = "[|cdp]"; #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" }, @@ -86,182 +61,268 @@ static const struct tok cdp_capability_values[] = { { 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); +static void cdp_print_addr(netdissect_options *, const u_char *, u_int); +static void cdp_print_prefixes(netdissect_options *, const u_char *, u_int); -void -cdp_print(netdissect_options *ndo, - const u_char *pptr, u_int length, u_int caplen) +static void +cdp_print_string(netdissect_options *ndo, + const u_char *cp, const u_int len) { - int type, len, i, j; - const u_char *tptr; + ND_PRINT("'"); + (void)nd_printn(ndo, cp, len, NULL); + ND_PRINT("'"); +} - if (caplen < CDP_HEADER_LEN) { - ND_PRINT((ndo, "%s", tstr)); - return; +static void +cdp_print_power(netdissect_options *ndo, + const u_char *cp, const u_int len) +{ + u_int val = 0; + + switch (len) { + case 1: + val = GET_U_1(cp); + break; + case 2: + val = GET_BE_U_2(cp); + break; + case 3: + val = GET_BE_U_3(cp); + break; } + ND_PRINT("%1.2fW", val / 1000.0); +} - tptr = pptr; /* temporary pointer */ +static void +cdp_print_capability(netdissect_options *ndo, + const u_char *cp, const u_int len _U_) +{ + uint32_t val = GET_BE_U_4(cp); + + ND_PRINT("(0x%08x): %s", val, + bittok2str(cdp_capability_values, "none", val)); +} + +/* Rework the version string to get a nice indentation. */ +static void +cdp_print_version(netdissect_options *ndo, + const u_char *cp, const u_int len) +{ + unsigned i; + + ND_PRINT("\n\t "); + for (i = 0; i < len; i++) { + u_char c = GET_U_1(cp + i); + + if (c == '\n') + ND_PRINT("\n\t "); + else + fn_print_char(ndo, c); + } +} + +static void +cdp_print_uint16(netdissect_options *ndo, + const u_char *cp, const u_int len _U_) +{ + ND_PRINT("%u", GET_BE_U_2(cp)); +} + +static void +cdp_print_duplex(netdissect_options *ndo, + const u_char *cp, const u_int len _U_) +{ + ND_PRINT("%s", GET_U_1(cp) ? "full": "half"); +} + +/* 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. +*/ +static void +cdp_print_ata186(netdissect_options *ndo, + const u_char *cp, const u_int len) +{ + if (len == 2) + ND_PRINT("unknown 0x%04x", GET_BE_U_2(cp)); + else + ND_PRINT("app %u, vlan %u", GET_U_1(cp), GET_BE_U_2(cp + 1)); +} + +static void +cdp_print_mtu(netdissect_options *ndo, + const u_char *cp, const u_int len _U_) +{ + ND_PRINT("%u bytes", GET_BE_U_4(cp)); +} + +static void +cdp_print_uint8x(netdissect_options *ndo, + const u_char *cp, const u_int len _U_) +{ + ND_PRINT("0x%02x", GET_U_1(cp)); +} + +static void +cdp_print_phys_loc(netdissect_options *ndo, + const u_char *cp, const u_int len) +{ + ND_PRINT("0x%02x", GET_U_1(cp)); + if (len > 1) { + ND_PRINT("/"); + (void)nd_printn(ndo, cp + 1, len - 1, NULL); + } +} + +struct cdp_tlvinfo { + const char *name; + void (*printer)(netdissect_options *ndo, const u_char *, u_int); + int min_len, max_len; +}; - ND_TCHECK2(*tptr, CDP_HEADER_LEN); - ND_PRINT((ndo, "CDPv%u, ttl: %us", *(tptr + CDP_HEADER_VERSION_OFFSET), - *(tptr + CDP_HEADER_TTL_OFFSET))); +#define T_DEV_ID 0x01 +#define T_MAX 0x17 +static const struct cdp_tlvinfo cdptlvs[T_MAX + 1] = { + /* 0x00 */ + [ T_DEV_ID ] = { "Device-ID", cdp_print_string, -1, -1 }, + [ 0x02 ] = { "Address", cdp_print_addr, -1, -1 }, + [ 0x03 ] = { "Port-ID", cdp_print_string, -1, -1 }, + [ 0x04 ] = { "Capability", cdp_print_capability, 4, 4 }, + [ 0x05 ] = { "Version String", cdp_print_version, -1, -1 }, + [ 0x06 ] = { "Platform", cdp_print_string, -1, -1 }, + [ 0x07 ] = { "Prefixes", cdp_print_prefixes, -1, -1 }, + /* not documented */ + [ 0x08 ] = { "Protocol-Hello option", NULL, -1, -1 }, + /* CDPv2 */ + [ 0x09 ] = { "VTP Management Domain", cdp_print_string, -1, -1 }, + /* CDPv2 */ + [ 0x0a ] = { "Native VLAN ID", cdp_print_uint16, 2, 2 }, + /* CDPv2 */ + [ 0x0b ] = { "Duplex", cdp_print_duplex, 1, 1 }, + /* 0x0c */ + /* 0x0d */ + /* incomplete doc. */ + [ 0x0e ] = { "ATA-186 VoIP VLAN assignment", cdp_print_ata186, 3, 3 }, + /* incomplete doc. */ + [ 0x0f ] = { "ATA-186 VoIP VLAN request", cdp_print_ata186, 2, 3 }, + /* not documented */ + [ 0x10 ] = { "power consumption", cdp_print_power, 1, 3 }, + /* not documented */ + [ 0x11 ] = { "MTU", cdp_print_mtu, 4, 4 }, + /* not documented */ + [ 0x12 ] = { "AVVID trust bitmap", cdp_print_uint8x, 1, 1 }, + /* not documented */ + [ 0x13 ] = { "AVVID untrusted ports CoS", cdp_print_uint8x, 1, 1 }, + /* not documented */ + [ 0x14 ] = { "System Name", cdp_print_string, -1, -1 }, + /* not documented */ + [ 0x15 ] = { "System Object ID (not decoded)", NULL, -1, -1 }, + [ 0x16 ] = { "Management Addresses", cdp_print_addr, 4, -1 }, + /* not documented */ + [ 0x17 ] = { "Physical Location", cdp_print_phys_loc, 1, -1 }, +}; + +void +cdp_print(netdissect_options *ndo, + const u_char *tptr, u_int length) +{ + u_int orig_length = length; + uint16_t checksum; + + ndo->ndo_protocol = "cdp"; + + if (length < CDP_HEADER_LEN) { + ND_PRINT(" (packet length %u < %u)", length, CDP_HEADER_LEN); + goto invalid; + } + ND_PRINT("CDPv%u, ttl: %us", + GET_U_1(tptr + CDP_HEADER_VERSION_OFFSET), + GET_U_1(tptr + CDP_HEADER_TTL_OFFSET)); + checksum = GET_BE_U_2(tptr + CDP_HEADER_CHECKSUM_OFFSET); if (ndo->ndo_vflag) - ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_16BITS(tptr+CDP_HEADER_CHECKSUM_OFFSET), length)); + ND_PRINT(", checksum: 0x%04x (unverified), length %u", + checksum, orig_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 */ + length -= CDP_HEADER_LEN; + + while (length) { + u_int type, len; + const struct cdp_tlvinfo *info; + const char *name; + u_char covered = 0; + + if (length < CDP_TLV_HEADER_LEN) { + ND_PRINT(" (remaining packet length %u < %u)", + length, CDP_TLV_HEADER_LEN); + goto invalid; + } + 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 */ + info = type <= T_MAX ? &cdptlvs[type] : NULL; + name = (info && info->name) ? info->name : "unknown field type"; 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; + if (ndo->ndo_vflag) + ND_PRINT("\n\t%s (0x%02x), TLV length: %u byte%s (too short)", + name, type, len, PLURAL_SUFFIX(len)); + else + ND_PRINT(", %s TLV length %u too short", + name, len); + goto invalid; + } + if (len > length) { + ND_PRINT(" (TLV length %u > %u)", len, length); + goto invalid; } tptr += CDP_TLV_HEADER_LEN; + length -= 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); + /* In non-verbose mode just print Device-ID. */ + if (!ndo->ndo_vflag && type == T_DEV_ID) + ND_PRINT(", Device-ID "); + else if (ndo->ndo_vflag) + ND_PRINT("\n\t%s (0x%02x), value length: %u byte%s: ", + name, type, len, PLURAL_SUFFIX(len)); + + if (info) { + if ((info->min_len > 0 && len < (unsigned)info->min_len) || + (info->max_len > 0 && len > (unsigned)info->max_len)) + ND_PRINT(" (malformed TLV)"); + else if (ndo->ndo_vflag || type == T_DEV_ID) { + if (info->printer) + info->printer(ndo, tptr, len); + else + ND_TCHECK_LEN(tptr, len); + /* + * When the type is defined without a printer, + * do not print the hex dump. + */ + covered = 1; } - break; - default: + } + + if (!covered) { + ND_TCHECK_LEN(tptr, len); print_unknown_data(ndo, tptr, "\n\t ", len); - break; - } } - tptr = tptr+len; + tptr += len; + length -= len; } if (ndo->ndo_vflag < 1) - ND_PRINT((ndo, ", length %u", caplen)); + ND_PRINT(", length %u", orig_length); return; -trunc: - ND_PRINT((ndo, "%s", tstr)); +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(tptr, length); } /* @@ -275,130 +336,137 @@ trunc: #define PT_NLPID 1 /* OSI NLPID */ #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */ -static int +static void cdp_print_addr(netdissect_options *ndo, - const u_char * p, int l) + const u_char * p, u_int l) { - int pt, pl, al, num; - const u_char *endp = p + l; + u_int num; 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); + if (l < 4) { + ND_PRINT(" (not enough space for num)"); + goto invalid; + } + num = GET_BE_U_4(p); p += 4; + l -= 4; + + while (num) { + u_int pt, pl, al; - 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 */ + if (l < 2) { + ND_PRINT(" (not enough space for PT+PL)"); + goto invalid; + } + pt = GET_U_1(p); /* type of "protocol" field */ + pl = GET_U_1(p + 1); /* length of "protocol" field */ p += 2; + l -= 2; - ND_TCHECK2(p[pl], 2); - if (p + pl + 2 > endp) - goto trunc; - al = EXTRACT_16BITS(&p[pl]); /* address length */ + if (l < pl + 2) { + ND_PRINT(" (not enough space for P+AL)"); + goto invalid; + } + /* Skip the protocol for now. */ + al = GET_BE_U_2(p + pl); /* address length */ - if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && 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), * 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; + p += pl + 2; + l -= pl + 2; + /* p is just beyond al now. */ + if (l < al) { + ND_PRINT(" (not enough space for A)"); + goto invalid; + } + ND_PRINT("IPv4 (%u) %s", num, GET_IPADDR_STRING(p)); + p += al; + l -= al; } else if (pt == PT_IEEE_802_2 && pl == 8 && - memcmp(p, prot_ipv6, 8) == 0 && al == 16) { + 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 += pl + 2; + l -= pl + 2; + /* p is just beyond al now. */ + if (l < al) { + ND_PRINT(" (not enough space for A)"); + goto invalid; + } + ND_PRINT("IPv6 (%u) %s", num, GET_IP6ADDR_STRING(p)); p += al; + l -= 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)); + ND_PRINT("pt=0x%02x, pl=%u, pb=", pt, pl); + while (pl != 0) { + ND_PRINT(" %02x", GET_U_1(p)); + p++; + l--; + pl--; + } + ND_PRINT(", al=%u, a=", al); p += 2; - ND_TCHECK2(*p, al); - if (p + al > endp) - goto trunc; - while (al-- > 0) - ND_PRINT((ndo, " %02x", *p++)); + l -= 2; + /* p is just beyond al now. */ + if (l < al) { + ND_PRINT(" (not enough space for A)"); + goto invalid; + } + while (al != 0) { + ND_PRINT(" %02x", GET_U_1(p)); + p++; + l--; + al--; + } } num--; if (num) - ND_PRINT((ndo, " ")); + ND_PRINT(" "); } + if (l) + ND_PRINT(" (%u bytes of stray data)", l); + return; - return 0; - -trunc: - return -1; +invalid: + ND_TCHECK_LEN(p, l); } - -static int +static void cdp_print_prefixes(netdissect_options *ndo, - const u_char * p, int l) + const u_char * p, u_int l) { - if (l % 5) - goto trunc; + if (l % 5) { + ND_PRINT(" [length %u is not a multiple of 5]", l); + goto invalid; + } - ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5)); + ND_PRINT(" IPv4 Prefixes (%u):", l / 5); while (l > 0) { - ND_PRINT((ndo, " %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; } + return; - 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; +invalid: + ND_TCHECK_LEN(p, l); } |