X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7de355927bb4dac90db045d52a69bf95c841b807..10ac80fdecfa9b9b7d259d8f50d0b72ef1b18f12:/print-udld.c diff --git a/print-udld.c b/print-udld.c index e8395d0a..37e36d6b 100644 --- a/print-udld.c +++ b/print-udld.c @@ -12,27 +12,26 @@ * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE. * - * UNIDIRECTIONAL LINK DETECTION (UDLD) as per - * http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt - * * Original code by Carles Kishimoto */ +/* \summary: Cisco UniDirectional Link Detection (UDLD) protocol printer */ + +/* specification: RFC 5171 */ + #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include +#include "netdissect-stdinc.h" -#include -#include +#define ND_LONGJMP_FROM_TCHECK +#include "netdissect.h" +#include "extract.h" -#include "interface.h" -#include "addrtoname.h" -#include "extract.h" -#include "nlpid.h" #define UDLD_HEADER_LEN 4 +#define UDLD_TLV_HEADER_LEN 4 #define UDLD_DEVICE_ID_TLV 0x0001 #define UDLD_PORT_ID_TLV 0x0002 #define UDLD_ECHO_TLV 0x0003 @@ -60,114 +59,149 @@ static const struct tok udld_code_values[] = { { 0, NULL} }; -static const struct tok udld_flags_values[] = { - { 0x00, "RT"}, - { 0x01, "RSY"}, +static const struct tok udld_flags_bitmap_str[] = { + { 1U << 0, "RT" }, + { 1U << 1, "RSY" }, + { 1U << 2, "MBZ-2" }, + { 1U << 3, "MBZ-3" }, + { 1U << 4, "MBZ-4" }, + { 1U << 5, "MBZ-5" }, + { 1U << 6, "MBZ-6" }, + { 1U << 7, "MBZ-7" }, { 0, NULL} }; /* + * UDLD's Protocol Data Unit format: + * + * 0 1 2 3 + * 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 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ver | Opcode | Flags | Checksum | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | List of TLVs (variable length list) | + * | ... | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * TLV format: * - * 0 1 2 3 - * 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 - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | Ver | Opcode | Flags | Checksum | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | List of TLVs (variable length list) | - * | ... | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * 0 1 2 3 + * 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 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | TYPE | LENGTH | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | VALUE | + * | ... | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * + * LENGTH: Length in bytes of the Type, Length, and Value fields. */ -#define UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5) -#define UDLD_EXTRACT_OPCODE(x) ((x)&0x1f) +#define UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5) +#define UDLD_EXTRACT_OPCODE(x) ((x)&0x1f) void -udld_print (const u_char *pptr, u_int length) +udld_print(netdissect_options *ndo, + const u_char *tptr, u_int length) { - int code, type, len; - const u_char *tptr; + uint8_t ver, code, flags; + ndo->ndo_protocol = "udld"; if (length < UDLD_HEADER_LEN) - goto trunc; + goto invalid; - tptr = pptr; + ver = UDLD_EXTRACT_VERSION(GET_U_1(tptr)); + code = UDLD_EXTRACT_OPCODE(GET_U_1(tptr)); + tptr += 1; + length -= 1; - if (!TTEST2(*tptr, UDLD_HEADER_LEN)) - goto trunc; + flags = GET_U_1(tptr); + tptr += 1; + length -= 1; - code = UDLD_EXTRACT_OPCODE(*tptr); - - printf("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u", - UDLD_EXTRACT_VERSION(*tptr), + ND_PRINT("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u", + ver, tok2str(udld_code_values, "Reserved", code), code, - bittok2str(udld_flags_values, "none", *(tptr+1)), - *(tptr+1), - length); + bittok2str(udld_flags_bitmap_str, "none", flags), + flags, + length + 2); /* * In non-verbose mode, just print version and opcode type */ - if (vflag < 1) { - return; + if (ndo->ndo_vflag < 1) { + goto tcheck_remainder; } - printf("\n\tChecksum 0x%04x (unverified)", EXTRACT_16BITS(tptr+2)); - - tptr += UDLD_HEADER_LEN; + ND_PRINT("\n\tChecksum 0x%04x (unverified)", GET_BE_U_2(tptr)); + tptr += 2; + length -= 2; - while (tptr < (pptr+length)) { + while (length) { + uint16_t type, len; - if (!TTEST2(*tptr, 4)) - goto trunc; + if (length < UDLD_TLV_HEADER_LEN) + goto invalid; - type = EXTRACT_16BITS(tptr); - len = EXTRACT_16BITS(tptr+2); - len -= 4; - tptr += 4; + type = GET_BE_U_2(tptr); + tptr += 2; + length -= 2; - /* infinite loop check */ - if (type == 0 || len == 0) { - return; - } + len = GET_BE_U_2(tptr); + tptr += 2; + length -= 2; - printf("\n\t%s (0x%04x) TLV, length %u", + ND_PRINT("\n\t%s (0x%04x) TLV, length %u", tok2str(udld_tlv_values, "Unknown", type), type, len); + /* infinite loop check */ + if (len <= UDLD_TLV_HEADER_LEN) + goto invalid; + + len -= UDLD_TLV_HEADER_LEN; + if (length < len) + goto invalid; + switch (type) { case UDLD_DEVICE_ID_TLV: case UDLD_PORT_ID_TLV: + case UDLD_DEVICE_NAME_TLV: + ND_PRINT(", "); + nd_printzp(ndo, tptr, len, NULL); + break; + case UDLD_ECHO_TLV: - case UDLD_DEVICE_NAME_TLV: - printf(", %s", tptr); + ND_PRINT(", "); + (void)nd_printn(ndo, tptr, len, NULL); break; - case UDLD_MESSAGE_INTERVAL_TLV: + case UDLD_MESSAGE_INTERVAL_TLV: case UDLD_TIMEOUT_INTERVAL_TLV: - printf(", %us", (*tptr)); + if (len != 1) + goto invalid; + ND_PRINT(", %us", (GET_U_1(tptr))); break; case UDLD_SEQ_NUMBER_TLV: - printf(", %u", EXTRACT_32BITS(tptr)); + if (len != 4) + goto invalid; + ND_PRINT(", %u", GET_BE_U_4(tptr)); break; default: + ND_TCHECK_LEN(tptr, len); break; - } + } tptr += len; + length -= len; } return; - trunc: - printf("[|udld]"); +invalid: + nd_print_invalid(ndo); +tcheck_remainder: + ND_TCHECK_LEN(tptr, length); } - -/* - * Local Variables: - * c-style: whitesmith - * c-basic-offset: 4 - * End: - */