print-pgm.c

TCPDUMP的C语言源代码,是在数据链路层的应用

	     */
	    switch (EXTRACT_16BITS(&nak->pgmn_source_afi)) {
	    case AFI_IP:
		addr_size = sizeof(struct in_addr);
		source_af = AF_INET;
		break;
#ifdef INET6
	    case AFI_IP6:
		addr_size = sizeof(struct in6_addr);
		source_af = AF_INET6;
		break;
#endif
	    default:
		goto trunc;
		break;
	    }
	    bp = (u_char *) (nak + 1);
	    TCHECK2(*bp, addr_size);
	    source = bp;
	    bp += addr_size;

	    /*
	     * Skip past the group, saving info along the way
	     * and stopping if we don't have enough.
	     */
	    switch (EXTRACT_16BITS(bp)) {
	    case AFI_IP:
		addr_size = sizeof(struct in_addr);
		group_af = AF_INET;
		break;
#ifdef INET6
	    case AFI_IP6:
		addr_size = sizeof(struct in6_addr);
		group_af = AF_INET6;
		break;
#endif
	    default:
		goto trunc;
		break;
	    }
	    bp += (2 * sizeof(u_int16_t));
	    TCHECK2(*bp, addr_size);
	    group = bp;
	    bp += addr_size;

	    /*
	     * Options decoding can go here.
	     */
	    inet_ntop(source_af, source, source_buf, sizeof(source_buf));
	    inet_ntop(group_af, group, group_buf, sizeof(group_buf));
	    switch (pgm->pgm_type) {
		case PGM_NAK:
		    (void)printf("NAK ");
		    break;
		case PGM_NULLNAK:
		    (void)printf("NNAK ");
		    break;
		case PGM_NCF:
		    (void)printf("NCF ");
		    break;
		default:
                    break;
	    }
	    (void)printf("(%s -> %s), seq %u",
			 source_buf, group_buf, EXTRACT_32BITS(&nak->pgmn_seq));
	    break;
	}

	case PGM_SPMR:
	    (void)printf("SPMR");
	    break;

	default:
	    (void)printf("UNKNOWN type %0x02x", pgm->pgm_type);
	    break;

	}
	if (pgm->pgm_options & PGM_OPT_BIT_PRESENT) {      

	    /*
	     * make sure there's enough for the first option header
	     */
	    if (!TTEST2(*bp, PGM_MIN_OPT_LEN)) {
		(void)printf("[|OPT]");
		return;
	    } 

	    /*
	     * That option header MUST be an OPT_LENGTH option
	     * (see the first paragraph of section 9.1 in RFC 3208).
	     */
	    opt_type = *bp++;
	    if ((opt_type & PGM_OPT_MASK) != PGM_OPT_LENGTH) {
		(void)printf("[First option bad, should be PGM_OPT_LENGTH, is %u]", opt_type & PGM_OPT_MASK);
		return;
	    }
	    opt_len = *bp++;
	    if (opt_len != 4) {
		(void)printf("[Bad OPT_LENGTH option, length %u != 4]", opt_len);
		return;
	    }
	    opts_len = EXTRACT_16BITS(bp);
	    if (opts_len < 4) {
		(void)printf("[Bad total option length %u < 4]", opts_len);
		return;
	    }
	    bp += sizeof(u_int16_t);
	    (void)printf(" OPTS LEN %d", opts_len);
	    opts_len -= 4;

	    while (opts_len) {
		if (opts_len < PGM_MIN_OPT_LEN) {
		    (void)printf("[Total option length leaves no room for final option]");
		    return;
		}
		opt_type = *bp++;
		opt_len = *bp++;
		if (opt_len < PGM_MIN_OPT_LEN) {
		    (void)printf("[Bad option, length %u < %u]", opt_len,
		        PGM_MIN_OPT_LEN);
		    break;
		}
		if (opts_len < opt_len) {
		    (void)printf("[Total option length leaves no room for final option]");
		    return;
		}
		if (!TTEST2(*bp, opt_len - 2)) {
		    (void)printf(" [|OPT]");
		    return;
		} 

		switch (opt_type & PGM_OPT_MASK) {
		case PGM_OPT_LENGTH:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_LENGTH option, length %u != 4]", opt_len);
			return;
		    }
		    (void)printf(" OPTS LEN (extra?) %d", EXTRACT_16BITS(bp));
		    bp += sizeof(u_int16_t);
		    opts_len -= 4;
		    break;

		case PGM_OPT_FRAGMENT:
		    if (opt_len != 16) {
			(void)printf("[Bad OPT_FRAGMENT option, length %u != 16]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    seq = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    offset = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    len = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" FRAG seq %u off %u len %u", seq, offset, len);
		    opts_len -= 16;
		    break;

		case PGM_OPT_NAK_LIST:
		    flags1 = *bp++;
		    flags2 = *bp++;
		    opt_len -= sizeof(u_int32_t);	/* option header */
		    (void)printf(" NAK LIST");
		    while (opt_len) {
			if (opt_len < sizeof(u_int32_t)) {
			    (void)printf("[Option length not a multiple of 4]");
			    return;
			}
			TCHECK2(*bp, sizeof(u_int32_t));
			(void)printf(" %u", EXTRACT_32BITS(bp));
			bp += sizeof(u_int32_t);
			opt_len -= sizeof(u_int32_t);
			opts_len -= sizeof(u_int32_t);
		    }
		    break;

		case PGM_OPT_JOIN:
		    if (opt_len != 8) {
			(void)printf("[Bad OPT_JOIN option, length %u != 8]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    seq = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" JOIN %u", seq);
		    opts_len -= 8;
		    break;

		case PGM_OPT_NAK_BO_IVL:
		    if (opt_len != 12) {
			(void)printf("[Bad OPT_NAK_BO_IVL option, length %u != 12]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    offset = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    seq = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" BACKOFF ivl %u ivlseq %u", offset, seq);
		    opts_len -= 12;
		    break;

		case PGM_OPT_NAK_BO_RNG:
		    if (opt_len != 12) {
			(void)printf("[Bad OPT_NAK_BO_RNG option, length %u != 12]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    offset = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    seq = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" BACKOFF max %u min %u", offset, seq);
		    opts_len -= 12;
		    break;

		case PGM_OPT_REDIRECT:
		    flags1 = *bp++;
		    flags2 = *bp++;
		    switch (EXTRACT_16BITS(bp)) {
		    case AFI_IP:
			addr_size = sizeof(struct in_addr);
			nla_af = AF_INET;
			break;
#ifdef INET6
		    case AFI_IP6:
			addr_size = sizeof(struct in6_addr);
			nla_af = AF_INET6;
			break;
#endif
		    default:
			goto trunc;
			break;
		    }
		    bp += (2 * sizeof(u_int16_t));
		    if (opt_len != 4 + addr_size) {
			(void)printf("[Bad OPT_REDIRECT option, length %u != 4 + address size]", opt_len);
			return;
		    }
		    TCHECK2(*bp, addr_size);
		    nla = bp;
		    bp += addr_size;

		    inet_ntop(nla_af, nla, nla_buf, sizeof(nla_buf));
		    (void)printf(" REDIRECT %s",  (char *)nla);
		    opts_len -= 4 + addr_size;
		    break;

		case PGM_OPT_PARITY_PRM:
		    if (opt_len != 8) {
			(void)printf("[Bad OPT_PARITY_PRM option, length %u != 8]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    len = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" PARITY MAXTGS %u", len);
		    opts_len -= 8;
		    break;

		case PGM_OPT_PARITY_GRP:
		    if (opt_len != 8) {
			(void)printf("[Bad OPT_PARITY_GRP option, length %u != 8]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    seq = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" PARITY GROUP %u", seq);
		    opts_len -= 8;
		    break;

		case PGM_OPT_CURR_TGSIZE:
		    if (opt_len != 8) {
			(void)printf("[Bad OPT_CURR_TGSIZE option, length %u != 8]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    len = EXTRACT_32BITS(bp);
		    bp += sizeof(u_int32_t);
		    (void)printf(" PARITY ATGS %u", len);
		    opts_len -= 8;
		    break;

		case PGM_OPT_NBR_UNREACH:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_NBR_UNREACH option, length %u != 4]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    (void)printf(" NBR_UNREACH");
		    opts_len -= 4;
		    break;

		case PGM_OPT_PATH_NLA:
		    (void)printf(" PATH_NLA [%d]", opt_len);
		    bp += opt_len;
		    opts_len -= opt_len;
		    break;

		case PGM_OPT_SYN:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_SYN option, length %u != 4]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    (void)printf(" SYN");
		    opts_len -= 4;
		    break;

		case PGM_OPT_FIN:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_FIN option, length %u != 4]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    (void)printf(" FIN");
		    opts_len -= 4;
		    break;

		case PGM_OPT_RST:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_RST option, length %u != 4]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    (void)printf(" RST");
		    opts_len -= 4;
		    break;

		case PGM_OPT_CR:
		    (void)printf(" CR");
		    bp += opt_len;
		    opts_len -= opt_len;
		    break;

		case PGM_OPT_CRQST:
		    if (opt_len != 4) {
			(void)printf("[Bad OPT_CRQST option, length %u != 4]", opt_len);
			return;
		    }
		    flags1 = *bp++;
		    flags2 = *bp++;
		    (void)printf(" CRQST");
		    opts_len -= 4;
		    break;

		default:
		    (void)printf(" OPT_%02X [%d] ", opt_type, opt_len);
		    bp += opt_len;
		    opts_len -= opt_len;
		    break;
		}

		if (opt_type & PGM_OPT_END)
		    break;
	     }
	}

	(void)printf(" [%u]", EXTRACT_16BITS(&pgm->pgm_length));

	return;

trunc:
	fputs("[|pgm]", stdout);
	if (ch != '\0')
		putchar('>');
}