C++ (Cpp) extract_header_length Examples

Example #1

u_int
ieee802_15_4_if_print(struct netdissect_options *ndo,
                      const struct pcap_pkthdr *h, const u_char *p)
{
	u_int caplen = h->caplen;
	int hdrlen;
	u_int16_t fc;
	u_int8_t seq;

	if (caplen < 3) {
		ND_PRINT((ndo, "[|802.15.4] %x", caplen));
		return caplen;
	}

	fc = EXTRACT_LE_16BITS(p);
	hdrlen = extract_header_length(fc);

	seq = EXTRACT_LE_8BITS(p + 2);

	p += 3;
	caplen -= 3;

	ND_PRINT((ndo,"IEEE 802.15.4 %s packet ", ftypes[fc & 0x7]));
	if (vflag)
		ND_PRINT((ndo,"seq %02x ", seq));
	if (hdrlen == -1) {
		ND_PRINT((ndo,"malformed! "));
		return caplen;
	}


	if (!vflag) {
		p+= hdrlen;
		caplen -= hdrlen;
	} else {
		u_int16_t panid = 0;

		switch ((fc >> 10) & 0x3) {
		case 0x00:
			ND_PRINT((ndo,"none "));
			break;
		case 0x01:
			ND_PRINT((ndo,"reserved destination addressing mode"));
			return 0;
		case 0x02:
			panid = EXTRACT_LE_16BITS(p);
			p += 2;
			ND_PRINT((ndo,"%04x:%04x ", panid, EXTRACT_LE_16BITS(p)));
			p += 2;
			break;
		case 0x03:
			panid = EXTRACT_LE_16BITS(p);
			p += 2;
			ND_PRINT((ndo,"%04x:%s ", panid, le64addr_string(p)));
			p += 8;
			break;
		}
		ND_PRINT((ndo,"< ");

		switch ((fc >> 14) & 0x3) {
		case 0x00:
			ND_PRINT((ndo,"none "));
			break;
		case 0x01:
			ND_PRINT((ndo,"reserved source addressing mode"));
			return 0;
		case 0x02:
			if (!(fc & (1 << 6))) {
				panid = EXTRACT_LE_16BITS(p);
				p += 2;
			}
			ND_PRINT((ndo,"%04x:%04x ", panid, EXTRACT_LE_16BITS(p)));
			p += 2;
			break;
		case 0x03:
			if (!(fc & (1 << 6))) {
				panid = EXTRACT_LE_16BITS(p);
				p += 2;
			}
                        ND_PRINT((ndo,"%04x:%s ", panid, le64addr_string(p))));
			p += 8;
			break;
		}

		caplen -= hdrlen;
	}

	if (!suppress_default_print)
		(ndo->ndo_default_print)(ndo, p, caplen);

	return 0;
}

Example #2

File: print-802_11.c Project: flwh/Alcatel_OT_985_kernel

static u_int
ieee802_11_print(const u_char *p, u_int length, u_int caplen, int pad)
{
	u_int16_t fc;
	u_int hdrlen;
	const u_int8_t *src, *dst;
	u_short extracted_ethertype;

	if (caplen < IEEE802_11_FC_LEN) {
		printf("[|802.11]");
		return caplen;
	}

	fc = EXTRACT_LE_16BITS(p);
	hdrlen = extract_header_length(fc);
	if (pad)
		hdrlen = roundup2(hdrlen, 4);

	if (caplen < hdrlen) {
		printf("[|802.11]");
		return hdrlen;
	}

	ieee_802_11_hdr_print(fc, p, &src, &dst);

	/*
	 * Go past the 802.11 header.
	 */
	length -= hdrlen;
	caplen -= hdrlen;
	p += hdrlen;

	switch (FC_TYPE(fc)) {
	case T_MGMT:
		if (!mgmt_body_print(fc,
		    (const struct mgmt_header_t *)(p - hdrlen), p)) {
			printf("[|802.11]");
			return hdrlen;
		}
		break;
	case T_CTRL:
		if (!ctrl_body_print(fc, p - hdrlen)) {
			printf("[|802.11]");
			return hdrlen;
		}
		break;
	case T_DATA:
		if (DATA_FRAME_IS_NULL(FC_SUBTYPE(fc)))
			return hdrlen;	/* no-data frame */
		/* There may be a problem w/ AP not having this bit set */
		if (FC_WEP(fc)) {
			if (!wep_print(p)) {
				printf("[|802.11]");
				return hdrlen;
			}
		} else if (llc_print(p, length, caplen, dst, src,
		    &extracted_ethertype) == 0) {
			/*
			 * Some kinds of LLC packet we cannot
			 * handle intelligently
			 */
			if (!eflag)
				ieee_802_11_hdr_print(fc, p - hdrlen, NULL,
				    NULL);
			if (extracted_ethertype)
				printf("(LLC %s) ",
				    etherproto_string(
				        htons(extracted_ethertype)));
			if (!suppress_default_print)
				default_print(p, caplen);
		}
		break;
	default:
		printf("unknown 802.11 frame type (%d)", FC_TYPE(fc));
		break;
	}

	return hdrlen;
}