C++ (Cpp) skb_checksum_try_convert Examples

Example #1

File: gre_demux.c Project: 545191228/linux

/* Fills in tpi and returns header length to be pulled. */
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
		     bool *csum_err, __be16 proto)
{
	const struct gre_base_hdr *greh;
	__be32 *options;
	int hdr_len;

	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
		return -EINVAL;

	greh = (struct gre_base_hdr *)skb_transport_header(skb);
	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
		return -EINVAL;

	tpi->flags = gre_flags_to_tnl_flags(greh->flags);
	hdr_len = gre_calc_hlen(tpi->flags);

	if (!pskb_may_pull(skb, hdr_len))
		return -EINVAL;

	greh = (struct gre_base_hdr *)skb_transport_header(skb);
	tpi->proto = greh->protocol;

	options = (__be32 *)(greh + 1);
	if (greh->flags & GRE_CSUM) {
		if (skb_checksum_simple_validate(skb)) {
			*csum_err = true;
			return -EINVAL;
		}

		skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
					 null_compute_pseudo);
		options++;
	}

	if (greh->flags & GRE_KEY) {
		tpi->key = *options;
		options++;
	} else {
		tpi->key = 0;
	}
	if (unlikely(greh->flags & GRE_SEQ)) {
		tpi->seq = *options;
		options++;
	} else {
		tpi->seq = 0;
	}
	/* WCCP version 1 and 2 protocol decoding.
	 * - Change protocol to IPv4/IPv6
	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
	 */
	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
		tpi->proto = proto;
		if ((*(u8 *)options & 0xF0) != 0x40)
			hdr_len += 4;
	}
	return hdr_len;
}

Example #2

File: gre_demux.c Project: AlexShiLucky/linux

/* Fills in tpi and returns header length to be pulled. */
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
		     bool *csum_err, __be16 proto, int nhs)
{
	const struct gre_base_hdr *greh;
	__be32 *options;
	int hdr_len;

	if (unlikely(!pskb_may_pull(skb, nhs + sizeof(struct gre_base_hdr))))
		return -EINVAL;

	greh = (struct gre_base_hdr *)(skb->data + nhs);
	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
		return -EINVAL;

	tpi->flags = gre_flags_to_tnl_flags(greh->flags);
	hdr_len = gre_calc_hlen(tpi->flags);

	if (!pskb_may_pull(skb, nhs + hdr_len))
		return -EINVAL;

	greh = (struct gre_base_hdr *)(skb->data + nhs);
	tpi->proto = greh->protocol;

	options = (__be32 *)(greh + 1);
	if (greh->flags & GRE_CSUM) {
		if (!skb_checksum_simple_validate(skb)) {
			skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
						 null_compute_pseudo);
		} else if (csum_err) {
			*csum_err = true;
			return -EINVAL;
		}

		options++;
	}

	if (greh->flags & GRE_KEY) {
		tpi->key = *options;
		options++;
	} else {
		tpi->key = 0;
	}
	if (unlikely(greh->flags & GRE_SEQ)) {
		tpi->seq = *options;
		options++;
	} else {
		tpi->seq = 0;
	}
	/* WCCP version 1 and 2 protocol decoding.
	 * - Change protocol to IPv4/IPv6
	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
	 */
	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
		tpi->proto = proto;
		if ((*(u8 *)options & 0xF0) != 0x40)
			hdr_len += 4;
	}
	tpi->hdr_len = hdr_len;

	/* ERSPAN ver 1 and 2 protocol sets GRE key field
	 * to 0 and sets the configured key in the
	 * inner erspan header field
	 */
	if (greh->protocol == htons(ETH_P_ERSPAN) ||
	    greh->protocol == htons(ETH_P_ERSPAN2)) {
		struct erspan_base_hdr *ershdr;

		if (!pskb_may_pull(skb, nhs + hdr_len + sizeof(*ershdr)))
			return -EINVAL;

		ershdr = (struct erspan_base_hdr *)options;
		tpi->key = cpu_to_be32(get_session_id(ershdr));
	}

	return hdr_len;
}