Function process_outer_cksums

dpdk/app/test-pmd/csumonly.c:576–635

Calculate the checksum of outer header */

/* Calculate the checksum of outer header */
static uint64_t
process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
	uint64_t tx_offloads, int tso_enabled, struct rte_mbuf *m)
{
	struct rte_udp_hdr *udp_hdr;
	uint64_t ol_flags = 0;

	if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4)) {
		ol_flags |= RTE_MBUF_F_TX_OUTER_IPV4;

		if (tx_offloads	& RTE_ETH_TX_OFFLOAD_OUTER_IPV4_CKSUM) {
			ol_flags |= RTE_MBUF_F_TX_OUTER_IP_CKSUM;
		} else {
			struct rte_ipv4_hdr *ipv4_hdr = outer_l3_hdr;

			ipv4_hdr->hdr_checksum = 0;
			ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
		}
	} else {
		ol_flags |= RTE_MBUF_F_TX_OUTER_IPV6;
	}

	if (info->outer_l4_proto != IPPROTO_UDP)
		return ol_flags;

	udp_hdr = (struct rte_udp_hdr *)
		((char *)outer_l3_hdr + info->outer_l3_len);

	if (tso_enabled && info->l4_proto == IPPROTO_TCP)
		ol_flags |= RTE_MBUF_F_TX_TCP_SEG;
	else if (tso_enabled && info->l4_proto == IPPROTO_UDP)
		ol_flags |= RTE_MBUF_F_TX_UDP_SEG;

	/* Skip SW outer UDP checksum generation if HW supports it */
	if (tx_offloads & RTE_ETH_TX_OFFLOAD_OUTER_UDP_CKSUM) {
		ol_flags |= RTE_MBUF_F_TX_OUTER_UDP_CKSUM;
		return ol_flags;
	}

	/* outer UDP checksum is done in software. In the other side, for
	 * UDP tunneling, like VXLAN or Geneve, outer UDP checksum can be
	 * set to zero.
	 *
	 * If a packet will be TSOed into small packets by NIC, we cannot
	 * set/calculate a non-zero checksum, because it will be a wrong
	 * value after the packet be split into several small packets.
	 */
	if (tso_enabled)
		udp_hdr->dgram_cksum = 0;

	/* do not recalculate udp cksum if it was 0 */
	if (udp_hdr->dgram_cksum != 0) {
		udp_hdr->dgram_cksum = 0;
		udp_hdr->dgram_cksum = get_udptcp_checksum(m, outer_l3_hdr,
					info->outer_l2_len + info->outer_l3_len,
					info->outer_ethertype);
	}