+static uint16_t
+get_psd_sum(void *l3_hdr, uint64_t ol_flags)
+{
+ if (ol_flags & PKT_TX_IPV4)
+ return rte_ipv4_phdr_cksum(l3_hdr, ol_flags);
+ else /* assume ethertype == ETHER_TYPE_IPv6 */
+ return rte_ipv6_phdr_cksum(l3_hdr, ol_flags);
+}
+
+static void virtio_tx_offload(struct rte_mbuf *m)
+{
+ void *l3_hdr;
+ struct ipv4_hdr *ipv4_hdr = NULL;
+ struct tcp_hdr *tcp_hdr = NULL;
+ struct udp_hdr *udp_hdr = NULL;
+ struct sctp_hdr *sctp_hdr = NULL;
+ struct ether_hdr *eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
+
+ l3_hdr = (char *)eth_hdr + m->l2_len;
+
+ if (m->tso_segsz != 0) {
+ ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
+ tcp_hdr = (struct tcp_hdr *)((char *)l3_hdr + m->l3_len);
+ m->ol_flags |= PKT_TX_IP_CKSUM;
+ ipv4_hdr->hdr_checksum = 0;
+ tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
+ return;
+ }
+
+ if (m->ol_flags & PKT_TX_L4_MASK) {
+ switch (m->ol_flags & PKT_TX_L4_MASK) {
+ case PKT_TX_TCP_CKSUM:
+ tcp_hdr = (struct tcp_hdr *)
+ ((char *)l3_hdr + m->l3_len);
+ tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
+ break;
+ case PKT_TX_UDP_CKSUM:
+ udp_hdr = (struct udp_hdr *)
+ ((char *)l3_hdr + m->l3_len);
+ udp_hdr->dgram_cksum = get_psd_sum(l3_hdr, m->ol_flags);
+ break;
+ case PKT_TX_SCTP_CKSUM:
+ sctp_hdr = (struct sctp_hdr *)
+ ((char *)l3_hdr + m->l3_len);
+ sctp_hdr->cksum = 0;
+ break;
+ default:
+ break;
+ }
+ }
+}
+