Function pmd_tx_burst

dpdk/drivers/net/tap/rte_eth_tap.c:658–757

Callback to handle sending packets from the tap interface */

/* Callback to handle sending packets from the tap interface
 */
static uint16_t
pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
{
	struct tx_queue *txq = queue;
	uint16_t num_tx = 0;
	uint16_t num_packets = 0;
	unsigned long num_tx_bytes = 0;
	uint32_t max_size;
	int i;

	if (unlikely(nb_pkts == 0))
		return 0;

	struct rte_mbuf *gso_mbufs[MAX_GSO_MBUFS];
	max_size = *txq->mtu + (RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN + 4);
	for (i = 0; i < nb_pkts; i++) {
		struct rte_mbuf *mbuf_in = bufs[num_tx];
		struct rte_mbuf **mbuf;
		uint16_t num_mbufs = 0;
		uint16_t tso_segsz = 0;
		int ret;
		int num_tso_mbufs;
		uint16_t hdrs_len;
		uint64_t tso;

		tso = mbuf_in->ol_flags & RTE_MBUF_F_TX_TCP_SEG;
		if (tso) {
			struct rte_gso_ctx *gso_ctx = &txq->gso_ctx;

			/* TCP segmentation implies TCP checksum offload */
			mbuf_in->ol_flags |= RTE_MBUF_F_TX_TCP_CKSUM;

			/* gso size is calculated without RTE_ETHER_CRC_LEN */
			hdrs_len = mbuf_in->l2_len + mbuf_in->l3_len +
					mbuf_in->l4_len;
			tso_segsz = mbuf_in->tso_segsz + hdrs_len;
			if (unlikely(tso_segsz == hdrs_len) ||
				tso_segsz > *txq->mtu) {
				txq->stats.errs++;
				break;
			}
			gso_ctx->gso_size = tso_segsz;
			/* 'mbuf_in' packet to segment */
			num_tso_mbufs = rte_gso_segment(mbuf_in,
				gso_ctx, /* gso control block */
				(struct rte_mbuf **)&gso_mbufs, /* out mbufs */
				RTE_DIM(gso_mbufs)); /* max tso mbufs */

			/* ret contains the number of new created mbufs */
			if (num_tso_mbufs < 0)
				break;

			if (num_tso_mbufs >= 1) {
				mbuf = gso_mbufs;
				num_mbufs = num_tso_mbufs;
			} else {
				/* 0 means it can be transmitted directly
				 * without gso.