/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2017 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>

#include <rte_log.h>
#include <rte_ethdev.h>

#include "rte_gso.h"
#include "gso_common.h"
#include "gso_tcp4.h"
#include "gso_tunnel_tcp4.h"

int
rte_gso_segment(struct rte_mbuf *pkt,
		const struct rte_gso_ctx *gso_ctx,
		struct rte_mbuf **pkts_out,
		uint16_t nb_pkts_out)
{
	struct rte_mempool *direct_pool, *indirect_pool;
	struct rte_mbuf *pkt_seg;
	uint64_t ol_flags;
	uint16_t gso_size;
	uint8_t ipid_delta;
	int ret = 1;

	if (pkt == NULL || pkts_out == NULL || gso_ctx == NULL ||
			nb_pkts_out < 1 ||
			gso_ctx->gso_size < RTE_GSO_SEG_SIZE_MIN ||
			((gso_ctx->gso_types & (DEV_TX_OFFLOAD_TCP_TSO |
			DEV_TX_OFFLOAD_VXLAN_TNL_TSO |
			DEV_TX_OFFLOAD_GRE_TNL_TSO)) == 0))
		return -EINVAL;

	if (gso_ctx->gso_size >= pkt->pkt_len) {
		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
		pkts_out[0] = pkt;
		return 1;
	}

	direct_pool = gso_ctx->direct_pool;
	indirect_pool = gso_ctx->indirect_pool;
	gso_size = gso_ctx->gso_size;
	ipid_delta = (gso_ctx->flag != RTE_GSO_FLAG_IPID_FIXED);
	ol_flags = pkt->ol_flags;

	if ((IS_IPV4_VXLAN_TCP4(pkt->ol_flags) &&
			(gso_ctx->gso_types & DEV_TX_OFFLOAD_VXLAN_TNL_TSO)) ||
			((IS_IPV4_GRE_TCP4(pkt->ol_flags) &&
			 (gso_ctx->gso_types & DEV_TX_OFFLOAD_GRE_TNL_TSO)))) {
		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
		ret = gso_tunnel_tcp4_segment(pkt, gso_size, ipid_delta,
				direct_pool, indirect_pool,
				pkts_out, nb_pkts_out);
	} else if (IS_IPV4_TCP(pkt->ol_flags) &&
			(gso_ctx->gso_types & DEV_TX_OFFLOAD_TCP_TSO)) {
		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
		ret = gso_tcp4_segment(pkt, gso_size, ipid_delta,
				direct_pool, indirect_pool,
				pkts_out, nb_pkts_out);
	} else {
		/* unsupported packet, skip */
		pkts_out[0] = pkt;
		RTE_LOG(DEBUG, GSO, "Unsupported packet type\n");
		return 1;
	}

	if (ret > 1) {
		pkt_seg = pkt;
		while (pkt_seg) {
			rte_mbuf_refcnt_update(pkt_seg, -1);
			pkt_seg = pkt_seg->next;
		}
	} else if (ret < 0) {
		/* Revert the ol_flags in the event of failure. */
		pkt->ol_flags = ol_flags;
	}

	return ret;
}