gro: support IPv6 for TCP

Add support for IPv6 GRO for TCP packets.

Signed-off-by: Kumara Parameshwaran <kumaraparamesh92@gmail.com>
Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>

doc/guides/prog_guide/generic_receive_offload_lib.rst

@@ -138,28 +138,29 @@ The key-based algorithm has two characters:
 
    Key-based Reassembly Algorithm
 
-TCP/IPv4 GRO
-------------
+TCP-IPv4/IPv6 GRO
+-----------------
 
-The table structure used by TCP/IPv4 GRO contains two arrays: flow array
+The table structure used by TCP-IPv4/IPv6 GRO contains two arrays: flow array
 and item array. The flow array keeps flow information, and the item array
 keeps packet information.
+The flow array is different for IPv4 and IPv6 while the item array is the same.
 
-Header fields used to define a TCP/IPv4 flow include:
+Header fields used to define a TCP-IPv4/IPv6 flow include:
 
-- source and destination: Ethernet and IP address, TCP port
+- common TCP key fields : Ethernet address, TCP port, TCP acknowledge number
+- version specific IP address
+- IPv6 flow label for IPv6 flow
 
-- TCP acknowledge number
-
-TCP/IPv4 packets whose FIN, SYN, RST, URG, PSH, ECE or CWR bit is set
+TCP packets whose FIN, SYN, RST, URG, PSH, ECE or CWR bit is set
 won't be processed.
 
 Header fields deciding if two packets are neighbors include:
 
 - TCP sequence number
 
 - IPv4 ID. The IPv4 ID fields of the packets, whose DF bit is 0, should
-  be increased by 1.
+  be increased by 1. This is applicable only for IPv4.
 
 VxLAN GRO
 ---------

doc/guides/rel_notes/release_23_07.rst

@@ -196,6 +196,10 @@ New Features
 
   See :doc:`../prog_guide/pdcp_lib` for more information.
 
+* **Added TCP/IPv6 support in GRO library.**
+
+  Enhanced the GRO library to support TCP packets over IPv6 network.
+
 
 Removed Items
 -------------

lib/gro/gro_tcp6.c

@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2023 Intel Corporation
+ */
+
+#include <rte_malloc.h>
+#include <rte_mbuf.h>
+#include <rte_ethdev.h>
+
+#include "gro_tcp6.h"
+#include "gro_tcp_internal.h"
+
+void *
+gro_tcp6_tbl_create(uint16_t socket_id,
+		uint16_t max_flow_num,
+		uint16_t max_item_per_flow)
+{
+	struct gro_tcp6_tbl *tbl;
+	size_t size;
+	uint32_t entries_num, i;
+
+	entries_num = max_flow_num * max_item_per_flow;
+	entries_num = RTE_MIN(entries_num, GRO_TCP6_TBL_MAX_ITEM_NUM);
+
+	if (entries_num == 0)
+		return NULL;
+
+	tbl = rte_zmalloc_socket(__func__,
+			sizeof(struct gro_tcp6_tbl),
+			RTE_CACHE_LINE_SIZE,
+			socket_id);
+	if (tbl == NULL)
+		return NULL;
+
+	size = sizeof(struct gro_tcp_item) * entries_num;
+	tbl->items = rte_zmalloc_socket(__func__,
+			size,
+			RTE_CACHE_LINE_SIZE,
+			socket_id);
+	if (tbl->items == NULL) {
+		rte_free(tbl);
+		return NULL;
+	}
+	tbl->max_item_num = entries_num;
+
+	size = sizeof(struct gro_tcp6_flow) * entries_num;
+	tbl->flows = rte_zmalloc_socket(__func__,
+			size,
+			RTE_CACHE_LINE_SIZE,
+			socket_id);
+	if (tbl->flows == NULL) {
+		rte_free(tbl->items);
+		rte_free(tbl);
+		return NULL;
+	}
+	/* INVALID_ARRAY_INDEX indicates an empty flow */
+	for (i = 0; i < entries_num; i++)
+		tbl->flows[i].start_index = INVALID_ARRAY_INDEX;
+	tbl->max_flow_num = entries_num;
+
+	return tbl;
+}
+
+void
+gro_tcp6_tbl_destroy(void *tbl)
+{
+	struct gro_tcp6_tbl *tcp_tbl = tbl;
+
+	if (tcp_tbl) {
+		rte_free(tcp_tbl->items);
+		rte_free(tcp_tbl->flows);
+	}
+	rte_free(tcp_tbl);
+}
+
+static inline uint32_t
+find_an_empty_flow(struct gro_tcp6_tbl *tbl)
+{
+	uint32_t i;
+	uint32_t max_flow_num = tbl->max_flow_num;
+
+	for (i = 0; i < max_flow_num; i++)
+		if (tbl->flows[i].start_index == INVALID_ARRAY_INDEX)
+			return i;
+	return INVALID_ARRAY_INDEX;
+}
+
+static inline uint32_t
+insert_new_flow(struct gro_tcp6_tbl *tbl,
+		struct tcp6_flow_key *src,
+		uint32_t item_idx)
+{
+	struct tcp6_flow_key *dst;
+	uint32_t flow_idx;
+
+	flow_idx = find_an_empty_flow(tbl);
+	if (unlikely(flow_idx == INVALID_ARRAY_INDEX))
+		return INVALID_ARRAY_INDEX;
+
+	dst = &(tbl->flows[flow_idx].key);
+
+	ASSIGN_COMMON_TCP_KEY((&src->cmn_key), (&dst->cmn_key));
+	memcpy(&dst->src_addr[0], &src->src_addr[0], sizeof(dst->src_addr));
+	memcpy(&dst->dst_addr[0], &src->dst_addr[0], sizeof(dst->dst_addr));
+	dst->vtc_flow = src->vtc_flow;
+
+	tbl->flows[flow_idx].start_index = item_idx;
+	tbl->flow_num++;
+
+	return flow_idx;
+}
+
+/*
+ * update the packet length for the flushed packet.
+ */
+static inline void
+update_header(struct gro_tcp_item *item)
+{
+	struct rte_ipv6_hdr *ipv6_hdr;
+	struct rte_mbuf *pkt = item->firstseg;
+
+	ipv6_hdr = (struct rte_ipv6_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			pkt->l2_len);
+	ipv6_hdr->payload_len = rte_cpu_to_be_16(pkt->pkt_len -
+			pkt->l2_len - pkt->l3_len);
+}
+
+int32_t
+gro_tcp6_reassemble(struct rte_mbuf *pkt,
+		struct gro_tcp6_tbl *tbl,
+		uint64_t start_time)
+{
+	struct rte_ether_hdr *eth_hdr;
+	struct rte_ipv6_hdr *ipv6_hdr;
+	int32_t tcp_dl;
+	uint16_t ip_tlen;
+	struct tcp6_flow_key key;
+	uint32_t i, max_flow_num, remaining_flow_num;
+	uint32_t sent_seq;
+	struct rte_tcp_hdr *tcp_hdr;
+	uint8_t find;
+	uint32_t item_idx;
+	/*
+	 * Don't process the packet whose TCP header length is greater
+	 * than 60 bytes or less than 20 bytes.
+	 */
+	if (unlikely(INVALID_TCP_HDRLEN(pkt->l4_len)))
+		return -1;
+
+	eth_hdr = rte_pktmbuf_mtod(pkt, struct rte_ether_hdr *);
+	ipv6_hdr = (struct rte_ipv6_hdr *)((char *)eth_hdr + pkt->l2_len);
+	tcp_hdr = rte_pktmbuf_mtod_offset(pkt, struct rte_tcp_hdr *, pkt->l2_len + pkt->l3_len);
+
+	/*
+	 * Don't process the packet which has FIN, SYN, RST, PSH, URG, ECE
+	 * or CWR set.
+	 */
+	if (tcp_hdr->tcp_flags != RTE_TCP_ACK_FLAG)
+		return -1;
+
+	ip_tlen = rte_be_to_cpu_16(ipv6_hdr->payload_len);
+	/*
+	 * Don't process the packet whose payload length is less than or
+	 * equal to 0.
+	 */
+	tcp_dl = ip_tlen - pkt->l4_len;
+	if (tcp_dl <= 0)
+		return -1;
+
+	rte_ether_addr_copy(&(eth_hdr->src_addr), &(key.cmn_key.eth_saddr));
+	rte_ether_addr_copy(&(eth_hdr->dst_addr), &(key.cmn_key.eth_daddr));
+	memcpy(&key.src_addr[0], &ipv6_hdr->src_addr, sizeof(key.src_addr));
+	memcpy(&key.dst_addr[0], &ipv6_hdr->dst_addr, sizeof(key.dst_addr));
+	key.cmn_key.src_port = tcp_hdr->src_port;
+	key.cmn_key.dst_port = tcp_hdr->dst_port;
+	key.cmn_key.recv_ack = tcp_hdr->recv_ack;
+	key.vtc_flow = ipv6_hdr->vtc_flow;
+
+	/* Search for a matched flow. */
+	max_flow_num = tbl->max_flow_num;
+	remaining_flow_num = tbl->flow_num;
+	find = 0;
+	for (i = 0; i < max_flow_num && remaining_flow_num; i++) {
+		if (tbl->flows[i].start_index != INVALID_ARRAY_INDEX) {
+			if (is_same_tcp6_flow(&tbl->flows[i].key, &key)) {
+				find = 1;
+				break;
+			}
+			remaining_flow_num--;
+		}
+	}
+
+	if (find == 0) {
+		sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
+		item_idx = insert_new_tcp_item(pkt, tbl->items, &tbl->item_num,
+						tbl->max_item_num, start_time,
+						INVALID_ARRAY_INDEX, sent_seq, 0, true);
+		if (item_idx == INVALID_ARRAY_INDEX)
+			return -1;
+		if (insert_new_flow(tbl, &key, item_idx) ==
+			INVALID_ARRAY_INDEX) {
+			/*
+			 * Fail to insert a new flow, so delete the
+			 * stored packet.
+			 */
+			delete_tcp_item(tbl->items, item_idx, &tbl->item_num, INVALID_ARRAY_INDEX);
+			return -1;
+		}
+		return 0;
+	}
+
+	return process_tcp_item(pkt, tcp_hdr, tcp_dl, tbl->items, tbl->flows[i].start_index,
+						&tbl->item_num, tbl->max_item_num,
+						0, true, start_time);
+}
+
+uint16_t
+gro_tcp6_tbl_timeout_flush(struct gro_tcp6_tbl *tbl,
+		uint64_t flush_timestamp,
+		struct rte_mbuf **out,
+		uint16_t nb_out)
+{
+	uint16_t k = 0;
+	uint32_t i, j;
+	uint32_t max_flow_num = tbl->max_flow_num;
+
+	for (i = 0; i < max_flow_num; i++) {
+		if (unlikely(tbl->flow_num == 0))
+			return k;
+
+		j = tbl->flows[i].start_index;
+		while (j != INVALID_ARRAY_INDEX) {
+			if (tbl->items[j].start_time <= flush_timestamp) {
+				out[k++] = tbl->items[j].firstseg;
+				if (tbl->items[j].nb_merged > 1)
+					update_header(&(tbl->items[j]));
+				/*
+				 * Delete the packet and get the next
+				 * packet in the flow.
+				 */
+				j = delete_tcp_item(tbl->items, j,
+						&tbl->item_num, INVALID_ARRAY_INDEX);
+				tbl->flows[i].start_index = j;
+				if (j == INVALID_ARRAY_INDEX)
+					tbl->flow_num--;
+
+				if (unlikely(k == nb_out))
+					return k;
+			} else
+				/*
+				 * The left packets in this flow won't be
+				 * timeout. Go to check other flows.
+				 */
+				break;
+		}
+	}
+	return k;
+}
+
+uint32_t
+gro_tcp6_tbl_pkt_count(void *tbl)
+{
+	struct gro_tcp6_tbl *gro_tbl = tbl;
+
+	if (gro_tbl)
+		return gro_tbl->item_num;
+
+	return 0;
+}