[PATCH v5 3/6] gso: add VxLAN GSO support

[Mark Kavanagh <mark.b.kavanagh@intel.com>]

This patch adds a framework that allows GSO on tunneled packets.
Furthermore, it leverages that framework to provide GSO support for
VxLAN-encapsulated packets.

Supported VxLAN packets must have an outer IPv4 header (prepended by an
optional VLAN tag), and contain an inner TCP/IPv4 packet (with an optional
inner VLAN tag).

VxLAN GSO doesn't check if input packets have correct checksums and
doesn't update checksums for output packets. Additionally, it doesn't
process IP fragmented packets.

As with TCP/IPv4 GSO, VxLAN GSO uses a two-segment MBUF to organize each
output packet, which mandates support for multi-segment mbufs in the TX
functions of the NIC driver. Also, if a packet is GSOed, VxLAN GSO
reduces its MBUF refcnt by 1. As a result, when all of its GSO'd segments
are freed, the packet is freed automatically.

Signed-off-by: Mark Kavanagh <mark.b.kavanagh@intel.com>
Signed-off-by: Jiayu Hu <jiayu.hu@intel.com>
---
 doc/guides/rel_notes/release_17_11.rst |   3 +
 lib/librte_gso/Makefile                |   1 +
 lib/librte_gso/gso_common.h            |  25 +++++++
 lib/librte_gso/gso_tcp4.c              |   2 +-
 lib/librte_gso/gso_tunnel_tcp4.c       | 123 +++++++++++++++++++++++++++++++++
 lib/librte_gso/gso_tunnel_tcp4.h       |  75 ++++++++++++++++++++
 lib/librte_gso/rte_gso.c               |  13 +++-
 7 files changed, 238 insertions(+), 4 deletions(-)
 create mode 100644 lib/librte_gso/gso_tunnel_tcp4.c
 create mode 100644 lib/librte_gso/gso_tunnel_tcp4.h

diff --git a/doc/guides/rel_notes/release_17_11.rst b/doc/guides/rel_notes/release_17_11.rst
index c414f73..25b8a78 100644
--- a/doc/guides/rel_notes/release_17_11.rst
+++ b/doc/guides/rel_notes/release_17_11.rst
@@ -48,6 +48,9 @@ New Features
   ones (e.g. MTU is 1500B). Supported packet types are:
 
   * TCP/IPv4 packets, which may include a single VLAN tag.
+  * VxLAN packets, which must have an outer IPv4 header (prepended by
+    an optional VLAN tag), and contain an inner TCP/IPv4 packet (with
+    an optional VLAN tag).
 
   The GSO library doesn't check if the input packets have correct
   checksums, and doesn't update checksums for output packets.
diff --git a/lib/librte_gso/Makefile b/lib/librte_gso/Makefile
index 2be64d1..e6d41df 100644
--- a/lib/librte_gso/Makefile
+++ b/lib/librte_gso/Makefile
@@ -44,6 +44,7 @@ LIBABIVER := 1
 SRCS-$(CONFIG_RTE_LIBRTE_GSO) += rte_gso.c
 SRCS-$(CONFIG_RTE_LIBRTE_GSO) += gso_common.c
 SRCS-$(CONFIG_RTE_LIBRTE_GSO) += gso_tcp4.c
+SRCS-$(CONFIG_RTE_LIBRTE_GSO) += gso_tunnel_tcp4.c
 
 # install this header file
 SYMLINK-$(CONFIG_RTE_LIBRTE_GSO)-include += rte_gso.h
diff --git a/lib/librte_gso/gso_common.h b/lib/librte_gso/gso_common.h
index 8d9b94e..c051295 100644
--- a/lib/librte_gso/gso_common.h
+++ b/lib/librte_gso/gso_common.h
@@ -39,6 +39,7 @@
 #include <rte_mbuf.h>
 #include <rte_ip.h>
 #include <rte_tcp.h>
+#include <rte_udp.h>
 
 #define IS_FRAGMENTED(frag_off) (((frag_off) & IPV4_HDR_OFFSET_MASK) != 0 \
 		|| ((frag_off) & IPV4_HDR_MF_FLAG) == IPV4_HDR_MF_FLAG)
@@ -49,6 +50,30 @@
 #define IS_IPV4_TCP(flag) (((flag) & (PKT_TX_TCP_SEG | PKT_TX_IPV4)) == \
 		(PKT_TX_TCP_SEG | PKT_TX_IPV4))
 
+#define IS_IPV4_VXLAN_TCP4(flag) (((flag) & (PKT_TX_TCP_SEG | PKT_TX_IPV4 | \
+				PKT_TX_OUTER_IPV4 | PKT_TX_TUNNEL_VXLAN)) == \
+		(PKT_TX_TCP_SEG | PKT_TX_IPV4 | PKT_TX_OUTER_IPV4 | \
+		 PKT_TX_TUNNEL_VXLAN))
+
+/**
+ * Internal function which updates the UDP header of a packet, following
+ * segmentation. This is required to update the header's datagram length field.
+ *
+ * @param pkt
+ *  The packet containing the UDP header.
+ * @param udp_offset
+ *  The offset of the UDP header from the start of the packet.
+ */
+static inline void
+update_udp_header(struct rte_mbuf *pkt, uint16_t udp_offset)
+{
+	struct udp_hdr *udp_hdr;
+
+	udp_hdr = (struct udp_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			udp_offset);
+	udp_hdr->dgram_len = rte_cpu_to_be_16(pkt->pkt_len - udp_offset);
+}
+
 /**
  * Internal function which updates the TCP header of a packet, following
  * segmentation. This is required to update the header's 'sent' sequence
diff --git a/lib/librte_gso/gso_tcp4.c b/lib/librte_gso/gso_tcp4.c
index 584a77d..fe0b7dd 100644
--- a/lib/librte_gso/gso_tcp4.c
+++ b/lib/librte_gso/gso_tcp4.c
@@ -35,7 +35,7 @@
 #include "gso_tcp4.h"
 
 static void
-update_ipv4_tcp_headers(struct rte_mbuf *pkt, uint64_t l3_offset,
+update_ipv4_tcp_headers(struct rte_mbuf *pkt, uint16_t l3_offset,
 		uint8_t ipid_delta, struct rte_mbuf **segs, uint16_t nb_segs)
 {
 	struct ipv4_hdr *ipv4_hdr;
diff --git a/lib/librte_gso/gso_tunnel_tcp4.c b/lib/librte_gso/gso_tunnel_tcp4.c
new file mode 100644
index 0000000..34bbbd7
--- /dev/null
+++ b/lib/librte_gso/gso_tunnel_tcp4.c
@@ -0,0 +1,123 @@
+/*-
+ *   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 "gso_common.h"
+#include "gso_tunnel_tcp4.h"
+
+static void
+update_tunnel_ipv4_tcp_headers(struct rte_mbuf *pkt, uint8_t ipid_delta,
+		struct rte_mbuf **segs, uint16_t nb_segs)
+{
+	struct ipv4_hdr *ipv4_hdr;
+	struct tcp_hdr *tcp_hdr;
+	uint32_t sent_seq;
+	uint16_t outer_id, inner_id, tail_idx, i;
+	uint16_t outer_ipv4_offset, inner_ipv4_offset, udp_offset, tcp_offset;
+
+	outer_ipv4_offset = pkt->outer_l2_len;
+	udp_offset = outer_ipv4_offset + pkt->outer_l3_len;
+	inner_ipv4_offset = udp_offset + pkt->l2_len;
+	tcp_offset = inner_ipv4_offset + pkt->l3_len;
+
+	/* Outer IPv4 header. */
+	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			outer_ipv4_offset);
+	outer_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
+
+	/* Inner IPv4 header. */
+	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			inner_ipv4_offset);
+	inner_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
+
+	tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
+	sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
+	tail_idx = nb_segs - 1;
+
+	for (i = 0; i < nb_segs; i++) {
+		update_ipv4_header(segs[i], outer_ipv4_offset, outer_id);
+		update_udp_header(segs[i], udp_offset);
+		update_ipv4_header(segs[i], inner_ipv4_offset, inner_id);
+		update_tcp_header(segs[i], tcp_offset, sent_seq, i < tail_idx);
+		outer_id++;
+		inner_id += ipid_delta;
+		sent_seq += (segs[i]->pkt_len - segs[i]->data_len);
+	}
+}
+
+int
+gso_tunnel_tcp4_segment(struct rte_mbuf *pkt,
+		uint16_t gso_size,
+		uint8_t ipid_delta,
+		struct rte_mempool *direct_pool,
+		struct rte_mempool *indirect_pool,
+		struct rte_mbuf **pkts_out,
+		uint16_t nb_pkts_out)
+{
+	struct ipv4_hdr *inner_ipv4_hdr;
+	uint16_t pyld_unit_size, hdr_offset;
+	uint16_t tcp_dl, frag_off;
+	int ret = 1;
+
+	hdr_offset = pkt->outer_l2_len + pkt->outer_l3_len + pkt->l2_len;
+	inner_ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			hdr_offset);
+	/*
+	 * Don't process the packet whose MF bit or offset in the inner
+	 * IPv4 header are non-zero.
+	 */
+	frag_off = rte_be_to_cpu_16(inner_ipv4_hdr->fragment_offset);
+	if (unlikely(IS_FRAGMENTED(frag_off))) {
+		pkts_out[0] = pkt;
+		return 1;
+	}
+
+	/* Don't process the packet without data */
+	tcp_dl = pkt->pkt_len - pkt->l2_len - pkt->l3_len - pkt->l4_len;
+	if (unlikely(tcp_dl == 0)) {
+		pkts_out[0] = pkt;
+		return 1;
+	}
+
+	hdr_offset += pkt->l3_len + pkt->l4_len;
+	pyld_unit_size = gso_size - hdr_offset;
+
+	/* Segment the payload */
+	ret = gso_do_segment(pkt, hdr_offset, pyld_unit_size, direct_pool,
+			indirect_pool, pkts_out, nb_pkts_out);
+	if (ret <= 1)
+		return ret;
+
+	update_tunnel_ipv4_tcp_headers(pkt, ipid_delta, pkts_out, ret);
+
+	return ret;
+}
diff --git a/lib/librte_gso/gso_tunnel_tcp4.h b/lib/librte_gso/gso_tunnel_tcp4.h
new file mode 100644
index 0000000..3c67f0c
--- /dev/null
+++ b/lib/librte_gso/gso_tunnel_tcp4.h
@@ -0,0 +1,75 @@
+/*-
+ *   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.
+ */
+
+#ifndef _GSO_TUNNEL_TCP4_H_
+#define _GSO_TUNNEL_TCP4_H_
+
+#include <stdint.h>
+#include <rte_mbuf.h>
+
+/**
+ * Segment a tunneling packet with inner TCP/IPv4 headers. This function
+ * doesn't check if the input packet has correct checksums, and doesn't
+ * update checksums for output GSO segments. Furthermore, it doesn't
+ * process IP fragment packets.
+ *
+ * @param pkt
+ *  The packet mbuf to segment.
+ * @param gso_size
+ *  The max length of a GSO segment, measured in bytes.
+ * @param ipid_delta
+ *  The increasing unit of IP ids.
+ * @param direct_pool
+ *  MBUF pool used for allocating direct buffers for output segments.
+ * @param indirect_pool
+ *  MBUF pool used for allocating indirect buffers for output segments.
+ * @param pkts_out
+ *  Pointer array used to store the MBUF addresses of output GSO
+ *  segments, when it succeeds. If the memory space in pkts_out is
+ *  insufficient, it fails and returns -EINVAL.
+ * @param nb_pkts_out
+ *  The max number of items that 'pkts_out' can keep.
+ *
+ * @return
+ *   - The number of GSO segments filled in pkts_out on success.
+ *   - Return -ENOMEM if run out of memory in MBUF pools.
+ *   - Return -EINVAL for invalid parameters.
+ */
+int gso_tunnel_tcp4_segment(struct rte_mbuf *pkt,
+		uint16_t gso_size,
+		uint8_t ipid_delta,
+		struct rte_mempool *direct_pool,
+		struct rte_mempool *indirect_pool,
+		struct rte_mbuf **pkts_out,
+		uint16_t nb_pkts_out);
+#endif
diff --git a/lib/librte_gso/rte_gso.c b/lib/librte_gso/rte_gso.c
index a4fce50..6095689 100644
--- a/lib/librte_gso/rte_gso.c
+++ b/lib/librte_gso/rte_gso.c
@@ -39,6 +39,7 @@
 #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,
@@ -58,8 +59,9 @@
 		return -EINVAL;
 
 	if ((gso_ctx->gso_size >= pkt->pkt_len) || (gso_ctx->gso_types &
-				DEV_TX_OFFLOAD_TCP_TSO) !=
-			gso_ctx->gso_types) {
+				(DEV_TX_OFFLOAD_TCP_TSO |
+				 DEV_TX_OFFLOAD_VXLAN_TNL_TSO)) !=
+				gso_ctx->gso_types) {
 		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
 		pkts_out[0] = pkt;
 		return 1;
@@ -71,7 +73,12 @@
 	ipid_delta = (gso_ctx->ipid_flag != RTE_GSO_IPID_FIXED);
 	ol_flags = pkt->ol_flags;
 
-	if (IS_IPV4_TCP(pkt->ol_flags)) {
+	if (IS_IPV4_VXLAN_TCP4(pkt->ol_flags)) {
+		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)) {
 		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
 		ret = gso_tcp4_segment(pkt, gso_size, ipid_delta,
 				direct_pool, indirect_pool,
-- 
1.9.3