[PATCH v4 3/5] gso: add VxLAN GSO support

[Jiayu Hu <jiayu.hu@intel.com>]

From: Mark Kavanagh <mark.b.kavanagh@intel.com>

This patch adds 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 all 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 GSOed segments
are freed, the packet is freed automatically.

VxLAN GSO clears the PKT_TX_TCP_SEG flag for the input packet and GSO
segments on the event of success.

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.c            | 58 +++++++++++++++++++++++
 lib/librte_gso/gso_common.h            | 25 ++++++++++
 lib/librte_gso/gso_tunnel_tcp4.c       | 87 ++++++++++++++++++++++++++++++++++
 lib/librte_gso/gso_tunnel_tcp4.h       | 76 +++++++++++++++++++++++++++++
 lib/librte_gso/rte_gso.c               | 13 +++--
 7 files changed, 260 insertions(+), 3 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 7453bb0..2dc6b89 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.c b/lib/librte_gso/gso_common.c
index b2c84f6..90fcb2a 100644
--- a/lib/librte_gso/gso_common.c
+++ b/lib/librte_gso/gso_common.c
@@ -39,6 +39,7 @@
 #include <rte_ether.h>
 #include <rte_ip.h>
 #include <rte_tcp.h>
+#include <rte_udp.h>
 
 #include "gso_common.h"
 
@@ -200,3 +201,60 @@ update_tcp4_header(struct rte_mbuf *pkt, uint8_t ipid_delta,
 		sent_seq += (segs[i]->pkt_len - segs[i]->data_len);
 	}
 }
+
+static inline void
+__update_outer_ipv4_header(struct rte_mbuf *pkt, uint16_t id)
+{
+	struct ipv4_hdr *ipv4_hdr;
+
+	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			pkt->outer_l2_len);
+	ipv4_hdr->total_length = rte_cpu_to_be_16(pkt->pkt_len -
+			pkt->outer_l2_len);
+	ipv4_hdr->packet_id = rte_cpu_to_be_16(id);
+}
+
+static inline void
+__update_outer_udp_header(struct rte_mbuf *pkt)
+{
+	struct udp_hdr *udp_hdr;
+	uint16_t length;
+
+	length = pkt->outer_l2_len + pkt->outer_l3_len;
+	udp_hdr = (struct udp_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			length);
+	udp_hdr->dgram_len = rte_cpu_to_be_16(pkt->pkt_len - length);
+}
+
+void
+update_ipv4_vxlan_tcp4_header(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 l2_len, outer_id, inner_id, tail_idx, i;
+
+	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			pkt->outer_l2_len);
+	outer_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
+
+	l2_len = pkt->outer_l2_len + pkt->outer_l3_len + pkt->l2_len;
+	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
+			l2_len);
+	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_outer_ipv4_header(segs[i], outer_id);
+		outer_id += ipid_delta;
+		__update_outer_udp_header(segs[i]);
+
+		__update_ipv4_tcp_header(segs[i], l2_len, inner_id, sent_seq,
+				i < tail_idx);
+		inner_id += ipid_delta;
+		sent_seq += (segs[i]->pkt_len - segs[i]->data_len);
+	}
+}
diff --git a/lib/librte_gso/gso_common.h b/lib/librte_gso/gso_common.h
index 2a01cd0..0b0d8ed 100644
--- a/lib/librte_gso/gso_common.h
+++ b/lib/librte_gso/gso_common.h
@@ -48,6 +48,11 @@
 #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 relevant packet headers for TCP/IPv4
  * packets, following segmentation. This is required to update, for
@@ -69,6 +74,26 @@ void update_tcp4_header(struct rte_mbuf *pkt,
 		uint16_t nb_segs);
 
 /**
+ * Internal function which updates relevant packet headers for VxLAN
+ * packets, following segmentation. This is required to update, for
+ * example, the IPv4 'total_length' field, to reflect the reduced length
+ * of the now-segmented packet.
+ *
+ * @param pkt
+ *  The original packet.
+ * @param ipid_delta
+ *  The increasing uint of IP ids.
+ * @param segs
+ *  Pointer array used for storing mbuf addresses for GSO segments.
+ * @param nb_segs
+ *  The number of GSO segments placed in segs.
+ */
+void update_ipv4_vxlan_tcp4_header(struct rte_mbuf *pkt,
+		uint8_t ipid_delta,
+		struct rte_mbuf **segs,
+		uint16_t nb_segs);
+
+/**
  * Internal function which divides the input packet into small segments.
  * Each of the newly-created segments is organized as a two-segment MBUF,
  * where the first segment is a standard mbuf, which stores a copy of
diff --git a/lib/librte_gso/gso_tunnel_tcp4.c b/lib/librte_gso/gso_tunnel_tcp4.c
new file mode 100644
index 0000000..cc017bd
--- /dev/null
+++ b/lib/librte_gso/gso_tunnel_tcp4.c
@@ -0,0 +1,87 @@
+/*-
+ *   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 <rte_ether.h>
+#include <rte_ip.h>
+
+#include "gso_common.h"
+#include "gso_tunnel_tcp4.h"
+
+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 and 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 ret;
+	}
+
+	/* 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 ret;
+	}
+
+	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;
+
+	if (pkt->ol_flags & PKT_TX_TUNNEL_VXLAN)
+		update_ipv4_vxlan_tcp4_header(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..a848a2e
--- /dev/null
+++ b/lib/librte_gso/gso_tunnel_tcp4.h
@@ -0,0 +1,76 @@
+/*-
+ *   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 an 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 uint 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 gso_tunnel_tcp4_segment() successes. If the memory
+ *  space in pkts_out is insufficient, gso_tcp4_segment() 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 c65b9ae..d1a723b 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 @@ rte_gso_segment(struct rte_mbuf *pkt,
 		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 ret;
@@ -71,7 +73,12 @@ rte_gso_segment(struct rte_mbuf *pkt,
 	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,
-- 
2.7.4