[dpdk-dev] [PATCH 2/5] gso/lib: add TCP/IPv4 GSO support
Kavanagh, Mark B
mark.b.kavanagh at intel.com
Wed Aug 30 11:25:38 CEST 2017
>From: Hu, Jiayu
>Sent: Wednesday, August 30, 2017 3:56 AM
>To: Ananyev, Konstantin <konstantin.ananyev at intel.com>
>Cc: dev at dpdk.org; Kavanagh, Mark B <mark.b.kavanagh at intel.com>; Tan, Jianfeng
><jianfeng.tan at intel.com>
>Subject: Re: [PATCH 2/5] gso/lib: add TCP/IPv4 GSO support
>
>Hi Konstantin,
>
>Thanks for your important suggestions. My feedbacks are inline.
>
>On Wed, Aug 30, 2017 at 09:38:33AM +0800, Ananyev, Konstantin wrote:
>>
>>
>> > -----Original Message-----
>> > From: Hu, Jiayu
>> > Sent: Thursday, August 24, 2017 3:16 PM
>> > To: dev at dpdk.org
>> > Cc: Kavanagh, Mark B <mark.b.kavanagh at intel.com>; Ananyev, Konstantin
><konstantin.ananyev at intel.com>; Tan, Jianfeng
>> > <jianfeng.tan at intel.com>; Hu, Jiayu <jiayu.hu at intel.com>
>> > Subject: [PATCH 2/5] gso/lib: add TCP/IPv4 GSO support
>> >
>> > This patch adds GSO support for TCP/IPv4 packets. Supported packets
>> > may include a single VLAN tag. TCP/IPv4 GSO assumes that all input
>> > packets have correct checksums, and doesn't update checksums for output
>> > packets (the responsibility for this lies with the application).
>> > Additionally, TCP/IPv4 GSO doesn't process IP fragmented packets.
>> >
>> > TCP/IPv4 GSO uses two chained MBUFs, one direct MBUF and one indrect
>> > MBUF, to organize an output packet. Note that we refer to these two
>> > chained MBUFs as a two-segment MBUF. The direct MBUF stores the packet
>> > header, while the indirect mbuf simply points to a location within the
>> > original packet's payload. Consequently, use of the GSO library requires
>> > multi-segment MBUF support in the TX functions of the NIC driver.
>> >
>> > If a packet is GSOed, TCP/IPv4 GSO reduces its MBUF refcnt by 1. As a
>> > result, when all of its GSOed segments are freed, the packet is freed
>> > automatically.
>> >
>> > Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
>> > Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
>> > ---
>> > lib/librte_eal/common/include/rte_log.h | 1 +
>> > lib/librte_gso/Makefile | 2 +
>> > lib/librte_gso/gso_common.c | 270
>++++++++++++++++++++++++++++++++
>> > lib/librte_gso/gso_common.h | 120 ++++++++++++++
>> > lib/librte_gso/gso_tcp.c | 82 ++++++++++
>> > lib/librte_gso/gso_tcp.h | 73 +++++++++
>> > lib/librte_gso/rte_gso.c | 44 +++++-
>> > lib/librte_gso/rte_gso.h | 3 +
>> > 8 files changed, 593 insertions(+), 2 deletions(-)
>> > create mode 100644 lib/librte_gso/gso_common.c
>> > create mode 100644 lib/librte_gso/gso_common.h
>> > create mode 100644 lib/librte_gso/gso_tcp.c
>> > create mode 100644 lib/librte_gso/gso_tcp.h
>> >
>> > diff --git a/lib/librte_eal/common/include/rte_log.h
>b/lib/librte_eal/common/include/rte_log.h
>> > index ec8dba7..2fa1199 100644
>> > --- a/lib/librte_eal/common/include/rte_log.h
>> > +++ b/lib/librte_eal/common/include/rte_log.h
>> > @@ -87,6 +87,7 @@ extern struct rte_logs rte_logs;
>> > #define RTE_LOGTYPE_CRYPTODEV 17 /**< Log related to cryptodev. */
>> > #define RTE_LOGTYPE_EFD 18 /**< Log related to EFD. */
>> > #define RTE_LOGTYPE_EVENTDEV 19 /**< Log related to eventdev. */
>> > +#define RTE_LOGTYPE_GSO 20 /**< Log related to GSO. */
>> >
>> > /* these log types can be used in an application */
>> > #define RTE_LOGTYPE_USER1 24 /**< User-defined log type 1. */
>> > diff --git a/lib/librte_gso/Makefile b/lib/librte_gso/Makefile
>> > index aeaacbc..0f8e38f 100644
>> > --- a/lib/librte_gso/Makefile
>> > +++ b/lib/librte_gso/Makefile
>> > @@ -42,6 +42,8 @@ LIBABIVER := 1
>> >
>> > #source files
>> > SRCS-$(CONFIG_RTE_LIBRTE_GSO) += rte_gso.c
>> > +SRCS-$(CONFIG_RTE_LIBRTE_GSO) += gso_common.c
>> > +SRCS-$(CONFIG_RTE_LIBRTE_GSO) += gso_tcp.c
>> >
>> > # install this header file
>> > SYMLINK-$(CONFIG_RTE_LIBRTE_GSO)-include += rte_gso.h
>> > diff --git a/lib/librte_gso/gso_common.c b/lib/librte_gso/gso_common.c
>> > new file mode 100644
>> > index 0000000..2b54fbd
>> > --- /dev/null
>> > +++ b/lib/librte_gso/gso_common.c
>> > @@ -0,0 +1,270 @@
>> > +/*-
>> > + * 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 <stdbool.h>
>> > +#include <string.h>
>> > +
>> > +#include <rte_malloc.h>
>> > +
>> > +#include <rte_ether.h>
>> > +#include <rte_ip.h>
>> > +#include <rte_tcp.h>
>> > +
>> > +#include "gso_common.h"
>> > +
>> > +static inline void
>> > +hdr_segment_init(struct rte_mbuf *hdr_segment, struct rte_mbuf *pkt,
>> > + uint16_t pkt_hdr_offset)
>> > +{
>> > + /* copy mbuf metadata */
>> > + hdr_segment->nb_segs = 1;
>> > + hdr_segment->port = pkt->port;
>> > + hdr_segment->ol_flags = pkt->ol_flags;
>> > + hdr_segment->packet_type = pkt->packet_type;
>> > + hdr_segment->pkt_len = pkt_hdr_offset;
>> > + hdr_segment->data_len = pkt_hdr_offset;
>> > + hdr_segment->tx_offload = pkt->tx_offload;
>> > + /* copy packet header */
>> > + rte_memcpy(rte_pktmbuf_mtod(hdr_segment, char *),
>> > + rte_pktmbuf_mtod(pkt, char *),
>> > + pkt_hdr_offset);
>> > +}
>> > +
>> > +static inline void
>> > +free_gso_segment(struct rte_mbuf **pkts, uint16_t nb_pkts)
>> > +{
>> > + uint16_t i;
>> > +
>> > + for (i = 0; i < nb_pkts; i++) {
>> > + rte_pktmbuf_detach(pkts[i]->next);
>>
>> I don't think you need to call detach() here explicitly.
>> Just rte_pktmbuf_free(pkts[i]) should do I think.
>
>Yes, rte_pktmbuf_free() is enough. I will modify it. Thanks.
>
>>
>> > + rte_pktmbuf_free(pkts[i]);
>> > + pkts[i] = NULL;
>> > + }
>> > +}
>> > +
>> > +int
>> > +gso_do_segment(struct rte_mbuf *pkt,
>> > + uint16_t pkt_hdr_offset,
>> > + uint16_t pyld_unit_size,
>> > + struct rte_mempool *direct_pool,
>> > + struct rte_mempool *indirect_pool,
>> > + struct rte_mbuf **pkts_out,
>> > + uint16_t nb_pkts_out)
>> > +{
>> > + struct rte_mbuf *pkt_in;
>> > + struct rte_mbuf *hdr_segment, *pyld_segment;
>> > + uint32_t pkt_in_pyld_off;
>> > + uint16_t pkt_in_segment_len, pkt_out_segment_len;
>> > + uint16_t nb_segs;
>> > + bool pkt_in_segment_processed;
>> > +
>> > + pkt_in_pyld_off = pkt->data_off + pkt_hdr_offset;
>> > + pkt_in = pkt;
>> > + nb_segs = 0;
>> > +
>> > + while (pkt_in) {
>> > + pkt_in_segment_processed = false;
>> > + pkt_in_segment_len = pkt_in->data_off + pkt_in->data_len;
>> > +
>> > + while (!pkt_in_segment_processed) {
>> > + if (unlikely(nb_segs >= nb_pkts_out)) {
>> > + free_gso_segment(pkts_out, nb_segs);
>> > + return -EINVAL;
>> > + }
>> > +
>> > + /* allocate direct mbuf */
>> > + hdr_segment = rte_pktmbuf_alloc(direct_pool);
>> > + if (unlikely(hdr_segment == NULL)) {
>> > + free_gso_segment(pkts_out, nb_segs);
>> > + return -ENOMEM;
>> > + }
>> > +
>> > + /* allocate indirect mbuf */
>> > + pyld_segment = rte_pktmbuf_alloc(indirect_pool);
>> > + if (unlikely(pyld_segment == NULL)) {
>> > + rte_pktmbuf_free(hdr_segment);
>> > + free_gso_segment(pkts_out, nb_segs);
>> > + return -ENOMEM;
>> > + }
>>
>> So, if I understand correctly each new packet would always contain just one
>data segment?
>> Why several data segments couldn't be chained together (if sum of their
>data_len <= mss)?
>> In a same way as done here:
>>
>http://dpdk.org/browse/dpdk/tree/lib/librte_ip_frag/rte_ipv4_fragmentation.c#n
>93
>> or here:
>>
>https://gerrit.fd.io/r/gitweb?p=tldk.git;a=blob;f=lib/libtle_l4p/tcp_tx_seg.h;
>h=a8d2425597a7ad6f598aa4bb7fcd7f1da74305f0;hb=HEAD#l23
>> ?
>
>Oh, yes. I can chain these data segments when their total length is less than
>the GSO segsz.
>I will change it in the next patch. Thanks very much.
>
>>
>> > +
>> > + /* copy packet header */
>> > + hdr_segment_init(hdr_segment, pkt, pkt_hdr_offset);
>> > +
>> > + /* attach payload mbuf to current packet segment */
>> > + rte_pktmbuf_attach(pyld_segment, pkt_in);
>> > +
>> > + hdr_segment->next = pyld_segment;
>> > + pkts_out[nb_segs++] = hdr_segment;
>> > +
>> > + /* calculate payload length */
>> > + pkt_out_segment_len = pyld_unit_size;
>> > + if (pkt_in_pyld_off + pkt_out_segment_len >
>> > + pkt_in_segment_len) {
>> > + pkt_out_segment_len = pkt_in_segment_len -
>> > + pkt_in_pyld_off;
>> > + }
>> > +
>> > + /* update payload segment */
>> > + pyld_segment->data_off = pkt_in_pyld_off;
>> > + pyld_segment->data_len = pkt_out_segment_len;
>> > +
>> > + /* update header segment */
>> > + hdr_segment->pkt_len += pyld_segment->data_len;
>> > + hdr_segment->nb_segs++;
>> > +
>> > + /* update pkt_in_pyld_off */
>> > + pkt_in_pyld_off += pkt_out_segment_len;
>> > + if (pkt_in_pyld_off == pkt_in_segment_len)
>> > + pkt_in_segment_processed = true;
>> > + }
>> > +
>> > + /* 'pkt_in' may contain numerous segments */
>> > + pkt_in = pkt_in->next;
>> > + if (pkt_in != NULL)
>> > + pkt_in_pyld_off = pkt_in->data_off;
>> > + }
>> > + return nb_segs;
>> > +}
>> > +
>> > +static inline void
>> > +parse_ipv4(struct ipv4_hdr *ipv4_hdr, struct rte_mbuf *pkt)
>> > +{
>> > + struct tcp_hdr *tcp_hdr;
>> > +
>> > + switch (ipv4_hdr->next_proto_id) {
>> > + case IPPROTO_TCP:
>> > + pkt->packet_type |= RTE_PTYPE_L4_TCP;
>> > + pkt->l3_len = IPv4_HDR_LEN(ipv4_hdr);
>> > + tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
>> > + pkt->l4_len = TCP_HDR_LEN(tcp_hdr);
>> > + break;
>> > + }
>> > +}
>> > +
>> > +static inline void
>> > +parse_ethernet(struct ether_hdr *eth_hdr, struct rte_mbuf *pkt)
>> > +{
>> > + struct ipv4_hdr *ipv4_hdr;
>> > + struct vlan_hdr *vlan_hdr;
>> > + uint16_t ethertype;
>> > +
>> > + ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
>> > + if (ethertype == ETHER_TYPE_VLAN) {
>> > + vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
>> > + pkt->l2_len = sizeof(struct vlan_hdr);
>> > + pkt->packet_type |= RTE_PTYPE_L2_ETHER_VLAN;
>> > + ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
>> > + }
>> > +
>> > + switch (ethertype) {
>> > + case ETHER_TYPE_IPv4:
>> > + if (IS_VLAN_PKT(pkt)) {
>> > + pkt->packet_type |= RTE_PTYPE_L3_IPV4;
>> > + } else {
>> > + pkt->packet_type |= RTE_PTYPE_L2_ETHER;
>> > + pkt->packet_type |= RTE_PTYPE_L3_IPV4;
>> > + }
>> > + pkt->l2_len += sizeof(struct ether_hdr);
>> > + ipv4_hdr = (struct ipv4_hdr *) ((char *)eth_hdr +
>> > + pkt->l2_len);
>> > + parse_ipv4(ipv4_hdr, pkt);
>> > + break;
>> > + }
>> > +}
>> > +
>> > +void
>> > +gso_parse_packet(struct rte_mbuf *pkt)
>>
>> There is a function rte_net_get_ptype() that supposed to provide similar
>functionality.
>> So we probably don't need to create a new SW parse function here, instead
>would be better
>> to reuse (and update if needed) an existing one.
>> Again user already might have l2/l3/l4.../_len and packet_type setuped.
>> So better to keep SW packet parsing out of scope of that library.
>
>Hmm, I know we have discussed this design choice in the GRO library, and I
>also think it's
>better to reuse these values.
>
>But from the perspective of OVS, it may add extra overhead, since OVS doesn't
>parse every
>packet originally. Maybe @Mark can give us more inputs from the view of OVS.
Hi Jiayu, Konstantin
For GSO, the application needs to know:
- the packet type (as it only currently supports TCP/IPv4, VxLAN, GRE packets)
- the l2/3/4_lens, etc. (in order to replicate the original packet's headers across outgoing segments)
For this, we can use the rte_net_get_ptype function, as per Konstantin's suggestion, as it provides both - thanks Konstantin!
WRT the extra overhead in OvS: TSO is the defacto standard, and GSO is provided purely as a fallback option. As such, and since the additional packet parsing is a necessity in order to facilitate GSO, the additional overhead is IMO acceptable.
Thanks,
Mark
>
>>
>> > +{
>> > + struct ether_hdr *eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
>> > +
>> > + pkt->packet_type = pkt->tx_offload = 0;
>> > + parse_ethernet(eth_hdr, pkt);
>> > +}
>> > +
>> > +static inline void
>> > +update_ipv4_header(char *base, uint16_t offset, uint16_t length, uint16_t
>id)
>> > +{
>> > + struct ipv4_hdr *ipv4_hdr = (struct ipv4_hdr *)(base + offset);
>> > +
>> > + ipv4_hdr->total_length = rte_cpu_to_be_16(length - offset);
>> > + ipv4_hdr->packet_id = rte_cpu_to_be_16(id);
>> > +}
>> > +
>> > +static inline void
>> > +update_tcp_header(char *base, uint16_t offset, uint32_t sent_seq,
>> > + uint8_t non_tail)
>> > +{
>> > + struct tcp_hdr *tcp_hdr = (struct tcp_hdr *)(base + offset);
>> > +
>> > + tcp_hdr->sent_seq = rte_cpu_to_be_32(sent_seq);
>> > + /* clean FIN and PSH for non-tail segments */
>> > + if (non_tail)
>> > + tcp_hdr->tcp_flags &= (~(TCP_HDR_PSH_MASK | TCP_HDR_FIN_MASK));
>> > +}
>> > +
>> > +void
>> > +gso_update_pkt_headers(struct rte_mbuf *pkt, uint16_t nb_segments,
>> > + struct rte_mbuf **out_segments)
>> > +{
>> > + struct ipv4_hdr *ipv4_hdr;
>> > + struct tcp_hdr *tcp_hdr;
>> > + struct rte_mbuf *seg;
>> > + uint32_t sent_seq;
>> > + uint16_t offset, i;
>> > + uint16_t tail_seg_idx = nb_segments - 1, id;
>> > +
>> > + switch (pkt->packet_type) {
>> > + case ETHER_VLAN_IPv4_TCP_PKT:
>> > + case ETHER_IPv4_TCP_PKT:
>>
>> Might be worth to put code below in a separate function:
>> update_inner_tcp_hdr(..) or so.
>> Then you can reuse it for tunneled cases too.
>
>Yes, I will modify it in the next patch. Thanks.
>
>>
>> > + ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *)
>> > + pkt->l2_len);
>> > + tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
>> > + id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
>> > + sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
>> > +
>> > + for (i = 0; i < nb_segments; i++) {
>> > + seg = out_segments[i];
>> > +
>> > + offset = seg->l2_len;
>> > + update_ipv4_header(rte_pktmbuf_mtod(seg, char *),
>> > + offset, seg->pkt_len, id);
>> > + id++;
>>
>> Who would be responsible to make sure that we wouldn't have consecutive
>packets with the IPV4 id?
>> Would be the upper layer that forms the packet or gso library or ...?
>
>Oh yes. I ingore this important issue. I don't think applications can
>guarantee it.
>I will check the design of linux and try to figure out a way. Thanks for
>reminder.
>
>>
>> > +
>> > + offset += seg->l3_len;
>> > + update_tcp_header(rte_pktmbuf_mtod(seg, char *),
>> > + offset, sent_seq, i < tail_seg_idx);
>> > + sent_seq += seg->next->data_len;
>> > + }
>> > + break;
>> > + }
>> > +}
>> > diff --git a/lib/librte_gso/gso_common.h b/lib/librte_gso/gso_common.h
>> > new file mode 100644
>> > index 0000000..d750041
>> > --- /dev/null
>> > +++ b/lib/librte_gso/gso_common.h
>> > @@ -0,0 +1,120 @@
>> > +/*-
>> > + * 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_COMMON_H_
>> > +#define _GSO_COMMON_H_
>> > +
>> > +#include <stdint.h>
>> > +#include <rte_mbuf.h>
>> > +
>> > +#define IPV4_HDR_DF_SHIFT 14
>> > +#define IPV4_HDR_DF_MASK (1 << IPV4_HDR_DF_SHIFT)
>> > +#define IPv4_HDR_LEN(iph) ((iph->version_ihl & 0x0f) * 4)
>> > +
>> > +#define TCP_HDR_PSH_MASK ((uint8_t)0x08)
>> > +#define TCP_HDR_FIN_MASK ((uint8_t)0x01)
>> > +#define TCP_HDR_LEN(tcph) ((tcph->data_off & 0xf0) >> 2)
>> > +
>> > +#define ETHER_IPv4_PKT (RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4)
>> > +/* Supported packet types */
>> > +/* TCP/IPv4 packet. */
>> > +#define ETHER_IPv4_TCP_PKT (ETHER_IPv4_PKT | RTE_PTYPE_L4_TCP)
>> > +
>> > +/* TCP/IPv4 packet with VLAN tag. */
>> > +#define ETHER_VLAN_IPv4_TCP_PKT (RTE_PTYPE_L2_ETHER_VLAN | \
>> > + RTE_PTYPE_L3_IPV4 | RTE_PTYPE_L4_TCP)
>> > +
>> > +#define IS_VLAN_PKT(pkt) ((pkt->packet_type & RTE_PTYPE_L2_ETHER_VLAN) ==
>\
>> > + RTE_PTYPE_L2_ETHER_VLAN)
>> > +
>> > +/**
>> > + * Internal function which parses a packet, setting outer_l2/l3_len and
>> > + * l2/l3/l4_len and packet_type.
>> > + *
>> > + * @param pkt
>> > + * Packet to parse.
>> > + */
>> > +void gso_parse_packet(struct rte_mbuf *pkt);
>> > +
>> > +/**
>> > + * Internal function which updates relevant packet headers, 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 nb_segments
>> > + * The number of GSO segments into which pkt was split.
>> > + * @param out_segements
>> > + * Pointer array used for storing mbuf addresses for GSO segments.
>> > + */
>> > +void gso_update_pkt_headers(struct rte_mbuf *pkt, uint16_t nb_segments,
>> > + struct rte_mbuf **out_segments);
>> > +
>> > +/**
>> > + * 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
>> > + * packet header, and the second is an indirect mbuf which points to a
>> > + * section of data in the input packet.
>> > + *
>> > + * @param pkt
>> > + * Packet to segment.
>> > + * @param pkt_hdr_offset
>> > + * Packet header offset, measured in byte.
>> > + * @param pyld_unit_size
>> > + * The max payload length of a GSO segment.
>> > + * @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 keep the mbuf addresses of output segments.
>> > + * @param nb_pkts_out
>> > + * The max number of items that pkts_out can keep.
>> > + *
>> > + * @return
>> > + * - The number of segments created in the event of success.
>> > + * - If no GSO is performed, return 1.
>> > + * - If available memory in mempools is insufficient, return -ENOMEM.
>> > + * - -EINVAL for invalid parameters
>> > + */
>> > +int gso_do_segment(struct rte_mbuf *pkt,
>> > + uint16_t pkt_hdr_offset,
>> > + uint16_t pyld_unit_size,
>> > + 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/gso_tcp.c b/lib/librte_gso/gso_tcp.c
>> > new file mode 100644
>> > index 0000000..9d5fc30
>> > --- /dev/null
>> > +++ b/lib/librte_gso/gso_tcp.c
>> > @@ -0,0 +1,82 @@
>> > +/*-
>> > + * 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 <rte_tcp.h>
>> > +
>> > +#include "gso_common.h"
>> > +#include "gso_tcp.h"
>> > +
>> > +int
>> > +gso_tcp4_segment(struct rte_mbuf *pkt,
>> > + uint16_t gso_size,
>> > + struct rte_mempool *direct_pool,
>> > + struct rte_mempool *indirect_pool,
>> > + struct rte_mbuf **pkts_out,
>> > + uint16_t nb_pkts_out)
>> > +{
>> > + struct ether_hdr *eth_hdr;
>> > + struct ipv4_hdr *ipv4_hdr;
>> > + uint16_t tcp_dl;
>> > + uint16_t pyld_unit_size;
>> > + uint16_t hdr_offset;
>> > + int ret = 1;
>> > +
>> > + eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
>> > + ipv4_hdr = (struct ipv4_hdr *)((char *)eth_hdr + pkt->l2_len);
>> > +
>> > + /* don't process fragmented packet */
>> > + if ((ipv4_hdr->fragment_offset &
>> > + rte_cpu_to_be_16(IPV4_HDR_DF_MASK)) == 0)
>> > + return ret;
>> > +
>> > + tcp_dl = rte_be_to_cpu_16(ipv4_hdr->total_length) -
>> > + pkt->l3_len - pkt->l4_len;
>> > + /* don't process packet without data */
>> > + if (tcp_dl == 0)
>> > + return ret;
>> > +
>> > + hdr_offset = pkt->l2_len + pkt->l3_len + pkt->l4_len;
>> > + pyld_unit_size = gso_size - hdr_offset - ETHER_CRC_LEN;
>> > +
>> > + /* 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)
>> > + gso_update_pkt_headers(pkt, ret, pkts_out);
>> > +
>> > + return ret;
>> > +}
>> > diff --git a/lib/librte_gso/gso_tcp.h b/lib/librte_gso/gso_tcp.h
>> > new file mode 100644
>> > index 0000000..f291ccb
>> > --- /dev/null
>> > +++ b/lib/librte_gso/gso_tcp.h
>> > @@ -0,0 +1,73 @@
>> > +/*-
>> > + * 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_TCP_H_
>> > +#define _GSO_TCP_H_
>> > +
>> > +#include <stdint.h>
>> > +#include <rte_mbuf.h>
>> > +
>> > +/**
>> > + * Segment an IPv4/TCP packet. This function assumes the input packet has
>> > + * correct checksums and doesn't update checksums for GSO segment.
>> > + * 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 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, which is used to store mbuf addresses of GSO segments.
>> > + * Caller should guarantee that 'pkts_out' is sufficiently large to
>store
>> > + * all GSO segments.
>> > + * @param nb_pkts_out
>> > + * The max number of items that 'pkts_out' can keep.
>> > + *
>> > + * @return
>> > + * - The number of GSO segments on success.
>> > + * - Return 1 if no GSO is performed.
>> > + * - Return -ENOMEM if available memory in mempools is insufficient.
>> > + * - Return -EINVAL for invalid parameters.
>> > + */
>> > +int gso_tcp4_segment(struct rte_mbuf *pkt,
>> > + uint16_t gso_size,
>> > + 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 b81afce..fac95f2 100644
>> > --- a/lib/librte_gso/rte_gso.c
>> > +++ b/lib/librte_gso/rte_gso.c
>> > @@ -31,17 +31,57 @@
>> > * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
>> > */
>> >
>> > +#include <rte_log.h>
>> > +
>> > #include "rte_gso.h"
>> > +#include "gso_common.h"
>> > +#include "gso_tcp.h"
>> >
>> > int
>> > rte_gso_segment(struct rte_mbuf *pkt,
>> > struct rte_gso_ctx gso_ctx,
>> > struct rte_mbuf **pkts_out,
>> > - uint16_t nb_pkts_out __rte_unused)
>> > + uint16_t nb_pkts_out)
>> > {
>> > + struct rte_mempool *direct_pool, *indirect_pool;
>> > + struct rte_mbuf *pkt_seg;
>> > + uint16_t nb_segments, gso_size;
>> > +
>> > if (pkt == NULL || pkts_out == NULL || gso_ctx.direct_pool ==
>> > NULL || gso_ctx.indirect_pool == NULL)
>> > return -EINVAL;
>>
>> Probably we don't need to check gso_ctx values for each incoming packet.
>> If you feel it is necessary - create new function rte_gso_ctx_check() that
>> could be performed just once per ctx.
>
>Agree. I will change it. Thanks.
>
>>
>> >
>> > - return 1;
>> > + if ((gso_ctx.gso_types & RTE_GSO_TCP_IPV4) == 0 ||
>> > + gso_ctx.gso_size >= pkt->pkt_len ||
>> > + gso_ctx.gso_size == 0)
>>
>>
>> First and third condition seems redundant.
>
>The reason to check gso_ctx.gso_types here is that we don't perform
>GSO if applications don't set RTE_GSO_TCP_IPV4 to gso_ctx.gso_types,
>even the input packet is TCP/IPv4. And if gso_ctx.gso_size is 0,
>we don't need to execute the following codes. So we still need to
>remove these two conditions?
>
>>
>> > + return 1;
>>
>>
>> I think you forgot here:
>> pkts_out[0] = pkt;
>
>But why should we keep the input packet in the output array? Currently, if
>GSO is not performed, no packets will be kept in pkts_out[]. Applications
>can know it by the return value 1 of rte_gso_segment().
>
>>
>>
>> > +
>> > + pkt_seg = pkt;
>> > + gso_size = gso_ctx.gso_size;
>> > + direct_pool = gso_ctx.direct_pool;
>> > + indirect_pool = gso_ctx.indirect_pool;
>> > +
>> > + /* Parse packet headers to determine how to segment 'pkt' */
>> > + gso_parse_packet(pkt);
>>
>>
>> I don't think we need to parse packet here.
>> Instead assume that user already filled packet_type and l2/l3/..._len
>fields correctly.
>
>Hmm, I see it. Thanks.
>
>Thanks,
>Jiayu
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