Hi Jiayu,
>
> In this patch, we introduce five APIs to support TCP/IPv4 GRO.
> - gro_tcp_tbl_create: create a TCP reassembly table, which is used to
> merge packets.
> - gro_tcp_tbl_destroy: free memory space of a TCP reassembly table.
> - gro_tcp_tbl_flush: flush all packets from a TCP reassembly table.
> - gro_tcp_tbl_timeout_flush: flush timeout packets from a TCP
> reassembly table.
> - gro_tcp4_reassemble: reassemble an inputted TCP/IPv4 packet.
>
> TCP/IPv4 GRO API assumes all inputted packets are with correct IPv4
> and TCP checksums. And TCP/IPv4 GRO API doesn't update IPv4 and TCP
> checksums for merged packets. If inputted packets are IP fragmented,
> TCP/IPv4 GRO API assumes they are complete packets (i.e. with L4
> headers).
>
> In TCP GRO, we use a table structure, called TCP reassembly table, to
> reassemble packets. Both TCP/IPv4 and TCP/IPv6 GRO use the same table
> structure. A TCP reassembly table includes a key array and a item array,
> where the key array keeps the criteria to merge packets and the item
> array keeps packet information.
>
> One key in the key array points to an item group, which consists of
> packets which have the same criteria value. If two packets are able to
> merge, they must be in the same item group. Each key in the key array
> includes two parts:
> - criteria: the criteria of merging packets. If two packets can be
> merged, they must have the same criteria value.
> - start_index: the index of the first incoming packet of the item group.
>
> Each element in the item array keeps the information of one packet. It
> mainly includes two parts:
> - pkt: packet address
> - next_pkt_index: the index of the next packet in the same item group.
> All packets in the same item group are chained by next_pkt_index.
> With next_pkt_index, we can locate all packets in the same item
> group one by one.
>
> To process an incoming packet needs three steps:
> a. check if the packet should be processed. Packets with the following
> properties won't be processed:
> - packets without data (e.g. SYN, SYN-ACK)
> b. traverse the key array to find a key which has the same criteria
> value with the incoming packet. If find, goto step c. Otherwise,
> insert a new key and insert the packet into the item array.
> c. locate the first packet in the item group via the start_index in the
> key. Then traverse all packets in the item group via next_pkt_index.
> If find one packet which can merge with the incoming one, merge them
> together. If can't find, insert the packet into this item group.
>
> Signed-off-by: Jiayu Hu <jiayu...@intel.com>
> ---
> doc/guides/rel_notes/release_17_08.rst | 7 +
> lib/librte_gro/Makefile | 1 +
> lib/librte_gro/rte_gro.c | 123 ++++++++--
> lib/librte_gro/rte_gro.h | 6 +-
> lib/librte_gro/rte_gro_tcp.c | 394
> +++++++++++++++++++++++++++++++++
> lib/librte_gro/rte_gro_tcp.h | 191 ++++++++++++++++
> 6 files changed, 706 insertions(+), 16 deletions(-)
> create mode 100644 lib/librte_gro/rte_gro_tcp.c
> create mode 100644 lib/librte_gro/rte_gro_tcp.h
>
> diff --git a/doc/guides/rel_notes/release_17_08.rst
> b/doc/guides/rel_notes/release_17_08.rst
> index 842f46f..f067247 100644
> --- a/doc/guides/rel_notes/release_17_08.rst
> +++ b/doc/guides/rel_notes/release_17_08.rst
> @@ -75,6 +75,13 @@ New Features
>
> Added support for firmwares with multiple Ethernet ports per physical port.
>
> +* **Add Generic Receive Offload API support.**
> +
> + Generic Receive Offload (GRO) API supports to reassemble TCP/IPv4
> + packets. GRO API assumes all inputted packets are with correct
> + checksums. GRO API doesn't update checksums for merged packets. If
> + inputted packets are IP fragmented, GRO API assumes they are complete
> + packets (i.e. with L4 headers).
>
> Resolved Issues
> ---------------
> diff --git a/lib/librte_gro/Makefile b/lib/librte_gro/Makefile
> index 7e0f128..e89344d 100644
> --- a/lib/librte_gro/Makefile
> +++ b/lib/librte_gro/Makefile
> @@ -43,6 +43,7 @@ LIBABIVER := 1
>
> # source files
> SRCS-$(CONFIG_RTE_LIBRTE_GRO) += rte_gro.c
> +SRCS-$(CONFIG_RTE_LIBRTE_GRO) += rte_gro_tcp.c
>
> # install this header file
> SYMLINK-$(CONFIG_RTE_LIBRTE_GRO)-include += rte_gro.h
> diff --git a/lib/librte_gro/rte_gro.c b/lib/librte_gro/rte_gro.c
> index 33275e8..5b89928 100644
> --- a/lib/librte_gro/rte_gro.c
> +++ b/lib/librte_gro/rte_gro.c
> @@ -32,11 +32,15 @@
>
> #include <rte_malloc.h>
> #include <rte_mbuf.h>
> +#include <rte_ethdev.h>
>
> #include "rte_gro.h"
> +#include "rte_gro_tcp.h"
>
> -static gro_tbl_create_fn tbl_create_functions[GRO_TYPE_MAX_NUM];
> -static gro_tbl_destroy_fn tbl_destroy_functions[GRO_TYPE_MAX_NUM];
> +static gro_tbl_create_fn tbl_create_functions[GRO_TYPE_MAX_NUM] = {
> + gro_tcp_tbl_create, NULL};
> +static gro_tbl_destroy_fn tbl_destroy_functions[GRO_TYPE_MAX_NUM] = {
> + gro_tcp_tbl_destroy, NULL};
>
> struct rte_gro_tbl *rte_gro_tbl_create(uint16_t socket_id,
> uint16_t max_flow_num,
> @@ -94,32 +98,121 @@ void rte_gro_tbl_destroy(struct rte_gro_tbl *gro_tbl)
> }
>
> uint16_t
> -rte_gro_reassemble_burst(struct rte_mbuf **pkts __rte_unused,
> +rte_gro_reassemble_burst(struct rte_mbuf **pkts,
> const uint16_t nb_pkts,
> - const struct rte_gro_param param __rte_unused)
> + const struct rte_gro_param param)
> {
> - return nb_pkts;
> + uint16_t i;
> + uint16_t nb_after_gro = nb_pkts;
> + uint32_t item_num = RTE_MIN(nb_pkts, param.max_flow_num *
> + param.max_item_per_flow);
> +
> + /* allocate a reassembly table for TCP/IPv4 GRO */
> + uint32_t tcp_item_num = RTE_MIN(item_num, GRO_MAX_BURST_ITEM_NUM);
> + struct gro_tcp_tbl tcp_tbl;
> + struct gro_tcp_key tcp_keys[tcp_item_num];
> + struct gro_tcp_item tcp_items[tcp_item_num];
> +
> + struct rte_mbuf *unprocess_pkts[nb_pkts];
> + uint16_t unprocess_num = 0;
> + int32_t ret;
> +
> + memset(tcp_keys, 0, sizeof(struct gro_tcp_key) *
> + tcp_item_num);
> + memset(tcp_items, 0, sizeof(struct gro_tcp_item) *
> + tcp_item_num);
> + tcp_tbl.keys = tcp_keys;
> + tcp_tbl.items = tcp_items;
> + tcp_tbl.key_num = 0;
> + tcp_tbl.item_num = 0;
> + tcp_tbl.max_key_num = tcp_item_num;
> + tcp_tbl.max_item_num = tcp_item_num;
> +
> + for (i = 0; i < nb_pkts; i++) {
> + if (RTE_ETH_IS_IPV4_HDR(pkts[i]->packet_type)) {
Why just not && for these 2 conditions?
> + if ((pkts[i]->packet_type & RTE_PTYPE_L4_TCP) &&
> + (param.desired_gro_types &
> + GRO_TCP_IPV4)) {
No need to check param.desired_gro_types inside the loop.
You can do that before the loop.
> + ret = gro_tcp4_reassemble(pkts[i],
> + &tcp_tbl,
> + param.max_packet_size);
> + /* merge successfully */
> + if (ret > 0)
> + nb_after_gro--;
> + else if (ret < 0)
> + unprocess_pkts[unprocess_num++] =
> + pkts[i];
> + } else
> + unprocess_pkts[unprocess_num++] =
> + pkts[i];
> + } else
> + unprocess_pkts[unprocess_num++] =
> + pkts[i];
> + }
> +
> + /* re-arrange GROed packets */
> + if (nb_after_gro < nb_pkts) {
> + if (param.desired_gro_types & GRO_TCP_IPV4)
> + i = gro_tcp_tbl_flush(&tcp_tbl, pkts, nb_pkts);
> + if (unprocess_num > 0) {
> + memcpy(&pkts[i], unprocess_pkts,
> + sizeof(struct rte_mbuf *) *
> + unprocess_num);
> + i += unprocess_num;
> + }
> + if (nb_pkts > i)
> + memset(&pkts[i], 0,
> + sizeof(struct rte_mbuf *) *
> + (nb_pkts - i));
> + }
Why do you need to zero remaining pkts[]?
> + return nb_after_gro;
> }
>
> -int rte_gro_reassemble(struct rte_mbuf *pkt __rte_unused,
> - struct rte_gro_tbl *gro_tbl __rte_unused)
> +int rte_gro_reassemble(struct rte_mbuf *pkt,
> + struct rte_gro_tbl *gro_tbl)
> {
> + if (unlikely(pkt == NULL))
> + return -1;
> +
> + if (RTE_ETH_IS_IPV4_HDR(pkt->packet_type)) {
> + if ((pkt->packet_type & RTE_PTYPE_L4_TCP) &&
> + (gro_tbl->desired_gro_types &
> + GRO_TCP_IPV4))
> + return gro_tcp4_reassemble(pkt,
> + gro_tbl->tbls[GRO_TCP_IPV4_INDEX],
> + gro_tbl->max_packet_size);
> + }
> +
> return -1;
> }
>
> -uint16_t rte_gro_flush(struct rte_gro_tbl *gro_tbl __rte_unused,
> - uint64_t desired_gro_types __rte_unused,
> - struct rte_mbuf **out __rte_unused,
> - const uint16_t max_nb_out __rte_unused)
> +uint16_t rte_gro_flush(struct rte_gro_tbl *gro_tbl,
> + uint64_t desired_gro_types,
> + struct rte_mbuf **out,
> + const uint16_t max_nb_out)
> {
> + desired_gro_types = desired_gro_types &
> + gro_tbl->desired_gro_types;
> + if (desired_gro_types & GRO_TCP_IPV4)
> + return gro_tcp_tbl_flush(
> + gro_tbl->tbls[GRO_TCP_IPV4_INDEX],
> + out,
> + max_nb_out);
> return 0;
> }
>
> uint16_t
> -rte_gro_timeout_flush(struct rte_gro_tbl *gro_tbl __rte_unused,
> - uint64_t desired_gro_types __rte_unused,
> - struct rte_mbuf **out __rte_unused,
> - const uint16_t max_nb_out __rte_unused)
> +rte_gro_timeout_flush(struct rte_gro_tbl *gro_tbl,
> + uint64_t desired_gro_types,
> + struct rte_mbuf **out,
> + const uint16_t max_nb_out)
> {
> + desired_gro_types = desired_gro_types &
> + gro_tbl->desired_gro_types;
> + if (desired_gro_types & GRO_TCP_IPV4)
> + return gro_tcp_tbl_timeout_flush(
> + gro_tbl->tbls[GRO_TCP_IPV4_INDEX],
> + gro_tbl->max_timeout_cycles,
> + out, max_nb_out);
> return 0;
> }
> diff --git a/lib/librte_gro/rte_gro.h b/lib/librte_gro/rte_gro.h
> index f9d36e8..a30b1c6 100644
> --- a/lib/librte_gro/rte_gro.h
> +++ b/lib/librte_gro/rte_gro.h
> @@ -45,7 +45,11 @@ extern "C" {
>
> /* max number of supported GRO types */
> #define GRO_TYPE_MAX_NUM 64
> -#define GRO_TYPE_SUPPORT_NUM 0 /**< current supported GRO num */
> +#define GRO_TYPE_SUPPORT_NUM 1 /**< current supported GRO num */
> +
> +/* TCP/IPv4 GRO flag */
> +#define GRO_TCP_IPV4_INDEX 0
> +#define GRO_TCP_IPV4 (1ULL << GRO_TCP_IPV4_INDEX)
>
> /**
> * GRO table, which is used to merge packets. It keeps many reassembly
> diff --git a/lib/librte_gro/rte_gro_tcp.c b/lib/librte_gro/rte_gro_tcp.c
> new file mode 100644
> index 0000000..c0eaa45
> --- /dev/null
> +++ b/lib/librte_gro/rte_gro_tcp.c
> @@ -0,0 +1,394 @@
> +/*-
> + * BSD LICENSE
> + *
> + * Copyright(c) 2017 Intel Corporation. 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_malloc.h>
> +#include <rte_mbuf.h>
> +#include <rte_cycles.h>
> +
> +#include <rte_ethdev.h>
> +#include <rte_ip.h>
> +#include <rte_tcp.h>
> +
> +#include "rte_gro_tcp.h"
> +
> +void *gro_tcp_tbl_create(uint16_t socket_id,
> + uint16_t max_flow_num,
> + uint16_t max_item_per_flow)
> +{
> + size_t size;
> + uint32_t entries_num;
> + struct gro_tcp_tbl *tbl;
> +
> + entries_num = max_flow_num * max_item_per_flow;
> + entries_num = entries_num > GRO_TCP_TBL_MAX_ITEM_NUM ?
> + GRO_TCP_TBL_MAX_ITEM_NUM : entries_num;
> +
> + if (entries_num == 0)
> + return NULL;
> +
> + tbl = (struct gro_tcp_tbl *)rte_zmalloc_socket(
> + __func__,
> + sizeof(struct gro_tcp_tbl),
> + RTE_CACHE_LINE_SIZE,
> + socket_id);
Here and everywhere - rte_malloc() can fail.
Add proper error handling.
> +
> + size = sizeof(struct gro_tcp_item) * entries_num;
> + tbl->items = (struct gro_tcp_item *)rte_zmalloc_socket(
> + __func__,
> + size,
> + RTE_CACHE_LINE_SIZE,
> + socket_id);
> + tbl->max_item_num = entries_num;
> +
> + size = sizeof(struct gro_tcp_key) * entries_num;
> + tbl->keys = (struct gro_tcp_key *)rte_zmalloc_socket(
> + __func__,
> + size, RTE_CACHE_LINE_SIZE,
> + socket_id);
> + tbl->max_key_num = entries_num;
> + return tbl;
> +}
> +
> +void gro_tcp_tbl_destroy(void *tbl)
> +{
> + struct gro_tcp_tbl *tcp_tbl = (struct gro_tcp_tbl *)tbl;
> +
> + if (tcp_tbl) {
> + if (tcp_tbl->items)
No need to, rte_free(NULL) is a valid construction.
Same below.
> + rte_free(tcp_tbl->items);
> + if (tcp_tbl->keys)
> + rte_free(tcp_tbl->keys);
> + rte_free(tcp_tbl);
> + }
> +}
> +
> +/**
> + * merge two TCP/IPv4 packets without update checksums.
> + */
> +static int
> +merge_two_tcp4_packets(struct rte_mbuf *pkt_src,
> + struct rte_mbuf *pkt,
> + uint32_t max_packet_size)
> +{
> + struct ipv4_hdr *ipv4_hdr1, *ipv4_hdr2;
> + struct tcp_hdr *tcp_hdr1;
> + uint16_t ipv4_ihl1, tcp_hl1, tcp_dl1;
> + struct rte_mbuf *tail;
> +
> + /* parse the given packet */
> + ipv4_hdr1 = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt,
> + struct ether_hdr *) + 1);
You probably shouldn't assume that l2_len is always 14B long.
> + ipv4_ihl1 = IPv4_HDR_LEN(ipv4_hdr1);
> + tcp_hdr1 = (struct tcp_hdr *)((char *)ipv4_hdr1 + ipv4_ihl1);
> + tcp_hl1 = TCP_HDR_LEN(tcp_hdr1);
> + tcp_dl1 = rte_be_to_cpu_16(ipv4_hdr1->total_length) - ipv4_ihl1
> + - tcp_hl1;
> +
> + /* parse the original packet */
> + ipv4_hdr2 = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt_src,
> + struct ether_hdr *) + 1);
> +
> + if (pkt_src->pkt_len + tcp_dl1 > max_packet_size)
> + return -1;
> +
> + /* remove the header of the incoming packet */
> + rte_pktmbuf_adj(pkt, sizeof(struct ether_hdr) +
> + ipv4_ihl1 + tcp_hl1);
> +
> + /* chain the two packet together */
> + tail = rte_pktmbuf_lastseg(pkt_src);
> + tail->next = pkt;
What I see as a problem here:
You have to reparse your packet and do lastseg for it for each new segment.
That seems like a big overhead.
Would be good instead to parse the packet once and then store that infomatio
inside mbuf: l2_len/l3_len/l4_len, etc.
You can probably even avoid parsing inside your library - by adding as a
prerequisite
for the caller to fill these fields properly.
Similar thought about lastseg - would be good to store it somewhere inside your
table.
> +
> + /* update IP header */
> + ipv4_hdr2->total_length = rte_cpu_to_be_16(
> + rte_be_to_cpu_16(
> + ipv4_hdr2->total_length)
> + + tcp_dl1);
> +
> + /* update mbuf metadata for the merged packet */
> + pkt_src->nb_segs++;
Why do you assume that incoming packet always contains only one segment?
> + pkt_src->pkt_len += pkt->pkt_len;
> + return 1;
> +}
> +
> +static int
> +check_seq_option(struct rte_mbuf *pkt,
> + struct tcp_hdr *tcp_hdr,
> + uint16_t tcp_hl)
> +{
> + struct ipv4_hdr *ipv4_hdr1;
> + struct tcp_hdr *tcp_hdr1;
> + uint16_t ipv4_ihl1, tcp_hl1, tcp_dl1;
> + uint32_t sent_seq1, sent_seq;
> + int ret = -1;
> +
> + ipv4_hdr1 = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt,
> + struct ether_hdr *) + 1);
> + ipv4_ihl1 = IPv4_HDR_LEN(ipv4_hdr1);
> + tcp_hdr1 = (struct tcp_hdr *)((char *)ipv4_hdr1 + ipv4_ihl1);
> + tcp_hl1 = TCP_HDR_LEN(tcp_hdr1);
> + tcp_dl1 = rte_be_to_cpu_16(ipv4_hdr1->total_length) - ipv4_ihl1
> + - tcp_hl1;
> + sent_seq1 = rte_be_to_cpu_32(tcp_hdr1->sent_seq) + tcp_dl1;
> + sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
> +
> + /* check if the two packets are neighbor */
> + if ((sent_seq ^ sent_seq1) == 0) {
Why just not if sent_seq == sent_seq1?
> + /* check if TCP option field equals */
> + if (tcp_hl1 > sizeof(struct tcp_hdr)) {
And what if tcp_hl1 == sizeof(struct tcp_hdr), but tcp_hl > tcp_hl1?
I think you need to remove that check.
> + if ((tcp_hl1 != tcp_hl) ||
> + (memcmp(tcp_hdr1 + 1,
> + tcp_hdr + 1,
> + tcp_hl - sizeof
> + (struct tcp_hdr))
> + == 0))
> + ret = 1;
> + }
> + }
> + return ret;
> +}
> +
> +static uint32_t
> +find_an_empty_item(struct gro_tcp_tbl *tbl)
> +{
> + uint32_t i;
> +
> + for (i = 0; i < tbl->max_item_num; i++)
> + if (tbl->items[i].is_valid == 0)
> + return i;
> + return INVALID_ARRAY_INDEX;
> +}
> +
> +static uint32_t
> +find_an_empty_key(struct gro_tcp_tbl *tbl)
> +{
> + uint32_t i;
> +
> + for (i = 0; i < tbl->max_key_num; i++)
> + if (tbl->keys[i].is_valid == 0)
> + return i;
> + return INVALID_ARRAY_INDEX;
> +}
> +
> +int32_t
> +gro_tcp4_reassemble(struct rte_mbuf *pkt,
> + struct gro_tcp_tbl *tbl,
> + uint32_t max_packet_size)
> +{
> + struct ether_hdr *eth_hdr;
> + struct ipv4_hdr *ipv4_hdr;
> + struct tcp_hdr *tcp_hdr;
> + uint16_t ipv4_ihl, tcp_hl, tcp_dl;
> +
> + struct tcp_key key;
> + uint32_t cur_idx, prev_idx, item_idx;
> + uint32_t i, key_idx;
> +
> + eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
> + ipv4_hdr = (struct ipv4_hdr *)(eth_hdr + 1);
> + ipv4_ihl = IPv4_HDR_LEN(ipv4_hdr);
> +
> + /* check if the packet should be processed */
> + if (ipv4_ihl < sizeof(struct ipv4_hdr))
> + goto fail;
> + tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + ipv4_ihl);
> + tcp_hl = TCP_HDR_LEN(tcp_hdr);
> + tcp_dl = rte_be_to_cpu_16(ipv4_hdr->total_length) - ipv4_ihl
> + - tcp_hl;
> + if (tcp_dl == 0)
> + goto fail;
> +
> + /* find a key and traverse all packets in its item group */
> + key.eth_saddr = eth_hdr->s_addr;
> + key.eth_daddr = eth_hdr->d_addr;
> + key.ip_src_addr[0] = rte_be_to_cpu_32(ipv4_hdr->src_addr);
> + key.ip_dst_addr[0] = rte_be_to_cpu_32(ipv4_hdr->dst_addr);
Your key.ip_src_addr[1-3] still contains some junk.
How memcmp below supposed to worj properly?
BTW why do you need 4 elems here, why just not uint32_t ip_src_addr;?
Same for ip_dst_addr.
> + key.src_port = rte_be_to_cpu_16(tcp_hdr->src_port);
> + key.dst_port = rte_be_to_cpu_16(tcp_hdr->dst_port);
> + key.recv_ack = rte_be_to_cpu_32(tcp_hdr->recv_ack);
> + key.tcp_flags = tcp_hdr->tcp_flags;
> +
> + for (i = 0; i < tbl->max_key_num; i++) {
> + if (tbl->keys[i].is_valid &&
> + (memcmp(&(tbl->keys[i].key), &key,
> + sizeof(struct tcp_key))
> + == 0)) {
> + cur_idx = tbl->keys[i].start_index;
> + prev_idx = cur_idx;
> + while (cur_idx != INVALID_ARRAY_INDEX) {
> + if (check_seq_option(tbl->items[cur_idx].pkt,
> + tcp_hdr,
> + tcp_hl) > 0) {
As I remember linux gro also check ipv4 packet_id - it should be consecutive.
> + if (merge_two_tcp4_packets(
> +
> tbl->items[cur_idx].pkt,
> + pkt,
> +
> max_packet_size) > 0) {
> + /* successfully merge two
> packets */
> + tbl->items[cur_idx].is_groed =
> 1;
> + return 1;
> + }
If you allow more then packet per flow to be stored in the table, then you
should be
prepared that new segment can fill a gap between 2 packets.
Probably the easiest thing - don't allow more then one 'item' per flow.
> + /**
> + * fail to merge two packets since
> + * it's beyond the max packet length.
> + * Insert it into the item group.
> + */
> + goto insert_to_item_group;
> + } else {
> + prev_idx = cur_idx;
> + cur_idx =
> tbl->items[cur_idx].next_pkt_idx;
> + }
> + }
> + /**
> + * find a corresponding item group but fails to find
> + * one packet to merge. Insert it into this item group.
> + */
> +insert_to_item_group:
> + item_idx = find_an_empty_item(tbl);
> + /* the item number is greater than the max value */
> + if (item_idx == INVALID_ARRAY_INDEX)
> + return -1;
> + tbl->items[prev_idx].next_pkt_idx = item_idx;
> + tbl->items[item_idx].pkt = pkt;
> + tbl->items[item_idx].is_groed = 0;
> + tbl->items[item_idx].next_pkt_idx = INVALID_ARRAY_INDEX;
> + tbl->items[item_idx].is_valid = 1;
> + tbl->items[item_idx].start_time = rte_rdtsc();
> + tbl->item_num++;
> + return 0;
> + }
> + }
> +
> + /**
> + * merge fail as the given packet has a new key.
> + * So insert a new key.
> + */
> + item_idx = find_an_empty_item(tbl);
> + key_idx = find_an_empty_key(tbl);
> + /**
> + * if current key or item number is greater than the max
> + * value, don't insert the packet into the table and return
> + * immediately.
> + */
> + if (item_idx == INVALID_ARRAY_INDEX ||
> + key_idx == INVALID_ARRAY_INDEX)
> + return -1;
> + tbl->items[item_idx].pkt = pkt;
> + tbl->items[item_idx].next_pkt_idx = INVALID_ARRAY_INDEX;
> + tbl->items[item_idx].is_groed = 0;
> + tbl->items[item_idx].is_valid = 1;
> + tbl->items[item_idx].start_time = rte_rdtsc();
You can pass start-time as a parameter instead.
> + tbl->item_num++;
> +
> + memcpy(&(tbl->keys[key_idx].key),
> + &key, sizeof(struct tcp_key));
> + tbl->keys[key_idx].start_index = item_idx;
> + tbl->keys[key_idx].is_valid = 1;
> + tbl->key_num++;
> +
> + return 0;
> +fail:
Please try to avoid goto whenever possible.
Looks really ugly.
> + return -1;
> +}
> +
> +uint16_t gro_tcp_tbl_flush(struct gro_tcp_tbl *tbl,
> + struct rte_mbuf **out,
> + const uint16_t nb_out)
> +{
> + uint32_t i, num = 0;
> +
> + if (nb_out < tbl->item_num)
> + return 0;
And how user would now how many items are now in the table?
> +
> + for (i = 0; i < tbl->max_item_num; i++) {
> + if (tbl->items[i].is_valid) {
> + out[num++] = tbl->items[i].pkt;
> + tbl->items[i].is_valid = 0;
> + tbl->item_num--;
> + }
> + }
> + memset(tbl->keys, 0, sizeof(struct gro_tcp_key) *
> + tbl->max_key_num);
> + tbl->key_num = 0;
> +
> + return num;
> +}
> +
> +uint16_t
> +gro_tcp_tbl_timeout_flush(struct gro_tcp_tbl *tbl,
> + uint64_t timeout_cycles,
> + struct rte_mbuf **out,
> + const uint16_t nb_out)
> +{
> + uint16_t k;
> + uint32_t i, j;
> + uint64_t current_time;
> +
> + if (nb_out == 0)
> + return 0;
> + k = 0;
> + current_time = rte_rdtsc();
> +
> + for (i = 0; i < tbl->max_key_num; i++) {
> + if (tbl->keys[i].is_valid) {
Seems pretty expensive to traverse the whole table...
Would it worth to have some sort of LRU list?
> + j = tbl->keys[i].start_index;
> + while (j != INVALID_ARRAY_INDEX) {
> + if (current_time - tbl->items[j].start_time >=
> + timeout_cycles) {
> + out[k++] = tbl->items[j].pkt;
> + tbl->items[j].is_valid = 0;
> + tbl->item_num--;
> + j = tbl->items[j].next_pkt_idx;
> +
> + if (k == nb_out &&
> + j ==
> INVALID_ARRAY_INDEX) {
> + /* delete the key */
> + tbl->keys[i].is_valid = 0;
> + tbl->key_num--;
> + goto end;
Please rearrange the code to avoid gotos.
> + } else if (k == nb_out &&
> + j !=
> INVALID_ARRAY_INDEX) {
> + /* update the first item index
> */
> + tbl->keys[i].start_index = j;
> + goto end;
> + }
> + }
> + }
> + /* delete the key, as all of its packets are flushed */
> + tbl->keys[i].is_valid = 0;
> + tbl->key_num--;
> + }
> + if (tbl->key_num == 0)
> + goto end;
> + }
> +end:
> + return k;
> +}
> diff --git a/lib/librte_gro/rte_gro_tcp.h b/lib/librte_gro/rte_gro_tcp.h
> new file mode 100644
> index 0000000..a9a7aca
> --- /dev/null
> +++ b/lib/librte_gro/rte_gro_tcp.h
> @@ -0,0 +1,191 @@
> +/*-
> + * BSD LICENSE
> + *
> + * Copyright(c) 2017 Intel Corporation. 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 _RTE_GRO_TCP_H_
> +#define _RTE_GRO_TCP_H_
> +
> +#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
> +#define TCP_HDR_LEN(tcph) \
> + ((tcph->data_off >> 4) * 4)
> +#define IPv4_HDR_LEN(iph) \
> + ((iph->version_ihl & 0x0f) * 4)
> +#else
> +#define TCP_DATAOFF_MASK 0x0f
> +#define TCP_HDR_LEN(tcph) \
> + ((tcph->data_off & TCP_DATAOFF_MASK) * 4)
> +#define IPv4_HDR_LEN(iph) \
> + ((iph->version_ihl >> 4) * 4)
> +#endif
> +
> +#define INVALID_ARRAY_INDEX 0xffffffffUL
> +#define GRO_TCP_TBL_MAX_ITEM_NUM (UINT32_MAX - 1)
> +
> +/* criteria of mergeing packets */
> +struct tcp_key {
> + struct ether_addr eth_saddr;
> + struct ether_addr eth_daddr;
> + uint32_t ip_src_addr[4]; /**< IPv4 uses the first 8B */
> + uint32_t ip_dst_addr[4];
> +
> + uint32_t recv_ack; /**< acknowledgment sequence number. */
> + uint16_t src_port;
> + uint16_t dst_port;
> + uint8_t tcp_flags; /**< TCP flags. */
> +};
> +
> +struct gro_tcp_key {
> + struct tcp_key key;
> + uint32_t start_index; /**< the first packet index of the flow */
> + uint8_t is_valid;
> +};
> +
> +struct gro_tcp_item {
> + struct rte_mbuf *pkt; /**< packet address. */
> + /* the time when the packet in added into the table */
> + uint64_t start_time;
> + uint32_t next_pkt_idx; /**< next packet index. */
> + /* flag to indicate if the packet is GROed */
> + uint8_t is_groed;
> + uint8_t is_valid; /**< flag indicates if the item is valid */
Why do you need these 2 flags at all?
Why not just reset let say pkt to NULL for invalid item?
> +};
> +
> +/**
> + * TCP reassembly table. Both TCP/IPv4 and TCP/IPv6 use the same table
> + * structure.
> + */
> +struct gro_tcp_tbl {
> + struct gro_tcp_item *items; /**< item array */
> + struct gro_tcp_key *keys; /**< key array */
> + uint32_t item_num; /**< current item number */
> + uint32_t key_num; /**< current key num */
> + uint32_t max_item_num; /**< item array size */
> + uint32_t max_key_num; /**< key array size */
> +};
> +
> +/**
> + * This function creates a TCP reassembly table.
> + *
> + * @param socket_id
> + * socket index where the Ethernet port connects to.
> + * @param max_flow_num
> + * the maximum number of flows in the TCP GRO table
> + * @param max_item_per_flow
> + * the maximum packet number per flow.
> + * @return
> + * if create successfully, return a pointer which points to the
> + * created TCP GRO table. Otherwise, return NULL.
> + */
> +void *gro_tcp_tbl_create(uint16_t socket_id,
> + uint16_t max_flow_num,
> + uint16_t max_item_per_flow);
> +
> +/**
> + * This function destroys a TCP reassembly table.
> + * @param tbl
> + * a pointer points to the TCP reassembly table.
> + */
> +void gro_tcp_tbl_destroy(void *tbl);
> +
> +/**
> + * This function searches for a packet in the TCP reassembly table to
> + * merge with the inputted one. To merge two packets is to chain them
> + * together and update packet headers. If the packet is without data
> + * (e.g. SYN, SYN-ACK packet), this function returns immediately.
> + * Otherwise, the packet is either merged, or inserted into the table.
> + * Besides, if there is no available space to insert the packet, this
> + * function returns immediately too.
> + *
> + * This function assumes the inputted packet is with correct IPv4 and
> + * TCP checksums. And if two packets are merged, it won't re-calculate
> + * IPv4 and TCP checksums. Besides, if the inputted packet is IP
> + * fragmented, it assumes the packet is complete (with TCP header).
> + *
> + * @param pkt
> + * packet to reassemble.
> + * @param tbl
> + * a pointer that points to a TCP reassembly table.
> + * @param max_packet_size
> + * max packet length after merged
> + * @return
> + * if the packet doesn't have data, or there is no available space
> + * in the table to insert a new item or a new key, return a negative
> + * value. If the packet is merged successfully, return an positive
> + * value. If the packet is inserted into the table, return 0.
> + */
> +int32_t
> +gro_tcp4_reassemble(struct rte_mbuf *pkt,
> + struct gro_tcp_tbl *tbl,
> + uint32_t max_packet_size);
> +
> +/**
> + * This function flushes all packets in a TCP reassembly table to
> + * applications, and without updating checksums for merged packets.
> + * If the array which is used to keep flushed packets is not large
> + * enough, error happens and this function returns immediately.
> + *
> + * @param tbl
> + * a pointer that points to a TCP GRO table.
> + * @param out
> + * pointer array which is used to keep flushed packets. Applications
> + * should guarantee it's large enough to hold all packets in the table.
> + * @param nb_out
> + * the element number of out.
> + * @return
> + * the number of flushed packets. If out is not large enough to hold
> + * all packets in the table, return 0.
> + */
> +uint16_t
> +gro_tcp_tbl_flush(struct gro_tcp_tbl *tbl,
> + struct rte_mbuf **out,
> + const uint16_t nb_out);
> +
> +/**
> + * This function flushes timeout packets in a TCP reassembly table to
> + * applications, and without updating checksums for merged packets.
> + *
> + * @param tbl
> + * a pointer that points to a TCP GRO table.
> + * @param timeout_cycles
> + * the maximum time that packets can stay in the table.
> + * @param out
> + * pointer array which is used to keep flushed packets.
> + * @param nb_out
> + * the element number of out.
> + * @return
> + * the number of packets that are returned.
> + */
> +uint16_t
> +gro_tcp_tbl_timeout_flush(struct gro_tcp_tbl *tbl,
> + uint64_t timeout_cycles,
> + struct rte_mbuf **out,
> + const uint16_t nb_out);
> +#endif
> --
> 2.7.4
