Hi Jianfeng,
On Mon, Jun 19, 2017 at 11:43:20PM +0800, Tan, Jianfeng wrote:
>
>
> On 6/18/2017 3:21 PM, Jiayu Hu wrote:
> > In this patch, we introduce six APIs to support TCP/IPv4 GRO.
>
> Those functions are not used outside of this library. Don't make it as
> extern visible.
But they are called by functions in rte_gro.c, which are in the different
file. If we define these functions with static, how can they be called by
other functions in the different file?
>
> > - gro_tcp_tbl_create: create a TCP reassembly table, which is used to
> > merge packets.
>
> Will tcp6 shares the same function with tcp4? If no, please rename it to
> gro_tcp4_tlb_create
In TCP GRO design, TCP4 and TCP6 will share a same table structure, but
they will have different reassembly function. Therefore, I use
gro_tcp_tlb_create instead of gro_tcp4_tlb_create here.
>
> > - gro_tcp_tbl_destroy: free memory space of a TCP reassembly table.
> > - gro_tcp_tbl_flush: flush packets in the TCP reassembly table.
> > - gro_tcp_tbl_timeout_flush: flush timeout packets in the TCP
> > reassembly table.
> > - gro_tcp4_reassemble: merge an inputted packet.
> > - gro_tcp4_tbl_cksum_update: update TCP and IPv4 header checksums for
> > all merged packets in the TCP reassembly table.
> >
> > 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 flow array and a item array,
> > where the flow array is used to record flow information and the item
> > array is used to record packets information.
> >
> > Each element in the flow array records the information of one flow,
> > which includes two parts:
> > - key: the criteria of the same flow. If packets have the same key
> > value, they belong to the same flow.
> > - start_index: the index of the first incoming packet of this flow in
> > the item array. With start_index, we can locate the first incoming
> > packet of this flow.
> > Each element in the item array records one packet information. It mainly
> > includes two parts:
> > - pkt: packet address
> > - next_pkt_index: index of the next packet of the same flow in the item
> > array. All packets of the same flow are chained by next_pkt_index.
> > With next_pkt_index, we can locate all packets of the same flow
> > one by one.
> >
> > To process an incoming packet, we need three steps:
> > a. check if the packet should be processed. Packets with the following
> > properties won't be processed:
> > - packets without data;
> > - packets with wrong checksums;
>
> Why do we care to check this kind of error? Can we just suppose the
> applications have already dropped the packets with wrong cksum?
Indeed, if we assume all inputted packets are correct, we can avoid
checksum checking overhead. But as a library, I think a more flexible
way is to enable applications to tell GRO API if checksum checking
is needed. For example, we can add a flag to struct rte_gro_tbl
and struct rte_gro_param, which indicates if the checksum checking
is needed. If applications set this flag, reassembly function won't
check packet checksum. Otherwise, we check the checksum. How do you
think?
>
> > - fragmented packets.
>
> IP fragmented? I don't think we need to check it here either. It's the
> application's responsibility to call librte_ip_frag firstly to reassemble
> IP-fragmented packets, and then call this gro library to merge TCP packets.
> And this procedure should be shown in an example for other users to refer.
>
> > b. traverse the flow array to find a flow which the packet belongs to.
> > If not find, insert a new flow and store the packet into the item
> > array.
>
> You do not store the packet now. "store the packet into the item array" ->
> "then go to step c".
Thanks, I will update it in next patch.
>
> > c. locate the first packet of this flow in the item array via
> > start_index. Then traverse all packets of this flow one by one via
> > next_pkt_index. If find one packet to merge with the incoming packet,
> > merge them but without updating checksums. If not, allocate one item
> > in the item array to store the incoming packet and update
> > next_pkt_index value.
> >
> > For better performance, we don't update header checksums once two
> > packets are merged. The header checksums are updated only when packets
> > are flushed from TCP reassembly tables.
>
> Why do we care to recalculate the L4 checksum when flushing? How about Just
> keeping the wrong cksum, and letting the applications to handle that?
Not all applications want GROed packets with wrong checksum. So I think a
more reasonable way is to give a flag to applications to tell GRO API if
they need calculate checksum when flush them from GRO table. How do you
think?
>
>
> >
> > Signed-off-by: Jiayu Hu <jiayu...@intel.com>
> > ---
> > lib/librte_gro/Makefile | 1 +
> > lib/librte_gro/rte_gro.c | 154 +++++++++++--
> > lib/librte_gro/rte_gro.h | 34 +--
> > lib/librte_gro/rte_gro_tcp.c | 527
> > +++++++++++++++++++++++++++++++++++++++++++
> > lib/librte_gro/rte_gro_tcp.h | 210 +++++++++++++++++
> > 5 files changed, 895 insertions(+), 31 deletions(-)
> > create mode 100644 lib/librte_gro/rte_gro_tcp.c
> > create mode 100644 lib/librte_gro/rte_gro_tcp.h
> >
> > diff --git a/lib/librte_gro/Makefile b/lib/librte_gro/Makefile
> > index 9f4063a..3495dfc 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
>
> Again, if it's just for tcp4, please use the name rte_gro_tcp4.c.
TCP4 and TCP6 reassembly functions will be placed in the same file,
rte_gro_tcp.c. But currently, we don't support TCP6 GRO.
>
> > # 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 1bc53a2..2620ef6 100644
> > --- a/lib/librte_gro/rte_gro.c
> > +++ b/lib/librte_gro/rte_gro.c
> > @@ -32,11 +32,17 @@
> > #include <rte_malloc.h>
> > #include <rte_mbuf.h>
> > +#include <rte_ethdev.h>
> > +#include <rte_ip.h>
> > +#include <rte_tcp.h>
> > #include "rte_gro.h"
> > +#include "rte_gro_tcp.h"
> > -static gro_tbl_create_fn tbl_create_functions[GRO_TYPE_MAX_NB];
> > -static gro_tbl_destroy_fn tbl_destroy_functions[GRO_TYPE_MAX_NB];
> > +static gro_tbl_create_fn tbl_create_functions[GRO_TYPE_MAX_NB] = {
> > + gro_tcp_tbl_create, NULL};
> > +static gro_tbl_destroy_fn tbl_destroy_functions[GRO_TYPE_MAX_NB] = {
> > + gro_tcp_tbl_destroy, NULL};
> > struct rte_gro_tbl *rte_gro_tbl_create(uint16_t socket_id,
> > uint16_t max_flow_num,
> > @@ -94,33 +100,149 @@ 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;
> > + struct ether_hdr *eth_hdr;
> > + struct ipv4_hdr *ipv4_hdr;
> > + uint16_t l3proc_type, i;
>
> I did not catch the variable definition here: l3proc_type -> l3_proto?
You can see it in line 158 and line 159.
>
> > + uint16_t nb_after_gro = nb_pkts;
> > + uint16_t flow_num = nb_pkts < param.max_flow_num ?
> > + nb_pkts : param.max_flow_num;
> > + uint32_t item_num = nb_pkts <
> > + flow_num * param.max_item_per_flow ?
> > + nb_pkts :
> > + flow_num * param.max_item_per_flow;
> > +
> > + /* allocate a reassembly table for TCP/IPv4 GRO */
> > + uint16_t tcp_flow_num = flow_num <= GRO_TCP_TBL_MAX_FLOW_NUM ?
> > + flow_num : GRO_TCP_TBL_MAX_FLOW_NUM;
> > + uint32_t tcp_item_num = item_num <= GRO_TCP_TBL_MAX_ITEM_NUM ?
> > + item_num : GRO_TCP_TBL_MAX_ITEM_NUM;
>
> Below tcpv4-specific logic should be in rte_gro_tcp4.c; here, as my previous
> comment, we iterate all ptypes of this packets to iterate all supported GRO
> engine.
Sorry, I don't get the point. The table which is created here is used by
gro_tcp4_reassemble when merges packets. If we don't create table here,
what does gro_tcp4_reassemble use to merge packets?
>
> > + struct gro_tcp_tbl tcp_tbl;
> > + struct gro_tcp_flow tcp_flows[tcp_flow_num];
> > + struct gro_tcp_item tcp_items[tcp_item_num];
> > + struct gro_tcp_rule tcp_rule;
> > +
> > + struct rte_mbuf *unprocess_pkts[nb_pkts];
> > + uint16_t unprocess_num = 0;
> > + int32_t ret;
> > +
> > + if (unlikely(nb_pkts <= 1))
> > + return nb_pkts;
> > +
> > + memset(tcp_flows, 0, sizeof(struct gro_tcp_flow) *
> > + tcp_flow_num);
> > + memset(tcp_items, 0, sizeof(struct gro_tcp_item) *
> > + tcp_item_num);
> > + tcp_tbl.flows = tcp_flows;
> > + tcp_tbl.items = tcp_items;
> > + tcp_tbl.flow_num = 0;
> > + tcp_tbl.item_num = 0;
> > + tcp_tbl.max_flow_num = tcp_flow_num;
> > + tcp_tbl.max_item_num = tcp_item_num;
> > + tcp_rule.max_packet_size = param.max_packet_size;
> > +
> > + for (i = 0; i < nb_pkts; i++) {
> > + eth_hdr = rte_pktmbuf_mtod(pkts[i], struct ether_hdr *);
> > + l3proc_type = rte_be_to_cpu_16(eth_hdr->ether_type);
> > + if (l3proc_type == ETHER_TYPE_IPv4) {
> > + ipv4_hdr = (struct ipv4_hdr *)(eth_hdr + 1);
> > + if (ipv4_hdr->next_proto_id == IPPROTO_TCP &&
> > + (param.desired_gro_types &
> > + GRO_TCP_IPV4)) {
> > + ret = gro_tcp4_reassemble(pkts[i],
> > + &tcp_tbl,
> > + &tcp_rule);
> > + 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];
> > + }
> > +
> > + if (nb_after_gro < nb_pkts) {
> > + /* update packets headers and re-arrange GROed packets */
> > + if (param.desired_gro_types & GRO_TCP_IPV4) {
> > + gro_tcp4_tbl_cksum_update(&tcp_tbl);
> > + for (i = 0; i < tcp_tbl.item_num; i++)
> > + pkts[i] = tcp_tbl.items[i].pkt;
> > + }
> > + 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));
> > + }
> > + 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)
> > {
> > + struct ether_hdr *eth_hdr;
> > + struct ipv4_hdr *ipv4_hdr;
> > + uint16_t l3proc_type;
> > + struct gro_tcp_rule tcp_rule;
> > +
> > + if (pkt == NULL)
> > + return -1;
> > + tcp_rule.max_packet_size = gro_tbl->max_packet_size;
> > + eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
> > + l3proc_type = rte_be_to_cpu_16(eth_hdr->ether_type);
> > + if (l3proc_type == ETHER_TYPE_IPv4) {
> > + ipv4_hdr = (struct ipv4_hdr *)(eth_hdr + 1);
> > + if (ipv4_hdr->next_proto_id == IPPROTO_TCP &&
> > + (gro_tbl->desired_gro_types & GRO_TCP_IPV4)) {
> > + return gro_tcp4_reassemble(pkt,
> > + gro_tbl->tbls[GRO_TCP_IPV4_INDEX],
> > + &tcp_rule);
> > + }
> > + }
> > return -1;
> > }
> > -uint16_t rte_gro_flush(struct rte_gro_tbl *gro_tbl __rte_unused,
> > - uint64_t desired_gro_types __rte_unused,
> > - uint16_t flush_num __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,
> > + uint16_t flush_num,
> > + struct rte_mbuf **out,
> > + const uint16_t max_nb_out)
> > {
>
> Ditto.
>
> > + 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],
> > + flush_num,
> > + 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 67bd90d..e26aa5b 100644
> > --- a/lib/librte_gro/rte_gro.h
> > +++ b/lib/librte_gro/rte_gro.h
> > @@ -35,7 +35,11 @@
> > /* maximum number of supported GRO types */
> > #define GRO_TYPE_MAX_NB 64
> > -#define GRO_TYPE_SUPPORT_NB 0 /**< current supported GRO num */
> > +#define GRO_TYPE_SUPPORT_NB 1 /**< supported GRO types number */
> > +
> > +/* TCP/IPv4 GRO flag */
> > +#define GRO_TCP_IPV4_INDEX 0
> > +#define GRO_TCP_IPV4 (1ULL << GRO_TCP_IPV4_INDEX)
> > /**
> > * GRO table structure. DPDK GRO uses GRO table to reassemble
> > @@ -139,9 +143,9 @@ void rte_gro_tbl_destroy(struct rte_gro_tbl *gro_tbl);
> > * @return
> > * the number of packets after GROed.
> > */
> > -uint16_t rte_gro_reassemble_burst(struct rte_mbuf **pkts __rte_unused,
> > - const uint16_t nb_pkts __rte_unused,
> > - const struct rte_gro_param param __rte_unused);
> > +uint16_t rte_gro_reassemble_burst(struct rte_mbuf **pkts,
> > + const uint16_t nb_pkts,
> > + const struct rte_gro_param param);
> > /**
> > * This is the main reassembly API used in heavyweight mode, which
> > @@ -164,8 +168,8 @@ uint16_t rte_gro_reassemble_burst(struct rte_mbuf
> > **pkts __rte_unused,
> > * if merge the packet successfully, return a positive value. If fail
> > * to merge, return zero. If errors happen, return a negative value.
> > */
> > -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);
> > /**
> > * This function flushed packets of desired GRO types from their
> > @@ -184,11 +188,11 @@ int rte_gro_reassemble(struct rte_mbuf *pkt
> > __rte_unused,
> > * @return
> > * the number of flushed packets. If no packets are flushed, return 0.
> > */
> > -uint16_t rte_gro_flush(struct rte_gro_tbl *gro_tbl __rte_unused,
> > - uint64_t desired_gro_types __rte_unused,
> > - uint16_t flush_num __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,
> > + uint16_t flush_num,
> > + struct rte_mbuf **out,
> > + const uint16_t max_nb_out);
> > /**
> > * This function flushes the timeout packets from reassembly tables of
> > @@ -206,8 +210,8 @@ uint16_t rte_gro_flush(struct rte_gro_tbl *gro_tbl
> > __rte_unused,
> > * @return
> > * the number of flushed packets. If no packets are flushed, 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);
> > +uint16_t 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);
>
> Do you have any cases to test this API? I don't see following example use
> this API. That means we are exposing an API that are never tested. I don't
> know if we can add some experimental flag on this API. Let's seek advice
> from others.
These flush APIs are used in heavyweight mode. But testpmd is not a good case
to use heavyweight mode. How do you think if we use some unit tests to test
them?
>
> > #endif
> > diff --git a/lib/librte_gro/rte_gro_tcp.c b/lib/librte_gro/rte_gro_tcp.c
> > new file mode 100644
> > index 0000000..86743cd
> > --- /dev/null
> > +++ b/lib/librte_gro/rte_gro_tcp.c
> > @@ -0,0 +1,527 @@
> > +/*-
> > + * BSD LICENSE
> > + *
> > + * Copyright(c) 2016-2017 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,
>
> Define it as "static". Similar to other functions.
>
> > + uint16_t max_flow_num,
> > + uint16_t max_item_per_flow)
> > +{
> > + size_t size;
> > + uint32_t entries_num;
> > + struct gro_tcp_tbl *tbl;
> > +
> > + max_flow_num = max_flow_num > GRO_TCP_TBL_MAX_FLOW_NUM ?
> > + GRO_TCP_TBL_MAX_FLOW_NUM : max_flow_num;
> > +
> > + 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 || max_flow_num == 0)
> > + return NULL;
> > +
> > + tbl = (struct gro_tcp_tbl *)rte_zmalloc_socket(
> > + __func__,
> > + sizeof(struct gro_tcp_tbl),
> > + RTE_CACHE_LINE_SIZE,
> > + socket_id);
> > +
> > + 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_flow) * max_flow_num;
> > + tbl->flows = (struct gro_tcp_flow *)rte_zmalloc_socket(
> > + __func__,
> > + size, RTE_CACHE_LINE_SIZE,
> > + socket_id);
> > + tbl->max_flow_num = max_flow_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)
> > + rte_free(tcp_tbl->items);
> > + if (tcp_tbl->flows)
> > + rte_free(tcp_tbl->flows);
> > + rte_free(tcp_tbl);
> > + }
> > +}
> > +
> > +/* update TCP header and IPv4 header checksum */
> > +static void
> > +gro_tcp4_cksum_update(struct rte_mbuf *pkt)
> > +{
> > + uint32_t len, offset, cksum;
> > + struct ether_hdr *eth_hdr;
> > + struct ipv4_hdr *ipv4_hdr;
> > + struct tcp_hdr *tcp_hdr;
> > + uint16_t ipv4_ihl, cksum_pld;
> > +
> > + if (pkt == NULL)
> > + return;
> > +
> > + len = pkt->pkt_len;
> > + eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
> > + ipv4_hdr = (struct ipv4_hdr *)(eth_hdr + 1);
> > + ipv4_ihl = IPv4_HDR_LEN(ipv4_hdr);
> > + tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + ipv4_ihl);
> > +
> > + offset = sizeof(struct ether_hdr) + ipv4_ihl;
> > + len -= offset;
> > +
> > + /* TCP cksum without IP pseudo header */
> > + ipv4_hdr->hdr_checksum = 0;
> > + tcp_hdr->cksum = 0;
> > + rte_raw_cksum_mbuf(pkt, offset, len, &cksum_pld);
> > +
> > + /* IP pseudo header cksum */
> > + cksum = cksum_pld;
> > + cksum += rte_ipv4_phdr_cksum(ipv4_hdr, 0);
> > +
> > + /* combine TCP checksum and IP pseudo header checksum */
> > + cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
> > + cksum = (~cksum) & 0xffff;
> > + cksum = (cksum == 0) ? 0xffff : cksum;
> > + tcp_hdr->cksum = cksum;
> > +
> > + /* update IP header cksum */
> > + ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> > +}
> > +
> > +void gro_tcp4_tbl_cksum_update(struct gro_tcp_tbl *tbl)
> > +{
> > + uint32_t i;
> > + uint32_t item_num = tbl->item_num;
> > +
> > + for (i = 0; i < tbl->max_item_num; i++) {
> > + if (tbl->items[i].is_valid) {
> > + item_num--;
> > + if (tbl->items[i].is_groed)
> > + gro_tcp4_cksum_update(tbl->items[i].pkt);
> > + }
> > + if (unlikely(item_num == 0))
> > + break;
> > + }
> > +}
> > +
> > +/**
> > + * merge two TCP/IPv4 packets without update header checksum.
> > + */
> > +static int
> > +merge_two_tcp4_packets(struct rte_mbuf *pkt_src,
> > + struct rte_mbuf *pkt,
> > + struct gro_tcp_rule *rule)
> > +{
> > + 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);
> > + 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);
> > +
> > + /* check reassembly rules */
> > + if (pkt_src->pkt_len + tcp_dl1 > rule->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;
> > +
> > + /* 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++;
> > + 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) {
> > + /* check if TCP option field equals */
> > + if (tcp_hl1 > sizeof(struct tcp_hdr)) {
> > + 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_ITEM_INDEX;
> > +}
> > +
> > +static uint16_t
> > +find_an_empty_flow(struct gro_tcp_tbl *tbl)
> > +{
> > + uint16_t i;
> > +
> > + for (i = 0; i < tbl->max_flow_num; i++)
> > + if (tbl->flows[i].is_valid == 0)
> > + return i;
> > + return INVALID_FLOW_INDEX;
> > +}
> > +
> > +int32_t
> > +gro_tcp4_reassemble(struct rte_mbuf *pkt,
> > + struct gro_tcp_tbl *tbl,
> > + struct gro_tcp_rule *rule)
> > +{
> > + struct ether_hdr *eth_hdr;
> > + struct ipv4_hdr *ipv4_hdr;
> > + struct tcp_hdr *tcp_hdr;
> > + uint16_t ipv4_ihl, tcp_hl, tcp_dl, tcp_cksum, ip_cksum;
> > +
> > + struct gro_tcp_flow_key key;
> > + uint64_t ol_flags;
> > + uint32_t cur_idx, prev_idx, item_idx;
> > + uint16_t i, flow_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);
> > +
> > + /* 1. check if the packet should be processed */
> > + if (ipv4_ihl < sizeof(struct ipv4_hdr))
> > + goto fail;
> > + if (ipv4_hdr->next_proto_id != IPPROTO_TCP)
> > + goto fail;
> > + if ((ipv4_hdr->fragment_offset &
> > + rte_cpu_to_be_16(IPV4_HDR_DF_MASK))
> > + == 0)
> > + 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;
> > +
> > + /**
> > + * 2. if HW rx checksum offload isn't enabled, recalculate the
> > + * checksum in SW. Then, check if the checksum is correct
> > + */
> > + ol_flags = pkt->ol_flags;
> > + if ((ol_flags & PKT_RX_IP_CKSUM_MASK) !=
> > + PKT_RX_IP_CKSUM_UNKNOWN) {
> > + if (ol_flags == PKT_RX_IP_CKSUM_BAD)
> > + goto fail;
> > + } else {
> > + ip_cksum = ipv4_hdr->hdr_checksum;
> > + ipv4_hdr->hdr_checksum = 0;
> > + ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> > + if (ipv4_hdr->hdr_checksum ^ ip_cksum)
> > + goto fail;
> > + }
> > +
> > + if ((ol_flags & PKT_RX_L4_CKSUM_MASK) !=
> > + PKT_RX_L4_CKSUM_UNKNOWN) {
> > + if (ol_flags == PKT_RX_L4_CKSUM_BAD)
> > + goto fail;
> > + } else {
> > + tcp_cksum = tcp_hdr->cksum;
> > + tcp_hdr->cksum = 0;
> > + tcp_hdr->cksum = rte_ipv4_udptcp_cksum
> > + (ipv4_hdr, tcp_hdr);
> > + if (tcp_hdr->cksum ^ tcp_cksum)
> > + goto fail;
> > + }
> > +
> > + /**
> > + * 3. search for a flow and traverse all packets in the flow
> > + * to find one to merge with the given packet.
> > + */
> > + 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);
> > + 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_flow_num; i++) {
> > + /* search all packets in a valid flow. */
> > + if (tbl->flows[i].is_valid &&
> > + (memcmp(&(tbl->flows[i].key), &key,
> > + sizeof(struct gro_tcp_flow_key))
> > + == 0)) {
> > + cur_idx = tbl->flows[i].start_index;
> > + prev_idx = cur_idx;
> > + while (cur_idx != INVALID_ITEM_INDEX) {
> > + if (check_seq_option(tbl->items[cur_idx].pkt,
> > + tcp_hdr,
> > + tcp_hl) > 0) {
> > + if (merge_two_tcp4_packets(
> > +
> > tbl->items[cur_idx].pkt,
> > + pkt,
> > + rule) > 0) {
> > + /* successfully merge two
> > packets */
> > + tbl->items[cur_idx].is_groed =
> > 1;
> > + return 1;
> > + }
> > + /**
> > + * fail to merge two packets since
> > + * break the rules, add the packet
> > + * into the flow.
> > + */
> > + goto insert_to_existed_flow;
> > + } else {
> > + prev_idx = cur_idx;
> > + cur_idx =
> > tbl->items[cur_idx].next_pkt_idx;
> > + }
> > + }
> > + /**
> > + * fail to merge the given packet into an existed flow,
> > + * add it into the flow.
> > + */
> > +insert_to_existed_flow:
> > + item_idx = find_an_empty_item(tbl);
> > + /* the item number is beyond the maximum value */
> > + if (item_idx == INVALID_ITEM_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_ITEM_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 is a new flow. Therefore,
> > + * insert a new flow.
> > + */
> > + item_idx = find_an_empty_item(tbl);
> > + flow_idx = find_an_empty_flow(tbl);
> > + /**
> > + * if the flow or item number are beyond the maximum values,
> > + * the inputted packet won't be processed.
> > + */
> > + if (item_idx == INVALID_ITEM_INDEX ||
> > + flow_idx == INVALID_FLOW_INDEX)
> > + return -1;
> > + tbl->items[item_idx].pkt = pkt;
> > + tbl->items[item_idx].next_pkt_idx = INVALID_ITEM_INDEX;
> > + tbl->items[item_idx].is_groed = 0;
> > + tbl->items[item_idx].is_valid = 1;
> > + tbl->items[item_idx].start_time = rte_rdtsc();
> > + tbl->item_num++;
> > +
> > + memcpy(&(tbl->flows[flow_idx].key),
> > + &key, sizeof(struct gro_tcp_flow_key));
> > + tbl->flows[flow_idx].start_index = item_idx;
> > + tbl->flows[flow_idx].is_valid = 1;
> > + tbl->flow_num++;
> > +
> > + return 0;
> > +fail:
> > + return -1;
> > +}
> > +
> > +uint16_t gro_tcp_tbl_flush(struct gro_tcp_tbl *tbl,
> > + uint16_t flush_num,
> > + struct rte_mbuf **out,
> > + const uint16_t nb_out)
> > +{
> > + uint16_t num, k;
> > + uint16_t i;
> > + uint32_t j;
> > +
> > + k = 0;
> > + num = tbl->item_num > flush_num ? flush_num : tbl->item_num;
> > + num = num > nb_out ? nb_out : num;
> > + if (unlikely(num == 0))
> > + return 0;
> > +
> > + for (i = 0; i < tbl->max_flow_num; i++) {
> > + if (tbl->flows[i].is_valid) {
> > + j = tbl->flows[i].start_index;
> > + while (j != INVALID_ITEM_INDEX) {
> > + /* update checksum for GROed packet */
> > + if (tbl->items[j].is_groed)
> > +
> > gro_tcp4_cksum_update(tbl->items[j].pkt);
> > +
> > + out[k++] = tbl->items[j].pkt;
> > + tbl->items[j].is_valid = 0;
> > + tbl->item_num--;
> > + j = tbl->items[j].next_pkt_idx;
> > +
> > + if (k == num) {
> > + /* delete the flow */
> > + if (j == INVALID_ITEM_INDEX) {
> > + tbl->flows[i].is_valid = 0;
> > + tbl->flow_num--;
> > + } else
> > + /* update flow information */
> > + tbl->flows[i].start_index = j;
> > + goto end;
> > + }
> > + }
> > + /* delete the flow, as all of its packets are flushed */
> > + tbl->flows[i].is_valid = 0;
> > + tbl->flow_num--;
> > + }
> > + if (tbl->flow_num == 0)
> > + goto end;
> > + }
> > +end:
> > + 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;
> > + uint16_t i;
> > + uint32_t j;
> > + uint64_t current_time;
> > +
> > + if (nb_out == 0)
> > + return 0;
> > + k = 0;
> > + current_time = rte_rdtsc();
> > +
> > + for (i = 0; i < tbl->max_flow_num; i++) {
> > + if (tbl->flows[i].is_valid) {
> > + j = tbl->flows[i].start_index;
> > + while (j != INVALID_ITEM_INDEX) {
> > + if (current_time - tbl->items[j].start_time >=
> > + timeout_cycles) {
> > + /* update checksum for GROed packet */
> > + if (tbl->items[j].is_groed)
> > +
> > gro_tcp4_cksum_update(tbl->items[j].pkt);
> > +
> > + 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_ITEM_INDEX) {
> > + /* delete the flow */
> > + tbl->flows[i].is_valid = 0;
> > + tbl->flow_num--;
> > + goto end;
> > + } else if (k == nb_out &&
> > + j !=
> > INVALID_ITEM_INDEX) {
> > + tbl->flows[i].start_index = j;
> > + goto end;
> > + }
> > + }
> > + }
> > + /* delete the flow, as all of its packets are flushed */
> > + tbl->flows[i].is_valid = 0;
> > + tbl->flow_num--;
> > + }
> > + if (tbl->flow_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..551efc4
> > --- /dev/null
> > +++ b/lib/librte_gro/rte_gro_tcp.h
> > @@ -0,0 +1,210 @@
> > +/*-
> > + * BSD LICENSE
> > + *
> > + * Copyright(c) 2016-2017 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 IPV4_HDR_DF_SHIFT 14
> > +#define IPV4_HDR_DF_MASK (1 << IPV4_HDR_DF_SHIFT)
> > +
> > +#define INVALID_FLOW_INDEX 0xffffU
> > +#define INVALID_ITEM_INDEX 0xffffffffUL
> > +
> > +#define GRO_TCP_TBL_MAX_FLOW_NUM (UINT16_MAX - 1)
> > +#define GRO_TCP_TBL_MAX_ITEM_NUM (UINT32_MAX - 1)
> > +
> > +/* criteria of mergeing packets */
> > +struct gro_tcp_flow_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_flow {
> > + struct gro_tcp_flow_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 */
> > +};
> > +
> > +/**
> > + * 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_flow *flows; /**< flow array */
> > + uint32_t item_num; /**< current item number */
> > + uint16_t flow_num; /**< current flow num */
> > + uint32_t max_item_num; /**< item array size */
> > + uint16_t max_flow_num; /**< flow array size */
> > +};
> > +
> > +/* rules to reassemble TCP packets, which are decided by applications */
> > +struct gro_tcp_rule {
> > + /* the maximum packet length after merged */
> > + uint32_t max_packet_size;
> > +};
>
> Are there any other rules? If not, I prefer to use max_packet_size directly.
If we agree to use a flag to indicate if check checksum, this structure should
be used to keep this flag.
>
> > +
> > +/**
> > + * This function is to update TCP and IPv4 header checksums
> > + * for merged packets in the TCP reassembly table.
> > + */
> > +void gro_tcp4_tbl_cksum_update(struct gro_tcp_tbl *tbl);
> > +
> > +/**
> > + * 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. Note that this function won't
> > + * re-calculate IPv4 and TCP checksums.
> > + *
> > + * If the packet doesn't have data, or with wrong checksums, or is
> > + * fragmented etc., errors happen and gro_tcp4_reassemble returns
> > + * immediately. If no errors happen, the packet is either merged, or
> > + * inserted into the reassembly table.
> > + *
> > + * If applications want to get packets in the reassembly table, they
> > + * need to manually flush the packets.
> > + *
> > + * @param pkt
> > + * packet to reassemble.
> > + * @param tbl
> > + * a pointer that points to a TCP reassembly table.
> > + * @param rule
> > + * TCP reassembly criteria defined by applications.
> > + * @return
> > + * if the inputted packet is merged successfully, return an positive
> > + * value. If the packet hasn't be merged with any packets in the TCP
> > + * reassembly table. If errors happen, return a negative value and the
> > + * packet won't be inserted into the reassemble table.
> > + */
> > +int32_t
> > +gro_tcp4_reassemble(struct rte_mbuf *pkt,
> > + struct gro_tcp_tbl *tbl,
> > + struct gro_tcp_rule *rule);
> > +
> > +/**
> > + * This function flushes the packets in a TCP reassembly table to
> > + * applications. Before returning the packets, it will update TCP and
> > + * IPv4 header checksums.
> > + *
> > + * @param tbl
> > + * a pointer that points to a TCP GRO table.
> > + * @param flush_num
> > + * the number of packets that applications want to flush.
> > + * @param out
> > + * pointer array which is used to keep flushed packets.
> > + * @param nb_out
> > + * the maximum element number of out.
> > + * @return
> > + * the number of packets that are flushed finally.
> > + */
> > +uint16_t
> > +gro_tcp_tbl_flush(struct gro_tcp_tbl *tbl,
> > + uint16_t flush_num,
> > + struct rte_mbuf **out,
> > + const uint16_t nb_out);
> > +
> > +/**
> > + * This function flushes timeout packets in a TCP reassembly table to
> > + * applications. Before returning the packets, it updates TCP and IPv4
> > + * header checksums.
> > + *
> > + * @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 maximum element number of out.
> > + * @return
> > + * It returns the number of packets that are flushed finally.
> > + */
> > +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
