1. Add new config CONFIG_NET_LL_GUARDSIZE to isolation of l2 stack,
which will benefit l3(IP) layer for multi-MAC(l2) implementation,
especially in some NICs such as celluler net driver.
new configuration options: CONFIG_NET_LL_GUARDSIZE
CONFIG_NET_LL_GUARDSIZE will reserved l2 buffer header size of
network buffer to isolate the L2/L3 (MAC/IP) data on network layer,
which will be beneficial to L3 network layer protocol transparent
transmission and forwarding
------------------------------------------------------------
Layout of frist iob entry:
iob_data (aligned by CONFIG_IOB_ALIGNMENT)
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| io_offset(CONFIG_NET_LL_GUARDSIZE)
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-------------------------------------------------
iob | Reserved | io_len |
-------------------------------------------------
-------------------------------------------------------------
Layout of different NICs implementation:
iob_data (aligned by CONFIG_IOB_ALIGNMENT)
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| io_offset(CONFIG_NET_LL_GUARDSIZE)
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-------------------------------------------------
Ethernet | Reserved | ETH_HDRLEN | io_len |
---------------------------------|---------------
8021Q | Reserved | ETH_8021Q_HDRLEN | io_len |
---------------------------------|---------------
ipforward | Reserved | io_len |
-------------------------------------------------
--------------------------------------------------------------------
2. Support iob offload to l2 driver to avoid unnecessary memory copy
Support send/receive iob vectors directly between the NICs and l3/l4
stack to avoid unnecessary memory copies, especially on hardware that
supports Scatter/gather, which can greatly improve performance.
new interface to support iob offload:
------------------------------------------
| IOB version | original |
|----------------------------------------|
| devif_iob_poll() | devif_poll() |
| ... | ... |
------------------------------------------
--------------------------------------------------------------------
1> NIC hardware support Scatter/gather transfer
TX:
tcp_poll()/udp_poll()/pkt_poll()/...(l3|l4)
/ \
/ \
devif_poll_[l3|l4]_connections() devif_iob_send() (nocopy:udp/icmp/...)
/ \ (copy:tcp)
/ \
devif_iob_poll("NIC"_txpoll) callback() // "NIC"_txpoll
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dev->d_iob: |
--------------- ---------------
io_data iob1 | | | iob3 | | |
\ --------------- ---------------
--------------- | --------------- |
iob0 | | | | iob2 | | | |
--------------- | --------------- |
\ | / /
\ | / /
----------------------------------------------
NICs io vector | | | | | | | | | |
----------------------------------------------
RX:
[tcp|udp|icmp|...]ipv[4|6]_data_handler()(iob_concat/append to readahead)
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[tcp|udp|icmp|...]_ipv[4|6]_in()/...
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pkt/ipv[4/6]_input()/...
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NICs io vector receive(iov_base to each iobs)
--------------------------------------------------------------------
2> CONFIG_IOB_BUFSIZE is greater than MTU:
TX:
"(CONFIG_IOB_BUFSIZE) > (MAX_NETDEV_PKTSIZE + CONFIG_NET_GUARDSIZE + CONFIG_NET_LL_GUARDSIZE)"
tcp_poll()/udp_poll()/pkt_poll()/...(l3|l4)
/ \
/ \
devif_poll_[l3|l4]_connections() devif_iob_send() (nocopy:udp/icmp/...)
/ \ (copy:tcp)
/ \
devif_iob_poll("NIC"_txpoll) callback() // "NIC"_txpoll
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"NIC"_send()
(dev->d_iob->io_data[CONFIG_NET_LL_GUARDSIZE - NET_LL_HDRLEN(dev)])
RX:
[tcp|udp|icmp|...]ipv[4|6]_data_handler()(iob_concat/append to readahead)
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[tcp|udp|icmp|...]_ipv[4|6]_in()/...
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pkt/ipv[4/6]_input()/...
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NICs io vector receive(iov_base to io_data)
--------------------------------------------------------------------
3> Compatible with all old flat buffer NICs
TX:
tcp_poll()/udp_poll()/pkt_poll()/...(l3|l4)
/ \
/ \
devif_poll_[l3|l4]_connections() devif_iob_send() (nocopy:udp/icmp/...)
/ \ (copy:tcp)
/ \
devif_iob_poll(devif_poll_callback()) devif_poll_callback() /* new interface, gather iobs to flat buffer */
/ \
/ \
devif_poll("NIC"_txpoll) "NIC"_send()(dev->d_buf)
RX:
[tcp|udp|icmp|...]ipv[4|6]_data_handler()(iob_concat/append to readahead)
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[tcp|udp|icmp|...]_ipv[4|6]_in()/...
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netdev_input() /* new interface, Scatter/gather flat/iob buffer */
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pkt/ipv[4|6]_input()/...
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NICs io vector receive(Orignal flat buffer)
3. Iperf passthrough on NuttX simulator:
-------------------------------------------------
| Protocol | Server | Client | |
|-----------------------------------------------|
| TCP | 813 | 834 | Mbits/sec |
| TCP(Offload) | 1720 | 1100 | Mbits/sec |
| UDP | 22 | 757 | Mbits/sec |
| UDP(Offload) | 25 | 1250 | Mbits/sec |
-------------------------------------------------
Signed-off-by: chao an <anchao@xiaomi.com>
87 lines
3.2 KiB
C
87 lines
3.2 KiB
C
/****************************************************************************
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* net/devif/devif_send.c
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*
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* Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Based in part on uIP which also has a BSD stylie license:
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*
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* Author: Adam Dunkels <adam@dunkels.com>
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* Copyright (c) 2001-2003, Adam Dunkels.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <string.h>
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#include <assert.h>
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#include <debug.h>
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#include <nuttx/net/netdev.h>
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#include "devif/devif.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: devif_send
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*
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* Description:
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* Called from socket logic in response to a xmit or poll request from the
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* the network interface driver.
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*
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* Assumptions:
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* The network is locked.
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*
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****************************************************************************/
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void devif_send(FAR struct net_driver_s *dev, FAR const void *buf,
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int len, unsigned int offset)
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{
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unsigned int limit = NETDEV_PKTSIZE(dev) -
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CONFIG_NET_LL_GUARDSIZE - offset;
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if (dev == NULL || len == 0 || len > limit)
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{
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nerr("ERROR: devif_send fail: %p, sndlen: %u, pktlen: %u\n",
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dev, len, limit);
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return;
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}
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iob_update_pktlen(dev->d_iob, offset);
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/* Copy in iob to target device buffer */
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dev->d_sndlen = iob_copyin(dev->d_iob, buf, len, offset, false) == len ?
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len : 0;
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}
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