cbd4e90781
Simplification of previous fix. Also fixes the case when new data should be sent while a keepalive is not yet acked.
630 lines
17 KiB
C
630 lines
17 KiB
C
/****************************************************************************
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* net/tcp/tcp_send.c
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*
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* Copyright (C) 2007-2010, 2012, 2015, 2018-2019 Gregory Nutt. All rights
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* reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Adapted for NuttX from logic in uIP which also has a BSD-like license:
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*
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* Original author Adam Dunkels <adam@dunkels.com>
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* Copyright () 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 <nuttx/config.h>
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#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
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#include <stdint.h>
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#include <string.h>
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#include <debug.h>
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#include <nuttx/net/netconfig.h>
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#include <nuttx/net/netdev.h>
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#include <nuttx/net/netstats.h>
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#include <nuttx/net/ip.h>
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#include <nuttx/net/tcp.h>
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#include "devif/devif.h"
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#include "inet/inet.h"
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#include "tcp/tcp.h"
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#include "utils/utils.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define IPv4BUF ((struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
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#define IPv6BUF ((struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
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#define TCPIPv4BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN])
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#define TCPIPv6BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: tcp_header
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*
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* Description:
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* Get the length of the IP header
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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*
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* Returned Value:
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* The length of the IP header (IPv4_HDRLEN or IPv6_HDRLEN)
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*
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****************************************************************************/
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static inline FAR struct tcp_hdr_s *tcp_header(FAR struct net_driver_s *dev)
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{
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#ifdef CONFIG_NET_IPv6
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#ifdef CONFIG_NET_IPv4
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if (IFF_IS_IPv6(dev->d_flags))
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#endif
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{
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return TCPIPv6BUF;
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}
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#endif /* CONFIG_NET_IPv6 */
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#ifdef CONFIG_NET_IPv4
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#ifdef CONFIG_NET_IPv6
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else
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#endif
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{
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return TCPIPv4BUF;
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}
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#endif /* CONFIG_NET_IPv4 */
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}
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/****************************************************************************
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* Name: tcp_sendcomplete, tcp_ipv4_sendcomplete, and tcp_ipv6_sendcomplete
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*
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* Description:
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* Complete the final portions of the send operation. This function sets
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* up IP header and computes the TCP checksum
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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#ifdef CONFIG_NET_IPv4
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static inline void tcp_ipv4_sendcomplete(FAR struct net_driver_s *dev,
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FAR struct tcp_hdr_s *tcp,
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FAR struct ipv4_hdr_s *ipv4)
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{
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/* Set up some IP header fields that are needed for TCP checksum
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* calculation.
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*/
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ipv4->proto = IP_PROTO_TCP;
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ipv4->ttl = IP_TTL;
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ipv4->vhl = 0x45;
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/* At this point the TCP header holds the size of the payload, the
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* TCP header, and the IP header.
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*/
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ipv4->len[0] = (dev->d_len >> 8);
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ipv4->len[1] = (dev->d_len & 0xff);
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/* Calculate TCP checksum. */
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tcp->urgp[0] = 0;
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tcp->urgp[1] = 0;
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tcp->tcpchksum = 0;
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tcp->tcpchksum = ~tcp_ipv4_chksum(dev);
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/* Finish initializing the IP header and calculate the IP checksum */
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ipv4->vhl = 0x45;
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ipv4->tos = 0;
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ipv4->ipoffset[0] = 0;
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ipv4->ipoffset[1] = 0;
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++g_ipid;
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ipv4->ipid[0] = g_ipid >> 8;
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ipv4->ipid[1] = g_ipid & 0xff;
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/* Calculate IP checksum. */
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ipv4->ipchksum = 0;
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ipv4->ipchksum = ~ipv4_chksum(dev);
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ninfo("IPv4 length: %d\n", ((int)ipv4->len[0] << 8) + ipv4->len[1]);
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#ifdef CONFIG_NET_STATISTICS
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g_netstats.ipv4.sent++;
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#endif
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}
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#endif /* CONFIG_NET_IPv4 */
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/****************************************************************************
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* Name: tcp_ipv6_sendcomplete
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*
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* Description:
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* Complete the final portions of the send operation. This function sets
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* up IP header and computes the TCP checksum
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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#ifdef CONFIG_NET_IPv6
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static inline void tcp_ipv6_sendcomplete(FAR struct net_driver_s *dev,
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FAR struct tcp_hdr_s *tcp,
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FAR struct ipv6_hdr_s *ipv6)
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{
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uint16_t iplen;
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/* Set up some IP header fields that are needed for TCP checksum
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* calculation.
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*/
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ipv6->proto = IP_PROTO_TCP;
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ipv6->ttl = IP_TTL;
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/* At this point the TCP header holds the size of the payload, the
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* TCP header, and the IP header. For IPv6, the IP length field does
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* not include the size of IPv6 IP header length.
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*/
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iplen = dev->d_len - IPv6_HDRLEN;
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ipv6->len[0] = (iplen >> 8);
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ipv6->len[1] = (iplen & 0xff);
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/* Calculate TCP checksum. */
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tcp->urgp[0] = 0;
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tcp->urgp[1] = 0;
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tcp->tcpchksum = 0;
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tcp->tcpchksum = ~tcp_ipv6_chksum(dev);
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/* Finish initializing the IP header (no IPv6 checksum) */
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ipv6->vtc = 0x60;
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ipv6->tcf = 0x00;
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ipv6->flow = 0x00;
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ninfo("IPv6 length: %d\n", ((int)ipv6->len[0] << 8) + ipv6->len[1]);
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#ifdef CONFIG_NET_STATISTICS
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g_netstats.ipv6.sent++;
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#endif
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}
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#endif /* CONFIG_NET_IPv6 */
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/****************************************************************************
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* Name: tcp_sendcomplete
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*
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* Description:
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* Complete the final portions of the send operation. This function sets
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* up IP header and computes the TCP checksum
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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static void tcp_sendcomplete(FAR struct net_driver_s *dev,
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FAR struct tcp_hdr_s *tcp)
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{
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#ifdef CONFIG_NET_IPv6
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#ifdef CONFIG_NET_IPv4
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if (IFF_IS_IPv6(dev->d_flags))
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#endif
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{
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tcp_ipv6_sendcomplete(dev, tcp, IPv6BUF);
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}
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#endif /* CONFIG_NET_IPv6 */
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#ifdef CONFIG_NET_IPv4
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#ifdef CONFIG_NET_IPv6
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else
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#endif
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{
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tcp_ipv4_sendcomplete(dev, tcp, IPv4BUF);
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}
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#endif /* CONFIG_NET_IPv4 */
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ninfo("Outgoing TCP packet length: %d bytes\n", dev->d_len);
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#ifdef CONFIG_NET_STATISTICS
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g_netstats.tcp.sent++;
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#endif
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}
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/****************************************************************************
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* Name: tcp_sendcommon
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*
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* Description:
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* We're done with the input processing. We are now ready to send a reply
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* Our job is to fill in all the fields of the TCP and IP headers before
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* calculating the checksum and finally send the packet.
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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* conn - The TCP connection structure holding connection information
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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static void tcp_sendcommon(FAR struct net_driver_s *dev,
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FAR struct tcp_conn_s *conn,
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FAR struct tcp_hdr_s *tcp)
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{
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/* Copy the IP address into the IPv6 header */
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#ifdef CONFIG_NET_IPv6
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#ifdef CONFIG_NET_IPv4
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if (IFF_IS_IPv6(dev->d_flags))
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#endif
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{
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FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
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net_ipv6addr_hdrcopy(ipv6->srcipaddr, dev->d_ipv6addr);
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net_ipv6addr_hdrcopy(ipv6->destipaddr, conn->u.ipv6.raddr);
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}
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#endif /* CONFIG_NET_IPv6 */
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#ifdef CONFIG_NET_IPv4
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#ifdef CONFIG_NET_IPv6
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else
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#endif
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{
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FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
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net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
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net_ipv4addr_hdrcopy(ipv4->destipaddr, &conn->u.ipv4.raddr);
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}
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#endif /* CONFIG_NET_IPv4 */
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/* Set TCP sequence numbers and port numbers */
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memcpy(tcp->ackno, conn->rcvseq, 4);
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memcpy(tcp->seqno, conn->sndseq, 4);
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tcp->srcport = conn->lport;
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tcp->destport = conn->rport;
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/* Set the TCP window */
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if (conn->tcpstateflags & TCP_STOPPED)
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{
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/* If the connection has issued TCP_STOPPED, we advertise a zero
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* window so that the remote host will stop sending data.
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*/
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tcp->wnd[0] = 0;
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tcp->wnd[1] = 0;
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}
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else
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{
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/* Update the TCP received window based on I/O buffer availability */
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uint16_t recvwndo = tcp_get_recvwindow(dev);
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/* Set the TCP Window */
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tcp->wnd[0] = recvwndo >> 8;
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tcp->wnd[1] = recvwndo & 0xff;
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}
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/* Finish the IP portion of the message and calculate checksums */
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tcp_sendcomplete(dev, tcp);
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: tcp_send
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*
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* Description:
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* Setup to send a TCP packet
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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* conn - The TCP connection structure holding connection information
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* flags - flags to apply to the TCP header
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* len - length of the message (includes the length of the IP and TCP
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* headers)
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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void tcp_send(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
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uint16_t flags, uint16_t len)
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{
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FAR struct tcp_hdr_s *tcp = tcp_header(dev);
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tcp->flags = flags;
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dev->d_len = len;
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tcp->tcpoffset = (TCP_HDRLEN / 4) << 4;
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tcp_sendcommon(dev, conn, tcp);
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}
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/****************************************************************************
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* Name: tcp_reset
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*
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* Description:
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* Send a TCP reset (no-data) message
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*
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* Input Parameters:
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* dev - The device driver structure to use in the send operation
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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* Called with the network locked.
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*
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****************************************************************************/
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void tcp_reset(FAR struct net_driver_s *dev)
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{
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FAR struct tcp_hdr_s *tcp = tcp_header(dev);
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uint32_t ackno;
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uint16_t tmp16;
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uint16_t acklen = 0;
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uint8_t seqbyte;
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#ifdef CONFIG_NET_STATISTICS
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g_netstats.tcp.rst++;
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#endif
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/* TCP setup */
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if ((tcp->flags & TCP_SYN) != 0 || (tcp->flags & TCP_FIN) != 0)
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{
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acklen++;
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}
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#ifdef CONFIG_NET_IPv6
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#ifdef CONFIG_NET_IPv4
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if (IFF_IS_IPv6(dev->d_flags))
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#endif
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{
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FAR struct ipv6_hdr_s *ip = IPv6BUF;
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acklen += (ip->len[0] << 8 | ip->len[1]);
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}
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#endif /* CONFIG_NET_IPv6 */
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#ifdef CONFIG_NET_IPv4
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#ifdef CONFIG_NET_IPv6
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else
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#endif
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{
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FAR struct ipv4_hdr_s *ip = IPv4BUF;
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acklen += (ip->len[0] << 8) + ip->len[1] - (ip->vhl & 0x0f) * 4;
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}
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#endif /* CONFIG_NET_IPv4 */
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acklen -= (tcp->tcpoffset >> 4) << 2;
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tcp->flags = TCP_RST | TCP_ACK;
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tcp->tcpoffset = 5 << 4;
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/* Flip the seqno and ackno fields in the TCP header. */
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seqbyte = tcp->seqno[3];
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tcp->seqno[3] = tcp->ackno[3];
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tcp->ackno[3] = seqbyte;
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seqbyte = tcp->seqno[2];
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tcp->seqno[2] = tcp->ackno[2];
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tcp->ackno[2] = seqbyte;
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seqbyte = tcp->seqno[1];
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tcp->seqno[1] = tcp->ackno[1];
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tcp->ackno[1] = seqbyte;
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seqbyte = tcp->seqno[0];
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tcp->seqno[0] = tcp->ackno[0];
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tcp->ackno[0] = seqbyte;
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/* We also have to increase the sequence number we are
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* acknowledging. If the least significant byte overflowed, we need
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* to propagate the carry to the other bytes as well.
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*/
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ackno = tcp_addsequence(tcp->ackno, acklen);
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tcp_setsequence(tcp->ackno, ackno);
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/* Swap port numbers. */
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tmp16 = tcp->srcport;
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tcp->srcport = tcp->destport;
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tcp->destport = tmp16;
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/* Set the packet length and swap IP addresses. */
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#ifdef CONFIG_NET_IPv6
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#ifdef CONFIG_NET_IPv4
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if (IFF_IS_IPv6(dev->d_flags))
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#endif
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{
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FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
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/* Set the packet length to the size of the IPv6 + TCP headers */
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dev->d_len = IPv6TCP_HDRLEN;
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/* Swap IPv6 addresses */
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net_ipv6addr_hdrcopy(ipv6->destipaddr, ipv6->srcipaddr);
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net_ipv6addr_hdrcopy(ipv6->srcipaddr, dev->d_ipv6addr);
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}
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#endif /* CONFIG_NET_IPv6 */
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#ifdef CONFIG_NET_IPv4
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#ifdef CONFIG_NET_IPv6
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else
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#endif
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{
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FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
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/* Set the packet length to the size of the IPv4 + TCP headers */
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dev->d_len = IPv4TCP_HDRLEN;
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/* Swap IPv4 addresses */
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net_ipv4addr_hdrcopy(ipv4->destipaddr, ipv4->srcipaddr);
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net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
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}
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#endif /* CONFIG_NET_IPv4 */
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/* And send out the RST packet */
|
|
|
|
tcp_sendcomplete(dev, tcp);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: tcp_synack
|
|
*
|
|
* Description:
|
|
* Send the SYN, ACK, or SYNACK response.
|
|
*
|
|
* - SYN and SYNACK are sent only from the TCP state machine.
|
|
* - ACK may be sent alone only if delayed ACKs are enabled and the ACK
|
|
* delay timeout occurs.
|
|
*
|
|
* Input Parameters:
|
|
* dev - The device driver structure to use in the send operation
|
|
* conn - The TCP connection structure holding connection information
|
|
* ack - The ACK response to send
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
* Called with the network locked.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void tcp_synack(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
|
|
uint8_t ack)
|
|
{
|
|
struct tcp_hdr_s *tcp;
|
|
uint16_t tcp_mss;
|
|
|
|
/* Get values that vary with the underlying IP domain */
|
|
|
|
#ifdef CONFIG_NET_IPv6
|
|
#ifdef CONFIG_NET_IPv4
|
|
if (IFF_IS_IPv6(dev->d_flags))
|
|
#endif
|
|
{
|
|
/* Get the MSS value and offset TCP header address for this packet */
|
|
|
|
tcp = TCPIPv6BUF;
|
|
tcp_mss = TCP_IPv6_MSS(dev);
|
|
|
|
/* Set the packet length for the TCP Maximum Segment Size */
|
|
|
|
dev->d_len = IPv6TCP_HDRLEN + TCP_OPT_MSS_LEN;
|
|
}
|
|
#endif /* CONFIG_NET_IPv6 */
|
|
|
|
#ifdef CONFIG_NET_IPv4
|
|
#ifdef CONFIG_NET_IPv6
|
|
else
|
|
#endif
|
|
{
|
|
/* Get the MSS value and offset TCP header address for this packet */
|
|
|
|
tcp = TCPIPv4BUF;
|
|
tcp_mss = TCP_IPv4_MSS(dev);
|
|
|
|
/* Set the packet length for the TCP Maximum Segment Size */
|
|
|
|
dev->d_len = IPv4TCP_HDRLEN + TCP_OPT_MSS_LEN;
|
|
}
|
|
#endif /* CONFIG_NET_IPv4 */
|
|
|
|
/* Save the ACK bits */
|
|
|
|
tcp->flags = ack;
|
|
|
|
/* We send out the TCP Maximum Segment Size option with our ACK. */
|
|
|
|
tcp->optdata[0] = TCP_OPT_MSS;
|
|
tcp->optdata[1] = TCP_OPT_MSS_LEN;
|
|
tcp->optdata[2] = tcp_mss >> 8;
|
|
tcp->optdata[3] = tcp_mss & 0xff;
|
|
tcp->tcpoffset = ((TCP_HDRLEN + TCP_OPT_MSS_LEN) / 4) << 4;
|
|
|
|
/* Complete the common portions of the TCP message */
|
|
|
|
tcp_sendcommon(dev, conn, tcp);
|
|
}
|
|
|
|
#endif /* CONFIG_NET && CONFIG_NET_TCP */
|