incubator-nuttx/net/uip/uip-tcpsend.c

359 lines
10 KiB
C

/****************************************************************************
* net/uip/uip-tcpsend.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Adapted for NuttX from logic in uIP which also has a BSD-like license:
*
* Original author Adam Dunkels <adam@dunkels.com>
* Copyright () 2001-2003, Adam Dunkels.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
#include <sys/types.h>
#include <string.h>
#include <debug.h>
#include <net/uip/uipopt.h>
#include <net/uip/uip.h>
#include <net/uip/uip-arch.h>
#include "uip-internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
#define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: uip_tcpsendcomplete
*
* Description:
* Complete the final portions of the send operation. This function sets
* up IP header and computes the TCP checksum
*
* Parameters:
* dev - The device driver structure to use in the send operation
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
static void uip_tcpsendcomplete(struct uip_driver_s *dev)
{
BUF->ttl = UIP_TTL;
#ifdef CONFIG_NET_IPv6
/* For IPv6, the IP length field does not include the IPv6 IP header
* length.
*/
BUF->len[0] = ((dev->d_len - UIP_IPH_LEN) >> 8);
BUF->len[1] = ((dev->d_len - UIP_IPH_LEN) & 0xff);
#else /* CONFIG_NET_IPv6 */
BUF->len[0] = (dev->d_len >> 8);
BUF->len[1] = (dev->d_len & 0xff);
#endif /* CONFIG_NET_IPv6 */
BUF->urgp[0] = BUF->urgp[1] = 0;
/* Calculate TCP checksum. */
BUF->tcpchksum = 0;
BUF->tcpchksum = ~(uip_tcpchksum(dev));
#ifdef CONFIG_NET_IPv6
BUF->vtc = 0x60;
BUF->tcf = 0x00;
BUF->flow = 0x00;
#else /* CONFIG_NET_IPv6 */
BUF->vhl = 0x45;
BUF->tos = 0;
BUF->ipoffset[0] = 0;
BUF->ipoffset[1] = 0;
++g_ipid;
BUF->ipid[0] = g_ipid >> 8;
BUF->ipid[1] = g_ipid & 0xff;
/* Calculate IP checksum. */
BUF->ipchksum = 0;
BUF->ipchksum = ~(uip_ipchksum(dev));
#endif /* CONFIG_NET_IPv6 */
nvdbg("Outgoing TCP packet length: %d (%d)\n",
dev->d_len, (BUF->len[0] << 8) | BUF->len[1]);
#ifdef CONFIG_NET_STATISTICS
uip_stat.tcp.sent++;
uip_stat.ip.sent++;
#endif
}
/****************************************************************************
* Name: uip_tcpsendcommon
*
* Description:
* We're done with the input processing. We are now ready to send a reply
* Our job is to fill in all the fields of the TCP and IP headers before
* calculating the checksum and finally send the packet.
*
* Parameters:
* dev - The device driver structure to use in the send operation
* conn - The TCP connection structure holding connection information
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
static void uip_tcpsendcommon(struct uip_driver_s *dev, struct uip_conn *conn)
{
memcpy(BUF->ackno, conn->rcv_nxt, 4);
memcpy(BUF->seqno, conn->snd_nxt, 4);
BUF->proto = UIP_PROTO_TCP;
BUF->srcport = conn->lport;
BUF->destport = conn->rport;
uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr);
uiphdr_ipaddr_copy(BUF->destipaddr, &conn->ripaddr);
if (conn->tcpstateflags & UIP_STOPPED)
{
/* If the connection has issued uip_stop(), we advertise a zero
* window so that the remote host will stop sending data.
*/
BUF->wnd[0] = 0;
BUF->wnd[1] = 0;
}
else
{
BUF->wnd[0] = ((CONFIG_NET_RECEIVE_WINDOW) >> 8);
BUF->wnd[1] = ((CONFIG_NET_RECEIVE_WINDOW) & 0xff);
}
/* Finish the IP portion of the message, calculate checksums and send
* the message.
*/
uip_tcpsendcomplete(dev);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: uip_tcpsend
*
* Description:
* Setup to send a TCP packet
*
* Parameters:
* dev - The device driver structure to use in the send operation
* conn - The TCP connection structure holding connection information
* flags - flags to apply to the TCP header
* len - length of the message
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
void uip_tcpsend(struct uip_driver_s *dev, struct uip_conn *conn, uint16 flags, uint16 len)
{
BUF->flags = flags;
dev->d_len = len;
BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
uip_tcpsendcommon(dev, conn);
}
/****************************************************************************
* Name: uip_tcpreset
*
* Description:
* Send a TCP reset (no-data) message
*
* Parameters:
* dev - The device driver structure to use in the send operation
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
void uip_tcpreset(struct uip_driver_s *dev)
{
uint16 tmp16;
uint8 seqbyte;
#ifdef CONFIG_NET_STATISTICS
uip_stat.tcp.rst++;
#endif
BUF->flags = TCP_RST | TCP_ACK;
dev->d_len = UIP_IPTCPH_LEN;
BUF->tcpoffset = 5 << 4;
/* Flip the seqno and ackno fields in the TCP header. */
seqbyte = BUF->seqno[3];
BUF->seqno[3] = BUF->ackno[3];
BUF->ackno[3] = seqbyte;
seqbyte = BUF->seqno[2];
BUF->seqno[2] = BUF->ackno[2];
BUF->ackno[2] = seqbyte;
seqbyte = BUF->seqno[1];
BUF->seqno[1] = BUF->ackno[1];
BUF->ackno[1] = seqbyte;
seqbyte = BUF->seqno[0];
BUF->seqno[0] = BUF->ackno[0];
BUF->ackno[0] = seqbyte;
/* We also have to increase the sequence number we are
* acknowledging. If the least significant byte overflowed, we need
* to propagate the carry to the other bytes as well.
*/
if (++(BUF->ackno[3]) == 0)
{
if (++(BUF->ackno[2]) == 0)
{
if (++(BUF->ackno[1]) == 0)
{
++(BUF->ackno[0]);
}
}
}
/* Swap port numbers. */
tmp16 = BUF->srcport;
BUF->srcport = BUF->destport;
BUF->destport = tmp16;
/* Swap IP addresses. */
uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr);
/* And send out the RST packet */
uip_tcpsendcomplete(dev);
}
/****************************************************************************
* Name: uip_tcpack
*
* Description:
* Send the SYN or SYNACK response.
*
* 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
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
void uip_tcpack(struct uip_driver_s *dev, struct uip_conn *conn, uint8 ack)
{
/* Save the ACK bits */
BUF->flags = ack;
/* We send out the TCP Maximum Segment Size option with our ack. */
BUF->optdata[0] = TCP_OPT_MSS;
BUF->optdata[1] = TCP_OPT_MSS_LEN;
BUF->optdata[2] = (UIP_TCP_MSS) / 256;
BUF->optdata[3] = (UIP_TCP_MSS) & 255;
dev->d_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
/* Complete the common portions of the TCP message */
uip_tcpsendcommon(dev, conn);
}
#endif /* CONFIG_NET && CONFIG_NET_TCP */