| /**************************************************************************** |
| * net/tcp/tcp_appsend.c |
| * |
| * Copyright (C) 2007-2010, 2014 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <gnutt@nuttx.org> |
| * |
| * 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 <stdint.h> |
| #include <assert.h> |
| #include <debug.h> |
| |
| #include <nuttx/net/netconfig.h> |
| #include <nuttx/net/uip.h> |
| #include <nuttx/net/netdev.h> |
| |
| #include "uip/uip.h" |
| #include "tcp/tcp.h" |
| |
| /**************************************************************************** |
| * Pre-processor Definitions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Public Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: tcp_appsend |
| * |
| * Description: |
| * Handle application or TCP protocol response. If this function is called |
| * with dev->d_sndlen > 0, then this is an application attempting to send |
| * packet. |
| * |
| * Parameters: |
| * dev - The device driver structure to use in the send operation |
| * conn - The TCP connection structure holding connection information |
| * result - App result event sent |
| * |
| * Return: |
| * None |
| * |
| * Assumptions: |
| * Called from the interrupt level or with interrupts disabled. |
| * |
| ****************************************************************************/ |
| |
| void tcp_appsend(FAR struct uip_driver_s *dev, FAR struct tcp_conn_s *conn, |
| uint16_t result) |
| { |
| /* Handle the result based on the application response */ |
| |
| nllvdbg("result: %04x d_sndlen: %d conn->unacked: %d\n", |
| result, dev->d_sndlen, conn->unacked); |
| |
| /* Check for connection aborted */ |
| |
| if ((result & UIP_ABORT) != 0) |
| { |
| dev->d_sndlen = 0; |
| conn->tcpstateflags = UIP_CLOSED; |
| nllvdbg("TCP state: UIP_CLOSED\n"); |
| |
| tcp_send(dev, conn, TCP_RST | TCP_ACK, UIP_IPTCPH_LEN); |
| } |
| |
| /* Check for connection closed */ |
| |
| else if ((result & UIP_CLOSE) != 0) |
| { |
| conn->tcpstateflags = UIP_FIN_WAIT_1; |
| conn->unacked = 1; |
| conn->nrtx = 0; |
| nllvdbg("TCP state: UIP_FIN_WAIT_1\n"); |
| |
| dev->d_sndlen = 0; |
| tcp_send(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN); |
| } |
| |
| /* None of the above */ |
| |
| else |
| { |
| #ifdef CONFIG_NET_TCP_WRITE_BUFFERS |
| DEBUGASSERT(dev->d_sndlen >= 0 && dev->d_sndlen <= conn->mss); |
| #else |
| /* If d_sndlen > 0, the application has data to be sent. */ |
| |
| if (dev->d_sndlen > 0) |
| { |
| /* Remember how much data we send out now so that we know |
| * when everything has been acknowledged. Just increment the amount |
| * of data sent. This will be needed in sequence number calculations |
| * and we know that this is not a re-transmission. Retransmissions |
| * do not go through this path. |
| */ |
| |
| conn->unacked += dev->d_sndlen; |
| |
| /* The application cannot send more than what is allowed by the |
| * MSS (the minumum of the MSS and the available window). |
| */ |
| |
| DEBUGASSERT(dev->d_sndlen <= conn->mss); |
| } |
| |
| conn->nrtx = 0; |
| #endif |
| /* Then handle the rest of the operation just as for the rexmit case */ |
| |
| tcp_rexmit(dev, conn, result); |
| } |
| } |
| |
| /**************************************************************************** |
| * Name: tcp_rexmit |
| * |
| * Description: |
| * Handle application retransmission |
| * |
| * Parameters: |
| * dev - The device driver structure to use in the send operation |
| * conn - The TCP connection structure holding connection information |
| * result - App result event sent |
| * |
| * Return: |
| * None |
| * |
| * Assumptions: |
| * Called from the interrupt level or with interrupts disabled. |
| * |
| ****************************************************************************/ |
| |
| void tcp_rexmit(FAR struct uip_driver_s *dev, FAR struct tcp_conn_s *conn, |
| uint16_t result) |
| { |
| nllvdbg("result: %04x d_sndlen: %d conn->unacked: %d\n", |
| result, dev->d_sndlen, conn->unacked); |
| |
| dev->d_appdata = dev->d_snddata; |
| |
| /* If the application has data to be sent, or if the incoming packet had |
| * new data in it, we must send out a packet. |
| */ |
| |
| #ifdef CONFIG_NET_TCP_WRITE_BUFFERS |
| if (dev->d_sndlen > 0) |
| #else |
| if (dev->d_sndlen > 0 && conn->unacked > 0) |
| #endif |
| { |
| /* We always set the ACK flag in response packets adding the length of |
| * the IP and TCP headers. |
| */ |
| |
| tcp_send(dev, conn, TCP_ACK | TCP_PSH, dev->d_sndlen + UIP_TCPIP_HLEN); |
| } |
| |
| /* If there is no data to send, just send out a pure ACK if one is requested`. */ |
| |
| else if ((result & UIP_SNDACK) != 0) |
| { |
| tcp_send(dev, conn, TCP_ACK, UIP_TCPIP_HLEN); |
| } |
| |
| /* There is nothing to do -- drop the packet */ |
| |
| else |
| { |
| dev->d_len = 0; |
| } |
| } |
| #endif /* CONFIG_NET && CONFIG_NET_TCP */ |