diff options
Diffstat (limited to 'nuttx/net/uip/uip_tcptimer.c')
| -rw-r--r-- | nuttx/net/uip/uip_tcptimer.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/nuttx/net/uip/uip_tcptimer.c b/nuttx/net/uip/uip_tcptimer.c new file mode 100644 index 000000000..c95376ab0 --- /dev/null +++ b/nuttx/net/uip/uip_tcptimer.c @@ -0,0 +1,250 @@ +/**************************************************************************** + * net/uip/uip_tcptimer.c + * Poll for the availability of TCP TX data + * + * Copyright (C) 2007-2010 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 <stdint.h> +#include <debug.h> + +#include <nuttx/net/uip/uipopt.h> +#include <nuttx/net/uip/uip.h> +#include <nuttx/net/uip/uip-arch.h> + +#include "uip_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: uip_tcptimer + * + * Description: + * Handle a TCP timer expiration for the provided TCP connection + * + * Parameters: + * dev - The device driver structure to use in the send operation + * conn - The TCP "connection" to poll for TX data + * hsed - The polling interval in halves of a second + * + * Return: + * None + * + * Assumptions: + * Called from the interrupt level or with interrupts disabled. + * + ****************************************************************************/ + +void uip_tcptimer(struct uip_driver_s *dev, struct uip_conn *conn, int hsec) +{ + uint8_t result; + + dev->d_snddata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN]; + dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN]; + + /* Increase the TCP sequence number */ + + uip_tcpnextsequence(); + + /* Reset the length variables. */ + + dev->d_len = 0; + dev->d_sndlen = 0; + + /* Check if the connection is in a state in which we simply wait + * for the connection to time out. If so, we increase the + * connection's timer and remove the connection if it times + * out. + */ + + if (conn->tcpstateflags == UIP_TIME_WAIT || conn->tcpstateflags == UIP_FIN_WAIT_2) + { + /* Increment the connection timer */ + + (conn->timer) += hsec; + if (conn->timer >= UIP_TIME_WAIT_TIMEOUT) + { + conn->tcpstateflags = UIP_CLOSED; + nllvdbg("TCP state: UIP_CLOSED\n"); + } + } + else if (conn->tcpstateflags != UIP_CLOSED) + { + /* If the connection has outstanding data, we increase the connection's + * timer and see if it has reached the RTO value in which case we + * retransmit. + */ + + if (conn->unacked > 0) + { + /* The connection has outstanding data */ + + if (conn->timer > hsec) + { + /* Will not yet decrement to zero */ + + conn->timer -= hsec; + } + else + { + /* Will decrement to zero */ + + conn->timer = 0; + + /* Should we close the connection? */ + + if (conn->nrtx == UIP_MAXRTX || + ((conn->tcpstateflags == UIP_SYN_SENT || + conn->tcpstateflags == UIP_SYN_RCVD) && + conn->nrtx == UIP_MAXSYNRTX)) + { + conn->tcpstateflags = UIP_CLOSED; + nllvdbg("TCP state: UIP_CLOSED\n"); + + /* We call uip_tcpcallback() with UIP_TIMEDOUT to + * inform the application that the connection has + * timed out. + */ + + result = uip_tcpcallback(dev, conn, UIP_TIMEDOUT); + + /* We also send a reset packet to the remote host. */ + + uip_tcpsend(dev, conn, TCP_RST | TCP_ACK, UIP_IPTCPH_LEN); + goto done; + } + + /* Exponential backoff. */ + + conn->timer = UIP_RTO << (conn->nrtx > 4 ? 4: conn->nrtx); + (conn->nrtx)++; + + /* Ok, so we need to retransmit. We do this differently + * depending on which state we are in. In ESTABLISHED, we + * call upon the application so that it may prepare the + * data for the retransmit. In SYN_RCVD, we resend the + * SYNACK that we sent earlier and in LAST_ACK we have to + * retransmit our FINACK. + */ + +#ifdef CONFIG_NET_STATISTICS + uip_stat.tcp.rexmit++; +#endif + switch(conn->tcpstateflags & UIP_TS_MASK) + { + case UIP_SYN_RCVD: + /* In the SYN_RCVD state, we should retransmit our + * SYNACK. + */ + + uip_tcpack(dev, conn, TCP_ACK | TCP_SYN); + goto done; + + case UIP_SYN_SENT: + /* In the SYN_SENT state, we retransmit out SYN. */ + + uip_tcpack(dev, conn, TCP_SYN); + goto done; + + case UIP_ESTABLISHED: + /* In the ESTABLISHED state, we call upon the application + * to do the actual retransmit after which we jump into + * the code for sending out the packet. + */ + + result = uip_tcpcallback(dev, conn, UIP_REXMIT); + uip_tcprexmit(dev, conn, result); + goto done; + + case UIP_FIN_WAIT_1: + case UIP_CLOSING: + case UIP_LAST_ACK: + /* In all these states we should retransmit a FINACK. */ + + uip_tcpsend(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN); + goto done; + } + } + } + + /* The connection does not have outstanding data */ + + else if ((conn->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) + { + /* If there was no need for a retransmission, we poll the + * application for new data. + */ + + result = uip_tcpcallback(dev, conn, UIP_POLL); + uip_tcpappsend(dev, conn, result); + goto done; + } + } + + /* Nothing to be done */ + + dev->d_len = 0; + +done: + return; +} + +#endif /* CONFIG_NET && CONFIG_NET_TCP */ |