/**************************************************************************** * net/send.c * * Copyright (C) 2007-2010 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "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 * COPYRIGHT OWNER OR CONTRIBUTORS 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 #if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) #include #include #include #include #include #include #include #include #include #ifndef CONFIG_NET_ARP_IPIN # include #endif #include "net_internal.h" #include "uip/uip_internal.h" /**************************************************************************** * Definitions ****************************************************************************/ #define TCPBUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN]) /**************************************************************************** * Private Types ****************************************************************************/ /* This structure holds the state of the send operation until it can be * operated upon from the interrupt level. */ struct send_s { FAR struct socket *snd_sock; /* Points to the parent socket structure */ FAR struct uip_callback_s *snd_cb; /* Reference to callback instance */ sem_t snd_sem; /* Used to wake up the waiting thread */ FAR const uint8_t *snd_buffer; /* Points to the buffer of data to send */ size_t snd_buflen; /* Number of bytes in the buffer to send */ ssize_t snd_sent; /* The number of bytes sent */ uint32_t snd_isn; /* Initial sequence number */ uint32_t snd_acked; /* The number of bytes acked */ #if defined(CONFIG_NET_SOCKOPTS) && !defined(CONFIG_DISABLE_CLOCK) uint32_t snd_time; /* last send time for determining timeout */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Function: send_timeout * * Description: * Check for send timeout. * * Parameters: * pstate send state structure * * Returned Value: * TRUE:timeout FALSE:no timeout * * Assumptions: * Running at the interrupt level * ****************************************************************************/ #if defined(CONFIG_NET_SOCKOPTS) && !defined(CONFIG_DISABLE_CLOCK) static inline int send_timeout(struct send_s *pstate) { FAR struct socket *psock = 0; /* Check for a timeout configured via setsockopts(SO_SNDTIMEO). * If none... we well let the send wait forever. */ psock = pstate->snd_sock; if (psock && psock->s_sndtimeo != 0) { /* Check if the configured timeout has elapsed */ return net_timeo(pstate->snd_time, psock->s_sndtimeo); } /* No timeout */ return FALSE; } #endif /* CONFIG_NET_SOCKOPTS && !CONFIG_DISABLE_CLOCK */ /**************************************************************************** * Function: send_interrupt * * Description: * This function is called from the interrupt level to perform the actual * send operation when polled by the uIP layer. * * Parameters: * dev The sructure of the network driver that caused the interrupt * conn The connection structure associated with the socket * flags Set of events describing why the callback was invoked * * Returned Value: * None * * Assumptions: * Running at the interrupt level * ****************************************************************************/ static uint16_t send_interrupt(struct uip_driver_s *dev, void *pvconn, void *pvpriv, uint16_t flags) { struct uip_conn *conn = (struct uip_conn*)pvconn; struct send_s *pstate = (struct send_s *)pvpriv; nllvdbg("flags: %04x acked: %d sent: %d\n", flags, pstate->snd_acked, pstate->snd_sent); /* If this packet contains an acknowledgement, then update the count of * acknowldged bytes. */ if ((flags & UIP_ACKDATA) != 0) { /* The current acknowledgement number number is the (relative) offset * of the of the next byte needed by the receiver. The snd_isn is the * offset of the first byte to send to the receiver. The difference * is the number of bytes to be acknowledged. */ pstate->snd_acked = uip_tcpgetsequence(TCPBUF->ackno) - pstate->snd_isn; nllvdbg("ACK: acked=%d sent=%d buflen=%d\n", pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen); /* Have all of the bytes in the buffer been sent and acknowledged? */ if (pstate->snd_acked >= pstate->snd_buflen) { /* Yes. Then pstate->snd_buflen should hold the number of bytes * actually sent. */ conn->unacked = 0; goto end_wait; } /* No.. fall through to send more data if necessary */ } /* Check if we are being asked to retransmit data */ else if ((flags & UIP_REXMIT) != 0) { /* Yes.. in this case, reset the number of bytes that have been sent * to the number of bytes that have been ACKed. */ pstate->snd_sent = pstate->snd_acked; /* Fall through to re-send data from the last that was ACKed */ } /* Check for a loss of connection */ else if ((flags & (UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT)) != 0) { /* Report not connected */ nllvdbg("Lost connection\n"); pstate->snd_sent = -ENOTCONN; goto end_wait; } /* Check if the outgoing packet is available (it may have been claimed * by a sendto interrupt serving a different thread). */ #if 0 /* We can't really support multiple senders on the same TCP socket */ else if (dev->d_sndlen > 0) { /* Another thread has beat us sending data, wait for the next poll */ return flags; } #endif /* We get here if (1) not all of the data has been ACKed, (2) we have been * asked to retransmit data, (3) the connection is still healthy, and (4) * the outgoing packet is available for our use. In this case, we are * now free to send more data to receiver -- UNLESS the buffer contains * unprocessing incoming data. In that event, we will have to wait for the * next polling cycle. */ if ((flags & UIP_NEWDATA) == 0 && pstate->snd_sent < pstate->snd_buflen) { uint32_t seqno; /* Get the amount of data that we can send in the next packet */ uint32_t sndlen = pstate->snd_buflen - pstate->snd_sent; if (sndlen > uip_mss(conn)) { sndlen = uip_mss(conn); } /* Set the sequence number for this packet. NOTE: uIP updates * sndseq on recept of ACK *before* this function is called. In that * case sndseq will point to the next unacknowledge byte (which might * have already been sent). We will overwrite the value of sndseq * here before the packet is sent. */ seqno = pstate->snd_sent + pstate->snd_isn; nllvdbg("SEND: sndseq %08x->%08x\n", conn->sndseq, seqno); uip_tcpsetsequence(conn->sndseq, seqno); /* Then set-up to send that amount of data. (this won't actually * happen until the polling cycle completes). */ uip_send(dev, &pstate->snd_buffer[pstate->snd_sent], sndlen); /* Check if the destination IP address is in the ARP table. If not, * then the send won't actually make it out... it will be replaced with * an ARP request. * * NOTE: If we are actually harvesting IP addresses on incomming IP * packets, then this check should be necessary; the MAC mapping should * already be in the ARP table. */ #ifndef CONFIG_NET_ARP_IPIN if (uip_arp_find(conn->ripaddr) != NULL) #endif { /* Update the amount of data sent (but not necessarily ACKed) */ pstate->snd_sent += sndlen; nllvdbg("SEND: acked=%d sent=%d buflen=%d\n", pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen); /* Update the send time */ #if defined(CONFIG_NET_SOCKOPTS) && !defined(CONFIG_DISABLE_CLOCK) pstate->snd_time = g_system_timer; #endif } } /* All data has been send and we are just waiting for ACK or re-tranmist * indications to complete the send. Check for a timeout. */ #if defined(CONFIG_NET_SOCKOPTS) && !defined(CONFIG_DISABLE_CLOCK) else if (send_timeout(pstate)) { /* Yes.. report the timeout */ nllvdbg("TCP timeout\n"); pstate->snd_sent = -EAGAIN; goto end_wait; } #endif /* CONFIG_NET_SOCKOPTS && !CONFIG_DISABLE_CLOCK */ /* Continue waiting */ return flags; end_wait: /* Do not allow any further callbacks */ pstate->snd_cb->flags = 0; pstate->snd_cb->priv = NULL; pstate->snd_cb->event = NULL; /* Wake up the waiting thread */ sem_post(&pstate->snd_sem); return flags; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Function: send * * Description: * The send() call may be used only when the socket is in a connected state * (so that the intended recipient is known). The only difference between * send() and write() is the presence of flags. With zero flags parameter, * send() is equivalent to write(). Also, send(sockfd,buf,len,flags) is * equivalent to sendto(sockfd,buf,len,flags,NULL,0). * * Parameters: * sockfd Socket descriptor of socket * buf Data to send * len Length of data to send * flags Send flags * * Returned Value: * On success, returns the number of characters sent. On error, * -1 is returned, and errno is set appropriately: * * EAGAIN or EWOULDBLOCK * The socket is marked non-blocking and the requested operation * would block. * EBADF * An invalid descriptor was specified. * ECONNRESET * Connection reset by peer. * EDESTADDRREQ * The socket is not connection-mode, and no peer address is set. * EFAULT * An invalid user space address was specified for a parameter. * EINTR * A signal occurred before any data was transmitted. * EINVAL * Invalid argument passed. * EISCONN * The connection-mode socket was connected already but a recipient * was specified. (Now either this error is returned, or the recipient * specification is ignored.) * EMSGSIZE * The socket type requires that message be sent atomically, and the * size of the message to be sent made this impossible. * ENOBUFS * The output queue for a network interface was full. This generally * indicates that the interface has stopped sending, but may be * caused by transient congestion. * ENOMEM * No memory available. * ENOTCONN * The socket is not connected, and no target has been given. * ENOTSOCK * The argument s is not a socket. * EOPNOTSUPP * Some bit in the flags argument is inappropriate for the socket * type. * EPIPE * The local end has been shut down on a connection oriented socket. * In this case the process will also receive a SIGPIPE unless * MSG_NOSIGNAL is set. * * Assumptions: * ****************************************************************************/ ssize_t send(int sockfd, const void *buf, size_t len, int flags) { FAR struct socket *psock = sockfd_socket(sockfd); struct send_s state; irqstate_t save; int err; int ret = OK; /* Verify that the sockfd corresponds to valid, allocated socket */ if (!psock || psock->s_crefs <= 0) { err = EBADF; goto errout; } /* If this is a connected socket, then return ENOTCONN */ if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags)) { err = ENOTCONN; goto errout; } /* Set the socket state to sending */ psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND); /* Perform the TCP send operation */ /* Initialize the state structure. This is done with interrupts * disabled because we don't want anything to happen until we * are ready. */ save = irqsave(); memset(&state, 0, sizeof(struct send_s)); (void)sem_init(&state. snd_sem, 0, 0); /* Doesn't really fail */ state.snd_sock = psock; /* Socket descriptor to use */ state.snd_buflen = len; /* Number of bytes to send */ state.snd_buffer = buf; /* Buffer to send from */ if (len > 0) { struct uip_conn *conn = (struct uip_conn*)psock->s_conn; /* Allocate resources to receive a callback */ state.snd_cb = uip_tcpcallbackalloc(conn); if (state.snd_cb) { /* Get the initial sequence number that will be used */ state.snd_isn = uip_tcpgetsequence(conn->sndseq); /* Update the initial time for calculating timeouts */ #if defined(CONFIG_NET_SOCKOPTS) && !defined(CONFIG_DISABLE_CLOCK) state.snd_time = g_system_timer; #endif /* Set up the callback in the connection */ state.snd_cb->flags = UIP_ACKDATA|UIP_REXMIT|UIP_POLL|UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT; state.snd_cb->priv = (void*)&state; state.snd_cb->event = send_interrupt; /* Notify the device driver of the availaibilty of TX data */ netdev_txnotify(&conn->ripaddr); /* Wait for the send to complete or an error to occur: NOTES: (1) * sem_wait will also terminate if a signal is received, (2) interrupts * are disabled! They will be re-enabled while the task sleeps and * automatically re-enabled when the task restarts. */ ret = sem_wait(&state. snd_sem); /* Make sure that no further interrupts are processed */ uip_tcpcallbackfree(conn, state.snd_cb); } } sem_destroy(&state. snd_sem); irqrestore(save); /* Set the socket state to idle */ psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE); /* Check for a errors. Errors are signaled by negative errno values * for the send length */ if (state.snd_sent < 0) { err = state.snd_sent; goto errout; } /* If sem_wait failed, then we were probably reawakened by a signal. In * this case, sem_wait will have set errno appropriately. */ if (ret < 0) { err = -ret; goto errout; } /* Return the number of bytes actually sent */ return state.snd_sent; errout: *get_errno_ptr() = err; return ERROR; } #endif /* CONFIG_NET && CONFIG_NET_TCP */