/**************************************************************************** * net/send.c * * Copyright (C) 2007 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 #ifdef CONFIG_NET #include #include #include #include #include #include #include "net-internal.h" /**************************************************************************** * Definitions ****************************************************************************/ #define STATE_POLLWAIT 1 #define STATE_DATA_SENT 2 /**************************************************************************** * 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 */ sem_t snd_sem; /* Used to wake up the waiting thread */ FAR const uint8 *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 */ uint8 snd_state; /* The state of the send operation. */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * 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 * private An instance of struct send_s cast to void* * * Returned Value: * None * * Assumptions: * Running at the interrupt level * ****************************************************************************/ static void send_interrupt(struct uip_driver_s *dev, void *private) { struct send_s *pstate = (struct send_s *)private; struct uip_conn *conn; vdbg("uip_flags: %02x state: %d\n", uip_flags, pstate->snd_state); /* If the data has not been sent OR if it needs to be retransmitted, * then send it now. */ if (pstate->snd_state != STATE_DATA_SENT || uip_rexmit_event()) { if (pstate->snd_buflen > uip_mss()) { uip_send(dev, pstate->snd_buffer, uip_mss()); } else { uip_send(dev, pstate->snd_buffer, pstate->snd_buflen); } pstate->snd_state = STATE_DATA_SENT; } /* Check if all data has been sent and acknowledged */ else if (pstate->snd_state == STATE_DATA_SENT && uip_ack_event()) { /* Yes.. the data has been sent AND acknowledge */ if (pstate->snd_buflen > uip_mss()) { /* Not all data has been sent */ pstate->snd_sent += uip_mss(); pstate->snd_buflen -= uip_mss(); pstate->snd_buffer += uip_mss(); /* Send again on the next poll */ pstate->snd_state = STATE_POLLWAIT; } else { /* All data has been sent */ pstate->snd_sent += pstate->snd_buflen; pstate->snd_buffer += pstate->snd_buflen; pstate->snd_buflen = 0; /* Don't allow any further call backs. */ conn = (struct uip_conn *)pstate->snd_sock->s_conn; conn->data_private = NULL; conn->data_event = NULL; /* Wake up the waiting thread, returning the number of bytes * actually sent. */ sem_post(&pstate->snd_sem); } } /* Check for a loss of connection */ else if ((uip_flags & (UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT)) != 0) { /* Stop further callbacks */ conn = (struct uip_conn *)pstate->snd_sock->s_conn; conn->data_private = NULL; conn->data_event = NULL; /* Report not connected */ pstate->snd_sent = -ENOTCONN; /* Wake up the waiting thread */ sem_post(&pstate->snd_sem); } } /**************************************************************************** * 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 uip_conn *conn; struct send_s state; irqstate_t save; int err; int ret; /* 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; state.snd_buflen = len; state.snd_buffer = buf; state.snd_state = STATE_POLLWAIT; if (len > 0) { /* Set up the callback in the connection */ conn = (struct uip_conn *)psock->s_conn; conn->data_private = (void*)&state; conn->data_event = send_interrupt; /* 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 */ conn->data_private = NULL; conn->data_event = NULL; } 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 */