/****************************************************************************
* net/send.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <nuttx/config.h>
#ifdef CONFIG_NET
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <arch/irq.h>
#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
* 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 uint8 send_interrupt(struct uip_driver_s *dev, struct uip_conn *conn, uint8 flags)
{
struct send_s *pstate = (struct send_s *)conn->data_private;
vdbg("flags: %02x state: %d\n", 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(flags))
{
if (pstate->snd_buflen > uip_mss(conn))
{
uip_send(dev, pstate->snd_buffer, uip_mss(conn));
}
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(flags))
{
/* Yes.. the data has been sent AND acknowledged */
if (pstate->snd_buflen > uip_mss(conn))
{
/* Not all data has been sent */
pstate->snd_sent += uip_mss(conn);
pstate->snd_buflen -= uip_mss(conn);
pstate->snd_buffer += uip_mss(conn);
/* 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->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 ((flags & (UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT)) != 0)
{
/* Stop further callbacks */
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);
}
return 0;
}
/****************************************************************************
* 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 = 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;
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 */
