nuttx/net/usrsock/usrsock_recvfrom.c
chao.an c65d8e6a23 net/socket: add MSG_DONTWAIT support
MSG_DONTWAIT (since Linux 2.2)
  Enables nonblocking operation; if the operation would block, the
  call fails with the error EAGAIN or EWOULDBLOCK. This provides
  similar behavior to setting the O_NONBLOCK flag (via the fcntl(2)
  F_SETFL operation), but differs in that MSG_DONTWAIT is a per-call
  option, whereas O_NONBLOCK is a setting on the open file description
  (see open(2)), which will affect all threads in the calling process
  and as well as other processes that hold file descriptors referring
  to the same open file description.
2020-02-19 12:21:28 -06:00

441 lines
12 KiB
C

/****************************************************************************
* net/usrsock/usrsock_recvfrom.c
*
* Copyright (C) 2015, 2017 Haltian Ltd. All rights reserved.
* Author: Jussi Kivilinna <jussi.kivilinna@haltian.com>
*
* 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>
#if defined(CONFIG_NET) && defined(CONFIG_NET_USRSOCK)
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <arch/irq.h>
#include <sys/socket.h>
#include <nuttx/net/net.h>
#include <nuttx/net/usrsock.h>
#include "usrsock/usrsock.h"
/****************************************************************************
* Private Functions
****************************************************************************/
static uint16_t recvfrom_event(FAR struct net_driver_s *dev,
FAR void *pvconn, FAR void *pvpriv,
uint16_t flags)
{
FAR struct usrsock_data_reqstate_s *pstate = pvpriv;
FAR struct usrsock_conn_s *conn = pvconn;
if (flags & USRSOCK_EVENT_ABORT)
{
ninfo("socket aborted.\n");
pstate->reqstate.result = -ECONNABORTED;
pstate->valuelen = 0;
pstate->valuelen_nontrunc = 0;
/* Stop further callbacks */
pstate->reqstate.cb->flags = 0;
pstate->reqstate.cb->priv = NULL;
pstate->reqstate.cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->reqstate.recvsem);
}
else if (flags & USRSOCK_EVENT_REQ_COMPLETE)
{
ninfo("request completed.\n");
pstate->reqstate.result = conn->resp.result;
if (pstate->reqstate.result < 0)
{
pstate->valuelen = 0;
pstate->valuelen_nontrunc = 0;
}
else
{
pstate->valuelen = conn->resp.valuelen;
pstate->valuelen_nontrunc = conn->resp.valuelen_nontrunc;
}
if (pstate->reqstate.result >= 0 ||
pstate->reqstate.result == -EAGAIN)
{
/* After reception of data, mark input not ready. Daemon will
* send event to restore this flag.
*/
conn->flags &= ~USRSOCK_EVENT_RECVFROM_AVAIL;
}
/* Stop further callbacks */
pstate->reqstate.cb->flags = 0;
pstate->reqstate.cb->priv = NULL;
pstate->reqstate.cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->reqstate.recvsem);
}
else if (flags & USRSOCK_EVENT_REMOTE_CLOSED)
{
ninfo("remote closed.\n");
pstate->reqstate.result = -EPIPE;
/* Stop further callbacks */
pstate->reqstate.cb->flags = 0;
pstate->reqstate.cb->priv = NULL;
pstate->reqstate.cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->reqstate.recvsem);
}
else if (flags & USRSOCK_EVENT_RECVFROM_AVAIL)
{
ninfo("recvfrom avail.\n");
flags &= ~USRSOCK_EVENT_RECVFROM_AVAIL;
/* Stop further callbacks */
pstate->reqstate.cb->flags = 0;
pstate->reqstate.cb->priv = NULL;
pstate->reqstate.cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->reqstate.recvsem);
}
return flags;
}
/****************************************************************************
* Name: do_recvfrom_request
****************************************************************************/
static int do_recvfrom_request(FAR struct usrsock_conn_s *conn, size_t buflen,
socklen_t addrlen)
{
struct usrsock_request_recvfrom_s req =
{
};
struct iovec bufs[1];
if (addrlen > UINT16_MAX)
{
addrlen = UINT16_MAX;
}
if (buflen > UINT16_MAX)
{
buflen = UINT16_MAX;
}
/* Prepare request for daemon to read. */
req.head.reqid = USRSOCK_REQUEST_RECVFROM;
req.usockid = conn->usockid;
req.max_addrlen = addrlen;
req.max_buflen = buflen;
bufs[0].iov_base = (FAR void *)&req;
bufs[0].iov_len = sizeof(req);
return usrsockdev_do_request(conn, bufs, ARRAY_SIZE(bufs));
}
/****************************************************************************
* Name: usrsock_recvfrom
*
* Description:
* recvfrom() receives messages from a socket, and may be used to receive
* data on a socket whether or not it is connection-oriented.
*
* If from is not NULL, and the underlying protocol provides the source
* address, this source address is filled in. The argument fromlen
* initialized to the size of the buffer associated with from, and modified
* on return to indicate the actual size of the address stored there.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* buf Buffer to receive data
* len Length of buffer
* flags Receive flags (ignored)
* from Address of source (may be NULL)
* fromlen The length of the address structure
*
****************************************************************************/
ssize_t usrsock_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
FAR struct usrsock_conn_s *conn = psock->s_conn;
struct usrsock_data_reqstate_s state =
{
};
struct iovec inbufs[2];
socklen_t addrlen = 0;
socklen_t outaddrlen = 0;
ssize_t ret;
DEBUGASSERT(conn);
if (fromlen)
{
if (*fromlen > 0 && from == NULL)
{
return -EINVAL;
}
addrlen = *fromlen;
}
net_lock();
if (conn->state == USRSOCK_CONN_STATE_UNINITIALIZED ||
conn->state == USRSOCK_CONN_STATE_ABORTED)
{
/* Invalid state or closed by daemon. */
ninfo("usockid=%d; connect() with uninitialized usrsock.\n",
conn->usockid);
ret = (conn->state == USRSOCK_CONN_STATE_ABORTED) ? -EPIPE :
-ECONNRESET;
goto errout_unlock;
}
if (conn->type == SOCK_STREAM || conn->type == SOCK_SEQPACKET)
{
if (!conn->connected)
{
if (conn->state == USRSOCK_CONN_STATE_CONNECTING)
{
/* Connecting. */
ninfo("usockid=%d; socket still connecting.\n",
conn->usockid);
ret = -EAGAIN;
goto errout_unlock;
}
else
{
/* Not connected. */
ninfo("usockid=%d; socket not connected.\n",
conn->usockid);
ret = -ENOTCONN;
goto errout_unlock;
}
}
}
if (conn->state == USRSOCK_CONN_STATE_CONNECTING)
{
/* Non-blocking connecting. */
ninfo("usockid=%d; socket still connecting.\n",
conn->usockid);
ret = -EAGAIN;
goto errout_unlock;
}
do
{
/* Check if remote end has closed connection. */
if (conn->flags & USRSOCK_EVENT_REMOTE_CLOSED)
{
ninfo("usockid=%d; remote closed (EOF).\n", conn->usockid);
ret = 0;
goto errout_unlock;
}
/* Check if need to wait for receive data to become available. */
if (!(conn->flags & USRSOCK_EVENT_RECVFROM_AVAIL))
{
if (_SS_ISNONBLOCK(psock->s_flags) || (flags & MSG_DONTWAIT) != 0)
{
/* Nothing to receive from daemon side. */
ret = -EAGAIN;
goto errout_unlock;
}
/* Wait recv to become avail. */
ret = usrsock_setup_data_request_callback(
conn, &state, recvfrom_event,
USRSOCK_EVENT_ABORT | USRSOCK_EVENT_RECVFROM_AVAIL |
USRSOCK_EVENT_REMOTE_CLOSED);
if (ret < 0)
{
nwarn("usrsock_setup_request_callback failed: %d\n", ret);
goto errout_unlock;
}
/* Wait for receive-avail (or abort, or timeout, or signal). */
ret = net_timedwait(&state.reqstate.recvsem,
_SO_TIMEOUT(psock->s_rcvtimeo));
if (ret < 0)
{
if (ret == -ETIMEDOUT)
{
ninfo("recvfrom timedout\n");
ret = -EAGAIN;
}
else if (ret == -EINTR)
{
ninfo("recvfrom interrupted\n");
}
else
{
nerr("net_timedwait errno: %d\n", ret);
DEBUGASSERT(false);
}
}
usrsock_teardown_data_request_callback(&state);
/* Did wait timeout or got signal? */
if (ret != 0)
{
goto errout_unlock;
}
/* Was socket aborted? */
if (conn->state == USRSOCK_CONN_STATE_ABORTED)
{
ret = -EPIPE;
goto errout_unlock;
}
/* Did remote disconnect? */
if (conn->flags & USRSOCK_EVENT_REMOTE_CLOSED)
{
ret = 0;
goto errout_unlock;
}
DEBUGASSERT(conn->flags & USRSOCK_EVENT_RECVFROM_AVAIL);
}
/* Set up event callback for usrsock. */
ret = usrsock_setup_data_request_callback(
conn, &state, recvfrom_event,
USRSOCK_EVENT_ABORT | USRSOCK_EVENT_REQ_COMPLETE);
if (ret < 0)
{
nwarn("usrsock_setup_request_callback failed: %d\n", ret);
goto errout_unlock;
}
inbufs[0].iov_base = (FAR void *)from;
inbufs[0].iov_len = addrlen;
inbufs[1].iov_base = (FAR void *)buf;
inbufs[1].iov_len = len;
usrsock_setup_datain(conn, inbufs, ARRAY_SIZE(inbufs));
/* Request user-space daemon to close socket. */
ret = do_recvfrom_request(conn, len, addrlen);
if (ret >= 0)
{
/* Wait for completion of request. */
net_lockedwait_uninterruptible(&state.reqstate.recvsem);
ret = state.reqstate.result;
DEBUGASSERT(ret <= (ssize_t)len);
DEBUGASSERT(state.valuelen <= addrlen);
DEBUGASSERT(state.valuelen <= state.valuelen_nontrunc);
if (ret >= 0)
{
/* Store length of 'from' address that was available at
* daemon-side.
*/
outaddrlen = state.valuelen_nontrunc;
}
}
usrsock_teardown_datain(conn);
usrsock_teardown_data_request_callback(&state);
}
while (ret == -EAGAIN);
errout_unlock:
net_unlock();
if (fromlen)
{
*fromlen = outaddrlen;
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_USRSOCK */