nuttx/net/usrsock/usrsock_accept.c

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/****************************************************************************
* net/usrsock/usrsock_accept.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_USRSOCK)
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/net/net.h>
#include <nuttx/net/usrsock.h>
#include "usrsock/usrsock.h"
/****************************************************************************
* Private Functions
****************************************************************************/
static uint16_t accept_event(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct usrsock_data_reqstate_s *pstate = pvpriv;
FAR struct usrsock_conn_s *conn = pstate->reqstate.conn;
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 connection, 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("accept 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_accept_request
****************************************************************************/
static int do_accept_request(FAR struct usrsock_conn_s *conn,
socklen_t addrlen)
{
struct usrsock_request_accept_s req =
{
};
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struct iovec bufs[1];
if (addrlen > UINT16_MAX)
{
addrlen = UINT16_MAX;
}
/* Prepare request for daemon to read. */
req.head.reqid = USRSOCK_REQUEST_ACCEPT;
req.usockid = conn->usockid;
req.max_addrlen = addrlen;
bufs[0].iov_base = &req;
bufs[0].iov_len = sizeof(req);
return usrsock_do_request(conn, bufs, ARRAY_SIZE(bufs));
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: usrsock_accept
*
* Description:
* The usrsock_accept function is used with connection-based socket
* types (SOCK_STREAM, SOCK_SEQPACKET and SOCK_RDM). It extracts the first
* connection request on the queue of pending connections, creates a new
* connected socket with mostly the same properties as 'psock', and
* allocates a new socket descriptor for the socket, which is returned. The
* newly created socket is no longer in the listening state. The original
* socket 'psock' is unaffected by this call. Per file descriptor flags
* are not inherited across an usrsock_accept.
*
* The 'psock' argument is a socket descriptor that has been created with
* socket(), bound to a local address with bind(), and is listening for
* connections after a call to listen().
*
* On return, the 'addr' structure is filled in with the address of the
* connecting entity. The 'addrlen' argument initially contains the size
* of the structure pointed to by 'addr'; on return it will contain the
* actual length of the address returned.
*
* If no pending connections are present on the queue, and the socket is
* not marked as non-blocking, usrsock_accept blocks the caller until a
* connection is present. If the socket is marked non-blocking and no
* pending connections are present on the queue, usrsock_accept returns
* EAGAIN.
*
* Parameters:
* psock Reference to the listening socket structure
* addr Receives the address of the connecting client
* addrlen Input: allocated size of 'addr',
* Return: returned size of 'addr'
* newsock Location to return the accepted socket information.
*
* Returned Value:
* Returns 0 (OK) on success. On failure, it returns a negated errno
* value. See accept() for a description of the appropriate error value.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
int usrsock_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
FAR socklen_t *addrlen, FAR struct socket *newsock)
{
FAR struct usrsock_conn_s *conn = psock->s_conn;
struct usrsock_data_reqstate_s state =
{
};
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FAR struct usrsock_conn_s *newconn;
struct iovec inbufs[2];
socklen_t inaddrlen = 0;
socklen_t outaddrlen = 0;
int ret;
DEBUGASSERT(conn);
if (addrlen)
{
if (*addrlen > 0 && addr == NULL)
{
return -EINVAL;
}
inaddrlen = *addrlen;
}
net_lock();
if (conn->state == USRSOCK_CONN_STATE_UNINITIALIZED ||
conn->state == USRSOCK_CONN_STATE_ABORTED)
{
/* Invalid state or closed by daemon. */
ninfo("usockid=%d; accept() with uninitialized usrsock.\n",
conn->usockid);
ret = (conn->state == USRSOCK_CONN_STATE_ABORTED) ? -EPIPE :
-ECONNRESET;
goto errout_unlock;
}
if (conn->state == USRSOCK_CONN_STATE_CONNECTING)
{
/* Connecting. */
ninfo("usockid=%d; socket still connecting.\n",
conn->usockid);
ret = -EAGAIN;
goto errout_unlock;
}
if (!conn->connected)
{
/* Not connected. */
ninfo("usockid=%d; socket not connected.\n",
conn->usockid);
ret = -ENOTCONN;
goto errout_unlock;
}
/* Allocate the usrsock socket connection structure and save in the new
* socket instance.
*/
newconn = usrsock_alloc();
if (!newconn)
{
/* Failed to reserve a connection structure */
ret = -ENOMEM;
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 = -EPIPE;
goto errout_free_conn;
}
/* Check if need to wait for connection to become available. */
if (!(conn->flags & USRSOCK_EVENT_RECVFROM_AVAIL))
{
if (_SS_ISNONBLOCK(conn->sconn.s_flags))
{
/* Nothing to receive from daemon side. */
ret = -EAGAIN;
goto errout_free_conn;
}
/* Wait accept to become avail. */
ret = usrsock_setup_data_request_callback(
conn, &state, accept_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_free_conn;
}
/* Wait for receive-avail (or abort, or timeout, or signal). */
ret = net_timedwait(&state.reqstate.recvsem,
_SO_TIMEOUT(conn->sconn.s_rcvtimeo));
if (ret < 0)
{
if (ret == -ETIMEDOUT)
{
ninfo("accept timedout\n");
ret = -EAGAIN;
}
else if (ret == -EINTR)
{
ninfo("accept interrupted\n");
}
else
{
nerr("net_timedwait errno: %d\n", ret);
DEBUGPANIC();
}
}
usrsock_teardown_data_request_callback(&state);
/* Did wait timeout or got signal? */
if (ret != 0)
{
goto errout_free_conn;
}
/* Was socket aborted? */
if (conn->state == USRSOCK_CONN_STATE_ABORTED)
{
ret = -EPIPE;
goto errout_free_conn;
}
/* Did remote disconnect? */
if (conn->flags & USRSOCK_EVENT_REMOTE_CLOSED)
{
ret = -EPIPE;
goto errout_free_conn;
}
DEBUGASSERT(conn->flags & USRSOCK_EVENT_RECVFROM_AVAIL);
}
/* Set up event callback for usrsock. */
ret = usrsock_setup_data_request_callback(
conn, &state, accept_event,
USRSOCK_EVENT_ABORT | USRSOCK_EVENT_REQ_COMPLETE);
if (ret < 0)
{
nwarn("usrsock_setup_request_callback failed: %d\n", ret);
goto errout_free_conn;
}
inbufs[0].iov_base = addr;
inbufs[0].iov_len = inaddrlen;
inbufs[1].iov_base = &newconn->usockid;
inbufs[1].iov_len = sizeof(newconn->usockid);
usrsock_setup_datain(conn, inbufs, ARRAY_SIZE(inbufs));
/* We might start getting events for this socket right after
* returning to daemon, so setup 'newconn' already here.
*/
newconn->state = USRSOCK_CONN_STATE_READY;
/* Request user-space daemon to accept socket. */
ret = do_accept_request(conn, inaddrlen);
if (ret >= 0)
{
/* Wait for completion of request. */
net_lockedwait_uninterruptible(&state.reqstate.recvsem);
ret = state.reqstate.result;
DEBUGASSERT(state.valuelen <= inaddrlen);
DEBUGASSERT(state.valuelen <= state.valuelen_nontrunc);
if (ret >= 0)
{
newconn->connected = true;
newconn->type = conn->type;
newconn->crefs = 1;
newsock->s_type = psock->s_type;
newsock->s_domain = psock->s_domain;
newsock->s_conn = newconn;
newsock->s_sockif = psock->s_sockif;
/* Store length of 'from' address that was available at
* daemon-side.
*/
outaddrlen = state.valuelen_nontrunc;
ret = OK;
}
}
usrsock_teardown_datain(conn);
usrsock_teardown_data_request_callback(&state);
}
while (ret == -EAGAIN);
if (ret >= 0)
{
goto errout_unlock;
}
errout_free_conn:
usrsock_free(newconn);
errout_unlock:
net_unlock();
if (addrlen)
{
*addrlen = outaddrlen;
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_USRSOCK */