nuttx/net/local/local_recvfrom.c

257 lines
8.2 KiB
C

/****************************************************************************
* net/local/local_recvfrom.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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_LOCAL)
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/net/net.h>
#include "socket/socket.h"
#include "local/local.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef MIN
# define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_fifo_read
*
* Description:
* A thin layer aroudn local_fifo_read that handles socket-related loss-of-
* connection events.
*
****************************************************************************/
static int psock_fifo_read(FAR struct socket *psock, FAR void *buf,
FAR size_t *readlen)
{
FAR struct local_conn_s *conn = (FAR struct local_conn_s *)psock->s_conn;
int ret;
ret = local_fifo_read(conn->lc_infd, buf, readlen);
if (ret < 0)
{
/* -ECONNRESET is a special case. We may or not have received
* data, then the peer closed the connection.
*/
if (ret == -ECONNRESET)
{
ndbg("ERROR: Lost connection: %d\n", ret);
/* Report an ungraceful loss of connection. This should
* eventually be reported as ENOTCONN.
*/
psock->s_flags &= ~(_SF_CONNECTED |_SF_CLOSED);
conn->lc_state = LOCAL_STATE_DISCONNECTED;
/* Did we receive any data? */
if (*readlen <= 0)
{
/* No.. return the ECONNRESET error now. Otherwise,
* process the received data and return ENOTCONN the
* next time that psock_recvfrom() is calle.
*/
return ret;
}
}
else
{
ndbg("ERROR: Failed to read packet: %d\n", ret);
return ret;
}
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: psock_recvfrom
*
* Description:
* recvfrom() receives messages from a local 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.
*
* Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* buf Buffer to receive data
* len Length of buffer
* flags Receive flags
* from Address of source (may be NULL)
* fromlen The length of the address structure
*
* Returned Value:
* On success, returns the number of characters sent. If no data is
* available to be received and the peer has performed an orderly shutdown,
* recv() will return 0. Otherwise, on errors, -1 is returned, and errno
* is set appropriately (see receive from for the complete list).
*
****************************************************************************/
ssize_t psock_local_recvfrom(FAR struct socket *psock, FAR void *buf,
size_t len, int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
FAR struct local_conn_s *conn;
size_t readlen;
int ret;
DEBUGASSERT(psock && psock->s_conn && buf);
conn = (FAR struct local_conn_s *)psock->s_conn;
/* Verify that this is a connected peer socket and that it has opened the
* incoming FIFO for read-only access.
*/
if (conn->lc_state != LOCAL_STATE_CONNECTED ||
conn->lc_infd < 0)
{
ndbg("ERROR: not connected\n");
return -ENOTCONN;
}
/* Are there still bytes in the FIFO from the last packet? */
if (conn->u.peer.lc_remaining == 0)
{
/* No.. Sync to the start of the next packet in the stream and get
* the size of the next packet.
*/
ret = local_sync(conn->lc_infd);
if (ret < 0)
{
ndbg("ERROR: Failed to get packet length: %d\n", ret);
return ret;
}
else if (ret > 0xffff)
{
ndbg("ERROR: Packet is too big: %d\n", ret);
return -E2BIG;
}
conn->u.peer.lc_remaining = (uint16_t)ret;
}
/* Read the packet */
/* REVISIT: Does this make sense if the socket is SOCK_DGRAM? */
readlen = MIN(conn->u.peer.lc_remaining, len);
ret = psock_fifo_read(psock, buf, &readlen);
if (ret < 0)
{
return ret;
}
/* Adjust the number of bytes remaining to be read from the packet */
DEBUGASSERT(readlen <= conn->u.peer.lc_remaining);
conn->u.peer.lc_remaining -= readlen;
/* If this is a SOCK_STREAM socket and there are unread bytes remaining
* in the packet, we will get those bytes the next time recv is called.
* What if this is a SOCK_DRAM? REVISIT: Here we flush the remainder of
* the packet to the bit bucket.
*/
if (psock->s_type == SOCK_DGRAM && conn->u.peer.lc_remaining > 0)
{
uint8_t bitbucket[32];
size_t tmplen;
do
{
/* Read 32 bytes into the bit bucket */
tmplen = MIN(conn->u.peer.lc_remaining, 32);
ret = psock_fifo_read(psock, bitbucket, &tmplen);
if (ret < 0)
{
return ret;
}
/* Adjust the number of bytes remaining to be read from the packet */
DEBUGASSERT(tmplen <= conn->u.peer.lc_remaining);
conn->u.peer.lc_remaining -= tmplen;
}
while (conn->u.peer.lc_remaining > 0);
}
/* Return the address family */
if (from)
{
ret = local_getaddr(conn, from, fromlen);
if (ret < 0)
{
return ret;
}
}
return readlen;
}
#endif /* CONFIG_NET && CONFIG_NET_LOCAL */