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incubator-nuttx/net/local/local_recvmsg.c

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/****************************************************************************
* net/local/local_recvmsg.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <inttypes.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <fcntl.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/net/net.h>
#include "socket/socket.h"
#include "local/local.h"
#include "utils/utils.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: psock_fifo_read
*
* Description:
* A thin layer around local_fifo_read that handles socket-related loss-of-
* connection events.
*
****************************************************************************/
static int psock_fifo_read(FAR struct socket *psock, FAR void *buf,
size_t offset, FAR size_t *readlen,
int flags, bool once)
{
FAR struct local_conn_s *conn = psock->s_conn;
int ret;
if (flags & MSG_PEEK)
{
struct pipe_peek_s peek =
{
buf,
offset,
*readlen
};
ret = file_ioctl(&conn->lc_infile, PIPEIOC_PEEK,
(unsigned long)((uintptr_t)&peek));
}
else
{
ret = local_fifo_read(&conn->lc_infile, buf, readlen, once);
}
if (ret < 0)
{
/* -ECONNRESET is a special case. We may or not have received
* data, then the peer closed the connection.
*/
if (ret == -ECONNRESET)
{
nerr("ERROR: Lost connection: %d\n", ret);
/* Report an ungraceful loss of connection. This should
* eventually be reported as ENOTCONN.
*/
conn->lc_conn.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 called.
*/
return ret;
}
}
else
{
if (ret != -EAGAIN)
{
nerr("ERROR: Failed to read packet: %d\n", ret);
}
return ret;
}
}
return OK;
}
/****************************************************************************
* Name: local_recvctl
*
* Description:
* Handle the socket message conntrol field
*
* Input Parameters:
* conn Local connection instance
* msg Message to send
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_SCM
static void local_recvctl(FAR struct local_conn_s *conn,
FAR struct msghdr *msg, int flags)
{
FAR struct local_conn_s *peer;
int count;
int *fds;
int i;
net_lock();
if (conn->lc_peer == NULL)
{
peer = local_peerconn(conn);
if (peer == NULL)
{
goto out;
}
}
else
{
peer = conn;
}
if (peer->lc_cfpcount == 0)
{
goto out;
}
fds = cmsg_append(msg, SOL_SOCKET, SCM_RIGHTS, NULL,
sizeof(int) * peer->lc_cfpcount);
if (fds == NULL)
{
goto out;
}
count = peer->lc_cfpcount;
for (i = 0; i < count; i++)
{
fds[i] = file_dup(peer->lc_cfps[i], 0,
flags & MSG_CMSG_CLOEXEC ? O_CLOEXEC : 0);
file_close(peer->lc_cfps[i]);
kmm_free(peer->lc_cfps[i]);
peer->lc_cfps[i] = NULL;
peer->lc_cfpcount--;
if (fds[i] < 0)
{
i++;
break;
}
}
if (i > 0)
{
if (peer->lc_cfpcount)
{
memmove(peer->lc_cfps[0], peer->lc_cfps[i],
sizeof(FAR void *) * peer->lc_cfpcount);
}
}
out:
net_unlock();
}
#endif /* CONFIG_NET_LOCAL_SCM */
/****************************************************************************
* Name: psock_stream_recvfrom
*
* Description:
* psock_stream_recvfrom() receives messages from a local stream socket.
*
* Input 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 received. 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).
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_STREAM
static inline ssize_t
psock_stream_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 = psock->s_conn;
size_t readlen = len;
int ret;
/* Verify that this is a connected peer socket */
if (conn->lc_state != LOCAL_STATE_CONNECTED)
{
nerr("ERROR: not connected\n");
return -ENOTCONN;
}
/* Check shutdown state */
if (conn->lc_infile.f_inode == NULL)
{
return 0;
}
/* If it is non-blocking mode, the data in fifo is 0 and
* returns directly
*/
if (flags & MSG_DONTWAIT)
{
int data_len = 0;
ret = file_ioctl(&conn->lc_infile, FIONREAD, &data_len);
if (ret < 0)
{
return ret;
}
if (data_len == 0)
{
return -EAGAIN;
}
}
/* Read the packet */
ret = psock_fifo_read(psock, buf, 0, &readlen, flags, true);
if (ret < 0)
{
return ret;
}
/* Return the address family */
if (from)
{
ret = local_getaddr(conn, from, fromlen);
if (ret < 0)
{
return ret;
}
}
return readlen;
}
#endif /* CONFIG_NET_LOCAL_STREAM */
/****************************************************************************
* Name: psock_fifo_discard
*
* Description:
* psock_fifo_discard() discard buffer from a local socket.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* len Remaining length of buffer
* flags Receive flags
*
* Returned Value:
* On success, returns OK. Otherwise, on errors, errno is returned
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
static int psock_fifo_discard(FAR struct socket *psock, size_t len,
int flags)
{
uint8_t bitbucket[256];
size_t tmplen;
int ret;
if (flags & MSG_PEEK)
{
return OK;
}
while (len > 0)
{
/* Read 256 bytes into the bit bucket */
tmplen = MIN(len, sizeof(bitbucket));
ret = psock_fifo_read(psock, bitbucket, 0, &tmplen, flags, false);
if (ret < 0)
{
nerr("ERROR: Failed to get bitbucket : ret %d\n", ret);
return ret;
}
/* Adjust the number of bytes len to be read from the packet */
DEBUGASSERT(tmplen <= len);
len -= tmplen;
}
return OK;
}
/****************************************************************************
* Name: psock_dgram_recvfrom
*
* Description:
* psock_dgram_recvfrom() receives messages from a local datagram socket.
*
* Input 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 received. Otherwise, on
* errors, -1 is returned, and errno is set appropriately (see receive
* from for the complete list).
*
****************************************************************************/
static inline ssize_t
psock_dgram_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 = psock->s_conn;
size_t readlen;
size_t pathlen;
bool bclose = false;
lc_size_t addrlen;
lc_size_t pktlen;
int offset = 0;
int ret;
/* Verify that this is a bound, un-connected peer socket */
if (conn->lc_state != LOCAL_STATE_BOUND &&
conn->lc_state != LOCAL_STATE_CONNECTED)
{
/* Either not bound to address or it is connected */
nerr("ERROR: Connected or not bound\n");
return -EISCONN;
}
if (conn->lc_infile.f_inode == NULL)
{
bclose = true;
/* Make sure that half duplex FIFO has been created */
ret = local_create_halfduplex(conn, conn->lc_path, conn->lc_rcvsize);
if (ret < 0)
{
nerr("ERROR: Failed to create FIFO for %s: %d\n",
conn->lc_path, ret);
return ret;
}
/* Open the receiving side of the transfer */
ret = local_open_receiver(conn, (flags & MSG_DONTWAIT) != 0 ||
_SS_ISNONBLOCK(conn->lc_conn.s_flags));
if (ret < 0)
{
nerr("ERROR: Failed to open FIFO for %s: %d\n",
conn->lc_path, ret);
goto errout_with_halfduplex;
}
}
readlen = sizeof(addrlen);
ret = psock_fifo_read(psock, &addrlen, offset, &readlen, flags, false);
if (ret < 0)
{
nerr("ERROR: Failed to get path length: ret %d\n", ret);
return ret;
}
/* Sync to the start of the next packet in the stream and get the size of
* the next packet.
*/
readlen = sizeof(pktlen);
offset += sizeof(addrlen);
ret = psock_fifo_read(psock, &pktlen, offset, &readlen, flags, false);
if (ret < 0)
{
nerr("ERROR: Failed to get packet length: ret %d\n", ret);
goto errout_with_infd;
}
readlen = addrlen;
offset += sizeof(pktlen);
if (from && fromlen && *fromlen)
{
pathlen = MIN(*fromlen - 1, readlen);
ret = psock_fifo_read(psock, from->sa_data, offset,
&pathlen, flags, false);
if (ret < 0)
{
nerr("ERROR: Failed to get path : ret %d\n", ret);
goto errout_with_infd;
}
from->sa_family = AF_LOCAL;
from->sa_data[pathlen] = '\0';
*fromlen = pathlen;
readlen -= pathlen;
}
if (readlen)
{
ret = psock_fifo_discard(psock, readlen, flags);
if (ret < 0)
{
nerr("ERROR: Failed to discard redunance address: ret %d\n", ret);
goto errout_with_infd;
}
}
/* Read the packet */
readlen = MIN(pktlen, len);
offset += addrlen;
ret = psock_fifo_read(psock, buf, offset, &readlen, flags, false);
if (ret < 0)
{
nerr("ERROR: Failed to get packet : ret %d\n", ret);
goto errout_with_infd;
}
/* If there are unread bytes remaining in the packet, flush the remainder
* of the packet to the bit bucket.
*/
DEBUGASSERT(readlen <= pktlen);
if (readlen < pktlen)
{
ret = psock_fifo_discard(psock, pktlen - readlen, flags);
}
errout_with_infd:
/* Close the read-only file descriptor */
if (bclose)
{
/* Now we can close the read-only file descriptor */
file_close(&conn->lc_infile);
conn->lc_infile.f_inode = NULL;
errout_with_halfduplex:
/* Release our reference to the half duplex FIFO */
local_release_halfduplex(conn);
}
return ret < 0 ? ret : readlen;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: local_recvmsg
*
* Description:
* recvmsg() 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.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* msg Buffer to receive the message
* flags Receive flags (ignored for now)
*
* Returned Value:
* On success, returns the number of characters received. If no data is
* available to be received and the peer has performed an orderly shutdown,
* recvmsg() will return 0. Otherwise, on errors, a negated errno value is
* returned (see recvmsg() for the list of appropriate error values).
*
****************************************************************************/
ssize_t local_recvmsg(FAR struct socket *psock, FAR struct msghdr *msg,
int flags)
{
FAR struct local_conn_s *conn = psock->s_conn;
FAR socklen_t *fromlen = &msg->msg_namelen;
FAR struct sockaddr *from = msg->msg_name;
FAR void *buf = msg->msg_iov->iov_base;
size_t len = msg->msg_iov->iov_len;
/* Check shutdown state */
if (conn->lc_infile.f_inode == NULL)
{
return 0;
}
DEBUGASSERT(buf);
/* Check for a stream socket */
#ifdef CONFIG_NET_LOCAL_STREAM
if (psock->s_type == SOCK_STREAM)
{
len = psock_stream_recvfrom(psock, buf, len, flags, from, fromlen);
}
else
#endif
#ifdef CONFIG_NET_LOCAL_DGRAM
if (psock->s_type == SOCK_DGRAM)
{
len = psock_dgram_recvfrom(psock, buf, len, flags, from, fromlen);
}
else
#endif
{
DEBUGPANIC();
nerr("ERROR: Unrecognized socket type: %" PRIu8 "\n", psock->s_type);
len = -EINVAL;
}
#ifdef CONFIG_NET_LOCAL_SCM
/* Receive the control message */
if (len >= 0 && msg->msg_control &&
msg->msg_controllen > sizeof(struct cmsghdr))
{
local_recvctl(psock->s_conn, msg, flags);
}
#endif /* CONFIG_NET_LOCAL_SCM */
return len;
}
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