/****************************************************************************
* net/socket/recvfrom.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>
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <nuttx/cancelpt.h>
#include <nuttx/kmalloc.h>
#include <nuttx/net/net.h>
#include "socket/socket.h"
#ifdef CONFIG_NET
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_recvfrom
*
* Description:
* psock_recvfrom() receives messages from a socket, and may be used to
* receive data on a socket whether or not it is connection-oriented.
* This is an internal OS interface. It is functionally equivalent to
* recvfrom() except that:
*
* - It is not a cancellation point,
* - It does not modify the errno variable, and
* - It accepts the internal socket structure as an input rather than an
* task-specific socket descriptor.
*
* 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,
* psock_recvfrom() will return 0. Otherwise, on any failure, a negated
* errno value is returned (see comments with recvfrom() for a list of
* appropriate errno values).
*
****************************************************************************/
ssize_t psock_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
struct msghdr msg;
struct iovec iov;
ssize_t ret;
iov.iov_base = buf;
iov.iov_len = len;
msg.msg_name = from;
msg.msg_namelen = fromlen ? *fromlen : 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
/* And let psock_recvmsg do all of the work */
ret = psock_recvmsg(psock, &msg, flags);
if (ret >= 0 && fromlen != NULL)
*fromlen = msg.msg_namelen;
return ret;
}
/****************************************************************************
* Name: 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:
* sockfd Socket descriptor of socket
* 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. On error,
* -1 is returned, and errno is set appropriately:
*
* EAGAIN
* The socket is marked non-blocking and the receive operation would
* block, or a receive timeout had been set and the timeout expired
* before data was received.
* EBADF
* The argument sockfd is an invalid descriptor.
* ECONNREFUSED
* A remote host refused to allow the network connection (typically
* because it is not running the requested service).
* EFAULT
* The receive buffer pointer(s) point outside the process's address
* space.
* EINTR
* The receive was interrupted by delivery of a signal before any data
* were available.
* EINVAL
* Invalid argument passed.
* ENOMEM
* Could not allocate memory.
* ENOTCONN
* The socket is associated with a connection-oriented protocol and has
* not been connected.
* ENOTSOCK
* The argument sockfd does not refer to a socket.
*
****************************************************************************/
ssize_t recvfrom(int sockfd, FAR void *buf, size_t len, int flags,
FAR struct sockaddr *from, FAR socklen_t *fromlen)
{
FAR struct socket *psock;
ssize_t ret;
#ifdef CONFIG_BUILD_KERNEL
struct sockaddr_storage kaddr;
FAR struct sockaddr *ufrom;
FAR void *kbuf;
FAR void *ubuf;
#endif
/* recvfrom() is a cancellation point */
enter_cancellation_point();
#ifdef CONFIG_BUILD_KERNEL
/* Allocate memory and copy user buffer to kernel */
kbuf = kmm_malloc(len);
if (!kbuf)
{
/* Out of memory */
ret = -ENOMEM;
goto errout_with_cancelpt;
}
ubuf = buf;
buf = kbuf;
/* Copy the address data to kernel, store the original user pointer */
if ((ufrom = from) != NULL)
{
from = (FAR struct sockaddr *)&kaddr;
}
#endif
/* Get the underlying socket structure */
ret = sockfd_socket(sockfd, &psock);
/* Then let psock_recvfrom() do all of the work */
if (ret == OK)
{
ret = psock_recvfrom(psock, buf, len, flags, from, fromlen);
}
#ifdef CONFIG_BUILD_KERNEL
memcpy(ubuf, buf, len);
kmm_free(kbuf);
/* Copy the address back to user */
if (ufrom)
{
memcpy(ufrom, &kaddr, *fromlen);
}
errout_with_cancelpt:
#endif
leave_cancellation_point();
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}
#endif /* CONFIG_NET */