/****************************************************************************
* net/icmp/icmp_recvmsg.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 <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include <nuttx/net/icmp.h>
#include "devif/devif.h"
#include "socket/socket.h"
#include "icmp/icmp.h"
#ifdef CONFIG_NET_ICMP_SOCKET
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define ICMPBUF ((FAR struct icmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN])
#define ICMPSIZE ((dev)->d_len - IPv4_HDRLEN)
/****************************************************************************
* Private Types
****************************************************************************/
struct icmp_recvfrom_s
{
FAR struct devif_callback_s *recv_cb; /* Reference to callback instance */
FAR struct socket *recv_sock; /* IPPROTO_ICMP socket structure */
sem_t recv_sem; /* Use to manage the wait for the
* response */
in_addr_t recv_from; /* The peer we received the request
* from */
FAR uint8_t *recv_buf; /* Location to return the response */
uint16_t recv_buflen; /* Size of the response */
int16_t recv_result; /* >=0: receive size on success;
* <0: negated errno on fail */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: recvfrom_eventhandler
*
* Description:
* This function is called with the network locked to perform the actual
* ECHO request and/or ECHO reply actions when polled by the lower, device
* interfacing layer.
*
* Input Parameters:
* dev The structure of the network driver that generated the
* event.
* conn The received packet, cast to (void *)
* pvpriv An instance of struct icmp_recvfrom_s cast to void*
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* Modified value of the input flags
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static uint16_t recvfrom_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvconn,
FAR void *pvpriv, uint16_t flags)
{
FAR struct icmp_recvfrom_s *pstate = (struct icmp_recvfrom_s *)pvpriv;
FAR struct socket *psock;
FAR struct icmp_conn_s *conn;
FAR struct ipv4_hdr_s *ipv4;
FAR struct icmp_hdr_s *icmp;
ninfo("flags: %04x\n", flags);
if (pstate != NULL)
{
/* Check if the network is still up */
if ((flags & NETDEV_DOWN) != 0)
{
nerr("ERROR: Interface is down\n");
pstate->recv_result = -ENETUNREACH;
goto end_wait;
}
/* Is this a response on the same device that we sent the request out
* on?
*/
psock = pstate->recv_sock;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
conn = psock->s_conn;
if (dev != conn->dev)
{
ninfo("Wrong device\n");
return flags;
}
/* Check if we have just received a ICMP ECHO reply. */
if ((flags & ICMP_NEWDATA) != 0) /* No incoming data */
{
unsigned int recvsize;
/* Check if it is for us */
icmp = ICMPBUF;
if (conn->id != icmp->id)
{
ninfo("Wrong ID: %u vs %u\n", icmp->id, conn->id);
return flags;
}
ninfo("Received ICMP reply\n");
/* What should we do if the received reply is larger that the
* buffer that the caller of sendto provided? Truncate? Error
* out?
*/
recvsize = ICMPSIZE;
if (recvsize > pstate->recv_buflen)
{
recvsize = pstate->recv_buflen;
}
/* Copy the ICMP ECHO reply to the user provided buffer */
memcpy(pstate->recv_buf, ICMPBUF, recvsize);
/* Return the size of the returned data */
DEBUGASSERT(recvsize <= INT16_MAX);
pstate->recv_result = recvsize;
/* Return the IPv4 address of the sender from the IPv4 header */
ipv4 = IPv4BUF;
net_ipv4addr_hdrcopy(&pstate->recv_from, ipv4->srcipaddr);
/* Decrement the count of outstanding requests. I suppose this
* could have already been decremented of there were multiple
* threads calling sendto() or recvfrom(). If there finds, we
* may have to beef up the design.
*/
DEBUGASSERT(conn->nreqs > 0);
conn->nreqs--;
/* Indicate that the data has been consumed */
flags &= ~ICMP_NEWDATA;
dev->d_len = 0;
goto end_wait;
}
/* Continue waiting */
}
return flags;
end_wait:
ninfo("Resuming\n");
/* Do not allow any further callbacks */
pstate->recv_cb->flags = 0;
pstate->recv_cb->priv = NULL;
pstate->recv_cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->recv_sem);
return flags;
}
/****************************************************************************
* Name: icmp_readahead
*
* Description:
* Copy the buffered read-ahead data to the user buffer.
*
* Input Parameters:
* conn - IPPROTO_ICMP socket connection structure containing the read-
* ahead data.
* dev The structure of the network driver that generated the event.
* pstate recvfrom state structure
*
* Returned Value:
* Number of bytes copied to the user buffer
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static inline ssize_t icmp_readahead(FAR struct icmp_conn_s *conn,
FAR void *buf, size_t buflen,
FAR struct sockaddr_in *from,
FAR socklen_t *fromlen)
{
FAR struct sockaddr_in bitbucket;
FAR struct iob_s *iob;
ssize_t ret = -ENODATA;
int recvlen;
/* Check there is any ICMP replies already buffered in a read-ahead
* buffer.
*/
if ((iob = iob_peek_queue(&conn->readahead)) != NULL)
{
FAR struct iob_s *tmp;
uint16_t offset;
uint8_t addrsize;
DEBUGASSERT(iob->io_pktlen > 0);
/* Transfer that buffered data from the I/O buffer chain into
* the user buffer.
*/
/* First get the size of the address */
recvlen = iob_copyout(&addrsize, iob, sizeof(uint8_t), 0);
if (recvlen != sizeof(uint8_t))
{
ret = -EIO;
goto out;
}
offset = sizeof(uint8_t);
if (addrsize > sizeof(struct sockaddr_in))
{
ret = -EINVAL;
goto out;
}
/* Then get address */
if (from == NULL)
{
from = &bitbucket;
}
recvlen = iob_copyout((FAR uint8_t *)from, iob, addrsize, offset);
if (recvlen != addrsize)
{
ret = -EIO;
goto out;
}
if (fromlen != NULL)
{
*fromlen = addrsize;
}
offset += addrsize;
/* And finally, get the buffered data */
ret = (ssize_t)iob_copyout(buf, iob, buflen, offset);
ninfo("Received %ld bytes (of %u)\n", (long)ret, iob->io_pktlen);
out:
/* Remove the I/O buffer chain from the head of the read-ahead
* buffer queue.
*/
tmp = iob_remove_queue(&conn->readahead);
DEBUGASSERT(tmp == iob);
UNUSED(tmp);
/* And free the I/O buffer chain */
iob_free_chain(iob, IOBUSER_NET_SOCK_ICMP);
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_recvmsg
*
* Description:
* Implements the socket recvfrom interface for the case of the AF_INET
* data gram socket with the IPPROTO_ICMP protocol. icmp_recvmsg()
* receives ICMP ECHO replies for the a socket.
*
* If msg_name is not NULL, and the underlying protocol provides the source
* address, this source address is filled in. The argument 'msg_namelen' is
* initialized to the size of the buffer associated with msg_name, 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
*
* 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 icmp_recvmsg(FAR struct socket *psock, FAR struct msghdr *msg,
int flags)
{
FAR void *buf = msg->msg_iov->iov_base;
size_t len = msg->msg_iov->iov_len;
FAR struct sockaddr *from = msg->msg_name;
FAR socklen_t *fromlen = &msg->msg_namelen;
FAR struct sockaddr_in *inaddr;
FAR struct icmp_conn_s *conn;
FAR struct net_driver_s *dev;
struct icmp_recvfrom_s state;
ssize_t ret;
/* Some sanity checks */
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && buf != NULL);
if (len < ICMP_HDRLEN)
{
return -EINVAL;
}
/* If a 'from' address has been provided, verify that it is large
* enough to hold the AF_INET address.
*/
if (from != NULL)
{
if (fromlen == NULL || *fromlen < sizeof(struct sockaddr_in))
{
return -EINVAL;
}
}
net_lock();
/* We cannot receive a response from a device until a request has been
* sent to the devivce.
*/
conn = psock->s_conn;
if (conn->nreqs < 1)
{
ret = -EPROTO;
goto errout;
}
/* Get the device that was used to send the ICMP request. */
dev = conn->dev;
DEBUGASSERT(dev != NULL);
if (dev == NULL)
{
ret = -EPROTO;
goto errout;
}
/* Check if there is buffered read-ahead data for this socket. We may have
* already received the response to previous command.
*/
if (!IOB_QEMPTY(&conn->readahead))
{
ret = icmp_readahead(conn, buf, len,
(FAR struct sockaddr_in *)from, fromlen);
}
else if (_SS_ISNONBLOCK(conn->sconn.s_flags) ||
(flags & MSG_DONTWAIT) != 0)
{
/* Handle non-blocking ICMP sockets */
ret = -EAGAIN;
}
else
{
/* Initialize the state structure */
memset(&state, 0, sizeof(struct icmp_recvfrom_s));
/* This semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
nxsem_init(&state.recv_sem, 0, 0);
nxsem_set_protocol(&state.recv_sem, SEM_PRIO_NONE);
state.recv_sock = psock; /* The IPPROTO_ICMP socket instance */
state.recv_result = -ENOMEM; /* Assume allocation failure */
state.recv_buf = buf; /* Location to return the response */
state.recv_buflen = len; /* Size of the response */
/* Set up the callback */
state.recv_cb = icmp_callback_alloc(dev, conn);
if (state.recv_cb != NULL)
{
state.recv_cb->flags = (ICMP_NEWDATA | NETDEV_DOWN);
state.recv_cb->priv = (FAR void *)&state;
state.recv_cb->event = recvfrom_eventhandler;
/* Wait for either the response to be received or for timeout to
* occur. net_timedwait will also terminate if a signal is
* received.
*/
ret = net_timedwait(&state.recv_sem,
_SO_TIMEOUT(conn->sconn.s_rcvtimeo));
if (ret < 0)
{
state.recv_result = ret;
}
icmp_callback_free(dev, conn, state.recv_cb);
}
/* Return the negated error number in the event of a failure, or the
* number of bytes received on success.
*/
if (state.recv_result < 0)
{
nerr("ERROR: Return error=%d\n", state.recv_result);
ret = state.recv_result;
goto errout;
}
if (from != NULL)
{
inaddr = (FAR struct sockaddr_in *)from;
inaddr->sin_family = AF_INET;
inaddr->sin_port = 0;
net_ipv4addr_copy(inaddr->sin_addr.s_addr, state.recv_from);
}
ret = state.recv_result;
/* If there a no further outstanding requests,
* make sure that the request struct is left pristine.
*/
errout:
if (conn->nreqs < 1)
{
conn->id = 0;
conn->nreqs = 0;
conn->dev = NULL;
iob_free_queue(&conn->readahead, IOBUSER_NET_SOCK_ICMP);
}
}
net_unlock();
return ret;
}
#endif /* CONFIG_NET_ICMP_SOCKET */