/****************************************************************************
* net/icmp/icmp_recvfrom.c
*
* Copyright (C) 2017 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>
#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 ((struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define ICMPBUF ((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 */
clock_t recv_time; /* Start time for determining timeouts */
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_timeout
*
* Description:
* Check for send timeout.
*
* Input Parameters:
* pstate - Reference to instance ot recvfrom state structure
*
* Returned Value:
* true: timeout false: no timeout
*
* Assumptions:
* The network is locked
*
****************************************************************************/
#ifdef CONFIG_NET_SOCKOPTS
static inline int recvfrom_timeout(FAR struct icmp_recvfrom_s *pstate)
{
FAR struct socket *psock;
/* Check for a timeout configured via setsockopts(SO_SNDTIMEO).
* If none... we will let the send wait forever.
*/
psock = pstate->recv_sock;
if (psock != NULL && psock->s_rcvtimeo != 0)
{
/* Check if the configured timeout has elapsed */
return net_timeo(pstate->recv_time, psock->s_rcvtimeo);
}
/* No timeout */
return false;
}
#endif /* CONFIG_NET_SOCKOPTS */
/****************************************************************************
* 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_ECHOREPLY) != 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 oustanding 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--;
goto end_wait;
}
#ifdef CONFIG_NET_SOCKOPTS
/* Check if the selected timeout has elapsed */
if (recvfrom_timeout(pstate))
{
nerr("ERROR: recvfrom() timeout\n");
pstate->recv_result = -ETIMEDOUT;
goto end_wait;
}
#endif
/* 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:
* Nunber 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 */
(void)iob_free_chain(iob);
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_recvfrom
*
* Description:
* Implements the socket recvfrom interface for the case of the AF_INET
* data gram socket with the IPPROTO_ICMP protocol. icmp_recvfrom()
* receives ICMP ECHO replies for the a socket.
*
* If 'from' is not NULL, and the underlying protocol provides the source
* address, this source address is filled in. The argument 'fromlen' is
* 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
* 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, a negated errno value is
* returned (see recvfrom() for the list of appropriate error values).
*
****************************************************************************/
ssize_t icmp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
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;
}
}
/* 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;
}
/* Check if there is buffered read-ahead data for this socket. We may have
* already received the reponse to previous command.
*/
if (!IOB_QEMPTY(&conn->readahead))
{
return icmp_readahead(conn, buf, len,
(FAR struct sockaddr_in *)from, fromlen);
}
/* 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_setprotocol(&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 */
net_lock();
state.recv_time = clock_systimer();
/* Get the device that was used to send the ICMP request. */
dev = conn->dev;
DEBUGASSERT(dev != NULL);
if (dev == NULL)
{
ret = -EPROTO;
goto errout;
}
/* Set up the callback */
state.recv_cb = icmp_callback_alloc(dev);
if (state.recv_cb)
{
state.recv_cb->flags = (ICMP_ECHOREPLY | NETDEV_DOWN);
state.recv_cb->priv = (FAR void *)&state;
state.recv_cb->event = recvfrom_eventhandler;
state.recv_result = -EINTR; /* Assume sem-wait interrupted by signal */
/* Wait for either the response to be received or for timeout to
* occur. net_lockedwait will also terminate if a signal is received.
*/
ninfo("Start time: 0x%08x\n", state.recv_time);
net_lockedwait(&state.recv_sem);
icmp_callback_free(dev, state.recv_cb);
}
net_unlock();
/* 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);
}
return ret;
}
#endif /* CONFIG_NET_ICMP_SOCKET */