282 lines
8.8 KiB
C
282 lines
8.8 KiB
C
/****************************************************************************
|
|
* apps/netutils/netlib/netlib_ipv4adaptor.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. The name of the author may not be used to endorse or promote
|
|
* products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/socket.h>
|
|
#include <sys/ioctl.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
|
|
#include <net/if.h>
|
|
#include <nuttx/net/ip.h>
|
|
|
|
#include "netutils/netlib.h"
|
|
|
|
#ifdef CONFIG_NET_IPv4
|
|
|
|
/****************************************************************************
|
|
* Priver Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: _netlib_ipv4adaptor
|
|
*
|
|
* Description:
|
|
* Given the destination address, destipaddr, return the IP address
|
|
* assigned to the network adaptor that connects the sub-net that
|
|
* includes destipaddr.
|
|
*
|
|
* NOTE: This does not account for any routing information that may
|
|
* appear in the routing table. A complete solution could involve three
|
|
* steps:
|
|
*
|
|
* 1. Call netlib_ipv4adaptor() to find the address of the network
|
|
* adaptor for the destination address.
|
|
* 2. If this fails, then look up the router address in the routing table
|
|
* that can forward to the destination address, then
|
|
* 3. Call netlib_ipv4adaptor() to find the address of the network
|
|
* adaptor for that router address.
|
|
*
|
|
* Input Parameters:
|
|
* destipaddr - The destination IPv4 address
|
|
* srcipaddr - The location to return that adaptor address that serves
|
|
* the sub-net that includes the destination address.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) is returned on success with srcipaddr valid. A negated
|
|
* errno value is returned on any failure and in this case the srcipaddr
|
|
* is not valid.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int _netlib_ipv4adaptor(in_addr_t destipaddr,
|
|
FAR in_addr_t *srcipaddr)
|
|
{
|
|
FAR struct ifreq *ifr;
|
|
struct ifconf ifc;
|
|
size_t allocsize;
|
|
size_t buflen;
|
|
int nintf;
|
|
int ret;
|
|
int sd;
|
|
int i;
|
|
|
|
/* REVISIT: Should check the routing table to see if there is a route
|
|
* for the destipaddr before finding the device that provides the sub-net.
|
|
*/
|
|
|
|
/* Find the size of the buffer we need to hold the interface descriptions */
|
|
|
|
ifc.ifc_req = NULL;
|
|
ifc.ifc_len = 0;
|
|
|
|
sd = socket(AF_INET, NETLIB_SOCK_TYPE, 0);
|
|
if (sd < 0)
|
|
{
|
|
ret = -errno;
|
|
fprintf(stderr, "ERROR: socket() failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = ioctl(sd, SIOCGIFCONF, (unsigned long)((uintptr_t)&ifc));
|
|
if (ret < 0)
|
|
{
|
|
ret = -errno;
|
|
fprintf(stderr, "ERROR: ioctl(SIOCGIFCONF) failed: %d\n", ret);
|
|
goto errout_with_sd;
|
|
}
|
|
|
|
/* Allocate the buffer to hold the interface descriptions */
|
|
|
|
allocsize = ifc.ifc_len;
|
|
ifr = (FAR struct ifreq *)malloc(allocsize);
|
|
if (ifr == NULL)
|
|
{
|
|
fprintf(stderr, "ERROR: Failed to allocate IFC buffer\n");
|
|
ret = -ENOMEM;
|
|
goto errout_with_sd;
|
|
}
|
|
|
|
/* Get the interface descriptions */
|
|
|
|
ifc.ifc_req = ifr;
|
|
|
|
ret = ioctl(sd, SIOCGIFCONF, (unsigned long)((uintptr_t)&ifc));
|
|
if (ret < 0)
|
|
{
|
|
ret = -errno;
|
|
fprintf(stderr, "ERROR: ioctl(SIOCGIFCONF) failed: %d\n", ret);
|
|
goto errout_with_ifr;
|
|
}
|
|
|
|
/* Find an interface that supports the subnet needed by the provided
|
|
* IPv4 address. Be careful! The size of the returned buffer could
|
|
* be different if the network device configuration changed in between
|
|
* the two calls!
|
|
*/
|
|
|
|
buflen = ifc.ifc_len;
|
|
if (buflen > allocsize)
|
|
{
|
|
/* Something has changed. Limit to the original size (OR do the
|
|
* allocation and IOCTL again).
|
|
*/
|
|
|
|
buflen = allocsize;
|
|
}
|
|
|
|
nintf = buflen / sizeof(struct ifreq);
|
|
ret = -EHOSTUNREACH;
|
|
|
|
for (i = 0; i < nintf; i++)
|
|
{
|
|
FAR struct ifreq *req = &ifr[i];
|
|
FAR struct sockaddr_in *addr =
|
|
(FAR struct sockaddr_in *)&req->ifr_addr;
|
|
struct ifreq maskreq;
|
|
FAR struct sockaddr_in *netmask;
|
|
|
|
/* Get the network mask */
|
|
|
|
strncpy(maskreq.ifr_name, ifr->ifr_name, IFNAMSIZ);
|
|
|
|
ret = ioctl(sd, SIOCGIFNETMASK, (unsigned long)((uintptr_t)&maskreq));
|
|
if (ret < 0)
|
|
{
|
|
ret = -errno;
|
|
fprintf(stderr, "ERROR: ioctl(SIOCGIFNETMASK) failed: %d\n",
|
|
ret);
|
|
goto errout_with_ifr;
|
|
}
|
|
|
|
netmask = (FAR struct sockaddr_in *)&maskreq.ifr_addr;
|
|
|
|
/* Does this device provide the sub-net? */
|
|
|
|
if (net_ipv4addr_maskcmp(addr->sin_addr.s_addr, destipaddr,
|
|
netmask->sin_addr.s_addr))
|
|
{
|
|
/* Yes.. return the IP address assigned to this adaptor */
|
|
|
|
*srcipaddr = addr->sin_addr.s_addr;
|
|
ret = OK;
|
|
break;
|
|
}
|
|
}
|
|
|
|
errout_with_ifr:
|
|
free(ifr);
|
|
|
|
errout_with_sd:
|
|
close(sd);
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: netlib_ipv4adaptor
|
|
*
|
|
* Description:
|
|
* Given the destination address, destipaddr, return the IP address
|
|
* assigned to the network adaptor that connects the sub-net that
|
|
* includes destipaddr.
|
|
*
|
|
* If routing table support is enabled, then this logic will account for
|
|
* the case where the destination address is not locally accessible. In
|
|
* this case, it will return the IP address of the network adaptor that
|
|
* provides the correct router to handle that destination address.
|
|
*
|
|
* Input Parameters:
|
|
* destipaddr - The destination IPv4 address
|
|
* srcipaddr - The location to return that adaptor address that serves
|
|
* the sub-net that includes the destination address.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) is returned on success with srcipaddr valid. A negated
|
|
* errno value is returned on any failure and in this case the srcipaddr
|
|
* is not valid.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int netlib_ipv4adaptor(in_addr_t destipaddr, FAR in_addr_t *srcipaddr)
|
|
{
|
|
int ret;
|
|
|
|
DEBUGASSERT(srcipaddr != NULL);
|
|
ret = _netlib_ipv4adaptor(destipaddr, srcipaddr);
|
|
|
|
#ifdef HAVE_ROUTE_PROCFS
|
|
if (ret < 0)
|
|
{
|
|
struct in_addr router;
|
|
struct in_addr destinaddr;
|
|
|
|
/* If the first adaptor look-up on the the destination IP address
|
|
* failed, then the IP address cannot be sent on any of the currently
|
|
* up network devices configured with an IPv4 address.
|
|
*
|
|
* But perhaps the destination address is on a sub-net that is
|
|
* accessible on a router that can be reached through a local network
|
|
* adaptor?
|
|
*/
|
|
|
|
destinaddr.s_addr = destipaddr;
|
|
ret = netlib_ipv4router(&destinaddr, &router);
|
|
if (ret >= 0)
|
|
{
|
|
/* Yes... try again using the router address as the destination
|
|
* address.
|
|
*/
|
|
|
|
ret = _netlib_ipv4adaptor(router.s_addr, srcipaddr);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_NET_IPv4 */
|