mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-05 08:51:48 +00:00
200 lines
4.8 KiB
C
200 lines
4.8 KiB
C
/* Determine protocol families for which interfaces exist. Linux version.
|
|
Copyright (C) 2003 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include <stdint.h>
|
|
#include <ifaddrs.h>
|
|
#include <netdb.h>
|
|
#include <string.h>
|
|
#include <time.h>
|
|
#include <unistd.h>
|
|
#include <sys/socket.h>
|
|
|
|
#include <asm/types.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/rtnetlink.h>
|
|
|
|
#include <stdbool.h>
|
|
#include <sys/uio.h>
|
|
|
|
#include "config.h"
|
|
#include "local.h"
|
|
|
|
#define __ASSUME_NETLINK_SUPPORT 1
|
|
|
|
static int
|
|
make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6)
|
|
{
|
|
struct
|
|
{
|
|
struct nlmsghdr nlh;
|
|
struct rtgenmsg g;
|
|
} req;
|
|
struct sockaddr_nl nladdr;
|
|
|
|
req.nlh.nlmsg_len = sizeof (req);
|
|
req.nlh.nlmsg_type = RTM_GETADDR;
|
|
req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
|
|
req.nlh.nlmsg_pid = 0;
|
|
req.nlh.nlmsg_seq = time (NULL);
|
|
req.g.rtgen_family = AF_UNSPEC;
|
|
|
|
memset (&nladdr, '\0', sizeof (nladdr));
|
|
nladdr.nl_family = AF_NETLINK;
|
|
|
|
if (TEMP_FAILURE_RETRY (sendto (fd, (void *) &req, sizeof (req), 0,
|
|
(struct sockaddr *) &nladdr,
|
|
sizeof (nladdr))) < 0)
|
|
return -1;
|
|
|
|
*seen_ipv4 = false;
|
|
*seen_ipv6 = false;
|
|
|
|
bool done = false;
|
|
char buf[4096];
|
|
struct iovec iov = { buf, sizeof (buf) };
|
|
|
|
do
|
|
{
|
|
struct msghdr msg =
|
|
{
|
|
(void *) &nladdr, sizeof (nladdr),
|
|
&iov, 1,
|
|
NULL, 0,
|
|
0
|
|
};
|
|
|
|
ssize_t read_len = TEMP_FAILURE_RETRY (recvmsg (fd, &msg, 0));
|
|
if (read_len < 0)
|
|
return -1;
|
|
|
|
if (msg.msg_flags & MSG_TRUNC)
|
|
return -1;
|
|
|
|
struct nlmsghdr *nlmh;
|
|
for (nlmh = (struct nlmsghdr *) buf;
|
|
NLMSG_OK (nlmh, (size_t) read_len);
|
|
nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, read_len))
|
|
{
|
|
if (nladdr.nl_pid != 0 || (pid_t) nlmh->nlmsg_pid != pid
|
|
|| nlmh->nlmsg_seq != req.nlh.nlmsg_seq)
|
|
continue;
|
|
|
|
if (nlmh->nlmsg_type == RTM_NEWADDR)
|
|
{
|
|
struct ifaddrmsg *ifam = (struct ifaddrmsg *) NLMSG_DATA (nlmh);
|
|
|
|
switch (ifam->ifa_family)
|
|
{
|
|
case AF_INET:
|
|
*seen_ipv4 = true;
|
|
break;
|
|
case AF_INET6:
|
|
*seen_ipv6 = true;
|
|
break;
|
|
default:
|
|
/* Ignore. */
|
|
break;
|
|
}
|
|
}
|
|
else if (nlmh->nlmsg_type == NLMSG_DONE)
|
|
/* We found the end, leave the loop. */
|
|
done = true;
|
|
else ;
|
|
}
|
|
}
|
|
while (! done);
|
|
|
|
close (fd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* We don't know if we have NETLINK support compiled in in our
|
|
Kernel. */
|
|
#if __ASSUME_NETLINK_SUPPORT == 0
|
|
/* Define in ifaddrs.h. */
|
|
extern int __no_netlink_support attribute_hidden;
|
|
#else
|
|
# define __no_netlink_support 0
|
|
#endif
|
|
|
|
|
|
void
|
|
attribute_hidden
|
|
__check_pf (bool *seen_ipv4, bool *seen_ipv6)
|
|
{
|
|
if (! __no_netlink_support)
|
|
{
|
|
int fd = socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
|
|
|
|
struct sockaddr_nl nladdr;
|
|
memset (&nladdr, '\0', sizeof (nladdr));
|
|
nladdr.nl_family = AF_NETLINK;
|
|
|
|
socklen_t addr_len = sizeof (nladdr);
|
|
|
|
if (fd >= 0
|
|
&& bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0
|
|
&& getsockname (fd, (struct sockaddr *) &nladdr, &addr_len) == 0
|
|
&& make_request (fd, nladdr.nl_pid, seen_ipv4, seen_ipv6) == 0)
|
|
/* It worked. */
|
|
return;
|
|
|
|
if (fd >= 0)
|
|
close (fd);
|
|
|
|
#if __ASSUME_NETLINK_SUPPORT == 0
|
|
/* Remember that there is no netlink support. */
|
|
__no_netlink_support = 1;
|
|
#else
|
|
/* We cannot determine what interfaces are available. Be
|
|
pessimistic. */
|
|
*seen_ipv4 = true;
|
|
*seen_ipv6 = true;
|
|
#endif
|
|
}
|
|
|
|
#if __ASSUME_NETLINK_SUPPORT == 0
|
|
/* No netlink. Get the interface list via getifaddrs. */
|
|
struct ifaddrs *ifa = NULL;
|
|
if (getifaddrs (&ifa) != 0)
|
|
{
|
|
/* We cannot determine what interfaces are available. Be
|
|
pessimistic. */
|
|
*seen_ipv4 = true;
|
|
*seen_ipv6 = true;
|
|
return;
|
|
}
|
|
|
|
*seen_ipv4 = false;
|
|
*seen_ipv6 = false;
|
|
|
|
struct ifaddrs *runp;
|
|
for (runp = ifa; runp != NULL; runp = runp->ifa_next)
|
|
if (runp->ifa_addr->sa_family == PF_INET)
|
|
*seen_ipv4 = true;
|
|
else if (runp->ifa_addr->sa_family == PF_INET6)
|
|
*seen_ipv6 = true;
|
|
|
|
(void) freeifaddrs (ifa);
|
|
#endif
|
|
}
|