Permalink
Cannot retrieve contributors at this time
Name already in use
A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
glibc/sysdeps/unix/sysv/linux/check_pf.c
Go to fileThis commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
193 lines (159 sloc)
4.66 KB
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/* 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 <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 "kernel-features.h" | |
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 | |
} |