glibc/support/support_enter_network_namespace.c
Paul Eggert 2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00

76 lines
2.2 KiB
C

/* Enter a network namespace.
Copyright (C) 2016-2021 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, see
<https://www.gnu.org/licenses/>. */
#include <support/namespace.h>
#include <net/if.h>
#include <sched.h>
#include <stdio.h>
#include <string.h>
#include <support/check.h>
#include <support/xsocket.h>
#include <support/xunistd.h>
#include <sys/ioctl.h>
#include <unistd.h>
static bool in_uts_namespace;
bool
support_enter_network_namespace (void)
{
#ifdef CLONE_NEWUTS
if (unshare (CLONE_NEWUTS) == 0)
in_uts_namespace = true;
else
printf ("warning: unshare (CLONE_NEWUTS) failed: %m\n");
#endif
#ifdef CLONE_NEWNET
if (unshare (CLONE_NEWNET) == 0)
{
/* Bring up the loopback interface. */
int fd = xsocket (AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
struct ifreq req;
strcpy (req.ifr_name, "lo");
TEST_VERIFY_EXIT (ioctl (fd, SIOCGIFFLAGS, &req) == 0);
bool already_up = req.ifr_flags & IFF_UP;
if (already_up)
/* This means that we likely have not achieved isolation from
the parent namespace. */
printf ("warning: loopback interface already exists"
" in new network namespace\n");
else
{
req.ifr_flags |= IFF_UP | IFF_RUNNING;
TEST_VERIFY_EXIT (ioctl (fd, SIOCSIFFLAGS, &req) == 0);
}
xclose (fd);
return !already_up;
}
#endif
printf ("warning: could not enter network namespace\n");
return false;
}
bool
support_in_uts_namespace (void)
{
return in_uts_namespace;
}