glibc/sysdeps/unix/sysv/linux/if_index.c
Ulrich Drepper 263456bdd4 Update.
1999-06-07  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* sysdeps/unix/sysv/linux/if_index.c: Use SIGIOCGIFINDEX and fix
	another SIOGIFNAME typo.

1999-06-07  Ulrich Drepper  <drepper@cygnus.com>

	* elf/dl-lookup.c: Remove duplicated assert.h inclusion.

	* sysdeps/generic/printf_fphex.c (__printf_fphex): Optimize a little
	bit.

1999-06-05  Andreas Schwab  <schwab@issan.cs.uni-dortmund.de>

	* sysdeps/generic/printf_fphex.c (__printf_fphex): Don't ignore
	the precision if the mantissa is zero.

1999-06-05  Andreas Schwab  <schwab@issan.cs.uni-dortmund.de>

	* manual/lang.texi (Floating Point Parameters): GCC already
	supports long double for a long time.

1999-06-05  Andreas Schwab  <schwab@issan.cs.uni-dortmund.de>

	* math/libm-test.c (j0_test, j1_test, jn_test, y0_test, y1_test,
	yn_test): Increase some epsilons.
1999-06-07 15:57:26 +00:00

280 lines
6.0 KiB
C

/* Copyright (C) 1997, 1998, 1999 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <bits/libc-lock.h>
#include "kernel-features.h"
/* Try to get a socket to talk to the kernel. */
#if defined SIOCGIFINDEX || defined SIOCGIFNAME
static int
internal_function
opensock (void)
{
/* Cache the last AF that worked, to avoid many redundant calls to
socket(). */
static int sock_af = -1;
int fd = -1;
__libc_lock_define_initialized (static, lock);
if (sock_af != -1)
{
fd = __socket (sock_af, SOCK_DGRAM, 0);
if (fd != -1)
return fd;
}
__libc_lock_lock (lock);
if (sock_af != -1)
fd = __socket (sock_af, SOCK_DGRAM, 0);
if (fd == -1)
{
fd = __socket (sock_af = AF_INET6, SOCK_DGRAM, 0);
if (fd < 0)
fd = __socket (sock_af = AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
fd = __socket (sock_af = AF_IPX, SOCK_DGRAM, 0);
if (fd < 0)
fd = __socket (sock_af = AF_AX25, SOCK_DGRAM, 0);
if (fd < 0)
fd = __socket (sock_af = AF_APPLETALK, SOCK_DGRAM, 0);
}
__libc_lock_unlock (lock);
return fd;
}
#endif
unsigned int
if_nametoindex (const char *ifname)
{
#ifndef SIOCGIFINDEX
__set_errno (ENOSYS);
return 0;
#else
struct ifreq ifr;
int fd = opensock ();
if (fd < 0)
return 0;
strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
if (__ioctl (fd, SIOCGIFINDEX, &ifr) < 0)
{
int saved_errno = errno;
__close (fd);
if (saved_errno == EINVAL)
__set_errno (ENOSYS);
return 0;
}
__close (fd);
return ifr.ifr_ifindex;
#endif
}
void
if_freenameindex (struct if_nameindex *ifn)
{
struct if_nameindex *ptr = ifn;
while (ptr->if_name || ptr->if_index)
{
if (ptr->if_name)
free (ptr->if_name);
++ptr;
}
free (ifn);
}
struct if_nameindex *
if_nameindex (void)
{
#ifndef SIOCGIFINDEX
__set_errno (ENOSYS);
return NULL;
#else
int fd = opensock ();
struct ifconf ifc;
unsigned int nifs, i;
int rq_len;
struct if_nameindex *idx = NULL;
# if __ASSUME_SIOCGIFNAME == 0
static int old_siocgifconf;
# else
# define old_siocgifconf 0
# endif
# define RQ_IFS 4
if (fd < 0)
return NULL;
ifc.ifc_buf = NULL;
/* We may be able to get the needed buffer size directly, rather than
guessing. */
if (! old_siocgifconf)
{
ifc.ifc_buf = NULL;
ifc.ifc_len = 0;
if (__ioctl (fd, SIOCGIFCONF, &ifc) < 0 || ifc.ifc_len == 0)
{
# if __ASSUME_SIOCGIFNAME == 0
old_siocgifconf = 1;
# endif
rq_len = RQ_IFS * sizeof (struct ifreq);
}
else
rq_len = ifc.ifc_len;
}
else
rq_len = RQ_IFS * sizeof (struct ifreq);
/* Read all the interfaces out of the kernel. */
do
{
ifc.ifc_buf = alloca (ifc.ifc_len = rq_len);
if (ifc.ifc_buf == NULL || __ioctl (fd, SIOCGIFCONF, &ifc) < 0)
{
__close (fd);
return NULL;
}
rq_len *= 2;
}
while (ifc.ifc_len == rq_len && old_siocgifconf);
nifs = ifc.ifc_len / sizeof (struct ifreq);
idx = malloc ((nifs + 1) * sizeof (struct if_nameindex));
if (idx == NULL)
{
__close (fd);
return NULL;
}
for (i = 0; i < nifs; ++i)
{
struct ifreq *ifr = &ifc.ifc_req[i];
idx[i].if_name = __strdup (ifr->ifr_name);
if (idx[i].if_name == NULL
|| __ioctl (fd, SIOCGIFINDEX, ifr) < 0)
{
int saved_errno = errno;
unsigned int j;
for (j = 0; j < i; ++j)
free (idx[j].if_name);
free (idx);
__close (fd);
if (saved_errno == EINVAL)
__set_errno (ENOSYS);
return NULL;
}
idx[i].if_index = ifr->ifr_ifindex;
}
idx[i].if_index = 0;
idx[i].if_name = NULL;
__close (fd);
return idx;
#endif
}
char *
if_indextoname (unsigned int ifindex, char *ifname)
{
#if !defined SIOCGIFINDEX && __ASSUME_SIOCGIFNAME == 0
__set_errno (ENOSYS);
return NULL;
#else
# if __ASSUME_SIOCGIFNAME == 0
struct if_nameindex *idx;
struct if_nameindex *p;
char *result = NULL;
# endif
# if defined SIOCGIFNAME || __ASSUME_SIOCGIFNAME > 0
/* We may be able to do the conversion directly, rather than searching a
list. This ioctl is not present in kernels before version 2.1.50. */
struct ifreq ifr;
int fd;
# if __ASSUME_SIOCGIFNAME == 0
static int siocgifname_works_not;
if (!siocgifname_works_not)
# endif
{
# if __ASSUME_SIOCGIFNAME == 0
int serrno = errno;
# endif
int status;
fd = opensock ();
if (fd < 0)
return NULL;
ifr.ifr_ifindex = ifindex;
status = __ioctl (fd, SIOCGIFNAME, &ifr);
__close (fd);
# if __ASSUME_SIOCGIFNAME == 0
if (status < 0)
{
if (errno == EINVAL)
siocgifname_works_not = 1; /* Don't make the same mistake twice. */
}
else
return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
__set_errno (serrno);
# else
return status < 0 ? NULL : strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
# endif
}
# endif
# if __ASSUME_SIOCGIFNAME == 0
idx = if_nameindex ();
if (idx != NULL)
{
for (p = idx; p->if_index || p->if_name; ++p)
if (p->if_index == ifindex)
{
result = strncpy (ifname, p->if_name, IFNAMSIZ);
break;
}
if_freenameindex (idx);
}
return result;
# endif
#endif
}