glibc/sysdeps/mach/hurd/if_index.c
Martin Sebor 26492c0a14 Annotate additional APIs with GCC attribute access.
This change continues the improvements to compile-time out of bounds
checking by decorating more APIs with either attribute access, or by
explicitly providing the array bound in APIs such as tmpnam() that
expect arrays of some minimum size as arguments.  (The latter feature
is new in GCC 11.)

The only effects of the attribute and/or the array bound is to check
and diagnose calls to the functions that fail to provide a sufficient
number of elements, and the definitions of the functions that access
elements outside the specified bounds.  (There is no interplay with
_FORTIFY_SOURCE here yet.)

Tested with GCC 7 through 11 on x86_64-linux.
2021-05-06 11:01:05 -06:00

202 lines
5.1 KiB
C

/* Find network interface names and index numbers. Hurd version.
Copyright (C) 2000-2021 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 <error.h>
#include <net/if.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/ioctl.h>
#include <hurd/pfinet.h>
/* Return the interface index corresponding to interface IFNAME.
On error, return 0. */
unsigned int
__if_nametoindex (const char *ifname)
{
struct ifreq ifr;
int fd = __opensock ();
if (fd < 0)
return 0;
if (strlen (ifname) >= IFNAMSIZ)
{
__set_errno (ENODEV);
return 0;
}
strncpy (ifr.ifr_name, ifname, IFNAMSIZ);
if (__ioctl (fd, SIOCGIFINDEX, &ifr) < 0)
{
int saved_errno = errno;
__close (fd);
if (saved_errno == EINVAL || saved_errno == ENOTTY)
__set_errno (ENOSYS);
return 0;
}
__close (fd);
return ifr.ifr_ifindex;
}
libc_hidden_def (__if_nametoindex)
weak_alias (__if_nametoindex, if_nametoindex)
libc_hidden_weak (if_nametoindex)
/* Free the structure IFN returned by if_nameindex. */
void
__if_freenameindex (struct if_nameindex *ifn)
{
struct if_nameindex *ptr = ifn;
while (ptr->if_name || ptr->if_index)
{
free (ptr->if_name);
++ptr;
}
free (ifn);
}
libc_hidden_def (__if_freenameindex)
weak_alias (__if_freenameindex, if_freenameindex)
libc_hidden_weak (if_freenameindex)
/* Return an array of if_nameindex structures, one for each network
interface present, plus one indicating the end of the array. On
error, return NULL. */
struct if_nameindex *
__if_nameindex (void)
{
error_t err = 0;
char data[2048];
file_t server;
int fd = __opensock ();
struct ifconf ifc;
unsigned int nifs, i;
struct if_nameindex *idx = NULL;
ifc.ifc_buf = data;
if (fd < 0)
return NULL;
server = _hurd_socket_server (PF_INET, 0);
if (server == MACH_PORT_NULL)
nifs = 0;
else
{
size_t len = sizeof data;
err = __pfinet_siocgifconf (server, -1, &ifc.ifc_buf, &len);
if (err == MACH_SEND_INVALID_DEST || err == MIG_SERVER_DIED)
{
/* On the first use of the socket server during the operation,
allow for the old server port dying. */
server = _hurd_socket_server (PF_INET, 1);
if (server == MACH_PORT_NULL)
goto out;
err = __pfinet_siocgifconf (server, -1, &ifc.ifc_buf, &len);
}
if (err)
goto out;
ifc.ifc_len = len;
nifs = len / sizeof (struct ifreq);
}
idx = malloc ((nifs + 1) * sizeof (struct if_nameindex));
if (idx == NULL)
{
err = ENOBUFS;
goto out;
}
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)
{
unsigned int j;
err = errno;
for (j = 0; j < i; ++j)
free (idx[j].if_name);
free (idx);
idx = NULL;
if (err == EINVAL)
err = ENOSYS;
else if (err == ENOMEM)
err = ENOBUFS;
goto out;
}
idx[i].if_index = ifr->ifr_ifindex;
}
idx[i].if_index = 0;
idx[i].if_name = NULL;
out:
__close (fd);
if (data != ifc.ifc_buf)
__vm_deallocate (__mach_task_self (), (vm_address_t) ifc.ifc_buf,
ifc.ifc_len);
__set_errno (err);
return idx;
}
weak_alias (__if_nameindex, if_nameindex)
libc_hidden_weak (if_nameindex)
/* Store the name of the interface corresponding to index IFINDEX in
IFNAME (which has space for at least IFNAMSIZ characters). Return
IFNAME, or NULL on error. */
char *
__if_indextoname (unsigned int ifindex, char ifname[IF_NAMESIZE])
{
struct ifreq ifr;
int fd = __opensock ();
if (fd < 0)
return NULL;
ifr.ifr_ifindex = ifindex;
if (__ioctl (fd, SIOCGIFNAME, &ifr) < 0)
{
int saved_errno = errno;
__close (fd);
if (saved_errno == EINVAL || saved_errno == ENOTTY)
__set_errno (ENOSYS);
else if (saved_errno == ENODEV)
__set_errno (ENXIO);
return NULL;
}
__close (fd);
return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
}
weak_alias (__if_indextoname, if_indextoname)
libc_hidden_weak (if_indextoname)
#if 0
void
__protocol_available (int *have_inet, int *have_inet6)
{
*have_inet = _hurd_socket_server (PF_INET, 0) != MACH_PORT_NULL;
*have_inet6 = _hurd_socket_server (PF_INET6, 0) != MACH_PORT_NULL;
}
#endif