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/* Copyright (C) 1997-2015 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
<http://www.gnu.org/licenses/>. */
#include <alloca.h>
#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 <libc-lock.h>
#include <not-cancel.h>
#include "netlinkaccess.h"
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_not_cancel_no_status (fd);
if (saved_errno == EINVAL)
__set_errno (ENOSYS);
return 0;
}
close_not_cancel_no_status (fd);
return ifr.ifr_ifindex;
#endif
}
libc_hidden_def (__if_nametoindex)
weak_alias (__if_nametoindex, if_nametoindex)
libc_hidden_weak (if_nametoindex)
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)
static struct if_nameindex *
if_nameindex_netlink (void)
{
struct netlink_handle nh = { 0, 0, 0, NULL, NULL };
struct if_nameindex *idx = NULL;
if (__netlink_open (&nh) < 0)
return NULL;
/* Tell the kernel that we wish to get a list of all
active interfaces. Collect all data for every interface. */
if (__netlink_request (&nh, RTM_GETLINK) < 0)
goto exit_free;
/* Count the interfaces. */
unsigned int nifs = 0;
for (struct netlink_res *nlp = nh.nlm_list; nlp; nlp = nlp->next)
{
struct nlmsghdr *nlh;
size_t size = nlp->size;
if (nlp->nlh == NULL)
continue;
/* Walk through all entries we got from the kernel and look, which
message type they contain. */
for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size))
{
/* Check if the message is what we want. */
if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
continue;
if (nlh->nlmsg_type == NLMSG_DONE)
break; /* ok */
if (nlh->nlmsg_type == RTM_NEWLINK)
++nifs;
}
}
idx = malloc ((nifs + 1) * sizeof (struct if_nameindex));
if (idx == NULL)
{
nomem:
__set_errno (ENOBUFS);
goto exit_free;
}
/* Add the interfaces. */
nifs = 0;
for (struct netlink_res *nlp = nh.nlm_list; nlp; nlp = nlp->next)
{
struct nlmsghdr *nlh;
size_t size = nlp->size;
if (nlp->nlh == NULL)
continue;
/* Walk through all entries we got from the kernel and look, which
message type they contain. */
for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size))
{
/* Check if the message is what we want. */
if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
continue;
if (nlh->nlmsg_type == NLMSG_DONE)
break; /* ok */
if (nlh->nlmsg_type == RTM_NEWLINK)
{
struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh);
struct rtattr *rta = IFLA_RTA (ifim);
size_t rtasize = IFLA_PAYLOAD (nlh);
idx[nifs].if_index = ifim->ifi_index;
while (RTA_OK (rta, rtasize))
{
char *rta_data = RTA_DATA (rta);
size_t rta_payload = RTA_PAYLOAD (rta);
if (rta->rta_type == IFLA_IFNAME)
{
idx[nifs].if_name = __strndup (rta_data, rta_payload);
if (idx[nifs].if_name == NULL)
{
idx[nifs].if_index = 0;
__if_freenameindex (idx);
idx = NULL;
goto nomem;
}
break;
}
rta = RTA_NEXT (rta, rtasize);
}
++nifs;
}
}
}
idx[nifs].if_index = 0;
idx[nifs].if_name = NULL;
exit_free:
__netlink_free_handle (&nh);
__netlink_close (&nh);
return idx;
}
struct if_nameindex *
__if_nameindex (void)
{
#ifndef SIOCGIFINDEX
__set_errno (ENOSYS);
return NULL;
#else
struct if_nameindex *result = if_nameindex_netlink ();
return result;
#endif
}
weak_alias (__if_nameindex, if_nameindex)
libc_hidden_weak (if_nameindex)
char *
__if_indextoname (unsigned int ifindex, char *ifname)
{
/* 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;
int status;
fd = __opensock ();
if (fd < 0)
return NULL;
ifr.ifr_ifindex = ifindex;
status = __ioctl (fd, SIOCGIFNAME, &ifr);
close_not_cancel_no_status (fd);
if (status < 0)
{
if (errno == ENODEV)
/* POSIX requires ENXIO. */
__set_errno (ENXIO);
return NULL;
}
else
return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
}
weak_alias (__if_indextoname, if_indextoname)
libc_hidden_weak (if_indextoname)
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