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/if_index.c
Go to fileThis commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
241 lines (196 sloc)
5.54 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
/* Copyright (C) 1997-2016 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) |