| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <string.h> |
| #include <unistd.h> |
| #include <linux/sockios.h> |
| #include <net/if.h> |
| #include <sys/socket.h> |
| #include <sys/ioctl.h> |
| |
| /* |
| * Map an interface name into its corresponding index. |
| * Returns 0 on error, as 0 is not a valid index. |
| */ |
| unsigned int if_nametoindex(const char *ifname) |
| { |
| int index; |
| int ctl_sock; |
| struct ifreq ifr; |
| |
| memset(&ifr, 0, sizeof(struct ifreq)); |
| strncpy(ifr.ifr_name, ifname, IFNAMSIZ); |
| ifr.ifr_name[IFNAMSIZ - 1] = 0; |
| |
| index = 0; |
| if ((ctl_sock = socket(AF_INET, SOCK_DGRAM, 0)) >= 0) { |
| if (ioctl(ctl_sock, SIOCGIFINDEX, &ifr) >= 0) { |
| index = ifr.ifr_ifindex; |
| } |
| close(ctl_sock); |
| } |
| return index; |
| } |