1 /*
2 * dhcpcd - DHCP client daemon
3 * Copyright (c) 2009-2010 Roy Marples <roy@marples.name>
4 * All rights reserved
5
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 /*
29 * THIS IS A NASTY HACK THAT SHOULD NEVER HAVE HAPPENED
30 * Basically we cannot include linux/if.h and net/if.h because
31 * they have conflicting structures.
32 * Sadly, linux/wireless.h includes linux/if.h all the time.
33 * Some kernel-header installs fix this and some do not.
34 * This file solely exists for those who do not.
35 *
36 * We *could* include wireless.h as that is designed for userspace,
37 * but that then depends on the correct version of wireless-tools being
38 * installed which isn't always the case.
39 */
40
41 #include <sys/ioctl.h>
42 #include <sys/socket.h>
43
44 #include <linux/types.h>
45 #include <linux/rtnetlink.h>
46 /* Support older kernels */
47 #ifdef IFLA_WIRELESS
48 # include <linux/if.h>
49 # include <linux/wireless.h>
50 #else
51 # define IFLA_WIRELESS (IFLA_MASTER + 1)
52 #endif
53
54 #include <string.h>
55 #include <unistd.h>
56
57 #include "common.h"
58
59 /* We can't include net.h or dhcpcd.h because
60 * they would pull in net/if.h, which defeats the purpose of this hack. */
61 #define IF_SSIDSIZE 33
62 int getifssid(const char *ifname, char *ssid);
63
64 int
getifssid(const char * ifname,char * ssid)65 getifssid(const char *ifname, char *ssid)
66 {
67 #ifdef SIOCGIWESSID
68 int s, retval;
69 struct iwreq iwr;
70
71 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
72 return -1;
73 memset(&iwr, 0, sizeof(iwr));
74 strlcpy(iwr.ifr_name, ifname, sizeof(iwr.ifr_name));
75 iwr.u.essid.pointer = ssid;
76 iwr.u.essid.length = IF_SSIDSIZE - 1;
77
78 if (ioctl(s, SIOCGIWESSID, &iwr) == 0) {
79 retval = iwr.u.essid.length;
80 ssid[retval] = '\0';
81 } else
82 retval = -1;
83 close(s);
84 return retval;
85 #else
86 /* Stop gcc warning about unused paramters */
87 ifname = ssid;
88 return -1;
89 #endif
90 }
91