1/*
2 * get_myaddress.c
3 *
4 * Get client's IP address via ioctl. This avoids using the yellowpages.
5 * Copyright (c) 2010, Oracle America, Inc.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials
16 * provided with the distribution.
17 * * Neither the name of the "Oracle America, Inc." nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
26 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
28 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#include <rpc/types.h>
36#include <rpc/clnt.h>
37#include <rpc/pmap_prot.h>
38#include <sys/socket.h>
39#include <stdio.h>
40#include <unistd.h>
41#include <libintl.h>
42#include <net/if.h>
43#include <ifaddrs.h>
44#include <sys/ioctl.h>
45#include <netinet/in.h>
46#include <arpa/inet.h>
47#include <shlib-compat.h>
48
49/*
50 * don't use gethostbyname, which would invoke yellow pages
51 *
52 * Avoid loopback interfaces. We return information from a loopback
53 * interface only if there are no other possible interfaces.
54 */
55void
56get_myaddress (struct sockaddr_in *addr)
57{
58 struct ifaddrs *ifa;
59
60 if (getifaddrs (&ifa) != 0)
61 {
62 perror ("get_myaddress: getifaddrs");
63 exit (1);
64 }
65
66 int loopback = 0;
67 struct ifaddrs *run;
68
69 again:
70 run = ifa;
71 while (run != NULL)
72 {
73 if ((run->ifa_flags & IFF_UP)
74 && run->ifa_addr != NULL
75 && run->ifa_addr->sa_family == AF_INET
76 && (!(run->ifa_flags & IFF_LOOPBACK)
77 || (loopback == 1 && (run->ifa_flags & IFF_LOOPBACK))))
78 {
79 *addr = *((struct sockaddr_in *) run->ifa_addr);
80 addr->sin_port = htons (PMAPPORT);
81 goto out;
82 }
83
84 run = run->ifa_next;
85 }
86
87 if (loopback == 0)
88 {
89 loopback = 1;
90 goto again;
91 }
92 out:
93 freeifaddrs (ifa);
94
95 /* The function is horribly specified. It does not return any error
96 if no interface is up. Probably this won't happen (at least
97 loopback is there) but still... */
98}
99#ifdef EXPORT_RPC_SYMBOLS
100libc_hidden_def (get_myaddress)
101#else
102libc_hidden_nolink_sunrpc (get_myaddress, GLIBC_2_0)
103#endif
104