1 /* @(#)get_myaddress.c 2.1 88/07/29 4.0 RPCSRC */
2 /*
3 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4 * unrestricted use provided that this legend is included on all tape
5 * media and as a part of the software program in whole or part. Users
6 * may copy or modify Sun RPC without charge, but are not authorized
7 * to license or distribute it to anyone else except as part of a product or
8 * program developed by the user.
9 *
10 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13 *
14 * Sun RPC is provided with no support and without any obligation on the
15 * part of Sun Microsystems, Inc. to assist in its use, correction,
16 * modification or enhancement.
17 *
18 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20 * OR ANY PART THEREOF.
21 *
22 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23 * or profits or other special, indirect and consequential damages, even if
24 * Sun has been advised of the possibility of such damages.
25 *
26 * Sun Microsystems, Inc.
27 * 2550 Garcia Avenue
28 * Mountain View, California 94043
29 */
30 #if 0
31 static char sccsid[] = "@(#)get_myaddress.c 1.4 87/08/11 Copyr 1984 Sun Micro";
32 #endif
33
34 /*
35 * get_myaddress.c
36 *
37 * Get client's IP address via ioctl. This avoids using the yellowpages.
38 * Copyright (C) 1984, Sun Microsystems, Inc.
39 */
40
41 #include <rpc/types.h>
42 #include <rpc/clnt.h>
43 #include <rpc/pmap_prot.h>
44 #include <sys/socket.h>
45 #include <stdio.h>
46 #include <unistd.h>
47 #include <libintl.h>
48 #include <net/if.h>
49 #include <sys/ioctl.h>
50 /* Order of following two #includes reversed by roland@gnu */
51 #include <netinet/in.h>
52 #include <arpa/inet.h>
53
54
55 /*
56 * don't use gethostbyname, which would invoke yellow pages
57 *
58 * Avoid loopback interfaces. We return information from a loopback
59 * interface only if there are no other possible interfaces.
60 */
61 void
get_myaddress(struct sockaddr_in * addr)62 get_myaddress (struct sockaddr_in *addr)
63 {
64 int s;
65 char buf[BUFSIZ];
66 struct ifconf ifc;
67 struct ifreq ifreq, *ifr;
68 int len, loopback = 0;
69
70 if ((s = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
71 {
72 perror ("get_myaddress: socket");
73 exit (1);
74 }
75 ifc.ifc_len = sizeof (buf);
76 ifc.ifc_buf = buf;
77 if (ioctl (s, SIOCGIFCONF, (char *) &ifc) < 0)
78 {
79 perror (_("get_myaddress: ioctl (get interface configuration)"));
80 exit (1);
81 }
82
83 again:
84 ifr = ifc.ifc_req;
85 for (len = ifc.ifc_len; len; len -= sizeof ifreq)
86 {
87 ifreq = *ifr;
88 if (ioctl (s, SIOCGIFFLAGS, (char *) &ifreq) < 0)
89 {
90 perror ("get_myaddress: ioctl");
91 exit (1);
92 }
93 if ((ifreq.ifr_flags & IFF_UP) && (ifr->ifr_addr.sa_family == AF_INET)
94 && (!(ifreq.ifr_flags & IFF_LOOPBACK) ||
95 (loopback == 1 && (ifreq.ifr_flags & IFF_LOOPBACK))))
96 {
97 *addr = *((struct sockaddr_in *) &ifr->ifr_addr);
98 addr->sin_port = htons (PMAPPORT);
99 close (s);
100 return;
101 }
102 ifr++;
103 }
104 if (loopback == 0)
105 {
106 loopback = 1;
107 goto again;
108 }
109 close (s);
110 }
111