xref: /openbsd-src/lib/libc/rpc/get_myaddress.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char *rcsid = "$OpenBSD: get_myaddress.c,v 1.10 2000/02/25 05:06:27 itojun Exp $";
32 #endif /* LIBC_SCCS and not lint */
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/xdr.h>
43 #include <rpc/pmap_prot.h>
44 #include <sys/socket.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <net/if.h>
49 #include <netinet/in.h>
50 #include <ifaddrs.h>
51 
52 /*
53  * don't use gethostbyname, which would invoke yellow pages
54  *
55  * Avoid loopback interfaces.  We return information from a loopback
56  * interface only if there are no other possible interfaces.
57  */
58 int
59 get_myaddress(addr)
60 	struct sockaddr_in *addr;
61 {
62 	struct ifaddrs *ifap, *ifa;
63 	int loopback = 0, gotit = 0;
64 
65 	if (getifaddrs(&ifap) != 0)
66 		return (-1);
67 
68   again:
69 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
70 		if ((ifa->ifa_flags & IFF_UP) &&
71 		    ifa->ifa_addr->sa_family == AF_INET &&
72 		    (loopback == 1 && (ifa->ifa_flags & IFF_LOOPBACK))) {
73 			*addr = *((struct sockaddr_in *)ifa->ifa_addr);
74 			addr->sin_port = htons(PMAPPORT);
75 			gotit = 1;
76 			break;
77 		}
78 	}
79 	if (gotit == 0 && loopback == 0) {
80 		loopback = 1;
81 		goto again;
82 	}
83 	freeifaddrs(ifap);
84 	return (0);
85 }
86