xref: /original-bsd/lib/librpc/rpc/get_myaddress.c (revision 9d1db70c)
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 !defined(lint) && defined(SCCSIDS)
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/pmap_prot.h>
43 #include <sys/socket.h>
44 #include <stdio.h>
45 #include <net/if.h>
46 #include <sys/ioctl.h>
47 #include <netinet/in.h>
48 #include <arpa/inet.h>
49 
50 /*
51  * don't use gethostbyname, which would invoke yellow pages
52  */
53 get_myaddress(addr)
54 	struct sockaddr_in *addr;
55 {
56 	int s;
57 	char buf[BUFSIZ];
58 	struct ifconf ifc;
59 	struct ifreq ifreq, *ifr;
60 	int len, slop;
61 
62 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
63 	    perror("get_myaddress: socket");
64 	    exit(1);
65 	}
66 	ifc.ifc_len = sizeof (buf);
67 	ifc.ifc_buf = buf;
68 	if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
69 		perror("get_myaddress: ioctl (get interface configuration)");
70 		exit(1);
71 	}
72 	ifr = ifc.ifc_req;
73 	for (len = ifc.ifc_len; len; len -= sizeof ifreq) {
74 		ifreq = *ifr;
75 		if (ioctl(s, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
76 			perror("get_myaddress: ioctl");
77 			exit(1);
78 		}
79 		if ((ifreq.ifr_flags & IFF_UP) &&
80 		    ifr->ifr_addr.sa_family == AF_INET) {
81 			*addr = *((struct sockaddr_in *)&ifr->ifr_addr);
82 			addr->sin_port = htons(PMAPPORT);
83 			break;
84 		}
85 		/*
86 		 * Deal with variable length addresses
87 		 */
88 		slop = ifr->ifr_addr.sa_len - sizeof (struct sockaddr);
89 		if (slop) {
90 			ifr = (struct ifreq *) ((caddr_t)ifr + slop);
91 			len -= slop;
92 		}
93 		ifr++;
94 	}
95 	(void) close(s);
96 }
97