xref: /freebsd/usr.sbin/traceroute/ifaddrlist.c (revision f126890a)
1 /*
2  * Copyright (c) 1997, 1998, 1999, 2000
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the Computer Systems
16  *	Engineering Group at Lawrence Berkeley Laboratory.
17  * 4. Neither the name of the University nor of the Laboratory may be used
18  *    to endorse or promote products derived from this software without
19  *    specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/param.h>
35 #include <sys/file.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/time.h>				/* concession to AIX */
40 
41 #if __STDC__
42 struct mbuf;
43 struct rtentry;
44 #endif
45 
46 #include <net/if.h>
47 #include <netinet/in.h>
48 
49 #include <ctype.h>
50 #include <errno.h>
51 #include <memory.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "ifaddrlist.h"
58 
59 /*
60  * Return the interface list
61  */
62 int
63 ifaddrlist(register struct ifaddrlist **ipaddrp, register char *errbuf)
64 {
65 	register int fd, nipaddr;
66 	size_t n;
67 	register struct ifreq *ifrp, *ifend, *ifnext;
68 	register struct sockaddr_in *sin;
69 	register struct ifaddrlist *al;
70 	struct ifconf ifc;
71 	struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
72 #define MAX_IPADDR ((int)(sizeof(ibuf) / sizeof(ibuf[0])))
73 	static struct ifaddrlist ifaddrlist[MAX_IPADDR];
74 	char device[sizeof(ifr.ifr_name) + 1];
75 
76 	fd = socket(AF_INET, SOCK_DGRAM, 0);
77 	if (fd < 0) {
78 		(void)sprintf(errbuf, "socket: %s", strerror(errno));
79 		return (-1);
80 	}
81 	ifc.ifc_len = sizeof(ibuf);
82 	ifc.ifc_buf = (caddr_t)ibuf;
83 
84 	if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
85 	    ifc.ifc_len < (int)sizeof(struct ifreq)) {
86 		if (errno == EINVAL)
87 			(void)sprintf(errbuf,
88 			    "SIOCGIFCONF: ifreq struct too small (%zu bytes)",
89 			    sizeof(ibuf));
90 		else
91 			(void)sprintf(errbuf, "SIOCGIFCONF: %s",
92 			    strerror(errno));
93 		(void)close(fd);
94 		return (-1);
95 	}
96 	ifrp = ibuf;
97 	ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
98 
99 	al = ifaddrlist;
100 	nipaddr = 0;
101 	for (; ifrp < ifend; ifrp = ifnext) {
102 		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
103 		if (n < sizeof(*ifrp))
104 			ifnext = ifrp + 1;
105 		else
106 			ifnext = (struct ifreq *)((char *)ifrp + n);
107 		if (ifrp->ifr_addr.sa_family != AF_INET)
108 			continue;
109 		/*
110 		 * Need a template to preserve address info that is
111 		 * used below to locate the next entry.  (Otherwise,
112 		 * SIOCGIFFLAGS stomps over it because the requests
113 		 * are returned in a union.)
114 		 */
115 		strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
116 		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
117 			if (errno == ENXIO)
118 				continue;
119 			(void)sprintf(errbuf, "SIOCGIFFLAGS: %.*s: %s",
120 			    (int)sizeof(ifr.ifr_name), ifr.ifr_name,
121 			    strerror(errno));
122 			(void)close(fd);
123 			return (-1);
124 		}
125 
126 		/* Must be up */
127 		if ((ifr.ifr_flags & IFF_UP) == 0)
128 			continue;
129 
130 
131 		(void)strlcpy(device, ifr.ifr_name, sizeof(device));
132 #ifdef sun
133 		/* Ignore sun virtual interfaces */
134 		if (strchr(device, ':') != NULL)
135 			continue;
136 #endif
137 		if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
138 			(void)sprintf(errbuf, "SIOCGIFADDR: %s: %s",
139 			    device, strerror(errno));
140 			(void)close(fd);
141 			return (-1);
142 		}
143 
144 		if (nipaddr >= MAX_IPADDR) {
145 			(void)sprintf(errbuf, "Too many interfaces (%d)",
146 			    MAX_IPADDR);
147 			(void)close(fd);
148 			return (-1);
149 		}
150 		sin = (struct sockaddr_in *)&ifr.ifr_addr;
151 		al->addr = sin->sin_addr.s_addr;
152 		al->device = strdup(device);
153 		++al;
154 		++nipaddr;
155 	}
156 	(void)close(fd);
157 
158 	*ipaddrp = ifaddrlist;
159 	return (nipaddr);
160 }
161