xref: /aosp_15_r20/external/libwebsockets/lib/misc/getifaddrs.c (revision 1c60b9aca93fdbc9b5f19b2d2194c91294b22281)
1 /*
2  * Copyright (c) 2000 - 2001 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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  * originally downloaded from
34  *
35  * http://ftp.uninett.no/pub/OpenBSD/src/kerberosV/src/lib/roken/getifaddrs.c
36  */
37 
38 #include <errno.h>
39 #include <sys/types.h>
40 #include <sys/socket.h>
41 #include <net/if.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <sys/ioctl.h>
45 #include <unistd.h>
46 
47 #include <libwebsockets.h>
48 #include "private-lib-core.h"
49 
50 #ifdef LWS_HAVE_SYS_SOCKIO_H
51 #include <sys/sockio.h>
52 #endif
53 
54 #ifdef LWS_HAVE_NETINET_IN6_VAR_H
55 #include <netinet/in6_var.h>
56 #endif
57 
58 #ifndef max
59 #define max(a, b) ((a) > (b) ? (a) : (b))
60 #endif
61 
62 #include "getifaddrs.h"
63 
64 static int
getifaddrs2(struct ifaddrs ** ifap,int af,int siocgifconf,int siocgifflags,size_t ifreq_sz)65 getifaddrs2(struct ifaddrs **ifap, int af, int siocgifconf, int siocgifflags,
66 	    size_t ifreq_sz)
67 {
68 	int ret;
69 	int fd;
70 	size_t buf_size;
71 	char *buf;
72 	struct ifconf ifconf;
73 	char *p;
74 	size_t sz;
75 	struct sockaddr sa_zero;
76 	struct ifreq *ifr;
77 	struct ifaddrs *start,  **end = &start;
78 
79 	buf = NULL;
80 
81 	memset(&sa_zero, 0, sizeof(sa_zero));
82 	fd = socket(af, SOCK_DGRAM, 0);
83 	if (fd < 0)
84 		return -1;
85 
86 	buf_size = 8192;
87 	for (;;) {
88 		buf = lws_zalloc(buf_size, "getifaddrs2");
89 		if (buf == NULL) {
90 			ret = ENOMEM;
91 			goto error_out;
92 		}
93 		ifconf.ifc_len = (int)buf_size;
94 		ifconf.ifc_buf = buf;
95 
96 		/*
97 		 * Solaris returns EINVAL when the buffer is too small.
98 		 */
99 		if (ioctl(fd, siocgifconf, &ifconf) < 0 && errno != EINVAL) {
100 			ret = errno;
101 			goto error_out;
102 		}
103 		/*
104 		 * Can the difference between a full and a overfull buf
105 		 * be determined?
106 		 */
107 
108 		if (ifconf.ifc_len < (int)buf_size)
109 			break;
110 		lws_free(buf);
111 		buf_size *= 2;
112 	}
113 
114 	for (p = ifconf.ifc_buf; p < ifconf.ifc_buf + ifconf.ifc_len; p += sz) {
115 		struct ifreq ifreq;
116 		struct sockaddr *sa;
117 		size_t salen;
118 
119 		ifr = (struct ifreq *)p;
120 		sa  = &ifr->ifr_addr;
121 
122 		sz = ifreq_sz;
123 		salen = sizeof(struct sockaddr);
124 #ifdef LWS_HAVE_STRUCT_SOCKADDR_SA_LEN
125 		salen = sa->sa_len;
126 		sz = max(sz, sizeof(ifr->ifr_name) + sa->sa_len);
127 #endif
128 #ifdef SA_LEN
129 		salen = SA_LEN(sa);
130 		sz = max(sz, sizeof(ifr->ifr_name) + SA_LEN(sa));
131 #endif
132 		memset(&ifreq, 0, sizeof(ifreq));
133 		memcpy(ifreq.ifr_name, ifr->ifr_name, sizeof(ifr->ifr_name));
134 
135 		if (ioctl(fd, siocgifflags, &ifreq) < 0) {
136 			ret = errno;
137 			goto error_out;
138 		}
139 
140 		*end = lws_malloc(sizeof(**end), "getifaddrs");
141 
142 		(*end)->ifa_next = NULL;
143 		(*end)->ifa_name = strdup(ifr->ifr_name);
144 		(*end)->ifa_flags = (unsigned int)ifreq.ifr_flags;
145 		(*end)->ifa_addr = lws_malloc(salen, "getifaddrs");
146 		memcpy((*end)->ifa_addr, sa, salen);
147 		(*end)->ifa_netmask = NULL;
148 
149 #if 0
150 		/* fix these when we actually need them */
151 		if (ifreq.ifr_flags & IFF_BROADCAST) {
152 			(*end)->ifa_broadaddr =
153 				lws_malloc(sizeof(ifr->ifr_broadaddr), "getifaddrs");
154 			memcpy((*end)->ifa_broadaddr, &ifr->ifr_broadaddr,
155 						    sizeof(ifr->ifr_broadaddr));
156 		} else if (ifreq.ifr_flags & IFF_POINTOPOINT) {
157 			(*end)->ifa_dstaddr =
158 				lws_malloc(sizeof(ifr->ifr_dstaddr), "getifaddrs");
159 			memcpy((*end)->ifa_dstaddr, &ifr->ifr_dstaddr,
160 						      sizeof(ifr->ifr_dstaddr));
161 		} else
162 			(*end)->ifa_dstaddr = NULL;
163 #else
164 		(*end)->ifa_dstaddr = NULL;
165 #endif
166 		(*end)->ifa_data = NULL;
167 
168 		end = &(*end)->ifa_next;
169 
170 	}
171 	*ifap = start;
172 	close(fd);
173 	lws_free(buf);
174 	return 0;
175 
176 error_out:
177 	close(fd);
178 	lws_free(buf);
179 	errno = ret;
180 
181 	return -1;
182 }
183 
184 int
getifaddrs(struct ifaddrs ** ifap)185 getifaddrs(struct ifaddrs **ifap)
186 {
187 	int ret = -1;
188 	errno = ENXIO;
189 #if defined(AF_INET6) && defined(SIOCGIF6CONF) && defined(SIOCGIF6FLAGS)
190 	if (ret)
191 		ret = getifaddrs2(ifap, AF_INET6, SIOCGIF6CONF, SIOCGIF6FLAGS,
192 			   sizeof(struct in6_ifreq));
193 #endif
194 #if defined(LWS_HAVE_IPV6) && defined(SIOCGIFCONF)
195 	if (ret)
196 		ret = getifaddrs2(ifap, AF_INET6, SIOCGIFCONF, SIOCGIFFLAGS,
197 			   sizeof(struct ifreq));
198 #endif
199 #if defined(AF_INET) && defined(SIOCGIFCONF) && defined(SIOCGIFFLAGS)
200 	if (ret)
201 		ret = getifaddrs2(ifap, AF_INET, SIOCGIFCONF, SIOCGIFFLAGS,
202 			   sizeof(struct ifreq));
203 #endif
204 	return ret;
205 }
206 
207 void
freeifaddrs(struct ifaddrs * ifp)208 freeifaddrs(struct ifaddrs *ifp)
209 {
210 	struct ifaddrs *p, *q;
211 
212 	for (p = ifp; p; ) {
213 		lws_free(p->ifa_name);
214 		lws_free(p->ifa_addr);
215 		lws_free(p->ifa_dstaddr);
216 		lws_free(p->ifa_netmask);
217 		lws_free(p->ifa_data);
218 		q = p;
219 		p = p->ifa_next;
220 		lws_free(q);
221 	}
222 }
223 
224 #ifdef TEST
225 
226 void
print_addr(const char * s,struct sockaddr * sa)227 print_addr(const char *s, struct sockaddr *sa)
228 {
229 	int i;
230 	printf("  %s=%d/", s, sa->sa_family);
231 #ifdef LWS_HAVE_STRUCT_SOCKADDR_SA_LEN
232 	for (i = 0;
233 	       i < sa->sa_len - ((lws_intptr_t)sa->sa_data - (lws_intptr_t)&sa->sa_family); i++)
234 		printf("%02x", ((unsigned char *)sa->sa_data)[i]);
235 #else
236 	for (i = 0; i < sizeof(sa->sa_data); i++)
237 		printf("%02x", ((unsigned char *)sa->sa_data)[i]);
238 #endif
239 	printf("\n");
240 }
241 
242 void
print_ifaddrs(struct ifaddrs * x)243 print_ifaddrs(struct ifaddrs *x)
244 {
245 	struct ifaddrs *p;
246 
247 	for (p = x; p; p = p->ifa_next) {
248 		printf("%s\n", p->ifa_name);
249 		printf("  flags=%x\n", p->ifa_flags);
250 		if (p->ifa_addr)
251 			print_addr("addr", p->ifa_addr);
252 		if (p->ifa_dstaddr)
253 			print_addr("dstaddr", p->ifa_dstaddr);
254 		if (p->ifa_netmask)
255 			print_addr("netmask", p->ifa_netmask);
256 		printf("  %p\n", p->ifa_data);
257 	}
258 }
259 
260 int
main()261 main()
262 {
263 	struct ifaddrs *a = NULL, *b;
264 	getifaddrs2(&a, AF_INET, SIOCGIFCONF, SIOCGIFFLAGS,
265 		    sizeof(struct ifreq));
266 	print_ifaddrs(a);
267 	printf("---\n");
268 	getifaddrs(&b);
269 	print_ifaddrs(b);
270 	return 0;
271 }
272 #endif
273