1 /*
2 * Copyright (C) 2004, 2005, 2007, 2008 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003 Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* $Id: interfaceiter.c,v 1.45 2008/12/01 03:51:47 marka Exp $ */
19
20 /*! \file */
21
22 #include <config.h>
23
24 #include <sys/types.h>
25 #include <sys/ioctl.h>
26 #ifdef HAVE_SYS_SOCKIO_H
27 #include <sys/sockio.h> /* Required for ifiter_ioctl.c. */
28 #endif
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include <errno.h>
34
35 #include <isc/interfaceiter.h>
36 #include <isc/log.h>
37 #include <isc/magic.h>
38 #include <isc/mem.h>
39 #include <isc/msgs.h>
40 #include <isc/net.h>
41 #include <isc/print.h>
42 #include <isc/result.h>
43 #include <isc/strerror.h>
44 #include <isc/string.h>
45 #include <isc/types.h>
46 #include <isc/util.h>
47
48 /* Must follow <isc/net.h>. */
49 #ifdef HAVE_NET_IF6_H
50 #include <net/if6.h>
51 #endif
52 #include <net/if.h>
53
54 #ifdef HAVE_LINUX_IF_ADDR_H
55 # include <linux/if_addr.h>
56 #endif
57
58 /* Common utility functions */
59
60 /*%
61 * Extract the network address part from a "struct sockaddr".
62 * \brief
63 * The address family is given explicitly
64 * instead of using src->sa_family, because the latter does not work
65 * for copying a network mask obtained by SIOCGIFNETMASK (it does
66 * not have a valid address family).
67 */
68
69 static void
get_addr(unsigned int family,isc_netaddr_t * dst,struct sockaddr * src,char * ifname)70 get_addr(unsigned int family, isc_netaddr_t *dst, struct sockaddr *src,
71 char *ifname)
72 {
73 struct sockaddr_in6 *sa6;
74
75 #if !defined(ISC_PLATFORM_HAVEIFNAMETOINDEX) || \
76 !defined(ISC_PLATFORM_HAVESCOPEID)
77 UNUSED(ifname);
78 #endif
79
80 /* clear any remaining value for safety */
81 memset(dst, 0, sizeof(*dst));
82
83 dst->family = family;
84 switch (family) {
85 case AF_INET:
86 memcpy(&dst->type.in,
87 &((struct sockaddr_in *)(void *)src)->sin_addr,
88 sizeof(struct in_addr));
89 break;
90 case AF_INET6:
91 sa6 = (struct sockaddr_in6 *)(void *)src;
92 memcpy(&dst->type.in6, &sa6->sin6_addr,
93 sizeof(struct in6_addr));
94 #ifdef ISC_PLATFORM_HAVESCOPEID
95 if (sa6->sin6_scope_id != 0)
96 isc_netaddr_setzone(dst, sa6->sin6_scope_id);
97 else {
98 /*
99 * BSD variants embed scope zone IDs in the 128bit
100 * address as a kernel internal form. Unfortunately,
101 * the embedded IDs are not hidden from applications
102 * when getting access to them by sysctl or ioctl.
103 * We convert the internal format to the pure address
104 * part and the zone ID part.
105 * Since multicast addresses should not appear here
106 * and they cannot be distinguished from netmasks,
107 * we only consider unicast link-local addresses.
108 */
109 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
110 isc_uint16_t zone16;
111
112 memcpy(&zone16, &sa6->sin6_addr.s6_addr[2],
113 sizeof(zone16));
114 zone16 = ntohs(zone16);
115 if (zone16 != 0) {
116 /* the zone ID is embedded */
117 isc_netaddr_setzone(dst,
118 (isc_uint32_t)zone16);
119 dst->type.in6.s6_addr[2] = 0;
120 dst->type.in6.s6_addr[3] = 0;
121 #ifdef ISC_PLATFORM_HAVEIFNAMETOINDEX
122 } else if (ifname != NULL) {
123 unsigned int zone;
124
125 /*
126 * sin6_scope_id is still not provided,
127 * but the corresponding interface name
128 * is know. Use the interface ID as
129 * the link ID.
130 */
131 zone = if_nametoindex(ifname);
132 if (zone != 0) {
133 isc_netaddr_setzone(dst,
134 (isc_uint32_t)zone);
135 }
136 #endif
137 }
138 }
139 }
140 #endif
141 break;
142 default:
143 INSIST(0);
144 break;
145 }
146 }
147
148 /*
149 * Include system-dependent code.
150 */
151
152 #ifdef __linux
153 #define ISC_IF_INET6_SZ \
154 sizeof("00000000000000000000000000000001 01 80 10 80 XXXXXXloXXXXXXXX\n")
155 static isc_result_t linux_if_inet6_next(isc_interfaceiter_t *);
156 static isc_result_t linux_if_inet6_current(isc_interfaceiter_t *);
157 static void linux_if_inet6_first(isc_interfaceiter_t *iter);
158 #endif
159
160 #if HAVE_GETIFADDRS
161 #include "ifiter_getifaddrs.c"
162 #elif HAVE_IFLIST_SYSCTL
163 #include "ifiter_sysctl.c"
164 #else
165 #include "ifiter_ioctl.c"
166 #endif
167
168 #ifdef __linux
169 static void
linux_if_inet6_first(isc_interfaceiter_t * iter)170 linux_if_inet6_first(isc_interfaceiter_t *iter) {
171 if (iter->proc != NULL) {
172 rewind(iter->proc);
173 (void)linux_if_inet6_next(iter);
174 } else
175 iter->valid = ISC_R_NOMORE;
176 }
177
178 static isc_result_t
linux_if_inet6_next(isc_interfaceiter_t * iter)179 linux_if_inet6_next(isc_interfaceiter_t *iter) {
180 if (iter->proc != NULL &&
181 fgets(iter->entry, sizeof(iter->entry), iter->proc) != NULL)
182 iter->valid = ISC_R_SUCCESS;
183 else
184 iter->valid = ISC_R_NOMORE;
185 return (iter->valid);
186 }
187
188 static isc_result_t
linux_if_inet6_current(isc_interfaceiter_t * iter)189 linux_if_inet6_current(isc_interfaceiter_t *iter) {
190 char address[33];
191 char name[IF_NAMESIZE+1];
192 struct in6_addr addr6;
193 unsigned int ifindex;
194 int prefix, scope, flags;
195 int res;
196 unsigned int i;
197
198 if (iter->valid != ISC_R_SUCCESS)
199 return (iter->valid);
200 if (iter->proc == NULL) {
201 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
202 ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
203 "/proc/net/if_inet6:iter->proc == NULL");
204 return (ISC_R_FAILURE);
205 }
206
207 res = sscanf(iter->entry, "%32[a-f0-9] %x %x %x %x %16s\n",
208 address, &ifindex, &prefix, &scope, &flags, name);
209 if (res != 6) {
210 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
211 ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
212 "/proc/net/if_inet6:sscanf() -> %d (expected 6)",
213 res);
214 return (ISC_R_FAILURE);
215 }
216 if (strlen(address) != 32) {
217 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
218 ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
219 "/proc/net/if_inet6:strlen(%s) != 32", address);
220 return (ISC_R_FAILURE);
221 }
222 /*
223 ** Ignore DAD addresses --
224 ** we can't bind to them until they are resolved
225 */
226 #ifdef IFA_F_TENTATIVE
227 if (flags & IFA_F_TENTATIVE)
228 return (ISC_R_IGNORE);
229 #endif
230
231 for (i = 0; i < 16; i++) {
232 unsigned char byte;
233 static const char hex[] = "0123456789abcdef";
234 byte = ((strchr(hex, address[i * 2]) - hex) << 4) |
235 (strchr(hex, address[i * 2 + 1]) - hex);
236 addr6.s6_addr[i] = byte;
237 }
238 iter->current.af = AF_INET6;
239 iter->current.flags = INTERFACE_F_UP;
240 isc_netaddr_fromin6(&iter->current.address, &addr6);
241 iter->current.ifindex = ifindex;
242 if (isc_netaddr_islinklocal(&iter->current.address)) {
243 isc_netaddr_setzone(&iter->current.address,
244 (isc_uint32_t)ifindex);
245 }
246 for (i = 0; i < 16; i++) {
247 if (prefix > 8) {
248 addr6.s6_addr[i] = 0xff;
249 prefix -= 8;
250 } else {
251 addr6.s6_addr[i] = (0xff << (8 - prefix)) & 0xff;
252 prefix = 0;
253 }
254 }
255 isc_netaddr_fromin6(&iter->current.netmask, &addr6);
256 strncpy(iter->current.name, name, sizeof(iter->current.name));
257 return (ISC_R_SUCCESS);
258 }
259 #endif
260
261 /*
262 * The remaining code is common to the sysctl and ioctl case.
263 */
264
265 isc_result_t
isc_interfaceiter_current(isc_interfaceiter_t * iter,isc_interface_t * ifdata)266 isc_interfaceiter_current(isc_interfaceiter_t *iter,
267 isc_interface_t *ifdata)
268 {
269 REQUIRE(iter->result == ISC_R_SUCCESS);
270 memcpy(ifdata, &iter->current, sizeof(*ifdata));
271 return (ISC_R_SUCCESS);
272 }
273
274 isc_result_t
isc_interfaceiter_first(isc_interfaceiter_t * iter)275 isc_interfaceiter_first(isc_interfaceiter_t *iter) {
276 isc_result_t result;
277
278 REQUIRE(VALID_IFITER(iter));
279
280 internal_first(iter);
281 for (;;) {
282 result = internal_current(iter);
283 if (result != ISC_R_IGNORE)
284 break;
285 result = internal_next(iter);
286 if (result != ISC_R_SUCCESS)
287 break;
288 }
289 iter->result = result;
290 return (result);
291 }
292
293 isc_result_t
isc_interfaceiter_next(isc_interfaceiter_t * iter)294 isc_interfaceiter_next(isc_interfaceiter_t *iter) {
295 isc_result_t result;
296
297 REQUIRE(VALID_IFITER(iter));
298 REQUIRE(iter->result == ISC_R_SUCCESS);
299
300 for (;;) {
301 result = internal_next(iter);
302 if (result != ISC_R_SUCCESS)
303 break;
304 result = internal_current(iter);
305 if (result != ISC_R_IGNORE)
306 break;
307 }
308 iter->result = result;
309 return (result);
310 }
311
312 void
isc_interfaceiter_destroy(isc_interfaceiter_t ** iterp)313 isc_interfaceiter_destroy(isc_interfaceiter_t **iterp)
314 {
315 isc_interfaceiter_t *iter;
316 REQUIRE(iterp != NULL);
317 iter = *iterp;
318 REQUIRE(VALID_IFITER(iter));
319
320 internal_destroy(iter);
321 if (iter->buf != NULL)
322 isc_mem_put(iter->mctx, iter->buf, iter->bufsize);
323
324 iter->magic = 0;
325 isc_mem_put(iter->mctx, iter, sizeof(*iter));
326 *iterp = NULL;
327 }
328