1 /*
2 * Copyright (C) 2004, 2005, 2007-2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 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: ifiter_getifaddrs.c,v 1.13 2009/09/24 23:48:13 tbox Exp $ */
19
20 /*! \file
21 * \brief
22 * Obtain the list of network interfaces using the getifaddrs(3) library.
23 */
24
25 #include <ifaddrs.h>
26
27 /*% Iterator Magic */
28 #define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'G')
29 /*% Valid Iterator */
30 #define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC)
31
32 #ifdef __linux
33 static isc_boolean_t seenv6 = ISC_FALSE;
34 #endif
35
36 /*% Iterator structure */
37 struct isc_interfaceiter {
38 unsigned int magic; /*%< Magic number. */
39 isc_mem_t *mctx;
40 void *buf; /*%< (unused) */
41 unsigned int bufsize; /*%< (always 0) */
42 struct ifaddrs *ifaddrs; /*%< List of ifaddrs */
43 struct ifaddrs *pos; /*%< Ptr to current ifaddr */
44 isc_interface_t current; /*%< Current interface data. */
45 isc_result_t result; /*%< Last result code. */
46 #ifdef __linux
47 FILE * proc;
48 char entry[ISC_IF_INET6_SZ];
49 isc_result_t valid;
50 #endif
51 };
52
53 isc_result_t
isc_interfaceiter_create(isc_mem_t * mctx,isc_interfaceiter_t ** iterp)54 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
55 isc_interfaceiter_t *iter;
56 isc_result_t result;
57 char strbuf[ISC_STRERRORSIZE];
58 int trys, ret;
59
60 REQUIRE(mctx != NULL);
61 REQUIRE(iterp != NULL);
62 REQUIRE(*iterp == NULL);
63
64 iter = isc_mem_get(mctx, sizeof(*iter));
65 if (iter == NULL)
66 return (ISC_R_NOMEMORY);
67
68 iter->mctx = mctx;
69 iter->buf = NULL;
70 iter->bufsize = 0;
71 iter->ifaddrs = NULL;
72 #ifdef __linux
73 /*
74 * Only open "/proc/net/if_inet6" if we have never seen a IPv6
75 * address returned by getifaddrs().
76 */
77 if (!seenv6) {
78 iter->proc = fopen("/proc/net/if_inet6", "r");
79 if (iter->proc == NULL) {
80 isc__strerror(errno, strbuf, sizeof(strbuf));
81 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
82 ISC_LOGMODULE_SOCKET, ISC_LOG_WARNING,
83 "failed to open /proc/net/if_inet6");
84 }
85 } else
86 iter->proc = NULL;
87 iter->valid = ISC_R_FAILURE;
88 #endif
89
90 /* If interrupted, try again */
91 for (trys = 0; trys < 3; trys++) {
92 if ((ret = getifaddrs(&iter->ifaddrs)) >= 0)
93 break;
94 if (errno != EINTR)
95 break;
96 }
97 if (ret < 0) {
98 isc__strerror(errno, strbuf, sizeof(strbuf));
99 UNEXPECTED_ERROR(__FILE__, __LINE__,
100 "getting interface addresses: %s: %s",
101 isc_msgcat_get(isc_msgcat,
102 ISC_MSGSET_IFITERGETIFADDRS,
103 ISC_MSG_GETIFADDRS,
104 "getifaddrs"),
105 strbuf);
106 result = ISC_R_UNEXPECTED;
107 goto failure;
108 }
109
110 /*
111 * A newly created iterator has an undefined position
112 * until isc_interfaceiter_first() is called.
113 */
114 iter->pos = NULL;
115 iter->result = ISC_R_FAILURE;
116
117 iter->magic = IFITER_MAGIC;
118 *iterp = iter;
119 return (ISC_R_SUCCESS);
120
121 failure:
122 #ifdef __linux
123 if (iter->proc != NULL)
124 fclose(iter->proc);
125 #endif
126 if (iter->ifaddrs != NULL) /* just in case */
127 freeifaddrs(iter->ifaddrs);
128 isc_mem_put(mctx, iter, sizeof(*iter));
129 return (result);
130 }
131
132 /*
133 * Get information about the current interface to iter->current.
134 * If successful, return ISC_R_SUCCESS.
135 * If the interface has an unsupported address family,
136 * return ISC_R_IGNORE.
137 */
138
139 static isc_result_t
internal_current(isc_interfaceiter_t * iter)140 internal_current(isc_interfaceiter_t *iter) {
141 struct ifaddrs *ifa;
142 int family;
143 unsigned int namelen;
144
145 REQUIRE(VALID_IFITER(iter));
146
147 ifa = iter->pos;
148
149 #ifdef __linux
150 /*
151 * [Bug 2792]
152 * burnicki: iter->pos is usually never NULL here (anymore?),
153 * so linux_if_inet6_current(iter) is never called here.
154 * However, that routine would check (under Linux), if the
155 * interface is in a tentative state, e.g. if there's no link
156 * yet but an IPv6 address has already be assigned.
157 */
158 if (iter->pos == NULL)
159 return (linux_if_inet6_current(iter));
160 #endif
161
162 INSIST(ifa != NULL);
163 INSIST(ifa->ifa_name != NULL);
164
165
166 #ifdef IFF_RUNNING
167 /*
168 * [Bug 2792]
169 * burnicki: if the interface is not running then
170 * it may be in a tentative state. See above.
171 */
172 if ((ifa->ifa_flags & IFF_RUNNING) == 0)
173 return (ISC_R_IGNORE);
174 #endif
175
176 if (ifa->ifa_addr == NULL)
177 return (ISC_R_IGNORE);
178
179 family = ifa->ifa_addr->sa_family;
180 if (family != AF_INET && family != AF_INET6)
181 return (ISC_R_IGNORE);
182
183 #ifdef __linux
184 if (family == AF_INET6)
185 seenv6 = ISC_TRUE;
186 #endif
187
188 memset(&iter->current, 0, sizeof(iter->current));
189
190 namelen = strlen(ifa->ifa_name);
191 if (namelen > sizeof(iter->current.name) - 1)
192 namelen = sizeof(iter->current.name) - 1;
193
194 memset(iter->current.name, 0, sizeof(iter->current.name));
195 memcpy(iter->current.name, ifa->ifa_name, namelen);
196
197 iter->current.flags = 0;
198
199 if ((ifa->ifa_flags & IFF_UP) != 0)
200 iter->current.flags |= INTERFACE_F_UP;
201
202 if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
203 iter->current.flags |= INTERFACE_F_POINTTOPOINT;
204
205 if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
206 iter->current.flags |= INTERFACE_F_LOOPBACK;
207
208 if ((ifa->ifa_flags & IFF_BROADCAST) != 0)
209 iter->current.flags |= INTERFACE_F_BROADCAST;
210
211 #ifdef IFF_MULTICAST
212 if ((ifa->ifa_flags & IFF_MULTICAST) != 0)
213 iter->current.flags |= INTERFACE_F_MULTICAST;
214 #endif
215
216 iter->current.af = family;
217
218 get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name);
219
220 if (ifa->ifa_netmask != NULL)
221 get_addr(family, &iter->current.netmask, ifa->ifa_netmask,
222 ifa->ifa_name);
223
224 if (ifa->ifa_dstaddr != NULL &&
225 (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
226 get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr,
227 ifa->ifa_name);
228
229 if (ifa->ifa_broadaddr != NULL &&
230 (iter->current.flags & INTERFACE_F_BROADCAST) != 0)
231 get_addr(family, &iter->current.broadcast, ifa->ifa_broadaddr,
232 ifa->ifa_name);
233
234 #ifdef ISC_PLATFORM_HAVEIFNAMETOINDEX
235 iter->current.ifindex = if_nametoindex(iter->current.name);
236 #endif
237 return (ISC_R_SUCCESS);
238 }
239
240 /*
241 * Step the iterator to the next interface. Unlike
242 * isc_interfaceiter_next(), this may leave the iterator
243 * positioned on an interface that will ultimately
244 * be ignored. Return ISC_R_NOMORE if there are no more
245 * interfaces, otherwise ISC_R_SUCCESS.
246 */
247 static isc_result_t
internal_next(isc_interfaceiter_t * iter)248 internal_next(isc_interfaceiter_t *iter) {
249
250 if (iter->pos != NULL)
251 iter->pos = iter->pos->ifa_next;
252 if (iter->pos == NULL) {
253 #ifdef __linux
254 if (!seenv6)
255 return (linux_if_inet6_next(iter));
256 #endif
257 return (ISC_R_NOMORE);
258 }
259
260 return (ISC_R_SUCCESS);
261 }
262
263 static void
internal_destroy(isc_interfaceiter_t * iter)264 internal_destroy(isc_interfaceiter_t *iter) {
265
266 #ifdef __linux
267 if (iter->proc != NULL)
268 fclose(iter->proc);
269 iter->proc = NULL;
270 #endif
271 if (iter->ifaddrs)
272 freeifaddrs(iter->ifaddrs);
273 iter->ifaddrs = NULL;
274 }
275
276 static
internal_first(isc_interfaceiter_t * iter)277 void internal_first(isc_interfaceiter_t *iter) {
278
279 #ifdef __linux
280 linux_if_inet6_first(iter);
281 #endif
282 iter->pos = iter->ifaddrs;
283 }
284