1 /*
2 * Copyright (C) 2004, 2005, 2007 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: ifiter_sysctl.c,v 1.25 2007/06/19 23:47:18 tbox Exp $ */
19
20 /*! \file
21 * \brief
22 * Obtain the list of network interfaces using sysctl.
23 * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
24 * and 19.16.
25 */
26
27 #include <sys/param.h>
28 #include <sys/sysctl.h>
29
30 #include <net/route.h>
31 #include <net/if_dl.h>
32
33 /* XXX what about Alpha? */
34 #ifdef sgi
35 #define ROUNDUP(a) ((a) > 0 ? \
36 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
37 sizeof(__uint64_t))
38 #else
39 #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
40 : sizeof(long))
41 #endif
42
43 #define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'S')
44 #define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC)
45
46 struct isc_interfaceiter {
47 unsigned int magic; /* Magic number. */
48 isc_mem_t *mctx;
49 void *buf; /* Buffer for sysctl data. */
50 unsigned int bufsize; /* Bytes allocated. */
51 unsigned int bufused; /* Bytes used. */
52 unsigned int pos; /* Current offset in
53 sysctl data. */
54 isc_interface_t current; /* Current interface data. */
55 isc_result_t result; /* Last result code. */
56 };
57
58 static int mib[6] = {
59 CTL_NET,
60 PF_ROUTE,
61 0,
62 0, /* Any address family. */
63 NET_RT_IFLIST,
64 0 /* Flags. */
65 };
66
67 isc_result_t
isc_interfaceiter_create(isc_mem_t * mctx,isc_interfaceiter_t ** iterp)68 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
69 isc_interfaceiter_t *iter;
70 isc_result_t result;
71 size_t bufsize;
72 size_t bufused;
73 char strbuf[ISC_STRERRORSIZE];
74
75 REQUIRE(mctx != NULL);
76 REQUIRE(iterp != NULL);
77 REQUIRE(*iterp == NULL);
78
79 iter = isc_mem_get(mctx, sizeof(*iter));
80 if (iter == NULL)
81 return (ISC_R_NOMEMORY);
82
83 iter->mctx = mctx;
84 iter->buf = 0;
85
86 /*
87 * Determine the amount of memory needed.
88 */
89 bufsize = 0;
90 if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
91 isc__strerror(errno, strbuf, sizeof(strbuf));
92 UNEXPECTED_ERROR(__FILE__, __LINE__,
93 isc_msgcat_get(isc_msgcat,
94 ISC_MSGSET_IFITERSYSCTL,
95 ISC_MSG_GETIFLISTSIZE,
96 "getting interface "
97 "list size: sysctl: %s"),
98 strbuf);
99 result = ISC_R_UNEXPECTED;
100 goto failure;
101 }
102 iter->bufsize = bufsize;
103
104 iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
105 if (iter->buf == NULL) {
106 result = ISC_R_NOMEMORY;
107 goto failure;
108 }
109
110 bufused = bufsize;
111 if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
112 isc__strerror(errno, strbuf, sizeof(strbuf));
113 UNEXPECTED_ERROR(__FILE__, __LINE__,
114 isc_msgcat_get(isc_msgcat,
115 ISC_MSGSET_IFITERSYSCTL,
116 ISC_MSG_GETIFLIST,
117 "getting interface list: "
118 "sysctl: %s"),
119 strbuf);
120 result = ISC_R_UNEXPECTED;
121 goto failure;
122 }
123 iter->bufused = bufused;
124 INSIST(iter->bufused <= iter->bufsize);
125
126 /*
127 * A newly created iterator has an undefined position
128 * until isc_interfaceiter_first() is called.
129 */
130 iter->pos = (unsigned int) -1;
131 iter->result = ISC_R_FAILURE;
132
133 iter->magic = IFITER_MAGIC;
134 *iterp = iter;
135 return (ISC_R_SUCCESS);
136
137 failure:
138 if (iter->buf != NULL)
139 isc_mem_put(mctx, iter->buf, iter->bufsize);
140 isc_mem_put(mctx, iter, sizeof(*iter));
141 return (result);
142 }
143
144 /*
145 * Get information about the current interface to iter->current.
146 * If successful, return ISC_R_SUCCESS.
147 * If the interface has an unsupported address family,
148 * return ISC_R_IGNORE. In case of other failure,
149 * return ISC_R_UNEXPECTED.
150 */
151
152 static isc_result_t
internal_current(isc_interfaceiter_t * iter)153 internal_current(isc_interfaceiter_t *iter) {
154 struct ifa_msghdr *ifam, *ifam_end;
155
156 REQUIRE(VALID_IFITER(iter));
157 REQUIRE (iter->pos < (unsigned int) iter->bufused);
158
159 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
160 ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
161
162 // Skip wrong RTM version headers
163 if (ifam->ifam_version != RTM_VERSION)
164 return (ISC_R_IGNORE);
165
166 if (ifam->ifam_type == RTM_IFINFO) {
167 struct if_msghdr *ifm = (struct if_msghdr *) ifam;
168 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
169 unsigned int namelen;
170
171 memset(&iter->current, 0, sizeof(iter->current));
172
173 iter->current.ifindex = sdl->sdl_index;
174 namelen = sdl->sdl_nlen;
175 if (namelen > sizeof(iter->current.name) - 1)
176 namelen = sizeof(iter->current.name) - 1;
177
178 memset(iter->current.name, 0, sizeof(iter->current.name));
179 memcpy(iter->current.name, sdl->sdl_data, namelen);
180
181 iter->current.flags = 0;
182
183 if ((ifam->ifam_flags & IFF_UP) != 0)
184 iter->current.flags |= INTERFACE_F_UP;
185
186 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
187 iter->current.flags |= INTERFACE_F_POINTTOPOINT;
188
189 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
190 iter->current.flags |= INTERFACE_F_LOOPBACK;
191
192 if ((ifam->ifam_flags & IFF_BROADCAST) != 0)
193 iter->current.flags |= INTERFACE_F_BROADCAST;
194
195 #ifdef IFF_MULTICAST
196 if ((ifam->ifam_flags & IFF_MULTICAST) != 0)
197 iter->current.flags |= INTERFACE_F_MULTICAST;
198 #endif
199
200 /*
201 * This is not an interface address.
202 * Force another iteration.
203 */
204 return (ISC_R_IGNORE);
205 } else if (ifam->ifam_type == RTM_NEWADDR) {
206 int i;
207 int family;
208 struct sockaddr *mask_sa = NULL;
209 struct sockaddr *addr_sa = NULL;
210 struct sockaddr *dst_sa = NULL;
211
212 struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
213 family = sa->sa_family;
214
215 for (i = 0; i < RTAX_MAX; i++)
216 {
217 if ((ifam->ifam_addrs & (1 << i)) == 0)
218 continue;
219
220 INSIST(sa < (struct sockaddr *) ifam_end);
221
222 switch (i) {
223 case RTAX_NETMASK: /* Netmask */
224 mask_sa = sa;
225 break;
226 case RTAX_IFA: /* Interface address */
227 addr_sa = sa;
228 break;
229 case RTAX_BRD: /* Broadcast or destination address */
230 dst_sa = sa;
231 break;
232 }
233 #ifdef ISC_PLATFORM_HAVESALEN
234 sa = (struct sockaddr *)((char*)(sa)
235 + ROUNDUP(sa->sa_len));
236 #else
237 #ifdef sgi
238 /*
239 * Do as the contributed SGI code does.
240 */
241 sa = (struct sockaddr *)((char*)(sa)
242 + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
243 #else
244 /* XXX untested. */
245 sa = (struct sockaddr *)((char*)(sa)
246 + ROUNDUP(sizeof(struct sockaddr)));
247 #endif
248 #endif
249 }
250
251 if (addr_sa == NULL)
252 return (ISC_R_IGNORE);
253
254 family = addr_sa->sa_family;
255 if (family != AF_INET && family != AF_INET6)
256 return (ISC_R_IGNORE);
257
258 iter->current.af = family;
259
260 get_addr(family, &iter->current.address, addr_sa,
261 iter->current.name);
262
263 if (mask_sa != NULL)
264 get_addr(family, &iter->current.netmask, mask_sa,
265 iter->current.name);
266
267 if (dst_sa != NULL &&
268 (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
269 get_addr(family, &iter->current.dstaddress, dst_sa,
270 iter->current.name);
271
272 if (dst_sa != NULL &&
273 (iter->current.flags & INTERFACE_F_BROADCAST) != 0)
274 get_addr(family, &iter->current.broadcast, dst_sa,
275 iter->current.name);
276
277 return (ISC_R_SUCCESS);
278 } else {
279 printf("%s", isc_msgcat_get(isc_msgcat,
280 ISC_MSGSET_IFITERSYSCTL,
281 ISC_MSG_UNEXPECTEDTYPE,
282 "warning: unexpected interface "
283 "list message type\n"));
284 return (ISC_R_IGNORE);
285 }
286 }
287
288 /*
289 * Step the iterator to the next interface. Unlike
290 * isc_interfaceiter_next(), this may leave the iterator
291 * positioned on an interface that will ultimately
292 * be ignored. Return ISC_R_NOMORE if there are no more
293 * interfaces, otherwise ISC_R_SUCCESS.
294 */
295 static isc_result_t
internal_next(isc_interfaceiter_t * iter)296 internal_next(isc_interfaceiter_t *iter) {
297 struct ifa_msghdr *ifam;
298 REQUIRE (iter->pos < (unsigned int) iter->bufused);
299
300 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
301
302 iter->pos += ifam->ifam_msglen;
303
304 if (iter->pos >= iter->bufused)
305 return (ISC_R_NOMORE);
306
307 return (ISC_R_SUCCESS);
308 }
309
310 static void
internal_destroy(isc_interfaceiter_t * iter)311 internal_destroy(isc_interfaceiter_t *iter) {
312 UNUSED(iter); /* Unused. */
313 /*
314 * Do nothing.
315 */
316 }
317
318 static
internal_first(isc_interfaceiter_t * iter)319 void internal_first(isc_interfaceiter_t *iter) {
320 iter->pos = 0;
321 }
322