1 /*
2 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3 *
4 * This Source Code Form is subject to the terms of the Mozilla Public
5 * License, v. 2.0. If a copy of the MPL was not distributed with this
6 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
7 *
8 * See the COPYRIGHT file distributed with this work for additional
9 * information regarding copyright ownership.
10 */
11
12
13 /*
14 * Note that this code will need to be revisited to support IPv6 Interfaces.
15 * For now we just iterate through IPv4 interfaces.
16 */
17
18 #include <config.h>
19 #include <winsock2.h>
20 #include <ws2tcpip.h>
21 #include <sys/types.h>
22
23 #include <stdbool.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <errno.h>
27
28 #include <isc/interfaceiter.h>
29 #include <isc/mem.h>
30 #include <isc/print.h>
31 #include <isc/result.h>
32 #include <isc/string.h>
33 #include <isc/strerror.h>
34 #include <isc/types.h>
35 #include <isc/util.h>
36
37 void InitSockets(void);
38
39 /* Common utility functions */
40
41 /*
42 * Extract the network address part from a "struct sockaddr".
43 *
44 * The address family is given explicitly
45 * instead of using src->sa_family, because the latter does not work
46 * for copying a network mask obtained by SIOCGIFNETMASK (it does
47 * not have a valid address family).
48 */
49
50
51 #define IFITER_MAGIC 0x49464954U /* IFIT. */
52 #define VALID_IFITER(t) ((t) != NULL && (t)->magic == IFITER_MAGIC)
53
54 struct isc_interfaceiter {
55 unsigned int magic; /* Magic number. */
56 isc_mem_t *mctx;
57 SOCKET socket;
58 INTERFACE_INFO IFData; /* Current Interface Info. */
59 int numIF; /* Current Interface count. */
60 int v4IF; /* Number of IPv4 Interfaces */
61 INTERFACE_INFO *buf4; /* Buffer for WSAIoctl data. */
62 unsigned int buf4size; /* Bytes allocated. */
63 INTERFACE_INFO *pos4; /* Current offset in IF List */
64 SOCKET_ADDRESS_LIST *buf6; /* Buffer for WSAIoctl data. */
65 unsigned int buf6size; /* Bytes allocated. */
66 unsigned int pos6; /* Which entry to process. */
67 bool v6loop; /* See IPv6 loop address. */
68 bool pos6zero; /* Done pos6 == 0. */
69 isc_interface_t current; /* Current interface data. */
70 isc_result_t result; /* Last result code. */
71 };
72
73
74 /*
75 * Size of buffer for SIO_GET_INTERFACE_LIST, in number of interfaces.
76 * We assume no sane system will have more than than 1K of IP addresses on
77 * all of its adapters.
78 */
79 #define IFCONF_SIZE_INITIAL 16
80 #define IFCONF_SIZE_INCREMENT 64
81 #define IFCONF_SIZE_MAX 1040
82
83 static void
get_addr(unsigned int family,isc_netaddr_t * dst,struct sockaddr * src)84 get_addr(unsigned int family, isc_netaddr_t *dst, struct sockaddr *src) {
85 dst->family = family;
86 switch (family) {
87 case AF_INET:
88 memmove(&dst->type.in,
89 &((struct sockaddr_in *) src)->sin_addr,
90 sizeof(struct in_addr));
91 break;
92 case AF_INET6:
93 memmove(&dst->type.in6,
94 &((struct sockaddr_in6 *) src)->sin6_addr,
95 sizeof(struct in6_addr));
96 dst->zone = ((struct sockaddr_in6 *) src)->sin6_scope_id;
97 break;
98 default:
99 INSIST(0);
100 ISC_UNREACHABLE();
101 }
102 }
103
104 isc_result_t
isc_interfaceiter_create(isc_mem_t * mctx,isc_interfaceiter_t ** iterp)105 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
106 char strbuf[ISC_STRERRORSIZE];
107 isc_interfaceiter_t *iter;
108 isc_result_t result;
109 int error;
110 unsigned long bytesReturned = 0;
111
112 REQUIRE(mctx != NULL);
113 REQUIRE(iterp != NULL);
114 REQUIRE(*iterp == NULL);
115
116 iter = isc_mem_get(mctx, sizeof(*iter));
117 if (iter == NULL)
118 return (ISC_R_NOMEMORY);
119
120 InitSockets();
121
122 iter->mctx = mctx;
123 iter->buf4 = NULL;
124 iter->buf6 = NULL;
125 iter->pos4 = NULL;
126 iter->pos6 = 0;
127 iter->v6loop = true;
128 iter->pos6zero = true;
129 iter->buf6size = 0;
130 iter->buf4size = 0;
131 iter->result = ISC_R_FAILURE;
132 iter->numIF = 0;
133 iter->v4IF = 0;
134
135 /*
136 * Create an unbound datagram socket to do the
137 * SIO_GET_INTERFACE_LIST WSAIoctl on.
138 */
139 iter->socket = socket(AF_INET, SOCK_DGRAM, 0);
140 if (iter->socket == INVALID_SOCKET) {
141 error = WSAGetLastError();
142 if (error == WSAEAFNOSUPPORT)
143 goto inet6_only;
144 isc__strerror(error, strbuf, sizeof(strbuf));
145 UNEXPECTED_ERROR(__FILE__, __LINE__,
146 "making interface scan socket: %s",
147 strbuf);
148 result = ISC_R_UNEXPECTED;
149 goto socket_failure;
150 }
151
152 /*
153 * Get the interface configuration, allocating more memory if
154 * necessary.
155 */
156 iter->buf4size = IFCONF_SIZE_INITIAL*sizeof(INTERFACE_INFO);
157
158 for (;;) {
159 iter->buf4 = isc_mem_get(mctx, iter->buf4size);
160 if (iter->buf4 == NULL) {
161 result = ISC_R_NOMEMORY;
162 goto alloc_failure;
163 }
164
165 if (WSAIoctl(iter->socket, SIO_GET_INTERFACE_LIST,
166 0, 0, iter->buf4, iter->buf4size,
167 &bytesReturned, 0, 0) == SOCKET_ERROR)
168 {
169 error = WSAGetLastError();
170 if (error != WSAEFAULT && error != WSAENOBUFS) {
171 errno = error;
172 isc__strerror(error, strbuf, sizeof(strbuf));
173 UNEXPECTED_ERROR(__FILE__, __LINE__,
174 "get interface configuration: %s",
175 strbuf);
176 result = ISC_R_UNEXPECTED;
177 goto ioctl_failure;
178 }
179 /*
180 * EINVAL. Retry with a bigger buffer.
181 */
182 } else {
183 /*
184 * The WSAIoctl succeeded.
185 * If the number of the returned bytes is the same
186 * as the buffer size, we will grow it just in
187 * case and retry.
188 */
189 if (bytesReturned > 0 &&
190 (bytesReturned < iter->buf4size))
191 break;
192 }
193 if (iter->buf4size >= IFCONF_SIZE_MAX*sizeof(INTERFACE_INFO)) {
194 UNEXPECTED_ERROR(__FILE__, __LINE__,
195 "get interface configuration: "
196 "maximum buffer size exceeded");
197 result = ISC_R_UNEXPECTED;
198 goto ioctl_failure;
199 }
200 isc_mem_put(mctx, iter->buf4, iter->buf4size);
201
202 iter->buf4size += IFCONF_SIZE_INCREMENT *
203 sizeof(INTERFACE_INFO);
204 }
205
206 /*
207 * A newly created iterator has an undefined position
208 * until isc_interfaceiter_first() is called.
209 */
210 iter->v4IF = bytesReturned/sizeof(INTERFACE_INFO);
211
212 /* We don't need the socket any more, so close it */
213 closesocket(iter->socket);
214
215 inet6_only:
216 /*
217 * Create an unbound datagram socket to do the
218 * SIO_ADDRESS_LIST_QUERY WSAIoctl on.
219 */
220 iter->socket = socket(AF_INET6, SOCK_DGRAM, 0);
221 if (iter->socket == INVALID_SOCKET) {
222 error = WSAGetLastError();
223 if (error == WSAEAFNOSUPPORT)
224 goto inet_only;
225 isc__strerror(error, strbuf, sizeof(strbuf));
226 UNEXPECTED_ERROR(__FILE__, __LINE__,
227 "making interface scan socket: %s",
228 strbuf);
229 result = ISC_R_UNEXPECTED;
230 goto ioctl_failure;
231 }
232
233 /*
234 * Get the interface configuration, allocating more memory if
235 * necessary.
236 */
237 iter->buf6size = sizeof(SOCKET_ADDRESS_LIST) +
238 IFCONF_SIZE_INITIAL*sizeof(SOCKET_ADDRESS);
239
240 for (;;) {
241 iter->buf6 = isc_mem_get(mctx, iter->buf6size);
242 if (iter->buf6 == NULL) {
243 result = ISC_R_NOMEMORY;
244 goto ioctl_failure;
245 }
246
247 if (WSAIoctl(iter->socket, SIO_ADDRESS_LIST_QUERY,
248 0, 0, iter->buf6, iter->buf6size,
249 &bytesReturned, 0, 0) == SOCKET_ERROR)
250 {
251 error = WSAGetLastError();
252 if (error != WSAEFAULT && error != WSAENOBUFS) {
253 errno = error;
254 isc__strerror(error, strbuf, sizeof(strbuf));
255 UNEXPECTED_ERROR(__FILE__, __LINE__,
256 "sio address list query: %s",
257 strbuf);
258 result = ISC_R_UNEXPECTED;
259 goto ioctl6_failure;
260 }
261 /*
262 * EINVAL. Retry with a bigger buffer.
263 */
264 } else
265 break;
266
267 if (iter->buf6size >= IFCONF_SIZE_MAX*sizeof(SOCKET_ADDRESS)) {
268 UNEXPECTED_ERROR(__FILE__, __LINE__,
269 "get interface configuration: "
270 "maximum buffer size exceeded");
271 result = ISC_R_UNEXPECTED;
272 goto ioctl6_failure;
273 }
274 isc_mem_put(mctx, iter->buf6, iter->buf6size);
275
276 iter->buf6size += IFCONF_SIZE_INCREMENT *
277 sizeof(SOCKET_ADDRESS);
278 }
279
280 closesocket(iter->socket);
281
282 inet_only:
283 iter->magic = IFITER_MAGIC;
284 *iterp = iter;
285 return (ISC_R_SUCCESS);
286
287 ioctl6_failure:
288 isc_mem_put(mctx, iter->buf6, iter->buf6size);
289
290 ioctl_failure:
291 if (iter->buf4 != NULL)
292 isc_mem_put(mctx, iter->buf4, iter->buf4size);
293
294 alloc_failure:
295 if (iter->socket != INVALID_SOCKET)
296 (void) closesocket(iter->socket);
297
298 socket_failure:
299 isc_mem_put(mctx, iter, sizeof(*iter));
300 return (result);
301 }
302
303 /*
304 * Get information about the current interface to iter->current.
305 * If successful, return ISC_R_SUCCESS.
306 * If the interface has an unsupported address family, or if
307 * some operation on it fails, return ISC_R_IGNORE to make
308 * the higher-level iterator code ignore it.
309 */
310
311 static isc_result_t
internal_current(isc_interfaceiter_t * iter)312 internal_current(isc_interfaceiter_t *iter) {
313 BOOL ifNamed = FALSE;
314 unsigned long flags;
315
316 REQUIRE(VALID_IFITER(iter));
317 REQUIRE(iter->numIF >= 0);
318
319 memset(&iter->current, 0, sizeof(iter->current));
320 iter->current.af = AF_INET;
321
322 get_addr(AF_INET, &iter->current.address,
323 (struct sockaddr *)&(iter->IFData.iiAddress));
324
325 /*
326 * Get interface flags.
327 */
328
329 iter->current.flags = 0;
330 flags = iter->IFData.iiFlags;
331
332 if ((flags & IFF_UP) != 0)
333 iter->current.flags |= INTERFACE_F_UP;
334
335 if ((flags & IFF_POINTTOPOINT) != 0) {
336 iter->current.flags |= INTERFACE_F_POINTTOPOINT;
337 snprintf(iter->current.name, sizeof(iter->current.name),
338 "PPP Interface %d", iter->numIF);
339 ifNamed = TRUE;
340 }
341
342 if ((flags & IFF_LOOPBACK) != 0) {
343 iter->current.flags |= INTERFACE_F_LOOPBACK;
344 snprintf(iter->current.name, sizeof(iter->current.name),
345 "Loopback Interface %d", iter->numIF);
346 ifNamed = TRUE;
347 }
348
349 /*
350 * If the interface is point-to-point, get the destination address.
351 */
352 if ((iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0) {
353 get_addr(AF_INET, &iter->current.dstaddress,
354 (struct sockaddr *)&(iter->IFData.iiBroadcastAddress));
355 }
356
357 if (ifNamed == FALSE)
358 snprintf(iter->current.name, sizeof(iter->current.name),
359 "TCP/IP Interface %d", iter->numIF);
360
361 /*
362 * Get the network mask.
363 */
364 get_addr(AF_INET, &iter->current.netmask,
365 (struct sockaddr *)&(iter->IFData.iiNetmask));
366
367 return (ISC_R_SUCCESS);
368 }
369
370 static isc_result_t
internal_current6(isc_interfaceiter_t * iter)371 internal_current6(isc_interfaceiter_t *iter) {
372 SOCKET fd;
373 int i;
374
375 REQUIRE(VALID_IFITER(iter));
376 REQUIRE(iter->buf6 != NULL);
377
378 memset(&iter->current, 0, sizeof(iter->current));
379 iter->current.af = AF_INET6;
380
381 if (!iter->pos6zero) {
382 if (iter->pos6 == 0U)
383 iter->pos6zero = true;
384 get_addr(AF_INET6, &iter->current.address,
385 iter->buf6->Address[iter->pos6].lpSockaddr);
386
387 /*
388 * Set interface flags.
389 */
390
391 iter->current.flags = INTERFACE_F_UP;
392
393 snprintf(iter->current.name, sizeof(iter->current.name),
394 "TCP/IPv6 Interface %u", iter->pos6 + 1);
395
396 for (i = 0; i < 16; i++)
397 iter->current.netmask.type.in6.s6_addr[i] = 0xff;
398 iter->current.netmask.family = AF_INET6;
399 if (IN6_IS_ADDR_LOOPBACK(&iter->current.address.type.in6))
400 iter->v6loop = true;
401 } else {
402 /*
403 * See if we can bind to the ::1 and if so return ::1.
404 */
405 struct sockaddr_in6 sin6;
406
407 iter->v6loop = true; /* So we don't loop forever. */
408
409 fd = socket(AF_INET6, SOCK_DGRAM, 0);
410 if (fd == INVALID_SOCKET)
411 return (ISC_R_IGNORE);
412 memset(&sin6, 0, sizeof(sin6));
413 sin6.sin6_family = AF_INET6;
414 sin6.sin6_addr.s6_addr[15] = 1;
415 if (bind(fd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
416 closesocket(fd);
417 return (ISC_R_IGNORE);
418 }
419 closesocket(fd);
420
421 iter->current.flags = INTERFACE_F_UP | INTERFACE_F_LOOPBACK;
422 snprintf(iter->current.name, sizeof(iter->current.name),
423 "TCP/IPv6 Loopback Interface");
424 for (i = 0; i < 16; i++) {
425 if (i != 15)
426 iter->current.address.type.in6.s6_addr[i] = 0;
427 else
428 iter->current.address.type.in6.s6_addr[i] = 1;
429 iter->current.netmask.type.in6.s6_addr[i] = 0xff;
430 }
431 iter->current.address.family = AF_INET6;
432 iter->current.netmask.family = AF_INET6;
433 }
434 return (ISC_R_SUCCESS);
435 }
436
437 /*
438 * Step the iterator to the next interface. Unlike
439 * isc_interfaceiter_next(), this may leave the iterator
440 * positioned on an interface that will ultimately
441 * be ignored. Return ISC_R_NOMORE if there are no more
442 * interfaces, otherwise ISC_R_SUCCESS.
443 */
444 static isc_result_t
internal_next(isc_interfaceiter_t * iter)445 internal_next(isc_interfaceiter_t *iter) {
446 if (iter->numIF >= iter->v4IF)
447 return (ISC_R_NOMORE);
448
449 /*
450 * The first one needs to be set up to point to the last
451 * Element of the array. Go to the end and back up
452 * Microsoft's implementation is peculiar for returning
453 * the list in reverse order
454 */
455
456 if (iter->numIF == 0)
457 iter->pos4 = (INTERFACE_INFO *)(iter->buf4 + (iter->v4IF));
458
459 iter->pos4--;
460 if (&(iter->pos4) < &(iter->buf4))
461 return (ISC_R_NOMORE);
462
463 memset(&(iter->IFData), 0, sizeof(INTERFACE_INFO));
464 memmove(&(iter->IFData), iter->pos4, sizeof(INTERFACE_INFO));
465 iter->numIF++;
466
467 return (ISC_R_SUCCESS);
468 }
469
470 static isc_result_t
internal_next6(isc_interfaceiter_t * iter)471 internal_next6(isc_interfaceiter_t *iter) {
472 if (iter->pos6 == 0U && iter->v6loop)
473 return (ISC_R_NOMORE);
474 if (iter->pos6 != 0U)
475 iter->pos6--;
476 return (ISC_R_SUCCESS);
477 }
478
479 isc_result_t
isc_interfaceiter_current(isc_interfaceiter_t * iter,isc_interface_t * ifdata)480 isc_interfaceiter_current(isc_interfaceiter_t *iter,
481 isc_interface_t *ifdata) {
482 REQUIRE(iter->result == ISC_R_SUCCESS);
483 memmove(ifdata, &iter->current, sizeof(*ifdata));
484 return (ISC_R_SUCCESS);
485 }
486
487 isc_result_t
isc_interfaceiter_first(isc_interfaceiter_t * iter)488 isc_interfaceiter_first(isc_interfaceiter_t *iter) {
489
490 REQUIRE(VALID_IFITER(iter));
491
492 if (iter->buf6 != NULL) {
493 iter->pos6 = iter->buf6->iAddressCount;
494 iter->v6loop = false;
495 iter->pos6zero = (iter->pos6 == 0U);
496 }
497 iter->result = ISC_R_SUCCESS;
498 return (isc_interfaceiter_next(iter));
499 }
500
501 isc_result_t
isc_interfaceiter_next(isc_interfaceiter_t * iter)502 isc_interfaceiter_next(isc_interfaceiter_t *iter) {
503 isc_result_t result;
504
505 REQUIRE(VALID_IFITER(iter));
506 REQUIRE(iter->result == ISC_R_SUCCESS);
507
508 for (;;) {
509 result = internal_next(iter);
510 if (result == ISC_R_NOMORE) {
511 result = internal_next6(iter);
512 if (result != ISC_R_SUCCESS)
513 break;
514 result = internal_current6(iter);
515 if (result == ISC_R_IGNORE)
516 continue;
517 break;
518 } else if (result != ISC_R_SUCCESS)
519 break;
520 result = internal_current(iter);
521 if (result != ISC_R_IGNORE)
522 break;
523 }
524 iter->result = result;
525 return (result);
526 }
527
528 void
isc_interfaceiter_destroy(isc_interfaceiter_t ** iterp)529 isc_interfaceiter_destroy(isc_interfaceiter_t **iterp) {
530 isc_interfaceiter_t *iter;
531 REQUIRE(iterp != NULL);
532 iter = *iterp;
533 REQUIRE(VALID_IFITER(iter));
534
535 if (iter->buf4 != NULL)
536 isc_mem_put(iter->mctx, iter->buf4, iter->buf4size);
537 if (iter->buf6 != NULL)
538 isc_mem_put(iter->mctx, iter->buf6, iter->buf6size);
539
540 iter->magic = 0;
541 isc_mem_put(iter->mctx, iter, sizeof(*iter));
542 *iterp = NULL;
543 }
544