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Remove ula_compat feature
[project/odhcpd.git] / src / dhcpv6-ia.c
1 /**
2 * Copyright (C) 2013 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include "odhcpd.h"
16 #include "dhcpv6.h"
17 #include "dhcpv4.h"
18 #include "libubox/md5.h"
19
20 #include <time.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <alloca.h>
24 #include <resolv.h>
25 #include <limits.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <arpa/inet.h>
29 #include <sys/timerfd.h>
30
31
32 static void update(struct interface *iface);
33 static void reconf_timer(struct uloop_timeout *event);
34 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
35 static int socket_fd = -1;
36 static uint32_t serial = 0;
37
38
39 int dhcpv6_ia_init(int dhcpv6_socket)
40 {
41 socket_fd = dhcpv6_socket;
42 uloop_timeout_set(&reconf_event, 2000);
43 return 0;
44 }
45
46
47 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
48 {
49 if (!enable && iface->ia_assignments.next) {
50 struct dhcpv6_assignment *c;
51 while (!list_empty(&iface->ia_assignments)) {
52 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
53 list_del(&c->head);
54 free(c->hostname);
55 free(c->classes);
56 free(c);
57 }
58 }
59
60 if (iface->dhcpv6 == RELAYD_SERVER) {
61 if (!iface->ia_assignments.next)
62 INIT_LIST_HEAD(&iface->ia_assignments);
63
64 if (list_empty(&iface->ia_assignments)) {
65 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
66 if (!border) {
67 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
68 return -1;
69 }
70
71 border->length = 64;
72 list_add(&border->head, &iface->ia_assignments);
73 }
74
75 update(iface);
76
77 // Parse static entries
78 struct lease *lease;
79 list_for_each_entry(lease, &leases, head) {
80 // Construct entry
81 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
82 if (!a) {
83 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
84 iface->ifname);
85 return -1;
86 }
87
88 a->clid_len = lease->duid_len;
89 a->length = 128;
90 a->assigned = lease->hostid;
91 odhcpd_urandom(a->key, sizeof(a->key));
92 memcpy(a->clid_data, lease->duid, a->clid_len);
93 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
94
95 // Assign to all interfaces
96 struct dhcpv6_assignment *c;
97 list_for_each_entry(c, &iface->ia_assignments, head) {
98 if (c->length != 128 || c->assigned > a->assigned) {
99 list_add_tail(&a->head, &c->head);
100 } else if (c->assigned == a->assigned) {
101 // Already an assignment with that number
102 break;
103 }
104 }
105
106 if (a->head.next) {
107 if (lease->hostname[0]) {
108 free(a->hostname);
109 a->hostname = strdup(lease->hostname);
110 }
111 } else {
112 free(a->classes);
113 free(a->hostname);
114 free(a);
115 }
116 }
117 }
118 return 0;
119 }
120
121
122 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
123 {
124 struct {
125 struct dhcpv6_client_header hdr;
126 uint16_t srvid_type;
127 uint16_t srvid_len;
128 uint16_t duid_type;
129 uint16_t hardware_type;
130 uint8_t mac[6];
131 uint16_t msg_type;
132 uint16_t msg_len;
133 uint8_t msg_id;
134 struct dhcpv6_auth_reconfigure auth;
135 uint16_t clid_type;
136 uint16_t clid_len;
137 uint8_t clid_data[128];
138 } __attribute__((packed)) reconf_msg = {
139 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
140 .srvid_type = htons(DHCPV6_OPT_SERVERID),
141 .srvid_len = htons(10),
142 .duid_type = htons(3),
143 .hardware_type = htons(1),
144 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
145 .msg_len = htons(1),
146 .msg_id = DHCPV6_MSG_RENEW,
147 .auth = {htons(DHCPV6_OPT_AUTH),
148 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
149 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
150 .clid_type = htons(DHCPV6_OPT_CLIENTID),
151 .clid_len = htons(assign->clid_len),
152 .clid_data = {0},
153 };
154
155 odhcpd_get_mac(iface, reconf_msg.mac);
156 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
157 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
158
159 md5_ctx_t md5;
160 uint8_t secretbytes[16];
161 memcpy(secretbytes, assign->key, sizeof(secretbytes));
162
163 for (size_t i = 0; i < sizeof(secretbytes); ++i)
164 secretbytes[i] ^= 0x36;
165
166 md5_begin(&md5);
167 md5_hash(secretbytes, sizeof(secretbytes), &md5);
168 md5_hash(iov.iov_base, iov.iov_len, &md5);
169 md5_end(reconf_msg.auth.key, &md5);
170
171 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
172 secretbytes[i] ^= 0x36;
173 secretbytes[i] ^= 0x5c;
174 }
175
176 md5_begin(&md5);
177 md5_hash(secretbytes, sizeof(secretbytes), &md5);
178 md5_hash(reconf_msg.auth.key, 16, &md5);
179 md5_end(reconf_msg.auth.key, &md5);
180
181 return odhcpd_send(socket_fd, &assign->peer, &iov, 1, iface);
182 }
183
184
185 void dhcpv6_write_statefile(void)
186 {
187 if (config.dhcp_statefile) {
188 time_t now = odhcpd_time(), wall_time = time(NULL);
189 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
190 if (fd < 0)
191 return;
192
193 lockf(fd, F_LOCK, 0);
194 ftruncate(fd, 0);
195
196 FILE *fp = fdopen(fd, "w");
197 if (!fp) {
198 close(fd);
199 return;
200 }
201
202 struct interface *iface;
203 list_for_each_entry(iface, &interfaces, head) {
204 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
205 continue;
206
207 if (iface->dhcpv6 == RELAYD_SERVER) {
208 struct dhcpv6_assignment *c;
209 list_for_each_entry(c, &iface->ia_assignments, head) {
210 if (c->clid_len == 0)
211 continue;
212
213 char ipbuf[INET6_ADDRSTRLEN];
214 char leasebuf[512];
215 char duidbuf[264];
216 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
217
218 // iface DUID iaid hostname lifetime assigned length [addrs...]
219 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
220 iface->ifname, duidbuf, ntohl(c->iaid),
221 (c->hostname ? c->hostname : "-"),
222 (unsigned)(c->valid_until > now ?
223 (c->valid_until - now + wall_time) : 0),
224 c->assigned, (unsigned)c->length);
225
226 struct in6_addr addr;
227 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
228 if (iface->ia_addr[i].prefix > 64)
229 continue;
230
231 addr = iface->ia_addr[i].addr;
232 if (c->length == 128)
233 addr.s6_addr32[3] = htonl(c->assigned);
234 else
235 addr.s6_addr32[1] |= htonl(c->assigned);
236 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
237
238 if (c->length == 128 && c->hostname && i == 0)
239 fprintf(fp, "%s\t%s\n", ipbuf, c->hostname);
240
241 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%hhu ", ipbuf, c->length);
242 }
243 leasebuf[l - 1] = '\n';
244 fwrite(leasebuf, 1, l, fp);
245 }
246 }
247
248 if (iface->dhcpv4 == RELAYD_SERVER) {
249 struct dhcpv4_assignment *c;
250 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
251 char ipbuf[INET6_ADDRSTRLEN];
252 char leasebuf[512];
253 char duidbuf[16];
254 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
255
256 // iface DUID iaid hostname lifetime assigned length [addrs...]
257 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
258 iface->ifname, duidbuf,
259 (c->hostname ? c->hostname : "-"),
260 (unsigned)(c->valid_until > now ?
261 (c->valid_until - now + wall_time) : 0),
262 c->addr);
263
264 struct in_addr addr = {htonl(c->addr)};
265 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
266
267 if (c->hostname[0])
268 fprintf(fp, "%s\t%s\n", ipbuf, c->hostname);
269
270 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
271 leasebuf[l - 1] = '\n';
272 fwrite(leasebuf, 1, l, fp);
273 }
274 }
275 }
276
277 fclose(fp);
278 }
279
280 if (config.dhcp_cb) {
281 char *argv[2] = {config.dhcp_cb, NULL};
282 if (!vfork()) {
283 execv(argv[0], argv);
284 _exit(128);
285 }
286 }
287 }
288
289
290 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
291 {
292 if (a->length > 64)
293 return;
294
295 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
296 struct in6_addr prefix = iface->ia_addr[i].addr;
297 prefix.s6_addr32[1] |= htonl(a->assigned);
298 odhcpd_setup_route(&prefix, a->length, iface, &a->peer.sin6_addr, add);
299 }
300 }
301
302
303 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
304 {
305 struct dhcpv6_assignment *c;
306 if (iface->ia_addr_len < 1)
307 return false;
308
309 // Try honoring the hint first
310 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
311 if (assign->assigned) {
312 list_for_each_entry(c, &iface->ia_assignments, head) {
313 if (c->length == 128)
314 continue;
315
316 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
317 list_add_tail(&assign->head, &c->head);
318 apply_lease(iface, assign, true);
319 return true;
320 }
321
322 if (c->assigned != 0)
323 current = (c->assigned + (1 << (64 - c->length)));
324 }
325 }
326
327 // Fallback to a variable assignment
328 current = 1;
329 list_for_each_entry(c, &iface->ia_assignments, head) {
330 if (c->length == 128)
331 continue;
332
333 current = (current + asize) & (~asize);
334 if (current + asize < c->assigned) {
335 assign->assigned = current;
336 list_add_tail(&assign->head, &c->head);
337 apply_lease(iface, assign, true);
338 return true;
339 }
340
341 if (c->assigned != 0)
342 current = (c->assigned + (1 << (64 - c->length)));
343 }
344
345 return false;
346 }
347
348
349 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
350 {
351 bool match = false;
352 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
353 if (!iface->ia_addr[i].has_class) {
354 match = true;
355 continue;
356 } else if (assign->classes_cnt) {
357 for (size_t j = 0; j < assign->classes_cnt; ++j)
358 if (assign->classes[j] == iface->ia_addr[i].class)
359 match = true;
360 } else if (assign->all_class) {
361 match = true;
362 }
363 }
364
365 if (!match)
366 return false;
367
368 // Seed RNG with checksum of DUID
369 uint32_t seed = 0;
370 for (size_t i = 0; i < assign->clid_len; ++i)
371 seed += assign->clid_data[i];
372 srand(seed);
373
374 // Try to assign up to 100x
375 for (size_t i = 0; i < 100; ++i) {
376 uint32_t try;
377 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
378
379 struct dhcpv6_assignment *c;
380 list_for_each_entry(c, &iface->ia_assignments, head) {
381 if (c->assigned > try || c->length != 128) {
382 assign->assigned = try;
383 list_add_tail(&assign->head, &c->head);
384 return true;
385 } else if (c->assigned == try) {
386 break;
387 }
388 }
389 }
390
391 return false;
392 }
393
394
395 static int prefixcmp(const void *va, const void *vb)
396 {
397 const struct odhcpd_ipaddr *a = va, *b = vb;
398 uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
399 uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
400 return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
401 }
402
403
404 static void update(struct interface *iface)
405 {
406 struct odhcpd_ipaddr addr[8];
407 memset(addr, 0, sizeof(addr));
408 int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
409
410 if (len < 0)
411 return;
412
413 qsort(addr, len, sizeof(*addr), prefixcmp);
414
415 time_t now = odhcpd_time();
416 int minprefix = -1;
417
418 for (int i = 0; i < len; ++i) {
419 if (addr[i].prefix > minprefix)
420 minprefix = addr[i].prefix;
421
422 addr[i].addr.s6_addr32[2] = 0;
423 addr[i].addr.s6_addr32[3] = 0;
424
425 if (addr[i].preferred < UINT32_MAX - now)
426 addr[i].preferred += now;
427
428 if (addr[i].valid < UINT32_MAX - now)
429 addr[i].valid += now;
430 }
431
432 struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
433 border->assigned = 1 << (64 - minprefix);
434
435 bool change = len != (int)iface->ia_addr_len;
436 for (int i = 0; !change && i < len; ++i)
437 if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
438 addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
439 (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
440 (addr[i].valid > (uint32_t)now + 7200) !=
441 (iface->ia_addr[i].valid > (uint32_t)now + 7200))
442 change = true;
443
444 if (change) {
445 struct dhcpv6_assignment *c;
446 list_for_each_entry(c, &iface->ia_assignments, head)
447 if (c != border)
448 apply_lease(iface, c, false);
449 }
450
451 memcpy(iface->ia_addr, addr, len * sizeof(*addr));
452 iface->ia_addr_len = len;
453
454 if (change) { // Addresses / prefixes have changed
455 struct list_head reassign = LIST_HEAD_INIT(reassign);
456 struct dhcpv6_assignment *c, *d;
457 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
458 if (c->clid_len == 0 || c->valid_until < now)
459 continue;
460
461 if (c->length < 128 && c->assigned >= border->assigned && c != border)
462 list_move(&c->head, &reassign);
463 else if (c != border)
464 apply_lease(iface, c, true);
465
466 if (c->accept_reconf && c->reconf_cnt == 0) {
467 c->reconf_cnt = 1;
468 c->reconf_sent = now;
469 send_reconf(iface, c);
470
471 // Leave all other assignments of that client alone
472 struct dhcpv6_assignment *a;
473 list_for_each_entry(a, &iface->ia_assignments, head)
474 if (a != c && a->clid_len == c->clid_len &&
475 !memcmp(a->clid_data, c->clid_data, a->clid_len))
476 c->reconf_cnt = INT_MAX;
477 }
478 }
479
480 while (!list_empty(&reassign)) {
481 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
482 list_del(&c->head);
483 if (!assign_pd(iface, c)) {
484 c->assigned = 0;
485 list_add(&c->head, &iface->ia_assignments);
486 }
487 }
488
489 dhcpv6_write_statefile();
490 }
491 }
492
493
494 static void reconf_timer(struct uloop_timeout *event)
495 {
496 time_t now = odhcpd_time();
497 struct interface *iface;
498 list_for_each_entry(iface, &interfaces, head) {
499 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
500 continue;
501
502 struct dhcpv6_assignment *a, *n;
503 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
504 if (a->valid_until < now) {
505 if ((a->length < 128 && a->clid_len > 0) ||
506 (a->length == 128 && a->clid_len == 0)) {
507 list_del(&a->head);
508 free(a->classes);
509 free(a->hostname);
510 free(a);
511 }
512 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
513 now > a->reconf_sent + (1 << a->reconf_cnt)) {
514 ++a->reconf_cnt;
515 a->reconf_sent = now;
516 send_reconf(iface, a);
517 }
518 }
519
520 if (iface->ia_reconf) {
521 update(iface);
522 iface->ia_reconf = false;
523 }
524 }
525
526 uloop_timeout_set(event, 2000);
527 }
528
529
530 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
531 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
532 struct interface *iface, bool request)
533 {
534 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
535 return 0;
536
537 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
538 size_t datalen = sizeof(out);
539 time_t now = odhcpd_time();
540
541 if (status) {
542 struct __attribute__((packed)) {
543 uint16_t type;
544 uint16_t len;
545 uint16_t value;
546 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
547 htons(status)};
548
549 memcpy(buf + datalen, &stat, sizeof(stat));
550 datalen += sizeof(stat);
551 } else {
552 if (a) {
553 uint32_t pref = 3600;
554 uint32_t valid = 3600;
555
556 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
557 bool match = true;
558 if (iface->ia_addr[i].has_class) {
559 match = false;
560 if (a->classes_cnt) {
561 for (size_t j = 0; j < a->classes_cnt; ++j)
562 if (a->classes[j] == iface->ia_addr[i].class)
563 match = true;
564 } else if (a->all_class) {
565 match = true;
566 }
567 }
568
569 if (!match)
570 continue;
571
572 uint32_t prefix_pref = iface->ia_addr[i].preferred - now;
573 uint32_t prefix_valid = iface->ia_addr[i].valid - now;
574
575 if (iface->ia_addr[i].prefix > 64 ||
576 iface->ia_addr[i].preferred <= (uint32_t)now)
577 continue;
578
579 if (prefix_pref > 86400)
580 prefix_pref = 86400;
581
582 if (prefix_valid > 86400)
583 prefix_valid = 86400;
584
585 #ifdef DHCPV6_OPT_PREFIX_CLASS
586 struct {
587 uint16_t code;
588 uint16_t length;
589 uint16_t class;
590 } pclass = {htons(DHCPV6_OPT_PREFIX_CLASS),
591 htons(2), htons(iface->ia_addr[i].class)};
592 #endif
593
594 if (a->length < 128) {
595 struct dhcpv6_ia_prefix p = {
596 .type = htons(DHCPV6_OPT_IA_PREFIX),
597 .len = htons(sizeof(p) - 4),
598 .preferred = htonl(prefix_pref),
599 .valid = htonl(prefix_valid),
600 .prefix = a->length,
601 .addr = iface->ia_addr[i].addr
602 };
603 p.addr.s6_addr32[1] |= htonl(a->assigned);
604 size_t entrlen = sizeof(p) - 4;
605
606 #ifdef DHCPV6_OPT_PREFIX_CLASS
607 if (iface->ia_addr[i].has_class) {
608 entrlen += sizeof(pclass);
609 p.len = htons(entrlen);
610 }
611 #endif
612
613 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
614 continue;
615
616 memcpy(buf + datalen, &p, sizeof(p));
617 #ifdef DHCPV6_OPT_PREFIX_CLASS
618 memcpy(buf + datalen + sizeof(p), &pclass, sizeof(pclass));
619 #endif
620 datalen += entrlen + 4;
621 } else {
622 struct dhcpv6_ia_addr n = {
623 .type = htons(DHCPV6_OPT_IA_ADDR),
624 .len = htons(sizeof(n) - 4),
625 .addr = iface->ia_addr[i].addr,
626 .preferred = htonl(prefix_pref),
627 .valid = htonl(prefix_valid)
628 };
629 n.addr.s6_addr32[3] = htonl(a->assigned);
630 size_t entrlen = sizeof(n) - 4;
631
632 #ifdef DHCPV6_OPT_PREFIX_CLASS
633 if (iface->ia_addr[i].has_class) {
634 entrlen += sizeof(pclass);
635 n.len = htons(entrlen);
636 }
637 #endif
638
639 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
640 continue;
641
642 memcpy(buf + datalen, &n, sizeof(n));
643 #ifdef DHCPV6_OPT_PREFIX_CLASS
644 memcpy(buf + datalen + sizeof(n), &pclass, sizeof(pclass));
645 #endif
646 datalen += entrlen + 4;
647 }
648
649 // Calculate T1 / T2 based on non-deprecated addresses
650 if (prefix_pref > 0) {
651 if (prefix_pref < pref)
652 pref = prefix_pref;
653
654 if (prefix_valid < valid)
655 valid = prefix_valid;
656 }
657 }
658
659 a->valid_until = valid + now;
660 out.t1 = htonl(pref * 5 / 10);
661 out.t2 = htonl(pref * 8 / 10);
662
663 if (!out.t1)
664 out.t1 = htonl(1);
665
666 if (!out.t2)
667 out.t2 = htonl(1);
668 }
669
670 if (!request) {
671 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
672 uint16_t otype, olen;
673 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
674 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
675 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
676 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
677 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
678 continue;
679
680 bool found = false;
681 if (a) {
682 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
683 if (iface->ia_addr[i].prefix > 64 ||
684 iface->ia_addr[i].preferred <= (uint32_t)now)
685 continue;
686
687 struct in6_addr addr = iface->ia_addr[i].addr;
688 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
689 addr.s6_addr32[1] |= htonl(a->assigned);
690
691 if (IN6_ARE_ADDR_EQUAL(&p->addr, &addr) &&
692 p->prefix == a->length)
693 found = true;
694 } else {
695 addr.s6_addr32[3] = htonl(a->assigned);
696
697 if (IN6_ARE_ADDR_EQUAL(&n->addr, &addr))
698 found = true;
699 }
700 }
701 }
702
703 if (!found) {
704 if (otype == DHCPV6_OPT_IA_PREFIX) {
705 struct dhcpv6_ia_prefix inv = {
706 .type = htons(DHCPV6_OPT_IA_PREFIX),
707 .len = htons(sizeof(inv) - 4),
708 .preferred = 0,
709 .valid = 0,
710 .prefix = p->prefix,
711 .addr = p->addr
712 };
713
714 if (datalen + sizeof(inv) > buflen)
715 continue;
716
717 memcpy(buf + datalen, &inv, sizeof(inv));
718 datalen += sizeof(inv);
719 } else {
720 struct dhcpv6_ia_addr inv = {
721 .type = htons(DHCPV6_OPT_IA_ADDR),
722 .len = htons(sizeof(inv) - 4),
723 .addr = n->addr,
724 .preferred = 0,
725 .valid = 0
726 };
727
728 if (datalen + sizeof(inv) > buflen)
729 continue;
730
731 memcpy(buf + datalen, &inv, sizeof(inv));
732 datalen += sizeof(inv);
733 }
734 }
735 }
736 }
737 }
738
739 out.len = htons(datalen - 4);
740 memcpy(buf, &out, sizeof(out));
741 return datalen;
742 }
743
744
745 size_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
746 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
747 {
748 time_t now = odhcpd_time();
749 size_t response_len = 0;
750 const struct dhcpv6_client_header *hdr = data;
751 uint8_t *start = (uint8_t*)&hdr[1], *odata;
752 uint16_t otype, olen;
753
754 // Find and parse client-id and hostname
755 bool accept_reconf = false;
756 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
757 char hostname[256];
758 size_t hostname_len = 0;
759 bool class_oro = false;
760 dhcpv6_for_each_option(start, end, otype, olen, odata) {
761 if (otype == DHCPV6_OPT_CLIENTID) {
762 clid_data = odata;
763 clid_len = olen;
764
765 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
766 memcpy(mac, &odata[8], sizeof(mac));
767 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
768 memcpy(mac, &odata[4], sizeof(mac));
769 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
770 uint8_t fqdn_buf[256];
771 memcpy(fqdn_buf, odata, olen);
772 fqdn_buf[olen++] = 0;
773
774 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
775 hostname_len = strcspn(hostname, ".");
776 } else if (otype == DHCPV6_OPT_ORO) {
777 #ifdef DHCPV6_OPT_PREFIX_CLASS
778 for (size_t i = 0; i + 1 < olen; i += 2) {
779 if (odata[i] == (DHCPV6_OPT_PREFIX_CLASS >> 8) &&
780 odata[i + 1] == (DHCPV6_OPT_PREFIX_CLASS & 0xff))
781 class_oro = true;
782 }
783 #endif
784 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
785 accept_reconf = true;
786 }
787 }
788
789 if (!clid_data || !clid_len || clid_len > 130)
790 goto out;
791
792 update(iface);
793 bool update_state = false;
794
795 struct dhcpv6_assignment *first = NULL;
796 dhcpv6_for_each_option(start, end, otype, olen, odata) {
797 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
798 bool is_na = (otype == DHCPV6_OPT_IA_NA);
799 if (!is_pd && !is_na)
800 continue;
801
802 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
803 size_t ia_response_len = 0;
804 uint8_t reqlen = (is_pd) ? 62 : 128;
805 uint32_t reqhint = 0;
806
807 const uint8_t classes_max = 32;
808 uint8_t classes_cnt = 0;
809 uint16_t classes[classes_max];
810
811 // Parse request hint for IA-PD
812 if (is_pd) {
813 uint8_t *sdata;
814 uint16_t stype, slen;
815 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
816 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
817 continue;
818
819 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
820 if (p->prefix) {
821 reqlen = p->prefix;
822 reqhint = ntohl(p->addr.s6_addr32[1]);
823 if (reqlen > 32 && reqlen <= 64)
824 reqhint &= (1U << (64 - reqlen)) - 1;
825 }
826
827 #ifdef DHCPV6_OPT_PREFIX_CLASS
828 uint8_t *xdata;
829 uint16_t xtype, xlen;
830 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
831 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
832 continue;
833
834 if (classes_cnt >= classes_max)
835 continue;
836
837 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
838 }
839 #endif
840 }
841
842 if (reqlen > 64)
843 reqlen = 64;
844 } else if (is_na) {
845 uint8_t *sdata;
846 uint16_t stype, slen;
847 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
848 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
849 continue;
850
851 #ifdef DHCPV6_OPT_PREFIX_CLASS
852 uint8_t *xdata;
853 uint16_t xtype, xlen;
854 struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
855 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
856 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
857 continue;
858
859 if (classes_cnt >= classes_max)
860 continue;
861
862 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
863 }
864 #endif
865 }
866 }
867
868 // Find assignment
869 struct dhcpv6_assignment *c, *a = NULL;
870 list_for_each_entry(c, &iface->ia_assignments, head) {
871 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
872 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
873 && !memcmp(c->mac, mac, sizeof(mac)))) &&
874 (c->iaid == ia->iaid || c->valid_until < now) &&
875 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
876 a = c;
877
878 // Reset state
879 apply_lease(iface, a, false);
880 memcpy(a->clid_data, clid_data, clid_len);
881 a->clid_len = clid_len;
882 a->iaid = ia->iaid;
883 a->peer = *addr;
884 a->reconf_cnt = 0;
885 a->reconf_sent = 0;
886 a->all_class = class_oro;
887 a->classes_cnt = classes_cnt;
888 a->classes = realloc(a->classes, classes_cnt * sizeof(uint16_t));
889 if (a->classes)
890 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
891 break;
892 }
893 }
894
895 // Generic message handling
896 uint16_t status = DHCPV6_STATUS_OK;
897 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
898 bool assigned = !!a;
899
900 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
901 a = calloc(1, sizeof(*a) + clid_len);
902 if (a) {
903 a->clid_len = clid_len;
904 a->iaid = ia->iaid;
905 a->length = reqlen;
906 a->peer = *addr;
907 a->assigned = reqhint;
908 a->all_class = class_oro;
909 a->classes_cnt = classes_cnt;
910 if (classes_cnt) {
911 a->classes = malloc(classes_cnt * sizeof(uint16_t));
912 if (a->classes)
913 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
914 }
915
916 if (first)
917 memcpy(a->key, first->key, sizeof(a->key));
918 else
919 odhcpd_urandom(a->key, sizeof(a->key));
920 memcpy(a->clid_data, clid_data, clid_len);
921
922 if (is_pd)
923 while (!(assigned = assign_pd(iface, a)) && ++a->length <= 64);
924 else
925 assigned = assign_na(iface, a);
926 }
927 }
928
929 if (!assigned || iface->ia_addr_len == 0) { // Set error status
930 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
931 } else if (assigned && !first) { //
932 size_t handshake_len = 4;
933 buf[0] = 0;
934 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
935 buf[2] = 0;
936 buf[3] = 0;
937
938 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
939 struct dhcpv6_auth_reconfigure auth = {
940 htons(DHCPV6_OPT_AUTH),
941 htons(sizeof(auth) - 4),
942 3, 1, 0,
943 {htonl(time(NULL)), htonl(++serial)},
944 1,
945 {0}
946 };
947 memcpy(auth.key, a->key, sizeof(a->key));
948 memcpy(buf + handshake_len, &auth, sizeof(auth));
949 handshake_len += sizeof(auth);
950 }
951
952 buf += handshake_len;
953 buflen -= handshake_len;
954 response_len += handshake_len;
955
956 first = a;
957 }
958
959 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
960
961 // Was only a solicitation: mark binding for removal
962 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
963 a->valid_until = 0;
964 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
965 if (hostname_len > 0) {
966 a->hostname = realloc(a->hostname, hostname_len + 1);
967 if (a->hostname) {
968 memcpy(a->hostname, hostname, hostname_len);
969 a->hostname[hostname_len] = 0;
970 }
971 }
972 a->accept_reconf = accept_reconf;
973 apply_lease(iface, a, true);
974 update_state = true;
975 } else if (!assigned && a) { // Cleanup failed assignment
976 free(a->classes);
977 free(a->hostname);
978 free(a);
979 }
980 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
981 hdr->msg_type == DHCPV6_MSG_RELEASE ||
982 hdr->msg_type == DHCPV6_MSG_REBIND ||
983 hdr->msg_type == DHCPV6_MSG_DECLINE) {
984 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
985 status = DHCPV6_STATUS_NOBINDING;
986 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
987 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
988 hdr->msg_type == DHCPV6_MSG_REBIND) {
989 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
990 if (a)
991 apply_lease(iface, a, true);
992 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
993 a->valid_until = 0;
994 apply_lease(iface, a, false);
995 update_state = true;
996 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
997 a->clid_len = 0;
998 a->valid_until = now + 3600; // Block address for 1h
999 update_state = true;
1000 }
1001 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1002 // Always send NOTONLINK for CONFIRM so that clients restart connection
1003 status = DHCPV6_STATUS_NOTONLINK;
1004 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1005 }
1006
1007 buf += ia_response_len;
1008 buflen -= ia_response_len;
1009 response_len += ia_response_len;
1010 }
1011
1012 if (hdr->msg_type == DHCPV6_MSG_RELEASE && response_len + 6 < buflen) {
1013 buf[0] = 0;
1014 buf[1] = DHCPV6_OPT_STATUS;
1015 buf[2] = 0;
1016 buf[3] = 2;
1017 buf[4] = 0;
1018 buf[5] = DHCPV6_STATUS_OK;
1019 response_len += 6;
1020 }
1021
1022 if (update_state)
1023 dhcpv6_write_statefile();
1024
1025 out:
1026 return response_len;
1027 }
OpenWrt DHCP Server