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Merge pull request #3 from dedeckeh/master
[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 "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 bool have_non_ula = false;
556 for (size_t i = 0; i < iface->ia_addr_len; ++i)
557 if ((iface->ia_addr[i].addr.s6_addr[0] & 0xfe) != 0xfc)
558 have_non_ula = true;
559
560 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
561 bool match = true;
562 if (iface->ia_addr[i].has_class) {
563 match = false;
564 if (a->classes_cnt) {
565 for (size_t j = 0; j < a->classes_cnt; ++j)
566 if (a->classes[j] == iface->ia_addr[i].class)
567 match = true;
568 } else if (a->all_class) {
569 match = true;
570 }
571 }
572
573 if (!match)
574 continue;
575
576 uint32_t prefix_pref = iface->ia_addr[i].preferred - now;
577 uint32_t prefix_valid = iface->ia_addr[i].valid - now;
578
579 if (iface->ia_addr[i].prefix > 64 ||
580 iface->ia_addr[i].preferred <= (uint32_t)now)
581 continue;
582
583 // ULA-deprecation compatibility workaround
584 if ((iface->ia_addr[i].addr.s6_addr[0] & 0xfe) == 0xfc &&
585 a->length == 128 && have_non_ula &&
586 iface->deprecate_ula_if_public_avail)
587 continue;
588
589 if (prefix_pref > 86400)
590 prefix_pref = 86400;
591
592 if (prefix_valid > 86400)
593 prefix_valid = 86400;
594
595 #ifdef DHCPV6_OPT_PREFIX_CLASS
596 struct {
597 uint16_t code;
598 uint16_t length;
599 uint16_t class;
600 } pclass = {htons(DHCPV6_OPT_PREFIX_CLASS),
601 htons(2), htons(iface->ia_addr[i].class)};
602 #endif
603
604 if (a->length < 128) {
605 struct dhcpv6_ia_prefix p = {
606 .type = htons(DHCPV6_OPT_IA_PREFIX),
607 .len = htons(sizeof(p) - 4),
608 .preferred = htonl(prefix_pref),
609 .valid = htonl(prefix_valid),
610 .prefix = a->length,
611 .addr = iface->ia_addr[i].addr
612 };
613 p.addr.s6_addr32[1] |= htonl(a->assigned);
614 size_t entrlen = sizeof(p) - 4;
615
616 #ifdef DHCPV6_OPT_PREFIX_CLASS
617 if (iface->ia_addr[i].has_class) {
618 entrlen += sizeof(pclass);
619 p.len = htons(entrlen);
620 }
621 #endif
622
623 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
624 continue;
625
626 memcpy(buf + datalen, &p, sizeof(p));
627 #ifdef DHCPV6_OPT_PREFIX_CLASS
628 memcpy(buf + datalen + sizeof(p), &pclass, sizeof(pclass));
629 #endif
630 datalen += entrlen + 4;
631 } else {
632 struct dhcpv6_ia_addr n = {
633 .type = htons(DHCPV6_OPT_IA_ADDR),
634 .len = htons(sizeof(n) - 4),
635 .addr = iface->ia_addr[i].addr,
636 .preferred = htonl(prefix_pref),
637 .valid = htonl(prefix_valid)
638 };
639 n.addr.s6_addr32[3] = htonl(a->assigned);
640 size_t entrlen = sizeof(n) - 4;
641
642 #ifdef DHCPV6_OPT_PREFIX_CLASS
643 if (iface->ia_addr[i].has_class) {
644 entrlen += sizeof(pclass);
645 n.len = htons(entrlen);
646 }
647 #endif
648
649 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
650 continue;
651
652 memcpy(buf + datalen, &n, sizeof(n));
653 #ifdef DHCPV6_OPT_PREFIX_CLASS
654 memcpy(buf + datalen + sizeof(n), &pclass, sizeof(pclass));
655 #endif
656 datalen += entrlen + 4;
657 }
658
659 // Calculate T1 / T2 based on non-deprecated addresses
660 if (prefix_pref > 0) {
661 if (prefix_pref < pref)
662 pref = prefix_pref;
663
664 if (prefix_valid < valid)
665 valid = prefix_valid;
666 }
667 }
668
669 a->valid_until = valid + now;
670 out.t1 = htonl(pref * 5 / 10);
671 out.t2 = htonl(pref * 8 / 10);
672
673 if (!out.t1)
674 out.t1 = htonl(1);
675
676 if (!out.t2)
677 out.t2 = htonl(1);
678 }
679
680 if (!request) {
681 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
682 uint16_t otype, olen;
683 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
684 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
685 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
686 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
687 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
688 continue;
689
690 bool found = false;
691 if (a) {
692 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
693 if (iface->ia_addr[i].prefix > 64 ||
694 iface->ia_addr[i].preferred <= (uint32_t)now)
695 continue;
696
697 struct in6_addr addr = iface->ia_addr[i].addr;
698 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
699 addr.s6_addr32[1] |= htonl(a->assigned);
700
701 if (IN6_ARE_ADDR_EQUAL(&p->addr, &addr) &&
702 p->prefix == a->length)
703 found = true;
704 } else {
705 addr.s6_addr32[3] = htonl(a->assigned);
706
707 if (IN6_ARE_ADDR_EQUAL(&n->addr, &addr))
708 found = true;
709 }
710 }
711 }
712
713 if (!found) {
714 if (otype == DHCPV6_OPT_IA_PREFIX) {
715 struct dhcpv6_ia_prefix inv = {
716 .type = htons(DHCPV6_OPT_IA_PREFIX),
717 .len = htons(sizeof(inv) - 4),
718 .preferred = 0,
719 .valid = 0,
720 .prefix = p->prefix,
721 .addr = p->addr
722 };
723
724 if (datalen + sizeof(inv) > buflen)
725 continue;
726
727 memcpy(buf + datalen, &inv, sizeof(inv));
728 datalen += sizeof(inv);
729 } else {
730 struct dhcpv6_ia_addr inv = {
731 .type = htons(DHCPV6_OPT_IA_ADDR),
732 .len = htons(sizeof(inv) - 4),
733 .addr = n->addr,
734 .preferred = 0,
735 .valid = 0
736 };
737
738 if (datalen + sizeof(inv) > buflen)
739 continue;
740
741 memcpy(buf + datalen, &inv, sizeof(inv));
742 datalen += sizeof(inv);
743 }
744 }
745 }
746 }
747 }
748
749 out.len = htons(datalen - 4);
750 memcpy(buf, &out, sizeof(out));
751 return datalen;
752 }
753
754
755 size_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
756 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
757 {
758 time_t now = odhcpd_time();
759 size_t response_len = 0;
760 const struct dhcpv6_client_header *hdr = data;
761 uint8_t *start = (uint8_t*)&hdr[1], *odata;
762 uint16_t otype, olen;
763
764 // Find and parse client-id and hostname
765 bool accept_reconf = false;
766 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
767 char hostname[256];
768 size_t hostname_len = 0;
769 bool class_oro = false;
770 dhcpv6_for_each_option(start, end, otype, olen, odata) {
771 if (otype == DHCPV6_OPT_CLIENTID) {
772 clid_data = odata;
773 clid_len = olen;
774
775 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
776 memcpy(mac, &odata[8], sizeof(mac));
777 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
778 memcpy(mac, &odata[4], sizeof(mac));
779 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
780 uint8_t fqdn_buf[256];
781 memcpy(fqdn_buf, odata, olen);
782 fqdn_buf[olen++] = 0;
783
784 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
785 hostname_len = strcspn(hostname, ".");
786 } else if (otype == DHCPV6_OPT_ORO) {
787 #ifdef DHCPV6_OPT_PREFIX_CLASS
788 for (size_t i = 0; i + 1 < olen; i += 2) {
789 if (odata[i] == (DHCPV6_OPT_PREFIX_CLASS >> 8) &&
790 odata[i + 1] == (DHCPV6_OPT_PREFIX_CLASS & 0xff))
791 class_oro = true;
792 }
793 #endif
794 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
795 accept_reconf = true;
796 }
797 }
798
799 if (!clid_data || !clid_len || clid_len > 130)
800 goto out;
801
802 update(iface);
803 bool update_state = false;
804
805 struct dhcpv6_assignment *first = NULL;
806 dhcpv6_for_each_option(start, end, otype, olen, odata) {
807 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
808 bool is_na = (otype == DHCPV6_OPT_IA_NA);
809 if (!is_pd && !is_na)
810 continue;
811
812 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
813 size_t ia_response_len = 0;
814 uint8_t reqlen = (is_pd) ? 62 : 128;
815 uint32_t reqhint = 0;
816
817 const uint8_t classes_max = 32;
818 uint8_t classes_cnt = 0;
819 uint16_t classes[classes_max];
820
821 // Parse request hint for IA-PD
822 if (is_pd) {
823 uint8_t *sdata;
824 uint16_t stype, slen;
825 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
826 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
827 continue;
828
829 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
830 if (p->prefix) {
831 reqlen = p->prefix;
832 reqhint = ntohl(p->addr.s6_addr32[1]);
833 if (reqlen > 32 && reqlen <= 64)
834 reqhint &= (1U << (64 - reqlen)) - 1;
835 }
836
837 #ifdef DHCPV6_OPT_PREFIX_CLASS
838 uint8_t *xdata;
839 uint16_t xtype, xlen;
840 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
841 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
842 continue;
843
844 if (classes_cnt >= classes_max)
845 continue;
846
847 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
848 }
849 #endif
850 }
851
852 if (reqlen > 64)
853 reqlen = 64;
854 } else if (is_na) {
855 uint8_t *sdata;
856 uint16_t stype, slen;
857 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
858 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
859 continue;
860
861 #ifdef DHCPV6_OPT_PREFIX_CLASS
862 uint8_t *xdata;
863 uint16_t xtype, xlen;
864 struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
865 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
866 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
867 continue;
868
869 if (classes_cnt >= classes_max)
870 continue;
871
872 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
873 }
874 #endif
875 }
876 }
877
878 // Find assignment
879 struct dhcpv6_assignment *c, *a = NULL;
880 list_for_each_entry(c, &iface->ia_assignments, head) {
881 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
882 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
883 && !memcmp(c->mac, mac, sizeof(mac)))) &&
884 (c->iaid == ia->iaid || c->valid_until < now) &&
885 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
886 a = c;
887
888 // Reset state
889 apply_lease(iface, a, false);
890 memcpy(a->clid_data, clid_data, clid_len);
891 a->clid_len = clid_len;
892 a->iaid = ia->iaid;
893 a->peer = *addr;
894 a->reconf_cnt = 0;
895 a->reconf_sent = 0;
896 a->all_class = class_oro;
897 a->classes_cnt = classes_cnt;
898 a->classes = realloc(a->classes, classes_cnt * sizeof(uint16_t));
899 if (a->classes)
900 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
901 break;
902 }
903 }
904
905 // Generic message handling
906 uint16_t status = DHCPV6_STATUS_OK;
907 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
908 bool assigned = !!a;
909
910 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
911 a = calloc(1, sizeof(*a) + clid_len);
912 if (a) {
913 a->clid_len = clid_len;
914 a->iaid = ia->iaid;
915 a->length = reqlen;
916 a->peer = *addr;
917 a->assigned = reqhint;
918 a->all_class = class_oro;
919 a->classes_cnt = classes_cnt;
920 if (classes_cnt) {
921 a->classes = malloc(classes_cnt * sizeof(uint16_t));
922 if (a->classes)
923 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
924 }
925
926 if (first)
927 memcpy(a->key, first->key, sizeof(a->key));
928 else
929 odhcpd_urandom(a->key, sizeof(a->key));
930 memcpy(a->clid_data, clid_data, clid_len);
931
932 if (is_pd)
933 while (!(assigned = assign_pd(iface, a)) && ++a->length <= 64);
934 else
935 assigned = assign_na(iface, a);
936 }
937 }
938
939 if (!assigned || iface->ia_addr_len == 0) { // Set error status
940 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
941 } else if (assigned && !first) { //
942 size_t handshake_len = 4;
943 buf[0] = 0;
944 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
945 buf[2] = 0;
946 buf[3] = 0;
947
948 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
949 struct dhcpv6_auth_reconfigure auth = {
950 htons(DHCPV6_OPT_AUTH),
951 htons(sizeof(auth) - 4),
952 3, 1, 0,
953 {htonl(time(NULL)), htonl(++serial)},
954 1,
955 {0}
956 };
957 memcpy(auth.key, a->key, sizeof(a->key));
958 memcpy(buf + handshake_len, &auth, sizeof(auth));
959 handshake_len += sizeof(auth);
960 }
961
962 buf += handshake_len;
963 buflen -= handshake_len;
964 response_len += handshake_len;
965
966 first = a;
967 }
968
969 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
970
971 // Was only a solicitation: mark binding for removal
972 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
973 a->valid_until = 0;
974 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
975 if (hostname_len > 0) {
976 a->hostname = realloc(a->hostname, hostname_len + 1);
977 if (a->hostname) {
978 memcpy(a->hostname, hostname, hostname_len);
979 a->hostname[hostname_len] = 0;
980 }
981 }
982 a->accept_reconf = accept_reconf;
983 apply_lease(iface, a, true);
984 update_state = true;
985 } else if (!assigned && a) { // Cleanup failed assignment
986 free(a->classes);
987 free(a->hostname);
988 free(a);
989 }
990 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
991 hdr->msg_type == DHCPV6_MSG_RELEASE ||
992 hdr->msg_type == DHCPV6_MSG_REBIND ||
993 hdr->msg_type == DHCPV6_MSG_DECLINE) {
994 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
995 status = DHCPV6_STATUS_NOBINDING;
996 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
997 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
998 hdr->msg_type == DHCPV6_MSG_REBIND) {
999 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1000 if (a)
1001 apply_lease(iface, a, true);
1002 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1003 a->valid_until = 0;
1004 apply_lease(iface, a, false);
1005 update_state = true;
1006 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1007 a->clid_len = 0;
1008 a->valid_until = now + 3600; // Block address for 1h
1009 update_state = true;
1010 }
1011 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1012 // Always send NOTONLINK for CONFIRM so that clients restart connection
1013 status = DHCPV6_STATUS_NOTONLINK;
1014 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1015 }
1016
1017 buf += ia_response_len;
1018 buflen -= ia_response_len;
1019 response_len += ia_response_len;
1020 }
1021
1022 if (hdr->msg_type == DHCPV6_MSG_RELEASE && response_len + 6 < buflen) {
1023 buf[0] = 0;
1024 buf[1] = DHCPV6_OPT_STATUS;
1025 buf[2] = 0;
1026 buf[3] = 2;
1027 buf[4] = 0;
1028 buf[5] = DHCPV6_STATUS_OK;
1029 response_len += 6;
1030 }
1031
1032 if (update_state)
1033 dhcpv6_write_statefile();
1034
1035 out:
1036 return response_len;
1037 }
OpenWrt DHCP Server