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Use 1 socket per interface for DHCPv6
[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 uint32_t serial = 0;
36
37
38 int dhcpv6_ia_init(void)
39 {
40 uloop_timeout_set(&reconf_event, 2000);
41 return 0;
42 }
43
44
45 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
46 {
47 if (!enable && iface->ia_assignments.next) {
48 struct dhcpv6_assignment *c;
49 while (!list_empty(&iface->ia_assignments)) {
50 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
51 list_del(&c->head);
52 free(c->hostname);
53 free(c->classes);
54 free(c);
55 }
56 }
57
58 if (iface->dhcpv6 == RELAYD_SERVER) {
59 if (!iface->ia_assignments.next)
60 INIT_LIST_HEAD(&iface->ia_assignments);
61
62 if (list_empty(&iface->ia_assignments)) {
63 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
64 if (!border) {
65 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
66 return -1;
67 }
68
69 border->length = 64;
70 list_add(&border->head, &iface->ia_assignments);
71 }
72
73 update(iface);
74
75 // Parse static entries
76 struct lease *lease;
77 list_for_each_entry(lease, &leases, head) {
78 // Construct entry
79 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
80 if (!a) {
81 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
82 iface->ifname);
83 return -1;
84 }
85
86 a->clid_len = lease->duid_len;
87 a->length = 128;
88 if (lease->hostid) {
89 a->assigned = lease->hostid;
90 } else {
91 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
92 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
93 }
94 odhcpd_urandom(a->key, sizeof(a->key));
95 memcpy(a->clid_data, lease->duid, a->clid_len);
96 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
97
98 // Assign to all interfaces
99 struct dhcpv6_assignment *c;
100 list_for_each_entry(c, &iface->ia_assignments, head) {
101 if (c->length != 128 || c->assigned > a->assigned) {
102 list_add_tail(&a->head, &c->head);
103 } else if (c->assigned == a->assigned) {
104 // Already an assignment with that number
105 break;
106 }
107 }
108
109 if (a->head.next) {
110 if (lease->hostname[0]) {
111 free(a->hostname);
112 a->hostname = strdup(lease->hostname);
113 }
114 } else {
115 free(a->classes);
116 free(a->hostname);
117 free(a);
118 }
119 }
120 }
121 return 0;
122 }
123
124
125 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
126 {
127 struct {
128 struct dhcpv6_client_header hdr;
129 uint16_t srvid_type;
130 uint16_t srvid_len;
131 uint16_t duid_type;
132 uint16_t hardware_type;
133 uint8_t mac[6];
134 uint16_t msg_type;
135 uint16_t msg_len;
136 uint8_t msg_id;
137 struct dhcpv6_auth_reconfigure auth;
138 uint16_t clid_type;
139 uint16_t clid_len;
140 uint8_t clid_data[128];
141 } __attribute__((packed)) reconf_msg = {
142 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
143 .srvid_type = htons(DHCPV6_OPT_SERVERID),
144 .srvid_len = htons(10),
145 .duid_type = htons(3),
146 .hardware_type = htons(1),
147 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
148 .msg_len = htons(1),
149 .msg_id = DHCPV6_MSG_RENEW,
150 .auth = {htons(DHCPV6_OPT_AUTH),
151 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
152 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
153 .clid_type = htons(DHCPV6_OPT_CLIENTID),
154 .clid_len = htons(assign->clid_len),
155 .clid_data = {0},
156 };
157
158 odhcpd_get_mac(iface, reconf_msg.mac);
159 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
160 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
161
162 md5_ctx_t md5;
163 uint8_t secretbytes[16];
164 memcpy(secretbytes, assign->key, sizeof(secretbytes));
165
166 for (size_t i = 0; i < sizeof(secretbytes); ++i)
167 secretbytes[i] ^= 0x36;
168
169 md5_begin(&md5);
170 md5_hash(secretbytes, sizeof(secretbytes), &md5);
171 md5_hash(iov.iov_base, iov.iov_len, &md5);
172 md5_end(reconf_msg.auth.key, &md5);
173
174 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
175 secretbytes[i] ^= 0x36;
176 secretbytes[i] ^= 0x5c;
177 }
178
179 md5_begin(&md5);
180 md5_hash(secretbytes, sizeof(secretbytes), &md5);
181 md5_hash(reconf_msg.auth.key, 16, &md5);
182 md5_end(reconf_msg.auth.key, &md5);
183
184 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
185 }
186
187
188 void dhcpv6_write_statefile(void)
189 {
190 if (config.dhcp_statefile) {
191 time_t now = odhcpd_time(), wall_time = time(NULL);
192 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
193 if (fd < 0)
194 return;
195
196 lockf(fd, F_LOCK, 0);
197 ftruncate(fd, 0);
198
199 FILE *fp = fdopen(fd, "w");
200 if (!fp) {
201 close(fd);
202 return;
203 }
204
205 struct interface *iface;
206 list_for_each_entry(iface, &interfaces, head) {
207 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
208 continue;
209
210 if (iface->dhcpv6 == RELAYD_SERVER) {
211 struct dhcpv6_assignment *c;
212 list_for_each_entry(c, &iface->ia_assignments, head) {
213 if (c->clid_len == 0)
214 continue;
215
216 char ipbuf[INET6_ADDRSTRLEN];
217 char leasebuf[512];
218 char duidbuf[264];
219 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
220
221 // iface DUID iaid hostname lifetime assigned length [addrs...]
222 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
223 iface->ifname, duidbuf, ntohl(c->iaid),
224 (c->hostname ? c->hostname : "-"),
225 (unsigned)(c->valid_until > now ?
226 (c->valid_until - now + wall_time) : 0),
227 c->assigned, (unsigned)c->length);
228
229 struct in6_addr addr;
230 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
231 if (iface->ia_addr[i].prefix > 64)
232 continue;
233
234 addr = iface->ia_addr[i].addr;
235 if (c->length == 128)
236 addr.s6_addr32[3] = htonl(c->assigned);
237 else
238 addr.s6_addr32[1] |= htonl(c->assigned);
239 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
240
241 if (c->length == 128 && c->hostname && i == 0)
242 fprintf(fp, "%s\t%s\n", ipbuf, c->hostname);
243
244 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%hhu ", ipbuf, c->length);
245 }
246 leasebuf[l - 1] = '\n';
247 fwrite(leasebuf, 1, l, fp);
248 }
249 }
250
251 if (iface->dhcpv4 == RELAYD_SERVER) {
252 struct dhcpv4_assignment *c;
253 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
254 char ipbuf[INET6_ADDRSTRLEN];
255 char leasebuf[512];
256 char duidbuf[16];
257 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
258
259 // iface DUID iaid hostname lifetime assigned length [addrs...]
260 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
261 iface->ifname, duidbuf,
262 (c->hostname ? c->hostname : "-"),
263 (unsigned)(c->valid_until > now ?
264 (c->valid_until - now + wall_time) : 0),
265 c->addr);
266
267 struct in_addr addr = {htonl(c->addr)};
268 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
269
270 if (c->hostname[0])
271 fprintf(fp, "%s\t%s\n", ipbuf, c->hostname);
272
273 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
274 leasebuf[l - 1] = '\n';
275 fwrite(leasebuf, 1, l, fp);
276 }
277 }
278 }
279
280 fclose(fp);
281 }
282
283 if (config.dhcp_cb) {
284 char *argv[2] = {config.dhcp_cb, NULL};
285 if (!vfork()) {
286 execv(argv[0], argv);
287 _exit(128);
288 }
289 }
290 }
291
292
293 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
294 {
295 if (a->length > 64)
296 return;
297
298 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
299 struct in6_addr prefix = iface->ia_addr[i].addr;
300 prefix.s6_addr32[1] |= htonl(a->assigned);
301 odhcpd_setup_route(&prefix, a->length, iface, &a->peer.sin6_addr, add);
302 }
303 }
304
305
306 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
307 {
308 struct dhcpv6_assignment *c;
309 if (iface->ia_addr_len < 1)
310 return false;
311
312 // Try honoring the hint first
313 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
314 if (assign->assigned) {
315 list_for_each_entry(c, &iface->ia_assignments, head) {
316 if (c->length == 128)
317 continue;
318
319 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
320 list_add_tail(&assign->head, &c->head);
321 apply_lease(iface, assign, true);
322 return true;
323 }
324
325 if (c->assigned != 0)
326 current = (c->assigned + (1 << (64 - c->length)));
327 }
328 }
329
330 // Fallback to a variable assignment
331 current = 1;
332 list_for_each_entry(c, &iface->ia_assignments, head) {
333 if (c->length == 128)
334 continue;
335
336 current = (current + asize) & (~asize);
337 if (current + asize < c->assigned) {
338 assign->assigned = current;
339 list_add_tail(&assign->head, &c->head);
340 apply_lease(iface, assign, true);
341 return true;
342 }
343
344 if (c->assigned != 0)
345 current = (c->assigned + (1 << (64 - c->length)));
346 }
347
348 return false;
349 }
350
351
352 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
353 {
354 bool match = false;
355 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
356 if (!iface->ia_addr[i].has_class) {
357 match = true;
358 continue;
359 } else if (assign->classes_cnt) {
360 for (size_t j = 0; j < assign->classes_cnt; ++j)
361 if (assign->classes[j] == iface->ia_addr[i].class)
362 match = true;
363 } else if (assign->all_class) {
364 match = true;
365 }
366 }
367
368 if (!match)
369 return false;
370
371 // Seed RNG with checksum of DUID
372 uint32_t seed = 0;
373 for (size_t i = 0; i < assign->clid_len; ++i)
374 seed += assign->clid_data[i];
375 srand(seed);
376
377 // Try to assign up to 100x
378 for (size_t i = 0; i < 100; ++i) {
379 uint32_t try;
380 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
381
382 struct dhcpv6_assignment *c;
383 list_for_each_entry(c, &iface->ia_assignments, head) {
384 if (c->assigned > try || c->length != 128) {
385 assign->assigned = try;
386 list_add_tail(&assign->head, &c->head);
387 return true;
388 } else if (c->assigned == try) {
389 break;
390 }
391 }
392 }
393
394 return false;
395 }
396
397
398 static int prefixcmp(const void *va, const void *vb)
399 {
400 const struct odhcpd_ipaddr *a = va, *b = vb;
401 uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
402 uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
403 return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
404 }
405
406
407 static void update(struct interface *iface)
408 {
409 struct odhcpd_ipaddr addr[8];
410 memset(addr, 0, sizeof(addr));
411 int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
412
413 if (len < 0)
414 return;
415
416 qsort(addr, len, sizeof(*addr), prefixcmp);
417
418 time_t now = odhcpd_time();
419 int minprefix = -1;
420
421 for (int i = 0; i < len; ++i) {
422 if (addr[i].prefix > minprefix)
423 minprefix = addr[i].prefix;
424
425 addr[i].addr.s6_addr32[2] = 0;
426 addr[i].addr.s6_addr32[3] = 0;
427
428 if (addr[i].preferred < UINT32_MAX - now)
429 addr[i].preferred += now;
430
431 if (addr[i].valid < UINT32_MAX - now)
432 addr[i].valid += now;
433 }
434
435 struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
436 border->assigned = 1 << (64 - minprefix);
437
438 bool change = len != (int)iface->ia_addr_len;
439 for (int i = 0; !change && i < len; ++i)
440 if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
441 addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
442 (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
443 (addr[i].valid > (uint32_t)now + 7200) !=
444 (iface->ia_addr[i].valid > (uint32_t)now + 7200))
445 change = true;
446
447 if (change) {
448 struct dhcpv6_assignment *c;
449 list_for_each_entry(c, &iface->ia_assignments, head)
450 if (c != border)
451 apply_lease(iface, c, false);
452 }
453
454 memcpy(iface->ia_addr, addr, len * sizeof(*addr));
455 iface->ia_addr_len = len;
456
457 if (change) { // Addresses / prefixes have changed
458 struct list_head reassign = LIST_HEAD_INIT(reassign);
459 struct dhcpv6_assignment *c, *d;
460 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
461 if (c->clid_len == 0 || c->valid_until < now)
462 continue;
463
464 if (c->length < 128 && c->assigned >= border->assigned && c != border)
465 list_move(&c->head, &reassign);
466 else if (c != border)
467 apply_lease(iface, c, true);
468
469 if (c->accept_reconf && c->reconf_cnt == 0) {
470 c->reconf_cnt = 1;
471 c->reconf_sent = now;
472 send_reconf(iface, c);
473
474 // Leave all other assignments of that client alone
475 struct dhcpv6_assignment *a;
476 list_for_each_entry(a, &iface->ia_assignments, head)
477 if (a != c && a->clid_len == c->clid_len &&
478 !memcmp(a->clid_data, c->clid_data, a->clid_len))
479 c->reconf_cnt = INT_MAX;
480 }
481 }
482
483 while (!list_empty(&reassign)) {
484 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
485 list_del(&c->head);
486 if (!assign_pd(iface, c)) {
487 c->assigned = 0;
488 list_add(&c->head, &iface->ia_assignments);
489 }
490 }
491
492 dhcpv6_write_statefile();
493 }
494 }
495
496
497 static void reconf_timer(struct uloop_timeout *event)
498 {
499 time_t now = odhcpd_time();
500 struct interface *iface;
501 list_for_each_entry(iface, &interfaces, head) {
502 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
503 continue;
504
505 struct dhcpv6_assignment *a, *n;
506 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
507 if (a->valid_until < now) {
508 if ((a->length < 128 && a->clid_len > 0) ||
509 (a->length == 128 && a->clid_len == 0)) {
510 list_del(&a->head);
511 free(a->classes);
512 free(a->hostname);
513 free(a);
514 }
515 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
516 now > a->reconf_sent + (1 << a->reconf_cnt)) {
517 ++a->reconf_cnt;
518 a->reconf_sent = now;
519 send_reconf(iface, a);
520 }
521 }
522
523 if (iface->ia_reconf) {
524 update(iface);
525 iface->ia_reconf = false;
526 }
527 }
528
529 uloop_timeout_set(event, 2000);
530 }
531
532
533 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
534 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
535 struct interface *iface, bool request)
536 {
537 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
538 return 0;
539
540 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
541 size_t datalen = sizeof(out);
542 time_t now = odhcpd_time();
543
544 if (status) {
545 struct __attribute__((packed)) {
546 uint16_t type;
547 uint16_t len;
548 uint16_t value;
549 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
550 htons(status)};
551
552 memcpy(buf + datalen, &stat, sizeof(stat));
553 datalen += sizeof(stat);
554 } else {
555 if (a) {
556 uint32_t pref = 3600;
557 uint32_t valid = 3600;
558
559 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
560 bool match = true;
561 if (iface->ia_addr[i].has_class) {
562 match = false;
563 if (a->classes_cnt) {
564 for (size_t j = 0; j < a->classes_cnt; ++j)
565 if (a->classes[j] == iface->ia_addr[i].class)
566 match = true;
567 } else if (a->all_class) {
568 match = true;
569 }
570 }
571
572 if (!match)
573 continue;
574
575 uint32_t prefix_pref = iface->ia_addr[i].preferred - now;
576 uint32_t prefix_valid = iface->ia_addr[i].valid - now;
577
578 if (iface->ia_addr[i].prefix > 64 ||
579 iface->ia_addr[i].preferred <= (uint32_t)now)
580 continue;
581
582 if (prefix_pref > 86400)
583 prefix_pref = 86400;
584
585 if (prefix_valid > 86400)
586 prefix_valid = 86400;
587
588 #ifdef DHCPV6_OPT_PREFIX_CLASS
589 struct {
590 uint16_t code;
591 uint16_t length;
592 uint16_t class;
593 } pclass = {htons(DHCPV6_OPT_PREFIX_CLASS),
594 htons(2), htons(iface->ia_addr[i].class)};
595 #endif
596
597 if (a->length < 128) {
598 struct dhcpv6_ia_prefix p = {
599 .type = htons(DHCPV6_OPT_IA_PREFIX),
600 .len = htons(sizeof(p) - 4),
601 .preferred = htonl(prefix_pref),
602 .valid = htonl(prefix_valid),
603 .prefix = a->length,
604 .addr = iface->ia_addr[i].addr
605 };
606 p.addr.s6_addr32[1] |= htonl(a->assigned);
607 size_t entrlen = sizeof(p) - 4;
608
609 #ifdef DHCPV6_OPT_PREFIX_CLASS
610 if (iface->ia_addr[i].has_class) {
611 entrlen += sizeof(pclass);
612 p.len = htons(entrlen);
613 }
614 #endif
615
616 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
617 continue;
618
619 memcpy(buf + datalen, &p, sizeof(p));
620 #ifdef DHCPV6_OPT_PREFIX_CLASS
621 memcpy(buf + datalen + sizeof(p), &pclass, sizeof(pclass));
622 #endif
623 datalen += entrlen + 4;
624 } else {
625 struct dhcpv6_ia_addr n = {
626 .type = htons(DHCPV6_OPT_IA_ADDR),
627 .len = htons(sizeof(n) - 4),
628 .addr = iface->ia_addr[i].addr,
629 .preferred = htonl(prefix_pref),
630 .valid = htonl(prefix_valid)
631 };
632 n.addr.s6_addr32[3] = htonl(a->assigned);
633 size_t entrlen = sizeof(n) - 4;
634
635 #ifdef DHCPV6_OPT_PREFIX_CLASS
636 if (iface->ia_addr[i].has_class) {
637 entrlen += sizeof(pclass);
638 n.len = htons(entrlen);
639 }
640 #endif
641
642 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
643 continue;
644
645 memcpy(buf + datalen, &n, sizeof(n));
646 #ifdef DHCPV6_OPT_PREFIX_CLASS
647 memcpy(buf + datalen + sizeof(n), &pclass, sizeof(pclass));
648 #endif
649 datalen += entrlen + 4;
650 }
651
652 // Calculate T1 / T2 based on non-deprecated addresses
653 if (prefix_pref > 0) {
654 if (prefix_pref < pref)
655 pref = prefix_pref;
656
657 if (prefix_valid < valid)
658 valid = prefix_valid;
659 }
660 }
661
662 a->valid_until = valid + now;
663 out.t1 = htonl(pref * 5 / 10);
664 out.t2 = htonl(pref * 8 / 10);
665
666 if (!out.t1)
667 out.t1 = htonl(1);
668
669 if (!out.t2)
670 out.t2 = htonl(1);
671 }
672
673 if (!request) {
674 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
675 uint16_t otype, olen;
676 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
677 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
678 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
679 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
680 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
681 continue;
682
683 bool found = false;
684 if (a) {
685 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
686 if (iface->ia_addr[i].prefix > 64 ||
687 iface->ia_addr[i].preferred <= (uint32_t)now)
688 continue;
689
690 struct in6_addr addr = iface->ia_addr[i].addr;
691 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
692 addr.s6_addr32[1] |= htonl(a->assigned);
693
694 if (IN6_ARE_ADDR_EQUAL(&p->addr, &addr) &&
695 p->prefix == a->length)
696 found = true;
697 } else {
698 addr.s6_addr32[3] = htonl(a->assigned);
699
700 if (IN6_ARE_ADDR_EQUAL(&n->addr, &addr))
701 found = true;
702 }
703 }
704 }
705
706 if (!found) {
707 if (otype == DHCPV6_OPT_IA_PREFIX) {
708 struct dhcpv6_ia_prefix inv = {
709 .type = htons(DHCPV6_OPT_IA_PREFIX),
710 .len = htons(sizeof(inv) - 4),
711 .preferred = 0,
712 .valid = 0,
713 .prefix = p->prefix,
714 .addr = p->addr
715 };
716
717 if (datalen + sizeof(inv) > buflen)
718 continue;
719
720 memcpy(buf + datalen, &inv, sizeof(inv));
721 datalen += sizeof(inv);
722 } else {
723 struct dhcpv6_ia_addr inv = {
724 .type = htons(DHCPV6_OPT_IA_ADDR),
725 .len = htons(sizeof(inv) - 4),
726 .addr = n->addr,
727 .preferred = 0,
728 .valid = 0
729 };
730
731 if (datalen + sizeof(inv) > buflen)
732 continue;
733
734 memcpy(buf + datalen, &inv, sizeof(inv));
735 datalen += sizeof(inv);
736 }
737 }
738 }
739 }
740 }
741
742 out.len = htons(datalen - 4);
743 memcpy(buf, &out, sizeof(out));
744 return datalen;
745 }
746
747
748 size_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
749 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
750 {
751 time_t now = odhcpd_time();
752 size_t response_len = 0;
753 const struct dhcpv6_client_header *hdr = data;
754 uint8_t *start = (uint8_t*)&hdr[1], *odata;
755 uint16_t otype, olen;
756
757 // Find and parse client-id and hostname
758 bool accept_reconf = false;
759 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
760 char hostname[256];
761 size_t hostname_len = 0;
762 bool class_oro = false;
763 dhcpv6_for_each_option(start, end, otype, olen, odata) {
764 if (otype == DHCPV6_OPT_CLIENTID) {
765 clid_data = odata;
766 clid_len = olen;
767
768 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
769 memcpy(mac, &odata[8], sizeof(mac));
770 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
771 memcpy(mac, &odata[4], sizeof(mac));
772 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
773 uint8_t fqdn_buf[256];
774 memcpy(fqdn_buf, odata, olen);
775 fqdn_buf[olen++] = 0;
776
777 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
778 hostname_len = strcspn(hostname, ".");
779 } else if (otype == DHCPV6_OPT_ORO) {
780 #ifdef DHCPV6_OPT_PREFIX_CLASS
781 for (size_t i = 0; i + 1 < olen; i += 2) {
782 if (odata[i] == (DHCPV6_OPT_PREFIX_CLASS >> 8) &&
783 odata[i + 1] == (DHCPV6_OPT_PREFIX_CLASS & 0xff))
784 class_oro = true;
785 }
786 #endif
787 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
788 accept_reconf = true;
789 }
790 }
791
792 if (!clid_data || !clid_len || clid_len > 130)
793 goto out;
794
795 update(iface);
796 bool update_state = false;
797
798 struct dhcpv6_assignment *first = NULL;
799 dhcpv6_for_each_option(start, end, otype, olen, odata) {
800 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
801 bool is_na = (otype == DHCPV6_OPT_IA_NA);
802 if (!is_pd && !is_na)
803 continue;
804
805 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
806 size_t ia_response_len = 0;
807 uint8_t reqlen = (is_pd) ? 62 : 128;
808 uint32_t reqhint = 0;
809
810 const uint8_t classes_max = 32;
811 uint8_t classes_cnt = 0;
812 uint16_t classes[classes_max];
813
814 // Parse request hint for IA-PD
815 if (is_pd) {
816 uint8_t *sdata;
817 uint16_t stype, slen;
818 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
819 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
820 continue;
821
822 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
823 if (p->prefix) {
824 reqlen = p->prefix;
825 reqhint = ntohl(p->addr.s6_addr32[1]);
826 if (reqlen > 32 && reqlen <= 64)
827 reqhint &= (1U << (64 - reqlen)) - 1;
828 }
829
830 #ifdef DHCPV6_OPT_PREFIX_CLASS
831 uint8_t *xdata;
832 uint16_t xtype, xlen;
833 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
834 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
835 continue;
836
837 if (classes_cnt >= classes_max)
838 continue;
839
840 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
841 }
842 #endif
843 }
844
845 if (reqlen > 64)
846 reqlen = 64;
847 } else if (is_na) {
848 uint8_t *sdata;
849 uint16_t stype, slen;
850 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
851 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
852 continue;
853
854 #ifdef DHCPV6_OPT_PREFIX_CLASS
855 uint8_t *xdata;
856 uint16_t xtype, xlen;
857 struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
858 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
859 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
860 continue;
861
862 if (classes_cnt >= classes_max)
863 continue;
864
865 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
866 }
867 #endif
868 }
869 }
870
871 // Find assignment
872 struct dhcpv6_assignment *c, *a = NULL;
873 list_for_each_entry(c, &iface->ia_assignments, head) {
874 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
875 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
876 && !memcmp(c->mac, mac, sizeof(mac)))) &&
877 (c->iaid == ia->iaid || c->valid_until < now) &&
878 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
879 a = c;
880
881 // Reset state
882 apply_lease(iface, a, false);
883 memcpy(a->clid_data, clid_data, clid_len);
884 a->clid_len = clid_len;
885 a->iaid = ia->iaid;
886 a->peer = *addr;
887 a->reconf_cnt = 0;
888 a->reconf_sent = 0;
889 a->all_class = class_oro;
890 a->classes_cnt = classes_cnt;
891 a->classes = realloc(a->classes, classes_cnt * sizeof(uint16_t));
892 if (a->classes)
893 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
894 break;
895 }
896 }
897
898 // Generic message handling
899 uint16_t status = DHCPV6_STATUS_OK;
900 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
901 bool assigned = !!a;
902
903 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
904 a = calloc(1, sizeof(*a) + clid_len);
905 if (a) {
906 a->clid_len = clid_len;
907 a->iaid = ia->iaid;
908 a->length = reqlen;
909 a->peer = *addr;
910 a->assigned = reqhint;
911 a->all_class = class_oro;
912 a->classes_cnt = classes_cnt;
913 if (classes_cnt) {
914 a->classes = malloc(classes_cnt * sizeof(uint16_t));
915 if (a->classes)
916 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
917 }
918
919 if (first)
920 memcpy(a->key, first->key, sizeof(a->key));
921 else
922 odhcpd_urandom(a->key, sizeof(a->key));
923 memcpy(a->clid_data, clid_data, clid_len);
924
925 if (is_pd)
926 while (!(assigned = assign_pd(iface, a)) && ++a->length <= 64);
927 else
928 assigned = assign_na(iface, a);
929 }
930 }
931
932 if (!assigned || iface->ia_addr_len == 0) { // Set error status
933 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
934 } else if (assigned && !first) { //
935 size_t handshake_len = 4;
936 buf[0] = 0;
937 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
938 buf[2] = 0;
939 buf[3] = 0;
940
941 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
942 struct dhcpv6_auth_reconfigure auth = {
943 htons(DHCPV6_OPT_AUTH),
944 htons(sizeof(auth) - 4),
945 3, 1, 0,
946 {htonl(time(NULL)), htonl(++serial)},
947 1,
948 {0}
949 };
950 memcpy(auth.key, a->key, sizeof(a->key));
951 memcpy(buf + handshake_len, &auth, sizeof(auth));
952 handshake_len += sizeof(auth);
953 }
954
955 buf += handshake_len;
956 buflen -= handshake_len;
957 response_len += handshake_len;
958
959 first = a;
960 }
961
962 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
963
964 // Was only a solicitation: mark binding for removal
965 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
966 a->valid_until = 0;
967 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
968 if (hostname_len > 0) {
969 a->hostname = realloc(a->hostname, hostname_len + 1);
970 if (a->hostname) {
971 memcpy(a->hostname, hostname, hostname_len);
972 a->hostname[hostname_len] = 0;
973 }
974 }
975 a->accept_reconf = accept_reconf;
976 apply_lease(iface, a, true);
977 update_state = true;
978 } else if (!assigned && a) { // Cleanup failed assignment
979 free(a->classes);
980 free(a->hostname);
981 free(a);
982 }
983 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
984 hdr->msg_type == DHCPV6_MSG_RELEASE ||
985 hdr->msg_type == DHCPV6_MSG_REBIND ||
986 hdr->msg_type == DHCPV6_MSG_DECLINE) {
987 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
988 status = DHCPV6_STATUS_NOBINDING;
989 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
990 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
991 hdr->msg_type == DHCPV6_MSG_REBIND) {
992 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
993 if (a)
994 apply_lease(iface, a, true);
995 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
996 a->valid_until = 0;
997 apply_lease(iface, a, false);
998 update_state = true;
999 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1000 a->clid_len = 0;
1001 a->valid_until = now + 3600; // Block address for 1h
1002 update_state = true;
1003 }
1004 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1005 // Always send NOTONLINK for CONFIRM so that clients restart connection
1006 status = DHCPV6_STATUS_NOTONLINK;
1007 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1008 }
1009
1010 buf += ia_response_len;
1011 buflen -= ia_response_len;
1012 response_len += ia_response_len;
1013 }
1014
1015 if (hdr->msg_type == DHCPV6_MSG_RELEASE && response_len + 6 < buflen) {
1016 buf[0] = 0;
1017 buf[1] = DHCPV6_OPT_STATUS;
1018 buf[2] = 0;
1019 buf[3] = 2;
1020 buf[4] = 0;
1021 buf[5] = DHCPV6_STATUS_OK;
1022 response_len += 6;
1023 }
1024
1025 if (update_state)
1026 dhcpv6_write_statefile();
1027
1028 out:
1029 return response_len;
1030 }
OpenWrt DHCP Server