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use leaetime as base for T1 and T2 upper bound
[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 #include "libubox/usock.h"
20
21 #include <time.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <poll.h>
26 #include <alloca.h>
27 #include <resolv.h>
28 #include <limits.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 #include <stdbool.h>
33 #include <arpa/inet.h>
34 #include <sys/timerfd.h>
35
36
37 static void update(struct interface *iface);
38 static void reconf_timer(struct uloop_timeout *event);
39 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
40 static uint32_t serial = 0;
41 static uint8_t statemd5[16];
42
43
44 int dhcpv6_ia_init(void)
45 {
46 uloop_timeout_set(&reconf_event, 2000);
47 return 0;
48 }
49
50
51 void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
52 {
53 if (c->managed_sock.fd.registered) {
54 ustream_free(&c->managed_sock.stream);
55 close(c->managed_sock.fd.fd);
56 }
57
58 if (c->head.next)
59 list_del(&c->head);
60
61 free(c->managed);
62 free(c->hostname);
63 free(c->classes);
64 free(c);
65 }
66
67
68 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
69 {
70 if (!enable && iface->ia_assignments.next) {
71 struct dhcpv6_assignment *c;
72 while (!list_empty(&iface->ia_assignments)) {
73 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
74 free_dhcpv6_assignment(c);
75 }
76 }
77
78 if (iface->dhcpv6 == RELAYD_SERVER) {
79 if (!iface->ia_assignments.next)
80 INIT_LIST_HEAD(&iface->ia_assignments);
81
82 if (list_empty(&iface->ia_assignments)) {
83 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
84 if (!border) {
85 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
86 return -1;
87 }
88
89 border->length = 64;
90 list_add(&border->head, &iface->ia_assignments);
91 }
92
93 update(iface);
94
95 // Parse static entries
96 struct lease *lease;
97 list_for_each_entry(lease, &leases, head) {
98 // Construct entry
99 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
100 if (!a) {
101 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
102 iface->ifname);
103 return -1;
104 }
105
106 a->clid_len = lease->duid_len;
107 a->length = 128;
108 if (lease->hostid) {
109 a->assigned = lease->hostid;
110 } else {
111 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
112 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
113 }
114 odhcpd_urandom(a->key, sizeof(a->key));
115 memcpy(a->clid_data, lease->duid, a->clid_len);
116 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
117
118 // Assign to all interfaces
119 struct dhcpv6_assignment *c;
120 list_for_each_entry(c, &iface->ia_assignments, head) {
121 if (c->length != 128 || c->assigned > a->assigned) {
122 list_add_tail(&a->head, &c->head);
123 break;
124 } else if (c->assigned == a->assigned) {
125 // Already an assignment with that number
126 break;
127 }
128 }
129
130 if (a->head.next) {
131 if (lease->hostname[0]) {
132 free(a->hostname);
133 a->hostname = strdup(lease->hostname);
134 }
135 } else {
136 free(a->classes);
137 free(a->hostname);
138 free(a);
139 }
140 }
141 }
142 return 0;
143 }
144
145
146 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
147 {
148 struct {
149 struct dhcpv6_client_header hdr;
150 uint16_t srvid_type;
151 uint16_t srvid_len;
152 uint16_t duid_type;
153 uint16_t hardware_type;
154 uint8_t mac[6];
155 uint16_t msg_type;
156 uint16_t msg_len;
157 uint8_t msg_id;
158 struct dhcpv6_auth_reconfigure auth;
159 uint16_t clid_type;
160 uint16_t clid_len;
161 uint8_t clid_data[128];
162 } __attribute__((packed)) reconf_msg = {
163 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
164 .srvid_type = htons(DHCPV6_OPT_SERVERID),
165 .srvid_len = htons(10),
166 .duid_type = htons(3),
167 .hardware_type = htons(1),
168 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
169 .msg_len = htons(1),
170 .msg_id = DHCPV6_MSG_RENEW,
171 .auth = {htons(DHCPV6_OPT_AUTH),
172 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
173 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
174 .clid_type = htons(DHCPV6_OPT_CLIENTID),
175 .clid_len = htons(assign->clid_len),
176 .clid_data = {0},
177 };
178
179 odhcpd_get_mac(iface, reconf_msg.mac);
180 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
181 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
182
183 md5_ctx_t md5;
184 uint8_t secretbytes[64];
185 memset(secretbytes, 0, sizeof(secretbytes));
186 memcpy(secretbytes, assign->key, sizeof(assign->key));
187
188 for (size_t i = 0; i < sizeof(secretbytes); ++i)
189 secretbytes[i] ^= 0x36;
190
191 md5_begin(&md5);
192 md5_hash(secretbytes, sizeof(secretbytes), &md5);
193 md5_hash(iov.iov_base, iov.iov_len, &md5);
194 md5_end(reconf_msg.auth.key, &md5);
195
196 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
197 secretbytes[i] ^= 0x36;
198 secretbytes[i] ^= 0x5c;
199 }
200
201 md5_begin(&md5);
202 md5_hash(secretbytes, sizeof(secretbytes), &md5);
203 md5_hash(reconf_msg.auth.key, 16, &md5);
204 md5_end(reconf_msg.auth.key, &md5);
205
206 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
207 }
208
209
210 void dhcpv6_write_statefile(void)
211 {
212 md5_ctx_t md5;
213 md5_begin(&md5);
214
215 if (config.dhcp_statefile) {
216 time_t now = odhcpd_time(), wall_time = time(NULL);
217 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
218 if (fd < 0)
219 return;
220
221 lockf(fd, F_LOCK, 0);
222 ftruncate(fd, 0);
223
224 FILE *fp = fdopen(fd, "w");
225 if (!fp) {
226 close(fd);
227 return;
228 }
229
230 struct interface *iface;
231 list_for_each_entry(iface, &interfaces, head) {
232 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
233 continue;
234
235 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
236 struct dhcpv6_assignment *c;
237 list_for_each_entry(c, &iface->ia_assignments, head) {
238 if (c->clid_len == 0 || c->managed_size < 0)
239 continue;
240
241 char ipbuf[INET6_ADDRSTRLEN];
242 char leasebuf[512];
243 char duidbuf[264];
244 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
245
246 // iface DUID iaid hostname lifetime assigned length [addrs...]
247 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
248 iface->ifname, duidbuf, ntohl(c->iaid),
249 (c->hostname ? c->hostname : "-"),
250 (unsigned)(c->valid_until > now ?
251 (c->valid_until - now + wall_time) : 0),
252 c->assigned, (unsigned)c->length);
253
254 struct in6_addr addr;
255 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
256 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
257
258 for (size_t i = 0; i < addrlen; ++i) {
259 if (addrs[i].prefix > 96)
260 continue;
261
262 addr = addrs[i].addr;
263 if (c->length == 128)
264 addr.s6_addr32[3] = htonl(c->assigned);
265 else
266 addr.s6_addr32[1] |= htonl(c->assigned);
267
268 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
269
270 if (c->length == 128 && c->hostname && i == 0) {
271 fputs(ipbuf, fp);
272
273 char b[256];
274 if (dn_expand(iface->search, iface->search + iface->search_len,
275 iface->search, b, sizeof(b)) > 0)
276 fprintf(fp, "\t%s.%s", c->hostname, b);
277
278 fprintf(fp, "\t%s\n", c->hostname);
279 md5_hash(ipbuf, strlen(ipbuf), &md5);
280 md5_hash(c->hostname, strlen(c->hostname), &md5);
281 }
282
283 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
284 (c->managed_size) ? addrs[i].prefix : c->length);
285 }
286 leasebuf[l - 1] = '\n';
287 fwrite(leasebuf, 1, l, fp);
288 }
289 }
290
291 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
292 struct dhcpv4_assignment *c;
293 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
294 char ipbuf[INET6_ADDRSTRLEN];
295 char leasebuf[512];
296 char duidbuf[16];
297 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
298
299 // iface DUID iaid hostname lifetime assigned length [addrs...]
300 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
301 iface->ifname, duidbuf,
302 (c->hostname ? c->hostname : "-"),
303 (unsigned)(c->valid_until > now ?
304 (c->valid_until - now + wall_time) : 0),
305 c->addr);
306
307 struct in_addr addr = {htonl(c->addr)};
308 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
309
310 if (c->hostname[0]) {
311 fputs(ipbuf, fp);
312
313 char b[256];
314 if (dn_expand(iface->search, iface->search + iface->search_len,
315 iface->search, b, sizeof(b)) > 0)
316 fprintf(fp, "\t%s.%s", c->hostname, b);
317
318 fprintf(fp, "\t%s\n", c->hostname);
319 md5_hash(ipbuf, strlen(ipbuf), &md5);
320 md5_hash(c->hostname, strlen(c->hostname), &md5);
321 }
322
323 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
324 leasebuf[l - 1] = '\n';
325 fwrite(leasebuf, 1, l, fp);
326 }
327 }
328 }
329
330 fclose(fp);
331 }
332
333 uint8_t newmd5[16];
334 md5_end(newmd5, &md5);
335
336 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
337 memcpy(statemd5, newmd5, sizeof(statemd5));
338 char *argv[2] = {config.dhcp_cb, NULL};
339 if (!vfork()) {
340 execv(argv[0], argv);
341 _exit(128);
342 }
343 }
344 }
345
346
347 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
348 {
349 if (a->length > 64 || a->managed_size < 0)
350 return;
351
352 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
353 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
354
355 for (size_t i = 0; i < addrlen; ++i) {
356 struct in6_addr prefix = addrs[i].addr;
357 prefix.s6_addr32[1] |= htonl(a->assigned);
358 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
359 iface, &a->peer.sin6_addr, add);
360 }
361 }
362
363
364 // More data was received from TCP connection
365 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
366 {
367 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
368 time_t now = odhcpd_time();
369 bool first = c->managed_size < 0;
370
371 for (;;) {
372 int pending;
373 char *data = ustream_get_read_buf(s, &pending);
374 char *end = memmem(data, pending, "\n\n", 2);
375
376 if (!end)
377 break;
378
379 end += 2;
380 end[-1] = 0;
381
382 c->managed_size = 0;
383 if (c->accept_reconf)
384 c->reconf_cnt = 1;
385
386 char *saveptr;
387 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
388 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
389 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
390
391 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
392 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
393 continue;
394
395 x = strtok_r(NULL, ",", &saveptr2);
396 if (sscanf(x, "%hhu", &n->prefix) < 1)
397 continue;
398
399 x = strtok_r(NULL, ",", &saveptr2);
400 if (sscanf(x, "%u", &n->preferred) < 1)
401 continue;
402
403 x = strtok_r(NULL, ",", &saveptr2);
404 if (sscanf(x, "%u", &n->valid) < 1)
405 continue;
406
407 if (n->preferred > n->valid)
408 continue;
409
410 if (UINT32_MAX - now < n->preferred)
411 n->preferred = UINT32_MAX;
412 else
413 n->preferred += now;
414
415 if (UINT32_MAX - now < n->valid)
416 n->valid = UINT32_MAX;
417 else
418 n->valid += now;
419
420 n->has_class = false;
421 n->class = 0;
422 n->dprefix = 0;
423
424 ++c->managed_size;
425 }
426
427 ustream_consume(s, end - data);
428 }
429
430 if (first && c->managed_size == 0)
431 free_dhcpv6_assignment(c);
432 else if (first)
433 c->valid_until = now + 150;
434 }
435
436
437 // TCP transmission has ended, either because of success or timeout or other error
438 static void managed_handle_pd_done(struct ustream *s)
439 {
440 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
441 c->valid_until = odhcpd_time() + 15;
442 c->managed_size = 0;
443 if (c->accept_reconf)
444 c->reconf_cnt = 1;
445 }
446
447
448
449 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
450 {
451 struct dhcpv6_assignment *c;
452
453 if (iface->dhcpv6_pd_manager[0]) {
454 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
455 if (fd >= 0) {
456 char iaidbuf[298];
457 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
458
459 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
460 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
461 ustream_fd_init(&assign->managed_sock, fd);
462 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
463 iaidbuf, assign->iaid, assign->length);
464 ustream_write_pending(&assign->managed_sock.stream);
465 assign->managed_size = -1;
466 assign->valid_until = odhcpd_time() + 15;
467 list_add(&assign->head, &iface->ia_assignments);
468
469 // Wait initial period of up to 250ms for immediate assignment
470 struct pollfd pfd = { .fd = fd, .events = POLLIN };
471 poll(&pfd, 1, 250);
472 managed_handle_pd_data(&assign->managed_sock.stream, 0);
473
474 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
475 return true;
476 }
477
478 return false;
479 } else if (iface->ia_addr_len < 1) {
480 return false;
481 }
482
483 // Try honoring the hint first
484 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
485 if (assign->assigned) {
486 list_for_each_entry(c, &iface->ia_assignments, head) {
487 if (c->length == 128 || c->length == 0)
488 continue;
489
490 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
491 list_add_tail(&assign->head, &c->head);
492 apply_lease(iface, assign, true);
493 return true;
494 }
495
496 if (c->assigned != 0)
497 current = (c->assigned + (1 << (64 - c->length)));
498 }
499 }
500
501 // Fallback to a variable assignment
502 current = 1;
503 list_for_each_entry(c, &iface->ia_assignments, head) {
504 if (c->length == 128 || c->length == 0)
505 continue;
506
507 current = (current + asize) & (~asize);
508 if (current + asize < c->assigned) {
509 assign->assigned = current;
510 list_add_tail(&assign->head, &c->head);
511 apply_lease(iface, assign, true);
512 return true;
513 }
514
515 if (c->assigned != 0)
516 current = (c->assigned + (1 << (64 - c->length)));
517 }
518
519 return false;
520 }
521
522
523 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
524 {
525 bool match = false;
526 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
527 if (!iface->ia_addr[i].has_class) {
528 match = true;
529 continue;
530 } else if (assign->classes_cnt) {
531 for (size_t j = 0; j < assign->classes_cnt; ++j)
532 if (assign->classes[j] == iface->ia_addr[i].class)
533 match = true;
534 } else if (assign->all_class) {
535 match = true;
536 }
537 }
538
539 if (!match)
540 return false;
541
542 // Seed RNG with checksum of DUID
543 uint32_t seed = 0;
544 for (size_t i = 0; i < assign->clid_len; ++i)
545 seed += assign->clid_data[i];
546 srand(seed);
547
548 // Try to assign up to 100x
549 for (size_t i = 0; i < 100; ++i) {
550 uint32_t try;
551 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
552
553 struct dhcpv6_assignment *c;
554 list_for_each_entry(c, &iface->ia_assignments, head) {
555 if (c->length == 0)
556 continue;
557
558 if (c->assigned > try || c->length != 128) {
559 assign->assigned = try;
560 list_add_tail(&assign->head, &c->head);
561 return true;
562 } else if (c->assigned == try) {
563 break;
564 }
565 }
566 }
567
568 return false;
569 }
570
571
572 static int prefixcmp(const void *va, const void *vb)
573 {
574 const struct odhcpd_ipaddr *a = va, *b = vb;
575 uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
576 uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
577 return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
578 }
579
580
581 static void update(struct interface *iface)
582 {
583 struct odhcpd_ipaddr addr[8];
584 memset(addr, 0, sizeof(addr));
585 int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
586
587 if (len < 0)
588 return;
589
590 qsort(addr, len, sizeof(*addr), prefixcmp);
591
592 time_t now = odhcpd_time();
593 int minprefix = -1;
594
595 for (int i = 0; i < len; ++i) {
596 if (addr[i].prefix > minprefix)
597 minprefix = addr[i].prefix;
598
599 addr[i].addr.s6_addr32[3] = 0;
600
601 if (addr[i].preferred < UINT32_MAX - now)
602 addr[i].preferred += now;
603
604 if (addr[i].valid < UINT32_MAX - now)
605 addr[i].valid += now;
606 }
607
608 struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
609 border->assigned = 1 << (64 - minprefix);
610
611 bool change = len != (int)iface->ia_addr_len;
612 for (int i = 0; !change && i < len; ++i)
613 if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
614 addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
615 (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
616 (addr[i].valid > (uint32_t)now + 7200) !=
617 (iface->ia_addr[i].valid > (uint32_t)now + 7200))
618 change = true;
619
620 if (change) {
621 struct dhcpv6_assignment *c;
622 list_for_each_entry(c, &iface->ia_assignments, head)
623 if (c != border)
624 apply_lease(iface, c, false);
625 }
626
627 memcpy(iface->ia_addr, addr, len * sizeof(*addr));
628 iface->ia_addr_len = len;
629
630 if (change) { // Addresses / prefixes have changed
631 struct list_head reassign = LIST_HEAD_INIT(reassign);
632 struct dhcpv6_assignment *c, *d;
633 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
634 if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
635 continue;
636
637 if (c->length < 128 && c->assigned >= border->assigned && c != border)
638 list_move(&c->head, &reassign);
639 else if (c != border)
640 apply_lease(iface, c, true);
641
642 if (c->accept_reconf && c->reconf_cnt == 0) {
643 c->reconf_cnt = 1;
644 c->reconf_sent = now;
645 send_reconf(iface, c);
646
647 // Leave all other assignments of that client alone
648 struct dhcpv6_assignment *a;
649 list_for_each_entry(a, &iface->ia_assignments, head)
650 if (a != c && a->clid_len == c->clid_len &&
651 !memcmp(a->clid_data, c->clid_data, a->clid_len))
652 c->reconf_cnt = INT_MAX;
653 }
654 }
655
656 while (!list_empty(&reassign)) {
657 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
658 list_del(&c->head);
659 if (!assign_pd(iface, c)) {
660 c->assigned = 0;
661 list_add(&c->head, &iface->ia_assignments);
662 }
663 }
664
665 dhcpv6_write_statefile();
666 }
667 }
668
669
670 static void reconf_timer(struct uloop_timeout *event)
671 {
672 time_t now = odhcpd_time();
673 struct interface *iface;
674 list_for_each_entry(iface, &interfaces, head) {
675 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
676 continue;
677
678 struct dhcpv6_assignment *a, *n;
679 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
680 if (a->valid_until < now) {
681 if ((a->length < 128 && a->clid_len > 0) ||
682 (a->length == 128 && a->clid_len == 0)) {
683 list_del(&a->head);
684 free_dhcpv6_assignment(a);
685 }
686 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
687 now > a->reconf_sent + (1 << a->reconf_cnt)) {
688 ++a->reconf_cnt;
689 a->reconf_sent = now;
690 send_reconf(iface, a);
691 }
692 }
693 }
694 uloop_timeout_set(event, 2000);
695 }
696
697
698 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
699 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
700 struct interface *iface, bool request)
701 {
702 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
703 return 0;
704
705 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
706 size_t datalen = sizeof(out);
707 time_t now = odhcpd_time();
708
709 if (status) {
710 struct __attribute__((packed)) {
711 uint16_t type;
712 uint16_t len;
713 uint16_t value;
714 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
715 htons(status)};
716
717 memcpy(buf + datalen, &stat, sizeof(stat));
718 datalen += sizeof(stat);
719 } else {
720 if (a) {
721 uint32_t leasetime = iface->dhcpv4_leasetime;
722 if (leasetime == 0)
723 leasetime = 3600;
724 else if (leasetime < 60)
725 leasetime = 60;
726
727 uint32_t pref = leasetime;
728 uint32_t valid = leasetime;
729
730 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
731 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
732
733 for (size_t i = 0; i < addrlen; ++i) {
734 bool match = true;
735 if (addrs[i].has_class) {
736 match = false;
737 if (a->classes_cnt) {
738 for (size_t j = 0; j < a->classes_cnt; ++j)
739 if (a->classes[j] == addrs[i].class)
740 match = true;
741 } else if (a->all_class) {
742 match = true;
743 }
744 }
745
746 if (!match)
747 continue;
748
749 uint32_t prefix_pref = addrs[i].preferred - now;
750 uint32_t prefix_valid = addrs[i].valid - now;
751
752 if (addrs[i].prefix > 96 ||
753 addrs[i].preferred <= (uint32_t)now)
754 continue;
755
756 if (prefix_pref > 86400)
757 prefix_pref = 86400;
758
759 if (prefix_valid > 86400)
760 prefix_valid = 86400;
761
762 #ifdef DHCPV6_OPT_PREFIX_CLASS
763 struct {
764 uint16_t code;
765 uint16_t length;
766 uint16_t class;
767 } pclass = {htons(DHCPV6_OPT_PREFIX_CLASS),
768 htons(2), htons(iface->ia_addr[i].class)};
769 #endif
770
771 if (a->length < 128) {
772 struct dhcpv6_ia_prefix p = {
773 .type = htons(DHCPV6_OPT_IA_PREFIX),
774 .len = htons(sizeof(p) - 4),
775 .preferred = htonl(prefix_pref),
776 .valid = htonl(prefix_valid),
777 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
778 .addr = addrs[i].addr
779 };
780 p.addr.s6_addr32[1] |= htonl(a->assigned);
781
782 size_t entrlen = sizeof(p) - 4;
783
784 #ifdef DHCPV6_OPT_PREFIX_CLASS
785 if (iface->ia_addr[i].has_class) {
786 entrlen += sizeof(pclass);
787 p.len = htons(entrlen);
788 }
789 #endif
790
791 if (datalen + entrlen + 4 > buflen ||
792 (a->assigned == 0 && a->managed_size == 0))
793 continue;
794
795 memcpy(buf + datalen, &p, sizeof(p));
796 #ifdef DHCPV6_OPT_PREFIX_CLASS
797 memcpy(buf + datalen + sizeof(p), &pclass, sizeof(pclass));
798 #endif
799 datalen += entrlen + 4;
800 } else {
801 struct dhcpv6_ia_addr n = {
802 .type = htons(DHCPV6_OPT_IA_ADDR),
803 .len = htons(sizeof(n) - 4),
804 .addr = addrs[i].addr,
805 .preferred = htonl(prefix_pref),
806 .valid = htonl(prefix_valid)
807 };
808 n.addr.s6_addr32[3] = htonl(a->assigned);
809 size_t entrlen = sizeof(n) - 4;
810
811 #ifdef DHCPV6_OPT_PREFIX_CLASS
812 if (iface->ia_addr[i].has_class) {
813 entrlen += sizeof(pclass);
814 n.len = htons(entrlen);
815 }
816 #endif
817
818 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
819 continue;
820
821 memcpy(buf + datalen, &n, sizeof(n));
822 #ifdef DHCPV6_OPT_PREFIX_CLASS
823 memcpy(buf + datalen + sizeof(n), &pclass, sizeof(pclass));
824 #endif
825 datalen += entrlen + 4;
826 }
827
828 // Calculate T1 / T2 based on non-deprecated addresses
829 if (prefix_pref > 0) {
830 if (prefix_pref < pref)
831 pref = prefix_pref;
832
833 if (prefix_valid < valid)
834 valid = prefix_valid;
835 }
836 }
837
838 a->valid_until = valid + now;
839 out.t1 = htonl(pref * 5 / 10);
840 out.t2 = htonl(pref * 8 / 10);
841
842 if (!out.t1)
843 out.t1 = htonl(1);
844
845 if (!out.t2)
846 out.t2 = htonl(1);
847 }
848
849 if (!request) {
850 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
851 uint16_t otype, olen;
852 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
853 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
854 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
855 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
856 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
857 continue;
858
859 bool found = false;
860 if (a) {
861 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
862 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
863
864 for (size_t i = 0; i < addrlen; ++i) {
865 if (addrs[i].prefix > 96 ||
866 addrs[i].preferred <= (uint32_t)now)
867 continue;
868
869 struct in6_addr addr = addrs[i].addr;
870 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
871 addr.s6_addr32[1] |= htonl(a->assigned);
872
873 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
874 p->prefix == a->length)
875 found = true;
876 } else {
877 addr.s6_addr32[3] = htonl(a->assigned);
878
879 if (!memcmp(&n->addr, &addr, sizeof(addr)))
880 found = true;
881 }
882 }
883 }
884
885 if (!found) {
886 if (otype == DHCPV6_OPT_IA_PREFIX) {
887 struct dhcpv6_ia_prefix inv = {
888 .type = htons(DHCPV6_OPT_IA_PREFIX),
889 .len = htons(sizeof(inv) - 4),
890 .preferred = 0,
891 .valid = 0,
892 .prefix = p->prefix,
893 .addr = p->addr
894 };
895
896 if (datalen + sizeof(inv) > buflen)
897 continue;
898
899 memcpy(buf + datalen, &inv, sizeof(inv));
900 datalen += sizeof(inv);
901 } else {
902 struct dhcpv6_ia_addr inv = {
903 .type = htons(DHCPV6_OPT_IA_ADDR),
904 .len = htons(sizeof(inv) - 4),
905 .addr = n->addr,
906 .preferred = 0,
907 .valid = 0
908 };
909
910 if (datalen + sizeof(inv) > buflen)
911 continue;
912
913 memcpy(buf + datalen, &inv, sizeof(inv));
914 datalen += sizeof(inv);
915 }
916 }
917 }
918 }
919 }
920
921 out.len = htons(datalen - 4);
922 memcpy(buf, &out, sizeof(out));
923 return datalen;
924 }
925
926
927 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
928 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
929 {
930 time_t now = odhcpd_time();
931 size_t response_len = 0;
932 const struct dhcpv6_client_header *hdr = data;
933 uint8_t *start = (uint8_t*)&hdr[1], *odata;
934 uint16_t otype, olen;
935
936 // Find and parse client-id and hostname
937 bool accept_reconf = false;
938 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
939 char hostname[256];
940 size_t hostname_len = 0;
941 bool class_oro = false;
942 bool notonlink = false;
943
944 dhcpv6_for_each_option(start, end, otype, olen, odata) {
945 if (otype == DHCPV6_OPT_CLIENTID) {
946 clid_data = odata;
947 clid_len = olen;
948
949 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
950 memcpy(mac, &odata[8], sizeof(mac));
951 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
952 memcpy(mac, &odata[4], sizeof(mac));
953 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
954 uint8_t fqdn_buf[256];
955 memcpy(fqdn_buf, odata, olen);
956 fqdn_buf[olen++] = 0;
957
958 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
959 hostname_len = strcspn(hostname, ".");
960 } else if (otype == DHCPV6_OPT_ORO) {
961 #ifdef DHCPV6_OPT_PREFIX_CLASS
962 for (size_t i = 0; i + 1 < olen; i += 2) {
963 if (odata[i] == (DHCPV6_OPT_PREFIX_CLASS >> 8) &&
964 odata[i + 1] == (DHCPV6_OPT_PREFIX_CLASS & 0xff))
965 class_oro = true;
966 }
967 #endif
968 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
969 accept_reconf = true;
970 }
971 }
972
973 if (!clid_data || !clid_len || clid_len > 130)
974 goto out;
975
976 update(iface);
977 bool update_state = false;
978
979 struct dhcpv6_assignment *first = NULL;
980 dhcpv6_for_each_option(start, end, otype, olen, odata) {
981 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
982 bool is_na = (otype == DHCPV6_OPT_IA_NA);
983 bool ia_addr_present = false;
984 if (!is_pd && !is_na)
985 continue;
986
987 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
988 size_t ia_response_len = 0;
989 uint8_t reqlen = (is_pd) ? 62 : 128;
990 uint32_t reqhint = 0;
991
992 const uint8_t classes_max = 32;
993 uint8_t classes_cnt = 0;
994 uint16_t classes[classes_max];
995
996 // Parse request hint for IA-PD
997 if (is_pd) {
998 uint8_t *sdata;
999 uint16_t stype, slen;
1000 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1001 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1002 continue;
1003
1004 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1005 if (p->prefix) {
1006 reqlen = p->prefix;
1007 reqhint = ntohl(p->addr.s6_addr32[1]);
1008 if (reqlen > 32 && reqlen <= 64)
1009 reqhint &= (1U << (64 - reqlen)) - 1;
1010 }
1011
1012 #ifdef DHCPV6_OPT_PREFIX_CLASS
1013 uint8_t *xdata;
1014 uint16_t xtype, xlen;
1015 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
1016 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
1017 continue;
1018
1019 if (classes_cnt >= classes_max)
1020 continue;
1021
1022 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
1023 }
1024 #endif
1025 }
1026
1027 if (reqlen > 64)
1028 reqlen = 64;
1029 } else if (is_na) {
1030 uint8_t *sdata;
1031 uint16_t stype, slen;
1032 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1033 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1034 continue;
1035
1036 ia_addr_present = true;
1037 #ifdef DHCPV6_OPT_PREFIX_CLASS
1038 uint8_t *xdata;
1039 uint16_t xtype, xlen;
1040 struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
1041 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
1042 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
1043 continue;
1044
1045 if (classes_cnt >= classes_max)
1046 continue;
1047
1048 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
1049 }
1050 #endif
1051 }
1052 }
1053
1054 // Find assignment
1055 struct dhcpv6_assignment *c, *a = NULL;
1056 list_for_each_entry(c, &iface->ia_assignments, head) {
1057 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1058 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1059 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1060 (c->iaid == ia->iaid || c->valid_until < now) &&
1061 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1062 a = c;
1063
1064 // Reset state
1065 apply_lease(iface, a, false);
1066 memcpy(a->clid_data, clid_data, clid_len);
1067 a->clid_len = clid_len;
1068 a->iaid = ia->iaid;
1069 a->peer = *addr;
1070 a->reconf_cnt = 0;
1071 a->reconf_sent = 0;
1072 a->all_class = class_oro;
1073 a->classes_cnt = classes_cnt;
1074 a->classes = realloc(a->classes, classes_cnt * sizeof(uint16_t));
1075 if (a->classes)
1076 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
1077 break;
1078 }
1079 }
1080
1081 // Generic message handling
1082 uint16_t status = DHCPV6_STATUS_OK;
1083 if (a && a->managed_size < 0) {
1084 return -1;
1085 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1086 bool assigned = !!a;
1087
1088 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1089 a = calloc(1, sizeof(*a) + clid_len);
1090 if (a) {
1091 a->clid_len = clid_len;
1092 a->iaid = ia->iaid;
1093 a->length = reqlen;
1094 a->peer = *addr;
1095 a->assigned = reqhint;
1096 a->all_class = class_oro;
1097 a->classes_cnt = classes_cnt;
1098 if (classes_cnt) {
1099 a->classes = malloc(classes_cnt * sizeof(uint16_t));
1100 if (a->classes)
1101 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
1102 }
1103
1104 if (first)
1105 memcpy(a->key, first->key, sizeof(a->key));
1106 else
1107 odhcpd_urandom(a->key, sizeof(a->key));
1108 memcpy(a->clid_data, clid_data, clid_len);
1109
1110 if (is_pd)
1111 while (!(assigned = assign_pd(iface, a)) &&
1112 !a->managed_size && ++a->length <= 64);
1113 else
1114 assigned = assign_na(iface, a);
1115
1116 if (a->managed_size && !assigned)
1117 return -1;
1118 }
1119 }
1120
1121 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1122 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1123 } else if (assigned && !first) { //
1124 size_t handshake_len = 4;
1125 buf[0] = 0;
1126 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1127 buf[2] = 0;
1128 buf[3] = 0;
1129
1130 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1131 struct dhcpv6_auth_reconfigure auth = {
1132 htons(DHCPV6_OPT_AUTH),
1133 htons(sizeof(auth) - 4),
1134 3, 1, 0,
1135 {htonl(time(NULL)), htonl(++serial)},
1136 1,
1137 {0}
1138 };
1139 memcpy(auth.key, a->key, sizeof(a->key));
1140 memcpy(buf + handshake_len, &auth, sizeof(auth));
1141 handshake_len += sizeof(auth);
1142 }
1143
1144 buf += handshake_len;
1145 buflen -= handshake_len;
1146 response_len += handshake_len;
1147
1148 first = a;
1149 }
1150
1151 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1152
1153 // Was only a solicitation: mark binding for removal
1154 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1155 a->valid_until = 0;
1156 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1157 if (hostname_len > 0) {
1158 a->hostname = realloc(a->hostname, hostname_len + 1);
1159 if (a->hostname) {
1160 memcpy(a->hostname, hostname, hostname_len);
1161 a->hostname[hostname_len] = 0;
1162 }
1163 }
1164 a->accept_reconf = accept_reconf;
1165 apply_lease(iface, a, true);
1166 update_state = true;
1167 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1168 free_dhcpv6_assignment(a);
1169 }
1170 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1171 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1172 hdr->msg_type == DHCPV6_MSG_REBIND ||
1173 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1174 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1175 status = DHCPV6_STATUS_NOBINDING;
1176 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1177 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1178 hdr->msg_type == DHCPV6_MSG_REBIND) {
1179 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1180 if (a)
1181 apply_lease(iface, a, true);
1182 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1183 a->valid_until = 0;
1184 apply_lease(iface, a, false);
1185 update_state = true;
1186 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1187 a->clid_len = 0;
1188 a->valid_until = now + 3600; // Block address for 1h
1189 update_state = true;
1190 }
1191 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1192 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1193 status = DHCPV6_STATUS_NOTONLINK;
1194 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1195 notonlink = true;
1196 }
1197
1198 buf += ia_response_len;
1199 buflen -= ia_response_len;
1200 response_len += ia_response_len;
1201 }
1202
1203 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1204 response_len + 6 < buflen) {
1205 buf[0] = 0;
1206 buf[1] = DHCPV6_OPT_STATUS;
1207 buf[2] = 0;
1208 buf[3] = 2;
1209 buf[4] = 0;
1210 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1211 response_len += 6;
1212 }
1213
1214 if (update_state)
1215 dhcpv6_write_statefile();
1216
1217 out:
1218 return response_len;
1219 }
OpenWrt DHCP Server