projects / project / odhcpd.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
backup for notonlink
[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 pref = 3600;
722 uint32_t valid = 3600;
723
724 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
725 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
726
727 for (size_t i = 0; i < addrlen; ++i) {
728 bool match = true;
729 if (addrs[i].has_class) {
730 match = false;
731 if (a->classes_cnt) {
732 for (size_t j = 0; j < a->classes_cnt; ++j)
733 if (a->classes[j] == addrs[i].class)
734 match = true;
735 } else if (a->all_class) {
736 match = true;
737 }
738 }
739
740 if (!match)
741 continue;
742
743 uint32_t prefix_pref = addrs[i].preferred - now;
744 uint32_t prefix_valid = addrs[i].valid - now;
745
746 if (addrs[i].prefix > 96 ||
747 addrs[i].preferred <= (uint32_t)now)
748 continue;
749
750 if (prefix_pref > 86400)
751 prefix_pref = 86400;
752
753 if (prefix_valid > 86400)
754 prefix_valid = 86400;
755
756 #ifdef DHCPV6_OPT_PREFIX_CLASS
757 struct {
758 uint16_t code;
759 uint16_t length;
760 uint16_t class;
761 } pclass = {htons(DHCPV6_OPT_PREFIX_CLASS),
762 htons(2), htons(iface->ia_addr[i].class)};
763 #endif
764
765 if (a->length < 128) {
766 struct dhcpv6_ia_prefix p = {
767 .type = htons(DHCPV6_OPT_IA_PREFIX),
768 .len = htons(sizeof(p) - 4),
769 .preferred = htonl(prefix_pref),
770 .valid = htonl(prefix_valid),
771 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
772 .addr = addrs[i].addr
773 };
774 p.addr.s6_addr32[1] |= htonl(a->assigned);
775
776 size_t entrlen = sizeof(p) - 4;
777
778 #ifdef DHCPV6_OPT_PREFIX_CLASS
779 if (iface->ia_addr[i].has_class) {
780 entrlen += sizeof(pclass);
781 p.len = htons(entrlen);
782 }
783 #endif
784
785 if (datalen + entrlen + 4 > buflen ||
786 (a->assigned == 0 && a->managed_size == 0))
787 continue;
788
789 memcpy(buf + datalen, &p, sizeof(p));
790 #ifdef DHCPV6_OPT_PREFIX_CLASS
791 memcpy(buf + datalen + sizeof(p), &pclass, sizeof(pclass));
792 #endif
793 datalen += entrlen + 4;
794 } else {
795 struct dhcpv6_ia_addr n = {
796 .type = htons(DHCPV6_OPT_IA_ADDR),
797 .len = htons(sizeof(n) - 4),
798 .addr = addrs[i].addr,
799 .preferred = htonl(prefix_pref),
800 .valid = htonl(prefix_valid)
801 };
802 n.addr.s6_addr32[3] = htonl(a->assigned);
803 size_t entrlen = sizeof(n) - 4;
804
805 #ifdef DHCPV6_OPT_PREFIX_CLASS
806 if (iface->ia_addr[i].has_class) {
807 entrlen += sizeof(pclass);
808 n.len = htons(entrlen);
809 }
810 #endif
811
812 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
813 continue;
814
815 memcpy(buf + datalen, &n, sizeof(n));
816 #ifdef DHCPV6_OPT_PREFIX_CLASS
817 memcpy(buf + datalen + sizeof(n), &pclass, sizeof(pclass));
818 #endif
819 datalen += entrlen + 4;
820 }
821
822 // Calculate T1 / T2 based on non-deprecated addresses
823 if (prefix_pref > 0) {
824 if (prefix_pref < pref)
825 pref = prefix_pref;
826
827 if (prefix_valid < valid)
828 valid = prefix_valid;
829 }
830 }
831
832 a->valid_until = valid + now;
833 out.t1 = htonl(pref * 5 / 10);
834 out.t2 = htonl(pref * 8 / 10);
835
836 if (!out.t1)
837 out.t1 = htonl(1);
838
839 if (!out.t2)
840 out.t2 = htonl(1);
841 }
842
843 if (!request) {
844 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
845 uint16_t otype, olen;
846 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
847 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
848 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
849 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
850 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
851 continue;
852
853 bool found = false;
854 if (a) {
855 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
856 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
857
858 for (size_t i = 0; i < addrlen; ++i) {
859 if (addrs[i].prefix > 96 ||
860 addrs[i].preferred <= (uint32_t)now)
861 continue;
862
863 struct in6_addr addr = addrs[i].addr;
864 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
865 addr.s6_addr32[1] |= htonl(a->assigned);
866
867 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
868 p->prefix == a->length)
869 found = true;
870 } else {
871 addr.s6_addr32[3] = htonl(a->assigned);
872
873 if (!memcmp(&n->addr, &addr, sizeof(addr)))
874 found = true;
875 }
876 }
877 }
878
879 if (!found) {
880 if (otype == DHCPV6_OPT_IA_PREFIX) {
881 struct dhcpv6_ia_prefix inv = {
882 .type = htons(DHCPV6_OPT_IA_PREFIX),
883 .len = htons(sizeof(inv) - 4),
884 .preferred = 0,
885 .valid = 0,
886 .prefix = p->prefix,
887 .addr = p->addr
888 };
889
890 if (datalen + sizeof(inv) > buflen)
891 continue;
892
893 memcpy(buf + datalen, &inv, sizeof(inv));
894 datalen += sizeof(inv);
895 } else {
896 struct dhcpv6_ia_addr inv = {
897 .type = htons(DHCPV6_OPT_IA_ADDR),
898 .len = htons(sizeof(inv) - 4),
899 .addr = n->addr,
900 .preferred = 0,
901 .valid = 0
902 };
903
904 if (datalen + sizeof(inv) > buflen)
905 continue;
906
907 memcpy(buf + datalen, &inv, sizeof(inv));
908 datalen += sizeof(inv);
909 }
910 }
911 }
912 }
913 }
914
915 out.len = htons(datalen - 4);
916 memcpy(buf, &out, sizeof(out));
917 return datalen;
918 }
919
920
921 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
922 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
923 {
924 time_t now = odhcpd_time();
925 size_t response_len = 0;
926 const struct dhcpv6_client_header *hdr = data;
927 uint8_t *start = (uint8_t*)&hdr[1], *odata;
928 uint16_t otype, olen;
929
930 // Find and parse client-id and hostname
931 bool accept_reconf = false;
932 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
933 char hostname[256];
934 size_t hostname_len = 0;
935 bool class_oro = false;
936 bool notonlink = false;
937
938 dhcpv6_for_each_option(start, end, otype, olen, odata) {
939 if (otype == DHCPV6_OPT_CLIENTID) {
940 clid_data = odata;
941 clid_len = olen;
942
943 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
944 memcpy(mac, &odata[8], sizeof(mac));
945 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
946 memcpy(mac, &odata[4], sizeof(mac));
947 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
948 uint8_t fqdn_buf[256];
949 memcpy(fqdn_buf, odata, olen);
950 fqdn_buf[olen++] = 0;
951
952 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
953 hostname_len = strcspn(hostname, ".");
954 } else if (otype == DHCPV6_OPT_ORO) {
955 #ifdef DHCPV6_OPT_PREFIX_CLASS
956 for (size_t i = 0; i + 1 < olen; i += 2) {
957 if (odata[i] == (DHCPV6_OPT_PREFIX_CLASS >> 8) &&
958 odata[i + 1] == (DHCPV6_OPT_PREFIX_CLASS & 0xff))
959 class_oro = true;
960 }
961 #endif
962 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
963 accept_reconf = true;
964 }
965 }
966
967 if (!clid_data || !clid_len || clid_len > 130)
968 goto out;
969
970 update(iface);
971 bool update_state = false;
972
973 struct dhcpv6_assignment *first = NULL;
974 dhcpv6_for_each_option(start, end, otype, olen, odata) {
975 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
976 bool is_na = (otype == DHCPV6_OPT_IA_NA);
977 bool ia_addr_present = false;
978 if (!is_pd && !is_na)
979 continue;
980
981 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
982 size_t ia_response_len = 0;
983 uint8_t reqlen = (is_pd) ? 62 : 128;
984 uint32_t reqhint = 0;
985
986 const uint8_t classes_max = 32;
987 uint8_t classes_cnt = 0;
988 uint16_t classes[classes_max];
989
990 // Parse request hint for IA-PD
991 if (is_pd) {
992 uint8_t *sdata;
993 uint16_t stype, slen;
994 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
995 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
996 continue;
997
998 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
999 if (p->prefix) {
1000 reqlen = p->prefix;
1001 reqhint = ntohl(p->addr.s6_addr32[1]);
1002 if (reqlen > 32 && reqlen <= 64)
1003 reqhint &= (1U << (64 - reqlen)) - 1;
1004 }
1005
1006 #ifdef DHCPV6_OPT_PREFIX_CLASS
1007 uint8_t *xdata;
1008 uint16_t xtype, xlen;
1009 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
1010 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
1011 continue;
1012
1013 if (classes_cnt >= classes_max)
1014 continue;
1015
1016 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
1017 }
1018 #endif
1019 }
1020
1021 if (reqlen > 64)
1022 reqlen = 64;
1023 } else if (is_na) {
1024 uint8_t *sdata;
1025 uint16_t stype, slen;
1026 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1027 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1028 continue;
1029
1030 ia_addr_present = true;
1031 #ifdef DHCPV6_OPT_PREFIX_CLASS
1032 uint8_t *xdata;
1033 uint16_t xtype, xlen;
1034 struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
1035 dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
1036 if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
1037 continue;
1038
1039 if (classes_cnt >= classes_max)
1040 continue;
1041
1042 classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
1043 }
1044 #endif
1045 }
1046 }
1047
1048 // Find assignment
1049 struct dhcpv6_assignment *c, *a = NULL;
1050 list_for_each_entry(c, &iface->ia_assignments, head) {
1051 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1052 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1053 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1054 (c->iaid == ia->iaid || c->valid_until < now) &&
1055 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1056 a = c;
1057
1058 // Reset state
1059 apply_lease(iface, a, false);
1060 memcpy(a->clid_data, clid_data, clid_len);
1061 a->clid_len = clid_len;
1062 a->iaid = ia->iaid;
1063 a->peer = *addr;
1064 a->reconf_cnt = 0;
1065 a->reconf_sent = 0;
1066 a->all_class = class_oro;
1067 a->classes_cnt = classes_cnt;
1068 a->classes = realloc(a->classes, classes_cnt * sizeof(uint16_t));
1069 if (a->classes)
1070 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
1071 break;
1072 }
1073 }
1074
1075 // Generic message handling
1076 uint16_t status = DHCPV6_STATUS_OK;
1077 if (a && a->managed_size < 0) {
1078 return -1;
1079 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1080 bool assigned = !!a;
1081
1082 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1083 a = calloc(1, sizeof(*a) + clid_len);
1084 if (a) {
1085 a->clid_len = clid_len;
1086 a->iaid = ia->iaid;
1087 a->length = reqlen;
1088 a->peer = *addr;
1089 a->assigned = reqhint;
1090 a->all_class = class_oro;
1091 a->classes_cnt = classes_cnt;
1092 if (classes_cnt) {
1093 a->classes = malloc(classes_cnt * sizeof(uint16_t));
1094 if (a->classes)
1095 memcpy(a->classes, classes, classes_cnt * sizeof(uint16_t));
1096 }
1097
1098 if (first)
1099 memcpy(a->key, first->key, sizeof(a->key));
1100 else
1101 odhcpd_urandom(a->key, sizeof(a->key));
1102 memcpy(a->clid_data, clid_data, clid_len);
1103
1104 if (is_pd)
1105 while (!(assigned = assign_pd(iface, a)) &&
1106 !a->managed_size && ++a->length <= 64);
1107 else
1108 assigned = assign_na(iface, a);
1109
1110 if (a->managed_size && !assigned)
1111 return -1;
1112 }
1113 }
1114
1115 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1116 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1117 } else if (assigned && !first) { //
1118 size_t handshake_len = 4;
1119 buf[0] = 0;
1120 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1121 buf[2] = 0;
1122 buf[3] = 0;
1123
1124 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1125 struct dhcpv6_auth_reconfigure auth = {
1126 htons(DHCPV6_OPT_AUTH),
1127 htons(sizeof(auth) - 4),
1128 3, 1, 0,
1129 {htonl(time(NULL)), htonl(++serial)},
1130 1,
1131 {0}
1132 };
1133 memcpy(auth.key, a->key, sizeof(a->key));
1134 memcpy(buf + handshake_len, &auth, sizeof(auth));
1135 handshake_len += sizeof(auth);
1136 }
1137
1138 buf += handshake_len;
1139 buflen -= handshake_len;
1140 response_len += handshake_len;
1141
1142 first = a;
1143 }
1144
1145 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1146
1147 // Was only a solicitation: mark binding for removal
1148 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1149 a->valid_until = 0;
1150 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1151 if (hostname_len > 0) {
1152 a->hostname = realloc(a->hostname, hostname_len + 1);
1153 if (a->hostname) {
1154 memcpy(a->hostname, hostname, hostname_len);
1155 a->hostname[hostname_len] = 0;
1156 }
1157 }
1158 a->accept_reconf = accept_reconf;
1159 apply_lease(iface, a, true);
1160 update_state = true;
1161 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1162 free_dhcpv6_assignment(a);
1163 }
1164 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1165 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1166 hdr->msg_type == DHCPV6_MSG_REBIND ||
1167 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1168 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1169 status = DHCPV6_STATUS_NOBINDING;
1170 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1171 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1172 hdr->msg_type == DHCPV6_MSG_REBIND) {
1173 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1174 if (a)
1175 apply_lease(iface, a, true);
1176 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1177 a->valid_until = 0;
1178 apply_lease(iface, a, false);
1179 update_state = true;
1180 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1181 a->clid_len = 0;
1182 a->valid_until = now + 3600; // Block address for 1h
1183 update_state = true;
1184 }
1185 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1186 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1187 status = DHCPV6_STATUS_NOTONLINK;
1188 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1189 notonlink = true;
1190 }
1191
1192 buf += ia_response_len;
1193 buflen -= ia_response_len;
1194 response_len += ia_response_len;
1195 }
1196
1197 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1198 response_len + 6 < buflen) {
1199 buf[0] = 0;
1200 buf[1] = DHCPV6_OPT_STATUS;
1201 buf[2] = 0;
1202 buf[3] = 2;
1203 buf[4] = 0;
1204 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1205 response_len += 6;
1206 }
1207
1208 if (update_state)
1209 dhcpv6_write_statefile();
1210
1211 out:
1212 return response_len;
1213 }
OpenWrt DHCP Server