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