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treewide: simplify dhcp leasetime checking
[project/odhcpd.git] / src / dhcpv6-ia.c
1 /**
2 * Copyright (C) 2013 Steven Barth <steven@midlink.org>
3 * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License v2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16 #include "odhcpd.h"
17 #include "dhcpv6.h"
18 #include "dhcpv4.h"
19 #include "libubox/md5.h"
20 #include "libubox/usock.h"
21
22 #include <time.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <stdio.h>
26 #include <poll.h>
27 #include <alloca.h>
28 #include <resolv.h>
29 #include <limits.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include <stdbool.h>
34 #include <arpa/inet.h>
35 #include <sys/timerfd.h>
36
37 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
38 ((iface)->managed == RELAYD_MANAGED_NO_AFLAG || (i) == (m) || \
39 (addrs)[(i)].prefix > 64)
40
41 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
42 static void reconf_timer(struct uloop_timeout *event);
43 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
44 static uint32_t serial = 0;
45 static uint8_t statemd5[16];
46
47 int dhcpv6_ia_init(void)
48 {
49 uloop_timeout_set(&reconf_event, 2000);
50 return 0;
51 }
52
53 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
54 {
55 if (!enable && iface->ia_assignments.next) {
56 struct dhcpv6_assignment *c;
57
58 while (!list_empty(&iface->ia_assignments)) {
59 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
60 free_dhcpv6_assignment(c);
61 }
62 }
63
64 if (enable && iface->dhcpv6 == RELAYD_SERVER) {
65 if (!iface->ia_assignments.next)
66 INIT_LIST_HEAD(&iface->ia_assignments);
67
68 if (list_empty(&iface->ia_assignments)) {
69 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
70 if (!border) {
71 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
72 return -1;
73 }
74
75 border->length = 64;
76 list_add(&border->head, &iface->ia_assignments);
77 }
78
79 /* Parse static entries */
80 struct lease *lease;
81 list_for_each_entry(lease, &leases, head) {
82 /* Construct entry */
83 size_t duid_len = lease->duid_len ? lease->duid_len : 14;
84 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
85 if (!a) {
86 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
87 iface->ifname);
88 return -1;
89 }
90
91 a->leasetime = lease->dhcpv4_leasetime;
92
93 a->clid_len = duid_len;
94 a->length = 128;
95 if (lease->hostid) {
96 a->assigned = lease->hostid;
97 } else {
98 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
99 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
100 }
101
102 odhcpd_urandom(a->key, sizeof(a->key));
103 memcpy(a->clid_data, lease->duid, lease->duid_len);
104 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
105 /* Static assignment */
106 a->flags |= OAF_STATIC;
107 /* Infinite valid */
108 a->valid_until = 0;
109
110 /* Assign to all interfaces */
111 struct dhcpv6_assignment *c;
112 list_for_each_entry(c, &iface->ia_assignments, head) {
113 if (c->length != 128 || c->assigned > a->assigned) {
114 list_add_tail(&a->head, &c->head);
115 break;
116 } else if (c->assigned == a->assigned)
117 /* Already an assignment with that number */
118 break;
119 }
120
121 if (a->head.next) {
122 if (lease->hostname[0]) {
123 free(a->hostname);
124 a->hostname = strdup(lease->hostname);
125 }
126 } else
127 free_dhcpv6_assignment(a);
128 }
129 }
130 return 0;
131 }
132
133 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
134 {
135 if (c->managed_sock.fd.registered) {
136 ustream_free(&c->managed_sock.stream);
137 close(c->managed_sock.fd.fd);
138 }
139
140 if (c->head.next)
141 list_del(&c->head);
142
143 free(c->managed);
144 free(c->hostname);
145 free(c);
146 }
147
148 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
149 {
150 return (a->managed_size || a->length > prefix_length);
151 }
152
153 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
154 {
155 return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
156 }
157
158 static size_t elect_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
159 {
160 size_t i, m;
161
162 for (i = 0, m = 0; i < addrlen; ++i) {
163 if (addrs[i].preferred > addrs[m].preferred ||
164 (addrs[i].preferred == addrs[m].preferred &&
165 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
166 m = i;
167 }
168
169 return m;
170 }
171
172 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
173 {
174 struct {
175 struct dhcpv6_client_header hdr;
176 uint16_t srvid_type;
177 uint16_t srvid_len;
178 uint16_t duid_type;
179 uint16_t hardware_type;
180 uint8_t mac[6];
181 uint16_t msg_type;
182 uint16_t msg_len;
183 uint8_t msg_id;
184 struct dhcpv6_auth_reconfigure auth;
185 uint16_t clid_type;
186 uint16_t clid_len;
187 uint8_t clid_data[128];
188 } __attribute__((packed)) reconf_msg = {
189 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
190 .srvid_type = htons(DHCPV6_OPT_SERVERID),
191 .srvid_len = htons(10),
192 .duid_type = htons(3),
193 .hardware_type = htons(1),
194 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
195 .msg_len = htons(1),
196 .msg_id = DHCPV6_MSG_RENEW,
197 .auth = {htons(DHCPV6_OPT_AUTH),
198 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
199 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
200 .clid_type = htons(DHCPV6_OPT_CLIENTID),
201 .clid_len = htons(assign->clid_len),
202 .clid_data = {0},
203 };
204
205 odhcpd_get_mac(iface, reconf_msg.mac);
206 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
207 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
208
209 md5_ctx_t md5;
210 uint8_t secretbytes[64];
211 memset(secretbytes, 0, sizeof(secretbytes));
212 memcpy(secretbytes, assign->key, sizeof(assign->key));
213
214 for (size_t i = 0; i < sizeof(secretbytes); ++i)
215 secretbytes[i] ^= 0x36;
216
217 md5_begin(&md5);
218 md5_hash(secretbytes, sizeof(secretbytes), &md5);
219 md5_hash(iov.iov_base, iov.iov_len, &md5);
220 md5_end(reconf_msg.auth.key, &md5);
221
222 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
223 secretbytes[i] ^= 0x36;
224 secretbytes[i] ^= 0x5c;
225 }
226
227 md5_begin(&md5);
228 md5_hash(secretbytes, sizeof(secretbytes), &md5);
229 md5_hash(reconf_msg.auth.key, 16, &md5);
230 md5_end(reconf_msg.auth.key, &md5);
231
232 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
233 }
234
235 void dhcpv6_write_statefile(void)
236 {
237 md5_ctx_t md5;
238 md5_begin(&md5);
239
240 if (config.dhcp_statefile) {
241 time_t now = odhcpd_time(), wall_time = time(NULL);
242 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
243 if (fd < 0)
244 return;
245
246 lockf(fd, F_LOCK, 0);
247 if (ftruncate(fd, 0) < 0) {}
248
249 FILE *fp = fdopen(fd, "w");
250 if (!fp) {
251 close(fd);
252 return;
253 }
254
255 struct interface *iface;
256 list_for_each_entry(iface, &interfaces, head) {
257 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
258 continue;
259
260 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
261 struct dhcpv6_assignment *c;
262 list_for_each_entry(c, &iface->ia_assignments, head) {
263 if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
264 continue;
265
266 char ipbuf[INET6_ADDRSTRLEN];
267 char leasebuf[512];
268 char duidbuf[264];
269 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
270
271 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
272 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
273 iface->ifname, duidbuf, ntohl(c->iaid),
274 (c->hostname ? c->hostname : "-"),
275 (c->valid_until > now ?
276 (c->valid_until - now + wall_time) :
277 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
278 c->assigned, (unsigned)c->length);
279
280 struct in6_addr addr;
281 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
282 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
283 size_t m = elect_addr(addrs, addrlen);
284
285 for (size_t i = 0; i < addrlen; ++i) {
286 if (!valid_addr(&addrs[i], now) ||
287 (!INFINITE_VALID(c->valid_until) && c->valid_until <= now))
288 continue;
289
290 addr = addrs[i].addr;
291 if (c->length == 128) {
292 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
293 continue;
294
295 addr.s6_addr32[3] = htonl(c->assigned);
296 }
297 else {
298 if (!valid_prefix_length(c, addrs[i].prefix))
299 continue;
300
301 addr.s6_addr32[1] |= htonl(c->assigned);
302 }
303
304 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
305
306 if (c->length == 128 && c->hostname) {
307 fputs(ipbuf, fp);
308
309 char b[256];
310 if (dn_expand(iface->search, iface->search + iface->search_len,
311 iface->search, b, sizeof(b)) > 0)
312 fprintf(fp, "\t%s.%s", c->hostname, b);
313
314 fprintf(fp, "\t%s\n", c->hostname);
315 md5_hash(ipbuf, strlen(ipbuf), &md5);
316 md5_hash(c->hostname, strlen(c->hostname), &md5);
317 }
318
319 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
320 (c->managed_size) ? addrs[i].prefix : c->length);
321 }
322 leasebuf[l - 1] = '\n';
323 fwrite(leasebuf, 1, l, fp);
324 }
325 }
326
327 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
328 struct dhcpv4_assignment *c;
329 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
330 if (!(c->flags & OAF_BOUND))
331 continue;
332
333 char ipbuf[INET6_ADDRSTRLEN];
334 char leasebuf[512];
335 char duidbuf[16];
336 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
337
338 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
339 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
340 iface->ifname, duidbuf,
341 (c->hostname ? c->hostname : "-"),
342 (c->valid_until > now ?
343 (c->valid_until - now + wall_time) :
344 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
345 c->addr);
346
347 struct in_addr addr = {htonl(c->addr)};
348 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
349
350 if (c->hostname) {
351 fputs(ipbuf, fp);
352
353 char b[256];
354 if (dn_expand(iface->search, iface->search + iface->search_len,
355 iface->search, b, sizeof(b)) > 0)
356 fprintf(fp, "\t%s.%s", c->hostname, b);
357
358 fprintf(fp, "\t%s\n", c->hostname);
359 md5_hash(ipbuf, strlen(ipbuf), &md5);
360 md5_hash(c->hostname, strlen(c->hostname), &md5);
361 }
362
363 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
364 leasebuf[l - 1] = '\n';
365 fwrite(leasebuf, 1, l, fp);
366 }
367 }
368 }
369
370 fclose(fp);
371 }
372
373 uint8_t newmd5[16];
374 md5_end(newmd5, &md5);
375
376 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
377 memcpy(statemd5, newmd5, sizeof(statemd5));
378 char *argv[2] = {config.dhcp_cb, NULL};
379 if (!vfork()) {
380 execv(argv[0], argv);
381 _exit(128);
382 }
383 }
384 }
385
386
387 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
388 {
389 if (a->length > 64 || a->managed_size < 0)
390 return;
391
392 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
393 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
394
395 for (size_t i = 0; i < addrlen; ++i) {
396 struct in6_addr prefix = addrs[i].addr;
397 prefix.s6_addr32[1] |= htonl(a->assigned);
398 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
399 iface, &a->peer.sin6_addr, 1024, add);
400 }
401 }
402
403 /* More data was received from TCP connection */
404 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
405 {
406 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
407 time_t now = odhcpd_time();
408 bool first = c->managed_size < 0;
409
410 for (;;) {
411 int pending;
412 char *data = ustream_get_read_buf(s, &pending);
413 char *end = memmem(data, pending, "\n\n", 2);
414
415 if (!end)
416 break;
417
418 end += 2;
419 end[-1] = 0;
420
421 c->managed_size = 0;
422 if (c->accept_reconf)
423 c->reconf_cnt = 1;
424
425 char *saveptr;
426 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
427 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
428 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
429
430 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
431 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
432 continue;
433
434 x = strtok_r(NULL, ",", &saveptr2);
435 if (sscanf(x, "%hhu", &n->prefix) < 1)
436 continue;
437
438 x = strtok_r(NULL, ",", &saveptr2);
439 if (sscanf(x, "%u", &n->preferred) < 1)
440 continue;
441
442 x = strtok_r(NULL, ",", &saveptr2);
443 if (sscanf(x, "%u", &n->valid) < 1)
444 continue;
445
446 if (n->preferred > n->valid)
447 continue;
448
449 if (UINT32_MAX - now < n->preferred)
450 n->preferred = UINT32_MAX;
451 else
452 n->preferred += now;
453
454 if (UINT32_MAX - now < n->valid)
455 n->valid = UINT32_MAX;
456 else
457 n->valid += now;
458
459 n->dprefix = 0;
460
461 ++c->managed_size;
462 }
463
464 ustream_consume(s, end - data);
465 }
466
467 if (first && c->managed_size == 0)
468 free_dhcpv6_assignment(c);
469 else if (first && !(c->flags & OAF_STATIC))
470 c->valid_until = now + 150;
471 }
472
473
474 /* TCP transmission has ended, either because of success or timeout or other error */
475 static void managed_handle_pd_done(struct ustream *s)
476 {
477 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
478
479 if (!(c->flags & OAF_STATIC))
480 c->valid_until = odhcpd_time() + 15;
481
482 c->managed_size = 0;
483
484 if (c->accept_reconf)
485 c->reconf_cnt = 1;
486 }
487
488 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
489 {
490 struct dhcpv6_assignment *c;
491
492 if (iface->dhcpv6_pd_manager[0]) {
493 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
494 if (fd >= 0) {
495 char iaidbuf[298];
496 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
497
498 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
499 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
500 ustream_fd_init(&assign->managed_sock, fd);
501 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
502 iaidbuf, assign->iaid, assign->length);
503 ustream_write_pending(&assign->managed_sock.stream);
504 assign->managed_size = -1;
505
506 if (!(assign->flags & OAF_STATIC))
507 assign->valid_until = odhcpd_time() + 15;
508
509 list_add(&assign->head, &iface->ia_assignments);
510
511 /* Wait initial period of up to 250ms for immediate assignment */
512 struct pollfd pfd = { .fd = fd, .events = POLLIN };
513 poll(&pfd, 1, 250);
514 managed_handle_pd_data(&assign->managed_sock.stream, 0);
515
516 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
517 return true;
518 }
519
520 return false;
521 } else if (iface->ia_addr_len < 1)
522 return false;
523
524 /* Try honoring the hint first */
525 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
526 if (assign->assigned) {
527 list_for_each_entry(c, &iface->ia_assignments, head) {
528 if (c->length == 128 || c->length == 0)
529 continue;
530
531 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
532 list_add_tail(&assign->head, &c->head);
533
534 if (assign->flags & OAF_BOUND)
535 apply_lease(iface, assign, true);
536
537 return true;
538 }
539
540 if (c->assigned != 0)
541 current = (c->assigned + (1 << (64 - c->length)));
542 }
543 }
544
545 /* Fallback to a variable assignment */
546 current = 1;
547 list_for_each_entry(c, &iface->ia_assignments, head) {
548 if (c->length == 128 || c->length == 0)
549 continue;
550
551 current = (current + asize) & (~asize);
552 if (current + asize < c->assigned) {
553 assign->assigned = current;
554 list_add_tail(&assign->head, &c->head);
555
556 if (assign->flags & OAF_BOUND)
557 apply_lease(iface, assign, true);
558
559 return true;
560 }
561
562 if (c->assigned != 0)
563 current = (c->assigned + (1 << (64 - c->length)));
564 }
565
566 return false;
567 }
568
569 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
570 {
571 /* Seed RNG with checksum of DUID */
572 uint32_t seed = 0;
573 for (size_t i = 0; i < assign->clid_len; ++i)
574 seed += assign->clid_data[i];
575 srand(seed);
576
577 /* Try to assign up to 100x */
578 for (size_t i = 0; i < 100; ++i) {
579 uint32_t try;
580 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
581
582 struct dhcpv6_assignment *c;
583 list_for_each_entry(c, &iface->ia_assignments, head) {
584 if (c->length == 0)
585 continue;
586
587 if (c->assigned > try || c->length != 128) {
588 assign->assigned = try;
589 list_add_tail(&assign->head, &c->head);
590 return true;
591 } else if (c->assigned == try)
592 break;
593 }
594 }
595
596 return false;
597 }
598
599 void dhcpv6_ia_preupdate(struct interface *iface)
600 {
601 if (iface->dhcpv6 != RELAYD_SERVER)
602 return;
603
604 struct dhcpv6_assignment *c, *border = list_last_entry(
605 &iface->ia_assignments, struct dhcpv6_assignment, head);
606
607 list_for_each_entry(c, &iface->ia_assignments, head)
608 if (c != border && !iface->managed && (c->flags & OAF_BOUND))
609 apply_lease(iface, c, false);
610 }
611
612 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
613 {
614 if (iface->dhcpv6 != RELAYD_SERVER)
615 return;
616
617 int minprefix = -1;
618 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
619 if (iface->ia_addr[i].preferred > (uint32_t)now &&
620 iface->ia_addr[i].prefix < 64 &&
621 iface->ia_addr[i].prefix > minprefix)
622 minprefix = iface->ia_addr[i].prefix;
623 }
624
625 struct dhcpv6_assignment *border = list_last_entry(
626 &iface->ia_assignments, struct dhcpv6_assignment, head);
627
628 if (minprefix > 32 && minprefix <= 64)
629 border->assigned = 1U << (64 - minprefix);
630 else
631 border->assigned = 0;
632
633 struct list_head reassign = LIST_HEAD_INIT(reassign);
634 struct dhcpv6_assignment *c, *d;
635 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
636 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
637 c->managed_size)
638 continue;
639
640 if (c->length < 128 && c->assigned >= border->assigned && c != border)
641 list_move(&c->head, &reassign);
642 else if (c != border && (c->flags & OAF_BOUND))
643 apply_lease(iface, c, true);
644
645 if (c->accept_reconf && c->reconf_cnt == 0) {
646 c->reconf_cnt = 1;
647 c->reconf_sent = now;
648 send_reconf(iface, c);
649
650 /* Leave all other assignments of that client alone */
651 struct dhcpv6_assignment *a;
652 list_for_each_entry(a, &iface->ia_assignments, head)
653 if (a != c && a->clid_len == c->clid_len &&
654 !memcmp(a->clid_data, c->clid_data, a->clid_len))
655 c->reconf_cnt = INT_MAX;
656 }
657 }
658
659 while (!list_empty(&reassign)) {
660 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
661 list_del(&c->head);
662 if (!assign_pd(iface, c)) {
663 c->assigned = 0;
664 list_add(&c->head, &iface->ia_assignments);
665 }
666 }
667
668 dhcpv6_write_statefile();
669 }
670
671 static void reconf_timer(struct uloop_timeout *event)
672 {
673 time_t now = odhcpd_time();
674 struct interface *iface;
675 list_for_each_entry(iface, &interfaces, head) {
676 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
677 continue;
678
679 struct dhcpv6_assignment *a, *n;
680 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
681 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
682 if ((a->length < 128 && a->clid_len > 0) ||
683 (a->length == 128 && a->clid_len == 0))
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 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
698 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
699 struct interface *iface, bool request)
700 {
701 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
702 return 0;
703
704 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
705 size_t datalen = sizeof(out);
706 time_t now = odhcpd_time();
707
708 if (status) {
709 struct __attribute__((packed)) {
710 uint16_t type;
711 uint16_t len;
712 uint16_t value;
713 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
714 htons(status)};
715
716 memcpy(buf + datalen, &stat, sizeof(stat));
717 datalen += sizeof(stat);
718 } else {
719 if (a) {
720 uint32_t leasetime;
721 if (a->leasetime)
722 leasetime = a->leasetime;
723 else
724 leasetime = iface->dhcpv4_leasetime;
725
726 uint32_t pref = leasetime;
727 uint32_t valid = leasetime;
728
729 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
730 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
731 size_t m = elect_addr(addrs, addrlen);
732
733 for (size_t i = 0; i < addrlen; ++i) {
734 uint32_t prefix_pref = addrs[i].preferred;
735 uint32_t prefix_valid = addrs[i].valid;
736
737 if (!valid_addr(&addrs[i], now))
738 continue;
739
740 if (prefix_pref != UINT32_MAX)
741 prefix_pref -= now;
742
743 if (prefix_valid != UINT32_MAX)
744 prefix_valid -= now;
745
746 if (a->length < 128) {
747 struct dhcpv6_ia_prefix p = {
748 .type = htons(DHCPV6_OPT_IA_PREFIX),
749 .len = htons(sizeof(p) - 4),
750 .preferred = htonl(prefix_pref),
751 .valid = htonl(prefix_valid),
752 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
753 .addr = addrs[i].addr
754 };
755 p.addr.s6_addr32[1] |= htonl(a->assigned);
756
757 size_t entrlen = sizeof(p) - 4;
758
759 if (datalen + entrlen + 4 > buflen ||
760 (a->assigned == 0 && a->managed_size == 0) ||
761 !valid_prefix_length(a, addrs[i].prefix))
762 continue;
763
764 memcpy(buf + datalen, &p, sizeof(p));
765 datalen += entrlen + 4;
766 } else {
767 struct dhcpv6_ia_addr n = {
768 .type = htons(DHCPV6_OPT_IA_ADDR),
769 .len = htons(sizeof(n) - 4),
770 .addr = addrs[i].addr,
771 .preferred = htonl(prefix_pref),
772 .valid = htonl(prefix_valid)
773 };
774 n.addr.s6_addr32[3] = htonl(a->assigned);
775 size_t entrlen = sizeof(n) - 4;
776
777 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
778 a->assigned == 0 ||
779 datalen + entrlen + 4 > buflen)
780 continue;
781
782 memcpy(buf + datalen, &n, sizeof(n));
783 datalen += entrlen + 4;
784 }
785
786 /* Calculate T1 / T2 based on non-deprecated addresses */
787 if (prefix_pref > 0) {
788 if (prefix_pref < pref)
789 pref = prefix_pref;
790
791 if (prefix_valid < valid)
792 valid = prefix_valid;
793 }
794 }
795
796 if (!INFINITE_VALID(a->valid_until))
797 /* UINT32_MAX is considered as infinite leasetime */
798 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
799
800 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
801 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
802
803 if (!out.t1)
804 out.t1 = htonl(1);
805
806 if (!out.t2)
807 out.t2 = htonl(1);
808 }
809
810 if (!request) {
811 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
812 uint16_t otype, olen;
813 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
814 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
815 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
816 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
817 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
818 continue;
819
820 bool found = false;
821 if (a) {
822 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
823 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
824
825 for (size_t i = 0; i < addrlen; ++i) {
826 if (!valid_addr(&addrs[i], now))
827 continue;
828
829 struct in6_addr addr = addrs[i].addr;
830 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
831 addr.s6_addr32[1] |= htonl(a->assigned);
832
833 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
834 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
835 found = true;
836 } else {
837 addr.s6_addr32[3] = htonl(a->assigned);
838
839 if (!memcmp(&n->addr, &addr, sizeof(addr)))
840 found = true;
841 }
842 }
843 }
844
845 if (!found) {
846 if (otype == DHCPV6_OPT_IA_PREFIX) {
847 struct dhcpv6_ia_prefix inv = {
848 .type = htons(DHCPV6_OPT_IA_PREFIX),
849 .len = htons(sizeof(inv) - 4),
850 .preferred = 0,
851 .valid = 0,
852 .prefix = p->prefix,
853 .addr = p->addr
854 };
855
856 if (datalen + sizeof(inv) > buflen)
857 continue;
858
859 memcpy(buf + datalen, &inv, sizeof(inv));
860 datalen += sizeof(inv);
861 } else {
862 struct dhcpv6_ia_addr inv = {
863 .type = htons(DHCPV6_OPT_IA_ADDR),
864 .len = htons(sizeof(inv) - 4),
865 .addr = n->addr,
866 .preferred = 0,
867 .valid = 0
868 };
869
870 if (datalen + sizeof(inv) > buflen)
871 continue;
872
873 memcpy(buf + datalen, &inv, sizeof(inv));
874 datalen += sizeof(inv);
875 }
876 }
877 }
878 }
879 }
880
881 out.len = htons(datalen - 4);
882 memcpy(buf, &out, sizeof(out));
883 return datalen;
884 }
885
886 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
887 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
888 {
889 const char *type = "UNKNOWN";
890 const char *status = "UNKNOWN";
891
892 if (msgtype == DHCPV6_MSG_RENEW)
893 return;
894
895 switch (msgtype) {
896 case DHCPV6_MSG_SOLICIT:
897 type = "SOLICIT";
898 break;
899 case DHCPV6_MSG_REQUEST:
900 type = "REQUEST";
901 break;
902 case DHCPV6_MSG_CONFIRM:
903 type = "CONFIRM";
904 break;
905 case DHCPV6_MSG_RENEW:
906 type = "RENEW";
907 break;
908 case DHCPV6_MSG_REBIND:
909 type = "REBIND";
910 break;
911 case DHCPV6_MSG_RELEASE:
912 type = "RELEASE";
913 break;
914 case DHCPV6_MSG_DECLINE:
915 type = "DECLINE";
916 break;
917 }
918
919 switch (code) {
920 case DHCPV6_STATUS_OK:
921 status = "ok";
922 break;
923 case DHCPV6_STATUS_NOADDRSAVAIL:
924 status = "no addresses available";
925 break;
926 case DHCPV6_STATUS_NOBINDING:
927 status = "no binding";
928 break;
929 case DHCPV6_STATUS_NOTONLINK:
930 status = "not on-link";
931 break;
932 case DHCPV6_STATUS_NOPREFIXAVAIL:
933 status = "no prefix available";
934 break;
935 }
936
937 char leasebuf[256] = "";
938
939 if (a) {
940 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
941 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
942 size_t lbsize = 0;
943 size_t m = elect_addr(addrs, addrlen);
944 char addrbuf[INET6_ADDRSTRLEN];
945
946 for (size_t i = 0; i < addrlen; ++i) {
947 if (!valid_addr(&addrs[i], now))
948 continue;
949
950 struct in6_addr addr = addrs[i].addr;
951 int prefix = a->managed ? addrs[i].prefix : a->length;
952 if (prefix == 128) {
953 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
954 a->assigned == 0)
955 continue;
956
957 addr.s6_addr32[3] = htonl(a->assigned);
958 }
959 else {
960 if (!valid_prefix_length(a, addrs[i].prefix))
961 continue;
962
963 addr.s6_addr32[1] |= htonl(a->assigned);
964 }
965
966 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
967 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
968 }
969 }
970
971 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
972 duidbuf, iface->ifname, status, leasebuf);
973 }
974
975 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
976 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
977 {
978 time_t now = odhcpd_time();
979 size_t response_len = 0;
980 const struct dhcpv6_client_header *hdr = data;
981 uint8_t *start = (uint8_t*)&hdr[1], *odata;
982 uint16_t otype, olen;
983 /* Find and parse client-id and hostname */
984 bool accept_reconf = false;
985 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
986 char hostname[256];
987 size_t hostname_len = 0;
988 bool notonlink = false;
989 char duidbuf[261];
990
991 dhcpv6_for_each_option(start, end, otype, olen, odata) {
992 if (otype == DHCPV6_OPT_CLIENTID) {
993 clid_data = odata;
994 clid_len = olen;
995
996 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
997 memcpy(mac, &odata[8], sizeof(mac));
998 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
999 memcpy(mac, &odata[4], sizeof(mac));
1000
1001 if (olen <= 130)
1002 odhcpd_hexlify(duidbuf, odata, olen);
1003 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1004 uint8_t fqdn_buf[256];
1005 memcpy(fqdn_buf, odata, olen);
1006 fqdn_buf[olen++] = 0;
1007
1008 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1009 hostname_len = strcspn(hostname, ".");
1010 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1011 accept_reconf = true;
1012 }
1013
1014 if (!clid_data || !clid_len || clid_len > 130)
1015 goto out;
1016
1017 struct dhcpv6_assignment *first = NULL;
1018 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1019 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1020 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1021 bool ia_addr_present = false;
1022 if (!is_pd && !is_na)
1023 continue;
1024
1025 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1026 size_t ia_response_len = 0;
1027 uint8_t reqlen = (is_pd) ? 62 : 128;
1028 uint32_t reqhint = 0;
1029
1030 /* Parse request hint for IA-PD */
1031 if (is_pd) {
1032 uint8_t *sdata;
1033 uint16_t stype, slen;
1034 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1035 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1036 continue;
1037
1038 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1039 if (p->prefix) {
1040 reqlen = p->prefix;
1041 reqhint = ntohl(p->addr.s6_addr32[1]);
1042 if (reqlen > 32 && reqlen <= 64)
1043 reqhint &= (1U << (64 - reqlen)) - 1;
1044 }
1045 }
1046
1047 if (reqlen > 64)
1048 reqlen = 64;
1049 } else if (is_na) {
1050 uint8_t *sdata;
1051 uint16_t stype, slen;
1052 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1053 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1054 continue;
1055
1056 ia_addr_present = true;
1057 }
1058 }
1059
1060 /* Find assignment */
1061 struct dhcpv6_assignment *c, *a = NULL;
1062 list_for_each_entry(c, &iface->ia_assignments, head) {
1063 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1064 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1065 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1066 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1067 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1068 a = c;
1069
1070 /* Reset state */
1071 if (a->flags & OAF_BOUND)
1072 apply_lease(iface, a, false);
1073
1074 memcpy(a->clid_data, clid_data, clid_len);
1075 a->clid_len = clid_len;
1076 a->iaid = ia->iaid;
1077 a->peer = *addr;
1078 a->reconf_cnt = 0;
1079 a->reconf_sent = 0;
1080 break;
1081 }
1082 }
1083
1084 /* Generic message handling */
1085 uint16_t status = DHCPV6_STATUS_OK;
1086 if (a && a->managed_size < 0)
1087 return -1;
1088
1089 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1090 bool assigned = !!a;
1091
1092 if (!a && !iface->no_dynamic_dhcp) {
1093 /* Create new binding */
1094 a = calloc(1, sizeof(*a) + clid_len);
1095 if (a) {
1096 a->clid_len = clid_len;
1097 a->iaid = ia->iaid;
1098 a->length = reqlen;
1099 a->peer = *addr;
1100 a->assigned = reqhint;
1101 /* Set valid time to current time indicating */
1102 /* assignment is not having infinite lifetime */
1103 a->valid_until = now;
1104
1105 if (first)
1106 memcpy(a->key, first->key, sizeof(a->key));
1107 else
1108 odhcpd_urandom(a->key, sizeof(a->key));
1109 memcpy(a->clid_data, clid_data, clid_len);
1110
1111 if (is_pd)
1112 while (!(assigned = assign_pd(iface, a)) &&
1113 !a->managed_size && ++a->length <= 64);
1114 else
1115 assigned = assign_na(iface, a);
1116
1117 if (a->managed_size && !assigned)
1118 return -1;
1119 }
1120 }
1121
1122 if (!assigned || iface->ia_addr_len == 0)
1123 /* Set error status */
1124 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1125 else if (assigned && !first) {
1126 size_t handshake_len = 4;
1127 buf[0] = 0;
1128 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1129 buf[2] = 0;
1130 buf[3] = 0;
1131
1132 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1133 struct dhcpv6_auth_reconfigure auth = {
1134 htons(DHCPV6_OPT_AUTH),
1135 htons(sizeof(auth) - 4),
1136 3, 1, 0,
1137 {htonl(time(NULL)), htonl(++serial)},
1138 1,
1139 {0}
1140 };
1141 memcpy(auth.key, a->key, sizeof(a->key));
1142 memcpy(buf + handshake_len, &auth, sizeof(auth));
1143 handshake_len += sizeof(auth);
1144 }
1145
1146 buf += handshake_len;
1147 buflen -= handshake_len;
1148 response_len += handshake_len;
1149
1150 first = a;
1151 }
1152
1153 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1154
1155 /* Was only a solicitation: mark binding for removal */
1156 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1157 a->flags &= ~OAF_BOUND;
1158
1159 if (!(a->flags & OAF_STATIC))
1160 a->valid_until = now;
1161 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1162 if (hostname_len > 0) {
1163 a->hostname = realloc(a->hostname, hostname_len + 1);
1164 if (a->hostname) {
1165 memcpy(a->hostname, hostname, hostname_len);
1166 a->hostname[hostname_len] = 0;
1167 }
1168 }
1169 a->accept_reconf = accept_reconf;
1170 a->flags |= OAF_BOUND;
1171 apply_lease(iface, a, true);
1172 } else if (!assigned && a && a->managed_size == 0) {
1173 /* Cleanup failed assignment */
1174 free_dhcpv6_assignment(a);
1175 a = NULL;
1176 }
1177 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1178 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1179 hdr->msg_type == DHCPV6_MSG_REBIND ||
1180 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1181 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1182 status = DHCPV6_STATUS_NOBINDING;
1183 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1184 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1185 hdr->msg_type == DHCPV6_MSG_REBIND) {
1186 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1187 if (a) {
1188 a->flags |= OAF_BOUND;
1189 apply_lease(iface, a, true);
1190 }
1191 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1192 if (!(a->flags & OAF_STATIC))
1193 a->valid_until = now - 1;
1194
1195 if (a->flags & OAF_BOUND) {
1196 apply_lease(iface, a, false);
1197 a->flags &= ~OAF_BOUND;
1198 }
1199 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1200 a->flags &= ~OAF_BOUND;
1201
1202 if (!(a->flags & OAF_STATIC)) {
1203 a->clid_len = 0;
1204 a->valid_until = now + 3600; /* Block address for 1h */
1205 }
1206 }
1207 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1208 /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1209 status = DHCPV6_STATUS_NOTONLINK;
1210 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1211 notonlink = true;
1212 }
1213
1214 buf += ia_response_len;
1215 buflen -= ia_response_len;
1216 response_len += ia_response_len;
1217 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1218 }
1219
1220 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1221 response_len + 6 < buflen) {
1222 buf[0] = 0;
1223 buf[1] = DHCPV6_OPT_STATUS;
1224 buf[2] = 0;
1225 buf[3] = 2;
1226 buf[4] = 0;
1227 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1228 response_len += 6;
1229 }
1230
1231 dhcpv6_write_statefile();
1232
1233 out:
1234 return response_len;
1235 }
OpenWrt DHCP Server