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dhcpv6-ia: apply lease delete based on assignment bound state
[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 if (lease->dhcpv4_leasetime > 0)
92 a->leasetime = lease->dhcpv4_leasetime;
93
94 a->clid_len = duid_len;
95 a->length = 128;
96 if (lease->hostid) {
97 a->assigned = lease->hostid;
98 } else {
99 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
100 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
101 }
102
103 odhcpd_urandom(a->key, sizeof(a->key));
104 memcpy(a->clid_data, lease->duid, lease->duid_len);
105 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
106 /* Static assignment */
107 a->flags |= OAF_STATIC;
108 /* Infinite valid */
109 a->valid_until = 0;
110
111 /* Assign to all interfaces */
112 struct dhcpv6_assignment *c;
113 list_for_each_entry(c, &iface->ia_assignments, head) {
114 if (c->length != 128 || c->assigned > a->assigned) {
115 list_add_tail(&a->head, &c->head);
116 break;
117 } else if (c->assigned == a->assigned)
118 /* Already an assignment with that number */
119 break;
120 }
121
122 if (a->head.next) {
123 if (lease->hostname[0]) {
124 free(a->hostname);
125 a->hostname = strdup(lease->hostname);
126 }
127 } else
128 free_dhcpv6_assignment(a);
129 }
130 }
131 return 0;
132 }
133
134 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
135 {
136 if (c->managed_sock.fd.registered) {
137 ustream_free(&c->managed_sock.stream);
138 close(c->managed_sock.fd.fd);
139 }
140
141 if (c->head.next)
142 list_del(&c->head);
143
144 free(c->managed);
145 free(c->hostname);
146 free(c);
147 }
148
149 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
150 {
151 return (a->managed_size || a->length > prefix_length);
152 }
153
154 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
155 {
156 return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
157 }
158
159 static size_t elect_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
160 {
161 size_t i, m;
162
163 for (i = 0, m = 0; i < addrlen; ++i) {
164 if (addrs[i].preferred > addrs[m].preferred ||
165 (addrs[i].preferred == addrs[m].preferred &&
166 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
167 m = i;
168 }
169
170 return m;
171 }
172
173 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
174 {
175 struct {
176 struct dhcpv6_client_header hdr;
177 uint16_t srvid_type;
178 uint16_t srvid_len;
179 uint16_t duid_type;
180 uint16_t hardware_type;
181 uint8_t mac[6];
182 uint16_t msg_type;
183 uint16_t msg_len;
184 uint8_t msg_id;
185 struct dhcpv6_auth_reconfigure auth;
186 uint16_t clid_type;
187 uint16_t clid_len;
188 uint8_t clid_data[128];
189 } __attribute__((packed)) reconf_msg = {
190 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
191 .srvid_type = htons(DHCPV6_OPT_SERVERID),
192 .srvid_len = htons(10),
193 .duid_type = htons(3),
194 .hardware_type = htons(1),
195 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
196 .msg_len = htons(1),
197 .msg_id = DHCPV6_MSG_RENEW,
198 .auth = {htons(DHCPV6_OPT_AUTH),
199 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
200 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
201 .clid_type = htons(DHCPV6_OPT_CLIENTID),
202 .clid_len = htons(assign->clid_len),
203 .clid_data = {0},
204 };
205
206 odhcpd_get_mac(iface, reconf_msg.mac);
207 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
208 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
209
210 md5_ctx_t md5;
211 uint8_t secretbytes[64];
212 memset(secretbytes, 0, sizeof(secretbytes));
213 memcpy(secretbytes, assign->key, sizeof(assign->key));
214
215 for (size_t i = 0; i < sizeof(secretbytes); ++i)
216 secretbytes[i] ^= 0x36;
217
218 md5_begin(&md5);
219 md5_hash(secretbytes, sizeof(secretbytes), &md5);
220 md5_hash(iov.iov_base, iov.iov_len, &md5);
221 md5_end(reconf_msg.auth.key, &md5);
222
223 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
224 secretbytes[i] ^= 0x36;
225 secretbytes[i] ^= 0x5c;
226 }
227
228 md5_begin(&md5);
229 md5_hash(secretbytes, sizeof(secretbytes), &md5);
230 md5_hash(reconf_msg.auth.key, 16, &md5);
231 md5_end(reconf_msg.auth.key, &md5);
232
233 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
234 }
235
236 void dhcpv6_write_statefile(void)
237 {
238 md5_ctx_t md5;
239 md5_begin(&md5);
240
241 if (config.dhcp_statefile) {
242 time_t now = odhcpd_time(), wall_time = time(NULL);
243 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
244 if (fd < 0)
245 return;
246
247 lockf(fd, F_LOCK, 0);
248 if (ftruncate(fd, 0) < 0) {}
249
250 FILE *fp = fdopen(fd, "w");
251 if (!fp) {
252 close(fd);
253 return;
254 }
255
256 struct interface *iface;
257 list_for_each_entry(iface, &interfaces, head) {
258 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
259 continue;
260
261 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
262 struct dhcpv6_assignment *c;
263 list_for_each_entry(c, &iface->ia_assignments, head) {
264 if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
265 continue;
266
267 char ipbuf[INET6_ADDRSTRLEN];
268 char leasebuf[512];
269 char duidbuf[264];
270 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
271
272 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
273 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
274 iface->ifname, duidbuf, ntohl(c->iaid),
275 (c->hostname ? c->hostname : "-"),
276 (c->valid_until > now ?
277 (c->valid_until - now + wall_time) :
278 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
279 c->assigned, (unsigned)c->length);
280
281 struct in6_addr addr;
282 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
283 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
284 size_t m = elect_addr(addrs, addrlen);
285
286 for (size_t i = 0; i < addrlen; ++i) {
287 if (!valid_addr(&addrs[i], now) ||
288 (!INFINITE_VALID(c->valid_until) && c->valid_until <= now))
289 continue;
290
291 addr = addrs[i].addr;
292 if (c->length == 128) {
293 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
294 continue;
295
296 addr.s6_addr32[3] = htonl(c->assigned);
297 }
298 else {
299 if (!valid_prefix_length(c, addrs[i].prefix))
300 continue;
301
302 addr.s6_addr32[1] |= htonl(c->assigned);
303 }
304
305 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
306
307 if (c->length == 128 && c->hostname) {
308 fputs(ipbuf, fp);
309
310 char b[256];
311 if (dn_expand(iface->search, iface->search + iface->search_len,
312 iface->search, b, sizeof(b)) > 0)
313 fprintf(fp, "\t%s.%s", c->hostname, b);
314
315 fprintf(fp, "\t%s\n", c->hostname);
316 md5_hash(ipbuf, strlen(ipbuf), &md5);
317 md5_hash(c->hostname, strlen(c->hostname), &md5);
318 }
319
320 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
321 (c->managed_size) ? addrs[i].prefix : c->length);
322 }
323 leasebuf[l - 1] = '\n';
324 fwrite(leasebuf, 1, l, fp);
325 }
326 }
327
328 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
329 struct dhcpv4_assignment *c;
330 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
331 if (!(c->flags & OAF_BOUND))
332 continue;
333
334 char ipbuf[INET6_ADDRSTRLEN];
335 char leasebuf[512];
336 char duidbuf[16];
337 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
338
339 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
340 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
341 iface->ifname, duidbuf,
342 (c->hostname ? c->hostname : "-"),
343 (c->valid_until > now ?
344 (c->valid_until - now + wall_time) :
345 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
346 c->addr);
347
348 struct in_addr addr = {htonl(c->addr)};
349 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
350
351 if (c->hostname) {
352 fputs(ipbuf, fp);
353
354 char b[256];
355 if (dn_expand(iface->search, iface->search + iface->search_len,
356 iface->search, b, sizeof(b)) > 0)
357 fprintf(fp, "\t%s.%s", c->hostname, b);
358
359 fprintf(fp, "\t%s\n", c->hostname);
360 md5_hash(ipbuf, strlen(ipbuf), &md5);
361 md5_hash(c->hostname, strlen(c->hostname), &md5);
362 }
363
364 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
365 leasebuf[l - 1] = '\n';
366 fwrite(leasebuf, 1, l, fp);
367 }
368 }
369 }
370
371 fclose(fp);
372 }
373
374 uint8_t newmd5[16];
375 md5_end(newmd5, &md5);
376
377 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
378 memcpy(statemd5, newmd5, sizeof(statemd5));
379 char *argv[2] = {config.dhcp_cb, NULL};
380 if (!vfork()) {
381 execv(argv[0], argv);
382 _exit(128);
383 }
384 }
385 }
386
387
388 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
389 {
390 if (a->length > 64 || a->managed_size < 0)
391 return;
392
393 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
394 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
395
396 for (size_t i = 0; i < addrlen; ++i) {
397 struct in6_addr prefix = addrs[i].addr;
398 prefix.s6_addr32[1] |= htonl(a->assigned);
399 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
400 iface, &a->peer.sin6_addr, 1024, add);
401 }
402 }
403
404 /* More data was received from TCP connection */
405 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
406 {
407 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
408 time_t now = odhcpd_time();
409 bool first = c->managed_size < 0;
410
411 for (;;) {
412 int pending;
413 char *data = ustream_get_read_buf(s, &pending);
414 char *end = memmem(data, pending, "\n\n", 2);
415
416 if (!end)
417 break;
418
419 end += 2;
420 end[-1] = 0;
421
422 c->managed_size = 0;
423 if (c->accept_reconf)
424 c->reconf_cnt = 1;
425
426 char *saveptr;
427 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
428 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
429 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
430
431 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
432 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
433 continue;
434
435 x = strtok_r(NULL, ",", &saveptr2);
436 if (sscanf(x, "%hhu", &n->prefix) < 1)
437 continue;
438
439 x = strtok_r(NULL, ",", &saveptr2);
440 if (sscanf(x, "%u", &n->preferred) < 1)
441 continue;
442
443 x = strtok_r(NULL, ",", &saveptr2);
444 if (sscanf(x, "%u", &n->valid) < 1)
445 continue;
446
447 if (n->preferred > n->valid)
448 continue;
449
450 if (UINT32_MAX - now < n->preferred)
451 n->preferred = UINT32_MAX;
452 else
453 n->preferred += now;
454
455 if (UINT32_MAX - now < n->valid)
456 n->valid = UINT32_MAX;
457 else
458 n->valid += now;
459
460 n->dprefix = 0;
461
462 ++c->managed_size;
463 }
464
465 ustream_consume(s, end - data);
466 }
467
468 if (first && c->managed_size == 0)
469 free_dhcpv6_assignment(c);
470 else if (first && !(c->flags & OAF_STATIC))
471 c->valid_until = now + 150;
472 }
473
474
475 /* TCP transmission has ended, either because of success or timeout or other error */
476 static void managed_handle_pd_done(struct ustream *s)
477 {
478 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
479
480 if (!(c->flags & OAF_STATIC))
481 c->valid_until = odhcpd_time() + 15;
482
483 c->managed_size = 0;
484
485 if (c->accept_reconf)
486 c->reconf_cnt = 1;
487 }
488
489 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
490 {
491 struct dhcpv6_assignment *c;
492
493 if (iface->dhcpv6_pd_manager[0]) {
494 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
495 if (fd >= 0) {
496 char iaidbuf[298];
497 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
498
499 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
500 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
501 ustream_fd_init(&assign->managed_sock, fd);
502 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
503 iaidbuf, assign->iaid, assign->length);
504 ustream_write_pending(&assign->managed_sock.stream);
505 assign->managed_size = -1;
506
507 if (!(assign->flags & OAF_STATIC))
508 assign->valid_until = odhcpd_time() + 15;
509
510 list_add(&assign->head, &iface->ia_assignments);
511
512 /* Wait initial period of up to 250ms for immediate assignment */
513 struct pollfd pfd = { .fd = fd, .events = POLLIN };
514 poll(&pfd, 1, 250);
515 managed_handle_pd_data(&assign->managed_sock.stream, 0);
516
517 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
518 return true;
519 }
520
521 return false;
522 } else if (iface->ia_addr_len < 1)
523 return false;
524
525 /* Try honoring the hint first */
526 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
527 if (assign->assigned) {
528 list_for_each_entry(c, &iface->ia_assignments, head) {
529 if (c->length == 128 || c->length == 0)
530 continue;
531
532 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
533 list_add_tail(&assign->head, &c->head);
534
535 if (assign->flags & OAF_BOUND)
536 apply_lease(iface, assign, true);
537
538 return true;
539 }
540
541 if (c->assigned != 0)
542 current = (c->assigned + (1 << (64 - c->length)));
543 }
544 }
545
546 /* Fallback to a variable assignment */
547 current = 1;
548 list_for_each_entry(c, &iface->ia_assignments, head) {
549 if (c->length == 128 || c->length == 0)
550 continue;
551
552 current = (current + asize) & (~asize);
553 if (current + asize < c->assigned) {
554 assign->assigned = current;
555 list_add_tail(&assign->head, &c->head);
556
557 if (assign->flags & OAF_BOUND)
558 apply_lease(iface, assign, true);
559
560 return true;
561 }
562
563 if (c->assigned != 0)
564 current = (c->assigned + (1 << (64 - c->length)));
565 }
566
567 return false;
568 }
569
570 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
571 {
572 /* Seed RNG with checksum of DUID */
573 uint32_t seed = 0;
574 for (size_t i = 0; i < assign->clid_len; ++i)
575 seed += assign->clid_data[i];
576 srand(seed);
577
578 /* Try to assign up to 100x */
579 for (size_t i = 0; i < 100; ++i) {
580 uint32_t try;
581 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
582
583 struct dhcpv6_assignment *c;
584 list_for_each_entry(c, &iface->ia_assignments, head) {
585 if (c->length == 0)
586 continue;
587
588 if (c->assigned > try || c->length != 128) {
589 assign->assigned = try;
590 list_add_tail(&assign->head, &c->head);
591 return true;
592 } else if (c->assigned == try)
593 break;
594 }
595 }
596
597 return false;
598 }
599
600 void dhcpv6_ia_preupdate(struct interface *iface)
601 {
602 if (iface->dhcpv6 != RELAYD_SERVER)
603 return;
604
605 struct dhcpv6_assignment *c, *border = list_last_entry(
606 &iface->ia_assignments, struct dhcpv6_assignment, head);
607
608 list_for_each_entry(c, &iface->ia_assignments, head)
609 if (c != border && !iface->managed && (c->flags & OAF_BOUND))
610 apply_lease(iface, c, false);
611 }
612
613 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
614 {
615 if (iface->dhcpv6 != RELAYD_SERVER)
616 return;
617
618 int minprefix = -1;
619 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
620 if (iface->ia_addr[i].preferred > (uint32_t)now &&
621 iface->ia_addr[i].prefix < 64 &&
622 iface->ia_addr[i].prefix > minprefix)
623 minprefix = iface->ia_addr[i].prefix;
624 }
625
626 struct dhcpv6_assignment *border = list_last_entry(
627 &iface->ia_assignments, struct dhcpv6_assignment, head);
628
629 if (minprefix > 32 && minprefix <= 64)
630 border->assigned = 1U << (64 - minprefix);
631 else
632 border->assigned = 0;
633
634 struct list_head reassign = LIST_HEAD_INIT(reassign);
635 struct dhcpv6_assignment *c, *d;
636 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
637 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
638 c->managed_size)
639 continue;
640
641 if (c->length < 128 && c->assigned >= border->assigned && c != border)
642 list_move(&c->head, &reassign);
643 else if (c != border && (c->flags & OAF_BOUND))
644 apply_lease(iface, c, true);
645
646 if (c->accept_reconf && c->reconf_cnt == 0) {
647 c->reconf_cnt = 1;
648 c->reconf_sent = now;
649 send_reconf(iface, c);
650
651 /* Leave all other assignments of that client alone */
652 struct dhcpv6_assignment *a;
653 list_for_each_entry(a, &iface->ia_assignments, head)
654 if (a != c && a->clid_len == c->clid_len &&
655 !memcmp(a->clid_data, c->clid_data, a->clid_len))
656 c->reconf_cnt = INT_MAX;
657 }
658 }
659
660 while (!list_empty(&reassign)) {
661 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
662 list_del(&c->head);
663 if (!assign_pd(iface, c)) {
664 c->assigned = 0;
665 list_add(&c->head, &iface->ia_assignments);
666 }
667 }
668
669 dhcpv6_write_statefile();
670 }
671
672 static void reconf_timer(struct uloop_timeout *event)
673 {
674 time_t now = odhcpd_time();
675 struct interface *iface;
676 list_for_each_entry(iface, &interfaces, head) {
677 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
678 continue;
679
680 struct dhcpv6_assignment *a, *n;
681 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
682 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
683 if ((a->length < 128 && a->clid_len > 0) ||
684 (a->length == 128 && a->clid_len == 0))
685 free_dhcpv6_assignment(a);
686
687 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
688 now > a->reconf_sent + (1 << a->reconf_cnt)) {
689 ++a->reconf_cnt;
690 a->reconf_sent = now;
691 send_reconf(iface, a);
692 }
693 }
694 }
695 uloop_timeout_set(event, 2000);
696 }
697
698 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
699 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
700 struct interface *iface, bool request)
701 {
702 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
703 return 0;
704
705 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
706 size_t datalen = sizeof(out);
707 time_t now = odhcpd_time();
708
709 if (status) {
710 struct __attribute__((packed)) {
711 uint16_t type;
712 uint16_t len;
713 uint16_t value;
714 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
715 htons(status)};
716
717 memcpy(buf + datalen, &stat, sizeof(stat));
718 datalen += sizeof(stat);
719 } else {
720 if (a) {
721 uint32_t leasetime;
722 if (a->leasetime > 0)
723 leasetime = a->leasetime;
724 else
725 leasetime = iface->dhcpv4_leasetime;
726
727 if (leasetime == 0)
728 leasetime = 3600;
729 else if (leasetime < 60)
730 leasetime = 60;
731
732 uint32_t pref = leasetime;
733 uint32_t valid = leasetime;
734
735 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
736 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
737 size_t m = elect_addr(addrs, addrlen);
738
739 for (size_t i = 0; i < addrlen; ++i) {
740 uint32_t prefix_pref = addrs[i].preferred;
741 uint32_t prefix_valid = addrs[i].valid;
742
743 if (!valid_addr(&addrs[i], now))
744 continue;
745
746 if (prefix_pref != UINT32_MAX)
747 prefix_pref -= now;
748
749 if (prefix_valid != UINT32_MAX)
750 prefix_valid -= now;
751
752 if (a->length < 128) {
753 struct dhcpv6_ia_prefix p = {
754 .type = htons(DHCPV6_OPT_IA_PREFIX),
755 .len = htons(sizeof(p) - 4),
756 .preferred = htonl(prefix_pref),
757 .valid = htonl(prefix_valid),
758 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
759 .addr = addrs[i].addr
760 };
761 p.addr.s6_addr32[1] |= htonl(a->assigned);
762
763 size_t entrlen = sizeof(p) - 4;
764
765 if (datalen + entrlen + 4 > buflen ||
766 (a->assigned == 0 && a->managed_size == 0) ||
767 !valid_prefix_length(a, addrs[i].prefix))
768 continue;
769
770 memcpy(buf + datalen, &p, sizeof(p));
771 datalen += entrlen + 4;
772 } else {
773 struct dhcpv6_ia_addr n = {
774 .type = htons(DHCPV6_OPT_IA_ADDR),
775 .len = htons(sizeof(n) - 4),
776 .addr = addrs[i].addr,
777 .preferred = htonl(prefix_pref),
778 .valid = htonl(prefix_valid)
779 };
780 n.addr.s6_addr32[3] = htonl(a->assigned);
781 size_t entrlen = sizeof(n) - 4;
782
783 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
784 a->assigned == 0 ||
785 datalen + entrlen + 4 > buflen)
786 continue;
787
788 memcpy(buf + datalen, &n, sizeof(n));
789 datalen += entrlen + 4;
790 }
791
792 /* Calculate T1 / T2 based on non-deprecated addresses */
793 if (prefix_pref > 0) {
794 if (prefix_pref < pref)
795 pref = prefix_pref;
796
797 if (prefix_valid < valid)
798 valid = prefix_valid;
799 }
800 }
801
802 if (!INFINITE_VALID(a->valid_until))
803 /* UINT32_MAX is considered as infinite leasetime */
804 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
805
806 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
807 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
808
809 if (!out.t1)
810 out.t1 = htonl(1);
811
812 if (!out.t2)
813 out.t2 = htonl(1);
814 }
815
816 if (!request) {
817 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
818 uint16_t otype, olen;
819 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
820 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
821 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
822 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
823 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
824 continue;
825
826 bool found = false;
827 if (a) {
828 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
829 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
830
831 for (size_t i = 0; i < addrlen; ++i) {
832 if (!valid_addr(&addrs[i], now))
833 continue;
834
835 struct in6_addr addr = addrs[i].addr;
836 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
837 addr.s6_addr32[1] |= htonl(a->assigned);
838
839 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
840 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
841 found = true;
842 } else {
843 addr.s6_addr32[3] = htonl(a->assigned);
844
845 if (!memcmp(&n->addr, &addr, sizeof(addr)))
846 found = true;
847 }
848 }
849 }
850
851 if (!found) {
852 if (otype == DHCPV6_OPT_IA_PREFIX) {
853 struct dhcpv6_ia_prefix inv = {
854 .type = htons(DHCPV6_OPT_IA_PREFIX),
855 .len = htons(sizeof(inv) - 4),
856 .preferred = 0,
857 .valid = 0,
858 .prefix = p->prefix,
859 .addr = p->addr
860 };
861
862 if (datalen + sizeof(inv) > buflen)
863 continue;
864
865 memcpy(buf + datalen, &inv, sizeof(inv));
866 datalen += sizeof(inv);
867 } else {
868 struct dhcpv6_ia_addr inv = {
869 .type = htons(DHCPV6_OPT_IA_ADDR),
870 .len = htons(sizeof(inv) - 4),
871 .addr = n->addr,
872 .preferred = 0,
873 .valid = 0
874 };
875
876 if (datalen + sizeof(inv) > buflen)
877 continue;
878
879 memcpy(buf + datalen, &inv, sizeof(inv));
880 datalen += sizeof(inv);
881 }
882 }
883 }
884 }
885 }
886
887 out.len = htons(datalen - 4);
888 memcpy(buf, &out, sizeof(out));
889 return datalen;
890 }
891
892 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
893 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
894 {
895 const char *type = "UNKNOWN";
896 const char *status = "UNKNOWN";
897
898 if (msgtype == DHCPV6_MSG_RENEW)
899 return;
900
901 switch (msgtype) {
902 case DHCPV6_MSG_SOLICIT:
903 type = "SOLICIT";
904 break;
905 case DHCPV6_MSG_REQUEST:
906 type = "REQUEST";
907 break;
908 case DHCPV6_MSG_CONFIRM:
909 type = "CONFIRM";
910 break;
911 case DHCPV6_MSG_RENEW:
912 type = "RENEW";
913 break;
914 case DHCPV6_MSG_REBIND:
915 type = "REBIND";
916 break;
917 case DHCPV6_MSG_RELEASE:
918 type = "RELEASE";
919 break;
920 case DHCPV6_MSG_DECLINE:
921 type = "DECLINE";
922 break;
923 }
924
925 switch (code) {
926 case DHCPV6_STATUS_OK:
927 status = "ok";
928 break;
929 case DHCPV6_STATUS_NOADDRSAVAIL:
930 status = "no addresses available";
931 break;
932 case DHCPV6_STATUS_NOBINDING:
933 status = "no binding";
934 break;
935 case DHCPV6_STATUS_NOTONLINK:
936 status = "not on-link";
937 break;
938 case DHCPV6_STATUS_NOPREFIXAVAIL:
939 status = "no prefix available";
940 break;
941 }
942
943 char leasebuf[256] = "";
944
945 if (a) {
946 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
947 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
948 size_t lbsize = 0;
949 size_t m = elect_addr(addrs, addrlen);
950 char addrbuf[INET6_ADDRSTRLEN];
951
952 for (size_t i = 0; i < addrlen; ++i) {
953 if (!valid_addr(&addrs[i], now))
954 continue;
955
956 struct in6_addr addr = addrs[i].addr;
957 int prefix = a->managed ? addrs[i].prefix : a->length;
958 if (prefix == 128) {
959 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
960 a->assigned == 0)
961 continue;
962
963 addr.s6_addr32[3] = htonl(a->assigned);
964 }
965 else {
966 if (!valid_prefix_length(a, addrs[i].prefix))
967 continue;
968
969 addr.s6_addr32[1] |= htonl(a->assigned);
970 }
971
972 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
973 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
974 }
975 }
976
977 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
978 duidbuf, iface->ifname, status, leasebuf);
979 }
980
981 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
982 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
983 {
984 time_t now = odhcpd_time();
985 size_t response_len = 0;
986 const struct dhcpv6_client_header *hdr = data;
987 uint8_t *start = (uint8_t*)&hdr[1], *odata;
988 uint16_t otype, olen;
989 /* Find and parse client-id and hostname */
990 bool accept_reconf = false;
991 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
992 char hostname[256];
993 size_t hostname_len = 0;
994 bool notonlink = false;
995 char duidbuf[261];
996
997 dhcpv6_for_each_option(start, end, otype, olen, odata) {
998 if (otype == DHCPV6_OPT_CLIENTID) {
999 clid_data = odata;
1000 clid_len = olen;
1001
1002 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1003 memcpy(mac, &odata[8], sizeof(mac));
1004 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1005 memcpy(mac, &odata[4], sizeof(mac));
1006
1007 if (olen <= 130)
1008 odhcpd_hexlify(duidbuf, odata, olen);
1009 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1010 uint8_t fqdn_buf[256];
1011 memcpy(fqdn_buf, odata, olen);
1012 fqdn_buf[olen++] = 0;
1013
1014 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1015 hostname_len = strcspn(hostname, ".");
1016 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1017 accept_reconf = true;
1018 }
1019
1020 if (!clid_data || !clid_len || clid_len > 130)
1021 goto out;
1022
1023 struct dhcpv6_assignment *first = NULL;
1024 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1025 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1026 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1027 bool ia_addr_present = false;
1028 if (!is_pd && !is_na)
1029 continue;
1030
1031 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1032 size_t ia_response_len = 0;
1033 uint8_t reqlen = (is_pd) ? 62 : 128;
1034 uint32_t reqhint = 0;
1035
1036 /* Parse request hint for IA-PD */
1037 if (is_pd) {
1038 uint8_t *sdata;
1039 uint16_t stype, slen;
1040 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1041 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1042 continue;
1043
1044 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1045 if (p->prefix) {
1046 reqlen = p->prefix;
1047 reqhint = ntohl(p->addr.s6_addr32[1]);
1048 if (reqlen > 32 && reqlen <= 64)
1049 reqhint &= (1U << (64 - reqlen)) - 1;
1050 }
1051 }
1052
1053 if (reqlen > 64)
1054 reqlen = 64;
1055 } else if (is_na) {
1056 uint8_t *sdata;
1057 uint16_t stype, slen;
1058 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1059 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1060 continue;
1061
1062 ia_addr_present = true;
1063 }
1064 }
1065
1066 /* Find assignment */
1067 struct dhcpv6_assignment *c, *a = NULL;
1068 list_for_each_entry(c, &iface->ia_assignments, head) {
1069 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1070 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1071 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1072 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1073 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1074 a = c;
1075
1076 /* Reset state */
1077 if (a->flags & OAF_BOUND)
1078 apply_lease(iface, a, false);
1079
1080 memcpy(a->clid_data, clid_data, clid_len);
1081 a->clid_len = clid_len;
1082 a->iaid = ia->iaid;
1083 a->peer = *addr;
1084 a->reconf_cnt = 0;
1085 a->reconf_sent = 0;
1086 break;
1087 }
1088 }
1089
1090 /* Generic message handling */
1091 uint16_t status = DHCPV6_STATUS_OK;
1092 if (a && a->managed_size < 0)
1093 return -1;
1094
1095 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1096 bool assigned = !!a;
1097
1098 if (!a && !iface->no_dynamic_dhcp) {
1099 /* Create new binding */
1100 a = calloc(1, sizeof(*a) + clid_len);
1101 if (a) {
1102 a->clid_len = clid_len;
1103 a->iaid = ia->iaid;
1104 a->length = reqlen;
1105 a->peer = *addr;
1106 a->assigned = reqhint;
1107 /* Set valid time to current time indicating */
1108 /* assignment is not having infinite lifetime */
1109 a->valid_until = now;
1110
1111 if (first)
1112 memcpy(a->key, first->key, sizeof(a->key));
1113 else
1114 odhcpd_urandom(a->key, sizeof(a->key));
1115 memcpy(a->clid_data, clid_data, clid_len);
1116
1117 if (is_pd)
1118 while (!(assigned = assign_pd(iface, a)) &&
1119 !a->managed_size && ++a->length <= 64);
1120 else
1121 assigned = assign_na(iface, a);
1122
1123 if (a->managed_size && !assigned)
1124 return -1;
1125 }
1126 }
1127
1128 if (!assigned || iface->ia_addr_len == 0)
1129 /* Set error status */
1130 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1131 else if (assigned && !first) {
1132 size_t handshake_len = 4;
1133 buf[0] = 0;
1134 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1135 buf[2] = 0;
1136 buf[3] = 0;
1137
1138 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1139 struct dhcpv6_auth_reconfigure auth = {
1140 htons(DHCPV6_OPT_AUTH),
1141 htons(sizeof(auth) - 4),
1142 3, 1, 0,
1143 {htonl(time(NULL)), htonl(++serial)},
1144 1,
1145 {0}
1146 };
1147 memcpy(auth.key, a->key, sizeof(a->key));
1148 memcpy(buf + handshake_len, &auth, sizeof(auth));
1149 handshake_len += sizeof(auth);
1150 }
1151
1152 buf += handshake_len;
1153 buflen -= handshake_len;
1154 response_len += handshake_len;
1155
1156 first = a;
1157 }
1158
1159 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1160
1161 /* Was only a solicitation: mark binding for removal */
1162 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1163 a->flags &= ~OAF_BOUND;
1164
1165 if (!(a->flags & OAF_STATIC))
1166 a->valid_until = now;
1167 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1168 if (hostname_len > 0) {
1169 a->hostname = realloc(a->hostname, hostname_len + 1);
1170 if (a->hostname) {
1171 memcpy(a->hostname, hostname, hostname_len);
1172 a->hostname[hostname_len] = 0;
1173 }
1174 }
1175 a->accept_reconf = accept_reconf;
1176 a->flags |= OAF_BOUND;
1177 apply_lease(iface, a, true);
1178 } else if (!assigned && a && a->managed_size == 0) {
1179 /* Cleanup failed assignment */
1180 free_dhcpv6_assignment(a);
1181 a = NULL;
1182 }
1183 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1184 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1185 hdr->msg_type == DHCPV6_MSG_REBIND ||
1186 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1187 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1188 status = DHCPV6_STATUS_NOBINDING;
1189 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1190 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1191 hdr->msg_type == DHCPV6_MSG_REBIND) {
1192 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1193 if (a) {
1194 a->flags |= OAF_BOUND;
1195 apply_lease(iface, a, true);
1196 }
1197 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1198 if (!(a->flags & OAF_STATIC))
1199 a->valid_until = now - 1;
1200
1201 if (a->flags & OAF_BOUND) {
1202 apply_lease(iface, a, false);
1203 a->flags &= ~OAF_BOUND;
1204 }
1205 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1206 a->flags &= ~OAF_BOUND;
1207
1208 if (!(a->flags & OAF_STATIC)) {
1209 a->clid_len = 0;
1210 a->valid_until = now + 3600; /* Block address for 1h */
1211 }
1212 }
1213 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1214 /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1215 status = DHCPV6_STATUS_NOTONLINK;
1216 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1217 notonlink = true;
1218 }
1219
1220 buf += ia_response_len;
1221 buflen -= ia_response_len;
1222 response_len += ia_response_len;
1223 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1224 }
1225
1226 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1227 response_len + 6 < buflen) {
1228 buf[0] = 0;
1229 buf[1] = DHCPV6_OPT_STATUS;
1230 buf[2] = 0;
1231 buf[3] = 2;
1232 buf[4] = 0;
1233 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1234 response_len += 6;
1235 }
1236
1237 dhcpv6_write_statefile();
1238
1239 out:
1240 return response_len;
1241 }
OpenWrt DHCP Server