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[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 int ret;
246 ret = lockf(fd, F_LOCK, 0);
247 if (ret < 0) {
248 close(fd);
249 return;
250 }
251 if (ftruncate(fd, 0) < 0) {}
252
253 FILE *fp = fdopen(fd, "w");
254 if (!fp) {
255 close(fd);
256 return;
257 }
258
259 struct interface *iface;
260 list_for_each_entry(iface, &interfaces, head) {
261 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
262 continue;
263
264 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
265 struct dhcpv6_assignment *c;
266 list_for_each_entry(c, &iface->ia_assignments, head) {
267 if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
268 continue;
269
270 char ipbuf[INET6_ADDRSTRLEN];
271 char leasebuf[512];
272 char duidbuf[264];
273 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
274
275 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
276 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
277 iface->ifname, duidbuf, ntohl(c->iaid),
278 (c->hostname ? c->hostname : "-"),
279 (c->valid_until > now ?
280 (c->valid_until - now + wall_time) :
281 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
282 c->assigned, (unsigned)c->length);
283
284 struct in6_addr addr;
285 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
286 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
287 size_t m = elect_addr(addrs, addrlen);
288
289 for (size_t i = 0; i < addrlen; ++i) {
290 if (!valid_addr(&addrs[i], now) ||
291 (!INFINITE_VALID(c->valid_until) && c->valid_until <= now))
292 continue;
293
294 addr = addrs[i].addr;
295 if (c->length == 128) {
296 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
297 continue;
298
299 addr.s6_addr32[3] = htonl(c->assigned);
300 } else {
301 if (!valid_prefix_length(c, addrs[i].prefix))
302 continue;
303
304 addr.s6_addr32[1] |= htonl(c->assigned);
305 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
306 }
307
308 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
309
310 if (c->length == 128 && c->hostname) {
311 fputs(ipbuf, fp);
312
313 char b[256];
314 if (dn_expand(iface->search, iface->search + iface->search_len,
315 iface->search, b, sizeof(b)) > 0)
316 fprintf(fp, "\t%s.%s", c->hostname, b);
317
318 fprintf(fp, "\t%s\n", c->hostname);
319 md5_hash(ipbuf, strlen(ipbuf), &md5);
320 md5_hash(c->hostname, strlen(c->hostname), &md5);
321 }
322
323 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
324 (c->managed_size) ? addrs[i].prefix : c->length);
325 }
326 leasebuf[l - 1] = '\n';
327 fwrite(leasebuf, 1, l, fp);
328 }
329 }
330
331 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
332 struct dhcpv4_assignment *c;
333 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
334 if (!(c->flags & OAF_BOUND))
335 continue;
336
337 char ipbuf[INET6_ADDRSTRLEN];
338 char leasebuf[512];
339 char duidbuf[16];
340 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
341
342 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
343 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
344 iface->ifname, duidbuf,
345 (c->hostname ? c->hostname : "-"),
346 (c->valid_until > now ?
347 (c->valid_until - now + wall_time) :
348 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
349 c->addr);
350
351 struct in_addr addr = {htonl(c->addr)};
352 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
353
354 if (c->hostname) {
355 fputs(ipbuf, fp);
356
357 char b[256];
358 if (dn_expand(iface->search, iface->search + iface->search_len,
359 iface->search, b, sizeof(b)) > 0)
360 fprintf(fp, "\t%s.%s", c->hostname, b);
361
362 fprintf(fp, "\t%s\n", c->hostname);
363 md5_hash(ipbuf, strlen(ipbuf), &md5);
364 md5_hash(c->hostname, strlen(c->hostname), &md5);
365 }
366
367 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
368 leasebuf[l - 1] = '\n';
369 fwrite(leasebuf, 1, l, fp);
370 }
371 }
372 }
373
374 fclose(fp);
375 }
376
377 uint8_t newmd5[16];
378 md5_end(newmd5, &md5);
379
380 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
381 memcpy(statemd5, newmd5, sizeof(statemd5));
382 char *argv[2] = {config.dhcp_cb, NULL};
383 if (!vfork()) {
384 execv(argv[0], argv);
385 _exit(128);
386 }
387 }
388 }
389
390
391 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
392 {
393 if (a->length > 64 || a->managed_size < 0)
394 return;
395
396 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
397 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
398
399 for (size_t i = 0; i < addrlen; ++i) {
400 struct in6_addr prefix = addrs[i].addr;
401 prefix.s6_addr32[1] |= htonl(a->assigned);
402 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
403 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
404 iface, &a->peer.sin6_addr, 1024, add);
405 }
406 }
407
408 /* More data was received from TCP connection */
409 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
410 {
411 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
412 time_t now = odhcpd_time();
413 bool first = c->managed_size < 0;
414
415 for (;;) {
416 int pending;
417 char *data = ustream_get_read_buf(s, &pending);
418 char *end = memmem(data, pending, "\n\n", 2);
419
420 if (!end)
421 break;
422
423 end += 2;
424 end[-1] = 0;
425
426 c->managed_size = 0;
427 if (c->accept_reconf)
428 c->reconf_cnt = 1;
429
430 char *saveptr;
431 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
432 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
433 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
434
435 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
436 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
437 continue;
438
439 x = strtok_r(NULL, ",", &saveptr2);
440 if (sscanf(x, "%hhu", &n->prefix) < 1)
441 continue;
442
443 x = strtok_r(NULL, ",", &saveptr2);
444 if (sscanf(x, "%u", &n->preferred) < 1)
445 continue;
446
447 x = strtok_r(NULL, ",", &saveptr2);
448 if (sscanf(x, "%u", &n->valid) < 1)
449 continue;
450
451 if (n->preferred > n->valid)
452 continue;
453
454 if (UINT32_MAX - now < n->preferred)
455 n->preferred = UINT32_MAX;
456 else
457 n->preferred += now;
458
459 if (UINT32_MAX - now < n->valid)
460 n->valid = UINT32_MAX;
461 else
462 n->valid += now;
463
464 n->dprefix = 0;
465
466 ++c->managed_size;
467 }
468
469 ustream_consume(s, end - data);
470 }
471
472 if (first && c->managed_size == 0)
473 free_dhcpv6_assignment(c);
474 else if (first && !(c->flags & OAF_STATIC))
475 c->valid_until = now + 150;
476 }
477
478
479 /* TCP transmission has ended, either because of success or timeout or other error */
480 static void managed_handle_pd_done(struct ustream *s)
481 {
482 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
483
484 if (!(c->flags & OAF_STATIC))
485 c->valid_until = odhcpd_time() + 15;
486
487 c->managed_size = 0;
488
489 if (c->accept_reconf)
490 c->reconf_cnt = 1;
491 }
492
493 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
494 {
495 struct dhcpv6_assignment *c;
496
497 if (iface->dhcpv6_pd_manager[0]) {
498 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
499 if (fd >= 0) {
500 char iaidbuf[298];
501 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
502
503 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
504 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
505 ustream_fd_init(&assign->managed_sock, fd);
506 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
507 iaidbuf, assign->iaid, assign->length);
508 ustream_write_pending(&assign->managed_sock.stream);
509 assign->managed_size = -1;
510
511 if (!(assign->flags & OAF_STATIC))
512 assign->valid_until = odhcpd_time() + 15;
513
514 list_add(&assign->head, &iface->ia_assignments);
515
516 /* Wait initial period of up to 250ms for immediate assignment */
517 struct pollfd pfd = { .fd = fd, .events = POLLIN };
518 poll(&pfd, 1, 250);
519 managed_handle_pd_data(&assign->managed_sock.stream, 0);
520
521 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
522 return true;
523 }
524
525 return false;
526 } else if (iface->ia_addr_len < 1)
527 return false;
528
529 /* Try honoring the hint first */
530 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
531 if (assign->assigned) {
532 list_for_each_entry(c, &iface->ia_assignments, head) {
533 if (c->length == 128 || c->length == 0)
534 continue;
535
536 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
537 list_add_tail(&assign->head, &c->head);
538
539 if (assign->flags & OAF_BOUND)
540 apply_lease(iface, assign, true);
541
542 return true;
543 }
544
545 if (c->assigned != 0)
546 current = (c->assigned + (1 << (64 - c->length)));
547 }
548 }
549
550 /* Fallback to a variable assignment */
551 current = 1;
552 list_for_each_entry(c, &iface->ia_assignments, head) {
553 if (c->length == 128 || c->length == 0)
554 continue;
555
556 current = (current + asize) & (~asize);
557 if (current + asize < c->assigned) {
558 assign->assigned = current;
559 list_add_tail(&assign->head, &c->head);
560
561 if (assign->flags & OAF_BOUND)
562 apply_lease(iface, assign, true);
563
564 return true;
565 }
566
567 if (c->assigned != 0)
568 current = (c->assigned + (1 << (64 - c->length)));
569 }
570
571 return false;
572 }
573
574 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
575 {
576 /* Seed RNG with checksum of DUID */
577 uint32_t seed = 0;
578 for (size_t i = 0; i < assign->clid_len; ++i)
579 seed += assign->clid_data[i];
580 srand(seed);
581
582 /* Try to assign up to 100x */
583 for (size_t i = 0; i < 100; ++i) {
584 uint32_t try;
585 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
586
587 struct dhcpv6_assignment *c;
588 list_for_each_entry(c, &iface->ia_assignments, head) {
589 if (c->length == 0)
590 continue;
591
592 if (c->assigned > try || c->length != 128) {
593 assign->assigned = try;
594 list_add_tail(&assign->head, &c->head);
595 return true;
596 } else if (c->assigned == try)
597 break;
598 }
599 }
600
601 return false;
602 }
603
604 void dhcpv6_ia_preupdate(struct interface *iface)
605 {
606 if (iface->dhcpv6 != RELAYD_SERVER)
607 return;
608
609 struct dhcpv6_assignment *c, *border = list_last_entry(
610 &iface->ia_assignments, struct dhcpv6_assignment, head);
611
612 list_for_each_entry(c, &iface->ia_assignments, head)
613 if (c != border && !iface->managed && (c->flags & OAF_BOUND))
614 apply_lease(iface, c, false);
615 }
616
617 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
618 {
619 if (iface->dhcpv6 != RELAYD_SERVER)
620 return;
621
622 int minprefix = -1;
623 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
624 if (iface->ia_addr[i].preferred > (uint32_t)now &&
625 iface->ia_addr[i].prefix < 64 &&
626 iface->ia_addr[i].prefix > minprefix)
627 minprefix = iface->ia_addr[i].prefix;
628 }
629
630 struct dhcpv6_assignment *border = list_last_entry(
631 &iface->ia_assignments, struct dhcpv6_assignment, head);
632
633 if (minprefix > 32 && minprefix <= 64)
634 border->assigned = 1U << (64 - minprefix);
635 else
636 border->assigned = 0;
637
638 struct list_head reassign = LIST_HEAD_INIT(reassign);
639 struct dhcpv6_assignment *c, *d;
640 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
641 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
642 c->managed_size)
643 continue;
644
645 if (c->length < 128 && c->assigned >= border->assigned && c != border)
646 list_move(&c->head, &reassign);
647 else if (c != border && (c->flags & OAF_BOUND))
648 apply_lease(iface, c, true);
649
650 if (c->accept_reconf && c->reconf_cnt == 0) {
651 c->reconf_cnt = 1;
652 c->reconf_sent = now;
653 send_reconf(iface, c);
654
655 /* Leave all other assignments of that client alone */
656 struct dhcpv6_assignment *a;
657 list_for_each_entry(a, &iface->ia_assignments, head)
658 if (a != c && a->clid_len == c->clid_len &&
659 !memcmp(a->clid_data, c->clid_data, a->clid_len))
660 c->reconf_cnt = INT_MAX;
661 }
662 }
663
664 while (!list_empty(&reassign)) {
665 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
666 list_del(&c->head);
667 if (!assign_pd(iface, c)) {
668 c->assigned = 0;
669 list_add(&c->head, &iface->ia_assignments);
670 }
671 }
672
673 dhcpv6_write_statefile();
674 }
675
676 static void reconf_timer(struct uloop_timeout *event)
677 {
678 time_t now = odhcpd_time();
679 struct interface *iface;
680 list_for_each_entry(iface, &interfaces, head) {
681 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
682 continue;
683
684 struct dhcpv6_assignment *a, *n;
685 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
686 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
687 if ((a->length < 128 && a->clid_len > 0) ||
688 (a->length == 128 && a->clid_len == 0))
689 free_dhcpv6_assignment(a);
690
691 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
692 now > a->reconf_sent + (1 << a->reconf_cnt)) {
693 ++a->reconf_cnt;
694 a->reconf_sent = now;
695 send_reconf(iface, a);
696 }
697 }
698 }
699 uloop_timeout_set(event, 2000);
700 }
701
702 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
703 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
704 struct interface *iface, bool request)
705 {
706 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
707 return 0;
708
709 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
710 size_t datalen = sizeof(out);
711 time_t now = odhcpd_time();
712
713 if (status) {
714 struct __attribute__((packed)) {
715 uint16_t type;
716 uint16_t len;
717 uint16_t value;
718 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
719 htons(status)};
720
721 memcpy(buf + datalen, &stat, sizeof(stat));
722 datalen += sizeof(stat);
723 } else {
724 if (a) {
725 uint32_t leasetime;
726 if (a->leasetime)
727 leasetime = a->leasetime;
728 else
729 leasetime = iface->dhcpv4_leasetime;
730
731 uint32_t pref = leasetime;
732 uint32_t valid = leasetime;
733
734 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
735 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
736 size_t m = elect_addr(addrs, addrlen);
737
738 for (size_t i = 0; i < addrlen; ++i) {
739 uint32_t prefix_pref = addrs[i].preferred;
740 uint32_t prefix_valid = addrs[i].valid;
741
742 if (!valid_addr(&addrs[i], now))
743 continue;
744
745 if (prefix_pref != UINT32_MAX)
746 prefix_pref -= now;
747
748 if (prefix_valid != UINT32_MAX)
749 prefix_valid -= now;
750
751 if (a->length < 128) {
752 struct dhcpv6_ia_prefix p = {
753 .type = htons(DHCPV6_OPT_IA_PREFIX),
754 .len = htons(sizeof(p) - 4),
755 .preferred = htonl(prefix_pref),
756 .valid = htonl(prefix_valid),
757 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
758 .addr = addrs[i].addr
759 };
760 p.addr.s6_addr32[1] |= htonl(a->assigned);
761 p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
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 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
839
840 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
841 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
842 found = true;
843 } else {
844 addr.s6_addr32[3] = htonl(a->assigned);
845
846 if (!memcmp(&n->addr, &addr, sizeof(addr)))
847 found = true;
848 }
849 }
850 }
851
852 if (!found) {
853 if (otype == DHCPV6_OPT_IA_PREFIX) {
854 struct dhcpv6_ia_prefix inv = {
855 .type = htons(DHCPV6_OPT_IA_PREFIX),
856 .len = htons(sizeof(inv) - 4),
857 .preferred = 0,
858 .valid = 0,
859 .prefix = p->prefix,
860 .addr = p->addr
861 };
862
863 if (datalen + sizeof(inv) > buflen)
864 continue;
865
866 memcpy(buf + datalen, &inv, sizeof(inv));
867 datalen += sizeof(inv);
868 } else {
869 struct dhcpv6_ia_addr inv = {
870 .type = htons(DHCPV6_OPT_IA_ADDR),
871 .len = htons(sizeof(inv) - 4),
872 .addr = n->addr,
873 .preferred = 0,
874 .valid = 0
875 };
876
877 if (datalen + sizeof(inv) > buflen)
878 continue;
879
880 memcpy(buf + datalen, &inv, sizeof(inv));
881 datalen += sizeof(inv);
882 }
883 }
884 }
885 }
886 }
887
888 out.len = htons(datalen - 4);
889 memcpy(buf, &out, sizeof(out));
890 return datalen;
891 }
892
893 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
894 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
895 {
896 const char *type = "UNKNOWN";
897 const char *status = "UNKNOWN";
898
899 if (msgtype == DHCPV6_MSG_RENEW)
900 return;
901
902 switch (msgtype) {
903 case DHCPV6_MSG_SOLICIT:
904 type = "SOLICIT";
905 break;
906 case DHCPV6_MSG_REQUEST:
907 type = "REQUEST";
908 break;
909 case DHCPV6_MSG_CONFIRM:
910 type = "CONFIRM";
911 break;
912 case DHCPV6_MSG_RENEW:
913 type = "RENEW";
914 break;
915 case DHCPV6_MSG_REBIND:
916 type = "REBIND";
917 break;
918 case DHCPV6_MSG_RELEASE:
919 type = "RELEASE";
920 break;
921 case DHCPV6_MSG_DECLINE:
922 type = "DECLINE";
923 break;
924 }
925
926 switch (code) {
927 case DHCPV6_STATUS_OK:
928 status = "ok";
929 break;
930 case DHCPV6_STATUS_NOADDRSAVAIL:
931 status = "no addresses available";
932 break;
933 case DHCPV6_STATUS_NOBINDING:
934 status = "no binding";
935 break;
936 case DHCPV6_STATUS_NOTONLINK:
937 status = "not on-link";
938 break;
939 case DHCPV6_STATUS_NOPREFIXAVAIL:
940 status = "no prefix available";
941 break;
942 }
943
944 char leasebuf[256] = "";
945
946 if (a) {
947 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
948 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
949 size_t lbsize = 0;
950 size_t m = elect_addr(addrs, addrlen);
951 char addrbuf[INET6_ADDRSTRLEN];
952
953 for (size_t i = 0; i < addrlen; ++i) {
954 if (!valid_addr(&addrs[i], now))
955 continue;
956
957 struct in6_addr addr = addrs[i].addr;
958 int prefix = a->managed ? addrs[i].prefix : a->length;
959 if (prefix == 128) {
960 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
961 a->assigned == 0)
962 continue;
963
964 addr.s6_addr32[3] = htonl(a->assigned);
965 }
966 else {
967 if (!valid_prefix_length(a, addrs[i].prefix))
968 continue;
969
970 addr.s6_addr32[1] |= htonl(a->assigned);
971 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
972 }
973
974 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
975 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
976 }
977 }
978
979 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
980 duidbuf, iface->ifname, status, leasebuf);
981 }
982
983 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
984 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
985 {
986 time_t now = odhcpd_time();
987 size_t response_len = 0;
988 const struct dhcpv6_client_header *hdr = data;
989 uint8_t *start = (uint8_t*)&hdr[1], *odata;
990 uint16_t otype, olen;
991 /* Find and parse client-id and hostname */
992 bool accept_reconf = false;
993 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
994 char hostname[256];
995 size_t hostname_len = 0;
996 bool notonlink = false;
997 char duidbuf[261];
998
999 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1000 if (otype == DHCPV6_OPT_CLIENTID) {
1001 clid_data = odata;
1002 clid_len = olen;
1003
1004 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1005 memcpy(mac, &odata[8], sizeof(mac));
1006 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1007 memcpy(mac, &odata[4], sizeof(mac));
1008
1009 if (olen <= 130)
1010 odhcpd_hexlify(duidbuf, odata, olen);
1011 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1012 uint8_t fqdn_buf[256];
1013 memcpy(fqdn_buf, odata, olen);
1014 fqdn_buf[olen++] = 0;
1015
1016 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1017 hostname_len = strcspn(hostname, ".");
1018 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1019 accept_reconf = true;
1020 }
1021
1022 if (!clid_data || !clid_len || clid_len > 130)
1023 goto out;
1024
1025 struct dhcpv6_assignment *first = NULL;
1026 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1027 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1028 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1029 bool ia_addr_present = false;
1030 if (!is_pd && !is_na)
1031 continue;
1032
1033 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1034 size_t ia_response_len = 0;
1035 uint8_t reqlen = (is_pd) ? 62 : 128;
1036 uint32_t reqhint = 0;
1037
1038 /* Parse request hint for IA-PD */
1039 if (is_pd) {
1040 uint8_t *sdata;
1041 uint16_t stype, slen;
1042 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1043 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1044 continue;
1045
1046 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1047 if (p->prefix) {
1048 reqlen = p->prefix;
1049 reqhint = ntohl(p->addr.s6_addr32[1]);
1050 if (reqlen > 32 && reqlen <= 64)
1051 reqhint &= (1U << (64 - reqlen)) - 1;
1052 }
1053 }
1054
1055 if (reqlen > 64)
1056 reqlen = 64;
1057 } else if (is_na) {
1058 uint8_t *sdata;
1059 uint16_t stype, slen;
1060 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1061 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1062 continue;
1063
1064 ia_addr_present = true;
1065 }
1066 }
1067
1068 /* Find assignment */
1069 struct dhcpv6_assignment *c, *a = NULL;
1070 list_for_each_entry(c, &iface->ia_assignments, head) {
1071 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1072 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1073 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1074 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1075 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1076 a = c;
1077
1078 /* Reset state */
1079 if (a->flags & OAF_BOUND)
1080 apply_lease(iface, a, false);
1081
1082 memcpy(a->clid_data, clid_data, clid_len);
1083 a->clid_len = clid_len;
1084 a->iaid = ia->iaid;
1085 a->peer = *addr;
1086 a->reconf_cnt = 0;
1087 a->reconf_sent = 0;
1088 break;
1089 }
1090 }
1091
1092 /* Generic message handling */
1093 uint16_t status = DHCPV6_STATUS_OK;
1094 if (a && a->managed_size < 0)
1095 return -1;
1096
1097 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1098 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1099 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1100 bool assigned = !!a;
1101
1102 if (!a && !iface->no_dynamic_dhcp) {
1103 /* Create new binding */
1104 a = calloc(1, sizeof(*a) + clid_len);
1105 if (a) {
1106 a->clid_len = clid_len;
1107 a->iaid = ia->iaid;
1108 a->length = reqlen;
1109 a->peer = *addr;
1110 a->assigned = reqhint;
1111 /* Set valid time to current time indicating */
1112 /* assignment is not having infinite lifetime */
1113 a->valid_until = now;
1114
1115 if (first)
1116 memcpy(a->key, first->key, sizeof(a->key));
1117 else
1118 odhcpd_urandom(a->key, sizeof(a->key));
1119 memcpy(a->clid_data, clid_data, clid_len);
1120
1121 if (is_pd)
1122 while (!(assigned = assign_pd(iface, a)) &&
1123 !a->managed_size && ++a->length <= 64);
1124 else
1125 assigned = assign_na(iface, a);
1126
1127 if (a->managed_size && !assigned)
1128 return -1;
1129 }
1130 }
1131
1132 if (!assigned || iface->ia_addr_len == 0)
1133 /* Set error status */
1134 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1135 else if (assigned && !first && hdr->msg_type != DHCPV6_MSG_REBIND) {
1136 size_t handshake_len = 4;
1137 buf[0] = 0;
1138 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1139 buf[2] = 0;
1140 buf[3] = 0;
1141
1142 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1143 struct dhcpv6_auth_reconfigure auth = {
1144 htons(DHCPV6_OPT_AUTH),
1145 htons(sizeof(auth) - 4),
1146 3, 1, 0,
1147 {htonl(time(NULL)), htonl(++serial)},
1148 1,
1149 {0}
1150 };
1151 memcpy(auth.key, a->key, sizeof(a->key));
1152 memcpy(buf + handshake_len, &auth, sizeof(auth));
1153 handshake_len += sizeof(auth);
1154 }
1155
1156 buf += handshake_len;
1157 buflen -= handshake_len;
1158 response_len += handshake_len;
1159
1160 first = a;
1161 }
1162
1163 ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1164 hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1165
1166 /* Was only a solicitation: mark binding for removal */
1167 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1168 a->flags &= ~OAF_BOUND;
1169
1170 if (!(a->flags & OAF_STATIC))
1171 a->valid_until = now;
1172 } else if (assigned &&
1173 (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1174 hdr->msg_type == DHCPV6_MSG_REBIND)) {
1175 if (hostname_len > 0) {
1176 a->hostname = realloc(a->hostname, hostname_len + 1);
1177 if (a->hostname) {
1178 memcpy(a->hostname, hostname, hostname_len);
1179 a->hostname[hostname_len] = 0;
1180 }
1181 }
1182 a->accept_reconf = accept_reconf;
1183 a->flags |= OAF_BOUND;
1184 apply_lease(iface, a, true);
1185 } else if (!assigned && a && a->managed_size == 0) {
1186 /* Cleanup failed assignment */
1187 free_dhcpv6_assignment(a);
1188 a = NULL;
1189 }
1190 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1191 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1192 hdr->msg_type == DHCPV6_MSG_REBIND ||
1193 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1194 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1195 status = DHCPV6_STATUS_NOBINDING;
1196 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1197 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1198 hdr->msg_type == DHCPV6_MSG_REBIND) {
1199 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1200 if (a) {
1201 a->flags |= OAF_BOUND;
1202 apply_lease(iface, a, true);
1203 }
1204 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1205 if (!(a->flags & OAF_STATIC))
1206 a->valid_until = now - 1;
1207
1208 if (a->flags & OAF_BOUND) {
1209 apply_lease(iface, a, false);
1210 a->flags &= ~OAF_BOUND;
1211 }
1212 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1213 a->flags &= ~OAF_BOUND;
1214
1215 if (!(a->flags & OAF_STATIC)) {
1216 a->clid_len = 0;
1217 a->valid_until = now + 3600; /* Block address for 1h */
1218 }
1219 }
1220 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1221 /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1222 status = DHCPV6_STATUS_NOTONLINK;
1223 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1224 notonlink = true;
1225 }
1226
1227 buf += ia_response_len;
1228 buflen -= ia_response_len;
1229 response_len += ia_response_len;
1230 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1231 }
1232
1233 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1234 response_len + 6 < buflen) {
1235 buf[0] = 0;
1236 buf[1] = DHCPV6_OPT_STATUS;
1237 buf[2] = 0;
1238 buf[3] = 2;
1239 buf[4] = 0;
1240 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1241 response_len += 6;
1242 }
1243
1244 dhcpv6_write_statefile();
1245
1246 out:
1247 return response_len;
1248 }
OpenWrt DHCP Server