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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 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
38 static void reconf_timer(struct uloop_timeout *event);
39 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
40 static uint32_t serial = 0;
41 static uint8_t statemd5[16];
42
43 int dhcpv6_ia_init(void)
44 {
45 uloop_timeout_set(&reconf_event, 2000);
46 return 0;
47 }
48
49 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
50 {
51 if (!enable && iface->ia_assignments.next) {
52 struct dhcpv6_assignment *c;
53 while (!list_empty(&iface->ia_assignments)) {
54 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
55 free_dhcpv6_assignment(c);
56 }
57 }
58
59 if (enable && iface->dhcpv6 == RELAYD_SERVER) {
60 if (!iface->ia_assignments.next)
61 INIT_LIST_HEAD(&iface->ia_assignments);
62
63 if (list_empty(&iface->ia_assignments)) {
64 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
65 if (!border) {
66 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
67 return -1;
68 }
69
70 border->length = 64;
71 list_add(&border->head, &iface->ia_assignments);
72 }
73
74 /* Parse static entries */
75 struct lease *lease;
76 list_for_each_entry(lease, &leases, head) {
77 /* Construct entry */
78 size_t duid_len = lease->duid_len ? lease->duid_len : 14;
79 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
80 if (!a) {
81 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
82 iface->ifname);
83 return -1;
84 }
85
86 if (lease->dhcpv4_leasetime > 0)
87 a->leasetime = lease->dhcpv4_leasetime;
88
89 a->clid_len = duid_len;
90 a->length = 128;
91 if (lease->hostid) {
92 a->assigned = lease->hostid;
93 } else {
94 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
95 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
96 }
97
98 odhcpd_urandom(a->key, sizeof(a->key));
99 memcpy(a->clid_data, lease->duid, lease->duid_len);
100 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
101 /* Static assignment */
102 a->flags |= OAF_STATIC;
103 /* Infinite valid */
104 a->valid_until = 0;
105
106 // Assign to all interfaces
107 struct dhcpv6_assignment *c;
108 list_for_each_entry(c, &iface->ia_assignments, head) {
109 if (c->length != 128 || c->assigned > a->assigned) {
110 list_add_tail(&a->head, &c->head);
111 break;
112 } else if (c->assigned == a->assigned)
113 /* Already an assignment with that number */
114 break;
115 }
116
117 if (a->head.next) {
118 if (lease->hostname[0]) {
119 free(a->hostname);
120 a->hostname = strdup(lease->hostname);
121 }
122 } else
123 free_dhcpv6_assignment(a);
124 }
125 }
126 return 0;
127 }
128
129 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
130 {
131 if (c->managed_sock.fd.registered) {
132 ustream_free(&c->managed_sock.stream);
133 close(c->managed_sock.fd.fd);
134 }
135
136 if (c->head.next)
137 list_del(&c->head);
138
139 free(c->managed);
140 free(c->hostname);
141 free(c);
142 }
143
144 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
145 {
146 struct {
147 struct dhcpv6_client_header hdr;
148 uint16_t srvid_type;
149 uint16_t srvid_len;
150 uint16_t duid_type;
151 uint16_t hardware_type;
152 uint8_t mac[6];
153 uint16_t msg_type;
154 uint16_t msg_len;
155 uint8_t msg_id;
156 struct dhcpv6_auth_reconfigure auth;
157 uint16_t clid_type;
158 uint16_t clid_len;
159 uint8_t clid_data[128];
160 } __attribute__((packed)) reconf_msg = {
161 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
162 .srvid_type = htons(DHCPV6_OPT_SERVERID),
163 .srvid_len = htons(10),
164 .duid_type = htons(3),
165 .hardware_type = htons(1),
166 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
167 .msg_len = htons(1),
168 .msg_id = DHCPV6_MSG_RENEW,
169 .auth = {htons(DHCPV6_OPT_AUTH),
170 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
171 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
172 .clid_type = htons(DHCPV6_OPT_CLIENTID),
173 .clid_len = htons(assign->clid_len),
174 .clid_data = {0},
175 };
176
177 odhcpd_get_mac(iface, reconf_msg.mac);
178 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
179 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
180
181 md5_ctx_t md5;
182 uint8_t secretbytes[64];
183 memset(secretbytes, 0, sizeof(secretbytes));
184 memcpy(secretbytes, assign->key, sizeof(assign->key));
185
186 for (size_t i = 0; i < sizeof(secretbytes); ++i)
187 secretbytes[i] ^= 0x36;
188
189 md5_begin(&md5);
190 md5_hash(secretbytes, sizeof(secretbytes), &md5);
191 md5_hash(iov.iov_base, iov.iov_len, &md5);
192 md5_end(reconf_msg.auth.key, &md5);
193
194 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
195 secretbytes[i] ^= 0x36;
196 secretbytes[i] ^= 0x5c;
197 }
198
199 md5_begin(&md5);
200 md5_hash(secretbytes, sizeof(secretbytes), &md5);
201 md5_hash(reconf_msg.auth.key, 16, &md5);
202 md5_end(reconf_msg.auth.key, &md5);
203
204 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
205 }
206
207 void dhcpv6_write_statefile(void)
208 {
209 md5_ctx_t md5;
210 md5_begin(&md5);
211
212 if (config.dhcp_statefile) {
213 time_t now = odhcpd_time(), wall_time = time(NULL);
214 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
215 if (fd < 0)
216 return;
217
218 lockf(fd, F_LOCK, 0);
219 if (ftruncate(fd, 0) < 0) {}
220
221 FILE *fp = fdopen(fd, "w");
222 if (!fp) {
223 close(fd);
224 return;
225 }
226
227 struct interface *iface;
228 list_for_each_entry(iface, &interfaces, head) {
229 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
230 continue;
231
232 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
233 struct dhcpv6_assignment *c;
234 list_for_each_entry(c, &iface->ia_assignments, head) {
235 if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
236 continue;
237
238 char ipbuf[INET6_ADDRSTRLEN];
239 char leasebuf[512];
240 char duidbuf[264];
241 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
242
243 // iface DUID iaid hostname lifetime assigned length [addrs...]
244 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
245 iface->ifname, duidbuf, ntohl(c->iaid),
246 (c->hostname ? c->hostname : "-"),
247 (c->valid_until > now ?
248 (c->valid_until - now + wall_time) :
249 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
250 c->assigned, (unsigned)c->length);
251
252 struct in6_addr addr;
253 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
254 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
255 size_t m = 0;
256
257 for (size_t i = 0; i < addrlen; ++i)
258 if (addrs[i].preferred > addrs[m].preferred ||
259 (addrs[i].preferred == addrs[m].preferred &&
260 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
261 m = i;
262
263 for (size_t i = 0; i < addrlen; ++i) {
264 if (addrs[i].prefix > 96 || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
265 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
266 addrs[i].prefix == 64))
267 continue;
268
269 addr = addrs[i].addr;
270 if (c->length == 128)
271 addr.s6_addr32[3] = htonl(c->assigned);
272 else
273 addr.s6_addr32[1] |= htonl(c->assigned);
274
275 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
276
277 if (c->length == 128 && c->hostname) {
278 fputs(ipbuf, fp);
279
280 char b[256];
281 if (dn_expand(iface->search, iface->search + iface->search_len,
282 iface->search, b, sizeof(b)) > 0)
283 fprintf(fp, "\t%s.%s", c->hostname, b);
284
285 fprintf(fp, "\t%s\n", c->hostname);
286 md5_hash(ipbuf, strlen(ipbuf), &md5);
287 md5_hash(c->hostname, strlen(c->hostname), &md5);
288 }
289
290 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
291 (c->managed_size) ? addrs[i].prefix : c->length);
292 }
293 leasebuf[l - 1] = '\n';
294 fwrite(leasebuf, 1, l, fp);
295 }
296 }
297
298 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
299 struct dhcpv4_assignment *c;
300 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
301 if (!(c->flags & OAF_BOUND))
302 continue;
303
304 char ipbuf[INET6_ADDRSTRLEN];
305 char leasebuf[512];
306 char duidbuf[16];
307 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
308
309 // iface DUID iaid hostname lifetime assigned length [addrs...]
310 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
311 iface->ifname, duidbuf,
312 (c->hostname ? c->hostname : "-"),
313 (c->valid_until > now ?
314 (c->valid_until - now + wall_time) :
315 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
316 c->addr);
317
318 struct in_addr addr = {htonl(c->addr)};
319 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
320
321 if (c->hostname) {
322 fputs(ipbuf, fp);
323
324 char b[256];
325 if (dn_expand(iface->search, iface->search + iface->search_len,
326 iface->search, b, sizeof(b)) > 0)
327 fprintf(fp, "\t%s.%s", c->hostname, b);
328
329 fprintf(fp, "\t%s\n", c->hostname);
330 md5_hash(ipbuf, strlen(ipbuf), &md5);
331 md5_hash(c->hostname, strlen(c->hostname), &md5);
332 }
333
334 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
335 leasebuf[l - 1] = '\n';
336 fwrite(leasebuf, 1, l, fp);
337 }
338 }
339 }
340
341 fclose(fp);
342 }
343
344 uint8_t newmd5[16];
345 md5_end(newmd5, &md5);
346
347 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
348 memcpy(statemd5, newmd5, sizeof(statemd5));
349 char *argv[2] = {config.dhcp_cb, NULL};
350 if (!vfork()) {
351 execv(argv[0], argv);
352 _exit(128);
353 }
354 }
355 }
356
357
358 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
359 {
360 if (a->length > 64 || a->managed_size < 0)
361 return;
362
363 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
364 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
365
366 for (size_t i = 0; i < addrlen; ++i) {
367 struct in6_addr prefix = addrs[i].addr;
368 prefix.s6_addr32[1] |= htonl(a->assigned);
369 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
370 iface, &a->peer.sin6_addr, 1024, add);
371 }
372 }
373
374 // More data was received from TCP connection
375 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
376 {
377 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
378 time_t now = odhcpd_time();
379 bool first = c->managed_size < 0;
380
381 for (;;) {
382 int pending;
383 char *data = ustream_get_read_buf(s, &pending);
384 char *end = memmem(data, pending, "\n\n", 2);
385
386 if (!end)
387 break;
388
389 end += 2;
390 end[-1] = 0;
391
392 c->managed_size = 0;
393 if (c->accept_reconf)
394 c->reconf_cnt = 1;
395
396 char *saveptr;
397 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
398 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
399 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
400
401 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
402 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
403 continue;
404
405 x = strtok_r(NULL, ",", &saveptr2);
406 if (sscanf(x, "%hhu", &n->prefix) < 1)
407 continue;
408
409 x = strtok_r(NULL, ",", &saveptr2);
410 if (sscanf(x, "%u", &n->preferred) < 1)
411 continue;
412
413 x = strtok_r(NULL, ",", &saveptr2);
414 if (sscanf(x, "%u", &n->valid) < 1)
415 continue;
416
417 if (n->preferred > n->valid)
418 continue;
419
420 if (UINT32_MAX - now < n->preferred)
421 n->preferred = UINT32_MAX;
422 else
423 n->preferred += now;
424
425 if (UINT32_MAX - now < n->valid)
426 n->valid = UINT32_MAX;
427 else
428 n->valid += now;
429
430 n->dprefix = 0;
431
432 ++c->managed_size;
433 }
434
435 ustream_consume(s, end - data);
436 }
437
438 if (first && c->managed_size == 0)
439 free_dhcpv6_assignment(c);
440 else if (first)
441 c->valid_until = now + 150;
442 }
443
444
445 /* TCP transmission has ended, either because of success or timeout or other error */
446 static void managed_handle_pd_done(struct ustream *s)
447 {
448 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
449
450 c->valid_until = odhcpd_time() + 15;
451 c->managed_size = 0;
452
453 if (c->accept_reconf)
454 c->reconf_cnt = 1;
455 }
456
457 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
458 {
459 struct dhcpv6_assignment *c;
460
461 if (iface->dhcpv6_pd_manager[0]) {
462 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
463 if (fd >= 0) {
464 char iaidbuf[298];
465 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
466
467 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
468 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
469 ustream_fd_init(&assign->managed_sock, fd);
470 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
471 iaidbuf, assign->iaid, assign->length);
472 ustream_write_pending(&assign->managed_sock.stream);
473 assign->managed_size = -1;
474 assign->valid_until = odhcpd_time() + 15;
475 list_add(&assign->head, &iface->ia_assignments);
476
477 /* Wait initial period of up to 250ms for immediate assignment */
478 struct pollfd pfd = { .fd = fd, .events = POLLIN };
479 poll(&pfd, 1, 250);
480 managed_handle_pd_data(&assign->managed_sock.stream, 0);
481
482 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
483 return true;
484 }
485
486 return false;
487 } else if (iface->ia_addr_len < 1)
488 return false;
489
490 /* Try honoring the hint first */
491 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
492 if (assign->assigned) {
493 list_for_each_entry(c, &iface->ia_assignments, head) {
494 if (c->length == 128 || c->length == 0)
495 continue;
496
497 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
498 list_add_tail(&assign->head, &c->head);
499 apply_lease(iface, assign, true);
500 return true;
501 }
502
503 if (c->assigned != 0)
504 current = (c->assigned + (1 << (64 - c->length)));
505 }
506 }
507
508 /* Fallback to a variable assignment */
509 current = 1;
510 list_for_each_entry(c, &iface->ia_assignments, head) {
511 if (c->length == 128 || c->length == 0)
512 continue;
513
514 current = (current + asize) & (~asize);
515 if (current + asize < c->assigned) {
516 assign->assigned = current;
517 list_add_tail(&assign->head, &c->head);
518 apply_lease(iface, assign, true);
519 return true;
520 }
521
522 if (c->assigned != 0)
523 current = (c->assigned + (1 << (64 - c->length)));
524 }
525
526 return false;
527 }
528
529 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
530 {
531 /* Seed RNG with checksum of DUID */
532 uint32_t seed = 0;
533 for (size_t i = 0; i < assign->clid_len; ++i)
534 seed += assign->clid_data[i];
535 srand(seed);
536
537 /* Try to assign up to 100x */
538 for (size_t i = 0; i < 100; ++i) {
539 uint32_t try;
540 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
541
542 struct dhcpv6_assignment *c;
543 list_for_each_entry(c, &iface->ia_assignments, head) {
544 if (c->length == 0)
545 continue;
546
547 if (c->assigned > try || c->length != 128) {
548 assign->assigned = try;
549 list_add_tail(&assign->head, &c->head);
550 return true;
551 } else if (c->assigned == try)
552 break;
553 }
554 }
555
556 return false;
557 }
558
559 void dhcpv6_ia_preupdate(struct interface *iface)
560 {
561 if (iface->dhcpv6 != RELAYD_SERVER)
562 return;
563
564 struct dhcpv6_assignment *c, *border = list_last_entry(
565 &iface->ia_assignments, struct dhcpv6_assignment, head);
566
567 list_for_each_entry(c, &iface->ia_assignments, head)
568 if (c != border && !iface->managed)
569 apply_lease(iface, c, false);
570 }
571
572 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
573 {
574 if (iface->dhcpv6 != RELAYD_SERVER)
575 return;
576
577 int minprefix = -1;
578 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
579 if (iface->ia_addr[i].preferred > (uint32_t)now &&
580 iface->ia_addr[i].prefix < 64 &&
581 iface->ia_addr[i].prefix > minprefix)
582 minprefix = iface->ia_addr[i].prefix;
583 }
584
585 struct dhcpv6_assignment *border = list_last_entry(
586 &iface->ia_assignments, struct dhcpv6_assignment, head);
587
588 if (minprefix > 32 && minprefix <= 64)
589 border->assigned = 1U << (64 - minprefix);
590 else
591 border->assigned = 0;
592
593 struct list_head reassign = LIST_HEAD_INIT(reassign);
594 struct dhcpv6_assignment *c, *d;
595 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
596 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
597 c->managed_size)
598 continue;
599
600 if (c->length < 128 && c->assigned >= border->assigned && c != border)
601 list_move(&c->head, &reassign);
602 else if (c != border)
603 apply_lease(iface, c, true);
604
605 if (c->accept_reconf && c->reconf_cnt == 0) {
606 c->reconf_cnt = 1;
607 c->reconf_sent = now;
608 send_reconf(iface, c);
609
610 /* Leave all other assignments of that client alone */
611 struct dhcpv6_assignment *a;
612 list_for_each_entry(a, &iface->ia_assignments, head)
613 if (a != c && a->clid_len == c->clid_len &&
614 !memcmp(a->clid_data, c->clid_data, a->clid_len))
615 c->reconf_cnt = INT_MAX;
616 }
617 }
618
619 while (!list_empty(&reassign)) {
620 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
621 list_del(&c->head);
622 if (!assign_pd(iface, c)) {
623 c->assigned = 0;
624 list_add(&c->head, &iface->ia_assignments);
625 }
626 }
627
628 dhcpv6_write_statefile();
629 }
630
631 static void reconf_timer(struct uloop_timeout *event)
632 {
633 time_t now = odhcpd_time();
634 struct interface *iface;
635 list_for_each_entry(iface, &interfaces, head) {
636 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
637 continue;
638
639 struct dhcpv6_assignment *a, *n;
640 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
641 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
642 if ((a->length < 128 && a->clid_len > 0) ||
643 (a->length == 128 && a->clid_len == 0)) {
644 list_del(&a->head);
645 free_dhcpv6_assignment(a);
646 }
647 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
648 now > a->reconf_sent + (1 << a->reconf_cnt)) {
649 ++a->reconf_cnt;
650 a->reconf_sent = now;
651 send_reconf(iface, a);
652 }
653 }
654 }
655 uloop_timeout_set(event, 2000);
656 }
657
658 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
659 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
660 struct interface *iface, bool request)
661 {
662 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
663 return 0;
664
665 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
666 size_t datalen = sizeof(out);
667 time_t now = odhcpd_time();
668
669 if (status) {
670 struct __attribute__((packed)) {
671 uint16_t type;
672 uint16_t len;
673 uint16_t value;
674 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
675 htons(status)};
676
677 memcpy(buf + datalen, &stat, sizeof(stat));
678 datalen += sizeof(stat);
679 } else {
680 if (a) {
681 uint32_t leasetime;
682 if (a->leasetime > 0)
683 leasetime = a->leasetime;
684 else
685 leasetime = iface->dhcpv4_leasetime;
686
687 if (leasetime == 0)
688 leasetime = 3600;
689 else if (leasetime < 60)
690 leasetime = 60;
691
692 uint32_t pref = leasetime;
693 uint32_t valid = leasetime;
694
695 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
696 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
697 size_t m = 0;
698
699 for (size_t i = 0; i < addrlen; ++i)
700 if (addrs[i].preferred > addrs[m].preferred ||
701 (addrs[i].preferred == addrs[m].preferred &&
702 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
703 m = i;
704
705 for (size_t i = 0; i < addrlen; ++i) {
706 uint32_t prefix_pref = addrs[i].preferred;
707 uint32_t prefix_valid = addrs[i].valid;
708
709 if (addrs[i].prefix > 96 ||
710 addrs[i].preferred <= (uint32_t)now)
711 continue;
712
713 if (prefix_pref != UINT32_MAX)
714 prefix_pref -= now;
715
716 if (prefix_valid != UINT32_MAX)
717 prefix_valid -= now;
718
719 if (a->length < 128) {
720 struct dhcpv6_ia_prefix p = {
721 .type = htons(DHCPV6_OPT_IA_PREFIX),
722 .len = htons(sizeof(p) - 4),
723 .preferred = htonl(prefix_pref),
724 .valid = htonl(prefix_valid),
725 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
726 .addr = addrs[i].addr
727 };
728 p.addr.s6_addr32[1] |= htonl(a->assigned);
729
730 size_t entrlen = sizeof(p) - 4;
731
732 if (datalen + entrlen + 4 > buflen ||
733 (a->assigned == 0 && a->managed_size == 0) ||
734 (!a->managed_size && a->length <= addrs[i].prefix))
735 continue;
736
737 memcpy(buf + datalen, &p, sizeof(p));
738 datalen += entrlen + 4;
739 } else {
740 struct dhcpv6_ia_addr n = {
741 .type = htons(DHCPV6_OPT_IA_ADDR),
742 .len = htons(sizeof(n) - 4),
743 .addr = addrs[i].addr,
744 .preferred = htonl(prefix_pref),
745 .valid = htonl(prefix_valid)
746 };
747 n.addr.s6_addr32[3] = htonl(a->assigned);
748 size_t entrlen = sizeof(n) - 4;
749
750 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
751 addrs[i].prefix <= 64)
752 continue;
753
754 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
755 continue;
756
757 memcpy(buf + datalen, &n, sizeof(n));
758 datalen += entrlen + 4;
759 }
760
761 /* Calculate T1 / T2 based on non-deprecated addresses */
762 if (prefix_pref > 0) {
763 if (prefix_pref < pref)
764 pref = prefix_pref;
765
766 if (prefix_valid < valid)
767 valid = prefix_valid;
768 }
769 }
770
771 if (!INFINITE_VALID(a->valid_until))
772 /* UINT32_MAX is considered as infinite leasetime */
773 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
774
775 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
776 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
777
778 if (!out.t1)
779 out.t1 = htonl(1);
780
781 if (!out.t2)
782 out.t2 = htonl(1);
783 }
784
785 if (!request) {
786 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
787 uint16_t otype, olen;
788 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
789 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
790 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
791 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
792 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
793 continue;
794
795 bool found = false;
796 if (a) {
797 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
798 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
799
800 for (size_t i = 0; i < addrlen; ++i) {
801 if (addrs[i].prefix > 96 ||
802 addrs[i].preferred <= (uint32_t)now)
803 continue;
804
805 struct in6_addr addr = addrs[i].addr;
806 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
807 addr.s6_addr32[1] |= htonl(a->assigned);
808
809 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
810 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
811 found = true;
812 } else {
813 addr.s6_addr32[3] = htonl(a->assigned);
814
815 if (!memcmp(&n->addr, &addr, sizeof(addr)))
816 found = true;
817 }
818 }
819 }
820
821 if (!found) {
822 if (otype == DHCPV6_OPT_IA_PREFIX) {
823 struct dhcpv6_ia_prefix inv = {
824 .type = htons(DHCPV6_OPT_IA_PREFIX),
825 .len = htons(sizeof(inv) - 4),
826 .preferred = 0,
827 .valid = 0,
828 .prefix = p->prefix,
829 .addr = p->addr
830 };
831
832 if (datalen + sizeof(inv) > buflen)
833 continue;
834
835 memcpy(buf + datalen, &inv, sizeof(inv));
836 datalen += sizeof(inv);
837 } else {
838 struct dhcpv6_ia_addr inv = {
839 .type = htons(DHCPV6_OPT_IA_ADDR),
840 .len = htons(sizeof(inv) - 4),
841 .addr = n->addr,
842 .preferred = 0,
843 .valid = 0
844 };
845
846 if (datalen + sizeof(inv) > buflen)
847 continue;
848
849 memcpy(buf + datalen, &inv, sizeof(inv));
850 datalen += sizeof(inv);
851 }
852 }
853 }
854 }
855 }
856
857 out.len = htons(datalen - 4);
858 memcpy(buf, &out, sizeof(out));
859 return datalen;
860 }
861
862 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
863 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
864 {
865 const char *type = "UNKNOWN";
866 const char *status = "UNKNOWN";
867
868 if (msgtype == DHCPV6_MSG_RENEW)
869 return;
870
871 switch (msgtype) {
872 case DHCPV6_MSG_SOLICIT:
873 type = "SOLICIT";
874 break;
875 case DHCPV6_MSG_REQUEST:
876 type = "REQUEST";
877 break;
878 case DHCPV6_MSG_CONFIRM:
879 type = "CONFIRM";
880 break;
881 case DHCPV6_MSG_RENEW:
882 type = "RENEW";
883 break;
884 case DHCPV6_MSG_REBIND:
885 type = "REBIND";
886 break;
887 case DHCPV6_MSG_RELEASE:
888 type = "RELEASE";
889 break;
890 case DHCPV6_MSG_DECLINE:
891 type = "DECLINE";
892 break;
893 }
894
895 switch (code) {
896 case DHCPV6_STATUS_OK:
897 status = "ok";
898 break;
899 case DHCPV6_STATUS_NOADDRSAVAIL:
900 status = "no addresses available";
901 break;
902 case DHCPV6_STATUS_NOBINDING:
903 status = "no binding";
904 break;
905 case DHCPV6_STATUS_NOTONLINK:
906 status = "not on-link";
907 break;
908 case DHCPV6_STATUS_NOPREFIXAVAIL:
909 status = "no prefix available";
910 break;
911 }
912
913 char leasebuf[256] = "";
914
915 if (a) {
916 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
917 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
918 size_t lbsize = 0;
919 char addrbuf[INET6_ADDRSTRLEN];
920
921 for (size_t i = 0; i < addrlen; ++i) {
922 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
923 continue;
924
925 struct in6_addr addr = addrs[i].addr;
926 int prefix = a->managed ? addrs[i].prefix : a->length;
927 if (prefix == 128)
928 addr.s6_addr32[3] = htonl(a->assigned);
929 else
930 addr.s6_addr32[1] |= htonl(a->assigned);
931
932 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
933 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
934 }
935 }
936
937 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
938 duidbuf, iface->ifname, status, leasebuf);
939 }
940
941 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
942 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
943 {
944 time_t now = odhcpd_time();
945 size_t response_len = 0;
946 const struct dhcpv6_client_header *hdr = data;
947 uint8_t *start = (uint8_t*)&hdr[1], *odata;
948 uint16_t otype, olen;
949 /* Find and parse client-id and hostname */
950 bool accept_reconf = false;
951 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
952 char hostname[256];
953 size_t hostname_len = 0;
954 bool notonlink = false;
955 char duidbuf[261];
956
957 dhcpv6_for_each_option(start, end, otype, olen, odata) {
958 if (otype == DHCPV6_OPT_CLIENTID) {
959 clid_data = odata;
960 clid_len = olen;
961
962 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
963 memcpy(mac, &odata[8], sizeof(mac));
964 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
965 memcpy(mac, &odata[4], sizeof(mac));
966
967 if (olen <= 130)
968 odhcpd_hexlify(duidbuf, odata, olen);
969 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
970 uint8_t fqdn_buf[256];
971 memcpy(fqdn_buf, odata, olen);
972 fqdn_buf[olen++] = 0;
973
974 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
975 hostname_len = strcspn(hostname, ".");
976 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
977 accept_reconf = true;
978 }
979
980 if (!clid_data || !clid_len || clid_len > 130)
981 goto out;
982
983 struct dhcpv6_assignment *first = NULL;
984 dhcpv6_for_each_option(start, end, otype, olen, odata) {
985 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
986 bool is_na = (otype == DHCPV6_OPT_IA_NA);
987 bool ia_addr_present = false;
988 if (!is_pd && !is_na)
989 continue;
990
991 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
992 size_t ia_response_len = 0;
993 uint8_t reqlen = (is_pd) ? 62 : 128;
994 uint32_t reqhint = 0;
995
996 /* Parse request hint for IA-PD */
997 if (is_pd) {
998 uint8_t *sdata;
999 uint16_t stype, slen;
1000 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1001 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1002 continue;
1003
1004 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1005 if (p->prefix) {
1006 reqlen = p->prefix;
1007 reqhint = ntohl(p->addr.s6_addr32[1]);
1008 if (reqlen > 32 && reqlen <= 64)
1009 reqhint &= (1U << (64 - reqlen)) - 1;
1010 }
1011 }
1012
1013 if (reqlen > 64)
1014 reqlen = 64;
1015 } else if (is_na) {
1016 uint8_t *sdata;
1017 uint16_t stype, slen;
1018 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1019 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1020 continue;
1021
1022 ia_addr_present = true;
1023 }
1024 }
1025
1026 /* Find assignment */
1027 struct dhcpv6_assignment *c, *a = NULL;
1028 list_for_each_entry(c, &iface->ia_assignments, head) {
1029 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1030 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1031 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1032 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1033 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1034 a = c;
1035
1036 // Reset state
1037 apply_lease(iface, a, false);
1038 memcpy(a->clid_data, clid_data, clid_len);
1039 a->clid_len = clid_len;
1040 a->iaid = ia->iaid;
1041 a->peer = *addr;
1042 a->reconf_cnt = 0;
1043 a->reconf_sent = 0;
1044 break;
1045 }
1046 }
1047
1048 /* Generic message handling */
1049 uint16_t status = DHCPV6_STATUS_OK;
1050 if (a && a->managed_size < 0)
1051 return -1;
1052
1053 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1054 bool assigned = !!a;
1055
1056 if (!a && !iface->no_dynamic_dhcp) {
1057 /* Create new binding */
1058 a = calloc(1, sizeof(*a) + clid_len);
1059 if (a) {
1060 a->clid_len = clid_len;
1061 a->iaid = ia->iaid;
1062 a->length = reqlen;
1063 a->peer = *addr;
1064 a->assigned = reqhint;
1065 /* Set valid time to current time indicating */
1066 /* assignment is not having infinite lifetime */
1067 a->valid_until = now;
1068
1069 if (first)
1070 memcpy(a->key, first->key, sizeof(a->key));
1071 else
1072 odhcpd_urandom(a->key, sizeof(a->key));
1073 memcpy(a->clid_data, clid_data, clid_len);
1074
1075 if (is_pd)
1076 while (!(assigned = assign_pd(iface, a)) &&
1077 !a->managed_size && ++a->length <= 64);
1078 else
1079 assigned = assign_na(iface, a);
1080
1081 if (a->managed_size && !assigned)
1082 return -1;
1083 }
1084 }
1085
1086 if (!assigned || iface->ia_addr_len == 0)
1087 /* Set error status */
1088 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1089 else if (assigned && !first) {
1090 size_t handshake_len = 4;
1091 buf[0] = 0;
1092 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1093 buf[2] = 0;
1094 buf[3] = 0;
1095
1096 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1097 struct dhcpv6_auth_reconfigure auth = {
1098 htons(DHCPV6_OPT_AUTH),
1099 htons(sizeof(auth) - 4),
1100 3, 1, 0,
1101 {htonl(time(NULL)), htonl(++serial)},
1102 1,
1103 {0}
1104 };
1105 memcpy(auth.key, a->key, sizeof(a->key));
1106 memcpy(buf + handshake_len, &auth, sizeof(auth));
1107 handshake_len += sizeof(auth);
1108 }
1109
1110 buf += handshake_len;
1111 buflen -= handshake_len;
1112 response_len += handshake_len;
1113
1114 first = a;
1115 }
1116
1117 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1118
1119 /* Was only a solicitation: mark binding for removal */
1120 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1121 a->flags &= ~OAF_BOUND;
1122
1123 if (!(a->flags & OAF_STATIC))
1124 a->valid_until = now;
1125 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1126 if (hostname_len > 0) {
1127 a->hostname = realloc(a->hostname, hostname_len + 1);
1128 if (a->hostname) {
1129 memcpy(a->hostname, hostname, hostname_len);
1130 a->hostname[hostname_len] = 0;
1131 }
1132 }
1133 a->accept_reconf = accept_reconf;
1134 a->flags |= OAF_BOUND;
1135 apply_lease(iface, a, true);
1136 } else if (!assigned && a && a->managed_size == 0)
1137 /* Cleanup failed assignment */
1138 free_dhcpv6_assignment(a);
1139
1140 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1141 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1142 hdr->msg_type == DHCPV6_MSG_REBIND ||
1143 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1144 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1145 status = DHCPV6_STATUS_NOBINDING;
1146 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1147 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1148 hdr->msg_type == DHCPV6_MSG_REBIND) {
1149 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1150 if (a) {
1151 a->flags |= OAF_BOUND;
1152 apply_lease(iface, a, true);
1153 }
1154 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1155 if (!(a->flags & OAF_STATIC))
1156 a->valid_until = now - 1;
1157
1158 a->flags &= ~OAF_BOUND;
1159 apply_lease(iface, a, false);
1160 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1161 a->flags &= ~OAF_BOUND;
1162
1163 if (!(a->flags & OAF_STATIC)) {
1164 a->clid_len = 0;
1165 a->valid_until = now + 3600; /* Block address for 1h */
1166 }
1167 }
1168 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1169 /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1170 status = DHCPV6_STATUS_NOTONLINK;
1171 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1172 notonlink = true;
1173 }
1174
1175 buf += ia_response_len;
1176 buflen -= ia_response_len;
1177 response_len += ia_response_len;
1178 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1179 }
1180
1181 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1182 response_len + 6 < buflen) {
1183 buf[0] = 0;
1184 buf[1] = DHCPV6_OPT_STATUS;
1185 buf[2] = 0;
1186 buf[3] = 2;
1187 buf[4] = 0;
1188 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1189 response_len += 6;
1190 }
1191
1192 dhcpv6_write_statefile();
1193
1194 out:
1195 return response_len;
1196 }
OpenWrt DHCP Server