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dhcpv6-ia: use free_dhcpv6_assignment where needed
[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 odhcpd_urandom(a->key, sizeof(a->key));
98 memcpy(a->clid_data, lease->duid, lease->duid_len);
99 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
100 /* Static assignment */
101 a->flags |= OAF_STATIC;
102 /* Infinite valid */
103 a->valid_until = 0;
104
105 // Assign to all interfaces
106 struct dhcpv6_assignment *c;
107 list_for_each_entry(c, &iface->ia_assignments, head) {
108 if (c->length != 128 || c->assigned > a->assigned) {
109 list_add_tail(&a->head, &c->head);
110 break;
111 } else if (c->assigned == a->assigned) {
112 // Already an assignment with that number
113 break;
114 }
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 c->valid_until = odhcpd_time() + 15;
450 c->managed_size = 0;
451 if (c->accept_reconf)
452 c->reconf_cnt = 1;
453 }
454
455 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
456 {
457 struct dhcpv6_assignment *c;
458
459 if (iface->dhcpv6_pd_manager[0]) {
460 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
461 if (fd >= 0) {
462 char iaidbuf[298];
463 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
464
465 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
466 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
467 ustream_fd_init(&assign->managed_sock, fd);
468 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
469 iaidbuf, assign->iaid, assign->length);
470 ustream_write_pending(&assign->managed_sock.stream);
471 assign->managed_size = -1;
472 assign->valid_until = odhcpd_time() + 15;
473 list_add(&assign->head, &iface->ia_assignments);
474
475 // Wait initial period of up to 250ms for immediate assignment
476 struct pollfd pfd = { .fd = fd, .events = POLLIN };
477 poll(&pfd, 1, 250);
478 managed_handle_pd_data(&assign->managed_sock.stream, 0);
479
480 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
481 return true;
482 }
483
484 return false;
485 } else if (iface->ia_addr_len < 1) {
486 return false;
487 }
488
489 // Try honoring the hint first
490 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
491 if (assign->assigned) {
492 list_for_each_entry(c, &iface->ia_assignments, head) {
493 if (c->length == 128 || c->length == 0)
494 continue;
495
496 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
497 list_add_tail(&assign->head, &c->head);
498 apply_lease(iface, assign, true);
499 return true;
500 }
501
502 if (c->assigned != 0)
503 current = (c->assigned + (1 << (64 - c->length)));
504 }
505 }
506
507 // Fallback to a variable assignment
508 current = 1;
509 list_for_each_entry(c, &iface->ia_assignments, head) {
510 if (c->length == 128 || c->length == 0)
511 continue;
512
513 current = (current + asize) & (~asize);
514 if (current + asize < c->assigned) {
515 assign->assigned = current;
516 list_add_tail(&assign->head, &c->head);
517 apply_lease(iface, assign, true);
518 return true;
519 }
520
521 if (c->assigned != 0)
522 current = (c->assigned + (1 << (64 - c->length)));
523 }
524
525 return false;
526 }
527
528 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
529 {
530 // Seed RNG with checksum of DUID
531 uint32_t seed = 0;
532 for (size_t i = 0; i < assign->clid_len; ++i)
533 seed += assign->clid_data[i];
534 srand(seed);
535
536 // Try to assign up to 100x
537 for (size_t i = 0; i < 100; ++i) {
538 uint32_t try;
539 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
540
541 struct dhcpv6_assignment *c;
542 list_for_each_entry(c, &iface->ia_assignments, head) {
543 if (c->length == 0)
544 continue;
545
546 if (c->assigned > try || c->length != 128) {
547 assign->assigned = try;
548 list_add_tail(&assign->head, &c->head);
549 return true;
550 } else if (c->assigned == try) {
551 break;
552 }
553 }
554 }
555
556 return false;
557 }
558
559 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 list_for_each_entry(c, &iface->ia_assignments, head)
567 if (c != border && !iface->managed)
568 apply_lease(iface, c, false);
569 }
570
571 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
572 {
573 if (iface->dhcpv6 != RELAYD_SERVER)
574 return;
575
576 int minprefix = -1;
577 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
578 if (iface->ia_addr[i].preferred > (uint32_t)now &&
579 iface->ia_addr[i].prefix < 64 &&
580 iface->ia_addr[i].prefix > minprefix)
581 minprefix = iface->ia_addr[i].prefix;
582 }
583
584 struct dhcpv6_assignment *border = list_last_entry(
585 &iface->ia_assignments, struct dhcpv6_assignment, head);
586 if (minprefix > 32 && minprefix <= 64)
587 border->assigned = 1U << (64 - minprefix);
588 else
589 border->assigned = 0;
590
591 struct list_head reassign = LIST_HEAD_INIT(reassign);
592 struct dhcpv6_assignment *c, *d;
593 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
594 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
595 c->managed_size)
596 continue;
597
598 if (c->length < 128 && c->assigned >= border->assigned && c != border)
599 list_move(&c->head, &reassign);
600 else if (c != border)
601 apply_lease(iface, c, true);
602
603 if (c->accept_reconf && c->reconf_cnt == 0) {
604 c->reconf_cnt = 1;
605 c->reconf_sent = now;
606 send_reconf(iface, c);
607
608 // Leave all other assignments of that client alone
609 struct dhcpv6_assignment *a;
610 list_for_each_entry(a, &iface->ia_assignments, head)
611 if (a != c && a->clid_len == c->clid_len &&
612 !memcmp(a->clid_data, c->clid_data, a->clid_len))
613 c->reconf_cnt = INT_MAX;
614 }
615 }
616
617 while (!list_empty(&reassign)) {
618 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
619 list_del(&c->head);
620 if (!assign_pd(iface, c)) {
621 c->assigned = 0;
622 list_add(&c->head, &iface->ia_assignments);
623 }
624 }
625
626 dhcpv6_write_statefile();
627 }
628
629 static void reconf_timer(struct uloop_timeout *event)
630 {
631 time_t now = odhcpd_time();
632 struct interface *iface;
633 list_for_each_entry(iface, &interfaces, head) {
634 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
635 continue;
636
637 struct dhcpv6_assignment *a, *n;
638 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
639 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
640 if ((a->length < 128 && a->clid_len > 0) ||
641 (a->length == 128 && a->clid_len == 0)) {
642 list_del(&a->head);
643 free_dhcpv6_assignment(a);
644 }
645 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
646 now > a->reconf_sent + (1 << a->reconf_cnt)) {
647 ++a->reconf_cnt;
648 a->reconf_sent = now;
649 send_reconf(iface, a);
650 }
651 }
652 }
653 uloop_timeout_set(event, 2000);
654 }
655
656 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
657 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
658 struct interface *iface, bool request)
659 {
660 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
661 return 0;
662
663 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
664 size_t datalen = sizeof(out);
665 time_t now = odhcpd_time();
666
667 if (status) {
668 struct __attribute__((packed)) {
669 uint16_t type;
670 uint16_t len;
671 uint16_t value;
672 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
673 htons(status)};
674
675 memcpy(buf + datalen, &stat, sizeof(stat));
676 datalen += sizeof(stat);
677 } else {
678 if (a) {
679 uint32_t leasetime;
680 if (a->leasetime > 0) {
681 leasetime = a->leasetime;
682 } else {
683 leasetime = iface->dhcpv4_leasetime;
684 }
685 if (leasetime == 0)
686 leasetime = 3600;
687 else if (leasetime < 60)
688 leasetime = 60;
689
690 uint32_t pref = leasetime;
691 uint32_t valid = leasetime;
692
693 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
694 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
695 size_t m = 0;
696
697 for (size_t i = 0; i < addrlen; ++i)
698 if (addrs[i].preferred > addrs[m].preferred ||
699 (addrs[i].preferred == addrs[m].preferred &&
700 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
701 m = i;
702
703 for (size_t i = 0; i < addrlen; ++i) {
704 uint32_t prefix_pref = addrs[i].preferred;
705 uint32_t prefix_valid = addrs[i].valid;
706
707 if (addrs[i].prefix > 96 ||
708 addrs[i].preferred <= (uint32_t)now)
709 continue;
710
711 if (prefix_pref != UINT32_MAX)
712 prefix_pref -= now;
713
714 if (prefix_valid != UINT32_MAX)
715 prefix_valid -= now;
716
717 if (a->length < 128) {
718 struct dhcpv6_ia_prefix p = {
719 .type = htons(DHCPV6_OPT_IA_PREFIX),
720 .len = htons(sizeof(p) - 4),
721 .preferred = htonl(prefix_pref),
722 .valid = htonl(prefix_valid),
723 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
724 .addr = addrs[i].addr
725 };
726 p.addr.s6_addr32[1] |= htonl(a->assigned);
727
728 size_t entrlen = sizeof(p) - 4;
729
730 if (datalen + entrlen + 4 > buflen ||
731 (a->assigned == 0 && a->managed_size == 0) ||
732 (!a->managed_size && a->length <= addrs[i].prefix))
733 continue;
734
735 memcpy(buf + datalen, &p, sizeof(p));
736 datalen += entrlen + 4;
737 } else {
738 struct dhcpv6_ia_addr n = {
739 .type = htons(DHCPV6_OPT_IA_ADDR),
740 .len = htons(sizeof(n) - 4),
741 .addr = addrs[i].addr,
742 .preferred = htonl(prefix_pref),
743 .valid = htonl(prefix_valid)
744 };
745 n.addr.s6_addr32[3] = htonl(a->assigned);
746 size_t entrlen = sizeof(n) - 4;
747
748 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
749 addrs[i].prefix <= 64)
750 continue;
751
752 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
753 continue;
754
755 memcpy(buf + datalen, &n, sizeof(n));
756 datalen += entrlen + 4;
757 }
758
759 // Calculate T1 / T2 based on non-deprecated addresses
760 if (prefix_pref > 0) {
761 if (prefix_pref < pref)
762 pref = prefix_pref;
763
764 if (prefix_valid < valid)
765 valid = prefix_valid;
766 }
767 }
768
769 if (!INFINITE_VALID(a->valid_until))
770 /* UINT32_MAX is considered as infinite leasetime */
771 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
772
773 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
774 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
775
776 if (!out.t1)
777 out.t1 = htonl(1);
778
779 if (!out.t2)
780 out.t2 = htonl(1);
781 }
782
783 if (!request) {
784 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
785 uint16_t otype, olen;
786 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
787 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
788 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
789 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
790 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
791 continue;
792
793 bool found = false;
794 if (a) {
795 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
796 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
797
798 for (size_t i = 0; i < addrlen; ++i) {
799 if (addrs[i].prefix > 96 ||
800 addrs[i].preferred <= (uint32_t)now)
801 continue;
802
803 struct in6_addr addr = addrs[i].addr;
804 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
805 addr.s6_addr32[1] |= htonl(a->assigned);
806
807 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
808 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
809 found = true;
810 } else {
811 addr.s6_addr32[3] = htonl(a->assigned);
812
813 if (!memcmp(&n->addr, &addr, sizeof(addr)))
814 found = true;
815 }
816 }
817 }
818
819 if (!found) {
820 if (otype == DHCPV6_OPT_IA_PREFIX) {
821 struct dhcpv6_ia_prefix inv = {
822 .type = htons(DHCPV6_OPT_IA_PREFIX),
823 .len = htons(sizeof(inv) - 4),
824 .preferred = 0,
825 .valid = 0,
826 .prefix = p->prefix,
827 .addr = p->addr
828 };
829
830 if (datalen + sizeof(inv) > buflen)
831 continue;
832
833 memcpy(buf + datalen, &inv, sizeof(inv));
834 datalen += sizeof(inv);
835 } else {
836 struct dhcpv6_ia_addr inv = {
837 .type = htons(DHCPV6_OPT_IA_ADDR),
838 .len = htons(sizeof(inv) - 4),
839 .addr = n->addr,
840 .preferred = 0,
841 .valid = 0
842 };
843
844 if (datalen + sizeof(inv) > buflen)
845 continue;
846
847 memcpy(buf + datalen, &inv, sizeof(inv));
848 datalen += sizeof(inv);
849 }
850 }
851 }
852 }
853 }
854
855 out.len = htons(datalen - 4);
856 memcpy(buf, &out, sizeof(out));
857 return datalen;
858 }
859
860 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
861 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
862 {
863 const char *type = "UNKNOWN";
864 const char *status = "UNKNOWN";
865
866 if (msgtype == DHCPV6_MSG_RENEW)
867 return;
868
869 switch (msgtype) {
870 case DHCPV6_MSG_SOLICIT:
871 type = "SOLICIT";
872 break;
873 case DHCPV6_MSG_REQUEST:
874 type = "REQUEST";
875 break;
876 case DHCPV6_MSG_CONFIRM:
877 type = "CONFIRM";
878 break;
879 case DHCPV6_MSG_RENEW:
880 type = "RENEW";
881 break;
882 case DHCPV6_MSG_REBIND:
883 type = "REBIND";
884 break;
885 case DHCPV6_MSG_RELEASE:
886 type = "RELEASE";
887 break;
888 case DHCPV6_MSG_DECLINE:
889 type = "DECLINE";
890 break;
891 }
892
893 switch (code) {
894 case DHCPV6_STATUS_OK:
895 status = "ok";
896 break;
897 case DHCPV6_STATUS_NOADDRSAVAIL:
898 status = "no addresses available";
899 break;
900 case DHCPV6_STATUS_NOBINDING:
901 status = "no binding";
902 break;
903 case DHCPV6_STATUS_NOTONLINK:
904 status = "not on-link";
905 break;
906 case DHCPV6_STATUS_NOPREFIXAVAIL:
907 status = "no prefix available";
908 break;
909 }
910
911 char leasebuf[256] = "";
912
913 if (a) {
914 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
915 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
916 size_t lbsize = 0;
917 char addrbuf[INET6_ADDRSTRLEN];
918
919 for (size_t i = 0; i < addrlen; ++i) {
920 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
921 continue;
922
923 struct in6_addr addr = addrs[i].addr;
924 int prefix = a->managed ? addrs[i].prefix : a->length;
925 if (prefix == 128)
926 addr.s6_addr32[3] = htonl(a->assigned);
927 else
928 addr.s6_addr32[1] |= htonl(a->assigned);
929
930 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
931 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
932 }
933 }
934
935 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
936 duidbuf, iface->ifname, status, leasebuf);
937 }
938
939 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
940 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
941 {
942 time_t now = odhcpd_time();
943 size_t response_len = 0;
944 const struct dhcpv6_client_header *hdr = data;
945 uint8_t *start = (uint8_t*)&hdr[1], *odata;
946 uint16_t otype, olen;
947
948 // Find and parse client-id and hostname
949 bool accept_reconf = false;
950 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
951 char hostname[256];
952 size_t hostname_len = 0;
953 bool notonlink = false;
954 char duidbuf[261];
955
956 dhcpv6_for_each_option(start, end, otype, olen, odata) {
957 if (otype == DHCPV6_OPT_CLIENTID) {
958 clid_data = odata;
959 clid_len = olen;
960
961 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
962 memcpy(mac, &odata[8], sizeof(mac));
963 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
964 memcpy(mac, &odata[4], sizeof(mac));
965
966 if (olen <= 130)
967 odhcpd_hexlify(duidbuf, odata, olen);
968 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
969 uint8_t fqdn_buf[256];
970 memcpy(fqdn_buf, odata, olen);
971 fqdn_buf[olen++] = 0;
972
973 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
974 hostname_len = strcspn(hostname, ".");
975 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
976 accept_reconf = true;
977 }
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 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1053 bool assigned = !!a;
1054
1055 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1056 a = calloc(1, sizeof(*a) + clid_len);
1057 if (a) {
1058 a->clid_len = clid_len;
1059 a->iaid = ia->iaid;
1060 a->length = reqlen;
1061 a->peer = *addr;
1062 a->assigned = reqhint;
1063 // Set valid time to current time indicating
1064 // assignment is not having infinite lifetime
1065 a->valid_until = now;
1066
1067 if (first)
1068 memcpy(a->key, first->key, sizeof(a->key));
1069 else
1070 odhcpd_urandom(a->key, sizeof(a->key));
1071 memcpy(a->clid_data, clid_data, clid_len);
1072
1073 if (is_pd)
1074 while (!(assigned = assign_pd(iface, a)) &&
1075 !a->managed_size && ++a->length <= 64);
1076 else
1077 assigned = assign_na(iface, a);
1078
1079 if (a->managed_size && !assigned)
1080 return -1;
1081 }
1082 }
1083
1084 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1085 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1086 } else if (assigned && !first) { //
1087 size_t handshake_len = 4;
1088 buf[0] = 0;
1089 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1090 buf[2] = 0;
1091 buf[3] = 0;
1092
1093 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1094 struct dhcpv6_auth_reconfigure auth = {
1095 htons(DHCPV6_OPT_AUTH),
1096 htons(sizeof(auth) - 4),
1097 3, 1, 0,
1098 {htonl(time(NULL)), htonl(++serial)},
1099 1,
1100 {0}
1101 };
1102 memcpy(auth.key, a->key, sizeof(a->key));
1103 memcpy(buf + handshake_len, &auth, sizeof(auth));
1104 handshake_len += sizeof(auth);
1105 }
1106
1107 buf += handshake_len;
1108 buflen -= handshake_len;
1109 response_len += handshake_len;
1110
1111 first = a;
1112 }
1113
1114 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1115
1116 // Was only a solicitation: mark binding for removal
1117 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1118 a->flags &= ~OAF_BOUND;
1119
1120 if (!(a->flags & OAF_STATIC))
1121 a->valid_until = now;
1122 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1123 if (hostname_len > 0) {
1124 a->hostname = realloc(a->hostname, hostname_len + 1);
1125 if (a->hostname) {
1126 memcpy(a->hostname, hostname, hostname_len);
1127 a->hostname[hostname_len] = 0;
1128 }
1129 }
1130 a->accept_reconf = accept_reconf;
1131 a->flags |= OAF_BOUND;
1132 apply_lease(iface, a, true);
1133 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1134 free_dhcpv6_assignment(a);
1135 }
1136 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1137 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1138 hdr->msg_type == DHCPV6_MSG_REBIND ||
1139 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1140 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1141 status = DHCPV6_STATUS_NOBINDING;
1142 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1143 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1144 hdr->msg_type == DHCPV6_MSG_REBIND) {
1145 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1146 if (a) {
1147 a->flags |= OAF_BOUND;
1148 apply_lease(iface, a, true);
1149 }
1150 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1151 if (!(a->flags & OAF_STATIC))
1152 a->valid_until = now - 1;
1153
1154 a->flags &= ~OAF_BOUND;
1155 apply_lease(iface, a, false);
1156 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1157 a->flags &= ~OAF_BOUND;
1158
1159 if (!(a->flags & OAF_STATIC)) {
1160 a->clid_len = 0;
1161 a->valid_until = now + 3600; // Block address for 1h
1162 }
1163 }
1164 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1165 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1166 status = DHCPV6_STATUS_NOTONLINK;
1167 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1168 notonlink = true;
1169 }
1170
1171 buf += ia_response_len;
1172 buflen -= ia_response_len;
1173 response_len += ia_response_len;
1174 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1175 }
1176
1177 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1178 response_len + 6 < buflen) {
1179 buf[0] = 0;
1180 buf[1] = DHCPV6_OPT_STATUS;
1181 buf[2] = 0;
1182 buf[3] = 2;
1183 buf[4] = 0;
1184 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1185 response_len += 6;
1186 }
1187
1188 dhcpv6_write_statefile();
1189
1190 out:
1191 return response_len;
1192 }
OpenWrt DHCP Server