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dhcpv6-ia: fix delete logic of an assignment in reconf_timer
[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 free_dhcpv6_assignment(a);
645
646 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
647 now > a->reconf_sent + (1 << a->reconf_cnt)) {
648 ++a->reconf_cnt;
649 a->reconf_sent = now;
650 send_reconf(iface, a);
651 }
652 }
653 }
654 uloop_timeout_set(event, 2000);
655 }
656
657 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
658 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
659 struct interface *iface, bool request)
660 {
661 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
662 return 0;
663
664 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
665 size_t datalen = sizeof(out);
666 time_t now = odhcpd_time();
667
668 if (status) {
669 struct __attribute__((packed)) {
670 uint16_t type;
671 uint16_t len;
672 uint16_t value;
673 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
674 htons(status)};
675
676 memcpy(buf + datalen, &stat, sizeof(stat));
677 datalen += sizeof(stat);
678 } else {
679 if (a) {
680 uint32_t leasetime;
681 if (a->leasetime > 0)
682 leasetime = a->leasetime;
683 else
684 leasetime = iface->dhcpv4_leasetime;
685
686 if (leasetime == 0)
687 leasetime = 3600;
688 else if (leasetime < 60)
689 leasetime = 60;
690
691 uint32_t pref = leasetime;
692 uint32_t valid = leasetime;
693
694 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
695 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
696 size_t m = 0;
697
698 for (size_t i = 0; i < addrlen; ++i)
699 if (addrs[i].preferred > addrs[m].preferred ||
700 (addrs[i].preferred == addrs[m].preferred &&
701 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
702 m = i;
703
704 for (size_t i = 0; i < addrlen; ++i) {
705 uint32_t prefix_pref = addrs[i].preferred;
706 uint32_t prefix_valid = addrs[i].valid;
707
708 if (addrs[i].prefix > 96 ||
709 addrs[i].preferred <= (uint32_t)now)
710 continue;
711
712 if (prefix_pref != UINT32_MAX)
713 prefix_pref -= now;
714
715 if (prefix_valid != UINT32_MAX)
716 prefix_valid -= now;
717
718 if (a->length < 128) {
719 struct dhcpv6_ia_prefix p = {
720 .type = htons(DHCPV6_OPT_IA_PREFIX),
721 .len = htons(sizeof(p) - 4),
722 .preferred = htonl(prefix_pref),
723 .valid = htonl(prefix_valid),
724 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
725 .addr = addrs[i].addr
726 };
727 p.addr.s6_addr32[1] |= htonl(a->assigned);
728
729 size_t entrlen = sizeof(p) - 4;
730
731 if (datalen + entrlen + 4 > buflen ||
732 (a->assigned == 0 && a->managed_size == 0) ||
733 (!a->managed_size && a->length <= addrs[i].prefix))
734 continue;
735
736 memcpy(buf + datalen, &p, sizeof(p));
737 datalen += entrlen + 4;
738 } else {
739 struct dhcpv6_ia_addr n = {
740 .type = htons(DHCPV6_OPT_IA_ADDR),
741 .len = htons(sizeof(n) - 4),
742 .addr = addrs[i].addr,
743 .preferred = htonl(prefix_pref),
744 .valid = htonl(prefix_valid)
745 };
746 n.addr.s6_addr32[3] = htonl(a->assigned);
747 size_t entrlen = sizeof(n) - 4;
748
749 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
750 addrs[i].prefix <= 64)
751 continue;
752
753 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
754 continue;
755
756 memcpy(buf + datalen, &n, sizeof(n));
757 datalen += entrlen + 4;
758 }
759
760 /* Calculate T1 / T2 based on non-deprecated addresses */
761 if (prefix_pref > 0) {
762 if (prefix_pref < pref)
763 pref = prefix_pref;
764
765 if (prefix_valid < valid)
766 valid = prefix_valid;
767 }
768 }
769
770 if (!INFINITE_VALID(a->valid_until))
771 /* UINT32_MAX is considered as infinite leasetime */
772 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
773
774 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
775 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
776
777 if (!out.t1)
778 out.t1 = htonl(1);
779
780 if (!out.t2)
781 out.t2 = htonl(1);
782 }
783
784 if (!request) {
785 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
786 uint16_t otype, olen;
787 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
788 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
789 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
790 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
791 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
792 continue;
793
794 bool found = false;
795 if (a) {
796 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
797 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
798
799 for (size_t i = 0; i < addrlen; ++i) {
800 if (addrs[i].prefix > 96 ||
801 addrs[i].preferred <= (uint32_t)now)
802 continue;
803
804 struct in6_addr addr = addrs[i].addr;
805 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
806 addr.s6_addr32[1] |= htonl(a->assigned);
807
808 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
809 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
810 found = true;
811 } else {
812 addr.s6_addr32[3] = htonl(a->assigned);
813
814 if (!memcmp(&n->addr, &addr, sizeof(addr)))
815 found = true;
816 }
817 }
818 }
819
820 if (!found) {
821 if (otype == DHCPV6_OPT_IA_PREFIX) {
822 struct dhcpv6_ia_prefix inv = {
823 .type = htons(DHCPV6_OPT_IA_PREFIX),
824 .len = htons(sizeof(inv) - 4),
825 .preferred = 0,
826 .valid = 0,
827 .prefix = p->prefix,
828 .addr = p->addr
829 };
830
831 if (datalen + sizeof(inv) > buflen)
832 continue;
833
834 memcpy(buf + datalen, &inv, sizeof(inv));
835 datalen += sizeof(inv);
836 } else {
837 struct dhcpv6_ia_addr inv = {
838 .type = htons(DHCPV6_OPT_IA_ADDR),
839 .len = htons(sizeof(inv) - 4),
840 .addr = n->addr,
841 .preferred = 0,
842 .valid = 0
843 };
844
845 if (datalen + sizeof(inv) > buflen)
846 continue;
847
848 memcpy(buf + datalen, &inv, sizeof(inv));
849 datalen += sizeof(inv);
850 }
851 }
852 }
853 }
854 }
855
856 out.len = htons(datalen - 4);
857 memcpy(buf, &out, sizeof(out));
858 return datalen;
859 }
860
861 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
862 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
863 {
864 const char *type = "UNKNOWN";
865 const char *status = "UNKNOWN";
866
867 if (msgtype == DHCPV6_MSG_RENEW)
868 return;
869
870 switch (msgtype) {
871 case DHCPV6_MSG_SOLICIT:
872 type = "SOLICIT";
873 break;
874 case DHCPV6_MSG_REQUEST:
875 type = "REQUEST";
876 break;
877 case DHCPV6_MSG_CONFIRM:
878 type = "CONFIRM";
879 break;
880 case DHCPV6_MSG_RENEW:
881 type = "RENEW";
882 break;
883 case DHCPV6_MSG_REBIND:
884 type = "REBIND";
885 break;
886 case DHCPV6_MSG_RELEASE:
887 type = "RELEASE";
888 break;
889 case DHCPV6_MSG_DECLINE:
890 type = "DECLINE";
891 break;
892 }
893
894 switch (code) {
895 case DHCPV6_STATUS_OK:
896 status = "ok";
897 break;
898 case DHCPV6_STATUS_NOADDRSAVAIL:
899 status = "no addresses available";
900 break;
901 case DHCPV6_STATUS_NOBINDING:
902 status = "no binding";
903 break;
904 case DHCPV6_STATUS_NOTONLINK:
905 status = "not on-link";
906 break;
907 case DHCPV6_STATUS_NOPREFIXAVAIL:
908 status = "no prefix available";
909 break;
910 }
911
912 char leasebuf[256] = "";
913
914 if (a) {
915 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
916 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
917 size_t lbsize = 0;
918 char addrbuf[INET6_ADDRSTRLEN];
919
920 for (size_t i = 0; i < addrlen; ++i) {
921 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
922 continue;
923
924 struct in6_addr addr = addrs[i].addr;
925 int prefix = a->managed ? addrs[i].prefix : a->length;
926 if (prefix == 128)
927 addr.s6_addr32[3] = htonl(a->assigned);
928 else
929 addr.s6_addr32[1] |= htonl(a->assigned);
930
931 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
932 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
933 }
934 }
935
936 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
937 duidbuf, iface->ifname, status, leasebuf);
938 }
939
940 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
941 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
942 {
943 time_t now = odhcpd_time();
944 size_t response_len = 0;
945 const struct dhcpv6_client_header *hdr = data;
946 uint8_t *start = (uint8_t*)&hdr[1], *odata;
947 uint16_t otype, olen;
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 if (!clid_data || !clid_len || clid_len > 130)
980 goto out;
981
982 struct dhcpv6_assignment *first = NULL;
983 dhcpv6_for_each_option(start, end, otype, olen, odata) {
984 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
985 bool is_na = (otype == DHCPV6_OPT_IA_NA);
986 bool ia_addr_present = false;
987 if (!is_pd && !is_na)
988 continue;
989
990 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
991 size_t ia_response_len = 0;
992 uint8_t reqlen = (is_pd) ? 62 : 128;
993 uint32_t reqhint = 0;
994
995 /* Parse request hint for IA-PD */
996 if (is_pd) {
997 uint8_t *sdata;
998 uint16_t stype, slen;
999 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1000 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1001 continue;
1002
1003 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1004 if (p->prefix) {
1005 reqlen = p->prefix;
1006 reqhint = ntohl(p->addr.s6_addr32[1]);
1007 if (reqlen > 32 && reqlen <= 64)
1008 reqhint &= (1U << (64 - reqlen)) - 1;
1009 }
1010 }
1011
1012 if (reqlen > 64)
1013 reqlen = 64;
1014 } else if (is_na) {
1015 uint8_t *sdata;
1016 uint16_t stype, slen;
1017 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1018 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1019 continue;
1020
1021 ia_addr_present = true;
1022 }
1023 }
1024
1025 /* Find assignment */
1026 struct dhcpv6_assignment *c, *a = NULL;
1027 list_for_each_entry(c, &iface->ia_assignments, head) {
1028 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1029 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1030 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1031 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1032 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1033 a = c;
1034
1035 // Reset state
1036 apply_lease(iface, a, false);
1037 memcpy(a->clid_data, clid_data, clid_len);
1038 a->clid_len = clid_len;
1039 a->iaid = ia->iaid;
1040 a->peer = *addr;
1041 a->reconf_cnt = 0;
1042 a->reconf_sent = 0;
1043 break;
1044 }
1045 }
1046
1047 /* Generic message handling */
1048 uint16_t status = DHCPV6_STATUS_OK;
1049 if (a && a->managed_size < 0)
1050 return -1;
1051
1052 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) {
1056 /* Create new binding */
1057 a = calloc(1, sizeof(*a) + clid_len);
1058 if (a) {
1059 a->clid_len = clid_len;
1060 a->iaid = ia->iaid;
1061 a->length = reqlen;
1062 a->peer = *addr;
1063 a->assigned = reqhint;
1064 /* Set valid time to current time indicating */
1065 /* assignment is not having infinite lifetime */
1066 a->valid_until = now;
1067
1068 if (first)
1069 memcpy(a->key, first->key, sizeof(a->key));
1070 else
1071 odhcpd_urandom(a->key, sizeof(a->key));
1072 memcpy(a->clid_data, clid_data, clid_len);
1073
1074 if (is_pd)
1075 while (!(assigned = assign_pd(iface, a)) &&
1076 !a->managed_size && ++a->length <= 64);
1077 else
1078 assigned = assign_na(iface, a);
1079
1080 if (a->managed_size && !assigned)
1081 return -1;
1082 }
1083 }
1084
1085 if (!assigned || iface->ia_addr_len == 0)
1086 /* Set error status */
1087 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1088 else if (assigned && !first) {
1089 size_t handshake_len = 4;
1090 buf[0] = 0;
1091 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1092 buf[2] = 0;
1093 buf[3] = 0;
1094
1095 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1096 struct dhcpv6_auth_reconfigure auth = {
1097 htons(DHCPV6_OPT_AUTH),
1098 htons(sizeof(auth) - 4),
1099 3, 1, 0,
1100 {htonl(time(NULL)), htonl(++serial)},
1101 1,
1102 {0}
1103 };
1104 memcpy(auth.key, a->key, sizeof(a->key));
1105 memcpy(buf + handshake_len, &auth, sizeof(auth));
1106 handshake_len += sizeof(auth);
1107 }
1108
1109 buf += handshake_len;
1110 buflen -= handshake_len;
1111 response_len += handshake_len;
1112
1113 first = a;
1114 }
1115
1116 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1117
1118 /* Was only a solicitation: mark binding for removal */
1119 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1120 a->flags &= ~OAF_BOUND;
1121
1122 if (!(a->flags & OAF_STATIC))
1123 a->valid_until = now;
1124 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1125 if (hostname_len > 0) {
1126 a->hostname = realloc(a->hostname, hostname_len + 1);
1127 if (a->hostname) {
1128 memcpy(a->hostname, hostname, hostname_len);
1129 a->hostname[hostname_len] = 0;
1130 }
1131 }
1132 a->accept_reconf = accept_reconf;
1133 a->flags |= OAF_BOUND;
1134 apply_lease(iface, a, true);
1135 } else if (!assigned && a && a->managed_size == 0)
1136 /* Cleanup failed assignment */
1137 free_dhcpv6_assignment(a);
1138
1139 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1140 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1141 hdr->msg_type == DHCPV6_MSG_REBIND ||
1142 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1143 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1144 status = DHCPV6_STATUS_NOBINDING;
1145 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1146 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1147 hdr->msg_type == DHCPV6_MSG_REBIND) {
1148 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1149 if (a) {
1150 a->flags |= OAF_BOUND;
1151 apply_lease(iface, a, true);
1152 }
1153 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1154 if (!(a->flags & OAF_STATIC))
1155 a->valid_until = now - 1;
1156
1157 a->flags &= ~OAF_BOUND;
1158 apply_lease(iface, a, false);
1159 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1160 a->flags &= ~OAF_BOUND;
1161
1162 if (!(a->flags & OAF_STATIC)) {
1163 a->clid_len = 0;
1164 a->valid_until = now + 3600; /* Block address for 1h */
1165 }
1166 }
1167 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1168 /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1169 status = DHCPV6_STATUS_NOTONLINK;
1170 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1171 notonlink = true;
1172 }
1173
1174 buf += ia_response_len;
1175 buflen -= ia_response_len;
1176 response_len += ia_response_len;
1177 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1178 }
1179
1180 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1181 response_len + 6 < buflen) {
1182 buf[0] = 0;
1183 buf[1] = DHCPV6_OPT_STATUS;
1184 buf[2] = 0;
1185 buf[3] = 2;
1186 buf[4] = 0;
1187 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1188 response_len += 6;
1189 }
1190
1191 dhcpv6_write_statefile();
1192
1193 out:
1194 return response_len;
1195 }
OpenWrt DHCP Server