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Add per-host leasetime support
[project/odhcpd.git] / src / dhcpv6-ia.c
1 /**
2 * Copyright (C) 2013 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include "odhcpd.h"
16 #include "dhcpv6.h"
17 #include "dhcpv4.h"
18 #include "libubox/md5.h"
19 #include "libubox/usock.h"
20
21 #include <time.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <poll.h>
26 #include <alloca.h>
27 #include <resolv.h>
28 #include <limits.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 #include <stdbool.h>
33 #include <arpa/inet.h>
34 #include <sys/timerfd.h>
35
36
37 static void reconf_timer(struct uloop_timeout *event);
38 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
39 static uint32_t serial = 0;
40 static uint8_t statemd5[16];
41
42
43 int dhcpv6_ia_init(void)
44 {
45 uloop_timeout_set(&reconf_event, 2000);
46 return 0;
47 }
48
49
50 void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
51 {
52 if (c->managed_sock.fd.registered) {
53 ustream_free(&c->managed_sock.stream);
54 close(c->managed_sock.fd.fd);
55 }
56
57 if (c->head.next)
58 list_del(&c->head);
59
60 free(c->managed);
61 free(c->hostname);
62 free(c);
63 }
64
65
66 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
67 {
68 if (!enable && iface->ia_assignments.next) {
69 struct dhcpv6_assignment *c;
70 while (!list_empty(&iface->ia_assignments)) {
71 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
72 free_dhcpv6_assignment(c);
73 }
74 }
75
76 if (enable && iface->dhcpv6 == RELAYD_SERVER) {
77 if (!iface->ia_assignments.next)
78 INIT_LIST_HEAD(&iface->ia_assignments);
79
80 if (list_empty(&iface->ia_assignments)) {
81 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
82 if (!border) {
83 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
84 return -1;
85 }
86
87 border->length = 64;
88 list_add(&border->head, &iface->ia_assignments);
89 }
90
91 // Parse static entries
92 struct lease *lease;
93 list_for_each_entry(lease, &leases, head) {
94 // Construct entry
95 size_t duid_len = lease->duid_len ? lease->duid_len : 14;
96 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
97 if (!a) {
98 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
99 iface->ifname);
100 return -1;
101 }
102
103 if (lease->dhcpv4_leasetime > 0)
104 a->leasetime = lease->dhcpv4_leasetime;
105
106 a->clid_len = duid_len;
107 a->length = 128;
108 if (lease->hostid) {
109 a->assigned = lease->hostid;
110 } else {
111 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
112 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
113 }
114 odhcpd_urandom(a->key, sizeof(a->key));
115 memcpy(a->clid_data, lease->duid, lease->duid_len);
116 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
117
118 // Assign to all interfaces
119 struct dhcpv6_assignment *c;
120 list_for_each_entry(c, &iface->ia_assignments, head) {
121 if (c->length != 128 || c->assigned > a->assigned) {
122 list_add_tail(&a->head, &c->head);
123 break;
124 } else if (c->assigned == a->assigned) {
125 // Already an assignment with that number
126 break;
127 }
128 }
129
130 if (a->head.next) {
131 if (lease->hostname[0]) {
132 free(a->hostname);
133 a->hostname = strdup(lease->hostname);
134 }
135 } else {
136 free(a->hostname);
137 free(a);
138 }
139 }
140 }
141 return 0;
142 }
143
144
145 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
146 {
147 struct {
148 struct dhcpv6_client_header hdr;
149 uint16_t srvid_type;
150 uint16_t srvid_len;
151 uint16_t duid_type;
152 uint16_t hardware_type;
153 uint8_t mac[6];
154 uint16_t msg_type;
155 uint16_t msg_len;
156 uint8_t msg_id;
157 struct dhcpv6_auth_reconfigure auth;
158 uint16_t clid_type;
159 uint16_t clid_len;
160 uint8_t clid_data[128];
161 } __attribute__((packed)) reconf_msg = {
162 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
163 .srvid_type = htons(DHCPV6_OPT_SERVERID),
164 .srvid_len = htons(10),
165 .duid_type = htons(3),
166 .hardware_type = htons(1),
167 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
168 .msg_len = htons(1),
169 .msg_id = DHCPV6_MSG_RENEW,
170 .auth = {htons(DHCPV6_OPT_AUTH),
171 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
172 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
173 .clid_type = htons(DHCPV6_OPT_CLIENTID),
174 .clid_len = htons(assign->clid_len),
175 .clid_data = {0},
176 };
177
178 odhcpd_get_mac(iface, reconf_msg.mac);
179 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
180 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
181
182 md5_ctx_t md5;
183 uint8_t secretbytes[64];
184 memset(secretbytes, 0, sizeof(secretbytes));
185 memcpy(secretbytes, assign->key, sizeof(assign->key));
186
187 for (size_t i = 0; i < sizeof(secretbytes); ++i)
188 secretbytes[i] ^= 0x36;
189
190 md5_begin(&md5);
191 md5_hash(secretbytes, sizeof(secretbytes), &md5);
192 md5_hash(iov.iov_base, iov.iov_len, &md5);
193 md5_end(reconf_msg.auth.key, &md5);
194
195 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
196 secretbytes[i] ^= 0x36;
197 secretbytes[i] ^= 0x5c;
198 }
199
200 md5_begin(&md5);
201 md5_hash(secretbytes, sizeof(secretbytes), &md5);
202 md5_hash(reconf_msg.auth.key, 16, &md5);
203 md5_end(reconf_msg.auth.key, &md5);
204
205 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
206 }
207
208
209 void dhcpv6_write_statefile(void)
210 {
211 md5_ctx_t md5;
212 md5_begin(&md5);
213
214 if (config.dhcp_statefile) {
215 time_t now = odhcpd_time(), wall_time = time(NULL);
216 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
217 if (fd < 0)
218 return;
219
220 lockf(fd, F_LOCK, 0);
221 if (ftruncate(fd, 0) < 0) {}
222
223 FILE *fp = fdopen(fd, "w");
224 if (!fp) {
225 close(fd);
226 return;
227 }
228
229 struct interface *iface;
230 list_for_each_entry(iface, &interfaces, head) {
231 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
232 continue;
233
234 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
235 struct dhcpv6_assignment *c;
236 list_for_each_entry(c, &iface->ia_assignments, head) {
237 if (c->clid_len == 0 || c->managed_size < 0)
238 continue;
239
240 char ipbuf[INET6_ADDRSTRLEN];
241 char leasebuf[512];
242 char duidbuf[264];
243 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
244
245 // iface DUID iaid hostname lifetime assigned length [addrs...]
246 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
247 iface->ifname, duidbuf, ntohl(c->iaid),
248 (c->hostname ? c->hostname : "-"),
249 (unsigned)(c->valid_until > now ?
250 (c->valid_until - now + wall_time) : 0),
251 c->assigned, (unsigned)c->length);
252
253 struct in6_addr addr;
254 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
255 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
256 size_t m = 0;
257
258 for (size_t i = 0; i < addrlen; ++i)
259 if (addrs[i].preferred > addrs[m].preferred ||
260 (addrs[i].preferred == addrs[m].preferred &&
261 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
262 m = i;
263
264 for (size_t i = 0; i < addrlen; ++i) {
265 if (addrs[i].prefix > 96 || c->valid_until <= now ||
266 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
267 addrs[i].prefix == 64))
268 continue;
269
270 addr = addrs[i].addr;
271 if (c->length == 128)
272 addr.s6_addr32[3] = htonl(c->assigned);
273 else
274 addr.s6_addr32[1] |= htonl(c->assigned);
275
276 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
277
278 if (c->length == 128 && c->hostname) {
279 fputs(ipbuf, fp);
280
281 char b[256];
282 if (dn_expand(iface->search, iface->search + iface->search_len,
283 iface->search, b, sizeof(b)) > 0)
284 fprintf(fp, "\t%s.%s", c->hostname, b);
285
286 fprintf(fp, "\t%s\n", c->hostname);
287 md5_hash(ipbuf, strlen(ipbuf), &md5);
288 md5_hash(c->hostname, strlen(c->hostname), &md5);
289 }
290
291 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
292 (c->managed_size) ? addrs[i].prefix : c->length);
293 }
294 leasebuf[l - 1] = '\n';
295 fwrite(leasebuf, 1, l, fp);
296 }
297 }
298
299 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
300 struct dhcpv4_assignment *c;
301 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
302 char ipbuf[INET6_ADDRSTRLEN];
303 char leasebuf[512];
304 char duidbuf[16];
305 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
306
307 // iface DUID iaid hostname lifetime assigned length [addrs...]
308 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
309 iface->ifname, duidbuf,
310 (c->hostname ? c->hostname : "-"),
311 (unsigned)(c->valid_until > now ?
312 (c->valid_until - now + wall_time) : 0),
313 c->addr);
314
315 struct in_addr addr = {htonl(c->addr)};
316 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
317
318 if (c->hostname[0]) {
319 fputs(ipbuf, fp);
320
321 char b[256];
322 if (dn_expand(iface->search, iface->search + iface->search_len,
323 iface->search, b, sizeof(b)) > 0)
324 fprintf(fp, "\t%s.%s", c->hostname, b);
325
326 fprintf(fp, "\t%s\n", c->hostname);
327 md5_hash(ipbuf, strlen(ipbuf), &md5);
328 md5_hash(c->hostname, strlen(c->hostname), &md5);
329 }
330
331 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
332 leasebuf[l - 1] = '\n';
333 fwrite(leasebuf, 1, l, fp);
334 }
335 }
336 }
337
338 fclose(fp);
339 }
340
341 uint8_t newmd5[16];
342 md5_end(newmd5, &md5);
343
344 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
345 memcpy(statemd5, newmd5, sizeof(statemd5));
346 char *argv[2] = {config.dhcp_cb, NULL};
347 if (!vfork()) {
348 execv(argv[0], argv);
349 _exit(128);
350 }
351 }
352 }
353
354
355 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
356 {
357 if (a->length > 64 || a->managed_size < 0)
358 return;
359
360 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
361 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
362
363 for (size_t i = 0; i < addrlen; ++i) {
364 struct in6_addr prefix = addrs[i].addr;
365 prefix.s6_addr32[1] |= htonl(a->assigned);
366 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
367 iface, &a->peer.sin6_addr, 1024, add);
368 }
369 }
370
371
372 // More data was received from TCP connection
373 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
374 {
375 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
376 time_t now = odhcpd_time();
377 bool first = c->managed_size < 0;
378
379 for (;;) {
380 int pending;
381 char *data = ustream_get_read_buf(s, &pending);
382 char *end = memmem(data, pending, "\n\n", 2);
383
384 if (!end)
385 break;
386
387 end += 2;
388 end[-1] = 0;
389
390 c->managed_size = 0;
391 if (c->accept_reconf)
392 c->reconf_cnt = 1;
393
394 char *saveptr;
395 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
396 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
397 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
398
399 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
400 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
401 continue;
402
403 x = strtok_r(NULL, ",", &saveptr2);
404 if (sscanf(x, "%hhu", &n->prefix) < 1)
405 continue;
406
407 x = strtok_r(NULL, ",", &saveptr2);
408 if (sscanf(x, "%u", &n->preferred) < 1)
409 continue;
410
411 x = strtok_r(NULL, ",", &saveptr2);
412 if (sscanf(x, "%u", &n->valid) < 1)
413 continue;
414
415 if (n->preferred > n->valid)
416 continue;
417
418 if (UINT32_MAX - now < n->preferred)
419 n->preferred = UINT32_MAX;
420 else
421 n->preferred += now;
422
423 if (UINT32_MAX - now < n->valid)
424 n->valid = UINT32_MAX;
425 else
426 n->valid += now;
427
428 n->dprefix = 0;
429
430 ++c->managed_size;
431 }
432
433 ustream_consume(s, end - data);
434 }
435
436 if (first && c->managed_size == 0)
437 free_dhcpv6_assignment(c);
438 else if (first)
439 c->valid_until = now + 150;
440 }
441
442
443 // TCP transmission has ended, either because of success or timeout or other error
444 static void managed_handle_pd_done(struct ustream *s)
445 {
446 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
447 c->valid_until = odhcpd_time() + 15;
448 c->managed_size = 0;
449 if (c->accept_reconf)
450 c->reconf_cnt = 1;
451 }
452
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
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
557 return false;
558 }
559
560 void dhcpv6_ia_preupdate(struct interface *iface)
561 {
562 if (iface->dhcpv6 != RELAYD_SERVER)
563 return;
564
565 struct dhcpv6_assignment *c, *border = list_last_entry(
566 &iface->ia_assignments, struct dhcpv6_assignment, head);
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 if (minprefix > 32 && minprefix <= 64)
588 border->assigned = 1U << (64 - minprefix);
589 else
590 border->assigned = 0;
591
592 struct list_head reassign = LIST_HEAD_INIT(reassign);
593 struct dhcpv6_assignment *c, *d;
594 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
595 if (c->clid_len == 0 || c->valid_until < now || 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
630 static void reconf_timer(struct uloop_timeout *event)
631 {
632 time_t now = odhcpd_time();
633 struct interface *iface;
634 list_for_each_entry(iface, &interfaces, head) {
635 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
636 continue;
637
638 struct dhcpv6_assignment *a, *n;
639 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
640 if (a->valid_until < now) {
641 if ((a->length < 128 && a->clid_len > 0) ||
642 (a->length == 128 && a->clid_len == 0)) {
643 list_del(&a->head);
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
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 a->valid_until = valid + now;
772 out.t1 = htonl(pref * 5 / 10);
773 out.t2 = htonl(pref * 8 / 10);
774
775 if (!out.t1)
776 out.t1 = htonl(1);
777
778 if (!out.t2)
779 out.t2 = htonl(1);
780 }
781
782 if (!request) {
783 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
784 uint16_t otype, olen;
785 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
786 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
787 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
788 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
789 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
790 continue;
791
792 bool found = false;
793 if (a) {
794 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
795 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
796
797 for (size_t i = 0; i < addrlen; ++i) {
798 if (addrs[i].prefix > 96 ||
799 addrs[i].preferred <= (uint32_t)now)
800 continue;
801
802 struct in6_addr addr = addrs[i].addr;
803 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
804 addr.s6_addr32[1] |= htonl(a->assigned);
805
806 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
807 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
808 found = true;
809 } else {
810 addr.s6_addr32[3] = htonl(a->assigned);
811
812 if (!memcmp(&n->addr, &addr, sizeof(addr)))
813 found = true;
814 }
815 }
816 }
817
818 if (!found) {
819 if (otype == DHCPV6_OPT_IA_PREFIX) {
820 struct dhcpv6_ia_prefix inv = {
821 .type = htons(DHCPV6_OPT_IA_PREFIX),
822 .len = htons(sizeof(inv) - 4),
823 .preferred = 0,
824 .valid = 0,
825 .prefix = p->prefix,
826 .addr = p->addr
827 };
828
829 if (datalen + sizeof(inv) > buflen)
830 continue;
831
832 memcpy(buf + datalen, &inv, sizeof(inv));
833 datalen += sizeof(inv);
834 } else {
835 struct dhcpv6_ia_addr inv = {
836 .type = htons(DHCPV6_OPT_IA_ADDR),
837 .len = htons(sizeof(inv) - 4),
838 .addr = n->addr,
839 .preferred = 0,
840 .valid = 0
841 };
842
843 if (datalen + sizeof(inv) > buflen)
844 continue;
845
846 memcpy(buf + datalen, &inv, sizeof(inv));
847 datalen += sizeof(inv);
848 }
849 }
850 }
851 }
852 }
853
854 out.len = htons(datalen - 4);
855 memcpy(buf, &out, sizeof(out));
856 return datalen;
857 }
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
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
950 // Find and parse client-id and hostname
951 bool accept_reconf = false;
952 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
953 char hostname[256];
954 size_t hostname_len = 0;
955 bool notonlink = false;
956 char duidbuf[261];
957
958 dhcpv6_for_each_option(start, end, otype, olen, odata) {
959 if (otype == DHCPV6_OPT_CLIENTID) {
960 clid_data = odata;
961 clid_len = olen;
962
963 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
964 memcpy(mac, &odata[8], sizeof(mac));
965 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
966 memcpy(mac, &odata[4], sizeof(mac));
967
968 if (olen <= 130)
969 odhcpd_hexlify(duidbuf, odata, olen);
970 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
971 uint8_t fqdn_buf[256];
972 memcpy(fqdn_buf, odata, olen);
973 fqdn_buf[olen++] = 0;
974
975 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
976 hostname_len = strcspn(hostname, ".");
977 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
978 accept_reconf = true;
979 }
980 }
981
982 if (!clid_data || !clid_len || clid_len > 130)
983 goto out;
984
985 struct dhcpv6_assignment *first = NULL;
986 dhcpv6_for_each_option(start, end, otype, olen, odata) {
987 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
988 bool is_na = (otype == DHCPV6_OPT_IA_NA);
989 bool ia_addr_present = false;
990 if (!is_pd && !is_na)
991 continue;
992
993 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
994 size_t ia_response_len = 0;
995 uint8_t reqlen = (is_pd) ? 62 : 128;
996 uint32_t reqhint = 0;
997
998 // Parse request hint for IA-PD
999 if (is_pd) {
1000 uint8_t *sdata;
1001 uint16_t stype, slen;
1002 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1003 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1004 continue;
1005
1006 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1007 if (p->prefix) {
1008 reqlen = p->prefix;
1009 reqhint = ntohl(p->addr.s6_addr32[1]);
1010 if (reqlen > 32 && reqlen <= 64)
1011 reqhint &= (1U << (64 - reqlen)) - 1;
1012 }
1013 }
1014
1015 if (reqlen > 64)
1016 reqlen = 64;
1017 } else if (is_na) {
1018 uint8_t *sdata;
1019 uint16_t stype, slen;
1020 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1021 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1022 continue;
1023
1024 ia_addr_present = true;
1025 }
1026 }
1027
1028 // Find assignment
1029 struct dhcpv6_assignment *c, *a = NULL;
1030 list_for_each_entry(c, &iface->ia_assignments, head) {
1031 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1032 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1033 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1034 (c->iaid == ia->iaid || c->valid_until < now) &&
1035 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1036 a = c;
1037
1038 // Reset state
1039 apply_lease(iface, a, false);
1040 memcpy(a->clid_data, clid_data, clid_len);
1041 a->clid_len = clid_len;
1042 a->iaid = ia->iaid;
1043 a->peer = *addr;
1044 a->reconf_cnt = 0;
1045 a->reconf_sent = 0;
1046 break;
1047 }
1048 }
1049
1050 // Generic message handling
1051 uint16_t status = DHCPV6_STATUS_OK;
1052 if (a && a->managed_size < 0) {
1053 return -1;
1054 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1055 bool assigned = !!a;
1056
1057 if (!a && !iface->no_dynamic_dhcp) { // 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
1066 if (first)
1067 memcpy(a->key, first->key, sizeof(a->key));
1068 else
1069 odhcpd_urandom(a->key, sizeof(a->key));
1070 memcpy(a->clid_data, clid_data, clid_len);
1071
1072 if (is_pd)
1073 while (!(assigned = assign_pd(iface, a)) &&
1074 !a->managed_size && ++a->length <= 64);
1075 else
1076 assigned = assign_na(iface, a);
1077
1078 if (a->managed_size && !assigned)
1079 return -1;
1080 }
1081 }
1082
1083 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1084 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1085 } else if (assigned && !first) { //
1086 size_t handshake_len = 4;
1087 buf[0] = 0;
1088 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1089 buf[2] = 0;
1090 buf[3] = 0;
1091
1092 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1093 struct dhcpv6_auth_reconfigure auth = {
1094 htons(DHCPV6_OPT_AUTH),
1095 htons(sizeof(auth) - 4),
1096 3, 1, 0,
1097 {htonl(time(NULL)), htonl(++serial)},
1098 1,
1099 {0}
1100 };
1101 memcpy(auth.key, a->key, sizeof(a->key));
1102 memcpy(buf + handshake_len, &auth, sizeof(auth));
1103 handshake_len += sizeof(auth);
1104 }
1105
1106 buf += handshake_len;
1107 buflen -= handshake_len;
1108 response_len += handshake_len;
1109
1110 first = a;
1111 }
1112
1113 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1114
1115 // Was only a solicitation: mark binding for removal
1116 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1117 a->valid_until = 0;
1118 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1119 if (hostname_len > 0) {
1120 a->hostname = realloc(a->hostname, hostname_len + 1);
1121 if (a->hostname) {
1122 memcpy(a->hostname, hostname, hostname_len);
1123 a->hostname[hostname_len] = 0;
1124 }
1125 }
1126 a->accept_reconf = accept_reconf;
1127 apply_lease(iface, a, true);
1128 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1129 free_dhcpv6_assignment(a);
1130 }
1131 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1132 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1133 hdr->msg_type == DHCPV6_MSG_REBIND ||
1134 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1135 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1136 status = DHCPV6_STATUS_NOBINDING;
1137 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1138 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1139 hdr->msg_type == DHCPV6_MSG_REBIND) {
1140 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1141 if (a)
1142 apply_lease(iface, a, true);
1143 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1144 a->valid_until = 0;
1145 apply_lease(iface, a, false);
1146 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1147 a->clid_len = 0;
1148 a->valid_until = now + 3600; // Block address for 1h
1149 }
1150 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1151 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1152 status = DHCPV6_STATUS_NOTONLINK;
1153 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1154 notonlink = true;
1155 }
1156
1157 buf += ia_response_len;
1158 buflen -= ia_response_len;
1159 response_len += ia_response_len;
1160 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1161 }
1162
1163 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1164 response_len + 6 < buflen) {
1165 buf[0] = 0;
1166 buf[1] = DHCPV6_OPT_STATUS;
1167 buf[2] = 0;
1168 buf[3] = 2;
1169 buf[4] = 0;
1170 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1171 response_len += 6;
1172 }
1173
1174 dhcpv6_write_statefile();
1175
1176 out:
1177 return response_len;
1178 }
OpenWrt DHCP Server