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odhcpd: Display infinite valid lifetime as -1
[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 %ld %x %u ",
247 iface->ifname, duidbuf, ntohl(c->iaid),
248 (c->hostname ? c->hostname : "-"),
249 (c->valid_until > now ?
250 (c->valid_until - now + wall_time) :
251 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
252 c->assigned, (unsigned)c->length);
253
254 struct in6_addr addr;
255 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
256 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
257 size_t m = 0;
258
259 for (size_t i = 0; i < addrlen; ++i)
260 if (addrs[i].preferred > addrs[m].preferred ||
261 (addrs[i].preferred == addrs[m].preferred &&
262 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
263 m = i;
264
265 for (size_t i = 0; i < addrlen; ++i) {
266 if (addrs[i].prefix > 96 || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
267 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
268 addrs[i].prefix == 64))
269 continue;
270
271 addr = addrs[i].addr;
272 if (c->length == 128)
273 addr.s6_addr32[3] = htonl(c->assigned);
274 else
275 addr.s6_addr32[1] |= htonl(c->assigned);
276
277 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
278
279 if (c->length == 128 && c->hostname) {
280 fputs(ipbuf, fp);
281
282 char b[256];
283 if (dn_expand(iface->search, iface->search + iface->search_len,
284 iface->search, b, sizeof(b)) > 0)
285 fprintf(fp, "\t%s.%s", c->hostname, b);
286
287 fprintf(fp, "\t%s\n", c->hostname);
288 md5_hash(ipbuf, strlen(ipbuf), &md5);
289 md5_hash(c->hostname, strlen(c->hostname), &md5);
290 }
291
292 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
293 (c->managed_size) ? addrs[i].prefix : c->length);
294 }
295 leasebuf[l - 1] = '\n';
296 fwrite(leasebuf, 1, l, fp);
297 }
298 }
299
300 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
301 struct dhcpv4_assignment *c;
302 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
303 char ipbuf[INET6_ADDRSTRLEN];
304 char leasebuf[512];
305 char duidbuf[16];
306 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
307
308 // iface DUID iaid hostname lifetime assigned length [addrs...]
309 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
310 iface->ifname, duidbuf,
311 (c->hostname ? c->hostname : "-"),
312 (c->valid_until > now ?
313 (c->valid_until - now + wall_time) :
314 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
315 c->addr);
316
317 struct in_addr addr = {htonl(c->addr)};
318 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
319
320 if (c->hostname[0]) {
321 fputs(ipbuf, fp);
322
323 char b[256];
324 if (dn_expand(iface->search, iface->search + iface->search_len,
325 iface->search, b, sizeof(b)) > 0)
326 fprintf(fp, "\t%s.%s", c->hostname, b);
327
328 fprintf(fp, "\t%s\n", c->hostname);
329 md5_hash(ipbuf, strlen(ipbuf), &md5);
330 md5_hash(c->hostname, strlen(c->hostname), &md5);
331 }
332
333 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
334 leasebuf[l - 1] = '\n';
335 fwrite(leasebuf, 1, l, fp);
336 }
337 }
338 }
339
340 fclose(fp);
341 }
342
343 uint8_t newmd5[16];
344 md5_end(newmd5, &md5);
345
346 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
347 memcpy(statemd5, newmd5, sizeof(statemd5));
348 char *argv[2] = {config.dhcp_cb, NULL};
349 if (!vfork()) {
350 execv(argv[0], argv);
351 _exit(128);
352 }
353 }
354 }
355
356
357 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
358 {
359 if (a->length > 64 || a->managed_size < 0)
360 return;
361
362 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
363 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
364
365 for (size_t i = 0; i < addrlen; ++i) {
366 struct in6_addr prefix = addrs[i].addr;
367 prefix.s6_addr32[1] |= htonl(a->assigned);
368 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
369 iface, &a->peer.sin6_addr, 1024, add);
370 }
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
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
491 // Try honoring the hint first
492 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
493 if (assign->assigned) {
494 list_for_each_entry(c, &iface->ia_assignments, head) {
495 if (c->length == 128 || c->length == 0)
496 continue;
497
498 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
499 list_add_tail(&assign->head, &c->head);
500 apply_lease(iface, assign, true);
501 return true;
502 }
503
504 if (c->assigned != 0)
505 current = (c->assigned + (1 << (64 - c->length)));
506 }
507 }
508
509 // Fallback to a variable assignment
510 current = 1;
511 list_for_each_entry(c, &iface->ia_assignments, head) {
512 if (c->length == 128 || c->length == 0)
513 continue;
514
515 current = (current + asize) & (~asize);
516 if (current + asize < c->assigned) {
517 assign->assigned = current;
518 list_add_tail(&assign->head, &c->head);
519 apply_lease(iface, assign, true);
520 return true;
521 }
522
523 if (c->assigned != 0)
524 current = (c->assigned + (1 << (64 - c->length)));
525 }
526
527 return false;
528 }
529
530
531 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
532 {
533 // Seed RNG with checksum of DUID
534 uint32_t seed = 0;
535 for (size_t i = 0; i < assign->clid_len; ++i)
536 seed += assign->clid_data[i];
537 srand(seed);
538
539 // Try to assign up to 100x
540 for (size_t i = 0; i < 100; ++i) {
541 uint32_t try;
542 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
543
544 struct dhcpv6_assignment *c;
545 list_for_each_entry(c, &iface->ia_assignments, head) {
546 if (c->length == 0)
547 continue;
548
549 if (c->assigned > try || c->length != 128) {
550 assign->assigned = try;
551 list_add_tail(&assign->head, &c->head);
552 return true;
553 } else if (c->assigned == try) {
554 break;
555 }
556 }
557 }
558
559 return false;
560 }
561
562 void dhcpv6_ia_preupdate(struct interface *iface)
563 {
564 if (iface->dhcpv6 != RELAYD_SERVER)
565 return;
566
567 struct dhcpv6_assignment *c, *border = list_last_entry(
568 &iface->ia_assignments, struct dhcpv6_assignment, head);
569 list_for_each_entry(c, &iface->ia_assignments, head)
570 if (c != border && !iface->managed)
571 apply_lease(iface, c, false);
572 }
573
574 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
575 {
576 if (iface->dhcpv6 != RELAYD_SERVER)
577 return;
578
579 int minprefix = -1;
580 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
581 if (iface->ia_addr[i].preferred > (uint32_t)now &&
582 iface->ia_addr[i].prefix < 64 &&
583 iface->ia_addr[i].prefix > minprefix)
584 minprefix = iface->ia_addr[i].prefix;
585 }
586
587 struct dhcpv6_assignment *border = list_last_entry(
588 &iface->ia_assignments, struct dhcpv6_assignment, head);
589 if (minprefix > 32 && minprefix <= 64)
590 border->assigned = 1U << (64 - minprefix);
591 else
592 border->assigned = 0;
593
594 struct list_head reassign = LIST_HEAD_INIT(reassign);
595 struct dhcpv6_assignment *c, *d;
596 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
597 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
598 c->managed_size)
599 continue;
600
601 if (c->length < 128 && c->assigned >= border->assigned && c != border)
602 list_move(&c->head, &reassign);
603 else if (c != border)
604 apply_lease(iface, c, true);
605
606 if (c->accept_reconf && c->reconf_cnt == 0) {
607 c->reconf_cnt = 1;
608 c->reconf_sent = now;
609 send_reconf(iface, c);
610
611 // Leave all other assignments of that client alone
612 struct dhcpv6_assignment *a;
613 list_for_each_entry(a, &iface->ia_assignments, head)
614 if (a != c && a->clid_len == c->clid_len &&
615 !memcmp(a->clid_data, c->clid_data, a->clid_len))
616 c->reconf_cnt = INT_MAX;
617 }
618 }
619
620 while (!list_empty(&reassign)) {
621 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
622 list_del(&c->head);
623 if (!assign_pd(iface, c)) {
624 c->assigned = 0;
625 list_add(&c->head, &iface->ia_assignments);
626 }
627 }
628
629 dhcpv6_write_statefile();
630 }
631
632
633 static void reconf_timer(struct uloop_timeout *event)
634 {
635 time_t now = odhcpd_time();
636 struct interface *iface;
637 list_for_each_entry(iface, &interfaces, head) {
638 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
639 continue;
640
641 struct dhcpv6_assignment *a, *n;
642 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
643 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
644 if ((a->length < 128 && a->clid_len > 0) ||
645 (a->length == 128 && a->clid_len == 0)) {
646 list_del(&a->head);
647 free_dhcpv6_assignment(a);
648 }
649 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
650 now > a->reconf_sent + (1 << a->reconf_cnt)) {
651 ++a->reconf_cnt;
652 a->reconf_sent = now;
653 send_reconf(iface, a);
654 }
655 }
656 }
657 uloop_timeout_set(event, 2000);
658 }
659
660
661 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
662 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
663 struct interface *iface, bool request)
664 {
665 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
666 return 0;
667
668 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
669 size_t datalen = sizeof(out);
670 time_t now = odhcpd_time();
671
672 if (status) {
673 struct __attribute__((packed)) {
674 uint16_t type;
675 uint16_t len;
676 uint16_t value;
677 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
678 htons(status)};
679
680 memcpy(buf + datalen, &stat, sizeof(stat));
681 datalen += sizeof(stat);
682 } else {
683 if (a) {
684 uint32_t leasetime;
685 if (a->leasetime > 0) {
686 leasetime = a->leasetime;
687 } else {
688 leasetime = iface->dhcpv4_leasetime;
689 }
690 if (leasetime == 0)
691 leasetime = 3600;
692 else if (leasetime < 60)
693 leasetime = 60;
694
695 uint32_t pref = leasetime;
696 uint32_t valid = leasetime;
697
698 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
699 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
700 size_t m = 0;
701
702 for (size_t i = 0; i < addrlen; ++i)
703 if (addrs[i].preferred > addrs[m].preferred ||
704 (addrs[i].preferred == addrs[m].preferred &&
705 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
706 m = i;
707
708 for (size_t i = 0; i < addrlen; ++i) {
709 uint32_t prefix_pref = addrs[i].preferred;
710 uint32_t prefix_valid = addrs[i].valid;
711
712 if (addrs[i].prefix > 96 ||
713 addrs[i].preferred <= (uint32_t)now)
714 continue;
715
716 if (prefix_pref != UINT32_MAX)
717 prefix_pref -= now;
718
719 if (prefix_valid != UINT32_MAX)
720 prefix_valid -= now;
721
722 if (a->length < 128) {
723 struct dhcpv6_ia_prefix p = {
724 .type = htons(DHCPV6_OPT_IA_PREFIX),
725 .len = htons(sizeof(p) - 4),
726 .preferred = htonl(prefix_pref),
727 .valid = htonl(prefix_valid),
728 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
729 .addr = addrs[i].addr
730 };
731 p.addr.s6_addr32[1] |= htonl(a->assigned);
732
733 size_t entrlen = sizeof(p) - 4;
734
735 if (datalen + entrlen + 4 > buflen ||
736 (a->assigned == 0 && a->managed_size == 0) ||
737 (!a->managed_size && a->length <= addrs[i].prefix))
738 continue;
739
740 memcpy(buf + datalen, &p, sizeof(p));
741 datalen += entrlen + 4;
742 } else {
743 struct dhcpv6_ia_addr n = {
744 .type = htons(DHCPV6_OPT_IA_ADDR),
745 .len = htons(sizeof(n) - 4),
746 .addr = addrs[i].addr,
747 .preferred = htonl(prefix_pref),
748 .valid = htonl(prefix_valid)
749 };
750 n.addr.s6_addr32[3] = htonl(a->assigned);
751 size_t entrlen = sizeof(n) - 4;
752
753 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
754 addrs[i].prefix <= 64)
755 continue;
756
757 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
758 continue;
759
760 memcpy(buf + datalen, &n, sizeof(n));
761 datalen += entrlen + 4;
762 }
763
764 // Calculate T1 / T2 based on non-deprecated addresses
765 if (prefix_pref > 0) {
766 if (prefix_pref < pref)
767 pref = prefix_pref;
768
769 if (prefix_valid < valid)
770 valid = prefix_valid;
771 }
772 }
773
774 /* UINT32_MAX is considered as infinite leasetime */
775 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
776 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
777 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
778
779 if (!out.t1)
780 out.t1 = htonl(1);
781
782 if (!out.t2)
783 out.t2 = htonl(1);
784 }
785
786 if (!request) {
787 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
788 uint16_t otype, olen;
789 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
790 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
791 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
792 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
793 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
794 continue;
795
796 bool found = false;
797 if (a) {
798 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
799 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
800
801 for (size_t i = 0; i < addrlen; ++i) {
802 if (addrs[i].prefix > 96 ||
803 addrs[i].preferred <= (uint32_t)now)
804 continue;
805
806 struct in6_addr addr = addrs[i].addr;
807 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
808 addr.s6_addr32[1] |= htonl(a->assigned);
809
810 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
811 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
812 found = true;
813 } else {
814 addr.s6_addr32[3] = htonl(a->assigned);
815
816 if (!memcmp(&n->addr, &addr, sizeof(addr)))
817 found = true;
818 }
819 }
820 }
821
822 if (!found) {
823 if (otype == DHCPV6_OPT_IA_PREFIX) {
824 struct dhcpv6_ia_prefix inv = {
825 .type = htons(DHCPV6_OPT_IA_PREFIX),
826 .len = htons(sizeof(inv) - 4),
827 .preferred = 0,
828 .valid = 0,
829 .prefix = p->prefix,
830 .addr = p->addr
831 };
832
833 if (datalen + sizeof(inv) > buflen)
834 continue;
835
836 memcpy(buf + datalen, &inv, sizeof(inv));
837 datalen += sizeof(inv);
838 } else {
839 struct dhcpv6_ia_addr inv = {
840 .type = htons(DHCPV6_OPT_IA_ADDR),
841 .len = htons(sizeof(inv) - 4),
842 .addr = n->addr,
843 .preferred = 0,
844 .valid = 0
845 };
846
847 if (datalen + sizeof(inv) > buflen)
848 continue;
849
850 memcpy(buf + datalen, &inv, sizeof(inv));
851 datalen += sizeof(inv);
852 }
853 }
854 }
855 }
856 }
857
858 out.len = htons(datalen - 4);
859 memcpy(buf, &out, sizeof(out));
860 return datalen;
861 }
862
863
864 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
865 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
866 {
867 const char *type = "UNKNOWN";
868 const char *status = "UNKNOWN";
869
870 if (msgtype == DHCPV6_MSG_RENEW)
871 return;
872
873 switch (msgtype) {
874 case DHCPV6_MSG_SOLICIT:
875 type = "SOLICIT";
876 break;
877 case DHCPV6_MSG_REQUEST:
878 type = "REQUEST";
879 break;
880 case DHCPV6_MSG_CONFIRM:
881 type = "CONFIRM";
882 break;
883 case DHCPV6_MSG_RENEW:
884 type = "RENEW";
885 break;
886 case DHCPV6_MSG_REBIND:
887 type = "REBIND";
888 break;
889 case DHCPV6_MSG_RELEASE:
890 type = "RELEASE";
891 break;
892 case DHCPV6_MSG_DECLINE:
893 type = "DECLINE";
894 break;
895 }
896
897 switch (code) {
898 case DHCPV6_STATUS_OK:
899 status = "ok";
900 break;
901 case DHCPV6_STATUS_NOADDRSAVAIL:
902 status = "no addresses available";
903 break;
904 case DHCPV6_STATUS_NOBINDING:
905 status = "no binding";
906 break;
907 case DHCPV6_STATUS_NOTONLINK:
908 status = "not on-link";
909 break;
910 case DHCPV6_STATUS_NOPREFIXAVAIL:
911 status = "no prefix available";
912 break;
913 }
914
915 char leasebuf[256] = "";
916
917 if (a) {
918 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
919 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
920 size_t lbsize = 0;
921 char addrbuf[INET6_ADDRSTRLEN];
922
923 for (size_t i = 0; i < addrlen; ++i) {
924 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
925 continue;
926
927 struct in6_addr addr = addrs[i].addr;
928 int prefix = a->managed ? addrs[i].prefix : a->length;
929 if (prefix == 128)
930 addr.s6_addr32[3] = htonl(a->assigned);
931 else
932 addr.s6_addr32[1] |= htonl(a->assigned);
933
934 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
935 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
936 }
937 }
938
939 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
940 duidbuf, iface->ifname, status, leasebuf);
941 }
942
943
944
945 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
946 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
947 {
948 time_t now = odhcpd_time();
949 size_t response_len = 0;
950 const struct dhcpv6_client_header *hdr = data;
951 uint8_t *start = (uint8_t*)&hdr[1], *odata;
952 uint16_t otype, olen;
953
954 // Find and parse client-id and hostname
955 bool accept_reconf = false;
956 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
957 char hostname[256];
958 size_t hostname_len = 0;
959 bool notonlink = false;
960 char duidbuf[261];
961
962 dhcpv6_for_each_option(start, end, otype, olen, odata) {
963 if (otype == DHCPV6_OPT_CLIENTID) {
964 clid_data = odata;
965 clid_len = olen;
966
967 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
968 memcpy(mac, &odata[8], sizeof(mac));
969 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
970 memcpy(mac, &odata[4], sizeof(mac));
971
972 if (olen <= 130)
973 odhcpd_hexlify(duidbuf, odata, olen);
974 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
975 uint8_t fqdn_buf[256];
976 memcpy(fqdn_buf, odata, olen);
977 fqdn_buf[olen++] = 0;
978
979 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
980 hostname_len = strcspn(hostname, ".");
981 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
982 accept_reconf = true;
983 }
984 }
985
986 if (!clid_data || !clid_len || clid_len > 130)
987 goto out;
988
989 struct dhcpv6_assignment *first = NULL;
990 dhcpv6_for_each_option(start, end, otype, olen, odata) {
991 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
992 bool is_na = (otype == DHCPV6_OPT_IA_NA);
993 bool ia_addr_present = false;
994 if (!is_pd && !is_na)
995 continue;
996
997 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
998 size_t ia_response_len = 0;
999 uint8_t reqlen = (is_pd) ? 62 : 128;
1000 uint32_t reqhint = 0;
1001
1002 // Parse request hint for IA-PD
1003 if (is_pd) {
1004 uint8_t *sdata;
1005 uint16_t stype, slen;
1006 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1007 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1008 continue;
1009
1010 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1011 if (p->prefix) {
1012 reqlen = p->prefix;
1013 reqhint = ntohl(p->addr.s6_addr32[1]);
1014 if (reqlen > 32 && reqlen <= 64)
1015 reqhint &= (1U << (64 - reqlen)) - 1;
1016 }
1017 }
1018
1019 if (reqlen > 64)
1020 reqlen = 64;
1021 } else if (is_na) {
1022 uint8_t *sdata;
1023 uint16_t stype, slen;
1024 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1025 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1026 continue;
1027
1028 ia_addr_present = true;
1029 }
1030 }
1031
1032 // Find assignment
1033 struct dhcpv6_assignment *c, *a = NULL;
1034 list_for_each_entry(c, &iface->ia_assignments, head) {
1035 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1036 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1037 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1038 (c->iaid == ia->iaid || (!INFINITE_VALID(c->valid_until) && c->valid_until < now)) &&
1039 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1040 a = c;
1041
1042 // Reset state
1043 apply_lease(iface, a, false);
1044 memcpy(a->clid_data, clid_data, clid_len);
1045 a->clid_len = clid_len;
1046 a->iaid = ia->iaid;
1047 a->peer = *addr;
1048 a->reconf_cnt = 0;
1049 a->reconf_sent = 0;
1050 break;
1051 }
1052 }
1053
1054 // Generic message handling
1055 uint16_t status = DHCPV6_STATUS_OK;
1056 if (a && a->managed_size < 0) {
1057 return -1;
1058 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1059 bool assigned = !!a;
1060
1061 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1062 a = calloc(1, sizeof(*a) + clid_len);
1063 if (a) {
1064 a->clid_len = clid_len;
1065 a->iaid = ia->iaid;
1066 a->length = reqlen;
1067 a->peer = *addr;
1068 a->assigned = reqhint;
1069
1070 if (first)
1071 memcpy(a->key, first->key, sizeof(a->key));
1072 else
1073 odhcpd_urandom(a->key, sizeof(a->key));
1074 memcpy(a->clid_data, clid_data, clid_len);
1075
1076 if (is_pd)
1077 while (!(assigned = assign_pd(iface, a)) &&
1078 !a->managed_size && ++a->length <= 64);
1079 else
1080 assigned = assign_na(iface, a);
1081
1082 if (a->managed_size && !assigned)
1083 return -1;
1084 }
1085 }
1086
1087 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1088 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1089 } else if (assigned && !first) { //
1090 size_t handshake_len = 4;
1091 buf[0] = 0;
1092 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1093 buf[2] = 0;
1094 buf[3] = 0;
1095
1096 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1097 struct dhcpv6_auth_reconfigure auth = {
1098 htons(DHCPV6_OPT_AUTH),
1099 htons(sizeof(auth) - 4),
1100 3, 1, 0,
1101 {htonl(time(NULL)), htonl(++serial)},
1102 1,
1103 {0}
1104 };
1105 memcpy(auth.key, a->key, sizeof(a->key));
1106 memcpy(buf + handshake_len, &auth, sizeof(auth));
1107 handshake_len += sizeof(auth);
1108 }
1109
1110 buf += handshake_len;
1111 buflen -= handshake_len;
1112 response_len += handshake_len;
1113
1114 first = a;
1115 }
1116
1117 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1118
1119 // Was only a solicitation: mark binding for removal
1120 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1121 a->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 apply_lease(iface, a, true);
1132 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1133 free_dhcpv6_assignment(a);
1134 }
1135 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1136 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1137 hdr->msg_type == DHCPV6_MSG_REBIND ||
1138 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1139 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1140 status = DHCPV6_STATUS_NOBINDING;
1141 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1142 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1143 hdr->msg_type == DHCPV6_MSG_REBIND) {
1144 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1145 if (a)
1146 apply_lease(iface, a, true);
1147 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1148 a->valid_until = now - 1;
1149 apply_lease(iface, a, false);
1150 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1151 a->clid_len = 0;
1152 a->valid_until = now + 3600; // Block address for 1h
1153 }
1154 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1155 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1156 status = DHCPV6_STATUS_NOTONLINK;
1157 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1158 notonlink = true;
1159 }
1160
1161 buf += ia_response_len;
1162 buflen -= ia_response_len;
1163 response_len += ia_response_len;
1164 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1165 }
1166
1167 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1168 response_len + 6 < buflen) {
1169 buf[0] = 0;
1170 buf[1] = DHCPV6_OPT_STATUS;
1171 buf[2] = 0;
1172 buf[3] = 2;
1173 buf[4] = 0;
1174 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1175 response_len += 6;
1176 }
1177
1178 dhcpv6_write_statefile();
1179
1180 out:
1181 return response_len;
1182 }
OpenWrt DHCP Server