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dhcpv4: fix DHCPv4 hostname handling
[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
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
44 int dhcpv6_ia_init(void)
45 {
46 uloop_timeout_set(&reconf_event, 2000);
47 return 0;
48 }
49
50
51 void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
52 {
53 if (c->managed_sock.fd.registered) {
54 ustream_free(&c->managed_sock.stream);
55 close(c->managed_sock.fd.fd);
56 }
57
58 if (c->head.next)
59 list_del(&c->head);
60
61 free(c->managed);
62 free(c->hostname);
63 free(c);
64 }
65
66
67 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
68 {
69 if (!enable && iface->ia_assignments.next) {
70 struct dhcpv6_assignment *c;
71 while (!list_empty(&iface->ia_assignments)) {
72 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
73 free_dhcpv6_assignment(c);
74 }
75 }
76
77 if (enable && iface->dhcpv6 == RELAYD_SERVER) {
78 if (!iface->ia_assignments.next)
79 INIT_LIST_HEAD(&iface->ia_assignments);
80
81 if (list_empty(&iface->ia_assignments)) {
82 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
83 if (!border) {
84 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
85 return -1;
86 }
87
88 border->length = 64;
89 list_add(&border->head, &iface->ia_assignments);
90 }
91
92 // Parse static entries
93 struct lease *lease;
94 list_for_each_entry(lease, &leases, head) {
95 // Construct entry
96 size_t duid_len = lease->duid_len ? lease->duid_len : 14;
97 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
98 if (!a) {
99 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
100 iface->ifname);
101 return -1;
102 }
103
104 if (lease->dhcpv4_leasetime > 0)
105 a->leasetime = lease->dhcpv4_leasetime;
106
107 a->clid_len = duid_len;
108 a->length = 128;
109 if (lease->hostid) {
110 a->assigned = lease->hostid;
111 } else {
112 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
113 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
114 }
115 odhcpd_urandom(a->key, sizeof(a->key));
116 memcpy(a->clid_data, lease->duid, lease->duid_len);
117 memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
118 /* Static assignment */
119 a->flags |= OAF_STATIC;
120 /* Infinite valid */
121 a->valid_until = 0;
122
123 // Assign to all interfaces
124 struct dhcpv6_assignment *c;
125 list_for_each_entry(c, &iface->ia_assignments, head) {
126 if (c->length != 128 || c->assigned > a->assigned) {
127 list_add_tail(&a->head, &c->head);
128 break;
129 } else if (c->assigned == a->assigned) {
130 // Already an assignment with that number
131 break;
132 }
133 }
134
135 if (a->head.next) {
136 if (lease->hostname[0]) {
137 free(a->hostname);
138 a->hostname = strdup(lease->hostname);
139 }
140 } else {
141 free(a->hostname);
142 free(a);
143 }
144 }
145 }
146 return 0;
147 }
148
149
150 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
151 {
152 struct {
153 struct dhcpv6_client_header hdr;
154 uint16_t srvid_type;
155 uint16_t srvid_len;
156 uint16_t duid_type;
157 uint16_t hardware_type;
158 uint8_t mac[6];
159 uint16_t msg_type;
160 uint16_t msg_len;
161 uint8_t msg_id;
162 struct dhcpv6_auth_reconfigure auth;
163 uint16_t clid_type;
164 uint16_t clid_len;
165 uint8_t clid_data[128];
166 } __attribute__((packed)) reconf_msg = {
167 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
168 .srvid_type = htons(DHCPV6_OPT_SERVERID),
169 .srvid_len = htons(10),
170 .duid_type = htons(3),
171 .hardware_type = htons(1),
172 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
173 .msg_len = htons(1),
174 .msg_id = DHCPV6_MSG_RENEW,
175 .auth = {htons(DHCPV6_OPT_AUTH),
176 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
177 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
178 .clid_type = htons(DHCPV6_OPT_CLIENTID),
179 .clid_len = htons(assign->clid_len),
180 .clid_data = {0},
181 };
182
183 odhcpd_get_mac(iface, reconf_msg.mac);
184 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
185 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
186
187 md5_ctx_t md5;
188 uint8_t secretbytes[64];
189 memset(secretbytes, 0, sizeof(secretbytes));
190 memcpy(secretbytes, assign->key, sizeof(assign->key));
191
192 for (size_t i = 0; i < sizeof(secretbytes); ++i)
193 secretbytes[i] ^= 0x36;
194
195 md5_begin(&md5);
196 md5_hash(secretbytes, sizeof(secretbytes), &md5);
197 md5_hash(iov.iov_base, iov.iov_len, &md5);
198 md5_end(reconf_msg.auth.key, &md5);
199
200 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
201 secretbytes[i] ^= 0x36;
202 secretbytes[i] ^= 0x5c;
203 }
204
205 md5_begin(&md5);
206 md5_hash(secretbytes, sizeof(secretbytes), &md5);
207 md5_hash(reconf_msg.auth.key, 16, &md5);
208 md5_end(reconf_msg.auth.key, &md5);
209
210 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
211 }
212
213
214 void dhcpv6_write_statefile(void)
215 {
216 md5_ctx_t md5;
217 md5_begin(&md5);
218
219 if (config.dhcp_statefile) {
220 time_t now = odhcpd_time(), wall_time = time(NULL);
221 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
222 if (fd < 0)
223 return;
224
225 lockf(fd, F_LOCK, 0);
226 if (ftruncate(fd, 0) < 0) {}
227
228 FILE *fp = fdopen(fd, "w");
229 if (!fp) {
230 close(fd);
231 return;
232 }
233
234 struct interface *iface;
235 list_for_each_entry(iface, &interfaces, head) {
236 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
237 continue;
238
239 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
240 struct dhcpv6_assignment *c;
241 list_for_each_entry(c, &iface->ia_assignments, head) {
242 if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
243 continue;
244
245 char ipbuf[INET6_ADDRSTRLEN];
246 char leasebuf[512];
247 char duidbuf[264];
248 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
249
250 // iface DUID iaid hostname lifetime assigned length [addrs...]
251 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
252 iface->ifname, duidbuf, ntohl(c->iaid),
253 (c->hostname ? c->hostname : "-"),
254 (c->valid_until > now ?
255 (c->valid_until - now + wall_time) :
256 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
257 c->assigned, (unsigned)c->length);
258
259 struct in6_addr addr;
260 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
261 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
262 size_t m = 0;
263
264 for (size_t i = 0; i < addrlen; ++i)
265 if (addrs[i].preferred > addrs[m].preferred ||
266 (addrs[i].preferred == addrs[m].preferred &&
267 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
268 m = i;
269
270 for (size_t i = 0; i < addrlen; ++i) {
271 if (addrs[i].prefix > 96 || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
272 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
273 addrs[i].prefix == 64))
274 continue;
275
276 addr = addrs[i].addr;
277 if (c->length == 128)
278 addr.s6_addr32[3] = htonl(c->assigned);
279 else
280 addr.s6_addr32[1] |= htonl(c->assigned);
281
282 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
283
284 if (c->length == 128 && c->hostname) {
285 fputs(ipbuf, fp);
286
287 char b[256];
288 if (dn_expand(iface->search, iface->search + iface->search_len,
289 iface->search, b, sizeof(b)) > 0)
290 fprintf(fp, "\t%s.%s", c->hostname, b);
291
292 fprintf(fp, "\t%s\n", c->hostname);
293 md5_hash(ipbuf, strlen(ipbuf), &md5);
294 md5_hash(c->hostname, strlen(c->hostname), &md5);
295 }
296
297 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
298 (c->managed_size) ? addrs[i].prefix : c->length);
299 }
300 leasebuf[l - 1] = '\n';
301 fwrite(leasebuf, 1, l, fp);
302 }
303 }
304
305 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
306 struct dhcpv4_assignment *c;
307 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
308 if (!(c->flags & OAF_BOUND))
309 continue;
310
311 char ipbuf[INET6_ADDRSTRLEN];
312 char leasebuf[512];
313 char duidbuf[16];
314 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
315
316 // iface DUID iaid hostname lifetime assigned length [addrs...]
317 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
318 iface->ifname, duidbuf,
319 (c->hostname ? c->hostname : "-"),
320 (c->valid_until > now ?
321 (c->valid_until - now + wall_time) :
322 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
323 c->addr);
324
325 struct in_addr addr = {htonl(c->addr)};
326 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
327
328 if (c->hostname) {
329 fputs(ipbuf, fp);
330
331 char b[256];
332 if (dn_expand(iface->search, iface->search + iface->search_len,
333 iface->search, b, sizeof(b)) > 0)
334 fprintf(fp, "\t%s.%s", c->hostname, b);
335
336 fprintf(fp, "\t%s\n", c->hostname);
337 md5_hash(ipbuf, strlen(ipbuf), &md5);
338 md5_hash(c->hostname, strlen(c->hostname), &md5);
339 }
340
341 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
342 leasebuf[l - 1] = '\n';
343 fwrite(leasebuf, 1, l, fp);
344 }
345 }
346 }
347
348 fclose(fp);
349 }
350
351 uint8_t newmd5[16];
352 md5_end(newmd5, &md5);
353
354 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
355 memcpy(statemd5, newmd5, sizeof(statemd5));
356 char *argv[2] = {config.dhcp_cb, NULL};
357 if (!vfork()) {
358 execv(argv[0], argv);
359 _exit(128);
360 }
361 }
362 }
363
364
365 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
366 {
367 if (a->length > 64 || a->managed_size < 0)
368 return;
369
370 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
371 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
372
373 for (size_t i = 0; i < addrlen; ++i) {
374 struct in6_addr prefix = addrs[i].addr;
375 prefix.s6_addr32[1] |= htonl(a->assigned);
376 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
377 iface, &a->peer.sin6_addr, 1024, add);
378 }
379 }
380
381
382 // More data was received from TCP connection
383 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
384 {
385 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
386 time_t now = odhcpd_time();
387 bool first = c->managed_size < 0;
388
389 for (;;) {
390 int pending;
391 char *data = ustream_get_read_buf(s, &pending);
392 char *end = memmem(data, pending, "\n\n", 2);
393
394 if (!end)
395 break;
396
397 end += 2;
398 end[-1] = 0;
399
400 c->managed_size = 0;
401 if (c->accept_reconf)
402 c->reconf_cnt = 1;
403
404 char *saveptr;
405 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
406 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
407 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
408
409 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
410 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
411 continue;
412
413 x = strtok_r(NULL, ",", &saveptr2);
414 if (sscanf(x, "%hhu", &n->prefix) < 1)
415 continue;
416
417 x = strtok_r(NULL, ",", &saveptr2);
418 if (sscanf(x, "%u", &n->preferred) < 1)
419 continue;
420
421 x = strtok_r(NULL, ",", &saveptr2);
422 if (sscanf(x, "%u", &n->valid) < 1)
423 continue;
424
425 if (n->preferred > n->valid)
426 continue;
427
428 if (UINT32_MAX - now < n->preferred)
429 n->preferred = UINT32_MAX;
430 else
431 n->preferred += now;
432
433 if (UINT32_MAX - now < n->valid)
434 n->valid = UINT32_MAX;
435 else
436 n->valid += now;
437
438 n->dprefix = 0;
439
440 ++c->managed_size;
441 }
442
443 ustream_consume(s, end - data);
444 }
445
446 if (first && c->managed_size == 0)
447 free_dhcpv6_assignment(c);
448 else if (first)
449 c->valid_until = now + 150;
450 }
451
452
453 // TCP transmission has ended, either because of success or timeout or other error
454 static void managed_handle_pd_done(struct ustream *s)
455 {
456 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
457 c->valid_until = odhcpd_time() + 15;
458 c->managed_size = 0;
459 if (c->accept_reconf)
460 c->reconf_cnt = 1;
461 }
462
463
464
465 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
466 {
467 struct dhcpv6_assignment *c;
468
469 if (iface->dhcpv6_pd_manager[0]) {
470 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
471 if (fd >= 0) {
472 char iaidbuf[298];
473 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
474
475 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
476 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
477 ustream_fd_init(&assign->managed_sock, fd);
478 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
479 iaidbuf, assign->iaid, assign->length);
480 ustream_write_pending(&assign->managed_sock.stream);
481 assign->managed_size = -1;
482 assign->valid_until = odhcpd_time() + 15;
483 list_add(&assign->head, &iface->ia_assignments);
484
485 // Wait initial period of up to 250ms for immediate assignment
486 struct pollfd pfd = { .fd = fd, .events = POLLIN };
487 poll(&pfd, 1, 250);
488 managed_handle_pd_data(&assign->managed_sock.stream, 0);
489
490 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
491 return true;
492 }
493
494 return false;
495 } else if (iface->ia_addr_len < 1) {
496 return false;
497 }
498
499 // Try honoring the hint first
500 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
501 if (assign->assigned) {
502 list_for_each_entry(c, &iface->ia_assignments, head) {
503 if (c->length == 128 || c->length == 0)
504 continue;
505
506 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
507 list_add_tail(&assign->head, &c->head);
508 apply_lease(iface, assign, true);
509 return true;
510 }
511
512 if (c->assigned != 0)
513 current = (c->assigned + (1 << (64 - c->length)));
514 }
515 }
516
517 // Fallback to a variable assignment
518 current = 1;
519 list_for_each_entry(c, &iface->ia_assignments, head) {
520 if (c->length == 128 || c->length == 0)
521 continue;
522
523 current = (current + asize) & (~asize);
524 if (current + asize < c->assigned) {
525 assign->assigned = current;
526 list_add_tail(&assign->head, &c->head);
527 apply_lease(iface, assign, true);
528 return true;
529 }
530
531 if (c->assigned != 0)
532 current = (c->assigned + (1 << (64 - c->length)));
533 }
534
535 return false;
536 }
537
538
539 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
540 {
541 // Seed RNG with checksum of DUID
542 uint32_t seed = 0;
543 for (size_t i = 0; i < assign->clid_len; ++i)
544 seed += assign->clid_data[i];
545 srand(seed);
546
547 // Try to assign up to 100x
548 for (size_t i = 0; i < 100; ++i) {
549 uint32_t try;
550 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
551
552 struct dhcpv6_assignment *c;
553 list_for_each_entry(c, &iface->ia_assignments, head) {
554 if (c->length == 0)
555 continue;
556
557 if (c->assigned > try || c->length != 128) {
558 assign->assigned = try;
559 list_add_tail(&assign->head, &c->head);
560 return true;
561 } else if (c->assigned == try) {
562 break;
563 }
564 }
565 }
566
567 return false;
568 }
569
570 void dhcpv6_ia_preupdate(struct interface *iface)
571 {
572 if (iface->dhcpv6 != RELAYD_SERVER)
573 return;
574
575 struct dhcpv6_assignment *c, *border = list_last_entry(
576 &iface->ia_assignments, struct dhcpv6_assignment, head);
577 list_for_each_entry(c, &iface->ia_assignments, head)
578 if (c != border && !iface->managed)
579 apply_lease(iface, c, false);
580 }
581
582 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
583 {
584 if (iface->dhcpv6 != RELAYD_SERVER)
585 return;
586
587 int minprefix = -1;
588 for (size_t i = 0; i < iface->ia_addr_len; ++i) {
589 if (iface->ia_addr[i].preferred > (uint32_t)now &&
590 iface->ia_addr[i].prefix < 64 &&
591 iface->ia_addr[i].prefix > minprefix)
592 minprefix = iface->ia_addr[i].prefix;
593 }
594
595 struct dhcpv6_assignment *border = list_last_entry(
596 &iface->ia_assignments, struct dhcpv6_assignment, head);
597 if (minprefix > 32 && minprefix <= 64)
598 border->assigned = 1U << (64 - minprefix);
599 else
600 border->assigned = 0;
601
602 struct list_head reassign = LIST_HEAD_INIT(reassign);
603 struct dhcpv6_assignment *c, *d;
604 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
605 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
606 c->managed_size)
607 continue;
608
609 if (c->length < 128 && c->assigned >= border->assigned && c != border)
610 list_move(&c->head, &reassign);
611 else if (c != border)
612 apply_lease(iface, c, true);
613
614 if (c->accept_reconf && c->reconf_cnt == 0) {
615 c->reconf_cnt = 1;
616 c->reconf_sent = now;
617 send_reconf(iface, c);
618
619 // Leave all other assignments of that client alone
620 struct dhcpv6_assignment *a;
621 list_for_each_entry(a, &iface->ia_assignments, head)
622 if (a != c && a->clid_len == c->clid_len &&
623 !memcmp(a->clid_data, c->clid_data, a->clid_len))
624 c->reconf_cnt = INT_MAX;
625 }
626 }
627
628 while (!list_empty(&reassign)) {
629 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
630 list_del(&c->head);
631 if (!assign_pd(iface, c)) {
632 c->assigned = 0;
633 list_add(&c->head, &iface->ia_assignments);
634 }
635 }
636
637 dhcpv6_write_statefile();
638 }
639
640
641 static void reconf_timer(struct uloop_timeout *event)
642 {
643 time_t now = odhcpd_time();
644 struct interface *iface;
645 list_for_each_entry(iface, &interfaces, head) {
646 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
647 continue;
648
649 struct dhcpv6_assignment *a, *n;
650 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
651 if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
652 if ((a->length < 128 && a->clid_len > 0) ||
653 (a->length == 128 && a->clid_len == 0)) {
654 list_del(&a->head);
655 free_dhcpv6_assignment(a);
656 }
657 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
658 now > a->reconf_sent + (1 << a->reconf_cnt)) {
659 ++a->reconf_cnt;
660 a->reconf_sent = now;
661 send_reconf(iface, a);
662 }
663 }
664 }
665 uloop_timeout_set(event, 2000);
666 }
667
668
669 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
670 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
671 struct interface *iface, bool request)
672 {
673 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
674 return 0;
675
676 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
677 size_t datalen = sizeof(out);
678 time_t now = odhcpd_time();
679
680 if (status) {
681 struct __attribute__((packed)) {
682 uint16_t type;
683 uint16_t len;
684 uint16_t value;
685 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
686 htons(status)};
687
688 memcpy(buf + datalen, &stat, sizeof(stat));
689 datalen += sizeof(stat);
690 } else {
691 if (a) {
692 uint32_t leasetime;
693 if (a->leasetime > 0) {
694 leasetime = a->leasetime;
695 } else {
696 leasetime = iface->dhcpv4_leasetime;
697 }
698 if (leasetime == 0)
699 leasetime = 3600;
700 else if (leasetime < 60)
701 leasetime = 60;
702
703 uint32_t pref = leasetime;
704 uint32_t valid = leasetime;
705
706 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
707 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
708 size_t m = 0;
709
710 for (size_t i = 0; i < addrlen; ++i)
711 if (addrs[i].preferred > addrs[m].preferred ||
712 (addrs[i].preferred == addrs[m].preferred &&
713 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
714 m = i;
715
716 for (size_t i = 0; i < addrlen; ++i) {
717 uint32_t prefix_pref = addrs[i].preferred;
718 uint32_t prefix_valid = addrs[i].valid;
719
720 if (addrs[i].prefix > 96 ||
721 addrs[i].preferred <= (uint32_t)now)
722 continue;
723
724 if (prefix_pref != UINT32_MAX)
725 prefix_pref -= now;
726
727 if (prefix_valid != UINT32_MAX)
728 prefix_valid -= now;
729
730 if (a->length < 128) {
731 struct dhcpv6_ia_prefix p = {
732 .type = htons(DHCPV6_OPT_IA_PREFIX),
733 .len = htons(sizeof(p) - 4),
734 .preferred = htonl(prefix_pref),
735 .valid = htonl(prefix_valid),
736 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
737 .addr = addrs[i].addr
738 };
739 p.addr.s6_addr32[1] |= htonl(a->assigned);
740
741 size_t entrlen = sizeof(p) - 4;
742
743 if (datalen + entrlen + 4 > buflen ||
744 (a->assigned == 0 && a->managed_size == 0) ||
745 (!a->managed_size && a->length <= addrs[i].prefix))
746 continue;
747
748 memcpy(buf + datalen, &p, sizeof(p));
749 datalen += entrlen + 4;
750 } else {
751 struct dhcpv6_ia_addr n = {
752 .type = htons(DHCPV6_OPT_IA_ADDR),
753 .len = htons(sizeof(n) - 4),
754 .addr = addrs[i].addr,
755 .preferred = htonl(prefix_pref),
756 .valid = htonl(prefix_valid)
757 };
758 n.addr.s6_addr32[3] = htonl(a->assigned);
759 size_t entrlen = sizeof(n) - 4;
760
761 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
762 addrs[i].prefix <= 64)
763 continue;
764
765 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
766 continue;
767
768 memcpy(buf + datalen, &n, sizeof(n));
769 datalen += entrlen + 4;
770 }
771
772 // Calculate T1 / T2 based on non-deprecated addresses
773 if (prefix_pref > 0) {
774 if (prefix_pref < pref)
775 pref = prefix_pref;
776
777 if (prefix_valid < valid)
778 valid = prefix_valid;
779 }
780 }
781
782 if (!INFINITE_VALID(a->valid_until))
783 /* UINT32_MAX is considered as infinite leasetime */
784 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
785
786 out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
787 out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
788
789 if (!out.t1)
790 out.t1 = htonl(1);
791
792 if (!out.t2)
793 out.t2 = htonl(1);
794 }
795
796 if (!request) {
797 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
798 uint16_t otype, olen;
799 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
800 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
801 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
802 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
803 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
804 continue;
805
806 bool found = false;
807 if (a) {
808 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
809 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
810
811 for (size_t i = 0; i < addrlen; ++i) {
812 if (addrs[i].prefix > 96 ||
813 addrs[i].preferred <= (uint32_t)now)
814 continue;
815
816 struct in6_addr addr = addrs[i].addr;
817 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
818 addr.s6_addr32[1] |= htonl(a->assigned);
819
820 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
821 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
822 found = true;
823 } else {
824 addr.s6_addr32[3] = htonl(a->assigned);
825
826 if (!memcmp(&n->addr, &addr, sizeof(addr)))
827 found = true;
828 }
829 }
830 }
831
832 if (!found) {
833 if (otype == DHCPV6_OPT_IA_PREFIX) {
834 struct dhcpv6_ia_prefix inv = {
835 .type = htons(DHCPV6_OPT_IA_PREFIX),
836 .len = htons(sizeof(inv) - 4),
837 .preferred = 0,
838 .valid = 0,
839 .prefix = p->prefix,
840 .addr = p->addr
841 };
842
843 if (datalen + sizeof(inv) > buflen)
844 continue;
845
846 memcpy(buf + datalen, &inv, sizeof(inv));
847 datalen += sizeof(inv);
848 } else {
849 struct dhcpv6_ia_addr inv = {
850 .type = htons(DHCPV6_OPT_IA_ADDR),
851 .len = htons(sizeof(inv) - 4),
852 .addr = n->addr,
853 .preferred = 0,
854 .valid = 0
855 };
856
857 if (datalen + sizeof(inv) > buflen)
858 continue;
859
860 memcpy(buf + datalen, &inv, sizeof(inv));
861 datalen += sizeof(inv);
862 }
863 }
864 }
865 }
866 }
867
868 out.len = htons(datalen - 4);
869 memcpy(buf, &out, sizeof(out));
870 return datalen;
871 }
872
873
874 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
875 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
876 {
877 const char *type = "UNKNOWN";
878 const char *status = "UNKNOWN";
879
880 if (msgtype == DHCPV6_MSG_RENEW)
881 return;
882
883 switch (msgtype) {
884 case DHCPV6_MSG_SOLICIT:
885 type = "SOLICIT";
886 break;
887 case DHCPV6_MSG_REQUEST:
888 type = "REQUEST";
889 break;
890 case DHCPV6_MSG_CONFIRM:
891 type = "CONFIRM";
892 break;
893 case DHCPV6_MSG_RENEW:
894 type = "RENEW";
895 break;
896 case DHCPV6_MSG_REBIND:
897 type = "REBIND";
898 break;
899 case DHCPV6_MSG_RELEASE:
900 type = "RELEASE";
901 break;
902 case DHCPV6_MSG_DECLINE:
903 type = "DECLINE";
904 break;
905 }
906
907 switch (code) {
908 case DHCPV6_STATUS_OK:
909 status = "ok";
910 break;
911 case DHCPV6_STATUS_NOADDRSAVAIL:
912 status = "no addresses available";
913 break;
914 case DHCPV6_STATUS_NOBINDING:
915 status = "no binding";
916 break;
917 case DHCPV6_STATUS_NOTONLINK:
918 status = "not on-link";
919 break;
920 case DHCPV6_STATUS_NOPREFIXAVAIL:
921 status = "no prefix available";
922 break;
923 }
924
925 char leasebuf[256] = "";
926
927 if (a) {
928 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
929 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
930 size_t lbsize = 0;
931 char addrbuf[INET6_ADDRSTRLEN];
932
933 for (size_t i = 0; i < addrlen; ++i) {
934 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
935 continue;
936
937 struct in6_addr addr = addrs[i].addr;
938 int prefix = a->managed ? addrs[i].prefix : a->length;
939 if (prefix == 128)
940 addr.s6_addr32[3] = htonl(a->assigned);
941 else
942 addr.s6_addr32[1] |= htonl(a->assigned);
943
944 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
945 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
946 }
947 }
948
949 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
950 duidbuf, iface->ifname, status, leasebuf);
951 }
952
953
954
955 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
956 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
957 {
958 time_t now = odhcpd_time();
959 size_t response_len = 0;
960 const struct dhcpv6_client_header *hdr = data;
961 uint8_t *start = (uint8_t*)&hdr[1], *odata;
962 uint16_t otype, olen;
963
964 // Find and parse client-id and hostname
965 bool accept_reconf = false;
966 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
967 char hostname[256];
968 size_t hostname_len = 0;
969 bool notonlink = false;
970 char duidbuf[261];
971
972 dhcpv6_for_each_option(start, end, otype, olen, odata) {
973 if (otype == DHCPV6_OPT_CLIENTID) {
974 clid_data = odata;
975 clid_len = olen;
976
977 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
978 memcpy(mac, &odata[8], sizeof(mac));
979 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
980 memcpy(mac, &odata[4], sizeof(mac));
981
982 if (olen <= 130)
983 odhcpd_hexlify(duidbuf, odata, olen);
984 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
985 uint8_t fqdn_buf[256];
986 memcpy(fqdn_buf, odata, olen);
987 fqdn_buf[olen++] = 0;
988
989 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
990 hostname_len = strcspn(hostname, ".");
991 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
992 accept_reconf = true;
993 }
994 }
995
996 if (!clid_data || !clid_len || clid_len > 130)
997 goto out;
998
999 struct dhcpv6_assignment *first = NULL;
1000 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1001 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1002 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1003 bool ia_addr_present = false;
1004 if (!is_pd && !is_na)
1005 continue;
1006
1007 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1008 size_t ia_response_len = 0;
1009 uint8_t reqlen = (is_pd) ? 62 : 128;
1010 uint32_t reqhint = 0;
1011
1012 // Parse request hint for IA-PD
1013 if (is_pd) {
1014 uint8_t *sdata;
1015 uint16_t stype, slen;
1016 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1017 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1018 continue;
1019
1020 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1021 if (p->prefix) {
1022 reqlen = p->prefix;
1023 reqhint = ntohl(p->addr.s6_addr32[1]);
1024 if (reqlen > 32 && reqlen <= 64)
1025 reqhint &= (1U << (64 - reqlen)) - 1;
1026 }
1027 }
1028
1029 if (reqlen > 64)
1030 reqlen = 64;
1031 } else if (is_na) {
1032 uint8_t *sdata;
1033 uint16_t stype, slen;
1034 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1035 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1036 continue;
1037
1038 ia_addr_present = true;
1039 }
1040 }
1041
1042 // Find assignment
1043 struct dhcpv6_assignment *c, *a = NULL;
1044 list_for_each_entry(c, &iface->ia_assignments, head) {
1045 if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1046 (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1047 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1048 (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1049 ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1050 a = c;
1051
1052 // Reset state
1053 apply_lease(iface, a, false);
1054 memcpy(a->clid_data, clid_data, clid_len);
1055 a->clid_len = clid_len;
1056 a->iaid = ia->iaid;
1057 a->peer = *addr;
1058 a->reconf_cnt = 0;
1059 a->reconf_sent = 0;
1060 break;
1061 }
1062 }
1063
1064 // Generic message handling
1065 uint16_t status = DHCPV6_STATUS_OK;
1066 if (a && a->managed_size < 0) {
1067 return -1;
1068 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1069 bool assigned = !!a;
1070
1071 if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1072 a = calloc(1, sizeof(*a) + clid_len);
1073 if (a) {
1074 a->clid_len = clid_len;
1075 a->iaid = ia->iaid;
1076 a->length = reqlen;
1077 a->peer = *addr;
1078 a->assigned = reqhint;
1079 // Set valid time to current time indicating
1080 // assignment is not having infinite lifetime
1081 a->valid_until = now;
1082
1083 if (first)
1084 memcpy(a->key, first->key, sizeof(a->key));
1085 else
1086 odhcpd_urandom(a->key, sizeof(a->key));
1087 memcpy(a->clid_data, clid_data, clid_len);
1088
1089 if (is_pd)
1090 while (!(assigned = assign_pd(iface, a)) &&
1091 !a->managed_size && ++a->length <= 64);
1092 else
1093 assigned = assign_na(iface, a);
1094
1095 if (a->managed_size && !assigned)
1096 return -1;
1097 }
1098 }
1099
1100 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1101 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1102 } else if (assigned && !first) { //
1103 size_t handshake_len = 4;
1104 buf[0] = 0;
1105 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1106 buf[2] = 0;
1107 buf[3] = 0;
1108
1109 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1110 struct dhcpv6_auth_reconfigure auth = {
1111 htons(DHCPV6_OPT_AUTH),
1112 htons(sizeof(auth) - 4),
1113 3, 1, 0,
1114 {htonl(time(NULL)), htonl(++serial)},
1115 1,
1116 {0}
1117 };
1118 memcpy(auth.key, a->key, sizeof(a->key));
1119 memcpy(buf + handshake_len, &auth, sizeof(auth));
1120 handshake_len += sizeof(auth);
1121 }
1122
1123 buf += handshake_len;
1124 buflen -= handshake_len;
1125 response_len += handshake_len;
1126
1127 first = a;
1128 }
1129
1130 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1131
1132 // Was only a solicitation: mark binding for removal
1133 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1134 a->flags &= ~OAF_BOUND;
1135
1136 if (!(a->flags & OAF_STATIC))
1137 a->valid_until = now;
1138 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1139 if (hostname_len > 0) {
1140 a->hostname = realloc(a->hostname, hostname_len + 1);
1141 if (a->hostname) {
1142 memcpy(a->hostname, hostname, hostname_len);
1143 a->hostname[hostname_len] = 0;
1144 }
1145 }
1146 a->accept_reconf = accept_reconf;
1147 a->flags |= OAF_BOUND;
1148 apply_lease(iface, a, true);
1149 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1150 free_dhcpv6_assignment(a);
1151 }
1152 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1153 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1154 hdr->msg_type == DHCPV6_MSG_REBIND ||
1155 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1156 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1157 status = DHCPV6_STATUS_NOBINDING;
1158 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1159 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1160 hdr->msg_type == DHCPV6_MSG_REBIND) {
1161 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1162 if (a) {
1163 a->flags |= OAF_BOUND;
1164 apply_lease(iface, a, true);
1165 }
1166 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1167 if (!(a->flags & OAF_STATIC))
1168 a->valid_until = now - 1;
1169
1170 a->flags &= ~OAF_BOUND;
1171 apply_lease(iface, a, false);
1172 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1173 a->flags &= ~OAF_BOUND;
1174
1175 if (!(a->flags & OAF_STATIC)) {
1176 a->clid_len = 0;
1177 a->valid_until = now + 3600; // Block address for 1h
1178 }
1179 }
1180 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1181 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1182 status = DHCPV6_STATUS_NOTONLINK;
1183 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1184 notonlink = true;
1185 }
1186
1187 buf += ia_response_len;
1188 buflen -= ia_response_len;
1189 response_len += ia_response_len;
1190 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1191 }
1192
1193 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1194 response_len + 6 < buflen) {
1195 buf[0] = 0;
1196 buf[1] = DHCPV6_OPT_STATUS;
1197 buf[2] = 0;
1198 buf[3] = 2;
1199 buf[4] = 0;
1200 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1201 response_len += 6;
1202 }
1203
1204 dhcpv6_write_statefile();
1205
1206 out:
1207 return response_len;
1208 }
OpenWrt DHCP Server