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Fix hostname export
[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 update(struct interface *iface);
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->classes);
64 free(c);
65 }
66
67
68 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
69 {
70 if (!enable && iface->ia_assignments.next) {
71 struct dhcpv6_assignment *c;
72 while (!list_empty(&iface->ia_assignments)) {
73 c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
74 free_dhcpv6_assignment(c);
75 }
76 }
77
78 if (iface->dhcpv6 == RELAYD_SERVER) {
79 if (!iface->ia_assignments.next)
80 INIT_LIST_HEAD(&iface->ia_assignments);
81
82 if (list_empty(&iface->ia_assignments)) {
83 struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
84 if (!border) {
85 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
86 return -1;
87 }
88
89 border->length = 64;
90 list_add(&border->head, &iface->ia_assignments);
91 }
92
93 update(iface);
94
95 // Parse static entries
96 struct lease *lease;
97 list_for_each_entry(lease, &leases, head) {
98 // Construct entry
99 struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
100 if (!a) {
101 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
102 iface->ifname);
103 return -1;
104 }
105
106 a->clid_len = lease->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, a->clid_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->classes);
137 free(a->hostname);
138 free(a);
139 }
140 }
141 }
142 return 0;
143 }
144
145
146 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
147 {
148 struct {
149 struct dhcpv6_client_header hdr;
150 uint16_t srvid_type;
151 uint16_t srvid_len;
152 uint16_t duid_type;
153 uint16_t hardware_type;
154 uint8_t mac[6];
155 uint16_t msg_type;
156 uint16_t msg_len;
157 uint8_t msg_id;
158 struct dhcpv6_auth_reconfigure auth;
159 uint16_t clid_type;
160 uint16_t clid_len;
161 uint8_t clid_data[128];
162 } __attribute__((packed)) reconf_msg = {
163 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
164 .srvid_type = htons(DHCPV6_OPT_SERVERID),
165 .srvid_len = htons(10),
166 .duid_type = htons(3),
167 .hardware_type = htons(1),
168 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
169 .msg_len = htons(1),
170 .msg_id = DHCPV6_MSG_RENEW,
171 .auth = {htons(DHCPV6_OPT_AUTH),
172 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
173 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
174 .clid_type = htons(DHCPV6_OPT_CLIENTID),
175 .clid_len = htons(assign->clid_len),
176 .clid_data = {0},
177 };
178
179 odhcpd_get_mac(iface, reconf_msg.mac);
180 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
181 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
182
183 md5_ctx_t md5;
184 uint8_t secretbytes[64];
185 memset(secretbytes, 0, sizeof(secretbytes));
186 memcpy(secretbytes, assign->key, sizeof(assign->key));
187
188 for (size_t i = 0; i < sizeof(secretbytes); ++i)
189 secretbytes[i] ^= 0x36;
190
191 md5_begin(&md5);
192 md5_hash(secretbytes, sizeof(secretbytes), &md5);
193 md5_hash(iov.iov_base, iov.iov_len, &md5);
194 md5_end(reconf_msg.auth.key, &md5);
195
196 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
197 secretbytes[i] ^= 0x36;
198 secretbytes[i] ^= 0x5c;
199 }
200
201 md5_begin(&md5);
202 md5_hash(secretbytes, sizeof(secretbytes), &md5);
203 md5_hash(reconf_msg.auth.key, 16, &md5);
204 md5_end(reconf_msg.auth.key, &md5);
205
206 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
207 }
208
209
210 void dhcpv6_write_statefile(void)
211 {
212 md5_ctx_t md5;
213 md5_begin(&md5);
214
215 if (config.dhcp_statefile) {
216 time_t now = odhcpd_time(), wall_time = time(NULL);
217 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
218 if (fd < 0)
219 return;
220
221 lockf(fd, F_LOCK, 0);
222 ftruncate(fd, 0);
223
224 FILE *fp = fdopen(fd, "w");
225 if (!fp) {
226 close(fd);
227 return;
228 }
229
230 struct interface *iface;
231 list_for_each_entry(iface, &interfaces, head) {
232 if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
233 continue;
234
235 if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
236 struct dhcpv6_assignment *c;
237 list_for_each_entry(c, &iface->ia_assignments, head) {
238 if (c->clid_len == 0 || c->managed_size < 0)
239 continue;
240
241 char ipbuf[INET6_ADDRSTRLEN];
242 char leasebuf[512];
243 char duidbuf[264];
244 odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
245
246 // iface DUID iaid hostname lifetime assigned length [addrs...]
247 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
248 iface->ifname, duidbuf, ntohl(c->iaid),
249 (c->hostname ? c->hostname : "-"),
250 (unsigned)(c->valid_until > now ?
251 (c->valid_until - now + wall_time) : 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 mostpref = 0;
258
259 for (size_t i = 0; i < addrlen; ++i)
260 if (addrs[i].preferred > addrs[mostpref].preferred)
261 mostpref = i;
262
263 for (size_t i = 0; i < addrlen; ++i) {
264 if (addrs[i].prefix > 96 || c->valid_until <= now ||
265 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != mostpref))
266 continue;
267
268 addr = addrs[i].addr;
269 if (c->length == 128)
270 addr.s6_addr32[3] = htonl(c->assigned);
271 else
272 addr.s6_addr32[1] |= htonl(c->assigned);
273
274 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
275
276 if (c->length == 128 && c->hostname) {
277 fputs(ipbuf, fp);
278
279 char b[256];
280 if (dn_expand(iface->search, iface->search + iface->search_len,
281 iface->search, b, sizeof(b)) > 0)
282 fprintf(fp, "\t%s.%s", c->hostname, b);
283
284 fprintf(fp, "\t%s\n", c->hostname);
285 md5_hash(ipbuf, strlen(ipbuf), &md5);
286 md5_hash(c->hostname, strlen(c->hostname), &md5);
287 }
288
289 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
290 (c->managed_size) ? addrs[i].prefix : c->length);
291 }
292 leasebuf[l - 1] = '\n';
293 fwrite(leasebuf, 1, l, fp);
294 }
295 }
296
297 if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
298 struct dhcpv4_assignment *c;
299 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
300 char ipbuf[INET6_ADDRSTRLEN];
301 char leasebuf[512];
302 char duidbuf[16];
303 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
304
305 // iface DUID iaid hostname lifetime assigned length [addrs...]
306 int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
307 iface->ifname, duidbuf,
308 (c->hostname ? c->hostname : "-"),
309 (unsigned)(c->valid_until > now ?
310 (c->valid_until - now + wall_time) : 0),
311 c->addr);
312
313 struct in_addr addr = {htonl(c->addr)};
314 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
315
316 if (c->hostname[0]) {
317 fputs(ipbuf, fp);
318
319 char b[256];
320 if (dn_expand(iface->search, iface->search + iface->search_len,
321 iface->search, b, sizeof(b)) > 0)
322 fprintf(fp, "\t%s.%s", c->hostname, b);
323
324 fprintf(fp, "\t%s\n", c->hostname);
325 md5_hash(ipbuf, strlen(ipbuf), &md5);
326 md5_hash(c->hostname, strlen(c->hostname), &md5);
327 }
328
329 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
330 leasebuf[l - 1] = '\n';
331 fwrite(leasebuf, 1, l, fp);
332 }
333 }
334 }
335
336 fclose(fp);
337 }
338
339 uint8_t newmd5[16];
340 md5_end(newmd5, &md5);
341
342 if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
343 memcpy(statemd5, newmd5, sizeof(statemd5));
344 char *argv[2] = {config.dhcp_cb, NULL};
345 if (!vfork()) {
346 execv(argv[0], argv);
347 _exit(128);
348 }
349 }
350 }
351
352
353 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
354 {
355 if (a->length > 64 || a->managed_size < 0)
356 return;
357
358 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
359 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
360
361 for (size_t i = 0; i < addrlen; ++i) {
362 struct in6_addr prefix = addrs[i].addr;
363 prefix.s6_addr32[1] |= htonl(a->assigned);
364 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
365 iface, &a->peer.sin6_addr, add);
366 }
367 }
368
369
370 // More data was received from TCP connection
371 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
372 {
373 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
374 time_t now = odhcpd_time();
375 bool first = c->managed_size < 0;
376
377 for (;;) {
378 int pending;
379 char *data = ustream_get_read_buf(s, &pending);
380 char *end = memmem(data, pending, "\n\n", 2);
381
382 if (!end)
383 break;
384
385 end += 2;
386 end[-1] = 0;
387
388 c->managed_size = 0;
389 if (c->accept_reconf)
390 c->reconf_cnt = 1;
391
392 char *saveptr;
393 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
394 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
395 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
396
397 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
398 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
399 continue;
400
401 x = strtok_r(NULL, ",", &saveptr2);
402 if (sscanf(x, "%hhu", &n->prefix) < 1)
403 continue;
404
405 x = strtok_r(NULL, ",", &saveptr2);
406 if (sscanf(x, "%u", &n->preferred) < 1)
407 continue;
408
409 x = strtok_r(NULL, ",", &saveptr2);
410 if (sscanf(x, "%u", &n->valid) < 1)
411 continue;
412
413 if (n->preferred > n->valid)
414 continue;
415
416 if (UINT32_MAX - now < n->preferred)
417 n->preferred = UINT32_MAX;
418 else
419 n->preferred += now;
420
421 if (UINT32_MAX - now < n->valid)
422 n->valid = UINT32_MAX;
423 else
424 n->valid += now;
425
426 n->dprefix = 0;
427
428 ++c->managed_size;
429 }
430
431 ustream_consume(s, end - data);
432 }
433
434 if (first && c->managed_size == 0)
435 free_dhcpv6_assignment(c);
436 else if (first)
437 c->valid_until = now + 150;
438 }
439
440
441 // TCP transmission has ended, either because of success or timeout or other error
442 static void managed_handle_pd_done(struct ustream *s)
443 {
444 struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
445 c->valid_until = odhcpd_time() + 15;
446 c->managed_size = 0;
447 if (c->accept_reconf)
448 c->reconf_cnt = 1;
449 }
450
451
452
453 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
454 {
455 struct dhcpv6_assignment *c;
456
457 if (iface->dhcpv6_pd_manager[0]) {
458 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
459 if (fd >= 0) {
460 char iaidbuf[298];
461 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
462
463 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
464 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
465 ustream_fd_init(&assign->managed_sock, fd);
466 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
467 iaidbuf, assign->iaid, assign->length);
468 ustream_write_pending(&assign->managed_sock.stream);
469 assign->managed_size = -1;
470 assign->valid_until = odhcpd_time() + 15;
471 list_add(&assign->head, &iface->ia_assignments);
472
473 // Wait initial period of up to 250ms for immediate assignment
474 struct pollfd pfd = { .fd = fd, .events = POLLIN };
475 poll(&pfd, 1, 250);
476 managed_handle_pd_data(&assign->managed_sock.stream, 0);
477
478 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
479 return true;
480 }
481
482 return false;
483 } else if (iface->ia_addr_len < 1) {
484 return false;
485 }
486
487 // Try honoring the hint first
488 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
489 if (assign->assigned) {
490 list_for_each_entry(c, &iface->ia_assignments, head) {
491 if (c->length == 128 || c->length == 0)
492 continue;
493
494 if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
495 list_add_tail(&assign->head, &c->head);
496 apply_lease(iface, assign, true);
497 return true;
498 }
499
500 if (c->assigned != 0)
501 current = (c->assigned + (1 << (64 - c->length)));
502 }
503 }
504
505 // Fallback to a variable assignment
506 current = 1;
507 list_for_each_entry(c, &iface->ia_assignments, head) {
508 if (c->length == 128 || c->length == 0)
509 continue;
510
511 current = (current + asize) & (~asize);
512 if (current + asize < c->assigned) {
513 assign->assigned = current;
514 list_add_tail(&assign->head, &c->head);
515 apply_lease(iface, assign, true);
516 return true;
517 }
518
519 if (c->assigned != 0)
520 current = (c->assigned + (1 << (64 - c->length)));
521 }
522
523 return false;
524 }
525
526
527 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
528 {
529 // Seed RNG with checksum of DUID
530 uint32_t seed = 0;
531 for (size_t i = 0; i < assign->clid_len; ++i)
532 seed += assign->clid_data[i];
533 srand(seed);
534
535 // Try to assign up to 100x
536 for (size_t i = 0; i < 100; ++i) {
537 uint32_t try;
538 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
539
540 struct dhcpv6_assignment *c;
541 list_for_each_entry(c, &iface->ia_assignments, head) {
542 if (c->length == 0)
543 continue;
544
545 if (c->assigned > try || c->length != 128) {
546 assign->assigned = try;
547 list_add_tail(&assign->head, &c->head);
548 return true;
549 } else if (c->assigned == try) {
550 break;
551 }
552 }
553 }
554
555 return false;
556 }
557
558
559 static int prefixcmp(const void *va, const void *vb)
560 {
561 const struct odhcpd_ipaddr *a = va, *b = vb;
562 uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
563 uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
564 return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
565 }
566
567
568 static void update(struct interface *iface)
569 {
570 struct odhcpd_ipaddr addr[8];
571 memset(addr, 0, sizeof(addr));
572 int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
573
574 if (len < 0)
575 return;
576
577 qsort(addr, len, sizeof(*addr), prefixcmp);
578
579 time_t now = odhcpd_time();
580 int minprefix = -1;
581
582 for (int i = 0; i < len; ++i) {
583 if (addr[i].preferred > 0 && addr[i].prefix > minprefix)
584 minprefix = addr[i].prefix;
585
586 addr[i].addr.s6_addr32[3] = 0;
587
588 if (addr[i].preferred < UINT32_MAX - now)
589 addr[i].preferred += now;
590
591 if (addr[i].valid < UINT32_MAX - now)
592 addr[i].valid += now;
593 }
594
595 struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
596 border->assigned = 1 << (64 - minprefix);
597
598 bool change = len != (int)iface->ia_addr_len;
599 for (int i = 0; !change && i < len; ++i)
600 if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
601 addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
602 (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
603 (addr[i].valid > (uint32_t)now + 7200) !=
604 (iface->ia_addr[i].valid > (uint32_t)now + 7200))
605 change = true;
606
607 if (change) {
608 struct dhcpv6_assignment *c;
609 list_for_each_entry(c, &iface->ia_assignments, head)
610 if (c != border && !iface->managed)
611 apply_lease(iface, c, false);
612 }
613
614 memcpy(iface->ia_addr, addr, len * sizeof(*addr));
615 iface->ia_addr_len = len;
616
617 if (change) { // Addresses / prefixes have changed
618 struct list_head reassign = LIST_HEAD_INIT(reassign);
619 struct dhcpv6_assignment *c, *d;
620 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
621 if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
622 continue;
623
624 if (c->length < 128 && c->assigned >= border->assigned && c != border)
625 list_move(&c->head, &reassign);
626 else if (c != border)
627 apply_lease(iface, c, true);
628
629 if (c->accept_reconf && c->reconf_cnt == 0) {
630 c->reconf_cnt = 1;
631 c->reconf_sent = now;
632 send_reconf(iface, c);
633
634 // Leave all other assignments of that client alone
635 struct dhcpv6_assignment *a;
636 list_for_each_entry(a, &iface->ia_assignments, head)
637 if (a != c && a->clid_len == c->clid_len &&
638 !memcmp(a->clid_data, c->clid_data, a->clid_len))
639 c->reconf_cnt = INT_MAX;
640 }
641 }
642
643 while (!list_empty(&reassign)) {
644 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
645 list_del(&c->head);
646 if (!assign_pd(iface, c)) {
647 c->assigned = 0;
648 list_add(&c->head, &iface->ia_assignments);
649 }
650 }
651
652 dhcpv6_write_statefile();
653 }
654 }
655
656
657 static void reconf_timer(struct uloop_timeout *event)
658 {
659 time_t now = odhcpd_time();
660 struct interface *iface;
661 list_for_each_entry(iface, &interfaces, head) {
662 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
663 continue;
664
665 struct dhcpv6_assignment *a, *n;
666 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
667 if (a->valid_until < now) {
668 if ((a->length < 128 && a->clid_len > 0) ||
669 (a->length == 128 && a->clid_len == 0)) {
670 list_del(&a->head);
671 free_dhcpv6_assignment(a);
672 }
673 } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
674 now > a->reconf_sent + (1 << a->reconf_cnt)) {
675 ++a->reconf_cnt;
676 a->reconf_sent = now;
677 send_reconf(iface, a);
678 }
679 }
680 }
681 uloop_timeout_set(event, 2000);
682 }
683
684
685 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
686 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
687 struct interface *iface, bool request)
688 {
689 if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
690 return 0;
691
692 struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
693 size_t datalen = sizeof(out);
694 time_t now = odhcpd_time();
695
696 if (status) {
697 struct __attribute__((packed)) {
698 uint16_t type;
699 uint16_t len;
700 uint16_t value;
701 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
702 htons(status)};
703
704 memcpy(buf + datalen, &stat, sizeof(stat));
705 datalen += sizeof(stat);
706 } else {
707 if (a) {
708 uint32_t leasetime = iface->dhcpv4_leasetime;
709 if (leasetime == 0)
710 leasetime = 3600;
711 else if (leasetime < 60)
712 leasetime = 60;
713
714 uint32_t pref = leasetime;
715 uint32_t valid = leasetime;
716
717 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
718 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
719 size_t mostpref = 0;
720
721 for (size_t i = 0; i < addrlen; ++i)
722 if (addrs[i].preferred > addrs[mostpref].preferred)
723 mostpref = i;
724
725 for (size_t i = 0; i < addrlen; ++i) {
726 uint32_t prefix_pref = addrs[i].preferred - now;
727 uint32_t prefix_valid = addrs[i].valid - now;
728
729 if (addrs[i].prefix > 96 ||
730 addrs[i].preferred <= (uint32_t)now)
731 continue;
732
733 if (a->length < 128) {
734 struct dhcpv6_ia_prefix p = {
735 .type = htons(DHCPV6_OPT_IA_PREFIX),
736 .len = htons(sizeof(p) - 4),
737 .preferred = htonl(prefix_pref),
738 .valid = htonl(prefix_valid),
739 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
740 .addr = addrs[i].addr
741 };
742 p.addr.s6_addr32[1] |= htonl(a->assigned);
743
744 size_t entrlen = sizeof(p) - 4;
745
746 if (datalen + entrlen + 4 > buflen ||
747 (a->assigned == 0 && a->managed_size == 0))
748 continue;
749
750 memcpy(buf + datalen, &p, sizeof(p));
751 datalen += entrlen + 4;
752 } else {
753 struct dhcpv6_ia_addr n = {
754 .type = htons(DHCPV6_OPT_IA_ADDR),
755 .len = htons(sizeof(n) - 4),
756 .addr = addrs[i].addr,
757 .preferred = htonl(prefix_pref),
758 .valid = htonl(prefix_valid)
759 };
760 n.addr.s6_addr32[3] = htonl(a->assigned);
761 size_t entrlen = sizeof(n) - 4;
762
763 if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != mostpref)
764 continue;
765
766 if (datalen + entrlen + 4 > buflen || a->assigned == 0)
767 continue;
768
769 memcpy(buf + datalen, &n, sizeof(n));
770 datalen += entrlen + 4;
771 }
772
773 // Calculate T1 / T2 based on non-deprecated addresses
774 if (prefix_pref > 0) {
775 if (prefix_pref < pref)
776 pref = prefix_pref;
777
778 if (prefix_valid < valid)
779 valid = prefix_valid;
780 }
781 }
782
783 a->valid_until = valid + now;
784 out.t1 = htonl(pref * 5 / 10);
785 out.t2 = htonl(pref * 8 / 10);
786
787 if (!out.t1)
788 out.t1 = htonl(1);
789
790 if (!out.t2)
791 out.t2 = htonl(1);
792 }
793
794 if (!request) {
795 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
796 uint16_t otype, olen;
797 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
798 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
799 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
800 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
801 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
802 continue;
803
804 bool found = false;
805 if (a) {
806 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
807 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
808
809 for (size_t i = 0; i < addrlen; ++i) {
810 if (addrs[i].prefix > 96 ||
811 addrs[i].preferred <= (uint32_t)now)
812 continue;
813
814 struct in6_addr addr = addrs[i].addr;
815 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
816 addr.s6_addr32[1] |= htonl(a->assigned);
817
818 if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
819 p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
820 found = true;
821 } else {
822 addr.s6_addr32[3] = htonl(a->assigned);
823
824 if (!memcmp(&n->addr, &addr, sizeof(addr)))
825 found = true;
826 }
827 }
828 }
829
830 if (!found) {
831 if (otype == DHCPV6_OPT_IA_PREFIX) {
832 struct dhcpv6_ia_prefix inv = {
833 .type = htons(DHCPV6_OPT_IA_PREFIX),
834 .len = htons(sizeof(inv) - 4),
835 .preferred = 0,
836 .valid = 0,
837 .prefix = p->prefix,
838 .addr = p->addr
839 };
840
841 if (datalen + sizeof(inv) > buflen)
842 continue;
843
844 memcpy(buf + datalen, &inv, sizeof(inv));
845 datalen += sizeof(inv);
846 } else {
847 struct dhcpv6_ia_addr inv = {
848 .type = htons(DHCPV6_OPT_IA_ADDR),
849 .len = htons(sizeof(inv) - 4),
850 .addr = n->addr,
851 .preferred = 0,
852 .valid = 0
853 };
854
855 if (datalen + sizeof(inv) > buflen)
856 continue;
857
858 memcpy(buf + datalen, &inv, sizeof(inv));
859 datalen += sizeof(inv);
860 }
861 }
862 }
863 }
864 }
865
866 out.len = htons(datalen - 4);
867 memcpy(buf, &out, sizeof(out));
868 return datalen;
869 }
870
871
872 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
873 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
874 {
875 const char *type = "UNKNOWN";
876 const char *status = "UNKNOWN";
877
878 if (msgtype == DHCPV6_MSG_RENEW)
879 return;
880
881 switch (msgtype) {
882 case DHCPV6_MSG_SOLICIT:
883 type = "SOLICIT";
884 break;
885 case DHCPV6_MSG_REQUEST:
886 type = "REQUEST";
887 break;
888 case DHCPV6_MSG_CONFIRM:
889 type = "CONFIRM";
890 break;
891 case DHCPV6_MSG_RENEW:
892 type = "RENEW";
893 break;
894 case DHCPV6_MSG_REBIND:
895 type = "REBIND";
896 break;
897 case DHCPV6_MSG_RELEASE:
898 type = "RELEASE";
899 break;
900 case DHCPV6_MSG_DECLINE:
901 type = "DECLINE";
902 break;
903 }
904
905 switch (code) {
906 case DHCPV6_STATUS_OK:
907 status = "ok";
908 break;
909 case DHCPV6_STATUS_NOADDRSAVAIL:
910 status = "no addresses available";
911 break;
912 case DHCPV6_STATUS_NOBINDING:
913 status = "no binding";
914 break;
915 case DHCPV6_STATUS_NOTONLINK:
916 status = "not on-link";
917 break;
918 case DHCPV6_STATUS_NOPREFIXAVAIL:
919 status = "no prefix available";
920 break;
921 }
922
923 char leasebuf[256] = "";
924
925 if (a) {
926 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
927 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
928 size_t lbsize = 0;
929 char addrbuf[INET6_ADDRSTRLEN];
930
931 for (size_t i = 0; i < addrlen; ++i) {
932 if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
933 continue;
934
935 struct in6_addr addr = addrs[i].addr;
936 int prefix = a->managed ? addrs[i].prefix : a->length;
937 if (prefix == 128)
938 addr.s6_addr32[3] = htonl(a->assigned);
939 else
940 addr.s6_addr32[1] |= htonl(a->assigned);
941
942 inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
943 lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
944 }
945 }
946
947 syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
948 duidbuf, iface->ifname, status, leasebuf);
949 }
950
951
952
953 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
954 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
955 {
956 time_t now = odhcpd_time();
957 size_t response_len = 0;
958 const struct dhcpv6_client_header *hdr = data;
959 uint8_t *start = (uint8_t*)&hdr[1], *odata;
960 uint16_t otype, olen;
961
962 // Find and parse client-id and hostname
963 bool accept_reconf = false;
964 uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
965 char hostname[256];
966 size_t hostname_len = 0;
967 bool notonlink = false;
968 char duidbuf[261];
969
970 dhcpv6_for_each_option(start, end, otype, olen, odata) {
971 if (otype == DHCPV6_OPT_CLIENTID) {
972 clid_data = odata;
973 clid_len = olen;
974
975 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
976 memcpy(mac, &odata[8], sizeof(mac));
977 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
978 memcpy(mac, &odata[4], sizeof(mac));
979
980 if (olen <= 130)
981 odhcpd_hexlify(duidbuf, odata, olen);
982 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
983 uint8_t fqdn_buf[256];
984 memcpy(fqdn_buf, odata, olen);
985 fqdn_buf[olen++] = 0;
986
987 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
988 hostname_len = strcspn(hostname, ".");
989 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
990 accept_reconf = true;
991 }
992 }
993
994 if (!clid_data || !clid_len || clid_len > 130)
995 goto out;
996
997 update(iface);
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 || c->valid_until < now) &&
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
1080 if (first)
1081 memcpy(a->key, first->key, sizeof(a->key));
1082 else
1083 odhcpd_urandom(a->key, sizeof(a->key));
1084 memcpy(a->clid_data, clid_data, clid_len);
1085
1086 if (is_pd)
1087 while (!(assigned = assign_pd(iface, a)) &&
1088 !a->managed_size && ++a->length <= 64);
1089 else
1090 assigned = assign_na(iface, a);
1091
1092 if (a->managed_size && !assigned)
1093 return -1;
1094 }
1095 }
1096
1097 if (!assigned || iface->ia_addr_len == 0) { // Set error status
1098 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1099 } else if (assigned && !first) { //
1100 size_t handshake_len = 4;
1101 buf[0] = 0;
1102 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1103 buf[2] = 0;
1104 buf[3] = 0;
1105
1106 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1107 struct dhcpv6_auth_reconfigure auth = {
1108 htons(DHCPV6_OPT_AUTH),
1109 htons(sizeof(auth) - 4),
1110 3, 1, 0,
1111 {htonl(time(NULL)), htonl(++serial)},
1112 1,
1113 {0}
1114 };
1115 memcpy(auth.key, a->key, sizeof(a->key));
1116 memcpy(buf + handshake_len, &auth, sizeof(auth));
1117 handshake_len += sizeof(auth);
1118 }
1119
1120 buf += handshake_len;
1121 buflen -= handshake_len;
1122 response_len += handshake_len;
1123
1124 first = a;
1125 }
1126
1127 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1128
1129 // Was only a solicitation: mark binding for removal
1130 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1131 a->valid_until = 0;
1132 } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1133 if (hostname_len > 0) {
1134 a->hostname = realloc(a->hostname, hostname_len + 1);
1135 if (a->hostname) {
1136 memcpy(a->hostname, hostname, hostname_len);
1137 a->hostname[hostname_len] = 0;
1138 }
1139 }
1140 a->accept_reconf = accept_reconf;
1141 apply_lease(iface, a, true);
1142 } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1143 free_dhcpv6_assignment(a);
1144 }
1145 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1146 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1147 hdr->msg_type == DHCPV6_MSG_REBIND ||
1148 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1149 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1150 status = DHCPV6_STATUS_NOBINDING;
1151 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1152 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1153 hdr->msg_type == DHCPV6_MSG_REBIND) {
1154 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1155 if (a)
1156 apply_lease(iface, a, true);
1157 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1158 a->valid_until = 0;
1159 apply_lease(iface, a, false);
1160 } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1161 a->clid_len = 0;
1162 a->valid_until = now + 3600; // Block address for 1h
1163 }
1164 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1165 // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1166 status = DHCPV6_STATUS_NOTONLINK;
1167 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1168 notonlink = true;
1169 }
1170
1171 buf += ia_response_len;
1172 buflen -= ia_response_len;
1173 response_len += ia_response_len;
1174 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1175 }
1176
1177 if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1178 response_len + 6 < buflen) {
1179 buf[0] = 0;
1180 buf[1] = DHCPV6_OPT_STATUS;
1181 buf[2] = 0;
1182 buf[3] = 2;
1183 buf[4] = 0;
1184 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1185 response_len += 6;
1186 }
1187
1188 dhcpv6_write_statefile();
1189
1190 out:
1191 return response_len;
1192 }
OpenWrt DHCP Server