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[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
20 #include <time.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <stdio.h>
24 #include <poll.h>
25 #include <alloca.h>
26 #include <resolv.h>
27 #include <limits.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31 #include <libgen.h>
32 #include <stdbool.h>
33 #include <arpa/inet.h>
34 #include <sys/timerfd.h>
35
36 #include <libubox/md5.h>
37 #include <libubox/usock.h>
38
39 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
40 ((iface)->dhcpv6_assignall || (i) == (m) || \
41 (addrs)[(i)].prefix > 64)
42
43 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info);
44 static void apply_lease(struct dhcp_assignment *a, bool add);
45 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
46 static void handle_addrlist_change(struct netevent_handler_info *info);
47 static void start_reconf(struct dhcp_assignment *a);
48 static void stop_reconf(struct dhcp_assignment *a);
49 static void valid_until_cb(struct uloop_timeout *event);
50
51 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
52 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
53 static uint32_t serial = 0;
54 static uint8_t statemd5[16];
55
56 int dhcpv6_ia_init(void)
57 {
58 uloop_timeout_set(&valid_until_timeout, 1000);
59
60 netlink_add_netevent_handler(&dhcpv6_netevent_handler);
61
62 return 0;
63 }
64
65 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
66 {
67 enable = enable && (iface->dhcpv6 == MODE_SERVER);
68
69 if (enable) {
70 struct dhcp_assignment *border;
71
72 if (list_empty(&iface->ia_assignments)) {
73 border = alloc_assignment(0);
74
75 if (!border) {
76 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
77 return -1;
78 }
79
80 border->length = 64;
81 list_add(&border->head, &iface->ia_assignments);
82 } else
83 border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
84
85 set_border_assignment_size(iface, border);
86 } else {
87 struct dhcp_assignment *c;
88
89 while (!list_empty(&iface->ia_assignments)) {
90 c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
91 free_assignment(c);
92 }
93 }
94
95 return 0;
96 }
97
98
99 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
100 {
101 struct interface *iface = info->iface;
102
103 if (!iface || iface->dhcpv6 != MODE_SERVER)
104 return;
105
106 switch (event) {
107 case NETEV_ADDR6LIST_CHANGE:
108 handle_addrlist_change(info);
109 break;
110 default:
111 break;
112 }
113 }
114
115
116 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
117 {
118 return (a->managed_size || a->length > prefix_length);
119 }
120
121 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
122 {
123 return (addr->prefix <= 96 && addr->preferred_lt > (uint32_t)now);
124 }
125
126 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
127 {
128 size_t i, m;
129
130 for (i = 0, m = 0; i < addrlen; ++i) {
131 if (addrs[i].preferred_lt > addrs[m].preferred_lt ||
132 (addrs[i].preferred_lt == addrs[m].preferred_lt &&
133 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
134 m = i;
135 }
136
137 return m;
138 }
139
140 static int send_reconf(struct dhcp_assignment *assign)
141 {
142 struct {
143 struct dhcpv6_client_header hdr;
144 uint16_t srvid_type;
145 uint16_t srvid_len;
146 uint16_t duid_type;
147 uint16_t hardware_type;
148 uint8_t mac[6];
149 uint16_t msg_type;
150 uint16_t msg_len;
151 uint8_t msg_id;
152 struct dhcpv6_auth_reconfigure auth;
153 uint16_t clid_type;
154 uint16_t clid_len;
155 uint8_t clid_data[128];
156 } __attribute__((packed)) reconf_msg = {
157 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
158 .srvid_type = htons(DHCPV6_OPT_SERVERID),
159 .srvid_len = htons(10),
160 .duid_type = htons(3),
161 .hardware_type = htons(1),
162 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
163 .msg_len = htons(1),
164 .msg_id = DHCPV6_MSG_RENEW,
165 .auth = {htons(DHCPV6_OPT_AUTH),
166 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
167 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
168 .clid_type = htons(DHCPV6_OPT_CLIENTID),
169 .clid_len = htons(assign->clid_len),
170 .clid_data = {0},
171 };
172 struct interface *iface = assign->iface;
173
174 odhcpd_get_mac(iface, reconf_msg.mac);
175 memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
176 struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
177
178 md5_ctx_t md5;
179 uint8_t secretbytes[64];
180 memset(secretbytes, 0, sizeof(secretbytes));
181 memcpy(secretbytes, assign->key, sizeof(assign->key));
182
183 for (size_t i = 0; i < sizeof(secretbytes); ++i)
184 secretbytes[i] ^= 0x36;
185
186 md5_begin(&md5);
187 md5_hash(secretbytes, sizeof(secretbytes), &md5);
188 md5_hash(iov.iov_base, iov.iov_len, &md5);
189 md5_end(reconf_msg.auth.key, &md5);
190
191 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
192 secretbytes[i] ^= 0x36;
193 secretbytes[i] ^= 0x5c;
194 }
195
196 md5_begin(&md5);
197 md5_hash(secretbytes, sizeof(secretbytes), &md5);
198 md5_hash(reconf_msg.auth.key, 16, &md5);
199 md5_end(reconf_msg.auth.key, &md5);
200
201 return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
202 }
203
204 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
205 {
206 if (a->managed_sock.fd.registered) {
207 ustream_free(&a->managed_sock.stream);
208 close(a->managed_sock.fd.fd);
209 }
210
211 if ((a->flags & OAF_BOUND) && (a->flags & OAF_DHCPV6_PD))
212 apply_lease(a, false);
213
214 if (a->reconf_cnt)
215 stop_reconf(a);
216
217 free(a->managed);
218 }
219
220 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
221 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
222 {
223 struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
224 size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
225 size_t m = get_preferred_addr(addrs, addrlen);
226
227 for (size_t i = 0; i < addrlen; ++i) {
228 struct in6_addr addr;
229 uint32_t preferred_lt, valid_lt;
230 int prefix = c->managed ? addrs[i].prefix : c->length;
231
232 if (!valid_addr(&addrs[i], now))
233 continue;
234
235 /* Filter Out Prefixes */
236 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
237 char addrbuf[INET6_ADDRSTRLEN];
238 syslog(LOG_INFO, "Address %s filtered out on %s",
239 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
240 iface->name);
241 continue;
242 }
243
244 addr = addrs[i].addr.in6;
245 preferred_lt = addrs[i].preferred_lt;
246 valid_lt = addrs[i].valid_lt;
247
248 if (c->flags & OAF_DHCPV6_NA) {
249 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
250 continue;
251
252 addr.s6_addr32[2] = htonl(c->assigned_host_id >> 32);
253 addr.s6_addr32[3] = htonl(c->assigned_host_id & UINT32_MAX);
254 } else {
255 if (!valid_prefix_length(c, addrs[i].prefix))
256 continue;
257
258 addr.s6_addr32[1] |= htonl(c->assigned_subnet_id);
259 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
260 }
261
262 if (preferred_lt > (uint32_t)c->preferred_until)
263 preferred_lt = c->preferred_until;
264
265 if (preferred_lt > (uint32_t)c->valid_until)
266 preferred_lt = c->valid_until;
267
268 if (preferred_lt != UINT32_MAX)
269 preferred_lt -= now;
270
271 if (valid_lt > (uint32_t)c->valid_until)
272 valid_lt = c->valid_until;
273
274 if (valid_lt != UINT32_MAX)
275 valid_lt -= now;
276
277 func(&addr, prefix, preferred_lt, valid_lt, arg);
278 }
279 }
280
281 struct write_ctxt {
282 FILE *fp;
283 md5_ctx_t md5;
284 struct dhcp_assignment *c;
285 struct interface *iface;
286 char *buf;
287 int buf_len;
288 int buf_idx;
289 };
290
291 static void dhcpv6_write_ia_addrhosts(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
292 _unused uint32_t valid_lt, void *arg)
293 {
294 struct write_ctxt *ctxt = (struct write_ctxt *)arg;
295 char ipbuf[INET6_ADDRSTRLEN];
296
297 if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
298 !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
299 inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
300 fputs(ipbuf, ctxt->fp);
301
302 char b[256];
303 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
304 ctxt->iface->search, b, sizeof(b)) > 0)
305 fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
306
307 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
308 }
309 }
310
311 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
312 _unused uint32_t valid_lt, void *arg)
313 {
314 struct write_ctxt *ctxt = (struct write_ctxt *)arg;
315 char ipbuf[INET6_ADDRSTRLEN];
316
317 inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
318
319 if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
320 !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
321 fputs(ipbuf, ctxt->fp);
322
323 char b[256];
324 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
325 ctxt->iface->search, b, sizeof(b)) > 0)
326 fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
327
328 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
329 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
330 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
331 }
332
333 ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
334 "%s/%d ", ipbuf, prefix);
335 }
336
337 static void dhcpv6_ia_write_hostsfile(time_t now)
338 {
339 struct write_ctxt ctxt;
340
341 unsigned hostsfile_strlen = strlen(config.dhcp_hostsfile) + 1;
342 unsigned tmp_hostsfile_strlen = hostsfile_strlen + 1; /* space for . */
343 char *tmp_hostsfile = alloca(tmp_hostsfile_strlen);
344
345 char *dir_hostsfile;
346 char *base_hostsfile;
347 char *pdir_hostsfile;
348 char *pbase_hostsfile;
349
350 int fd, ret;
351
352 dir_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
353 base_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
354
355 pdir_hostsfile = dirname(dir_hostsfile);
356 pbase_hostsfile = basename(base_hostsfile);
357
358 snprintf(tmp_hostsfile, tmp_hostsfile_strlen, "%s/.%s", pdir_hostsfile, pbase_hostsfile);
359
360 free(dir_hostsfile);
361 free(base_hostsfile);
362
363 fd = open(tmp_hostsfile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
364 if (fd < 0)
365 return;
366
367 ret = lockf(fd, F_LOCK, 0);
368 if (ret < 0) {
369 close(fd);
370 return;
371 }
372
373 if (ftruncate(fd, 0) < 0) {}
374
375 ctxt.fp = fdopen(fd, "w");
376 if (!ctxt.fp) {
377 close(fd);
378 return;
379 }
380
381 avl_for_each_element(&interfaces, ctxt.iface, avl) {
382 if (ctxt.iface->dhcpv6 != MODE_SERVER &&
383 ctxt.iface->dhcpv4 != MODE_SERVER)
384 continue;
385
386 if (ctxt.iface->dhcpv6 == MODE_SERVER) {
387 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
388 if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
389 continue;
390
391 if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
392 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
393 dhcpv6_write_ia_addrhosts, &ctxt);
394 }
395 }
396
397 if (ctxt.iface->dhcpv4 == MODE_SERVER) {
398 struct dhcp_assignment *c;
399
400 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
401 if (!(c->flags & OAF_BOUND))
402 continue;
403
404 char ipbuf[INET6_ADDRSTRLEN];
405 struct in_addr addr = {.s_addr = c->addr};
406 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
407
408 if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
409 fputs(ipbuf, ctxt.fp);
410
411 char b[256];
412
413 if (dn_expand(ctxt.iface->search,
414 ctxt.iface->search + ctxt.iface->search_len,
415 ctxt.iface->search, b, sizeof(b)) > 0)
416 fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
417
418 fprintf(ctxt.fp, "\t%s\n", c->hostname);
419 }
420 }
421 }
422 }
423
424 fclose(ctxt.fp);
425
426 rename(tmp_hostsfile, config.dhcp_hostsfile);
427 }
428
429 void dhcpv6_ia_write_statefile(void)
430 {
431 struct write_ctxt ctxt;
432
433 md5_begin(&ctxt.md5);
434
435 if (config.dhcp_statefile) {
436 unsigned statefile_strlen = strlen(config.dhcp_statefile) + 1;
437 unsigned tmp_statefile_strlen = statefile_strlen + 1; /* space for . */
438 char *tmp_statefile = alloca(tmp_statefile_strlen);
439
440 char *dir_statefile;
441 char *base_statefile;
442 char *pdir_statefile;
443 char *pbase_statefile;
444
445 time_t now = odhcpd_time(), wall_time = time(NULL);
446 int fd, ret;
447 char leasebuf[512];
448
449 dir_statefile = strndup(config.dhcp_statefile, statefile_strlen);
450 base_statefile = strndup(config.dhcp_statefile, statefile_strlen);
451
452 pdir_statefile = dirname(dir_statefile);
453 pbase_statefile = basename(base_statefile);
454
455 snprintf(tmp_statefile, tmp_statefile_strlen, "%s/.%s", pdir_statefile, pbase_statefile);
456
457 free(dir_statefile);
458 free(base_statefile);
459
460 fd = open(tmp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
461 if (fd < 0)
462 return;
463
464 ret = lockf(fd, F_LOCK, 0);
465 if (ret < 0) {
466 close(fd);
467 return;
468 }
469
470 if (ftruncate(fd, 0) < 0) {}
471
472 ctxt.fp = fdopen(fd, "w");
473 if (!ctxt.fp) {
474 close(fd);
475 return;
476 }
477
478 ctxt.buf = leasebuf;
479 ctxt.buf_len = sizeof(leasebuf);
480
481 avl_for_each_element(&interfaces, ctxt.iface, avl) {
482 if (ctxt.iface->dhcpv6 != MODE_SERVER &&
483 ctxt.iface->dhcpv4 != MODE_SERVER)
484 continue;
485
486 if (ctxt.iface->dhcpv6 == MODE_SERVER) {
487 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
488 if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
489 continue;
490
491 char duidbuf[264];
492
493 odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
494
495 /* iface DUID iaid hostname lifetime assigned_host_id length [addrs...] */
496 ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" ",
497 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
498 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
499 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
500 (ctxt.c->valid_until > now ?
501 (int64_t)(ctxt.c->valid_until - now + wall_time) :
502 (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
503
504 if (ctxt.c->flags & OAF_DHCPV6_NA)
505 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
506 "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
507 else
508 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
509 "%" PRIx32" %u ", ctxt.c->assigned_subnet_id, (unsigned)ctxt.c->length);
510
511 if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
512 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
513 dhcpv6_write_ia_addr, &ctxt);
514
515 ctxt.buf[ctxt.buf_idx - 1] = '\n';
516 fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
517 }
518 }
519
520 if (ctxt.iface->dhcpv4 == MODE_SERVER) {
521 struct dhcp_assignment *c;
522
523 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
524 if (!(c->flags & OAF_BOUND))
525 continue;
526
527 char ipbuf[INET6_ADDRSTRLEN];
528 char duidbuf[16];
529 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
530
531 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
532 ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
533 ctxt.iface->ifname, duidbuf,
534 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
535 (c->hostname ? c->hostname : "-"),
536 (c->valid_until > now ?
537 (int64_t)(c->valid_until - now + wall_time) :
538 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
539 ntohl(c->addr));
540
541 struct in_addr addr = {.s_addr = c->addr};
542 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
543
544 if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
545 fputs(ipbuf, ctxt.fp);
546
547 char b[256];
548 if (dn_expand(ctxt.iface->search,
549 ctxt.iface->search + ctxt.iface->search_len,
550 ctxt.iface->search, b, sizeof(b)) > 0)
551 fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
552
553 fprintf(ctxt.fp, "\t%s\n", c->hostname);
554 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
555 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
556 }
557
558 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
559 ctxt.buf_len - ctxt.buf_idx,
560 "%s/32 ", ipbuf);
561 ctxt.buf[ctxt.buf_idx - 1] = '\n';
562 fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
563 }
564 }
565 }
566
567 fclose(ctxt.fp);
568
569 uint8_t newmd5[16];
570 md5_end(newmd5, &ctxt.md5);
571
572 rename(tmp_statefile, config.dhcp_statefile);
573
574 if (memcmp(newmd5, statemd5, sizeof(newmd5))) {
575 memcpy(statemd5, newmd5, sizeof(statemd5));
576
577 if (config.dhcp_hostsfile)
578 dhcpv6_ia_write_hostsfile(now);
579
580 if (config.dhcp_cb) {
581 char *argv[2] = {config.dhcp_cb, NULL};
582 if (!vfork()) {
583 execv(argv[0], argv);
584 _exit(128);
585 }
586 }
587 }
588 }
589 }
590
591 static void __apply_lease(struct dhcp_assignment *a,
592 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
593 {
594 if (a->flags & OAF_DHCPV6_NA)
595 return;
596
597 for (ssize_t i = 0; i < addr_len; ++i) {
598 struct in6_addr prefix;
599
600 if (ADDR_MATCH_PIO_FILTER(&addrs[i], a->iface))
601 continue;
602
603 prefix = addrs[i].addr.in6;
604 prefix.s6_addr32[1] |= htonl(a->assigned_subnet_id);
605 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
606 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
607 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
608 }
609 }
610
611 static void apply_lease(struct dhcp_assignment *a, bool add)
612 {
613 struct interface *iface = a->iface;
614 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
615 ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
616
617 __apply_lease(a, addrs, addrlen, add);
618 }
619
620 /* Set border assignment size based on the IPv6 address prefixes */
621 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
622 {
623 time_t now = odhcpd_time();
624 int minprefix = -1;
625
626 for (size_t i = 0; i < iface->addr6_len; ++i) {
627 struct odhcpd_ipaddr *addr = &iface->addr6[i];
628
629 if (ADDR_MATCH_PIO_FILTER(addr, iface))
630 continue;
631
632 if (addr->preferred_lt > (uint32_t)now &&
633 addr->prefix < 64 &&
634 addr->prefix > minprefix)
635 minprefix = addr->prefix;
636 }
637
638 if (minprefix > 32 && minprefix <= 64)
639 b->assigned_subnet_id = 1U << (64 - minprefix);
640 else
641 b->assigned_subnet_id = 0;
642 }
643
644 /* More data was received from TCP connection */
645 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
646 {
647 struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
648 struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
649 time_t now = odhcpd_time();
650 bool first = c->managed_size < 0;
651
652 for (;;) {
653 int pending;
654 char *data = ustream_get_read_buf(s, &pending);
655 char *end = memmem(data, pending, "\n\n", 2);
656
657 if (!end)
658 break;
659
660 end += 2;
661 end[-1] = 0;
662
663 c->managed_size = 0;
664 if (c->accept_reconf)
665 c->reconf_cnt = 1;
666
667 char *saveptr;
668 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
669 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
670 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
671
672 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
673 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
674 continue;
675
676 x = strtok_r(NULL, ",", &saveptr2);
677 if (sscanf(x, "%hhu", &n->prefix) < 1)
678 continue;
679
680 x = strtok_r(NULL, ",", &saveptr2);
681 if (sscanf(x, "%u", &n->preferred_lt) < 1)
682 continue;
683
684 x = strtok_r(NULL, ",", &saveptr2);
685 if (sscanf(x, "%u", &n->valid_lt) < 1)
686 continue;
687
688 if (n->preferred_lt > n->valid_lt)
689 continue;
690
691 if (UINT32_MAX - now < n->preferred_lt)
692 n->preferred_lt = UINT32_MAX;
693 else
694 n->preferred_lt += now;
695
696 if (UINT32_MAX - now < n->valid_lt)
697 n->valid_lt = UINT32_MAX;
698 else
699 n->valid_lt += now;
700
701 n->dprefix = 0;
702
703 ++c->managed_size;
704 }
705
706 ustream_consume(s, end - data);
707 }
708
709 if (first && c->managed_size == 0)
710 free_assignment(c);
711 else if (first)
712 c->valid_until = now + 150;
713 }
714
715
716 /* TCP transmission has ended, either because of success or timeout or other error */
717 static void managed_handle_pd_done(struct ustream *s)
718 {
719 struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
720 struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
721
722 c->valid_until = odhcpd_time() + 15;
723
724 c->managed_size = 0;
725
726 if (c->accept_reconf)
727 c->reconf_cnt = 1;
728 }
729
730 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
731 {
732 struct dhcp_assignment *c;
733
734 if (iface->dhcpv6_pd_manager[0]) {
735 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
736 if (fd >= 0) {
737 struct pollfd pfd = { .fd = fd, .events = POLLIN };
738 char iaidbuf[298];
739
740 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
741
742 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
743 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
744 ustream_fd_init(&assign->managed_sock, fd);
745 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
746 iaidbuf, assign->iaid, assign->length);
747 ustream_write_pending(&assign->managed_sock.stream);
748 assign->managed_size = -1;
749
750 assign->valid_until = odhcpd_time() + 15;
751
752 list_add(&assign->head, &iface->ia_assignments);
753
754 /* Wait initial period of up to 250ms for immediate assignment */
755 if (poll(&pfd, 1, 250) < 0) {
756 syslog(LOG_ERR, "poll(): %m");
757 return false;
758 }
759
760 managed_handle_pd_data(&assign->managed_sock.stream, 0);
761
762 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
763 return true;
764 }
765
766 return false;
767 } else if (iface->addr6_len < 1)
768 return false;
769
770 /* Try honoring the hint first */
771 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
772 if (assign->assigned_subnet_id) {
773 list_for_each_entry(c, &iface->ia_assignments, head) {
774 if (c->flags & OAF_DHCPV6_NA)
775 continue;
776
777 if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
778 list_add_tail(&assign->head, &c->head);
779
780 if (assign->flags & OAF_BOUND)
781 apply_lease(assign, true);
782
783 return true;
784 }
785
786 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
787 }
788 }
789
790 /* Fallback to a variable assignment */
791 current = 1;
792 list_for_each_entry(c, &iface->ia_assignments, head) {
793 if (c->flags & OAF_DHCPV6_NA)
794 continue;
795
796 current = (current + asize) & (~asize);
797
798 if (current + asize < c->assigned_subnet_id) {
799 assign->assigned_subnet_id = current;
800 list_add_tail(&assign->head, &c->head);
801
802 if (assign->flags & OAF_BOUND)
803 apply_lease(assign, true);
804
805 return true;
806 }
807
808 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
809 }
810
811 return false;
812 }
813
814 /* Check iid against reserved IPv6 interface identifiers.
815 Refer to:
816 http://www.iana.org/assignments/ipv6-interface-ids */
817 static bool is_reserved_ipv6_iid(uint64_t iid)
818 {
819 if (iid == 0x0000000000000000)
820 /* Subnet-Router Anycast [RFC4291] */
821 return true;
822
823 if ((iid & 0xFFFFFFFFFF000000) == 0x02005EFFFE000000)
824 /* Reserved IPv6 Interface Identifiers corresponding
825 to the IANA Ethernet Block [RFC4291] */
826 return true;
827
828 if ((iid & 0xFFFFFFFFFFFFFF80) == 0xFDFFFFFFFFFFFF80)
829 /* Reserved Subnet Anycast Addresses [RFC2526] */
830 return true;
831
832 return false;
833 }
834
835 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
836 {
837 struct dhcp_assignment *c;
838 uint32_t seed = 0;
839
840 /* Preconfigured assignment by static lease */
841 if (a->assigned_host_id) {
842 list_for_each_entry(c, &iface->ia_assignments, head) {
843 if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
844 list_add_tail(&a->head, &c->head);
845 return true;
846 } else if (c->assigned_host_id == a->assigned_host_id)
847 return false;
848 }
849 }
850
851 /* Seed RNG with checksum of DUID */
852 for (size_t i = 0; i < a->clid_len; ++i)
853 seed += a->clid_data[i];
854 srandom(seed);
855
856 /* Try to assign up to 100x */
857 for (size_t i = 0; i < 100; ++i) {
858 uint64_t try;
859
860 if (iface->dhcpv6_hostid_len > 32) {
861 uint32_t mask_high;
862
863 if (iface->dhcpv6_hostid_len >= 64)
864 mask_high = UINT32_MAX;
865 else
866 mask_high = (1 << (iface->dhcpv6_hostid_len - 32)) - 1;
867
868 do {
869 try = (uint32_t)random();
870 try |= (uint64_t)((uint32_t)random() & mask_high) << 32;
871 } while (try < 0x100);
872 } else {
873 uint32_t mask_low;
874
875 if (iface->dhcpv6_hostid_len == 32)
876 mask_low = UINT32_MAX;
877 else
878 mask_low = (1 << iface->dhcpv6_hostid_len) - 1;
879 do try = ((uint32_t)random()) & mask_low; while (try < 0x100);
880 }
881
882 if (is_reserved_ipv6_iid(try))
883 continue;
884
885 if (config_find_lease_by_hostid(try))
886 continue;
887
888 list_for_each_entry(c, &iface->ia_assignments, head) {
889 if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
890 a->assigned_host_id = try;
891 list_add_tail(&a->head, &c->head);
892 return true;
893 } else if (c->assigned_host_id == try)
894 break;
895 }
896 }
897
898 return false;
899 }
900
901 static void handle_addrlist_change(struct netevent_handler_info *info)
902 {
903 struct interface *iface = info->iface;
904 struct dhcp_assignment *c, *d, *border = list_last_entry(
905 &iface->ia_assignments, struct dhcp_assignment, head);
906 struct list_head reassign = LIST_HEAD_INIT(reassign);
907 time_t now = odhcpd_time();
908
909 list_for_each_entry(c, &iface->ia_assignments, head) {
910 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
911 && (c->flags & OAF_BOUND))
912 __apply_lease(c, info->addrs_old.addrs,
913 info->addrs_old.len, false);
914 }
915
916 set_border_assignment_size(iface, border);
917
918 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
919 if (c->clid_len == 0 ||
920 !(c->flags & OAF_DHCPV6_PD) ||
921 (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
922 c->managed_size)
923 continue;
924
925 if (c->assigned_subnet_id >= border->assigned_subnet_id)
926 list_move(&c->head, &reassign);
927 else if (c->flags & OAF_BOUND)
928 apply_lease(c, true);
929
930 if (c->accept_reconf && c->reconf_cnt == 0) {
931 struct dhcp_assignment *a;
932
933 start_reconf(c);
934
935 /* Leave all other assignments of that client alone */
936 list_for_each_entry(a, &iface->ia_assignments, head)
937 if (a != c && a->clid_len == c->clid_len &&
938 !memcmp(a->clid_data, c->clid_data, a->clid_len))
939 a->reconf_cnt = INT_MAX;
940 }
941 }
942
943 while (!list_empty(&reassign)) {
944 c = list_first_entry(&reassign, struct dhcp_assignment, head);
945 list_del_init(&c->head);
946 if (!assign_pd(iface, c))
947 free_assignment(c);
948 }
949
950 dhcpv6_ia_write_statefile();
951 }
952
953 static void reconf_timeout_cb(struct uloop_timeout *event)
954 {
955 struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
956
957 if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
958 send_reconf(a);
959 uloop_timeout_set(&a->reconf_timer,
960 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
961 a->reconf_cnt++;
962 } else
963 stop_reconf(a);
964 }
965
966 static void start_reconf(struct dhcp_assignment *a)
967 {
968 uloop_timeout_set(&a->reconf_timer,
969 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
970 a->reconf_timer.cb = reconf_timeout_cb;
971 a->reconf_cnt++;
972
973 send_reconf(a);
974 }
975
976 static void stop_reconf(struct dhcp_assignment *a)
977 {
978 uloop_timeout_cancel(&a->reconf_timer);
979 a->reconf_cnt = 0;
980 a->reconf_timer.cb = NULL;
981 }
982
983 static void valid_until_cb(struct uloop_timeout *event)
984 {
985 struct interface *iface;
986 time_t now = odhcpd_time();
987
988 avl_for_each_element(&interfaces, iface, avl) {
989 struct dhcp_assignment *a, *n;
990
991 if (iface->dhcpv6 != MODE_SERVER)
992 continue;
993
994 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
995 if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
996 free_assignment(a);
997 }
998 }
999 uloop_timeout_set(event, 1000);
1000 }
1001
1002 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
1003 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1004 struct interface *iface, bool request)
1005 {
1006 struct dhcpv6_ia_hdr o_ia = {
1007 .type = ia->type,
1008 .len = 0,
1009 .iaid = ia->iaid,
1010 .t1 = 0,
1011 .t2 = 0,
1012 };
1013 size_t ia_len = sizeof(o_ia);
1014 time_t now = odhcpd_time();
1015
1016 if (buflen < ia_len)
1017 return 0;
1018
1019 if (status) {
1020 struct __attribute__((packed)) {
1021 uint16_t type;
1022 uint16_t len;
1023 uint16_t val;
1024 } o_status = {
1025 .type = htons(DHCPV6_OPT_STATUS),
1026 .len = htons(sizeof(o_status) - 4),
1027 .val = htons(status),
1028 };
1029
1030 memcpy(buf + ia_len, &o_status, sizeof(o_status));
1031 ia_len += sizeof(o_status);
1032
1033 o_ia.len = htons(ia_len - 4);
1034 memcpy(buf, &o_ia, sizeof(o_ia));
1035
1036 return ia_len;
1037 }
1038
1039 if (a) {
1040 uint32_t leasetime, preferred_lt;
1041
1042 if (a->leasetime) {
1043 leasetime = a->leasetime;
1044 preferred_lt = a->leasetime;
1045 } else {
1046 leasetime = iface->dhcp_leasetime;
1047 preferred_lt = iface->preferred_lifetime;
1048 }
1049
1050 uint32_t valid_lt = leasetime;
1051
1052 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1053 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1054 size_t m = get_preferred_addr(addrs, addrlen);
1055
1056 for (size_t i = 0; i < addrlen; ++i) {
1057 uint32_t prefix_preferred_lt, prefix_valid_lt;
1058
1059 if (!valid_addr(&addrs[i], now))
1060 continue;
1061
1062 /* Filter Out Prefixes */
1063 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
1064 char addrbuf[INET6_ADDRSTRLEN];
1065 syslog(LOG_INFO, "Address %s filtered out on %s",
1066 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
1067 iface->name);
1068 continue;
1069 }
1070
1071 prefix_preferred_lt = addrs[i].preferred_lt;
1072 prefix_valid_lt = addrs[i].valid_lt;
1073
1074 if (prefix_preferred_lt != UINT32_MAX)
1075 prefix_preferred_lt -= now;
1076
1077 if (prefix_preferred_lt > preferred_lt)
1078 prefix_preferred_lt = preferred_lt;
1079
1080 if (prefix_valid_lt != UINT32_MAX)
1081 prefix_valid_lt -= now;
1082
1083 if (prefix_valid_lt > leasetime)
1084 prefix_valid_lt = leasetime;
1085
1086 if (prefix_preferred_lt > prefix_valid_lt)
1087 prefix_preferred_lt = prefix_valid_lt;
1088
1089 if (a->flags & OAF_DHCPV6_PD) {
1090 struct dhcpv6_ia_prefix o_ia_p = {
1091 .type = htons(DHCPV6_OPT_IA_PREFIX),
1092 .len = htons(sizeof(o_ia_p) - 4),
1093 .preferred_lt = htonl(prefix_preferred_lt),
1094 .valid_lt = htonl(prefix_valid_lt),
1095 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
1096 .addr = addrs[i].addr.in6,
1097 };
1098
1099 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1100 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
1101
1102 if (!valid_prefix_length(a, addrs[i].prefix))
1103 continue;
1104
1105 if (buflen < ia_len + sizeof(o_ia_p))
1106 return 0;
1107
1108 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1109 ia_len += sizeof(o_ia_p);
1110 }
1111
1112 if (a->flags & OAF_DHCPV6_NA) {
1113 struct dhcpv6_ia_addr o_ia_a = {
1114 .type = htons(DHCPV6_OPT_IA_ADDR),
1115 .len = htons(sizeof(o_ia_a) - 4),
1116 .addr = addrs[i].addr.in6,
1117 .preferred_lt = htonl(prefix_preferred_lt),
1118 .valid_lt = htonl(prefix_valid_lt)
1119 };
1120
1121 o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1122 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1123
1124 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
1125 continue;
1126
1127 if (buflen < ia_len + sizeof(o_ia_a))
1128 return 0;
1129
1130 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1131 ia_len += sizeof(o_ia_a);
1132 }
1133
1134 /* Calculate T1 / T2 based on non-deprecated addresses */
1135 if (prefix_preferred_lt > 0) {
1136 if (prefix_preferred_lt < preferred_lt)
1137 preferred_lt = prefix_preferred_lt;
1138
1139 if (prefix_valid_lt < valid_lt)
1140 valid_lt = prefix_valid_lt;
1141 }
1142 }
1143
1144 if (!INFINITE_VALID(a->valid_until))
1145 /* UINT32_MAX is RFC defined as infinite lease-time */
1146 a->valid_until = (valid_lt == UINT32_MAX) ? 0 : valid_lt + now;
1147
1148 if (!INFINITE_VALID(a->preferred_until))
1149 /* UINT32_MAX is RFC defined as infinite lease-time */
1150 a->preferred_until = (preferred_lt == UINT32_MAX) ? 0 : preferred_lt + now;
1151
1152 o_ia.t1 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 5 / 10);
1153 o_ia.t2 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 8 / 10);
1154
1155 if (!o_ia.t1)
1156 o_ia.t1 = htonl(1);
1157
1158 if (!o_ia.t2)
1159 o_ia.t2 = htonl(1);
1160 }
1161
1162 if (!request) {
1163 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1164 uint16_t otype, olen;
1165
1166 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1167 struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
1168 struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
1169 bool found = false;
1170
1171 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
1172 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
1173 continue;
1174
1175 if (a) {
1176 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1177 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1178
1179 for (size_t i = 0; i < addrlen; ++i) {
1180 struct in6_addr addr;
1181
1182 if (!valid_addr(&addrs[i], now))
1183 continue;
1184
1185 if (!valid_prefix_length(a, addrs[i].prefix))
1186 continue;
1187
1188 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1189 continue;
1190
1191 addr = addrs[i].addr.in6;
1192 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1193 addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1194 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1195
1196 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
1197 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
1198 found = true;
1199 } else {
1200 addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1201 addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1202
1203 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
1204 found = true;
1205 }
1206 }
1207 }
1208
1209 if (!found) {
1210 if (otype == DHCPV6_OPT_IA_PREFIX) {
1211 struct dhcpv6_ia_prefix o_ia_p = {
1212 .type = htons(DHCPV6_OPT_IA_PREFIX),
1213 .len = htons(sizeof(o_ia_p) - 4),
1214 .preferred_lt = 0,
1215 .valid_lt = 0,
1216 .prefix = ia_p->prefix,
1217 .addr = ia_p->addr,
1218 };
1219
1220 if (buflen < ia_len + sizeof(o_ia_p))
1221 return 0;
1222
1223 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1224 ia_len += sizeof(o_ia_p);
1225 } else {
1226 struct dhcpv6_ia_addr o_ia_a = {
1227 .type = htons(DHCPV6_OPT_IA_ADDR),
1228 .len = htons(sizeof(o_ia_a) - 4),
1229 .addr = ia_a->addr,
1230 .preferred_lt = 0,
1231 .valid_lt = 0,
1232 };
1233
1234 if (buflen < ia_len + sizeof(o_ia_a))
1235 continue;
1236
1237 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1238 ia_len += sizeof(o_ia_a);
1239 }
1240 }
1241 }
1242 }
1243
1244 o_ia.len = htons(ia_len - 4);
1245 memcpy(buf, &o_ia, sizeof(o_ia));
1246 return ia_len;
1247 }
1248
1249 struct log_ctxt {
1250 char *buf;
1251 int buf_len;
1252 int buf_idx;
1253 };
1254
1255 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
1256 _unused uint32_t valid_lt, void *arg)
1257 {
1258 struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1259 char addrbuf[INET6_ADDRSTRLEN];
1260
1261 inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1262 ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1263 "%s/%d ", addrbuf, prefix);
1264 }
1265
1266 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1267 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1268 {
1269 const char *type = "UNKNOWN";
1270 const char *status = "UNKNOWN";
1271
1272 switch (msgtype) {
1273 case DHCPV6_MSG_SOLICIT:
1274 type = "SOLICIT";
1275 break;
1276 case DHCPV6_MSG_REQUEST:
1277 type = "REQUEST";
1278 break;
1279 case DHCPV6_MSG_CONFIRM:
1280 type = "CONFIRM";
1281 break;
1282 case DHCPV6_MSG_RENEW:
1283 type = "RENEW";
1284 break;
1285 case DHCPV6_MSG_REBIND:
1286 type = "REBIND";
1287 break;
1288 case DHCPV6_MSG_RELEASE:
1289 type = "RELEASE";
1290 break;
1291 case DHCPV6_MSG_DECLINE:
1292 type = "DECLINE";
1293 break;
1294 }
1295
1296 switch (code) {
1297 case DHCPV6_STATUS_OK:
1298 status = "ok";
1299 break;
1300 case DHCPV6_STATUS_NOADDRSAVAIL:
1301 status = "no addresses available";
1302 break;
1303 case DHCPV6_STATUS_NOBINDING:
1304 status = "no binding";
1305 break;
1306 case DHCPV6_STATUS_NOTONLINK:
1307 status = "not on-link";
1308 break;
1309 case DHCPV6_STATUS_NOPREFIXAVAIL:
1310 status = "no prefix available";
1311 break;
1312 }
1313
1314 char leasebuf[256] = "";
1315
1316 if (a) {
1317 struct log_ctxt ctxt = {.buf = leasebuf,
1318 .buf_len = sizeof(leasebuf),
1319 .buf_idx = 0 };
1320
1321 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1322 }
1323
1324 syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1325 duidbuf, iface->name, status, leasebuf);
1326 }
1327
1328 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1329 struct interface *iface)
1330 {
1331 struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1332 size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1333 time_t now = odhcpd_time();
1334 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1335 uint16_t otype, olen;
1336 bool onlink = true;
1337
1338 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1339 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1340 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1341
1342 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1343 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1344 continue;
1345
1346 onlink = false;
1347 for (size_t i = 0; i < addrlen; ++i) {
1348 if (!valid_addr(&addrs[i], now))
1349 continue;
1350
1351 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1352 continue;
1353
1354 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1355 if (p->prefix < addrs[i].prefix ||
1356 odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1357 continue;
1358
1359 } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1360 continue;
1361
1362 onlink = true;
1363 }
1364
1365 if (!onlink)
1366 break;
1367 }
1368
1369 return onlink;
1370 }
1371
1372 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1373 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1374 {
1375 struct lease *l;
1376 struct dhcp_assignment *first = NULL;
1377 const struct dhcpv6_client_header *hdr = data;
1378 time_t now = odhcpd_time();
1379 uint16_t otype, olen, clid_len = 0;
1380 uint8_t *start = (uint8_t *)&hdr[1], *odata;
1381 uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1382 size_t hostname_len = 0, response_len = 0;
1383 bool notonlink = false, rapid_commit = false, accept_reconf = false;
1384 char duidbuf[261], hostname[256];
1385
1386 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1387 if (otype == DHCPV6_OPT_CLIENTID) {
1388 clid_data = odata;
1389 clid_len = olen;
1390
1391 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1392 memcpy(mac, &odata[8], sizeof(mac));
1393 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1394 memcpy(mac, &odata[4], sizeof(mac));
1395
1396 if (olen <= 130)
1397 odhcpd_hexlify(duidbuf, odata, olen);
1398 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1399 uint8_t fqdn_buf[256];
1400 memcpy(fqdn_buf, odata, olen);
1401 fqdn_buf[olen++] = 0;
1402
1403 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1404 hostname_len = strcspn(hostname, ".");
1405 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1406 accept_reconf = true;
1407 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1408 rapid_commit = true;
1409 }
1410
1411 if (!clid_data || !clid_len || clid_len > 130)
1412 goto out;
1413
1414 l = config_find_lease_by_duid(clid_data, clid_len);
1415 if (!l)
1416 l = config_find_lease_by_mac(mac);
1417
1418 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1419 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1420 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1421 bool ia_addr_present = false;
1422 if (!is_pd && !is_na)
1423 continue;
1424
1425 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1426 size_t ia_response_len = 0;
1427 uint8_t reqlen = (is_pd) ? 62 : 128;
1428 uint32_t reqhint = 0;
1429
1430 /* Parse request hint for IA-PD */
1431 if (is_pd) {
1432 uint8_t *sdata;
1433 uint16_t stype, slen;
1434 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1435 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1436 continue;
1437
1438 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1439 if (p->prefix) {
1440 reqlen = p->prefix;
1441 reqhint = ntohl(p->addr.s6_addr32[1]);
1442 if (reqlen > 32 && reqlen <= 64)
1443 reqhint &= (1U << (64 - reqlen)) - 1;
1444 }
1445 }
1446
1447 if (reqlen > 64)
1448 reqlen = 64;
1449
1450 /*
1451 * A requesting router can include a desired prefix length for its
1452 * delegation. The delegating router (us) is not required to honor
1453 * the hint (RFC3633, section 11.2, we MAY choose to use the
1454 * information in the option; RFC8168, section 3.2 has several SHOULDs
1455 * about desired choices for selecting a prefix to delegate).
1456 *
1457 * We support a policy setting to conserve prefix space, which purposely
1458 * assigns prefixes that might not match the requesting router's hint.
1459 *
1460 * If the minimum prefix length is set in this interface's
1461 * configuration, we use it as a floor for the requested (hinted)
1462 * prefix length. This allows us to conserve prefix space so that
1463 * any single router can't grab too much of it. Consider if we have
1464 * an interface with a /56 prefix. A requesting router could ask for
1465 * a /58 and take 1/4 of our total address space. But if we set a
1466 * minimum of /60, we can limit each requesting router to get only
1467 * 1/16 of our total address space.
1468 */
1469 if (iface->dhcpv6_pd_min_len && reqlen < iface->dhcpv6_pd_min_len) {
1470 syslog(LOG_INFO, "clamping requested PD from %d to %d",
1471 reqlen, iface->dhcpv6_pd_min_len);
1472 reqlen = iface->dhcpv6_pd_min_len;
1473 }
1474 } else if (is_na) {
1475 uint8_t *sdata;
1476 uint16_t stype, slen;
1477 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1478 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1479 continue;
1480
1481 ia_addr_present = true;
1482 }
1483 }
1484
1485 /* Find assignment */
1486 struct dhcp_assignment *c, *a = NULL;
1487 list_for_each_entry(c, &iface->ia_assignments, head) {
1488 if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1489 c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1490 ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1491 a = c;
1492
1493 /* Reset state */
1494 if (a->flags & OAF_BOUND)
1495 apply_lease(a, false);
1496
1497 stop_reconf(a);
1498 break;
1499 }
1500 }
1501
1502 if (l && a && a->lease != l) {
1503 free_assignment(a);
1504 a = NULL;
1505 }
1506
1507 /* Generic message handling */
1508 uint16_t status = DHCPV6_STATUS_OK;
1509 if (a && a->managed_size < 0)
1510 return -1;
1511
1512 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1513 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1514 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1515 bool assigned = !!a;
1516
1517 if (!a) {
1518 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1519 (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1520 /* Create new binding */
1521 a = alloc_assignment(clid_len);
1522
1523 if (a) {
1524 a->clid_len = clid_len;
1525 memcpy(a->clid_data, clid_data, clid_len);
1526 a->iaid = ia->iaid;
1527 a->length = reqlen;
1528 a->peer = *addr;
1529 if (is_na)
1530 a->assigned_host_id = l ? l->hostid : 0;
1531 else
1532 a->assigned_subnet_id = reqhint;
1533 a->valid_until = now;
1534 a->preferred_until = now;
1535 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1536 a->iface = iface;
1537 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1538
1539 if (first)
1540 memcpy(a->key, first->key, sizeof(a->key));
1541 else
1542 odhcpd_urandom(a->key, sizeof(a->key));
1543
1544 if (is_pd && iface->dhcpv6_pd)
1545 while (!(assigned = assign_pd(iface, a)) &&
1546 !a->managed_size && ++a->length <= 64);
1547 else if (is_na && iface->dhcpv6_na)
1548 assigned = assign_na(iface, a);
1549
1550 if (l && assigned) {
1551 a->flags |= OAF_STATIC;
1552
1553 if (l->hostname)
1554 a->hostname = strdup(l->hostname);
1555
1556 if (l->leasetime)
1557 a->leasetime = l->leasetime;
1558
1559 list_add(&a->lease_list, &l->assignments);
1560 a->lease = l;
1561 }
1562
1563 if (a->managed_size && !assigned)
1564 return -1;
1565 }
1566 }
1567 }
1568
1569 if (!assigned || iface->addr6_len == 0)
1570 /* Set error status */
1571 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1572 else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1573 /* Send NOTONLINK status for the IA */
1574 status = DHCPV6_STATUS_NOTONLINK;
1575 assigned = false;
1576 } else if (accept_reconf && assigned && !first &&
1577 hdr->msg_type != DHCPV6_MSG_REBIND) {
1578 size_t handshake_len = 4;
1579 buf[0] = 0;
1580 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1581 buf[2] = 0;
1582 buf[3] = 0;
1583
1584 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1585 struct dhcpv6_auth_reconfigure auth = {
1586 htons(DHCPV6_OPT_AUTH),
1587 htons(sizeof(auth) - 4),
1588 3, 1, 0,
1589 {htonl(time(NULL)), htonl(++serial)},
1590 1,
1591 {0}
1592 };
1593 memcpy(auth.key, a->key, sizeof(a->key));
1594 memcpy(buf + handshake_len, &auth, sizeof(auth));
1595 handshake_len += sizeof(auth);
1596 }
1597
1598
1599 buf += handshake_len;
1600 buflen -= handshake_len;
1601 response_len += handshake_len;
1602
1603 first = a;
1604 }
1605
1606 ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1607 hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1608
1609 /* Was only a solicitation: mark binding for removal */
1610 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1611 a->flags &= ~OAF_BOUND;
1612 a->flags |= OAF_TENTATIVE;
1613
1614 /* Keep tentative assignment around for 60 seconds */
1615 a->valid_until = now + 60;
1616
1617 } else if (assigned &&
1618 ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1619 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1620 hdr->msg_type == DHCPV6_MSG_REBIND)) {
1621 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1622 a->hostname = realloc(a->hostname, hostname_len + 1);
1623 if (a->hostname) {
1624 memcpy(a->hostname, hostname, hostname_len);
1625 a->hostname[hostname_len] = 0;
1626
1627 if (odhcpd_valid_hostname(a->hostname))
1628 a->flags &= ~OAF_BROKEN_HOSTNAME;
1629 else
1630 a->flags |= OAF_BROKEN_HOSTNAME;
1631 }
1632 }
1633 a->accept_reconf = accept_reconf;
1634 a->flags &= ~OAF_TENTATIVE;
1635 a->flags |= OAF_BOUND;
1636 apply_lease(a, true);
1637 } else if (!assigned && a && a->managed_size == 0) {
1638 /* Cleanup failed assignment */
1639 free_assignment(a);
1640 a = NULL;
1641 }
1642 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1643 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1644 hdr->msg_type == DHCPV6_MSG_REBIND ||
1645 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1646 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1647 status = DHCPV6_STATUS_NOBINDING;
1648 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1649 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1650 hdr->msg_type == DHCPV6_MSG_REBIND) {
1651 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1652 if (a) {
1653 a->flags |= OAF_BOUND;
1654 apply_lease(a, true);
1655 }
1656 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1657 a->valid_until = now - 1;
1658 } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1659 a->flags &= ~OAF_BOUND;
1660
1661 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
1662 memset(a->clid_data, 0, a->clid_len);
1663 a->valid_until = now + 3600; /* Block address for 1h */
1664 } else
1665 a->valid_until = now - 1;
1666 }
1667 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1668 if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1669 notonlink = true;
1670 break;
1671 }
1672
1673 if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1674 response_len = 0;
1675 goto out;
1676 }
1677 }
1678
1679 buf += ia_response_len;
1680 buflen -= ia_response_len;
1681 response_len += ia_response_len;
1682 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1683 }
1684
1685 switch (hdr->msg_type) {
1686 case DHCPV6_MSG_RELEASE:
1687 case DHCPV6_MSG_DECLINE:
1688 case DHCPV6_MSG_CONFIRM:
1689 if (response_len + 6 < buflen) {
1690 buf[0] = 0;
1691 buf[1] = DHCPV6_OPT_STATUS;
1692 buf[2] = 0;
1693 buf[3] = 2;
1694 buf[4] = 0;
1695 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1696 response_len += 6;
1697 }
1698 break;
1699
1700 default:
1701 break;
1702 }
1703
1704 dhcpv6_ia_write_statefile();
1705
1706 out:
1707 return response_len;
1708 }
OpenWrt DHCP Server