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dhcpv6-ia: make tmp lease file hidden
[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 > (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 > addrs[m].preferred ||
132 (addrs[i].preferred == addrs[m].preferred &&
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 pref, valid;
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 pref = addrs[i].preferred;
246 valid = addrs[i].valid;
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 (pref > (uint32_t)c->preferred_until)
263 pref = c->preferred_until;
264
265 if (pref > (uint32_t)c->valid_until)
266 pref = c->valid_until;
267
268 if (pref != UINT32_MAX)
269 pref -= now;
270
271 if (valid > (uint32_t)c->valid_until)
272 valid = c->valid_until;
273
274 if (valid != UINT32_MAX)
275 valid -= now;
276
277 func(&addr, prefix, pref, valid, 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_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
292 _unused uint32_t valid, void *arg)
293 {
294 struct write_ctxt *ctxt = (struct write_ctxt *)arg;
295 char ipbuf[INET6_ADDRSTRLEN];
296
297 inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
298
299 if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
300 !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
301 fputs(ipbuf, ctxt->fp);
302
303 char b[256];
304 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
305 ctxt->iface->search, b, sizeof(b)) > 0)
306 fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
307
308 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
309 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
310 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
311 }
312
313 ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
314 "%s/%d ", ipbuf, prefix);
315 }
316
317 void dhcpv6_ia_write_statefile(void)
318 {
319 struct write_ctxt ctxt;
320
321 md5_begin(&ctxt.md5);
322
323 if (config.dhcp_statefile) {
324 unsigned statefile_strlen = strlen(config.dhcp_statefile) + 1;
325 unsigned tmp_statefile_strlen = statefile_strlen + 1; /* space for . */
326 char *tmp_statefile = alloca(tmp_statefile_strlen);
327
328 char *dir_statefile;
329 char *base_statefile;
330 char *pdir_statefile;
331 char *pbase_statefile;
332
333 time_t now = odhcpd_time(), wall_time = time(NULL);
334 int fd, ret;
335 char leasebuf[512];
336
337 dir_statefile = strndup(config.dhcp_statefile, statefile_strlen);
338 base_statefile = strndup(config.dhcp_statefile, statefile_strlen);
339
340 pdir_statefile = dirname(dir_statefile);
341 pbase_statefile = basename(base_statefile);
342
343 snprintf(tmp_statefile, tmp_statefile_strlen, "%s/.%s", pdir_statefile, pbase_statefile);
344
345 free(dir_statefile);
346 free(base_statefile);
347
348 fd = open(tmp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
349 if (fd < 0)
350 return;
351
352 ret = lockf(fd, F_LOCK, 0);
353 if (ret < 0) {
354 close(fd);
355 return;
356 }
357
358 if (ftruncate(fd, 0) < 0) {}
359
360 ctxt.fp = fdopen(fd, "w");
361 if (!ctxt.fp) {
362 close(fd);
363 return;
364 }
365
366 ctxt.buf = leasebuf;
367 ctxt.buf_len = sizeof(leasebuf);
368
369 avl_for_each_element(&interfaces, ctxt.iface, avl) {
370 if (ctxt.iface->dhcpv6 != MODE_SERVER &&
371 ctxt.iface->dhcpv4 != MODE_SERVER)
372 continue;
373
374 if (ctxt.iface->dhcpv6 == MODE_SERVER) {
375 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
376 if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
377 continue;
378
379 char duidbuf[264];
380
381 odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
382
383 /* iface DUID iaid hostname lifetime assigned_host_id length [addrs...] */
384 ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" ",
385 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
386 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
387 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
388 (ctxt.c->valid_until > now ?
389 (int64_t)(ctxt.c->valid_until - now + wall_time) :
390 (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
391
392 if (ctxt.c->flags & OAF_DHCPV6_NA)
393 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
394 "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
395 else
396 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
397 "%" PRIx32" %u ", ctxt.c->assigned_subnet_id, (unsigned)ctxt.c->length);
398
399 if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
400 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
401 dhcpv6_write_ia_addr, &ctxt);
402
403 ctxt.buf[ctxt.buf_idx - 1] = '\n';
404 fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
405 }
406 }
407
408 if (ctxt.iface->dhcpv4 == MODE_SERVER) {
409 struct dhcp_assignment *c;
410
411 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
412 if (!(c->flags & OAF_BOUND))
413 continue;
414
415 char ipbuf[INET6_ADDRSTRLEN];
416 char duidbuf[16];
417 odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
418
419 /* iface DUID iaid hostname lifetime assigned length [addrs...] */
420 ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
421 ctxt.iface->ifname, duidbuf,
422 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
423 (c->hostname ? c->hostname : "-"),
424 (c->valid_until > now ?
425 (int64_t)(c->valid_until - now + wall_time) :
426 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
427 ntohl(c->addr));
428
429 struct in_addr addr = {.s_addr = c->addr};
430 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
431
432 if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
433 fputs(ipbuf, ctxt.fp);
434
435 char b[256];
436 if (dn_expand(ctxt.iface->search,
437 ctxt.iface->search + ctxt.iface->search_len,
438 ctxt.iface->search, b, sizeof(b)) > 0)
439 fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
440
441 fprintf(ctxt.fp, "\t%s\n", c->hostname);
442 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
443 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
444 }
445
446 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
447 ctxt.buf_len - ctxt.buf_idx,
448 "%s/32 ", ipbuf);
449 ctxt.buf[ctxt.buf_idx - 1] = '\n';
450 fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
451 }
452 }
453 }
454
455 fclose(ctxt.fp);
456
457 uint8_t newmd5[16];
458 md5_end(newmd5, &ctxt.md5);
459
460 if (memcmp(newmd5, statemd5, sizeof(newmd5))) {
461 memcpy(statemd5, newmd5, sizeof(statemd5));
462 rename(tmp_statefile, config.dhcp_statefile);
463
464 if (config.dhcp_cb) {
465 char *argv[2] = {config.dhcp_cb, NULL};
466 if (!vfork()) {
467 execv(argv[0], argv);
468 _exit(128);
469 }
470 }
471 } else {
472 unlink(tmp_statefile);
473 }
474 }
475 }
476
477 static void __apply_lease(struct dhcp_assignment *a,
478 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
479 {
480 if (a->flags & OAF_DHCPV6_NA)
481 return;
482
483 for (ssize_t i = 0; i < addr_len; ++i) {
484 struct in6_addr prefix;
485
486 if (ADDR_MATCH_PIO_FILTER(&addrs[i], a->iface))
487 continue;
488
489 prefix = addrs[i].addr.in6;
490 prefix.s6_addr32[1] |= htonl(a->assigned_subnet_id);
491 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
492 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
493 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
494 }
495 }
496
497 static void apply_lease(struct dhcp_assignment *a, bool add)
498 {
499 struct interface *iface = a->iface;
500 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
501 ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
502
503 __apply_lease(a, addrs, addrlen, add);
504 }
505
506 /* Set border assignment size based on the IPv6 address prefixes */
507 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
508 {
509 time_t now = odhcpd_time();
510 int minprefix = -1;
511
512 for (size_t i = 0; i < iface->addr6_len; ++i) {
513 struct odhcpd_ipaddr *addr = &iface->addr6[i];
514
515 if (ADDR_MATCH_PIO_FILTER(addr, iface))
516 continue;
517
518 if (addr->preferred > (uint32_t)now &&
519 addr->prefix < 64 &&
520 addr->prefix > minprefix)
521 minprefix = addr->prefix;
522 }
523
524 if (minprefix > 32 && minprefix <= 64)
525 b->assigned_subnet_id = 1U << (64 - minprefix);
526 else
527 b->assigned_subnet_id = 0;
528 }
529
530 /* More data was received from TCP connection */
531 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
532 {
533 struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
534 struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
535 time_t now = odhcpd_time();
536 bool first = c->managed_size < 0;
537
538 for (;;) {
539 int pending;
540 char *data = ustream_get_read_buf(s, &pending);
541 char *end = memmem(data, pending, "\n\n", 2);
542
543 if (!end)
544 break;
545
546 end += 2;
547 end[-1] = 0;
548
549 c->managed_size = 0;
550 if (c->accept_reconf)
551 c->reconf_cnt = 1;
552
553 char *saveptr;
554 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
555 c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
556 struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
557
558 char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
559 if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
560 continue;
561
562 x = strtok_r(NULL, ",", &saveptr2);
563 if (sscanf(x, "%hhu", &n->prefix) < 1)
564 continue;
565
566 x = strtok_r(NULL, ",", &saveptr2);
567 if (sscanf(x, "%u", &n->preferred) < 1)
568 continue;
569
570 x = strtok_r(NULL, ",", &saveptr2);
571 if (sscanf(x, "%u", &n->valid) < 1)
572 continue;
573
574 if (n->preferred > n->valid)
575 continue;
576
577 if (UINT32_MAX - now < n->preferred)
578 n->preferred = UINT32_MAX;
579 else
580 n->preferred += now;
581
582 if (UINT32_MAX - now < n->valid)
583 n->valid = UINT32_MAX;
584 else
585 n->valid += now;
586
587 n->dprefix = 0;
588
589 ++c->managed_size;
590 }
591
592 ustream_consume(s, end - data);
593 }
594
595 if (first && c->managed_size == 0)
596 free_assignment(c);
597 else if (first)
598 c->valid_until = now + 150;
599 }
600
601
602 /* TCP transmission has ended, either because of success or timeout or other error */
603 static void managed_handle_pd_done(struct ustream *s)
604 {
605 struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
606 struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
607
608 c->valid_until = odhcpd_time() + 15;
609
610 c->managed_size = 0;
611
612 if (c->accept_reconf)
613 c->reconf_cnt = 1;
614 }
615
616 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
617 {
618 struct dhcp_assignment *c;
619
620 if (iface->dhcpv6_pd_manager[0]) {
621 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
622 if (fd >= 0) {
623 struct pollfd pfd = { .fd = fd, .events = POLLIN };
624 char iaidbuf[298];
625
626 odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
627
628 assign->managed_sock.stream.notify_read = managed_handle_pd_data;
629 assign->managed_sock.stream.notify_state = managed_handle_pd_done;
630 ustream_fd_init(&assign->managed_sock, fd);
631 ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
632 iaidbuf, assign->iaid, assign->length);
633 ustream_write_pending(&assign->managed_sock.stream);
634 assign->managed_size = -1;
635
636 assign->valid_until = odhcpd_time() + 15;
637
638 list_add(&assign->head, &iface->ia_assignments);
639
640 /* Wait initial period of up to 250ms for immediate assignment */
641 if (poll(&pfd, 1, 250) < 0) {
642 syslog(LOG_ERR, "poll(): %m");
643 return false;
644 }
645
646 managed_handle_pd_data(&assign->managed_sock.stream, 0);
647
648 if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
649 return true;
650 }
651
652 return false;
653 } else if (iface->addr6_len < 1)
654 return false;
655
656 /* Try honoring the hint first */
657 uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
658 if (assign->assigned_subnet_id) {
659 list_for_each_entry(c, &iface->ia_assignments, head) {
660 if (c->flags & OAF_DHCPV6_NA)
661 continue;
662
663 if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
664 list_add_tail(&assign->head, &c->head);
665
666 if (assign->flags & OAF_BOUND)
667 apply_lease(assign, true);
668
669 return true;
670 }
671
672 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
673 }
674 }
675
676 /* Fallback to a variable assignment */
677 current = 1;
678 list_for_each_entry(c, &iface->ia_assignments, head) {
679 if (c->flags & OAF_DHCPV6_NA)
680 continue;
681
682 current = (current + asize) & (~asize);
683
684 if (current + asize < c->assigned_subnet_id) {
685 assign->assigned_subnet_id = current;
686 list_add_tail(&assign->head, &c->head);
687
688 if (assign->flags & OAF_BOUND)
689 apply_lease(assign, true);
690
691 return true;
692 }
693
694 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
695 }
696
697 return false;
698 }
699
700 /* Check iid against reserved IPv6 interface identifiers.
701 Refer to:
702 http://www.iana.org/assignments/ipv6-interface-ids */
703 static bool is_reserved_ipv6_iid(uint64_t iid)
704 {
705 if (iid == 0x0000000000000000)
706 /* Subnet-Router Anycast [RFC4291] */
707 return true;
708
709 if ((iid & 0xFFFFFFFFFF000000) == 0x02005EFFFE000000)
710 /* Reserved IPv6 Interface Identifiers corresponding
711 to the IANA Ethernet Block [RFC4291] */
712 return true;
713
714 if ((iid & 0xFFFFFFFFFFFFFF80) == 0xFDFFFFFFFFFFFF80)
715 /* Reserved Subnet Anycast Addresses [RFC2526] */
716 return true;
717
718 return false;
719 }
720
721 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
722 {
723 struct dhcp_assignment *c;
724 uint32_t seed = 0;
725
726 /* Preconfigured assignment by static lease */
727 if (a->assigned_host_id) {
728 list_for_each_entry(c, &iface->ia_assignments, head) {
729 if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
730 list_add_tail(&a->head, &c->head);
731 return true;
732 } else if (c->assigned_host_id == a->assigned_host_id)
733 return false;
734 }
735 }
736
737 /* Seed RNG with checksum of DUID */
738 for (size_t i = 0; i < a->clid_len; ++i)
739 seed += a->clid_data[i];
740 srandom(seed);
741
742 /* Try to assign up to 100x */
743 for (size_t i = 0; i < 100; ++i) {
744 uint64_t try;
745
746 if (iface->dhcpv6_hostid_len > 32) {
747 uint32_t mask_high;
748
749 if (iface->dhcpv6_hostid_len >= 64)
750 mask_high = UINT32_MAX;
751 else
752 mask_high = (1 << (iface->dhcpv6_hostid_len - 32)) - 1;
753
754 do {
755 try = (uint32_t)random();
756 try |= (uint64_t)((uint32_t)random() & mask_high) << 32;
757 } while (try < 0x100);
758 } else {
759 uint32_t mask_low;
760
761 if (iface->dhcpv6_hostid_len == 32)
762 mask_low = UINT32_MAX;
763 else
764 mask_low = (1 << iface->dhcpv6_hostid_len) - 1;
765 do try = ((uint32_t)random()) & mask_low; while (try < 0x100);
766 }
767
768 if (is_reserved_ipv6_iid(try))
769 continue;
770
771 if (config_find_lease_by_hostid(try))
772 continue;
773
774 list_for_each_entry(c, &iface->ia_assignments, head) {
775 if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
776 a->assigned_host_id = try;
777 list_add_tail(&a->head, &c->head);
778 return true;
779 } else if (c->assigned_host_id == try)
780 break;
781 }
782 }
783
784 return false;
785 }
786
787 static void handle_addrlist_change(struct netevent_handler_info *info)
788 {
789 struct interface *iface = info->iface;
790 struct dhcp_assignment *c, *d, *border = list_last_entry(
791 &iface->ia_assignments, struct dhcp_assignment, head);
792 struct list_head reassign = LIST_HEAD_INIT(reassign);
793 time_t now = odhcpd_time();
794
795 list_for_each_entry(c, &iface->ia_assignments, head) {
796 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
797 && (c->flags & OAF_BOUND))
798 __apply_lease(c, info->addrs_old.addrs,
799 info->addrs_old.len, false);
800 }
801
802 set_border_assignment_size(iface, border);
803
804 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
805 if (c->clid_len == 0 ||
806 !(c->flags & OAF_DHCPV6_PD) ||
807 (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
808 c->managed_size)
809 continue;
810
811 if (c->assigned_subnet_id >= border->assigned_subnet_id)
812 list_move(&c->head, &reassign);
813 else if (c->flags & OAF_BOUND)
814 apply_lease(c, true);
815
816 if (c->accept_reconf && c->reconf_cnt == 0) {
817 struct dhcp_assignment *a;
818
819 start_reconf(c);
820
821 /* Leave all other assignments of that client alone */
822 list_for_each_entry(a, &iface->ia_assignments, head)
823 if (a != c && a->clid_len == c->clid_len &&
824 !memcmp(a->clid_data, c->clid_data, a->clid_len))
825 a->reconf_cnt = INT_MAX;
826 }
827 }
828
829 while (!list_empty(&reassign)) {
830 c = list_first_entry(&reassign, struct dhcp_assignment, head);
831 list_del_init(&c->head);
832 if (!assign_pd(iface, c))
833 free_assignment(c);
834 }
835
836 dhcpv6_ia_write_statefile();
837 }
838
839 static void reconf_timeout_cb(struct uloop_timeout *event)
840 {
841 struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
842
843 if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
844 send_reconf(a);
845 uloop_timeout_set(&a->reconf_timer,
846 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
847 a->reconf_cnt++;
848 } else
849 stop_reconf(a);
850 }
851
852 static void start_reconf(struct dhcp_assignment *a)
853 {
854 uloop_timeout_set(&a->reconf_timer,
855 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
856 a->reconf_timer.cb = reconf_timeout_cb;
857 a->reconf_cnt++;
858
859 send_reconf(a);
860 }
861
862 static void stop_reconf(struct dhcp_assignment *a)
863 {
864 uloop_timeout_cancel(&a->reconf_timer);
865 a->reconf_cnt = 0;
866 a->reconf_timer.cb = NULL;
867 }
868
869 static void valid_until_cb(struct uloop_timeout *event)
870 {
871 struct interface *iface;
872 time_t now = odhcpd_time();
873
874 avl_for_each_element(&interfaces, iface, avl) {
875 struct dhcp_assignment *a, *n;
876
877 if (iface->dhcpv6 != MODE_SERVER)
878 continue;
879
880 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
881 if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
882 free_assignment(a);
883 }
884 }
885 uloop_timeout_set(event, 1000);
886 }
887
888 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
889 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
890 struct interface *iface, bool request)
891 {
892 struct dhcpv6_ia_hdr o_ia = {
893 .type = ia->type,
894 .len = 0,
895 .iaid = ia->iaid,
896 .t1 = 0,
897 .t2 = 0,
898 };
899 size_t ia_len = sizeof(o_ia);
900 time_t now = odhcpd_time();
901
902 if (buflen < ia_len)
903 return 0;
904
905 if (status) {
906 struct __attribute__((packed)) {
907 uint16_t type;
908 uint16_t len;
909 uint16_t val;
910 } o_status = {
911 .type = htons(DHCPV6_OPT_STATUS),
912 .len = htons(sizeof(o_status) - 4),
913 .val = htons(status),
914 };
915
916 memcpy(buf + ia_len, &o_status, sizeof(o_status));
917 ia_len += sizeof(o_status);
918
919 o_ia.len = htons(ia_len - 4);
920 memcpy(buf, &o_ia, sizeof(o_ia));
921
922 return ia_len;
923 }
924
925 if (a) {
926 uint32_t leasetime, pref;
927
928 if (a->leasetime) {
929 leasetime = a->leasetime;
930 pref = a->leasetime;
931 } else {
932 leasetime = iface->dhcp_leasetime;
933 pref = iface->preferred_lifetime;
934 }
935
936 uint32_t valid = leasetime;
937
938 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
939 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
940 size_t m = get_preferred_addr(addrs, addrlen);
941
942 for (size_t i = 0; i < addrlen; ++i) {
943 uint32_t prefix_pref, prefix_valid;
944
945 if (!valid_addr(&addrs[i], now))
946 continue;
947
948 /* Filter Out Prefixes */
949 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
950 char addrbuf[INET6_ADDRSTRLEN];
951 syslog(LOG_INFO, "Address %s filtered out on %s",
952 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
953 iface->name);
954 continue;
955 }
956
957 prefix_pref = addrs[i].preferred;
958 prefix_valid = addrs[i].valid;
959
960 if (prefix_pref != UINT32_MAX)
961 prefix_pref -= now;
962
963 if (prefix_pref > pref)
964 prefix_pref = pref;
965
966 if (prefix_valid != UINT32_MAX)
967 prefix_valid -= now;
968
969 if (prefix_valid > leasetime)
970 prefix_valid = leasetime;
971
972 if (prefix_pref > prefix_valid)
973 prefix_pref = prefix_valid;
974
975 if (a->flags & OAF_DHCPV6_PD) {
976 struct dhcpv6_ia_prefix o_ia_p = {
977 .type = htons(DHCPV6_OPT_IA_PREFIX),
978 .len = htons(sizeof(o_ia_p) - 4),
979 .preferred = htonl(prefix_pref),
980 .valid = htonl(prefix_valid),
981 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
982 .addr = addrs[i].addr.in6,
983 };
984
985 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
986 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
987
988 if (!valid_prefix_length(a, addrs[i].prefix))
989 continue;
990
991 if (buflen < ia_len + sizeof(o_ia_p))
992 return 0;
993
994 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
995 ia_len += sizeof(o_ia_p);
996 }
997
998 if (a->flags & OAF_DHCPV6_NA) {
999 struct dhcpv6_ia_addr o_ia_a = {
1000 .type = htons(DHCPV6_OPT_IA_ADDR),
1001 .len = htons(sizeof(o_ia_a) - 4),
1002 .addr = addrs[i].addr.in6,
1003 .preferred = htonl(prefix_pref),
1004 .valid = htonl(prefix_valid)
1005 };
1006
1007 o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1008 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1009
1010 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
1011 continue;
1012
1013 if (buflen < ia_len + sizeof(o_ia_a))
1014 return 0;
1015
1016 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1017 ia_len += sizeof(o_ia_a);
1018 }
1019
1020 /* Calculate T1 / T2 based on non-deprecated addresses */
1021 if (prefix_pref > 0) {
1022 if (prefix_pref < pref)
1023 pref = prefix_pref;
1024
1025 if (prefix_valid < valid)
1026 valid = prefix_valid;
1027 }
1028 }
1029
1030 if (!INFINITE_VALID(a->valid_until))
1031 /* UINT32_MAX is considered as infinite leasetime */
1032 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
1033
1034 if (!INFINITE_VALID(a->preferred_until))
1035 /* UINT32_MAX is considered as infinite leasetime */
1036 a->preferred_until = (pref == UINT32_MAX) ? 0 : pref + now;
1037
1038 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
1039 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
1040
1041 if (!o_ia.t1)
1042 o_ia.t1 = htonl(1);
1043
1044 if (!o_ia.t2)
1045 o_ia.t2 = htonl(1);
1046 }
1047
1048 if (!request) {
1049 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1050 uint16_t otype, olen;
1051
1052 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1053 struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
1054 struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
1055 bool found = false;
1056
1057 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
1058 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
1059 continue;
1060
1061 if (a) {
1062 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1063 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1064
1065 for (size_t i = 0; i < addrlen; ++i) {
1066 struct in6_addr addr;
1067
1068 if (!valid_addr(&addrs[i], now))
1069 continue;
1070
1071 if (!valid_prefix_length(a, addrs[i].prefix))
1072 continue;
1073
1074 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1075 continue;
1076
1077 addr = addrs[i].addr.in6;
1078 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1079 addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1080 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1081
1082 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
1083 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
1084 found = true;
1085 } else {
1086 addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1087 addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1088
1089 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
1090 found = true;
1091 }
1092 }
1093 }
1094
1095 if (!found) {
1096 if (otype == DHCPV6_OPT_IA_PREFIX) {
1097 struct dhcpv6_ia_prefix o_ia_p = {
1098 .type = htons(DHCPV6_OPT_IA_PREFIX),
1099 .len = htons(sizeof(o_ia_p) - 4),
1100 .preferred = 0,
1101 .valid = 0,
1102 .prefix = ia_p->prefix,
1103 .addr = ia_p->addr,
1104 };
1105
1106 if (buflen < ia_len + sizeof(o_ia_p))
1107 return 0;
1108
1109 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1110 ia_len += sizeof(o_ia_p);
1111 } else {
1112 struct dhcpv6_ia_addr o_ia_a = {
1113 .type = htons(DHCPV6_OPT_IA_ADDR),
1114 .len = htons(sizeof(o_ia_a) - 4),
1115 .addr = ia_a->addr,
1116 .preferred = 0,
1117 .valid = 0,
1118 };
1119
1120 if (buflen < ia_len + sizeof(o_ia_a))
1121 continue;
1122
1123 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1124 ia_len += sizeof(o_ia_a);
1125 }
1126 }
1127 }
1128 }
1129
1130 o_ia.len = htons(ia_len - 4);
1131 memcpy(buf, &o_ia, sizeof(o_ia));
1132 return ia_len;
1133 }
1134
1135 struct log_ctxt {
1136 char *buf;
1137 int buf_len;
1138 int buf_idx;
1139 };
1140
1141 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1142 _unused uint32_t valid, void *arg)
1143 {
1144 struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1145 char addrbuf[INET6_ADDRSTRLEN];
1146
1147 inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1148 ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1149 "%s/%d ", addrbuf, prefix);
1150 }
1151
1152 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1153 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1154 {
1155 const char *type = "UNKNOWN";
1156 const char *status = "UNKNOWN";
1157
1158 switch (msgtype) {
1159 case DHCPV6_MSG_SOLICIT:
1160 type = "SOLICIT";
1161 break;
1162 case DHCPV6_MSG_REQUEST:
1163 type = "REQUEST";
1164 break;
1165 case DHCPV6_MSG_CONFIRM:
1166 type = "CONFIRM";
1167 break;
1168 case DHCPV6_MSG_RENEW:
1169 type = "RENEW";
1170 break;
1171 case DHCPV6_MSG_REBIND:
1172 type = "REBIND";
1173 break;
1174 case DHCPV6_MSG_RELEASE:
1175 type = "RELEASE";
1176 break;
1177 case DHCPV6_MSG_DECLINE:
1178 type = "DECLINE";
1179 break;
1180 }
1181
1182 switch (code) {
1183 case DHCPV6_STATUS_OK:
1184 status = "ok";
1185 break;
1186 case DHCPV6_STATUS_NOADDRSAVAIL:
1187 status = "no addresses available";
1188 break;
1189 case DHCPV6_STATUS_NOBINDING:
1190 status = "no binding";
1191 break;
1192 case DHCPV6_STATUS_NOTONLINK:
1193 status = "not on-link";
1194 break;
1195 case DHCPV6_STATUS_NOPREFIXAVAIL:
1196 status = "no prefix available";
1197 break;
1198 }
1199
1200 char leasebuf[256] = "";
1201
1202 if (a) {
1203 struct log_ctxt ctxt = {.buf = leasebuf,
1204 .buf_len = sizeof(leasebuf),
1205 .buf_idx = 0 };
1206
1207 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1208 }
1209
1210 syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1211 duidbuf, iface->name, status, leasebuf);
1212 }
1213
1214 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1215 struct interface *iface)
1216 {
1217 struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1218 size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1219 time_t now = odhcpd_time();
1220 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1221 uint16_t otype, olen;
1222 bool onlink = true;
1223
1224 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1225 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1226 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1227
1228 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1229 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1230 continue;
1231
1232 onlink = false;
1233 for (size_t i = 0; i < addrlen; ++i) {
1234 if (!valid_addr(&addrs[i], now))
1235 continue;
1236
1237 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1238 continue;
1239
1240 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1241 if (p->prefix < addrs[i].prefix ||
1242 odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1243 continue;
1244
1245 } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1246 continue;
1247
1248 onlink = true;
1249 }
1250
1251 if (!onlink)
1252 break;
1253 }
1254
1255 return onlink;
1256 }
1257
1258 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1259 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1260 {
1261 struct lease *l;
1262 struct dhcp_assignment *first = NULL;
1263 const struct dhcpv6_client_header *hdr = data;
1264 time_t now = odhcpd_time();
1265 uint16_t otype, olen, clid_len = 0;
1266 uint8_t *start = (uint8_t *)&hdr[1], *odata;
1267 uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1268 size_t hostname_len = 0, response_len = 0;
1269 bool notonlink = false, rapid_commit = false, accept_reconf = false;
1270 char duidbuf[261], hostname[256];
1271
1272 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1273 if (otype == DHCPV6_OPT_CLIENTID) {
1274 clid_data = odata;
1275 clid_len = olen;
1276
1277 if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1278 memcpy(mac, &odata[8], sizeof(mac));
1279 else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1280 memcpy(mac, &odata[4], sizeof(mac));
1281
1282 if (olen <= 130)
1283 odhcpd_hexlify(duidbuf, odata, olen);
1284 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1285 uint8_t fqdn_buf[256];
1286 memcpy(fqdn_buf, odata, olen);
1287 fqdn_buf[olen++] = 0;
1288
1289 if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1290 hostname_len = strcspn(hostname, ".");
1291 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1292 accept_reconf = true;
1293 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1294 rapid_commit = true;
1295 }
1296
1297 if (!clid_data || !clid_len || clid_len > 130)
1298 goto out;
1299
1300 l = config_find_lease_by_duid(clid_data, clid_len);
1301 if (!l)
1302 l = config_find_lease_by_mac(mac);
1303
1304 dhcpv6_for_each_option(start, end, otype, olen, odata) {
1305 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1306 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1307 bool ia_addr_present = false;
1308 if (!is_pd && !is_na)
1309 continue;
1310
1311 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1312 size_t ia_response_len = 0;
1313 uint8_t reqlen = (is_pd) ? 62 : 128;
1314 uint32_t reqhint = 0;
1315
1316 /* Parse request hint for IA-PD */
1317 if (is_pd) {
1318 uint8_t *sdata;
1319 uint16_t stype, slen;
1320 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1321 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1322 continue;
1323
1324 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1325 if (p->prefix) {
1326 reqlen = p->prefix;
1327 reqhint = ntohl(p->addr.s6_addr32[1]);
1328 if (reqlen > 32 && reqlen <= 64)
1329 reqhint &= (1U << (64 - reqlen)) - 1;
1330 }
1331 }
1332
1333 if (reqlen > 64)
1334 reqlen = 64;
1335 } else if (is_na) {
1336 uint8_t *sdata;
1337 uint16_t stype, slen;
1338 dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1339 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1340 continue;
1341
1342 ia_addr_present = true;
1343 }
1344 }
1345
1346 /* Find assignment */
1347 struct dhcp_assignment *c, *a = NULL;
1348 list_for_each_entry(c, &iface->ia_assignments, head) {
1349 if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1350 c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1351 ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1352 a = c;
1353
1354 /* Reset state */
1355 if (a->flags & OAF_BOUND)
1356 apply_lease(a, false);
1357
1358 stop_reconf(a);
1359 break;
1360 }
1361 }
1362
1363 if (l && a && a->lease != l) {
1364 free_assignment(a);
1365 a = NULL;
1366 }
1367
1368 /* Generic message handling */
1369 uint16_t status = DHCPV6_STATUS_OK;
1370 if (a && a->managed_size < 0)
1371 return -1;
1372
1373 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1374 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1375 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1376 bool assigned = !!a;
1377
1378 if (!a) {
1379 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1380 (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1381 /* Create new binding */
1382 a = alloc_assignment(clid_len);
1383
1384 if (a) {
1385 a->clid_len = clid_len;
1386 memcpy(a->clid_data, clid_data, clid_len);
1387 a->iaid = ia->iaid;
1388 a->length = reqlen;
1389 a->peer = *addr;
1390 if (is_na)
1391 a->assigned_host_id = l ? l->hostid : 0;
1392 else
1393 a->assigned_subnet_id = reqhint;
1394 a->valid_until = now;
1395 a->preferred_until = now;
1396 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1397 a->iface = iface;
1398 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1399
1400 if (first)
1401 memcpy(a->key, first->key, sizeof(a->key));
1402 else
1403 odhcpd_urandom(a->key, sizeof(a->key));
1404
1405 if (is_pd && iface->dhcpv6_pd)
1406 while (!(assigned = assign_pd(iface, a)) &&
1407 !a->managed_size && ++a->length <= 64);
1408 else if (is_na && iface->dhcpv6_na)
1409 assigned = assign_na(iface, a);
1410
1411 if (l && assigned) {
1412 a->flags |= OAF_STATIC;
1413
1414 if (l->hostname)
1415 a->hostname = strdup(l->hostname);
1416
1417 if (l->leasetime)
1418 a->leasetime = l->leasetime;
1419
1420 list_add(&a->lease_list, &l->assignments);
1421 a->lease = l;
1422 }
1423
1424 if (a->managed_size && !assigned)
1425 return -1;
1426 }
1427 }
1428 }
1429
1430 if (!assigned || iface->addr6_len == 0)
1431 /* Set error status */
1432 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1433 else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1434 /* Send NOTONLINK staus for the IA */
1435 status = DHCPV6_STATUS_NOTONLINK;
1436 assigned = false;
1437 } else if (accept_reconf && assigned && !first &&
1438 hdr->msg_type != DHCPV6_MSG_REBIND) {
1439 size_t handshake_len = 4;
1440 buf[0] = 0;
1441 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1442 buf[2] = 0;
1443 buf[3] = 0;
1444
1445 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1446 struct dhcpv6_auth_reconfigure auth = {
1447 htons(DHCPV6_OPT_AUTH),
1448 htons(sizeof(auth) - 4),
1449 3, 1, 0,
1450 {htonl(time(NULL)), htonl(++serial)},
1451 1,
1452 {0}
1453 };
1454 memcpy(auth.key, a->key, sizeof(a->key));
1455 memcpy(buf + handshake_len, &auth, sizeof(auth));
1456 handshake_len += sizeof(auth);
1457 }
1458
1459
1460 buf += handshake_len;
1461 buflen -= handshake_len;
1462 response_len += handshake_len;
1463
1464 first = a;
1465 }
1466
1467 ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1468 hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1469
1470 /* Was only a solicitation: mark binding for removal */
1471 if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1472 a->flags &= ~OAF_BOUND;
1473 a->flags |= OAF_TENTATIVE;
1474
1475 /* Keep tentative assignment around for 60 seconds */
1476 a->valid_until = now + 60;
1477
1478 } else if (assigned &&
1479 ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1480 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1481 hdr->msg_type == DHCPV6_MSG_REBIND)) {
1482 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1483 a->hostname = realloc(a->hostname, hostname_len + 1);
1484 if (a->hostname) {
1485 memcpy(a->hostname, hostname, hostname_len);
1486 a->hostname[hostname_len] = 0;
1487
1488 if (odhcpd_valid_hostname(a->hostname))
1489 a->flags &= ~OAF_BROKEN_HOSTNAME;
1490 else
1491 a->flags |= OAF_BROKEN_HOSTNAME;
1492 }
1493 }
1494 a->accept_reconf = accept_reconf;
1495 a->flags &= ~OAF_TENTATIVE;
1496 a->flags |= OAF_BOUND;
1497 apply_lease(a, true);
1498 } else if (!assigned && a && a->managed_size == 0) {
1499 /* Cleanup failed assignment */
1500 free_assignment(a);
1501 a = NULL;
1502 }
1503 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1504 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1505 hdr->msg_type == DHCPV6_MSG_REBIND ||
1506 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1507 if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1508 status = DHCPV6_STATUS_NOBINDING;
1509 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1510 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1511 hdr->msg_type == DHCPV6_MSG_REBIND) {
1512 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1513 if (a) {
1514 a->flags |= OAF_BOUND;
1515 apply_lease(a, true);
1516 }
1517 } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1518 a->valid_until = now - 1;
1519 } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1520 a->flags &= ~OAF_BOUND;
1521
1522 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
1523 memset(a->clid_data, 0, a->clid_len);
1524 a->valid_until = now + 3600; /* Block address for 1h */
1525 } else
1526 a->valid_until = now - 1;
1527 }
1528 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1529 if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1530 notonlink = true;
1531 break;
1532 }
1533
1534 if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1535 response_len = 0;
1536 goto out;
1537 }
1538 }
1539
1540 buf += ia_response_len;
1541 buflen -= ia_response_len;
1542 response_len += ia_response_len;
1543 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1544 }
1545
1546 switch (hdr->msg_type) {
1547 case DHCPV6_MSG_RELEASE:
1548 case DHCPV6_MSG_DECLINE:
1549 case DHCPV6_MSG_CONFIRM:
1550 if (response_len + 6 < buflen) {
1551 buf[0] = 0;
1552 buf[1] = DHCPV6_OPT_STATUS;
1553 buf[2] = 0;
1554 buf[3] = 2;
1555 buf[4] = 0;
1556 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1557 response_len += 6;
1558 }
1559 break;
1560
1561 default:
1562 break;
1563 }
1564
1565 dhcpv6_ia_write_statefile();
1566
1567 out:
1568 return response_len;
1569 }
OpenWrt DHCP Server