dhcpv6-ia: cleanup prefix delegation routes
[oweals/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 <stdbool.h>
32 #include <arpa/inet.h>
33 #include <sys/timerfd.h>
34
35 #include <libubox/md5.h>
36 #include <libubox/usock.h>
37
38 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
39     ((iface)->dhcpv6_assignall || (i) == (m) || \
40      (addrs)[(i)].prefix > 64)
41
42 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info);
43 static void apply_lease(struct dhcp_assignment *a, bool add);
44 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
45 static void handle_addrlist_change(struct netevent_handler_info *info);
46 static void start_reconf(struct dhcp_assignment *a);
47 static void stop_reconf(struct dhcp_assignment *a);
48 static void valid_until_cb(struct uloop_timeout *event);
49
50 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
51 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
52 static uint32_t serial = 0;
53 static uint8_t statemd5[16];
54
55 int dhcpv6_ia_init(void)
56 {
57         uloop_timeout_set(&valid_until_timeout, 1000);
58
59         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
60
61         return 0;
62 }
63
64 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
65 {
66         enable = enable && (iface->dhcpv6 == MODE_SERVER);
67
68         if (enable) {
69                 struct dhcp_assignment *border;
70
71                 if (list_empty(&iface->ia_assignments)) {
72                         border = alloc_assignment(0);
73
74                         if (!border) {
75                                 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
76                                 return -1;
77                         }
78
79                         border->length = 64;
80                         list_add(&border->head, &iface->ia_assignments);
81                 } else
82                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
83
84                 set_border_assignment_size(iface, border);
85         } else {
86                 struct dhcp_assignment *c;
87
88                 while (!list_empty(&iface->ia_assignments)) {
89                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
90                         free_assignment(c);
91                 }
92         }
93
94         return 0;
95 }
96
97
98 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
99 {
100         struct interface *iface = info->iface;
101
102         if (!iface || iface->dhcpv6 != MODE_SERVER)
103                 return;
104
105         switch (event) {
106         case NETEV_ADDR6LIST_CHANGE:
107                 handle_addrlist_change(info);
108                 break;
109         default:
110                 break;
111         }
112 }
113
114
115 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
116 {
117         return (a->managed_size || a->length > prefix_length);
118 }
119
120 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
121 {
122         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
123 }
124
125 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
126 {
127         size_t i, m;
128
129         for (i = 0, m = 0; i < addrlen; ++i) {
130                 if (addrs[i].preferred > addrs[m].preferred ||
131                                 (addrs[i].preferred == addrs[m].preferred &&
132                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
133                         m = i;
134         }
135
136         return m;
137 }
138
139 static int send_reconf(struct dhcp_assignment *assign)
140 {
141         struct {
142                 struct dhcpv6_client_header hdr;
143                 uint16_t srvid_type;
144                 uint16_t srvid_len;
145                 uint16_t duid_type;
146                 uint16_t hardware_type;
147                 uint8_t mac[6];
148                 uint16_t msg_type;
149                 uint16_t msg_len;
150                 uint8_t msg_id;
151                 struct dhcpv6_auth_reconfigure auth;
152                 uint16_t clid_type;
153                 uint16_t clid_len;
154                 uint8_t clid_data[128];
155         } __attribute__((packed)) reconf_msg = {
156                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
157                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
158                 .srvid_len = htons(10),
159                 .duid_type = htons(3),
160                 .hardware_type = htons(1),
161                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
162                 .msg_len = htons(1),
163                 .msg_id = DHCPV6_MSG_RENEW,
164                 .auth = {htons(DHCPV6_OPT_AUTH),
165                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
166                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
167                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
168                 .clid_len = htons(assign->clid_len),
169                 .clid_data = {0},
170         };
171         struct interface *iface = assign->iface;
172
173         odhcpd_get_mac(iface, reconf_msg.mac);
174         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
175         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
176
177         md5_ctx_t md5;
178         uint8_t secretbytes[64];
179         memset(secretbytes, 0, sizeof(secretbytes));
180         memcpy(secretbytes, assign->key, sizeof(assign->key));
181
182         for (size_t i = 0; i < sizeof(secretbytes); ++i)
183                 secretbytes[i] ^= 0x36;
184
185         md5_begin(&md5);
186         md5_hash(secretbytes, sizeof(secretbytes), &md5);
187         md5_hash(iov.iov_base, iov.iov_len, &md5);
188         md5_end(reconf_msg.auth.key, &md5);
189
190         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
191                 secretbytes[i] ^= 0x36;
192                 secretbytes[i] ^= 0x5c;
193         }
194
195         md5_begin(&md5);
196         md5_hash(secretbytes, sizeof(secretbytes), &md5);
197         md5_hash(reconf_msg.auth.key, 16, &md5);
198         md5_end(reconf_msg.auth.key, &md5);
199
200         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
201 }
202
203 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
204 {
205         if (a->managed_sock.fd.registered) {
206                 ustream_free(&a->managed_sock.stream);
207                 close(a->managed_sock.fd.fd);
208         }
209
210         if (a->flags & OAF_BOUND && a->length < 128)
211                 apply_lease(a, false);
212
213         if (a->reconf_cnt)
214                 stop_reconf(a);
215
216         free(a->managed);
217 }
218
219 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
220                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
221 {
222         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
223         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
224         size_t m = get_preferred_addr(addrs, addrlen);
225
226         for (size_t i = 0; i < addrlen; ++i) {
227                 struct in6_addr addr;
228                 uint32_t pref, valid;
229                 int prefix = c->managed ? addrs[i].prefix : c->length;
230
231                 if (!valid_addr(&addrs[i], now))
232                         continue;
233
234                 addr = addrs[i].addr.in6;
235                 pref = addrs[i].preferred;
236                 valid = addrs[i].valid;
237                 if (prefix == 128) {
238                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
239                                 continue;
240
241                         addr.s6_addr32[3] = htonl(c->assigned);
242                 } else {
243                         if (!valid_prefix_length(c, addrs[i].prefix))
244                                 continue;
245
246                         addr.s6_addr32[1] |= htonl(c->assigned);
247                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
248                 }
249
250                 if (pref != UINT32_MAX)
251                         pref -= now;
252
253                 if (valid != UINT32_MAX)
254                         valid -= now;
255
256                 func(&addr, prefix, pref, valid, arg);
257         }
258 }
259
260 struct write_ctxt {
261         FILE *fp;
262         md5_ctx_t md5;
263         struct dhcp_assignment *c;
264         struct interface *iface;
265         char *buf;
266         int buf_len;
267         int buf_idx;
268 };
269
270 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
271                                 _unused uint32_t valid, void *arg)
272 {
273         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
274         char ipbuf[INET6_ADDRSTRLEN];
275
276         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
277
278         if (ctxt->c->length == 128 && ctxt->c->hostname &&
279             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
280                 fputs(ipbuf, ctxt->fp);
281
282                 char b[256];
283                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
284                                 ctxt->iface->search, b, sizeof(b)) > 0)
285                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
286
287                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
288                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
289                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
290         }
291
292         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
293                                         "%s/%d ", ipbuf, prefix);
294 }
295
296 void dhcpv6_ia_write_statefile(void)
297 {
298         struct write_ctxt ctxt;
299
300         md5_begin(&ctxt.md5);
301
302         if (config.dhcp_statefile) {
303                 time_t now = odhcpd_time(), wall_time = time(NULL);
304                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
305                 char leasebuf[512];
306
307                 if (fd < 0)
308                         return;
309                 int ret;
310                 ret = lockf(fd, F_LOCK, 0);
311                 if (ret < 0) {
312                         close(fd);
313                         return;
314                 }
315                 if (ftruncate(fd, 0) < 0) {}
316
317                 ctxt.fp = fdopen(fd, "w");
318                 if (!ctxt.fp) {
319                         close(fd);
320                         return;
321                 }
322
323                 ctxt.buf = leasebuf;
324                 ctxt.buf_len = sizeof(leasebuf);
325
326                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
327                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
328                                         ctxt.iface->dhcpv4 != MODE_SERVER)
329                                 continue;
330
331                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
332                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
333                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
334                                                 continue;
335
336                                         char duidbuf[264];
337
338                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
339
340                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
341                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %ld %x %u ",
342                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
343                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
344                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
345                                                                 (ctxt.c->valid_until > now ?
346                                                                         (ctxt.c->valid_until - now + wall_time) :
347                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
348                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
349
350                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
351                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
352                                                                         dhcpv6_write_ia_addr, &ctxt);
353
354                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
355                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
356                                 }
357                         }
358
359                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
360                                 struct dhcp_assignment *c;
361
362                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
363                                         if (!(c->flags & OAF_BOUND))
364                                                 continue;
365
366                                         char ipbuf[INET6_ADDRSTRLEN];
367                                         char duidbuf[16];
368                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
369
370                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
371                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %ld %x 32 ",
372                                                                 ctxt.iface->ifname, duidbuf,
373                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
374                                                                 (c->hostname ? c->hostname : "-"),
375                                                                 (c->valid_until > now ?
376                                                                         (c->valid_until - now + wall_time) :
377                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
378                                                                 ntohl(c->addr));
379
380                                         struct in_addr addr = {.s_addr = c->addr};
381                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
382
383                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
384                                                 fputs(ipbuf, ctxt.fp);
385
386                                                 char b[256];
387                                                 if (dn_expand(ctxt.iface->search,
388                                                                 ctxt.iface->search + ctxt.iface->search_len,
389                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
390                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
391
392                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
393                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
394                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
395                                         }
396
397                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
398                                                                         ctxt.buf_len - ctxt.buf_idx,
399                                                                         "%s/32 ", ipbuf);
400                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
401                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
402                                 }
403                         }
404                 }
405
406                 fclose(ctxt.fp);
407         }
408
409         uint8_t newmd5[16];
410         md5_end(newmd5, &ctxt.md5);
411
412         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
413                 memcpy(statemd5, newmd5, sizeof(statemd5));
414                 char *argv[2] = {config.dhcp_cb, NULL};
415                 if (!vfork()) {
416                         execv(argv[0], argv);
417                         _exit(128);
418                 }
419         }
420 }
421
422 static void __apply_lease(struct dhcp_assignment *a,
423                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
424 {
425         if (a->length > 64)
426                 return;
427
428         for (ssize_t i = 0; i < addr_len; ++i) {
429                 struct in6_addr prefix = addrs[i].addr.in6;
430                 prefix.s6_addr32[1] |= htonl(a->assigned);
431                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
432                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
433                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
434         }
435 }
436
437 static void apply_lease(struct dhcp_assignment *a, bool add)
438 {
439         struct interface *iface = a->iface;
440         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
441         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
442
443         __apply_lease(a, addrs, addrlen, add);
444 }
445
446 /* Set border assignment size based on the IPv6 address prefixes */
447 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
448 {
449         time_t now = odhcpd_time();
450         int minprefix = -1;
451
452         for (size_t i = 0; i < iface->addr6_len; ++i) {
453                 if (iface->addr6[i].preferred > (uint32_t)now &&
454                                 iface->addr6[i].prefix < 64 &&
455                                 iface->addr6[i].prefix > minprefix)
456                         minprefix = iface->addr6[i].prefix;
457         }
458
459         if (minprefix > 32 && minprefix <= 64)
460                 b->assigned = 1U << (64 - minprefix);
461         else
462                 b->assigned = 0;
463 }
464
465 /* More data was received from TCP connection */
466 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
467 {
468         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
469         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
470         time_t now = odhcpd_time();
471         bool first = c->managed_size < 0;
472
473         for (;;) {
474                 int pending;
475                 char *data = ustream_get_read_buf(s, &pending);
476                 char *end = memmem(data, pending, "\n\n", 2);
477
478                 if (!end)
479                         break;
480
481                 end += 2;
482                 end[-1] = 0;
483
484                 c->managed_size = 0;
485                 if (c->accept_reconf)
486                         c->reconf_cnt = 1;
487
488                 char *saveptr;
489                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
490                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
491                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
492
493                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
494                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
495                                 continue;
496
497                         x = strtok_r(NULL, ",", &saveptr2);
498                         if (sscanf(x, "%hhu", &n->prefix) < 1)
499                                 continue;
500
501                         x = strtok_r(NULL, ",", &saveptr2);
502                         if (sscanf(x, "%u", &n->preferred) < 1)
503                                 continue;
504
505                         x = strtok_r(NULL, ",", &saveptr2);
506                         if (sscanf(x, "%u", &n->valid) < 1)
507                                 continue;
508
509                         if (n->preferred > n->valid)
510                                 continue;
511
512                         if (UINT32_MAX - now < n->preferred)
513                                 n->preferred = UINT32_MAX;
514                         else
515                                 n->preferred += now;
516
517                         if (UINT32_MAX - now < n->valid)
518                                 n->valid = UINT32_MAX;
519                         else
520                                 n->valid += now;
521
522                         n->dprefix = 0;
523
524                         ++c->managed_size;
525                 }
526
527                 ustream_consume(s, end - data);
528         }
529
530         if (first && c->managed_size == 0)
531                 free_assignment(c);
532         else if (first && !(c->flags & OAF_STATIC))
533                 c->valid_until = now + 150;
534 }
535
536
537 /* TCP transmission has ended, either because of success or timeout or other error */
538 static void managed_handle_pd_done(struct ustream *s)
539 {
540         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
541         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
542
543         if (!(c->flags & OAF_STATIC))
544                 c->valid_until = odhcpd_time() + 15;
545
546         c->managed_size = 0;
547
548         if (c->accept_reconf)
549                 c->reconf_cnt = 1;
550 }
551
552 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
553 {
554         struct dhcp_assignment *c;
555
556         if (iface->dhcpv6_pd_manager[0]) {
557                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
558                 if (fd >= 0) {
559                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
560                         char iaidbuf[298];
561
562                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
563
564                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
565                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
566                         ustream_fd_init(&assign->managed_sock, fd);
567                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
568                                         iaidbuf, assign->iaid, assign->length);
569                         ustream_write_pending(&assign->managed_sock.stream);
570                         assign->managed_size = -1;
571
572                         if (!(assign->flags & OAF_STATIC))
573                                 assign->valid_until = odhcpd_time() + 15;
574
575                         list_add(&assign->head, &iface->ia_assignments);
576
577                         /* Wait initial period of up to 250ms for immediate assignment */
578                         if (poll(&pfd, 1, 250) < 0) {
579                                 syslog(LOG_ERR, "poll(): %m");
580                                 return false;
581                         }
582
583                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
584
585                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
586                                 return true;
587                 }
588
589                 return false;
590         } else if (iface->addr6_len < 1)
591                 return false;
592
593         /* Try honoring the hint first */
594         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
595         if (assign->assigned) {
596                 list_for_each_entry(c, &iface->ia_assignments, head) {
597                         if (c->length == 128 || c->length == 0)
598                                 continue;
599
600                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
601                                 list_add_tail(&assign->head, &c->head);
602
603                                 if (assign->flags & OAF_BOUND)
604                                         apply_lease(assign, true);
605
606                                 return true;
607                         }
608
609                         if (c->assigned != 0)
610                                 current = (c->assigned + (1 << (64 - c->length)));
611                 }
612         }
613
614         /* Fallback to a variable assignment */
615         current = 1;
616         list_for_each_entry(c, &iface->ia_assignments, head) {
617                 if (c->length == 128 || c->length == 0)
618                         continue;
619
620                 current = (current + asize) & (~asize);
621                 if (current + asize < c->assigned) {
622                         assign->assigned = current;
623                         list_add_tail(&assign->head, &c->head);
624
625                         if (assign->flags & OAF_BOUND)
626                                 apply_lease(assign, true);
627
628                         return true;
629                 }
630
631                 if (c->assigned != 0)
632                         current = (c->assigned + (1 << (64 - c->length)));
633         }
634
635         return false;
636 }
637
638 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
639 {
640         struct dhcp_assignment *c;
641         uint32_t seed = 0;
642
643         /* Preconfigured assignment by static lease */
644         if (a->assigned) {
645                 list_for_each_entry(c, &iface->ia_assignments, head) {
646                         if (c->length == 0)
647                                 continue;
648
649                         if (c->assigned > a->assigned || c->length != 128) {
650                                 list_add_tail(&a->head, &c->head);
651                                 return true;
652                         } else if (c->assigned == a->assigned)
653                                 return false;
654                 }
655         }
656
657         /* Seed RNG with checksum of DUID */
658         for (size_t i = 0; i < a->clid_len; ++i)
659                 seed += a->clid_data[i];
660         srand(seed);
661
662         /* Try to assign up to 100x */
663         for (size_t i = 0; i < 100; ++i) {
664                 uint32_t try;
665                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
666
667                 if (config_find_lease_by_hostid(try))
668                         continue;
669
670                 list_for_each_entry(c, &iface->ia_assignments, head) {
671                         if (c->length == 0)
672                                 continue;
673
674                         if (c->assigned > try || c->length != 128) {
675                                 a->assigned = try;
676                                 list_add_tail(&a->head, &c->head);
677                                 return true;
678                         } else if (c->assigned == try)
679                                 break;
680                 }
681         }
682
683         return false;
684 }
685
686 static void handle_addrlist_change(struct netevent_handler_info *info)
687 {
688         struct interface *iface = info->iface;
689         struct dhcp_assignment *c, *d, *border = list_last_entry(
690                         &iface->ia_assignments, struct dhcp_assignment, head);
691         struct list_head reassign = LIST_HEAD_INIT(reassign);
692         time_t now = odhcpd_time();
693
694         list_for_each_entry(c, &iface->ia_assignments, head) {
695                 if (c != border && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
696                                 && (c->flags & OAF_BOUND))
697                         __apply_lease(c, info->addrs_old.addrs,
698                                         info->addrs_old.len, false);
699         }
700
701         set_border_assignment_size(iface, border);
702
703         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
704                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
705                                 c->managed_size)
706                         continue;
707
708                 if (c->length < 128 && (c->assigned == 0 || c->assigned >= border->assigned) && c != border)
709                         list_move(&c->head, &reassign);
710                 else if (c != border && (c->flags & OAF_BOUND))
711                         apply_lease(c, true);
712
713                 if (c->accept_reconf && c->reconf_cnt == 0) {
714                         struct dhcp_assignment *a;
715
716                         start_reconf(c);
717
718                         /* Leave all other assignments of that client alone */
719                         list_for_each_entry(a, &iface->ia_assignments, head)
720                                 if (a != c && a->clid_len == c->clid_len &&
721                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
722                                         a->reconf_cnt = INT_MAX;
723                 }
724         }
725
726         while (!list_empty(&reassign)) {
727                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
728                 list_del_init(&c->head);
729                 if (!assign_pd(iface, c)) {
730                         c->assigned = 0;
731                         list_add(&c->head, &iface->ia_assignments);
732                 }
733         }
734
735         dhcpv6_ia_write_statefile();
736 }
737
738 static void reconf_timeout_cb(struct uloop_timeout *event)
739 {
740         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
741
742         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
743                 send_reconf(a);
744                 uloop_timeout_set(&a->reconf_timer,
745                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
746                 a->reconf_cnt++;
747         } else
748                 stop_reconf(a);
749 }
750
751 static void start_reconf(struct dhcp_assignment *a)
752 {
753         uloop_timeout_set(&a->reconf_timer,
754                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
755         a->reconf_timer.cb = reconf_timeout_cb;
756         a->reconf_cnt++;
757
758         send_reconf(a);
759 }
760
761 static void stop_reconf(struct dhcp_assignment *a)
762 {
763         uloop_timeout_cancel(&a->reconf_timer);
764         a->reconf_cnt = 0;
765         a->reconf_timer.cb = NULL;
766 }
767
768 static void valid_until_cb(struct uloop_timeout *event)
769 {
770         struct interface *iface;
771         time_t now = odhcpd_time();
772
773         avl_for_each_element(&interfaces, iface, avl) {
774                 struct dhcp_assignment *a, *n;
775
776                 if (iface->dhcpv6 != MODE_SERVER)
777                         continue;
778
779                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
780                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
781                                 free_assignment(a);
782                 }
783         }
784         uloop_timeout_set(event, 1000);
785 }
786
787 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
788                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
789                 struct interface *iface, bool request)
790 {
791         struct dhcpv6_ia_hdr o_ia = {
792                 .type = ia->type,
793                 .len = 0,
794                 .iaid = ia->iaid,
795                 .t1 = 0,
796                 .t2 = 0,
797         };
798         size_t ia_len = sizeof(o_ia);
799         time_t now = odhcpd_time();
800
801         if (buflen < ia_len)
802                 return 0;
803
804         if (status) {
805                 struct __attribute__((packed)) {
806                         uint16_t type;
807                         uint16_t len;
808                         uint16_t val;
809                 } o_status = {
810                         .type = htons(DHCPV6_OPT_STATUS),
811                         .len = htons(sizeof(o_status) - 4),
812                         .val = htons(status),
813                 };
814
815                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
816                 ia_len += sizeof(o_status);
817
818                 o_ia.len = htons(ia_len - 4);
819                 memcpy(buf, &o_ia, sizeof(o_ia));
820
821                 return ia_len;
822         }
823
824         if (a) {
825                 uint32_t leasetime;
826
827                 if (a->leasetime)
828                         leasetime = a->leasetime;
829                 else
830                         leasetime = iface->dhcpv4_leasetime;
831
832                 uint32_t pref = leasetime;
833                 uint32_t valid = leasetime;
834
835                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
836                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
837                 size_t m = get_preferred_addr(addrs, addrlen);
838
839                 for (size_t i = 0; i < addrlen; ++i) {
840                         uint32_t prefix_pref = addrs[i].preferred;
841                         uint32_t prefix_valid = addrs[i].valid;
842
843                         if (!valid_addr(&addrs[i], now))
844                                 continue;
845
846                         if (prefix_pref != UINT32_MAX)
847                                 prefix_pref -= now;
848
849                         if (prefix_valid != UINT32_MAX)
850                                 prefix_valid -= now;
851
852                         if (a->length < 128) {
853                                 struct dhcpv6_ia_prefix o_ia_p = {
854                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
855                                         .len = htons(sizeof(o_ia_p) - 4),
856                                         .preferred = htonl(prefix_pref),
857                                         .valid = htonl(prefix_valid),
858                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
859                                         .addr = addrs[i].addr.in6,
860                                 };
861
862                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned);
863                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
864
865                                 if ((a->assigned == 0 && a->managed_size == 0) ||
866                                                 !valid_prefix_length(a, addrs[i].prefix))
867                                         continue;
868
869                                 if (buflen < ia_len + sizeof(o_ia_p))
870                                         return 0;
871
872                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
873                                 ia_len += sizeof(o_ia_p);
874                         } else {
875                                 struct dhcpv6_ia_addr o_ia_a = {
876                                         .type = htons(DHCPV6_OPT_IA_ADDR),
877                                         .len = htons(sizeof(o_ia_a) - 4),
878                                         .addr = addrs[i].addr.in6,
879                                         .preferred = htonl(prefix_pref),
880                                         .valid = htonl(prefix_valid)
881                                 };
882
883                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned);
884
885                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
886                                                 a->assigned == 0)
887                                         continue;
888
889                                 if (buflen < ia_len + sizeof(o_ia_a))
890                                         return 0;
891
892                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
893                                 ia_len += sizeof(o_ia_a);
894                         }
895
896                         /* Calculate T1 / T2 based on non-deprecated addresses */
897                         if (prefix_pref > 0) {
898                                 if (prefix_pref < pref)
899                                         pref = prefix_pref;
900
901                                 if (prefix_valid < valid)
902                                         valid = prefix_valid;
903                         }
904                 }
905
906                 if (!INFINITE_VALID(a->valid_until))
907                         /* UINT32_MAX is considered as infinite leasetime */
908                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
909
910                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
911                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
912
913                 if (!o_ia.t1)
914                         o_ia.t1 = htonl(1);
915
916                 if (!o_ia.t2)
917                         o_ia.t2 = htonl(1);
918         }
919
920         if (!request) {
921                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
922                 uint16_t otype, olen;
923
924                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
925                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
926                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
927                         bool found = false;
928
929                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
930                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
931                                 continue;
932
933                         if (a) {
934                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
935                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
936
937                                 for (size_t i = 0; i < addrlen; ++i) {
938                                         if (!valid_addr(&addrs[i], now))
939                                                 continue;
940
941                                         struct in6_addr addr = addrs[i].addr.in6;
942                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
943                                                 addr.s6_addr32[1] |= htonl(a->assigned);
944                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
945
946                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
947                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
948                                                         found = true;
949                                         } else {
950                                                 addr.s6_addr32[3] = htonl(a->assigned);
951
952                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
953                                                         found = true;
954                                         }
955                                 }
956                         }
957
958                         if (!found) {
959                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
960                                         struct dhcpv6_ia_prefix o_ia_p = {
961                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
962                                                 .len = htons(sizeof(o_ia_p) - 4),
963                                                 .preferred = 0,
964                                                 .valid = 0,
965                                                 .prefix = ia_p->prefix,
966                                                 .addr = ia_p->addr,
967                                         };
968
969                                         if (buflen < ia_len + sizeof(o_ia_p))
970                                                 return 0;
971
972                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
973                                         ia_len += sizeof(o_ia_p);
974                                 } else {
975                                         struct dhcpv6_ia_addr o_ia_a = {
976                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
977                                                 .len = htons(sizeof(o_ia_a) - 4),
978                                                 .addr = ia_a->addr,
979                                                 .preferred = 0,
980                                                 .valid = 0,
981                                         };
982
983                                         if (buflen < ia_len + sizeof(o_ia_a))
984                                                 continue;
985
986                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
987                                         ia_len += sizeof(o_ia_a);
988                                 }
989                         }
990                 }
991         }
992
993         o_ia.len = htons(ia_len - 4);
994         memcpy(buf, &o_ia, sizeof(o_ia));
995         return ia_len;
996 }
997
998 struct log_ctxt {
999         char *buf;
1000         int buf_len;
1001         int buf_idx;
1002 };
1003
1004 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1005                                 _unused uint32_t valid, void *arg)
1006 {
1007         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1008         char addrbuf[INET6_ADDRSTRLEN];
1009
1010         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1011         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1012                                         "%s/%d ", addrbuf, prefix);
1013 }
1014
1015 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1016                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1017 {
1018         const char *type = "UNKNOWN";
1019         const char *status = "UNKNOWN";
1020
1021         switch (msgtype) {
1022         case DHCPV6_MSG_SOLICIT:
1023                 type = "SOLICIT";
1024                 break;
1025         case DHCPV6_MSG_REQUEST:
1026                 type = "REQUEST";
1027                 break;
1028         case DHCPV6_MSG_CONFIRM:
1029                 type = "CONFIRM";
1030                 break;
1031         case DHCPV6_MSG_RENEW:
1032                 type = "RENEW";
1033                 break;
1034         case DHCPV6_MSG_REBIND:
1035                 type = "REBIND";
1036                 break;
1037         case DHCPV6_MSG_RELEASE:
1038                 type = "RELEASE";
1039                 break;
1040         case DHCPV6_MSG_DECLINE:
1041                 type = "DECLINE";
1042                 break;
1043         }
1044
1045         switch (code) {
1046         case DHCPV6_STATUS_OK:
1047                 status = "ok";
1048                 break;
1049         case DHCPV6_STATUS_NOADDRSAVAIL:
1050                 status = "no addresses available";
1051                 break;
1052         case DHCPV6_STATUS_NOBINDING:
1053                 status = "no binding";
1054                 break;
1055         case DHCPV6_STATUS_NOTONLINK:
1056                 status = "not on-link";
1057                 break;
1058         case DHCPV6_STATUS_NOPREFIXAVAIL:
1059                 status = "no prefix available";
1060                 break;
1061         }
1062
1063         char leasebuf[256] = "";
1064
1065         if (a) {
1066                 struct log_ctxt ctxt = {.buf = leasebuf,
1067                                         .buf_len = sizeof(leasebuf),
1068                                         .buf_idx = 0 };
1069
1070                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1071         }
1072
1073         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1074                          duidbuf, iface->name, status, leasebuf);
1075 }
1076
1077 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1078                 struct interface *iface)
1079 {
1080         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1081         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1082         time_t now = odhcpd_time();
1083         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1084         uint16_t otype, olen;
1085         bool onlink = true;
1086
1087         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1088                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1089                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1090
1091                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1092                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1093                         continue;
1094
1095                 onlink = false;
1096                 for (size_t i = 0; i < addrlen; ++i) {
1097                         if (!valid_addr(&addrs[i], now))
1098                                 continue;
1099
1100                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1101                                 if (p->prefix < addrs[i].prefix ||
1102                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1103                                         continue;
1104
1105                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1106                                 continue;
1107
1108                         onlink = true;
1109                 }
1110
1111                 if (!onlink)
1112                         break;
1113         }
1114
1115         return onlink;
1116 }
1117
1118 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1119                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1120 {
1121         struct lease *l;
1122         struct dhcp_assignment *first = NULL;
1123         const struct dhcpv6_client_header *hdr = data;
1124         time_t now = odhcpd_time();
1125         uint16_t otype, olen, clid_len = 0;
1126         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1127         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1128         size_t hostname_len = 0, response_len = 0;
1129         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1130         char duidbuf[261], hostname[256];
1131
1132         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1133                 if (otype == DHCPV6_OPT_CLIENTID) {
1134                         clid_data = odata;
1135                         clid_len = olen;
1136
1137                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1138                                 memcpy(mac, &odata[8], sizeof(mac));
1139                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1140                                 memcpy(mac, &odata[4], sizeof(mac));
1141
1142                         if (olen <= 130)
1143                                 odhcpd_hexlify(duidbuf, odata, olen);
1144                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1145                         uint8_t fqdn_buf[256];
1146                         memcpy(fqdn_buf, odata, olen);
1147                         fqdn_buf[olen++] = 0;
1148
1149                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1150                                 hostname_len = strcspn(hostname, ".");
1151                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1152                         accept_reconf = true;
1153                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1154                         rapid_commit = true;
1155         }
1156
1157         if (!clid_data || !clid_len || clid_len > 130)
1158                 goto out;
1159
1160         l = config_find_lease_by_duid(clid_data, clid_len);
1161         if (!l)
1162                 l = config_find_lease_by_mac(mac);
1163
1164         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1165                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1166                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1167                 bool ia_addr_present = false;
1168                 if (!is_pd && !is_na)
1169                         continue;
1170
1171                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1172                 size_t ia_response_len = 0;
1173                 uint8_t reqlen = (is_pd) ? 62 : 128;
1174                 uint32_t reqhint = 0;
1175
1176                 /* Parse request hint for IA-PD */
1177                 if (is_pd) {
1178                         uint8_t *sdata;
1179                         uint16_t stype, slen;
1180                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1181                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1182                                         continue;
1183
1184                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1185                                 if (p->prefix) {
1186                                         reqlen = p->prefix;
1187                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1188                                         if (reqlen > 32 && reqlen <= 64)
1189                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1190                                 }
1191                         }
1192
1193                         if (reqlen > 64)
1194                                 reqlen = 64;
1195                 } else if (is_na) {
1196                         uint8_t *sdata;
1197                         uint16_t stype, slen;
1198                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1199                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1200                                         continue;
1201
1202                                 ia_addr_present = true;
1203                         }
1204                 }
1205
1206                 /* Find assignment */
1207                 struct dhcp_assignment *c, *a = NULL;
1208                 list_for_each_entry(c, &iface->ia_assignments, head) {
1209                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1210                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1211                             ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1212                                 a = c;
1213
1214                                 /* Reset state */
1215                                 if (a->flags & OAF_BOUND)
1216                                         apply_lease(a, false);
1217
1218                                 stop_reconf(a);
1219                                 break;
1220                         }
1221                 }
1222
1223                 if (l && a && a->lease != l) {
1224                         free_assignment(a);
1225                         a = NULL;
1226                 }
1227
1228                 /* Generic message handling */
1229                 uint16_t status = DHCPV6_STATUS_OK;
1230                 if (a && a->managed_size < 0)
1231                         return -1;
1232
1233                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1234                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1235                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1236                         bool assigned = !!a;
1237
1238                         if (!a) {
1239                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1240                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1241                                         /* Create new binding */
1242                                         a = alloc_assignment(clid_len);
1243
1244                                         if (a) {
1245                                                 a->clid_len = clid_len;
1246                                                 memcpy(a->clid_data, clid_data, clid_len);
1247                                                 a->iaid = ia->iaid;
1248                                                 a->length = reqlen;
1249                                                 a->peer = *addr;
1250                                                 a->assigned = is_na && l ? l->hostid : reqhint;
1251                                                 /* Set valid time to 0 for static lease indicating */
1252                                                 /* infinite lifetime otherwise current time        */
1253                                                 a->valid_until = l ? 0 : now;
1254                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1255                                                 a->iface = iface;
1256                                                 a->flags = OAF_DHCPV6;
1257
1258                                                 if (first)
1259                                                         memcpy(a->key, first->key, sizeof(a->key));
1260                                                 else
1261                                                         odhcpd_urandom(a->key, sizeof(a->key));
1262
1263                                                 if (is_pd && iface->dhcpv6_pd)
1264                                                         while (!(assigned = assign_pd(iface, a)) &&
1265                                                                !a->managed_size && ++a->length <= 64);
1266                                                 else if (is_na && iface->dhcpv6_na)
1267                                                         assigned = assign_na(iface, a);
1268
1269                                                 if (l && assigned) {
1270                                                         a->flags |= OAF_STATIC;
1271
1272                                                         if (l->hostname)
1273                                                                 a->hostname = strdup(l->hostname);
1274
1275                                                         if (l->leasetime)
1276                                                                 a->leasetime = l->leasetime;
1277
1278                                                         list_add(&a->lease_list, &l->assignments);
1279                                                         a->lease = l;
1280                                                 }
1281
1282                                                 if (a->managed_size && !assigned)
1283                                                         return -1;
1284                                         }
1285                                 }
1286                         }
1287
1288                         if (!assigned || iface->addr6_len == 0)
1289                                 /* Set error status */
1290                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1291                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1292                                 /* Send NOTONLINK staus for the IA */
1293                                 status = DHCPV6_STATUS_NOTONLINK;
1294                                 assigned = false;
1295                         } else if (accept_reconf && assigned && !first &&
1296                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1297                                 size_t handshake_len = 4;
1298                                 buf[0] = 0;
1299                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1300                                 buf[2] = 0;
1301                                 buf[3] = 0;
1302
1303                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1304                                         struct dhcpv6_auth_reconfigure auth = {
1305                                                 htons(DHCPV6_OPT_AUTH),
1306                                                 htons(sizeof(auth) - 4),
1307                                                 3, 1, 0,
1308                                                 {htonl(time(NULL)), htonl(++serial)},
1309                                                 1,
1310                                                 {0}
1311                                         };
1312                                         memcpy(auth.key, a->key, sizeof(a->key));
1313                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1314                                         handshake_len += sizeof(auth);
1315                                 }
1316
1317
1318                                 buf += handshake_len;
1319                                 buflen -= handshake_len;
1320                                 response_len += handshake_len;
1321
1322                                 first = a;
1323                         }
1324
1325                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1326                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1327
1328                         /* Was only a solicitation: mark binding for removal */
1329                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1330                                 a->flags &= ~OAF_BOUND;
1331                                 a->flags |= OAF_TENTATIVE;
1332
1333                                 if (!(a->flags & OAF_STATIC))
1334                                         /* Keep tentative assignment around for 60 seconds */
1335                                         a->valid_until = now + 60;
1336
1337                         } else if (assigned &&
1338                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1339                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1340                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1341                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1342                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1343                                         if (a->hostname) {
1344                                                 memcpy(a->hostname, hostname, hostname_len);
1345                                                 a->hostname[hostname_len] = 0;
1346
1347                                                 if (odhcpd_valid_hostname(a->hostname))
1348                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1349                                                 else
1350                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1351                                         }
1352                                 }
1353                                 a->accept_reconf = accept_reconf;
1354                                 a->flags &= ~OAF_TENTATIVE;
1355                                 a->flags |= OAF_BOUND;
1356                                 apply_lease(a, true);
1357                         } else if (!assigned && a && a->managed_size == 0) {
1358                                 /* Cleanup failed assignment */
1359                                 free_assignment(a);
1360                                 a = NULL;
1361                         }
1362                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1363                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1364                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1365                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1366                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1367                                 status = DHCPV6_STATUS_NOBINDING;
1368                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1369                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1370                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1371                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1372                                 if (a) {
1373                                         a->flags |= OAF_BOUND;
1374                                         apply_lease(a, true);
1375                                 }
1376                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1377                                 if (a->flags & OAF_STATIC) {
1378                                         apply_lease(a, false);
1379                                         a->flags &= ~OAF_BOUND;
1380                                 }
1381                                 else
1382                                         a->valid_until = now - 1;
1383
1384                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1385                                 a->flags &= ~OAF_BOUND;
1386
1387                                 if (!(a->flags & OAF_STATIC)) {
1388                                         memset(a->clid_data, 0, a->clid_len);
1389                                         a->valid_until = now + 3600; /* Block address for 1h */
1390                                 }
1391                         }
1392                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1393                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1394                                 notonlink = true;
1395                                 break;
1396                         }
1397
1398                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1399                                 response_len = 0;
1400                                 goto out;
1401                         }
1402                 }
1403
1404                 buf += ia_response_len;
1405                 buflen -= ia_response_len;
1406                 response_len += ia_response_len;
1407                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1408         }
1409
1410         switch (hdr->msg_type) {
1411         case DHCPV6_MSG_RELEASE:
1412         case DHCPV6_MSG_DECLINE:
1413         case DHCPV6_MSG_CONFIRM:
1414                 if (response_len + 6 < buflen) {
1415                         buf[0] = 0;
1416                         buf[1] = DHCPV6_OPT_STATUS;
1417                         buf[2] = 0;
1418                         buf[3] = 2;
1419                         buf[4] = 0;
1420                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1421                         response_len += 6;
1422                 }
1423                 break;
1424
1425         default:
1426                 break;
1427         }
1428
1429         dhcpv6_ia_write_statefile();
1430
1431 out:
1432         return response_len;
1433 }