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Sources/odhcpd/src/dhcpv6-ia.c

  1 /**
  2  * Copyright (C) 2013 Steven Barth <steven@midlink.org>
  3  * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
  4  *
  5  * This program is free software; you can redistribute it and/or modify
  6  * it under the terms of the GNU General Public License v2 as published by
  7  * the Free Software Foundation.
  8  *
  9  * This program is distributed in the hope that it will be useful,
 10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12  * GNU General Public License for more details.
 13  *
 14  */
 15 
 16 #include "odhcpd.h"
 17 #include "dhcpv6.h"
 18 #include "dhcpv4.h"
 19 
 20 #include <time.h>
 21 #include <errno.h>
 22 #include <fcntl.h>
 23 #include <stdio.h>
 24 #include <poll.h>
 25 #include <alloca.h>
 26 #include <resolv.h>
 27 #include <limits.h>
 28 #include <stdlib.h>
 29 #include <string.h>
 30 #include <unistd.h>
 31 #include <libgen.h>
 32 #include <stdbool.h>
 33 #include <arpa/inet.h>
 34 #include <sys/timerfd.h>
 35 
 36 #include <libubox/md5.h>
 37 #include <libubox/usock.h>
 38 
 39 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
 40     ((iface)->dhcpv6_assignall || (i) == (m) || \
 41      (addrs)[(i)].prefix > 64)
 42 
 43 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info);
 44 static void apply_lease(struct dhcp_assignment *a, bool add);
 45 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
 46 static void handle_addrlist_change(struct netevent_handler_info *info);
 47 static void start_reconf(struct dhcp_assignment *a);
 48 static void stop_reconf(struct dhcp_assignment *a);
 49 static void valid_until_cb(struct uloop_timeout *event);
 50 
 51 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
 52 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
 53 static uint32_t serial = 0;
 54 static uint8_t statemd5[16];
 55 
 56 int dhcpv6_ia_init(void)
 57 {
 58         uloop_timeout_set(&valid_until_timeout, 1000);
 59 
 60         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
 61 
 62         return 0;
 63 }
 64 
 65 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
 66 {
 67         enable = enable && (iface->dhcpv6 == MODE_SERVER);
 68 
 69         if (enable) {
 70                 struct dhcp_assignment *border;
 71 
 72                 if (list_empty(&iface->ia_assignments)) {
 73                         border = alloc_assignment(0);
 74 
 75                         if (!border) {
 76                                 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
 77                                 return -1;
 78                         }
 79 
 80                         border->length = 64;
 81                         list_add(&border->head, &iface->ia_assignments);
 82                 } else
 83                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
 84 
 85                 set_border_assignment_size(iface, border);
 86         } else {
 87                 struct dhcp_assignment *c;
 88 
 89                 while (!list_empty(&iface->ia_assignments)) {
 90                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
 91                         free_assignment(c);
 92                 }
 93         }
 94 
 95         return 0;
 96 }
 97 
 98 
 99 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
100 {
101         struct interface *iface = info->iface;
102 
103         if (!iface || iface->dhcpv6 != MODE_SERVER)
104                 return;
105 
106         switch (event) {
107         case NETEV_ADDR6LIST_CHANGE:
108                 handle_addrlist_change(info);
109                 break;
110         default:
111                 break;
112         }
113 }
114 
115 
116 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
117 {
118         return (a->managed_size || a->length > prefix_length);
119 }
120 
121 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
122 {
123         return (addr->prefix <= 96 && addr->preferred_lt > (uint32_t)now);
124 }
125 
126 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
127 {
128         size_t i, m;
129 
130         for (i = 0, m = 0; i < addrlen; ++i) {
131                 if (addrs[i].preferred_lt > addrs[m].preferred_lt ||
132                                 (addrs[i].preferred_lt == addrs[m].preferred_lt &&
133                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
134                         m = i;
135         }
136 
137         return m;
138 }
139 
140 static int send_reconf(struct dhcp_assignment *assign)
141 {
142         struct {
143                 struct dhcpv6_client_header hdr;
144                 uint16_t srvid_type;
145                 uint16_t srvid_len;
146                 uint16_t duid_type;
147                 uint16_t hardware_type;
148                 uint8_t mac[6];
149                 uint16_t msg_type;
150                 uint16_t msg_len;
151                 uint8_t msg_id;
152                 struct dhcpv6_auth_reconfigure auth;
153                 uint16_t clid_type;
154                 uint16_t clid_len;
155                 uint8_t clid_data[128];
156         } __attribute__((packed)) reconf_msg = {
157                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
158                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
159                 .srvid_len = htons(10),
160                 .duid_type = htons(3),
161                 .hardware_type = htons(1),
162                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
163                 .msg_len = htons(1),
164                 .msg_id = DHCPV6_MSG_RENEW,
165                 .auth = {htons(DHCPV6_OPT_AUTH),
166                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
167                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
168                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
169                 .clid_len = htons(assign->clid_len),
170                 .clid_data = {0},
171         };
172         struct interface *iface = assign->iface;
173 
174         odhcpd_get_mac(iface, reconf_msg.mac);
175         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
176         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
177 
178         md5_ctx_t md5;
179         uint8_t secretbytes[64];
180         memset(secretbytes, 0, sizeof(secretbytes));
181         memcpy(secretbytes, assign->key, sizeof(assign->key));
182 
183         for (size_t i = 0; i < sizeof(secretbytes); ++i)
184                 secretbytes[i] ^= 0x36;
185 
186         md5_begin(&md5);
187         md5_hash(secretbytes, sizeof(secretbytes), &md5);
188         md5_hash(iov.iov_base, iov.iov_len, &md5);
189         md5_end(reconf_msg.auth.key, &md5);
190 
191         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
192                 secretbytes[i] ^= 0x36;
193                 secretbytes[i] ^= 0x5c;
194         }
195 
196         md5_begin(&md5);
197         md5_hash(secretbytes, sizeof(secretbytes), &md5);
198         md5_hash(reconf_msg.auth.key, 16, &md5);
199         md5_end(reconf_msg.auth.key, &md5);
200 
201         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
202 }
203 
204 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
205 {
206         if (a->managed_sock.fd.registered) {
207                 ustream_free(&a->managed_sock.stream);
208                 close(a->managed_sock.fd.fd);
209         }
210 
211         if ((a->flags & OAF_BOUND) && (a->flags & OAF_DHCPV6_PD))
212                 apply_lease(a, false);
213 
214         if (a->reconf_cnt)
215                 stop_reconf(a);
216 
217         free(a->managed);
218 }
219 
220 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
221                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
222 {
223         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
224         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
225         size_t m = get_preferred_addr(addrs, addrlen);
226 
227         for (size_t i = 0; i < addrlen; ++i) {
228                 struct in6_addr addr;
229                 uint32_t preferred_lt, valid_lt;
230                 int prefix = c->managed ? addrs[i].prefix : c->length;
231 
232                 if (!valid_addr(&addrs[i], now))
233                         continue;
234 
235                 /* Filter Out Prefixes */
236                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
237                         char addrbuf[INET6_ADDRSTRLEN];
238                         syslog(LOG_INFO, "Address %s filtered out on %s",
239                                 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
240                                 iface->name);
241                         continue;
242                 }
243 
244                 addr = addrs[i].addr.in6;
245                 preferred_lt = addrs[i].preferred_lt;
246                 valid_lt = addrs[i].valid_lt;
247 
248                 if (c->flags & OAF_DHCPV6_NA) {
249                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
250                                 continue;
251 
252                         addr.s6_addr32[2] = htonl(c->assigned_host_id >> 32);
253                         addr.s6_addr32[3] = htonl(c->assigned_host_id & UINT32_MAX);
254                 } else {
255                         if (!valid_prefix_length(c, addrs[i].prefix))
256                                 continue;
257 
258                         addr.s6_addr32[1] |= htonl(c->assigned_subnet_id);
259                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
260                 }
261 
262                 if (preferred_lt > (uint32_t)c->preferred_until)
263                         preferred_lt = c->preferred_until;
264 
265                 if (preferred_lt > (uint32_t)c->valid_until)
266                         preferred_lt = c->valid_until;
267 
268                 if (preferred_lt != UINT32_MAX)
269                         preferred_lt -= now;
270 
271                 if (valid_lt > (uint32_t)c->valid_until)
272                         valid_lt = c->valid_until;
273 
274                 if (valid_lt != UINT32_MAX)
275                         valid_lt -= now;
276 
277                 func(&addr, prefix, preferred_lt, valid_lt, arg);
278         }
279 }
280 
281 struct write_ctxt {
282         FILE *fp;
283         md5_ctx_t md5;
284         struct dhcp_assignment *c;
285         struct interface *iface;
286         char *buf;
287         int buf_len;
288         int buf_idx;
289 };
290 
291 static void dhcpv6_write_ia_addrhosts(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
292                                 _unused uint32_t valid_lt, void *arg)
293 {
294         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
295         char ipbuf[INET6_ADDRSTRLEN];
296 
297         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
298             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
299                 inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
300                 fputs(ipbuf, ctxt->fp);
301 
302                 char b[256];
303                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
304                                 ctxt->iface->search, b, sizeof(b)) > 0)
305                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
306 
307                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
308         }
309 }
310 
311 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
312                                 _unused uint32_t valid_lt, void *arg)
313 {
314         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
315         char ipbuf[INET6_ADDRSTRLEN];
316 
317         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
318 
319         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
320             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
321                 fputs(ipbuf, ctxt->fp);
322 
323                 char b[256];
324                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
325                                 ctxt->iface->search, b, sizeof(b)) > 0)
326                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
327 
328                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
329                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
330                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
331         }
332 
333         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
334                                         "%s/%d ", ipbuf, prefix);
335 }
336 
337 static void dhcpv6_ia_write_hostsfile(time_t now)
338 {
339         struct write_ctxt ctxt;
340 
341         unsigned hostsfile_strlen = strlen(config.dhcp_hostsfile) + 1;
342         unsigned tmp_hostsfile_strlen = hostsfile_strlen + 1; /* space for . */
343         char *tmp_hostsfile = alloca(tmp_hostsfile_strlen);
344 
345         char *dir_hostsfile;
346         char *base_hostsfile;
347         char *pdir_hostsfile;
348         char *pbase_hostsfile;
349 
350         int fd, ret;
351 
352         dir_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
353         base_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
354 
355         pdir_hostsfile = dirname(dir_hostsfile);
356         pbase_hostsfile = basename(base_hostsfile);
357 
358         snprintf(tmp_hostsfile, tmp_hostsfile_strlen, "%s/.%s", pdir_hostsfile, pbase_hostsfile);
359 
360         free(dir_hostsfile);
361         free(base_hostsfile);
362 
363         fd = open(tmp_hostsfile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
364         if (fd < 0)
365                 return;
366 
367         ret = lockf(fd, F_LOCK, 0);
368         if (ret < 0) {
369                 close(fd);
370                 return;
371         }
372 
373         if (ftruncate(fd, 0) < 0) {}
374 
375         ctxt.fp = fdopen(fd, "w");
376         if (!ctxt.fp) {
377                 close(fd);
378                 return;
379         }
380 
381         avl_for_each_element(&interfaces, ctxt.iface, avl) {
382                 if (ctxt.iface->dhcpv6 != MODE_SERVER &&
383                                 ctxt.iface->dhcpv4 != MODE_SERVER)
384                         continue;
385 
386                 if (ctxt.iface->dhcpv6 == MODE_SERVER) {
387                         list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
388                                 if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
389                                         continue;
390 
391                                 if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
392                                         dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
393                                                                 dhcpv6_write_ia_addrhosts, &ctxt);
394                         }
395                 }
396 
397                 if (ctxt.iface->dhcpv4 == MODE_SERVER) {
398                         struct dhcp_assignment *c;
399 
400                         list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
401                                 if (!(c->flags & OAF_BOUND))
402                                         continue;
403 
404                                 char ipbuf[INET6_ADDRSTRLEN];
405                                 struct in_addr addr = {.s_addr = c->addr};
406                                 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
407 
408                                 if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
409                                         fputs(ipbuf, ctxt.fp);
410 
411                                         char b[256];
412 
413                                         if (dn_expand(ctxt.iface->search,
414                                                         ctxt.iface->search + ctxt.iface->search_len,
415                                                         ctxt.iface->search, b, sizeof(b)) > 0)
416                                                 fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
417 
418                                         fprintf(ctxt.fp, "\t%s\n", c->hostname);
419                                 }
420                         }
421                 }
422         }
423 
424         fclose(ctxt.fp);
425 
426         rename(tmp_hostsfile, config.dhcp_hostsfile);
427 }
428 
429 void dhcpv6_ia_write_statefile(void)
430 {
431         struct write_ctxt ctxt;
432 
433         md5_begin(&ctxt.md5);
434 
435         if (config.dhcp_statefile) {
436                 unsigned statefile_strlen = strlen(config.dhcp_statefile) + 1;
437                 unsigned tmp_statefile_strlen = statefile_strlen + 1; /* space for . */
438                 char *tmp_statefile = alloca(tmp_statefile_strlen);
439 
440                 char *dir_statefile;
441                 char *base_statefile;
442                 char *pdir_statefile;
443                 char *pbase_statefile;
444 
445                 time_t now = odhcpd_time(), wall_time = time(NULL);
446                 int fd, ret;
447                 char leasebuf[512];
448 
449                 dir_statefile = strndup(config.dhcp_statefile, statefile_strlen);
450                 base_statefile = strndup(config.dhcp_statefile, statefile_strlen);
451 
452                 pdir_statefile = dirname(dir_statefile);
453                 pbase_statefile = basename(base_statefile);
454 
455                 snprintf(tmp_statefile, tmp_statefile_strlen, "%s/.%s", pdir_statefile, pbase_statefile);
456 
457                 free(dir_statefile);
458                 free(base_statefile);
459 
460                 fd = open(tmp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
461                 if (fd < 0)
462                         return;
463 
464                 ret = lockf(fd, F_LOCK, 0);
465                 if (ret < 0) {
466                         close(fd);
467                         return;
468                 }
469 
470                 if (ftruncate(fd, 0) < 0) {}
471 
472                 ctxt.fp = fdopen(fd, "w");
473                 if (!ctxt.fp) {
474                         close(fd);
475                         return;
476                 }
477 
478                 ctxt.buf = leasebuf;
479                 ctxt.buf_len = sizeof(leasebuf);
480 
481                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
482                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
483                                         ctxt.iface->dhcpv4 != MODE_SERVER)
484                                 continue;
485 
486                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
487                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
488                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
489                                                 continue;
490 
491                                         char duidbuf[264];
492 
493                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
494 
495                                         /* iface DUID iaid hostname lifetime assigned_host_id length [addrs...] */
496                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" ",
497                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
498                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
499                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
500                                                                 (ctxt.c->valid_until > now ?
501                                                                         (int64_t)(ctxt.c->valid_until - now + wall_time) :
502                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
503 
504                                         if (ctxt.c->flags & OAF_DHCPV6_NA)
505                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
506                                                                          "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
507                                         else
508                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
509                                                                          "%" PRIx32" %u ", ctxt.c->assigned_subnet_id, (unsigned)ctxt.c->length);
510 
511                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
512                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
513                                                                         dhcpv6_write_ia_addr, &ctxt);
514 
515                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
516                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
517                                 }
518                         }
519 
520                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
521                                 struct dhcp_assignment *c;
522 
523                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
524                                         if (!(c->flags & OAF_BOUND))
525                                                 continue;
526 
527                                         char ipbuf[INET6_ADDRSTRLEN];
528                                         char duidbuf[16];
529                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
530 
531                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
532                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
533                                                                 ctxt.iface->ifname, duidbuf,
534                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
535                                                                 (c->hostname ? c->hostname : "-"),
536                                                                 (c->valid_until > now ?
537                                                                         (int64_t)(c->valid_until - now + wall_time) :
538                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
539                                                                 ntohl(c->addr));
540 
541                                         struct in_addr addr = {.s_addr = c->addr};
542                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
543 
544                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
545                                                 fputs(ipbuf, ctxt.fp);
546 
547                                                 char b[256];
548                                                 if (dn_expand(ctxt.iface->search,
549                                                                 ctxt.iface->search + ctxt.iface->search_len,
550                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
551                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
552 
553                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
554                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
555                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
556                                         }
557 
558                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
559                                                                         ctxt.buf_len - ctxt.buf_idx,
560                                                                         "%s/32 ", ipbuf);
561                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
562                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
563                                 }
564                         }
565                 }
566 
567                 fclose(ctxt.fp);
568 
569                 uint8_t newmd5[16];
570                 md5_end(newmd5, &ctxt.md5);
571 
572                 rename(tmp_statefile, config.dhcp_statefile);
573 
574                 if (memcmp(newmd5, statemd5, sizeof(newmd5))) {
575                         memcpy(statemd5, newmd5, sizeof(statemd5));
576 
577                         if (config.dhcp_hostsfile)
578                                 dhcpv6_ia_write_hostsfile(now);
579 
580                         if (config.dhcp_cb) {
581                                 char *argv[2] = {config.dhcp_cb, NULL};
582                                 if (!vfork()) {
583                                         execv(argv[0], argv);
584                                         _exit(128);
585                                 }
586                         }
587                 }
588         }
589 }
590 
591 static void __apply_lease(struct dhcp_assignment *a,
592                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
593 {
594         if (a->flags & OAF_DHCPV6_NA)
595                 return;
596 
597         for (ssize_t i = 0; i < addr_len; ++i) {
598                 struct in6_addr prefix;
599 
600                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], a->iface))
601                         continue;
602 
603                 prefix = addrs[i].addr.in6;
604                 prefix.s6_addr32[1] |= htonl(a->assigned_subnet_id);
605                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
606                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
607                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
608         }
609 }
610 
611 static void apply_lease(struct dhcp_assignment *a, bool add)
612 {
613         struct interface *iface = a->iface;
614         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
615         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
616 
617         __apply_lease(a, addrs, addrlen, add);
618 }
619 
620 /* Set border assignment size based on the IPv6 address prefixes */
621 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
622 {
623         time_t now = odhcpd_time();
624         int minprefix = -1;
625 
626         for (size_t i = 0; i < iface->addr6_len; ++i) {
627                 struct odhcpd_ipaddr *addr = &iface->addr6[i];
628 
629                 if (ADDR_MATCH_PIO_FILTER(addr, iface))
630                         continue;
631 
632                 if (addr->preferred_lt > (uint32_t)now &&
633                     addr->prefix < 64 &&
634                     addr->prefix > minprefix)
635                         minprefix = addr->prefix;
636         }
637 
638         if (minprefix > 32 && minprefix <= 64)
639                 b->assigned_subnet_id = 1U << (64 - minprefix);
640         else
641                 b->assigned_subnet_id = 0;
642 }
643 
644 /* More data was received from TCP connection */
645 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
646 {
647         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
648         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
649         time_t now = odhcpd_time();
650         bool first = c->managed_size < 0;
651 
652         for (;;) {
653                 int pending;
654                 char *data = ustream_get_read_buf(s, &pending);
655                 char *end = memmem(data, pending, "\n\n", 2);
656 
657                 if (!end)
658                         break;
659 
660                 end += 2;
661                 end[-1] = 0;
662 
663                 c->managed_size = 0;
664                 if (c->accept_reconf)
665                         c->reconf_cnt = 1;
666 
667                 char *saveptr;
668                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
669                         struct odhcpd_ipaddr *n;
670                         char *saveptr2, *x;
671 
672                         n = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
673                         if (!n)
674                                 continue;
675                         c->managed = n;
676                         n = &c->managed[c->managed_size];
677 
678                         x = strtok_r(line, ",", &saveptr2);
679                         if (odhcpd_parse_addr6_prefix(x, &n->addr.in6, &n->prefix))
680                                 continue;
681 
682                         x = strtok_r(NULL, ",", &saveptr2);
683                         if (sscanf(x, "%u", &n->preferred_lt) < 1)
684                                 continue;
685 
686                         x = strtok_r(NULL, ",", &saveptr2);
687                         if (sscanf(x, "%u", &n->valid_lt) < 1)
688                                 continue;
689 
690                         if (n->preferred_lt > n->valid_lt)
691                                 continue;
692 
693                         if (UINT32_MAX - now < n->preferred_lt)
694                                 n->preferred_lt = UINT32_MAX;
695                         else
696                                 n->preferred_lt += now;
697 
698                         if (UINT32_MAX - now < n->valid_lt)
699                                 n->valid_lt = UINT32_MAX;
700                         else
701                                 n->valid_lt += now;
702 
703                         n->dprefix = 0;
704 
705                         ++c->managed_size;
706                 }
707 
708                 ustream_consume(s, end - data);
709         }
710 
711         if (first && c->managed_size == 0)
712                 free_assignment(c);
713         else if (first)
714                 c->valid_until = now + 150;
715 }
716 
717 
718 /* TCP transmission has ended, either because of success or timeout or other error */
719 static void managed_handle_pd_done(struct ustream *s)
720 {
721         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
722         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
723 
724         c->valid_until = odhcpd_time() + 15;
725 
726         c->managed_size = 0;
727 
728         if (c->accept_reconf)
729                 c->reconf_cnt = 1;
730 }
731 
732 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
733 {
734         struct dhcp_assignment *c;
735 
736         if (iface->dhcpv6_pd_manager[0]) {
737                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
738                 if (fd >= 0) {
739                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
740                         char iaidbuf[298];
741 
742                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
743 
744                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
745                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
746                         ustream_fd_init(&assign->managed_sock, fd);
747                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
748                                         iaidbuf, assign->iaid, assign->length);
749                         ustream_write_pending(&assign->managed_sock.stream);
750                         assign->managed_size = -1;
751 
752                         assign->valid_until = odhcpd_time() + 15;
753 
754                         list_add(&assign->head, &iface->ia_assignments);
755 
756                         /* Wait initial period of up to 250ms for immediate assignment */
757                         if (poll(&pfd, 1, 250) < 0) {
758                                 syslog(LOG_ERR, "poll(): %m");
759                                 return false;
760                         }
761 
762                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
763 
764                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
765                                 return true;
766                 }
767 
768                 return false;
769         } else if (iface->addr6_len < 1)
770                 return false;
771 
772         /* Try honoring the hint first */
773         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
774         if (assign->assigned_subnet_id) {
775                 list_for_each_entry(c, &iface->ia_assignments, head) {
776                         if (c->flags & OAF_DHCPV6_NA)
777                                 continue;
778 
779                         if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
780                                 list_add_tail(&assign->head, &c->head);
781 
782                                 if (assign->flags & OAF_BOUND)
783                                         apply_lease(assign, true);
784 
785                                 return true;
786                         }
787 
788                         current = (c->assigned_subnet_id + (1 << (64 - c->length)));
789                 }
790         }
791 
792         /* Fallback to a variable assignment */
793         current = 1;
794         list_for_each_entry(c, &iface->ia_assignments, head) {
795                 if (c->flags & OAF_DHCPV6_NA)
796                         continue;
797 
798                 current = (current + asize) & (~asize);
799 
800                 if (current + asize < c->assigned_subnet_id) {
801                         assign->assigned_subnet_id = current;
802                         list_add_tail(&assign->head, &c->head);
803 
804                         if (assign->flags & OAF_BOUND)
805                                 apply_lease(assign, true);
806 
807                         return true;
808                 }
809 
810                 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
811         }
812 
813         return false;
814 }
815 
816 /* Check iid against reserved IPv6 interface identifiers.
817    Refer to:
818      http://www.iana.org/assignments/ipv6-interface-ids */
819 static bool is_reserved_ipv6_iid(uint64_t iid)
820 {
821         if (iid == 0x0000000000000000)
822                 /* Subnet-Router Anycast [RFC4291] */
823                 return true;
824 
825         if ((iid & 0xFFFFFFFFFF000000) == 0x02005EFFFE000000)
826                 /* Reserved IPv6 Interface Identifiers corresponding
827                    to the IANA Ethernet Block [RFC4291] */
828                 return true;
829 
830         if ((iid & 0xFFFFFFFFFFFFFF80) == 0xFDFFFFFFFFFFFF80)
831                 /* Reserved Subnet Anycast Addresses [RFC2526] */
832                 return true;
833 
834         return false;
835 }
836 
837 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
838 {
839         struct dhcp_assignment *c;
840         uint32_t seed = 0;
841 
842         /* Preconfigured assignment by static lease */
843         if (a->assigned_host_id) {
844                 list_for_each_entry(c, &iface->ia_assignments, head) {
845                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
846                                 list_add_tail(&a->head, &c->head);
847                                 return true;
848                         } else if (c->assigned_host_id == a->assigned_host_id)
849                                 return false;
850                 }
851         }
852 
853         /* Seed RNG with checksum of DUID */
854         for (size_t i = 0; i < a->clid_len; ++i)
855                 seed += a->clid_data[i];
856         srandom(seed);
857 
858         /* Try to assign up to 100x */
859         for (size_t i = 0; i < 100; ++i) {
860                 uint64_t try;
861 
862                 if (iface->dhcpv6_hostid_len > 32) {
863                         uint32_t mask_high;
864 
865                         if (iface->dhcpv6_hostid_len >= 64)
866                                 mask_high = UINT32_MAX;
867                         else
868                                 mask_high = (1 << (iface->dhcpv6_hostid_len - 32)) - 1;
869 
870                         do {
871                                 try = (uint32_t)random();
872                                 try |= (uint64_t)((uint32_t)random() & mask_high) << 32;
873                         } while (try < 0x100);
874                 } else {
875                         uint32_t mask_low;
876 
877                         if (iface->dhcpv6_hostid_len == 32)
878                                 mask_low = UINT32_MAX;
879                         else
880                                 mask_low = (1 << iface->dhcpv6_hostid_len) - 1;
881                         do try = ((uint32_t)random()) & mask_low; while (try < 0x100);
882                 }
883 
884                 if (is_reserved_ipv6_iid(try))
885                         continue;
886 
887                 if (config_find_lease_by_hostid(try))
888                         continue;
889 
890                 list_for_each_entry(c, &iface->ia_assignments, head) {
891                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
892                                 a->assigned_host_id = try;
893                                 list_add_tail(&a->head, &c->head);
894                                 return true;
895                         } else if (c->assigned_host_id == try)
896                                 break;
897                 }
898         }
899 
900         return false;
901 }
902 
903 static void handle_addrlist_change(struct netevent_handler_info *info)
904 {
905         struct interface *iface = info->iface;
906         struct dhcp_assignment *c, *d, *border = list_last_entry(
907                         &iface->ia_assignments, struct dhcp_assignment, head);
908         struct list_head reassign = LIST_HEAD_INIT(reassign);
909         time_t now = odhcpd_time();
910 
911         list_for_each_entry(c, &iface->ia_assignments, head) {
912                 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
913                                 && (c->flags & OAF_BOUND))
914                         __apply_lease(c, info->addrs_old.addrs,
915                                         info->addrs_old.len, false);
916         }
917 
918         set_border_assignment_size(iface, border);
919 
920         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
921                 if (c->clid_len == 0 ||
922                     !(c->flags & OAF_DHCPV6_PD) ||
923                     (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
924                     c->managed_size)
925                         continue;
926 
927                 if (c->assigned_subnet_id >= border->assigned_subnet_id)
928                         list_move(&c->head, &reassign);
929                 else if (c->flags & OAF_BOUND)
930                         apply_lease(c, true);
931 
932                 if (c->accept_reconf && c->reconf_cnt == 0) {
933                         struct dhcp_assignment *a;
934 
935                         start_reconf(c);
936 
937                         /* Leave all other assignments of that client alone */
938                         list_for_each_entry(a, &iface->ia_assignments, head)
939                                 if (a != c && a->clid_len == c->clid_len &&
940                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
941                                         a->reconf_cnt = INT_MAX;
942                 }
943         }
944 
945         while (!list_empty(&reassign)) {
946                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
947                 list_del_init(&c->head);
948                 if (!assign_pd(iface, c))
949                         free_assignment(c);
950         }
951 
952         dhcpv6_ia_write_statefile();
953 }
954 
955 static void reconf_timeout_cb(struct uloop_timeout *event)
956 {
957         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
958 
959         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
960                 send_reconf(a);
961                 uloop_timeout_set(&a->reconf_timer,
962                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
963                 a->reconf_cnt++;
964         } else
965                 stop_reconf(a);
966 }
967 
968 static void start_reconf(struct dhcp_assignment *a)
969 {
970         uloop_timeout_set(&a->reconf_timer,
971                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
972         a->reconf_timer.cb = reconf_timeout_cb;
973         a->reconf_cnt++;
974 
975         send_reconf(a);
976 }
977 
978 static void stop_reconf(struct dhcp_assignment *a)
979 {
980         uloop_timeout_cancel(&a->reconf_timer);
981         a->reconf_cnt = 0;
982         a->reconf_timer.cb = NULL;
983 }
984 
985 static void valid_until_cb(struct uloop_timeout *event)
986 {
987         struct interface *iface;
988         time_t now = odhcpd_time();
989 
990         avl_for_each_element(&interfaces, iface, avl) {
991                 struct dhcp_assignment *a, *n;
992 
993                 if (iface->dhcpv6 != MODE_SERVER)
994                         continue;
995 
996                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
997                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
998                                 free_assignment(a);
999                 }
1000         }
1001         uloop_timeout_set(event, 1000);
1002 }
1003 
1004 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
1005                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1006                 struct interface *iface, bool request)
1007 {
1008         struct dhcpv6_ia_hdr o_ia = {
1009                 .type = ia->type,
1010                 .len = 0,
1011                 .iaid = ia->iaid,
1012                 .t1 = 0,
1013                 .t2 = 0,
1014         };
1015         size_t ia_len = sizeof(o_ia);
1016         time_t now = odhcpd_time();
1017 
1018         if (buflen < ia_len)
1019                 return 0;
1020 
1021         if (status) {
1022                 struct __attribute__((packed)) {
1023                         uint16_t type;
1024                         uint16_t len;
1025                         uint16_t val;
1026                 } o_status = {
1027                         .type = htons(DHCPV6_OPT_STATUS),
1028                         .len = htons(sizeof(o_status) - 4),
1029                         .val = htons(status),
1030                 };
1031 
1032                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
1033                 ia_len += sizeof(o_status);
1034 
1035                 o_ia.len = htons(ia_len - 4);
1036                 memcpy(buf, &o_ia, sizeof(o_ia));
1037 
1038                 return ia_len;
1039         }
1040 
1041         if (a) {
1042                 uint32_t leasetime, preferred_lt;
1043 
1044                 if (a->leasetime) {
1045                         leasetime = a->leasetime;
1046                         preferred_lt = a->leasetime;
1047                 } else {
1048                         leasetime = iface->dhcp_leasetime;
1049                         preferred_lt = iface->preferred_lifetime;
1050                 }
1051 
1052                 uint32_t valid_lt = leasetime;
1053 
1054                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1055                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1056                 size_t m = get_preferred_addr(addrs, addrlen);
1057 
1058                 for (size_t i = 0; i < addrlen; ++i) {
1059                         uint32_t prefix_preferred_lt, prefix_valid_lt;
1060 
1061                         if (!valid_addr(&addrs[i], now))
1062                                 continue;
1063 
1064                         /* Filter Out Prefixes */
1065                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
1066                                 char addrbuf[INET6_ADDRSTRLEN];
1067                                 syslog(LOG_INFO, "Address %s filtered out on %s",
1068                                         inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
1069                                         iface->name);
1070                                 continue;
1071                         }
1072 
1073                         prefix_preferred_lt = addrs[i].preferred_lt;
1074                         prefix_valid_lt = addrs[i].valid_lt;
1075 
1076                         if (prefix_preferred_lt != UINT32_MAX)
1077                                 prefix_preferred_lt -= now;
1078 
1079                         if (prefix_preferred_lt > preferred_lt)
1080                                 prefix_preferred_lt = preferred_lt;
1081 
1082                         if (prefix_valid_lt != UINT32_MAX)
1083                                 prefix_valid_lt -= now;
1084 
1085                         if (prefix_valid_lt > leasetime)
1086                                 prefix_valid_lt = leasetime;
1087 
1088                         if (prefix_preferred_lt > prefix_valid_lt)
1089                                 prefix_preferred_lt = prefix_valid_lt;
1090 
1091                         if (a->flags & OAF_DHCPV6_PD) {
1092                                 struct dhcpv6_ia_prefix o_ia_p = {
1093                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
1094                                         .len = htons(sizeof(o_ia_p) - 4),
1095                                         .preferred_lt = htonl(prefix_preferred_lt),
1096                                         .valid_lt = htonl(prefix_valid_lt),
1097                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
1098                                         .addr = addrs[i].addr.in6,
1099                                 };
1100 
1101                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1102                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
1103 
1104                                 if (!valid_prefix_length(a, addrs[i].prefix))
1105                                         continue;
1106 
1107                                 if (buflen < ia_len + sizeof(o_ia_p))
1108                                         return 0;
1109 
1110                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1111                                 ia_len += sizeof(o_ia_p);
1112                         }
1113 
1114                         if (a->flags & OAF_DHCPV6_NA) {
1115                                 struct dhcpv6_ia_addr o_ia_a = {
1116                                         .type = htons(DHCPV6_OPT_IA_ADDR),
1117                                         .len = htons(sizeof(o_ia_a) - 4),
1118                                         .addr = addrs[i].addr.in6,
1119                                         .preferred_lt = htonl(prefix_preferred_lt),
1120                                         .valid_lt = htonl(prefix_valid_lt)
1121                                 };
1122 
1123                                 o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1124                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1125 
1126                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
1127                                         continue;
1128 
1129                                 if (buflen < ia_len + sizeof(o_ia_a))
1130                                         return 0;
1131 
1132                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1133                                 ia_len += sizeof(o_ia_a);
1134                         }
1135 
1136                         /* Calculate T1 / T2 based on non-deprecated addresses */
1137                         if (prefix_preferred_lt > 0) {
1138                                 if (prefix_preferred_lt < preferred_lt)
1139                                         preferred_lt = prefix_preferred_lt;
1140 
1141                                 if (prefix_valid_lt < valid_lt)
1142                                         valid_lt = prefix_valid_lt;
1143                         }
1144                 }
1145 
1146                 if (!INFINITE_VALID(a->valid_until))
1147                         /* UINT32_MAX is RFC defined as infinite lease-time */
1148                         a->valid_until = (valid_lt == UINT32_MAX) ? 0 : valid_lt + now;
1149 
1150                 if (!INFINITE_VALID(a->preferred_until))
1151                         /* UINT32_MAX is RFC defined as infinite lease-time */
1152                         a->preferred_until = (preferred_lt == UINT32_MAX) ? 0 : preferred_lt + now;
1153 
1154                 o_ia.t1 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 5 / 10);
1155                 o_ia.t2 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 8 / 10);
1156 
1157                 if (!o_ia.t1)
1158                         o_ia.t1 = htonl(1);
1159 
1160                 if (!o_ia.t2)
1161                         o_ia.t2 = htonl(1);
1162         }
1163 
1164         if (!request) {
1165                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1166                 uint16_t otype, olen;
1167 
1168                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1169                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
1170                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
1171                         bool found = false;
1172 
1173                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
1174                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
1175                                 continue;
1176 
1177                         if (a) {
1178                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1179                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1180 
1181                                 for (size_t i = 0; i < addrlen; ++i) {
1182                                         struct in6_addr addr;
1183 
1184                                         if (!valid_addr(&addrs[i], now))
1185                                                 continue;
1186 
1187                                         if (!valid_prefix_length(a, addrs[i].prefix))
1188                                                 continue;
1189 
1190                                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1191                                                 continue;
1192 
1193                                         addr = addrs[i].addr.in6;
1194                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1195                                                 addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1196                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1197 
1198                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
1199                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
1200                                                         found = true;
1201                                         } else {
1202                                                 addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1203                                                 addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1204 
1205                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
1206                                                         found = true;
1207                                         }
1208                                 }
1209                         }
1210 
1211                         if (!found) {
1212                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1213                                         struct dhcpv6_ia_prefix o_ia_p = {
1214                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
1215                                                 .len = htons(sizeof(o_ia_p) - 4),
1216                                                 .preferred_lt = 0,
1217                                                 .valid_lt = 0,
1218                                                 .prefix = ia_p->prefix,
1219                                                 .addr = ia_p->addr,
1220                                         };
1221 
1222                                         if (buflen < ia_len + sizeof(o_ia_p))
1223                                                 return 0;
1224 
1225                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1226                                         ia_len += sizeof(o_ia_p);
1227                                 } else {
1228                                         struct dhcpv6_ia_addr o_ia_a = {
1229                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
1230                                                 .len = htons(sizeof(o_ia_a) - 4),
1231                                                 .addr = ia_a->addr,
1232                                                 .preferred_lt = 0,
1233                                                 .valid_lt = 0,
1234                                         };
1235 
1236                                         if (buflen < ia_len + sizeof(o_ia_a))
1237                                                 continue;
1238 
1239                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1240                                         ia_len += sizeof(o_ia_a);
1241                                 }
1242                         }
1243                 }
1244         }
1245 
1246         o_ia.len = htons(ia_len - 4);
1247         memcpy(buf, &o_ia, sizeof(o_ia));
1248         return ia_len;
1249 }
1250 
1251 struct log_ctxt {
1252         char *buf;
1253         int buf_len;
1254         int buf_idx;
1255 };
1256 
1257 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
1258                                 _unused uint32_t valid_lt, void *arg)
1259 {
1260         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1261         char addrbuf[INET6_ADDRSTRLEN];
1262 
1263         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1264         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1265                                         "%s/%d ", addrbuf, prefix);
1266 }
1267 
1268 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1269                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1270 {
1271         const char *type = "UNKNOWN";
1272         const char *status = "UNKNOWN";
1273 
1274         switch (msgtype) {
1275         case DHCPV6_MSG_SOLICIT:
1276                 type = "SOLICIT";
1277                 break;
1278         case DHCPV6_MSG_REQUEST:
1279                 type = "REQUEST";
1280                 break;
1281         case DHCPV6_MSG_CONFIRM:
1282                 type = "CONFIRM";
1283                 break;
1284         case DHCPV6_MSG_RENEW:
1285                 type = "RENEW";
1286                 break;
1287         case DHCPV6_MSG_REBIND:
1288                 type = "REBIND";
1289                 break;
1290         case DHCPV6_MSG_RELEASE:
1291                 type = "RELEASE";
1292                 break;
1293         case DHCPV6_MSG_DECLINE:
1294                 type = "DECLINE";
1295                 break;
1296         }
1297 
1298         switch (code) {
1299         case DHCPV6_STATUS_OK:
1300                 status = "ok";
1301                 break;
1302         case DHCPV6_STATUS_NOADDRSAVAIL:
1303                 status = "no addresses available";
1304                 break;
1305         case DHCPV6_STATUS_NOBINDING:
1306                 status = "no binding";
1307                 break;
1308         case DHCPV6_STATUS_NOTONLINK:
1309                 status = "not on-link";
1310                 break;
1311         case DHCPV6_STATUS_NOPREFIXAVAIL:
1312                 status = "no prefix available";
1313                 break;
1314         }
1315 
1316         char leasebuf[256] = "";
1317 
1318         if (a) {
1319                 struct log_ctxt ctxt = {.buf = leasebuf,
1320                                         .buf_len = sizeof(leasebuf),
1321                                         .buf_idx = 0 };
1322 
1323                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1324         }
1325 
1326         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1327                          duidbuf, iface->name, status, leasebuf);
1328 }
1329 
1330 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1331                 struct interface *iface)
1332 {
1333         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1334         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1335         time_t now = odhcpd_time();
1336         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1337         uint16_t otype, olen;
1338         bool onlink = true;
1339 
1340         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1341                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1342                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1343 
1344                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1345                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1346                         continue;
1347 
1348                 onlink = false;
1349                 for (size_t i = 0; i < addrlen; ++i) {
1350                         if (!valid_addr(&addrs[i], now))
1351                                 continue;
1352 
1353                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1354                                 continue;
1355 
1356                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1357                                 if (p->prefix < addrs[i].prefix ||
1358                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1359                                         continue;
1360 
1361                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1362                                 continue;
1363 
1364                         onlink = true;
1365                 }
1366 
1367                 if (!onlink)
1368                         break;
1369         }
1370 
1371         return onlink;
1372 }
1373 
1374 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1375                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1376 {
1377         struct lease *l;
1378         struct dhcp_assignment *first = NULL;
1379         const struct dhcpv6_client_header *hdr = data;
1380         time_t now = odhcpd_time();
1381         uint16_t otype, olen, clid_len = 0;
1382         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1383         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1384         size_t hostname_len = 0, response_len = 0;
1385         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1386         char duidbuf[261], hostname[256];
1387 
1388         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1389                 if (otype == DHCPV6_OPT_CLIENTID) {
1390                         clid_data = odata;
1391                         clid_len = olen;
1392 
1393                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1394                                 memcpy(mac, &odata[8], sizeof(mac));
1395                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1396                                 memcpy(mac, &odata[4], sizeof(mac));
1397 
1398                         if (olen <= 130)
1399                                 odhcpd_hexlify(duidbuf, odata, olen);
1400                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1401                         uint8_t fqdn_buf[256];
1402                         memcpy(fqdn_buf, odata, olen);
1403                         fqdn_buf[olen++] = 0;
1404 
1405                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1406                                 hostname_len = strcspn(hostname, ".");
1407                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1408                         accept_reconf = true;
1409                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1410                         rapid_commit = true;
1411         }
1412 
1413         if (!clid_data || !clid_len || clid_len > 130)
1414                 goto out;
1415 
1416         l = config_find_lease_by_duid(clid_data, clid_len);
1417         if (!l)
1418                 l = config_find_lease_by_mac(mac);
1419 
1420         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1421                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1422                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1423                 bool ia_addr_present = false;
1424                 if (!is_pd && !is_na)
1425                         continue;
1426 
1427                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1428                 size_t ia_response_len = 0;
1429                 uint8_t reqlen = (is_pd) ? 62 : 128;
1430                 uint32_t reqhint = 0;
1431 
1432                 /* Parse request hint for IA-PD */
1433                 if (is_pd) {
1434                         uint8_t *sdata;
1435                         uint16_t stype, slen;
1436                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1437                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1438                                         continue;
1439 
1440                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1441                                 if (p->prefix) {
1442                                         reqlen = p->prefix;
1443                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1444                                         if (reqlen > 32 && reqlen <= 64)
1445                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1446                                 }
1447                         }
1448 
1449                         if (reqlen > 64)
1450                                 reqlen = 64;
1451 
1452                         /*
1453                          * A requesting router can include a desired prefix length for its
1454                          * delegation.  The delegating router (us) is not required to honor
1455                          * the hint (RFC3633, section 11.2, we MAY choose to use the
1456                          * information in the option; RFC8168, section 3.2 has several SHOULDs
1457                          * about desired choices for selecting a prefix to delegate).
1458                          *
1459                          * We support a policy setting to conserve prefix space, which purposely
1460                          * assigns prefixes that might not match the requesting router's hint.
1461                          *
1462                          * If the minimum prefix length is set in this interface's
1463                          * configuration, we use it as a floor for the requested (hinted)
1464                          * prefix length.  This allows us to conserve prefix space so that
1465                          * any single router can't grab too much of it.  Consider if we have
1466                          * an interface with a /56 prefix.  A requesting router could ask for
1467                          * a /58 and take 1/4 of our total address space.  But if we set a
1468                          * minimum of /60, we can limit each requesting router to get only
1469                          * 1/16 of our total address space.
1470                          */
1471                         if (iface->dhcpv6_pd_min_len && reqlen < iface->dhcpv6_pd_min_len) {
1472                             syslog(LOG_INFO, "clamping requested PD from %d to %d",
1473                                    reqlen, iface->dhcpv6_pd_min_len);
1474                             reqlen = iface->dhcpv6_pd_min_len;
1475                         }
1476                 } else if (is_na) {
1477                         uint8_t *sdata;
1478                         uint16_t stype, slen;
1479                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1480                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1481                                         continue;
1482 
1483                                 ia_addr_present = true;
1484                         }
1485                 }
1486 
1487                 /* Find assignment */
1488                 struct dhcp_assignment *c, *a = NULL;
1489                 list_for_each_entry(c, &iface->ia_assignments, head) {
1490                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1491                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1492                             ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1493                                 a = c;
1494 
1495                                 /* Reset state */
1496                                 if (a->flags & OAF_BOUND)
1497                                         apply_lease(a, false);
1498 
1499                                 stop_reconf(a);
1500                                 break;
1501                         }
1502                 }
1503 
1504                 if (l && a && a->lease != l) {
1505                         free_assignment(a);
1506                         a = NULL;
1507                 }
1508 
1509                 /* Generic message handling */
1510                 uint16_t status = DHCPV6_STATUS_OK;
1511                 if (a && a->managed_size < 0)
1512                         return -1;
1513 
1514                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1515                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1516                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1517                         bool assigned = !!a;
1518 
1519                         if (!a) {
1520                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1521                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1522                                         /* Create new binding */
1523                                         a = alloc_assignment(clid_len);
1524 
1525                                         if (a) {
1526                                                 a->clid_len = clid_len;
1527                                                 memcpy(a->clid_data, clid_data, clid_len);
1528                                                 a->iaid = ia->iaid;
1529                                                 a->length = reqlen;
1530                                                 a->peer = *addr;
1531                                                 if (is_na)
1532                                                         a->assigned_host_id = l ? l->hostid : 0;
1533                                                 else
1534                                                         a->assigned_subnet_id = reqhint;
1535                                                 a->valid_until =  now;
1536                                                 a->preferred_until =  now;
1537                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1538                                                 a->iface = iface;
1539                                                 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1540 
1541                                                 if (first)
1542                                                         memcpy(a->key, first->key, sizeof(a->key));
1543                                                 else
1544                                                         odhcpd_urandom(a->key, sizeof(a->key));
1545 
1546                                                 if (is_pd && iface->dhcpv6_pd)
1547                                                         while (!(assigned = assign_pd(iface, a)) &&
1548                                                                !a->managed_size && ++a->length <= 64);
1549                                                 else if (is_na && iface->dhcpv6_na)
1550                                                         assigned = assign_na(iface, a);
1551 
1552                                                 if (l && assigned) {
1553                                                         a->flags |= OAF_STATIC;
1554 
1555                                                         if (l->hostname)
1556                                                                 a->hostname = strdup(l->hostname);
1557 
1558                                                         if (l->leasetime)
1559                                                                 a->leasetime = l->leasetime;
1560 
1561                                                         list_add(&a->lease_list, &l->assignments);
1562                                                         a->lease = l;
1563                                                 }
1564 
1565                                                 if (a->managed_size && !assigned)
1566                                                         return -1;
1567                                         }
1568                                 }
1569                         }
1570 
1571                         if (!assigned || iface->addr6_len == 0)
1572                                 /* Set error status */
1573                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1574                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1575                                 /* Send NOTONLINK status for the IA */
1576                                 status = DHCPV6_STATUS_NOTONLINK;
1577                                 assigned = false;
1578                         } else if (accept_reconf && assigned && !first &&
1579                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1580                                 size_t handshake_len = 4;
1581                                 buf[0] = 0;
1582                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1583                                 buf[2] = 0;
1584                                 buf[3] = 0;
1585 
1586                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1587                                         struct dhcpv6_auth_reconfigure auth = {
1588                                                 htons(DHCPV6_OPT_AUTH),
1589                                                 htons(sizeof(auth) - 4),
1590                                                 3, 1, 0,
1591                                                 {htonl(time(NULL)), htonl(++serial)},
1592                                                 1,
1593                                                 {0}
1594                                         };
1595                                         memcpy(auth.key, a->key, sizeof(a->key));
1596                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1597                                         handshake_len += sizeof(auth);
1598                                 }
1599 
1600 
1601                                 buf += handshake_len;
1602                                 buflen -= handshake_len;
1603                                 response_len += handshake_len;
1604 
1605                                 first = a;
1606                         }
1607 
1608                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1609                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1610 
1611                         /* Was only a solicitation: mark binding for removal */
1612                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1613                                 a->flags &= ~OAF_BOUND;
1614                                 a->flags |= OAF_TENTATIVE;
1615 
1616                                 /* Keep tentative assignment around for 60 seconds */
1617                                 a->valid_until = now + 60;
1618 
1619                         } else if (assigned &&
1620                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1621                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1622                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1623                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1624                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1625                                         if (a->hostname) {
1626                                                 memcpy(a->hostname, hostname, hostname_len);
1627                                                 a->hostname[hostname_len] = 0;
1628 
1629                                                 if (odhcpd_valid_hostname(a->hostname))
1630                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1631                                                 else
1632                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1633                                         }
1634                                 }
1635                                 a->accept_reconf = accept_reconf;
1636                                 a->flags &= ~OAF_TENTATIVE;
1637                                 a->flags |= OAF_BOUND;
1638                                 apply_lease(a, true);
1639                         } else if (!assigned && a && a->managed_size == 0) {
1640                                 /* Cleanup failed assignment */
1641                                 free_assignment(a);
1642                                 a = NULL;
1643                         }
1644                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1645                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1646                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1647                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1648                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1649                                 status = DHCPV6_STATUS_NOBINDING;
1650                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1651                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1652                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1653                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1654                                 if (a) {
1655                                         a->flags |= OAF_BOUND;
1656                                         apply_lease(a, true);
1657                                 }
1658                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1659                                 a->valid_until = now - 1;
1660                         } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1661                                 a->flags &= ~OAF_BOUND;
1662 
1663                                 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
1664                                         memset(a->clid_data, 0, a->clid_len);
1665                                         a->valid_until = now + 3600; /* Block address for 1h */
1666                                 } else
1667                                         a->valid_until = now - 1;
1668                         }
1669                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1670                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1671                                 notonlink = true;
1672                                 break;
1673                         }
1674 
1675                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1676                                 response_len = 0;
1677                                 goto out;
1678                         }
1679                 }
1680 
1681                 buf += ia_response_len;
1682                 buflen -= ia_response_len;
1683                 response_len += ia_response_len;
1684                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1685         }
1686 
1687         switch (hdr->msg_type) {
1688         case DHCPV6_MSG_RELEASE:
1689         case DHCPV6_MSG_DECLINE:
1690         case DHCPV6_MSG_CONFIRM:
1691                 if (response_len + 6 < buflen) {
1692                         buf[0] = 0;
1693                         buf[1] = DHCPV6_OPT_STATUS;
1694                         buf[2] = 0;
1695                         buf[3] = 2;
1696                         buf[4] = 0;
1697                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1698                         response_len += 6;
1699                 }
1700                 break;
1701 
1702         default:
1703                 break;
1704         }
1705 
1706         dhcpv6_ia_write_statefile();
1707 
1708 out:
1709         return response_len;
1710 }
1711 

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