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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 <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->flags & OAF_DHCPV6_PD))
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                 /* Filter Out Prefixes */
235                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
236                         char addrbuf[INET6_ADDRSTRLEN];
237                         syslog(LOG_INFO, "Address %s filtered out on %s",
238                                 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
239                                 iface->name);
240                         continue;
241                 }
242 
243                 addr = addrs[i].addr.in6;
244                 pref = addrs[i].preferred;
245                 valid = addrs[i].valid;
246 
247                 if (c->flags & OAF_DHCPV6_NA) {
248                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
249                                 continue;
250 
251                         addr.s6_addr32[2] = htonl(c->assigned_host_id >> 32);
252                         addr.s6_addr32[3] = htonl(c->assigned_host_id & UINT32_MAX);
253                 } else {
254                         if (!valid_prefix_length(c, addrs[i].prefix))
255                                 continue;
256 
257                         addr.s6_addr32[1] |= htonl(c->assigned_subnet_id);
258                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
259                 }
260 
261                 if (pref > (uint32_t)c->preferred_until)
262                         pref = c->preferred_until;
263 
264                 if (pref > (uint32_t)c->valid_until)
265                         pref = c->valid_until;
266 
267                 if (pref != UINT32_MAX)
268                         pref -= now;
269 
270                 if (valid > (uint32_t)c->valid_until)
271                         valid = c->valid_until;
272 
273                 if (valid != UINT32_MAX)
274                         valid -= now;
275 
276                 func(&addr, prefix, pref, valid, arg);
277         }
278 }
279 
280 struct write_ctxt {
281         FILE *fp;
282         md5_ctx_t md5;
283         struct dhcp_assignment *c;
284         struct interface *iface;
285         char *buf;
286         int buf_len;
287         int buf_idx;
288 };
289 
290 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
291                                 _unused uint32_t valid, void *arg)
292 {
293         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
294         char ipbuf[INET6_ADDRSTRLEN];
295 
296         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
297 
298         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
299             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
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                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
309                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
310         }
311 
312         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
313                                         "%s/%d ", ipbuf, prefix);
314 }
315 
316 void dhcpv6_ia_write_statefile(void)
317 {
318         struct write_ctxt ctxt;
319 
320         md5_begin(&ctxt.md5);
321 
322         if (config.dhcp_statefile) {
323                 unsigned tmp_statefile_strlen = strlen(config.dhcp_statefile) + strlen(".tmp") + 1;
324                 char *tmp_statefile = alloca(tmp_statefile_strlen);
325                 time_t now = odhcpd_time(), wall_time = time(NULL);
326                 int fd, ret;
327                 char leasebuf[512];
328 
329                 snprintf(tmp_statefile, tmp_statefile_strlen, "%s.tmp", config.dhcp_statefile);
330 
331                 fd = open(tmp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
332                 if (fd < 0)
333                         return;
334 
335                 ret = lockf(fd, F_LOCK, 0);
336                 if (ret < 0) {
337                         close(fd);
338                         return;
339                 }
340 
341                 if (ftruncate(fd, 0) < 0) {}
342 
343                 ctxt.fp = fdopen(fd, "w");
344                 if (!ctxt.fp) {
345                         close(fd);
346                         return;
347                 }
348 
349                 ctxt.buf = leasebuf;
350                 ctxt.buf_len = sizeof(leasebuf);
351 
352                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
353                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
354                                         ctxt.iface->dhcpv4 != MODE_SERVER)
355                                 continue;
356 
357                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
358                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
359                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
360                                                 continue;
361 
362                                         char duidbuf[264];
363 
364                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
365 
366                                         /* iface DUID iaid hostname lifetime assigned_host_id length [addrs...] */
367                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" ",
368                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
369                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
370                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
371                                                                 (ctxt.c->valid_until > now ?
372                                                                         (int64_t)(ctxt.c->valid_until - now + wall_time) :
373                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
374 
375                                         if (ctxt.c->flags & OAF_DHCPV6_NA)
376                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
377                                                                          "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
378                                         else
379                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
380                                                                          "%" PRIx32" %u ", ctxt.c->assigned_subnet_id, (unsigned)ctxt.c->length);
381 
382                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
383                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
384                                                                         dhcpv6_write_ia_addr, &ctxt);
385 
386                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
387                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
388                                 }
389                         }
390 
391                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
392                                 struct dhcp_assignment *c;
393 
394                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
395                                         if (!(c->flags & OAF_BOUND))
396                                                 continue;
397 
398                                         char ipbuf[INET6_ADDRSTRLEN];
399                                         char duidbuf[16];
400                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
401 
402                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
403                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
404                                                                 ctxt.iface->ifname, duidbuf,
405                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
406                                                                 (c->hostname ? c->hostname : "-"),
407                                                                 (c->valid_until > now ?
408                                                                         (int64_t)(c->valid_until - now + wall_time) :
409                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
410                                                                 ntohl(c->addr));
411 
412                                         struct in_addr addr = {.s_addr = c->addr};
413                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
414 
415                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
416                                                 fputs(ipbuf, ctxt.fp);
417 
418                                                 char b[256];
419                                                 if (dn_expand(ctxt.iface->search,
420                                                                 ctxt.iface->search + ctxt.iface->search_len,
421                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
422                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
423 
424                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
425                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
426                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
427                                         }
428 
429                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
430                                                                         ctxt.buf_len - ctxt.buf_idx,
431                                                                         "%s/32 ", ipbuf);
432                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
433                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
434                                 }
435                         }
436                 }
437 
438                 fclose(ctxt.fp);
439 
440                 rename(tmp_statefile, config.dhcp_statefile);
441         }
442 
443         uint8_t newmd5[16];
444         md5_end(newmd5, &ctxt.md5);
445 
446         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
447                 memcpy(statemd5, newmd5, sizeof(statemd5));
448                 char *argv[2] = {config.dhcp_cb, NULL};
449                 if (!vfork()) {
450                         execv(argv[0], argv);
451                         _exit(128);
452                 }
453         }
454 }
455 
456 static void __apply_lease(struct dhcp_assignment *a,
457                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
458 {
459         if (a->flags & OAF_DHCPV6_NA)
460                 return;
461 
462         for (ssize_t i = 0; i < addr_len; ++i) {
463                 struct in6_addr prefix;
464 
465                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], a->iface))
466                         continue;
467 
468                 prefix = addrs[i].addr.in6;
469                 prefix.s6_addr32[1] |= htonl(a->assigned_subnet_id);
470                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
471                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
472                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
473         }
474 }
475 
476 static void apply_lease(struct dhcp_assignment *a, bool add)
477 {
478         struct interface *iface = a->iface;
479         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
480         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
481 
482         __apply_lease(a, addrs, addrlen, add);
483 }
484 
485 /* Set border assignment size based on the IPv6 address prefixes */
486 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
487 {
488         time_t now = odhcpd_time();
489         int minprefix = -1;
490 
491         for (size_t i = 0; i < iface->addr6_len; ++i) {
492                 struct odhcpd_ipaddr *addr = &iface->addr6[i];
493 
494                 if (ADDR_MATCH_PIO_FILTER(addr, iface))
495                         continue;
496 
497                 if (addr->preferred > (uint32_t)now &&
498                     addr->prefix < 64 &&
499                     addr->prefix > minprefix)
500                         minprefix = addr->prefix;
501         }
502 
503         if (minprefix > 32 && minprefix <= 64)
504                 b->assigned_subnet_id = 1U << (64 - minprefix);
505         else
506                 b->assigned_subnet_id = 0;
507 }
508 
509 /* More data was received from TCP connection */
510 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
511 {
512         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
513         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
514         time_t now = odhcpd_time();
515         bool first = c->managed_size < 0;
516 
517         for (;;) {
518                 int pending;
519                 char *data = ustream_get_read_buf(s, &pending);
520                 char *end = memmem(data, pending, "\n\n", 2);
521 
522                 if (!end)
523                         break;
524 
525                 end += 2;
526                 end[-1] = 0;
527 
528                 c->managed_size = 0;
529                 if (c->accept_reconf)
530                         c->reconf_cnt = 1;
531 
532                 char *saveptr;
533                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
534                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
535                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
536 
537                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
538                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
539                                 continue;
540 
541                         x = strtok_r(NULL, ",", &saveptr2);
542                         if (sscanf(x, "%hhu", &n->prefix) < 1)
543                                 continue;
544 
545                         x = strtok_r(NULL, ",", &saveptr2);
546                         if (sscanf(x, "%u", &n->preferred) < 1)
547                                 continue;
548 
549                         x = strtok_r(NULL, ",", &saveptr2);
550                         if (sscanf(x, "%u", &n->valid) < 1)
551                                 continue;
552 
553                         if (n->preferred > n->valid)
554                                 continue;
555 
556                         if (UINT32_MAX - now < n->preferred)
557                                 n->preferred = UINT32_MAX;
558                         else
559                                 n->preferred += now;
560 
561                         if (UINT32_MAX - now < n->valid)
562                                 n->valid = UINT32_MAX;
563                         else
564                                 n->valid += now;
565 
566                         n->dprefix = 0;
567 
568                         ++c->managed_size;
569                 }
570 
571                 ustream_consume(s, end - data);
572         }
573 
574         if (first && c->managed_size == 0)
575                 free_assignment(c);
576         else if (first)
577                 c->valid_until = now + 150;
578 }
579 
580 
581 /* TCP transmission has ended, either because of success or timeout or other error */
582 static void managed_handle_pd_done(struct ustream *s)
583 {
584         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
585         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
586 
587         c->valid_until = odhcpd_time() + 15;
588 
589         c->managed_size = 0;
590 
591         if (c->accept_reconf)
592                 c->reconf_cnt = 1;
593 }
594 
595 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
596 {
597         struct dhcp_assignment *c;
598 
599         if (iface->dhcpv6_pd_manager[0]) {
600                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
601                 if (fd >= 0) {
602                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
603                         char iaidbuf[298];
604 
605                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
606 
607                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
608                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
609                         ustream_fd_init(&assign->managed_sock, fd);
610                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
611                                         iaidbuf, assign->iaid, assign->length);
612                         ustream_write_pending(&assign->managed_sock.stream);
613                         assign->managed_size = -1;
614 
615                         assign->valid_until = odhcpd_time() + 15;
616 
617                         list_add(&assign->head, &iface->ia_assignments);
618 
619                         /* Wait initial period of up to 250ms for immediate assignment */
620                         if (poll(&pfd, 1, 250) < 0) {
621                                 syslog(LOG_ERR, "poll(): %m");
622                                 return false;
623                         }
624 
625                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
626 
627                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
628                                 return true;
629                 }
630 
631                 return false;
632         } else if (iface->addr6_len < 1)
633                 return false;
634 
635         /* Try honoring the hint first */
636         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
637         if (assign->assigned_subnet_id) {
638                 list_for_each_entry(c, &iface->ia_assignments, head) {
639                         if (c->flags & OAF_DHCPV6_NA)
640                                 continue;
641 
642                         if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
643                                 list_add_tail(&assign->head, &c->head);
644 
645                                 if (assign->flags & OAF_BOUND)
646                                         apply_lease(assign, true);
647 
648                                 return true;
649                         }
650 
651                         current = (c->assigned_subnet_id + (1 << (64 - c->length)));
652                 }
653         }
654 
655         /* Fallback to a variable assignment */
656         current = 1;
657         list_for_each_entry(c, &iface->ia_assignments, head) {
658                 if (c->flags & OAF_DHCPV6_NA)
659                         continue;
660 
661                 current = (current + asize) & (~asize);
662 
663                 if (current + asize < c->assigned_subnet_id) {
664                         assign->assigned_subnet_id = current;
665                         list_add_tail(&assign->head, &c->head);
666 
667                         if (assign->flags & OAF_BOUND)
668                                 apply_lease(assign, true);
669 
670                         return true;
671                 }
672 
673                 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
674         }
675 
676         return false;
677 }
678 
679 /* Check iid against reserved IPv6 interface identifiers.
680    Refer to:
681      http://www.iana.org/assignments/ipv6-interface-ids */
682 static bool is_reserved_ipv6_iid(uint64_t iid)
683 {
684         if (iid == 0x0000000000000000)
685                 /* Subnet-Router Anycast [RFC4291] */
686                 return true;
687 
688         if ((iid & 0xFFFFFFFFFF000000) == 0x02005EFFFE000000)
689                 /* Reserved IPv6 Interface Identifiers corresponding
690                    to the IANA Ethernet Block [RFC4291] */
691                 return true;
692 
693         if ((iid & 0xFFFFFFFFFFFFFF80) == 0xFDFFFFFFFFFFFF80)
694                 /* Reserved Subnet Anycast Addresses [RFC2526] */
695                 return true;
696 
697         return false;
698 }
699 
700 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
701 {
702         struct dhcp_assignment *c;
703         uint32_t seed = 0;
704 
705         /* Preconfigured assignment by static lease */
706         if (a->assigned_host_id) {
707                 list_for_each_entry(c, &iface->ia_assignments, head) {
708                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
709                                 list_add_tail(&a->head, &c->head);
710                                 return true;
711                         } else if (c->assigned_host_id == a->assigned_host_id)
712                                 return false;
713                 }
714         }
715 
716         /* Seed RNG with checksum of DUID */
717         for (size_t i = 0; i < a->clid_len; ++i)
718                 seed += a->clid_data[i];
719         srandom(seed);
720 
721         /* Try to assign up to 100x */
722         for (size_t i = 0; i < 100; ++i) {
723                 uint64_t try;
724 
725                 if (iface->dhcpv6_hostid_len > 32) {
726                         uint32_t mask_high;
727 
728                         if (iface->dhcpv6_hostid_len >= 64)
729                                 mask_high = UINT32_MAX;
730                         else
731                                 mask_high = (1 << (iface->dhcpv6_hostid_len - 32)) - 1;
732 
733                         do {
734                                 try = (uint32_t)random();
735                                 try |= (uint64_t)((uint32_t)random() & mask_high) << 32;
736                         } while (try < 0x100);
737                 } else {
738                         uint32_t mask_low;
739 
740                         if (iface->dhcpv6_hostid_len == 32)
741                                 mask_low = UINT32_MAX;
742                         else
743                                 mask_low = (1 << iface->dhcpv6_hostid_len) - 1;
744                         do try = ((uint32_t)random()) & mask_low; while (try < 0x100);
745                 }
746 
747                 if (is_reserved_ipv6_iid(try))
748                         continue;
749 
750                 if (config_find_lease_by_hostid(try))
751                         continue;
752 
753                 list_for_each_entry(c, &iface->ia_assignments, head) {
754                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
755                                 a->assigned_host_id = try;
756                                 list_add_tail(&a->head, &c->head);
757                                 return true;
758                         } else if (c->assigned_host_id == try)
759                                 break;
760                 }
761         }
762 
763         return false;
764 }
765 
766 static void handle_addrlist_change(struct netevent_handler_info *info)
767 {
768         struct interface *iface = info->iface;
769         struct dhcp_assignment *c, *d, *border = list_last_entry(
770                         &iface->ia_assignments, struct dhcp_assignment, head);
771         struct list_head reassign = LIST_HEAD_INIT(reassign);
772         time_t now = odhcpd_time();
773 
774         list_for_each_entry(c, &iface->ia_assignments, head) {
775                 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
776                                 && (c->flags & OAF_BOUND))
777                         __apply_lease(c, info->addrs_old.addrs,
778                                         info->addrs_old.len, false);
779         }
780 
781         set_border_assignment_size(iface, border);
782 
783         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
784                 if (c->clid_len == 0 ||
785                     !(c->flags & OAF_DHCPV6_PD) ||
786                     (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
787                     c->managed_size)
788                         continue;
789 
790                 if (c->assigned_subnet_id >= border->assigned_subnet_id)
791                         list_move(&c->head, &reassign);
792                 else if (c->flags & OAF_BOUND)
793                         apply_lease(c, true);
794 
795                 if (c->accept_reconf && c->reconf_cnt == 0) {
796                         struct dhcp_assignment *a;
797 
798                         start_reconf(c);
799 
800                         /* Leave all other assignments of that client alone */
801                         list_for_each_entry(a, &iface->ia_assignments, head)
802                                 if (a != c && a->clid_len == c->clid_len &&
803                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
804                                         a->reconf_cnt = INT_MAX;
805                 }
806         }
807 
808         while (!list_empty(&reassign)) {
809                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
810                 list_del_init(&c->head);
811                 if (!assign_pd(iface, c))
812                         free_assignment(c);
813         }
814 
815         dhcpv6_ia_write_statefile();
816 }
817 
818 static void reconf_timeout_cb(struct uloop_timeout *event)
819 {
820         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
821 
822         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
823                 send_reconf(a);
824                 uloop_timeout_set(&a->reconf_timer,
825                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
826                 a->reconf_cnt++;
827         } else
828                 stop_reconf(a);
829 }
830 
831 static void start_reconf(struct dhcp_assignment *a)
832 {
833         uloop_timeout_set(&a->reconf_timer,
834                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
835         a->reconf_timer.cb = reconf_timeout_cb;
836         a->reconf_cnt++;
837 
838         send_reconf(a);
839 }
840 
841 static void stop_reconf(struct dhcp_assignment *a)
842 {
843         uloop_timeout_cancel(&a->reconf_timer);
844         a->reconf_cnt = 0;
845         a->reconf_timer.cb = NULL;
846 }
847 
848 static void valid_until_cb(struct uloop_timeout *event)
849 {
850         struct interface *iface;
851         time_t now = odhcpd_time();
852 
853         avl_for_each_element(&interfaces, iface, avl) {
854                 struct dhcp_assignment *a, *n;
855 
856                 if (iface->dhcpv6 != MODE_SERVER)
857                         continue;
858 
859                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
860                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
861                                 free_assignment(a);
862                 }
863         }
864         uloop_timeout_set(event, 1000);
865 }
866 
867 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
868                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
869                 struct interface *iface, bool request)
870 {
871         struct dhcpv6_ia_hdr o_ia = {
872                 .type = ia->type,
873                 .len = 0,
874                 .iaid = ia->iaid,
875                 .t1 = 0,
876                 .t2 = 0,
877         };
878         size_t ia_len = sizeof(o_ia);
879         time_t now = odhcpd_time();
880 
881         if (buflen < ia_len)
882                 return 0;
883 
884         if (status) {
885                 struct __attribute__((packed)) {
886                         uint16_t type;
887                         uint16_t len;
888                         uint16_t val;
889                 } o_status = {
890                         .type = htons(DHCPV6_OPT_STATUS),
891                         .len = htons(sizeof(o_status) - 4),
892                         .val = htons(status),
893                 };
894 
895                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
896                 ia_len += sizeof(o_status);
897 
898                 o_ia.len = htons(ia_len - 4);
899                 memcpy(buf, &o_ia, sizeof(o_ia));
900 
901                 return ia_len;
902         }
903 
904         if (a) {
905                 uint32_t leasetime, pref;
906 
907                 if (a->leasetime) {
908                         leasetime = a->leasetime;
909                         pref = a->leasetime;
910                 } else {
911                         leasetime = iface->dhcp_leasetime;
912                         pref = iface->preferred_lifetime;
913                 }
914 
915                 uint32_t valid = leasetime;
916 
917                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
918                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
919                 size_t m = get_preferred_addr(addrs, addrlen);
920 
921                 for (size_t i = 0; i < addrlen; ++i) {
922                         uint32_t prefix_pref, prefix_valid;
923 
924                         if (!valid_addr(&addrs[i], now))
925                                 continue;
926 
927                         /* Filter Out Prefixes */
928                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
929                                 char addrbuf[INET6_ADDRSTRLEN];
930                                 syslog(LOG_INFO, "Address %s filtered out on %s",
931                                         inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
932                                         iface->name);
933                                 continue;
934                         }
935 
936                         prefix_pref = addrs[i].preferred;
937                         prefix_valid = addrs[i].valid;
938 
939                         if (prefix_pref != UINT32_MAX)
940                                 prefix_pref -= now;
941 
942                         if (prefix_pref > pref)
943                                 prefix_pref = pref;
944 
945                         if (prefix_valid != UINT32_MAX)
946                                 prefix_valid -= now;
947 
948                         if (prefix_valid > leasetime)
949                                 prefix_valid = leasetime;
950 
951                         if (prefix_pref > prefix_valid)
952                                 prefix_pref = prefix_valid;
953 
954                         if (a->flags & OAF_DHCPV6_PD) {
955                                 struct dhcpv6_ia_prefix o_ia_p = {
956                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
957                                         .len = htons(sizeof(o_ia_p) - 4),
958                                         .preferred = htonl(prefix_pref),
959                                         .valid = htonl(prefix_valid),
960                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
961                                         .addr = addrs[i].addr.in6,
962                                 };
963 
964                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
965                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
966 
967                                 if (!valid_prefix_length(a, addrs[i].prefix))
968                                         continue;
969 
970                                 if (buflen < ia_len + sizeof(o_ia_p))
971                                         return 0;
972 
973                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
974                                 ia_len += sizeof(o_ia_p);
975                         }
976 
977                         if (a->flags & OAF_DHCPV6_NA) {
978                                 struct dhcpv6_ia_addr o_ia_a = {
979                                         .type = htons(DHCPV6_OPT_IA_ADDR),
980                                         .len = htons(sizeof(o_ia_a) - 4),
981                                         .addr = addrs[i].addr.in6,
982                                         .preferred = htonl(prefix_pref),
983                                         .valid = htonl(prefix_valid)
984                                 };
985 
986                                 o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
987                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
988 
989                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
990                                         continue;
991 
992                                 if (buflen < ia_len + sizeof(o_ia_a))
993                                         return 0;
994 
995                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
996                                 ia_len += sizeof(o_ia_a);
997                         }
998 
999                         /* Calculate T1 / T2 based on non-deprecated addresses */
1000                         if (prefix_pref > 0) {
1001                                 if (prefix_pref < pref)
1002                                         pref = prefix_pref;
1003 
1004                                 if (prefix_valid < valid)
1005                                         valid = prefix_valid;
1006                         }
1007                 }
1008 
1009                 if (!INFINITE_VALID(a->valid_until))
1010                         /* UINT32_MAX is considered as infinite leasetime */
1011                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
1012 
1013                 if (!INFINITE_VALID(a->preferred_until))
1014                         /* UINT32_MAX is considered as infinite leasetime */
1015                         a->preferred_until = (pref == UINT32_MAX) ? 0 : pref + now;
1016 
1017                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
1018                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
1019 
1020                 if (!o_ia.t1)
1021                         o_ia.t1 = htonl(1);
1022 
1023                 if (!o_ia.t2)
1024                         o_ia.t2 = htonl(1);
1025         }
1026 
1027         if (!request) {
1028                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1029                 uint16_t otype, olen;
1030 
1031                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1032                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
1033                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
1034                         bool found = false;
1035 
1036                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
1037                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
1038                                 continue;
1039 
1040                         if (a) {
1041                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1042                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1043 
1044                                 for (size_t i = 0; i < addrlen; ++i) {
1045                                         struct in6_addr addr;
1046 
1047                                         if (!valid_addr(&addrs[i], now))
1048                                                 continue;
1049 
1050                                         if (!valid_prefix_length(a, addrs[i].prefix))
1051                                                 continue;
1052 
1053                                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1054                                                 continue;
1055 
1056                                         addr = addrs[i].addr.in6;
1057                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1058                                                 addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1059                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1060 
1061                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
1062                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
1063                                                         found = true;
1064                                         } else {
1065                                                 addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1066                                                 addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1067 
1068                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
1069                                                         found = true;
1070                                         }
1071                                 }
1072                         }
1073 
1074                         if (!found) {
1075                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1076                                         struct dhcpv6_ia_prefix o_ia_p = {
1077                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
1078                                                 .len = htons(sizeof(o_ia_p) - 4),
1079                                                 .preferred = 0,
1080                                                 .valid = 0,
1081                                                 .prefix = ia_p->prefix,
1082                                                 .addr = ia_p->addr,
1083                                         };
1084 
1085                                         if (buflen < ia_len + sizeof(o_ia_p))
1086                                                 return 0;
1087 
1088                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1089                                         ia_len += sizeof(o_ia_p);
1090                                 } else {
1091                                         struct dhcpv6_ia_addr o_ia_a = {
1092                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
1093                                                 .len = htons(sizeof(o_ia_a) - 4),
1094                                                 .addr = ia_a->addr,
1095                                                 .preferred = 0,
1096                                                 .valid = 0,
1097                                         };
1098 
1099                                         if (buflen < ia_len + sizeof(o_ia_a))
1100                                                 continue;
1101 
1102                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1103                                         ia_len += sizeof(o_ia_a);
1104                                 }
1105                         }
1106                 }
1107         }
1108 
1109         o_ia.len = htons(ia_len - 4);
1110         memcpy(buf, &o_ia, sizeof(o_ia));
1111         return ia_len;
1112 }
1113 
1114 struct log_ctxt {
1115         char *buf;
1116         int buf_len;
1117         int buf_idx;
1118 };
1119 
1120 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1121                                 _unused uint32_t valid, void *arg)
1122 {
1123         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1124         char addrbuf[INET6_ADDRSTRLEN];
1125 
1126         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1127         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1128                                         "%s/%d ", addrbuf, prefix);
1129 }
1130 
1131 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1132                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1133 {
1134         const char *type = "UNKNOWN";
1135         const char *status = "UNKNOWN";
1136 
1137         switch (msgtype) {
1138         case DHCPV6_MSG_SOLICIT:
1139                 type = "SOLICIT";
1140                 break;
1141         case DHCPV6_MSG_REQUEST:
1142                 type = "REQUEST";
1143                 break;
1144         case DHCPV6_MSG_CONFIRM:
1145                 type = "CONFIRM";
1146                 break;
1147         case DHCPV6_MSG_RENEW:
1148                 type = "RENEW";
1149                 break;
1150         case DHCPV6_MSG_REBIND:
1151                 type = "REBIND";
1152                 break;
1153         case DHCPV6_MSG_RELEASE:
1154                 type = "RELEASE";
1155                 break;
1156         case DHCPV6_MSG_DECLINE:
1157                 type = "DECLINE";
1158                 break;
1159         }
1160 
1161         switch (code) {
1162         case DHCPV6_STATUS_OK:
1163                 status = "ok";
1164                 break;
1165         case DHCPV6_STATUS_NOADDRSAVAIL:
1166                 status = "no addresses available";
1167                 break;
1168         case DHCPV6_STATUS_NOBINDING:
1169                 status = "no binding";
1170                 break;
1171         case DHCPV6_STATUS_NOTONLINK:
1172                 status = "not on-link";
1173                 break;
1174         case DHCPV6_STATUS_NOPREFIXAVAIL:
1175                 status = "no prefix available";
1176                 break;
1177         }
1178 
1179         char leasebuf[256] = "";
1180 
1181         if (a) {
1182                 struct log_ctxt ctxt = {.buf = leasebuf,
1183                                         .buf_len = sizeof(leasebuf),
1184                                         .buf_idx = 0 };
1185 
1186                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1187         }
1188 
1189         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1190                          duidbuf, iface->name, status, leasebuf);
1191 }
1192 
1193 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1194                 struct interface *iface)
1195 {
1196         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1197         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1198         time_t now = odhcpd_time();
1199         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1200         uint16_t otype, olen;
1201         bool onlink = true;
1202 
1203         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1204                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1205                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1206 
1207                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1208                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1209                         continue;
1210 
1211                 onlink = false;
1212                 for (size_t i = 0; i < addrlen; ++i) {
1213                         if (!valid_addr(&addrs[i], now))
1214                                 continue;
1215 
1216                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1217                                 continue;
1218 
1219                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1220                                 if (p->prefix < addrs[i].prefix ||
1221                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1222                                         continue;
1223 
1224                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1225                                 continue;
1226 
1227                         onlink = true;
1228                 }
1229 
1230                 if (!onlink)
1231                         break;
1232         }
1233 
1234         return onlink;
1235 }
1236 
1237 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1238                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1239 {
1240         struct lease *l;
1241         struct dhcp_assignment *first = NULL;
1242         const struct dhcpv6_client_header *hdr = data;
1243         time_t now = odhcpd_time();
1244         uint16_t otype, olen, clid_len = 0;
1245         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1246         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1247         size_t hostname_len = 0, response_len = 0;
1248         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1249         char duidbuf[261], hostname[256];
1250 
1251         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1252                 if (otype == DHCPV6_OPT_CLIENTID) {
1253                         clid_data = odata;
1254                         clid_len = olen;
1255 
1256                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1257                                 memcpy(mac, &odata[8], sizeof(mac));
1258                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1259                                 memcpy(mac, &odata[4], sizeof(mac));
1260 
1261                         if (olen <= 130)
1262                                 odhcpd_hexlify(duidbuf, odata, olen);
1263                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1264                         uint8_t fqdn_buf[256];
1265                         memcpy(fqdn_buf, odata, olen);
1266                         fqdn_buf[olen++] = 0;
1267 
1268                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1269                                 hostname_len = strcspn(hostname, ".");
1270                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1271                         accept_reconf = true;
1272                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1273                         rapid_commit = true;
1274         }
1275 
1276         if (!clid_data || !clid_len || clid_len > 130)
1277                 goto out;
1278 
1279         l = config_find_lease_by_duid(clid_data, clid_len);
1280         if (!l)
1281                 l = config_find_lease_by_mac(mac);
1282 
1283         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1284                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1285                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1286                 bool ia_addr_present = false;
1287                 if (!is_pd && !is_na)
1288                         continue;
1289 
1290                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1291                 size_t ia_response_len = 0;
1292                 uint8_t reqlen = (is_pd) ? 62 : 128;
1293                 uint32_t reqhint = 0;
1294 
1295                 /* Parse request hint for IA-PD */
1296                 if (is_pd) {
1297                         uint8_t *sdata;
1298                         uint16_t stype, slen;
1299                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1300                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1301                                         continue;
1302 
1303                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1304                                 if (p->prefix) {
1305                                         reqlen = p->prefix;
1306                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1307                                         if (reqlen > 32 && reqlen <= 64)
1308                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1309                                 }
1310                         }
1311 
1312                         if (reqlen > 64)
1313                                 reqlen = 64;
1314                 } else if (is_na) {
1315                         uint8_t *sdata;
1316                         uint16_t stype, slen;
1317                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1318                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1319                                         continue;
1320 
1321                                 ia_addr_present = true;
1322                         }
1323                 }
1324 
1325                 /* Find assignment */
1326                 struct dhcp_assignment *c, *a = NULL;
1327                 list_for_each_entry(c, &iface->ia_assignments, head) {
1328                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1329                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1330                             ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1331                                 a = c;
1332 
1333                                 /* Reset state */
1334                                 if (a->flags & OAF_BOUND)
1335                                         apply_lease(a, false);
1336 
1337                                 stop_reconf(a);
1338                                 break;
1339                         }
1340                 }
1341 
1342                 if (l && a && a->lease != l) {
1343                         free_assignment(a);
1344                         a = NULL;
1345                 }
1346 
1347                 /* Generic message handling */
1348                 uint16_t status = DHCPV6_STATUS_OK;
1349                 if (a && a->managed_size < 0)
1350                         return -1;
1351 
1352                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1353                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1354                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1355                         bool assigned = !!a;
1356 
1357                         if (!a) {
1358                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1359                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1360                                         /* Create new binding */
1361                                         a = alloc_assignment(clid_len);
1362 
1363                                         if (a) {
1364                                                 a->clid_len = clid_len;
1365                                                 memcpy(a->clid_data, clid_data, clid_len);
1366                                                 a->iaid = ia->iaid;
1367                                                 a->length = reqlen;
1368                                                 a->peer = *addr;
1369                                                 if (is_na)
1370                                                         a->assigned_host_id = l ? l->hostid : 0;
1371                                                 else
1372                                                         a->assigned_subnet_id = reqhint;
1373                                                 a->valid_until =  now;
1374                                                 a->preferred_until =  now;
1375                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1376                                                 a->iface = iface;
1377                                                 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1378 
1379                                                 if (first)
1380                                                         memcpy(a->key, first->key, sizeof(a->key));
1381                                                 else
1382                                                         odhcpd_urandom(a->key, sizeof(a->key));
1383 
1384                                                 if (is_pd && iface->dhcpv6_pd)
1385                                                         while (!(assigned = assign_pd(iface, a)) &&
1386                                                                !a->managed_size && ++a->length <= 64);
1387                                                 else if (is_na && iface->dhcpv6_na)
1388                                                         assigned = assign_na(iface, a);
1389 
1390                                                 if (l && assigned) {
1391                                                         a->flags |= OAF_STATIC;
1392 
1393                                                         if (l->hostname)
1394                                                                 a->hostname = strdup(l->hostname);
1395 
1396                                                         if (l->leasetime)
1397                                                                 a->leasetime = l->leasetime;
1398 
1399                                                         list_add(&a->lease_list, &l->assignments);
1400                                                         a->lease = l;
1401                                                 }
1402 
1403                                                 if (a->managed_size && !assigned)
1404                                                         return -1;
1405                                         }
1406                                 }
1407                         }
1408 
1409                         if (!assigned || iface->addr6_len == 0)
1410                                 /* Set error status */
1411                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1412                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1413                                 /* Send NOTONLINK staus for the IA */
1414                                 status = DHCPV6_STATUS_NOTONLINK;
1415                                 assigned = false;
1416                         } else if (accept_reconf && assigned && !first &&
1417                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1418                                 size_t handshake_len = 4;
1419                                 buf[0] = 0;
1420                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1421                                 buf[2] = 0;
1422                                 buf[3] = 0;
1423 
1424                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1425                                         struct dhcpv6_auth_reconfigure auth = {
1426                                                 htons(DHCPV6_OPT_AUTH),
1427                                                 htons(sizeof(auth) - 4),
1428                                                 3, 1, 0,
1429                                                 {htonl(time(NULL)), htonl(++serial)},
1430                                                 1,
1431                                                 {0}
1432                                         };
1433                                         memcpy(auth.key, a->key, sizeof(a->key));
1434                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1435                                         handshake_len += sizeof(auth);
1436                                 }
1437 
1438 
1439                                 buf += handshake_len;
1440                                 buflen -= handshake_len;
1441                                 response_len += handshake_len;
1442 
1443                                 first = a;
1444                         }
1445 
1446                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1447                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1448 
1449                         /* Was only a solicitation: mark binding for removal */
1450                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1451                                 a->flags &= ~OAF_BOUND;
1452                                 a->flags |= OAF_TENTATIVE;
1453 
1454                                 /* Keep tentative assignment around for 60 seconds */
1455                                 a->valid_until = now + 60;
1456 
1457                         } else if (assigned &&
1458                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1459                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1460                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1461                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1462                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1463                                         if (a->hostname) {
1464                                                 memcpy(a->hostname, hostname, hostname_len);
1465                                                 a->hostname[hostname_len] = 0;
1466 
1467                                                 if (odhcpd_valid_hostname(a->hostname))
1468                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1469                                                 else
1470                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1471                                         }
1472                                 }
1473                                 a->accept_reconf = accept_reconf;
1474                                 a->flags &= ~OAF_TENTATIVE;
1475                                 a->flags |= OAF_BOUND;
1476                                 apply_lease(a, true);
1477                         } else if (!assigned && a && a->managed_size == 0) {
1478                                 /* Cleanup failed assignment */
1479                                 free_assignment(a);
1480                                 a = NULL;
1481                         }
1482                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1483                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1484                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1485                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1486                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1487                                 status = DHCPV6_STATUS_NOBINDING;
1488                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1489                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1490                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1491                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1492                                 if (a) {
1493                                         a->flags |= OAF_BOUND;
1494                                         apply_lease(a, true);
1495                                 }
1496                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1497                                 a->valid_until = now - 1;
1498                         } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1499                                 a->flags &= ~OAF_BOUND;
1500 
1501                                 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
1502                                         memset(a->clid_data, 0, a->clid_len);
1503                                         a->valid_until = now + 3600; /* Block address for 1h */
1504                                 } else
1505                                         a->valid_until = now - 1;
1506                         }
1507                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1508                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1509                                 notonlink = true;
1510                                 break;
1511                         }
1512 
1513                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1514                                 response_len = 0;
1515                                 goto out;
1516                         }
1517                 }
1518 
1519                 buf += ia_response_len;
1520                 buflen -= ia_response_len;
1521                 response_len += ia_response_len;
1522                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1523         }
1524 
1525         switch (hdr->msg_type) {
1526         case DHCPV6_MSG_RELEASE:
1527         case DHCPV6_MSG_DECLINE:
1528         case DHCPV6_MSG_CONFIRM:
1529                 if (response_len + 6 < buflen) {
1530                         buf[0] = 0;
1531                         buf[1] = DHCPV6_OPT_STATUS;
1532                         buf[2] = 0;
1533                         buf[3] = 2;
1534                         buf[4] = 0;
1535                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1536                         response_len += 6;
1537                 }
1538                 break;
1539 
1540         default:
1541                 break;
1542         }
1543 
1544         dhcpv6_ia_write_statefile();
1545 
1546 out:
1547         return response_len;
1548 }
1549 

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