dhcpv4: remove comment code lines
[project/odhcpd.git] / src / dhcpv6-ia.c
1 /**
2  * Copyright (C) 2013 Steven Barth <steven@midlink.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License v2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14
15 #include "odhcpd.h"
16 #include "dhcpv6.h"
17 #include "dhcpv4.h"
18 #include "libubox/md5.h"
19 #include "libubox/usock.h"
20
21 #include <time.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <poll.h>
26 #include <alloca.h>
27 #include <resolv.h>
28 #include <limits.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 #include <stdbool.h>
33 #include <arpa/inet.h>
34 #include <sys/timerfd.h>
35
36
37 static void update(struct interface *iface);
38 static void reconf_timer(struct uloop_timeout *event);
39 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
40 static uint32_t serial = 0;
41 static uint8_t statemd5[16];
42
43
44 int dhcpv6_ia_init(void)
45 {
46         uloop_timeout_set(&reconf_event, 2000);
47         return 0;
48 }
49
50
51 void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
52 {
53         if (c->managed_sock.fd.registered) {
54                 ustream_free(&c->managed_sock.stream);
55                 close(c->managed_sock.fd.fd);
56         }
57
58         if (c->head.next)
59                 list_del(&c->head);
60
61         free(c->managed);
62         free(c->hostname);
63         free(c);
64 }
65
66
67 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
68 {
69         if (!enable && iface->ia_assignments.next) {
70                 struct dhcpv6_assignment *c;
71                 while (!list_empty(&iface->ia_assignments)) {
72                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
73                         free_dhcpv6_assignment(c);
74                 }
75         }
76
77         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
78                 if (!iface->ia_assignments.next)
79                         INIT_LIST_HEAD(&iface->ia_assignments);
80
81                 if (list_empty(&iface->ia_assignments)) {
82                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
83                         if (!border) {
84                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
85                                 return -1;
86                         }
87                         
88                         border->length = 64;
89                         list_add(&border->head, &iface->ia_assignments);
90                 }
91
92                 update(iface);
93
94                 // Parse static entries
95                 struct lease *lease;
96                 list_for_each_entry(lease, &leases, head) {
97                         // Construct entry
98                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
99                         if (!a) {
100                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
101                                         iface->ifname);
102                                 return -1;
103                         }
104
105                         a->clid_len = lease->duid_len;
106                         a->length = 128;
107                         if (lease->hostid) {
108                                 a->assigned = lease->hostid;
109                         } else {
110                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
111                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
112                         }
113                         odhcpd_urandom(a->key, sizeof(a->key));
114                         memcpy(a->clid_data, lease->duid, a->clid_len);
115                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
116
117                         // Assign to all interfaces
118                         struct dhcpv6_assignment *c;
119                         list_for_each_entry(c, &iface->ia_assignments, head) {
120                                 if (c->length != 128 || c->assigned > a->assigned) {
121                                         list_add_tail(&a->head, &c->head);
122                                         break;
123                                 } else if (c->assigned == a->assigned) {
124                                         // Already an assignment with that number
125                                         break;
126                                 }
127                         }
128
129                         if (a->head.next) {
130                                 if (lease->hostname[0]) {
131                                         free(a->hostname);
132                                         a->hostname = strdup(lease->hostname);
133                                 }
134                         } else {
135                                 free(a->hostname);
136                                 free(a);
137                         }
138                 }
139         }
140         return 0;
141 }
142
143
144 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
145 {
146         struct {
147                 struct dhcpv6_client_header hdr;
148                 uint16_t srvid_type;
149                 uint16_t srvid_len;
150                 uint16_t duid_type;
151                 uint16_t hardware_type;
152                 uint8_t mac[6];
153                 uint16_t msg_type;
154                 uint16_t msg_len;
155                 uint8_t msg_id;
156                 struct dhcpv6_auth_reconfigure auth;
157                 uint16_t clid_type;
158                 uint16_t clid_len;
159                 uint8_t clid_data[128];
160         } __attribute__((packed)) reconf_msg = {
161                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
162                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
163                 .srvid_len = htons(10),
164                 .duid_type = htons(3),
165                 .hardware_type = htons(1),
166                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
167                 .msg_len = htons(1),
168                 .msg_id = DHCPV6_MSG_RENEW,
169                 .auth = {htons(DHCPV6_OPT_AUTH),
170                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
171                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
172                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
173                 .clid_len = htons(assign->clid_len),
174                 .clid_data = {0},
175         };
176
177         odhcpd_get_mac(iface, reconf_msg.mac);
178         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
179         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
180
181         md5_ctx_t md5;
182         uint8_t secretbytes[64];
183         memset(secretbytes, 0, sizeof(secretbytes));
184         memcpy(secretbytes, assign->key, sizeof(assign->key));
185
186         for (size_t i = 0; i < sizeof(secretbytes); ++i)
187                 secretbytes[i] ^= 0x36;
188
189         md5_begin(&md5);
190         md5_hash(secretbytes, sizeof(secretbytes), &md5);
191         md5_hash(iov.iov_base, iov.iov_len, &md5);
192         md5_end(reconf_msg.auth.key, &md5);
193
194         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
195                 secretbytes[i] ^= 0x36;
196                 secretbytes[i] ^= 0x5c;
197         }
198
199         md5_begin(&md5);
200         md5_hash(secretbytes, sizeof(secretbytes), &md5);
201         md5_hash(reconf_msg.auth.key, 16, &md5);
202         md5_end(reconf_msg.auth.key, &md5);
203
204         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
205 }
206
207
208 void dhcpv6_write_statefile(void)
209 {
210         md5_ctx_t md5;
211         md5_begin(&md5);
212
213         if (config.dhcp_statefile) {
214                 time_t now = odhcpd_time(), wall_time = time(NULL);
215                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
216                 if (fd < 0)
217                         return;
218
219                 lockf(fd, F_LOCK, 0);
220                 if (ftruncate(fd, 0) < 0) {}
221
222                 FILE *fp = fdopen(fd, "w");
223                 if (!fp) {
224                         close(fd);
225                         return;
226                 }
227
228                 struct interface *iface;
229                 list_for_each_entry(iface, &interfaces, head) {
230                         if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
231                                 continue;
232
233                         if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
234                                 struct dhcpv6_assignment *c;
235                                 list_for_each_entry(c, &iface->ia_assignments, head) {
236                                         if (c->clid_len == 0 || c->managed_size < 0)
237                                                 continue;
238
239                                         char ipbuf[INET6_ADDRSTRLEN];
240                                         char leasebuf[512];
241                                         char duidbuf[264];
242                                         odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
243
244                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
245                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
246                                                         iface->ifname, duidbuf, ntohl(c->iaid),
247                                                         (c->hostname ? c->hostname : "-"),
248                                                         (unsigned)(c->valid_until > now ?
249                                                                         (c->valid_until - now + wall_time) : 0),
250                                                         c->assigned, (unsigned)c->length);
251
252                                         struct in6_addr addr;
253                                         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
254                                         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
255                                         size_t m = 0;
256
257                                         for (size_t i = 0; i < addrlen; ++i)
258                                                 if (addrs[i].preferred > addrs[m].preferred ||
259                                                                 (addrs[i].preferred == addrs[m].preferred &&
260                                                                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
261                                                         m = i;
262
263                                         for (size_t i = 0; i < addrlen; ++i) {
264                                                 if (addrs[i].prefix > 96 || c->valid_until <= now ||
265                                                                 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
266                                                                                 addrs[i].prefix == 64))
267                                                         continue;
268
269                                                 addr = addrs[i].addr;
270                                                 if (c->length == 128)
271                                                         addr.s6_addr32[3] = htonl(c->assigned);
272                                                 else
273                                                         addr.s6_addr32[1] |= htonl(c->assigned);
274
275                                                 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
276
277                                                 if (c->length == 128 && c->hostname) {
278                                                         fputs(ipbuf, fp);
279
280                                                         char b[256];
281                                                         if (dn_expand(iface->search, iface->search + iface->search_len,
282                                                                         iface->search, b, sizeof(b)) > 0)
283                                                                 fprintf(fp, "\t%s.%s", c->hostname, b);
284
285                                                         fprintf(fp, "\t%s\n", c->hostname);
286                                                         md5_hash(ipbuf, strlen(ipbuf), &md5);
287                                                         md5_hash(c->hostname, strlen(c->hostname), &md5);
288                                                 }
289
290                                                 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
291                                                                 (c->managed_size) ? addrs[i].prefix : c->length);
292                                         }
293                                         leasebuf[l - 1] = '\n';
294                                         fwrite(leasebuf, 1, l, fp);
295                                 }
296                         }
297
298                         if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
299                                 struct dhcpv4_assignment *c;
300                                 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
301                                         char ipbuf[INET6_ADDRSTRLEN];
302                                         char leasebuf[512];
303                                         char duidbuf[16];
304                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
305
306                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
307                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
308                                                         iface->ifname, duidbuf,
309                                                         (c->hostname ? c->hostname : "-"),
310                                                         (unsigned)(c->valid_until > now ?
311                                                                         (c->valid_until - now + wall_time) : 0),
312                                                         c->addr);
313
314                                         struct in_addr addr = {htonl(c->addr)};
315                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
316
317                                         if (c->hostname[0]) {
318                                                 fputs(ipbuf, fp);
319
320                                                 char b[256];
321                                                 if (dn_expand(iface->search, iface->search + iface->search_len,
322                                                                 iface->search, b, sizeof(b)) > 0)
323                                                         fprintf(fp, "\t%s.%s", c->hostname, b);
324
325                                                 fprintf(fp, "\t%s\n", c->hostname);
326                                                 md5_hash(ipbuf, strlen(ipbuf), &md5);
327                                                 md5_hash(c->hostname, strlen(c->hostname), &md5);
328                                         }
329
330                                         l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
331                                         leasebuf[l - 1] = '\n';
332                                         fwrite(leasebuf, 1, l, fp);
333                                 }
334                         }
335                 }
336
337                 fclose(fp);
338         }
339
340         uint8_t newmd5[16];
341         md5_end(newmd5, &md5);
342
343         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
344                 memcpy(statemd5, newmd5, sizeof(statemd5));
345                 char *argv[2] = {config.dhcp_cb, NULL};
346                 if (!vfork()) {
347                         execv(argv[0], argv);
348                         _exit(128);
349                 }
350         }
351 }
352
353
354 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
355 {
356         if (a->length > 64 || a->managed_size < 0)
357                 return;
358
359         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
360         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
361
362         for (size_t i = 0; i < addrlen; ++i) {
363                 struct in6_addr prefix = addrs[i].addr;
364                 prefix.s6_addr32[1] |= htonl(a->assigned);
365                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
366                                 iface, &a->peer.sin6_addr, add);
367         }
368 }
369
370
371 // More data was received from TCP connection
372 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
373 {
374         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
375         time_t now = odhcpd_time();
376         bool first = c->managed_size < 0;
377
378         for (;;) {
379                 int pending;
380                 char *data = ustream_get_read_buf(s, &pending);
381                 char *end = memmem(data, pending, "\n\n", 2);
382
383                 if (!end)
384                         break;
385
386                 end += 2;
387                 end[-1] = 0;
388
389                 c->managed_size = 0;
390                 if (c->accept_reconf)
391                         c->reconf_cnt = 1;
392
393                 char *saveptr;
394                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
395                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
396                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
397
398                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
399                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
400                                 continue;
401
402                         x = strtok_r(NULL, ",", &saveptr2);
403                         if (sscanf(x, "%hhu", &n->prefix) < 1)
404                                 continue;
405
406                         x = strtok_r(NULL, ",", &saveptr2);
407                         if (sscanf(x, "%u", &n->preferred) < 1)
408                                 continue;
409
410                         x = strtok_r(NULL, ",", &saveptr2);
411                         if (sscanf(x, "%u", &n->valid) < 1)
412                                 continue;
413
414                         if (n->preferred > n->valid)
415                                 continue;
416
417                         if (UINT32_MAX - now < n->preferred)
418                                 n->preferred = UINT32_MAX;
419                         else
420                                 n->preferred += now;
421
422                         if (UINT32_MAX - now < n->valid)
423                                 n->valid = UINT32_MAX;
424                         else
425                                 n->valid += now;
426
427                         n->dprefix = 0;
428
429                         ++c->managed_size;
430                 }
431
432                 ustream_consume(s, end - data);
433         }
434
435         if (first && c->managed_size == 0)
436                 free_dhcpv6_assignment(c);
437         else if (first)
438                 c->valid_until = now + 150;
439 }
440
441
442 // TCP transmission has ended, either because of success or timeout or other error
443 static void managed_handle_pd_done(struct ustream *s)
444 {
445         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
446         c->valid_until = odhcpd_time() + 15;
447         c->managed_size = 0;
448         if (c->accept_reconf)
449                 c->reconf_cnt = 1;
450 }
451
452
453
454 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
455 {
456         struct dhcpv6_assignment *c;
457
458         if (iface->dhcpv6_pd_manager[0]) {
459                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
460                 if (fd >= 0) {
461                         char iaidbuf[298];
462                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
463
464                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
465                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
466                         ustream_fd_init(&assign->managed_sock, fd);
467                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
468                                         iaidbuf, assign->iaid, assign->length);
469                         ustream_write_pending(&assign->managed_sock.stream);
470                         assign->managed_size = -1;
471                         assign->valid_until = odhcpd_time() + 15;
472                         list_add(&assign->head, &iface->ia_assignments);
473
474                         // Wait initial period of up to 250ms for immediate assignment
475                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
476                         poll(&pfd, 1, 250);
477                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
478
479                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
480                                 return true;
481                 }
482
483                 return false;
484         } else if (iface->ia_addr_len < 1) {
485                 return false;
486         }
487
488         // Try honoring the hint first
489         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
490         if (assign->assigned) {
491                 list_for_each_entry(c, &iface->ia_assignments, head) {
492                         if (c->length == 128 || c->length == 0)
493                                 continue;
494
495                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
496                                 list_add_tail(&assign->head, &c->head);
497                                 apply_lease(iface, assign, true);
498                                 return true;
499                         }
500
501                         if (c->assigned != 0)
502                                 current = (c->assigned + (1 << (64 - c->length)));
503                 }
504         }
505
506         // Fallback to a variable assignment
507         current = 1;
508         list_for_each_entry(c, &iface->ia_assignments, head) {
509                 if (c->length == 128 || c->length == 0)
510                         continue;
511
512                 current = (current + asize) & (~asize);
513                 if (current + asize < c->assigned) {
514                         assign->assigned = current;
515                         list_add_tail(&assign->head, &c->head);
516                         apply_lease(iface, assign, true);
517                         return true;
518                 }
519
520                 if (c->assigned != 0)
521                         current = (c->assigned + (1 << (64 - c->length)));
522         }
523
524         return false;
525 }
526
527
528 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
529 {
530         // Seed RNG with checksum of DUID
531         uint32_t seed = 0;
532         for (size_t i = 0; i < assign->clid_len; ++i)
533                 seed += assign->clid_data[i];
534         srand(seed);
535
536         // Try to assign up to 100x
537         for (size_t i = 0; i < 100; ++i) {
538                 uint32_t try;
539                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
540
541                 struct dhcpv6_assignment *c;
542                 list_for_each_entry(c, &iface->ia_assignments, head) {
543                         if (c->length == 0)
544                                 continue;
545
546                         if (c->assigned > try || c->length != 128) {
547                                 assign->assigned = try;
548                                 list_add_tail(&assign->head, &c->head);
549                                 return true;
550                         } else if (c->assigned == try) {
551                                 break;
552                         }
553                 }
554         }
555
556         return false;
557 }
558
559
560 static int prefixcmp(const void *va, const void *vb)
561 {
562         const struct odhcpd_ipaddr *a = va, *b = vb;
563         uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
564         uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
565         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
566 }
567
568
569 static void update(struct interface *iface)
570 {
571         struct odhcpd_ipaddr addr[8];
572         memset(addr, 0, sizeof(addr));
573         int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
574
575         if (len < 0)
576                 return;
577
578         qsort(addr, len, sizeof(*addr), prefixcmp);
579
580         time_t now = odhcpd_time();
581         int minprefix = -1;
582
583         for (int i = 0; i < len; ++i) {
584                 if (addr[i].preferred > 0 && addr[i].prefix < 64 &&
585                                 addr[i].prefix > minprefix)
586                         minprefix = addr[i].prefix;
587
588                 addr[i].addr.s6_addr32[3] = 0;
589
590                 if (addr[i].preferred < UINT32_MAX - now)
591                         addr[i].preferred += now;
592
593                 if (addr[i].valid < UINT32_MAX - now)
594                         addr[i].valid += now;
595         }
596
597         struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
598         if (minprefix > 32 && minprefix <= 64)
599                 border->assigned = 1U << (64 - minprefix);
600         else
601                 border->assigned = 0;
602
603         bool change = len != (int)iface->ia_addr_len;
604         for (int i = 0; !change && i < len; ++i)
605                 if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
606                                 addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
607                                 (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
608                                 (addr[i].valid > (uint32_t)now + 7200) !=
609                                                 (iface->ia_addr[i].valid > (uint32_t)now + 7200))
610                         change = true;
611
612         if (change) {
613                 struct dhcpv6_assignment *c;
614                 list_for_each_entry(c, &iface->ia_assignments, head)
615                         if (c != border && !iface->managed)
616                                 apply_lease(iface, c, false);
617         }
618
619         memcpy(iface->ia_addr, addr, len * sizeof(*addr));
620         iface->ia_addr_len = len;
621
622         if (change) { // Addresses / prefixes have changed
623                 struct list_head reassign = LIST_HEAD_INIT(reassign);
624                 struct dhcpv6_assignment *c, *d;
625                 list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
626                         if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
627                                 continue;
628
629                         if (c->length < 128 && c->assigned >= border->assigned && c != border)
630                                 list_move(&c->head, &reassign);
631                         else if (c != border)
632                                 apply_lease(iface, c, true);
633
634                         if (c->accept_reconf && c->reconf_cnt == 0) {
635                                 c->reconf_cnt = 1;
636                                 c->reconf_sent = now;
637                                 send_reconf(iface, c);
638
639                                 // Leave all other assignments of that client alone
640                                 struct dhcpv6_assignment *a;
641                                 list_for_each_entry(a, &iface->ia_assignments, head)
642                                         if (a != c && a->clid_len == c->clid_len &&
643                                                         !memcmp(a->clid_data, c->clid_data, a->clid_len))
644                                                 c->reconf_cnt = INT_MAX;
645                         }
646                 }
647
648                 while (!list_empty(&reassign)) {
649                         c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
650                         list_del(&c->head);
651                         if (!assign_pd(iface, c)) {
652                                 c->assigned = 0;
653                                 list_add(&c->head, &iface->ia_assignments);
654                         }
655                 }
656
657                 dhcpv6_write_statefile();
658         }
659 }
660
661
662 static void reconf_timer(struct uloop_timeout *event)
663 {
664         time_t now = odhcpd_time();
665         struct interface *iface;
666         list_for_each_entry(iface, &interfaces, head) {
667                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
668                         continue;
669
670                 struct dhcpv6_assignment *a, *n;
671                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
672                         if (a->valid_until < now) {
673                                 if ((a->length < 128 && a->clid_len > 0) ||
674                                                 (a->length == 128 && a->clid_len == 0)) {
675                                         list_del(&a->head);
676                                         free_dhcpv6_assignment(a);
677                                 }
678                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
679                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
680                                 ++a->reconf_cnt;
681                                 a->reconf_sent = now;
682                                 send_reconf(iface, a);
683                         }
684                 }
685         }
686         uloop_timeout_set(event, 2000);
687 }
688
689
690 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
691                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
692                 struct interface *iface, bool request)
693 {
694         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
695                 return 0;
696
697         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
698         size_t datalen = sizeof(out);
699         time_t now = odhcpd_time();
700
701         if (status) {
702                 struct __attribute__((packed)) {
703                         uint16_t type;
704                         uint16_t len;
705                         uint16_t value;
706                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
707                                 htons(status)};
708
709                 memcpy(buf + datalen, &stat, sizeof(stat));
710                 datalen += sizeof(stat);
711         } else {
712                 if (a) {
713                         uint32_t leasetime = iface->dhcpv4_leasetime;
714                         if (leasetime == 0)
715                                 leasetime = 3600;
716                         else if (leasetime < 60)
717                                 leasetime = 60;
718
719                         uint32_t pref = leasetime;
720                         uint32_t valid = leasetime;
721
722                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
723                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
724                         size_t m = 0;
725
726                         for (size_t i = 0; i < addrlen; ++i)
727                                 if (addrs[i].preferred > addrs[m].preferred ||
728                                                 (addrs[i].preferred == addrs[m].preferred &&
729                                                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
730                                         m = i;
731
732                         for (size_t i = 0; i < addrlen; ++i) {
733                                 uint32_t prefix_pref = addrs[i].preferred;
734                                 uint32_t prefix_valid = addrs[i].valid;
735
736                                 if (addrs[i].prefix > 96 ||
737                                                 addrs[i].preferred <= (uint32_t)now)
738                                         continue;
739
740                                 if (prefix_pref != UINT32_MAX)
741                                         prefix_pref -= now;
742
743                                 if (prefix_valid != UINT32_MAX)
744                                         prefix_valid -= now;
745
746                                 if (a->length < 128) {
747                                         struct dhcpv6_ia_prefix p = {
748                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
749                                                 .len = htons(sizeof(p) - 4),
750                                                 .preferred = htonl(prefix_pref),
751                                                 .valid = htonl(prefix_valid),
752                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
753                                                 .addr = addrs[i].addr
754                                         };
755                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
756
757                                         size_t entrlen = sizeof(p) - 4;
758
759                                         if (datalen + entrlen + 4 > buflen ||
760                                                         (a->assigned == 0 && a->managed_size == 0) ||
761                                                         (!a->managed_size && a->length <= addrs[i].prefix))
762                                                 continue;
763
764                                         memcpy(buf + datalen, &p, sizeof(p));
765                                         datalen += entrlen + 4;
766                                 } else {
767                                         struct dhcpv6_ia_addr n = {
768                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
769                                                 .len = htons(sizeof(n) - 4),
770                                                 .addr = addrs[i].addr,
771                                                 .preferred = htonl(prefix_pref),
772                                                 .valid = htonl(prefix_valid)
773                                         };
774                                         n.addr.s6_addr32[3] = htonl(a->assigned);
775                                         size_t entrlen = sizeof(n) - 4;
776
777                                         if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
778                                                         addrs[i].prefix == 64)
779                                                 continue;
780
781                                         if (datalen + entrlen + 4 > buflen || a->assigned == 0)
782                                                 continue;
783
784                                         memcpy(buf + datalen, &n, sizeof(n));
785                                         datalen += entrlen + 4;
786                                 }
787
788                                 // Calculate T1 / T2 based on non-deprecated addresses
789                                 if (prefix_pref > 0) {
790                                         if (prefix_pref < pref)
791                                                 pref = prefix_pref;
792
793                                         if (prefix_valid < valid)
794                                                 valid = prefix_valid;
795                                 }
796                         }
797
798                         a->valid_until = valid + now;
799                         out.t1 = htonl(pref * 5 / 10);
800                         out.t2 = htonl(pref * 8 / 10);
801
802                         if (!out.t1)
803                                 out.t1 = htonl(1);
804
805                         if (!out.t2)
806                                 out.t2 = htonl(1);
807                 }
808
809                 if (!request) {
810                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
811                         uint16_t otype, olen;
812                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
813                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
814                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
815                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
816                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
817                                         continue;
818
819                                 bool found = false;
820                                 if (a) {
821                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
822                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
823
824                                         for (size_t i = 0; i < addrlen; ++i) {
825                                                 if (addrs[i].prefix > 96 ||
826                                                                 addrs[i].preferred <= (uint32_t)now)
827                                                         continue;
828
829                                                 struct in6_addr addr = addrs[i].addr;
830                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
831                                                         addr.s6_addr32[1] |= htonl(a->assigned);
832
833                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
834                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
835                                                                 found = true;
836                                                 } else {
837                                                         addr.s6_addr32[3] = htonl(a->assigned);
838
839                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
840                                                                 found = true;
841                                                 }
842                                         }
843                                 }
844
845                                 if (!found) {
846                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
847                                                 struct dhcpv6_ia_prefix inv = {
848                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
849                                                         .len = htons(sizeof(inv) - 4),
850                                                         .preferred = 0,
851                                                         .valid = 0,
852                                                         .prefix = p->prefix,
853                                                         .addr = p->addr
854                                                 };
855
856                                                 if (datalen + sizeof(inv) > buflen)
857                                                         continue;
858
859                                                 memcpy(buf + datalen, &inv, sizeof(inv));
860                                                 datalen += sizeof(inv);
861                                         } else {
862                                                 struct dhcpv6_ia_addr inv = {
863                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
864                                                         .len = htons(sizeof(inv) - 4),
865                                                         .addr = n->addr,
866                                                         .preferred = 0,
867                                                         .valid = 0
868                                                 };
869
870                                                 if (datalen + sizeof(inv) > buflen)
871                                                         continue;
872
873                                                 memcpy(buf + datalen, &inv, sizeof(inv));
874                                                 datalen += sizeof(inv);
875                                         }
876                                 }
877                         }
878                 }
879         }
880
881         out.len = htons(datalen - 4);
882         memcpy(buf, &out, sizeof(out));
883         return datalen;
884 }
885
886
887 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
888                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
889 {
890         const char *type = "UNKNOWN";
891         const char *status = "UNKNOWN";
892
893         if (msgtype == DHCPV6_MSG_RENEW)
894                 return;
895
896         switch (msgtype) {
897         case DHCPV6_MSG_SOLICIT:
898                 type = "SOLICIT";
899                 break;
900         case DHCPV6_MSG_REQUEST:
901                 type = "REQUEST";
902                 break;
903         case DHCPV6_MSG_CONFIRM:
904                 type = "CONFIRM";
905                 break;
906         case DHCPV6_MSG_RENEW:
907                 type = "RENEW";
908                 break;
909         case DHCPV6_MSG_REBIND:
910                 type = "REBIND";
911                 break;
912         case DHCPV6_MSG_RELEASE:
913                 type = "RELEASE";
914                 break;
915         case DHCPV6_MSG_DECLINE:
916                 type = "DECLINE";
917                 break;
918         }
919
920         switch (code) {
921         case DHCPV6_STATUS_OK:
922                 status = "ok";
923                 break;
924         case DHCPV6_STATUS_NOADDRSAVAIL:
925                 status = "no addresses available";
926                 break;
927         case DHCPV6_STATUS_NOBINDING:
928                 status = "no binding";
929                 break;
930         case DHCPV6_STATUS_NOTONLINK:
931                 status = "not on-link";
932                 break;
933         case DHCPV6_STATUS_NOPREFIXAVAIL:
934                 status = "no prefix available";
935                 break;
936         }
937
938         char leasebuf[256] = "";
939
940         if (a) {
941                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
942                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
943                 size_t lbsize = 0;
944                 char addrbuf[INET6_ADDRSTRLEN];
945
946                 for (size_t i = 0; i < addrlen; ++i) {
947                         if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
948                                 continue;
949
950                         struct in6_addr addr = addrs[i].addr;
951                         int prefix = a->managed ? addrs[i].prefix : a->length;
952                         if (prefix == 128)
953                                 addr.s6_addr32[3] = htonl(a->assigned);
954                         else
955                                 addr.s6_addr32[1] |= htonl(a->assigned);
956
957                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
958                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
959                 }
960         }
961
962         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
963                         duidbuf, iface->ifname, status, leasebuf);
964 }
965
966
967
968 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
969                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
970 {
971         time_t now = odhcpd_time();
972         size_t response_len = 0;
973         const struct dhcpv6_client_header *hdr = data;
974         uint8_t *start = (uint8_t*)&hdr[1], *odata;
975         uint16_t otype, olen;
976
977         // Find and parse client-id and hostname
978         bool accept_reconf = false;
979         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
980         char hostname[256];
981         size_t hostname_len = 0;
982         bool notonlink = false;
983         char duidbuf[261];
984
985         dhcpv6_for_each_option(start, end, otype, olen, odata) {
986                 if (otype == DHCPV6_OPT_CLIENTID) {
987                         clid_data = odata;
988                         clid_len = olen;
989
990                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
991                                 memcpy(mac, &odata[8], sizeof(mac));
992                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
993                                 memcpy(mac, &odata[4], sizeof(mac));
994
995                         if (olen <= 130)
996                                 odhcpd_hexlify(duidbuf, odata, olen);
997                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
998                         uint8_t fqdn_buf[256];
999                         memcpy(fqdn_buf, odata, olen);
1000                         fqdn_buf[olen++] = 0;
1001
1002                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1003                                 hostname_len = strcspn(hostname, ".");
1004                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
1005                         accept_reconf = true;
1006                 }
1007         }
1008
1009         if (!clid_data || !clid_len || clid_len > 130)
1010                 goto out;
1011
1012         update(iface);
1013
1014         struct dhcpv6_assignment *first = NULL;
1015         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1016                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1017                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1018                 bool ia_addr_present = false;
1019                 if (!is_pd && !is_na)
1020                         continue;
1021
1022                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1023                 size_t ia_response_len = 0;
1024                 uint8_t reqlen = (is_pd) ? 62 : 128;
1025                 uint32_t reqhint = 0;
1026
1027                 // Parse request hint for IA-PD
1028                 if (is_pd) {
1029                         uint8_t *sdata;
1030                         uint16_t stype, slen;
1031                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1032                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1033                                         continue;
1034
1035                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1036                                 if (p->prefix) {
1037                                         reqlen = p->prefix;
1038                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1039                                         if (reqlen > 32 && reqlen <= 64)
1040                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1041                                 }
1042                         }
1043
1044                         if (reqlen > 64)
1045                                 reqlen = 64;
1046                 } else if (is_na) {
1047                         uint8_t *sdata;
1048                         uint16_t stype, slen;
1049                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1050                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1051                                         continue;
1052
1053                                 ia_addr_present = true;
1054                         }
1055                 }
1056
1057                 // Find assignment
1058                 struct dhcpv6_assignment *c, *a = NULL;
1059                 list_for_each_entry(c, &iface->ia_assignments, head) {
1060                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1061                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1062                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1063                                         (c->iaid == ia->iaid || c->valid_until < now) &&
1064                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1065                                 a = c;
1066
1067                                 // Reset state
1068                                 apply_lease(iface, a, false);
1069                                 memcpy(a->clid_data, clid_data, clid_len);
1070                                 a->clid_len = clid_len;
1071                                 a->iaid = ia->iaid;
1072                                 a->peer = *addr;
1073                                 a->reconf_cnt = 0;
1074                                 a->reconf_sent = 0;
1075                                 break;
1076                         }
1077                 }
1078
1079                 // Generic message handling
1080                 uint16_t status = DHCPV6_STATUS_OK;
1081                 if (a && a->managed_size < 0) {
1082                         return -1;
1083                 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1084                         bool assigned = !!a;
1085
1086                         if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1087                                 a = calloc(1, sizeof(*a) + clid_len);
1088                                 if (a) {
1089                                         a->clid_len = clid_len;
1090                                         a->iaid = ia->iaid;
1091                                         a->length = reqlen;
1092                                         a->peer = *addr;
1093                                         a->assigned = reqhint;
1094
1095                                         if (first)
1096                                                 memcpy(a->key, first->key, sizeof(a->key));
1097                                         else
1098                                                 odhcpd_urandom(a->key, sizeof(a->key));
1099                                         memcpy(a->clid_data, clid_data, clid_len);
1100
1101                                         if (is_pd)
1102                                                 while (!(assigned = assign_pd(iface, a)) &&
1103                                                                 !a->managed_size && ++a->length <= 64);
1104                                         else
1105                                                 assigned = assign_na(iface, a);
1106
1107                                         if (a->managed_size && !assigned)
1108                                                 return -1;
1109                                 }
1110                         }
1111
1112                         if (!assigned || iface->ia_addr_len == 0) { // Set error status
1113                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1114                         } else if (assigned && !first) { //
1115                                 size_t handshake_len = 4;
1116                                 buf[0] = 0;
1117                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1118                                 buf[2] = 0;
1119                                 buf[3] = 0;
1120
1121                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1122                                         struct dhcpv6_auth_reconfigure auth = {
1123                                                 htons(DHCPV6_OPT_AUTH),
1124                                                 htons(sizeof(auth) - 4),
1125                                                 3, 1, 0,
1126                                                 {htonl(time(NULL)), htonl(++serial)},
1127                                                 1,
1128                                                 {0}
1129                                         };
1130                                         memcpy(auth.key, a->key, sizeof(a->key));
1131                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1132                                         handshake_len += sizeof(auth);
1133                                 }
1134
1135                                 buf += handshake_len;
1136                                 buflen -= handshake_len;
1137                                 response_len += handshake_len;
1138
1139                                 first = a;
1140                         }
1141
1142                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1143
1144                         // Was only a solicitation: mark binding for removal
1145                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1146                                 a->valid_until = 0;
1147                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1148                                 if (hostname_len > 0) {
1149                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1150                                         if (a->hostname) {
1151                                                 memcpy(a->hostname, hostname, hostname_len);
1152                                                 a->hostname[hostname_len] = 0;
1153                                         }
1154                                 }
1155                                 a->accept_reconf = accept_reconf;
1156                                 apply_lease(iface, a, true);
1157                         } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1158                                 free_dhcpv6_assignment(a);
1159                         }
1160                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1161                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1162                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1163                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1164                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1165                                 status = DHCPV6_STATUS_NOBINDING;
1166                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1167                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1168                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1169                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1170                                 if (a)
1171                                         apply_lease(iface, a, true);
1172                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1173                                 a->valid_until = 0;
1174                                 apply_lease(iface, a, false);
1175                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1176                                 a->clid_len = 0;
1177                                 a->valid_until = now + 3600; // Block address for 1h
1178                         }
1179                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1180                         // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1181                         status = DHCPV6_STATUS_NOTONLINK;
1182                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1183                         notonlink = true;
1184                 }
1185
1186                 buf += ia_response_len;
1187                 buflen -= ia_response_len;
1188                 response_len += ia_response_len;
1189                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1190         }
1191
1192         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1193                         response_len + 6 < buflen) {
1194                 buf[0] = 0;
1195                 buf[1] = DHCPV6_OPT_STATUS;
1196                 buf[2] = 0;
1197                 buf[3] = 2;
1198                 buf[4] = 0;
1199                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1200                 response_len += 6;
1201         }
1202
1203         dhcpv6_write_statefile();
1204
1205 out:
1206         return response_len;
1207 }