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Sources/odhcpd/src/dhcpv4.c

  1 /**
  2  * Copyright (C) 2012-2013 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 
 17 #include <time.h>
 18 #include <errno.h>
 19 #include <fcntl.h>
 20 #include <unistd.h>
 21 #include <stddef.h>
 22 #include <stdlib.h>
 23 #include <resolv.h>
 24 #include <limits.h>
 25 #include <net/if.h>
 26 #include <net/if_arp.h>
 27 #include <netinet/ip.h>
 28 #include <sys/ioctl.h>
 29 #include <sys/timerfd.h>
 30 #include <arpa/inet.h>
 31 
 32 #include <libubox/md5.h>
 33 
 34 #include "odhcpd.h"
 35 #include "dhcpv4.h"
 36 #include "dhcpv6.h"
 37 
 38 #define PACKET_SIZE(start, end) (((uint8_t *)end - (uint8_t *)start) < DHCPV4_MIN_PACKET_SIZE ? \
 39                                  DHCPV4_MIN_PACKET_SIZE : (uint8_t *)end - (uint8_t *)start)
 40 
 41 static void dhcpv4_netevent_cb(unsigned long event, struct netevent_handler_info *info);
 42 static int setup_dhcpv4_addresses(struct interface *iface);
 43 static bool addr_is_fr_ip(struct interface *iface, struct in_addr *addr);
 44 static void valid_until_cb(struct uloop_timeout *event);
 45 static void handle_addrlist_change(struct interface *iface);
 46 static void dhcpv4_fr_start(struct dhcp_assignment *a);
 47 static void dhcpv4_fr_rand_delay(struct dhcp_assignment *a);
 48 static void dhcpv4_fr_stop(struct dhcp_assignment *a);
 49 static void handle_dhcpv4(void *addr, void *data, size_t len,
 50                 struct interface *iface, void *dest_addr);
 51 static struct dhcp_assignment* dhcpv4_lease(struct interface *iface,
 52                 enum dhcpv4_msg msg, const uint8_t *mac, const uint32_t reqaddr,
 53                 uint32_t *leasetime, const char *hostname, const size_t hostname_len,
 54                 const bool accept_fr_nonce, bool *incl_fr_opt, uint32_t *fr_serverid,
 55                 const char *reqopts, const size_t reqopts_len);
 56 
 57 static struct netevent_handler dhcpv4_netevent_handler = { .cb = dhcpv4_netevent_cb, };
 58 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
 59 static uint32_t serial = 0;
 60 
 61 struct odhcpd_ref_ip {
 62         struct list_head head;
 63         int ref_cnt;
 64         struct odhcpd_ipaddr addr;
 65 };
 66 
 67 /* Create socket and register events */
 68 int dhcpv4_init(void)
 69 {
 70         uloop_timeout_set(&valid_until_timeout, 1000);
 71         netlink_add_netevent_handler(&dhcpv4_netevent_handler);
 72 
 73         return 0;
 74 }
 75 
 76 int dhcpv4_setup_interface(struct interface *iface, bool enable)
 77 {
 78         int ret = 0;
 79 
 80         enable = enable && (iface->dhcpv4 != MODE_DISABLED);
 81 
 82         if (iface->dhcpv4_event.uloop.fd >= 0) {
 83                 uloop_fd_delete(&iface->dhcpv4_event.uloop);
 84                 close(iface->dhcpv4_event.uloop.fd);
 85                 iface->dhcpv4_event.uloop.fd = -1;
 86         }
 87 
 88         if (enable) {
 89                 struct sockaddr_in bind_addr = {AF_INET, htons(DHCPV4_SERVER_PORT),
 90                                         {INADDR_ANY}, {0}};
 91                 int val = 1;
 92 
 93                 iface->dhcpv4_event.uloop.fd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 94                 if (iface->dhcpv4_event.uloop.fd < 0) {
 95                         syslog(LOG_ERR, "socket(AF_INET): %m");
 96                         ret = -1;
 97                         goto out;
 98                 }
 99 
100                 /* Basic IPv4 configuration */
101                 if (setsockopt(iface->dhcpv4_event.uloop.fd, SOL_SOCKET, SO_REUSEADDR,
102                                         &val, sizeof(val)) < 0) {
103                         syslog(LOG_ERR, "setsockopt(SO_REUSEADDR): %m");
104                         ret = -1;
105                         goto out;
106                 }
107 
108                 if (setsockopt(iface->dhcpv4_event.uloop.fd, SOL_SOCKET, SO_BROADCAST,
109                                         &val, sizeof(val)) < 0) {
110                         syslog(LOG_ERR, "setsockopt(SO_BROADCAST): %m");
111                         ret = -1;
112                         goto out;
113                 }
114 
115                 if (setsockopt(iface->dhcpv4_event.uloop.fd, IPPROTO_IP, IP_PKTINFO,
116                                         &val, sizeof(val)) < 0) {
117                         syslog(LOG_ERR, "setsockopt(IP_PKTINFO): %m");
118                         ret = -1;
119                         goto out;
120                 }
121 
122                 val = IPTOS_PREC_INTERNETCONTROL;
123                 if (setsockopt(iface->dhcpv4_event.uloop.fd, IPPROTO_IP, IP_TOS,
124                                         &val, sizeof(val)) < 0) {
125                         syslog(LOG_ERR, "setsockopt(IP_TOS): %m");
126                         ret = -1;
127                         goto out;
128                 }
129 
130                 val = IP_PMTUDISC_DONT;
131                 if (setsockopt(iface->dhcpv4_event.uloop.fd, IPPROTO_IP, IP_MTU_DISCOVER,
132                                         &val, sizeof(val)) < 0) {
133                         syslog(LOG_ERR, "setsockopt(IP_MTU_DISCOVER): %m");
134                         ret = -1;
135                         goto out;
136                 }
137 
138                 if (setsockopt(iface->dhcpv4_event.uloop.fd, SOL_SOCKET, SO_BINDTODEVICE,
139                                         iface->ifname, strlen(iface->ifname)) < 0) {
140                         syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
141                         ret = -1;
142                         goto out;
143                 }
144 
145                 if (bind(iface->dhcpv4_event.uloop.fd, (struct sockaddr*)&bind_addr,
146                                         sizeof(bind_addr)) < 0) {
147                         syslog(LOG_ERR, "bind(): %m");
148                         ret = -1;
149                         goto out;
150                 }
151 
152                 if (setup_dhcpv4_addresses(iface) < 0) {
153                         ret = -1;
154                         goto out;
155                 }
156 
157                 iface->dhcpv4_event.handle_dgram = handle_dhcpv4;
158                 odhcpd_register(&iface->dhcpv4_event);
159         } else {
160                 while (!list_empty(&iface->dhcpv4_assignments))
161                         free_assignment(list_first_entry(&iface->dhcpv4_assignments,
162                                                         struct dhcp_assignment, head));
163         }
164 
165 out:
166         if (ret < 0 && iface->dhcpv4_event.uloop.fd >= 0) {
167                 close(iface->dhcpv4_event.uloop.fd);
168                 iface->dhcpv4_event.uloop.fd = -1;
169         }
170 
171         return ret;
172 }
173 
174 
175 static void dhcpv4_netevent_cb(unsigned long event, struct netevent_handler_info *info)
176 {
177         struct interface *iface = info->iface;
178 
179         if (!iface || iface->dhcpv4 == MODE_DISABLED)
180                 return;
181 
182         switch (event) {
183         case NETEV_IFINDEX_CHANGE:
184                 dhcpv4_setup_interface(iface, true);
185                 break;
186         case NETEV_ADDRLIST_CHANGE:
187                 handle_addrlist_change(iface);
188                 break;
189         default:
190                 break;
191         }
192 }
193 
194 static struct dhcp_assignment *find_assignment_by_hwaddr(struct interface *iface, const uint8_t *hwaddr)
195 {
196         struct dhcp_assignment *a;
197 
198         list_for_each_entry(a, &iface->dhcpv4_assignments, head)
199                 if (!memcmp(a->hwaddr, hwaddr, 6))
200                         return a;
201 
202         return NULL;
203 }
204 
205 static int setup_dhcpv4_addresses(struct interface *iface)
206 {
207         iface->dhcpv4_start_ip.s_addr = INADDR_ANY;
208         iface->dhcpv4_end_ip.s_addr = INADDR_ANY;
209         iface->dhcpv4_local.s_addr = INADDR_ANY;
210         iface->dhcpv4_bcast.s_addr = INADDR_ANY;
211         iface->dhcpv4_mask.s_addr = INADDR_ANY;
212 
213         /* Sanity checks */
214         if (iface->dhcpv4_start.s_addr & htonl(0xffff0000) ||
215             iface->dhcpv4_end.s_addr & htonl(0xffff0000) ||
216             ntohl(iface->dhcpv4_start.s_addr) > ntohl(iface->dhcpv4_end.s_addr)) {
217                 syslog(LOG_WARNING, "Invalid DHCP range for %s", iface->name);
218                 return -1;
219         }
220 
221         if (!iface->addr4_len) {
222                 syslog(LOG_WARNING, "No network(s) available on %s", iface->name);
223                 return -1;
224         }
225 
226         uint32_t start = ntohl(iface->dhcpv4_start.s_addr);
227         uint32_t end = ntohl(iface->dhcpv4_end.s_addr);
228 
229         for (size_t i = 0; i < iface->addr4_len && start && end; i++) {
230                 struct in_addr *addr = &iface->addr4[i].addr.in;
231                 struct in_addr mask;
232 
233                 if (addr_is_fr_ip(iface, addr))
234                         continue;
235 
236                 odhcpd_bitlen2netmask(false, iface->addr4[i].prefix, &mask);
237                 if ((start & ntohl(~mask.s_addr)) == start &&
238                                 (end & ntohl(~mask.s_addr)) == end &&
239                                 end < ntohl(~mask.s_addr)) {    /* Exclude broadcast address */
240                         iface->dhcpv4_start_ip.s_addr = htonl(start) |
241                                                         (addr->s_addr & mask.s_addr);
242                         iface->dhcpv4_end_ip.s_addr = htonl(end) |
243                                                         (addr->s_addr & mask.s_addr);
244                         iface->dhcpv4_local = *addr;
245                         iface->dhcpv4_bcast = iface->addr4[i].broadcast;
246                         iface->dhcpv4_mask = mask;
247                         return 0;
248                 }
249         }
250 
251         /* Don't allocate IP range for subnets bigger than 28 */
252         if (iface->addr4[0].prefix > 28) {
253                 syslog(LOG_WARNING, "Auto allocation of DHCP range fails on %s", iface->name);
254                 return -1;
255         }
256 
257         iface->dhcpv4_local = iface->addr4[0].addr.in;
258         iface->dhcpv4_bcast = iface->addr4[0].broadcast;
259         odhcpd_bitlen2netmask(false, iface->addr4[0].prefix, &iface->dhcpv4_mask);
260         end = start = iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr;
261 
262         /* Auto allocate ranges */
263         if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff00) {           /* /24, 150 of 256, [100..249] */
264                 iface->dhcpv4_start_ip.s_addr = start | htonl(100);
265                 iface->dhcpv4_end_ip.s_addr = end | htonl(100 + 150 - 1);
266         } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff80) {    /* /25, 100 of 128, [20..119] */
267                 iface->dhcpv4_start_ip.s_addr = start | htonl(20);
268                 iface->dhcpv4_end_ip.s_addr = end | htonl(20 + 100 - 1);
269         } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffc0) {    /* /26, 50 of 64, [10..59] */
270                 iface->dhcpv4_start_ip.s_addr = start | htonl(10);
271                 iface->dhcpv4_end_ip.s_addr = end | htonl(10 + 50 - 1);
272         } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffe0) {    /* /27, 20 of 32, [10..29] */
273                 iface->dhcpv4_start_ip.s_addr = start | htonl(10);
274                 iface->dhcpv4_end_ip.s_addr = end | htonl(10 + 20 - 1);
275         } else {                                                        /* /28, 10 of 16, [3..12] */
276                 iface->dhcpv4_start_ip.s_addr = start | htonl(3);
277                 iface->dhcpv4_end_ip.s_addr = end | htonl(3 + 10 - 1);
278         }
279 
280         return 0;
281 }
282 
283 static void inc_ref_cnt_ip(struct odhcpd_ref_ip **ptr, struct odhcpd_ref_ip *ip)
284 {
285         *ptr = ip;
286         ip->ref_cnt++;
287 }
288 
289 static void decr_ref_cnt_ip(struct odhcpd_ref_ip **ptr, struct interface *iface)
290 {
291         struct odhcpd_ref_ip *ip = *ptr;
292 
293         if (--ip->ref_cnt == 0) {
294                 netlink_setup_addr(&ip->addr, iface->ifindex, false, false);
295 
296                 list_del(&ip->head);
297                 free(ip);
298         }
299 
300         *ptr = NULL;
301 }
302 
303 static bool addr_is_fr_ip(struct interface *iface, struct in_addr *addr)
304 {
305         struct odhcpd_ref_ip *p;
306 
307         list_for_each_entry(p, &iface->dhcpv4_fr_ips, head) {
308                 if (addr->s_addr == p->addr.addr.in.s_addr)
309                         return true;
310         }
311 
312         return false;
313 }
314 
315 static bool leases_require_fr(struct interface *iface, struct odhcpd_ipaddr *addr,
316                                 uint32_t mask)
317 {
318         struct dhcp_assignment *a = NULL;
319         struct odhcpd_ref_ip *fr_ip = NULL;
320 
321         list_for_each_entry(a, &iface->dhcpv4_assignments, head) {
322                 if ((a->accept_fr_nonce || iface->dhcpv4_forcereconf) &&
323                     !a->fr_ip &&
324                     ((a->addr & mask) == (addr->addr.in.s_addr & mask))) {
325                         if (!fr_ip) {
326                                 fr_ip = calloc(1, sizeof(*fr_ip));
327                                 if (!fr_ip)
328                                         break;
329 
330                                 list_add(&fr_ip->head, &iface->dhcpv4_fr_ips);
331                                 fr_ip->addr = *addr;
332                         }
333                         inc_ref_cnt_ip(&a->fr_ip, fr_ip);
334                 }
335         }
336 
337         return fr_ip ? true : false;
338 }
339 
340 static void valid_until_cb(struct uloop_timeout *event)
341 {
342         struct interface *iface;
343         time_t now = odhcpd_time();
344 
345         avl_for_each_element(&interfaces, iface, avl) {
346                 struct dhcp_assignment *a, *n;
347 
348                 if (iface->dhcpv4 != MODE_SERVER)
349                         continue;
350 
351                 list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) {
352                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now)
353                                 free_assignment(a);
354                 }
355         }
356         uloop_timeout_set(event, 1000);
357 }
358 
359 static void handle_addrlist_change(struct interface *iface)
360 {
361         struct odhcpd_ipaddr ip;
362         struct odhcpd_ref_ip *a;
363         struct dhcp_assignment *c;
364         uint32_t mask = iface->dhcpv4_mask.s_addr;
365 
366         memset(&ip, 0, sizeof(ip));
367         ip.addr.in = iface->dhcpv4_local;
368         ip.prefix = odhcpd_netmask2bitlen(false, &iface->dhcpv4_mask);
369         ip.broadcast = iface->dhcpv4_bcast;
370 
371         setup_dhcpv4_addresses(iface);
372 
373         if ((ip.addr.in.s_addr & mask) ==
374             (iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr))
375                 return;
376 
377         if (ip.addr.in.s_addr && !leases_require_fr(iface, &ip, mask))
378                 return;
379 
380         if (iface->dhcpv4_local.s_addr == INADDR_ANY || list_empty(&iface->dhcpv4_fr_ips))
381                 return;
382 
383         a = list_first_entry(&iface->dhcpv4_fr_ips, struct odhcpd_ref_ip, head);
384 
385         if (netlink_setup_addr(&a->addr, iface->ifindex, false, true)) {
386                 syslog(LOG_WARNING, "Failed to add ip address on %s", iface->name);
387                 return;
388         }
389 
390         list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
391                 if ((c->flags & OAF_BOUND) && c->fr_ip && !c->fr_cnt) {
392                         if (c->accept_fr_nonce || iface->dhcpv4_forcereconf)
393                                 dhcpv4_fr_rand_delay(c);
394                         else
395                                 dhcpv4_fr_stop(c);
396                 }
397         }
398 }
399 
400 static char *dhcpv4_msg_to_string(uint8_t reqmsg)
401 {
402         switch (reqmsg) {
403         case (DHCPV4_MSG_DISCOVER):
404                 return "DHCPV4_MSG_DISCOVER";
405         case (DHCPV4_MSG_OFFER):
406                 return "DHCPV4_MSG_OFFER";
407         case (DHCPV4_MSG_REQUEST):
408                 return "DHCPV4_MSG_REQUEST";
409         case (DHCPV4_MSG_DECLINE):
410                 return "DHCPV4_MSG_DECLINE";
411         case (DHCPV4_MSG_ACK):
412                 return "DHCPV4_MSG_ACK";
413         case (DHCPV4_MSG_NAK):
414                 return "DHCPV4_MSG_NAK";
415         case (DHCPV4_MSG_RELEASE):
416                 return "DHCPV4_MSG_RELEASE";
417         case (DHCPV4_MSG_INFORM):
418                 return "DHCPV4_MSG_INFORM";
419         case (DHCPV4_MSG_FORCERENEW):
420                 return "DHCPV4_MSG_FORCERENEW";
421         default:
422                 return "UNKNOWN";
423         }
424 }
425 
426 static void dhcpv4_free_assignment(struct dhcp_assignment *a)
427 {
428         if (a->fr_ip)
429                 dhcpv4_fr_stop(a);
430 }
431 
432 static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie,
433                 uint8_t type, uint8_t len, const void *data)
434 {
435         uint8_t *c = *cookie;
436         uint8_t *end = (uint8_t *)msg + sizeof(*msg);
437         bool tag_only = type == DHCPV4_OPT_PAD || type == DHCPV4_OPT_END;
438         int total_len = tag_only ? 1 : 2 + len;
439 
440         if (*cookie + total_len > end)
441                 return;
442 
443         *cookie += total_len;
444         *c++ = type;
445 
446         if (tag_only)
447                 return;
448 
449         *c++ = len;
450         memcpy(c, data, len);
451 }
452 
453 static void dhcpv4_fr_send(struct dhcp_assignment *a)
454 {
455         struct dhcpv4_message fr_msg = {
456                 .op = DHCPV4_BOOTREPLY,
457                 .htype = 1,
458                 .hlen = 6,
459                 .hops = 0,
460                 .secs = 0,
461                 .flags = 0,
462                 .ciaddr = {INADDR_ANY},
463                 .yiaddr = {INADDR_ANY},
464                 .siaddr = {INADDR_ANY},
465                 .giaddr = {INADDR_ANY},
466                 .chaddr = {0},
467                 .sname = {0},
468                 .file = {0},
469         };
470         struct dhcpv4_auth_forcerenew *auth_o, auth = {
471                 .protocol = 3,
472                 .algorithm = 1,
473                 .rdm = 0,
474                 .replay = {htonl(time(NULL)), htonl(++serial)},
475                 .type = 2,
476                 .key = {0},
477         };
478         struct interface *iface = a->iface;
479 
480         odhcpd_urandom(&fr_msg.xid, sizeof(fr_msg.xid));
481         memcpy(fr_msg.chaddr, a->hwaddr, fr_msg.hlen);
482 
483         fr_msg.options[0] = 0x63;
484         fr_msg.options[1] = 0x82;
485         fr_msg.options[2] = 0x53;
486         fr_msg.options[3] = 0x63;
487 
488         uint8_t *cookie = &fr_msg.options[4];
489         uint8_t msg = DHCPV4_MSG_FORCERENEW;
490 
491         dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_MESSAGE, 1, &msg);
492         if (a->accept_fr_nonce) {
493                 dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
494                 auth_o = (struct dhcpv4_auth_forcerenew *)(cookie - sizeof(auth));
495                 dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL);
496 
497                 md5_ctx_t md5;
498                 uint8_t secretbytes[64];
499                 memset(secretbytes, 0, sizeof(secretbytes));
500                 memcpy(secretbytes, a->key, sizeof(a->key));
501 
502                 for (size_t i = 0; i < sizeof(secretbytes); ++i)
503                         secretbytes[i] ^= 0x36;
504 
505                 md5_begin(&md5);
506                 md5_hash(secretbytes, sizeof(secretbytes), &md5);
507                 md5_hash(&fr_msg, sizeof(fr_msg), &md5);
508                 md5_end(auth_o->key, &md5);
509 
510                 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
511                         secretbytes[i] ^= 0x36;
512                         secretbytes[i] ^= 0x5c;
513                 }
514 
515                 md5_begin(&md5);
516                 md5_hash(secretbytes, sizeof(secretbytes), &md5);
517                 md5_hash(auth_o->key, sizeof(auth_o->key), &md5);
518                 md5_end(auth_o->key, &md5);
519         } else {
520                 dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_SERVERID, 4,
521                                 &a->fr_ip->addr.addr.in.s_addr);
522                 dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL);
523         }
524 
525         struct sockaddr_in dest;
526         memset(&dest, 0, sizeof(dest));
527         dest.sin_family = AF_INET;
528         dest.sin_port = htons(DHCPV4_CLIENT_PORT);
529         dest.sin_addr.s_addr = a->addr;
530 
531         if (sendto(iface->dhcpv4_event.uloop.fd, &fr_msg, PACKET_SIZE(&fr_msg, cookie),
532                         MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)) < 0)
533                 syslog(LOG_ERR, "Failed to send %s to %s - %s: %m", dhcpv4_msg_to_string(msg),
534                         odhcpd_print_mac(a->hwaddr, sizeof(a->hwaddr)), inet_ntoa(dest.sin_addr));
535         else
536                 syslog(LOG_DEBUG, "Sent %s to %s - %s", dhcpv4_msg_to_string(msg),
537                         odhcpd_print_mac(a->hwaddr, sizeof(a->hwaddr)), inet_ntoa(dest.sin_addr));
538 }
539 
540 static void dhcpv4_fr_timer(struct uloop_timeout *event)
541 {
542         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, fr_timer);
543 
544         if (a->fr_cnt > 0 && a->fr_cnt < 8) {
545                 dhcpv4_fr_send(a);
546                 uloop_timeout_set(&a->fr_timer, 1000 << a->fr_cnt);
547                 a->fr_cnt++;
548         } else
549                 dhcpv4_fr_stop(a);
550 }
551 
552 static void dhcpv4_fr_start(struct dhcp_assignment *a)
553 {
554         uloop_timeout_set(&a->fr_timer, 1000 << a->fr_cnt);
555         a->fr_timer.cb = dhcpv4_fr_timer;
556         a->fr_cnt++;
557 
558         dhcpv4_fr_send(a);
559 }
560 
561 static void dhcpv4_fr_delay_timer(struct uloop_timeout *event)
562 {
563         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, fr_timer);
564         struct interface *iface = a->iface;
565 
566         (iface->dhcpv4_event.uloop.fd == -1 ? dhcpv4_fr_rand_delay(a) : dhcpv4_fr_start(a));
567 }
568 
569 static void dhcpv4_fr_rand_delay(struct dhcp_assignment *a)
570 {
571 #define MIN_DELAY   500
572 #define MAX_FUZZ    500
573         int msecs;
574 
575         odhcpd_urandom(&msecs, sizeof(msecs));
576 
577         msecs = labs(msecs)%MAX_FUZZ + MIN_DELAY;
578 
579         uloop_timeout_set(&a->fr_timer, msecs);
580         a->fr_timer.cb = dhcpv4_fr_delay_timer;
581 }
582 
583 static void dhcpv4_fr_stop(struct dhcp_assignment *a)
584 {
585         uloop_timeout_cancel(&a->fr_timer);
586         decr_ref_cnt_ip(&a->fr_ip, a->iface);
587         a->fr_cnt = 0;
588         a->fr_timer.cb = NULL;
589 }
590 
591 /* Handler for DHCPv4 messages */
592 static void handle_dhcpv4(void *addr, void *data, size_t len,
593                 struct interface *iface, _unused void *dest_addr)
594 {
595         struct dhcpv4_message *req = data;
596 
597         if (iface->dhcpv4 == MODE_DISABLED)
598                 return;
599 
600         if (len < offsetof(struct dhcpv4_message, options) + 4 ||
601                         req->op != DHCPV4_BOOTREQUEST || req->hlen != 6)
602                 return;
603 
604         syslog(LOG_DEBUG, "Got DHCPv4 request on %s", iface->name);
605 
606         if (!iface->dhcpv4_start_ip.s_addr && !iface->dhcpv4_end_ip.s_addr) {
607                 syslog(LOG_WARNING, "No DHCP range available on %s", iface->name);
608                 return;
609         }
610 
611         int sock = iface->dhcpv4_event.uloop.fd;
612 
613         struct dhcpv4_message reply = {
614                 .op = DHCPV4_BOOTREPLY,
615                 .htype = req->htype,
616                 .hlen = req->hlen,
617                 .hops = 0,
618                 .xid = req->xid,
619                 .secs = 0,
620                 .flags = req->flags,
621                 .ciaddr = {INADDR_ANY},
622                 .giaddr = req->giaddr,
623                 .siaddr = iface->dhcpv4_local,
624         };
625         memcpy(reply.chaddr, req->chaddr, sizeof(reply.chaddr));
626 
627         reply.options[0] = 0x63;
628         reply.options[1] = 0x82;
629         reply.options[2] = 0x53;
630         reply.options[3] = 0x63;
631 
632         uint8_t *cookie = &reply.options[4];
633         uint8_t reqmsg = DHCPV4_MSG_REQUEST;
634         uint8_t msg = DHCPV4_MSG_ACK;
635 
636         uint32_t reqaddr = INADDR_ANY;
637         uint32_t leasetime = 0;
638         size_t hostname_len = 0;
639         size_t reqopts_len = 0;
640         char hostname[256];
641         char reqopts[256];
642         bool accept_fr_nonce = false;
643         bool incl_fr_opt = false;
644 
645         uint8_t *start = &req->options[4];
646         uint8_t *end = ((uint8_t*)data) + len;
647         struct dhcpv4_option *opt;
648         dhcpv4_for_each_option(start, end, opt) {
649                 if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1)
650                         reqmsg = opt->data[0];
651                 else if (opt->type == DHCPV4_OPT_REQOPTS && opt->len > 0) {
652                         reqopts_len = opt->len;
653                         memcpy(reqopts, opt->data, reqopts_len);
654                         reqopts[reqopts_len] = 0;
655                 } else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) {
656                         hostname_len = opt->len;
657                         memcpy(hostname, opt->data, hostname_len);
658                         hostname[hostname_len] = 0;
659                 } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4)
660                         memcpy(&reqaddr, opt->data, 4);
661                 else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) {
662                         if (memcmp(opt->data, &iface->dhcpv4_local, 4))
663                                 return;
664                 } else if (iface->filter_class && opt->type == DHCPV4_OPT_USER_CLASS) {
665                         uint8_t *c = opt->data, *cend = &opt->data[opt->len];
666                         for (; c < cend && &c[*c] < cend; c = &c[1 + *c]) {
667                                 size_t elen = strlen(iface->filter_class);
668                                 if (*c == elen && !memcmp(&c[1], iface->filter_class, elen))
669                                         return; // Ignore from homenet
670                         }
671                 } else if (opt->type == DHCPV4_OPT_LEASETIME && opt->len == 4)
672                         memcpy(&leasetime, opt->data, 4);
673                 else if (opt->type == DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE && opt->len > 0) {
674                         for (uint8_t i = 0; i < opt->len; i++) {
675                                 if (opt->data[i] == 1) {
676                                         accept_fr_nonce = true;
677                                         break;
678                                 }
679                         }
680 
681                 }
682         }
683 
684         if (reqmsg != DHCPV4_MSG_DISCOVER && reqmsg != DHCPV4_MSG_REQUEST &&
685             reqmsg != DHCPV4_MSG_INFORM && reqmsg != DHCPV4_MSG_DECLINE &&
686             reqmsg != DHCPV4_MSG_RELEASE)
687                 return;
688 
689         struct dhcp_assignment *a = NULL;
690         uint32_t serverid = iface->dhcpv4_local.s_addr;
691         uint32_t fr_serverid = INADDR_ANY;
692 
693         if (reqmsg != DHCPV4_MSG_INFORM)
694                 a = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr,
695                                  &leasetime, hostname, hostname_len,
696                                  accept_fr_nonce, &incl_fr_opt, &fr_serverid,
697                                  reqopts, reqopts_len);
698 
699         if (!a) {
700                 if (reqmsg == DHCPV4_MSG_REQUEST)
701                         msg = DHCPV4_MSG_NAK;
702                 else if (reqmsg == DHCPV4_MSG_DISCOVER)
703                         return;
704         } else if (reqmsg == DHCPV4_MSG_DISCOVER)
705                 msg = DHCPV4_MSG_OFFER;
706         else if (reqmsg == DHCPV4_MSG_REQUEST &&
707                         ((reqaddr && reqaddr != a->addr) ||
708                          (req->ciaddr.s_addr && req->ciaddr.s_addr != a->addr))) {
709                 msg = DHCPV4_MSG_NAK;
710                 /*
711                  * DHCP client requested an IP which we can't offer to him. Probably the
712                  * client changed the network or the network has been changed. The reply
713                  * type is set to DHCPV4_MSG_NAK, because the client should not use that IP.
714                  *
715                  * For modern devices we build an answer that includes a valid IP, like
716                  * a DHCPV4_MSG_ACK. The client will use that IP and doesn't need to
717                  * perform additional DHCP round trips.
718                  *
719                  */
720 
721                 /*
722                  *
723                  * Buggy clients do serverid checking in nack messages; therefore set the
724                  * serverid in nack messages triggered by a previous force renew equal to
725                  * the server id in use at that time by the server
726                  *
727                  */
728                 if (fr_serverid)
729                         serverid = fr_serverid;
730 
731                 if (req->ciaddr.s_addr &&
732                                 ((iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr) !=
733                                  (req->ciaddr.s_addr & iface->dhcpv4_mask.s_addr)))
734                         req->ciaddr.s_addr = INADDR_ANY;
735         }
736 
737         syslog(LOG_INFO, "Received %s from %s on %s", dhcpv4_msg_to_string(reqmsg),
738                         odhcpd_print_mac(req->chaddr, req->hlen), iface->name);
739 
740 #ifdef WITH_UBUS
741         if (reqmsg == DHCPV4_MSG_RELEASE)
742                 ubus_bcast_dhcp_event("dhcp.release", req->chaddr, req->hlen,
743                                         &req->ciaddr, hostname, iface->ifname);
744 #endif
745         if (reqmsg == DHCPV4_MSG_DECLINE || reqmsg == DHCPV4_MSG_RELEASE)
746                 return;
747 
748         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MESSAGE, 1, &msg);
749         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SERVERID, 4, &serverid);
750 
751         if (a) {
752                 uint32_t val;
753 
754                 reply.yiaddr.s_addr = a->addr;
755 
756                 val = htonl(leasetime);
757                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_LEASETIME, 4, &val);
758 
759                 if (leasetime != UINT32_MAX) {
760                         val = htonl(500 * leasetime / 1000);
761                         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_RENEW, 4, &val);
762 
763                         val = htonl(875 * leasetime / 1000);
764                         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_REBIND, 4, &val);
765                 }
766 
767                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4,
768                                 &iface->dhcpv4_mask.s_addr);
769 
770                 if (a->hostname)
771                         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_HOSTNAME,
772                                         strlen(a->hostname), a->hostname);
773 
774                 if (iface->dhcpv4_bcast.s_addr != INADDR_ANY)
775                         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_BROADCAST, 4, &iface->dhcpv4_bcast);
776 
777                 if (incl_fr_opt) {
778                         if (reqmsg == DHCPV4_MSG_REQUEST) {
779                                 struct dhcpv4_auth_forcerenew auth = {
780                                         .protocol = 3,
781                                         .algorithm = 1,
782                                         .rdm = 0,
783                                         .replay = {htonl(time(NULL)), htonl(++serial)},
784                                         .type = 1,
785                                         .key = {0},
786                                 };
787 
788                                 memcpy(auth.key, a->key, sizeof(auth.key));
789                                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
790                         } else {
791                                 uint8_t one = 1;
792                                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE,
793                                         sizeof(one), &one);
794                         }
795                 }
796         }
797 
798         struct ifreq ifr;
799 
800         memset(&ifr, 0, sizeof(ifr));
801         strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name) - 1);
802 
803         if (!ioctl(sock, SIOCGIFMTU, &ifr)) {
804                 uint16_t mtu = htons(ifr.ifr_mtu);
805                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MTU, 2, &mtu);
806         }
807 
808         if (iface->search && iface->search_len <= 255)
809                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN,
810                                 iface->search_len, iface->search);
811         else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
812                 uint8_t search_buf[256];
813                 int len = dn_comp(_res.dnsrch[0], search_buf,
814                                                 sizeof(search_buf), NULL, NULL);
815                 if (len > 0)
816                         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN,
817                                         len, search_buf);
818         }
819 
820         if (iface->dhcpv4_router_cnt == 0)
821                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &iface->dhcpv4_local);
822         else
823                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER,
824                                 4 * iface->dhcpv4_router_cnt, iface->dhcpv4_router);
825 
826 
827         if (iface->dhcpv4_dns_cnt == 0)
828                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER, 4, &iface->dhcpv4_local);
829         else
830                 dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER,
831                                 4 * iface->dhcpv4_dns_cnt, iface->dhcpv4_dns);
832 
833 
834         dhcpv4_put(&reply, &cookie, DHCPV4_OPT_END, 0, NULL);
835 
836         struct sockaddr_in dest = *((struct sockaddr_in*)addr);
837         if (req->giaddr.s_addr) {
838                 /*
839                  * relay agent is configured, send reply to the agent
840                  */
841                 dest.sin_addr = req->giaddr;
842                 dest.sin_port = htons(DHCPV4_SERVER_PORT);
843         } else if (req->ciaddr.s_addr && req->ciaddr.s_addr != dest.sin_addr.s_addr) {
844                 /*
845                  * client has existing configuration (ciaddr is set) AND this address is
846                  * not the address it used for the dhcp message
847                  */
848                 dest.sin_addr = req->ciaddr;
849                 dest.sin_port = htons(DHCPV4_CLIENT_PORT);
850         } else if ((ntohs(req->flags) & DHCPV4_FLAG_BROADCAST) ||
851                         req->hlen != reply.hlen || !reply.yiaddr.s_addr) {
852                 /*
853                  * client requests a broadcast reply OR we can't offer an IP
854                  */
855                 dest.sin_addr.s_addr = INADDR_BROADCAST;
856                 dest.sin_port = htons(DHCPV4_CLIENT_PORT);
857         } else if (!req->ciaddr.s_addr && msg == DHCPV4_MSG_NAK) {
858                 /*
859                  * client has no previous configuration -> no IP, so we need to reply
860                  * with a broadcast packet
861                  */
862                 dest.sin_addr.s_addr = INADDR_BROADCAST;
863                 dest.sin_port = htons(DHCPV4_CLIENT_PORT);
864         } else {
865                 struct arpreq arp = {.arp_flags = ATF_COM};
866 
867                 /*
868                  * send reply to the newly (in this proccess) allocated IP
869                  */
870                 dest.sin_addr = reply.yiaddr;
871                 dest.sin_port = htons(DHCPV4_CLIENT_PORT);
872 
873                 memcpy(arp.arp_ha.sa_data, req->chaddr, 6);
874                 memcpy(&arp.arp_pa, &dest, sizeof(arp.arp_pa));
875                 memcpy(arp.arp_dev, iface->ifname, sizeof(arp.arp_dev));
876 
877                 if (ioctl(sock, SIOCSARP, &arp) < 0)
878                         syslog(LOG_ERR, "ioctl(SIOCSARP): %m");
879         }
880 
881         if (sendto(sock, &reply, PACKET_SIZE(&reply, cookie), MSG_DONTWAIT,
882                         (struct sockaddr*)&dest, sizeof(dest)) < 0)
883                 syslog(LOG_ERR, "Failed to send %s to %s - %s: %m",
884                         dhcpv4_msg_to_string(msg),
885                         dest.sin_addr.s_addr == INADDR_BROADCAST ?
886                         "ff:ff:ff:ff:ff:ff": odhcpd_print_mac(req->chaddr, req->hlen),
887                         inet_ntoa(dest.sin_addr));
888         else
889                 syslog(LOG_DEBUG, "Sent %s to %s - %s",
890                         dhcpv4_msg_to_string(msg),
891                         dest.sin_addr.s_addr == INADDR_BROADCAST ?
892                         "ff:ff:ff:ff:ff:ff": odhcpd_print_mac(req->chaddr, req->hlen),
893                         inet_ntoa(dest.sin_addr));
894 
895 
896 #ifdef WITH_UBUS
897         if (msg == DHCPV4_MSG_ACK)
898                 ubus_bcast_dhcp_event("dhcp.ack", req->chaddr, req->hlen, &reply.yiaddr,
899                                         hostname, iface->ifname);
900 #endif
901 }
902 
903 static bool dhcpv4_insert_assignment(struct list_head *list, struct dhcp_assignment *a,
904                                      uint32_t addr)
905 {
906         uint32_t h_addr = ntohl(addr);
907         struct dhcp_assignment *c;
908 
909         list_for_each_entry(c, list, head) {
910                 uint32_t c_addr = ntohl(c->addr);
911 
912                 if (c_addr == h_addr)
913                         return false;
914 
915                 if (c_addr > h_addr)
916                         break;
917         }
918 
919         /* Insert new node before c (might match list head) */
920         a->addr = addr;
921         list_add_tail(&a->head, &c->head);
922 
923         return true;
924 }
925 
926 static char* ip4toa(uint32_t addr)
927 {
928         static char buf[16];
929 
930         snprintf(buf, sizeof(buf), "%u.%u.%u.%u",
931                 ((uint8_t *)&addr)[0], ((uint8_t *)&addr)[1],
932                 ((uint8_t *)&addr)[2], ((uint8_t *)&addr)[3]);
933 
934         return buf;
935 }
936 
937 static bool dhcpv4_assign(struct interface *iface, struct dhcp_assignment *a,
938                           uint32_t raddr)
939 {
940         uint32_t start = ntohl(iface->dhcpv4_start_ip.s_addr);
941         uint32_t end = ntohl(iface->dhcpv4_end_ip.s_addr);
942         uint32_t count = end - start + 1;
943         uint32_t seed = 0;
944         bool assigned;
945 
946         /* Preconfigured IP address by static lease */
947         if (a->addr) {
948                 assigned = dhcpv4_insert_assignment(&iface->dhcpv4_assignments,
949                                                     a, a->addr);
950 
951                 if (assigned)
952                         syslog(LOG_DEBUG, "Assigning static IP: %s", ip4toa(a->addr));
953 
954                 return assigned;
955         }
956 
957         /* try to assign the IP the client asked for */
958         if (start <= ntohl(raddr) && ntohl(raddr) <= end &&
959             !config_find_lease_by_ipaddr(raddr)) {
960                 assigned = dhcpv4_insert_assignment(&iface->dhcpv4_assignments,
961                                                     a, raddr);
962 
963                 if (assigned) {
964                         syslog(LOG_DEBUG, "Assigning the IP the client asked for: %s",
965                                ip4toa(a->addr));
966 
967                         return true;
968                 }
969         }
970 
971         /* Seed RNG with checksum of hwaddress */
972         for (size_t i = 0; i < sizeof(a->hwaddr); ++i) {
973                 /* Knuth's multiplicative method */
974                 uint8_t o = a->hwaddr[i];
975                 seed += (o*2654435761) % UINT32_MAX;
976         }
977 
978         srand(seed);
979 
980         for (uint32_t i = 0, try = (((uint32_t)rand()) % count) + start; i < count;
981              ++i, try = (((try - start) + 1) % count) + start) {
982                 uint32_t n_try = htonl(try);
983 
984                 if (config_find_lease_by_ipaddr(n_try))
985                         continue;
986 
987                 assigned = dhcpv4_insert_assignment(&iface->dhcpv4_assignments,
988                                                     a, n_try);
989 
990                 if (assigned) {
991                         syslog(LOG_DEBUG, "Assigning mapped IP: %s (try %u of %u)",
992                                ip4toa(a->addr), i + 1, count);
993 
994                         return true;
995                 }
996         }
997 
998         syslog(LOG_NOTICE, "Can't assign any IP address -> address space is full");
999 
1000         return false;
1001 }
1002 
1003 
1004 static struct dhcp_assignment*
1005 dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
1006              const uint32_t reqaddr, uint32_t *leasetime, const char *hostname,
1007              const size_t hostname_len, const bool accept_fr_nonce, bool *incl_fr_opt,
1008              uint32_t *fr_serverid, const char* reqopts, const size_t reqopts_len)
1009 {
1010         struct dhcp_assignment *a = find_assignment_by_hwaddr(iface, mac);
1011         struct lease *l = config_find_lease_by_mac(mac);
1012         time_t now = odhcpd_time();
1013 
1014         if (l && a && a->lease != l) {
1015                 free_assignment(a);
1016                 a = NULL;
1017         }
1018 
1019         if (a && (a->flags & OAF_BOUND) && a->fr_ip) {
1020                 *fr_serverid = a->fr_ip->addr.addr.in.s_addr;
1021                 dhcpv4_fr_stop(a);
1022         }
1023 
1024         if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) {
1025                 bool assigned = !!a;
1026 
1027                 if (!a) {
1028                         if (!iface->no_dynamic_dhcp || l) {
1029                                 /* Create new binding */
1030                                 a = alloc_assignment(0);
1031                                 if (!a) {
1032                                         syslog(LOG_WARNING, "Failed to alloc assignment on interface %s",
1033                                                             iface->ifname);
1034                                         return NULL;
1035                                 }
1036                                 memcpy(a->hwaddr, mac, sizeof(a->hwaddr));
1037                                 /* Set valid time to 0 for static lease indicating */
1038                                 /* infinite lifetime otherwise current time        */
1039                                 a->valid_until = l ? 0 : now;
1040                                 a->dhcp_free_cb = dhcpv4_free_assignment;
1041                                 a->iface = iface;
1042                                 a->flags = OAF_DHCPV4;
1043                                 a->addr = l ? l->ipaddr : INADDR_ANY;
1044 
1045                                 assigned = dhcpv4_assign(iface, a, reqaddr);
1046 
1047                                 if (l) {
1048                                         a->flags |= OAF_STATIC;
1049 
1050                                         if (l->hostname)
1051                                                 a->hostname = strdup(l->hostname);
1052 
1053                                         if (l->leasetime)
1054                                                 a->leasetime = l->leasetime;
1055 
1056                                         list_add(&a->lease_list, &l->assignments);
1057                                         a->lease = l;
1058                                 }
1059                         }
1060                 } else if (((a->addr & iface->dhcpv4_mask.s_addr) !=
1061                             (iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr)) &&
1062                             !(a->flags & OAF_STATIC)) {
1063                         list_del_init(&a->head);
1064                         a->addr = INADDR_ANY;
1065 
1066                         assigned = dhcpv4_assign(iface, a, reqaddr);
1067                 }
1068 
1069                 if (assigned) {
1070                         uint32_t my_leasetime;
1071 
1072                         if (a->leasetime)
1073                                 my_leasetime = a->leasetime;
1074                         else
1075                                 my_leasetime = iface->dhcp_leasetime;
1076 
1077                         if ((*leasetime == 0) || (my_leasetime < *leasetime))
1078                                 *leasetime = my_leasetime;
1079 
1080                         if (msg == DHCPV4_MSG_DISCOVER) {
1081                                 a->flags &= ~OAF_BOUND;
1082 
1083                                 *incl_fr_opt = accept_fr_nonce;
1084                                 a->valid_until = now;
1085                         } else {
1086                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1087                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1088                                         if (a->hostname) {
1089                                                 memcpy(a->hostname, hostname, hostname_len);
1090                                                 a->hostname[hostname_len] = 0;
1091 
1092                                                 if (odhcpd_valid_hostname(a->hostname))
1093                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1094                                                 else
1095                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1096                                         }
1097                                 }
1098 
1099                                 if (reqopts_len > 0) {
1100                                         a->reqopts = realloc(a->reqopts, reqopts_len + 1);
1101                                         if (a->reqopts) {
1102                                                 memcpy(a->reqopts, reqopts, reqopts_len);
1103                                                 a->reqopts[reqopts_len] = 0;
1104                                         }
1105                                 }
1106 
1107                                 if (!(a->flags & OAF_BOUND)) {
1108                                         a->accept_fr_nonce = accept_fr_nonce;
1109                                         *incl_fr_opt = accept_fr_nonce;
1110                                         odhcpd_urandom(a->key, sizeof(a->key));
1111                                         a->flags |= OAF_BOUND;
1112                                 } else
1113                                         *incl_fr_opt = false;
1114 
1115                                 a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime));
1116                         }
1117                 } else if (!assigned && a) {
1118                         /* Cleanup failed assignment */
1119                         free_assignment(a);
1120                         a = NULL;
1121                 }
1122 
1123         } else if (msg == DHCPV4_MSG_RELEASE && a) {
1124                 a->flags &= ~OAF_BOUND;
1125                 a->valid_until = now - 1;
1126 
1127         } else if (msg == DHCPV4_MSG_DECLINE && a) {
1128                 a->flags &= ~OAF_BOUND;
1129 
1130                 if (!(a->flags & OAF_STATIC) || a->lease->ipaddr != a->addr) {
1131                         memset(a->hwaddr, 0, sizeof(a->hwaddr));
1132                         a->valid_until = now + 3600; /* Block address for 1h */
1133                 } else
1134                         a->valid_until = now - 1;
1135         }
1136 
1137         dhcpv6_ia_write_statefile();
1138 
1139         return a;
1140 }
1141 

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