2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
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.
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.
25 #include <net/if_arp.h>
26 #include <netinet/ip.h>
27 #include <sys/ioctl.h>
28 #include <sys/timerfd.h>
29 #include <arpa/inet.h>
36 static void handle_dhcpv4(void *addr
, void *data
, size_t len
,
37 struct interface
*iface
, void *dest_addr
);
38 static struct dhcpv4_assignment
* dhcpv4_lease(struct interface
*iface
,
39 enum dhcpv4_msg msg
, const uint8_t *mac
, struct in_addr reqaddr
,
40 const char *hostname
);
42 // Create socket and register events
48 char *dhcpv4_msg_to_string(uint8_t reqmsg
)
51 case (DHCPV4_MSG_DISCOVER
):
52 return "DHCPV4_MSG_DISCOVER";
53 case (DHCPV4_MSG_OFFER
):
54 return "DHCPV4_MSG_OFFER";
55 case (DHCPV4_MSG_REQUEST
):
56 return "DHCPV4_MSG_REQUEST";
57 case (DHCPV4_MSG_DECLINE
):
58 return "DHCPV4_MSG_DECLINE";
59 case (DHCPV4_MSG_ACK
):
60 return "DHCPV4_MSG_ACK";
61 case (DHCPV4_MSG_NAK
):
62 return "DHCPV4_MSG_NAK";
63 case (DHCPV4_MSG_RELEASE
):
64 return "DHCPV4_MSG_RELEASE";
65 case (DHCPV4_MSG_INFORM
):
66 return "DHCPV4_MSG_INFORM";
72 int setup_dhcpv4_interface(struct interface
*iface
, bool enable
)
74 if (iface
->dhcpv4_event
.uloop
.fd
> 0) {
75 uloop_fd_delete(&iface
->dhcpv4_event
.uloop
);
76 close(iface
->dhcpv4_event
.uloop
.fd
);
77 iface
->dhcpv4_event
.uloop
.fd
= -1;
80 if (iface
->dhcpv4
&& enable
) {
81 if (!iface
->dhcpv4_assignments
.next
)
82 INIT_LIST_HEAD(&iface
->dhcpv4_assignments
);
84 int sock
= socket(AF_INET
, SOCK_DGRAM
| SOCK_CLOEXEC
, IPPROTO_UDP
);
86 syslog(LOG_ERR
, "Failed to create DHCPv4 server socket: %s",
91 // Basic IPv6 configuration
93 setsockopt(sock
, SOL_SOCKET
, SO_REUSEADDR
, &val
, sizeof(val
));
94 setsockopt(sock
, SOL_SOCKET
, SO_BROADCAST
, &val
, sizeof(val
));
95 setsockopt(sock
, IPPROTO_IP
, IP_PKTINFO
, &val
, sizeof(val
));
97 val
= IPTOS_PREC_INTERNETCONTROL
;
98 setsockopt(sock
, IPPROTO_IP
, IP_TOS
, &val
, sizeof(val
));
100 val
= IP_PMTUDISC_DONT
;
101 setsockopt(sock
, IPPROTO_IP
, IP_MTU_DISCOVER
, &val
, sizeof(val
));
103 setsockopt(sock
, SOL_SOCKET
, SO_BINDTODEVICE
,
104 iface
->ifname
, strlen(iface
->ifname
));
106 struct sockaddr_in bind_addr
= {AF_INET
, htons(DHCPV4_SERVER_PORT
),
109 if (bind(sock
, (struct sockaddr
*)&bind_addr
, sizeof(bind_addr
))) {
110 syslog(LOG_ERR
, "Failed to open DHCPv4 server socket: %s",
116 if (ntohl(iface
->dhcpv4_start
.s_addr
) > ntohl(iface
->dhcpv4_end
.s_addr
)) {
117 syslog(LOG_ERR
, "Invalid DHCP range");
121 // Create a range if not specified
123 strncpy(ifreq
.ifr_name
, iface
->ifname
, sizeof(ifreq
.ifr_name
));
125 struct sockaddr_in
*saddr
= (struct sockaddr_in
*)&ifreq
.ifr_addr
;
126 struct sockaddr_in
*smask
= (struct sockaddr_in
*)&ifreq
.ifr_netmask
;
127 if (!(iface
->dhcpv4_start
.s_addr
& htonl(0xffff0000)) &&
128 !(iface
->dhcpv4_end
.s_addr
& htonl(0xffff0000)) &&
129 !ioctl(sock
, SIOCGIFADDR
, &ifreq
)) {
130 struct in_addr addr
= saddr
->sin_addr
;
132 ioctl(sock
, SIOCGIFNETMASK
, &ifreq
);
133 struct in_addr mask
= smask
->sin_addr
;
135 uint32_t start
= ntohl(iface
->dhcpv4_start
.s_addr
);
136 uint32_t end
= ntohl(iface
->dhcpv4_end
.s_addr
);
138 if (start
&& end
&& start
< end
&&
139 start
> ntohl(addr
.s_addr
& ~mask
.s_addr
) &&
140 (start
& ntohl(mask
.s_addr
)) == start
&&
141 (end
& ntohl(mask
.s_addr
)) == end
) {
142 iface
->dhcpv4_start
.s_addr
= htonl(start
) |
143 (addr
.s_addr
& mask
.s_addr
);
144 iface
->dhcpv4_end
.s_addr
= htonl(end
) |
145 (addr
.s_addr
& mask
.s_addr
);
146 } else if (ntohl(mask
.s_addr
) <= 0xfffffff0) {
147 start
= addr
.s_addr
& mask
.s_addr
;
148 end
= addr
.s_addr
& mask
.s_addr
;
150 if (ntohl(mask
.s_addr
) <= 0xffffff00) {
151 iface
->dhcpv4_start
.s_addr
= start
| htonl(100);
152 iface
->dhcpv4_end
.s_addr
= end
| htonl(250);
153 } else if (ntohl(mask
.s_addr
) <= 0xffffffc0) {
154 iface
->dhcpv4_start
.s_addr
= start
| htonl(10);
155 iface
->dhcpv4_end
.s_addr
= end
| htonl(60);
156 } else if (ntohl(mask
.s_addr
) <= 0xffffffe0) {
157 iface
->dhcpv4_start
.s_addr
= start
| htonl(10);
158 iface
->dhcpv4_end
.s_addr
= end
| htonl(30);
160 iface
->dhcpv4_start
.s_addr
= start
| htonl(3);
161 iface
->dhcpv4_end
.s_addr
= end
| htonl(12);
168 // Parse static entries
170 list_for_each_entry(lease
, &leases
, head
) {
172 size_t hostlen
= strlen(lease
->hostname
) + 1;
173 struct dhcpv4_assignment
*a
= calloc(1, sizeof(*a
) + hostlen
);
175 syslog(LOG_ERR
, "Calloc failed for static lease on interface %s",
179 a
->addr
= ntohl(lease
->ipaddr
.s_addr
);
180 memcpy(a
->hwaddr
, lease
->mac
.ether_addr_octet
, sizeof(a
->hwaddr
));
181 memcpy(a
->hostname
, lease
->hostname
, hostlen
);
182 a
->valid_until
= LONG_MAX
;
184 // Assign to all interfaces
185 struct dhcpv4_assignment
*c
;
186 list_for_each_entry(c
, &iface
->dhcpv4_assignments
, head
) {
187 if (c
->addr
> a
->addr
) {
188 list_add_tail(&a
->head
, &c
->head
);
190 } else if (c
->addr
== a
->addr
) {
191 // Already an assignment with that number
195 if (&c
->head
== &iface
->dhcpv4_assignments
) {
196 list_add(&a
->head
, &iface
->dhcpv4_assignments
);
203 // Clean invalid assignments
204 struct dhcpv4_assignment
*a
, *n
;
205 list_for_each_entry_safe(a
, n
, &iface
->dhcpv4_assignments
, head
) {
206 if ((htonl(a
->addr
) & smask
->sin_addr
.s_addr
) !=
207 (iface
->dhcpv4_start
.s_addr
& smask
->sin_addr
.s_addr
)) {
214 if (iface
->dhcpv4_leasetime
< 60)
215 iface
->dhcpv4_leasetime
= 43200;
217 iface
->dhcpv4_event
.uloop
.fd
= sock
;
218 iface
->dhcpv4_event
.handle_dgram
= handle_dhcpv4
;
219 odhcpd_register(&iface
->dhcpv4_event
);
220 } else if (iface
->dhcpv4_assignments
.next
) {
221 while (!list_empty(&iface
->dhcpv4_assignments
)) {
222 struct dhcpv4_assignment
*a
= list_first_entry(&iface
->dhcpv4_assignments
,
223 struct dhcpv4_assignment
, head
);
234 static void dhcpv4_put(struct dhcpv4_message
*msg
, uint8_t **cookie
,
235 uint8_t type
, uint8_t len
, const void *data
)
237 uint8_t *c
= *cookie
;
238 if (*cookie
+ 2 + len
> (uint8_t*)&msg
[1])
243 memcpy(c
, data
, len
);
249 // Simple DHCPv6-server for information requests
250 static void handle_dhcpv4(void *addr
, void *data
, size_t len
,
251 struct interface
*iface
, _unused
void *dest_addr
)
256 struct dhcpv4_message
*req
= data
;
257 if (len
< offsetof(struct dhcpv4_message
, options
) + 4 ||
258 req
->op
!= DHCPV4_BOOTREQUEST
|| req
->hlen
!= 6)
261 int sock
= iface
->dhcpv4_event
.uloop
.fd
;
262 struct sockaddr_in ifaddr
;
263 struct sockaddr_in ifnetmask
;
265 syslog(LOG_NOTICE
, "Got DHCPv4 request");
268 memcpy(ifreq
.ifr_name
, iface
->ifname
, sizeof(ifreq
.ifr_name
));
269 if (ioctl(sock
, SIOCGIFADDR
, &ifreq
)) {
270 syslog(LOG_WARNING
, "DHCPv4 failed to detect address: %s", strerror(errno
));
274 memcpy(&ifaddr
, &ifreq
.ifr_addr
, sizeof(ifaddr
));
275 if (ioctl(sock
, SIOCGIFNETMASK
, &ifreq
))
278 memcpy(&ifnetmask
, &ifreq
.ifr_netmask
, sizeof(ifnetmask
));
279 uint32_t network
= ifaddr
.sin_addr
.s_addr
& ifnetmask
.sin_addr
.s_addr
;
281 if ((iface
->dhcpv4_start
.s_addr
& ifnetmask
.sin_addr
.s_addr
) != network
||
282 (iface
->dhcpv4_end
.s_addr
& ifnetmask
.sin_addr
.s_addr
) != network
) {
283 syslog(LOG_WARNING
, "DHCPv4 range out of assigned network");
287 struct ifreq ifr
= {.ifr_name
= ""};
288 strncpy(ifr
.ifr_name
, iface
->ifname
, sizeof(ifr
.ifr_name
));
290 struct dhcpv4_message reply
= {
291 .op
= DHCPV4_BOOTREPLY
,
298 .ciaddr
= {INADDR_ANY
},
299 .giaddr
= req
->giaddr
,
300 .siaddr
= ifaddr
.sin_addr
,
302 memcpy(reply
.chaddr
, req
->chaddr
, sizeof(reply
.chaddr
));
304 reply
.options
[0] = 0x63;
305 reply
.options
[1] = 0x82;
306 reply
.options
[2] = 0x53;
307 reply
.options
[3] = 0x63;
309 uint8_t *cookie
= &reply
.options
[4];
310 uint8_t reqmsg
= DHCPV4_MSG_REQUEST
;
311 uint8_t msg
= DHCPV4_MSG_ACK
;
313 struct in_addr reqaddr
= {INADDR_ANY
};
317 uint8_t *start
= &req
->options
[4];
318 uint8_t *end
= ((uint8_t*)data
) + len
;
319 struct dhcpv4_option
*opt
;
320 dhcpv4_for_each_option(start
, end
, opt
) {
321 if (opt
->type
== DHCPV4_OPT_MESSAGE
&& opt
->len
== 1) {
322 reqmsg
= opt
->data
[0];
323 } else if (opt
->type
== DHCPV4_OPT_HOSTNAME
&& opt
->len
> 0) {
324 memcpy(hostname
, opt
->data
, opt
->len
);
325 hostname
[opt
->len
] = 0;
326 } else if (opt
->type
== DHCPV4_OPT_IPADDRESS
&& opt
->len
== 4) {
327 memcpy(&reqaddr
, opt
->data
, 4);
328 } else if (opt
->type
== DHCPV4_OPT_SERVERID
&& opt
->len
== 4) {
329 if (memcmp(opt
->data
, &ifaddr
.sin_addr
, 4))
331 } else if (iface
->filter_class
&& opt
->type
== DHCPV4_OPT_USER_CLASS
) {
332 uint8_t *c
= opt
->data
, *cend
= &opt
->data
[opt
->len
];
333 for (; c
< cend
&& &c
[*c
] < cend
; c
= &c
[1 + *c
]) {
334 size_t elen
= strlen(iface
->filter_class
);
335 if (*c
== elen
&& !memcmp(&c
[1], iface
->filter_class
, elen
))
336 return; // Ignore from homenet
341 if (reqmsg
!= DHCPV4_MSG_DISCOVER
&& reqmsg
!= DHCPV4_MSG_REQUEST
&&
342 reqmsg
!= DHCPV4_MSG_INFORM
&& reqmsg
!= DHCPV4_MSG_DECLINE
&&
343 reqmsg
!= DHCPV4_MSG_RELEASE
)
346 struct dhcpv4_assignment
*lease
= NULL
;
347 if (reqmsg
!= DHCPV4_MSG_INFORM
)
348 lease
= dhcpv4_lease(iface
, reqmsg
, req
->chaddr
, reqaddr
, hostname
);
351 if (reqmsg
== DHCPV4_MSG_REQUEST
)
352 msg
= DHCPV4_MSG_NAK
;
353 else if (reqmsg
== DHCPV4_MSG_DISCOVER
)
355 } else if (reqmsg
== DHCPV4_MSG_DISCOVER
) {
356 msg
= DHCPV4_MSG_OFFER
;
357 } else if (reqmsg
== DHCPV4_MSG_REQUEST
&& reqaddr
.s_addr
&&
358 reqaddr
.s_addr
!= htonl(lease
->addr
)) {
359 msg
= DHCPV4_MSG_NAK
;
361 * DHCP client requested an IP which we can't offer to him. Probably the
362 * client changed the network. The reply type is set to DHCPV4_MSG_NAK,
363 * because the client should not use that IP.
365 * For modern devices we build an answer that includes a valid IP, like
366 * a DHCPV4_MSG_ACK. The client will use that IP and doesn't need to
367 * perform additional DHCP round trips.
372 syslog(LOG_WARNING
, "received %s from %x:%x:%x:%x:%x:%x",
373 dhcpv4_msg_to_string(reqmsg
),
374 req
->chaddr
[0],req
->chaddr
[1],req
->chaddr
[2],
375 req
->chaddr
[3],req
->chaddr
[4],req
->chaddr
[5]);
377 if (reqmsg
== DHCPV4_MSG_DECLINE
|| reqmsg
== DHCPV4_MSG_RELEASE
)
380 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_MESSAGE
, 1, &msg
);
381 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_SERVERID
, 4, &ifaddr
.sin_addr
);
384 reply
.yiaddr
.s_addr
= htonl(lease
->addr
);
386 uint32_t val
= htonl(iface
->dhcpv4_leasetime
);
387 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_LEASETIME
, 4, &val
);
389 val
= htonl(500 * iface
->dhcpv4_leasetime
/ 1000);
390 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_RENEW
, 4, &val
);
392 val
= htonl(875 * iface
->dhcpv4_leasetime
/ 1000);
393 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_REBIND
, 4, &val
);
395 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_NETMASK
, 4, &ifnetmask
.sin_addr
);
397 if (lease
->hostname
[0])
398 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_HOSTNAME
,
399 strlen(lease
->hostname
), lease
->hostname
);
401 if (!ioctl(sock
, SIOCGIFBRDADDR
, &ifr
)) {
402 struct sockaddr_in
*ina
= (struct sockaddr_in
*)&ifr
.ifr_broadaddr
;
403 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_BROADCAST
, 4, &ina
->sin_addr
);
407 if (!ioctl(sock
, SIOCGIFMTU
, &ifr
)) {
408 uint16_t mtu
= htons(ifr
.ifr_mtu
);
409 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_MTU
, 2, &mtu
);
412 if (iface
->search
&& iface
->search_len
<= 255) {
413 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_SEARCH_DOMAIN
,
414 iface
->search_len
, iface
->search
);
415 } else if (!res_init() && _res
.dnsrch
[0] && _res
.dnsrch
[0][0]) {
416 uint8_t search_buf
[256];
417 int len
= dn_comp(_res
.dnsrch
[0], search_buf
,
418 sizeof(search_buf
), NULL
, NULL
);
420 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_SEARCH_DOMAIN
,
424 if (iface
->dhcpv4_router_cnt
== 0)
425 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_ROUTER
, 4, &ifaddr
.sin_addr
);
427 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_ROUTER
,
428 4 * iface
->dhcpv4_router_cnt
, iface
->dhcpv4_router
);
431 if (iface
->dhcpv4_dns_cnt
== 0)
432 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_DNSSERVER
, 4, &ifaddr
.sin_addr
);
434 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_DNSSERVER
,
435 4 * iface
->dhcpv4_dns_cnt
, iface
->dhcpv4_dns
);
438 dhcpv4_put(&reply
, &cookie
, DHCPV4_OPT_END
, 0, NULL
);
440 struct sockaddr_in dest
= *((struct sockaddr_in
*)addr
);
441 if (req
->giaddr
.s_addr
) {
443 * relay agent is configured, send reply to the agent
445 dest
.sin_addr
= req
->giaddr
;
446 dest
.sin_port
= htons(DHCPV4_SERVER_PORT
);
447 } else if (req
->ciaddr
.s_addr
&& req
->ciaddr
.s_addr
!= dest
.sin_addr
.s_addr
) {
449 * client has existing configuration (ciaddr is set) AND this address is
450 * not the address it used for the dhcp message
452 dest
.sin_addr
= req
->ciaddr
;
453 dest
.sin_port
= htons(DHCPV4_CLIENT_PORT
);
454 } else if ((ntohs(req
->flags
) & DHCPV4_FLAG_BROADCAST
) ||
455 req
->hlen
!= reply
.hlen
|| !reply
.yiaddr
.s_addr
) {
457 * client requests a broadcast reply OR we can't offer an IP
459 dest
.sin_addr
.s_addr
= INADDR_BROADCAST
;
460 dest
.sin_port
= htons(DHCPV4_CLIENT_PORT
);
463 * send reply to the newly (in this proccess) allocated IP
465 dest
.sin_addr
= reply
.yiaddr
;
466 dest
.sin_port
= htons(DHCPV4_CLIENT_PORT
);
468 struct arpreq arp
= {.arp_flags
= ATF_COM
};
469 memcpy(arp
.arp_ha
.sa_data
, req
->chaddr
, 6);
470 memcpy(&arp
.arp_pa
, &dest
, sizeof(arp
.arp_pa
));
471 memcpy(arp
.arp_dev
, iface
->ifname
, sizeof(arp
.arp_dev
));
472 ioctl(sock
, SIOCSARP
, &arp
);
475 syslog(LOG_WARNING
, "sending %s to %x:%x:%x:%x:%x:%x",
476 dhcpv4_msg_to_string(msg
),
477 req
->chaddr
[0],req
->chaddr
[1],req
->chaddr
[2],
478 req
->chaddr
[3],req
->chaddr
[4],req
->chaddr
[5]);
480 sendto(sock
, &reply
, sizeof(reply
), MSG_DONTWAIT
,
481 (struct sockaddr
*)&dest
, sizeof(dest
));
485 static bool dhcpv4_assign(struct interface
*iface
,
486 struct dhcpv4_assignment
*assign
, uint32_t raddr
)
488 const unsigned tries
= 10;
489 uint32_t start
= ntohl(iface
->dhcpv4_start
.s_addr
);
490 uint32_t end
= ntohl(iface
->dhcpv4_end
.s_addr
);
491 uint32_t count
= end
- start
+ 1;
493 // Seed RNG with checksum of DUID
495 for (size_t i
= 0; i
< sizeof(assign
->hwaddr
); ++i
)
496 seed
+= assign
->hwaddr
[i
];
499 // Try to assign up to 100x
500 for (unsigned i
= 0; i
< tries
; ++i
) {
501 uint32_t try = (((uint32_t)rand()) % count
) + start
;
502 if (i
== 0 && raddr
>= start
&& raddr
<= end
)
504 else if (i
== tries
- 1)
507 if (list_empty(&iface
->dhcpv4_assignments
)) {
509 list_add(&assign
->head
, &iface
->dhcpv4_assignments
);
513 struct dhcpv4_assignment
*c
;
514 list_for_each_entry(c
, &iface
->dhcpv4_assignments
, head
) {
517 list_add_tail(&assign
->head
, &c
->head
);
519 } else if (c
->addr
== try) {
532 static struct dhcpv4_assignment
* dhcpv4_lease(struct interface
*iface
,
533 enum dhcpv4_msg msg
, const uint8_t *mac
, struct in_addr reqaddr
,
534 const char *hostname
)
536 struct dhcpv4_assignment
*lease
= NULL
;
537 uint32_t raddr
= ntohl(reqaddr
.s_addr
);
538 time_t now
= odhcpd_time();
540 struct dhcpv4_assignment
*c
, *n
, *a
= NULL
;
541 list_for_each_entry_safe(c
, n
, &iface
->dhcpv4_assignments
, head
) {
542 if (!memcmp(c
->hwaddr
, mac
, 6)) {
544 if (c
->addr
== raddr
)
546 } else if (c
->valid_until
< now
) {
552 if (msg
== DHCPV4_MSG_DISCOVER
|| msg
== DHCPV4_MSG_REQUEST
) {
554 size_t hostlen
= strlen(hostname
) + 1;
556 if (!a
&& !iface
->no_dynamic_dhcp
) { // Create new binding
557 a
= calloc(1, sizeof(*a
) + hostlen
);
559 syslog(LOG_ERR
, "Failed to calloc binding on interface %s", iface
->ifname
);
562 memcpy(a
->hwaddr
, mac
, sizeof(a
->hwaddr
));
563 memcpy(a
->hostname
, hostname
, hostlen
);
565 assigned
= dhcpv4_assign(iface
, a
, raddr
);
568 if (assigned
&& !a
->hostname
[0] && hostname
) {
569 a
= realloc(a
, sizeof(*a
) + hostlen
);
571 syslog(LOG_ERR
, "Failed to realloc binding on interface %s", iface
->ifname
);
574 memcpy(a
->hostname
, hostname
, hostlen
);
577 a
->head
.next
->prev
= &a
->head
;
578 a
->head
.prev
->next
= &a
->head
;
581 // Was only a solicitation: mark binding for removal
582 if (assigned
&& a
->valid_until
< now
) {
583 a
->valid_until
= (msg
== DHCPV4_MSG_DISCOVER
) ? 0 :
584 (now
+ iface
->dhcpv4_leasetime
);
585 } else if (!assigned
&& a
) { // Cleanup failed assignment
592 } else if (msg
== DHCPV4_MSG_RELEASE
) {
596 } else if (msg
== DHCPV4_MSG_DECLINE
) {
597 memset(a
->hwaddr
, 0, sizeof(a
->hwaddr
));
598 a
->valid_until
= now
+ 3600; // Block address for 1h
601 dhcpv6_write_statefile();