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.
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
32 #include <net/ethernet.h>
38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
39 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
40 #define DHCPV6_CLIENT_PORT 546
41 #define DHCPV6_SERVER_PORT 547
42 #define DHCPV6_DUID_LLADDR 3
43 #define DHCPV6_REQ_DELAY 1
46 static bool dhcpv6_response_is_valid(const void *buf
, ssize_t len
,
47 const uint8_t transaction
[3], enum dhcpv6_msg type
);
49 static uint32_t dhcpv6_parse_ia(void *opt
, void *end
);
51 static reply_handler dhcpv6_handle_reply
;
52 static reply_handler dhcpv6_handle_advert
;
53 static reply_handler dhcpv6_handle_rebind_reply
;
54 static reply_handler dhcpv6_handle_reconfigure
;
55 static int dhcpv6_commit_advert(void);
59 // RFC 3315 - 5.5 Timeout and Delay values
60 static struct dhcpv6_retx dhcpv6_retx
[_DHCPV6_MSG_MAX
] = {
61 [DHCPV6_MSG_UNKNOWN
] = {false, 1, 120, 0, "<POLL>",
62 dhcpv6_handle_reconfigure
, NULL
},
63 [DHCPV6_MSG_SOLICIT
] = {true, 1, 3600, 0, "SOLICIT",
64 dhcpv6_handle_advert
, dhcpv6_commit_advert
},
65 [DHCPV6_MSG_REQUEST
] = {true, 1, 30, 10, "REQUEST",
66 dhcpv6_handle_reply
, NULL
},
67 [DHCPV6_MSG_RENEW
] = {false, 10, 600, 0, "RENEW",
68 dhcpv6_handle_reply
, NULL
},
69 [DHCPV6_MSG_REBIND
] = {false, 10, 600, 0, "REBIND",
70 dhcpv6_handle_rebind_reply
, NULL
},
71 [DHCPV6_MSG_RELEASE
] = {false, 1, 0, 5, "RELEASE", NULL
, NULL
},
72 [DHCPV6_MSG_DECLINE
] = {false, 1, 0, 5, "DECLINE", NULL
, NULL
},
73 [DHCPV6_MSG_INFO_REQ
] = {true, 1, 120, 0, "INFOREQ",
74 dhcpv6_handle_reply
, NULL
},
80 static int ifindex
= -1;
81 static int64_t t1
= 0, t2
= 0, t3
= 0;
84 static int request_prefix
= -1;
85 static enum odhcp6c_ia_mode na_mode
= IA_MODE_NONE
, pd_mode
= IA_MODE_NONE
;
86 static bool accept_reconfig
= false;
89 static uint8_t reconf_key
[16];
93 int init_dhcpv6(const char *ifname
, int request_pd
, int sol_timeout
)
95 request_prefix
= request_pd
;
96 dhcpv6_retx
[DHCPV6_MSG_SOLICIT
].max_timeo
= sol_timeout
;
98 sock
= socket(AF_INET6
, SOCK_DGRAM
| SOCK_CLOEXEC
, IPPROTO_UDP
);
102 strncpy(ifr
.ifr_name
, ifname
, sizeof(ifr
.ifr_name
));
103 if (ioctl(sock
, SIOCGIFINDEX
, &ifr
))
105 ifindex
= ifr
.ifr_ifindex
;
107 // Create client DUID
108 size_t client_id_len
;
109 odhcp6c_get_state(STATE_CLIENT_ID
, &client_id_len
);
110 if (client_id_len
== 0) {
111 ioctl(sock
, SIOCGIFHWADDR
, &ifr
);
112 uint8_t duid
[14] = {0, DHCPV6_OPT_CLIENTID
, 0, 10, 0,
113 DHCPV6_DUID_LLADDR
, 0, 1};
114 memcpy(&duid
[8], ifr
.ifr_hwaddr
.sa_data
, ETHER_ADDR_LEN
);
116 uint8_t zero
[ETHER_ADDR_LEN
] = {0, 0, 0, 0, 0, 0};
117 struct ifreq ifs
[100], *ifp
, *ifend
;
120 ifc
.ifc_len
= sizeof(ifs
);
122 if (!memcmp(&duid
[8], zero
, ETHER_ADDR_LEN
) &&
123 ioctl(sock
, SIOCGIFCONF
, &ifc
) >= 0) {
124 // If our interface doesn't have an address...
125 ifend
= ifs
+ (ifc
.ifc_len
/ sizeof(struct ifreq
));
126 for (ifp
= ifc
.ifc_req
; ifp
< ifend
&&
127 !memcmp(&duid
[8], zero
, 6); ifp
++) {
128 memcpy(ifr
.ifr_name
, ifp
->ifr_name
,
129 sizeof(ifr
.ifr_name
));
130 ioctl(sock
, SIOCGIFHWADDR
, &ifr
);
131 memcpy(&duid
[8], ifr
.ifr_hwaddr
.sa_data
,
136 odhcp6c_add_state(STATE_CLIENT_ID
, duid
, sizeof(duid
));
141 htons(DHCPV6_OPT_SIP_SERVER_D
),
142 htons(DHCPV6_OPT_SIP_SERVER_A
),
143 htons(DHCPV6_OPT_DNS_SERVERS
),
144 htons(DHCPV6_OPT_DNS_DOMAIN
),
145 htons(DHCPV6_OPT_NTP_SERVER
),
146 htons(DHCPV6_OPT_SIP_SERVER_A
),
147 htons(DHCPV6_OPT_AFTR_NAME
),
148 htons(DHCPV6_OPT_PD_EXCLUDE
),
149 #ifdef EXT_PREFIX_CLASS
150 htons(DHCPV6_OPT_PREFIX_CLASS
),
153 odhcp6c_add_state(STATE_ORO
, oro
, sizeof(oro
));
156 // Configure IPv6-options
158 setsockopt(sock
, IPPROTO_IPV6
, IPV6_V6ONLY
, &val
, sizeof(val
));
159 setsockopt(sock
, SOL_SOCKET
, SO_REUSEADDR
, &val
, sizeof(val
));
161 setsockopt(sock
, IPPROTO_IPV6
, IPV6_MULTICAST_LOOP
, &val
, sizeof(val
));
162 setsockopt(sock
, SOL_SOCKET
, SO_BINDTODEVICE
, ifname
, strlen(ifname
));
164 struct sockaddr_in6 client_addr
= { .sin6_family
= AF_INET6
,
165 .sin6_port
= htons(DHCPV6_CLIENT_PORT
), .sin6_flowinfo
= 0 };
166 if (bind(sock
, (struct sockaddr
*)&client_addr
, sizeof(client_addr
)))
173 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na
, enum odhcp6c_ia_mode pd
)
180 static void dhcpv6_send(enum dhcpv6_msg type
, uint8_t trid
[3], uint32_t ecs
)
184 gethostname(fqdn_buf
, sizeof(fqdn_buf
));
191 size_t fqdn_len
= 5 + dn_comp(fqdn_buf
, fqdn
.data
,
192 sizeof(fqdn
.data
), NULL
, NULL
);
193 fqdn
.type
= htons(DHCPV6_OPT_FQDN
);
194 fqdn
.len
= htons(fqdn_len
- 4);
200 void *cl_id
= odhcp6c_get_state(STATE_CLIENT_ID
, &cl_id_len
);
204 void *srv_id
= odhcp6c_get_state(STATE_SERVER_ID
, &srv_id_len
);
207 size_t ia_pd_entries
, ia_pd_len
= 0;
208 struct odhcp6c_entry
*e
= odhcp6c_get_state(STATE_IA_PD
, &ia_pd_entries
);
209 ia_pd_entries
/= sizeof(*e
);
210 struct dhcpv6_ia_hdr hdr_ia_pd
= {
211 htons(DHCPV6_OPT_IA_PD
),
212 htons(sizeof(hdr_ia_pd
) - 4),
217 uint8_t *ia_pd
= alloca(ia_pd_entries
* (sizeof(struct dhcpv6_ia_prefix
) + 10));
218 for (size_t i
= 0; i
< ia_pd_entries
; ++i
) {
220 if (e
[i
].priority
> 0)
221 ex_len
= ((e
[i
].priority
- e
[i
].length
- 1) / 8) + 6;
223 struct dhcpv6_ia_prefix p
= {
224 .type
= htons(DHCPV6_OPT_IA_PREFIX
),
225 .len
= htons(sizeof(p
) - 4U + ex_len
),
226 .prefix
= e
[i
].length
,
230 memcpy(ia_pd
+ ia_pd_len
, &p
, sizeof(p
));
231 ia_pd_len
+= sizeof(p
);
234 ia_pd
[ia_pd_len
++] = 0;
235 ia_pd
[ia_pd_len
++] = DHCPV6_OPT_PD_EXCLUDE
;
236 ia_pd
[ia_pd_len
++] = 0;
237 ia_pd
[ia_pd_len
++] = ex_len
- 4;
238 ia_pd
[ia_pd_len
++] = e
[i
].priority
;
240 uint32_t excl
= ntohl(e
[i
].router
.s6_addr32
[1]);
241 excl
>>= (64 - e
[i
].priority
);
242 excl
<<= 8 - ((e
[i
].priority
- e
[i
].length
) % 8);
244 for (size_t i
= ex_len
- 5; i
> 0; --i
, excl
>>= 8)
245 ia_pd
[ia_pd_len
+ i
] = excl
& 0xff;
246 ia_pd_len
+= ex_len
- 5;
250 struct dhcpv6_ia_prefix pref
= {
251 .type
= htons(DHCPV6_OPT_IA_PREFIX
),
252 .len
= htons(25), .prefix
= request_prefix
254 if (request_prefix
> 0 && ia_pd_len
== 0 && type
== DHCPV6_MSG_SOLICIT
) {
255 ia_pd
= (uint8_t*)&pref
;
256 ia_pd_len
= sizeof(pref
);
258 hdr_ia_pd
.len
= htons(ntohs(hdr_ia_pd
.len
) + ia_pd_len
);
261 size_t ia_na_entries
, ia_na_len
= 0;
263 e
= odhcp6c_get_state(STATE_IA_NA
, &ia_na_entries
);
264 ia_na_entries
/= sizeof(*e
);
266 struct dhcpv6_ia_hdr hdr_ia_na
= {
267 htons(DHCPV6_OPT_IA_NA
),
268 htons(sizeof(hdr_ia_na
) - 4),
272 struct dhcpv6_ia_addr pa
[ia_na_entries
];
273 for (size_t i
= 0; i
< ia_na_entries
; ++i
) {
274 pa
[i
].type
= htons(DHCPV6_OPT_IA_ADDR
);
275 pa
[i
].len
= htons(sizeof(pa
[i
]) - 4U);
276 pa
[i
].addr
= e
[i
].target
;
282 ia_na_len
= sizeof(pa
);
283 hdr_ia_na
.len
= htons(ntohs(hdr_ia_na
.len
) + ia_na_len
);
285 // Reconfigure Accept
289 } reconf_accept
= {htons(DHCPV6_OPT_RECONF_ACCEPT
), 0};
291 // Request Information Refresh
292 uint16_t oro_refresh
= htons(DHCPV6_OPT_INFO_REFRESH
);
296 void *oro
= odhcp6c_get_state(STATE_ORO
, &oro_len
);
300 uint16_t elapsed_type
;
301 uint16_t elapsed_len
;
302 uint16_t elapsed_value
;
306 type
, {trid
[0], trid
[1], trid
[2]},
307 htons(DHCPV6_OPT_ELAPSED
), htons(2),
308 htons((ecs
> 0xffff) ? 0xffff : ecs
),
309 htons(DHCPV6_OPT_ORO
), htons(oro_len
),
312 struct iovec iov
[] = {
317 {srv_id
, srv_id_len
},
318 {&reconf_accept
, sizeof(reconf_accept
)},
320 {&hdr_ia_na
, sizeof(hdr_ia_na
)},
322 {&hdr_ia_pd
, sizeof(hdr_ia_pd
)},
326 size_t cnt
= ARRAY_SIZE(iov
);
327 if (type
== DHCPV6_MSG_INFO_REQ
) {
329 iov
[2].iov_len
= sizeof(oro_refresh
);
330 hdr
.oro_len
= htons(oro_len
+ sizeof(oro_refresh
));
331 } else if (!request_prefix
) {
335 // Disable IAs if not used
336 if (type
!= DHCPV6_MSG_SOLICIT
) {
344 if (na_mode
== IA_MODE_NONE
)
347 struct sockaddr_in6 srv
= {AF_INET6
, htons(DHCPV6_SERVER_PORT
),
348 0, ALL_DHCPV6_RELAYS
, ifindex
};
349 struct msghdr msg
= {&srv
, sizeof(srv
), iov
, cnt
, NULL
, 0, 0};
351 sendmsg(sock
, &msg
, 0);
355 static int64_t dhcpv6_rand_delay(int64_t time
)
358 odhcp6c_random(&random
, sizeof(random
));
359 return (time
* ((int64_t)random
% 1000LL)) / 10000LL;
363 int dhcpv6_request(enum dhcpv6_msg type
)
365 uint8_t buf
[1536], rc
= 0;
366 uint64_t timeout
= UINT32_MAX
;
367 struct dhcpv6_retx
*retx
= &dhcpv6_retx
[type
];
370 struct timespec ts
= {0, 0};
371 ts
.tv_nsec
= dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY
);
372 nanosleep(&ts
, NULL
);
375 if (type
== DHCPV6_MSG_UNKNOWN
)
377 else if (type
== DHCPV6_MSG_RENEW
)
378 timeout
= (t2
> t1
) ? t2
- t1
: 0;
379 else if (type
== DHCPV6_MSG_REBIND
)
380 timeout
= (t3
> t2
) ? t3
- t2
: 0;
385 syslog(LOG_NOTICE
, "Starting %s transaction (timeout %llus, max rc %d)", retx
->name
, timeout
, retx
->max_rc
);
387 uint64_t start
= odhcp6c_get_milli_time(), round_start
= start
, elapsed
;
389 // Generate transaction ID
390 uint8_t trid
[3] = {0, 0, 0};
391 if (type
!= DHCPV6_MSG_UNKNOWN
)
392 odhcp6c_random(trid
, sizeof(trid
));
398 int64_t delay
= dhcpv6_rand_delay(retx
->init_timeo
* 1000);
400 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
401 while (type
== DHCPV6_MSG_SOLICIT
&& delay
<= 0)
402 delay
= dhcpv6_rand_delay(retx
->init_timeo
* 1000);
404 rto
= (retx
->init_timeo
* 1000 + delay
);
407 rto
= (2 * rto
+ dhcpv6_rand_delay(rto
));
409 if (retx
->max_timeo
&& (rto
>= retx
->max_timeo
* 1000))
410 rto
= retx
->max_timeo
* 1000 +
411 dhcpv6_rand_delay(retx
->max_timeo
* 1000);
413 // Calculate end for this round and elapsed time
414 uint64_t round_end
= round_start
+ rto
;
415 elapsed
= round_start
- start
;
417 // Don't wait too long
418 if (round_end
- start
> timeout
* 1000)
419 round_end
= timeout
* 1000 + start
;
421 // Built and send package
422 if (type
!= DHCPV6_MSG_UNKNOWN
) {
423 syslog(LOG_NOTICE
, "Send %s message (elapsed %llums, rc %d)", retx
->name
, elapsed
, rc
);
424 dhcpv6_send(type
, trid
, elapsed
/ 10);
429 for (; len
< 0 && round_start
< round_end
;
430 round_start
= odhcp6c_get_milli_time()) {
431 // Check for pending signal
432 if (odhcp6c_signal_process())
435 // Set timeout for receiving
436 uint64_t t
= round_end
- round_start
;
437 struct timeval timeout
= {t
/ 1000, (t
% 1000) * 1000};
438 setsockopt(sock
, SOL_SOCKET
, SO_RCVTIMEO
,
439 &timeout
, sizeof(timeout
));
442 len
= recv(sock
, buf
, sizeof(buf
), 0);
444 if (!dhcpv6_response_is_valid(buf
, len
, trid
, type
))
448 uint8_t *opt
= &buf
[4];
449 uint8_t *opt_end
= opt
+ len
- 4;
451 round_start
= odhcp6c_get_milli_time();
452 elapsed
= round_start
- start
;
453 syslog(LOG_NOTICE
, "Got a valid reply after "
456 if (retx
->handler_reply
)
457 len
= retx
->handler_reply(
458 type
, rc
, opt
, opt_end
);
460 if (len
> 0 && round_end
- round_start
> 1000)
461 round_end
= 1000 + round_start
;
466 if (retx
->handler_finish
)
467 len
= retx
->handler_finish();
468 } while (len
< 0 && ((elapsed
/ 1000 < timeout
) && (!retx
->max_rc
|| rc
< retx
->max_rc
)));
474 static bool dhcpv6_response_is_valid(const void *buf
, ssize_t len
,
475 const uint8_t transaction
[3], enum dhcpv6_msg type
)
477 const struct dhcpv6_header
*rep
= buf
;
478 if (len
< (ssize_t
)sizeof(*rep
) || memcmp(rep
->tr_id
,
479 transaction
, sizeof(rep
->tr_id
)))
480 return false; // Invalid reply
482 if (type
== DHCPV6_MSG_SOLICIT
) {
483 if (rep
->msg_type
!= DHCPV6_MSG_ADVERT
&&
484 rep
->msg_type
!= DHCPV6_MSG_REPLY
)
486 } else if (type
== DHCPV6_MSG_UNKNOWN
) {
487 if (!accept_reconfig
|| rep
->msg_type
!= DHCPV6_MSG_RECONF
)
489 } else if (rep
->msg_type
!= DHCPV6_MSG_REPLY
) {
493 uint8_t *end
= ((uint8_t*)buf
) + len
, *odata
;
494 uint16_t otype
, olen
;
495 bool clientid_ok
= false, serverid_ok
= false, rcauth_ok
= false;
497 size_t client_id_len
, server_id_len
;
498 void *client_id
= odhcp6c_get_state(STATE_CLIENT_ID
, &client_id_len
);
499 void *server_id
= odhcp6c_get_state(STATE_SERVER_ID
, &server_id_len
);
501 dhcpv6_for_each_option(&rep
[1], end
, otype
, olen
, odata
) {
502 if (otype
== DHCPV6_OPT_CLIENTID
) {
503 clientid_ok
= (olen
+ 4U == client_id_len
) && !memcmp(
504 &odata
[-4], client_id
, client_id_len
);
505 } else if (otype
== DHCPV6_OPT_SERVERID
) {
506 serverid_ok
= (olen
+ 4U == server_id_len
) && !memcmp(
507 &odata
[-4], server_id
, server_id_len
);
508 } else if (otype
== DHCPV6_OPT_AUTH
&& olen
== -4 +
509 sizeof(struct dhcpv6_auth_reconfigure
)) {
510 struct dhcpv6_auth_reconfigure
*r
= (void*)&odata
[-4];
511 if (r
->protocol
!= 3 || r
->algorithm
!= 1 || r
->reconf_type
!= 2)
515 uint8_t serverhash
[16], secretbytes
[16], hash
[16];
516 memcpy(serverhash
, r
->key
, sizeof(serverhash
));
517 memset(r
->key
, 0, sizeof(r
->key
));
518 memcpy(secretbytes
, reconf_key
, sizeof(secretbytes
));
520 for (size_t i
= 0; i
< sizeof(secretbytes
); ++i
)
521 secretbytes
[i
] ^= 0x36;
524 md5_append(&md5
, secretbytes
, sizeof(secretbytes
));
525 md5_append(&md5
, buf
, len
);
526 md5_finish(&md5
, hash
);
528 for (size_t i
= 0; i
< sizeof(secretbytes
); ++i
) {
529 secretbytes
[i
] ^= 0x36;
530 secretbytes
[i
] ^= 0x5c;
534 md5_append(&md5
, secretbytes
, sizeof(secretbytes
));
535 md5_append(&md5
, hash
, 16);
536 md5_finish(&md5
, hash
);
538 rcauth_ok
= !memcmp(hash
, serverhash
, sizeof(hash
));
542 if (rep
->msg_type
== DHCPV6_MSG_RECONF
&& !rcauth_ok
)
545 return clientid_ok
&& (serverid_ok
|| server_id_len
== 0);
549 int dhcpv6_poll_reconfigure(void)
551 int ret
= dhcpv6_request(DHCPV6_MSG_UNKNOWN
);
553 ret
= dhcpv6_request(ret
);
559 static int dhcpv6_handle_reconfigure(_unused
enum dhcpv6_msg orig
, const int rc
,
560 const void *opt
, const void *end
)
562 // TODO: should verify the reconfigure message
563 uint16_t otype
, olen
;
564 uint8_t *odata
, msg
= DHCPV6_MSG_RENEW
;
565 dhcpv6_for_each_option(opt
, end
, otype
, olen
, odata
)
566 if (otype
== DHCPV6_OPT_RECONF_MESSAGE
&& olen
== 1 && (
567 odata
[0] == DHCPV6_MSG_RENEW
||
568 odata
[0] == DHCPV6_MSG_INFO_REQ
))
571 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN
, rc
, NULL
, NULL
);
576 // Collect all advertised servers
577 static int dhcpv6_handle_advert(enum dhcpv6_msg orig
, _unused
const int rc
,
578 const void *opt
, const void *end
)
580 uint16_t olen
, otype
;
582 struct dhcpv6_server_cand cand
= {false, false, 0, 0, {0}, NULL
, NULL
, 0, 0};
583 bool have_na
= false;
586 dhcpv6_for_each_option(opt
, end
, otype
, olen
, odata
) {
587 if (orig
== DHCPV6_MSG_SOLICIT
&&
588 (otype
== DHCPV6_OPT_IA_PD
|| otype
== DHCPV6_OPT_IA_NA
) &&
589 olen
> sizeof(struct dhcpv6_ia_hdr
)) {
590 struct dhcpv6_ia_hdr
*ia_hdr
= (void*)(&odata
[-4]);
591 dhcpv6_parse_ia(&ia_hdr
[1], odata
+ olen
);
594 if (otype
== DHCPV6_OPT_SERVERID
&& olen
<= 130) {
595 memcpy(cand
.duid
, odata
, olen
);
596 cand
.duid_len
= olen
;
597 } else if (otype
== DHCPV6_OPT_STATUS
&& olen
>= 2 && !odata
[0]
598 && odata
[1] == DHCPV6_NoPrefixAvail
) {
599 cand
.preference
-= 2000;
600 } else if (otype
== DHCPV6_OPT_PREF
&& olen
>= 1 &&
601 cand
.preference
>= 0) {
602 cand
.preference
= odata
[0];
603 } else if (otype
== DHCPV6_OPT_RECONF_ACCEPT
) {
604 cand
.wants_reconfigure
= true;
605 } else if (otype
== DHCPV6_OPT_IA_PD
&& request_prefix
) {
606 struct dhcpv6_ia_hdr
*h
= (struct dhcpv6_ia_hdr
*)&odata
[-4];
607 uint8_t *oend
= odata
+ olen
, *d
;
608 dhcpv6_for_each_option(&h
[1], oend
, otype
, olen
, d
) {
609 if (otype
== DHCPV6_OPT_IA_PREFIX
&& (olen
+ 4) >=
610 (uint16_t)sizeof(struct dhcpv6_ia_prefix
)) {
611 struct dhcpv6_ia_prefix
*p
= (struct dhcpv6_ia_prefix
*)&d
[-4];
615 } else if (otype
== DHCPV6_OPT_IA_NA
) {
616 struct dhcpv6_ia_hdr
*h
= (struct dhcpv6_ia_hdr
*)&odata
[-4];
617 uint8_t *oend
= odata
+ olen
, *d
;
618 dhcpv6_for_each_option(&h
[1], oend
, otype
, olen
, d
)
619 if (otype
== DHCPV6_OPT_IA_ADDR
)
624 if ((!have_na
&& na_mode
== IA_MODE_FORCE
) ||
625 (!have_pd
&& pd_mode
== IA_MODE_FORCE
))
628 if (na_mode
!= IA_MODE_NONE
&& !have_na
) {
629 cand
.has_noaddravail
= true;
630 cand
.preference
-= 1000;
633 if (pd_mode
!= IA_MODE_NONE
) {
635 cand
.preference
+= 2000 + (128 - have_pd
);
637 cand
.preference
-= 2000;
640 if (cand
.duid_len
> 0) {
641 cand
.ia_na
= odhcp6c_move_state(STATE_IA_NA
, &cand
.ia_na_len
);
642 cand
.ia_pd
= odhcp6c_move_state(STATE_IA_PD
, &cand
.ia_pd_len
);
643 odhcp6c_add_state(STATE_SERVER_CAND
, &cand
, sizeof(cand
));
646 if (orig
== DHCPV6_MSG_SOLICIT
) {
647 odhcp6c_clear_state(STATE_IA_NA
);
648 odhcp6c_clear_state(STATE_IA_PD
);
655 static int dhcpv6_commit_advert(void)
658 struct dhcpv6_server_cand
*c
= NULL
, *cand
=
659 odhcp6c_get_state(STATE_SERVER_CAND
, &cand_len
);
662 for (size_t i
= 0; i
< cand_len
/ sizeof(*c
); ++i
) {
663 if (cand
[i
].has_noaddravail
)
664 retry
= true; // We want to try again
666 if (!c
|| c
->preference
< cand
[i
].preference
)
670 if (retry
&& na_mode
== IA_MODE_TRY
) {
671 // We give it a second try without the IA_NA
672 na_mode
= IA_MODE_NONE
;
673 return dhcpv6_request(DHCPV6_MSG_SOLICIT
);
677 uint16_t hdr
[2] = {htons(DHCPV6_OPT_SERVERID
),
679 odhcp6c_add_state(STATE_SERVER_ID
, hdr
, sizeof(hdr
));
680 odhcp6c_add_state(STATE_SERVER_ID
, c
->duid
, c
->duid_len
);
681 accept_reconfig
= c
->wants_reconfigure
;
682 odhcp6c_add_state(STATE_IA_NA
, c
->ia_na
, c
->ia_na_len
);
683 odhcp6c_add_state(STATE_IA_PD
, c
->ia_pd
, c
->ia_pd_len
);
686 for (size_t i
= 0; i
< cand_len
/ sizeof(*c
); ++i
) {
690 odhcp6c_clear_state(STATE_SERVER_CAND
);
694 else if (request_prefix
|| na_mode
!= IA_MODE_NONE
)
695 return DHCPV6_STATEFUL
;
697 return DHCPV6_STATELESS
;
701 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig
, const int rc
,
702 const void *opt
, const void *end
)
704 dhcpv6_handle_advert(orig
, rc
, opt
, end
);
705 if (dhcpv6_commit_advert() < 0) {
706 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN
, rc
, NULL
, NULL
);
710 return dhcpv6_handle_reply(orig
, rc
, opt
, end
);
714 static int dhcpv6_handle_reply(enum dhcpv6_msg orig
, _unused
const int rc
,
715 const void *opt
, const void *end
)
718 uint16_t otype
, olen
;
722 if (orig
== DHCPV6_MSG_UNKNOWN
) {
723 static time_t last_update
= 0;
724 time_t now
= odhcp6c_get_milli_time() / 1000;
726 uint32_t elapsed
= (last_update
> 0) ? now
- last_update
: 0;
742 t1
= t2
= t3
= UINT32_MAX
;
745 if (orig
== DHCPV6_MSG_REQUEST
) {
746 // Delete NA and PD we have in the state from the Advert
747 odhcp6c_clear_state(STATE_IA_NA
);
748 odhcp6c_clear_state(STATE_IA_PD
);
752 odhcp6c_clear_state(STATE_DNS
);
753 odhcp6c_clear_state(STATE_SEARCH
);
754 odhcp6c_clear_state(STATE_SNTP_IP
);
755 odhcp6c_clear_state(STATE_SNTP_FQDN
);
756 odhcp6c_clear_state(STATE_SIP_IP
);
757 odhcp6c_clear_state(STATE_SIP_FQDN
);
758 odhcp6c_clear_state(STATE_AFTR_NAME
);
761 // Parse and find all matching IAs
762 dhcpv6_for_each_option(opt
, end
, otype
, olen
, odata
) {
763 if ((otype
== DHCPV6_OPT_IA_PD
|| otype
== DHCPV6_OPT_IA_NA
)
764 && olen
> sizeof(struct dhcpv6_ia_hdr
)) {
765 struct dhcpv6_ia_hdr
*ia_hdr
= (void*)(&odata
[-4]);
766 uint32_t l_t1
= ntohl(ia_hdr
->t1
);
767 uint32_t l_t2
= ntohl(ia_hdr
->t2
);
769 // Test ID and T1-T2 validity
770 if (ia_hdr
->iaid
!= 1 || l_t2
< l_t1
)
774 uint16_t stype
, slen
;
776 // Test status and bail if error
777 dhcpv6_for_each_option(&ia_hdr
[1], odata
+ olen
,
779 if (stype
== DHCPV6_OPT_STATUS
&& slen
>= 2)
780 error
= ((int)sdata
[0]) << 8 | ((int)sdata
[1]);
783 syslog(LOG_WARNING
, "Server returned IAID status %i!", error
);
789 uint32_t n
= dhcpv6_parse_ia(&ia_hdr
[1], odata
+ olen
);
801 if (l_t1
> 0 && t1
> l_t1
)
804 if (l_t2
> 0 && t2
> l_t2
)
807 } else if (otype
== DHCPV6_OPT_DNS_SERVERS
) {
809 odhcp6c_add_state(STATE_DNS
, odata
, olen
);
810 } else if (otype
== DHCPV6_OPT_DNS_DOMAIN
) {
811 odhcp6c_add_state(STATE_SEARCH
, odata
, olen
);
812 } else if (otype
== DHCPV6_OPT_NTP_SERVER
) {
813 uint16_t stype
, slen
;
815 // Test status and bail if error
816 dhcpv6_for_each_option(odata
, odata
+ olen
,
817 stype
, slen
, sdata
) {
818 if (slen
== 16 && (stype
== NTP_MC_ADDR
||
819 stype
== NTP_SRV_ADDR
))
820 odhcp6c_add_state(STATE_SNTP_IP
,
822 else if (slen
> 0 && stype
== NTP_SRV_FQDN
)
823 odhcp6c_add_state(STATE_SNTP_FQDN
,
826 } else if (otype
== DHCPV6_OPT_SIP_SERVER_A
) {
828 odhcp6c_add_state(STATE_SIP_IP
, odata
, olen
);
829 } else if (otype
== DHCPV6_OPT_SIP_SERVER_D
) {
830 odhcp6c_add_state(STATE_SIP_FQDN
, odata
, olen
);
831 } else if (otype
== DHCPV6_OPT_INFO_REFRESH
&& olen
>= 4) {
832 uint32_t refresh
= ntohl(*((uint32_t*)odata
));
833 if (refresh
< (uint32_t)t1
)
835 } else if (otype
== DHCPV6_OPT_AUTH
&& olen
== -4 +
836 sizeof(struct dhcpv6_auth_reconfigure
)) {
837 struct dhcpv6_auth_reconfigure
*r
= (void*)&odata
[-4];
838 if (r
->protocol
== 3 && r
->algorithm
== 1 &&
840 memcpy(reconf_key
, r
->key
, sizeof(r
->key
));
841 } else if (otype
== DHCPV6_OPT_AFTR_NAME
&& olen
> 3) {
843 odhcp6c_get_state(STATE_AFTR_NAME
, &cur_len
);
845 odhcp6c_add_state(STATE_AFTR_NAME
, odata
, olen
);
846 } else if (otype
!= DHCPV6_OPT_CLIENTID
&&
847 otype
!= DHCPV6_OPT_SERVERID
) {
848 odhcp6c_add_state(STATE_CUSTOM_OPTS
,
849 &odata
[-4], olen
+ 4);
853 if (t1
== UINT32_MAX
)
856 if (t2
== UINT32_MAX
)
859 if (t3
== UINT32_MAX
)
866 static uint32_t dhcpv6_parse_ia(void *opt
, void *end
)
868 uint32_t timeout
= UINT32_MAX
; // Minimum timeout
869 uint16_t otype
, olen
;
873 dhcpv6_for_each_option(opt
, end
, otype
, olen
, odata
) {
874 struct odhcp6c_entry entry
= {IN6ADDR_ANY_INIT
, 0, 0,
875 IN6ADDR_ANY_INIT
, 0, 0, 0};
877 if (otype
== DHCPV6_OPT_IA_PREFIX
) {
878 struct dhcpv6_ia_prefix
*prefix
= (void*)&odata
[-4];
879 if (olen
+ 4U < sizeof(*prefix
))
882 entry
.valid
= ntohl(prefix
->valid
);
883 entry
.preferred
= ntohl(prefix
->preferred
);
885 if (entry
.preferred
> entry
.valid
)
888 entry
.length
= prefix
->prefix
;
889 entry
.target
= prefix
->addr
;
890 uint16_t stype
, slen
;
893 #ifdef EXT_PREFIX_CLASS
894 // Find prefix class, if any
895 dhcpv6_for_each_option(&prefix
[1], odata
+ olen
,
897 if (stype
== DHCPV6_OPT_PREFIX_CLASS
&& slen
== 2)
898 entry
.class = sdata
[0] << 8 | sdata
[1];
903 dhcpv6_for_each_option(odata
+ sizeof(*prefix
) - 4U,
904 odata
+ olen
, stype
, slen
, sdata
) {
905 if (stype
!= DHCPV6_OPT_PD_EXCLUDE
|| slen
< 2)
908 uint8_t elen
= sdata
[0];
912 if (elen
<= 32 || elen
<= entry
.length
) {
918 uint8_t bytes
= ((elen
- entry
.length
- 1) / 8) + 1;
924 uint32_t exclude
= 0;
926 exclude
= exclude
<< 8 | sdata
[bytes
];
929 exclude
>>= 8 - ((elen
- entry
.length
) % 8);
930 exclude
<<= 64 - elen
;
932 // Abusing router & priority fields for exclusion
933 entry
.router
= entry
.target
;
934 entry
.router
.s6_addr32
[1] |= htonl(exclude
);
935 entry
.priority
= elen
;
939 odhcp6c_update_entry(STATE_IA_PD
, &entry
);
942 memset(&entry
.router
, 0, sizeof(entry
.router
));
943 } else if (otype
== DHCPV6_OPT_IA_ADDR
) {
944 struct dhcpv6_ia_addr
*addr
= (void*)&odata
[-4];
945 if (olen
+ 4U < sizeof(*addr
))
948 entry
.preferred
= ntohl(addr
->preferred
);
949 entry
.valid
= ntohl(addr
->valid
);
951 if (entry
.preferred
> entry
.valid
)
955 entry
.target
= addr
->addr
;
957 #ifdef EXT_PREFIX_CLASS
958 uint16_t stype
, slen
;
960 // Find prefix class, if any
961 dhcpv6_for_each_option(&addr
[1], odata
+ olen
,
963 if (stype
== DHCPV6_OPT_PREFIX_CLASS
&& slen
== 2)
964 entry
.class = sdata
[0] << 8 | sdata
[1];
967 odhcp6c_update_entry(STATE_IA_NA
, &entry
);
969 if (entry
.valid
> 0 && timeout
> entry
.valid
)
970 timeout
= entry
.valid
;