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[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2013 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 <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <arpa/inet.h>
30 #include <netinet/in.h>
31
32 #include <net/if.h>
33 #include <net/ethernet.h>
34
35 #include "odhcp6c.h"
36 #include "md5.h"
37
38
39 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
40 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
41 #define DHCPV6_CLIENT_PORT 546
42 #define DHCPV6_SERVER_PORT 547
43 #define DHCPV6_DUID_LLADDR 3
44 #define DHCPV6_REQ_DELAY 1
45
46
47 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
48 const uint8_t transaction[3], enum dhcpv6_msg type,
49 const struct in6_addr *daddr);
50
51 static int dhcpv6_parse_ia(void *opt, void *end);
52
53 static int dhcpv6_calc_refresh_timers(void);
54 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
55 const uint16_t code, const void *status_msg, const int len,
56 int *ret);
57 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
58 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
59 const void *status_msg, const int len,
60 bool handled_status_codes[_DHCPV6_Status_Max],
61 int *ret);
62 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
63 static void dhcpv6_clear_all_server_cand(void);
64
65 static reply_handler dhcpv6_handle_reply;
66 static reply_handler dhcpv6_handle_advert;
67 static reply_handler dhcpv6_handle_rebind_reply;
68 static reply_handler dhcpv6_handle_reconfigure;
69 static int dhcpv6_commit_advert(void);
70
71
72
73 // RFC 3315 - 5.5 Timeout and Delay values
74 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
75 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
76 dhcpv6_handle_reconfigure, NULL},
77 [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
78 dhcpv6_handle_advert, dhcpv6_commit_advert},
79 [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
80 dhcpv6_handle_reply, NULL},
81 [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
82 dhcpv6_handle_reply, NULL},
83 [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
84 dhcpv6_handle_rebind_reply, NULL},
85 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
86 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
87 [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
88 dhcpv6_handle_reply, NULL},
89 };
90
91
92 // Sockets
93 static int sock = -1;
94 static int ifindex = -1;
95 static int64_t t1 = 0, t2 = 0, t3 = 0;
96
97 // IA states
98 static int request_prefix = -1;
99 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
100 static bool accept_reconfig = false;
101 // Server unicast address
102 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
103
104 // Reconfigure key
105 static uint8_t reconf_key[16];
106
107
108 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
109 {
110 request_prefix = request_pd;
111 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
112
113 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
114 if (sock < 0)
115 return -1;
116
117 // Detect interface
118 struct ifreq ifr;
119 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
120 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
121 return -1;
122 ifindex = ifr.ifr_ifindex;
123
124 // Create client DUID
125 size_t client_id_len;
126 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
127 if (client_id_len == 0) {
128 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
129 DHCPV6_DUID_LLADDR, 0, 1};
130
131 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
132 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
133
134 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
135 struct ifreq ifs[100], *ifp, *ifend;
136 struct ifconf ifc;
137 ifc.ifc_req = ifs;
138 ifc.ifc_len = sizeof(ifs);
139
140 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
141 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
142 // If our interface doesn't have an address...
143 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
144 for (ifp = ifc.ifc_req; ifp < ifend &&
145 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
146 memcpy(ifr.ifr_name, ifp->ifr_name,
147 sizeof(ifr.ifr_name));
148 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
149 continue;
150
151 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
152 ETHER_ADDR_LEN);
153 }
154 }
155
156 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
157 }
158
159 // Create ORO
160 uint16_t oro[] = {
161 htons(DHCPV6_OPT_SIP_SERVER_D),
162 htons(DHCPV6_OPT_SIP_SERVER_A),
163 htons(DHCPV6_OPT_DNS_SERVERS),
164 htons(DHCPV6_OPT_DNS_DOMAIN),
165 htons(DHCPV6_OPT_UNICAST),
166 htons(DHCPV6_OPT_NTP_SERVER),
167 htons(DHCPV6_OPT_AFTR_NAME),
168 htons(DHCPV6_OPT_PD_EXCLUDE),
169 #ifdef EXT_PREFIX_CLASS
170 htons(DHCPV6_OPT_PREFIX_CLASS),
171 #endif
172 };
173 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
174
175 // Configure IPv6-options
176 int val = 1;
177 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
178 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
179 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
180 val = 0;
181 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
182 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
183
184 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
185 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
186 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
187 return -1;
188
189 return 0;
190 }
191
192
193 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
194 {
195 na_mode = na;
196 pd_mode = pd;
197 }
198
199
200 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
201 {
202 // Build FQDN
203 char fqdn_buf[256];
204 gethostname(fqdn_buf, sizeof(fqdn_buf));
205 struct {
206 uint16_t type;
207 uint16_t len;
208 uint8_t flags;
209 uint8_t data[256];
210 } fqdn;
211 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
212 sizeof(fqdn.data), NULL, NULL);
213 fqdn.type = htons(DHCPV6_OPT_FQDN);
214 fqdn.len = htons(fqdn_len - 4);
215 fqdn.flags = 0;
216
217
218 // Build Client ID
219 size_t cl_id_len;
220 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
221
222 // Get Server ID
223 size_t srv_id_len;
224 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
225
226 // Build IA_PDs
227 size_t ia_pd_entries, ia_pd_len = 0;
228 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
229 ia_pd_entries /= sizeof(*e);
230 struct dhcpv6_ia_hdr hdr_ia_pd = {
231 htons(DHCPV6_OPT_IA_PD),
232 htons(sizeof(hdr_ia_pd) - 4),
233 1, 0, 0
234 };
235
236
237 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
238 for (size_t i = 0; i < ia_pd_entries; ++i) {
239 uint8_t ex_len = 0;
240 if (e[i].priority > 0)
241 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
242
243 struct dhcpv6_ia_prefix p = {
244 .type = htons(DHCPV6_OPT_IA_PREFIX),
245 .len = htons(sizeof(p) - 4U + ex_len),
246 .prefix = e[i].length,
247 .addr = e[i].target
248 };
249
250 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
251 ia_pd_len += sizeof(p);
252
253 if (ex_len) {
254 ia_pd[ia_pd_len++] = 0;
255 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
256 ia_pd[ia_pd_len++] = 0;
257 ia_pd[ia_pd_len++] = ex_len - 4;
258 ia_pd[ia_pd_len++] = e[i].priority;
259
260 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
261 excl >>= (64 - e[i].priority);
262 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
263
264 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
265 ia_pd[ia_pd_len + i] = excl & 0xff;
266 ia_pd_len += ex_len - 5;
267 }
268 }
269
270 struct dhcpv6_ia_prefix pref = {
271 .type = htons(DHCPV6_OPT_IA_PREFIX),
272 .len = htons(25), .prefix = request_prefix
273 };
274 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
275 ia_pd = (uint8_t*)&pref;
276 ia_pd_len = sizeof(pref);
277 }
278 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
279
280 // Build IA_NAs
281 size_t ia_na_entries, ia_na_len = 0;
282 void *ia_na = NULL;
283 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
284 ia_na_entries /= sizeof(*e);
285
286 struct dhcpv6_ia_hdr hdr_ia_na = {
287 htons(DHCPV6_OPT_IA_NA),
288 htons(sizeof(hdr_ia_na) - 4),
289 1, 0, 0
290 };
291
292 struct dhcpv6_ia_addr pa[ia_na_entries];
293 for (size_t i = 0; i < ia_na_entries; ++i) {
294 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
295 pa[i].len = htons(sizeof(pa[i]) - 4U);
296 pa[i].addr = e[i].target;
297 pa[i].preferred = 0;
298 pa[i].valid = 0;
299 }
300
301 ia_na = pa;
302 ia_na_len = sizeof(pa);
303 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
304
305 // Reconfigure Accept
306 struct {
307 uint16_t type;
308 uint16_t length;
309 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
310
311 // Request Information Refresh
312 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
313
314 // Prepare Header
315 size_t oro_len;
316 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
317 struct {
318 uint8_t type;
319 uint8_t trid[3];
320 uint16_t elapsed_type;
321 uint16_t elapsed_len;
322 uint16_t elapsed_value;
323 uint16_t oro_type;
324 uint16_t oro_len;
325 } hdr = {
326 type, {trid[0], trid[1], trid[2]},
327 htons(DHCPV6_OPT_ELAPSED), htons(2),
328 htons((ecs > 0xffff) ? 0xffff : ecs),
329 htons(DHCPV6_OPT_ORO), htons(oro_len),
330 };
331
332 struct iovec iov[] = {
333 {&hdr, sizeof(hdr)},
334 {oro, oro_len},
335 {&oro_refresh, 0},
336 {cl_id, cl_id_len},
337 {srv_id, srv_id_len},
338 {&reconf_accept, sizeof(reconf_accept)},
339 {&fqdn, fqdn_len},
340 {&hdr_ia_na, sizeof(hdr_ia_na)},
341 {ia_na, ia_na_len},
342 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
343 {ia_pd, ia_pd_len},
344 };
345
346 size_t cnt = ARRAY_SIZE(iov);
347 if (type == DHCPV6_MSG_INFO_REQ) {
348 cnt = 5;
349 iov[2].iov_len = sizeof(oro_refresh);
350 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
351 } else if (!request_prefix) {
352 cnt = 9;
353 }
354
355 // Disable IAs if not used
356 if (type != DHCPV6_MSG_SOLICIT) {
357 iov[5].iov_len = 0;
358 if (ia_na_len == 0)
359 iov[7].iov_len = 0;
360 if (ia_pd_len == 0)
361 iov[9].iov_len = 0;
362 }
363
364 if (na_mode == IA_MODE_NONE)
365 iov[7].iov_len = 0;
366
367 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
368 0, ALL_DHCPV6_RELAYS, ifindex};
369 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
370
371 switch (type) {
372 case DHCPV6_MSG_REQUEST:
373 case DHCPV6_MSG_RENEW:
374 case DHCPV6_MSG_RELEASE:
375 case DHCPV6_MSG_DECLINE:
376 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
377 odhcp6c_addr_in_scope(&server_addr)) {
378 srv.sin6_addr = server_addr;
379 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
380 srv.sin6_scope_id = 0;
381 }
382 break;
383 default:
384 break;
385 }
386
387 if (sendmsg(sock, &msg, 0) < 0) {
388 char in6_str[INET6_ADDRSTRLEN];
389
390 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
391 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
392 in6_str, sizeof(in6_str)), strerror(errno));
393 }
394 }
395
396
397 static int64_t dhcpv6_rand_delay(int64_t time)
398 {
399 int random;
400 odhcp6c_random(&random, sizeof(random));
401 return (time * ((int64_t)random % 1000LL)) / 10000LL;
402 }
403
404
405 int dhcpv6_request(enum dhcpv6_msg type)
406 {
407 uint8_t rc = 0;
408 uint64_t timeout = UINT32_MAX;
409 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
410
411 if (retx->delay) {
412 struct timespec ts = {0, 0};
413 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
414 nanosleep(&ts, NULL);
415 }
416
417 if (type == DHCPV6_MSG_UNKNOWN)
418 timeout = t1;
419 else if (type == DHCPV6_MSG_RENEW)
420 timeout = (t2 > t1) ? t2 - t1 : 0;
421 else if (type == DHCPV6_MSG_REBIND)
422 timeout = (t3 > t2) ? t3 - t2 : 0;
423
424 if (timeout == 0)
425 return -1;
426
427 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
428 retx->name, (unsigned long long)timeout, retx->max_rc);
429
430 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
431
432 // Generate transaction ID
433 uint8_t trid[3] = {0, 0, 0};
434 if (type != DHCPV6_MSG_UNKNOWN)
435 odhcp6c_random(trid, sizeof(trid));
436 ssize_t len = -1;
437 int64_t rto = 0;
438
439 do {
440 if (rto == 0) {
441 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
442
443 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
444 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
445 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
446
447 rto = (retx->init_timeo * 1000 + delay);
448 }
449 else
450 rto = (2 * rto + dhcpv6_rand_delay(rto));
451
452 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
453 rto = retx->max_timeo * 1000 +
454 dhcpv6_rand_delay(retx->max_timeo * 1000);
455
456 // Calculate end for this round and elapsed time
457 uint64_t round_end = round_start + rto;
458 elapsed = round_start - start;
459
460 // Don't wait too long
461 if (round_end - start > timeout * 1000)
462 round_end = timeout * 1000 + start;
463
464 // Built and send package
465 if (type != DHCPV6_MSG_UNKNOWN) {
466 if (type != DHCPV6_MSG_SOLICIT)
467 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
468 retx->name, (unsigned long long)elapsed, rc);
469 dhcpv6_send(type, trid, elapsed / 10);
470 rc++;
471 }
472
473 // Receive rounds
474 for (; len < 0 && (round_start < round_end);
475 round_start = odhcp6c_get_milli_time()) {
476 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
477 struct iovec iov = {buf, sizeof(buf)};
478 struct msghdr msg = {NULL, 0, &iov, 1,
479 cmsg_buf, sizeof(cmsg_buf), 0};
480 struct in6_pktinfo *pktinfo = NULL;
481
482 // Check for pending signal
483 if (odhcp6c_signal_process())
484 return -1;
485
486 // Set timeout for receiving
487 uint64_t t = round_end - round_start;
488 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
489 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
490 &timeout, sizeof(timeout));
491
492 // Receive cycle
493 len = recvmsg(sock, &msg, 0);
494 if (len < 0)
495 continue;
496
497 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
498 ch = CMSG_NXTHDR(&msg, ch)) {
499 if (ch->cmsg_level == SOL_IPV6 &&
500 ch->cmsg_type == IPV6_PKTINFO) {
501 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
502 break;
503 }
504 }
505
506 if (pktinfo == NULL) {
507 len = -1;
508 continue;
509 }
510
511 if (!dhcpv6_response_is_valid(buf, len, trid,
512 type, &pktinfo->ipi6_addr)) {
513 len = -1;
514 continue;
515 }
516
517 uint8_t *opt = &buf[4];
518 uint8_t *opt_end = opt + len - 4;
519
520 round_start = odhcp6c_get_milli_time();
521 elapsed = round_start - start;
522 syslog(LOG_NOTICE, "Got a valid reply after "
523 "%llums", (unsigned long long)elapsed);
524
525 if (retx->handler_reply)
526 len = retx->handler_reply(type, rc, opt, opt_end);
527
528 if (len > 0 && round_end - round_start > 1000)
529 round_end = 1000 + round_start;
530 }
531
532 // Allow
533 if (retx->handler_finish)
534 len = retx->handler_finish();
535 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
536
537 return len;
538 }
539
540 // Message validation checks according to RFC3315 chapter 15
541 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
542 const uint8_t transaction[3], enum dhcpv6_msg type,
543 const struct in6_addr *daddr)
544 {
545 const struct dhcpv6_header *rep = buf;
546 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
547 transaction, sizeof(rep->tr_id)))
548 return false; // Invalid reply
549
550 if (type == DHCPV6_MSG_SOLICIT) {
551 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
552 rep->msg_type != DHCPV6_MSG_REPLY)
553 return false;
554 } else if (type == DHCPV6_MSG_UNKNOWN) {
555 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
556 return false;
557 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
558 return false;
559 }
560
561 uint8_t *end = ((uint8_t*)buf) + len, *odata,
562 rcmsg = DHCPV6_MSG_UNKNOWN;
563 uint16_t otype, olen;
564 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
565 ia_present = false, options_valid = true;
566
567 size_t client_id_len, server_id_len;
568 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
569 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
570
571 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
572 if (otype == DHCPV6_OPT_CLIENTID) {
573 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
574 &odata[-4], client_id, client_id_len);
575 } else if (otype == DHCPV6_OPT_SERVERID) {
576 if (server_id_len)
577 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
578 &odata[-4], server_id, server_id_len);
579 else
580 serverid_ok = true;
581 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
582 sizeof(struct dhcpv6_auth_reconfigure)) {
583 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
584 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
585 continue;
586
587 md5_state_t md5;
588 uint8_t serverhash[16], secretbytes[16], hash[16];
589 memcpy(serverhash, r->key, sizeof(serverhash));
590 memset(r->key, 0, sizeof(r->key));
591 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
592
593 for (size_t i = 0; i < sizeof(secretbytes); ++i)
594 secretbytes[i] ^= 0x36;
595
596 md5_init(&md5);
597 md5_append(&md5, secretbytes, sizeof(secretbytes));
598 md5_append(&md5, buf, len);
599 md5_finish(&md5, hash);
600
601 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
602 secretbytes[i] ^= 0x36;
603 secretbytes[i] ^= 0x5c;
604 }
605
606 md5_init(&md5);
607 md5_append(&md5, secretbytes, sizeof(secretbytes));
608 md5_append(&md5, hash, 16);
609 md5_finish(&md5, hash);
610
611 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
612 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
613 rcmsg = odata[0];
614 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
615 ia_present = true;
616 if (olen < sizeof(struct dhcpv6_ia_hdr))
617 options_valid = false;
618 }
619 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
620 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
621 // Options are not allowed on global level
622 options_valid = false;
623 }
624 }
625
626 if (!options_valid)
627 return false;
628
629 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
630 return false;
631
632 if (rep->msg_type == DHCPV6_MSG_RECONF) {
633 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
634 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
635 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
636 return false;
637 }
638
639 return clientid_ok && serverid_ok;
640 }
641
642
643 int dhcpv6_poll_reconfigure(void)
644 {
645 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
646 if (ret != -1)
647 ret = dhcpv6_request(ret);
648
649 return ret;
650 }
651
652
653 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
654 const void *opt, const void *end)
655 {
656 uint16_t otype, olen;
657 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
658 dhcpv6_for_each_option(opt, end, otype, olen, odata)
659 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
660 odata[0] == DHCPV6_MSG_RENEW ||
661 odata[0] == DHCPV6_MSG_INFO_REQ))
662 msg = odata[0];
663
664 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
665 return msg;
666 }
667
668
669 // Collect all advertised servers
670 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
671 const void *opt, const void *end)
672 {
673 uint16_t olen, otype;
674 uint8_t *odata, pref = 0;
675 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
676 IN6ADDR_ANY_INIT, NULL, NULL, 0, 0};
677 bool have_na = false;
678 int have_pd = 0;
679
680 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
681 if (orig == DHCPV6_MSG_SOLICIT &&
682 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
683 olen > sizeof(struct dhcpv6_ia_hdr)) {
684 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
685 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
686 }
687
688 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
689 memcpy(cand.duid, odata, olen);
690 cand.duid_len = olen;
691 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
692 int error = ((int)odata[0] << 8 | (int)odata[1]);
693
694 switch (error) {
695 case DHCPV6_NoPrefixAvail:
696 // Status code on global level
697 if (pd_mode == IA_MODE_FORCE)
698 return -1;
699 cand.preference -= 2000;
700 break;
701
702 case DHCPV6_NoAddrsAvail:
703 // Status code on global level
704 if (na_mode == IA_MODE_FORCE)
705 return -1;
706 break;
707
708 default :
709 break;
710 }
711 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
712 cand.preference >= 0) {
713 cand.preference = pref = odata[0];
714 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
715 cand.server_addr = *(struct in6_addr *)odata;
716 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
717 cand.wants_reconfigure = true;
718 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
719 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
720 uint8_t *oend = odata + olen, *d;
721 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
722 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
723 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
724 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
725 have_pd = p->prefix;
726 }
727 }
728 } else if (otype == DHCPV6_OPT_IA_NA) {
729 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
730 uint8_t *oend = odata + olen, *d;
731 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
732 if (otype == DHCPV6_OPT_IA_ADDR)
733 have_na = true;
734 }
735 }
736
737 if ((!have_na && na_mode == IA_MODE_FORCE) ||
738 (!have_pd && pd_mode == IA_MODE_FORCE))
739 return -1;
740
741 if (na_mode != IA_MODE_NONE && !have_na) {
742 cand.has_noaddravail = true;
743 cand.preference -= 1000;
744 }
745
746 if (pd_mode != IA_MODE_NONE) {
747 if (have_pd)
748 cand.preference += 2000 + (128 - have_pd);
749 else
750 cand.preference -= 2000;
751 }
752
753 if (cand.duid_len > 0) {
754 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
755 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
756 dhcpv6_add_server_cand(&cand);
757 }
758
759 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
760 }
761
762
763 static int dhcpv6_commit_advert(void)
764 {
765 return dhcpv6_promote_server_cand();
766 }
767
768
769 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
770 const void *opt, const void *end)
771 {
772 dhcpv6_handle_advert(orig, rc, opt, end);
773 if (dhcpv6_commit_advert() < 0)
774 return -1;
775
776 return dhcpv6_handle_reply(orig, rc, opt, end);
777 }
778
779
780 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
781 const void *opt, const void *end)
782 {
783 uint8_t *odata;
784 uint16_t otype, olen;
785 uint32_t refresh = UINT32_MAX;
786 int ret = 1;
787 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
788
789 odhcp6c_expire();
790
791 if (orig == DHCPV6_MSG_UNKNOWN) {
792 static time_t last_update = 0;
793 time_t now = odhcp6c_get_milli_time() / 1000;
794
795 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
796 last_update = now;
797
798 t1 -= elapsed;
799 t2 -= elapsed;
800 t3 -= elapsed;
801
802 if (t1 < 0)
803 t1 = 0;
804
805 if (t2 < 0)
806 t2 = 0;
807
808 if (t3 < 0)
809 t3 = 0;
810 }
811
812 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
813 // Delete NA and PD we have in the state from the Advert
814 odhcp6c_clear_state(STATE_IA_NA);
815 odhcp6c_clear_state(STATE_IA_PD);
816 }
817
818 if (opt) {
819 odhcp6c_clear_state(STATE_DNS);
820 odhcp6c_clear_state(STATE_SEARCH);
821 odhcp6c_clear_state(STATE_SNTP_IP);
822 odhcp6c_clear_state(STATE_SNTP_FQDN);
823 odhcp6c_clear_state(STATE_SIP_IP);
824 odhcp6c_clear_state(STATE_SIP_FQDN);
825 odhcp6c_clear_state(STATE_AFTR_NAME);
826 }
827
828 // Parse and find all matching IAs
829 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
830 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
831 && olen > sizeof(struct dhcpv6_ia_hdr)) {
832 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
833
834 // Test ID
835 if (ia_hdr->iaid != 1)
836 continue;
837
838 uint16_t code = DHCPV6_Success;
839 uint16_t stype, slen;
840 uint8_t *sdata;
841 // Get and handle status code
842 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
843 stype, slen, sdata) {
844 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
845 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
846 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
847
848 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
849
850 if (code == DHCPV6_Success)
851 continue;
852
853 dhcpv6_handle_ia_status_code(orig, ia_hdr,
854 code, mdata, mlen, handled_status_codes, &ret);
855
856
857 if (ret > 0)
858 return ret;
859 break;
860 }
861 }
862
863 if (code != DHCPV6_Success)
864 continue;
865
866 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
867 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
868 server_addr = *(struct in6_addr *)odata;
869 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
870 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
871 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
872 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
873
874 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
875 }
876 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
877 if (olen % 16 == 0)
878 odhcp6c_add_state(STATE_DNS, odata, olen);
879 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
880 odhcp6c_add_state(STATE_SEARCH, odata, olen);
881 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
882 uint16_t stype, slen;
883 uint8_t *sdata;
884 // Test status and bail if error
885 dhcpv6_for_each_option(odata, odata + olen,
886 stype, slen, sdata) {
887 if (slen == 16 && (stype == NTP_MC_ADDR ||
888 stype == NTP_SRV_ADDR))
889 odhcp6c_add_state(STATE_SNTP_IP,
890 sdata, slen);
891 else if (slen > 0 && stype == NTP_SRV_FQDN)
892 odhcp6c_add_state(STATE_SNTP_FQDN,
893 sdata, slen);
894 }
895 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
896 if (olen == 16)
897 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
898 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
899 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
900 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
901 refresh = ntohl(*((uint32_t*)odata));
902 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
903 sizeof(struct dhcpv6_auth_reconfigure)) {
904 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
905 if (r->protocol == 3 && r->algorithm == 1 &&
906 r->reconf_type == 1)
907 memcpy(reconf_key, r->key, sizeof(r->key));
908 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
909 size_t cur_len;
910 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
911 if (cur_len == 0)
912 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
913 } else if (otype != DHCPV6_OPT_CLIENTID &&
914 otype != DHCPV6_OPT_SERVERID) {
915 odhcp6c_add_state(STATE_CUSTOM_OPTS,
916 &odata[-4], olen + 4);
917 }
918 }
919
920 if (orig != DHCPV6_MSG_INFO_REQ) {
921 // Update refresh timers if no fatal status code was received
922 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
923 switch (orig) {
924 case DHCPV6_MSG_RENEW:
925 // Send further renews if T1 is not set
926 if (!t1)
927 ret = -1;
928 break;
929 case DHCPV6_MSG_REBIND:
930 // Send further rebinds if T1 and T2 is not set
931 if (!t1 && !t2)
932 ret = -1;
933 break;
934
935 case DHCPV6_MSG_REQUEST:
936 // All server candidates can be cleared if not yet bound
937 if (!odhcp6c_is_bound())
938 dhcpv6_clear_all_server_cand();
939
940 default :
941 break;
942 }
943 }
944 }
945 else if (ret > 0) {
946 // All server candidates can be cleared if not yet bound
947 if (!odhcp6c_is_bound())
948 dhcpv6_clear_all_server_cand();
949
950 t1 = refresh;
951 }
952
953 return ret;
954 }
955
956
957 static int dhcpv6_parse_ia(void *opt, void *end)
958 {
959 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
960 int parsed_ia = 0;
961 uint32_t t1, t2;
962 uint16_t otype, olen;
963 uint8_t *odata;
964
965 t1 = ntohl(ia_hdr->t1);
966 t2 = ntohl(ia_hdr->t2);
967
968 if (t1 > t2)
969 return 0;
970
971 // Update address IA
972 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
973 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
974 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
975
976 if (otype == DHCPV6_OPT_IA_PREFIX) {
977 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
978 if (olen + 4U < sizeof(*prefix))
979 continue;
980
981 entry.valid = ntohl(prefix->valid);
982 entry.preferred = ntohl(prefix->preferred);
983
984 if (entry.preferred > entry.valid)
985 continue;
986
987 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
988 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
989 if (entry.t1 > entry.t2)
990 entry.t1 = entry.t2;
991
992 entry.length = prefix->prefix;
993 entry.target = prefix->addr;
994 uint16_t stype, slen;
995 uint8_t *sdata;
996
997 #ifdef EXT_PREFIX_CLASS
998 // Find prefix class, if any
999 dhcpv6_for_each_option(&prefix[1], odata + olen,
1000 stype, slen, sdata)
1001 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1002 entry.class = sdata[0] << 8 | sdata[1];
1003 #endif
1004
1005 // Parse PD-exclude
1006 bool ok = true;
1007 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1008 odata + olen, stype, slen, sdata) {
1009 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1010 continue;
1011
1012 uint8_t elen = sdata[0];
1013 if (elen > 64)
1014 elen = 64;
1015
1016 if (elen <= 32 || elen <= entry.length) {
1017 ok = false;
1018 continue;
1019 }
1020
1021
1022 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1023 if (slen <= bytes) {
1024 ok = false;
1025 continue;
1026 }
1027
1028 uint32_t exclude = 0;
1029 do {
1030 exclude = exclude << 8 | sdata[bytes];
1031 } while (--bytes);
1032
1033 exclude >>= 8 - ((elen - entry.length) % 8);
1034 exclude <<= 64 - elen;
1035
1036 // Abusing router & priority fields for exclusion
1037 entry.router = entry.target;
1038 entry.router.s6_addr32[1] |= htonl(exclude);
1039 entry.priority = elen;
1040 }
1041
1042 if (ok) {
1043 odhcp6c_update_entry(STATE_IA_PD, &entry);
1044 parsed_ia++;
1045 }
1046
1047 entry.priority = 0;
1048 memset(&entry.router, 0, sizeof(entry.router));
1049 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1050 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1051 if (olen + 4U < sizeof(*addr))
1052 continue;
1053
1054 entry.preferred = ntohl(addr->preferred);
1055 entry.valid = ntohl(addr->valid);
1056
1057 if (entry.preferred > entry.valid)
1058 continue;
1059
1060 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1061 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1062 if (entry.t1 > entry.t2)
1063 entry.t1 = entry.t2;
1064
1065 entry.length = 128;
1066 entry.target = addr->addr;
1067
1068 #ifdef EXT_PREFIX_CLASS
1069 uint16_t stype, slen;
1070 uint8_t *sdata;
1071 // Find prefix class, if any
1072 dhcpv6_for_each_option(&addr[1], odata + olen,
1073 stype, slen, sdata)
1074 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1075 entry.class = sdata[0] << 8 | sdata[1];
1076 #endif
1077
1078 odhcp6c_update_entry(STATE_IA_NA, &entry);
1079 parsed_ia++;
1080 }
1081 }
1082 return parsed_ia;
1083 }
1084
1085
1086 static int dhcpv6_calc_refresh_timers(void)
1087 {
1088 struct odhcp6c_entry *e;
1089 size_t ia_na_entries, ia_pd_entries, i;
1090 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1091
1092 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1093 ia_na_entries /= sizeof(*e);
1094 for (i = 0; i < ia_na_entries; i++) {
1095 if (e[i].t1 < l_t1)
1096 l_t1 = e[i].t1;
1097
1098 if (e[i].t2 < l_t2)
1099 l_t2 = e[i].t2;
1100
1101 if (e[i].valid > l_t3)
1102 l_t3 = e[i].valid;
1103 }
1104
1105 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1106 ia_pd_entries /= sizeof(*e);
1107 for (i = 0; i < ia_pd_entries; i++) {
1108 if (e[i].t1 < l_t1)
1109 l_t1 = e[i].t1;
1110
1111 if (e[i].t2 < l_t2)
1112 l_t2 = e[i].t2;
1113
1114 if (e[i].valid > l_t3)
1115 l_t3 = e[i].valid;
1116 }
1117
1118 if (ia_pd_entries || ia_na_entries) {
1119 t1 = l_t1;
1120 t2 = l_t2;
1121 t3 = l_t3;
1122 }
1123
1124 return (int)(ia_pd_entries + ia_na_entries);
1125 }
1126
1127
1128 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1129 const void *status_msg, const int len)
1130 {
1131 uint8_t buf[len + 3];
1132
1133 memset(buf, 0, sizeof(buf));
1134 if (len) {
1135 buf[0] = '(';
1136 memcpy(&buf[1], status_msg, len);
1137 buf[len + 1] = ')';
1138 }
1139
1140 syslog(LOG_WARNING, "Server returned %s status %i %s",
1141 scope, code, buf);
1142 }
1143
1144
1145 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1146 const uint16_t code, const void *status_msg, const int len,
1147 int *ret)
1148 {
1149 dhcpv6_log_status_code(code, "message", status_msg, len);
1150
1151 switch (code) {
1152 case DHCPV6_UnspecFail:
1153 // Generic failure
1154 *ret = 0;
1155 break;
1156
1157 case DHCPV6_UseMulticast:
1158 switch(orig) {
1159 case DHCPV6_MSG_REQUEST:
1160 case DHCPV6_MSG_RENEW:
1161 case DHCPV6_MSG_RELEASE:
1162 case DHCPV6_MSG_DECLINE:
1163 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1164 server_addr = in6addr_any;
1165 *ret = 0;
1166 break;
1167 default:
1168 break;
1169 }
1170 break;
1171
1172 case DHCPV6_NoAddrsAvail:
1173 case DHCPV6_NoPrefixAvail:
1174 if (orig == DHCPV6_MSG_REQUEST)
1175 *ret = 0; // Failure
1176 break;
1177
1178 default:
1179 break;
1180 }
1181 }
1182
1183
1184 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1185 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1186 const void *status_msg, const int len,
1187 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1188 {
1189 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1190 "IA_NA" : "IA_PD", status_msg, len);
1191
1192 switch (code) {
1193 case DHCPV6_NoBinding:
1194 switch (orig) {
1195 case DHCPV6_MSG_RENEW:
1196 case DHCPV6_MSG_REBIND:
1197 if ((*ret > 0) && !handled_status_codes[code])
1198 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1199 break;
1200
1201 default:
1202 break;
1203 }
1204 break;
1205
1206 case DHCPV6_NoAddrsAvail:
1207 case DHCPV6_NoPrefixAvail:
1208 switch (orig) {
1209 case DHCPV6_MSG_REQUEST:
1210 if (*ret != 0)
1211 *ret = 0;
1212 break;
1213 default:
1214 break;
1215 }
1216 break;
1217
1218 case DHCPV6_NotOnLink:
1219 // TODO handle not onlink in case of confirm
1220 break;
1221
1222 default:
1223 break;
1224 }
1225 }
1226
1227 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1228 {
1229 size_t cand_len, i;
1230 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1231
1232 // Remove identical duid server candidate
1233 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1234 if (cand->duid_len == c[i].duid_len &&
1235 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1236 free(c[i].ia_na);
1237 free(c[i].ia_pd);
1238 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1239 break;
1240 }
1241 }
1242
1243 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1244 i < cand_len / sizeof(*c); ++i) {
1245 if (c[i].preference < cand->preference)
1246 break;
1247 }
1248
1249 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1250 }
1251
1252 static void dhcpv6_clear_all_server_cand(void)
1253 {
1254 size_t cand_len, i;
1255 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1256
1257 // Server candidates need deep delete for IA_NA/IA_PD
1258 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1259 if (c[i].ia_na)
1260 free(c[i].ia_na);
1261 if (c[i].ia_pd)
1262 free(c[i].ia_pd);
1263 }
1264 odhcp6c_clear_state(STATE_SERVER_CAND);
1265 }
1266
1267 int dhcpv6_promote_server_cand(void)
1268 {
1269 size_t cand_len;
1270 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1271 uint16_t hdr[2];
1272 int ret = DHCPV6_STATELESS;
1273
1274 // Clear lingering candidate state info
1275 odhcp6c_clear_state(STATE_SERVER_ID);
1276 odhcp6c_clear_state(STATE_IA_NA);
1277 odhcp6c_clear_state(STATE_IA_PD);
1278
1279 if (!cand_len)
1280 return -1;
1281
1282 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1283 na_mode = IA_MODE_NONE;
1284 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1285 }
1286
1287 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1288 hdr[1] = htons(cand->duid_len);
1289 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1290 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1291 accept_reconfig = cand->wants_reconfigure;
1292 if (cand->ia_na_len) {
1293 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1294 free(cand->ia_na);
1295 if (na_mode != IA_MODE_NONE)
1296 ret = DHCPV6_STATEFUL;
1297 }
1298 if (cand->ia_pd_len) {
1299 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1300 free(cand->ia_pd);
1301 if (request_prefix)
1302 ret = DHCPV6_STATEFUL;
1303 }
1304
1305 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1306
1307 return ret;
1308 }
Openwrt DHCPv6 Client