projects / project / odhcp6c.git / blob
? search:


9e3d6c437bf4785e3356490cfd068ae5e8ceb7a1
[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 <netinet/in.h>
30
31 #include <net/if.h>
32 #include <net/ethernet.h>
33
34 #include "odhcp6c.h"
35 #include "md5.h"
36
37
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
44
45 #define DHCPV6_SOL_MAX_RT_MIN 60
46 #define DHCPV6_SOL_MAX_RT_MAX 86400
47 #define DHCPV6_INF_MAX_RT_MIN 60
48 #define DHCPV6_INF_MAX_RT_MAX 86400
49
50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
51 const uint8_t transaction[3], enum dhcpv6_msg type,
52 const struct in6_addr *daddr);
53
54 static int dhcpv6_parse_ia(void *opt, void *end);
55
56 static int dhcpv6_calc_refresh_timers(void);
57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
58 const uint16_t code, const void *status_msg, const int len,
59 int *ret);
60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
61 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
62 const void *status_msg, const int len,
63 bool handled_status_codes[_DHCPV6_Status_Max],
64 int *ret);
65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
66 static void dhcpv6_clear_all_server_cand(void);
67
68 static reply_handler dhcpv6_handle_reply;
69 static reply_handler dhcpv6_handle_advert;
70 static reply_handler dhcpv6_handle_rebind_reply;
71 static reply_handler dhcpv6_handle_reconfigure;
72 static int dhcpv6_commit_advert(void);
73
74
75
76 // RFC 3315 - 5.5 Timeout and Delay values
77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
78 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
79 dhcpv6_handle_reconfigure, NULL},
80 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
81 dhcpv6_handle_advert, dhcpv6_commit_advert},
82 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
83 dhcpv6_handle_reply, NULL},
84 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
85 dhcpv6_handle_reply, NULL},
86 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
87 dhcpv6_handle_rebind_reply, NULL},
88 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
89 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
90 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
91 dhcpv6_handle_reply, NULL},
92 };
93
94
95 // Sockets
96 static int sock = -1;
97 static int ifindex = -1;
98 static int64_t t1 = 0, t2 = 0, t3 = 0;
99
100 // IA states
101 static int request_prefix = -1;
102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
103 static bool accept_reconfig = false;
104
105 // Reconfigure key
106 static uint8_t reconf_key[16];
107
108
109 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
110 {
111 request_prefix = request_pd;
112 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
113
114 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
115 if (sock < 0)
116 return -1;
117
118 // Detect interface
119 struct ifreq ifr;
120 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
121 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
122 return -1;
123 ifindex = ifr.ifr_ifindex;
124
125 // Create client DUID
126 size_t client_id_len;
127 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
128 if (client_id_len == 0) {
129 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
130 DHCPV6_DUID_LLADDR, 0, 1};
131
132 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
133 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
134
135 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
136 struct ifreq ifs[100], *ifp, *ifend;
137 struct ifconf ifc;
138 ifc.ifc_req = ifs;
139 ifc.ifc_len = sizeof(ifs);
140
141 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
142 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
143 // If our interface doesn't have an address...
144 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
145 for (ifp = ifc.ifc_req; ifp < ifend &&
146 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
147 memcpy(ifr.ifr_name, ifp->ifr_name,
148 sizeof(ifr.ifr_name));
149 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
150 continue;
151
152 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
153 ETHER_ADDR_LEN);
154 }
155 }
156
157 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
158 }
159
160 // Create ORO
161 uint16_t oro[] = {
162 htons(DHCPV6_OPT_SIP_SERVER_D),
163 htons(DHCPV6_OPT_SIP_SERVER_A),
164 htons(DHCPV6_OPT_DNS_SERVERS),
165 htons(DHCPV6_OPT_DNS_DOMAIN),
166 htons(DHCPV6_OPT_NTP_SERVER),
167 htons(DHCPV6_OPT_AFTR_NAME),
168 htons(DHCPV6_OPT_PD_EXCLUDE),
169 htons(DHCPV6_OPT_SOL_MAX_RT),
170 htons(DHCPV6_OPT_INF_MAX_RT),
171 #ifdef EXT_PREFIX_CLASS
172 htons(DHCPV6_OPT_PREFIX_CLASS),
173 #endif
174 };
175 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
176
177 // Configure IPv6-options
178 int val = 1;
179 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
180 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
181 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
182 val = 0;
183 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
184 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
185
186 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
187 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
188 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
189 return -1;
190
191 return 0;
192 }
193
194
195 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
196 {
197 na_mode = na;
198 pd_mode = pd;
199 }
200
201
202 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
203 {
204 // Build FQDN
205 char fqdn_buf[256];
206 gethostname(fqdn_buf, sizeof(fqdn_buf));
207 struct {
208 uint16_t type;
209 uint16_t len;
210 uint8_t flags;
211 uint8_t data[256];
212 } fqdn;
213 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
214 sizeof(fqdn.data), NULL, NULL);
215 fqdn.type = htons(DHCPV6_OPT_FQDN);
216 fqdn.len = htons(fqdn_len - 4);
217 fqdn.flags = 0;
218
219
220 // Build Client ID
221 size_t cl_id_len;
222 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
223
224 // Get Server ID
225 size_t srv_id_len;
226 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
227
228 // Build IA_PDs
229 size_t ia_pd_entries, ia_pd_len = 0;
230 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
231 ia_pd_entries /= sizeof(*e);
232 struct dhcpv6_ia_hdr hdr_ia_pd = {
233 htons(DHCPV6_OPT_IA_PD),
234 htons(sizeof(hdr_ia_pd) - 4),
235 1, 0, 0
236 };
237
238
239 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
240 for (size_t i = 0; i < ia_pd_entries; ++i) {
241 uint8_t ex_len = 0;
242 if (e[i].priority > 0)
243 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
244
245 struct dhcpv6_ia_prefix p = {
246 .type = htons(DHCPV6_OPT_IA_PREFIX),
247 .len = htons(sizeof(p) - 4U + ex_len),
248 .prefix = e[i].length,
249 .addr = e[i].target
250 };
251
252 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
253 ia_pd_len += sizeof(p);
254
255 if (ex_len) {
256 ia_pd[ia_pd_len++] = 0;
257 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
258 ia_pd[ia_pd_len++] = 0;
259 ia_pd[ia_pd_len++] = ex_len - 4;
260 ia_pd[ia_pd_len++] = e[i].priority;
261
262 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
263 excl >>= (64 - e[i].priority);
264 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
265
266 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
267 ia_pd[ia_pd_len + i] = excl & 0xff;
268 ia_pd_len += ex_len - 5;
269 }
270 }
271
272 struct dhcpv6_ia_prefix pref = {
273 .type = htons(DHCPV6_OPT_IA_PREFIX),
274 .len = htons(25), .prefix = request_prefix
275 };
276 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
277 ia_pd = (uint8_t*)&pref;
278 ia_pd_len = sizeof(pref);
279 }
280 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
281
282 // Build IA_NAs
283 size_t ia_na_entries, ia_na_len = 0;
284 void *ia_na = NULL;
285 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
286 ia_na_entries /= sizeof(*e);
287
288 struct dhcpv6_ia_hdr hdr_ia_na = {
289 htons(DHCPV6_OPT_IA_NA),
290 htons(sizeof(hdr_ia_na) - 4),
291 1, 0, 0
292 };
293
294 struct dhcpv6_ia_addr pa[ia_na_entries];
295 for (size_t i = 0; i < ia_na_entries; ++i) {
296 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
297 pa[i].len = htons(sizeof(pa[i]) - 4U);
298 pa[i].addr = e[i].target;
299 pa[i].preferred = 0;
300 pa[i].valid = 0;
301 }
302
303 ia_na = pa;
304 ia_na_len = sizeof(pa);
305 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
306
307 // Reconfigure Accept
308 struct {
309 uint16_t type;
310 uint16_t length;
311 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
312
313 // Request Information Refresh
314 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
315
316 // Prepare Header
317 size_t oro_len;
318 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
319 struct {
320 uint8_t type;
321 uint8_t trid[3];
322 uint16_t elapsed_type;
323 uint16_t elapsed_len;
324 uint16_t elapsed_value;
325 uint16_t oro_type;
326 uint16_t oro_len;
327 } hdr = {
328 type, {trid[0], trid[1], trid[2]},
329 htons(DHCPV6_OPT_ELAPSED), htons(2),
330 htons((ecs > 0xffff) ? 0xffff : ecs),
331 htons(DHCPV6_OPT_ORO), htons(oro_len),
332 };
333
334 struct iovec iov[] = {
335 {&hdr, sizeof(hdr)},
336 {oro, oro_len},
337 {&oro_refresh, 0},
338 {cl_id, cl_id_len},
339 {srv_id, srv_id_len},
340 {&reconf_accept, sizeof(reconf_accept)},
341 {&fqdn, fqdn_len},
342 {&hdr_ia_na, sizeof(hdr_ia_na)},
343 {ia_na, ia_na_len},
344 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
345 {ia_pd, ia_pd_len},
346 };
347
348 size_t cnt = ARRAY_SIZE(iov);
349 if (type == DHCPV6_MSG_INFO_REQ) {
350 cnt = 5;
351 iov[2].iov_len = sizeof(oro_refresh);
352 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
353 } else if (!request_prefix) {
354 cnt = 9;
355 }
356
357 // Disable IAs if not used
358 if (type != DHCPV6_MSG_SOLICIT) {
359 iov[5].iov_len = 0;
360 if (ia_na_len == 0)
361 iov[7].iov_len = 0;
362 if (ia_pd_len == 0)
363 iov[9].iov_len = 0;
364 }
365
366 if (na_mode == IA_MODE_NONE)
367 iov[7].iov_len = 0;
368
369 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
370 0, ALL_DHCPV6_RELAYS, ifindex};
371 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
372
373 sendmsg(sock, &msg, 0);
374 }
375
376
377 static int64_t dhcpv6_rand_delay(int64_t time)
378 {
379 int random;
380 odhcp6c_random(&random, sizeof(random));
381 return (time * ((int64_t)random % 1000LL)) / 10000LL;
382 }
383
384
385 int dhcpv6_request(enum dhcpv6_msg type)
386 {
387 uint8_t rc = 0;
388 uint64_t timeout = UINT32_MAX;
389 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
390
391 if (retx->delay) {
392 struct timespec ts = {0, 0};
393 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
394 nanosleep(&ts, NULL);
395 }
396
397 if (type == DHCPV6_MSG_UNKNOWN)
398 timeout = t1;
399 else if (type == DHCPV6_MSG_RENEW)
400 timeout = (t2 > t1) ? t2 - t1 : 0;
401 else if (type == DHCPV6_MSG_REBIND)
402 timeout = (t3 > t2) ? t3 - t2 : 0;
403
404 if (timeout == 0)
405 return -1;
406
407 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
408 retx->name, (unsigned long long)timeout, retx->max_rc);
409
410 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
411
412 // Generate transaction ID
413 uint8_t trid[3] = {0, 0, 0};
414 if (type != DHCPV6_MSG_UNKNOWN)
415 odhcp6c_random(trid, sizeof(trid));
416 ssize_t len = -1;
417 int64_t rto = 0;
418
419 do {
420 if (rto == 0) {
421 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
422
423 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
424 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
425 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
426
427 rto = (retx->init_timeo * 1000 + delay);
428 }
429 else
430 rto = (2 * rto + dhcpv6_rand_delay(rto));
431
432 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
433 rto = retx->max_timeo * 1000 +
434 dhcpv6_rand_delay(retx->max_timeo * 1000);
435
436 // Calculate end for this round and elapsed time
437 uint64_t round_end = round_start + rto;
438 elapsed = round_start - start;
439
440 // Don't wait too long
441 if (round_end - start > timeout * 1000)
442 round_end = timeout * 1000 + start;
443
444 // Built and send package
445 if (type != DHCPV6_MSG_UNKNOWN) {
446 if (type != DHCPV6_MSG_SOLICIT)
447 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
448 retx->name, (unsigned long long)elapsed, rc);
449 dhcpv6_send(type, trid, elapsed / 10);
450 rc++;
451 }
452
453 // Receive rounds
454 for (; len < 0 && (round_start < round_end);
455 round_start = odhcp6c_get_milli_time()) {
456 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
457 struct iovec iov = {buf, sizeof(buf)};
458 struct msghdr msg = {NULL, 0, &iov, 1,
459 cmsg_buf, sizeof(cmsg_buf), 0};
460 struct in6_pktinfo *pktinfo = NULL;
461
462 // Check for pending signal
463 if (odhcp6c_signal_process())
464 return -1;
465
466 // Set timeout for receiving
467 uint64_t t = round_end - round_start;
468 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
469 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
470 &timeout, sizeof(timeout));
471
472 // Receive cycle
473 len = recvmsg(sock, &msg, 0);
474 if (len < 0)
475 continue;
476
477 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
478 ch = CMSG_NXTHDR(&msg, ch)) {
479 if (ch->cmsg_level == SOL_IPV6 &&
480 ch->cmsg_type == IPV6_PKTINFO) {
481 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
482 break;
483 }
484 }
485
486 if (pktinfo == NULL) {
487 len = -1;
488 continue;
489 }
490
491 if (!dhcpv6_response_is_valid(buf, len, trid,
492 type, &pktinfo->ipi6_addr)) {
493 len = -1;
494 continue;
495 }
496
497 uint8_t *opt = &buf[4];
498 uint8_t *opt_end = opt + len - 4;
499
500 round_start = odhcp6c_get_milli_time();
501 elapsed = round_start - start;
502 syslog(LOG_NOTICE, "Got a valid reply after "
503 "%llums", (unsigned long long)elapsed);
504
505 if (retx->handler_reply)
506 len = retx->handler_reply(type, rc, opt, opt_end);
507
508 if (len > 0 && round_end - round_start > 1000)
509 round_end = 1000 + round_start;
510 }
511
512 // Allow
513 if (retx->handler_finish)
514 len = retx->handler_finish();
515 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
516
517 return len;
518 }
519
520 // Message validation checks according to RFC3315 chapter 15
521 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
522 const uint8_t transaction[3], enum dhcpv6_msg type,
523 const struct in6_addr *daddr)
524 {
525 const struct dhcpv6_header *rep = buf;
526 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
527 transaction, sizeof(rep->tr_id)))
528 return false; // Invalid reply
529
530 if (type == DHCPV6_MSG_SOLICIT) {
531 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
532 rep->msg_type != DHCPV6_MSG_REPLY)
533 return false;
534 } else if (type == DHCPV6_MSG_UNKNOWN) {
535 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
536 return false;
537 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
538 return false;
539 }
540
541 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
542 rcmsg = DHCPV6_MSG_UNKNOWN;
543 uint16_t otype, olen = UINT16_MAX;
544 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
545 ia_present = false, options_valid = true;
546
547 size_t client_id_len, server_id_len;
548 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
549 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
550
551 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
552 if (otype == DHCPV6_OPT_CLIENTID) {
553 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
554 &odata[-4], client_id, client_id_len);
555 } else if (otype == DHCPV6_OPT_SERVERID) {
556 if (server_id_len)
557 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
558 &odata[-4], server_id, server_id_len);
559 else
560 serverid_ok = true;
561 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
562 sizeof(struct dhcpv6_auth_reconfigure)) {
563 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
564 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
565 continue;
566
567 md5_ctx_t md5;
568 uint8_t serverhash[16], secretbytes[16], hash[16];
569 memcpy(serverhash, r->key, sizeof(serverhash));
570 memset(r->key, 0, sizeof(r->key));
571 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
572
573 for (size_t i = 0; i < sizeof(secretbytes); ++i)
574 secretbytes[i] ^= 0x36;
575
576 md5_begin(&md5);
577 md5_hash(secretbytes, sizeof(secretbytes), &md5);
578 md5_hash(buf, len, &md5);
579 md5_end(hash, &md5);
580
581 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
582 secretbytes[i] ^= 0x36;
583 secretbytes[i] ^= 0x5c;
584 }
585
586 md5_begin(&md5);
587 md5_hash(secretbytes, sizeof(secretbytes), &md5);
588 md5_hash(hash, 16, &md5);
589 md5_end(hash, &md5);
590
591 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
592 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
593 rcmsg = odata[0];
594 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
595 ia_present = true;
596 if (olen < sizeof(struct dhcpv6_ia_hdr))
597 options_valid = false;
598 }
599 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
600 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
601 // Options are not allowed on global level
602 options_valid = false;
603 }
604 }
605
606 if (!options_valid || ((odata + olen) > end))
607 return false;
608
609 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
610 return false;
611
612 if (rep->msg_type == DHCPV6_MSG_RECONF) {
613 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
614 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
615 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
616 return false;
617 }
618
619 return clientid_ok && serverid_ok;
620 }
621
622
623 int dhcpv6_poll_reconfigure(void)
624 {
625 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
626 if (ret != -1)
627 ret = dhcpv6_request(ret);
628
629 return ret;
630 }
631
632
633 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
634 const void *opt, const void *end)
635 {
636 uint16_t otype, olen;
637 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
638 dhcpv6_for_each_option(opt, end, otype, olen, odata)
639 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
640 odata[0] == DHCPV6_MSG_RENEW ||
641 odata[0] == DHCPV6_MSG_INFO_REQ))
642 msg = odata[0];
643
644 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
645 return msg;
646 }
647
648
649 // Collect all advertised servers
650 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
651 const void *opt, const void *end)
652 {
653 uint16_t olen, otype;
654 uint8_t *odata, pref = 0;
655 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
656 DHCPV6_SOL_MAX_RT,
657 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
658 bool have_na = false;
659 int have_pd = 0;
660
661 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
662 if (orig == DHCPV6_MSG_SOLICIT &&
663 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
664 olen > sizeof(struct dhcpv6_ia_hdr)) {
665 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
666 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
667 }
668
669 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
670 memcpy(cand.duid, odata, olen);
671 cand.duid_len = olen;
672 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
673 int error = ((int)odata[0] << 8 | (int)odata[1]);
674
675 switch (error) {
676 case DHCPV6_NoPrefixAvail:
677 // Status code on global level
678 cand.preference -= 2000;
679 break;
680
681 default :
682 break;
683 }
684 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
685 cand.preference >= 0) {
686 cand.preference = pref = odata[0];
687 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
688 cand.wants_reconfigure = true;
689 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
690 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
691 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
692 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
693 cand.sol_max_rt = sol_max_rt;
694 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
695 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
696 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
697 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
698 cand.inf_max_rt = inf_max_rt;
699 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
700 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
701 uint8_t *oend = odata + olen, *d;
702 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
703 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
704 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
705 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
706 have_pd = p->prefix;
707 }
708 }
709 } else if (otype == DHCPV6_OPT_IA_NA) {
710 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
711 uint8_t *oend = odata + olen, *d;
712 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
713 if (otype == DHCPV6_OPT_IA_ADDR)
714 have_na = true;
715 }
716 }
717
718 if ((!have_na && na_mode == IA_MODE_FORCE) ||
719 (!have_pd && pd_mode == IA_MODE_FORCE)) {
720 /*
721 * RFC7083 states to process the SOL_MAX_RT and
722 * INF_MAX_RT options even if the DHCPv6 server
723 * did not propose any IA_NA and/or IA_PD
724 */
725 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
726 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
727 return -1;
728 }
729
730 if (na_mode != IA_MODE_NONE && !have_na) {
731 cand.has_noaddravail = true;
732 cand.preference -= 1000;
733 }
734
735 if (pd_mode != IA_MODE_NONE) {
736 if (have_pd)
737 cand.preference += 2000 + (128 - have_pd);
738 else
739 cand.preference -= 2000;
740 }
741
742 if (cand.duid_len > 0) {
743 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
744 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
745 dhcpv6_add_server_cand(&cand);
746 }
747
748 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
749 }
750
751
752 static int dhcpv6_commit_advert(void)
753 {
754 return dhcpv6_promote_server_cand();
755 }
756
757
758 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
759 const void *opt, const void *end)
760 {
761 dhcpv6_handle_advert(orig, rc, opt, end);
762 if (dhcpv6_commit_advert() < 0)
763 return -1;
764
765 return dhcpv6_handle_reply(orig, rc, opt, end);
766 }
767
768
769 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
770 const void *opt, const void *end)
771 {
772 uint8_t *odata;
773 uint16_t otype, olen;
774 uint32_t refresh = UINT32_MAX;
775 int ret = 1;
776 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
777
778 odhcp6c_expire();
779
780 if (orig == DHCPV6_MSG_UNKNOWN) {
781 static time_t last_update = 0;
782 time_t now = odhcp6c_get_milli_time() / 1000;
783
784 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
785 last_update = now;
786
787 t1 -= elapsed;
788 t2 -= elapsed;
789 t3 -= elapsed;
790
791 if (t1 < 0)
792 t1 = 0;
793
794 if (t2 < 0)
795 t2 = 0;
796
797 if (t3 < 0)
798 t3 = 0;
799 }
800
801 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
802 // Delete NA and PD we have in the state from the Advert
803 odhcp6c_clear_state(STATE_IA_NA);
804 odhcp6c_clear_state(STATE_IA_PD);
805 }
806
807 if (opt) {
808 odhcp6c_clear_state(STATE_DNS);
809 odhcp6c_clear_state(STATE_SEARCH);
810 odhcp6c_clear_state(STATE_SNTP_IP);
811 odhcp6c_clear_state(STATE_SNTP_FQDN);
812 odhcp6c_clear_state(STATE_SIP_IP);
813 odhcp6c_clear_state(STATE_SIP_FQDN);
814 odhcp6c_clear_state(STATE_AFTR_NAME);
815 }
816
817 // Parse and find all matching IAs
818 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
819 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
820 && olen > sizeof(struct dhcpv6_ia_hdr)) {
821 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
822
823 // Test ID
824 if (ia_hdr->iaid != 1)
825 continue;
826
827 uint16_t code = DHCPV6_Success;
828 uint16_t stype, slen;
829 uint8_t *sdata;
830 // Get and handle status code
831 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
832 stype, slen, sdata) {
833 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
834 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
835 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
836
837 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
838
839 if (code == DHCPV6_Success)
840 continue;
841
842 dhcpv6_handle_ia_status_code(orig, ia_hdr,
843 code, mdata, mlen, handled_status_codes, &ret);
844
845
846 if (ret > 0)
847 return ret;
848 break;
849 }
850 }
851
852 if (code != DHCPV6_Success)
853 continue;
854
855 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
856 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
857 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
858 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
859 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
860
861 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
862 }
863 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
864 if (olen % 16 == 0)
865 odhcp6c_add_state(STATE_DNS, odata, olen);
866 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
867 odhcp6c_add_state(STATE_SEARCH, odata, olen);
868 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
869 uint16_t stype, slen;
870 uint8_t *sdata;
871 // Test status and bail if error
872 dhcpv6_for_each_option(odata, odata + olen,
873 stype, slen, sdata) {
874 if (slen == 16 && (stype == NTP_MC_ADDR ||
875 stype == NTP_SRV_ADDR))
876 odhcp6c_add_state(STATE_SNTP_IP,
877 sdata, slen);
878 else if (slen > 0 && stype == NTP_SRV_FQDN)
879 odhcp6c_add_state(STATE_SNTP_FQDN,
880 sdata, slen);
881 }
882 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
883 if (olen == 16)
884 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
885 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
886 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
887 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
888 refresh = ntohl(*((uint32_t*)odata));
889 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
890 sizeof(struct dhcpv6_auth_reconfigure)) {
891 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
892 if (r->protocol == 3 && r->algorithm == 1 &&
893 r->reconf_type == 1)
894 memcpy(reconf_key, r->key, sizeof(r->key));
895 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
896 size_t cur_len;
897 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
898 if (cur_len == 0)
899 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
900 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
901 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
902 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
903 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
904 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
905 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
906 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
907 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
908 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
909 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
910 }else if (otype != DHCPV6_OPT_CLIENTID &&
911 otype != DHCPV6_OPT_SERVERID) {
912 odhcp6c_add_state(STATE_CUSTOM_OPTS,
913 &odata[-4], olen + 4);
914 }
915 }
916
917 if (orig != DHCPV6_MSG_INFO_REQ) {
918 // Update refresh timers if no fatal status code was received
919 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
920 switch (orig) {
921 case DHCPV6_MSG_RENEW:
922 // Send further renews if T1 is not set
923 if (!t1)
924 ret = -1;
925 break;
926 case DHCPV6_MSG_REBIND:
927 // Send further rebinds if T1 and T2 is not set
928 if (!t1 && !t2)
929 ret = -1;
930 break;
931
932 case DHCPV6_MSG_REQUEST:
933 // All server candidates can be cleared if not yet bound
934 if (!odhcp6c_is_bound())
935 dhcpv6_clear_all_server_cand();
936
937 default :
938 break;
939 }
940 }
941 }
942 else if (ret > 0) {
943 // All server candidates can be cleared if not yet bound
944 if (!odhcp6c_is_bound())
945 dhcpv6_clear_all_server_cand();
946
947 t1 = refresh;
948 }
949
950 return ret;
951 }
952
953
954 static int dhcpv6_parse_ia(void *opt, void *end)
955 {
956 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
957 int parsed_ia = 0;
958 uint32_t t1, t2;
959 uint16_t otype, olen;
960 uint8_t *odata;
961
962 t1 = ntohl(ia_hdr->t1);
963 t2 = ntohl(ia_hdr->t2);
964
965 if (t1 > t2)
966 return 0;
967
968 // Update address IA
969 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
970 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
971 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
972
973 if (otype == DHCPV6_OPT_IA_PREFIX) {
974 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
975 if (olen + 4U < sizeof(*prefix))
976 continue;
977
978 entry.valid = ntohl(prefix->valid);
979 entry.preferred = ntohl(prefix->preferred);
980
981 if (entry.preferred > entry.valid)
982 continue;
983
984 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
985 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
986 if (entry.t1 > entry.t2)
987 entry.t1 = entry.t2;
988
989 entry.length = prefix->prefix;
990 entry.target = prefix->addr;
991 uint16_t stype, slen;
992 uint8_t *sdata;
993
994 #ifdef EXT_PREFIX_CLASS
995 // Find prefix class, if any
996 dhcpv6_for_each_option(&prefix[1], odata + olen,
997 stype, slen, sdata)
998 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
999 entry.class = sdata[0] << 8 | sdata[1];
1000 #endif
1001
1002 // Parse PD-exclude
1003 bool ok = true;
1004 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1005 odata + olen, stype, slen, sdata) {
1006 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1007 continue;
1008
1009 uint8_t elen = sdata[0];
1010 if (elen > 64)
1011 elen = 64;
1012
1013 if (elen <= 32 || elen <= entry.length) {
1014 ok = false;
1015 continue;
1016 }
1017
1018
1019 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1020 if (slen <= bytes) {
1021 ok = false;
1022 continue;
1023 }
1024
1025 uint32_t exclude = 0;
1026 do {
1027 exclude = exclude << 8 | sdata[bytes];
1028 } while (--bytes);
1029
1030 exclude >>= 8 - ((elen - entry.length) % 8);
1031 exclude <<= 64 - elen;
1032
1033 // Abusing router & priority fields for exclusion
1034 entry.router = entry.target;
1035 entry.router.s6_addr32[1] |= htonl(exclude);
1036 entry.priority = elen;
1037 }
1038
1039 if (ok) {
1040 odhcp6c_update_entry(STATE_IA_PD, &entry);
1041 parsed_ia++;
1042 }
1043
1044 entry.priority = 0;
1045 memset(&entry.router, 0, sizeof(entry.router));
1046 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1047 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1048 if (olen + 4U < sizeof(*addr))
1049 continue;
1050
1051 entry.preferred = ntohl(addr->preferred);
1052 entry.valid = ntohl(addr->valid);
1053
1054 if (entry.preferred > entry.valid)
1055 continue;
1056
1057 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1058 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1059 if (entry.t1 > entry.t2)
1060 entry.t1 = entry.t2;
1061
1062 entry.length = 128;
1063 entry.target = addr->addr;
1064
1065 #ifdef EXT_PREFIX_CLASS
1066 uint16_t stype, slen;
1067 uint8_t *sdata;
1068 // Find prefix class, if any
1069 dhcpv6_for_each_option(&addr[1], odata + olen,
1070 stype, slen, sdata)
1071 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1072 entry.class = sdata[0] << 8 | sdata[1];
1073 #endif
1074
1075 odhcp6c_update_entry(STATE_IA_NA, &entry);
1076 parsed_ia++;
1077 }
1078 }
1079 return parsed_ia;
1080 }
1081
1082
1083 static int dhcpv6_calc_refresh_timers(void)
1084 {
1085 struct odhcp6c_entry *e;
1086 size_t ia_na_entries, ia_pd_entries, i;
1087 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1088
1089 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1090 ia_na_entries /= sizeof(*e);
1091 for (i = 0; i < ia_na_entries; i++) {
1092 if (e[i].t1 < l_t1)
1093 l_t1 = e[i].t1;
1094
1095 if (e[i].t2 < l_t2)
1096 l_t2 = e[i].t2;
1097
1098 if (e[i].valid > l_t3)
1099 l_t3 = e[i].valid;
1100 }
1101
1102 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1103 ia_pd_entries /= sizeof(*e);
1104 for (i = 0; i < ia_pd_entries; i++) {
1105 if (e[i].t1 < l_t1)
1106 l_t1 = e[i].t1;
1107
1108 if (e[i].t2 < l_t2)
1109 l_t2 = e[i].t2;
1110
1111 if (e[i].valid > l_t3)
1112 l_t3 = e[i].valid;
1113 }
1114
1115 if (ia_pd_entries || ia_na_entries) {
1116 t1 = l_t1;
1117 t2 = l_t2;
1118 t3 = l_t3;
1119 } else {
1120 t1 = 600;
1121 }
1122
1123 return (int)(ia_pd_entries + ia_na_entries);
1124 }
1125
1126
1127 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1128 const void *status_msg, const int len)
1129 {
1130 uint8_t buf[len + 3];
1131
1132 memset(buf, 0, sizeof(buf));
1133 if (len) {
1134 buf[0] = '(';
1135 memcpy(&buf[1], status_msg, len);
1136 buf[len + 1] = ')';
1137 }
1138
1139 syslog(LOG_WARNING, "Server returned %s status %i %s",
1140 scope, code, buf);
1141 }
1142
1143
1144 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1145 const uint16_t code, const void *status_msg, const int len,
1146 int *ret)
1147 {
1148 dhcpv6_log_status_code(code, "message", status_msg, len);
1149
1150 switch (code) {
1151 case DHCPV6_UnspecFail:
1152 // Generic failure
1153 *ret = 0;
1154 break;
1155
1156 case DHCPV6_UseMulticast:
1157 // TODO handle multicast status code
1158 break;
1159
1160 case DHCPV6_NoAddrsAvail:
1161 case DHCPV6_NoPrefixAvail:
1162 if (orig == DHCPV6_MSG_REQUEST)
1163 *ret = 0; // Failure
1164 break;
1165
1166 default:
1167 break;
1168 }
1169 }
1170
1171
1172 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1173 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1174 const void *status_msg, const int len,
1175 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1176 {
1177 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1178 "IA_NA" : "IA_PD", status_msg, len);
1179
1180 switch (code) {
1181 case DHCPV6_NoBinding:
1182 switch (orig) {
1183 case DHCPV6_MSG_RENEW:
1184 case DHCPV6_MSG_REBIND:
1185 if ((*ret > 0) && !handled_status_codes[code])
1186 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1187 break;
1188
1189 default:
1190 break;
1191 }
1192 break;
1193
1194 case DHCPV6_NoAddrsAvail:
1195 case DHCPV6_NoPrefixAvail:
1196 switch (orig) {
1197 case DHCPV6_MSG_REQUEST:
1198 if (*ret != 0)
1199 *ret = 0;
1200 break;
1201 default:
1202 break;
1203 }
1204 break;
1205
1206 case DHCPV6_NotOnLink:
1207 // TODO handle not onlink in case of confirm
1208 break;
1209
1210 default:
1211 break;
1212 }
1213 }
1214
1215 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1216 {
1217 size_t cand_len, i;
1218 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1219
1220 // Remove identical duid server candidate
1221 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1222 if (cand->duid_len == c[i].duid_len &&
1223 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1224 free(c[i].ia_na);
1225 free(c[i].ia_pd);
1226 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1227 break;
1228 }
1229 }
1230
1231 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1232 i < cand_len / sizeof(*c); ++i) {
1233 if (c[i].preference < cand->preference)
1234 break;
1235 }
1236
1237 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1238 }
1239
1240 static void dhcpv6_clear_all_server_cand(void)
1241 {
1242 size_t cand_len, i;
1243 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1244
1245 // Server candidates need deep delete for IA_NA/IA_PD
1246 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1247 free(c[i].ia_na);
1248 free(c[i].ia_pd);
1249 }
1250 odhcp6c_clear_state(STATE_SERVER_CAND);
1251 }
1252
1253 int dhcpv6_promote_server_cand(void)
1254 {
1255 size_t cand_len;
1256 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1257 uint16_t hdr[2];
1258 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1259 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1260
1261 // Clear lingering candidate state info
1262 odhcp6c_clear_state(STATE_SERVER_ID);
1263 odhcp6c_clear_state(STATE_IA_NA);
1264 odhcp6c_clear_state(STATE_IA_PD);
1265
1266 if (!cand_len)
1267 return -1;
1268
1269 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1270 na_mode = IA_MODE_NONE;
1271
1272 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1273 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1274
1275 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1276 }
1277
1278 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1279 hdr[1] = htons(cand->duid_len);
1280 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1281 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1282 accept_reconfig = cand->wants_reconfigure;
1283 if (cand->ia_na_len) {
1284 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1285 free(cand->ia_na);
1286 if (na_mode != IA_MODE_NONE)
1287 ret = DHCPV6_STATEFUL;
1288 }
1289 if (cand->ia_pd_len) {
1290 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1291 free(cand->ia_pd);
1292 if (request_prefix)
1293 ret = DHCPV6_STATEFUL;
1294 }
1295
1296 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1297 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1298
1299 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1300
1301 return ret;
1302 }
Openwrt DHCPv6 Client