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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 <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, bool strict_options, 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 if (!strict_options) {
162 uint16_t oro[] = {
163 htons(DHCPV6_OPT_SIP_SERVER_D),
164 htons(DHCPV6_OPT_SIP_SERVER_A),
165 htons(DHCPV6_OPT_DNS_SERVERS),
166 htons(DHCPV6_OPT_DNS_DOMAIN),
167 htons(DHCPV6_OPT_SNTP_SERVERS),
168 htons(DHCPV6_OPT_NTP_SERVER),
169 htons(DHCPV6_OPT_AFTR_NAME),
170 htons(DHCPV6_OPT_PD_EXCLUDE),
171 htons(DHCPV6_OPT_SOL_MAX_RT),
172 htons(DHCPV6_OPT_INF_MAX_RT),
173 #ifdef EXT_PREFIX_CLASS
174 htons(DHCPV6_OPT_PREFIX_CLASS),
175 #endif
176 };
177 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
178 }
179
180 // Configure IPv6-options
181 int val = 1;
182 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
183 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
184 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
185 val = 0;
186 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
187 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
188
189 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
190 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
191 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
192 return -1;
193
194 return 0;
195 }
196
197
198 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
199 {
200 na_mode = na;
201 pd_mode = pd;
202 }
203
204
205 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
206 {
207 // Build FQDN
208 char fqdn_buf[256];
209 gethostname(fqdn_buf, sizeof(fqdn_buf));
210 struct {
211 uint16_t type;
212 uint16_t len;
213 uint8_t flags;
214 uint8_t data[256];
215 } fqdn;
216 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
217 sizeof(fqdn.data), NULL, NULL);
218 fqdn.type = htons(DHCPV6_OPT_FQDN);
219 fqdn.len = htons(fqdn_len - 4);
220 fqdn.flags = 0;
221
222
223 // Build Client ID
224 size_t cl_id_len;
225 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
226
227 // Get Server ID
228 size_t srv_id_len;
229 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
230
231 // Build IA_PDs
232 size_t ia_pd_entries, ia_pd_len = 0;
233 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
234 ia_pd_entries /= sizeof(*e);
235 struct dhcpv6_ia_hdr hdr_ia_pd = {
236 htons(DHCPV6_OPT_IA_PD),
237 htons(sizeof(hdr_ia_pd) - 4),
238 1, 0, 0
239 };
240
241
242 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
243 for (size_t i = 0; i < ia_pd_entries; ++i) {
244 uint8_t ex_len = 0;
245 if (e[i].priority > 0)
246 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
247
248 struct dhcpv6_ia_prefix p = {
249 .type = htons(DHCPV6_OPT_IA_PREFIX),
250 .len = htons(sizeof(p) - 4U + ex_len),
251 .prefix = e[i].length,
252 .addr = e[i].target
253 };
254
255 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
256 ia_pd_len += sizeof(p);
257
258 if (ex_len) {
259 ia_pd[ia_pd_len++] = 0;
260 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
261 ia_pd[ia_pd_len++] = 0;
262 ia_pd[ia_pd_len++] = ex_len - 4;
263 ia_pd[ia_pd_len++] = e[i].priority;
264
265 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
266 excl >>= (64 - e[i].priority);
267 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
268
269 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
270 ia_pd[ia_pd_len + i] = excl & 0xff;
271 ia_pd_len += ex_len - 5;
272 }
273 }
274
275 struct dhcpv6_ia_prefix pref = {
276 .type = htons(DHCPV6_OPT_IA_PREFIX),
277 .len = htons(25), .prefix = request_prefix
278 };
279 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
280 ia_pd = (uint8_t*)&pref;
281 ia_pd_len = sizeof(pref);
282 }
283 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
284
285 // Build IA_NAs
286 size_t ia_na_entries, ia_na_len = 0;
287 void *ia_na = NULL;
288 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
289 ia_na_entries /= sizeof(*e);
290
291 struct dhcpv6_ia_hdr hdr_ia_na = {
292 htons(DHCPV6_OPT_IA_NA),
293 htons(sizeof(hdr_ia_na) - 4),
294 1, 0, 0
295 };
296
297 struct dhcpv6_ia_addr pa[ia_na_entries];
298 for (size_t i = 0; i < ia_na_entries; ++i) {
299 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
300 pa[i].len = htons(sizeof(pa[i]) - 4U);
301 pa[i].addr = e[i].target;
302 pa[i].preferred = 0;
303 pa[i].valid = 0;
304 }
305
306 ia_na = pa;
307 ia_na_len = sizeof(pa);
308 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
309
310 // Reconfigure Accept
311 struct {
312 uint16_t type;
313 uint16_t length;
314 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
315
316 // Request Information Refresh
317 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
318
319 // Prepare Header
320 size_t oro_len;
321 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
322 struct {
323 uint8_t type;
324 uint8_t trid[3];
325 uint16_t elapsed_type;
326 uint16_t elapsed_len;
327 uint16_t elapsed_value;
328 uint16_t oro_type;
329 uint16_t oro_len;
330 } hdr = {
331 type, {trid[0], trid[1], trid[2]},
332 htons(DHCPV6_OPT_ELAPSED), htons(2),
333 htons((ecs > 0xffff) ? 0xffff : ecs),
334 htons(DHCPV6_OPT_ORO), htons(oro_len),
335 };
336
337 struct iovec iov[] = {
338 {&hdr, sizeof(hdr)},
339 {oro, oro_len},
340 {&oro_refresh, 0},
341 {cl_id, cl_id_len},
342 {srv_id, srv_id_len},
343 {&reconf_accept, sizeof(reconf_accept)},
344 {&fqdn, fqdn_len},
345 {&hdr_ia_na, sizeof(hdr_ia_na)},
346 {ia_na, ia_na_len},
347 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
348 {ia_pd, ia_pd_len},
349 };
350
351 size_t cnt = ARRAY_SIZE(iov);
352 if (type == DHCPV6_MSG_INFO_REQ) {
353 cnt = 5;
354 iov[2].iov_len = sizeof(oro_refresh);
355 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
356 } else if (!request_prefix) {
357 cnt = 9;
358 }
359
360 // Disable IAs if not used
361 if (type != DHCPV6_MSG_SOLICIT) {
362 iov[5].iov_len = 0;
363 if (ia_na_len == 0)
364 iov[7].iov_len = 0;
365 if (ia_pd_len == 0)
366 iov[9].iov_len = 0;
367 }
368
369 if (na_mode == IA_MODE_NONE)
370 iov[7].iov_len = 0;
371
372 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
373 0, ALL_DHCPV6_RELAYS, ifindex};
374 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
375
376 sendmsg(sock, &msg, 0);
377 }
378
379
380 static int64_t dhcpv6_rand_delay(int64_t time)
381 {
382 int random;
383 odhcp6c_random(&random, sizeof(random));
384 return (time * ((int64_t)random % 1000LL)) / 10000LL;
385 }
386
387
388 int dhcpv6_request(enum dhcpv6_msg type)
389 {
390 uint8_t rc = 0;
391 uint64_t timeout = UINT32_MAX;
392 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
393
394 if (retx->delay) {
395 struct timespec ts = {0, 0};
396 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
397 nanosleep(&ts, NULL);
398 }
399
400 if (type == DHCPV6_MSG_UNKNOWN)
401 timeout = t1;
402 else if (type == DHCPV6_MSG_RENEW)
403 timeout = (t2 > t1) ? t2 - t1 : 0;
404 else if (type == DHCPV6_MSG_REBIND)
405 timeout = (t3 > t2) ? t3 - t2 : 0;
406
407 if (timeout == 0)
408 return -1;
409
410 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
411 retx->name, (unsigned long long)timeout, retx->max_rc);
412
413 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
414
415 // Generate transaction ID
416 uint8_t trid[3] = {0, 0, 0};
417 if (type != DHCPV6_MSG_UNKNOWN)
418 odhcp6c_random(trid, sizeof(trid));
419 ssize_t len = -1;
420 int64_t rto = 0;
421
422 do {
423 if (rto == 0) {
424 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
425
426 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
427 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
428 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
429
430 rto = (retx->init_timeo * 1000 + delay);
431 }
432 else
433 rto = (2 * rto + dhcpv6_rand_delay(rto));
434
435 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
436 rto = retx->max_timeo * 1000 +
437 dhcpv6_rand_delay(retx->max_timeo * 1000);
438
439 // Calculate end for this round and elapsed time
440 uint64_t round_end = round_start + rto;
441 elapsed = round_start - start;
442
443 // Don't wait too long
444 if (round_end - start > timeout * 1000)
445 round_end = timeout * 1000 + start;
446
447 // Built and send package
448 if (type != DHCPV6_MSG_UNKNOWN) {
449 if (type != DHCPV6_MSG_SOLICIT)
450 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
451 retx->name, (unsigned long long)elapsed, rc);
452 dhcpv6_send(type, trid, elapsed / 10);
453 rc++;
454 }
455
456 // Receive rounds
457 for (; len < 0 && (round_start < round_end);
458 round_start = odhcp6c_get_milli_time()) {
459 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
460 struct iovec iov = {buf, sizeof(buf)};
461 struct msghdr msg = {NULL, 0, &iov, 1,
462 cmsg_buf, sizeof(cmsg_buf), 0};
463 struct in6_pktinfo *pktinfo = NULL;
464
465 // Check for pending signal
466 if (odhcp6c_signal_process())
467 return -1;
468
469 // Set timeout for receiving
470 uint64_t t = round_end - round_start;
471 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
472 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
473 &timeout, sizeof(timeout));
474
475 // Receive cycle
476 len = recvmsg(sock, &msg, 0);
477 if (len < 0)
478 continue;
479
480 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
481 ch = CMSG_NXTHDR(&msg, ch)) {
482 if (ch->cmsg_level == SOL_IPV6 &&
483 ch->cmsg_type == IPV6_PKTINFO) {
484 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
485 break;
486 }
487 }
488
489 if (pktinfo == NULL) {
490 len = -1;
491 continue;
492 }
493
494 if (!dhcpv6_response_is_valid(buf, len, trid,
495 type, &pktinfo->ipi6_addr)) {
496 len = -1;
497 continue;
498 }
499
500 uint8_t *opt = &buf[4];
501 uint8_t *opt_end = opt + len - 4;
502
503 round_start = odhcp6c_get_milli_time();
504 elapsed = round_start - start;
505 syslog(LOG_NOTICE, "Got a valid reply after "
506 "%llums", (unsigned long long)elapsed);
507
508 if (retx->handler_reply)
509 len = retx->handler_reply(type, rc, opt, opt_end);
510
511 if (len > 0 && round_end - round_start > 1000)
512 round_end = 1000 + round_start;
513 }
514
515 // Allow
516 if (retx->handler_finish)
517 len = retx->handler_finish();
518 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
519
520 return len;
521 }
522
523 // Message validation checks according to RFC3315 chapter 15
524 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
525 const uint8_t transaction[3], enum dhcpv6_msg type,
526 const struct in6_addr *daddr)
527 {
528 const struct dhcpv6_header *rep = buf;
529 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
530 transaction, sizeof(rep->tr_id)))
531 return false; // Invalid reply
532
533 if (type == DHCPV6_MSG_SOLICIT) {
534 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
535 rep->msg_type != DHCPV6_MSG_REPLY)
536 return false;
537 } else if (type == DHCPV6_MSG_UNKNOWN) {
538 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
539 return false;
540 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
541 return false;
542 }
543
544 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
545 rcmsg = DHCPV6_MSG_UNKNOWN;
546 uint16_t otype, olen = UINT16_MAX;
547 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
548 ia_present = false, options_valid = true;
549
550 size_t client_id_len, server_id_len;
551 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
552 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
553
554 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
555 if (otype == DHCPV6_OPT_CLIENTID) {
556 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
557 &odata[-4], client_id, client_id_len);
558 } else if (otype == DHCPV6_OPT_SERVERID) {
559 if (server_id_len)
560 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
561 &odata[-4], server_id, server_id_len);
562 else
563 serverid_ok = true;
564 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
565 sizeof(struct dhcpv6_auth_reconfigure)) {
566 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
567 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
568 continue;
569
570 md5_ctx_t md5;
571 uint8_t serverhash[16], secretbytes[16], hash[16];
572 memcpy(serverhash, r->key, sizeof(serverhash));
573 memset(r->key, 0, sizeof(r->key));
574 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
575
576 for (size_t i = 0; i < sizeof(secretbytes); ++i)
577 secretbytes[i] ^= 0x36;
578
579 md5_begin(&md5);
580 md5_hash(secretbytes, sizeof(secretbytes), &md5);
581 md5_hash(buf, len, &md5);
582 md5_end(hash, &md5);
583
584 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
585 secretbytes[i] ^= 0x36;
586 secretbytes[i] ^= 0x5c;
587 }
588
589 md5_begin(&md5);
590 md5_hash(secretbytes, sizeof(secretbytes), &md5);
591 md5_hash(hash, 16, &md5);
592 md5_end(hash, &md5);
593
594 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
595 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
596 rcmsg = odata[0];
597 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
598 ia_present = true;
599 if (olen < sizeof(struct dhcpv6_ia_hdr))
600 options_valid = false;
601 }
602 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
603 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
604 // Options are not allowed on global level
605 options_valid = false;
606 }
607 }
608
609 if (!options_valid || ((odata + olen) > end))
610 return false;
611
612 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
613 return false;
614
615 if (rep->msg_type == DHCPV6_MSG_RECONF) {
616 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
617 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
618 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
619 return false;
620 }
621
622 return clientid_ok && serverid_ok;
623 }
624
625
626 int dhcpv6_poll_reconfigure(void)
627 {
628 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
629 if (ret != -1)
630 ret = dhcpv6_request(ret);
631
632 return ret;
633 }
634
635
636 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
637 const void *opt, const void *end)
638 {
639 uint16_t otype, olen;
640 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
641 dhcpv6_for_each_option(opt, end, otype, olen, odata)
642 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
643 odata[0] == DHCPV6_MSG_RENEW ||
644 odata[0] == DHCPV6_MSG_INFO_REQ))
645 msg = odata[0];
646
647 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
648 return msg;
649 }
650
651
652 // Collect all advertised servers
653 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
654 const void *opt, const void *end)
655 {
656 uint16_t olen, otype;
657 uint8_t *odata, pref = 0;
658 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
659 DHCPV6_SOL_MAX_RT,
660 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
661 bool have_na = false;
662 int have_pd = 0;
663
664 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
665 if (orig == DHCPV6_MSG_SOLICIT &&
666 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
667 olen > sizeof(struct dhcpv6_ia_hdr)) {
668 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
669 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
670 }
671
672 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
673 memcpy(cand.duid, odata, olen);
674 cand.duid_len = olen;
675 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
676 int error = ((int)odata[0] << 8 | (int)odata[1]);
677
678 switch (error) {
679 case DHCPV6_NoPrefixAvail:
680 // Status code on global level
681 cand.preference -= 2000;
682 break;
683
684 default :
685 break;
686 }
687 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
688 cand.preference >= 0) {
689 cand.preference = pref = odata[0];
690 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
691 cand.wants_reconfigure = true;
692 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
693 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
694 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
695 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
696 cand.sol_max_rt = sol_max_rt;
697 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
698 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
699 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
700 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
701 cand.inf_max_rt = inf_max_rt;
702 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
703 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
704 uint8_t *oend = odata + olen, *d;
705 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
706 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
707 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
708 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
709 have_pd = p->prefix;
710 }
711 }
712 } else if (otype == DHCPV6_OPT_IA_NA) {
713 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
714 uint8_t *oend = odata + olen, *d;
715 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
716 if (otype == DHCPV6_OPT_IA_ADDR)
717 have_na = true;
718 }
719 }
720
721 if ((!have_na && na_mode == IA_MODE_FORCE) ||
722 (!have_pd && pd_mode == IA_MODE_FORCE)) {
723 /*
724 * RFC7083 states to process the SOL_MAX_RT and
725 * INF_MAX_RT options even if the DHCPv6 server
726 * did not propose any IA_NA and/or IA_PD
727 */
728 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
729 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
730 return -1;
731 }
732
733 if (na_mode != IA_MODE_NONE && !have_na) {
734 cand.has_noaddravail = true;
735 cand.preference -= 1000;
736 }
737
738 if (pd_mode != IA_MODE_NONE) {
739 if (have_pd)
740 cand.preference += 2000 + (128 - have_pd);
741 else
742 cand.preference -= 2000;
743 }
744
745 if (cand.duid_len > 0) {
746 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
747 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
748 dhcpv6_add_server_cand(&cand);
749 }
750
751 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
752 }
753
754
755 static int dhcpv6_commit_advert(void)
756 {
757 return dhcpv6_promote_server_cand();
758 }
759
760
761 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
762 const void *opt, const void *end)
763 {
764 dhcpv6_handle_advert(orig, rc, opt, end);
765 if (dhcpv6_commit_advert() < 0)
766 return -1;
767
768 return dhcpv6_handle_reply(orig, rc, opt, end);
769 }
770
771
772 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
773 const void *opt, const void *end)
774 {
775 uint8_t *odata;
776 uint16_t otype, olen;
777 uint32_t refresh = UINT32_MAX;
778 int ret = 1;
779 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
780
781 odhcp6c_expire();
782
783 if (orig == DHCPV6_MSG_UNKNOWN) {
784 static time_t last_update = 0;
785 time_t now = odhcp6c_get_milli_time() / 1000;
786
787 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
788 last_update = now;
789
790 t1 -= elapsed;
791 t2 -= elapsed;
792 t3 -= elapsed;
793
794 if (t1 < 0)
795 t1 = 0;
796
797 if (t2 < 0)
798 t2 = 0;
799
800 if (t3 < 0)
801 t3 = 0;
802 }
803
804 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
805 // Delete NA and PD we have in the state from the Advert
806 odhcp6c_clear_state(STATE_IA_NA);
807 odhcp6c_clear_state(STATE_IA_PD);
808 }
809
810 if (opt) {
811 odhcp6c_clear_state(STATE_DNS);
812 odhcp6c_clear_state(STATE_SEARCH);
813 odhcp6c_clear_state(STATE_SNTP_IP);
814 odhcp6c_clear_state(STATE_NTP_IP);
815 odhcp6c_clear_state(STATE_NTP_FQDN);
816 odhcp6c_clear_state(STATE_SIP_IP);
817 odhcp6c_clear_state(STATE_SIP_FQDN);
818 odhcp6c_clear_state(STATE_AFTR_NAME);
819 }
820
821 // Parse and find all matching IAs
822 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
823 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
824 && olen > sizeof(struct dhcpv6_ia_hdr)) {
825 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
826
827 // Test ID
828 if (ia_hdr->iaid != 1)
829 continue;
830
831 uint16_t code = DHCPV6_Success;
832 uint16_t stype, slen;
833 uint8_t *sdata;
834 // Get and handle status code
835 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
836 stype, slen, sdata) {
837 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
838 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
839 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
840
841 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
842
843 if (code == DHCPV6_Success)
844 continue;
845
846 dhcpv6_handle_ia_status_code(orig, ia_hdr,
847 code, mdata, mlen, handled_status_codes, &ret);
848
849
850 if (ret > 0)
851 return ret;
852 break;
853 }
854 }
855
856 if (code != DHCPV6_Success)
857 continue;
858
859 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
860 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
861 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
862 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
863 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
864
865 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
866 }
867 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
868 if (olen % 16 == 0)
869 odhcp6c_add_state(STATE_DNS, odata, olen);
870 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
871 odhcp6c_add_state(STATE_SEARCH, odata, olen);
872 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
873 if (olen % 16 == 0)
874 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
875 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
876 uint16_t stype, slen;
877 uint8_t *sdata;
878 // Test status and bail if error
879 dhcpv6_for_each_option(odata, odata + olen,
880 stype, slen, sdata) {
881 if (slen == 16 && (stype == NTP_MC_ADDR ||
882 stype == NTP_SRV_ADDR))
883 odhcp6c_add_state(STATE_NTP_IP,
884 sdata, slen);
885 else if (slen > 0 && stype == NTP_SRV_FQDN)
886 odhcp6c_add_state(STATE_NTP_FQDN,
887 sdata, slen);
888 }
889 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
890 if (olen == 16)
891 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
892 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
893 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
894 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
895 refresh = ntohl(*((uint32_t*)odata));
896 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
897 sizeof(struct dhcpv6_auth_reconfigure)) {
898 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
899 if (r->protocol == 3 && r->algorithm == 1 &&
900 r->reconf_type == 1)
901 memcpy(reconf_key, r->key, sizeof(r->key));
902 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
903 size_t cur_len;
904 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
905 if (cur_len == 0)
906 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
907 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
908 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
909 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
910 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
911 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
912 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
913 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
914 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
915 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
916 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
917 }else if (otype != DHCPV6_OPT_CLIENTID &&
918 otype != DHCPV6_OPT_SERVERID) {
919 odhcp6c_add_state(STATE_CUSTOM_OPTS,
920 &odata[-4], olen + 4);
921 }
922 }
923
924 if (orig != DHCPV6_MSG_INFO_REQ) {
925 // Update refresh timers if no fatal status code was received
926 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
927 switch (orig) {
928 case DHCPV6_MSG_RENEW:
929 // Send further renews if T1 is not set
930 if (!t1)
931 ret = -1;
932 break;
933 case DHCPV6_MSG_REBIND:
934 // Send further rebinds if T1 and T2 is not set
935 if (!t1 && !t2)
936 ret = -1;
937 break;
938
939 case DHCPV6_MSG_REQUEST:
940 // All server candidates can be cleared if not yet bound
941 if (!odhcp6c_is_bound())
942 dhcpv6_clear_all_server_cand();
943
944 default :
945 break;
946 }
947 }
948 }
949 else if (ret > 0) {
950 // All server candidates can be cleared if not yet bound
951 if (!odhcp6c_is_bound())
952 dhcpv6_clear_all_server_cand();
953
954 t1 = refresh;
955 }
956
957 return ret;
958 }
959
960
961 static int dhcpv6_parse_ia(void *opt, void *end)
962 {
963 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
964 int parsed_ia = 0;
965 uint32_t t1, t2;
966 uint16_t otype, olen;
967 uint8_t *odata;
968
969 t1 = ntohl(ia_hdr->t1);
970 t2 = ntohl(ia_hdr->t2);
971
972 if (t1 > t2)
973 return 0;
974
975 // Update address IA
976 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
977 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
978 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
979
980 if (otype == DHCPV6_OPT_IA_PREFIX) {
981 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
982 if (olen + 4U < sizeof(*prefix))
983 continue;
984
985 entry.valid = ntohl(prefix->valid);
986 entry.preferred = ntohl(prefix->preferred);
987
988 if (entry.preferred > entry.valid)
989 continue;
990
991 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
992 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
993 if (entry.t1 > entry.t2)
994 entry.t1 = entry.t2;
995
996 entry.length = prefix->prefix;
997 entry.target = prefix->addr;
998 uint16_t stype, slen;
999 uint8_t *sdata;
1000
1001 #ifdef EXT_PREFIX_CLASS
1002 // Find prefix class, if any
1003 dhcpv6_for_each_option(&prefix[1], odata + olen,
1004 stype, slen, sdata)
1005 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1006 entry.class = sdata[0] << 8 | sdata[1];
1007 #endif
1008
1009 // Parse PD-exclude
1010 bool ok = true;
1011 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1012 odata + olen, stype, slen, sdata) {
1013 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1014 continue;
1015
1016 uint8_t elen = sdata[0];
1017 if (elen > 64)
1018 elen = 64;
1019
1020 if (elen <= 32 || elen <= entry.length) {
1021 ok = false;
1022 continue;
1023 }
1024
1025
1026 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1027 if (slen <= bytes) {
1028 ok = false;
1029 continue;
1030 }
1031
1032 uint32_t exclude = 0;
1033 do {
1034 exclude = exclude << 8 | sdata[bytes];
1035 } while (--bytes);
1036
1037 exclude >>= 8 - ((elen - entry.length) % 8);
1038 exclude <<= 64 - elen;
1039
1040 // Abusing router & priority fields for exclusion
1041 entry.router = entry.target;
1042 entry.router.s6_addr32[1] |= htonl(exclude);
1043 entry.priority = elen;
1044 }
1045
1046 if (ok) {
1047 odhcp6c_update_entry(STATE_IA_PD, &entry);
1048 parsed_ia++;
1049 }
1050
1051 entry.priority = 0;
1052 memset(&entry.router, 0, sizeof(entry.router));
1053 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1054 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1055 if (olen + 4U < sizeof(*addr))
1056 continue;
1057
1058 entry.preferred = ntohl(addr->preferred);
1059 entry.valid = ntohl(addr->valid);
1060
1061 if (entry.preferred > entry.valid)
1062 continue;
1063
1064 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1065 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1066 if (entry.t1 > entry.t2)
1067 entry.t1 = entry.t2;
1068
1069 entry.length = 128;
1070 entry.target = addr->addr;
1071
1072 #ifdef EXT_PREFIX_CLASS
1073 uint16_t stype, slen;
1074 uint8_t *sdata;
1075 // Find prefix class, if any
1076 dhcpv6_for_each_option(&addr[1], odata + olen,
1077 stype, slen, sdata)
1078 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1079 entry.class = sdata[0] << 8 | sdata[1];
1080 #endif
1081
1082 odhcp6c_update_entry(STATE_IA_NA, &entry);
1083 parsed_ia++;
1084 }
1085 }
1086 return parsed_ia;
1087 }
1088
1089
1090 static int dhcpv6_calc_refresh_timers(void)
1091 {
1092 struct odhcp6c_entry *e;
1093 size_t ia_na_entries, ia_pd_entries, i;
1094 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1095
1096 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1097 ia_na_entries /= sizeof(*e);
1098 for (i = 0; i < ia_na_entries; i++) {
1099 if (e[i].t1 < l_t1)
1100 l_t1 = e[i].t1;
1101
1102 if (e[i].t2 < l_t2)
1103 l_t2 = e[i].t2;
1104
1105 if (e[i].valid > l_t3)
1106 l_t3 = e[i].valid;
1107 }
1108
1109 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1110 ia_pd_entries /= sizeof(*e);
1111 for (i = 0; i < ia_pd_entries; i++) {
1112 if (e[i].t1 < l_t1)
1113 l_t1 = e[i].t1;
1114
1115 if (e[i].t2 < l_t2)
1116 l_t2 = e[i].t2;
1117
1118 if (e[i].valid > l_t3)
1119 l_t3 = e[i].valid;
1120 }
1121
1122 if (ia_pd_entries || ia_na_entries) {
1123 t1 = l_t1;
1124 t2 = l_t2;
1125 t3 = l_t3;
1126 } else {
1127 t1 = 600;
1128 }
1129
1130 return (int)(ia_pd_entries + ia_na_entries);
1131 }
1132
1133
1134 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1135 const void *status_msg, const int len)
1136 {
1137 uint8_t buf[len + 3];
1138
1139 memset(buf, 0, sizeof(buf));
1140 if (len) {
1141 buf[0] = '(';
1142 memcpy(&buf[1], status_msg, len);
1143 buf[len + 1] = ')';
1144 }
1145
1146 syslog(LOG_WARNING, "Server returned %s status %i %s",
1147 scope, code, buf);
1148 }
1149
1150
1151 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1152 const uint16_t code, const void *status_msg, const int len,
1153 int *ret)
1154 {
1155 dhcpv6_log_status_code(code, "message", status_msg, len);
1156
1157 switch (code) {
1158 case DHCPV6_UnspecFail:
1159 // Generic failure
1160 *ret = 0;
1161 break;
1162
1163 case DHCPV6_UseMulticast:
1164 // TODO handle multicast status code
1165 break;
1166
1167 case DHCPV6_NoAddrsAvail:
1168 case DHCPV6_NoPrefixAvail:
1169 if (orig == DHCPV6_MSG_REQUEST)
1170 *ret = 0; // Failure
1171 break;
1172
1173 default:
1174 break;
1175 }
1176 }
1177
1178
1179 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1180 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1181 const void *status_msg, const int len,
1182 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1183 {
1184 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1185 "IA_NA" : "IA_PD", status_msg, len);
1186
1187 switch (code) {
1188 case DHCPV6_NoBinding:
1189 switch (orig) {
1190 case DHCPV6_MSG_RENEW:
1191 case DHCPV6_MSG_REBIND:
1192 if ((*ret > 0) && !handled_status_codes[code])
1193 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1194 break;
1195
1196 default:
1197 break;
1198 }
1199 break;
1200
1201 case DHCPV6_NoAddrsAvail:
1202 case DHCPV6_NoPrefixAvail:
1203 switch (orig) {
1204 case DHCPV6_MSG_REQUEST:
1205 if (*ret != 0)
1206 *ret = 0;
1207 break;
1208 default:
1209 break;
1210 }
1211 break;
1212
1213 case DHCPV6_NotOnLink:
1214 // TODO handle not onlink in case of confirm
1215 break;
1216
1217 default:
1218 break;
1219 }
1220 }
1221
1222 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1223 {
1224 size_t cand_len, i;
1225 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1226
1227 // Remove identical duid server candidate
1228 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1229 if (cand->duid_len == c[i].duid_len &&
1230 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1231 free(c[i].ia_na);
1232 free(c[i].ia_pd);
1233 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1234 break;
1235 }
1236 }
1237
1238 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1239 i < cand_len / sizeof(*c); ++i) {
1240 if (c[i].preference < cand->preference)
1241 break;
1242 }
1243
1244 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1245 }
1246
1247 static void dhcpv6_clear_all_server_cand(void)
1248 {
1249 size_t cand_len, i;
1250 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1251
1252 // Server candidates need deep delete for IA_NA/IA_PD
1253 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1254 free(c[i].ia_na);
1255 free(c[i].ia_pd);
1256 }
1257 odhcp6c_clear_state(STATE_SERVER_CAND);
1258 }
1259
1260 int dhcpv6_promote_server_cand(void)
1261 {
1262 size_t cand_len;
1263 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1264 uint16_t hdr[2];
1265 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1266 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1267
1268 // Clear lingering candidate state info
1269 odhcp6c_clear_state(STATE_SERVER_ID);
1270 odhcp6c_clear_state(STATE_IA_NA);
1271 odhcp6c_clear_state(STATE_IA_PD);
1272
1273 if (!cand_len)
1274 return -1;
1275
1276 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1277 na_mode = IA_MODE_NONE;
1278
1279 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1280 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1281
1282 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1283 }
1284
1285 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1286 hdr[1] = htons(cand->duid_len);
1287 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1288 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1289 accept_reconfig = cand->wants_reconfigure;
1290 if (cand->ia_na_len) {
1291 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1292 free(cand->ia_na);
1293 if (na_mode != IA_MODE_NONE)
1294 ret = DHCPV6_STATEFUL;
1295 }
1296 if (cand->ia_pd_len) {
1297 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1298 free(cand->ia_pd);
1299 if (request_prefix)
1300 ret = DHCPV6_STATEFUL;
1301 }
1302
1303 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1304 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1305
1306 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1307
1308 return ret;
1309 }
Openwrt DHCPv6 Client