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