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allow disabling "client fqdn" and "accept reconfiguration" options
[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 // client options
109 static unsigned int client_options = 0;
110
111
112 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
113 {
114 client_options = options;
115 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
116
117 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
118 if (sock < 0)
119 return -1;
120
121 // Detect interface
122 struct ifreq ifr;
123 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
124 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
125 return -1;
126 ifindex = ifr.ifr_ifindex;
127
128 // Create client DUID
129 size_t client_id_len;
130 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
131 if (client_id_len == 0) {
132 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
133 DHCPV6_DUID_LLADDR, 0, 1};
134
135 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
136 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
137
138 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
139 struct ifreq ifs[100], *ifp, *ifend;
140 struct ifconf ifc;
141 ifc.ifc_req = ifs;
142 ifc.ifc_len = sizeof(ifs);
143
144 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
145 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
146 // If our interface doesn't have an address...
147 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
148 for (ifp = ifc.ifc_req; ifp < ifend &&
149 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
150 memcpy(ifr.ifr_name, ifp->ifr_name,
151 sizeof(ifr.ifr_name));
152 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
153 continue;
154
155 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
156 ETHER_ADDR_LEN);
157 }
158 }
159
160 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
161 }
162
163 // Create ORO
164 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
165 uint16_t oro[] = {
166 htons(DHCPV6_OPT_SIP_SERVER_D),
167 htons(DHCPV6_OPT_SIP_SERVER_A),
168 htons(DHCPV6_OPT_DNS_SERVERS),
169 htons(DHCPV6_OPT_DNS_DOMAIN),
170 htons(DHCPV6_OPT_SNTP_SERVERS),
171 htons(DHCPV6_OPT_NTP_SERVER),
172 htons(DHCPV6_OPT_AFTR_NAME),
173 htons(DHCPV6_OPT_PD_EXCLUDE),
174 htons(DHCPV6_OPT_SOL_MAX_RT),
175 htons(DHCPV6_OPT_INF_MAX_RT),
176 #ifdef EXT_PREFIX_CLASS
177 htons(DHCPV6_OPT_PREFIX_CLASS),
178 #endif
179 };
180 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
181 }
182
183 // Configure IPv6-options
184 int val = 1;
185 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
186 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
187 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
188 val = 0;
189 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
190 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
191
192 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
193 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
194 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
195 return -1;
196
197 return 0;
198 }
199
200
201 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
202 {
203 na_mode = na;
204 pd_mode = pd;
205 }
206
207 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
208 {
209 // Build FQDN
210 char fqdn_buf[256];
211 gethostname(fqdn_buf, sizeof(fqdn_buf));
212 struct {
213 uint16_t type;
214 uint16_t len;
215 uint8_t flags;
216 uint8_t data[256];
217 } fqdn;
218 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
219 sizeof(fqdn.data), NULL, NULL);
220 fqdn.type = htons(DHCPV6_OPT_FQDN);
221 fqdn.len = htons(fqdn_len - 4);
222 fqdn.flags = 0;
223
224
225 // Build Client ID
226 size_t cl_id_len;
227 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
228
229 // Get Server ID
230 size_t srv_id_len;
231 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
232
233 // Build IA_PDs
234 size_t ia_pd_entries, ia_pd_len = 0;
235 uint8_t *ia_pd;
236
237 if (type == DHCPV6_MSG_SOLICIT) {
238 odhcp6c_clear_state(STATE_IA_PD);
239 size_t n_prefixes;
240 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
241 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
242
243 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
244
245 for (size_t i = 0; i < n_prefixes; i++) {
246 struct dhcpv6_ia_hdr hdr_ia_pd = {
247 htons(DHCPV6_OPT_IA_PD),
248 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
249 request_prefixes[i].iaid, 0, 0
250 };
251 struct dhcpv6_ia_prefix pref = {
252 .type = htons(DHCPV6_OPT_IA_PREFIX),
253 .len = htons(25), .prefix = request_prefixes[i].length
254 };
255 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
256 ia_pd_len += sizeof(hdr_ia_pd);
257 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
258 ia_pd_len += sizeof(pref);
259 }
260 } else {
261 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
262 ia_pd_entries /= sizeof(*e);
263
264 // we're too lazy to count our distinct IAIDs,
265 // so just allocate maximally needed space
266 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
267 sizeof(struct dhcpv6_ia_hdr)));
268
269 for (size_t i = 0; i < ia_pd_entries; ++i) {
270 uint32_t iaid = e[i].iaid;
271
272 // check if this is an unprocessed IAID and skip if not.
273 int new_iaid = 1;
274 for (int j = i-1; j >= 0; j--) {
275 if (e[j].iaid == iaid) {
276 new_iaid = 0;
277 break;
278 }
279 }
280
281 if (!new_iaid)
282 continue;
283
284 // construct header
285 struct dhcpv6_ia_hdr hdr_ia_pd = {
286 htons(DHCPV6_OPT_IA_PD),
287 htons(sizeof(hdr_ia_pd) - 4),
288 iaid, 0, 0
289 };
290
291 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
292 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
293 ia_pd_len += sizeof(hdr_ia_pd);
294
295 for (size_t j = i; j < ia_pd_entries; j++) {
296 if (e[j].iaid != iaid)
297 continue;
298
299 uint8_t ex_len = 0;
300 if (e[j].priority > 0)
301 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
302
303 struct dhcpv6_ia_prefix p = {
304 .type = htons(DHCPV6_OPT_IA_PREFIX),
305 .len = htons(sizeof(p) - 4U + ex_len),
306 .prefix = e[j].length,
307 .addr = e[j].target
308 };
309
310 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
311 ia_pd_len += sizeof(p);
312
313 if (ex_len) {
314 ia_pd[ia_pd_len++] = 0;
315 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
316 ia_pd[ia_pd_len++] = 0;
317 ia_pd[ia_pd_len++] = ex_len - 4;
318 ia_pd[ia_pd_len++] = e[j].priority;
319
320 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
321 excl >>= (64 - e[j].priority);
322 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
323
324 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
325 ia_pd[ia_pd_len + i] = excl & 0xff;
326 ia_pd_len += ex_len - 5;
327 }
328
329 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
330 }
331 }
332 }
333
334 if (ia_pd_entries > 0)
335 request_prefix = 1;
336
337 // Build IA_NAs
338 size_t ia_na_entries, ia_na_len = 0;
339 void *ia_na = NULL;
340 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
341 ia_na_entries /= sizeof(*e);
342
343 struct dhcpv6_ia_hdr hdr_ia_na = {
344 htons(DHCPV6_OPT_IA_NA),
345 htons(sizeof(hdr_ia_na) - 4),
346 1, 0, 0
347 };
348
349 struct dhcpv6_ia_addr pa[ia_na_entries];
350 for (size_t i = 0; i < ia_na_entries; ++i) {
351 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
352 pa[i].len = htons(sizeof(pa[i]) - 4U);
353 pa[i].addr = e[i].target;
354 pa[i].preferred = 0;
355 pa[i].valid = 0;
356 }
357
358 ia_na = pa;
359 ia_na_len = sizeof(pa);
360 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
361
362 // Reconfigure Accept
363 struct {
364 uint16_t type;
365 uint16_t length;
366 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
367
368 // Request Information Refresh
369 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
370
371 // Prepare Header
372 size_t oro_len;
373 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
374 struct {
375 uint8_t type;
376 uint8_t trid[3];
377 uint16_t elapsed_type;
378 uint16_t elapsed_len;
379 uint16_t elapsed_value;
380 uint16_t oro_type;
381 uint16_t oro_len;
382 } hdr = {
383 type, {trid[0], trid[1], trid[2]},
384 htons(DHCPV6_OPT_ELAPSED), htons(2),
385 htons((ecs > 0xffff) ? 0xffff : ecs),
386 htons(DHCPV6_OPT_ORO), htons(oro_len),
387 };
388
389 struct iovec iov[] = {
390 {&hdr, sizeof(hdr)},
391 {oro, oro_len},
392 {&oro_refresh, 0},
393 {cl_id, cl_id_len},
394 {srv_id, srv_id_len},
395 {&reconf_accept, sizeof(reconf_accept)},
396 {&fqdn, fqdn_len},
397 {&hdr_ia_na, sizeof(hdr_ia_na)},
398 {ia_na, ia_na_len},
399 {ia_pd, ia_pd_len},
400 };
401
402 size_t cnt = ARRAY_SIZE(iov);
403 if (type == DHCPV6_MSG_INFO_REQ) {
404 cnt = 5;
405 iov[2].iov_len = sizeof(oro_refresh);
406 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
407 } else if (!request_prefix) {
408 cnt = 9;
409 }
410
411 // Disable IAs if not used
412 if (type != DHCPV6_MSG_SOLICIT) {
413 iov[5].iov_len = 0;
414 if (ia_na_len == 0)
415 iov[7].iov_len = 0;
416 }
417
418 if (na_mode == IA_MODE_NONE)
419 iov[7].iov_len = 0;
420
421 if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
422 iov[5].iov_len = 0;
423
424 if (!(client_options & DHCPV6_CLIENT_FQDN))
425 iov[6].iov_len = 0;
426
427 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
428 0, ALL_DHCPV6_RELAYS, ifindex};
429 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
430
431 sendmsg(sock, &msg, 0);
432 }
433
434
435 static int64_t dhcpv6_rand_delay(int64_t time)
436 {
437 int random;
438 odhcp6c_random(&random, sizeof(random));
439 return (time * ((int64_t)random % 1000LL)) / 10000LL;
440 }
441
442
443 int dhcpv6_request(enum dhcpv6_msg type)
444 {
445 uint8_t rc = 0;
446 uint64_t timeout = UINT32_MAX;
447 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
448
449 if (retx->delay) {
450 struct timespec ts = {0, 0};
451 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
452 nanosleep(&ts, NULL);
453 }
454
455 if (type == DHCPV6_MSG_UNKNOWN)
456 timeout = t1;
457 else if (type == DHCPV6_MSG_RENEW)
458 timeout = (t2 > t1) ? t2 - t1 : 0;
459 else if (type == DHCPV6_MSG_REBIND)
460 timeout = (t3 > t2) ? t3 - t2 : 0;
461
462 if (timeout == 0)
463 return -1;
464
465 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
466 retx->name, (unsigned long long)timeout, retx->max_rc);
467
468 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
469
470 // Generate transaction ID
471 uint8_t trid[3] = {0, 0, 0};
472 if (type != DHCPV6_MSG_UNKNOWN)
473 odhcp6c_random(trid, sizeof(trid));
474 ssize_t len = -1;
475 int64_t rto = 0;
476
477 do {
478 if (rto == 0) {
479 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
480
481 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
482 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
483 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
484
485 rto = (retx->init_timeo * 1000 + delay);
486 }
487 else
488 rto = (2 * rto + dhcpv6_rand_delay(rto));
489
490 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
491 rto = retx->max_timeo * 1000 +
492 dhcpv6_rand_delay(retx->max_timeo * 1000);
493
494 // Calculate end for this round and elapsed time
495 uint64_t round_end = round_start + rto;
496 elapsed = round_start - start;
497
498 // Don't wait too long
499 if (round_end - start > timeout * 1000)
500 round_end = timeout * 1000 + start;
501
502 // Built and send package
503 if (type != DHCPV6_MSG_UNKNOWN) {
504 if (type != DHCPV6_MSG_SOLICIT)
505 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
506 retx->name, (unsigned long long)elapsed, rc);
507 dhcpv6_send(type, trid, elapsed / 10);
508 rc++;
509 }
510
511 // Receive rounds
512 for (; len < 0 && (round_start < round_end);
513 round_start = odhcp6c_get_milli_time()) {
514 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
515 struct iovec iov = {buf, sizeof(buf)};
516 struct msghdr msg = {NULL, 0, &iov, 1,
517 cmsg_buf, sizeof(cmsg_buf), 0};
518 struct in6_pktinfo *pktinfo = NULL;
519
520 // Check for pending signal
521 if (odhcp6c_signal_process())
522 return -1;
523
524 // Set timeout for receiving
525 uint64_t t = round_end - round_start;
526 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
527 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
528 &timeout, sizeof(timeout));
529
530 // Receive cycle
531 len = recvmsg(sock, &msg, 0);
532 if (len < 0)
533 continue;
534
535 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
536 ch = CMSG_NXTHDR(&msg, ch)) {
537 if (ch->cmsg_level == SOL_IPV6 &&
538 ch->cmsg_type == IPV6_PKTINFO) {
539 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
540 break;
541 }
542 }
543
544 if (pktinfo == NULL) {
545 len = -1;
546 continue;
547 }
548
549 if (!dhcpv6_response_is_valid(buf, len, trid,
550 type, &pktinfo->ipi6_addr)) {
551 len = -1;
552 continue;
553 }
554
555 uint8_t *opt = &buf[4];
556 uint8_t *opt_end = opt + len - 4;
557
558 round_start = odhcp6c_get_milli_time();
559 elapsed = round_start - start;
560 syslog(LOG_NOTICE, "Got a valid reply after "
561 "%llums", (unsigned long long)elapsed);
562
563 if (retx->handler_reply)
564 len = retx->handler_reply(type, rc, opt, opt_end);
565
566 if (len > 0 && round_end - round_start > 1000)
567 round_end = 1000 + round_start;
568 }
569
570 // Allow
571 if (retx->handler_finish)
572 len = retx->handler_finish();
573 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
574
575 return len;
576 }
577
578 // Message validation checks according to RFC3315 chapter 15
579 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
580 const uint8_t transaction[3], enum dhcpv6_msg type,
581 const struct in6_addr *daddr)
582 {
583 const struct dhcpv6_header *rep = buf;
584 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
585 transaction, sizeof(rep->tr_id)))
586 return false; // Invalid reply
587
588 if (type == DHCPV6_MSG_SOLICIT) {
589 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
590 rep->msg_type != DHCPV6_MSG_REPLY)
591 return false;
592 } else if (type == DHCPV6_MSG_UNKNOWN) {
593 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
594 return false;
595 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
596 return false;
597 }
598
599 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
600 rcmsg = DHCPV6_MSG_UNKNOWN;
601 uint16_t otype, olen = UINT16_MAX;
602 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
603 ia_present = false, options_valid = true;
604
605 size_t client_id_len, server_id_len;
606 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
607 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
608
609 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
610 if (otype == DHCPV6_OPT_CLIENTID) {
611 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
612 &odata[-4], client_id, client_id_len);
613 } else if (otype == DHCPV6_OPT_SERVERID) {
614 if (server_id_len)
615 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
616 &odata[-4], server_id, server_id_len);
617 else
618 serverid_ok = true;
619 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
620 sizeof(struct dhcpv6_auth_reconfigure)) {
621 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
622 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
623 continue;
624
625 md5_ctx_t md5;
626 uint8_t serverhash[16], secretbytes[16], hash[16];
627 memcpy(serverhash, r->key, sizeof(serverhash));
628 memset(r->key, 0, sizeof(r->key));
629 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
630
631 for (size_t i = 0; i < sizeof(secretbytes); ++i)
632 secretbytes[i] ^= 0x36;
633
634 md5_begin(&md5);
635 md5_hash(secretbytes, sizeof(secretbytes), &md5);
636 md5_hash(buf, len, &md5);
637 md5_end(hash, &md5);
638
639 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
640 secretbytes[i] ^= 0x36;
641 secretbytes[i] ^= 0x5c;
642 }
643
644 md5_begin(&md5);
645 md5_hash(secretbytes, sizeof(secretbytes), &md5);
646 md5_hash(hash, 16, &md5);
647 md5_end(hash, &md5);
648
649 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
650 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
651 rcmsg = odata[0];
652 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
653 ia_present = true;
654 if (olen < sizeof(struct dhcpv6_ia_hdr))
655 options_valid = false;
656 }
657 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
658 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
659 // Options are not allowed on global level
660 options_valid = false;
661 }
662 }
663
664 if (!options_valid || ((odata + olen) > end))
665 return false;
666
667 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
668 return false;
669
670 if (rep->msg_type == DHCPV6_MSG_RECONF) {
671 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
672 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
673 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
674 return false;
675 }
676
677 return clientid_ok && serverid_ok;
678 }
679
680
681 int dhcpv6_poll_reconfigure(void)
682 {
683 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
684 if (ret != -1)
685 ret = dhcpv6_request(ret);
686
687 return ret;
688 }
689
690
691 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
692 const void *opt, const void *end)
693 {
694 uint16_t otype, olen;
695 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
696 dhcpv6_for_each_option(opt, end, otype, olen, odata)
697 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
698 odata[0] == DHCPV6_MSG_RENEW ||
699 odata[0] == DHCPV6_MSG_INFO_REQ))
700 msg = odata[0];
701
702 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
703 return msg;
704 }
705
706
707 // Collect all advertised servers
708 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
709 const void *opt, const void *end)
710 {
711 uint16_t olen, otype;
712 uint8_t *odata, pref = 0;
713 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
714 DHCPV6_SOL_MAX_RT,
715 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
716 bool have_na = false;
717 int have_pd = 0;
718
719 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
720 if (orig == DHCPV6_MSG_SOLICIT &&
721 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
722 olen > sizeof(struct dhcpv6_ia_hdr)) {
723 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
724 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
725 }
726
727 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
728 memcpy(cand.duid, odata, olen);
729 cand.duid_len = olen;
730 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
731 int error = ((int)odata[0] << 8 | (int)odata[1]);
732
733 switch (error) {
734 case DHCPV6_NoPrefixAvail:
735 // Status code on global level
736 cand.preference -= 2000;
737 break;
738
739 default :
740 break;
741 }
742 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
743 cand.preference >= 0) {
744 cand.preference = pref = odata[0];
745 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
746 cand.wants_reconfigure = true;
747 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
748 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
749 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
750 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
751 cand.sol_max_rt = sol_max_rt;
752 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
753 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
754 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
755 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
756 cand.inf_max_rt = inf_max_rt;
757 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
758 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
759 uint8_t *oend = odata + olen, *d;
760 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
761 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
762 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
763 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
764 have_pd = p->prefix;
765 }
766 }
767 } else if (otype == DHCPV6_OPT_IA_NA) {
768 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
769 uint8_t *oend = odata + olen, *d;
770 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
771 if (otype == DHCPV6_OPT_IA_ADDR)
772 have_na = true;
773 }
774 }
775
776 if ((!have_na && na_mode == IA_MODE_FORCE) ||
777 (!have_pd && pd_mode == IA_MODE_FORCE)) {
778 /*
779 * RFC7083 states to process the SOL_MAX_RT and
780 * INF_MAX_RT options even if the DHCPv6 server
781 * did not propose any IA_NA and/or IA_PD
782 */
783 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
784 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
785 return -1;
786 }
787
788 if (na_mode != IA_MODE_NONE && !have_na) {
789 cand.has_noaddravail = true;
790 cand.preference -= 1000;
791 }
792
793 if (pd_mode != IA_MODE_NONE) {
794 if (have_pd)
795 cand.preference += 2000 + (128 - have_pd);
796 else
797 cand.preference -= 2000;
798 }
799
800 if (cand.duid_len > 0) {
801 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
802 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
803 dhcpv6_add_server_cand(&cand);
804 }
805
806 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
807 }
808
809
810 static int dhcpv6_commit_advert(void)
811 {
812 return dhcpv6_promote_server_cand();
813 }
814
815
816 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
817 const void *opt, const void *end)
818 {
819 dhcpv6_handle_advert(orig, rc, opt, end);
820 if (dhcpv6_commit_advert() < 0)
821 return -1;
822
823 return dhcpv6_handle_reply(orig, rc, opt, end);
824 }
825
826
827 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
828 const void *opt, const void *end)
829 {
830 uint8_t *odata;
831 uint16_t otype, olen;
832 uint32_t refresh = UINT32_MAX;
833 int ret = 1;
834 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
835
836 odhcp6c_expire();
837
838 if (orig == DHCPV6_MSG_UNKNOWN) {
839 static time_t last_update = 0;
840 time_t now = odhcp6c_get_milli_time() / 1000;
841
842 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
843 last_update = now;
844
845 t1 -= elapsed;
846 t2 -= elapsed;
847 t3 -= elapsed;
848
849 if (t1 < 0)
850 t1 = 0;
851
852 if (t2 < 0)
853 t2 = 0;
854
855 if (t3 < 0)
856 t3 = 0;
857 }
858
859 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
860 // Delete NA and PD we have in the state from the Advert
861 odhcp6c_clear_state(STATE_IA_NA);
862 odhcp6c_clear_state(STATE_IA_PD);
863 }
864
865 if (opt) {
866 odhcp6c_clear_state(STATE_DNS);
867 odhcp6c_clear_state(STATE_SEARCH);
868 odhcp6c_clear_state(STATE_SNTP_IP);
869 odhcp6c_clear_state(STATE_NTP_IP);
870 odhcp6c_clear_state(STATE_NTP_FQDN);
871 odhcp6c_clear_state(STATE_SIP_IP);
872 odhcp6c_clear_state(STATE_SIP_FQDN);
873 odhcp6c_clear_state(STATE_AFTR_NAME);
874 }
875
876 // Parse and find all matching IAs
877 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
878 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
879 && olen > sizeof(struct dhcpv6_ia_hdr)) {
880 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
881
882 // Test ID
883 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
884 continue;
885
886 uint16_t code = DHCPV6_Success;
887 uint16_t stype, slen;
888 uint8_t *sdata;
889 // Get and handle status code
890 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
891 stype, slen, sdata) {
892 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
893 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
894 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
895
896 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
897
898 if (code == DHCPV6_Success)
899 continue;
900
901 dhcpv6_handle_ia_status_code(orig, ia_hdr,
902 code, mdata, mlen, handled_status_codes, &ret);
903
904
905 if (ret > 0)
906 return ret;
907 break;
908 }
909 }
910
911 if (code != DHCPV6_Success)
912 continue;
913
914 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
915 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
916 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
917 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
918 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
919
920 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
921 }
922 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
923 if (olen % 16 == 0)
924 odhcp6c_add_state(STATE_DNS, odata, olen);
925 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
926 odhcp6c_add_state(STATE_SEARCH, odata, olen);
927 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
928 if (olen % 16 == 0)
929 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
930 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
931 uint16_t stype, slen;
932 uint8_t *sdata;
933 // Test status and bail if error
934 dhcpv6_for_each_option(odata, odata + olen,
935 stype, slen, sdata) {
936 if (slen == 16 && (stype == NTP_MC_ADDR ||
937 stype == NTP_SRV_ADDR))
938 odhcp6c_add_state(STATE_NTP_IP,
939 sdata, slen);
940 else if (slen > 0 && stype == NTP_SRV_FQDN)
941 odhcp6c_add_state(STATE_NTP_FQDN,
942 sdata, slen);
943 }
944 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
945 if (olen == 16)
946 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
947 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
948 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
949 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
950 refresh = ntohl(*((uint32_t*)odata));
951 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
952 sizeof(struct dhcpv6_auth_reconfigure)) {
953 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
954 if (r->protocol == 3 && r->algorithm == 1 &&
955 r->reconf_type == 1)
956 memcpy(reconf_key, r->key, sizeof(r->key));
957 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
958 size_t cur_len;
959 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
960 if (cur_len == 0)
961 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
962 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
963 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
964 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
965 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
966 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
967 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
968 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
969 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
970 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
971 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
972 }else if (otype != DHCPV6_OPT_CLIENTID &&
973 otype != DHCPV6_OPT_SERVERID) {
974 odhcp6c_add_state(STATE_CUSTOM_OPTS,
975 &odata[-4], olen + 4);
976 }
977 }
978
979 if (orig != DHCPV6_MSG_INFO_REQ) {
980 // Update refresh timers if no fatal status code was received
981 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
982 switch (orig) {
983 case DHCPV6_MSG_RENEW:
984 // Send further renews if T1 is not set
985 if (!t1)
986 ret = -1;
987 break;
988 case DHCPV6_MSG_REBIND:
989 // Send further rebinds if T1 and T2 is not set
990 if (!t1 && !t2)
991 ret = -1;
992 break;
993
994 case DHCPV6_MSG_REQUEST:
995 // All server candidates can be cleared if not yet bound
996 if (!odhcp6c_is_bound())
997 dhcpv6_clear_all_server_cand();
998
999 default :
1000 break;
1001 }
1002 }
1003 }
1004 else if (ret > 0) {
1005 // All server candidates can be cleared if not yet bound
1006 if (!odhcp6c_is_bound())
1007 dhcpv6_clear_all_server_cand();
1008
1009 t1 = refresh;
1010 }
1011
1012 return ret;
1013 }
1014
1015
1016 static int dhcpv6_parse_ia(void *opt, void *end)
1017 {
1018 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1019 int parsed_ia = 0;
1020 uint32_t t1, t2;
1021 uint16_t otype, olen;
1022 uint8_t *odata;
1023
1024 t1 = ntohl(ia_hdr->t1);
1025 t2 = ntohl(ia_hdr->t2);
1026
1027 if (t1 > t2)
1028 return 0;
1029
1030 // Update address IA
1031 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1032 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1033 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1034
1035 entry.iaid = ia_hdr->iaid;
1036
1037 if (otype == DHCPV6_OPT_IA_PREFIX) {
1038 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1039 if (olen + 4U < sizeof(*prefix))
1040 continue;
1041
1042 entry.valid = ntohl(prefix->valid);
1043 entry.preferred = ntohl(prefix->preferred);
1044
1045 if (entry.preferred > entry.valid)
1046 continue;
1047
1048 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1049 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1050 if (entry.t1 > entry.t2)
1051 entry.t1 = entry.t2;
1052
1053 entry.length = prefix->prefix;
1054 entry.target = prefix->addr;
1055 uint16_t stype, slen;
1056 uint8_t *sdata;
1057
1058 #ifdef EXT_PREFIX_CLASS
1059 // Find prefix class, if any
1060 dhcpv6_for_each_option(&prefix[1], odata + olen,
1061 stype, slen, sdata)
1062 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1063 entry.class = sdata[0] << 8 | sdata[1];
1064 #endif
1065
1066 // Parse PD-exclude
1067 bool ok = true;
1068 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1069 odata + olen, stype, slen, sdata) {
1070 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1071 continue;
1072
1073 uint8_t elen = sdata[0];
1074 if (elen > 64)
1075 elen = 64;
1076
1077 if (elen <= 32 || elen <= entry.length) {
1078 ok = false;
1079 continue;
1080 }
1081
1082
1083 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1084 if (slen <= bytes) {
1085 ok = false;
1086 continue;
1087 }
1088
1089 uint32_t exclude = 0;
1090 do {
1091 exclude = exclude << 8 | sdata[bytes];
1092 } while (--bytes);
1093
1094 exclude >>= 8 - ((elen - entry.length) % 8);
1095 exclude <<= 64 - elen;
1096
1097 // Abusing router & priority fields for exclusion
1098 entry.router = entry.target;
1099 entry.router.s6_addr32[1] |= htonl(exclude);
1100 entry.priority = elen;
1101 }
1102
1103 if (ok) {
1104 odhcp6c_update_entry(STATE_IA_PD, &entry);
1105 parsed_ia++;
1106 }
1107
1108 entry.priority = 0;
1109 memset(&entry.router, 0, sizeof(entry.router));
1110 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1111 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1112 if (olen + 4U < sizeof(*addr))
1113 continue;
1114
1115 entry.preferred = ntohl(addr->preferred);
1116 entry.valid = ntohl(addr->valid);
1117
1118 if (entry.preferred > entry.valid)
1119 continue;
1120
1121 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1122 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1123 if (entry.t1 > entry.t2)
1124 entry.t1 = entry.t2;
1125
1126 entry.length = 128;
1127 entry.target = addr->addr;
1128
1129 #ifdef EXT_PREFIX_CLASS
1130 uint16_t stype, slen;
1131 uint8_t *sdata;
1132 // Find prefix class, if any
1133 dhcpv6_for_each_option(&addr[1], odata + olen,
1134 stype, slen, sdata)
1135 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1136 entry.class = sdata[0] << 8 | sdata[1];
1137 #endif
1138
1139 odhcp6c_update_entry(STATE_IA_NA, &entry);
1140 parsed_ia++;
1141 }
1142 }
1143 return parsed_ia;
1144 }
1145
1146
1147 static int dhcpv6_calc_refresh_timers(void)
1148 {
1149 struct odhcp6c_entry *e;
1150 size_t ia_na_entries, ia_pd_entries, i;
1151 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1152
1153 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1154 ia_na_entries /= sizeof(*e);
1155 for (i = 0; i < ia_na_entries; i++) {
1156 if (e[i].t1 < l_t1)
1157 l_t1 = e[i].t1;
1158
1159 if (e[i].t2 < l_t2)
1160 l_t2 = e[i].t2;
1161
1162 if (e[i].valid > l_t3)
1163 l_t3 = e[i].valid;
1164 }
1165
1166 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1167 ia_pd_entries /= sizeof(*e);
1168 for (i = 0; i < ia_pd_entries; i++) {
1169 if (e[i].t1 < l_t1)
1170 l_t1 = e[i].t1;
1171
1172 if (e[i].t2 < l_t2)
1173 l_t2 = e[i].t2;
1174
1175 if (e[i].valid > l_t3)
1176 l_t3 = e[i].valid;
1177 }
1178
1179 if (ia_pd_entries || ia_na_entries) {
1180 t1 = l_t1;
1181 t2 = l_t2;
1182 t3 = l_t3;
1183 } else {
1184 t1 = 600;
1185 }
1186
1187 return (int)(ia_pd_entries + ia_na_entries);
1188 }
1189
1190
1191 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1192 const void *status_msg, const int len)
1193 {
1194 uint8_t buf[len + 3];
1195
1196 memset(buf, 0, sizeof(buf));
1197 if (len) {
1198 buf[0] = '(';
1199 memcpy(&buf[1], status_msg, len);
1200 buf[len + 1] = ')';
1201 }
1202
1203 syslog(LOG_WARNING, "Server returned %s status %i %s",
1204 scope, code, buf);
1205 }
1206
1207
1208 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1209 const uint16_t code, const void *status_msg, const int len,
1210 int *ret)
1211 {
1212 dhcpv6_log_status_code(code, "message", status_msg, len);
1213
1214 switch (code) {
1215 case DHCPV6_UnspecFail:
1216 // Generic failure
1217 *ret = 0;
1218 break;
1219
1220 case DHCPV6_UseMulticast:
1221 // TODO handle multicast status code
1222 break;
1223
1224 case DHCPV6_NoAddrsAvail:
1225 case DHCPV6_NoPrefixAvail:
1226 if (orig == DHCPV6_MSG_REQUEST)
1227 *ret = 0; // Failure
1228 break;
1229
1230 default:
1231 break;
1232 }
1233 }
1234
1235
1236 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1237 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1238 const void *status_msg, const int len,
1239 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1240 {
1241 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1242 "IA_NA" : "IA_PD", status_msg, len);
1243
1244 switch (code) {
1245 case DHCPV6_NoBinding:
1246 switch (orig) {
1247 case DHCPV6_MSG_RENEW:
1248 case DHCPV6_MSG_REBIND:
1249 if ((*ret > 0) && !handled_status_codes[code])
1250 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1251 break;
1252
1253 default:
1254 break;
1255 }
1256 break;
1257
1258 case DHCPV6_NoAddrsAvail:
1259 case DHCPV6_NoPrefixAvail:
1260 switch (orig) {
1261 case DHCPV6_MSG_REQUEST:
1262 if (*ret != 0)
1263 *ret = 0;
1264 break;
1265 default:
1266 break;
1267 }
1268 break;
1269
1270 case DHCPV6_NotOnLink:
1271 // TODO handle not onlink in case of confirm
1272 break;
1273
1274 default:
1275 break;
1276 }
1277 }
1278
1279 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1280 {
1281 size_t cand_len, i;
1282 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1283
1284 // Remove identical duid server candidate
1285 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1286 if (cand->duid_len == c[i].duid_len &&
1287 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1288 free(c[i].ia_na);
1289 free(c[i].ia_pd);
1290 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1291 break;
1292 }
1293 }
1294
1295 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1296 i < cand_len / sizeof(*c); ++i) {
1297 if (c[i].preference < cand->preference)
1298 break;
1299 }
1300
1301 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1302 }
1303
1304 static void dhcpv6_clear_all_server_cand(void)
1305 {
1306 size_t cand_len, i;
1307 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1308
1309 // Server candidates need deep delete for IA_NA/IA_PD
1310 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1311 free(c[i].ia_na);
1312 free(c[i].ia_pd);
1313 }
1314 odhcp6c_clear_state(STATE_SERVER_CAND);
1315 }
1316
1317 int dhcpv6_promote_server_cand(void)
1318 {
1319 size_t cand_len;
1320 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1321 uint16_t hdr[2];
1322 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1323 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1324
1325 // Clear lingering candidate state info
1326 odhcp6c_clear_state(STATE_SERVER_ID);
1327 odhcp6c_clear_state(STATE_IA_NA);
1328 odhcp6c_clear_state(STATE_IA_PD);
1329
1330 if (!cand_len)
1331 return -1;
1332
1333 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1334 na_mode = IA_MODE_NONE;
1335
1336 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1337 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1338
1339 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1340 }
1341
1342 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1343 hdr[1] = htons(cand->duid_len);
1344 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1345 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1346 accept_reconfig = cand->wants_reconfigure;
1347 if (cand->ia_na_len) {
1348 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1349 free(cand->ia_na);
1350 if (na_mode != IA_MODE_NONE)
1351 ret = DHCPV6_STATEFUL;
1352 }
1353 if (cand->ia_pd_len) {
1354 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1355 free(cand->ia_pd);
1356 if (request_prefix)
1357 ret = DHCPV6_STATEFUL;
1358 }
1359
1360 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1361 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1362
1363 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1364
1365 return ret;
1366 }
Openwrt DHCPv6 Client