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Support for SOL_MAX_RT and INF_MAX_RT options (RFC7083)
[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <arpa/inet.h>
30 #include <netinet/in.h>
31
32 #include <net/if.h>
33 #include <net/ethernet.h>
34
35 #include "odhcp6c.h"
36 #include "md5.h"
37
38
39 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
40 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
41 #define DHCPV6_CLIENT_PORT 546
42 #define DHCPV6_SERVER_PORT 547
43 #define DHCPV6_DUID_LLADDR 3
44 #define DHCPV6_REQ_DELAY 1
45
46 #define DHCPV6_SOL_MAX_RT_MIN 60
47 #define DHCPV6_SOL_MAX_RT_MAX 86400
48 #define DHCPV6_INF_MAX_RT_MIN 60
49 #define DHCPV6_INF_MAX_RT_MAX 86400
50
51 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
52 const uint8_t transaction[3], enum dhcpv6_msg type,
53 const struct in6_addr *daddr);
54
55 static int dhcpv6_parse_ia(void *opt, void *end);
56
57 static int dhcpv6_calc_refresh_timers(void);
58 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
59 const uint16_t code, const void *status_msg, const int len,
60 int *ret);
61 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
62 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
63 const void *status_msg, const int len,
64 bool handled_status_codes[_DHCPV6_Status_Max],
65 int *ret);
66 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
67 static void dhcpv6_clear_all_server_cand(void);
68
69 static reply_handler dhcpv6_handle_reply;
70 static reply_handler dhcpv6_handle_advert;
71 static reply_handler dhcpv6_handle_rebind_reply;
72 static reply_handler dhcpv6_handle_reconfigure;
73 static int dhcpv6_commit_advert(void);
74
75
76
77 // RFC 3315 - 5.5 Timeout and Delay values
78 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
79 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
80 dhcpv6_handle_reconfigure, NULL},
81 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
82 dhcpv6_handle_advert, dhcpv6_commit_advert},
83 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
84 dhcpv6_handle_reply, NULL},
85 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
86 dhcpv6_handle_reply, NULL},
87 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
88 dhcpv6_handle_rebind_reply, NULL},
89 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
90 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
91 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
92 dhcpv6_handle_reply, NULL},
93 };
94
95
96 // Sockets
97 static int sock = -1;
98 static int ifindex = -1;
99 static int64_t t1 = 0, t2 = 0, t3 = 0;
100
101 // IA states
102 static int request_prefix = -1;
103 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
104 static bool accept_reconfig = false;
105 // Server unicast address
106 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
107
108 // Reconfigure key
109 static uint8_t reconf_key[16];
110
111
112 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
113 {
114 request_prefix = request_pd;
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 uint16_t oro[] = {
165 htons(DHCPV6_OPT_SIP_SERVER_D),
166 htons(DHCPV6_OPT_SIP_SERVER_A),
167 htons(DHCPV6_OPT_DNS_SERVERS),
168 htons(DHCPV6_OPT_DNS_DOMAIN),
169 htons(DHCPV6_OPT_UNICAST),
170 htons(DHCPV6_OPT_NTP_SERVER),
171 htons(DHCPV6_OPT_AFTR_NAME),
172 htons(DHCPV6_OPT_PD_EXCLUDE),
173 htons(DHCPV6_OPT_SOL_MAX_RT),
174 htons(DHCPV6_OPT_INF_MAX_RT),
175 #ifdef EXT_PREFIX_CLASS
176 htons(DHCPV6_OPT_PREFIX_CLASS),
177 #endif
178 };
179 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
180
181 // Configure IPv6-options
182 int val = 1;
183 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
184 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
185 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
186 val = 0;
187 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
188 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
189
190 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
191 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
192 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
193 return -1;
194
195 return 0;
196 }
197
198
199 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
200 {
201 na_mode = na;
202 pd_mode = pd;
203 }
204
205
206 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
207 {
208 // Build FQDN
209 char fqdn_buf[256];
210 gethostname(fqdn_buf, sizeof(fqdn_buf));
211 struct {
212 uint16_t type;
213 uint16_t len;
214 uint8_t flags;
215 uint8_t data[256];
216 } fqdn;
217 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
218 sizeof(fqdn.data), NULL, NULL);
219 fqdn.type = htons(DHCPV6_OPT_FQDN);
220 fqdn.len = htons(fqdn_len - 4);
221 fqdn.flags = 0;
222
223
224 // Build Client ID
225 size_t cl_id_len;
226 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
227
228 // Get Server ID
229 size_t srv_id_len;
230 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
231
232 // Build IA_PDs
233 size_t ia_pd_entries, ia_pd_len = 0;
234 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
235 ia_pd_entries /= sizeof(*e);
236 struct dhcpv6_ia_hdr hdr_ia_pd = {
237 htons(DHCPV6_OPT_IA_PD),
238 htons(sizeof(hdr_ia_pd) - 4),
239 1, 0, 0
240 };
241
242
243 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
244 for (size_t i = 0; i < ia_pd_entries; ++i) {
245 uint8_t ex_len = 0;
246 if (e[i].priority > 0)
247 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
248
249 struct dhcpv6_ia_prefix p = {
250 .type = htons(DHCPV6_OPT_IA_PREFIX),
251 .len = htons(sizeof(p) - 4U + ex_len),
252 .prefix = e[i].length,
253 .addr = e[i].target
254 };
255
256 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
257 ia_pd_len += sizeof(p);
258
259 if (ex_len) {
260 ia_pd[ia_pd_len++] = 0;
261 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
262 ia_pd[ia_pd_len++] = 0;
263 ia_pd[ia_pd_len++] = ex_len - 4;
264 ia_pd[ia_pd_len++] = e[i].priority;
265
266 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
267 excl >>= (64 - e[i].priority);
268 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
269
270 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
271 ia_pd[ia_pd_len + i] = excl & 0xff;
272 ia_pd_len += ex_len - 5;
273 }
274 }
275
276 struct dhcpv6_ia_prefix pref = {
277 .type = htons(DHCPV6_OPT_IA_PREFIX),
278 .len = htons(25), .prefix = request_prefix
279 };
280 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
281 ia_pd = (uint8_t*)&pref;
282 ia_pd_len = sizeof(pref);
283 }
284 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
285
286 // Build IA_NAs
287 size_t ia_na_entries, ia_na_len = 0;
288 void *ia_na = NULL;
289 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
290 ia_na_entries /= sizeof(*e);
291
292 struct dhcpv6_ia_hdr hdr_ia_na = {
293 htons(DHCPV6_OPT_IA_NA),
294 htons(sizeof(hdr_ia_na) - 4),
295 1, 0, 0
296 };
297
298 struct dhcpv6_ia_addr pa[ia_na_entries];
299 for (size_t i = 0; i < ia_na_entries; ++i) {
300 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
301 pa[i].len = htons(sizeof(pa[i]) - 4U);
302 pa[i].addr = e[i].target;
303 pa[i].preferred = 0;
304 pa[i].valid = 0;
305 }
306
307 ia_na = pa;
308 ia_na_len = sizeof(pa);
309 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
310
311 // Reconfigure Accept
312 struct {
313 uint16_t type;
314 uint16_t length;
315 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
316
317 // Request Information Refresh
318 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
319
320 // Prepare Header
321 size_t oro_len;
322 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
323 struct {
324 uint8_t type;
325 uint8_t trid[3];
326 uint16_t elapsed_type;
327 uint16_t elapsed_len;
328 uint16_t elapsed_value;
329 uint16_t oro_type;
330 uint16_t oro_len;
331 } hdr = {
332 type, {trid[0], trid[1], trid[2]},
333 htons(DHCPV6_OPT_ELAPSED), htons(2),
334 htons((ecs > 0xffff) ? 0xffff : ecs),
335 htons(DHCPV6_OPT_ORO), htons(oro_len),
336 };
337
338 struct iovec iov[] = {
339 {&hdr, sizeof(hdr)},
340 {oro, oro_len},
341 {&oro_refresh, 0},
342 {cl_id, cl_id_len},
343 {srv_id, srv_id_len},
344 {&reconf_accept, sizeof(reconf_accept)},
345 {&fqdn, fqdn_len},
346 {&hdr_ia_na, sizeof(hdr_ia_na)},
347 {ia_na, ia_na_len},
348 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
349 {ia_pd, ia_pd_len},
350 };
351
352 size_t cnt = ARRAY_SIZE(iov);
353 if (type == DHCPV6_MSG_INFO_REQ) {
354 cnt = 5;
355 iov[2].iov_len = sizeof(oro_refresh);
356 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
357 } else if (!request_prefix) {
358 cnt = 9;
359 }
360
361 // Disable IAs if not used
362 if (type != DHCPV6_MSG_SOLICIT) {
363 iov[5].iov_len = 0;
364 if (ia_na_len == 0)
365 iov[7].iov_len = 0;
366 if (ia_pd_len == 0)
367 iov[9].iov_len = 0;
368 }
369
370 if (na_mode == IA_MODE_NONE)
371 iov[7].iov_len = 0;
372
373 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
374 0, ALL_DHCPV6_RELAYS, ifindex};
375 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
376
377 switch (type) {
378 case DHCPV6_MSG_REQUEST:
379 case DHCPV6_MSG_RENEW:
380 case DHCPV6_MSG_RELEASE:
381 case DHCPV6_MSG_DECLINE:
382 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
383 odhcp6c_addr_in_scope(&server_addr)) {
384 srv.sin6_addr = server_addr;
385 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
386 srv.sin6_scope_id = 0;
387 }
388 break;
389 default:
390 break;
391 }
392
393 if (sendmsg(sock, &msg, 0) < 0) {
394 char in6_str[INET6_ADDRSTRLEN];
395
396 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
397 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
398 in6_str, sizeof(in6_str)), strerror(errno));
399 }
400 }
401
402
403 static int64_t dhcpv6_rand_delay(int64_t time)
404 {
405 int random;
406 odhcp6c_random(&random, sizeof(random));
407 return (time * ((int64_t)random % 1000LL)) / 10000LL;
408 }
409
410
411 int dhcpv6_request(enum dhcpv6_msg type)
412 {
413 uint8_t rc = 0;
414 uint64_t timeout = UINT32_MAX;
415 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
416
417 if (retx->delay) {
418 struct timespec ts = {0, 0};
419 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
420 nanosleep(&ts, NULL);
421 }
422
423 if (type == DHCPV6_MSG_UNKNOWN)
424 timeout = t1;
425 else if (type == DHCPV6_MSG_RENEW)
426 timeout = (t2 > t1) ? t2 - t1 : 0;
427 else if (type == DHCPV6_MSG_REBIND)
428 timeout = (t3 > t2) ? t3 - t2 : 0;
429
430 if (timeout == 0)
431 return -1;
432
433 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
434 retx->name, (unsigned long long)timeout, retx->max_rc);
435
436 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
437
438 // Generate transaction ID
439 uint8_t trid[3] = {0, 0, 0};
440 if (type != DHCPV6_MSG_UNKNOWN)
441 odhcp6c_random(trid, sizeof(trid));
442 ssize_t len = -1;
443 int64_t rto = 0;
444
445 do {
446 if (rto == 0) {
447 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
448
449 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
450 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
451 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
452
453 rto = (retx->init_timeo * 1000 + delay);
454 }
455 else
456 rto = (2 * rto + dhcpv6_rand_delay(rto));
457
458 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
459 rto = retx->max_timeo * 1000 +
460 dhcpv6_rand_delay(retx->max_timeo * 1000);
461
462 // Calculate end for this round and elapsed time
463 uint64_t round_end = round_start + rto;
464 elapsed = round_start - start;
465
466 // Don't wait too long
467 if (round_end - start > timeout * 1000)
468 round_end = timeout * 1000 + start;
469
470 // Built and send package
471 if (type != DHCPV6_MSG_UNKNOWN) {
472 if (type != DHCPV6_MSG_SOLICIT)
473 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
474 retx->name, (unsigned long long)elapsed, rc);
475 dhcpv6_send(type, trid, elapsed / 10);
476 rc++;
477 }
478
479 // Receive rounds
480 for (; len < 0 && (round_start < round_end);
481 round_start = odhcp6c_get_milli_time()) {
482 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
483 struct iovec iov = {buf, sizeof(buf)};
484 struct msghdr msg = {NULL, 0, &iov, 1,
485 cmsg_buf, sizeof(cmsg_buf), 0};
486 struct in6_pktinfo *pktinfo = NULL;
487
488 // Check for pending signal
489 if (odhcp6c_signal_process())
490 return -1;
491
492 // Set timeout for receiving
493 uint64_t t = round_end - round_start;
494 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
495 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
496 &timeout, sizeof(timeout));
497
498 // Receive cycle
499 len = recvmsg(sock, &msg, 0);
500 if (len < 0)
501 continue;
502
503 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
504 ch = CMSG_NXTHDR(&msg, ch)) {
505 if (ch->cmsg_level == SOL_IPV6 &&
506 ch->cmsg_type == IPV6_PKTINFO) {
507 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
508 break;
509 }
510 }
511
512 if (pktinfo == NULL) {
513 len = -1;
514 continue;
515 }
516
517 if (!dhcpv6_response_is_valid(buf, len, trid,
518 type, &pktinfo->ipi6_addr)) {
519 len = -1;
520 continue;
521 }
522
523 uint8_t *opt = &buf[4];
524 uint8_t *opt_end = opt + len - 4;
525
526 round_start = odhcp6c_get_milli_time();
527 elapsed = round_start - start;
528 syslog(LOG_NOTICE, "Got a valid reply after "
529 "%llums", (unsigned long long)elapsed);
530
531 if (retx->handler_reply)
532 len = retx->handler_reply(type, rc, opt, opt_end);
533
534 if (len > 0 && round_end - round_start > 1000)
535 round_end = 1000 + round_start;
536 }
537
538 // Allow
539 if (retx->handler_finish)
540 len = retx->handler_finish();
541 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
542
543 return len;
544 }
545
546 // Message validation checks according to RFC3315 chapter 15
547 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
548 const uint8_t transaction[3], enum dhcpv6_msg type,
549 const struct in6_addr *daddr)
550 {
551 const struct dhcpv6_header *rep = buf;
552 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
553 transaction, sizeof(rep->tr_id)))
554 return false; // Invalid reply
555
556 if (type == DHCPV6_MSG_SOLICIT) {
557 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
558 rep->msg_type != DHCPV6_MSG_REPLY)
559 return false;
560 } else if (type == DHCPV6_MSG_UNKNOWN) {
561 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
562 return false;
563 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
564 return false;
565 }
566
567 uint8_t *end = ((uint8_t*)buf) + len, *odata,
568 rcmsg = DHCPV6_MSG_UNKNOWN;
569 uint16_t otype, olen;
570 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
571 ia_present = false, options_valid = true;
572
573 size_t client_id_len, server_id_len;
574 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
575 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
576
577 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
578 if (otype == DHCPV6_OPT_CLIENTID) {
579 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
580 &odata[-4], client_id, client_id_len);
581 } else if (otype == DHCPV6_OPT_SERVERID) {
582 if (server_id_len)
583 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
584 &odata[-4], server_id, server_id_len);
585 else
586 serverid_ok = true;
587 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
588 sizeof(struct dhcpv6_auth_reconfigure)) {
589 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
590 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
591 continue;
592
593 md5_state_t md5;
594 uint8_t serverhash[16], secretbytes[16], hash[16];
595 memcpy(serverhash, r->key, sizeof(serverhash));
596 memset(r->key, 0, sizeof(r->key));
597 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
598
599 for (size_t i = 0; i < sizeof(secretbytes); ++i)
600 secretbytes[i] ^= 0x36;
601
602 md5_init(&md5);
603 md5_append(&md5, secretbytes, sizeof(secretbytes));
604 md5_append(&md5, buf, len);
605 md5_finish(&md5, hash);
606
607 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
608 secretbytes[i] ^= 0x36;
609 secretbytes[i] ^= 0x5c;
610 }
611
612 md5_init(&md5);
613 md5_append(&md5, secretbytes, sizeof(secretbytes));
614 md5_append(&md5, hash, 16);
615 md5_finish(&md5, hash);
616
617 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
618 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
619 rcmsg = odata[0];
620 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
621 ia_present = true;
622 if (olen < sizeof(struct dhcpv6_ia_hdr))
623 options_valid = false;
624 }
625 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
626 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
627 // Options are not allowed on global level
628 options_valid = false;
629 }
630 }
631
632 if (!options_valid || ((odata + olen) > end))
633 return false;
634
635 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
636 return false;
637
638 if (rep->msg_type == DHCPV6_MSG_RECONF) {
639 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
640 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
641 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
642 return false;
643 }
644
645 return clientid_ok && serverid_ok;
646 }
647
648
649 int dhcpv6_poll_reconfigure(void)
650 {
651 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
652 if (ret != -1)
653 ret = dhcpv6_request(ret);
654
655 return ret;
656 }
657
658
659 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
660 const void *opt, const void *end)
661 {
662 uint16_t otype, olen;
663 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
664 dhcpv6_for_each_option(opt, end, otype, olen, odata)
665 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
666 odata[0] == DHCPV6_MSG_RENEW ||
667 odata[0] == DHCPV6_MSG_INFO_REQ))
668 msg = odata[0];
669
670 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
671 return msg;
672 }
673
674
675 // Collect all advertised servers
676 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
677 const void *opt, const void *end)
678 {
679 uint16_t olen, otype;
680 uint8_t *odata, pref = 0;
681 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
682 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
683 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
684 bool have_na = false;
685 int have_pd = 0;
686
687 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
688 if (orig == DHCPV6_MSG_SOLICIT &&
689 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
690 olen > sizeof(struct dhcpv6_ia_hdr)) {
691 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
692 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
693 }
694
695 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
696 memcpy(cand.duid, odata, olen);
697 cand.duid_len = olen;
698 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
699 int error = ((int)odata[0] << 8 | (int)odata[1]);
700
701 switch (error) {
702 case DHCPV6_NoPrefixAvail:
703 // Status code on global level
704 cand.preference -= 2000;
705 break;
706
707 default :
708 break;
709 }
710 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
711 cand.preference >= 0) {
712 cand.preference = pref = odata[0];
713 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
714 cand.server_addr = *(struct in6_addr *)odata;
715 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
716 cand.wants_reconfigure = true;
717 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
718 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
719 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
720 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
721 cand.sol_max_rt = sol_max_rt;
722 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
723 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
724 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
725 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
726 cand.inf_max_rt = inf_max_rt;
727 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
728 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
729 uint8_t *oend = odata + olen, *d;
730 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
731 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
732 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
733 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
734 have_pd = p->prefix;
735 }
736 }
737 } else if (otype == DHCPV6_OPT_IA_NA) {
738 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
739 uint8_t *oend = odata + olen, *d;
740 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
741 if (otype == DHCPV6_OPT_IA_ADDR)
742 have_na = true;
743 }
744 }
745
746 if ((!have_na && na_mode == IA_MODE_FORCE) ||
747 (!have_pd && pd_mode == IA_MODE_FORCE)) {
748 /*
749 * RFC7083 states to process the SOL_MAX_RT and
750 * INF_MAX_RT options even if the DHCPv6 server
751 * did not propose any IA_NA and/or IA_PD
752 */
753 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
754 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
755 return -1;
756 }
757
758 if (na_mode != IA_MODE_NONE && !have_na) {
759 cand.has_noaddravail = true;
760 cand.preference -= 1000;
761 }
762
763 if (pd_mode != IA_MODE_NONE) {
764 if (have_pd)
765 cand.preference += 2000 + (128 - have_pd);
766 else
767 cand.preference -= 2000;
768 }
769
770 if (cand.duid_len > 0) {
771 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
772 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
773 dhcpv6_add_server_cand(&cand);
774 }
775
776 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
777 }
778
779
780 static int dhcpv6_commit_advert(void)
781 {
782 return dhcpv6_promote_server_cand();
783 }
784
785
786 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
787 const void *opt, const void *end)
788 {
789 dhcpv6_handle_advert(orig, rc, opt, end);
790 if (dhcpv6_commit_advert() < 0)
791 return -1;
792
793 return dhcpv6_handle_reply(orig, rc, opt, end);
794 }
795
796
797 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
798 const void *opt, const void *end)
799 {
800 uint8_t *odata;
801 uint16_t otype, olen;
802 uint32_t refresh = UINT32_MAX;
803 int ret = 1;
804 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
805
806 odhcp6c_expire();
807
808 if (orig == DHCPV6_MSG_UNKNOWN) {
809 static time_t last_update = 0;
810 time_t now = odhcp6c_get_milli_time() / 1000;
811
812 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
813 last_update = now;
814
815 t1 -= elapsed;
816 t2 -= elapsed;
817 t3 -= elapsed;
818
819 if (t1 < 0)
820 t1 = 0;
821
822 if (t2 < 0)
823 t2 = 0;
824
825 if (t3 < 0)
826 t3 = 0;
827 }
828
829 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
830 // Delete NA and PD we have in the state from the Advert
831 odhcp6c_clear_state(STATE_IA_NA);
832 odhcp6c_clear_state(STATE_IA_PD);
833 }
834
835 if (opt) {
836 odhcp6c_clear_state(STATE_DNS);
837 odhcp6c_clear_state(STATE_SEARCH);
838 odhcp6c_clear_state(STATE_SNTP_IP);
839 odhcp6c_clear_state(STATE_SNTP_FQDN);
840 odhcp6c_clear_state(STATE_SIP_IP);
841 odhcp6c_clear_state(STATE_SIP_FQDN);
842 odhcp6c_clear_state(STATE_AFTR_NAME);
843 }
844
845 // Parse and find all matching IAs
846 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
847 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
848 && olen > sizeof(struct dhcpv6_ia_hdr)) {
849 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
850
851 // Test ID
852 if (ia_hdr->iaid != 1)
853 continue;
854
855 uint16_t code = DHCPV6_Success;
856 uint16_t stype, slen;
857 uint8_t *sdata;
858 // Get and handle status code
859 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
860 stype, slen, sdata) {
861 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
862 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
863 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
864
865 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
866
867 if (code == DHCPV6_Success)
868 continue;
869
870 dhcpv6_handle_ia_status_code(orig, ia_hdr,
871 code, mdata, mlen, handled_status_codes, &ret);
872
873
874 if (ret > 0)
875 return ret;
876 break;
877 }
878 }
879
880 if (code != DHCPV6_Success)
881 continue;
882
883 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
884 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
885 server_addr = *(struct in6_addr *)odata;
886 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
887 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
888 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
889 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
890
891 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
892 }
893 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
894 if (olen % 16 == 0)
895 odhcp6c_add_state(STATE_DNS, odata, olen);
896 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
897 odhcp6c_add_state(STATE_SEARCH, odata, olen);
898 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
899 uint16_t stype, slen;
900 uint8_t *sdata;
901 // Test status and bail if error
902 dhcpv6_for_each_option(odata, odata + olen,
903 stype, slen, sdata) {
904 if (slen == 16 && (stype == NTP_MC_ADDR ||
905 stype == NTP_SRV_ADDR))
906 odhcp6c_add_state(STATE_SNTP_IP,
907 sdata, slen);
908 else if (slen > 0 && stype == NTP_SRV_FQDN)
909 odhcp6c_add_state(STATE_SNTP_FQDN,
910 sdata, slen);
911 }
912 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
913 if (olen == 16)
914 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
915 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
916 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
917 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
918 refresh = ntohl(*((uint32_t*)odata));
919 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
920 sizeof(struct dhcpv6_auth_reconfigure)) {
921 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
922 if (r->protocol == 3 && r->algorithm == 1 &&
923 r->reconf_type == 1)
924 memcpy(reconf_key, r->key, sizeof(r->key));
925 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
926 size_t cur_len;
927 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
928 if (cur_len == 0)
929 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
930 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
931 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
932 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
933 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
934 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
935 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
936 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
937 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
938 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
939 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
940 }else if (otype != DHCPV6_OPT_CLIENTID &&
941 otype != DHCPV6_OPT_SERVERID) {
942 odhcp6c_add_state(STATE_CUSTOM_OPTS,
943 &odata[-4], olen + 4);
944 }
945 }
946
947 if (orig != DHCPV6_MSG_INFO_REQ) {
948 // Update refresh timers if no fatal status code was received
949 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
950 switch (orig) {
951 case DHCPV6_MSG_RENEW:
952 // Send further renews if T1 is not set
953 if (!t1)
954 ret = -1;
955 break;
956 case DHCPV6_MSG_REBIND:
957 // Send further rebinds if T1 and T2 is not set
958 if (!t1 && !t2)
959 ret = -1;
960 break;
961
962 case DHCPV6_MSG_REQUEST:
963 // All server candidates can be cleared if not yet bound
964 if (!odhcp6c_is_bound())
965 dhcpv6_clear_all_server_cand();
966
967 default :
968 break;
969 }
970 }
971 }
972 else if (ret > 0) {
973 // All server candidates can be cleared if not yet bound
974 if (!odhcp6c_is_bound())
975 dhcpv6_clear_all_server_cand();
976
977 t1 = refresh;
978 }
979
980 return ret;
981 }
982
983
984 static int dhcpv6_parse_ia(void *opt, void *end)
985 {
986 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
987 int parsed_ia = 0;
988 uint32_t t1, t2;
989 uint16_t otype, olen;
990 uint8_t *odata;
991
992 t1 = ntohl(ia_hdr->t1);
993 t2 = ntohl(ia_hdr->t2);
994
995 if (t1 > t2)
996 return 0;
997
998 // Update address IA
999 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1000 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1001 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1002
1003 if (otype == DHCPV6_OPT_IA_PREFIX) {
1004 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1005 if (olen + 4U < sizeof(*prefix))
1006 continue;
1007
1008 entry.valid = ntohl(prefix->valid);
1009 entry.preferred = ntohl(prefix->preferred);
1010
1011 if (entry.preferred > entry.valid)
1012 continue;
1013
1014 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1015 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1016 if (entry.t1 > entry.t2)
1017 entry.t1 = entry.t2;
1018
1019 entry.length = prefix->prefix;
1020 entry.target = prefix->addr;
1021 uint16_t stype, slen;
1022 uint8_t *sdata;
1023
1024 #ifdef EXT_PREFIX_CLASS
1025 // Find prefix class, if any
1026 dhcpv6_for_each_option(&prefix[1], odata + olen,
1027 stype, slen, sdata)
1028 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1029 entry.class = sdata[0] << 8 | sdata[1];
1030 #endif
1031
1032 // Parse PD-exclude
1033 bool ok = true;
1034 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1035 odata + olen, stype, slen, sdata) {
1036 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1037 continue;
1038
1039 uint8_t elen = sdata[0];
1040 if (elen > 64)
1041 elen = 64;
1042
1043 if (elen <= 32 || elen <= entry.length) {
1044 ok = false;
1045 continue;
1046 }
1047
1048
1049 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1050 if (slen <= bytes) {
1051 ok = false;
1052 continue;
1053 }
1054
1055 uint32_t exclude = 0;
1056 do {
1057 exclude = exclude << 8 | sdata[bytes];
1058 } while (--bytes);
1059
1060 exclude >>= 8 - ((elen - entry.length) % 8);
1061 exclude <<= 64 - elen;
1062
1063 // Abusing router & priority fields for exclusion
1064 entry.router = entry.target;
1065 entry.router.s6_addr32[1] |= htonl(exclude);
1066 entry.priority = elen;
1067 }
1068
1069 if (ok) {
1070 odhcp6c_update_entry(STATE_IA_PD, &entry);
1071 parsed_ia++;
1072 }
1073
1074 entry.priority = 0;
1075 memset(&entry.router, 0, sizeof(entry.router));
1076 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1077 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1078 if (olen + 4U < sizeof(*addr))
1079 continue;
1080
1081 entry.preferred = ntohl(addr->preferred);
1082 entry.valid = ntohl(addr->valid);
1083
1084 if (entry.preferred > entry.valid)
1085 continue;
1086
1087 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1088 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1089 if (entry.t1 > entry.t2)
1090 entry.t1 = entry.t2;
1091
1092 entry.length = 128;
1093 entry.target = addr->addr;
1094
1095 #ifdef EXT_PREFIX_CLASS
1096 uint16_t stype, slen;
1097 uint8_t *sdata;
1098 // Find prefix class, if any
1099 dhcpv6_for_each_option(&addr[1], odata + olen,
1100 stype, slen, sdata)
1101 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1102 entry.class = sdata[0] << 8 | sdata[1];
1103 #endif
1104
1105 odhcp6c_update_entry(STATE_IA_NA, &entry);
1106 parsed_ia++;
1107 }
1108 }
1109 return parsed_ia;
1110 }
1111
1112
1113 static int dhcpv6_calc_refresh_timers(void)
1114 {
1115 struct odhcp6c_entry *e;
1116 size_t ia_na_entries, ia_pd_entries, i;
1117 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1118
1119 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1120 ia_na_entries /= sizeof(*e);
1121 for (i = 0; i < ia_na_entries; i++) {
1122 if (e[i].t1 < l_t1)
1123 l_t1 = e[i].t1;
1124
1125 if (e[i].t2 < l_t2)
1126 l_t2 = e[i].t2;
1127
1128 if (e[i].valid > l_t3)
1129 l_t3 = e[i].valid;
1130 }
1131
1132 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1133 ia_pd_entries /= sizeof(*e);
1134 for (i = 0; i < ia_pd_entries; i++) {
1135 if (e[i].t1 < l_t1)
1136 l_t1 = e[i].t1;
1137
1138 if (e[i].t2 < l_t2)
1139 l_t2 = e[i].t2;
1140
1141 if (e[i].valid > l_t3)
1142 l_t3 = e[i].valid;
1143 }
1144
1145 if (ia_pd_entries || ia_na_entries) {
1146 t1 = l_t1;
1147 t2 = l_t2;
1148 t3 = l_t3;
1149 }
1150
1151 return (int)(ia_pd_entries + ia_na_entries);
1152 }
1153
1154
1155 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1156 const void *status_msg, const int len)
1157 {
1158 uint8_t buf[len + 3];
1159
1160 memset(buf, 0, sizeof(buf));
1161 if (len) {
1162 buf[0] = '(';
1163 memcpy(&buf[1], status_msg, len);
1164 buf[len + 1] = ')';
1165 }
1166
1167 syslog(LOG_WARNING, "Server returned %s status %i %s",
1168 scope, code, buf);
1169 }
1170
1171
1172 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1173 const uint16_t code, const void *status_msg, const int len,
1174 int *ret)
1175 {
1176 dhcpv6_log_status_code(code, "message", status_msg, len);
1177
1178 switch (code) {
1179 case DHCPV6_UnspecFail:
1180 // Generic failure
1181 *ret = 0;
1182 break;
1183
1184 case DHCPV6_UseMulticast:
1185 switch(orig) {
1186 case DHCPV6_MSG_REQUEST:
1187 case DHCPV6_MSG_RENEW:
1188 case DHCPV6_MSG_RELEASE:
1189 case DHCPV6_MSG_DECLINE:
1190 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1191 server_addr = in6addr_any;
1192 *ret = 0;
1193 break;
1194 default:
1195 break;
1196 }
1197 break;
1198
1199 case DHCPV6_NoAddrsAvail:
1200 case DHCPV6_NoPrefixAvail:
1201 if (orig == DHCPV6_MSG_REQUEST)
1202 *ret = 0; // Failure
1203 break;
1204
1205 default:
1206 break;
1207 }
1208 }
1209
1210
1211 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1212 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1213 const void *status_msg, const int len,
1214 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1215 {
1216 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1217 "IA_NA" : "IA_PD", status_msg, len);
1218
1219 switch (code) {
1220 case DHCPV6_NoBinding:
1221 switch (orig) {
1222 case DHCPV6_MSG_RENEW:
1223 case DHCPV6_MSG_REBIND:
1224 if ((*ret > 0) && !handled_status_codes[code])
1225 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1226 break;
1227
1228 default:
1229 break;
1230 }
1231 break;
1232
1233 case DHCPV6_NoAddrsAvail:
1234 case DHCPV6_NoPrefixAvail:
1235 switch (orig) {
1236 case DHCPV6_MSG_REQUEST:
1237 if (*ret != 0)
1238 *ret = 0;
1239 break;
1240 default:
1241 break;
1242 }
1243 break;
1244
1245 case DHCPV6_NotOnLink:
1246 // TODO handle not onlink in case of confirm
1247 break;
1248
1249 default:
1250 break;
1251 }
1252 }
1253
1254 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1255 {
1256 size_t cand_len, i;
1257 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1258
1259 // Remove identical duid server candidate
1260 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1261 if (cand->duid_len == c[i].duid_len &&
1262 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1263 free(c[i].ia_na);
1264 free(c[i].ia_pd);
1265 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1266 break;
1267 }
1268 }
1269
1270 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1271 i < cand_len / sizeof(*c); ++i) {
1272 if (c[i].preference < cand->preference)
1273 break;
1274 }
1275
1276 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1277 }
1278
1279 static void dhcpv6_clear_all_server_cand(void)
1280 {
1281 size_t cand_len, i;
1282 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1283
1284 // Server candidates need deep delete for IA_NA/IA_PD
1285 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1286 if (c[i].ia_na)
1287 free(c[i].ia_na);
1288 if (c[i].ia_pd)
1289 free(c[i].ia_pd);
1290 }
1291 odhcp6c_clear_state(STATE_SERVER_CAND);
1292 }
1293
1294 int dhcpv6_promote_server_cand(void)
1295 {
1296 size_t cand_len;
1297 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1298 uint16_t hdr[2];
1299 int ret = DHCPV6_STATELESS;
1300
1301 // Clear lingering candidate state info
1302 odhcp6c_clear_state(STATE_SERVER_ID);
1303 odhcp6c_clear_state(STATE_IA_NA);
1304 odhcp6c_clear_state(STATE_IA_PD);
1305
1306 if (!cand_len)
1307 return -1;
1308
1309 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1310 na_mode = IA_MODE_NONE;
1311
1312 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1313 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1314
1315 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1316 }
1317
1318 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1319 hdr[1] = htons(cand->duid_len);
1320 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1321 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1322 accept_reconfig = cand->wants_reconfigure;
1323 if (cand->ia_na_len) {
1324 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1325 free(cand->ia_na);
1326 if (na_mode != IA_MODE_NONE)
1327 ret = DHCPV6_STATEFUL;
1328 }
1329 if (cand->ia_pd_len) {
1330 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1331 free(cand->ia_pd);
1332 if (request_prefix)
1333 ret = DHCPV6_STATEFUL;
1334 }
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 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1340
1341 return ret;
1342 }
Openwrt DHCPv6 Client