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[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2014 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 // Build vendor-class option
372 size_t vendor_class_len, user_class_len;
373 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
374 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
375
376 struct {
377 uint16_t type;
378 uint16_t length;
379 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
380
381 struct {
382 uint16_t type;
383 uint16_t length;
384 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
385
386 // Prepare Header
387 size_t oro_len;
388 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
389 struct {
390 uint8_t type;
391 uint8_t trid[3];
392 uint16_t elapsed_type;
393 uint16_t elapsed_len;
394 uint16_t elapsed_value;
395 uint16_t oro_type;
396 uint16_t oro_len;
397 } hdr = {
398 type, {trid[0], trid[1], trid[2]},
399 htons(DHCPV6_OPT_ELAPSED), htons(2),
400 htons((ecs > 0xffff) ? 0xffff : ecs),
401 htons(DHCPV6_OPT_ORO), htons(oro_len),
402 };
403
404 struct iovec iov[] = {
405 {&hdr, sizeof(hdr)},
406 {oro, oro_len},
407 {&oro_refresh, 0},
408 {cl_id, cl_id_len},
409 {srv_id, srv_id_len},
410 {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
411 {vendor_class, vendor_class_len},
412 {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
413 {user_class, user_class_len},
414 {&reconf_accept, sizeof(reconf_accept)},
415 {&fqdn, fqdn_len},
416 {&hdr_ia_na, sizeof(hdr_ia_na)},
417 {ia_na, ia_na_len},
418 {ia_pd, ia_pd_len},
419 };
420
421 size_t cnt = ARRAY_SIZE(iov);
422 if (type == DHCPV6_MSG_INFO_REQ) {
423 cnt = 9;
424 iov[2].iov_len = sizeof(oro_refresh);
425 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
426 } else if (!request_prefix) {
427 cnt = 13;
428 }
429
430 // Disable IAs if not used
431 if (type != DHCPV6_MSG_SOLICIT) {
432 iov[7].iov_len = 0;
433 if (ia_na_len == 0)
434 iov[9].iov_len = 0;
435 }
436
437 if (na_mode == IA_MODE_NONE)
438 iov[9].iov_len = 0;
439
440 if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
441 iov[7].iov_len = 0;
442
443 if (!(client_options & DHCPV6_CLIENT_FQDN))
444 iov[8].iov_len = 0;
445
446 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
447 0, ALL_DHCPV6_RELAYS, ifindex};
448 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
449
450 sendmsg(sock, &msg, 0);
451 }
452
453
454 static int64_t dhcpv6_rand_delay(int64_t time)
455 {
456 int random;
457 odhcp6c_random(&random, sizeof(random));
458 return (time * ((int64_t)random % 1000LL)) / 10000LL;
459 }
460
461
462 int dhcpv6_request(enum dhcpv6_msg type)
463 {
464 uint8_t rc = 0;
465 uint64_t timeout = UINT32_MAX;
466 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
467
468 if (retx->delay) {
469 struct timespec ts = {0, 0};
470 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
471 nanosleep(&ts, NULL);
472 }
473
474 if (type == DHCPV6_MSG_UNKNOWN)
475 timeout = t1;
476 else if (type == DHCPV6_MSG_RENEW)
477 timeout = (t2 > t1) ? t2 - t1 : 0;
478 else if (type == DHCPV6_MSG_REBIND)
479 timeout = (t3 > t2) ? t3 - t2 : 0;
480
481 if (timeout == 0)
482 return -1;
483
484 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
485 retx->name, (unsigned long long)timeout, retx->max_rc);
486
487 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
488
489 // Generate transaction ID
490 uint8_t trid[3] = {0, 0, 0};
491 if (type != DHCPV6_MSG_UNKNOWN)
492 odhcp6c_random(trid, sizeof(trid));
493 ssize_t len = -1;
494 int64_t rto = 0;
495
496 do {
497 if (rto == 0) {
498 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
499
500 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
501 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
502 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
503
504 rto = (retx->init_timeo * 1000 + delay);
505 }
506 else
507 rto = (2 * rto + dhcpv6_rand_delay(rto));
508
509 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
510 rto = retx->max_timeo * 1000 +
511 dhcpv6_rand_delay(retx->max_timeo * 1000);
512
513 // Calculate end for this round and elapsed time
514 uint64_t round_end = round_start + rto;
515 elapsed = round_start - start;
516
517 // Don't wait too long
518 if (round_end - start > timeout * 1000)
519 round_end = timeout * 1000 + start;
520
521 // Built and send package
522 if (type != DHCPV6_MSG_UNKNOWN) {
523 if (type != DHCPV6_MSG_SOLICIT)
524 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
525 retx->name, (unsigned long long)elapsed, rc);
526 dhcpv6_send(type, trid, elapsed / 10);
527 rc++;
528 }
529
530 // Receive rounds
531 for (; len < 0 && (round_start < round_end);
532 round_start = odhcp6c_get_milli_time()) {
533 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
534 struct iovec iov = {buf, sizeof(buf)};
535 struct msghdr msg = {NULL, 0, &iov, 1,
536 cmsg_buf, sizeof(cmsg_buf), 0};
537 struct in6_pktinfo *pktinfo = NULL;
538
539 // Check for pending signal
540 if (odhcp6c_signal_process())
541 return -1;
542
543 // Set timeout for receiving
544 uint64_t t = round_end - round_start;
545 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
546 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
547 &timeout, sizeof(timeout));
548
549 // Receive cycle
550 len = recvmsg(sock, &msg, 0);
551 if (len < 0)
552 continue;
553
554 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
555 ch = CMSG_NXTHDR(&msg, ch)) {
556 if (ch->cmsg_level == SOL_IPV6 &&
557 ch->cmsg_type == IPV6_PKTINFO) {
558 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
559 break;
560 }
561 }
562
563 if (pktinfo == NULL) {
564 len = -1;
565 continue;
566 }
567
568 if (!dhcpv6_response_is_valid(buf, len, trid,
569 type, &pktinfo->ipi6_addr)) {
570 len = -1;
571 continue;
572 }
573
574 uint8_t *opt = &buf[4];
575 uint8_t *opt_end = opt + len - 4;
576
577 round_start = odhcp6c_get_milli_time();
578 elapsed = round_start - start;
579 syslog(LOG_NOTICE, "Got a valid reply after "
580 "%llums", (unsigned long long)elapsed);
581
582 if (retx->handler_reply)
583 len = retx->handler_reply(type, rc, opt, opt_end);
584
585 if (len > 0 && round_end - round_start > 1000)
586 round_end = 1000 + round_start;
587 }
588
589 // Allow
590 if (retx->handler_finish)
591 len = retx->handler_finish();
592 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
593
594 return len;
595 }
596
597 // Message validation checks according to RFC3315 chapter 15
598 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
599 const uint8_t transaction[3], enum dhcpv6_msg type,
600 const struct in6_addr *daddr)
601 {
602 const struct dhcpv6_header *rep = buf;
603 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
604 transaction, sizeof(rep->tr_id)))
605 return false; // Invalid reply
606
607 if (type == DHCPV6_MSG_SOLICIT) {
608 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
609 rep->msg_type != DHCPV6_MSG_REPLY)
610 return false;
611 } else if (type == DHCPV6_MSG_UNKNOWN) {
612 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
613 return false;
614 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
615 return false;
616 }
617
618 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
619 rcmsg = DHCPV6_MSG_UNKNOWN;
620 uint16_t otype, olen = UINT16_MAX;
621 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
622 ia_present = false, options_valid = true;
623
624 size_t client_id_len, server_id_len;
625 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
626 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
627
628 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
629 if (otype == DHCPV6_OPT_CLIENTID) {
630 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
631 &odata[-4], client_id, client_id_len);
632 } else if (otype == DHCPV6_OPT_SERVERID) {
633 if (server_id_len)
634 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
635 &odata[-4], server_id, server_id_len);
636 else
637 serverid_ok = true;
638 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
639 sizeof(struct dhcpv6_auth_reconfigure)) {
640 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
641 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
642 continue;
643
644 md5_ctx_t md5;
645 uint8_t serverhash[16], secretbytes[16], hash[16];
646 memcpy(serverhash, r->key, sizeof(serverhash));
647 memset(r->key, 0, sizeof(r->key));
648 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
649
650 for (size_t i = 0; i < sizeof(secretbytes); ++i)
651 secretbytes[i] ^= 0x36;
652
653 md5_begin(&md5);
654 md5_hash(secretbytes, sizeof(secretbytes), &md5);
655 md5_hash(buf, len, &md5);
656 md5_end(hash, &md5);
657
658 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
659 secretbytes[i] ^= 0x36;
660 secretbytes[i] ^= 0x5c;
661 }
662
663 md5_begin(&md5);
664 md5_hash(secretbytes, sizeof(secretbytes), &md5);
665 md5_hash(hash, 16, &md5);
666 md5_end(hash, &md5);
667
668 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
669 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
670 rcmsg = odata[0];
671 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
672 ia_present = true;
673 if (olen < sizeof(struct dhcpv6_ia_hdr))
674 options_valid = false;
675 }
676 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
677 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
678 // Options are not allowed on global level
679 options_valid = false;
680 }
681 }
682
683 if (!options_valid || ((odata + olen) > end))
684 return false;
685
686 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
687 return false;
688
689 if (rep->msg_type == DHCPV6_MSG_RECONF) {
690 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
691 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
692 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
693 return false;
694 }
695
696 return clientid_ok && serverid_ok;
697 }
698
699
700 int dhcpv6_poll_reconfigure(void)
701 {
702 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
703 if (ret != -1)
704 ret = dhcpv6_request(ret);
705
706 return ret;
707 }
708
709
710 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
711 const void *opt, const void *end)
712 {
713 uint16_t otype, olen;
714 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
715 dhcpv6_for_each_option(opt, end, otype, olen, odata)
716 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
717 odata[0] == DHCPV6_MSG_RENEW ||
718 odata[0] == DHCPV6_MSG_INFO_REQ))
719 msg = odata[0];
720
721 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
722 return msg;
723 }
724
725
726 // Collect all advertised servers
727 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
728 const void *opt, const void *end)
729 {
730 uint16_t olen, otype;
731 uint8_t *odata, pref = 0;
732 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
733 DHCPV6_SOL_MAX_RT,
734 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
735 bool have_na = false;
736 int have_pd = 0;
737
738 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
739 if (orig == DHCPV6_MSG_SOLICIT &&
740 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
741 olen > sizeof(struct dhcpv6_ia_hdr)) {
742 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
743 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
744 }
745
746 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
747 memcpy(cand.duid, odata, olen);
748 cand.duid_len = olen;
749 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
750 int error = ((int)odata[0] << 8 | (int)odata[1]);
751
752 switch (error) {
753 case DHCPV6_NoPrefixAvail:
754 // Status code on global level
755 cand.preference -= 2000;
756 break;
757
758 default :
759 break;
760 }
761 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
762 cand.preference >= 0) {
763 cand.preference = pref = odata[0];
764 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
765 cand.wants_reconfigure = true;
766 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
767 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
768 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
769 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
770 cand.sol_max_rt = sol_max_rt;
771 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
772 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
773 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
774 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
775 cand.inf_max_rt = inf_max_rt;
776 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
777 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
778 uint8_t *oend = odata + olen, *d;
779 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
780 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
781 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
782 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
783 have_pd = p->prefix;
784 }
785 }
786 } else if (otype == DHCPV6_OPT_IA_NA) {
787 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
788 uint8_t *oend = odata + olen, *d;
789 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
790 if (otype == DHCPV6_OPT_IA_ADDR)
791 have_na = true;
792 }
793 }
794
795 if ((!have_na && na_mode == IA_MODE_FORCE) ||
796 (!have_pd && pd_mode == IA_MODE_FORCE)) {
797 /*
798 * RFC7083 states to process the SOL_MAX_RT and
799 * INF_MAX_RT options even if the DHCPv6 server
800 * did not propose any IA_NA and/or IA_PD
801 */
802 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
803 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
804 return -1;
805 }
806
807 if (na_mode != IA_MODE_NONE && !have_na) {
808 cand.has_noaddravail = true;
809 cand.preference -= 1000;
810 }
811
812 if (pd_mode != IA_MODE_NONE) {
813 if (have_pd)
814 cand.preference += 2000 + (128 - have_pd);
815 else
816 cand.preference -= 2000;
817 }
818
819 if (cand.duid_len > 0) {
820 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
821 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
822 dhcpv6_add_server_cand(&cand);
823 }
824
825 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
826 }
827
828
829 static int dhcpv6_commit_advert(void)
830 {
831 return dhcpv6_promote_server_cand();
832 }
833
834
835 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
836 const void *opt, const void *end)
837 {
838 dhcpv6_handle_advert(orig, rc, opt, end);
839 if (dhcpv6_commit_advert() < 0)
840 return -1;
841
842 return dhcpv6_handle_reply(orig, rc, opt, end);
843 }
844
845
846 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
847 const void *opt, const void *end)
848 {
849 uint8_t *odata;
850 uint16_t otype, olen;
851 uint32_t refresh = UINT32_MAX;
852 int ret = 1;
853 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
854
855 odhcp6c_expire();
856
857 if (orig == DHCPV6_MSG_UNKNOWN) {
858 static time_t last_update = 0;
859 time_t now = odhcp6c_get_milli_time() / 1000;
860
861 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
862 last_update = now;
863
864 t1 -= elapsed;
865 t2 -= elapsed;
866 t3 -= elapsed;
867
868 if (t1 < 0)
869 t1 = 0;
870
871 if (t2 < 0)
872 t2 = 0;
873
874 if (t3 < 0)
875 t3 = 0;
876 }
877
878 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
879 // Delete NA and PD we have in the state from the Advert
880 odhcp6c_clear_state(STATE_IA_NA);
881 odhcp6c_clear_state(STATE_IA_PD);
882 }
883
884 if (opt) {
885 odhcp6c_clear_state(STATE_DNS);
886 odhcp6c_clear_state(STATE_SEARCH);
887 odhcp6c_clear_state(STATE_SNTP_IP);
888 odhcp6c_clear_state(STATE_NTP_IP);
889 odhcp6c_clear_state(STATE_NTP_FQDN);
890 odhcp6c_clear_state(STATE_SIP_IP);
891 odhcp6c_clear_state(STATE_SIP_FQDN);
892 odhcp6c_clear_state(STATE_AFTR_NAME);
893 }
894
895 // Parse and find all matching IAs
896 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
897 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
898 && olen > sizeof(struct dhcpv6_ia_hdr)) {
899 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
900
901 // Test ID
902 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
903 continue;
904
905 uint16_t code = DHCPV6_Success;
906 uint16_t stype, slen;
907 uint8_t *sdata;
908 // Get and handle status code
909 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
910 stype, slen, sdata) {
911 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
912 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
913 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
914
915 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
916
917 if (code == DHCPV6_Success)
918 continue;
919
920 dhcpv6_handle_ia_status_code(orig, ia_hdr,
921 code, mdata, mlen, handled_status_codes, &ret);
922
923
924 if (ret > 0)
925 return ret;
926 break;
927 }
928 }
929
930 if (code != DHCPV6_Success)
931 continue;
932
933 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
934 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
935 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
936 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
937 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
938
939 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
940 }
941 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
942 if (olen % 16 == 0)
943 odhcp6c_add_state(STATE_DNS, odata, olen);
944 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
945 odhcp6c_add_state(STATE_SEARCH, odata, olen);
946 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
947 if (olen % 16 == 0)
948 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
949 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
950 uint16_t stype, slen;
951 uint8_t *sdata;
952 // Test status and bail if error
953 dhcpv6_for_each_option(odata, odata + olen,
954 stype, slen, sdata) {
955 if (slen == 16 && (stype == NTP_MC_ADDR ||
956 stype == NTP_SRV_ADDR))
957 odhcp6c_add_state(STATE_NTP_IP,
958 sdata, slen);
959 else if (slen > 0 && stype == NTP_SRV_FQDN)
960 odhcp6c_add_state(STATE_NTP_FQDN,
961 sdata, slen);
962 }
963 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
964 if (olen == 16)
965 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
966 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
967 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
968 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
969 refresh = ntohl(*((uint32_t*)odata));
970 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
971 sizeof(struct dhcpv6_auth_reconfigure)) {
972 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
973 if (r->protocol == 3 && r->algorithm == 1 &&
974 r->reconf_type == 1)
975 memcpy(reconf_key, r->key, sizeof(r->key));
976 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
977 size_t cur_len;
978 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
979 if (cur_len == 0)
980 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
981 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
982 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
983 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
984 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
985 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
986 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
987 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
988 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
989 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
990 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
991 }else if (otype != DHCPV6_OPT_CLIENTID &&
992 otype != DHCPV6_OPT_SERVERID) {
993 odhcp6c_add_state(STATE_CUSTOM_OPTS,
994 &odata[-4], olen + 4);
995 }
996 }
997
998 if (orig != DHCPV6_MSG_INFO_REQ) {
999 // Update refresh timers if no fatal status code was received
1000 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1001 switch (orig) {
1002 case DHCPV6_MSG_RENEW:
1003 // Send further renews if T1 is not set
1004 if (!t1)
1005 ret = -1;
1006 break;
1007 case DHCPV6_MSG_REBIND:
1008 // Send further rebinds if T1 and T2 is not set
1009 if (!t1 && !t2)
1010 ret = -1;
1011 break;
1012
1013 case DHCPV6_MSG_REQUEST:
1014 // All server candidates can be cleared if not yet bound
1015 if (!odhcp6c_is_bound())
1016 dhcpv6_clear_all_server_cand();
1017
1018 default :
1019 break;
1020 }
1021 }
1022 }
1023 else if (ret > 0) {
1024 // All server candidates can be cleared if not yet bound
1025 if (!odhcp6c_is_bound())
1026 dhcpv6_clear_all_server_cand();
1027
1028 t1 = refresh;
1029 }
1030
1031 return ret;
1032 }
1033
1034
1035 static int dhcpv6_parse_ia(void *opt, void *end)
1036 {
1037 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1038 int parsed_ia = 0;
1039 uint32_t t1, t2;
1040 uint16_t otype, olen;
1041 uint8_t *odata;
1042
1043 t1 = ntohl(ia_hdr->t1);
1044 t2 = ntohl(ia_hdr->t2);
1045
1046 if (t1 > t2)
1047 return 0;
1048
1049 // Update address IA
1050 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1051 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1052 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1053
1054 entry.iaid = ia_hdr->iaid;
1055
1056 if (otype == DHCPV6_OPT_IA_PREFIX) {
1057 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1058 if (olen + 4U < sizeof(*prefix))
1059 continue;
1060
1061 entry.valid = ntohl(prefix->valid);
1062 entry.preferred = ntohl(prefix->preferred);
1063
1064 if (entry.preferred > entry.valid)
1065 continue;
1066
1067 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1068 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1069 if (entry.t1 > entry.t2)
1070 entry.t1 = entry.t2;
1071
1072 entry.length = prefix->prefix;
1073 entry.target = prefix->addr;
1074 uint16_t stype, slen;
1075 uint8_t *sdata;
1076
1077 #ifdef EXT_PREFIX_CLASS
1078 // Find prefix class, if any
1079 dhcpv6_for_each_option(&prefix[1], odata + olen,
1080 stype, slen, sdata)
1081 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1082 entry.class = sdata[0] << 8 | sdata[1];
1083 #endif
1084
1085 // Parse PD-exclude
1086 bool ok = true;
1087 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1088 odata + olen, stype, slen, sdata) {
1089 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1090 continue;
1091
1092 uint8_t elen = sdata[0];
1093 if (elen > 64)
1094 elen = 64;
1095
1096 if (elen <= 32 || elen <= entry.length) {
1097 ok = false;
1098 continue;
1099 }
1100
1101
1102 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1103 if (slen <= bytes) {
1104 ok = false;
1105 continue;
1106 }
1107
1108 uint32_t exclude = 0;
1109 do {
1110 exclude = exclude << 8 | sdata[bytes];
1111 } while (--bytes);
1112
1113 exclude >>= 8 - ((elen - entry.length) % 8);
1114 exclude <<= 64 - elen;
1115
1116 // Abusing router & priority fields for exclusion
1117 entry.router = entry.target;
1118 entry.router.s6_addr32[1] |= htonl(exclude);
1119 entry.priority = elen;
1120 }
1121
1122 if (ok) {
1123 odhcp6c_update_entry(STATE_IA_PD, &entry);
1124 parsed_ia++;
1125 }
1126
1127 entry.priority = 0;
1128 memset(&entry.router, 0, sizeof(entry.router));
1129 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1130 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1131 if (olen + 4U < sizeof(*addr))
1132 continue;
1133
1134 entry.preferred = ntohl(addr->preferred);
1135 entry.valid = ntohl(addr->valid);
1136
1137 if (entry.preferred > entry.valid)
1138 continue;
1139
1140 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1141 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1142 if (entry.t1 > entry.t2)
1143 entry.t1 = entry.t2;
1144
1145 entry.length = 128;
1146 entry.target = addr->addr;
1147
1148 #ifdef EXT_PREFIX_CLASS
1149 uint16_t stype, slen;
1150 uint8_t *sdata;
1151 // Find prefix class, if any
1152 dhcpv6_for_each_option(&addr[1], odata + olen,
1153 stype, slen, sdata)
1154 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1155 entry.class = sdata[0] << 8 | sdata[1];
1156 #endif
1157
1158 odhcp6c_update_entry(STATE_IA_NA, &entry);
1159 parsed_ia++;
1160 }
1161 }
1162 return parsed_ia;
1163 }
1164
1165
1166 static int dhcpv6_calc_refresh_timers(void)
1167 {
1168 struct odhcp6c_entry *e;
1169 size_t ia_na_entries, ia_pd_entries, i;
1170 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1171
1172 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1173 ia_na_entries /= sizeof(*e);
1174 for (i = 0; i < ia_na_entries; i++) {
1175 if (e[i].t1 < l_t1)
1176 l_t1 = e[i].t1;
1177
1178 if (e[i].t2 < l_t2)
1179 l_t2 = e[i].t2;
1180
1181 if (e[i].valid > l_t3)
1182 l_t3 = e[i].valid;
1183 }
1184
1185 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1186 ia_pd_entries /= sizeof(*e);
1187 for (i = 0; i < ia_pd_entries; i++) {
1188 if (e[i].t1 < l_t1)
1189 l_t1 = e[i].t1;
1190
1191 if (e[i].t2 < l_t2)
1192 l_t2 = e[i].t2;
1193
1194 if (e[i].valid > l_t3)
1195 l_t3 = e[i].valid;
1196 }
1197
1198 if (ia_pd_entries || ia_na_entries) {
1199 t1 = l_t1;
1200 t2 = l_t2;
1201 t3 = l_t3;
1202 } else {
1203 t1 = 600;
1204 }
1205
1206 return (int)(ia_pd_entries + ia_na_entries);
1207 }
1208
1209
1210 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1211 const void *status_msg, const int len)
1212 {
1213 uint8_t buf[len + 3];
1214
1215 memset(buf, 0, sizeof(buf));
1216 if (len) {
1217 buf[0] = '(';
1218 memcpy(&buf[1], status_msg, len);
1219 buf[len + 1] = ')';
1220 }
1221
1222 syslog(LOG_WARNING, "Server returned %s status %i %s",
1223 scope, code, buf);
1224 }
1225
1226
1227 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1228 const uint16_t code, const void *status_msg, const int len,
1229 int *ret)
1230 {
1231 dhcpv6_log_status_code(code, "message", status_msg, len);
1232
1233 switch (code) {
1234 case DHCPV6_UnspecFail:
1235 // Generic failure
1236 *ret = 0;
1237 break;
1238
1239 case DHCPV6_UseMulticast:
1240 // TODO handle multicast status code
1241 break;
1242
1243 case DHCPV6_NoAddrsAvail:
1244 case DHCPV6_NoPrefixAvail:
1245 if (orig == DHCPV6_MSG_REQUEST)
1246 *ret = 0; // Failure
1247 break;
1248
1249 default:
1250 break;
1251 }
1252 }
1253
1254
1255 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1256 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1257 const void *status_msg, const int len,
1258 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1259 {
1260 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1261 "IA_NA" : "IA_PD", status_msg, len);
1262
1263 switch (code) {
1264 case DHCPV6_NoBinding:
1265 switch (orig) {
1266 case DHCPV6_MSG_RENEW:
1267 case DHCPV6_MSG_REBIND:
1268 if ((*ret > 0) && !handled_status_codes[code])
1269 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1270 break;
1271
1272 default:
1273 break;
1274 }
1275 break;
1276
1277 case DHCPV6_NoAddrsAvail:
1278 case DHCPV6_NoPrefixAvail:
1279 switch (orig) {
1280 case DHCPV6_MSG_REQUEST:
1281 if (*ret != 0)
1282 *ret = 0;
1283 break;
1284 default:
1285 break;
1286 }
1287 break;
1288
1289 case DHCPV6_NotOnLink:
1290 // TODO handle not onlink in case of confirm
1291 break;
1292
1293 default:
1294 break;
1295 }
1296 }
1297
1298 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1299 {
1300 size_t cand_len, i;
1301 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1302
1303 // Remove identical duid server candidate
1304 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1305 if (cand->duid_len == c[i].duid_len &&
1306 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1307 free(c[i].ia_na);
1308 free(c[i].ia_pd);
1309 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1310 break;
1311 }
1312 }
1313
1314 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1315 i < cand_len / sizeof(*c); ++i) {
1316 if (c[i].preference < cand->preference)
1317 break;
1318 }
1319
1320 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1321 }
1322
1323 static void dhcpv6_clear_all_server_cand(void)
1324 {
1325 size_t cand_len, i;
1326 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1327
1328 // Server candidates need deep delete for IA_NA/IA_PD
1329 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1330 free(c[i].ia_na);
1331 free(c[i].ia_pd);
1332 }
1333 odhcp6c_clear_state(STATE_SERVER_CAND);
1334 }
1335
1336 int dhcpv6_promote_server_cand(void)
1337 {
1338 size_t cand_len;
1339 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1340 uint16_t hdr[2];
1341 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1342 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1343
1344 // Clear lingering candidate state info
1345 odhcp6c_clear_state(STATE_SERVER_ID);
1346 odhcp6c_clear_state(STATE_IA_NA);
1347 odhcp6c_clear_state(STATE_IA_PD);
1348
1349 if (!cand_len)
1350 return -1;
1351
1352 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1353 na_mode = IA_MODE_NONE;
1354
1355 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1356 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1357
1358 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1359 }
1360
1361 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1362 hdr[1] = htons(cand->duid_len);
1363 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1364 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1365 accept_reconfig = cand->wants_reconfigure;
1366 if (cand->ia_na_len) {
1367 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1368 free(cand->ia_na);
1369 if (na_mode != IA_MODE_NONE)
1370 ret = DHCPV6_STATEFUL;
1371 }
1372 if (cand->ia_pd_len) {
1373 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1374 free(cand->ia_pd);
1375 if (request_prefix)
1376 ret = DHCPV6_STATEFUL;
1377 }
1378
1379 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1380 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1381
1382 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1383
1384 return ret;
1385 }
Openwrt DHCPv6 Client