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