projects / project / odhcp6c.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
add support Vendor Class option
[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30
31 #include <net/if.h>
32 #include <net/ethernet.h>
33
34 #include "odhcp6c.h"
35 #include "md5.h"
36
37
38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
39 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
40 #define DHCPV6_CLIENT_PORT 546
41 #define DHCPV6_SERVER_PORT 547
42 #define DHCPV6_DUID_LLADDR 3
43 #define DHCPV6_REQ_DELAY 1
44
45 #define DHCPV6_SOL_MAX_RT_MIN 60
46 #define DHCPV6_SOL_MAX_RT_MAX 86400
47 #define DHCPV6_INF_MAX_RT_MIN 60
48 #define DHCPV6_INF_MAX_RT_MAX 86400
49
50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
51 const uint8_t transaction[3], enum dhcpv6_msg type,
52 const struct in6_addr *daddr);
53
54 static int dhcpv6_parse_ia(void *opt, void *end);
55
56 static int dhcpv6_calc_refresh_timers(void);
57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
58 const uint16_t code, const void *status_msg, const int len,
59 int *ret);
60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
61 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
62 const void *status_msg, const int len,
63 bool handled_status_codes[_DHCPV6_Status_Max],
64 int *ret);
65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
66 static void dhcpv6_clear_all_server_cand(void);
67
68 static reply_handler dhcpv6_handle_reply;
69 static reply_handler dhcpv6_handle_advert;
70 static reply_handler dhcpv6_handle_rebind_reply;
71 static reply_handler dhcpv6_handle_reconfigure;
72 static int dhcpv6_commit_advert(void);
73
74
75
76 // RFC 3315 - 5.5 Timeout and Delay values
77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
78 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
79 dhcpv6_handle_reconfigure, NULL},
80 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
81 dhcpv6_handle_advert, dhcpv6_commit_advert},
82 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
83 dhcpv6_handle_reply, NULL},
84 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
85 dhcpv6_handle_reply, NULL},
86 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
87 dhcpv6_handle_rebind_reply, NULL},
88 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
89 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
90 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
91 dhcpv6_handle_reply, NULL},
92 };
93
94
95 // Sockets
96 static int sock = -1;
97 static int ifindex = -1;
98 static int64_t t1 = 0, t2 = 0, t3 = 0;
99
100 // IA states
101 static int request_prefix = -1;
102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
103 static bool accept_reconfig = false;
104
105 // Reconfigure key
106 static uint8_t reconf_key[16];
107
108 // client options
109 static unsigned int client_options = 0;
110
111
112 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
113 {
114 client_options = options;
115 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
116
117 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
118 if (sock < 0)
119 return -1;
120
121 // Detect interface
122 struct ifreq ifr;
123 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
124 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
125 return -1;
126 ifindex = ifr.ifr_ifindex;
127
128 // Create client DUID
129 size_t client_id_len;
130 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
131 if (client_id_len == 0) {
132 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
133 DHCPV6_DUID_LLADDR, 0, 1};
134
135 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
136 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
137
138 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
139 struct ifreq ifs[100], *ifp, *ifend;
140 struct ifconf ifc;
141 ifc.ifc_req = ifs;
142 ifc.ifc_len = sizeof(ifs);
143
144 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
145 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
146 // If our interface doesn't have an address...
147 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
148 for (ifp = ifc.ifc_req; ifp < ifend &&
149 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
150 memcpy(ifr.ifr_name, ifp->ifr_name,
151 sizeof(ifr.ifr_name));
152 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
153 continue;
154
155 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
156 ETHER_ADDR_LEN);
157 }
158 }
159
160 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
161 }
162
163 // Create ORO
164 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
165 uint16_t oro[] = {
166 htons(DHCPV6_OPT_SIP_SERVER_D),
167 htons(DHCPV6_OPT_SIP_SERVER_A),
168 htons(DHCPV6_OPT_DNS_SERVERS),
169 htons(DHCPV6_OPT_DNS_DOMAIN),
170 htons(DHCPV6_OPT_SNTP_SERVERS),
171 htons(DHCPV6_OPT_NTP_SERVER),
172 htons(DHCPV6_OPT_AFTR_NAME),
173 htons(DHCPV6_OPT_PD_EXCLUDE),
174 htons(DHCPV6_OPT_SOL_MAX_RT),
175 htons(DHCPV6_OPT_INF_MAX_RT),
176 #ifdef EXT_PREFIX_CLASS
177 htons(DHCPV6_OPT_PREFIX_CLASS),
178 #endif
179 };
180 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
181 }
182
183 // Configure IPv6-options
184 int val = 1;
185 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
186 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
187 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
188 val = 0;
189 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
190 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
191
192 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
193 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
194 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
195 return -1;
196
197 return 0;
198 }
199
200
201 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
202 {
203 na_mode = na;
204 pd_mode = pd;
205 }
206
207 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
208 {
209 // Build FQDN
210 char fqdn_buf[256];
211 gethostname(fqdn_buf, sizeof(fqdn_buf));
212 struct {
213 uint16_t type;
214 uint16_t len;
215 uint8_t flags;
216 uint8_t data[256];
217 } fqdn;
218 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
219 sizeof(fqdn.data), NULL, NULL);
220 fqdn.type = htons(DHCPV6_OPT_FQDN);
221 fqdn.len = htons(fqdn_len - 4);
222 fqdn.flags = 0;
223
224
225 // Build Client ID
226 size_t cl_id_len;
227 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
228
229 // Get Server ID
230 size_t srv_id_len;
231 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
232
233 // Build IA_PDs
234 size_t ia_pd_entries, ia_pd_len = 0;
235 uint8_t *ia_pd;
236
237 if (type == DHCPV6_MSG_SOLICIT) {
238 odhcp6c_clear_state(STATE_IA_PD);
239 size_t n_prefixes;
240 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
241 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
242
243 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
244
245 for (size_t i = 0; i < n_prefixes; i++) {
246 struct dhcpv6_ia_hdr hdr_ia_pd = {
247 htons(DHCPV6_OPT_IA_PD),
248 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
249 request_prefixes[i].iaid, 0, 0
250 };
251 struct dhcpv6_ia_prefix pref = {
252 .type = htons(DHCPV6_OPT_IA_PREFIX),
253 .len = htons(25), .prefix = request_prefixes[i].length
254 };
255 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
256 ia_pd_len += sizeof(hdr_ia_pd);
257 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
258 ia_pd_len += sizeof(pref);
259 }
260 } else {
261 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
262 ia_pd_entries /= sizeof(*e);
263
264 // we're too lazy to count our distinct IAIDs,
265 // so just allocate maximally needed space
266 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
267 sizeof(struct dhcpv6_ia_hdr)));
268
269 for (size_t i = 0; i < ia_pd_entries; ++i) {
270 uint32_t iaid = e[i].iaid;
271
272 // check if this is an unprocessed IAID and skip if not.
273 int new_iaid = 1;
274 for (int j = i-1; j >= 0; j--) {
275 if (e[j].iaid == iaid) {
276 new_iaid = 0;
277 break;
278 }
279 }
280
281 if (!new_iaid)
282 continue;
283
284 // construct header
285 struct dhcpv6_ia_hdr hdr_ia_pd = {
286 htons(DHCPV6_OPT_IA_PD),
287 htons(sizeof(hdr_ia_pd) - 4),
288 iaid, 0, 0
289 };
290
291 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
292 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
293 ia_pd_len += sizeof(hdr_ia_pd);
294
295 for (size_t j = i; j < ia_pd_entries; j++) {
296 if (e[j].iaid != iaid)
297 continue;
298
299 uint8_t ex_len = 0;
300 if (e[j].priority > 0)
301 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
302
303 struct dhcpv6_ia_prefix p = {
304 .type = htons(DHCPV6_OPT_IA_PREFIX),
305 .len = htons(sizeof(p) - 4U + ex_len),
306 .prefix = e[j].length,
307 .addr = e[j].target
308 };
309
310 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
311 ia_pd_len += sizeof(p);
312
313 if (ex_len) {
314 ia_pd[ia_pd_len++] = 0;
315 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
316 ia_pd[ia_pd_len++] = 0;
317 ia_pd[ia_pd_len++] = ex_len - 4;
318 ia_pd[ia_pd_len++] = e[j].priority;
319
320 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
321 excl >>= (64 - e[j].priority);
322 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
323
324 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
325 ia_pd[ia_pd_len + i] = excl & 0xff;
326 ia_pd_len += ex_len - 5;
327 }
328
329 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
330 }
331 }
332 }
333
334 if (ia_pd_entries > 0)
335 request_prefix = 1;
336
337 // Build IA_NAs
338 size_t ia_na_entries, ia_na_len = 0;
339 void *ia_na = NULL;
340 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
341 ia_na_entries /= sizeof(*e);
342
343 struct dhcpv6_ia_hdr hdr_ia_na = {
344 htons(DHCPV6_OPT_IA_NA),
345 htons(sizeof(hdr_ia_na) - 4),
346 1, 0, 0
347 };
348
349 struct dhcpv6_ia_addr pa[ia_na_entries];
350 for (size_t i = 0; i < ia_na_entries; ++i) {
351 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
352 pa[i].len = htons(sizeof(pa[i]) - 4U);
353 pa[i].addr = e[i].target;
354 pa[i].preferred = 0;
355 pa[i].valid = 0;
356 }
357
358 ia_na = pa;
359 ia_na_len = sizeof(pa);
360 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
361
362 // Reconfigure Accept
363 struct {
364 uint16_t type;
365 uint16_t length;
366 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
367
368 // Request Information Refresh
369 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
370
371 // Build vendor-class option
372 size_t vendor_class_len;
373 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
374
375 struct {
376 uint16_t type;
377 uint16_t length;
378 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
379
380 // Prepare Header
381 size_t oro_len;
382 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
383 struct {
384 uint8_t type;
385 uint8_t trid[3];
386 uint16_t elapsed_type;
387 uint16_t elapsed_len;
388 uint16_t elapsed_value;
389 uint16_t oro_type;
390 uint16_t oro_len;
391 } hdr = {
392 type, {trid[0], trid[1], trid[2]},
393 htons(DHCPV6_OPT_ELAPSED), htons(2),
394 htons((ecs > 0xffff) ? 0xffff : ecs),
395 htons(DHCPV6_OPT_ORO), htons(oro_len),
396 };
397
398 struct iovec iov[] = {
399 {&hdr, sizeof(hdr)},
400 {oro, oro_len},
401 {&oro_refresh, 0},
402 {cl_id, cl_id_len},
403 {srv_id, srv_id_len},
404 {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
405 {vendor_class, vendor_class_len},
406 {&reconf_accept, sizeof(reconf_accept)},
407 {&fqdn, fqdn_len},
408 {&hdr_ia_na, sizeof(hdr_ia_na)},
409 {ia_na, ia_na_len},
410 {ia_pd, ia_pd_len},
411 };
412
413 size_t cnt = ARRAY_SIZE(iov);
414 if (type == DHCPV6_MSG_INFO_REQ) {
415 cnt = 7;
416 iov[2].iov_len = sizeof(oro_refresh);
417 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
418 } else if (!request_prefix) {
419 cnt = 11;
420 }
421
422 // Disable IAs if not used
423 if (type != DHCPV6_MSG_SOLICIT) {
424 iov[7].iov_len = 0;
425 if (ia_na_len == 0)
426 iov[9].iov_len = 0;
427 }
428
429 if (na_mode == IA_MODE_NONE)
430 iov[9].iov_len = 0;
431
432 if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
433 iov[7].iov_len = 0;
434
435 if (!(client_options & DHCPV6_CLIENT_FQDN))
436 iov[8].iov_len = 0;
437
438 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
439 0, ALL_DHCPV6_RELAYS, ifindex};
440 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
441
442 sendmsg(sock, &msg, 0);
443 }
444
445
446 static int64_t dhcpv6_rand_delay(int64_t time)
447 {
448 int random;
449 odhcp6c_random(&random, sizeof(random));
450 return (time * ((int64_t)random % 1000LL)) / 10000LL;
451 }
452
453
454 int dhcpv6_request(enum dhcpv6_msg type)
455 {
456 uint8_t rc = 0;
457 uint64_t timeout = UINT32_MAX;
458 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
459
460 if (retx->delay) {
461 struct timespec ts = {0, 0};
462 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
463 nanosleep(&ts, NULL);
464 }
465
466 if (type == DHCPV6_MSG_UNKNOWN)
467 timeout = t1;
468 else if (type == DHCPV6_MSG_RENEW)
469 timeout = (t2 > t1) ? t2 - t1 : 0;
470 else if (type == DHCPV6_MSG_REBIND)
471 timeout = (t3 > t2) ? t3 - t2 : 0;
472
473 if (timeout == 0)
474 return -1;
475
476 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
477 retx->name, (unsigned long long)timeout, retx->max_rc);
478
479 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
480
481 // Generate transaction ID
482 uint8_t trid[3] = {0, 0, 0};
483 if (type != DHCPV6_MSG_UNKNOWN)
484 odhcp6c_random(trid, sizeof(trid));
485 ssize_t len = -1;
486 int64_t rto = 0;
487
488 do {
489 if (rto == 0) {
490 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
491
492 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
493 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
494 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
495
496 rto = (retx->init_timeo * 1000 + delay);
497 }
498 else
499 rto = (2 * rto + dhcpv6_rand_delay(rto));
500
501 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
502 rto = retx->max_timeo * 1000 +
503 dhcpv6_rand_delay(retx->max_timeo * 1000);
504
505 // Calculate end for this round and elapsed time
506 uint64_t round_end = round_start + rto;
507 elapsed = round_start - start;
508
509 // Don't wait too long
510 if (round_end - start > timeout * 1000)
511 round_end = timeout * 1000 + start;
512
513 // Built and send package
514 if (type != DHCPV6_MSG_UNKNOWN) {
515 if (type != DHCPV6_MSG_SOLICIT)
516 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
517 retx->name, (unsigned long long)elapsed, rc);
518 dhcpv6_send(type, trid, elapsed / 10);
519 rc++;
520 }
521
522 // Receive rounds
523 for (; len < 0 && (round_start < round_end);
524 round_start = odhcp6c_get_milli_time()) {
525 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
526 struct iovec iov = {buf, sizeof(buf)};
527 struct msghdr msg = {NULL, 0, &iov, 1,
528 cmsg_buf, sizeof(cmsg_buf), 0};
529 struct in6_pktinfo *pktinfo = NULL;
530
531 // Check for pending signal
532 if (odhcp6c_signal_process())
533 return -1;
534
535 // Set timeout for receiving
536 uint64_t t = round_end - round_start;
537 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
538 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
539 &timeout, sizeof(timeout));
540
541 // Receive cycle
542 len = recvmsg(sock, &msg, 0);
543 if (len < 0)
544 continue;
545
546 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
547 ch = CMSG_NXTHDR(&msg, ch)) {
548 if (ch->cmsg_level == SOL_IPV6 &&
549 ch->cmsg_type == IPV6_PKTINFO) {
550 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
551 break;
552 }
553 }
554
555 if (pktinfo == NULL) {
556 len = -1;
557 continue;
558 }
559
560 if (!dhcpv6_response_is_valid(buf, len, trid,
561 type, &pktinfo->ipi6_addr)) {
562 len = -1;
563 continue;
564 }
565
566 uint8_t *opt = &buf[4];
567 uint8_t *opt_end = opt + len - 4;
568
569 round_start = odhcp6c_get_milli_time();
570 elapsed = round_start - start;
571 syslog(LOG_NOTICE, "Got a valid reply after "
572 "%llums", (unsigned long long)elapsed);
573
574 if (retx->handler_reply)
575 len = retx->handler_reply(type, rc, opt, opt_end);
576
577 if (len > 0 && round_end - round_start > 1000)
578 round_end = 1000 + round_start;
579 }
580
581 // Allow
582 if (retx->handler_finish)
583 len = retx->handler_finish();
584 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
585
586 return len;
587 }
588
589 // Message validation checks according to RFC3315 chapter 15
590 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
591 const uint8_t transaction[3], enum dhcpv6_msg type,
592 const struct in6_addr *daddr)
593 {
594 const struct dhcpv6_header *rep = buf;
595 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
596 transaction, sizeof(rep->tr_id)))
597 return false; // Invalid reply
598
599 if (type == DHCPV6_MSG_SOLICIT) {
600 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
601 rep->msg_type != DHCPV6_MSG_REPLY)
602 return false;
603 } else if (type == DHCPV6_MSG_UNKNOWN) {
604 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
605 return false;
606 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
607 return false;
608 }
609
610 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
611 rcmsg = DHCPV6_MSG_UNKNOWN;
612 uint16_t otype, olen = UINT16_MAX;
613 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
614 ia_present = false, options_valid = true;
615
616 size_t client_id_len, server_id_len;
617 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
618 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
619
620 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
621 if (otype == DHCPV6_OPT_CLIENTID) {
622 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
623 &odata[-4], client_id, client_id_len);
624 } else if (otype == DHCPV6_OPT_SERVERID) {
625 if (server_id_len)
626 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
627 &odata[-4], server_id, server_id_len);
628 else
629 serverid_ok = true;
630 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
631 sizeof(struct dhcpv6_auth_reconfigure)) {
632 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
633 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
634 continue;
635
636 md5_ctx_t md5;
637 uint8_t serverhash[16], secretbytes[16], hash[16];
638 memcpy(serverhash, r->key, sizeof(serverhash));
639 memset(r->key, 0, sizeof(r->key));
640 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
641
642 for (size_t i = 0; i < sizeof(secretbytes); ++i)
643 secretbytes[i] ^= 0x36;
644
645 md5_begin(&md5);
646 md5_hash(secretbytes, sizeof(secretbytes), &md5);
647 md5_hash(buf, len, &md5);
648 md5_end(hash, &md5);
649
650 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
651 secretbytes[i] ^= 0x36;
652 secretbytes[i] ^= 0x5c;
653 }
654
655 md5_begin(&md5);
656 md5_hash(secretbytes, sizeof(secretbytes), &md5);
657 md5_hash(hash, 16, &md5);
658 md5_end(hash, &md5);
659
660 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
661 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
662 rcmsg = odata[0];
663 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
664 ia_present = true;
665 if (olen < sizeof(struct dhcpv6_ia_hdr))
666 options_valid = false;
667 }
668 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
669 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
670 // Options are not allowed on global level
671 options_valid = false;
672 }
673 }
674
675 if (!options_valid || ((odata + olen) > end))
676 return false;
677
678 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
679 return false;
680
681 if (rep->msg_type == DHCPV6_MSG_RECONF) {
682 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
683 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
684 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
685 return false;
686 }
687
688 return clientid_ok && serverid_ok;
689 }
690
691
692 int dhcpv6_poll_reconfigure(void)
693 {
694 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
695 if (ret != -1)
696 ret = dhcpv6_request(ret);
697
698 return ret;
699 }
700
701
702 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
703 const void *opt, const void *end)
704 {
705 uint16_t otype, olen;
706 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
707 dhcpv6_for_each_option(opt, end, otype, olen, odata)
708 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
709 odata[0] == DHCPV6_MSG_RENEW ||
710 odata[0] == DHCPV6_MSG_INFO_REQ))
711 msg = odata[0];
712
713 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
714 return msg;
715 }
716
717
718 // Collect all advertised servers
719 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
720 const void *opt, const void *end)
721 {
722 uint16_t olen, otype;
723 uint8_t *odata, pref = 0;
724 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
725 DHCPV6_SOL_MAX_RT,
726 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
727 bool have_na = false;
728 int have_pd = 0;
729
730 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
731 if (orig == DHCPV6_MSG_SOLICIT &&
732 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
733 olen > sizeof(struct dhcpv6_ia_hdr)) {
734 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
735 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
736 }
737
738 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
739 memcpy(cand.duid, odata, olen);
740 cand.duid_len = olen;
741 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
742 int error = ((int)odata[0] << 8 | (int)odata[1]);
743
744 switch (error) {
745 case DHCPV6_NoPrefixAvail:
746 // Status code on global level
747 cand.preference -= 2000;
748 break;
749
750 default :
751 break;
752 }
753 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
754 cand.preference >= 0) {
755 cand.preference = pref = odata[0];
756 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
757 cand.wants_reconfigure = true;
758 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
759 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
760 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
761 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
762 cand.sol_max_rt = sol_max_rt;
763 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
764 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
765 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
766 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
767 cand.inf_max_rt = inf_max_rt;
768 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
769 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
770 uint8_t *oend = odata + olen, *d;
771 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
772 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
773 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
774 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
775 have_pd = p->prefix;
776 }
777 }
778 } else if (otype == DHCPV6_OPT_IA_NA) {
779 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
780 uint8_t *oend = odata + olen, *d;
781 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
782 if (otype == DHCPV6_OPT_IA_ADDR)
783 have_na = true;
784 }
785 }
786
787 if ((!have_na && na_mode == IA_MODE_FORCE) ||
788 (!have_pd && pd_mode == IA_MODE_FORCE)) {
789 /*
790 * RFC7083 states to process the SOL_MAX_RT and
791 * INF_MAX_RT options even if the DHCPv6 server
792 * did not propose any IA_NA and/or IA_PD
793 */
794 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
795 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
796 return -1;
797 }
798
799 if (na_mode != IA_MODE_NONE && !have_na) {
800 cand.has_noaddravail = true;
801 cand.preference -= 1000;
802 }
803
804 if (pd_mode != IA_MODE_NONE) {
805 if (have_pd)
806 cand.preference += 2000 + (128 - have_pd);
807 else
808 cand.preference -= 2000;
809 }
810
811 if (cand.duid_len > 0) {
812 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
813 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
814 dhcpv6_add_server_cand(&cand);
815 }
816
817 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
818 }
819
820
821 static int dhcpv6_commit_advert(void)
822 {
823 return dhcpv6_promote_server_cand();
824 }
825
826
827 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
828 const void *opt, const void *end)
829 {
830 dhcpv6_handle_advert(orig, rc, opt, end);
831 if (dhcpv6_commit_advert() < 0)
832 return -1;
833
834 return dhcpv6_handle_reply(orig, rc, opt, end);
835 }
836
837
838 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
839 const void *opt, const void *end)
840 {
841 uint8_t *odata;
842 uint16_t otype, olen;
843 uint32_t refresh = UINT32_MAX;
844 int ret = 1;
845 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
846
847 odhcp6c_expire();
848
849 if (orig == DHCPV6_MSG_UNKNOWN) {
850 static time_t last_update = 0;
851 time_t now = odhcp6c_get_milli_time() / 1000;
852
853 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
854 last_update = now;
855
856 t1 -= elapsed;
857 t2 -= elapsed;
858 t3 -= elapsed;
859
860 if (t1 < 0)
861 t1 = 0;
862
863 if (t2 < 0)
864 t2 = 0;
865
866 if (t3 < 0)
867 t3 = 0;
868 }
869
870 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
871 // Delete NA and PD we have in the state from the Advert
872 odhcp6c_clear_state(STATE_IA_NA);
873 odhcp6c_clear_state(STATE_IA_PD);
874 }
875
876 if (opt) {
877 odhcp6c_clear_state(STATE_DNS);
878 odhcp6c_clear_state(STATE_SEARCH);
879 odhcp6c_clear_state(STATE_SNTP_IP);
880 odhcp6c_clear_state(STATE_NTP_IP);
881 odhcp6c_clear_state(STATE_NTP_FQDN);
882 odhcp6c_clear_state(STATE_SIP_IP);
883 odhcp6c_clear_state(STATE_SIP_FQDN);
884 odhcp6c_clear_state(STATE_AFTR_NAME);
885 }
886
887 // Parse and find all matching IAs
888 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
889 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
890 && olen > sizeof(struct dhcpv6_ia_hdr)) {
891 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
892
893 // Test ID
894 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
895 continue;
896
897 uint16_t code = DHCPV6_Success;
898 uint16_t stype, slen;
899 uint8_t *sdata;
900 // Get and handle status code
901 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
902 stype, slen, sdata) {
903 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
904 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
905 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
906
907 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
908
909 if (code == DHCPV6_Success)
910 continue;
911
912 dhcpv6_handle_ia_status_code(orig, ia_hdr,
913 code, mdata, mlen, handled_status_codes, &ret);
914
915
916 if (ret > 0)
917 return ret;
918 break;
919 }
920 }
921
922 if (code != DHCPV6_Success)
923 continue;
924
925 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
926 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
927 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
928 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
929 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
930
931 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
932 }
933 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
934 if (olen % 16 == 0)
935 odhcp6c_add_state(STATE_DNS, odata, olen);
936 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
937 odhcp6c_add_state(STATE_SEARCH, odata, olen);
938 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
939 if (olen % 16 == 0)
940 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
941 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
942 uint16_t stype, slen;
943 uint8_t *sdata;
944 // Test status and bail if error
945 dhcpv6_for_each_option(odata, odata + olen,
946 stype, slen, sdata) {
947 if (slen == 16 && (stype == NTP_MC_ADDR ||
948 stype == NTP_SRV_ADDR))
949 odhcp6c_add_state(STATE_NTP_IP,
950 sdata, slen);
951 else if (slen > 0 && stype == NTP_SRV_FQDN)
952 odhcp6c_add_state(STATE_NTP_FQDN,
953 sdata, slen);
954 }
955 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
956 if (olen == 16)
957 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
958 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
959 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
960 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
961 refresh = ntohl(*((uint32_t*)odata));
962 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
963 sizeof(struct dhcpv6_auth_reconfigure)) {
964 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
965 if (r->protocol == 3 && r->algorithm == 1 &&
966 r->reconf_type == 1)
967 memcpy(reconf_key, r->key, sizeof(r->key));
968 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
969 size_t cur_len;
970 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
971 if (cur_len == 0)
972 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
973 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
974 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
975 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
976 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
977 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
978 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
979 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
980 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
981 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
982 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
983 }else if (otype != DHCPV6_OPT_CLIENTID &&
984 otype != DHCPV6_OPT_SERVERID) {
985 odhcp6c_add_state(STATE_CUSTOM_OPTS,
986 &odata[-4], olen + 4);
987 }
988 }
989
990 if (orig != DHCPV6_MSG_INFO_REQ) {
991 // Update refresh timers if no fatal status code was received
992 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
993 switch (orig) {
994 case DHCPV6_MSG_RENEW:
995 // Send further renews if T1 is not set
996 if (!t1)
997 ret = -1;
998 break;
999 case DHCPV6_MSG_REBIND:
1000 // Send further rebinds if T1 and T2 is not set
1001 if (!t1 && !t2)
1002 ret = -1;
1003 break;
1004
1005 case DHCPV6_MSG_REQUEST:
1006 // All server candidates can be cleared if not yet bound
1007 if (!odhcp6c_is_bound())
1008 dhcpv6_clear_all_server_cand();
1009
1010 default :
1011 break;
1012 }
1013 }
1014 }
1015 else if (ret > 0) {
1016 // All server candidates can be cleared if not yet bound
1017 if (!odhcp6c_is_bound())
1018 dhcpv6_clear_all_server_cand();
1019
1020 t1 = refresh;
1021 }
1022
1023 return ret;
1024 }
1025
1026
1027 static int dhcpv6_parse_ia(void *opt, void *end)
1028 {
1029 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1030 int parsed_ia = 0;
1031 uint32_t t1, t2;
1032 uint16_t otype, olen;
1033 uint8_t *odata;
1034
1035 t1 = ntohl(ia_hdr->t1);
1036 t2 = ntohl(ia_hdr->t2);
1037
1038 if (t1 > t2)
1039 return 0;
1040
1041 // Update address IA
1042 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1043 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1044 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1045
1046 entry.iaid = ia_hdr->iaid;
1047
1048 if (otype == DHCPV6_OPT_IA_PREFIX) {
1049 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1050 if (olen + 4U < sizeof(*prefix))
1051 continue;
1052
1053 entry.valid = ntohl(prefix->valid);
1054 entry.preferred = ntohl(prefix->preferred);
1055
1056 if (entry.preferred > entry.valid)
1057 continue;
1058
1059 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1060 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1061 if (entry.t1 > entry.t2)
1062 entry.t1 = entry.t2;
1063
1064 entry.length = prefix->prefix;
1065 entry.target = prefix->addr;
1066 uint16_t stype, slen;
1067 uint8_t *sdata;
1068
1069 #ifdef EXT_PREFIX_CLASS
1070 // Find prefix class, if any
1071 dhcpv6_for_each_option(&prefix[1], odata + olen,
1072 stype, slen, sdata)
1073 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1074 entry.class = sdata[0] << 8 | sdata[1];
1075 #endif
1076
1077 // Parse PD-exclude
1078 bool ok = true;
1079 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1080 odata + olen, stype, slen, sdata) {
1081 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1082 continue;
1083
1084 uint8_t elen = sdata[0];
1085 if (elen > 64)
1086 elen = 64;
1087
1088 if (elen <= 32 || elen <= entry.length) {
1089 ok = false;
1090 continue;
1091 }
1092
1093
1094 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1095 if (slen <= bytes) {
1096 ok = false;
1097 continue;
1098 }
1099
1100 uint32_t exclude = 0;
1101 do {
1102 exclude = exclude << 8 | sdata[bytes];
1103 } while (--bytes);
1104
1105 exclude >>= 8 - ((elen - entry.length) % 8);
1106 exclude <<= 64 - elen;
1107
1108 // Abusing router & priority fields for exclusion
1109 entry.router = entry.target;
1110 entry.router.s6_addr32[1] |= htonl(exclude);
1111 entry.priority = elen;
1112 }
1113
1114 if (ok) {
1115 odhcp6c_update_entry(STATE_IA_PD, &entry);
1116 parsed_ia++;
1117 }
1118
1119 entry.priority = 0;
1120 memset(&entry.router, 0, sizeof(entry.router));
1121 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1122 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1123 if (olen + 4U < sizeof(*addr))
1124 continue;
1125
1126 entry.preferred = ntohl(addr->preferred);
1127 entry.valid = ntohl(addr->valid);
1128
1129 if (entry.preferred > entry.valid)
1130 continue;
1131
1132 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1133 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1134 if (entry.t1 > entry.t2)
1135 entry.t1 = entry.t2;
1136
1137 entry.length = 128;
1138 entry.target = addr->addr;
1139
1140 #ifdef EXT_PREFIX_CLASS
1141 uint16_t stype, slen;
1142 uint8_t *sdata;
1143 // Find prefix class, if any
1144 dhcpv6_for_each_option(&addr[1], odata + olen,
1145 stype, slen, sdata)
1146 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1147 entry.class = sdata[0] << 8 | sdata[1];
1148 #endif
1149
1150 odhcp6c_update_entry(STATE_IA_NA, &entry);
1151 parsed_ia++;
1152 }
1153 }
1154 return parsed_ia;
1155 }
1156
1157
1158 static int dhcpv6_calc_refresh_timers(void)
1159 {
1160 struct odhcp6c_entry *e;
1161 size_t ia_na_entries, ia_pd_entries, i;
1162 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1163
1164 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1165 ia_na_entries /= sizeof(*e);
1166 for (i = 0; i < ia_na_entries; i++) {
1167 if (e[i].t1 < l_t1)
1168 l_t1 = e[i].t1;
1169
1170 if (e[i].t2 < l_t2)
1171 l_t2 = e[i].t2;
1172
1173 if (e[i].valid > l_t3)
1174 l_t3 = e[i].valid;
1175 }
1176
1177 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1178 ia_pd_entries /= sizeof(*e);
1179 for (i = 0; i < ia_pd_entries; i++) {
1180 if (e[i].t1 < l_t1)
1181 l_t1 = e[i].t1;
1182
1183 if (e[i].t2 < l_t2)
1184 l_t2 = e[i].t2;
1185
1186 if (e[i].valid > l_t3)
1187 l_t3 = e[i].valid;
1188 }
1189
1190 if (ia_pd_entries || ia_na_entries) {
1191 t1 = l_t1;
1192 t2 = l_t2;
1193 t3 = l_t3;
1194 } else {
1195 t1 = 600;
1196 }
1197
1198 return (int)(ia_pd_entries + ia_na_entries);
1199 }
1200
1201
1202 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1203 const void *status_msg, const int len)
1204 {
1205 uint8_t buf[len + 3];
1206
1207 memset(buf, 0, sizeof(buf));
1208 if (len) {
1209 buf[0] = '(';
1210 memcpy(&buf[1], status_msg, len);
1211 buf[len + 1] = ')';
1212 }
1213
1214 syslog(LOG_WARNING, "Server returned %s status %i %s",
1215 scope, code, buf);
1216 }
1217
1218
1219 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1220 const uint16_t code, const void *status_msg, const int len,
1221 int *ret)
1222 {
1223 dhcpv6_log_status_code(code, "message", status_msg, len);
1224
1225 switch (code) {
1226 case DHCPV6_UnspecFail:
1227 // Generic failure
1228 *ret = 0;
1229 break;
1230
1231 case DHCPV6_UseMulticast:
1232 // TODO handle multicast status code
1233 break;
1234
1235 case DHCPV6_NoAddrsAvail:
1236 case DHCPV6_NoPrefixAvail:
1237 if (orig == DHCPV6_MSG_REQUEST)
1238 *ret = 0; // Failure
1239 break;
1240
1241 default:
1242 break;
1243 }
1244 }
1245
1246
1247 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1248 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1249 const void *status_msg, const int len,
1250 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1251 {
1252 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1253 "IA_NA" : "IA_PD", status_msg, len);
1254
1255 switch (code) {
1256 case DHCPV6_NoBinding:
1257 switch (orig) {
1258 case DHCPV6_MSG_RENEW:
1259 case DHCPV6_MSG_REBIND:
1260 if ((*ret > 0) && !handled_status_codes[code])
1261 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1262 break;
1263
1264 default:
1265 break;
1266 }
1267 break;
1268
1269 case DHCPV6_NoAddrsAvail:
1270 case DHCPV6_NoPrefixAvail:
1271 switch (orig) {
1272 case DHCPV6_MSG_REQUEST:
1273 if (*ret != 0)
1274 *ret = 0;
1275 break;
1276 default:
1277 break;
1278 }
1279 break;
1280
1281 case DHCPV6_NotOnLink:
1282 // TODO handle not onlink in case of confirm
1283 break;
1284
1285 default:
1286 break;
1287 }
1288 }
1289
1290 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1291 {
1292 size_t cand_len, i;
1293 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1294
1295 // Remove identical duid server candidate
1296 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1297 if (cand->duid_len == c[i].duid_len &&
1298 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1299 free(c[i].ia_na);
1300 free(c[i].ia_pd);
1301 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1302 break;
1303 }
1304 }
1305
1306 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1307 i < cand_len / sizeof(*c); ++i) {
1308 if (c[i].preference < cand->preference)
1309 break;
1310 }
1311
1312 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1313 }
1314
1315 static void dhcpv6_clear_all_server_cand(void)
1316 {
1317 size_t cand_len, i;
1318 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1319
1320 // Server candidates need deep delete for IA_NA/IA_PD
1321 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1322 free(c[i].ia_na);
1323 free(c[i].ia_pd);
1324 }
1325 odhcp6c_clear_state(STATE_SERVER_CAND);
1326 }
1327
1328 int dhcpv6_promote_server_cand(void)
1329 {
1330 size_t cand_len;
1331 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1332 uint16_t hdr[2];
1333 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1334 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1335
1336 // Clear lingering candidate state info
1337 odhcp6c_clear_state(STATE_SERVER_ID);
1338 odhcp6c_clear_state(STATE_IA_NA);
1339 odhcp6c_clear_state(STATE_IA_PD);
1340
1341 if (!cand_len)
1342 return -1;
1343
1344 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1345 na_mode = IA_MODE_NONE;
1346
1347 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1348 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1349
1350 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1351 }
1352
1353 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1354 hdr[1] = htons(cand->duid_len);
1355 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1356 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1357 accept_reconfig = cand->wants_reconfigure;
1358 if (cand->ia_na_len) {
1359 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1360 free(cand->ia_na);
1361 if (na_mode != IA_MODE_NONE)
1362 ret = DHCPV6_STATEFUL;
1363 }
1364 if (cand->ia_pd_len) {
1365 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1366 free(cand->ia_pd);
1367 if (request_prefix)
1368 ret = DHCPV6_STATEFUL;
1369 }
1370
1371 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1372 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1373
1374 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1375
1376 return ret;
1377 }
Openwrt DHCPv6 Client