projects / project / odhcp6c.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
dhcpv6: add a minimum valid lifetime for IA_PD updates
[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
3 * Copyright (C) 2017-2018 Hans Dedecker <dedeckeh@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License v2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16 #include <time.h>
17 #include <fcntl.h>
18 #include <errno.h>
19 #include <inttypes.h>
20 #include <stdlib.h>
21 #include <signal.h>
22 #include <limits.h>
23 #include <resolv.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <syslog.h>
27 #include <stdbool.h>
28 #include <ctype.h>
29 #include <sys/time.h>
30 #include <sys/ioctl.h>
31 #include <sys/socket.h>
32 #include <arpa/inet.h>
33 #include <netinet/in.h>
34
35 #include <net/if.h>
36 #include <net/ethernet.h>
37
38 #include "odhcp6c.h"
39 #ifdef USE_LIBUBOX
40 #include <libubox/md5.h>
41 #else
42 #include "md5.h"
43 #endif
44
45
46 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
47 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
48 #define DHCPV6_CLIENT_PORT 546
49 #define DHCPV6_SERVER_PORT 547
50 #define DHCPV6_DUID_LLADDR 3
51 #define DHCPV6_REQ_DELAY 1
52
53 #define DHCPV6_SOL_MAX_RT_MIN 60
54 #define DHCPV6_SOL_MAX_RT_MAX 86400
55 #define DHCPV6_INF_MAX_RT_MIN 60
56 #define DHCPV6_INF_MAX_RT_MAX 86400
57
58 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
59 const uint8_t transaction[3], enum dhcpv6_msg type,
60 const struct in6_addr *daddr);
61
62 static unsigned int dhcpv6_parse_ia(void *opt, void *end);
63
64 static unsigned int dhcpv6_calc_refresh_timers(void);
65 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
66 const uint16_t code, const void *status_msg, const int len,
67 int *ret);
68 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
69 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
70 const void *status_msg, const int len,
71 bool handled_status_codes[_DHCPV6_Status_Max],
72 int *ret);
73 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
74 static void dhcpv6_clear_all_server_cand(void);
75
76 static reply_handler dhcpv6_handle_reply;
77 static reply_handler dhcpv6_handle_advert;
78 static reply_handler dhcpv6_handle_rebind_reply;
79 static reply_handler dhcpv6_handle_reconfigure;
80 static int dhcpv6_commit_advert(void);
81
82 // RFC 3315 - 5.5 Timeout and Delay values
83 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
84 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
85 dhcpv6_handle_reconfigure, NULL},
86 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
87 dhcpv6_handle_advert, dhcpv6_commit_advert},
88 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
89 dhcpv6_handle_reply, NULL},
90 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
91 dhcpv6_handle_reply, NULL},
92 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
93 dhcpv6_handle_rebind_reply, NULL},
94 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
95 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
96 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
97 dhcpv6_handle_reply, NULL},
98 };
99
100 // Sockets
101 static int sock = -1;
102 static int ifindex = -1;
103 static int64_t t1 = 0, t2 = 0, t3 = 0;
104
105 // IA states
106 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
107 static bool accept_reconfig = false;
108 // Server unicast address
109 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
110
111 // Reconfigure key
112 static uint8_t reconf_key[16];
113
114 // client options
115 static unsigned int client_options = 0;
116
117 // Minimum valid lifetime for IA_PD updates
118 static unsigned int pd_safe_valid = 0;
119
120 static uint32_t ntohl_unaligned(const uint8_t *data)
121 {
122 uint32_t buf;
123
124 memcpy(&buf, data, sizeof(buf));
125 return ntohl(buf);
126 }
127
128 static char *dhcpv6_msg_to_str(enum dhcpv6_msg msg)
129 {
130 switch (msg) {
131 case DHCPV6_MSG_SOLICIT:
132 return "SOLICIT";
133
134 case DHCPV6_MSG_ADVERT:
135 return "ADVERTISE";
136
137 case DHCPV6_MSG_REQUEST:
138 return "REQUEST";
139
140 case DHCPV6_MSG_RENEW:
141 return "RENEW";
142
143 case DHCPV6_MSG_REBIND:
144 return "REBIND";
145
146 case DHCPV6_MSG_REPLY:
147 return "REPLY";
148
149 case DHCPV6_MSG_RELEASE:
150 return "RELEASE";
151
152 case DHCPV6_MSG_DECLINE:
153 return "DECLINE";
154
155 case DHCPV6_MSG_RECONF:
156 return "RECONFIGURE";
157
158 case DHCPV6_MSG_INFO_REQ:
159 return "INFORMATION REQUEST";
160
161 default:
162 break;
163 }
164
165 return "UNKNOWN";
166 }
167
168 static char *dhcpv6_status_code_to_str(uint16_t code)
169 {
170 switch (code) {
171 case DHCPV6_Success:
172 return "Success";
173
174 case DHCPV6_UnspecFail:
175 return "Unspecified Failure";
176
177 case DHCPV6_NoAddrsAvail:
178 return "No Address Available";
179
180 case DHCPV6_NoBinding:
181 return "No Binding";
182
183 case DHCPV6_NotOnLink:
184 return "Not On Link";
185
186 case DHCPV6_UseMulticast:
187 return "Use Multicast";
188
189 case DHCPV6_NoPrefixAvail:
190 return "No Prefix Available";
191
192 default:
193 break;
194 }
195
196 return "Unknown";
197 }
198
199 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout, unsigned int ia_pd_safe_valid)
200 {
201 client_options = options;
202 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
203 pd_safe_valid = ia_pd_safe_valid;
204
205 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
206 if (sock < 0)
207 goto failure;
208
209 // Detect interface
210 struct ifreq ifr;
211 memset(&ifr, 0, sizeof(ifr));
212 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
213 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
214 goto failure;
215
216 ifindex = ifr.ifr_ifindex;
217
218 // Create client DUID
219 size_t client_id_len;
220 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
221 if (client_id_len == 0) {
222 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
223 DHCPV6_DUID_LLADDR, 0, 1};
224
225 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
226 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
227
228 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
229 struct ifreq ifs[100], *ifp, *ifend;
230 struct ifconf ifc;
231 ifc.ifc_req = ifs;
232 ifc.ifc_len = sizeof(ifs);
233
234 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
235 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
236 // If our interface doesn't have an address...
237 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
238 for (ifp = ifc.ifc_req; ifp < ifend &&
239 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
240 memcpy(ifr.ifr_name, ifp->ifr_name,
241 sizeof(ifr.ifr_name));
242 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
243 continue;
244
245 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
246 ETHER_ADDR_LEN);
247 }
248 }
249
250 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
251 }
252
253 // Create ORO
254 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
255 uint16_t oro[] = {
256 htons(DHCPV6_OPT_SIP_SERVER_D),
257 htons(DHCPV6_OPT_SIP_SERVER_A),
258 htons(DHCPV6_OPT_DNS_SERVERS),
259 htons(DHCPV6_OPT_DNS_DOMAIN),
260 htons(DHCPV6_OPT_SNTP_SERVERS),
261 htons(DHCPV6_OPT_NTP_SERVER),
262 htons(DHCPV6_OPT_AFTR_NAME),
263 htons(DHCPV6_OPT_PD_EXCLUDE),
264 #ifdef EXT_CER_ID
265 htons(DHCPV6_OPT_CER_ID),
266 #endif
267 htons(DHCPV6_OPT_S46_CONT_MAPE),
268 htons(DHCPV6_OPT_S46_CONT_MAPT),
269 htons(DHCPV6_OPT_S46_CONT_LW),
270 };
271 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
272 }
273 // Required oro
274 uint16_t req_oro[] = {
275 htons(DHCPV6_OPT_INF_MAX_RT),
276 htons(DHCPV6_OPT_SOL_MAX_RT),
277 htons(DHCPV6_OPT_INFO_REFRESH),
278 };
279 odhcp6c_add_state(STATE_ORO, req_oro, sizeof(req_oro));
280
281 // Configure IPv6-options
282 int val = 1;
283 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
284 goto failure;
285
286 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
287 goto failure;
288
289 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
290 goto failure;
291
292 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
293 goto failure;
294
295 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
296 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
297
298 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
299 goto failure;
300
301 return 0;
302
303 failure:
304 if (sock >= 0)
305 close(sock);
306
307 return -1;
308 }
309
310 enum {
311 IOV_HDR=0,
312 IOV_ORO,
313 IOV_CL_ID,
314 IOV_SRV_ID,
315 IOV_OPTS,
316 IOV_RECONF_ACCEPT,
317 IOV_FQDN,
318 IOV_HDR_IA_NA,
319 IOV_IA_NA,
320 IOV_IA_PD,
321 IOV_TOTAL
322 };
323
324 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
325 {
326 int mode = DHCPV6_UNKNOWN;
327
328 na_mode = na;
329 pd_mode = pd;
330
331 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
332 mode = DHCPV6_STATELESS;
333 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
334 mode = DHCPV6_STATEFUL;
335
336 return mode;
337 }
338
339 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
340 {
341 // Build FQDN
342 char fqdn_buf[256];
343 gethostname(fqdn_buf, sizeof(fqdn_buf));
344 struct {
345 uint16_t type;
346 uint16_t len;
347 uint8_t flags;
348 uint8_t data[256];
349 } fqdn;
350 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
351 sizeof(fqdn.data), NULL, NULL);
352 fqdn.type = htons(DHCPV6_OPT_FQDN);
353 fqdn.len = htons(fqdn_len - 4);
354 fqdn.flags = 0;
355
356 // Build Client ID
357 size_t cl_id_len;
358 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
359
360 // Get Server ID
361 size_t srv_id_len;
362 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
363
364 // Build IA_PDs
365 size_t ia_pd_entries = 0, ia_pd_len = 0;
366 uint8_t *ia_pd;
367
368 if (type == DHCPV6_MSG_SOLICIT) {
369 odhcp6c_clear_state(STATE_IA_PD);
370 size_t n_prefixes;
371 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
372 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
373
374 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
375
376 for (size_t i = 0; i < n_prefixes; i++) {
377 struct dhcpv6_ia_hdr hdr_ia_pd = {
378 htons(DHCPV6_OPT_IA_PD),
379 htons(sizeof(hdr_ia_pd) - 4 +
380 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
381 request_prefixes[i].iaid, 0, 0
382 };
383 struct dhcpv6_ia_prefix pref = {
384 .type = htons(DHCPV6_OPT_IA_PREFIX),
385 .len = htons(sizeof(pref) - 4),
386 .prefix = request_prefixes[i].length
387 };
388 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
389 ia_pd_len += sizeof(hdr_ia_pd);
390 if (request_prefixes[i].length) {
391 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
392 ia_pd_len += sizeof(pref);
393 }
394 }
395 } else {
396 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
397 ia_pd_entries /= sizeof(*e);
398
399 // we're too lazy to count our distinct IAIDs,
400 // so just allocate maximally needed space
401 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
402 sizeof(struct dhcpv6_ia_hdr)));
403
404 for (size_t i = 0; i < ia_pd_entries; ++i) {
405 uint32_t iaid = e[i].iaid;
406
407 // check if this is an unprocessed IAID and skip if not.
408 int new_iaid = 1;
409 for (int j = i-1; j >= 0; j--) {
410 if (e[j].iaid == iaid) {
411 new_iaid = 0;
412 break;
413 }
414 }
415
416 if (!new_iaid)
417 continue;
418
419 // construct header
420 struct dhcpv6_ia_hdr hdr_ia_pd = {
421 htons(DHCPV6_OPT_IA_PD),
422 htons(sizeof(hdr_ia_pd) - 4),
423 iaid, 0, 0
424 };
425
426 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
427 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
428 ia_pd_len += sizeof(hdr_ia_pd);
429
430 for (size_t j = i; j < ia_pd_entries; j++) {
431 if (e[j].iaid != iaid)
432 continue;
433
434 uint8_t ex_len = 0;
435 if (e[j].priority > 0)
436 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
437
438 struct dhcpv6_ia_prefix p = {
439 .type = htons(DHCPV6_OPT_IA_PREFIX),
440 .len = htons(sizeof(p) - 4U + ex_len),
441 .prefix = e[j].length,
442 .addr = e[j].target
443 };
444
445 if (type == DHCPV6_MSG_REQUEST) {
446 p.preferred = htonl(e[j].preferred);
447 p.valid = htonl(e[j].valid);
448 }
449
450 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
451 ia_pd_len += sizeof(p);
452
453 if (ex_len) {
454 ia_pd[ia_pd_len++] = 0;
455 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
456 ia_pd[ia_pd_len++] = 0;
457 ia_pd[ia_pd_len++] = ex_len - 4;
458 ia_pd[ia_pd_len++] = e[j].priority;
459
460 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
461 excl >>= (64 - e[j].priority);
462 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
463
464 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
465 ia_pd[ia_pd_len + i] = excl & 0xff;
466 ia_pd_len += ex_len - 5;
467 }
468
469 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
470 }
471 }
472 }
473
474 // Build IA_NAs
475 size_t ia_na_entries, ia_na_len = 0;
476 void *ia_na = NULL;
477 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
478 ia_na_entries /= sizeof(*e);
479
480 struct dhcpv6_ia_hdr hdr_ia_na = {
481 htons(DHCPV6_OPT_IA_NA),
482 htons(sizeof(hdr_ia_na) - 4),
483 htonl(1), 0, 0
484 };
485
486 struct dhcpv6_ia_addr pa[ia_na_entries];
487 for (size_t i = 0; i < ia_na_entries; ++i) {
488 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
489 pa[i].len = htons(sizeof(pa[i]) - 4U);
490 pa[i].addr = e[i].target;
491
492 if (type == DHCPV6_MSG_REQUEST) {
493 pa[i].preferred = htonl(e[i].preferred);
494 pa[i].valid = htonl(e[i].valid);
495 } else {
496 pa[i].preferred = 0;
497 pa[i].valid = 0;
498 }
499 }
500
501 ia_na = pa;
502 ia_na_len = sizeof(pa);
503 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
504
505 // Reconfigure Accept
506 struct {
507 uint16_t type;
508 uint16_t length;
509 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
510
511 // Option list
512 size_t opts_len;
513 void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len);
514
515 // Option Request List
516 size_t oro_entries, oro_len = 0;
517 uint16_t *oro, *s_oro = odhcp6c_get_state(STATE_ORO, &oro_entries);
518
519 oro_entries /= sizeof(*s_oro);
520 oro = alloca(oro_entries * sizeof(*oro));
521
522 for (size_t i = 0; i < oro_entries; i++) {
523 struct odhcp6c_opt *opt = odhcp6c_find_opt(htons(s_oro[i]));
524
525 if (opt) {
526 if (!(opt->flags & OPT_ORO))
527 continue;
528
529 if ((opt->flags & OPT_ORO_SOLICIT) && type != DHCPV6_MSG_SOLICIT)
530 continue;
531
532 if ((opt->flags & OPT_ORO_STATELESS) && type != DHCPV6_MSG_INFO_REQ)
533 continue;
534
535 if ((opt->flags & OPT_ORO_STATEFUL) && type == DHCPV6_MSG_INFO_REQ)
536 continue;
537 }
538
539 oro[oro_len++] = s_oro[i];
540 }
541 oro_len *= sizeof(*oro);
542
543 // Prepare Header
544 struct {
545 uint8_t type;
546 uint8_t trid[3];
547 uint16_t elapsed_type;
548 uint16_t elapsed_len;
549 uint16_t elapsed_value;
550 uint16_t oro_type;
551 uint16_t oro_len;
552 } hdr = {
553 type, {trid[0], trid[1], trid[2]},
554 htons(DHCPV6_OPT_ELAPSED), htons(2),
555 htons((ecs > 0xffff) ? 0xffff : ecs),
556 htons(DHCPV6_OPT_ORO), htons(oro_len),
557 };
558
559 struct iovec iov[IOV_TOTAL] = {
560 [IOV_HDR] = {&hdr, sizeof(hdr)},
561 [IOV_ORO] = {oro, oro_len},
562 [IOV_CL_ID] = {cl_id, cl_id_len},
563 [IOV_SRV_ID] = {srv_id, srv_id_len},
564 [IOV_OPTS] = { opts, opts_len },
565 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
566 [IOV_FQDN] = {&fqdn, fqdn_len},
567 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
568 [IOV_IA_NA] = {ia_na, ia_na_len},
569 [IOV_IA_PD] = {ia_pd, ia_pd_len},
570 };
571
572 size_t cnt = IOV_TOTAL;
573 if (type == DHCPV6_MSG_INFO_REQ)
574 cnt = IOV_HDR_IA_NA;
575
576 // Disable IAs if not used
577 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
578 iov[IOV_HDR_IA_NA].iov_len = 0;
579
580 if (na_mode == IA_MODE_NONE)
581 iov[IOV_HDR_IA_NA].iov_len = 0;
582
583 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
584 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
585 iov[IOV_RECONF_ACCEPT].iov_len = 0;
586
587 if (!(client_options & DHCPV6_CLIENT_FQDN))
588 iov[IOV_FQDN].iov_len = 0;
589
590 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
591 0, ALL_DHCPV6_RELAYS, ifindex};
592 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
593 .msg_iov = iov, .msg_iovlen = cnt};
594
595 switch (type) {
596 case DHCPV6_MSG_REQUEST:
597 case DHCPV6_MSG_RENEW:
598 case DHCPV6_MSG_RELEASE:
599 case DHCPV6_MSG_DECLINE:
600 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
601 odhcp6c_addr_in_scope(&server_addr)) {
602 srv.sin6_addr = server_addr;
603 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
604 srv.sin6_scope_id = 0;
605 }
606 break;
607 default:
608 break;
609 }
610
611 if (sendmsg(sock, &msg, 0) < 0) {
612 char in6_str[INET6_ADDRSTRLEN];
613
614 syslog(LOG_ERR, "Failed to send %s message to %s (%s)",
615 dhcpv6_msg_to_str(type),
616 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
617 in6_str, sizeof(in6_str)), strerror(errno));
618 }
619 }
620
621 static int64_t dhcpv6_rand_delay(int64_t time)
622 {
623 int random;
624 odhcp6c_random(&random, sizeof(random));
625
626 return (time * ((int64_t)random % 1000LL)) / 10000LL;
627 }
628
629 int dhcpv6_request(enum dhcpv6_msg type)
630 {
631 uint8_t rc = 0;
632 uint64_t timeout = UINT32_MAX;
633 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
634
635 if (retx->delay) {
636 struct timespec ts = {0, 0};
637 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
638
639 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
640 }
641
642 if (type == DHCPV6_MSG_UNKNOWN)
643 timeout = t1;
644 else if (type == DHCPV6_MSG_RENEW)
645 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
646 else if (type == DHCPV6_MSG_REBIND)
647 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
648
649 if (timeout == 0)
650 return -1;
651
652 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
653 retx->name, timeout, retx->max_rc);
654
655 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
656
657 // Generate transaction ID
658 uint8_t trid[3] = {0, 0, 0};
659 if (type != DHCPV6_MSG_UNKNOWN)
660 odhcp6c_random(trid, sizeof(trid));
661
662 ssize_t len = -1;
663 int64_t rto = 0;
664
665 do {
666 if (rto == 0) {
667 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
668
669 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
670 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
671 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
672
673 rto = (retx->init_timeo * 1000 + delay);
674 } else
675 rto = (2 * rto + dhcpv6_rand_delay(rto));
676
677 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
678 rto = retx->max_timeo * 1000 +
679 dhcpv6_rand_delay(retx->max_timeo * 1000);
680
681 // Calculate end for this round and elapsed time
682 uint64_t round_end = round_start + rto;
683 elapsed = round_start - start;
684
685 // Don't wait too long if timeout differs from infinite
686 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
687 round_end = timeout * 1000 + start;
688
689 // Built and send package
690 switch (type) {
691 case DHCPV6_MSG_UNKNOWN:
692 break;
693 default:
694 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
695 retx->name, elapsed, rc);
696 // Fall through
697 case DHCPV6_MSG_SOLICIT:
698 case DHCPV6_MSG_INFO_REQ:
699 dhcpv6_send(type, trid, elapsed / 10);
700 rc++;
701 }
702
703 // Receive rounds
704 for (; len < 0 && (round_start < round_end);
705 round_start = odhcp6c_get_milli_time()) {
706 uint8_t buf[1536];
707 union {
708 struct cmsghdr hdr;
709 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
710 } cmsg_buf;
711 struct iovec iov = {buf, sizeof(buf)};
712 struct sockaddr_in6 addr;
713 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
714 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
715 .msg_controllen = sizeof(cmsg_buf)};
716 struct in6_pktinfo *pktinfo = NULL;
717 const struct dhcpv6_header *hdr = (const struct dhcpv6_header *)buf;
718
719 // Check for pending signal
720 if (odhcp6c_signal_process())
721 return -1;
722
723 // Set timeout for receiving
724 uint64_t t = round_end - round_start;
725 struct timeval tv = {t / 1000, (t % 1000) * 1000};
726 if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
727 &tv, sizeof(tv)) < 0)
728 syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)",
729 strerror(errno));
730
731 // Receive cycle
732 len = recvmsg(sock, &msg, 0);
733 if (len < 0)
734 continue;
735
736 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
737 ch = CMSG_NXTHDR(&msg, ch)) {
738 if (ch->cmsg_level == SOL_IPV6 &&
739 ch->cmsg_type == IPV6_PKTINFO) {
740 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
741 break;
742 }
743 }
744
745 if (pktinfo == NULL) {
746 len = -1;
747 continue;
748 }
749
750 if (!dhcpv6_response_is_valid(buf, len, trid,
751 type, &pktinfo->ipi6_addr)) {
752 len = -1;
753 continue;
754 }
755
756 uint8_t *opt = &buf[4];
757 uint8_t *opt_end = opt + len - 4;
758
759 round_start = odhcp6c_get_milli_time();
760 elapsed = round_start - start;
761 syslog(LOG_NOTICE, "Got a valid %s after %"PRIu64"ms",
762 dhcpv6_msg_to_str(hdr->msg_type), elapsed);
763
764 if (retx->handler_reply)
765 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
766
767 if (len > 0 && round_end - round_start > 1000)
768 round_end = 1000 + round_start;
769 }
770
771 // Allow
772 if (retx->handler_finish)
773 len = retx->handler_finish();
774 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
775 (!retx->max_rc || rc < retx->max_rc));
776 return len;
777 }
778
779 // Message validation checks according to RFC3315 chapter 15
780 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
781 const uint8_t transaction[3], enum dhcpv6_msg type,
782 const struct in6_addr *daddr)
783 {
784 const struct dhcpv6_header *rep = buf;
785 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
786 transaction, sizeof(rep->tr_id)))
787 return false; // Invalid reply
788
789 if (type == DHCPV6_MSG_SOLICIT) {
790 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
791 rep->msg_type != DHCPV6_MSG_REPLY)
792 return false;
793
794 } else if (type == DHCPV6_MSG_UNKNOWN) {
795 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
796 return false;
797
798 } else if (rep->msg_type != DHCPV6_MSG_REPLY)
799 return false;
800
801 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
802 rcmsg = DHCPV6_MSG_UNKNOWN;
803 uint16_t otype, olen = UINT16_MAX;
804 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
805 ia_present = false, options_valid = true;
806
807 size_t client_id_len, server_id_len;
808 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
809 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
810
811 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
812 if (otype == DHCPV6_OPT_CLIENTID) {
813 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
814 &odata[-4], client_id, client_id_len);
815 } else if (otype == DHCPV6_OPT_SERVERID) {
816 if (server_id_len)
817 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
818 &odata[-4], server_id, server_id_len);
819 else
820 serverid_ok = true;
821 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
822 sizeof(struct dhcpv6_auth_reconfigure)) {
823 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
824 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
825 continue;
826
827 md5_ctx_t md5;
828 uint8_t serverhash[16], secretbytes[64];
829 uint32_t hash[4];
830 memcpy(serverhash, r->key, sizeof(serverhash));
831 memset(r->key, 0, sizeof(r->key));
832
833 memset(secretbytes, 0, sizeof(secretbytes));
834 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
835
836 for (size_t i = 0; i < sizeof(secretbytes); ++i)
837 secretbytes[i] ^= 0x36;
838
839 md5_begin(&md5);
840 md5_hash(secretbytes, sizeof(secretbytes), &md5);
841 md5_hash(buf, len, &md5);
842 md5_end(hash, &md5);
843
844 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
845 secretbytes[i] ^= 0x36;
846 secretbytes[i] ^= 0x5c;
847 }
848
849 md5_begin(&md5);
850 md5_hash(secretbytes, sizeof(secretbytes), &md5);
851 md5_hash(hash, 16, &md5);
852 md5_end(hash, &md5);
853
854 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
855 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
856 rcmsg = odata[0];
857 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
858 ia_present = true;
859 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
860 options_valid = false;
861 } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
862 (otype == DHCPV6_OPT_PD_EXCLUDE))
863 // Options are not allowed on global level
864 options_valid = false;
865 }
866
867 if (!options_valid || ((odata + olen) > end))
868 return false;
869
870 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
871 return false;
872
873 if (rep->msg_type == DHCPV6_MSG_RECONF) {
874 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) ||
875 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
876 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
877 return false;
878 }
879
880 return clientid_ok && serverid_ok;
881 }
882
883 int dhcpv6_poll_reconfigure(void)
884 {
885 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
886
887 switch (ret) {
888 /*
889 * Only RENEW/REBIND/INFORMATION REQUEST
890 * message transmission can be requested
891 * by a RECONFIGURE
892 */
893 case DHCPV6_MSG_RENEW:
894 case DHCPV6_MSG_REBIND:
895 case DHCPV6_MSG_INFO_REQ:
896 ret = dhcpv6_request(ret);
897 break;
898
899 default:
900 break;
901 }
902
903 return ret;
904 }
905
906 static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc,
907 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
908 {
909 uint16_t otype, olen;
910 uint8_t *odata;
911 enum dhcpv6_msg msg = DHCPV6_MSG_UNKNOWN;
912
913 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
914 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
915 switch (odata[0]) {
916 case DHCPV6_MSG_REBIND:
917 if (t2 != UINT32_MAX)
918 t2 = 0;
919 // Fall through
920 case DHCPV6_MSG_RENEW:
921 if (t1 != UINT32_MAX)
922 t1 = 0;
923 // Fall through
924 case DHCPV6_MSG_INFO_REQ:
925 msg = odata[0];
926 syslog(LOG_NOTICE, "Need to respond with %s in reply to %s",
927 dhcpv6_msg_to_str(msg), dhcpv6_msg_to_str(DHCPV6_MSG_RECONF));
928 break;
929
930 default:
931 break;
932 }
933 }
934 }
935
936 if (msg != DHCPV6_MSG_UNKNOWN)
937 dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL);
938
939 return (msg == DHCPV6_MSG_UNKNOWN? -1: (int)msg);
940 }
941
942 // Collect all advertised servers
943 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
944 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
945 {
946 uint16_t olen, otype;
947 uint8_t *odata, pref = 0;
948 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
949 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
950 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
951 bool have_na = false;
952 int have_pd = 0;
953
954 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
955 if (orig == DHCPV6_MSG_SOLICIT &&
956 ((otype == DHCPV6_OPT_IA_PD && pd_mode != IA_MODE_NONE) ||
957 (otype == DHCPV6_OPT_IA_NA && na_mode != IA_MODE_NONE)) &&
958 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
959 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
960 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
961 }
962
963 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
964 memcpy(cand.duid, odata, olen);
965 cand.duid_len = olen;
966 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
967 cand.preference >= 0) {
968 cand.preference = pref = odata[0];
969 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
970 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
971 cand.server_addr = *(struct in6_addr *)odata;
972
973 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
974 cand.wants_reconfigure = true;
975 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
976 uint32_t sol_max_rt = ntohl_unaligned(odata);
977 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
978 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
979 cand.sol_max_rt = sol_max_rt;
980
981 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
982 uint32_t inf_max_rt = ntohl_unaligned(odata);
983 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
984 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
985 cand.inf_max_rt = inf_max_rt;
986
987 } else if (otype == DHCPV6_OPT_IA_PD &&
988 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
989 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
990 uint8_t *oend = odata + olen, *d;
991 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
992 if (otype == DHCPV6_OPT_IA_PREFIX &&
993 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
994 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
995 have_pd = p->prefix;
996 }
997 }
998 } else if (otype == DHCPV6_OPT_IA_NA &&
999 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
1000 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
1001 uint8_t *oend = odata + olen, *d;
1002
1003 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
1004 if (otype == DHCPV6_OPT_IA_ADDR &&
1005 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
1006 have_na = true;
1007 }
1008 }
1009 }
1010
1011 if ((!have_na && na_mode == IA_MODE_FORCE) ||
1012 (!have_pd && pd_mode == IA_MODE_FORCE)) {
1013 /*
1014 * RFC7083 states to process the SOL_MAX_RT and
1015 * INF_MAX_RT options even if the DHCPv6 server
1016 * did not propose any IA_NA and/or IA_PD
1017 */
1018 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
1019 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
1020 return -1;
1021 }
1022
1023 if (na_mode != IA_MODE_NONE && !have_na) {
1024 cand.has_noaddravail = true;
1025 cand.preference -= 1000;
1026 }
1027
1028 if (pd_mode != IA_MODE_NONE) {
1029 if (have_pd)
1030 cand.preference += 2000 + (128 - have_pd);
1031 else
1032 cand.preference -= 2000;
1033 }
1034
1035 if (cand.duid_len > 0) {
1036 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
1037 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
1038 dhcpv6_add_server_cand(&cand);
1039 }
1040
1041 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
1042 }
1043
1044 static int dhcpv6_commit_advert(void)
1045 {
1046 return dhcpv6_promote_server_cand();
1047 }
1048
1049 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
1050 const void *opt, const void *end, const struct sockaddr_in6 *from)
1051 {
1052 dhcpv6_handle_advert(orig, rc, opt, end, from);
1053 if (dhcpv6_commit_advert() < 0)
1054 return -1;
1055
1056 return dhcpv6_handle_reply(orig, rc, opt, end, from);
1057 }
1058
1059 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
1060 const void *opt, const void *end, const struct sockaddr_in6 *from)
1061 {
1062 uint8_t *odata;
1063 uint16_t otype, olen;
1064 uint32_t refresh = 86400;
1065 int ret = 1;
1066 unsigned int state_IAs;
1067 unsigned int updated_IAs = 0;
1068 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
1069
1070 odhcp6c_expire();
1071
1072 if (orig == DHCPV6_MSG_UNKNOWN) {
1073 static time_t last_update = 0;
1074 time_t now = odhcp6c_get_milli_time() / 1000;
1075
1076 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
1077 last_update = now;
1078
1079 if (t1 != UINT32_MAX)
1080 t1 -= elapsed;
1081
1082 if (t2 != UINT32_MAX)
1083 t2 -= elapsed;
1084
1085 if (t3 != UINT32_MAX)
1086 t3 -= elapsed;
1087
1088 if (t1 < 0)
1089 t1 = 0;
1090
1091 if (t2 < 0)
1092 t2 = 0;
1093
1094 if (t3 < 0)
1095 t3 = 0;
1096 }
1097
1098 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
1099 // Delete NA and PD we have in the state from the Advert
1100 odhcp6c_clear_state(STATE_IA_NA);
1101 odhcp6c_clear_state(STATE_IA_PD);
1102 }
1103
1104 if (opt) {
1105 odhcp6c_clear_state(STATE_DNS);
1106 odhcp6c_clear_state(STATE_SEARCH);
1107 odhcp6c_clear_state(STATE_SNTP_IP);
1108 odhcp6c_clear_state(STATE_NTP_IP);
1109 odhcp6c_clear_state(STATE_NTP_FQDN);
1110 odhcp6c_clear_state(STATE_SIP_IP);
1111 odhcp6c_clear_state(STATE_SIP_FQDN);
1112 odhcp6c_clear_state(STATE_AFTR_NAME);
1113 odhcp6c_clear_state(STATE_CER);
1114 odhcp6c_clear_state(STATE_S46_MAPT);
1115 odhcp6c_clear_state(STATE_S46_MAPE);
1116 odhcp6c_clear_state(STATE_S46_LW);
1117 odhcp6c_clear_state(STATE_PASSTHRU);
1118 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
1119
1120 // Parse and find all matching IAs
1121 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
1122 struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype);
1123
1124 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1125 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1126 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1127
1128 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1129 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1130 continue;
1131
1132 // Test ID
1133 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1134 continue;
1135
1136 uint16_t code = DHCPV6_Success;
1137 uint16_t stype, slen;
1138 uint8_t *sdata;
1139 // Get and handle status code
1140 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1141 stype, slen, sdata) {
1142 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1143 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1144 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1145
1146 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1147
1148 if (code == DHCPV6_Success)
1149 continue;
1150
1151 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1152 code, mdata, mlen, handled_status_codes, &ret);
1153
1154 if (ret > 0)
1155 return ret;
1156
1157 break;
1158 }
1159 }
1160
1161 if (code != DHCPV6_Success)
1162 continue;
1163
1164 updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen);
1165 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1166 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
1167 server_addr = *(struct in6_addr *)odata;
1168
1169 }
1170 else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1171 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1172 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1173 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1174
1175 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1176 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1177 if (olen % 16 == 0)
1178 odhcp6c_add_state(STATE_DNS, odata, olen);
1179 } else if (otype == DHCPV6_OPT_DNS_DOMAIN)
1180 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1181 else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1182 if (olen % 16 == 0)
1183 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1184 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1185 uint16_t stype, slen;
1186 uint8_t *sdata;
1187 // Test status and bail if error
1188 dhcpv6_for_each_option(odata, odata + olen,
1189 stype, slen, sdata) {
1190 if (slen == 16 && (stype == NTP_MC_ADDR ||
1191 stype == NTP_SRV_ADDR))
1192 odhcp6c_add_state(STATE_NTP_IP,
1193 sdata, slen);
1194 else if (slen > 0 && stype == NTP_SRV_FQDN)
1195 odhcp6c_add_state(STATE_NTP_FQDN,
1196 sdata, slen);
1197 }
1198 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1199 if (olen == 16)
1200 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1201 } else if (otype == DHCPV6_OPT_SIP_SERVER_D)
1202 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1203 else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1204 refresh = ntohl_unaligned(odata);
1205 } else if (otype == DHCPV6_OPT_AUTH) {
1206 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1207 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1208 if (r->protocol == 3 && r->algorithm == 1 &&
1209 r->reconf_type == 1)
1210 memcpy(reconf_key, r->key, sizeof(r->key));
1211 }
1212 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1213 size_t cur_len;
1214 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1215 if (cur_len == 0)
1216 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1217 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1218 uint32_t sol_max_rt = ntohl_unaligned(odata);
1219 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1220 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1221 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1222 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1223 uint32_t inf_max_rt = ntohl_unaligned(odata);
1224 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1225 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1226 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1227 #ifdef EXT_CER_ID
1228 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1229 sizeof(struct dhcpv6_cer_id)) {
1230 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1231 struct in6_addr any = IN6ADDR_ANY_INIT;
1232 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1233 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1234 #endif
1235 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1236 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1237 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1238 size_t mape_len;
1239 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1240 if (mape_len == 0)
1241 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1242 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1243 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1244 } else
1245 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1246
1247 if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU))
1248 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1249 }
1250 }
1251
1252 // Bail out if fatal status code was received
1253 if (ret <= 0)
1254 return ret;
1255
1256 switch (orig) {
1257 case DHCPV6_MSG_REQUEST:
1258 case DHCPV6_MSG_REBIND:
1259 case DHCPV6_MSG_RENEW:
1260 state_IAs = dhcpv6_calc_refresh_timers();
1261 // In case there're no state IA entries
1262 // keep sending request/renew/rebind messages
1263 if (state_IAs == 0) {
1264 ret = 0;
1265 break;
1266 }
1267
1268 if (orig == DHCPV6_MSG_REQUEST) {
1269 // All server candidates can be cleared if not yet bound
1270 if (!odhcp6c_is_bound())
1271 dhcpv6_clear_all_server_cand();
1272
1273 odhcp6c_clear_state(STATE_SERVER_ADDR);
1274 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1275 } else if (orig == DHCPV6_MSG_RENEW) {
1276 // Send further renews if T1 is not set and if
1277 // there're IAs which were not in the Reply message
1278 if (!t1 && state_IAs != updated_IAs) {
1279 if (updated_IAs)
1280 // Publish updates
1281 script_call("updated", 0, false);
1282
1283 /*
1284 * RFC8415 states following in §18.2.10.1 :
1285 * Sends a Renew/Rebind if any of the IAs are not in the Reply
1286 * message, but as this likely indicates that the server that
1287 * responded does not support that IA type, sending immediately is
1288 * unlikely to produce a different result. Therefore, the client
1289 * MUST rate-limit its transmissions (see Section 14.1) and MAY just
1290 * wait for the normal retransmission time (as if the Reply message
1291 * had not been received). The client continues to use other
1292 * bindings for which the server did return information
1293 */
1294 ret = -1;
1295 }
1296 } else if (orig == DHCPV6_MSG_REBIND) {
1297 odhcp6c_clear_state(STATE_SERVER_ADDR);
1298 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1299
1300 // Send further rebinds if T1 and T2 is not set and if
1301 // there're IAs which were not in the Reply message
1302 if (!t1 && !t2 && state_IAs != updated_IAs) {
1303 if (updated_IAs)
1304 // Publish updates
1305 script_call("updated", 0, false);
1306
1307 /*
1308 * RFC8415 states following in §18.2.10.1 :
1309 * Sends a Renew/Rebind if any of the IAs are not in the Reply
1310 * message, but as this likely indicates that the server that
1311 * responded does not support that IA type, sending immediately is
1312 * unlikely to produce a different result. Therefore, the client
1313 * MUST rate-limit its transmissions (see Section 14.1) and MAY just
1314 * wait for the normal retransmission time (as if the Reply message
1315 * had not been received). The client continues to use other
1316 * bindings for which the server did return information
1317 */
1318 ret = -1;
1319 }
1320 }
1321 break;
1322
1323 case DHCPV6_MSG_INFO_REQ:
1324 // All server candidates can be cleared if not yet bound
1325 if (!odhcp6c_is_bound())
1326 dhcpv6_clear_all_server_cand();
1327
1328 t1 = refresh;
1329 break;
1330
1331 default:
1332 break;
1333 }
1334
1335 return ret;
1336 }
1337
1338 static unsigned int dhcpv6_parse_ia(void *opt, void *end)
1339 {
1340 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1341 unsigned int updated_IAs = 0;
1342 uint32_t t1, t2;
1343 uint16_t otype, olen;
1344 uint8_t *odata;
1345 char buf[INET6_ADDRSTRLEN];
1346
1347 t1 = ntohl(ia_hdr->t1);
1348 t2 = ntohl(ia_hdr->t2);
1349
1350 if (t1 > t2)
1351 return 0;
1352
1353 syslog(LOG_INFO, "%s %04x T1 %d T2 %d", ntohs(ia_hdr->type) == DHCPV6_OPT_IA_PD ? "IA_PD" : "IA_NA", ntohl(ia_hdr->iaid), t1, t2);
1354
1355 // Update address IA
1356 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1357 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1358 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1359
1360 entry.iaid = ia_hdr->iaid;
1361
1362 if (otype == DHCPV6_OPT_IA_PREFIX) {
1363 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1364 if (olen + 4U < sizeof(*prefix))
1365 continue;
1366
1367 entry.valid = ntohl(prefix->valid);
1368 entry.preferred = ntohl(prefix->preferred);
1369
1370 if (entry.preferred > entry.valid)
1371 continue;
1372
1373 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1374 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1375 if (entry.t1 > entry.t2)
1376 entry.t1 = entry.t2;
1377
1378 entry.length = prefix->prefix;
1379 entry.target = prefix->addr;
1380 uint16_t stype, slen;
1381 uint8_t *sdata;
1382
1383 // Parse PD-exclude
1384 bool ok = true;
1385 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1386 odata + olen, stype, slen, sdata) {
1387 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1388 continue;
1389
1390 uint8_t elen = sdata[0];
1391 if (elen > 64)
1392 elen = 64;
1393
1394 if (entry.length < 32 || elen <= entry.length) {
1395 ok = false;
1396 continue;
1397 }
1398
1399 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1400 if (slen <= bytes) {
1401 ok = false;
1402 continue;
1403 }
1404
1405 uint32_t exclude = 0;
1406 do {
1407 exclude = exclude << 8 | sdata[bytes];
1408 } while (--bytes);
1409
1410 exclude >>= 8 - ((elen - entry.length) % 8);
1411 exclude <<= 64 - elen;
1412
1413 // Abusing router & priority fields for exclusion
1414 entry.router = entry.target;
1415 entry.router.s6_addr32[1] |= htonl(exclude);
1416 entry.priority = elen;
1417 }
1418
1419 if (ok) {
1420 if (odhcp6c_update_entry(STATE_IA_PD, &entry, pd_safe_valid, 0))
1421 updated_IAs++;
1422
1423 syslog(LOG_INFO, "%s/%d preferred %d valid %d",
1424 inet_ntop(AF_INET6, &entry.target, buf, sizeof(buf)),
1425 entry.length, entry.preferred , entry.valid);
1426 }
1427
1428 entry.priority = 0;
1429 memset(&entry.router, 0, sizeof(entry.router));
1430 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1431 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1432 if (olen + 4U < sizeof(*addr))
1433 continue;
1434
1435 entry.preferred = ntohl(addr->preferred);
1436 entry.valid = ntohl(addr->valid);
1437
1438 if (entry.preferred > entry.valid)
1439 continue;
1440
1441 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1442 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1443 if (entry.t1 > entry.t2)
1444 entry.t1 = entry.t2;
1445
1446 entry.length = 128;
1447 entry.target = addr->addr;
1448
1449 if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0))
1450 updated_IAs++;
1451
1452 syslog(LOG_INFO, "%s preferred %d valid %d",
1453 inet_ntop(AF_INET6, &entry.target, buf, sizeof(buf)),
1454 entry.preferred , entry.valid);
1455 }
1456 }
1457
1458 return updated_IAs;
1459 }
1460
1461 static unsigned int dhcpv6_calc_refresh_timers(void)
1462 {
1463 struct odhcp6c_entry *e;
1464 size_t ia_na_entries, ia_pd_entries, i;
1465 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1466
1467 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1468 ia_na_entries /= sizeof(*e);
1469
1470 for (i = 0; i < ia_na_entries; i++) {
1471 if (e[i].t1 < l_t1)
1472 l_t1 = e[i].t1;
1473
1474 if (e[i].t2 < l_t2)
1475 l_t2 = e[i].t2;
1476
1477 if (e[i].valid > l_t3)
1478 l_t3 = e[i].valid;
1479 }
1480
1481 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1482 ia_pd_entries /= sizeof(*e);
1483
1484 for (i = 0; i < ia_pd_entries; i++) {
1485 if (e[i].t1 < l_t1)
1486 l_t1 = e[i].t1;
1487
1488 if (e[i].t2 < l_t2)
1489 l_t2 = e[i].t2;
1490
1491 if (e[i].valid > l_t3)
1492 l_t3 = e[i].valid;
1493 }
1494
1495 if (ia_pd_entries || ia_na_entries) {
1496 t1 = l_t1;
1497 t2 = l_t2;
1498 t3 = l_t3;
1499
1500 syslog(LOG_INFO, "T1 %"PRId64"s, T2 %"PRId64"s, T3 %"PRId64"s", t1, t2, t3);
1501 }
1502
1503 return (unsigned int)(ia_pd_entries + ia_na_entries);
1504 }
1505
1506 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1507 const void *status_msg, int len)
1508 {
1509 const char *src = status_msg;
1510 char buf[len + 3];
1511 char *dst = buf;
1512
1513 if (len) {
1514 *dst++ = '(';
1515 while (len--) {
1516 *dst = isprint((unsigned char)*src) ? *src : '?';
1517 src++;
1518 dst++;
1519 }
1520 *dst++ = ')';
1521 }
1522
1523 *dst = 0;
1524
1525 syslog(LOG_WARNING, "Server returned %s status '%s %s'",
1526 scope, dhcpv6_status_code_to_str(code), buf);
1527 }
1528
1529 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1530 const uint16_t code, const void *status_msg, const int len,
1531 int *ret)
1532 {
1533 dhcpv6_log_status_code(code, "message", status_msg, len);
1534
1535 switch (code) {
1536 case DHCPV6_UnspecFail:
1537 // Generic failure
1538 *ret = 0;
1539 break;
1540
1541 case DHCPV6_UseMulticast:
1542 switch(orig) {
1543 case DHCPV6_MSG_REQUEST:
1544 case DHCPV6_MSG_RENEW:
1545 case DHCPV6_MSG_RELEASE:
1546 case DHCPV6_MSG_DECLINE:
1547 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1548 server_addr = in6addr_any;
1549 *ret = 0;
1550 break;
1551 default:
1552 break;
1553 }
1554 break;
1555
1556 case DHCPV6_NoAddrsAvail:
1557 case DHCPV6_NoPrefixAvail:
1558 if (orig == DHCPV6_MSG_REQUEST)
1559 *ret = 0; // Failure
1560 break;
1561
1562 default:
1563 break;
1564 }
1565 }
1566
1567 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1568 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1569 const void *status_msg, const int len,
1570 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1571 {
1572 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1573 "IA_NA" : "IA_PD", status_msg, len);
1574
1575 switch (code) {
1576 case DHCPV6_NoBinding:
1577 switch (orig) {
1578 case DHCPV6_MSG_RENEW:
1579 case DHCPV6_MSG_REBIND:
1580 if ((*ret > 0) && !handled_status_codes[code])
1581 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1582 break;
1583
1584 default:
1585 break;
1586 }
1587 break;
1588
1589 default:
1590 *ret = 0;
1591 break;
1592 }
1593 }
1594
1595 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1596 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1597 {
1598 size_t cand_len, i;
1599 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1600
1601 // Remove identical duid server candidate
1602 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1603 if (cand->duid_len == c[i].duid_len &&
1604 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1605 free(c[i].ia_na);
1606 free(c[i].ia_pd);
1607 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1608 break;
1609 }
1610 }
1611
1612 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1613 i < cand_len / sizeof(*c); ++i) {
1614 if (c[i].preference < cand->preference)
1615 break;
1616 }
1617
1618 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1619 free(cand->ia_na);
1620 free(cand->ia_pd);
1621 }
1622 }
1623
1624 static void dhcpv6_clear_all_server_cand(void)
1625 {
1626 size_t cand_len, i;
1627 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1628
1629 // Server candidates need deep delete for IA_NA/IA_PD
1630 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1631 free(c[i].ia_na);
1632 free(c[i].ia_pd);
1633 }
1634 odhcp6c_clear_state(STATE_SERVER_CAND);
1635 }
1636
1637 int dhcpv6_promote_server_cand(void)
1638 {
1639 size_t cand_len;
1640 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1641 uint16_t hdr[2];
1642 int ret = DHCPV6_STATELESS;
1643
1644 // Clear lingering candidate state info
1645 odhcp6c_clear_state(STATE_SERVER_ID);
1646 odhcp6c_clear_state(STATE_IA_NA);
1647 odhcp6c_clear_state(STATE_IA_PD);
1648
1649 if (!cand_len)
1650 return -1;
1651
1652 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1653 na_mode = IA_MODE_NONE;
1654
1655 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1656 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1657
1658 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1659 }
1660
1661 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1662 hdr[1] = htons(cand->duid_len);
1663 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1664 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1665 accept_reconfig = cand->wants_reconfigure;
1666
1667 if (cand->ia_na_len) {
1668 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1669 free(cand->ia_na);
1670 if (na_mode != IA_MODE_NONE)
1671 ret = DHCPV6_STATEFUL;
1672 }
1673
1674 if (cand->ia_pd_len) {
1675 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1676 free(cand->ia_pd);
1677 if (pd_mode != IA_MODE_NONE)
1678 ret = DHCPV6_STATEFUL;
1679 }
1680
1681 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1682 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1683
1684 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1685
1686 return ret;
1687 }
Openwrt DHCPv6 Client