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[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 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 static uint32_t ntohl_unaligned(const uint8_t *data)
118 {
119 uint32_t buf;
120
121 memcpy(&buf, data, sizeof(buf));
122 return ntohl(buf);
123 }
124
125 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
126 {
127 client_options = options;
128 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
129
130 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
131 if (sock < 0)
132 goto failure;
133
134 // Detect interface
135 struct ifreq ifr;
136 memset(&ifr, 0, sizeof(ifr));
137 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
138 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
139 goto failure;
140
141 ifindex = ifr.ifr_ifindex;
142
143 // Create client DUID
144 size_t client_id_len;
145 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
146 if (client_id_len == 0) {
147 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
148 DHCPV6_DUID_LLADDR, 0, 1};
149
150 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
151 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
152
153 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
154 struct ifreq ifs[100], *ifp, *ifend;
155 struct ifconf ifc;
156 ifc.ifc_req = ifs;
157 ifc.ifc_len = sizeof(ifs);
158
159 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
160 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
161 // If our interface doesn't have an address...
162 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
163 for (ifp = ifc.ifc_req; ifp < ifend &&
164 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
165 memcpy(ifr.ifr_name, ifp->ifr_name,
166 sizeof(ifr.ifr_name));
167 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
168 continue;
169
170 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
171 ETHER_ADDR_LEN);
172 }
173 }
174
175 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
176 }
177
178 // Create ORO
179 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
180 uint16_t oro[] = {
181 htons(DHCPV6_OPT_SIP_SERVER_D),
182 htons(DHCPV6_OPT_SIP_SERVER_A),
183 htons(DHCPV6_OPT_DNS_SERVERS),
184 htons(DHCPV6_OPT_DNS_DOMAIN),
185 htons(DHCPV6_OPT_SNTP_SERVERS),
186 htons(DHCPV6_OPT_NTP_SERVER),
187 htons(DHCPV6_OPT_AFTR_NAME),
188 htons(DHCPV6_OPT_PD_EXCLUDE),
189 #ifdef EXT_CER_ID
190 htons(DHCPV6_OPT_CER_ID),
191 #endif
192 htons(DHCPV6_OPT_S46_CONT_MAPE),
193 htons(DHCPV6_OPT_S46_CONT_MAPT),
194 htons(DHCPV6_OPT_S46_CONT_LW),
195 };
196 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
197 }
198 // Required oro
199 uint16_t req_oro[] = {
200 htons(DHCPV6_OPT_INF_MAX_RT),
201 htons(DHCPV6_OPT_SOL_MAX_RT),
202 htons(DHCPV6_OPT_INFO_REFRESH),
203 };
204 odhcp6c_add_state(STATE_ORO, req_oro, sizeof(req_oro));
205
206 // Configure IPv6-options
207 int val = 1;
208 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
209 goto failure;
210
211 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
212 goto failure;
213
214 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
215 goto failure;
216
217 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
218 goto failure;
219
220 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
221 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
222
223 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
224 goto failure;
225
226 return 0;
227
228 failure:
229 if (sock >= 0)
230 close(sock);
231
232 return -1;
233 }
234
235 enum {
236 IOV_HDR=0,
237 IOV_ORO,
238 IOV_CL_ID,
239 IOV_SRV_ID,
240 IOV_OPTS,
241 IOV_RECONF_ACCEPT,
242 IOV_FQDN,
243 IOV_HDR_IA_NA,
244 IOV_IA_NA,
245 IOV_IA_PD,
246 IOV_TOTAL
247 };
248
249 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
250 {
251 int mode = DHCPV6_UNKNOWN;
252
253 na_mode = na;
254 pd_mode = pd;
255
256 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
257 mode = DHCPV6_STATELESS;
258 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
259 mode = DHCPV6_STATEFUL;
260
261 return mode;
262 }
263
264 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
265 {
266 // Build FQDN
267 char fqdn_buf[256];
268 gethostname(fqdn_buf, sizeof(fqdn_buf));
269 struct {
270 uint16_t type;
271 uint16_t len;
272 uint8_t flags;
273 uint8_t data[256];
274 } fqdn;
275 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
276 sizeof(fqdn.data), NULL, NULL);
277 fqdn.type = htons(DHCPV6_OPT_FQDN);
278 fqdn.len = htons(fqdn_len - 4);
279 fqdn.flags = 0;
280
281 // Build Client ID
282 size_t cl_id_len;
283 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
284
285 // Get Server ID
286 size_t srv_id_len;
287 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
288
289 // Build IA_PDs
290 size_t ia_pd_entries = 0, ia_pd_len = 0;
291 uint8_t *ia_pd;
292
293 if (type == DHCPV6_MSG_SOLICIT) {
294 odhcp6c_clear_state(STATE_IA_PD);
295 size_t n_prefixes;
296 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
297 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
298
299 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
300
301 for (size_t i = 0; i < n_prefixes; i++) {
302 struct dhcpv6_ia_hdr hdr_ia_pd = {
303 htons(DHCPV6_OPT_IA_PD),
304 htons(sizeof(hdr_ia_pd) - 4 +
305 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
306 request_prefixes[i].iaid, 0, 0
307 };
308 struct dhcpv6_ia_prefix pref = {
309 .type = htons(DHCPV6_OPT_IA_PREFIX),
310 .len = htons(sizeof(pref) - 4),
311 .prefix = request_prefixes[i].length
312 };
313 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
314 ia_pd_len += sizeof(hdr_ia_pd);
315 if (request_prefixes[i].length) {
316 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
317 ia_pd_len += sizeof(pref);
318 }
319 }
320 } else {
321 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
322 ia_pd_entries /= sizeof(*e);
323
324 // we're too lazy to count our distinct IAIDs,
325 // so just allocate maximally needed space
326 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
327 sizeof(struct dhcpv6_ia_hdr)));
328
329 for (size_t i = 0; i < ia_pd_entries; ++i) {
330 uint32_t iaid = e[i].iaid;
331
332 // check if this is an unprocessed IAID and skip if not.
333 int new_iaid = 1;
334 for (int j = i-1; j >= 0; j--) {
335 if (e[j].iaid == iaid) {
336 new_iaid = 0;
337 break;
338 }
339 }
340
341 if (!new_iaid)
342 continue;
343
344 // construct header
345 struct dhcpv6_ia_hdr hdr_ia_pd = {
346 htons(DHCPV6_OPT_IA_PD),
347 htons(sizeof(hdr_ia_pd) - 4),
348 iaid, 0, 0
349 };
350
351 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
352 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
353 ia_pd_len += sizeof(hdr_ia_pd);
354
355 for (size_t j = i; j < ia_pd_entries; j++) {
356 if (e[j].iaid != iaid)
357 continue;
358
359 uint8_t ex_len = 0;
360 if (e[j].priority > 0)
361 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
362
363 struct dhcpv6_ia_prefix p = {
364 .type = htons(DHCPV6_OPT_IA_PREFIX),
365 .len = htons(sizeof(p) - 4U + ex_len),
366 .prefix = e[j].length,
367 .addr = e[j].target
368 };
369
370 if (type == DHCPV6_MSG_REQUEST) {
371 p.preferred = htonl(e[j].preferred);
372 p.valid = htonl(e[j].valid);
373 }
374
375 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
376 ia_pd_len += sizeof(p);
377
378 if (ex_len) {
379 ia_pd[ia_pd_len++] = 0;
380 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
381 ia_pd[ia_pd_len++] = 0;
382 ia_pd[ia_pd_len++] = ex_len - 4;
383 ia_pd[ia_pd_len++] = e[j].priority;
384
385 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
386 excl >>= (64 - e[j].priority);
387 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
388
389 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
390 ia_pd[ia_pd_len + i] = excl & 0xff;
391 ia_pd_len += ex_len - 5;
392 }
393
394 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
395 }
396 }
397 }
398
399 // Build IA_NAs
400 size_t ia_na_entries, ia_na_len = 0;
401 void *ia_na = NULL;
402 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
403 ia_na_entries /= sizeof(*e);
404
405 struct dhcpv6_ia_hdr hdr_ia_na = {
406 htons(DHCPV6_OPT_IA_NA),
407 htons(sizeof(hdr_ia_na) - 4),
408 htonl(1), 0, 0
409 };
410
411 struct dhcpv6_ia_addr pa[ia_na_entries];
412 for (size_t i = 0; i < ia_na_entries; ++i) {
413 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
414 pa[i].len = htons(sizeof(pa[i]) - 4U);
415 pa[i].addr = e[i].target;
416
417 if (type == DHCPV6_MSG_REQUEST) {
418 pa[i].preferred = htonl(e[i].preferred);
419 pa[i].valid = htonl(e[i].valid);
420 } else {
421 pa[i].preferred = 0;
422 pa[i].valid = 0;
423 }
424 }
425
426 ia_na = pa;
427 ia_na_len = sizeof(pa);
428 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
429
430 // Reconfigure Accept
431 struct {
432 uint16_t type;
433 uint16_t length;
434 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
435
436 // Option list
437 size_t opts_len;
438 void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len);
439
440 // Option Request List
441 size_t oro_entries, oro_len = 0;
442 uint16_t *oro, *s_oro = odhcp6c_get_state(STATE_ORO, &oro_entries);
443
444 oro_entries /= sizeof(*s_oro);
445 oro = alloca(oro_entries * sizeof(*oro));
446
447 for (size_t i = 0; i < oro_entries; i++) {
448 struct odhcp6c_opt *opt = odhcp6c_find_opt(htons(s_oro[i]));
449
450 if (opt) {
451 if (!(opt->flags & OPT_ORO))
452 continue;
453
454 if ((opt->flags & OPT_ORO_SOLICIT) && type != DHCPV6_MSG_SOLICIT)
455 continue;
456
457 if ((opt->flags & OPT_ORO_STATELESS) && type != DHCPV6_MSG_INFO_REQ)
458 continue;
459
460 if ((opt->flags & OPT_ORO_STATEFUL) && type == DHCPV6_MSG_INFO_REQ)
461 continue;
462 }
463
464 oro[oro_len++] = s_oro[i];
465 }
466 oro_len *= sizeof(*oro);
467
468 // Prepare Header
469 struct {
470 uint8_t type;
471 uint8_t trid[3];
472 uint16_t elapsed_type;
473 uint16_t elapsed_len;
474 uint16_t elapsed_value;
475 uint16_t oro_type;
476 uint16_t oro_len;
477 } hdr = {
478 type, {trid[0], trid[1], trid[2]},
479 htons(DHCPV6_OPT_ELAPSED), htons(2),
480 htons((ecs > 0xffff) ? 0xffff : ecs),
481 htons(DHCPV6_OPT_ORO), htons(oro_len),
482 };
483
484 struct iovec iov[IOV_TOTAL] = {
485 [IOV_HDR] = {&hdr, sizeof(hdr)},
486 [IOV_ORO] = {oro, oro_len},
487 [IOV_CL_ID] = {cl_id, cl_id_len},
488 [IOV_SRV_ID] = {srv_id, srv_id_len},
489 [IOV_OPTS] = { opts, opts_len },
490 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
491 [IOV_FQDN] = {&fqdn, fqdn_len},
492 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
493 [IOV_IA_NA] = {ia_na, ia_na_len},
494 [IOV_IA_PD] = {ia_pd, ia_pd_len},
495 };
496
497 size_t cnt = IOV_TOTAL;
498 if (type == DHCPV6_MSG_INFO_REQ)
499 cnt = IOV_HDR_IA_NA;
500
501 // Disable IAs if not used
502 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
503 iov[IOV_HDR_IA_NA].iov_len = 0;
504
505 if (na_mode == IA_MODE_NONE)
506 iov[IOV_HDR_IA_NA].iov_len = 0;
507
508 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
509 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
510 iov[IOV_RECONF_ACCEPT].iov_len = 0;
511
512 if (!(client_options & DHCPV6_CLIENT_FQDN))
513 iov[IOV_FQDN].iov_len = 0;
514
515 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
516 0, ALL_DHCPV6_RELAYS, ifindex};
517 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
518 .msg_iov = iov, .msg_iovlen = cnt};
519
520 switch (type) {
521 case DHCPV6_MSG_REQUEST:
522 case DHCPV6_MSG_RENEW:
523 case DHCPV6_MSG_RELEASE:
524 case DHCPV6_MSG_DECLINE:
525 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
526 odhcp6c_addr_in_scope(&server_addr)) {
527 srv.sin6_addr = server_addr;
528 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
529 srv.sin6_scope_id = 0;
530 }
531 break;
532 default:
533 break;
534 }
535
536 if (sendmsg(sock, &msg, 0) < 0) {
537 char in6_str[INET6_ADDRSTRLEN];
538
539 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
540 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
541 in6_str, sizeof(in6_str)), strerror(errno));
542 }
543 }
544
545 static int64_t dhcpv6_rand_delay(int64_t time)
546 {
547 int random;
548 odhcp6c_random(&random, sizeof(random));
549
550 return (time * ((int64_t)random % 1000LL)) / 10000LL;
551 }
552
553 int dhcpv6_request(enum dhcpv6_msg type)
554 {
555 uint8_t rc = 0;
556 uint64_t timeout = UINT32_MAX;
557 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
558
559 if (retx->delay) {
560 struct timespec ts = {0, 0};
561 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
562
563 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
564 }
565
566 if (type == DHCPV6_MSG_UNKNOWN)
567 timeout = t1;
568 else if (type == DHCPV6_MSG_RENEW)
569 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
570 else if (type == DHCPV6_MSG_REBIND)
571 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
572
573 if (timeout == 0)
574 return -1;
575
576 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
577 retx->name, timeout, retx->max_rc);
578
579 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
580
581 // Generate transaction ID
582 uint8_t trid[3] = {0, 0, 0};
583 if (type != DHCPV6_MSG_UNKNOWN)
584 odhcp6c_random(trid, sizeof(trid));
585
586 ssize_t len = -1;
587 int64_t rto = 0;
588
589 do {
590 if (rto == 0) {
591 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
592
593 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
594 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
595 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
596
597 rto = (retx->init_timeo * 1000 + delay);
598 } else
599 rto = (2 * rto + dhcpv6_rand_delay(rto));
600
601 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
602 rto = retx->max_timeo * 1000 +
603 dhcpv6_rand_delay(retx->max_timeo * 1000);
604
605 // Calculate end for this round and elapsed time
606 uint64_t round_end = round_start + rto;
607 elapsed = round_start - start;
608
609 // Don't wait too long if timeout differs from infinite
610 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
611 round_end = timeout * 1000 + start;
612
613 // Built and send package
614 switch (type) {
615 case DHCPV6_MSG_UNKNOWN:
616 break;
617 default:
618 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
619 retx->name, elapsed, rc);
620 // Fall through
621 case DHCPV6_MSG_SOLICIT:
622 case DHCPV6_MSG_INFO_REQ:
623 dhcpv6_send(type, trid, elapsed / 10);
624 rc++;
625 }
626
627 // Receive rounds
628 for (; len < 0 && (round_start < round_end);
629 round_start = odhcp6c_get_milli_time()) {
630 uint8_t buf[1536];
631 union {
632 struct cmsghdr hdr;
633 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
634 } cmsg_buf;
635 struct iovec iov = {buf, sizeof(buf)};
636 struct sockaddr_in6 addr;
637 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
638 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
639 .msg_controllen = sizeof(cmsg_buf)};
640 struct in6_pktinfo *pktinfo = NULL;
641
642 // Check for pending signal
643 if (odhcp6c_signal_process())
644 return -1;
645
646 // Set timeout for receiving
647 uint64_t t = round_end - round_start;
648 struct timeval tv = {t / 1000, (t % 1000) * 1000};
649 if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
650 &tv, sizeof(tv)) < 0)
651 syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)",
652 strerror(errno));
653
654 // Receive cycle
655 len = recvmsg(sock, &msg, 0);
656 if (len < 0)
657 continue;
658
659 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
660 ch = CMSG_NXTHDR(&msg, ch)) {
661 if (ch->cmsg_level == SOL_IPV6 &&
662 ch->cmsg_type == IPV6_PKTINFO) {
663 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
664 break;
665 }
666 }
667
668 if (pktinfo == NULL) {
669 len = -1;
670 continue;
671 }
672
673 if (!dhcpv6_response_is_valid(buf, len, trid,
674 type, &pktinfo->ipi6_addr)) {
675 len = -1;
676 continue;
677 }
678
679 uint8_t *opt = &buf[4];
680 uint8_t *opt_end = opt + len - 4;
681
682 round_start = odhcp6c_get_milli_time();
683 elapsed = round_start - start;
684 syslog(LOG_NOTICE, "Got a valid reply after %"PRIu64"ms",
685 elapsed);
686
687 if (retx->handler_reply)
688 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
689
690 if (len > 0 && round_end - round_start > 1000)
691 round_end = 1000 + round_start;
692 }
693
694 // Allow
695 if (retx->handler_finish)
696 len = retx->handler_finish();
697 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
698 (!retx->max_rc || rc < retx->max_rc));
699 return len;
700 }
701
702 // Message validation checks according to RFC3315 chapter 15
703 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
704 const uint8_t transaction[3], enum dhcpv6_msg type,
705 const struct in6_addr *daddr)
706 {
707 const struct dhcpv6_header *rep = buf;
708 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
709 transaction, sizeof(rep->tr_id)))
710 return false; // Invalid reply
711
712 if (type == DHCPV6_MSG_SOLICIT) {
713 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
714 rep->msg_type != DHCPV6_MSG_REPLY)
715 return false;
716
717 } else if (type == DHCPV6_MSG_UNKNOWN) {
718 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
719 return false;
720
721 } else if (rep->msg_type != DHCPV6_MSG_REPLY)
722 return false;
723
724 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
725 rcmsg = DHCPV6_MSG_UNKNOWN;
726 uint16_t otype, olen = UINT16_MAX;
727 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
728 ia_present = false, options_valid = true;
729
730 size_t client_id_len, server_id_len;
731 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
732 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
733
734 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
735 if (otype == DHCPV6_OPT_CLIENTID) {
736 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
737 &odata[-4], client_id, client_id_len);
738 } else if (otype == DHCPV6_OPT_SERVERID) {
739 if (server_id_len)
740 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
741 &odata[-4], server_id, server_id_len);
742 else
743 serverid_ok = true;
744 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
745 sizeof(struct dhcpv6_auth_reconfigure)) {
746 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
747 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
748 continue;
749
750 md5_ctx_t md5;
751 uint8_t serverhash[16], secretbytes[64];
752 uint32_t hash[4];
753 memcpy(serverhash, r->key, sizeof(serverhash));
754 memset(r->key, 0, sizeof(r->key));
755
756 memset(secretbytes, 0, sizeof(secretbytes));
757 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
758
759 for (size_t i = 0; i < sizeof(secretbytes); ++i)
760 secretbytes[i] ^= 0x36;
761
762 md5_begin(&md5);
763 md5_hash(secretbytes, sizeof(secretbytes), &md5);
764 md5_hash(buf, len, &md5);
765 md5_end(hash, &md5);
766
767 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
768 secretbytes[i] ^= 0x36;
769 secretbytes[i] ^= 0x5c;
770 }
771
772 md5_begin(&md5);
773 md5_hash(secretbytes, sizeof(secretbytes), &md5);
774 md5_hash(hash, 16, &md5);
775 md5_end(hash, &md5);
776
777 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
778 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
779 rcmsg = odata[0];
780 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
781 ia_present = true;
782 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
783 options_valid = false;
784 } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
785 (otype == DHCPV6_OPT_PD_EXCLUDE))
786 // Options are not allowed on global level
787 options_valid = false;
788 }
789
790 if (!options_valid || ((odata + olen) > end))
791 return false;
792
793 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
794 return false;
795
796 if (rep->msg_type == DHCPV6_MSG_RECONF) {
797 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) ||
798 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
799 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
800 return false;
801 }
802
803 return clientid_ok && serverid_ok;
804 }
805
806 int dhcpv6_poll_reconfigure(void)
807 {
808 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
809
810 if (ret != -1)
811 ret = dhcpv6_request(ret);
812
813 return ret;
814 }
815
816 static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc,
817 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
818 {
819 uint16_t otype, olen;
820 uint8_t *odata;
821 int msg = -1;
822
823 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
824 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
825 switch (odata[0]) {
826 case DHCPV6_MSG_REBIND:
827 if (t2 != UINT32_MAX)
828 t2 = 0;
829 // Fall through
830 case DHCPV6_MSG_RENEW:
831 if (t1 != UINT32_MAX)
832 t1 = 0;
833 // Fall through
834 case DHCPV6_MSG_INFO_REQ:
835 msg = odata[0];
836 break;
837
838 default:
839 break;
840 }
841 }
842 }
843
844 dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL);
845
846 return msg;
847 }
848
849 // Collect all advertised servers
850 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
851 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
852 {
853 uint16_t olen, otype;
854 uint8_t *odata, pref = 0;
855 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
856 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
857 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
858 bool have_na = false;
859 int have_pd = 0;
860
861 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
862 if (orig == DHCPV6_MSG_SOLICIT &&
863 ((otype == DHCPV6_OPT_IA_PD && pd_mode != IA_MODE_NONE) ||
864 (otype == DHCPV6_OPT_IA_NA && na_mode != IA_MODE_NONE)) &&
865 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
866 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
867 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
868 }
869
870 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
871 memcpy(cand.duid, odata, olen);
872 cand.duid_len = olen;
873 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
874 cand.preference >= 0) {
875 cand.preference = pref = odata[0];
876 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
877 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
878 cand.server_addr = *(struct in6_addr *)odata;
879
880 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
881 cand.wants_reconfigure = true;
882 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
883 uint32_t sol_max_rt = ntohl_unaligned(odata);
884 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
885 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
886 cand.sol_max_rt = sol_max_rt;
887
888 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
889 uint32_t inf_max_rt = ntohl_unaligned(odata);
890 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
891 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
892 cand.inf_max_rt = inf_max_rt;
893
894 } else if (otype == DHCPV6_OPT_IA_PD &&
895 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
896 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
897 uint8_t *oend = odata + olen, *d;
898 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
899 if (otype == DHCPV6_OPT_IA_PREFIX &&
900 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
901 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
902 have_pd = p->prefix;
903 }
904 }
905 } else if (otype == DHCPV6_OPT_IA_NA &&
906 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
907 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
908 uint8_t *oend = odata + olen, *d;
909
910 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
911 if (otype == DHCPV6_OPT_IA_ADDR &&
912 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
913 have_na = true;
914 }
915 }
916 }
917
918 if ((!have_na && na_mode == IA_MODE_FORCE) ||
919 (!have_pd && pd_mode == IA_MODE_FORCE)) {
920 /*
921 * RFC7083 states to process the SOL_MAX_RT and
922 * INF_MAX_RT options even if the DHCPv6 server
923 * did not propose any IA_NA and/or IA_PD
924 */
925 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
926 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
927 return -1;
928 }
929
930 if (na_mode != IA_MODE_NONE && !have_na) {
931 cand.has_noaddravail = true;
932 cand.preference -= 1000;
933 }
934
935 if (pd_mode != IA_MODE_NONE) {
936 if (have_pd)
937 cand.preference += 2000 + (128 - have_pd);
938 else
939 cand.preference -= 2000;
940 }
941
942 if (cand.duid_len > 0) {
943 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
944 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
945 dhcpv6_add_server_cand(&cand);
946 }
947
948 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
949 }
950
951 static int dhcpv6_commit_advert(void)
952 {
953 return dhcpv6_promote_server_cand();
954 }
955
956 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
957 const void *opt, const void *end, const struct sockaddr_in6 *from)
958 {
959 dhcpv6_handle_advert(orig, rc, opt, end, from);
960 if (dhcpv6_commit_advert() < 0)
961 return -1;
962
963 return dhcpv6_handle_reply(orig, rc, opt, end, from);
964 }
965
966 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
967 const void *opt, const void *end, const struct sockaddr_in6 *from)
968 {
969 uint8_t *odata;
970 uint16_t otype, olen;
971 uint32_t refresh = 86400;
972 int ret = 1;
973 unsigned int updated_IAs = 0;
974 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
975
976 odhcp6c_expire();
977
978 if (orig == DHCPV6_MSG_UNKNOWN) {
979 static time_t last_update = 0;
980 time_t now = odhcp6c_get_milli_time() / 1000;
981
982 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
983 last_update = now;
984
985 if (t1 != UINT32_MAX)
986 t1 -= elapsed;
987
988 if (t2 != UINT32_MAX)
989 t2 -= elapsed;
990
991 if (t3 != UINT32_MAX)
992 t3 -= elapsed;
993
994 if (t1 < 0)
995 t1 = 0;
996
997 if (t2 < 0)
998 t2 = 0;
999
1000 if (t3 < 0)
1001 t3 = 0;
1002 }
1003
1004 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
1005 // Delete NA and PD we have in the state from the Advert
1006 odhcp6c_clear_state(STATE_IA_NA);
1007 odhcp6c_clear_state(STATE_IA_PD);
1008 }
1009
1010 if (opt) {
1011 odhcp6c_clear_state(STATE_DNS);
1012 odhcp6c_clear_state(STATE_SEARCH);
1013 odhcp6c_clear_state(STATE_SNTP_IP);
1014 odhcp6c_clear_state(STATE_NTP_IP);
1015 odhcp6c_clear_state(STATE_NTP_FQDN);
1016 odhcp6c_clear_state(STATE_SIP_IP);
1017 odhcp6c_clear_state(STATE_SIP_FQDN);
1018 odhcp6c_clear_state(STATE_AFTR_NAME);
1019 odhcp6c_clear_state(STATE_CER);
1020 odhcp6c_clear_state(STATE_S46_MAPT);
1021 odhcp6c_clear_state(STATE_S46_MAPE);
1022 odhcp6c_clear_state(STATE_S46_LW);
1023 odhcp6c_clear_state(STATE_PASSTHRU);
1024 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
1025
1026 // Parse and find all matching IAs
1027 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
1028 struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype);
1029
1030 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1031 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1032 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1033
1034 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1035 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1036 continue;
1037
1038 // Test ID
1039 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1040 continue;
1041
1042 uint16_t code = DHCPV6_Success;
1043 uint16_t stype, slen;
1044 uint8_t *sdata;
1045 // Get and handle status code
1046 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1047 stype, slen, sdata) {
1048 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1049 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1050 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1051
1052 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1053
1054 if (code == DHCPV6_Success)
1055 continue;
1056
1057 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1058 code, mdata, mlen, handled_status_codes, &ret);
1059
1060 if (ret > 0)
1061 return ret;
1062
1063 break;
1064 }
1065 }
1066
1067 if (code != DHCPV6_Success)
1068 continue;
1069
1070 updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen);
1071 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1072 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
1073 server_addr = *(struct in6_addr *)odata;
1074
1075 }
1076 else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1077 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1078 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1079 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1080
1081 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1082 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1083 if (olen % 16 == 0)
1084 odhcp6c_add_state(STATE_DNS, odata, olen);
1085 } else if (otype == DHCPV6_OPT_DNS_DOMAIN)
1086 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1087 else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1088 if (olen % 16 == 0)
1089 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1090 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1091 uint16_t stype, slen;
1092 uint8_t *sdata;
1093 // Test status and bail if error
1094 dhcpv6_for_each_option(odata, odata + olen,
1095 stype, slen, sdata) {
1096 if (slen == 16 && (stype == NTP_MC_ADDR ||
1097 stype == NTP_SRV_ADDR))
1098 odhcp6c_add_state(STATE_NTP_IP,
1099 sdata, slen);
1100 else if (slen > 0 && stype == NTP_SRV_FQDN)
1101 odhcp6c_add_state(STATE_NTP_FQDN,
1102 sdata, slen);
1103 }
1104 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1105 if (olen == 16)
1106 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1107 } else if (otype == DHCPV6_OPT_SIP_SERVER_D)
1108 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1109 else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1110 refresh = ntohl_unaligned(odata);
1111 } else if (otype == DHCPV6_OPT_AUTH) {
1112 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1113 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1114 if (r->protocol == 3 && r->algorithm == 1 &&
1115 r->reconf_type == 1)
1116 memcpy(reconf_key, r->key, sizeof(r->key));
1117 }
1118 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1119 size_t cur_len;
1120 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1121 if (cur_len == 0)
1122 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1123 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1124 uint32_t sol_max_rt = ntohl_unaligned(odata);
1125 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1126 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1127 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1128 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1129 uint32_t inf_max_rt = ntohl_unaligned(odata);
1130 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1131 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1132 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1133 #ifdef EXT_CER_ID
1134 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1135 sizeof(struct dhcpv6_cer_id)) {
1136 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1137 struct in6_addr any = IN6ADDR_ANY_INIT;
1138 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1139 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1140 #endif
1141 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1142 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1143 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1144 size_t mape_len;
1145 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1146 if (mape_len == 0)
1147 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1148 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1149 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1150 } else
1151 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1152
1153 if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU))
1154 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1155 }
1156 }
1157
1158 switch (orig) {
1159 case DHCPV6_MSG_REQUEST:
1160 case DHCPV6_MSG_REBIND:
1161 case DHCPV6_MSG_RENEW:
1162 // Update refresh timers if no fatal status code was received
1163 if ((ret > 0) && (ret = dhcpv6_calc_refresh_timers())) {
1164 if (orig == DHCPV6_MSG_REQUEST) {
1165 // All server candidates can be cleared if not yet bound
1166 if (!odhcp6c_is_bound())
1167 dhcpv6_clear_all_server_cand();
1168
1169 odhcp6c_clear_state(STATE_SERVER_ADDR);
1170 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1171 } else if (orig == DHCPV6_MSG_RENEW) {
1172 // Send further renews if T1 is not set and
1173 // no updated IAs
1174 if (!t1) {
1175 if (!updated_IAs)
1176 ret = -1;
1177 else if ((t2 - t1) > 1)
1178 // Grace period of 1 second
1179 t1 = 1;
1180 }
1181
1182 } else if (orig == DHCPV6_MSG_REBIND) {
1183 // Send further rebinds if T1 and T2 is not set and
1184 // no updated IAs
1185 if (!t1 && !t2) {
1186 if (!updated_IAs)
1187 ret = -1;
1188 else if ((t3 - t2) > 1)
1189 // Grace period of 1 second
1190 t2 = 1;
1191 }
1192
1193 odhcp6c_clear_state(STATE_SERVER_ADDR);
1194 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1195 }
1196 }
1197 break;
1198
1199 case DHCPV6_MSG_INFO_REQ:
1200 if (ret > 0) {
1201 // All server candidates can be cleared if not yet bound
1202 if (!odhcp6c_is_bound())
1203 dhcpv6_clear_all_server_cand();
1204
1205 t1 = refresh;
1206 }
1207 break;
1208
1209 default:
1210 break;
1211 }
1212
1213 return ret;
1214 }
1215
1216 static unsigned int dhcpv6_parse_ia(void *opt, void *end)
1217 {
1218 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1219 unsigned int updated_IAs = 0;
1220 uint32_t t1, t2;
1221 uint16_t otype, olen;
1222 uint8_t *odata;
1223
1224 t1 = ntohl(ia_hdr->t1);
1225 t2 = ntohl(ia_hdr->t2);
1226
1227 if (t1 > t2)
1228 return 0;
1229
1230 // Update address IA
1231 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1232 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1233 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1234
1235 entry.iaid = ia_hdr->iaid;
1236
1237 if (otype == DHCPV6_OPT_IA_PREFIX) {
1238 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1239 if (olen + 4U < sizeof(*prefix))
1240 continue;
1241
1242 entry.valid = ntohl(prefix->valid);
1243 entry.preferred = ntohl(prefix->preferred);
1244
1245 if (entry.preferred > entry.valid)
1246 continue;
1247
1248 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1249 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1250 if (entry.t1 > entry.t2)
1251 entry.t1 = entry.t2;
1252
1253 entry.length = prefix->prefix;
1254 entry.target = prefix->addr;
1255 uint16_t stype, slen;
1256 uint8_t *sdata;
1257
1258 // Parse PD-exclude
1259 bool ok = true;
1260 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1261 odata + olen, stype, slen, sdata) {
1262 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1263 continue;
1264
1265 uint8_t elen = sdata[0];
1266 if (elen > 64)
1267 elen = 64;
1268
1269 if (entry.length < 32 || elen <= entry.length) {
1270 ok = false;
1271 continue;
1272 }
1273
1274 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1275 if (slen <= bytes) {
1276 ok = false;
1277 continue;
1278 }
1279
1280 uint32_t exclude = 0;
1281 do {
1282 exclude = exclude << 8 | sdata[bytes];
1283 } while (--bytes);
1284
1285 exclude >>= 8 - ((elen - entry.length) % 8);
1286 exclude <<= 64 - elen;
1287
1288 // Abusing router & priority fields for exclusion
1289 entry.router = entry.target;
1290 entry.router.s6_addr32[1] |= htonl(exclude);
1291 entry.priority = elen;
1292 }
1293
1294 if (ok) {
1295 if (odhcp6c_update_entry(STATE_IA_PD, &entry, 0, 0))
1296 updated_IAs++;
1297 }
1298
1299 entry.priority = 0;
1300 memset(&entry.router, 0, sizeof(entry.router));
1301 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1302 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1303 if (olen + 4U < sizeof(*addr))
1304 continue;
1305
1306 entry.preferred = ntohl(addr->preferred);
1307 entry.valid = ntohl(addr->valid);
1308
1309 if (entry.preferred > entry.valid)
1310 continue;
1311
1312 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1313 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1314 if (entry.t1 > entry.t2)
1315 entry.t1 = entry.t2;
1316
1317 entry.length = 128;
1318 entry.target = addr->addr;
1319
1320 if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0))
1321 updated_IAs++;
1322 }
1323 }
1324 return updated_IAs;
1325 }
1326
1327 static int dhcpv6_calc_refresh_timers(void)
1328 {
1329 struct odhcp6c_entry *e;
1330 size_t ia_na_entries, ia_pd_entries, i;
1331 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1332
1333 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1334 ia_na_entries /= sizeof(*e);
1335
1336 for (i = 0; i < ia_na_entries; i++) {
1337 if (e[i].t1 < l_t1)
1338 l_t1 = e[i].t1;
1339
1340 if (e[i].t2 < l_t2)
1341 l_t2 = e[i].t2;
1342
1343 if (e[i].valid > l_t3)
1344 l_t3 = e[i].valid;
1345 }
1346
1347 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1348 ia_pd_entries /= sizeof(*e);
1349
1350 for (i = 0; i < ia_pd_entries; i++) {
1351 if (e[i].t1 < l_t1)
1352 l_t1 = e[i].t1;
1353
1354 if (e[i].t2 < l_t2)
1355 l_t2 = e[i].t2;
1356
1357 if (e[i].valid > l_t3)
1358 l_t3 = e[i].valid;
1359 }
1360
1361 if (ia_pd_entries || ia_na_entries) {
1362 t1 = l_t1;
1363 t2 = l_t2;
1364 t3 = l_t3;
1365 }
1366
1367 return (int)(ia_pd_entries + ia_na_entries);
1368 }
1369
1370 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1371 const void *status_msg, int len)
1372 {
1373 const char *src = status_msg;
1374 char buf[len + 3];
1375 char *dst = buf;
1376
1377 if (len) {
1378 *dst++ = '(';
1379 while (len--) {
1380 *dst = isprint((unsigned char)*src) ? *src : '?';
1381 src++;
1382 dst++;
1383 }
1384 *dst++ = ')';
1385 }
1386
1387 *dst = 0;
1388
1389 syslog(LOG_WARNING, "Server returned %s status %i %s",
1390 scope, code, buf);
1391 }
1392
1393 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1394 const uint16_t code, const void *status_msg, const int len,
1395 int *ret)
1396 {
1397 dhcpv6_log_status_code(code, "message", status_msg, len);
1398
1399 switch (code) {
1400 case DHCPV6_UnspecFail:
1401 // Generic failure
1402 *ret = 0;
1403 break;
1404
1405 case DHCPV6_UseMulticast:
1406 switch(orig) {
1407 case DHCPV6_MSG_REQUEST:
1408 case DHCPV6_MSG_RENEW:
1409 case DHCPV6_MSG_RELEASE:
1410 case DHCPV6_MSG_DECLINE:
1411 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1412 server_addr = in6addr_any;
1413 *ret = 0;
1414 break;
1415 default:
1416 break;
1417 }
1418 break;
1419
1420 case DHCPV6_NoAddrsAvail:
1421 case DHCPV6_NoPrefixAvail:
1422 if (orig == DHCPV6_MSG_REQUEST)
1423 *ret = 0; // Failure
1424 break;
1425
1426 default:
1427 break;
1428 }
1429 }
1430
1431 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1432 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1433 const void *status_msg, const int len,
1434 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1435 {
1436 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1437 "IA_NA" : "IA_PD", status_msg, len);
1438
1439 switch (code) {
1440 case DHCPV6_NoBinding:
1441 switch (orig) {
1442 case DHCPV6_MSG_RENEW:
1443 case DHCPV6_MSG_REBIND:
1444 if ((*ret > 0) && !handled_status_codes[code])
1445 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1446 break;
1447
1448 default:
1449 break;
1450 }
1451 break;
1452
1453 default:
1454 *ret = 0;
1455 break;
1456 }
1457 }
1458
1459 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1460 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1461 {
1462 size_t cand_len, i;
1463 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1464
1465 // Remove identical duid server candidate
1466 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1467 if (cand->duid_len == c[i].duid_len &&
1468 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1469 free(c[i].ia_na);
1470 free(c[i].ia_pd);
1471 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1472 break;
1473 }
1474 }
1475
1476 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1477 i < cand_len / sizeof(*c); ++i) {
1478 if (c[i].preference < cand->preference)
1479 break;
1480 }
1481
1482 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1483 free(cand->ia_na);
1484 free(cand->ia_pd);
1485 }
1486 }
1487
1488 static void dhcpv6_clear_all_server_cand(void)
1489 {
1490 size_t cand_len, i;
1491 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1492
1493 // Server candidates need deep delete for IA_NA/IA_PD
1494 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1495 free(c[i].ia_na);
1496 free(c[i].ia_pd);
1497 }
1498 odhcp6c_clear_state(STATE_SERVER_CAND);
1499 }
1500
1501 int dhcpv6_promote_server_cand(void)
1502 {
1503 size_t cand_len;
1504 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1505 uint16_t hdr[2];
1506 int ret = DHCPV6_STATELESS;
1507
1508 // Clear lingering candidate state info
1509 odhcp6c_clear_state(STATE_SERVER_ID);
1510 odhcp6c_clear_state(STATE_IA_NA);
1511 odhcp6c_clear_state(STATE_IA_PD);
1512
1513 if (!cand_len)
1514 return -1;
1515
1516 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1517 na_mode = IA_MODE_NONE;
1518
1519 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1520 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1521
1522 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1523 }
1524
1525 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1526 hdr[1] = htons(cand->duid_len);
1527 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1528 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1529 accept_reconfig = cand->wants_reconfigure;
1530
1531 if (cand->ia_na_len) {
1532 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1533 free(cand->ia_na);
1534 if (na_mode != IA_MODE_NONE)
1535 ret = DHCPV6_STATEFUL;
1536 }
1537
1538 if (cand->ia_pd_len) {
1539 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1540 free(cand->ia_pd);
1541 if (pd_mode != IA_MODE_NONE)
1542 ret = DHCPV6_STATEFUL;
1543 }
1544
1545 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1546 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1547
1548 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1549
1550 return ret;
1551 }
Openwrt DHCPv6 Client