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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 htons(DHCPV6_OPT_SOL_MAX_RT),
190 htons(DHCPV6_OPT_INF_MAX_RT),
191 #ifdef EXT_CER_ID
192 htons(DHCPV6_OPT_CER_ID),
193 #endif
194 htons(DHCPV6_OPT_S46_CONT_MAPE),
195 htons(DHCPV6_OPT_S46_CONT_MAPT),
196 htons(DHCPV6_OPT_S46_CONT_LW),
197 };
198 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
199 }
200 // Required oro
201 uint16_t req_oro[] = {
202 htons(DHCPV6_OPT_INF_MAX_RT),
203 htons(DHCPV6_OPT_SOL_MAX_RT),
204 htons(DHCPV6_OPT_INFO_REFRESH),
205 };
206 odhcp6c_add_state(STATE_ORO, req_oro, sizeof(req_oro));
207
208 // Configure IPv6-options
209 int val = 1;
210 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
211 goto failure;
212
213 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
214 goto failure;
215
216 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
217 goto failure;
218
219 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
220 goto failure;
221
222 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
223 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
224
225 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
226 goto failure;
227
228 return 0;
229
230 failure:
231 if (sock >= 0)
232 close(sock);
233
234 return -1;
235 }
236
237 enum {
238 IOV_HDR=0,
239 IOV_ORO,
240 IOV_CL_ID,
241 IOV_SRV_ID,
242 IOV_OPTS,
243 IOV_RECONF_ACCEPT,
244 IOV_FQDN,
245 IOV_HDR_IA_NA,
246 IOV_IA_NA,
247 IOV_IA_PD,
248 IOV_TOTAL
249 };
250
251 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
252 {
253 int mode = DHCPV6_UNKNOWN;
254
255 na_mode = na;
256 pd_mode = pd;
257
258 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
259 mode = DHCPV6_STATELESS;
260 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
261 mode = DHCPV6_STATEFUL;
262
263 return mode;
264 }
265
266 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
267 {
268 // Build FQDN
269 char fqdn_buf[256];
270 gethostname(fqdn_buf, sizeof(fqdn_buf));
271 struct {
272 uint16_t type;
273 uint16_t len;
274 uint8_t flags;
275 uint8_t data[256];
276 } fqdn;
277 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
278 sizeof(fqdn.data), NULL, NULL);
279 fqdn.type = htons(DHCPV6_OPT_FQDN);
280 fqdn.len = htons(fqdn_len - 4);
281 fqdn.flags = 0;
282
283 // Build Client ID
284 size_t cl_id_len;
285 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
286
287 // Get Server ID
288 size_t srv_id_len;
289 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
290
291 // Build IA_PDs
292 size_t ia_pd_entries = 0, ia_pd_len = 0;
293 uint8_t *ia_pd;
294
295 if (type == DHCPV6_MSG_SOLICIT) {
296 odhcp6c_clear_state(STATE_IA_PD);
297 size_t n_prefixes;
298 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
299 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
300
301 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
302
303 for (size_t i = 0; i < n_prefixes; i++) {
304 struct dhcpv6_ia_hdr hdr_ia_pd = {
305 htons(DHCPV6_OPT_IA_PD),
306 htons(sizeof(hdr_ia_pd) - 4 +
307 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
308 request_prefixes[i].iaid, 0, 0
309 };
310 struct dhcpv6_ia_prefix pref = {
311 .type = htons(DHCPV6_OPT_IA_PREFIX),
312 .len = htons(sizeof(pref) - 4),
313 .prefix = request_prefixes[i].length
314 };
315 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
316 ia_pd_len += sizeof(hdr_ia_pd);
317 if (request_prefixes[i].length) {
318 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
319 ia_pd_len += sizeof(pref);
320 }
321 }
322 } else {
323 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
324 ia_pd_entries /= sizeof(*e);
325
326 // we're too lazy to count our distinct IAIDs,
327 // so just allocate maximally needed space
328 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
329 sizeof(struct dhcpv6_ia_hdr)));
330
331 for (size_t i = 0; i < ia_pd_entries; ++i) {
332 uint32_t iaid = e[i].iaid;
333
334 // check if this is an unprocessed IAID and skip if not.
335 int new_iaid = 1;
336 for (int j = i-1; j >= 0; j--) {
337 if (e[j].iaid == iaid) {
338 new_iaid = 0;
339 break;
340 }
341 }
342
343 if (!new_iaid)
344 continue;
345
346 // construct header
347 struct dhcpv6_ia_hdr hdr_ia_pd = {
348 htons(DHCPV6_OPT_IA_PD),
349 htons(sizeof(hdr_ia_pd) - 4),
350 iaid, 0, 0
351 };
352
353 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
354 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
355 ia_pd_len += sizeof(hdr_ia_pd);
356
357 for (size_t j = i; j < ia_pd_entries; j++) {
358 if (e[j].iaid != iaid)
359 continue;
360
361 uint8_t ex_len = 0;
362 if (e[j].priority > 0)
363 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
364
365 struct dhcpv6_ia_prefix p = {
366 .type = htons(DHCPV6_OPT_IA_PREFIX),
367 .len = htons(sizeof(p) - 4U + ex_len),
368 .prefix = e[j].length,
369 .addr = e[j].target
370 };
371
372 if (type == DHCPV6_MSG_REQUEST) {
373 p.preferred = htonl(e[j].preferred);
374 p.valid = htonl(e[j].valid);
375 }
376
377 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
378 ia_pd_len += sizeof(p);
379
380 if (ex_len) {
381 ia_pd[ia_pd_len++] = 0;
382 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
383 ia_pd[ia_pd_len++] = 0;
384 ia_pd[ia_pd_len++] = ex_len - 4;
385 ia_pd[ia_pd_len++] = e[j].priority;
386
387 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
388 excl >>= (64 - e[j].priority);
389 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
390
391 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
392 ia_pd[ia_pd_len + i] = excl & 0xff;
393 ia_pd_len += ex_len - 5;
394 }
395
396 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
397 }
398 }
399 }
400
401 // Build IA_NAs
402 size_t ia_na_entries, ia_na_len = 0;
403 void *ia_na = NULL;
404 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
405 ia_na_entries /= sizeof(*e);
406
407 struct dhcpv6_ia_hdr hdr_ia_na = {
408 htons(DHCPV6_OPT_IA_NA),
409 htons(sizeof(hdr_ia_na) - 4),
410 htonl(1), 0, 0
411 };
412
413 struct dhcpv6_ia_addr pa[ia_na_entries];
414 for (size_t i = 0; i < ia_na_entries; ++i) {
415 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
416 pa[i].len = htons(sizeof(pa[i]) - 4U);
417 pa[i].addr = e[i].target;
418
419 if (type == DHCPV6_MSG_REQUEST) {
420 pa[i].preferred = htonl(e[i].preferred);
421 pa[i].valid = htonl(e[i].valid);
422 } else {
423 pa[i].preferred = 0;
424 pa[i].valid = 0;
425 }
426 }
427
428 ia_na = pa;
429 ia_na_len = sizeof(pa);
430 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
431
432 // Reconfigure Accept
433 struct {
434 uint16_t type;
435 uint16_t length;
436 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
437
438 // Option list
439 size_t opts_len;
440 void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len);
441
442 // Option Request List
443 size_t oro_entries, oro_len = 0;
444 uint16_t *oro, *s_oro = odhcp6c_get_state(STATE_ORO, &oro_entries);
445
446 oro_entries /= sizeof(*s_oro);
447 oro = alloca(oro_entries * sizeof(*oro));
448
449 for (size_t i = 0; i < oro_entries; i++) {
450 struct odhcp6c_opt *opt = odhcp6c_find_opt(htons(s_oro[i]));
451
452 if (opt) {
453 if (!(opt->flags & OPT_ORO))
454 continue;
455
456 if ((opt->flags & OPT_ORO_SOLICIT) && type != DHCPV6_MSG_SOLICIT)
457 continue;
458
459 if ((opt->flags & OPT_ORO_STATELESS) && type != DHCPV6_MSG_INFO_REQ)
460 continue;
461
462 if ((opt->flags & OPT_ORO_STATEFUL) && type == DHCPV6_MSG_INFO_REQ)
463 continue;
464 }
465
466 oro[oro_len++] = s_oro[i];
467 }
468 oro_len *= sizeof(*oro);
469
470 // Prepare Header
471 struct {
472 uint8_t type;
473 uint8_t trid[3];
474 uint16_t elapsed_type;
475 uint16_t elapsed_len;
476 uint16_t elapsed_value;
477 uint16_t oro_type;
478 uint16_t oro_len;
479 } hdr = {
480 type, {trid[0], trid[1], trid[2]},
481 htons(DHCPV6_OPT_ELAPSED), htons(2),
482 htons((ecs > 0xffff) ? 0xffff : ecs),
483 htons(DHCPV6_OPT_ORO), htons(oro_len),
484 };
485
486 struct iovec iov[IOV_TOTAL] = {
487 [IOV_HDR] = {&hdr, sizeof(hdr)},
488 [IOV_ORO] = {oro, oro_len},
489 [IOV_CL_ID] = {cl_id, cl_id_len},
490 [IOV_SRV_ID] = {srv_id, srv_id_len},
491 [IOV_OPTS] = { opts, opts_len },
492 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
493 [IOV_FQDN] = {&fqdn, fqdn_len},
494 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
495 [IOV_IA_NA] = {ia_na, ia_na_len},
496 [IOV_IA_PD] = {ia_pd, ia_pd_len},
497 };
498
499 size_t cnt = IOV_TOTAL;
500 if (type == DHCPV6_MSG_INFO_REQ)
501 cnt = IOV_HDR_IA_NA;
502
503 // Disable IAs if not used
504 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
505 iov[IOV_HDR_IA_NA].iov_len = 0;
506
507 if (na_mode == IA_MODE_NONE)
508 iov[IOV_HDR_IA_NA].iov_len = 0;
509
510 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
511 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
512 iov[IOV_RECONF_ACCEPT].iov_len = 0;
513
514 if (!(client_options & DHCPV6_CLIENT_FQDN))
515 iov[IOV_FQDN].iov_len = 0;
516
517 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
518 0, ALL_DHCPV6_RELAYS, ifindex};
519 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
520 .msg_iov = iov, .msg_iovlen = cnt};
521
522 switch (type) {
523 case DHCPV6_MSG_REQUEST:
524 case DHCPV6_MSG_RENEW:
525 case DHCPV6_MSG_RELEASE:
526 case DHCPV6_MSG_DECLINE:
527 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
528 odhcp6c_addr_in_scope(&server_addr)) {
529 srv.sin6_addr = server_addr;
530 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
531 srv.sin6_scope_id = 0;
532 }
533 break;
534 default:
535 break;
536 }
537
538 if (sendmsg(sock, &msg, 0) < 0) {
539 char in6_str[INET6_ADDRSTRLEN];
540
541 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
542 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
543 in6_str, sizeof(in6_str)), strerror(errno));
544 }
545 }
546
547 static int64_t dhcpv6_rand_delay(int64_t time)
548 {
549 int random;
550 odhcp6c_random(&random, sizeof(random));
551
552 return (time * ((int64_t)random % 1000LL)) / 10000LL;
553 }
554
555 int dhcpv6_request(enum dhcpv6_msg type)
556 {
557 uint8_t rc = 0;
558 uint64_t timeout = UINT32_MAX;
559 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
560
561 if (retx->delay) {
562 struct timespec ts = {0, 0};
563 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
564
565 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
566 }
567
568 if (type == DHCPV6_MSG_UNKNOWN)
569 timeout = t1;
570 else if (type == DHCPV6_MSG_RENEW)
571 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
572 else if (type == DHCPV6_MSG_REBIND)
573 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
574
575 if (timeout == 0)
576 return -1;
577
578 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
579 retx->name, timeout, retx->max_rc);
580
581 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
582
583 // Generate transaction ID
584 uint8_t trid[3] = {0, 0, 0};
585 if (type != DHCPV6_MSG_UNKNOWN)
586 odhcp6c_random(trid, sizeof(trid));
587
588 ssize_t len = -1;
589 int64_t rto = 0;
590
591 do {
592 if (rto == 0) {
593 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
594
595 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
596 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
597 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
598
599 rto = (retx->init_timeo * 1000 + delay);
600 } else
601 rto = (2 * rto + dhcpv6_rand_delay(rto));
602
603 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
604 rto = retx->max_timeo * 1000 +
605 dhcpv6_rand_delay(retx->max_timeo * 1000);
606
607 // Calculate end for this round and elapsed time
608 uint64_t round_end = round_start + rto;
609 elapsed = round_start - start;
610
611 // Don't wait too long if timeout differs from infinite
612 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
613 round_end = timeout * 1000 + start;
614
615 // Built and send package
616 switch (type) {
617 case DHCPV6_MSG_UNKNOWN:
618 break;
619 default:
620 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
621 retx->name, elapsed, rc);
622 // Fall through
623 case DHCPV6_MSG_SOLICIT:
624 case DHCPV6_MSG_INFO_REQ:
625 dhcpv6_send(type, trid, elapsed / 10);
626 rc++;
627 }
628
629 // Receive rounds
630 for (; len < 0 && (round_start < round_end);
631 round_start = odhcp6c_get_milli_time()) {
632 uint8_t buf[1536];
633 union {
634 struct cmsghdr hdr;
635 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
636 } cmsg_buf;
637 struct iovec iov = {buf, sizeof(buf)};
638 struct sockaddr_in6 addr;
639 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
640 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
641 .msg_controllen = sizeof(cmsg_buf)};
642 struct in6_pktinfo *pktinfo = NULL;
643
644 // Check for pending signal
645 if (odhcp6c_signal_process())
646 return -1;
647
648 // Set timeout for receiving
649 uint64_t t = round_end - round_start;
650 struct timeval tv = {t / 1000, (t % 1000) * 1000};
651 if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
652 &tv, sizeof(tv)) < 0)
653 syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)",
654 strerror(errno));
655
656 // Receive cycle
657 len = recvmsg(sock, &msg, 0);
658 if (len < 0)
659 continue;
660
661 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
662 ch = CMSG_NXTHDR(&msg, ch)) {
663 if (ch->cmsg_level == SOL_IPV6 &&
664 ch->cmsg_type == IPV6_PKTINFO) {
665 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
666 break;
667 }
668 }
669
670 if (pktinfo == NULL) {
671 len = -1;
672 continue;
673 }
674
675 if (!dhcpv6_response_is_valid(buf, len, trid,
676 type, &pktinfo->ipi6_addr)) {
677 len = -1;
678 continue;
679 }
680
681 uint8_t *opt = &buf[4];
682 uint8_t *opt_end = opt + len - 4;
683
684 round_start = odhcp6c_get_milli_time();
685 elapsed = round_start - start;
686 syslog(LOG_NOTICE, "Got a valid reply after %"PRIu64"ms",
687 elapsed);
688
689 if (retx->handler_reply)
690 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
691
692 if (len > 0 && round_end - round_start > 1000)
693 round_end = 1000 + round_start;
694 }
695
696 // Allow
697 if (retx->handler_finish)
698 len = retx->handler_finish();
699 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
700 (!retx->max_rc || rc < retx->max_rc));
701 return len;
702 }
703
704 // Message validation checks according to RFC3315 chapter 15
705 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
706 const uint8_t transaction[3], enum dhcpv6_msg type,
707 const struct in6_addr *daddr)
708 {
709 const struct dhcpv6_header *rep = buf;
710 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
711 transaction, sizeof(rep->tr_id)))
712 return false; // Invalid reply
713
714 if (type == DHCPV6_MSG_SOLICIT) {
715 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
716 rep->msg_type != DHCPV6_MSG_REPLY)
717 return false;
718
719 } else if (type == DHCPV6_MSG_UNKNOWN) {
720 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
721 return false;
722
723 } else if (rep->msg_type != DHCPV6_MSG_REPLY)
724 return false;
725
726 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
727 rcmsg = DHCPV6_MSG_UNKNOWN;
728 uint16_t otype, olen = UINT16_MAX;
729 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
730 ia_present = false, options_valid = true;
731
732 size_t client_id_len, server_id_len;
733 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
734 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
735
736 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
737 if (otype == DHCPV6_OPT_CLIENTID) {
738 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
739 &odata[-4], client_id, client_id_len);
740 } else if (otype == DHCPV6_OPT_SERVERID) {
741 if (server_id_len)
742 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
743 &odata[-4], server_id, server_id_len);
744 else
745 serverid_ok = true;
746 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
747 sizeof(struct dhcpv6_auth_reconfigure)) {
748 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
749 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
750 continue;
751
752 md5_ctx_t md5;
753 uint8_t serverhash[16], secretbytes[64];
754 uint32_t hash[4];
755 memcpy(serverhash, r->key, sizeof(serverhash));
756 memset(r->key, 0, sizeof(r->key));
757
758 memset(secretbytes, 0, sizeof(secretbytes));
759 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
760
761 for (size_t i = 0; i < sizeof(secretbytes); ++i)
762 secretbytes[i] ^= 0x36;
763
764 md5_begin(&md5);
765 md5_hash(secretbytes, sizeof(secretbytes), &md5);
766 md5_hash(buf, len, &md5);
767 md5_end(hash, &md5);
768
769 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
770 secretbytes[i] ^= 0x36;
771 secretbytes[i] ^= 0x5c;
772 }
773
774 md5_begin(&md5);
775 md5_hash(secretbytes, sizeof(secretbytes), &md5);
776 md5_hash(hash, 16, &md5);
777 md5_end(hash, &md5);
778
779 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
780 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
781 rcmsg = odata[0];
782 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
783 ia_present = true;
784 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
785 options_valid = false;
786 } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
787 (otype == DHCPV6_OPT_PD_EXCLUDE))
788 // Options are not allowed on global level
789 options_valid = false;
790 }
791
792 if (!options_valid || ((odata + olen) > end))
793 return false;
794
795 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
796 return false;
797
798 if (rep->msg_type == DHCPV6_MSG_RECONF) {
799 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) ||
800 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
801 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
802 return false;
803 }
804
805 return clientid_ok && serverid_ok;
806 }
807
808 int dhcpv6_poll_reconfigure(void)
809 {
810 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
811
812 if (ret != -1)
813 ret = dhcpv6_request(ret);
814
815 return ret;
816 }
817
818 static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc,
819 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
820 {
821 uint16_t otype, olen;
822 uint8_t *odata;
823 int msg = -1;
824
825 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
826 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
827 switch (odata[0]) {
828 case DHCPV6_MSG_REBIND:
829 if (t2 != UINT32_MAX)
830 t2 = 0;
831 // Fall through
832 case DHCPV6_MSG_RENEW:
833 if (t1 != UINT32_MAX)
834 t1 = 0;
835 // Fall through
836 case DHCPV6_MSG_INFO_REQ:
837 msg = odata[0];
838 break;
839
840 default:
841 break;
842 }
843 }
844 }
845
846 dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL);
847
848 return msg;
849 }
850
851 // Collect all advertised servers
852 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
853 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
854 {
855 uint16_t olen, otype;
856 uint8_t *odata, pref = 0;
857 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
858 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
859 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
860 bool have_na = false;
861 int have_pd = 0;
862
863 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
864 if (orig == DHCPV6_MSG_SOLICIT &&
865 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
866 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
867 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
868 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
869 }
870
871 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
872 memcpy(cand.duid, odata, olen);
873 cand.duid_len = olen;
874 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
875 cand.preference >= 0) {
876 cand.preference = pref = odata[0];
877 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
878 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
879 cand.server_addr = *(struct in6_addr *)odata;
880
881 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
882 cand.wants_reconfigure = true;
883 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
884 uint32_t sol_max_rt = ntohl_unaligned(odata);
885 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
886 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
887 cand.sol_max_rt = sol_max_rt;
888
889 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
890 uint32_t inf_max_rt = ntohl_unaligned(odata);
891 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
892 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
893 cand.inf_max_rt = inf_max_rt;
894
895 } else if (otype == DHCPV6_OPT_IA_PD &&
896 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
897 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
898 uint8_t *oend = odata + olen, *d;
899 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
900 if (otype == DHCPV6_OPT_IA_PREFIX &&
901 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
902 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
903 have_pd = p->prefix;
904 }
905 }
906 } else if (otype == DHCPV6_OPT_IA_NA &&
907 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
908 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
909 uint8_t *oend = odata + olen, *d;
910
911 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
912 if (otype == DHCPV6_OPT_IA_ADDR &&
913 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
914 have_na = true;
915 }
916 }
917 }
918
919 if ((!have_na && na_mode == IA_MODE_FORCE) ||
920 (!have_pd && pd_mode == IA_MODE_FORCE)) {
921 /*
922 * RFC7083 states to process the SOL_MAX_RT and
923 * INF_MAX_RT options even if the DHCPv6 server
924 * did not propose any IA_NA and/or IA_PD
925 */
926 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
927 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
928 return -1;
929 }
930
931 if (na_mode != IA_MODE_NONE && !have_na) {
932 cand.has_noaddravail = true;
933 cand.preference -= 1000;
934 }
935
936 if (pd_mode != IA_MODE_NONE) {
937 if (have_pd)
938 cand.preference += 2000 + (128 - have_pd);
939 else
940 cand.preference -= 2000;
941 }
942
943 if (cand.duid_len > 0) {
944 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
945 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
946 dhcpv6_add_server_cand(&cand);
947 }
948
949 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
950 }
951
952 static int dhcpv6_commit_advert(void)
953 {
954 return dhcpv6_promote_server_cand();
955 }
956
957 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
958 const void *opt, const void *end, const struct sockaddr_in6 *from)
959 {
960 dhcpv6_handle_advert(orig, rc, opt, end, from);
961 if (dhcpv6_commit_advert() < 0)
962 return -1;
963
964 return dhcpv6_handle_reply(orig, rc, opt, end, from);
965 }
966
967 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
968 const void *opt, const void *end, const struct sockaddr_in6 *from)
969 {
970 uint8_t *odata;
971 uint16_t otype, olen;
972 uint32_t refresh = 86400;
973 int ret = 1;
974 unsigned int updated_IAs = 0;
975 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
976
977 odhcp6c_expire();
978
979 if (orig == DHCPV6_MSG_UNKNOWN) {
980 static time_t last_update = 0;
981 time_t now = odhcp6c_get_milli_time() / 1000;
982
983 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
984 last_update = now;
985
986 if (t1 != UINT32_MAX)
987 t1 -= elapsed;
988
989 if (t2 != UINT32_MAX)
990 t2 -= elapsed;
991
992 if (t3 != UINT32_MAX)
993 t3 -= elapsed;
994
995 if (t1 < 0)
996 t1 = 0;
997
998 if (t2 < 0)
999 t2 = 0;
1000
1001 if (t3 < 0)
1002 t3 = 0;
1003 }
1004
1005 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
1006 // Delete NA and PD we have in the state from the Advert
1007 odhcp6c_clear_state(STATE_IA_NA);
1008 odhcp6c_clear_state(STATE_IA_PD);
1009 }
1010
1011 if (opt) {
1012 odhcp6c_clear_state(STATE_DNS);
1013 odhcp6c_clear_state(STATE_SEARCH);
1014 odhcp6c_clear_state(STATE_SNTP_IP);
1015 odhcp6c_clear_state(STATE_NTP_IP);
1016 odhcp6c_clear_state(STATE_NTP_FQDN);
1017 odhcp6c_clear_state(STATE_SIP_IP);
1018 odhcp6c_clear_state(STATE_SIP_FQDN);
1019 odhcp6c_clear_state(STATE_AFTR_NAME);
1020 odhcp6c_clear_state(STATE_CER);
1021 odhcp6c_clear_state(STATE_S46_MAPT);
1022 odhcp6c_clear_state(STATE_S46_MAPE);
1023 odhcp6c_clear_state(STATE_S46_LW);
1024 odhcp6c_clear_state(STATE_PASSTHRU);
1025 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
1026
1027 // Parse and find all matching IAs
1028 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
1029 struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype);
1030
1031 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1032 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1033 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1034
1035 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1036 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1037 continue;
1038
1039 // Test ID
1040 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1041 continue;
1042
1043 uint16_t code = DHCPV6_Success;
1044 uint16_t stype, slen;
1045 uint8_t *sdata;
1046 // Get and handle status code
1047 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1048 stype, slen, sdata) {
1049 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1050 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1051 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1052
1053 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1054
1055 if (code == DHCPV6_Success)
1056 continue;
1057
1058 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1059 code, mdata, mlen, handled_status_codes, &ret);
1060
1061 if (ret > 0)
1062 return ret;
1063
1064 break;
1065 }
1066 }
1067
1068 if (code != DHCPV6_Success)
1069 continue;
1070
1071 updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen);
1072 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1073 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
1074 server_addr = *(struct in6_addr *)odata;
1075
1076 }
1077 else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1078 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1079 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1080 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1081
1082 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1083 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1084 if (olen % 16 == 0)
1085 odhcp6c_add_state(STATE_DNS, odata, olen);
1086 } else if (otype == DHCPV6_OPT_DNS_DOMAIN)
1087 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1088 else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1089 if (olen % 16 == 0)
1090 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1091 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1092 uint16_t stype, slen;
1093 uint8_t *sdata;
1094 // Test status and bail if error
1095 dhcpv6_for_each_option(odata, odata + olen,
1096 stype, slen, sdata) {
1097 if (slen == 16 && (stype == NTP_MC_ADDR ||
1098 stype == NTP_SRV_ADDR))
1099 odhcp6c_add_state(STATE_NTP_IP,
1100 sdata, slen);
1101 else if (slen > 0 && stype == NTP_SRV_FQDN)
1102 odhcp6c_add_state(STATE_NTP_FQDN,
1103 sdata, slen);
1104 }
1105 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1106 if (olen == 16)
1107 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1108 } else if (otype == DHCPV6_OPT_SIP_SERVER_D)
1109 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1110 else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1111 refresh = ntohl_unaligned(odata);
1112 } else if (otype == DHCPV6_OPT_AUTH) {
1113 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1114 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1115 if (r->protocol == 3 && r->algorithm == 1 &&
1116 r->reconf_type == 1)
1117 memcpy(reconf_key, r->key, sizeof(r->key));
1118 }
1119 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1120 size_t cur_len;
1121 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1122 if (cur_len == 0)
1123 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1124 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1125 uint32_t sol_max_rt = ntohl_unaligned(odata);
1126 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1127 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1128 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1129 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1130 uint32_t inf_max_rt = ntohl_unaligned(odata);
1131 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1132 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1133 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1134 #ifdef EXT_CER_ID
1135 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1136 sizeof(struct dhcpv6_cer_id)) {
1137 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1138 struct in6_addr any = IN6ADDR_ANY_INIT;
1139 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1140 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1141 #endif
1142 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1143 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1144 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1145 size_t mape_len;
1146 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1147 if (mape_len == 0)
1148 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1149 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1150 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1151 } else
1152 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1153
1154 if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU))
1155 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1156 }
1157 }
1158
1159 switch (orig) {
1160 case DHCPV6_MSG_REQUEST:
1161 case DHCPV6_MSG_REBIND:
1162 case DHCPV6_MSG_RENEW:
1163 // Update refresh timers if no fatal status code was received
1164 if ((ret > 0) && (ret = dhcpv6_calc_refresh_timers())) {
1165 if (orig == DHCPV6_MSG_REQUEST) {
1166 // All server candidates can be cleared if not yet bound
1167 if (!odhcp6c_is_bound())
1168 dhcpv6_clear_all_server_cand();
1169
1170 odhcp6c_clear_state(STATE_SERVER_ADDR);
1171 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1172 } else if (orig == DHCPV6_MSG_RENEW) {
1173 // Send further renews if T1 is not set and
1174 // no updated IAs
1175 if (!t1) {
1176 if (!updated_IAs)
1177 ret = -1;
1178 else if ((t2 - t1) > 1)
1179 // Grace period of 1 second
1180 t1 = 1;
1181 }
1182
1183 } else if (orig == DHCPV6_MSG_REBIND) {
1184 // Send further rebinds if T1 and T2 is not set and
1185 // no updated IAs
1186 if (!t1 && !t2) {
1187 if (!updated_IAs)
1188 ret = -1;
1189 else if ((t3 - t2) > 1)
1190 // Grace period of 1 second
1191 t2 = 1;
1192 }
1193
1194 odhcp6c_clear_state(STATE_SERVER_ADDR);
1195 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1196 }
1197 }
1198 break;
1199
1200 case DHCPV6_MSG_INFO_REQ:
1201 if (ret > 0) {
1202 // All server candidates can be cleared if not yet bound
1203 if (!odhcp6c_is_bound())
1204 dhcpv6_clear_all_server_cand();
1205
1206 t1 = refresh;
1207 }
1208 break;
1209
1210 default:
1211 break;
1212 }
1213
1214 return ret;
1215 }
1216
1217 static unsigned int dhcpv6_parse_ia(void *opt, void *end)
1218 {
1219 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1220 unsigned int updated_IAs = 0;
1221 uint32_t t1, t2;
1222 uint16_t otype, olen;
1223 uint8_t *odata;
1224
1225 t1 = ntohl(ia_hdr->t1);
1226 t2 = ntohl(ia_hdr->t2);
1227
1228 if (t1 > t2)
1229 return 0;
1230
1231 // Update address IA
1232 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1233 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1234 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1235
1236 entry.iaid = ia_hdr->iaid;
1237
1238 if (otype == DHCPV6_OPT_IA_PREFIX) {
1239 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1240 if (olen + 4U < sizeof(*prefix))
1241 continue;
1242
1243 entry.valid = ntohl(prefix->valid);
1244 entry.preferred = ntohl(prefix->preferred);
1245
1246 if (entry.preferred > entry.valid)
1247 continue;
1248
1249 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1250 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1251 if (entry.t1 > entry.t2)
1252 entry.t1 = entry.t2;
1253
1254 entry.length = prefix->prefix;
1255 entry.target = prefix->addr;
1256 uint16_t stype, slen;
1257 uint8_t *sdata;
1258
1259 // Parse PD-exclude
1260 bool ok = true;
1261 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1262 odata + olen, stype, slen, sdata) {
1263 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1264 continue;
1265
1266 uint8_t elen = sdata[0];
1267 if (elen > 64)
1268 elen = 64;
1269
1270 if (entry.length < 32 || elen <= entry.length) {
1271 ok = false;
1272 continue;
1273 }
1274
1275 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1276 if (slen <= bytes) {
1277 ok = false;
1278 continue;
1279 }
1280
1281 uint32_t exclude = 0;
1282 do {
1283 exclude = exclude << 8 | sdata[bytes];
1284 } while (--bytes);
1285
1286 exclude >>= 8 - ((elen - entry.length) % 8);
1287 exclude <<= 64 - elen;
1288
1289 // Abusing router & priority fields for exclusion
1290 entry.router = entry.target;
1291 entry.router.s6_addr32[1] |= htonl(exclude);
1292 entry.priority = elen;
1293 }
1294
1295 if (ok) {
1296 if (odhcp6c_update_entry(STATE_IA_PD, &entry, 0, 0))
1297 updated_IAs++;
1298 }
1299
1300 entry.priority = 0;
1301 memset(&entry.router, 0, sizeof(entry.router));
1302 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1303 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1304 if (olen + 4U < sizeof(*addr))
1305 continue;
1306
1307 entry.preferred = ntohl(addr->preferred);
1308 entry.valid = ntohl(addr->valid);
1309
1310 if (entry.preferred > entry.valid)
1311 continue;
1312
1313 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1314 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1315 if (entry.t1 > entry.t2)
1316 entry.t1 = entry.t2;
1317
1318 entry.length = 128;
1319 entry.target = addr->addr;
1320
1321 if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0))
1322 updated_IAs++;
1323 }
1324 }
1325 return updated_IAs;
1326 }
1327
1328 static int dhcpv6_calc_refresh_timers(void)
1329 {
1330 struct odhcp6c_entry *e;
1331 size_t ia_na_entries, ia_pd_entries, i;
1332 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1333
1334 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1335 ia_na_entries /= sizeof(*e);
1336
1337 for (i = 0; i < ia_na_entries; i++) {
1338 if (e[i].t1 < l_t1)
1339 l_t1 = e[i].t1;
1340
1341 if (e[i].t2 < l_t2)
1342 l_t2 = e[i].t2;
1343
1344 if (e[i].valid > l_t3)
1345 l_t3 = e[i].valid;
1346 }
1347
1348 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1349 ia_pd_entries /= sizeof(*e);
1350
1351 for (i = 0; i < ia_pd_entries; i++) {
1352 if (e[i].t1 < l_t1)
1353 l_t1 = e[i].t1;
1354
1355 if (e[i].t2 < l_t2)
1356 l_t2 = e[i].t2;
1357
1358 if (e[i].valid > l_t3)
1359 l_t3 = e[i].valid;
1360 }
1361
1362 if (ia_pd_entries || ia_na_entries) {
1363 t1 = l_t1;
1364 t2 = l_t2;
1365 t3 = l_t3;
1366 }
1367
1368 return (int)(ia_pd_entries + ia_na_entries);
1369 }
1370
1371 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1372 const void *status_msg, int len)
1373 {
1374 const char *src = status_msg;
1375 char buf[len + 3];
1376 char *dst = buf;
1377
1378 if (len) {
1379 *dst++ = '(';
1380 while (len--) {
1381 *dst = isprint((unsigned char)*src) ? *src : '?';
1382 src++;
1383 dst++;
1384 }
1385 *dst++ = ')';
1386 }
1387
1388 *dst = 0;
1389
1390 syslog(LOG_WARNING, "Server returned %s status %i %s",
1391 scope, code, buf);
1392 }
1393
1394 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1395 const uint16_t code, const void *status_msg, const int len,
1396 int *ret)
1397 {
1398 dhcpv6_log_status_code(code, "message", status_msg, len);
1399
1400 switch (code) {
1401 case DHCPV6_UnspecFail:
1402 // Generic failure
1403 *ret = 0;
1404 break;
1405
1406 case DHCPV6_UseMulticast:
1407 switch(orig) {
1408 case DHCPV6_MSG_REQUEST:
1409 case DHCPV6_MSG_RENEW:
1410 case DHCPV6_MSG_RELEASE:
1411 case DHCPV6_MSG_DECLINE:
1412 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1413 server_addr = in6addr_any;
1414 *ret = 0;
1415 break;
1416 default:
1417 break;
1418 }
1419 break;
1420
1421 case DHCPV6_NoAddrsAvail:
1422 case DHCPV6_NoPrefixAvail:
1423 if (orig == DHCPV6_MSG_REQUEST)
1424 *ret = 0; // Failure
1425 break;
1426
1427 default:
1428 break;
1429 }
1430 }
1431
1432 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1433 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1434 const void *status_msg, const int len,
1435 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1436 {
1437 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1438 "IA_NA" : "IA_PD", status_msg, len);
1439
1440 switch (code) {
1441 case DHCPV6_NoBinding:
1442 switch (orig) {
1443 case DHCPV6_MSG_RENEW:
1444 case DHCPV6_MSG_REBIND:
1445 if ((*ret > 0) && !handled_status_codes[code])
1446 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1447 break;
1448
1449 default:
1450 break;
1451 }
1452 break;
1453
1454 default:
1455 *ret = 0;
1456 break;
1457 }
1458 }
1459
1460 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1461 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1462 {
1463 size_t cand_len, i;
1464 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1465
1466 // Remove identical duid server candidate
1467 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1468 if (cand->duid_len == c[i].duid_len &&
1469 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1470 free(c[i].ia_na);
1471 free(c[i].ia_pd);
1472 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1473 break;
1474 }
1475 }
1476
1477 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1478 i < cand_len / sizeof(*c); ++i) {
1479 if (c[i].preference < cand->preference)
1480 break;
1481 }
1482
1483 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1484 free(cand->ia_na);
1485 free(cand->ia_pd);
1486 }
1487 }
1488
1489 static void dhcpv6_clear_all_server_cand(void)
1490 {
1491 size_t cand_len, i;
1492 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1493
1494 // Server candidates need deep delete for IA_NA/IA_PD
1495 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1496 free(c[i].ia_na);
1497 free(c[i].ia_pd);
1498 }
1499 odhcp6c_clear_state(STATE_SERVER_CAND);
1500 }
1501
1502 int dhcpv6_promote_server_cand(void)
1503 {
1504 size_t cand_len;
1505 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1506 uint16_t hdr[2];
1507 int ret = DHCPV6_STATELESS;
1508
1509 // Clear lingering candidate state info
1510 odhcp6c_clear_state(STATE_SERVER_ID);
1511 odhcp6c_clear_state(STATE_IA_NA);
1512 odhcp6c_clear_state(STATE_IA_PD);
1513
1514 if (!cand_len)
1515 return -1;
1516
1517 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1518 na_mode = IA_MODE_NONE;
1519
1520 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1521 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1522
1523 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1524 }
1525
1526 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1527 hdr[1] = htons(cand->duid_len);
1528 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1529 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1530 accept_reconfig = cand->wants_reconfigure;
1531
1532 if (cand->ia_na_len) {
1533 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1534 free(cand->ia_na);
1535 if (na_mode != IA_MODE_NONE)
1536 ret = DHCPV6_STATEFUL;
1537 }
1538
1539 if (cand->ia_pd_len) {
1540 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1541 free(cand->ia_pd);
1542 if (pd_mode != IA_MODE_NONE)
1543 ret = DHCPV6_STATEFUL;
1544 }
1545
1546 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1547 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1548
1549 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1550
1551 return ret;
1552 }
Openwrt DHCPv6 Client