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odhcp6c: add option to ignore Server Unicast option
[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 int request_prefix = -1;
107 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
108 static bool accept_reconfig = false;
109 // Server unicast address
110 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
111
112 // Reconfigure key
113 static uint8_t reconf_key[16];
114
115 // client options
116 static unsigned int client_options = 0;
117
118 static uint32_t ntohl_unaligned(const uint8_t *data)
119 {
120 uint32_t buf;
121
122 memcpy(&buf, data, sizeof(buf));
123 return ntohl(buf);
124 }
125
126 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
127 {
128 client_options = options;
129 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
130
131 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
132 if (sock < 0)
133 goto failure;
134
135 // Detect interface
136 struct ifreq ifr;
137 memset(&ifr, 0, sizeof(ifr));
138 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
139 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
140 goto failure;
141
142 ifindex = ifr.ifr_ifindex;
143
144 // Create client DUID
145 size_t client_id_len;
146 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
147 if (client_id_len == 0) {
148 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
149 DHCPV6_DUID_LLADDR, 0, 1};
150
151 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
152 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
153
154 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
155 struct ifreq ifs[100], *ifp, *ifend;
156 struct ifconf ifc;
157 ifc.ifc_req = ifs;
158 ifc.ifc_len = sizeof(ifs);
159
160 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
161 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
162 // If our interface doesn't have an address...
163 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
164 for (ifp = ifc.ifc_req; ifp < ifend &&
165 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
166 memcpy(ifr.ifr_name, ifp->ifr_name,
167 sizeof(ifr.ifr_name));
168 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
169 continue;
170
171 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
172 ETHER_ADDR_LEN);
173 }
174 }
175
176 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
177 }
178
179 // Create ORO
180 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
181 uint16_t oro[] = {
182 htons(DHCPV6_OPT_SIP_SERVER_D),
183 htons(DHCPV6_OPT_SIP_SERVER_A),
184 htons(DHCPV6_OPT_DNS_SERVERS),
185 htons(DHCPV6_OPT_DNS_DOMAIN),
186 htons(DHCPV6_OPT_SNTP_SERVERS),
187 htons(DHCPV6_OPT_NTP_SERVER),
188 htons(DHCPV6_OPT_AFTR_NAME),
189 htons(DHCPV6_OPT_PD_EXCLUDE),
190 htons(DHCPV6_OPT_SOL_MAX_RT),
191 htons(DHCPV6_OPT_INF_MAX_RT),
192 #ifdef EXT_CER_ID
193 htons(DHCPV6_OPT_CER_ID),
194 #endif
195 htons(DHCPV6_OPT_S46_CONT_MAPE),
196 htons(DHCPV6_OPT_S46_CONT_MAPT),
197 htons(DHCPV6_OPT_S46_CONT_LW),
198 };
199 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
200
201 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST)) {
202 uint16_t otype = htons(DHCPV6_OPT_UNICAST);
203
204 odhcp6c_add_state(STATE_ORO, &otype, sizeof(otype));
205 }
206 }
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_ORO_REFRESH,
241 IOV_CL_ID,
242 IOV_SRV_ID,
243 IOV_OPTS,
244 IOV_RECONF_ACCEPT,
245 IOV_FQDN,
246 IOV_HDR_IA_NA,
247 IOV_IA_NA,
248 IOV_IA_PD,
249 IOV_TOTAL
250 };
251
252 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
253 {
254 int mode = DHCPV6_UNKNOWN;
255
256 na_mode = na;
257 pd_mode = pd;
258
259 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
260 mode = DHCPV6_STATELESS;
261 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
262 mode = DHCPV6_STATEFUL;
263
264 return mode;
265 }
266
267 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
268 {
269 // Build FQDN
270 char fqdn_buf[256];
271 gethostname(fqdn_buf, sizeof(fqdn_buf));
272 struct {
273 uint16_t type;
274 uint16_t len;
275 uint8_t flags;
276 uint8_t data[256];
277 } fqdn;
278 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
279 sizeof(fqdn.data), NULL, NULL);
280 fqdn.type = htons(DHCPV6_OPT_FQDN);
281 fqdn.len = htons(fqdn_len - 4);
282 fqdn.flags = 0;
283
284 // Build Client ID
285 size_t cl_id_len;
286 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
287
288 // Get Server ID
289 size_t srv_id_len;
290 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
291
292 // Build IA_PDs
293 size_t ia_pd_entries = 0, ia_pd_len = 0;
294 uint8_t *ia_pd;
295
296 if (type == DHCPV6_MSG_SOLICIT) {
297 odhcp6c_clear_state(STATE_IA_PD);
298 size_t n_prefixes;
299 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
300 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
301
302 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
303
304 for (size_t i = 0; i < n_prefixes; i++) {
305 struct dhcpv6_ia_hdr hdr_ia_pd = {
306 htons(DHCPV6_OPT_IA_PD),
307 htons(sizeof(hdr_ia_pd) - 4 +
308 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
309 request_prefixes[i].iaid, 0, 0
310 };
311 struct dhcpv6_ia_prefix pref = {
312 .type = htons(DHCPV6_OPT_IA_PREFIX),
313 .len = htons(sizeof(pref) - 4),
314 .prefix = request_prefixes[i].length
315 };
316 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
317 ia_pd_len += sizeof(hdr_ia_pd);
318 if (request_prefixes[i].length) {
319 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
320 ia_pd_len += sizeof(pref);
321 }
322 }
323 } else {
324 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
325 ia_pd_entries /= sizeof(*e);
326
327 // we're too lazy to count our distinct IAIDs,
328 // so just allocate maximally needed space
329 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
330 sizeof(struct dhcpv6_ia_hdr)));
331
332 for (size_t i = 0; i < ia_pd_entries; ++i) {
333 uint32_t iaid = e[i].iaid;
334
335 // check if this is an unprocessed IAID and skip if not.
336 int new_iaid = 1;
337 for (int j = i-1; j >= 0; j--) {
338 if (e[j].iaid == iaid) {
339 new_iaid = 0;
340 break;
341 }
342 }
343
344 if (!new_iaid)
345 continue;
346
347 // construct header
348 struct dhcpv6_ia_hdr hdr_ia_pd = {
349 htons(DHCPV6_OPT_IA_PD),
350 htons(sizeof(hdr_ia_pd) - 4),
351 iaid, 0, 0
352 };
353
354 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
355 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
356 ia_pd_len += sizeof(hdr_ia_pd);
357
358 for (size_t j = i; j < ia_pd_entries; j++) {
359 if (e[j].iaid != iaid)
360 continue;
361
362 uint8_t ex_len = 0;
363 if (e[j].priority > 0)
364 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
365
366 struct dhcpv6_ia_prefix p = {
367 .type = htons(DHCPV6_OPT_IA_PREFIX),
368 .len = htons(sizeof(p) - 4U + ex_len),
369 .prefix = e[j].length,
370 .addr = e[j].target
371 };
372
373 if (type == DHCPV6_MSG_REQUEST) {
374 p.preferred = htonl(e[j].preferred);
375 p.valid = htonl(e[j].valid);
376 }
377
378 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
379 ia_pd_len += sizeof(p);
380
381 if (ex_len) {
382 ia_pd[ia_pd_len++] = 0;
383 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
384 ia_pd[ia_pd_len++] = 0;
385 ia_pd[ia_pd_len++] = ex_len - 4;
386 ia_pd[ia_pd_len++] = e[j].priority;
387
388 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
389 excl >>= (64 - e[j].priority);
390 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
391
392 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
393 ia_pd[ia_pd_len + i] = excl & 0xff;
394 ia_pd_len += ex_len - 5;
395 }
396
397 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
398 }
399 }
400 }
401
402 if (ia_pd_entries > 0)
403 request_prefix = 1;
404
405 // Build IA_NAs
406 size_t ia_na_entries, ia_na_len = 0;
407 void *ia_na = NULL;
408 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
409 ia_na_entries /= sizeof(*e);
410
411 struct dhcpv6_ia_hdr hdr_ia_na = {
412 htons(DHCPV6_OPT_IA_NA),
413 htons(sizeof(hdr_ia_na) - 4),
414 htonl(1), 0, 0
415 };
416
417 struct dhcpv6_ia_addr pa[ia_na_entries];
418 for (size_t i = 0; i < ia_na_entries; ++i) {
419 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
420 pa[i].len = htons(sizeof(pa[i]) - 4U);
421 pa[i].addr = e[i].target;
422
423 if (type == DHCPV6_MSG_REQUEST) {
424 pa[i].preferred = htonl(e[i].preferred);
425 pa[i].valid = htonl(e[i].valid);
426 } else {
427 pa[i].preferred = 0;
428 pa[i].valid = 0;
429 }
430 }
431
432 ia_na = pa;
433 ia_na_len = sizeof(pa);
434 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
435
436 // Reconfigure Accept
437 struct {
438 uint16_t type;
439 uint16_t length;
440 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
441
442 // Request Information Refresh
443 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
444
445 // Option list
446 size_t opts_len;
447 void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len);
448
449 // Prepare Header
450 size_t oro_len;
451 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
452 struct {
453 uint8_t type;
454 uint8_t trid[3];
455 uint16_t elapsed_type;
456 uint16_t elapsed_len;
457 uint16_t elapsed_value;
458 uint16_t oro_type;
459 uint16_t oro_len;
460 } hdr = {
461 type, {trid[0], trid[1], trid[2]},
462 htons(DHCPV6_OPT_ELAPSED), htons(2),
463 htons((ecs > 0xffff) ? 0xffff : ecs),
464 htons(DHCPV6_OPT_ORO), htons(oro_len),
465 };
466
467 struct iovec iov[IOV_TOTAL] = {
468 [IOV_HDR] = {&hdr, sizeof(hdr)},
469 [IOV_ORO] = {oro, oro_len},
470 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
471 [IOV_CL_ID] = {cl_id, cl_id_len},
472 [IOV_SRV_ID] = {srv_id, srv_id_len},
473 [IOV_OPTS] = { opts, opts_len },
474 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
475 [IOV_FQDN] = {&fqdn, fqdn_len},
476 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
477 [IOV_IA_NA] = {ia_na, ia_na_len},
478 [IOV_IA_PD] = {ia_pd, ia_pd_len},
479 };
480
481 size_t cnt = IOV_TOTAL;
482 if (type == DHCPV6_MSG_INFO_REQ) {
483 cnt = 9;
484 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
485 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
486 } else if (!request_prefix)
487 cnt = 13;
488
489 // Disable IAs if not used
490 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
491 iov[IOV_HDR_IA_NA].iov_len = 0;
492
493 if (na_mode == IA_MODE_NONE)
494 iov[IOV_HDR_IA_NA].iov_len = 0;
495
496 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
497 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
498 iov[IOV_RECONF_ACCEPT].iov_len = 0;
499
500 if (!(client_options & DHCPV6_CLIENT_FQDN))
501 iov[IOV_FQDN].iov_len = 0;
502
503 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
504 0, ALL_DHCPV6_RELAYS, ifindex};
505 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
506 .msg_iov = iov, .msg_iovlen = cnt};
507
508 switch (type) {
509 case DHCPV6_MSG_REQUEST:
510 case DHCPV6_MSG_RENEW:
511 case DHCPV6_MSG_RELEASE:
512 case DHCPV6_MSG_DECLINE:
513 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
514 odhcp6c_addr_in_scope(&server_addr)) {
515 srv.sin6_addr = server_addr;
516 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
517 srv.sin6_scope_id = 0;
518 }
519 break;
520 default:
521 break;
522 }
523
524 if (sendmsg(sock, &msg, 0) < 0) {
525 char in6_str[INET6_ADDRSTRLEN];
526
527 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
528 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
529 in6_str, sizeof(in6_str)), strerror(errno));
530 }
531 }
532
533 static int64_t dhcpv6_rand_delay(int64_t time)
534 {
535 int random;
536 odhcp6c_random(&random, sizeof(random));
537
538 return (time * ((int64_t)random % 1000LL)) / 10000LL;
539 }
540
541 int dhcpv6_request(enum dhcpv6_msg type)
542 {
543 uint8_t rc = 0;
544 uint64_t timeout = UINT32_MAX;
545 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
546
547 if (retx->delay) {
548 struct timespec ts = {0, 0};
549 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
550
551 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
552 }
553
554 if (type == DHCPV6_MSG_UNKNOWN)
555 timeout = t1;
556 else if (type == DHCPV6_MSG_RENEW)
557 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
558 else if (type == DHCPV6_MSG_REBIND)
559 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
560
561 if (timeout == 0)
562 return -1;
563
564 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
565 retx->name, timeout, retx->max_rc);
566
567 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
568
569 // Generate transaction ID
570 uint8_t trid[3] = {0, 0, 0};
571 if (type != DHCPV6_MSG_UNKNOWN)
572 odhcp6c_random(trid, sizeof(trid));
573
574 ssize_t len = -1;
575 int64_t rto = 0;
576
577 do {
578 if (rto == 0) {
579 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
580
581 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
582 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
583 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
584
585 rto = (retx->init_timeo * 1000 + delay);
586 } else
587 rto = (2 * rto + dhcpv6_rand_delay(rto));
588
589 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
590 rto = retx->max_timeo * 1000 +
591 dhcpv6_rand_delay(retx->max_timeo * 1000);
592
593 // Calculate end for this round and elapsed time
594 uint64_t round_end = round_start + rto;
595 elapsed = round_start - start;
596
597 // Don't wait too long if timeout differs from infinite
598 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
599 round_end = timeout * 1000 + start;
600
601 // Built and send package
602 switch (type) {
603 case DHCPV6_MSG_UNKNOWN:
604 break;
605 default:
606 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
607 retx->name, elapsed, rc);
608 // Fall through
609 case DHCPV6_MSG_SOLICIT:
610 case DHCPV6_MSG_INFO_REQ:
611 dhcpv6_send(type, trid, elapsed / 10);
612 rc++;
613 }
614
615 // Receive rounds
616 for (; len < 0 && (round_start < round_end);
617 round_start = odhcp6c_get_milli_time()) {
618 uint8_t buf[1536];
619 union {
620 struct cmsghdr hdr;
621 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
622 } cmsg_buf;
623 struct iovec iov = {buf, sizeof(buf)};
624 struct sockaddr_in6 addr;
625 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
626 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
627 .msg_controllen = sizeof(cmsg_buf)};
628 struct in6_pktinfo *pktinfo = NULL;
629
630 // Check for pending signal
631 if (odhcp6c_signal_process())
632 return -1;
633
634 // Set timeout for receiving
635 uint64_t t = round_end - round_start;
636 struct timeval tv = {t / 1000, (t % 1000) * 1000};
637 if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
638 &tv, sizeof(tv)) < 0)
639 syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)",
640 strerror(errno));
641
642 // Receive cycle
643 len = recvmsg(sock, &msg, 0);
644 if (len < 0)
645 continue;
646
647 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
648 ch = CMSG_NXTHDR(&msg, ch)) {
649 if (ch->cmsg_level == SOL_IPV6 &&
650 ch->cmsg_type == IPV6_PKTINFO) {
651 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
652 break;
653 }
654 }
655
656 if (pktinfo == NULL) {
657 len = -1;
658 continue;
659 }
660
661 if (!dhcpv6_response_is_valid(buf, len, trid,
662 type, &pktinfo->ipi6_addr)) {
663 len = -1;
664 continue;
665 }
666
667 uint8_t *opt = &buf[4];
668 uint8_t *opt_end = opt + len - 4;
669
670 round_start = odhcp6c_get_milli_time();
671 elapsed = round_start - start;
672 syslog(LOG_NOTICE, "Got a valid reply after %"PRIu64"ms",
673 elapsed);
674
675 if (retx->handler_reply)
676 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
677
678 if (len > 0 && round_end - round_start > 1000)
679 round_end = 1000 + round_start;
680 }
681
682 // Allow
683 if (retx->handler_finish)
684 len = retx->handler_finish();
685 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
686 (!retx->max_rc || rc < retx->max_rc));
687 return len;
688 }
689
690 // Message validation checks according to RFC3315 chapter 15
691 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
692 const uint8_t transaction[3], enum dhcpv6_msg type,
693 const struct in6_addr *daddr)
694 {
695 const struct dhcpv6_header *rep = buf;
696 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
697 transaction, sizeof(rep->tr_id)))
698 return false; // Invalid reply
699
700 if (type == DHCPV6_MSG_SOLICIT) {
701 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
702 rep->msg_type != DHCPV6_MSG_REPLY)
703 return false;
704
705 } else if (type == DHCPV6_MSG_UNKNOWN) {
706 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
707 return false;
708
709 } else if (rep->msg_type != DHCPV6_MSG_REPLY)
710 return false;
711
712 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
713 rcmsg = DHCPV6_MSG_UNKNOWN;
714 uint16_t otype, olen = UINT16_MAX;
715 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
716 ia_present = false, options_valid = true;
717
718 size_t client_id_len, server_id_len;
719 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
720 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
721
722 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
723 if (otype == DHCPV6_OPT_CLIENTID) {
724 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
725 &odata[-4], client_id, client_id_len);
726 } else if (otype == DHCPV6_OPT_SERVERID) {
727 if (server_id_len)
728 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
729 &odata[-4], server_id, server_id_len);
730 else
731 serverid_ok = true;
732 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
733 sizeof(struct dhcpv6_auth_reconfigure)) {
734 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
735 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
736 continue;
737
738 md5_ctx_t md5;
739 uint8_t serverhash[16], secretbytes[64];
740 uint32_t hash[4];
741 memcpy(serverhash, r->key, sizeof(serverhash));
742 memset(r->key, 0, sizeof(r->key));
743
744 memset(secretbytes, 0, sizeof(secretbytes));
745 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
746
747 for (size_t i = 0; i < sizeof(secretbytes); ++i)
748 secretbytes[i] ^= 0x36;
749
750 md5_begin(&md5);
751 md5_hash(secretbytes, sizeof(secretbytes), &md5);
752 md5_hash(buf, len, &md5);
753 md5_end(hash, &md5);
754
755 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
756 secretbytes[i] ^= 0x36;
757 secretbytes[i] ^= 0x5c;
758 }
759
760 md5_begin(&md5);
761 md5_hash(secretbytes, sizeof(secretbytes), &md5);
762 md5_hash(hash, 16, &md5);
763 md5_end(hash, &md5);
764
765 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
766 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
767 rcmsg = odata[0];
768 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
769 ia_present = true;
770 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
771 options_valid = false;
772 } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
773 (otype == DHCPV6_OPT_PD_EXCLUDE))
774 // Options are not allowed on global level
775 options_valid = false;
776 }
777
778 if (!options_valid || ((odata + olen) > end))
779 return false;
780
781 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
782 return false;
783
784 if (rep->msg_type == DHCPV6_MSG_RECONF) {
785 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) ||
786 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
787 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
788 return false;
789 }
790
791 return clientid_ok && serverid_ok;
792 }
793
794 int dhcpv6_poll_reconfigure(void)
795 {
796 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
797
798 if (ret != -1)
799 ret = dhcpv6_request(ret);
800
801 return ret;
802 }
803
804 static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc,
805 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
806 {
807 uint16_t otype, olen;
808 uint8_t *odata;
809 int msg = -1;
810
811 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
812 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
813 switch (odata[0]) {
814 case DHCPV6_MSG_REBIND:
815 if (t2 != UINT32_MAX)
816 t2 = 0;
817 // Fall through
818 case DHCPV6_MSG_RENEW:
819 if (t1 != UINT32_MAX)
820 t1 = 0;
821 // Fall through
822 case DHCPV6_MSG_INFO_REQ:
823 msg = odata[0];
824 break;
825
826 default:
827 break;
828 }
829 }
830 }
831
832 dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL);
833
834 return msg;
835 }
836
837 // Collect all advertised servers
838 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
839 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
840 {
841 uint16_t olen, otype;
842 uint8_t *odata, pref = 0;
843 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
844 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
845 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
846 bool have_na = false;
847 int have_pd = 0;
848
849 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
850 if (orig == DHCPV6_MSG_SOLICIT &&
851 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
852 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
853 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
854 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
855 }
856
857 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
858 memcpy(cand.duid, odata, olen);
859 cand.duid_len = olen;
860 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
861 cand.preference >= 0) {
862 cand.preference = pref = odata[0];
863 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
864 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
865 cand.server_addr = *(struct in6_addr *)odata;
866
867 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
868 cand.wants_reconfigure = true;
869 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
870 uint32_t sol_max_rt = ntohl_unaligned(odata);
871 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
872 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
873 cand.sol_max_rt = sol_max_rt;
874
875 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
876 uint32_t inf_max_rt = ntohl_unaligned(odata);
877 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
878 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
879 cand.inf_max_rt = inf_max_rt;
880
881 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix &&
882 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
883 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
884 uint8_t *oend = odata + olen, *d;
885 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
886 if (otype == DHCPV6_OPT_IA_PREFIX &&
887 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
888 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
889 have_pd = p->prefix;
890 }
891 }
892 } else if (otype == DHCPV6_OPT_IA_NA &&
893 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
894 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
895 uint8_t *oend = odata + olen, *d;
896
897 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
898 if (otype == DHCPV6_OPT_IA_ADDR &&
899 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
900 have_na = true;
901 }
902 }
903 }
904
905 if ((!have_na && na_mode == IA_MODE_FORCE) ||
906 (!have_pd && pd_mode == IA_MODE_FORCE)) {
907 /*
908 * RFC7083 states to process the SOL_MAX_RT and
909 * INF_MAX_RT options even if the DHCPv6 server
910 * did not propose any IA_NA and/or IA_PD
911 */
912 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
913 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
914 return -1;
915 }
916
917 if (na_mode != IA_MODE_NONE && !have_na) {
918 cand.has_noaddravail = true;
919 cand.preference -= 1000;
920 }
921
922 if (pd_mode != IA_MODE_NONE) {
923 if (have_pd)
924 cand.preference += 2000 + (128 - have_pd);
925 else
926 cand.preference -= 2000;
927 }
928
929 if (cand.duid_len > 0) {
930 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
931 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
932 dhcpv6_add_server_cand(&cand);
933 }
934
935 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
936 }
937
938 static int dhcpv6_commit_advert(void)
939 {
940 return dhcpv6_promote_server_cand();
941 }
942
943 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
944 const void *opt, const void *end, const struct sockaddr_in6 *from)
945 {
946 dhcpv6_handle_advert(orig, rc, opt, end, from);
947 if (dhcpv6_commit_advert() < 0)
948 return -1;
949
950 return dhcpv6_handle_reply(orig, rc, opt, end, from);
951 }
952
953 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
954 const void *opt, const void *end, const struct sockaddr_in6 *from)
955 {
956 uint8_t *odata;
957 uint16_t otype, olen;
958 uint32_t refresh = 86400;
959 int ret = 1;
960 unsigned int updated_IAs = 0;
961 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
962
963 odhcp6c_expire();
964
965 if (orig == DHCPV6_MSG_UNKNOWN) {
966 static time_t last_update = 0;
967 time_t now = odhcp6c_get_milli_time() / 1000;
968
969 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
970 last_update = now;
971
972 if (t1 != UINT32_MAX)
973 t1 -= elapsed;
974
975 if (t2 != UINT32_MAX)
976 t2 -= elapsed;
977
978 if (t3 != UINT32_MAX)
979 t3 -= elapsed;
980
981 if (t1 < 0)
982 t1 = 0;
983
984 if (t2 < 0)
985 t2 = 0;
986
987 if (t3 < 0)
988 t3 = 0;
989 }
990
991 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
992 // Delete NA and PD we have in the state from the Advert
993 odhcp6c_clear_state(STATE_IA_NA);
994 odhcp6c_clear_state(STATE_IA_PD);
995 }
996
997 if (opt) {
998 odhcp6c_clear_state(STATE_DNS);
999 odhcp6c_clear_state(STATE_SEARCH);
1000 odhcp6c_clear_state(STATE_SNTP_IP);
1001 odhcp6c_clear_state(STATE_NTP_IP);
1002 odhcp6c_clear_state(STATE_NTP_FQDN);
1003 odhcp6c_clear_state(STATE_SIP_IP);
1004 odhcp6c_clear_state(STATE_SIP_FQDN);
1005 odhcp6c_clear_state(STATE_AFTR_NAME);
1006 odhcp6c_clear_state(STATE_CER);
1007 odhcp6c_clear_state(STATE_S46_MAPT);
1008 odhcp6c_clear_state(STATE_S46_MAPE);
1009 odhcp6c_clear_state(STATE_S46_LW);
1010 odhcp6c_clear_state(STATE_PASSTHRU);
1011 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
1012
1013 // Parse and find all matching IAs
1014 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
1015 struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype);
1016
1017 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1018 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1019 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1020
1021 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1022 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1023 continue;
1024
1025 // Test ID
1026 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1027 continue;
1028
1029 uint16_t code = DHCPV6_Success;
1030 uint16_t stype, slen;
1031 uint8_t *sdata;
1032 // Get and handle status code
1033 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1034 stype, slen, sdata) {
1035 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1036 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1037 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1038
1039 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1040
1041 if (code == DHCPV6_Success)
1042 continue;
1043
1044 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1045 code, mdata, mlen, handled_status_codes, &ret);
1046
1047 if (ret > 0)
1048 return ret;
1049
1050 break;
1051 }
1052 }
1053
1054 if (code != DHCPV6_Success)
1055 continue;
1056
1057 updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen);
1058 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1059 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
1060 server_addr = *(struct in6_addr *)odata;
1061
1062 }
1063 else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1064 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1065 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1066 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1067
1068 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1069 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1070 if (olen % 16 == 0)
1071 odhcp6c_add_state(STATE_DNS, odata, olen);
1072 } else if (otype == DHCPV6_OPT_DNS_DOMAIN)
1073 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1074 else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1075 if (olen % 16 == 0)
1076 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1077 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1078 uint16_t stype, slen;
1079 uint8_t *sdata;
1080 // Test status and bail if error
1081 dhcpv6_for_each_option(odata, odata + olen,
1082 stype, slen, sdata) {
1083 if (slen == 16 && (stype == NTP_MC_ADDR ||
1084 stype == NTP_SRV_ADDR))
1085 odhcp6c_add_state(STATE_NTP_IP,
1086 sdata, slen);
1087 else if (slen > 0 && stype == NTP_SRV_FQDN)
1088 odhcp6c_add_state(STATE_NTP_FQDN,
1089 sdata, slen);
1090 }
1091 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1092 if (olen == 16)
1093 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1094 } else if (otype == DHCPV6_OPT_SIP_SERVER_D)
1095 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1096 else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1097 refresh = ntohl_unaligned(odata);
1098 } else if (otype == DHCPV6_OPT_AUTH) {
1099 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1100 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1101 if (r->protocol == 3 && r->algorithm == 1 &&
1102 r->reconf_type == 1)
1103 memcpy(reconf_key, r->key, sizeof(r->key));
1104 }
1105 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1106 size_t cur_len;
1107 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1108 if (cur_len == 0)
1109 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1110 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1111 uint32_t sol_max_rt = ntohl_unaligned(odata);
1112 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1113 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1114 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1115 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1116 uint32_t inf_max_rt = ntohl_unaligned(odata);
1117 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1118 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1119 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1120 #ifdef EXT_CER_ID
1121 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1122 sizeof(struct dhcpv6_cer_id)) {
1123 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1124 struct in6_addr any = IN6ADDR_ANY_INIT;
1125 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1126 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1127 #endif
1128 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1129 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1130 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1131 size_t mape_len;
1132 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1133 if (mape_len == 0)
1134 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1135 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1136 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1137 } else
1138 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1139
1140 if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU))
1141 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1142 }
1143 }
1144
1145 switch (orig) {
1146 case DHCPV6_MSG_REQUEST:
1147 case DHCPV6_MSG_REBIND:
1148 case DHCPV6_MSG_RENEW:
1149 // Update refresh timers if no fatal status code was received
1150 if ((ret > 0) && (ret = dhcpv6_calc_refresh_timers())) {
1151 if (orig == DHCPV6_MSG_REQUEST) {
1152 // All server candidates can be cleared if not yet bound
1153 if (!odhcp6c_is_bound())
1154 dhcpv6_clear_all_server_cand();
1155
1156 odhcp6c_clear_state(STATE_SERVER_ADDR);
1157 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1158 } else if (orig == DHCPV6_MSG_RENEW) {
1159 // Send further renews if T1 is not set and
1160 // no updated IAs
1161 if (!t1) {
1162 if (!updated_IAs)
1163 ret = -1;
1164 else if ((t2 - t1) > 1)
1165 // Grace period of 1 second
1166 t1 = 1;
1167 }
1168
1169 } else if (orig == DHCPV6_MSG_REBIND) {
1170 // Send further rebinds if T1 and T2 is not set and
1171 // no updated IAs
1172 if (!t1 && !t2) {
1173 if (!updated_IAs)
1174 ret = -1;
1175 else if ((t3 - t2) > 1)
1176 // Grace period of 1 second
1177 t2 = 1;
1178 }
1179
1180 odhcp6c_clear_state(STATE_SERVER_ADDR);
1181 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1182 }
1183 }
1184 break;
1185
1186 case DHCPV6_MSG_INFO_REQ:
1187 if (ret > 0) {
1188 // All server candidates can be cleared if not yet bound
1189 if (!odhcp6c_is_bound())
1190 dhcpv6_clear_all_server_cand();
1191
1192 t1 = refresh;
1193 }
1194 break;
1195
1196 default:
1197 break;
1198 }
1199
1200 return ret;
1201 }
1202
1203 static unsigned int dhcpv6_parse_ia(void *opt, void *end)
1204 {
1205 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1206 unsigned int updated_IAs = 0;
1207 uint32_t t1, t2;
1208 uint16_t otype, olen;
1209 uint8_t *odata;
1210
1211 t1 = ntohl(ia_hdr->t1);
1212 t2 = ntohl(ia_hdr->t2);
1213
1214 if (t1 > t2)
1215 return 0;
1216
1217 // Update address IA
1218 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1219 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1220 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1221
1222 entry.iaid = ia_hdr->iaid;
1223
1224 if (otype == DHCPV6_OPT_IA_PREFIX) {
1225 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1226 if (olen + 4U < sizeof(*prefix))
1227 continue;
1228
1229 entry.valid = ntohl(prefix->valid);
1230 entry.preferred = ntohl(prefix->preferred);
1231
1232 if (entry.preferred > entry.valid)
1233 continue;
1234
1235 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1236 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1237 if (entry.t1 > entry.t2)
1238 entry.t1 = entry.t2;
1239
1240 entry.length = prefix->prefix;
1241 entry.target = prefix->addr;
1242 uint16_t stype, slen;
1243 uint8_t *sdata;
1244
1245 // Parse PD-exclude
1246 bool ok = true;
1247 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1248 odata + olen, stype, slen, sdata) {
1249 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1250 continue;
1251
1252 uint8_t elen = sdata[0];
1253 if (elen > 64)
1254 elen = 64;
1255
1256 if (entry.length < 32 || elen <= entry.length) {
1257 ok = false;
1258 continue;
1259 }
1260
1261 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1262 if (slen <= bytes) {
1263 ok = false;
1264 continue;
1265 }
1266
1267 uint32_t exclude = 0;
1268 do {
1269 exclude = exclude << 8 | sdata[bytes];
1270 } while (--bytes);
1271
1272 exclude >>= 8 - ((elen - entry.length) % 8);
1273 exclude <<= 64 - elen;
1274
1275 // Abusing router & priority fields for exclusion
1276 entry.router = entry.target;
1277 entry.router.s6_addr32[1] |= htonl(exclude);
1278 entry.priority = elen;
1279 }
1280
1281 if (ok) {
1282 if (odhcp6c_update_entry(STATE_IA_PD, &entry, 0, 0))
1283 updated_IAs++;
1284 }
1285
1286 entry.priority = 0;
1287 memset(&entry.router, 0, sizeof(entry.router));
1288 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1289 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1290 if (olen + 4U < sizeof(*addr))
1291 continue;
1292
1293 entry.preferred = ntohl(addr->preferred);
1294 entry.valid = ntohl(addr->valid);
1295
1296 if (entry.preferred > entry.valid)
1297 continue;
1298
1299 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1300 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1301 if (entry.t1 > entry.t2)
1302 entry.t1 = entry.t2;
1303
1304 entry.length = 128;
1305 entry.target = addr->addr;
1306
1307 if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0))
1308 updated_IAs++;
1309 }
1310 }
1311 return updated_IAs;
1312 }
1313
1314 static int dhcpv6_calc_refresh_timers(void)
1315 {
1316 struct odhcp6c_entry *e;
1317 size_t ia_na_entries, ia_pd_entries, i;
1318 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1319
1320 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1321 ia_na_entries /= sizeof(*e);
1322
1323 for (i = 0; i < ia_na_entries; i++) {
1324 if (e[i].t1 < l_t1)
1325 l_t1 = e[i].t1;
1326
1327 if (e[i].t2 < l_t2)
1328 l_t2 = e[i].t2;
1329
1330 if (e[i].valid > l_t3)
1331 l_t3 = e[i].valid;
1332 }
1333
1334 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1335 ia_pd_entries /= sizeof(*e);
1336
1337 for (i = 0; i < ia_pd_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 if (ia_pd_entries || ia_na_entries) {
1349 t1 = l_t1;
1350 t2 = l_t2;
1351 t3 = l_t3;
1352 }
1353
1354 return (int)(ia_pd_entries + ia_na_entries);
1355 }
1356
1357 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1358 const void *status_msg, int len)
1359 {
1360 const char *src = status_msg;
1361 char buf[len + 3];
1362 char *dst = buf;
1363
1364 if (len) {
1365 *dst++ = '(';
1366 while (len--) {
1367 *dst = isprint((unsigned char)*src) ? *src : '?';
1368 src++;
1369 dst++;
1370 }
1371 *dst++ = ')';
1372 }
1373
1374 *dst = 0;
1375
1376 syslog(LOG_WARNING, "Server returned %s status %i %s",
1377 scope, code, buf);
1378 }
1379
1380 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1381 const uint16_t code, const void *status_msg, const int len,
1382 int *ret)
1383 {
1384 dhcpv6_log_status_code(code, "message", status_msg, len);
1385
1386 switch (code) {
1387 case DHCPV6_UnspecFail:
1388 // Generic failure
1389 *ret = 0;
1390 break;
1391
1392 case DHCPV6_UseMulticast:
1393 switch(orig) {
1394 case DHCPV6_MSG_REQUEST:
1395 case DHCPV6_MSG_RENEW:
1396 case DHCPV6_MSG_RELEASE:
1397 case DHCPV6_MSG_DECLINE:
1398 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1399 server_addr = in6addr_any;
1400 *ret = 0;
1401 break;
1402 default:
1403 break;
1404 }
1405 break;
1406
1407 case DHCPV6_NoAddrsAvail:
1408 case DHCPV6_NoPrefixAvail:
1409 if (orig == DHCPV6_MSG_REQUEST)
1410 *ret = 0; // Failure
1411 break;
1412
1413 default:
1414 break;
1415 }
1416 }
1417
1418 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1419 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1420 const void *status_msg, const int len,
1421 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1422 {
1423 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1424 "IA_NA" : "IA_PD", status_msg, len);
1425
1426 switch (code) {
1427 case DHCPV6_NoBinding:
1428 switch (orig) {
1429 case DHCPV6_MSG_RENEW:
1430 case DHCPV6_MSG_REBIND:
1431 if ((*ret > 0) && !handled_status_codes[code])
1432 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1433 break;
1434
1435 default:
1436 break;
1437 }
1438 break;
1439
1440 default:
1441 *ret = 0;
1442 break;
1443 }
1444 }
1445
1446 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1447 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1448 {
1449 size_t cand_len, i;
1450 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1451
1452 // Remove identical duid server candidate
1453 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1454 if (cand->duid_len == c[i].duid_len &&
1455 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1456 free(c[i].ia_na);
1457 free(c[i].ia_pd);
1458 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1459 break;
1460 }
1461 }
1462
1463 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1464 i < cand_len / sizeof(*c); ++i) {
1465 if (c[i].preference < cand->preference)
1466 break;
1467 }
1468
1469 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1470 free(cand->ia_na);
1471 free(cand->ia_pd);
1472 }
1473 }
1474
1475 static void dhcpv6_clear_all_server_cand(void)
1476 {
1477 size_t cand_len, i;
1478 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1479
1480 // Server candidates need deep delete for IA_NA/IA_PD
1481 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1482 free(c[i].ia_na);
1483 free(c[i].ia_pd);
1484 }
1485 odhcp6c_clear_state(STATE_SERVER_CAND);
1486 }
1487
1488 int dhcpv6_promote_server_cand(void)
1489 {
1490 size_t cand_len;
1491 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1492 uint16_t hdr[2];
1493 int ret = DHCPV6_STATELESS;
1494
1495 // Clear lingering candidate state info
1496 odhcp6c_clear_state(STATE_SERVER_ID);
1497 odhcp6c_clear_state(STATE_IA_NA);
1498 odhcp6c_clear_state(STATE_IA_PD);
1499
1500 if (!cand_len)
1501 return -1;
1502
1503 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1504 na_mode = IA_MODE_NONE;
1505
1506 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1507 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1508
1509 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1510 }
1511
1512 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1513 hdr[1] = htons(cand->duid_len);
1514 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1515 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1516 accept_reconfig = cand->wants_reconfigure;
1517
1518 if (cand->ia_na_len) {
1519 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1520 free(cand->ia_na);
1521 if (na_mode != IA_MODE_NONE)
1522 ret = DHCPV6_STATEFUL;
1523 }
1524
1525 if (cand->ia_pd_len) {
1526 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1527 free(cand->ia_pd);
1528 if (request_prefix)
1529 ret = DHCPV6_STATEFUL;
1530 }
1531
1532 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1533 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1534
1535 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1536
1537 return ret;
1538 }
Openwrt DHCPv6 Client