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dhcpv6: sanitize option request list
[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 // Required oro
202 uint16_t req_oro[] = {
203 htons(DHCPV6_OPT_INF_MAX_RT),
204 htons(DHCPV6_OPT_SOL_MAX_RT),
205 htons(DHCPV6_OPT_INFO_REFRESH),
206 };
207 odhcp6c_add_state(STATE_ORO, req_oro, sizeof(req_oro));
208
209 // Configure IPv6-options
210 int val = 1;
211 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
212 goto failure;
213
214 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
215 goto failure;
216
217 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
218 goto failure;
219
220 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
221 goto failure;
222
223 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
224 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
225
226 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
227 goto failure;
228
229 return 0;
230
231 failure:
232 if (sock >= 0)
233 close(sock);
234
235 return -1;
236 }
237
238 enum {
239 IOV_HDR=0,
240 IOV_ORO,
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 // Option list
443 size_t opts_len;
444 void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len);
445
446 // Option Request List
447 size_t oro_entries, oro_len = 0;
448 uint16_t *oro, *s_oro = odhcp6c_get_state(STATE_ORO, &oro_entries);
449
450 oro_entries /= sizeof(*s_oro);
451 oro = alloca(oro_entries * sizeof(*oro));
452
453 for (size_t i = 0; i < oro_entries; i++) {
454 struct odhcp6c_opt *opt = odhcp6c_find_opt(htons(s_oro[i]));
455
456 if (opt) {
457 if (!(opt->flags & OPT_ORO))
458 continue;
459
460 if ((opt->flags & OPT_ORO_SOLICIT) && type != DHCPV6_MSG_SOLICIT)
461 continue;
462
463 if ((opt->flags & OPT_ORO_STATELESS) && type != DHCPV6_MSG_INFO_REQ)
464 continue;
465
466 if ((opt->flags & OPT_ORO_STATEFUL) && type == DHCPV6_MSG_INFO_REQ)
467 continue;
468 }
469
470 oro[oro_len++] = s_oro[i];
471 }
472 oro_len *= sizeof(*oro);
473
474 // Prepare Header
475 struct {
476 uint8_t type;
477 uint8_t trid[3];
478 uint16_t elapsed_type;
479 uint16_t elapsed_len;
480 uint16_t elapsed_value;
481 uint16_t oro_type;
482 uint16_t oro_len;
483 } hdr = {
484 type, {trid[0], trid[1], trid[2]},
485 htons(DHCPV6_OPT_ELAPSED), htons(2),
486 htons((ecs > 0xffff) ? 0xffff : ecs),
487 htons(DHCPV6_OPT_ORO), htons(oro_len),
488 };
489
490 struct iovec iov[IOV_TOTAL] = {
491 [IOV_HDR] = {&hdr, sizeof(hdr)},
492 [IOV_ORO] = {oro, oro_len},
493 [IOV_CL_ID] = {cl_id, cl_id_len},
494 [IOV_SRV_ID] = {srv_id, srv_id_len},
495 [IOV_OPTS] = { opts, opts_len },
496 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
497 [IOV_FQDN] = {&fqdn, fqdn_len},
498 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
499 [IOV_IA_NA] = {ia_na, ia_na_len},
500 [IOV_IA_PD] = {ia_pd, ia_pd_len},
501 };
502
503 size_t cnt = IOV_TOTAL;
504 if (type == DHCPV6_MSG_INFO_REQ)
505 cnt = 8;
506 else if (!request_prefix)
507 cnt = 12;
508
509 // Disable IAs if not used
510 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
511 iov[IOV_HDR_IA_NA].iov_len = 0;
512
513 if (na_mode == IA_MODE_NONE)
514 iov[IOV_HDR_IA_NA].iov_len = 0;
515
516 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
517 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
518 iov[IOV_RECONF_ACCEPT].iov_len = 0;
519
520 if (!(client_options & DHCPV6_CLIENT_FQDN))
521 iov[IOV_FQDN].iov_len = 0;
522
523 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
524 0, ALL_DHCPV6_RELAYS, ifindex};
525 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
526 .msg_iov = iov, .msg_iovlen = cnt};
527
528 switch (type) {
529 case DHCPV6_MSG_REQUEST:
530 case DHCPV6_MSG_RENEW:
531 case DHCPV6_MSG_RELEASE:
532 case DHCPV6_MSG_DECLINE:
533 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
534 odhcp6c_addr_in_scope(&server_addr)) {
535 srv.sin6_addr = server_addr;
536 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
537 srv.sin6_scope_id = 0;
538 }
539 break;
540 default:
541 break;
542 }
543
544 if (sendmsg(sock, &msg, 0) < 0) {
545 char in6_str[INET6_ADDRSTRLEN];
546
547 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
548 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
549 in6_str, sizeof(in6_str)), strerror(errno));
550 }
551 }
552
553 static int64_t dhcpv6_rand_delay(int64_t time)
554 {
555 int random;
556 odhcp6c_random(&random, sizeof(random));
557
558 return (time * ((int64_t)random % 1000LL)) / 10000LL;
559 }
560
561 int dhcpv6_request(enum dhcpv6_msg type)
562 {
563 uint8_t rc = 0;
564 uint64_t timeout = UINT32_MAX;
565 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
566
567 if (retx->delay) {
568 struct timespec ts = {0, 0};
569 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
570
571 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
572 }
573
574 if (type == DHCPV6_MSG_UNKNOWN)
575 timeout = t1;
576 else if (type == DHCPV6_MSG_RENEW)
577 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
578 else if (type == DHCPV6_MSG_REBIND)
579 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
580
581 if (timeout == 0)
582 return -1;
583
584 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
585 retx->name, timeout, retx->max_rc);
586
587 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
588
589 // Generate transaction ID
590 uint8_t trid[3] = {0, 0, 0};
591 if (type != DHCPV6_MSG_UNKNOWN)
592 odhcp6c_random(trid, sizeof(trid));
593
594 ssize_t len = -1;
595 int64_t rto = 0;
596
597 do {
598 if (rto == 0) {
599 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
600
601 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
602 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
603 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
604
605 rto = (retx->init_timeo * 1000 + delay);
606 } else
607 rto = (2 * rto + dhcpv6_rand_delay(rto));
608
609 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
610 rto = retx->max_timeo * 1000 +
611 dhcpv6_rand_delay(retx->max_timeo * 1000);
612
613 // Calculate end for this round and elapsed time
614 uint64_t round_end = round_start + rto;
615 elapsed = round_start - start;
616
617 // Don't wait too long if timeout differs from infinite
618 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
619 round_end = timeout * 1000 + start;
620
621 // Built and send package
622 switch (type) {
623 case DHCPV6_MSG_UNKNOWN:
624 break;
625 default:
626 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
627 retx->name, elapsed, rc);
628 // Fall through
629 case DHCPV6_MSG_SOLICIT:
630 case DHCPV6_MSG_INFO_REQ:
631 dhcpv6_send(type, trid, elapsed / 10);
632 rc++;
633 }
634
635 // Receive rounds
636 for (; len < 0 && (round_start < round_end);
637 round_start = odhcp6c_get_milli_time()) {
638 uint8_t buf[1536];
639 union {
640 struct cmsghdr hdr;
641 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
642 } cmsg_buf;
643 struct iovec iov = {buf, sizeof(buf)};
644 struct sockaddr_in6 addr;
645 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
646 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
647 .msg_controllen = sizeof(cmsg_buf)};
648 struct in6_pktinfo *pktinfo = NULL;
649
650 // Check for pending signal
651 if (odhcp6c_signal_process())
652 return -1;
653
654 // Set timeout for receiving
655 uint64_t t = round_end - round_start;
656 struct timeval tv = {t / 1000, (t % 1000) * 1000};
657 if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
658 &tv, sizeof(tv)) < 0)
659 syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)",
660 strerror(errno));
661
662 // Receive cycle
663 len = recvmsg(sock, &msg, 0);
664 if (len < 0)
665 continue;
666
667 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
668 ch = CMSG_NXTHDR(&msg, ch)) {
669 if (ch->cmsg_level == SOL_IPV6 &&
670 ch->cmsg_type == IPV6_PKTINFO) {
671 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
672 break;
673 }
674 }
675
676 if (pktinfo == NULL) {
677 len = -1;
678 continue;
679 }
680
681 if (!dhcpv6_response_is_valid(buf, len, trid,
682 type, &pktinfo->ipi6_addr)) {
683 len = -1;
684 continue;
685 }
686
687 uint8_t *opt = &buf[4];
688 uint8_t *opt_end = opt + len - 4;
689
690 round_start = odhcp6c_get_milli_time();
691 elapsed = round_start - start;
692 syslog(LOG_NOTICE, "Got a valid reply after %"PRIu64"ms",
693 elapsed);
694
695 if (retx->handler_reply)
696 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
697
698 if (len > 0 && round_end - round_start > 1000)
699 round_end = 1000 + round_start;
700 }
701
702 // Allow
703 if (retx->handler_finish)
704 len = retx->handler_finish();
705 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
706 (!retx->max_rc || rc < retx->max_rc));
707 return len;
708 }
709
710 // Message validation checks according to RFC3315 chapter 15
711 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
712 const uint8_t transaction[3], enum dhcpv6_msg type,
713 const struct in6_addr *daddr)
714 {
715 const struct dhcpv6_header *rep = buf;
716 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
717 transaction, sizeof(rep->tr_id)))
718 return false; // Invalid reply
719
720 if (type == DHCPV6_MSG_SOLICIT) {
721 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
722 rep->msg_type != DHCPV6_MSG_REPLY)
723 return false;
724
725 } else if (type == DHCPV6_MSG_UNKNOWN) {
726 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
727 return false;
728
729 } else if (rep->msg_type != DHCPV6_MSG_REPLY)
730 return false;
731
732 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
733 rcmsg = DHCPV6_MSG_UNKNOWN;
734 uint16_t otype, olen = UINT16_MAX;
735 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
736 ia_present = false, options_valid = true;
737
738 size_t client_id_len, server_id_len;
739 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
740 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
741
742 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
743 if (otype == DHCPV6_OPT_CLIENTID) {
744 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
745 &odata[-4], client_id, client_id_len);
746 } else if (otype == DHCPV6_OPT_SERVERID) {
747 if (server_id_len)
748 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
749 &odata[-4], server_id, server_id_len);
750 else
751 serverid_ok = true;
752 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
753 sizeof(struct dhcpv6_auth_reconfigure)) {
754 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
755 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
756 continue;
757
758 md5_ctx_t md5;
759 uint8_t serverhash[16], secretbytes[64];
760 uint32_t hash[4];
761 memcpy(serverhash, r->key, sizeof(serverhash));
762 memset(r->key, 0, sizeof(r->key));
763
764 memset(secretbytes, 0, sizeof(secretbytes));
765 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
766
767 for (size_t i = 0; i < sizeof(secretbytes); ++i)
768 secretbytes[i] ^= 0x36;
769
770 md5_begin(&md5);
771 md5_hash(secretbytes, sizeof(secretbytes), &md5);
772 md5_hash(buf, len, &md5);
773 md5_end(hash, &md5);
774
775 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
776 secretbytes[i] ^= 0x36;
777 secretbytes[i] ^= 0x5c;
778 }
779
780 md5_begin(&md5);
781 md5_hash(secretbytes, sizeof(secretbytes), &md5);
782 md5_hash(hash, 16, &md5);
783 md5_end(hash, &md5);
784
785 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
786 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
787 rcmsg = odata[0];
788 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
789 ia_present = true;
790 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
791 options_valid = false;
792 } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
793 (otype == DHCPV6_OPT_PD_EXCLUDE))
794 // Options are not allowed on global level
795 options_valid = false;
796 }
797
798 if (!options_valid || ((odata + olen) > end))
799 return false;
800
801 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
802 return false;
803
804 if (rep->msg_type == DHCPV6_MSG_RECONF) {
805 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) ||
806 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
807 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
808 return false;
809 }
810
811 return clientid_ok && serverid_ok;
812 }
813
814 int dhcpv6_poll_reconfigure(void)
815 {
816 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
817
818 if (ret != -1)
819 ret = dhcpv6_request(ret);
820
821 return ret;
822 }
823
824 static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc,
825 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
826 {
827 uint16_t otype, olen;
828 uint8_t *odata;
829 int msg = -1;
830
831 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
832 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
833 switch (odata[0]) {
834 case DHCPV6_MSG_REBIND:
835 if (t2 != UINT32_MAX)
836 t2 = 0;
837 // Fall through
838 case DHCPV6_MSG_RENEW:
839 if (t1 != UINT32_MAX)
840 t1 = 0;
841 // Fall through
842 case DHCPV6_MSG_INFO_REQ:
843 msg = odata[0];
844 break;
845
846 default:
847 break;
848 }
849 }
850 }
851
852 dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL);
853
854 return msg;
855 }
856
857 // Collect all advertised servers
858 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
859 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
860 {
861 uint16_t olen, otype;
862 uint8_t *odata, pref = 0;
863 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
864 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
865 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
866 bool have_na = false;
867 int have_pd = 0;
868
869 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
870 if (orig == DHCPV6_MSG_SOLICIT &&
871 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
872 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
873 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
874 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
875 }
876
877 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
878 memcpy(cand.duid, odata, olen);
879 cand.duid_len = olen;
880 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
881 cand.preference >= 0) {
882 cand.preference = pref = odata[0];
883 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
884 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
885 cand.server_addr = *(struct in6_addr *)odata;
886
887 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
888 cand.wants_reconfigure = true;
889 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
890 uint32_t sol_max_rt = ntohl_unaligned(odata);
891 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
892 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
893 cand.sol_max_rt = sol_max_rt;
894
895 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
896 uint32_t inf_max_rt = ntohl_unaligned(odata);
897 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
898 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
899 cand.inf_max_rt = inf_max_rt;
900
901 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix &&
902 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
903 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
904 uint8_t *oend = odata + olen, *d;
905 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
906 if (otype == DHCPV6_OPT_IA_PREFIX &&
907 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
908 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
909 have_pd = p->prefix;
910 }
911 }
912 } else if (otype == DHCPV6_OPT_IA_NA &&
913 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
914 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
915 uint8_t *oend = odata + olen, *d;
916
917 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
918 if (otype == DHCPV6_OPT_IA_ADDR &&
919 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
920 have_na = true;
921 }
922 }
923 }
924
925 if ((!have_na && na_mode == IA_MODE_FORCE) ||
926 (!have_pd && pd_mode == IA_MODE_FORCE)) {
927 /*
928 * RFC7083 states to process the SOL_MAX_RT and
929 * INF_MAX_RT options even if the DHCPv6 server
930 * did not propose any IA_NA and/or IA_PD
931 */
932 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
933 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
934 return -1;
935 }
936
937 if (na_mode != IA_MODE_NONE && !have_na) {
938 cand.has_noaddravail = true;
939 cand.preference -= 1000;
940 }
941
942 if (pd_mode != IA_MODE_NONE) {
943 if (have_pd)
944 cand.preference += 2000 + (128 - have_pd);
945 else
946 cand.preference -= 2000;
947 }
948
949 if (cand.duid_len > 0) {
950 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
951 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
952 dhcpv6_add_server_cand(&cand);
953 }
954
955 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
956 }
957
958 static int dhcpv6_commit_advert(void)
959 {
960 return dhcpv6_promote_server_cand();
961 }
962
963 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
964 const void *opt, const void *end, const struct sockaddr_in6 *from)
965 {
966 dhcpv6_handle_advert(orig, rc, opt, end, from);
967 if (dhcpv6_commit_advert() < 0)
968 return -1;
969
970 return dhcpv6_handle_reply(orig, rc, opt, end, from);
971 }
972
973 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
974 const void *opt, const void *end, const struct sockaddr_in6 *from)
975 {
976 uint8_t *odata;
977 uint16_t otype, olen;
978 uint32_t refresh = 86400;
979 int ret = 1;
980 unsigned int updated_IAs = 0;
981 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
982
983 odhcp6c_expire();
984
985 if (orig == DHCPV6_MSG_UNKNOWN) {
986 static time_t last_update = 0;
987 time_t now = odhcp6c_get_milli_time() / 1000;
988
989 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
990 last_update = now;
991
992 if (t1 != UINT32_MAX)
993 t1 -= elapsed;
994
995 if (t2 != UINT32_MAX)
996 t2 -= elapsed;
997
998 if (t3 != UINT32_MAX)
999 t3 -= elapsed;
1000
1001 if (t1 < 0)
1002 t1 = 0;
1003
1004 if (t2 < 0)
1005 t2 = 0;
1006
1007 if (t3 < 0)
1008 t3 = 0;
1009 }
1010
1011 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
1012 // Delete NA and PD we have in the state from the Advert
1013 odhcp6c_clear_state(STATE_IA_NA);
1014 odhcp6c_clear_state(STATE_IA_PD);
1015 }
1016
1017 if (opt) {
1018 odhcp6c_clear_state(STATE_DNS);
1019 odhcp6c_clear_state(STATE_SEARCH);
1020 odhcp6c_clear_state(STATE_SNTP_IP);
1021 odhcp6c_clear_state(STATE_NTP_IP);
1022 odhcp6c_clear_state(STATE_NTP_FQDN);
1023 odhcp6c_clear_state(STATE_SIP_IP);
1024 odhcp6c_clear_state(STATE_SIP_FQDN);
1025 odhcp6c_clear_state(STATE_AFTR_NAME);
1026 odhcp6c_clear_state(STATE_CER);
1027 odhcp6c_clear_state(STATE_S46_MAPT);
1028 odhcp6c_clear_state(STATE_S46_MAPE);
1029 odhcp6c_clear_state(STATE_S46_LW);
1030 odhcp6c_clear_state(STATE_PASSTHRU);
1031 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
1032
1033 // Parse and find all matching IAs
1034 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
1035 struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype);
1036
1037 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1038 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1039 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1040
1041 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1042 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1043 continue;
1044
1045 // Test ID
1046 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1047 continue;
1048
1049 uint16_t code = DHCPV6_Success;
1050 uint16_t stype, slen;
1051 uint8_t *sdata;
1052 // Get and handle status code
1053 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1054 stype, slen, sdata) {
1055 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1056 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1057 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1058
1059 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1060
1061 if (code == DHCPV6_Success)
1062 continue;
1063
1064 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1065 code, mdata, mlen, handled_status_codes, &ret);
1066
1067 if (ret > 0)
1068 return ret;
1069
1070 break;
1071 }
1072 }
1073
1074 if (code != DHCPV6_Success)
1075 continue;
1076
1077 updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen);
1078 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1079 if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST))
1080 server_addr = *(struct in6_addr *)odata;
1081
1082 }
1083 else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1084 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1085 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1086 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1087
1088 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1089 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1090 if (olen % 16 == 0)
1091 odhcp6c_add_state(STATE_DNS, odata, olen);
1092 } else if (otype == DHCPV6_OPT_DNS_DOMAIN)
1093 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1094 else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1095 if (olen % 16 == 0)
1096 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1097 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1098 uint16_t stype, slen;
1099 uint8_t *sdata;
1100 // Test status and bail if error
1101 dhcpv6_for_each_option(odata, odata + olen,
1102 stype, slen, sdata) {
1103 if (slen == 16 && (stype == NTP_MC_ADDR ||
1104 stype == NTP_SRV_ADDR))
1105 odhcp6c_add_state(STATE_NTP_IP,
1106 sdata, slen);
1107 else if (slen > 0 && stype == NTP_SRV_FQDN)
1108 odhcp6c_add_state(STATE_NTP_FQDN,
1109 sdata, slen);
1110 }
1111 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1112 if (olen == 16)
1113 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1114 } else if (otype == DHCPV6_OPT_SIP_SERVER_D)
1115 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1116 else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1117 refresh = ntohl_unaligned(odata);
1118 } else if (otype == DHCPV6_OPT_AUTH) {
1119 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1120 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1121 if (r->protocol == 3 && r->algorithm == 1 &&
1122 r->reconf_type == 1)
1123 memcpy(reconf_key, r->key, sizeof(r->key));
1124 }
1125 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1126 size_t cur_len;
1127 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1128 if (cur_len == 0)
1129 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1130 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1131 uint32_t sol_max_rt = ntohl_unaligned(odata);
1132 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1133 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1134 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1135 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1136 uint32_t inf_max_rt = ntohl_unaligned(odata);
1137 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1138 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1139 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1140 #ifdef EXT_CER_ID
1141 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1142 sizeof(struct dhcpv6_cer_id)) {
1143 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1144 struct in6_addr any = IN6ADDR_ANY_INIT;
1145 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1146 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1147 #endif
1148 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1149 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1150 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1151 size_t mape_len;
1152 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1153 if (mape_len == 0)
1154 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1155 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1156 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1157 } else
1158 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1159
1160 if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU))
1161 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1162 }
1163 }
1164
1165 switch (orig) {
1166 case DHCPV6_MSG_REQUEST:
1167 case DHCPV6_MSG_REBIND:
1168 case DHCPV6_MSG_RENEW:
1169 // Update refresh timers if no fatal status code was received
1170 if ((ret > 0) && (ret = dhcpv6_calc_refresh_timers())) {
1171 if (orig == DHCPV6_MSG_REQUEST) {
1172 // All server candidates can be cleared if not yet bound
1173 if (!odhcp6c_is_bound())
1174 dhcpv6_clear_all_server_cand();
1175
1176 odhcp6c_clear_state(STATE_SERVER_ADDR);
1177 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1178 } else if (orig == DHCPV6_MSG_RENEW) {
1179 // Send further renews if T1 is not set and
1180 // no updated IAs
1181 if (!t1) {
1182 if (!updated_IAs)
1183 ret = -1;
1184 else if ((t2 - t1) > 1)
1185 // Grace period of 1 second
1186 t1 = 1;
1187 }
1188
1189 } else if (orig == DHCPV6_MSG_REBIND) {
1190 // Send further rebinds if T1 and T2 is not set and
1191 // no updated IAs
1192 if (!t1 && !t2) {
1193 if (!updated_IAs)
1194 ret = -1;
1195 else if ((t3 - t2) > 1)
1196 // Grace period of 1 second
1197 t2 = 1;
1198 }
1199
1200 odhcp6c_clear_state(STATE_SERVER_ADDR);
1201 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1202 }
1203 }
1204 break;
1205
1206 case DHCPV6_MSG_INFO_REQ:
1207 if (ret > 0) {
1208 // All server candidates can be cleared if not yet bound
1209 if (!odhcp6c_is_bound())
1210 dhcpv6_clear_all_server_cand();
1211
1212 t1 = refresh;
1213 }
1214 break;
1215
1216 default:
1217 break;
1218 }
1219
1220 return ret;
1221 }
1222
1223 static unsigned int dhcpv6_parse_ia(void *opt, void *end)
1224 {
1225 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1226 unsigned int updated_IAs = 0;
1227 uint32_t t1, t2;
1228 uint16_t otype, olen;
1229 uint8_t *odata;
1230
1231 t1 = ntohl(ia_hdr->t1);
1232 t2 = ntohl(ia_hdr->t2);
1233
1234 if (t1 > t2)
1235 return 0;
1236
1237 // Update address IA
1238 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1239 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1240 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1241
1242 entry.iaid = ia_hdr->iaid;
1243
1244 if (otype == DHCPV6_OPT_IA_PREFIX) {
1245 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1246 if (olen + 4U < sizeof(*prefix))
1247 continue;
1248
1249 entry.valid = ntohl(prefix->valid);
1250 entry.preferred = ntohl(prefix->preferred);
1251
1252 if (entry.preferred > entry.valid)
1253 continue;
1254
1255 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1256 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1257 if (entry.t1 > entry.t2)
1258 entry.t1 = entry.t2;
1259
1260 entry.length = prefix->prefix;
1261 entry.target = prefix->addr;
1262 uint16_t stype, slen;
1263 uint8_t *sdata;
1264
1265 // Parse PD-exclude
1266 bool ok = true;
1267 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1268 odata + olen, stype, slen, sdata) {
1269 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1270 continue;
1271
1272 uint8_t elen = sdata[0];
1273 if (elen > 64)
1274 elen = 64;
1275
1276 if (entry.length < 32 || elen <= entry.length) {
1277 ok = false;
1278 continue;
1279 }
1280
1281 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1282 if (slen <= bytes) {
1283 ok = false;
1284 continue;
1285 }
1286
1287 uint32_t exclude = 0;
1288 do {
1289 exclude = exclude << 8 | sdata[bytes];
1290 } while (--bytes);
1291
1292 exclude >>= 8 - ((elen - entry.length) % 8);
1293 exclude <<= 64 - elen;
1294
1295 // Abusing router & priority fields for exclusion
1296 entry.router = entry.target;
1297 entry.router.s6_addr32[1] |= htonl(exclude);
1298 entry.priority = elen;
1299 }
1300
1301 if (ok) {
1302 if (odhcp6c_update_entry(STATE_IA_PD, &entry, 0, 0))
1303 updated_IAs++;
1304 }
1305
1306 entry.priority = 0;
1307 memset(&entry.router, 0, sizeof(entry.router));
1308 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1309 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1310 if (olen + 4U < sizeof(*addr))
1311 continue;
1312
1313 entry.preferred = ntohl(addr->preferred);
1314 entry.valid = ntohl(addr->valid);
1315
1316 if (entry.preferred > entry.valid)
1317 continue;
1318
1319 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1320 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1321 if (entry.t1 > entry.t2)
1322 entry.t1 = entry.t2;
1323
1324 entry.length = 128;
1325 entry.target = addr->addr;
1326
1327 if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0))
1328 updated_IAs++;
1329 }
1330 }
1331 return updated_IAs;
1332 }
1333
1334 static int dhcpv6_calc_refresh_timers(void)
1335 {
1336 struct odhcp6c_entry *e;
1337 size_t ia_na_entries, ia_pd_entries, i;
1338 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1339
1340 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1341 ia_na_entries /= sizeof(*e);
1342
1343 for (i = 0; i < ia_na_entries; i++) {
1344 if (e[i].t1 < l_t1)
1345 l_t1 = e[i].t1;
1346
1347 if (e[i].t2 < l_t2)
1348 l_t2 = e[i].t2;
1349
1350 if (e[i].valid > l_t3)
1351 l_t3 = e[i].valid;
1352 }
1353
1354 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1355 ia_pd_entries /= sizeof(*e);
1356
1357 for (i = 0; i < ia_pd_entries; i++) {
1358 if (e[i].t1 < l_t1)
1359 l_t1 = e[i].t1;
1360
1361 if (e[i].t2 < l_t2)
1362 l_t2 = e[i].t2;
1363
1364 if (e[i].valid > l_t3)
1365 l_t3 = e[i].valid;
1366 }
1367
1368 if (ia_pd_entries || ia_na_entries) {
1369 t1 = l_t1;
1370 t2 = l_t2;
1371 t3 = l_t3;
1372 }
1373
1374 return (int)(ia_pd_entries + ia_na_entries);
1375 }
1376
1377 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1378 const void *status_msg, int len)
1379 {
1380 const char *src = status_msg;
1381 char buf[len + 3];
1382 char *dst = buf;
1383
1384 if (len) {
1385 *dst++ = '(';
1386 while (len--) {
1387 *dst = isprint((unsigned char)*src) ? *src : '?';
1388 src++;
1389 dst++;
1390 }
1391 *dst++ = ')';
1392 }
1393
1394 *dst = 0;
1395
1396 syslog(LOG_WARNING, "Server returned %s status %i %s",
1397 scope, code, buf);
1398 }
1399
1400 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1401 const uint16_t code, const void *status_msg, const int len,
1402 int *ret)
1403 {
1404 dhcpv6_log_status_code(code, "message", status_msg, len);
1405
1406 switch (code) {
1407 case DHCPV6_UnspecFail:
1408 // Generic failure
1409 *ret = 0;
1410 break;
1411
1412 case DHCPV6_UseMulticast:
1413 switch(orig) {
1414 case DHCPV6_MSG_REQUEST:
1415 case DHCPV6_MSG_RENEW:
1416 case DHCPV6_MSG_RELEASE:
1417 case DHCPV6_MSG_DECLINE:
1418 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1419 server_addr = in6addr_any;
1420 *ret = 0;
1421 break;
1422 default:
1423 break;
1424 }
1425 break;
1426
1427 case DHCPV6_NoAddrsAvail:
1428 case DHCPV6_NoPrefixAvail:
1429 if (orig == DHCPV6_MSG_REQUEST)
1430 *ret = 0; // Failure
1431 break;
1432
1433 default:
1434 break;
1435 }
1436 }
1437
1438 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1439 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1440 const void *status_msg, const int len,
1441 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1442 {
1443 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1444 "IA_NA" : "IA_PD", status_msg, len);
1445
1446 switch (code) {
1447 case DHCPV6_NoBinding:
1448 switch (orig) {
1449 case DHCPV6_MSG_RENEW:
1450 case DHCPV6_MSG_REBIND:
1451 if ((*ret > 0) && !handled_status_codes[code])
1452 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1453 break;
1454
1455 default:
1456 break;
1457 }
1458 break;
1459
1460 default:
1461 *ret = 0;
1462 break;
1463 }
1464 }
1465
1466 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1467 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1468 {
1469 size_t cand_len, i;
1470 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1471
1472 // Remove identical duid server candidate
1473 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1474 if (cand->duid_len == c[i].duid_len &&
1475 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1476 free(c[i].ia_na);
1477 free(c[i].ia_pd);
1478 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1479 break;
1480 }
1481 }
1482
1483 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1484 i < cand_len / sizeof(*c); ++i) {
1485 if (c[i].preference < cand->preference)
1486 break;
1487 }
1488
1489 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1490 free(cand->ia_na);
1491 free(cand->ia_pd);
1492 }
1493 }
1494
1495 static void dhcpv6_clear_all_server_cand(void)
1496 {
1497 size_t cand_len, i;
1498 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1499
1500 // Server candidates need deep delete for IA_NA/IA_PD
1501 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1502 free(c[i].ia_na);
1503 free(c[i].ia_pd);
1504 }
1505 odhcp6c_clear_state(STATE_SERVER_CAND);
1506 }
1507
1508 int dhcpv6_promote_server_cand(void)
1509 {
1510 size_t cand_len;
1511 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1512 uint16_t hdr[2];
1513 int ret = DHCPV6_STATELESS;
1514
1515 // Clear lingering candidate state info
1516 odhcp6c_clear_state(STATE_SERVER_ID);
1517 odhcp6c_clear_state(STATE_IA_NA);
1518 odhcp6c_clear_state(STATE_IA_PD);
1519
1520 if (!cand_len)
1521 return -1;
1522
1523 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1524 na_mode = IA_MODE_NONE;
1525
1526 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1527 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1528
1529 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1530 }
1531
1532 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1533 hdr[1] = htons(cand->duid_len);
1534 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1535 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1536 accept_reconfig = cand->wants_reconfigure;
1537
1538 if (cand->ia_na_len) {
1539 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1540 free(cand->ia_na);
1541 if (na_mode != IA_MODE_NONE)
1542 ret = DHCPV6_STATEFUL;
1543 }
1544
1545 if (cand->ia_pd_len) {
1546 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1547 free(cand->ia_pd);
1548 if (request_prefix)
1549 ret = DHCPV6_STATEFUL;
1550 }
1551
1552 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1553 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1554
1555 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1556
1557 return ret;
1558 }
Openwrt DHCPv6 Client