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