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More compatibility with non RFC-compliant servers
[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30
31 #include <net/if.h>
32 #include <net/ethernet.h>
33
34 #include "odhcp6c.h"
35 #include "md5.h"
36
37
38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
39 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
40 #define DHCPV6_CLIENT_PORT 546
41 #define DHCPV6_SERVER_PORT 547
42 #define DHCPV6_DUID_LLADDR 3
43 #define DHCPV6_REQ_DELAY 1
44
45 #define DHCPV6_SOL_MAX_RT_MIN 60
46 #define DHCPV6_SOL_MAX_RT_MAX 86400
47 #define DHCPV6_INF_MAX_RT_MIN 60
48 #define DHCPV6_INF_MAX_RT_MAX 86400
49
50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
51 const uint8_t transaction[3], enum dhcpv6_msg type,
52 const struct in6_addr *daddr);
53
54 static int dhcpv6_parse_ia(void *opt, void *end);
55
56 static int dhcpv6_calc_refresh_timers(void);
57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
58 const uint16_t code, const void *status_msg, const int len,
59 int *ret);
60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
61 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
62 const void *status_msg, const int len,
63 bool handled_status_codes[_DHCPV6_Status_Max],
64 int *ret);
65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
66 static void dhcpv6_clear_all_server_cand(void);
67
68 static reply_handler dhcpv6_handle_reply;
69 static reply_handler dhcpv6_handle_advert;
70 static reply_handler dhcpv6_handle_rebind_reply;
71 static reply_handler dhcpv6_handle_reconfigure;
72 static int dhcpv6_commit_advert(void);
73
74
75
76 // RFC 3315 - 5.5 Timeout and Delay values
77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
78 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
79 dhcpv6_handle_reconfigure, NULL},
80 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
81 dhcpv6_handle_advert, dhcpv6_commit_advert},
82 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
83 dhcpv6_handle_reply, NULL},
84 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
85 dhcpv6_handle_reply, NULL},
86 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
87 dhcpv6_handle_rebind_reply, NULL},
88 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
89 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
90 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
91 dhcpv6_handle_reply, NULL},
92 };
93
94
95 // Sockets
96 static int sock = -1;
97 static int ifindex = -1;
98 static int64_t t1 = 0, t2 = 0, t3 = 0;
99
100 // IA states
101 static int request_prefix = -1;
102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
103 static bool accept_reconfig = false;
104
105 // Reconfigure key
106 static uint8_t reconf_key[16];
107
108 // client options
109 static unsigned int client_options = 0;
110
111
112 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
113 {
114 client_options = options;
115 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
116
117 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
118 if (sock < 0)
119 return -1;
120
121 // Detect interface
122 struct ifreq ifr;
123 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
124 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
125 return -1;
126 ifindex = ifr.ifr_ifindex;
127
128 // Create client DUID
129 size_t client_id_len;
130 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
131 if (client_id_len == 0) {
132 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
133 DHCPV6_DUID_LLADDR, 0, 1};
134
135 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
136 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
137
138 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
139 struct ifreq ifs[100], *ifp, *ifend;
140 struct ifconf ifc;
141 ifc.ifc_req = ifs;
142 ifc.ifc_len = sizeof(ifs);
143
144 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
145 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
146 // If our interface doesn't have an address...
147 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
148 for (ifp = ifc.ifc_req; ifp < ifend &&
149 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
150 memcpy(ifr.ifr_name, ifp->ifr_name,
151 sizeof(ifr.ifr_name));
152 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
153 continue;
154
155 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
156 ETHER_ADDR_LEN);
157 }
158 }
159
160 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
161 }
162
163 // Create ORO
164 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
165 uint16_t oro[] = {
166 htons(DHCPV6_OPT_SIP_SERVER_D),
167 htons(DHCPV6_OPT_SIP_SERVER_A),
168 htons(DHCPV6_OPT_DNS_SERVERS),
169 htons(DHCPV6_OPT_DNS_DOMAIN),
170 htons(DHCPV6_OPT_SNTP_SERVERS),
171 htons(DHCPV6_OPT_NTP_SERVER),
172 htons(DHCPV6_OPT_AFTR_NAME),
173 htons(DHCPV6_OPT_PD_EXCLUDE),
174 htons(DHCPV6_OPT_SOL_MAX_RT),
175 htons(DHCPV6_OPT_INF_MAX_RT),
176 #ifdef EXT_PREFIX_CLASS
177 htons(DHCPV6_OPT_PREFIX_CLASS),
178 #endif
179 #ifdef EXT_CER_ID
180 htons(DHCPV6_OPT_CER_ID),
181 #endif
182 htons(DHCPV6_OPT_S46_CONT_MAPE),
183 htons(DHCPV6_OPT_S46_CONT_MAPT),
184 htons(DHCPV6_OPT_S46_CONT_LW),
185 };
186 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
187 }
188
189 // Configure IPv6-options
190 int val = 1;
191 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
192 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
193 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
194 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
195
196 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
197 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
198 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
199 return -1;
200
201 return 0;
202 }
203
204 enum {
205 IOV_HDR=0,
206 IOV_ORO,
207 IOV_ORO_REFRESH,
208 IOV_CL_ID,
209 IOV_SRV_ID,
210 IOV_VENDOR_CLASS_HDR,
211 IOV_VENDOR_CLASS,
212 IOV_USER_CLASS_HDR,
213 IOV_USER_CLASS,
214 IOV_RECONF_ACCEPT,
215 IOV_FQDN,
216 IOV_HDR_IA_NA,
217 IOV_IA_NA,
218 IOV_IA_PD,
219 IOV_TOTAL
220 };
221
222 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
223 {
224 na_mode = na;
225 pd_mode = pd;
226 }
227
228 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
229 {
230 // Build FQDN
231 char fqdn_buf[256];
232 gethostname(fqdn_buf, sizeof(fqdn_buf));
233 struct {
234 uint16_t type;
235 uint16_t len;
236 uint8_t flags;
237 uint8_t data[256];
238 } fqdn;
239 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
240 sizeof(fqdn.data), NULL, NULL);
241 fqdn.type = htons(DHCPV6_OPT_FQDN);
242 fqdn.len = htons(fqdn_len - 4);
243 fqdn.flags = 0;
244
245
246 // Build Client ID
247 size_t cl_id_len;
248 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
249
250 // Get Server ID
251 size_t srv_id_len;
252 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
253
254 // Build IA_PDs
255 size_t ia_pd_entries = 0, ia_pd_len = 0;
256 uint8_t *ia_pd;
257
258 if (type == DHCPV6_MSG_SOLICIT) {
259 odhcp6c_clear_state(STATE_IA_PD);
260 size_t n_prefixes;
261 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
262 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
263
264 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
265
266 for (size_t i = 0; i < n_prefixes; i++) {
267 struct dhcpv6_ia_hdr hdr_ia_pd = {
268 htons(DHCPV6_OPT_IA_PD),
269 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
270 request_prefixes[i].iaid, 0, 0
271 };
272 struct dhcpv6_ia_prefix pref = {
273 .type = htons(DHCPV6_OPT_IA_PREFIX),
274 .len = htons(25), .prefix = request_prefixes[i].length
275 };
276 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
277 ia_pd_len += sizeof(hdr_ia_pd);
278 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
279 ia_pd_len += sizeof(pref);
280 }
281 } else {
282 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
283 ia_pd_entries /= sizeof(*e);
284
285 // we're too lazy to count our distinct IAIDs,
286 // so just allocate maximally needed space
287 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
288 sizeof(struct dhcpv6_ia_hdr)));
289
290 for (size_t i = 0; i < ia_pd_entries; ++i) {
291 uint32_t iaid = e[i].iaid;
292
293 // check if this is an unprocessed IAID and skip if not.
294 int new_iaid = 1;
295 for (int j = i-1; j >= 0; j--) {
296 if (e[j].iaid == iaid) {
297 new_iaid = 0;
298 break;
299 }
300 }
301
302 if (!new_iaid)
303 continue;
304
305 // construct header
306 struct dhcpv6_ia_hdr hdr_ia_pd = {
307 htons(DHCPV6_OPT_IA_PD),
308 htons(sizeof(hdr_ia_pd) - 4),
309 iaid, 0, 0
310 };
311
312 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
313 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
314 ia_pd_len += sizeof(hdr_ia_pd);
315
316 for (size_t j = i; j < ia_pd_entries; j++) {
317 if (e[j].iaid != iaid)
318 continue;
319
320 uint8_t ex_len = 0;
321 if (e[j].priority > 0)
322 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
323
324 struct dhcpv6_ia_prefix p = {
325 .type = htons(DHCPV6_OPT_IA_PREFIX),
326 .len = htons(sizeof(p) - 4U + ex_len),
327 .prefix = e[j].length,
328 .addr = e[j].target
329 };
330
331 if (type == DHCPV6_MSG_REQUEST) {
332 p.preferred = htonl(e[j].preferred);
333 p.valid = htonl(e[j].valid);
334 }
335
336 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
337 ia_pd_len += sizeof(p);
338
339 if (ex_len) {
340 ia_pd[ia_pd_len++] = 0;
341 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
342 ia_pd[ia_pd_len++] = 0;
343 ia_pd[ia_pd_len++] = ex_len - 4;
344 ia_pd[ia_pd_len++] = e[j].priority;
345
346 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
347 excl >>= (64 - e[j].priority);
348 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
349
350 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
351 ia_pd[ia_pd_len + i] = excl & 0xff;
352 ia_pd_len += ex_len - 5;
353 }
354
355 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
356 }
357 }
358 }
359
360 if (ia_pd_entries > 0)
361 request_prefix = 1;
362
363 // Build IA_NAs
364 size_t ia_na_entries, ia_na_len = 0;
365 void *ia_na = NULL;
366 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
367 ia_na_entries /= sizeof(*e);
368
369 struct dhcpv6_ia_hdr hdr_ia_na = {
370 htons(DHCPV6_OPT_IA_NA),
371 htons(sizeof(hdr_ia_na) - 4),
372 htonl(1), 0, 0
373 };
374
375 struct dhcpv6_ia_addr pa[ia_na_entries];
376 for (size_t i = 0; i < ia_na_entries; ++i) {
377 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
378 pa[i].len = htons(sizeof(pa[i]) - 4U);
379 pa[i].addr = e[i].target;
380
381 if (type == DHCPV6_MSG_REQUEST) {
382 pa[i].preferred = htonl(e[i].preferred);
383 pa[i].valid = htonl(e[i].valid);
384 } else {
385 pa[i].preferred = 0;
386 pa[i].valid = 0;
387 }
388 }
389
390 ia_na = pa;
391 ia_na_len = sizeof(pa);
392 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
393
394 // Reconfigure Accept
395 struct {
396 uint16_t type;
397 uint16_t length;
398 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
399
400 // Request Information Refresh
401 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
402
403 // Build vendor-class option
404 size_t vendor_class_len, user_class_len;
405 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
406 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
407
408 struct {
409 uint16_t type;
410 uint16_t length;
411 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
412
413 struct {
414 uint16_t type;
415 uint16_t length;
416 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
417
418 // Prepare Header
419 size_t oro_len;
420 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
421 struct {
422 uint8_t type;
423 uint8_t trid[3];
424 uint16_t elapsed_type;
425 uint16_t elapsed_len;
426 uint16_t elapsed_value;
427 uint16_t oro_type;
428 uint16_t oro_len;
429 } hdr = {
430 type, {trid[0], trid[1], trid[2]},
431 htons(DHCPV6_OPT_ELAPSED), htons(2),
432 htons((ecs > 0xffff) ? 0xffff : ecs),
433 htons(DHCPV6_OPT_ORO), htons(oro_len),
434 };
435
436 struct iovec iov[IOV_TOTAL] = {
437 [IOV_HDR] = {&hdr, sizeof(hdr)},
438 [IOV_ORO] = {oro, oro_len},
439 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
440 [IOV_CL_ID] = {cl_id, cl_id_len},
441 [IOV_SRV_ID] = {srv_id, srv_id_len},
442 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
443 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
444 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
445 [IOV_USER_CLASS] = {user_class, user_class_len},
446 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
447 [IOV_FQDN] = {&fqdn, fqdn_len},
448 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
449 [IOV_IA_NA] = {ia_na, ia_na_len},
450 [IOV_IA_PD] = {ia_pd, ia_pd_len},
451 };
452
453 size_t cnt = IOV_TOTAL;
454 if (type == DHCPV6_MSG_INFO_REQ) {
455 cnt = 9;
456 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
457 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
458 } else if (!request_prefix) {
459 cnt = 13;
460 }
461
462 // Disable IAs if not used
463 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
464 iov[IOV_HDR_IA_NA].iov_len = 0;
465
466 if (na_mode == IA_MODE_NONE)
467 iov[IOV_HDR_IA_NA].iov_len = 0;
468
469 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
470 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
471 iov[IOV_RECONF_ACCEPT].iov_len = 0;
472
473 if (!(client_options & DHCPV6_CLIENT_FQDN))
474 iov[IOV_FQDN].iov_len = 0;
475
476 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
477 0, ALL_DHCPV6_RELAYS, ifindex};
478 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
479 .msg_iov = iov, .msg_iovlen = cnt};
480
481 sendmsg(sock, &msg, 0);
482 }
483
484
485 static int64_t dhcpv6_rand_delay(int64_t time)
486 {
487 int random;
488 odhcp6c_random(&random, sizeof(random));
489 return (time * ((int64_t)random % 1000LL)) / 10000LL;
490 }
491
492
493 int dhcpv6_request(enum dhcpv6_msg type)
494 {
495 uint8_t rc = 0;
496 uint64_t timeout = UINT32_MAX;
497 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
498
499 if (retx->delay) {
500 struct timespec ts = {0, 0};
501 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
502 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
503 }
504
505 if (type == DHCPV6_MSG_UNKNOWN)
506 timeout = t1;
507 else if (type == DHCPV6_MSG_RENEW)
508 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
509 else if (type == DHCPV6_MSG_REBIND)
510 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
511
512 if (timeout == 0)
513 return -1;
514
515 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
516 retx->name, (unsigned long long)timeout, retx->max_rc);
517
518 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
519
520 // Generate transaction ID
521 uint8_t trid[3] = {0, 0, 0};
522 if (type != DHCPV6_MSG_UNKNOWN)
523 odhcp6c_random(trid, sizeof(trid));
524 ssize_t len = -1;
525 int64_t rto = 0;
526
527 do {
528 if (rto == 0) {
529 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
530
531 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
532 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
533 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
534
535 rto = (retx->init_timeo * 1000 + delay);
536 }
537 else
538 rto = (2 * rto + dhcpv6_rand_delay(rto));
539
540 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
541 rto = retx->max_timeo * 1000 +
542 dhcpv6_rand_delay(retx->max_timeo * 1000);
543
544 // Calculate end for this round and elapsed time
545 uint64_t round_end = round_start + rto;
546 elapsed = round_start - start;
547
548 // Don't wait too long if timeout differs from infinite
549 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
550 round_end = timeout * 1000 + start;
551
552 // Built and send package
553 if (type != DHCPV6_MSG_UNKNOWN) {
554 if (type != DHCPV6_MSG_SOLICIT)
555 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
556 retx->name, (unsigned long long)elapsed, rc);
557 dhcpv6_send(type, trid, elapsed / 10);
558 rc++;
559 }
560
561 // Receive rounds
562 for (; len < 0 && (round_start < round_end);
563 round_start = odhcp6c_get_milli_time()) {
564 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
565 struct iovec iov = {buf, sizeof(buf)};
566 struct sockaddr_in6 addr;
567 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
568 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf,
569 .msg_controllen = sizeof(cmsg_buf)};
570 struct in6_pktinfo *pktinfo = NULL;
571
572
573 // Check for pending signal
574 if (odhcp6c_signal_process())
575 return -1;
576
577 // Set timeout for receiving
578 uint64_t t = round_end - round_start;
579 struct timeval tv = {t / 1000, (t % 1000) * 1000};
580 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
581 &tv, sizeof(tv));
582
583 // Receive cycle
584 len = recvmsg(sock, &msg, 0);
585 if (len < 0)
586 continue;
587
588 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
589 ch = CMSG_NXTHDR(&msg, ch)) {
590 if (ch->cmsg_level == SOL_IPV6 &&
591 ch->cmsg_type == IPV6_PKTINFO) {
592 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
593 break;
594 }
595 }
596
597 if (pktinfo == NULL) {
598 len = -1;
599 continue;
600 }
601
602 if (!dhcpv6_response_is_valid(buf, len, trid,
603 type, &pktinfo->ipi6_addr)) {
604 len = -1;
605 continue;
606 }
607
608 uint8_t *opt = &buf[4];
609 uint8_t *opt_end = opt + len - 4;
610
611 round_start = odhcp6c_get_milli_time();
612 elapsed = round_start - start;
613 syslog(LOG_NOTICE, "Got a valid reply after "
614 "%llums", (unsigned long long)elapsed);
615
616 if (retx->handler_reply)
617 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
618
619 if (len > 0 && round_end - round_start > 1000)
620 round_end = 1000 + round_start;
621 }
622
623 // Allow
624 if (retx->handler_finish)
625 len = retx->handler_finish();
626 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
627 (!retx->max_rc || rc < retx->max_rc));
628 return len;
629 }
630
631 // Message validation checks according to RFC3315 chapter 15
632 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
633 const uint8_t transaction[3], enum dhcpv6_msg type,
634 const struct in6_addr *daddr)
635 {
636 const struct dhcpv6_header *rep = buf;
637 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
638 transaction, sizeof(rep->tr_id)))
639 return false; // Invalid reply
640
641 if (type == DHCPV6_MSG_SOLICIT) {
642 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
643 rep->msg_type != DHCPV6_MSG_REPLY)
644 return false;
645 } else if (type == DHCPV6_MSG_UNKNOWN) {
646 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
647 return false;
648 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
649 return false;
650 }
651
652 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
653 rcmsg = DHCPV6_MSG_UNKNOWN;
654 uint16_t otype, olen = UINT16_MAX;
655 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
656 ia_present = false, options_valid = true;
657
658 size_t client_id_len, server_id_len;
659 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
660 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
661
662 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
663 if (otype == DHCPV6_OPT_CLIENTID) {
664 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
665 &odata[-4], client_id, client_id_len);
666 } else if (otype == DHCPV6_OPT_SERVERID) {
667 if (server_id_len)
668 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
669 &odata[-4], server_id, server_id_len);
670 else
671 serverid_ok = true;
672 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
673 sizeof(struct dhcpv6_auth_reconfigure)) {
674 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
675 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
676 continue;
677
678 md5_ctx_t md5;
679 uint8_t serverhash[16], secretbytes[64], hash[16];
680 memcpy(serverhash, r->key, sizeof(serverhash));
681 memset(r->key, 0, sizeof(r->key));
682
683 memset(secretbytes, 0, sizeof(secretbytes));
684 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
685
686 for (size_t i = 0; i < sizeof(secretbytes); ++i)
687 secretbytes[i] ^= 0x36;
688
689 md5_begin(&md5);
690 md5_hash(secretbytes, sizeof(secretbytes), &md5);
691 md5_hash(buf, len, &md5);
692 md5_end(hash, &md5);
693
694 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
695 secretbytes[i] ^= 0x36;
696 secretbytes[i] ^= 0x5c;
697 }
698
699 md5_begin(&md5);
700 md5_hash(secretbytes, sizeof(secretbytes), &md5);
701 md5_hash(hash, 16, &md5);
702 md5_end(hash, &md5);
703
704 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
705 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
706 rcmsg = odata[0];
707 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
708 ia_present = true;
709 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
710 options_valid = false;
711 }
712 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
713 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
714 // Options are not allowed on global level
715 options_valid = false;
716 }
717 }
718
719 if (!options_valid || ((odata + olen) > end))
720 return false;
721
722 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
723 return false;
724
725 if (rep->msg_type == DHCPV6_MSG_RECONF) {
726 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
727 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
728 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
729 return false;
730 }
731
732 return clientid_ok && serverid_ok;
733 }
734
735
736 int dhcpv6_poll_reconfigure(void)
737 {
738 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
739 if (ret != -1)
740 ret = dhcpv6_request(ret);
741
742 return ret;
743 }
744
745
746 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
747 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
748 {
749 uint16_t otype, olen;
750 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
751 dhcpv6_for_each_option(opt, end, otype, olen, odata)
752 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
753 odata[0] == DHCPV6_MSG_RENEW ||
754 odata[0] == DHCPV6_MSG_INFO_REQ))
755 msg = odata[0];
756
757 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL, NULL);
758 return msg;
759 }
760
761
762 // Collect all advertised servers
763 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
764 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
765 {
766 uint16_t olen, otype;
767 uint8_t *odata, pref = 0;
768 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
769 DHCPV6_SOL_MAX_RT,
770 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
771 bool have_na = false;
772 int have_pd = 0;
773
774 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
775 if (orig == DHCPV6_MSG_SOLICIT &&
776 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
777 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
778 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
779 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
780 }
781
782 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
783 memcpy(cand.duid, odata, olen);
784 cand.duid_len = olen;
785 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
786 int error = ((int)odata[0] << 8 | (int)odata[1]);
787
788 switch (error) {
789 case DHCPV6_NoPrefixAvail:
790 // Status code on global level
791 cand.preference -= 2000;
792 break;
793
794 default :
795 break;
796 }
797 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
798 cand.preference >= 0) {
799 cand.preference = pref = odata[0];
800 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
801 cand.wants_reconfigure = true;
802 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
803 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
804 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
805 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
806 cand.sol_max_rt = sol_max_rt;
807 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
808 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
809 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
810 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
811 cand.inf_max_rt = inf_max_rt;
812 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
813 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
814 uint8_t *oend = odata + olen, *d;
815 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
816 if (otype == DHCPV6_OPT_IA_PREFIX &&
817 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
818 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
819 have_pd = p->prefix;
820 }
821 }
822 } else if (otype == DHCPV6_OPT_IA_NA) {
823 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
824 uint8_t *oend = odata + olen, *d;
825 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
826 if (otype == DHCPV6_OPT_IA_ADDR &&
827 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
828 have_na = true;
829 }
830 }
831
832 if ((!have_na && na_mode == IA_MODE_FORCE) ||
833 (!have_pd && pd_mode == IA_MODE_FORCE)) {
834 /*
835 * RFC7083 states to process the SOL_MAX_RT and
836 * INF_MAX_RT options even if the DHCPv6 server
837 * did not propose any IA_NA and/or IA_PD
838 */
839 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
840 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
841 return -1;
842 }
843
844 if (na_mode != IA_MODE_NONE && !have_na) {
845 cand.has_noaddravail = true;
846 cand.preference -= 1000;
847 }
848
849 if (pd_mode != IA_MODE_NONE) {
850 if (have_pd)
851 cand.preference += 2000 + (128 - have_pd);
852 else
853 cand.preference -= 2000;
854 }
855
856 if (cand.duid_len > 0) {
857 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
858 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
859 dhcpv6_add_server_cand(&cand);
860 }
861
862 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
863 }
864
865
866 static int dhcpv6_commit_advert(void)
867 {
868 return dhcpv6_promote_server_cand();
869 }
870
871
872 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
873 const void *opt, const void *end, const struct sockaddr_in6 *from)
874 {
875 dhcpv6_handle_advert(orig, rc, opt, end, from);
876 if (dhcpv6_commit_advert() < 0)
877 return -1;
878
879 return dhcpv6_handle_reply(orig, rc, opt, end, from);
880 }
881
882
883 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
884 const void *opt, const void *end, const struct sockaddr_in6 *from)
885 {
886 uint8_t *odata;
887 uint16_t otype, olen;
888 uint32_t refresh = UINT32_MAX;
889 int ret = 1;
890 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
891
892 odhcp6c_expire();
893
894 if (orig == DHCPV6_MSG_UNKNOWN) {
895 static time_t last_update = 0;
896 time_t now = odhcp6c_get_milli_time() / 1000;
897
898 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
899 last_update = now;
900
901 if (t1 != UINT32_MAX)
902 t1 -= elapsed;
903
904 if (t2 != UINT32_MAX)
905 t2 -= elapsed;
906
907 if (t3 != UINT32_MAX)
908 t3 -= elapsed;
909
910 if (t1 < 0)
911 t1 = 0;
912
913 if (t2 < 0)
914 t2 = 0;
915
916 if (t3 < 0)
917 t3 = 0;
918 }
919
920 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
921 // Delete NA and PD we have in the state from the Advert
922 odhcp6c_clear_state(STATE_IA_NA);
923 odhcp6c_clear_state(STATE_IA_PD);
924 }
925
926 if (opt) {
927 odhcp6c_clear_state(STATE_DNS);
928 odhcp6c_clear_state(STATE_SEARCH);
929 odhcp6c_clear_state(STATE_SNTP_IP);
930 odhcp6c_clear_state(STATE_NTP_IP);
931 odhcp6c_clear_state(STATE_NTP_FQDN);
932 odhcp6c_clear_state(STATE_SIP_IP);
933 odhcp6c_clear_state(STATE_SIP_FQDN);
934 odhcp6c_clear_state(STATE_AFTR_NAME);
935 odhcp6c_clear_state(STATE_CER);
936 odhcp6c_clear_state(STATE_S46_MAPT);
937 odhcp6c_clear_state(STATE_S46_MAPE);
938 odhcp6c_clear_state(STATE_S46_LW);
939 odhcp6c_clear_state(STATE_PASSTHRU);
940 }
941
942 // Parse and find all matching IAs
943 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
944 bool passthru = true;
945
946 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
947 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
948 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
949
950 // Test ID
951 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
952 continue;
953
954 uint16_t code = DHCPV6_Success;
955 uint16_t stype, slen;
956 uint8_t *sdata;
957 // Get and handle status code
958 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
959 stype, slen, sdata) {
960 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
961 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
962 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
963
964 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
965
966 if (code == DHCPV6_Success)
967 continue;
968
969 dhcpv6_handle_ia_status_code(orig, ia_hdr,
970 code, mdata, mlen, handled_status_codes, &ret);
971
972
973 if (ret > 0)
974 return ret;
975 break;
976 }
977 }
978
979 if (code != DHCPV6_Success)
980 continue;
981
982 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
983 passthru = false;
984 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
985 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
986 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
987 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
988
989 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
990 passthru = false;
991 }
992 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
993 if (olen % 16 == 0)
994 odhcp6c_add_state(STATE_DNS, odata, olen);
995 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
996 odhcp6c_add_state(STATE_SEARCH, odata, olen);
997 passthru = false;
998 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
999 if (olen % 16 == 0)
1000 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1001 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1002 uint16_t stype, slen;
1003 uint8_t *sdata;
1004 // Test status and bail if error
1005 dhcpv6_for_each_option(odata, odata + olen,
1006 stype, slen, sdata) {
1007 if (slen == 16 && (stype == NTP_MC_ADDR ||
1008 stype == NTP_SRV_ADDR))
1009 odhcp6c_add_state(STATE_NTP_IP,
1010 sdata, slen);
1011 else if (slen > 0 && stype == NTP_SRV_FQDN)
1012 odhcp6c_add_state(STATE_NTP_FQDN,
1013 sdata, slen);
1014 }
1015 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1016 if (olen == 16)
1017 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1018 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
1019 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1020 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1021 refresh = ntohl(*((uint32_t*)odata));
1022 passthru = false;
1023 } else if (otype == DHCPV6_OPT_AUTH) {
1024 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1025 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1026 if (r->protocol == 3 && r->algorithm == 1 &&
1027 r->reconf_type == 1)
1028 memcpy(reconf_key, r->key, sizeof(r->key));
1029 }
1030 passthru = false;
1031 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1032 size_t cur_len;
1033 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1034 if (cur_len == 0)
1035 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1036 passthru = false;
1037 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1038 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
1039 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1040 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1041 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1042 passthru = false;
1043 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1044 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
1045 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1046 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1047 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1048 passthru = false;
1049 #ifdef EXT_CER_ID
1050 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1051 sizeof(struct dhcpv6_cer_id)) {
1052 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1053 struct in6_addr any = IN6ADDR_ANY_INIT;
1054 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1055 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1056 passthru = false;
1057 #endif
1058 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1059 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1060 passthru = false;
1061 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1062 size_t mape_len;
1063 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1064 if (mape_len == 0)
1065 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1066 passthru = false;
1067 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1068 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1069 passthru = false;
1070 } else if (otype == DHCPV6_OPT_CLIENTID ||
1071 otype == DHCPV6_OPT_SERVERID ||
1072 otype == DHCPV6_OPT_IA_TA ||
1073 otype == DHCPV6_OPT_PREF ||
1074 otype == DHCPV6_OPT_UNICAST ||
1075 otype == DHCPV6_OPT_FQDN ||
1076 otype == DHCPV6_OPT_RECONF_ACCEPT) {
1077 passthru = false;
1078 } else {
1079 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1080 }
1081
1082 if (passthru)
1083 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1084 }
1085
1086 if (orig != DHCPV6_MSG_INFO_REQ) {
1087 // Update refresh timers if no fatal status code was received
1088 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1089 switch (orig) {
1090 case DHCPV6_MSG_RENEW:
1091 // Send further renews if T1 is not set
1092 if (!t1)
1093 ret = -1;
1094 break;
1095 case DHCPV6_MSG_REBIND:
1096 // Send further rebinds if T1 and T2 is not set
1097 if (!t1 && !t2)
1098 ret = -1;
1099 break;
1100
1101 case DHCPV6_MSG_REQUEST:
1102 // All server candidates can be cleared if not yet bound
1103 if (!odhcp6c_is_bound())
1104 dhcpv6_clear_all_server_cand();
1105
1106 default :
1107 break;
1108 }
1109
1110 if (orig == DHCPV6_MSG_REBIND || orig == DHCPV6_MSG_REQUEST) {
1111 odhcp6c_clear_state(STATE_SERVER_ADDR);
1112 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1113 }
1114 }
1115 }
1116 else if (ret > 0) {
1117 // All server candidates can be cleared if not yet bound
1118 if (!odhcp6c_is_bound())
1119 dhcpv6_clear_all_server_cand();
1120
1121 t1 = refresh;
1122 }
1123
1124 return ret;
1125 }
1126
1127
1128 static int dhcpv6_parse_ia(void *opt, void *end)
1129 {
1130 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1131 int parsed_ia = 0;
1132 uint32_t t1, t2;
1133 uint16_t otype, olen;
1134 uint8_t *odata;
1135
1136 t1 = ntohl(ia_hdr->t1);
1137 t2 = ntohl(ia_hdr->t2);
1138
1139 if (t1 > t2)
1140 return 0;
1141
1142 // Update address IA
1143 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1144 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1145 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1146
1147 entry.iaid = ia_hdr->iaid;
1148
1149 if (otype == DHCPV6_OPT_IA_PREFIX) {
1150 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1151 if (olen + 4U < sizeof(*prefix))
1152 continue;
1153
1154 entry.valid = ntohl(prefix->valid);
1155 entry.preferred = ntohl(prefix->preferred);
1156
1157 if (entry.preferred > entry.valid)
1158 continue;
1159
1160 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1161 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1162 if (entry.t1 > entry.t2)
1163 entry.t1 = entry.t2;
1164
1165 entry.length = prefix->prefix;
1166 entry.target = prefix->addr;
1167 uint16_t stype, slen;
1168 uint8_t *sdata;
1169
1170 #ifdef EXT_PREFIX_CLASS
1171 // Find prefix class, if any
1172 dhcpv6_for_each_option(&prefix[1], odata + olen,
1173 stype, slen, sdata)
1174 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1175 entry.class = sdata[0] << 8 | sdata[1];
1176 #endif
1177
1178 // Parse PD-exclude
1179 bool ok = true;
1180 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1181 odata + olen, stype, slen, sdata) {
1182 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1183 continue;
1184
1185 uint8_t elen = sdata[0];
1186 if (elen > 64)
1187 elen = 64;
1188
1189 if (elen <= 32 || elen <= entry.length) {
1190 ok = false;
1191 continue;
1192 }
1193
1194
1195 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1196 if (slen <= bytes) {
1197 ok = false;
1198 continue;
1199 }
1200
1201 uint32_t exclude = 0;
1202 do {
1203 exclude = exclude << 8 | sdata[bytes];
1204 } while (--bytes);
1205
1206 exclude >>= 8 - ((elen - entry.length) % 8);
1207 exclude <<= 64 - elen;
1208
1209 // Abusing router & priority fields for exclusion
1210 entry.router = entry.target;
1211 entry.router.s6_addr32[1] |= htonl(exclude);
1212 entry.priority = elen;
1213 }
1214
1215 if (ok) {
1216 odhcp6c_update_entry(STATE_IA_PD, &entry);
1217 parsed_ia++;
1218 }
1219
1220 entry.priority = 0;
1221 memset(&entry.router, 0, sizeof(entry.router));
1222 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1223 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1224 if (olen + 4U < sizeof(*addr))
1225 continue;
1226
1227 entry.preferred = ntohl(addr->preferred);
1228 entry.valid = ntohl(addr->valid);
1229
1230 if (entry.preferred > entry.valid)
1231 continue;
1232
1233 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1234 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1235 if (entry.t1 > entry.t2)
1236 entry.t1 = entry.t2;
1237
1238 entry.length = 128;
1239 entry.target = addr->addr;
1240
1241 #ifdef EXT_PREFIX_CLASS
1242 uint16_t stype, slen;
1243 uint8_t *sdata;
1244 // Find prefix class, if any
1245 dhcpv6_for_each_option(&addr[1], odata + olen,
1246 stype, slen, sdata)
1247 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1248 entry.class = sdata[0] << 8 | sdata[1];
1249 #endif
1250
1251 odhcp6c_update_entry(STATE_IA_NA, &entry);
1252 parsed_ia++;
1253 }
1254 }
1255 return parsed_ia;
1256 }
1257
1258
1259 static int dhcpv6_calc_refresh_timers(void)
1260 {
1261 struct odhcp6c_entry *e;
1262 size_t ia_na_entries, ia_pd_entries, i;
1263 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1264
1265 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1266 ia_na_entries /= sizeof(*e);
1267 for (i = 0; i < ia_na_entries; i++) {
1268 if (e[i].t1 < l_t1)
1269 l_t1 = e[i].t1;
1270
1271 if (e[i].t2 < l_t2)
1272 l_t2 = e[i].t2;
1273
1274 if (e[i].valid > l_t3)
1275 l_t3 = e[i].valid;
1276 }
1277
1278 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1279 ia_pd_entries /= sizeof(*e);
1280 for (i = 0; i < ia_pd_entries; i++) {
1281 if (e[i].t1 < l_t1)
1282 l_t1 = e[i].t1;
1283
1284 if (e[i].t2 < l_t2)
1285 l_t2 = e[i].t2;
1286
1287 if (e[i].valid > l_t3)
1288 l_t3 = e[i].valid;
1289 }
1290
1291 if (ia_pd_entries || ia_na_entries) {
1292 t1 = l_t1;
1293 t2 = l_t2;
1294 t3 = l_t3;
1295 } else {
1296 t1 = 600;
1297 }
1298
1299 return (int)(ia_pd_entries + ia_na_entries);
1300 }
1301
1302
1303 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1304 const void *status_msg, const int len)
1305 {
1306 uint8_t buf[len + 3];
1307
1308 memset(buf, 0, sizeof(buf));
1309 if (len) {
1310 buf[0] = '(';
1311 memcpy(&buf[1], status_msg, len);
1312 buf[len + 1] = ')';
1313 }
1314
1315 syslog(LOG_WARNING, "Server returned %s status %i %s",
1316 scope, code, buf);
1317 }
1318
1319
1320 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1321 const uint16_t code, const void *status_msg, const int len,
1322 int *ret)
1323 {
1324 dhcpv6_log_status_code(code, "message", status_msg, len);
1325
1326 switch (code) {
1327 case DHCPV6_UnspecFail:
1328 // Generic failure
1329 *ret = 0;
1330 break;
1331
1332 case DHCPV6_UseMulticast:
1333 // TODO handle multicast status code
1334 break;
1335
1336 case DHCPV6_NoAddrsAvail:
1337 case DHCPV6_NoPrefixAvail:
1338 if (orig == DHCPV6_MSG_REQUEST)
1339 *ret = 0; // Failure
1340 break;
1341
1342 default:
1343 break;
1344 }
1345 }
1346
1347
1348 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1349 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1350 const void *status_msg, const int len,
1351 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1352 {
1353 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1354 "IA_NA" : "IA_PD", status_msg, len);
1355
1356 switch (code) {
1357 case DHCPV6_NoBinding:
1358 switch (orig) {
1359 case DHCPV6_MSG_RENEW:
1360 case DHCPV6_MSG_REBIND:
1361 if ((*ret > 0) && !handled_status_codes[code])
1362 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1363 break;
1364
1365 default:
1366 break;
1367 }
1368 break;
1369
1370 default:
1371 *ret = 0;
1372 break;
1373 }
1374 }
1375
1376 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1377 {
1378 size_t cand_len, i;
1379 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1380
1381 // Remove identical duid server candidate
1382 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1383 if (cand->duid_len == c[i].duid_len &&
1384 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1385 free(c[i].ia_na);
1386 free(c[i].ia_pd);
1387 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1388 break;
1389 }
1390 }
1391
1392 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1393 i < cand_len / sizeof(*c); ++i) {
1394 if (c[i].preference < cand->preference)
1395 break;
1396 }
1397
1398 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1399 }
1400
1401 static void dhcpv6_clear_all_server_cand(void)
1402 {
1403 size_t cand_len, i;
1404 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1405
1406 // Server candidates need deep delete for IA_NA/IA_PD
1407 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1408 free(c[i].ia_na);
1409 free(c[i].ia_pd);
1410 }
1411 odhcp6c_clear_state(STATE_SERVER_CAND);
1412 }
1413
1414 int dhcpv6_promote_server_cand(void)
1415 {
1416 size_t cand_len;
1417 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1418 uint16_t hdr[2];
1419 int ret = DHCPV6_STATELESS;
1420
1421 // Clear lingering candidate state info
1422 odhcp6c_clear_state(STATE_SERVER_ID);
1423 odhcp6c_clear_state(STATE_IA_NA);
1424 odhcp6c_clear_state(STATE_IA_PD);
1425
1426 if (!cand_len)
1427 return -1;
1428
1429 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1430 na_mode = IA_MODE_NONE;
1431
1432 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1433 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1434
1435 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1436 }
1437
1438 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1439 hdr[1] = htons(cand->duid_len);
1440 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1441 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1442 accept_reconfig = cand->wants_reconfigure;
1443 if (cand->ia_na_len) {
1444 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1445 free(cand->ia_na);
1446 if (na_mode != IA_MODE_NONE)
1447 ret = DHCPV6_STATEFUL;
1448 }
1449 if (cand->ia_pd_len) {
1450 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1451 free(cand->ia_pd);
1452 if (request_prefix)
1453 ret = DHCPV6_STATEFUL;
1454 }
1455
1456 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1457 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1458
1459 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1460
1461 return ret;
1462 }
Openwrt DHCPv6 Client