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[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 };
183 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
184 }
185
186 // Configure IPv6-options
187 int val = 1;
188 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
189 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
190 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
191 val = 0;
192 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
193
194 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
195 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
196 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
197 return -1;
198
199 return 0;
200 }
201
202 enum {
203 IOV_HDR=0,
204 IOV_ORO,
205 IOV_ORO_REFRESH,
206 IOV_CL_ID,
207 IOV_SRV_ID,
208 IOV_VENDOR_CLASS_HDR,
209 IOV_VENDOR_CLASS,
210 IOV_USER_CLASS_HDR,
211 IOV_USER_CLASS,
212 IOV_RECONF_ACCEPT,
213 IOV_FQDN,
214 IOV_HDR_IA_NA,
215 IOV_IA_NA,
216 IOV_IA_PD,
217 IOV_TOTAL
218 };
219
220 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
221 {
222 na_mode = na;
223 pd_mode = pd;
224 }
225
226 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
227 {
228 // Build FQDN
229 char fqdn_buf[256];
230 gethostname(fqdn_buf, sizeof(fqdn_buf));
231 struct {
232 uint16_t type;
233 uint16_t len;
234 uint8_t flags;
235 uint8_t data[256];
236 } fqdn;
237 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
238 sizeof(fqdn.data), NULL, NULL);
239 fqdn.type = htons(DHCPV6_OPT_FQDN);
240 fqdn.len = htons(fqdn_len - 4);
241 fqdn.flags = 0;
242
243
244 // Build Client ID
245 size_t cl_id_len;
246 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
247
248 // Get Server ID
249 size_t srv_id_len;
250 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
251
252 // Build IA_PDs
253 size_t ia_pd_entries = 0, ia_pd_len = 0;
254 uint8_t *ia_pd;
255
256 if (type == DHCPV6_MSG_SOLICIT) {
257 odhcp6c_clear_state(STATE_IA_PD);
258 size_t n_prefixes;
259 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
260 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
261
262 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
263
264 for (size_t i = 0; i < n_prefixes; i++) {
265 struct dhcpv6_ia_hdr hdr_ia_pd = {
266 htons(DHCPV6_OPT_IA_PD),
267 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
268 request_prefixes[i].iaid, 0, 0
269 };
270 struct dhcpv6_ia_prefix pref = {
271 .type = htons(DHCPV6_OPT_IA_PREFIX),
272 .len = htons(25), .prefix = request_prefixes[i].length
273 };
274 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
275 ia_pd_len += sizeof(hdr_ia_pd);
276 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
277 ia_pd_len += sizeof(pref);
278 }
279 } else {
280 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
281 ia_pd_entries /= sizeof(*e);
282
283 // we're too lazy to count our distinct IAIDs,
284 // so just allocate maximally needed space
285 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
286 sizeof(struct dhcpv6_ia_hdr)));
287
288 for (size_t i = 0; i < ia_pd_entries; ++i) {
289 uint32_t iaid = e[i].iaid;
290
291 // check if this is an unprocessed IAID and skip if not.
292 int new_iaid = 1;
293 for (int j = i-1; j >= 0; j--) {
294 if (e[j].iaid == iaid) {
295 new_iaid = 0;
296 break;
297 }
298 }
299
300 if (!new_iaid)
301 continue;
302
303 // construct header
304 struct dhcpv6_ia_hdr hdr_ia_pd = {
305 htons(DHCPV6_OPT_IA_PD),
306 htons(sizeof(hdr_ia_pd) - 4),
307 iaid, 0, 0
308 };
309
310 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
311 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
312 ia_pd_len += sizeof(hdr_ia_pd);
313
314 for (size_t j = i; j < ia_pd_entries; j++) {
315 if (e[j].iaid != iaid)
316 continue;
317
318 uint8_t ex_len = 0;
319 if (e[j].priority > 0)
320 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
321
322 struct dhcpv6_ia_prefix p = {
323 .type = htons(DHCPV6_OPT_IA_PREFIX),
324 .len = htons(sizeof(p) - 4U + ex_len),
325 .prefix = e[j].length,
326 .addr = e[j].target
327 };
328
329 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
330 ia_pd_len += sizeof(p);
331
332 if (ex_len) {
333 ia_pd[ia_pd_len++] = 0;
334 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
335 ia_pd[ia_pd_len++] = 0;
336 ia_pd[ia_pd_len++] = ex_len - 4;
337 ia_pd[ia_pd_len++] = e[j].priority;
338
339 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
340 excl >>= (64 - e[j].priority);
341 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
342
343 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
344 ia_pd[ia_pd_len + i] = excl & 0xff;
345 ia_pd_len += ex_len - 5;
346 }
347
348 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
349 }
350 }
351 }
352
353 if (ia_pd_entries > 0)
354 request_prefix = 1;
355
356 // Build IA_NAs
357 size_t ia_na_entries, ia_na_len = 0;
358 void *ia_na = NULL;
359 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
360 ia_na_entries /= sizeof(*e);
361
362 struct dhcpv6_ia_hdr hdr_ia_na = {
363 htons(DHCPV6_OPT_IA_NA),
364 htons(sizeof(hdr_ia_na) - 4),
365 1, 0, 0
366 };
367
368 struct dhcpv6_ia_addr pa[ia_na_entries];
369 for (size_t i = 0; i < ia_na_entries; ++i) {
370 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
371 pa[i].len = htons(sizeof(pa[i]) - 4U);
372 pa[i].addr = e[i].target;
373 pa[i].preferred = 0;
374 pa[i].valid = 0;
375 }
376
377 ia_na = pa;
378 ia_na_len = sizeof(pa);
379 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
380
381 // Reconfigure Accept
382 struct {
383 uint16_t type;
384 uint16_t length;
385 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
386
387 // Request Information Refresh
388 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
389
390 // Build vendor-class option
391 size_t vendor_class_len, user_class_len;
392 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
393 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
394
395 struct {
396 uint16_t type;
397 uint16_t length;
398 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
399
400 struct {
401 uint16_t type;
402 uint16_t length;
403 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
404
405 // Prepare Header
406 size_t oro_len;
407 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
408 struct {
409 uint8_t type;
410 uint8_t trid[3];
411 uint16_t elapsed_type;
412 uint16_t elapsed_len;
413 uint16_t elapsed_value;
414 uint16_t oro_type;
415 uint16_t oro_len;
416 } hdr = {
417 type, {trid[0], trid[1], trid[2]},
418 htons(DHCPV6_OPT_ELAPSED), htons(2),
419 htons((ecs > 0xffff) ? 0xffff : ecs),
420 htons(DHCPV6_OPT_ORO), htons(oro_len),
421 };
422
423 struct iovec iov[IOV_TOTAL] = {
424 [IOV_HDR] = {&hdr, sizeof(hdr)},
425 [IOV_ORO] = {oro, oro_len},
426 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
427 [IOV_CL_ID] = {cl_id, cl_id_len},
428 [IOV_SRV_ID] = {srv_id, srv_id_len},
429 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
430 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
431 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
432 [IOV_USER_CLASS] = {user_class, user_class_len},
433 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
434 [IOV_FQDN] = {&fqdn, fqdn_len},
435 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
436 [IOV_IA_NA] = {ia_na, ia_na_len},
437 [IOV_IA_PD] = {ia_pd, ia_pd_len},
438 };
439
440 size_t cnt = IOV_TOTAL;
441 if (type == DHCPV6_MSG_INFO_REQ) {
442 cnt = 9;
443 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
444 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
445 } else if (!request_prefix) {
446 cnt = 13;
447 }
448
449 // Disable IAs if not used
450 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
451 iov[IOV_HDR_IA_NA].iov_len = 0;
452
453 if (na_mode == IA_MODE_NONE)
454 iov[IOV_HDR_IA_NA].iov_len = 0;
455
456 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
457 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
458 iov[IOV_RECONF_ACCEPT].iov_len = 0;
459
460 if (!(client_options & DHCPV6_CLIENT_FQDN))
461 iov[IOV_FQDN].iov_len = 0;
462
463 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
464 0, ALL_DHCPV6_RELAYS, ifindex};
465 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
466
467 sendmsg(sock, &msg, 0);
468 }
469
470
471 static int64_t dhcpv6_rand_delay(int64_t time)
472 {
473 int random;
474 odhcp6c_random(&random, sizeof(random));
475 return (time * ((int64_t)random % 1000LL)) / 10000LL;
476 }
477
478
479 int dhcpv6_request(enum dhcpv6_msg type)
480 {
481 uint8_t rc = 0;
482 uint64_t timeout = UINT32_MAX;
483 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
484
485 if (retx->delay) {
486 struct timespec ts = {0, 0};
487 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
488 nanosleep(&ts, NULL);
489 }
490
491 if (type == DHCPV6_MSG_UNKNOWN)
492 timeout = t1;
493 else if (type == DHCPV6_MSG_RENEW)
494 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
495 else if (type == DHCPV6_MSG_REBIND)
496 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
497
498 if (timeout == 0)
499 return -1;
500
501 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
502 retx->name, (unsigned long long)timeout, retx->max_rc);
503
504 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
505
506 // Generate transaction ID
507 uint8_t trid[3] = {0, 0, 0};
508 if (type != DHCPV6_MSG_UNKNOWN)
509 odhcp6c_random(trid, sizeof(trid));
510 ssize_t len = -1;
511 int64_t rto = 0;
512
513 do {
514 if (rto == 0) {
515 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
516
517 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
518 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
519 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
520
521 rto = (retx->init_timeo * 1000 + delay);
522 }
523 else
524 rto = (2 * rto + dhcpv6_rand_delay(rto));
525
526 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
527 rto = retx->max_timeo * 1000 +
528 dhcpv6_rand_delay(retx->max_timeo * 1000);
529
530 // Calculate end for this round and elapsed time
531 uint64_t round_end = round_start + rto;
532 elapsed = round_start - start;
533
534 // Don't wait too long if timeout differs from infinite
535 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
536 round_end = timeout * 1000 + start;
537
538 // Built and send package
539 if (type != DHCPV6_MSG_UNKNOWN) {
540 if (type != DHCPV6_MSG_SOLICIT)
541 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
542 retx->name, (unsigned long long)elapsed, rc);
543 dhcpv6_send(type, trid, elapsed / 10);
544 rc++;
545 }
546
547 // Receive rounds
548 for (; len < 0 && (round_start < round_end);
549 round_start = odhcp6c_get_milli_time()) {
550 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
551 struct iovec iov = {buf, sizeof(buf)};
552 struct msghdr msg = {NULL, 0, &iov, 1,
553 cmsg_buf, sizeof(cmsg_buf), 0};
554 struct in6_pktinfo *pktinfo = NULL;
555
556 // Check for pending signal
557 if (odhcp6c_signal_process())
558 return -1;
559
560 // Set timeout for receiving
561 uint64_t t = round_end - round_start;
562 struct timeval tv = {t / 1000, (t % 1000) * 1000};
563 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
564 &tv, sizeof(tv));
565
566 // Receive cycle
567 len = recvmsg(sock, &msg, 0);
568 if (len < 0)
569 continue;
570
571 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
572 ch = CMSG_NXTHDR(&msg, ch)) {
573 if (ch->cmsg_level == SOL_IPV6 &&
574 ch->cmsg_type == IPV6_PKTINFO) {
575 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
576 break;
577 }
578 }
579
580 if (pktinfo == NULL) {
581 len = -1;
582 continue;
583 }
584
585 if (!dhcpv6_response_is_valid(buf, len, trid,
586 type, &pktinfo->ipi6_addr)) {
587 len = -1;
588 continue;
589 }
590
591 uint8_t *opt = &buf[4];
592 uint8_t *opt_end = opt + len - 4;
593
594 round_start = odhcp6c_get_milli_time();
595 elapsed = round_start - start;
596 syslog(LOG_NOTICE, "Got a valid reply after "
597 "%llums", (unsigned long long)elapsed);
598
599 if (retx->handler_reply)
600 len = retx->handler_reply(type, rc, opt, opt_end);
601
602 if (len > 0 && round_end - round_start > 1000)
603 round_end = 1000 + round_start;
604 }
605
606 // Allow
607 if (retx->handler_finish)
608 len = retx->handler_finish();
609 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
610 (!retx->max_rc || rc < retx->max_rc));
611 return len;
612 }
613
614 // Message validation checks according to RFC3315 chapter 15
615 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
616 const uint8_t transaction[3], enum dhcpv6_msg type,
617 const struct in6_addr *daddr)
618 {
619 const struct dhcpv6_header *rep = buf;
620 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
621 transaction, sizeof(rep->tr_id)))
622 return false; // Invalid reply
623
624 if (type == DHCPV6_MSG_SOLICIT) {
625 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
626 rep->msg_type != DHCPV6_MSG_REPLY)
627 return false;
628 } else if (type == DHCPV6_MSG_UNKNOWN) {
629 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
630 return false;
631 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
632 return false;
633 }
634
635 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
636 rcmsg = DHCPV6_MSG_UNKNOWN;
637 uint16_t otype, olen = UINT16_MAX;
638 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
639 ia_present = false, options_valid = true;
640
641 size_t client_id_len, server_id_len;
642 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
643 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
644
645 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
646 if (otype == DHCPV6_OPT_CLIENTID) {
647 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
648 &odata[-4], client_id, client_id_len);
649 } else if (otype == DHCPV6_OPT_SERVERID) {
650 if (server_id_len)
651 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
652 &odata[-4], server_id, server_id_len);
653 else
654 serverid_ok = true;
655 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
656 sizeof(struct dhcpv6_auth_reconfigure)) {
657 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
658 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
659 continue;
660
661 md5_ctx_t md5;
662 uint8_t serverhash[16], secretbytes[64], hash[16];
663 memcpy(serverhash, r->key, sizeof(serverhash));
664 memset(r->key, 0, sizeof(r->key));
665
666 memset(secretbytes, 0, sizeof(secretbytes));
667 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
668
669 for (size_t i = 0; i < sizeof(secretbytes); ++i)
670 secretbytes[i] ^= 0x36;
671
672 md5_begin(&md5);
673 md5_hash(secretbytes, sizeof(secretbytes), &md5);
674 md5_hash(buf, len, &md5);
675 md5_end(hash, &md5);
676
677 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
678 secretbytes[i] ^= 0x36;
679 secretbytes[i] ^= 0x5c;
680 }
681
682 md5_begin(&md5);
683 md5_hash(secretbytes, sizeof(secretbytes), &md5);
684 md5_hash(hash, 16, &md5);
685 md5_end(hash, &md5);
686
687 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
688 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
689 rcmsg = odata[0];
690 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
691 ia_present = true;
692 if (olen < sizeof(struct dhcpv6_ia_hdr))
693 options_valid = false;
694 }
695 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
696 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
697 // Options are not allowed on global level
698 options_valid = false;
699 }
700 }
701
702 if (!options_valid || ((odata + olen) > end))
703 return false;
704
705 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
706 return false;
707
708 if (rep->msg_type == DHCPV6_MSG_RECONF) {
709 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
710 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
711 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
712 return false;
713 }
714
715 return clientid_ok && serverid_ok;
716 }
717
718
719 int dhcpv6_poll_reconfigure(void)
720 {
721 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
722 if (ret != -1)
723 ret = dhcpv6_request(ret);
724
725 return ret;
726 }
727
728
729 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
730 const void *opt, const void *end)
731 {
732 uint16_t otype, olen;
733 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
734 dhcpv6_for_each_option(opt, end, otype, olen, odata)
735 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
736 odata[0] == DHCPV6_MSG_RENEW ||
737 odata[0] == DHCPV6_MSG_INFO_REQ))
738 msg = odata[0];
739
740 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
741 return msg;
742 }
743
744
745 // Collect all advertised servers
746 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
747 const void *opt, const void *end)
748 {
749 uint16_t olen, otype;
750 uint8_t *odata, pref = 0;
751 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
752 DHCPV6_SOL_MAX_RT,
753 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
754 bool have_na = false;
755 int have_pd = 0;
756
757 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
758 if (orig == DHCPV6_MSG_SOLICIT &&
759 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
760 olen > sizeof(struct dhcpv6_ia_hdr)) {
761 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
762 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
763 }
764
765 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
766 memcpy(cand.duid, odata, olen);
767 cand.duid_len = olen;
768 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
769 int error = ((int)odata[0] << 8 | (int)odata[1]);
770
771 switch (error) {
772 case DHCPV6_NoPrefixAvail:
773 // Status code on global level
774 cand.preference -= 2000;
775 break;
776
777 default :
778 break;
779 }
780 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
781 cand.preference >= 0) {
782 cand.preference = pref = odata[0];
783 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
784 cand.wants_reconfigure = true;
785 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
786 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
787 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
788 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
789 cand.sol_max_rt = sol_max_rt;
790 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
791 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
792 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
793 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
794 cand.inf_max_rt = inf_max_rt;
795 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
796 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
797 uint8_t *oend = odata + olen, *d;
798 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
799 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
800 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
801 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
802 have_pd = p->prefix;
803 }
804 }
805 } else if (otype == DHCPV6_OPT_IA_NA) {
806 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
807 uint8_t *oend = odata + olen, *d;
808 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
809 if (otype == DHCPV6_OPT_IA_ADDR)
810 have_na = true;
811 }
812 }
813
814 if ((!have_na && na_mode == IA_MODE_FORCE) ||
815 (!have_pd && pd_mode == IA_MODE_FORCE)) {
816 /*
817 * RFC7083 states to process the SOL_MAX_RT and
818 * INF_MAX_RT options even if the DHCPv6 server
819 * did not propose any IA_NA and/or IA_PD
820 */
821 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
822 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
823 return -1;
824 }
825
826 if (na_mode != IA_MODE_NONE && !have_na) {
827 cand.has_noaddravail = true;
828 cand.preference -= 1000;
829 }
830
831 if (pd_mode != IA_MODE_NONE) {
832 if (have_pd)
833 cand.preference += 2000 + (128 - have_pd);
834 else
835 cand.preference -= 2000;
836 }
837
838 if (cand.duid_len > 0) {
839 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
840 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
841 dhcpv6_add_server_cand(&cand);
842 }
843
844 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
845 }
846
847
848 static int dhcpv6_commit_advert(void)
849 {
850 return dhcpv6_promote_server_cand();
851 }
852
853
854 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
855 const void *opt, const void *end)
856 {
857 dhcpv6_handle_advert(orig, rc, opt, end);
858 if (dhcpv6_commit_advert() < 0)
859 return -1;
860
861 return dhcpv6_handle_reply(orig, rc, opt, end);
862 }
863
864
865 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
866 const void *opt, const void *end)
867 {
868 uint8_t *odata;
869 uint16_t otype, olen;
870 uint32_t refresh = UINT32_MAX;
871 int ret = 1;
872 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
873
874 odhcp6c_expire();
875
876 if (orig == DHCPV6_MSG_UNKNOWN) {
877 static time_t last_update = 0;
878 time_t now = odhcp6c_get_milli_time() / 1000;
879
880 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
881 last_update = now;
882
883 if (t1 != UINT32_MAX)
884 t1 -= elapsed;
885
886 if (t2 != UINT32_MAX)
887 t2 -= elapsed;
888
889 if (t3 != UINT32_MAX)
890 t3 -= elapsed;
891
892 if (t1 < 0)
893 t1 = 0;
894
895 if (t2 < 0)
896 t2 = 0;
897
898 if (t3 < 0)
899 t3 = 0;
900 }
901
902 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
903 // Delete NA and PD we have in the state from the Advert
904 odhcp6c_clear_state(STATE_IA_NA);
905 odhcp6c_clear_state(STATE_IA_PD);
906 }
907
908 if (opt) {
909 odhcp6c_clear_state(STATE_DNS);
910 odhcp6c_clear_state(STATE_SEARCH);
911 odhcp6c_clear_state(STATE_SNTP_IP);
912 odhcp6c_clear_state(STATE_NTP_IP);
913 odhcp6c_clear_state(STATE_NTP_FQDN);
914 odhcp6c_clear_state(STATE_SIP_IP);
915 odhcp6c_clear_state(STATE_SIP_FQDN);
916 odhcp6c_clear_state(STATE_AFTR_NAME);
917 }
918
919 // Parse and find all matching IAs
920 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
921 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
922 && olen > sizeof(struct dhcpv6_ia_hdr)) {
923 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
924
925 // Test ID
926 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
927 continue;
928
929 uint16_t code = DHCPV6_Success;
930 uint16_t stype, slen;
931 uint8_t *sdata;
932 // Get and handle status code
933 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
934 stype, slen, sdata) {
935 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
936 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
937 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
938
939 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
940
941 if (code == DHCPV6_Success)
942 continue;
943
944 dhcpv6_handle_ia_status_code(orig, ia_hdr,
945 code, mdata, mlen, handled_status_codes, &ret);
946
947
948 if (ret > 0)
949 return ret;
950 break;
951 }
952 }
953
954 if (code != DHCPV6_Success)
955 continue;
956
957 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
958 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
959 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
960 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
961 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
962
963 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
964 }
965 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
966 if (olen % 16 == 0)
967 odhcp6c_add_state(STATE_DNS, odata, olen);
968 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
969 odhcp6c_add_state(STATE_SEARCH, odata, olen);
970 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
971 if (olen % 16 == 0)
972 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
973 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
974 uint16_t stype, slen;
975 uint8_t *sdata;
976 // Test status and bail if error
977 dhcpv6_for_each_option(odata, odata + olen,
978 stype, slen, sdata) {
979 if (slen == 16 && (stype == NTP_MC_ADDR ||
980 stype == NTP_SRV_ADDR))
981 odhcp6c_add_state(STATE_NTP_IP,
982 sdata, slen);
983 else if (slen > 0 && stype == NTP_SRV_FQDN)
984 odhcp6c_add_state(STATE_NTP_FQDN,
985 sdata, slen);
986 }
987 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
988 if (olen == 16)
989 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
990 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
991 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
992 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
993 refresh = ntohl(*((uint32_t*)odata));
994 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
995 sizeof(struct dhcpv6_auth_reconfigure)) {
996 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
997 if (r->protocol == 3 && r->algorithm == 1 &&
998 r->reconf_type == 1)
999 memcpy(reconf_key, r->key, sizeof(r->key));
1000 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1001 size_t cur_len;
1002 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1003 if (cur_len == 0)
1004 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1005 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1006 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
1007 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1008 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1009 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1010 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1011 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
1012 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1013 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1014 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1015 #ifdef EXT_CER_ID
1016 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1017 sizeof(struct dhcpv6_cer_id)) {
1018 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1019 struct in6_addr any = IN6ADDR_ANY_INIT;
1020 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1021 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1022 #endif
1023 } else if (otype != DHCPV6_OPT_CLIENTID &&
1024 otype != DHCPV6_OPT_SERVERID) {
1025 odhcp6c_add_state(STATE_CUSTOM_OPTS,
1026 &odata[-4], olen + 4);
1027 }
1028 }
1029
1030 if (orig != DHCPV6_MSG_INFO_REQ) {
1031 // Update refresh timers if no fatal status code was received
1032 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1033 switch (orig) {
1034 case DHCPV6_MSG_RENEW:
1035 // Send further renews if T1 is not set
1036 if (!t1)
1037 ret = -1;
1038 break;
1039 case DHCPV6_MSG_REBIND:
1040 // Send further rebinds if T1 and T2 is not set
1041 if (!t1 && !t2)
1042 ret = -1;
1043 break;
1044
1045 case DHCPV6_MSG_REQUEST:
1046 // All server candidates can be cleared if not yet bound
1047 if (!odhcp6c_is_bound())
1048 dhcpv6_clear_all_server_cand();
1049
1050 default :
1051 break;
1052 }
1053 }
1054 }
1055 else if (ret > 0) {
1056 // All server candidates can be cleared if not yet bound
1057 if (!odhcp6c_is_bound())
1058 dhcpv6_clear_all_server_cand();
1059
1060 t1 = refresh;
1061 }
1062
1063 return ret;
1064 }
1065
1066
1067 static int dhcpv6_parse_ia(void *opt, void *end)
1068 {
1069 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1070 int parsed_ia = 0;
1071 uint32_t t1, t2;
1072 uint16_t otype, olen;
1073 uint8_t *odata;
1074
1075 t1 = ntohl(ia_hdr->t1);
1076 t2 = ntohl(ia_hdr->t2);
1077
1078 if (t1 > t2)
1079 return 0;
1080
1081 // Update address IA
1082 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1083 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1084 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1085
1086 entry.iaid = ia_hdr->iaid;
1087
1088 if (otype == DHCPV6_OPT_IA_PREFIX) {
1089 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1090 if (olen + 4U < sizeof(*prefix))
1091 continue;
1092
1093 entry.valid = ntohl(prefix->valid);
1094 entry.preferred = ntohl(prefix->preferred);
1095
1096 if (entry.preferred > entry.valid)
1097 continue;
1098
1099 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1100 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1101 if (entry.t1 > entry.t2)
1102 entry.t1 = entry.t2;
1103
1104 entry.length = prefix->prefix;
1105 entry.target = prefix->addr;
1106 uint16_t stype, slen;
1107 uint8_t *sdata;
1108
1109 #ifdef EXT_PREFIX_CLASS
1110 // Find prefix class, if any
1111 dhcpv6_for_each_option(&prefix[1], odata + olen,
1112 stype, slen, sdata)
1113 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1114 entry.class = sdata[0] << 8 | sdata[1];
1115 #endif
1116
1117 // Parse PD-exclude
1118 bool ok = true;
1119 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1120 odata + olen, stype, slen, sdata) {
1121 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1122 continue;
1123
1124 uint8_t elen = sdata[0];
1125 if (elen > 64)
1126 elen = 64;
1127
1128 if (elen <= 32 || elen <= entry.length) {
1129 ok = false;
1130 continue;
1131 }
1132
1133
1134 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1135 if (slen <= bytes) {
1136 ok = false;
1137 continue;
1138 }
1139
1140 uint32_t exclude = 0;
1141 do {
1142 exclude = exclude << 8 | sdata[bytes];
1143 } while (--bytes);
1144
1145 exclude >>= 8 - ((elen - entry.length) % 8);
1146 exclude <<= 64 - elen;
1147
1148 // Abusing router & priority fields for exclusion
1149 entry.router = entry.target;
1150 entry.router.s6_addr32[1] |= htonl(exclude);
1151 entry.priority = elen;
1152 }
1153
1154 if (ok) {
1155 odhcp6c_update_entry(STATE_IA_PD, &entry);
1156 parsed_ia++;
1157 }
1158
1159 entry.priority = 0;
1160 memset(&entry.router, 0, sizeof(entry.router));
1161 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1162 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1163 if (olen + 4U < sizeof(*addr))
1164 continue;
1165
1166 entry.preferred = ntohl(addr->preferred);
1167 entry.valid = ntohl(addr->valid);
1168
1169 if (entry.preferred > entry.valid)
1170 continue;
1171
1172 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1173 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1174 if (entry.t1 > entry.t2)
1175 entry.t1 = entry.t2;
1176
1177 entry.length = 128;
1178 entry.target = addr->addr;
1179
1180 #ifdef EXT_PREFIX_CLASS
1181 uint16_t stype, slen;
1182 uint8_t *sdata;
1183 // Find prefix class, if any
1184 dhcpv6_for_each_option(&addr[1], odata + olen,
1185 stype, slen, sdata)
1186 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1187 entry.class = sdata[0] << 8 | sdata[1];
1188 #endif
1189
1190 odhcp6c_update_entry(STATE_IA_NA, &entry);
1191 parsed_ia++;
1192 }
1193 }
1194 return parsed_ia;
1195 }
1196
1197
1198 static int dhcpv6_calc_refresh_timers(void)
1199 {
1200 struct odhcp6c_entry *e;
1201 size_t ia_na_entries, ia_pd_entries, i;
1202 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1203
1204 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1205 ia_na_entries /= sizeof(*e);
1206 for (i = 0; i < ia_na_entries; i++) {
1207 if (e[i].t1 < l_t1)
1208 l_t1 = e[i].t1;
1209
1210 if (e[i].t2 < l_t2)
1211 l_t2 = e[i].t2;
1212
1213 if (e[i].valid > l_t3)
1214 l_t3 = e[i].valid;
1215 }
1216
1217 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1218 ia_pd_entries /= sizeof(*e);
1219 for (i = 0; i < ia_pd_entries; i++) {
1220 if (e[i].t1 < l_t1)
1221 l_t1 = e[i].t1;
1222
1223 if (e[i].t2 < l_t2)
1224 l_t2 = e[i].t2;
1225
1226 if (e[i].valid > l_t3)
1227 l_t3 = e[i].valid;
1228 }
1229
1230 if (ia_pd_entries || ia_na_entries) {
1231 t1 = l_t1;
1232 t2 = l_t2;
1233 t3 = l_t3;
1234 } else {
1235 t1 = 600;
1236 }
1237
1238 return (int)(ia_pd_entries + ia_na_entries);
1239 }
1240
1241
1242 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1243 const void *status_msg, const int len)
1244 {
1245 uint8_t buf[len + 3];
1246
1247 memset(buf, 0, sizeof(buf));
1248 if (len) {
1249 buf[0] = '(';
1250 memcpy(&buf[1], status_msg, len);
1251 buf[len + 1] = ')';
1252 }
1253
1254 syslog(LOG_WARNING, "Server returned %s status %i %s",
1255 scope, code, buf);
1256 }
1257
1258
1259 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1260 const uint16_t code, const void *status_msg, const int len,
1261 int *ret)
1262 {
1263 dhcpv6_log_status_code(code, "message", status_msg, len);
1264
1265 switch (code) {
1266 case DHCPV6_UnspecFail:
1267 // Generic failure
1268 *ret = 0;
1269 break;
1270
1271 case DHCPV6_UseMulticast:
1272 // TODO handle multicast status code
1273 break;
1274
1275 case DHCPV6_NoAddrsAvail:
1276 case DHCPV6_NoPrefixAvail:
1277 if (orig == DHCPV6_MSG_REQUEST)
1278 *ret = 0; // Failure
1279 break;
1280
1281 default:
1282 break;
1283 }
1284 }
1285
1286
1287 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1288 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1289 const void *status_msg, const int len,
1290 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1291 {
1292 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1293 "IA_NA" : "IA_PD", status_msg, len);
1294
1295 switch (code) {
1296 case DHCPV6_NoBinding:
1297 switch (orig) {
1298 case DHCPV6_MSG_RENEW:
1299 case DHCPV6_MSG_REBIND:
1300 if ((*ret > 0) && !handled_status_codes[code])
1301 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1302 break;
1303
1304 default:
1305 break;
1306 }
1307 break;
1308
1309 case DHCPV6_NoAddrsAvail:
1310 case DHCPV6_NoPrefixAvail:
1311 switch (orig) {
1312 case DHCPV6_MSG_REQUEST:
1313 if (*ret != 0)
1314 *ret = 0;
1315 break;
1316 default:
1317 break;
1318 }
1319 break;
1320
1321 case DHCPV6_NotOnLink:
1322 // TODO handle not onlink in case of confirm
1323 break;
1324
1325 default:
1326 break;
1327 }
1328 }
1329
1330 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1331 {
1332 size_t cand_len, i;
1333 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1334
1335 // Remove identical duid server candidate
1336 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1337 if (cand->duid_len == c[i].duid_len &&
1338 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1339 free(c[i].ia_na);
1340 free(c[i].ia_pd);
1341 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1342 break;
1343 }
1344 }
1345
1346 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1347 i < cand_len / sizeof(*c); ++i) {
1348 if (c[i].preference < cand->preference)
1349 break;
1350 }
1351
1352 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1353 }
1354
1355 static void dhcpv6_clear_all_server_cand(void)
1356 {
1357 size_t cand_len, i;
1358 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1359
1360 // Server candidates need deep delete for IA_NA/IA_PD
1361 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1362 free(c[i].ia_na);
1363 free(c[i].ia_pd);
1364 }
1365 odhcp6c_clear_state(STATE_SERVER_CAND);
1366 }
1367
1368 int dhcpv6_promote_server_cand(void)
1369 {
1370 size_t cand_len;
1371 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1372 uint16_t hdr[2];
1373 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1374 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1375
1376 // Clear lingering candidate state info
1377 odhcp6c_clear_state(STATE_SERVER_ID);
1378 odhcp6c_clear_state(STATE_IA_NA);
1379 odhcp6c_clear_state(STATE_IA_PD);
1380
1381 if (!cand_len)
1382 return -1;
1383
1384 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1385 na_mode = IA_MODE_NONE;
1386
1387 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1388 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1389
1390 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1391 }
1392
1393 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1394 hdr[1] = htons(cand->duid_len);
1395 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1396 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1397 accept_reconfig = cand->wants_reconfigure;
1398 if (cand->ia_na_len) {
1399 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1400 free(cand->ia_na);
1401 if (na_mode != IA_MODE_NONE)
1402 ret = DHCPV6_STATEFUL;
1403 }
1404 if (cand->ia_pd_len) {
1405 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1406 free(cand->ia_pd);
1407 if (request_prefix)
1408 ret = DHCPV6_STATEFUL;
1409 }
1410
1411 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1412 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1413
1414 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1415
1416 return ret;
1417 }
Openwrt DHCPv6 Client