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Add initial support for CER-ID
[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, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
193 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
194
195 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
196 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
197 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
198 return -1;
199
200 return 0;
201 }
202
203 enum {
204 IOV_HDR=0,
205 IOV_ORO,
206 IOV_ORO_REFRESH,
207 IOV_CL_ID,
208 IOV_SRV_ID,
209 IOV_VENDOR_CLASS_HDR,
210 IOV_VENDOR_CLASS,
211 IOV_USER_CLASS_HDR,
212 IOV_USER_CLASS,
213 IOV_RECONF_ACCEPT,
214 IOV_FQDN,
215 IOV_HDR_IA_NA,
216 IOV_IA_NA,
217 IOV_IA_PD,
218 IOV_TOTAL
219 };
220
221 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
222 {
223 na_mode = na;
224 pd_mode = pd;
225 }
226
227 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
228 {
229 // Build FQDN
230 char fqdn_buf[256];
231 gethostname(fqdn_buf, sizeof(fqdn_buf));
232 struct {
233 uint16_t type;
234 uint16_t len;
235 uint8_t flags;
236 uint8_t data[256];
237 } fqdn;
238 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
239 sizeof(fqdn.data), NULL, NULL);
240 fqdn.type = htons(DHCPV6_OPT_FQDN);
241 fqdn.len = htons(fqdn_len - 4);
242 fqdn.flags = 0;
243
244
245 // Build Client ID
246 size_t cl_id_len;
247 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
248
249 // Get Server ID
250 size_t srv_id_len;
251 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
252
253 // Build IA_PDs
254 size_t ia_pd_entries = 0, ia_pd_len = 0;
255 uint8_t *ia_pd;
256
257 if (type == DHCPV6_MSG_SOLICIT) {
258 odhcp6c_clear_state(STATE_IA_PD);
259 size_t n_prefixes;
260 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
261 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
262
263 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
264
265 for (size_t i = 0; i < n_prefixes; i++) {
266 struct dhcpv6_ia_hdr hdr_ia_pd = {
267 htons(DHCPV6_OPT_IA_PD),
268 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
269 request_prefixes[i].iaid, 0, 0
270 };
271 struct dhcpv6_ia_prefix pref = {
272 .type = htons(DHCPV6_OPT_IA_PREFIX),
273 .len = htons(25), .prefix = request_prefixes[i].length
274 };
275 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
276 ia_pd_len += sizeof(hdr_ia_pd);
277 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
278 ia_pd_len += sizeof(pref);
279 }
280 } else {
281 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
282 ia_pd_entries /= sizeof(*e);
283
284 // we're too lazy to count our distinct IAIDs,
285 // so just allocate maximally needed space
286 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
287 sizeof(struct dhcpv6_ia_hdr)));
288
289 for (size_t i = 0; i < ia_pd_entries; ++i) {
290 uint32_t iaid = e[i].iaid;
291
292 // check if this is an unprocessed IAID and skip if not.
293 int new_iaid = 1;
294 for (int j = i-1; j >= 0; j--) {
295 if (e[j].iaid == iaid) {
296 new_iaid = 0;
297 break;
298 }
299 }
300
301 if (!new_iaid)
302 continue;
303
304 // construct header
305 struct dhcpv6_ia_hdr hdr_ia_pd = {
306 htons(DHCPV6_OPT_IA_PD),
307 htons(sizeof(hdr_ia_pd) - 4),
308 iaid, 0, 0
309 };
310
311 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
312 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
313 ia_pd_len += sizeof(hdr_ia_pd);
314
315 for (size_t j = i; j < ia_pd_entries; j++) {
316 if (e[j].iaid != iaid)
317 continue;
318
319 uint8_t ex_len = 0;
320 if (e[j].priority > 0)
321 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
322
323 struct dhcpv6_ia_prefix p = {
324 .type = htons(DHCPV6_OPT_IA_PREFIX),
325 .len = htons(sizeof(p) - 4U + ex_len),
326 .prefix = e[j].length,
327 .addr = e[j].target
328 };
329
330 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
331 ia_pd_len += sizeof(p);
332
333 if (ex_len) {
334 ia_pd[ia_pd_len++] = 0;
335 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
336 ia_pd[ia_pd_len++] = 0;
337 ia_pd[ia_pd_len++] = ex_len - 4;
338 ia_pd[ia_pd_len++] = e[j].priority;
339
340 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
341 excl >>= (64 - e[j].priority);
342 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
343
344 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
345 ia_pd[ia_pd_len + i] = excl & 0xff;
346 ia_pd_len += ex_len - 5;
347 }
348
349 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
350 }
351 }
352 }
353
354 if (ia_pd_entries > 0)
355 request_prefix = 1;
356
357 // Build IA_NAs
358 size_t ia_na_entries, ia_na_len = 0;
359 void *ia_na = NULL;
360 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
361 ia_na_entries /= sizeof(*e);
362
363 struct dhcpv6_ia_hdr hdr_ia_na = {
364 htons(DHCPV6_OPT_IA_NA),
365 htons(sizeof(hdr_ia_na) - 4),
366 1, 0, 0
367 };
368
369 struct dhcpv6_ia_addr pa[ia_na_entries];
370 for (size_t i = 0; i < ia_na_entries; ++i) {
371 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
372 pa[i].len = htons(sizeof(pa[i]) - 4U);
373 pa[i].addr = e[i].target;
374 pa[i].preferred = 0;
375 pa[i].valid = 0;
376 }
377
378 ia_na = pa;
379 ia_na_len = sizeof(pa);
380 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
381
382 // Reconfigure Accept
383 struct {
384 uint16_t type;
385 uint16_t length;
386 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
387
388 // Request Information Refresh
389 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
390
391 // Build vendor-class option
392 size_t vendor_class_len, user_class_len;
393 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
394 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
395
396 struct {
397 uint16_t type;
398 uint16_t length;
399 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
400
401 struct {
402 uint16_t type;
403 uint16_t length;
404 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
405
406 // Prepare Header
407 size_t oro_len;
408 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
409 struct {
410 uint8_t type;
411 uint8_t trid[3];
412 uint16_t elapsed_type;
413 uint16_t elapsed_len;
414 uint16_t elapsed_value;
415 uint16_t oro_type;
416 uint16_t oro_len;
417 } hdr = {
418 type, {trid[0], trid[1], trid[2]},
419 htons(DHCPV6_OPT_ELAPSED), htons(2),
420 htons((ecs > 0xffff) ? 0xffff : ecs),
421 htons(DHCPV6_OPT_ORO), htons(oro_len),
422 };
423
424 struct iovec iov[IOV_TOTAL] = {
425 [IOV_HDR] = {&hdr, sizeof(hdr)},
426 [IOV_ORO] = {oro, oro_len},
427 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
428 [IOV_CL_ID] = {cl_id, cl_id_len},
429 [IOV_SRV_ID] = {srv_id, srv_id_len},
430 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
431 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
432 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
433 [IOV_USER_CLASS] = {user_class, user_class_len},
434 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
435 [IOV_FQDN] = {&fqdn, fqdn_len},
436 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
437 [IOV_IA_NA] = {ia_na, ia_na_len},
438 [IOV_IA_PD] = {ia_pd, ia_pd_len},
439 };
440
441 size_t cnt = IOV_TOTAL;
442 if (type == DHCPV6_MSG_INFO_REQ) {
443 cnt = 9;
444 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
445 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
446 } else if (!request_prefix) {
447 cnt = 13;
448 }
449
450 // Disable IAs if not used
451 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
452 iov[IOV_HDR_IA_NA].iov_len = 0;
453
454 if (na_mode == IA_MODE_NONE)
455 iov[IOV_HDR_IA_NA].iov_len = 0;
456
457 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
458 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
459 iov[IOV_RECONF_ACCEPT].iov_len = 0;
460
461 if (!(client_options & DHCPV6_CLIENT_FQDN))
462 iov[IOV_FQDN].iov_len = 0;
463
464 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
465 0, ALL_DHCPV6_RELAYS, ifindex};
466 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
467
468 sendmsg(sock, &msg, 0);
469 }
470
471
472 static int64_t dhcpv6_rand_delay(int64_t time)
473 {
474 int random;
475 odhcp6c_random(&random, sizeof(random));
476 return (time * ((int64_t)random % 1000LL)) / 10000LL;
477 }
478
479
480 int dhcpv6_request(enum dhcpv6_msg type)
481 {
482 uint8_t rc = 0;
483 uint64_t timeout = UINT32_MAX;
484 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
485
486 if (retx->delay) {
487 struct timespec ts = {0, 0};
488 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
489 nanosleep(&ts, NULL);
490 }
491
492 if (type == DHCPV6_MSG_UNKNOWN)
493 timeout = t1;
494 else if (type == DHCPV6_MSG_RENEW)
495 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
496 else if (type == DHCPV6_MSG_REBIND)
497 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
498
499 if (timeout == 0)
500 return -1;
501
502 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
503 retx->name, (unsigned long long)timeout, retx->max_rc);
504
505 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
506
507 // Generate transaction ID
508 uint8_t trid[3] = {0, 0, 0};
509 if (type != DHCPV6_MSG_UNKNOWN)
510 odhcp6c_random(trid, sizeof(trid));
511 ssize_t len = -1;
512 int64_t rto = 0;
513
514 do {
515 if (rto == 0) {
516 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
517
518 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
519 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
520 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
521
522 rto = (retx->init_timeo * 1000 + delay);
523 }
524 else
525 rto = (2 * rto + dhcpv6_rand_delay(rto));
526
527 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
528 rto = retx->max_timeo * 1000 +
529 dhcpv6_rand_delay(retx->max_timeo * 1000);
530
531 // Calculate end for this round and elapsed time
532 uint64_t round_end = round_start + rto;
533 elapsed = round_start - start;
534
535 // Don't wait too long if timeout differs from infinite
536 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
537 round_end = timeout * 1000 + start;
538
539 // Built and send package
540 if (type != DHCPV6_MSG_UNKNOWN) {
541 if (type != DHCPV6_MSG_SOLICIT)
542 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
543 retx->name, (unsigned long long)elapsed, rc);
544 dhcpv6_send(type, trid, elapsed / 10);
545 rc++;
546 }
547
548 // Receive rounds
549 for (; len < 0 && (round_start < round_end);
550 round_start = odhcp6c_get_milli_time()) {
551 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
552 struct iovec iov = {buf, sizeof(buf)};
553 struct msghdr msg = {NULL, 0, &iov, 1,
554 cmsg_buf, sizeof(cmsg_buf), 0};
555 struct in6_pktinfo *pktinfo = NULL;
556
557 // Check for pending signal
558 if (odhcp6c_signal_process())
559 return -1;
560
561 // Set timeout for receiving
562 uint64_t t = round_end - round_start;
563 struct timeval tv = {t / 1000, (t % 1000) * 1000};
564 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
565 &tv, sizeof(tv));
566
567 // Receive cycle
568 len = recvmsg(sock, &msg, 0);
569 if (len < 0)
570 continue;
571
572 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
573 ch = CMSG_NXTHDR(&msg, ch)) {
574 if (ch->cmsg_level == SOL_IPV6 &&
575 ch->cmsg_type == IPV6_PKTINFO) {
576 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
577 break;
578 }
579 }
580
581 if (pktinfo == NULL) {
582 len = -1;
583 continue;
584 }
585
586 if (!dhcpv6_response_is_valid(buf, len, trid,
587 type, &pktinfo->ipi6_addr)) {
588 len = -1;
589 continue;
590 }
591
592 uint8_t *opt = &buf[4];
593 uint8_t *opt_end = opt + len - 4;
594
595 round_start = odhcp6c_get_milli_time();
596 elapsed = round_start - start;
597 syslog(LOG_NOTICE, "Got a valid reply after "
598 "%llums", (unsigned long long)elapsed);
599
600 if (retx->handler_reply)
601 len = retx->handler_reply(type, rc, opt, opt_end);
602
603 if (len > 0 && round_end - round_start > 1000)
604 round_end = 1000 + round_start;
605 }
606
607 // Allow
608 if (retx->handler_finish)
609 len = retx->handler_finish();
610 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
611 (!retx->max_rc || rc < retx->max_rc));
612 return len;
613 }
614
615 // Message validation checks according to RFC3315 chapter 15
616 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
617 const uint8_t transaction[3], enum dhcpv6_msg type,
618 const struct in6_addr *daddr)
619 {
620 const struct dhcpv6_header *rep = buf;
621 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
622 transaction, sizeof(rep->tr_id)))
623 return false; // Invalid reply
624
625 if (type == DHCPV6_MSG_SOLICIT) {
626 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
627 rep->msg_type != DHCPV6_MSG_REPLY)
628 return false;
629 } else if (type == DHCPV6_MSG_UNKNOWN) {
630 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
631 return false;
632 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
633 return false;
634 }
635
636 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
637 rcmsg = DHCPV6_MSG_UNKNOWN;
638 uint16_t otype, olen = UINT16_MAX;
639 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
640 ia_present = false, options_valid = true;
641
642 size_t client_id_len, server_id_len;
643 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
644 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
645
646 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
647 if (otype == DHCPV6_OPT_CLIENTID) {
648 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
649 &odata[-4], client_id, client_id_len);
650 } else if (otype == DHCPV6_OPT_SERVERID) {
651 if (server_id_len)
652 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
653 &odata[-4], server_id, server_id_len);
654 else
655 serverid_ok = true;
656 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
657 sizeof(struct dhcpv6_auth_reconfigure)) {
658 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
659 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
660 continue;
661
662 md5_ctx_t md5;
663 uint8_t serverhash[16], secretbytes[64], hash[16];
664 memcpy(serverhash, r->key, sizeof(serverhash));
665 memset(r->key, 0, sizeof(r->key));
666
667 memset(secretbytes, 0, sizeof(secretbytes));
668 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
669
670 for (size_t i = 0; i < sizeof(secretbytes); ++i)
671 secretbytes[i] ^= 0x36;
672
673 md5_begin(&md5);
674 md5_hash(secretbytes, sizeof(secretbytes), &md5);
675 md5_hash(buf, len, &md5);
676 md5_end(hash, &md5);
677
678 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
679 secretbytes[i] ^= 0x36;
680 secretbytes[i] ^= 0x5c;
681 }
682
683 md5_begin(&md5);
684 md5_hash(secretbytes, sizeof(secretbytes), &md5);
685 md5_hash(hash, 16, &md5);
686 md5_end(hash, &md5);
687
688 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
689 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
690 rcmsg = odata[0];
691 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
692 ia_present = true;
693 if (olen < sizeof(struct dhcpv6_ia_hdr))
694 options_valid = false;
695 }
696 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
697 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
698 // Options are not allowed on global level
699 options_valid = false;
700 }
701 }
702
703 if (!options_valid || ((odata + olen) > end))
704 return false;
705
706 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
707 return false;
708
709 if (rep->msg_type == DHCPV6_MSG_RECONF) {
710 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
711 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
712 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
713 return false;
714 }
715
716 return clientid_ok && serverid_ok;
717 }
718
719
720 int dhcpv6_poll_reconfigure(void)
721 {
722 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
723 if (ret != -1)
724 ret = dhcpv6_request(ret);
725
726 return ret;
727 }
728
729
730 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
731 const void *opt, const void *end)
732 {
733 uint16_t otype, olen;
734 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
735 dhcpv6_for_each_option(opt, end, otype, olen, odata)
736 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
737 odata[0] == DHCPV6_MSG_RENEW ||
738 odata[0] == DHCPV6_MSG_INFO_REQ))
739 msg = odata[0];
740
741 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
742 return msg;
743 }
744
745
746 // Collect all advertised servers
747 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
748 const void *opt, const void *end)
749 {
750 uint16_t olen, otype;
751 uint8_t *odata, pref = 0;
752 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
753 DHCPV6_SOL_MAX_RT,
754 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
755 bool have_na = false;
756 int have_pd = 0;
757
758 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
759 if (orig == DHCPV6_MSG_SOLICIT &&
760 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
761 olen > sizeof(struct dhcpv6_ia_hdr)) {
762 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
763 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
764 }
765
766 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
767 memcpy(cand.duid, odata, olen);
768 cand.duid_len = olen;
769 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
770 int error = ((int)odata[0] << 8 | (int)odata[1]);
771
772 switch (error) {
773 case DHCPV6_NoPrefixAvail:
774 // Status code on global level
775 cand.preference -= 2000;
776 break;
777
778 default :
779 break;
780 }
781 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
782 cand.preference >= 0) {
783 cand.preference = pref = odata[0];
784 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
785 cand.wants_reconfigure = true;
786 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
787 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
788 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
789 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
790 cand.sol_max_rt = sol_max_rt;
791 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
792 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
793 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
794 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
795 cand.inf_max_rt = inf_max_rt;
796 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
797 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
798 uint8_t *oend = odata + olen, *d;
799 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
800 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
801 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
802 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
803 have_pd = p->prefix;
804 }
805 }
806 } else if (otype == DHCPV6_OPT_IA_NA) {
807 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
808 uint8_t *oend = odata + olen, *d;
809 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
810 if (otype == DHCPV6_OPT_IA_ADDR)
811 have_na = true;
812 }
813 }
814
815 if ((!have_na && na_mode == IA_MODE_FORCE) ||
816 (!have_pd && pd_mode == IA_MODE_FORCE)) {
817 /*
818 * RFC7083 states to process the SOL_MAX_RT and
819 * INF_MAX_RT options even if the DHCPv6 server
820 * did not propose any IA_NA and/or IA_PD
821 */
822 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
823 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
824 return -1;
825 }
826
827 if (na_mode != IA_MODE_NONE && !have_na) {
828 cand.has_noaddravail = true;
829 cand.preference -= 1000;
830 }
831
832 if (pd_mode != IA_MODE_NONE) {
833 if (have_pd)
834 cand.preference += 2000 + (128 - have_pd);
835 else
836 cand.preference -= 2000;
837 }
838
839 if (cand.duid_len > 0) {
840 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
841 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
842 dhcpv6_add_server_cand(&cand);
843 }
844
845 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
846 }
847
848
849 static int dhcpv6_commit_advert(void)
850 {
851 return dhcpv6_promote_server_cand();
852 }
853
854
855 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
856 const void *opt, const void *end)
857 {
858 dhcpv6_handle_advert(orig, rc, opt, end);
859 if (dhcpv6_commit_advert() < 0)
860 return -1;
861
862 return dhcpv6_handle_reply(orig, rc, opt, end);
863 }
864
865
866 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
867 const void *opt, const void *end)
868 {
869 uint8_t *odata;
870 uint16_t otype, olen;
871 uint32_t refresh = UINT32_MAX;
872 int ret = 1;
873 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
874
875 odhcp6c_expire();
876
877 if (orig == DHCPV6_MSG_UNKNOWN) {
878 static time_t last_update = 0;
879 time_t now = odhcp6c_get_milli_time() / 1000;
880
881 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
882 last_update = now;
883
884 if (t1 != UINT32_MAX)
885 t1 -= elapsed;
886
887 if (t2 != UINT32_MAX)
888 t2 -= elapsed;
889
890 if (t3 != UINT32_MAX)
891 t3 -= elapsed;
892
893 if (t1 < 0)
894 t1 = 0;
895
896 if (t2 < 0)
897 t2 = 0;
898
899 if (t3 < 0)
900 t3 = 0;
901 }
902
903 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
904 // Delete NA and PD we have in the state from the Advert
905 odhcp6c_clear_state(STATE_IA_NA);
906 odhcp6c_clear_state(STATE_IA_PD);
907 }
908
909 if (opt) {
910 odhcp6c_clear_state(STATE_DNS);
911 odhcp6c_clear_state(STATE_SEARCH);
912 odhcp6c_clear_state(STATE_SNTP_IP);
913 odhcp6c_clear_state(STATE_NTP_IP);
914 odhcp6c_clear_state(STATE_NTP_FQDN);
915 odhcp6c_clear_state(STATE_SIP_IP);
916 odhcp6c_clear_state(STATE_SIP_FQDN);
917 odhcp6c_clear_state(STATE_AFTR_NAME);
918 }
919
920 // Parse and find all matching IAs
921 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
922 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
923 && olen > sizeof(struct dhcpv6_ia_hdr)) {
924 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
925
926 // Test ID
927 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
928 continue;
929
930 uint16_t code = DHCPV6_Success;
931 uint16_t stype, slen;
932 uint8_t *sdata;
933 // Get and handle status code
934 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
935 stype, slen, sdata) {
936 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
937 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
938 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
939
940 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
941
942 if (code == DHCPV6_Success)
943 continue;
944
945 dhcpv6_handle_ia_status_code(orig, ia_hdr,
946 code, mdata, mlen, handled_status_codes, &ret);
947
948
949 if (ret > 0)
950 return ret;
951 break;
952 }
953 }
954
955 if (code != DHCPV6_Success)
956 continue;
957
958 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
959 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
960 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
961 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
962 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
963
964 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
965 }
966 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
967 if (olen % 16 == 0)
968 odhcp6c_add_state(STATE_DNS, odata, olen);
969 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
970 odhcp6c_add_state(STATE_SEARCH, odata, olen);
971 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
972 if (olen % 16 == 0)
973 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
974 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
975 uint16_t stype, slen;
976 uint8_t *sdata;
977 // Test status and bail if error
978 dhcpv6_for_each_option(odata, odata + olen,
979 stype, slen, sdata) {
980 if (slen == 16 && (stype == NTP_MC_ADDR ||
981 stype == NTP_SRV_ADDR))
982 odhcp6c_add_state(STATE_NTP_IP,
983 sdata, slen);
984 else if (slen > 0 && stype == NTP_SRV_FQDN)
985 odhcp6c_add_state(STATE_NTP_FQDN,
986 sdata, slen);
987 }
988 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
989 if (olen == 16)
990 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
991 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
992 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
993 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
994 refresh = ntohl(*((uint32_t*)odata));
995 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
996 sizeof(struct dhcpv6_auth_reconfigure)) {
997 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
998 if (r->protocol == 3 && r->algorithm == 1 &&
999 r->reconf_type == 1)
1000 memcpy(reconf_key, r->key, sizeof(r->key));
1001 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1002 size_t cur_len;
1003 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1004 if (cur_len == 0)
1005 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1006 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1007 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
1008 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1009 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1010 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1011 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1012 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
1013 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1014 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1015 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1016 #ifdef EXT_CER_ID
1017 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1018 sizeof(struct dhcpv6_cer_id)) {
1019 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1020 struct in6_addr any = IN6ADDR_ANY_INIT;
1021 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1022 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1023 #endif
1024 } else if (otype != DHCPV6_OPT_CLIENTID &&
1025 otype != DHCPV6_OPT_SERVERID) {
1026 odhcp6c_add_state(STATE_CUSTOM_OPTS,
1027 &odata[-4], olen + 4);
1028 }
1029 }
1030
1031 if (orig != DHCPV6_MSG_INFO_REQ) {
1032 // Update refresh timers if no fatal status code was received
1033 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1034 switch (orig) {
1035 case DHCPV6_MSG_RENEW:
1036 // Send further renews if T1 is not set
1037 if (!t1)
1038 ret = -1;
1039 break;
1040 case DHCPV6_MSG_REBIND:
1041 // Send further rebinds if T1 and T2 is not set
1042 if (!t1 && !t2)
1043 ret = -1;
1044 break;
1045
1046 case DHCPV6_MSG_REQUEST:
1047 // All server candidates can be cleared if not yet bound
1048 if (!odhcp6c_is_bound())
1049 dhcpv6_clear_all_server_cand();
1050
1051 default :
1052 break;
1053 }
1054 }
1055 }
1056 else if (ret > 0) {
1057 // All server candidates can be cleared if not yet bound
1058 if (!odhcp6c_is_bound())
1059 dhcpv6_clear_all_server_cand();
1060
1061 t1 = refresh;
1062 }
1063
1064 return ret;
1065 }
1066
1067
1068 static int dhcpv6_parse_ia(void *opt, void *end)
1069 {
1070 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1071 int parsed_ia = 0;
1072 uint32_t t1, t2;
1073 uint16_t otype, olen;
1074 uint8_t *odata;
1075
1076 t1 = ntohl(ia_hdr->t1);
1077 t2 = ntohl(ia_hdr->t2);
1078
1079 if (t1 > t2)
1080 return 0;
1081
1082 // Update address IA
1083 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1084 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1085 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1086
1087 entry.iaid = ia_hdr->iaid;
1088
1089 if (otype == DHCPV6_OPT_IA_PREFIX) {
1090 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1091 if (olen + 4U < sizeof(*prefix))
1092 continue;
1093
1094 entry.valid = ntohl(prefix->valid);
1095 entry.preferred = ntohl(prefix->preferred);
1096
1097 if (entry.preferred > entry.valid)
1098 continue;
1099
1100 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1101 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1102 if (entry.t1 > entry.t2)
1103 entry.t1 = entry.t2;
1104
1105 entry.length = prefix->prefix;
1106 entry.target = prefix->addr;
1107 uint16_t stype, slen;
1108 uint8_t *sdata;
1109
1110 #ifdef EXT_PREFIX_CLASS
1111 // Find prefix class, if any
1112 dhcpv6_for_each_option(&prefix[1], odata + olen,
1113 stype, slen, sdata)
1114 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1115 entry.class = sdata[0] << 8 | sdata[1];
1116 #endif
1117
1118 // Parse PD-exclude
1119 bool ok = true;
1120 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1121 odata + olen, stype, slen, sdata) {
1122 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1123 continue;
1124
1125 uint8_t elen = sdata[0];
1126 if (elen > 64)
1127 elen = 64;
1128
1129 if (elen <= 32 || elen <= entry.length) {
1130 ok = false;
1131 continue;
1132 }
1133
1134
1135 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1136 if (slen <= bytes) {
1137 ok = false;
1138 continue;
1139 }
1140
1141 uint32_t exclude = 0;
1142 do {
1143 exclude = exclude << 8 | sdata[bytes];
1144 } while (--bytes);
1145
1146 exclude >>= 8 - ((elen - entry.length) % 8);
1147 exclude <<= 64 - elen;
1148
1149 // Abusing router & priority fields for exclusion
1150 entry.router = entry.target;
1151 entry.router.s6_addr32[1] |= htonl(exclude);
1152 entry.priority = elen;
1153 }
1154
1155 if (ok) {
1156 odhcp6c_update_entry(STATE_IA_PD, &entry);
1157 parsed_ia++;
1158 }
1159
1160 entry.priority = 0;
1161 memset(&entry.router, 0, sizeof(entry.router));
1162 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1163 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1164 if (olen + 4U < sizeof(*addr))
1165 continue;
1166
1167 entry.preferred = ntohl(addr->preferred);
1168 entry.valid = ntohl(addr->valid);
1169
1170 if (entry.preferred > entry.valid)
1171 continue;
1172
1173 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1174 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1175 if (entry.t1 > entry.t2)
1176 entry.t1 = entry.t2;
1177
1178 entry.length = 128;
1179 entry.target = addr->addr;
1180
1181 #ifdef EXT_PREFIX_CLASS
1182 uint16_t stype, slen;
1183 uint8_t *sdata;
1184 // Find prefix class, if any
1185 dhcpv6_for_each_option(&addr[1], odata + olen,
1186 stype, slen, sdata)
1187 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1188 entry.class = sdata[0] << 8 | sdata[1];
1189 #endif
1190
1191 odhcp6c_update_entry(STATE_IA_NA, &entry);
1192 parsed_ia++;
1193 }
1194 }
1195 return parsed_ia;
1196 }
1197
1198
1199 static int dhcpv6_calc_refresh_timers(void)
1200 {
1201 struct odhcp6c_entry *e;
1202 size_t ia_na_entries, ia_pd_entries, i;
1203 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1204
1205 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1206 ia_na_entries /= sizeof(*e);
1207 for (i = 0; i < ia_na_entries; i++) {
1208 if (e[i].t1 < l_t1)
1209 l_t1 = e[i].t1;
1210
1211 if (e[i].t2 < l_t2)
1212 l_t2 = e[i].t2;
1213
1214 if (e[i].valid > l_t3)
1215 l_t3 = e[i].valid;
1216 }
1217
1218 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1219 ia_pd_entries /= sizeof(*e);
1220 for (i = 0; i < ia_pd_entries; i++) {
1221 if (e[i].t1 < l_t1)
1222 l_t1 = e[i].t1;
1223
1224 if (e[i].t2 < l_t2)
1225 l_t2 = e[i].t2;
1226
1227 if (e[i].valid > l_t3)
1228 l_t3 = e[i].valid;
1229 }
1230
1231 if (ia_pd_entries || ia_na_entries) {
1232 t1 = l_t1;
1233 t2 = l_t2;
1234 t3 = l_t3;
1235 } else {
1236 t1 = 600;
1237 }
1238
1239 return (int)(ia_pd_entries + ia_na_entries);
1240 }
1241
1242
1243 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1244 const void *status_msg, const int len)
1245 {
1246 uint8_t buf[len + 3];
1247
1248 memset(buf, 0, sizeof(buf));
1249 if (len) {
1250 buf[0] = '(';
1251 memcpy(&buf[1], status_msg, len);
1252 buf[len + 1] = ')';
1253 }
1254
1255 syslog(LOG_WARNING, "Server returned %s status %i %s",
1256 scope, code, buf);
1257 }
1258
1259
1260 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1261 const uint16_t code, const void *status_msg, const int len,
1262 int *ret)
1263 {
1264 dhcpv6_log_status_code(code, "message", status_msg, len);
1265
1266 switch (code) {
1267 case DHCPV6_UnspecFail:
1268 // Generic failure
1269 *ret = 0;
1270 break;
1271
1272 case DHCPV6_UseMulticast:
1273 // TODO handle multicast status code
1274 break;
1275
1276 case DHCPV6_NoAddrsAvail:
1277 case DHCPV6_NoPrefixAvail:
1278 if (orig == DHCPV6_MSG_REQUEST)
1279 *ret = 0; // Failure
1280 break;
1281
1282 default:
1283 break;
1284 }
1285 }
1286
1287
1288 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1289 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1290 const void *status_msg, const int len,
1291 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1292 {
1293 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1294 "IA_NA" : "IA_PD", status_msg, len);
1295
1296 switch (code) {
1297 case DHCPV6_NoBinding:
1298 switch (orig) {
1299 case DHCPV6_MSG_RENEW:
1300 case DHCPV6_MSG_REBIND:
1301 if ((*ret > 0) && !handled_status_codes[code])
1302 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1303 break;
1304
1305 default:
1306 break;
1307 }
1308 break;
1309
1310 case DHCPV6_NoAddrsAvail:
1311 case DHCPV6_NoPrefixAvail:
1312 switch (orig) {
1313 case DHCPV6_MSG_REQUEST:
1314 if (*ret != 0)
1315 *ret = 0;
1316 break;
1317 default:
1318 break;
1319 }
1320 break;
1321
1322 case DHCPV6_NotOnLink:
1323 // TODO handle not onlink in case of confirm
1324 break;
1325
1326 default:
1327 break;
1328 }
1329 }
1330
1331 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1332 {
1333 size_t cand_len, i;
1334 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1335
1336 // Remove identical duid server candidate
1337 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1338 if (cand->duid_len == c[i].duid_len &&
1339 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1340 free(c[i].ia_na);
1341 free(c[i].ia_pd);
1342 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1343 break;
1344 }
1345 }
1346
1347 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1348 i < cand_len / sizeof(*c); ++i) {
1349 if (c[i].preference < cand->preference)
1350 break;
1351 }
1352
1353 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1354 }
1355
1356 static void dhcpv6_clear_all_server_cand(void)
1357 {
1358 size_t cand_len, i;
1359 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1360
1361 // Server candidates need deep delete for IA_NA/IA_PD
1362 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1363 free(c[i].ia_na);
1364 free(c[i].ia_pd);
1365 }
1366 odhcp6c_clear_state(STATE_SERVER_CAND);
1367 }
1368
1369 int dhcpv6_promote_server_cand(void)
1370 {
1371 size_t cand_len;
1372 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1373 uint16_t hdr[2];
1374 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1375 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1376
1377 // Clear lingering candidate state info
1378 odhcp6c_clear_state(STATE_SERVER_ID);
1379 odhcp6c_clear_state(STATE_IA_NA);
1380 odhcp6c_clear_state(STATE_IA_PD);
1381
1382 if (!cand_len)
1383 return -1;
1384
1385 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1386 na_mode = IA_MODE_NONE;
1387
1388 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1389 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1390
1391 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1392 }
1393
1394 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1395 hdr[1] = htons(cand->duid_len);
1396 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1397 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1398 accept_reconfig = cand->wants_reconfigure;
1399 if (cand->ia_na_len) {
1400 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1401 free(cand->ia_na);
1402 if (na_mode != IA_MODE_NONE)
1403 ret = DHCPV6_STATEFUL;
1404 }
1405 if (cand->ia_pd_len) {
1406 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1407 free(cand->ia_pd);
1408 if (request_prefix)
1409 ret = DHCPV6_STATEFUL;
1410 }
1411
1412 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1413 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1414
1415 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1416
1417 return ret;
1418 }
Openwrt DHCPv6 Client