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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 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 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
332 ia_pd_len += sizeof(p);
333
334 if (ex_len) {
335 ia_pd[ia_pd_len++] = 0;
336 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
337 ia_pd[ia_pd_len++] = 0;
338 ia_pd[ia_pd_len++] = ex_len - 4;
339 ia_pd[ia_pd_len++] = e[j].priority;
340
341 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
342 excl >>= (64 - e[j].priority);
343 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
344
345 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
346 ia_pd[ia_pd_len + i] = excl & 0xff;
347 ia_pd_len += ex_len - 5;
348 }
349
350 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
351 }
352 }
353 }
354
355 if (ia_pd_entries > 0)
356 request_prefix = 1;
357
358 // Build IA_NAs
359 size_t ia_na_entries, ia_na_len = 0;
360 void *ia_na = NULL;
361 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
362 ia_na_entries /= sizeof(*e);
363
364 struct dhcpv6_ia_hdr hdr_ia_na = {
365 htons(DHCPV6_OPT_IA_NA),
366 htons(sizeof(hdr_ia_na) - 4),
367 htonl(1), 0, 0
368 };
369
370 struct dhcpv6_ia_addr pa[ia_na_entries];
371 for (size_t i = 0; i < ia_na_entries; ++i) {
372 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
373 pa[i].len = htons(sizeof(pa[i]) - 4U);
374 pa[i].addr = e[i].target;
375 pa[i].preferred = 0;
376 pa[i].valid = 0;
377 }
378
379 ia_na = pa;
380 ia_na_len = sizeof(pa);
381 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
382
383 // Reconfigure Accept
384 struct {
385 uint16_t type;
386 uint16_t length;
387 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
388
389 // Request Information Refresh
390 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
391
392 // Build vendor-class option
393 size_t vendor_class_len, user_class_len;
394 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
395 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
396
397 struct {
398 uint16_t type;
399 uint16_t length;
400 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
401
402 struct {
403 uint16_t type;
404 uint16_t length;
405 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
406
407 // Prepare Header
408 size_t oro_len;
409 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
410 struct {
411 uint8_t type;
412 uint8_t trid[3];
413 uint16_t elapsed_type;
414 uint16_t elapsed_len;
415 uint16_t elapsed_value;
416 uint16_t oro_type;
417 uint16_t oro_len;
418 } hdr = {
419 type, {trid[0], trid[1], trid[2]},
420 htons(DHCPV6_OPT_ELAPSED), htons(2),
421 htons((ecs > 0xffff) ? 0xffff : ecs),
422 htons(DHCPV6_OPT_ORO), htons(oro_len),
423 };
424
425 struct iovec iov[IOV_TOTAL] = {
426 [IOV_HDR] = {&hdr, sizeof(hdr)},
427 [IOV_ORO] = {oro, oro_len},
428 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
429 [IOV_CL_ID] = {cl_id, cl_id_len},
430 [IOV_SRV_ID] = {srv_id, srv_id_len},
431 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
432 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
433 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
434 [IOV_USER_CLASS] = {user_class, user_class_len},
435 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
436 [IOV_FQDN] = {&fqdn, fqdn_len},
437 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
438 [IOV_IA_NA] = {ia_na, ia_na_len},
439 [IOV_IA_PD] = {ia_pd, ia_pd_len},
440 };
441
442 size_t cnt = IOV_TOTAL;
443 if (type == DHCPV6_MSG_INFO_REQ) {
444 cnt = 9;
445 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
446 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
447 } else if (!request_prefix) {
448 cnt = 13;
449 }
450
451 // Disable IAs if not used
452 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
453 iov[IOV_HDR_IA_NA].iov_len = 0;
454
455 if (na_mode == IA_MODE_NONE)
456 iov[IOV_HDR_IA_NA].iov_len = 0;
457
458 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
459 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
460 iov[IOV_RECONF_ACCEPT].iov_len = 0;
461
462 if (!(client_options & DHCPV6_CLIENT_FQDN))
463 iov[IOV_FQDN].iov_len = 0;
464
465 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
466 0, ALL_DHCPV6_RELAYS, ifindex};
467 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
468
469 sendmsg(sock, &msg, 0);
470 }
471
472
473 static int64_t dhcpv6_rand_delay(int64_t time)
474 {
475 int random;
476 odhcp6c_random(&random, sizeof(random));
477 return (time * ((int64_t)random % 1000LL)) / 10000LL;
478 }
479
480
481 int dhcpv6_request(enum dhcpv6_msg type)
482 {
483 uint8_t rc = 0;
484 uint64_t timeout = UINT32_MAX;
485 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
486
487 if (retx->delay) {
488 struct timespec ts = {0, 0};
489 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
490 nanosleep(&ts, NULL);
491 }
492
493 if (type == DHCPV6_MSG_UNKNOWN)
494 timeout = t1;
495 else if (type == DHCPV6_MSG_RENEW)
496 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
497 else if (type == DHCPV6_MSG_REBIND)
498 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
499
500 if (timeout == 0)
501 return -1;
502
503 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
504 retx->name, (unsigned long long)timeout, retx->max_rc);
505
506 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
507
508 // Generate transaction ID
509 uint8_t trid[3] = {0, 0, 0};
510 if (type != DHCPV6_MSG_UNKNOWN)
511 odhcp6c_random(trid, sizeof(trid));
512 ssize_t len = -1;
513 int64_t rto = 0;
514
515 do {
516 if (rto == 0) {
517 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
518
519 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
520 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
521 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
522
523 rto = (retx->init_timeo * 1000 + delay);
524 }
525 else
526 rto = (2 * rto + dhcpv6_rand_delay(rto));
527
528 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
529 rto = retx->max_timeo * 1000 +
530 dhcpv6_rand_delay(retx->max_timeo * 1000);
531
532 // Calculate end for this round and elapsed time
533 uint64_t round_end = round_start + rto;
534 elapsed = round_start - start;
535
536 // Don't wait too long if timeout differs from infinite
537 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
538 round_end = timeout * 1000 + start;
539
540 // Built and send package
541 if (type != DHCPV6_MSG_UNKNOWN) {
542 if (type != DHCPV6_MSG_SOLICIT)
543 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
544 retx->name, (unsigned long long)elapsed, rc);
545 dhcpv6_send(type, trid, elapsed / 10);
546 rc++;
547 }
548
549 // Receive rounds
550 for (; len < 0 && (round_start < round_end);
551 round_start = odhcp6c_get_milli_time()) {
552 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
553 struct iovec iov = {buf, sizeof(buf)};
554 struct msghdr msg = {NULL, 0, &iov, 1,
555 cmsg_buf, sizeof(cmsg_buf), 0};
556 struct in6_pktinfo *pktinfo = NULL;
557
558 // Check for pending signal
559 if (odhcp6c_signal_process())
560 return -1;
561
562 // Set timeout for receiving
563 uint64_t t = round_end - round_start;
564 struct timeval tv = {t / 1000, (t % 1000) * 1000};
565 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
566 &tv, sizeof(tv));
567
568 // Receive cycle
569 len = recvmsg(sock, &msg, 0);
570 if (len < 0)
571 continue;
572
573 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
574 ch = CMSG_NXTHDR(&msg, ch)) {
575 if (ch->cmsg_level == SOL_IPV6 &&
576 ch->cmsg_type == IPV6_PKTINFO) {
577 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
578 break;
579 }
580 }
581
582 if (pktinfo == NULL) {
583 len = -1;
584 continue;
585 }
586
587 if (!dhcpv6_response_is_valid(buf, len, trid,
588 type, &pktinfo->ipi6_addr)) {
589 len = -1;
590 continue;
591 }
592
593 uint8_t *opt = &buf[4];
594 uint8_t *opt_end = opt + len - 4;
595
596 round_start = odhcp6c_get_milli_time();
597 elapsed = round_start - start;
598 syslog(LOG_NOTICE, "Got a valid reply after "
599 "%llums", (unsigned long long)elapsed);
600
601 if (retx->handler_reply)
602 len = retx->handler_reply(type, rc, opt, opt_end);
603
604 if (len > 0 && round_end - round_start > 1000)
605 round_end = 1000 + round_start;
606 }
607
608 // Allow
609 if (retx->handler_finish)
610 len = retx->handler_finish();
611 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
612 (!retx->max_rc || rc < retx->max_rc));
613 return len;
614 }
615
616 // Message validation checks according to RFC3315 chapter 15
617 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
618 const uint8_t transaction[3], enum dhcpv6_msg type,
619 const struct in6_addr *daddr)
620 {
621 const struct dhcpv6_header *rep = buf;
622 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
623 transaction, sizeof(rep->tr_id)))
624 return false; // Invalid reply
625
626 if (type == DHCPV6_MSG_SOLICIT) {
627 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
628 rep->msg_type != DHCPV6_MSG_REPLY)
629 return false;
630 } else if (type == DHCPV6_MSG_UNKNOWN) {
631 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
632 return false;
633 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
634 return false;
635 }
636
637 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
638 rcmsg = DHCPV6_MSG_UNKNOWN;
639 uint16_t otype, olen = UINT16_MAX;
640 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
641 ia_present = false, options_valid = true;
642
643 size_t client_id_len, server_id_len;
644 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
645 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
646
647 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
648 if (otype == DHCPV6_OPT_CLIENTID) {
649 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
650 &odata[-4], client_id, client_id_len);
651 } else if (otype == DHCPV6_OPT_SERVERID) {
652 if (server_id_len)
653 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
654 &odata[-4], server_id, server_id_len);
655 else
656 serverid_ok = true;
657 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
658 sizeof(struct dhcpv6_auth_reconfigure)) {
659 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
660 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
661 continue;
662
663 md5_ctx_t md5;
664 uint8_t serverhash[16], secretbytes[64], hash[16];
665 memcpy(serverhash, r->key, sizeof(serverhash));
666 memset(r->key, 0, sizeof(r->key));
667
668 memset(secretbytes, 0, sizeof(secretbytes));
669 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
670
671 for (size_t i = 0; i < sizeof(secretbytes); ++i)
672 secretbytes[i] ^= 0x36;
673
674 md5_begin(&md5);
675 md5_hash(secretbytes, sizeof(secretbytes), &md5);
676 md5_hash(buf, len, &md5);
677 md5_end(hash, &md5);
678
679 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
680 secretbytes[i] ^= 0x36;
681 secretbytes[i] ^= 0x5c;
682 }
683
684 md5_begin(&md5);
685 md5_hash(secretbytes, sizeof(secretbytes), &md5);
686 md5_hash(hash, 16, &md5);
687 md5_end(hash, &md5);
688
689 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
690 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
691 rcmsg = odata[0];
692 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
693 ia_present = true;
694 if (olen < sizeof(struct dhcpv6_ia_hdr))
695 options_valid = false;
696 }
697 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
698 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
699 // Options are not allowed on global level
700 options_valid = false;
701 }
702 }
703
704 if (!options_valid || ((odata + olen) > end))
705 return false;
706
707 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
708 return false;
709
710 if (rep->msg_type == DHCPV6_MSG_RECONF) {
711 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
712 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
713 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
714 return false;
715 }
716
717 return clientid_ok && serverid_ok;
718 }
719
720
721 int dhcpv6_poll_reconfigure(void)
722 {
723 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
724 if (ret != -1)
725 ret = dhcpv6_request(ret);
726
727 return ret;
728 }
729
730
731 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
732 const void *opt, const void *end)
733 {
734 uint16_t otype, olen;
735 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
736 dhcpv6_for_each_option(opt, end, otype, olen, odata)
737 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
738 odata[0] == DHCPV6_MSG_RENEW ||
739 odata[0] == DHCPV6_MSG_INFO_REQ))
740 msg = odata[0];
741
742 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
743 return msg;
744 }
745
746
747 // Collect all advertised servers
748 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
749 const void *opt, const void *end)
750 {
751 uint16_t olen, otype;
752 uint8_t *odata, pref = 0;
753 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
754 DHCPV6_SOL_MAX_RT,
755 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
756 bool have_na = false;
757 int have_pd = 0;
758
759 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
760 if (orig == DHCPV6_MSG_SOLICIT &&
761 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
762 olen > sizeof(struct dhcpv6_ia_hdr)) {
763 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
764 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
765 }
766
767 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
768 memcpy(cand.duid, odata, olen);
769 cand.duid_len = olen;
770 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
771 int error = ((int)odata[0] << 8 | (int)odata[1]);
772
773 switch (error) {
774 case DHCPV6_NoPrefixAvail:
775 // Status code on global level
776 cand.preference -= 2000;
777 break;
778
779 default :
780 break;
781 }
782 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
783 cand.preference >= 0) {
784 cand.preference = pref = odata[0];
785 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
786 cand.wants_reconfigure = true;
787 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
788 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
789 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
790 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
791 cand.sol_max_rt = sol_max_rt;
792 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
793 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
794 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
795 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
796 cand.inf_max_rt = inf_max_rt;
797 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
798 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
799 uint8_t *oend = odata + olen, *d;
800 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
801 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
802 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
803 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
804 have_pd = p->prefix;
805 }
806 }
807 } else if (otype == DHCPV6_OPT_IA_NA) {
808 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
809 uint8_t *oend = odata + olen, *d;
810 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
811 if (otype == DHCPV6_OPT_IA_ADDR)
812 have_na = true;
813 }
814 }
815
816 if ((!have_na && na_mode == IA_MODE_FORCE) ||
817 (!have_pd && pd_mode == IA_MODE_FORCE)) {
818 /*
819 * RFC7083 states to process the SOL_MAX_RT and
820 * INF_MAX_RT options even if the DHCPv6 server
821 * did not propose any IA_NA and/or IA_PD
822 */
823 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
824 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
825 return -1;
826 }
827
828 if (na_mode != IA_MODE_NONE && !have_na) {
829 cand.has_noaddravail = true;
830 cand.preference -= 1000;
831 }
832
833 if (pd_mode != IA_MODE_NONE) {
834 if (have_pd)
835 cand.preference += 2000 + (128 - have_pd);
836 else
837 cand.preference -= 2000;
838 }
839
840 if (cand.duid_len > 0) {
841 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
842 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
843 dhcpv6_add_server_cand(&cand);
844 }
845
846 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
847 }
848
849
850 static int dhcpv6_commit_advert(void)
851 {
852 return dhcpv6_promote_server_cand();
853 }
854
855
856 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
857 const void *opt, const void *end)
858 {
859 dhcpv6_handle_advert(orig, rc, opt, end);
860 if (dhcpv6_commit_advert() < 0)
861 return -1;
862
863 return dhcpv6_handle_reply(orig, rc, opt, end);
864 }
865
866
867 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
868 const void *opt, const void *end)
869 {
870 uint8_t *odata;
871 uint16_t otype, olen;
872 uint32_t refresh = UINT32_MAX;
873 int ret = 1;
874 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
875
876 odhcp6c_expire();
877
878 if (orig == DHCPV6_MSG_UNKNOWN) {
879 static time_t last_update = 0;
880 time_t now = odhcp6c_get_milli_time() / 1000;
881
882 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
883 last_update = now;
884
885 if (t1 != UINT32_MAX)
886 t1 -= elapsed;
887
888 if (t2 != UINT32_MAX)
889 t2 -= elapsed;
890
891 if (t3 != UINT32_MAX)
892 t3 -= elapsed;
893
894 if (t1 < 0)
895 t1 = 0;
896
897 if (t2 < 0)
898 t2 = 0;
899
900 if (t3 < 0)
901 t3 = 0;
902 }
903
904 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
905 // Delete NA and PD we have in the state from the Advert
906 odhcp6c_clear_state(STATE_IA_NA);
907 odhcp6c_clear_state(STATE_IA_PD);
908 }
909
910 if (opt) {
911 odhcp6c_clear_state(STATE_DNS);
912 odhcp6c_clear_state(STATE_SEARCH);
913 odhcp6c_clear_state(STATE_SNTP_IP);
914 odhcp6c_clear_state(STATE_NTP_IP);
915 odhcp6c_clear_state(STATE_NTP_FQDN);
916 odhcp6c_clear_state(STATE_SIP_IP);
917 odhcp6c_clear_state(STATE_SIP_FQDN);
918 odhcp6c_clear_state(STATE_AFTR_NAME);
919 odhcp6c_clear_state(STATE_CER);
920 odhcp6c_clear_state(STATE_S46_MAPT);
921 odhcp6c_clear_state(STATE_S46_MAPE);
922 odhcp6c_clear_state(STATE_S46_LW);
923 odhcp6c_clear_state(STATE_PASSTHRU);
924 }
925
926 // Parse and find all matching IAs
927 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
928 bool passthru = true;
929
930 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
931 && olen > sizeof(struct dhcpv6_ia_hdr)) {
932 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
933
934 // Test ID
935 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
936 continue;
937
938 uint16_t code = DHCPV6_Success;
939 uint16_t stype, slen;
940 uint8_t *sdata;
941 // Get and handle status code
942 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
943 stype, slen, sdata) {
944 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
945 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
946 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
947
948 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
949
950 if (code == DHCPV6_Success)
951 continue;
952
953 dhcpv6_handle_ia_status_code(orig, ia_hdr,
954 code, mdata, mlen, handled_status_codes, &ret);
955
956
957 if (ret > 0)
958 return ret;
959 break;
960 }
961 }
962
963 if (code != DHCPV6_Success)
964 continue;
965
966 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
967 passthru = false;
968 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
969 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
970 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
971 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
972
973 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
974 passthru = false;
975 }
976 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
977 if (olen % 16 == 0)
978 odhcp6c_add_state(STATE_DNS, odata, olen);
979 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
980 odhcp6c_add_state(STATE_SEARCH, odata, olen);
981 passthru = false;
982 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
983 if (olen % 16 == 0)
984 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
985 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
986 uint16_t stype, slen;
987 uint8_t *sdata;
988 // Test status and bail if error
989 dhcpv6_for_each_option(odata, odata + olen,
990 stype, slen, sdata) {
991 if (slen == 16 && (stype == NTP_MC_ADDR ||
992 stype == NTP_SRV_ADDR))
993 odhcp6c_add_state(STATE_NTP_IP,
994 sdata, slen);
995 else if (slen > 0 && stype == NTP_SRV_FQDN)
996 odhcp6c_add_state(STATE_NTP_FQDN,
997 sdata, slen);
998 }
999 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1000 if (olen == 16)
1001 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1002 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
1003 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1004 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1005 refresh = ntohl(*((uint32_t*)odata));
1006 passthru = false;
1007 } else if (otype == DHCPV6_OPT_AUTH) {
1008 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1009 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1010 if (r->protocol == 3 && r->algorithm == 1 &&
1011 r->reconf_type == 1)
1012 memcpy(reconf_key, r->key, sizeof(r->key));
1013 }
1014 passthru = false;
1015 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1016 size_t cur_len;
1017 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1018 if (cur_len == 0)
1019 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1020 passthru = false;
1021 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1022 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
1023 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1024 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1025 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1026 passthru = false;
1027 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1028 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
1029 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1030 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1031 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1032 passthru = false;
1033 #ifdef EXT_CER_ID
1034 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1035 sizeof(struct dhcpv6_cer_id)) {
1036 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1037 struct in6_addr any = IN6ADDR_ANY_INIT;
1038 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1039 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1040 passthru = false;
1041 #endif
1042 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1043 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1044 passthru = false;
1045 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1046 size_t mape_len;
1047 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1048 if (mape_len == 0)
1049 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1050 passthru = false;
1051 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1052 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1053 passthru = false;
1054 } else if (otype == DHCPV6_OPT_CLIENTID ||
1055 otype == DHCPV6_OPT_SERVERID ||
1056 otype == DHCPV6_OPT_IA_TA ||
1057 otype == DHCPV6_OPT_PREF ||
1058 otype == DHCPV6_OPT_UNICAST ||
1059 otype == DHCPV6_OPT_FQDN ||
1060 otype == DHCPV6_OPT_RECONF_ACCEPT) {
1061 passthru = false;
1062 } else {
1063 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1064 }
1065
1066 if (passthru)
1067 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1068 }
1069
1070 if (orig != DHCPV6_MSG_INFO_REQ) {
1071 // Update refresh timers if no fatal status code was received
1072 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1073 switch (orig) {
1074 case DHCPV6_MSG_RENEW:
1075 // Send further renews if T1 is not set
1076 if (!t1)
1077 ret = -1;
1078 break;
1079 case DHCPV6_MSG_REBIND:
1080 // Send further rebinds if T1 and T2 is not set
1081 if (!t1 && !t2)
1082 ret = -1;
1083 break;
1084
1085 case DHCPV6_MSG_REQUEST:
1086 // All server candidates can be cleared if not yet bound
1087 if (!odhcp6c_is_bound())
1088 dhcpv6_clear_all_server_cand();
1089
1090 default :
1091 break;
1092 }
1093 }
1094 }
1095 else if (ret > 0) {
1096 // All server candidates can be cleared if not yet bound
1097 if (!odhcp6c_is_bound())
1098 dhcpv6_clear_all_server_cand();
1099
1100 t1 = refresh;
1101 }
1102
1103 return ret;
1104 }
1105
1106
1107 static int dhcpv6_parse_ia(void *opt, void *end)
1108 {
1109 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1110 int parsed_ia = 0;
1111 uint32_t t1, t2;
1112 uint16_t otype, olen;
1113 uint8_t *odata;
1114
1115 t1 = ntohl(ia_hdr->t1);
1116 t2 = ntohl(ia_hdr->t2);
1117
1118 if (t1 > t2)
1119 return 0;
1120
1121 // Update address IA
1122 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1123 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1124 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1125
1126 entry.iaid = ia_hdr->iaid;
1127
1128 if (otype == DHCPV6_OPT_IA_PREFIX) {
1129 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1130 if (olen + 4U < sizeof(*prefix))
1131 continue;
1132
1133 entry.valid = ntohl(prefix->valid);
1134 entry.preferred = ntohl(prefix->preferred);
1135
1136 if (entry.preferred > entry.valid)
1137 continue;
1138
1139 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1140 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1141 if (entry.t1 > entry.t2)
1142 entry.t1 = entry.t2;
1143
1144 entry.length = prefix->prefix;
1145 entry.target = prefix->addr;
1146 uint16_t stype, slen;
1147 uint8_t *sdata;
1148
1149 #ifdef EXT_PREFIX_CLASS
1150 // Find prefix class, if any
1151 dhcpv6_for_each_option(&prefix[1], odata + olen,
1152 stype, slen, sdata)
1153 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1154 entry.class = sdata[0] << 8 | sdata[1];
1155 #endif
1156
1157 // Parse PD-exclude
1158 bool ok = true;
1159 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1160 odata + olen, stype, slen, sdata) {
1161 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1162 continue;
1163
1164 uint8_t elen = sdata[0];
1165 if (elen > 64)
1166 elen = 64;
1167
1168 if (elen <= 32 || elen <= entry.length) {
1169 ok = false;
1170 continue;
1171 }
1172
1173
1174 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1175 if (slen <= bytes) {
1176 ok = false;
1177 continue;
1178 }
1179
1180 uint32_t exclude = 0;
1181 do {
1182 exclude = exclude << 8 | sdata[bytes];
1183 } while (--bytes);
1184
1185 exclude >>= 8 - ((elen - entry.length) % 8);
1186 exclude <<= 64 - elen;
1187
1188 // Abusing router & priority fields for exclusion
1189 entry.router = entry.target;
1190 entry.router.s6_addr32[1] |= htonl(exclude);
1191 entry.priority = elen;
1192 }
1193
1194 if (ok) {
1195 odhcp6c_update_entry(STATE_IA_PD, &entry);
1196 parsed_ia++;
1197 }
1198
1199 entry.priority = 0;
1200 memset(&entry.router, 0, sizeof(entry.router));
1201 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1202 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1203 if (olen + 4U < sizeof(*addr))
1204 continue;
1205
1206 entry.preferred = ntohl(addr->preferred);
1207 entry.valid = ntohl(addr->valid);
1208
1209 if (entry.preferred > entry.valid)
1210 continue;
1211
1212 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1213 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1214 if (entry.t1 > entry.t2)
1215 entry.t1 = entry.t2;
1216
1217 entry.length = 128;
1218 entry.target = addr->addr;
1219
1220 #ifdef EXT_PREFIX_CLASS
1221 uint16_t stype, slen;
1222 uint8_t *sdata;
1223 // Find prefix class, if any
1224 dhcpv6_for_each_option(&addr[1], odata + olen,
1225 stype, slen, sdata)
1226 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1227 entry.class = sdata[0] << 8 | sdata[1];
1228 #endif
1229
1230 odhcp6c_update_entry(STATE_IA_NA, &entry);
1231 parsed_ia++;
1232 }
1233 }
1234 return parsed_ia;
1235 }
1236
1237
1238 static int dhcpv6_calc_refresh_timers(void)
1239 {
1240 struct odhcp6c_entry *e;
1241 size_t ia_na_entries, ia_pd_entries, i;
1242 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1243
1244 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1245 ia_na_entries /= sizeof(*e);
1246 for (i = 0; i < ia_na_entries; i++) {
1247 if (e[i].t1 < l_t1)
1248 l_t1 = e[i].t1;
1249
1250 if (e[i].t2 < l_t2)
1251 l_t2 = e[i].t2;
1252
1253 if (e[i].valid > l_t3)
1254 l_t3 = e[i].valid;
1255 }
1256
1257 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1258 ia_pd_entries /= sizeof(*e);
1259 for (i = 0; i < ia_pd_entries; i++) {
1260 if (e[i].t1 < l_t1)
1261 l_t1 = e[i].t1;
1262
1263 if (e[i].t2 < l_t2)
1264 l_t2 = e[i].t2;
1265
1266 if (e[i].valid > l_t3)
1267 l_t3 = e[i].valid;
1268 }
1269
1270 if (ia_pd_entries || ia_na_entries) {
1271 t1 = l_t1;
1272 t2 = l_t2;
1273 t3 = l_t3;
1274 } else {
1275 t1 = 600;
1276 }
1277
1278 return (int)(ia_pd_entries + ia_na_entries);
1279 }
1280
1281
1282 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1283 const void *status_msg, const int len)
1284 {
1285 uint8_t buf[len + 3];
1286
1287 memset(buf, 0, sizeof(buf));
1288 if (len) {
1289 buf[0] = '(';
1290 memcpy(&buf[1], status_msg, len);
1291 buf[len + 1] = ')';
1292 }
1293
1294 syslog(LOG_WARNING, "Server returned %s status %i %s",
1295 scope, code, buf);
1296 }
1297
1298
1299 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1300 const uint16_t code, const void *status_msg, const int len,
1301 int *ret)
1302 {
1303 dhcpv6_log_status_code(code, "message", status_msg, len);
1304
1305 switch (code) {
1306 case DHCPV6_UnspecFail:
1307 // Generic failure
1308 *ret = 0;
1309 break;
1310
1311 case DHCPV6_UseMulticast:
1312 // TODO handle multicast status code
1313 break;
1314
1315 case DHCPV6_NoAddrsAvail:
1316 case DHCPV6_NoPrefixAvail:
1317 if (orig == DHCPV6_MSG_REQUEST)
1318 *ret = 0; // Failure
1319 break;
1320
1321 default:
1322 break;
1323 }
1324 }
1325
1326
1327 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1328 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1329 const void *status_msg, const int len,
1330 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1331 {
1332 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1333 "IA_NA" : "IA_PD", status_msg, len);
1334
1335 switch (code) {
1336 case DHCPV6_NoBinding:
1337 switch (orig) {
1338 case DHCPV6_MSG_RENEW:
1339 case DHCPV6_MSG_REBIND:
1340 if ((*ret > 0) && !handled_status_codes[code])
1341 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1342 break;
1343
1344 default:
1345 break;
1346 }
1347 break;
1348
1349 case DHCPV6_NoAddrsAvail:
1350 case DHCPV6_NoPrefixAvail:
1351 switch (orig) {
1352 case DHCPV6_MSG_REQUEST:
1353 if (*ret != 0)
1354 *ret = 0;
1355 break;
1356 default:
1357 break;
1358 }
1359 break;
1360
1361 case DHCPV6_NotOnLink:
1362 // TODO handle not onlink in case of confirm
1363 break;
1364
1365 default:
1366 break;
1367 }
1368 }
1369
1370 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1371 {
1372 size_t cand_len, i;
1373 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1374
1375 // Remove identical duid server candidate
1376 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1377 if (cand->duid_len == c[i].duid_len &&
1378 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1379 free(c[i].ia_na);
1380 free(c[i].ia_pd);
1381 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1382 break;
1383 }
1384 }
1385
1386 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1387 i < cand_len / sizeof(*c); ++i) {
1388 if (c[i].preference < cand->preference)
1389 break;
1390 }
1391
1392 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1393 }
1394
1395 static void dhcpv6_clear_all_server_cand(void)
1396 {
1397 size_t cand_len, i;
1398 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1399
1400 // Server candidates need deep delete for IA_NA/IA_PD
1401 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1402 free(c[i].ia_na);
1403 free(c[i].ia_pd);
1404 }
1405 odhcp6c_clear_state(STATE_SERVER_CAND);
1406 }
1407
1408 int dhcpv6_promote_server_cand(void)
1409 {
1410 size_t cand_len;
1411 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1412 uint16_t hdr[2];
1413 int ret = DHCPV6_STATELESS;
1414
1415 // Clear lingering candidate state info
1416 odhcp6c_clear_state(STATE_SERVER_ID);
1417 odhcp6c_clear_state(STATE_IA_NA);
1418 odhcp6c_clear_state(STATE_IA_PD);
1419
1420 if (!cand_len)
1421 return -1;
1422
1423 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1424 na_mode = IA_MODE_NONE;
1425
1426 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1427 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1428
1429 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1430 }
1431
1432 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1433 hdr[1] = htons(cand->duid_len);
1434 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1435 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1436 accept_reconfig = cand->wants_reconfigure;
1437 if (cand->ia_na_len) {
1438 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1439 free(cand->ia_na);
1440 if (na_mode != IA_MODE_NONE)
1441 ret = DHCPV6_STATEFUL;
1442 }
1443 if (cand->ia_pd_len) {
1444 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1445 free(cand->ia_pd);
1446 if (request_prefix)
1447 ret = DHCPV6_STATEFUL;
1448 }
1449
1450 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1451 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1452
1453 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1454
1455 return ret;
1456 }
Openwrt DHCPv6 Client