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use enum to specify order and indexes of iov struct.
[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 };
180 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
181 }
182
183 // Configure IPv6-options
184 int val = 1;
185 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
186 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
187 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
188 val = 0;
189 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
190 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
191
192 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
193 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
194 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
195 return -1;
196
197 return 0;
198 }
199
200 enum {
201 IOV_HDR=0,
202 IOV_ORO,
203 IOV_ORO_REFRESH,
204 IOV_CL_ID,
205 IOV_SRV_ID,
206 IOV_VENDOR_CLASS_HDR,
207 IOV_VENDOR_CLASS,
208 IOV_USER_CLASS_HDR,
209 IOV_USER_CLASS,
210 IOV_RECONF_ACCEPT,
211 IOV_FQDN,
212 IOV_HDR_IA_NA,
213 IOV_IA_NA,
214 IOV_IA_PD,
215 IOV_TOTAL
216 };
217
218 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
219 {
220 na_mode = na;
221 pd_mode = pd;
222 }
223
224 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
225 {
226 // Build FQDN
227 char fqdn_buf[256];
228 gethostname(fqdn_buf, sizeof(fqdn_buf));
229 struct {
230 uint16_t type;
231 uint16_t len;
232 uint8_t flags;
233 uint8_t data[256];
234 } fqdn;
235 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
236 sizeof(fqdn.data), NULL, NULL);
237 fqdn.type = htons(DHCPV6_OPT_FQDN);
238 fqdn.len = htons(fqdn_len - 4);
239 fqdn.flags = 0;
240
241
242 // Build Client ID
243 size_t cl_id_len;
244 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
245
246 // Get Server ID
247 size_t srv_id_len;
248 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
249
250 // Build IA_PDs
251 size_t ia_pd_entries, ia_pd_len = 0;
252 uint8_t *ia_pd;
253
254 if (type == DHCPV6_MSG_SOLICIT) {
255 odhcp6c_clear_state(STATE_IA_PD);
256 size_t n_prefixes;
257 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
258 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
259
260 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
261
262 for (size_t i = 0; i < n_prefixes; i++) {
263 struct dhcpv6_ia_hdr hdr_ia_pd = {
264 htons(DHCPV6_OPT_IA_PD),
265 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
266 request_prefixes[i].iaid, 0, 0
267 };
268 struct dhcpv6_ia_prefix pref = {
269 .type = htons(DHCPV6_OPT_IA_PREFIX),
270 .len = htons(25), .prefix = request_prefixes[i].length
271 };
272 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
273 ia_pd_len += sizeof(hdr_ia_pd);
274 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
275 ia_pd_len += sizeof(pref);
276 }
277 } else {
278 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
279 ia_pd_entries /= sizeof(*e);
280
281 // we're too lazy to count our distinct IAIDs,
282 // so just allocate maximally needed space
283 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
284 sizeof(struct dhcpv6_ia_hdr)));
285
286 for (size_t i = 0; i < ia_pd_entries; ++i) {
287 uint32_t iaid = e[i].iaid;
288
289 // check if this is an unprocessed IAID and skip if not.
290 int new_iaid = 1;
291 for (int j = i-1; j >= 0; j--) {
292 if (e[j].iaid == iaid) {
293 new_iaid = 0;
294 break;
295 }
296 }
297
298 if (!new_iaid)
299 continue;
300
301 // construct header
302 struct dhcpv6_ia_hdr hdr_ia_pd = {
303 htons(DHCPV6_OPT_IA_PD),
304 htons(sizeof(hdr_ia_pd) - 4),
305 iaid, 0, 0
306 };
307
308 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
309 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
310 ia_pd_len += sizeof(hdr_ia_pd);
311
312 for (size_t j = i; j < ia_pd_entries; j++) {
313 if (e[j].iaid != iaid)
314 continue;
315
316 uint8_t ex_len = 0;
317 if (e[j].priority > 0)
318 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
319
320 struct dhcpv6_ia_prefix p = {
321 .type = htons(DHCPV6_OPT_IA_PREFIX),
322 .len = htons(sizeof(p) - 4U + ex_len),
323 .prefix = e[j].length,
324 .addr = e[j].target
325 };
326
327 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
328 ia_pd_len += sizeof(p);
329
330 if (ex_len) {
331 ia_pd[ia_pd_len++] = 0;
332 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
333 ia_pd[ia_pd_len++] = 0;
334 ia_pd[ia_pd_len++] = ex_len - 4;
335 ia_pd[ia_pd_len++] = e[j].priority;
336
337 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
338 excl >>= (64 - e[j].priority);
339 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
340
341 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
342 ia_pd[ia_pd_len + i] = excl & 0xff;
343 ia_pd_len += ex_len - 5;
344 }
345
346 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
347 }
348 }
349 }
350
351 if (ia_pd_entries > 0)
352 request_prefix = 1;
353
354 // Build IA_NAs
355 size_t ia_na_entries, ia_na_len = 0;
356 void *ia_na = NULL;
357 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
358 ia_na_entries /= sizeof(*e);
359
360 struct dhcpv6_ia_hdr hdr_ia_na = {
361 htons(DHCPV6_OPT_IA_NA),
362 htons(sizeof(hdr_ia_na) - 4),
363 1, 0, 0
364 };
365
366 struct dhcpv6_ia_addr pa[ia_na_entries];
367 for (size_t i = 0; i < ia_na_entries; ++i) {
368 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
369 pa[i].len = htons(sizeof(pa[i]) - 4U);
370 pa[i].addr = e[i].target;
371 pa[i].preferred = 0;
372 pa[i].valid = 0;
373 }
374
375 ia_na = pa;
376 ia_na_len = sizeof(pa);
377 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
378
379 // Reconfigure Accept
380 struct {
381 uint16_t type;
382 uint16_t length;
383 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
384
385 // Request Information Refresh
386 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
387
388 // Build vendor-class option
389 size_t vendor_class_len, user_class_len;
390 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
391 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
392
393 struct {
394 uint16_t type;
395 uint16_t length;
396 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
397
398 struct {
399 uint16_t type;
400 uint16_t length;
401 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
402
403 // Prepare Header
404 size_t oro_len;
405 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
406 struct {
407 uint8_t type;
408 uint8_t trid[3];
409 uint16_t elapsed_type;
410 uint16_t elapsed_len;
411 uint16_t elapsed_value;
412 uint16_t oro_type;
413 uint16_t oro_len;
414 } hdr = {
415 type, {trid[0], trid[1], trid[2]},
416 htons(DHCPV6_OPT_ELAPSED), htons(2),
417 htons((ecs > 0xffff) ? 0xffff : ecs),
418 htons(DHCPV6_OPT_ORO), htons(oro_len),
419 };
420
421 struct iovec iov[IOV_TOTAL] = {
422 [IOV_HDR] = {&hdr, sizeof(hdr)},
423 [IOV_ORO] = {oro, oro_len},
424 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
425 [IOV_CL_ID] = {cl_id, cl_id_len},
426 [IOV_SRV_ID] = {srv_id, srv_id_len},
427 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
428 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
429 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
430 [IOV_USER_CLASS] = {user_class, user_class_len},
431 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
432 [IOV_FQDN] = {&fqdn, fqdn_len},
433 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
434 [IOV_IA_NA] = {ia_na, ia_na_len},
435 [IOV_IA_PD] = {ia_pd, ia_pd_len},
436 };
437
438 size_t cnt = IOV_TOTAL;
439 if (type == DHCPV6_MSG_INFO_REQ) {
440 cnt = 9;
441 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
442 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
443 } else if (!request_prefix) {
444 cnt = 13;
445 }
446
447 // Disable IAs if not used
448 if (type != DHCPV6_MSG_SOLICIT) {
449 iov[IOV_RECONF_ACCEPT].iov_len = 0;
450 if (ia_na_len == 0)
451 iov[IOV_HDR_IA_NA].iov_len = 0;
452 }
453
454 if (na_mode == IA_MODE_NONE)
455 iov[IOV_HDR_IA_NA].iov_len = 0;
456
457 if (!(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[16], hash[16];
663 memcpy(serverhash, r->key, sizeof(serverhash));
664 memset(r->key, 0, sizeof(r->key));
665 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
666
667 for (size_t i = 0; i < sizeof(secretbytes); ++i)
668 secretbytes[i] ^= 0x36;
669
670 md5_begin(&md5);
671 md5_hash(secretbytes, sizeof(secretbytes), &md5);
672 md5_hash(buf, len, &md5);
673 md5_end(hash, &md5);
674
675 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
676 secretbytes[i] ^= 0x36;
677 secretbytes[i] ^= 0x5c;
678 }
679
680 md5_begin(&md5);
681 md5_hash(secretbytes, sizeof(secretbytes), &md5);
682 md5_hash(hash, 16, &md5);
683 md5_end(hash, &md5);
684
685 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
686 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
687 rcmsg = odata[0];
688 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
689 ia_present = true;
690 if (olen < sizeof(struct dhcpv6_ia_hdr))
691 options_valid = false;
692 }
693 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
694 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
695 // Options are not allowed on global level
696 options_valid = false;
697 }
698 }
699
700 if (!options_valid || ((odata + olen) > end))
701 return false;
702
703 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
704 return false;
705
706 if (rep->msg_type == DHCPV6_MSG_RECONF) {
707 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
708 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
709 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
710 return false;
711 }
712
713 return clientid_ok && serverid_ok;
714 }
715
716
717 int dhcpv6_poll_reconfigure(void)
718 {
719 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
720 if (ret != -1)
721 ret = dhcpv6_request(ret);
722
723 return ret;
724 }
725
726
727 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
728 const void *opt, const void *end)
729 {
730 uint16_t otype, olen;
731 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
732 dhcpv6_for_each_option(opt, end, otype, olen, odata)
733 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
734 odata[0] == DHCPV6_MSG_RENEW ||
735 odata[0] == DHCPV6_MSG_INFO_REQ))
736 msg = odata[0];
737
738 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
739 return msg;
740 }
741
742
743 // Collect all advertised servers
744 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
745 const void *opt, const void *end)
746 {
747 uint16_t olen, otype;
748 uint8_t *odata, pref = 0;
749 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
750 DHCPV6_SOL_MAX_RT,
751 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
752 bool have_na = false;
753 int have_pd = 0;
754
755 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
756 if (orig == DHCPV6_MSG_SOLICIT &&
757 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
758 olen > sizeof(struct dhcpv6_ia_hdr)) {
759 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
760 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
761 }
762
763 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
764 memcpy(cand.duid, odata, olen);
765 cand.duid_len = olen;
766 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
767 int error = ((int)odata[0] << 8 | (int)odata[1]);
768
769 switch (error) {
770 case DHCPV6_NoPrefixAvail:
771 // Status code on global level
772 cand.preference -= 2000;
773 break;
774
775 default :
776 break;
777 }
778 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
779 cand.preference >= 0) {
780 cand.preference = pref = odata[0];
781 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
782 cand.wants_reconfigure = true;
783 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
784 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
785 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
786 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
787 cand.sol_max_rt = sol_max_rt;
788 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
789 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
790 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
791 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
792 cand.inf_max_rt = inf_max_rt;
793 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
794 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
795 uint8_t *oend = odata + olen, *d;
796 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
797 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
798 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
799 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
800 have_pd = p->prefix;
801 }
802 }
803 } else if (otype == DHCPV6_OPT_IA_NA) {
804 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
805 uint8_t *oend = odata + olen, *d;
806 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
807 if (otype == DHCPV6_OPT_IA_ADDR)
808 have_na = true;
809 }
810 }
811
812 if ((!have_na && na_mode == IA_MODE_FORCE) ||
813 (!have_pd && pd_mode == IA_MODE_FORCE)) {
814 /*
815 * RFC7083 states to process the SOL_MAX_RT and
816 * INF_MAX_RT options even if the DHCPv6 server
817 * did not propose any IA_NA and/or IA_PD
818 */
819 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
820 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
821 return -1;
822 }
823
824 if (na_mode != IA_MODE_NONE && !have_na) {
825 cand.has_noaddravail = true;
826 cand.preference -= 1000;
827 }
828
829 if (pd_mode != IA_MODE_NONE) {
830 if (have_pd)
831 cand.preference += 2000 + (128 - have_pd);
832 else
833 cand.preference -= 2000;
834 }
835
836 if (cand.duid_len > 0) {
837 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
838 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
839 dhcpv6_add_server_cand(&cand);
840 }
841
842 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
843 }
844
845
846 static int dhcpv6_commit_advert(void)
847 {
848 return dhcpv6_promote_server_cand();
849 }
850
851
852 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
853 const void *opt, const void *end)
854 {
855 dhcpv6_handle_advert(orig, rc, opt, end);
856 if (dhcpv6_commit_advert() < 0)
857 return -1;
858
859 return dhcpv6_handle_reply(orig, rc, opt, end);
860 }
861
862
863 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
864 const void *opt, const void *end)
865 {
866 uint8_t *odata;
867 uint16_t otype, olen;
868 uint32_t refresh = UINT32_MAX;
869 int ret = 1;
870 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
871
872 odhcp6c_expire();
873
874 if (orig == DHCPV6_MSG_UNKNOWN) {
875 static time_t last_update = 0;
876 time_t now = odhcp6c_get_milli_time() / 1000;
877
878 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
879 last_update = now;
880
881 if (t1 != UINT32_MAX)
882 t1 -= elapsed;
883
884 if (t2 != UINT32_MAX)
885 t2 -= elapsed;
886
887 if (t3 != UINT32_MAX)
888 t3 -= elapsed;
889
890 if (t1 < 0)
891 t1 = 0;
892
893 if (t2 < 0)
894 t2 = 0;
895
896 if (t3 < 0)
897 t3 = 0;
898 }
899
900 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
901 // Delete NA and PD we have in the state from the Advert
902 odhcp6c_clear_state(STATE_IA_NA);
903 odhcp6c_clear_state(STATE_IA_PD);
904 }
905
906 if (opt) {
907 odhcp6c_clear_state(STATE_DNS);
908 odhcp6c_clear_state(STATE_SEARCH);
909 odhcp6c_clear_state(STATE_SNTP_IP);
910 odhcp6c_clear_state(STATE_NTP_IP);
911 odhcp6c_clear_state(STATE_NTP_FQDN);
912 odhcp6c_clear_state(STATE_SIP_IP);
913 odhcp6c_clear_state(STATE_SIP_FQDN);
914 odhcp6c_clear_state(STATE_AFTR_NAME);
915 }
916
917 // Parse and find all matching IAs
918 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
919 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
920 && olen > sizeof(struct dhcpv6_ia_hdr)) {
921 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
922
923 // Test ID
924 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
925 continue;
926
927 uint16_t code = DHCPV6_Success;
928 uint16_t stype, slen;
929 uint8_t *sdata;
930 // Get and handle status code
931 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
932 stype, slen, sdata) {
933 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
934 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
935 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
936
937 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
938
939 if (code == DHCPV6_Success)
940 continue;
941
942 dhcpv6_handle_ia_status_code(orig, ia_hdr,
943 code, mdata, mlen, handled_status_codes, &ret);
944
945
946 if (ret > 0)
947 return ret;
948 break;
949 }
950 }
951
952 if (code != DHCPV6_Success)
953 continue;
954
955 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
956 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
957 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
958 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
959 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
960
961 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
962 }
963 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
964 if (olen % 16 == 0)
965 odhcp6c_add_state(STATE_DNS, odata, olen);
966 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
967 odhcp6c_add_state(STATE_SEARCH, odata, olen);
968 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
969 if (olen % 16 == 0)
970 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
971 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
972 uint16_t stype, slen;
973 uint8_t *sdata;
974 // Test status and bail if error
975 dhcpv6_for_each_option(odata, odata + olen,
976 stype, slen, sdata) {
977 if (slen == 16 && (stype == NTP_MC_ADDR ||
978 stype == NTP_SRV_ADDR))
979 odhcp6c_add_state(STATE_NTP_IP,
980 sdata, slen);
981 else if (slen > 0 && stype == NTP_SRV_FQDN)
982 odhcp6c_add_state(STATE_NTP_FQDN,
983 sdata, slen);
984 }
985 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
986 if (olen == 16)
987 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
988 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
989 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
990 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
991 refresh = ntohl(*((uint32_t*)odata));
992 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
993 sizeof(struct dhcpv6_auth_reconfigure)) {
994 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
995 if (r->protocol == 3 && r->algorithm == 1 &&
996 r->reconf_type == 1)
997 memcpy(reconf_key, r->key, sizeof(r->key));
998 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
999 size_t cur_len;
1000 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1001 if (cur_len == 0)
1002 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1003 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1004 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
1005 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1006 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1007 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1008 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1009 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
1010 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1011 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1012 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1013 }else if (otype != DHCPV6_OPT_CLIENTID &&
1014 otype != DHCPV6_OPT_SERVERID) {
1015 odhcp6c_add_state(STATE_CUSTOM_OPTS,
1016 &odata[-4], olen + 4);
1017 }
1018 }
1019
1020 if (orig != DHCPV6_MSG_INFO_REQ) {
1021 // Update refresh timers if no fatal status code was received
1022 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1023 switch (orig) {
1024 case DHCPV6_MSG_RENEW:
1025 // Send further renews if T1 is not set
1026 if (!t1)
1027 ret = -1;
1028 break;
1029 case DHCPV6_MSG_REBIND:
1030 // Send further rebinds if T1 and T2 is not set
1031 if (!t1 && !t2)
1032 ret = -1;
1033 break;
1034
1035 case DHCPV6_MSG_REQUEST:
1036 // All server candidates can be cleared if not yet bound
1037 if (!odhcp6c_is_bound())
1038 dhcpv6_clear_all_server_cand();
1039
1040 default :
1041 break;
1042 }
1043 }
1044 }
1045 else if (ret > 0) {
1046 // All server candidates can be cleared if not yet bound
1047 if (!odhcp6c_is_bound())
1048 dhcpv6_clear_all_server_cand();
1049
1050 t1 = refresh;
1051 }
1052
1053 return ret;
1054 }
1055
1056
1057 static int dhcpv6_parse_ia(void *opt, void *end)
1058 {
1059 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1060 int parsed_ia = 0;
1061 uint32_t t1, t2;
1062 uint16_t otype, olen;
1063 uint8_t *odata;
1064
1065 t1 = ntohl(ia_hdr->t1);
1066 t2 = ntohl(ia_hdr->t2);
1067
1068 if (t1 > t2)
1069 return 0;
1070
1071 // Update address IA
1072 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1073 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1074 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1075
1076 entry.iaid = ia_hdr->iaid;
1077
1078 if (otype == DHCPV6_OPT_IA_PREFIX) {
1079 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1080 if (olen + 4U < sizeof(*prefix))
1081 continue;
1082
1083 entry.valid = ntohl(prefix->valid);
1084 entry.preferred = ntohl(prefix->preferred);
1085
1086 if (entry.preferred > entry.valid)
1087 continue;
1088
1089 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1090 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1091 if (entry.t1 > entry.t2)
1092 entry.t1 = entry.t2;
1093
1094 entry.length = prefix->prefix;
1095 entry.target = prefix->addr;
1096 uint16_t stype, slen;
1097 uint8_t *sdata;
1098
1099 #ifdef EXT_PREFIX_CLASS
1100 // Find prefix class, if any
1101 dhcpv6_for_each_option(&prefix[1], odata + olen,
1102 stype, slen, sdata)
1103 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1104 entry.class = sdata[0] << 8 | sdata[1];
1105 #endif
1106
1107 // Parse PD-exclude
1108 bool ok = true;
1109 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1110 odata + olen, stype, slen, sdata) {
1111 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1112 continue;
1113
1114 uint8_t elen = sdata[0];
1115 if (elen > 64)
1116 elen = 64;
1117
1118 if (elen <= 32 || elen <= entry.length) {
1119 ok = false;
1120 continue;
1121 }
1122
1123
1124 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1125 if (slen <= bytes) {
1126 ok = false;
1127 continue;
1128 }
1129
1130 uint32_t exclude = 0;
1131 do {
1132 exclude = exclude << 8 | sdata[bytes];
1133 } while (--bytes);
1134
1135 exclude >>= 8 - ((elen - entry.length) % 8);
1136 exclude <<= 64 - elen;
1137
1138 // Abusing router & priority fields for exclusion
1139 entry.router = entry.target;
1140 entry.router.s6_addr32[1] |= htonl(exclude);
1141 entry.priority = elen;
1142 }
1143
1144 if (ok) {
1145 odhcp6c_update_entry(STATE_IA_PD, &entry);
1146 parsed_ia++;
1147 }
1148
1149 entry.priority = 0;
1150 memset(&entry.router, 0, sizeof(entry.router));
1151 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1152 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1153 if (olen + 4U < sizeof(*addr))
1154 continue;
1155
1156 entry.preferred = ntohl(addr->preferred);
1157 entry.valid = ntohl(addr->valid);
1158
1159 if (entry.preferred > entry.valid)
1160 continue;
1161
1162 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1163 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1164 if (entry.t1 > entry.t2)
1165 entry.t1 = entry.t2;
1166
1167 entry.length = 128;
1168 entry.target = addr->addr;
1169
1170 #ifdef EXT_PREFIX_CLASS
1171 uint16_t stype, slen;
1172 uint8_t *sdata;
1173 // Find prefix class, if any
1174 dhcpv6_for_each_option(&addr[1], odata + olen,
1175 stype, slen, sdata)
1176 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1177 entry.class = sdata[0] << 8 | sdata[1];
1178 #endif
1179
1180 odhcp6c_update_entry(STATE_IA_NA, &entry);
1181 parsed_ia++;
1182 }
1183 }
1184 return parsed_ia;
1185 }
1186
1187
1188 static int dhcpv6_calc_refresh_timers(void)
1189 {
1190 struct odhcp6c_entry *e;
1191 size_t ia_na_entries, ia_pd_entries, i;
1192 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1193
1194 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1195 ia_na_entries /= sizeof(*e);
1196 for (i = 0; i < ia_na_entries; i++) {
1197 if (e[i].t1 < l_t1)
1198 l_t1 = e[i].t1;
1199
1200 if (e[i].t2 < l_t2)
1201 l_t2 = e[i].t2;
1202
1203 if (e[i].valid > l_t3)
1204 l_t3 = e[i].valid;
1205 }
1206
1207 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1208 ia_pd_entries /= sizeof(*e);
1209 for (i = 0; i < ia_pd_entries; i++) {
1210 if (e[i].t1 < l_t1)
1211 l_t1 = e[i].t1;
1212
1213 if (e[i].t2 < l_t2)
1214 l_t2 = e[i].t2;
1215
1216 if (e[i].valid > l_t3)
1217 l_t3 = e[i].valid;
1218 }
1219
1220 if (ia_pd_entries || ia_na_entries) {
1221 t1 = l_t1;
1222 t2 = l_t2;
1223 t3 = l_t3;
1224 } else {
1225 t1 = 600;
1226 }
1227
1228 return (int)(ia_pd_entries + ia_na_entries);
1229 }
1230
1231
1232 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1233 const void *status_msg, const int len)
1234 {
1235 uint8_t buf[len + 3];
1236
1237 memset(buf, 0, sizeof(buf));
1238 if (len) {
1239 buf[0] = '(';
1240 memcpy(&buf[1], status_msg, len);
1241 buf[len + 1] = ')';
1242 }
1243
1244 syslog(LOG_WARNING, "Server returned %s status %i %s",
1245 scope, code, buf);
1246 }
1247
1248
1249 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1250 const uint16_t code, const void *status_msg, const int len,
1251 int *ret)
1252 {
1253 dhcpv6_log_status_code(code, "message", status_msg, len);
1254
1255 switch (code) {
1256 case DHCPV6_UnspecFail:
1257 // Generic failure
1258 *ret = 0;
1259 break;
1260
1261 case DHCPV6_UseMulticast:
1262 // TODO handle multicast status code
1263 break;
1264
1265 case DHCPV6_NoAddrsAvail:
1266 case DHCPV6_NoPrefixAvail:
1267 if (orig == DHCPV6_MSG_REQUEST)
1268 *ret = 0; // Failure
1269 break;
1270
1271 default:
1272 break;
1273 }
1274 }
1275
1276
1277 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1278 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1279 const void *status_msg, const int len,
1280 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1281 {
1282 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1283 "IA_NA" : "IA_PD", status_msg, len);
1284
1285 switch (code) {
1286 case DHCPV6_NoBinding:
1287 switch (orig) {
1288 case DHCPV6_MSG_RENEW:
1289 case DHCPV6_MSG_REBIND:
1290 if ((*ret > 0) && !handled_status_codes[code])
1291 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1292 break;
1293
1294 default:
1295 break;
1296 }
1297 break;
1298
1299 case DHCPV6_NoAddrsAvail:
1300 case DHCPV6_NoPrefixAvail:
1301 switch (orig) {
1302 case DHCPV6_MSG_REQUEST:
1303 if (*ret != 0)
1304 *ret = 0;
1305 break;
1306 default:
1307 break;
1308 }
1309 break;
1310
1311 case DHCPV6_NotOnLink:
1312 // TODO handle not onlink in case of confirm
1313 break;
1314
1315 default:
1316 break;
1317 }
1318 }
1319
1320 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1321 {
1322 size_t cand_len, i;
1323 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1324
1325 // Remove identical duid server candidate
1326 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1327 if (cand->duid_len == c[i].duid_len &&
1328 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1329 free(c[i].ia_na);
1330 free(c[i].ia_pd);
1331 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1332 break;
1333 }
1334 }
1335
1336 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1337 i < cand_len / sizeof(*c); ++i) {
1338 if (c[i].preference < cand->preference)
1339 break;
1340 }
1341
1342 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1343 }
1344
1345 static void dhcpv6_clear_all_server_cand(void)
1346 {
1347 size_t cand_len, i;
1348 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1349
1350 // Server candidates need deep delete for IA_NA/IA_PD
1351 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1352 free(c[i].ia_na);
1353 free(c[i].ia_pd);
1354 }
1355 odhcp6c_clear_state(STATE_SERVER_CAND);
1356 }
1357
1358 int dhcpv6_promote_server_cand(void)
1359 {
1360 size_t cand_len;
1361 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1362 uint16_t hdr[2];
1363 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1364 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1365
1366 // Clear lingering candidate state info
1367 odhcp6c_clear_state(STATE_SERVER_ID);
1368 odhcp6c_clear_state(STATE_IA_NA);
1369 odhcp6c_clear_state(STATE_IA_PD);
1370
1371 if (!cand_len)
1372 return -1;
1373
1374 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1375 na_mode = IA_MODE_NONE;
1376
1377 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1378 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1379
1380 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1381 }
1382
1383 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1384 hdr[1] = htons(cand->duid_len);
1385 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1386 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1387 accept_reconfig = cand->wants_reconfigure;
1388 if (cand->ia_na_len) {
1389 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1390 free(cand->ia_na);
1391 if (na_mode != IA_MODE_NONE)
1392 ret = DHCPV6_STATEFUL;
1393 }
1394 if (cand->ia_pd_len) {
1395 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1396 free(cand->ia_pd);
1397 if (request_prefix)
1398 ret = DHCPV6_STATEFUL;
1399 }
1400
1401 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1402 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1403
1404 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1405
1406 return ret;
1407 }
Openwrt DHCPv6 Client