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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 <ctype.h>
27 #include <sys/time.h>
28 #include <sys/ioctl.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31
32 #include <net/if.h>
33 #include <net/ethernet.h>
34
35 #include "odhcp6c.h"
36 #ifdef LIBUBOX
37 #include <libubox/md5.h>
38 #else
39 #include "md5.h"
40 #endif
41
42
43 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
44 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
45 #define DHCPV6_CLIENT_PORT 546
46 #define DHCPV6_SERVER_PORT 547
47 #define DHCPV6_DUID_LLADDR 3
48 #define DHCPV6_REQ_DELAY 1
49
50 #define DHCPV6_SOL_MAX_RT_MIN 60
51 #define DHCPV6_SOL_MAX_RT_MAX 86400
52 #define DHCPV6_INF_MAX_RT_MIN 60
53 #define DHCPV6_INF_MAX_RT_MAX 86400
54
55 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
56 const uint8_t transaction[3], enum dhcpv6_msg type,
57 const struct in6_addr *daddr);
58
59 static int dhcpv6_parse_ia(void *opt, void *end);
60
61 static int dhcpv6_calc_refresh_timers(void);
62 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
63 const uint16_t code, const void *status_msg, const int len,
64 int *ret);
65 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
66 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
67 const void *status_msg, const int len,
68 bool handled_status_codes[_DHCPV6_Status_Max],
69 int *ret);
70 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
71 static void dhcpv6_clear_all_server_cand(void);
72
73 static reply_handler dhcpv6_handle_reply;
74 static reply_handler dhcpv6_handle_advert;
75 static reply_handler dhcpv6_handle_rebind_reply;
76 static reply_handler dhcpv6_handle_reconfigure;
77 static int dhcpv6_commit_advert(void);
78
79
80
81 // RFC 3315 - 5.5 Timeout and Delay values
82 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
83 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
84 dhcpv6_handle_reconfigure, NULL},
85 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
86 dhcpv6_handle_advert, dhcpv6_commit_advert},
87 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
88 dhcpv6_handle_reply, NULL},
89 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
90 dhcpv6_handle_reply, NULL},
91 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
92 dhcpv6_handle_rebind_reply, NULL},
93 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
94 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
95 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
96 dhcpv6_handle_reply, NULL},
97 };
98
99
100 // Sockets
101 static int sock = -1;
102 static int ifindex = -1;
103 static int64_t t1 = 0, t2 = 0, t3 = 0;
104
105 // IA states
106 static int request_prefix = -1;
107 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
108 static bool accept_reconfig = false;
109
110 // Reconfigure key
111 static uint8_t reconf_key[16];
112
113 // client options
114 static unsigned int client_options = 0;
115
116
117 static uint32_t ntohl_unaligned(const uint8_t *data)
118 {
119 uint32_t buf;
120
121 memcpy(&buf, data, sizeof(buf));
122 return ntohl(buf);
123 }
124
125 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
126 {
127 client_options = options;
128 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
129
130 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
131 if (sock < 0)
132 return -1;
133
134 // Detect interface
135 struct ifreq ifr;
136 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
137 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
138 return -1;
139 ifindex = ifr.ifr_ifindex;
140
141 // Create client DUID
142 size_t client_id_len;
143 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
144 if (client_id_len == 0) {
145 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
146 DHCPV6_DUID_LLADDR, 0, 1};
147
148 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
149 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
150
151 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
152 struct ifreq ifs[100], *ifp, *ifend;
153 struct ifconf ifc;
154 ifc.ifc_req = ifs;
155 ifc.ifc_len = sizeof(ifs);
156
157 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
158 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
159 // If our interface doesn't have an address...
160 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
161 for (ifp = ifc.ifc_req; ifp < ifend &&
162 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
163 memcpy(ifr.ifr_name, ifp->ifr_name,
164 sizeof(ifr.ifr_name));
165 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
166 continue;
167
168 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
169 ETHER_ADDR_LEN);
170 }
171 }
172
173 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
174 }
175
176 // Create ORO
177 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
178 uint16_t oro[] = {
179 htons(DHCPV6_OPT_SIP_SERVER_D),
180 htons(DHCPV6_OPT_SIP_SERVER_A),
181 htons(DHCPV6_OPT_DNS_SERVERS),
182 htons(DHCPV6_OPT_DNS_DOMAIN),
183 htons(DHCPV6_OPT_SNTP_SERVERS),
184 htons(DHCPV6_OPT_NTP_SERVER),
185 htons(DHCPV6_OPT_AFTR_NAME),
186 htons(DHCPV6_OPT_PD_EXCLUDE),
187 htons(DHCPV6_OPT_SOL_MAX_RT),
188 htons(DHCPV6_OPT_INF_MAX_RT),
189 #ifdef EXT_CER_ID
190 htons(DHCPV6_OPT_CER_ID),
191 #endif
192 htons(DHCPV6_OPT_S46_CONT_MAPE),
193 htons(DHCPV6_OPT_S46_CONT_MAPT),
194 htons(DHCPV6_OPT_S46_CONT_LW),
195 };
196 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
197 }
198
199 // Configure IPv6-options
200 int val = 1;
201 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
202 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
203 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
204 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
205
206 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
207 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
208 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
209 return -1;
210
211 return 0;
212 }
213
214 enum {
215 IOV_HDR=0,
216 IOV_ORO,
217 IOV_ORO_REFRESH,
218 IOV_CL_ID,
219 IOV_SRV_ID,
220 IOV_VENDOR_CLASS_HDR,
221 IOV_VENDOR_CLASS,
222 IOV_USER_CLASS_HDR,
223 IOV_USER_CLASS,
224 IOV_RECONF_ACCEPT,
225 IOV_FQDN,
226 IOV_HDR_IA_NA,
227 IOV_IA_NA,
228 IOV_IA_PD,
229 IOV_TOTAL
230 };
231
232 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
233 {
234 int mode = DHCPV6_UNKNOWN;
235
236 na_mode = na;
237 pd_mode = pd;
238
239 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
240 mode = DHCPV6_STATELESS;
241 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
242 mode = DHCPV6_STATEFUL;
243
244 return mode;
245 }
246
247 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
248 {
249 // Build FQDN
250 char fqdn_buf[256];
251 gethostname(fqdn_buf, sizeof(fqdn_buf));
252 struct {
253 uint16_t type;
254 uint16_t len;
255 uint8_t flags;
256 uint8_t data[256];
257 } fqdn;
258 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
259 sizeof(fqdn.data), NULL, NULL);
260 fqdn.type = htons(DHCPV6_OPT_FQDN);
261 fqdn.len = htons(fqdn_len - 4);
262 fqdn.flags = 0;
263
264
265 // Build Client ID
266 size_t cl_id_len;
267 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
268
269 // Get Server ID
270 size_t srv_id_len;
271 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
272
273 // Build IA_PDs
274 size_t ia_pd_entries = 0, ia_pd_len = 0;
275 uint8_t *ia_pd;
276
277 if (type == DHCPV6_MSG_SOLICIT) {
278 odhcp6c_clear_state(STATE_IA_PD);
279 size_t n_prefixes;
280 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
281 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
282
283 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
284
285 for (size_t i = 0; i < n_prefixes; i++) {
286 struct dhcpv6_ia_hdr hdr_ia_pd = {
287 htons(DHCPV6_OPT_IA_PD),
288 htons(sizeof(hdr_ia_pd) - 4 +
289 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
290 request_prefixes[i].iaid, 0, 0
291 };
292 struct dhcpv6_ia_prefix pref = {
293 .type = htons(DHCPV6_OPT_IA_PREFIX),
294 .len = htons(sizeof(pref) - 4),
295 .prefix = request_prefixes[i].length
296 };
297 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
298 ia_pd_len += sizeof(hdr_ia_pd);
299 if (request_prefixes[i].length) {
300 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
301 ia_pd_len += sizeof(pref);
302 }
303 }
304 } else {
305 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
306 ia_pd_entries /= sizeof(*e);
307
308 // we're too lazy to count our distinct IAIDs,
309 // so just allocate maximally needed space
310 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
311 sizeof(struct dhcpv6_ia_hdr)));
312
313 for (size_t i = 0; i < ia_pd_entries; ++i) {
314 uint32_t iaid = e[i].iaid;
315
316 // check if this is an unprocessed IAID and skip if not.
317 int new_iaid = 1;
318 for (int j = i-1; j >= 0; j--) {
319 if (e[j].iaid == iaid) {
320 new_iaid = 0;
321 break;
322 }
323 }
324
325 if (!new_iaid)
326 continue;
327
328 // construct header
329 struct dhcpv6_ia_hdr hdr_ia_pd = {
330 htons(DHCPV6_OPT_IA_PD),
331 htons(sizeof(hdr_ia_pd) - 4),
332 iaid, 0, 0
333 };
334
335 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
336 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
337 ia_pd_len += sizeof(hdr_ia_pd);
338
339 for (size_t j = i; j < ia_pd_entries; j++) {
340 if (e[j].iaid != iaid)
341 continue;
342
343 uint8_t ex_len = 0;
344 if (e[j].priority > 0)
345 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
346
347 struct dhcpv6_ia_prefix p = {
348 .type = htons(DHCPV6_OPT_IA_PREFIX),
349 .len = htons(sizeof(p) - 4U + ex_len),
350 .prefix = e[j].length,
351 .addr = e[j].target
352 };
353
354 if (type == DHCPV6_MSG_REQUEST) {
355 p.preferred = htonl(e[j].preferred);
356 p.valid = htonl(e[j].valid);
357 }
358
359 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
360 ia_pd_len += sizeof(p);
361
362 if (ex_len) {
363 ia_pd[ia_pd_len++] = 0;
364 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
365 ia_pd[ia_pd_len++] = 0;
366 ia_pd[ia_pd_len++] = ex_len - 4;
367 ia_pd[ia_pd_len++] = e[j].priority;
368
369 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
370 excl >>= (64 - e[j].priority);
371 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
372
373 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
374 ia_pd[ia_pd_len + i] = excl & 0xff;
375 ia_pd_len += ex_len - 5;
376 }
377
378 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
379 }
380 }
381 }
382
383 if (ia_pd_entries > 0)
384 request_prefix = 1;
385
386 // Build IA_NAs
387 size_t ia_na_entries, ia_na_len = 0;
388 void *ia_na = NULL;
389 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
390 ia_na_entries /= sizeof(*e);
391
392 struct dhcpv6_ia_hdr hdr_ia_na = {
393 htons(DHCPV6_OPT_IA_NA),
394 htons(sizeof(hdr_ia_na) - 4),
395 htonl(1), 0, 0
396 };
397
398 struct dhcpv6_ia_addr pa[ia_na_entries];
399 for (size_t i = 0; i < ia_na_entries; ++i) {
400 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
401 pa[i].len = htons(sizeof(pa[i]) - 4U);
402 pa[i].addr = e[i].target;
403
404 if (type == DHCPV6_MSG_REQUEST) {
405 pa[i].preferred = htonl(e[i].preferred);
406 pa[i].valid = htonl(e[i].valid);
407 } else {
408 pa[i].preferred = 0;
409 pa[i].valid = 0;
410 }
411 }
412
413 ia_na = pa;
414 ia_na_len = sizeof(pa);
415 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
416
417 // Reconfigure Accept
418 struct {
419 uint16_t type;
420 uint16_t length;
421 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
422
423 // Request Information Refresh
424 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
425
426 // Build vendor-class option
427 size_t vendor_class_len, user_class_len;
428 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
429 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
430
431 struct {
432 uint16_t type;
433 uint16_t length;
434 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
435
436 struct {
437 uint16_t type;
438 uint16_t length;
439 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
440
441 // Prepare Header
442 size_t oro_len;
443 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
444 struct {
445 uint8_t type;
446 uint8_t trid[3];
447 uint16_t elapsed_type;
448 uint16_t elapsed_len;
449 uint16_t elapsed_value;
450 uint16_t oro_type;
451 uint16_t oro_len;
452 } hdr = {
453 type, {trid[0], trid[1], trid[2]},
454 htons(DHCPV6_OPT_ELAPSED), htons(2),
455 htons((ecs > 0xffff) ? 0xffff : ecs),
456 htons(DHCPV6_OPT_ORO), htons(oro_len),
457 };
458
459 struct iovec iov[IOV_TOTAL] = {
460 [IOV_HDR] = {&hdr, sizeof(hdr)},
461 [IOV_ORO] = {oro, oro_len},
462 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
463 [IOV_CL_ID] = {cl_id, cl_id_len},
464 [IOV_SRV_ID] = {srv_id, srv_id_len},
465 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
466 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
467 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
468 [IOV_USER_CLASS] = {user_class, user_class_len},
469 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
470 [IOV_FQDN] = {&fqdn, fqdn_len},
471 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
472 [IOV_IA_NA] = {ia_na, ia_na_len},
473 [IOV_IA_PD] = {ia_pd, ia_pd_len},
474 };
475
476 size_t cnt = IOV_TOTAL;
477 if (type == DHCPV6_MSG_INFO_REQ) {
478 cnt = 9;
479 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
480 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
481 } else if (!request_prefix) {
482 cnt = 13;
483 }
484
485 // Disable IAs if not used
486 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
487 iov[IOV_HDR_IA_NA].iov_len = 0;
488
489 if (na_mode == IA_MODE_NONE)
490 iov[IOV_HDR_IA_NA].iov_len = 0;
491
492 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
493 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
494 iov[IOV_RECONF_ACCEPT].iov_len = 0;
495
496 if (!(client_options & DHCPV6_CLIENT_FQDN))
497 iov[IOV_FQDN].iov_len = 0;
498
499 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
500 0, ALL_DHCPV6_RELAYS, ifindex};
501 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
502 .msg_iov = iov, .msg_iovlen = cnt};
503
504 sendmsg(sock, &msg, 0);
505 }
506
507
508 static int64_t dhcpv6_rand_delay(int64_t time)
509 {
510 int random;
511 odhcp6c_random(&random, sizeof(random));
512 return (time * ((int64_t)random % 1000LL)) / 10000LL;
513 }
514
515
516 int dhcpv6_request(enum dhcpv6_msg type)
517 {
518 uint8_t rc = 0;
519 uint64_t timeout = UINT32_MAX;
520 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
521
522 if (retx->delay) {
523 struct timespec ts = {0, 0};
524 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
525 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
526 }
527
528 if (type == DHCPV6_MSG_UNKNOWN)
529 timeout = t1;
530 else if (type == DHCPV6_MSG_RENEW)
531 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
532 else if (type == DHCPV6_MSG_REBIND)
533 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
534
535 if (timeout == 0)
536 return -1;
537
538 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
539 retx->name, (unsigned long long)timeout, retx->max_rc);
540
541 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
542
543 // Generate transaction ID
544 uint8_t trid[3] = {0, 0, 0};
545 if (type != DHCPV6_MSG_UNKNOWN)
546 odhcp6c_random(trid, sizeof(trid));
547 ssize_t len = -1;
548 int64_t rto = 0;
549
550 do {
551 if (rto == 0) {
552 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
553
554 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
555 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
556 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
557
558 rto = (retx->init_timeo * 1000 + delay);
559 }
560 else
561 rto = (2 * rto + dhcpv6_rand_delay(rto));
562
563 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
564 rto = retx->max_timeo * 1000 +
565 dhcpv6_rand_delay(retx->max_timeo * 1000);
566
567 // Calculate end for this round and elapsed time
568 uint64_t round_end = round_start + rto;
569 elapsed = round_start - start;
570
571 // Don't wait too long if timeout differs from infinite
572 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
573 round_end = timeout * 1000 + start;
574
575 // Built and send package
576 switch (type) {
577 case DHCPV6_MSG_UNKNOWN:
578 break;
579 default:
580 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
581 retx->name, (unsigned long long)elapsed, rc);
582 // Fall through
583 case DHCPV6_MSG_SOLICIT:
584 case DHCPV6_MSG_INFO_REQ:
585 dhcpv6_send(type, trid, elapsed / 10);
586 rc++;
587 }
588
589 // Receive rounds
590 for (; len < 0 && (round_start < round_end);
591 round_start = odhcp6c_get_milli_time()) {
592 uint8_t buf[1536];
593 union {
594 struct cmsghdr hdr;
595 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
596 } cmsg_buf;
597 struct iovec iov = {buf, sizeof(buf)};
598 struct sockaddr_in6 addr;
599 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
600 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
601 .msg_controllen = sizeof(cmsg_buf)};
602 struct in6_pktinfo *pktinfo = NULL;
603
604
605 // Check for pending signal
606 if (odhcp6c_signal_process())
607 return -1;
608
609 // Set timeout for receiving
610 uint64_t t = round_end - round_start;
611 struct timeval tv = {t / 1000, (t % 1000) * 1000};
612 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
613 &tv, sizeof(tv));
614
615 // Receive cycle
616 len = recvmsg(sock, &msg, 0);
617 if (len < 0)
618 continue;
619
620 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
621 ch = CMSG_NXTHDR(&msg, ch)) {
622 if (ch->cmsg_level == SOL_IPV6 &&
623 ch->cmsg_type == IPV6_PKTINFO) {
624 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
625 break;
626 }
627 }
628
629 if (pktinfo == NULL) {
630 len = -1;
631 continue;
632 }
633
634 if (!dhcpv6_response_is_valid(buf, len, trid,
635 type, &pktinfo->ipi6_addr)) {
636 len = -1;
637 continue;
638 }
639
640 uint8_t *opt = &buf[4];
641 uint8_t *opt_end = opt + len - 4;
642
643 round_start = odhcp6c_get_milli_time();
644 elapsed = round_start - start;
645 syslog(LOG_NOTICE, "Got a valid reply after "
646 "%llums", (unsigned long long)elapsed);
647
648 if (retx->handler_reply)
649 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
650
651 if (len > 0 && round_end - round_start > 1000)
652 round_end = 1000 + round_start;
653 }
654
655 // Allow
656 if (retx->handler_finish)
657 len = retx->handler_finish();
658 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
659 (!retx->max_rc || rc < retx->max_rc));
660 return len;
661 }
662
663 // Message validation checks according to RFC3315 chapter 15
664 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
665 const uint8_t transaction[3], enum dhcpv6_msg type,
666 const struct in6_addr *daddr)
667 {
668 const struct dhcpv6_header *rep = buf;
669 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
670 transaction, sizeof(rep->tr_id)))
671 return false; // Invalid reply
672
673 if (type == DHCPV6_MSG_SOLICIT) {
674 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
675 rep->msg_type != DHCPV6_MSG_REPLY)
676 return false;
677 } else if (type == DHCPV6_MSG_UNKNOWN) {
678 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
679 return false;
680 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
681 return false;
682 }
683
684 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
685 rcmsg = DHCPV6_MSG_UNKNOWN;
686 uint16_t otype, olen = UINT16_MAX;
687 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
688 ia_present = false, options_valid = true;
689
690 size_t client_id_len, server_id_len;
691 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
692 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
693
694 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
695 if (otype == DHCPV6_OPT_CLIENTID) {
696 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
697 &odata[-4], client_id, client_id_len);
698 } else if (otype == DHCPV6_OPT_SERVERID) {
699 if (server_id_len)
700 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
701 &odata[-4], server_id, server_id_len);
702 else
703 serverid_ok = true;
704 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
705 sizeof(struct dhcpv6_auth_reconfigure)) {
706 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
707 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
708 continue;
709
710 md5_ctx_t md5;
711 uint8_t serverhash[16], secretbytes[64];
712 uint32_t hash[4];
713 memcpy(serverhash, r->key, sizeof(serverhash));
714 memset(r->key, 0, sizeof(r->key));
715
716 memset(secretbytes, 0, sizeof(secretbytes));
717 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
718
719 for (size_t i = 0; i < sizeof(secretbytes); ++i)
720 secretbytes[i] ^= 0x36;
721
722 md5_begin(&md5);
723 md5_hash(secretbytes, sizeof(secretbytes), &md5);
724 md5_hash(buf, len, &md5);
725 md5_end(hash, &md5);
726
727 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
728 secretbytes[i] ^= 0x36;
729 secretbytes[i] ^= 0x5c;
730 }
731
732 md5_begin(&md5);
733 md5_hash(secretbytes, sizeof(secretbytes), &md5);
734 md5_hash(hash, 16, &md5);
735 md5_end(hash, &md5);
736
737 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
738 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
739 rcmsg = odata[0];
740 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
741 ia_present = true;
742 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
743 options_valid = false;
744 }
745 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
746 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
747 // Options are not allowed on global level
748 options_valid = false;
749 }
750 }
751
752 if (!options_valid || ((odata + olen) > end))
753 return false;
754
755 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
756 return false;
757
758 if (rep->msg_type == DHCPV6_MSG_RECONF) {
759 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
760 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
761 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
762 return false;
763 }
764
765 return clientid_ok && serverid_ok;
766 }
767
768
769 int dhcpv6_poll_reconfigure(void)
770 {
771 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
772 if (ret != -1)
773 ret = dhcpv6_request(ret);
774
775 return ret;
776 }
777
778
779 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
780 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
781 {
782 uint16_t otype, olen;
783 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
784 dhcpv6_for_each_option(opt, end, otype, olen, odata)
785 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
786 odata[0] == DHCPV6_MSG_RENEW ||
787 odata[0] == DHCPV6_MSG_INFO_REQ))
788 msg = odata[0];
789
790 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL, NULL);
791 return msg;
792 }
793
794
795 // Collect all advertised servers
796 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
797 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
798 {
799 uint16_t olen, otype;
800 uint8_t *odata, pref = 0;
801 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
802 DHCPV6_SOL_MAX_RT,
803 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
804 bool have_na = false;
805 int have_pd = 0;
806
807 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
808 if (orig == DHCPV6_MSG_SOLICIT &&
809 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
810 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
811 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
812 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
813 }
814
815 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
816 memcpy(cand.duid, odata, olen);
817 cand.duid_len = olen;
818 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
819 cand.preference >= 0) {
820 cand.preference = pref = odata[0];
821 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
822 cand.wants_reconfigure = true;
823 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
824 uint32_t sol_max_rt = ntohl_unaligned(odata);
825 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
826 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
827 cand.sol_max_rt = sol_max_rt;
828 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
829 uint32_t inf_max_rt = ntohl_unaligned(odata);
830 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
831 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
832 cand.inf_max_rt = inf_max_rt;
833 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix &&
834 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
835 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
836 uint8_t *oend = odata + olen, *d;
837 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
838 if (otype == DHCPV6_OPT_IA_PREFIX &&
839 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
840 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
841 have_pd = p->prefix;
842 }
843 }
844 } else if (otype == DHCPV6_OPT_IA_NA &&
845 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
846 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
847 uint8_t *oend = odata + olen, *d;
848 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
849 if (otype == DHCPV6_OPT_IA_ADDR &&
850 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
851 have_na = true;
852 }
853 }
854
855 if ((!have_na && na_mode == IA_MODE_FORCE) ||
856 (!have_pd && pd_mode == IA_MODE_FORCE)) {
857 /*
858 * RFC7083 states to process the SOL_MAX_RT and
859 * INF_MAX_RT options even if the DHCPv6 server
860 * did not propose any IA_NA and/or IA_PD
861 */
862 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
863 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
864 return -1;
865 }
866
867 if (na_mode != IA_MODE_NONE && !have_na) {
868 cand.has_noaddravail = true;
869 cand.preference -= 1000;
870 }
871
872 if (pd_mode != IA_MODE_NONE) {
873 if (have_pd)
874 cand.preference += 2000 + (128 - have_pd);
875 else
876 cand.preference -= 2000;
877 }
878
879 if (cand.duid_len > 0) {
880 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
881 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
882 dhcpv6_add_server_cand(&cand);
883 }
884
885 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
886 }
887
888
889 static int dhcpv6_commit_advert(void)
890 {
891 return dhcpv6_promote_server_cand();
892 }
893
894
895 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
896 const void *opt, const void *end, const struct sockaddr_in6 *from)
897 {
898 dhcpv6_handle_advert(orig, rc, opt, end, from);
899 if (dhcpv6_commit_advert() < 0)
900 return -1;
901
902 return dhcpv6_handle_reply(orig, rc, opt, end, from);
903 }
904
905
906 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
907 const void *opt, const void *end, const struct sockaddr_in6 *from)
908 {
909 uint8_t *odata;
910 uint16_t otype, olen;
911 uint32_t refresh = 86400;
912 int ret = 1;
913 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
914
915 odhcp6c_expire();
916
917 if (orig == DHCPV6_MSG_UNKNOWN) {
918 static time_t last_update = 0;
919 time_t now = odhcp6c_get_milli_time() / 1000;
920
921 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
922 last_update = now;
923
924 if (t1 != UINT32_MAX)
925 t1 -= elapsed;
926
927 if (t2 != UINT32_MAX)
928 t2 -= elapsed;
929
930 if (t3 != UINT32_MAX)
931 t3 -= elapsed;
932
933 if (t1 < 0)
934 t1 = 0;
935
936 if (t2 < 0)
937 t2 = 0;
938
939 if (t3 < 0)
940 t3 = 0;
941 }
942
943 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
944 // Delete NA and PD we have in the state from the Advert
945 odhcp6c_clear_state(STATE_IA_NA);
946 odhcp6c_clear_state(STATE_IA_PD);
947 }
948
949 if (opt) {
950 odhcp6c_clear_state(STATE_DNS);
951 odhcp6c_clear_state(STATE_SEARCH);
952 odhcp6c_clear_state(STATE_SNTP_IP);
953 odhcp6c_clear_state(STATE_NTP_IP);
954 odhcp6c_clear_state(STATE_NTP_FQDN);
955 odhcp6c_clear_state(STATE_SIP_IP);
956 odhcp6c_clear_state(STATE_SIP_FQDN);
957 odhcp6c_clear_state(STATE_AFTR_NAME);
958 odhcp6c_clear_state(STATE_CER);
959 odhcp6c_clear_state(STATE_S46_MAPT);
960 odhcp6c_clear_state(STATE_S46_MAPE);
961 odhcp6c_clear_state(STATE_S46_LW);
962 odhcp6c_clear_state(STATE_PASSTHRU);
963 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
964
965 // Parse and find all matching IAs
966 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
967 bool passthru = true;
968
969 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
970 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
971 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
972
973 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
974 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
975 continue;
976
977 // Test ID
978 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
979 continue;
980
981 uint16_t code = DHCPV6_Success;
982 uint16_t stype, slen;
983 uint8_t *sdata;
984 // Get and handle status code
985 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
986 stype, slen, sdata) {
987 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
988 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
989 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
990
991 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
992
993 if (code == DHCPV6_Success)
994 continue;
995
996 dhcpv6_handle_ia_status_code(orig, ia_hdr,
997 code, mdata, mlen, handled_status_codes, &ret);
998
999
1000 if (ret > 0)
1001 return ret;
1002 break;
1003 }
1004 }
1005
1006 if (code != DHCPV6_Success)
1007 continue;
1008
1009 dhcpv6_parse_ia(ia_hdr, odata + olen);
1010 passthru = false;
1011 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1012 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1013 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1014 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1015
1016 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1017 passthru = false;
1018 }
1019 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1020 if (olen % 16 == 0)
1021 odhcp6c_add_state(STATE_DNS, odata, olen);
1022 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
1023 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1024 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1025 if (olen % 16 == 0)
1026 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1027 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1028 uint16_t stype, slen;
1029 uint8_t *sdata;
1030 // Test status and bail if error
1031 dhcpv6_for_each_option(odata, odata + olen,
1032 stype, slen, sdata) {
1033 if (slen == 16 && (stype == NTP_MC_ADDR ||
1034 stype == NTP_SRV_ADDR))
1035 odhcp6c_add_state(STATE_NTP_IP,
1036 sdata, slen);
1037 else if (slen > 0 && stype == NTP_SRV_FQDN)
1038 odhcp6c_add_state(STATE_NTP_FQDN,
1039 sdata, slen);
1040 }
1041 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1042 if (olen == 16)
1043 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1044 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
1045 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1046 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1047 refresh = ntohl_unaligned(odata);
1048 passthru = false;
1049 } else if (otype == DHCPV6_OPT_AUTH) {
1050 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1051 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1052 if (r->protocol == 3 && r->algorithm == 1 &&
1053 r->reconf_type == 1)
1054 memcpy(reconf_key, r->key, sizeof(r->key));
1055 }
1056 passthru = false;
1057 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1058 size_t cur_len;
1059 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1060 if (cur_len == 0)
1061 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1062 passthru = false;
1063 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1064 uint32_t sol_max_rt = ntohl_unaligned(odata);
1065 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1066 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1067 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1068 passthru = false;
1069 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1070 uint32_t inf_max_rt = ntohl_unaligned(odata);
1071 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1072 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1073 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1074 passthru = false;
1075 #ifdef EXT_CER_ID
1076 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1077 sizeof(struct dhcpv6_cer_id)) {
1078 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1079 struct in6_addr any = IN6ADDR_ANY_INIT;
1080 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1081 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1082 passthru = false;
1083 #endif
1084 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1085 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1086 passthru = false;
1087 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1088 size_t mape_len;
1089 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1090 if (mape_len == 0)
1091 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1092 passthru = false;
1093 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1094 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1095 passthru = false;
1096 } else if (otype == DHCPV6_OPT_CLIENTID ||
1097 otype == DHCPV6_OPT_SERVERID ||
1098 otype == DHCPV6_OPT_IA_TA ||
1099 otype == DHCPV6_OPT_PREF ||
1100 otype == DHCPV6_OPT_UNICAST ||
1101 otype == DHCPV6_OPT_FQDN ||
1102 otype == DHCPV6_OPT_RECONF_ACCEPT) {
1103 passthru = false;
1104 } else {
1105 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1106 }
1107
1108 if (passthru)
1109 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1110 }
1111 }
1112
1113 if (orig != DHCPV6_MSG_INFO_REQ) {
1114 // Update refresh timers if no fatal status code was received
1115 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1116 switch (orig) {
1117 case DHCPV6_MSG_RENEW:
1118 // Send further renews if T1 is not set
1119 if (!t1)
1120 ret = -1;
1121 break;
1122 case DHCPV6_MSG_REBIND:
1123 // Send further rebinds if T1 and T2 is not set
1124 if (!t1 && !t2)
1125 ret = -1;
1126 break;
1127
1128 case DHCPV6_MSG_REQUEST:
1129 // All server candidates can be cleared if not yet bound
1130 if (!odhcp6c_is_bound())
1131 dhcpv6_clear_all_server_cand();
1132
1133 default :
1134 break;
1135 }
1136
1137 if (orig == DHCPV6_MSG_REBIND || orig == DHCPV6_MSG_REQUEST) {
1138 odhcp6c_clear_state(STATE_SERVER_ADDR);
1139 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1140 }
1141 }
1142 }
1143 else if (ret > 0) {
1144 // All server candidates can be cleared if not yet bound
1145 if (!odhcp6c_is_bound())
1146 dhcpv6_clear_all_server_cand();
1147
1148 t1 = refresh;
1149 }
1150
1151 return ret;
1152 }
1153
1154
1155 static int dhcpv6_parse_ia(void *opt, void *end)
1156 {
1157 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1158 int parsed_ia = 0;
1159 uint32_t t1, t2;
1160 uint16_t otype, olen;
1161 uint8_t *odata;
1162
1163 t1 = ntohl(ia_hdr->t1);
1164 t2 = ntohl(ia_hdr->t2);
1165
1166 if (t1 > t2)
1167 return 0;
1168
1169 // Update address IA
1170 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1171 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1172 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1173
1174 entry.iaid = ia_hdr->iaid;
1175
1176 if (otype == DHCPV6_OPT_IA_PREFIX) {
1177 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1178 if (olen + 4U < sizeof(*prefix))
1179 continue;
1180
1181 entry.valid = ntohl(prefix->valid);
1182 entry.preferred = ntohl(prefix->preferred);
1183
1184 if (entry.preferred > entry.valid)
1185 continue;
1186
1187 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1188 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1189 if (entry.t1 > entry.t2)
1190 entry.t1 = entry.t2;
1191
1192 entry.length = prefix->prefix;
1193 entry.target = prefix->addr;
1194 uint16_t stype, slen;
1195 uint8_t *sdata;
1196
1197 // Parse PD-exclude
1198 bool ok = true;
1199 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1200 odata + olen, stype, slen, sdata) {
1201 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1202 continue;
1203
1204 uint8_t elen = sdata[0];
1205 if (elen > 64)
1206 elen = 64;
1207
1208 if (entry.length < 32 || elen <= entry.length) {
1209 ok = false;
1210 continue;
1211 }
1212
1213
1214 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1215 if (slen <= bytes) {
1216 ok = false;
1217 continue;
1218 }
1219
1220 uint32_t exclude = 0;
1221 do {
1222 exclude = exclude << 8 | sdata[bytes];
1223 } while (--bytes);
1224
1225 exclude >>= 8 - ((elen - entry.length) % 8);
1226 exclude <<= 64 - elen;
1227
1228 // Abusing router & priority fields for exclusion
1229 entry.router = entry.target;
1230 entry.router.s6_addr32[1] |= htonl(exclude);
1231 entry.priority = elen;
1232 }
1233
1234 if (ok) {
1235 odhcp6c_update_entry(STATE_IA_PD, &entry, 0, false);
1236 parsed_ia++;
1237 }
1238
1239 entry.priority = 0;
1240 memset(&entry.router, 0, sizeof(entry.router));
1241 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1242 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1243 if (olen + 4U < sizeof(*addr))
1244 continue;
1245
1246 entry.preferred = ntohl(addr->preferred);
1247 entry.valid = ntohl(addr->valid);
1248
1249 if (entry.preferred > entry.valid)
1250 continue;
1251
1252 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1253 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1254 if (entry.t1 > entry.t2)
1255 entry.t1 = entry.t2;
1256
1257 entry.length = 128;
1258 entry.target = addr->addr;
1259
1260 odhcp6c_update_entry(STATE_IA_NA, &entry, 0, false);
1261 parsed_ia++;
1262 }
1263 }
1264 return parsed_ia;
1265 }
1266
1267
1268 static int dhcpv6_calc_refresh_timers(void)
1269 {
1270 struct odhcp6c_entry *e;
1271 size_t ia_na_entries, ia_pd_entries, i;
1272 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1273
1274 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1275 ia_na_entries /= sizeof(*e);
1276 for (i = 0; i < ia_na_entries; i++) {
1277 if (e[i].t1 < l_t1)
1278 l_t1 = e[i].t1;
1279
1280 if (e[i].t2 < l_t2)
1281 l_t2 = e[i].t2;
1282
1283 if (e[i].valid > l_t3)
1284 l_t3 = e[i].valid;
1285 }
1286
1287 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1288 ia_pd_entries /= sizeof(*e);
1289 for (i = 0; i < ia_pd_entries; i++) {
1290 if (e[i].t1 < l_t1)
1291 l_t1 = e[i].t1;
1292
1293 if (e[i].t2 < l_t2)
1294 l_t2 = e[i].t2;
1295
1296 if (e[i].valid > l_t3)
1297 l_t3 = e[i].valid;
1298 }
1299
1300 if (ia_pd_entries || ia_na_entries) {
1301 t1 = l_t1;
1302 t2 = l_t2;
1303 t3 = l_t3;
1304 } else {
1305 t1 = 600;
1306 }
1307
1308 return (int)(ia_pd_entries + ia_na_entries);
1309 }
1310
1311
1312 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1313 const void *status_msg, int len)
1314 {
1315 const char *src = status_msg;
1316 char buf[len + 3];
1317 char *dst = buf;
1318
1319 if (len) {
1320 *dst++ = '(';
1321 while (len--) {
1322 *dst = isprint((unsigned char)*src) ? *src : '?';
1323 src++;
1324 dst++;
1325 }
1326 *dst++ = ')';
1327 }
1328 *dst = 0;
1329
1330 syslog(LOG_WARNING, "Server returned %s status %i %s",
1331 scope, code, buf);
1332 }
1333
1334
1335 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1336 const uint16_t code, const void *status_msg, const int len,
1337 int *ret)
1338 {
1339 dhcpv6_log_status_code(code, "message", status_msg, len);
1340
1341 switch (code) {
1342 case DHCPV6_UnspecFail:
1343 // Generic failure
1344 *ret = 0;
1345 break;
1346
1347 case DHCPV6_UseMulticast:
1348 // TODO handle multicast status code
1349 break;
1350
1351 case DHCPV6_NoAddrsAvail:
1352 case DHCPV6_NoPrefixAvail:
1353 if (orig == DHCPV6_MSG_REQUEST)
1354 *ret = 0; // Failure
1355 break;
1356
1357 default:
1358 break;
1359 }
1360 }
1361
1362
1363 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1364 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1365 const void *status_msg, const int len,
1366 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1367 {
1368 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1369 "IA_NA" : "IA_PD", status_msg, len);
1370
1371 switch (code) {
1372 case DHCPV6_NoBinding:
1373 switch (orig) {
1374 case DHCPV6_MSG_RENEW:
1375 case DHCPV6_MSG_REBIND:
1376 if ((*ret > 0) && !handled_status_codes[code])
1377 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1378 break;
1379
1380 default:
1381 break;
1382 }
1383 break;
1384
1385 default:
1386 *ret = 0;
1387 break;
1388 }
1389 }
1390
1391 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1392 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1393 {
1394 size_t cand_len, i;
1395 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1396
1397 // Remove identical duid server candidate
1398 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1399 if (cand->duid_len == c[i].duid_len &&
1400 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1401 free(c[i].ia_na);
1402 free(c[i].ia_pd);
1403 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1404 break;
1405 }
1406 }
1407
1408 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1409 i < cand_len / sizeof(*c); ++i) {
1410 if (c[i].preference < cand->preference)
1411 break;
1412 }
1413
1414 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1415 free(cand->ia_na);
1416 free(cand->ia_pd);
1417 }
1418 }
1419
1420 static void dhcpv6_clear_all_server_cand(void)
1421 {
1422 size_t cand_len, i;
1423 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1424
1425 // Server candidates need deep delete for IA_NA/IA_PD
1426 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1427 free(c[i].ia_na);
1428 free(c[i].ia_pd);
1429 }
1430 odhcp6c_clear_state(STATE_SERVER_CAND);
1431 }
1432
1433 int dhcpv6_promote_server_cand(void)
1434 {
1435 size_t cand_len;
1436 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1437 uint16_t hdr[2];
1438 int ret = DHCPV6_STATELESS;
1439
1440 // Clear lingering candidate state info
1441 odhcp6c_clear_state(STATE_SERVER_ID);
1442 odhcp6c_clear_state(STATE_IA_NA);
1443 odhcp6c_clear_state(STATE_IA_PD);
1444
1445 if (!cand_len)
1446 return -1;
1447
1448 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1449 na_mode = IA_MODE_NONE;
1450
1451 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1452 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1453
1454 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1455 }
1456
1457 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1458 hdr[1] = htons(cand->duid_len);
1459 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1460 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1461 accept_reconfig = cand->wants_reconfigure;
1462 if (cand->ia_na_len) {
1463 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1464 free(cand->ia_na);
1465 if (na_mode != IA_MODE_NONE)
1466 ret = DHCPV6_STATEFUL;
1467 }
1468 if (cand->ia_pd_len) {
1469 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1470 free(cand->ia_pd);
1471 if (request_prefix)
1472 ret = DHCPV6_STATEFUL;
1473 }
1474
1475 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1476 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1477
1478 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1479
1480 return ret;
1481 }
Openwrt DHCPv6 Client