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CMakeLists: don't enable libubox md5 implementation by default
[project/odhcp6c.git] / src / dhcpv6.c
1 /**
2 * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
3 * Copyright (C) 2017 Hans Dedecker <dedeckeh@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License v2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16 #include <time.h>
17 #include <fcntl.h>
18 #include <errno.h>
19 #include <inttypes.h>
20 #include <stdlib.h>
21 #include <signal.h>
22 #include <limits.h>
23 #include <resolv.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <syslog.h>
27 #include <stdbool.h>
28 #include <ctype.h>
29 #include <sys/time.h>
30 #include <sys/ioctl.h>
31 #include <sys/socket.h>
32 #include <arpa/inet.h>
33 #include <netinet/in.h>
34
35 #include <net/if.h>
36 #include <net/ethernet.h>
37
38 #include "odhcp6c.h"
39 #ifdef USE_LIBUBOX
40 #include <libubox/md5.h>
41 #else
42 #include "md5.h"
43 #endif
44
45
46 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
47 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
48 #define DHCPV6_CLIENT_PORT 546
49 #define DHCPV6_SERVER_PORT 547
50 #define DHCPV6_DUID_LLADDR 3
51 #define DHCPV6_REQ_DELAY 1
52
53 #define DHCPV6_SOL_MAX_RT_MIN 60
54 #define DHCPV6_SOL_MAX_RT_MAX 86400
55 #define DHCPV6_INF_MAX_RT_MIN 60
56 #define DHCPV6_INF_MAX_RT_MAX 86400
57
58 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
59 const uint8_t transaction[3], enum dhcpv6_msg type,
60 const struct in6_addr *daddr);
61
62 static int dhcpv6_parse_ia(void *opt, void *end);
63
64 static int dhcpv6_calc_refresh_timers(void);
65 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
66 const uint16_t code, const void *status_msg, const int len,
67 int *ret);
68 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
69 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
70 const void *status_msg, const int len,
71 bool handled_status_codes[_DHCPV6_Status_Max],
72 int *ret);
73 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
74 static void dhcpv6_clear_all_server_cand(void);
75
76 static reply_handler dhcpv6_handle_reply;
77 static reply_handler dhcpv6_handle_advert;
78 static reply_handler dhcpv6_handle_rebind_reply;
79 static reply_handler dhcpv6_handle_reconfigure;
80 static int dhcpv6_commit_advert(void);
81
82
83
84 // RFC 3315 - 5.5 Timeout and Delay values
85 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
86 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
87 dhcpv6_handle_reconfigure, NULL},
88 [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
89 dhcpv6_handle_advert, dhcpv6_commit_advert},
90 [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
91 dhcpv6_handle_reply, NULL},
92 [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
93 dhcpv6_handle_reply, NULL},
94 [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
95 dhcpv6_handle_rebind_reply, NULL},
96 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
97 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
98 [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
99 dhcpv6_handle_reply, NULL},
100 };
101
102
103 // Sockets
104 static int sock = -1;
105 static int ifindex = -1;
106 static int64_t t1 = 0, t2 = 0, t3 = 0;
107
108 // IA states
109 static int request_prefix = -1;
110 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
111 static bool accept_reconfig = false;
112 // Server unicast address
113 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
114
115 // Reconfigure key
116 static uint8_t reconf_key[16];
117
118 // client options
119 static unsigned int client_options = 0;
120
121
122 static uint32_t ntohl_unaligned(const uint8_t *data)
123 {
124 uint32_t buf;
125
126 memcpy(&buf, data, sizeof(buf));
127 return ntohl(buf);
128 }
129
130 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
131 {
132 client_options = options;
133 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
134
135 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
136 if (sock < 0)
137 return -1;
138
139 // Detect interface
140 struct ifreq ifr;
141 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
142 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
143 return -1;
144 ifindex = ifr.ifr_ifindex;
145
146 // Create client DUID
147 size_t client_id_len;
148 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
149 if (client_id_len == 0) {
150 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
151 DHCPV6_DUID_LLADDR, 0, 1};
152
153 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
154 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
155
156 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
157 struct ifreq ifs[100], *ifp, *ifend;
158 struct ifconf ifc;
159 ifc.ifc_req = ifs;
160 ifc.ifc_len = sizeof(ifs);
161
162 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
163 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
164 // If our interface doesn't have an address...
165 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
166 for (ifp = ifc.ifc_req; ifp < ifend &&
167 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
168 memcpy(ifr.ifr_name, ifp->ifr_name,
169 sizeof(ifr.ifr_name));
170 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
171 continue;
172
173 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
174 ETHER_ADDR_LEN);
175 }
176 }
177
178 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
179 }
180
181 // Create ORO
182 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
183 uint16_t oro[] = {
184 htons(DHCPV6_OPT_SIP_SERVER_D),
185 htons(DHCPV6_OPT_SIP_SERVER_A),
186 htons(DHCPV6_OPT_DNS_SERVERS),
187 htons(DHCPV6_OPT_DNS_DOMAIN),
188 htons(DHCPV6_OPT_UNICAST),
189 htons(DHCPV6_OPT_SNTP_SERVERS),
190 htons(DHCPV6_OPT_NTP_SERVER),
191 htons(DHCPV6_OPT_AFTR_NAME),
192 htons(DHCPV6_OPT_PD_EXCLUDE),
193 htons(DHCPV6_OPT_SOL_MAX_RT),
194 htons(DHCPV6_OPT_INF_MAX_RT),
195 #ifdef EXT_CER_ID
196 htons(DHCPV6_OPT_CER_ID),
197 #endif
198 htons(DHCPV6_OPT_S46_CONT_MAPE),
199 htons(DHCPV6_OPT_S46_CONT_MAPT),
200 htons(DHCPV6_OPT_S46_CONT_LW),
201 };
202 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
203 }
204
205 // Configure IPv6-options
206 int val = 1;
207 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
208 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
209 setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
210 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
211
212 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
213 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
214 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
215 return -1;
216
217 return 0;
218 }
219
220 enum {
221 IOV_HDR=0,
222 IOV_ORO,
223 IOV_ORO_REFRESH,
224 IOV_CL_ID,
225 IOV_SRV_ID,
226 IOV_VENDOR_CLASS_HDR,
227 IOV_VENDOR_CLASS,
228 IOV_USER_CLASS_HDR,
229 IOV_USER_CLASS,
230 IOV_RECONF_ACCEPT,
231 IOV_FQDN,
232 IOV_HDR_IA_NA,
233 IOV_IA_NA,
234 IOV_IA_PD,
235 IOV_TOTAL
236 };
237
238 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
239 {
240 int mode = DHCPV6_UNKNOWN;
241
242 na_mode = na;
243 pd_mode = pd;
244
245 if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE)
246 mode = DHCPV6_STATELESS;
247 else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE)
248 mode = DHCPV6_STATEFUL;
249
250 return mode;
251 }
252
253 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
254 {
255 // Build FQDN
256 char fqdn_buf[256];
257 gethostname(fqdn_buf, sizeof(fqdn_buf));
258 struct {
259 uint16_t type;
260 uint16_t len;
261 uint8_t flags;
262 uint8_t data[256];
263 } fqdn;
264 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
265 sizeof(fqdn.data), NULL, NULL);
266 fqdn.type = htons(DHCPV6_OPT_FQDN);
267 fqdn.len = htons(fqdn_len - 4);
268 fqdn.flags = 0;
269
270
271 // Build Client ID
272 size_t cl_id_len;
273 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
274
275 // Get Server ID
276 size_t srv_id_len;
277 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
278
279 // Build IA_PDs
280 size_t ia_pd_entries = 0, ia_pd_len = 0;
281 uint8_t *ia_pd;
282
283 if (type == DHCPV6_MSG_SOLICIT) {
284 odhcp6c_clear_state(STATE_IA_PD);
285 size_t n_prefixes;
286 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
287 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
288
289 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
290
291 for (size_t i = 0; i < n_prefixes; i++) {
292 struct dhcpv6_ia_hdr hdr_ia_pd = {
293 htons(DHCPV6_OPT_IA_PD),
294 htons(sizeof(hdr_ia_pd) - 4 +
295 sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length),
296 request_prefixes[i].iaid, 0, 0
297 };
298 struct dhcpv6_ia_prefix pref = {
299 .type = htons(DHCPV6_OPT_IA_PREFIX),
300 .len = htons(sizeof(pref) - 4),
301 .prefix = request_prefixes[i].length
302 };
303 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
304 ia_pd_len += sizeof(hdr_ia_pd);
305 if (request_prefixes[i].length) {
306 memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
307 ia_pd_len += sizeof(pref);
308 }
309 }
310 } else {
311 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
312 ia_pd_entries /= sizeof(*e);
313
314 // we're too lazy to count our distinct IAIDs,
315 // so just allocate maximally needed space
316 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
317 sizeof(struct dhcpv6_ia_hdr)));
318
319 for (size_t i = 0; i < ia_pd_entries; ++i) {
320 uint32_t iaid = e[i].iaid;
321
322 // check if this is an unprocessed IAID and skip if not.
323 int new_iaid = 1;
324 for (int j = i-1; j >= 0; j--) {
325 if (e[j].iaid == iaid) {
326 new_iaid = 0;
327 break;
328 }
329 }
330
331 if (!new_iaid)
332 continue;
333
334 // construct header
335 struct dhcpv6_ia_hdr hdr_ia_pd = {
336 htons(DHCPV6_OPT_IA_PD),
337 htons(sizeof(hdr_ia_pd) - 4),
338 iaid, 0, 0
339 };
340
341 memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
342 struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
343 ia_pd_len += sizeof(hdr_ia_pd);
344
345 for (size_t j = i; j < ia_pd_entries; j++) {
346 if (e[j].iaid != iaid)
347 continue;
348
349 uint8_t ex_len = 0;
350 if (e[j].priority > 0)
351 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
352
353 struct dhcpv6_ia_prefix p = {
354 .type = htons(DHCPV6_OPT_IA_PREFIX),
355 .len = htons(sizeof(p) - 4U + ex_len),
356 .prefix = e[j].length,
357 .addr = e[j].target
358 };
359
360 if (type == DHCPV6_MSG_REQUEST) {
361 p.preferred = htonl(e[j].preferred);
362 p.valid = htonl(e[j].valid);
363 }
364
365 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
366 ia_pd_len += sizeof(p);
367
368 if (ex_len) {
369 ia_pd[ia_pd_len++] = 0;
370 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
371 ia_pd[ia_pd_len++] = 0;
372 ia_pd[ia_pd_len++] = ex_len - 4;
373 ia_pd[ia_pd_len++] = e[j].priority;
374
375 uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
376 excl >>= (64 - e[j].priority);
377 excl <<= 8 - ((e[j].priority - e[j].length) % 8);
378
379 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
380 ia_pd[ia_pd_len + i] = excl & 0xff;
381 ia_pd_len += ex_len - 5;
382 }
383
384 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
385 }
386 }
387 }
388
389 if (ia_pd_entries > 0)
390 request_prefix = 1;
391
392 // Build IA_NAs
393 size_t ia_na_entries, ia_na_len = 0;
394 void *ia_na = NULL;
395 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
396 ia_na_entries /= sizeof(*e);
397
398 struct dhcpv6_ia_hdr hdr_ia_na = {
399 htons(DHCPV6_OPT_IA_NA),
400 htons(sizeof(hdr_ia_na) - 4),
401 htonl(1), 0, 0
402 };
403
404 struct dhcpv6_ia_addr pa[ia_na_entries];
405 for (size_t i = 0; i < ia_na_entries; ++i) {
406 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
407 pa[i].len = htons(sizeof(pa[i]) - 4U);
408 pa[i].addr = e[i].target;
409
410 if (type == DHCPV6_MSG_REQUEST) {
411 pa[i].preferred = htonl(e[i].preferred);
412 pa[i].valid = htonl(e[i].valid);
413 } else {
414 pa[i].preferred = 0;
415 pa[i].valid = 0;
416 }
417 }
418
419 ia_na = pa;
420 ia_na_len = sizeof(pa);
421 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
422
423 // Reconfigure Accept
424 struct {
425 uint16_t type;
426 uint16_t length;
427 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
428
429 // Request Information Refresh
430 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
431
432 // Build vendor-class option
433 size_t vendor_class_len, user_class_len;
434 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
435 void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
436
437 struct {
438 uint16_t type;
439 uint16_t length;
440 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
441
442 struct {
443 uint16_t type;
444 uint16_t length;
445 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
446
447 // Prepare Header
448 size_t oro_len;
449 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
450 struct {
451 uint8_t type;
452 uint8_t trid[3];
453 uint16_t elapsed_type;
454 uint16_t elapsed_len;
455 uint16_t elapsed_value;
456 uint16_t oro_type;
457 uint16_t oro_len;
458 } hdr = {
459 type, {trid[0], trid[1], trid[2]},
460 htons(DHCPV6_OPT_ELAPSED), htons(2),
461 htons((ecs > 0xffff) ? 0xffff : ecs),
462 htons(DHCPV6_OPT_ORO), htons(oro_len),
463 };
464
465 struct iovec iov[IOV_TOTAL] = {
466 [IOV_HDR] = {&hdr, sizeof(hdr)},
467 [IOV_ORO] = {oro, oro_len},
468 [IOV_ORO_REFRESH] = {&oro_refresh, 0},
469 [IOV_CL_ID] = {cl_id, cl_id_len},
470 [IOV_SRV_ID] = {srv_id, srv_id_len},
471 [IOV_VENDOR_CLASS_HDR] = {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
472 [IOV_VENDOR_CLASS] = {vendor_class, vendor_class_len},
473 [IOV_USER_CLASS_HDR] = {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
474 [IOV_USER_CLASS] = {user_class, user_class_len},
475 [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)},
476 [IOV_FQDN] = {&fqdn, fqdn_len},
477 [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)},
478 [IOV_IA_NA] = {ia_na, ia_na_len},
479 [IOV_IA_PD] = {ia_pd, ia_pd_len},
480 };
481
482 size_t cnt = IOV_TOTAL;
483 if (type == DHCPV6_MSG_INFO_REQ) {
484 cnt = 9;
485 iov[IOV_ORO_REFRESH].iov_len = sizeof(oro_refresh);
486 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
487 } else if (!request_prefix) {
488 cnt = 13;
489 }
490
491 // Disable IAs if not used
492 if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0)
493 iov[IOV_HDR_IA_NA].iov_len = 0;
494
495 if (na_mode == IA_MODE_NONE)
496 iov[IOV_HDR_IA_NA].iov_len = 0;
497
498 if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) ||
499 !(client_options & DHCPV6_ACCEPT_RECONFIGURE))
500 iov[IOV_RECONF_ACCEPT].iov_len = 0;
501
502 if (!(client_options & DHCPV6_CLIENT_FQDN))
503 iov[IOV_FQDN].iov_len = 0;
504
505 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
506 0, ALL_DHCPV6_RELAYS, ifindex};
507 struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv),
508 .msg_iov = iov, .msg_iovlen = cnt};
509
510 switch (type) {
511 case DHCPV6_MSG_REQUEST:
512 case DHCPV6_MSG_RENEW:
513 case DHCPV6_MSG_RELEASE:
514 case DHCPV6_MSG_DECLINE:
515 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
516 odhcp6c_addr_in_scope(&server_addr)) {
517 srv.sin6_addr = server_addr;
518 if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
519 srv.sin6_scope_id = 0;
520 }
521 break;
522 default:
523 break;
524 }
525
526 if (sendmsg(sock, &msg, 0) < 0) {
527 char in6_str[INET6_ADDRSTRLEN];
528
529 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
530 inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
531 in6_str, sizeof(in6_str)), strerror(errno));
532 }
533 }
534
535
536 static int64_t dhcpv6_rand_delay(int64_t time)
537 {
538 int random;
539 odhcp6c_random(&random, sizeof(random));
540 return (time * ((int64_t)random % 1000LL)) / 10000LL;
541 }
542
543
544 int dhcpv6_request(enum dhcpv6_msg type)
545 {
546 uint8_t rc = 0;
547 uint64_t timeout = UINT32_MAX;
548 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
549
550 if (retx->delay) {
551 struct timespec ts = {0, 0};
552 ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000;
553 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
554 }
555
556 if (type == DHCPV6_MSG_UNKNOWN)
557 timeout = t1;
558 else if (type == DHCPV6_MSG_RENEW)
559 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
560 else if (type == DHCPV6_MSG_REBIND)
561 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
562
563 if (timeout == 0)
564 return -1;
565
566 syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)",
567 retx->name, timeout, retx->max_rc);
568
569 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
570
571 // Generate transaction ID
572 uint8_t trid[3] = {0, 0, 0};
573 if (type != DHCPV6_MSG_UNKNOWN)
574 odhcp6c_random(trid, sizeof(trid));
575 ssize_t len = -1;
576 int64_t rto = 0;
577
578 do {
579 if (rto == 0) {
580 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
581
582 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
583 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
584 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
585
586 rto = (retx->init_timeo * 1000 + delay);
587 }
588 else
589 rto = (2 * rto + dhcpv6_rand_delay(rto));
590
591 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
592 rto = retx->max_timeo * 1000 +
593 dhcpv6_rand_delay(retx->max_timeo * 1000);
594
595 // Calculate end for this round and elapsed time
596 uint64_t round_end = round_start + rto;
597 elapsed = round_start - start;
598
599 // Don't wait too long if timeout differs from infinite
600 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
601 round_end = timeout * 1000 + start;
602
603 // Built and send package
604 switch (type) {
605 case DHCPV6_MSG_UNKNOWN:
606 break;
607 default:
608 syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)",
609 retx->name, elapsed, rc);
610 // Fall through
611 case DHCPV6_MSG_SOLICIT:
612 case DHCPV6_MSG_INFO_REQ:
613 dhcpv6_send(type, trid, elapsed / 10);
614 rc++;
615 }
616
617 // Receive rounds
618 for (; len < 0 && (round_start < round_end);
619 round_start = odhcp6c_get_milli_time()) {
620 uint8_t buf[1536];
621 union {
622 struct cmsghdr hdr;
623 uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
624 } cmsg_buf;
625 struct iovec iov = {buf, sizeof(buf)};
626 struct sockaddr_in6 addr;
627 struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr),
628 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf,
629 .msg_controllen = sizeof(cmsg_buf)};
630 struct in6_pktinfo *pktinfo = NULL;
631
632
633 // Check for pending signal
634 if (odhcp6c_signal_process())
635 return -1;
636
637 // Set timeout for receiving
638 uint64_t t = round_end - round_start;
639 struct timeval tv = {t / 1000, (t % 1000) * 1000};
640 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
641 &tv, sizeof(tv));
642
643 // Receive cycle
644 len = recvmsg(sock, &msg, 0);
645 if (len < 0)
646 continue;
647
648 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
649 ch = CMSG_NXTHDR(&msg, ch)) {
650 if (ch->cmsg_level == SOL_IPV6 &&
651 ch->cmsg_type == IPV6_PKTINFO) {
652 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
653 break;
654 }
655 }
656
657 if (pktinfo == NULL) {
658 len = -1;
659 continue;
660 }
661
662 if (!dhcpv6_response_is_valid(buf, len, trid,
663 type, &pktinfo->ipi6_addr)) {
664 len = -1;
665 continue;
666 }
667
668 uint8_t *opt = &buf[4];
669 uint8_t *opt_end = opt + len - 4;
670
671 round_start = odhcp6c_get_milli_time();
672 elapsed = round_start - start;
673 syslog(LOG_NOTICE, "Got a valid reply after %"PRIu64"ms",
674 elapsed);
675
676 if (retx->handler_reply)
677 len = retx->handler_reply(type, rc, opt, opt_end, &addr);
678
679 if (len > 0 && round_end - round_start > 1000)
680 round_end = 1000 + round_start;
681 }
682
683 // Allow
684 if (retx->handler_finish)
685 len = retx->handler_finish();
686 } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) &&
687 (!retx->max_rc || rc < retx->max_rc));
688 return len;
689 }
690
691 // Message validation checks according to RFC3315 chapter 15
692 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
693 const uint8_t transaction[3], enum dhcpv6_msg type,
694 const struct in6_addr *daddr)
695 {
696 const struct dhcpv6_header *rep = buf;
697 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
698 transaction, sizeof(rep->tr_id)))
699 return false; // Invalid reply
700
701 if (type == DHCPV6_MSG_SOLICIT) {
702 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
703 rep->msg_type != DHCPV6_MSG_REPLY)
704 return false;
705 } else if (type == DHCPV6_MSG_UNKNOWN) {
706 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
707 return false;
708 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
709 return false;
710 }
711
712 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
713 rcmsg = DHCPV6_MSG_UNKNOWN;
714 uint16_t otype, olen = UINT16_MAX;
715 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
716 ia_present = false, options_valid = true;
717
718 size_t client_id_len, server_id_len;
719 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
720 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
721
722 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
723 if (otype == DHCPV6_OPT_CLIENTID) {
724 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
725 &odata[-4], client_id, client_id_len);
726 } else if (otype == DHCPV6_OPT_SERVERID) {
727 if (server_id_len)
728 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
729 &odata[-4], server_id, server_id_len);
730 else
731 serverid_ok = true;
732 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
733 sizeof(struct dhcpv6_auth_reconfigure)) {
734 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
735 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
736 continue;
737
738 md5_ctx_t md5;
739 uint8_t serverhash[16], secretbytes[64];
740 uint32_t hash[4];
741 memcpy(serverhash, r->key, sizeof(serverhash));
742 memset(r->key, 0, sizeof(r->key));
743
744 memset(secretbytes, 0, sizeof(secretbytes));
745 memcpy(secretbytes, reconf_key, sizeof(reconf_key));
746
747 for (size_t i = 0; i < sizeof(secretbytes); ++i)
748 secretbytes[i] ^= 0x36;
749
750 md5_begin(&md5);
751 md5_hash(secretbytes, sizeof(secretbytes), &md5);
752 md5_hash(buf, len, &md5);
753 md5_end(hash, &md5);
754
755 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
756 secretbytes[i] ^= 0x36;
757 secretbytes[i] ^= 0x5c;
758 }
759
760 md5_begin(&md5);
761 md5_hash(secretbytes, sizeof(secretbytes), &md5);
762 md5_hash(hash, 16, &md5);
763 md5_end(hash, &md5);
764
765 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
766 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
767 rcmsg = odata[0];
768 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
769 ia_present = true;
770 if (olen < -4 + sizeof(struct dhcpv6_ia_hdr))
771 options_valid = false;
772 }
773 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
774 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
775 // Options are not allowed on global level
776 options_valid = false;
777 }
778 }
779
780 if (!options_valid || ((odata + olen) > end))
781 return false;
782
783 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
784 return false;
785
786 if (rep->msg_type == DHCPV6_MSG_RECONF) {
787 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
788 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
789 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
790 return false;
791 }
792
793 return clientid_ok && serverid_ok;
794 }
795
796
797 int dhcpv6_poll_reconfigure(void)
798 {
799 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
800 if (ret != -1)
801 ret = dhcpv6_request(ret);
802
803 return ret;
804 }
805
806
807 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
808 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
809 {
810 uint16_t otype, olen;
811 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
812 dhcpv6_for_each_option(opt, end, otype, olen, odata)
813 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
814 odata[0] == DHCPV6_MSG_RENEW ||
815 odata[0] == DHCPV6_MSG_INFO_REQ))
816 msg = odata[0];
817
818 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL, NULL);
819 return msg;
820 }
821
822
823 // Collect all advertised servers
824 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
825 const void *opt, const void *end, _unused const struct sockaddr_in6 *from)
826 {
827 uint16_t olen, otype;
828 uint8_t *odata, pref = 0;
829 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
830 IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT,
831 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
832 bool have_na = false;
833 int have_pd = 0;
834
835 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
836 if (orig == DHCPV6_MSG_SOLICIT &&
837 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
838 olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
839 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
840 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
841 }
842
843 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
844 memcpy(cand.duid, odata, olen);
845 cand.duid_len = olen;
846 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
847 cand.preference >= 0) {
848 cand.preference = pref = odata[0];
849 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
850 cand.server_addr = *(struct in6_addr *)odata;
851 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
852 cand.wants_reconfigure = true;
853 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
854 uint32_t sol_max_rt = ntohl_unaligned(odata);
855 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
856 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
857 cand.sol_max_rt = sol_max_rt;
858 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
859 uint32_t inf_max_rt = ntohl_unaligned(odata);
860 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
861 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
862 cand.inf_max_rt = inf_max_rt;
863 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix &&
864 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
865 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
866 uint8_t *oend = odata + olen, *d;
867 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
868 if (otype == DHCPV6_OPT_IA_PREFIX &&
869 olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) {
870 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
871 have_pd = p->prefix;
872 }
873 }
874 } else if (otype == DHCPV6_OPT_IA_NA &&
875 olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) {
876 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
877 uint8_t *oend = odata + olen, *d;
878 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
879 if (otype == DHCPV6_OPT_IA_ADDR &&
880 olen >= -4 + sizeof(struct dhcpv6_ia_addr))
881 have_na = true;
882 }
883 }
884
885 if ((!have_na && na_mode == IA_MODE_FORCE) ||
886 (!have_pd && pd_mode == IA_MODE_FORCE)) {
887 /*
888 * RFC7083 states to process the SOL_MAX_RT and
889 * INF_MAX_RT options even if the DHCPv6 server
890 * did not propose any IA_NA and/or IA_PD
891 */
892 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
893 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
894 return -1;
895 }
896
897 if (na_mode != IA_MODE_NONE && !have_na) {
898 cand.has_noaddravail = true;
899 cand.preference -= 1000;
900 }
901
902 if (pd_mode != IA_MODE_NONE) {
903 if (have_pd)
904 cand.preference += 2000 + (128 - have_pd);
905 else
906 cand.preference -= 2000;
907 }
908
909 if (cand.duid_len > 0) {
910 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
911 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
912 dhcpv6_add_server_cand(&cand);
913 }
914
915 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
916 }
917
918
919 static int dhcpv6_commit_advert(void)
920 {
921 return dhcpv6_promote_server_cand();
922 }
923
924
925 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
926 const void *opt, const void *end, const struct sockaddr_in6 *from)
927 {
928 dhcpv6_handle_advert(orig, rc, opt, end, from);
929 if (dhcpv6_commit_advert() < 0)
930 return -1;
931
932 return dhcpv6_handle_reply(orig, rc, opt, end, from);
933 }
934
935
936 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
937 const void *opt, const void *end, const struct sockaddr_in6 *from)
938 {
939 uint8_t *odata;
940 uint16_t otype, olen;
941 uint32_t refresh = 86400;
942 int ret = 1;
943 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
944
945 odhcp6c_expire();
946
947 if (orig == DHCPV6_MSG_UNKNOWN) {
948 static time_t last_update = 0;
949 time_t now = odhcp6c_get_milli_time() / 1000;
950
951 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
952 last_update = now;
953
954 if (t1 != UINT32_MAX)
955 t1 -= elapsed;
956
957 if (t2 != UINT32_MAX)
958 t2 -= elapsed;
959
960 if (t3 != UINT32_MAX)
961 t3 -= elapsed;
962
963 if (t1 < 0)
964 t1 = 0;
965
966 if (t2 < 0)
967 t2 = 0;
968
969 if (t3 < 0)
970 t3 = 0;
971 }
972
973 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
974 // Delete NA and PD we have in the state from the Advert
975 odhcp6c_clear_state(STATE_IA_NA);
976 odhcp6c_clear_state(STATE_IA_PD);
977 }
978
979 if (opt) {
980 odhcp6c_clear_state(STATE_DNS);
981 odhcp6c_clear_state(STATE_SEARCH);
982 odhcp6c_clear_state(STATE_SNTP_IP);
983 odhcp6c_clear_state(STATE_NTP_IP);
984 odhcp6c_clear_state(STATE_NTP_FQDN);
985 odhcp6c_clear_state(STATE_SIP_IP);
986 odhcp6c_clear_state(STATE_SIP_FQDN);
987 odhcp6c_clear_state(STATE_AFTR_NAME);
988 odhcp6c_clear_state(STATE_CER);
989 odhcp6c_clear_state(STATE_S46_MAPT);
990 odhcp6c_clear_state(STATE_S46_MAPE);
991 odhcp6c_clear_state(STATE_S46_LW);
992 odhcp6c_clear_state(STATE_PASSTHRU);
993 odhcp6c_clear_state(STATE_CUSTOM_OPTS);
994
995 // Parse and find all matching IAs
996 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
997 bool passthru = true;
998
999 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
1000 && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) {
1001 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
1002
1003 if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) ||
1004 (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD))
1005 continue;
1006
1007 // Test ID
1008 if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA)
1009 continue;
1010
1011 uint16_t code = DHCPV6_Success;
1012 uint16_t stype, slen;
1013 uint8_t *sdata;
1014 // Get and handle status code
1015 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
1016 stype, slen, sdata) {
1017 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
1018 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
1019 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
1020
1021 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
1022
1023 if (code == DHCPV6_Success)
1024 continue;
1025
1026 dhcpv6_handle_ia_status_code(orig, ia_hdr,
1027 code, mdata, mlen, handled_status_codes, &ret);
1028
1029
1030 if (ret > 0)
1031 return ret;
1032 break;
1033 }
1034 }
1035
1036 if (code != DHCPV6_Success)
1037 continue;
1038
1039 dhcpv6_parse_ia(ia_hdr, odata + olen);
1040 passthru = false;
1041 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
1042 server_addr = *(struct in6_addr *)odata;
1043 passthru = false;
1044 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
1045 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
1046 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
1047 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
1048
1049 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
1050 passthru = false;
1051 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
1052 if (olen % 16 == 0)
1053 odhcp6c_add_state(STATE_DNS, odata, olen);
1054 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
1055 odhcp6c_add_state(STATE_SEARCH, odata, olen);
1056 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
1057 if (olen % 16 == 0)
1058 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
1059 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
1060 uint16_t stype, slen;
1061 uint8_t *sdata;
1062 // Test status and bail if error
1063 dhcpv6_for_each_option(odata, odata + olen,
1064 stype, slen, sdata) {
1065 if (slen == 16 && (stype == NTP_MC_ADDR ||
1066 stype == NTP_SRV_ADDR))
1067 odhcp6c_add_state(STATE_NTP_IP,
1068 sdata, slen);
1069 else if (slen > 0 && stype == NTP_SRV_FQDN)
1070 odhcp6c_add_state(STATE_NTP_FQDN,
1071 sdata, slen);
1072 }
1073 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
1074 if (olen == 16)
1075 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
1076 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
1077 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
1078 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
1079 refresh = ntohl_unaligned(odata);
1080 passthru = false;
1081 } else if (otype == DHCPV6_OPT_AUTH) {
1082 if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) {
1083 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
1084 if (r->protocol == 3 && r->algorithm == 1 &&
1085 r->reconf_type == 1)
1086 memcpy(reconf_key, r->key, sizeof(r->key));
1087 }
1088 passthru = false;
1089 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
1090 size_t cur_len;
1091 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
1092 if (cur_len == 0)
1093 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
1094 passthru = false;
1095 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
1096 uint32_t sol_max_rt = ntohl_unaligned(odata);
1097 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
1098 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
1099 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
1100 passthru = false;
1101 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
1102 uint32_t inf_max_rt = ntohl_unaligned(odata);
1103 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
1104 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
1105 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
1106 passthru = false;
1107 #ifdef EXT_CER_ID
1108 } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 +
1109 sizeof(struct dhcpv6_cer_id)) {
1110 struct dhcpv6_cer_id *cer_id = (void*)&odata[-4];
1111 struct in6_addr any = IN6ADDR_ANY_INIT;
1112 if (memcmp(&cer_id->addr, &any, sizeof(any)))
1113 odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any));
1114 passthru = false;
1115 #endif
1116 } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) {
1117 odhcp6c_add_state(STATE_S46_MAPT, odata, olen);
1118 passthru = false;
1119 } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) {
1120 size_t mape_len;
1121 odhcp6c_get_state(STATE_S46_MAPE, &mape_len);
1122 if (mape_len == 0)
1123 odhcp6c_add_state(STATE_S46_MAPE, odata, olen);
1124 passthru = false;
1125 } else if (otype == DHCPV6_OPT_S46_CONT_LW) {
1126 odhcp6c_add_state(STATE_S46_LW, odata, olen);
1127 passthru = false;
1128 } else if (otype == DHCPV6_OPT_CLIENTID ||
1129 otype == DHCPV6_OPT_SERVERID ||
1130 otype == DHCPV6_OPT_IA_TA ||
1131 otype == DHCPV6_OPT_PREF ||
1132 otype == DHCPV6_OPT_UNICAST ||
1133 otype == DHCPV6_OPT_FQDN ||
1134 otype == DHCPV6_OPT_RECONF_ACCEPT) {
1135 passthru = false;
1136 } else {
1137 odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4);
1138 }
1139
1140 if (passthru)
1141 odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4);
1142 }
1143 }
1144
1145 if (orig != DHCPV6_MSG_INFO_REQ) {
1146 // Update refresh timers if no fatal status code was received
1147 if ((ret > 0) && (ret = dhcpv6_calc_refresh_timers())) {
1148 switch (orig) {
1149 case DHCPV6_MSG_RENEW:
1150 // Send further renews if T1 is not set
1151 if (!t1)
1152 ret = -1;
1153 break;
1154 case DHCPV6_MSG_REBIND:
1155 // Send further rebinds if T1 and T2 is not set
1156 if (!t1 && !t2)
1157 ret = -1;
1158 break;
1159
1160 case DHCPV6_MSG_REQUEST:
1161 // All server candidates can be cleared if not yet bound
1162 if (!odhcp6c_is_bound())
1163 dhcpv6_clear_all_server_cand();
1164
1165 default :
1166 break;
1167 }
1168
1169 if (orig == DHCPV6_MSG_REBIND || orig == DHCPV6_MSG_REQUEST) {
1170 odhcp6c_clear_state(STATE_SERVER_ADDR);
1171 odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16);
1172 }
1173 }
1174 }
1175 else if (ret > 0) {
1176 // All server candidates can be cleared if not yet bound
1177 if (!odhcp6c_is_bound())
1178 dhcpv6_clear_all_server_cand();
1179
1180 t1 = refresh;
1181 }
1182
1183 return ret;
1184 }
1185
1186
1187 static int dhcpv6_parse_ia(void *opt, void *end)
1188 {
1189 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1190 int parsed_ia = 0;
1191 uint32_t t1, t2;
1192 uint16_t otype, olen;
1193 uint8_t *odata;
1194
1195 t1 = ntohl(ia_hdr->t1);
1196 t2 = ntohl(ia_hdr->t2);
1197
1198 if (t1 > t2)
1199 return 0;
1200
1201 // Update address IA
1202 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1203 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, 0,
1204 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1205
1206 entry.iaid = ia_hdr->iaid;
1207
1208 if (otype == DHCPV6_OPT_IA_PREFIX) {
1209 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1210 if (olen + 4U < sizeof(*prefix))
1211 continue;
1212
1213 entry.valid = ntohl(prefix->valid);
1214 entry.preferred = ntohl(prefix->preferred);
1215
1216 if (entry.preferred > entry.valid)
1217 continue;
1218
1219 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1220 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1221 if (entry.t1 > entry.t2)
1222 entry.t1 = entry.t2;
1223
1224 entry.length = prefix->prefix;
1225 entry.target = prefix->addr;
1226 uint16_t stype, slen;
1227 uint8_t *sdata;
1228
1229 // Parse PD-exclude
1230 bool ok = true;
1231 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1232 odata + olen, stype, slen, sdata) {
1233 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1234 continue;
1235
1236 uint8_t elen = sdata[0];
1237 if (elen > 64)
1238 elen = 64;
1239
1240 if (entry.length < 32 || elen <= entry.length) {
1241 ok = false;
1242 continue;
1243 }
1244
1245
1246 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1247 if (slen <= bytes) {
1248 ok = false;
1249 continue;
1250 }
1251
1252 uint32_t exclude = 0;
1253 do {
1254 exclude = exclude << 8 | sdata[bytes];
1255 } while (--bytes);
1256
1257 exclude >>= 8 - ((elen - entry.length) % 8);
1258 exclude <<= 64 - elen;
1259
1260 // Abusing router & priority fields for exclusion
1261 entry.router = entry.target;
1262 entry.router.s6_addr32[1] |= htonl(exclude);
1263 entry.priority = elen;
1264 }
1265
1266 if (ok) {
1267 odhcp6c_update_entry(STATE_IA_PD, &entry, 0, false);
1268 parsed_ia++;
1269 }
1270
1271 entry.priority = 0;
1272 memset(&entry.router, 0, sizeof(entry.router));
1273 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1274 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1275 if (olen + 4U < sizeof(*addr))
1276 continue;
1277
1278 entry.preferred = ntohl(addr->preferred);
1279 entry.valid = ntohl(addr->valid);
1280
1281 if (entry.preferred > entry.valid)
1282 continue;
1283
1284 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1285 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1286 if (entry.t1 > entry.t2)
1287 entry.t1 = entry.t2;
1288
1289 entry.length = 128;
1290 entry.target = addr->addr;
1291
1292 odhcp6c_update_entry(STATE_IA_NA, &entry, 0, false);
1293 parsed_ia++;
1294 }
1295 }
1296 return parsed_ia;
1297 }
1298
1299
1300 static int dhcpv6_calc_refresh_timers(void)
1301 {
1302 struct odhcp6c_entry *e;
1303 size_t ia_na_entries, ia_pd_entries, i;
1304 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1305
1306 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1307 ia_na_entries /= sizeof(*e);
1308 for (i = 0; i < ia_na_entries; i++) {
1309 if (e[i].t1 < l_t1)
1310 l_t1 = e[i].t1;
1311
1312 if (e[i].t2 < l_t2)
1313 l_t2 = e[i].t2;
1314
1315 if (e[i].valid > l_t3)
1316 l_t3 = e[i].valid;
1317 }
1318
1319 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1320 ia_pd_entries /= sizeof(*e);
1321 for (i = 0; i < ia_pd_entries; i++) {
1322 if (e[i].t1 < l_t1)
1323 l_t1 = e[i].t1;
1324
1325 if (e[i].t2 < l_t2)
1326 l_t2 = e[i].t2;
1327
1328 if (e[i].valid > l_t3)
1329 l_t3 = e[i].valid;
1330 }
1331
1332 if (ia_pd_entries || ia_na_entries) {
1333 t1 = l_t1;
1334 t2 = l_t2;
1335 t3 = l_t3;
1336 }
1337
1338 return (int)(ia_pd_entries + ia_na_entries);
1339 }
1340
1341
1342 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1343 const void *status_msg, int len)
1344 {
1345 const char *src = status_msg;
1346 char buf[len + 3];
1347 char *dst = buf;
1348
1349 if (len) {
1350 *dst++ = '(';
1351 while (len--) {
1352 *dst = isprint((unsigned char)*src) ? *src : '?';
1353 src++;
1354 dst++;
1355 }
1356 *dst++ = ')';
1357 }
1358 *dst = 0;
1359
1360 syslog(LOG_WARNING, "Server returned %s status %i %s",
1361 scope, code, buf);
1362 }
1363
1364
1365 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1366 const uint16_t code, const void *status_msg, const int len,
1367 int *ret)
1368 {
1369 dhcpv6_log_status_code(code, "message", status_msg, len);
1370
1371 switch (code) {
1372 case DHCPV6_UnspecFail:
1373 // Generic failure
1374 *ret = 0;
1375 break;
1376
1377 case DHCPV6_UseMulticast:
1378 switch(orig) {
1379 case DHCPV6_MSG_REQUEST:
1380 case DHCPV6_MSG_RENEW:
1381 case DHCPV6_MSG_RELEASE:
1382 case DHCPV6_MSG_DECLINE:
1383 // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1384 server_addr = in6addr_any;
1385 *ret = 0;
1386 break;
1387 default:
1388 break;
1389 }
1390 break;
1391
1392 case DHCPV6_NoAddrsAvail:
1393 case DHCPV6_NoPrefixAvail:
1394 if (orig == DHCPV6_MSG_REQUEST)
1395 *ret = 0; // Failure
1396 break;
1397
1398 default:
1399 break;
1400 }
1401 }
1402
1403
1404 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1405 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1406 const void *status_msg, const int len,
1407 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1408 {
1409 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1410 "IA_NA" : "IA_PD", status_msg, len);
1411
1412 switch (code) {
1413 case DHCPV6_NoBinding:
1414 switch (orig) {
1415 case DHCPV6_MSG_RENEW:
1416 case DHCPV6_MSG_REBIND:
1417 if ((*ret > 0) && !handled_status_codes[code])
1418 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1419 break;
1420
1421 default:
1422 break;
1423 }
1424 break;
1425
1426 default:
1427 *ret = 0;
1428 break;
1429 }
1430 }
1431
1432 // Note this always takes ownership of cand->ia_na and cand->ia_pd
1433 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1434 {
1435 size_t cand_len, i;
1436 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1437
1438 // Remove identical duid server candidate
1439 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1440 if (cand->duid_len == c[i].duid_len &&
1441 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1442 free(c[i].ia_na);
1443 free(c[i].ia_pd);
1444 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1445 break;
1446 }
1447 }
1448
1449 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1450 i < cand_len / sizeof(*c); ++i) {
1451 if (c[i].preference < cand->preference)
1452 break;
1453 }
1454
1455 if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) {
1456 free(cand->ia_na);
1457 free(cand->ia_pd);
1458 }
1459 }
1460
1461 static void dhcpv6_clear_all_server_cand(void)
1462 {
1463 size_t cand_len, i;
1464 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1465
1466 // Server candidates need deep delete for IA_NA/IA_PD
1467 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1468 free(c[i].ia_na);
1469 free(c[i].ia_pd);
1470 }
1471 odhcp6c_clear_state(STATE_SERVER_CAND);
1472 }
1473
1474 int dhcpv6_promote_server_cand(void)
1475 {
1476 size_t cand_len;
1477 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1478 uint16_t hdr[2];
1479 int ret = DHCPV6_STATELESS;
1480
1481 // Clear lingering candidate state info
1482 odhcp6c_clear_state(STATE_SERVER_ID);
1483 odhcp6c_clear_state(STATE_IA_NA);
1484 odhcp6c_clear_state(STATE_IA_PD);
1485
1486 if (!cand_len)
1487 return -1;
1488
1489 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1490 na_mode = IA_MODE_NONE;
1491
1492 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1493 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1494
1495 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1496 }
1497
1498 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1499 hdr[1] = htons(cand->duid_len);
1500 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1501 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1502 accept_reconfig = cand->wants_reconfigure;
1503 if (cand->ia_na_len) {
1504 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1505 free(cand->ia_na);
1506 if (na_mode != IA_MODE_NONE)
1507 ret = DHCPV6_STATEFUL;
1508 }
1509 if (cand->ia_pd_len) {
1510 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1511 free(cand->ia_pd);
1512 if (request_prefix)
1513 ret = DHCPV6_STATEFUL;
1514 }
1515
1516 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1517 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1518
1519 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1520
1521 return ret;
1522 }
Openwrt DHCPv6 Client