Merge pull request #6 from fingon/bugfix
[odhcp6c.git] / src / dhcpv6.c
1 /**
2  * Copyright (C) 2012 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 <signal.h>
19 #include <limits.h>
20 #include <resolv.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <syslog.h>
24 #include <stdbool.h>
25 #include <sys/time.h>
26 #include <sys/ioctl.h>
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29
30 #include <net/if.h>
31 #include <net/ethernet.h>
32
33 #include "odhcp6c.h"
34
35
36 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
37                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
38 #define DHCPV6_CLIENT_PORT 546
39 #define DHCPV6_SERVER_PORT 547
40 #define DHCPV6_DUID_LLADDR 3
41 #define DHCPV6_REQ_DELAY 1
42
43
44 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
45                 const uint8_t transaction[3], enum dhcpv6_msg type);
46
47 static uint32_t dhcpv6_parse_ia(void *opt, void *end);
48
49 static reply_handler dhcpv6_handle_reply;
50 static reply_handler dhcpv6_handle_advert;
51 static reply_handler dhcpv6_handle_rebind_reply;
52 static reply_handler dhcpv6_handle_reconfigure;
53 static int dhcpv6_commit_advert(void);
54
55
56
57 // RFC 3315 - 5.5 Timeout and Delay values
58 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
59         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, "<POLL>",
60                         dhcpv6_handle_reconfigure, NULL},
61         [DHCPV6_MSG_SOLICIT] = {true, 1, 120, "SOLICIT",
62                         dhcpv6_handle_advert, dhcpv6_commit_advert},
63         [DHCPV6_MSG_REQUEST] = {true, 30, 10, "REQUEST",
64                         dhcpv6_handle_reply, NULL},
65         [DHCPV6_MSG_RENEW] = {false, 10, 600, "RENEW",
66                         dhcpv6_handle_reply, NULL},
67         [DHCPV6_MSG_REBIND] = {false, 10, 600, "REBIND",
68                         dhcpv6_handle_rebind_reply, NULL},
69         [DHCPV6_MSG_RELEASE] = {false, 1, 600, "RELEASE", NULL, NULL},
70         [DHCPV6_MSG_DECLINE] = {false, 1, 3, "DECLINE", NULL, NULL},
71         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, "INFOREQ",
72                         dhcpv6_handle_reply, NULL},
73 };
74
75
76 // Sockets
77 static int sock = -1;
78 static int ifindex = -1;
79 static int64_t t1 = 0, t2 = 0, t3 = 0;
80
81 // IA states
82 static int request_prefix = -1;
83 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE;
84 static bool accept_reconfig = false;
85
86
87
88 int init_dhcpv6(const char *ifname, int request_pd)
89 {
90         request_prefix = request_pd;
91
92         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
93
94         // Detect interface
95         struct ifreq ifr;
96         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
97         if (ioctl(sock, SIOCGIFINDEX, &ifr))
98                 return -1;
99         ifindex = ifr.ifr_ifindex;
100
101         // Create client DUID
102         size_t client_id_len;
103         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
104         if (client_id_len == 0) {
105                 ioctl(sock, SIOCGIFHWADDR, &ifr);
106                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
107                                 DHCPV6_DUID_LLADDR, 0, 1};
108                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
109
110                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
111                 struct ifreq ifs[100], *ifp, *ifend;
112                 struct ifconf ifc;
113                 ifc.ifc_req = ifs;
114                 ifc.ifc_len = sizeof(ifs);
115
116                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
117                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
118                         // If our interface doesn't have an address...
119                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
120                         for (ifp = ifc.ifc_req; ifp < ifend &&
121                                         !memcmp(&duid[8], zero, 6); ifp++) {
122                                 memcpy(ifr.ifr_name, ifp->ifr_name,
123                                                 sizeof(ifr.ifr_name));
124                                 ioctl(sock, SIOCGIFHWADDR, &ifr);
125                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
126                                                 ETHER_ADDR_LEN);
127                         }
128                 }
129
130                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
131         }
132
133         // Create ORO
134         uint16_t oro[] = {htons(DHCPV6_OPT_DNS_SERVERS),
135                         htons(DHCPV6_OPT_DNS_DOMAIN),
136                         htons(DHCPV6_OPT_NTP_SERVER),
137                         htons(DHCPV6_OPT_SIP_SERVER_A),
138                         htons(DHCPV6_OPT_SIP_SERVER_D)};
139         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
140
141
142         // Configure IPv6-options
143         int val = 1;
144         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
145         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
146         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
147
148         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
149                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
150         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)))
151                 return -1;
152
153         return 0;
154 }
155
156
157 void dhcpv6_set_ia_na_mode(enum odhcp6c_ia_mode mode)
158 {
159         na_mode = mode;
160 }
161
162
163 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
164 {
165         // Build FQDN
166         char fqdn_buf[256];
167         gethostname(fqdn_buf, sizeof(fqdn_buf));
168         struct {
169                 uint16_t type;
170                 uint16_t len;
171                 uint8_t flags;
172                 uint8_t data[256];
173         } fqdn;
174         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
175                         sizeof(fqdn.data), NULL, NULL);
176         fqdn.type = htons(DHCPV6_OPT_FQDN);
177         fqdn.len = htons(fqdn_len - 4);
178         fqdn.flags = 0;
179
180
181         // Build Client ID
182         size_t cl_id_len;
183         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
184
185         // Get Server ID
186         size_t srv_id_len;
187         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
188
189         // Build IA_PDs
190         size_t ia_pd_entries, ia_pd_len = 0;
191         void *ia_pd = NULL;
192         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
193         ia_pd_entries /= sizeof(*e);
194         struct dhcpv6_ia_hdr hdr_ia_pd = {
195                 htons(DHCPV6_OPT_IA_PD),
196                 htons(sizeof(hdr_ia_pd) - 4),
197                 1, 0, 0
198         };
199
200         struct dhcpv6_ia_prefix pref = {
201                 .type = htons(DHCPV6_OPT_IA_PREFIX),
202                 .len = htons(25), .prefix = request_prefix
203         };
204
205
206         struct dhcpv6_ia_prefix p[ia_pd_entries];
207         for (size_t i = 0; i < ia_pd_entries; ++i) {
208                 p[i].type = htons(DHCPV6_OPT_IA_PREFIX);
209                 p[i].len = htons(sizeof(p[i]) - 4U);
210                 p[i].preferred = 0;
211                 p[i].valid = 0;
212                 p[i].prefix = e[i].length;
213                 p[i].addr = e[i].target;
214         }
215         ia_pd = p;
216         ia_pd_len = sizeof(p);
217         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
218
219         if (request_prefix > 0 &&
220                         (type == DHCPV6_MSG_SOLICIT ||
221                         type == DHCPV6_MSG_REQUEST)) {
222                 ia_pd = &pref;
223                 ia_pd_len = sizeof(pref);
224                 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
225         }
226
227         // Build IA_NAs
228         size_t ia_na_entries, ia_na_len = 0;
229         void *ia_na = NULL;
230         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
231         ia_na_entries /= sizeof(*e);
232
233         struct dhcpv6_ia_hdr hdr_ia_na = {
234                 htons(DHCPV6_OPT_IA_NA),
235                 htons(sizeof(hdr_ia_na) - 4),
236                 1, 0, 0
237         };
238
239         struct dhcpv6_ia_addr pa[ia_na_entries];
240         for (size_t i = 0; i < ia_na_entries; ++i) {
241                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
242                 pa[i].len = htons(sizeof(pa[i]) - 4U);
243                 pa[i].addr = e[i].target;
244                 pa[i].preferred = 0;
245                 pa[i].valid = 0;
246         }
247
248         ia_na = pa;
249         ia_na_len = sizeof(pa);
250         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
251
252         // Reconfigure Accept
253         struct {
254                 uint16_t type;
255                 uint16_t length;
256         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
257
258         // Request Information Refresh
259         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
260
261         // Prepare Header
262         size_t oro_len;
263         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
264         struct {
265                 uint8_t type;
266                 uint8_t trid[3];
267                 uint16_t elapsed_type;
268                 uint16_t elapsed_len;
269                 uint16_t elapsed_value;
270                 uint16_t oro_type;
271                 uint16_t oro_len;
272         } hdr = {
273                 type, {trid[0], trid[1], trid[2]},
274                 htons(DHCPV6_OPT_ELAPSED), htons(2),
275                         htons((ecs > 0xffff) ? 0xffff : ecs),
276                 htons(DHCPV6_OPT_ORO), htons(oro_len),
277         };
278
279         struct iovec iov[] = {
280                 {&hdr, sizeof(hdr)},
281                 {oro, oro_len},
282                 {&oro_refresh, 0},
283                 {cl_id, cl_id_len},
284                 {srv_id, srv_id_len},
285                 {&reconf_accept, 0},
286                 {&fqdn, fqdn_len},
287                 {&hdr_ia_na, sizeof(hdr_ia_na)},
288                 {ia_na, ia_na_len},
289                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
290                 {ia_pd, ia_pd_len},
291         };
292
293         size_t cnt = ARRAY_SIZE(iov);
294         if (type == DHCPV6_MSG_INFO_REQ) {
295                 cnt = 5;
296                 iov[2].iov_len = sizeof(oro_refresh);
297                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
298         } else if (!request_prefix) {
299                 cnt = 9;
300         }
301
302         // Disable IAs if not used
303         if (type == DHCPV6_MSG_SOLICIT) {
304                 iov[5].iov_len = sizeof(reconf_accept);
305         } else if (type != DHCPV6_MSG_REQUEST) {
306                 if (ia_na_len == 0)
307                         iov[7].iov_len = 0;
308                 if (ia_pd_len == 0)
309                         iov[9].iov_len = 0;
310         }
311
312         if (na_mode == IA_MODE_NONE)
313                 iov[7].iov_len = 0;
314
315         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
316                 0, ALL_DHCPV6_RELAYS, ifindex};
317         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
318
319         sendmsg(sock, &msg, 0);
320 }
321
322
323 static int64_t dhcpv6_rand_delay(int64_t time)
324 {
325         int random;
326         odhcp6c_random(&random, sizeof(random));
327         return (time * (random % 1000)) / 10000;
328 }
329
330
331 int dhcpv6_request(enum dhcpv6_msg type)
332 {
333         uint8_t buf[1536];
334         uint32_t timeout = UINT32_MAX;
335         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
336
337         if (retx->delay) {
338                 struct timespec ts = {0, 0};
339                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
340                 nanosleep(&ts, NULL);
341         }
342
343         if (type == DHCPV6_MSG_RELEASE || type == DHCPV6_MSG_DECLINE)
344                 timeout = 3;
345         else if (type == DHCPV6_MSG_UNKNOWN)
346                 timeout = t1;
347         else if (type == DHCPV6_MSG_RENEW)
348                 timeout = t2 - t1;
349         else if (type == DHCPV6_MSG_REBIND)
350                 timeout = t3 - t2;
351
352         if (timeout == 0)
353                 return -1;
354
355         syslog(LOG_NOTICE, "Sending %s (timeout %us)", retx->name, timeout);
356
357         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
358
359         // Generate transaction ID
360         uint8_t trid[3];
361         odhcp6c_random(trid, sizeof(trid));
362         ssize_t len = -1;
363         int64_t rto = 0;
364
365         do {
366                 rto = (rto == 0) ? (retx->init_timeo * 1000 +
367                                 dhcpv6_rand_delay(retx->init_timeo * 1000)) :
368                                 (2 * rto + dhcpv6_rand_delay(rto));
369
370                 if (rto >= retx->max_timeo * 1000)
371                         rto = retx->max_timeo * 1000 +
372                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
373
374                 // Calculate end for this round and elapsed time
375                 uint64_t round_end = round_start + rto;
376                 elapsed = round_start - start;
377
378                 // Don't wait too long
379                 if (round_end - start > timeout * 1000)
380                         round_end = timeout * 1000 + start;
381
382                 // Built and send package
383                 if (type != DHCPV6_MSG_UNKNOWN)
384                         dhcpv6_send(type, trid, elapsed / 10);
385
386                 // Receive rounds
387                 for (; len < 0 && round_start < round_end;
388                                 round_start = odhcp6c_get_milli_time()) {
389                         // Check for pending signal
390                         if (odhcp6c_signal_process())
391                                 return -1;
392
393                         // Set timeout for receiving
394                         uint64_t t = round_end - round_start;
395                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
396                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
397                                         &timeout, sizeof(timeout));
398
399                         // Receive cycle
400                         len = recv(sock, buf, sizeof(buf), 0);
401
402                         if (!dhcpv6_response_is_valid(buf, len, trid, type))
403                                 len = -1;
404
405                         if (len > 0) {
406                                 uint8_t *opt = &buf[4];
407                                 uint8_t *opt_end = opt + len - 4;
408
409                                 round_start = odhcp6c_get_milli_time();
410                                 elapsed = round_start - start;
411                                 syslog(LOG_NOTICE, "Got a valid reply after "
412                                                 "%ums", (unsigned)elapsed);
413
414                                 if (retx->handler_reply)
415                                         len = retx->handler_reply(
416                                                         type, opt, opt_end);
417
418                                 if (round_end - round_start > 1000)
419                                         round_end = 1000 + round_start;
420                         }
421                 }
422
423                 // Allow
424                 if (retx->handler_finish)
425                         len = retx->handler_finish();
426         } while (len < 0 && elapsed / 1000 < timeout);
427
428         return len;
429 }
430
431
432 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
433                 const uint8_t transaction[3], enum dhcpv6_msg type)
434 {
435         const struct dhcpv6_header *rep = buf;
436         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
437                         transaction, sizeof(rep->tr_id)))
438                 return false; // Invalid reply
439
440         if (type == DHCPV6_MSG_SOLICIT) {
441                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
442                                 rep->msg_type != DHCPV6_MSG_REPLY)
443                         return false;
444         } else if (type == DHCPV6_MSG_UNKNOWN) {
445                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
446                         return false;
447         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
448                 return false;
449         }
450
451         uint8_t *end = ((uint8_t*)buf) + len, *odata;
452         uint16_t otype, olen;
453         bool clientid_ok = false, serverid_ok = false;
454
455         size_t client_id_len, server_id_len;
456         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
457         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
458
459         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata)
460                 if (otype == DHCPV6_OPT_CLIENTID)
461                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
462                                         &odata[-4], client_id, client_id_len);
463                 else if (otype == DHCPV6_OPT_SERVERID)
464                         serverid_ok = (olen + 4U == server_id_len) && !memcmp(
465                                         &odata[-4], server_id, server_id_len);
466
467         return clientid_ok && (serverid_ok || server_id_len == 0);
468 }
469
470
471 int dhcpv6_poll_reconfigure(void)
472 {
473         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
474         if (ret != -1)
475                 ret = dhcpv6_request(ret);
476
477         return ret;
478 }
479
480
481 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig,
482                 const void *opt, const void *end)
483 {
484         // TODO: should verify the reconfigure message
485         uint16_t otype, olen;
486         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
487         dhcpv6_for_each_option(opt, end, otype, olen, odata)
488                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
489                                 odata[0] == DHCPV6_MSG_RENEW ||
490                                 odata[0] == DHCPV6_MSG_INFO_REQ))
491                         msg = odata[0];
492
493         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL);
494         return msg;
495 }
496
497
498 // Collect all advertised servers
499 static int dhcpv6_handle_advert(_unused enum dhcpv6_msg orig,
500                 const void *opt, const void *end)
501 {
502         uint16_t olen, otype;
503         uint8_t *odata;
504         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}};
505
506         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
507                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
508                         memcpy(cand.duid, odata, olen);
509                         cand.duid_len = olen;
510                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0]
511                                 && odata[1] == DHCPV6_NoAddrsAvail) {
512                         if (na_mode == IA_MODE_FORCE) {
513                                 return -1;
514                         } else {
515                                 cand.has_noaddravail = true;
516                                 cand.preference -= 1000;
517                         }
518                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0]
519                                 && odata[1] == DHCPV6_NoPrefixAvail) {
520                         cand.preference -= 2000;
521                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
522                                 cand.preference >= 0) {
523                         cand.preference = odata[0];
524                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
525                         cand.wants_reconfigure = true;
526                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
527                         struct dhcpv6_ia_hdr *h = (void*)odata;
528                         uint8_t *oend = odata + olen, *d;
529                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
530                                 if (otype == DHCPV6_OPT_IA_PREFIX)
531                                         cand.preference += 2000;
532                                 else if (otype == DHCPV6_OPT_STATUS &&
533                                                 olen >= 2 && d[0] == 0 &&
534                                                 d[1] == DHCPV6_NoPrefixAvail)
535                                         cand.preference -= 2000;
536                         }
537                 }
538         }
539
540         if (cand.duid_len > 0)
541                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
542
543         return -1;
544 }
545
546
547 static int dhcpv6_commit_advert(void)
548 {
549         size_t cand_len;
550         struct dhcpv6_server_cand *c = NULL, *cand =
551                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
552
553         bool retry = false;
554         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
555                 if (cand[i].has_noaddravail)
556                         retry = true; // We want to try again
557
558                 if (!c || c->preference < cand[i].preference)
559                         c = &cand[i];
560         }
561
562         if (retry && na_mode == IA_MODE_TRY) {
563                 // We give it a second try without the IA_NA
564                 na_mode = IA_MODE_NONE;
565                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
566         }
567
568         if (c) {
569                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
570                                 htons(c->duid_len)};
571                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
572                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
573                 accept_reconfig = c->wants_reconfigure;
574         }
575
576         odhcp6c_clear_state(STATE_SERVER_CAND);
577
578         if (!c)
579                 return -1;
580         else if (request_prefix || na_mode != IA_MODE_NONE)
581                 return DHCPV6_STATEFUL;
582         else
583                 return DHCPV6_STATELESS;
584 }
585
586
587 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig,
588                 const void *opt, const void *end)
589 {
590         dhcpv6_handle_advert(orig, opt, end);
591         if (dhcpv6_commit_advert() < 0) {
592                 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL);
593                 return -1;
594         }
595
596         return dhcpv6_handle_reply(orig, opt, end);
597 }
598
599
600 static int dhcpv6_handle_reply(enum dhcpv6_msg orig,
601                 const void *opt, const void *end)
602 {
603         uint8_t *odata;
604         uint16_t otype, olen;
605
606         static time_t last_update = 0;
607         time_t now = odhcp6c_get_milli_time() / 1000;
608
609         uint32_t elapsed = now - last_update;
610         odhcp6c_expire();
611
612         if (orig == DHCPV6_MSG_UNKNOWN) {
613                 t1 -= elapsed;
614                 t2 -= elapsed;
615                 t3 -= elapsed;
616
617                 if (t1 < 0)
618                         t1 = 0;
619
620                 if (t2 < 0)
621                         t2 = 0;
622
623                 if (t3 < 0)
624                         t3 = 0;
625         } else {
626                 t1 = t2 = t3 = UINT32_MAX;
627         }
628
629         if (opt) {
630                 odhcp6c_clear_state(STATE_DNS);
631                 odhcp6c_clear_state(STATE_SEARCH);
632                 odhcp6c_clear_state(STATE_SNTP_IP);
633                 odhcp6c_clear_state(STATE_SNTP_FQDN);
634                 odhcp6c_clear_state(STATE_SIP_IP);
635                 odhcp6c_clear_state(STATE_SIP_FQDN);
636         }
637
638         // Parse and find all matching IAs
639         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
640                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
641                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
642                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
643                         uint32_t l_t1 = ntohl(ia_hdr->t1);
644                         uint32_t l_t2 = ntohl(ia_hdr->t2);
645
646                         // Test ID and T1-T2 validity
647                         if (ia_hdr->iaid != 1 || l_t2 < l_t1)
648                                 continue;
649
650                         bool error = false;
651                         uint16_t stype, slen;
652                         uint8_t *sdata;
653                         // Test status and bail if error
654                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
655                                         stype, slen, sdata)
656                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2 &&
657                                                 (sdata[0] || sdata[1]))
658                                         error = true;
659
660                         if (error)
661                                 continue;
662
663                         // Update times
664                         if (l_t1 > 0 && t1 > l_t1)
665                                 t1 = l_t1;
666
667                         if (l_t2 > 0 && t2 > l_t2)
668                                 t2 = l_t2;
669
670                         uint32_t n = dhcpv6_parse_ia(&ia_hdr[1], odata + olen);
671
672                         if (n < t1)
673                                 t1 = n;
674
675                         if (n < t2)
676                                 t2 = n;
677
678                         if (n < t3)
679                                 t3 = n;
680
681                         if (t2 >= t3)
682                                 t2 = 8 * t3 / 10;
683
684                         if (t1 >= t2)
685                                 t1 = 5 * t2 / 8;
686
687                 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
688                         if (olen % 16 == 0)
689                                 odhcp6c_add_state(STATE_DNS, odata, olen);
690                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
691                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
692                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
693                         uint16_t stype, slen;
694                         uint8_t *sdata;
695                         // Test status and bail if error
696                         dhcpv6_for_each_option(odata, odata + olen,
697                                         stype, slen, sdata) {
698                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
699                                                 stype == NTP_SRV_ADDR))
700                                         odhcp6c_add_state(STATE_SNTP_IP,
701                                                         sdata, slen);
702                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
703                                         odhcp6c_add_state(STATE_SNTP_FQDN,
704                                                         sdata, slen);
705                         }
706                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
707                         if (olen == 16)
708                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
709                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
710                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
711                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
712                         uint32_t refresh = ntohl(*((uint32_t*)odata));
713                         if (refresh < (uint32_t)t1)
714                                 t1 = refresh;
715                 } else if (otype != DHCPV6_OPT_CLIENTID &&
716                                 otype != DHCPV6_OPT_SERVERID) {
717                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
718                                         &odata[-4], olen + 4);
719                 }
720         }
721
722         return true;
723 }
724
725
726 static uint32_t dhcpv6_parse_ia(void *opt, void *end)
727 {
728         uint32_t timeout = UINT32_MAX; // Minimum timeout
729         uint16_t otype, olen;
730         uint8_t *odata;
731
732         struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT,
733                         0, 0, IN6ADDR_ANY_INIT, 0, 0};
734
735         // Update address IA
736         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
737                 if (otype == DHCPV6_OPT_IA_PREFIX) {
738                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
739                         if (olen + 4U < sizeof(*prefix))
740                                 continue;
741
742                         entry.valid = ntohl(prefix->valid);
743                         entry.preferred = ntohl(prefix->preferred);
744
745                         if (entry.preferred > entry.valid)
746                                 continue;
747
748                         entry.length = prefix->prefix;
749                         entry.target = prefix->addr;
750
751                         odhcp6c_update_entry(STATE_IA_PD, &entry);
752                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
753                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
754                         if (olen + 4U < sizeof(*addr))
755                                 continue;
756
757                         entry.preferred = ntohl(addr->preferred);
758                         entry.valid = ntohl(addr->valid);
759
760                         if (entry.preferred > entry.valid)
761                                 continue;
762
763                         entry.length = 128;
764                         entry.target = addr->addr;
765
766                         odhcp6c_update_entry(STATE_IA_NA, &entry);
767                 }
768
769                 if (entry.valid > 0 && timeout > entry.valid)
770                         timeout = entry.valid;
771         }
772
773         return timeout;
774 }