Server unicast option support
[odhcp6c.git] / src / dhcpv6.c
1 /**
2  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License v2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14
15 #include <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <arpa/inet.h>
30 #include <netinet/in.h>
31
32 #include <net/if.h>
33 #include <net/ethernet.h>
34
35 #include "odhcp6c.h"
36 #include "md5.h"
37
38
39 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
40                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
41 #define DHCPV6_CLIENT_PORT 546
42 #define DHCPV6_SERVER_PORT 547
43 #define DHCPV6_DUID_LLADDR 3
44 #define DHCPV6_REQ_DELAY 1
45
46
47 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
48                 const uint8_t transaction[3], enum dhcpv6_msg type,
49                 const struct in6_addr *daddr);
50
51 static int dhcpv6_parse_ia(void *opt, void *end);
52
53 static int dhcpv6_calc_refresh_timers(void);
54 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
55                 const uint16_t code, const void *status_msg, const int len,
56                 int *ret);
57 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
58                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
59                 const void *status_msg, const int len,
60                 bool handled_status_codes[_DHCPV6_Status_Max],
61                 int *ret);
62
63 static reply_handler dhcpv6_handle_reply;
64 static reply_handler dhcpv6_handle_advert;
65 static reply_handler dhcpv6_handle_rebind_reply;
66 static reply_handler dhcpv6_handle_reconfigure;
67 static int dhcpv6_commit_advert(void);
68
69
70
71 // RFC 3315 - 5.5 Timeout and Delay values
72 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
73         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
74                         dhcpv6_handle_reconfigure, NULL},
75         [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
76                         dhcpv6_handle_advert, dhcpv6_commit_advert},
77         [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
78                         dhcpv6_handle_reply, NULL},
79         [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
80                         dhcpv6_handle_reply, NULL},
81         [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
82                         dhcpv6_handle_rebind_reply, NULL},
83         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
84         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
85         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
86                         dhcpv6_handle_reply, NULL},
87 };
88
89
90 // Sockets
91 static int sock = -1;
92 static int ifindex = -1;
93 static int64_t t1 = 0, t2 = 0, t3 = 0;
94
95 // IA states
96 static int request_prefix = -1;
97 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
98 static bool accept_reconfig = false;
99 // Server unicast address
100 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
101
102 // Reconfigure key
103 static uint8_t reconf_key[16];
104
105
106 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
107 {
108         request_prefix = request_pd;
109         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
110
111         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
112         if (sock < 0)
113                 return -1;
114
115         // Detect interface
116         struct ifreq ifr;
117         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
118         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
119                 return -1;
120         ifindex = ifr.ifr_ifindex;
121
122         // Create client DUID
123         size_t client_id_len;
124         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
125         if (client_id_len == 0) {
126                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
127                                 DHCPV6_DUID_LLADDR, 0, 1};
128
129                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
130                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
131
132                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
133                 struct ifreq ifs[100], *ifp, *ifend;
134                 struct ifconf ifc;
135                 ifc.ifc_req = ifs;
136                 ifc.ifc_len = sizeof(ifs);
137
138                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
139                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
140                         // If our interface doesn't have an address...
141                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
142                         for (ifp = ifc.ifc_req; ifp < ifend &&
143                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
144                                 memcpy(ifr.ifr_name, ifp->ifr_name,
145                                                 sizeof(ifr.ifr_name));
146                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
147                                         continue;
148                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
149                                                 ETHER_ADDR_LEN);
150                         }
151                 }
152
153                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
154         }
155
156         // Create ORO
157         uint16_t oro[] = {
158                         htons(DHCPV6_OPT_SIP_SERVER_D),
159                         htons(DHCPV6_OPT_SIP_SERVER_A),
160                         htons(DHCPV6_OPT_DNS_SERVERS),
161                         htons(DHCPV6_OPT_DNS_DOMAIN),
162                         htons(DHCPV6_OPT_UNICAST),
163                         htons(DHCPV6_OPT_NTP_SERVER),
164                         htons(DHCPV6_OPT_AFTR_NAME),
165                         htons(DHCPV6_OPT_PD_EXCLUDE),
166 #ifdef EXT_PREFIX_CLASS
167                         htons(DHCPV6_OPT_PREFIX_CLASS),
168 #endif
169         };
170         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
171
172         do {
173                 // Configure IPv6-options
174                 int val = 1;
175                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
176                         break;
177                 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
178                         break;
179                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
180                         break;
181
182                 val = 0;
183                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)) < 0)
184                         break;
185                 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
186                         break;
187
188                 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
189                         .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
190                 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
191                         break;
192
193                 return 0;
194         } while (0);
195
196         return -1;
197 }
198
199
200 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
201 {
202         na_mode = na;
203         pd_mode = pd;
204 }
205
206
207 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
208 {
209         // Build FQDN
210         char fqdn_buf[256];
211         gethostname(fqdn_buf, sizeof(fqdn_buf));
212         struct {
213                 uint16_t type;
214                 uint16_t len;
215                 uint8_t flags;
216                 uint8_t data[256];
217         } fqdn;
218         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
219                         sizeof(fqdn.data), NULL, NULL);
220         fqdn.type = htons(DHCPV6_OPT_FQDN);
221         fqdn.len = htons(fqdn_len - 4);
222         fqdn.flags = 0;
223
224
225         // Build Client ID
226         size_t cl_id_len;
227         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
228
229         // Get Server ID
230         size_t srv_id_len;
231         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
232
233         // Build IA_PDs
234         size_t ia_pd_entries, ia_pd_len = 0;
235         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
236         ia_pd_entries /= sizeof(*e);
237         struct dhcpv6_ia_hdr hdr_ia_pd = {
238                 htons(DHCPV6_OPT_IA_PD),
239                 htons(sizeof(hdr_ia_pd) - 4),
240                 1, 0, 0
241         };
242
243
244         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
245         for (size_t i = 0; i < ia_pd_entries; ++i) {
246                 uint8_t ex_len = 0;
247                 if (e[i].priority > 0)
248                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
249
250                 struct dhcpv6_ia_prefix p = {
251                         .type = htons(DHCPV6_OPT_IA_PREFIX),
252                         .len = htons(sizeof(p) - 4U + ex_len),
253                         .prefix = e[i].length,
254                         .addr = e[i].target
255                 };
256
257                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
258                 ia_pd_len += sizeof(p);
259
260                 if (ex_len) {
261                         ia_pd[ia_pd_len++] = 0;
262                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
263                         ia_pd[ia_pd_len++] = 0;
264                         ia_pd[ia_pd_len++] = ex_len - 4;
265                         ia_pd[ia_pd_len++] = e[i].priority;
266
267                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
268                         excl >>= (64 - e[i].priority);
269                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
270
271                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
272                                 ia_pd[ia_pd_len + i] = excl & 0xff;
273                         ia_pd_len += ex_len - 5;
274                 }
275         }
276
277         struct dhcpv6_ia_prefix pref = {
278                 .type = htons(DHCPV6_OPT_IA_PREFIX),
279                 .len = htons(25), .prefix = request_prefix
280         };
281         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
282                 ia_pd = (uint8_t*)&pref;
283                 ia_pd_len = sizeof(pref);
284         }
285         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
286
287         // Build IA_NAs
288         size_t ia_na_entries, ia_na_len = 0;
289         void *ia_na = NULL;
290         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
291         ia_na_entries /= sizeof(*e);
292
293         struct dhcpv6_ia_hdr hdr_ia_na = {
294                 htons(DHCPV6_OPT_IA_NA),
295                 htons(sizeof(hdr_ia_na) - 4),
296                 1, 0, 0
297         };
298
299         struct dhcpv6_ia_addr pa[ia_na_entries];
300         for (size_t i = 0; i < ia_na_entries; ++i) {
301                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
302                 pa[i].len = htons(sizeof(pa[i]) - 4U);
303                 pa[i].addr = e[i].target;
304                 pa[i].preferred = 0;
305                 pa[i].valid = 0;
306         }
307
308         ia_na = pa;
309         ia_na_len = sizeof(pa);
310         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
311
312         // Reconfigure Accept
313         struct {
314                 uint16_t type;
315                 uint16_t length;
316         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
317
318         // Request Information Refresh
319         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
320
321         // Prepare Header
322         size_t oro_len;
323         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
324         struct {
325                 uint8_t type;
326                 uint8_t trid[3];
327                 uint16_t elapsed_type;
328                 uint16_t elapsed_len;
329                 uint16_t elapsed_value;
330                 uint16_t oro_type;
331                 uint16_t oro_len;
332         } hdr = {
333                 type, {trid[0], trid[1], trid[2]},
334                 htons(DHCPV6_OPT_ELAPSED), htons(2),
335                         htons((ecs > 0xffff) ? 0xffff : ecs),
336                 htons(DHCPV6_OPT_ORO), htons(oro_len),
337         };
338
339         struct iovec iov[] = {
340                 {&hdr, sizeof(hdr)},
341                 {oro, oro_len},
342                 {&oro_refresh, 0},
343                 {cl_id, cl_id_len},
344                 {srv_id, srv_id_len},
345                 {&reconf_accept, sizeof(reconf_accept)},
346                 {&fqdn, fqdn_len},
347                 {&hdr_ia_na, sizeof(hdr_ia_na)},
348                 {ia_na, ia_na_len},
349                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
350                 {ia_pd, ia_pd_len},
351         };
352
353         size_t cnt = ARRAY_SIZE(iov);
354         if (type == DHCPV6_MSG_INFO_REQ) {
355                 cnt = 5;
356                 iov[2].iov_len = sizeof(oro_refresh);
357                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
358         } else if (!request_prefix) {
359                 cnt = 9;
360         }
361
362         // Disable IAs if not used
363         if (type != DHCPV6_MSG_SOLICIT) {
364                 iov[5].iov_len = 0;
365                 if (ia_na_len == 0)
366                         iov[7].iov_len = 0;
367                 if (ia_pd_len == 0)
368                         iov[9].iov_len = 0;
369         }
370
371         if (na_mode == IA_MODE_NONE)
372                 iov[7].iov_len = 0;
373
374         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
375                 0, ALL_DHCPV6_RELAYS, ifindex};
376         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
377
378         switch (type) {
379         case DHCPV6_MSG_REQUEST:
380         case DHCPV6_MSG_RENEW:
381         case DHCPV6_MSG_RELEASE:
382         case DHCPV6_MSG_DECLINE:
383                 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
384                         odhcp6c_addr_in_scope(&server_addr)) {
385                         srv.sin6_addr = server_addr;
386                         if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
387                                 srv.sin6_scope_id = 0;
388                 }
389                 break;
390         default:
391                 break;
392         }
393
394         if (sendmsg(sock, &msg, 0) < 0) {
395                 char in6_str[INET6_ADDRSTRLEN];
396
397                 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
398                         inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
399                                 in6_str, sizeof(in6_str)), strerror(errno));
400         }
401 }
402
403
404 static int64_t dhcpv6_rand_delay(int64_t time)
405 {
406         int random;
407         odhcp6c_random(&random, sizeof(random));
408         return (time * ((int64_t)random % 1000LL)) / 10000LL;
409 }
410
411
412 int dhcpv6_request(enum dhcpv6_msg type)
413 {
414         uint8_t rc = 0;
415         uint64_t timeout = UINT32_MAX;
416         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
417
418         if (retx->delay) {
419                 struct timespec ts = {0, 0};
420                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
421                 nanosleep(&ts, NULL);
422         }
423
424         if (type == DHCPV6_MSG_UNKNOWN)
425                 timeout = t1;
426         else if (type == DHCPV6_MSG_RENEW)
427                 timeout = (t2 > t1) ? t2 - t1 : 0;
428         else if (type == DHCPV6_MSG_REBIND)
429                 timeout = (t3 > t2) ? t3 - t2 : 0;
430
431         if (timeout == 0)
432                 return -1;
433
434         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
435                         retx->name, (unsigned long long)timeout, retx->max_rc);
436
437         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
438
439         // Generate transaction ID
440         uint8_t trid[3] = {0, 0, 0};
441         if (type != DHCPV6_MSG_UNKNOWN)
442                 odhcp6c_random(trid, sizeof(trid));
443         ssize_t len = -1;
444         int64_t rto = 0;
445
446         do {
447                 if (rto == 0) {
448                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
449
450                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
451                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
452                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
453
454                         rto = (retx->init_timeo * 1000 + delay);
455                 }
456                 else
457                         rto = (2 * rto + dhcpv6_rand_delay(rto));
458
459                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
460                         rto = retx->max_timeo * 1000 +
461                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
462
463                 // Calculate end for this round and elapsed time
464                 uint64_t round_end = round_start + rto;
465                 elapsed = round_start - start;
466
467                 // Don't wait too long
468                 if (round_end - start > timeout * 1000)
469                         round_end = timeout * 1000 + start;
470
471                 // Built and send package
472                 if (type != DHCPV6_MSG_UNKNOWN) {
473                         if (type != DHCPV6_MSG_SOLICIT)
474                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
475                                                 retx->name, (unsigned long long)elapsed, rc);
476                         dhcpv6_send(type, trid, elapsed / 10);
477                         rc++;
478                 }
479
480                 // Receive rounds
481                 for (; len < 0 && round_start < round_end;
482                                 round_start = odhcp6c_get_milli_time()) {
483                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
484                         struct iovec iov = {buf, sizeof(buf)};
485                         struct msghdr msg = {NULL, 0, &iov, 1,
486                                         cmsg_buf, sizeof(cmsg_buf), 0};
487                         struct in6_pktinfo *pktinfo = NULL;
488
489                         // Check for pending signal
490                         if (odhcp6c_signal_process())
491                                 return -1;
492
493                         // Set timeout for receiving
494                         uint64_t t = round_end - round_start;
495                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
496                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
497                                         &timeout, sizeof(timeout));
498
499                         // Receive cycle
500                         len = recvmsg(sock, &msg, 0);
501                         if (len < 0)
502                                 continue;
503
504                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
505                                 ch = CMSG_NXTHDR(&msg, ch)) {
506                                 if (ch->cmsg_level == SOL_IPV6 &&
507                                         ch->cmsg_type == IPV6_PKTINFO) {
508                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
509                                         break;
510                                 }
511                         }
512
513                         if (pktinfo == NULL) {
514                                 len = -1;
515                                 continue;
516                         }
517
518                         if (!dhcpv6_response_is_valid(buf, len, trid,
519                                                         type, &pktinfo->ipi6_addr)) {
520                                 len = -1;
521                                 continue;
522                         }
523
524                         uint8_t *opt = &buf[4];
525                         uint8_t *opt_end = opt + len - 4;
526
527                         round_start = odhcp6c_get_milli_time();
528                         elapsed = round_start - start;
529                         syslog(LOG_NOTICE, "Got a valid reply after "
530                                         "%llums", (unsigned long long)elapsed);
531
532                         if (retx->handler_reply)
533                                 len = retx->handler_reply(type, rc, opt, opt_end);
534
535                         if (len > 0 && round_end - round_start > 1000)
536                                 round_end = 1000 + round_start;
537                 }
538
539                 // Allow
540                 if (retx->handler_finish)
541                         len = retx->handler_finish();
542         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
543
544         return len;
545 }
546
547 // Message validation checks according to RFC3315 chapter 15
548 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
549                 const uint8_t transaction[3], enum dhcpv6_msg type,
550                 const struct in6_addr *daddr)
551 {
552         const struct dhcpv6_header *rep = buf;
553         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
554                         transaction, sizeof(rep->tr_id)))
555                 return false; // Invalid reply
556
557         if (type == DHCPV6_MSG_SOLICIT) {
558                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
559                                 rep->msg_type != DHCPV6_MSG_REPLY)
560                         return false;
561         } else if (type == DHCPV6_MSG_UNKNOWN) {
562                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
563                         return false;
564         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
565                 return false;
566         }
567
568         uint8_t *end = ((uint8_t*)buf) + len, *odata,
569                 rcmsg = DHCPV6_MSG_UNKNOWN;
570         uint16_t otype, olen;
571         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
572                 ia_present = false, options_valid = true;
573
574         size_t client_id_len, server_id_len;
575         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
576         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
577
578         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
579                 if (otype == DHCPV6_OPT_CLIENTID) {
580                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
581                                         &odata[-4], client_id, client_id_len);
582                 } else if (otype == DHCPV6_OPT_SERVERID) {
583                         if (server_id_len)
584                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
585                                                 &odata[-4], server_id, server_id_len);
586                         else
587                                 serverid_ok = true;
588                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
589                                 sizeof(struct dhcpv6_auth_reconfigure)) {
590                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
591                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
592                                 continue;
593
594                         md5_state_t md5;
595                         uint8_t serverhash[16], secretbytes[16], hash[16];
596                         memcpy(serverhash, r->key, sizeof(serverhash));
597                         memset(r->key, 0, sizeof(r->key));
598                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
599
600                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
601                                 secretbytes[i] ^= 0x36;
602
603                         md5_init(&md5);
604                         md5_append(&md5, secretbytes, sizeof(secretbytes));
605                         md5_append(&md5, buf, len);
606                         md5_finish(&md5, hash);
607
608                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
609                                 secretbytes[i] ^= 0x36;
610                                 secretbytes[i] ^= 0x5c;
611                         }
612
613                         md5_init(&md5);
614                         md5_append(&md5, secretbytes, sizeof(secretbytes));
615                         md5_append(&md5, hash, 16);
616                         md5_finish(&md5, hash);
617
618                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
619                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
620                         rcmsg = odata[0];
621                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
622                         ia_present = true;
623                         if (olen < sizeof(struct dhcpv6_ia_hdr))
624                                 options_valid = false;
625                 }
626                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
627                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
628                         // Options are not allowed on global level
629                         options_valid = false;
630                 }
631         }
632
633         if (!options_valid)
634                 return false;
635
636         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
637                 return false;
638
639         if (rep->msg_type == DHCPV6_MSG_RECONF) {
640                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
641                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
642                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
643                         return false;
644         }
645
646         return clientid_ok && serverid_ok;
647 }
648
649
650 int dhcpv6_poll_reconfigure(void)
651 {
652         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
653         if (ret != -1)
654                 ret = dhcpv6_request(ret);
655
656         return ret;
657 }
658
659
660 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
661                 const void *opt, const void *end)
662 {
663         uint16_t otype, olen;
664         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
665         dhcpv6_for_each_option(opt, end, otype, olen, odata)
666                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
667                                 odata[0] == DHCPV6_MSG_RENEW ||
668                                 odata[0] == DHCPV6_MSG_INFO_REQ))
669                         msg = odata[0];
670
671         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
672         return msg;
673 }
674
675
676 // Collect all advertised servers
677 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
678                 const void *opt, const void *end)
679 {
680         uint16_t olen, otype;
681         uint8_t *odata, pref = 0;
682         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
683                                         IN6ADDR_ANY_INIT, NULL, NULL, 0, 0};
684         bool have_na = false;
685         int have_pd = 0;
686
687         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
688                 if (orig == DHCPV6_MSG_SOLICIT &&
689                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
690                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
691                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
692                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
693                 }
694
695                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
696                         memcpy(cand.duid, odata, olen);
697                         cand.duid_len = olen;
698                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
699                         int error = ((int)odata[0] << 8 | (int)odata[1]);
700
701                         switch (error) {
702                         case DHCPV6_NoPrefixAvail:
703                                 // Status code on global level
704                                 if (pd_mode == IA_MODE_FORCE)
705                                         return -1;
706                                 cand.preference -= 2000;
707                                 break;
708
709                         case DHCPV6_NoAddrsAvail:
710                                 // Status code on global level
711                                 if (na_mode == IA_MODE_FORCE)
712                                         return -1;
713                                 break;
714
715                         default :
716                                 break;
717                         }
718                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
719                                 cand.preference >= 0) {
720                         cand.preference = pref = odata[0];
721                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
722                         cand.server_addr = *(struct in6_addr *)odata;
723                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
724                         cand.wants_reconfigure = true;
725                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
726                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
727                         uint8_t *oend = odata + olen, *d;
728                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
729                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
730                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
731                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
732                                         have_pd = p->prefix;
733                                 }
734                         }
735                 } else if (otype == DHCPV6_OPT_IA_NA) {
736                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
737                         uint8_t *oend = odata + olen, *d;
738                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
739                                 if (otype == DHCPV6_OPT_IA_ADDR)
740                                         have_na = true;
741                 }
742         }
743
744         if ((!have_na && na_mode == IA_MODE_FORCE) ||
745                         (!have_pd && pd_mode == IA_MODE_FORCE))
746                 return -1;
747
748         if (na_mode != IA_MODE_NONE && !have_na) {
749                 cand.has_noaddravail = true;
750                 cand.preference -= 1000;
751         }
752
753         if (pd_mode != IA_MODE_NONE) {
754                 if (have_pd)
755                         cand.preference += 2000 + (128 - have_pd);
756                 else
757                         cand.preference -= 2000;
758         }
759
760         if (cand.duid_len > 0) {
761                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
762                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
763                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
764         }
765
766         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
767 }
768
769
770 static int dhcpv6_commit_advert(void)
771 {
772         size_t cand_len;
773         struct dhcpv6_server_cand *c = NULL, *cand =
774                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
775
776         bool retry = false;
777         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
778                 if (cand[i].has_noaddravail)
779                         retry = true; // We want to try again
780
781                 if (!c || c->preference < cand[i].preference)
782                         c = &cand[i];
783         }
784
785         if (retry && na_mode == IA_MODE_TRY) {
786                 // We give it a second try without the IA_NA
787                 na_mode = IA_MODE_NONE;
788                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
789         }
790
791         if (c) {
792                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
793                                 htons(c->duid_len)};
794                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
795                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
796                 accept_reconfig = c->wants_reconfigure;
797                 server_addr = c->server_addr;
798                 if (c->ia_na_len)
799                         odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
800                 if (c->ia_pd_len)
801                         odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
802         }
803
804         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
805                 free(cand[i].ia_na);
806                 free(cand[i].ia_pd);
807         }
808         odhcp6c_clear_state(STATE_SERVER_CAND);
809
810         if (!c)
811                 return -1;
812         else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
813                 return DHCPV6_STATEFUL;
814         else
815                 return DHCPV6_STATELESS;
816 }
817
818
819 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
820                 const void *opt, const void *end)
821 {
822         dhcpv6_handle_advert(orig, rc, opt, end);
823         if (dhcpv6_commit_advert() < 0)
824                 return -1;
825
826         return dhcpv6_handle_reply(orig, rc, opt, end);
827 }
828
829
830 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
831                 const void *opt, const void *end)
832 {
833         uint8_t *odata;
834         uint16_t otype, olen;
835         uint32_t refresh = UINT32_MAX;
836         int ret = 1;
837         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
838
839         odhcp6c_expire();
840
841         if (orig == DHCPV6_MSG_UNKNOWN) {
842                 static time_t last_update = 0;
843                 time_t now = odhcp6c_get_milli_time() / 1000;
844
845                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
846                 last_update = now;
847
848                 t1 -= elapsed;
849                 t2 -= elapsed;
850                 t3 -= elapsed;
851
852                 if (t1 < 0)
853                         t1 = 0;
854
855                 if (t2 < 0)
856                         t2 = 0;
857
858                 if (t3 < 0)
859                         t3 = 0;
860         }
861
862         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
863                 // Delete NA and PD we have in the state from the Advert
864                 odhcp6c_clear_state(STATE_IA_NA);
865                 odhcp6c_clear_state(STATE_IA_PD);
866         }
867
868         if (opt) {
869                 odhcp6c_clear_state(STATE_DNS);
870                 odhcp6c_clear_state(STATE_SEARCH);
871                 odhcp6c_clear_state(STATE_SNTP_IP);
872                 odhcp6c_clear_state(STATE_SNTP_FQDN);
873                 odhcp6c_clear_state(STATE_SIP_IP);
874                 odhcp6c_clear_state(STATE_SIP_FQDN);
875                 odhcp6c_clear_state(STATE_AFTR_NAME);
876         }
877
878         // Parse and find all matching IAs
879         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
880                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
881                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
882                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
883
884                         // Test ID
885                         if (ia_hdr->iaid != 1)
886                                 continue;
887
888                         uint16_t code = DHCPV6_Success;
889                         uint16_t stype, slen;
890                         uint8_t *sdata;
891                         // Get and handle status code
892                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
893                                         stype, slen, sdata) {
894                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
895                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
896                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
897
898                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
899
900                                         if (code == DHCPV6_Success)
901                                                 continue;
902
903                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
904                                                 code, mdata, mlen, handled_status_codes, &ret);
905
906
907                                         if (ret > 0)
908                                                 return ret;
909                                         break;
910                                 }
911                         }
912
913                         if (code != DHCPV6_Success)
914                                 continue;
915
916                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
917                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
918                         server_addr = *(struct in6_addr *)odata;
919                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
920                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
921                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
922                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
923
924                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
925                 }
926                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
927                         if (olen % 16 == 0)
928                                 odhcp6c_add_state(STATE_DNS, odata, olen);
929                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
930                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
931                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
932                         uint16_t stype, slen;
933                         uint8_t *sdata;
934                         // Test status and bail if error
935                         dhcpv6_for_each_option(odata, odata + olen,
936                                         stype, slen, sdata) {
937                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
938                                                 stype == NTP_SRV_ADDR))
939                                         odhcp6c_add_state(STATE_SNTP_IP,
940                                                         sdata, slen);
941                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
942                                         odhcp6c_add_state(STATE_SNTP_FQDN,
943                                                         sdata, slen);
944                         }
945                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
946                         if (olen == 16)
947                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
948                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
949                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
950                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
951                         refresh = ntohl(*((uint32_t*)odata));
952                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
953                                 sizeof(struct dhcpv6_auth_reconfigure)) {
954                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
955                         if (r->protocol == 3 && r->algorithm == 1 &&
956                                         r->reconf_type == 1)
957                                 memcpy(reconf_key, r->key, sizeof(r->key));
958                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
959                         size_t cur_len;
960                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
961                         if (cur_len == 0)
962                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
963                 } else if (otype != DHCPV6_OPT_CLIENTID &&
964                                 otype != DHCPV6_OPT_SERVERID) {
965                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
966                                         &odata[-4], olen + 4);
967                 }
968         }
969
970         if (orig != DHCPV6_MSG_INFO_REQ) {
971                 // Update refresh timers if no fatal status code was received
972                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
973                         switch (orig) {
974                         case DHCPV6_MSG_RENEW:
975                                 // Send further renews if T1 is not set
976                                 if (!t1)
977                                         ret = -1;
978                                 break;
979                         case DHCPV6_MSG_REBIND:
980                                 // Send further rebinds if T1 and T2 is not set
981                                 if (!t1 && !t2)
982                                         ret = -1;
983                                 break;
984
985                         default :
986                                 break;
987                         }
988                 }
989         }
990         else if (ret > 0)
991                 t1 = refresh;
992
993         return ret;
994 }
995
996
997 static int dhcpv6_parse_ia(void *opt, void *end)
998 {
999         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1000         int parsed_ia = 0;
1001         uint32_t t1, t2;
1002         uint16_t otype, olen;
1003         uint8_t *odata;
1004
1005         t1 = ntohl(ia_hdr->t1);
1006         t2 = ntohl(ia_hdr->t2);
1007
1008         if (t1 > t2)
1009                 return 0;
1010
1011         // Update address IA
1012         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1013                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1014                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1015
1016                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1017                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1018                         if (olen + 4U < sizeof(*prefix))
1019                                 continue;
1020
1021                         entry.valid = ntohl(prefix->valid);
1022                         entry.preferred = ntohl(prefix->preferred);
1023
1024                         if (entry.preferred > entry.valid)
1025                                 continue;
1026
1027                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1028                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1029                         if (entry.t1 > entry.t2)
1030                                 entry.t1 = entry.t2;
1031
1032                         entry.length = prefix->prefix;
1033                         entry.target = prefix->addr;
1034                         uint16_t stype, slen;
1035                         uint8_t *sdata;
1036
1037 #ifdef EXT_PREFIX_CLASS
1038                         // Find prefix class, if any
1039                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1040                                         stype, slen, sdata)
1041                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1042                                         entry.class = sdata[0] << 8 | sdata[1];
1043 #endif
1044
1045                         // Parse PD-exclude
1046                         bool ok = true;
1047                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1048                                         odata + olen, stype, slen, sdata) {
1049                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1050                                         continue;
1051
1052                                 uint8_t elen = sdata[0];
1053                                 if (elen > 64)
1054                                         elen = 64;
1055
1056                                 if (elen <= 32 || elen <= entry.length) {
1057                                         ok = false;
1058                                         continue;
1059                                 }
1060
1061
1062                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1063                                 if (slen <= bytes) {
1064                                         ok = false;
1065                                         continue;
1066                                 }
1067
1068                                 uint32_t exclude = 0;
1069                                 do {
1070                                         exclude = exclude << 8 | sdata[bytes];
1071                                 } while (--bytes);
1072
1073                                 exclude >>= 8 - ((elen - entry.length) % 8);
1074                                 exclude <<= 64 - elen;
1075
1076                                 // Abusing router & priority fields for exclusion
1077                                 entry.router = entry.target;
1078                                 entry.router.s6_addr32[1] |= htonl(exclude);
1079                                 entry.priority = elen;
1080                         }
1081
1082                         if (ok) {
1083                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1084                                 parsed_ia++;
1085                         }
1086
1087                         entry.priority = 0;
1088                         memset(&entry.router, 0, sizeof(entry.router));
1089                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1090                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1091                         if (olen + 4U < sizeof(*addr))
1092                                 continue;
1093
1094                         entry.preferred = ntohl(addr->preferred);
1095                         entry.valid = ntohl(addr->valid);
1096
1097                         if (entry.preferred > entry.valid)
1098                                 continue;
1099
1100                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1101                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1102                         if (entry.t1 > entry.t2)
1103                                 entry.t1 = entry.t2;
1104
1105                         entry.length = 128;
1106                         entry.target = addr->addr;
1107
1108 #ifdef EXT_PREFIX_CLASS
1109                         uint16_t stype, slen;
1110                         uint8_t *sdata;
1111                         // Find prefix class, if any
1112                         dhcpv6_for_each_option(&addr[1], odata + olen,
1113                                         stype, slen, sdata)
1114                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1115                                         entry.class = sdata[0] << 8 | sdata[1];
1116 #endif
1117
1118                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1119                         parsed_ia++;
1120                 }
1121         }
1122         return parsed_ia;
1123 }
1124
1125
1126 static int dhcpv6_calc_refresh_timers(void)
1127 {
1128         struct odhcp6c_entry *e;
1129         size_t ia_na_entries, ia_pd_entries, i;
1130         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1131
1132         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1133         ia_na_entries /= sizeof(*e);
1134         for (i = 0; i < ia_na_entries; i++) {
1135                 if (e[i].t1 < l_t1)
1136                         l_t1 = e[i].t1;
1137
1138                 if (e[i].t2 < l_t2)
1139                         l_t2 = e[i].t2;
1140
1141                 if (e[i].valid > l_t3)
1142                         l_t3 = e[i].valid;
1143         }
1144
1145         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1146         ia_pd_entries /= sizeof(*e);
1147         for (i = 0; i < ia_pd_entries; i++) {
1148                 if (e[i].t1 < l_t1)
1149                         l_t1 = e[i].t1;
1150
1151                 if (e[i].t2 < l_t2)
1152                         l_t2 = e[i].t2;
1153
1154                 if (e[i].valid > l_t3)
1155                         l_t3 = e[i].valid;
1156         }
1157
1158         if (ia_pd_entries || ia_na_entries) {
1159                 t1 = l_t1;
1160                 t2 = l_t2;
1161                 t3 = l_t3;
1162         }
1163
1164         return (int)(ia_pd_entries + ia_na_entries);
1165 }
1166
1167
1168 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1169                 const void *status_msg, const int len)
1170 {
1171         uint8_t buf[len + 3];
1172
1173         memset(buf, 0, sizeof(buf));
1174         if (len) {
1175                 buf[0] = '(';
1176                 memcpy(&buf[1], status_msg, len);
1177                 buf[len + 1] = ')';
1178         }
1179
1180         syslog(LOG_WARNING, "Server returned %s status %i %s",
1181                 scope, code, buf);
1182 }
1183
1184
1185 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1186                 const uint16_t code, const void *status_msg, const int len,
1187                 int *ret)
1188 {
1189         dhcpv6_log_status_code(code, "message", status_msg, len);
1190
1191         switch (code) {
1192         case DHCPV6_UnspecFail:
1193                 // Generic failure
1194                 *ret = 0;
1195                 break;
1196
1197         case DHCPV6_UseMulticast:
1198                 switch(orig) {
1199                 case DHCPV6_MSG_REQUEST:
1200                 case DHCPV6_MSG_RENEW:
1201                 case DHCPV6_MSG_RELEASE:
1202                 case DHCPV6_MSG_DECLINE:
1203                         // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1204                         server_addr = in6addr_any;
1205                         *ret = 0;
1206                         break;
1207                 default:
1208                         break;
1209                 }
1210                 break;
1211
1212         case DHCPV6_NoAddrsAvail:
1213         case DHCPV6_NoPrefixAvail:
1214                 if (orig == DHCPV6_MSG_REQUEST)
1215                         *ret = 0; // Failure
1216                 break;
1217
1218         default:
1219                 break;
1220         }
1221 }
1222
1223
1224 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1225                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1226                 const void *status_msg, const int len,
1227                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1228 {
1229         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1230                 "IA_NA" : "IA_PD", status_msg, len);
1231
1232         switch (code) {
1233         case DHCPV6_NoBinding:
1234                 switch (orig) {
1235                 case DHCPV6_MSG_RENEW:
1236                 case DHCPV6_MSG_REBIND:
1237                         if ((*ret > 0) && !handled_status_codes[code])
1238                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1239                         break;
1240
1241                 default:
1242                         break;
1243                 }
1244                 break;
1245
1246         case DHCPV6_NoAddrsAvail:
1247         case DHCPV6_NoPrefixAvail:
1248                 switch (orig) {
1249                 case DHCPV6_MSG_REQUEST:
1250                         if (*ret != 0)
1251                                 *ret = 0;
1252                         break;
1253                 default:
1254                         break;
1255                 }
1256                 break;
1257
1258         case DHCPV6_NotOnLink:
1259                 // TODO handle not onlink in case of confirm
1260                 break;
1261
1262         default:
1263                 break;
1264         }
1265 }