Support for SOL_MAX_RT and INF_MAX_RT options (RFC7083)
[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 #define DHCPV6_SOL_MAX_RT_MIN 60
47 #define DHCPV6_SOL_MAX_RT_MAX 86400
48 #define DHCPV6_INF_MAX_RT_MIN 60
49 #define DHCPV6_INF_MAX_RT_MAX 86400
50
51 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
52                 const uint8_t transaction[3], enum dhcpv6_msg type,
53                 const struct in6_addr *daddr);
54
55 static int dhcpv6_parse_ia(void *opt, void *end);
56
57 static int dhcpv6_calc_refresh_timers(void);
58 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
59                 const uint16_t code, const void *status_msg, const int len,
60                 int *ret);
61 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
62                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
63                 const void *status_msg, const int len,
64                 bool handled_status_codes[_DHCPV6_Status_Max],
65                 int *ret);
66 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
67 static void dhcpv6_clear_all_server_cand(void);
68
69 static reply_handler dhcpv6_handle_reply;
70 static reply_handler dhcpv6_handle_advert;
71 static reply_handler dhcpv6_handle_rebind_reply;
72 static reply_handler dhcpv6_handle_reconfigure;
73 static int dhcpv6_commit_advert(void);
74
75
76
77 // RFC 3315 - 5.5 Timeout and Delay values
78 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
79         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
80                         dhcpv6_handle_reconfigure, NULL},
81         [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
82                         dhcpv6_handle_advert, dhcpv6_commit_advert},
83         [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
84                         dhcpv6_handle_reply, NULL},
85         [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
86                         dhcpv6_handle_reply, NULL},
87         [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
88                         dhcpv6_handle_rebind_reply, NULL},
89         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
90         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
91         [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
92                         dhcpv6_handle_reply, NULL},
93 };
94
95
96 // Sockets
97 static int sock = -1;
98 static int ifindex = -1;
99 static int64_t t1 = 0, t2 = 0, t3 = 0;
100
101 // IA states
102 static int request_prefix = -1;
103 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
104 static bool accept_reconfig = false;
105 // Server unicast address
106 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
107
108 // Reconfigure key
109 static uint8_t reconf_key[16];
110
111
112 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
113 {
114         request_prefix = request_pd;
115         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
116
117         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
118         if (sock < 0)
119                 return -1;
120
121         // Detect interface
122         struct ifreq ifr;
123         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
124         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
125                 return -1;
126         ifindex = ifr.ifr_ifindex;
127
128         // Create client DUID
129         size_t client_id_len;
130         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
131         if (client_id_len == 0) {
132                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
133                                 DHCPV6_DUID_LLADDR, 0, 1};
134
135                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
136                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
137
138                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
139                 struct ifreq ifs[100], *ifp, *ifend;
140                 struct ifconf ifc;
141                 ifc.ifc_req = ifs;
142                 ifc.ifc_len = sizeof(ifs);
143
144                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
145                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
146                         // If our interface doesn't have an address...
147                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
148                         for (ifp = ifc.ifc_req; ifp < ifend &&
149                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
150                                 memcpy(ifr.ifr_name, ifp->ifr_name,
151                                                 sizeof(ifr.ifr_name));
152                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
153                                         continue;
154
155                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
156                                                 ETHER_ADDR_LEN);
157                         }
158                 }
159
160                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
161         }
162
163         // Create ORO
164         uint16_t oro[] = {
165                         htons(DHCPV6_OPT_SIP_SERVER_D),
166                         htons(DHCPV6_OPT_SIP_SERVER_A),
167                         htons(DHCPV6_OPT_DNS_SERVERS),
168                         htons(DHCPV6_OPT_DNS_DOMAIN),
169                         htons(DHCPV6_OPT_UNICAST),
170                         htons(DHCPV6_OPT_NTP_SERVER),
171                         htons(DHCPV6_OPT_AFTR_NAME),
172                         htons(DHCPV6_OPT_PD_EXCLUDE),
173                         htons(DHCPV6_OPT_SOL_MAX_RT),
174                         htons(DHCPV6_OPT_INF_MAX_RT),
175 #ifdef EXT_PREFIX_CLASS
176                         htons(DHCPV6_OPT_PREFIX_CLASS),
177 #endif
178         };
179         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
180
181         // Configure IPv6-options
182         int val = 1;
183         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
184         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
185         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
186         val = 0;
187         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
188         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
189
190         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
191                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
192         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
193                 return -1;
194
195         return 0;
196 }
197
198
199 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
200 {
201         na_mode = na;
202         pd_mode = pd;
203 }
204
205
206 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
207 {
208         // Build FQDN
209         char fqdn_buf[256];
210         gethostname(fqdn_buf, sizeof(fqdn_buf));
211         struct {
212                 uint16_t type;
213                 uint16_t len;
214                 uint8_t flags;
215                 uint8_t data[256];
216         } fqdn;
217         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
218                         sizeof(fqdn.data), NULL, NULL);
219         fqdn.type = htons(DHCPV6_OPT_FQDN);
220         fqdn.len = htons(fqdn_len - 4);
221         fqdn.flags = 0;
222
223
224         // Build Client ID
225         size_t cl_id_len;
226         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
227
228         // Get Server ID
229         size_t srv_id_len;
230         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
231
232         // Build IA_PDs
233         size_t ia_pd_entries, ia_pd_len = 0;
234         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
235         ia_pd_entries /= sizeof(*e);
236         struct dhcpv6_ia_hdr hdr_ia_pd = {
237                 htons(DHCPV6_OPT_IA_PD),
238                 htons(sizeof(hdr_ia_pd) - 4),
239                 1, 0, 0
240         };
241
242
243         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
244         for (size_t i = 0; i < ia_pd_entries; ++i) {
245                 uint8_t ex_len = 0;
246                 if (e[i].priority > 0)
247                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
248
249                 struct dhcpv6_ia_prefix p = {
250                         .type = htons(DHCPV6_OPT_IA_PREFIX),
251                         .len = htons(sizeof(p) - 4U + ex_len),
252                         .prefix = e[i].length,
253                         .addr = e[i].target
254                 };
255
256                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
257                 ia_pd_len += sizeof(p);
258
259                 if (ex_len) {
260                         ia_pd[ia_pd_len++] = 0;
261                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
262                         ia_pd[ia_pd_len++] = 0;
263                         ia_pd[ia_pd_len++] = ex_len - 4;
264                         ia_pd[ia_pd_len++] = e[i].priority;
265
266                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
267                         excl >>= (64 - e[i].priority);
268                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
269
270                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
271                                 ia_pd[ia_pd_len + i] = excl & 0xff;
272                         ia_pd_len += ex_len - 5;
273                 }
274         }
275
276         struct dhcpv6_ia_prefix pref = {
277                 .type = htons(DHCPV6_OPT_IA_PREFIX),
278                 .len = htons(25), .prefix = request_prefix
279         };
280         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
281                 ia_pd = (uint8_t*)&pref;
282                 ia_pd_len = sizeof(pref);
283         }
284         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
285
286         // Build IA_NAs
287         size_t ia_na_entries, ia_na_len = 0;
288         void *ia_na = NULL;
289         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
290         ia_na_entries /= sizeof(*e);
291
292         struct dhcpv6_ia_hdr hdr_ia_na = {
293                 htons(DHCPV6_OPT_IA_NA),
294                 htons(sizeof(hdr_ia_na) - 4),
295                 1, 0, 0
296         };
297
298         struct dhcpv6_ia_addr pa[ia_na_entries];
299         for (size_t i = 0; i < ia_na_entries; ++i) {
300                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
301                 pa[i].len = htons(sizeof(pa[i]) - 4U);
302                 pa[i].addr = e[i].target;
303                 pa[i].preferred = 0;
304                 pa[i].valid = 0;
305         }
306
307         ia_na = pa;
308         ia_na_len = sizeof(pa);
309         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
310
311         // Reconfigure Accept
312         struct {
313                 uint16_t type;
314                 uint16_t length;
315         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
316
317         // Request Information Refresh
318         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
319
320         // Prepare Header
321         size_t oro_len;
322         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
323         struct {
324                 uint8_t type;
325                 uint8_t trid[3];
326                 uint16_t elapsed_type;
327                 uint16_t elapsed_len;
328                 uint16_t elapsed_value;
329                 uint16_t oro_type;
330                 uint16_t oro_len;
331         } hdr = {
332                 type, {trid[0], trid[1], trid[2]},
333                 htons(DHCPV6_OPT_ELAPSED), htons(2),
334                         htons((ecs > 0xffff) ? 0xffff : ecs),
335                 htons(DHCPV6_OPT_ORO), htons(oro_len),
336         };
337
338         struct iovec iov[] = {
339                 {&hdr, sizeof(hdr)},
340                 {oro, oro_len},
341                 {&oro_refresh, 0},
342                 {cl_id, cl_id_len},
343                 {srv_id, srv_id_len},
344                 {&reconf_accept, sizeof(reconf_accept)},
345                 {&fqdn, fqdn_len},
346                 {&hdr_ia_na, sizeof(hdr_ia_na)},
347                 {ia_na, ia_na_len},
348                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
349                 {ia_pd, ia_pd_len},
350         };
351
352         size_t cnt = ARRAY_SIZE(iov);
353         if (type == DHCPV6_MSG_INFO_REQ) {
354                 cnt = 5;
355                 iov[2].iov_len = sizeof(oro_refresh);
356                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
357         } else if (!request_prefix) {
358                 cnt = 9;
359         }
360
361         // Disable IAs if not used
362         if (type != DHCPV6_MSG_SOLICIT) {
363                 iov[5].iov_len = 0;
364                 if (ia_na_len == 0)
365                         iov[7].iov_len = 0;
366                 if (ia_pd_len == 0)
367                         iov[9].iov_len = 0;
368         }
369
370         if (na_mode == IA_MODE_NONE)
371                 iov[7].iov_len = 0;
372
373         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
374                 0, ALL_DHCPV6_RELAYS, ifindex};
375         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
376
377         switch (type) {
378         case DHCPV6_MSG_REQUEST:
379         case DHCPV6_MSG_RENEW:
380         case DHCPV6_MSG_RELEASE:
381         case DHCPV6_MSG_DECLINE:
382                 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
383                         odhcp6c_addr_in_scope(&server_addr)) {
384                         srv.sin6_addr = server_addr;
385                         if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
386                                 srv.sin6_scope_id = 0;
387                 }
388                 break;
389         default:
390                 break;
391         }
392
393         if (sendmsg(sock, &msg, 0) < 0) {
394                 char in6_str[INET6_ADDRSTRLEN];
395
396                 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
397                         inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
398                                 in6_str, sizeof(in6_str)), strerror(errno));
399         }
400 }
401
402
403 static int64_t dhcpv6_rand_delay(int64_t time)
404 {
405         int random;
406         odhcp6c_random(&random, sizeof(random));
407         return (time * ((int64_t)random % 1000LL)) / 10000LL;
408 }
409
410
411 int dhcpv6_request(enum dhcpv6_msg type)
412 {
413         uint8_t rc = 0;
414         uint64_t timeout = UINT32_MAX;
415         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
416
417         if (retx->delay) {
418                 struct timespec ts = {0, 0};
419                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
420                 nanosleep(&ts, NULL);
421         }
422
423         if (type == DHCPV6_MSG_UNKNOWN)
424                 timeout = t1;
425         else if (type == DHCPV6_MSG_RENEW)
426                 timeout = (t2 > t1) ? t2 - t1 : 0;
427         else if (type == DHCPV6_MSG_REBIND)
428                 timeout = (t3 > t2) ? t3 - t2 : 0;
429
430         if (timeout == 0)
431                 return -1;
432
433         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
434                         retx->name, (unsigned long long)timeout, retx->max_rc);
435
436         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
437
438         // Generate transaction ID
439         uint8_t trid[3] = {0, 0, 0};
440         if (type != DHCPV6_MSG_UNKNOWN)
441                 odhcp6c_random(trid, sizeof(trid));
442         ssize_t len = -1;
443         int64_t rto = 0;
444
445         do {
446                 if (rto == 0) {
447                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
448
449                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
450                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
451                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
452
453                         rto = (retx->init_timeo * 1000 + delay);
454                 }
455                 else
456                         rto = (2 * rto + dhcpv6_rand_delay(rto));
457
458                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
459                         rto = retx->max_timeo * 1000 +
460                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
461
462                 // Calculate end for this round and elapsed time
463                 uint64_t round_end = round_start + rto;
464                 elapsed = round_start - start;
465
466                 // Don't wait too long
467                 if (round_end - start > timeout * 1000)
468                         round_end = timeout * 1000 + start;
469
470                 // Built and send package
471                 if (type != DHCPV6_MSG_UNKNOWN) {
472                         if (type != DHCPV6_MSG_SOLICIT)
473                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
474                                                 retx->name, (unsigned long long)elapsed, rc);
475                         dhcpv6_send(type, trid, elapsed / 10);
476                         rc++;
477                 }
478
479                 // Receive rounds
480                 for (; len < 0 && (round_start < round_end);
481                                 round_start = odhcp6c_get_milli_time()) {
482                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
483                         struct iovec iov = {buf, sizeof(buf)};
484                         struct msghdr msg = {NULL, 0, &iov, 1,
485                                         cmsg_buf, sizeof(cmsg_buf), 0};
486                         struct in6_pktinfo *pktinfo = NULL;
487
488                         // Check for pending signal
489                         if (odhcp6c_signal_process())
490                                 return -1;
491
492                         // Set timeout for receiving
493                         uint64_t t = round_end - round_start;
494                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
495                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
496                                         &timeout, sizeof(timeout));
497
498                         // Receive cycle
499                         len = recvmsg(sock, &msg, 0);
500                         if (len < 0)
501                                 continue;
502
503                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
504                                 ch = CMSG_NXTHDR(&msg, ch)) {
505                                 if (ch->cmsg_level == SOL_IPV6 &&
506                                         ch->cmsg_type == IPV6_PKTINFO) {
507                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
508                                         break;
509                                 }
510                         }
511
512                         if (pktinfo == NULL) {
513                                 len = -1;
514                                 continue;
515                         }
516
517                         if (!dhcpv6_response_is_valid(buf, len, trid,
518                                                         type, &pktinfo->ipi6_addr)) {
519                                 len = -1;
520                                 continue;
521                         }
522
523                         uint8_t *opt = &buf[4];
524                         uint8_t *opt_end = opt + len - 4;
525
526                         round_start = odhcp6c_get_milli_time();
527                         elapsed = round_start - start;
528                         syslog(LOG_NOTICE, "Got a valid reply after "
529                                         "%llums", (unsigned long long)elapsed);
530
531                         if (retx->handler_reply)
532                                 len = retx->handler_reply(type, rc, opt, opt_end);
533
534                         if (len > 0 && round_end - round_start > 1000)
535                                 round_end = 1000 + round_start;
536                 }
537
538                 // Allow
539                 if (retx->handler_finish)
540                         len = retx->handler_finish();
541         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
542
543         return len;
544 }
545
546 // Message validation checks according to RFC3315 chapter 15
547 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
548                 const uint8_t transaction[3], enum dhcpv6_msg type,
549                 const struct in6_addr *daddr)
550 {
551         const struct dhcpv6_header *rep = buf;
552         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
553                         transaction, sizeof(rep->tr_id)))
554                 return false; // Invalid reply
555
556         if (type == DHCPV6_MSG_SOLICIT) {
557                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
558                                 rep->msg_type != DHCPV6_MSG_REPLY)
559                         return false;
560         } else if (type == DHCPV6_MSG_UNKNOWN) {
561                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
562                         return false;
563         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
564                 return false;
565         }
566
567         uint8_t *end = ((uint8_t*)buf) + len, *odata,
568                 rcmsg = DHCPV6_MSG_UNKNOWN;
569         uint16_t otype, olen;
570         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
571                 ia_present = false, options_valid = true;
572
573         size_t client_id_len, server_id_len;
574         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
575         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
576
577         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
578                 if (otype == DHCPV6_OPT_CLIENTID) {
579                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
580                                         &odata[-4], client_id, client_id_len);
581                 } else if (otype == DHCPV6_OPT_SERVERID) {
582                         if (server_id_len)
583                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
584                                                 &odata[-4], server_id, server_id_len);
585                         else
586                                 serverid_ok = true;
587                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
588                                 sizeof(struct dhcpv6_auth_reconfigure)) {
589                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
590                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
591                                 continue;
592
593                         md5_state_t md5;
594                         uint8_t serverhash[16], secretbytes[16], hash[16];
595                         memcpy(serverhash, r->key, sizeof(serverhash));
596                         memset(r->key, 0, sizeof(r->key));
597                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
598
599                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
600                                 secretbytes[i] ^= 0x36;
601
602                         md5_init(&md5);
603                         md5_append(&md5, secretbytes, sizeof(secretbytes));
604                         md5_append(&md5, buf, len);
605                         md5_finish(&md5, hash);
606
607                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
608                                 secretbytes[i] ^= 0x36;
609                                 secretbytes[i] ^= 0x5c;
610                         }
611
612                         md5_init(&md5);
613                         md5_append(&md5, secretbytes, sizeof(secretbytes));
614                         md5_append(&md5, hash, 16);
615                         md5_finish(&md5, hash);
616
617                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
618                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
619                         rcmsg = odata[0];
620                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
621                         ia_present = true;
622                         if (olen < sizeof(struct dhcpv6_ia_hdr))
623                                 options_valid = false;
624                 }
625                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
626                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
627                         // Options are not allowed on global level
628                         options_valid = false;
629                 }
630         }
631
632         if (!options_valid || ((odata + olen) > end))
633                 return false;
634
635         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
636                 return false;
637
638         if (rep->msg_type == DHCPV6_MSG_RECONF) {
639                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
640                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
641                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
642                         return false;
643         }
644
645         return clientid_ok && serverid_ok;
646 }
647
648
649 int dhcpv6_poll_reconfigure(void)
650 {
651         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
652         if (ret != -1)
653                 ret = dhcpv6_request(ret);
654
655         return ret;
656 }
657
658
659 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
660                 const void *opt, const void *end)
661 {
662         uint16_t otype, olen;
663         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
664         dhcpv6_for_each_option(opt, end, otype, olen, odata)
665                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
666                                 odata[0] == DHCPV6_MSG_RENEW ||
667                                 odata[0] == DHCPV6_MSG_INFO_REQ))
668                         msg = odata[0];
669
670         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
671         return msg;
672 }
673
674
675 // Collect all advertised servers
676 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
677                 const void *opt, const void *end)
678 {
679         uint16_t olen, otype;
680         uint8_t *odata, pref = 0;
681         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
682                                         IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT, 
683                                         DHCPV6_INF_MAX_RT, 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                                 cand.preference -= 2000;
705                                 break;
706
707                         default :
708                                 break;
709                         }
710                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
711                                 cand.preference >= 0) {
712                         cand.preference = pref = odata[0];
713                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
714                         cand.server_addr = *(struct in6_addr *)odata;
715                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
716                         cand.wants_reconfigure = true;
717                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
718                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
719                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN && 
720                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
721                                 cand.sol_max_rt = sol_max_rt;
722                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
723                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
724                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN && 
725                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
726                                 cand.inf_max_rt = inf_max_rt;
727                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
728                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
729                         uint8_t *oend = odata + olen, *d;
730                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
731                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
732                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
733                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
734                                         have_pd = p->prefix;
735                                 }
736                         }
737                 } else if (otype == DHCPV6_OPT_IA_NA) {
738                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
739                         uint8_t *oend = odata + olen, *d;
740                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
741                                 if (otype == DHCPV6_OPT_IA_ADDR)
742                                         have_na = true;
743                 }
744         }
745
746         if ((!have_na && na_mode == IA_MODE_FORCE) ||
747                         (!have_pd && pd_mode == IA_MODE_FORCE)) {
748                 /* 
749                  * RFC7083 states to process the SOL_MAX_RT and 
750                  * INF_MAX_RT options even if the DHCPv6 server
751                  * did not propose any IA_NA and/or IA_PD
752                  */
753                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
754                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
755                 return -1;
756         }
757
758         if (na_mode != IA_MODE_NONE && !have_na) {
759                 cand.has_noaddravail = true;
760                 cand.preference -= 1000;
761         }
762
763         if (pd_mode != IA_MODE_NONE) {
764                 if (have_pd)
765                         cand.preference += 2000 + (128 - have_pd);
766                 else
767                         cand.preference -= 2000;
768         }
769
770         if (cand.duid_len > 0) {
771                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
772                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
773                 dhcpv6_add_server_cand(&cand);
774         }
775
776         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
777 }
778
779
780 static int dhcpv6_commit_advert(void)
781 {
782         return dhcpv6_promote_server_cand();
783 }
784
785
786 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
787                 const void *opt, const void *end)
788 {
789         dhcpv6_handle_advert(orig, rc, opt, end);
790         if (dhcpv6_commit_advert() < 0)
791                 return -1;
792
793         return dhcpv6_handle_reply(orig, rc, opt, end);
794 }
795
796
797 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
798                 const void *opt, const void *end)
799 {
800         uint8_t *odata;
801         uint16_t otype, olen;
802         uint32_t refresh = UINT32_MAX;
803         int ret = 1;
804         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
805
806         odhcp6c_expire();
807
808         if (orig == DHCPV6_MSG_UNKNOWN) {
809                 static time_t last_update = 0;
810                 time_t now = odhcp6c_get_milli_time() / 1000;
811
812                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
813                 last_update = now;
814
815                 t1 -= elapsed;
816                 t2 -= elapsed;
817                 t3 -= elapsed;
818
819                 if (t1 < 0)
820                         t1 = 0;
821
822                 if (t2 < 0)
823                         t2 = 0;
824
825                 if (t3 < 0)
826                         t3 = 0;
827         }
828
829         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
830                 // Delete NA and PD we have in the state from the Advert
831                 odhcp6c_clear_state(STATE_IA_NA);
832                 odhcp6c_clear_state(STATE_IA_PD);
833         }
834
835         if (opt) {
836                 odhcp6c_clear_state(STATE_DNS);
837                 odhcp6c_clear_state(STATE_SEARCH);
838                 odhcp6c_clear_state(STATE_SNTP_IP);
839                 odhcp6c_clear_state(STATE_SNTP_FQDN);
840                 odhcp6c_clear_state(STATE_SIP_IP);
841                 odhcp6c_clear_state(STATE_SIP_FQDN);
842                 odhcp6c_clear_state(STATE_AFTR_NAME);
843         }
844
845         // Parse and find all matching IAs
846         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
847                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
848                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
849                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
850
851                         // Test ID
852                         if (ia_hdr->iaid != 1)
853                                 continue;
854
855                         uint16_t code = DHCPV6_Success;
856                         uint16_t stype, slen;
857                         uint8_t *sdata;
858                         // Get and handle status code
859                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
860                                         stype, slen, sdata) {
861                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
862                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
863                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
864
865                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
866
867                                         if (code == DHCPV6_Success)
868                                                 continue;
869
870                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
871                                                 code, mdata, mlen, handled_status_codes, &ret);
872
873
874                                         if (ret > 0)
875                                                 return ret;
876                                         break;
877                                 }
878                         }
879
880                         if (code != DHCPV6_Success)
881                                 continue;
882
883                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
884                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
885                         server_addr = *(struct in6_addr *)odata;
886                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
887                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
888                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
889                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
890
891                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
892                 }
893                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
894                         if (olen % 16 == 0)
895                                 odhcp6c_add_state(STATE_DNS, odata, olen);
896                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
897                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
898                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
899                         uint16_t stype, slen;
900                         uint8_t *sdata;
901                         // Test status and bail if error
902                         dhcpv6_for_each_option(odata, odata + olen,
903                                         stype, slen, sdata) {
904                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
905                                                 stype == NTP_SRV_ADDR))
906                                         odhcp6c_add_state(STATE_SNTP_IP,
907                                                         sdata, slen);
908                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
909                                         odhcp6c_add_state(STATE_SNTP_FQDN,
910                                                         sdata, slen);
911                         }
912                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
913                         if (olen == 16)
914                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
915                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
916                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
917                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
918                         refresh = ntohl(*((uint32_t*)odata));
919                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
920                                 sizeof(struct dhcpv6_auth_reconfigure)) {
921                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
922                         if (r->protocol == 3 && r->algorithm == 1 &&
923                                         r->reconf_type == 1)
924                                 memcpy(reconf_key, r->key, sizeof(r->key));
925                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
926                         size_t cur_len;
927                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
928                         if (cur_len == 0)
929                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
930                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
931                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
932                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN && 
933                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
934                                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
935                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
936                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
937                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN && 
938                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
939                                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
940                 }else if (otype != DHCPV6_OPT_CLIENTID &&
941                                 otype != DHCPV6_OPT_SERVERID) {
942                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
943                                         &odata[-4], olen + 4);
944                 }
945         }
946
947         if (orig != DHCPV6_MSG_INFO_REQ) {
948                 // Update refresh timers if no fatal status code was received
949                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
950                         switch (orig) {
951                         case DHCPV6_MSG_RENEW:
952                                 // Send further renews if T1 is not set
953                                 if (!t1)
954                                         ret = -1;
955                                 break;
956                         case DHCPV6_MSG_REBIND:
957                                 // Send further rebinds if T1 and T2 is not set
958                                 if (!t1 && !t2)
959                                         ret = -1;
960                                 break;
961
962                         case DHCPV6_MSG_REQUEST:
963                                 // All server candidates can be cleared if not yet bound
964                                 if (!odhcp6c_is_bound())
965                                         dhcpv6_clear_all_server_cand();
966
967                         default :
968                                 break;
969                         }
970                 }
971         }
972         else if (ret > 0) {
973                 // All server candidates can be cleared if not yet bound
974                 if (!odhcp6c_is_bound())
975                         dhcpv6_clear_all_server_cand();
976
977                 t1 = refresh;
978         }
979
980         return ret;
981 }
982
983
984 static int dhcpv6_parse_ia(void *opt, void *end)
985 {
986         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
987         int parsed_ia = 0;
988         uint32_t t1, t2;
989         uint16_t otype, olen;
990         uint8_t *odata;
991
992         t1 = ntohl(ia_hdr->t1);
993         t2 = ntohl(ia_hdr->t2);
994
995         if (t1 > t2)
996                 return 0;
997
998         // Update address IA
999         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1000                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1001                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1002
1003                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1004                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1005                         if (olen + 4U < sizeof(*prefix))
1006                                 continue;
1007
1008                         entry.valid = ntohl(prefix->valid);
1009                         entry.preferred = ntohl(prefix->preferred);
1010
1011                         if (entry.preferred > entry.valid)
1012                                 continue;
1013
1014                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1015                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1016                         if (entry.t1 > entry.t2)
1017                                 entry.t1 = entry.t2;
1018
1019                         entry.length = prefix->prefix;
1020                         entry.target = prefix->addr;
1021                         uint16_t stype, slen;
1022                         uint8_t *sdata;
1023
1024 #ifdef EXT_PREFIX_CLASS
1025                         // Find prefix class, if any
1026                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1027                                         stype, slen, sdata)
1028                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1029                                         entry.class = sdata[0] << 8 | sdata[1];
1030 #endif
1031
1032                         // Parse PD-exclude
1033                         bool ok = true;
1034                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1035                                         odata + olen, stype, slen, sdata) {
1036                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1037                                         continue;
1038
1039                                 uint8_t elen = sdata[0];
1040                                 if (elen > 64)
1041                                         elen = 64;
1042
1043                                 if (elen <= 32 || elen <= entry.length) {
1044                                         ok = false;
1045                                         continue;
1046                                 }
1047
1048
1049                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1050                                 if (slen <= bytes) {
1051                                         ok = false;
1052                                         continue;
1053                                 }
1054
1055                                 uint32_t exclude = 0;
1056                                 do {
1057                                         exclude = exclude << 8 | sdata[bytes];
1058                                 } while (--bytes);
1059
1060                                 exclude >>= 8 - ((elen - entry.length) % 8);
1061                                 exclude <<= 64 - elen;
1062
1063                                 // Abusing router & priority fields for exclusion
1064                                 entry.router = entry.target;
1065                                 entry.router.s6_addr32[1] |= htonl(exclude);
1066                                 entry.priority = elen;
1067                         }
1068
1069                         if (ok) {
1070                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1071                                 parsed_ia++;
1072                         }
1073
1074                         entry.priority = 0;
1075                         memset(&entry.router, 0, sizeof(entry.router));
1076                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1077                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1078                         if (olen + 4U < sizeof(*addr))
1079                                 continue;
1080
1081                         entry.preferred = ntohl(addr->preferred);
1082                         entry.valid = ntohl(addr->valid);
1083
1084                         if (entry.preferred > entry.valid)
1085                                 continue;
1086
1087                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1088                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1089                         if (entry.t1 > entry.t2)
1090                                 entry.t1 = entry.t2;
1091
1092                         entry.length = 128;
1093                         entry.target = addr->addr;
1094
1095 #ifdef EXT_PREFIX_CLASS
1096                         uint16_t stype, slen;
1097                         uint8_t *sdata;
1098                         // Find prefix class, if any
1099                         dhcpv6_for_each_option(&addr[1], odata + olen,
1100                                         stype, slen, sdata)
1101                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1102                                         entry.class = sdata[0] << 8 | sdata[1];
1103 #endif
1104
1105                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1106                         parsed_ia++;
1107                 }
1108         }
1109         return parsed_ia;
1110 }
1111
1112
1113 static int dhcpv6_calc_refresh_timers(void)
1114 {
1115         struct odhcp6c_entry *e;
1116         size_t ia_na_entries, ia_pd_entries, i;
1117         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1118
1119         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1120         ia_na_entries /= sizeof(*e);
1121         for (i = 0; i < ia_na_entries; i++) {
1122                 if (e[i].t1 < l_t1)
1123                         l_t1 = e[i].t1;
1124
1125                 if (e[i].t2 < l_t2)
1126                         l_t2 = e[i].t2;
1127
1128                 if (e[i].valid > l_t3)
1129                         l_t3 = e[i].valid;
1130         }
1131
1132         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1133         ia_pd_entries /= sizeof(*e);
1134         for (i = 0; i < ia_pd_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         if (ia_pd_entries || ia_na_entries) {
1146                 t1 = l_t1;
1147                 t2 = l_t2;
1148                 t3 = l_t3;
1149         }
1150
1151         return (int)(ia_pd_entries + ia_na_entries);
1152 }
1153
1154
1155 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1156                 const void *status_msg, const int len)
1157 {
1158         uint8_t buf[len + 3];
1159
1160         memset(buf, 0, sizeof(buf));
1161         if (len) {
1162                 buf[0] = '(';
1163                 memcpy(&buf[1], status_msg, len);
1164                 buf[len + 1] = ')';
1165         }
1166
1167         syslog(LOG_WARNING, "Server returned %s status %i %s",
1168                 scope, code, buf);
1169 }
1170
1171
1172 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1173                 const uint16_t code, const void *status_msg, const int len,
1174                 int *ret)
1175 {
1176         dhcpv6_log_status_code(code, "message", status_msg, len);
1177
1178         switch (code) {
1179         case DHCPV6_UnspecFail:
1180                 // Generic failure
1181                 *ret = 0;
1182                 break;
1183
1184         case DHCPV6_UseMulticast:
1185                 switch(orig) {
1186                 case DHCPV6_MSG_REQUEST:
1187                 case DHCPV6_MSG_RENEW:
1188                 case DHCPV6_MSG_RELEASE:
1189                 case DHCPV6_MSG_DECLINE:
1190                         // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1191                         server_addr = in6addr_any;
1192                         *ret = 0;
1193                         break;
1194                 default:
1195                         break;
1196                 }
1197                 break;
1198
1199         case DHCPV6_NoAddrsAvail:
1200         case DHCPV6_NoPrefixAvail:
1201                 if (orig == DHCPV6_MSG_REQUEST)
1202                         *ret = 0; // Failure
1203                 break;
1204
1205         default:
1206                 break;
1207         }
1208 }
1209
1210
1211 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1212                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1213                 const void *status_msg, const int len,
1214                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1215 {
1216         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1217                 "IA_NA" : "IA_PD", status_msg, len);
1218
1219         switch (code) {
1220         case DHCPV6_NoBinding:
1221                 switch (orig) {
1222                 case DHCPV6_MSG_RENEW:
1223                 case DHCPV6_MSG_REBIND:
1224                         if ((*ret > 0) && !handled_status_codes[code])
1225                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1226                         break;
1227
1228                 default:
1229                         break;
1230                 }
1231                 break;
1232
1233         case DHCPV6_NoAddrsAvail:
1234         case DHCPV6_NoPrefixAvail:
1235                 switch (orig) {
1236                 case DHCPV6_MSG_REQUEST:
1237                         if (*ret != 0)
1238                                 *ret = 0;
1239                         break;
1240                 default:
1241                         break;
1242                 }
1243                 break;
1244
1245         case DHCPV6_NotOnLink:
1246                 // TODO handle not onlink in case of confirm
1247                 break;
1248
1249         default:
1250                 break;
1251         }
1252 }
1253
1254 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1255 {
1256         size_t cand_len, i;
1257         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1258
1259         // Remove identical duid server candidate
1260         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1261                 if (cand->duid_len == c[i].duid_len &&
1262                         !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1263                         free(c[i].ia_na);
1264                         free(c[i].ia_pd);
1265                         odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1266                         break;
1267                 }
1268         }
1269
1270         for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1271                 i < cand_len / sizeof(*c); ++i) {
1272                 if (c[i].preference < cand->preference)
1273                         break;
1274         }
1275
1276         odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1277 }
1278
1279 static void dhcpv6_clear_all_server_cand(void)
1280 {
1281         size_t cand_len, i;
1282         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1283
1284         // Server candidates need deep delete for IA_NA/IA_PD
1285         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1286                 if (c[i].ia_na)
1287                         free(c[i].ia_na);
1288                 if (c[i].ia_pd)
1289                         free(c[i].ia_pd);
1290         }
1291         odhcp6c_clear_state(STATE_SERVER_CAND);
1292 }
1293
1294 int dhcpv6_promote_server_cand(void)
1295 {
1296         size_t cand_len;
1297         struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1298         uint16_t hdr[2];
1299         int ret = DHCPV6_STATELESS;
1300
1301         // Clear lingering candidate state info
1302         odhcp6c_clear_state(STATE_SERVER_ID);
1303         odhcp6c_clear_state(STATE_IA_NA);
1304         odhcp6c_clear_state(STATE_IA_PD);
1305
1306         if (!cand_len)
1307                 return -1;
1308
1309         if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1310                 na_mode = IA_MODE_NONE;
1311
1312                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1313                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1314
1315                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1316         }
1317
1318         hdr[0] = htons(DHCPV6_OPT_SERVERID);
1319         hdr[1] = htons(cand->duid_len);
1320         odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1321         odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1322         accept_reconfig = cand->wants_reconfigure;
1323         if (cand->ia_na_len) {
1324                 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1325                 free(cand->ia_na);
1326                 if (na_mode != IA_MODE_NONE)
1327                         ret = DHCPV6_STATEFUL;
1328         }
1329         if (cand->ia_pd_len) {
1330                 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1331                 free(cand->ia_pd);
1332                 if (request_prefix)
1333                         ret = DHCPV6_STATEFUL;
1334         }
1335
1336         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1337         dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1338         
1339         odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1340
1341         return ret;
1342 }