Fix fallout from userclass addition
[odhcp6c.git] / src / dhcpv6.c
1 /**
2  * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License v2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14
15 #include <time.h>
16 #include <fcntl.h>
17 #include <errno.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <limits.h>
21 #include <resolv.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <syslog.h>
25 #include <stdbool.h>
26 #include <sys/time.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30
31 #include <net/if.h>
32 #include <net/ethernet.h>
33
34 #include "odhcp6c.h"
35 #include "md5.h"
36
37
38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
39                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
40 #define DHCPV6_CLIENT_PORT 546
41 #define DHCPV6_SERVER_PORT 547
42 #define DHCPV6_DUID_LLADDR 3
43 #define DHCPV6_REQ_DELAY 1
44
45 #define DHCPV6_SOL_MAX_RT_MIN 60
46 #define DHCPV6_SOL_MAX_RT_MAX 86400
47 #define DHCPV6_INF_MAX_RT_MIN 60
48 #define DHCPV6_INF_MAX_RT_MAX 86400
49
50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
51                 const uint8_t transaction[3], enum dhcpv6_msg type,
52                 const struct in6_addr *daddr);
53
54 static int dhcpv6_parse_ia(void *opt, void *end);
55
56 static int dhcpv6_calc_refresh_timers(void);
57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
58                 const uint16_t code, const void *status_msg, const int len,
59                 int *ret);
60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
61                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
62                 const void *status_msg, const int len,
63                 bool handled_status_codes[_DHCPV6_Status_Max],
64                 int *ret);
65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
66 static void dhcpv6_clear_all_server_cand(void);
67
68 static reply_handler dhcpv6_handle_reply;
69 static reply_handler dhcpv6_handle_advert;
70 static reply_handler dhcpv6_handle_rebind_reply;
71 static reply_handler dhcpv6_handle_reconfigure;
72 static int dhcpv6_commit_advert(void);
73
74
75
76 // RFC 3315 - 5.5 Timeout and Delay values
77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
78         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
79                         dhcpv6_handle_reconfigure, NULL},
80         [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
81                         dhcpv6_handle_advert, dhcpv6_commit_advert},
82         [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
83                         dhcpv6_handle_reply, NULL},
84         [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
85                         dhcpv6_handle_reply, NULL},
86         [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
87                         dhcpv6_handle_rebind_reply, NULL},
88         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
89         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
90         [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
91                         dhcpv6_handle_reply, NULL},
92 };
93
94
95 // Sockets
96 static int sock = -1;
97 static int ifindex = -1;
98 static int64_t t1 = 0, t2 = 0, t3 = 0;
99
100 // IA states
101 static int request_prefix = -1;
102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
103 static bool accept_reconfig = false;
104
105 // Reconfigure key
106 static uint8_t reconf_key[16];
107
108 // client options
109 static unsigned int client_options = 0;
110
111
112 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
113 {
114         client_options = options;
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         if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
165                 uint16_t oro[] = {
166                         htons(DHCPV6_OPT_SIP_SERVER_D),
167                         htons(DHCPV6_OPT_SIP_SERVER_A),
168                         htons(DHCPV6_OPT_DNS_SERVERS),
169                         htons(DHCPV6_OPT_DNS_DOMAIN),
170                         htons(DHCPV6_OPT_SNTP_SERVERS),
171                         htons(DHCPV6_OPT_NTP_SERVER),
172                         htons(DHCPV6_OPT_AFTR_NAME),
173                         htons(DHCPV6_OPT_PD_EXCLUDE),
174                         htons(DHCPV6_OPT_SOL_MAX_RT),
175                         htons(DHCPV6_OPT_INF_MAX_RT),
176 #ifdef EXT_PREFIX_CLASS
177                         htons(DHCPV6_OPT_PREFIX_CLASS),
178 #endif
179                 };
180                 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
181         }
182
183         // Configure IPv6-options
184         int val = 1;
185         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
186         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
187         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
188         val = 0;
189         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
190         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
191
192         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
193                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
194         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
195                 return -1;
196
197         return 0;
198 }
199
200
201 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
202 {
203         na_mode = na;
204         pd_mode = pd;
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         uint8_t *ia_pd;
236
237         if (type == DHCPV6_MSG_SOLICIT) {
238                 odhcp6c_clear_state(STATE_IA_PD);
239                 size_t n_prefixes;
240                 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
241                 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
242
243                 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
244
245                 for (size_t i = 0; i < n_prefixes; i++) {
246                         struct dhcpv6_ia_hdr hdr_ia_pd = {
247                                 htons(DHCPV6_OPT_IA_PD),
248                                 htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix)),
249                                 request_prefixes[i].iaid, 0, 0
250                         };
251                         struct dhcpv6_ia_prefix pref = {
252                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
253                                 .len = htons(25), .prefix = request_prefixes[i].length
254                         };
255                         memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
256                         ia_pd_len += sizeof(hdr_ia_pd);
257                         memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref));
258                         ia_pd_len += sizeof(pref);
259                 }
260         } else {
261                 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
262                 ia_pd_entries /= sizeof(*e);
263
264                 // we're too lazy to count our distinct IAIDs,
265                 // so just allocate maximally needed space
266                 ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 +
267                                         sizeof(struct dhcpv6_ia_hdr)));
268
269                 for (size_t i = 0; i < ia_pd_entries; ++i) {
270                         uint32_t iaid = e[i].iaid;
271
272                         // check if this is an unprocessed IAID and skip if not.
273                         int new_iaid = 1;
274                         for (int j = i-1; j >= 0; j--) {
275                                 if (e[j].iaid == iaid) {
276                                         new_iaid = 0;
277                                         break;
278                                 }
279                         }
280
281                         if (!new_iaid)
282                                 continue;
283
284                         // construct header
285                         struct dhcpv6_ia_hdr hdr_ia_pd = {
286                                 htons(DHCPV6_OPT_IA_PD),
287                                 htons(sizeof(hdr_ia_pd) - 4),
288                                 iaid, 0, 0
289                         };
290
291                         memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd));
292                         struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len);
293                         ia_pd_len += sizeof(hdr_ia_pd);
294
295                         for (size_t j = i; j < ia_pd_entries; j++) {
296                                 if (e[j].iaid != iaid)
297                                         continue;
298
299                                 uint8_t ex_len = 0;
300                                 if (e[j].priority > 0)
301                                         ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
302
303                                 struct dhcpv6_ia_prefix p = {
304                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
305                                         .len = htons(sizeof(p) - 4U + ex_len),
306                                         .prefix = e[j].length,
307                                         .addr = e[j].target
308                                 };
309
310                                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
311                                 ia_pd_len += sizeof(p);
312
313                                 if (ex_len) {
314                                         ia_pd[ia_pd_len++] = 0;
315                                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
316                                         ia_pd[ia_pd_len++] = 0;
317                                         ia_pd[ia_pd_len++] = ex_len - 4;
318                                         ia_pd[ia_pd_len++] = e[j].priority;
319
320                                         uint32_t excl = ntohl(e[j].router.s6_addr32[1]);
321                                         excl >>= (64 - e[j].priority);
322                                         excl <<= 8 - ((e[j].priority - e[j].length) % 8);
323
324                                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
325                                                 ia_pd[ia_pd_len + i] = excl & 0xff;
326                                         ia_pd_len += ex_len - 5;
327                                 }
328
329                                 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
330                         }
331                 }
332         }
333
334         if (ia_pd_entries > 0)
335                 request_prefix = 1;
336
337         // Build IA_NAs
338         size_t ia_na_entries, ia_na_len = 0;
339         void *ia_na = NULL;
340         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
341         ia_na_entries /= sizeof(*e);
342
343         struct dhcpv6_ia_hdr hdr_ia_na = {
344                 htons(DHCPV6_OPT_IA_NA),
345                 htons(sizeof(hdr_ia_na) - 4),
346                 1, 0, 0
347         };
348
349         struct dhcpv6_ia_addr pa[ia_na_entries];
350         for (size_t i = 0; i < ia_na_entries; ++i) {
351                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
352                 pa[i].len = htons(sizeof(pa[i]) - 4U);
353                 pa[i].addr = e[i].target;
354                 pa[i].preferred = 0;
355                 pa[i].valid = 0;
356         }
357
358         ia_na = pa;
359         ia_na_len = sizeof(pa);
360         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
361
362         // Reconfigure Accept
363         struct {
364                 uint16_t type;
365                 uint16_t length;
366         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
367
368         // Request Information Refresh
369         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
370
371         // Build vendor-class option
372         size_t vendor_class_len, user_class_len;
373         struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
374         void *user_class = odhcp6c_get_state(STATE_USERCLASS, &user_class_len);
375
376         struct {
377                 uint16_t type;
378                 uint16_t length;
379         } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
380
381         struct {
382                 uint16_t type;
383                 uint16_t length;
384         } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
385
386         // Prepare Header
387         size_t oro_len;
388         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
389         struct {
390                 uint8_t type;
391                 uint8_t trid[3];
392                 uint16_t elapsed_type;
393                 uint16_t elapsed_len;
394                 uint16_t elapsed_value;
395                 uint16_t oro_type;
396                 uint16_t oro_len;
397         } hdr = {
398                 type, {trid[0], trid[1], trid[2]},
399                 htons(DHCPV6_OPT_ELAPSED), htons(2),
400                         htons((ecs > 0xffff) ? 0xffff : ecs),
401                 htons(DHCPV6_OPT_ORO), htons(oro_len),
402         };
403
404         struct iovec iov[] = {
405                 {&hdr, sizeof(hdr)},
406                 {oro, oro_len},
407                 {&oro_refresh, 0},
408                 {cl_id, cl_id_len},
409                 {srv_id, srv_id_len},
410                 {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
411                 {vendor_class, vendor_class_len},
412                 {&user_class_hdr, user_class_len ? sizeof(user_class_hdr) : 0},
413                 {user_class, user_class_len},
414                 {&reconf_accept, sizeof(reconf_accept)},
415                 {&fqdn, fqdn_len},
416                 {&hdr_ia_na, sizeof(hdr_ia_na)},
417                 {ia_na, ia_na_len},
418                 {ia_pd, ia_pd_len},
419         };
420
421         size_t cnt = ARRAY_SIZE(iov);
422         if (type == DHCPV6_MSG_INFO_REQ) {
423                 cnt = 9;
424                 iov[2].iov_len = sizeof(oro_refresh);
425                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
426         } else if (!request_prefix) {
427                 cnt = 13;
428         }
429
430         // Disable IAs if not used
431         if (type != DHCPV6_MSG_SOLICIT) {
432                 iov[9].iov_len = 0;
433                 if (ia_na_len == 0)
434                         iov[11].iov_len = 0;
435         }
436
437         if (na_mode == IA_MODE_NONE)
438                 iov[11].iov_len = 0;
439
440         if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
441                 iov[9].iov_len = 0;
442
443         if (!(client_options & DHCPV6_CLIENT_FQDN))
444                 iov[10].iov_len = 0;
445
446         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
447                 0, ALL_DHCPV6_RELAYS, ifindex};
448         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
449
450         sendmsg(sock, &msg, 0);
451 }
452
453
454 static int64_t dhcpv6_rand_delay(int64_t time)
455 {
456         int random;
457         odhcp6c_random(&random, sizeof(random));
458         return (time * ((int64_t)random % 1000LL)) / 10000LL;
459 }
460
461
462 int dhcpv6_request(enum dhcpv6_msg type)
463 {
464         uint8_t rc = 0;
465         uint64_t timeout = UINT32_MAX;
466         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
467
468         if (retx->delay) {
469                 struct timespec ts = {0, 0};
470                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
471                 nanosleep(&ts, NULL);
472         }
473
474         if (type == DHCPV6_MSG_UNKNOWN)
475                 timeout = t1;
476         else if (type == DHCPV6_MSG_RENEW)
477                 timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0);
478         else if (type == DHCPV6_MSG_REBIND)
479                 timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0);
480
481         if (timeout == 0)
482                 return -1;
483
484         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
485                         retx->name, (unsigned long long)timeout, retx->max_rc);
486
487         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
488
489         // Generate transaction ID
490         uint8_t trid[3] = {0, 0, 0};
491         if (type != DHCPV6_MSG_UNKNOWN)
492                 odhcp6c_random(trid, sizeof(trid));
493         ssize_t len = -1;
494         int64_t rto = 0;
495
496         do {
497                 if (rto == 0) {
498                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
499
500                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
501                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
502                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
503
504                         rto = (retx->init_timeo * 1000 + delay);
505                 }
506                 else
507                         rto = (2 * rto + dhcpv6_rand_delay(rto));
508
509                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
510                         rto = retx->max_timeo * 1000 +
511                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
512
513                 // Calculate end for this round and elapsed time
514                 uint64_t round_end = round_start + rto;
515                 elapsed = round_start - start;
516
517                 // Don't wait too long if timeout differs from infinite
518                 if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000))
519                         round_end = timeout * 1000 + start;
520
521                 // Built and send package
522                 if (type != DHCPV6_MSG_UNKNOWN) {
523                         if (type != DHCPV6_MSG_SOLICIT)
524                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
525                                                 retx->name, (unsigned long long)elapsed, rc);
526                         dhcpv6_send(type, trid, elapsed / 10);
527                         rc++;
528                 }
529
530                 // Receive rounds
531                 for (; len < 0 && (round_start < round_end);
532                                 round_start = odhcp6c_get_milli_time()) {
533                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
534                         struct iovec iov = {buf, sizeof(buf)};
535                         struct msghdr msg = {NULL, 0, &iov, 1,
536                                         cmsg_buf, sizeof(cmsg_buf), 0};
537                         struct in6_pktinfo *pktinfo = NULL;
538
539                         // Check for pending signal
540                         if (odhcp6c_signal_process())
541                                 return -1;
542
543                         // Set timeout for receiving
544                         uint64_t t = round_end - round_start;
545                         struct timeval tv = {t / 1000, (t % 1000) * 1000};
546                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
547                                         &tv, sizeof(tv));
548
549                         // Receive cycle
550                         len = recvmsg(sock, &msg, 0);
551                         if (len < 0)
552                                 continue;
553
554                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
555                                 ch = CMSG_NXTHDR(&msg, ch)) {
556                                 if (ch->cmsg_level == SOL_IPV6 &&
557                                         ch->cmsg_type == IPV6_PKTINFO) {
558                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
559                                         break;
560                                 }
561                         }
562
563                         if (pktinfo == NULL) {
564                                 len = -1;
565                                 continue;
566                         }
567
568                         if (!dhcpv6_response_is_valid(buf, len, trid,
569                                                         type, &pktinfo->ipi6_addr)) {
570                                 len = -1;
571                                 continue;
572                         }
573
574                         uint8_t *opt = &buf[4];
575                         uint8_t *opt_end = opt + len - 4;
576
577                         round_start = odhcp6c_get_milli_time();
578                         elapsed = round_start - start;
579                         syslog(LOG_NOTICE, "Got a valid reply after "
580                                         "%llums", (unsigned long long)elapsed);
581
582                         if (retx->handler_reply)
583                                 len = retx->handler_reply(type, rc, opt, opt_end);
584
585                         if (len > 0 && round_end - round_start > 1000)
586                                 round_end = 1000 + round_start;
587                 }
588
589                 // Allow
590                 if (retx->handler_finish)
591                         len = retx->handler_finish();
592         } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) && 
593                         (!retx->max_rc || rc < retx->max_rc));
594         return len;
595 }
596
597 // Message validation checks according to RFC3315 chapter 15
598 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
599                 const uint8_t transaction[3], enum dhcpv6_msg type,
600                 const struct in6_addr *daddr)
601 {
602         const struct dhcpv6_header *rep = buf;
603         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
604                         transaction, sizeof(rep->tr_id)))
605                 return false; // Invalid reply
606
607         if (type == DHCPV6_MSG_SOLICIT) {
608                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
609                                 rep->msg_type != DHCPV6_MSG_REPLY)
610                         return false;
611         } else if (type == DHCPV6_MSG_UNKNOWN) {
612                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
613                         return false;
614         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
615                 return false;
616         }
617
618         uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
619                 rcmsg = DHCPV6_MSG_UNKNOWN;
620         uint16_t otype, olen = UINT16_MAX;
621         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
622                 ia_present = false, options_valid = true;
623
624         size_t client_id_len, server_id_len;
625         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
626         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
627
628         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
629                 if (otype == DHCPV6_OPT_CLIENTID) {
630                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
631                                         &odata[-4], client_id, client_id_len);
632                 } else if (otype == DHCPV6_OPT_SERVERID) {
633                         if (server_id_len)
634                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
635                                                 &odata[-4], server_id, server_id_len);
636                         else
637                                 serverid_ok = true;
638                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
639                                 sizeof(struct dhcpv6_auth_reconfigure)) {
640                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
641                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
642                                 continue;
643
644                         md5_ctx_t md5;
645                         uint8_t serverhash[16], secretbytes[16], hash[16];
646                         memcpy(serverhash, r->key, sizeof(serverhash));
647                         memset(r->key, 0, sizeof(r->key));
648                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
649
650                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
651                                 secretbytes[i] ^= 0x36;
652
653                         md5_begin(&md5);
654                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
655                         md5_hash(buf, len, &md5);
656                         md5_end(hash, &md5);
657
658                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
659                                 secretbytes[i] ^= 0x36;
660                                 secretbytes[i] ^= 0x5c;
661                         }
662
663                         md5_begin(&md5);
664                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
665                         md5_hash(hash, 16, &md5);
666                         md5_end(hash, &md5);
667
668                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
669                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
670                         rcmsg = odata[0];
671                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
672                         ia_present = true;
673                         if (olen < sizeof(struct dhcpv6_ia_hdr))
674                                 options_valid = false;
675                 }
676                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
677                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
678                         // Options are not allowed on global level
679                         options_valid = false;
680                 }
681         }
682
683         if (!options_valid || ((odata + olen) > end))
684                 return false;
685
686         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
687                 return false;
688
689         if (rep->msg_type == DHCPV6_MSG_RECONF) {
690                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
691                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
692                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
693                         return false;
694         }
695
696         return clientid_ok && serverid_ok;
697 }
698
699
700 int dhcpv6_poll_reconfigure(void)
701 {
702         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
703         if (ret != -1)
704                 ret = dhcpv6_request(ret);
705
706         return ret;
707 }
708
709
710 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
711                 const void *opt, const void *end)
712 {
713         uint16_t otype, olen;
714         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
715         dhcpv6_for_each_option(opt, end, otype, olen, odata)
716                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
717                                 odata[0] == DHCPV6_MSG_RENEW ||
718                                 odata[0] == DHCPV6_MSG_INFO_REQ))
719                         msg = odata[0];
720
721         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
722         return msg;
723 }
724
725
726 // Collect all advertised servers
727 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
728                 const void *opt, const void *end)
729 {
730         uint16_t olen, otype;
731         uint8_t *odata, pref = 0;
732         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
733                                         DHCPV6_SOL_MAX_RT,
734                                         DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
735         bool have_na = false;
736         int have_pd = 0;
737
738         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
739                 if (orig == DHCPV6_MSG_SOLICIT &&
740                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
741                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
742                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
743                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
744                 }
745
746                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
747                         memcpy(cand.duid, odata, olen);
748                         cand.duid_len = olen;
749                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
750                         int error = ((int)odata[0] << 8 | (int)odata[1]);
751
752                         switch (error) {
753                         case DHCPV6_NoPrefixAvail:
754                                 // Status code on global level
755                                 cand.preference -= 2000;
756                                 break;
757
758                         default :
759                                 break;
760                         }
761                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
762                                 cand.preference >= 0) {
763                         cand.preference = pref = odata[0];
764                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
765                         cand.wants_reconfigure = true;
766                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
767                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
768                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
769                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
770                                 cand.sol_max_rt = sol_max_rt;
771                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
772                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
773                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
774                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
775                                 cand.inf_max_rt = inf_max_rt;
776                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
777                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
778                         uint8_t *oend = odata + olen, *d;
779                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
780                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
781                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
782                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
783                                         have_pd = p->prefix;
784                                 }
785                         }
786                 } else if (otype == DHCPV6_OPT_IA_NA) {
787                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
788                         uint8_t *oend = odata + olen, *d;
789                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
790                                 if (otype == DHCPV6_OPT_IA_ADDR)
791                                         have_na = true;
792                 }
793         }
794
795         if ((!have_na && na_mode == IA_MODE_FORCE) ||
796                         (!have_pd && pd_mode == IA_MODE_FORCE)) {
797                 /*
798                  * RFC7083 states to process the SOL_MAX_RT and
799                  * INF_MAX_RT options even if the DHCPv6 server
800                  * did not propose any IA_NA and/or IA_PD
801                  */
802                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
803                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
804                 return -1;
805         }
806
807         if (na_mode != IA_MODE_NONE && !have_na) {
808                 cand.has_noaddravail = true;
809                 cand.preference -= 1000;
810         }
811
812         if (pd_mode != IA_MODE_NONE) {
813                 if (have_pd)
814                         cand.preference += 2000 + (128 - have_pd);
815                 else
816                         cand.preference -= 2000;
817         }
818
819         if (cand.duid_len > 0) {
820                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
821                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
822                 dhcpv6_add_server_cand(&cand);
823         }
824
825         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
826 }
827
828
829 static int dhcpv6_commit_advert(void)
830 {
831         return dhcpv6_promote_server_cand();
832 }
833
834
835 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
836                 const void *opt, const void *end)
837 {
838         dhcpv6_handle_advert(orig, rc, opt, end);
839         if (dhcpv6_commit_advert() < 0)
840                 return -1;
841
842         return dhcpv6_handle_reply(orig, rc, opt, end);
843 }
844
845
846 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
847                 const void *opt, const void *end)
848 {
849         uint8_t *odata;
850         uint16_t otype, olen;
851         uint32_t refresh = UINT32_MAX;
852         int ret = 1;
853         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
854
855         odhcp6c_expire();
856
857         if (orig == DHCPV6_MSG_UNKNOWN) {
858                 static time_t last_update = 0;
859                 time_t now = odhcp6c_get_milli_time() / 1000;
860
861                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
862                 last_update = now;
863
864                 if (t1 != UINT32_MAX)
865                         t1 -= elapsed;
866
867                 if (t2 != UINT32_MAX)
868                         t2 -= elapsed;
869
870                 if (t3 != UINT32_MAX)
871                         t3 -= elapsed;
872
873                 if (t1 < 0)
874                         t1 = 0;
875
876                 if (t2 < 0)
877                         t2 = 0;
878
879                 if (t3 < 0)
880                         t3 = 0;
881         }
882
883         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
884                 // Delete NA and PD we have in the state from the Advert
885                 odhcp6c_clear_state(STATE_IA_NA);
886                 odhcp6c_clear_state(STATE_IA_PD);
887         }
888
889         if (opt) {
890                 odhcp6c_clear_state(STATE_DNS);
891                 odhcp6c_clear_state(STATE_SEARCH);
892                 odhcp6c_clear_state(STATE_SNTP_IP);
893                 odhcp6c_clear_state(STATE_NTP_IP);
894                 odhcp6c_clear_state(STATE_NTP_FQDN);
895                 odhcp6c_clear_state(STATE_SIP_IP);
896                 odhcp6c_clear_state(STATE_SIP_FQDN);
897                 odhcp6c_clear_state(STATE_AFTR_NAME);
898         }
899
900         // Parse and find all matching IAs
901         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
902                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
903                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
904                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
905
906                         // Test ID
907                         if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
908                                 continue;
909
910                         uint16_t code = DHCPV6_Success;
911                         uint16_t stype, slen;
912                         uint8_t *sdata;
913                         // Get and handle status code
914                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
915                                         stype, slen, sdata) {
916                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
917                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
918                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
919
920                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
921
922                                         if (code == DHCPV6_Success)
923                                                 continue;
924
925                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
926                                                 code, mdata, mlen, handled_status_codes, &ret);
927
928
929                                         if (ret > 0)
930                                                 return ret;
931                                         break;
932                                 }
933                         }
934
935                         if (code != DHCPV6_Success)
936                                 continue;
937
938                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
939                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
940                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
941                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
942                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
943
944                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
945                 }
946                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
947                         if (olen % 16 == 0)
948                                 odhcp6c_add_state(STATE_DNS, odata, olen);
949                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
950                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
951                 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
952                         if (olen % 16 == 0)
953                                 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
954                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
955                         uint16_t stype, slen;
956                         uint8_t *sdata;
957                         // Test status and bail if error
958                         dhcpv6_for_each_option(odata, odata + olen,
959                                         stype, slen, sdata) {
960                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
961                                                 stype == NTP_SRV_ADDR))
962                                         odhcp6c_add_state(STATE_NTP_IP,
963                                                         sdata, slen);
964                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
965                                         odhcp6c_add_state(STATE_NTP_FQDN,
966                                                         sdata, slen);
967                         }
968                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
969                         if (olen == 16)
970                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
971                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
972                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
973                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
974                         refresh = ntohl(*((uint32_t*)odata));
975                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
976                                 sizeof(struct dhcpv6_auth_reconfigure)) {
977                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
978                         if (r->protocol == 3 && r->algorithm == 1 &&
979                                         r->reconf_type == 1)
980                                 memcpy(reconf_key, r->key, sizeof(r->key));
981                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
982                         size_t cur_len;
983                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
984                         if (cur_len == 0)
985                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
986                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
987                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
988                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
989                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
990                                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
991                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
992                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
993                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
994                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
995                                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
996                 }else if (otype != DHCPV6_OPT_CLIENTID &&
997                                 otype != DHCPV6_OPT_SERVERID) {
998                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
999                                         &odata[-4], olen + 4);
1000                 }
1001         }
1002
1003         if (orig != DHCPV6_MSG_INFO_REQ) {
1004                 // Update refresh timers if no fatal status code was received
1005                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1006                         switch (orig) {
1007                         case DHCPV6_MSG_RENEW:
1008                                 // Send further renews if T1 is not set
1009                                 if (!t1)
1010                                         ret = -1;
1011                                 break;
1012                         case DHCPV6_MSG_REBIND:
1013                                 // Send further rebinds if T1 and T2 is not set
1014                                 if (!t1 && !t2)
1015                                         ret = -1;
1016                                 break;
1017
1018                         case DHCPV6_MSG_REQUEST:
1019                                 // All server candidates can be cleared if not yet bound
1020                                 if (!odhcp6c_is_bound())
1021                                         dhcpv6_clear_all_server_cand();
1022
1023                         default :
1024                                 break;
1025                         }
1026                 }
1027         }
1028         else if (ret > 0) {
1029                 // All server candidates can be cleared if not yet bound
1030                 if (!odhcp6c_is_bound())
1031                         dhcpv6_clear_all_server_cand();
1032
1033                 t1 = refresh;
1034         }
1035
1036         return ret;
1037 }
1038
1039
1040 static int dhcpv6_parse_ia(void *opt, void *end)
1041 {
1042         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1043         int parsed_ia = 0;
1044         uint32_t t1, t2;
1045         uint16_t otype, olen;
1046         uint8_t *odata;
1047
1048         t1 = ntohl(ia_hdr->t1);
1049         t2 = ntohl(ia_hdr->t2);
1050
1051         if (t1 > t2)
1052                 return 0;
1053
1054         // Update address IA
1055         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1056                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1057                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1058
1059                 entry.iaid = ia_hdr->iaid;
1060
1061                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1062                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1063                         if (olen + 4U < sizeof(*prefix))
1064                                 continue;
1065
1066                         entry.valid = ntohl(prefix->valid);
1067                         entry.preferred = ntohl(prefix->preferred);
1068
1069                         if (entry.preferred > entry.valid)
1070                                 continue;
1071
1072                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1073                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1074                         if (entry.t1 > entry.t2)
1075                                 entry.t1 = entry.t2;
1076
1077                         entry.length = prefix->prefix;
1078                         entry.target = prefix->addr;
1079                         uint16_t stype, slen;
1080                         uint8_t *sdata;
1081
1082 #ifdef EXT_PREFIX_CLASS
1083                         // Find prefix class, if any
1084                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1085                                         stype, slen, sdata)
1086                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1087                                         entry.class = sdata[0] << 8 | sdata[1];
1088 #endif
1089
1090                         // Parse PD-exclude
1091                         bool ok = true;
1092                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1093                                         odata + olen, stype, slen, sdata) {
1094                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1095                                         continue;
1096
1097                                 uint8_t elen = sdata[0];
1098                                 if (elen > 64)
1099                                         elen = 64;
1100
1101                                 if (elen <= 32 || elen <= entry.length) {
1102                                         ok = false;
1103                                         continue;
1104                                 }
1105
1106
1107                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1108                                 if (slen <= bytes) {
1109                                         ok = false;
1110                                         continue;
1111                                 }
1112
1113                                 uint32_t exclude = 0;
1114                                 do {
1115                                         exclude = exclude << 8 | sdata[bytes];
1116                                 } while (--bytes);
1117
1118                                 exclude >>= 8 - ((elen - entry.length) % 8);
1119                                 exclude <<= 64 - elen;
1120
1121                                 // Abusing router & priority fields for exclusion
1122                                 entry.router = entry.target;
1123                                 entry.router.s6_addr32[1] |= htonl(exclude);
1124                                 entry.priority = elen;
1125                         }
1126
1127                         if (ok) {
1128                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1129                                 parsed_ia++;
1130                         }
1131
1132                         entry.priority = 0;
1133                         memset(&entry.router, 0, sizeof(entry.router));
1134                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1135                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1136                         if (olen + 4U < sizeof(*addr))
1137                                 continue;
1138
1139                         entry.preferred = ntohl(addr->preferred);
1140                         entry.valid = ntohl(addr->valid);
1141
1142                         if (entry.preferred > entry.valid)
1143                                 continue;
1144
1145                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1146                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1147                         if (entry.t1 > entry.t2)
1148                                 entry.t1 = entry.t2;
1149
1150                         entry.length = 128;
1151                         entry.target = addr->addr;
1152
1153 #ifdef EXT_PREFIX_CLASS
1154                         uint16_t stype, slen;
1155                         uint8_t *sdata;
1156                         // Find prefix class, if any
1157                         dhcpv6_for_each_option(&addr[1], odata + olen,
1158                                         stype, slen, sdata)
1159                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1160                                         entry.class = sdata[0] << 8 | sdata[1];
1161 #endif
1162
1163                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1164                         parsed_ia++;
1165                 }
1166         }
1167         return parsed_ia;
1168 }
1169
1170
1171 static int dhcpv6_calc_refresh_timers(void)
1172 {
1173         struct odhcp6c_entry *e;
1174         size_t ia_na_entries, ia_pd_entries, i;
1175         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1176
1177         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1178         ia_na_entries /= sizeof(*e);
1179         for (i = 0; i < ia_na_entries; i++) {
1180                 if (e[i].t1 < l_t1)
1181                         l_t1 = e[i].t1;
1182
1183                 if (e[i].t2 < l_t2)
1184                         l_t2 = e[i].t2;
1185
1186                 if (e[i].valid > l_t3)
1187                         l_t3 = e[i].valid;
1188         }
1189
1190         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1191         ia_pd_entries /= sizeof(*e);
1192         for (i = 0; i < ia_pd_entries; i++) {
1193                 if (e[i].t1 < l_t1)
1194                         l_t1 = e[i].t1;
1195
1196                 if (e[i].t2 < l_t2)
1197                         l_t2 = e[i].t2;
1198
1199                 if (e[i].valid > l_t3)
1200                         l_t3 = e[i].valid;
1201         }
1202
1203         if (ia_pd_entries || ia_na_entries) {
1204                 t1 = l_t1;
1205                 t2 = l_t2;
1206                 t3 = l_t3;
1207         } else {
1208                 t1 = 600;
1209         }
1210
1211         return (int)(ia_pd_entries + ia_na_entries);
1212 }
1213
1214
1215 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1216                 const void *status_msg, const int len)
1217 {
1218         uint8_t buf[len + 3];
1219
1220         memset(buf, 0, sizeof(buf));
1221         if (len) {
1222                 buf[0] = '(';
1223                 memcpy(&buf[1], status_msg, len);
1224                 buf[len + 1] = ')';
1225         }
1226
1227         syslog(LOG_WARNING, "Server returned %s status %i %s",
1228                 scope, code, buf);
1229 }
1230
1231
1232 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1233                 const uint16_t code, const void *status_msg, const int len,
1234                 int *ret)
1235 {
1236         dhcpv6_log_status_code(code, "message", status_msg, len);
1237
1238         switch (code) {
1239         case DHCPV6_UnspecFail:
1240                 // Generic failure
1241                 *ret = 0;
1242                 break;
1243
1244         case DHCPV6_UseMulticast:
1245                 // TODO handle multicast status code
1246                 break;
1247
1248         case DHCPV6_NoAddrsAvail:
1249         case DHCPV6_NoPrefixAvail:
1250                 if (orig == DHCPV6_MSG_REQUEST)
1251                         *ret = 0; // Failure
1252                 break;
1253
1254         default:
1255                 break;
1256         }
1257 }
1258
1259
1260 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1261                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1262                 const void *status_msg, const int len,
1263                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1264 {
1265         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1266                 "IA_NA" : "IA_PD", status_msg, len);
1267
1268         switch (code) {
1269         case DHCPV6_NoBinding:
1270                 switch (orig) {
1271                 case DHCPV6_MSG_RENEW:
1272                 case DHCPV6_MSG_REBIND:
1273                         if ((*ret > 0) && !handled_status_codes[code])
1274                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1275                         break;
1276
1277                 default:
1278                         break;
1279                 }
1280                 break;
1281
1282         case DHCPV6_NoAddrsAvail:
1283         case DHCPV6_NoPrefixAvail:
1284                 switch (orig) {
1285                 case DHCPV6_MSG_REQUEST:
1286                         if (*ret != 0)
1287                                 *ret = 0;
1288                         break;
1289                 default:
1290                         break;
1291                 }
1292                 break;
1293
1294         case DHCPV6_NotOnLink:
1295                 // TODO handle not onlink in case of confirm
1296                 break;
1297
1298         default:
1299                 break;
1300         }
1301 }
1302
1303 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1304 {
1305         size_t cand_len, i;
1306         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1307
1308         // Remove identical duid server candidate
1309         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1310                 if (cand->duid_len == c[i].duid_len &&
1311                                 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1312                         free(c[i].ia_na);
1313                         free(c[i].ia_pd);
1314                         odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1315                         break;
1316                 }
1317         }
1318
1319         for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1320                 i < cand_len / sizeof(*c); ++i) {
1321                 if (c[i].preference < cand->preference)
1322                         break;
1323         }
1324
1325         odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1326 }
1327
1328 static void dhcpv6_clear_all_server_cand(void)
1329 {
1330         size_t cand_len, i;
1331         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1332
1333         // Server candidates need deep delete for IA_NA/IA_PD
1334         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1335                 free(c[i].ia_na);
1336                 free(c[i].ia_pd);
1337         }
1338         odhcp6c_clear_state(STATE_SERVER_CAND);
1339 }
1340
1341 int dhcpv6_promote_server_cand(void)
1342 {
1343         size_t cand_len;
1344         struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1345         uint16_t hdr[2];
1346         int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1347                         DHCPV6_STATELESS : DHCPV6_STATEFUL;
1348
1349         // Clear lingering candidate state info
1350         odhcp6c_clear_state(STATE_SERVER_ID);
1351         odhcp6c_clear_state(STATE_IA_NA);
1352         odhcp6c_clear_state(STATE_IA_PD);
1353
1354         if (!cand_len)
1355                 return -1;
1356
1357         if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1358                 na_mode = IA_MODE_NONE;
1359
1360                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1361                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1362
1363                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1364         }
1365
1366         hdr[0] = htons(DHCPV6_OPT_SERVERID);
1367         hdr[1] = htons(cand->duid_len);
1368         odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1369         odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1370         accept_reconfig = cand->wants_reconfigure;
1371         if (cand->ia_na_len) {
1372                 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1373                 free(cand->ia_na);
1374                 if (na_mode != IA_MODE_NONE)
1375                         ret = DHCPV6_STATEFUL;
1376         }
1377         if (cand->ia_pd_len) {
1378                 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1379                 free(cand->ia_pd);
1380                 if (request_prefix)
1381                         ret = DHCPV6_STATEFUL;
1382         }
1383
1384         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1385         dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1386
1387         odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1388
1389         return ret;
1390 }