2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
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.
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.
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
32 #include <net/ethernet.h>
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
46 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
47 const uint8_t transaction[3], enum dhcpv6_msg type);
49 static int dhcpv6_parse_ia(void *opt, void *end);
51 static int dhcpv6_calc_refresh_timers(void);
52 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
53 const uint16_t code, const void *status_msg, const int len,
55 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
56 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
57 const void *status_msg, const int len,
58 bool handled_status_codes[_DHCPV6_Status_Max],
61 static reply_handler dhcpv6_handle_reply;
62 static reply_handler dhcpv6_handle_advert;
63 static reply_handler dhcpv6_handle_rebind_reply;
64 static reply_handler dhcpv6_handle_reconfigure;
65 static int dhcpv6_commit_advert(void);
69 // RFC 3315 - 5.5 Timeout and Delay values
70 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
71 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
72 dhcpv6_handle_reconfigure, NULL},
73 [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
74 dhcpv6_handle_advert, dhcpv6_commit_advert},
75 [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
76 dhcpv6_handle_reply, NULL},
77 [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
78 dhcpv6_handle_reply, NULL},
79 [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
80 dhcpv6_handle_rebind_reply, NULL},
81 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
82 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
83 [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
84 dhcpv6_handle_reply, NULL},
90 static int ifindex = -1;
91 static int64_t t1 = 0, t2 = 0, t3 = 0;
94 static int request_prefix = -1;
95 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
96 static bool accept_reconfig = false;
99 static uint8_t reconf_key[16];
103 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
105 request_prefix = request_pd;
106 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
108 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
112 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
113 if (ioctl(sock, SIOCGIFINDEX, &ifr))
115 ifindex = ifr.ifr_ifindex;
117 // Create client DUID
118 size_t client_id_len;
119 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
120 if (client_id_len == 0) {
121 ioctl(sock, SIOCGIFHWADDR, &ifr);
122 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
123 DHCPV6_DUID_LLADDR, 0, 1};
124 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
126 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
127 struct ifreq ifs[100], *ifp, *ifend;
130 ifc.ifc_len = sizeof(ifs);
132 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
133 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
134 // If our interface doesn't have an address...
135 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
136 for (ifp = ifc.ifc_req; ifp < ifend &&
137 !memcmp(&duid[8], zero, 6); ifp++) {
138 memcpy(ifr.ifr_name, ifp->ifr_name,
139 sizeof(ifr.ifr_name));
140 ioctl(sock, SIOCGIFHWADDR, &ifr);
141 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
146 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
151 htons(DHCPV6_OPT_SIP_SERVER_D),
152 htons(DHCPV6_OPT_SIP_SERVER_A),
153 htons(DHCPV6_OPT_DNS_SERVERS),
154 htons(DHCPV6_OPT_DNS_DOMAIN),
155 htons(DHCPV6_OPT_NTP_SERVER),
156 htons(DHCPV6_OPT_SIP_SERVER_A),
157 htons(DHCPV6_OPT_AFTR_NAME),
158 htons(DHCPV6_OPT_PD_EXCLUDE),
159 #ifdef EXT_PREFIX_CLASS
160 htons(DHCPV6_OPT_PREFIX_CLASS),
163 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
166 // Configure IPv6-options
168 setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
169 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
171 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
172 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
174 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
175 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
176 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)))
183 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
190 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
194 gethostname(fqdn_buf, sizeof(fqdn_buf));
201 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
202 sizeof(fqdn.data), NULL, NULL);
203 fqdn.type = htons(DHCPV6_OPT_FQDN);
204 fqdn.len = htons(fqdn_len - 4);
210 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
214 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
217 size_t ia_pd_entries, ia_pd_len = 0;
218 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
219 ia_pd_entries /= sizeof(*e);
220 struct dhcpv6_ia_hdr hdr_ia_pd = {
221 htons(DHCPV6_OPT_IA_PD),
222 htons(sizeof(hdr_ia_pd) - 4),
227 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
228 for (size_t i = 0; i < ia_pd_entries; ++i) {
230 if (e[i].priority > 0)
231 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
233 struct dhcpv6_ia_prefix p = {
234 .type = htons(DHCPV6_OPT_IA_PREFIX),
235 .len = htons(sizeof(p) - 4U + ex_len),
236 .prefix = e[i].length,
240 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
241 ia_pd_len += sizeof(p);
244 ia_pd[ia_pd_len++] = 0;
245 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
246 ia_pd[ia_pd_len++] = 0;
247 ia_pd[ia_pd_len++] = ex_len - 4;
248 ia_pd[ia_pd_len++] = e[i].priority;
250 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
251 excl >>= (64 - e[i].priority);
252 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
254 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
255 ia_pd[ia_pd_len + i] = excl & 0xff;
256 ia_pd_len += ex_len - 5;
260 struct dhcpv6_ia_prefix pref = {
261 .type = htons(DHCPV6_OPT_IA_PREFIX),
262 .len = htons(25), .prefix = request_prefix
264 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
265 ia_pd = (uint8_t*)&pref;
266 ia_pd_len = sizeof(pref);
268 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
271 size_t ia_na_entries, ia_na_len = 0;
273 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
274 ia_na_entries /= sizeof(*e);
276 struct dhcpv6_ia_hdr hdr_ia_na = {
277 htons(DHCPV6_OPT_IA_NA),
278 htons(sizeof(hdr_ia_na) - 4),
282 struct dhcpv6_ia_addr pa[ia_na_entries];
283 for (size_t i = 0; i < ia_na_entries; ++i) {
284 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
285 pa[i].len = htons(sizeof(pa[i]) - 4U);
286 pa[i].addr = e[i].target;
292 ia_na_len = sizeof(pa);
293 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
295 // Reconfigure Accept
299 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
301 // Request Information Refresh
302 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
306 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
310 uint16_t elapsed_type;
311 uint16_t elapsed_len;
312 uint16_t elapsed_value;
316 type, {trid[0], trid[1], trid[2]},
317 htons(DHCPV6_OPT_ELAPSED), htons(2),
318 htons((ecs > 0xffff) ? 0xffff : ecs),
319 htons(DHCPV6_OPT_ORO), htons(oro_len),
322 struct iovec iov[] = {
327 {srv_id, srv_id_len},
328 {&reconf_accept, sizeof(reconf_accept)},
330 {&hdr_ia_na, sizeof(hdr_ia_na)},
332 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
336 size_t cnt = ARRAY_SIZE(iov);
337 if (type == DHCPV6_MSG_INFO_REQ) {
339 iov[2].iov_len = sizeof(oro_refresh);
340 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
341 } else if (!request_prefix) {
345 // Disable IAs if not used
346 if (type != DHCPV6_MSG_SOLICIT) {
354 if (na_mode == IA_MODE_NONE)
357 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
358 0, ALL_DHCPV6_RELAYS, ifindex};
359 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
361 sendmsg(sock, &msg, 0);
365 static int64_t dhcpv6_rand_delay(int64_t time)
368 odhcp6c_random(&random, sizeof(random));
369 return (time * ((int64_t)random % 1000LL)) / 10000LL;
373 int dhcpv6_request(enum dhcpv6_msg type)
375 uint8_t buf[1536], rc = 0;
376 uint64_t timeout = UINT32_MAX;
377 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
380 struct timespec ts = {0, 0};
381 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
382 nanosleep(&ts, NULL);
385 if (type == DHCPV6_MSG_UNKNOWN)
387 else if (type == DHCPV6_MSG_RENEW)
388 timeout = (t2 > t1) ? t2 - t1 : 0;
389 else if (type == DHCPV6_MSG_REBIND)
390 timeout = (t3 > t2) ? t3 - t2 : 0;
395 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
396 retx->name, (unsigned long long)timeout, retx->max_rc);
398 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
400 // Generate transaction ID
401 uint8_t trid[3] = {0, 0, 0};
402 if (type != DHCPV6_MSG_UNKNOWN)
403 odhcp6c_random(trid, sizeof(trid));
409 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
411 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
412 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
413 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
415 rto = (retx->init_timeo * 1000 + delay);
418 rto = (2 * rto + dhcpv6_rand_delay(rto));
420 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
421 rto = retx->max_timeo * 1000 +
422 dhcpv6_rand_delay(retx->max_timeo * 1000);
424 // Calculate end for this round and elapsed time
425 uint64_t round_end = round_start + rto;
426 elapsed = round_start - start;
428 // Don't wait too long
429 if (round_end - start > timeout * 1000)
430 round_end = timeout * 1000 + start;
432 // Built and send package
433 if (type != DHCPV6_MSG_UNKNOWN) {
434 if (type != DHCPV6_MSG_SOLICIT)
435 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
436 retx->name, (unsigned long long)elapsed, rc);
437 dhcpv6_send(type, trid, elapsed / 10);
442 for (; len < 0 && round_start < round_end;
443 round_start = odhcp6c_get_milli_time()) {
444 // Check for pending signal
445 if (odhcp6c_signal_process())
448 // Set timeout for receiving
449 uint64_t t = round_end - round_start;
450 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
451 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
452 &timeout, sizeof(timeout));
455 len = recv(sock, buf, sizeof(buf), 0);
457 if (!dhcpv6_response_is_valid(buf, len, trid, type))
461 uint8_t *opt = &buf[4];
462 uint8_t *opt_end = opt + len - 4;
464 round_start = odhcp6c_get_milli_time();
465 elapsed = round_start - start;
466 syslog(LOG_NOTICE, "Got a valid reply after "
467 "%llums", (unsigned long long)elapsed);
469 if (retx->handler_reply)
470 len = retx->handler_reply(
471 type, rc, opt, opt_end);
473 if (len > 0 && round_end - round_start > 1000)
474 round_end = 1000 + round_start;
479 if (retx->handler_finish)
480 len = retx->handler_finish();
481 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
487 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
488 const uint8_t transaction[3], enum dhcpv6_msg type)
490 const struct dhcpv6_header *rep = buf;
491 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
492 transaction, sizeof(rep->tr_id)))
493 return false; // Invalid reply
495 if (type == DHCPV6_MSG_SOLICIT) {
496 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
497 rep->msg_type != DHCPV6_MSG_REPLY)
499 } else if (type == DHCPV6_MSG_UNKNOWN) {
500 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
502 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
506 uint8_t *end = ((uint8_t*)buf) + len, *odata;
507 uint16_t otype, olen;
508 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false;
510 size_t client_id_len, server_id_len;
511 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
512 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
514 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
515 if (otype == DHCPV6_OPT_CLIENTID) {
516 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
517 &odata[-4], client_id, client_id_len);
518 } else if (otype == DHCPV6_OPT_SERVERID) {
519 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
520 &odata[-4], server_id, server_id_len);
521 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
522 sizeof(struct dhcpv6_auth_reconfigure)) {
523 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
524 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
528 uint8_t serverhash[16], secretbytes[16], hash[16];
529 memcpy(serverhash, r->key, sizeof(serverhash));
530 memset(r->key, 0, sizeof(r->key));
531 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
533 for (size_t i = 0; i < sizeof(secretbytes); ++i)
534 secretbytes[i] ^= 0x36;
537 md5_append(&md5, secretbytes, sizeof(secretbytes));
538 md5_append(&md5, buf, len);
539 md5_finish(&md5, hash);
541 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
542 secretbytes[i] ^= 0x36;
543 secretbytes[i] ^= 0x5c;
547 md5_append(&md5, secretbytes, sizeof(secretbytes));
548 md5_append(&md5, hash, 16);
549 md5_finish(&md5, hash);
551 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
555 if (rep->msg_type == DHCPV6_MSG_RECONF && !rcauth_ok)
558 return clientid_ok && (serverid_ok || server_id_len == 0);
562 int dhcpv6_poll_reconfigure(void)
564 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
566 ret = dhcpv6_request(ret);
572 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
573 const void *opt, const void *end)
575 // TODO: should verify the reconfigure message
576 uint16_t otype, olen;
577 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
578 dhcpv6_for_each_option(opt, end, otype, olen, odata)
579 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
580 odata[0] == DHCPV6_MSG_RENEW ||
581 odata[0] == DHCPV6_MSG_INFO_REQ))
584 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
589 // Collect all advertised servers
590 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
591 const void *opt, const void *end)
593 uint16_t olen, otype;
594 uint8_t *odata, pref = 0;
595 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0};
596 bool have_na = false;
599 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
600 if (orig == DHCPV6_MSG_SOLICIT &&
601 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
602 olen > sizeof(struct dhcpv6_ia_hdr)) {
603 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
604 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
607 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
608 memcpy(cand.duid, odata, olen);
609 cand.duid_len = olen;
610 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
611 int error = ((int)odata[0] << 8 | (int)odata[1]);
614 case DHCPV6_NoPrefixAvail:
615 // Status code on global level
616 if (pd_mode == IA_MODE_FORCE)
618 cand.preference -= 2000;
621 case DHCPV6_NoAddrsAvail:
622 // Status code on global level
623 if (na_mode == IA_MODE_FORCE)
630 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
631 cand.preference >= 0) {
632 cand.preference = pref = odata[0];
633 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
634 cand.wants_reconfigure = true;
635 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
636 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
637 uint8_t *oend = odata + olen, *d;
638 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
639 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
640 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
641 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
645 } else if (otype == DHCPV6_OPT_IA_NA) {
646 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
647 uint8_t *oend = odata + olen, *d;
648 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
649 if (otype == DHCPV6_OPT_IA_ADDR)
654 if ((!have_na && na_mode == IA_MODE_FORCE) ||
655 (!have_pd && pd_mode == IA_MODE_FORCE))
658 if (na_mode != IA_MODE_NONE && !have_na) {
659 cand.has_noaddravail = true;
660 cand.preference -= 1000;
663 if (pd_mode != IA_MODE_NONE) {
665 cand.preference += 2000 + (128 - have_pd);
667 cand.preference -= 2000;
670 if (cand.duid_len > 0) {
671 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
672 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
673 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
676 if (orig == DHCPV6_MSG_SOLICIT) {
677 odhcp6c_clear_state(STATE_IA_NA);
678 odhcp6c_clear_state(STATE_IA_PD);
681 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
685 static int dhcpv6_commit_advert(void)
688 struct dhcpv6_server_cand *c = NULL, *cand =
689 odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
692 for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
693 if (cand[i].has_noaddravail)
694 retry = true; // We want to try again
696 if (!c || c->preference < cand[i].preference)
700 if (retry && na_mode == IA_MODE_TRY) {
701 // We give it a second try without the IA_NA
702 na_mode = IA_MODE_NONE;
703 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
707 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
709 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
710 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
711 accept_reconfig = c->wants_reconfigure;
713 odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
715 odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
718 for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
722 odhcp6c_clear_state(STATE_SERVER_CAND);
726 else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
727 return DHCPV6_STATEFUL;
729 return DHCPV6_STATELESS;
733 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
734 const void *opt, const void *end)
736 dhcpv6_handle_advert(orig, rc, opt, end);
737 if (dhcpv6_commit_advert() < 0) {
738 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
742 return dhcpv6_handle_reply(orig, rc, opt, end);
746 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
747 const void *opt, const void *end)
750 uint16_t otype, olen;
751 uint32_t refresh = UINT32_MAX;
753 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
757 if (orig == DHCPV6_MSG_UNKNOWN) {
758 static time_t last_update = 0;
759 time_t now = odhcp6c_get_milli_time() / 1000;
761 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
778 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
779 // Delete NA and PD we have in the state from the Advert
780 odhcp6c_clear_state(STATE_IA_NA);
781 odhcp6c_clear_state(STATE_IA_PD);
785 odhcp6c_clear_state(STATE_DNS);
786 odhcp6c_clear_state(STATE_SEARCH);
787 odhcp6c_clear_state(STATE_SNTP_IP);
788 odhcp6c_clear_state(STATE_SNTP_FQDN);
789 odhcp6c_clear_state(STATE_SIP_IP);
790 odhcp6c_clear_state(STATE_SIP_FQDN);
791 odhcp6c_clear_state(STATE_AFTR_NAME);
794 // Parse and find all matching IAs
795 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
796 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
797 && olen > sizeof(struct dhcpv6_ia_hdr)) {
798 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
801 if (ia_hdr->iaid != 1)
804 uint16_t code = DHCPV6_Success;
805 uint16_t stype, slen;
807 // Get and handle status code
808 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
809 stype, slen, sdata) {
810 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
811 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
812 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
814 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
816 if (code == DHCPV6_Success)
819 dhcpv6_handle_ia_status_code(orig, ia_hdr,
820 code, mdata, mlen, handled_status_codes, &ret);
829 if (code != DHCPV6_Success)
832 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
833 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
834 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
835 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
836 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
838 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
840 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
842 odhcp6c_add_state(STATE_DNS, odata, olen);
843 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
844 odhcp6c_add_state(STATE_SEARCH, odata, olen);
845 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
846 uint16_t stype, slen;
848 // Test status and bail if error
849 dhcpv6_for_each_option(odata, odata + olen,
850 stype, slen, sdata) {
851 if (slen == 16 && (stype == NTP_MC_ADDR ||
852 stype == NTP_SRV_ADDR))
853 odhcp6c_add_state(STATE_SNTP_IP,
855 else if (slen > 0 && stype == NTP_SRV_FQDN)
856 odhcp6c_add_state(STATE_SNTP_FQDN,
859 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
861 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
862 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
863 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
864 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
865 refresh = ntohl(*((uint32_t*)odata));
866 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
867 sizeof(struct dhcpv6_auth_reconfigure)) {
868 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
869 if (r->protocol == 3 && r->algorithm == 1 &&
871 memcpy(reconf_key, r->key, sizeof(r->key));
872 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
874 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
876 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
877 } else if (otype != DHCPV6_OPT_CLIENTID &&
878 otype != DHCPV6_OPT_SERVERID) {
879 odhcp6c_add_state(STATE_CUSTOM_OPTS,
880 &odata[-4], olen + 4);
884 if (orig != DHCPV6_MSG_INFO_REQ) {
885 // Update refresh timers if no fatal status code was received
886 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
888 case DHCPV6_MSG_RENEW:
889 // Send further renews if T1 is not set
893 case DHCPV6_MSG_REBIND:
894 // Send further rebinds if T1 and T2 is not set
911 static int dhcpv6_parse_ia(void *opt, void *end)
913 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
916 uint16_t otype, olen;
919 t1 = ntohl(ia_hdr->t1);
920 t2 = ntohl(ia_hdr->t2);
926 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
927 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
928 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
930 if (otype == DHCPV6_OPT_IA_PREFIX) {
931 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
932 if (olen + 4U < sizeof(*prefix))
935 entry.valid = ntohl(prefix->valid);
936 entry.preferred = ntohl(prefix->preferred);
938 if (entry.preferred > entry.valid)
941 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
942 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
943 if (entry.t1 > entry.t2)
946 entry.length = prefix->prefix;
947 entry.target = prefix->addr;
948 uint16_t stype, slen;
951 #ifdef EXT_PREFIX_CLASS
952 // Find prefix class, if any
953 dhcpv6_for_each_option(&prefix[1], odata + olen,
955 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
956 entry.class = sdata[0] << 8 | sdata[1];
961 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
962 odata + olen, stype, slen, sdata) {
963 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
966 uint8_t elen = sdata[0];
970 if (elen <= 32 || elen <= entry.length) {
976 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
982 uint32_t exclude = 0;
984 exclude = exclude << 8 | sdata[bytes];
987 exclude >>= 8 - ((elen - entry.length) % 8);
988 exclude <<= 64 - elen;
990 // Abusing router & priority fields for exclusion
991 entry.router = entry.target;
992 entry.router.s6_addr32[1] |= htonl(exclude);
993 entry.priority = elen;
997 odhcp6c_update_entry(STATE_IA_PD, &entry);
1002 memset(&entry.router, 0, sizeof(entry.router));
1003 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1004 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1005 if (olen + 4U < sizeof(*addr))
1008 entry.preferred = ntohl(addr->preferred);
1009 entry.valid = ntohl(addr->valid);
1011 if (entry.preferred > entry.valid)
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;
1020 entry.target = addr->addr;
1022 #ifdef EXT_PREFIX_CLASS
1023 uint16_t stype, slen;
1025 // Find prefix class, if any
1026 dhcpv6_for_each_option(&addr[1], odata + olen,
1028 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1029 entry.class = sdata[0] << 8 | sdata[1];
1032 odhcp6c_update_entry(STATE_IA_NA, &entry);
1040 static int dhcpv6_calc_refresh_timers(void)
1042 struct odhcp6c_entry *e;
1043 size_t ia_na_entries, ia_pd_entries, i;
1044 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1046 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1047 ia_na_entries /= sizeof(*e);
1048 for (i = 0; i < ia_na_entries; i++) {
1055 if (e[i].valid > l_t3)
1059 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1060 ia_pd_entries /= sizeof(*e);
1061 for (i = 0; i < ia_pd_entries; i++) {
1068 if (e[i].valid > l_t3)
1072 if (ia_pd_entries || ia_na_entries) {
1078 return (int)(ia_pd_entries + ia_na_entries);
1082 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1083 const void *status_msg, const int len)
1085 uint8_t buf[len + 3];
1087 memset(buf, 0, sizeof(buf));
1090 memcpy(&buf[1], status_msg, len);
1094 syslog(LOG_WARNING, "Server returned %s status %i %s",
1099 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1100 const uint16_t code, const void *status_msg, const int len,
1103 dhcpv6_log_status_code(code, "message", status_msg, len);
1106 case DHCPV6_UnspecFail:
1111 case DHCPV6_UseMulticast:
1112 // TODO handle multicast status code
1115 case DHCPV6_NoAddrsAvail:
1116 case DHCPV6_NoPrefixAvail:
1117 if (orig == DHCPV6_MSG_REQUEST)
1118 *ret = 0; // Failure
1127 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1128 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1129 const void *status_msg, const int len,
1130 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1132 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1133 "IA_NA" : "IA_PD", status_msg, len);
1136 case DHCPV6_NoBinding:
1138 case DHCPV6_MSG_RENEW:
1139 case DHCPV6_MSG_REBIND:
1140 if ((*ret > 0) && !handled_status_codes[code])
1141 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1149 case DHCPV6_NoAddrsAvail:
1150 case DHCPV6_NoPrefixAvail:
1152 case DHCPV6_MSG_REQUEST:
1161 case DHCPV6_NotOnLink:
1162 // TODO handle not onlink in case of confirm