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,
48 const struct in6_addr *daddr);
50 static int dhcpv6_parse_ia(void *opt, void *end);
52 static int dhcpv6_calc_refresh_timers(void);
53 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
54 const uint16_t code, const void *status_msg, const int len,
56 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
57 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
58 const void *status_msg, const int len,
59 bool handled_status_codes[_DHCPV6_Status_Max],
62 static reply_handler dhcpv6_handle_reply;
63 static reply_handler dhcpv6_handle_advert;
64 static reply_handler dhcpv6_handle_rebind_reply;
65 static reply_handler dhcpv6_handle_reconfigure;
66 static int dhcpv6_commit_advert(void);
70 // RFC 3315 - 5.5 Timeout and Delay values
71 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
72 [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
73 dhcpv6_handle_reconfigure, NULL},
74 [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
75 dhcpv6_handle_advert, dhcpv6_commit_advert},
76 [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
77 dhcpv6_handle_reply, NULL},
78 [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
79 dhcpv6_handle_reply, NULL},
80 [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
81 dhcpv6_handle_rebind_reply, NULL},
82 [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
83 [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
84 [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
85 dhcpv6_handle_reply, NULL},
91 static int ifindex = -1;
92 static int64_t t1 = 0, t2 = 0, t3 = 0;
95 static int request_prefix = -1;
96 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
97 static bool accept_reconfig = false;
100 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);
114 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
115 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
117 ifindex = ifr.ifr_ifindex;
119 // Create client DUID
120 size_t client_id_len;
121 odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
122 if (client_id_len == 0) {
123 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
124 DHCPV6_DUID_LLADDR, 0, 1};
126 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
127 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
129 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
130 struct ifreq ifs[100], *ifp, *ifend;
133 ifc.ifc_len = sizeof(ifs);
135 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
136 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
137 // If our interface doesn't have an address...
138 ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
139 for (ifp = ifc.ifc_req; ifp < ifend &&
140 !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
141 memcpy(ifr.ifr_name, ifp->ifr_name,
142 sizeof(ifr.ifr_name));
143 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
145 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
150 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
155 htons(DHCPV6_OPT_SIP_SERVER_D),
156 htons(DHCPV6_OPT_SIP_SERVER_A),
157 htons(DHCPV6_OPT_DNS_SERVERS),
158 htons(DHCPV6_OPT_DNS_DOMAIN),
159 htons(DHCPV6_OPT_NTP_SERVER),
160 htons(DHCPV6_OPT_AFTR_NAME),
161 htons(DHCPV6_OPT_PD_EXCLUDE),
162 #ifdef EXT_PREFIX_CLASS
163 htons(DHCPV6_OPT_PREFIX_CLASS),
166 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
169 // Configure IPv6-options
171 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
173 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
175 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
179 if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)) < 0)
181 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
184 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
185 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
186 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
196 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
203 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
207 gethostname(fqdn_buf, sizeof(fqdn_buf));
214 size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
215 sizeof(fqdn.data), NULL, NULL);
216 fqdn.type = htons(DHCPV6_OPT_FQDN);
217 fqdn.len = htons(fqdn_len - 4);
223 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
227 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
230 size_t ia_pd_entries, ia_pd_len = 0;
231 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
232 ia_pd_entries /= sizeof(*e);
233 struct dhcpv6_ia_hdr hdr_ia_pd = {
234 htons(DHCPV6_OPT_IA_PD),
235 htons(sizeof(hdr_ia_pd) - 4),
240 uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
241 for (size_t i = 0; i < ia_pd_entries; ++i) {
243 if (e[i].priority > 0)
244 ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
246 struct dhcpv6_ia_prefix p = {
247 .type = htons(DHCPV6_OPT_IA_PREFIX),
248 .len = htons(sizeof(p) - 4U + ex_len),
249 .prefix = e[i].length,
253 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
254 ia_pd_len += sizeof(p);
257 ia_pd[ia_pd_len++] = 0;
258 ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
259 ia_pd[ia_pd_len++] = 0;
260 ia_pd[ia_pd_len++] = ex_len - 4;
261 ia_pd[ia_pd_len++] = e[i].priority;
263 uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
264 excl >>= (64 - e[i].priority);
265 excl <<= 8 - ((e[i].priority - e[i].length) % 8);
267 for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
268 ia_pd[ia_pd_len + i] = excl & 0xff;
269 ia_pd_len += ex_len - 5;
273 struct dhcpv6_ia_prefix pref = {
274 .type = htons(DHCPV6_OPT_IA_PREFIX),
275 .len = htons(25), .prefix = request_prefix
277 if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
278 ia_pd = (uint8_t*)&pref;
279 ia_pd_len = sizeof(pref);
281 hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
284 size_t ia_na_entries, ia_na_len = 0;
286 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
287 ia_na_entries /= sizeof(*e);
289 struct dhcpv6_ia_hdr hdr_ia_na = {
290 htons(DHCPV6_OPT_IA_NA),
291 htons(sizeof(hdr_ia_na) - 4),
295 struct dhcpv6_ia_addr pa[ia_na_entries];
296 for (size_t i = 0; i < ia_na_entries; ++i) {
297 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
298 pa[i].len = htons(sizeof(pa[i]) - 4U);
299 pa[i].addr = e[i].target;
305 ia_na_len = sizeof(pa);
306 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
308 // Reconfigure Accept
312 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
314 // Request Information Refresh
315 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
319 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
323 uint16_t elapsed_type;
324 uint16_t elapsed_len;
325 uint16_t elapsed_value;
329 type, {trid[0], trid[1], trid[2]},
330 htons(DHCPV6_OPT_ELAPSED), htons(2),
331 htons((ecs > 0xffff) ? 0xffff : ecs),
332 htons(DHCPV6_OPT_ORO), htons(oro_len),
335 struct iovec iov[] = {
340 {srv_id, srv_id_len},
341 {&reconf_accept, sizeof(reconf_accept)},
343 {&hdr_ia_na, sizeof(hdr_ia_na)},
345 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
349 size_t cnt = ARRAY_SIZE(iov);
350 if (type == DHCPV6_MSG_INFO_REQ) {
352 iov[2].iov_len = sizeof(oro_refresh);
353 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
354 } else if (!request_prefix) {
358 // Disable IAs if not used
359 if (type != DHCPV6_MSG_SOLICIT) {
367 if (na_mode == IA_MODE_NONE)
370 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
371 0, ALL_DHCPV6_RELAYS, ifindex};
372 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
374 sendmsg(sock, &msg, 0);
378 static int64_t dhcpv6_rand_delay(int64_t time)
381 odhcp6c_random(&random, sizeof(random));
382 return (time * ((int64_t)random % 1000LL)) / 10000LL;
386 int dhcpv6_request(enum dhcpv6_msg type)
389 uint64_t timeout = UINT32_MAX;
390 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
393 struct timespec ts = {0, 0};
394 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
395 nanosleep(&ts, NULL);
398 if (type == DHCPV6_MSG_UNKNOWN)
400 else if (type == DHCPV6_MSG_RENEW)
401 timeout = (t2 > t1) ? t2 - t1 : 0;
402 else if (type == DHCPV6_MSG_REBIND)
403 timeout = (t3 > t2) ? t3 - t2 : 0;
408 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
409 retx->name, (unsigned long long)timeout, retx->max_rc);
411 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
413 // Generate transaction ID
414 uint8_t trid[3] = {0, 0, 0};
415 if (type != DHCPV6_MSG_UNKNOWN)
416 odhcp6c_random(trid, sizeof(trid));
422 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
424 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
425 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
426 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
428 rto = (retx->init_timeo * 1000 + delay);
431 rto = (2 * rto + dhcpv6_rand_delay(rto));
433 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
434 rto = retx->max_timeo * 1000 +
435 dhcpv6_rand_delay(retx->max_timeo * 1000);
437 // Calculate end for this round and elapsed time
438 uint64_t round_end = round_start + rto;
439 elapsed = round_start - start;
441 // Don't wait too long
442 if (round_end - start > timeout * 1000)
443 round_end = timeout * 1000 + start;
445 // Built and send package
446 if (type != DHCPV6_MSG_UNKNOWN) {
447 if (type != DHCPV6_MSG_SOLICIT)
448 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
449 retx->name, (unsigned long long)elapsed, rc);
450 dhcpv6_send(type, trid, elapsed / 10);
455 for (; len < 0 && round_start < round_end;
456 round_start = odhcp6c_get_milli_time()) {
457 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
458 struct iovec iov = {buf, sizeof(buf)};
459 struct msghdr msg = {NULL, 0, &iov, 1,
460 cmsg_buf, sizeof(cmsg_buf), 0};
461 struct in6_pktinfo *pktinfo = NULL;
463 // Check for pending signal
464 if (odhcp6c_signal_process())
467 // Set timeout for receiving
468 uint64_t t = round_end - round_start;
469 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
470 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
471 &timeout, sizeof(timeout));
474 len = recvmsg(sock, &msg, 0);
478 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
479 ch = CMSG_NXTHDR(&msg, ch)) {
480 if (ch->cmsg_level == SOL_IPV6 &&
481 ch->cmsg_type == IPV6_PKTINFO) {
482 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
487 if (pktinfo == NULL) {
492 if (!dhcpv6_response_is_valid(buf, len, trid,
493 type, &pktinfo->ipi6_addr)) {
498 uint8_t *opt = &buf[4];
499 uint8_t *opt_end = opt + len - 4;
501 round_start = odhcp6c_get_milli_time();
502 elapsed = round_start - start;
503 syslog(LOG_NOTICE, "Got a valid reply after "
504 "%llums", (unsigned long long)elapsed);
506 if (retx->handler_reply)
507 len = retx->handler_reply(type, rc, opt, opt_end);
509 if (len > 0 && round_end - round_start > 1000)
510 round_end = 1000 + round_start;
514 if (retx->handler_finish)
515 len = retx->handler_finish();
516 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
521 // Message validation checks according to RFC3315 chapter 15
522 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
523 const uint8_t transaction[3], enum dhcpv6_msg type,
524 const struct in6_addr *daddr)
526 const struct dhcpv6_header *rep = buf;
527 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
528 transaction, sizeof(rep->tr_id)))
529 return false; // Invalid reply
531 if (type == DHCPV6_MSG_SOLICIT) {
532 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
533 rep->msg_type != DHCPV6_MSG_REPLY)
535 } else if (type == DHCPV6_MSG_UNKNOWN) {
536 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
538 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
542 uint8_t *end = ((uint8_t*)buf) + len, *odata,
543 rcmsg = DHCPV6_MSG_UNKNOWN;
544 uint16_t otype, olen;
545 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
546 ia_present = false, options_valid = true;
548 size_t client_id_len, server_id_len;
549 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
550 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
552 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
553 if (otype == DHCPV6_OPT_CLIENTID) {
554 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
555 &odata[-4], client_id, client_id_len);
556 } else if (otype == DHCPV6_OPT_SERVERID) {
558 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
559 &odata[-4], server_id, server_id_len);
562 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
563 sizeof(struct dhcpv6_auth_reconfigure)) {
564 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
565 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
569 uint8_t serverhash[16], secretbytes[16], hash[16];
570 memcpy(serverhash, r->key, sizeof(serverhash));
571 memset(r->key, 0, sizeof(r->key));
572 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
574 for (size_t i = 0; i < sizeof(secretbytes); ++i)
575 secretbytes[i] ^= 0x36;
578 md5_append(&md5, secretbytes, sizeof(secretbytes));
579 md5_append(&md5, buf, len);
580 md5_finish(&md5, hash);
582 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
583 secretbytes[i] ^= 0x36;
584 secretbytes[i] ^= 0x5c;
588 md5_append(&md5, secretbytes, sizeof(secretbytes));
589 md5_append(&md5, hash, 16);
590 md5_finish(&md5, hash);
592 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
593 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
595 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
597 if (olen < sizeof(struct dhcpv6_ia_hdr))
598 options_valid = false;
600 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
601 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
602 // Options are not allowed on global level
603 options_valid = false;
610 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
613 if (rep->msg_type == DHCPV6_MSG_RECONF) {
614 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
615 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
616 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
620 return clientid_ok && serverid_ok;
624 int dhcpv6_poll_reconfigure(void)
626 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
628 ret = dhcpv6_request(ret);
634 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
635 const void *opt, const void *end)
637 uint16_t otype, olen;
638 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
639 dhcpv6_for_each_option(opt, end, otype, olen, odata)
640 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
641 odata[0] == DHCPV6_MSG_RENEW ||
642 odata[0] == DHCPV6_MSG_INFO_REQ))
645 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
650 // Collect all advertised servers
651 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
652 const void *opt, const void *end)
654 uint16_t olen, otype;
655 uint8_t *odata, pref = 0;
656 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0};
657 bool have_na = false;
660 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
661 if (orig == DHCPV6_MSG_SOLICIT &&
662 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
663 olen > sizeof(struct dhcpv6_ia_hdr)) {
664 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
665 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
668 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
669 memcpy(cand.duid, odata, olen);
670 cand.duid_len = olen;
671 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
672 int error = ((int)odata[0] << 8 | (int)odata[1]);
675 case DHCPV6_NoPrefixAvail:
676 // Status code on global level
677 if (pd_mode == IA_MODE_FORCE)
679 cand.preference -= 2000;
682 case DHCPV6_NoAddrsAvail:
683 // Status code on global level
684 if (na_mode == IA_MODE_FORCE)
691 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
692 cand.preference >= 0) {
693 cand.preference = pref = odata[0];
694 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
695 cand.wants_reconfigure = true;
696 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
697 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
698 uint8_t *oend = odata + olen, *d;
699 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
700 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
701 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
702 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
706 } else if (otype == DHCPV6_OPT_IA_NA) {
707 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
708 uint8_t *oend = odata + olen, *d;
709 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
710 if (otype == DHCPV6_OPT_IA_ADDR)
715 if ((!have_na && na_mode == IA_MODE_FORCE) ||
716 (!have_pd && pd_mode == IA_MODE_FORCE))
719 if (na_mode != IA_MODE_NONE && !have_na) {
720 cand.has_noaddravail = true;
721 cand.preference -= 1000;
724 if (pd_mode != IA_MODE_NONE) {
726 cand.preference += 2000 + (128 - have_pd);
728 cand.preference -= 2000;
731 if (cand.duid_len > 0) {
732 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
733 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
734 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
737 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
741 static int dhcpv6_commit_advert(void)
744 struct dhcpv6_server_cand *c = NULL, *cand =
745 odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
748 for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
749 if (cand[i].has_noaddravail)
750 retry = true; // We want to try again
752 if (!c || c->preference < cand[i].preference)
756 if (retry && na_mode == IA_MODE_TRY) {
757 // We give it a second try without the IA_NA
758 na_mode = IA_MODE_NONE;
759 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
763 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
765 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
766 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
767 accept_reconfig = c->wants_reconfigure;
769 odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
771 odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
774 for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
778 odhcp6c_clear_state(STATE_SERVER_CAND);
782 else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
783 return DHCPV6_STATEFUL;
785 return DHCPV6_STATELESS;
789 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
790 const void *opt, const void *end)
792 dhcpv6_handle_advert(orig, rc, opt, end);
793 if (dhcpv6_commit_advert() < 0)
796 return dhcpv6_handle_reply(orig, rc, opt, end);
800 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
801 const void *opt, const void *end)
804 uint16_t otype, olen;
805 uint32_t refresh = UINT32_MAX;
807 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
811 if (orig == DHCPV6_MSG_UNKNOWN) {
812 static time_t last_update = 0;
813 time_t now = odhcp6c_get_milli_time() / 1000;
815 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
832 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
833 // Delete NA and PD we have in the state from the Advert
834 odhcp6c_clear_state(STATE_IA_NA);
835 odhcp6c_clear_state(STATE_IA_PD);
839 odhcp6c_clear_state(STATE_DNS);
840 odhcp6c_clear_state(STATE_SEARCH);
841 odhcp6c_clear_state(STATE_SNTP_IP);
842 odhcp6c_clear_state(STATE_SNTP_FQDN);
843 odhcp6c_clear_state(STATE_SIP_IP);
844 odhcp6c_clear_state(STATE_SIP_FQDN);
845 odhcp6c_clear_state(STATE_AFTR_NAME);
848 // Parse and find all matching IAs
849 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
850 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
851 && olen > sizeof(struct dhcpv6_ia_hdr)) {
852 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
855 if (ia_hdr->iaid != 1)
858 uint16_t code = DHCPV6_Success;
859 uint16_t stype, slen;
861 // Get and handle status code
862 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
863 stype, slen, sdata) {
864 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
865 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
866 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
868 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
870 if (code == DHCPV6_Success)
873 dhcpv6_handle_ia_status_code(orig, ia_hdr,
874 code, mdata, mlen, handled_status_codes, &ret);
883 if (code != DHCPV6_Success)
886 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
887 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
888 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
889 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
890 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
892 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
894 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
896 odhcp6c_add_state(STATE_DNS, odata, olen);
897 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
898 odhcp6c_add_state(STATE_SEARCH, odata, olen);
899 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
900 uint16_t stype, slen;
902 // Test status and bail if error
903 dhcpv6_for_each_option(odata, odata + olen,
904 stype, slen, sdata) {
905 if (slen == 16 && (stype == NTP_MC_ADDR ||
906 stype == NTP_SRV_ADDR))
907 odhcp6c_add_state(STATE_SNTP_IP,
909 else if (slen > 0 && stype == NTP_SRV_FQDN)
910 odhcp6c_add_state(STATE_SNTP_FQDN,
913 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
915 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
916 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
917 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
918 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
919 refresh = ntohl(*((uint32_t*)odata));
920 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
921 sizeof(struct dhcpv6_auth_reconfigure)) {
922 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
923 if (r->protocol == 3 && r->algorithm == 1 &&
925 memcpy(reconf_key, r->key, sizeof(r->key));
926 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
928 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
930 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
931 } else if (otype != DHCPV6_OPT_CLIENTID &&
932 otype != DHCPV6_OPT_SERVERID) {
933 odhcp6c_add_state(STATE_CUSTOM_OPTS,
934 &odata[-4], olen + 4);
938 if (orig != DHCPV6_MSG_INFO_REQ) {
939 // Update refresh timers if no fatal status code was received
940 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
942 case DHCPV6_MSG_RENEW:
943 // Send further renews if T1 is not set
947 case DHCPV6_MSG_REBIND:
948 // Send further rebinds if T1 and T2 is not set
965 static int dhcpv6_parse_ia(void *opt, void *end)
967 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
970 uint16_t otype, olen;
973 t1 = ntohl(ia_hdr->t1);
974 t2 = ntohl(ia_hdr->t2);
980 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
981 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
982 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
984 if (otype == DHCPV6_OPT_IA_PREFIX) {
985 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
986 if (olen + 4U < sizeof(*prefix))
989 entry.valid = ntohl(prefix->valid);
990 entry.preferred = ntohl(prefix->preferred);
992 if (entry.preferred > entry.valid)
995 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
996 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
997 if (entry.t1 > entry.t2)
1000 entry.length = prefix->prefix;
1001 entry.target = prefix->addr;
1002 uint16_t stype, slen;
1005 #ifdef EXT_PREFIX_CLASS
1006 // Find prefix class, if any
1007 dhcpv6_for_each_option(&prefix[1], odata + olen,
1009 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1010 entry.class = sdata[0] << 8 | sdata[1];
1015 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1016 odata + olen, stype, slen, sdata) {
1017 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1020 uint8_t elen = sdata[0];
1024 if (elen <= 32 || elen <= entry.length) {
1030 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1031 if (slen <= bytes) {
1036 uint32_t exclude = 0;
1038 exclude = exclude << 8 | sdata[bytes];
1041 exclude >>= 8 - ((elen - entry.length) % 8);
1042 exclude <<= 64 - elen;
1044 // Abusing router & priority fields for exclusion
1045 entry.router = entry.target;
1046 entry.router.s6_addr32[1] |= htonl(exclude);
1047 entry.priority = elen;
1051 odhcp6c_update_entry(STATE_IA_PD, &entry);
1056 memset(&entry.router, 0, sizeof(entry.router));
1057 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1058 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1059 if (olen + 4U < sizeof(*addr))
1062 entry.preferred = ntohl(addr->preferred);
1063 entry.valid = ntohl(addr->valid);
1065 if (entry.preferred > entry.valid)
1068 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1069 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1070 if (entry.t1 > entry.t2)
1071 entry.t1 = entry.t2;
1074 entry.target = addr->addr;
1076 #ifdef EXT_PREFIX_CLASS
1077 uint16_t stype, slen;
1079 // Find prefix class, if any
1080 dhcpv6_for_each_option(&addr[1], odata + olen,
1082 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1083 entry.class = sdata[0] << 8 | sdata[1];
1086 odhcp6c_update_entry(STATE_IA_NA, &entry);
1094 static int dhcpv6_calc_refresh_timers(void)
1096 struct odhcp6c_entry *e;
1097 size_t ia_na_entries, ia_pd_entries, i;
1098 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1100 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1101 ia_na_entries /= sizeof(*e);
1102 for (i = 0; i < ia_na_entries; i++) {
1109 if (e[i].valid > l_t3)
1113 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1114 ia_pd_entries /= sizeof(*e);
1115 for (i = 0; i < ia_pd_entries; i++) {
1122 if (e[i].valid > l_t3)
1126 if (ia_pd_entries || ia_na_entries) {
1132 return (int)(ia_pd_entries + ia_na_entries);
1136 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1137 const void *status_msg, const int len)
1139 uint8_t buf[len + 3];
1141 memset(buf, 0, sizeof(buf));
1144 memcpy(&buf[1], status_msg, len);
1148 syslog(LOG_WARNING, "Server returned %s status %i %s",
1153 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1154 const uint16_t code, const void *status_msg, const int len,
1157 dhcpv6_log_status_code(code, "message", status_msg, len);
1160 case DHCPV6_UnspecFail:
1165 case DHCPV6_UseMulticast:
1166 // TODO handle multicast status code
1169 case DHCPV6_NoAddrsAvail:
1170 case DHCPV6_NoPrefixAvail:
1171 if (orig == DHCPV6_MSG_REQUEST)
1172 *ret = 0; // Failure
1181 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1182 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1183 const void *status_msg, const int len,
1184 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1186 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1187 "IA_NA" : "IA_PD", status_msg, len);
1190 case DHCPV6_NoBinding:
1192 case DHCPV6_MSG_RENEW:
1193 case DHCPV6_MSG_REBIND:
1194 if ((*ret > 0) && !handled_status_codes[code])
1195 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1203 case DHCPV6_NoAddrsAvail:
1204 case DHCPV6_NoPrefixAvail:
1206 case DHCPV6_MSG_REQUEST:
1215 case DHCPV6_NotOnLink:
1216 // TODO handle not onlink in case of confirm