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
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
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);
54 static int dhcpv6_parse_ia(void *opt, void *end);
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,
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],
65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
66 static void dhcpv6_clear_all_server_cand(void);
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);
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},
97 static int ifindex = -1;
98 static int64_t t1 = 0, t2 = 0, t3 = 0;
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;
106 static uint8_t reconf_key[16];
109 static unsigned int client_options = 0;
112 int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout)
114 client_options = options;
115 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
117 sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
123 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
124 if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
126 ifindex = ifr.ifr_ifindex;
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};
135 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
136 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
138 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
139 struct ifreq ifs[100], *ifp, *ifend;
142 ifc.ifc_len = sizeof(ifs);
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)
155 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
160 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
164 if (!(client_options & DHCPV6_STRICT_OPTIONS)) {
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),
180 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
183 // Configure IPv6-options
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));
189 setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
190 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
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)
201 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
207 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
211 gethostname(fqdn_buf, sizeof(fqdn_buf));
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);
227 void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
231 void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
234 size_t ia_pd_entries, ia_pd_len = 0;
237 if (type == DHCPV6_MSG_SOLICIT) {
238 odhcp6c_clear_state(STATE_IA_PD);
240 struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes);
241 n_prefixes /= sizeof(struct odhcp6c_request_prefix);
243 ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix)));
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
251 struct dhcpv6_ia_prefix pref = {
252 .type = htons(DHCPV6_OPT_IA_PREFIX),
253 .len = htons(25), .prefix = request_prefixes[i].length
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);
261 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
262 ia_pd_entries /= sizeof(*e);
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)));
269 for (size_t i = 0; i < ia_pd_entries; ++i) {
270 uint32_t iaid = e[i].iaid;
272 // check if this is an unprocessed IAID and skip if not.
274 for (int j = i-1; j >= 0; j--) {
275 if (e[j].iaid == iaid) {
285 struct dhcpv6_ia_hdr hdr_ia_pd = {
286 htons(DHCPV6_OPT_IA_PD),
287 htons(sizeof(hdr_ia_pd) - 4),
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);
295 for (size_t j = i; j < ia_pd_entries; j++) {
296 if (e[j].iaid != iaid)
300 if (e[j].priority > 0)
301 ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6;
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,
310 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
311 ia_pd_len += sizeof(p);
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;
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);
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;
329 hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U);
334 if (ia_pd_entries > 0)
338 size_t ia_na_entries, ia_na_len = 0;
340 struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
341 ia_na_entries /= sizeof(*e);
343 struct dhcpv6_ia_hdr hdr_ia_na = {
344 htons(DHCPV6_OPT_IA_NA),
345 htons(sizeof(hdr_ia_na) - 4),
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;
359 ia_na_len = sizeof(pa);
360 hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
362 // Reconfigure Accept
366 } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
368 // Request Information Refresh
369 uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
371 // Build vendor-class option
372 size_t vendor_class_len;
373 struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
378 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
382 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
386 uint16_t elapsed_type;
387 uint16_t elapsed_len;
388 uint16_t elapsed_value;
392 type, {trid[0], trid[1], trid[2]},
393 htons(DHCPV6_OPT_ELAPSED), htons(2),
394 htons((ecs > 0xffff) ? 0xffff : ecs),
395 htons(DHCPV6_OPT_ORO), htons(oro_len),
398 struct iovec iov[] = {
403 {srv_id, srv_id_len},
404 {&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
405 {vendor_class, vendor_class_len},
406 {&reconf_accept, sizeof(reconf_accept)},
408 {&hdr_ia_na, sizeof(hdr_ia_na)},
413 size_t cnt = ARRAY_SIZE(iov);
414 if (type == DHCPV6_MSG_INFO_REQ) {
416 iov[2].iov_len = sizeof(oro_refresh);
417 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
418 } else if (!request_prefix) {
422 // Disable IAs if not used
423 if (type != DHCPV6_MSG_SOLICIT) {
429 if (na_mode == IA_MODE_NONE)
432 if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
435 if (!(client_options & DHCPV6_CLIENT_FQDN))
438 struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
439 0, ALL_DHCPV6_RELAYS, ifindex};
440 struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
442 sendmsg(sock, &msg, 0);
446 static int64_t dhcpv6_rand_delay(int64_t time)
449 odhcp6c_random(&random, sizeof(random));
450 return (time * ((int64_t)random % 1000LL)) / 10000LL;
454 int dhcpv6_request(enum dhcpv6_msg type)
457 uint64_t timeout = UINT32_MAX;
458 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
461 struct timespec ts = {0, 0};
462 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
463 nanosleep(&ts, NULL);
466 if (type == DHCPV6_MSG_UNKNOWN)
468 else if (type == DHCPV6_MSG_RENEW)
469 timeout = (t2 > t1) ? t2 - t1 : 0;
470 else if (type == DHCPV6_MSG_REBIND)
471 timeout = (t3 > t2) ? t3 - t2 : 0;
476 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
477 retx->name, (unsigned long long)timeout, retx->max_rc);
479 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
481 // Generate transaction ID
482 uint8_t trid[3] = {0, 0, 0};
483 if (type != DHCPV6_MSG_UNKNOWN)
484 odhcp6c_random(trid, sizeof(trid));
490 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
492 // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
493 while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
494 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
496 rto = (retx->init_timeo * 1000 + delay);
499 rto = (2 * rto + dhcpv6_rand_delay(rto));
501 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
502 rto = retx->max_timeo * 1000 +
503 dhcpv6_rand_delay(retx->max_timeo * 1000);
505 // Calculate end for this round and elapsed time
506 uint64_t round_end = round_start + rto;
507 elapsed = round_start - start;
509 // Don't wait too long
510 if (round_end - start > timeout * 1000)
511 round_end = timeout * 1000 + start;
513 // Built and send package
514 if (type != DHCPV6_MSG_UNKNOWN) {
515 if (type != DHCPV6_MSG_SOLICIT)
516 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
517 retx->name, (unsigned long long)elapsed, rc);
518 dhcpv6_send(type, trid, elapsed / 10);
523 for (; len < 0 && (round_start < round_end);
524 round_start = odhcp6c_get_milli_time()) {
525 uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
526 struct iovec iov = {buf, sizeof(buf)};
527 struct msghdr msg = {NULL, 0, &iov, 1,
528 cmsg_buf, sizeof(cmsg_buf), 0};
529 struct in6_pktinfo *pktinfo = NULL;
531 // Check for pending signal
532 if (odhcp6c_signal_process())
535 // Set timeout for receiving
536 uint64_t t = round_end - round_start;
537 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
538 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
539 &timeout, sizeof(timeout));
542 len = recvmsg(sock, &msg, 0);
546 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
547 ch = CMSG_NXTHDR(&msg, ch)) {
548 if (ch->cmsg_level == SOL_IPV6 &&
549 ch->cmsg_type == IPV6_PKTINFO) {
550 pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
555 if (pktinfo == NULL) {
560 if (!dhcpv6_response_is_valid(buf, len, trid,
561 type, &pktinfo->ipi6_addr)) {
566 uint8_t *opt = &buf[4];
567 uint8_t *opt_end = opt + len - 4;
569 round_start = odhcp6c_get_milli_time();
570 elapsed = round_start - start;
571 syslog(LOG_NOTICE, "Got a valid reply after "
572 "%llums", (unsigned long long)elapsed);
574 if (retx->handler_reply)
575 len = retx->handler_reply(type, rc, opt, opt_end);
577 if (len > 0 && round_end - round_start > 1000)
578 round_end = 1000 + round_start;
582 if (retx->handler_finish)
583 len = retx->handler_finish();
584 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
589 // Message validation checks according to RFC3315 chapter 15
590 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
591 const uint8_t transaction[3], enum dhcpv6_msg type,
592 const struct in6_addr *daddr)
594 const struct dhcpv6_header *rep = buf;
595 if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
596 transaction, sizeof(rep->tr_id)))
597 return false; // Invalid reply
599 if (type == DHCPV6_MSG_SOLICIT) {
600 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
601 rep->msg_type != DHCPV6_MSG_REPLY)
603 } else if (type == DHCPV6_MSG_UNKNOWN) {
604 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
606 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
610 uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
611 rcmsg = DHCPV6_MSG_UNKNOWN;
612 uint16_t otype, olen = UINT16_MAX;
613 bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
614 ia_present = false, options_valid = true;
616 size_t client_id_len, server_id_len;
617 void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
618 void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
620 dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
621 if (otype == DHCPV6_OPT_CLIENTID) {
622 clientid_ok = (olen + 4U == client_id_len) && !memcmp(
623 &odata[-4], client_id, client_id_len);
624 } else if (otype == DHCPV6_OPT_SERVERID) {
626 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
627 &odata[-4], server_id, server_id_len);
630 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
631 sizeof(struct dhcpv6_auth_reconfigure)) {
632 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
633 if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
637 uint8_t serverhash[16], secretbytes[16], hash[16];
638 memcpy(serverhash, r->key, sizeof(serverhash));
639 memset(r->key, 0, sizeof(r->key));
640 memcpy(secretbytes, reconf_key, sizeof(secretbytes));
642 for (size_t i = 0; i < sizeof(secretbytes); ++i)
643 secretbytes[i] ^= 0x36;
646 md5_hash(secretbytes, sizeof(secretbytes), &md5);
647 md5_hash(buf, len, &md5);
650 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
651 secretbytes[i] ^= 0x36;
652 secretbytes[i] ^= 0x5c;
656 md5_hash(secretbytes, sizeof(secretbytes), &md5);
657 md5_hash(hash, 16, &md5);
660 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
661 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
663 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
665 if (olen < sizeof(struct dhcpv6_ia_hdr))
666 options_valid = false;
668 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
669 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
670 // Options are not allowed on global level
671 options_valid = false;
675 if (!options_valid || ((odata + olen) > end))
678 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
681 if (rep->msg_type == DHCPV6_MSG_RECONF) {
682 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
683 (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
684 !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
688 return clientid_ok && serverid_ok;
692 int dhcpv6_poll_reconfigure(void)
694 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
696 ret = dhcpv6_request(ret);
702 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
703 const void *opt, const void *end)
705 uint16_t otype, olen;
706 uint8_t *odata, msg = DHCPV6_MSG_RENEW;
707 dhcpv6_for_each_option(opt, end, otype, olen, odata)
708 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
709 odata[0] == DHCPV6_MSG_RENEW ||
710 odata[0] == DHCPV6_MSG_INFO_REQ))
713 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
718 // Collect all advertised servers
719 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
720 const void *opt, const void *end)
722 uint16_t olen, otype;
723 uint8_t *odata, pref = 0;
724 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
726 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
727 bool have_na = false;
730 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
731 if (orig == DHCPV6_MSG_SOLICIT &&
732 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
733 olen > sizeof(struct dhcpv6_ia_hdr)) {
734 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
735 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
738 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
739 memcpy(cand.duid, odata, olen);
740 cand.duid_len = olen;
741 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
742 int error = ((int)odata[0] << 8 | (int)odata[1]);
745 case DHCPV6_NoPrefixAvail:
746 // Status code on global level
747 cand.preference -= 2000;
753 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
754 cand.preference >= 0) {
755 cand.preference = pref = odata[0];
756 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
757 cand.wants_reconfigure = true;
758 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
759 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
760 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
761 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
762 cand.sol_max_rt = sol_max_rt;
763 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
764 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
765 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
766 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
767 cand.inf_max_rt = inf_max_rt;
768 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
769 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
770 uint8_t *oend = odata + olen, *d;
771 dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
772 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
773 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
774 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
778 } else if (otype == DHCPV6_OPT_IA_NA) {
779 struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
780 uint8_t *oend = odata + olen, *d;
781 dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
782 if (otype == DHCPV6_OPT_IA_ADDR)
787 if ((!have_na && na_mode == IA_MODE_FORCE) ||
788 (!have_pd && pd_mode == IA_MODE_FORCE)) {
790 * RFC7083 states to process the SOL_MAX_RT and
791 * INF_MAX_RT options even if the DHCPv6 server
792 * did not propose any IA_NA and/or IA_PD
794 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
795 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
799 if (na_mode != IA_MODE_NONE && !have_na) {
800 cand.has_noaddravail = true;
801 cand.preference -= 1000;
804 if (pd_mode != IA_MODE_NONE) {
806 cand.preference += 2000 + (128 - have_pd);
808 cand.preference -= 2000;
811 if (cand.duid_len > 0) {
812 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
813 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
814 dhcpv6_add_server_cand(&cand);
817 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
821 static int dhcpv6_commit_advert(void)
823 return dhcpv6_promote_server_cand();
827 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
828 const void *opt, const void *end)
830 dhcpv6_handle_advert(orig, rc, opt, end);
831 if (dhcpv6_commit_advert() < 0)
834 return dhcpv6_handle_reply(orig, rc, opt, end);
838 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
839 const void *opt, const void *end)
842 uint16_t otype, olen;
843 uint32_t refresh = UINT32_MAX;
845 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
849 if (orig == DHCPV6_MSG_UNKNOWN) {
850 static time_t last_update = 0;
851 time_t now = odhcp6c_get_milli_time() / 1000;
853 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
870 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
871 // Delete NA and PD we have in the state from the Advert
872 odhcp6c_clear_state(STATE_IA_NA);
873 odhcp6c_clear_state(STATE_IA_PD);
877 odhcp6c_clear_state(STATE_DNS);
878 odhcp6c_clear_state(STATE_SEARCH);
879 odhcp6c_clear_state(STATE_SNTP_IP);
880 odhcp6c_clear_state(STATE_NTP_IP);
881 odhcp6c_clear_state(STATE_NTP_FQDN);
882 odhcp6c_clear_state(STATE_SIP_IP);
883 odhcp6c_clear_state(STATE_SIP_FQDN);
884 odhcp6c_clear_state(STATE_AFTR_NAME);
887 // Parse and find all matching IAs
888 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
889 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
890 && olen > sizeof(struct dhcpv6_ia_hdr)) {
891 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
894 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
897 uint16_t code = DHCPV6_Success;
898 uint16_t stype, slen;
900 // Get and handle status code
901 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
902 stype, slen, sdata) {
903 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
904 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
905 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
907 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
909 if (code == DHCPV6_Success)
912 dhcpv6_handle_ia_status_code(orig, ia_hdr,
913 code, mdata, mlen, handled_status_codes, &ret);
922 if (code != DHCPV6_Success)
925 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
926 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
927 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
928 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
929 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
931 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
933 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
935 odhcp6c_add_state(STATE_DNS, odata, olen);
936 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
937 odhcp6c_add_state(STATE_SEARCH, odata, olen);
938 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
940 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
941 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
942 uint16_t stype, slen;
944 // Test status and bail if error
945 dhcpv6_for_each_option(odata, odata + olen,
946 stype, slen, sdata) {
947 if (slen == 16 && (stype == NTP_MC_ADDR ||
948 stype == NTP_SRV_ADDR))
949 odhcp6c_add_state(STATE_NTP_IP,
951 else if (slen > 0 && stype == NTP_SRV_FQDN)
952 odhcp6c_add_state(STATE_NTP_FQDN,
955 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
957 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
958 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
959 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
960 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
961 refresh = ntohl(*((uint32_t*)odata));
962 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
963 sizeof(struct dhcpv6_auth_reconfigure)) {
964 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
965 if (r->protocol == 3 && r->algorithm == 1 &&
967 memcpy(reconf_key, r->key, sizeof(r->key));
968 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
970 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
972 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
973 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
974 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
975 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
976 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
977 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
978 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
979 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
980 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
981 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
982 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
983 }else if (otype != DHCPV6_OPT_CLIENTID &&
984 otype != DHCPV6_OPT_SERVERID) {
985 odhcp6c_add_state(STATE_CUSTOM_OPTS,
986 &odata[-4], olen + 4);
990 if (orig != DHCPV6_MSG_INFO_REQ) {
991 // Update refresh timers if no fatal status code was received
992 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
994 case DHCPV6_MSG_RENEW:
995 // Send further renews if T1 is not set
999 case DHCPV6_MSG_REBIND:
1000 // Send further rebinds if T1 and T2 is not set
1005 case DHCPV6_MSG_REQUEST:
1006 // All server candidates can be cleared if not yet bound
1007 if (!odhcp6c_is_bound())
1008 dhcpv6_clear_all_server_cand();
1016 // All server candidates can be cleared if not yet bound
1017 if (!odhcp6c_is_bound())
1018 dhcpv6_clear_all_server_cand();
1027 static int dhcpv6_parse_ia(void *opt, void *end)
1029 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1032 uint16_t otype, olen;
1035 t1 = ntohl(ia_hdr->t1);
1036 t2 = ntohl(ia_hdr->t2);
1041 // Update address IA
1042 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1043 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1044 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1046 entry.iaid = ia_hdr->iaid;
1048 if (otype == DHCPV6_OPT_IA_PREFIX) {
1049 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1050 if (olen + 4U < sizeof(*prefix))
1053 entry.valid = ntohl(prefix->valid);
1054 entry.preferred = ntohl(prefix->preferred);
1056 if (entry.preferred > entry.valid)
1059 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1060 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1061 if (entry.t1 > entry.t2)
1062 entry.t1 = entry.t2;
1064 entry.length = prefix->prefix;
1065 entry.target = prefix->addr;
1066 uint16_t stype, slen;
1069 #ifdef EXT_PREFIX_CLASS
1070 // Find prefix class, if any
1071 dhcpv6_for_each_option(&prefix[1], odata + olen,
1073 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1074 entry.class = sdata[0] << 8 | sdata[1];
1079 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1080 odata + olen, stype, slen, sdata) {
1081 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1084 uint8_t elen = sdata[0];
1088 if (elen <= 32 || elen <= entry.length) {
1094 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1095 if (slen <= bytes) {
1100 uint32_t exclude = 0;
1102 exclude = exclude << 8 | sdata[bytes];
1105 exclude >>= 8 - ((elen - entry.length) % 8);
1106 exclude <<= 64 - elen;
1108 // Abusing router & priority fields for exclusion
1109 entry.router = entry.target;
1110 entry.router.s6_addr32[1] |= htonl(exclude);
1111 entry.priority = elen;
1115 odhcp6c_update_entry(STATE_IA_PD, &entry);
1120 memset(&entry.router, 0, sizeof(entry.router));
1121 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1122 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1123 if (olen + 4U < sizeof(*addr))
1126 entry.preferred = ntohl(addr->preferred);
1127 entry.valid = ntohl(addr->valid);
1129 if (entry.preferred > entry.valid)
1132 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1133 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1134 if (entry.t1 > entry.t2)
1135 entry.t1 = entry.t2;
1138 entry.target = addr->addr;
1140 #ifdef EXT_PREFIX_CLASS
1141 uint16_t stype, slen;
1143 // Find prefix class, if any
1144 dhcpv6_for_each_option(&addr[1], odata + olen,
1146 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1147 entry.class = sdata[0] << 8 | sdata[1];
1150 odhcp6c_update_entry(STATE_IA_NA, &entry);
1158 static int dhcpv6_calc_refresh_timers(void)
1160 struct odhcp6c_entry *e;
1161 size_t ia_na_entries, ia_pd_entries, i;
1162 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1164 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1165 ia_na_entries /= sizeof(*e);
1166 for (i = 0; i < ia_na_entries; i++) {
1173 if (e[i].valid > l_t3)
1177 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1178 ia_pd_entries /= sizeof(*e);
1179 for (i = 0; i < ia_pd_entries; i++) {
1186 if (e[i].valid > l_t3)
1190 if (ia_pd_entries || ia_na_entries) {
1198 return (int)(ia_pd_entries + ia_na_entries);
1202 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1203 const void *status_msg, const int len)
1205 uint8_t buf[len + 3];
1207 memset(buf, 0, sizeof(buf));
1210 memcpy(&buf[1], status_msg, len);
1214 syslog(LOG_WARNING, "Server returned %s status %i %s",
1219 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1220 const uint16_t code, const void *status_msg, const int len,
1223 dhcpv6_log_status_code(code, "message", status_msg, len);
1226 case DHCPV6_UnspecFail:
1231 case DHCPV6_UseMulticast:
1232 // TODO handle multicast status code
1235 case DHCPV6_NoAddrsAvail:
1236 case DHCPV6_NoPrefixAvail:
1237 if (orig == DHCPV6_MSG_REQUEST)
1238 *ret = 0; // Failure
1247 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1248 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1249 const void *status_msg, const int len,
1250 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1252 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1253 "IA_NA" : "IA_PD", status_msg, len);
1256 case DHCPV6_NoBinding:
1258 case DHCPV6_MSG_RENEW:
1259 case DHCPV6_MSG_REBIND:
1260 if ((*ret > 0) && !handled_status_codes[code])
1261 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1269 case DHCPV6_NoAddrsAvail:
1270 case DHCPV6_NoPrefixAvail:
1272 case DHCPV6_MSG_REQUEST:
1281 case DHCPV6_NotOnLink:
1282 // TODO handle not onlink in case of confirm
1290 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1293 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1295 // Remove identical duid server candidate
1296 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1297 if (cand->duid_len == c[i].duid_len &&
1298 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1301 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1306 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1307 i < cand_len / sizeof(*c); ++i) {
1308 if (c[i].preference < cand->preference)
1312 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1315 static void dhcpv6_clear_all_server_cand(void)
1318 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1320 // Server candidates need deep delete for IA_NA/IA_PD
1321 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1325 odhcp6c_clear_state(STATE_SERVER_CAND);
1328 int dhcpv6_promote_server_cand(void)
1331 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1333 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1334 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1336 // Clear lingering candidate state info
1337 odhcp6c_clear_state(STATE_SERVER_ID);
1338 odhcp6c_clear_state(STATE_IA_NA);
1339 odhcp6c_clear_state(STATE_IA_PD);
1344 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1345 na_mode = IA_MODE_NONE;
1347 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1348 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1350 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1353 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1354 hdr[1] = htons(cand->duid_len);
1355 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1356 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1357 accept_reconfig = cand->wants_reconfigure;
1358 if (cand->ia_na_len) {
1359 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1361 if (na_mode != IA_MODE_NONE)
1362 ret = DHCPV6_STATEFUL;
1364 if (cand->ia_pd_len) {
1365 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1368 ret = DHCPV6_STATEFUL;
1371 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1372 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1374 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));