2 * Copyright (C) 2012-2014 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, 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);
379 } vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
384 } user_class_hdr = {htons(DHCPV6_OPT_USER_CLASS), htons(user_class_len)};
388 void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
392 uint16_t elapsed_type;
393 uint16_t elapsed_len;
394 uint16_t elapsed_value;
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),
404 struct iovec iov[] = {
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)},
416 {&hdr_ia_na, sizeof(hdr_ia_na)},
421 size_t cnt = ARRAY_SIZE(iov);
422 if (type == DHCPV6_MSG_INFO_REQ) {
424 iov[2].iov_len = sizeof(oro_refresh);
425 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
426 } else if (!request_prefix) {
430 // Disable IAs if not used
431 if (type != DHCPV6_MSG_SOLICIT) {
437 if (na_mode == IA_MODE_NONE)
440 if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
443 if (!(client_options & DHCPV6_CLIENT_FQDN))
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};
450 sendmsg(sock, &msg, 0);
454 static int64_t dhcpv6_rand_delay(int64_t time)
457 odhcp6c_random(&random, sizeof(random));
458 return (time * ((int64_t)random % 1000LL)) / 10000LL;
462 int dhcpv6_request(enum dhcpv6_msg type)
465 uint64_t timeout = UINT32_MAX;
466 struct dhcpv6_retx *retx = &dhcpv6_retx[type];
469 struct timespec ts = {0, 0};
470 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
471 nanosleep(&ts, NULL);
474 if (type == DHCPV6_MSG_UNKNOWN)
476 else if (type == DHCPV6_MSG_RENEW)
477 timeout = (t2 > t1) ? t2 - t1 : 0;
478 else if (type == DHCPV6_MSG_REBIND)
479 timeout = (t3 > t2) ? t3 - t2 : 0;
484 syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
485 retx->name, (unsigned long long)timeout, retx->max_rc);
487 uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
489 // Generate transaction ID
490 uint8_t trid[3] = {0, 0, 0};
491 if (type != DHCPV6_MSG_UNKNOWN)
492 odhcp6c_random(trid, sizeof(trid));
498 int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
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);
504 rto = (retx->init_timeo * 1000 + delay);
507 rto = (2 * rto + dhcpv6_rand_delay(rto));
509 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
510 rto = retx->max_timeo * 1000 +
511 dhcpv6_rand_delay(retx->max_timeo * 1000);
513 // Calculate end for this round and elapsed time
514 uint64_t round_end = round_start + rto;
515 elapsed = round_start - start;
517 // Don't wait too long
518 if (round_end - start > timeout * 1000)
519 round_end = timeout * 1000 + start;
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);
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;
539 // Check for pending signal
540 if (odhcp6c_signal_process())
543 // Set timeout for receiving
544 uint64_t t = round_end - round_start;
545 struct timeval timeout = {t / 1000, (t % 1000) * 1000};
546 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
547 &timeout, sizeof(timeout));
550 len = recvmsg(sock, &msg, 0);
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);
563 if (pktinfo == NULL) {
568 if (!dhcpv6_response_is_valid(buf, len, trid,
569 type, &pktinfo->ipi6_addr)) {
574 uint8_t *opt = &buf[4];
575 uint8_t *opt_end = opt + len - 4;
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);
582 if (retx->handler_reply)
583 len = retx->handler_reply(type, rc, opt, opt_end);
585 if (len > 0 && round_end - round_start > 1000)
586 round_end = 1000 + round_start;
590 if (retx->handler_finish)
591 len = retx->handler_finish();
592 } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
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)
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
607 if (type == DHCPV6_MSG_SOLICIT) {
608 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
609 rep->msg_type != DHCPV6_MSG_REPLY)
611 } else if (type == DHCPV6_MSG_UNKNOWN) {
612 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
614 } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
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;
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);
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) {
634 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
635 &odata[-4], server_id, server_id_len);
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)
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));
650 for (size_t i = 0; i < sizeof(secretbytes); ++i)
651 secretbytes[i] ^= 0x36;
654 md5_hash(secretbytes, sizeof(secretbytes), &md5);
655 md5_hash(buf, len, &md5);
658 for (size_t i = 0; i < sizeof(secretbytes); ++i) {
659 secretbytes[i] ^= 0x36;
660 secretbytes[i] ^= 0x5c;
664 md5_hash(secretbytes, sizeof(secretbytes), &md5);
665 md5_hash(hash, 16, &md5);
668 rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
669 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
671 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
673 if (olen < sizeof(struct dhcpv6_ia_hdr))
674 options_valid = false;
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;
683 if (!options_valid || ((odata + olen) > end))
686 if (type == DHCPV6_MSG_INFO_REQ && ia_present)
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))
696 return clientid_ok && serverid_ok;
700 int dhcpv6_poll_reconfigure(void)
702 int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
704 ret = dhcpv6_request(ret);
710 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
711 const void *opt, const void *end)
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))
721 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
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)
730 uint16_t olen, otype;
731 uint8_t *odata, pref = 0;
732 struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
734 DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
735 bool have_na = false;
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));
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]);
753 case DHCPV6_NoPrefixAvail:
754 // Status code on global level
755 cand.preference -= 2000;
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];
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)
795 if ((!have_na && na_mode == IA_MODE_FORCE) ||
796 (!have_pd && pd_mode == IA_MODE_FORCE)) {
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
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;
807 if (na_mode != IA_MODE_NONE && !have_na) {
808 cand.has_noaddravail = true;
809 cand.preference -= 1000;
812 if (pd_mode != IA_MODE_NONE) {
814 cand.preference += 2000 + (128 - have_pd);
816 cand.preference -= 2000;
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);
825 return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
829 static int dhcpv6_commit_advert(void)
831 return dhcpv6_promote_server_cand();
835 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
836 const void *opt, const void *end)
838 dhcpv6_handle_advert(orig, rc, opt, end);
839 if (dhcpv6_commit_advert() < 0)
842 return dhcpv6_handle_reply(orig, rc, opt, end);
846 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
847 const void *opt, const void *end)
850 uint16_t otype, olen;
851 uint32_t refresh = UINT32_MAX;
853 bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
857 if (orig == DHCPV6_MSG_UNKNOWN) {
858 static time_t last_update = 0;
859 time_t now = odhcp6c_get_milli_time() / 1000;
861 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
878 if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
879 // Delete NA and PD we have in the state from the Advert
880 odhcp6c_clear_state(STATE_IA_NA);
881 odhcp6c_clear_state(STATE_IA_PD);
885 odhcp6c_clear_state(STATE_DNS);
886 odhcp6c_clear_state(STATE_SEARCH);
887 odhcp6c_clear_state(STATE_SNTP_IP);
888 odhcp6c_clear_state(STATE_NTP_IP);
889 odhcp6c_clear_state(STATE_NTP_FQDN);
890 odhcp6c_clear_state(STATE_SIP_IP);
891 odhcp6c_clear_state(STATE_SIP_FQDN);
892 odhcp6c_clear_state(STATE_AFTR_NAME);
895 // Parse and find all matching IAs
896 dhcpv6_for_each_option(opt, end, otype, olen, odata) {
897 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
898 && olen > sizeof(struct dhcpv6_ia_hdr)) {
899 struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
902 if (ia_hdr->iaid != 1 && otype == DHCPV6_OPT_IA_NA)
905 uint16_t code = DHCPV6_Success;
906 uint16_t stype, slen;
908 // Get and handle status code
909 dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
910 stype, slen, sdata) {
911 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
912 uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
913 uint16_t mlen = (slen > 2) ? slen - 2 : 0;
915 code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
917 if (code == DHCPV6_Success)
920 dhcpv6_handle_ia_status_code(orig, ia_hdr,
921 code, mdata, mlen, handled_status_codes, &ret);
930 if (code != DHCPV6_Success)
933 dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
934 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
935 uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
936 uint16_t mlen = (olen > 2) ? olen - 2 : 0;
937 uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
939 dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
941 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
943 odhcp6c_add_state(STATE_DNS, odata, olen);
944 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
945 odhcp6c_add_state(STATE_SEARCH, odata, olen);
946 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
948 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
949 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
950 uint16_t stype, slen;
952 // Test status and bail if error
953 dhcpv6_for_each_option(odata, odata + olen,
954 stype, slen, sdata) {
955 if (slen == 16 && (stype == NTP_MC_ADDR ||
956 stype == NTP_SRV_ADDR))
957 odhcp6c_add_state(STATE_NTP_IP,
959 else if (slen > 0 && stype == NTP_SRV_FQDN)
960 odhcp6c_add_state(STATE_NTP_FQDN,
963 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
965 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
966 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
967 odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
968 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
969 refresh = ntohl(*((uint32_t*)odata));
970 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
971 sizeof(struct dhcpv6_auth_reconfigure)) {
972 struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
973 if (r->protocol == 3 && r->algorithm == 1 &&
975 memcpy(reconf_key, r->key, sizeof(r->key));
976 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
978 odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
980 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
981 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
982 uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
983 if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
984 sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
985 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
986 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
987 uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
988 if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
989 inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
990 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
991 }else if (otype != DHCPV6_OPT_CLIENTID &&
992 otype != DHCPV6_OPT_SERVERID) {
993 odhcp6c_add_state(STATE_CUSTOM_OPTS,
994 &odata[-4], olen + 4);
998 if (orig != DHCPV6_MSG_INFO_REQ) {
999 // Update refresh timers if no fatal status code was received
1000 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
1002 case DHCPV6_MSG_RENEW:
1003 // Send further renews if T1 is not set
1007 case DHCPV6_MSG_REBIND:
1008 // Send further rebinds if T1 and T2 is not set
1013 case DHCPV6_MSG_REQUEST:
1014 // All server candidates can be cleared if not yet bound
1015 if (!odhcp6c_is_bound())
1016 dhcpv6_clear_all_server_cand();
1024 // All server candidates can be cleared if not yet bound
1025 if (!odhcp6c_is_bound())
1026 dhcpv6_clear_all_server_cand();
1035 static int dhcpv6_parse_ia(void *opt, void *end)
1037 struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1040 uint16_t otype, olen;
1043 t1 = ntohl(ia_hdr->t1);
1044 t2 = ntohl(ia_hdr->t2);
1049 // Update address IA
1050 dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1051 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1052 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
1054 entry.iaid = ia_hdr->iaid;
1056 if (otype == DHCPV6_OPT_IA_PREFIX) {
1057 struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1058 if (olen + 4U < sizeof(*prefix))
1061 entry.valid = ntohl(prefix->valid);
1062 entry.preferred = ntohl(prefix->preferred);
1064 if (entry.preferred > entry.valid)
1067 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1068 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1069 if (entry.t1 > entry.t2)
1070 entry.t1 = entry.t2;
1072 entry.length = prefix->prefix;
1073 entry.target = prefix->addr;
1074 uint16_t stype, slen;
1077 #ifdef EXT_PREFIX_CLASS
1078 // Find prefix class, if any
1079 dhcpv6_for_each_option(&prefix[1], odata + olen,
1081 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1082 entry.class = sdata[0] << 8 | sdata[1];
1087 dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1088 odata + olen, stype, slen, sdata) {
1089 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1092 uint8_t elen = sdata[0];
1096 if (elen <= 32 || elen <= entry.length) {
1102 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1103 if (slen <= bytes) {
1108 uint32_t exclude = 0;
1110 exclude = exclude << 8 | sdata[bytes];
1113 exclude >>= 8 - ((elen - entry.length) % 8);
1114 exclude <<= 64 - elen;
1116 // Abusing router & priority fields for exclusion
1117 entry.router = entry.target;
1118 entry.router.s6_addr32[1] |= htonl(exclude);
1119 entry.priority = elen;
1123 odhcp6c_update_entry(STATE_IA_PD, &entry);
1128 memset(&entry.router, 0, sizeof(entry.router));
1129 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1130 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1131 if (olen + 4U < sizeof(*addr))
1134 entry.preferred = ntohl(addr->preferred);
1135 entry.valid = ntohl(addr->valid);
1137 if (entry.preferred > entry.valid)
1140 entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1141 entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1142 if (entry.t1 > entry.t2)
1143 entry.t1 = entry.t2;
1146 entry.target = addr->addr;
1148 #ifdef EXT_PREFIX_CLASS
1149 uint16_t stype, slen;
1151 // Find prefix class, if any
1152 dhcpv6_for_each_option(&addr[1], odata + olen,
1154 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1155 entry.class = sdata[0] << 8 | sdata[1];
1158 odhcp6c_update_entry(STATE_IA_NA, &entry);
1166 static int dhcpv6_calc_refresh_timers(void)
1168 struct odhcp6c_entry *e;
1169 size_t ia_na_entries, ia_pd_entries, i;
1170 int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1172 e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1173 ia_na_entries /= sizeof(*e);
1174 for (i = 0; i < ia_na_entries; i++) {
1181 if (e[i].valid > l_t3)
1185 e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1186 ia_pd_entries /= sizeof(*e);
1187 for (i = 0; i < ia_pd_entries; i++) {
1194 if (e[i].valid > l_t3)
1198 if (ia_pd_entries || ia_na_entries) {
1206 return (int)(ia_pd_entries + ia_na_entries);
1210 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1211 const void *status_msg, const int len)
1213 uint8_t buf[len + 3];
1215 memset(buf, 0, sizeof(buf));
1218 memcpy(&buf[1], status_msg, len);
1222 syslog(LOG_WARNING, "Server returned %s status %i %s",
1227 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1228 const uint16_t code, const void *status_msg, const int len,
1231 dhcpv6_log_status_code(code, "message", status_msg, len);
1234 case DHCPV6_UnspecFail:
1239 case DHCPV6_UseMulticast:
1240 // TODO handle multicast status code
1243 case DHCPV6_NoAddrsAvail:
1244 case DHCPV6_NoPrefixAvail:
1245 if (orig == DHCPV6_MSG_REQUEST)
1246 *ret = 0; // Failure
1255 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1256 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1257 const void *status_msg, const int len,
1258 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1260 dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1261 "IA_NA" : "IA_PD", status_msg, len);
1264 case DHCPV6_NoBinding:
1266 case DHCPV6_MSG_RENEW:
1267 case DHCPV6_MSG_REBIND:
1268 if ((*ret > 0) && !handled_status_codes[code])
1269 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1277 case DHCPV6_NoAddrsAvail:
1278 case DHCPV6_NoPrefixAvail:
1280 case DHCPV6_MSG_REQUEST:
1289 case DHCPV6_NotOnLink:
1290 // TODO handle not onlink in case of confirm
1298 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1301 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1303 // Remove identical duid server candidate
1304 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1305 if (cand->duid_len == c[i].duid_len &&
1306 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1309 odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1314 for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1315 i < cand_len / sizeof(*c); ++i) {
1316 if (c[i].preference < cand->preference)
1320 odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1323 static void dhcpv6_clear_all_server_cand(void)
1326 struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1328 // Server candidates need deep delete for IA_NA/IA_PD
1329 for (i = 0; i < cand_len / sizeof(*c); ++i) {
1333 odhcp6c_clear_state(STATE_SERVER_CAND);
1336 int dhcpv6_promote_server_cand(void)
1339 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1341 int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1342 DHCPV6_STATELESS : DHCPV6_STATEFUL;
1344 // Clear lingering candidate state info
1345 odhcp6c_clear_state(STATE_SERVER_ID);
1346 odhcp6c_clear_state(STATE_IA_NA);
1347 odhcp6c_clear_state(STATE_IA_PD);
1352 if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1353 na_mode = IA_MODE_NONE;
1355 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1356 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1358 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1361 hdr[0] = htons(DHCPV6_OPT_SERVERID);
1362 hdr[1] = htons(cand->duid_len);
1363 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1364 odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1365 accept_reconfig = cand->wants_reconfigure;
1366 if (cand->ia_na_len) {
1367 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1369 if (na_mode != IA_MODE_NONE)
1370 ret = DHCPV6_STATEFUL;
1372 if (cand->ia_pd_len) {
1373 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1376 ret = DHCPV6_STATEFUL;
1379 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1380 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1382 odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));