2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
3 * Copyright (C) 2018 Hans Dedecker <dedeckeh@gmail.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License v2 as published by
7 * the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
24 #include <arpa/inet.h>
25 #include <net/route.h>
27 #include <libubox/utils.h>
33 static void forward_router_solicitation(const struct interface *iface);
34 static void forward_router_advertisement(const struct interface *iface, uint8_t *data, size_t len);
36 static void handle_icmpv6(void *addr, void *data, size_t len,
37 struct interface *iface, void *dest);
38 static void trigger_router_advert(struct uloop_timeout *event);
39 static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info);
41 static struct netevent_handler router_netevent_handler = { .cb = router_netevent_cb, };
43 static FILE *fp_route = NULL;
46 #define TIME_LEFT(t1, now) ((t1) != UINT32_MAX ? (t1) - (now) : UINT32_MAX)
52 if (!(fp_route = fopen("/proc/net/ipv6_route", "r"))) {
53 syslog(LOG_ERR, "fopen(/proc/net/ipv6_route): %m");
58 if (netlink_add_netevent_handler(&router_netevent_handler) < 0) {
59 syslog(LOG_ERR, "Failed to add netevent handler");
64 if (ret < 0 && fp_route) {
73 int router_setup_interface(struct interface *iface, bool enable)
77 enable = enable && (iface->ra != MODE_DISABLED);
85 if (!enable && iface->router_event.uloop.fd >= 0) {
87 uloop_timeout_cancel(&iface->timer_rs);
88 iface->timer_rs.cb = NULL;
90 trigger_router_advert(&iface->timer_rs);
93 uloop_fd_delete(&iface->router_event.uloop);
94 close(iface->router_event.uloop.fd);
95 iface->router_event.uloop.fd = -1;
97 struct icmp6_filter filt;
98 struct ipv6_mreq mreq;
101 if (iface->router_event.uloop.fd < 0) {
102 /* Open ICMPv6 socket */
103 iface->router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC,
105 if (iface->router_event.uloop.fd < 0) {
106 syslog(LOG_ERR, "socket(AF_INET6): %m");
111 if (setsockopt(iface->router_event.uloop.fd, SOL_SOCKET, SO_BINDTODEVICE,
112 iface->ifname, strlen(iface->ifname)) < 0) {
113 syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
118 /* Let the kernel compute our checksums */
119 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
120 &val, sizeof(val)) < 0) {
121 syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
126 /* This is required by RFC 4861 */
128 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
129 &val, sizeof(val)) < 0) {
130 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
135 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
136 &val, sizeof(val)) < 0) {
137 syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
142 /* We need to know the source interface */
144 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
145 &val, sizeof(val)) < 0) {
146 syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
151 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
152 &val, sizeof(val)) < 0) {
153 syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
158 /* Don't loop back */
160 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
161 &val, sizeof(val)) < 0) {
162 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
167 /* Filter ICMPv6 package types */
168 ICMP6_FILTER_SETBLOCKALL(&filt);
169 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
170 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
171 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
172 &filt, sizeof(filt)) < 0) {
173 syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
178 iface->router_event.handle_dgram = handle_icmpv6;
180 odhcpd_register(&iface->router_event);
182 uloop_timeout_cancel(&iface->timer_rs);
183 iface->timer_rs.cb = NULL;
185 memset(&mreq, 0, sizeof(mreq));
186 mreq.ipv6mr_interface = iface->ifindex;
187 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
188 setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
189 &mreq, sizeof(mreq));
191 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
192 setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
193 &mreq, sizeof(mreq));
196 memset(&mreq, 0, sizeof(mreq));
197 mreq.ipv6mr_interface = iface->ifindex;
198 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
200 if (iface->ra == MODE_RELAY && iface->master) {
201 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
202 forward_router_solicitation(iface);
203 } else if (iface->ra == MODE_SERVER) {
204 iface->timer_rs.cb = trigger_router_advert;
205 uloop_timeout_set(&iface->timer_rs, 1000);
208 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6,
209 IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
211 syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
216 if (ret < 0 && iface->router_event.uloop.fd >= 0) {
217 if (iface->router_event.uloop.registered)
218 uloop_fd_delete(&iface->router_event.uloop);
220 close(iface->router_event.uloop.fd);
221 iface->router_event.uloop.fd = -1;
228 static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info)
230 struct interface *iface;
233 case NETEV_IFINDEX_CHANGE:
235 if (iface && iface->router_event.uloop.fd >= 0) {
236 if (iface->router_event.uloop.registered)
237 uloop_fd_delete(&iface->router_event.uloop);
239 close(iface->router_event.uloop.fd);
240 iface->router_event.uloop.fd = -1;
243 case NETEV_ROUTE6_ADD:
244 case NETEV_ROUTE6_DEL:
245 if (info->rt.dst_len)
248 avl_for_each_element(&interfaces, iface, avl) {
249 if (iface->ra == MODE_SERVER && !iface->master)
250 uloop_timeout_set(&iface->timer_rs, 1000);
253 case NETEV_ADDR6LIST_CHANGE:
255 if (iface && iface->ra == MODE_SERVER && !iface->master)
256 uloop_timeout_set(&iface->timer_rs, 1000);
264 static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size_t len)
266 struct icmp6_hdr *hdr = (struct icmp6_hdr *)data;
267 struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
269 /* Hoplimit is already checked in odhcpd_receive_packets */
270 if (len < sizeof(*hdr) || hdr->icmp6_code)
273 switch (hdr->icmp6_type) {
274 case ND_ROUTER_ADVERT:
275 if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
278 opt = (struct icmpv6_opt *)((struct nd_router_advert *)data + 1);
281 case ND_ROUTER_SOLICIT:
282 opt = (struct icmpv6_opt *)((struct nd_router_solicit *)data + 1);
289 icmpv6_for_each_option(opt, opt, end)
290 if (opt->type == ND_OPT_SOURCE_LINKADDR &&
291 IN6_IS_ADDR_UNSPECIFIED(&source->sin6_addr) &&
292 hdr->icmp6_type == ND_ROUTER_SOLICIT)
295 /* Check all options parsed successfully */
300 /* Detect whether a default route exists, also find the source prefixes */
301 static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
303 struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0,
304 .dprefix = 0, .preferred = 0, .valid = 0};
305 bool found_default = false;
306 char line[512], ifname[16];
310 while (fgets(line, sizeof(line), fp_route)) {
312 if (sscanf(line, "00000000000000000000000000000000 00 "
313 "%*s %*s %*s %*s %*s %*s %*s %15s", ifname) &&
314 strcmp(ifname, "lo")) {
315 found_default = true;
316 } else if (sscanf(line, "%8" SCNx32 "%8" SCNx32 "%*8" SCNx32 "%*8" SCNx32 " %hhx %*s "
317 "%*s 00000000000000000000000000000000 %*s %*s %*s %" SCNx32 " lo",
318 &p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix, &rflags) &&
319 p.prefix > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
320 // Find source prefixes by scanning through unreachable-routes
321 p.addr.in6.s6_addr32[0] = htonl(p.addr.in6.s6_addr32[0]);
322 p.addr.in6.s6_addr32[1] = htonl(p.addr.in6.s6_addr32[1]);
324 for (ssize_t i = 0; i < len; ++i) {
325 if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
326 !odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix)) {
327 n[i].dprefix = p.prefix;
334 return found_default;
337 static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
340 uint32_t minival = iface->ra_mininterval;
343 *maxival = iface->ra_maxinterval;
345 if (*maxival > minvalid/3)
346 *maxival = minvalid/3;
348 if (*maxival > MaxRtrAdvInterval)
349 *maxival = MaxRtrAdvInterval;
350 else if (*maxival < 4)
353 if (minival < MinRtrAdvInterval)
354 minival = MinRtrAdvInterval;
355 else if (minival > (*maxival * 3)/4)
356 minival = (*maxival >= 9 ? *maxival/3 : *maxival);
358 odhcpd_urandom(&msecs, sizeof(msecs));
359 msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
362 /* RFC 2461 6.2.4 For the first MAX_INITIAL_RTR_ADVERTISEMENTS advertisements */
363 /* if the timer is bigger than MAX_INITIAL_RTR_ADVERT_INTERVAL it should be */
364 /* set to MAX_INITIAL_RTR_ADVERT_INTERVAL */
365 /* Off by one as an initial interval timer has already expired */
366 if ((iface->ra_sent + 1) < MaxInitialRtAdvs && msecs > MaxInitialRtrAdvInterval*1000)
367 msecs = MaxInitialRtrAdvInterval*1000;
372 static uint32_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
374 uint32_t lifetime = 3*maxival;
376 if (iface->ra_lifetime >= 0) {
377 lifetime = iface->ra_lifetime;
378 if (lifetime > 0 && lifetime < maxival)
380 else if (lifetime > 9000)
398 struct nd_router_advert h;
399 struct icmpv6_opt lladdr;
400 struct nd_opt_mtu mtu;
403 struct nd_opt_dns_server {
409 struct in6_addr addr[];
412 struct nd_opt_search_list {
421 struct nd_opt_route_info {
430 /* Router Advert server mode */
431 static int send_router_advert(struct interface *iface, const struct in6_addr *from)
433 time_t now = odhcpd_time();
434 struct odhcpd_ipaddr *addrs = NULL;
436 struct nd_opt_prefix_info *pfxs = NULL;
437 struct nd_opt_dns_server *dns = NULL;
438 struct nd_opt_search_list *search = NULL;
439 struct nd_opt_route_info *routes = NULL;
440 struct nd_opt_adv_interval adv_interval;
441 struct iovec iov[IOV_RA_TOTAL];
442 struct sockaddr_in6 dest;
443 size_t dns_sz = 0, search_sz = 0, pfxs_cnt = 0, routes_cnt = 0;
444 ssize_t addr_cnt = 0;
445 uint32_t minvalid = UINT32_MAX, maxival, lifetime;
446 int msecs, mtu = iface->ra_mtu, hlim = iface->ra_hoplimit;
447 bool default_route = false;
448 bool valid_prefix = false;
449 char buf[INET6_ADDRSTRLEN];
451 memset(&adv, 0, sizeof(adv));
452 adv.h.nd_ra_type = ND_ROUTER_ADVERT;
455 hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
458 adv.h.nd_ra_curhoplimit = hlim;
460 adv.h.nd_ra_flags_reserved = iface->ra_flags;
462 if (iface->route_preference < 0)
463 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
464 else if (iface->route_preference > 0)
465 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
467 adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime);
468 adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime);
470 adv.lladdr.type = ND_OPT_SOURCE_LINKADDR;
472 odhcpd_get_mac(iface, adv.lladdr.data);
474 adv.mtu.nd_opt_mtu_type = ND_OPT_MTU;
475 adv.mtu.nd_opt_mtu_len = 1;
478 mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
483 adv.mtu.nd_opt_mtu_mtu = htonl(mtu);
485 iov[IOV_RA_ADV].iov_base = (char *)&adv;
486 iov[IOV_RA_ADV].iov_len = sizeof(adv);
488 /* If not shutdown */
489 if (iface->timer_rs.cb) {
490 size_t size = sizeof(*addrs) * iface->addr6_len;
492 addrs = alloca(size);
493 memcpy(addrs, iface->addr6, size);
495 addr_cnt = iface->addr6_len;
497 /* Check default route */
498 if (iface->default_router) {
499 default_route = true;
501 if (iface->default_router > 1)
503 } else if (parse_routes(addrs, addr_cnt))
504 default_route = true;
507 /* Construct Prefix Information options */
508 for (ssize_t i = 0; i < addr_cnt; ++i) {
509 struct odhcpd_ipaddr *addr = &addrs[i];
510 struct nd_opt_prefix_info *p = NULL;
511 uint32_t preferred = 0;
514 if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
515 syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
516 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix,
517 addr->valid, iface->name);
521 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
522 iface->pio_filter_length) != 0 ||
523 addr->prefix < iface->pio_filter_length) {
524 syslog(LOG_INFO, "Address %s filtered out as RA prefix on %s",
525 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
527 continue; /* PIO filtered out of this RA */
530 for (size_t i = 0; i < pfxs_cnt; ++i) {
531 if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
532 !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
533 &addr->addr.in6, addr->prefix))
538 struct nd_opt_prefix_info *tmp;
540 tmp = realloc(pfxs, sizeof(*pfxs) * (pfxs_cnt + 1));
542 syslog(LOG_ERR, "Realloc failed for RA prefix option on %s", iface->name);
547 p = &pfxs[pfxs_cnt++];
548 memset(p, 0, sizeof(*p));
551 if (addr->preferred > (uint32_t)now) {
552 preferred = TIME_LEFT(addr->preferred, now);
554 if (iface->ra_useleasetime &&
555 preferred > iface->dhcp_leasetime)
556 preferred = iface->dhcp_leasetime;
559 valid = TIME_LEFT(addr->valid, now);
560 if (iface->ra_useleasetime && valid > iface->dhcp_leasetime)
561 valid = iface->dhcp_leasetime;
563 if (minvalid > valid)
566 if (!IN6_IS_ADDR_ULA(&addr->addr.in6) || iface->default_router)
569 odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
570 (iface->ra_advrouter) ? 128 : addr->prefix);
571 p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
572 p->nd_opt_pi_len = 4;
573 p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
574 p->nd_opt_pi_flags_reserved = 0;
575 if (!iface->ra_not_onlink)
576 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
577 if (iface->ra_slaac && addr->prefix <= 64)
578 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
579 if (iface->ra_advrouter)
580 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
581 p->nd_opt_pi_preferred_time = htonl(preferred);
582 p->nd_opt_pi_valid_time = htonl(valid);
585 iov[IOV_RA_PFXS].iov_base = (char *)pfxs;
586 iov[IOV_RA_PFXS].iov_len = pfxs_cnt * sizeof(*pfxs);
588 /* Calculate periodic transmit */
589 msecs = calc_adv_interval(iface, minvalid, &maxival);
590 lifetime = calc_ra_lifetime(iface, maxival);
594 syslog(LOG_WARNING, "A default route is present but there is no public prefix "
595 "on %s thus we don't announce a default route!", iface->name);
596 adv.h.nd_ra_router_lifetime = 0;
598 adv.h.nd_ra_router_lifetime = htons(lifetime < UINT16_MAX ? lifetime : UINT16_MAX);
601 adv.h.nd_ra_router_lifetime = 0;
603 syslog(LOG_DEBUG, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->name);
607 struct in6_addr dns_pref, *dns_addr = NULL;
608 size_t dns_cnt = 0, search_len = iface->search_len;
609 uint8_t *search_domain = iface->search;
610 uint8_t search_buf[256];
612 /* DNS Recursive DNS */
613 if (iface->dns_cnt > 0) {
614 dns_addr = iface->dns;
615 dns_cnt = iface->dns_cnt;
616 } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) {
617 dns_addr = &dns_pref;
622 dns_sz = sizeof(*dns) + sizeof(struct in6_addr)*dns_cnt;
624 dns = alloca(dns_sz);
625 memset(dns, 0, dns_sz);
626 dns->type = ND_OPT_RECURSIVE_DNS;
627 dns->len = 1 + (2 * dns_cnt);
628 dns->lifetime = htonl(lifetime);
629 memcpy(dns->addr, dns_addr, sizeof(struct in6_addr)*dns_cnt);
632 /* DNS Search options */
633 if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
634 int len = dn_comp(_res.dnsrch[0], search_buf,
635 sizeof(search_buf), NULL, NULL);
637 search_domain = search_buf;
642 if (search_len > 0) {
643 size_t search_padded = ((search_len + 7) & (~7)) + 8;
645 search_sz = sizeof(*search) + search_padded;
647 search = alloca(search_sz);
648 memset(search, 0, search_sz);
649 search->type = ND_OPT_DNS_SEARCH;
650 search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
651 search->lifetime = htonl(lifetime);
652 memcpy(search->name, search_domain, search_len);
653 memset(&search->name[search_len], 0, search_padded - search_len);
657 iov[IOV_RA_DNS].iov_base = (char *)dns;
658 iov[IOV_RA_DNS].iov_len = dns_sz;
659 iov[IOV_RA_SEARCH].iov_base = (char *)search;
660 iov[IOV_RA_SEARCH].iov_len = search_sz;
662 for (ssize_t i = 0; i < addr_cnt; ++i) {
663 struct odhcpd_ipaddr *addr = &addrs[i];
664 struct nd_opt_route_info *tmp;
667 if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now) {
668 syslog(LOG_INFO, "Address %s (dprefix %d, valid %u) not suitable as RA route on %s",
669 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
670 addr->dprefix, addr->valid, iface->name);
672 continue; /* Address not suitable */
675 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
676 iface->pio_filter_length) != 0 ||
677 addr->prefix < iface->pio_filter_length) {
678 syslog(LOG_INFO, "Address %s filtered out as RA route on %s",
679 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
681 continue; /* PIO filtered out of this RA */
684 if (addr->dprefix > 32) {
685 addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
686 } else if (addr->dprefix <= 32) {
687 addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
688 addr->addr.in6.s6_addr32[1] = 0;
691 tmp = realloc(routes, sizeof(*routes) * (routes_cnt + 1));
693 syslog(LOG_ERR, "Realloc failed for RA route option on %s", iface->name);
699 memset(&routes[routes_cnt], 0, sizeof(*routes));
700 routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
701 routes[routes_cnt].len = sizeof(*routes) / 8;
702 routes[routes_cnt].prefix = addr->dprefix;
703 routes[routes_cnt].flags = 0;
704 if (iface->route_preference < 0)
705 routes[routes_cnt].flags |= ND_RA_PREF_LOW;
706 else if (iface->route_preference > 0)
707 routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
709 valid = TIME_LEFT(addr->valid, now);
710 routes[routes_cnt].lifetime = htonl(valid < lifetime ? valid : lifetime);
711 routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0];
712 routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1];
713 routes[routes_cnt].addr[2] = 0;
714 routes[routes_cnt].addr[3] = 0;
719 iov[IOV_RA_ROUTES].iov_base = (char *)routes;
720 iov[IOV_RA_ROUTES].iov_len = routes_cnt * sizeof(*routes);
722 memset(&adv_interval, 0, sizeof(adv_interval));
723 adv_interval.nd_opt_adv_interval_type = ND_OPT_RTR_ADV_INTERVAL;
724 adv_interval.nd_opt_adv_interval_len = 1;
725 adv_interval.nd_opt_adv_interval_ival = htonl(maxival);
727 iov[IOV_RA_ADV_INTERVAL].iov_base = (char *)&adv_interval;
728 iov[IOV_RA_ADV_INTERVAL].iov_len = adv_interval.nd_opt_adv_interval_len * 8;
730 memset(&dest, 0, sizeof(dest));
731 dest.sin6_family = AF_INET6;
733 if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
734 dest.sin6_addr = *from;
736 inet_pton(AF_INET6, ALL_IPV6_NODES, &dest.sin6_addr);
738 syslog(LOG_NOTICE, "Sending a RA on %s", iface->name);
740 if (odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface) > 0)
750 static void trigger_router_advert(struct uloop_timeout *event)
752 struct interface *iface = container_of(event, struct interface, timer_rs);
753 int msecs = send_router_advert(iface, NULL);
755 /* Rearm timer if not shut down */
757 uloop_timeout_set(event, msecs);
761 /* Event handler for incoming ICMPv6 packets */
762 static void handle_icmpv6(void *addr, void *data, size_t len,
763 struct interface *iface, _unused void *dest)
765 struct icmp6_hdr *hdr = data;
766 struct sockaddr_in6 *from = addr;
768 if (!router_icmpv6_valid(addr, data, len))
771 if ((iface->ra == MODE_SERVER && !iface->master)) { /* Server mode */
772 if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
773 send_router_advert(iface, &from->sin6_addr);
774 } else if (iface->ra == MODE_RELAY) { /* Relay mode */
775 if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master) {
778 avl_for_each_element(&interfaces, c, avl) {
779 if (!c->master || c->ra != MODE_RELAY)
782 forward_router_solicitation(c);
784 } else if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
785 forward_router_advertisement(iface, data, len);
790 /* Forward router solicitation */
791 static void forward_router_solicitation(const struct interface *iface)
793 struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}};
794 struct iovec iov = {&rs, sizeof(rs)};
795 struct sockaddr_in6 all_routers;
800 memset(&all_routers, 0, sizeof(all_routers));
801 all_routers.sin6_family = AF_INET6;
802 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &all_routers.sin6_addr);
803 all_routers.sin6_scope_id = iface->ifindex;
805 syslog(LOG_NOTICE, "Sending RS to %s", iface->name);
806 odhcpd_send(iface->router_event.uloop.fd, &all_routers, &iov, 1, iface);
810 /* Handler for incoming router solicitations on slave interfaces */
811 static void forward_router_advertisement(const struct interface *iface, uint8_t *data, size_t len)
813 struct nd_router_advert *adv = (struct nd_router_advert *)data;
814 struct sockaddr_in6 all_nodes;
815 struct icmpv6_opt *opt;
817 struct iovec iov = { .iov_base = data, .iov_len = len };
818 /* Rewrite options */
819 uint8_t *end = data + len;
820 uint8_t *mac_ptr = NULL;
821 struct in6_addr *dns_ptr = NULL;
822 size_t dns_count = 0;
824 icmpv6_for_each_option(opt, &adv[1], end) {
825 if (opt->type == ND_OPT_SOURCE_LINKADDR) {
826 /* Store address of source MAC-address */
828 } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 1) {
829 /* Check if we have to rewrite DNS */
830 dns_ptr = (struct in6_addr*)&opt->data[6];
831 dns_count = (opt->len - 1) / 2;
835 syslog(LOG_NOTICE, "Got a RA on %s", iface->name);
837 /* Indicate a proxy, however we don't follow the rest of RFC 4389 yet */
838 adv->nd_ra_flags_reserved |= ND_RA_FLAG_PROXY;
840 /* Forward advertisement to all slave interfaces */
841 memset(&all_nodes, 0, sizeof(all_nodes));
842 all_nodes.sin6_family = AF_INET6;
843 inet_pton(AF_INET6, ALL_IPV6_NODES, &all_nodes.sin6_addr);
845 avl_for_each_element(&interfaces, c, avl) {
846 if (c->ra != MODE_RELAY || c->master)
849 /* Fixup source hardware address option */
851 odhcpd_get_mac(c, mac_ptr);
853 /* If we have to rewrite DNS entries */
854 if (c->always_rewrite_dns && dns_ptr && dns_count > 0) {
855 const struct in6_addr *rewrite = c->dns;
856 struct in6_addr addr;
857 size_t rewrite_cnt = c->dns_cnt;
859 if (rewrite_cnt == 0) {
860 if (odhcpd_get_interface_dns_addr(c, &addr))
861 continue; /* Unable to comply */
867 /* Copy over any other addresses */
868 for (size_t i = 0; i < dns_count; ++i) {
869 size_t j = (i < rewrite_cnt) ? i : rewrite_cnt - 1;
870 dns_ptr[i] = rewrite[j];
874 syslog(LOG_NOTICE, "Forward a RA on %s", c->name);
876 odhcpd_send(c->router_event.uloop.fd, &all_nodes, &iov, 1, c);