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)
83 if ((!enable || iface->ra == MODE_DISABLED) && iface->router_event.uloop.fd >= 0) {
85 uloop_timeout_cancel(&iface->timer_rs);
86 iface->timer_rs.cb = NULL;
88 trigger_router_advert(&iface->timer_rs);
91 uloop_fd_delete(&iface->router_event.uloop);
92 close(iface->router_event.uloop.fd);
93 iface->router_event.uloop.fd = -1;
94 } else if (enable && iface->ra != MODE_DISABLED) {
95 struct icmp6_filter filt;
96 struct ipv6_mreq mreq;
99 if (iface->router_event.uloop.fd < 0) {
100 /* Open ICMPv6 socket */
101 iface->router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC,
103 if (iface->router_event.uloop.fd < 0) {
104 syslog(LOG_ERR, "socket(AF_INET6): %m");
109 if (setsockopt(iface->router_event.uloop.fd, SOL_SOCKET, SO_BINDTODEVICE,
110 iface->ifname, strlen(iface->ifname)) < 0) {
111 syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
116 /* Let the kernel compute our checksums */
117 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
118 &val, sizeof(val)) < 0) {
119 syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
124 /* This is required by RFC 4861 */
126 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
127 &val, sizeof(val)) < 0) {
128 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
133 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
134 &val, sizeof(val)) < 0) {
135 syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
140 /* We need to know the source interface */
142 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
143 &val, sizeof(val)) < 0) {
144 syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
149 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
150 &val, sizeof(val)) < 0) {
151 syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
156 /* Don't loop back */
158 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
159 &val, sizeof(val)) < 0) {
160 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
165 /* Filter ICMPv6 package types */
166 ICMP6_FILTER_SETBLOCKALL(&filt);
167 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
168 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
169 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
170 &filt, sizeof(filt)) < 0) {
171 syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
176 iface->router_event.handle_dgram = handle_icmpv6;
177 odhcpd_register(&iface->router_event);
179 uloop_timeout_cancel(&iface->timer_rs);
180 iface->timer_rs.cb = NULL;
182 memset(&mreq, 0, sizeof(mreq));
183 mreq.ipv6mr_interface = iface->ifindex;
184 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
185 setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
186 &mreq, sizeof(mreq));
188 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
189 setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
190 &mreq, sizeof(mreq));
193 memset(&mreq, 0, sizeof(mreq));
194 mreq.ipv6mr_interface = iface->ifindex;
195 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
197 if (iface->ra == MODE_RELAY && iface->master) {
198 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
199 forward_router_solicitation(iface);
200 } else if (iface->ra == MODE_SERVER) {
201 iface->timer_rs.cb = trigger_router_advert;
202 uloop_timeout_set(&iface->timer_rs, 1000);
205 if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6,
206 IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
208 syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
213 if (ret < 0 && iface->router_event.uloop.fd >= 0) {
214 close(iface->router_event.uloop.fd);
215 iface->router_event.uloop.fd = -1;
222 static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info)
224 struct interface *iface;
227 case NETEV_ROUTE6_ADD:
228 case NETEV_ROUTE6_DEL:
229 if (info->rt.dst_len)
232 avl_for_each_element(&interfaces, iface, avl) {
233 if (iface->ra == MODE_SERVER && !iface->master)
234 uloop_timeout_set(&iface->timer_rs, 1000);
237 case NETEV_ADDR6LIST_CHANGE:
239 if (iface && iface->ra == MODE_SERVER && !iface->master)
240 uloop_timeout_set(&iface->timer_rs, 1000);
248 static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size_t len)
250 struct icmp6_hdr *hdr = (struct icmp6_hdr *)data;
251 struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
253 /* Hoplimit is already checked in odhcpd_receive_packets */
254 if (len < sizeof(*hdr) || hdr->icmp6_code)
257 switch (hdr->icmp6_type) {
258 case ND_ROUTER_ADVERT:
259 if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
262 opt = (struct icmpv6_opt *)((struct nd_router_advert *)data + 1);
265 case ND_ROUTER_SOLICIT:
266 opt = (struct icmpv6_opt *)((struct nd_router_solicit *)data + 1);
273 icmpv6_for_each_option(opt, opt, end)
274 if (opt->type == ND_OPT_SOURCE_LINKADDR &&
275 IN6_IS_ADDR_UNSPECIFIED(&source->sin6_addr) &&
276 hdr->icmp6_type == ND_ROUTER_SOLICIT)
279 /* Check all options parsed successfully */
284 /* Detect whether a default route exists, also find the source prefixes */
285 static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
287 struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0,
288 .dprefix = 0, .preferred = 0, .valid = 0};
289 bool found_default = false;
290 char line[512], ifname[16];
294 while (fgets(line, sizeof(line), fp_route)) {
296 if (sscanf(line, "00000000000000000000000000000000 00 "
297 "%*s %*s %*s %*s %*s %*s %*s %15s", ifname) &&
298 strcmp(ifname, "lo")) {
299 found_default = true;
300 } else if (sscanf(line, "%8" SCNx32 "%8" SCNx32 "%*8" SCNx32 "%*8" SCNx32 " %hhx %*s "
301 "%*s 00000000000000000000000000000000 %*s %*s %*s %" SCNx32 " lo",
302 &p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix, &rflags) &&
303 p.prefix > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
304 // Find source prefixes by scanning through unreachable-routes
305 p.addr.in6.s6_addr32[0] = htonl(p.addr.in6.s6_addr32[0]);
306 p.addr.in6.s6_addr32[1] = htonl(p.addr.in6.s6_addr32[1]);
308 for (ssize_t i = 0; i < len; ++i) {
309 if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
310 !odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix)) {
311 n[i].dprefix = p.prefix;
318 return found_default;
321 static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
324 uint32_t minival = iface->ra_mininterval;
327 *maxival = iface->ra_maxinterval;
329 if (*maxival > minvalid/3)
330 *maxival = minvalid/3;
332 if (*maxival > MaxRtrAdvInterval)
333 *maxival = MaxRtrAdvInterval;
334 else if (*maxival < 4)
337 if (minival < MinRtrAdvInterval)
338 minival = MinRtrAdvInterval;
339 else if (minival > (*maxival * 3)/4)
340 minival = (*maxival >= 9 ? *maxival/3 : *maxival);
342 odhcpd_urandom(&msecs, sizeof(msecs));
343 msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
349 static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
351 uint16_t lifetime = 3*maxival;
353 if (iface->ra_lifetime >= 0) {
354 lifetime = iface->ra_lifetime;
355 if (lifetime < maxival)
357 else if (lifetime > 9000)
375 struct nd_router_advert h;
376 struct icmpv6_opt lladdr;
377 struct nd_opt_mtu mtu;
380 struct nd_opt_dns_server {
386 struct in6_addr addr[];
389 struct nd_opt_search_list {
398 struct nd_opt_route_info {
407 /* Router Advert server mode */
408 static int send_router_advert(struct interface *iface, const struct in6_addr *from)
410 time_t now = odhcpd_time();
411 struct odhcpd_ipaddr *addrs = NULL;
413 struct nd_opt_prefix_info *pfxs = NULL;
414 struct nd_opt_dns_server *dns = NULL;
415 struct nd_opt_search_list *search = NULL;
416 struct nd_opt_route_info *routes = NULL;
417 struct nd_opt_adv_interval adv_interval;
418 struct iovec iov[IOV_RA_TOTAL];
419 struct sockaddr_in6 dest;
420 size_t dns_sz = 0, search_sz = 0, pfxs_cnt = 0, routes_cnt = 0;
421 ssize_t addr_cnt = 0;
422 uint32_t minvalid = UINT32_MAX, maxival;
423 int msecs, mtu = iface->ra_mtu, hlim = iface->ra_hoplimit;
424 bool default_route = false;
425 bool valid_prefix = false;
426 char buf[INET6_ADDRSTRLEN];
428 memset(&adv, 0, sizeof(adv));
429 adv.h.nd_ra_type = ND_ROUTER_ADVERT;
432 hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
435 adv.h.nd_ra_curhoplimit = hlim;
438 adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
440 if (iface->ra_managed >= RA_MANAGED_MFLAG)
441 adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
444 if (iface->route_preference < 0)
445 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
446 else if (iface->route_preference > 0)
447 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
449 adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime);
450 adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime);
452 adv.lladdr.type = ND_OPT_SOURCE_LINKADDR;
454 odhcpd_get_mac(iface, adv.lladdr.data);
456 adv.mtu.nd_opt_mtu_type = ND_OPT_MTU;
457 adv.mtu.nd_opt_mtu_len = 1;
460 mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
465 adv.mtu.nd_opt_mtu_mtu = htonl(mtu);
467 iov[IOV_RA_ADV].iov_base = (char *)&adv;
468 iov[IOV_RA_ADV].iov_len = sizeof(adv);
470 /* If not shutdown */
471 if (iface->timer_rs.cb) {
472 size_t size = sizeof(*addrs) * iface->addr6_len;
474 addrs = alloca(size);
475 memcpy(addrs, iface->addr6, size);
477 addr_cnt = iface->addr6_len;
479 /* Check default route */
480 if (iface->default_router) {
481 default_route = true;
483 if (iface->default_router > 1)
485 } else if (parse_routes(addrs, addr_cnt))
486 default_route = true;
489 /* Construct Prefix Information options */
490 for (ssize_t i = 0; i < addr_cnt; ++i) {
491 struct odhcpd_ipaddr *addr = &addrs[i];
492 struct nd_opt_prefix_info *p = NULL;
493 uint32_t preferred = 0;
496 if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
497 syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
498 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix,
499 addr->valid, iface->name);
503 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
504 iface->pio_filter_length) != 0 ||
505 addr->prefix < iface->pio_filter_length) {
506 syslog(LOG_INFO, "Address %s filtered out as RA prefix on %s",
507 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
509 continue; /* PIO filtered out of this RA */
512 for (size_t i = 0; i < pfxs_cnt; ++i) {
513 if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
514 !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
515 &addr->addr.in6, addr->prefix))
520 struct nd_opt_prefix_info *tmp;
522 tmp = realloc(pfxs, sizeof(*pfxs) * (pfxs_cnt + 1));
524 syslog(LOG_ERR, "Realloc failed for RA prefix option on %s", iface->name);
529 p = &pfxs[pfxs_cnt++];
530 memset(p, 0, sizeof(*p));
533 if (addr->preferred > (uint32_t)now) {
534 preferred = TIME_LEFT(addr->preferred, now);
536 if (iface->ra_useleasetime &&
537 preferred > iface->dhcpv4_leasetime)
538 preferred = iface->dhcpv4_leasetime;
541 valid = TIME_LEFT(addr->valid, now);
542 if (iface->ra_useleasetime && valid > iface->dhcpv4_leasetime)
543 valid = iface->dhcpv4_leasetime;
545 if (minvalid > valid)
548 if (!IN6_IS_ADDR_ULA(&addr->addr.in6) || iface->default_router)
551 odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
552 (iface->ra_advrouter) ? 128 : addr->prefix);
553 p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
554 p->nd_opt_pi_len = 4;
555 p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
556 p->nd_opt_pi_flags_reserved = 0;
557 if (!iface->ra_not_onlink)
558 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
559 if (iface->ra_managed < RA_MANAGED_NO_AFLAG && addr->prefix <= 64)
560 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
561 if (iface->ra_advrouter)
562 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
563 p->nd_opt_pi_preferred_time = htonl(preferred);
564 p->nd_opt_pi_valid_time = htonl(valid);
567 iov[IOV_RA_PFXS].iov_base = (char *)pfxs;
568 iov[IOV_RA_PFXS].iov_len = pfxs_cnt * sizeof(*pfxs);
570 /* Calculate periodic transmit */
571 msecs = calc_adv_interval(iface, minvalid, &maxival);
575 syslog(LOG_WARNING, "A default route is present but there is no public prefix "
576 "on %s thus we don't announce a default route!", iface->name);
577 adv.h.nd_ra_router_lifetime = 0;
579 adv.h.nd_ra_router_lifetime = htons(calc_ra_lifetime(iface, maxival));
582 adv.h.nd_ra_router_lifetime = 0;
584 syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->name);
588 struct in6_addr dns_pref, *dns_addr = NULL;
589 size_t dns_cnt = 0, search_padded = 0, search_len = iface->search_len;
590 uint8_t *search_domain = iface->search;
592 /* DNS Recursive DNS */
593 if (iface->dns_cnt > 0) {
594 dns_addr = iface->dns;
595 dns_cnt = iface->dns_cnt;
596 } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) {
597 dns_addr = &dns_pref;
602 dns_sz = sizeof(*dns) + sizeof(struct in6_addr)*dns_cnt;
604 dns = alloca(dns_sz);
605 memset(dns, 0, dns_sz);
606 dns->type = ND_OPT_RECURSIVE_DNS;
607 dns->len = 1 + (2 * dns_cnt);
608 dns->lifetime = htonl(maxival*10);
609 memcpy(dns->addr, dns_addr, sizeof(struct in6_addr)*dns_cnt);
612 /* DNS Search options */
613 if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
614 uint8_t search_buf[256];
616 int len = dn_comp(_res.dnsrch[0], search_buf,
617 sizeof(search_buf), NULL, NULL);
619 search_domain = search_buf;
625 search_padded = ((search_len + 7) & (~7)) + 8;
627 search_sz = sizeof(*search) + search_padded;
629 search = alloca(search_sz);
630 memset(search, 0, search_sz);
631 search->type = ND_OPT_DNS_SEARCH;
632 search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
633 search->lifetime = htonl(maxival*10);
635 if (search_len > 0) {
636 memcpy(search->name, search_domain, search_len);
637 memset(&search->name[search_len], 0, search_padded - search_len);
641 iov[IOV_RA_DNS].iov_base = (char *)dns;
642 iov[IOV_RA_DNS].iov_len = dns_sz;
643 iov[IOV_RA_SEARCH].iov_base = (char *)search;
644 iov[IOV_RA_SEARCH].iov_len = search_sz;
646 for (ssize_t i = 0; i < addr_cnt; ++i) {
647 struct odhcpd_ipaddr *addr = &addrs[i];
648 struct nd_opt_route_info *tmp;
650 if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now) {
651 syslog(LOG_INFO, "Address %s (dprefix %d, valid %u) not suitable as RA route on %s",
652 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
653 addr->dprefix, addr->valid, iface->name);
655 continue; /* Address not suitable */
658 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
659 iface->pio_filter_length) != 0 ||
660 addr->prefix < iface->pio_filter_length) {
661 syslog(LOG_INFO, "Address %s filtered out as RA route on %s",
662 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
664 continue; /* PIO filtered out of this RA */
667 if (addr->dprefix > 32) {
668 addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
669 } else if (addr->dprefix <= 32) {
670 addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
671 addr->addr.in6.s6_addr32[1] = 0;
674 tmp = realloc(routes, sizeof(*routes) * (routes_cnt + 1));
676 syslog(LOG_ERR, "Realloc failed for RA route option on %s", iface->name);
682 memset(&routes[routes_cnt], 0, sizeof(*routes));
683 routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
684 routes[routes_cnt].len = sizeof(*routes) / 8;
685 routes[routes_cnt].prefix = addr->dprefix;
686 routes[routes_cnt].flags = 0;
687 if (iface->route_preference < 0)
688 routes[routes_cnt].flags |= ND_RA_PREF_LOW;
689 else if (iface->route_preference > 0)
690 routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
692 routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now));
693 routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0];
694 routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1];
695 routes[routes_cnt].addr[2] = 0;
696 routes[routes_cnt].addr[3] = 0;
701 iov[IOV_RA_ROUTES].iov_base = (char *)routes;
702 iov[IOV_RA_ROUTES].iov_len = routes_cnt * sizeof(*routes);
704 memset(&adv_interval, 0, sizeof(adv_interval));
705 adv_interval.nd_opt_adv_interval_type = ND_OPT_RTR_ADV_INTERVAL;
706 adv_interval.nd_opt_adv_interval_len = 1;
707 adv_interval.nd_opt_adv_interval_ival = htonl(maxival);
709 iov[IOV_RA_ADV_INTERVAL].iov_base = (char *)&adv_interval;
710 iov[IOV_RA_ADV_INTERVAL].iov_len = adv_interval.nd_opt_adv_interval_len * 8;
712 memset(&dest, 0, sizeof(dest));
713 dest.sin6_family = AF_INET6;
715 if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
716 dest.sin6_addr = *from;
718 inet_pton(AF_INET6, ALL_IPV6_NODES, &dest.sin6_addr);
720 syslog(LOG_NOTICE, "Sending a RA on %s", iface->name);
722 odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface);
731 static void trigger_router_advert(struct uloop_timeout *event)
733 struct interface *iface = container_of(event, struct interface, timer_rs);
734 int msecs = send_router_advert(iface, NULL);
736 /* Rearm timer if not shut down */
738 uloop_timeout_set(event, msecs);
742 /* Event handler for incoming ICMPv6 packets */
743 static void handle_icmpv6(void *addr, void *data, size_t len,
744 struct interface *iface, _unused void *dest)
746 struct icmp6_hdr *hdr = data;
747 struct sockaddr_in6 *from = addr;
749 if (!router_icmpv6_valid(addr, data, len))
752 if ((iface->ra == MODE_SERVER && !iface->master)) { /* Server mode */
753 if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
754 send_router_advert(iface, &from->sin6_addr);
755 } else if (iface->ra == MODE_RELAY) { /* Relay mode */
756 if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master) {
759 avl_for_each_element(&interfaces, c, avl) {
760 if (!c->master || c->ra != MODE_RELAY)
763 forward_router_solicitation(c);
765 } else if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
766 forward_router_advertisement(iface, data, len);
771 /* Forward router solicitation */
772 static void forward_router_solicitation(const struct interface *iface)
774 struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}};
775 struct iovec iov = {&rs, sizeof(rs)};
776 struct sockaddr_in6 all_routers;
781 memset(&all_routers, 0, sizeof(all_routers));
782 all_routers.sin6_family = AF_INET6;
783 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &all_routers.sin6_addr);
784 all_routers.sin6_scope_id = iface->ifindex;
786 syslog(LOG_NOTICE, "Sending RS to %s", iface->name);
787 odhcpd_send(iface->router_event.uloop.fd, &all_routers, &iov, 1, iface);
791 /* Handler for incoming router solicitations on slave interfaces */
792 static void forward_router_advertisement(const struct interface *iface, uint8_t *data, size_t len)
794 struct nd_router_advert *adv = (struct nd_router_advert *)data;
795 struct sockaddr_in6 all_nodes;
796 struct icmpv6_opt *opt;
798 struct iovec iov = { .iov_base = data, .iov_len = len };
799 /* Rewrite options */
800 uint8_t *end = data + len;
801 uint8_t *mac_ptr = NULL;
802 struct in6_addr *dns_ptr = NULL;
803 size_t dns_count = 0;
805 icmpv6_for_each_option(opt, &adv[1], end) {
806 if (opt->type == ND_OPT_SOURCE_LINKADDR) {
807 /* Store address of source MAC-address */
809 } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 1) {
810 /* Check if we have to rewrite DNS */
811 dns_ptr = (struct in6_addr*)&opt->data[6];
812 dns_count = (opt->len - 1) / 2;
816 syslog(LOG_NOTICE, "Got a RA on %s", iface->name);
818 /* Indicate a proxy, however we don't follow the rest of RFC 4389 yet */
819 adv->nd_ra_flags_reserved |= ND_RA_FLAG_PROXY;
821 /* Forward advertisement to all slave interfaces */
822 memset(&all_nodes, 0, sizeof(all_nodes));
823 all_nodes.sin6_family = AF_INET6;
824 inet_pton(AF_INET6, ALL_IPV6_NODES, &all_nodes.sin6_addr);
826 avl_for_each_element(&interfaces, c, avl) {
827 if (c->ra != MODE_RELAY || c->master)
830 /* Fixup source hardware address option */
832 odhcpd_get_mac(c, mac_ptr);
834 /* If we have to rewrite DNS entries */
835 if (c->always_rewrite_dns && dns_ptr && dns_count > 0) {
836 const struct in6_addr *rewrite = c->dns;
837 struct in6_addr addr;
838 size_t rewrite_cnt = c->dns_cnt;
840 if (rewrite_cnt == 0) {
841 if (odhcpd_get_interface_dns_addr(c, &addr))
842 continue; /* Unable to comply */
848 /* Copy over any other addresses */
849 for (size_t i = 0; i < dns_count; ++i) {
850 size_t j = (i < rewrite_cnt) ? i : rewrite_cnt - 1;
851 dns_ptr[i] = rewrite[j];
855 syslog(LOG_NOTICE, "Forward a RA on %s", c->name);
857 odhcpd_send(c->router_event.uloop.fd, &all_nodes, &iov, 1, c);