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 odhcpd_event router_event = {.uloop = {.fd = -1}, .handle_dgram = handle_icmpv6, };
42 static struct netevent_handler router_netevent_handler = { .cb = router_netevent_cb, };
44 static FILE *fp_route = NULL;
47 #define TIME_LEFT(t1, now) ((t1) != UINT32_MAX ? (t1) - (now) : UINT32_MAX)
51 struct icmp6_filter filt;
54 /* Open ICMPv6 socket */
55 router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
56 if (router_event.uloop.fd < 0) {
57 syslog(LOG_ERR, "socket(AF_INET6): %m");
62 /* Let the kernel compute our checksums */
64 if (setsockopt(router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
65 &val, sizeof(val)) < 0) {
66 syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
71 /* This is required by RFC 4861 */
73 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
74 &val, sizeof(val)) < 0) {
75 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
80 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
81 &val, sizeof(val)) < 0) {
82 syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
87 /* We need to know the source interface */
89 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
90 &val, sizeof(val)) < 0) {
91 syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
96 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
97 &val, sizeof(val)) < 0) {
98 syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
103 /* Don't loop back */
105 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
106 &val, sizeof(val)) < 0) {
107 syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
112 /* Filter ICMPv6 package types */
113 ICMP6_FILTER_SETBLOCKALL(&filt);
114 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
115 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
116 if (setsockopt(router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
117 &filt, sizeof(filt)) < 0) {
118 syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
123 if (!(fp_route = fopen("/proc/net/ipv6_route", "r"))) {
124 syslog(LOG_ERR, "fopen(/proc/net/ipv6_route): %m");
129 if (netlink_add_netevent_handler(&router_netevent_handler) < 0) {
130 syslog(LOG_ERR, "Failed to add netevent handler");
135 /* Register socket */
136 odhcpd_register(&router_event);
139 if (router_event.uloop.fd > 0) {
140 close(router_event.uloop.fd);
141 router_event.uloop.fd = -1;
154 int router_setup_interface(struct interface *iface, bool enable)
156 struct ipv6_mreq mreq;
159 if (!fp_route || router_event.uloop.fd < 0) {
164 uloop_timeout_cancel(&iface->timer_rs);
165 iface->timer_rs.cb = NULL;
167 memset(&mreq, 0, sizeof(mreq));
168 mreq.ipv6mr_interface = iface->ifindex;
169 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
170 setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
171 &mreq, sizeof(mreq));
173 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
174 setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
175 &mreq, sizeof(mreq));
178 if (iface->ra == MODE_SERVER || (iface->ra == MODE_RELAY && !iface->master))
179 trigger_router_advert(&iface->timer_rs);
181 if (iface->ra == MODE_RELAY && iface->master) {
182 inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
183 forward_router_solicitation(iface);
184 } else if (iface->ra == MODE_SERVER && !iface->master) {
185 iface->timer_rs.cb = trigger_router_advert;
186 uloop_timeout_set(&iface->timer_rs, 1000);
189 if (iface->ra == MODE_RELAY || (iface->ra == MODE_SERVER && !iface->master)) {
190 if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6,
191 IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
193 syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
202 static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info)
204 struct interface *iface;
207 case NETEV_ROUTE6_ADD:
208 case NETEV_ROUTE6_DEL:
209 if (info->rt.dst_len)
212 avl_for_each_element(&interfaces, iface, avl) {
213 if (iface->ra == MODE_SERVER && !iface->master)
214 uloop_timeout_set(&iface->timer_rs, 1000);
217 case NETEV_ADDR6LIST_CHANGE:
219 if (iface && iface->ra == MODE_SERVER && !iface->master)
220 uloop_timeout_set(&iface->timer_rs, 1000);
228 static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size_t len)
230 struct icmp6_hdr *hdr = (struct icmp6_hdr *)data;
231 struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
233 /* Hoplimit is already checked in odhcpd_receive_packets */
234 if (len < sizeof(*hdr) || hdr->icmp6_code)
237 switch (hdr->icmp6_type) {
238 case ND_ROUTER_ADVERT:
239 if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
242 opt = (struct icmpv6_opt *)((struct nd_router_advert *)data + 1);
245 case ND_ROUTER_SOLICIT:
246 opt = (struct icmpv6_opt *)((struct nd_router_solicit *)data + 1);
253 icmpv6_for_each_option(opt, opt, end)
254 if (opt->type == ND_OPT_SOURCE_LINKADDR &&
255 IN6_IS_ADDR_UNSPECIFIED(&source->sin6_addr) &&
256 hdr->icmp6_type == ND_ROUTER_SOLICIT)
259 /* Check all options parsed successfully */
264 /* Detect whether a default route exists, also find the source prefixes */
265 static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
269 char line[512], ifname[16];
270 bool found_default = false;
271 struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0,
272 .dprefix = 0, .preferred = 0, .valid = 0};
274 while (fgets(line, sizeof(line), fp_route)) {
276 if (sscanf(line, "00000000000000000000000000000000 00 "
277 "%*s %*s %*s %*s %*s %*s %*s %15s", ifname) &&
278 strcmp(ifname, "lo")) {
279 found_default = true;
280 } else if (sscanf(line, "%8" SCNx32 "%8" SCNx32 "%*8" SCNx32 "%*8" SCNx32 " %hhx %*s "
281 "%*s 00000000000000000000000000000000 %*s %*s %*s %" SCNx32 " lo",
282 &p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix, &rflags) &&
283 p.prefix > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
284 // Find source prefixes by scanning through unreachable-routes
285 p.addr.in6.s6_addr32[0] = htonl(p.addr.in6.s6_addr32[0]);
286 p.addr.in6.s6_addr32[1] = htonl(p.addr.in6.s6_addr32[1]);
288 for (ssize_t i = 0; i < len; ++i) {
289 if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
290 !odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix)) {
291 n[i].dprefix = p.prefix;
298 return found_default;
301 static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
304 uint32_t minival = iface->ra_mininterval;
307 *maxival = iface->ra_maxinterval;
309 if (*maxival > minvalid/3)
310 *maxival = minvalid/3;
312 if (*maxival > MaxRtrAdvInterval)
313 *maxival = MaxRtrAdvInterval;
314 else if (*maxival < 4)
317 if (minival < MinRtrAdvInterval)
318 minival = MinRtrAdvInterval;
319 else if (minival > (*maxival * 3)/4)
320 minival = (*maxival >= 9 ? *maxival/3 : *maxival);
322 odhcpd_urandom(&msecs, sizeof(msecs));
323 msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
329 static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
331 uint16_t lifetime = 3*maxival;
333 if (iface->ra_lifetime >= 0) {
334 lifetime = iface->ra_lifetime;
335 if (lifetime < maxival)
337 else if (lifetime > 9000)
355 /* Router Advert server mode */
356 static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
358 time_t now = odhcpd_time();
359 int mtu = iface->ra_mtu;
360 int hlim = iface->ra_hoplimit;
361 char buf[INET6_ADDRSTRLEN];
364 mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
370 hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
373 struct nd_router_advert h;
374 struct icmpv6_opt lladdr;
375 struct nd_opt_mtu mtu;
377 .h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0},
378 .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
379 .mtu = {ND_OPT_MTU, 1, 0, htonl(mtu)},
383 adv.h.nd_ra_curhoplimit = hlim;
386 adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
388 if (iface->ra_managed >= RA_MANAGED_MFLAG)
389 adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
392 if (iface->route_preference < 0)
393 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
394 else if (iface->route_preference > 0)
395 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
397 adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime);
398 adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime);
400 odhcpd_get_mac(iface, adv.lladdr.data);
402 /* If not currently shutting down */
403 struct odhcpd_ipaddr *addrs = NULL;
405 uint32_t minvalid = UINT32_MAX;
406 bool default_route = false;
407 bool valid_prefix = false;
409 /* If not shutdown */
410 if (iface->timer_rs.cb) {
411 size_t size = sizeof(*addrs) * iface->addr6_len;
412 addrs = alloca(size);
413 memcpy(addrs, iface->addr6, size);
415 ipcnt = iface->addr6_len;
417 /* Check default route */
418 if (iface->default_router) {
419 default_route = true;
421 if (iface->default_router > 1)
423 } else if (parse_routes(addrs, ipcnt))
424 default_route = true;
427 /* DNS Recursive DNS */
428 struct in6_addr dns_pref, *dns_addr = NULL;
432 if (iface->dns_cnt > 0) {
433 dns_addr = iface->dns;
434 dns_cnt = iface->dns_cnt;
435 } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) {
436 dns_addr = &dns_pref;
441 /* Construct Prefix Information options */
443 struct nd_opt_prefix_info *pfxs = NULL;
445 for (ssize_t i = 0; i < ipcnt; ++i) {
446 struct odhcpd_ipaddr *addr = &addrs[i];
447 uint32_t preferred = 0;
450 if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
451 syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
452 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix,
453 addr->valid, iface->name);
457 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
458 iface->pio_filter_length) != 0 ||
459 addr->prefix < iface->pio_filter_length) {
460 syslog(LOG_INFO, "Address %s filtered out as RA prefix on %s",
461 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
463 continue; /* PIO filtered out of this RA */
466 struct nd_opt_prefix_info *p = NULL;
467 for (size_t i = 0; i < pfxs_cnt; ++i) {
468 if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
469 !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
470 &addr->addr.in6, addr->prefix))
475 struct nd_opt_prefix_info *tmp;
477 tmp = realloc(pfxs, sizeof(*pfxs) * (pfxs_cnt + 1));
479 syslog(LOG_ERR, "Realloc failed for RA prefix option on %s", iface->name);
484 p = &pfxs[pfxs_cnt++];
485 memset(p, 0, sizeof(*p));
488 if (addr->preferred > (uint32_t)now) {
489 preferred = TIME_LEFT(addr->preferred, now);
491 if (iface->ra_useleasetime &&
492 preferred > iface->dhcpv4_leasetime)
493 preferred = iface->dhcpv4_leasetime;
496 valid = TIME_LEFT(addr->valid, now);
497 if (iface->ra_useleasetime && valid > iface->dhcpv4_leasetime)
498 valid = iface->dhcpv4_leasetime;
500 if (minvalid > valid)
503 if (!IN6_IS_ADDR_ULA(&addr->addr.in6) || iface->default_router)
506 odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
507 (iface->ra_advrouter) ? 128 : addr->prefix);
508 p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
509 p->nd_opt_pi_len = 4;
510 p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
511 p->nd_opt_pi_flags_reserved = 0;
512 if (!iface->ra_not_onlink)
513 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
514 if (iface->ra_managed < RA_MANAGED_NO_AFLAG && addr->prefix <= 64)
515 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
516 if (iface->ra_advrouter)
517 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
518 p->nd_opt_pi_preferred_time = htonl(preferred);
519 p->nd_opt_pi_valid_time = htonl(valid);
522 /* Calculate periodic transmit */
524 int msecs = calc_adv_interval(iface, minvalid, &maxival);
528 syslog(LOG_WARNING, "A default route is present but there is no public prefix "
529 "on %s thus we don't announce a default route!", iface->name);
530 adv.h.nd_ra_router_lifetime = 0;
532 adv.h.nd_ra_router_lifetime = htons(calc_ra_lifetime(iface, maxival));
535 adv.h.nd_ra_router_lifetime = 0;
537 syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->name);
545 } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0};
547 /* DNS Search options */
548 uint8_t *search_domain = NULL;
549 size_t search_len = 0, search_padded = 0;
552 search_len = iface->search_len;
553 search_domain = iface->search;
555 if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
556 uint8_t search_buf[256];
558 int len = dn_comp(_res.dnsrch[0], search_buf,
559 sizeof(search_buf), NULL, NULL);
561 search_domain = search_buf;
568 search_padded = ((search_len + 7) & (~7)) + 8;
577 } *search = alloca(sizeof(*search) + search_padded);
579 search->type = ND_OPT_DNS_SEARCH;
580 search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
584 if (search_len > 0) {
585 memcpy(search->name, search_domain, search_len);
586 memset(&search->name[search_len], 0, search_padded - search_len);
589 size_t routes_cnt = 0;
597 } *tmp, *routes = NULL;
599 for (ssize_t i = 0; i < ipcnt; ++i) {
600 struct odhcpd_ipaddr *addr = &addrs[i];
601 if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now) {
602 syslog(LOG_INFO, "Address %s (dprefix %d, valid %u) not suitable as RA route on %s",
603 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
604 addr->dprefix, addr->valid, iface->name);
606 continue; /* Address not suitable */
609 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
610 iface->pio_filter_length) != 0 ||
611 addr->prefix < iface->pio_filter_length) {
612 syslog(LOG_INFO, "Address %s filtered out as RA route on %s",
613 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
615 continue; /* PIO filtered out of this RA */
618 if (addr->dprefix > 32) {
619 addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
620 } else if (addr->dprefix <= 32) {
621 addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
622 addr->addr.in6.s6_addr32[1] = 0;
625 tmp = realloc(routes, sizeof(*routes) * (routes_cnt + 1));
627 syslog(LOG_ERR, "Realloc failed for RA route option on %s", iface->name);
633 memset(&routes[routes_cnt], 0, sizeof(*routes));
634 routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
635 routes[routes_cnt].len = sizeof(*routes) / 8;
636 routes[routes_cnt].prefix = addr->dprefix;
637 routes[routes_cnt].flags = 0;
638 if (iface->route_preference < 0)
639 routes[routes_cnt].flags |= ND_RA_PREF_LOW;
640 else if (iface->route_preference > 0)
641 routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
642 routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now));
643 routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0];
644 routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1];
645 routes[routes_cnt].addr[2] = 0;
646 routes[routes_cnt].addr[3] = 0;
651 search->lifetime = htonl(maxival*10);
652 dns.lifetime = search->lifetime;
654 struct icmpv6_opt adv_interval = {
655 .type = ND_OPT_RTR_ADV_INTERVAL,
657 .data = {0, 0, (maxival*1000) >> 24, (maxival*1000) >> 16, (maxival*1000) >> 8, maxival*1000}
660 struct iovec iov[IOV_RA_TOTAL] = {
661 [IOV_RA_ADV] = {&adv, sizeof(adv)},
662 [IOV_RA_PFXS] = {pfxs, pfxs_cnt * sizeof(*pfxs)},
663 [IOV_RA_ROUTES] = {routes, routes_cnt * sizeof(*routes)},
664 [IOV_RA_DNS] = {&dns, (dns_cnt) ? sizeof(dns) : 0},
665 [IOV_RA_DNS_ADDR] = {dns_addr, dns_cnt * sizeof(*dns_addr)},
666 [IOV_RA_SEARCH] = {search, search->len * 8},
667 [IOV_RA_ADV_INTERVAL] = {&adv_interval, adv_interval.len * 8}};
668 struct sockaddr_in6 dest;
670 memset(&dest, 0, sizeof(dest));
671 dest.sin6_family = AF_INET6;
673 if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
674 dest.sin6_addr = *from;
676 inet_pton(AF_INET6, ALL_IPV6_NODES, &dest.sin6_addr);
678 syslog(LOG_INFO, "Sending a RA on %s", iface->name);
680 odhcpd_send(router_event.uloop.fd,
681 &dest, iov, ARRAY_SIZE(iov), iface);
690 static void trigger_router_advert(struct uloop_timeout *event)
692 struct interface *iface = container_of(event, struct interface, timer_rs);
693 int msecs = send_router_advert(iface, NULL);
695 /* Rearm timer if not shut down */
697 uloop_timeout_set(event, msecs);
701 /* Event handler for incoming ICMPv6 packets */
702 static void handle_icmpv6(void *addr, void *data, size_t len,
703 struct interface *iface, _unused void *dest)
705 struct icmp6_hdr *hdr = data;
706 struct sockaddr_in6 *from = addr;
708 if (!router_icmpv6_valid(addr, data, len))
711 if ((iface->ra == MODE_SERVER && !iface->master)) { /* Server mode */
712 if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
713 send_router_advert(iface, &from->sin6_addr);
714 } else if (iface->ra == MODE_RELAY) { /* Relay mode */
715 if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
716 forward_router_advertisement(iface, data, len);
717 else if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master)
718 forward_router_solicitation(odhcpd_get_master_interface());
723 /* Forward router solicitation */
724 static void forward_router_solicitation(const struct interface *iface)
726 struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}};
727 struct iovec iov = {&rs, sizeof(rs)};
728 struct sockaddr_in6 all_routers;
733 memset(&all_routers, 0, sizeof(all_routers));
734 all_routers.sin6_family = AF_INET6;
735 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &all_routers.sin6_addr);
736 all_routers.sin6_scope_id = iface->ifindex;
738 syslog(LOG_NOTICE, "Sending RS to %s", iface->name);
739 odhcpd_send(router_event.uloop.fd, &all_routers, &iov, 1, iface);
743 /* Handler for incoming router solicitations on slave interfaces */
744 static void forward_router_advertisement(const struct interface *iface, uint8_t *data, size_t len)
746 struct nd_router_advert *adv = (struct nd_router_advert *)data;
747 struct sockaddr_in6 all_nodes;
748 struct icmpv6_opt *opt;
750 struct iovec iov = { .iov_base = data, .iov_len = len };
751 /* Rewrite options */
752 uint8_t *end = data + len;
753 uint8_t *mac_ptr = NULL;
754 struct in6_addr *dns_ptr = NULL;
755 size_t dns_count = 0;
757 icmpv6_for_each_option(opt, &adv[1], end) {
758 if (opt->type == ND_OPT_SOURCE_LINKADDR) {
759 /* Store address of source MAC-address */
761 } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 1) {
762 /* Check if we have to rewrite DNS */
763 dns_ptr = (struct in6_addr*)&opt->data[6];
764 dns_count = (opt->len - 1) / 2;
768 syslog(LOG_NOTICE, "Got a RA on %s", iface->name);
770 /* Indicate a proxy, however we don't follow the rest of RFC 4389 yet */
771 adv->nd_ra_flags_reserved |= ND_RA_FLAG_PROXY;
773 /* Forward advertisement to all slave interfaces */
774 memset(&all_nodes, 0, sizeof(all_nodes));
775 all_nodes.sin6_family = AF_INET6;
776 inet_pton(AF_INET6, ALL_IPV6_NODES, &all_nodes.sin6_addr);
778 avl_for_each_element(&interfaces, c, avl) {
779 if (c->ra != MODE_RELAY || c->master)
782 /* Fixup source hardware address option */
784 odhcpd_get_mac(c, mac_ptr);
786 /* If we have to rewrite DNS entries */
787 if (c->always_rewrite_dns && dns_ptr && dns_count > 0) {
788 const struct in6_addr *rewrite = c->dns;
789 struct in6_addr addr;
790 size_t rewrite_cnt = c->dns_cnt;
792 if (rewrite_cnt == 0) {
793 if (odhcpd_get_interface_dns_addr(c, &addr))
794 continue; /* Unable to comply */
800 /* Copy over any other addresses */
801 for (size_t i = 0; i < dns_count; ++i) {
802 size_t j = (i < rewrite_cnt) ? i : rewrite_cnt - 1;
803 dns_ptr[i] = rewrite[j];
807 syslog(LOG_NOTICE, "Forward a RA on %s", c->name);
809 odhcpd_send(router_event.uloop.fd, &all_nodes, &iov, 1, c);