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(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 list_for_each_entry(iface, &interfaces, head) {
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;
299 return found_default;
302 static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
305 uint32_t minival = iface->ra_mininterval;
308 *maxival = iface->ra_maxinterval;
310 if (*maxival > minvalid/3)
311 *maxival = minvalid/3;
313 if (*maxival > MaxRtrAdvInterval)
314 *maxival = MaxRtrAdvInterval;
315 else if (*maxival < 4)
318 if (minival < MinRtrAdvInterval)
319 minival = MinRtrAdvInterval;
320 else if (minival > (*maxival * 3)/4)
321 minival = (*maxival >= 9 ? *maxival/3 : *maxival);
323 odhcpd_urandom(&msecs, sizeof(msecs));
324 msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
330 static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
332 uint16_t lifetime = 3*maxival;
334 if (iface->ra_lifetime >= 0) {
335 lifetime = iface->ra_lifetime;
336 if (lifetime < maxival)
338 else if (lifetime > 9000)
356 /* Router Advert server mode */
357 static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
359 time_t now = odhcpd_time();
360 int mtu = iface->ra_mtu;
361 int hlim = iface->ra_hoplimit;
362 char buf[INET6_ADDRSTRLEN];
365 mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
371 hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
374 struct nd_router_advert h;
375 struct icmpv6_opt lladdr;
376 struct nd_opt_mtu mtu;
378 .h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0},
379 .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
380 .mtu = {ND_OPT_MTU, 1, 0, htonl(mtu)},
384 adv.h.nd_ra_curhoplimit = hlim;
387 adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
389 if (iface->ra_managed >= RA_MANAGED_MFLAG)
390 adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
393 if (iface->route_preference < 0)
394 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
395 else if (iface->route_preference > 0)
396 adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
398 adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime);
399 adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime);
401 odhcpd_get_mac(iface, adv.lladdr.data);
403 /* If not currently shutting down */
404 struct odhcpd_ipaddr *addrs = NULL;
406 uint32_t minvalid = UINT32_MAX;
407 bool default_route = false;
408 bool valid_prefix = false;
410 /* If not shutdown */
411 if (iface->timer_rs.cb) {
412 size_t size = sizeof(*addrs) * iface->addr6_len;
413 addrs = alloca(size);
414 memcpy(addrs, iface->addr6, size);
416 ipcnt = iface->addr6_len;
418 /* Check default route */
419 if (iface->default_router) {
420 default_route = true;
422 if (iface->default_router > 1)
424 } else if (parse_routes(addrs, ipcnt))
425 default_route = true;
428 /* DNS Recursive DNS */
429 struct in6_addr dns_pref, *dns_addr = NULL;
433 if (iface->dns_cnt > 0) {
434 dns_addr = iface->dns;
435 dns_cnt = iface->dns_cnt;
436 } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) {
437 dns_addr = &dns_pref;
442 /* Construct Prefix Information options */
444 struct nd_opt_prefix_info *pfxs = NULL;
446 for (ssize_t i = 0; i < ipcnt; ++i) {
447 struct odhcpd_ipaddr *addr = &addrs[i];
448 uint32_t preferred = 0;
451 if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
452 syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
453 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix,
454 addr->valid, iface->ifname);
458 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
459 iface->pio_filter_length) != 0 ||
460 addr->prefix < iface->pio_filter_length)
461 continue; // PIO filtered out of this RA
463 struct nd_opt_prefix_info *p = NULL;
464 for (size_t i = 0; i < pfxs_cnt; ++i) {
465 if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
466 !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
467 &addr->addr.in6, addr->prefix))
472 struct nd_opt_prefix_info *tmp;
474 tmp = realloc(pfxs, sizeof(*pfxs) * (pfxs_cnt + 1));
476 syslog(LOG_ERR, "Realloc failed for RA prefix option on interface %s", iface->ifname);
481 p = &pfxs[pfxs_cnt++];
482 memset(p, 0, sizeof(*p));
485 if (addr->preferred > (uint32_t)now) {
486 preferred = TIME_LEFT(addr->preferred, now);
488 if (iface->ra_useleasetime &&
489 preferred > iface->dhcpv4_leasetime)
490 preferred = iface->dhcpv4_leasetime;
493 valid = TIME_LEFT(addr->valid, now);
494 if (iface->ra_useleasetime && valid > iface->dhcpv4_leasetime)
495 valid = iface->dhcpv4_leasetime;
497 if (minvalid > valid)
500 if (!IN6_IS_ADDR_ULA(&addr->addr.in6) || iface->default_router)
503 odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
504 (iface->ra_advrouter) ? 128 : addr->prefix);
505 p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
506 p->nd_opt_pi_len = 4;
507 p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
508 p->nd_opt_pi_flags_reserved = 0;
509 if (!iface->ra_not_onlink)
510 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
511 if (iface->ra_managed < RA_MANAGED_NO_AFLAG && addr->prefix <= 64)
512 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
513 if (iface->ra_advrouter)
514 p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
515 p->nd_opt_pi_preferred_time = htonl(preferred);
516 p->nd_opt_pi_valid_time = htonl(valid);
519 /* Calculate periodic transmit */
521 int msecs = calc_adv_interval(iface, minvalid, &maxival);
525 syslog(LOG_WARNING, "A default route is present but there is no public prefix "
526 "on %s thus we don't announce a default route!", iface->ifname);
527 adv.h.nd_ra_router_lifetime = 0;
529 adv.h.nd_ra_router_lifetime = htons(calc_ra_lifetime(iface, maxival));
532 adv.h.nd_ra_router_lifetime = 0;
534 syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->ifname);
542 } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0};
544 /* DNS Search options */
545 uint8_t *search_domain = NULL;
546 size_t search_len = 0, search_padded = 0;
549 search_len = iface->search_len;
550 search_domain = iface->search;
552 if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
553 uint8_t search_buf[256];
555 int len = dn_comp(_res.dnsrch[0], search_buf,
556 sizeof(search_buf), NULL, NULL);
558 search_domain = search_buf;
565 search_padded = ((search_len + 7) & (~7)) + 8;
574 } *search = alloca(sizeof(*search) + search_padded);
576 search->type = ND_OPT_DNS_SEARCH;
577 search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
581 if (search_len > 0) {
582 memcpy(search->name, search_domain, search_len);
583 memset(&search->name[search_len], 0, search_padded - search_len);
586 size_t routes_cnt = 0;
594 } *tmp, *routes = NULL;
596 for (ssize_t i = 0; i < ipcnt; ++i) {
597 struct odhcpd_ipaddr *addr = &addrs[i];
598 if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now) {
599 syslog(LOG_INFO, "Address %s (dprefix %d, valid %u) not suitable as RA route on %s",
600 inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
601 addr->dprefix, addr->valid, iface->ifname);
603 continue; /* Address not suitable */
606 if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
607 iface->pio_filter_length) != 0 ||
608 addr->prefix < iface->pio_filter_length)
609 continue; /* RIO filtered out of this RA */
611 if (addr->dprefix > 32) {
612 addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
613 } else if (addr->dprefix <= 32) {
614 addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
615 addr->addr.in6.s6_addr32[1] = 0;
618 tmp = realloc(routes, sizeof(*routes) * (routes_cnt + 1));
620 syslog(LOG_ERR, "Realloc failed for RA route option on interface %s", iface->ifname);
626 memset(&routes[routes_cnt], 0, sizeof(*routes));
627 routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
628 routes[routes_cnt].len = sizeof(*routes) / 8;
629 routes[routes_cnt].prefix = addr->dprefix;
630 routes[routes_cnt].flags = 0;
631 if (iface->route_preference < 0)
632 routes[routes_cnt].flags |= ND_RA_PREF_LOW;
633 else if (iface->route_preference > 0)
634 routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
635 routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now));
636 routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0];
637 routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1];
638 routes[routes_cnt].addr[2] = 0;
639 routes[routes_cnt].addr[3] = 0;
644 search->lifetime = htonl(maxival*10);
645 dns.lifetime = search->lifetime;
647 struct icmpv6_opt adv_interval = {
648 .type = ND_OPT_RTR_ADV_INTERVAL,
650 .data = {0, 0, (maxival*1000) >> 24, (maxival*1000) >> 16, (maxival*1000) >> 8, maxival*1000}
653 struct iovec iov[IOV_RA_TOTAL] = {
654 [IOV_RA_ADV] = {&adv, sizeof(adv)},
655 [IOV_RA_PFXS] = {pfxs, pfxs_cnt * sizeof(*pfxs)},
656 [IOV_RA_ROUTES] = {routes, routes_cnt * sizeof(*routes)},
657 [IOV_RA_DNS] = {&dns, (dns_cnt) ? sizeof(dns) : 0},
658 [IOV_RA_DNS_ADDR] = {dns_addr, dns_cnt * sizeof(*dns_addr)},
659 [IOV_RA_SEARCH] = {search, search->len * 8},
660 [IOV_RA_ADV_INTERVAL] = {&adv_interval, adv_interval.len * 8}};
661 struct sockaddr_in6 dest;
663 memset(&dest, 0, sizeof(dest));
664 dest.sin6_family = AF_INET6;
666 if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
667 dest.sin6_addr = *from;
669 inet_pton(AF_INET6, ALL_IPV6_NODES, &dest.sin6_addr);
671 odhcpd_send(router_event.uloop.fd,
672 &dest, iov, ARRAY_SIZE(iov), iface);
681 static void trigger_router_advert(struct uloop_timeout *event)
683 struct interface *iface = container_of(event, struct interface, timer_rs);
684 int msecs = send_router_advert(iface, NULL);
686 /* Rearm timer if not shut down */
688 uloop_timeout_set(event, msecs);
692 /* Event handler for incoming ICMPv6 packets */
693 static void handle_icmpv6(void *addr, void *data, size_t len,
694 struct interface *iface, _unused void *dest)
696 struct icmp6_hdr *hdr = data;
697 struct sockaddr_in6 *from = addr;
699 if (!router_icmpv6_valid(addr, data, len))
702 if ((iface->ra == MODE_SERVER && !iface->master)) { /* Server mode */
703 if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
704 send_router_advert(iface, &from->sin6_addr);
705 } else if (iface->ra == MODE_RELAY) { /* Relay mode */
706 if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
707 forward_router_advertisement(data, len);
708 else if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master)
709 forward_router_solicitation(odhcpd_get_master_interface());
714 /* Forward router solicitation */
715 static void forward_router_solicitation(const struct interface *iface)
717 struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}};
718 struct iovec iov = {&rs, sizeof(rs)};
719 struct sockaddr_in6 all_routers;
724 memset(&all_routers, 0, sizeof(all_routers));
725 all_routers.sin6_family = AF_INET6;
726 inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &all_routers.sin6_addr);
727 all_routers.sin6_scope_id = iface->ifindex;
729 syslog(LOG_NOTICE, "Sending RS to %s", iface->ifname);
730 odhcpd_send(router_event.uloop.fd, &all_routers, &iov, 1, iface);
734 /* Handler for incoming router solicitations on slave interfaces */
735 static void forward_router_advertisement(uint8_t *data, size_t len)
737 struct nd_router_advert *adv = (struct nd_router_advert *)data;
738 struct sockaddr_in6 all_nodes;
740 /* Rewrite options */
741 uint8_t *end = data + len;
742 uint8_t *mac_ptr = NULL;
743 struct in6_addr *dns_ptr = NULL;
744 size_t dns_count = 0;
746 struct icmpv6_opt *opt;
747 icmpv6_for_each_option(opt, &adv[1], end) {
748 if (opt->type == ND_OPT_SOURCE_LINKADDR) {
749 /* Store address of source MAC-address */
751 } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 1) {
752 /* Check if we have to rewrite DNS */
753 dns_ptr = (struct in6_addr*)&opt->data[6];
754 dns_count = (opt->len - 1) / 2;
758 syslog(LOG_NOTICE, "Got a RA");
760 /* Indicate a proxy, however we don't follow the rest of RFC 4389 yet */
761 adv->nd_ra_flags_reserved |= ND_RA_FLAG_PROXY;
763 /* Forward advertisement to all slave interfaces */
764 memset(&all_nodes, 0, sizeof(all_nodes));
765 all_nodes.sin6_family = AF_INET6;
766 inet_pton(AF_INET6, ALL_IPV6_NODES, &all_nodes.sin6_addr);
768 struct iovec iov = {data, len};
770 struct interface *iface;
771 list_for_each_entry(iface, &interfaces, head) {
772 if (iface->ra != MODE_RELAY || iface->master)
775 /* Fixup source hardware address option */
777 odhcpd_get_mac(iface, mac_ptr);
779 /* If we have to rewrite DNS entries */
780 if (iface->always_rewrite_dns && dns_ptr && dns_count > 0) {
781 const struct in6_addr *rewrite = iface->dns;
782 struct in6_addr addr;
783 size_t rewrite_cnt = iface->dns_cnt;
785 if (rewrite_cnt == 0) {
786 if (odhcpd_get_interface_dns_addr(iface, &addr))
787 continue; /* Unable to comply */
793 /* Copy over any other addresses */
794 for (size_t i = 0; i < dns_count; ++i) {
795 size_t j = (i < rewrite_cnt) ? i : rewrite_cnt - 1;
796 dns_ptr[i] = rewrite[j];
800 odhcpd_send(router_event.uloop.fd, &all_nodes, &iov, 1, iface);