src/network/networkd-ndisc.c - systemd-stable - Rivoreo Source Code Repositories

 /***
   This file is part of systemd.

   Copyright (C) 2014 Intel Corporation. All rights reserved.

   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.

   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/

 #include <netinet/icmp6.h>
 #include <arpa/inet.h>

 #include "sd-ndisc.h"

 #include "networkd-ndisc.h"
 #include "networkd-route.h"

 #define NDISC_DNSSL_MAX 64U
 #define NDISC_RDNSS_MAX 64U

 static int ndisc_netlink_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
         _cleanup_link_unref_ Link *link = userdata;
         int r;

         assert(link);
         assert(link->ndisc_messages > 0);

         link->ndisc_messages--;

         r = sd_netlink_message_get_errno(m);
         if (r < 0 && r != -EEXIST) {
                 log_link_error_errno(link, r, "Could not set NDisc route or address: %m");
                 link_enter_failed(link);
         }

         if (link->ndisc_messages == 0) {
                 link->ndisc_configured = true;
                 link_check_ready(link);
         }

         return 1;
 }

 static void ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
         _cleanup_route_free_ Route *route = NULL;
         struct in6_addr gateway;
         uint16_t lifetime;
         unsigned preference;
         uint32_t mtu;
         usec_t time_now;
         int r;
         Address *address;
         Iterator i;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_get_lifetime(rt, &lifetime);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
                 return;
         }
         if (lifetime == 0) /* not a default router */
                 return;

         r = sd_ndisc_router_get_address(rt, &gateway);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
                 return;
         }

         SET_FOREACH(address, link->addresses, i) {
                 if (!memcmp(&gateway, &address->in_addr.in6,
                             sizeof(address->in_addr.in6))) {
                         char buffer[INET6_ADDRSTRLEN];

                         log_link_debug(link, "No NDisc route added, gateway %s matches local address",
                                        inet_ntop(AF_INET6,
                                                  &address->in_addr.in6,
                                                  buffer, sizeof(buffer)));
                         return;
                 }
         }

         SET_FOREACH(address, link->addresses_foreign, i) {
                 if (!memcmp(&gateway, &address->in_addr.in6,
                             sizeof(address->in_addr.in6))) {
                         char buffer[INET6_ADDRSTRLEN];

                         log_link_debug(link, "No NDisc route added, gateway %s matches local address",
                                        inet_ntop(AF_INET6,
                                                  &address->in_addr.in6,
                                                  buffer, sizeof(buffer)));
                         return;
                 }
         }

         r = sd_ndisc_router_get_preference(rt, &preference);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
                 return;
         }

         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
                 return;
         }

         r = sd_ndisc_router_get_mtu(rt, &mtu);
         if (r == -ENODATA)
                 mtu = 0;
         else if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get default router MTU from RA: %m");
                 return;
         }

         r = route_new(&route);
         if (r < 0) {
                 log_link_error_errno(link, r, "Could not allocate route: %m");
                 return;
         }

         route->family = AF_INET6;
         route->table = link->network->ipv6_accept_ra_route_table;
         route->priority = link->network->dhcp_route_metric;
         route->protocol = RTPROT_RA;
         route->pref = preference;
         route->gw.in6 = gateway;
         route->lifetime = time_now + lifetime * USEC_PER_SEC;
         route->mtu = mtu;

         r = route_configure(route, link, ndisc_netlink_handler);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Could not set default route: %m");
                 link_enter_failed(link);
                 return;
         }

         link->ndisc_messages++;
 }

 static void ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
         _cleanup_address_free_ Address *address = NULL;
         uint32_t lifetime_valid, lifetime_preferred;
         unsigned prefixlen;
         int r;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix length: %m");
                 return;
         }

         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
                 return;
         }

         r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
                 return;
         }

         r = address_new(&address);
         if (r < 0) {
                 log_link_error_errno(link, r, "Could not allocate address: %m");
                 return;
         }

         address->family = AF_INET6;
         r = sd_ndisc_router_prefix_get_address(rt, &address->in_addr.in6);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix address: %m");
                 return;
         }

         if (in_addr_is_null(AF_INET6, (const union in_addr_union *) &link->network->ipv6_token) == 0)
                 memcpy(((char *)&address->in_addr.in6) + 8, ((char *)&link->network->ipv6_token) + 8, 8);
         else {
                 /* see RFC4291 section 2.5.1 */
                 address->in_addr.in6.s6_addr[8]  = link->mac.ether_addr_octet[0];
                 address->in_addr.in6.s6_addr[8] ^= 1 << 1;
                 address->in_addr.in6.s6_addr[9]  = link->mac.ether_addr_octet[1];
                 address->in_addr.in6.s6_addr[10] = link->mac.ether_addr_octet[2];
                 address->in_addr.in6.s6_addr[11] = 0xff;
                 address->in_addr.in6.s6_addr[12] = 0xfe;
                 address->in_addr.in6.s6_addr[13] = link->mac.ether_addr_octet[3];
                 address->in_addr.in6.s6_addr[14] = link->mac.ether_addr_octet[4];
                 address->in_addr.in6.s6_addr[15] = link->mac.ether_addr_octet[5];
         }
         address->prefixlen = prefixlen;
         address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
         address->cinfo.ifa_prefered = lifetime_preferred;
         address->cinfo.ifa_valid = lifetime_valid;

         r = address_configure(address, link, ndisc_netlink_handler, true);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Could not set SLAAC address: %m");
                 link_enter_failed(link);
                 return;
         }

         link->ndisc_messages++;
 }

 static void ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
         _cleanup_route_free_ Route *route = NULL;
         usec_t time_now;
         uint32_t lifetime;
         unsigned prefixlen;
         int r;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
                 return;
         }

         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix length: %m");
                 return;
         }

         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
                 return;
         }

         r = route_new(&route);
         if (r < 0) {
                 log_link_error_errno(link, r, "Could not allocate route: %m");
                 return;
         }

         route->family = AF_INET6;
         route->table = link->network->ipv6_accept_ra_route_table;
         route->priority = link->network->dhcp_route_metric;
         route->protocol = RTPROT_RA;
         route->flags = RTM_F_PREFIX;
         route->dst_prefixlen = prefixlen;
         route->lifetime = time_now + lifetime * USEC_PER_SEC;

         r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get prefix address: %m");
                 return;
         }

         r = route_configure(route, link, ndisc_netlink_handler);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Could not set prefix route: %m");
                 link_enter_failed(link);
                 return;
         }

         link->ndisc_messages++;
 }

 static void ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
         _cleanup_route_free_ Route *route = NULL;
         struct in6_addr gateway;
         uint32_t lifetime;
         unsigned preference, prefixlen;
         usec_t time_now;
         int r;

         assert(link);

         r = sd_ndisc_router_route_get_lifetime(rt, &lifetime);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
                 return;
         }
         if (lifetime == 0)
                 return;

         r = sd_ndisc_router_get_address(rt, &gateway);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
                 return;
         }

         r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get route prefix length: %m");
                 return;
         }

         r = sd_ndisc_router_route_get_preference(rt, &preference);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
                 return;
         }

         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
                 return;
         }

         r = route_new(&route);
         if (r < 0) {
                 log_link_error_errno(link, r, "Could not allocate route: %m");
                 return;
         }

         route->family = AF_INET6;
         route->table = link->network->ipv6_accept_ra_route_table;
         route->protocol = RTPROT_RA;
         route->pref = preference;
         route->gw.in6 = gateway;
         route->dst_prefixlen = prefixlen;
         route->lifetime = time_now + lifetime * USEC_PER_SEC;

         r = sd_ndisc_router_route_get_address(rt, &route->dst.in6);
         if (r < 0) {
                 log_link_error_errno(link, r, "Failed to get route address: %m");
                 return;
         }

         r = route_configure(route, link, ndisc_netlink_handler);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Could not set additional route: %m");
                 link_enter_failed(link);
                 return;
         }

         link->ndisc_messages++;
 }

 static void ndisc_rdnss_hash_func(const void *p, struct siphash *state) {
         const NDiscRDNSS *x = p;

         siphash24_compress(&x->address, sizeof(x->address), state);
 }

 static int ndisc_rdnss_compare_func(const void *_a, const void *_b) {
         const NDiscRDNSS *a = _a, *b = _b;

         return memcmp(&a->address, &b->address, sizeof(a->address));
 }

 static const struct hash_ops ndisc_rdnss_hash_ops = {
         .hash = ndisc_rdnss_hash_func,
         .compare = ndisc_rdnss_compare_func
 };

 static void ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
         uint32_t lifetime;
         const struct in6_addr *a;
         usec_t time_now;
         int i, n, r;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
                 return;
         }

         r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
                 return;
         }

         n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
         if (n < 0) {
                 log_link_warning_errno(link, n, "Failed to get RDNSS addresses: %m");
                 return;
         }

         for (i = 0; i < n; i++) {
                 NDiscRDNSS d = {
                         .address = a[i]
                 }, *x;

                 if (lifetime == 0) {
                         (void) set_remove(link->ndisc_rdnss, &d);
                         link_dirty(link);
                         continue;
                 }

                 x = set_get(link->ndisc_rdnss, &d);
                 if (x) {
                         x->valid_until = time_now + lifetime * USEC_PER_SEC;
                         continue;
                 }

                 ndisc_vacuum(link);

                 if (set_size(link->ndisc_rdnss) >= NDISC_RDNSS_MAX) {
                         log_link_warning(link, "Too many RDNSS records per link, ignoring.");
                         continue;
                 }

                 r = set_ensure_allocated(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops);
                 if (r < 0) {
                         log_oom();
                         return;
                 }

                 x = new0(NDiscRDNSS, 1);
                 if (!x) {
                         log_oom();
                         return;
                 }

                 x->address = a[i];
                 x->valid_until = time_now + lifetime * USEC_PER_SEC;

                 r = set_put(link->ndisc_rdnss, x);
                 if (r < 0) {
                         free(x);
                         log_oom();
                         return;
                 }

                 assert(r > 0);
                 link_dirty(link);
         }
 }

 static void ndisc_dnssl_hash_func(const void *p, struct siphash *state) {
         const NDiscDNSSL *x = p;

         siphash24_compress(NDISC_DNSSL_DOMAIN(x), strlen(NDISC_DNSSL_DOMAIN(x)), state);
 }

 static int ndisc_dnssl_compare_func(const void *_a, const void *_b) {
         const NDiscDNSSL *a = _a, *b = _b;

         return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
 }

 static const struct hash_ops ndisc_dnssl_hash_ops = {
         .hash = ndisc_dnssl_hash_func,
         .compare = ndisc_dnssl_compare_func
 };

 static void ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
         _cleanup_strv_free_ char **l = NULL;
         uint32_t lifetime;
         usec_t time_now;
         char **i;
         int r;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
                 return;
         }

         r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
                 return;
         }

         r = sd_ndisc_router_dnssl_get_domains(rt, &l);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RDNSS addresses: %m");
                 return;
         }

         STRV_FOREACH(i, l) {
                 _cleanup_free_ NDiscDNSSL *s;
                 NDiscDNSSL *x;

                 s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*i) + 1);
                 if (!s) {
                         log_oom();
                         return;
                 }

                 strcpy(NDISC_DNSSL_DOMAIN(s), *i);

                 if (lifetime == 0) {
                         (void) set_remove(link->ndisc_dnssl, s);
                         link_dirty(link);
                         continue;
                 }

                 x = set_get(link->ndisc_dnssl, s);
                 if (x) {
                         x->valid_until = time_now + lifetime * USEC_PER_SEC;
                         continue;
                 }

                 ndisc_vacuum(link);

                 if (set_size(link->ndisc_dnssl) >= NDISC_DNSSL_MAX) {
                         log_link_warning(link, "Too many DNSSL records per link, ignoring.");
                         continue;
                 }

                 r = set_ensure_allocated(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops);
                 if (r < 0) {
                         log_oom();
                         return;
                 }

                 s->valid_until = time_now + lifetime * USEC_PER_SEC;

                 r = set_put(link->ndisc_dnssl, s);
                 if (r < 0) {
                         log_oom();
                         return;
                 }

                 s = NULL;
                 assert(r > 0);
                 link_dirty(link);
         }
 }

 static void ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
         int r;

         assert(link);
         assert(rt);

         r = sd_ndisc_router_option_rewind(rt);
         for (;;) {
                 uint8_t type;

                 if (r < 0) {
                         log_link_warning_errno(link, r, "Failed to iterate through options: %m");
                         return;
                 }
                 if (r == 0) /* EOF */
                         break;

                 r = sd_ndisc_router_option_get_type(rt, &type);
                 if (r < 0) {
                         log_link_warning_errno(link, r, "Failed to get RA option type: %m");
                         return;
                 }

                 switch (type) {

                 case SD_NDISC_OPTION_PREFIX_INFORMATION: {
                         uint8_t flags;

                         r = sd_ndisc_router_prefix_get_flags(rt, &flags);
                         if (r < 0) {
                                 log_link_warning_errno(link, r, "Failed to get RA prefix flags: %m");
                                 return;
                         }

                         if (flags & ND_OPT_PI_FLAG_ONLINK)
                                 ndisc_router_process_onlink_prefix(link, rt);
                         if (flags & ND_OPT_PI_FLAG_AUTO)
                                 ndisc_router_process_autonomous_prefix(link, rt);

                         break;
                 }

                 case SD_NDISC_OPTION_ROUTE_INFORMATION:
                         ndisc_router_process_route(link, rt);
                         break;

                 case SD_NDISC_OPTION_RDNSS:
                         if (link->network->ipv6_accept_ra_use_dns)
                                 ndisc_router_process_rdnss(link, rt);
                         break;

                 case SD_NDISC_OPTION_DNSSL:
                         if (link->network->ipv6_accept_ra_use_dns)
                                 ndisc_router_process_dnssl(link, rt);
                         break;
                 }

                 r = sd_ndisc_router_option_next(rt);
         }
 }

 static void ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
         uint64_t flags;
         int r;

         assert(link);
         assert(link->network);
         assert(link->manager);
         assert(rt);

         r = sd_ndisc_router_get_flags(rt, &flags);
         if (r < 0) {
                 log_link_warning_errno(link, r, "Failed to get RA flags: %m");
                 return;
         }

         if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) {
                 /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */
                 r = dhcp6_request_address(link, !(flags & ND_RA_FLAG_MANAGED));
                 if (r < 0 && r != -EBUSY)
                         log_link_warning_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
                 else
                         log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
         }

         ndisc_router_process_default(link, rt);
         ndisc_router_process_options(link, rt);
 }

 static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event event, sd_ndisc_router *rt, void *userdata) {
         Link *link = userdata;

         assert(link);

         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
                 return;

         switch (event) {

         case SD_NDISC_EVENT_ROUTER:
                 ndisc_router_handler(link, rt);
                 break;

         case SD_NDISC_EVENT_TIMEOUT:
                 link->ndisc_configured = true;
                 link_check_ready(link);

                 break;
         default:
                 log_link_warning(link, "IPv6 Neighbor Discovery unknown event: %d", event);
         }
 }

 int ndisc_configure(Link *link) {
         int r;

         assert(link);

         r = sd_ndisc_new(&link->ndisc);
         if (r < 0)
                 return r;

         r = sd_ndisc_attach_event(link->ndisc, NULL, 0);
         if (r < 0)
                 return r;

         r = sd_ndisc_set_mac(link->ndisc, &link->mac);
         if (r < 0)
                 return r;

         r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
         if (r < 0)
                 return r;

         r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
         if (r < 0)
                 return r;

         return 0;
 }

 void ndisc_vacuum(Link *link) {
         NDiscRDNSS *r;
         NDiscDNSSL *d;
         Iterator i;
         usec_t time_now;

         assert(link);

         /* Removes all RDNSS and DNSSL entries whose validity time has passed */

         time_now = now(clock_boottime_or_monotonic());

         SET_FOREACH(r, link->ndisc_rdnss, i)
                 if (r->valid_until < time_now) {
                         free(set_remove(link->ndisc_rdnss, r));
                         link_dirty(link);
                 }

         SET_FOREACH(d, link->ndisc_dnssl, i)
                 if (d->valid_until < time_now) {
                         free(set_remove(link->ndisc_dnssl, d));
                         link_dirty(link);
                 }
 }

 void ndisc_flush(Link *link) {
         assert(link);

         /* Removes all RDNSS and DNSSL entries, without exception */

         link->ndisc_rdnss = set_free_free(link->ndisc_rdnss);
         link->ndisc_dnssl = set_free_free(link->ndisc_dnssl);
 }
	/***
	This file is part of systemd.

	Copyright (C) 2014 Intel Corporation. All rights reserved.

	systemd is free software; you can redistribute it and/or modify it
	under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2.1 of the License, or
	(at your option) any later version.

	systemd is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	***/

	#include <netinet/icmp6.h>
	#include <arpa/inet.h>

	#include "sd-ndisc.h"

	#include "networkd-ndisc.h"
	#include "networkd-route.h"

	#define NDISC_DNSSL_MAX 64U
	#define NDISC_RDNSS_MAX 64U

	static int ndisc_netlink_handler(sd_netlink rtnl, sd_netlink_message m, void *userdata) {
	_cleanup_link_unref_ Link *link = userdata;
	int r;

	assert(link);
	assert(link->ndisc_messages > 0);

	link->ndisc_messages--;

	r = sd_netlink_message_get_errno(m);
	if (r < 0 && r != -EEXIST) {
	log_link_error_errno(link, r, "Could not set NDisc route or address: %m");
	link_enter_failed(link);
	}

	if (link->ndisc_messages == 0) {
	link->ndisc_configured = true;
	link_check_ready(link);
	}

	return 1;
	}

	static void ndisc_router_process_default(Link link, sd_ndisc_router rt) {
	_cleanup_route_free_ Route *route = NULL;
	struct in6_addr gateway;
	uint16_t lifetime;
	unsigned preference;
	uint32_t mtu;
	usec_t time_now;
	int r;
	Address *address;
	Iterator i;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_get_lifetime(rt, &lifetime);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
	return;
	}
	if (lifetime == 0) /* not a default router */
	return;

	r = sd_ndisc_router_get_address(rt, &gateway);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
	return;
	}

	SET_FOREACH(address, link->addresses, i) {
	if (!memcmp(&gateway, &address->in_addr.in6,
	sizeof(address->in_addr.in6))) {
	char buffer[INET6_ADDRSTRLEN];

	log_link_debug(link, "No NDisc route added, gateway %s matches local address",
	inet_ntop(AF_INET6,
	&address->in_addr.in6,
	buffer, sizeof(buffer)));
	return;
	}
	}

	SET_FOREACH(address, link->addresses_foreign, i) {
	if (!memcmp(&gateway, &address->in_addr.in6,
	sizeof(address->in_addr.in6))) {
	char buffer[INET6_ADDRSTRLEN];

	log_link_debug(link, "No NDisc route added, gateway %s matches local address",
	inet_ntop(AF_INET6,
	&address->in_addr.in6,
	buffer, sizeof(buffer)));
	return;
	}
	}

	r = sd_ndisc_router_get_preference(rt, &preference);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
	return;
	}

	r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
	return;
	}

	r = sd_ndisc_router_get_mtu(rt, &mtu);
	if (r == -ENODATA)
	mtu = 0;
	else if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get default router MTU from RA: %m");
	return;
	}

	r = route_new(&route);
	if (r < 0) {
	log_link_error_errno(link, r, "Could not allocate route: %m");
	return;
	}

	route->family = AF_INET6;
	route->table = link->network->ipv6_accept_ra_route_table;
	route->priority = link->network->dhcp_route_metric;
	route->protocol = RTPROT_RA;
	route->pref = preference;
	route->gw.in6 = gateway;
	route->lifetime = time_now + lifetime * USEC_PER_SEC;
	route->mtu = mtu;

	r = route_configure(route, link, ndisc_netlink_handler);
	if (r < 0) {
	log_link_warning_errno(link, r, "Could not set default route: %m");
	link_enter_failed(link);
	return;
	}

	link->ndisc_messages++;
	}

	static void ndisc_router_process_autonomous_prefix(Link link, sd_ndisc_router rt) {
	_cleanup_address_free_ Address *address = NULL;
	uint32_t lifetime_valid, lifetime_preferred;
	unsigned prefixlen;
	int r;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix length: %m");
	return;
	}

	r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
	return;
	}

	r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
	return;
	}

	r = address_new(&address);
	if (r < 0) {
	log_link_error_errno(link, r, "Could not allocate address: %m");
	return;
	}

	address->family = AF_INET6;
	r = sd_ndisc_router_prefix_get_address(rt, &address->in_addr.in6);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix address: %m");
	return;
	}

	if (in_addr_is_null(AF_INET6, (const union in_addr_union *) &link->network->ipv6_token) == 0)
	memcpy(((char )&address->in_addr.in6) + 8, ((char )&link->network->ipv6_token) + 8, 8);
	else {
	/* see RFC4291 section 2.5.1 */
	address->in_addr.in6.s6_addr[8] = link->mac.ether_addr_octet[0];
	address->in_addr.in6.s6_addr[8] ^= 1 << 1;
	address->in_addr.in6.s6_addr[9] = link->mac.ether_addr_octet[1];
	address->in_addr.in6.s6_addr[10] = link->mac.ether_addr_octet[2];
	address->in_addr.in6.s6_addr[11] = 0xff;
	address->in_addr.in6.s6_addr[12] = 0xfe;
	address->in_addr.in6.s6_addr[13] = link->mac.ether_addr_octet[3];
	address->in_addr.in6.s6_addr[14] = link->mac.ether_addr_octet[4];
	address->in_addr.in6.s6_addr[15] = link->mac.ether_addr_octet[5];
	}
	address->prefixlen = prefixlen;
	address->flags = IFA_F_NOPREFIXROUTE\|IFA_F_MANAGETEMPADDR;
	address->cinfo.ifa_prefered = lifetime_preferred;
	address->cinfo.ifa_valid = lifetime_valid;

	r = address_configure(address, link, ndisc_netlink_handler, true);
	if (r < 0) {
	log_link_warning_errno(link, r, "Could not set SLAAC address: %m");
	link_enter_failed(link);
	return;
	}

	link->ndisc_messages++;
	}

	static void ndisc_router_process_onlink_prefix(Link link, sd_ndisc_router rt) {
	_cleanup_route_free_ Route *route = NULL;
	usec_t time_now;
	uint32_t lifetime;
	unsigned prefixlen;
	int r;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
	return;
	}

	r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix length: %m");
	return;
	}

	r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
	return;
	}

	r = route_new(&route);
	if (r < 0) {
	log_link_error_errno(link, r, "Could not allocate route: %m");
	return;
	}

	route->family = AF_INET6;
	route->table = link->network->ipv6_accept_ra_route_table;
	route->priority = link->network->dhcp_route_metric;
	route->protocol = RTPROT_RA;
	route->flags = RTM_F_PREFIX;
	route->dst_prefixlen = prefixlen;
	route->lifetime = time_now + lifetime * USEC_PER_SEC;

	r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get prefix address: %m");
	return;
	}

	r = route_configure(route, link, ndisc_netlink_handler);
	if (r < 0) {
	log_link_warning_errno(link, r, "Could not set prefix route: %m");
	link_enter_failed(link);
	return;
	}

	link->ndisc_messages++;
	}

	static void ndisc_router_process_route(Link link, sd_ndisc_router rt) {
	_cleanup_route_free_ Route *route = NULL;
	struct in6_addr gateway;
	uint32_t lifetime;
	unsigned preference, prefixlen;
	usec_t time_now;
	int r;

	assert(link);

	r = sd_ndisc_router_route_get_lifetime(rt, &lifetime);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
	return;
	}
	if (lifetime == 0)
	return;

	r = sd_ndisc_router_get_address(rt, &gateway);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
	return;
	}

	r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get route prefix length: %m");
	return;
	}

	r = sd_ndisc_router_route_get_preference(rt, &preference);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
	return;
	}

	r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
	return;
	}

	r = route_new(&route);
	if (r < 0) {
	log_link_error_errno(link, r, "Could not allocate route: %m");
	return;
	}

	route->family = AF_INET6;
	route->table = link->network->ipv6_accept_ra_route_table;
	route->protocol = RTPROT_RA;
	route->pref = preference;
	route->gw.in6 = gateway;
	route->dst_prefixlen = prefixlen;
	route->lifetime = time_now + lifetime * USEC_PER_SEC;

	r = sd_ndisc_router_route_get_address(rt, &route->dst.in6);
	if (r < 0) {
	log_link_error_errno(link, r, "Failed to get route address: %m");
	return;
	}

	r = route_configure(route, link, ndisc_netlink_handler);
	if (r < 0) {
	log_link_warning_errno(link, r, "Could not set additional route: %m");
	link_enter_failed(link);
	return;
	}

	link->ndisc_messages++;
	}

	static void ndisc_rdnss_hash_func(const void p, struct siphash state) {
	const NDiscRDNSS *x = p;

	siphash24_compress(&x->address, sizeof(x->address), state);
	}

	static int ndisc_rdnss_compare_func(const void _a, const void _b) {
	const NDiscRDNSS a = _a, b = _b;

	return memcmp(&a->address, &b->address, sizeof(a->address));
	}

	static const struct hash_ops ndisc_rdnss_hash_ops = {
	.hash = ndisc_rdnss_hash_func,
	.compare = ndisc_rdnss_compare_func
	};

	static void ndisc_router_process_rdnss(Link link, sd_ndisc_router rt) {
	uint32_t lifetime;
	const struct in6_addr *a;
	usec_t time_now;
	int i, n, r;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
	return;
	}

	r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
	return;
	}

	n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
	if (n < 0) {
	log_link_warning_errno(link, n, "Failed to get RDNSS addresses: %m");
	return;
	}

	for (i = 0; i < n; i++) {
	NDiscRDNSS d = {
	.address = a[i]
	}, *x;

	if (lifetime == 0) {
	(void) set_remove(link->ndisc_rdnss, &d);
	link_dirty(link);
	continue;
	}

	x = set_get(link->ndisc_rdnss, &d);
	if (x) {
	x->valid_until = time_now + lifetime * USEC_PER_SEC;
	continue;
	}

	ndisc_vacuum(link);

	if (set_size(link->ndisc_rdnss) >= NDISC_RDNSS_MAX) {
	log_link_warning(link, "Too many RDNSS records per link, ignoring.");
	continue;
	}

	r = set_ensure_allocated(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops);
	if (r < 0) {
	log_oom();
	return;
	}

	x = new0(NDiscRDNSS, 1);
	if (!x) {
	log_oom();
	return;
	}

	x->address = a[i];
	x->valid_until = time_now + lifetime * USEC_PER_SEC;

	r = set_put(link->ndisc_rdnss, x);
	if (r < 0) {
	free(x);
	log_oom();
	return;
	}

	assert(r > 0);
	link_dirty(link);
	}
	}

	static void ndisc_dnssl_hash_func(const void p, struct siphash state) {
	const NDiscDNSSL *x = p;

	siphash24_compress(NDISC_DNSSL_DOMAIN(x), strlen(NDISC_DNSSL_DOMAIN(x)), state);
	}

	static int ndisc_dnssl_compare_func(const void _a, const void _b) {
	const NDiscDNSSL a = _a, b = _b;

	return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
	}

	static const struct hash_ops ndisc_dnssl_hash_ops = {
	.hash = ndisc_dnssl_hash_func,
	.compare = ndisc_dnssl_compare_func
	};

	static void ndisc_router_process_dnssl(Link link, sd_ndisc_router rt) {
	_cleanup_strv_free_ char **l = NULL;
	uint32_t lifetime;
	usec_t time_now;
	char **i;
	int r;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
	return;
	}

	r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
	return;
	}

	r = sd_ndisc_router_dnssl_get_domains(rt, &l);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RDNSS addresses: %m");
	return;
	}

	STRV_FOREACH(i, l) {
	_cleanup_free_ NDiscDNSSL *s;
	NDiscDNSSL *x;

	s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*i) + 1);
	if (!s) {
	log_oom();
	return;
	}

	strcpy(NDISC_DNSSL_DOMAIN(s), *i);

	if (lifetime == 0) {
	(void) set_remove(link->ndisc_dnssl, s);
	link_dirty(link);
	continue;
	}

	x = set_get(link->ndisc_dnssl, s);
	if (x) {
	x->valid_until = time_now + lifetime * USEC_PER_SEC;
	continue;
	}

	ndisc_vacuum(link);

	if (set_size(link->ndisc_dnssl) >= NDISC_DNSSL_MAX) {
	log_link_warning(link, "Too many DNSSL records per link, ignoring.");
	continue;
	}

	r = set_ensure_allocated(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops);
	if (r < 0) {
	log_oom();
	return;
	}

	s->valid_until = time_now + lifetime * USEC_PER_SEC;

	r = set_put(link->ndisc_dnssl, s);
	if (r < 0) {
	log_oom();
	return;
	}

	s = NULL;
	assert(r > 0);
	link_dirty(link);
	}
	}

	static void ndisc_router_process_options(Link link, sd_ndisc_router rt) {
	int r;

	assert(link);
	assert(rt);

	r = sd_ndisc_router_option_rewind(rt);
	for (;;) {
	uint8_t type;

	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to iterate through options: %m");
	return;
	}
	if (r == 0) /* EOF */
	break;

	r = sd_ndisc_router_option_get_type(rt, &type);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA option type: %m");
	return;
	}

	switch (type) {

	case SD_NDISC_OPTION_PREFIX_INFORMATION: {
	uint8_t flags;

	r = sd_ndisc_router_prefix_get_flags(rt, &flags);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA prefix flags: %m");
	return;
	}

	if (flags & ND_OPT_PI_FLAG_ONLINK)
	ndisc_router_process_onlink_prefix(link, rt);
	if (flags & ND_OPT_PI_FLAG_AUTO)
	ndisc_router_process_autonomous_prefix(link, rt);

	break;
	}

	case SD_NDISC_OPTION_ROUTE_INFORMATION:
	ndisc_router_process_route(link, rt);
	break;

	case SD_NDISC_OPTION_RDNSS:
	if (link->network->ipv6_accept_ra_use_dns)
	ndisc_router_process_rdnss(link, rt);
	break;

	case SD_NDISC_OPTION_DNSSL:
	if (link->network->ipv6_accept_ra_use_dns)
	ndisc_router_process_dnssl(link, rt);
	break;
	}

	r = sd_ndisc_router_option_next(rt);
	}
	}

	static void ndisc_router_handler(Link link, sd_ndisc_router rt) {
	uint64_t flags;
	int r;

	assert(link);
	assert(link->network);
	assert(link->manager);
	assert(rt);

	r = sd_ndisc_router_get_flags(rt, &flags);
	if (r < 0) {
	log_link_warning_errno(link, r, "Failed to get RA flags: %m");
	return;
	}

	if (flags & (ND_RA_FLAG_MANAGED \| ND_RA_FLAG_OTHER)) {
	/* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */
	r = dhcp6_request_address(link, !(flags & ND_RA_FLAG_MANAGED));
	if (r < 0 && r != -EBUSY)
	log_link_warning_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
	else
	log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
	}

	ndisc_router_process_default(link, rt);
	ndisc_router_process_options(link, rt);
	}

	static void ndisc_handler(sd_ndisc nd, sd_ndisc_event event, sd_ndisc_router rt, void *userdata) {
	Link *link = userdata;

	assert(link);

	if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
	return;

	switch (event) {

	case SD_NDISC_EVENT_ROUTER:
	ndisc_router_handler(link, rt);
	break;

	case SD_NDISC_EVENT_TIMEOUT:
	link->ndisc_configured = true;
	link_check_ready(link);

	break;
	default:
	log_link_warning(link, "IPv6 Neighbor Discovery unknown event: %d", event);
	}
	}

	int ndisc_configure(Link *link) {
	int r;

	assert(link);

	r = sd_ndisc_new(&link->ndisc);
	if (r < 0)
	return r;

	r = sd_ndisc_attach_event(link->ndisc, NULL, 0);
	if (r < 0)
	return r;

	r = sd_ndisc_set_mac(link->ndisc, &link->mac);
	if (r < 0)
	return r;

	r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
	if (r < 0)
	return r;

	r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
	if (r < 0)
	return r;

	return 0;
	}

	void ndisc_vacuum(Link *link) {
	NDiscRDNSS *r;
	NDiscDNSSL *d;
	Iterator i;
	usec_t time_now;

	assert(link);

	/* Removes all RDNSS and DNSSL entries whose validity time has passed */

	time_now = now(clock_boottime_or_monotonic());

	SET_FOREACH(r, link->ndisc_rdnss, i)
	if (r->valid_until < time_now) {
	free(set_remove(link->ndisc_rdnss, r));
	link_dirty(link);
	}

	SET_FOREACH(d, link->ndisc_dnssl, i)
	if (d->valid_until < time_now) {
	free(set_remove(link->ndisc_dnssl, d));
	link_dirty(link);
	}
	}

	void ndisc_flush(Link *link) {
	assert(link);

	/* Removes all RDNSS and DNSSL entries, without exception */

	link->ndisc_rdnss = set_free_free(link->ndisc_rdnss);
	link->ndisc_dnssl = set_free_free(link->ndisc_dnssl);
	}