src/libsystemd-network/sd-ndisc.c - systemd - Git at Google

 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 /***
   Copyright © 2014 Intel Corporation. All rights reserved.
 ***/

 #include <netinet/icmp6.h>
 #include <netinet/in.h>

 #include "sd-ndisc.h"

 #include "alloc-util.h"
 #include "event-util.h"
 #include "fd-util.h"
 #include "icmp6-util.h"
 #include "in-addr-util.h"
 #include "memory-util.h"
 #include "ndisc-internal.h"
 #include "ndisc-router.h"
 #include "network-common.h"
 #include "random-util.h"
 #include "socket-util.h"
 #include "string-table.h"
 #include "string-util.h"

 #define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)

 static const char * const ndisc_event_table[_SD_NDISC_EVENT_MAX] = {
         [SD_NDISC_EVENT_TIMEOUT] = "timeout",
         [SD_NDISC_EVENT_ROUTER] = "router",
 };

 DEFINE_STRING_TABLE_LOOKUP(ndisc_event, sd_ndisc_event_t);

 static void ndisc_callback(sd_ndisc *ndisc, sd_ndisc_event_t event, sd_ndisc_router *rt) {
         assert(ndisc);
         assert(event >= 0 && event < _SD_NDISC_EVENT_MAX);

         if (!ndisc->callback)
                 return (void) log_ndisc(ndisc, "Received '%s' event.", ndisc_event_to_string(event));

         log_ndisc(ndisc, "Invoking callback for '%s' event.", ndisc_event_to_string(event));
         ndisc->callback(ndisc, event, rt, ndisc->userdata);
 }

 int sd_ndisc_set_callback(
                 sd_ndisc *nd,
                 sd_ndisc_callback_t callback,
                 void *userdata) {

         assert_return(nd, -EINVAL);

         nd->callback = callback;
         nd->userdata = userdata;

         return 0;
 }

 int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) {
         assert_return(nd, -EINVAL);
         assert_return(ifindex > 0, -EINVAL);
         assert_return(nd->fd < 0, -EBUSY);

         nd->ifindex = ifindex;
         return 0;
 }

 int sd_ndisc_set_ifname(sd_ndisc *nd, const char *ifname) {
         assert_return(nd, -EINVAL);
         assert_return(ifname, -EINVAL);

         if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
                 return -EINVAL;

         return free_and_strdup(&nd->ifname, ifname);
 }

 int sd_ndisc_get_ifname(sd_ndisc *nd, const char **ret) {
         int r;

         assert_return(nd, -EINVAL);

         r = get_ifname(nd->ifindex, &nd->ifname);
         if (r < 0)
                 return r;

         if (ret)
                 *ret = nd->ifname;

         return 0;
 }

 int sd_ndisc_set_mac(sd_ndisc *nd, const struct ether_addr *mac_addr) {
         assert_return(nd, -EINVAL);

         if (mac_addr)
                 nd->mac_addr = *mac_addr;
         else
                 zero(nd->mac_addr);

         return 0;
 }

 int sd_ndisc_attach_event(sd_ndisc *nd, sd_event *event, int64_t priority) {
         int r;

         assert_return(nd, -EINVAL);
         assert_return(nd->fd < 0, -EBUSY);
         assert_return(!nd->event, -EBUSY);

         if (event)
                 nd->event = sd_event_ref(event);
         else {
                 r = sd_event_default(&nd->event);
                 if (r < 0)
                         return 0;
         }

         nd->event_priority = priority;

         return 0;
 }

 int sd_ndisc_detach_event(sd_ndisc *nd) {

         assert_return(nd, -EINVAL);
         assert_return(nd->fd < 0, -EBUSY);

         nd->event = sd_event_unref(nd->event);
         return 0;
 }

 sd_event *sd_ndisc_get_event(sd_ndisc *nd) {
         assert_return(nd, NULL);

         return nd->event;
 }

 static void ndisc_reset(sd_ndisc *nd) {
         assert(nd);

         (void) event_source_disable(nd->timeout_event_source);
         (void) event_source_disable(nd->timeout_no_ra);
         nd->retransmit_time = 0;
         nd->recv_event_source = sd_event_source_disable_unref(nd->recv_event_source);
         nd->fd = safe_close(nd->fd);
 }

 static sd_ndisc *ndisc_free(sd_ndisc *nd) {
         assert(nd);

         ndisc_reset(nd);

         sd_event_source_unref(nd->timeout_event_source);
         sd_event_source_unref(nd->timeout_no_ra);
         sd_ndisc_detach_event(nd);

         free(nd->ifname);
         return mfree(nd);
 }

 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc, sd_ndisc, ndisc_free);

 int sd_ndisc_new(sd_ndisc **ret) {
         _cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL;

         assert_return(ret, -EINVAL);

         nd = new(sd_ndisc, 1);
         if (!nd)
                 return -ENOMEM;

         *nd = (sd_ndisc) {
                 .n_ref = 1,
                 .fd = -EBADF,
         };

         *ret = TAKE_PTR(nd);

         return 0;
 }

 static int ndisc_handle_datagram(sd_ndisc *nd, sd_ndisc_router *rt) {
         int r;

         assert(nd);
         assert(rt);

         r = ndisc_router_parse(nd, rt);
         if (r < 0)
                 return r;

         log_ndisc(nd, "Received Router Advertisement: flags %s preference %s lifetime %" PRIu16 " sec",
                   rt->flags & ND_RA_FLAG_MANAGED ? "MANAGED" : rt->flags & ND_RA_FLAG_OTHER ? "OTHER" : "none",
                   rt->preference == SD_NDISC_PREFERENCE_HIGH ? "high" : rt->preference == SD_NDISC_PREFERENCE_LOW ? "low" : "medium",
                   rt->lifetime);

         ndisc_callback(nd, SD_NDISC_EVENT_ROUTER, rt);
         return 0;
 }

 static int ndisc_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         _cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
         sd_ndisc *nd = ASSERT_PTR(userdata);
         ssize_t buflen;
         int r;

         assert(s);
         assert(nd->event);

         buflen = next_datagram_size_fd(fd);
         if (buflen < 0) {
                 if (ERRNO_IS_TRANSIENT(buflen) || ERRNO_IS_DISCONNECT(buflen))
                         return 0;

                 log_ndisc_errno(nd, buflen, "Failed to determine datagram size to read, ignoring: %m");
                 return 0;
         }

         rt = ndisc_router_new(buflen);
         if (!rt)
                 return -ENOMEM;

         r = icmp6_receive(fd, NDISC_ROUTER_RAW(rt), rt->raw_size, &rt->address, &rt->timestamp);
         if (r < 0) {
                 if (ERRNO_IS_TRANSIENT(r) || ERRNO_IS_DISCONNECT(r))
                         return 0;

                 switch (r) {
                 case -EADDRNOTAVAIL:
                         log_ndisc(nd, "Received RA from non-link-local address %s. Ignoring.",
                                   IN6_ADDR_TO_STRING(&rt->address));
                         break;

                 case -EMULTIHOP:
                         log_ndisc(nd, "Received RA with invalid hop limit. Ignoring.");
                         break;

                 case -EPFNOSUPPORT:
                         log_ndisc(nd, "Received invalid source address from ICMPv6 socket. Ignoring.");
                         break;

                 default:
                         log_ndisc_errno(nd, r, "Unexpected error while reading from ICMPv6, ignoring: %m");
                         break;
                 }

                 return 0;
         }

         (void) event_source_disable(nd->timeout_event_source);
         (void) ndisc_handle_datagram(nd, rt);
         return 0;
 }

 static usec_t ndisc_timeout_compute_random(usec_t val) {
         /* compute a time that is random within ±10% of the given value */
         return val - val / 10 +
                 (random_u64() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
 }

 static int ndisc_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
         sd_ndisc *nd = ASSERT_PTR(userdata);
         usec_t time_now;
         int r;

         assert(s);
         assert(nd->event);

         assert_se(sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now) >= 0);

         if (!nd->retransmit_time)
                 nd->retransmit_time = ndisc_timeout_compute_random(NDISC_ROUTER_SOLICITATION_INTERVAL);
         else {
                 if (nd->retransmit_time > NDISC_MAX_ROUTER_SOLICITATION_INTERVAL / 2)
                         nd->retransmit_time = ndisc_timeout_compute_random(NDISC_MAX_ROUTER_SOLICITATION_INTERVAL);
                 else
                         nd->retransmit_time += ndisc_timeout_compute_random(nd->retransmit_time);
         }

         r = event_reset_time(nd->event, &nd->timeout_event_source,
                              CLOCK_BOOTTIME,
                              time_now + nd->retransmit_time, 10 * USEC_PER_MSEC,
                              ndisc_timeout, nd,
                              nd->event_priority, "ndisc-timeout-no-ra", true);
         if (r < 0)
                 goto fail;

         r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr);
         if (r < 0)
                 log_ndisc_errno(nd, r, "Failed to send Router Solicitation, next solicitation in %s, ignoring: %m",
                                 FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));
         else
                 log_ndisc(nd, "Sent Router Solicitation, next solicitation in %s",
                           FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));

         return 0;

 fail:
         (void) sd_ndisc_stop(nd);
         return 0;
 }

 static int ndisc_timeout_no_ra(sd_event_source *s, uint64_t usec, void *userdata) {
         sd_ndisc *nd = ASSERT_PTR(userdata);

         assert(s);

         log_ndisc(nd, "No RA received before link confirmation timeout");

         (void) event_source_disable(nd->timeout_no_ra);
         ndisc_callback(nd, SD_NDISC_EVENT_TIMEOUT, NULL);

         return 0;
 }

 int sd_ndisc_stop(sd_ndisc *nd) {
         if (!nd)
                 return 0;

         if (nd->fd < 0)
                 return 0;

         log_ndisc(nd, "Stopping IPv6 Router Solicitation client");

         ndisc_reset(nd);
         return 1;
 }

 int sd_ndisc_start(sd_ndisc *nd) {
         int r;
         usec_t time_now;

         assert_return(nd, -EINVAL);
         assert_return(nd->event, -EINVAL);
         assert_return(nd->ifindex > 0, -EINVAL);

         if (nd->fd >= 0)
                 return 0;

         assert(!nd->recv_event_source);

         r = sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now);
         if (r < 0)
                 goto fail;

         nd->fd = icmp6_bind_router_solicitation(nd->ifindex);
         if (nd->fd < 0)
                 return nd->fd;

         r = sd_event_add_io(nd->event, &nd->recv_event_source, nd->fd, EPOLLIN, ndisc_recv, nd);
         if (r < 0)
                 goto fail;

         r = sd_event_source_set_priority(nd->recv_event_source, nd->event_priority);
         if (r < 0)
                 goto fail;

         (void) sd_event_source_set_description(nd->recv_event_source, "ndisc-receive-message");

         r = event_reset_time(nd->event, &nd->timeout_event_source,
                              CLOCK_BOOTTIME,
                              time_now + USEC_PER_SEC / 2, 1 * USEC_PER_SEC, /* See RFC 8415 sec. 18.2.1 */
                              ndisc_timeout, nd,
                              nd->event_priority, "ndisc-timeout", true);
         if (r < 0)
                 goto fail;

         r = event_reset_time(nd->event, &nd->timeout_no_ra,
                              CLOCK_BOOTTIME,
                              time_now + NDISC_TIMEOUT_NO_RA_USEC, 10 * USEC_PER_MSEC,
                              ndisc_timeout_no_ra, nd,
                              nd->event_priority, "ndisc-timeout-no-ra", true);
         if (r < 0)
                 goto fail;

         log_ndisc(nd, "Started IPv6 Router Solicitation client");
         return 1;

 fail:
         ndisc_reset(nd);
         return r;
 }
	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	/***
	Copyright © 2014 Intel Corporation. All rights reserved.
	***/

	#include <netinet/icmp6.h>
	#include <netinet/in.h>

	#include "sd-ndisc.h"

	#include "alloc-util.h"
	#include "event-util.h"
	#include "fd-util.h"
	#include "icmp6-util.h"
	#include "in-addr-util.h"
	#include "memory-util.h"
	#include "ndisc-internal.h"
	#include "ndisc-router.h"
	#include "network-common.h"
	#include "random-util.h"
	#include "socket-util.h"
	#include "string-table.h"
	#include "string-util.h"

	#define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)

	static const char * const ndisc_event_table[_SD_NDISC_EVENT_MAX] = {
	[SD_NDISC_EVENT_TIMEOUT] = "timeout",
	[SD_NDISC_EVENT_ROUTER] = "router",
	};

	DEFINE_STRING_TABLE_LOOKUP(ndisc_event, sd_ndisc_event_t);

	static void ndisc_callback(sd_ndisc ndisc, sd_ndisc_event_t event, sd_ndisc_router rt) {
	assert(ndisc);
	assert(event >= 0 && event < _SD_NDISC_EVENT_MAX);

	if (!ndisc->callback)
	return (void) log_ndisc(ndisc, "Received '%s' event.", ndisc_event_to_string(event));

	log_ndisc(ndisc, "Invoking callback for '%s' event.", ndisc_event_to_string(event));
	ndisc->callback(ndisc, event, rt, ndisc->userdata);
	}

	int sd_ndisc_set_callback(
	sd_ndisc *nd,
	sd_ndisc_callback_t callback,
	void *userdata) {

	assert_return(nd, -EINVAL);

	nd->callback = callback;
	nd->userdata = userdata;

	return 0;
	}

	int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) {
	assert_return(nd, -EINVAL);
	assert_return(ifindex > 0, -EINVAL);
	assert_return(nd->fd < 0, -EBUSY);

	nd->ifindex = ifindex;
	return 0;
	}

	int sd_ndisc_set_ifname(sd_ndisc nd, const char ifname) {
	assert_return(nd, -EINVAL);
	assert_return(ifname, -EINVAL);

	if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
	return -EINVAL;

	return free_and_strdup(&nd->ifname, ifname);
	}

	int sd_ndisc_get_ifname(sd_ndisc nd, const char *ret) {
	int r;

	assert_return(nd, -EINVAL);

	r = get_ifname(nd->ifindex, &nd->ifname);
	if (r < 0)
	return r;

	if (ret)
	*ret = nd->ifname;

	return 0;
	}

	int sd_ndisc_set_mac(sd_ndisc nd, const struct ether_addr mac_addr) {
	assert_return(nd, -EINVAL);

	if (mac_addr)
	nd->mac_addr = *mac_addr;
	else
	zero(nd->mac_addr);

	return 0;
	}

	int sd_ndisc_attach_event(sd_ndisc nd, sd_event event, int64_t priority) {
	int r;

	assert_return(nd, -EINVAL);
	assert_return(nd->fd < 0, -EBUSY);
	assert_return(!nd->event, -EBUSY);

	if (event)
	nd->event = sd_event_ref(event);
	else {
	r = sd_event_default(&nd->event);
	if (r < 0)
	return 0;
	}

	nd->event_priority = priority;

	return 0;
	}

	int sd_ndisc_detach_event(sd_ndisc *nd) {

	assert_return(nd, -EINVAL);
	assert_return(nd->fd < 0, -EBUSY);

	nd->event = sd_event_unref(nd->event);
	return 0;
	}

	sd_event sd_ndisc_get_event(sd_ndisc nd) {
	assert_return(nd, NULL);

	return nd->event;
	}

	static void ndisc_reset(sd_ndisc *nd) {
	assert(nd);

	(void) event_source_disable(nd->timeout_event_source);
	(void) event_source_disable(nd->timeout_no_ra);
	nd->retransmit_time = 0;
	nd->recv_event_source = sd_event_source_disable_unref(nd->recv_event_source);
	nd->fd = safe_close(nd->fd);
	}

	static sd_ndisc ndisc_free(sd_ndisc nd) {
	assert(nd);

	ndisc_reset(nd);

	sd_event_source_unref(nd->timeout_event_source);
	sd_event_source_unref(nd->timeout_no_ra);
	sd_ndisc_detach_event(nd);

	free(nd->ifname);
	return mfree(nd);
	}

	DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc, sd_ndisc, ndisc_free);

	int sd_ndisc_new(sd_ndisc **ret) {
	_cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL;

	assert_return(ret, -EINVAL);

	nd = new(sd_ndisc, 1);
	if (!nd)
	return -ENOMEM;

	*nd = (sd_ndisc) {
	.n_ref = 1,
	.fd = -EBADF,
	};

	*ret = TAKE_PTR(nd);

	return 0;
	}

	static int ndisc_handle_datagram(sd_ndisc nd, sd_ndisc_router rt) {
	int r;

	assert(nd);
	assert(rt);

	r = ndisc_router_parse(nd, rt);
	if (r < 0)
	return r;

	log_ndisc(nd, "Received Router Advertisement: flags %s preference %s lifetime %" PRIu16 " sec",
	rt->flags & ND_RA_FLAG_MANAGED ? "MANAGED" : rt->flags & ND_RA_FLAG_OTHER ? "OTHER" : "none",
	rt->preference == SD_NDISC_PREFERENCE_HIGH ? "high" : rt->preference == SD_NDISC_PREFERENCE_LOW ? "low" : "medium",
	rt->lifetime);

	ndisc_callback(nd, SD_NDISC_EVENT_ROUTER, rt);
	return 0;
	}

	static int ndisc_recv(sd_event_source s, int fd, uint32_t revents, void userdata) {
	_cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
	sd_ndisc *nd = ASSERT_PTR(userdata);
	ssize_t buflen;
	int r;

	assert(s);
	assert(nd->event);

	buflen = next_datagram_size_fd(fd);
	if (buflen < 0) {
	if (ERRNO_IS_TRANSIENT(buflen) \|\| ERRNO_IS_DISCONNECT(buflen))
	return 0;

	log_ndisc_errno(nd, buflen, "Failed to determine datagram size to read, ignoring: %m");
	return 0;
	}

	rt = ndisc_router_new(buflen);
	if (!rt)
	return -ENOMEM;

	r = icmp6_receive(fd, NDISC_ROUTER_RAW(rt), rt->raw_size, &rt->address, &rt->timestamp);
	if (r < 0) {
	if (ERRNO_IS_TRANSIENT(r) \|\| ERRNO_IS_DISCONNECT(r))
	return 0;

	switch (r) {
	case -EADDRNOTAVAIL:
	log_ndisc(nd, "Received RA from non-link-local address %s. Ignoring.",
	IN6_ADDR_TO_STRING(&rt->address));
	break;

	case -EMULTIHOP:
	log_ndisc(nd, "Received RA with invalid hop limit. Ignoring.");
	break;

	case -EPFNOSUPPORT:
	log_ndisc(nd, "Received invalid source address from ICMPv6 socket. Ignoring.");
	break;

	default:
	log_ndisc_errno(nd, r, "Unexpected error while reading from ICMPv6, ignoring: %m");
	break;
	}

	return 0;
	}

	(void) event_source_disable(nd->timeout_event_source);
	(void) ndisc_handle_datagram(nd, rt);
	return 0;
	}

	static usec_t ndisc_timeout_compute_random(usec_t val) {
	/* compute a time that is random within ±10% of the given value */
	return val - val / 10 +
	(random_u64() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
	}

	static int ndisc_timeout(sd_event_source s, uint64_t usec, void userdata) {
	sd_ndisc *nd = ASSERT_PTR(userdata);
	usec_t time_now;
	int r;

	assert(s);
	assert(nd->event);

	assert_se(sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now) >= 0);

	if (!nd->retransmit_time)
	nd->retransmit_time = ndisc_timeout_compute_random(NDISC_ROUTER_SOLICITATION_INTERVAL);
	else {
	if (nd->retransmit_time > NDISC_MAX_ROUTER_SOLICITATION_INTERVAL / 2)
	nd->retransmit_time = ndisc_timeout_compute_random(NDISC_MAX_ROUTER_SOLICITATION_INTERVAL);
	else
	nd->retransmit_time += ndisc_timeout_compute_random(nd->retransmit_time);
	}

	r = event_reset_time(nd->event, &nd->timeout_event_source,
	CLOCK_BOOTTIME,
	time_now + nd->retransmit_time, 10 * USEC_PER_MSEC,
	ndisc_timeout, nd,
	nd->event_priority, "ndisc-timeout-no-ra", true);
	if (r < 0)
	goto fail;

	r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr);
	if (r < 0)
	log_ndisc_errno(nd, r, "Failed to send Router Solicitation, next solicitation in %s, ignoring: %m",
	FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));
	else
	log_ndisc(nd, "Sent Router Solicitation, next solicitation in %s",
	FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));

	return 0;

	fail:
	(void) sd_ndisc_stop(nd);
	return 0;
	}

	static int ndisc_timeout_no_ra(sd_event_source s, uint64_t usec, void userdata) {
	sd_ndisc *nd = ASSERT_PTR(userdata);

	assert(s);

	log_ndisc(nd, "No RA received before link confirmation timeout");

	(void) event_source_disable(nd->timeout_no_ra);
	ndisc_callback(nd, SD_NDISC_EVENT_TIMEOUT, NULL);

	return 0;
	}

	int sd_ndisc_stop(sd_ndisc *nd) {
	if (!nd)
	return 0;

	if (nd->fd < 0)
	return 0;

	log_ndisc(nd, "Stopping IPv6 Router Solicitation client");

	ndisc_reset(nd);
	return 1;
	}

	int sd_ndisc_start(sd_ndisc *nd) {
	int r;
	usec_t time_now;

	assert_return(nd, -EINVAL);
	assert_return(nd->event, -EINVAL);
	assert_return(nd->ifindex > 0, -EINVAL);

	if (nd->fd >= 0)
	return 0;

	assert(!nd->recv_event_source);

	r = sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now);
	if (r < 0)
	goto fail;

	nd->fd = icmp6_bind_router_solicitation(nd->ifindex);
	if (nd->fd < 0)
	return nd->fd;

	r = sd_event_add_io(nd->event, &nd->recv_event_source, nd->fd, EPOLLIN, ndisc_recv, nd);
	if (r < 0)
	goto fail;

	r = sd_event_source_set_priority(nd->recv_event_source, nd->event_priority);
	if (r < 0)
	goto fail;

	(void) sd_event_source_set_description(nd->recv_event_source, "ndisc-receive-message");

	r = event_reset_time(nd->event, &nd->timeout_event_source,
	CLOCK_BOOTTIME,
	time_now + USEC_PER_SEC / 2, 1 * USEC_PER_SEC, /* See RFC 8415 sec. 18.2.1 */
	ndisc_timeout, nd,
	nd->event_priority, "ndisc-timeout", true);
	if (r < 0)
	goto fail;

	r = event_reset_time(nd->event, &nd->timeout_no_ra,
	CLOCK_BOOTTIME,
	time_now + NDISC_TIMEOUT_NO_RA_USEC, 10 * USEC_PER_MSEC,
	ndisc_timeout_no_ra, nd,
	nd->event_priority, "ndisc-timeout-no-ra", true);
	if (r < 0)
	goto fail;

	log_ndisc(nd, "Started IPv6 Router Solicitation client");
	return 1;

	fail:
	ndisc_reset(nd);
	return r;
	}