[thirdparty/systemd.git] / src / libsystemd-network / sd-radv.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
  Copyright © 2017 Intel Corporation. All rights reserved.
***/

#include <linux/ipv6.h>
#include <netinet/icmp6.h>
#include <netinet/in.h>

#include "sd-ndisc-protocol.h"
#include "sd-ndisc-router-solicit.h"
#include "sd-radv.h"

#include "alloc-util.h"
#include "event-util.h"
#include "fd-util.h"
#include "icmp6-packet.h"
#include "icmp6-util.h"
#include "in-addr-util.h"
#include "memory-util.h"
#include "ndisc-option.h"
#include "ndisc-router-solicit-internal.h"
#include "network-common.h"
#include "radv-internal.h"
#include "random-util.h"
#include "set.h"
#include "socket-util.h"
#include "string-util.h"

int sd_radv_new(sd_radv **ret) {
        _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;

        assert_return(ret, -EINVAL);

        ra = new(sd_radv, 1);
        if (!ra)
                return -ENOMEM;

        *ra = (sd_radv) {
                .n_ref = 1,
                .fd = -EBADF,
                .lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
        };

        *ret = TAKE_PTR(ra);

        return 0;
}

int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
        int r;

        assert_return(ra, -EINVAL);
        assert_return(!ra->event, -EBUSY);

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

        ra->event_priority = priority;

        return 0;
}

int sd_radv_detach_event(sd_radv *ra) {
        assert_return(ra, -EINVAL);

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

sd_event *sd_radv_get_event(sd_radv *ra) {
        assert_return(ra, NULL);

        return ra->event;
}

int sd_radv_is_running(sd_radv *ra) {
        if (!ra)
                return false;

        return ra->state != RADV_STATE_IDLE;
}

static void radv_reset(sd_radv *ra) {
        assert(ra);

        (void) event_source_disable(ra->timeout_event_source);

        ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);

        ra->ra_sent = 0;
}

static sd_radv *radv_free(sd_radv *ra) {
        if (!ra)
                return NULL;

        radv_reset(ra);

        sd_event_source_unref(ra->timeout_event_source);
        sd_radv_detach_event(ra);

        ra->fd = safe_close(ra->fd);
        free(ra->ifname);

        set_free(ra->options);

        return mfree(ra);
}

DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);

static bool router_lifetime_is_valid(usec_t lifetime_usec) {
        assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
        return lifetime_usec == 0 ||
                (lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
                 lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
}

static int radv_send_router_on_stop(sd_radv *ra) {
        static const struct nd_router_advert adv = {
                .nd_ra_type = ND_ROUTER_ADVERT,
        };

        _cleanup_set_free_ Set *options = NULL;
        struct ether_addr mac_addr;
        usec_t time_now;
        int r;

        assert(ra);

        r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
        if (r < 0)
                return r;

        /* On stop, we only send source link-layer address option. */
        if (ndisc_option_get_mac(ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &mac_addr) >= 0) {
                r = ndisc_option_set_link_layer_address(&options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &mac_addr);
                if (r < 0)
                        return r;
        }

        return ndisc_send(ra->fd, &IN6_ADDR_ALL_NODES_MULTICAST, &adv.nd_ra_hdr, options, time_now);
}

static int radv_send_router(sd_radv *ra, const struct in6_addr *dst) {
        assert(ra);

        struct nd_router_advert adv = {
                .nd_ra_type = ND_ROUTER_ADVERT,
                .nd_ra_router_lifetime = usec_to_be16_sec(ra->lifetime_usec),
                .nd_ra_reachable = usec_to_be32_msec(ra->reachable_usec),
                .nd_ra_retransmit = usec_to_be32_msec(ra->retransmit_usec),
        };
        usec_t time_now;
        int r;

        r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
        if (r < 0)
                return r;

        /* The nd_ra_curhoplimit and nd_ra_flags_reserved fields cannot specified with nd_ra_router_lifetime
         * simultaneously in the structured initializer in the above. */
        adv.nd_ra_curhoplimit = ra->hop_limit;
        /* RFC 4191, Section 2.2,
         * "...If the Router Lifetime is zero, the preference value MUST be set to (00) by the sender..." */
        adv.nd_ra_flags_reserved = ra->flags | (ra->lifetime_usec > 0 ? (ra->preference << 3) : 0);

        return ndisc_send(ra->fd,
                          (dst && in6_addr_is_set(dst)) ? dst : &IN6_ADDR_ALL_NODES_MULTICAST,
                          &adv.nd_ra_hdr, ra->options, time_now);
}

static int radv_process_packet(sd_radv *ra, ICMP6Packet *packet) {
        int r;

        assert(ra);
        assert(packet);

        if (icmp6_packet_get_type(packet) != ND_ROUTER_SOLICIT)
                return log_radv_errno(ra, SYNTHETIC_ERRNO(EBADMSG), "Received ICMP6 packet with unexpected type, ignoring.");

        _cleanup_(sd_ndisc_router_solicit_unrefp) sd_ndisc_router_solicit *rs = NULL;
        rs = ndisc_router_solicit_new(packet);
        if (!rs)
                return log_oom_debug();

        r = ndisc_router_solicit_parse(ra, rs);
        if (r < 0)
                return r;

        struct in6_addr src;
        r = sd_ndisc_router_solicit_get_sender_address(rs, &src);
        if (r == -ENODATA) /* null address is allowed */
                return sd_radv_send(ra); /* When an unsolicited RA, we need to also update timer. */
        if (r < 0)
                return log_radv_errno(ra, r, "Failed to get sender address of RS, ignoring: %m");
        if (in6_addr_equal(&src, &ra->ipv6ll))
                /* This should be definitely caused by a misconfiguration. If we send RA to ourself, the
                 * kernel complains about that. Let's ignore the packet. */
                return log_radv_errno(ra, SYNTHETIC_ERRNO(EADDRINUSE), "Received RS from the same interface, ignoring.");

        r = radv_send_router(ra, &src);
        if (r < 0)
                return log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", IN6_ADDR_TO_STRING(&src));

        log_radv(ra, "Sent solicited Router Advertisement to %s.", IN6_ADDR_TO_STRING(&src));
        return 0;
}

static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
        _cleanup_(icmp6_packet_unrefp) ICMP6Packet *packet = NULL;
        sd_radv *ra = ASSERT_PTR(userdata);
        int r;

        assert(fd >= 0);

        r = icmp6_packet_receive(fd, &packet);
        if (r < 0) {
                log_radv_errno(ra, r, "Failed to receive ICMPv6 packet, ignoring: %m");
                return 0;
        }

        (void) radv_process_packet(ra, packet);
        return 0;
}

static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
        sd_radv *ra = ASSERT_PTR(userdata);

        if (sd_radv_send(ra) < 0)
                (void) sd_radv_stop(ra);

        return 0;
}

int sd_radv_send(sd_radv *ra) {
        usec_t min_timeout, max_timeout, time_now, timeout;
        int r;

        assert_return(ra, -EINVAL);
        assert_return(ra->event, -EINVAL);
        assert_return(sd_radv_is_running(ra), -EINVAL);
        assert(router_lifetime_is_valid(ra->lifetime_usec));

        r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
        if (r < 0)
                return r;

        r = radv_send_router(ra, NULL);
        if (r < 0)
                return log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");

        ra->ra_sent++;

        /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
        if (ra->ra_sent <= RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
                max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
        else
                max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;

        /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
         * so lower the interval here */
        if (ra->lifetime_usec > 0)
                max_timeout = MIN(max_timeout, ra->lifetime_usec);

        if (max_timeout >= 9 * USEC_PER_SEC)
                min_timeout = max_timeout / 3;
        else
                min_timeout = max_timeout * 3 / 4;

        /* RFC 4861, Section 6.2.1.
         * MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
         * MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
        assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
        assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
        assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
        assert(min_timeout <= max_timeout * 3 / 4);

        timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
        log_radv(ra, "Sent unsolicited Router Advertisement. Next advertisement will be in %s.",
                 FORMAT_TIMESPAN(timeout, USEC_PER_SEC));

        return event_reset_time(
                        ra->event, &ra->timeout_event_source,
                        CLOCK_BOOTTIME,
                        usec_add(time_now, timeout), MSEC_PER_SEC,
                        radv_timeout, ra,
                        ra->event_priority, "radv-timeout", true);
}

int sd_radv_stop(sd_radv *ra) {
        int r;

        if (!sd_radv_is_running(ra))
                return 0; /* Already stopped. */

        log_radv(ra, "Stopping IPv6 Router Advertisement daemon");

        /* RFC 4861, Section 6.2.5:
         * the router SHOULD transmit one or more (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
         * multicast Router Advertisements on the interface with a Router Lifetime field of zero. */
        r = radv_send_router_on_stop(ra);
        if (r < 0)
                log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero, ignoring: %m");

        radv_reset(ra);
        ra->fd = safe_close(ra->fd);
        ra->state = RADV_STATE_IDLE;

        return 0;
}

static int radv_setup_recv_event(sd_radv *ra) {
        int r;

        assert(ra);
        assert(ra->event);
        assert(ra->ifindex > 0);

        _cleanup_close_ int fd = -EBADF;
        fd = icmp6_bind(ra->ifindex, /* is_router = */ true);
        if (fd < 0)
                return fd;

        _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
        r = sd_event_add_io(ra->event, &s, fd, EPOLLIN, radv_recv, ra);
        if (r < 0)
                return r;

        r = sd_event_source_set_priority(s, ra->event_priority);
        if (r < 0)
                return r;

        (void) sd_event_source_set_description(s, "radv-receive-message");

        ra->fd = TAKE_FD(fd);
        ra->recv_event_source = TAKE_PTR(s);
        return 0;
}

int sd_radv_start(sd_radv *ra) {
        int r;

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

        if (sd_radv_is_running(ra))
                return 0; /* Already started. */

        r = radv_setup_recv_event(ra);
        if (r < 0)
                goto fail;

        r = event_reset_time(ra->event, &ra->timeout_event_source,
                             CLOCK_BOOTTIME,
                             0, 0,
                             radv_timeout, ra,
                             ra->event_priority, "radv-timeout", true);
        if (r < 0)
                goto fail;

        ra->state = RADV_STATE_ADVERTISING;

        log_radv(ra, "Started IPv6 Router Advertisement daemon");

        return 0;

 fail:
        radv_reset(ra);

        return r;
}

int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
        assert_return(ra, -EINVAL);
        assert_return(!sd_radv_is_running(ra), -EBUSY);
        assert_return(ifindex > 0, -EINVAL);

        ra->ifindex = ifindex;
        return 0;
}

int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
        assert_return(ra, -EINVAL);
        assert_return(ifname, -EINVAL);

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

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

int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
        int r;

        assert_return(ra, -EINVAL);

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

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

        return 0;
}

int sd_radv_set_link_local_address(sd_radv *ra, const struct in6_addr *addr) {
        assert_return(ra, -EINVAL);
        assert_return(!addr || in6_addr_is_link_local(addr), -EINVAL);

        if (addr)
                ra->ipv6ll = *addr;
        else
                zero(ra->ipv6ll);

        return 0;
}

/* Managing RA header. */

int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
        assert_return(ra, -EINVAL);

        ra->hop_limit = hop_limit;
        return 0;
}

int sd_radv_set_reachable_time(sd_radv *ra, uint64_t usec) {
        assert_return(ra, -EINVAL);

        ra->reachable_usec = usec;
        return 0;
}

int sd_radv_set_retransmit(sd_radv *ra, uint64_t usec) {
        assert_return(ra, -EINVAL);

        ra->retransmit_usec = usec;
        return 0;
}

int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t usec) {
        assert_return(ra, -EINVAL);

        if (!router_lifetime_is_valid(usec))
                return -EINVAL;

        ra->lifetime_usec = usec;
        return 0;
}

int sd_radv_set_managed_information(sd_radv *ra, int b) {
        assert_return(ra, -EINVAL);

        SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, b);
        return 0;
}

int sd_radv_set_other_information(sd_radv *ra, int b) {
        assert_return(ra, -EINVAL);

        SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, b);
        return 0;
}

int sd_radv_set_preference(sd_radv *ra, uint8_t preference) {
        assert_return(ra, -EINVAL);
        assert_return(IN_SET(preference,
                             SD_NDISC_PREFERENCE_LOW,
                             SD_NDISC_PREFERENCE_MEDIUM,
                             SD_NDISC_PREFERENCE_HIGH), -EINVAL);

        ra->preference = preference;
        return 0;
}

/* Managing options. */

int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
        assert_return(ra, -EINVAL);

        return ndisc_option_set_link_layer_address(&ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, mac_addr);
}

void sd_radv_unset_mac(sd_radv *ra) {
        if (!ra)
                return;

        ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS);
}

int sd_radv_add_prefix(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen,
                uint8_t flags,
                uint64_t valid_lifetime_usec,
                uint64_t preferred_lifetime_usec,
                uint64_t valid_until,
                uint64_t preferred_until) {

        assert_return(ra, -EINVAL);
        assert_return(prefix, -EINVAL);

        sd_ndisc_option *opt;
        SET_FOREACH(opt, ra->options) {
                if (opt->type != SD_NDISC_OPTION_PREFIX_INFORMATION)
                        continue;

                if (!in6_addr_prefix_intersect(&opt->prefix.address, opt->prefix.prefixlen, prefix, prefixlen))
                        continue; /* no intersection */

                if (opt->prefix.prefixlen == prefixlen)
                        break; /* same prefix */

                return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
                                      "IPv6 prefix %s conflicts with %s, ignoring.",
                                      IN6_ADDR_PREFIX_TO_STRING(prefix, prefixlen),
                                      IN6_ADDR_PREFIX_TO_STRING(&opt->prefix.address, opt->prefix.prefixlen));
        }

        return ndisc_option_set_prefix(
                        &ra->options,
                        flags,
                        prefixlen,
                        prefix,
                        valid_lifetime_usec,
                        preferred_lifetime_usec,
                        valid_until,
                        preferred_until);
}

void sd_radv_remove_prefix(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen) {

        if (!ra || !prefix)
                return;

        ndisc_option_remove(ra->options,
                            &(sd_ndisc_option) {
                                    .type = SD_NDISC_OPTION_PREFIX_INFORMATION,
                                    .prefix.prefixlen = prefixlen,
                                    .prefix.address = *prefix,
                            });
}

int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
        assert_return(ra, -EINVAL);
        assert_return(mtu >= IPV6_MIN_MTU, -EINVAL);

        return ndisc_option_set_mtu(&ra->options, mtu);
}

void sd_radv_unset_mtu(sd_radv *ra) {
        if (!ra)
                return;

        ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_MTU);
}

int sd_radv_set_home_agent(sd_radv *ra, uint16_t preference, uint64_t lifetime_usec, uint64_t valid_until) {
        assert_return(ra, -EINVAL);

        ra->flags |= ND_RA_FLAG_HOME_AGENT;
        return ndisc_option_set_home_agent(&ra->options, preference, lifetime_usec, valid_until);
}

void sd_radv_unset_home_agent(sd_radv *ra) {
        if (!ra)
                return;

        ra->flags &= ~ND_RA_FLAG_HOME_AGENT;
        ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_HOME_AGENT);
}

int sd_radv_add_route(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen,
                uint8_t preference,
                uint64_t lifetime_usec,
                uint64_t valid_until) {

        assert_return(ra, -EINVAL);
        assert_return(prefix, -EINVAL);

        return ndisc_option_set_route(
                        &ra->options,
                        preference,
                        prefixlen,
                        prefix,
                        lifetime_usec,
                        valid_until);
}

void sd_radv_remove_route(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen) {

        if (!ra || !prefix)
                return;

        ndisc_option_remove(ra->options,
                            &(sd_ndisc_option) {
                                    .type = SD_NDISC_OPTION_ROUTE_INFORMATION,
                                    .route.prefixlen = prefixlen,
                                    .route.address = *prefix,
                            });
}

int sd_radv_add_rdnss(
                sd_radv *ra,
                size_t n_dns,
                const struct in6_addr *dns,
                uint64_t lifetime_usec,
                uint64_t valid_until) {

        assert_return(ra, -EINVAL);
        assert_return(dns, -EINVAL);

        return ndisc_option_set_rdnss(
                        &ra->options,
                        n_dns,
                        dns,
                        lifetime_usec,
                        valid_until);
}

void sd_radv_clear_rdnss(sd_radv *ra) {
        if (!ra)
                return;

        sd_ndisc_option *opt;
        SET_FOREACH(opt, ra->options)
                if (opt->type == SD_NDISC_OPTION_RDNSS)
                        ndisc_option_remove(ra->options, opt);
}

int sd_radv_add_dnssl(
                sd_radv *ra,
                char * const *domains,
                uint64_t lifetime_usec,
                uint64_t valid_until) {

        assert_return(ra, -EINVAL);

        return ndisc_option_set_dnssl(
                        &ra->options,
                        domains,
                        lifetime_usec,
                        valid_until);
}

void sd_radv_clear_dnssl(sd_radv *ra) {
        if (!ra)
                return;

        sd_ndisc_option *opt;
        SET_FOREACH(opt, ra->options)
                if (opt->type == SD_NDISC_OPTION_DNSSL)
                        ndisc_option_remove(ra->options, opt);
}

int sd_radv_set_captive_portal(sd_radv *ra, const char *portal) {
        assert_return(ra, -EINVAL);
        assert_return(portal, -EINVAL);

        return ndisc_option_set_captive_portal(&ra->options, portal);
}

void sd_radv_unset_captive_portal(sd_radv *ra) {
        if (!ra)
                return;

        ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_CAPTIVE_PORTAL);
}

int sd_radv_add_prefix64(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen,
                uint64_t lifetime_usec,
                uint64_t valid_until) {

        assert_return(ra, -EINVAL);
        assert_return(prefix, -EINVAL);

        return ndisc_option_set_prefix64(
                        &ra->options,
                        prefixlen,
                        prefix,
                        lifetime_usec,
                        valid_until);
}

void sd_radv_remove_prefix64(
                sd_radv *ra,
                const struct in6_addr *prefix,
                uint8_t prefixlen) {

        if (!ra || !prefix)
                return;

        ndisc_option_remove(ra->options,
                            &(sd_ndisc_option) {
                                    .type = SD_NDISC_OPTION_PREF64,
                                    .prefix64.prefixlen = prefixlen,
                                    .prefix64.prefix = *prefix,
                            });
}
Commit	Line	Data
	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2	/***
	3	Copyright © 2017 Intel Corporation. All rights reserved.
	4	***/
	5
	6	#include <linux/ipv6.h>
	7	#include <netinet/icmp6.h>
	8	#include <netinet/in.h>
	9
	10	#include "sd-ndisc-protocol.h"
	11	#include "sd-ndisc-router-solicit.h"
	12	#include "sd-radv.h"
	13
	14	#include "alloc-util.h"
	15	#include "event-util.h"
	16	#include "fd-util.h"
	17	#include "icmp6-packet.h"
	18	#include "icmp6-util.h"
	19	#include "in-addr-util.h"
	20	#include "memory-util.h"
	21	#include "ndisc-option.h"
	22	#include "ndisc-router-solicit-internal.h"
	23	#include "network-common.h"
	24	#include "radv-internal.h"
	25	#include "random-util.h"
	26	#include "set.h"
	27	#include "socket-util.h"
	28	#include "string-util.h"
	29
	30	int sd_radv_new(sd_radv **ret) {
	31	_cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
	32
	33	assert_return(ret, -EINVAL);
	34
	35	ra = new(sd_radv, 1);
	36	if (!ra)
	37	return -ENOMEM;
	38
	39	*ra = (sd_radv) {
	40	.n_ref = 1,
	41	.fd = -EBADF,
	42	.lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
	43	};
	44
	45	*ret = TAKE_PTR(ra);
	46
	47	return 0;
	48	}
	49
	50	int sd_radv_attach_event(sd_radv ra, sd_event event, int64_t priority) {
	51	int r;
	52
	53	assert_return(ra, -EINVAL);
	54	assert_return(!ra->event, -EBUSY);
	55
	56	if (event)
	57	ra->event = sd_event_ref(event);
	58	else {
	59	r = sd_event_default(&ra->event);
	60	if (r < 0)
	61	return 0;
	62	}
	63
	64	ra->event_priority = priority;
	65
	66	return 0;
	67	}
	68
	69	int sd_radv_detach_event(sd_radv *ra) {
	70	assert_return(ra, -EINVAL);
	71
	72	ra->event = sd_event_unref(ra->event);
	73	return 0;
	74	}
	75
	76	sd_event sd_radv_get_event(sd_radv ra) {
	77	assert_return(ra, NULL);
	78
	79	return ra->event;
	80	}
	81
	82	int sd_radv_is_running(sd_radv *ra) {
	83	if (!ra)
	84	return false;
	85
	86	return ra->state != RADV_STATE_IDLE;
	87	}
	88
	89	static void radv_reset(sd_radv *ra) {
	90	assert(ra);
	91
	92	(void) event_source_disable(ra->timeout_event_source);
	93
	94	ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
	95
	96	ra->ra_sent = 0;
	97	}
	98
	99	static sd_radv radv_free(sd_radv ra) {
	100	if (!ra)
	101	return NULL;
	102
	103	radv_reset(ra);
	104
	105	sd_event_source_unref(ra->timeout_event_source);
	106	sd_radv_detach_event(ra);
	107
	108	ra->fd = safe_close(ra->fd);
	109	free(ra->ifname);
	110
	111	set_free(ra->options);
	112
	113	return mfree(ra);
	114	}
	115
	116	DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
	117
	118	static bool router_lifetime_is_valid(usec_t lifetime_usec) {
	119	assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
	120	return lifetime_usec == 0 \|\|
	121	(lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
	122	lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
	123	}
	124
	125	static int radv_send_router_on_stop(sd_radv *ra) {
	126	static const struct nd_router_advert adv = {
	127	.nd_ra_type = ND_ROUTER_ADVERT,
	128	};
	129
	130	_cleanup_set_free_ Set *options = NULL;
	131	struct ether_addr mac_addr;
	132	usec_t time_now;
	133	int r;
	134
	135	assert(ra);
	136
	137	r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
	138	if (r < 0)
	139	return r;
	140
	141	/* On stop, we only send source link-layer address option. */
	142	if (ndisc_option_get_mac(ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &mac_addr) >= 0) {
	143	r = ndisc_option_set_link_layer_address(&options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &mac_addr);
	144	if (r < 0)
	145	return r;
	146	}
	147
	148	return ndisc_send(ra->fd, &IN6_ADDR_ALL_NODES_MULTICAST, &adv.nd_ra_hdr, options, time_now);
	149	}
	150
	151	static int radv_send_router(sd_radv ra, const struct in6_addr dst) {
	152	assert(ra);
	153
	154	struct nd_router_advert adv = {
	155	.nd_ra_type = ND_ROUTER_ADVERT,
	156	.nd_ra_router_lifetime = usec_to_be16_sec(ra->lifetime_usec),
	157	.nd_ra_reachable = usec_to_be32_msec(ra->reachable_usec),
	158	.nd_ra_retransmit = usec_to_be32_msec(ra->retransmit_usec),
	159	};
	160	usec_t time_now;
	161	int r;
	162
	163	r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
	164	if (r < 0)
	165	return r;
	166
	167	/* The nd_ra_curhoplimit and nd_ra_flags_reserved fields cannot specified with nd_ra_router_lifetime
	168	* simultaneously in the structured initializer in the above. */
	169	adv.nd_ra_curhoplimit = ra->hop_limit;
	170	/* RFC 4191, Section 2.2,
	171	* "...If the Router Lifetime is zero, the preference value MUST be set to (00) by the sender..." */
	172	adv.nd_ra_flags_reserved = ra->flags \| (ra->lifetime_usec > 0 ? (ra->preference << 3) : 0);
	173
	174	return ndisc_send(ra->fd,
	175	(dst && in6_addr_is_set(dst)) ? dst : &IN6_ADDR_ALL_NODES_MULTICAST,
	176	&adv.nd_ra_hdr, ra->options, time_now);
	177	}
	178
	179	static int radv_process_packet(sd_radv ra, ICMP6Packet packet) {
	180	int r;
	181
	182	assert(ra);
	183	assert(packet);
	184
	185	if (icmp6_packet_get_type(packet) != ND_ROUTER_SOLICIT)
	186	return log_radv_errno(ra, SYNTHETIC_ERRNO(EBADMSG), "Received ICMP6 packet with unexpected type, ignoring.");
	187
	188	_cleanup_(sd_ndisc_router_solicit_unrefp) sd_ndisc_router_solicit *rs = NULL;
	189	rs = ndisc_router_solicit_new(packet);
	190	if (!rs)
	191	return log_oom_debug();
	192
	193	r = ndisc_router_solicit_parse(ra, rs);
	194	if (r < 0)
	195	return r;
	196
	197	struct in6_addr src;
	198	r = sd_ndisc_router_solicit_get_sender_address(rs, &src);
	199	if (r == -ENODATA) /* null address is allowed */
	200	return sd_radv_send(ra); /* When an unsolicited RA, we need to also update timer. */
	201	if (r < 0)
	202	return log_radv_errno(ra, r, "Failed to get sender address of RS, ignoring: %m");
	203	if (in6_addr_equal(&src, &ra->ipv6ll))
	204	/* This should be definitely caused by a misconfiguration. If we send RA to ourself, the
	205	* kernel complains about that. Let's ignore the packet. */
	206	return log_radv_errno(ra, SYNTHETIC_ERRNO(EADDRINUSE), "Received RS from the same interface, ignoring.");
	207
	208	r = radv_send_router(ra, &src);
	209	if (r < 0)
	210	return log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", IN6_ADDR_TO_STRING(&src));
	211
	212	log_radv(ra, "Sent solicited Router Advertisement to %s.", IN6_ADDR_TO_STRING(&src));
	213	return 0;
	214	}
	215
	216	static int radv_recv(sd_event_source s, int fd, uint32_t revents, void userdata) {
	217	_cleanup_(icmp6_packet_unrefp) ICMP6Packet *packet = NULL;
	218	sd_radv *ra = ASSERT_PTR(userdata);
	219	int r;
	220
	221	assert(fd >= 0);
	222
	223	r = icmp6_packet_receive(fd, &packet);
	224	if (r < 0) {
	225	log_radv_errno(ra, r, "Failed to receive ICMPv6 packet, ignoring: %m");
	226	return 0;
	227	}
	228
	229	(void) radv_process_packet(ra, packet);
	230	return 0;
	231	}
	232
	233	static int radv_timeout(sd_event_source s, uint64_t usec, void userdata) {
	234	sd_radv *ra = ASSERT_PTR(userdata);
	235
	236	if (sd_radv_send(ra) < 0)
	237	(void) sd_radv_stop(ra);
	238
	239	return 0;
	240	}
	241
	242	int sd_radv_send(sd_radv *ra) {
	243	usec_t min_timeout, max_timeout, time_now, timeout;
	244	int r;
	245
	246	assert_return(ra, -EINVAL);
	247	assert_return(ra->event, -EINVAL);
	248	assert_return(sd_radv_is_running(ra), -EINVAL);
	249	assert(router_lifetime_is_valid(ra->lifetime_usec));
	250
	251	r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
	252	if (r < 0)
	253	return r;
	254
	255	r = radv_send_router(ra, NULL);
	256	if (r < 0)
	257	return log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
	258
	259	ra->ra_sent++;
	260
	261	/* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
	262	if (ra->ra_sent <= RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
	263	max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
	264	else
	265	max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
	266
	267	/* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
	268	* so lower the interval here */
	269	if (ra->lifetime_usec > 0)
	270	max_timeout = MIN(max_timeout, ra->lifetime_usec);
	271
	272	if (max_timeout >= 9 * USEC_PER_SEC)
	273	min_timeout = max_timeout / 3;
	274	else
	275	min_timeout = max_timeout * 3 / 4;
	276
	277	/* RFC 4861, Section 6.2.1.
	278	* MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
	279	* MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
	280	assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
	281	assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
	282	assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
	283	assert(min_timeout <= max_timeout * 3 / 4);
	284
	285	timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
	286	log_radv(ra, "Sent unsolicited Router Advertisement. Next advertisement will be in %s.",
	287	FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
	288
	289	return event_reset_time(
	290	ra->event, &ra->timeout_event_source,
	291	CLOCK_BOOTTIME,
	292	usec_add(time_now, timeout), MSEC_PER_SEC,
	293	radv_timeout, ra,
	294	ra->event_priority, "radv-timeout", true);
	295	}
	296
	297	int sd_radv_stop(sd_radv *ra) {
	298	int r;
	299
	300	if (!sd_radv_is_running(ra))
	301	return 0; /* Already stopped. */
	302
	303	log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
	304
	305	/* RFC 4861, Section 6.2.5:
	306	* the router SHOULD transmit one or more (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
	307	* multicast Router Advertisements on the interface with a Router Lifetime field of zero. */
	308	r = radv_send_router_on_stop(ra);
	309	if (r < 0)
	310	log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero, ignoring: %m");
	311
	312	radv_reset(ra);
	313	ra->fd = safe_close(ra->fd);
	314	ra->state = RADV_STATE_IDLE;
	315
	316	return 0;
	317	}
	318
	319	static int radv_setup_recv_event(sd_radv *ra) {
	320	int r;
	321
	322	assert(ra);
	323	assert(ra->event);
	324	assert(ra->ifindex > 0);
	325
	326	_cleanup_close_ int fd = -EBADF;
	327	fd = icmp6_bind(ra->ifindex, /* is_router = */ true);
	328	if (fd < 0)
	329	return fd;
	330
	331	_cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
	332	r = sd_event_add_io(ra->event, &s, fd, EPOLLIN, radv_recv, ra);
	333	if (r < 0)
	334	return r;
	335
	336	r = sd_event_source_set_priority(s, ra->event_priority);
	337	if (r < 0)
	338	return r;
	339
	340	(void) sd_event_source_set_description(s, "radv-receive-message");
	341
	342	ra->fd = TAKE_FD(fd);
	343	ra->recv_event_source = TAKE_PTR(s);
	344	return 0;
	345	}
	346
	347	int sd_radv_start(sd_radv *ra) {
	348	int r;
	349
	350	assert_return(ra, -EINVAL);
	351	assert_return(ra->event, -EINVAL);
	352	assert_return(ra->ifindex > 0, -EINVAL);
	353
	354	if (sd_radv_is_running(ra))
	355	return 0; /* Already started. */
	356
	357	r = radv_setup_recv_event(ra);
	358	if (r < 0)
	359	goto fail;
	360
	361	r = event_reset_time(ra->event, &ra->timeout_event_source,
	362	CLOCK_BOOTTIME,
	363	0, 0,
	364	radv_timeout, ra,
	365	ra->event_priority, "radv-timeout", true);
	366	if (r < 0)
	367	goto fail;
	368
	369	ra->state = RADV_STATE_ADVERTISING;
	370
	371	log_radv(ra, "Started IPv6 Router Advertisement daemon");
	372
	373	return 0;
	374
	375	fail:
	376	radv_reset(ra);
	377
	378	return r;
	379	}
	380
	381	int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
	382	assert_return(ra, -EINVAL);
	383	assert_return(!sd_radv_is_running(ra), -EBUSY);
	384	assert_return(ifindex > 0, -EINVAL);
	385
	386	ra->ifindex = ifindex;
	387	return 0;
	388	}
	389
	390	int sd_radv_set_ifname(sd_radv ra, const char ifname) {
	391	assert_return(ra, -EINVAL);
	392	assert_return(ifname, -EINVAL);
	393
	394	if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
	395	return -EINVAL;
	396
	397	return free_and_strdup(&ra->ifname, ifname);
	398	}
	399
	400	int sd_radv_get_ifname(sd_radv ra, const char *ret) {
	401	int r;
	402
	403	assert_return(ra, -EINVAL);
	404
	405	r = get_ifname(ra->ifindex, &ra->ifname);
	406	if (r < 0)
	407	return r;
	408
	409	if (ret)
	410	*ret = ra->ifname;
	411
	412	return 0;
	413	}
	414
	415	int sd_radv_set_link_local_address(sd_radv ra, const struct in6_addr addr) {
	416	assert_return(ra, -EINVAL);
	417	assert_return(!addr \|\| in6_addr_is_link_local(addr), -EINVAL);
	418
	419	if (addr)
	420	ra->ipv6ll = *addr;
	421	else
	422	zero(ra->ipv6ll);
	423
	424	return 0;
	425	}
	426
	427	/* Managing RA header. */
	428
	429	int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
	430	assert_return(ra, -EINVAL);
	431
	432	ra->hop_limit = hop_limit;
	433	return 0;
	434	}
	435
	436	int sd_radv_set_reachable_time(sd_radv *ra, uint64_t usec) {
	437	assert_return(ra, -EINVAL);
	438
	439	ra->reachable_usec = usec;
	440	return 0;
	441	}
	442
	443	int sd_radv_set_retransmit(sd_radv *ra, uint64_t usec) {
	444	assert_return(ra, -EINVAL);
	445
	446	ra->retransmit_usec = usec;
	447	return 0;
	448	}
	449
	450	int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t usec) {
	451	assert_return(ra, -EINVAL);
	452
	453	if (!router_lifetime_is_valid(usec))
	454	return -EINVAL;
	455
	456	ra->lifetime_usec = usec;
	457	return 0;
	458	}
	459
	460	int sd_radv_set_managed_information(sd_radv *ra, int b) {
	461	assert_return(ra, -EINVAL);
	462
	463	SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, b);
	464	return 0;
	465	}
	466
	467	int sd_radv_set_other_information(sd_radv *ra, int b) {
	468	assert_return(ra, -EINVAL);
	469
	470	SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, b);
	471	return 0;
	472	}
	473
	474	int sd_radv_set_preference(sd_radv *ra, uint8_t preference) {
	475	assert_return(ra, -EINVAL);
	476	assert_return(IN_SET(preference,
	477	SD_NDISC_PREFERENCE_LOW,
	478	SD_NDISC_PREFERENCE_MEDIUM,
	479	SD_NDISC_PREFERENCE_HIGH), -EINVAL);
	480
	481	ra->preference = preference;
	482	return 0;
	483	}
	484
	485	/* Managing options. */
	486
	487	int sd_radv_set_mac(sd_radv ra, const struct ether_addr mac_addr) {
	488	assert_return(ra, -EINVAL);
	489
	490	return ndisc_option_set_link_layer_address(&ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, mac_addr);
	491	}
	492
	493	void sd_radv_unset_mac(sd_radv *ra) {
	494	if (!ra)
	495	return;
	496
	497	ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS);
	498	}
	499
	500	int sd_radv_add_prefix(
	501	sd_radv *ra,
	502	const struct in6_addr *prefix,
	503	uint8_t prefixlen,
	504	uint8_t flags,
	505	uint64_t valid_lifetime_usec,
	506	uint64_t preferred_lifetime_usec,
	507	uint64_t valid_until,
	508	uint64_t preferred_until) {
	509
	510	assert_return(ra, -EINVAL);
	511	assert_return(prefix, -EINVAL);
	512
	513	sd_ndisc_option *opt;
	514	SET_FOREACH(opt, ra->options) {
	515	if (opt->type != SD_NDISC_OPTION_PREFIX_INFORMATION)
	516	continue;
	517
	518	if (!in6_addr_prefix_intersect(&opt->prefix.address, opt->prefix.prefixlen, prefix, prefixlen))
	519	continue; /* no intersection */
	520
	521	if (opt->prefix.prefixlen == prefixlen)
	522	break; /* same prefix */
	523
	524	return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
	525	"IPv6 prefix %s conflicts with %s, ignoring.",
	526	IN6_ADDR_PREFIX_TO_STRING(prefix, prefixlen),
	527	IN6_ADDR_PREFIX_TO_STRING(&opt->prefix.address, opt->prefix.prefixlen));
	528	}
	529
	530	return ndisc_option_set_prefix(
	531	&ra->options,
	532	flags,
	533	prefixlen,
	534	prefix,
	535	valid_lifetime_usec,
	536	preferred_lifetime_usec,
	537	valid_until,
	538	preferred_until);
	539	}
	540
	541	void sd_radv_remove_prefix(
	542	sd_radv *ra,
	543	const struct in6_addr *prefix,
	544	uint8_t prefixlen) {
	545
	546	if (!ra \|\| !prefix)
	547	return;
	548
	549	ndisc_option_remove(ra->options,
	550	&(sd_ndisc_option) {
	551	.type = SD_NDISC_OPTION_PREFIX_INFORMATION,
	552	.prefix.prefixlen = prefixlen,
	553	.prefix.address = *prefix,
	554	});
	555	}
	556
	557	int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
	558	assert_return(ra, -EINVAL);
	559	assert_return(mtu >= IPV6_MIN_MTU, -EINVAL);
	560
	561	return ndisc_option_set_mtu(&ra->options, mtu);
	562	}
	563
	564	void sd_radv_unset_mtu(sd_radv *ra) {
	565	if (!ra)
	566	return;
	567
	568	ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_MTU);
	569	}
	570
	571	int sd_radv_set_home_agent(sd_radv *ra, uint16_t preference, uint64_t lifetime_usec, uint64_t valid_until) {
	572	assert_return(ra, -EINVAL);
	573
	574	ra->flags \|= ND_RA_FLAG_HOME_AGENT;
	575	return ndisc_option_set_home_agent(&ra->options, preference, lifetime_usec, valid_until);
	576	}
	577
	578	void sd_radv_unset_home_agent(sd_radv *ra) {
	579	if (!ra)
	580	return;
	581
	582	ra->flags &= ~ND_RA_FLAG_HOME_AGENT;
	583	ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_HOME_AGENT);
	584	}
	585
	586	int sd_radv_add_route(
	587	sd_radv *ra,
	588	const struct in6_addr *prefix,
	589	uint8_t prefixlen,
	590	uint8_t preference,
	591	uint64_t lifetime_usec,
	592	uint64_t valid_until) {
	593
	594	assert_return(ra, -EINVAL);
	595	assert_return(prefix, -EINVAL);
	596
	597	return ndisc_option_set_route(
	598	&ra->options,
	599	preference,
	600	prefixlen,
	601	prefix,
	602	lifetime_usec,
	603	valid_until);
	604	}
	605
	606	void sd_radv_remove_route(
	607	sd_radv *ra,
	608	const struct in6_addr *prefix,
	609	uint8_t prefixlen) {
	610
	611	if (!ra \|\| !prefix)
	612	return;
	613
	614	ndisc_option_remove(ra->options,
	615	&(sd_ndisc_option) {
	616	.type = SD_NDISC_OPTION_ROUTE_INFORMATION,
	617	.route.prefixlen = prefixlen,
	618	.route.address = *prefix,
	619	});
	620	}
	621
	622	int sd_radv_add_rdnss(
	623	sd_radv *ra,
	624	size_t n_dns,
	625	const struct in6_addr *dns,
	626	uint64_t lifetime_usec,
	627	uint64_t valid_until) {
	628
	629	assert_return(ra, -EINVAL);
	630	assert_return(dns, -EINVAL);
	631
	632	return ndisc_option_set_rdnss(
	633	&ra->options,
	634	n_dns,
	635	dns,
	636	lifetime_usec,
	637	valid_until);
	638	}
	639
	640	void sd_radv_clear_rdnss(sd_radv *ra) {
	641	if (!ra)
	642	return;
	643
	644	sd_ndisc_option *opt;
	645	SET_FOREACH(opt, ra->options)
	646	if (opt->type == SD_NDISC_OPTION_RDNSS)
	647	ndisc_option_remove(ra->options, opt);
	648	}
	649
	650	int sd_radv_add_dnssl(
	651	sd_radv *ra,
	652	char * const *domains,
	653	uint64_t lifetime_usec,
	654	uint64_t valid_until) {
	655
	656	assert_return(ra, -EINVAL);
	657
	658	return ndisc_option_set_dnssl(
	659	&ra->options,
	660	domains,
	661	lifetime_usec,
	662	valid_until);
	663	}
	664
	665	void sd_radv_clear_dnssl(sd_radv *ra) {
	666	if (!ra)
	667	return;
	668
	669	sd_ndisc_option *opt;
	670	SET_FOREACH(opt, ra->options)
	671	if (opt->type == SD_NDISC_OPTION_DNSSL)
	672	ndisc_option_remove(ra->options, opt);
	673	}
	674
	675	int sd_radv_set_captive_portal(sd_radv ra, const char portal) {
	676	assert_return(ra, -EINVAL);
	677	assert_return(portal, -EINVAL);
	678
	679	return ndisc_option_set_captive_portal(&ra->options, portal);
	680	}
	681
	682	void sd_radv_unset_captive_portal(sd_radv *ra) {
	683	if (!ra)
	684	return;
	685
	686	ndisc_option_remove_by_type(ra->options, SD_NDISC_OPTION_CAPTIVE_PORTAL);
	687	}
	688
	689	int sd_radv_add_prefix64(
	690	sd_radv *ra,
	691	const struct in6_addr *prefix,
	692	uint8_t prefixlen,
	693	uint64_t lifetime_usec,
	694	uint64_t valid_until) {
	695
	696	assert_return(ra, -EINVAL);
	697	assert_return(prefix, -EINVAL);
	698
	699	return ndisc_option_set_prefix64(
	700	&ra->options,
	701	prefixlen,
	702	prefix,
	703	lifetime_usec,
	704	valid_until);
	705	}
	706
	707	void sd_radv_remove_prefix64(
	708	sd_radv *ra,
	709	const struct in6_addr *prefix,
	710	uint8_t prefixlen) {
	711
	712	if (!ra \|\| !prefix)
	713	return;
	714
	715	ndisc_option_remove(ra->options,
	716	&(sd_ndisc_option) {
	717	.type = SD_NDISC_OPTION_PREF64,
	718	.prefix64.prefixlen = prefixlen,
	719	.prefix64.prefix = *prefix,
	720	});
	721	}