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

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

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

#include "sd-radv.h"

#include "macro.h"
#include "alloc-util.h"
#include "dns-domain.h"
#include "ether-addr-util.h"
#include "event-util.h"
#include "fd-util.h"
#include "icmp6-util.h"
#include "in-addr-util.h"
#include "radv-internal.h"
#include "socket-util.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
#include "random-util.h"

_public_ 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 = -1,
        };

        *ret = TAKE_PTR(ra);

        return 0;
}

_public_ 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;
}

_public_ int sd_radv_detach_event(sd_radv *ra) {

        assert_return(ra, -EINVAL);

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

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

        return ra->event;
}

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

        (void) event_source_disable(ra->timeout_event_source);

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

        ra->ra_sent = 0;
}

static sd_radv *radv_free(sd_radv *ra) {
        assert(ra);

        while (ra->prefixes) {
                sd_radv_prefix *p = ra->prefixes;

                LIST_REMOVE(prefix, ra->prefixes, p);
                sd_radv_prefix_unref(p);
        }

        free(ra->rdnss);
        free(ra->dnssl);

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

        radv_reset(ra);

        sd_radv_detach_event(ra);

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

        return mfree(ra);
}

DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);

static int radv_send(sd_radv *ra, const struct in6_addr *dst, uint32_t router_lifetime) {
        sd_radv_prefix *p;
        struct sockaddr_in6 dst_addr = {
                .sin6_family = AF_INET6,
                .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
        };
        struct nd_router_advert adv = {};
        struct {
                struct nd_opt_hdr opthdr;
                struct ether_addr slladdr;
        } _packed_ opt_mac = {
                .opthdr = {
                        .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
                        .nd_opt_len = (sizeof(struct nd_opt_hdr) +
                                       sizeof(struct ether_addr) - 1) /8 + 1,
                },
        };
        struct nd_opt_mtu opt_mtu =  {
                .nd_opt_mtu_type = ND_OPT_MTU,
                .nd_opt_mtu_len = 1,
        };
        /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
           and DNSSL */
        struct iovec iov[5 + ra->n_prefixes];
        struct msghdr msg = {
                .msg_name = &dst_addr,
                .msg_namelen = sizeof(dst_addr),
                .msg_iov = iov,
        };
        usec_t time_now;
        int r;

        assert(ra);

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

        if (dst && !IN6_IS_ADDR_UNSPECIFIED(dst))
                dst_addr.sin6_addr = *dst;

        adv.nd_ra_type = ND_ROUTER_ADVERT;
        adv.nd_ra_curhoplimit = ra->hop_limit;
        adv.nd_ra_flags_reserved = ra->flags;
        adv.nd_ra_router_lifetime = htobe16(router_lifetime);
        iov[msg.msg_iovlen].iov_base = &adv;
        iov[msg.msg_iovlen].iov_len = sizeof(adv);
        msg.msg_iovlen++;

        /* MAC address is optional, either because the link does not use L2
           addresses or load sharing is desired. See RFC 4861, Section 4.2 */
        if (!ether_addr_is_null(&ra->mac_addr)) {
                opt_mac.slladdr = ra->mac_addr;
                iov[msg.msg_iovlen].iov_base = &opt_mac;
                iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
                msg.msg_iovlen++;
        }

        if (ra->mtu) {
                opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
                iov[msg.msg_iovlen].iov_base = &opt_mtu;
                iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
                msg.msg_iovlen++;
        }

        LIST_FOREACH(prefix, p, ra->prefixes) {
                if (p->valid_until) {

                        if (time_now > p->valid_until)
                                p->opt.valid_lifetime = 0;
                        else
                                p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);

                        if (time_now > p->preferred_until)
                                p->opt.preferred_lifetime = 0;
                        else
                                p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
                }
                iov[msg.msg_iovlen].iov_base = &p->opt;
                iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
                msg.msg_iovlen++;
        }

        if (ra->rdnss) {
                iov[msg.msg_iovlen].iov_base = ra->rdnss;
                iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
                msg.msg_iovlen++;
        }

        if (ra->dnssl) {
                iov[msg.msg_iovlen].iov_base = ra->dnssl;
                iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
                msg.msg_iovlen++;
        }

        if (sendmsg(ra->fd, &msg, 0) < 0)
                return -errno;

        return 0;
}

static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
        sd_radv *ra = userdata;
        _cleanup_free_ char *addr = NULL;
        struct in6_addr src;
        triple_timestamp timestamp;
        int r;
        ssize_t buflen;
        _cleanup_free_ char *buf = NULL;

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

        buflen = next_datagram_size_fd(fd);

        if ((unsigned) buflen < sizeof(struct nd_router_solicit))
                return log_radv("Too short packet received");

        buf = new0(char, buflen);
        if (!buf)
                return 0;

        r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
        if (r < 0) {
                switch (r) {
                case -EADDRNOTAVAIL:
                        (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
                        log_radv("Received RS from non-link-local address %s. Ignoring", addr);
                        break;

                case -EMULTIHOP:
                        log_radv("Received RS with invalid hop limit. Ignoring.");
                        break;

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

                case -EAGAIN: /* ignore spurious wakeups */
                        break;

                default:
                        log_radv_errno(r, "Unexpected error receiving from ICMPv6 socket: %m");
                        break;
                }

                return 0;
        }

        (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);

        r = radv_send(ra, &src, ra->lifetime);
        if (r < 0)
                log_radv_errno(r, "Unable to send solicited Router Advertisement to %s: %m", addr);
        else
                log_radv("Sent solicited Router Advertisement to %s", addr);

        return 0;
}

static usec_t radv_compute_timeout(usec_t min, usec_t max) {
        assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);

        return min + (random_u32() % (max - min));
}

static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
        int r;
        sd_radv *ra = userdata;
        usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
        usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
        usec_t time_now, timeout;
        char time_string[FORMAT_TIMESPAN_MAX];

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

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

        r = radv_send(ra, NULL, ra->lifetime);
        if (r < 0)
                log_radv_errno(r, "Unable to send Router Advertisement: %m");

        /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
        if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
                max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
                min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
        }

        timeout = radv_compute_timeout(min_timeout, max_timeout);

        log_radv("Next Router Advertisement in %s",
                 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
                                 timeout, USEC_PER_SEC));

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

        ra->ra_sent++;

        return 0;

fail:
        sd_radv_stop(ra);

        return 0;
}

_public_ int sd_radv_stop(sd_radv *ra) {
        int r;

        assert_return(ra, -EINVAL);

        if (ra->state == SD_RADV_STATE_IDLE)
                return 0;

        log_radv("Stopping IPv6 Router Advertisement daemon");

        /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
           with zero lifetime  */
        r = radv_send(ra, NULL, 0);
        if (r < 0)
                log_radv_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");

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

        return 0;
}

_public_ int sd_radv_start(sd_radv *ra) {
        int r = 0;

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

        if (ra->state != SD_RADV_STATE_IDLE)
                return 0;

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

        r = icmp6_bind_router_advertisement(ra->ifindex);
        if (r < 0)
                goto fail;

        ra->fd = r;

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

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

        (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");

        ra->state = SD_RADV_STATE_ADVERTISING;

        log_radv("Started IPv6 Router Advertisement daemon");

        return 0;

 fail:
        radv_reset(ra);

        return r;
}

_public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
        assert_return(ra, -EINVAL);
        assert_return(ifindex >= -1, -EINVAL);

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

        ra->ifindex = ifindex;

        return 0;
}

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

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

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

        return 0;
}

_public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
        assert_return(ra, -EINVAL);
        assert_return(mtu >= 1280, -EINVAL);

        ra->mtu = mtu;

        return 0;
}

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

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

        ra->hop_limit = hop_limit;

        return 0;
}

_public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
        assert_return(ra, -EINVAL);

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

        /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
           preference value MUST be set to (00) by the sender..." */
        if (router_lifetime == 0 &&
            (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
                return -ETIME;

        ra->lifetime = router_lifetime;

        return 0;
}

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

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

        SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);

        return 0;
}

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

        if (ra->state != SD_RADV_STATE_IDLE)
                return -EBUSY;

        SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);

        return 0;
}

_public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
        int r = 0;

        assert_return(ra, -EINVAL);
        assert_return(IN_SET(preference,
                             SD_NDISC_PREFERENCE_LOW,
                             SD_NDISC_PREFERENCE_MEDIUM,
                             SD_NDISC_PREFERENCE_HIGH), -EINVAL);

        ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);

        return r;
}

_public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, bool dynamic) {
        sd_radv_prefix *cur;
        int r;
        _cleanup_free_ char *addr_p = NULL;
        char time_string_preferred[FORMAT_TIMESPAN_MAX];
        char time_string_valid[FORMAT_TIMESPAN_MAX];
        usec_t time_now, valid, preferred, valid_until, preferred_until;

        assert_return(ra, -EINVAL);

        if (!p)
                return -EINVAL;

        LIST_FOREACH(prefix, cur, ra->prefixes) {

                r = in_addr_prefix_intersect(AF_INET6,
                                             (union in_addr_union*) &cur->opt.in6_addr,
                                             cur->opt.prefixlen,
                                             (union in_addr_union*) &p->opt.in6_addr,
                                             p->opt.prefixlen);
                if (r > 0) {
                        _cleanup_free_ char *addr_cur = NULL;

                        (void) in_addr_to_string(AF_INET6,
                                                 (union in_addr_union*) &p->opt.in6_addr,
                                                 &addr_p);

                        if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
                                goto update;

                        (void) in_addr_to_string(AF_INET6,
                                                 (union in_addr_union*) &cur->opt.in6_addr,
                                                 &addr_cur);
                        log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
                                 addr_cur, cur->opt.prefixlen,
                                 addr_p, p->opt.prefixlen);

                        return -EEXIST;
                }
        }

        p = sd_radv_prefix_ref(p);

        LIST_APPEND(prefix, ra->prefixes, p);

        ra->n_prefixes++;

        (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);

        if (!dynamic) {
                log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
                return 0;
        }

        cur = p;

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

        valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
        valid_until = usec_add(valid, time_now);
        if (valid_until == USEC_INFINITY)
                return -EOVERFLOW;

        preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
        preferred_until = usec_add(preferred, time_now);
        if (preferred_until == USEC_INFINITY)
                return -EOVERFLOW;

        cur->valid_until = valid_until;
        cur->preferred_until = preferred_until;

        log_radv("%s prefix %s/%u preferred %s valid %s",
                 cur? "Updated": "Added",
                 addr_p, p->opt.prefixlen,
                 format_timespan(time_string_preferred, FORMAT_TIMESPAN_MAX,
                                 preferred, USEC_PER_SEC),
                 format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX,
                                 valid, USEC_PER_SEC));

        return 0;
}

_public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
                                               const struct in6_addr *prefix,
                                               unsigned char prefixlen) {
        sd_radv_prefix *cur, *next;

        assert_return(ra, NULL);
        assert_return(prefix, NULL);

        LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
                if (prefixlen != cur->opt.prefixlen)
                        continue;

                if (!in_addr_equal(AF_INET6,
                                   (union in_addr_union *)prefix,
                                   (union in_addr_union *)&cur->opt.in6_addr))
                        continue;

                LIST_REMOVE(prefix, ra->prefixes, cur);
                ra->n_prefixes--;

                break;
        }

        return cur;
}

_public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
                               const struct in6_addr *dns, size_t n_dns) {
        _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
        size_t len;

        assert_return(ra, -EINVAL);
        assert_return(n_dns < 128, -EINVAL);

        if (!dns || n_dns == 0) {
                ra->rdnss = mfree(ra->rdnss);
                ra->n_rdnss = 0;

                return 0;
        }

        len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;

        opt_rdnss = malloc0(len);
        if (!opt_rdnss)
                return -ENOMEM;

        opt_rdnss->type = SD_RADV_OPT_RDNSS;
        opt_rdnss->length = len / 8;
        opt_rdnss->lifetime = htobe32(lifetime);

        memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));

        free_and_replace(ra->rdnss, opt_rdnss);

        ra->n_rdnss = n_dns;

        return 0;
}

_public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
                               char **search_list) {
        _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
        size_t len = 0;
        char **s;
        uint8_t *p;

        assert_return(ra, -EINVAL);

        if (strv_isempty(search_list)) {
                ra->dnssl = mfree(ra->dnssl);
                return 0;
        }

        STRV_FOREACH(s, search_list)
                len += strlen(*s) + 2;

        len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;

        opt_dnssl = malloc0(len);
        if (!opt_dnssl)
                return -ENOMEM;

        opt_dnssl->type = SD_RADV_OPT_DNSSL;
        opt_dnssl->length = len / 8;
        opt_dnssl->lifetime = htobe32(lifetime);

        p = (uint8_t *)(opt_dnssl + 1);
        len -= sizeof(struct sd_radv_opt_dns);

        STRV_FOREACH(s, search_list) {
                int r;

                r = dns_name_to_wire_format(*s, p, len, false);
                if (r < 0)
                        return r;

                if (len < (size_t)r)
                        return -ENOBUFS;

                p += r;
                len -= r;
        }

        free_and_replace(ra->dnssl, opt_dnssl);

        return 0;
}

_public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
        _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;

        assert_return(ret, -EINVAL);

        p = new0(sd_radv_prefix, 1);
        if (!p)
                return -ENOMEM;

        p->n_ref = 1;

        p->opt.type = ND_OPT_PREFIX_INFORMATION;
        p->opt.length = (sizeof(p->opt) - 1) /8 + 1;

        p->opt.prefixlen = 64;

        /* RFC 4861, Section 6.2.1 */
        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
        p->opt.preferred_lifetime = htobe32(604800);
        p->opt.valid_lifetime = htobe32(2592000);

        LIST_INIT(prefix, p);

        *ret = TAKE_PTR(p);

        return 0;
}

DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);

_public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, const struct in6_addr *in6_addr,
                                       unsigned char prefixlen) {
        assert_return(p, -EINVAL);
        assert_return(in6_addr, -EINVAL);

        if (prefixlen < 3 || prefixlen > 128)
                return -EINVAL;

        if (prefixlen > 64)
                /* unusual but allowed, log it */
                log_radv("Unusual prefix length %d greater than 64", prefixlen);

        p->opt.in6_addr = *in6_addr;
        p->opt.prefixlen = prefixlen;

        return 0;
}

_public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
        assert_return(p, -EINVAL);

        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);

        return 0;
}

_public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
                                                          int address_autoconfiguration) {
        assert_return(p, -EINVAL);

        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);

        return 0;
}

_public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
                                               uint32_t valid_lifetime) {
        assert_return(p, -EINVAL);

        p->opt.valid_lifetime = htobe32(valid_lifetime);

        return 0;
}

_public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
                                                   uint32_t preferred_lifetime) {
        assert_return(p, -EINVAL);

        p->opt.preferred_lifetime = htobe32(preferred_lifetime);

        return 0;
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
04473969	2	/***
810adae9	3	Copyright © 2017 Intel Corporation. All rights reserved.
04473969 PF	4	***/
	5
	6	#include <netinet/icmp6.h>
	7	#include <netinet/in.h>
204f99d2	8	#include <arpa/inet.h>
04473969 PF	9
	10	#include "sd-radv.h"
	11
204f99d2	12	#include "macro.h"
04473969	13	#include "alloc-util.h"
e965d6ab	14	#include "dns-domain.h"
ae25915d	15	#include "ether-addr-util.h"
807a8ede	16	#include "event-util.h"
04473969 PF	17	#include "fd-util.h"
	18	#include "icmp6-util.h"
	19	#include "in-addr-util.h"
	20	#include "radv-internal.h"
	21	#include "socket-util.h"
	22	#include "string-util.h"
e965d6ab	23	#include "strv.h"
04473969	24	#include "util.h"
204fb681	25	#include "random-util.h"
04473969	26
204f99d2 PF	27	_public_ int sd_radv_new(sd_radv **ret) {
	28	_cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
	29
	30	assert_return(ret, -EINVAL);
	31
78f9d24f	32	ra = new(sd_radv, 1);
204f99d2 PF	33	if (!ra)
	34	return -ENOMEM;
	35
78f9d24f YW	36	*ra = (sd_radv) {
	37	.n_ref = 1,
	38	.fd = -1,
	39	};
204f99d2	40
1cc6c93a	41	*ret = TAKE_PTR(ra);
204f99d2 PF	42
	43	return 0;
	44	}
	45
	46	_public_ int sd_radv_attach_event(sd_radv ra, sd_event event, int64_t priority) {
	47	int r;
	48
	49	assert_return(ra, -EINVAL);
	50	assert_return(!ra->event, -EBUSY);
	51
	52	if (event)
	53	ra->event = sd_event_ref(event);
	54	else {
	55	r = sd_event_default(&ra->event);
	56	if (r < 0)
	57	return 0;
	58	}
	59
	60	ra->event_priority = priority;
	61
	62	return 0;
	63	}
	64
	65	_public_ int sd_radv_detach_event(sd_radv *ra) {
	66
	67	assert_return(ra, -EINVAL);
	68
	69	ra->event = sd_event_unref(ra->event);
	70	return 0;
	71	}
	72
	73	_public_ sd_event sd_radv_get_event(sd_radv ra) {
	74	assert_return(ra, NULL);
	75
	76	return ra->event;
	77	}
	78
204fb681	79	static void radv_reset(sd_radv *ra) {
c4b6dda0	80	assert(ra);
204fb681	81
807a8ede	82	(void) event_source_disable(ra->timeout_event_source);
204fb681	83
88d5a3db PF	84	ra->recv_event_source =
	85	sd_event_source_unref(ra->recv_event_source);
	86
204fb681 PF	87	ra->ra_sent = 0;
	88	}
	89
8301aa0b YW	90	static sd_radv radv_free(sd_radv ra) {
8301aa0b YW	91	assert(ra);
204f99d2 PF	92
	93	while (ra->prefixes) {
	94	sd_radv_prefix *p = ra->prefixes;
	95
	96	LIST_REMOVE(prefix, ra->prefixes, p);
	97	sd_radv_prefix_unref(p);
	98	}
	99
e9c6da38	100	free(ra->rdnss);
f9aa5417	101	free(ra->dnssl);
e9c6da38	102
807a8ede YW	103	ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
807a8ede YW	104
204fb681 PF	105	radv_reset(ra);
204fb681 PF	106
204f99d2	107	sd_radv_detach_event(ra);
c4b6dda0 LP	108
	109	ra->fd = safe_close(ra->fd);
	110
204f99d2 PF	111	return mfree(ra);
	112	}
	113
8301aa0b YW	114	DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
8301aa0b YW	115
83ef9d14	116	static int radv_send(sd_radv ra, const struct in6_addr dst, uint32_t router_lifetime) {
77baf5ae PF	117	sd_radv_prefix *p;
	118	struct sockaddr_in6 dst_addr = {
	119	.sin6_family = AF_INET6,
	120	.sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
	121	};
	122	struct nd_router_advert adv = {};
	123	struct {
	124	struct nd_opt_hdr opthdr;
	125	struct ether_addr slladdr;
	126	} _packed_ opt_mac = {
	127	.opthdr = {
	128	.nd_opt_type = ND_OPT_SOURCE_LINKADDR,
	129	.nd_opt_len = (sizeof(struct nd_opt_hdr) +
	130	sizeof(struct ether_addr) - 1) /8 + 1,
	131	},
	132	};
	133	struct nd_opt_mtu opt_mtu = {
	134	.nd_opt_mtu_type = ND_OPT_MTU,
	135	.nd_opt_mtu_len = 1,
	136	};
6852c0f6 PF	137	/* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
	138	and DNSSL */
	139	struct iovec iov[5 + ra->n_prefixes];
77baf5ae PF	140	struct msghdr msg = {
	141	.msg_name = &dst_addr,
	142	.msg_namelen = sizeof(dst_addr),
	143	.msg_iov = iov,
	144	};
d601b566 PF	145	usec_t time_now;
	146	int r;
	147
dc0ec5e2 LP	148	assert(ra);
dc0ec5e2 LP	149
d601b566 PF	150	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	151	if (r < 0)
	152	return r;
77baf5ae	153
dc0ec5e2	154	if (dst && !IN6_IS_ADDR_UNSPECIFIED(dst))
77baf5ae	155	dst_addr.sin6_addr = *dst;
88d5a3db	156
77baf5ae PF	157	adv.nd_ra_type = ND_ROUTER_ADVERT;
	158	adv.nd_ra_curhoplimit = ra->hop_limit;
	159	adv.nd_ra_flags_reserved = ra->flags;
	160	adv.nd_ra_router_lifetime = htobe16(router_lifetime);
	161	iov[msg.msg_iovlen].iov_base = &adv;
	162	iov[msg.msg_iovlen].iov_len = sizeof(adv);
	163	msg.msg_iovlen++;
	164
	165	/* MAC address is optional, either because the link does not use L2
	166	addresses or load sharing is desired. See RFC 4861, Section 4.2 */
ae25915d	167	if (!ether_addr_is_null(&ra->mac_addr)) {
77baf5ae PF	168	opt_mac.slladdr = ra->mac_addr;
	169	iov[msg.msg_iovlen].iov_base = &opt_mac;
	170	iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
	171	msg.msg_iovlen++;
	172	}
	173
	174	if (ra->mtu) {
	175	opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
	176	iov[msg.msg_iovlen].iov_base = &opt_mtu;
	177	iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
	178	msg.msg_iovlen++;
	179	}
	180
	181	LIST_FOREACH(prefix, p, ra->prefixes) {
d601b566 PF	182	if (p->valid_until) {
	183
	184	if (time_now > p->valid_until)
	185	p->opt.valid_lifetime = 0;
	186	else
	187	p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);
	188
	189	if (time_now > p->preferred_until)
	190	p->opt.preferred_lifetime = 0;
	191	else
	192	p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
	193	}
77baf5ae PF	194	iov[msg.msg_iovlen].iov_base = &p->opt;
	195	iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
	196	msg.msg_iovlen++;
	197	}
	198
e9c6da38 PF	199	if (ra->rdnss) {
	200	iov[msg.msg_iovlen].iov_base = ra->rdnss;
	201	iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
	202	msg.msg_iovlen++;
	203	}
	204
e965d6ab PF	205	if (ra->dnssl) {
	206	iov[msg.msg_iovlen].iov_base = ra->dnssl;
	207	iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
	208	msg.msg_iovlen++;
	209	}
	210
77baf5ae PF	211	if (sendmsg(ra->fd, &msg, 0) < 0)
77baf5ae PF	212	return -errno;
204fb681	213
77baf5ae	214	return 0;
204fb681 PF	215	}
204fb681 PF	216
88d5a3db PF	217	static int radv_recv(sd_event_source s, int fd, uint32_t revents, void userdata) {
	218	sd_radv *ra = userdata;
	219	_cleanup_free_ char *addr = NULL;
	220	struct in6_addr src;
	221	triple_timestamp timestamp;
	222	int r;
	223	ssize_t buflen;
	224	_cleanup_free_ char *buf = NULL;
	225
	226	assert(s);
	227	assert(ra);
	228	assert(ra->event);
	229
	230	buflen = next_datagram_size_fd(fd);
	231
	232	if ((unsigned) buflen < sizeof(struct nd_router_solicit))
	233	return log_radv("Too short packet received");
	234
	235	buf = new0(char, buflen);
	236	if (!buf)
	237	return 0;
	238
	239	r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
	240	if (r < 0) {
	241	switch (r) {
	242	case -EADDRNOTAVAIL:
	243	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
	244	log_radv("Received RS from non-link-local address %s. Ignoring", addr);
	245	break;
	246
	247	case -EMULTIHOP:
	248	log_radv("Received RS with invalid hop limit. Ignoring.");
	249	break;
	250
	251	case -EPFNOSUPPORT:
	252	log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
	253	break;
	254
8eb41f4c LP	255	case -EAGAIN: /* ignore spurious wakeups */
	256	break;
	257
88d5a3db	258	default:
8eb41f4c	259	log_radv_errno(r, "Unexpected error receiving from ICMPv6 socket: %m");
88d5a3db PF	260	break;
	261	}
	262
	263	return 0;
	264	}
	265
	266	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
	267
	268	r = radv_send(ra, &src, ra->lifetime);
	269	if (r < 0)
fdc2afc1	270	log_radv_errno(r, "Unable to send solicited Router Advertisement to %s: %m", addr);
88d5a3db PF	271	else
	272	log_radv("Sent solicited Router Advertisement to %s", addr);
	273
	274	return 0;
	275	}
	276
204fb681 PF	277	static usec_t radv_compute_timeout(usec_t min, usec_t max) {
	278	assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
	279
	280	return min + (random_u32() % (max - min));
	281	}
	282
	283	static int radv_timeout(sd_event_source s, uint64_t usec, void userdata) {
	284	int r;
	285	sd_radv *ra = userdata;
	286	usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
	287	usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
	288	usec_t time_now, timeout;
	289	char time_string[FORMAT_TIMESPAN_MAX];
	290
	291	assert(s);
	292	assert(ra);
	293	assert(ra->event);
	294
204fb681 PF	295	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	296	if (r < 0)
	297	goto fail;
	298
	299	r = radv_send(ra, NULL, ra->lifetime);
	300	if (r < 0)
fdc2afc1	301	log_radv_errno(r, "Unable to send Router Advertisement: %m");
204fb681 PF	302
	303	/* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
	304	if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
	305	max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
	306	min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
	307	}
	308
	309	timeout = radv_compute_timeout(min_timeout, max_timeout);
	310
	311	log_radv("Next Router Advertisement in %s",
	312	format_timespan(time_string, FORMAT_TIMESPAN_MAX,
	313	timeout, USEC_PER_SEC));
	314
807a8ede YW	315	r = event_reset_time(ra->event, &ra->timeout_event_source,
	316	clock_boottime_or_monotonic(),
	317	time_now + timeout, MSEC_PER_SEC,
	318	radv_timeout, ra,
	319	ra->event_priority, "radv-timeout", true);
204fb681 PF	320	if (r < 0)
	321	goto fail;
	322
	323	ra->ra_sent++;
	324
807a8ede YW	325	return 0;
807a8ede YW	326
204fb681	327	fail:
807a8ede	328	sd_radv_stop(ra);
204fb681 PF	329
	330	return 0;
	331	}
	332
204f99d2	333	_public_ int sd_radv_stop(sd_radv *ra) {
204fb681 PF	334	int r;
204fb681 PF	335
204f99d2 PF	336	assert_return(ra, -EINVAL);
204f99d2 PF	337
6f8a8b84 SS	338	if (ra->state == SD_RADV_STATE_IDLE)
	339	return 0;
	340
204f99d2 PF	341	log_radv("Stopping IPv6 Router Advertisement daemon");
204f99d2 PF	342
204fb681 PF	343	/* RFC 4861, Section 6.2.5, send at least one Router Advertisement
	344	with zero lifetime */
	345	r = radv_send(ra, NULL, 0);
	346	if (r < 0)
fdc2afc1	347	log_radv_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
204fb681 PF	348
204fb681 PF	349	radv_reset(ra);
77baf5ae	350	ra->fd = safe_close(ra->fd);
204f99d2 PF	351	ra->state = SD_RADV_STATE_IDLE;
	352
	353	return 0;
	354	}
	355
	356	_public_ int sd_radv_start(sd_radv *ra) {
204fb681 PF	357	int r = 0;
204fb681 PF	358
204f99d2 PF	359	assert_return(ra, -EINVAL);
	360	assert_return(ra->event, -EINVAL);
	361	assert_return(ra->ifindex > 0, -EINVAL);
	362
	363	if (ra->state != SD_RADV_STATE_IDLE)
	364	return 0;
	365
807a8ede YW	366	r = event_reset_time(ra->event, &ra->timeout_event_source,
	367	clock_boottime_or_monotonic(),
	368	0, 0,
	369	radv_timeout, ra,
	370	ra->event_priority, "radv-timeout", true);
204fb681 PF	371	if (r < 0)
	372	goto fail;
	373
77baf5ae PF	374	r = icmp6_bind_router_advertisement(ra->ifindex);
	375	if (r < 0)
	376	goto fail;
	377
	378	ra->fd = r;
88d5a3db PF	379
	380	r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
	381	if (r < 0)
	382	goto fail;
	383
	384	r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
	385	if (r < 0)
	386	goto fail;
	387
	388	(void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
77baf5ae	389
204f99d2 PF	390	ra->state = SD_RADV_STATE_ADVERTISING;
	391
	392	log_radv("Started IPv6 Router Advertisement daemon");
	393
	394	return 0;
204fb681 PF	395
	396	fail:
	397	radv_reset(ra);
	398
	399	return r;
204f99d2 PF	400	}
	401
	402	_public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
	403	assert_return(ra, -EINVAL);
	404	assert_return(ifindex >= -1, -EINVAL);
	405
	406	if (ra->state != SD_RADV_STATE_IDLE)
	407	return -EBUSY;
	408
	409	ra->ifindex = ifindex;
	410
	411	return 0;
	412	}
	413
	414	_public_ int sd_radv_set_mac(sd_radv ra, const struct ether_addr mac_addr) {
	415	assert_return(ra, -EINVAL);
	416
	417	if (ra->state != SD_RADV_STATE_IDLE)
	418	return -EBUSY;
	419
	420	if (mac_addr)
	421	ra->mac_addr = *mac_addr;
	422	else
	423	zero(ra->mac_addr);
	424
	425	return 0;
	426	}
	427
	428	_public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
	429	assert_return(ra, -EINVAL);
	430	assert_return(mtu >= 1280, -EINVAL);
	431
204f99d2 PF	432	ra->mtu = mtu;
	433
	434	return 0;
	435	}
	436
	437	_public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
	438	assert_return(ra, -EINVAL);
	439
	440	if (ra->state != SD_RADV_STATE_IDLE)
	441	return -EBUSY;
	442
	443	ra->hop_limit = hop_limit;
	444
	445	return 0;
	446	}
	447
	448	_public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
	449	assert_return(ra, -EINVAL);
	450
	451	if (ra->state != SD_RADV_STATE_IDLE)
	452	return -EBUSY;
	453
	454	/* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
	455	preference value MUST be set to (00) by the sender..." */
	456	if (router_lifetime == 0 &&
	457	(ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
	458	return -ETIME;
	459
	460	ra->lifetime = router_lifetime;
	461
	462	return 0;
	463	}
	464
	465	_public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
	466	assert_return(ra, -EINVAL);
	467
	468	if (ra->state != SD_RADV_STATE_IDLE)
	469	return -EBUSY;
	470
	471	SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
	472
	473	return 0;
	474	}
	475
	476	_public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
	477	assert_return(ra, -EINVAL);
	478
	479	if (ra->state != SD_RADV_STATE_IDLE)
	480	return -EBUSY;
	481
	482	SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
	483
	484	return 0;
	485	}
	486
	487	_public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
	488	int r = 0;
	489
	490	assert_return(ra, -EINVAL);
	491	assert_return(IN_SET(preference,
	492	SD_NDISC_PREFERENCE_LOW,
	493	SD_NDISC_PREFERENCE_MEDIUM,
	494	SD_NDISC_PREFERENCE_HIGH), -EINVAL);
	495
496	ra->flags = (ra->flags & ~(0x3 << 3)) \| (preference << 3);
497
498	return r;
499	}
500
d601b566	501	_public_ int sd_radv_add_prefix(sd_radv ra, sd_radv_prefix p, bool dynamic) {
204f99d2	502	sd_radv_prefix *cur;
d601b566	503	int r;
204f99d2	504	_cleanup_free_ char *addr_p = NULL;
d601b566 PF	505	char time_string_preferred[FORMAT_TIMESPAN_MAX];
	506	char time_string_valid[FORMAT_TIMESPAN_MAX];
	507	usec_t time_now, valid, preferred, valid_until, preferred_until;
204f99d2 PF	508
	509	assert_return(ra, -EINVAL);
	510
	511	if (!p)
	512	return -EINVAL;
	513
	514	LIST_FOREACH(prefix, cur, ra->prefixes) {
204f99d2 PF	515
	516	r = in_addr_prefix_intersect(AF_INET6,
	517	(union in_addr_union*) &cur->opt.in6_addr,
	518	cur->opt.prefixlen,
	519	(union in_addr_union*) &p->opt.in6_addr,
	520	p->opt.prefixlen);
	521	if (r > 0) {
	522	_cleanup_free_ char *addr_cur = NULL;
	523
204f99d2 PF	524	(void) in_addr_to_string(AF_INET6,
	525	(union in_addr_union*) &p->opt.in6_addr,
	526	&addr_p);
	527
d601b566 PF	528	if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
	529	goto update;
	530
	531	(void) in_addr_to_string(AF_INET6,
	532	(union in_addr_union*) &cur->opt.in6_addr,
	533	&addr_cur);
204f99d2 PF	534	log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
	535	addr_cur, cur->opt.prefixlen,
	536	addr_p, p->opt.prefixlen);
	537
	538	return -EEXIST;
	539	}
	540	}
	541
	542	p = sd_radv_prefix_ref(p);
	543
	544	LIST_APPEND(prefix, ra->prefixes, p);
	545
	546	ra->n_prefixes++;
	547
	548	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
d601b566 PF	549
	550	if (!dynamic) {
	551	log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
	552	return 0;
	553	}
	554
	555	cur = p;
	556
	557	update:
	558	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	559	if (r < 0)
	560	return r;
	561
	562	valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
	563	valid_until = usec_add(valid, time_now);
	564	if (valid_until == USEC_INFINITY)
	565	return -EOVERFLOW;
	566
	567	preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
	568	preferred_until = usec_add(preferred, time_now);
	569	if (preferred_until == USEC_INFINITY)
	570	return -EOVERFLOW;
	571
	572	cur->valid_until = valid_until;
	573	cur->preferred_until = preferred_until;
	574
	575	log_radv("%s prefix %s/%u preferred %s valid %s",
	576	cur? "Updated": "Added",
	577	addr_p, p->opt.prefixlen,
	578	format_timespan(time_string_preferred, FORMAT_TIMESPAN_MAX,
	579	preferred, USEC_PER_SEC),
	580	format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX,
	581	valid, USEC_PER_SEC));
204f99d2 PF	582
	583	return 0;
	584	}
	585
34c169c4	586	_public_ sd_radv_prefix sd_radv_remove_prefix(sd_radv ra,
f5a5706a LP	587	const struct in6_addr *prefix,
f5a5706a LP	588	unsigned char prefixlen) {
34c169c4 PF	589	sd_radv_prefix cur, next;
	590
	591	assert_return(ra, NULL);
	592	assert_return(prefix, NULL);
	593
	594	LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
	595	if (prefixlen != cur->opt.prefixlen)
	596	continue;
	597
	598	if (!in_addr_equal(AF_INET6,
	599	(union in_addr_union *)prefix,
	600	(union in_addr_union *)&cur->opt.in6_addr))
	601	continue;
	602
	603	LIST_REMOVE(prefix, ra->prefixes, cur);
	604	ra->n_prefixes--;
	605
	606	break;
	607	}
	608
	609	return cur;
	610	}
	611
e9c6da38 PF	612	_public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
	613	const struct in6_addr *dns, size_t n_dns) {
	614	_cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
	615	size_t len;
	616
	617	assert_return(ra, -EINVAL);
	618	assert_return(n_dns < 128, -EINVAL);
	619
	620	if (!dns \|\| n_dns == 0) {
	621	ra->rdnss = mfree(ra->rdnss);
	622	ra->n_rdnss = 0;
	623
	624	return 0;
	625	}
	626
	627	len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
	628
	629	opt_rdnss = malloc0(len);
	630	if (!opt_rdnss)
	631	return -ENOMEM;
	632
	633	opt_rdnss->type = SD_RADV_OPT_RDNSS;
	634	opt_rdnss->length = len / 8;
	635	opt_rdnss->lifetime = htobe32(lifetime);
	636
	637	memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
	638
1cc6c93a	639	free_and_replace(ra->rdnss, opt_rdnss);
e9c6da38 PF	640
	641	ra->n_rdnss = n_dns;
	642
	643	return 0;
	644	}
	645
e965d6ab PF	646	_public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
	647	char **search_list) {
	648	_cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
	649	size_t len = 0;
	650	char **s;
	651	uint8_t *p;
	652
	653	assert_return(ra, -EINVAL);
	654
97d7974b	655	if (strv_isempty(search_list)) {
e965d6ab	656	ra->dnssl = mfree(ra->dnssl);
e965d6ab PF	657	return 0;
	658	}
	659
	660	STRV_FOREACH(s, search_list)
	661	len += strlen(*s) + 2;
	662
	663	len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
	664
	665	opt_dnssl = malloc0(len);
	666	if (!opt_dnssl)
	667	return -ENOMEM;
	668
	669	opt_dnssl->type = SD_RADV_OPT_DNSSL;
	670	opt_dnssl->length = len / 8;
	671	opt_dnssl->lifetime = htobe32(lifetime);
	672
	673	p = (uint8_t *)(opt_dnssl + 1);
	674	len -= sizeof(struct sd_radv_opt_dns);
	675
	676	STRV_FOREACH(s, search_list) {
	677	int r;
	678
	679	r = dns_name_to_wire_format(*s, p, len, false);
	680	if (r < 0)
	681	return r;
	682
	683	if (len < (size_t)r)
	684	return -ENOBUFS;
	685
	686	p += r;
	687	len -= r;
	688	}
	689
1cc6c93a	690	free_and_replace(ra->dnssl, opt_dnssl);
e965d6ab PF	691
	692	return 0;
	693	}
	694
04473969 PF	695	_public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
	696	_cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
	697
	698	assert_return(ret, -EINVAL);
	699
	700	p = new0(sd_radv_prefix, 1);
	701	if (!p)
	702	return -ENOMEM;
	703
	704	p->n_ref = 1;
	705
	706	p->opt.type = ND_OPT_PREFIX_INFORMATION;
	707	p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
	708
	709	p->opt.prefixlen = 64;
	710
	711	/* RFC 4861, Section 6.2.1 */
	712	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
	713	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
	714	p->opt.preferred_lifetime = htobe32(604800);
	715	p->opt.valid_lifetime = htobe32(2592000);
	716
204f99d2 PF	717	LIST_INIT(prefix, p);
204f99d2 PF	718
1cc6c93a	719	*ret = TAKE_PTR(p);
04473969 PF	720
	721	return 0;
	722	}
	723
8301aa0b	724	DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
04473969	725
f5a5706a	726	_public_ int sd_radv_prefix_set_prefix(sd_radv_prefix p, const struct in6_addr in6_addr,
04473969 PF	727	unsigned char prefixlen) {
	728	assert_return(p, -EINVAL);
	729	assert_return(in6_addr, -EINVAL);
	730
	731	if (prefixlen < 3 \|\| prefixlen > 128)
	732	return -EINVAL;
	733
	734	if (prefixlen > 64)
	735	/* unusual but allowed, log it */
	736	log_radv("Unusual prefix length %d greater than 64", prefixlen);
	737
	738	p->opt.in6_addr = *in6_addr;
	739	p->opt.prefixlen = prefixlen;
	740
	741	return 0;
	742	}
	743
	744	_public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
	745	assert_return(p, -EINVAL);
	746
	747	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
	748
	749	return 0;
	750	}
	751
	752	_public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
	753	int address_autoconfiguration) {
	754	assert_return(p, -EINVAL);
	755
	756	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
	757
	758	return 0;
	759	}
	760
	761	_public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
	762	uint32_t valid_lifetime) {
	763	assert_return(p, -EINVAL);
	764
	765	p->opt.valid_lifetime = htobe32(valid_lifetime);
	766
	767	return 0;
	768	}
	769
	770	_public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
	771	uint32_t preferred_lifetime) {
	772	assert_return(p, -EINVAL);
	773
	774	p->opt.preferred_lifetime = htobe32(preferred_lifetime);
	775
	776	return 0;
	777	}