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

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
  This file is part of systemd.

  Copyright (C) 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 "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 = new0(sd_radv, 1);
        if (!ra)
                return -ENOMEM;

        ra->n_ref = 1;
        ra->fd = -1;

        LIST_HEAD_INIT(ra->prefixes);

        *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) {

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

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

        ra->ra_sent = 0;
}

_public_ sd_radv *sd_radv_ref(sd_radv *ra) {
        if (!ra)
                return NULL;

        assert(ra->n_ref > 0);
        ra->n_ref++;

        return ra;
}

_public_ sd_radv *sd_radv_unref(sd_radv *ra) {
        if (!ra)
                return NULL;

        assert(ra->n_ref > 0);
        ra->n_ref--;

        if (ra->n_ref > 0)
                return NULL;

        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);

        radv_reset(ra);

        sd_radv_detach_event(ra);
        return mfree(ra);
}

static int radv_send(sd_radv *ra, const struct in6_addr *dst,
                     const uint32_t router_lifetime) {
        static const struct ether_addr mac_zero = {};
        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;

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

        if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) 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 (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
                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;

                default:
                        log_radv_warning_errno(r, "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_warning_errno(r, "Unable to send solicited Router Advertisment 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);

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

        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_warning_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 = sd_event_add_time(ra->event, &ra->timeout_event_source,
                              clock_boottime_or_monotonic(),
                              time_now + timeout, MSEC_PER_SEC,
                              radv_timeout, ra);
        if (r < 0)
                goto fail;

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

        r = sd_event_source_set_description(ra->timeout_event_source,
                                            "radv-timeout");
        if (r < 0)
                goto fail;

        ra->ra_sent++;

fail:
        if (r < 0)
                sd_radv_stop(ra);

        return 0;
}

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

        assert_return(ra, -EINVAL);

        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_warning_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 = sd_event_add_time(ra->event, &ra->timeout_event_source,
                              clock_boottime_or_monotonic(), 0, 0,
                              radv_timeout, ra);
        if (r < 0)
                goto fail;

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

        (void) sd_event_source_set_description(ra->timeout_event_source,
                                               "radv-timeout");

        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,
                                               struct in6_addr *prefix,
                                               uint8_t 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 (!search_list || *search_list == NULL) {
                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;
}

_public_ sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *p) {
        if (!p)
                return NULL;

        assert(p->n_ref > 0);
        p->n_ref++;

        return p;
}

_public_ sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *p) {
        if (!p)
                return NULL;

        assert(p->n_ref > 0);
        p->n_ref--;

        if (p->n_ref > 0)
                return NULL;

        return mfree(p);
}

_public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, 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 PF	2	/***
	3	This file is part of systemd.
	4
	5	Copyright (C) 2017 Intel Corporation. All rights reserved.
04473969 PF	6	***/
	7
	8	#include <netinet/icmp6.h>
	9	#include <netinet/in.h>
204f99d2	10	#include <arpa/inet.h>
04473969 PF	11
	12	#include "sd-radv.h"
	13
204f99d2	14	#include "macro.h"
04473969	15	#include "alloc-util.h"
e965d6ab	16	#include "dns-domain.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
	32	ra = new0(sd_radv, 1);
	33	if (!ra)
	34	return -ENOMEM;
	35
	36	ra->n_ref = 1;
77baf5ae	37	ra->fd = -1;
204f99d2 PF	38
	39	LIST_HEAD_INIT(ra->prefixes);
	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 PF	79	static void radv_reset(sd_radv *ra) {
	80
	81	ra->timeout_event_source =
	82	sd_event_source_unref(ra->timeout_event_source);
	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
204f99d2 PF	90	_public_ sd_radv sd_radv_ref(sd_radv ra) {
	91	if (!ra)
	92	return NULL;
	93
	94	assert(ra->n_ref > 0);
	95	ra->n_ref++;
	96
	97	return ra;
	98	}
	99
	100	_public_ sd_radv sd_radv_unref(sd_radv ra) {
	101	if (!ra)
	102	return NULL;
	103
	104	assert(ra->n_ref > 0);
	105	ra->n_ref--;
	106
	107	if (ra->n_ref > 0)
	108	return NULL;
	109
	110	while (ra->prefixes) {
	111	sd_radv_prefix *p = ra->prefixes;
	112
	113	LIST_REMOVE(prefix, ra->prefixes, p);
	114	sd_radv_prefix_unref(p);
	115	}
	116
e9c6da38	117	free(ra->rdnss);
f9aa5417	118	free(ra->dnssl);
e9c6da38	119
204fb681 PF	120	radv_reset(ra);
204fb681 PF	121
204f99d2 PF	122	sd_radv_detach_event(ra);
	123	return mfree(ra);
	124	}
	125
204fb681 PF	126	static int radv_send(sd_radv ra, const struct in6_addr dst,
204fb681 PF	127	const uint32_t router_lifetime) {
77baf5ae PF	128	static const struct ether_addr mac_zero = {};
	129	sd_radv_prefix *p;
	130	struct sockaddr_in6 dst_addr = {
	131	.sin6_family = AF_INET6,
	132	.sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
	133	};
	134	struct nd_router_advert adv = {};
	135	struct {
	136	struct nd_opt_hdr opthdr;
	137	struct ether_addr slladdr;
	138	} _packed_ opt_mac = {
	139	.opthdr = {
	140	.nd_opt_type = ND_OPT_SOURCE_LINKADDR,
	141	.nd_opt_len = (sizeof(struct nd_opt_hdr) +
	142	sizeof(struct ether_addr) - 1) /8 + 1,
	143	},
	144	};
	145	struct nd_opt_mtu opt_mtu = {
	146	.nd_opt_mtu_type = ND_OPT_MTU,
	147	.nd_opt_mtu_len = 1,
	148	};
6852c0f6 PF	149	/* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
	150	and DNSSL */
	151	struct iovec iov[5 + ra->n_prefixes];
77baf5ae PF	152	struct msghdr msg = {
	153	.msg_name = &dst_addr,
	154	.msg_namelen = sizeof(dst_addr),
	155	.msg_iov = iov,
	156	};
d601b566 PF	157	usec_t time_now;
	158	int r;
	159
	160	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	161	if (r < 0)
	162	return r;
77baf5ae	163
88d5a3db	164	if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) dst))
77baf5ae	165	dst_addr.sin6_addr = *dst;
88d5a3db	166
77baf5ae PF	167	adv.nd_ra_type = ND_ROUTER_ADVERT;
	168	adv.nd_ra_curhoplimit = ra->hop_limit;
	169	adv.nd_ra_flags_reserved = ra->flags;
	170	adv.nd_ra_router_lifetime = htobe16(router_lifetime);
	171	iov[msg.msg_iovlen].iov_base = &adv;
	172	iov[msg.msg_iovlen].iov_len = sizeof(adv);
	173	msg.msg_iovlen++;
	174
	175	/* MAC address is optional, either because the link does not use L2
	176	addresses or load sharing is desired. See RFC 4861, Section 4.2 */
	177	if (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
	178	opt_mac.slladdr = ra->mac_addr;
	179	iov[msg.msg_iovlen].iov_base = &opt_mac;
	180	iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
	181	msg.msg_iovlen++;
	182	}
	183
	184	if (ra->mtu) {
	185	opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
	186	iov[msg.msg_iovlen].iov_base = &opt_mtu;
	187	iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
	188	msg.msg_iovlen++;
	189	}
	190
	191	LIST_FOREACH(prefix, p, ra->prefixes) {
d601b566 PF	192	if (p->valid_until) {
	193
	194	if (time_now > p->valid_until)
	195	p->opt.valid_lifetime = 0;
	196	else
	197	p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);
	198
	199	if (time_now > p->preferred_until)
	200	p->opt.preferred_lifetime = 0;
	201	else
	202	p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
	203	}
77baf5ae PF	204	iov[msg.msg_iovlen].iov_base = &p->opt;
	205	iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
	206	msg.msg_iovlen++;
	207	}
	208
e9c6da38 PF	209	if (ra->rdnss) {
	210	iov[msg.msg_iovlen].iov_base = ra->rdnss;
	211	iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
	212	msg.msg_iovlen++;
	213	}
	214
e965d6ab PF	215	if (ra->dnssl) {
	216	iov[msg.msg_iovlen].iov_base = ra->dnssl;
	217	iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
	218	msg.msg_iovlen++;
	219	}
	220
77baf5ae PF	221	if (sendmsg(ra->fd, &msg, 0) < 0)
77baf5ae PF	222	return -errno;
204fb681	223
77baf5ae	224	return 0;
204fb681 PF	225	}
204fb681 PF	226
88d5a3db PF	227	static int radv_recv(sd_event_source s, int fd, uint32_t revents, void userdata) {
	228	sd_radv *ra = userdata;
	229	_cleanup_free_ char *addr = NULL;
	230	struct in6_addr src;
	231	triple_timestamp timestamp;
	232	int r;
	233	ssize_t buflen;
	234	_cleanup_free_ char *buf = NULL;
	235
	236	assert(s);
	237	assert(ra);
	238	assert(ra->event);
	239
	240	buflen = next_datagram_size_fd(fd);
	241
	242	if ((unsigned) buflen < sizeof(struct nd_router_solicit))
	243	return log_radv("Too short packet received");
	244
	245	buf = new0(char, buflen);
	246	if (!buf)
	247	return 0;
	248
	249	r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
	250	if (r < 0) {
	251	switch (r) {
	252	case -EADDRNOTAVAIL:
	253	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
	254	log_radv("Received RS from non-link-local address %s. Ignoring", addr);
	255	break;
	256
	257	case -EMULTIHOP:
	258	log_radv("Received RS with invalid hop limit. Ignoring.");
	259	break;
	260
	261	case -EPFNOSUPPORT:
	262	log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
	263	break;
	264
	265	default:
	266	log_radv_warning_errno(r, "Error receiving from ICMPv6 socket: %m");
	267	break;
	268	}
	269
	270	return 0;
	271	}
	272
	273	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
	274
	275	r = radv_send(ra, &src, ra->lifetime);
	276	if (r < 0)
	277	log_radv_warning_errno(r, "Unable to send solicited Router Advertisment to %s: %m", addr);
	278	else
	279	log_radv("Sent solicited Router Advertisement to %s", addr);
	280
	281	return 0;
	282	}
	283
204fb681 PF	284	static usec_t radv_compute_timeout(usec_t min, usec_t max) {
	285	assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
	286
	287	return min + (random_u32() % (max - min));
	288	}
	289
	290	static int radv_timeout(sd_event_source s, uint64_t usec, void userdata) {
	291	int r;
	292	sd_radv *ra = userdata;
	293	usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
	294	usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
	295	usec_t time_now, timeout;
	296	char time_string[FORMAT_TIMESPAN_MAX];
	297
	298	assert(s);
	299	assert(ra);
	300	assert(ra->event);
	301
	302	ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
	303
	304	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	305	if (r < 0)
	306	goto fail;
	307
	308	r = radv_send(ra, NULL, ra->lifetime);
	309	if (r < 0)
	310	log_radv_warning_errno(r, "Unable to send Router Advertisement: %m");
	311
	312	/* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
	313	if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
	314	max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
	315	min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
	316	}
	317
	318	timeout = radv_compute_timeout(min_timeout, max_timeout);
	319
	320	log_radv("Next Router Advertisement in %s",
	321	format_timespan(time_string, FORMAT_TIMESPAN_MAX,
	322	timeout, USEC_PER_SEC));
	323
	324	r = sd_event_add_time(ra->event, &ra->timeout_event_source,
	325	clock_boottime_or_monotonic(),
	326	time_now + timeout, MSEC_PER_SEC,
	327	radv_timeout, ra);
	328	if (r < 0)
	329	goto fail;
	330
	331	r = sd_event_source_set_priority(ra->timeout_event_source,
	332	ra->event_priority);
	333	if (r < 0)
	334	goto fail;
	335
	336	r = sd_event_source_set_description(ra->timeout_event_source,
	337	"radv-timeout");
	338	if (r < 0)
	339	goto fail;
	340
	341	ra->ra_sent++;
	342
	343	fail:
	344	if (r < 0)
	345	sd_radv_stop(ra);
	346
	347	return 0;
348	}
349
204f99d2	350	_public_ int sd_radv_stop(sd_radv *ra) {
204fb681 PF	351	int r;
204fb681 PF	352
204f99d2 PF	353	assert_return(ra, -EINVAL);
	354
	355	log_radv("Stopping IPv6 Router Advertisement daemon");
	356
204fb681 PF	357	/* RFC 4861, Section 6.2.5, send at least one Router Advertisement
	358	with zero lifetime */
	359	r = radv_send(ra, NULL, 0);
	360	if (r < 0)
	361	log_radv_warning_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
	362
	363	radv_reset(ra);
77baf5ae	364	ra->fd = safe_close(ra->fd);
204f99d2 PF	365	ra->state = SD_RADV_STATE_IDLE;
	366
	367	return 0;
	368	}
	369
	370	_public_ int sd_radv_start(sd_radv *ra) {
204fb681 PF	371	int r = 0;
204fb681 PF	372
204f99d2 PF	373	assert_return(ra, -EINVAL);
	374	assert_return(ra->event, -EINVAL);
	375	assert_return(ra->ifindex > 0, -EINVAL);
	376
	377	if (ra->state != SD_RADV_STATE_IDLE)
	378	return 0;
	379
204fb681 PF	380	r = sd_event_add_time(ra->event, &ra->timeout_event_source,
	381	clock_boottime_or_monotonic(), 0, 0,
	382	radv_timeout, ra);
	383	if (r < 0)
	384	goto fail;
	385
	386	r = sd_event_source_set_priority(ra->timeout_event_source,
	387	ra->event_priority);
	388	if (r < 0)
	389	goto fail;
	390
	391	(void) sd_event_source_set_description(ra->timeout_event_source,
	392	"radv-timeout");
	393
77baf5ae PF	394	r = icmp6_bind_router_advertisement(ra->ifindex);
	395	if (r < 0)
	396	goto fail;
	397
	398	ra->fd = r;
88d5a3db PF	399
	400	r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
	401	if (r < 0)
	402	goto fail;
	403
	404	r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
	405	if (r < 0)
	406	goto fail;
	407
	408	(void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
77baf5ae	409
204f99d2 PF	410	ra->state = SD_RADV_STATE_ADVERTISING;
	411
	412	log_radv("Started IPv6 Router Advertisement daemon");
	413
	414	return 0;
204fb681 PF	415
	416	fail:
	417	radv_reset(ra);
	418
	419	return r;
204f99d2 PF	420	}
	421
	422	_public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
	423	assert_return(ra, -EINVAL);
	424	assert_return(ifindex >= -1, -EINVAL);
	425
	426	if (ra->state != SD_RADV_STATE_IDLE)
	427	return -EBUSY;
	428
	429	ra->ifindex = ifindex;
	430
	431	return 0;
	432	}
	433
	434	_public_ int sd_radv_set_mac(sd_radv ra, const struct ether_addr mac_addr) {
	435	assert_return(ra, -EINVAL);
	436
	437	if (ra->state != SD_RADV_STATE_IDLE)
	438	return -EBUSY;
	439
	440	if (mac_addr)
	441	ra->mac_addr = *mac_addr;
	442	else
	443	zero(ra->mac_addr);
	444
	445	return 0;
	446	}
	447
	448	_public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
	449	assert_return(ra, -EINVAL);
	450	assert_return(mtu >= 1280, -EINVAL);
	451
204f99d2 PF	452	ra->mtu = mtu;
	453
	454	return 0;
	455	}
	456
	457	_public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
	458	assert_return(ra, -EINVAL);
	459
	460	if (ra->state != SD_RADV_STATE_IDLE)
	461	return -EBUSY;
	462
	463	ra->hop_limit = hop_limit;
	464
	465	return 0;
	466	}
	467
	468	_public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
	469	assert_return(ra, -EINVAL);
	470
	471	if (ra->state != SD_RADV_STATE_IDLE)
	472	return -EBUSY;
	473
	474	/* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
	475	preference value MUST be set to (00) by the sender..." */
	476	if (router_lifetime == 0 &&
	477	(ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
	478	return -ETIME;
	479
	480	ra->lifetime = router_lifetime;
	481
	482	return 0;
	483	}
	484
	485	_public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
	486	assert_return(ra, -EINVAL);
	487
	488	if (ra->state != SD_RADV_STATE_IDLE)
	489	return -EBUSY;
	490
	491	SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
	492
	493	return 0;
	494	}
	495
	496	_public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
	497	assert_return(ra, -EINVAL);
	498
	499	if (ra->state != SD_RADV_STATE_IDLE)
	500	return -EBUSY;
	501
	502	SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
	503
	504	return 0;
	505	}
	506
	507	_public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
	508	int r = 0;
	509
	510	assert_return(ra, -EINVAL);
	511	assert_return(IN_SET(preference,
	512	SD_NDISC_PREFERENCE_LOW,
	513	SD_NDISC_PREFERENCE_MEDIUM,
	514	SD_NDISC_PREFERENCE_HIGH), -EINVAL);
	515
516	ra->flags = (ra->flags & ~(0x3 << 3)) \| (preference << 3);
517
518	return r;
519	}
520
d601b566	521	_public_ int sd_radv_add_prefix(sd_radv ra, sd_radv_prefix p, bool dynamic) {
204f99d2	522	sd_radv_prefix *cur;
d601b566	523	int r;
204f99d2	524	_cleanup_free_ char *addr_p = NULL;
d601b566 PF	525	char time_string_preferred[FORMAT_TIMESPAN_MAX];
	526	char time_string_valid[FORMAT_TIMESPAN_MAX];
	527	usec_t time_now, valid, preferred, valid_until, preferred_until;
204f99d2 PF	528
	529	assert_return(ra, -EINVAL);
	530
	531	if (!p)
	532	return -EINVAL;
	533
	534	LIST_FOREACH(prefix, cur, ra->prefixes) {
204f99d2 PF	535
	536	r = in_addr_prefix_intersect(AF_INET6,
	537	(union in_addr_union*) &cur->opt.in6_addr,
	538	cur->opt.prefixlen,
	539	(union in_addr_union*) &p->opt.in6_addr,
	540	p->opt.prefixlen);
	541	if (r > 0) {
	542	_cleanup_free_ char *addr_cur = NULL;
	543
204f99d2 PF	544	(void) in_addr_to_string(AF_INET6,
	545	(union in_addr_union*) &p->opt.in6_addr,
	546	&addr_p);
	547
d601b566 PF	548	if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
	549	goto update;
	550
	551	(void) in_addr_to_string(AF_INET6,
	552	(union in_addr_union*) &cur->opt.in6_addr,
	553	&addr_cur);
204f99d2 PF	554	log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
	555	addr_cur, cur->opt.prefixlen,
	556	addr_p, p->opt.prefixlen);
	557
	558	return -EEXIST;
	559	}
	560	}
	561
	562	p = sd_radv_prefix_ref(p);
	563
	564	LIST_APPEND(prefix, ra->prefixes, p);
	565
	566	ra->n_prefixes++;
	567
	568	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
d601b566 PF	569
	570	if (!dynamic) {
	571	log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
	572	return 0;
	573	}
	574
	575	cur = p;
	576
	577	update:
	578	r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
	579	if (r < 0)
	580	return r;
	581
	582	valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
	583	valid_until = usec_add(valid, time_now);
	584	if (valid_until == USEC_INFINITY)
	585	return -EOVERFLOW;
	586
	587	preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
	588	preferred_until = usec_add(preferred, time_now);
	589	if (preferred_until == USEC_INFINITY)
	590	return -EOVERFLOW;
	591
	592	cur->valid_until = valid_until;
	593	cur->preferred_until = preferred_until;
	594
	595	log_radv("%s prefix %s/%u preferred %s valid %s",
	596	cur? "Updated": "Added",
	597	addr_p, p->opt.prefixlen,
	598	format_timespan(time_string_preferred, FORMAT_TIMESPAN_MAX,
	599	preferred, USEC_PER_SEC),
	600	format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX,
	601	valid, USEC_PER_SEC));
204f99d2 PF	602
	603	return 0;
	604	}
	605
34c169c4 PF	606	_public_ sd_radv_prefix sd_radv_remove_prefix(sd_radv ra,
	607	struct in6_addr *prefix,
	608	uint8_t prefixlen) {
	609	sd_radv_prefix cur, next;
	610
	611	assert_return(ra, NULL);
	612	assert_return(prefix, NULL);
	613
	614	LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
	615	if (prefixlen != cur->opt.prefixlen)
	616	continue;
	617
	618	if (!in_addr_equal(AF_INET6,
	619	(union in_addr_union *)prefix,
	620	(union in_addr_union *)&cur->opt.in6_addr))
	621	continue;
	622
	623	LIST_REMOVE(prefix, ra->prefixes, cur);
	624	ra->n_prefixes--;
	625
	626	break;
	627	}
	628
	629	return cur;
	630	}
	631
e9c6da38 PF	632	_public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
	633	const struct in6_addr *dns, size_t n_dns) {
	634	_cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
	635	size_t len;
	636
	637	assert_return(ra, -EINVAL);
	638	assert_return(n_dns < 128, -EINVAL);
	639
	640	if (!dns \|\| n_dns == 0) {
	641	ra->rdnss = mfree(ra->rdnss);
	642	ra->n_rdnss = 0;
	643
	644	return 0;
	645	}
	646
	647	len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
	648
	649	opt_rdnss = malloc0(len);
	650	if (!opt_rdnss)
	651	return -ENOMEM;
	652
	653	opt_rdnss->type = SD_RADV_OPT_RDNSS;
	654	opt_rdnss->length = len / 8;
	655	opt_rdnss->lifetime = htobe32(lifetime);
	656
	657	memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
	658
1cc6c93a	659	free_and_replace(ra->rdnss, opt_rdnss);
e9c6da38 PF	660
	661	ra->n_rdnss = n_dns;
	662
	663	return 0;
	664	}
	665
e965d6ab PF	666	_public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
	667	char **search_list) {
	668	_cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
	669	size_t len = 0;
	670	char **s;
	671	uint8_t *p;
	672
	673	assert_return(ra, -EINVAL);
	674
	675	if (!search_list \|\| *search_list == NULL) {
	676	ra->dnssl = mfree(ra->dnssl);
	677
	678	return 0;
	679	}
	680
	681	STRV_FOREACH(s, search_list)
	682	len += strlen(*s) + 2;
	683
	684	len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
	685
	686	opt_dnssl = malloc0(len);
	687	if (!opt_dnssl)
	688	return -ENOMEM;
	689
	690	opt_dnssl->type = SD_RADV_OPT_DNSSL;
	691	opt_dnssl->length = len / 8;
	692	opt_dnssl->lifetime = htobe32(lifetime);
	693
	694	p = (uint8_t *)(opt_dnssl + 1);
	695	len -= sizeof(struct sd_radv_opt_dns);
	696
	697	STRV_FOREACH(s, search_list) {
	698	int r;
	699
	700	r = dns_name_to_wire_format(*s, p, len, false);
	701	if (r < 0)
	702	return r;
	703
	704	if (len < (size_t)r)
	705	return -ENOBUFS;
	706
	707	p += r;
	708	len -= r;
	709	}
	710
1cc6c93a	711	free_and_replace(ra->dnssl, opt_dnssl);
e965d6ab PF	712
	713	return 0;
	714	}
	715
04473969 PF	716	_public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
	717	_cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
	718
	719	assert_return(ret, -EINVAL);
	720
	721	p = new0(sd_radv_prefix, 1);
	722	if (!p)
	723	return -ENOMEM;
	724
	725	p->n_ref = 1;
	726
	727	p->opt.type = ND_OPT_PREFIX_INFORMATION;
	728	p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
	729
	730	p->opt.prefixlen = 64;
	731
	732	/* RFC 4861, Section 6.2.1 */
	733	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
	734	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
	735	p->opt.preferred_lifetime = htobe32(604800);
	736	p->opt.valid_lifetime = htobe32(2592000);
	737
204f99d2 PF	738	LIST_INIT(prefix, p);
204f99d2 PF	739
1cc6c93a	740	*ret = TAKE_PTR(p);
04473969 PF	741
	742	return 0;
	743	}
	744
	745	_public_ sd_radv_prefix sd_radv_prefix_ref(sd_radv_prefix p) {
	746	if (!p)
	747	return NULL;
	748
	749	assert(p->n_ref > 0);
	750	p->n_ref++;
	751
	752	return p;
	753	}
	754
	755	_public_ sd_radv_prefix sd_radv_prefix_unref(sd_radv_prefix p) {
	756	if (!p)
	757	return NULL;
	758
	759	assert(p->n_ref > 0);
	760	p->n_ref--;
	761
	762	if (p->n_ref > 0)
	763	return NULL;
	764
	765	return mfree(p);
	766	}
	767
	768	_public_ int sd_radv_prefix_set_prefix(sd_radv_prefix p, struct in6_addr in6_addr,
	769	unsigned char prefixlen) {
	770	assert_return(p, -EINVAL);
	771	assert_return(in6_addr, -EINVAL);
	772
	773	if (prefixlen < 3 \|\| prefixlen > 128)
	774	return -EINVAL;
	775
	776	if (prefixlen > 64)
	777	/* unusual but allowed, log it */
	778	log_radv("Unusual prefix length %d greater than 64", prefixlen);
	779
	780	p->opt.in6_addr = *in6_addr;
	781	p->opt.prefixlen = prefixlen;
	782
	783	return 0;
	784	}
	785
	786	_public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
	787	assert_return(p, -EINVAL);
	788
	789	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
	790
	791	return 0;
	792	}
	793
	794	_public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
	795	int address_autoconfiguration) {
	796	assert_return(p, -EINVAL);
	797
	798	SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
	799
	800	return 0;
	801	}
	802
	803	_public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
	804	uint32_t valid_lifetime) {
805	assert_return(p, -EINVAL);
806
807	p->opt.valid_lifetime = htobe32(valid_lifetime);
808
809	return 0;
810	}
811
812	_public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
813	uint32_t preferred_lifetime) {
814	assert_return(p, -EINVAL);
815
816	p->opt.preferred_lifetime = htobe32(preferred_lifetime);
817
818	return 0;
819	}