Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 953 insertions, 0 deletions

diff --git a/src/libsystemd-network/sd-radv.c b/src/libsystemd-network/sd-radv.c
new file mode 100644
index 0000000..8beb845
--- /dev/null
+++ b/src/libsystemd-network/sd-radv.c
@@ -0,0 +1,953 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+  Copyright © 2017 Intel Corporation. All rights reserved.
+***/
+
+#include <netinet/icmp6.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "sd-radv.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 "io-util.h"
+#include "macro.h"
+#include "memory-util.h"
+#include "radv-internal.h"
+#include "random-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "strv.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;
+}
+
+_public_ int sd_radv_is_running(sd_radv *ra) {
+        assert_return(ra, false);
+
+        return ra->state != SD_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_unref(ra->recv_event_source);
+
+        ra->ra_sent = 0;
+}
+
+static sd_radv *radv_free(sd_radv *ra) {
+        if (!ra)
+                return NULL;
+
+        while (ra->prefixes) {
+                sd_radv_prefix *p = ra->prefixes;
+
+                LIST_REMOVE(prefix, ra->prefixes, p);
+                sd_radv_prefix_unref(p);
+        }
+
+        while (ra->route_prefixes) {
+                sd_radv_route_prefix *p = ra->route_prefixes;
+
+                LIST_REMOVE(prefix, ra->route_prefixes, p);
+                sd_radv_route_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_route_prefix *rt;
+        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, N routes, RDNSS
+           and DNSSL */
+        struct iovec iov[5 + ra->n_prefixes + ra->n_route_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++] = IOVEC_MAKE(&adv, sizeof(adv));
+
+        /* 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++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
+        }
+
+        if (ra->mtu) {
+                opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
+                iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
+        }
+
+        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++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
+        }
+
+        LIST_FOREACH(prefix, rt, ra->route_prefixes)
+                iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
+
+        if (ra->rdnss)
+                iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
+
+        if (ra->dnssl)
+                iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
+
+        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 (buflen < 0)
+                return (int) buflen;
+
+        buf = new0(char, buflen);
+        if (!buf)
+                return -ENOMEM;
+
+        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;
+        }
+
+        if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
+                log_radv("Too short packet received");
+                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", strnull(addr));
+        else
+                log_radv("Sent solicited Router Advertisement to %s", strnull(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);
+
+        /* RFC 4861: min must be no less than 3s, max must be no less than 4s */
+        min = MAX(min, 3*USEC_PER_SEC);
+        max = MAX(max, 4*USEC_PER_SEC);
+
+        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;
+        }
+
+        /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
+           so lower the interval here */
+        if (ra->lifetime > 0 && (ra->lifetime * USEC_PER_SEC) < max_timeout) {
+                max_timeout = ra->lifetime * USEC_PER_SEC;
+                min_timeout = max_timeout / 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;
+
+        if (!ra)
+                return 0;
+
+        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;
+
+        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 > 0, -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, uint16_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) {
+        assert_return(ra, -EINVAL);
+        assert_return(IN_SET(preference,
+                             SD_NDISC_PREFERENCE_LOW,
+                             SD_NDISC_PREFERENCE_MEDIUM,
+                             SD_NDISC_PREFERENCE_HIGH), -EINVAL);
+
+        /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
+         * to (00) by the sender..." */
+        if (ra->lifetime == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
+                return -EINVAL;
+
+        ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
+
+        return 0;
+}
+
+_public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, int 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;
+
+        /* Refuse prefixes that don't have a prefix set */
+        if (IN6_IS_ADDR_UNSPECIFIED(&p->opt.in6_addr))
+                return -ENOEXEC;
+
+        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;
+
+        /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
+        if (ra->ra_sent > 0) {
+                r = radv_send(ra, NULL, ra->lifetime);
+                if (r < 0)
+                        log_radv_errno(r, "Unable to send Router Advertisement for added prefix: %m");
+                else
+                        log_radv("Sent Router Advertisement for added prefix");
+        }
+
+ 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("Updated prefix %s/%u preferred %s valid %s",
+                 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--;
+                sd_radv_prefix_unref(cur);
+
+                break;
+        }
+
+        return cur;
+}
+
+_public_ int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p, int dynamic) {
+        char time_string_valid[FORMAT_TIMESPAN_MAX];
+        usec_t time_now, valid, valid_until;
+        _cleanup_free_ char *pretty = NULL;
+        sd_radv_route_prefix *cur;
+        int r;
+
+        assert_return(ra, -EINVAL);
+
+        if (!p)
+                return -EINVAL;
+
+        (void) in_addr_to_string(AF_INET6,
+                                 (union in_addr_union*) &p->opt.in6_addr,
+                                 &pretty);
+
+        LIST_FOREACH(prefix, cur, ra->route_prefixes) {
+                _cleanup_free_ char *addr = NULL;
+
+                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)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                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);
+                log_radv("IPv6 route prefix %s/%u already configured, ignoring %s/%u",
+                         strempty(addr), cur->opt.prefixlen,
+                         strempty(pretty), p->opt.prefixlen);
+
+                return -EEXIST;
+        }
+
+        p = sd_radv_route_prefix_ref(p);
+
+        LIST_APPEND(prefix, ra->route_prefixes, p);
+        ra->n_route_prefixes++;
+
+        if (!dynamic) {
+                log_radv("Added prefix %s/%u", strempty(pretty), p->opt.prefixlen);
+                return 0;
+        }
+
+        /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
+        if (ra->ra_sent > 0) {
+                r = radv_send(ra, NULL, ra->lifetime);
+                if (r < 0)
+                        log_radv_errno(r, "Unable to send Router Advertisement for added route prefix: %m");
+                else
+                        log_radv("Sent Router Advertisement for added route prefix");
+        }
+
+ update:
+        r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
+        if (r < 0)
+                return r;
+
+        valid = be32toh(p->opt.lifetime) * USEC_PER_SEC;
+        valid_until = usec_add(valid, time_now);
+        if (valid_until == USEC_INFINITY)
+                return -EOVERFLOW;
+
+        log_radv("Updated route prefix %s/%u valid %s",
+                 strempty(pretty), p->opt.prefixlen,
+                 format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX, valid, USEC_PER_SEC));
+
+        return 0;
+}
+
+_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) {
+        sd_radv_prefix *p;
+
+        assert_return(ret, -EINVAL);
+
+        p = new(sd_radv_prefix, 1);
+        if (!p)
+                return -ENOMEM;
+
+        *p = (sd_radv_prefix) {
+                .n_ref = 1,
+
+                .opt.type = ND_OPT_PREFIX_INFORMATION,
+                .opt.length = (sizeof(p->opt) - 1)/8 + 1,
+                .opt.prefixlen = 64,
+
+                /* RFC 4861, Section 6.2.1 */
+                .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
+
+                .opt.preferred_lifetime = htobe32(604800),
+                .opt.valid_lifetime = htobe32(2592000),
+        };
+
+        *ret = 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_get_prefix(sd_radv_prefix *p, struct in6_addr *ret_in6_addr,
+                                       unsigned char *ret_prefixlen) {
+        assert_return(p, -EINVAL);
+        assert_return(ret_in6_addr, -EINVAL);
+        assert_return(ret_prefixlen, -EINVAL);
+
+        *ret_in6_addr = p->opt.in6_addr;
+        *ret_prefixlen = p->opt.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;
+}
+
+_public_ int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
+        sd_radv_route_prefix *p;
+
+        assert_return(ret, -EINVAL);
+
+        p = new(sd_radv_route_prefix, 1);
+        if (!p)
+                return -ENOMEM;
+
+        *p = (sd_radv_route_prefix) {
+                .n_ref = 1,
+
+                .opt.type = SD_RADV_OPT_ROUTE_INFORMATION,
+                .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
+                .opt.prefixlen = 64,
+
+                .opt.lifetime = htobe32(604800),
+        };
+
+        *ret = p;
+        return 0;
+}
+
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
+
+_public_ int sd_radv_prefix_set_route_prefix(sd_radv_route_prefix *p, const struct in6_addr *in6_addr,
+                                             unsigned char prefixlen) {
+        assert_return(p, -EINVAL);
+        assert_return(in6_addr, -EINVAL);
+
+        if (prefixlen > 128)
+                return -EINVAL;
+
+        if (prefixlen > 64)
+                /* unusual but allowed, log it */
+                log_radv("Unusual prefix length %u greater than 64", prefixlen);
+
+        p->opt.in6_addr = *in6_addr;
+        p->opt.prefixlen = prefixlen;
+
+        return 0;
+}
+
+_public_ int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint32_t valid_lifetime) {
+        assert_return(p, -EINVAL);
+
+        p->opt.lifetime = htobe32(valid_lifetime);
+
+        return 0;
+}