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-rw-r--r--src/core/ndisc/nm-fake-ndisc.c415
-rw-r--r--src/core/ndisc/nm-fake-ndisc.h64
-rw-r--r--src/core/ndisc/nm-lndp-ndisc.c826
-rw-r--r--src/core/ndisc/nm-lndp-ndisc.h46
-rw-r--r--src/core/ndisc/nm-ndisc-private.h68
-rw-r--r--src/core/ndisc/nm-ndisc.c1830
-rw-r--r--src/core/ndisc/nm-ndisc.h278
-rw-r--r--src/core/ndisc/tests/meson.build26
-rw-r--r--src/core/ndisc/tests/test-ndisc-fake.c657
-rw-r--r--src/core/ndisc/tests/test-ndisc-linux.c85
10 files changed, 4295 insertions, 0 deletions
diff --git a/src/core/ndisc/nm-fake-ndisc.c b/src/core/ndisc/nm-fake-ndisc.c
new file mode 100644
index 00000000..ffe07ab6
--- /dev/null
+++ b/src/core/ndisc/nm-fake-ndisc.c
@@ -0,0 +1,415 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-fake-ndisc.h"
+
+#include <arpa/inet.h>
+
+#include "nm-ndisc-private.h"
+
+#define _NMLOG_PREFIX_NAME "ndisc-fake"
+
+/*****************************************************************************/
+
+typedef struct {
+    guint id;
+    guint when;
+
+    NMNDiscDHCPLevel dhcp_level;
+    GArray *         gateways;
+    GArray *         prefixes;
+    GArray *         dns_servers;
+    GArray *         dns_domains;
+    int              hop_limit;
+    guint32          mtu;
+} FakeRa;
+
+typedef struct {
+    struct in6_addr    network;
+    struct in6_addr    gateway;
+    gint64             expiry_msec;
+    gint64             expiry_preferred_msec;
+    int                plen;
+    NMIcmpv6RouterPref preference;
+} FakePrefix;
+
+/*****************************************************************************/
+
+enum {
+    RS_SENT,
+    LAST_SIGNAL,
+};
+static guint signals[LAST_SIGNAL] = {0};
+
+typedef struct {
+    guint   receive_ra_id;
+    GSList *ras;
+} NMFakeNDiscPrivate;
+
+struct _NMFakeRNDisc {
+    NMNDisc            parent;
+    NMFakeNDiscPrivate _priv;
+};
+
+struct _NMFakeRNDiscClass {
+    NMNDiscClass parent;
+};
+
+G_DEFINE_TYPE(NMFakeNDisc, nm_fake_ndisc, NM_TYPE_NDISC)
+
+#define NM_FAKE_NDISC_GET_PRIVATE(self) \
+    _NM_GET_PRIVATE(self, NMFakeNDisc, NM_IS_FAKE_NDISC, NMNDisc)
+
+/*****************************************************************************/
+
+static void
+fake_ra_free(gpointer data)
+{
+    FakeRa *ra = data;
+
+    g_array_free(ra->gateways, TRUE);
+    g_array_free(ra->prefixes, TRUE);
+    g_array_free(ra->dns_servers, TRUE);
+    g_array_free(ra->dns_domains, TRUE);
+    g_free(ra);
+}
+
+static void
+ra_dns_domain_free(gpointer data)
+{
+    g_free(((NMNDiscDNSDomain *) (data))->domain);
+}
+
+static FakeRa *
+find_ra(GSList *ras, guint id)
+{
+    GSList *iter;
+
+    for (iter = ras; iter; iter = iter->next) {
+        if (((FakeRa *) iter->data)->id == id)
+            return iter->data;
+    }
+    return NULL;
+}
+
+guint
+nm_fake_ndisc_add_ra(NMFakeNDisc *    self,
+                     guint            seconds_after_previous,
+                     NMNDiscDHCPLevel dhcp_level,
+                     int              hop_limit,
+                     guint32          mtu)
+{
+    NMFakeNDiscPrivate *priv    = NM_FAKE_NDISC_GET_PRIVATE(self);
+    static guint        counter = 1;
+    FakeRa *            ra;
+
+    ra              = g_malloc0(sizeof(*ra));
+    ra->id          = counter++;
+    ra->when        = seconds_after_previous;
+    ra->dhcp_level  = dhcp_level;
+    ra->hop_limit   = hop_limit;
+    ra->mtu         = mtu;
+    ra->gateways    = g_array_new(FALSE, FALSE, sizeof(NMNDiscGateway));
+    ra->prefixes    = g_array_new(FALSE, FALSE, sizeof(FakePrefix));
+    ra->dns_servers = g_array_new(FALSE, FALSE, sizeof(NMNDiscDNSServer));
+    ra->dns_domains = g_array_new(FALSE, FALSE, sizeof(NMNDiscDNSDomain));
+    g_array_set_clear_func(ra->dns_domains, ra_dns_domain_free);
+
+    priv->ras = g_slist_append(priv->ras, ra);
+    return ra->id;
+}
+
+void
+nm_fake_ndisc_add_gateway(NMFakeNDisc *      self,
+                          guint              ra_id,
+                          const char *       addr,
+                          gint64             expiry_msec,
+                          NMIcmpv6RouterPref preference)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(self);
+    FakeRa *            ra   = find_ra(priv->ras, ra_id);
+    NMNDiscGateway *    gw;
+
+    g_assert(ra);
+
+    gw = nm_g_array_append_new(ra->gateways, NMNDiscGateway);
+    if (inet_pton(AF_INET6, addr, &gw->address) != 1)
+        g_assert_not_reached();
+    gw->expiry_msec = expiry_msec;
+    gw->preference  = preference;
+}
+
+void
+nm_fake_ndisc_add_prefix(NMFakeNDisc *      self,
+                         guint              ra_id,
+                         const char *       network,
+                         guint              plen,
+                         const char *       gateway,
+                         gint64             expiry_msec,
+                         gint64             expiry_preferred_msec,
+                         NMIcmpv6RouterPref preference)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(self);
+    FakeRa *            ra   = find_ra(priv->ras, ra_id);
+    FakePrefix *        prefix;
+
+    g_assert(ra);
+
+    prefix  = nm_g_array_append_new(ra->prefixes, FakePrefix);
+    *prefix = (FakePrefix){
+        .plen                  = plen,
+        .expiry_msec           = expiry_msec,
+        .expiry_preferred_msec = expiry_preferred_msec,
+        .preference            = preference,
+    };
+    if (inet_pton(AF_INET6, network, &prefix->network) != 1)
+        g_assert_not_reached();
+    if (inet_pton(AF_INET6, gateway, &prefix->gateway) != 1)
+        g_assert_not_reached();
+}
+
+void
+nm_fake_ndisc_add_dns_server(NMFakeNDisc *self,
+                             guint        ra_id,
+                             const char * address,
+                             gint64       expiry_msec)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(self);
+    FakeRa *            ra   = find_ra(priv->ras, ra_id);
+    NMNDiscDNSServer *  dns;
+
+    g_assert(ra);
+
+    dns = nm_g_array_append_new(ra->dns_servers, NMNDiscDNSServer);
+
+    dns->expiry_msec = expiry_msec;
+    if (inet_pton(AF_INET6, address, &dns->address) != 1)
+        g_assert_not_reached();
+}
+
+void
+nm_fake_ndisc_add_dns_domain(NMFakeNDisc *self, guint ra_id, const char *domain, gint64 expiry_msec)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(self);
+    FakeRa *            ra   = find_ra(priv->ras, ra_id);
+    NMNDiscDNSDomain *  dns;
+
+    g_assert(ra);
+
+    dns = nm_g_array_append_new(ra->dns_domains, NMNDiscDNSDomain);
+
+    dns->domain      = g_strdup(domain);
+    dns->expiry_msec = expiry_msec;
+}
+
+gboolean
+nm_fake_ndisc_done(NMFakeNDisc *self)
+{
+    return !NM_FAKE_NDISC_GET_PRIVATE(self)->ras;
+}
+
+/*****************************************************************************/
+
+static gboolean
+send_rs(NMNDisc *ndisc, GError **error)
+{
+    _LOGT("send_rs()");
+    g_signal_emit(ndisc, signals[RS_SENT], 0);
+    return TRUE;
+}
+
+static gboolean
+receive_ra(gpointer user_data)
+{
+    NMFakeNDisc *        self     = user_data;
+    NMFakeNDiscPrivate * priv     = NM_FAKE_NDISC_GET_PRIVATE(self);
+    NMNDisc *            ndisc    = NM_NDISC(self);
+    NMNDiscDataInternal *rdata    = ndisc->rdata;
+    FakeRa *             ra       = priv->ras->data;
+    NMNDiscConfigMap     changed  = 0;
+    const gint64         now_msec = nm_utils_get_monotonic_timestamp_msec();
+    guint                i;
+    NMNDiscDHCPLevel     dhcp_level;
+
+    priv->receive_ra_id = 0;
+
+    /* preserve the "most managed" level  on updates. */
+    dhcp_level = MAX(rdata->public.dhcp_level, ra->dhcp_level);
+
+    if (rdata->public.dhcp_level != dhcp_level) {
+        rdata->public.dhcp_level = dhcp_level;
+        changed |= NM_NDISC_CONFIG_DHCP_LEVEL;
+    }
+
+    for (i = 0; i < ra->gateways->len; i++) {
+        const NMNDiscGateway *item = &g_array_index(ra->gateways, NMNDiscGateway, i);
+
+        if (nm_ndisc_add_gateway(ndisc, item, now_msec))
+            changed |= NM_NDISC_CONFIG_GATEWAYS;
+    }
+
+    for (i = 0; i < ra->prefixes->len; i++) {
+        FakePrefix *       item  = &g_array_index(ra->prefixes, FakePrefix, i);
+        const NMNDiscRoute route = {
+            .network     = item->network,
+            .plen        = item->plen,
+            .gateway     = item->gateway,
+            .expiry_msec = item->expiry_msec,
+            .preference  = item->preference,
+        };
+
+        g_assert(route.plen > 0 && route.plen <= 128);
+
+        if (nm_ndisc_add_route(ndisc, &route, now_msec))
+            changed |= NM_NDISC_CONFIG_ROUTES;
+
+        if (item->plen == 64) {
+            const NMNDiscAddress address = {
+                .address               = item->network,
+                .expiry_msec           = item->expiry_msec,
+                .expiry_preferred_msec = item->expiry_preferred_msec,
+                .dad_counter           = 0,
+            };
+
+            if (nm_ndisc_complete_and_add_address(ndisc, &address, now_msec))
+                changed |= NM_NDISC_CONFIG_ADDRESSES;
+        }
+    }
+
+    for (i = 0; i < ra->dns_servers->len; i++) {
+        const NMNDiscDNSServer *item = &g_array_index(ra->dns_servers, NMNDiscDNSServer, i);
+
+        if (nm_ndisc_add_dns_server(ndisc, item, now_msec))
+            changed |= NM_NDISC_CONFIG_DNS_SERVERS;
+    }
+
+    for (i = 0; i < ra->dns_domains->len; i++) {
+        const NMNDiscDNSDomain *item = &g_array_index(ra->dns_domains, NMNDiscDNSDomain, i);
+
+        if (nm_ndisc_add_dns_domain(ndisc, item, now_msec))
+            changed |= NM_NDISC_CONFIG_DNS_DOMAINS;
+    }
+
+    if (rdata->public.mtu != ra->mtu) {
+        rdata->public.mtu = ra->mtu;
+        changed |= NM_NDISC_CONFIG_MTU;
+    }
+
+    if (rdata->public.hop_limit != ra->hop_limit) {
+        rdata->public.hop_limit = ra->hop_limit;
+        changed |= NM_NDISC_CONFIG_HOP_LIMIT;
+    }
+
+    priv->ras = g_slist_remove(priv->ras, priv->ras->data);
+    fake_ra_free(ra);
+
+    nm_ndisc_ra_received(NM_NDISC(self), now_msec, changed);
+
+    /* Schedule next RA */
+    if (priv->ras) {
+        ra                  = priv->ras->data;
+        priv->receive_ra_id = g_timeout_add_seconds(ra->when, receive_ra, self);
+    }
+
+    return G_SOURCE_REMOVE;
+}
+
+static void
+start(NMNDisc *ndisc)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(ndisc);
+    FakeRa *            ra;
+
+    /* Queue up the first fake RA */
+    g_assert(priv->ras);
+    ra = priv->ras->data;
+
+    g_assert(!priv->receive_ra_id);
+    priv->receive_ra_id = g_timeout_add_seconds(ra->when, receive_ra, ndisc);
+}
+
+static void
+stop(NMNDisc *ndisc)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(ndisc);
+
+    nm_clear_g_source(&priv->receive_ra_id);
+}
+
+void
+nm_fake_ndisc_emit_new_ras(NMFakeNDisc *self)
+{
+    if (!NM_FAKE_NDISC_GET_PRIVATE(self)->receive_ra_id)
+        start(NM_NDISC(self));
+}
+
+/*****************************************************************************/
+
+static void
+nm_fake_ndisc_init(NMFakeNDisc *fake_ndisc)
+{}
+
+NMNDisc *
+nm_fake_ndisc_new(int ifindex, const char *ifname)
+{
+    return g_object_new(NM_TYPE_FAKE_NDISC,
+                        NM_NDISC_IFINDEX,
+                        ifindex,
+                        NM_NDISC_IFNAME,
+                        ifname,
+                        NM_NDISC_NODE_TYPE,
+                        (int) NM_NDISC_NODE_TYPE_HOST,
+                        NM_NDISC_STABLE_TYPE,
+                        (int) NM_UTILS_STABLE_TYPE_UUID,
+                        NM_NDISC_NETWORK_ID,
+                        "fake",
+                        NM_NDISC_MAX_ADDRESSES,
+                        NM_NDISC_MAX_ADDRESSES_DEFAULT,
+                        NM_NDISC_ROUTER_SOLICITATIONS,
+                        NM_NDISC_ROUTER_SOLICITATIONS_DEFAULT,
+                        NM_NDISC_ROUTER_SOLICITATION_INTERVAL,
+                        NM_NDISC_RFC4861_RTR_SOLICITATION_INTERVAL,
+                        NM_NDISC_RA_TIMEOUT,
+                        30u,
+                        NULL);
+}
+
+static void
+dispose(GObject *object)
+{
+    NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE(object);
+
+    nm_clear_g_source(&priv->receive_ra_id);
+
+    g_slist_free_full(priv->ras, fake_ra_free);
+    priv->ras = NULL;
+
+    G_OBJECT_CLASS(nm_fake_ndisc_parent_class)->dispose(object);
+}
+
+static void
+nm_fake_ndisc_class_init(NMFakeNDiscClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS(klass);
+    NMNDiscClass *ndisc_class  = NM_NDISC_CLASS(klass);
+
+    object_class->dispose = dispose;
+
+    ndisc_class->start   = start;
+    ndisc_class->stop    = stop;
+    ndisc_class->send_rs = send_rs;
+
+    signals[RS_SENT] = g_signal_new(NM_FAKE_NDISC_RS_SENT,
+                                    G_OBJECT_CLASS_TYPE(klass),
+                                    G_SIGNAL_RUN_FIRST,
+                                    0,
+                                    NULL,
+                                    NULL,
+                                    NULL,
+                                    G_TYPE_NONE,
+                                    0);
+}
diff --git a/src/core/ndisc/nm-fake-ndisc.h b/src/core/ndisc/nm-fake-ndisc.h
new file mode 100644
index 00000000..677f15fc
--- /dev/null
+++ b/src/core/ndisc/nm-fake-ndisc.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_FAKE_NDISC_H__
+#define __NETWORKMANAGER_FAKE_NDISC_H__
+
+#include "nm-ndisc.h"
+
+#define NM_TYPE_FAKE_NDISC (nm_fake_ndisc_get_type())
+#define NM_FAKE_NDISC(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_FAKE_NDISC, NMFakeNDisc))
+#define NM_FAKE_NDISC_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_FAKE_NDISC, NMFakeNDiscClass))
+#define NM_IS_FAKE_NDISC(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_FAKE_NDISC))
+#define NM_IS_FAKE_NDISC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_FAKE_NDISC))
+#define NM_FAKE_NDISC_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_FAKE_NDISC, NMFakeNDiscClass))
+
+#define NM_FAKE_NDISC_RS_SENT "rs-sent"
+
+typedef struct _NMFakeRNDisc      NMFakeNDisc;
+typedef struct _NMFakeRNDiscClass NMFakeNDiscClass;
+
+GType nm_fake_ndisc_get_type(void);
+
+NMNDisc *nm_fake_ndisc_new(int ifindex, const char *ifname);
+
+guint nm_fake_ndisc_add_ra(NMFakeNDisc *    self,
+                           guint            seconds,
+                           NMNDiscDHCPLevel dhcp_level,
+                           int              hop_limit,
+                           guint32          mtu);
+
+void nm_fake_ndisc_add_gateway(NMFakeNDisc *      self,
+                               guint              ra_id,
+                               const char *       addr,
+                               gint64             expiry_msec,
+                               NMIcmpv6RouterPref preference);
+
+void nm_fake_ndisc_add_prefix(NMFakeNDisc *      self,
+                              guint              ra_id,
+                              const char *       network,
+                              guint              plen,
+                              const char *       gateway,
+                              gint64             expiry_msec,
+                              gint64             expiry_preferred_msec,
+                              NMIcmpv6RouterPref preference);
+
+void nm_fake_ndisc_add_dns_server(NMFakeNDisc *self,
+                                  guint        ra_id,
+                                  const char * address,
+                                  gint64       expiry_msec);
+
+void nm_fake_ndisc_add_dns_domain(NMFakeNDisc *self,
+                                  guint        ra_id,
+                                  const char * domain,
+                                  gint64       expiry_msec);
+
+void nm_fake_ndisc_emit_new_ras(NMFakeNDisc *self);
+
+gboolean nm_fake_ndisc_done(NMFakeNDisc *self);
+
+#endif /* __NETWORKMANAGER_FAKE_NDISC_H__ */
diff --git a/src/core/ndisc/nm-lndp-ndisc.c b/src/core/ndisc/nm-lndp-ndisc.c
new file mode 100644
index 00000000..f773478f
--- /dev/null
+++ b/src/core/ndisc/nm-lndp-ndisc.c
@@ -0,0 +1,826 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-lndp-ndisc.h"
+
+#include <arpa/inet.h>
+#include <netinet/icmp6.h>
+/* stdarg.h included because of a bug in ndp.h */
+#include <stdarg.h>
+#include <ndp.h>
+
+#include "nm-glib-aux/nm-str-buf.h"
+#include "systemd/nm-sd-utils-shared.h"
+#include "nm-ndisc-private.h"
+#include "NetworkManagerUtils.h"
+#include "platform/nm-platform.h"
+#include "nm-platform/nmp-netns.h"
+
+#define _NMLOG_PREFIX_NAME "ndisc-lndp"
+
+/*****************************************************************************/
+
+typedef struct {
+    struct ndp *ndp;
+    GSource *   event_source;
+} NMLndpNDiscPrivate;
+
+/*****************************************************************************/
+
+struct _NMLndpNDisc {
+    NMNDisc            parent;
+    NMLndpNDiscPrivate _priv;
+};
+
+struct _NMLndpNDiscClass {
+    NMNDiscClass parent;
+};
+
+/*****************************************************************************/
+
+G_DEFINE_TYPE(NMLndpNDisc, nm_lndp_ndisc, NM_TYPE_NDISC)
+
+#define NM_LNDP_NDISC_GET_PRIVATE(self) \
+    _NM_GET_PRIVATE(self, NMLndpNDisc, NM_IS_LNDP_NDISC, NMNDisc)
+
+/*****************************************************************************/
+
+static gboolean
+send_rs(NMNDisc *ndisc, GError **error)
+{
+    NMLndpNDiscPrivate *priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+    struct ndp_msg *    msg;
+    int                 errsv;
+
+    errsv = ndp_msg_new(&msg, NDP_MSG_RS);
+    if (errsv) {
+        g_set_error_literal(error,
+                            NM_UTILS_ERROR,
+                            NM_UTILS_ERROR_UNKNOWN,
+                            "cannot create router solicitation");
+        return FALSE;
+    }
+    ndp_msg_ifindex_set(msg, nm_ndisc_get_ifindex(ndisc));
+
+    errsv = ndp_msg_send(priv->ndp, msg);
+    ndp_msg_destroy(msg);
+    if (errsv) {
+        errsv = nm_errno_native(errsv);
+        g_set_error(error,
+                    NM_UTILS_ERROR,
+                    NM_UTILS_ERROR_UNKNOWN,
+                    "%s (%d)",
+                    nm_strerror_native(errsv),
+                    errsv);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+static NMIcmpv6RouterPref
+_route_preference_coerce(enum ndp_route_preference pref)
+{
+#define _ASSERT_ENUM(v1, v2)                                      \
+    G_STMT_START                                                  \
+    {                                                             \
+        G_STATIC_ASSERT((NMIcmpv6RouterPref)(v1) == (v2));        \
+        G_STATIC_ASSERT((enum ndp_route_preference)(v2) == (v1)); \
+        G_STATIC_ASSERT((gint64)(v1) == (v2));                    \
+        G_STATIC_ASSERT((gint64)(v2) == (v1));                    \
+    }                                                             \
+    G_STMT_END
+
+    switch (pref) {
+    case NDP_ROUTE_PREF_LOW:
+    case NDP_ROUTE_PREF_MEDIUM:
+    case NDP_ROUTE_PREF_HIGH:
+        _ASSERT_ENUM(NDP_ROUTE_PREF_LOW, NM_ICMPV6_ROUTER_PREF_LOW);
+        _ASSERT_ENUM(NDP_ROUTE_PREF_MEDIUM, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        _ASSERT_ENUM(NDP_ROUTE_PREF_HIGH, NM_ICMPV6_ROUTER_PREF_HIGH);
+        return (NMIcmpv6RouterPref) pref;
+    }
+
+    /* unexpected value must be treated as MEDIUM (RFC 4191). */
+    return NM_ICMPV6_ROUTER_PREF_MEDIUM;
+}
+
+static int
+receive_ra(struct ndp *ndp, struct ndp_msg *msg, gpointer user_data)
+{
+    NMNDisc *            ndisc   = (NMNDisc *) user_data;
+    NMNDiscDataInternal *rdata   = ndisc->rdata;
+    NMNDiscConfigMap     changed = 0;
+    struct ndp_msgra *   msgra   = ndp_msgra(msg);
+    struct in6_addr      gateway_addr;
+    const gint64         now_msec = nm_utils_get_monotonic_timestamp_msec();
+    int                  offset;
+    int                  hop_limit;
+    guint32              val;
+
+    /* Router discovery is subject to the following RFC documents:
+     *
+     * http://tools.ietf.org/html/rfc4861
+     * http://tools.ietf.org/html/rfc4862
+     *
+     * The biggest difference from good old DHCP is that all configuration
+     * items have their own lifetimes and they are merged from various
+     * sources. Router discovery is *not* contract-based, so there is *no*
+     * single time when the configuration is finished and updates can
+     * come at any time.
+     */
+    _LOGD("received router advertisement at timestamp %" G_GINT64_FORMAT ".%03d seconds",
+          now_msec / 1000,
+          (int) (now_msec % 1000));
+
+    gateway_addr = *ndp_msg_addrto(msg);
+    if (IN6_IS_ADDR_UNSPECIFIED(&gateway_addr))
+        g_return_val_if_reached(0);
+
+    /* DHCP level:
+     *
+     * The problem with DHCP level is what to do if subsequent
+     * router advertisements carry different flags. Currently, we just
+     * rewrite the flag with every inbound RA.
+     */
+    {
+        NMNDiscDHCPLevel dhcp_level;
+
+        if (ndp_msgra_flag_managed(msgra))
+            dhcp_level = NM_NDISC_DHCP_LEVEL_MANAGED;
+        else if (ndp_msgra_flag_other(msgra))
+            dhcp_level = NM_NDISC_DHCP_LEVEL_OTHERCONF;
+        else
+            dhcp_level = NM_NDISC_DHCP_LEVEL_NONE;
+
+        /* when receiving multiple RA (possibly from different routers),
+         * let's keep the "most managed" level. */
+        G_STATIC_ASSERT_EXPR(NM_NDISC_DHCP_LEVEL_MANAGED > NM_NDISC_DHCP_LEVEL_OTHERCONF);
+        G_STATIC_ASSERT_EXPR(NM_NDISC_DHCP_LEVEL_OTHERCONF > NM_NDISC_DHCP_LEVEL_NONE);
+        dhcp_level = MAX(dhcp_level, rdata->public.dhcp_level);
+
+        if (dhcp_level != rdata->public.dhcp_level) {
+            rdata->public.dhcp_level = dhcp_level;
+            changed |= NM_NDISC_CONFIG_DHCP_LEVEL;
+        }
+    }
+
+    /* Default gateway:
+     *
+     * Subsequent router advertisements can represent new default gateways
+     * on the network. We should present all of them in router preference
+     * order.
+     */
+    {
+        const NMNDiscGateway gateway = {
+            .address     = gateway_addr,
+            .expiry_msec = _nm_ndisc_lifetime_to_expiry(now_msec, ndp_msgra_router_lifetime(msgra)),
+            .preference  = _route_preference_coerce(ndp_msgra_route_preference(msgra)),
+        };
+
+        /* https://tools.ietf.org/html/rfc2461#section-4.2
+         *   > A Lifetime of 0 indicates that the router is not a
+         *   > default router and SHOULD NOT appear on the default
+         *   > router list.
+         * We handle that by tracking a gateway that expires right now. */
+
+        if (nm_ndisc_add_gateway(ndisc, &gateway, now_msec))
+            changed |= NM_NDISC_CONFIG_GATEWAYS;
+    }
+
+    /* Addresses & Routes */
+    ndp_msg_opt_for_each_offset (offset, msg, NDP_MSG_OPT_PREFIX) {
+        guint8          r_plen;
+        struct in6_addr r_network;
+
+        /* Device route */
+
+        r_plen = ndp_msg_opt_prefix_len(msg, offset);
+        if (r_plen == 0 || r_plen > 128)
+            continue;
+        nm_utils_ip6_address_clear_host_address(&r_network,
+                                                ndp_msg_opt_prefix(msg, offset),
+                                                r_plen);
+
+        if (IN6_IS_ADDR_UNSPECIFIED(&r_network) || IN6_IS_ADDR_LINKLOCAL(&r_network))
+            continue;
+
+        if (ndp_msg_opt_prefix_flag_on_link(msg, offset)) {
+            const NMNDiscRoute route = {
+                .network = r_network,
+                .plen    = r_plen,
+                .expiry_msec =
+                    _nm_ndisc_lifetime_to_expiry(now_msec,
+                                                 ndp_msg_opt_prefix_valid_time(msg, offset)),
+            };
+
+            if (nm_ndisc_add_route(ndisc, &route, now_msec))
+                changed |= NM_NDISC_CONFIG_ROUTES;
+        }
+
+        /* Address */
+        if (r_plen == 64 && ndp_msg_opt_prefix_flag_auto_addr_conf(msg, offset)) {
+            const guint32 valid_time = ndp_msg_opt_prefix_valid_time(msg, offset);
+            const guint32 preferred_time =
+                NM_MIN(ndp_msg_opt_prefix_preferred_time(msg, offset), valid_time);
+            const NMNDiscAddress address = {
+                .address               = r_network,
+                .expiry_msec           = _nm_ndisc_lifetime_to_expiry(now_msec, valid_time),
+                .expiry_preferred_msec = _nm_ndisc_lifetime_to_expiry(now_msec, preferred_time),
+            };
+
+            if (nm_ndisc_complete_and_add_address(ndisc, &address, now_msec))
+                changed |= NM_NDISC_CONFIG_ADDRESSES;
+        }
+    }
+    ndp_msg_opt_for_each_offset (offset, msg, NDP_MSG_OPT_ROUTE) {
+        guint8          plen = ndp_msg_opt_route_prefix_len(msg, offset);
+        struct in6_addr network;
+
+        if (plen == 0 || plen > 128)
+            continue;
+
+        nm_utils_ip6_address_clear_host_address(&network,
+                                                ndp_msg_opt_route_prefix(msg, offset),
+                                                plen);
+
+        {
+            const NMNDiscRoute route = {
+                .network = network,
+                .gateway = gateway_addr,
+                .plen    = plen,
+                .expiry_msec =
+                    _nm_ndisc_lifetime_to_expiry(now_msec, ndp_msg_opt_route_lifetime(msg, offset)),
+                .preference = _route_preference_coerce(ndp_msg_opt_route_preference(msg, offset)),
+            };
+
+            /* Routers through this particular gateway */
+            if (nm_ndisc_add_route(ndisc, &route, now_msec))
+                changed |= NM_NDISC_CONFIG_ROUTES;
+        }
+    }
+
+    ndp_msg_opt_for_each_offset (offset, msg, NDP_MSG_OPT_RDNSS) {
+        struct in6_addr *addr;
+        int              addr_index;
+
+        ndp_msg_opt_rdnss_for_each_addr (addr, addr_index, msg, offset) {
+            const NMNDiscDNSServer dns_server = {
+                .address = *addr,
+                .expiry_msec =
+                    _nm_ndisc_lifetime_to_expiry(now_msec, ndp_msg_opt_rdnss_lifetime(msg, offset)),
+            };
+
+            if (nm_ndisc_add_dns_server(ndisc, &dns_server, now_msec))
+                changed |= NM_NDISC_CONFIG_DNS_SERVERS;
+        }
+    }
+    ndp_msg_opt_for_each_offset (offset, msg, NDP_MSG_OPT_DNSSL) {
+        char *domain;
+        int   domain_index;
+
+        ndp_msg_opt_dnssl_for_each_domain (domain, domain_index, msg, offset) {
+            const NMNDiscDNSDomain dns_domain = {
+                .domain = domain,
+                .expiry_msec =
+                    _nm_ndisc_lifetime_to_expiry(now_msec, ndp_msg_opt_dnssl_lifetime(msg, offset)),
+            };
+
+            if (nm_ndisc_add_dns_domain(ndisc, &dns_domain, now_msec))
+                changed |= NM_NDISC_CONFIG_DNS_DOMAINS;
+        }
+    }
+
+    hop_limit = ndp_msgra_curhoplimit(msgra);
+    if (rdata->public.hop_limit != hop_limit) {
+        rdata->public.hop_limit = hop_limit;
+        changed |= NM_NDISC_CONFIG_HOP_LIMIT;
+    }
+
+    val = ndp_msgra_reachable_time(msgra);
+    if (val && rdata->public.reachable_time_ms != val) {
+        rdata->public.reachable_time_ms = val;
+        changed |= NM_NDISC_CONFIG_REACHABLE_TIME;
+    }
+
+    val = ndp_msgra_retransmit_time(msgra);
+    if (val && rdata->public.retrans_timer_ms != val) {
+        rdata->public.retrans_timer_ms = val;
+        changed |= NM_NDISC_CONFIG_RETRANS_TIMER;
+    }
+
+    /* MTU */
+    ndp_msg_opt_for_each_offset (offset, msg, NDP_MSG_OPT_MTU) {
+        guint32 mtu = ndp_msg_opt_mtu(msg, offset);
+        if (mtu >= 1280) {
+            if (rdata->public.mtu != mtu) {
+                rdata->public.mtu = mtu;
+                changed |= NM_NDISC_CONFIG_MTU;
+            }
+        } else {
+            /* All sorts of bad things would happen if we accepted this.
+             * Kernel would set it, but would flush out all IPv6 addresses away
+             * from the link, even the link-local, and we wouldn't be able to
+             * listen for further RAs that could fix the MTU. */
+            _LOGW("MTU too small for IPv6 ignored: %d", mtu);
+        }
+    }
+
+    nm_ndisc_ra_received(ndisc, now_msec, changed);
+    return 0;
+}
+
+static void *
+_ndp_msg_add_option(struct ndp_msg *msg, gsize len)
+{
+    gsize payload_len = ndp_msg_payload_len(msg);
+    void *ret         = &((uint8_t *) msg)[payload_len];
+
+    nm_assert(len <= G_MAXSIZE - payload_len);
+    len += payload_len;
+
+    if (len > ndp_msg_payload_maxlen(msg))
+        return NULL;
+
+    ndp_msg_payload_len_set(msg, len);
+    nm_assert(len == ndp_msg_payload_len(msg));
+    return ret;
+}
+
+/*****************************************************************************/
+
+/* "Recursive DNS Server Option" at https://tools.ietf.org/html/rfc8106#section-5.1 */
+
+#define NM_ND_OPT_RDNSS 25
+
+typedef struct _nm_packed {
+    struct nd_opt_hdr header;
+    uint16_t          reserved;
+    uint32_t          lifetime;
+    struct in6_addr   addrs[0];
+} NMLndpRdnssOption;
+
+G_STATIC_ASSERT(sizeof(NMLndpRdnssOption) == 8u);
+
+/*****************************************************************************/
+
+/* "DNS Search List Option" at https://tools.ietf.org/html/rfc8106#section-5.2 */
+
+#define NM_ND_OPT_DNSSL 31
+
+typedef struct _nm_packed {
+    struct nd_opt_hdr header;
+    uint16_t          reserved;
+    uint32_t          lifetime;
+    uint8_t           search_list[0];
+} NMLndpDnsslOption;
+
+G_STATIC_ASSERT(sizeof(NMLndpDnsslOption) == 8u);
+
+/*****************************************************************************/
+
+static gboolean
+send_ra(NMNDisc *ndisc, GError **error)
+{
+    NMLndpNDiscPrivate *     priv  = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+    NMNDiscDataInternal *    rdata = ndisc->rdata;
+    int                      errsv;
+    struct in6_addr *        addr;
+    struct ndp_msg *         msg;
+    guint                    i;
+    nm_auto_str_buf NMStrBuf sbuf = NM_STR_BUF_INIT(0, FALSE);
+
+    errsv = ndp_msg_new(&msg, NDP_MSG_RA);
+    if (errsv) {
+        g_set_error_literal(error,
+                            NM_UTILS_ERROR,
+                            NM_UTILS_ERROR_UNKNOWN,
+                            "cannot create a router advertisement");
+        return FALSE;
+    }
+
+    ndp_msg_ifindex_set(msg, nm_ndisc_get_ifindex(ndisc));
+
+    /* Multicast to all nodes. */
+    addr               = ndp_msg_addrto(msg);
+    addr->s6_addr32[0] = htonl(0xff020000);
+    addr->s6_addr32[1] = 0;
+    addr->s6_addr32[2] = 0;
+    addr->s6_addr32[3] = htonl(0x1);
+
+    ndp_msgra_router_lifetime_set(ndp_msgra(msg), NM_NDISC_ROUTER_LIFETIME);
+
+    /* The device let us know about all addresses that the device got
+     * whose prefixes are suitable for delegating. Let's announce them. */
+    for (i = 0; i < rdata->addresses->len; i++) {
+        const NMNDiscAddress *     address = &g_array_index(rdata->addresses, NMNDiscAddress, i);
+        struct nd_opt_prefix_info *prefix;
+
+        prefix = _ndp_msg_add_option(msg, sizeof(*prefix));
+        if (!prefix) {
+            /* Maybe we could sent separate RAs, but why bother... */
+            _LOGW("The RA is too big, had to omit some some prefixes.");
+            break;
+        }
+
+        prefix->nd_opt_pi_type       = ND_OPT_PREFIX_INFORMATION;
+        prefix->nd_opt_pi_len        = 4;
+        prefix->nd_opt_pi_prefix_len = 64;
+        prefix->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
+        prefix->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
+        prefix->nd_opt_pi_valid_time =
+            htonl(_nm_ndisc_lifetime_from_expiry(NM_NDISC_EXPIRY_BASE_TIMESTAMP,
+                                                 address->expiry_msec,
+                                                 TRUE));
+        prefix->nd_opt_pi_preferred_time =
+            htonl(_nm_ndisc_lifetime_from_expiry(NM_NDISC_EXPIRY_BASE_TIMESTAMP,
+                                                 address->expiry_preferred_msec,
+                                                 TRUE));
+        prefix->nd_opt_pi_prefix.s6_addr32[0] = address->address.s6_addr32[0];
+        prefix->nd_opt_pi_prefix.s6_addr32[1] = address->address.s6_addr32[1];
+        prefix->nd_opt_pi_prefix.s6_addr32[2] = 0;
+        prefix->nd_opt_pi_prefix.s6_addr32[3] = 0;
+    }
+
+    if (rdata->dns_servers->len > 0u) {
+        NMLndpRdnssOption *option;
+        gsize len = sizeof(*option) + (sizeof(option->addrs[0]) * rdata->dns_servers->len);
+
+        option = _ndp_msg_add_option(msg, len);
+        if (!option) {
+            _LOGW("The RA is too big, had to omit DNS information.");
+            goto dns_servers_done;
+        }
+
+        option->header.nd_opt_type = NM_ND_OPT_RDNSS;
+        option->header.nd_opt_len  = len / 8;
+        option->lifetime           = htonl(900);
+
+        for (i = 0; i < rdata->dns_servers->len; i++) {
+            const NMNDiscDNSServer *dns_server =
+                &g_array_index(rdata->dns_servers, NMNDiscDNSServer, i);
+
+            option->addrs[i] = dns_server->address;
+        }
+    }
+dns_servers_done:
+
+    if (rdata->dns_domains->len > 0u) {
+        NMLndpDnsslOption *option;
+        gsize              padding;
+        gsize              len;
+
+        nm_str_buf_reset(&sbuf);
+
+        for (i = 0; i < rdata->dns_domains->len; i++) {
+            const NMNDiscDNSDomain *dns_domain =
+                &g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
+            const char *domain = dns_domain->domain;
+            gsize       domain_l;
+            gsize       n_reserved;
+            int         r;
+
+            if (nm_str_is_empty(domain)) {
+                nm_assert_not_reached();
+                continue;
+            }
+
+            domain_l = strlen(domain);
+
+            nm_str_buf_maybe_expand(&sbuf, domain_l + 2u, FALSE);
+            n_reserved = sbuf.allocated - sbuf.len;
+
+            r = nm_sd_dns_name_to_wire_format(
+                domain,
+                (guint8 *) (&nm_str_buf_get_str_unsafe(&sbuf)[sbuf.len]),
+                n_reserved,
+                FALSE);
+
+            if (r < 0 || ((gsize) r) > n_reserved) {
+                nm_assert(r != -ENOBUFS);
+                nm_assert(r < 0);
+                /* we don't expect errors here, unless the domain name is invalid.
+                 * That should have been caught (and rejected) by upper layers, but
+                 * at this point it seems dangerous to assert (as it's hard to review
+                 * that all callers got it correct). So instead silently ignore the error. */
+                continue;
+            }
+
+            nm_str_buf_set_size(&sbuf, sbuf.len + ((gsize) r), TRUE, FALSE);
+        }
+
+        if (sbuf.len == 0) {
+            /* no valid domains? */
+            goto dns_domains_done;
+        }
+
+        len     = sizeof(*option) + sbuf.len;
+        padding = len % 8u;
+        if (padding != 0u) {
+            padding = 8u - padding;
+            len += padding;
+        }
+
+        nm_assert(len % 8u == 0u);
+        nm_assert(len > 0u);
+        nm_assert(len / 8u >= 2u);
+
+        if (len / 8u >= 256u || !(option = _ndp_msg_add_option(msg, len))) {
+            _LOGW("The RA is too big, had to omit DNS search list.");
+            goto dns_domains_done;
+        }
+
+        nm_str_buf_append_c_len(&sbuf, '\0', padding);
+
+        option->header.nd_opt_type = NM_ND_OPT_DNSSL;
+        option->header.nd_opt_len  = len / 8u;
+        option->reserved           = 0;
+        option->lifetime           = htonl(900);
+        memcpy(option->search_list, nm_str_buf_get_str_unsafe(&sbuf), sbuf.len);
+    }
+dns_domains_done:
+
+    errsv = ndp_msg_send(priv->ndp, msg);
+
+    ndp_msg_destroy(msg);
+    if (errsv) {
+        errsv = nm_errno_native(errsv);
+        g_set_error(error,
+                    NM_UTILS_ERROR,
+                    NM_UTILS_ERROR_UNKNOWN,
+                    "%s (%d)",
+                    nm_strerror_native(errsv),
+                    errsv);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+static int
+receive_rs(struct ndp *ndp, struct ndp_msg *msg, gpointer user_data)
+{
+    NMNDisc *ndisc = user_data;
+
+    nm_ndisc_rs_received(ndisc);
+    return 0;
+}
+
+static gboolean
+event_ready(int fd, GIOCondition condition, gpointer user_data)
+{
+    gs_unref_object NMNDisc *ndisc    = g_object_ref(NM_NDISC(user_data));
+    nm_auto_pop_netns NMPNetns *netns = NULL;
+    NMLndpNDiscPrivate *        priv  = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+
+    _LOGD("processing libndp events");
+
+    if (!nm_ndisc_netns_push(ndisc, &netns)) {
+        /* something is very wrong. Stop handling events. */
+        nm_clear_g_source_inst(&priv->event_source);
+        return G_SOURCE_REMOVE;
+    }
+
+    ndp_callall_eventfd_handler(priv->ndp);
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+start(NMNDisc *ndisc)
+{
+    NMLndpNDiscPrivate *priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+    int                 fd;
+
+    g_return_if_fail(!priv->event_source);
+
+    fd = ndp_get_eventfd(priv->ndp);
+
+    priv->event_source =
+        nm_g_unix_fd_source_new(fd, G_IO_IN, G_PRIORITY_DEFAULT, event_ready, ndisc, NULL);
+    g_source_attach(priv->event_source, NULL);
+
+    /* Flush any pending messages to avoid using obsolete information */
+    event_ready(fd, 0, ndisc);
+
+    switch (nm_ndisc_get_node_type(ndisc)) {
+    case NM_NDISC_NODE_TYPE_HOST:
+        ndp_msgrcv_handler_register(priv->ndp,
+                                    receive_ra,
+                                    NDP_MSG_RA,
+                                    nm_ndisc_get_ifindex(ndisc),
+                                    ndisc);
+        break;
+    case NM_NDISC_NODE_TYPE_ROUTER:
+        ndp_msgrcv_handler_register(priv->ndp,
+                                    receive_rs,
+                                    NDP_MSG_RS,
+                                    nm_ndisc_get_ifindex(ndisc),
+                                    ndisc);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void
+_cleanup(NMNDisc *ndisc)
+{
+    NMLndpNDiscPrivate *priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+
+    nm_clear_g_source_inst(&priv->event_source);
+
+    if (priv->ndp) {
+        switch (nm_ndisc_get_node_type(ndisc)) {
+        case NM_NDISC_NODE_TYPE_HOST:
+            ndp_msgrcv_handler_unregister(priv->ndp,
+                                          receive_ra,
+                                          NDP_MSG_RA,
+                                          nm_ndisc_get_ifindex(ndisc),
+                                          ndisc);
+            break;
+        case NM_NDISC_NODE_TYPE_ROUTER:
+            ndp_msgrcv_handler_unregister(priv->ndp,
+                                          receive_rs,
+                                          NDP_MSG_RS,
+                                          nm_ndisc_get_ifindex(ndisc),
+                                          ndisc);
+            break;
+        default:
+            nm_assert_not_reached();
+            break;
+        }
+        ndp_close(priv->ndp);
+        priv->ndp = NULL;
+    }
+}
+
+static void
+stop(NMNDisc *ndisc)
+{
+    _cleanup(ndisc);
+}
+
+/*****************************************************************************/
+
+static int
+ipv6_sysctl_get(NMPlatform *platform,
+                const char *ifname,
+                const char *property,
+                int         min,
+                int         max,
+                int         defval)
+{
+    return nm_platform_sysctl_ip_conf_get_int_checked(platform,
+                                                      AF_INET6,
+                                                      ifname,
+                                                      property,
+                                                      10,
+                                                      min,
+                                                      max,
+                                                      defval);
+}
+
+void
+nm_lndp_ndisc_get_sysctl(NMPlatform *platform,
+                         const char *ifname,
+                         int *       out_max_addresses,
+                         int *       out_router_solicitations,
+                         int *       out_router_solicitation_interval,
+                         guint32 *   out_default_ra_timeout)
+{
+    int router_solicitation_interval = 0;
+    int router_solicitations         = 0;
+
+    if (out_max_addresses) {
+        *out_max_addresses = ipv6_sysctl_get(platform,
+                                             ifname,
+                                             "max_addresses",
+                                             0,
+                                             G_MAXINT32,
+                                             NM_NDISC_MAX_ADDRESSES_DEFAULT);
+    }
+    if (out_router_solicitations || out_default_ra_timeout) {
+        router_solicitations = ipv6_sysctl_get(platform,
+                                               ifname,
+                                               "router_solicitations",
+                                               1,
+                                               G_MAXINT32,
+                                               NM_NDISC_ROUTER_SOLICITATIONS_DEFAULT);
+        NM_SET_OUT(out_router_solicitations, router_solicitations);
+    }
+    if (out_router_solicitation_interval || out_default_ra_timeout) {
+        router_solicitation_interval = ipv6_sysctl_get(platform,
+                                                       ifname,
+                                                       "router_solicitation_interval",
+                                                       1,
+                                                       G_MAXINT32,
+                                                       NM_NDISC_RFC4861_RTR_SOLICITATION_INTERVAL);
+        NM_SET_OUT(out_router_solicitation_interval, router_solicitation_interval);
+    }
+    if (out_default_ra_timeout) {
+        *out_default_ra_timeout =
+            NM_MAX((((gint64) router_solicitations) * router_solicitation_interval) + 1, 30);
+    }
+}
+
+/*****************************************************************************/
+
+static void
+nm_lndp_ndisc_init(NMLndpNDisc *lndp_ndisc)
+{}
+
+NMNDisc *
+nm_lndp_ndisc_new(NMPlatform *                  platform,
+                  int                           ifindex,
+                  const char *                  ifname,
+                  NMUtilsStableType             stable_type,
+                  const char *                  network_id,
+                  NMSettingIP6ConfigAddrGenMode addr_gen_mode,
+                  NMNDiscNodeType               node_type,
+                  int                           max_addresses,
+                  int                           router_solicitations,
+                  int                           router_solicitation_interval,
+                  guint32                       ra_timeout,
+                  GError **                     error)
+{
+    nm_auto_pop_netns NMPNetns *netns = NULL;
+    NMNDisc *                   ndisc;
+    NMLndpNDiscPrivate *        priv;
+    int                         errsv;
+
+    g_return_val_if_fail(NM_IS_PLATFORM(platform), NULL);
+    g_return_val_if_fail(!error || !*error, NULL);
+    g_return_val_if_fail(network_id, NULL);
+
+    if (!nm_platform_netns_push(platform, &netns))
+        return NULL;
+
+    ndisc = g_object_new(NM_TYPE_LNDP_NDISC,
+                         NM_NDISC_PLATFORM,
+                         platform,
+                         NM_NDISC_STABLE_TYPE,
+                         (int) stable_type,
+                         NM_NDISC_IFINDEX,
+                         ifindex,
+                         NM_NDISC_IFNAME,
+                         ifname,
+                         NM_NDISC_NETWORK_ID,
+                         network_id,
+                         NM_NDISC_ADDR_GEN_MODE,
+                         (int) addr_gen_mode,
+                         NM_NDISC_NODE_TYPE,
+                         (int) node_type,
+                         NM_NDISC_MAX_ADDRESSES,
+                         max_addresses,
+                         NM_NDISC_ROUTER_SOLICITATIONS,
+                         router_solicitations,
+                         NM_NDISC_ROUTER_SOLICITATION_INTERVAL,
+                         router_solicitation_interval,
+                         NM_NDISC_RA_TIMEOUT,
+                         (guint) ra_timeout,
+                         NULL);
+
+    priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
+
+    errsv = ndp_open(&priv->ndp);
+
+    if (errsv != 0) {
+        errsv = nm_errno_native(errsv);
+        g_set_error(error,
+                    NM_UTILS_ERROR,
+                    NM_UTILS_ERROR_UNKNOWN,
+                    "failure creating libndp socket: %s (%d)",
+                    nm_strerror_native(errsv),
+                    errsv);
+        g_object_unref(ndisc);
+        return NULL;
+    }
+    return ndisc;
+}
+
+static void
+dispose(GObject *object)
+{
+    NMNDisc *ndisc = NM_NDISC(object);
+
+    _cleanup(ndisc);
+
+    G_OBJECT_CLASS(nm_lndp_ndisc_parent_class)->dispose(object);
+}
+
+static void
+nm_lndp_ndisc_class_init(NMLndpNDiscClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS(klass);
+    NMNDiscClass *ndisc_class  = NM_NDISC_CLASS(klass);
+
+    object_class->dispose = dispose;
+    ndisc_class->start    = start;
+    ndisc_class->stop     = stop;
+    ndisc_class->send_rs  = send_rs;
+    ndisc_class->send_ra  = send_ra;
+}
diff --git a/src/core/ndisc/nm-lndp-ndisc.h b/src/core/ndisc/nm-lndp-ndisc.h
new file mode 100644
index 00000000..96fc9737
--- /dev/null
+++ b/src/core/ndisc/nm-lndp-ndisc.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_LNDP_NDISC_H__
+#define __NETWORKMANAGER_LNDP_NDISC_H__
+
+#include "nm-ndisc.h"
+#include "nm-core-utils.h"
+
+#define NM_TYPE_LNDP_NDISC (nm_lndp_ndisc_get_type())
+#define NM_LNDP_NDISC(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_LNDP_NDISC, NMLndpNDisc))
+#define NM_LNDP_NDISC_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_LNDP_NDISC, NMLndpNDiscClass))
+#define NM_IS_LNDP_NDISC(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_LNDP_NDISC))
+#define NM_IS_LNDP_NDISC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_LNDP_NDISC))
+#define NM_LNDP_NDISC_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_LNDP_NDISC, NMLndpNDiscClass))
+
+typedef struct _NMLndpNDisc      NMLndpNDisc;
+typedef struct _NMLndpNDiscClass NMLndpNDiscClass;
+
+GType nm_lndp_ndisc_get_type(void);
+
+NMNDisc *nm_lndp_ndisc_new(NMPlatform *                  platform,
+                           int                           ifindex,
+                           const char *                  ifname,
+                           NMUtilsStableType             stable_type,
+                           const char *                  network_id,
+                           NMSettingIP6ConfigAddrGenMode addr_gen_mode,
+                           NMNDiscNodeType               node_type,
+                           int                           max_addresses,
+                           int                           router_solicitations,
+                           int                           router_solicitation_interval,
+                           guint32                       ra_timeout,
+                           GError **                     error);
+
+void nm_lndp_ndisc_get_sysctl(NMPlatform *platform,
+                              const char *ifname,
+                              int *       out_max_addresses,
+                              int *       out_router_solicitations,
+                              int *       out_router_solicitation_interval,
+                              guint32 *   out_default_ra_timeout);
+
+#endif /* __NETWORKMANAGER_LNDP_NDISC_H__ */
diff --git a/src/core/ndisc/nm-ndisc-private.h b/src/core/ndisc/nm-ndisc-private.h
new file mode 100644
index 00000000..04739124
--- /dev/null
+++ b/src/core/ndisc/nm-ndisc-private.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_NDISC_PRIVATE_H__
+#define __NETWORKMANAGER_NDISC_PRIVATE_H__
+
+#include "nm-ndisc.h"
+
+/* Functions only used by ndisc implementations */
+
+struct _NMNDiscDataInternal {
+    NMNDiscData public;
+    GArray *gateways;
+    GArray *addresses;
+    GArray *routes;
+    GArray *dns_servers;
+    GArray *dns_domains;
+};
+
+typedef struct _NMNDiscDataInternal NMNDiscDataInternal;
+
+void nm_ndisc_ra_received(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap changed);
+void nm_ndisc_rs_received(NMNDisc *ndisc);
+
+gboolean nm_ndisc_add_gateway(NMNDisc *ndisc, const NMNDiscGateway *new_item, gint64 now_msec);
+gboolean
+nm_ndisc_complete_and_add_address(NMNDisc *ndisc, const NMNDiscAddress *new_item, gint64 now_msec);
+gboolean nm_ndisc_add_route(NMNDisc *ndisc, const NMNDiscRoute *new_item, gint64 now_msec);
+gboolean nm_ndisc_add_dns_server(NMNDisc *ndisc, const NMNDiscDNSServer *new_item, gint64 now_msec);
+gboolean nm_ndisc_add_dns_domain(NMNDisc *ndisc, const NMNDiscDNSDomain *new_item, gint64 now_msec);
+
+/*****************************************************************************/
+
+#define _NMLOG_DOMAIN      LOGD_IP6
+#define _NMLOG(level, ...) _LOG(level, _NMLOG_DOMAIN, ndisc, __VA_ARGS__)
+
+#define _LOG(level, domain, self, ...)                                                \
+    G_STMT_START                                                                      \
+    {                                                                                 \
+        const NMLogLevel  __level  = (level);                                         \
+        const NMLogDomain __domain = (domain);                                        \
+                                                                                      \
+        if (nm_logging_enabled(__level, __domain)) {                                  \
+            NMNDisc *const __self = (self);                                           \
+            char           __prefix[64];                                              \
+            const char *   __ifname = __self ? nm_ndisc_get_ifname(__self) : NULL;    \
+                                                                                      \
+            _nm_log(__level,                                                          \
+                    __domain,                                                         \
+                    0,                                                                \
+                    __ifname,                                                         \
+                    NULL,                                                             \
+                    "%s: " _NM_UTILS_MACRO_FIRST(__VA_ARGS__),                        \
+                    (__self ? nm_sprintf_buf(__prefix,                                \
+                                             "%s[%p,%s%s%s]",                         \
+                                             _NMLOG_PREFIX_NAME,                      \
+                                             __self,                                  \
+                                             NM_PRINT_FMT_QUOTE_STRING(__ifname))     \
+                            : _NMLOG_PREFIX_NAME) _NM_UTILS_MACRO_REST(__VA_ARGS__)); \
+        }                                                                             \
+    }                                                                                 \
+    G_STMT_END
+
+/*****************************************************************************/
+
+#endif /* __NETWORKMANAGER_NDISC_PRIVATE_H__ */
diff --git a/src/core/ndisc/nm-ndisc.c b/src/core/ndisc/nm-ndisc.c
new file mode 100644
index 00000000..a5c1b935
--- /dev/null
+++ b/src/core/ndisc/nm-ndisc.c
@@ -0,0 +1,1830 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-ndisc.h"
+
+#include <stdlib.h>
+#include <arpa/inet.h>
+
+#include "nm-setting-ip6-config.h"
+
+#include "nm-ndisc-private.h"
+#include "nm-utils.h"
+#include "platform/nm-platform.h"
+#include "nm-platform/nmp-netns.h"
+#include "nm-l3-config-data.h"
+
+#define _NMLOG_PREFIX_NAME "ndisc"
+
+#define RFC7559_IRT ((gint32) 4)    /* RFC7559, Initial Retransmission Time, in seconds */
+#define RFC7559_MRT ((gint32) 3600) /* RFC7559, Maximum Retransmission Time, in seconds */
+
+#define _SIZE_MAX_GATEWAYS    100u
+#define _SIZE_MAX_ADDRESSES   100u
+#define _SIZE_MAX_ROUTES      1000u
+#define _SIZE_MAX_DNS_SERVERS 64u
+#define _SIZE_MAX_DNS_DOMAINS 64u
+
+/*****************************************************************************/
+
+struct _NMNDiscPrivate {
+    /* this *must* be the first field. */
+    NMNDiscDataInternal rdata;
+
+    char *last_error;
+
+    GSource *ra_timeout_source;
+
+    gint32 announcements_left;
+    guint  send_ra_id;
+    gint32 last_ra;
+
+    gint32 solicit_retransmit_time_msec;
+
+    GSource *solicit_timer_source;
+
+    GSource *timeout_expire_source;
+
+    NMUtilsIPv6IfaceId iid;
+
+    /* immutable values: */
+    int                           ifindex;
+    char *                        ifname;
+    char *                        network_id;
+    guint                         max_addresses;
+    NMSettingIP6ConfigAddrGenMode addr_gen_mode;
+    NMUtilsStableType             stable_type;
+    guint32                       ra_timeout;
+    gint32                        router_solicitations;
+    gint32                        router_solicitation_interval;
+    NMNDiscNodeType               node_type;
+
+    NMPlatform *platform;
+    NMPNetns *  netns;
+};
+
+typedef struct _NMNDiscPrivate NMNDiscPrivate;
+
+NM_GOBJECT_PROPERTIES_DEFINE_BASE(PROP_PLATFORM,
+                                  PROP_IFINDEX,
+                                  PROP_IFNAME,
+                                  PROP_STABLE_TYPE,
+                                  PROP_NETWORK_ID,
+                                  PROP_ADDR_GEN_MODE,
+                                  PROP_MAX_ADDRESSES,
+                                  PROP_RA_TIMEOUT,
+                                  PROP_ROUTER_SOLICITATIONS,
+                                  PROP_ROUTER_SOLICITATION_INTERVAL,
+                                  PROP_NODE_TYPE, );
+
+enum { CONFIG_RECEIVED, RA_TIMEOUT_SIGNAL, LAST_SIGNAL };
+
+static guint signals[LAST_SIGNAL] = {0};
+
+G_DEFINE_TYPE(NMNDisc, nm_ndisc, G_TYPE_OBJECT)
+
+#define NM_NDISC_GET_PRIVATE(self) _NM_GET_PRIVATE_PTR(self, NMNDisc, NM_IS_NDISC)
+
+/*****************************************************************************/
+
+static void     _config_changed_log(NMNDisc *ndisc, NMNDiscConfigMap changed);
+static gboolean timeout_expire_cb(gpointer user_data);
+
+/*****************************************************************************/
+
+NML3ConfigData *
+nm_ndisc_data_to_l3cd(NMDedupMultiIndex *       multi_idx,
+                      int                       ifindex,
+                      const NMNDiscData *       rdata,
+                      NMSettingIP6ConfigPrivacy ip6_privacy,
+                      guint32                   route_table,
+                      guint32                   route_metric,
+                      gboolean                  kernel_support_rta_pref,
+                      gboolean                  kernel_support_extended_ifa_flags)
+{
+    nm_auto_unref_l3cd_init NML3ConfigData *l3cd = NULL;
+    guint32                                 ifa_flags;
+    guint8                                  plen;
+    guint                                   i;
+    const gint32                            now_sec = nm_utils_get_monotonic_timestamp_sec();
+
+    l3cd = nm_l3_config_data_new(multi_idx, ifindex);
+
+    nm_l3_config_data_set_source(l3cd, NM_IP_CONFIG_SOURCE_NDISC);
+
+    nm_l3_config_data_set_ip6_privacy(l3cd, ip6_privacy);
+
+    /* Check, whether kernel is recent enough to help user space handling RA.
+     * If it's not supported, we have no ipv6-privacy and must add autoconf
+     * addresses as /128. The reason for the /128 is to prevent the kernel
+     * from adding a prefix route for this address. */
+    ifa_flags = 0;
+    if (kernel_support_extended_ifa_flags) {
+        ifa_flags |= IFA_F_NOPREFIXROUTE;
+        if (NM_IN_SET(ip6_privacy,
+                      NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_TEMP_ADDR,
+                      NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_PUBLIC_ADDR))
+            ifa_flags |= IFA_F_MANAGETEMPADDR;
+        plen = 64;
+    } else
+        plen = 128;
+
+    for (i = 0; i < rdata->addresses_n; i++) {
+        const NMNDiscAddress *ndisc_addr = &rdata->addresses[i];
+        NMPlatformIP6Address  a;
+
+        a = (NMPlatformIP6Address){
+            .ifindex   = ifindex,
+            .address   = ndisc_addr->address,
+            .plen      = plen,
+            .timestamp = now_sec,
+            .lifetime  = _nm_ndisc_lifetime_from_expiry(((gint64) now_sec) * 1000,
+                                                       ndisc_addr->expiry_msec,
+                                                       TRUE),
+            .preferred = _nm_ndisc_lifetime_from_expiry(
+                ((gint64) now_sec) * 1000,
+                NM_MIN(ndisc_addr->expiry_msec, ndisc_addr->expiry_preferred_msec),
+                TRUE),
+            .addr_source = NM_IP_CONFIG_SOURCE_NDISC,
+            .n_ifa_flags = ifa_flags,
+        };
+
+        nm_l3_config_data_add_address_6(l3cd, &a);
+    }
+
+    for (i = 0; i < rdata->routes_n; i++) {
+        const NMNDiscRoute *ndisc_route = &rdata->routes[i];
+        NMPlatformIP6Route  r;
+
+        r = (NMPlatformIP6Route){
+            .ifindex       = ifindex,
+            .network       = ndisc_route->network,
+            .plen          = ndisc_route->plen,
+            .gateway       = ndisc_route->gateway,
+            .rt_source     = NM_IP_CONFIG_SOURCE_NDISC,
+            .table_coerced = nm_platform_route_table_coerce(route_table),
+            .metric        = route_metric,
+            .rt_pref       = ndisc_route->preference,
+        };
+        nm_assert((NMIcmpv6RouterPref) r.rt_pref == ndisc_route->preference);
+
+        nm_l3_config_data_add_route_6(l3cd, &r);
+    }
+
+    if (rdata->gateways_n > 0) {
+        const NMIcmpv6RouterPref first_pref = rdata->gateways[0].preference;
+        NMPlatformIP6Route       r          = {
+            .rt_source     = NM_IP_CONFIG_SOURCE_NDISC,
+            .ifindex       = ifindex,
+            .table_coerced = nm_platform_route_table_coerce(route_table),
+            .metric        = route_metric,
+        };
+
+        for (i = 0; i < rdata->gateways_n; i++) {
+            r.gateway = rdata->gateways[i].address;
+            r.rt_pref = rdata->gateways[i].preference;
+            nm_assert((NMIcmpv6RouterPref) r.rt_pref == rdata->gateways[i].preference);
+            nm_l3_config_data_add_route_6(l3cd, &r);
+
+            if (first_pref != rdata->gateways[i].preference && !kernel_support_rta_pref) {
+                /* We are unable to configure a router preference. Hence, we skip all gateways
+                 * with a different preference from the first gateway. Note, that the gateways
+                 * are sorted in order of highest to lowest preference. */
+                break;
+            }
+        }
+    }
+
+    for (i = 0; i < rdata->dns_servers_n; i++)
+        nm_l3_config_data_add_nameserver(l3cd, AF_INET6, &rdata->dns_servers[i].address);
+
+    for (i = 0; i < rdata->dns_domains_n; i++)
+        nm_l3_config_data_add_search(l3cd, AF_INET6, rdata->dns_domains[i].domain);
+
+    nm_l3_config_data_set_ndisc_hop_limit(l3cd, rdata->hop_limit);
+    nm_l3_config_data_set_ndisc_reachable_time_msec(l3cd, rdata->reachable_time_ms);
+    nm_l3_config_data_set_ndisc_retrans_timer_msec(l3cd, rdata->retrans_timer_ms);
+
+    nm_l3_config_data_set_ip6_mtu(l3cd, rdata->mtu);
+
+    return g_steal_pointer(&l3cd);
+}
+
+/*****************************************************************************/
+
+static guint8
+_preference_to_priority(NMIcmpv6RouterPref pref)
+{
+    switch (pref) {
+    case NM_ICMPV6_ROUTER_PREF_LOW:
+        return 1;
+    case NM_ICMPV6_ROUTER_PREF_MEDIUM:
+        return 2;
+    case NM_ICMPV6_ROUTER_PREF_HIGH:
+        return 3;
+    case NM_ICMPV6_ROUTER_PREF_INVALID:
+        break;
+    }
+    return 0;
+}
+
+/*****************************************************************************/
+
+static gboolean
+expiry_next(gint64 now_msec, gint64 expiry_msec, gint64 *next_msec)
+{
+    if (expiry_msec == NM_NDISC_EXPIRY_INFINITY)
+        return TRUE;
+
+    if (expiry_msec <= now_msec) {
+        /* expired. */
+        return FALSE;
+    }
+
+    if (next_msec) {
+        if (*next_msec > expiry_msec)
+            *next_msec = expiry_msec;
+    }
+
+    /* the timestamp is good (not yet expired) */
+    return TRUE;
+}
+
+static const char *
+_get_exp(char *buf, gsize buf_size, gint64 now_msec, gint64 expiry_time)
+{
+    int l;
+
+    if (expiry_time == NM_NDISC_EXPIRY_INFINITY)
+        return "permanent";
+    l = g_snprintf(buf, buf_size, "%.3f", ((double) (expiry_time - now_msec)) / 1000);
+    nm_assert(l < buf_size);
+    return buf;
+}
+
+#define get_exp(buf, now_msec, item) \
+    _get_exp((buf), G_N_ELEMENTS(buf), (now_msec), (item)->expiry_msec)
+
+/*****************************************************************************/
+
+NMPNetns *
+nm_ndisc_netns_get(NMNDisc *self)
+{
+    g_return_val_if_fail(NM_IS_NDISC(self), NULL);
+
+    return NM_NDISC_GET_PRIVATE(self)->netns;
+}
+
+gboolean
+nm_ndisc_netns_push(NMNDisc *self, NMPNetns **netns)
+{
+    NMNDiscPrivate *priv;
+
+    g_return_val_if_fail(NM_IS_NDISC(self), FALSE);
+
+    priv = NM_NDISC_GET_PRIVATE(self);
+    if (priv->netns && !nmp_netns_push(priv->netns)) {
+        NM_SET_OUT(netns, NULL);
+        return FALSE;
+    }
+
+    NM_SET_OUT(netns, priv->netns);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+int
+nm_ndisc_get_ifindex(NMNDisc *self)
+{
+    g_return_val_if_fail(NM_IS_NDISC(self), 0);
+
+    return NM_NDISC_GET_PRIVATE(self)->ifindex;
+}
+
+const char *
+nm_ndisc_get_ifname(NMNDisc *self)
+{
+    g_return_val_if_fail(NM_IS_NDISC(self), NULL);
+
+    return NM_NDISC_GET_PRIVATE(self)->ifname;
+}
+
+NMNDiscNodeType
+nm_ndisc_get_node_type(NMNDisc *self)
+{
+    g_return_val_if_fail(NM_IS_NDISC(self), NM_NDISC_NODE_TYPE_INVALID);
+
+    return NM_NDISC_GET_PRIVATE(self)->node_type;
+}
+
+/*****************************************************************************/
+
+static void
+_ASSERT_data_gateways(const NMNDiscDataInternal *data)
+{
+#if NM_MORE_ASSERTS > 10
+    guint                 i, j;
+    const NMNDiscGateway *item_prev = NULL;
+
+    if (!data->gateways->len)
+        return;
+
+    for (i = 0; i < data->gateways->len; i++) {
+        const NMNDiscGateway *item = &g_array_index(data->gateways, NMNDiscGateway, i);
+
+        nm_assert(!IN6_IS_ADDR_UNSPECIFIED(&item->address));
+        for (j = 0; j < i; j++) {
+            const NMNDiscGateway *item2 = &g_array_index(data->gateways, NMNDiscGateway, j);
+
+            nm_assert(!IN6_ARE_ADDR_EQUAL(&item->address, &item2->address));
+        }
+
+        if (i > 0) {
+            nm_assert(_preference_to_priority(item_prev->preference)
+                      >= _preference_to_priority(item->preference));
+        }
+
+        item_prev = item;
+    }
+#endif
+}
+
+/*****************************************************************************/
+
+static const NMNDiscData *
+_data_complete(NMNDiscDataInternal *data)
+{
+    _ASSERT_data_gateways(data);
+
+#define _SET(data, field)                                      \
+    G_STMT_START                                               \
+    {                                                          \
+        if ((data->public.field##_n = data->field->len) > 0)   \
+            data->public.field = (gpointer) data->field->data; \
+        else                                                   \
+            data->public.field = NULL;                         \
+    }                                                          \
+    G_STMT_END
+    _SET(data, gateways);
+    _SET(data, addresses);
+    _SET(data, routes);
+    _SET(data, dns_servers);
+    _SET(data, dns_domains);
+#undef _SET
+    return &data->public;
+}
+
+void
+nm_ndisc_emit_config_change(NMNDisc *self, NMNDiscConfigMap changed)
+{
+    _config_changed_log(self, changed);
+    g_signal_emit(self,
+                  signals[CONFIG_RECEIVED],
+                  0,
+                  _data_complete(&NM_NDISC_GET_PRIVATE(self)->rdata),
+                  (guint) changed);
+}
+
+/*****************************************************************************/
+
+gboolean
+nm_ndisc_add_gateway(NMNDisc *ndisc, const NMNDiscGateway *new_item, gint64 now_msec)
+{
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    guint                i;
+    guint                insert_idx = G_MAXUINT;
+
+    for (i = 0; i < rdata->gateways->len;) {
+        NMNDiscGateway *item = &g_array_index(rdata->gateways, NMNDiscGateway, i);
+
+        if (IN6_ARE_ADDR_EQUAL(&item->address, &new_item->address)) {
+            if (new_item->expiry_msec <= now_msec) {
+                g_array_remove_index(rdata->gateways, i);
+                _ASSERT_data_gateways(rdata);
+                return TRUE;
+            }
+
+            if (item->preference != new_item->preference) {
+                g_array_remove_index(rdata->gateways, i);
+                continue;
+            }
+
+            if (item->expiry_msec == new_item->expiry_msec)
+                return FALSE;
+
+            item->expiry_msec = new_item->expiry_msec;
+            _ASSERT_data_gateways(rdata);
+            return TRUE;
+        }
+
+        /* Put before less preferable gateways. */
+        if (_preference_to_priority(item->preference)
+                < _preference_to_priority(new_item->preference)
+            && insert_idx == G_MAXUINT)
+            insert_idx = i;
+
+        i++;
+    }
+
+    if (rdata->gateways->len >= _SIZE_MAX_GATEWAYS)
+        return FALSE;
+
+    if (new_item->expiry_msec <= now_msec)
+        return FALSE;
+
+    g_array_insert_val(rdata->gateways,
+                       insert_idx == G_MAXUINT ? rdata->gateways->len : insert_idx,
+                       *new_item);
+    _ASSERT_data_gateways(rdata);
+    return TRUE;
+}
+
+/**
+ * complete_address:
+ * @ndisc: the #NMNDisc
+ * @addr: the #NMNDiscAddress
+ *
+ * Adds the host part to the address that has network part set.
+ * If the address already has a host part, add a different host part
+ * if possible (this is useful in case DAD failed).
+ *
+ * Can fail if a different address can not be generated (DAD failure
+ * for an EUI-64 address or DAD counter overflow).
+ *
+ * Returns: %TRUE if the address could be completed, %FALSE otherwise.
+ **/
+static gboolean
+complete_address(NMNDisc *ndisc, NMNDiscAddress *addr)
+{
+    NMNDiscPrivate *priv;
+    GError *        error = NULL;
+
+    g_return_val_if_fail(NM_IS_NDISC(ndisc), FALSE);
+
+    priv = NM_NDISC_GET_PRIVATE(ndisc);
+    if (priv->addr_gen_mode == NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_STABLE_PRIVACY) {
+        if (!nm_utils_ipv6_addr_set_stable_privacy(priv->stable_type,
+                                                   &addr->address,
+                                                   priv->ifname,
+                                                   priv->network_id,
+                                                   addr->dad_counter++,
+                                                   &error)) {
+            _LOGW("complete-address: failed to generate an stable-privacy address: %s",
+                  error->message);
+            g_clear_error(&error);
+            return FALSE;
+        }
+        _LOGD("complete-address: using an stable-privacy address");
+        return TRUE;
+    }
+
+    if (!priv->iid.id) {
+        _LOGW("complete-address: can't generate an EUI-64 address: no interface identifier");
+        return FALSE;
+    }
+
+    if (addr->address.s6_addr32[2] == 0x0 && addr->address.s6_addr32[3] == 0x0) {
+        _LOGD("complete-address: adding an EUI-64 address");
+        nm_utils_ipv6_addr_set_interface_identifier(&addr->address, priv->iid);
+        return TRUE;
+    }
+
+    _LOGW("complete-address: can't generate a new_item EUI-64 address");
+    return FALSE;
+}
+
+static gboolean
+nm_ndisc_add_address(NMNDisc *             ndisc,
+                     const NMNDiscAddress *new_item,
+                     gint64                now_msec,
+                     gboolean              from_ra)
+{
+    NMNDiscPrivate *     priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    NMNDiscDataInternal *rdata = &priv->rdata;
+    NMNDiscAddress *     new2;
+    NMNDiscAddress *     existing = NULL;
+    guint                i;
+
+    nm_assert(new_item);
+    nm_assert(!IN6_IS_ADDR_UNSPECIFIED(&new_item->address));
+    nm_assert(!IN6_IS_ADDR_LINKLOCAL(&new_item->address));
+    nm_assert(new_item->expiry_preferred_msec <= new_item->expiry_msec);
+    nm_assert((!!from_ra) == (now_msec > 0));
+
+    for (i = 0; i < rdata->addresses->len; i++) {
+        NMNDiscAddress *item = &g_array_index(rdata->addresses, NMNDiscAddress, i);
+
+        if (from_ra) {
+            /* RFC4862 5.5.3.d, we find an existing address with the same prefix.
+             * (note that all prefixes at this point have implicitly length /64). */
+            if (memcmp(&item->address, &new_item->address, 8) == 0) {
+                existing = item;
+                break;
+            }
+        } else {
+            if (IN6_ARE_ADDR_EQUAL(&item->address, &new_item->address)) {
+                existing = item;
+                break;
+            }
+        }
+    }
+
+    if (existing) {
+        gint64 new_expiry_preferred_msec;
+        gint64 new_expiry_msec;
+
+        if (from_ra) {
+            if (new_item->expiry_msec == NM_NDISC_EXPIRY_INFINITY)
+                new_expiry_msec = NM_NDISC_EXPIRY_INFINITY;
+            else {
+                const gint64 NDISC_PREFIX_LFT_MIN_MSEC = 7200 * 1000; /* RFC4862 5.5.3.e */
+                gint64       new_lifetime;
+                gint64       existing_lifetime;
+
+                new_lifetime = new_item->expiry_msec - now_msec;
+                if (existing->expiry_msec == NM_NDISC_EXPIRY_INFINITY)
+                    existing_lifetime = G_MAXINT64;
+                else
+                    existing_lifetime = existing->expiry_msec - now_msec;
+
+                /* see RFC4862 5.5.3.e */
+                if (new_lifetime >= NDISC_PREFIX_LFT_MIN_MSEC
+                    || new_lifetime >= existing_lifetime) {
+                    /* either extend the lifetime of the new_item lifetime is longer than
+                     * NDISC_PREFIX_LFT_MIN_MSEC. */
+                    new_expiry_msec = new_item->expiry_msec;
+                } else if (existing_lifetime <= NDISC_PREFIX_LFT_MIN_MSEC) {
+                    /* keep the current lifetime. */
+                    new_expiry_msec = existing->expiry_msec;
+                } else {
+                    /* trim the current lifetime to NDISC_PREFIX_LFT_MIN_MSEC. */
+                    new_expiry_msec = now_msec + NDISC_PREFIX_LFT_MIN_MSEC;
+                }
+            }
+
+            new_expiry_preferred_msec =
+                NM_MIN(new_item->expiry_preferred_msec, new_item->expiry_msec);
+            new_expiry_preferred_msec = NM_MIN(new_expiry_preferred_msec, new_expiry_msec);
+        } else {
+            if (new_item->expiry_msec <= now_msec) {
+                g_array_remove_index(rdata->addresses, i);
+                return TRUE;
+            }
+
+            new_expiry_msec = new_item->expiry_msec;
+            new_expiry_preferred_msec =
+                NM_MIN(new_item->expiry_preferred_msec, new_item->expiry_msec);
+        }
+
+        /* the dad_counter does not get modified. */
+        if (new_expiry_msec == existing->expiry_msec
+            && new_expiry_preferred_msec == existing->expiry_preferred_msec) {
+            return FALSE;
+        }
+
+        existing->expiry_msec           = new_expiry_msec;
+        existing->expiry_preferred_msec = new_expiry_preferred_msec;
+        return TRUE;
+    }
+
+    /* we create at most max_addresses autoconf addresses. This is different from
+     * what the kernel does, because it considers *all* addresses (including
+     * static and other temporary addresses).
+     **/
+    if (rdata->addresses->len >= priv->max_addresses)
+        return FALSE;
+
+    if (new_item->expiry_msec <= now_msec)
+        return FALSE;
+
+    new2 = nm_g_array_append_new(rdata->addresses, NMNDiscAddress);
+
+    *new2 = *new_item;
+
+    new2->expiry_preferred_msec = NM_MIN(new2->expiry_preferred_msec, new2->expiry_msec);
+
+    if (from_ra) {
+        new2->dad_counter = 0;
+        if (!complete_address(ndisc, new2)) {
+            g_array_set_size(rdata->addresses, rdata->addresses->len - 1);
+            return FALSE;
+        }
+    }
+
+    return TRUE;
+}
+
+gboolean
+nm_ndisc_complete_and_add_address(NMNDisc *ndisc, const NMNDiscAddress *new_item, gint64 now_msec)
+{
+    return nm_ndisc_add_address(ndisc, new_item, now_msec, TRUE);
+}
+
+gboolean
+nm_ndisc_add_route(NMNDisc *ndisc, const NMNDiscRoute *new_item, gint64 now_msec)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+    guint                i;
+    guint                insert_idx = G_MAXUINT;
+    gboolean             changed    = FALSE;
+
+    if (new_item->plen == 0 || new_item->plen > 128) {
+        /* Only expect non-default routes.  The router has no idea what the
+         * local configuration or user preferences are, so sending routes
+         * with a prefix length of 0 must be ignored by NMNDisc.
+         *
+         * Also, upper layers also don't expect that NMNDisc exposes routes
+         * with a plen or zero or larger then 128.
+         */
+        g_return_val_if_reached(FALSE);
+    }
+
+    priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    rdata = &priv->rdata;
+
+    for (i = 0; i < rdata->routes->len;) {
+        NMNDiscRoute *item = &g_array_index(rdata->routes, NMNDiscRoute, i);
+
+        if (IN6_ARE_ADDR_EQUAL(&item->network, &new_item->network)
+            && item->plen == new_item->plen) {
+            if (new_item->expiry_msec <= now_msec) {
+                g_array_remove_index(rdata->routes, i);
+                return TRUE;
+            }
+
+            if (item->preference != new_item->preference) {
+                g_array_remove_index(rdata->routes, i);
+                changed = TRUE;
+                continue;
+            }
+
+            if (item->expiry_msec == new_item->expiry_msec
+                && IN6_ARE_ADDR_EQUAL(&item->gateway, &new_item->gateway))
+                return FALSE;
+
+            item->expiry_msec = new_item->expiry_msec;
+            item->gateway     = new_item->gateway;
+            return TRUE;
+        }
+
+        /* Put before less preferable routes. */
+        if (_preference_to_priority(item->preference)
+                < _preference_to_priority(new_item->preference)
+            && insert_idx == G_MAXUINT)
+            insert_idx = i;
+
+        i++;
+    }
+
+    if (rdata->routes->len >= _SIZE_MAX_ROUTES)
+        return FALSE;
+
+    if (new_item->expiry_msec <= now_msec) {
+        nm_assert(!changed);
+        return FALSE;
+    }
+
+    g_array_insert_val(rdata->routes, insert_idx == G_MAXUINT ? 0u : insert_idx, *new_item);
+    return TRUE;
+}
+
+gboolean
+nm_ndisc_add_dns_server(NMNDisc *ndisc, const NMNDiscDNSServer *new_item, gint64 now_msec)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+    guint                i;
+
+    priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    rdata = &priv->rdata;
+
+    for (i = 0; i < rdata->dns_servers->len; i++) {
+        NMNDiscDNSServer *item = &g_array_index(rdata->dns_servers, NMNDiscDNSServer, i);
+
+        if (IN6_ARE_ADDR_EQUAL(&item->address, &new_item->address)) {
+            if (new_item->expiry_msec <= now_msec) {
+                g_array_remove_index(rdata->dns_servers, i);
+                return TRUE;
+            }
+
+            if (item->expiry_msec == new_item->expiry_msec)
+                return FALSE;
+
+            item->expiry_msec = new_item->expiry_msec;
+            return TRUE;
+        }
+    }
+
+    if (rdata->dns_servers->len >= _SIZE_MAX_DNS_SERVERS)
+        return FALSE;
+
+    if (new_item->expiry_msec <= now_msec)
+        return FALSE;
+
+    g_array_append_val(rdata->dns_servers, *new_item);
+    return TRUE;
+}
+
+/* Copies new_item->domain if 'new_item' is added to the dns_domains list */
+gboolean
+nm_ndisc_add_dns_domain(NMNDisc *ndisc, const NMNDiscDNSDomain *new_item, gint64 now_msec)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+    NMNDiscDNSDomain *   item;
+    guint                i;
+
+    priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    rdata = &priv->rdata;
+
+    for (i = 0; i < rdata->dns_domains->len; i++) {
+        item = &g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
+
+        if (nm_streq(item->domain, new_item->domain)) {
+            if (new_item->expiry_msec <= now_msec) {
+                g_array_remove_index(rdata->dns_domains, i);
+                return TRUE;
+            }
+
+            if (item->expiry_msec == new_item->expiry_msec)
+                return FALSE;
+
+            item->expiry_msec = new_item->expiry_msec;
+            return TRUE;
+        }
+    }
+
+    if (rdata->dns_domains->len >= _SIZE_MAX_DNS_DOMAINS)
+        return FALSE;
+
+    if (new_item->expiry_msec <= now_msec)
+        return FALSE;
+
+    item  = nm_g_array_append_new(rdata->dns_domains, NMNDiscDNSDomain);
+    *item = (NMNDiscDNSDomain){
+        .domain      = g_strdup(new_item->domain),
+        .expiry_msec = new_item->expiry_msec,
+    };
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+#define _MAYBE_WARN(...)                                                   \
+    G_STMT_START                                                           \
+    {                                                                      \
+        gboolean _different_message;                                       \
+                                                                           \
+        _different_message = !nm_streq0(priv->last_error, error->message); \
+        _NMLOG(_different_message ? LOGL_WARN : LOGL_DEBUG, __VA_ARGS__);  \
+        if (_different_message) {                                          \
+            nm_clear_g_free(&priv->last_error);                            \
+            priv->last_error = g_strdup(error->message);                   \
+        }                                                                  \
+    }                                                                      \
+    G_STMT_END
+
+static gint32
+solicit_retransmit_time_jitter(gint32 solicit_retransmit_time_msec)
+{
+    gint32 ten_percent;
+
+    nm_assert(solicit_retransmit_time_msec > 0);
+    nm_assert(solicit_retransmit_time_msec < 3 * RFC7559_MRT * 1000);
+
+    /* Add a ±10% jitter.
+     *
+     * This is the "RAND" parameter from https://tools.ietf.org/html/rfc3315#section-14
+     * as requested by RFC7559.  */
+
+    ten_percent = NM_MAX(1, solicit_retransmit_time_msec / 10);
+
+    return solicit_retransmit_time_msec - ten_percent
+           + ((gint32)(g_random_int() % (2u * ((guint32) ten_percent))));
+}
+
+static gboolean
+solicit_timer_cb(gpointer user_data)
+{
+    const gint32      TIMEOUT_APPROX_THRESHOLD_SEC = 10000;
+    nm_auto_pop_netns NMPNetns *netns              = NULL;
+    NMNDisc *                   ndisc              = user_data;
+    NMNDiscClass *              klass              = NM_NDISC_GET_CLASS(ndisc);
+    NMNDiscPrivate *            priv               = NM_NDISC_GET_PRIVATE(ndisc);
+    gs_free_error GError *error                    = NULL;
+    gint32                timeout_msec;
+
+    if (!nm_ndisc_netns_push(ndisc, &netns)) {
+        nm_utils_error_set(&error,
+                           NM_UTILS_ERROR_UNKNOWN,
+                           "failure to switch netns for soliciting routers");
+    } else
+        klass->send_rs(ndisc, &error);
+
+    if (error)
+        _MAYBE_WARN("solicit: failure sending router solicitation: %s", error->message);
+    else {
+        _LOGT("solicit: router solicitation sent");
+        nm_clear_g_free(&priv->last_error);
+    }
+
+    /* https://tools.ietf.org/html/rfc4861#section-6.3.7 describes how to send solicitations:
+     *
+     *   > ... a host SHOULD transmit up to MAX_RTR_SOLICITATIONS Router Solicitation messages,
+     *   > each separated by at least RTR_SOLICITATION_INTERVAL seconds.
+     *
+     * but this was extended by https://tools.ietf.org/html/rfc7559#section-2 to send continuously
+     * and with exponential backoff (detailed the algorithm in https://tools.ietf.org/html/rfc3315#section-14).
+     * We do RFC7559.
+     */
+    if (priv->solicit_retransmit_time_msec == 0) {
+        G_STATIC_ASSERT(RFC7559_IRT == NM_NDISC_RFC4861_RTR_SOLICITATION_INTERVAL);
+        priv->solicit_retransmit_time_msec = solicit_retransmit_time_jitter(RFC7559_IRT * 1000);
+        timeout_msec                       = priv->solicit_retransmit_time_msec;
+    } else {
+        priv->solicit_retransmit_time_msec +=
+            solicit_retransmit_time_jitter(priv->solicit_retransmit_time_msec);
+        timeout_msec = priv->solicit_retransmit_time_msec;
+        if (priv->solicit_retransmit_time_msec > RFC7559_MRT * 1000) {
+            priv->solicit_retransmit_time_msec = RFC7559_MRT * 1000;
+            timeout_msec = solicit_retransmit_time_jitter(priv->solicit_retransmit_time_msec);
+        }
+    }
+
+    _LOGD("solicit: schedule sending next solicitation in%s %.3f seconds",
+          timeout_msec / 1000 >= TIMEOUT_APPROX_THRESHOLD_SEC ? " about" : "",
+          ((double) timeout_msec) / 1000);
+
+    nm_clear_g_source_inst(&priv->solicit_timer_source);
+    priv->solicit_timer_source = nm_g_timeout_add_source_approx(timeout_msec,
+                                                                TIMEOUT_APPROX_THRESHOLD_SEC,
+                                                                solicit_timer_cb,
+                                                                ndisc);
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+solicit_timer_start(NMNDisc *ndisc)
+{
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(ndisc);
+    gint32          delay_msec;
+
+    /* rfc4861, Section 6.3.7:
+     *
+     * We should randomly wait up to NM_NDISC_RFC4861_MAX_RTR_SOLICITATION_DELAY (1 second)
+     * before sending the first RS. RFC4861 is from 2007, I don't think 1 second is
+     * a suitable delay in 2021. Wait only up to 250 msec instead. */
+
+    delay_msec =
+        g_random_int() % ((guint32)(NM_NDISC_RFC4861_MAX_RTR_SOLICITATION_DELAY * 1000 / 4));
+
+    _LOGD("solicit: schedule sending first solicitation (of %d) in %.3f seconds",
+          priv->router_solicitations,
+          ((double) delay_msec) / 1000);
+
+    priv->solicit_retransmit_time_msec = 0;
+    nm_clear_g_source_inst(&priv->solicit_timer_source);
+    priv->solicit_timer_source = nm_g_timeout_add_source(delay_msec, solicit_timer_cb, ndisc);
+}
+
+/*****************************************************************************/
+
+static gboolean
+announce_router(NMNDisc *ndisc)
+{
+    nm_auto_pop_netns NMPNetns *netns = NULL;
+    NMNDiscClass *              klass = NM_NDISC_GET_CLASS(ndisc);
+    NMNDiscPrivate *            priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    GError *                    error = NULL;
+
+    if (!nm_ndisc_netns_push(ndisc, &netns))
+        return G_SOURCE_REMOVE;
+
+    priv->last_ra = nm_utils_get_monotonic_timestamp_sec();
+    if (klass->send_ra(ndisc, &error)) {
+        _LOGD("router advertisement sent");
+        nm_clear_g_free(&priv->last_error);
+    } else {
+        _MAYBE_WARN("failure sending router advertisement: %s", error->message);
+        g_clear_error(&error);
+    }
+
+    if (--priv->announcements_left) {
+        _LOGD("will resend an initial router advertisement");
+
+        /* Schedule next initial announcement retransmit. */
+        priv->send_ra_id =
+            g_timeout_add_seconds(g_random_int_range(NM_NDISC_ROUTER_ADVERT_DELAY,
+                                                     NM_NDISC_ROUTER_ADVERT_INITIAL_INTERVAL),
+                                  (GSourceFunc) announce_router,
+                                  ndisc);
+    } else {
+        _LOGD("will send an unsolicited router advertisement");
+
+        /* Schedule next unsolicited announcement. */
+        priv->announcements_left = 1;
+        priv->send_ra_id         = g_timeout_add_seconds(NM_NDISC_ROUTER_ADVERT_MAX_INTERVAL,
+                                                 (GSourceFunc) announce_router,
+                                                 ndisc);
+    }
+
+    return G_SOURCE_REMOVE;
+}
+
+static void
+announce_router_initial(NMNDisc *ndisc)
+{
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    _LOGD("will send an initial router advertisement");
+
+    /* Retry three more times. */
+    priv->announcements_left = NM_NDISC_ROUTER_ADVERTISEMENTS_DEFAULT;
+
+    /* Unschedule an unsolicited resend if we are allowed to send now. */
+    if (G_LIKELY(nm_utils_get_monotonic_timestamp_sec() - priv->last_ra
+                 > NM_NDISC_ROUTER_ADVERT_DELAY))
+        nm_clear_g_source(&priv->send_ra_id);
+
+    /* Schedule the initial send rather early. Clamp the delay by minimal
+     * delay and not the initial advert internal so that we start fast. */
+    if (G_LIKELY(!priv->send_ra_id)) {
+        priv->send_ra_id =
+            g_timeout_add_seconds(g_random_int_range(0, NM_NDISC_ROUTER_ADVERT_DELAY),
+                                  (GSourceFunc) announce_router,
+                                  ndisc);
+    }
+}
+
+static void
+announce_router_solicited(NMNDisc *ndisc)
+{
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    _LOGD("will send an solicited router advertisement");
+
+    /* Unschedule an unsolicited resend if we are allowed to send now. */
+    if (nm_utils_get_monotonic_timestamp_sec() - priv->last_ra > NM_NDISC_ROUTER_ADVERT_DELAY)
+        nm_clear_g_source(&priv->send_ra_id);
+
+    if (!priv->send_ra_id) {
+        priv->send_ra_id = g_timeout_add(g_random_int_range(0, NM_NDISC_ROUTER_ADVERT_DELAY_MS),
+                                         (GSourceFunc) announce_router,
+                                         ndisc);
+    }
+}
+
+/*****************************************************************************/
+
+void
+nm_ndisc_set_config(NMNDisc *     ndisc,
+                    const GArray *addresses,
+                    const GArray *dns_servers,
+                    const GArray *dns_domains)
+{
+    gboolean changed = FALSE;
+    guint    i;
+
+    for (i = 0; i < addresses->len; i++) {
+        if (nm_ndisc_add_address(ndisc, &g_array_index(addresses, NMNDiscAddress, i), 0, FALSE))
+            changed = TRUE;
+    }
+
+    for (i = 0; i < dns_servers->len; i++) {
+        if (nm_ndisc_add_dns_server(ndisc,
+                                    &g_array_index(dns_servers, NMNDiscDNSServer, i),
+                                    G_MININT64))
+            changed = TRUE;
+    }
+
+    for (i = 0; i < dns_domains->len; i++) {
+        if (nm_ndisc_add_dns_domain(ndisc,
+                                    &g_array_index(dns_domains, NMNDiscDNSDomain, i),
+                                    G_MININT64))
+            changed = TRUE;
+    }
+
+    if (changed)
+        announce_router_initial(ndisc);
+}
+
+/**
+ * nm_ndisc_set_iid:
+ * @ndisc: the #NMNDisc
+ * @iid: the new interface ID
+ *
+ * Sets the "Modified EUI-64" interface ID to be used when generating
+ * IPv6 addresses using received prefixes. Identifiers are either generated
+ * from the hardware addresses or manually set by the operator with
+ * "ip token" command.
+ *
+ * Upon token change (or initial setting) all addresses generated using
+ * the old identifier are removed. The caller should ensure the addresses
+ * will be reset by soliciting router advertisements.
+ *
+ * In case the stable privacy addressing is used %FALSE is returned and
+ * addresses are left untouched.
+ *
+ * Returns: %TRUE if addresses need to be regenerated, %FALSE otherwise.
+ **/
+gboolean
+nm_ndisc_set_iid(NMNDisc *ndisc, const NMUtilsIPv6IfaceId iid)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+
+    g_return_val_if_fail(NM_IS_NDISC(ndisc), FALSE);
+
+    priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    rdata = &priv->rdata;
+
+    if (priv->iid.id != iid.id) {
+        priv->iid = iid;
+
+        if (priv->addr_gen_mode == NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_STABLE_PRIVACY)
+            return FALSE;
+
+        if (rdata->addresses->len) {
+            _LOGD("IPv6 interface identifier changed, flushing addresses");
+            g_array_remove_range(rdata->addresses, 0, rdata->addresses->len);
+            nm_ndisc_emit_config_change(ndisc, NM_NDISC_CONFIG_ADDRESSES);
+            solicit_timer_start(ndisc);
+        }
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+static gboolean
+ra_timeout_cb(gpointer user_data)
+{
+    NMNDisc *ndisc = NM_NDISC(user_data);
+
+    nm_clear_g_source_inst(&NM_NDISC_GET_PRIVATE(ndisc)->ra_timeout_source);
+    g_signal_emit(ndisc, signals[RA_TIMEOUT_SIGNAL], 0);
+    return G_SOURCE_CONTINUE;
+}
+
+void
+nm_ndisc_start(NMNDisc *ndisc)
+{
+    nm_auto_pop_netns NMPNetns *netns = NULL;
+    NMNDiscPrivate *            priv;
+
+    g_return_if_fail(NM_IS_NDISC(ndisc));
+
+    priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    nm_assert(NM_NDISC_GET_CLASS(ndisc)->start);
+    nm_assert(!priv->ra_timeout_source);
+
+    _LOGD("starting neighbor discovery for ifindex %d%s",
+          priv->ifindex,
+          priv->node_type == NM_NDISC_NODE_TYPE_HOST ? " (solicit)" : " (announce)");
+
+    if (!nm_ndisc_netns_push(ndisc, &netns))
+        return;
+
+    NM_NDISC_GET_CLASS(ndisc)->start(ndisc);
+
+    if (priv->node_type == NM_NDISC_NODE_TYPE_HOST) {
+        G_STATIC_ASSERT_EXPR(NM_RA_TIMEOUT_DEFAULT == 0);
+        G_STATIC_ASSERT_EXPR(NM_RA_TIMEOUT_INFINITY == G_MAXINT32);
+        nm_assert(priv->ra_timeout > 0u);
+        nm_assert(priv->ra_timeout <= NM_RA_TIMEOUT_INFINITY);
+
+        if (priv->ra_timeout < NM_RA_TIMEOUT_INFINITY) {
+            guint timeout_msec;
+
+            _LOGD("scheduling RA timeout in %u seconds", priv->ra_timeout);
+            if (priv->ra_timeout < G_MAXUINT / 1000u)
+                timeout_msec = priv->ra_timeout * 1000u;
+            else
+                timeout_msec = G_MAXUINT;
+            priv->ra_timeout_source = nm_g_timeout_add_source(timeout_msec, ra_timeout_cb, ndisc);
+        }
+
+        solicit_timer_start(ndisc);
+        return;
+    }
+
+    nm_assert(priv->ra_timeout == 0u);
+    nm_assert(priv->node_type == NM_NDISC_NODE_TYPE_ROUTER);
+    announce_router_initial(ndisc);
+}
+
+void
+nm_ndisc_stop(NMNDisc *ndisc)
+{
+    nm_auto_pop_netns NMPNetns *netns = NULL;
+    NMNDiscDataInternal *       rdata;
+    NMNDiscPrivate *            priv;
+
+    g_return_if_fail(NM_IS_NDISC(ndisc));
+
+    priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    nm_assert(NM_NDISC_GET_CLASS(ndisc)->stop);
+
+    _LOGD("stopping neighbor discovery for ifindex %d", priv->ifindex);
+
+    if (!nm_ndisc_netns_push(ndisc, &netns))
+        return;
+
+    NM_NDISC_GET_CLASS(ndisc)->stop(ndisc);
+
+    rdata = &priv->rdata;
+
+    g_array_set_size(rdata->gateways, 0);
+    g_array_set_size(rdata->addresses, 0);
+    g_array_set_size(rdata->routes, 0);
+    g_array_set_size(rdata->dns_servers, 0);
+    g_array_set_size(rdata->dns_domains, 0);
+    priv->rdata.public.hop_limit = 64;
+
+    nm_clear_g_source_inst(&priv->ra_timeout_source);
+    nm_clear_g_source(&priv->send_ra_id);
+    nm_clear_g_free(&priv->last_error);
+    nm_clear_g_source_inst(&priv->timeout_expire_source);
+
+    priv->solicit_retransmit_time_msec = 0;
+    nm_clear_g_source_inst(&priv->solicit_timer_source);
+
+    priv->announcements_left = 0;
+
+    priv->last_ra = G_MININT32;
+}
+
+NMNDiscConfigMap
+nm_ndisc_dad_failed(NMNDisc *ndisc, const struct in6_addr *address, gboolean emit_changed_signal)
+{
+    NMNDiscDataInternal *rdata;
+    guint                i;
+    gboolean             changed = FALSE;
+
+    rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+
+    for (i = 0; i < rdata->addresses->len;) {
+        NMNDiscAddress *item = &g_array_index(rdata->addresses, NMNDiscAddress, i);
+
+        if (IN6_ARE_ADDR_EQUAL(&item->address, address)) {
+            char sbuf[NM_UTILS_INET_ADDRSTRLEN];
+
+            _LOGD("DAD failed for discovered address %s", _nm_utils_inet6_ntop(address, sbuf));
+            changed = TRUE;
+            if (!complete_address(ndisc, item)) {
+                g_array_remove_index(rdata->addresses, i);
+                continue;
+            }
+        }
+        i++;
+    }
+
+    if (emit_changed_signal && changed)
+        nm_ndisc_emit_config_change(ndisc, NM_NDISC_CONFIG_ADDRESSES);
+
+    return changed ? NM_NDISC_CONFIG_ADDRESSES : NM_NDISC_CONFIG_NONE;
+}
+
+#define CONFIG_MAP_MAX_STR 7
+
+static void
+config_map_to_string(NMNDiscConfigMap map, char *p)
+{
+    if (map & NM_NDISC_CONFIG_DHCP_LEVEL)
+        *p++ = 'd';
+    if (map & NM_NDISC_CONFIG_GATEWAYS)
+        *p++ = 'G';
+    if (map & NM_NDISC_CONFIG_ADDRESSES)
+        *p++ = 'A';
+    if (map & NM_NDISC_CONFIG_ROUTES)
+        *p++ = 'R';
+    if (map & NM_NDISC_CONFIG_DNS_SERVERS)
+        *p++ = 'S';
+    if (map & NM_NDISC_CONFIG_DNS_DOMAINS)
+        *p++ = 'D';
+    *p = '\0';
+}
+
+static const char *
+dhcp_level_to_string(NMNDiscDHCPLevel dhcp_level)
+{
+    switch (dhcp_level) {
+    case NM_NDISC_DHCP_LEVEL_NONE:
+        return "none";
+    case NM_NDISC_DHCP_LEVEL_OTHERCONF:
+        return "otherconf";
+    case NM_NDISC_DHCP_LEVEL_MANAGED:
+        return "managed";
+    default:
+        return "INVALID";
+    }
+}
+
+static void
+_config_changed_log(NMNDisc *ndisc, NMNDiscConfigMap changed)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+    guint                i;
+    char                 changedstr[CONFIG_MAP_MAX_STR];
+    char                 addrstr[NM_UTILS_INET_ADDRSTRLEN];
+    char                 str_pref[35];
+    char                 str_exp[100];
+    gint64               now_msec;
+
+    if (!_LOGD_ENABLED())
+        return;
+
+    now_msec = nm_utils_get_monotonic_timestamp_msec();
+
+    priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    rdata = &priv->rdata;
+
+    config_map_to_string(changed, changedstr);
+    _LOGD("neighbor discovery configuration changed [%s]:", changedstr);
+    _LOGD("  dhcp-level %s", dhcp_level_to_string(priv->rdata.public.dhcp_level));
+
+    if (rdata->public.hop_limit)
+        _LOGD("  hop limit      : %d", rdata->public.hop_limit);
+    if (rdata->public.reachable_time_ms)
+        _LOGD("  reachable time : %u", (guint) rdata->public.reachable_time_ms);
+    if (rdata->public.retrans_timer_ms)
+        _LOGD("  retrans timer  : %u", (guint) rdata->public.retrans_timer_ms);
+
+    for (i = 0; i < rdata->gateways->len; i++) {
+        const NMNDiscGateway *gateway = &g_array_index(rdata->gateways, NMNDiscGateway, i);
+
+        _LOGD("  gateway %s pref %s exp %s",
+              _nm_utils_inet6_ntop(&gateway->address, addrstr),
+              nm_icmpv6_router_pref_to_string(gateway->preference, str_pref, sizeof(str_pref)),
+              get_exp(str_exp, now_msec, gateway));
+    }
+    for (i = 0; i < rdata->addresses->len; i++) {
+        const NMNDiscAddress *address = &g_array_index(rdata->addresses, NMNDiscAddress, i);
+
+        _LOGD("  address %s exp %s",
+              _nm_utils_inet6_ntop(&address->address, addrstr),
+              get_exp(str_exp, now_msec, address));
+    }
+    for (i = 0; i < rdata->routes->len; i++) {
+        const NMNDiscRoute *route = &g_array_index(rdata->routes, NMNDiscRoute, i);
+        char                sbuf[NM_UTILS_INET_ADDRSTRLEN];
+
+        _LOGD("  route %s/%u via %s pref %s exp %s",
+              _nm_utils_inet6_ntop(&route->network, addrstr),
+              (guint) route->plen,
+              _nm_utils_inet6_ntop(&route->gateway, sbuf),
+              nm_icmpv6_router_pref_to_string(route->preference, str_pref, sizeof(str_pref)),
+              get_exp(str_exp, now_msec, route));
+    }
+    for (i = 0; i < rdata->dns_servers->len; i++) {
+        const NMNDiscDNSServer *dns_server =
+            &g_array_index(rdata->dns_servers, NMNDiscDNSServer, i);
+
+        _LOGD("  dns_server %s exp %s",
+              _nm_utils_inet6_ntop(&dns_server->address, addrstr),
+              get_exp(str_exp, now_msec, dns_server));
+    }
+    for (i = 0; i < rdata->dns_domains->len; i++) {
+        const NMNDiscDNSDomain *dns_domain =
+            &g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
+
+        _LOGD("  dns_domain %s exp %s", dns_domain->domain, get_exp(str_exp, now_msec, dns_domain));
+    }
+}
+
+/*****************************************************************************/
+
+static gboolean
+_array_set_size_max(GArray *array, guint size_max)
+{
+    nm_assert(array);
+    nm_assert(size_max > 0u);
+
+    if (array->len <= size_max)
+        return FALSE;
+
+    g_array_set_size(array, size_max);
+    return TRUE;
+}
+
+static void
+clean_gateways(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap *changed, gint64 *next_msec)
+{
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    NMNDiscGateway *     arr;
+    guint                i;
+    guint                j;
+
+    if (rdata->gateways->len == 0)
+        return;
+
+    arr = &g_array_index(rdata->gateways, NMNDiscGateway, 0);
+
+    for (i = 0, j = 0; i < rdata->gateways->len; i++) {
+        if (!expiry_next(now_msec, arr[i].expiry_msec, next_msec))
+            continue;
+        if (i != j)
+            arr[j] = arr[i];
+        j++;
+    }
+
+    if (i != j) {
+        *changed |= NM_NDISC_CONFIG_GATEWAYS;
+        g_array_set_size(rdata->gateways, j);
+    }
+
+    if (_array_set_size_max(rdata->gateways, _SIZE_MAX_GATEWAYS))
+        *changed |= NM_NDISC_CONFIG_GATEWAYS;
+
+    _ASSERT_data_gateways(rdata);
+}
+
+static void
+clean_addresses(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap *changed, gint64 *next_msec)
+{
+    NMNDiscPrivate *     priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    NMNDiscAddress *     arr;
+    guint                i;
+    guint                j;
+
+    if (rdata->addresses->len == 0)
+        return;
+
+    arr = &g_array_index(rdata->addresses, NMNDiscAddress, 0);
+
+    for (i = 0, j = 0; i < rdata->addresses->len; i++) {
+        if (!expiry_next(now_msec, arr[i].expiry_msec, next_msec))
+            continue;
+        if (i != j)
+            arr[j] = arr[i];
+        j++;
+    }
+
+    if (i != j) {
+        *changed = NM_NDISC_CONFIG_ADDRESSES;
+        g_array_set_size(rdata->addresses, j);
+    }
+
+    if (_array_set_size_max(rdata->gateways, priv->max_addresses))
+        *changed |= NM_NDISC_CONFIG_ADDRESSES;
+}
+
+static void
+clean_routes(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap *changed, gint64 *next_msec)
+{
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    NMNDiscRoute *       arr;
+    guint                i;
+    guint                j;
+
+    if (rdata->routes->len == 0)
+        return;
+
+    arr = &g_array_index(rdata->routes, NMNDiscRoute, 0);
+
+    for (i = 0, j = 0; i < rdata->routes->len; i++) {
+        if (!expiry_next(now_msec, arr[i].expiry_msec, next_msec))
+            continue;
+        if (i != j)
+            arr[j] = arr[i];
+        j++;
+    }
+
+    if (i != j) {
+        *changed |= NM_NDISC_CONFIG_ROUTES;
+        g_array_set_size(rdata->routes, j);
+    }
+
+    if (_array_set_size_max(rdata->gateways, _SIZE_MAX_ROUTES))
+        *changed |= NM_NDISC_CONFIG_ROUTES;
+}
+
+static void
+clean_dns_servers(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap *changed, gint64 *next_msec)
+{
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    NMNDiscDNSServer *   arr;
+    guint                i;
+    guint                j;
+
+    if (rdata->dns_servers->len == 0)
+        return;
+
+    arr = &g_array_index(rdata->dns_servers, NMNDiscDNSServer, 0);
+
+    for (i = 0, j = 0; i < rdata->dns_servers->len; i++) {
+        if (!expiry_next(now_msec, arr[i].expiry_msec, next_msec))
+            continue;
+        if (i != j)
+            arr[j] = arr[i];
+        j++;
+    }
+
+    if (i != j) {
+        *changed |= NM_NDISC_CONFIG_DNS_SERVERS;
+        g_array_set_size(rdata->dns_servers, j);
+    }
+
+    if (_array_set_size_max(rdata->gateways, _SIZE_MAX_DNS_SERVERS))
+        *changed |= NM_NDISC_CONFIG_DNS_SERVERS;
+}
+
+static void
+clean_dns_domains(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap *changed, gint64 *next_msec)
+{
+    NMNDiscDataInternal *rdata = &NM_NDISC_GET_PRIVATE(ndisc)->rdata;
+    NMNDiscDNSDomain *   arr;
+    guint                i;
+    guint                j;
+
+    if (rdata->dns_domains->len == 0)
+        return;
+
+    arr = &g_array_index(rdata->dns_domains, NMNDiscDNSDomain, 0);
+
+    for (i = 0, j = 0; i < rdata->dns_domains->len; i++) {
+        if (!expiry_next(now_msec, arr[i].expiry_msec, next_msec))
+            continue;
+
+        if (i != j) {
+            g_free(arr[j].domain);
+            arr[j]        = arr[i];
+            arr[i].domain = NULL;
+        }
+
+        j++;
+    }
+
+    if (i != 0) {
+        *changed |= NM_NDISC_CONFIG_DNS_DOMAINS;
+        g_array_set_size(rdata->dns_domains, j);
+    }
+
+    if (_array_set_size_max(rdata->gateways, _SIZE_MAX_DNS_DOMAINS))
+        *changed |= NM_NDISC_CONFIG_DNS_DOMAINS;
+}
+
+static void
+check_timestamps(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap changed)
+{
+    NMNDiscPrivate *priv      = NM_NDISC_GET_PRIVATE(ndisc);
+    gint64          next_msec = G_MAXINT64;
+
+    _LOGT("router-data: check for changed router advertisement data");
+
+    clean_gateways(ndisc, now_msec, &changed, &next_msec);
+    clean_addresses(ndisc, now_msec, &changed, &next_msec);
+    clean_routes(ndisc, now_msec, &changed, &next_msec);
+    clean_dns_servers(ndisc, now_msec, &changed, &next_msec);
+    clean_dns_domains(ndisc, now_msec, &changed, &next_msec);
+
+    nm_assert(next_msec > now_msec);
+
+    nm_clear_g_source_inst(&priv->timeout_expire_source);
+
+    if (next_msec == NM_NDISC_EXPIRY_INFINITY)
+        _LOGD("router-data: next lifetime expiration will happen: never");
+    else {
+        const gint64 timeout_msec = NM_MIN(next_msec - now_msec, ((gint64) G_MAXINT32));
+        const guint  TIMEOUT_APPROX_THRESHOLD_SEC = 10000;
+
+        _LOGD("router-data: next lifetime expiration will happen: in %s%.3f seconds",
+              (timeout_msec / 1000) >= TIMEOUT_APPROX_THRESHOLD_SEC ? " about" : "",
+              ((double) timeout_msec) / 1000);
+
+        priv->timeout_expire_source = nm_g_timeout_add_source_approx(timeout_msec,
+                                                                     TIMEOUT_APPROX_THRESHOLD_SEC,
+                                                                     timeout_expire_cb,
+                                                                     ndisc);
+    }
+
+    /* When we receive an RA, we don't disable solicitations entirely. Instead,
+     * we set the interval the maximum (RFC7559_MRT).
+     *
+     * This contradicts https://tools.ietf.org/html/rfc7559#section-2.1, which says
+     * that we SHOULD stop sending RS if we receive an RA -- but only on a multicast
+     * capable link and if the RA has a valid router lifetime.
+     *
+     * But we really want to recover from a dead router on the network, so we
+     * don't want to cease sending RS entirely.
+     *
+     * But we only re-schedule the timer if the current interval is not already
+     * "RFC7559_MRT * 1000". Otherwise, we already have a slow interval counter
+     * pending. */
+    if (priv->solicit_retransmit_time_msec != RFC7559_MRT * 1000) {
+        gint32 timeout_msec;
+
+        priv->solicit_retransmit_time_msec = RFC7559_MRT * 1000;
+        timeout_msec = solicit_retransmit_time_jitter(priv->solicit_retransmit_time_msec);
+
+        _LOGD("solicit: schedule sending next (slow) solicitation in about %.3f seconds",
+              ((double) timeout_msec) / 1000);
+
+        nm_clear_g_source_inst(&priv->solicit_timer_source);
+        priv->solicit_timer_source =
+            nm_g_timeout_add_source_approx(timeout_msec, 0, solicit_timer_cb, ndisc);
+    }
+
+    if (changed != NM_NDISC_CONFIG_NONE)
+        nm_ndisc_emit_config_change(ndisc, changed);
+}
+
+static gboolean
+timeout_expire_cb(gpointer user_data)
+{
+    check_timestamps(user_data, nm_utils_get_monotonic_timestamp_msec(), NM_NDISC_CONFIG_NONE);
+    return G_SOURCE_CONTINUE;
+}
+
+void
+nm_ndisc_ra_received(NMNDisc *ndisc, gint64 now_msec, NMNDiscConfigMap changed)
+{
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    nm_clear_g_source_inst(&priv->ra_timeout_source);
+    nm_clear_g_free(&priv->last_error);
+    check_timestamps(ndisc, now_msec, changed);
+}
+
+void
+nm_ndisc_rs_received(NMNDisc *ndisc)
+{
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(ndisc);
+
+    nm_clear_g_free(&priv->last_error);
+    announce_router_solicited(ndisc);
+}
+
+/*****************************************************************************/
+
+static void
+dns_domain_free(gpointer data)
+{
+    g_free(((NMNDiscDNSDomain *) (data))->domain);
+}
+
+static void
+set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+{
+    NMNDisc *       self = NM_NDISC(object);
+    NMNDiscPrivate *priv = NM_NDISC_GET_PRIVATE(self);
+    int             i;
+
+    switch (prop_id) {
+    case PROP_PLATFORM:
+        /* construct-only */
+        priv->platform = g_value_get_object(value) ?: NM_PLATFORM_GET;
+        if (!priv->platform)
+            g_return_if_reached();
+
+        g_object_ref(priv->platform);
+
+        priv->netns = nm_platform_netns_get(priv->platform);
+        if (priv->netns)
+            g_object_ref(priv->netns);
+
+        g_return_if_fail(!priv->netns || priv->netns == nmp_netns_get_current());
+        break;
+    case PROP_IFINDEX:
+        /* construct-only */
+        priv->ifindex = g_value_get_int(value);
+        g_return_if_fail(priv->ifindex > 0);
+        break;
+    case PROP_IFNAME:
+        /* construct-only */
+        priv->ifname = g_value_dup_string(value);
+        g_return_if_fail(priv->ifname && priv->ifname[0]);
+        break;
+    case PROP_STABLE_TYPE:
+        /* construct-only */
+        priv->stable_type = g_value_get_int(value);
+        break;
+    case PROP_NETWORK_ID:
+        /* construct-only */
+        priv->network_id = g_value_dup_string(value);
+        g_return_if_fail(priv->network_id);
+        break;
+    case PROP_ADDR_GEN_MODE:
+        /* construct-only */
+        priv->addr_gen_mode = g_value_get_int(value);
+        break;
+    case PROP_MAX_ADDRESSES:
+        /* construct-only */
+        i = g_value_get_int(value);
+        nm_assert(i >= 0);
+        priv->max_addresses = i;
+
+        if (priv->max_addresses <= 0)
+            priv->max_addresses = _SIZE_MAX_ADDRESSES;
+        else if (priv->max_addresses > 3u * _SIZE_MAX_ADDRESSES)
+            priv->max_addresses = 3u * _SIZE_MAX_ADDRESSES;
+        break;
+    case PROP_RA_TIMEOUT:
+        /* construct-only */
+        priv->ra_timeout = g_value_get_uint(value);
+        nm_assert(priv->ra_timeout <= NM_RA_TIMEOUT_INFINITY);
+        break;
+    case PROP_ROUTER_SOLICITATIONS:
+        /* construct-only */
+        priv->router_solicitations = g_value_get_int(value);
+        break;
+    case PROP_ROUTER_SOLICITATION_INTERVAL:
+        /* construct-only */
+        priv->router_solicitation_interval = g_value_get_int(value);
+        break;
+    case PROP_NODE_TYPE:
+        /* construct-only */
+        priv->node_type = g_value_get_int(value);
+        nm_assert(NM_IN_SET(priv->node_type, NM_NDISC_NODE_TYPE_HOST, NM_NDISC_NODE_TYPE_ROUTER));
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+nm_ndisc_init(NMNDisc *ndisc)
+{
+    NMNDiscPrivate *     priv;
+    NMNDiscDataInternal *rdata;
+
+    priv         = G_TYPE_INSTANCE_GET_PRIVATE(ndisc, NM_TYPE_NDISC, NMNDiscPrivate);
+    ndisc->_priv = priv;
+
+    rdata = &priv->rdata;
+
+    rdata->gateways    = g_array_new(FALSE, FALSE, sizeof(NMNDiscGateway));
+    rdata->addresses   = g_array_new(FALSE, FALSE, sizeof(NMNDiscAddress));
+    rdata->routes      = g_array_new(FALSE, FALSE, sizeof(NMNDiscRoute));
+    rdata->dns_servers = g_array_new(FALSE, FALSE, sizeof(NMNDiscDNSServer));
+    rdata->dns_domains = g_array_new(FALSE, FALSE, sizeof(NMNDiscDNSDomain));
+    g_array_set_clear_func(rdata->dns_domains, dns_domain_free);
+    priv->rdata.public.hop_limit = 64;
+}
+
+static void
+dispose(GObject *object)
+{
+    NMNDisc *       ndisc = NM_NDISC(object);
+    NMNDiscPrivate *priv  = NM_NDISC_GET_PRIVATE(ndisc);
+
+    nm_clear_g_source_inst(&priv->ra_timeout_source);
+    nm_clear_g_source_inst(&priv->solicit_timer_source);
+    nm_clear_g_source(&priv->send_ra_id);
+    nm_clear_g_free(&priv->last_error);
+
+    nm_clear_g_source_inst(&priv->timeout_expire_source);
+
+    G_OBJECT_CLASS(nm_ndisc_parent_class)->dispose(object);
+}
+
+static void
+finalize(GObject *object)
+{
+    NMNDisc *            ndisc = NM_NDISC(object);
+    NMNDiscPrivate *     priv  = NM_NDISC_GET_PRIVATE(ndisc);
+    NMNDiscDataInternal *rdata = &priv->rdata;
+
+    g_free(priv->ifname);
+    g_free(priv->network_id);
+
+    g_array_unref(rdata->gateways);
+    g_array_unref(rdata->addresses);
+    g_array_unref(rdata->routes);
+    g_array_unref(rdata->dns_servers);
+    g_array_unref(rdata->dns_domains);
+
+    g_clear_object(&priv->netns);
+    g_clear_object(&priv->platform);
+
+    G_OBJECT_CLASS(nm_ndisc_parent_class)->finalize(object);
+}
+
+static void
+nm_ndisc_class_init(NMNDiscClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS(klass);
+
+    g_type_class_add_private(klass, sizeof(NMNDiscPrivate));
+
+    object_class->set_property = set_property;
+    object_class->dispose      = dispose;
+    object_class->finalize     = finalize;
+
+    obj_properties[PROP_PLATFORM] =
+        g_param_spec_object(NM_NDISC_PLATFORM,
+                            "",
+                            "",
+                            NM_TYPE_PLATFORM,
+                            G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_IFINDEX] =
+        g_param_spec_int(NM_NDISC_IFINDEX,
+                         "",
+                         "",
+                         0,
+                         G_MAXINT,
+                         0,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_IFNAME] =
+        g_param_spec_string(NM_NDISC_IFNAME,
+                            "",
+                            "",
+                            NULL,
+                            G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_STABLE_TYPE] =
+        g_param_spec_int(NM_NDISC_STABLE_TYPE,
+                         "",
+                         "",
+                         NM_UTILS_STABLE_TYPE_UUID,
+                         NM_UTILS_STABLE_TYPE_RANDOM,
+                         NM_UTILS_STABLE_TYPE_UUID,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_NETWORK_ID] =
+        g_param_spec_string(NM_NDISC_NETWORK_ID,
+                            "",
+                            "",
+                            NULL,
+                            G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_ADDR_GEN_MODE] =
+        g_param_spec_int(NM_NDISC_ADDR_GEN_MODE,
+                         "",
+                         "",
+                         NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_EUI64,
+                         NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_STABLE_PRIVACY,
+                         NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_EUI64,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_MAX_ADDRESSES] =
+        g_param_spec_int(NM_NDISC_MAX_ADDRESSES,
+                         "",
+                         "",
+                         0,
+                         G_MAXINT32,
+                         NM_NDISC_MAX_ADDRESSES_DEFAULT,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    G_STATIC_ASSERT_EXPR(G_MAXINT32 == NM_RA_TIMEOUT_INFINITY);
+    obj_properties[PROP_RA_TIMEOUT] =
+        g_param_spec_uint(NM_NDISC_RA_TIMEOUT,
+                          "",
+                          "",
+                          0,
+                          G_MAXINT32,
+                          0,
+                          G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_ROUTER_SOLICITATIONS] =
+        g_param_spec_int(NM_NDISC_ROUTER_SOLICITATIONS,
+                         "",
+                         "",
+                         1,
+                         G_MAXINT32,
+                         NM_NDISC_ROUTER_SOLICITATIONS_DEFAULT,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_ROUTER_SOLICITATION_INTERVAL] =
+        g_param_spec_int(NM_NDISC_ROUTER_SOLICITATION_INTERVAL,
+                         "",
+                         "",
+                         1,
+                         G_MAXINT32,
+                         NM_NDISC_RFC4861_RTR_SOLICITATION_INTERVAL,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    obj_properties[PROP_NODE_TYPE] =
+        g_param_spec_int(NM_NDISC_NODE_TYPE,
+                         "",
+                         "",
+                         NM_NDISC_NODE_TYPE_INVALID,
+                         NM_NDISC_NODE_TYPE_ROUTER,
+                         NM_NDISC_NODE_TYPE_INVALID,
+                         G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+    g_object_class_install_properties(object_class, _PROPERTY_ENUMS_LAST, obj_properties);
+
+    signals[CONFIG_RECEIVED]   = g_signal_new(NM_NDISC_CONFIG_RECEIVED,
+                                            G_OBJECT_CLASS_TYPE(klass),
+                                            G_SIGNAL_RUN_FIRST,
+                                            0,
+                                            NULL,
+                                            NULL,
+                                            NULL,
+                                            G_TYPE_NONE,
+                                            2,
+                                            G_TYPE_POINTER,
+                                            G_TYPE_UINT);
+    signals[RA_TIMEOUT_SIGNAL] = g_signal_new(NM_NDISC_RA_TIMEOUT_SIGNAL,
+                                              G_OBJECT_CLASS_TYPE(klass),
+                                              G_SIGNAL_RUN_FIRST,
+                                              0,
+                                              NULL,
+                                              NULL,
+                                              NULL,
+                                              G_TYPE_NONE,
+                                              0);
+}
diff --git a/src/core/ndisc/nm-ndisc.h b/src/core/ndisc/nm-ndisc.h
new file mode 100644
index 00000000..93aee4db
--- /dev/null
+++ b/src/core/ndisc/nm-ndisc.h
@@ -0,0 +1,278 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_NDISC_H__
+#define __NETWORKMANAGER_NDISC_H__
+
+#include <stdlib.h>
+#include <netinet/in.h>
+#include <linux/if_addr.h>
+
+#include "nm-setting-ip6-config.h"
+#include "NetworkManagerUtils.h"
+
+#include "platform/nm-platform.h"
+#include "platform/nmp-object.h"
+
+#define NM_RA_TIMEOUT_DEFAULT  ((guint32) 0)
+#define NM_RA_TIMEOUT_INFINITY ((guint32) G_MAXINT32)
+
+#define NM_TYPE_NDISC            (nm_ndisc_get_type())
+#define NM_NDISC(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_NDISC, NMNDisc))
+#define NM_NDISC_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_NDISC, NMNDiscClass))
+#define NM_IS_NDISC(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_NDISC))
+#define NM_IS_NDISC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_NDISC))
+#define NM_NDISC_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_NDISC, NMNDiscClass))
+
+#define NM_NDISC_PLATFORM                     "platform"
+#define NM_NDISC_IFINDEX                      "ifindex"
+#define NM_NDISC_IFNAME                       "ifname"
+#define NM_NDISC_NETWORK_ID                   "network-id"
+#define NM_NDISC_ADDR_GEN_MODE                "addr-gen-mode"
+#define NM_NDISC_STABLE_TYPE                  "stable-type"
+#define NM_NDISC_NODE_TYPE                    "node-type"
+#define NM_NDISC_MAX_ADDRESSES                "max-addresses"
+#define NM_NDISC_RA_TIMEOUT                   "ra-timeout"
+#define NM_NDISC_ROUTER_SOLICITATIONS         "router-solicitations"
+#define NM_NDISC_ROUTER_SOLICITATION_INTERVAL "router-solicitation-interval"
+
+#define NM_NDISC_CONFIG_RECEIVED   "config-received"
+#define NM_NDISC_RA_TIMEOUT_SIGNAL "ra-timeout-signal"
+
+typedef enum {
+    NM_NDISC_DHCP_LEVEL_UNKNOWN,
+    NM_NDISC_DHCP_LEVEL_NONE,
+    NM_NDISC_DHCP_LEVEL_OTHERCONF,
+    NM_NDISC_DHCP_LEVEL_MANAGED
+} NMNDiscDHCPLevel;
+
+#define NM_NDISC_INFINITY_U32 ((uint32_t) -1)
+
+/* It's important that this is G_MAXINT64, so that we can meaningfully do
+ * MIN(e1, e2) to find the minimum expiry time (and properly handle if any
+ * of them is infinity).
+ *
+ * While usually you assign this to "expiry_msec", you might say the
+ * unit of it is milliseconds. But of course, infinity has not really a unit. */
+#define NM_NDISC_EXPIRY_INFINITY G_MAXINT64
+
+/* in common cases, the expiry_msec tracks the timestamp in nm_utils_get_monotonic_timestamp_mses()
+ * timestamp when the item expires.
+ *
+ * When we configure an NMNDiscAddress to be announced via the router advertisement,
+ * then that address does not have a fixed expiry point in time, instead, the expiry
+ * really contains the lifetime from the moment when we send the router advertisement.
+ * In that case, the expiry_msec is more a "lifetime" that starts counting at timestamp
+ * zero.
+ *
+ * The unit is milliseconds (but of course, the timestamp is zero, so it doesn't really matter). */
+#define NM_NDISC_EXPIRY_BASE_TIMESTAMP ((gint64) 0)
+
+static inline gint64
+_nm_ndisc_lifetime_to_expiry(gint64 now_msec, guint32 lifetime)
+{
+    if (lifetime == NM_NDISC_INFINITY_U32)
+        return NM_NDISC_EXPIRY_INFINITY;
+    return now_msec + (((gint64) lifetime) * 1000);
+}
+
+static inline gint64
+_nm_ndisc_lifetime_from_expiry(gint64 now_msec, gint64 expiry_msec, gboolean ceil)
+{
+    gint64 diff;
+
+    if (expiry_msec == NM_NDISC_EXPIRY_INFINITY)
+        return NM_NDISC_INFINITY_U32;
+
+    /* we don't expect nor handle integer overflow. The time stamp and expiry
+     * should be reasonably small so that it cannot happen. */
+
+    diff = expiry_msec - now_msec;
+
+    if (diff <= 0)
+        return 0;
+
+    if (ceil) {
+        /* we ceil() towards the next full second (instead of floor()). */
+        diff += 999;
+    }
+
+    return NM_MIN(diff / 1000, (gint64)(G_MAXUINT32 - 1));
+}
+
+/*****************************************************************************/
+
+typedef struct _NMNDiscGateway {
+    struct in6_addr    address;
+    gint64             expiry_msec;
+    NMIcmpv6RouterPref preference;
+} NMNDiscGateway;
+
+typedef struct _NMNDiscAddress {
+    struct in6_addr address;
+    gint64          expiry_msec;
+    gint64          expiry_preferred_msec;
+    guint8          dad_counter;
+} NMNDiscAddress;
+
+typedef struct _NMNDiscRoute {
+    struct in6_addr    network;
+    struct in6_addr    gateway;
+    gint64             expiry_msec;
+    NMIcmpv6RouterPref preference;
+    guint8             plen;
+} NMNDiscRoute;
+
+typedef struct {
+    struct in6_addr address;
+    gint64          expiry_msec;
+} NMNDiscDNSServer;
+
+typedef struct {
+    char * domain;
+    gint64 expiry_msec;
+} NMNDiscDNSDomain;
+
+typedef enum {
+    NM_NDISC_CONFIG_NONE           = 0,
+    NM_NDISC_CONFIG_DHCP_LEVEL     = 1 << 0,
+    NM_NDISC_CONFIG_GATEWAYS       = 1 << 1,
+    NM_NDISC_CONFIG_ADDRESSES      = 1 << 2,
+    NM_NDISC_CONFIG_ROUTES         = 1 << 3,
+    NM_NDISC_CONFIG_DNS_SERVERS    = 1 << 4,
+    NM_NDISC_CONFIG_DNS_DOMAINS    = 1 << 5,
+    NM_NDISC_CONFIG_HOP_LIMIT      = 1 << 6,
+    NM_NDISC_CONFIG_MTU            = 1 << 7,
+    NM_NDISC_CONFIG_REACHABLE_TIME = 1 << 8,
+    NM_NDISC_CONFIG_RETRANS_TIMER  = 1 << 9,
+} NMNDiscConfigMap;
+
+typedef enum {
+    NM_NDISC_NODE_TYPE_INVALID,
+    NM_NDISC_NODE_TYPE_HOST,
+    NM_NDISC_NODE_TYPE_ROUTER,
+} NMNDiscNodeType;
+
+#define NM_NDISC_RFC4861_RTR_SOLICITATION_INTERVAL  4 /* seconds */
+#define NM_NDISC_RFC4861_MAX_RTR_SOLICITATION_DELAY 1 /* seconds */
+
+#define NM_NDISC_MAX_ADDRESSES_DEFAULT          16
+#define NM_NDISC_ROUTER_SOLICITATIONS_DEFAULT   3 /* RFC4861, MAX_RTR_SOLICITATIONS */
+#define NM_NDISC_ROUTER_ADVERTISEMENTS_DEFAULT  3 /* RFC4861, MAX_INITIAL_RTR_ADVERTISEMENTS */
+#define NM_NDISC_ROUTER_ADVERT_DELAY            3 /* RFC4861, MIN_DELAY_BETWEEN_RAS */
+#define NM_NDISC_ROUTER_ADVERT_INITIAL_INTERVAL 16 /* RFC4861, MAX_INITIAL_RTR_ADVERT_INTERVAL */
+#define NM_NDISC_ROUTER_ADVERT_DELAY_MS         500 /* RFC4861, MAX_RA_DELAY_TIME */
+#define NM_NDISC_ROUTER_ADVERT_MAX_INTERVAL     600 /* RFC4861, MaxRtrAdvInterval default */
+#define NM_NDISC_ROUTER_LIFETIME                900 /* 1.5 * NM_NDISC_ROUTER_ADVERT_MAX_INTERVAL */
+
+struct _NMNDiscPrivate;
+struct _NMNDiscDataInternal;
+
+typedef struct {
+    NMNDiscDHCPLevel dhcp_level;
+    guint32          mtu;
+    int              hop_limit;
+    guint32          reachable_time_ms;
+    guint32          retrans_timer_ms;
+
+    guint gateways_n;
+    guint addresses_n;
+    guint routes_n;
+    guint dns_servers_n;
+    guint dns_domains_n;
+
+    const NMNDiscGateway *  gateways;
+    const NMNDiscAddress *  addresses;
+    const NMNDiscRoute *    routes;
+    const NMNDiscDNSServer *dns_servers;
+    const NMNDiscDNSDomain *dns_domains;
+} NMNDiscData;
+
+/**
+ * NMNDisc:
+ *
+ * Interface-specific structure that handles incoming router advertisements,
+ * caches advertised items and removes them when they are obsolete.
+ */
+typedef struct {
+    GObject parent;
+    union {
+        struct _NMNDiscPrivate *     _priv;
+        struct _NMNDiscDataInternal *rdata;
+    };
+} NMNDisc;
+
+typedef struct {
+    GObjectClass parent;
+
+    void (*start)(NMNDisc *ndisc);
+    void (*stop)(NMNDisc *ndisc);
+    gboolean (*send_rs)(NMNDisc *ndisc, GError **error);
+    gboolean (*send_ra)(NMNDisc *ndisc, GError **error);
+} NMNDiscClass;
+
+GType nm_ndisc_get_type(void);
+
+void nm_ndisc_emit_config_change(NMNDisc *self, NMNDiscConfigMap changed);
+
+int             nm_ndisc_get_ifindex(NMNDisc *self);
+const char *    nm_ndisc_get_ifname(NMNDisc *self);
+NMNDiscNodeType nm_ndisc_get_node_type(NMNDisc *self);
+
+gboolean nm_ndisc_set_iid(NMNDisc *ndisc, const NMUtilsIPv6IfaceId iid);
+void     nm_ndisc_start(NMNDisc *ndisc);
+void     nm_ndisc_stop(NMNDisc *ndisc);
+NMNDiscConfigMap
+nm_ndisc_dad_failed(NMNDisc *ndisc, const struct in6_addr *address, gboolean emit_changed_signal);
+void nm_ndisc_set_config(NMNDisc *     ndisc,
+                         const GArray *addresses,
+                         const GArray *dns_servers,
+                         const GArray *dns_domains);
+
+NMPlatform *nm_ndisc_get_platform(NMNDisc *self);
+NMPNetns *  nm_ndisc_netns_get(NMNDisc *self);
+gboolean    nm_ndisc_netns_push(NMNDisc *self, NMPNetns **netns);
+
+static inline gboolean
+nm_ndisc_dad_addr_is_fail_candidate_event(NMPlatformSignalChangeType  change_type,
+                                          const NMPlatformIP6Address *addr)
+{
+    return !NM_FLAGS_HAS(addr->n_ifa_flags, IFA_F_TEMPORARY)
+           && ((change_type == NM_PLATFORM_SIGNAL_CHANGED && addr->n_ifa_flags & IFA_F_DADFAILED)
+               || (change_type == NM_PLATFORM_SIGNAL_REMOVED
+                   && addr->n_ifa_flags & IFA_F_TENTATIVE));
+}
+
+static inline gboolean
+nm_ndisc_dad_addr_is_fail_candidate(NMPlatform *platform, const NMPObject *obj)
+{
+    const NMPlatformIP6Address *addr;
+
+    addr = NMP_OBJECT_CAST_IP6_ADDRESS(
+        nm_platform_lookup_obj(platform, NMP_CACHE_ID_TYPE_OBJECT_TYPE, obj));
+    if (addr
+        && (NM_FLAGS_HAS(addr->n_ifa_flags, IFA_F_TEMPORARY)
+            || !NM_FLAGS_HAS(addr->n_ifa_flags, IFA_F_DADFAILED))) {
+        /* the address still/again exists and is not in DADFAILED state. Skip it. */
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+struct _NML3ConfigData;
+
+struct _NML3ConfigData *nm_ndisc_data_to_l3cd(NMDedupMultiIndex *       multi_idx,
+                                              int                       ifindex,
+                                              const NMNDiscData *       rdata,
+                                              NMSettingIP6ConfigPrivacy ip6_privacy,
+                                              guint32                   route_table,
+                                              guint32                   route_metric,
+                                              gboolean                  kernel_support_rta_pref,
+                                              gboolean kernel_support_extended_ifa_flags);
+
+#endif /* __NETWORKMANAGER_NDISC_H__ */
diff --git a/src/core/ndisc/tests/meson.build b/src/core/ndisc/tests/meson.build
new file mode 100644
index 00000000..6a2e70f0
--- /dev/null
+++ b/src/core/ndisc/tests/meson.build
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+test_unit = 'test-ndisc-fake'
+
+exe = executable(
+  test_unit,
+  test_unit + '.c',
+  dependencies: libNetworkManagerTest_dep,
+  c_args: test_c_flags,
+)
+
+test(
+  'ndisc/' + test_unit,
+  test_script,
+  args: test_args + [exe.full_path()],
+  timeout: default_test_timeout,
+)
+
+test = 'test-ndisc-linux'
+
+exe = executable(
+  test,
+  test + '.c',
+  dependencies: libNetworkManagerTest_dep,
+  c_args: test_c_flags,
+)
diff --git a/src/core/ndisc/tests/test-ndisc-fake.c b/src/core/ndisc/tests/test-ndisc-fake.c
new file mode 100644
index 00000000..f201bc56
--- /dev/null
+++ b/src/core/ndisc/tests/test-ndisc-fake.c
@@ -0,0 +1,657 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include <syslog.h>
+
+#include "ndisc/nm-ndisc.h"
+#include "ndisc/nm-fake-ndisc.h"
+
+#include "platform/nm-fake-platform.h"
+
+#include "nm-test-utils-core.h"
+
+/*****************************************************************************/
+
+static NMFakeNDisc *
+ndisc_new(void)
+{
+    NMNDisc *          ndisc;
+    const int          ifindex = 1;
+    const char *       ifname  = nm_platform_link_get_name(NM_PLATFORM_GET, ifindex);
+    NMUtilsIPv6IfaceId iid     = {};
+
+    ndisc        = nm_fake_ndisc_new(ifindex, ifname);
+    iid.id_u8[7] = 1;
+    nm_ndisc_set_iid(ndisc, iid);
+    g_assert(ndisc);
+
+    return NM_FAKE_NDISC(ndisc);
+}
+
+/*****************************************************************************/
+
+static void
+match_gateway(const NMNDiscData *rdata,
+              guint              idx,
+              const char *       addr,
+              gint64             expiry_msec,
+              NMIcmpv6RouterPref pref)
+{
+    const NMNDiscGateway *gw;
+
+    g_assert(rdata);
+    g_assert_cmpint(idx, <, rdata->gateways_n);
+    g_assert(rdata->gateways);
+
+    gw = &rdata->gateways[idx];
+
+    nmtst_assert_ip6_address(&gw->address, addr);
+    g_assert_cmpint(gw->expiry_msec, ==, expiry_msec);
+    g_assert_cmpint(gw->preference, ==, pref);
+}
+
+#define match_address(rdata, idx, addr, _expiry_msec, _expiry_preferred_msec)     \
+    G_STMT_START                                                                  \
+    {                                                                             \
+        const NMNDiscData *   _rdata = (rdata);                                   \
+        guint                 _idx   = (idx);                                     \
+        const NMNDiscAddress *_a;                                                 \
+                                                                                  \
+        g_assert(_rdata);                                                         \
+        g_assert_cmpint(_idx, <, _rdata->addresses_n);                            \
+        g_assert(_rdata->addresses);                                              \
+                                                                                  \
+        _a = &_rdata->addresses[_idx];                                            \
+                                                                                  \
+        nmtst_assert_ip6_address(&_a->address, (addr));                           \
+        g_assert_cmpint(_a->expiry_msec, ==, (_expiry_msec));                     \
+        g_assert_cmpint(_a->expiry_preferred_msec, ==, (_expiry_preferred_msec)); \
+    }                                                                             \
+    G_STMT_END
+
+#define match_route(rdata, idx, nw, pl, gw, _expiry_msec, pref) \
+    G_STMT_START                                                \
+    {                                                           \
+        const NMNDiscData * _rdata = (rdata);                   \
+        guint               _idx   = (idx);                     \
+        const NMNDiscRoute *_r;                                 \
+        int                 _plen = (pl);                       \
+                                                                \
+        g_assert(_rdata);                                       \
+        g_assert_cmpint(_idx, <, _rdata->routes_n);             \
+        g_assert(_rdata->routes);                               \
+        g_assert(_plen > 0 && _plen <= 128);                    \
+                                                                \
+        _r = &_rdata->routes[idx];                              \
+                                                                \
+        nmtst_assert_ip6_address(&_r->network, (nw));           \
+        g_assert_cmpint((int) _r->plen, ==, _plen);             \
+        nmtst_assert_ip6_address(&_r->gateway, (gw));           \
+        g_assert_cmpint(_r->expiry_msec, ==, (_expiry_msec));   \
+        g_assert_cmpint(_r->preference, ==, (pref));            \
+    }                                                           \
+    G_STMT_END
+
+static void
+match_dns_server(const NMNDiscData *rdata, guint idx, const char *addr, gint64 expiry_msec)
+{
+    const NMNDiscDNSServer *dns;
+
+    g_assert(rdata);
+    g_assert_cmpint(idx, <, rdata->dns_servers_n);
+    g_assert(rdata->dns_servers);
+
+    dns = &rdata->dns_servers[idx];
+
+    nmtst_assert_ip6_address(&dns->address, addr);
+    g_assert_cmpint(dns->expiry_msec, ==, expiry_msec);
+}
+
+static void
+match_dns_domain(const NMNDiscData *rdata, guint idx, const char *domain, gint64 expiry_msec)
+{
+    const NMNDiscDNSDomain *dns;
+
+    g_assert(rdata);
+    g_assert_cmpint(idx, <, rdata->dns_domains_n);
+    g_assert(rdata->dns_domains);
+
+    dns = &rdata->dns_domains[idx];
+
+    g_assert_cmpstr(dns->domain, ==, domain);
+    g_assert_cmpint(dns->expiry_msec, ==, expiry_msec);
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    GMainLoop *loop;
+    gint64     timestamp_msec_1;
+    guint      counter;
+    guint      rs_counter;
+    gint64     first_solicit_msec;
+    guint32    timeout_id;
+} TestData;
+
+/*****************************************************************************/
+
+static void
+test_simple_changed(NMNDisc *ndisc, const NMNDiscData *rdata, guint changed_int, TestData *data)
+{
+    NMNDiscConfigMap changed = changed_int;
+
+    switch (data->counter++) {
+    case 0:
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_DHCP_LEVEL | NM_NDISC_CONFIG_GATEWAYS
+                            | NM_NDISC_CONFIG_ADDRESSES | NM_NDISC_CONFIG_ROUTES
+                            | NM_NDISC_CONFIG_DNS_SERVERS | NM_NDISC_CONFIG_DNS_DOMAINS
+                            | NM_NDISC_CONFIG_HOP_LIMIT | NM_NDISC_CONFIG_MTU);
+        g_assert_cmpint(rdata->dhcp_level, ==, NM_NDISC_DHCP_LEVEL_OTHERCONF);
+        match_gateway(rdata,
+                      0,
+                      "fe80::1",
+                      data->timestamp_msec_1 + 10000,
+                      NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1 + 10000);
+        match_route(rdata, 0, "2001:db8:a:a::", 64, "fe80::1", data->timestamp_msec_1 + 10000, 10);
+        match_dns_server(rdata, 0, "2001:db8:c:c::1", data->timestamp_msec_1 + 10000);
+        match_dns_domain(rdata, 0, "foobar.com", data->timestamp_msec_1 + 3500);
+
+        g_assert(nm_fake_ndisc_done(NM_FAKE_NDISC(ndisc)));
+        break;
+    case 1:
+        g_main_loop_quit(data->loop);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void
+test_simple(void)
+{
+    nm_auto_unref_gmainloop GMainLoop *loop = g_main_loop_new(NULL, FALSE);
+    gs_unref_object NMFakeNDisc *ndisc      = ndisc_new();
+    const gint64                 now_msec   = nm_utils_get_monotonic_timestamp_msec();
+    TestData                     data       = {
+        .loop             = loop,
+        .timestamp_msec_1 = now_msec,
+    };
+    guint id;
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_OTHERCONF, 4, 1500);
+    g_assert(id);
+
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:a::",
+                             64,
+                             "fe80::1",
+                             now_msec + 10000,
+                             now_msec + 10000,
+                             10);
+    nm_fake_ndisc_add_dns_server(ndisc, id, "2001:db8:c:c::1", now_msec + 10000);
+    nm_fake_ndisc_add_dns_domain(ndisc, id, "foobar.com", now_msec + 3500);
+
+    g_signal_connect(ndisc, NM_NDISC_CONFIG_RECEIVED, G_CALLBACK(test_simple_changed), &data);
+
+    nm_ndisc_start(NM_NDISC(ndisc));
+    nmtst_main_loop_run_assert(data.loop, 15000);
+    g_assert_cmpint(data.counter, ==, 2);
+}
+
+/*****************************************************************************/
+
+static void
+test_everything_rs_sent(NMNDisc *ndisc, TestData *data)
+{
+    g_assert_cmpint(data->rs_counter, ==, 0);
+    data->rs_counter++;
+}
+
+static void
+test_everything_changed(NMNDisc *ndisc, const NMNDiscData *rdata, guint changed_int, TestData *data)
+{
+    NMNDiscConfigMap changed = changed_int;
+
+    if (data->counter == 0) {
+        g_assert_cmpint(data->rs_counter, ==, 1);
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_DHCP_LEVEL | NM_NDISC_CONFIG_GATEWAYS
+                            | NM_NDISC_CONFIG_ADDRESSES | NM_NDISC_CONFIG_ROUTES
+                            | NM_NDISC_CONFIG_DNS_SERVERS | NM_NDISC_CONFIG_DNS_DOMAINS
+                            | NM_NDISC_CONFIG_HOP_LIMIT | NM_NDISC_CONFIG_MTU);
+        match_gateway(rdata,
+                      0,
+                      "fe80::1",
+                      data->timestamp_msec_1 + 10000,
+                      NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1 + 10000);
+        match_route(rdata, 0, "2001:db8:a:a::", 64, "fe80::1", data->timestamp_msec_1 + 10000, 10);
+        match_dns_server(rdata, 0, "2001:db8:c:c::1", data->timestamp_msec_1 + 10000);
+        match_dns_domain(rdata, 0, "foobar.com", data->timestamp_msec_1 + 10000);
+    } else if (data->counter == 1) {
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_GATEWAYS | NM_NDISC_CONFIG_ADDRESSES
+                            | NM_NDISC_CONFIG_ROUTES | NM_NDISC_CONFIG_DNS_SERVERS
+                            | NM_NDISC_CONFIG_DNS_DOMAINS);
+
+        g_assert_cmpint(rdata->gateways_n, ==, 1);
+        match_gateway(rdata,
+                      0,
+                      "fe80::2",
+                      data->timestamp_msec_1 + 10000,
+                      NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        g_assert_cmpint(rdata->addresses_n, ==, 2);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1);
+        match_address(rdata,
+                      1,
+                      "2001:db8:a:b::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1 + 10000);
+        g_assert_cmpint(rdata->routes_n, ==, 1);
+        match_route(rdata, 0, "2001:db8:a:b::", 64, "fe80::2", data->timestamp_msec_1 + 10000, 10);
+        g_assert_cmpint(rdata->dns_servers_n, ==, 1);
+        match_dns_server(rdata, 0, "2001:db8:c:c::2", data->timestamp_msec_1 + 10000);
+        g_assert_cmpint(rdata->dns_domains_n, ==, 1);
+        match_dns_domain(rdata, 0, "foobar2.com", data->timestamp_msec_1 + 10000);
+
+        g_assert(nm_fake_ndisc_done(NM_FAKE_NDISC(ndisc)));
+        g_main_loop_quit(data->loop);
+    } else
+        g_assert_not_reached();
+
+    data->counter++;
+}
+
+static void
+test_everything(void)
+{
+    nm_auto_unref_gmainloop GMainLoop *loop = g_main_loop_new(NULL, FALSE);
+    gs_unref_object NMFakeNDisc *ndisc      = ndisc_new();
+    const gint64                 now_msec   = nm_utils_get_monotonic_timestamp_msec();
+    TestData                     data       = {
+        .loop             = loop,
+        .timestamp_msec_1 = now_msec,
+    };
+    guint id;
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:a::",
+                             64,
+                             "fe80::1",
+                             now_msec + 10000,
+                             now_msec + 10000,
+                             10);
+    nm_fake_ndisc_add_dns_server(ndisc, id, "2001:db8:c:c::1", now_msec + 10000);
+    nm_fake_ndisc_add_dns_domain(ndisc, id, "foobar.com", now_msec + 10000);
+
+    /* expire everything from the first RA in the second */
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+    nm_fake_ndisc_add_prefix(ndisc, id, "2001:db8:a:a::", 64, "fe80::1", now_msec, now_msec, 0);
+    nm_fake_ndisc_add_dns_server(ndisc, id, "2001:db8:c:c::1", now_msec);
+    nm_fake_ndisc_add_dns_domain(ndisc, id, "foobar.com", now_msec);
+
+    /* and add some new stuff */
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::2", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:b::",
+                             64,
+                             "fe80::2",
+                             now_msec + 10000,
+                             now_msec + 10000,
+                             10);
+    nm_fake_ndisc_add_dns_server(ndisc, id, "2001:db8:c:c::2", now_msec + 10000);
+    nm_fake_ndisc_add_dns_domain(ndisc, id, "foobar2.com", now_msec + 10000);
+
+    g_signal_connect(ndisc, NM_NDISC_CONFIG_RECEIVED, G_CALLBACK(test_everything_changed), &data);
+    g_signal_connect(ndisc, NM_FAKE_NDISC_RS_SENT, G_CALLBACK(test_everything_rs_sent), &data);
+
+    nm_ndisc_start(NM_NDISC(ndisc));
+    nmtst_main_loop_run_assert(data.loop, 15000);
+    g_assert_cmpint(data.counter, ==, 2);
+    g_assert_cmpint(data.rs_counter, ==, 1);
+}
+
+static void
+test_preference_order_cb(NMNDisc *          ndisc,
+                         const NMNDiscData *rdata,
+                         guint              changed_int,
+                         TestData *         data)
+{
+    NMNDiscConfigMap changed = changed_int;
+
+    if (data->counter == 1) {
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_GATEWAYS | NM_NDISC_CONFIG_ADDRESSES
+                            | NM_NDISC_CONFIG_ROUTES);
+
+        g_assert_cmpint(rdata->gateways_n, ==, 2);
+        match_gateway(rdata,
+                      0,
+                      "fe80::1",
+                      data->timestamp_msec_1 + 10000,
+                      NM_ICMPV6_ROUTER_PREF_HIGH);
+        match_gateway(rdata,
+                      1,
+                      "fe80::2",
+                      data->timestamp_msec_1 + 11000,
+                      NM_ICMPV6_ROUTER_PREF_LOW);
+        g_assert_cmpint(rdata->addresses_n, ==, 2);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1 + 10000);
+        match_address(rdata,
+                      1,
+                      "2001:db8:a:b::1",
+                      data->timestamp_msec_1 + 11000,
+                      data->timestamp_msec_1 + 10000);
+        g_assert_cmpint(rdata->routes_n, ==, 2);
+        match_route(rdata, 0, "2001:db8:a:b::", 64, "fe80::2", data->timestamp_msec_1 + 11000, 10);
+        match_route(rdata, 1, "2001:db8:a:a::", 64, "fe80::1", data->timestamp_msec_1 + 10000, 5);
+
+        g_assert(nm_fake_ndisc_done(NM_FAKE_NDISC(ndisc)));
+        g_main_loop_quit(data->loop);
+    }
+
+    data->counter++;
+}
+
+static void
+test_preference_order(void)
+{
+    nm_auto_unref_gmainloop GMainLoop *loop = g_main_loop_new(NULL, FALSE);
+    gs_unref_object NMFakeNDisc *ndisc      = ndisc_new();
+    const gint64                 now_msec   = nm_utils_get_monotonic_timestamp_msec();
+    TestData                     data       = {
+        .loop             = loop,
+        .timestamp_msec_1 = now_msec,
+    };
+    guint id;
+
+    /* Test insertion order of gateways */
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_HIGH);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:a::",
+                             64,
+                             "fe80::1",
+                             now_msec + 10000,
+                             now_msec + 10000,
+                             5);
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::2", now_msec + 11000, NM_ICMPV6_ROUTER_PREF_LOW);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:b::",
+                             64,
+                             "fe80::2",
+                             now_msec + 11000,
+                             now_msec + 10000,
+                             10);
+
+    g_signal_connect(ndisc, NM_NDISC_CONFIG_RECEIVED, G_CALLBACK(test_preference_order_cb), &data);
+
+    nm_ndisc_start(NM_NDISC(ndisc));
+    nmtst_main_loop_run_assert(data.loop, 15000);
+    g_assert_cmpint(data.counter, ==, 2);
+}
+
+static void
+test_preference_changed_cb(NMNDisc *          ndisc,
+                           const NMNDiscData *rdata,
+                           guint              changed_int,
+                           TestData *         data)
+{
+    NMNDiscConfigMap changed = changed_int;
+
+    if (data->counter == 1) {
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_GATEWAYS | NM_NDISC_CONFIG_ADDRESSES
+                            | NM_NDISC_CONFIG_ROUTES);
+        g_assert_cmpint(rdata->gateways_n, ==, 2);
+        match_gateway(rdata,
+                      0,
+                      "fe80::2",
+                      data->timestamp_msec_1 + 11000,
+                      NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        match_gateway(rdata,
+                      1,
+                      "fe80::1",
+                      data->timestamp_msec_1 + 10000,
+                      NM_ICMPV6_ROUTER_PREF_LOW);
+        g_assert_cmpint(rdata->addresses_n, ==, 2);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 10000,
+                      data->timestamp_msec_1 + 10000);
+        match_address(rdata,
+                      1,
+                      "2001:db8:a:b::1",
+                      data->timestamp_msec_1 + 11000,
+                      data->timestamp_msec_1 + 11000);
+        g_assert_cmpint(rdata->routes_n, ==, 2);
+        match_route(rdata, 0, "2001:db8:a:b::", 64, "fe80::2", data->timestamp_msec_1 + 11000, 10);
+        match_route(rdata, 1, "2001:db8:a:a::", 64, "fe80::1", data->timestamp_msec_1 + 10000, 5);
+    } else if (data->counter == 2) {
+        g_assert_cmpint(changed,
+                        ==,
+                        NM_NDISC_CONFIG_GATEWAYS | NM_NDISC_CONFIG_ADDRESSES
+                            | NM_NDISC_CONFIG_ROUTES);
+
+        g_assert_cmpint(rdata->gateways_n, ==, 2);
+        match_gateway(rdata,
+                      0,
+                      "fe80::1",
+                      data->timestamp_msec_1 + 12000,
+                      NM_ICMPV6_ROUTER_PREF_HIGH);
+        match_gateway(rdata,
+                      1,
+                      "fe80::2",
+                      data->timestamp_msec_1 + 11000,
+                      NM_ICMPV6_ROUTER_PREF_MEDIUM);
+        g_assert_cmpint(rdata->addresses_n, ==, 2);
+        match_address(rdata,
+                      0,
+                      "2001:db8:a:a::1",
+                      data->timestamp_msec_1 + 12000,
+                      data->timestamp_msec_1 + 12000);
+        match_address(rdata,
+                      1,
+                      "2001:db8:a:b::1",
+                      data->timestamp_msec_1 + 11000,
+                      data->timestamp_msec_1 + 11000);
+        g_assert_cmpint(rdata->routes_n, ==, 2);
+        match_route(rdata, 0, "2001:db8:a:a::", 64, "fe80::1", data->timestamp_msec_1 + 12000, 15);
+        match_route(rdata, 1, "2001:db8:a:b::", 64, "fe80::2", data->timestamp_msec_1 + 11000, 10);
+
+        g_assert(nm_fake_ndisc_done(NM_FAKE_NDISC(ndisc)));
+        g_main_loop_quit(data->loop);
+    }
+
+    data->counter++;
+}
+
+static void
+test_preference_changed(void)
+{
+    nm_auto_unref_gmainloop GMainLoop *loop = g_main_loop_new(NULL, FALSE);
+    gs_unref_object NMFakeNDisc *ndisc      = ndisc_new();
+    const gint64                 now_msec   = nm_utils_get_monotonic_timestamp_msec();
+    TestData                     data       = {
+        .loop             = loop,
+        .timestamp_msec_1 = now_msec,
+    };
+    guint id;
+
+    /* Test that when a low-preference and medium gateway send advertisements,
+     * that if the low-preference gateway switches to high-preference, we do
+     * not get duplicates in the gateway list.
+     */
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_LOW);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:a::",
+                             64,
+                             "fe80::1",
+                             now_msec + 10000,
+                             now_msec + 10000,
+                             5);
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::2", now_msec + 11000, NM_ICMPV6_ROUTER_PREF_MEDIUM);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:b::",
+                             64,
+                             "fe80::2",
+                             now_msec + 11000,
+                             now_msec + 11000,
+                             10);
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 12000, NM_ICMPV6_ROUTER_PREF_HIGH);
+    nm_fake_ndisc_add_prefix(ndisc,
+                             id,
+                             "2001:db8:a:a::",
+                             64,
+                             "fe80::1",
+                             now_msec + 12000,
+                             now_msec + 12000,
+                             15);
+
+    g_signal_connect(ndisc,
+                     NM_NDISC_CONFIG_RECEIVED,
+                     G_CALLBACK(test_preference_changed_cb),
+                     &data);
+
+    nm_ndisc_start(NM_NDISC(ndisc));
+    nmtst_main_loop_run_assert(data.loop, 15000);
+    g_assert_cmpint(data.counter, ==, 3);
+}
+
+/*****************************************************************************/
+
+static void
+_test_dns_solicit_loop_changed(NMNDisc *          ndisc,
+                               const NMNDiscData *rdata,
+                               guint              changed_int,
+                               TestData *         data)
+{
+    data->counter++;
+}
+
+static void
+_test_dns_solicit_loop_rs_sent(NMFakeNDisc *ndisc, TestData *data)
+{
+    data->rs_counter++;
+}
+
+static void
+test_dns_solicit_loop(void)
+{
+    nm_auto_unref_gmainloop GMainLoop *loop = g_main_loop_new(NULL, FALSE);
+    gs_unref_object NMFakeNDisc *ndisc      = ndisc_new();
+    const gint64                 now_msec   = nm_utils_get_monotonic_timestamp_msec();
+    TestData                     data       = {
+        .loop             = loop,
+        .timestamp_msec_1 = now_msec,
+    };
+    guint id;
+
+    /* Ensure that no solicitation loop happens when DNS servers or domains
+     * stop being sent in advertisements.  This can happen if two routers
+     * send RAs, but the one sending DNS info stops responding, or if one
+     * router removes the DNS info from the RA without zero-lifetiming them
+     * first.
+     */
+
+    id = nm_fake_ndisc_add_ra(ndisc, 1, NM_NDISC_DHCP_LEVEL_NONE, 4, 1500);
+    g_assert(id);
+    nm_fake_ndisc_add_gateway(ndisc, id, "fe80::1", now_msec + 10000, NM_ICMPV6_ROUTER_PREF_LOW);
+    nm_fake_ndisc_add_dns_server(ndisc, id, "2001:db8:c:c::1", now_msec + 6000);
+
+    g_signal_connect(ndisc,
+                     NM_NDISC_CONFIG_RECEIVED,
+                     G_CALLBACK(_test_dns_solicit_loop_changed),
+                     &data);
+    g_signal_connect(ndisc,
+                     NM_FAKE_NDISC_RS_SENT,
+                     G_CALLBACK(_test_dns_solicit_loop_rs_sent),
+                     &data);
+
+    nm_ndisc_start(NM_NDISC(ndisc));
+    if (nmtst_main_loop_run(data.loop, 10000))
+        g_error("we expect to run the loop until timeout. What is wrong?");
+    g_assert_cmpint(data.counter, ==, 3);
+    g_assert_cmpint(data.rs_counter, ==, 1);
+}
+
+/*****************************************************************************/
+
+NMTST_DEFINE();
+
+int
+main(int argc, char **argv)
+{
+    nmtst_init_with_logging(&argc, &argv, NULL, "DEFAULT");
+
+    if (nmtst_test_quick()) {
+        g_print("Skipping test: don't run long running test %s (NMTST_DEBUG=slow)\n",
+                g_get_prgname() ?: "test-ndisc-fake");
+        return g_test_run();
+    }
+
+    nm_fake_platform_setup();
+
+    g_test_add_func("/ndisc/simple", test_simple);
+    g_test_add_func("/ndisc/everything-changed", test_everything);
+    g_test_add_func("/ndisc/preference-order", test_preference_order);
+    g_test_add_func("/ndisc/preference-changed", test_preference_changed);
+    g_test_add_func("/ndisc/dns-solicit-loop", test_dns_solicit_loop);
+
+    return g_test_run();
+}
diff --git a/src/core/ndisc/tests/test-ndisc-linux.c b/src/core/ndisc/tests/test-ndisc-linux.c
new file mode 100644
index 00000000..9a5df60b
--- /dev/null
+++ b/src/core/ndisc/tests/test-ndisc-linux.c
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include <syslog.h>
+
+#include "ndisc/nm-ndisc.h"
+#include "ndisc/nm-lndp-ndisc.h"
+
+#include "platform/nm-linux-platform.h"
+
+#include "nm-test-utils-core.h"
+
+NMTST_DEFINE();
+
+int
+main(int argc, char **argv)
+{
+    GMainLoop *        loop;
+    NMNDisc *          ndisc;
+    int                ifindex = 1;
+    const char *       ifname;
+    NMUtilsIPv6IfaceId iid   = {};
+    GError *           error = NULL;
+    int                max_addresses;
+    int                router_solicitations;
+    int                router_solicitation_interval;
+    guint32            ra_timeout;
+
+    nmtst_init_with_logging(&argc, &argv, NULL, "DEFAULT");
+
+    if (getuid() != 0) {
+        g_print("Missing permission: must run as root\n");
+        return EXIT_FAILURE;
+    }
+
+    loop = g_main_loop_new(NULL, FALSE);
+
+    nm_linux_platform_setup();
+
+    if (argv[1]) {
+        ifname  = argv[1];
+        ifindex = nm_platform_link_get_ifindex(NM_PLATFORM_GET, ifname);
+    } else {
+        g_print("Missing command line argument \"interface-name\"\n");
+        return EXIT_FAILURE;
+    }
+
+    nm_lndp_ndisc_get_sysctl(NM_PLATFORM_GET,
+                             ifname,
+                             &max_addresses,
+                             &router_solicitations,
+                             &router_solicitation_interval,
+                             &ra_timeout);
+
+    ndisc = nm_lndp_ndisc_new(NM_PLATFORM_GET,
+                              ifindex,
+                              ifname,
+                              NM_UTILS_STABLE_TYPE_UUID,
+                              "8ce666e8-d34d-4fb1-b858-f15a7al28086",
+                              NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE_EUI64,
+                              NM_NDISC_NODE_TYPE_HOST,
+                              max_addresses,
+                              router_solicitations,
+                              router_solicitation_interval,
+                              ra_timeout,
+                              &error);
+    if (!ndisc) {
+        g_print("Failed to create NMNDisc instance: %s\n", error->message);
+        g_error_free(error);
+        return EXIT_FAILURE;
+    }
+
+    iid.id_u8[7] = 1;
+    nm_ndisc_set_iid(ndisc, iid);
+    nm_ndisc_start(ndisc);
+    g_main_loop_run(loop);
+
+    g_clear_object(&ndisc);
+
+    return EXIT_SUCCESS;
+}