core: merge branch 'th/keyfile-db-stale-entries'

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/906

(cherry picked from commit 26f38b9ffafeab145150332f8a11eb94559c31bf)

12 files changed, 449 insertions, 114 deletions

diff --git a/src/core/main.c b/src/core/main.c
index cfcdb860dd..3cb5c07f7f 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -304,14 +304,14 @@ main(int argc, char *argv[])
     const char *const *     warnings;
     int                     errsv;
 
+    _nm_utils_is_manager_process = TRUE;
+
     /* Known to cause a possible deadlock upon GDBus initialization:
      * https://bugzilla.gnome.org/show_bug.cgi?id=674885 */
     g_type_ensure(G_TYPE_SOCKET);
     g_type_ensure(G_TYPE_DBUS_CONNECTION);
     g_type_ensure(NM_TYPE_DBUS_MANAGER);
 
-    _nm_utils_is_manager_process = TRUE;
-
     main_loop = g_main_loop_new(NULL, FALSE);
 
     /* we determine a first-start (contrary to a restart during the same boot)
diff --git a/src/core/settings/nm-settings-connection.c b/src/core/settings/nm-settings-connection.c
index 641f3297b8..36ef6acb2f 100644
--- a/src/core/settings/nm-settings-connection.c
+++ b/src/core/settings/nm-settings-connection.c
@@ -11,6 +11,7 @@
 #include "c-list/src/c-list.h"
 
 #include "libnm-glib-aux/nm-keyfile-aux.h"
+#include "libnm-glib-aux/nm-c-list.h"
 #include "libnm-core-aux-intern/nm-common-macros.h"
 #include "nm-config.h"
 #include "nm-config-data.h"
@@ -30,6 +31,8 @@
 #define AUTOCONNECT_RETRIES_FOREVER     -1
 #define AUTOCONNECT_RESET_RETRIES_TIMER 300
 
+#define SEEN_BSSIDS_MAX 30
+
 #define _NM_SETTINGS_UPDATE2_FLAG_ALL_PERSIST_MODES                          \
     ((NMSettingsUpdate2Flags) (NM_SETTINGS_UPDATE2_FLAG_TO_DISK              \
                                | NM_SETTINGS_UPDATE2_FLAG_IN_MEMORY          \
@@ -59,6 +62,56 @@ nm_settings_connections_array_to_connections(NMSettingsConnection *const *connec
 
 /*****************************************************************************/
 
+typedef struct {
+    char  bssid[sizeof(NMEtherAddr) * 3];
+    CList seen_bssids_lst;
+} SeenBssidEntry;
+
+static inline SeenBssidEntry *
+_seen_bssid_entry_init_stale(SeenBssidEntry *entry, const NMEtherAddr *bssid_bin)
+{
+    _nm_utils_hwaddr_ntoa(bssid_bin, sizeof(NMEtherAddr), TRUE, entry->bssid, sizeof(entry->bssid));
+    return entry;
+}
+
+static inline SeenBssidEntry *
+_seen_bssid_entry_new_stale_bin(const NMEtherAddr *bssid_bin)
+{
+    return _seen_bssid_entry_init_stale(g_slice_new(SeenBssidEntry), bssid_bin);
+}
+
+static inline SeenBssidEntry *
+_seen_bssid_entry_new_stale_copy(const SeenBssidEntry *src)
+{
+    SeenBssidEntry *entry;
+
+    entry = g_slice_new(SeenBssidEntry);
+    memcpy(entry->bssid, src->bssid, sizeof(entry->bssid));
+    return entry;
+}
+
+static void
+_seen_bssid_entry_free(gpointer data)
+{
+    SeenBssidEntry *entry = data;
+
+    c_list_unlink_stale(&entry->seen_bssids_lst);
+    nm_g_slice_free(entry);
+}
+
+/*****************************************************************************/
+
+static GHashTable *
+_seen_bssids_hash_new(void)
+{
+    return g_hash_table_new_full(nm_str_hash,
+                                 g_str_equal,
+                                 (GDestroyNotify) _seen_bssid_entry_free,
+                                 NULL);
+}
+
+/*****************************************************************************/
+
 NM_GOBJECT_PROPERTIES_DEFINE(NMSettingsConnection, PROP_UNSAVED, PROP_FLAGS, PROP_FILENAME, );
 
 enum { UPDATED_INTERNAL, FLAGS_CHANGED, LAST_SIGNAL };
@@ -99,7 +152,8 @@ typedef struct _NMSettingsConnectionPrivate {
      */
     GVariant *agent_secrets;
 
-    GHashTable *seen_bssids; /* Up-to-date BSSIDs that's been seen for the connection */
+    CList       seen_bssids_lst_head;
+    GHashTable *seen_bssids_hash;
 
     guint64 timestamp; /* Up-to-date timestamp of connection use */
 
@@ -167,7 +221,9 @@ static const GDBusSignalInfo             signal_info_updated;
 static const GDBusSignalInfo             signal_info_removed;
 static const NMDBusInterfaceInfoExtended interface_info_settings_connection;
 
-static void update_agent_secrets_cache(NMSettingsConnection *self, NMConnection *new);
+static void  update_agent_secrets_cache(NMSettingsConnection *self, NMConnection *new);
+static guint _get_seen_bssids(NMSettingsConnection *self,
+                              const char *          strv_buf[static(SEEN_BSSIDS_MAX + 1)]);
 
 /*****************************************************************************/
 
@@ -246,14 +302,6 @@ nm_settings_connection_still_valid(NMSettingsConnection *self)
 
 /*****************************************************************************/
 
-static GHashTable *
-_seen_bssids_hash_new(void)
-{
-    return g_hash_table_new_full(nm_str_hash, g_str_equal, g_free, NULL);
-}
-
-/*****************************************************************************/
-
 static void
 _getsettings_cached_clear(NMSettingsConnectionPrivate *priv)
 {
@@ -1300,8 +1348,8 @@ get_settings_auth_cb(NMSettingsConnection * self,
                      GError *               error,
                      gpointer               data)
 {
-    gs_free const char **            seen_bssids = NULL;
-    NMConnectionSerializationOptions options     = {};
+    const char *                     seen_bssids_strv[SEEN_BSSIDS_MAX + 1];
+    NMConnectionSerializationOptions options = {};
 
     if (error) {
         g_dbus_method_invocation_return_gerror(context, error);
@@ -1321,8 +1369,8 @@ get_settings_auth_cb(NMSettingsConnection * self,
      * from the same reason as timestamp. Thus we put it here to GetSettings()
      * return settings too.
      */
-    seen_bssids         = nm_settings_connection_get_seen_bssids(self);
-    options.seen_bssids = seen_bssids;
+    _get_seen_bssids(self, seen_bssids_strv);
+    options.seen_bssids = seen_bssids_strv;
 
     /* Secrets should *never* be returned by the GetSettings method, they
      * get returned by the GetSecrets method which can be better
@@ -2304,68 +2352,66 @@ _nm_settings_connection_register_kf_dbs(NMSettingsConnection *self,
 
     if (priv->kf_db_seen_bssids != kf_db_seen_bssids) {
         gs_strfreev char **tmp_strv = NULL;
-        gsize              i, len;
+        gsize              len;
+        gsize              i;
+        guint              result_len;
 
         nm_key_file_db_unref(priv->kf_db_seen_bssids);
         priv->kf_db_seen_bssids = nm_key_file_db_ref(kf_db_seen_bssids);
 
         tmp_strv = nm_key_file_db_get_string_list(priv->kf_db_seen_bssids, connection_uuid, &len);
 
-        nm_clear_pointer(&priv->seen_bssids, g_hash_table_unref);
+        if (priv->seen_bssids_hash)
+            g_hash_table_remove_all(priv->seen_bssids_hash);
 
-        if (len > 0) {
-            _LOGT("read %zu seen-bssids from keyfile database \"%s\"",
-                  len,
-                  nm_key_file_db_get_filename(priv->kf_db_seen_bssids));
-            priv->seen_bssids = _seen_bssids_hash_new();
-            for (i = len; i > 0;)
-                g_hash_table_add(priv->seen_bssids, g_steal_pointer(&tmp_strv[--i]));
-            nm_clear_g_free(&tmp_strv);
-        } else {
-            NMSettingWireless *s_wifi;
+        for (result_len = 0, i = 0; i < len; i++) {
+            NMEtherAddr     addr_bin;
+            SeenBssidEntry *entry;
 
-            _LOGT("no seen-bssids from keyfile database \"%s\"",
-                  nm_key_file_db_get_filename(priv->kf_db_seen_bssids));
+            nm_assert(result_len == nm_g_hash_table_size(priv->seen_bssids_hash));
+            if (result_len >= SEEN_BSSIDS_MAX)
+                break;
 
-            /* If this connection didn't have an entry in the seen-bssids database,
-             * maybe this is the first time we've read it in, so populate the
-             * seen-bssids list from the deprecated seen-bssids property of the
-             * wifi setting.
-             */
-            s_wifi =
-                nm_connection_get_setting_wireless(nm_settings_connection_get_connection(self));
-            if (s_wifi) {
-                len = nm_setting_wireless_get_num_seen_bssids(s_wifi);
-                if (len > 0) {
-                    priv->seen_bssids = _seen_bssids_hash_new();
-                    for (i = 0; i < len; i++) {
-                        const char *bssid = nm_setting_wireless_get_seen_bssid(s_wifi, i);
-
-                        g_hash_table_add(priv->seen_bssids, g_strdup(bssid));
-                    }
-                }
+            if (!_nm_utils_hwaddr_aton_exact(tmp_strv[i], &addr_bin, sizeof(addr_bin)))
+                continue;
+
+            if (!priv->seen_bssids_hash)
+                priv->seen_bssids_hash = _seen_bssids_hash_new();
+
+            entry = _seen_bssid_entry_new_stale_bin(&addr_bin);
+            if (!g_hash_table_insert(priv->seen_bssids_hash, entry, entry)) {
+                /* duplicate detected! The @entry key was freed by g_hash_table_insert(). */
+                continue;
             }
+            c_list_link_tail(&priv->seen_bssids_lst_head, &entry->seen_bssids_lst);
+            result_len++;
         }
+        if (result_len > 0) {
+            _LOGT("read %u seen-bssids from keyfile database \"%s\"",
+                  result_len,
+                  nm_key_file_db_get_filename(priv->kf_db_seen_bssids));
+        } else
+            nm_clear_pointer(&priv->seen_bssids_hash, g_hash_table_destroy);
+
+        nm_assert(nm_g_hash_table_size(priv->seen_bssids_hash) == result_len);
+        nm_assert(result_len <= SEEN_BSSIDS_MAX);
     }
 }
 
-/**
- * nm_settings_connection_get_seen_bssids:
- * @self: the #NMSettingsConnection
- *
- * Returns current list of seen BSSIDs for the connection.
- *
- * Returns: (transfer container) list of seen BSSIDs (in the standard hex-digits-and-colons notation).
- * The caller is responsible for freeing the list, but not the content.
- **/
-const char **
-nm_settings_connection_get_seen_bssids(NMSettingsConnection *self)
+static guint
+_get_seen_bssids(NMSettingsConnection *self, const char *strv_buf[static(SEEN_BSSIDS_MAX + 1)])
 {
-    g_return_val_if_fail(NM_IS_SETTINGS_CONNECTION(self), NULL);
+    NMSettingsConnectionPrivate *priv = NM_SETTINGS_CONNECTION_GET_PRIVATE(self);
+    SeenBssidEntry *             entry;
+    guint                        i;
 
-    return nm_utils_strdict_get_keys(NM_SETTINGS_CONNECTION_GET_PRIVATE(self)->seen_bssids,
-                                     TRUE,
-                                     NULL);
+    i = 0;
+    c_list_for_each_entry (entry, &priv->seen_bssids_lst_head, seen_bssids_lst) {
+        nm_assert(i <= SEEN_BSSIDS_MAX);
+        strv_buf[i++] = entry->bssid;
+    }
+    strv_buf[i] = NULL;
+    return i;
 }
 
 /**
@@ -2379,14 +2425,17 @@ gboolean
 nm_settings_connection_has_seen_bssid(NMSettingsConnection *self, const char *bssid)
 {
     NMSettingsConnectionPrivate *priv;
+    NMEtherAddr                  addr_bin;
 
     g_return_val_if_fail(NM_IS_SETTINGS_CONNECTION(self), FALSE);
     g_return_val_if_fail(bssid, FALSE);
+    nm_assert(_nm_utils_hwaddr_aton_exact(bssid, &addr_bin, sizeof(addr_bin)));
 
     priv = NM_SETTINGS_CONNECTION_GET_PRIVATE(self);
 
-    return priv->seen_bssids
-           && g_hash_table_contains(NM_SETTINGS_CONNECTION_GET_PRIVATE(self)->seen_bssids, bssid);
+    return priv->seen_bssids_hash
+           && g_hash_table_contains(NM_SETTINGS_CONNECTION_GET_PRIVATE(self)->seen_bssids_hash,
+                                    bssid);
 }
 
 /**
@@ -2401,15 +2450,47 @@ void
 nm_settings_connection_add_seen_bssid(NMSettingsConnection *self, const char *seen_bssid)
 {
     NMSettingsConnectionPrivate *priv = NM_SETTINGS_CONNECTION_GET_PRIVATE(self);
-    gs_free const char **        strv = NULL;
+    const char *                 seen_bssids_strv[SEEN_BSSIDS_MAX + 1];
+    NMEtherAddr                  addr_bin;
     const char *                 connection_uuid;
+    SeenBssidEntry               entry_stack;
+    SeenBssidEntry *             entry;
+    guint                        i;
+
+    g_return_if_fail(seen_bssid);
 
-    g_return_if_fail(seen_bssid != NULL);
+    if (!_nm_utils_hwaddr_aton_exact(seen_bssid, &addr_bin, sizeof(addr_bin)))
+        g_return_if_reached();
 
-    if (!priv->seen_bssids)
-        priv->seen_bssids = _seen_bssids_hash_new();
+    _seen_bssid_entry_init_stale(&entry_stack, &addr_bin);
 
-    g_hash_table_add(priv->seen_bssids, g_strdup(seen_bssid));
+    if (!priv->seen_bssids_hash) {
+        priv->seen_bssids_hash = _seen_bssids_hash_new();
+        entry                  = NULL;
+    } else
+        entry = g_hash_table_lookup(priv->seen_bssids_hash, &entry_stack);
+
+    if (entry) {
+        if (!nm_c_list_move_front(&priv->seen_bssids_lst_head, &entry->seen_bssids_lst)) {
+            /* no change. */
+            return;
+        }
+    } else {
+        entry = _seen_bssid_entry_new_stale_copy(&entry_stack);
+        c_list_link_front(&priv->seen_bssids_lst_head, &entry->seen_bssids_lst);
+        if (!g_hash_table_add(priv->seen_bssids_hash, entry))
+            nm_assert_not_reached();
+
+        if (g_hash_table_size(priv->seen_bssids_hash) > SEEN_BSSIDS_MAX) {
+            g_hash_table_remove(
+                priv->seen_bssids_hash,
+                c_list_last_entry(&priv->seen_bssids_lst_head, SeenBssidEntry, seen_bssids_lst));
+        }
+    }
+
+    nm_assert(g_hash_table_size(priv->seen_bssids_hash) <= SEEN_BSSIDS_MAX);
+    nm_assert(g_hash_table_size(priv->seen_bssids_hash)
+              == c_list_length(&priv->seen_bssids_lst_head));
 
     if (!priv->kf_db_seen_bssids)
         return;
@@ -2418,12 +2499,8 @@ nm_settings_connection_add_seen_bssid(NMSettingsConnection *self, const char *se
     if (!connection_uuid)
         return;
 
-    strv = nm_utils_strdict_get_keys(priv->seen_bssids, TRUE, NULL);
-
-    nm_key_file_db_set_string_list(priv->kf_db_seen_bssids,
-                                   connection_uuid,
-                                   strv ?: NM_PTRARRAY_EMPTY(const char *),
-                                   -1);
+    i = _get_seen_bssids(self, seen_bssids_strv);
+    nm_key_file_db_set_string_list(priv->kf_db_seen_bssids, connection_uuid, seen_bssids_strv, i);
 }
 
 /*****************************************************************************/
@@ -2634,7 +2711,7 @@ nm_settings_connection_init(NMSettingsConnection *self)
     self->_priv = priv;
 
     c_list_init(&self->_connections_lst);
-
+    c_list_init(&priv->seen_bssids_lst_head);
     c_list_init(&priv->call_ids_lst_head);
     c_list_init(&priv->auth_lst_head);
 
@@ -2672,7 +2749,7 @@ dispose(GObject *object)
 
     nm_clear_pointer(&priv->agent_secrets, g_variant_unref);
 
-    nm_clear_pointer(&priv->seen_bssids, g_hash_table_destroy);
+    nm_clear_pointer(&priv->seen_bssids_hash, g_hash_table_destroy);
 
     g_clear_object(&priv->agent_mgr);
 
diff --git a/src/core/settings/nm-settings-connection.h b/src/core/settings/nm-settings-connection.h
index 83a6a7f62b..fa3dbcfbcf 100644
--- a/src/core/settings/nm-settings-connection.h
+++ b/src/core/settings/nm-settings-connection.h
@@ -340,8 +340,6 @@ gboolean nm_settings_connection_get_timestamp(NMSettingsConnection *self, guint6
 
 void nm_settings_connection_update_timestamp(NMSettingsConnection *self, guint64 timestamp);
 
-const char **nm_settings_connection_get_seen_bssids(NMSettingsConnection *self);
-
 gboolean nm_settings_connection_has_seen_bssid(NMSettingsConnection *self, const char *bssid);
 
 void nm_settings_connection_add_seen_bssid(NMSettingsConnection *self, const char *seen_bssid);
diff --git a/src/core/settings/nm-settings.c b/src/core/settings/nm-settings.c
index c876ea148c..a81f76b539 100644
--- a/src/core/settings/nm-settings.c
+++ b/src/core/settings/nm-settings.c
@@ -388,6 +388,9 @@ typedef struct {
     guint kf_db_flush_idle_id_timestamps;
     guint kf_db_flush_idle_id_seen_bssids;
 
+    bool kf_db_pruned_timestamps;
+    bool kf_db_pruned_seen_bssid;
+
     bool started : 1;
 
     /* Whether NMSettingsConnections changed in a way that affects the comparison
@@ -3684,6 +3687,41 @@ again:
 
 /*****************************************************************************/
 
+static gboolean
+_kf_db_prune_predicate(const char *uuid, gpointer user_data)
+{
+    return !!nm_settings_get_connection_by_uuid(user_data, uuid);
+}
+
+static void
+_kf_db_to_file(NMSettings *self, gboolean is_timestamps, gboolean force_write)
+{
+    NMSettingsPrivate *priv = NM_SETTINGS_GET_PRIVATE(self);
+    NMKeyFileDB *      kf_db;
+    bool *             p_kf_db_pruned;
+
+    if (is_timestamps) {
+        kf_db          = priv->kf_db_timestamps;
+        p_kf_db_pruned = &priv->kf_db_pruned_timestamps;
+    } else {
+        kf_db          = priv->kf_db_seen_bssids;
+        p_kf_db_pruned = &priv->kf_db_pruned_seen_bssid;
+    }
+
+    if (!*p_kf_db_pruned) {
+        /* we only prune the DB once, because afterwards every
+         * add/remove of an connection will lead to a direct update. */
+        *p_kf_db_pruned = TRUE;
+        nm_key_file_db_prune(kf_db, _kf_db_prune_predicate, self);
+
+        /* once we also go over the directory, and see whether we
+         * have any left over temporary files to delete. */
+        nm_key_file_db_prune_tmp_files(kf_db);
+    }
+
+    nm_key_file_db_to_file(kf_db, force_write);
+}
+
 G_GNUC_PRINTF(4, 5)
 static void
 _kf_db_log_fcn(NMKeyFileDB *kf_db, int syslog_level, gpointer user_data, const char *fmt, ...)
@@ -3732,7 +3770,7 @@ _kf_db_got_dirty_flush(NMSettings *self, gboolean is_timestamps)
     }
 
     if (nm_key_file_db_is_dirty(kf_db))
-        nm_key_file_db_to_file(kf_db, FALSE);
+        _kf_db_to_file(self, is_timestamps, FALSE);
     else {
         _LOGT("[%s-keyfile]: skip saving changes to \"%s\"",
               prefix,
@@ -3785,15 +3823,10 @@ _kf_db_got_dirty_fcn(NMKeyFileDB *kf_db, gpointer user_data)
 void
 nm_settings_kf_db_write(NMSettings *self)
 {
-    NMSettingsPrivate *priv;
-
     g_return_if_fail(NM_IS_SETTINGS(self));
 
-    priv = NM_SETTINGS_GET_PRIVATE(self);
-    if (priv->kf_db_timestamps)
-        nm_key_file_db_to_file(priv->kf_db_timestamps, TRUE);
-    if (priv->kf_db_seen_bssids)
-        nm_key_file_db_to_file(priv->kf_db_seen_bssids, TRUE);
+    _kf_db_to_file(self, TRUE, TRUE);
+    _kf_db_to_file(self, FALSE, TRUE);
 }
 
 /*****************************************************************************/
@@ -4031,8 +4064,8 @@ finalize(GObject *object)
 
     nm_clear_g_source(&priv->kf_db_flush_idle_id_timestamps);
     nm_clear_g_source(&priv->kf_db_flush_idle_id_seen_bssids);
-    nm_key_file_db_to_file(priv->kf_db_timestamps, FALSE);
-    nm_key_file_db_to_file(priv->kf_db_seen_bssids, FALSE);
+    _kf_db_to_file(self, TRUE, FALSE);
+    _kf_db_to_file(self, FALSE, FALSE);
     nm_key_file_db_destroy(priv->kf_db_timestamps);
     nm_key_file_db_destroy(priv->kf_db_seen_bssids);
 
diff --git a/src/libnm-core-impl/nm-keyfile.c b/src/libnm-core-impl/nm-keyfile.c
index 88aa0d46cd..c6c4a2eb57 100644
--- a/src/libnm-core-impl/nm-keyfile.c
+++ b/src/libnm-core-impl/nm-keyfile.c
@@ -2781,6 +2781,9 @@ static const ParseInfoSetting *const parse_infos[_NM_META_SETTING_TYPE_NUM] = {
                                 .parser = mac_address_parser_ETHER_cloned, ),
             PARSE_INFO_PROPERTY(NM_SETTING_WIRELESS_MAC_ADDRESS,
                                 .parser = mac_address_parser_ETHER, ),
+            PARSE_INFO_PROPERTY(NM_SETTING_WIRELESS_SEEN_BSSIDS,
+                                .parser_skip = TRUE,
+                                .writer_skip = TRUE, ),
             PARSE_INFO_PROPERTY(NM_SETTING_WIRELESS_SSID,
                                 .parser = ssid_parser,
                                 .writer = ssid_writer, ), ), ),
diff --git a/src/libnm-core-impl/nm-setting-wireless.c b/src/libnm-core-impl/nm-setting-wireless.c
index 111116965a..5bdedf9bfb 100644
--- a/src/libnm-core-impl/nm-setting-wireless.c
+++ b/src/libnm-core-impl/nm-setting-wireless.c
@@ -750,19 +750,54 @@ _to_dbus_fcn_seen_bssids(const NMSettInfoSetting *               sett_info,
                          NMConnectionSerializationFlags          flags,
                          const NMConnectionSerializationOptions *options)
 {
+    if (options && options->seen_bssids)
+        return options->seen_bssids[0] ? g_variant_new_strv(options->seen_bssids, -1) : NULL;
+
+    /* The seen-bssid property is special. It cannot be converted to D-Bus
+     * like regular properties, only via the "options".
+     *
+     * This basically means, that only the daemon can provide seen-bssids as GVariant,
+     * while when a client converts the property to GVariant, it gets lost.
+     *
+     * This has the odd effect, that when the client converts the setting to GVariant
+     * and back, the seen-bssids gets lost. That is kinda desired here, because the to_dbus_fcn()
+     * and from_dbus_fcn() have the meaning of how a setting gets transferred via D-Bus,
+     * and not necessarily a loss-less conversion into another format and back. And when
+     * transferring via D-Bus, then the option makes only sense when sending it from
+     * the daemon to the client, not otherwise. */
+    return NULL;
+}
+
+static gboolean
+_from_dbus_fcn_seen_bssids(NMSetting *         setting,
+                           GVariant *          connection_dict,
+                           const char *        property,
+                           GVariant *          value,
+                           NMSettingParseFlags parse_flags,
+                           GError **           error)
+{
     NMSettingWirelessPrivate *priv;
+    gs_free const char **     s = NULL;
+    gsize                     len;
+    gsize                     i;
 
-    if (options && options->seen_bssids) {
-        return options->seen_bssids[0] ? g_variant_new_strv(options->seen_bssids, -1) : NULL;
+    if (_nm_utils_is_manager_process) {
+        /* in the manager process, we don't accept seen-bssid from the client.
+         * Do nothing.  */
+        return TRUE;
     }
 
     priv = NM_SETTING_WIRELESS_GET_PRIVATE(setting);
 
-    if (!priv->seen_bssids || priv->seen_bssids->len == 0)
-        return NULL;
+    nm_clear_pointer(&priv->seen_bssids, g_ptr_array_unref);
 
-    return g_variant_new_strv((const char *const *) priv->seen_bssids->pdata,
-                              priv->seen_bssids->len);
+    s = g_variant_get_strv(value, &len);
+    if (len > 0) {
+        priv->seen_bssids = g_ptr_array_new_full(len, g_free);
+        for (i = 0; i < len; i++)
+            g_ptr_array_add(priv->seen_bssids, g_strdup(s[i]));
+    }
+    return TRUE;
 }
 
 /**
@@ -1075,12 +1110,18 @@ compare_property(const NMSettInfoSetting *sett_info,
                  NMSetting *              set_b,
                  NMSettingCompareFlags    flags)
 {
-    if (nm_streq(sett_info->property_infos[property_idx].name,
-                 NM_SETTING_WIRELESS_CLONED_MAC_ADDRESS)) {
+    if (sett_info->property_infos[property_idx].param_spec
+        == obj_properties[PROP_CLONED_MAC_ADDRESS]) {
         return !set_b
                || nm_streq0(NM_SETTING_WIRELESS_GET_PRIVATE(set_a)->cloned_mac_address,
                             NM_SETTING_WIRELESS_GET_PRIVATE(set_b)->cloned_mac_address);
     }
+    if (sett_info->property_infos[property_idx].param_spec == obj_properties[PROP_SEEN_BSSIDS]) {
+        return !set_b
+               || (nm_strv_ptrarray_cmp(NM_SETTING_WIRELESS_GET_PRIVATE(set_a)->seen_bssids,
+                                        NM_SETTING_WIRELESS_GET_PRIVATE(set_b)->seen_bssids)
+                   == 0);
+    }
 
     return NM_SETTING_CLASS(nm_setting_wireless_parent_class)
         ->compare_property(sett_info, property_idx, con_a, set_a, con_b, set_b, flags);
@@ -1744,7 +1785,8 @@ nm_setting_wireless_class_init(NMSettingWirelessClass *klass)
         properties_override,
         obj_properties[PROP_SEEN_BSSIDS],
         NM_SETT_INFO_PROPERT_TYPE_DBUS(G_VARIANT_TYPE_STRING_ARRAY,
-                                       .to_dbus_fcn = _to_dbus_fcn_seen_bssids, ));
+                                       .to_dbus_fcn   = _to_dbus_fcn_seen_bssids,
+                                       .from_dbus_fcn = _from_dbus_fcn_seen_bssids, ));
 
     /**
      * NMSettingWireless:mtu:
diff --git a/src/libnm-glib-aux/nm-io-utils.c b/src/libnm-glib-aux/nm-io-utils.c
index 894c8726c0..87478a2dc2 100644
--- a/src/libnm-glib-aux/nm-io-utils.c
+++ b/src/libnm-glib-aux/nm-io-utils.c
@@ -564,3 +564,67 @@ nm_g_subprocess_terminate_in_background(GSubprocess *subprocess, int timeout_mse
                                                    NULL),
                            main_context);
 }
+
+/*****************************************************************************/
+
+char **
+nm_utils_find_mkstemp_files(const char *dirname, const char *filename)
+{
+    static const char letters[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+    DIR *             dir;
+    struct dirent *   entry;
+    GPtrArray *       arr = NULL;
+    gsize             l;
+
+    /* We write files with g_file_set_contents() and nm_utils_file_set_contents().
+     * These create temporary files using g_mkstemp_full(), with a random .XXXXXX suffix.
+     *
+     * If NetworkManager crashes while writing the file, then those temporary files are
+     * left over. We might want to find and delete such files.
+     *
+     * Beware: only delete such files if you are in full control about which files are
+     * supposed to be in the directory. For example, NetworkManager controls
+     * /var/lib/NetworkManager/timestamps files, and it thus takes the right to delete
+     * all files /var/lib/NetworkManager/timestamps.XXXXXX. That may not be appropriate
+     * in other cases! */
+
+    if (!dirname || !filename || !filename[0])
+        return NULL;
+
+    dir = opendir(dirname);
+    if (!dir)
+        return NULL;
+
+    l = strlen(filename);
+
+    while ((entry = readdir(dir))) {
+        const char *f = entry->d_name;
+        guint       i;
+
+        if (strncmp(f, filename, l) != 0)
+            goto next;
+        if (f[l] != '.')
+            goto next;
+        for (i = 1; i <= 6; i++) {
+            /* @letters is also what g_mkstemp_full() does! */
+            if (!memchr(letters, f[l + i], G_N_ELEMENTS(letters)))
+                goto next;
+        }
+        if (f[l + 7] != '\0')
+            goto next;
+
+        if (!arr)
+            arr = g_ptr_array_new();
+
+        g_ptr_array_add(arr, g_strdup(f));
+next:;
+    }
+
+    closedir(dir);
+
+    if (!arr)
+        return NULL;
+
+    g_ptr_array_add(arr, NULL);
+    return (char **) g_ptr_array_free(arr, FALSE);
+}
diff --git a/src/libnm-glib-aux/nm-io-utils.h b/src/libnm-glib-aux/nm-io-utils.h
index 98e63ac01e..31ff6d0569 100644
--- a/src/libnm-glib-aux/nm-io-utils.h
+++ b/src/libnm-glib-aux/nm-io-utils.h
@@ -58,4 +58,6 @@ int nm_utils_file_stat(const char *filename, struct stat *out_st);
 
 void nm_g_subprocess_terminate_in_background(GSubprocess *subprocess, int timeout_msec_before_kill);
 
+char **nm_utils_find_mkstemp_files(const char *dirname, const char *filename);
+
 #endif /* __NM_IO_UTILS_H__ */
diff --git a/src/libnm-glib-aux/nm-keyfile-aux.c b/src/libnm-glib-aux/nm-keyfile-aux.c
index 75abe53848..9cda1cf714 100644
--- a/src/libnm-glib-aux/nm-keyfile-aux.c
+++ b/src/libnm-glib-aux/nm-keyfile-aux.c
@@ -27,6 +27,8 @@ struct _NMKeyFileDB {
     bool dirty : 1;
     bool destroyed : 1;
 
+    bool groups_pruned : 1;
+
     char filename[];
 };
 
@@ -62,6 +64,16 @@ _IS_KEY_FILE_DB(NMKeyFileDB *self, gboolean require_is_started, gboolean allow_d
     return TRUE;
 }
 
+static GKeyFile *
+_key_file_new(void)
+{
+    GKeyFile *kf;
+
+    kf = g_key_file_new();
+    g_key_file_set_list_separator(kf, ',');
+    return kf;
+}
+
 /*****************************************************************************/
 
 NMKeyFileDB *
@@ -86,8 +98,7 @@ nm_key_file_db_new(const char *           filename,
     self->log_fcn       = log_fcn;
     self->got_dirty_fcn = got_dirty_fcn;
     self->user_data     = user_data;
-    self->kf            = g_key_file_new();
-    g_key_file_set_list_separator(self->kf, ',');
+    self->kf            = _key_file_new();
     memcpy(self->filename, filename, l_filename + 1);
     self->group_name = &self->filename[l_filename + 1];
     memcpy((char *) self->group_name, group_name, l_group + 1);
@@ -371,3 +382,106 @@ nm_key_file_db_to_file(NMKeyFileDB *self, gboolean force)
     } else
         _LOGD("write keyfile: \"%s\"", self->filename);
 }
+
+/*****************************************************************************/
+
+void
+nm_key_file_db_prune_tmp_files(NMKeyFileDB *self)
+{
+    gs_free char *     n_file   = NULL;
+    gs_free char *     n_dir    = NULL;
+    gs_strfreev char **tmpfiles = NULL;
+    gsize              i;
+
+    n_file = g_path_get_basename(self->filename);
+    n_dir  = g_path_get_dirname(self->filename);
+
+    tmpfiles = nm_utils_find_mkstemp_files(n_dir, n_file);
+    if (!tmpfiles)
+        return;
+
+    for (i = 0; tmpfiles[i]; i++) {
+        const char *  tmpfile   = tmpfiles[i];
+        gs_free char *full_file = NULL;
+        int           r;
+
+        full_file = g_strdup_printf("%s/%s", n_dir, tmpfile);
+
+        r = unlink(full_file);
+        if (r != 0) {
+            int errsv = errno;
+
+            if (errsv != ENOENT) {
+                _LOGD("prune left over temp file %s failed: %s",
+                      full_file,
+                      nm_strerror_native(errsv));
+            }
+            continue;
+        }
+
+        _LOGD("prune left over temp file %s", full_file);
+    }
+}
+
+/*****************************************************************************/
+
+void
+nm_key_file_db_prune(NMKeyFileDB *self,
+                     gboolean (*predicate)(const char *key, gpointer user_data),
+                     gpointer user_data)
+{
+    gs_strfreev char **   keys                 = NULL;
+    nm_auto_unref_keyfile GKeyFile *kf_to_free = NULL;
+    GKeyFile *                      kf_src     = NULL;
+    GKeyFile *                      kf_dst     = NULL;
+    guint                           k;
+
+    g_return_if_fail(_IS_KEY_FILE_DB(self, TRUE, FALSE));
+    nm_assert(predicate);
+
+    _LOGD("prune keyfile of old entries: \"%s\"", self->filename);
+
+    if (!self->groups_pruned) {
+        /* When we prune the first time, we swap the GKeyfile instance.
+         * The instance loaded from disk might have unrelated groups and
+         * comments. Let's get rid of them by creating a new instance.
+         *
+         * Otherwise, we know that self->kf only contains good keys,
+         * and at most we need to remove some of them. */
+        kf_to_free          = g_steal_pointer(&self->kf);
+        self->kf            = _key_file_new();
+        kf_src              = kf_to_free;
+        self->groups_pruned = TRUE;
+        self->dirty         = TRUE;
+    } else
+        kf_src = self->kf;
+    kf_dst = self->kf;
+
+    keys = g_key_file_get_keys(kf_src, self->group_name, NULL, NULL);
+    if (keys) {
+        for (k = 0; keys[k]; k++) {
+            const char *key = keys[k];
+            gboolean    keep;
+
+            keep = predicate(key, user_data);
+
+            if (!keep) {
+                if (kf_dst == kf_src) {
+                    g_key_file_remove_key(kf_dst, self->group_name, key, NULL);
+                    self->dirty = TRUE;
+                }
+                continue;
+            }
+
+            if (kf_dst != kf_src) {
+                gs_free char *value = NULL;
+
+                value = g_key_file_get_value(kf_src, self->group_name, key, NULL);
+                if (value)
+                    g_key_file_set_value(kf_dst, self->group_name, key, value);
+                else
+                    self->dirty = TRUE;
+            }
+        }
+    }
+}
diff --git a/src/libnm-glib-aux/nm-keyfile-aux.h b/src/libnm-glib-aux/nm-keyfile-aux.h
index 72d2f418f9..e756c57a84 100644
--- a/src/libnm-glib-aux/nm-keyfile-aux.h
+++ b/src/libnm-glib-aux/nm-keyfile-aux.h
@@ -50,6 +50,12 @@ void nm_key_file_db_set_string_list(NMKeyFileDB *      self,
 
 void nm_key_file_db_to_file(NMKeyFileDB *self, gboolean force);
 
+void nm_key_file_db_prune_tmp_files(NMKeyFileDB *self);
+
+void nm_key_file_db_prune(NMKeyFileDB *self,
+                          gboolean (*predicate)(const char *key, gpointer user_data),
+                          gpointer user_data);
+
 /*****************************************************************************/
 
 #endif /* __NM_KEYFILE_AUX_H__ */
diff --git a/src/libnm-glib-aux/nm-macros-internal.h b/src/libnm-glib-aux/nm-macros-internal.h
index 39197ecf3a..f2d81e1ccf 100644
--- a/src/libnm-glib-aux/nm-macros-internal.h
+++ b/src/libnm-glib-aux/nm-macros-internal.h
@@ -121,14 +121,6 @@ _nm_auto_free_gstring(GString **str)
 }
 #define nm_auto_free_gstring nm_auto(_nm_auto_free_gstring)
 
-static inline void
-_nm_auto_protect_errno(const int *p_saved_errno)
-{
-    errno = *p_saved_errno;
-}
-#define NM_AUTO_PROTECT_ERRNO(errsv_saved) \
-    nm_auto(_nm_auto_protect_errno) _nm_unused const int errsv_saved = (errno)
-
 NM_AUTO_DEFINE_FCN0(GSource *, _nm_auto_unref_gsource, g_source_unref);
 #define nm_auto_unref_gsource nm_auto(_nm_auto_unref_gsource)
 
diff --git a/src/libnm-std-aux/nm-std-aux.h b/src/libnm-std-aux/nm-std-aux.h
index b153866fd8..17b268816d 100644
--- a/src/libnm-std-aux/nm-std-aux.h
+++ b/src/libnm-std-aux/nm-std-aux.h
@@ -695,16 +695,22 @@ nm_close(int fd)
 NM_AUTO_DEFINE_FCN_VOID0(void *, _nm_auto_free_impl, free);
 #define nm_auto_free nm_auto(_nm_auto_free_impl)
 
+static inline void
+_nm_auto_protect_errno(const int *p_saved_errno)
+{
+    errno = *p_saved_errno;
+}
+#define NM_AUTO_PROTECT_ERRNO(errsv_saved) \
+    nm_auto(_nm_auto_protect_errno) _nm_unused const int errsv_saved = (errno)
+
 /*****************************************************************************/
 
 static inline void
 _nm_auto_close(int *pfd)
 {
     if (*pfd >= 0) {
-        int errsv = errno;
-
+        NM_AUTO_PROTECT_ERRNO(errsv);
         (void) nm_close(*pfd);
-        errno = errsv;
     }
 }
 #define nm_auto_close nm_auto(_nm_auto_close)
@@ -713,10 +719,8 @@ static inline void
 _nm_auto_fclose(FILE **pfd)
 {
     if (*pfd) {
-        int errsv = errno;
-
+        NM_AUTO_PROTECT_ERRNO(errsv);
         (void) fclose(*pfd);
-        errno = errsv;
     }
 }
 #define nm_auto_fclose nm_auto(_nm_auto_fclose)