core: config: allow to store 'managed' configs to NM-intern

To support setting devices as managed or unmanaged via D-Bus API in a
permanent way, we need a way to store this configuration on disk. Before
this commit, only config files manually edited allowed it. Following
commits will make use of the new functions to store [device-*] sections
into NetworkManager-intern.conf depending on D-Bus method invocations.

src/core/nm-config.c

@@ -2076,6 +2076,130 @@ nm_config_set_connectivity_check_enabled(NMConfig *self, gboolean enabled)
     g_key_file_unref(keyfile);
 }
 
+/*****************************************************************************/
+
+/**
+ * nm_config_get_device_managed:
+ * @self: the NMConfig instance
+ * @ifname: the interface name
+ *
+ * Returns: the current managed state of the device in the intern keyfile. If it
+ * is not set or it's invalid, returns %NM_TERNARY_DEFAULT.
+ */
+NMTernary
+nm_config_get_device_managed(NMConfig *self, const char *ifname)
+{
+    NMConfigPrivate *priv;
+    const GKeyFile  *keyfile = NULL;
+    gs_free char    *group   = NULL;
+
+    g_return_val_if_fail(NM_IS_CONFIG(self), FALSE);
+    g_return_val_if_fail(NM_CONFIG_GET_PRIVATE(self)->config_data, FALSE);
+    g_return_val_if_fail(ifname, FALSE);
+
+    priv    = NM_CONFIG_GET_PRIVATE(self);
+    keyfile = _nm_config_data_get_keyfile_intern(priv->config_data);
+    group   = g_strdup_printf(NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_DEVICE "-%s", ifname);
+
+    if (!keyfile)
+        return NM_TERNARY_DEFAULT;
+
+    return (NMTernary) nm_config_keyfile_get_boolean(keyfile,
+                                                     group,
+                                                     NM_CONFIG_KEYFILE_KEY_DEVICE_MANAGED,
+                                                     NM_TERNARY_DEFAULT);
+}
+
+/**
+ * nm_config_set_device_managed:
+ * @self: the NMConfig instance
+ * @device: the NMDevice instance associated with this config change
+ * @managed: the managed state to set
+ * @by_mac: if %TRUE, match by MAC address, otherwise by interface name. This is
+ *   only used when @managed = TRUE.
+ * @error: return location for a #GError, or %NULL
+ *
+ * Sets the managed state of the device to the intern keyfile. Here we store the
+ * configuration received via the D-Bus API. Configurations from other config
+ * files are still in place and may have higher precedence.
+ *
+ * Prior to setting the new state, the existing configuration is removed. If
+ * @managed is set to %NM_TERNARY_DEFAULT, we only do the removal of the previous
+ * configuration.
+ */
+gboolean
+nm_config_set_device_managed(NMConfig *self,
+                             NMDevice *device,
+                             NMTernary managed,
+                             gboolean  by_mac,
+                             GError  **error)
+{
+    NMConfigPrivate *priv;
+    g_autoptr(GKeyFile) keyfile = NULL;
+    char         *group;
+    gs_free char *group_by_name = NULL;
+    gs_free char *group_by_mac  = NULL;
+    gs_free char *match_value   = NULL;
+    gboolean      changed       = FALSE;
+    const char   *ifname        = nm_device_get_iface(device);
+    const char   *hwaddr        = nm_device_get_permanent_hw_address(device);
+    guint8        hwaddr_bin[NM_UTILS_HWADDR_LEN_MAX];
+    char          hwaddr_chars[NM_UTILS_HWADDR_LEN_MAX * 3 + 1];
+    gsize         hwaddr_bin_len;
+
+    g_return_val_if_fail(NM_IS_CONFIG(self), FALSE);
+    g_return_val_if_fail(NM_CONFIG_GET_PRIVATE(self)->config_data, FALSE);
+    g_return_val_if_fail(ifname && hwaddr, FALSE);
+
+    /* Get a string from the hwaddr that we can use as keyfile's group name.*/
+    if (!_nm_utils_hwaddr_aton(hwaddr, hwaddr_bin, sizeof(hwaddr_bin), &hwaddr_bin_len)) {
+        g_set_error(error,
+                    NM_DEVICE_ERROR,
+                    NM_DEVICE_ERROR_INVALID_ARGUMENT,
+                    "Invalid MAC address: %s",
+                    hwaddr);
+        return FALSE;
+    }
+    nm_utils_bin2hexstr_full(hwaddr_bin, hwaddr_bin_len, '-', TRUE, hwaddr_chars);
+
+    priv          = NM_CONFIG_GET_PRIVATE(self);
+    keyfile       = nm_config_data_clone_keyfile_intern(priv->config_data);
+    group_by_name = g_strdup_printf(NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_DEVICE "-%s", ifname);
+    group_by_mac = g_strdup_printf(NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_DEVICE "-%s", hwaddr_chars);
+
+    /* Remove existing configs. Search them by group name [.intern.device-*]. In
+     * the intern file, 'device' sections are only used for this purpose, so we won't remove
+     * any other device's config. */
+    if (g_key_file_remove_group(keyfile, group_by_name, NULL)
+        || g_key_file_remove_group(keyfile, group_by_mac, NULL))
+        changed = TRUE;
+
+    /* If the new state is not explicitly TRUE of FALSE, we only remove the configs */
+    if (managed == NM_TERNARY_DEFAULT)
+        goto done;
+
+    /* Set new values */
+    if (by_mac) {
+        group       = group_by_mac;
+        match_value = g_strdup_printf("mac:%s", hwaddr);
+    } else {
+        group       = group_by_name;
+        match_value = g_strdup_printf("interface-name:=%s", ifname);
+    }
+
+    g_key_file_set_value(keyfile, group, NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE, match_value);
+    g_key_file_set_value(keyfile, group, NM_CONFIG_KEYFILE_KEY_DEVICE_MANAGED, managed ? "1" : "0");
+    changed = TRUE;
+
+done:
+    if (changed)
+        nm_config_set_values(self, keyfile, TRUE, FALSE);
+
+    return TRUE;
+}
+
+/*****************************************************************************/
+
 /**
  * nm_config_set_values:
  * @self: the NMConfig instance

src/core/nm-config.h

@@ -142,6 +142,13 @@ gboolean nm_config_set_global_dns(NMConfig *self, NMGlobalDnsConfig *global_dns,
 
 void nm_config_set_connectivity_check_enabled(NMConfig *self, gboolean enabled);
 
+NMTernary nm_config_get_device_managed(NMConfig *self, const char *ifname);
+gboolean  nm_config_set_device_managed(NMConfig *self,
+                                       NMDevice *device,
+                                       NMTernary managed,
+                                       gboolean  by_mac,
+                                       GError  **error);
+
 /* internal defines ... */
 extern guint _nm_config_match_nm_version;
 extern char *_nm_config_match_env;

src/libnm-base/nm-config-base.h

@@ -90,4 +90,7 @@
 #define NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN \
     NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN NM_CONFIG_KEYFILE_GROUPPREFIX_GLOBAL_DNS_DOMAIN
 
+#define NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_DEVICE \
+    NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE
+
 #endif /* __NM_CONFIG_BASE_H__ */