core: allow disabling auto-scan and notifying ports one by one via API

This commit enables a new core ModemManager daemon option, so that automatic
detection of available modems is totally disabled: '--no-auto-scan'. Note that
this option also replaces the previously used '--test-no-auto-scan' option,
which was only used during tests.

Along with the new ModemManager option, a new ReportKernelEvent() method in
the API is defined, which allows notifying the daemon of which interfaces it
should be accessing, as well as the main details of each interface. The only
mandatory parameters in the new method are 'action' (add/remove), 'name' (the
name of the interface) and 'subsystem' (the subsystem of the interface).

The mmcli tool has support for using the new api method via several new options:

 * The '--report-kernel-event' option allows specifying device ports one by
   one, and is a direct mapping of the ReportKernelEvent() method:
     $ sudo mmcli --report-kernel-event="action=add,name=wwan0,subsystem=net"
     $ sudo mmcli --report-kernel-event="action=add,name=cdc-wdm0,subsystem=usbmisc"

 * The '--report-kernel-event-auto-scan' option uses udev monitoring to notify
   events automatically to the daemon. This allows to operate in a way
   equivalent to the default daemon operation (with implicit auto-scan).

Worth noting that the ReportKernelEvent() method is only usable when
'--no-auto-scan' is explicitly used in the daemon. An error will be reported if
the method is tried while standard udev monitoring is enabled (implicit if
auto scan isn't explicitly disabled in the daemon).

If mmcli is going to be used only to report 'real time' events, an optional
'--initial-kernel-events=[PATH]' may be given in the ModemManager call to
automatically process a set of port kernel events one by one on boot. The file
may e.g. contain:
  action=add,name=wwan0,subsystem=net
  action=add,name=cdc-wdm0,subsystem=usbmisc

1 files changed, 246 insertions, 20 deletions

diff --git a/src/mm-base-manager.c b/src/mm-base-manager.c
index 9da38960..3e03d552 100644
--- a/src/mm-base-manager.c
+++ b/src/mm-base-manager.c
@@ -47,6 +47,7 @@ enum {
     PROP_AUTO_SCAN,
     PROP_ENABLE_TEST,
     PROP_PLUGIN_DIR,
+    PROP_INITIAL_KERNEL_EVENTS,
     LAST_PROP
 };
 
@@ -59,6 +60,8 @@ struct _MMBaseManagerPrivate {
     gboolean enable_test;
     /* Path to look for plugins */
     gchar *plugin_dir;
+    /* Path to the list of initial kernel events */
+    gchar *initial_kernel_events;
     /* The UDev client */
     GUdevClient *udev;
     /* The authorization provider */
@@ -238,6 +241,11 @@ device_added (MMBaseManager  *manager,
 
     g_return_if_fail (port != NULL);
 
+    mm_dbg ("(%s/%s): adding device at sysfs path: %s",
+            mm_kernel_device_get_subsystem (port),
+            mm_kernel_device_get_name (port),
+            mm_kernel_device_get_sysfs_path (port));
+
     if (!mm_kernel_device_is_candidate (port, manual_scan)) {
         /* This could mean that device changed, losing its ID_MM_CANDIDATE
          * flags (such as Bluetooth RFCOMM devices upon disconnect.
@@ -267,6 +275,11 @@ device_added (MMBaseManager  *manager,
     if (!device) {
         FindDeviceSupportContext *ctx;
 
+        mm_dbg ("(%s/%s): first port in device %s",
+                mm_kernel_device_get_subsystem (port),
+                mm_kernel_device_get_name (port),
+                physdev_uid);
+
         /* Keep the device listed in the Manager */
         device = mm_device_new (physdev_uid, hotplugged, FALSE);
         g_hash_table_insert (manager->priv->devices,
@@ -282,12 +295,73 @@ device_added (MMBaseManager  *manager,
             device,
             (GAsyncReadyCallback) device_support_check_ready,
             ctx);
-    }
+    } else
+        mm_dbg ("(%s/%s): additional port in device %s",
+                mm_kernel_device_get_subsystem (port),
+                mm_kernel_device_get_name (port),
+                physdev_uid);
 
     /* Grab the port in the existing device. */
     mm_device_grab_port (device, port);
 }
 
+static gboolean
+handle_kernel_event (MMBaseManager            *self,
+                     MMKernelEventProperties  *properties,
+                     GError                  **error)
+{
+    MMKernelDevice *kernel_device;
+    const gchar    *action;
+    const gchar    *subsystem;
+    const gchar    *name;
+    const gchar    *uid;
+
+    action = mm_kernel_event_properties_get_action (properties);
+    if (!action) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS, "Missing mandatory parameter 'action'");
+        return FALSE;
+    }
+    if (g_strcmp0 (action, "add") != 0 && g_strcmp0 (action, "remove") != 0) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS, "Invalid 'action' parameter given: '%s' (expected 'add' or 'remove')", action);
+        return FALSE;
+    }
+
+    subsystem = mm_kernel_event_properties_get_subsystem (properties);
+    if (!subsystem) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS, "Missing mandatory parameter 'subsystem'");
+        return FALSE;
+    }
+
+    name = mm_kernel_event_properties_get_name (properties);
+    if (!name) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS, "Missing mandatory parameter 'name'");
+        return FALSE;
+    }
+
+    uid = mm_kernel_event_properties_get_uid (properties);
+
+    mm_dbg ("Kernel event reported:");
+    mm_dbg ("  action:    %s", action);
+    mm_dbg ("  subsystem: %s", subsystem);
+    mm_dbg ("  name:      %s", name);
+    mm_dbg ("  uid:       %s", uid ? uid : "n/a");
+
+    kernel_device = mm_kernel_device_udev_new_from_properties (properties, error);
+
+    if (!kernel_device)
+        return FALSE;
+
+    if (g_strcmp0 (action, "add") == 0)
+        device_added (self, kernel_device, TRUE, TRUE);
+    else if (g_strcmp0 (action, "remove") == 0)
+        device_removed (self, kernel_device);
+    else
+        g_assert_not_reached ();
+    g_object_unref (kernel_device);
+
+    return TRUE;
+}
+
 static void
 handle_uevent (GUdevClient *client,
                const char *action,
@@ -356,57 +430,112 @@ start_device_added (MMBaseManager *self,
     g_idle_add ((GSourceFunc)start_device_added_idle, ctx);
 }
 
-void
-mm_base_manager_start (MMBaseManager *manager,
-                       gboolean manual_scan)
+static void
+process_scan (MMBaseManager *self,
+              gboolean       manual_scan)
 {
     GList *devices, *iter;
 
-    g_return_if_fail (manager != NULL);
-    g_return_if_fail (MM_IS_BASE_MANAGER (manager));
-
-    if (!manager->priv->auto_scan && !manual_scan)
-        return;
-
-    mm_dbg ("Starting %s device scan...", manual_scan ? "manual" : "automatic");
-
-    devices = g_udev_client_query_by_subsystem (manager->priv->udev, "tty");
+    devices = g_udev_client_query_by_subsystem (self->priv->udev, "tty");
     for (iter = devices; iter; iter = g_list_next (iter)) {
-        start_device_added (manager, G_UDEV_DEVICE (iter->data), manual_scan);
+        start_device_added (self, G_UDEV_DEVICE (iter->data), manual_scan);
         g_object_unref (G_OBJECT (iter->data));
     }
     g_list_free (devices);
 
-    devices = g_udev_client_query_by_subsystem (manager->priv->udev, "net");
+    devices = g_udev_client_query_by_subsystem (self->priv->udev, "net");
     for (iter = devices; iter; iter = g_list_next (iter)) {
-        start_device_added (manager, G_UDEV_DEVICE (iter->data), manual_scan);
+        start_device_added (self, G_UDEV_DEVICE (iter->data), manual_scan);
         g_object_unref (G_OBJECT (iter->data));
     }
     g_list_free (devices);
 
-    devices = g_udev_client_query_by_subsystem (manager->priv->udev, "usb");
+    devices = g_udev_client_query_by_subsystem (self->priv->udev, "usb");
     for (iter = devices; iter; iter = g_list_next (iter)) {
         const gchar *name;
 
         name = g_udev_device_get_name (G_UDEV_DEVICE (iter->data));
         if (name && g_str_has_prefix (name, "cdc-wdm"))
-            start_device_added (manager, G_UDEV_DEVICE (iter->data), manual_scan);
+            start_device_added (self, G_UDEV_DEVICE (iter->data), manual_scan);
         g_object_unref (G_OBJECT (iter->data));
     }
     g_list_free (devices);
 
     /* Newer kernels report 'usbmisc' subsystem */
-    devices = g_udev_client_query_by_subsystem (manager->priv->udev, "usbmisc");
+    devices = g_udev_client_query_by_subsystem (self->priv->udev, "usbmisc");
     for (iter = devices; iter; iter = g_list_next (iter)) {
         const gchar *name;
 
         name = g_udev_device_get_name (G_UDEV_DEVICE (iter->data));
         if (name && g_str_has_prefix (name, "cdc-wdm"))
-            start_device_added (manager, G_UDEV_DEVICE (iter->data), manual_scan);
+            start_device_added (self, G_UDEV_DEVICE (iter->data), manual_scan);
         g_object_unref (G_OBJECT (iter->data));
     }
     g_list_free (devices);
+}
+
+static void
+process_initial_kernel_events (MMBaseManager *self)
+{
+    gchar *contents = NULL;
+    gchar *line;
+    GError *error = NULL;
+
+    if (!self->priv->initial_kernel_events)
+        return;
+
+    if (!g_file_get_contents (self->priv->initial_kernel_events, &contents, NULL, &error)) {
+        g_warning ("Couldn't load initial kernel events: %s", error->message);
+        g_error_free (error);
+        return;
+    }
+
+    line = contents;
+    while (line) {
+        gchar *next;
+
+        next = strchr (line, '\n');
+        if (next) {
+            *next = '\0';
+            next++;
+        }
+
+        /* ignore empty lines */
+        if (line[0] != '\0') {
+            MMKernelEventProperties *properties;
+
+            properties = mm_kernel_event_properties_new_from_string (line, &error);
+            if (!properties) {
+                g_warning ("Couldn't parse line '%s' as initial kernel event %s", line, error->message);
+                g_clear_error (&error);
+            } else if (!handle_kernel_event (self, properties, &error)) {
+                g_warning ("Couldn't process line '%s' as initial kernel event %s", line, error->message);
+                g_clear_error (&error);
+            } else
+                g_debug ("Processed initial kernel event:' %s'", line);
+        }
+
+        line = next;
+    }
+
+    g_free (contents);
+}
+
+void
+mm_base_manager_start (MMBaseManager *self,
+                       gboolean       manual_scan)
+{
+    g_return_if_fail (self != NULL);
+    g_return_if_fail (MM_IS_BASE_MANAGER (self));
+
+    if (!self->priv->auto_scan && !manual_scan) {
+        /* If we have a list of initial kernel events, process it now */
+        process_initial_kernel_events (self);
+        return;
+    }
 
+    mm_dbg ("Starting %s device scan...", manual_scan ? "manual" : "automatic");
+    process_scan (self, manual_scan);
     mm_dbg ("Finished device scan...");
 }
 
@@ -615,6 +744,81 @@ handle_scan_devices (MmGdbusOrgFreedesktopModemManager1 *manager,
 }
 
 /*****************************************************************************/
+
+typedef struct {
+    MMBaseManager *self;
+    GDBusMethodInvocation *invocation;
+    GVariant *dictionary;
+} ReportKernelEventContext;
+
+static void
+report_kernel_event_context_free (ReportKernelEventContext *ctx)
+{
+    g_object_unref (ctx->invocation);
+    g_object_unref (ctx->self);
+    g_variant_unref (ctx->dictionary);
+    g_slice_free (ReportKernelEventContext, ctx);
+}
+
+static void
+report_kernel_event_auth_ready (MMAuthProvider           *authp,
+                                GAsyncResult             *res,
+                                ReportKernelEventContext *ctx)
+{
+    GError                  *error = NULL;
+    MMKernelEventProperties *properties = NULL;
+
+    if (!mm_auth_provider_authorize_finish (authp, res, &error))
+        goto out;
+
+    if (ctx->self->priv->auto_scan) {
+        error = g_error_new_literal (MM_CORE_ERROR, MM_CORE_ERROR_UNSUPPORTED,
+                                     "Cannot report kernel event: "
+                                     "udev monitoring already in place");
+        goto out;
+    }
+
+    properties = mm_kernel_event_properties_new_from_dictionary (ctx->dictionary, &error);
+    if (!properties)
+        goto out;
+
+    handle_kernel_event (ctx->self, properties, &error);
+
+out:
+    if (error)
+        g_dbus_method_invocation_take_error (ctx->invocation, error);
+    else
+        mm_gdbus_org_freedesktop_modem_manager1_complete_report_kernel_event (
+            MM_GDBUS_ORG_FREEDESKTOP_MODEM_MANAGER1 (ctx->self),
+            ctx->invocation);
+
+    if (properties)
+        g_object_unref (properties);
+    report_kernel_event_context_free (ctx);
+}
+
+static gboolean
+handle_report_kernel_event (MmGdbusOrgFreedesktopModemManager1 *manager,
+                            GDBusMethodInvocation *invocation,
+                            GVariant *dictionary)
+{
+    ReportKernelEventContext *ctx;
+
+    ctx = g_slice_new0 (ReportKernelEventContext);
+    ctx->self = g_object_ref (manager);
+    ctx->invocation = g_object_ref (invocation);
+    ctx->dictionary = g_variant_ref (dictionary);
+
+    mm_auth_provider_authorize (ctx->self->priv->authp,
+                                invocation,
+                                MM_AUTHORIZATION_MANAGER_CONTROL,
+                                ctx->self->priv->authp_cancellable,
+                                (GAsyncReadyCallback)report_kernel_event_auth_ready,
+                                ctx);
+    return TRUE;
+}
+
+/*****************************************************************************/
 /* Test profile setup */
 
 static gboolean
@@ -684,6 +888,7 @@ MMBaseManager *
 mm_base_manager_new (GDBusConnection *connection,
                      const gchar *plugin_dir,
                      gboolean auto_scan,
+                     const gchar *initial_kernel_events,
                      gboolean enable_test,
                      GError **error)
 {
@@ -695,6 +900,7 @@ mm_base_manager_new (GDBusConnection *connection,
                            MM_BASE_MANAGER_CONNECTION, connection,
                            MM_BASE_MANAGER_PLUGIN_DIR, plugin_dir,
                            MM_BASE_MANAGER_AUTO_SCAN, auto_scan,
+                           MM_BASE_MANAGER_INITIAL_KERNEL_EVENTS, initial_kernel_events,
                            MM_BASE_MANAGER_ENABLE_TEST, enable_test,
                            NULL);
 }
@@ -740,6 +946,10 @@ set_property (GObject *object,
         g_free (priv->plugin_dir);
         priv->plugin_dir = g_value_dup_string (value);
         break;
+    case PROP_INITIAL_KERNEL_EVENTS:
+        g_free (priv->initial_kernel_events);
+        priv->initial_kernel_events = g_value_dup_string (value);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -767,6 +977,9 @@ get_property (GObject *object,
     case PROP_PLUGIN_DIR:
         g_value_set_string (value, priv->plugin_dir);
         break;
+    case PROP_INITIAL_KERNEL_EVENTS:
+        g_value_set_string (value, priv->initial_kernel_events);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -812,6 +1025,10 @@ mm_base_manager_init (MMBaseManager *manager)
                       "handle-scan-devices",
                       G_CALLBACK (handle_scan_devices),
                       NULL);
+    g_signal_connect (manager,
+                      "handle-report-kernel-event",
+                      G_CALLBACK (handle_report_kernel_event),
+                      NULL);
 }
 
 static gboolean
@@ -864,6 +1081,7 @@ finalize (GObject *object)
 {
     MMBaseManagerPrivate *priv = MM_BASE_MANAGER (object)->priv;
 
+    g_free (priv->initial_kernel_events);
     g_free (priv->plugin_dir);
 
     g_hash_table_destroy (priv->devices);
@@ -943,4 +1161,12 @@ mm_base_manager_class_init (MMBaseManagerClass *manager_class)
                               "Where to look for plugins",
                               NULL,
                               G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
+
+    g_object_class_install_property
+        (object_class, PROP_INITIAL_KERNEL_EVENTS,
+         g_param_spec_string (MM_BASE_MANAGER_INITIAL_KERNEL_EVENTS,
+                              "Initial kernel events",
+                              "Path to a file with the list of initial kernel events",
+                              NULL,
+                              G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
 }