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, 192 insertions, 29 deletions

diff --git a/src/kerneldevice/mm-kernel-device-udev.c b/src/kerneldevice/mm-kernel-device-udev.c
index 4953f48f..f4b47d88 100644
--- a/src/kerneldevice/mm-kernel-device-udev.c
+++ b/src/kerneldevice/mm-kernel-device-udev.c
@@ -21,11 +21,15 @@
 #include "mm-kernel-device-udev.h"
 #include "mm-log.h"
 
-G_DEFINE_TYPE (MMKernelDeviceUdev, mm_kernel_device_udev,  MM_TYPE_KERNEL_DEVICE)
+static void initable_iface_init (GInitableIface *iface);
+
+G_DEFINE_TYPE_EXTENDED (MMKernelDeviceUdev, mm_kernel_device_udev,  MM_TYPE_KERNEL_DEVICE, 0,
+                        G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE, initable_iface_init))
 
 enum {
     PROP_0,
     PROP_UDEV_DEVICE,
+    PROP_PROPERTIES,
     PROP_LAST
 };
 
@@ -37,6 +41,8 @@ struct _MMKernelDeviceUdevPrivate {
     GUdevDevice *physdev;
     guint16      vendor;
     guint16      product;
+
+    MMKernelEventProperties *properties;
 };
 
 /*****************************************************************************/
@@ -153,8 +159,11 @@ ensure_device_ids (MMKernelDeviceUdev *self)
     if (self->priv->vendor || self->priv->product)
         return;
 
+    if (!self->priv->device)
+        return;
+
     if (!get_device_ids (self->priv->device, &self->priv->vendor, &self->priv->product))
-        mm_dbg ("(%s/%s) could not get vendor/product ID",
+        mm_dbg ("(%s/%s) could not get vendor/product id",
                 g_udev_device_get_subsystem (self->priv->device),
                 g_udev_device_get_name      (self->priv->device));
 }
@@ -240,25 +249,42 @@ ensure_physdev (MMKernelDeviceUdev *self)
 {
     if (self->priv->physdev)
         return;
-    self->priv->physdev = find_physical_gudevdevice (self->priv->device);
+    if (self->priv->device)
+        self->priv->physdev = find_physical_gudevdevice (self->priv->device);
 }
 
 /*****************************************************************************/
 
 static const gchar *
-kernel_device_get_subsystem (MMKernelDevice *self)
+kernel_device_get_subsystem (MMKernelDevice *_self)
 {
-    g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (self), NULL);
+    MMKernelDeviceUdev *self;
+
+    g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), NULL);
+
+    self = MM_KERNEL_DEVICE_UDEV (_self);
+
+    if (self->priv->device)
+        return g_udev_device_get_subsystem (self->priv->device);
 
-    return g_udev_device_get_subsystem (MM_KERNEL_DEVICE_UDEV (self)->priv->device);
+    g_assert (self->priv->properties);
+    return mm_kernel_event_properties_get_subsystem (self->priv->properties);
 }
 
 static const gchar *
-kernel_device_get_name (MMKernelDevice *self)
+kernel_device_get_name (MMKernelDevice *_self)
 {
-    g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (self), NULL);
+    MMKernelDeviceUdev *self;
+
+    g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), NULL);
+
+    self = MM_KERNEL_DEVICE_UDEV (_self);
 
-    return g_udev_device_get_name (MM_KERNEL_DEVICE_UDEV (self)->priv->device);
+    if (self->priv->device)
+        return g_udev_device_get_name (self->priv->device);
+
+    g_assert (self->priv->properties);
+    return mm_kernel_event_properties_get_name (self->priv->properties);
 }
 
 static const gchar *
@@ -271,6 +297,9 @@ kernel_device_get_driver (MMKernelDevice *_self)
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
 
+    if (!self->priv->device)
+        return NULL;
+
     driver = g_udev_device_get_driver (self->priv->device);
     if (!driver) {
         GUdevDevice *parent;
@@ -308,6 +337,9 @@ kernel_device_get_sysfs_path (MMKernelDevice *self)
 {
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE (self), NULL);
 
+    if (!MM_KERNEL_DEVICE_UDEV (self)->priv->device)
+        return NULL;
+
     return g_udev_device_get_sysfs_path (MM_KERNEL_DEVICE_UDEV (self)->priv->device);
 }
 
@@ -320,14 +352,20 @@ kernel_device_get_physdev_uid (MMKernelDevice *_self)
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), NULL);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
-    ensure_physdev (self);
 
-    if (!self->priv->physdev)
-        return NULL;
+    /* Prefer the one coming in the properties, if any */
+    if (self->priv->properties)
+        uid = mm_kernel_event_properties_get_uid (MM_KERNEL_DEVICE_UDEV (self)->priv->properties);
 
-    uid = g_udev_device_get_property (self->priv->physdev, "ID_MM_PHYSDEV_UID");
-    if (!uid)
-        uid = g_udev_device_get_sysfs_path (self->priv->physdev);
+    if (!uid) {
+        ensure_physdev (self);
+        if (!self->priv->physdev)
+            return NULL;
+
+        uid = g_udev_device_get_property (self->priv->physdev, "ID_MM_PHYSDEV_UID");
+        if (!uid)
+            uid = g_udev_device_get_sysfs_path (self->priv->physdev);
+    }
 
     return uid;
 }
@@ -364,7 +402,8 @@ kernel_device_get_parent_sysfs_path (MMKernelDevice *_self)
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), 0);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
-    if (!self->priv->parent)
+
+    if (!self->priv->parent && self->priv->device)
         self->priv->parent = g_udev_device_get_parent (self->priv->device);
     return (self->priv->parent ? g_udev_device_get_sysfs_path (self->priv->parent) : NULL);
 }
@@ -382,6 +421,9 @@ kernel_device_is_candidate (MMKernelDevice *_self,
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
 
+    if (!self->priv->device)
+        return FALSE;
+
     name   = g_udev_device_get_name      (self->priv->device);
     subsys = g_udev_device_get_subsystem (self->priv->device);
 
@@ -455,17 +497,22 @@ kernel_device_cmp (MMKernelDevice *_a,
     a = MM_KERNEL_DEVICE_UDEV (_a);
     b = MM_KERNEL_DEVICE_UDEV (_b);
 
-    if (g_udev_device_has_property (a->priv->device, "DEVPATH_OLD") &&
-        g_str_has_suffix (g_udev_device_get_sysfs_path (b->priv->device),
-                          g_udev_device_get_property   (a->priv->device, "DEVPATH_OLD")))
-        return TRUE;
+    if (a->priv->device && b->priv->device) {
+        if (g_udev_device_has_property (a->priv->device, "DEVPATH_OLD") &&
+            g_str_has_suffix (g_udev_device_get_sysfs_path (b->priv->device),
+                              g_udev_device_get_property   (a->priv->device, "DEVPATH_OLD")))
+            return TRUE;
 
-    if (g_udev_device_has_property (b->priv->device, "DEVPATH_OLD") &&
-        g_str_has_suffix (g_udev_device_get_sysfs_path (a->priv->device),
-                          g_udev_device_get_property   (b->priv->device, "DEVPATH_OLD")))
-        return TRUE;
+        if (g_udev_device_has_property (b->priv->device, "DEVPATH_OLD") &&
+            g_str_has_suffix (g_udev_device_get_sysfs_path (a->priv->device),
+                              g_udev_device_get_property   (b->priv->device, "DEVPATH_OLD")))
+            return TRUE;
+
+        return !g_strcmp0 (g_udev_device_get_sysfs_path (a->priv->device), g_udev_device_get_sysfs_path (b->priv->device));
+    }
 
-    return !g_strcmp0 (g_udev_device_get_sysfs_path (a->priv->device), g_udev_device_get_sysfs_path (b->priv->device));
+    return (!g_strcmp0 (mm_kernel_device_get_subsystem (_a), mm_kernel_device_get_subsystem (_b)) &&
+            !g_strcmp0 (mm_kernel_device_get_name      (_a), mm_kernel_device_get_name      (_b)));
 }
 
 static gboolean
@@ -477,6 +524,10 @@ kernel_device_has_property (MMKernelDevice *_self,
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), FALSE);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
+
+    if (!self->priv->device)
+        return FALSE;
+
     return g_udev_device_has_property (self->priv->device, property);
 }
 
@@ -489,6 +540,10 @@ kernel_device_get_property (MMKernelDevice *_self,
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), NULL);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
+
+    if (!self->priv->device)
+        return NULL;
+
     return g_udev_device_get_property (self->priv->device, property);
 }
 
@@ -501,6 +556,10 @@ kernel_device_get_property_as_boolean (MMKernelDevice *_self,
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), FALSE);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
+
+    if (!self->priv->device)
+        return FALSE;
+
     return g_udev_device_get_property_as_boolean (self->priv->device, property);
 }
 
@@ -513,6 +572,10 @@ kernel_device_get_property_as_int (MMKernelDevice *_self,
     g_return_val_if_fail (MM_IS_KERNEL_DEVICE_UDEV (_self), -1);
 
     self = MM_KERNEL_DEVICE_UDEV (_self);
+
+    if (!self->priv->device)
+        return -1;
+
     return g_udev_device_get_property_as_int (self->priv->device, property);
 }
 
@@ -521,11 +584,31 @@ kernel_device_get_property_as_int (MMKernelDevice *_self,
 MMKernelDevice *
 mm_kernel_device_udev_new (GUdevDevice *udev_device)
 {
+    GError *error = NULL;
+    MMKernelDevice *self;
+
     g_return_val_if_fail (G_UDEV_IS_DEVICE (udev_device), NULL);
 
-    return MM_KERNEL_DEVICE (g_object_new (MM_TYPE_KERNEL_DEVICE_UDEV,
-                                           "udev-device", udev_device,
-                                           NULL));
+    self = MM_KERNEL_DEVICE (g_initable_new (MM_TYPE_KERNEL_DEVICE_UDEV,
+                                             NULL,
+                                             &error,
+                                             "udev-device", udev_device,
+                                             NULL));
+    g_assert_no_error (error);
+    return self;
+}
+
+/*****************************************************************************/
+
+MMKernelDevice *
+mm_kernel_device_udev_new_from_properties (MMKernelEventProperties  *properties,
+                                           GError                  **error)
+{
+    return MM_KERNEL_DEVICE (g_initable_new (MM_TYPE_KERNEL_DEVICE_UDEV,
+                                             NULL,
+                                             error,
+                                             "properties", properties,
+                                             NULL));
 }
 
 /*****************************************************************************/
@@ -550,6 +633,10 @@ set_property (GObject      *object,
         g_assert (!self->priv->device);
         self->priv->device = g_value_dup_object (value);
         break;
+    case PROP_PROPERTIES:
+        g_assert (!self->priv->properties);
+        self->priv->properties = g_value_dup_object (value);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -568,12 +655,73 @@ get_property (GObject    *object,
     case PROP_UDEV_DEVICE:
         g_value_set_object (value, self->priv->device);
         break;
+    case PROP_PROPERTIES:
+        g_value_set_object (value, self->priv->properties);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
     }
 }
 
+static gboolean
+initable_init (GInitable     *initable,
+               GCancellable  *cancellable,
+               GError       **error)
+{
+    MMKernelDeviceUdev *self = MM_KERNEL_DEVICE_UDEV (initable);
+    const gchar *subsystem;
+    const gchar *name;
+
+    /* When created from a GUdevDevice, we're done */
+    if (self->priv->device)
+        return TRUE;
+
+    /* Otherwise, we do need properties with subsystem and name */
+    if (!self->priv->properties) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS,
+                     "missing properties in kernel device");
+        return FALSE;
+    }
+
+    subsystem = mm_kernel_event_properties_get_subsystem (self->priv->properties);
+    if (!subsystem) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS,
+                     "subsystem is mandatory in kernel device");
+        return FALSE;
+    }
+
+    name = mm_kernel_event_properties_get_name (self->priv->properties);
+    if (!mm_kernel_device_get_name (MM_KERNEL_DEVICE (self))) {
+        g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS,
+                     "name is mandatory in kernel device");
+        return FALSE;
+    }
+
+    /* On remove events, we don't look for the GUdevDevice */
+    if (g_strcmp0 (mm_kernel_event_properties_get_action (self->priv->properties), "remove")) {
+        GUdevClient *client;
+        GUdevDevice *device;
+
+        client = g_udev_client_new (NULL);
+        device = g_udev_client_query_by_subsystem_and_name (client, subsystem, name);
+        if (!device) {
+            g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS,
+                         "device %s/%s not found",
+                         subsystem,
+                         name);
+            g_object_unref (client);
+            return FALSE;
+        }
+
+        /* Store device */
+        self->priv->device = device;
+        g_object_unref (client);
+    }
+
+    return TRUE;
+}
+
 static void
 dispose (GObject *object)
 {
@@ -582,11 +730,18 @@ dispose (GObject *object)
     g_clear_object (&self->priv->physdev);
     g_clear_object (&self->priv->parent);
     g_clear_object (&self->priv->device);
+    g_clear_object (&self->priv->properties);
 
     G_OBJECT_CLASS (mm_kernel_device_udev_parent_class)->dispose (object);
 }
 
 static void
+initable_iface_init (GInitableIface *iface)
+{
+    iface->init = initable_init;
+}
+
+static void
 mm_kernel_device_udev_class_init (MMKernelDeviceUdevClass *klass)
 {
     GObjectClass        *object_class        = G_OBJECT_CLASS (klass);
@@ -618,6 +773,14 @@ mm_kernel_device_udev_class_init (MMKernelDeviceUdevClass *klass)
                              "udev device",
                              "Device object as reported by GUdev",
                              G_UDEV_TYPE_DEVICE,
-                             G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);
+                             G_PARAM_READWRITE);
     g_object_class_install_property (object_class, PROP_UDEV_DEVICE, properties[PROP_UDEV_DEVICE]);
+
+    properties[PROP_PROPERTIES] =
+        g_param_spec_object ("properties",
+                             "Properties",
+                             "Generic kernel event properties",
+                             MM_TYPE_KERNEL_EVENT_PROPERTIES,
+                             G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);
+    g_object_class_install_property (object_class, PROP_PROPERTIES, properties[PROP_PROPERTIES]);
 }