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

2 files changed, 148 insertions, 2 deletions

diff --git a/cli/Makefile.am b/cli/Makefile.am
index d2573dbc..7915f289 100644
--- a/cli/Makefile.am
+++ b/cli/Makefile.am
@@ -2,6 +2,7 @@ bin_PROGRAMS = mmcli
 
 mmcli_CPPFLAGS = \
 	$(MMCLI_CFLAGS) \
+        $(GUDEV_CFLAGS) \
 	-I$(top_srcdir) \
 	-I$(top_srcdir)/include \
 	-I$(top_builddir)/include \
@@ -34,6 +35,7 @@ mmcli_SOURCES = \
 	$(NULL)
 
 mmcli_LDADD = \
+        $(GUDEV_LIBS) \
 	$(MMCLI_LIBS) \
 	$(top_builddir)/libmm-glib/libmm-glib.la \
 	$(NULL)
diff --git a/cli/mmcli-manager.c b/cli/mmcli-manager.c
index 9960412e..4e078f17 100644
--- a/cli/mmcli-manager.c
+++ b/cli/mmcli-manager.c
@@ -15,8 +15,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
- * Copyright (C) 2011 Aleksander Morgado <aleksander@gnu.org>
  * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2011-2016 Aleksander Morgado <aleksander@aleksander.es>
  */
 
 #include "config.h"
@@ -29,6 +29,8 @@
 #include <glib.h>
 #include <gio/gio.h>
 
+#include <gudev/gudev.h>
+
 #define _LIBMM_INSIDE_MMCLI
 #include "libmm-glib.h"
 
@@ -39,6 +41,7 @@
 typedef struct {
     MMManager *manager;
     GCancellable *cancellable;
+    GUdevClient *udev;
 } Context;
 static Context *ctx;
 
@@ -47,6 +50,8 @@ static gboolean list_modems_flag;
 static gboolean monitor_modems_flag;
 static gboolean scan_modems_flag;
 static gchar *set_logging_str;
+static gchar *report_kernel_event_str;
+static gboolean report_kernel_event_auto_scan;
 
 static GOptionEntry entries[] = {
     { "set-logging", 'G', 0, G_OPTION_ARG_STRING, &set_logging_str,
@@ -65,6 +70,14 @@ static GOptionEntry entries[] = {
       "Request to re-scan looking for modems",
       NULL
     },
+    { "report-kernel-event", 'K', 0, G_OPTION_ARG_STRING, &report_kernel_event_str,
+      "Report kernel event",
+      "[\"key=value,...\"]"
+    },
+    { "report-kernel-event-auto-scan", 0, 0, G_OPTION_ARG_NONE, &report_kernel_event_auto_scan,
+      "Automatically report kernel events based on udev notifications",
+      NULL
+    },
     { NULL }
 };
 
@@ -96,7 +109,9 @@ mmcli_manager_options_enabled (void)
     n_actions = (list_modems_flag +
                  monitor_modems_flag +
                  scan_modems_flag +
-                 !!set_logging_str);
+                 !!set_logging_str +
+                 !!report_kernel_event_str +
+                 report_kernel_event_auto_scan);
 
     if (n_actions > 1) {
         g_printerr ("error: too many manager actions requested\n");
@@ -106,6 +121,9 @@ mmcli_manager_options_enabled (void)
     if (monitor_modems_flag)
         mmcli_force_async_operation ();
 
+    if (report_kernel_event_auto_scan)
+        mmcli_force_async_operation ();
+
     checked = TRUE;
     return !!n_actions;
 }
@@ -116,6 +134,8 @@ context_free (Context *ctx)
     if (!ctx)
         return;
 
+    if (ctx->udev)
+        g_object_unref (ctx->udev);
     if (ctx->manager)
         g_object_unref (ctx->manager);
     if (ctx->cancellable)
@@ -130,6 +150,47 @@ mmcli_manager_shutdown (void)
 }
 
 static void
+report_kernel_event_process_reply (gboolean      result,
+                                   const GError *error)
+{
+    if (!result) {
+        g_printerr ("error: couldn't report kernel event: '%s'\n",
+                    error ? error->message : "unknown error");
+        exit (EXIT_FAILURE);
+    }
+
+    g_print ("successfully reported kernel event\n");
+}
+
+static void
+report_kernel_event_ready (MMManager    *manager,
+                           GAsyncResult *result)
+{
+    gboolean operation_result;
+    GError *error = NULL;
+
+    operation_result = mm_manager_report_kernel_event_finish (manager, result, &error);
+    report_kernel_event_process_reply (operation_result, error);
+
+    mmcli_async_operation_done ();
+}
+
+static MMKernelEventProperties *
+build_kernel_event_properties_from_input (const gchar *properties_string)
+{
+    GError *error = NULL;
+    MMKernelEventProperties *properties;
+
+    properties = mm_kernel_event_properties_new_from_string (properties_string, &error);
+    if (!properties) {
+        g_printerr ("error: cannot parse properties string: '%s'\n", error->message);
+        exit (EXIT_FAILURE);
+    }
+
+    return properties;
+}
+
+static void
 set_logging_process_reply (gboolean      result,
                            const GError *error)
 {
@@ -248,6 +309,22 @@ cancelled (GCancellable *cancellable)
 }
 
 static void
+handle_uevent (GUdevClient *client,
+               const char  *action,
+               GUdevDevice *device,
+               gpointer     none)
+{
+    MMKernelEventProperties *properties;
+
+    properties = mm_kernel_event_properties_new ();
+    mm_kernel_event_properties_set_action (properties, action);
+    mm_kernel_event_properties_set_subsystem (properties, g_udev_device_get_subsystem (device));
+    mm_kernel_event_properties_set_name (properties, g_udev_device_get_name (device));
+    mm_manager_report_kernel_event (ctx->manager, properties, NULL, NULL, NULL);
+    g_object_unref (properties);
+}
+
+static void
 get_manager_ready (GObject      *source,
                    GAsyncResult *result,
                    gpointer      none)
@@ -276,6 +353,54 @@ get_manager_ready (GObject      *source,
         return;
     }
 
+    /* Request to report kernel event? */
+    if (report_kernel_event_str) {
+        MMKernelEventProperties *properties;
+
+        properties = build_kernel_event_properties_from_input (report_kernel_event_str);
+        mm_manager_report_kernel_event (ctx->manager,
+                                        properties,
+                                        ctx->cancellable,
+                                        (GAsyncReadyCallback)report_kernel_event_ready,
+                                        NULL);
+        g_object_unref (properties);
+        return;
+    }
+
+    if (report_kernel_event_auto_scan) {
+        const gchar *subsys[] = { "tty", "usbmisc", "net", NULL };
+        guint i;
+
+        ctx->udev = g_udev_client_new (subsys);
+        g_signal_connect (ctx->udev, "uevent", G_CALLBACK (handle_uevent), NULL);
+
+        for (i = 0; subsys[i]; i++) {
+            GList *list, *iter;
+
+            list = g_udev_client_query_by_subsystem (ctx->udev, subsys[i]);
+            for (iter = list; iter; iter = g_list_next (iter)) {
+                MMKernelEventProperties *properties;
+                GUdevDevice *device;
+
+                device = G_UDEV_DEVICE (iter->data);
+                properties = mm_kernel_event_properties_new ();
+                mm_kernel_event_properties_set_action (properties, "add");
+                mm_kernel_event_properties_set_subsystem (properties, subsys[i]);
+                mm_kernel_event_properties_set_name (properties, g_udev_device_get_name (device));
+                mm_manager_report_kernel_event (ctx->manager, properties, NULL, NULL, NULL);
+                g_object_unref (properties);
+            }
+            g_list_free_full (list, (GDestroyNotify) g_object_unref);
+        }
+
+        /* If we get cancelled, operation done */
+        g_cancellable_connect (ctx->cancellable,
+                               G_CALLBACK (cancelled),
+                               NULL,
+                               NULL);
+        return;
+    }
+
     /* Request to monitor modems? */
     if (monitor_modems_flag) {
         g_signal_connect (ctx->manager,
@@ -332,6 +457,11 @@ mmcli_manager_run_synchronous (GDBusConnection *connection)
         exit (EXIT_FAILURE);
     }
 
+    if (report_kernel_event_auto_scan) {
+        g_printerr ("error: monitoring udev events cannot be done synchronously\n");
+        exit (EXIT_FAILURE);
+    }
+
     /* Initialize context */
     ctx = g_new0 (Context, 1);
     ctx->manager = mmcli_get_manager_sync (connection);
@@ -362,6 +492,20 @@ mmcli_manager_run_synchronous (GDBusConnection *connection)
         return;
     }
 
+    /* Request to report kernel event? */
+    if (report_kernel_event_str) {
+        MMKernelEventProperties *properties;
+        gboolean result;
+
+        properties = build_kernel_event_properties_from_input (report_kernel_event_str);
+        result = mm_manager_report_kernel_event_sync (ctx->manager,
+                                                      properties,
+                                                      NULL,
+                                                      &error);
+        report_kernel_event_process_reply (result, error);
+        return;
+    }
+
     /* Request to list modems? */
     if (list_modems_flag) {
         list_current_modems (ctx->manager);