dispatcher-connection: new dispatcher for connection status scripts

The user or the packages can install custom dispatcher scripts that
will be run by the ModemManaer daemon itself upon bearer connection
status updates.

Scripts installed by users should go into the
/etc/ModemManager/connection.d directory.

Scripts installed by packages should go into the
/usr/lib/ModemManager/connection.d directory.

The name of the script will specify the order how it's run, so it's
suggested to name them with a numeric prefix, e.g. "99-something".

1 files changed, 231 insertions, 0 deletions

diff --git a/src/mm-dispatcher-connection.c b/src/mm-dispatcher-connection.c
new file mode 100644
index 000000000..7f370a595
--- /dev/null
+++ b/src/mm-dispatcher-connection.c
@@ -0,0 +1,231 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2022 Aleksander Morgado <aleksander@aleksander.es>
+ */
+
+#include <config.h>
+#include <sys/stat.h>
+
+#include <ModemManager.h>
+#include "mm-errors-types.h"
+#include "mm-utils.h"
+#include "mm-log-object.h"
+#include "mm-dispatcher-connection.h"
+
+#if !defined CONNECTIONDIRPACKAGE
+# error CONNECTIONDIRPACKAGE must be defined at build time
+#endif
+
+#if !defined CONNECTIONDIRUSER
+# error CONNECTIONDIRUSER must be defined at build time
+#endif
+
+#define OPERATION_DESCRIPTION "connection status report"
+#define CONNECTED_STRING      "connected"
+#define DISCONNECTED_STRING   "disconnected"
+
+/* Maximum time a connection dispatcher command is allowed to run before
+ * us killing it */
+#define MAX_CONNECTION_EXEC_TIME_SECS 5
+
+struct _MMDispatcherConnection {
+    MMDispatcher parent;
+};
+
+struct _MMDispatcherConnectionClass {
+    MMDispatcherClass parent;
+};
+
+G_DEFINE_TYPE (MMDispatcherConnection, mm_dispatcher_connection, MM_TYPE_DISPATCHER)
+
+/*****************************************************************************/
+
+typedef struct {
+    gchar    *modem_dbus_path;
+    gchar    *bearer_dbus_path;
+    gchar    *data_port;
+    gboolean  connected;
+    GList    *dispatcher_scripts;
+    GFile    *current;
+    guint     n_failures;
+} ConnectionRunContext;
+
+static void
+connection_run_context_free (ConnectionRunContext *ctx)
+{
+    g_assert (!ctx->current);
+    g_free (ctx->modem_dbus_path);
+    g_free (ctx->bearer_dbus_path);
+    g_free (ctx->data_port);
+    g_list_free_full (ctx->dispatcher_scripts, (GDestroyNotify)g_object_unref);
+    g_slice_free (ConnectionRunContext, ctx);
+}
+
+gboolean
+mm_dispatcher_connection_run_finish (MMDispatcherConnection  *self,
+                                     GAsyncResult           *res,
+                                     GError                **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void connection_run_next (GTask *task);
+
+static void
+dispatcher_run_ready (MMDispatcher *self,
+                      GAsyncResult *res,
+                      GTask        *task)
+{
+    ConnectionRunContext *ctx;
+    g_autoptr(GError)     error = NULL;
+
+    ctx = g_task_get_task_data (task);
+
+    if (!mm_dispatcher_run_finish (self, res, &error)) {
+        ctx->n_failures++;
+        mm_obj_warn (self, "Cannot run " OPERATION_DESCRIPTION " operation from %s: %s",
+                     g_file_peek_path (ctx->current), error->message);
+    } else
+        mm_obj_dbg (self, OPERATION_DESCRIPTION " operation successfully from %s",
+                    g_file_peek_path (ctx->current));
+
+    g_clear_object (&ctx->current);
+    connection_run_next (task);
+}
+
+static void
+connection_run_next (GTask *task)
+{
+    MMDispatcherConnection *self;
+    ConnectionRunContext   *ctx;
+    g_autofree gchar       *path = NULL;
+    GPtrArray              *aux;
+    g_auto(GStrv)           argv = NULL;
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    if (!ctx->dispatcher_scripts) {
+        if (ctx->n_failures)
+            g_task_return_new_error (task, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+                                     "Failed %u " OPERATION_DESCRIPTION " operations",
+                                     ctx->n_failures);
+        else
+            g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+    }
+
+    /* store current file reference in context */
+    ctx->current = ctx->dispatcher_scripts->data;
+    ctx->dispatcher_scripts = g_list_delete_link (ctx->dispatcher_scripts, ctx->dispatcher_scripts);
+    path = g_file_get_path (ctx->current);
+
+    /* build argv */
+    aux = g_ptr_array_new ();
+    g_ptr_array_add (aux, g_steal_pointer (&path));
+    g_ptr_array_add (aux, g_strdup (ctx->modem_dbus_path));
+    g_ptr_array_add (aux, g_strdup (ctx->bearer_dbus_path));
+    g_ptr_array_add (aux, g_strdup (ctx->data_port));
+    g_ptr_array_add (aux, g_strdup (ctx->connected ? CONNECTED_STRING : DISCONNECTED_STRING));
+    g_ptr_array_add (aux, NULL);
+    argv = (GStrv) g_ptr_array_free (aux, FALSE);
+
+    /* run */
+    mm_dispatcher_run (MM_DISPATCHER (self),
+                       argv,
+                       MAX_CONNECTION_EXEC_TIME_SECS,
+                       g_task_get_cancellable (task),
+                       (GAsyncReadyCallback) dispatcher_run_ready,
+                       task);
+}
+
+static gint
+dispatcher_script_cmp (GFile *a,
+                       GFile *b)
+{
+    g_autofree gchar *a_name = NULL;
+    g_autofree gchar *b_name = NULL;
+
+    a_name = g_file_get_basename (a);
+    b_name = g_file_get_basename (b);
+
+    return g_strcmp0 (a_name, b_name);
+}
+
+void
+mm_dispatcher_connection_run (MMDispatcherConnection *self,
+                              const gchar            *modem_dbus_path,
+                              const gchar            *bearer_dbus_path,
+                              const gchar            *data_port,
+                              gboolean                connected,
+                              GCancellable           *cancellable,
+                              GAsyncReadyCallback     callback,
+                              gpointer                user_data)
+{
+    GTask                *task;
+    ConnectionRunContext *ctx;
+    guint                 i;
+    const gchar          *enabled_dirs[] = {
+        CONNECTIONDIRUSER,    /* sysconfdir */
+        CONNECTIONDIRPACKAGE, /* libdir */
+    };
+
+    task = g_task_new (self, cancellable, callback, user_data);
+
+    ctx = g_slice_new0 (ConnectionRunContext);
+    ctx->modem_dbus_path = g_strdup (modem_dbus_path);
+    ctx->bearer_dbus_path = g_strdup (bearer_dbus_path);
+    ctx->data_port = g_strdup (data_port);
+    ctx->connected = connected;
+    g_task_set_task_data (task, ctx, (GDestroyNotify)connection_run_context_free);
+
+    /* Iterate over all enabled dirs and collect all dispatcher script paths */
+    for (i = 0; i < G_N_ELEMENTS (enabled_dirs); i++) {
+        g_autoptr(GFile)            dir_file = NULL;
+        g_autoptr(GFileEnumerator)  enumerator = NULL;
+        GFile                      *child;
+
+        dir_file = g_file_new_for_path (enabled_dirs[i]);
+        enumerator = g_file_enumerate_children (dir_file,
+                                                G_FILE_ATTRIBUTE_STANDARD_NAME,
+                                                G_FILE_QUERY_INFO_NONE,
+                                                cancellable,
+                                                NULL);
+        if (!enumerator)
+            continue;
+
+        while (g_file_enumerator_iterate (enumerator, NULL, &child, cancellable, NULL) && child)
+            ctx->dispatcher_scripts = g_list_prepend (ctx->dispatcher_scripts, g_object_ref (child));
+    }
+
+    /* Sort all by filename, regardless of the directory where they're in */
+    ctx->dispatcher_scripts = g_list_sort (ctx->dispatcher_scripts, (GCompareFunc)dispatcher_script_cmp);
+
+    connection_run_next (task);
+}
+
+/*****************************************************************************/
+
+static void
+mm_dispatcher_connection_init (MMDispatcherConnection *self)
+{
+}
+
+static void
+mm_dispatcher_connection_class_init (MMDispatcherConnectionClass *class)
+{
+}
+
+MM_DEFINE_SINGLETON_GETTER (MMDispatcherConnection, mm_dispatcher_connection_get, MM_TYPE_DISPATCHER_CONNECTION,
+                            MM_DISPATCHER_OPERATION_DESCRIPTION, OPERATION_DESCRIPTION)