[PATCH] D-BUS patch for udev-008

[elogind.git] / udev.c

diff --git a/udev.c b/udev.c
index 6e7ac25175b8dc9450b9426cda9a266f538c2288..67b86e5916ced757a921bbbd442bee3e876c6298 100644 (file)
--- a/udev.c
+++ b/udev.c
@@ -27,6 +27,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
+#include <ctype.h>
 
 #include "udev.h"
 #include "udev_version.h"
@@ -34,8 +35,11 @@
 #include "udevdb.h"
 #include "libsysfs/libsysfs.h"
 
+/* global variables */
+char **main_argv;
+char **main_envp;
 
-static char *get_action(void)
+static inline char *get_action(void)
 {
        char *action;
 
@@ -43,22 +47,88 @@ static char *get_action(void)
        return action;
 }
 
+static inline char *get_devpath(void)
+{
+       char *devpath;
+
+       devpath = getenv("DEVPATH");
+       return devpath;
+}
+
+static inline char *get_seqnum(void)
+{
+       char *seqnum;
+
+       seqnum = getenv("SEQNUM");
+       return seqnum;
+}
+
+#ifdef USE_DBUS
+
+/** Global variable for the connection the to system message bus or #NULL
+ *  if we cannot connect or acquire the org.kernel.udev service
+ */
+DBusConnection* sysbus_connection;
 
-static char *get_device(void)
+/** Disconnect from the system message bus */
+static void sysbus_disconnect()
 {
-       char *device;
+        if (sysbus_connection == NULL)
+                return;
 
-       device = getenv("DEVPATH");
-       return device;
+        dbus_connection_disconnect(sysbus_connection);
+        sysbus_connection = NULL;
 }
 
-int main(int argc, char *argv[])
+/** Connect to the system message bus */
+static void sysbus_connect()
+{
+        DBusError error;
+
+        /* Connect to a well-known bus instance, the system bus */
+        dbus_error_init(&error);
+        sysbus_connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
+        if (sysbus_connection == NULL) {
+                dbg("cannot connect to system message bus, error %s: %s", 
+                    error.name, error.message);
+                dbus_error_free(&error);
+                return;
+        }
+
+        /*  Acquire the org.kernel.udev service such that listeners
+         *  know that the message is really from us and not from a
+         *  random attacker. See the file udev_sysbus_policy.conf for
+         *  details.
+         *
+         *  Note that a service can have multiple owners (though there
+         *  is a concept of a primary owner for reception of messages)
+         *  so no race is introduced if two copies of udev is running
+         *  at the same time.
+         */
+        dbus_bus_acquire_service(sysbus_connection, "org.kernel.udev", 0, 
+                                 &error);
+        if (dbus_error_is_set(&error)) {
+                printf("cannot acquire org.kernel.udev service, error %s: %s'",
+                       error.name, error.message);
+                sysbus_disconnect();
+                return;
+        }
+}
+
+#endif /* USE_DBUS */
+
+int main(int argc, char **argv, char **envp)
 {
        char *action;
-       char *device;
+       char *devpath;
        char *subsystem;
        int retval = -EINVAL;
        
+       main_argv = argv;
+       main_envp = envp;
+
+       dbg("version %s", UDEV_VERSION);
+
        if (argc != 2) {
                dbg ("unknown number of arguments");
                goto exit;
@@ -66,17 +136,17 @@ int main(int argc, char *argv[])
 
        subsystem = argv[1];
 
-       device = get_device();
-       if (!device) {
-               dbg ("no device?");
+       devpath = get_devpath();
+       if (!devpath) {
+               dbg ("no devpath?");
                goto exit;
        }
-       dbg("looking at %s", device);
+       dbg("looking at '%s'", devpath);
 
        /* we only care about class devices and block stuff */
-       if (!strstr(device, "class") &&
-           !strstr(device, "block")) {
-               dbg("not block or class");
+       if (!strstr(devpath, "class") &&
+           !strstr(devpath, "block")) {
+               dbg("not a block or class device");
                goto exit;
        }
 
@@ -92,10 +162,18 @@ int main(int argc, char *argv[])
                goto exit;
        }
 
+       /* initialize our configuration */
+       udev_init_config();
+
+#ifdef USE_DBUS
+        /* connect to the system message bus */
+        sysbus_connect();
+#endif /* USE_DBUS */
+
        /* initialize udev database */
        retval = udevdb_init(UDEVDB_DEFAULT);
        if (retval != 0) {
-               dbg("Unable to initialize database.");
+               dbg("unable to initialize database");
                goto exit;
        }
 
@@ -103,18 +181,22 @@ int main(int argc, char *argv[])
        namedev_init();
 
        if (strcmp(action, "add") == 0)
-               retval = udev_add_device(device, argv[1]);
+               retval = udev_add_device(devpath, subsystem);
 
        else if (strcmp(action, "remove") == 0)
-               retval = udev_remove_device(device, argv[1]);
+               retval = udev_remove_device(devpath, subsystem);
 
        else {
-               dbg("Unknown action: %s", action);
+               dbg("unknown action '%s'", action);
                retval = -EINVAL;
        }
        udevdb_exit();
 
+#ifdef USE_DBUS
+        /* disconnect from the system message bus */
+        sysbus_disconnect();
+#endif /* USE_DBUS */
+
 exit:  
        return retval;
 }
-