X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev.c;h=67b86e5916ced757a921bbbd442bee3e876c6298;hb=5aebfbcb62614fc2bf2b1579d62e3fe272c6751a;hp=6e7ac25175b8dc9450b9426cda9a266f538c2288;hpb=dbfc520c605dee3244dbbfd563e908901324689b;p=elogind.git

diff --git a/udev.c b/udev.c
index 6e7ac2517..67b86e591 100644
--- 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;
 }
-