chiark / gitweb /
[PATCH] Don't use any syslog() in signal handler, cause it may deadlock.
[elogind.git] / udev.c
diff --git a/udev.c b/udev.c
index 38b26916c99a63eb1774b5bb41e8c3361363e683..78090605206f1fab763c4a1dccb21d485967940b 100644 (file)
--- a/udev.c
+++ b/udev.c
  *
  */
 
+#include <stdio.h>
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
-#include <errno.h>
 #include <ctype.h>
+#include <errno.h>
 #include <signal.h>
+#include <unistd.h>
 
+#include "libsysfs/sysfs/libsysfs.h"
 #include "udev.h"
+#include "udev_lib.h"
+#include "udev_sysfs.h"
 #include "udev_version.h"
-#include "udev_dbus.h"
 #include "logging.h"
 #include "namedev.h"
 #include "udevdb.h"
-#include "libsysfs/libsysfs.h"
+
+/* timeout flag for udevdb */
+extern sig_atomic_t gotalarm;
 
 /* global variables */
 char **main_argv;
 char **main_envp;
 
-static void sig_handler(int signum)
+#ifdef LOG
+unsigned char logname[LOGNAME_SIZE];
+void log_message(int level, const char *format, ...)
+{
+       va_list args;
+
+       if (!udev_log)
+               return;
+
+       va_start(args, format);
+       vsyslog(level, format, args);
+       va_end(args);
+}
+#endif
+
+static void asmlinkage sig_handler(int signum)
 {
-       dbg("caught signal %d", signum);
        switch (signum) {
+               case SIGALRM:
+                       gotalarm = 1;
+                       break;
                case SIGINT:
                case SIGTERM:
-                       sysbus_disconnect();
-                       udevdb_exit();
                        exit(20 + signum);
-                       break;
-               default:
-                       dbg("unhandled signal");
        }
 }
 
-static inline char *get_action(void)
+int main(int argc, char *argv[], char *envp[])
 {
-       char *action;
+       struct sigaction act;
+       struct sysfs_class_device *class_dev;
+       struct udevice udev;
+       char path[SYSFS_PATH_MAX];
+       int retval = -EINVAL;
+       enum {
+               ADD,
+               REMOVE,
+               UDEVSTART,
+       } act_type;
 
-       action = getenv("ACTION");
-       return action;
-}
+       dbg("version %s", UDEV_VERSION);
 
-static inline char *get_devpath(void)
-{
-       char *devpath;
+       main_argv = argv;
+       main_envp = envp;
 
-       devpath = getenv("DEVPATH");
-       return devpath;
-}
+       logging_init("udev");
 
-static inline char *get_seqnum(void)
-{
-       char *seqnum;
+       udev_init_config();
 
-       seqnum = getenv("SEQNUM");
-       return seqnum;
-}
+       if (strstr(argv[0], "udevstart")) {
+               act_type = UDEVSTART;
+       } else {
+               const char *action = get_action();
+               const char *devpath = get_devpath();
+               const char *subsystem = get_subsystem(main_argv[1]);
 
-static char *subsystem_blacklist[] = {
-       "net",
-       "scsi_host",
-       "scsi_device",
-       "usb_host",
-       "pci_bus",
-       "",
-};
+               if (!action) {
+                       dbg("no action?");
+                       goto exit;
+               }
+               if (strcmp(action, "add") == 0) {
+                       act_type = ADD;
+               } else if (strcmp(action, "remove") == 0) {
+                       act_type = REMOVE;
+               } else {
+                       dbg("no action '%s' for us", action);
+                       goto exit;
+               }
 
-static int udev_hotplug(int argc, char **argv)
-{
-       char *action;
-       char *devpath;
-       char *subsystem;
-       int retval = -EINVAL;
-       int i;
+               if (!devpath) {
+                       dbg("no devpath?");
+                       goto exit;
+               }
+               dbg("looking at '%s'", devpath);
 
-       action = get_action();
-       if (!action) {
-               dbg ("no action?");
-               goto exit;
-       }
+               /* we only care about class devices and block stuff */
+               if (!strstr(devpath, "class") && !strstr(devpath, "block")) {
+                       dbg("not a block or class device");
+                       goto exit;
+               }
 
-       devpath = get_devpath();
-       if (!devpath) {
-               dbg ("no devpath?");
-               goto exit;
-       }
-       dbg("looking at '%s'", devpath);
+               if (!subsystem) {
+                       dbg("no subsystem");
+                       goto exit;
+               }
 
-       /* we only care about class devices and block stuff */
-       if (!strstr(devpath, "class") &&
-           !strstr(devpath, "block")) {
-               dbg("not a block or class device");
-               goto exit;
-       }
+               udev_set_values(&udev, devpath, subsystem);
 
-       /* skip blacklisted subsystems */
-       subsystem = argv[1];
-       i = 0;
-       while (subsystem_blacklist[i][0] != '\0') {
-               if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
+               /* skip blacklisted subsystems */
+               if (udev.type != 'n' && subsystem_expect_no_dev(subsystem)) {
                        dbg("don't care about '%s' devices", subsystem);
                        goto exit;
-               }
-               i++;
+               };
+
        }
 
-       /* connect to the system message bus */
-       sysbus_connect();
+       /* set signal handlers */
+       act.sa_handler = (void (*) (int))sig_handler;
+       sigemptyset (&act.sa_mask);
+       act.sa_flags = 0;
+       /* alarm must not restart syscalls*/
+       sigaction(SIGALRM, &act, NULL);
+       sigaction(SIGINT, &act, NULL);
+       sigaction(SIGTERM, &act, NULL);
 
-       /* initialize our configuration */
-       udev_init_config();
+       /* trigger timout to interrupt blocking syscalls */
+       alarm(ALARM_TIMEOUT);
 
        /* initialize udev database */
-       retval = udevdb_init(UDEVDB_DEFAULT);
-       if (retval != 0) {
-               dbg("unable to initialize database");
-               goto exit_sysbus;
-       }
+       if (udevdb_init(UDEVDB_DEFAULT) != 0)
+               info("error: unable to initialize database, continuing without database");
+
+       switch(act_type) {
+       case UDEVSTART:
+               dbg("udevstart");
+               namedev_init();
+               retval = udev_start();
+               break;
+       case ADD:
+               dbg("udev add");
+
+               /* open the device */
+               snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, udev.devpath);
+               class_dev = sysfs_open_class_device_path(path);
+               if (class_dev == NULL) {
+                       dbg ("sysfs_open_class_device_path failed");
+                       break;
+               }
+               dbg("opened class_dev->name='%s'", class_dev->name);
 
-       /* set up a default signal handler for now */
-       signal(SIGINT, sig_handler);
-       signal(SIGTERM, sig_handler);
+               /* init rules */
+               namedev_init();
 
-       /* initialize the naming deamon */
-       namedev_init();
+               /* name, create node, store in db */
+               retval = udev_add_device(&udev, class_dev);
 
-       if (strcmp(action, "add") == 0)
-               retval = udev_add_device(devpath, subsystem);
+               /* run scripts */
+               dev_d_execute(&udev);
 
-       else if (strcmp(action, "remove") == 0)
-               retval = udev_remove_device(devpath, subsystem);
+               sysfs_close_class_device(class_dev);
+               break;
+       case REMOVE:
+               dbg("udev remove");
 
-       else {
-               dbg("unknown action '%s'", action);
-               retval = -EINVAL;
+               /* get node from db, delete it*/
+               retval = udev_remove_device(&udev);
+
+               /* run scripts */
+               dev_d_execute(&udev);
        }
-       udevdb_exit();
 
-exit_sysbus:
-       /* disconnect from the system message bus */
-       sysbus_disconnect();
+       udevdb_exit();
 
 exit:
-       if (retval > 0)
-               retval = 0;
-
-       return -retval;
-}
-
-int main(int argc, char **argv, char **envp)
-{
-       main_argv = argv;
-       main_envp = envp;
-
-       dbg("version %s", UDEV_VERSION);
-
-       return udev_hotplug(argc, argv);
+       logging_close();
+       return retval;
 }
-
-