chiark / gitweb /
udev: clear lists if a new value is assigned
[elogind.git] / udev.c
diff --git a/udev.c b/udev.c
index a41f22277880be604ab4beef193847373110bbd0..999d25d4e5351ad3c1ffc845f4f8a36418680e39 100644 (file)
--- a/udev.c
+++ b/udev.c
@@ -4,6 +4,7 @@
  * Userspace devfs
  *
  * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
  *
  *     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
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
+#include <fcntl.h>
 #include <ctype.h>
 #include <errno.h>
 #include <signal.h>
 #include <unistd.h>
 
 #include "libsysfs/sysfs/libsysfs.h"
+#include "udev_libc_wrapper.h"
 #include "udev.h"
-#include "udev_lib.h"
+#include "udev_utils.h"
 #include "udev_sysfs.h"
 #include "udev_version.h"
-#include "namedev.h"
+#include "udev_rules.h"
 #include "logging.h"
 
-
-#ifdef LOG
-unsigned char logname[LOGNAME_SIZE];
-void log_message(int level, const char *format, ...)
+#ifdef USE_LOG
+void log_message(int priority, const char *format, ...)
 {
        va_list args;
 
-       if (!udev_log)
+       if (priority > udev_log_priority)
                return;
 
        va_start(args, format);
-       vsyslog(level, format, args);
+       vsyslog(priority, format, args);
        va_end(args);
 }
 #endif
 
+/* Decide if we should manage the whole uevent, including multiplexing
+ * of the hotplug directories.
+ * For now look if the kernel calls udevsend instead of /sbin/hotplug,
+ * or the uevent-helper in /proc/sys/kernel/hotplug is empty.
+ */
+static int manage_hotplug_event(void) {
+       char helper[256];
+       int fd;
+       int len;
+
+       /* don't handle hotplug.d if we are called directly */
+       if (!getenv("UDEVD_EVENT"))
+               return 0;
+
+       fd = open("/proc/sys/kernel/hotplug", O_RDONLY);
+       if (fd < 0)
+               return 0;
+
+       len = read(fd, helper, sizeof(helper)-1);
+       close(fd);
+
+       if (len < 0)
+               return 0;
+       helper[len] = '\0';
+
+       if (helper[0] == '\0' || helper[0] == '\n')
+               return 1;
+       if (strstr(helper, "udevsend"))
+               return 1;
+
+       return 0;
+}
+
 static void asmlinkage sig_handler(int signum)
 {
        switch (signum) {
@@ -66,123 +100,155 @@ static void asmlinkage sig_handler(int signum)
 
 int main(int argc, char *argv[], char *envp[])
 {
-       struct sigaction act;
        struct sysfs_class_device *class_dev;
+       struct sysfs_device *devices_dev;
        struct udevice udev;
-       char path[SYSFS_PATH_MAX];
+       char path[PATH_SIZE];
+       const char *error;
+       const char *action;
+       const char *devpath;
+       const char *subsystem;
+       int managed_event;
+       struct sigaction act;
        int retval = -EINVAL;
-       enum {
-               ADD,
-               REMOVE,
-               UDEVSTART,
-       } act_type;
 
-       dbg("version %s", UDEV_VERSION);
+       if (argc == 2 && strcmp(argv[1], "-V") == 0) {
+               printf("%s\n", UDEV_VERSION);
+               exit(0);
+       }
+
        logging_init("udev");
        udev_init_config();
+       dbg("version %s", UDEV_VERSION);
 
-       if (strstr(argv[0], "udevstart") || (argv[1] != NULL && strstr(argv[1], "udevstart"))) {
-               act_type = UDEVSTART;
-       } else {
-               const char *action = getenv("ACTION");
-               const char *devpath = getenv("DEVPATH");
-               const char *subsystem = argv[1];
+       /* set signal handlers */
+       memset(&act, 0x00, sizeof(act));
+       act.sa_handler = (void (*)(int)) sig_handler;
+       sigemptyset (&act.sa_mask);
+       act.sa_flags = 0;
+       sigaction(SIGALRM, &act, NULL);
+       sigaction(SIGINT, &act, NULL);
+       sigaction(SIGTERM, &act, NULL);
 
-               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;
-               }
+       /* trigger timeout to prevent hanging processes */
+       alarm(ALARM_TIMEOUT);
 
-               if (!devpath) {
-                       dbg("no devpath?");
-                       goto exit;
-               }
-               dbg("looking at '%s'", devpath);
+       /* let the executed programs know if we handle the whole hotplug event */
+       managed_event = manage_hotplug_event();
+       if (managed_event)
+               setenv("MANAGED_EVENT", "1", 1);
 
-               /* 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;
-               }
+       action = getenv("ACTION");
+       devpath = getenv("DEVPATH");
+       subsystem = getenv("SUBSYSTEM");
+       /* older kernels passed the SUBSYSTEM only as argument */
+       if (!subsystem && argc == 2)
+               subsystem = argv[1];
 
-               if (!subsystem) {
-                       dbg("no subsystem");
-                       goto exit;
-               }
+       udev_init_device(&udev, devpath, subsystem, action);
 
-               udev_set_values(&udev, devpath, subsystem, action);
+       if (!action || !subsystem || !devpath) {
+               err("action, subsystem or devpath missing");
+               goto hotplug;
+       }
 
-               /* skip blacklisted subsystems */
-               if (udev.type != 'n' && subsystem_expect_no_dev(subsystem)) {
-                       dbg("don't care about '%s' devices", subsystem);
-                       goto exit;
-               };
+       /* export logging flag, as called scripts may want to do the same as udev */
+       if (udev_log_priority) {
+               char priority[32];
 
+               sprintf(priority, "%i", udev_log_priority);
+               setenv("UDEV_LOG", priority, 1);
        }
 
-       /* 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);
+       if (udev.type == DEV_BLOCK || udev.type == DEV_CLASS || udev.type == DEV_NET) {
+               udev_rules_init();
 
-       /* trigger timout to interrupt blocking syscalls */
-       alarm(ALARM_TIMEOUT);
-
-       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;
+               if (strcmp(action, "add") == 0) {
+                       /* wait for sysfs and possibly add node */
+                       dbg("udev add");
+
+                       /* skip subsystems without "dev", but handle net devices */
+                       if (udev.type != DEV_NET && subsystem_expect_no_dev(udev.subsystem)) {
+                               dbg("don't care about '%s' devices", udev.subsystem);
+                               goto hotplug;
+                       }
+
+                       snprintf(path, sizeof(path), "%s%s", sysfs_path, udev.devpath);
+                       path[sizeof(path)-1] = '\0';
+                       class_dev = wait_class_device_open(path);
+                       if (class_dev == NULL) {
+                               dbg("open class device failed");
+                               goto hotplug;
+                       }
+                       dbg("opened class_dev->name='%s'", class_dev->name);
+
+                       wait_for_class_device(class_dev, &error);
+
+                       /* name, create node, store in db */
+                       retval = udev_add_device(&udev, class_dev);
+
+                       sysfs_close_class_device(class_dev);
+               } else if (strcmp(action, "remove") == 0) {
+                       /* possibly remove a node */
+                       dbg("udev remove");
+
+                       /* skip subsystems without "dev" */
+                       if (subsystem_expect_no_dev(udev.subsystem)) {
+                               dbg("don't care about '%s' devices", udev.subsystem);
+                               goto hotplug;
+                       }
+
+                       udev_rules_get_run(&udev);
+                       if (udev.ignore_device) {
+                               dbg("device event will be ignored");
+                               goto hotplug;
+                       }
+
+                       /* get node from db, remove db-entry, delete created node */
+                       retval = udev_remove_device(&udev);
                }
-               dbg("opened class_dev->name='%s'", class_dev->name);
 
-               /* init rules */
-               namedev_init();
+               if (udev.devname[0] != '\0')
+                       setenv("DEVNAME", udev.devname, 1);
 
-               /* name, create node, store in db */
-               retval = udev_add_device(&udev, class_dev);
+               if (udev_run && !list_empty(&udev.run_list)) {
+                       struct name_entry *name_loop;
 
-               /* run dev.d/ scripts if we created a node or changed a netif name */
-               if (udev.devname[0] != '\0') {
-                       setenv("DEVNAME", udev.devname, 1);
-                       dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
+                       dbg("executing run list");
+                       list_for_each_entry(name_loop, &udev.run_list, node)
+                               execute_command(name_loop->name, udev.subsystem);
                }
 
-               sysfs_close_class_device(class_dev);
-               break;
-       case REMOVE:
-               dbg("udev remove");
+       } else if (udev.type == DEV_DEVICE) {
+               if (strcmp(action, "add") == 0) {
+                       /* wait for sysfs */
+                       dbg("devices add");
+
+                       snprintf(path, sizeof(path), "%s%s", sysfs_path, devpath);
+                       path[sizeof(path)-1] = '\0';
+                       devices_dev = wait_devices_device_open(path);
+                       if (!devices_dev) {
+                               dbg("devices device unavailable (probably remove has beaten us)");
+                               goto hotplug;
+                       }
+                       dbg("devices device opened '%s'", path);
 
-               /* get node from db, delete it*/
-               retval = udev_remove_device(&udev);
+                       wait_for_devices_device(devices_dev, &error);
 
-               /* run scripts */
-               dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
+                       sysfs_close_device(devices_dev);
+               } else if (strcmp(action, "remove") == 0) {
+                       dbg("devices remove");
+               }
+       } else {
+               dbg("unhandled");
        }
 
-exit:
+hotplug:
+       if (udev_hotplug_d && managed_event)
+               udev_multiplex_directory(&udev, HOTPLUGD_DIR, HOTPLUG_SUFFIX);
+
+       udev_cleanup_device(&udev);
+
        logging_close();
        return retval;
 }