/* * udev.c * * 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 * Free Software Foundation version 2 of the License. * * 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <stdio.h> #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_utils.h" #include "udev_sysfs.h" #include "udev_version.h" #include "udev_rules.h" #include "logging.h" #ifdef USE_LOG 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 /* decide if we should manage the whole hotplug event * for now look if the kernel calls udevsend instead of /sbin/hotplug */ 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, 256); close(fd); if (len < 0) return 0; helper[len] = '\0'; if (strstr(helper, "udevsend")) return 1; return 0; } static void asmlinkage sig_handler(int signum) { switch (signum) { case SIGALRM: exit(1); case SIGINT: case SIGTERM: exit(20 + signum); } } int main(int argc, char *argv[], char *envp[]) { struct sysfs_class_device *class_dev; struct sysfs_device *devices_dev; struct udevice udev; 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; if (argc == 2 && strcmp(argv[1], "-V") == 0) { printf("%s\n", UDEV_VERSION); exit(0); } logging_init("udev"); dbg("version %s", UDEV_VERSION); udev_init_config(); /* 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); /* trigger timeout to prevent hanging processes */ alarm(ALARM_TIMEOUT); /* 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); action = getenv("ACTION"); devpath = getenv("DEVPATH"); subsystem = getenv("SUBSYSTEM"); /* older kernels passed the SUBSYSTEM only as argument */ if (!subsystem && argc == 2) subsystem = argv[1]; udev_init_device(&udev, devpath, subsystem); if (!action || !subsystem || !devpath) { dbg("action, subsystem or devpath missing"); goto hotplug; } /* export logging flag, as called scripts may want to do the same as udev */ if (udev_log) setenv("UDEV_LOG", "1", 1); if (udev.type == DEV_BLOCK || udev.type == DEV_CLASS || udev.type == DEV_NET) { 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); /* init rules */ udev_rules_init(); /* 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; } /* get node from db, remove db-entry, delete created node */ retval = udev_remove_device(&udev); } /* run dev.d/ scripts if we created/deleted a node or changed a netif name */ if (udev.devname[0] != '\0') { setenv("DEVNAME", udev.devname, 1); if (udev_dev_d) udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX); } } 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); wait_for_devices_device(devices_dev, &error); sysfs_close_device(devices_dev); } else if (strcmp(action, "remove") == 0) { dbg("devices remove"); } } else { dbg("unhandled"); } hotplug: udev_cleanup_device(&udev); if (udev_hotplug_d && managed_event) udev_multiplex_directory(&udev, HOTPLUGD_DIR, HOTPLUG_SUFFIX); logging_close(); return retval; }