/* * wait_for_sysfs.c - small program to delay the execution * of /etc/hotplug.d/ programs, until sysfs * is fully populated by the kernel. Depending on * the type of device, we wait for all expected * directories and then just exit. * * 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 <unistd.h> #include <string.h> #include <ctype.h> #include <errno.h> #include <sys/stat.h> #include "logging.h" #include "udev_version.h" #include "libsysfs/sysfs/libsysfs.h" #ifdef LOG unsigned char logname[LOGNAME_SIZE]; void log_message(int level, const char *format, ...) { va_list args; va_start(args, format); vsyslog(level, format, args); va_end(args); } #endif #define WAIT_MAX_SECONDS 10 #define WAIT_LOOP_PER_SECOND 20 /* wait for specific file to show up, normally the "dev"-file */ static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev) { static struct class_file { char *subsystem; char *file; } class_files[] = { { .subsystem = "net", .file = "ifindex" }, { .subsystem = "scsi_host", .file = "unique_id" }, { .subsystem = "scsi_device", .file = NULL }, { .subsystem = "pcmcia_socket", .file = "card_type" }, { .subsystem = "usb_host", .file = NULL }, { .subsystem = "bluetooth", .file = "address" }, { .subsystem = "i2c-adapter", .file = NULL }, { .subsystem = "pci_bus", .file = NULL }, { .subsystem = "ieee1394", .file = NULL }, { .subsystem = "ieee1394_host", .file = NULL }, { .subsystem = "ieee1394_node", .file = NULL }, { NULL, NULL } }; struct class_file *classfile; const char *file = "dev"; int loop; /* look if we want to look for another file instead of "dev" */ for (classfile = class_files; classfile->subsystem != NULL; classfile++) { if (strcmp(class_dev->classname, classfile->subsystem) == 0) { if (classfile->file == NULL) { dbg("class '%s' has no file to wait for", class_dev->classname); return 0; } file = classfile->file; break; } } dbg("looking at class '%s' for specific file '%s'", class_dev->classname, file); loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { if (sysfs_get_classdev_attr(class_dev, file) != NULL) { dbg("class '%s' specific file '%s' found", class_dev->classname, file); return 0; } usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file); return -1; } /* check if we need to wait for a physical device */ static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev) { /* list of devices without a "device" symlink to the physical device * if device is set to NULL, no devices in that subsystem has a link */ static struct class_device { char *subsystem; char *device; } class_device[] = { { .subsystem = "block", .device = "double" }, { .subsystem = "block", .device = "nb" }, { .subsystem = "block", .device = "ram" }, { .subsystem = "block", .device = "loop" }, { .subsystem = "block", .device = "fd" }, { .subsystem = "block", .device = "md" }, { .subsystem = "block", .device = "dos_cd" }, { .subsystem = "block", .device = "rflash" }, { .subsystem = "block", .device = "rom" }, { .subsystem = "block", .device = "rrom" }, { .subsystem = "block", .device = "flash" }, { .subsystem = "block", .device = "msd" }, { .subsystem = "block", .device = "sbpcd" }, { .subsystem = "block", .device = "pcd" }, { .subsystem = "block", .device = "pf" }, { .subsystem = "block", .device = "scd" }, { .subsystem = "block", .device = "ubd" }, { .subsystem = "input", .device = "event" }, { .subsystem = "input", .device = "mice" }, { .subsystem = "input", .device = "mouse" }, { .subsystem = "input", .device = "ts" }, { .subsystem = "vc", .device = NULL }, { .subsystem = "tty", .device = NULL }, { .subsystem = "cpuid", .device = "cpu" }, { .subsystem = "graphics", .device = "fb" }, { .subsystem = "mem", .device = NULL }, { .subsystem = "misc", .device = NULL }, { .subsystem = "msr", .device = NULL }, { .subsystem = "netlink", .device = NULL }, { .subsystem = "net", .device = "sit" }, { .subsystem = "net", .device = "ppp" }, { .subsystem = "net", .device = "lo" }, { .subsystem = "net", .device = "tap" }, { .subsystem = "net", .device = "ipsec" }, { .subsystem = "sound", .device = NULL }, { .subsystem = "printer", .device = "lp" }, { .subsystem = "nvidia", .device = NULL }, { .subsystem = "video4linux", .device = "vbi" }, { .subsystem = "lirc", .device = NULL }, { .subsystem = "firmware", .device = NULL }, { .subsystem = "drm", .device = NULL }, { .subsystem = "pci_bus", .device = NULL }, { .subsystem = "ieee1394", .device = NULL }, { .subsystem = "ieee1394_host", .device = NULL }, { .subsystem = "ieee1394_node", .device = NULL }, { .subsystem = "raw", .device = NULL }, { NULL, NULL } }; struct class_device *classdevice; int len; for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) { if (strcmp(class_dev->classname, classdevice->subsystem) == 0) { /* see if no device in this class is expected to have a device-link */ if (classdevice->device == NULL) return 1; len = strlen(classdevice->device); /* see if device name matches */ if (strncmp(class_dev->name, classdevice->device, len) != 0) continue; /* exact name match */ if (strlen(class_dev->name) == len) return 1; /* name match with instance number */ if (isdigit(class_dev->name[len])) return 1; } } return 0; } /* skip waiting for the bus */ static int class_device_expect_no_bus(struct sysfs_class_device *class_dev) { static char *devices_without_bus[] = { "scsi_host", "i2c-adapter", NULL }; char **device; for (device = devices_without_bus; *device != NULL; device++) { int len = strlen(*device); if (strncmp(class_dev->classname, *device, len) == 0) return 1; } return 0; } /* wait for the bus and for a bus specific file to show up */ static int wait_for_bus_device(struct sysfs_device *device_dev) { static struct bus_file { char *bus; char *file; } bus_files[] = { { .bus = "scsi", .file = "vendor" }, { .bus = "usb", .file = "idVendor" }, { .bus = "usb", .file = "iInterface" }, { .bus = "usb", .file = "bNumEndpoints" }, { .bus = "usb-serial", .file = "detach_state" }, { .bus = "ide", .file = "detach_state" }, { .bus = "pci", .file = "vendor" }, { .bus = "platform", .file = "detach_state" }, { .bus = "i2c", .file = "detach_state" }, { NULL } }; struct bus_file *busfile; int loop; /* wait for the /bus-device link to the /device-device */ loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { if (sysfs_get_device_bus(device_dev) == 0) break; usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } if (loop == 0) { dbg("error: getting /bus-device link"); return -1; } dbg("/bus-device link found for bus '%s'", device_dev->bus); /* wait for a bus specific file to show up */ loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { int found = 0; for (busfile = bus_files; busfile->bus != NULL; busfile++) { if (strcmp(device_dev->bus, busfile->bus) == 0) { found = 1; dbg("looking at bus '%s' for specific file '%s'", device_dev->bus, busfile->file); if (sysfs_get_device_attr(device_dev, busfile->file) != NULL) { dbg("bus '%s' specific file '%s' found", device_dev->bus, busfile->file); return 0; } } } if (found == 0) { info("error: unknown bus, please report to " "<linux-hotplug-devel@lists.sourceforge.net> '%s'", device_dev->bus); return -1; } usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } dbg("error: getting bus '%s' specific file '%s'", device_dev->bus, busfile->file); return -1; } int main(int argc, char *argv[], char *envp[]) { const char *devpath = ""; const char *action; const char *subsystem; char sysfs_path[SYSFS_PATH_MAX]; char filename[SYSFS_PATH_MAX]; struct sysfs_class_device *class_dev; struct sysfs_class_device *class_dev_parent; struct sysfs_device *device_dev = NULL; int loop; int rc = 0; init_logging("wait_for_sysfs"); if (argc != 2) { dbg("error: subsystem"); return 1; } subsystem = argv[1]; devpath = getenv ("DEVPATH"); if (!devpath) { dbg("error: no DEVPATH"); return 1; } action = getenv ("ACTION"); if (!action) { dbg("error: no ACTION"); return 1; } /* we only wait on an add event */ if (strcmp(action, "add") != 0) return 0; if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) { dbg("error: no sysfs path"); return 2; } if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) { /* open the class device we are called for */ snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath); filename[SYSFS_PATH_MAX-1] = '\0'; loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { class_dev = sysfs_open_class_device_path(filename); if (class_dev) break; usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } if (class_dev == NULL) { dbg("error: getting class_device"); rc = 3; goto exit; } dbg("class_device opened '%s'", filename); if (wait_for_class_device_attributes(class_dev) != 0) { rc = 4; goto exit_class; } /* skip devices without /device-link */ if (class_device_expect_no_device_link(class_dev)) { dbg("no device symlink expected for '%s', ", class_dev->name); goto exit_class; } /* the symlink may be on the parent device */ class_dev_parent = sysfs_get_classdev_parent(class_dev); if (class_dev_parent) dbg("looking at parent device for device link '%s'", class_dev_parent->path); /* wait for the symlink to the /device-device */ dbg("waiting for symlink to /device-device"); loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { if (class_dev_parent) device_dev = sysfs_get_classdev_device(class_dev_parent); else device_dev = sysfs_get_classdev_device(class_dev); if (device_dev) break; usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } if (device_dev == NULL) { dbg("error: getting /device-device"); rc = 5; goto exit_class; } dbg("device symlink found pointing to '%s'", device_dev->path); /* wait for the bus value */ if (class_device_expect_no_bus(class_dev)) { dbg("no bus device expected for '%s', ", class_dev->classname); } else { if (wait_for_bus_device(device_dev) != 0) rc = 6; } exit_class: sysfs_close_class_device(class_dev); } else if ((strncmp(devpath, "/devices/", 9) == 0)) { /* open the path we are called for */ snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath); filename[SYSFS_PATH_MAX-1] = '\0'; loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; while (--loop) { device_dev = sysfs_open_device_path(filename); if (device_dev) break; usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); } if (device_dev == NULL) { dbg("error: getting /device-device"); rc = 7; goto exit; } dbg("device_device opened '%s'", filename); /* wait for the bus value */ if (wait_for_bus_device(device_dev) != 0) rc = 8; sysfs_close_device(device_dev); } else { dbg("unhandled sysfs path, no need to wait"); } exit: if (rc == 0) dbg("result: waiting for sysfs successful '%s'", devpath); else info("either wait_for_sysfs (udev %s) needs an update to handle the device '%s' " "properly (%d) or the sysfs-support of your device's driver needs to be fixed, " "please report to <linux-hotplug-devel@lists.sourceforge.net>", UDEV_VERSION, devpath, rc); return rc; }