diff options
Diffstat (limited to 'udev_sysfs.c')
| -rw-r--r-- | udev_sysfs.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/udev_sysfs.c b/udev_sysfs.c new file mode 100644 index 0000000000..624f53586f --- /dev/null +++ b/udev_sysfs.c @@ -0,0 +1,387 @@ +/* + * udev_sysfs.c - sysfs linux kernel specific knowledge + * + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> + * + * 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 "udev_sysfs.h" +#include "libsysfs/sysfs/libsysfs.h" + +/* list of subsystem specific files + * NULL if there is no file to wait for + */ +static struct subsystem_file { + char *subsystem; + char *file; +} subsystem_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 = "firmware", .file = "data" }, + { .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 } +}; + +int subsystem_expect_no_dev(const char *subsystem) +{ + struct subsystem_file *file; + + for (file = subsystem_files; file->subsystem != NULL; file++) + if (strcmp(subsystem, file->subsystem) == 0) + return 1; + + return 0; +} + +/* get subsystem specific files, returns "dev" if no other found */ +static char *get_subsystem_specific_file(const char *subsystem) +{ + struct subsystem_file *file; + + /* look if we want to look for another file instead of "dev" */ + for (file = subsystem_files; file->subsystem != NULL; file++) + if (strcmp(subsystem, file->subsystem) == 0) + return file->file; + + return "dev"; +} + +/* wait for class pecific file to show up */ +static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev, + const char **error) +{ + const char *file; + char filename[SYSFS_PATH_MAX]; + int loop; + + file = get_subsystem_specific_file(class_dev->classname); + if (file == NULL) { + dbg("class '%s' has no file to wait for", class_dev->classname); + return 0; + } + + strcpy(filename, class_dev->path); + strcat(filename, "/"); + strcat(filename, file); + dbg("looking at class '%s' for specific file '%s' with full name %s", class_dev->classname, file, filename); + + loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; + while (--loop) { + struct stat stats; + + if (stat(class_dev->path, &stats) == -1) { + dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path); + return -ENODEV; + } + + if (stat(filename, &stats) == 0) { + 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); + if (error) + *error = "class specific file unavailable"; + return -ENOENT; +} + +/* 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 = "block", .device = "dm-" }, + { .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 = "lo" }, + { .subsystem = "net", .device = "tap" }, + { .subsystem = "net", .device = "ipsec" }, + { .subsystem = "net", .device = "dummy" }, + { .subsystem = "net", .device = "irda" }, + { .subsystem = "net", .device = "ppp" }, + { .subsystem = "ppp", .device = NULL }, + { .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 */ +int wait_for_bus_device(struct sysfs_device *devices_dev, + const char **error) +{ + 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 devices device */ + loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; + while (--loop) { + if (sysfs_get_device_bus(devices_dev) == 0) + break; + + usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); + } + if (loop == 0) { + dbg("error: getting bus device link"); + if (error) + *error = "no bus device link"; + return -1; + } + dbg("bus device link found for bus '%s'", devices_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(devices_dev->bus, busfile->bus) == 0) { + found = 1; + dbg("looking at bus '%s' for specific file '%s'", devices_dev->bus, busfile->file); + if (sysfs_get_device_attr(devices_dev, busfile->file) != NULL) { + dbg("bus '%s' specific file '%s' found", devices_dev->bus, busfile->file); + return 0; + } + } + } + if (found == 0) { + if (error) + *error = "unknown bus"; + info("error: unknown bus, please report to " + "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus); + return -1; + } + usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); + } + + dbg("error: getting bus '%s' specific file '%s'", devices_dev->bus, busfile->file); + if (error) + *error = "bus specific file unavailable"; + return -1; +} + + +struct sysfs_class_device *open_class_device_wait(const char *path) +{ + struct sysfs_class_device *class_dev; + int loop; + + loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; + while (--loop) { + class_dev = sysfs_open_class_device_path(path); + if (class_dev) + break; + + usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); + } + + return (class_dev); +} + +int wait_for_class_device(struct sysfs_class_device *class_dev, + const char **error) +{ + struct sysfs_class_device *class_dev_parent; + struct sysfs_device *devices_dev = NULL; + int loop; + + if (wait_for_class_device_attributes(class_dev, error) != 0) + return -ENOENT; + + /* skip devices without devices-link */ + if (class_device_expect_no_device_link(class_dev)) { + dbg("no device symlink expected for '%s', ", class_dev->name); + return -ENODEV; + } + + /* 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 devices device */ + dbg("waiting for symlink to devices device"); + loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; + while (--loop) { + if (class_dev_parent) + devices_dev = sysfs_get_classdev_device(class_dev_parent); + else + devices_dev = sysfs_get_classdev_device(class_dev); + + if (devices_dev) + break; + + usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); + } + if (!devices_dev) { + dbg(" error: no devices device symlink found"); + if (error) + *error = "no device symlink"; + return -ENODEV; + } + dbg("device symlink found pointing to '%s'", devices_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); + return 0; + } else { + return wait_for_bus_device(devices_dev, error); + } +} + +struct sysfs_device *open_devices_device_wait(const char *path) +{ + struct sysfs_device *devices_dev; + int loop; + + loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND; + while (--loop) { + devices_dev = sysfs_open_device_path(path); + if (devices_dev) + break; + + usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND); + } + + return(devices_dev); +} |