summaryrefslogtreecommitdiff
path: root/udev_sysfs.c
diff options
context:
space:
mode:
Diffstat (limited to 'udev_sysfs.c')
-rw-r--r--udev_sysfs.c387
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);
+}