/*
- * udev_sysfs.c - sysfs linux kernel specific knowledge
+ * udev_sysfs.c - sysfs access
*
- * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
- * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2005 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 <stdlib.h>
#include <stdio.h>
#include <stddef.h>
-#include <stdlib.h>
#include <unistd.h>
-#include <string.h>
+#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <sys/stat.h>
-#include "libsysfs/sysfs/libsysfs.h"
-#include "udev_version.h"
-#include "udev_sysfs.h"
-#include "udev_lib.h"
-#include "logging.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 }
-};
+#include "udev.h"
-int subsystem_expect_no_dev(const char *subsystem)
-{
- struct subsystem_file *file;
+char sysfs_path[PATH_SIZE];
- for (file = subsystem_files; file->subsystem != NULL; file++)
- if (strcmp(subsystem, file->subsystem) == 0)
- return 1;
+/* device cache */
+static LIST_HEAD(dev_list);
- return 0;
-}
+/* attribute value cache */
+static LIST_HEAD(attr_list);
+struct sysfs_attr {
+ struct list_head node;
+ char path[PATH_SIZE];
+ char *value; /* points to value_local if value is cached */
+ char value_local[NAME_SIZE];
+};
-/* get subsystem specific files, returns "dev" if no other found */
-static char *get_subsystem_specific_file(const char *subsystem)
+int sysfs_init(void)
{
- 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";
+ const char *env;
+
+ env = getenv("SYSFS_PATH");
+ if (env) {
+ strlcpy(sysfs_path, env, sizeof(sysfs_path));
+ remove_trailing_chars(sysfs_path, '/');
+ } else
+ strlcpy(sysfs_path, "/sys", sizeof(sysfs_path));
+ dbg("sysfs_path='%s'", sysfs_path);
+
+ INIT_LIST_HEAD(&dev_list);
+ INIT_LIST_HEAD(&attr_list);
+ return 0;
}
-/* wait for class pecific file to show up */
-static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
- const char **error)
+void sysfs_cleanup(void)
{
- 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;
+ struct sysfs_attr *attr_loop;
+ struct sysfs_attr *attr_temp;
+ struct sysfs_device *dev_loop;
+ struct sysfs_device *dev_temp;
+
+ list_for_each_entry_safe(attr_loop, attr_temp, &attr_list, node) {
+ list_del(&attr_loop->node);
+ free(attr_loop);
}
- snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", class_dev->path, file);
- dbg("looking at class '%s' for specific file '%s'", class_dev->classname, 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);
+ list_for_each_entry_safe(dev_loop, dev_temp, &dev_list, node) {
+ list_del(&dev_loop->node);
+ free(dev_loop);
}
-
- 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)
+void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath, const char *subsystem)
{
- /* 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 = "block", .device = "bcrypt" },
- { .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 = "net", .device = "tun" },
- { .subsystem = "net", .device = "pan" },
- { .subsystem = "net", .device = "bnep" },
- { .subsystem = "net", .device = "vmnet" },
- { .subsystem = "net", .device = "ippp" },
- { .subsystem = "ppp", .device = NULL },
- { .subsystem = "sound", .device = NULL },
- { .subsystem = "printer", .device = "lp" },
- { .subsystem = "nvidia", .device = NULL },
- { .subsystem = "video4linux", .device = "vbi" },
- { .subsystem = "dvb", .device = NULL },
- { .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 },
- { .subsystem = "zaptel", .device = NULL },
- { .subsystem = "tiglusb", .device = NULL },
- { .subsystem = "ppdev", .device = NULL },
- { .subsystem = "ticables", .device = NULL },
- { .subsystem = "snsc", .device = NULL },
- { .subsystem = "staliomem", .device = NULL },
- { .subsystem = "tape", .device = NULL },
- { .subsystem = "ip2", .device = NULL },
- { .subsystem = "tpqic02", .device = NULL },
- { .subsystem = "dsp56k", .device = NULL },
- { .subsystem = "zft", .device = NULL },
- { .subsystem = "adb", .device = NULL },
- { .subsystem = "cosa", .device = NULL },
- { .subsystem = "pg", .device = NULL },
- { .subsystem = "pt", .device = NULL },
- { .subsystem = "capi", .device = NULL },
- { NULL, NULL }
- };
- struct class_device *classdevice;
- int len;
-
- /* the kernel may tell us what to wait for */
- if (kernel_release_satisfactory(2,6,10) > 0)
- if (getenv("PHYSDEVPATH") == NULL) {
- dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
- return 1;
- }
-
- 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;
- }
+ char *pos;
+
+ strlcpy(dev->devpath, devpath, sizeof(dev->devpath));
+ if (subsystem != NULL)
+ strlcpy(dev->subsystem, subsystem, sizeof(dev->subsystem));
+
+ /* set kernel name */
+ pos = strrchr(dev->devpath, '/');
+ if (pos == NULL)
+ return;
+
+ strlcpy(dev->kernel_name, &pos[1], sizeof(dev->kernel_name));
+ dbg("kernel_name='%s'", dev->kernel_name);
+
+ /* some devices have '!' in their name, change that to '/' */
+ pos = dev->kernel_name;
+ while (pos[0] != '\0') {
+ if (pos[0] == '!')
+ pos[0] = '/';
+ pos++;
}
- return 0;
+ /* get kernel number */
+ pos = &dev->kernel_name[strlen(dev->kernel_name)];
+ while (isdigit(pos[-1]))
+ pos--;
+ strlcpy(dev->kernel_number, pos, sizeof(dev->kernel_number));
+ dbg("kernel_number='%s'", dev->kernel_number);
}
-/* skip waiting for the bus of the devices device */
-static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
+struct sysfs_device *sysfs_device_get(const char *devpath)
{
- static char *devices_without_bus[] = {
- "scsi_host",
- "i2c-adapter",
- "i2c-dev",
- 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;
- }
+ char path[PATH_SIZE];
+ char devpath_real[PATH_SIZE];
+ struct sysfs_device *dev;
+ struct sysfs_device *dev_loop;
+ struct stat statbuf;
+ char link_path[PATH_SIZE];
+ char link_target[PATH_SIZE];
+ int len;
+ char *pos;
- return 0;
-}
+ dbg("open '%s'", devpath);
+ strlcpy(devpath_real, devpath, sizeof(devpath_real));
+ remove_trailing_chars(devpath_real, '/');
-/* wait for a devices device specific file to show up */
-int wait_for_devices_device(struct sysfs_device *devices_dev,
- const char **error)
-{
- static struct device_file {
- char *bus;
- char *file;
- } device_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" },
- { .bus = "ieee1394", .file = "node_count" },
- { .bus = "ieee1394", .file = "nodeid" },
- { .bus = "ieee1394", .file = "address" },
- { NULL, NULL }
- };
- struct device_file *devicefile;
- int loop;
-
- /* the kernel may tell us what to wait for */
- if (kernel_release_satisfactory(2,6,10) > 0)
- if (getenv("PHYSDEVBUS") == NULL) {
- dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
- return 0;
+ /* look for device already in cache (we never put an untranslated path in the cache) */
+ list_for_each_entry(dev_loop, &dev_list, node) {
+ if (strcmp(dev_loop->devpath, devpath_real) == 0) {
+ dbg("found in cache '%s'", dev_loop->devpath);
+ return dev_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 we got a link, resolve it to the real device */
+ strlcpy(path, sysfs_path, sizeof(path));
+ strlcat(path, devpath_real, sizeof(path));
+ if (lstat(path, &statbuf) != 0) {
+ dbg("stat '%s' failed: %s", path, strerror(errno));
+ return NULL;
}
- if (loop == 0) {
- dbg("error: getting bus device link");
- if (error)
- *error = "no bus device link";
- return -1;
+ if (S_ISLNK(statbuf.st_mode)) {
+ int i;
+ int back;
+
+ len = readlink(path, link_target, sizeof(link_target));
+ if (len <= 0)
+ return NULL;
+ link_target[len] = '\0';
+ dbg("devpath link '%s' points to '%s'", path, link_target);
+
+ for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
+ ;
+ dbg("base '%s', tail '%s', back %i", devpath_real, &link_target[back * 3], back);
+ for (i = 0; i <= back; i++) {
+ pos = strrchr(devpath_real, '/');
+ if (pos == NULL)
+ return NULL;
+ pos[0] = '\0';
+ }
+ dbg("after moving back '%s'", devpath_real);
+ strlcat(devpath_real, "/", sizeof(devpath_real));
+ strlcat(devpath_real, &link_target[back * 3], sizeof(devpath_real));
+
+ /* now look for device in cache after path translation */
+ list_for_each_entry(dev_loop, &dev_list, node) {
+ if (strcmp(dev_loop->devpath, devpath_real) == 0) {
+ dbg("found in cache '%s'", dev_loop->devpath);
+ return dev_loop;
+ }
+ }
}
- dbg("bus device link found for bus '%s'", devices_dev->bus);
-
- /* wait for a bus device specific file to show up */
- loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
- while (--loop) {
- int found_bus_type = 0;
-
- for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
- if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
- char filename[SYSFS_PATH_MAX];
- struct stat stats;
-
- found_bus_type = 1;
- snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, devicefile->file);
- dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);
-
- if (stat(filename, &stats) == 0) {
- dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
- return 0;
- }
+
+ /* it is a new device */
+ dbg("'%s'", devpath_real);
+ dev = malloc(sizeof(struct sysfs_device));
+ if (dev == NULL)
+ return NULL;
+ memset(dev, 0x00, sizeof(struct sysfs_device));
+
+ sysfs_device_set_values(dev, devpath_real, NULL);
+
+ /* get subsystem */
+ if (strncmp(dev->devpath, "/class/", 7) == 0) {
+ strlcpy(dev->subsystem, &dev->devpath[7], sizeof(dev->subsystem));
+ pos = strchr(dev->subsystem, '/');
+ if (pos != NULL)
+ pos[0] = '\0';
+ else
+ dev->subsystem[0] = '\0';
+ } else if (strncmp(dev->devpath, "/block/", 7) == 0) {
+ strlcpy(dev->subsystem, "block", sizeof(dev->subsystem));
+ } else if (strncmp(dev->devpath, "/devices/", 9) == 0) {
+ /* get subsystem from "bus" link */
+ strlcpy(link_path, sysfs_path, sizeof(link_path));
+ strlcat(link_path, dev->devpath, sizeof(link_path));
+ strlcat(link_path, "/bus", sizeof(link_path));
+ len = readlink(link_path, link_target, sizeof(link_target));
+ if (len > 0) {
+ link_target[len] = '\0';
+ dbg("bus link '%s' points to '%s'", link_path, link_target);
+ pos = strrchr(link_target, '/');
+ if (pos != NULL)
+ strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
+ } else {
+ /* get subsystem from "subsystem" link */
+ strlcpy(link_path, sysfs_path, sizeof(link_path));
+ strlcat(link_path, dev->devpath, sizeof(link_path));
+ strlcat(link_path, "/subsystem", sizeof(link_path));
+ len = readlink(link_path, link_target, sizeof(link_target));
+ if (len > 0) {
+ link_target[len] = '\0';
+ dbg("subsystem link '%s' points to '%s'", link_path, link_target);
+ pos = strrchr(link_target, '/');
+ if (pos != NULL)
+ strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
}
}
- if (found_bus_type == 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;
+ /* get driver name */
+ strlcpy(link_path, sysfs_path, sizeof(link_path));
+ strlcat(link_path, dev->devpath, sizeof(link_path));
+ strlcat(link_path, "/driver", sizeof(link_path));
+ len = readlink(link_path, link_target, sizeof(link_target));
+ if (len > 0) {
+ link_target[len] = '\0';
+ dbg("driver link '%s' points to '%s'", link_path, link_target);
+ pos = strrchr(link_target, '/');
+ if (pos != NULL)
+ strlcpy(dev->driver, &pos[1], sizeof(dev->driver));
}
- usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
+ } else if (strncmp(dev->devpath, "/bus/", 5) == 0 && strstr(dev->devpath, "/drivers/")) {
+ strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem));
+ } else if (strncmp(dev->devpath, "/module/", 8) == 0) {
+ strlcpy(dev->subsystem, "module", sizeof(dev->subsystem));
}
- dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
- if (error)
- *error = "bus device specific file unavailable";
- return -1;
-}
-
-
-struct sysfs_class_device *wait_class_device_open(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;
+ dbg("add to cache 'devpath=%s', subsystem='%s', driver='%s'", dev->devpath, dev->subsystem, dev->driver);
+ list_add(&dev->node, &dev_list);
- usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
- }
-
- return (class_dev);
+ return dev;
}
-int wait_for_class_device(struct sysfs_class_device *class_dev,
- const char **error)
+struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
{
- 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 0;
+ char parent_devpath[PATH_SIZE];
+ char device_link[PATH_SIZE];
+ char device_link_target[PATH_SIZE];
+ char *pos;
+ int i;
+ int len;
+ int back;
+
+ if (dev->parent != NULL)
+ return dev->parent;
+
+ /* requesting a parent is only valid for devices */
+ if ((strncmp(dev->devpath, "/devices/", 9) != 0) &&
+ (strncmp(dev->devpath, "/class/", 7) != 0) &&
+ (strncmp(dev->devpath, "/block/", 7) != 0))
+ return NULL;
+
+ strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath));
+ dbg("'%s'", parent_devpath);
+
+ /* strip last element */
+ pos = strrchr(parent_devpath, '/');
+ if (pos == NULL || pos == parent_devpath)
+ return NULL;
+ pos[0] = '\0';
+
+ /* are we at the top level */
+ if (strcmp(parent_devpath, "/devices") == 0) {
+ dbg("/devices top level");
+ return NULL;
}
- /* 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);
+ /* at the top level of class/block we want to follow the "device" link */
+ if (strcmp(parent_devpath, "/block") == 0) {
+ dbg("/block top level, look for device link");
+ goto device_link;
}
- if (!devices_dev) {
- dbg(" error: no devices device symlink found");
- if (error)
- *error = "no device symlink";
- return -ENODEV;
+ if (strncmp(parent_devpath, "/class", 6) == 0) {
+ pos = strrchr(parent_devpath, '/');
+ if (pos == &parent_devpath[6] || pos == parent_devpath) {
+ dbg("/class top level, look for device link");
+ goto device_link;
+ }
}
- dbg("device symlink found pointing to '%s'", devices_dev->path);
-
- /* wait for the devices device */
- if (class_device_expect_no_bus(class_dev)) {
- dbg("no bus device expected for '%s', ", class_dev->classname);
- return 0;
+ dev->parent = sysfs_device_get(parent_devpath);
+ return dev->parent;
+
+device_link:
+ strlcpy(device_link, sysfs_path, sizeof(device_link));
+ strlcat(device_link, dev->devpath, sizeof(device_link));
+ strlcat(device_link, "/device", sizeof(device_link));
+ len = readlink(device_link, device_link_target, sizeof(device_link_target));
+ if (len < 0)
+ return NULL;
+ device_link_target[len] = '\0';
+ dbg("device link '%s' points to '%s'", device_link, device_link_target);
+
+ for (back = 0; strncmp(&device_link_target[back * 3], "../", 3) == 0; back++)
+ ;
+ strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath));
+ dbg("base='%s', tail='%s', back=%i", parent_devpath, &device_link_target[back * 3], back);
+ for (i = 0; i < back; i++) {
+ pos = strrchr(parent_devpath, '/');
+ if (pos == NULL)
+ return NULL;
+ pos[0] = '\0';
}
+ dbg("after moving back '%s'", parent_devpath);
+ strlcat(parent_devpath, "/", sizeof(parent_devpath));
+ strlcat(parent_devpath, &device_link_target[back * 3], sizeof(parent_devpath));
- return wait_for_devices_device(devices_dev, error);
+ dev->parent = sysfs_device_get(parent_devpath);
+ return dev->parent;
}
-struct sysfs_device *wait_devices_device_open(const char *path)
+struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device *dev, const char *subsystem)
{
- struct sysfs_device *devices_dev;
- int loop;
+ struct sysfs_device *dev_parent;
- loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
- while (--loop) {
- devices_dev = sysfs_open_device_path(path);
- if (devices_dev)
- break;
+ dev_parent = sysfs_device_get_parent(dev);
+ while (dev_parent != NULL) {
+ if (strcmp(dev_parent->subsystem, subsystem) == 0)
+ return dev_parent;
+ dev_parent = sysfs_device_get_parent(dev_parent);
+ }
+ return NULL;
+}
- usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
+char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
+{
+ char path_full[PATH_SIZE];
+ const char *path;
+ char value[NAME_SIZE];
+ struct sysfs_attr *attr_loop;
+ struct sysfs_attr *attr;
+ int fd;
+ ssize_t size;
+ size_t sysfs_len;
+
+ sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
+ path = &path_full[sysfs_len];
+ strlcat(path_full, devpath, sizeof(path_full));
+ strlcat(path_full, "/", sizeof(path_full));
+ strlcat(path_full, attr_name, sizeof(path_full));
+
+ /* look for attribute in cache */
+ list_for_each_entry(attr_loop, &attr_list, node) {
+ if (strcmp(attr_loop->path, path) == 0) {
+ dbg("found in cache '%s'", attr_loop->path);
+ return attr_loop->value;
+ }
}
- return(devices_dev);
+ /* store attribute in cache (also negatives are kept in cache) */
+ attr = malloc(sizeof(struct sysfs_attr));
+ if (attr == NULL)
+ return NULL;
+ memset(attr, 0x00, sizeof(struct sysfs_attr));
+ strlcpy(attr->path, path, sizeof(attr->path));
+ dbg("add to cache '%s' '%s'", attr->path, attr->value);
+ list_add(&attr->node, &attr_list);
+
+ /* read attribute value */
+ fd = open(path_full, O_RDONLY);
+ if (fd < 0)
+ goto out;
+ size = read(fd, value, sizeof(value));
+ close(fd);
+ if (size < 0)
+ goto out;
+ if (size == sizeof(value))
+ goto out;
+
+ /* got a valid value, store and return it */
+ value[size] = '\0';
+ remove_trailing_chars(value, '\n');
+ strlcpy(attr->value_local, value, sizeof(attr->value_local));
+ attr->value = attr->value_local;
+
+out:
+ return attr->value;
}
~ianmdlvl / elogind.git / blobdiff