/*
- * udev_sysfs.c - sysfs access
- *
- * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2005-2006 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
*
* 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.
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
+#include <sys/stat.h>
#include "udev.h"
struct sysfs_attr {
struct list_head node;
char path[PATH_SIZE];
- char value[NAME_SIZE];
+ char *value; /* points to value_local if value is cached */
+ char value_local[NAME_SIZE];
};
int sysfs_init(void)
}
}
-void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath, const char *subsystem)
+void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath,
+ const char *subsystem, const char *driver)
{
char *pos;
strlcpy(dev->devpath, devpath, sizeof(dev->devpath));
if (subsystem != NULL)
strlcpy(dev->subsystem, subsystem, sizeof(dev->subsystem));
+ if (driver != NULL)
+ strlcpy(dev->driver, driver, sizeof(dev->driver));
/* 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);
+ strlcpy(dev->kernel, &pos[1], sizeof(dev->kernel));
+ dbg("kernel='%s'", dev->kernel);
/* some devices have '!' in their name, change that to '/' */
- pos = dev->kernel_name;
+ pos = dev->kernel;
while (pos[0] != '\0') {
if (pos[0] == '!')
pos[0] = '/';
}
/* get kernel number */
- pos = &dev->kernel_name[strlen(dev->kernel_name)];
+ pos = &dev->kernel[strlen(dev->kernel)];
while (isdigit(pos[-1]))
pos--;
strlcpy(dev->kernel_number, pos, sizeof(dev->kernel_number));
strlcpy(devpath_real, devpath, sizeof(devpath_real));
remove_trailing_chars(devpath_real, '/');
+ /* 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;
+ }
+ }
+
+ /* 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 we got a link, resolve it to the real device */
if (S_ISLNK(statbuf.st_mode)) {
int i;
int back;
dbg("after moving back '%s'", devpath_real);
strlcat(devpath_real, "/", sizeof(devpath_real));
strlcat(devpath_real, &link_target[back * 3], sizeof(devpath_real));
- }
- /* look for device in 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;
+ /* 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;
+ }
}
}
- /* new device */
- dbg("'%s'", devpath_real);
+ /* it is a new device */
+ dbg("new uncached device '%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);
+ sysfs_device_set_values(dev, devpath_real, NULL, NULL);
/* get subsystem */
if (strncmp(dev->devpath, "/class/", 7) == 0) {
int len;
int back;
+ dbg("open '%s'", dev->devpath);
+
+ /* look if we already know the parent */
+ 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) &&
return NULL;
pos[0] = '\0';
- /* are we at the top level */
+ /* are we at the top level of /devices */
if (strcmp(parent_devpath, "/devices") == 0) {
dbg("/devices top level");
return NULL;
}
- /* at the top level we may follow the "device" link */
+ /* 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 (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");
+ dbg("/class top level, look for device link");
goto device_link;
}
}
- return sysfs_device_get(parent_devpath);
+ /* get parent and remember it */
+ dev->parent = sysfs_device_get(parent_devpath);
+ return dev->parent;
device_link:
strlcpy(device_link, sysfs_path, sizeof(device_link));
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 sysfs_device_get(parent_devpath);
+
+ /* get parent and remember it */
+ dev->parent = sysfs_device_get(parent_devpath);
+ return dev->parent;
+}
+
+struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device *dev, const char *subsystem)
+{
+ struct sysfs_device *dev_parent;
+
+ 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;
}
char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
char value[NAME_SIZE];
struct sysfs_attr *attr_loop;
struct sysfs_attr *attr;
+ struct stat statbuf;
int fd;
ssize_t size;
size_t sysfs_len;
+ dbg("open '%s'/'%s'", devpath, attr_name);
sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
path = &path_full[sysfs_len];
strlcat(path_full, devpath, sizeof(path_full));
}
}
+ /* store attribute in cache (also negatives are kept in cache) */
+ dbg("new uncached attribute '%s'", path_full);
+ 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'", path_full);
+ list_add(&attr->node, &attr_list);
+
+ if (lstat(path_full, &statbuf) != 0) {
+ dbg("stat '%s' failed: %s", path_full, strerror(errno));
+ goto out;
+ }
+
+ if (S_ISLNK(statbuf.st_mode)) {
+ /* links return the last element of the target path */
+ char link_target[PATH_SIZE];
+ int len;
+ const char *pos;
+
+ len = readlink(path_full, link_target, sizeof(link_target));
+ if (len > 0) {
+ link_target[len] = '\0';
+ pos = strrchr(link_target, '/');
+ if (pos != NULL) {
+ dbg("cache '%s' with link value '%s'", path_full, value);
+ strlcpy(attr->value_local, &pos[1], sizeof(attr->value_local));
+ attr->value = attr->value_local;
+ }
+ }
+ goto out;
+ }
+
+ /* skip directories */
+ if (S_ISDIR(statbuf.st_mode))
+ goto out;
+
+ /* skip non-readable files */
+ if ((statbuf.st_mode & S_IRUSR) == 0)
+ goto out;
+
/* read attribute value */
fd = open(path_full, O_RDONLY);
- if (fd < 0)
- return NULL;
+ if (fd < 0) {
+ dbg("attribute '%s' does not exist", path_full);
+ goto out;
+ }
size = read(fd, value, sizeof(value));
close(fd);
if (size < 0)
- return NULL;
+ goto out;
if (size == sizeof(value))
- return NULL;
+ goto out;
+
+ /* got a valid value, store and return it */
value[size] = '\0';
remove_trailing_chars(value, '\n');
+ dbg("cache '%s' with attribute value '%s'", path_full, value);
+ strlcpy(attr->value_local, value, sizeof(attr->value_local));
+ attr->value = attr->value_local;
- /* store attribute in cache */
- attr = malloc(sizeof(struct sysfs_attr));
- if (attr == NULL)
- return NULL;
- strlcpy(attr->path, path, sizeof(attr->path));
- strlcpy(attr->value, value, sizeof(attr->value));
- dbg("add to cache '%s' '%s'", attr->path, attr->value);
- list_add(&attr->node, &attr_list);
-
+out:
return attr->value;
}
~ianmdlvl / elogind.git / blobdiff