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udev_sysfs: unify symlink resolving

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This commit is contained in:
Kay Sievers
2006-09-19 17:46:04 +02:00
parent bc2a89fad6
commit 82c60ce572
2 changed files with 37 additions and 46 deletions
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udev.h
+1
View File
@@ -113,6 +113,7 @@ extern struct sysfs_device *sysfs_device_get(const char *devpath);
extern struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev);
extern struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device *dev, const char *subsystem);
extern char *sysfs_attr_get_value(const char *devpath, const char *attr_name);
extern int sysfs_resolve_link(char *path, size_t size);
/* udev_node.c */
extern int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid);
udev_sysfs.c
+36 -46
View File
@@ -112,6 +112,38 @@ void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath,
dbg("kernel_number='%s'", dev->kernel_number);
}
int sysfs_resolve_link(char *devpath, size_t size)
{
char link_path[PATH_SIZE];
char link_target[PATH_SIZE];
int len;
int i;
int back;
strlcpy(link_path, sysfs_path, sizeof(link_path));
strlcat(link_path, devpath, sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len <= 0)
return -1;
link_target[len] = '\0';
dbg("path link '%s' points to '%s'", devpath, link_target);
for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
;
dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
for (i = 0; i <= back; i++) {
char *pos = strrchr(devpath, '/');
if (pos == NULL)
return -1;
pos[0] = '\0';
}
dbg("after moving back '%s'", devpath);
strlcat(devpath, "/", size);
strlcat(devpath, &link_target[back * 3], size);
return 0;
}
struct sysfs_device *sysfs_device_get(const char *devpath)
{
char path[PATH_SIZE];
@@ -144,27 +176,8 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
return NULL;
}
if (S_ISLNK(statbuf.st_mode)) {
int i;
int back;
len = readlink(path, link_target, sizeof(link_target));
if (len <= 0)
if (sysfs_resolve_link(devpath_real, sizeof(devpath_real)) != 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) {
@@ -247,12 +260,7 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
{
char parent_devpath[PATH_SIZE];
char device_link[PATH_SIZE];
char device_link_target[PATH_SIZE];
char *pos;
int i;
int len;
int back;
dbg("open '%s'", dev->devpath);
@@ -298,28 +306,10 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
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));
strlcat(parent_devpath, "/device", sizeof(parent_devpath));
if (sysfs_resolve_link(parent_devpath, sizeof(parent_devpath)) != 0)
return NULL;
/* get parent and remember it */
dev->parent = sysfs_device_get(parent_devpath);