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sysfs: add device lookup by $SUBSYSYTEM:$KERNEL

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This commit is contained in:
Kay Sievers 2007-06-02 09:43:57 +02:00
parent d419e96238
commit 4722274ca0
1 changed files with 92 additions and 0 deletions
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92
udev_sysfs.c
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@ -429,3 +429,95 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
out:
return attr->value;
}
int sysfs_lookup_devpath_by_subsys_id(char *devpath_full, size_t len, const char *subsystem, const char *id)
{
size_t sysfs_len;
char path_full[PATH_SIZE];
char *path;
struct stat statbuf;
sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
path = &path_full[sysfs_len];
if (strcmp(subsystem, "subsystem") == 0) {
strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
goto out;
}
if (strcmp(subsystem, "module") == 0) {
strlcpy(path, "/module/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
goto out;
}
if (strcmp(subsystem, "drivers") == 0) {
char subsys[NAME_SIZE];
char *driver;
strlcpy(subsys, id, sizeof(subsys));
driver = strchr(subsys, ':');
if (driver != NULL) {
driver[0] = '\0';
driver = &driver[1];
strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
strlcat(path, subsys, sizeof(path_full) - sysfs_len);
strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
strlcat(path, driver, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
strlcat(path, subsys, sizeof(path_full) - sysfs_len);
strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
strlcat(path, driver, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
}
goto out;
}
strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
strlcat(path, "/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
strlcat(path, id, sizeof(path_full) - sysfs_len);
if (stat(path_full, &statbuf) == 0)
goto found;
out:
return 0;
found:
if (S_ISLNK(statbuf.st_mode))
sysfs_resolve_link(path, sizeof(path_full) - sysfs_len);
strlcpy(devpath_full, path, len);
return 1;
}