util: add getxattr helper apis

To get xattr of given path or fd on newly allocated buffer, add new
helper api getxattr_malloc() and fgetxattr_malloc().
This commit is contained in:
WaLyong Cho
2015-08-04 21:09:48 +09:00
committed by WaLyong Cho
parent 13925e4ce8
commit 7b9c9ab810
2 changed files with 73 additions and 0 deletions
+70
View File
@@ -6603,3 +6603,73 @@ int reset_uid_gid(void) {
return 0;
}
int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink) {
char *v;
size_t l;
ssize_t n;
assert(path);
assert(name);
assert(value);
for (l = 100; ; l = (size_t) n + 1) {
v = new0(char, l);
if (!v)
return -ENOMEM;
if (allow_symlink)
n = lgetxattr(path, name, v, l);
else
n = getxattr(path, name, v, l);
if (n >= 0 && (size_t) n < l) {
*value = v;
return n;
}
free(v);
if (n < 0 && errno != ERANGE)
return -errno;
if (allow_symlink)
n = lgetxattr(path, name, NULL, 0);
else
n = getxattr(path, name, NULL, 0);
if (n < 0)
return -errno;
}
}
int fgetxattr_malloc(int fd, const char *name, char **value) {
char *v;
size_t l;
ssize_t n;
assert(fd >= 0);
assert(name);
assert(value);
for (l = 100; ; l = (size_t) n + 1) {
v = new0(char, l);
if (!v)
return -ENOMEM;
n = fgetxattr(fd, name, v, l);
if (n >= 0 && (size_t) n < l) {
*value = v;
return n;
}
free(v);
if (n < 0 && errno != ERANGE)
return -errno;
n = fgetxattr(fd, name, NULL, 0);
if (n < 0)
return -errno;
}
}
+3
View File
@@ -919,3 +919,6 @@ int parse_mode(const char *s, mode_t *ret);
int mount_move_root(const char *path);
int reset_uid_gid(void);
int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
int fgetxattr_malloc(int fd, const char *name, char **value);