Beef up the existing var_tmp() call, rename it to var_tmp_dir() and add a
matching tmp_dir() call (the former looks for the place for /var/tmp, the
latter for /tmp).
Both calls check $TMPDIR, $TEMP, $TMP, following the algorithm Python3 uses.
All dirs are validated before use. secure_getenv() is used in order to limite
exposure in suid binaries.
This also ports a couple of users over to these new APIs.
The var_tmp() return parameter is changed from an allocated buffer the caller
will own to a const string either pointing into environ[], or into a static
const buffer. Given that environ[] is mostly considered constant (and this is
exposed in the very well-known getenv() call), this should be OK behaviour and
allows us to avoid memory allocations in most cases.
Note that $TMPDIR and friends override both /var/tmp and /tmp usage if set.
char *t, *x;
uint64_t u;
unsigned i;
char *t, *x;
uint64_t u;
unsigned i;
assert(ret);
/* Turns this:
assert(ret);
/* Turns this:
* /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
*/
* /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
*/
+ if (!p) {
+ r = tmp_dir(&p);
+ if (r < 0)
+ return r;
+ }
+
int open_tmpfile_unlinkable(const char *directory, int flags) {
char *p;
int open_tmpfile_unlinkable(const char *directory, int flags) {
char *p;
- if (!directory)
- directory = "/tmp";
+ if (!directory) {
+ r = tmp_dir(&directory);
+ if (r < 0)
+ return r;
+ }
/* Returns an unlinked temporary file that cannot be linked into the file system anymore */
/* Returns an unlinked temporary file that cannot be linked into the file system anymore */
}
#if 0 /// UNNEEDED by elogind
}
#if 0 /// UNNEEDED by elogind
-int var_tmp(char **ret) {
- const char *tmp_dir = NULL;
- const char *env_tmp_dir = NULL;
- char *c = NULL;
- int r;
+static int getenv_tmp_dir(const char **ret_path) {
+ const char *n;
+ int r, ret = 0;
- env_tmp_dir = getenv("TMPDIR");
- if (env_tmp_dir != NULL) {
- r = is_dir(env_tmp_dir, true);
- if (r < 0 && r != -ENOENT)
- return r;
- if (r > 0)
- tmp_dir = env_tmp_dir;
+ /* We use the same order of environment variables python uses in tempfile.gettempdir():
+ * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */
+ FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") {
+ const char *e;
+
+ e = secure_getenv(n);
+ if (!e)
+ continue;
+ if (!path_is_absolute(e)) {
+ r = -ENOTDIR;
+ goto next;
+ }
+ if (!path_is_safe(e)) {
+ r = -EPERM;
+ goto next;
+ }
+
+ r = is_dir(e, true);
+ if (r < 0)
+ goto next;
+ if (r == 0) {
+ r = -ENOTDIR;
+ goto next;
+ }
+
+ *ret_path = e;
+ return 1;
+
+ next:
+ /* Remember first error, to make this more debuggable */
+ if (ret >= 0)
+ ret = r;
- if (!tmp_dir)
- tmp_dir = "/var/tmp";
+ if (ret < 0)
+ return ret;
- c = strdup(tmp_dir);
- if (!c)
- return -ENOMEM;
- *ret = c;
+ *ret_path = NULL;
+ return ret;
+}
+static int tmp_dir_internal(const char *def, const char **ret) {
+ const char *e;
+ int r, k;
+
+ assert(def);
+ assert(ret);
+
+ r = getenv_tmp_dir(&e);
+ if (r > 0) {
+ *ret = e;
+ return 0;
+ }
+
+ k = is_dir(def, true);
+ if (k == 0)
+ k = -ENOTDIR;
+ if (k < 0)
+ return r < 0 ? r : k;
+
+ *ret = def;
+int var_tmp_dir(const char **ret) {
+
+ /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus
+ * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is
+ * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR,
+ * making it a variable that overrides all temporary file storage locations. */
+
+ return tmp_dir_internal("/var/tmp", ret);
+}
+
+int tmp_dir(const char **ret) {
+
+ /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually
+ * backed by an in-memory file system: /tmp. */
+
+ return tmp_dir_internal("/tmp", ret);
+}
+
int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
char path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
int r;
int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
char path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
int r;
int get_files_in_directory(const char *path, char ***list);
#if 0 /// UNNEEDED by elogind
int get_files_in_directory(const char *path, char ***list);
#if 0 /// UNNEEDED by elogind
-int var_tmp(char **ret);
+int tmp_dir(const char **ret);
+int var_tmp_dir(const char **ret);
#define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
#define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)