@@ -565,6 +565,18 @@ void qemu_set_cloexec(int fd);
*/
char *qemu_get_local_state_dir(void);
+/**
+ * qemu_get_runtime_dir:
+ *
+ * Return a dynamically allocated directory path that is appropriate for storing
+ * runtime files. It corresponds to "run" directory in Unix, and uses
+ * $XDG_RUNTIME_DIR if available.
+ *
+ * The caller is responsible for releasing the value returned with g_free()
+ * after use.
+ */
+char *qemu_get_runtime_dir(void);
+
/**
* qemu_getauxval:
* @type: the auxiliary vector key to lookup
@@ -279,6 +279,17 @@ qemu_get_local_state_dir(void)
return get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR);
}
+char *
+qemu_get_runtime_dir(void)
+{
+ char *env = getenv("XDG_RUNTIME_DIR");
+ if (env) {
+ return g_strdup(env);
+ }
+
+ return get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run");
+}
+
void qemu_set_tty_echo(int fd, bool echo)
{
struct termios tty;
@@ -31,6 +31,8 @@
*/
#include "qemu/osdep.h"
+#include <shlobj.h>
+#include <wchar.h>
#include <windows.h>
#include "qapi/error.h"
#include "qemu/main-loop.h"
@@ -241,6 +243,30 @@ qemu_get_local_state_dir(void)
return g_strdup(data_dirs[0]);
}
+char *
+qemu_get_runtime_dir(void)
+{
+ size_t size = GetEnvironmentVariableA("XDG_RUNTIME_DIR", NULL, 0);
+ if (size) {
+ char *env = g_malloc(size);
+ GetEnvironmentVariableA("XDG_RUNTIME_DIR", env, size);
+ return env;
+ }
+
+ PWSTR wpath;
+ const wchar_t *cwpath;
+ if (!SHGetKnownFolderPath(&FOLDERID_LocalAppData, KF_FLAG_DEFAULT, NULL, &wpath)) {
+ cwpath = wpath;
+ size = wcsrtombs(NULL, &cwpath, 0, &(mbstate_t){0}) + 1;
+ char *path = g_malloc(size);
+ wcsrtombs(path, &cwpath, size, &(mbstate_t){0});
+ CoTaskMemFree(wpath);
+ return path;
+ }
+
+ return get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run");
+}
+
void qemu_set_tty_echo(int fd, bool echo)
{
HANDLE handle = (HANDLE)_get_osfhandle(fd);
qemu_get_runtime_dir() returns a dynamically allocated directory path that is appropriate for storing runtime files. It corresponds to "run" directory in Unix. With a tree-wide search, it was found that there are several cases where such a functionality is implemented so let's have one as a common utlity function. A notable feature of qemu_get_runtime_dir() is that it uses $XDG_RUNTIME_DIR if available. While the function is often called by executables which requires root privileges, it is still possible that they are called from a user without privilege to write the system runtime directory. In fact, I decided to write this patch when I ran virtiofsd in a Linux namespace created by a normal user and realized it tries to write the system runtime directory, not writable in this case. $XDG_RUNTIME_DIR should provide a writable directory in such cases. This function does not use qemu_get_local_state_dir() or its logic for Windows. Actually the implementation of qemu_get_local_state_dir() for Windows seems not right as it calls g_get_system_data_dirs(), which refers to $XDG_DATA_DIRS. In Unix terminology, it is basically "/usr/share", not "/var", which qemu_get_local_state_dir() is intended to provide. Instead, this function try to use the following in order: - $XDG_RUNTIME_DIR - LocalAppData folder - get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run") This function does not use g_get_user_runtime_dir() either as it falls back to g_get_user_cache_dir() when $XDG_DATA_DIRS is not available. In the case, we rather use: get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run") Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> --- include/qemu/osdep.h | 12 ++++++++++++ util/oslib-posix.c | 11 +++++++++++ util/oslib-win32.c | 26 ++++++++++++++++++++++++++ 3 files changed, 49 insertions(+)