[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 02/10] util: Introduce qemu_get_runtime_dir()
From: |
Akihiko Odaki |
Subject: |
[PATCH 02/10] util: Introduce qemu_get_runtime_dir() |
Date: |
Thu, 10 Nov 2022 15:23:21 +0900 |
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(+)
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index b9c4307779..86445aad25 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -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
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 59a891b6a8..9a0b3913ff 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -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;
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index a67cb3822e..6ad1bb4bac 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -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);
--
2.38.1
- [PATCH 00/10] util: Introduce qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 01/10] qga: Remove platform GUID definitions, Akihiko Odaki, 2022/11/10
- [PATCH 02/10] util: Introduce qemu_get_runtime_dir(),
Akihiko Odaki <=
- [PATCH 03/10] ivshmem-server: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 04/10] contrib/rdmacm-mux: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 05/10] qga: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 06/10] scsi: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 07/10] virtiofsd: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 09/10] util: Remove qemu_get_local_state_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 10/10] spice-app: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10
- [PATCH 08/10] module: Use qemu_get_runtime_dir(), Akihiko Odaki, 2022/11/10