* [PATCH v4 1/2] tap-win32: cleanup leaked handles on tap close
2025-10-17 11:59 [PATCH v4 0/2] tap-win32: fix multiple tap support Gal Horowitz
@ 2025-10-17 11:59 ` Gal Horowitz
2025-10-17 11:59 ` [PATCH v4 2/2] tap-win32: allocate separate tap state for each instance Gal Horowitz
1 sibling, 0 replies; 3+ messages in thread
From: Gal Horowitz @ 2025-10-17 11:59 UTC (permalink / raw)
To: qemu-devel; +Cc: Jason Wang, Stefan Weil, Gal Horowitz
Currently, all handles owned by a win32 tap are leaked on cleanup.
This commit ensures that the handles are properly closed upon tap
cleanup. A check for the return value of CreateThread is also added.
Signed-off-by: Gal Horowitz <galush.horowitz@gmail.com>
---
net/tap-win32.c | 40 +++++++++++++++++++++++++++++++++-------
1 file changed, 33 insertions(+), 7 deletions(-)
diff --git a/net/tap-win32.c b/net/tap-win32.c
index 38baf90e0b3f121f74eb32f1bff779c84ce03114..ae25e5a883343bf9f570d0f382b8c64712d95242 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -104,6 +104,7 @@ typedef struct tap_win32_overlapped {
HANDLE output_queue_semaphore;
HANDLE free_list_semaphore;
HANDLE tap_semaphore;
+ HANDLE thread_handle;
CRITICAL_SECTION output_queue_cs;
CRITICAL_SECTION free_list_cs;
OVERLAPPED read_overlapped;
@@ -589,6 +590,26 @@ static void tap_win32_free_buffer(tap_win32_overlapped_t *overlapped,
put_buffer_on_free_list(overlapped, buffer);
}
+static void tap_win32_close(tap_win32_overlapped_t *overlapped)
+{
+ TerminateThread(overlapped->thread_handle, 0);
+ CloseHandle(overlapped->thread_handle);
+
+ CloseHandle(overlapped->tap_semaphore);
+ CloseHandle(overlapped->free_list_semaphore);
+ CloseHandle(overlapped->output_queue_semaphore);
+
+ DeleteCriticalSection(&overlapped->free_list_cs);
+ DeleteCriticalSection(&overlapped->output_queue_cs);
+
+ CloseHandle(overlapped->write_event);
+ CloseHandle(overlapped->read_event);
+
+ CloseHandle(overlapped->handle);
+
+ g_free(overlapped);
+}
+
static int tap_win32_open(tap_win32_overlapped_t **phandle,
const char *preferred_name)
{
@@ -604,7 +625,6 @@ static int tap_win32_open(tap_win32_overlapped_t **phandle,
unsigned long debug;
} version;
DWORD version_len;
- DWORD idThread;
if (preferred_name != NULL) {
snprintf(name_buffer, sizeof(name_buffer), "%s", preferred_name);
@@ -642,15 +662,22 @@ static int tap_win32_open(tap_win32_overlapped_t **phandle,
}
if (!tap_win32_set_status(handle, TRUE)) {
+ CloseHandle(handle);
return -1;
}
tap_win32_overlapped_init(&tap_overlapped, handle);
- *phandle = &tap_overlapped;
+ tap_overlapped.thread_handle = CreateThread(NULL, 0,
+ tap_win32_thread_entry, (LPVOID)&tap_overlapped, 0, NULL);
+
+ if (tap_overlapped->thread_handle == NULL) {
+ tap_win32_close(tap_overlapped);
+ return -1;
+ }
+
+ *phandle = tap_overlapped;
- CreateThread(NULL, 0, tap_win32_thread_entry,
- (LPVOID)&tap_overlapped, 0, &idThread);
return 0;
}
@@ -667,9 +694,8 @@ static void tap_cleanup(NetClientState *nc)
qemu_del_wait_object(s->handle->tap_semaphore, NULL, NULL);
- /* FIXME: need to kill thread and close file handle:
- tap_win32_close(s);
- */
+ tap_win32_close(s->handle);
+ s->handle = NULL;
}
static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v4 2/2] tap-win32: allocate separate tap state for each instance
2025-10-17 11:59 [PATCH v4 0/2] tap-win32: fix multiple tap support Gal Horowitz
2025-10-17 11:59 ` [PATCH v4 1/2] tap-win32: cleanup leaked handles on tap close Gal Horowitz
@ 2025-10-17 11:59 ` Gal Horowitz
1 sibling, 0 replies; 3+ messages in thread
From: Gal Horowitz @ 2025-10-17 11:59 UTC (permalink / raw)
To: qemu-devel; +Cc: Jason Wang, Stefan Weil, Gal Horowitz
A static global is incorrectly used as the tap state for all win32 taps
created. Instead, we now allocate per win32 tap.
Signed-off-by: Gal Horowitz <galush.horowitz@gmail.com>
---
net/tap-win32.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/net/tap-win32.c b/net/tap-win32.c
index ae25e5a883343bf9f570d0f382b8c64712d95242..3d7227fcf47ff45bbdbf60cd5b86ab8f8913b941 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -115,8 +115,6 @@ typedef struct tap_win32_overlapped {
tun_buffer_t* output_queue_back;
} tap_win32_overlapped_t;
-static tap_win32_overlapped_t tap_overlapped;
-
static tun_buffer_t* get_buffer_from_free_list(tap_win32_overlapped_t* const overlapped)
{
tun_buffer_t* buffer = NULL;
@@ -403,8 +401,10 @@ static int tap_win32_set_status(HANDLE handle, int status)
&status, sizeof (status), &len, NULL);
}
-static void tap_win32_overlapped_init(tap_win32_overlapped_t* const overlapped, const HANDLE handle)
+static tap_win32_overlapped_t *tap_win32_overlapped_new(const HANDLE handle)
{
+ tap_win32_overlapped_t *overlapped = g_new0(tap_win32_overlapped_t, 1);
+
overlapped->handle = handle;
overlapped->read_event = CreateEvent(NULL, FALSE, FALSE, NULL);
@@ -455,6 +455,8 @@ static void tap_win32_overlapped_init(tap_win32_overlapped_t* const overlapped,
overlapped->tap_semaphore = CreateSemaphore(NULL, 0, TUN_MAX_BUFFER_COUNT, NULL);
if(!overlapped->tap_semaphore)
fprintf(stderr, "error creating tap_semaphore.\n");
+
+ return overlapped;
}
static int tap_win32_write(tap_win32_overlapped_t *overlapped,
@@ -625,6 +627,7 @@ static int tap_win32_open(tap_win32_overlapped_t **phandle,
unsigned long debug;
} version;
DWORD version_len;
+ tap_win32_overlapped_t *tap_overlapped = NULL;
if (preferred_name != NULL) {
snprintf(name_buffer, sizeof(name_buffer), "%s", preferred_name);
@@ -666,10 +669,10 @@ static int tap_win32_open(tap_win32_overlapped_t **phandle,
return -1;
}
- tap_win32_overlapped_init(&tap_overlapped, handle);
+ tap_overlapped = tap_win32_overlapped_new(handle);
- tap_overlapped.thread_handle = CreateThread(NULL, 0,
- tap_win32_thread_entry, (LPVOID)&tap_overlapped, 0, NULL);
+ tap_overlapped->thread_handle = CreateThread(NULL, 0,
+ tap_win32_thread_entry, (LPVOID)tap_overlapped, 0, NULL);
if (tap_overlapped->thread_handle == NULL) {
tap_win32_close(tap_overlapped);
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread