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Merge remote-tracking branch 'dechamps/windevice' into 1.1

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This commit is contained in:
Guus Sliepen 2015-04-12 15:36:50 +02:00
commit f500a3d4e6
1 changed files with 40 additions and 5 deletions
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45
src/mingw/device.c
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@ -38,7 +38,9 @@ int device_fd = -1;
static HANDLE device_handle = INVALID_HANDLE_VALUE;
static io_t device_read_io;
static OVERLAPPED device_read_overlapped;
static OVERLAPPED device_write_overlapped;
static vpn_packet_t device_read_packet;
static vpn_packet_t device_write_packet;
char *device = NULL;
char *iface = NULL;
static char *device_info = NULL;
@ -200,8 +202,12 @@ static void enable_device(void) {
DWORD len;
DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL));
device_read_overlapped.hEvent = device_read_io.event;
/* We don't use the write event directly, but GetOverlappedResult() does, internally. */
device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent);
device_issue_read();
}
@ -210,10 +216,22 @@ static void disable_device(void) {
io_del(&device_read_io);
CancelIo(device_handle);
/* According to MSDN, CancelIo() does not necessarily wait for the operation to complete.
To prevent race conditions, make sure the operation is complete
before we close the event it's referencing. */
DWORD len;
if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED)
logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s read to cancel: %s", device_info, device, winerror(GetLastError()));
if(device_write_packet.len > 0 && !GetOverlappedResult(device_handle, &device_write_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED)
logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s write to cancel: %s", device_info, device, winerror(GetLastError()));
device_write_packet.len = 0;
CloseHandle(device_read_overlapped.hEvent);
CloseHandle(device_write_overlapped.hEvent);
ULONG status = 0;
DWORD len;
DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
}
@ -231,12 +249,29 @@ static bool read_packet(vpn_packet_t *packet) {
static bool write_packet(vpn_packet_t *packet) {
DWORD outlen;
OVERLAPPED overlapped = {0};
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
packet->len, device_info);
if(!WriteFile(device_handle, DATA(packet), packet->len, &outlen, &overlapped)) {
if(device_write_packet.len > 0) {
/* Make sure the previous write operation is finished before we start the next one;
otherwise we end up with multiple write ops referencing the same OVERLAPPED structure,
which according to MSDN is a no-no. */
if(!GetOverlappedResult(device_handle, &device_write_overlapped, &outlen, FALSE)) {
int log_level = (GetLastError() == ERROR_IO_INCOMPLETE) ? DEBUG_TRAFFIC : DEBUG_ALWAYS;
logger(log_level, LOG_ERR, "Error while checking previous write to %s %s: %s", device_info, device, winerror(GetLastError()));
return false;
}
}
/* Copy the packet, since the write operation might still be ongoing after we return. */
memcpy(&device_write_packet, packet, sizeof *packet);
if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped))
device_write_packet.len = 0;
else if (GetLastError() != ERROR_IO_PENDING) {
logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
return false;
}