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add better windows error handling (#388)
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@Phyllostachys
Phyllostachys authored May 2, 2022
1 parent 68bcbfc commit 08563a0
Showing 1 changed file with 143 additions and 35 deletions.
178 changes: 143 additions & 35 deletions windows/hid.c
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Original file line number Diff line number Diff line change
Expand Up @@ -178,8 +178,7 @@ struct hid_device_ {
size_t input_report_length;
USHORT feature_report_length;
unsigned char *feature_buf;
void *last_error_str;
DWORD last_error_num;
wchar_t *last_error_str;
BOOL read_pending;
char *read_buf;
OVERLAPPED ol;
Expand All @@ -198,7 +197,6 @@ static hid_device *new_hid_device()
dev->feature_report_length = 0;
dev->feature_buf = NULL;
dev->last_error_str = NULL;
dev->last_error_num = 0;
dev->read_pending = FALSE;
dev->read_buf = NULL;
memset(&dev->ol, 0, sizeof(dev->ol));
Expand All @@ -215,42 +213,101 @@ static void free_hid_device(hid_device *dev)
CloseHandle(dev->ol.hEvent);
CloseHandle(dev->write_ol.hEvent);
CloseHandle(dev->device_handle);
LocalFree(dev->last_error_str);
free(dev->last_error_str);
dev->last_error_str = NULL;
free(dev->write_buf);
free(dev->feature_buf);
free(dev->read_buf);
hid_free_enumeration(dev->device_info);
free(dev);
}

static void register_error(hid_device *dev, const char *op)
static void register_winapi_error_to_buffer(wchar_t **error_buffer, const WCHAR *op)
{
WCHAR *ptr, *msg;
(void)op;
FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
if (!error_buffer)
return;

free(*error_buffer);
*error_buffer = NULL;

/* Only clear out error messages if NULL is passed into op */
if (!op) {
return;
}

WCHAR system_err_buf[1024];
DWORD error_code = GetLastError();

DWORD system_err_len = FormatMessageW(
FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
GetLastError(),
error_code,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPWSTR)&msg, 0/*sz*/,
system_err_buf, ARRAYSIZE(system_err_buf),
NULL);

DWORD op_len = (DWORD)wcslen(op);

DWORD op_prefix_len =
op_len
+ 15 /*: (0x00000000) */
;
DWORD msg_len =
+ op_prefix_len
+ system_err_len
;

*error_buffer = (WCHAR *)calloc(msg_len + 1, sizeof (WCHAR));
WCHAR *msg = *error_buffer;

if (!msg)
return;

int printf_written = swprintf(msg, msg_len + 1, L"%.*ls: (0x%08X) %.*ls", op_len, op, error_code, system_err_len, system_err_buf);

if (printf_written < 0)
{
/* Highly unlikely */
msg[0] = L'\0';
return;
}

/* Get rid of the CR and LF that FormatMessage() sticks at the
end of the message. Thanks Microsoft! */
ptr = msg;
while (*ptr) {
if (*ptr == L'\r') {
*ptr = L'\0';
break;
}
ptr++;
while(msg[msg_len-1] == L'\r' || msg[msg_len-1] == L'\n' || msg[msg_len-1] == L' ')
{
msg[msg_len-1] = L'\0';
msg_len--;
}
}

static void register_winapi_error(hid_device *dev, const WCHAR *op)
{
if (!dev)
return;

register_winapi_error_to_buffer(&dev->last_error_str, op);
}

static void register_string_error_to_buffer(wchar_t **error_buffer, const WCHAR *string_error)
{
if (!error_buffer)
return;

free(*error_buffer);
*error_buffer = NULL;

if (string_error) {
*error_buffer = _wcsdup(string_error);
}
}

static void register_string_error(hid_device *dev, const WCHAR *string_error)
{
if (!dev)
return;

/* Store the message off in the Device entry so that
the hid_error() function can pick it up. */
LocalFree(dev->last_error_str);
dev->last_error_str = msg;
register_string_error_to_buffer(&dev->last_error_str, string_error);
}

static HANDLE open_device(const wchar_t *path, BOOL open_rw)
Expand Down Expand Up @@ -656,6 +713,10 @@ HID_API_EXPORT hid_device * HID_API_CALL hid_open(unsigned short vendor_id, unsi
hid_device *handle = NULL;

devs = hid_enumerate(vendor_id, product_id);
if (!devs) {
return NULL;
}

cur_dev = devs;
while (cur_dev) {
if (cur_dev->vendor_id == vendor_id &&
Expand Down Expand Up @@ -759,7 +820,7 @@ int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *
unsigned char *buf;

if (!data || (length==0)) {
register_error(dev, "Zero length buffer");
register_string_error(dev, L"Zero buffer/length");
return function_result;
}

Expand All @@ -786,7 +847,7 @@ int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *
if (!res) {
if (GetLastError() != ERROR_IO_PENDING) {
/* WriteFile() failed. Return error. */
register_error(dev, "WriteFile");
register_winapi_error(dev, L"WriteFile");
goto end_of_function;
}
overlapped = TRUE;
Expand All @@ -798,7 +859,7 @@ int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *
res = WaitForSingleObject(dev->write_ol.hEvent, 1000);
if (res != WAIT_OBJECT_0) {
/* There was a Timeout. */
register_error(dev, "WriteFile/WaitForSingleObject Timeout");
register_winapi_error(dev, L"hid_write/WaitForSingleObject");
goto end_of_function;
}

Expand All @@ -809,7 +870,7 @@ int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *
}
else {
/* The Write operation failed. */
register_error(dev, "WriteFile");
register_winapi_error(dev, L"hid_write/GetOverlappedResult");
goto end_of_function;
}
}
Expand Down Expand Up @@ -840,6 +901,7 @@ int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char
if (GetLastError() != ERROR_IO_PENDING) {
/* ReadFile() has failed.
Clean up and return error. */
register_winapi_error(dev, L"ReadFile");
CancelIo(dev->device_handle);
dev->read_pending = FALSE;
goto end_of_function;
Expand Down Expand Up @@ -886,10 +948,12 @@ int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char
memcpy(data, dev->read_buf, copy_len);
}
}
if (!res) {
register_winapi_error(dev, L"hid_read_timeout/GetOverlappedResult");
}

end_of_function:
if (!res) {
register_error(dev, "GetOverlappedResult");
return -1;
}

Expand Down Expand Up @@ -933,7 +997,7 @@ int HID_API_EXPORT HID_API_CALL hid_send_feature_report(hid_device *dev, const u
res = HidD_SetFeature(dev->device_handle, (PVOID)buf, (DWORD) length_to_send);

if (!res) {
register_error(dev, "HidD_SetFeature");
register_winapi_error(dev, L"HidD_SetFeature");
return -1;
}

Expand All @@ -957,7 +1021,7 @@ static int hid_get_report(hid_device *dev, DWORD report_type, unsigned char *dat
if (!res) {
if (GetLastError() != ERROR_IO_PENDING) {
/* DeviceIoControl() failed. Return error. */
register_error(dev, "Get Input/Feature Report DeviceIoControl");
register_winapi_error(dev, L"Get Input/Feature Report DeviceIoControl");
return -1;
}
}
Expand All @@ -967,7 +1031,7 @@ static int hid_get_report(hid_device *dev, DWORD report_type, unsigned char *dat
res = GetOverlappedResult(dev->device_handle, &ol, &bytes_returned, TRUE/*wait*/);
if (!res) {
/* The operation failed. */
register_error(dev, "Get Input/Feature Report GetOverLappedResult");
register_winapi_error(dev, L"Get Input/Feature Report GetOverLappedResult");
return -1;
}

Expand Down Expand Up @@ -1004,8 +1068,17 @@ void HID_API_EXPORT HID_API_CALL hid_close(hid_device *dev)

int HID_API_EXPORT_CALL HID_API_CALL hid_get_manufacturer_string(hid_device *dev, wchar_t *string, size_t maxlen)
{
if (!dev->device_info || !string || !maxlen)
if (!dev->device_info)
{
register_string_error(dev, L"NULL device/info");
return -1;
}

if (!string || !maxlen)
{
register_string_error(dev, L"Zero buffer/length");
return -1;
}

wcsncpy(string, dev->device_info->manufacturer_string, maxlen);
string[maxlen] = L'\0';
Expand All @@ -1015,8 +1088,18 @@ int HID_API_EXPORT_CALL HID_API_CALL hid_get_manufacturer_string(hid_device *dev

int HID_API_EXPORT_CALL HID_API_CALL hid_get_product_string(hid_device *dev, wchar_t *string, size_t maxlen)
{
if (!dev->device_info || !string || !maxlen)
if (!dev->device_info)
{
register_string_error(dev, L"NULL device/info");
return -1;
}

if (!string || !maxlen)
{
register_string_error(dev, L"Zero buffer/length");
return -1;
}


wcsncpy(string, dev->device_info->product_string, maxlen);
string[maxlen] = L'\0';
Expand All @@ -1026,8 +1109,18 @@ int HID_API_EXPORT_CALL HID_API_CALL hid_get_product_string(hid_device *dev, wch

int HID_API_EXPORT_CALL HID_API_CALL hid_get_serial_number_string(hid_device *dev, wchar_t *string, size_t maxlen)
{
if (!dev->device_info || !string || !maxlen)
if (!dev->device_info)
{
register_string_error(dev, L"NULL device/info");
return -1;
}

if (!string || !maxlen)
{
register_string_error(dev, L"Zero buffer/length");
return -1;
}


wcsncpy(string, dev->device_info->serial_number, maxlen);
string[maxlen] = L'\0';
Expand All @@ -1041,7 +1134,7 @@ int HID_API_EXPORT_CALL HID_API_CALL hid_get_indexed_string(hid_device *dev, int

res = HidD_GetIndexedString(dev->device_handle, string_index, string, sizeof(wchar_t) * (DWORD) MIN(maxlen, MAX_STRING_WCHARS));
if (!res) {
register_error(dev, "HidD_GetIndexedString");
register_winapi_error(dev, L"HidD_GetIndexedString");
return -1;
}

Expand All @@ -1057,28 +1150,43 @@ int HID_API_EXPORT_CALL hid_winapi_get_container_id(hid_device *dev, GUID *conta
ULONG len;

if (!container_id)
{
register_string_error(dev, L"Invalid Container ID");
return -1;
}

interface_path = hid_internal_UTF8toUTF16(dev->device_info->path);
if (!interface_path)
{
register_string_error(dev, L"Path conversion failure");
goto end;
}

/* Get the device id from interface path */
device_id = hid_internal_get_device_interface_property(interface_path, &DEVPKEY_Device_InstanceId, DEVPROP_TYPE_STRING);
if (!device_id)
{
register_string_error(dev, L"Failed to get device interface property InstanceId");
goto end;
}

/* Open devnode from device id */
cr = CM_Locate_DevNodeW(&dev_node, (DEVINSTID_W)device_id, CM_LOCATE_DEVNODE_NORMAL);
if (cr != CR_SUCCESS)
{
register_string_error(dev, L"Failed to locate device node");
goto end;
}

/* Get the container id from devnode */
len = sizeof(*container_id);
cr = CM_Get_DevNode_PropertyW(dev_node, &DEVPKEY_Device_ContainerId, &property_type, (PBYTE)container_id, &len, 0);
if (cr == CR_SUCCESS && property_type != DEVPROP_TYPE_GUID)
cr = CR_FAILURE;

if (cr != CR_SUCCESS)
register_string_error(dev, L"Failed to read ContainerId property from device node");

end:
free(interface_path);
free(device_id);
Expand Down

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