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Avoid blocking operations in acr122_list_devices.

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The various SCardConnect() can block if a device is already opened in PC/SC potentially leading to deadlocks.  Avoiding using this and matching the device name against a list of supported devices instead.
This commit is contained in:
Romain Tartiere 2009-11-25 02:55:05 +00:00
parent 21df72269a
commit 92cdc705cd
1 changed files with 10 additions and 15 deletions
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25
src/lib/drivers/acr122.c
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@ -55,6 +55,11 @@
#define ACR122_COMMAND_LEN 266
#define ACR122_RESPONSE_LEN 268
const char *supported_devices[] = {
"ACS ACR122U PICC Interface",
"ACS ACR 38U-CCID",
NULL
};
typedef struct {
SCARDHANDLE hCard;
@ -152,23 +157,13 @@ acr122_list_devices(nfc_device_desc_t pnddDevices[], size_t szDevices, size_t *p
DBG("- %s (pos=%d)", acDeviceNames + szPos, szPos);
// Test if we were able to connect to the "emulator" card
if (SCardConnect(*pscc,acDeviceNames + szPos,SCARD_SHARE_EXCLUSIVE,SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1,&(as.hCard),(void*)&(as.ioCard.dwProtocol)) != SCARD_S_SUCCESS)
{
// Connect to ACR122 firmware version >2.0
if (SCardConnect(*pscc,acDeviceNames + szPos,SCARD_SHARE_DIRECT,0,&(as.hCard),(void*)&(as.ioCard.dwProtocol)) != SCARD_S_SUCCESS)
{
// We can not connect to this device.
continue;
}
bool bSupported = false;
for (int i = 0; supported_devices[i]; i++) {
int l = strlen(supported_devices[i]);
bSupported = 0 == strncmp(supported_devices[i], acDeviceNames + szPos, l);
}
// Configure I/O settings for card communication
as.ioCard.cbPciLength = sizeof(SCARD_IO_REQUEST);
// Retrieve the current firmware version
pcFirmware = acr122_firmware((nfc_device_t*)&as);
if (strstr(pcFirmware,FIRMWARE_TEXT) != NULL)
if (bSupported)
{
// Supported ACR122 device found
strncpy(pnddDevices[*pszDeviceFound].acDevice, acDeviceNames + szPos, BUFSIZ - 1);