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Attempt to provide target listing function (WARNING: this function is actually incomplete)

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Summary: Provide a target listing function
Labels: Milestone-1.4.x
Libnfc lacks of target listing function. Actually, applications or libraries based on libnfc have to wrote their own listing function which can provide side effect if two or more of theses libraries are used together in the same application. Plus, some kind of problem could appears during listing multiples targets (i.e. collisions) and this problem should be solved in libnfc (i.e. using NFC chip capabilities), not in applications based on libnfc.
This commit is contained in:
Romuald Conty 2010-07-30 13:27:03 +00:00
parent 7113d1418b
commit 0afaf656fa
3 changed files with 103 additions and 21 deletions
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75
libnfc/nfc.c
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@ -537,6 +537,81 @@ nfc_initiator_select_passive_target(const nfc_device_t* pnd,
return true;
}
bool nfc_initiator_list_passive_targets(nfc_device_t* pnd, const nfc_modulation_t nmInitModulation, nfc_target_info_t anti[], const size_t szTargets, size_t *pszTargetFound )
{
// Let the reader only try once to find a target
nfc_configure (pnd, NDO_INFINITE_SELECT, false);
nfc_target_info_t nti;
bool bCollisionDetected = false;
size_t szTargetFound = 0;
while (nfc_initiator_select_passive_target (pnd, nmInitModulation, NULL, 0, &nti)) {
nfc_initiator_deselect_target(pnd);
if(nmInitModulation == NM_ISO14443A_106) {
if((nti.nai.abtAtqa[0] == 0x00) && (nti.nai.abtAtqa[1] == 0x00)) {
bCollisionDetected = true;
}
}
if(szTargets > szTargetFound) {
memcpy( &(anti[szTargetFound]), &nti, sizeof(nfc_target_info_t) );
}
szTargetFound++;
}
*pszTargetFound = szTargetFound;
DBG("%zu targets was found%s.", *pszTargetFound, bCollisionDetected?" (with SENS_RES collision)":"");
/*
// TODO This chunk of code attempt to retrieve SENS_RES (ATQA) for ISO14443A which collide previously.
// XXX Unfortunately at this stage, I'm not able to REQA each tag correctly to retrieve this SENS_REQ.
// Drop the field for a while
nfc_configure(pnd,NDO_ACTIVATE_FIELD,false);
// Let the reader only try once to find a tag
nfc_configure(pnd,NDO_INFINITE_SELECT,false);
// Configure the CRC and Parity settings
nfc_configure(pnd,NDO_HANDLE_CRC,true);
nfc_configure(pnd,NDO_HANDLE_PARITY,true);
// Enable field so more power consuming cards can power themselves up
nfc_configure(pnd,NDO_ACTIVATE_FIELD,true);
if(bCollisionDetected && (nmInitModulation == NM_ISO14443A_106)) {
// nfc_initiator_select_passive_target(pnd, NM_ISO14443A_106, anti[0].nai.abtUid, anti[0].nai.szUidLen, NULL);
for( size_t n = 0; n < szTargetFound; n++ ) {
size_t szTargetsData;
byte_t abtTargetsData[MAX_FRAME_LEN];
if(!pn53x_InListPassiveTarget(pnd, NM_ISO14443A_106, 2, NULL, 0, abtTargetsData, &szTargetsData)) return false;
DBG("pn53x_InListPassiveTarget(): %d selected target(s)", abtTargetsData[0]);
if(szTargetsData && (abtTargetsData[0] > 0)) {
byte_t* pbtTargetData = abtTargetsData+1;
size_t szTargetData = 5 + *(pbtTargetData + 4); // Tg, SENS_RES (2), SEL_RES, NFCIDLength, NFCID1 (NFCIDLength)
if( (*(pbtTargetData + 3) & 0x40) && ((~(*(pbtTargetData + 3))) & 0x04) ) { // Check if SAK looks like 0bxx1xx0xx, which means compliant with ISO/IEC 14443-4 (= ATS available) (See ISO14443-3 document)
szTargetData += 1 + *(pbtTargetData + szTargetData); // Add ATS length
}
if(!pn53x_decode_target_data(pbtTargetData, szTargetData, pnd->nc, NTT_GENERIC_PASSIVE_106, &nti)) return false;
#ifdef DEBUG
for(size_t n=0;n<sizeof(nti.nai);n++) printf("%02x ", *(((byte_t*)(&nti.nai)) + n));
printf("\n");
#endif // DEBUG
pn53x_InDeselect(pnd, 1);
}
}
}
*/
return true;
}
/**
* @fn nfc_initiator_deselect_target(const nfc_device_t* pnd);
* @brief Deselect a selected passive or emulated tag