libnfc/libnfc/nfc-emulation.c
Philippe Teuwen 618ca1e92b Remove dead code
Problem reported by Coverity:
at_most: At condition "io_res < 0", the value of "io_res" must be at most -1.
dead_error_condition: The condition "io_res < 0" must be true.
CID 1090328 (#1 of 1): Logically dead code (DEADCODE)
  dead_error_line: Execution cannot reach this expression "0" inside statement "return (io_res < 0) ? io_re...".
2013-09-22 03:13:09 +02:00

76 lines
2.5 KiB
C

/*-
* Free/Libre Near Field Communication (NFC) library
*
* Libnfc historical contributors:
* Copyright (C) 2009 Roel Verdult
* Copyright (C) 2009-2013 Romuald Conty
* Copyright (C) 2010-2012 Romain Tartière
* Copyright (C) 2010-2013 Philippe Teuwen
* Copyright (C) 2012-2013 Ludovic Rousseau
* See AUTHORS file for a more comprehensive list of contributors.
* Additional contributors of this file:
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file nfc-emulation.c
* @brief Provide a small API to ease emulation in libnfc
*/
#include <nfc/nfc.h>
#include <nfc/nfc-emulation.h>
#include "iso7816.h"
/** @ingroup emulation
* @brief Emulate a target
* @return Returns 0 on success, otherwise returns libnfc's error code (negative value).
*
* @param pnd \a nfc_device struct pointer that represents currently used device
* @param emulator \nfc_emulator struct point that handles input/output functions
*
* If timeout equals to 0, the function blocks indefinitely (until an error is raised or function is completed)
* If timeout equals to -1, the default timeout will be used
*/
int
nfc_emulate_target(nfc_device *pnd, struct nfc_emulator *emulator, const int timeout)
{
uint8_t abtRx[ISO7816_SHORT_R_APDU_MAX_LEN];
uint8_t abtTx[ISO7816_SHORT_C_APDU_MAX_LEN];
int res;
if ((res = nfc_target_init(pnd, emulator->target, abtRx, sizeof(abtRx), timeout)) < 0) {
return res;
}
size_t szRx = res;
int io_res = res;
while (io_res >= 0) {
io_res = emulator->state_machine->io(emulator, abtRx, szRx, abtTx, sizeof(abtTx));
if (io_res > 0) {
if ((res = nfc_target_send_bytes(pnd, abtTx, io_res, timeout)) < 0) {
return res;
}
}
if (io_res >= 0) {
if ((res = nfc_target_receive_bytes(pnd, abtRx, sizeof(abtRx), timeout)) < 0) {
return res;
}
szRx = res;
}
}
return io_res;
}