PN532 NFC library for Seeed Studio's NFC Shield

Fork of PN532 by Yihui Xiong

Revision:
3:4189a10038e6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/llcp.cpp	Thu Nov 21 04:30:49 2013 +0000
@@ -0,0 +1,307 @@
+
+#include "llcp.h"
+#include "PN532_debug.h"
+
+// LLCP PDU Type Values
+#define PDU_SYMM    0x00
+#define PDU_PAX     0x01
+#define PDU_CONNECT 0x04
+#define PDU_DISC    0x05
+#define PDU_CC      0x06
+#define PDU_DM      0x07
+#define PDU_I       0x0c
+#define PDU_RR      0x0d
+
+uint8_t LLCP::SYMM_PDU[2] = {0, 0};
+
+inline uint8_t getPType(const uint8_t *buf)
+{
+	return ((buf[0] & 0x3) << 2) + (buf[1] >> 6);
+}
+
+inline uint8_t getSSAP(const uint8_t *buf)
+{
+	return  buf[1] & 0x3f;
+}
+
+inline uint8_t getDSAP(const uint8_t *buf)
+{
+	return buf[0] >> 2;
+}
+
+int8_t LLCP::activate(uint16_t timeout)
+{
+	return link.activateAsTarget(timeout);
+}
+
+int8_t LLCP::waitForConnection(uint16_t timeout)
+{
+	uint8_t type;
+
+	ns = 0;
+	nr = 0;
+
+	// Get CONNECT PDU
+	DMSG("wait for a CONNECT PDU\n");
+	do {
+		if (2 > link.read(headerBuf, headerBufLen)) {
+			return -1;
+		}
+
+		type = getPType(headerBuf);
+		if (PDU_CONNECT == type) {
+			break;
+		} else if (PDU_SYMM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return -2;
+			}
+		} else {
+			return -3;
+		}
+
+	} while (1);
+
+	// Put CC PDU
+	DMSG("put a CC(Connection Complete) PDU to response the CONNECT PDU\n");
+	ssap = getDSAP(headerBuf);
+	dsap = getSSAP(headerBuf);
+	headerBuf[0] = (dsap << 2) + ((PDU_CC >> 2) & 0x3);
+	headerBuf[1] = ((PDU_CC & 0x3) << 6) + ssap;
+	if (!link.write(headerBuf, 2)) {
+		return -2;
+	}
+
+	return 1;
+}
+
+int8_t LLCP::waitForDisconnection(uint16_t timeout)
+{
+	uint8_t type;
+
+	// Get DISC PDU
+	DMSG("wait for a DISC PDU\n");
+	do {
+		if (2 > link.read(headerBuf, headerBufLen)) {
+			return -1;
+		}
+
+		type = getPType(headerBuf);
+		if (PDU_DISC == type) {
+			break;
+		} else if (PDU_SYMM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return -2;
+			}
+		} else {
+			return -3;
+		}
+
+	} while (1);
+
+	// Put DM PDU
+	DMSG("put a DM(Disconnect Mode) PDU to response the DISC PDU\n");
+	// ssap = getDSAP(headerBuf);
+	// dsap = getSSAP(headerBuf);
+	headerBuf[0] = (dsap << 2) + (PDU_DM >> 2);
+	headerBuf[1] = ((PDU_DM & 0x3) << 6) + ssap;
+	if (!link.write(headerBuf, 2)) {
+		return -2;
+	}
+
+	return 1;
+}
+
+int8_t LLCP::connect(uint16_t timeout)
+{
+	uint8_t type;
+
+	ns = 0;
+	nr = 0;
+
+	// try to get a SYMM PDU
+	if (2 > link.read(headerBuf, headerBufLen)) {
+		return -1;
+	}
+	type = getPType(headerBuf);
+	if (PDU_SYMM != type) {
+		return -1;
+	}
+
+	dsap = LLCP_DEFAULT_DSAP;
+	ssap = LLCP_DEFAULT_SSAP;
+
+	// put a CONNECT PDU
+	headerBuf[0] = (LLCP_DEFAULT_DSAP << 2) + (PDU_CONNECT >> 2);
+	headerBuf[1] = ((PDU_CONNECT & 0x03) << 6) + LLCP_DEFAULT_SSAP;
+	if (!link.write(headerBuf, 2)) {
+		return -2;
+	}
+
+	// wait for a CC PDU
+	DMSG("wait for a CC PDU\n");
+	do {
+		if (2 > link.read(headerBuf, headerBufLen)) {
+			return -1;
+		}
+
+		type = getPType(headerBuf);
+		if (PDU_CC == type) {
+			break;
+		} else if (PDU_SYMM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return -2;
+			}
+		} else {
+			return -3;
+		}
+
+	} while (1);
+
+	if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+		return -2;
+	}
+
+	return 1;
+}
+
+int8_t LLCP::disconnect(uint16_t timeout)
+{
+	uint8_t type;
+
+	// try to get a SYMM PDU
+	if (2 > link.read(headerBuf, headerBufLen)) {
+		return -1;
+	}
+	type = getPType(headerBuf);
+	if (PDU_SYMM != type) {
+		return -1;
+	}
+
+	// put a DISC PDU
+	headerBuf[0] = (LLCP_DEFAULT_DSAP << 2) + (PDU_DISC >> 2);
+	headerBuf[1] = ((PDU_DISC & 0x03) << 6) + LLCP_DEFAULT_SSAP;
+	if (!link.write(headerBuf, 2)) {
+		return -2;
+	}
+
+	// wait for a DM PDU
+	DMSG("wait for a DM PDU\n");
+	do {
+		if (2 > link.read(headerBuf, headerBufLen)) {
+			return -1;
+		}
+
+		type = getPType(headerBuf);
+		if (PDU_CC == type) {
+			break;
+		} else if (PDU_DM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return -2;
+			}
+		} else {
+			return -3;
+		}
+
+	} while (1);
+
+	return 1;
+}
+
+bool LLCP::write(const uint8_t *header, uint8_t hlen, const uint8_t *body, uint8_t blen)
+{
+	uint8_t type;
+	uint8_t buf[3];
+
+	// Get a SYMM PDU
+	if (2 != link.read(buf, sizeof(buf))) {
+		return false;
+	}
+
+	if (headerBufLen < (hlen + 3)) {
+		return false;
+	}
+
+	for (int8_t i = hlen - 1; i >= 0; i--) {
+		headerBuf[i + 3] = header[i];
+	}
+
+	headerBuf[0] = (dsap << 2) + (PDU_I >> 2);
+	headerBuf[1] = ((PDU_I & 0x3) << 6) + ssap;
+	headerBuf[2] = (ns << 4) + nr;
+	if (!link.write(headerBuf, 3 + hlen, body, blen)) {
+		return false;
+	}
+
+	ns++;
+
+	// Get a RR PDU
+	int16_t status;
+	do {
+		status = link.read(headerBuf, headerBufLen);
+		if (2 > status) {
+			return false;
+		}
+
+		type = getPType(headerBuf);
+		if (PDU_RR == type) {
+			break;
+		} else if (PDU_SYMM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return false;
+			}
+		} else {
+			return false;
+		}
+	} while (1);
+
+	if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+		return false;
+	}
+
+	return true;
+}
+
+int16_t LLCP::read(uint8_t *buf, uint8_t length)
+{
+	uint8_t type;
+	uint16_t status;
+
+	// Get INFO PDU
+	do {
+		status = link.read(buf, length);
+		if (2 > status) {
+			return -1;
+		}
+
+		type = getPType(buf);
+		if (PDU_I == type) {
+			break;
+		} else if (PDU_SYMM == type) {
+			if (!link.write(SYMM_PDU, sizeof(SYMM_PDU))) {
+				return -2;
+			}
+		} else {
+			return -3;
+		}
+
+	} while (1);
+
+	uint8_t len = status - 3;
+	ssap = getDSAP(buf);
+	dsap = getSSAP(buf);
+
+	headerBuf[0] = (dsap << 2) + (PDU_RR >> 2);
+	headerBuf[1] = ((PDU_RR & 0x3) << 6) + ssap;
+	headerBuf[2] = (buf[2] >> 4) + 1;
+	if (!link.write(headerBuf, 3)) {
+		return -2;
+	}
+
+	for (uint8_t i = 0; i < len; i++) {
+		buf[i] = buf[i + 3];
+	}
+
+	nr++;
+
+	return len;
+}