From 805d738b24dfd0fbbdd301acfe7adbb5b0ff1e57 Mon Sep 17 00:00:00 2001
From: Romuald Conty <romuald@libnfc.org>
Date: Fri, 6 May 2011 15:03:08 +0000
Subject: [PATCH] Implement PN53x extended information frames with USB devices.
 (Fixes Issue 158)

---
 libnfc/drivers/arygon.c     |  2 +-
 libnfc/drivers/pn532_uart.c |  1 +
 libnfc/drivers/pn53x_usb.c  | 12 ++++++++++--
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/libnfc/drivers/arygon.c b/libnfc/drivers/arygon.c
index 8012966..a39d3bd 100644
--- a/libnfc/drivers/arygon.c
+++ b/libnfc/drivers/arygon.c
@@ -324,7 +324,7 @@ arygon_tama_receive (nfc_device_t * pnd, byte_t * pbtData, const size_t szDataLe
     return -1;
   } else if ((0xff == abtRxBuf[3]) && (0xff == abtRxBuf[4])) {
     // Extended frame
-    // FIXME: Code this
+    // ARYGON devices does not support extended frame sending
     abort ();
   } else {
     // Normal frame
diff --git a/libnfc/drivers/pn532_uart.c b/libnfc/drivers/pn532_uart.c
index f178202..29f6786 100644
--- a/libnfc/drivers/pn532_uart.c
+++ b/libnfc/drivers/pn532_uart.c
@@ -309,6 +309,7 @@ pn532_uart_receive (nfc_device_t * pnd, byte_t * pbtData, const size_t szDataLen
   } else if ((0xff == abtRxBuf[3]) && (0xff == abtRxBuf[4])) {
     // Extended frame
     pnd->iLastError = uart_receive (DRIVER_DATA(pnd)->port, abtRxBuf, 3, 0);
+    if (pnd->iLastError) return -1;
 
     // (abtRxBuf[0] << 8) + abtRxBuf[1] (LEN) include TFI + (CC+1)
     len = (abtRxBuf[0] << 8) + abtRxBuf[1] - 2;
diff --git a/libnfc/drivers/pn53x_usb.c b/libnfc/drivers/pn53x_usb.c
index 6bf4ccf..564f831 100644
--- a/libnfc/drivers/pn53x_usb.c
+++ b/libnfc/drivers/pn53x_usb.c
@@ -461,8 +461,16 @@ read:
     return -1;
   } else if ((0xff == abtRxBuf[offset]) && (0xff == abtRxBuf[offset + 1])) {
     // Extended frame
-    // FIXME: Code this
-    abort ();
+    offset += 2;
+
+    // (abtRxBuf[offset] << 8) + abtRxBuf[offset + 1] (LEN) include TFI + (CC+1)
+    len = (abtRxBuf[offset] << 8) + abtRxBuf[offset + 1] - 2;
+    if (((abtRxBuf[offset] + abtRxBuf[offset + 1] + abtRxBuf[offset + 2]) % 256) != 0) {
+      // TODO: Retry
+      ERR ("%s", "Length checksum mismatch");
+      pnd->iLastError = DEIO;
+      return -1;
+    }
     offset += 3;
   } else {
     // Normal frame