sniffer functionality fixed buffer

It is possible to use sniffer.py to sniff the phone-simcard-communication.

To be fixed: The buffer size read is fixed and the data is only send
over USB if the buffer max length is reached. which means we don not
get the last bytes of the transaction.
This should be changed in one of the next commits. Maybe the former
simtrace code can give some inspiration on this topic.

sam3s_example/simtrace/simtrace.h

@@ -1,6 +1,19 @@
 #ifndef SIMTRACE_H
 #define SIMTRACE_H
 
+/* Endpoint numbers */
+#define DATAOUT     1
+#define DATAIN      2
+#define INT         3
+
+#define BUFLEN  64
+typedef struct ring_buffer
+{
+    uint8_t     buf[BUFLEN*2];   // data buffer
+    uint8_t     idx;                // number of items in the buffer
+} ring_buffer;
+
+
 enum confNum {
     CFG_NUM_SNIFF = 1, CFG_NUM_PHONE, CFG_NUM_MITM, NUM_CONF
 };

sam3s_example/simtrace/simtrace_iso7816.c

@@ -38,11 +38,38 @@
 extern uint8_t rcvdChar;
 extern uint32_t char_stat;
 
+//#define BUFLEN  14
+// FIXME: Remove:
+#define PR TRACE_DEBUG
+//#define PR printf 
+
+/*typedef struct ring_buffer
+{
+    uint8_t     buf[BUFLEN*2];   // data buffer
+    uint8_t     idx;                // number of items in the buffer
+} ring_buffer;
+*/
+ring_buffer buf = { {0}, 0 };
+
+void buf_push(uint8_t item)
+{
+    buf.buf[buf.idx % (BUFLEN*2)] = item;
+    PR("----- Push: %x %x\n\r", buf.idx, buf.buf[buf.idx]);
+    buf.idx = (buf.idx+1) % (BUFLEN*2);
+}
+
+uint8_t get_buf_start(uint8_t *buf_start)
+{
+    *buf_start = &(buf.buf[buf.idx]);
+    return 2*BUFLEN-buf.idx;
+}
+
 /** Initializes a ISO driver
  */ 
 // FIXME: This function is implemented in iso7816_4.c !! Only MCK instead of SCK is always taken. Change that!                                                                               
 void _ISO7816_Init( void )
 {   
+    printf("ISO_Init\n\r");
     TRACE_DEBUG("ISO_Init\n\r");
                         
     USART_Configure( USART_PHONE,                                                          
@@ -98,20 +125,29 @@ void USART1_IrqHandler( void )
 */  
     uint32_t csr = USART_PHONE->US_CSR;                                                       
     
+    PR("---- stat: %x\n\r", csr);
+
     if (csr & US_CSR_TXRDY) {
         /* transmit buffer empty, nothing to transmit */                                      
     }  
     if (csr & US_CSR_RXRDY) {
         stat = (csr&(US_CSR_OVRE|US_CSR_FRAME|
-                        US_CSR_PARE|US_CSR_TIMEOUT|US_CSR_NACK|                               
+                        US_CSR_PARE|US_CSR_TIMEOUT|US_CSR_NACK|
-                        (1<<10)));                                                            
+                        (1<<10)));
-        
+
         if (stat == 0 ) {
-            /* Get a char */
+            /* Fill char into buffer */
-            rcvdChar = ((USART_PHONE->US_RHR) & 0xFF);                                        
+            PR("---- BUFLEN %x\n\r", buf.idx);
-        } /* else: error occured */                                                           
+            buf_push((USART_PHONE->US_RHR) & 0xFF);
-        char_stat = stat;                                                                     
+        } else {
-    }                                                                                         
+       //     buf_push((USART_PHONE->US_RHR) & 0xFF);
-}                                                                                             
+            PR("%x\n\r", (USART_PHONE->US_RHR) & 0xFF);
+        } /* else: error occured */
 
+        if ((buf.idx % BUFLEN) == 0) {
+            rcvdChar = 1;
+        }
 
+        char_stat = stat;
+    }
+}

sam3s_example/simtrace/sniffer.c

@@ -38,6 +38,8 @@
 /*------------------------------------------------------------------------------
  *         Internal definitions
  *------------------------------------------------------------------------------*/
+// FIXME: Remove:
+#define PR TRACE_DEBUG
 
 /** Maximum ucSize in bytes of the smartcard answer to a command.*/
 #define MAX_ANSWER_SIZE         10
@@ -60,6 +62,7 @@ static const Pin pPwr[] = {
 
 extern uint32_t char_stat;
 extern uint8_t rcvdChar;
+extern ring_buffer buf;
 
 /*-----------------------------------------------------------------------------
  *          Initialization routine
@@ -80,8 +83,16 @@ void Sniffer_Init( void )
 
 void Sniffer_run( void )
 {
+    uint8_t c = 0;
+    c++;
+
     if (rcvdChar != 0) {
-        TRACE_DEBUG("Rcvd char _%x_ \n\r", rcvdChar);
+        /*  DATA_IN for host side is data_out for simtrace side   */
+        /* FIXME: Performancewise sending a USB packet for every byte is a disaster */
+        PR("----- %x %x %x ..\n\r", buf.buf[0], buf.buf[1],buf.buf[2] );
+        USBD_Write( DATAIN, buf.buf, BUFLEN, 0, 0 );
+//        USBD_Write( DATAIN, &c, 1, 0, 0 );
+        PR("----- Rcvd char\n\r");
         rcvdChar = 0;
     }
 }

sam3s_example/simtrace/usb.c

@@ -154,11 +154,6 @@ const unsigned char *stringDescriptors[] = {
     MITMConfigStringDescriptor
 };
 
-/* Endpoint numbers */
-#define DATAOUT     1
-#define DATAIN      2
-#define INT         3
-
 /*------------------------------------------------------------------------------
  *       USB Device descriptors 
  *------------------------------------------------------------------------------*/