]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/lfops.c
Coverity-fixes in armsrc
[proxmark3-svn] / armsrc / lfops.c
index d29ec37551658effd1ee580d36f1e4932df95f49..7d497e3cc42c411ed83a02d9d59aa106fc90d4a4 100644 (file)
 #include "crc16.h"
 #include "string.h"
 
-// split into two routines so we can avoid timing issues after sending commands //
+
+/**
+* Does the sample acquisition. If threshold is specified, the actual sampling 
+* is not commenced until the threshold has been reached. 
+* @param trigger_threshold - the threshold
+* @param silent - is true, now outputs are made. If false, dbprints the status
+*/
 void DoAcquisition125k_internal(int trigger_threshold,bool silent)
 {
        uint8_t *dest = (uint8_t *)BigBuf;
@@ -46,12 +52,21 @@ void DoAcquisition125k_internal(int trigger_threshold,bool silent)
                
        }
 }
+/**
+* Perform sample aquisition. 
+*/
 void DoAcquisition125k(int trigger_threshold)
 {
        DoAcquisition125k_internal(trigger_threshold, false);
 }
 
-//void SetupToAcquireRawAdcSamples(int divisor)
+/**
+* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream 
+* if not already loaded, sets divisor and starts up the antenna. 
+* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
+*                                 0 or 95 ==> 125 KHz
+*                                 
+**/
 void LFSetupFPGAForADC(int divisor, bool lf_field)
 {
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
@@ -71,46 +86,46 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
        // Now set up the SSC to get the ADC samples that are now streaming at us.
        FpgaSetupSsc();
 }
-
+/**
+* Initializes the FPGA, and acquires the samples. 
+**/
 void AcquireRawAdcSamples125k(int divisor)
 {
        LFSetupFPGAForADC(divisor, true);
        // Now call the acquisition routine
        DoAcquisition125k_internal(-1,false);
 }
+/**
+* Initializes the FPGA for snoop-mode, and acquires the samples. 
+**/
+
 void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
 {
        LFSetupFPGAForADC(divisor, false);
-       DoAcquisition125k(trigger_threshold, false);
-}
-
-
+       DoAcquisition125k(trigger_threshold);
 }
 
 void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)
 {
-       int at134khz;
 
        /* Make sure the tag is reset */
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        SpinDelay(2500);
 
+
+       int divisor_used = 95; // 125 KHz
        // see if 'h' was specified
+
        if (command[strlen((char *) command) - 1] == 'h')
-               at134khz = TRUE;
-       else
-               at134khz = FALSE;
+               divisor_used = 88; // 134.8 KHz
 
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
-
        // Give it a bit of time for the resonant antenna to settle.
        SpinDelay(50);
+
        // And a little more time for the tag to fully power up
        SpinDelay(2000);
 
@@ -122,10 +137,7 @@ void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1,
                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
                LED_D_OFF();
                SpinDelayUs(delay_off);
-               if (at134khz)
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-               else
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 
 
                FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
                LED_D_ON();
@@ -137,10 +149,7 @@ void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1,
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LED_D_OFF();
        SpinDelayUs(delay_off);
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 
@@ -702,21 +711,19 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
        size_t size=0,idx=0; //, found=0;
        uint32_t hi2=0, hi=0, lo=0;
 
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
 
        while(!BUTTON_PRESS()) {
 
-               // Configure to go in 125Khz listen mode
-               LFSetupFPGAForADC(0, true)
-
                WDT_HIT();
                if (ledcontrol) LED_A_ON();
 
-               DoAcquisition125k_internal(true);
+               DoAcquisition125k_internal(-1,true);
                size  = sizeof(BigBuf);
 
                // FSK demodulator
                size = fsk_demod(dest, size);
-               WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
                // 1->0 : fc/8 in sets of 6
@@ -737,7 +744,8 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
                                idx+=sizeof(frame_marker_mask);
 
                                while(dest[idx] != dest[idx+1] && idx < size-2)
-                               {       // Keep going until next frame marker (or error)
+                               {       
+                                       // Keep going until next frame marker (or error)
                                        // Shift in a bit. Start by shifting high registers
                                        hi2 = (hi2<<1)|(hi>>31);
                                        hi = (hi<<1)|(lo>>31);
@@ -752,16 +760,20 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
                                }
                                //Dbprintf("Num shifts: %d ", numshifts);
                                // Hopefully, we read a tag and  hit upon the next frame marker
-                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
+                               if(idx + sizeof(frame_marker_mask) < size)
                                {
-                                       if (hi2 != 0){
-                                               Dbprintf("TAG ID: %x%08x%08x (%d)",
-                                                        (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-                                       }
-                                       else {
-                                               Dbprintf("TAG ID: %x%08x (%d)",
-                                                (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                                       if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
+                                       {
+                                               if (hi2 != 0){
+                                                       Dbprintf("TAG ID: %x%08x%08x (%d)",
+                                                                (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                                               }
+                                               else {
+                                                       Dbprintf("TAG ID: %x%08x (%d)",
+                                                        (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                                               }
                                        }
+
                                }
 
                                // reset
@@ -798,21 +810,20 @@ void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
        size_t size=0, idx=0;
        uint32_t code=0, code2=0;
 
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
 
        while(!BUTTON_PRESS()) {
 
-               // Configure to go in 125Khz listen mode
-               LFSetupFPGAForADC(0, true);
 
                WDT_HIT();
                if (ledcontrol) LED_A_ON();
 
-               DoAcquisition125k_internal(true);
+               DoAcquisition125k_internal(-1,true);
                size  = sizeof(BigBuf);
 
                // FSK demodulator
                size = fsk_demod(dest, size);
-               WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
                // 1->0 : fc/8 in sets of 7
@@ -1445,78 +1456,81 @@ int DemodPCF7931(uint8_t **outBlocks) {
        
        for (bitidx = 0; i < GraphTraceLen; i++)
        {
-    if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
-    {
-      lc = i - lastval;
-      lastval = i;
-      
-      // Switch depending on lc length:
-      // Tolerance is 1/8 of clock rate (arbitrary)
-      if (abs(lc-clock/4) < tolerance) {
-        // 16T0
-        if((i - pmc) == lc) { /* 16T0 was previous one */
-          /* It's a PMC ! */
-          i += (128+127+16+32+33+16)-1;
-          lastval = i;
-          pmc = 0;
-          block_done = 1;
-        }
-        else {
-          pmc = i;
-        }
-      } else if (abs(lc-clock/2) < tolerance) {
-        // 32TO
-        if((i - pmc) == lc) { /* 16T0 was previous one */
-          /* It's a PMC ! */
-          i += (128+127+16+32+33)-1;
-          lastval = i;
-          pmc = 0;
-          block_done = 1;
-        }
-        else if(half_switch == 1) {
-          BitStream[bitidx++] = 0;
-          half_switch = 0;
-        }
-        else
-          half_switch++;
-      } else if (abs(lc-clock) < tolerance) {
-        // 64TO
-        BitStream[bitidx++] = 1;
-      } else {
-        // Error
-        warnings++;
-        if (warnings > 10)
-        {
-          Dbprintf("Error: too many detection errors, aborting.");
-          return 0;
-        }
-      }
-      
-      if(block_done == 1) {
-        if(bitidx == 128) {
-          for(j=0; j<16; j++) {
-            Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
-            64*BitStream[j*8+6]+
-            32*BitStream[j*8+5]+
-            16*BitStream[j*8+4]+
-            8*BitStream[j*8+3]+
-            4*BitStream[j*8+2]+
-            2*BitStream[j*8+1]+
-            BitStream[j*8];
-          }
-          num_blocks++;
-        }
-        bitidx = 0;
-        block_done = 0;
-        half_switch = 0;
-      }
-      if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
-      else dir = 1;
-    }
-    if(bitidx==255)
-      bitidx=0;
-    warnings = 0;
-    if(num_blocks == 4) break;
+           if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
+           {
+             lc = i - lastval;
+             lastval = i;
+             
+             // Switch depending on lc length:
+             // Tolerance is 1/8 of clock rate (arbitrary)
+             if (abs(lc-clock/4) < tolerance) {
+               // 16T0
+               if((i - pmc) == lc) { /* 16T0 was previous one */
+                 /* It's a PMC ! */
+                 i += (128+127+16+32+33+16)-1;
+                 lastval = i;
+                 pmc = 0;
+                 block_done = 1;
+               }
+               else {
+                 pmc = i;
+               }
+             } else if (abs(lc-clock/2) < tolerance) {
+               // 32TO
+               if((i - pmc) == lc) { /* 16T0 was previous one */
+                 /* It's a PMC ! */
+                 i += (128+127+16+32+33)-1;
+                 lastval = i;
+                 pmc = 0;
+                 block_done = 1;
+               }
+               else if(half_switch == 1) {
+                 BitStream[bitidx++] = 0;
+                 half_switch = 0;
+               }
+               else
+                 half_switch++;
+             } else if (abs(lc-clock) < tolerance) {
+               // 64TO
+               BitStream[bitidx++] = 1;
+             } else {
+               // Error
+               warnings++;
+               if (warnings > 10)
+               {
+                 Dbprintf("Error: too many detection errors, aborting.");
+                 return 0;
+               }
+             }
+             
+             if(block_done == 1) {
+               if(bitidx == 128) {
+                 for(j=0; j<16; j++) {
+                   Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
+                   64*BitStream[j*8+6]+
+                   32*BitStream[j*8+5]+
+                   16*BitStream[j*8+4]+
+                   8*BitStream[j*8+3]+
+                   4*BitStream[j*8+2]+
+                   2*BitStream[j*8+1]+
+                   BitStream[j*8];
+                 }
+                 num_blocks++;
+               }
+               bitidx = 0;
+               block_done = 0;
+               half_switch = 0;
+             }
+             if(i < GraphTraceLen)
+             {
+                     if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
+                     else dir = 1;             
+             }
+           }
+           if(bitidx==255)
+             bitidx=0;
+           warnings = 0;
+           if(num_blocks == 4) break;
        }
        memcpy(outBlocks, Blocks, 16*num_blocks);
        return num_blocks;
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