Merge pull request #1715 from merlokk/hf_sniff_skipping

`hf sniff`. skip some bytes from data to get long data to the buffer

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Added `hf sniff --smode` skip/group adc data to consume less memory. Now it can sniff very long signals (@merlokk)
  - Added `hf fudan` skeleton commands (@iceman1001)
  - Added `--reboot-to-bootloader` arg to pm3
  - Changed `hf 14b raw` - now supports selecting Fuji/Xerox tag (@horror)

armsrc/appmain.c

@@ -1784,11 +1784,13 @@ static void PacketReceived(PacketCommandNG *packet) {
             struct p {
                 uint32_t samplesToSkip;
                 uint32_t triggersToSkip;
+                uint8_t skipMode;
+                uint8_t skipRatio;
             } PACKED;
             struct p *payload = (struct p *)packet->data.asBytes;
 
             uint16_t len = 0;
-            int res = HfSniff(payload->samplesToSkip, payload->triggersToSkip, &len);
+            int res = HfSniff(payload->samplesToSkip, payload->triggersToSkip, &len, payload->skipMode, payload->skipRatio);
 
             struct {
                 uint16_t len;

armsrc/hfsnoop.c

@@ -36,7 +36,56 @@ static void RAMFUNC optimizedSniff(uint16_t *dest, uint16_t dsize) {
     }
 }
 
-int HfSniff(uint32_t samplesToSkip, uint32_t triggersToSkip, uint16_t *len) {
+static void RAMFUNC skipSniff(uint8_t *dest, uint16_t dsize, uint8_t skipMode, uint8_t skipRatio) {
+    uint32_t accum = (skipMode == HF_SNOOP_SKIP_MIN) ? 0xffffffff : 0;
+    uint8_t ratioindx = 0;
+    while (dsize > 0) {
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            volatile uint16_t val = (uint16_t)(AT91C_BASE_SSC->SSC_RHR);
+            switch (skipMode) {
+                case HF_SNOOP_SKIP_MAX:
+                    if (accum < (val & 0xff))
+                        accum = val & 0xff;
+                    if (accum < (val >> 8))
+                        accum = val >> 8;
+                    break;
+                case HF_SNOOP_SKIP_MIN:
+                    if (accum > (val & 0xff))
+                        accum = val & 0xff;
+                    if (accum > (val >> 8))
+                        accum = val >> 8;
+                    break;
+                case HF_SNOOP_SKIP_AVG:
+                    accum += (val & 0xff) + (val & 0xff);
+                    break;
+                default: { // HF_SNOOP_SKIP_DROP and the rest 
+                    if (ratioindx == 0)
+                        accum = val & 0xff;
+                }
+            }
+
+            ratioindx++;
+            if (ratioindx >= skipRatio) {
+                if (skipMode == HF_SNOOP_SKIP_AVG && skipRatio > 0) {
+                    accum = accum / (skipRatio * 2);
+                    if (accum <= 0xff)
+                        *dest = accum;
+                    else
+                        *dest = 0xff;
+                } else {
+                    *dest = accum;
+                }
+
+                dest++;
+                dsize --;
+                accum = (skipMode == HF_SNOOP_SKIP_MIN) ? 0xffffffff : 0;
+                ratioindx = 0;
+            }
+        }
+    }
+}
+
+int HfSniff(uint32_t samplesToSkip, uint32_t triggersToSkip, uint16_t *len, uint8_t skipMode, uint8_t skipRatio) {
     BigBuf_free();
     BigBuf_Clear_ext(false);
 
@@ -105,7 +154,10 @@ int HfSniff(uint32_t samplesToSkip, uint32_t triggersToSkip, uint16_t *len) {
             }
         }
 
+        if (skipMode == 0)
             optimizedSniff((uint16_t *)mem, *len);
+        else
+            skipSniff(mem, *len, skipMode, skipRatio);
 
         if (g_dbglevel >= DBG_INFO) {
             Dbprintf("Trigger kicked in (%d >= 180)", r);

armsrc/hfsnoop.h

@@ -18,6 +18,13 @@
 
 #include "proxmark3_arm.h"
 
-int HfSniff(uint32_t samplesToSkip, uint32_t triggersToSkip, uint16_t *len);
+// what to do with skipped data
+#define HF_SNOOP_SKIP_NONE (0)
+#define HF_SNOOP_SKIP_DROP (1)
+#define HF_SNOOP_SKIP_MAX  (2)
+#define HF_SNOOP_SKIP_MIN  (3)
+#define HF_SNOOP_SKIP_AVG  (4)
+
+int HfSniff(uint32_t samplesToSkip, uint32_t triggersToSkip, uint16_t *len, uint8_t skipMode, uint8_t skipRatio);
 void HfPlotDownload(void);
 #endif

client/src/cmdhf.c

@@ -301,6 +301,23 @@ int CmdHFTune(const char *Cmd) {
     return PM3_SUCCESS;
 }
 
+typedef enum {
+    HF_SNOOP_SKIP_NONE = 0x00,
+    HF_SNOOP_SKIP_DROP = 0x01, 
+    HF_SNOOP_SKIP_MAX = 0x02,
+    HF_SNOOP_SKIP_MIN = 0x03,
+    HF_SNOOP_SKIP_AVG = 0x04
+} HFSnoopSkipMode;
+
+const CLIParserOption HFSnoopSkipModeOpts[] = {
+    {HF_SNOOP_SKIP_NONE, "none"},
+    {HF_SNOOP_SKIP_DROP, "drop"},
+    {HF_SNOOP_SKIP_MAX,  "min"},
+    {HF_SNOOP_SKIP_MIN,  "max"},
+    {HF_SNOOP_SKIP_AVG,  "avg"},
+    {0,    NULL},
+};
+
 // Collects pars of u8,
 // uses 16bit transfers from FPGA for speed
 // Takes all available bigbuff memory
@@ -319,6 +336,8 @@ int CmdHFSniff(const char *Cmd) {
         arg_param_begin,
         arg_u64_0(NULL, "sp",    "<dec>", "skip sample pairs"),
         arg_u64_0(NULL, "st",    "<dec>", "skip number of triggers"),
+        arg_str0(NULL,  "smode", "[none|drop|min|max|avg]", "Skip mode. It switches on the function that applies to several samples before they saved to memory"),
+        arg_int0(NULL,  "sratio",  "<dec, ms>", "Skip ratio. It applied the function above to (ratio * 2) samples. For ratio = 1 it 2 samples."),
         arg_param_end
     };
     CLIExecWithReturn(ctx, Cmd, argtable, true);
@@ -326,12 +345,26 @@ int CmdHFSniff(const char *Cmd) {
     struct {
         uint32_t samplesToSkip;
         uint32_t triggersToSkip;
+        uint8_t skipMode;
+        uint8_t skipRatio;
     } PACKED params;
 
     params.samplesToSkip = arg_get_u32_def(ctx, 1, 0);
     params.triggersToSkip = arg_get_u32_def(ctx, 2, 0);
+    int smode = 0;
+    if (CLIGetOptionList(arg_get_str(ctx, 3), HFSnoopSkipModeOpts, &smode))
+        return PM3_EINVARG;
+
+    if (smode > 0)
+        params.skipMode = smode;
+
+    params.skipRatio = arg_get_int_def(ctx, 4, 0);
     CLIParserFree(ctx);
 
+    if (params.skipMode != HF_SNOOP_SKIP_NONE)
+        PrintAndLogEx(INFO, "Skip mode. Function: %s, each: %d sample", 
+            CLIGetOptionListStr(HFSnoopSkipModeOpts, params.skipMode), params.skipRatio * 2);
+
     clearCommandBuffer();
     SendCommandNG(CMD_HF_SNIFF, (uint8_t *)&params, sizeof(params));