Add --skip to hw tearoff, to cope with more complex commands. Example provided for hf mfu wrbl

Author: doegox

armsrc/appmain.c

@@ -94,6 +94,7 @@ static int button_status = BUTTON_NO_CLICK;
 static bool allow_send_wtx = false;
 uint16_t g_tearoff_delay_us = 0;
 bool g_tearoff_enabled = false;
+uint8_t g_tearoff_skip = 0;
 
 int tearoff_hook(void) {
     if (g_tearoff_enabled) {
@@ -102,6 +103,11 @@ int tearoff_hook(void) {
             g_tearoff_enabled = false;
             return PM3_SUCCESS; // SUCCESS = the hook didn't do anything
         }
+        if (g_tearoff_skip > 0) {
+            Dbprintf(_GREEN_("Tear-off skipped!"));
+            g_tearoff_skip--;
+            return PM3_SUCCESS; // SUCCESS = the hook didn't do anything
+        }
         SpinDelayUsPrecision(g_tearoff_delay_us);
         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
         g_tearoff_enabled = false;
@@ -882,12 +888,7 @@ static void PacketReceived(PacketCommandNG *packet) {
             break;
         }
         case CMD_SET_TEAROFF: {
-            struct p {
-                uint16_t delay_us;
-                bool on;
-                bool off;
-            } PACKED;
-            struct p *payload = (struct p *)packet->data.asBytes;
+            tearoff_params_t *payload = (tearoff_params_t *)packet->data.asBytes;
             if (payload->on && payload->off) {
                 reply_ng(CMD_SET_TEAROFF, PM3_EINVARG, NULL, 0);
             }
@@ -903,6 +904,10 @@ static void PacketReceived(PacketCommandNG *packet) {
             if (payload->delay_us > 0) {
                 g_tearoff_delay_us = payload->delay_us;
             }
+
+            if (payload->skip > -1) {
+                g_tearoff_skip = payload->skip;
+            }
             reply_ng(CMD_SET_TEAROFF, PM3_SUCCESS, NULL, 0);
             break;
         }

armsrc/mifareutil.c

@@ -87,6 +87,9 @@ uint16_t mifare_sendcmd(uint8_t cmd, uint8_t *data, uint8_t data_size, uint8_t *
 
     AddCrc14A(dcmd, data_size + 1);
     ReaderTransmit(dcmd, sizeof(dcmd), timing);
+    if (tearoff_hook() == PM3_ETEAROFF) { // tearoff occurred
+        return 0;
+    }
     uint16_t len = ReaderReceive(answer, answer_len, answer_parity);
     if (len == 0) {
         if (g_dbglevel >= DBG_ERROR) Dbprintf("%02X Cmd failed. Card timeout.", cmd);
@@ -114,6 +117,9 @@ uint16_t mifare_sendcmd_short(struct Crypto1State *pcs, uint8_t crypted, uint8_t
     } else {
         ReaderTransmit(dcmd, sizeof(dcmd), timing);
     }
+    if (tearoff_hook() == PM3_ETEAROFF) { // tearoff occurred
+        return 0;
+    }
 
     uint16_t len = ReaderReceive(answer, answer_len, par);
 

client/src/cmdhw.c

@@ -1174,6 +1174,11 @@ int handle_tearoff(tearoff_params_t *params, bool verbose) {
         if (params->delay_us > 0 && verbose)
             PrintAndLogEx(INFO, "Tear-off hook configured with delay of " _GREEN_("%i us"), params->delay_us);
 
+        if (params->skip > 0 && verbose)
+            PrintAndLogEx(INFO, "Tear-off hook will be skipped " _YELLOW_("%i times") " before being activated", params->skip);
+        if (params->skip == 0 && verbose)
+            PrintAndLogEx(INFO, "Tear-off hook skipping " _GREEN_("disabled"));
+
         if (params->on && verbose)
             PrintAndLogEx(INFO, "Tear-off hook " _GREEN_("enabled"));
 
@@ -1201,6 +1206,7 @@ static int CmdTearoff(const char *Cmd) {
         arg_int0(NULL, "delay", "<dec>", "Delay in us before triggering tear-off, must be between 1 and 43000"),
         arg_lit0(NULL, "on", "Activate tear-off hook"),
         arg_lit0(NULL, "off", "Deactivate tear-off hook"),
+        arg_int0(NULL, "skip", "<dec>", "Skip N triggers before activating the hook"),
         arg_lit0("s", "silent", "less verbose output"),
         arg_lit0(NULL, "list", "List commands implementing tear-off hooks"),
         arg_param_end
@@ -1211,8 +1217,9 @@ static int CmdTearoff(const char *Cmd) {
     int delay = arg_get_int_def(ctx, 1, -1);
     params.on = arg_get_lit(ctx, 2);
     params.off = arg_get_lit(ctx, 3);
-    bool silent = arg_get_lit(ctx, 4);
-    bool list = arg_get_lit(ctx, 5);
+    int skip = arg_get_int_def(ctx, 4, -1);
+    bool silent = arg_get_lit(ctx, 5);
+    bool list = arg_get_lit(ctx, 6);
     CLIParserFree(ctx);
 
     if (list) {
@@ -1223,8 +1230,8 @@ static int CmdTearoff(const char *Cmd) {
         PrintAndLogEx(INFO, "  hf 15 raw");
         PrintAndLogEx(INFO, "  hf iclass creditepurse");
         PrintAndLogEx(INFO, "  hf iclass wrbl");
-        PrintAndLogEx(INFO, "  hf mfc wrbl");
-        // PrintAndLogEx(INFO, "  hf mfu wrbl");
+        PrintAndLogEx(INFO, "  hf mf wrbl");
+        PrintAndLogEx(INFO, "  hf mfu wrbl (with --skip 3)");
         PrintAndLogEx(INFO, "  hf topaz wrbl");
         PrintAndLogEx(INFO, "  lf em 4x05 write");
         PrintAndLogEx(INFO, "  lf em 4x50 wrbl");
@@ -1251,6 +1258,16 @@ static int CmdTearoff(const char *Cmd) {
     }
 
     params.delay_us = delay;
+
+    if (skip != -1) {
+        if ((skip < 0) || (skip > 127)) {
+            PrintAndLogEx(WARNING, "You can't set skip out of 0..127 range!");
+            return PM3_EINVARG;
+        }
+    }
+
+    params.skip = skip;
+
     if (params.on && params.off) {
         PrintAndLogEx(WARNING, "You can't set both --on and --off!");
         return PM3_EINVARG;

include/pm3_cmd.h

@@ -371,6 +371,7 @@ typedef struct {
 
 typedef struct {
     uint16_t delay_us;
+    int8_t skip;
     bool on;
     bool off;
 } PACKED tearoff_params_t;