internal/ethapi: reject non-replay-protected txs over RPC (#22339)

This PR prevents users from submitting transactions without EIP-155 enabled. This behaviour can be overridden by specifying the flag --rpc.allow-unprotected-txs=true.

eth/api_backend.go

@@ -41,9 +41,10 @@ import (
 
 // EthAPIBackend implements ethapi.Backend for full nodes
 type EthAPIBackend struct {
-	extRPCEnabled bool
-	eth           *Ethereum
-	gpo           *gasprice.Oracle
+	extRPCEnabled       bool
+	allowUnprotectedTxs bool
+	eth                 *Ethereum
+	gpo                 *gasprice.Oracle
 }
 
 // ChainConfig returns the active chain configuration.
@@ -292,6 +293,10 @@ func (b *EthAPIBackend) ExtRPCEnabled() bool {
 	return b.extRPCEnabled
 }
 
+func (b *EthAPIBackend) UnprotectedAllowed() bool {
+	return b.allowUnprotectedTxs
+}
+
 func (b *EthAPIBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }