From 2ca42cc155a68f1e700a2c123e3706c82b6f9aaa Mon Sep 17 00:00:00 2001
From: Austin Abell <austinabell8@gmail.com>
Date: Wed, 18 Sep 2019 16:14:39 -0400
Subject: [PATCH] Implement eth_sendRawTransaction (#101)

* Implement sendRawTransaction (tx not being broadcasted to node from server)

* Add broadcast type flag to rpc API and fixed amount validation

* Add documentation
---
 rpc/config.go      |  3 ++-
 rpc/eth_api.go     | 30 +++++++++++++++++++++++++++---
 x/evm/types/msg.go |  3 ++-
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/rpc/config.go b/rpc/config.go
index 790b1a5d..72afbae1 100644
--- a/rpc/config.go
+++ b/rpc/config.go
@@ -3,6 +3,7 @@ package rpc
 import (
 	"fmt"
 
+	"github.com/cosmos/cosmos-sdk/client/flags"
 	"github.com/cosmos/cosmos-sdk/client/lcd"
 	"github.com/cosmos/cosmos-sdk/codec"
 	emintcrypto "github.com/cosmos/ethermint/crypto"
@@ -35,8 +36,8 @@ type Config struct {
 // Web3RpcCmd creates a CLI command to start RPC server
 func Web3RpcCmd(cdc *codec.Codec) *cobra.Command {
 	cmd := lcd.ServeCommand(cdc, registerRoutes)
-	// Attach flag to cmd output to be handled in registerRoutes
 	cmd.Flags().String(flagUnlockKey, "", "Select a key to unlock on the RPC server")
+	cmd.Flags().StringP(flags.FlagBroadcastMode, "b", flags.BroadcastSync, "Transaction broadcasting mode (sync|async|block)")
 	return cmd
 }
 
diff --git a/rpc/eth_api.go b/rpc/eth_api.go
index f01997a5..4acc00e2 100644
--- a/rpc/eth_api.go
+++ b/rpc/eth_api.go
@@ -6,6 +6,7 @@ import (
 	"math/big"
 
 	"github.com/cosmos/cosmos-sdk/client/context"
+	authutils "github.com/cosmos/cosmos-sdk/x/auth/client/utils"
 	emintcrypto "github.com/cosmos/ethermint/crypto"
 	emintkeys "github.com/cosmos/ethermint/keys"
 	"github.com/cosmos/ethermint/version"
@@ -14,6 +15,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/ethereum/go-ethereum/signer/core"
 )
@@ -204,9 +206,31 @@ func (e *PublicEthAPI) SendTransaction(args core.SendTxArgs) common.Hash {
 }
 
 // SendRawTransaction send a raw Ethereum transaction.
-func (e *PublicEthAPI) SendRawTransaction(data hexutil.Bytes) common.Hash {
-	var h common.Hash
-	return h
+func (e *PublicEthAPI) SendRawTransaction(data hexutil.Bytes) (common.Hash, error) {
+	tx := new(types.EthereumTxMsg)
+
+	// RLP decode raw transaction bytes
+	if err := rlp.DecodeBytes(data, tx); err != nil {
+		// Return nil is for when gasLimit overflows uint64
+		return common.Hash{}, nil
+	}
+
+	// Encode transaction by default Tx encoder
+	txEncoder := authutils.GetTxEncoder(e.cliCtx.Codec)
+	txBytes, err := txEncoder(tx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	// TODO: Possibly log the contract creation address (if recipient address is nil) or tx data
+	res, err := e.cliCtx.BroadcastTx(txBytes)
+	// If error is encountered on the node, the broadcast will not return an error
+	fmt.Println(res.RawLog)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	return common.HexToHash(res.TxHash), nil
 }
 
 // CallArgs represents arguments to a smart contract call as provided by RPC clients.
diff --git a/x/evm/types/msg.go b/x/evm/types/msg.go
index b2383102..b9ecd9a3 100644
--- a/x/evm/types/msg.go
+++ b/x/evm/types/msg.go
@@ -131,7 +131,8 @@ func (msg EthereumTxMsg) ValidateBasic() sdk.Error {
 		return types.ErrInvalidValue(fmt.Sprintf("Price must be positive: %x", msg.Data.Price))
 	}
 
-	if msg.Data.Amount.Sign() != 1 {
+	// Amount can be 0
+	if msg.Data.Amount.Sign() == -1 {
 		return types.ErrInvalidValue(fmt.Sprintf("amount must be positive: %x", msg.Data.Amount))
 	}