From a5d8d0b57ad3236595f17d22130d84ae0950fc73 Mon Sep 17 00:00:00 2001
From: justinbastress <33579608+justinbastress@users.noreply.github.com>
Date: Tue, 19 Dec 2017 16:21:16 -0500
Subject: [PATCH] remove unnecessary indirection on net.Conn (#27)

---
 lib/mysql/mysql.go | 18 ++++++++----------
 modules/mysql.go   | 14 +-------------
 tls.go             |  4 ++--
 3 files changed, 11 insertions(+), 25 deletions(-)

diff --git a/lib/mysql/mysql.go b/lib/mysql/mysql.go
index 2faaa12..e3e68c0 100644
--- a/lib/mysql/mysql.go
+++ b/lib/mysql/mysql.go
@@ -220,7 +220,7 @@ type Connection struct {
 	// Enum to track connection status
 	State ConnectionState
 	// TCP or TLS-wrapped Connection pointer (IsSecure() will tell which)
-	Connection *net.Conn
+	Connection net.Conn
 	// The sequence number used with the server to number packets
 	SequenceNumber uint8
 
@@ -540,7 +540,7 @@ func (c *Connection) sendPacket(packet WritablePacket) (*ConnectionLogEntry, err
 	}
 
 	// @TODO: Buffered send?
-	_, err := (*c.Connection).Write(toSend)
+	_, err := c.Connection.Write(toSend)
 	return &logPacket, err
 }
 
@@ -564,9 +564,8 @@ func (c *Connection) decodePacket(body []byte) (PacketInfo, error) {
 // Read a packet and sequence identifier off of the given connection
 func (c *Connection) readPacket() (*ConnectionLogEntry, error) {
 	// @TODO @FIXME Find/use conventional buffered packet-reading functions, handle timeouts / connection reset / etc
-	conn := *c.Connection
-	reader := bufio.NewReader(conn)
-	if terr := conn.SetReadDeadline(time.Now().Add(c.Config.Timeout)); terr != nil {
+	reader := bufio.NewReader(c.Connection)
+	if terr := c.Connection.SetReadDeadline(time.Now().Add(c.Config.Timeout)); terr != nil {
 		return nil, fmt.Errorf("Error calling SetReadTimeout(): %s", terr)
 	}
 	var header [4]byte
@@ -618,13 +617,12 @@ func (c *Connection) GetHandshake() *HandshakePacket {
 
 // Perform a TLS handshake using the configured TLSConfig on the current connection
 func (c *Connection) StartTLS() error {
-
-	client := tls.Client(*c.Connection, c.Config.TLSConfig)
+	client := tls.Client(c.Connection, c.Config.TLSConfig)
 	err := client.Handshake()
 	if err != nil {
 		return fmt.Errorf("TLS Handshake error: %s", err)
 	}
-	*(c.Connection) = client
+	c.Connection = client
 	return nil
 }
 
@@ -666,7 +664,7 @@ func (c *Connection) Connect() error {
 		log.Debugf("Error connecting: %v", err)
 		return fmt.Errorf("Connect error: %s", err)
 	}
-	c.Connection = &conn
+	c.Connection = conn
 	c.State = STATE_CONNECTED
 	c.ConnectionLog = ConnectionLog{
 		Handshake:  nil,
@@ -706,7 +704,7 @@ func (c *Connection) Disconnect() error {
 	}
 	c.State = STATE_NOT_CONNECTED
 	// Change state even if close fails
-	return (*c.Connection).Close()
+	return c.Connection.Close()
 }
 
 // NUL STRING type from https://web.archive.org/web/20160316113745/https://dev.mysql.com/doc/internals/en/string.html
diff --git a/modules/mysql.go b/modules/mysql.go
index 03d66f4..16a6809 100644
--- a/modules/mysql.go
+++ b/modules/mysql.go
@@ -1,8 +1,6 @@
 package modules
 
 import (
-	"net"
-
 	log "github.com/sirupsen/logrus"
 	"github.com/zmap/zgrab2"
 	"github.com/zmap/zgrab2/lib/mysql"
@@ -104,17 +102,7 @@ func (s *MySQLScanner) Scan(t zgrab2.ScanTarget) (status zgrab2.ScanStatus, resu
 			panic(err)
 		}
 		// Replace sql.Connection to allow hypothetical future calls to go over the secure connection
-		var netConn net.Conn = conn
-		sql.Connection = &netConn
-		// Works:
-		//	var netConn net.Conn = conn
-		//	sql.Connection = &netConn
-		// Does not work:
-		//	sql.Connection = &conn // (**ZGrabConnection is not *net.Conn)
-		//  sql.Connection = &(conn.(net.Conn)) // (conn is not an interface)
-		//  sql.Connection = conn.Conn // (cannot use conn.Conn (type tls.Conn) as type *net.Conn)
-		//  sql.Connection = &conn.Conn // (cannot use &conn.Conn (type *tls.Conn) as type *net.Conn)
-		//	sql.Connection = &(conn.Conn.conn) // (cannot refer to unexported field or method conn)
+		sql.Connection = conn
 	}
 	// If we made it this far, the scan was a success.
 	return zgrab2.SCAN_SUCCESS, result, nil
diff --git a/tls.go b/tls.go
index 1012e92..8978a64 100644
--- a/tls.go
+++ b/tls.go
@@ -261,12 +261,12 @@ func (z *TLSConnection) Handshake() error {
 	}
 }
 
-func (t *TLSFlags) GetTLSConnection(conn *net.Conn) (*TLSConnection, error) {
+func (t *TLSFlags) GetTLSConnection(conn net.Conn) (*TLSConnection, error) {
 	cfg, err := t.GetTLSConfig()
 	if err != nil {
 		return nil, fmt.Errorf("Error getting TLSConfig for options: %s", err)
 	}
-	tlsClient := tls.Client(*conn, cfg)
+	tlsClient := tls.Client(conn, cfg)
 	wrappedClient := TLSConnection{
 		Conn:  *tlsClient,
 		flags: t,