[tor-commits] [goptlib/master] Put a timeout on waiting for SOCKS requests.

[dcf at torproject.org]

commit a2caf0477a51840f266f7f026bf3fdf6da81f8b2
Author: David Fifield <david at bamsoftware.com>
Date:   Thu Dec 12 22:29:20 2013 -0800

    Put a timeout on waiting for SOCKS requests.
    
    This is just to stymie attacks or bugs that have a client keeping a TCP
    connectino open forever.
---
 socks.go |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/socks.go b/socks.go
index bd57f40..7a2b1c8 100644
--- a/socks.go
+++ b/socks.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"time"
 )
 
 const (
@@ -16,6 +17,9 @@ const (
 	socksRequestRejected = 0x5b
 )
 
+// Put a sanity timeout on how long we wait for a SOCKS request.
+const socksRequestTimeout = 5 * time.Second
+
 // SocksRequest describes a SOCKS request.
 type SocksRequest struct {
 	// The endpoint requested by the client as a "host:port" string.
@@ -108,11 +112,19 @@ func (ln *SocksListener) AcceptSocks() (*SocksConn, error) {
 	}
 	conn := new(SocksConn)
 	conn.Conn = c
+	err = conn.SetDeadline(time.Now().Add(socksRequestTimeout))
+	if err != nil {
+		return nil, err
+	}
 	conn.Req, err = readSocks4aConnect(conn)
 	if err != nil {
 		conn.Close()
 		return nil, err
 	}
+	err = conn.SetDeadline(time.Time{})
+	if err != nil {
+		return nil, err
+	}
 	return conn, nil
 }