From c9585c36afe0c502c91e5ad527af1c71a80feb0a Mon Sep 17 00:00:00 2001
From: Marin Ivanov <dev@metala.org>
Date: Sun, 24 Mar 2019 22:21:08 +0200
Subject: Add Makefile and configurable delay

---
 .gitignore |  1 +
 Makefile   |  8 ++++++++
 handle.go  |  7 ++++---
 main.go    | 14 +++++++++++---
 ssh.go     |  6 ++----
 5 files changed, 26 insertions(+), 10 deletions(-)
 create mode 100644 .gitignore
 create mode 100644 Makefile

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..906b4bc
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+linux-amd64: build/linux-amd64
+windows-amd64: build/windows-amd64.exe
+
+build/linux-amd64: $(SRC)
+	GOOS=linux GOARCH=amd64 go build -o "$@"
+
+build/windows-amd64.exe: $(SRC)
+	GOOS=windows GOARCH=amd64 go build -o "$@"
diff --git a/handle.go b/handle.go
index 622b68e..918f3a8 100644
--- a/handle.go
+++ b/handle.go
@@ -6,7 +6,8 @@ import (
 	"time"
 )
 
-type protoHandler func(net.Conn)
+type empty struct{}
+type protoHandler func(net.Conn, time.Duration)
 
 func protocolHandler(proto string) (protoHandler, error) {
 	switch proto {
@@ -22,10 +23,10 @@ func logConn(conn net.Conn, msg string) {
 	fmt.Printf("%s, %s, %s\n", now.String(), conn.RemoteAddr().String(), msg)
 }
 
-func connHandler(handler protoHandler, conn net.Conn) {
+func connHandler(handler protoHandler, conn net.Conn, delay time.Duration) {
 	defer conn.Close()
 
 	logConn(conn, "handling")
-	handler(conn)
+	handler(conn, delay)
 	logConn(conn, "closing")
 }
diff --git a/main.go b/main.go
index 8de0a5c..ac4a25a 100644
--- a/main.go
+++ b/main.go
@@ -13,9 +13,11 @@ import (
 func main() {
 	var protocol string
 	var bindAddr string
+	var delayParam string
 	var port int
 
-	flag.StringVarP(&protocol, "proto", "P", "ssh", "protocol to trap")
+	flag.StringVarP(&protocol, "proto", "P", "ssh", "protocol to tarpit")
+	flag.StringVarP(&delayParam, "delay", "d", "10s", "delay between the tarpit keep-alive data packets")
 	flag.StringVarP(&bindAddr, "bind-address", "b", "", "address to bind the socket to")
 	flag.IntVarP(&port, "port", "p", 22, "TCP port")
 	flag.Parse()
@@ -25,14 +27,20 @@ func main() {
 		fmt.Fprintln(os.Stderr, "Error: protocol handler;", err.Error())
 		os.Exit(1)
 	}
+	delay, err := time.ParseDuration(delayParam)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "Error: parse delay;", err.Error())
+		os.Exit(1)
+	}
 
-	rand.Seed(time.Now().UnixNano())
 	bind := fmt.Sprintf("%s:%d", bindAddr, port)
 	ln, err := net.Listen("tcp", bind)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "Error: server listen;", err.Error())
 		os.Exit(1)
 	}
+
+	rand.Seed(time.Now().UnixNano())
 	fmt.Fprintf(os.Stderr, "** Server listening on %s\n", bind)
 	for {
 		conn, err := ln.Accept()
@@ -40,6 +48,6 @@ func main() {
 			// handle error
 			continue
 		}
-		go connHandler(handler, conn)
+		go connHandler(handler, conn, delay)
 	}
 }
diff --git a/ssh.go b/ssh.go
index 3d43a6c..909dc13 100644
--- a/ssh.go
+++ b/ssh.go
@@ -9,16 +9,14 @@ import (
 	"time"
 )
 
-type empty struct{}
-
-func sshHandler(conn net.Conn) {
+func sshHandler(conn net.Conn, delay time.Duration) {
 	eof := make(chan empty)
 	go func() {
 		io.Copy(ioutil.Discard, conn)
 		eof <- empty{}
 	}()
 
-	tick := time.Tick(10 * time.Second)
+	tick := time.Tick(delay)
 	for {
 		select {
 		case <-eof:
-- 
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