From 5f3046319c17f40dc696c3a3ca3645e1deefc5f6 Mon Sep 17 00:00:00 2001
From: Jeffrey Paul <jp@eeqj.com>
Date: Sat, 25 Aug 2018 12:06:53 -0700
Subject: [PATCH] beginning of pakketo keiretsu reimplementation in golang

---
 gopakketo/main.go      | 145 +++++++++++++++++++++++++++++++++++++++++
 gopakketo/package.json |  12 ++++
 2 files changed, 157 insertions(+)
 create mode 100644 gopakketo/main.go
 create mode 100644 gopakketo/package.json

diff --git a/gopakketo/main.go b/gopakketo/main.go
new file mode 100644
index 0000000..8287688
--- /dev/null
+++ b/gopakketo/main.go
@@ -0,0 +1,145 @@
+// based on
+// https://github.com/akrennmair/gopcap/blob/master/tools/pcaptest/pcaptest.go
+
+package main
+
+import (
+	"flag"
+	"fmt"
+    "os"
+	"github.com/akrennmair/gopcap"
+    "github.com/op/go-logging"
+)
+
+var log = logging.MustGetLogger("gpk")
+
+const (
+	TCP_FIN = 1 << iota
+	TCP_SYN
+	TCP_RST
+	TCP_PSH
+	TCP_ACK
+	TCP_URG
+	TCP_ECE
+	TCP_CWR
+	TCP_NS
+)
+
+// it is dumb that go doesn't let me define additional methods
+// on the external package, now these have to be plain funcs
+func isRST(tcp *pcap.Tcphdr) bool {
+    return (tcp.Flags & TCP_RST) != 0
+}
+
+func isACK(tcp *pcap.Tcphdr) bool {
+    return (tcp.Flags & TCP_ACK) != 0
+}
+
+func isFIN(tcp *pcap.Tcphdr) bool {
+    return (tcp.Flags & TCP_FIN) != 0
+}
+
+func min(x uint32, y uint32) uint32 {
+	if x < y {
+		return x
+	}
+	return y
+}
+
+func usage() {
+    fmt.Printf("usage: gopakketo [-d <device> | -r <file>]\n")
+    os.Exit(0)
+}
+
+var logFormat = logging.MustStringFormatter(
+	`%{color}%{time:15:04:05.000} %{shortfunc} ▶ %{level:.4s} %{id:03x}%{color:reset} %{message}`,
+)
+
+func main() {
+
+	loggingBackend := logging.NewLogBackend(os.Stderr, "", 0)
+    backendFormatter := logging.NewBackendFormatter(loggingBackend, logFormat)
+    logging.SetBackend(backendFormatter)
+
+	var device *string = flag.String("d", "", "device")
+	var targetlist *string = flag.String("t", "", "target list e.g. 192.168.0.0/16 or 192.168.0-255.0-255")
+	var portlist *string = flag.String("p", "", "port list e.g. 0-1024 or 22,23,80 or 0-1024,6667")
+	//var outfile *string = flag.String("o", "", "output file")
+    //var expr *string = flag.String("e", "", "filter expression")
+
+	flag.Parse()
+
+    go send(device, targetlist, portlist);
+    receive(device);
+}
+
+func parsePortList (pl *[]uint16, s *string) {
+
+}
+
+func parseTargetList (tl *[]uint32, s *string) {
+
+}
+
+func send(device *string, targetlist *string, portlist *string) {
+
+    pl := make([]uint16, 0)
+    parsePortList(pl, portlist)
+
+    tl := make([]uint32, 0)
+    parseTargetList(tl, targetlist)
+
+}
+
+func sendSyn (device *string, sport uint16, dst uint32, dport uint16) {
+
+}
+
+func receive(device *string) {
+	var pc *pcap.Pcap
+	var err error
+
+	ifs, err := pcap.Findalldevs()
+	if len(ifs) == 0 {
+		panic(fmt.Sprintf("no interfaces found : %s\n", err))
+	}
+
+    if *device != "" {
+		pc, err = pcap.Openlive(*device, 65535, true, 0)
+		if pc == nil {
+			log.Noticef("Openlive(%s) failed: %s\n", *device, err)
+			return
+		}
+		if err != nil {
+			log.Criticalf("Openlive(%s) failed: %s\n", *device, err)
+			return
+        }
+	} else {
+        usage()
+		return
+	}
+	defer pc.Close()
+
+	log.Infof("pcap version: %s\n", pcap.Version())
+
+	for pkt := pc.Next(); pkt != nil; pkt = pc.Next() {
+        pkt.Decode()
+        if pkt.TCP == nil {
+            // we are only interested in TCP for scanning purposes rn
+            continue
+        }
+
+        if !isRST(pkt.TCP) && !isACK(pkt.TCP) {
+            // for scanning we only want RSTs (closed) and ACKs (open)
+            continue
+        }
+
+        if isACK(pkt.TCP) {
+            if isFIN(pkt.TCP) {
+                continue
+            }
+        }
+
+		fmt.Printf("%s\n", pkt.String())
+	}
+}
diff --git a/gopakketo/package.json b/gopakketo/package.json
new file mode 100644
index 0000000..c3b8e5a
--- /dev/null
+++ b/gopakketo/package.json
@@ -0,0 +1,12 @@
+{
+  "author": "sneak",
+  "bugs": {},
+  "gx": {},
+  "gxVersion": "0.12.1",
+  "language": "go",
+  "license": "",
+  "name": "gopakketo",
+  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
+  "version": "0.0.0"
+}
+