From 604f1d0b0362d1db86e7ecd84b4b829f1c519658 Mon Sep 17 00:00:00 2001
From: Henry Camacho <henry.f.camacho@gmail.com>
Date: Mon, 13 Feb 2017 18:47:16 -0600
Subject: [PATCH] Added support for building a packer buffer.

---
 rvpn/packer/packer.go        | 39 ++++++++++++++++++++++++++++++++++++
 rvpn/packer/packer_data.go   |  9 +++++++--
 rvpn/packer/packer_header.go | 29 ++++++++++++++++++++++++---
 rvpn/rvpnmain/run.go         | 13 ++++--------
 4 files changed, 76 insertions(+), 14 deletions(-)

diff --git a/rvpn/packer/packer.go b/rvpn/packer/packer.go
index bba27e6..d418eef 100644
--- a/rvpn/packer/packer.go
+++ b/rvpn/packer/packer.go
@@ -1,5 +1,10 @@
 package packer
 
+import (
+	"bytes"
+	"fmt"
+)
+
 //Packer -- contains both header and data
 type Packer struct {
 	Header *packerHeader
@@ -13,3 +18,37 @@ func NewPacker() (p *Packer) {
 	p.Data = newPackerData()
 	return
 }
+
+//PackV1 -- Outputs version 1 of packer
+func (p *Packer) PackV1() (b bytes.Buffer) {
+	version := byte(1)
+
+	var headerBuf bytes.Buffer
+	headerBuf.WriteString(p.Header.FamilyText())
+	headerBuf.WriteString(",")
+	headerBuf.Write([]byte(p.Header.Address().String()))
+	headerBuf.WriteString(",")
+	headerBuf.WriteString(fmt.Sprintf("%d", p.Header.Port))
+	headerBuf.WriteString(",")
+	headerBuf.WriteString(fmt.Sprintf("%d", p.Data.buffer.Len()))
+	headerBuf.WriteString(",")
+	headerBuf.WriteString(p.Header.Service)
+
+	var metaBuf bytes.Buffer
+	metaBuf.WriteByte(byte(255) - version)
+	metaBuf.WriteByte(byte(headerBuf.Len()))
+
+	var buf bytes.Buffer
+	buf.Write(metaBuf.Bytes())
+	buf.Write(headerBuf.Bytes())
+	buf.Write(p.Data.buffer.Bytes())
+
+	fmt.Println("header: ", headerBuf.String())
+	fmt.Println("meta: ", metaBuf)
+	fmt.Println("Data: ", p.Data.buffer)
+	fmt.Println("Buffer: ", buf.Bytes())
+
+	b = buf
+
+	return
+}
diff --git a/rvpn/packer/packer_data.go b/rvpn/packer/packer_data.go
index 03eda91..dde1942 100644
--- a/rvpn/packer/packer_data.go
+++ b/rvpn/packer/packer_data.go
@@ -4,11 +4,16 @@ import "bytes"
 
 //packerData -- Contains packer data
 type packerData struct {
-	Buffer *bytes.Buffer
+	buffer *bytes.Buffer
 }
 
 func newPackerData() (p *packerData) {
 	p = new(packerData)
-	p.Buffer = new(bytes.Buffer)
+	p.buffer = new(bytes.Buffer)
+	return
+}
+
+func (p packerData) AppendString(dataString string) (n int, err error) {
+	n, err = p.buffer.WriteString(dataString)
 	return
 }
diff --git a/rvpn/packer/packer_header.go b/rvpn/packer/packer_header.go
index 3b29086..f5760be 100644
--- a/rvpn/packer/packer_header.go
+++ b/rvpn/packer/packer_header.go
@@ -3,6 +3,8 @@ package packer
 import "net"
 import "fmt"
 
+type addressFamily int
+
 // packerHeader structure to hold our header information.
 type packerHeader struct {
 	family  addressFamily
@@ -11,15 +13,17 @@ type packerHeader struct {
 	Service string
 }
 
-type addressFamily int
-type addressFamilyString string
-
 //Family -- ENUM for Address Family
 const (
 	FamilyIPv4 addressFamily = iota
 	FamilyIPv6
 )
 
+var addressFamilyText = [...]string{
+	"ipv4",
+	"ipv6",
+}
+
 func newPackerHeader() (p *packerHeader) {
 	p = new(packerHeader)
 	p.SetAddress("127.0.0.1")
@@ -45,6 +49,20 @@ func (p *packerHeader) SetAddress(addr string) {
 	}
 }
 
+func (p *packerHeader) AddressBytes() (b []byte) {
+	b = make([]byte, 16)
+
+	switch {
+	case p.address.To4() != nil:
+		b = make([]byte, 4)
+		for pos := range b {
+			b[pos] = p.address[pos+12]
+		}
+		return
+	}
+	return
+}
+
 func (p *packerHeader) Address() (address net.IP) {
 	address = p.address
 	return
@@ -54,3 +72,8 @@ func (p *packerHeader) Family() (family addressFamily) {
 	family = p.family
 	return
 }
+
+func (p *packerHeader) FamilyText() (familyText string) {
+	familyText = addressFamilyText[p.family]
+	return
+}
diff --git a/rvpn/rvpnmain/run.go b/rvpn/rvpnmain/run.go
index 0e1560e..1f6989c 100644
--- a/rvpn/rvpnmain/run.go
+++ b/rvpn/rvpnmain/run.go
@@ -43,17 +43,12 @@ func Run() {
 	loginfo.Println("startup")
 
 	p := packer.NewPacker()
-	fmt.Println(*p.Header)
-
 	p.Header.SetAddress("127.0.0.2")
-	fmt.Println(*p.Header)
+	p.Header.Port = 32768
+	p.Data.AppendString("A test message")
+	p.PackV1()
 
-	p.Header.SetAddress("2001:db8::1")
-	fmt.Println(*p.Header)
-
-	fmt.Println(p.Header.Address())
-
-	loginfo.Println(p)
+	fmt.Println("-=-=-=-=-=-=-=-=-=-=")
 
 	wssMapping = xlate.NewwssMapping()
 	go wssMapping.Run()