From d767632eedfeabf37283092e7ee0a35229122f6b Mon Sep 17 00:00:00 2001
From: Jeff Carr <jcarr@wit.com>
Date: Sat, 4 May 2019 15:07:21 -0700
Subject: [PATCH] Look up the client IP from the hostname

Signed-off-by: Jeff Carr <jcarr@wit.com>
---
 Makefile           |  2 +-
 server/dnstrace.go |  9 ++++++---
 server/server.go   | 28 +++++++++++++++++++++++++++-
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 7f18058..8803001 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ DNSNAME = $(shell hostname -f)
 all:
 	# 'gaper' is a simple and smart golang tool that just rebuilds every time you change a file
 	# go get -u github.com/maxcnunes/gaper
-	gaper
+	# gaper
 
 push:
 	git pull
diff --git a/server/dnstrace.go b/server/dnstrace.go
index d4a42c5..e845957 100644
--- a/server/dnstrace.go
+++ b/server/dnstrace.go
@@ -2,7 +2,7 @@
 
 package main
 
-import "flag"
+// import "flag"
 import "fmt"
 import "log"
 import "net"
@@ -13,6 +13,8 @@ import "time"
 import "github.com/miekg/dns"
 import "github.com/rs/dnstrace/client"
 
+// import "github.com/davecgh/go-spew/spew"
+
 const (
 	cReset    = 0
 	cBold     = 1
@@ -34,14 +36,15 @@ func colorize(s interface{}, color int, enabled bool) string {
 }
 
 func dnstrace(hostname string, qtypestr string) dns.RR {
-	color := flag.Bool("color", true, "Enable/disable colors")
+	// color := flag.Bool("color", true, "Enable/disable colors")
+	color := true
 
 	qname := dns.Fqdn(hostname)
 	// qtype := dns.TypeA
 	qtype := dns.StringToType[qtypestr]
 
 	col := func(s interface{}, c int) string {
-		return colorize(s, c, *color)
+		return colorize(s, c, color)
 	}
 
 	m := &dns.Msg{}
diff --git a/server/server.go b/server/server.go
index 8dbfc3c..7ab7005 100644
--- a/server/server.go
+++ b/server/server.go
@@ -76,8 +76,34 @@ func random() int {
 	return rand.Intn(MAX-MIN) + MIN
 }
 
+func getRemoteAddr(c net.Conn) string {
+	clientAddr := c.RemoteAddr().String()
+	return clientAddr
+}
+
+//
+// Handle each connection
+// Each client must send it's hostname as the first line
+// Then each hostname is verified with DNSSEC
+//
 func handleConnection(c net.Conn) {
-	log.Printf("Serving %s\n", c.RemoteAddr().String())
+	ipv6client := getRemoteAddr(c)
+	log.Println("Serving to %s as the IPv6 client", ipv6client)
+	
+	log.Println("Waiting for the client to tell me its name")
+	netData, err := bufio.NewReader(c).ReadString('\n')
+	if err != nil {
+		log.Println(err)
+		return
+	}
+	clientHostname := strings.TrimSpace(netData)
+	log.Println("Recieved client hostname as:", clientHostname)
+
+	dnsRR := dnstrace(clientHostname, "AAAA")
+	ipaddr := dns.Field(dnsRR, 1)
+	log.Println("Client claims to be:   ", ipaddr)
+	log.Println("Serving to IPv6 client:", ipv6client)
+
 	for {
 		netData, err := bufio.NewReader(c).ReadString('\n')
 		if err != nil {