From d22885557fb0b06036c98a86bed68c1bd93291c5 Mon Sep 17 00:00:00 2001
From: kenshin <kenshin.acs@gmail.com>
Date: Fri, 26 Jul 2013 12:06:16 +0800
Subject: [PATCH] read local hosts file

---
 godns.conf  |  5 +++++
 handler.go  |  8 ++++++--
 hosts.go    | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 settings.go |  6 ++++++
 4 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 hosts.go

diff --git a/godns.conf b/godns.conf
index d6bd407..7a312f3 100644
--- a/godns.conf
+++ b/godns.conf
@@ -32,3 +32,8 @@ file = ""
 backend = "memory"  
 expire = 600  # 10 minutes
 maxcount = 100000
+
+[hosts]
+host-file = "/etc/hosts"
+redis-key = "godns:hosts"
+
diff --git a/handler.go b/handler.go
index 53a70d2..0a21e68 100644
--- a/handler.go
+++ b/handler.go
@@ -71,7 +71,7 @@ func (h *GODNSHandler) do(net string, w dns.ResponseWriter, req *dns.Msg) {
 
 	key := KeyGen(Q)
 	// Only query cache when qtype == 'A' , qclass == 'IN'
-	if q.Qtype == dns.TypeA && q.Qclass == dns.ClassINET {
+	if h.isIPQuery(q) {
 		mesg, err := h.cache.Get(key)
 		if err != nil {
 			Debug("%s didn't hit cache: %s", Q.String(), err)
@@ -94,7 +94,7 @@ func (h *GODNSHandler) do(net string, w dns.ResponseWriter, req *dns.Msg) {
 
 	w.WriteMsg(mesg)
 
-	if q.Qtype == dns.TypeA && q.Qclass == dns.ClassINET {
+	if h.isIPQuery(q) {
 		err = h.cache.Set(key, mesg)
 
 		if err != nil {
@@ -113,3 +113,7 @@ func (h *GODNSHandler) DoTCP(w dns.ResponseWriter, req *dns.Msg) {
 func (h *GODNSHandler) DoUDP(w dns.ResponseWriter, req *dns.Msg) {
 	h.do("udp", w, req)
 }
+
+func (h *GODNSHandler) isIPQuery(q dns.Question) bool {
+	return q.Qtype == dns.TypeA && q.Qclass == dns.ClassINET
+}
diff --git a/hosts.go b/hosts.go
new file mode 100644
index 0000000..c448765
--- /dev/null
+++ b/hosts.go
@@ -0,0 +1,59 @@
+package main
+
+import (
+	"github.com/hoisie/redis"
+	// "github.com/miekg/dns"
+	"fmt"
+	"io/ioutil"
+)
+
+type HostsQueryFaild struct {
+	domain string
+}
+
+func (e HostsQueryFaild) Error() string {
+	return e.domain + " hosts match failed"
+}
+
+func readLocalHostsFile(file string) map[string]string {
+	var hosts = make(map[string]string)
+	f, _ := os.Open(file)
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+
+		line := scanner.Text()
+		line = strings.TrimSpace(line)
+
+		if strings.HasPrefix(line, "#") || line == "" {
+			continue
+		}
+
+		sli := strings.Split(line, " ")
+		if len(sli) == 1 {
+			sli = strings.Split(line, "\t")
+		}
+
+		if len(sli) < 2 {
+			continue
+		}
+
+		domain := sli[len(sli)-1]
+		ip := sli[0]
+		if !isDomain(domain) || !isIP(ip) {
+			continue
+		}
+
+		hosts[domain] = ip
+	}
+	return hosts
+}
+
+func isDomain(domain string) bool {
+	match, _ := regexp.MatchString("^[a-z]", domain)
+	return match
+}
+
+func isIP(ip string) bool {
+	match, _ := regexp.MatchString("^[1-9]", ip)
+	return match
+}
diff --git a/settings.go b/settings.go
index d3ff306..30a89f9 100644
--- a/settings.go
+++ b/settings.go
@@ -19,6 +19,7 @@ type Settings struct {
 	Redis        RedisSettings     `toml:"redis"`
 	Log          LogSettings       `toml:"log"`
 	Cache        CacheSettings     `toml:"cache"`
+	Hosts        HostsSettings     `toml:"hosts"`
 }
 
 type ResolvSettings struct {
@@ -48,6 +49,11 @@ type CacheSettings struct {
 	Maxcount int
 }
 
+type HostsSettings struct {
+	HostsFile string `toml:"host-file"`
+	RedisKey  string `toml:"redis-key"`
+}
+
 func init() {
 
 	var configFile string