Support multiple A entries refer: #17

README.md

@@ -90,10 +90,6 @@ host-file = "/etc/hosts"
 Hosts file format is described in [linux man pages](http://man7.org/linux/man-pages/man5/hosts.5.html). 
 More than that , `*.` wildcard is supported additional.
 
-```
-127.0.0.1 *.example.com
-```
-
 
 __redis hosts__ 
 
@@ -114,6 +110,18 @@ _Insert hosts records into redis_
 redis > hset godns:hosts www.test.com 1.1.1.1
 ```
 
+Compared with file-backend records, redis-backend hosts support two advanced records formatting.
+
+1. `*.` wildcard
+
+```
+redis > hset 127.0.0.1 *.example.com
+```
+2. Multiple A entries, delimited by commas
+
+```
+redis > hset www.test.com 1.1.1.1,2.2.2.2
+```
 
 
 ## Benchmark

handler.go

@@ -98,7 +98,7 @@ func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
 
 	// Query hosts
 	if settings.Hosts.Enable && IPQuery > 0 {
-		if ip, ok := h.hosts.Get(Q.qname, IPQuery); ok {
+		if ips, ok := h.hosts.Get(Q.qname, IPQuery); ok {
 			m := new(dns.Msg)
 			m.SetReply(req)
 
@@ -110,8 +110,10 @@ func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
 					Class:  dns.ClassINET,
 					Ttl:    settings.Hosts.TTL,
 				}
-				a := &dns.A{rr_header, ip}
-				m.Answer = append(m.Answer, a)
+				for _, ip := range ips {
+					a := &dns.A{rr_header, ip}
+					m.Answer = append(m.Answer, a)
+				}
 			case _IP6Query:
 				rr_header := dns.RR_Header{
 					Name:   q.Name,
@@ -119,8 +121,10 @@ func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
 					Class:  dns.ClassINET,
 					Ttl:    settings.Hosts.TTL,
 				}
-				aaaa := &dns.AAAA{rr_header, ip}
-				m.Answer = append(m.Answer, aaaa)
+				for _, ip := range ips {
+					aaaa := &dns.AAAA{rr_header, ip}
+					m.Answer = append(m.Answer, aaaa)
+				}
 			}
 
 			w.WriteMsg(m)

hosts.go

@@ -34,29 +34,38 @@ func NewHosts(hs HostsSettings, rs RedisSettings) Hosts {
 /*
 Match local /etc/hosts file first, remote redis records second
 */
-func (h *Hosts) Get(domain string, family int) (ip net.IP, ok bool) {
+func (h *Hosts) Get(domain string, family int) ([]net.IP, bool) {
 
-	var sip string
+	var sips []string
+	var ip net.IP
+	var ips []net.IP
 
-	if sip, ok = h.fileHosts.Get(domain); !ok {
+	sips, ok := h.fileHosts.Get(domain)
+	if !ok {
 		if h.redisHosts != nil {
-			sip, ok = h.redisHosts.Get(domain)
+			sips, ok = h.redisHosts.Get(domain)
 		}
 	}
 
-	if sip == "" {
+	if sips == nil {
 		return nil, false
 	}
 
-	switch family {
-	case _IP4Query:
-		ip = net.ParseIP(sip).To4()
-	case _IP6Query:
-		ip = net.ParseIP(sip).To16()
-	default:
-		return nil, false
+	for _, sip := range sips {
+		switch family {
+		case _IP4Query:
+			ip = net.ParseIP(sip).To4()
+		case _IP6Query:
+			ip = net.ParseIP(sip).To16()
+		default:
+			continue
+		}
+		if ip != nil {
+			ips = append(ips, ip)
+		}
 	}
-	return ip, (ip != nil)
+
+	return ips, (ips != nil)
 }
 
 /*
@@ -85,21 +94,21 @@ type RedisHosts struct {
 	hosts map[string]string
 }
 
-func (r *RedisHosts) Get(domain string) (ip string, ok bool) {
-	ip, ok = r.hosts[domain]
+func (r *RedisHosts) Get(domain string) ([]string, bool) {
+	ip, ok := r.hosts[domain]
 	if ok {
-		return
+		return strings.Split(ip, ","), true
 	}
 
 	for host, ip := range r.hosts {
 		if strings.HasPrefix(host, "*.") {
 			upperLevelDomain := strings.Split(host, "*.")[1]
 			if strings.HasSuffix(domain, upperLevelDomain) {
-				return ip, true
+				return strings.Split(ip, ","), true
 			}
 		}
 	}
-	return
+	return nil, false
 }
 
 func (r *RedisHosts) Set(domain, ip string) (bool, error) {
@@ -120,9 +129,12 @@ type FileHosts struct {
 	hosts map[string]string
 }
 
-func (f *FileHosts) Get(domain string) (ip string, ok bool) {
-	ip, ok = f.hosts[domain]
-	return
+func (f *FileHosts) Get(domain string) ([]string, bool) {
+	ip, ok := f.hosts[domain]
+	if !ok {
+		return nil, false
+	}
+	return []string{ip}, true
 }
 
 func (f *FileHosts) Refresh() {