Updates

hosts.go

@@ -10,49 +10,62 @@ import (
 
 	"github.com/hoisie/redis"
 	"golang.org/x/net/publicsuffix"
+	"github.com/fsnotify/fsnotify"
 )
 
 type Hosts struct {
-	fileHosts       *FileHosts
-	redisHosts      *RedisHosts
+	providers []HostProvider
 	refreshInterval time.Duration
 }
 
-func NewHosts(hs HostsSettings, rs RedisSettings) Hosts {
-	fileHosts := &FileHosts{
-		file:  hs.HostsFile,
-		hosts: make(map[string]string),
+type HostProvider interface {
+	Get(domain string) ([]string, bool)
+	Refresh()
+}
+
+func NewHosts(hs HostsSettings, rs RedisSettings) Hosts {
+	providers := []HostProvider{
+		NewFileProvider(hs.HostsFile),
 	}
 
-	var redisHosts *RedisHosts
 	if hs.RedisEnable {
 		rc := &redis.Client{Addr: rs.Addr(), Db: rs.DB, Password: rs.Password}
-		redisHosts = &RedisHosts{
-			redis: rc,
-			key:   hs.RedisKey,
-			hosts: make(map[string]string),
-		}
+
+		providers = append(providers, NewRedisProvider(rc, hs.RedisKey))
 	}
 
-	hosts := Hosts{fileHosts, redisHosts, time.Second * time.Duration(hs.RefreshInterval)}
-	hosts.refresh()
-	return hosts
+	return Hosts{providers, time.Second * time.Duration(hs.RefreshInterval)}
+}
 
+func (h *Hosts) refresh() {
+	ticker := time.NewTicker(h.refreshInterval)
+
+	go func() {
+		for {
+			// Force a refresh every refreshInterval
+			for _, provider := range h.providers {
+				provider.Refresh()
+			}
+
+			<-ticker.C
+		}
+	}()
 }
 
 /*
 Match local /etc/hosts file first, remote redis records second
 */
 func (h *Hosts) Get(domain string, family int) ([]net.IP, bool) {
-
 	var sips []string
+	var ok bool
 	var ip net.IP
 	var ips []net.IP
 
-	sips, ok := h.fileHosts.Get(domain)
-	if !ok {
-		if h.redisHosts != nil {
-			sips, ok = h.redisHosts.Get(domain)
+	for _, provider := range h.providers {
+		sips, ok = provider.Get(domain)
+
+		if ok {
+			break
 		}
 	}
 
@@ -74,32 +87,55 @@ func (h *Hosts) Get(domain string, family int) ([]net.IP, bool) {
 		}
 	}
 
-	return ips, (ips != nil)
-}
-
-/*
-Update hosts records from /etc/hosts file and redis per minute
-*/
-func (h *Hosts) refresh() {
-	ticker := time.NewTicker(h.refreshInterval)
-	go func() {
-		for {
-			h.fileHosts.Refresh()
-			if h.redisHosts != nil {
-				h.redisHosts.Refresh()
-			}
-			<-ticker.C
-		}
-	}()
+	return ips, ips != nil
 }
 
 type RedisHosts struct {
+	HostProvider
+
 	redis *redis.Client
 	key   string
 	hosts map[string]string
 	mu    sync.RWMutex
 }
 
+func NewRedisProvider(rc *redis.Client, key string) HostProvider {
+	rh := &RedisHosts{
+		redis: rc,
+		key: key,
+		hosts: make(map[string]string),
+	}
+
+	// Use pubsub to listen for key update events
+	go func() {
+		sub := make(chan string, 2)
+		sub <- "godns:update"
+		sub <- "godns:update_record"
+		messages := make(chan redis.Message, 0)
+		go rc.Subscribe(sub, nil, nil, nil, messages)
+
+		for {
+			msg := <- messages
+
+			if msg.Channel == "godns:update" {
+				rh.Refresh()
+			} else if msg.Channel == "godns:update_record" {
+				recordName := string(msg.Message)
+
+				b, err := rc.Hget(key, recordName)
+
+				if err != nil {
+					continue
+				}
+
+				rh.hosts[recordName] = string(b)
+			}
+		}
+	}()
+
+	return rh
+}
+
 func (r *RedisHosts) Get(domain string) ([]string, bool) {
 	r.mu.RLock()
 	defer r.mu.RUnlock()
@@ -152,11 +188,39 @@ func (r *RedisHosts) clear() {
 }
 
 type FileHosts struct {
+	HostProvider
+
 	file  string
 	hosts map[string]string
 	mu    sync.RWMutex
 }
 
+func NewFileProvider(file string) HostProvider {
+	fp := &FileHosts{
+		file: file,
+		hosts: make(map[string]string),
+	}
+
+	watcher, err := fsnotify.NewWatcher()
+
+	// Use fsnotify to notify us of host file changes
+	if err == nil {
+		watcher.Add(file)
+
+		go func() {
+			for {
+				e := <- watcher.Events
+
+				if e.Op == fsnotify.Write {
+					fp.Refresh()
+				}
+			}
+		}()
+	}
+
+	return fp
+}
+
 func (f *FileHosts) Get(domain string) ([]string, bool) {
 	f.mu.RLock()
 	defer f.mu.RUnlock()

resolver.go

@@ -48,36 +48,51 @@ func NewResolver(c ResolvSettings) *Resolver {
 
 	if len(c.ResolvFile) > 0 {
 		clientConfig, err := dns.ClientConfigFromFile(c.ResolvFile)
+
 		if err != nil {
 			logger.Error(":%s is not a valid resolv.conf file\n", c.ResolvFile)
 			logger.Error("%s", err)
 			panic(err)
 		}
+
 		for _, server := range clientConfig.Servers {
-			nameserver := net.JoinHostPort(server, clientConfig.Port)
-			r.servers = append(r.servers, nameserver)
+			r.servers = append(r.servers, net.JoinHostPort(server, clientConfig.Port))
 		}
 	}
 
+	if len(c.DOHServer) > 0 {
+		r.servers = append([]string{c.DOHServer}, r.servers...)
+	}
+
 	return r
 }
 
 func (r *Resolver) parseServerListFile(buf *os.File) {
 	scanner := bufio.NewScanner(buf)
+
+	var line string
+	var idx int
+
 	for scanner.Scan() {
-		line := scanner.Text()
-		line = strings.TrimSpace(line)
+		line = strings.TrimSpace(scanner.Text())
 
 		if !strings.HasPrefix(line, "server") {
 			continue
 		}
 
+		idx = strings.Index(line, "=")
+
+		if idx == -1 {
+			continue
+		}
+
 		sli := strings.Split(line, "=")
+
 		if len(sli) != 2 {
 			continue
 		}
 
-		line = strings.TrimSpace(sli[1])
+		line = strings.TrimSpace(line[idx:])
 
 		tokens := strings.Split(line, "/")
 		switch len(tokens) {
@@ -88,25 +103,31 @@ func (r *Resolver) parseServerListFile(buf *os.File) {
 			if !isDomain(domain) || !isIP(ip) {
 				continue
 			}
+
 			r.domain_server.sinsert(strings.Split(domain, "."), ip)
 		case 1:
 			srv_port := strings.Split(line, "#")
+
 			if len(srv_port) > 2 {
 				continue
 			}
 
 			ip := ""
+
 			if ip = srv_port[0]; !isIP(ip) {
 				continue
 			}
 
 			port := "53"
+
 			if len(srv_port) == 2 {
 				if _, err := strconv.Atoi(srv_port[1]); err != nil {
 					continue
 				}
+
 				port = srv_port[1]
 			}
+
 			r.servers = append(r.servers, net.JoinHostPort(ip, port))
 		}
 	}
@@ -135,6 +156,12 @@ func (r *Resolver) Lookup(net string, req *dns.Msg) (message *dns.Msg, err error
 		WriteTimeout: r.Timeout(),
 	}
 
+	httpC := &dns.Client{
+		Net: "https",
+		ReadTimeout: r.Timeout(),
+		WriteTimeout: r.Timeout(),
+	}
+
 	if net == "udp" && settings.ResolvConfig.SetEDNS0 {
 		req = req.SetEdns0(65535, true)
 	}
@@ -145,7 +172,17 @@ func (r *Resolver) Lookup(net string, req *dns.Msg) (message *dns.Msg, err error
 	var wg sync.WaitGroup
 	L := func(nameserver string) {
 		defer wg.Done()
-		r, rtt, err := c.Exchange(req, nameserver)
+
+		var r *dns.Msg
+		var rtt time.Duration
+		var err error
+
+		if strings.HasPrefix(nameserver, "https") {
+			r, rtt, err = httpC.Exchange(req, nameserver)
+		} else {
+			r, rtt, err = c.Exchange(req, nameserver)
+		}
+
 		if err != nil {
 			logger.Warn("%s socket error on %s", qname, nameserver)
 			logger.Warn("error:%s", err.Error())
@@ -215,6 +252,7 @@ func (r *Resolver) Nameservers(qname string) []string {
 	for _, nameserver := range r.servers {
 		ns = append(ns, nameserver)
 	}
+
 	return ns
 }
 

settings.go

@@ -39,6 +39,7 @@ type ResolvSettings struct {
 	SetEDNS0       bool
 	ServerListFile string `toml:"server-list-file"`
 	ResolvFile     string `toml:"resolv-file"`
+	DOHServer      string `toml:"dns-over-https"`
 }
 
 type DNSServerSettings struct {