Rewrite mDNS processing

2025-10-05 08:16:55 +08:00 · 2023-07-11 00:44:27 +03:00
parent 4ea5a22eda
commit 73bf96e123
8 changed files with 194 additions and 141 deletions
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ require (
 	github.com/brutella/hap v0.0.17
 	github.com/deepch/vdk v0.0.19
 	github.com/gorilla/websocket v1.5.0
-	github.com/hashicorp/mdns v1.0.5
+	github.com/miekg/dns v1.1.52
 	github.com/pion/ice/v2 v2.3.1
 	github.com/pion/interceptor v0.1.12
 	github.com/pion/rtcp v1.2.10
@@ -31,7 +31,6 @@ require (
 	github.com/kr/pretty v0.2.1 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.17 // indirect
-	github.com/miekg/dns v1.1.52 // indirect
 	github.com/pion/datachannel v1.5.5 // indirect
 	github.com/pion/dtls/v2 v2.2.6 // indirect
 	github.com/pion/logging v0.2.2 // indirect
@@ -52,8 +51,6 @@ require (
 )

 replace (
-	// windows support: https://github.com/brutella/dnssd/pull/35
-	github.com/brutella/dnssd v1.2.2 => github.com/rblenkinsopp/dnssd v1.2.3-0.20220516082132-0923f3c787a1
 	// RTP tlv8 fix
 	github.com/brutella/hap v0.0.17 => github.com/AlexxIT/hap v0.0.15-0.20221108133010-d8a45b7a7045
 	// fix reading AAC config bytes
--- a/go.sum
+++ b/go.sum
@@ -32,8 +32,6 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
 github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
-github.com/hashicorp/mdns v1.0.5 h1:1M5hW1cunYeoXOqHwEb/GBDDHAFo0Yqb/uz/beC6LbE=
-github.com/hashicorp/mdns v1.0.5/go.mod h1:mtBihi+LeNXGtG8L9dX59gAEa12BDtBQSp4v/YAJqrc=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
@@ -48,7 +46,6 @@ github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27k
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.17 h1:BTarxUcIeDqL27Mc+vyvdWYSL28zpIhv3RoTdsLMPng=
 github.com/mattn/go-isatty v0.0.17/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
-github.com/miekg/dns v1.1.41/go.mod h1:p6aan82bvRIyn+zDIv9xYNUpwa73JcSh9BKwknJysuI=
 github.com/miekg/dns v1.1.50/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
 github.com/miekg/dns v1.1.52 h1:Bmlc/qsNNULOe6bpXcUTsuOajd0DzRHwup6D9k1An0c=
 github.com/miekg/dns v1.1.52/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
@@ -148,7 +145,6 @@ golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
-golang.org/x/net v0.0.0-20210410081132-afb366fc7cd1/go.mod h1:9tjilg8BloeKEkVJvy7fQ90B1CfIiPueXVOjqfkSzI8=
 golang.org/x/net v0.0.0-20210428140749-89ef3d95e781/go.mod h1:OJAsFXCWl8Ukc7SiCT/9KSuxbyM7479/AVlXFRxuMCk=
 golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
@@ -175,7 +171,6 @@ golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210303074136-134d130e1a04/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
--- a/internal/homekit/api.go
+++ b/internal/homekit/api.go
@@ -1,12 +1,11 @@
 package homekit

 import (
-	"fmt"
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"github.com/AlexxIT/go2rtc/internal/app/store"
 	"github.com/AlexxIT/go2rtc/internal/streams"
 	"github.com/AlexxIT/go2rtc/pkg/hap"
-	"github.com/AlexxIT/go2rtc/pkg/hap/mdns"
+	"github.com/AlexxIT/go2rtc/pkg/mdns"
 	"net/http"
 	"net/url"
 	"strings"
@@ -32,26 +31,23 @@ func apiHandler(w http.ResponseWriter, r *http.Request) {
 			}
 		}

-		for info := range mdns.GetAll() {
-			if !strings.HasSuffix(info.Name, mdns.Suffix) {
-				continue
-			}
-			name := info.Name[:len(info.Name)-len(mdns.Suffix)]
-			device := Device{
-				Name: strings.ReplaceAll(name, "\\", ""),
-				Addr: fmt.Sprintf("%s:%d", info.AddrV4, info.Port),
-			}
-			for _, field := range info.InfoFields {
-				switch field[:2] {
-				case "id":
-					device.ID = field[3:]
-				case "md":
-					device.Model = field[3:]
-				case "sf":
-					device.Paired = field[3] == '0'
+		err := mdns.Discovery(mdns.ServiceHAP, func(entry *mdns.ServiceEntry) bool {
+			if entry.Complete() {
+				device := Device{
+					Name:   entry.Name,
+					Addr:   entry.Addr(),
+					ID:     entry.Info["id"],
+					Model:  entry.Info["md"],
+					Paired: entry.Info["sf"] == "0",
 				}
+				items = append(items, device)
 			}
-			items = append(items, device)
+			return false
+		})
+
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
 		}

 		api.ResponseJSON(w, items)
--- a/pkg/hap/conn.go
+++ b/pkg/hap/conn.go
@@ -8,7 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/AlexxIT/go2rtc/pkg/core"
-	"github.com/AlexxIT/go2rtc/pkg/hap/mdns"
+	"github.com/AlexxIT/go2rtc/pkg/mdns"
 	"github.com/brutella/hap"
 	"github.com/brutella/hap/chacha20poly1305"
 	"github.com/brutella/hap/curve25519"
@@ -61,28 +61,29 @@ func NewConn(rawURL string) (*Conn, error) {
 }

 func Pair(deviceID, pin string) (*Conn, error) {
-	entry := mdns.GetEntry(deviceID)
-	if entry == nil {
+	var addr string
+	var mfi bool
+
+	_ = mdns.Discovery(mdns.ServiceHAP, func(entry *mdns.ServiceEntry) bool {
+		if entry.Complete() && entry.Info["id"] == deviceID {
+			addr = entry.Addr()
+			mfi = entry.Info["ff"] == "1"
+			return true
+		}
+		return false
+	})
+
+	if addr == "" {
 		return nil, errors.New("can't find device via mDNS")
 	}

 	c := &Conn{
-		DeviceAddress: fmt.Sprintf("%s:%d", entry.AddrV4.String(), entry.Port),
+		DeviceAddress: addr,
 		DeviceID:      deviceID,
 		ClientID:      GenerateUUID(),
 		ClientPrivate: GenerateKey(),
 	}

-	var mfi bool
-	for _, field := range entry.InfoFields {
-		if field[:2] == "ff" {
-			if field[3] == '1' {
-				mfi = true
-			}
-			break
-		}
-	}
-
 	return c, c.Pair(mfi, pin)
 }

@@ -106,9 +107,13 @@ func (c *Conn) DialAndServe() error {

 func (c *Conn) Dial() error {
 	// update device host before dial
-	if host := mdns.GetAddress(c.DeviceID); host != "" {
-		c.DeviceAddress = host
-	}
+	_ = mdns.Discovery(mdns.ServiceHAP, func(entry *mdns.ServiceEntry) bool {
+		if entry.Complete() && entry.Info["id"] == c.DeviceID {
+			c.DeviceAddress = entry.Addr()
+			return true
+		}
+		return false
+	})

 	var err error
 	c.conn, err = net.DialTimeout("tcp", c.DeviceAddress, time.Second*5)
--- a/pkg/hap/mdns/client.go
+++ b/pkg/hap/mdns/client.go
@@ -1,42 +0,0 @@
-package mdns
-
-import (
-	"fmt"
-	"github.com/hashicorp/mdns"
-	"strings"
-)
-
-const Suffix = "._hap._tcp.local."
-
-func GetAll() chan *mdns.ServiceEntry {
-	entries := make(chan *mdns.ServiceEntry)
-	params := &mdns.QueryParam{
-		Service: "_hap._tcp", Entries: entries, DisableIPv6: true,
-	}
-
-	go func() {
-		_ = mdns.Query(params)
-		close(entries)
-	}()
-
-	return entries
-}
-
-func GetAddress(deviceID string) string {
-	for entry := range GetAll() {
-		if strings.Contains(entry.Info, deviceID) {
-			return fmt.Sprintf("%s:%d", entry.AddrV4.String(), entry.Port)
-		}
-	}
-
-	return ""
-}
-
-func GetEntry(deviceID string) *mdns.ServiceEntry {
-	for entry := range GetAll() {
-		if strings.Contains(entry.Info, deviceID) {
-			return entry
-		}
-	}
-	return nil
-}
--- a/pkg/hap/mdns/server.go
+++ b/pkg/hap/mdns/server.go
@@ -1,53 +0,0 @@
-package mdns
-
-import (
-	"github.com/hashicorp/mdns"
-	"net"
-)
-
-const HostHeaderTail = "._hap._tcp.local"
-
-func NewServer(name string, port int, ips []net.IP, txt []string) (*mdns.Server, error) {
-	if ips == nil || ips[0] == nil {
-		ips = LocalIPs()
-	}
-
-	// important to set hostName manually with any value and `.local.` tail
-	// important to set ips manually
-	service, _ := mdns.NewMDNSService(
-		name, "_hap._tcp", "", name+".local.", port, ips, txt,
-	)
-
-	return mdns.NewServer(&mdns.Config{Zone: service})
-}
-
-func LocalIPs() []net.IP {
-	ifaces, err := net.Interfaces()
-	if err != nil {
-		return nil
-	}
-
-	var ips []net.IP
-	for _, iface := range ifaces {
-		if iface.Flags&net.FlagUp == 0 {
-			continue // interface down
-		}
-		if iface.Flags&net.FlagLoopback != 0 {
-			continue // loopback interface
-		}
-
-		var addrs []net.Addr
-		if addrs, err = iface.Addrs(); err != nil {
-			continue
-		}
-		for _, addr := range addrs {
-			switch addr := addr.(type) {
-			case *net.IPNet:
-				ips = append(ips, addr.IP)
-			case *net.IPAddr:
-				ips = append(ips, addr.IP)
-			}
-		}
-	}
-	return ips
-}
--- a/pkg/mdns/mdns.go
+++ b/pkg/mdns/mdns.go
@@ -0,0 +1,139 @@
+package mdns
+
+import (
+	"fmt"
+	"github.com/miekg/dns"
+	"net"
+	"strings"
+	"time"
+)
+
+const ServiceHAP = "_hap._tcp.local." // HomeKit Accessory Protocol
+
+const requestTimeout = time.Millisecond * 505
+const responseTimeout = time.Second * 2
+
+type ServiceEntry struct {
+	Name string
+	IP   net.IP
+	Port uint16
+	Info map[string]string
+}
+
+func (e *ServiceEntry) Complete() bool {
+	return e.IP != nil && e.Port > 0 && e.Info != nil
+}
+
+func (e *ServiceEntry) Addr() string {
+	return fmt.Sprintf("%s:%d", e.IP, e.Port)
+}
+
+func Discovery(service string, onentry func(*ServiceEntry) bool) error {
+	addr := &net.UDPAddr{
+		IP:   net.IP{224, 0, 0, 251},
+		Port: 5353,
+	}
+
+	conn, err := net.ListenMulticastUDP("udp4", nil, addr)
+	if err != nil {
+		return err
+	}
+
+	defer conn.Close()
+
+	if err = conn.SetDeadline(time.Now().Add(responseTimeout)); err != nil {
+		return err
+	}
+
+	msg := &dns.Msg{
+		Question: []dns.Question{
+			{service, dns.TypePTR, dns.ClassINET},
+		},
+	}
+
+	b1, err := msg.Pack()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		for {
+			if _, err := conn.WriteToUDP(b1, addr); err != nil {
+				return
+			}
+			time.Sleep(requestTimeout)
+		}
+	}()
+
+	var skipIPs []net.IP
+
+	b2 := make([]byte, 1500)
+loop:
+	for {
+		n, addr, err := conn.ReadFromUDP(b2)
+		if err != nil {
+			break
+		}
+
+		for _, ip := range skipIPs {
+			if ip.Equal(addr.IP) {
+				continue loop
+			}
+		}
+
+		if err = msg.Unpack(b2[:n]); err != nil {
+			continue
+		}
+
+		if !EqualService(msg, service) {
+			continue
+		}
+
+		if entry := NewServiceEntry(msg); onentry(entry) {
+			break
+		}
+
+		skipIPs = append(skipIPs, addr.IP)
+	}
+
+	return nil
+}
+
+func EqualService(msg *dns.Msg, service string) bool {
+	for _, rr := range msg.Answer {
+		if rr, ok := rr.(*dns.PTR); ok {
+			return strings.HasSuffix(rr.Ptr, service)
+		}
+	}
+
+	return false
+}
+
+func NewServiceEntry(msg *dns.Msg) *ServiceEntry {
+	entry := &ServiceEntry{}
+
+	records := make([]dns.RR, 0, len(msg.Answer)+len(msg.Ns)+len(msg.Extra))
+	records = append(records, msg.Answer...)
+	records = append(records, msg.Ns...)
+	records = append(records, msg.Extra...)
+	for _, record := range records {
+		switch record := record.(type) {
+		case *dns.PTR:
+			if i := strings.IndexByte(record.Ptr, '.'); i > 0 {
+				entry.Name = record.Ptr[:i]
+			}
+		case *dns.A:
+			entry.IP = record.A
+		case *dns.SRV:
+			entry.Port = record.Port
+		case *dns.TXT:
+			entry.Info = make(map[string]string, len(record.Txt))
+			for _, txt := range record.Txt {
+				k, v, _ := strings.Cut(txt, "=")
+				entry.Info[k] = v
+			}
+		}
+	}
+
+	return entry
+}
--- a/pkg/mdns/mdns_test.go
+++ b/pkg/mdns/mdns_test.go
@@ -0,0 +1,16 @@
+package mdns
+
+import (
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestDiscovery(t *testing.T) {
+	onentry := func(entry *ServiceEntry) bool {
+		return true
+	}
+	err := Discovery(ServiceHAP, onentry)
+	//err := Discovery("_ewelink._tcp.local.", time.Second, onentry)
+	// err := Discovery("_googlecast._tcp.local.", time.Second, onentry)
+	require.Nil(t, err)
+}