Improve read waiter interface

go.mod

@@ -24,11 +24,11 @@ require (
 	github.com/sagernet/gomobile v0.0.0-20230413023804-244d7ff07035
 	github.com/sagernet/quic-go v0.0.0-20230202071646-a8c8afb18b32
 	github.com/sagernet/reality v0.0.0-20230406110435-ee17307e7691
-	github.com/sagernet/sing v0.2.5-0.20230509045155-f60c80c56f21
+	github.com/sagernet/sing v0.2.5-0.20230512033628-9be7806bab51
 	github.com/sagernet/sing-dns v0.1.5-0.20230426113254-25d948c44223
 	github.com/sagernet/sing-mux v0.0.0-20230517134606-1ebe6bb26646
 	github.com/sagernet/sing-shadowsocks v0.2.2-0.20230509053848-d83f8fe1194c
-	github.com/sagernet/sing-shadowsocks2 v0.0.0-20230510062121-18b8e5920cb2
+	github.com/sagernet/sing-shadowsocks2 v0.0.0-20230512030659-23bb92c1eb97
 	github.com/sagernet/sing-shadowtls v0.1.2-0.20230417103049-4f682e05f19b
 	github.com/sagernet/sing-tun v0.1.5-0.20230520041100-b02f2529160e
 	github.com/sagernet/sing-vmess v0.1.5-0.20230417103030-8c3070ae3fb3

go.sum

@@ -113,16 +113,16 @@ github.com/sagernet/reality v0.0.0-20230406110435-ee17307e7691 h1:5Th31OC6yj8byL
 github.com/sagernet/reality v0.0.0-20230406110435-ee17307e7691/go.mod h1:B8lp4WkQ1PwNnrVMM6KyuFR20pU8jYBD+A4EhJovEXU=
 github.com/sagernet/sing v0.0.0-20220817130738-ce854cda8522/go.mod h1:QVsS5L/ZA2Q5UhQwLrn0Trw+msNd/NPGEhBKR/ioWiY=
 github.com/sagernet/sing v0.1.8/go.mod h1:jt1w2u7lJQFFSGLiRrRIs5YWmx4kAPfWuOejuDW9qMk=
-github.com/sagernet/sing v0.2.5-0.20230509045155-f60c80c56f21 h1:voT2nOCvukNfRLn9KxQYEYSu9/OZsCqEmD6tEFJAnBw=
+github.com/sagernet/sing v0.2.5-0.20230512033628-9be7806bab51 h1:ySJuouhl890pBZly51Hkb2mbDnz+qSQCLF5j+4IFHis=
-github.com/sagernet/sing v0.2.5-0.20230509045155-f60c80c56f21/go.mod h1:Ta8nHnDLAwqySzKhGoKk4ZIB+vJ3GTKj7UPrWYvM+4w=
+github.com/sagernet/sing v0.2.5-0.20230512033628-9be7806bab51/go.mod h1:Ta8nHnDLAwqySzKhGoKk4ZIB+vJ3GTKj7UPrWYvM+4w=
 github.com/sagernet/sing-dns v0.1.5-0.20230426113254-25d948c44223 h1:L4eMuM07iSHY3UCknFnuFuHoe5clZuF2Xnf2wwA6Lwc=
 github.com/sagernet/sing-dns v0.1.5-0.20230426113254-25d948c44223/go.mod h1:ZKuuqgsHRxDahYrzgSgy4vIAGGuKPlIf4hLcNzYzLkY=
 github.com/sagernet/sing-mux v0.0.0-20230517134606-1ebe6bb26646 h1:X3ADfMqeGns1Q1FlXc9kaL9FwW1UM6D6tEQo8jFstpc=
 github.com/sagernet/sing-mux v0.0.0-20230517134606-1ebe6bb26646/go.mod h1:pF+RnLvCAOhECrvauy6LYOpBakJ/vuaF1Wm4lPsWryI=
 github.com/sagernet/sing-shadowsocks v0.2.2-0.20230509053848-d83f8fe1194c h1:EiQ+i4gdPpSI8D2YUlOeBZA3R1ZGi0ShSLSXoSd/13A=
 github.com/sagernet/sing-shadowsocks v0.2.2-0.20230509053848-d83f8fe1194c/go.mod h1:UJjvQGw0lyYaDGIDvUraL16fwaAEH1WFw1Y6sUcMPog=
-github.com/sagernet/sing-shadowsocks2 v0.0.0-20230510062121-18b8e5920cb2 h1:ORW4JxNuKAEPtKSGRMS+Qj8tnKqn074FPupLLOrG/UI=
+github.com/sagernet/sing-shadowsocks2 v0.0.0-20230512030659-23bb92c1eb97 h1:Mc5dbIMFF3ph3JofkBv3loq1qdBLktER+LL0IpoLm5M=
-github.com/sagernet/sing-shadowsocks2 v0.0.0-20230510062121-18b8e5920cb2/go.mod h1:i6Eoor37Cy4JKBcelMMFfUVBNjqRYuvcqOBjUI3Zw80=
+github.com/sagernet/sing-shadowsocks2 v0.0.0-20230512030659-23bb92c1eb97/go.mod h1:i6Eoor37Cy4JKBcelMMFfUVBNjqRYuvcqOBjUI3Zw80=
 github.com/sagernet/sing-shadowtls v0.1.2-0.20230417103049-4f682e05f19b h1:ouW/6IDCrxkBe19YSbdCd7buHix7b+UZ6BM4Zz74XF4=
 github.com/sagernet/sing-shadowtls v0.1.2-0.20230417103049-4f682e05f19b/go.mod h1:oG8bPerYI6cZ74KquY3DvA7ynECyrILPBnce6wtBqeI=
 github.com/sagernet/sing-tun v0.1.5-0.20230520041100-b02f2529160e h1:fivkzQowiOPBafklJmNePBu/sr83rsY5SuSakvoJ2A0=

outbound/dns.go

@@ -197,14 +197,12 @@ func (d *DNS) newPacketConnection(ctx context.Context, conn N.PacketConn, readWa
 	var group task.Group
 	group.Append0(func(ctx context.Context) error {
 		var buffer *buf.Buffer
-		newBuffer := func() *buf.Buffer {
+		readWaiter.InitializeReadWaiter(func() *buf.Buffer {
-			if buffer != nil {
-				buffer.Release()
-			}
 			buffer = buf.NewSize(dns.FixedPacketSize)
 			buffer.FullReset()
 			return buffer
-		}
+		})
+		defer readWaiter.InitializeReadWaiter(nil)
 		for {
 			var message mDNS.Msg
 			var destination M.Socksaddr
@@ -223,11 +221,9 @@ func (d *DNS) newPacketConnection(ctx context.Context, conn N.PacketConn, readWa
 				}
 				destination = packet.Destination
 			} else {
-				destination, err = readWaiter.WaitReadPacket(newBuffer)
+				destination, err = readWaiter.WaitReadPacket()
 				if err != nil {
-					if buffer != nil {
+					buffer.Release()
-						buffer.Release()
-					}
 					cancel(err)
 					return err
 				}

transport/fakeip/packet_wait.go

@@ -0,0 +1,37 @@
+package fakeip
+
+import (
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func (c *NATPacketConn) CreatePacketReadWaiter() (N.PacketReadWaiter, bool) {
+	waiter, created := bufio.CreatePacketReadWaiter(c.PacketConn)
+	if !created {
+		return nil, false
+	}
+	return &waitNATPacketConn{c, waiter}, true
+}
+
+type waitNATPacketConn struct {
+	*NATPacketConn
+	waiter N.PacketReadWaiter
+}
+
+func (c *waitNATPacketConn) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
+	c.waiter.InitializeReadWaiter(newBuffer)
+}
+
+func (c *waitNATPacketConn) WaitReadPacket() (destination M.Socksaddr, err error) {
+	destination, err = c.waiter.WaitReadPacket()
+	if socksaddrWithoutPort(destination) == c.origin {
+		destination = M.Socksaddr{
+			Addr: c.destination.Addr,
+			Fqdn: c.destination.Fqdn,
+			Port: destination.Port,
+		}
+	}
+	return
+}