Add create darwin tun from file descriptor

Makefile

@@ -1,11 +1,11 @@
 fmt:
 	@gofumpt -l -w .
 	@gofmt -s -w .
-	@gci write -s "standard,prefix(github.com/sagernet/),default" .
+	@gci write --custom-order -s "standard,prefix(github.com/sagernet/),default" .
 
 fmt_install:
 	go install -v mvdan.cc/gofumpt@latest
-	go install -v github.com/daixiang0/gci@v0.4.0
+	go install -v github.com/daixiang0/gci@latest
 
 lint:
 	GOOS=linux golangci-lint run .

go.mod

@@ -6,9 +6,9 @@ require (
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/sagernet/go-tun2socks v1.16.12-0.20220818015926-16cb67876a61
 	github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97
-	github.com/sagernet/sing v0.1.2
-	golang.org/x/net v0.4.0
-	golang.org/x/sys v0.3.0
+	github.com/sagernet/sing v0.1.7
+	golang.org/x/net v0.7.0
+	golang.org/x/sys v0.5.0
 	gvisor.dev/gvisor v0.0.0-20220901235040-6ca97ef2ce1c
 )
 

go.sum

@@ -2,24 +2,22 @@ github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/google/btree v1.0.1 h1:gK4Kx5IaGY9CD5sPJ36FHiBJ6ZXl0kilRiiCj+jdYp4=
 github.com/google/btree v1.0.1/go.mod h1:xXMiIv4Fb/0kKde4SpL7qlzvu5cMJDRkFDxJfI9uaxA=
-github.com/sagernet/abx-go v0.0.0-20220819185957-dba1257d738e h1:5CFRo8FJbCuf5s/eTBdZpmMbn8Fe2eSMLNAYfKanA34=
-github.com/sagernet/abx-go v0.0.0-20220819185957-dba1257d738e/go.mod h1:qbt0dWObotCfcjAJJ9AxtFPNSDUfZF+6dCpgKEOBn/g=
 github.com/sagernet/go-tun2socks v1.16.12-0.20220818015926-16cb67876a61 h1:5+m7c6AkmAylhauulqN/c5dnh8/KssrE9c93TQrXldA=
 github.com/sagernet/go-tun2socks v1.16.12-0.20220818015926-16cb67876a61/go.mod h1:QUQ4RRHD6hGGHdFMEtR8T2P6GS6R3D/CXKdaYHKKXms=
 github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97 h1:iL5gZI3uFp0X6EslacyapiRz7LLSJyr4RajF/BhMVyE=
 github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97/go.mod h1:xLnfdiJbSp8rNqYEdIW/6eDO4mVoogml14Bh2hSiFpM=
 github.com/sagernet/sing v0.0.0-20220817130738-ce854cda8522/go.mod h1:QVsS5L/ZA2Q5UhQwLrn0Trw+msNd/NPGEhBKR/ioWiY=
-github.com/sagernet/sing v0.1.2 h1:rp5AqY23P0klk2IaLEI0/WJsD8FTVlv9TaI2QSL6TDA=
-github.com/sagernet/sing v0.1.2/go.mod h1:bvmen56QnVbMrWy+nr5nsbz7U5MUPuY0L0S/XfhCsTs=
+github.com/sagernet/sing v0.1.7 h1:g4vjr3q8SUlBZSx97Emz5OBfSMBxxW5Q8C2PfdoSo08=
+github.com/sagernet/sing v0.1.7/go.mod h1:jt1w2u7lJQFFSGLiRrRIs5YWmx4kAPfWuOejuDW9qMk=
 github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74 h1:gga7acRE695APm9hlsSMoOoE65U4/TcqNj90mc69Rlg=
 github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74/go.mod h1:DD4vA1DwXk04H54A1oHXtwZmA0grkVMdPxx/VGLCah0=
-golang.org/x/net v0.4.0 h1:Q5QPcMlvfxFTAPV0+07Xz/MpK9NTXu2VDUuy0FeMfaU=
-golang.org/x/net v0.4.0/go.mod h1:MBQ8lrhLObU/6UmLb4fmbmk5OcyYmqtbGd/9yIeKjEE=
+golang.org/x/net v0.7.0 h1:rJrUqqhjsgNp7KqAIc25s9pZnjU7TUcSY7HcVZjdn1g=
+golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
 golang.org/x/sys v0.0.0-20200217220822-9197077df867/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20220731174439-a90be440212d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
-golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0 h1:/5xXl8Y5W96D+TtHSlonuFqGHIWVuyCkGJLwGh9JJFs=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 gvisor.dev/gvisor v0.0.0-20220901235040-6ca97ef2ce1c h1:m5lcgWnL3OElQNVyp3qcncItJ2c0sQlSGjYK2+nJTA4=

tun_darwin.go

@@ -45,6 +45,11 @@ func Open(options Options) (Tun, error) {
 		unix.Close(tunFd)
 		return nil, err
 	}
+
+	return FromFileDescriptor(tunFd, options)
+}
+
+func FromFileDescriptor(tunFd int, options Options) (Tun, error) {
 	nativeTun := &NativeTun{
 		tunFile: os.NewFile(uintptr(tunFd), "utun"),
 		mtu:     options.MTU,