initial commit

go.mod

+module github.com/libp2p/go-socket-activation
+
+go 1.13
+
+require (
+	github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f
+	github.com/ipfs/go-log v0.0.1
+	github.com/multiformats/go-multiaddr-net v0.1.0
+)

go.sum

+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f h1:JOrtw2xFKzlg+cbHpyrpLDmnN1HqhBfnX7WDiW7eG2c=
+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
+github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/gxed/hashland/keccakpg v0.0.1 h1:wrk3uMNaMxbXiHibbPO4S0ymqJMm41WiudyFSs7UnsU=
+github.com/gxed/hashland/keccakpg v0.0.1/go.mod h1:kRzw3HkwxFU1mpmPP8v1WyQzwdGfmKFJ6tItnhQ67kU=
+github.com/gxed/hashland/murmur3 v0.0.1 h1:SheiaIt0sda5K+8FLz952/1iWS9zrnKsEJaOJu4ZbSc=
+github.com/gxed/hashland/murmur3 v0.0.1/go.mod h1:KjXop02n4/ckmZSnY2+HKcLud/tcmvhST0bie/0lS48=
+github.com/ipfs/go-log v0.0.1 h1:9XTUN/rW64BCG1YhPK9Hoy3q8nr4gOmHHBpgFdfw6Lc=
+github.com/ipfs/go-log v0.0.1/go.mod h1:kL1d2/hzSpI0thNYjiKfjanbVNU+IIGA/WnNESY9leM=
+github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
+github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
+github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
+github.com/mattn/go-isatty v0.0.5 h1:tHXDdz1cpzGaovsTB+TVB8q90WEokoVmfMqoVcrLUgw=
+github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0OXOcUbGjvZxxijuBwbbmlSxLiuofa+g=
+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
+github.com/minio/sha256-simd v0.0.0-20190131020904-2d45a736cd16 h1:5W7KhL8HVF3XCFOweFD3BNESdnO8ewyYTFT2R+/b8FQ=
+github.com/minio/sha256-simd v0.0.0-20190131020904-2d45a736cd16/go.mod h1:2FMWW+8GMoPweT6+pI63m9YE3Lmw4J71hV56Chs1E/U=
+github.com/mr-tron/base58 v1.1.0 h1:Y51FGVJ91WBqCEabAi5OPUz38eAx8DakuAm5svLcsfQ=
+github.com/mr-tron/base58 v1.1.0/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
+github.com/multiformats/go-multiaddr v0.1.0 h1:fkISCUNDb3xIpCcI6BGlPsQE+ywcxzimOsUnHWnrE74=
+github.com/multiformats/go-multiaddr v0.1.0/go.mod h1:xKVEak1K9cS1VdmPZW3LSIb6lgmoS58qz/pzqmAxV44=
+github.com/multiformats/go-multiaddr-net v0.1.0 h1:ZepO8Ezwovd+7b5XPPDhQhayk1yt0AJpzQBpq9fejx4=
+github.com/multiformats/go-multiaddr-net v0.1.0/go.mod h1:5JNbcfBOP4dnhoZOv10JJVkJO0pCCEf8mTnipAo2UZQ=
+github.com/multiformats/go-multihash v0.0.1 h1:HHwN1K12I+XllBCrqKnhX949Orn4oawPkegHMu2vDqQ=
+github.com/multiformats/go-multihash v0.0.1/go.mod h1:w/5tugSrLEbWqlcgJabL3oHFKTwfvkofsjW2Qa1ct4U=
+github.com/opentracing/opentracing-go v1.0.2 h1:3jA2P6O1F9UOrWVpwrIo17pu01KWvNWg4X946/Y5Zwg=
+github.com/opentracing/opentracing-go v1.0.2/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/whyrusleeping/go-logging v0.0.0-20170515211332-0457bb6b88fc h1:9lDbC6Rz4bwmou+oE6Dt4Cb2BGMur5eR/GYptkKUVHo=
+github.com/whyrusleeping/go-logging v0.0.0-20170515211332-0457bb6b88fc/go.mod h1:bopw91TMyo8J3tvftk8xmU2kPmlrt4nScJQZU2hE5EM=
+golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67 h1:ng3VDlRp5/DHpSWl02R4rM9I+8M2rhmsuLwAMmkLQWE=
+golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/net v0.0.0-20190227160552-c95aed5357e7 h1:C2F/nMkR/9sfUTpvR3QrjBuTdvMUC/cFajkphs1YLQo=
+golang.org/x/net v0.0.0-20190227160552-c95aed5357e7/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sys v0.0.0-20190219092855-153ac476189d/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223 h1:DH4skfRX4EBpamg7iV4ZlCpblAHI6s6TDM39bFZumv8=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

sockets.go

+package sockets
+
+import (
+	"sync"
+
+	logging "github.com/ipfs/go-log"
+	manet "github.com/multiformats/go-multiaddr-net"
+)
+
+var (
+	mu          sync.Mutex
+	log         = logging.Logger("socket-activation")
+	initFn      = func() {}
+	initialized = false
+	listeners   = make(map[string][]manet.Listener)
+	packetConns = make(map[string][]manet.PacketConn)
+)
+
+func initialize() {
+	if !initialized {
+		initFn()
+		initialized = true
+	}
+}
+
+// TakeSockets takes the listeners associated with the given name.
+func TakeListeners(name string) ([]manet.Listener, error) {
+	mu.Lock()
+	defer mu.Unlock()
+	initialize()
+
+	s := listeners[name]
+	delete(listeners, name)
+
+	return s, nil
+}
+
+// ListListeners lists the names of the available listeners.
+func ListListeners() ([]string, error) {
+	mu.Lock()
+	defer mu.Unlock()
+	initialize()
+
+	names := make([]string, 0, len(listeners))
+	for name := range listeners {
+		names = append(names, name)
+	}
+	return names, nil
+}
+
+// TakePacketConns takes the packet connections associated with the given name.
+func TakePacketConns(name string) ([]manet.PacketConn, error) {
+	mu.Lock()
+	defer mu.Unlock()
+	initialize()
+
+	s := packetConns[name]
+	delete(packetConns, name)
+
+	return s, nil
+}
+
+// ListListeners lists the names of the available packet connections.
+func ListPacketConns() ([]string, error) {
+	mu.Lock()
+	defer mu.Unlock()
+	initialize()
+
+	names := make([]string, 0, len(packetConns))
+	for name := range packetConns {
+		names = append(names, name)
+	}
+	return names, nil
+}

sockets_linux.go

+// +build linux
+
+package sockets
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"syscall"
+
+	activation "github.com/coreos/go-systemd/activation"
+	manet "github.com/multiformats/go-multiaddr-net"
+)
+
+func isListening(file *os.File) (bool, error) {
+	ret, err := syscall.GetsockoptInt(int(file.Fd()), syscall.SOL_SOCKET, syscall.SO_ACCEPTCONN)
+	return ret == 1, err
+}
+
+func registerFile(file *os.File) error {
+	listening, err := isListening(file)
+	if err != nil {
+		return fmt.Errorf("failed determine the socket type: %s", err)
+	}
+
+	if listening {
+		listener, err := net.FileListener(file)
+		if err != nil {
+			return fmt.Errorf("failed to convert listener: %s", err)
+		}
+		mal, err := manet.WrapNetListener(listener)
+		if err != nil {
+			return fmt.Errorf("failed to wrap net listener: %s", err)
+		}
+		listeners[file.Name()] = append(listeners[file.Name()], mal)
+	} else {
+		pc, err := net.FilePacketConn(file)
+		if err != nil {
+			return fmt.Errorf("failed to convert to a packet conn: %s", err)
+		}
+		mapc, err := manet.WrapPacketConn(pc)
+		if err != nil {
+			return fmt.Errorf("failed to wrap net packet conn: %s", err)
+		}
+		packetConns[file.Name()] = append(packetConns[file.Name()], mapc)
+	}
+	return nil
+}
+
+func init() {
+	// Initialize lazily as this isn't _free_.
+	initFn = func() {
+		for _, file := range activation.Files(true) {
+			err := registerFile(file)
+			file.Close()
+			if err != nil {
+				log.Errorf("when handling the socket %s: %s", file.Name(), err)
+			}
+		}
+	}
+
+}

sockets_test.go

+package sockets
+
+import (
+	"io/ioutil"
+	"net"
+	"os"
+	"strconv"
+	"testing"
+)
+
+func TestActivation(t *testing.T) {
+	lt, err := net.ListenTCP("tcp", &net.TCPAddr{IP: net.IPv6loopback})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if c, err := lt.SyscallConn(); err == nil {
+		var fd uintptr
+		c.Control(func(nfd uintptr) {
+			fd = nfd
+		})
+		if fd != 3 {
+			t.Fatal("expected fd to be 3")
+		}
+	} else {
+		t.Fatal(err)
+	}
+
+	lu, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv6loopback})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if c, err := lu.SyscallConn(); err == nil {
+		var fd uintptr
+		c.Control(func(nfd uintptr) {
+			fd = nfd
+		})
+		if fd != 4 {
+			t.Fatal("expected fd to be 3")
+		}
+	} else {
+		t.Fatal(err)
+	}
+
+	os.Setenv("LISTEN_FDS", "2")
+	os.Setenv("LISTEN_PID", strconv.Itoa(os.Getpid()))
+	os.Setenv("LISTEN_FDNAMES", "tcp:udp")
+	tcp, err := TakeListeners("tcp")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(tcp) != 1 {
+		t.Fatalf("expected 1 listener, got %d", len(tcp))
+	}
+
+	go func() {
+		l := tcp[0]
+		c, err := l.Accept()
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		c.Write([]byte("foobar"))
+		c.Close()
+	}()
+	c, err := net.DialTCP("tcp", nil, lt.Addr().(*net.TCPAddr))
+	if err != nil {
+		t.Fatal(err)
+	}
+	b, err := ioutil.ReadAll(c)
+	if err != nil {
+		t.Error(err)
+	}
+	if string(b) != "foobar" {
+		t.Error("wrong message")
+	}
+	udp, err := TakePacketConns("udp")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(udp) != 1 {
+		t.Fatalf("expected 1 listener, got %d", len(tcp))
+	}
+	if udp[0].LocalAddr().String() != lu.LocalAddr().String() {
+		t.Fatal("got the wrong udp listener")
+	}
+}