opt: make TCP Keep-Alives settings practicable (#522)

* opt: make TCP Keep-Alives settings practicable

* chore: correct the year in copyright info

* chore: bump up golangci-lint to v1.55.2

* chore: bump up modules

.github/workflows/test.yml

@@ -48,7 +48,7 @@ jobs:
       - name: Setup and run golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.52.2
+          version: v1.55.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot --timeout 5m
   test:
     needs: lint

.github/workflows/test_gc_opt.yml

@@ -48,7 +48,7 @@ jobs:
       - name: Setup and run golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.52.2
+          version: v1.55.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot --timeout 5m
   test:
     needs: lint

.github/workflows/test_poll_opt.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Setup and run golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.52.2
+          version: v1.55.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot
   test:
     needs: lint

.github/workflows/test_poll_opt_gc_opt.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Setup and run golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.52.2
+          version: v1.55.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot
   test:
     needs: lint

go.mod

@@ -5,8 +5,8 @@ require (
 	github.com/stretchr/testify v1.8.4
 	github.com/valyala/bytebufferpool v1.0.0
 	go.uber.org/zap v1.21.0
-	golang.org/x/sync v0.3.0
-	golang.org/x/sys v0.12.0
+	golang.org/x/sync v0.5.0
+	golang.org/x/sys v0.15.0
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 )
 

go.sum

@@ -45,15 +45,16 @@ golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
-golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

internal/socket/sockopts_darwin.go

@@ -27,13 +27,28 @@ func SetKeepAlivePeriod(fd, secs int) error {
 	if secs <= 0 {
 		return errors.New("invalid time duration")
 	}
-	if err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)); err != nil {
-		return err
+
+	if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {
+		return os.NewSyscallError("setsockopt", err)
+	}
+
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, secs); err != nil {
+		return os.NewSyscallError("setsockopt", err)
 	}
-	switch err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPINTVL, secs)); err {
-	case nil, unix.ENOPROTOOPT: // OS X 10.7 and earlier don't support this option
-	default:
-		return err
+
+	interval := secs / 5
+	if interval == 0 {
+		interval = 1
+	}
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPINTVL, interval); err != nil {
+		// In earlier versions, macOS only supported setting TCP_KEEPALIVE (the equivalent of TCP_KEEPIDLE on other platforms),
+		// but since macOS 10.8 it has supported TCP_KEEPINTVL and TCP_KEEPCNT.
+		// If the current OS is macOS and the error is ENOPROTOOPT, ignore it.
+		if err == unix.ENOPROTOOPT {
+			err = nil
+		}
+		return os.NewSyscallError("setsockopt", err)
 	}
-	return os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, secs))
+
+	return os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPCNT, 5))
 }

internal/socket/sockopts_openbsd.go

@@ -0,0 +1,24 @@
+// Copyright (c) 2024 The Gnet Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package socket
+
+import "golang.org/x/sys/unix"
+
+// SetKeepAlivePeriod sets whether the operating system should send
+// keep-alive messages on the connection and sets period between TCP keep-alive probes.
+func SetKeepAlivePeriod(_, _ int) error {
+	// OpenBSD has no user-settable per-socket TCP keepalive options.
+	return unix.ENOPROTOOPT
+}

internal/socket/sockopts_unix.go

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build linux || freebsd || dragonfly || netbsd || openbsd
-// +build linux freebsd dragonfly netbsd openbsd
+//go:build linux || freebsd || dragonfly || netbsd
+// +build linux freebsd dragonfly netbsd
 
 package socket
 
@@ -30,11 +30,22 @@ func SetKeepAlivePeriod(fd, secs int) error {
 	if secs <= 0 {
 		return errors.New("invalid time duration")
 	}
-	if err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)); err != nil {
-		return err
+
+	if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {
+		return os.NewSyscallError("setsockopt", err)
+	}
+
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPIDLE, secs); err != nil {
+		return os.NewSyscallError("setsockopt", err)
 	}
-	if err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPINTVL, secs)); err != nil {
-		return err
+
+	interval := secs / 5
+	if interval == 0 {
+		interval = 1
+	}
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPINTVL, interval); err != nil {
+		return os.NewSyscallError("setsockopt", err)
 	}
-	return os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPIDLE, secs))
+
+	return os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_KEEPCNT, 5))
 }