sysutil: provide os-independent interface

CHANGELOG.md

@@ -26,7 +26,7 @@ and this project adheres to
 
 ### Changed
 
-- Updating and relaunching policy is now OS-dependent ([#2231]).
+- Post-updating relaunch possibility is now determined OS-dependently ([#2231]).
 - Made the mobileconfig HTTP API more robust and predictable, add parameters and
   improve error response ([#2358]).
 - Improved HTTP requests handling and timeouts. ([#2343]).

internal/sysutil/os_freebsd.go

@@ -1,6 +1,5 @@
 //+build freebsd
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
@@ -10,15 +9,11 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 )
 
-// CanBindPrivilegedPorts checks if current process can bind to privileged
-// ports.
-func CanBindPrivilegedPorts() (can bool, err error) {
+func canBindPrivilegedPorts() (can bool, err error) {
 	return HaveAdminRights()
 }
 
-// SetRlimit sets user-specified limit of how many fd's we can use
-// https://github.com/AdguardTeam/AdGuardHome/internal/issues/659.
-func SetRlimit(val uint) {
+func setRlimit(val uint) {
 	var rlim syscall.Rlimit
 	rlim.Max = int64(val)
 	rlim.Cur = int64(val)
@@ -28,12 +23,10 @@ func SetRlimit(val uint) {
 	}
 }
 
-// HaveAdminRights checks if the current user has root (administrator) rights.
-func HaveAdminRights() (bool, error) {
+func haveAdminRights() (bool, error) {
 	return os.Getuid() == 0, nil
 }
 
-// SendProcessSignal sends signal to a process.
-func SendProcessSignal(pid int, sig syscall.Signal) error {
+func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }

internal/sysutil/os_linux.go

@@ -1,6 +1,5 @@
 //+build linux
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
@@ -11,16 +10,12 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-// CanBindPrivilegedPorts checks if current process can bind to privileged
-// ports.
-func CanBindPrivilegedPorts() (can bool, err error) {
+func canBindPrivilegedPorts() (can bool, err error) {
 	cnbs, err := unix.PrctlRetInt(unix.PR_CAP_AMBIENT, unix.PR_CAP_AMBIENT_IS_SET, unix.CAP_NET_BIND_SERVICE, 0, 0)
 	return cnbs == 1, err
 }
 
-// SetRlimit sets user-specified limit of how many fd's we can use
-// https://github.com/AdguardTeam/AdGuardHome/internal/issues/659.
-func SetRlimit(val uint) {
+func setRlimit(val uint) {
 	var rlim syscall.Rlimit
 	rlim.Max = uint64(val)
 	rlim.Cur = uint64(val)
@@ -30,12 +25,10 @@ func SetRlimit(val uint) {
 	}
 }
 
-// HaveAdminRights checks if the current user has root (administrator) rights.
-func HaveAdminRights() (bool, error) {
+func haveAdminRights() (bool, error) {
 	return os.Getuid() == 0, nil
 }
 
-// SendProcessSignal sends signal to a process.
-func SendProcessSignal(pid int, sig syscall.Signal) error {
+func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }

internal/sysutil/os_unix.go

@@ -1,6 +1,5 @@
 //+build aix darwin dragonfly netbsd openbsd solaris
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
@@ -10,15 +9,11 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 )
 
-// CanBindPrivilegedPorts checks if current process can bind to privileged
-// ports.
-func CanBindPrivilegedPorts() (can bool, err error) {
+func canBindPrivilegedPorts() (can bool, err error) {
 	return HaveAdminRights()
 }
 
-// SetRlimit sets user-specified limit of how many fd's we can use
-// https://github.com/AdguardTeam/AdGuardHome/internal/issues/659.
-func SetRlimit(val uint) {
+func setRlimit(val uint) {
 	var rlim syscall.Rlimit
 	rlim.Max = uint64(val)
 	rlim.Cur = uint64(val)
@@ -28,12 +23,10 @@ func SetRlimit(val uint) {
 	}
 }
 
-// HaveAdminRights checks if the current user has root (administrator) rights.
-func HaveAdminRights() (bool, error) {
+func haveAdminRights() (bool, error) {
 	return os.Getuid() == 0, nil
 }
 
-// SendProcessSignal sends signal to a process.
-func SendProcessSignal(pid int, sig syscall.Signal) error {
+func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }

internal/sysutil/os_windows.go

@@ -1,6 +1,5 @@
 //+build windows
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
@@ -10,19 +9,14 @@ import (
 	"golang.org/x/sys/windows"
 )
 
-// CanBindPrivilegedPorts checks if current process can bind to privileged
-// ports.
-func CanBindPrivilegedPorts() (can bool, err error) {
+func canBindPrivilegedPorts() (can bool, err error) {
 	return HaveAdminRights()
 }
 
-// SetRlimit sets user-specified limit of how many fd's we can use
-// https://github.com/AdguardTeam/AdGuardHome/internal/issues/659.
-func SetRlimit(val uint) {
+func setRlimit(val uint) {
 }
 
-// HaveAdminRights checks if the current user has root (administrator) rights.
-func HaveAdminRights() (bool, error) {
+func haveAdminRights() (bool, error) {
 	var token windows.Token
 	h := windows.CurrentProcess()
 	err := windows.OpenProcessToken(h, windows.TOKEN_QUERY, &token)
@@ -43,7 +37,6 @@ func HaveAdminRights() (bool, error) {
 	return true, nil
 }
 
-// SendProcessSignal sends signal to a process.
-func SendProcessSignal(pid int, sig syscall.Signal) error {
+func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return fmt.Errorf("not supported on Windows")
 }

internal/sysutil/syslog.go → internal/sysutil/syslog_others.go

@@ -1,15 +1,13 @@
 //+build !windows,!nacl,!plan9
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
 	"log"
 	"log/syslog"
 )
 
-// ConfigureSyslog reroutes standard logger output to syslog.
-func ConfigureSyslog(serviceName string) error {
+func configureSyslog(serviceName string) error {
 	w, err := syslog.New(syslog.LOG_NOTICE|syslog.LOG_USER, serviceName)
 	if err != nil {
 		return err

internal/sysutil/syslog_windows.go

@@ -1,6 +1,5 @@
 //+build windows nacl plan9
 
-// Package sysutil contains utilities for functions requiring system calls.
 package sysutil
 
 import (
@@ -15,13 +14,12 @@ type eventLogWriter struct {
 	el *eventlog.Log
 }
 
-// Write sends a log message to the Event Log.
+// Write implements io.Writer interface for eventLogWriter.
 func (w *eventLogWriter) Write(b []byte) (int, error) {
 	return len(b), w.el.Info(1, string(b))
 }
 
-// ConfigureSyslog reroutes standard logger output to syslog.
-func ConfigureSyslog(serviceName string) error {
+func configureSyslog(serviceName string) error {
 	// Note that the eventlog src is the same as the service name
 	// Otherwise, we will get "the description for event id cannot be found" warning in every log record
 

internal/sysutil/sysutil.go

@@ -0,0 +1,31 @@
+// Package sysutil contains utilities for functions requiring system calls.
+package sysutil
+
+import "syscall"
+
+// CanBindPrivilegedPorts checks if current process can bind to privileged
+// ports.
+func CanBindPrivilegedPorts() (can bool, err error) {
+	return canBindPrivilegedPorts()
+}
+
+// SetRlimit sets user-specified limit of how many fd's we can use
+// https://github.com/AdguardTeam/AdGuardHome/internal/issues/659.
+func SetRlimit(val uint) {
+	setRlimit(val)
+}
+
+// HaveAdminRights checks if the current user has root (administrator) rights.
+func HaveAdminRights() (bool, error) {
+	return haveAdminRights()
+}
+
+// SendProcessSignal sends signal to a process.
+func SendProcessSignal(pid int, sig syscall.Signal) error {
+	return sendProcessSignal(pid, sig)
+}
+
+// ConfigureSyslog reroutes standard logger output to syslog.
+func ConfigureSyslog(serviceName string) error {
+	return configureSyslog(serviceName)
+}