minio/cmd/checkport.go
Bala FA cc1575f944 fix: do port availability check only on macOS. (#3654)
On macOS, if a process already listens on 127.0.0.1:PORT, net.Listen() falls back
to IPv6 address ie minio will start listening on IPv6 address whereas another
(non-)minio process is listening on IPv4 of given port.
To avoid this error sutiation we check for port availability only for macOS.

Note: checkPortAvailability() tries to listen on given port and closes it.
It is possible to have a disconnected client in this tiny window of time.
2017-01-30 00:44:36 -08:00

64 lines
1.7 KiB
Go

/*
* Minio Cloud Storage, (C) 2016 Minio, Inc.
*
* 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 cmd
import (
"net"
"os"
"syscall"
)
// checkPortAvailability - check if given port is already in use.
// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func checkPortAvailability(port string) error {
network := [3]string{"tcp", "tcp4", "tcp6"}
for _, n := range network {
l, err := net.Listen(n, net.JoinHostPort("", port))
if err != nil {
if isAddrInUse(err) {
// Return error if another process is listening on the
// same port.
return err
}
// Ignore any other error (ex. EAFNOSUPPORT)
continue
}
// look for error so we don't have dangling connection
if err = l.Close(); err != nil {
return err
}
}
return nil
}
// Return true if err is "address already in use" error.
// syscall.EADDRINUSE is available on all OSes.
func isAddrInUse(err error) bool {
if opErr, ok := err.(*net.OpError); ok {
if sysErr, ok := opErr.Err.(*os.SyscallError); ok {
if errno, ok := sysErr.Err.(syscall.Errno); ok {
if errno == syscall.EADDRINUSE {
return true
}
}
}
}
return false
}