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Copy pathlistener.go
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203 lines (174 loc) · 5.46 KB
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/*
* MinIO Cloud Storage, (C) 2017 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 http
import (
"fmt"
"io"
"net"
"os"
"sync"
"syscall"
)
type acceptResult struct {
conn net.Conn
err error
}
// httpListener - HTTP listener capable of handling multiple server addresses.
type httpListener struct {
mutex sync.Mutex // to guard Close() method.
tcpListeners []*net.TCPListener // underlaying TCP listeners.
acceptCh chan acceptResult // channel where all TCP listeners write accepted connection.
doneCh chan struct{} // done channel for TCP listener goroutines.
}
// isRoutineNetErr returns true if error is due to a network timeout,
// connect reset or io.EOF and false otherwise
func isRoutineNetErr(err error) bool {
if err == nil {
return false
}
if nErr, ok := err.(*net.OpError); ok {
// Check if the error is a tcp connection reset
if syscallErr, ok := nErr.Err.(*os.SyscallError); ok {
if errno, ok := syscallErr.Err.(syscall.Errno); ok {
return errno == syscall.ECONNRESET
}
}
// Check if the error is a timeout
return nErr.Timeout()
}
// check for io.EOF and also some times io.EOF is wrapped is another error type.
return err == io.EOF || err.Error() == "EOF"
}
// start - starts separate goroutine for each TCP listener. A valid new connection is passed to httpListener.acceptCh.
func (listener *httpListener) start() {
listener.acceptCh = make(chan acceptResult)
listener.doneCh = make(chan struct{})
// Closure to send acceptResult to acceptCh.
// It returns true if the result is sent else false if returns when doneCh is closed.
send := func(result acceptResult, doneCh <-chan struct{}) bool {
select {
case listener.acceptCh <- result:
// Successfully written to acceptCh
return true
case <-doneCh:
// As stop signal is received, close accepted connection.
if result.conn != nil {
result.conn.Close()
}
return false
}
}
// Closure to handle single connection.
handleConn := func(tcpConn *net.TCPConn, doneCh <-chan struct{}) {
tcpConn.SetKeepAlive(true)
send(acceptResult{tcpConn, nil}, doneCh)
}
// Closure to handle TCPListener until done channel is closed.
handleListener := func(tcpListener *net.TCPListener, doneCh <-chan struct{}) {
for {
tcpConn, err := tcpListener.AcceptTCP()
if err != nil {
// Returns when send fails.
if !send(acceptResult{nil, err}, doneCh) {
return
}
} else {
go handleConn(tcpConn, doneCh)
}
}
}
// Start separate goroutine for each TCP listener to handle connection.
for _, tcpListener := range listener.tcpListeners {
go handleListener(tcpListener, listener.doneCh)
}
}
// Accept - reads from httpListener.acceptCh for one of previously accepted TCP connection and returns the same.
func (listener *httpListener) Accept() (conn net.Conn, err error) {
result, ok := <-listener.acceptCh
if ok {
return result.conn, result.err
}
return nil, syscall.EINVAL
}
// Close - closes underneath all TCP listeners.
func (listener *httpListener) Close() (err error) {
listener.mutex.Lock()
defer listener.mutex.Unlock()
if listener.doneCh == nil {
return syscall.EINVAL
}
for i := range listener.tcpListeners {
listener.tcpListeners[i].Close()
}
close(listener.doneCh)
listener.doneCh = nil
return nil
}
// Addr - net.Listener interface compatible method returns net.Addr. In case of multiple TCP listeners, it returns '0.0.0.0' as IP address.
func (listener *httpListener) Addr() (addr net.Addr) {
addr = listener.tcpListeners[0].Addr()
if len(listener.tcpListeners) == 1 {
return addr
}
tcpAddr := addr.(*net.TCPAddr)
if ip := net.ParseIP("0.0.0.0"); ip != nil {
tcpAddr.IP = ip
}
addr = tcpAddr
return addr
}
// Addrs - returns all address information of TCP listeners.
func (listener *httpListener) Addrs() (addrs []net.Addr) {
for i := range listener.tcpListeners {
addrs = append(addrs, listener.tcpListeners[i].Addr())
}
return addrs
}
// newHTTPListener - creates new httpListener object which is interface compatible to net.Listener.
// httpListener is capable to
// * listen to multiple addresses
// * controls incoming connections only doing HTTP protocol
func newHTTPListener(serverAddrs []string) (listener *httpListener, err error) {
var tcpListeners []*net.TCPListener
// Close all opened listeners on error
defer func() {
if err == nil {
return
}
for _, tcpListener := range tcpListeners {
// Ignore error on close.
tcpListener.Close()
}
}()
for _, serverAddr := range serverAddrs {
var l net.Listener
if l, err = listen("tcp", serverAddr); err != nil {
if l, err = fallbackListen("tcp", serverAddr); err != nil {
return nil, err
}
}
tcpListener, ok := l.(*net.TCPListener)
if !ok {
return nil, fmt.Errorf("unexpected listener type found %v, expected net.TCPListener", l)
}
tcpListeners = append(tcpListeners, tcpListener)
}
listener = &httpListener{
tcpListeners: tcpListeners,
}
listener.start()
return listener, nil
}