minio/cmd/net.go
2017-04-11 15:44:27 -07:00

168 lines
4.0 KiB
Go

/*
* 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 cmd
import (
"fmt"
"net"
"os"
"sort"
"strconv"
"syscall"
"github.com/minio/minio-go/pkg/set"
)
// IPv4 addresses of local host.
var localIP4 = mustGetLocalIP4()
// mustSplitHostPort is a wrapper to net.SplitHostPort() where error is assumed to be a fatal.
func mustSplitHostPort(hostPort string) (host, port string) {
host, port, err := net.SplitHostPort(hostPort)
fatalIf(err, "Unable to split host port %s", hostPort)
return host, port
}
// mustGetLocalIP4 returns IPv4 addresses of local host. It panics on error.
func mustGetLocalIP4() (ipList set.StringSet) {
ipList = set.NewStringSet()
addrs, err := net.InterfaceAddrs()
fatalIf(err, "Unable to get IP addresses of this host.")
for _, addr := range addrs {
var ip net.IP
switch v := addr.(type) {
case *net.IPNet:
ip = v.IP
case *net.IPAddr:
ip = v.IP
}
if ip.To4() != nil {
ipList.Add(ip.String())
}
}
return ipList
}
// getHostIP4 returns IPv4 address of given host.
func getHostIP4(host string) (ipList set.StringSet, err error) {
ipList = set.NewStringSet()
ips, err := net.LookupIP(host)
if err != nil {
return ipList, err
}
for _, ip := range ips {
if ip.To4() != nil {
ipList.Add(ip.String())
}
}
return ipList, err
}
func getAPIEndpoints(serverAddr string) (apiEndpoints []string) {
host, port := mustSplitHostPort(serverAddr)
var ipList []string
if host == "" {
ipList = localIP4.ToSlice()
} else {
ipList = []string{host}
}
sort.Strings(ipList)
scheme := httpScheme
if globalIsSSL {
scheme = httpsScheme
}
for _, ip := range ipList {
apiEndpoints = append(apiEndpoints, fmt.Sprintf("%s://%s:%s", scheme, ip, port))
}
return apiEndpoints
}
// 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) (err error) {
// Return true if err is "address already in use" error.
isAddrInUseErr := func(err error) (b bool) {
if opErr, ok := err.(*net.OpError); ok {
if sysErr, ok := opErr.Err.(*os.SyscallError); ok {
if errno, ok := sysErr.Err.(syscall.Errno); ok {
b = (errno == syscall.EADDRINUSE)
}
}
}
return b
}
network := []string{"tcp", "tcp4", "tcp6"}
for _, n := range network {
l, err := net.Listen(n, net.JoinHostPort("", port))
if err == nil {
// As we are able to listen on this network, the port is not in use.
// Close the listener and continue check other networks.
if err = l.Close(); err != nil {
return err
}
} else if isAddrInUseErr(err) {
// As we got EADDRINUSE error, the port is in use by other process.
// Return the error.
return err
}
}
return nil
}
// CheckLocalServerAddr - checks if serverAddr is valid and local host.
func CheckLocalServerAddr(serverAddr string) error {
host, port, err := net.SplitHostPort(serverAddr)
if err != nil {
return err
}
// Check whether port is a valid port number.
p, err := strconv.Atoi(port)
if err != nil {
return fmt.Errorf("invalid port number")
} else if p < 1 || p > 65535 {
return fmt.Errorf("port number must be between 1 to 65535")
}
if host != "" {
hostIPs, err := getHostIP4(host)
if err != nil {
return err
}
if localIP4.Intersection(hostIPs).IsEmpty() {
return fmt.Errorf("host in server address should be this server")
}
}
return nil
}