2020-01-03 00:05:27 +01:00
|
|
|
// Copyright 2012 The Go Authors. All rights reserved.
|
|
|
|
// Use of this source code is governed by a BSD-style
|
|
|
|
// license that can be found in the LICENSE file.
|
|
|
|
|
|
|
|
package net_test
|
|
|
|
|
|
|
|
import (
|
|
|
|
"context"
|
|
|
|
"fmt"
|
|
|
|
"io"
|
|
|
|
"log"
|
|
|
|
"net"
|
|
|
|
"time"
|
|
|
|
)
|
|
|
|
|
|
|
|
func ExampleListener() {
|
|
|
|
// Listen on TCP port 2000 on all available unicast and
|
|
|
|
// anycast IP addresses of the local system.
|
|
|
|
l, err := net.Listen("tcp", ":2000")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
defer l.Close()
|
|
|
|
for {
|
|
|
|
// Wait for a connection.
|
|
|
|
conn, err := l.Accept()
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
// Handle the connection in a new goroutine.
|
|
|
|
// The loop then returns to accepting, so that
|
|
|
|
// multiple connections may be served concurrently.
|
|
|
|
go func(c net.Conn) {
|
|
|
|
// Echo all incoming data.
|
|
|
|
io.Copy(c, c)
|
|
|
|
// Shut down the connection.
|
|
|
|
c.Close()
|
|
|
|
}(conn)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleDialer() {
|
|
|
|
var d net.Dialer
|
|
|
|
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
|
|
|
|
defer cancel()
|
|
|
|
|
|
|
|
conn, err := d.DialContext(ctx, "tcp", "localhost:12345")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatalf("Failed to dial: %v", err)
|
|
|
|
}
|
|
|
|
defer conn.Close()
|
|
|
|
|
|
|
|
if _, err := conn.Write([]byte("Hello, World!")); err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
}
|
2020-12-23 18:57:37 +01:00
|
|
|
|
|
|
|
func ExampleDialer_unix() {
|
|
|
|
// DialUnix does not take a context.Context parameter. This example shows
|
|
|
|
// how to dial a Unix socket with a Context. Note that the Context only
|
|
|
|
// applies to the dial operation; it does not apply to the connection once
|
|
|
|
// it has been established.
|
|
|
|
var d net.Dialer
|
|
|
|
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
|
|
|
|
defer cancel()
|
|
|
|
|
|
|
|
d.LocalAddr = nil // if you have a local addr, add it here
|
|
|
|
raddr := net.UnixAddr{Name: "/path/to/unix.sock", Net: "unix"}
|
|
|
|
conn, err := d.DialContext(ctx, "unix", raddr.String())
|
|
|
|
if err != nil {
|
|
|
|
log.Fatalf("Failed to dial: %v", err)
|
|
|
|
}
|
|
|
|
defer conn.Close()
|
|
|
|
if _, err := conn.Write([]byte("Hello, socket!")); err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
}
|
2020-01-03 00:05:27 +01:00
|
|
|
|
|
|
|
func ExampleIPv4() {
|
|
|
|
fmt.Println(net.IPv4(8, 8, 8, 8))
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// 8.8.8.8
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleParseCIDR() {
|
|
|
|
ipv4Addr, ipv4Net, err := net.ParseCIDR("192.0.2.1/24")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
fmt.Println(ipv4Addr)
|
|
|
|
fmt.Println(ipv4Net)
|
|
|
|
|
|
|
|
ipv6Addr, ipv6Net, err := net.ParseCIDR("2001:db8:a0b:12f0::1/32")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
fmt.Println(ipv6Addr)
|
|
|
|
fmt.Println(ipv6Net)
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// 192.0.2.1
|
|
|
|
// 192.0.2.0/24
|
|
|
|
// 2001:db8:a0b:12f0::1
|
|
|
|
// 2001:db8::/32
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleParseIP() {
|
|
|
|
fmt.Println(net.ParseIP("192.0.2.1"))
|
|
|
|
fmt.Println(net.ParseIP("2001:db8::68"))
|
|
|
|
fmt.Println(net.ParseIP("192.0.2"))
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// 192.0.2.1
|
|
|
|
// 2001:db8::68
|
|
|
|
// <nil>
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleIP_DefaultMask() {
|
|
|
|
ip := net.ParseIP("192.0.2.1")
|
|
|
|
fmt.Println(ip.DefaultMask())
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// ffffff00
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleIP_Mask() {
|
|
|
|
ipv4Addr := net.ParseIP("192.0.2.1")
|
|
|
|
// This mask corresponds to a /24 subnet for IPv4.
|
|
|
|
ipv4Mask := net.CIDRMask(24, 32)
|
|
|
|
fmt.Println(ipv4Addr.Mask(ipv4Mask))
|
|
|
|
|
|
|
|
ipv6Addr := net.ParseIP("2001:db8:a0b:12f0::1")
|
|
|
|
// This mask corresponds to a /32 subnet for IPv6.
|
|
|
|
ipv6Mask := net.CIDRMask(32, 128)
|
|
|
|
fmt.Println(ipv6Addr.Mask(ipv6Mask))
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// 192.0.2.0
|
|
|
|
// 2001:db8::
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleCIDRMask() {
|
|
|
|
// This mask corresponds to a /31 subnet for IPv4.
|
|
|
|
fmt.Println(net.CIDRMask(31, 32))
|
|
|
|
|
|
|
|
// This mask corresponds to a /64 subnet for IPv6.
|
|
|
|
fmt.Println(net.CIDRMask(64, 128))
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// fffffffe
|
|
|
|
// ffffffffffffffff0000000000000000
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleIPv4Mask() {
|
|
|
|
fmt.Println(net.IPv4Mask(255, 255, 255, 0))
|
|
|
|
|
|
|
|
// Output:
|
|
|
|
// ffffff00
|
|
|
|
}
|
|
|
|
|
|
|
|
func ExampleUDPConn_WriteTo() {
|
|
|
|
// Unlike Dial, ListenPacket creates a connection without any
|
|
|
|
// association with peers.
|
|
|
|
conn, err := net.ListenPacket("udp", ":0")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
defer conn.Close()
|
|
|
|
|
|
|
|
dst, err := net.ResolveUDPAddr("udp", "192.0.2.1:2000")
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
|
|
|
|
// The connection can write data to the desired address.
|
|
|
|
_, err = conn.WriteTo([]byte("data"), dst)
|
|
|
|
if err != nil {
|
|
|
|
log.Fatal(err)
|
|
|
|
}
|
|
|
|
}
|