net: make WriteTo fail when UDPConn is already connected

Fixes #2773.

R=rsc
CC=golang-dev
https://golang.org/cl/5571056

diff --git a/src/pkg/net/fd.go b/src/pkg/net/fd.go
index 7ecd135d20645c9ffa87e140336b1008e0756b47..495ef007fe20ea4a2b71efb2bd58f131155fe7ba 100644 (file)
--- a/src/pkg/net/fd.go
+++ b/src/pkg/net/fd.go
@@ -22,15 +22,16 @@ type netFD struct {
        closing bool
 
        // immutable until Close
-       sysfd   int
-       family  int
-       sotype  int
-       sysfile *os.File
-       cr      chan bool
-       cw      chan bool
-       net     string
-       laddr   Addr
-       raddr   Addr
+       sysfd       int
+       family      int
+       sotype      int
+       isConnected bool
+       sysfile     *os.File
+       cr          chan bool
+       cw          chan bool
+       net         string
+       laddr       Addr
+       raddr       Addr
 
        // owned by client
        rdeadline int64

diff --git a/src/pkg/net/fd_windows.go b/src/pkg/net/fd_windows.go
index 6e37b4eb6f1a26e231ab239754c3039a89504536..f00459f0bafe194f2c483429e2d789b6c34cabac 100644 (file)
--- a/src/pkg/net/fd_windows.go
+++ b/src/pkg/net/fd_windows.go
@@ -228,14 +228,15 @@ type netFD struct {
        closing bool
 
        // immutable until Close
-       sysfd   syscall.Handle
-       family  int
-       sotype  int
-       net     string
-       laddr   Addr
-       raddr   Addr
-       resultc [2]chan ioResult // read/write completion results
-       errnoc  [2]chan error    // read/write submit or cancel operation errors
+       sysfd       syscall.Handle
+       family      int
+       sotype      int
+       isConnected bool
+       net         string
+       laddr       Addr
+       raddr       Addr
+       resultc     [2]chan ioResult // read/write completion results
+       errnoc      [2]chan error    // read/write submit or cancel operation errors
 
        // owned by client
        rdeadline int64

diff --git a/src/pkg/net/sock.go b/src/pkg/net/sock.go
index 2f3210b428891c214dd31c002494c5638336b6e6..867e328f12eb419a78d4f65e4d0798e7ab907d1d 100644 (file)
--- a/src/pkg/net/sock.go
+++ b/src/pkg/net/sock.go
@@ -49,6 +49,7 @@ func socket(net string, f, t, p int, la, ra syscall.Sockaddr, toAddr func(syscal
                        fd.Close()
                        return nil, err
                }
+               fd.isConnected = true
        }
 
        sa, _ := syscall.Getsockname(s)

diff --git a/src/pkg/net/udp_test.go b/src/pkg/net/udp_test.go
new file mode 100644 (file)
index 0000000..6ba762b
--- /dev/null
+++ b/src/pkg/net/udp_test.go
@@ -0,0 +1,87 @@
+// 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
+
+import (
+       "runtime"
+       "testing"
+)
+
+func TestWriteToUDP(t *testing.T) {
+       if runtime.GOOS == "plan9" {
+               return
+       }
+
+       l, err := ListenPacket("udp", "127.0.0.1:0")
+       if err != nil {
+               t.Fatalf("Listen failed: %v", err)
+       }
+       defer l.Close()
+
+       testWriteToConn(t, l.LocalAddr().String())
+       testWriteToPacketConn(t, l.LocalAddr().String())
+}
+
+func testWriteToConn(t *testing.T, raddr string) {
+       c, err := Dial("udp", raddr)
+       if err != nil {
+               t.Fatalf("Dial failed: %v", err)
+       }
+       defer c.Close()
+
+       ra, err := ResolveUDPAddr("udp", raddr)
+       if err != nil {
+               t.Fatalf("ResolveUDPAddr failed: %v", err)
+       }
+
+       _, err = c.(*UDPConn).WriteToUDP([]byte("Connection-oriented mode socket"), ra)
+       if err == nil {
+               t.Fatal("WriteToUDP should be failed")
+       }
+       if err != nil && err.(*OpError).Err != ErrWriteToConnected {
+               t.Fatalf("WriteToUDP should be failed as ErrWriteToConnected: %v", err)
+       }
+
+       _, err = c.(*UDPConn).WriteTo([]byte("Connection-oriented mode socket"), ra)
+       if err == nil {
+               t.Fatal("WriteTo should be failed")
+       }
+       if err != nil && err.(*OpError).Err != ErrWriteToConnected {
+               t.Fatalf("WriteTo should be failed as ErrWriteToConnected: %v", err)
+       }
+
+       _, err = c.Write([]byte("Connection-oriented mode socket"))
+       if err != nil {
+               t.Fatalf("Write failed: %v", err)
+       }
+}
+
+func testWriteToPacketConn(t *testing.T, raddr string) {
+       c, err := ListenPacket("udp", "127.0.0.1:0")
+       if err != nil {
+               t.Fatalf("ListenPacket failed: %v", err)
+       }
+       defer c.Close()
+
+       ra, err := ResolveUDPAddr("udp", raddr)
+       if err != nil {
+               t.Fatalf("ResolveUDPAddr failed: %v", err)
+       }
+
+       _, err = c.(*UDPConn).WriteToUDP([]byte("Connection-less mode socket"), ra)
+       if err != nil {
+               t.Fatalf("WriteToUDP failed: %v", err)
+       }
+
+       _, err = c.WriteTo([]byte("Connection-less mode socket"), ra)
+       if err != nil {
+               t.Fatalf("WriteTo failed: %v", err)
+       }
+
+       _, err = c.(*UDPConn).Write([]byte("Connection-less mode socket"))
+       if err == nil {
+               t.Fatal("Write should be failed")
+       }
+}

diff --git a/src/pkg/net/udpsock_posix.go b/src/pkg/net/udpsock_posix.go
index b3a07619e166561a2e6301b5d5352019b217a631..fa3d29adfa8cf21826bf2f81288b25b14a6afafc 100644 (file)
--- a/src/pkg/net/udpsock_posix.go
+++ b/src/pkg/net/udpsock_posix.go
@@ -9,11 +9,14 @@
 package net
 
 import (
+       "errors"
        "os"
        "syscall"
        "time"
 )
 
+var ErrWriteToConnected = errors.New("use of WriteTo with pre-connected UDP")
+
 func sockaddrToUDP(sa syscall.Sockaddr) Addr {
        switch sa := sa.(type) {
        case *syscall.SockaddrInet4:
@@ -182,6 +185,9 @@ func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error) {
        if !c.ok() {
                return 0, os.EINVAL
        }
+       if c.fd.isConnected {
+               return 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
+       }
        sa, err := addr.sockaddr(c.fd.family)
        if err != nil {
                return 0, &OpError{"write", c.fd.net, addr, err}