libgo/go/syscall/creds_test.go

   1 // Copyright 2012 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build linux
   6
   7 package syscall_test
   8
   9 import (
  10         "bytes"
  11         "net"
  12         "os"
  13         "syscall"
  14         "testing"
  15 )
  16
  17 // TestSCMCredentials tests the sending and receiving of credentials
  18 // (PID, UID, GID) in an ancillary message between two UNIX
  19 // sockets. The SO_PASSCRED socket option is enabled on the sending
  20 // socket for this to work.
  21 func TestSCMCredentials(t *testing.T) {
  22         fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM, 0)
  23         if err != nil {
  24                 t.Fatalf("Socketpair: %v", err)
  25         }
  26         defer syscall.Close(fds[0])
  27         defer syscall.Close(fds[1])
  28
  29         err = syscall.SetsockoptInt(fds[0], syscall.SOL_SOCKET, syscall.SO_PASSCRED, 1)
  30         if err != nil {
  31                 t.Fatalf("SetsockoptInt: %v", err)
  32         }
  33
  34         srvFile := os.NewFile(uintptr(fds[0]), "server")
  35         defer srvFile.Close()
  36         srv, err := net.FileConn(srvFile)
  37         if err != nil {
  38                 t.Errorf("FileConn: %v", err)
  39                 return
  40         }
  41         defer srv.Close()
  42
  43         cliFile := os.NewFile(uintptr(fds[1]), "client")
  44         defer cliFile.Close()
  45         cli, err := net.FileConn(cliFile)
  46         if err != nil {
  47                 t.Errorf("FileConn: %v", err)
  48                 return
  49         }
  50         defer cli.Close()
  51
  52         var ucred syscall.Ucred
  53         if os.Getuid() != 0 {
  54                 ucred.Pid = int32(os.Getpid())
  55                 ucred.Uid = 0
  56                 ucred.Gid = 0
  57                 oob := syscall.UnixCredentials(&ucred)
  58                 _, _, err := cli.(*net.UnixConn).WriteMsgUnix(nil, oob, nil)
  59                 if op, ok := err.(*net.OpError); ok {
  60                         err = op.Err
  61                 }
  62                 if sys, ok := err.(*os.SyscallError); ok {
  63                         err = sys.Err
  64                 }
  65                 if err != syscall.EPERM {
  66                         t.Fatalf("WriteMsgUnix failed with %v, want EPERM", err)
  67                 }
  68         }
  69
  70         ucred.Pid = int32(os.Getpid())
  71         ucred.Uid = uint32(os.Getuid())
  72         ucred.Gid = uint32(os.Getgid())
  73         oob := syscall.UnixCredentials(&ucred)
  74
  75         // this is going to send a dummy byte
  76         n, oobn, err := cli.(*net.UnixConn).WriteMsgUnix(nil, oob, nil)
  77         if err != nil {
  78                 t.Fatalf("WriteMsgUnix: %v", err)
  79         }
  80         if n != 0 {
  81                 t.Fatalf("WriteMsgUnix n = %d, want 0", n)
  82         }
  83         if oobn != len(oob) {
  84                 t.Fatalf("WriteMsgUnix oobn = %d, want %d", oobn, len(oob))
  85         }
  86
  87         oob2 := make([]byte, 10*len(oob))
  88         n, oobn2, flags, _, err := srv.(*net.UnixConn).ReadMsgUnix(nil, oob2)
  89         if err != nil {
  90                 t.Fatalf("ReadMsgUnix: %v", err)
  91         }
  92         if flags != 0 {
  93                 t.Fatalf("ReadMsgUnix flags = 0x%x, want 0", flags)
  94         }
  95         if n != 1 {
  96                 t.Fatalf("ReadMsgUnix n = %d, want 1 (dummy byte)", n)
  97         }
  98         if oobn2 != oobn {
  99                 // without SO_PASSCRED set on the socket, ReadMsgUnix will
 100                 // return zero oob bytes
 101                 t.Fatalf("ReadMsgUnix oobn = %d, want %d", oobn2, oobn)
 102         }
 103         oob2 = oob2[:oobn2]
 104         if !bytes.Equal(oob, oob2) {
 105                 t.Fatal("ReadMsgUnix oob bytes don't match")
 106         }
 107
 108         scm, err := syscall.ParseSocketControlMessage(oob2)
 109         if err != nil {
 110                 t.Fatalf("ParseSocketControlMessage: %v", err)
 111         }
 112         newUcred, err := syscall.ParseUnixCredentials(&scm[0])
 113         if err != nil {
 114                 t.Fatalf("ParseUnixCredentials: %v", err)
 115         }
 116         if *newUcred != ucred {
 117                 t.Fatalf("ParseUnixCredentials = %+v, want %+v", newUcred, ucred)
 118         }
 119 }