libgo/go/net/dnsmsg_test.go

   1 // Copyright 2011 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 package net
   6
   7 import (
   8         "encoding/hex"
   9         "reflect"
  10         "testing"
  11 )
  12
  13 func TestDNSParseSRVReply(t *testing.T) {
  14         data, err := hex.DecodeString(dnsSRVReply)
  15         if err != nil {
  16                 t.Fatal(err)
  17         }
  18         msg := new(dnsMsg)
  19         ok := msg.Unpack(data)
  20         if !ok {
  21                 t.Fatalf("unpacking packet failed")
  22         }
  23         msg.String() // exercise this code path
  24         if g, e := len(msg.answer), 5; g != e {
  25                 t.Errorf("len(msg.answer) = %d; want %d", g, e)
  26         }
  27         for idx, rr := range msg.answer {
  28                 if g, e := rr.Header().Rrtype, uint16(dnsTypeSRV); g != e {
  29                         t.Errorf("rr[%d].Header().Rrtype = %d; want %d", idx, g, e)
  30                 }
  31                 if _, ok := rr.(*dnsRR_SRV); !ok {
  32                         t.Errorf("answer[%d] = %T; want *dnsRR_SRV", idx, rr)
  33                 }
  34         }
  35         _, addrs, err := answer("_xmpp-server._tcp.google.com.", "foo:53", msg, uint16(dnsTypeSRV))
  36         if err != nil {
  37                 t.Fatalf("answer: %v", err)
  38         }
  39         if g, e := len(addrs), 5; g != e {
  40                 t.Errorf("len(addrs) = %d; want %d", g, e)
  41                 t.Logf("addrs = %#v", addrs)
  42         }
  43         // repack and unpack.
  44         data2, ok := msg.Pack()
  45         msg2 := new(dnsMsg)
  46         msg2.Unpack(data2)
  47         switch {
  48         case !ok:
  49                 t.Errorf("failed to repack message")
  50         case !reflect.DeepEqual(msg, msg2):
  51                 t.Errorf("repacked message differs from original")
  52         }
  53 }
  54
  55 func TestDNSParseCorruptSRVReply(t *testing.T) {
  56         data, err := hex.DecodeString(dnsSRVCorruptReply)
  57         if err != nil {
  58                 t.Fatal(err)
  59         }
  60         msg := new(dnsMsg)
  61         ok := msg.Unpack(data)
  62         if !ok {
  63                 t.Fatalf("unpacking packet failed")
  64         }
  65         msg.String() // exercise this code path
  66         if g, e := len(msg.answer), 5; g != e {
  67                 t.Errorf("len(msg.answer) = %d; want %d", g, e)
  68         }
  69         for idx, rr := range msg.answer {
  70                 if g, e := rr.Header().Rrtype, uint16(dnsTypeSRV); g != e {
  71                         t.Errorf("rr[%d].Header().Rrtype = %d; want %d", idx, g, e)
  72                 }
  73                 if idx == 4 {
  74                         if _, ok := rr.(*dnsRR_Header); !ok {
  75                                 t.Errorf("answer[%d] = %T; want *dnsRR_Header", idx, rr)
  76                         }
  77                 } else {
  78                         if _, ok := rr.(*dnsRR_SRV); !ok {
  79                                 t.Errorf("answer[%d] = %T; want *dnsRR_SRV", idx, rr)
  80                         }
  81                 }
  82         }
  83         _, addrs, err := answer("_xmpp-server._tcp.google.com.", "foo:53", msg, uint16(dnsTypeSRV))
  84         if err != nil {
  85                 t.Fatalf("answer: %v", err)
  86         }
  87         if g, e := len(addrs), 4; g != e {
  88                 t.Errorf("len(addrs) = %d; want %d", g, e)
  89                 t.Logf("addrs = %#v", addrs)
  90         }
  91 }
  92
  93 // Valid DNS SRV reply
  94 const dnsSRVReply = "0901818000010005000000000c5f786d70702d736572766572045f74637006676f6f67" +
  95         "6c6503636f6d0000210001c00c002100010000012c00210014000014950c786d70702d" +
  96         "73657276657234016c06676f6f676c6503636f6d00c00c002100010000012c00210014" +
  97         "000014950c786d70702d73657276657232016c06676f6f676c6503636f6d00c00c0021" +
  98         "00010000012c00210014000014950c786d70702d73657276657233016c06676f6f676c" +
  99         "6503636f6d00c00c002100010000012c00200005000014950b786d70702d7365727665" +
 100         "72016c06676f6f676c6503636f6d00c00c002100010000012c00210014000014950c78" +
 101         "6d70702d73657276657231016c06676f6f676c6503636f6d00"
 102
 103 // Corrupt DNS SRV reply, with its final RR having a bogus length
 104 // (perhaps it was truncated, or it's malicious) The mutation is the
 105 // capital "FF" below, instead of the proper "21".
 106 const dnsSRVCorruptReply = "0901818000010005000000000c5f786d70702d736572766572045f74637006676f6f67" +
 107         "6c6503636f6d0000210001c00c002100010000012c00210014000014950c786d70702d" +
 108         "73657276657234016c06676f6f676c6503636f6d00c00c002100010000012c00210014" +
 109         "000014950c786d70702d73657276657232016c06676f6f676c6503636f6d00c00c0021" +
 110         "00010000012c00210014000014950c786d70702d73657276657233016c06676f6f676c" +
 111         "6503636f6d00c00c002100010000012c00200005000014950b786d70702d7365727665" +
 112         "72016c06676f6f676c6503636f6d00c00c002100010000012c00FF0014000014950c78" +
 113         "6d70702d73657276657231016c06676f6f676c6503636f6d00"