...
Run Format

Source file src/net/dnsclient_test.go

Documentation: net

  // Copyright 2014 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 (
  	"math/rand"
  	"testing"
  )
  
  func checkDistribution(t *testing.T, data []*SRV, margin float64) {
  	sum := 0
  	for _, srv := range data {
  		sum += int(srv.Weight)
  	}
  
  	results := make(map[string]int)
  
  	count := 1000
  	for j := 0; j < count; j++ {
  		d := make([]*SRV, len(data))
  		copy(d, data)
  		byPriorityWeight(d).shuffleByWeight()
  		key := d[0].Target
  		results[key] = results[key] + 1
  	}
  
  	actual := results[data[0].Target]
  	expected := float64(count) * float64(data[0].Weight) / float64(sum)
  	diff := float64(actual) - expected
  	t.Logf("actual: %v diff: %v e: %v m: %v", actual, diff, expected, margin)
  	if diff < 0 {
  		diff = -diff
  	}
  	if diff > (expected * margin) {
  		t.Errorf("missed target weight: expected %v, %v", expected, actual)
  	}
  }
  
  func testUniformity(t *testing.T, size int, margin float64) {
  	rand.Seed(1)
  	data := make([]*SRV, size)
  	for i := 0; i < size; i++ {
  		data[i] = &SRV{Target: string('a' + i), Weight: 1}
  	}
  	checkDistribution(t, data, margin)
  }
  
  func TestDNSSRVUniformity(t *testing.T) {
  	testUniformity(t, 2, 0.05)
  	testUniformity(t, 3, 0.10)
  	testUniformity(t, 10, 0.20)
  	testWeighting(t, 0.05)
  }
  
  func testWeighting(t *testing.T, margin float64) {
  	rand.Seed(1)
  	data := []*SRV{
  		{Target: "a", Weight: 60},
  		{Target: "b", Weight: 30},
  		{Target: "c", Weight: 10},
  	}
  	checkDistribution(t, data, margin)
  }
  
  func TestWeighting(t *testing.T) {
  	testWeighting(t, 0.05)
  }
  
  // Issue 8434: verify that Temporary returns true on an error when rcode
  // is SERVFAIL
  func TestIssue8434(t *testing.T) {
  	msg := &dnsMsg{
  		dnsMsgHdr: dnsMsgHdr{
  			rcode: dnsRcodeServerFailure,
  		},
  	}
  
  	_, _, err := answer("golang.org", "foo:53", msg, uint16(dnsTypeSRV))
  	if err == nil {
  		t.Fatal("expected an error")
  	}
  	if ne, ok := err.(Error); !ok {
  		t.Fatalf("err = %#v; wanted something supporting net.Error", err)
  	} else if !ne.Temporary() {
  		t.Fatalf("Temporary = false for err = %#v; want Temporary == true", err)
  	}
  	if de, ok := err.(*DNSError); !ok {
  		t.Fatalf("err = %#v; wanted a *net.DNSError", err)
  	} else if !de.IsTemporary {
  		t.Fatalf("IsTemporary = false for err = %#v; want IsTemporary == true", err)
  	}
  }
  
  // Issue 12778: verify that NXDOMAIN without RA bit errors as
  // "no such host" and not "server misbehaving"
  func TestIssue12778(t *testing.T) {
  	msg := &dnsMsg{
  		dnsMsgHdr: dnsMsgHdr{
  			rcode:               dnsRcodeNameError,
  			recursion_available: false,
  		},
  	}
  
  	_, _, err := answer("golang.org", "foo:53", msg, uint16(dnsTypeSRV))
  	if err == nil {
  		t.Fatal("expected an error")
  	}
  	de, ok := err.(*DNSError)
  	if !ok {
  		t.Fatalf("err = %#v; wanted a *net.DNSError", err)
  	}
  	if de.Err != errNoSuchHost.Error() {
  		t.Fatalf("Err = %#v; wanted %q", de.Err, errNoSuchHost.Error())
  	}
  }
  

View as plain text