1 files changed, 83 insertions, 0 deletions
diff --git a/libgo/go/net/dnsconfig_unix_test.go b/libgo/go/net/dnsconfig_unix_test.go
index 9fd6dbf982a..37bdeb04c87 100644
--- a/libgo/go/net/dnsconfig_unix_test.go
+++ b/libgo/go/net/dnsconfig_unix_test.go
@@ -10,6 +10,7 @@ import (
 	"errors"
 	"os"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 )
@@ -61,6 +62,36 @@ var dnsReadConfigTests = []struct {
 		},
 	},
 	{
+		name: "testdata/invalid-ndots-resolv.conf",
+		want: &dnsConfig{
+			servers:  defaultNS,
+			ndots:    0,
+			timeout:  5 * time.Second,
+			attempts: 2,
+			search:   []string{"domain.local."},
+		},
+	},
+	{
+		name: "testdata/large-ndots-resolv.conf",
+		want: &dnsConfig{
+			servers:  defaultNS,
+			ndots:    15,
+			timeout:  5 * time.Second,
+			attempts: 2,
+			search:   []string{"domain.local."},
+		},
+	},
+	{
+		name: "testdata/negative-ndots-resolv.conf",
+		want: &dnsConfig{
+			servers:  defaultNS,
+			ndots:    0,
+			timeout:  5 * time.Second,
+			attempts: 2,
+			search:   []string{"domain.local."},
+		},
+	},
+	{
 		name: "testdata/openbsd-resolv.conf",
 		want: &dnsConfig{
 			ndots:    1,
@@ -154,3 +185,55 @@ func TestDNSDefaultSearch(t *testing.T) {
 		}
 	}
 }
+
+func TestDNSNameLength(t *testing.T) {
+	origGetHostname := getHostname
+	defer func() { getHostname = origGetHostname }()
+	getHostname = func() (string, error) { return "host.domain.local", nil }
+
+	var char63 = ""
+	for i := 0; i < 63; i++ {
+		char63 += "a"
+	}
+	longDomain := strings.Repeat(char63+".", 5) + "example"
+
+	for _, tt := range dnsReadConfigTests {
+		conf := dnsReadConfig(tt.name)
+		if conf.err != nil {
+			t.Fatal(conf.err)
+		}
+
+		var shortestSuffix int
+		for _, suffix := range tt.want.search {
+			if shortestSuffix == 0 || len(suffix) < shortestSuffix {
+				shortestSuffix = len(suffix)
+			}
+		}
+
+		// Test a name that will be maximally long when prefixing the shortest
+		// suffix (accounting for the intervening dot).
+		longName := longDomain[len(longDomain)-254+1+shortestSuffix:]
+		if longName[0] == '.' || longName[1] == '.' {
+			longName = "aa." + longName[3:]
+		}
+		for _, fqdn := range conf.nameList(longName) {
+			if len(fqdn) > 254 {
+				t.Errorf("got %d; want less than or equal to 254", len(fqdn))
+			}
+		}
+
+		// Now test a name that's too long for suffixing.
+		unsuffixable := "a." + longName[1:]
+		unsuffixableResults := conf.nameList(unsuffixable)
+		if len(unsuffixableResults) != 1 {
+			t.Errorf("suffixed names %v; want []", unsuffixableResults[1:])
+		}
+
+		// Now test a name that's too long for DNS.
+		tooLong := "a." + longDomain
+		tooLongResults := conf.nameList(tooLong)
+		if tooLongResults != nil {
+			t.Errorf("suffixed names %v; want nil", tooLongResults)
+		}
+	}
+}