ooni-probe-cli/internal/netxlite/dnsx/encoder_test.go
Simone Basso 3cb782f0a2
refactor(netx): move dns transports in netxlite/dnsx (#503)
While there, modernize the way in which we run tests to avoid
depending on the fake files scattered around the tree and to
use some well defined mock structures instead.

Part of https://github.com/ooni/probe/issues/1591
2021-09-09 21:24:27 +02:00

99 lines
2.5 KiB
Go

package dnsx
import (
"strings"
"testing"
"github.com/miekg/dns"
)
func TestEncoderEncodeA(t *testing.T) {
e := &MiekgEncoder{}
data, err := e.Encode("x.org", dns.TypeA, false)
if err != nil {
t.Fatal(err)
}
validate(t, data, byte(dns.TypeA))
}
func TestEncoderEncodeAAAA(t *testing.T) {
e := &MiekgEncoder{}
data, err := e.Encode("x.org", dns.TypeAAAA, false)
if err != nil {
t.Fatal(err)
}
validate(t, data, byte(dns.TypeA))
}
func validate(t *testing.T, data []byte, qtype byte) {
// skipping over the query ID
if data[2] != 1 {
t.Fatal("FLAGS should only have RD set")
}
if data[3] != 0 {
t.Fatal("RA|Z|Rcode should be zero")
}
if data[4] != 0 || data[5] != 1 {
t.Fatal("QCOUNT high should be one")
}
if data[6] != 0 || data[7] != 0 {
t.Fatal("ANCOUNT should be zero")
}
if data[8] != 0 || data[9] != 0 {
t.Fatal("NSCOUNT should be zero")
}
if data[10] != 0 || data[11] != 0 {
t.Fatal("ARCOUNT should be zero")
}
t.Log(data[12])
if data[12] != 1 || data[13] != byte('x') {
t.Fatal("The name does not contain 1:x")
}
if data[14] != 3 || data[15] != byte('o') || data[16] != byte('r') || data[17] != byte('g') {
t.Fatal("The name does not contain 3:org")
}
if data[18] != 0 {
t.Fatal("The name does not terminate where expected")
}
if data[19] != 0 && data[20] != qtype {
t.Fatal("The query is not for the expected type")
}
if data[21] != 0 && data[22] != 1 {
t.Fatal("The query is not IN")
}
}
func TestEncoderPadding(t *testing.T) {
// The purpose of this unit test is to make sure that for a wide
// array of values we obtain the right query size.
getquerylen := func(domainlen int, padding bool) int {
e := &MiekgEncoder{}
data, err := e.Encode(
// This is not a valid name because it ends up being way
// longer than 255 octets. However, the library is allowing
// us to generate such name and we are not going to send
// it on the wire. Also, we check below that the query that
// we generate is long enough, so we should be good.
dns.Fqdn(strings.Repeat("x.", domainlen)),
dns.TypeA, padding,
)
if err != nil {
t.Fatal(err)
}
return len(data)
}
for domainlen := 1; domainlen <= 4000; domainlen++ {
vanillalen := getquerylen(domainlen, false)
paddedlen := getquerylen(domainlen, true)
if vanillalen < domainlen {
t.Fatal("vanillalen is smaller than domainlen")
}
if (paddedlen % PaddingDesiredBlockSize) != 0 {
t.Fatal("paddedlen is not a multiple of PaddingDesiredBlockSize")
}
if paddedlen < vanillalen {
t.Fatal("paddedlen is smaller than vanillalen")
}
}
}