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plugin/cache: key cache on Checking Disabled (CD) bit (#6354)

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* plugin/cache: key cache on Checking Disabled (CD) bit

Key the cache on CD bit, which effectively separates the entries for
queries with CD disabled or enabled.

Signed-off-by: Grant Spence <gspence@redhat.com>
This commit is contained in:
Grant Spence 2023-11-10 07:00:47 -08:00 • committed by GitHub
parent 42d0c75d04
commit 997c7f9539
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 520 additions and 287 deletions
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16
plugin/cache/cache.go vendored
View file

@ -79,7 +79,7 @@ func New() *Cache {
// key returns key under which we store the item, -1 will be returned if we don't store the message. // key returns key under which we store the item, -1 will be returned if we don't store the message.
// Currently we do not cache Truncated, errors zone transfers or dynamic update messages. // Currently we do not cache Truncated, errors zone transfers or dynamic update messages.
// qname holds the already lowercased qname. // qname holds the already lowercased qname.
func key(qname string, m *dns.Msg, t response.Type, do bool) (bool, uint64) { func key(qname string, m *dns.Msg, t response.Type, do, cd bool) (bool, uint64) {
// We don't store truncated responses. // We don't store truncated responses.
if m.Truncated { if m.Truncated {
return false, 0 return false, 0
@ -89,13 +89,13 @@ func key(qname string, m *dns.Msg, t response.Type, do bool) (bool, uint64) {
return false, 0 return false, 0
} }
return true, hash(qname, m.Question[0].Qtype, do) return true, hash(qname, m.Question[0].Qtype, do, cd)
} }
var one = []byte("1") var one = []byte("1")
var zero = []byte("0") var zero = []byte("0")
func hash(qname string, qtype uint16, do bool) uint64 { func hash(qname string, qtype uint16, do, cd bool) uint64 {
h := fnv.New64() h := fnv.New64()
if do { if do {
@ -104,6 +104,12 @@ func hash(qname string, qtype uint16, do bool) uint64 {
h.Write(zero) h.Write(zero)
} }
if cd {
h.Write(one)
} else {
h.Write(zero)
}
h.Write([]byte{byte(qtype >> 8)}) h.Write([]byte{byte(qtype >> 8)})
h.Write([]byte{byte(qtype)}) h.Write([]byte{byte(qtype)})
h.Write([]byte(qname)) h.Write([]byte(qname))
@ -129,6 +135,7 @@ type ResponseWriter struct {
server string // Server handling the request. server string // Server handling the request.
do bool // When true the original request had the DO bit set. do bool // When true the original request had the DO bit set.
cd bool // When true the original request had the CD bit set.
ad bool // When true the original request had the AD bit set. ad bool // When true the original request had the AD bit set.
prefetch bool // When true write nothing back to the client. prefetch bool // When true write nothing back to the client.
remoteAddr net.Addr remoteAddr net.Addr
@ -159,6 +166,7 @@ func newPrefetchResponseWriter(server string, state request.Request, c *Cache) *
state: state, state: state,
server: server, server: server,
do: state.Do(), do: state.Do(),
cd: state.Req.CheckingDisabled,
prefetch: true, prefetch: true,
remoteAddr: addr, remoteAddr: addr,
} }
@ -177,7 +185,7 @@ func (w *ResponseWriter) WriteMsg(res *dns.Msg) error {
mt, _ := response.Typify(res, w.now().UTC()) mt, _ := response.Typify(res, w.now().UTC())
// key returns empty string for anything we don't want to cache. // key returns empty string for anything we don't want to cache.
hasKey, key := key(w.state.Name(), res, mt, w.do) hasKey, key := key(w.state.Name(), res, mt, w.do, w.cd)
msgTTL := dnsutil.MinimalTTL(res, mt) msgTTL := dnsutil.MinimalTTL(res, mt)
var duration time.Duration var duration time.Duration

677
plugin/cache/cache_test.go vendored
View file

@ -16,230 +16,15 @@ import (
"github.com/miekg/dns" "github.com/miekg/dns"
) )
type cacheTestCase struct { func cacheMsg(m *dns.Msg, tc test.Case) *dns.Msg {
test.Case // the expected message coming "out" of cache
in test.Case // the test message going "in" to cache
AuthenticatedData bool
RecursionAvailable bool
Truncated bool
shouldCache bool
}
var cacheTestCases = []cacheTestCase{
{
// Test with Authenticated Data bit
RecursionAvailable: true, AuthenticatedData: true,
Case: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
},
},
in: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3601 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3601 IN MX 10 aspmx2.googlemail.com."),
},
},
shouldCache: true,
},
{
// Test case sensitivity
RecursionAvailable: true, AuthenticatedData: true,
Case: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
},
},
in: test.Case{
Qname: "mIEK.nL.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3601 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3601 IN MX 10 aspmx2.googlemail.com."),
},
},
shouldCache: true,
},
{
// Test truncated responses don't get cached
Truncated: true,
Case: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{test.MX("miek.nl. 1800 IN MX 1 aspmx.l.google.com.")},
},
in: test.Case{},
shouldCache: false,
},
{
// Test dns.RcodeNameError cache
RecursionAvailable: true,
Case: test.Case{
Rcode: dns.RcodeNameError,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
shouldCache: true,
},
{
// Test dns.RcodeServerFailure cache
RecursionAvailable: true,
Case: test.Case{
Rcode: dns.RcodeServerFailure,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
},
in: test.Case{
Rcode: dns.RcodeServerFailure,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
},
shouldCache: true,
},
{
// Test dns.RcodeNotImplemented cache
RecursionAvailable: true,
Case: test.Case{
Rcode: dns.RcodeNotImplemented,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
},
in: test.Case{
Rcode: dns.RcodeNotImplemented,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
},
shouldCache: true,
},
{
// Test cache has separate items for query DO Bit value
// This doesn't cache because this RRSIG is expired and previous tests used DO Bit false
RecursionAvailable: true,
Case: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("miek.nl. 3600 IN RRSIG MX 8 2 1800 20160521031301 20160421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
},
in: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("miek.nl. 1800 IN RRSIG MX 8 2 1800 20160521031301 20160421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
},
shouldCache: false,
},
{
// Test DO Bit with a RRSIG that is not expired
RecursionAvailable: true,
Case: test.Case{
Qname: "example.org.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("example.org. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("example.org. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("example.org. 3600 IN RRSIG MX 8 2 1800 20170521031301 20170421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
},
in: test.Case{
Qname: "example.org.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("example.org. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("example.org. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("example.org. 1800 IN RRSIG MX 8 2 1800 20170521031301 20170421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
},
shouldCache: true,
},
{
// Test negative zone exception
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
Case: test.Case{},
shouldCache: false,
},
{
// Test positive zone exception
in: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("pos-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
Case: test.Case{},
shouldCache: false,
},
{
// Test positive zone exception with negative answer
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
Case: test.Case{
Rcode: dns.RcodeNameError,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
shouldCache: true,
},
{
// Test negative zone exception with positive answer
in: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("neg-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
Case: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("neg-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
shouldCache: true,
},
}
func cacheMsg(m *dns.Msg, tc cacheTestCase) *dns.Msg {
m.RecursionAvailable = tc.RecursionAvailable m.RecursionAvailable = tc.RecursionAvailable
m.AuthenticatedData = tc.AuthenticatedData m.AuthenticatedData = tc.AuthenticatedData
m.Authoritative = true m.CheckingDisabled = tc.CheckingDisabled
m.Authoritative = tc.Authoritative
m.Rcode = tc.Rcode m.Rcode = tc.Rcode
m.Truncated = tc.Truncated m.Truncated = tc.Truncated
m.Answer = tc.in.Answer m.Answer = tc.Answer
m.Ns = tc.in.Ns m.Ns = tc.Ns
// m.Extra = tc.in.Extra don't copy Extra, because we don't care and fake EDNS0 DO with tc.Do. // m.Extra = tc.in.Extra don't copy Extra, because we don't care and fake EDNS0 DO with tc.Do.
return m return m
} }
@ -256,57 +41,305 @@ func newTestCache(ttl time.Duration) (*Cache, *ResponseWriter) {
return c, crr return c, crr
} }
func TestCache(t *testing.T) { // TestCacheInsertion verifies the insertion of items to the cache.
func TestCacheInsertion(t *testing.T) {
cacheTestCases := []struct {
name string
out test.Case // the expected message coming "out" of cache
in test.Case // the test message going "in" to cache
shouldCache bool
}{
{
name: "test ad bit cache",
out: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
},
RecursionAvailable: true,
AuthenticatedData: true,
},
in: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3601 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3601 IN MX 10 aspmx2.googlemail.com."),
},
RecursionAvailable: true,
AuthenticatedData: true,
},
shouldCache: true,
},
{
name: "test case sensitivity cache",
out: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
},
RecursionAvailable: true,
AuthenticatedData: true,
},
in: test.Case{
Qname: "mIEK.nL.", Qtype: dns.TypeMX,
Answer: []dns.RR{
test.MX("miek.nl. 3601 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3601 IN MX 10 aspmx2.googlemail.com."),
},
RecursionAvailable: true,
AuthenticatedData: true,
},
shouldCache: true,
},
{
name: "test truncated responses shouldn't cache",
in: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Answer: []dns.RR{test.MX("miek.nl. 1800 IN MX 1 aspmx.l.google.com.")},
Truncated: true,
},
shouldCache: false,
},
{
name: "test dns.RcodeNameError cache",
out: test.Case{
Rcode: dns.RcodeNameError,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
RecursionAvailable: true,
},
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
RecursionAvailable: true,
},
shouldCache: true,
},
{
name: "test dns.RcodeServerFailure cache",
out: test.Case{
Rcode: dns.RcodeServerFailure,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
RecursionAvailable: true,
},
in: test.Case{
Rcode: dns.RcodeServerFailure,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
RecursionAvailable: true,
},
shouldCache: true,
},
{
name: "test dns.RcodeNotImplemented cache",
out: test.Case{
Rcode: dns.RcodeNotImplemented,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
RecursionAvailable: true,
},
in: test.Case{
Rcode: dns.RcodeNotImplemented,
Qname: "example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{},
RecursionAvailable: true,
},
shouldCache: true,
},
{
name: "test expired RRSIG doesn't cache",
in: test.Case{
Qname: "miek.nl.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("miek.nl. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("miek.nl. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("miek.nl. 1800 IN RRSIG MX 8 2 1800 20160521031301 20160421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
RecursionAvailable: true,
},
shouldCache: false,
},
{
name: "test DO bit with RRSIG not expired cache",
out: test.Case{
Qname: "example.org.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("example.org. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("example.org. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("example.org. 3600 IN RRSIG MX 8 2 1800 20170521031301 20170421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
RecursionAvailable: true,
},
in: test.Case{
Qname: "example.org.", Qtype: dns.TypeMX,
Do: true,
Answer: []dns.RR{
test.MX("example.org. 3600 IN MX 1 aspmx.l.google.com."),
test.MX("example.org. 3600 IN MX 10 aspmx2.googlemail.com."),
test.RRSIG("example.org. 1800 IN RRSIG MX 8 2 1800 20170521031301 20170421031301 12051 miek.nl. lAaEzB5teQLLKyDenatmyhca7blLRg9DoGNrhe3NReBZN5C5/pMQk8Jc u25hv2fW23/SLm5IC2zaDpp2Fzgm6Jf7e90/yLcwQPuE7JjS55WMF+HE LEh7Z6AEb+Iq4BWmNhUz6gPxD4d9eRMs7EAzk13o1NYi5/JhfL6IlaYy qkc="),
},
RecursionAvailable: true,
},
shouldCache: true,
},
{
name: "test CD bit cache",
out: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "dnssec-failed.org.",
Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("dnssec-failed.org. 3600 IN A 127.0.0.1"),
},
CheckingDisabled: true,
},
in: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "dnssec-failed.org.",
Answer: []dns.RR{
test.A("dnssec-failed.org. 3600 IN A 127.0.0.1"),
},
Qtype: dns.TypeA,
CheckingDisabled: true,
},
shouldCache: true,
},
{
name: "test negative zone exception shouldn't cache",
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
shouldCache: false,
},
{
name: "test positive zone exception shouldn't cache",
in: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("pos-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
shouldCache: false,
},
{
name: "test positive zone exception with negative answer cache",
in: test.Case{
Rcode: dns.RcodeNameError,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
out: test.Case{
Rcode: dns.RcodeNameError,
Qname: "pos-disabled.example.org.", Qtype: dns.TypeA,
Ns: []dns.RR{
test.SOA("example.org. 3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2016082540 7200 3600 1209600 3600"),
},
},
shouldCache: true,
},
{
name: "test negative zone exception with positive answer cache",
in: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("neg-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
out: test.Case{
Rcode: dns.RcodeSuccess,
Qname: "neg-disabled.example.org.", Qtype: dns.TypeA,
Answer: []dns.RR{
test.A("neg-disabled.example.org. 3600 IN A 127.0.0.1"),
},
},
shouldCache: true,
},
}
now, _ := time.Parse(time.UnixDate, "Fri Apr 21 10:51:21 BST 2017") now, _ := time.Parse(time.UnixDate, "Fri Apr 21 10:51:21 BST 2017")
utc := now.UTC() utc := now.UTC()
c, crr := newTestCache(maxTTL) for _, tc := range cacheTestCases {
t.Run(tc.name, func(t *testing.T) {
// Create a new cache every time to prevent accidental comparison with a previous item.
c, crr := newTestCache(maxTTL)
for n, tc := range cacheTestCases { m := tc.in.Msg()
m := tc.in.Msg() m = cacheMsg(m, tc.in)
m = cacheMsg(m, tc)
state := request.Request{W: &test.ResponseWriter{}, Req: m} state := request.Request{W: &test.ResponseWriter{}, Req: m}
mt, _ := response.Typify(m, utc) mt, _ := response.Typify(m, utc)
valid, k := key(state.Name(), m, mt, state.Do()) valid, k := key(state.Name(), m, mt, state.Do(), state.Req.CheckingDisabled)
if valid { if valid {
crr.set(m, k, mt, c.pttl) // Insert cache entry
} crr.set(m, k, mt, c.pttl)
i := c.getIgnoreTTL(time.Now().UTC(), state, "dns://:53")
ok := i != nil
if !tc.shouldCache && ok {
t.Errorf("Test %d: Cached message that should not have been cached: %s", n, state.Name())
continue
}
if tc.shouldCache && !ok {
t.Errorf("Test %d: Did not cache message that should have been cached: %s", n, state.Name())
continue
}
if ok {
resp := i.toMsg(m, time.Now().UTC(), state.Do(), m.AuthenticatedData)
if err := test.Header(tc.Case, resp); err != nil {
t.Logf("Cache %v", resp)
t.Error(err)
continue
} }
if err := test.Section(tc.Case, test.Answer, resp.Answer); err != nil { // Attempt to retrieve cache entry
t.Logf("Cache %v -- %v", test.Answer, resp.Answer) i := c.getIgnoreTTL(time.Now().UTC(), state, "dns://:53")
t.Error(err) found := i != nil
if !tc.shouldCache && found {
t.Fatalf("Cached message that should not have been cached: %s", state.Name())
} }
if err := test.Section(tc.Case, test.Ns, resp.Ns); err != nil { if tc.shouldCache && !found {
t.Error(err) t.Fatalf("Did not cache message that should have been cached: %s", state.Name())
} }
if err := test.Section(tc.Case, test.Extra, resp.Extra); err != nil {
t.Error(err) if found {
resp := i.toMsg(m, time.Now().UTC(), state.Do(), m.AuthenticatedData)
// TODO: If we incorporate these individual checks into the
// test.Header function, we can eliminate them from here.
// Cache entries are always Authoritative.
if resp.Authoritative != true {
t.Error("Expected Authoritative Answer bit to be true, but was false")
}
if resp.AuthenticatedData != tc.out.AuthenticatedData {
t.Errorf("Expected Authenticated Data bit to be %t, but got %t", tc.out.AuthenticatedData, resp.AuthenticatedData)
}
if resp.RecursionAvailable != tc.out.RecursionAvailable {
t.Errorf("Expected Recursion Available bit to be %t, but got %t", tc.out.RecursionAvailable, resp.RecursionAvailable)
}
if resp.CheckingDisabled != tc.out.CheckingDisabled {
t.Errorf("Expected Checking Disabled bit to be %t, but got %t", tc.out.CheckingDisabled, resp.CheckingDisabled)
}
if err := test.Header(tc.out, resp); err != nil {
t.Logf("Cache %v", resp)
t.Error(err)
}
if err := test.Section(tc.out, test.Answer, resp.Answer); err != nil {
t.Logf("Cache %v -- %v", test.Answer, resp.Answer)
t.Error(err)
}
if err := test.Section(tc.out, test.Ns, resp.Ns); err != nil {
t.Error(err)
}
if err := test.Section(tc.out, test.Extra, resp.Extra); err != nil {
t.Error(err)
}
} }
} })
} }
} }
@ -668,7 +701,7 @@ func TestCacheWildcardMetadata(t *testing.T) {
if c.pcache.Len() != 1 { if c.pcache.Len() != 1 {
t.Errorf("Msg should have been cached") t.Errorf("Msg should have been cached")
} }
_, k := key(qname, w.Msg, response.NoError, state.Do()) _, k := key(qname, w.Msg, response.NoError, state.Do(), state.Req.CheckingDisabled)
i, _ := c.pcache.Get(k) i, _ := c.pcache.Get(k)
if i.(*item).wildcard != wildcard { if i.(*item).wildcard != wildcard {
t.Errorf("expected wildcard response to enter cache with cache item's wildcard = %q, got %q", wildcard, i.(*item).wildcard) t.Errorf("expected wildcard response to enter cache with cache item's wildcard = %q, got %q", wildcard, i.(*item).wildcard)
@ -728,7 +761,129 @@ func TestCacheKeepTTL(t *testing.T) {
} }
} }
// wildcardMetadataBackend mocks a backend that reponds with a response for qname synthesized by wildcard // TestCacheSeparation verifies whether the cache maintains separation for specific DNS query types and options.
func TestCacheSeparation(t *testing.T) {
now, _ := time.Parse(time.UnixDate, "Fri Apr 21 10:51:21 BST 2017")
utc := now.UTC()
testCases := []struct {
name string
initial test.Case
query test.Case
expectCached bool // if a cache entry should be found before inserting
}{
{
name: "query type should be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeAAAA,
},
},
{
name: "DO bit should be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
Do: true,
},
},
{
name: "CD bit should be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
CheckingDisabled: true,
},
},
{
name: "CD bit and DO bit should be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
CheckingDisabled: true,
Do: true,
},
},
{
name: "CD bit, DO bit, and query type should be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeMX,
CheckingDisabled: true,
Do: true,
},
},
{
name: "authoritative answer bit should NOT be unique",
initial: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
},
query: test.Case{
Qname: "example.org.",
Qtype: dns.TypeA,
Authoritative: true,
},
expectCached: true,
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
c := New()
crr := &ResponseWriter{ResponseWriter: nil, Cache: c}
// Insert initial cache entry
m := tc.initial.Msg()
m = cacheMsg(m, tc.initial)
state := request.Request{W: &test.ResponseWriter{}, Req: m}
mt, _ := response.Typify(m, utc)
valid, k := key(state.Name(), m, mt, state.Do(), state.Req.CheckingDisabled)
if valid {
// Insert cache entry
crr.set(m, k, mt, c.pttl)
}
// Attempt to retrieve cache entry
m = tc.query.Msg()
m = cacheMsg(m, tc.query)
state = request.Request{W: &test.ResponseWriter{}, Req: m}
item := c.getIgnoreTTL(time.Now().UTC(), state, "dns://:53")
found := item != nil
if !tc.expectCached && found {
t.Fatal("Found cache message should that should not exist prior to inserting")
}
if tc.expectCached && !found {
t.Fatal("Did not find cache message that should exist prior to inserting")
}
})
}
}
// wildcardMetadataBackend mocks a backend that responds with a response for qname synthesized by wildcard
// and sets the zone/wildcard metadata value // and sets the zone/wildcard metadata value
func wildcardMetadataBackend(qname, wildcard string) plugin.Handler { func wildcardMetadataBackend(qname, wildcard string) plugin.Handler {
return plugin.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) { return plugin.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {

9
plugin/cache/handler.go vendored
View file

@ -18,6 +18,7 @@ func (c *Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
rc := r.Copy() // We potentially modify r, to prevent other plugins from seeing this (r is a pointer), copy r into rc. rc := r.Copy() // We potentially modify r, to prevent other plugins from seeing this (r is a pointer), copy r into rc.
state := request.Request{W: w, Req: rc} state := request.Request{W: w, Req: rc}
do := state.Do() do := state.Do()
cd := r.CheckingDisabled
ad := r.AuthenticatedData ad := r.AuthenticatedData
zone := plugin.Zones(c.Zones).Matches(state.Name()) zone := plugin.Zones(c.Zones).Matches(state.Name())
@ -36,7 +37,7 @@ func (c *Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
ttl := 0 ttl := 0
i := c.getIgnoreTTL(now, state, server) i := c.getIgnoreTTL(now, state, server)
if i == nil { if i == nil {
crr := &ResponseWriter{ResponseWriter: w, Cache: c, state: state, server: server, do: do, ad: ad, crr := &ResponseWriter{ResponseWriter: w, Cache: c, state: state, server: server, do: do, ad: ad, cd: cd,
nexcept: c.nexcept, pexcept: c.pexcept, wildcardFunc: wildcardFunc(ctx)} nexcept: c.nexcept, pexcept: c.pexcept, wildcardFunc: wildcardFunc(ctx)}
return c.doRefresh(ctx, state, crr) return c.doRefresh(ctx, state, crr)
} }
@ -44,7 +45,7 @@ func (c *Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
if ttl < 0 { if ttl < 0 {
// serve stale behavior // serve stale behavior
if c.verifyStale { if c.verifyStale {
crr := &ResponseWriter{ResponseWriter: w, Cache: c, state: state, server: server, do: do} crr := &ResponseWriter{ResponseWriter: w, Cache: c, state: state, server: server, do: do, cd: cd}
cw := newVerifyStaleResponseWriter(crr) cw := newVerifyStaleResponseWriter(crr)
ret, err := c.doRefresh(ctx, state, cw) ret, err := c.doRefresh(ctx, state, cw)
if cw.refreshed { if cw.refreshed {
@ -121,7 +122,7 @@ func (c *Cache) Name() string { return "cache" }
// getIgnoreTTL unconditionally returns an item if it exists in the cache. // getIgnoreTTL unconditionally returns an item if it exists in the cache.
func (c *Cache) getIgnoreTTL(now time.Time, state request.Request, server string) *item { func (c *Cache) getIgnoreTTL(now time.Time, state request.Request, server string) *item {
k := hash(state.Name(), state.QType(), state.Do()) k := hash(state.Name(), state.QType(), state.Do(), state.Req.CheckingDisabled)
cacheRequests.WithLabelValues(server, c.zonesMetricLabel, c.viewMetricLabel).Inc() cacheRequests.WithLabelValues(server, c.zonesMetricLabel, c.viewMetricLabel).Inc()
if i, ok := c.ncache.Get(k); ok { if i, ok := c.ncache.Get(k); ok {
@ -145,7 +146,7 @@ func (c *Cache) getIgnoreTTL(now time.Time, state request.Request, server string
} }
func (c *Cache) exists(state request.Request) *item { func (c *Cache) exists(state request.Request) *item {
k := hash(state.Name(), state.QType(), state.Do()) k := hash(state.Name(), state.QType(), state.Do(), state.Req.CheckingDisabled)
if i, ok := c.ncache.Get(k); ok { if i, ok := c.ncache.Get(k); ok {
return i.(*item) return i.(*item)
} }

83
plugin/cache/prefech_test.go → plugin/cache/prefetch_test.go vendored
View file

@ -28,12 +28,12 @@ func TestPrefetch(t *testing.T) {
{ {
after: 0 * time.Second, after: 0 * time.Second,
answer: "hits.reset.example.org. 80 IN A 127.0.0.1", answer: "hits.reset.example.org. 80 IN A 127.0.0.1",
fetch: true, fetch: true, // Initial fetch
}, },
{ {
after: 73 * time.Second, after: 73 * time.Second,
answer: "hits.reset.example.org. 7 IN A 127.0.0.1", answer: "hits.reset.example.org. 7 IN A 127.0.0.1",
fetch: true, fetch: true, // Triggers prefetch with 7 TTL (10% of 80 = 8 TTL threshold)
}, },
{ {
after: 80 * time.Second, after: 80 * time.Second,
@ -91,6 +91,68 @@ func TestPrefetch(t *testing.T) {
}, },
}, },
}, },
{
// tests whether cache prefetches with the do bit
qname: "do.prefetch.example.org.",
ttl: 80,
prefetch: 1,
verifications: []verification{
{
after: 0 * time.Second,
answer: "do.prefetch.example.org. 80 IN A 127.0.0.1",
do: true,
fetch: true,
},
{
after: 73 * time.Second,
answer: "do.prefetch.example.org. 7 IN A 127.0.0.1",
do: true,
fetch: true,
},
{
after: 80 * time.Second,
answer: "do.prefetch.example.org. 73 IN A 127.0.0.2",
do: true,
},
{
// Should be 127.0.0.3 as 127.0.0.2 was the prefetch WITH do bit
after: 80 * time.Second,
answer: "do.prefetch.example.org. 80 IN A 127.0.0.3",
fetch: true,
},
},
},
{
// tests whether cache prefetches with the cd bit
qname: "cd.prefetch.example.org.",
ttl: 80,
prefetch: 1,
verifications: []verification{
{
after: 0 * time.Second,
answer: "cd.prefetch.example.org. 80 IN A 127.0.0.1",
cd: true,
fetch: true,
},
{
after: 73 * time.Second,
answer: "cd.prefetch.example.org. 7 IN A 127.0.0.1",
cd: true,
fetch: true,
},
{
after: 80 * time.Second,
answer: "cd.prefetch.example.org. 73 IN A 127.0.0.2",
cd: true,
},
{
// Should be 127.0.0.3 as 127.0.0.2 was the prefetch WITH cd bit
after: 80 * time.Second,
answer: "cd.prefetch.example.org. 80 IN A 127.0.0.3",
fetch: true,
},
},
},
} }
t0, err := time.Parse(time.RFC3339, "2018-01-01T14:00:00+00:00") t0, err := time.Parse(time.RFC3339, "2018-01-01T14:00:00+00:00")
@ -102,28 +164,29 @@ func TestPrefetch(t *testing.T) {
fetchc := make(chan struct{}, 1) fetchc := make(chan struct{}, 1)
c := New() c := New()
c.prefetch = tt.prefetch
c.Next = prefetchHandler(tt.qname, tt.ttl, fetchc) c.Next = prefetchHandler(tt.qname, tt.ttl, fetchc)
c.prefetch = tt.prefetch
req := new(dns.Msg)
req.SetQuestion(tt.qname, dns.TypeA)
rec := dnstest.NewRecorder(&test.ResponseWriter{}) rec := dnstest.NewRecorder(&test.ResponseWriter{})
for _, v := range tt.verifications { for _, v := range tt.verifications {
c.now = func() time.Time { return t0.Add(v.after) } c.now = func() time.Time { return t0.Add(v.after) }
req := new(dns.Msg)
req.SetQuestion(tt.qname, dns.TypeA)
req.CheckingDisabled = v.cd
req.SetEdns0(512, v.do)
c.ServeDNS(context.TODO(), rec, req) c.ServeDNS(context.TODO(), rec, req)
if v.fetch { if v.fetch {
select { select {
case <-fetchc: case <-fetchc:
if !v.fetch { // Prefetch handler was called.
t.Fatalf("After %s: want request to trigger a prefetch", v.after)
}
case <-time.After(time.Second): case <-time.After(time.Second):
t.Fatalf("After %s: want request to trigger a prefetch", v.after) t.Fatalf("After %s: want request to trigger a prefetch", v.after)
} }
} }
if want, got := rec.Rcode, dns.RcodeSuccess; want != got { if want, got := dns.RcodeSuccess, rec.Rcode; want != got {
t.Errorf("After %s: want rcode %d, got %d", v.after, want, got) t.Errorf("After %s: want rcode %d, got %d", v.after, want, got)
} }
if want, got := 1, len(rec.Msg.Answer); want != got { if want, got := 1, len(rec.Msg.Answer); want != got {
@ -140,6 +203,8 @@ func TestPrefetch(t *testing.T) {
type verification struct { type verification struct {
after time.Duration after time.Duration
answer string answer string
do bool
cd bool
// fetch defines whether a request is sent to the next handler. // fetch defines whether a request is sent to the next handler.
fetch bool fetch bool
} }

22
plugin/test/helpers.go
View file

@ -29,15 +29,19 @@ func (p RRSet) Less(i, j int) bool { return p[i].String() < p[j].String() }
// Case represents a test case that encapsulates various data from a query and response. // Case represents a test case that encapsulates various data from a query and response.
// Note that is the TTL of a record is 303 we don't compare it with the TTL. // Note that is the TTL of a record is 303 we don't compare it with the TTL.
type Case struct { type Case struct {
Qname string Qname string
Qtype uint16 Qtype uint16
Rcode int Rcode int
Do bool Do bool
AuthenticatedData bool CheckingDisabled bool
Answer []dns.RR RecursionAvailable bool
Ns []dns.RR AuthenticatedData bool
Extra []dns.RR Authoritative bool
Error error Truncated bool
Answer []dns.RR
Ns []dns.RR
Extra []dns.RR
Error error
} }
// Msg returns a *dns.Msg embedded in c. // Msg returns a *dns.Msg embedded in c.