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DNS lookups should not be case sensitive.

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- On-the-wire gossip messages are sorted case sensitive, but in memory they are sorted case-insensitive.
- Add test for case insensitive match on multiple names.
This commit is contained in:
Tom Wilkie committed 2015-10-01 12:19:49 +00:00
1 parent a3484cce43
commit 357174e351
4 files changed
+104 -30
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nameserver/entry.go
+69 -26
View File
@@ -5,6 +5,7 @@ import (
"encoding/gob"
"fmt"
"sort"
"strings"
"time"
"github.com/weaveworks/weave/net/address"
@@ -23,8 +24,26 @@ type Entry struct {
}
type Entries []Entry
type CaseSensitive Entries
type CaseInsensitive Entries
type SortableEntries interface {
sort.Interface
Get(i int) Entry
}
func (e1 *Entry) equal(e2 *Entry) bool {
// Gossip messages are sorted in a case sensitive order...
func (es CaseSensitive) Len() int { return len(es) }
func (es CaseSensitive) Swap(i, j int) { es[i], es[j] = es[j], es[i] }
func (es CaseSensitive) Get(i int) Entry { return es[i] }
func (es CaseSensitive) Less(i, j int) bool { return es[i].less(&es[j]) }
// ... but we store entries in a case insensitive order.
func (es CaseInsensitive) Len() int { return len(es) }
func (es CaseInsensitive) Swap(i, j int) { es[i], es[j] = es[j], es[i] }
func (es CaseInsensitive) Get(i int) Entry { return es[i] }
func (es CaseInsensitive) Less(i, j int) bool { return es[i].insensitiveLess(&es[j]) }
func (e1 Entry) equal(e2 Entry) bool {
return e1.ContainerID == e2.ContainerID &&
e1.Origin == e2.Origin &&
e1.Addr == e2.Addr &&
@@ -48,6 +67,24 @@ func (e1 *Entry) less(e2 *Entry) bool {
}
}
func (e1 *Entry) insensitiveLess(e2 *Entry) bool {
// Entries are kept sorted by Hostname, Origin, ContainerID then address
e1Hostname, e2Hostname := strings.ToLower(e1.Hostname), strings.ToLower(e2.Hostname)
switch {
case e1Hostname != e2Hostname:
return e1Hostname < e2Hostname
case e1.Origin != e2.Origin:
return e1.Origin < e2.Origin
case e1.ContainerID != e2.ContainerID:
return e1.ContainerID < e2.ContainerID
default:
return e1.Addr < e2.Addr
}
}
// returns true to indicate a change
func (e1 *Entry) merge(e2 *Entry) bool {
// we know container id, origin, add and hostname are equal
@@ -63,37 +100,37 @@ func (e1 *Entry) String() string {
return fmt.Sprintf("%s -> %s", e1.Hostname, e1.Addr.String())
}
func (es Entries) Len() int { return len(es) }
func (es Entries) Swap(i, j int) { panic("Swap") }
func (es Entries) Less(i, j int) bool { return es[i].less(&es[j]) }
func (es Entries) check() error {
func check(es SortableEntries) error {
if !sort.IsSorted(es) {
return fmt.Errorf("Not sorted!")
}
for i := 1; i < len(es); i++ {
if es[i].equal(&es[i-1]) {
return fmt.Errorf("Duplicate entry: %d:%v and %d:%v", i-1, es[i-1], i, es[i])
for i := 1; i < es.Len(); i++ {
if es.Get(i).equal(es.Get(i - 1)) {
return fmt.Errorf("Duplicate entry: %d:%v and %d:%v", i-1, es.Get(i-1), i, es.Get(i))
}
}
return nil
}
func (es *Entries) checkAndPanic() {
if err := es.check(); err != nil {
func checkAndPanic(es SortableEntries) {
if err := check(es); err != nil {
panic(err)
}
}
func (es *Entries) checkAndPanic() *Entries {
checkAndPanic(CaseInsensitive(*es))
return es
}
func (es *Entries) add(hostname, containerid string, origin router.PeerName, addr address.Address) Entry {
es.checkAndPanic()
defer es.checkAndPanic()
defer es.checkAndPanic().checkAndPanic()
entry := Entry{Hostname: hostname, Origin: origin, ContainerID: containerid, Addr: addr}
i := sort.Search(len(*es), func(i int) bool {
return !(*es)[i].less(&entry)
return !(*es)[i].insensitiveLess(&entry)
})
if i < len(*es) && (*es)[i].equal(&entry) {
if i < len(*es) && (*es)[i].equal(entry) {
if (*es)[i].Tombstone > 0 {
(*es)[i].Tombstone = 0
(*es)[i].Version++
@@ -107,16 +144,16 @@ func (es *Entries) add(hostname, containerid string, origin router.PeerName, add
}
func (es *Entries) merge(incoming Entries) Entries {
es.checkAndPanic()
defer es.checkAndPanic()
defer es.checkAndPanic().checkAndPanic()
newEntries := Entries{}
i := 0
for _, entry := range incoming {
for i < len(*es) && (*es)[i].less(&entry) {
for i < len(*es) && (*es)[i].insensitiveLess(&entry) {
i++
}
if i < len(*es) && (*es)[i].equal(&entry) {
if i < len(*es) && (*es)[i].equal(entry) {
if (*es)[i].merge(&entry) {
newEntries = append(newEntries, entry)
}
@@ -133,8 +170,8 @@ func (es *Entries) merge(incoming Entries) Entries {
// f returning true means keep the entry.
func (es *Entries) tombstone(ourname router.PeerName, f func(*Entry) bool) Entries {
es.checkAndPanic()
defer es.checkAndPanic()
defer es.checkAndPanic().checkAndPanic()
tombstoned := Entries{}
for i, e := range *es {
if f(&e) && e.Origin == ourname {
@@ -148,8 +185,8 @@ func (es *Entries) tombstone(ourname router.PeerName, f func(*Entry) bool) Entri
}
func (es *Entries) filter(f func(*Entry) bool) {
es.checkAndPanic()
defer es.checkAndPanic()
defer es.checkAndPanic().checkAndPanic()
i := 0
for _, e := range *es {
if !f(&e) {
@@ -163,15 +200,17 @@ func (es *Entries) filter(f func(*Entry) bool) {
func (es Entries) lookup(hostname string) Entries {
es.checkAndPanic()
lowerHostname := strings.ToLower(hostname)
i := sort.Search(len(es), func(i int) bool {
return es[i].Hostname >= hostname
return strings.ToLower(es[i].Hostname) >= lowerHostname
})
if i >= len(es) || es[i].Hostname != hostname {
if i >= len(es) || strings.ToLower(es[i].Hostname) != lowerHostname {
return Entries{}
}
j := sort.Search(len(es)-i, func(j int) bool {
return es[i+j].Hostname > hostname
return strings.ToLower(es[i+j].Hostname) > lowerHostname
})
return es[i : i+j]
@@ -179,6 +218,7 @@ func (es Entries) lookup(hostname string) Entries {
func (es *Entries) first(f func(*Entry) bool) (*Entry, error) {
es.checkAndPanic()
for _, e := range *es {
if f(&e) {
return &e, nil
@@ -193,6 +233,8 @@ type GossipData struct {
}
func (g *GossipData) Merge(o router.GossipData) {
checkAndPanic(CaseSensitive(g.Entries))
defer func() { checkAndPanic(CaseSensitive(g.Entries)) }()
other := o.(*GossipData)
g.Entries.merge(other.Entries)
if g.Timestamp < other.Timestamp {
@@ -201,6 +243,7 @@ func (g *GossipData) Merge(o router.GossipData) {
}
func (g *GossipData) Encode() [][]byte {
checkAndPanic(CaseSensitive(g.Entries))
buf := &bytes.Buffer{}
if err := gob.NewEncoder(buf).Encode(g); err != nil {
panic(err)
nameserver/nameserver.go
+3 -3
View File
@@ -4,6 +4,7 @@ import (
"bytes"
"encoding/gob"
"fmt"
"sort"
"sync"
"time"
@@ -198,6 +199,7 @@ func (n *Nameserver) Gossip() router.GossipData {
Timestamp: now(),
}
copy(gossip.Entries, n.entries)
sort.Sort(CaseSensitive(gossip.Entries))
return gossip
}
@@ -215,9 +217,7 @@ func (n *Nameserver) receiveGossip(msg []byte) (router.GossipData, router.Gossip
return nil, nil, fmt.Errorf("clock skew of %d detected", delta)
}
if err := gossip.Entries.check(); err != nil {
return nil, nil, err
}
sort.Sort(CaseInsensitive(gossip.Entries))
n.Lock()
defer n.Unlock()
test/245_dns_case_insensitive_test.sh
Executable
+31
View File
@@ -0,0 +1,31 @@
#! /bin/bash
. ./config.sh
C1=10.2.0.78
C2=10.2.0.79
C3=10.2.0.80
start_suite "DNS lookup case (in)sensitivity"
weave_on $HOST1 launch
start_container_with_dns $HOST1 --name=test
start_container $HOST1 $C1/24 --name=seeone
assert_dns_record $HOST1 test seeone.weave.local $C1
assert_dns_record $HOST1 test SeeOne.weave.local $C1
assert_dns_record $HOST1 test SEEONE.weave.local $C1
start_container $HOST1 $C2/24 --name=SeEtWo
assert_dns_record $HOST1 test seetwo.weave.local $C2
assert_dns_record $HOST1 test SeeTwo.weave.local $C2
assert_dns_record $HOST1 test SEETWO.weave.local $C2
start_container $HOST1 $C3/24 --name=seetwo
assert_dns_record $HOST1 test seetwo.weave.local $C2 $C3
assert_dns_record $HOST1 test SeeTwo.weave.local $C2 $C3
assert_dns_record $HOST1 test SEETWO.weave.local $C2 $C3
assert "exec_on $HOST1 test dig +short seetwo.weave.local A | grep -v ';;' | wc -l" 2
end_suite
test/config.sh
+1 -1
View File
@@ -188,7 +188,7 @@ assert_dns_record() {
[ -z "$DEBUG" ] || greyly echo "Checking whether the IPs '$@' exists at $host:$container"
for ip in "$@" ; do
assert "exec_on $host $container getent hosts $ip | tr -s ' '" "$ip $name"
assert "exec_on $host $container getent hosts $ip | tr -s ' ' | tr '[:upper:]' '[:lower:]'" "$(echo $ip $name | tr '[:upper:]' '[:lower:]')"
done
}