device: remove listen port race in tests

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2021-02-09 00:59:39 +01:00
parent a60e6dab76
commit 6548a682a9

View file

@ -22,15 +22,6 @@ import (
"golang.zx2c4.com/wireguard/tun/tuntest" "golang.zx2c4.com/wireguard/tun/tuntest"
) )
func getFreePort(tb testing.TB) string {
l, err := net.ListenPacket("udp", "localhost:0")
if err != nil {
tb.Fatal(err)
}
defer l.Close()
return fmt.Sprintf("%d", l.LocalAddr().(*net.UDPAddr).Port)
}
// uapiCfg returns a string that contains cfg formatted use with IpcSet. // uapiCfg returns a string that contains cfg formatted use with IpcSet.
// cfg is a series of alternating key/value strings. // cfg is a series of alternating key/value strings.
// uapiCfg exists because editors and humans like to insert // uapiCfg exists because editors and humans like to insert
@ -55,12 +46,7 @@ func uapiCfg(cfg ...string) string {
// genConfigs generates a pair of configs that connect to each other. // genConfigs generates a pair of configs that connect to each other.
// The configs use distinct, probably-usable ports. // The configs use distinct, probably-usable ports.
func genConfigs(tb testing.TB) (cfgs [2]string) { func genConfigs(tb testing.TB) (cfgs [2]string, endpointCfgs [2]string) {
var port1, port2 string
for port1 == port2 {
port1 = getFreePort(tb)
port2 = getFreePort(tb)
}
var key1, key2 NoisePrivateKey var key1, key2 NoisePrivateKey
_, err := rand.Read(key1[:]) _, err := rand.Read(key1[:])
if err != nil { if err != nil {
@ -74,23 +60,29 @@ func genConfigs(tb testing.TB) (cfgs [2]string) {
cfgs[0] = uapiCfg( cfgs[0] = uapiCfg(
"private_key", hex.EncodeToString(key1[:]), "private_key", hex.EncodeToString(key1[:]),
"listen_port", port1, "listen_port", "0",
"replace_peers", "true", "replace_peers", "true",
"public_key", hex.EncodeToString(pub2[:]), "public_key", hex.EncodeToString(pub2[:]),
"protocol_version", "1", "protocol_version", "1",
"replace_allowed_ips", "true", "replace_allowed_ips", "true",
"allowed_ip", "1.0.0.2/32", "allowed_ip", "1.0.0.2/32",
"endpoint", "127.0.0.1:"+port2, )
endpointCfgs[0] = uapiCfg(
"public_key", hex.EncodeToString(pub2[:]),
"endpoint", "127.0.0.1:%d",
) )
cfgs[1] = uapiCfg( cfgs[1] = uapiCfg(
"private_key", hex.EncodeToString(key2[:]), "private_key", hex.EncodeToString(key2[:]),
"listen_port", port2, "listen_port", "0",
"replace_peers", "true", "replace_peers", "true",
"public_key", hex.EncodeToString(pub1[:]), "public_key", hex.EncodeToString(pub1[:]),
"protocol_version", "1", "protocol_version", "1",
"replace_allowed_ips", "true", "replace_allowed_ips", "true",
"allowed_ip", "1.0.0.1/32", "allowed_ip", "1.0.0.1/32",
"endpoint", "127.0.0.1:"+port1, )
endpointCfgs[1] = uapiCfg(
"public_key", hex.EncodeToString(pub1[:]),
"endpoint", "127.0.0.1:%d",
) )
return return
} }
@ -154,19 +146,12 @@ func (pair *testPair) Send(tb testing.TB, ping SendDirection, done chan struct{}
// genTestPair creates a testPair. // genTestPair creates a testPair.
func genTestPair(tb testing.TB) (pair testPair) { func genTestPair(tb testing.TB) (pair testPair) {
const maxAttempts = 10 cfg, endpointCfg := genConfigs(tb)
NextAttempt:
for i := 0; i < maxAttempts; i++ {
cfg := genConfigs(tb)
// Bring up a ChannelTun for each config. // Bring up a ChannelTun for each config.
for i := range pair { for i := range pair {
p := &pair[i] p := &pair[i]
p.tun = tuntest.NewChannelTUN() p.tun = tuntest.NewChannelTUN()
if i == 0 { p.ip = net.IPv4(1, 0, 0, byte(i+1))
p.ip = net.ParseIP("1.0.0.1")
} else {
p.ip = net.ParseIP("1.0.0.2")
}
level := LogLevelVerbose level := LogLevelVerbose
if _, ok := tb.(*testing.B); ok && !testing.Verbose() { if _, ok := tb.(*testing.B); ok && !testing.Verbose() {
level = LogLevelError level = LogLevelError
@ -174,32 +159,27 @@ NextAttempt:
p.dev = NewDevice(p.tun.TUN(), NewLogger(level, fmt.Sprintf("dev%d: ", i))) p.dev = NewDevice(p.tun.TUN(), NewLogger(level, fmt.Sprintf("dev%d: ", i)))
p.dev.Up() p.dev.Up()
if err := p.dev.IpcSet(cfg[i]); err != nil { if err := p.dev.IpcSet(cfg[i]); err != nil {
// genConfigs attempted to pick ports that were free. tb.Errorf("failed to configure device %d: %v", i, err)
// There's a tiny window between genConfigs closing the port
// and us opening it, during which another process could
// start using it. We probably just lost that race.
// Try again from the beginning.
// If there's something permanent wrong,
// we'll see that when we run out of attempts.
tb.Logf("failed to configure device %d: %v", i, err)
p.dev.Close() p.dev.Close()
continue NextAttempt continue
} }
// The device might still not be up, e.g. due to an error
// in RoutineTUNEventReader's call to dev.Up that got swallowed.
// Assume it's due to a transient error (port in use), and retry.
if !p.dev.isUp() { if !p.dev.isUp() {
tb.Logf("device %d did not come up, trying again", i) tb.Errorf("device %d did not come up", i)
p.dev.Close() p.dev.Close()
continue NextAttempt continue
} }
// The device is up. Close it when the test completes. endpointCfg[i^1] = fmt.Sprintf(endpointCfg[i^1], p.dev.net.port)
}
for i := range pair {
p := &pair[i]
if err := p.dev.IpcSet(endpointCfg[i]); err != nil {
tb.Errorf("failed to configure device endpoint %d: %v", i, err)
p.dev.Close()
continue
}
// The device is ready. Close it when the test completes.
tb.Cleanup(p.dev.Close) tb.Cleanup(p.dev.Close)
} }
return // success
}
tb.Fatalf("genChannelTUNs: failed %d times", maxAttempts)
return return
} }