From 42fd96409023f2d2d8ec0111c18e6be0c4791bad Mon Sep 17 00:00:00 2001 From: Andrew Dunham Date: Sat, 29 Apr 2023 20:25:37 -0700 Subject: [PATCH] control/controlclient: use dnscache.Resolver for Noise client This passes the *dnscache.Resolver down from the Direct client into the Noise client and from there into the controlhttp client. This retains the Resolver so that it can share state across calls instead of creating a new resolver. Updates #4845 Updates #6110 Signed-off-by: Andrew Dunham Change-Id: Ia5d6af1870f3b5b5d7dd5685d775dcf300aec7af --- control/controlclient/direct.go | 28 ++++++++++++----- control/controlclient/noise.go | 47 ++++++++++++++++++++++++----- control/controlclient/noise_test.go | 7 ++++- control/controlhttp/client.go | 24 ++++++++++----- control/controlhttp/constants.go | 5 +++ 5 files changed, 87 insertions(+), 24 deletions(-) diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go index cf6fd9987..006f2614a 100644 --- a/control/controlclient/direct.go +++ b/control/controlclient/direct.go @@ -61,6 +61,7 @@ type Direct struct { httpc *http.Client // HTTP client used to talk to tailcontrol dialer *tsdial.Dialer + dnsCache *dnscache.Resolver serverURL string // URL of the tailcontrol server timeNow func() time.Time lastPrintMap time.Time @@ -199,6 +200,14 @@ func NewDirect(opts Options) (*Direct, error) { opts.Logf = log.Printf } + dnsCache := &dnscache.Resolver{ + Forward: dnscache.Get().Forward, // use default cache's forwarder + UseLastGood: true, + LookupIPFallback: dnsfallback.MakeLookupFunc(opts.Logf, opts.NetMon), + Logf: opts.Logf, + NetMon: opts.NetMon, + } + httpc := opts.HTTPTestClient if httpc == nil && runtime.GOOS == "js" { // In js/wasm, net/http.Transport (as of Go 1.18) will @@ -208,13 +217,6 @@ func NewDirect(opts Options) (*Direct, error) { httpc = http.DefaultClient } if httpc == nil { - dnsCache := &dnscache.Resolver{ - Forward: dnscache.Get().Forward, // use default cache's forwarder - UseLastGood: true, - LookupIPFallback: dnsfallback.MakeLookupFunc(opts.Logf, opts.NetMon), - Logf: opts.Logf, - NetMon: opts.NetMon, - } tr := http.DefaultTransport.(*http.Transport).Clone() tr.Proxy = tshttpproxy.ProxyFromEnvironment tshttpproxy.SetTransportGetProxyConnectHeader(tr) @@ -250,6 +252,7 @@ func NewDirect(opts Options) (*Direct, error) { onControlTime: opts.OnControlTime, c2nHandler: opts.C2NHandler, dialer: opts.Dialer, + dnsCache: dnsCache, dialPlan: opts.DialPlan, } if opts.Hostinfo == nil { @@ -1509,7 +1512,16 @@ func (c *Direct) getNoiseClient() (*NoiseClient, error) { return nil, err } c.logf("creating new noise client") - nc, err := NewNoiseClient(k, serverNoiseKey, c.serverURL, c.dialer, c.logf, c.netMon, dp) + nc, err := NewNoiseClient(NoiseOpts{ + PrivKey: k, + ServerPubKey: serverNoiseKey, + ServerURL: c.serverURL, + Dialer: c.dialer, + DNSCache: c.dnsCache, + Logf: c.logf, + NetMon: c.netMon, + DialPlan: dp, + }) if err != nil { return nil, err } diff --git a/control/controlclient/noise.go b/control/controlclient/noise.go index 61c472a35..cad81b82c 100644 --- a/control/controlclient/noise.go +++ b/control/controlclient/noise.go @@ -19,6 +19,7 @@ "golang.org/x/net/http2" "tailscale.com/control/controlbase" "tailscale.com/control/controlhttp" + "tailscale.com/net/dnscache" "tailscale.com/net/netmon" "tailscale.com/net/tsdial" "tailscale.com/tailcfg" @@ -158,6 +159,7 @@ type NoiseClient struct { sfDial singleflight.Group[struct{}, *noiseConn] dialer *tsdial.Dialer + dnsCache *dnscache.Resolver privKey key.MachinePrivate serverPubKey key.MachinePublic host string // the host part of serverURL @@ -179,13 +181,39 @@ type NoiseClient struct { connPool map[int]*noiseConn // active connections not yet closed; see noiseConn.Close } +// NoiseOpts contains options for the NewNoiseClient function. All fields are +// required unless otherwise specified. +type NoiseOpts struct { + // PrivKey is this node's private key. + PrivKey key.MachinePrivate + // ServerPubKey is the public key of the server. + ServerPubKey key.MachinePublic + // ServerURL is the URL of the server to connect to. + ServerURL string + // Dialer's SystemDial function is used to connect to the server. + Dialer *tsdial.Dialer + // DNSCache is the caching Resolver to use to connect to the server. + // + // This field can be nil. + DNSCache *dnscache.Resolver + // Logf is the log function to use. This field can be nil. + Logf logger.Logf + // NetMon is the network monitor that, if set, will be used to get the + // network interface state. This field can be nil; if so, the current + // state will be looked up dynamically. + NetMon *netmon.Monitor + // DialPlan, if set, is a function that should return an explicit plan + // on how to connect to the server. + DialPlan func() *tailcfg.ControlDialPlan +} + // NewNoiseClient returns a new noiseClient for the provided server and machine key. // serverURL is of the form https://: (no trailing slash). // // netMon may be nil, if non-nil it's used to do faster interface lookups. // dialPlan may be nil -func NewNoiseClient(privKey key.MachinePrivate, serverPubKey key.MachinePublic, serverURL string, dialer *tsdial.Dialer, logf logger.Logf, netMon *netmon.Monitor, dialPlan func() *tailcfg.ControlDialPlan) (*NoiseClient, error) { - u, err := url.Parse(serverURL) +func NewNoiseClient(opts NoiseOpts) (*NoiseClient, error) { + u, err := url.Parse(opts.ServerURL) if err != nil { return nil, err } @@ -205,16 +233,18 @@ func NewNoiseClient(privKey key.MachinePrivate, serverPubKey key.MachinePublic, httpPort = "80" httpsPort = "443" } + np := &NoiseClient{ - serverPubKey: serverPubKey, - privKey: privKey, + serverPubKey: opts.ServerPubKey, + privKey: opts.PrivKey, host: u.Hostname(), httpPort: httpPort, httpsPort: httpsPort, - dialer: dialer, - dialPlan: dialPlan, - logf: logf, - netMon: netMon, + dialer: opts.Dialer, + dnsCache: opts.DNSCache, + dialPlan: opts.DialPlan, + logf: opts.Logf, + netMon: opts.NetMon, } // Create the HTTP/2 Transport using a net/http.Transport @@ -373,6 +403,7 @@ func (nc *NoiseClient) dial() (*noiseConn, error) { ControlKey: nc.serverPubKey, ProtocolVersion: uint16(tailcfg.CurrentCapabilityVersion), Dialer: nc.dialer.SystemDial, + DNSCache: nc.dnsCache, DialPlan: dialPlan, Logf: nc.logf, NetMon: nc.netMon, diff --git a/control/controlclient/noise_test.go b/control/controlclient/noise_test.go index 11e35f0af..9961e3318 100644 --- a/control/controlclient/noise_test.go +++ b/control/controlclient/noise_test.go @@ -74,7 +74,12 @@ func (tt noiseClientTest) run(t *testing.T) { defer hs.Close() dialer := new(tsdial.Dialer) - nc, err := NewNoiseClient(clientPrivate, serverPrivate.Public(), hs.URL, dialer, nil, nil, nil) + nc, err := NewNoiseClient(NoiseOpts{ + PrivKey: clientPrivate, + ServerPubKey: serverPrivate.Public(), + ServerURL: hs.URL, + Dialer: dialer, + }) if err != nil { t.Fatal(err) } diff --git a/control/controlhttp/client.go b/control/controlhttp/client.go index d04aac518..b0d91bada 100644 --- a/control/controlhttp/client.go +++ b/control/controlhttp/client.go @@ -374,6 +374,22 @@ func (a *Dialer) dialURL(ctx context.Context, u *url.URL, addr netip.Addr) (*Cli }, nil } +// resolver returns a.DNSCache if non-nil or a new *dnscache.Resolver +// otherwise. +func (a *Dialer) resolver() *dnscache.Resolver { + if a.DNSCache != nil { + return a.DNSCache + } + + return &dnscache.Resolver{ + Forward: dnscache.Get().Forward, + LookupIPFallback: dnsfallback.MakeLookupFunc(a.logf, a.NetMon), + UseLastGood: true, + Logf: a.Logf, // not a.logf method; we want to propagate nil-ness + NetMon: a.NetMon, + } +} + // tryURLUpgrade connects to u, and tries to upgrade it to a net.Conn. If addr // is valid, then no DNS is used and the connection will be made to the // provided address. @@ -392,13 +408,7 @@ func (a *Dialer) tryURLUpgrade(ctx context.Context, u *url.URL, addr netip.Addr, NetMon: a.NetMon, } } else { - dns = &dnscache.Resolver{ - Forward: dnscache.Get().Forward, - LookupIPFallback: dnsfallback.MakeLookupFunc(a.logf, a.NetMon), - UseLastGood: true, - Logf: a.Logf, // not a.logf method; we want to propagate nil-ness - NetMon: a.NetMon, - } + dns = a.resolver() } var dialer dnscache.DialContextFunc diff --git a/control/controlhttp/constants.go b/control/controlhttp/constants.go index a58ee5374..b838f84c4 100644 --- a/control/controlhttp/constants.go +++ b/control/controlhttp/constants.go @@ -67,6 +67,11 @@ type Dialer struct { // If not specified, this defaults to net.Dialer.DialContext. Dialer dnscache.DialContextFunc + // DNSCache is the caching Resolver used by this Dialer. + // + // If not specified, a new Resolver is created per attempt. + DNSCache *dnscache.Resolver + // Logf, if set, is a logging function to use; if unset, logs are // dropped. Logf logger.Logf