From 963d585156fcbc58290fe5629bc5f508cb4259f2 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Thu, 13 May 2021 14:31:12 -0700
Subject: [PATCH] XXX: plumb a Pinger down to controlclient

---
 control/controlclient/direct.go | 10 ++++++++++
 ipn/ipnlocal/local.go           |  1 +
 2 files changed, 11 insertions(+)

diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go
index 5e522ed93..3e0f7d788 100644
--- a/control/controlclient/direct.go
+++ b/control/controlclient/direct.go
@@ -32,6 +32,7 @@
 	"golang.org/x/crypto/nacl/box"
 	"inet.af/netaddr"
 	"tailscale.com/health"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/log/logheap"
 	"tailscale.com/net/dnscache"
 	"tailscale.com/net/dnsfallback"
@@ -66,6 +67,7 @@ type Direct struct {
 	debugFlags             []string
 	keepSharerAndUserSplit bool
 	skipIPForwardingCheck  bool
+	pinger                 Pinger
 
 	mu           sync.Mutex // mutex guards the following fields
 	serverKey    wgkey.Key
@@ -80,6 +82,12 @@ type Direct struct {
 	localPort     uint16 // or zero to mean auto
 }
 
+type Pinger interface {
+	// Ping is a request to start a discovery ping with the peer handling
+	// the given IP and then call cb with its ping latency & method.
+	Ping(ip netaddr.IP, useTSMP bool, cb func(*ipnstate.PingResult))
+}
+
 type Options struct {
 	Persist              persist.Persist               // initial persistent data
 	GetMachinePrivateKey func() (wgkey.Private, error) // returns the machine key to use
@@ -94,6 +102,7 @@ type Options struct {
 	HTTPTestClient       *http.Client // optional HTTP client to use (for tests only)
 	DebugFlags           []string     // debug settings to send to control
 	LinkMonitor          *monitor.Mon // optional link monitor
+	Pinger               Pinger
 
 	// KeepSharerAndUserSplit controls whether the client
 	// understands Node.Sharer. If false, the Sharer is mapped to the User.
@@ -165,6 +174,7 @@ func NewDirect(opts Options) (*Direct, error) {
 		keepSharerAndUserSplit: opts.KeepSharerAndUserSplit,
 		linkMon:                opts.LinkMonitor,
 		skipIPForwardingCheck:  opts.SkipIPForwardingCheck,
+		pinger:                 opts.Pinger,
 	}
 	if opts.Hostinfo == nil {
 		c.SetHostinfo(NewHostinfo())
diff --git a/ipn/ipnlocal/local.go b/ipn/ipnlocal/local.go
index 00065623a..fdd6d1ed8 100644
--- a/ipn/ipnlocal/local.go
+++ b/ipn/ipnlocal/local.go
@@ -808,6 +808,7 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 		DiscoPublicKey:       discoPublic,
 		DebugFlags:           debugFlags,
 		LinkMonitor:          b.e.GetLinkMonitor(),
+		Pinger:               b.e,
 
 		// Don't warn about broken Linux IP forwading when
 		// netstack is being used.