magicsock, wgengine, ipn, controlclient: plumb regular netchecks to map poll

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlclient/direct.go

@@ -176,6 +176,23 @@ func (c *Direct) SetHostinfo(hi *tailcfg.Hostinfo) {
 	c.hostinfo = hi.Clone()
 }
 
+// SetNetInfo clones the provided NetInfo and remembers it for the
+// next update.
+func (c *Direct) SetNetInfo(ni *tailcfg.NetInfo) {
+	if ni == nil {
+		panic("nil NetInfo")
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.hostinfo == nil {
+		c.logf("[unexpected] SetNetInfo called with no HostInfo; ignoring NetInfo update: %+v", ni)
+		return
+	}
+	c.logf("NetInfo: %v\n", ni)
+	c.hostinfo.NetInfo = ni.Clone()
+}
+
 func (c *Direct) GetPersist() Persist {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -650,6 +667,12 @@ func encode(v interface{}, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) ([]byte
 	if err != nil {
 		return nil, err
 	}
+	const debugMapRequests = false
+	if debugMapRequests {
+		if _, ok := v.(tailcfg.MapRequest); ok {
+			log.Printf("MapRequest: %s", b)
+		}
+	}
 	var nonce [24]byte
 	if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
 		panic(err)