cmd/tailscaled, wgengine, ipn: add /debug/ipn handler with world state

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

wgengine/magicsock/magicsock.go

@@ -33,6 +33,7 @@ import (
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
 	"tailscale.com/derp/derpmap"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/net/dnscache"
 	"tailscale.com/net/interfaces"
 	"tailscale.com/netcheck"
@@ -1898,3 +1899,37 @@ func sbPrintAddr(sb *strings.Builder, a net.UDPAddr) {
 	}
 	fmt.Fprintf(sb, ":%d", a.Port)
 }
+
+func (c *Conn) UpdateStatus(sb *ipnstate.StatusBuilder) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for k, as := range c.addrsByKey {
+		ps := &ipnstate.PeerStatus{
+			InMagicSock: true,
+		}
+		for i, ua := range as.addrs {
+			uaStr := udpAddrDebugString(ua)
+			ps.Addrs = append(ps.Addrs, uaStr)
+			if as.curAddr == i {
+				ps.CurAddr = uaStr
+			}
+		}
+		if as.roamAddr != nil {
+			ps.CurAddr = udpAddrDebugString(*as.roamAddr)
+		}
+		sb.AddPeer(k, ps)
+	}
+
+	c.foreachActiveDerpSortedLocked(func(node int, ad activeDerp) {
+		// TODO(bradfitz): add to ipnstate.StatusBuilder
+		//f("<li><b>derp-%v</b>: cr%v,wr%v</li>", node, simpleDur(now.Sub(ad.createTime)), simpleDur(now.Sub(*ad.lastWrite)))
+	})
+}
+
+func udpAddrDebugString(ua net.UDPAddr) string {
+	if ua.IP.Equal(derpMagicIP) {
+		return fmt.Sprintf("derp-%d", ua.Port)
+	}
+	return ua.String()
+}

wgengine/userspace.go

@@ -18,8 +18,10 @@ import (
 	"github.com/tailscale/wireguard-go/device"
 	"github.com/tailscale/wireguard-go/tun"
 	"github.com/tailscale/wireguard-go/wgcfg"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/net/interfaces"
 	"tailscale.com/tailcfg"
+	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/wgengine/filter"
 	"tailscale.com/wgengine/magicsock"
@@ -666,3 +668,21 @@ func (e *userspaceEngine) SetNetInfoCallback(cb NetInfoCallback) {
 func (e *userspaceEngine) SetDERPEnabled(v bool) {
 	e.magicConn.SetDERPEnabled(v)
 }
+
+func (e *userspaceEngine) UpdateStatus(sb *ipnstate.StatusBuilder) {
+	st, err := e.getStatus()
+	if err != nil {
+		e.logf("wgengine: getStatus: %v", err)
+		return
+	}
+	for _, ps := range st.Peers {
+		sb.AddPeer(key.Public(ps.NodeKey), &ipnstate.PeerStatus{
+			RxBytes:       int64(ps.RxBytes),
+			TxBytes:       int64(ps.TxBytes),
+			LastHandshake: ps.LastHandshake,
+			InEngine:      true,
+		})
+	}
+
+	e.magicConn.UpdateStatus(sb)
+}

wgengine/watchdog.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/tailscale/wireguard-go/wgcfg"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/wgengine/filter"
 )
 
@@ -74,6 +75,9 @@ func (e *watchdogEngine) SetFilter(filt *filter.Filter) {
 func (e *watchdogEngine) SetStatusCallback(cb StatusCallback) {
 	e.watchdog("SetStatusCallback", func() { e.wrap.SetStatusCallback(cb) })
 }
+func (e *watchdogEngine) UpdateStatus(sb *ipnstate.StatusBuilder) {
+	e.watchdog("UpdateStatus", func() { e.wrap.UpdateStatus(sb) })
+}
 func (e *watchdogEngine) SetNetInfoCallback(cb NetInfoCallback) {
 	e.watchdog("SetNetInfoCallback", func() { e.wrap.SetNetInfoCallback(cb) })
 }

wgengine/wgengine.go

@@ -11,6 +11,7 @@ import (
 	"github.com/tailscale/wireguard-go/device"
 	"github.com/tailscale/wireguard-go/tun"
 	"github.com/tailscale/wireguard-go/wgcfg"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 	"tailscale.com/wgengine/filter"
@@ -29,6 +30,8 @@ type PeerStatus struct {
 }
 
 // Status is the Engine status.
+//
+// TODO(bradfitz): remove this, subset of ipnstate? Need to migrate users.
 type Status struct {
 	Peers      []PeerStatus
 	LocalAddrs []string // TODO(crawshaw): []wgcfg.Endpoint?
@@ -144,4 +147,8 @@ type Engine interface {
 	// SetNetInfoCallback sets the function to call when a
 	// new NetInfo summary is available.
 	SetNetInfoCallback(NetInfoCallback)
+
+	// UpdateStatus populates the network state using the provided
+	// status builder.
+	UpdateStatus(*ipnstate.StatusBuilder)
 }