Update dependencies

vendor/tailscale.com/wgengine/magicsock/derp.go

@@ -64,10 +64,30 @@ func (c *Conn) removeDerpPeerRoute(peer key.NodePublic, regionID int, dc *derpht
 // addDerpPeerRoute adds a DERP route entry, noting that peer was seen
 // on DERP node derpID, at least on the connection identified by dc.
 // See issue 150 for details.
-func (c *Conn) addDerpPeerRoute(peer key.NodePublic, derpID int, dc *derphttp.Client) {
+func (c *Conn) addDerpPeerRoute(peer key.NodePublic, regionID int, dc *derphttp.Client) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	mak.Set(&c.derpRoute, peer, derpRoute{derpID, dc})
+	mak.Set(&c.derpRoute, peer, derpRoute{regionID, dc})
+}
+
+// fallbackDERPRegionForPeer returns the DERP region ID we might be able to use
+// to contact peer, learned from observing recent DERP traffic from them.
+//
+// This is used as a fallback when a peer receives a packet from a peer
+// over DERP but doesn't known that peer's home DERP or any UDP endpoints.
+// This is particularly useful for large one-way nodes (such as hello.ts.net)
+// that don't actively reach out to other nodes, so don't need to be told
+// the DERP home of peers. They can instead learn the DERP home upon getting the
+// first connection.
+//
+// This can also help nodes from a slow or misbehaving control plane.
+func (c *Conn) fallbackDERPRegionForPeer(peer key.NodePublic) (regionID int) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if dr, ok := c.derpRoute[peer]; ok {
+		return dr.regionID
+	}
+	return 0
 }
 
 // activeDerp contains fields for an active DERP connection.
@@ -158,10 +178,10 @@ func (c *Conn) maybeSetNearestDERP(report *netcheck.Report) (preferredDERP int)
 	} else {
 		connectedToControl = c.health.GetInPollNetMap()
 	}
+	c.mu.Lock()
+	myDerp := c.myDerp
+	c.mu.Unlock()
 	if !connectedToControl {
-		c.mu.Lock()
-		myDerp := c.myDerp
-		c.mu.Unlock()
 		if myDerp != 0 {
 			metricDERPHomeNoChangeNoControl.Add(1)
 			return myDerp
@@ -178,6 +198,11 @@ func (c *Conn) maybeSetNearestDERP(report *netcheck.Report) (preferredDERP int)
 		// one.
 		preferredDERP = c.pickDERPFallback()
 	}
+	if preferredDERP != myDerp {
+		c.logf(
+			"magicsock: home DERP changing from derp-%d [%dms] to derp-%d [%dms]",
+			c.myDerp, report.RegionLatency[myDerp].Milliseconds(), preferredDERP, report.RegionLatency[preferredDERP].Milliseconds())
+	}
 	if !c.setNearestDERP(preferredDERP) {
 		preferredDERP = 0
 	}
@@ -627,7 +652,7 @@ func (c *Conn) runDerpReader(ctx context.Context, regionID int, dc *derphttp.Cli
 				// Do nothing.
 			case derp.PeerGoneReasonNotHere:
 				metricRecvDiscoDERPPeerNotHere.Add(1)
-				c.logf("[unexpected] magicsock: derp-%d does not know about peer %s, removing route",
+				c.logf("magicsock: derp-%d does not know about peer %s, removing route",
 					regionID, key.NodePublic(m.Peer).ShortString())
 			default:
 				metricRecvDiscoDERPPeerGoneUnknown.Add(1)
@@ -644,9 +669,10 @@ func (c *Conn) runDerpReader(ctx context.Context, regionID int, dc *derphttp.Cli
 }
 
 type derpWriteRequest struct {
-	addr   netip.AddrPort
-	pubKey key.NodePublic
-	b      []byte // copied; ownership passed to receiver
+	addr    netip.AddrPort
+	pubKey  key.NodePublic
+	b       []byte // copied; ownership passed to receiver
+	isDisco bool
 }
 
 // runDerpWriter runs in a goroutine for the life of a DERP
@@ -668,8 +694,12 @@ func (c *Conn) runDerpWriter(ctx context.Context, dc *derphttp.Client, ch <-chan
 			if err != nil {
 				c.logf("magicsock: derp.Send(%v): %v", wr.addr, err)
 				metricSendDERPError.Add(1)
-			} else {
-				metricSendDERP.Add(1)
+				if !wr.isDisco {
+					c.metrics.outboundPacketsDroppedErrors.Add(1)
+				}
+			} else if !wr.isDisco {
+				c.metrics.outboundPacketsDERPTotal.Add(1)
+				c.metrics.outboundBytesDERPTotal.Add(int64(len(wr.b)))
 			}
 		}
 	}
@@ -690,7 +720,6 @@ func (c *connBind) receiveDERP(buffs [][]byte, sizes []int, eps []conn.Endpoint)
 			// No data read occurred. Wait for another packet.
 			continue
 		}
-		metricRecvDataDERP.Add(1)
 		sizes[0] = n
 		eps[0] = ep
 		return 1, nil
@@ -728,8 +757,11 @@ func (c *Conn) processDERPReadResult(dm derpReadResult, b []byte) (n int, ep *en
 
 	ep.noteRecvActivity(ipp, mono.Now())
 	if stats := c.stats.Load(); stats != nil {
-		stats.UpdateRxPhysical(ep.nodeAddr, ipp, dm.n)
+		stats.UpdateRxPhysical(ep.nodeAddr, ipp, 1, dm.n)
 	}
+
+	c.metrics.inboundPacketsDERPTotal.Add(1)
+	c.metrics.inboundBytesDERPTotal.Add(int64(n))
 	return n, ep
 }