wgengine/magicsock: add clientmetric for Peer Relay challenge reception (tailscale#16834)

jwhited · web-flow · commit cde65dba16a2 · 2025-08-11T14:53:25.000-07:00
Updates tailscale/corp#30527 Signed-off-by: Jordan Whited <jordan@tailscale.com>
diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
@@ -2273,6 +2273,7 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake
 			return
 		}
 		c.relayManager.handleRxDiscoMsg(c, challenge, key.NodePublic{}, di.discoKey, src)
+		metricRecvDiscoBindUDPRelayEndpointChallenge.Add(1)
 		return
 	}
 
@@ -4008,6 +4009,7 @@ var (
 	metricRecvDiscoCallMeMaybeViaBadNode                 = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_node")
 	metricRecvDiscoCallMeMaybeBadDisco                   = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_disco")
 	metricRecvDiscoCallMeMaybeViaBadDisco                = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_disco")
+	metricRecvDiscoBindUDPRelayEndpointChallenge         = clientmetric.NewCounter("magicsock_disco_recv_bind_udp_relay_endpoint_challenge")
 	metricRecvDiscoAllocUDPRelayEndpointRequest          = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request")
 	metricRecvDiscoAllocUDPRelayEndpointRequestBadDisco  = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request_bad_disco")
 	metricRecvDiscoAllocUDPRelayEndpointResponseBadDisco = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_response_bad_disco")

Original file line number	Diff line number	Diff line change
`@@ -2273,6 +2273,7 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake`
`2273`	`2273`	`return`
`2274`	`2274`	`}`
`2275`	`2275`	`c.relayManager.handleRxDiscoMsg(c, challenge, key.NodePublic{}, di.discoKey, src)`
	`2276`	`+ metricRecvDiscoBindUDPRelayEndpointChallenge.Add(1)`
`2276`	`2277`	`return`
`2277`	`2278`	`}`
`2278`	`2279`
`@@ -4008,6 +4009,7 @@ var (`
`4008`	`4009`	`metricRecvDiscoCallMeMaybeViaBadNode = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_node")`
`4009`	`4010`	`metricRecvDiscoCallMeMaybeBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_disco")`
`4010`	`4011`	`metricRecvDiscoCallMeMaybeViaBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_disco")`
	`4012`	`+ metricRecvDiscoBindUDPRelayEndpointChallenge = clientmetric.NewCounter("magicsock_disco_recv_bind_udp_relay_endpoint_challenge")`
`4011`	`4013`	`metricRecvDiscoAllocUDPRelayEndpointRequest = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request")`
`4012`	`4014`	`metricRecvDiscoAllocUDPRelayEndpointRequestBadDisco = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request_bad_disco")`
`4013`	`4015`	`metricRecvDiscoAllocUDPRelayEndpointResponseBadDisco = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_response_bad_disco")`