net/portmapper: retry UPnP when we get an "Invalid Args"

We previously retried getting a UPnP mapping when the device returned
error code 725, "OnlyPermanentLeasesSupported". However, we've seen
devices in the wild also return 402, "Invalid Args", when given a lease
duration. Fall back to the no-duration mapping method in these cases.

Updates #15223

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I6a25007c9eeac0dac83750dd3ae9bfcc287c8fcf

net/portmapper/upnp.go

@@ -610,8 +610,9 @@ func (c *Client) tryUPnPPortmapWithDevice(
 		}
 
 		// From the UPnP spec: http://upnp.org/specs/gw/UPnP-gw-WANIPConnection-v2-Service.pdf
+		//     402: Invalid Args (see: https://github.com/tailscale/tailscale/issues/15223)
 		//     725: OnlyPermanentLeasesSupported
-		if ok && code == 725 {
+		if ok && (code == 402 || code == 725) {
 			newPort, err = addAnyPortMapping(
 				ctx,
 				client,
@@ -620,7 +621,7 @@ func (c *Client) tryUPnPPortmapWithDevice(
 				internal.Addr().String(),
 				0, // permanent
 			)
-			c.vlogf("addAnyPortMapping: 725 retry %v, err=%q", newPort, err)
+			c.vlogf("addAnyPortMapping: errcode=%d retried: port=%v err=%v", code, newPort, err)
 		}
 	}
 	if err != nil {