Update dependencies

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

@@ -0,0 +1,97 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !ios && !js
+
+package magicsock
+
+import (
+	"log"
+	"net/netip"
+	"strings"
+	"sync"
+
+	"tailscale.com/envknob"
+)
+
+// Various debugging and experimental tweakables, set by environment
+// variable.
+var (
+	// debugDisco prints verbose logs of active discovery events as
+	// they happen.
+	debugDisco = envknob.RegisterBool("TS_DEBUG_DISCO")
+	// debugPeerMap prints verbose logs of changes to the peermap.
+	debugPeerMap = envknob.RegisterBool("TS_DEBUG_MAGICSOCK_PEERMAP")
+	// debugOmitLocalAddresses removes all local interface addresses
+	// from magicsock's discovered local endpoints. Used in some tests.
+	debugOmitLocalAddresses = envknob.RegisterBool("TS_DEBUG_OMIT_LOCAL_ADDRS")
+	// logDerpVerbose logs all received DERP packets, including their
+	// full payload.
+	logDerpVerbose = envknob.RegisterBool("TS_DEBUG_DERP")
+	// debugReSTUNStopOnIdle unconditionally enables the "shut down
+	// STUN if magicsock is idle" behavior that normally only triggers
+	// on mobile devices, lowers the shutdown interval, and logs more
+	// verbosely about idle measurements.
+	debugReSTUNStopOnIdle = envknob.RegisterBool("TS_DEBUG_RESTUN_STOP_ON_IDLE")
+	// debugAlwaysDERP disables the use of UDP, forcing all peer communication over DERP.
+	debugAlwaysDERP = envknob.RegisterBool("TS_DEBUG_ALWAYS_USE_DERP")
+	// debugDERPAddr sets the derp address manually, overriding the DERP map from control.
+	debugUseDERPAddr = envknob.RegisterString("TS_DEBUG_USE_DERP_ADDR")
+	// debugDERPUseHTTP tells clients to connect to DERP via HTTP on port 3340 instead of
+	// HTTPS on 443.
+	debugUseDERPHTTP = envknob.RegisterBool("TS_DEBUG_USE_DERP_HTTP")
+	// debugEnableSilentDisco disables the use of heartbeatTimer on the endpoint struct
+	// and attempts to handle disco silently. See issue #540 for details.
+	debugEnableSilentDisco = envknob.RegisterBool("TS_DEBUG_ENABLE_SILENT_DISCO")
+	// debugSendCallMeUnknownPeer sends a CallMeMaybe to a non-existent destination every
+	// time we send a real CallMeMaybe to test the PeerGoneNotHere logic.
+	debugSendCallMeUnknownPeer = envknob.RegisterBool("TS_DEBUG_SEND_CALLME_UNKNOWN_PEER")
+	// debugBindSocket prints extra debugging about socket rebinding in magicsock.
+	debugBindSocket = envknob.RegisterBool("TS_DEBUG_MAGICSOCK_BIND_SOCKET")
+	// debugRingBufferMaxSizeBytes overrides the default size of the endpoint
+	// history ringbuffer.
+	debugRingBufferMaxSizeBytes = envknob.RegisterInt("TS_DEBUG_MAGICSOCK_RING_BUFFER_MAX_SIZE_BYTES")
+	// debugEnablePMTUD enables the peer MTU feature, which does path MTU
+	// discovery on UDP connections between peers. Currently (2023-09-05)
+	// this only turns on the don't fragment bit for the magicsock UDP
+	// sockets.
+	//
+	//lint:ignore U1000 used on Linux/Darwin only
+	debugEnablePMTUD = envknob.RegisterOptBool("TS_DEBUG_ENABLE_PMTUD")
+	// debugPMTUD prints extra debugging about peer MTU path discovery.
+	//
+	//lint:ignore U1000 used on Linux/Darwin only
+	debugPMTUD = envknob.RegisterBool("TS_DEBUG_PMTUD")
+	// Hey you! Adding a new debugknob? Make sure to stub it out in the
+	// debugknobs_stubs.go file too.
+)
+
+// inTest reports whether the running program is a test that set the
+// IN_TS_TEST environment variable.
+//
+// Unlike the other debug tweakables above, this one needs to be
+// checked every time at runtime, because tests set this after program
+// startup.
+func inTest() bool { return envknob.Bool("IN_TS_TEST") }
+
+// pretendpoints returns TS_DEBUG_PRETENDPOINT as []AddrPort, if set.
+// See https://github.com/tailscale/tailscale/issues/12578 and
+// https://github.com/tailscale/tailscale/pull/12735.
+//
+// It can be between 0 and 3 comma-separated AddrPorts.
+var pretendpoints = sync.OnceValue(func() (ret []netip.AddrPort) {
+	all := envknob.String("TS_DEBUG_PRETENDPOINT")
+	const max = 3
+	remain := all
+	for remain != "" && len(ret) < max {
+		var s string
+		s, remain, _ = strings.Cut(remain, ",")
+		ap, err := netip.ParseAddrPort(s)
+		if err != nil {
+			log.Printf("ignoring invalid AddrPort %q in TS_DEBUG_PRETENDPOINT %q: %v", s, all, err)
+			continue
+		}
+		ret = append(ret, ap)
+	}
+	return
+})