wgengine/wgcfg/nmcfg: split control/controlclient/netmap.go into own package

It couldn't move to ipnlocal due to test dependency cycles.

Updates #1278

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

wgengine/magicsock/magicsock.go

@@ -51,6 +51,7 @@ import (
 	"tailscale.com/types/nettype"
 	"tailscale.com/types/wgkey"
 	"tailscale.com/version"
+	"tailscale.com/wgengine/wgcfg"
 )
 
 // Various debugging and experimental tweakables, set by environment
@@ -2643,11 +2644,11 @@ func (c *Conn) CreateEndpoint(pubKey [32]byte, addrs string) (conn.Endpoint, err
 	pk := key.Public(pubKey)
 	c.logf("magicsock: CreateEndpoint: key=%s: %s", pk.ShortString(), derpStr(addrs))
 
-	if !strings.HasSuffix(addrs, controlclient.EndpointDiscoSuffix) {
+	if !strings.HasSuffix(addrs, wgcfg.EndpointDiscoSuffix) {
 		return c.createLegacyEndpointLocked(pk, addrs)
 	}
 
-	discoHex := strings.TrimSuffix(addrs, controlclient.EndpointDiscoSuffix)
+	discoHex := strings.TrimSuffix(addrs, wgcfg.EndpointDiscoSuffix)
 	discoKey, err := key.NewPublicFromHexMem(mem.S(discoHex))
 	if err != nil {
 		return nil, fmt.Errorf("magicsock: invalid discokey endpoint %q for %v: %w", addrs, pk.ShortString(), err)

wgengine/magicsock/magicsock_test.go

@@ -46,6 +46,7 @@ import (
 	"tailscale.com/wgengine/filter"
 	"tailscale.com/wgengine/tstun"
 	"tailscale.com/wgengine/wgcfg"
+	"tailscale.com/wgengine/wgcfg/nmcfg"
 	"tailscale.com/wgengine/wglog"
 )
 
@@ -293,7 +294,7 @@ func meshStacks(logf logger.Logf, ms []*magicStack) (cleanup func()) {
 				peerSet[key.Public(peer.Key)] = struct{}{}
 			}
 			m.conn.UpdatePeers(peerSet)
-			wg, err := netmap.WGCfg(logf, controlclient.AllowSingleHosts)
+			wg, err := nmcfg.WGCfg(netmap, logf, controlclient.AllowSingleHosts)
 			if err != nil {
 				// We're too far from the *testing.T to be graceful,
 				// blow up. Shouldn't happen anyway.