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>

cmd/tailscale/depaware.txt

@@ -7,16 +7,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
    L    github.com/mdlayher/sdnotify                                 from tailscale.com/util/systemd
         github.com/peterbourgon/ff/v2                                from github.com/peterbourgon/ff/v2/ffcli
         github.com/peterbourgon/ff/v2/ffcli                          from tailscale.com/cmd/tailscale/cli
-     💣 github.com/tailscale/wireguard-go/conn                       from github.com/tailscale/wireguard-go/device
-     💣 github.com/tailscale/wireguard-go/device                     from tailscale.com/wgengine/wgcfg
-     💣 github.com/tailscale/wireguard-go/ipc                        from github.com/tailscale/wireguard-go/device
-   W 💣 github.com/tailscale/wireguard-go/ipc/winpipe                from github.com/tailscale/wireguard-go/ipc
-        github.com/tailscale/wireguard-go/ratelimiter                from github.com/tailscale/wireguard-go/device
-        github.com/tailscale/wireguard-go/replay                     from github.com/tailscale/wireguard-go/device
-        github.com/tailscale/wireguard-go/rwcancel                   from github.com/tailscale/wireguard-go/device+
-        github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device
-     💣 github.com/tailscale/wireguard-go/tun                        from github.com/tailscale/wireguard-go/device
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun                 from github.com/tailscale/wireguard-go/tun
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
         github.com/toqueteos/webbrowser                              from tailscale.com/cmd/tailscale/cli
      💣 go4.org/intern                                               from inet.af/netaddr
@@ -45,7 +35,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/net/packet                                     from tailscale.com/wgengine/filter
         tailscale.com/net/stun                                       from tailscale.com/net/netcheck
         tailscale.com/net/tlsdial                                    from tailscale.com/control/controlclient+
-        tailscale.com/net/tsaddr                                     from tailscale.com/net/interfaces+
+        tailscale.com/net/tsaddr                                     from tailscale.com/net/interfaces
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/control/controlclient+
         tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli
         tailscale.com/safesocket                                     from tailscale.com/cmd/tailscale/cli
@@ -67,9 +57,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/version                                        from tailscale.com/cmd/tailscale/cli+
         tailscale.com/version/distro                                 from tailscale.com/cmd/tailscale/cli+
         tailscale.com/wgengine/filter                                from tailscale.com/control/controlclient
-        tailscale.com/wgengine/wgcfg                                 from tailscale.com/control/controlclient
         golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/blake2s                                  from github.com/tailscale/wireguard-go/device
         golang.org/x/crypto/chacha20                                 from golang.org/x/crypto/chacha20poly1305
         golang.org/x/crypto/chacha20poly1305                         from crypto/tls+
         golang.org/x/crypto/cryptobyte                               from crypto/ecdsa+
@@ -78,17 +66,14 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         golang.org/x/crypto/hkdf                                     from crypto/tls
         golang.org/x/crypto/nacl/box                                 from tailscale.com/control/controlclient+
         golang.org/x/crypto/nacl/secretbox                           from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/poly1305                                 from github.com/tailscale/wireguard-go/device+
+        golang.org/x/crypto/poly1305                                 from golang.org/x/crypto/chacha20poly1305+
         golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
-        golang.org/x/net/bpf                                         from golang.org/x/net/ipv4+
         golang.org/x/net/context/ctxhttp                             from golang.org/x/oauth2/internal
         golang.org/x/net/dns/dnsmessage                              from net
         golang.org/x/net/http/httpguts                               from net/http
         golang.org/x/net/http/httpproxy                              from net/http
         golang.org/x/net/http2/hpack                                 from net/http
         golang.org/x/net/idna                                        from golang.org/x/net/http/httpguts+
-        golang.org/x/net/ipv4                                        from github.com/tailscale/wireguard-go/device
-        golang.org/x/net/ipv6                                        from github.com/tailscale/wireguard-go/device+
         golang.org/x/net/proxy                                       from tailscale.com/net/netns
    D    golang.org/x/net/route                                       from net
         golang.org/x/oauth2                                          from tailscale.com/control/controlclient+
@@ -96,7 +81,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         golang.org/x/sync/errgroup                                   from tailscale.com/derp
         golang.org/x/sync/singleflight                               from tailscale.com/net/dnscache
         golang.org/x/sys/cpu                                         from golang.org/x/crypto/blake2b+
-  LD    golang.org/x/sys/unix                                        from github.com/tailscale/wireguard-go/conn+
+  LD    golang.org/x/sys/unix                                        from tailscale.com/net/netns+
    W    golang.org/x/sys/windows                                     from github.com/apenwarr/fixconsole+
    W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
@@ -157,7 +142,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         math                                                         from compress/flate+
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
-        math/rand                                                    from github.com/tailscale/wireguard-go/device+
+        math/rand                                                    from math/big+
         mime                                                         from golang.org/x/oauth2/internal+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart

cmd/tailscaled/depaware.txt

@@ -129,7 +129,8 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/wgengine/router/dns                            from tailscale.com/ipn/ipnlocal+
         tailscale.com/wgengine/tsdns                                 from tailscale.com/ipn/ipnlocal+
         tailscale.com/wgengine/tstun                                 from tailscale.com/wgengine+
-        tailscale.com/wgengine/wgcfg                                 from tailscale.com/control/controlclient+
+        tailscale.com/wgengine/wgcfg                                 from tailscale.com/ipn/ipnlocal+
+        tailscale.com/wgengine/wgcfg/nmcfg                           from tailscale.com/ipn/ipnlocal
         tailscale.com/wgengine/wglog                                 from tailscale.com/wgengine
    W 💣 tailscale.com/wgengine/winnet                                from tailscale.com/wgengine/router
         golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box

control/controlclient/netmap.go

@@ -7,19 +7,14 @@ package controlclient
 import (
 	"encoding/json"
 	"fmt"
-	"net"
 	"reflect"
-	"strconv"
 	"strings"
 	"time"
 
 	"inet.af/netaddr"
-	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
-	"tailscale.com/types/logger"
 	"tailscale.com/types/wgkey"
 	"tailscale.com/wgengine/filter"
-	"tailscale.com/wgengine/wgcfg"
 )
 
 type NetworkMap struct {
@@ -252,118 +247,6 @@ const (
 	AllowSubnetRoutes
 )
 
-// EndpointDiscoSuffix is appended to the hex representation of a peer's discovery key
-// and is then the sole wireguard endpoint for peers with a non-zero discovery key.
-// This form is then recognize by magicsock's CreateEndpoint.
-const EndpointDiscoSuffix = ".disco.tailscale:12345"
-
-// WGCfg returns the NetworkMaps's Wireguard configuration.
-func (nm *NetworkMap) WGCfg(logf logger.Logf, flags WGConfigFlags) (*wgcfg.Config, error) {
-	cfg := &wgcfg.Config{
-		Name:       "tailscale",
-		PrivateKey: wgcfg.PrivateKey(nm.PrivateKey),
-		Addresses:  nm.Addresses,
-		ListenPort: nm.LocalPort,
-		Peers:      make([]wgcfg.Peer, 0, len(nm.Peers)),
-	}
-
-	for _, peer := range nm.Peers {
-		if Debug.OnlyDisco && peer.DiscoKey.IsZero() {
-			continue
-		}
-		cfg.Peers = append(cfg.Peers, wgcfg.Peer{
-			PublicKey: wgcfg.Key(peer.Key),
-		})
-		cpeer := &cfg.Peers[len(cfg.Peers)-1]
-		if peer.KeepAlive {
-			cpeer.PersistentKeepalive = 25 // seconds
-		}
-
-		if !peer.DiscoKey.IsZero() {
-			if err := appendEndpoint(cpeer, fmt.Sprintf("%x%s", peer.DiscoKey[:], EndpointDiscoSuffix)); err != nil {
-				return nil, err
-			}
-			cpeer.Endpoints = fmt.Sprintf("%x.disco.tailscale:12345", peer.DiscoKey[:])
-		} else {
-			if err := appendEndpoint(cpeer, peer.DERP); err != nil {
-				return nil, err
-			}
-			for _, ep := range peer.Endpoints {
-				if err := appendEndpoint(cpeer, ep); err != nil {
-					return nil, err
-				}
-			}
-		}
-
-		for _, allowedIP := range peer.AllowedIPs {
-			if allowedIP.IsSingleIP() && tsaddr.IsTailscaleIP(allowedIP.IP) && (flags&AllowSingleHosts) == 0 {
-				logf("[v1] wgcfg: skipping node IP %v from %q (%v)",
-					allowedIP.IP, nodeDebugName(peer), peer.Key.ShortString())
-				continue
-			} else if cidrIsSubnet(peer, allowedIP) {
-				if (flags & AllowSubnetRoutes) == 0 {
-					logf("[v1] wgcfg: not accepting subnet route %v from %q (%v)",
-						allowedIP, nodeDebugName(peer), peer.Key.ShortString())
-					continue
-				}
-			}
-			cpeer.AllowedIPs = append(cpeer.AllowedIPs, allowedIP)
-		}
-	}
-
-	return cfg, nil
-}
-
-func nodeDebugName(n *tailcfg.Node) string {
-	name := n.Name
-	if name == "" {
-		name = n.Hostinfo.Hostname
-	}
-	if i := strings.Index(name, "."); i != -1 {
-		name = name[:i]
-	}
-	if name == "" && len(n.Addresses) != 0 {
-		return n.Addresses[0].String()
-	}
-	return name
-}
-
-// cidrIsSubnet reports whether cidr is a non-default-route subnet
-// exported by node that is not one of its own self addresses.
-func cidrIsSubnet(node *tailcfg.Node, cidr netaddr.IPPrefix) bool {
-	if cidr.Bits == 0 {
-		return false
-	}
-	if !cidr.IsSingleIP() {
-		return true
-	}
-	for _, selfCIDR := range node.Addresses {
-		if cidr == selfCIDR {
-			return false
-		}
-	}
-	return true
-}
-
-func appendEndpoint(peer *wgcfg.Peer, epStr string) error {
-	if epStr == "" {
-		return nil
-	}
-	_, port, err := net.SplitHostPort(epStr)
-	if err != nil {
-		return fmt.Errorf("malformed endpoint %q for peer %v", epStr, peer.PublicKey.ShortString())
-	}
-	_, err = strconv.ParseUint(port, 10, 16)
-	if err != nil {
-		return fmt.Errorf("invalid port in endpoint %q for peer %v", epStr, peer.PublicKey.ShortString())
-	}
-	if peer.Endpoints != "" {
-		peer.Endpoints += ","
-	}
-	peer.Endpoints += epStr
-	return nil
-}
-
 // eqStringsIgnoreNil reports whether a and b have the same length and
 // contents, but ignore whether a or b are nil.
 func eqStringsIgnoreNil(a, b []string) bool {

ipn/ipnlocal/local.go

@@ -38,6 +38,7 @@ import (
 	"tailscale.com/wgengine/router/dns"
 	"tailscale.com/wgengine/tsdns"
 	"tailscale.com/wgengine/wgcfg"
+	"tailscale.com/wgengine/wgcfg/nmcfg"
 )
 
 var controlDebugFlags = getControlDebugFlags()
@@ -1268,7 +1269,7 @@ func (b *LocalBackend) authReconfig() {
 		}
 	}
 
-	cfg, err := nm.WGCfg(b.logf, flags)
+	cfg, err := nmcfg.WGCfg(nm, b.logf, flags)
 	if err != nil {
 		b.logf("wgcfg: %v", err)
 		return

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.

wgengine/wgcfg/config.go

@@ -9,6 +9,11 @@ import (
 	"inet.af/netaddr"
 )
 
+// EndpointDiscoSuffix is appended to the hex representation of a peer's discovery key
+// and is then the sole wireguard endpoint for peers with a non-zero discovery key.
+// This form is then recognize by magicsock's CreateEndpoint.
+const EndpointDiscoSuffix = ".disco.tailscale:12345"
+
 // Config is a WireGuard configuration.
 // It only supports the set of things Tailscale uses.
 type Config struct {

wgengine/wgcfg/nmcfg/nmcfg.go

@@ -0,0 +1,126 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package nmcfg converts a controlclient.NetMap into a wgcfg config.
+package nmcfg
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+
+	"inet.af/netaddr"
+	"tailscale.com/control/controlclient"
+	"tailscale.com/net/tsaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/logger"
+	"tailscale.com/wgengine/wgcfg"
+)
+
+func nodeDebugName(n *tailcfg.Node) string {
+	name := n.Name
+	if name == "" {
+		name = n.Hostinfo.Hostname
+	}
+	if i := strings.Index(name, "."); i != -1 {
+		name = name[:i]
+	}
+	if name == "" && len(n.Addresses) != 0 {
+		return n.Addresses[0].String()
+	}
+	return name
+}
+
+// cidrIsSubnet reports whether cidr is a non-default-route subnet
+// exported by node that is not one of its own self addresses.
+func cidrIsSubnet(node *tailcfg.Node, cidr netaddr.IPPrefix) bool {
+	if cidr.Bits == 0 {
+		return false
+	}
+	if !cidr.IsSingleIP() {
+		return true
+	}
+	for _, selfCIDR := range node.Addresses {
+		if cidr == selfCIDR {
+			return false
+		}
+	}
+	return true
+}
+
+// WGCfg returns the NetworkMaps's Wireguard configuration.
+func WGCfg(nm *controlclient.NetworkMap, logf logger.Logf, flags controlclient.WGConfigFlags) (*wgcfg.Config, error) {
+	cfg := &wgcfg.Config{
+		Name:       "tailscale",
+		PrivateKey: wgcfg.PrivateKey(nm.PrivateKey),
+		Addresses:  nm.Addresses,
+		ListenPort: nm.LocalPort,
+		Peers:      make([]wgcfg.Peer, 0, len(nm.Peers)),
+	}
+
+	for _, peer := range nm.Peers {
+		if controlclient.Debug.OnlyDisco && peer.DiscoKey.IsZero() {
+			continue
+		}
+		cfg.Peers = append(cfg.Peers, wgcfg.Peer{
+			PublicKey: wgcfg.Key(peer.Key),
+		})
+		cpeer := &cfg.Peers[len(cfg.Peers)-1]
+		if peer.KeepAlive {
+			cpeer.PersistentKeepalive = 25 // seconds
+		}
+
+		if !peer.DiscoKey.IsZero() {
+			if err := appendEndpoint(cpeer, fmt.Sprintf("%x%s", peer.DiscoKey[:], wgcfg.EndpointDiscoSuffix)); err != nil {
+				return nil, err
+			}
+			cpeer.Endpoints = fmt.Sprintf("%x.disco.tailscale:12345", peer.DiscoKey[:])
+		} else {
+			if err := appendEndpoint(cpeer, peer.DERP); err != nil {
+				return nil, err
+			}
+			for _, ep := range peer.Endpoints {
+				if err := appendEndpoint(cpeer, ep); err != nil {
+					return nil, err
+				}
+			}
+		}
+		for _, allowedIP := range peer.AllowedIPs {
+			if allowedIP.IsSingleIP() && tsaddr.IsTailscaleIP(allowedIP.IP) && (flags&controlclient.AllowSingleHosts) == 0 {
+				logf("[v1] wgcfg: skipping node IP %v from %q (%v)",
+					allowedIP.IP, nodeDebugName(peer), peer.Key.ShortString())
+				continue
+			} else if cidrIsSubnet(peer, allowedIP) {
+				if (flags & controlclient.AllowSubnetRoutes) == 0 {
+					logf("[v1] wgcfg: not accepting subnet route %v from %q (%v)",
+						allowedIP, nodeDebugName(peer), peer.Key.ShortString())
+					continue
+				}
+			}
+			cpeer.AllowedIPs = append(cpeer.AllowedIPs, allowedIP)
+		}
+	}
+
+	return cfg, nil
+}
+
+func appendEndpoint(peer *wgcfg.Peer, epStr string) error {
+	if epStr == "" {
+		return nil
+	}
+	_, port, err := net.SplitHostPort(epStr)
+	if err != nil {
+		return fmt.Errorf("malformed endpoint %q for peer %v", epStr, peer.PublicKey.ShortString())
+	}
+	_, err = strconv.ParseUint(port, 10, 16)
+	if err != nil {
+		return fmt.Errorf("invalid port in endpoint %q for peer %v", epStr, peer.PublicKey.ShortString())
+	}
+	if peer.Endpoints != "" {
+		peer.Endpoints += ","
+	}
+	peer.Endpoints += epStr
+	return nil
+}