webnet/tailscale
1
0
Fork 0
Code Issues 1 Pull Requests Packages Projects Releases Wiki Activity

wgengine,ipn/ipnlocal,tsnet,cmd/tailscaled: remove PeerForIP from the Engine interface

Browse Source 
Engine.PeerForIP was pure delegation to the callback that LocalBackend
installs via SetPeerForIPFunc, so external callers going through the
engine were taking a pointless round trip: LocalBackend called
b.e.PeerForIP, which called right back into LocalBackend, and the
netstack UseNetstackForIP hooks in tsnet and tailscaled did the same
dance one layer removed.

Export LocalBackend.PeerForIP and make those callers use it directly.
The engine-internal cold paths (Ping, TSMP disco advertisements,
pendopen diagnostics) still need the lookup and have no netmap of
their own, so SetPeerForIPFunc stays on the interface, but the lookup
method itself is now unexported and gone from the Engine interface.
In tailscaled the UseNetstackForIP hook moves from netstack setup to
just after the LocalBackend is created, since the backend doesn't
exist yet when netstack is wired up.

Updates #12542

Change-Id: Ib1e1a4fa5c84ee0dcb9ce5d1910047f2bab9453c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2026-07-13 15:15:16 -07:00
committed by Brad Fitzpatrick
parent c436dec43c
commit 9cb1147805
10 changed files with 43 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files
wgengine/userspace.go
+13 -13
View File
@@ -103,10 +103,10 @@ type userspaceEngine struct {
wgLock sync.Mutex // serializes all wgdev operations; see lock order comment below
// peerForIP, if non-nil, is the callback installed via
// [userspaceEngine.SetPeerForIPFunc]. PeerForIP delegates to it
// peerForIPFn, if non-nil, is the callback installed via
// [userspaceEngine.SetPeerForIPFunc]. peerForIP delegates to it
// for the cold-path control lookups (Ping, TSMP, pendopen, etc).
peerForIP atomic.Pointer[func(netip.Addr) (_ PeerForIP, ok bool)]
peerForIPFn atomic.Pointer[func(netip.Addr) (_ PeerForIP, ok bool)]
// peerConfigFn, if non-nil, is the live per-peer allowed-IPs
// source installed via [userspaceEngine.SetPeerConfigFunc]. When
@@ -605,7 +605,7 @@ func NewUserspaceEngine(logf logger.Logf, conf Config) (_ Engine, reterr error)
pkt := packet.TSMPDiscoKeyAdvertisement{
Key: update.Key,
}
peer, ok := e.PeerForIP(update.Src)
peer, ok := e.peerForIP(update.Src)
if !ok {
e.logf("wgengine: no peer found for %v", update.Src)
return
@@ -1388,7 +1388,7 @@ func (e *userspaceEngine) UpdateStatus(sb *ipnstate.StatusBuilder) {
func (e *userspaceEngine) Ping(ip netip.Addr, pingType tailcfg.PingType, size int, cb func(*ipnstate.PingResult)) {
res := &ipnstate.PingResult{IP: ip.String()}
pip, ok := e.PeerForIP(ip)
pip, ok := e.peerForIP(ip)
if !ok {
e.logf("ping(%v): no matching peer", ip)
res.Err = "no matching peer"
@@ -1585,24 +1585,24 @@ func (e *userspaceEngine) ProbeLocks() {
e.wgLock.Unlock()
}
// SetPeerForIPFunc installs the callback used by [userspaceEngine.PeerForIP].
// SetPeerForIPFunc installs the callback used by [userspaceEngine.peerForIP].
// See [Engine.SetPeerForIPFunc].
func (e *userspaceEngine) SetPeerForIPFunc(fn func(netip.Addr) (PeerForIP, bool)) {
if fn == nil {
e.peerForIP.Store(nil)
e.peerForIPFn.Store(nil)
return
}
e.peerForIP.Store(&fn)
e.peerForIPFn.Store(&fn)
}
// PeerForIP returns the node responsible for handling the given IP.
// It delegates to the callback installed via [SetPeerForIPFunc]; engines
// without an installed callback return (zero, false).
func (e *userspaceEngine) PeerForIP(ip netip.Addr) (ret PeerForIP, ok bool) {
// peerForIP returns the node responsible for handling the given IP.
// It delegates to the callback installed via [Engine.SetPeerForIPFunc];
// engines without an installed callback return (zero, false).
func (e *userspaceEngine) peerForIP(ip netip.Addr) (ret PeerForIP, ok bool) {
if !ip.IsValid() {
return ret, false
}
if fn := e.peerForIP.Load(); fn != nil {
if fn := e.peerForIPFn.Load(); fn != nil {
return (*fn)(ip)
}
return ret, false