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tailscale/wgengine/magicsock/peermap.go

209 lines
5.9 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package magicsock
import (
"net/netip"
"tailscale.com/tailcfg"
"tailscale.com/types/key"
"tailscale.com/util/set"
)
// peerInfo is all the information magicsock tracks about a particular
// peer.
type peerInfo struct {
ep *endpoint // always non-nil.
// ipPorts is an inverted version of peerMap.byIPPort (below), so
// that when we're deleting this node, we can rapidly find out the
// keys that need deleting from peerMap.byIPPort without having to
// iterate over every IPPort known for any peer.
ipPorts set.Set[netip.AddrPort]
}
func newPeerInfo(ep *endpoint) *peerInfo {
return &peerInfo{
ep: ep,
ipPorts: set.Set[netip.AddrPort]{},
}
}
// peerMap is an index of peerInfos by node (WireGuard) key, disco
// key, and discovered ip:port endpoints.
//
// It doesn't do any locking; all access must be done with Conn.mu held.
type peerMap struct {
byNodeKey map[key.NodePublic]*peerInfo
byIPPort map[netip.AddrPort]*peerInfo
byNodeID map[tailcfg.NodeID]*peerInfo
// nodesOfDisco contains the set of nodes that are using a
// DiscoKey. Usually those sets will be just one node.
nodesOfDisco map[key.DiscoPublic]set.Set[key.NodePublic]
}
func newPeerMap() peerMap {
return peerMap{
byNodeKey: map[key.NodePublic]*peerInfo{},
byIPPort: map[netip.AddrPort]*peerInfo{},
byNodeID: map[tailcfg.NodeID]*peerInfo{},
nodesOfDisco: map[key.DiscoPublic]set.Set[key.NodePublic]{},
}
}
// nodeCount returns the number of nodes currently in m.
func (m *peerMap) nodeCount() int {
if len(m.byNodeKey) != len(m.byNodeID) {
devPanicf("internal error: peerMap.byNodeKey and byNodeID out of sync")
}
return len(m.byNodeKey)
}
// anyEndpointForDiscoKey reports whether there exists any
// peers in the netmap with dk as their DiscoKey.
func (m *peerMap) anyEndpointForDiscoKey(dk key.DiscoPublic) bool {
return len(m.nodesOfDisco[dk]) > 0
}
// endpointForNodeKey returns the endpoint for nk, or nil if
// nk is not known to us.
func (m *peerMap) endpointForNodeKey(nk key.NodePublic) (ep *endpoint, ok bool) {
if nk.IsZero() {
return nil, false
}
if info, ok := m.byNodeKey[nk]; ok {
return info.ep, true
}
return nil, false
}
// endpointForNodeID returns the endpoint for nodeID, or nil if
// nodeID is not known to us.
func (m *peerMap) endpointForNodeID(nodeID tailcfg.NodeID) (ep *endpoint, ok bool) {
if info, ok := m.byNodeID[nodeID]; ok {
return info.ep, true
}
return nil, false
}
// endpointForIPPort returns the endpoint for the peer we
// believe to be at ipp, or nil if we don't know of any such peer.
func (m *peerMap) endpointForIPPort(ipp netip.AddrPort) (ep *endpoint, ok bool) {
if info, ok := m.byIPPort[ipp]; ok {
return info.ep, true
}
return nil, false
}
// forEachEndpoint invokes f on every endpoint in m.
func (m *peerMap) forEachEndpoint(f func(ep *endpoint)) {
for _, pi := range m.byNodeKey {
f(pi.ep)
}
}
// forEachEndpointWithDiscoKey invokes f on every endpoint in m that has the
// provided DiscoKey until f returns false or there are no endpoints left to
// iterate.
func (m *peerMap) forEachEndpointWithDiscoKey(dk key.DiscoPublic, f func(*endpoint) (keepGoing bool)) {
for nk := range m.nodesOfDisco[dk] {
pi, ok := m.byNodeKey[nk]
if !ok {
// Unexpected. Data structures would have to
// be out of sync. But we don't have a logger
// here to log [unexpected], so just skip.
// Maybe log later once peerMap is merged back
// into Conn.
continue
}
if !f(pi.ep) {
return
}
}
}
// upsertEndpoint stores endpoint in the peerInfo for
// ep.publicKey, and updates indexes. m must already have a
// tailcfg.Node for ep.publicKey.
func (m *peerMap) upsertEndpoint(ep *endpoint, oldDiscoKey key.DiscoPublic) {
if ep.nodeID == 0 {
panic("internal error: upsertEndpoint called with zero NodeID")
}
pi, ok := m.byNodeKey[ep.publicKey]
if !ok {
pi = newPeerInfo(ep)
m.byNodeKey[ep.publicKey] = pi
}
m.byNodeID[ep.nodeID] = pi
epDisco := ep.disco.Load()
if epDisco == nil || oldDiscoKey != epDisco.key {
delete(m.nodesOfDisco[oldDiscoKey], ep.publicKey)
}
if ep.isWireguardOnly {
// If the peer is a WireGuard only peer, add all of its endpoints.
// TODO(raggi,catzkorn): this could mean that if a "isWireguardOnly"
// peer has, say, 192.168.0.2 and so does a tailscale peer, the
// wireguard one will win. That may not be the outcome that we want -
// perhaps we should prefer bestAddr.AddrPort if it is set?
// see tailscale/tailscale#7994
for ipp := range ep.endpointState {
m.setNodeKeyForIPPort(ipp, ep.publicKey)
}
return
}
discoSet := m.nodesOfDisco[epDisco.key]
if discoSet == nil {
discoSet = set.Set[key.NodePublic]{}
m.nodesOfDisco[epDisco.key] = discoSet
}
discoSet.Add(ep.publicKey)
}
// setNodeKeyForIPPort makes future peer lookups by ipp return the
// same endpoint as a lookup by nk.
//
// This should only be called with a fully verified mapping of ipp to
// nk, because calling this function defines the endpoint we hand to
// WireGuard for packets received from ipp.
func (m *peerMap) setNodeKeyForIPPort(ipp netip.AddrPort, nk key.NodePublic) {
if pi := m.byIPPort[ipp]; pi != nil {
delete(pi.ipPorts, ipp)
delete(m.byIPPort, ipp)
}
if pi, ok := m.byNodeKey[nk]; ok {
pi.ipPorts.Add(ipp)
m.byIPPort[ipp] = pi
}
}
// deleteEndpoint deletes the peerInfo associated with ep, and
// updates indexes.
func (m *peerMap) deleteEndpoint(ep *endpoint) {
if ep == nil {
return
}
ep.stopAndReset()
epDisco := ep.disco.Load()
pi := m.byNodeKey[ep.publicKey]
if epDisco != nil {
delete(m.nodesOfDisco[epDisco.key], ep.publicKey)
}
delete(m.byNodeKey, ep.publicKey)
if was, ok := m.byNodeID[ep.nodeID]; ok && was.ep == ep {
delete(m.byNodeID, ep.nodeID)
}
if pi == nil {
// Kneejerk paranoia from earlier issue 2801.
// Unexpected. But no logger plumbed here to log so.
return
}
for ip := range pi.ipPorts {
delete(m.byIPPort, ip)
}
}