mirror of
https://github.com/tailscale/tailscale.git
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91 lines
2.4 KiB
Go
91 lines
2.4 KiB
Go
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// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package table provides a Routing Table implementation which allows
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// looking up the peer that should be used to route a given IP address.
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package table
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import (
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"net/netip"
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"tailscale.com/tempfork/device"
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"tailscale.com/types/key"
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"tailscale.com/util/mak"
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)
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// RoutingTableBuilder is a builder for a RoutingTable.
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// It is not safe for concurrent use.
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type RoutingTableBuilder struct {
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// peers is a map from node public key to the peer that owns that key.
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// It is only used to handle insertions and deletions.
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peers map[key.NodePublic]*device.Peer
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// prefixTrie is a trie of prefixes which facilitates looking up the
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// peer that owns a given IP address.
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prefixTrie *device.AllowedIPs
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}
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// Remove removes the given peer from the routing table.
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func (t *RoutingTableBuilder) Remove(peer key.NodePublic) {
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p, ok := t.peers[peer]
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if !ok {
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return
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}
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t.prefixTrie.RemoveByPeer(p)
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delete(t.peers, peer)
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}
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// InsertOrReplace inserts the given peer and prefixes into the routing table.
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func (t *RoutingTableBuilder) InsertOrReplace(peer key.NodePublic, pfxs ...netip.Prefix) {
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p, ok := t.peers[peer]
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if !ok {
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p = device.NewPeer(peer)
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mak.Set(&t.peers, peer, p)
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} else {
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t.prefixTrie.RemoveByPeer(p)
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}
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if len(pfxs) == 0 {
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return
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}
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if t.prefixTrie == nil {
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t.prefixTrie = new(device.AllowedIPs)
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}
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for _, pfx := range pfxs {
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t.prefixTrie.Insert(pfx, p)
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}
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}
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// Build returns a RoutingTable that can be used to look up peers.
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// Build resets the RoutingTableBuilder to its zero value.
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func (t *RoutingTableBuilder) Build() *RoutingTable {
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pt := t.prefixTrie
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t.prefixTrie = nil
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t.peers = nil
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return &RoutingTable{
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prefixTrie: pt,
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}
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}
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// RoutingTable provides a mapping from IP addresses to peers identified by
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// their public node key. It is used to find the peer that should be used to
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// route a given IP address.
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// It is immutable after creation.
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//
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// It is safe for concurrent use.
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type RoutingTable struct {
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prefixTrie *device.AllowedIPs
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}
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// Lookup returns the peer that would be used to route the given IP address.
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// If no peer is found, Lookup returns the zero value.
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func (t *RoutingTable) Lookup(ip netip.Addr) (_ key.NodePublic, ok bool) {
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if t == nil {
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return key.NodePublic{}, false
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}
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p := t.prefixTrie.Lookup(ip.AsSlice())
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if p == nil {
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return key.NodePublic{}, false
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}
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return p.Key(), true
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}
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