Fran Bull
93 lines
2.5 KiB
Go
93 lines
2.5 KiB
Go
// Copyright (c) Tailscale Inc & contributors
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// SPDX-License-Identifier: BSD-3-Clause
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package conn25
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import (
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"errors"
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"net/netip"
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"time"
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"tailscale.com/tstime"
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"tailscale.com/util/dnsname"
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"tailscale.com/util/mak"
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)
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// domainDst is a key for looking up an existing address assignment by the
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// DNS response domain and destination IP pair.
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type domainDst struct {
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domain dnsname.FQDN
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dst netip.Addr
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}
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// addrAssignments is the collection of addrs assigned by this client
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// supporting lookup by magic IP, transit IP or domain+dst, or to lookup all
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// transit IPs associated with a given connector (identified by its node key).
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// byConnKey stores netip.Prefix versions of the transit IPs for use in the
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// WireGuard hooks.
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type addrAssignments struct {
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byMagicIP map[netip.Addr]addrs
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byTransitIP map[netip.Addr]addrs
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byDomainDst map[domainDst]addrs
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clock tstime.Clock
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}
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const defaultExpiry = 48 * time.Hour
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func (a *addrAssignments) insert(as addrs) error {
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return a.insertWithExpiry(as, defaultExpiry)
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}
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func (a *addrAssignments) insertWithExpiry(as addrs, d time.Duration) error {
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if !as.expiresAt.IsZero() {
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return errors.New("expiresAt already set")
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}
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now := a.clock.Now()
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as.expiresAt = now.Add(d)
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// we don't expect for addresses to be reused before expiry
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if existing, ok := a.byMagicIP[as.magic]; ok {
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if !existing.expiresAt.Before(now) {
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return errors.New("byMagicIP key exists")
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}
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}
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ddst := domainDst{domain: as.domain, dst: as.dst}
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if existing, ok := a.byDomainDst[ddst]; ok {
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if !existing.expiresAt.Before(now) {
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return errors.New("byDomainDst key exists")
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}
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}
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if existing, ok := a.byTransitIP[as.transit]; ok {
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if !existing.expiresAt.Before(now) {
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return errors.New("byTransitIP key exists")
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}
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}
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mak.Set(&a.byMagicIP, as.magic, as)
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mak.Set(&a.byTransitIP, as.transit, as)
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mak.Set(&a.byDomainDst, ddst, as)
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return nil
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}
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func (a *addrAssignments) lookupByDomainDst(domain dnsname.FQDN, dst netip.Addr) (addrs, bool) {
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v, ok := a.byDomainDst[domainDst{domain: domain, dst: dst}]
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if !ok || v.expiresAt.Before(a.clock.Now()) {
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return addrs{}, false
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}
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return v, true
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}
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func (a *addrAssignments) lookupByMagicIP(mip netip.Addr) (addrs, bool) {
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v, ok := a.byMagicIP[mip]
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if !ok || v.expiresAt.Before(a.clock.Now()) {
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return addrs{}, false
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}
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return v, true
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}
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func (a *addrAssignments) lookupByTransitIP(tip netip.Addr) (addrs, bool) {
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v, ok := a.byTransitIP[tip]
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if !ok || v.expiresAt.Before(a.clock.Now()) {
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return addrs{}, false
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}
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return v, true
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}
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