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tailscale/types/netmap/netmap.go

285 lines
7.1 KiB
Go

// 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 netmap contains the netmap.NetworkMap type.
package netmap
import (
"encoding/json"
"fmt"
"reflect"
"strings"
"time"
"inet.af/netaddr"
"tailscale.com/tailcfg"
"tailscale.com/types/wgkey"
"tailscale.com/wgengine/filter"
)
// NetworkMap is the current state of the world.
//
// The fields should all be considered read-only. They might
// alias parts of previous NetworkMap values.
type NetworkMap struct {
// Core networking
SelfNode *tailcfg.Node
NodeKey tailcfg.NodeKey
PrivateKey wgkey.Private
Expiry time.Time
// Name is the DNS name assigned to this node.
Name string
Addresses []netaddr.IPPrefix // same as tailcfg.Node.Addresses (IP addresses of this Node directly)
LocalPort uint16 // used for debugging
MachineStatus tailcfg.MachineStatus
MachineKey tailcfg.MachineKey
Peers []*tailcfg.Node // sorted by Node.ID
DNS tailcfg.DNSConfig
Hostinfo tailcfg.Hostinfo
PacketFilter []filter.Match
// CollectServices reports whether this node's Tailnet has
// requested that info about services be included in HostInfo.
// If set, Hostinfo.ShieldsUp blocks services collection; that
// takes precedence over this field.
CollectServices bool
// DERPMap is the last DERP server map received. It's reused
// between updates and should not be modified.
DERPMap *tailcfg.DERPMap
// Debug knobs from control server for debug or feature gating.
Debug *tailcfg.Debug
// ACLs
User tailcfg.UserID
Domain string
UserProfiles map[tailcfg.UserID]tailcfg.UserProfile
}
// MagicDNSSuffix returns the domain's MagicDNS suffix (even if
// MagicDNS isn't necessarily in use).
//
// It will neither start nor end with a period.
func (nm *NetworkMap) MagicDNSSuffix() string {
name := strings.Trim(nm.Name, ".")
if i := strings.Index(name, "."); i != -1 {
name = name[i+1:]
}
return name
}
func (nm *NetworkMap) String() string {
return nm.Concise()
}
func (nm *NetworkMap) Concise() string {
buf := new(strings.Builder)
nm.printConciseHeader(buf)
for _, p := range nm.Peers {
printPeerConcise(buf, p)
}
return buf.String()
}
func (nm *NetworkMap) VeryConcise() string {
buf := new(strings.Builder)
nm.printConciseHeader(buf)
return buf.String()
}
// printConciseHeader prints a concise header line representing nm to buf.
//
// If this function is changed to access different fields of nm, keep
// in equalConciseHeader in sync.
func (nm *NetworkMap) printConciseHeader(buf *strings.Builder) {
fmt.Fprintf(buf, "netmap: self: %v auth=%v",
nm.NodeKey.ShortString(), nm.MachineStatus)
login := nm.UserProfiles[nm.User].LoginName
if login == "" {
if nm.User.IsZero() {
login = "?"
} else {
login = fmt.Sprint(nm.User)
}
}
fmt.Fprintf(buf, " u=%s", login)
if nm.LocalPort != 0 {
fmt.Fprintf(buf, " port=%v", nm.LocalPort)
}
if nm.Debug != nil {
j, _ := json.Marshal(nm.Debug)
fmt.Fprintf(buf, " debug=%s", j)
}
fmt.Fprintf(buf, " %v", nm.Addresses)
buf.WriteByte('\n')
}
// equalConciseHeader reports whether a and b are equal for the fields
// used by printConciseHeader.
func (a *NetworkMap) equalConciseHeader(b *NetworkMap) bool {
if a.NodeKey != b.NodeKey ||
a.MachineStatus != b.MachineStatus ||
a.LocalPort != b.LocalPort ||
a.User != b.User ||
len(a.Addresses) != len(b.Addresses) {
return false
}
for i, a := range a.Addresses {
if b.Addresses[i] != a {
return false
}
}
return (a.Debug == nil && b.Debug == nil) || reflect.DeepEqual(a.Debug, b.Debug)
}
// printPeerConcise appends to buf a line representing the peer p.
//
// If this function is changed to access different fields of p, keep
// in nodeConciseEqual in sync.
func printPeerConcise(buf *strings.Builder, p *tailcfg.Node) {
aip := make([]string, len(p.AllowedIPs))
for i, a := range p.AllowedIPs {
s := strings.TrimSuffix(fmt.Sprint(a), "/32")
aip[i] = s
}
ep := make([]string, len(p.Endpoints))
for i, e := range p.Endpoints {
// Align vertically on the ':' between IP and port
colon := strings.IndexByte(e, ':')
spaces := 0
for colon > 0 && len(e)+spaces-colon < 6 {
spaces++
colon--
}
ep[i] = fmt.Sprintf("%21v", e+strings.Repeat(" ", spaces))
}
derp := p.DERP
const derpPrefix = "127.3.3.40:"
if strings.HasPrefix(derp, derpPrefix) {
derp = "D" + derp[len(derpPrefix):]
}
var discoShort string
if !p.DiscoKey.IsZero() {
discoShort = p.DiscoKey.ShortString() + " "
}
// Most of the time, aip is just one element, so format the
// table to look good in that case. This will also make multi-
// subnet nodes stand out visually.
fmt.Fprintf(buf, " %v %s%-2v %-15v : %v\n",
p.Key.ShortString(),
discoShort,
derp,
strings.Join(aip, " "),
strings.Join(ep, " "))
}
// nodeConciseEqual reports whether a and b are equal for the fields accessed by printPeerConcise.
func nodeConciseEqual(a, b *tailcfg.Node) bool {
return a.Key == b.Key &&
a.DERP == b.DERP &&
a.DiscoKey == b.DiscoKey &&
eqCIDRsIgnoreNil(a.AllowedIPs, b.AllowedIPs) &&
eqStringsIgnoreNil(a.Endpoints, b.Endpoints)
}
func (b *NetworkMap) ConciseDiffFrom(a *NetworkMap) string {
var diff strings.Builder
// See if header (non-peers, "bare") part of the network map changed.
// If so, print its diff lines first.
if !a.equalConciseHeader(b) {
diff.WriteByte('-')
a.printConciseHeader(&diff)
diff.WriteByte('+')
b.printConciseHeader(&diff)
}
aps, bps := a.Peers, b.Peers
for len(aps) > 0 && len(bps) > 0 {
pa, pb := aps[0], bps[0]
switch {
case pa.ID == pb.ID:
if !nodeConciseEqual(pa, pb) {
diff.WriteByte('-')
printPeerConcise(&diff, pa)
diff.WriteByte('+')
printPeerConcise(&diff, pb)
}
aps, bps = aps[1:], bps[1:]
case pa.ID > pb.ID:
// New peer in b.
diff.WriteByte('+')
printPeerConcise(&diff, pb)
bps = bps[1:]
case pb.ID > pa.ID:
// Deleted peer in b.
diff.WriteByte('-')
printPeerConcise(&diff, pa)
aps = aps[1:]
}
}
for _, pa := range aps {
diff.WriteByte('-')
printPeerConcise(&diff, pa)
}
for _, pb := range bps {
diff.WriteByte('+')
printPeerConcise(&diff, pb)
}
return diff.String()
}
func (nm *NetworkMap) JSON() string {
b, err := json.MarshalIndent(*nm, "", " ")
if err != nil {
return fmt.Sprintf("[json error: %v]", err)
}
return string(b)
}
// WGConfigFlags is a bitmask of flags to control the behavior of the
// wireguard configuration generation done by NetMap.WGCfg.
type WGConfigFlags int
const (
AllowSingleHosts WGConfigFlags = 1 << iota
AllowSubnetRoutes
)
// 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 {
if len(a) != len(b) {
return false
}
for i, v := range a {
if v != b[i] {
return false
}
}
return true
}
// eqCIDRsIgnoreNil reports whether a and b have the same length and
// contents, but ignore whether a or b are nil.
func eqCIDRsIgnoreNil(a, b []netaddr.IPPrefix) bool {
if len(a) != len(b) {
return false
}
for i, v := range a {
if v != b[i] {
return false
}
}
return true
}