tailcfg: add DNS routes and advanced resolver config.

Signed-off-by: David Anderson <danderson@tailscale.com>
pull/1673/head
David Anderson 4 years ago committed by Dave Anderson
parent 6a7912e37a
commit fad21af01c

@ -1486,16 +1486,30 @@ func (b *LocalBackend) authReconfig() {
// If CorpDNS is false, dcfg remains the zero value.
if uc.CorpDNS {
proxied := nm.DNS.Proxied
if proxied && len(nm.DNS.Nameservers) == 0 {
b.logf("[unexpected] dns proxied but no nameservers")
proxied = false
for _, resolver := range nm.DNS.Resolvers {
res, err := parseResolver(resolver)
if err != nil {
b.logf(err.Error())
continue
}
dcfg.DefaultResolvers = append(dcfg.DefaultResolvers, res)
}
for _, ip := range nm.DNS.Nameservers {
dcfg.DefaultResolvers = append(dcfg.DefaultResolvers, netaddr.IPPort{
IP: ip,
Port: 53,
})
if len(nm.DNS.Routes) > 0 {
dcfg.Routes = map[string][]netaddr.IPPort{}
}
for suffix, resolvers := range nm.DNS.Routes {
if !strings.HasSuffix(suffix, ".") || strings.HasPrefix(suffix, ".") {
b.logf("[unexpected] malformed DNS route suffix %q", suffix)
continue
}
for _, resolver := range resolvers {
res, err := parseResolver(resolver)
if err != nil {
b.logf(err.Error())
continue
}
dcfg.Routes[suffix] = append(dcfg.Routes[suffix], res)
}
}
dcfg.SearchDomains = nm.DNS.Domains
dcfg.AuthoritativeSuffixes = magicDNSRootDomains(nm)
@ -1509,9 +1523,12 @@ func (b *LocalBackend) authReconfig() {
}
dcfg.Hosts[name] = ips
}
// TODO: hack to make the current code continue to work while
// refactoring happens.
if proxied {
enableMagicDNS := nm.DNS.Proxied
if enableMagicDNS && len(nm.DNS.Resolvers) == 0 {
b.logf("[unexpected] dns proxied but no nameservers")
enableMagicDNS = false
}
if enableMagicDNS {
dcfg.Hosts = map[string][]netaddr.IP{}
set(nm.Name, nm.Addresses)
for _, peer := range nm.Peers {
@ -1529,6 +1546,17 @@ func (b *LocalBackend) authReconfig() {
b.initPeerAPIListener()
}
func parseResolver(cfg tailcfg.DNSResolver) (netaddr.IPPort, error) {
ip, err := netaddr.ParseIP(cfg.Addr)
if err != nil {
return netaddr.IPPort{}, fmt.Errorf("[unexpected] non-IP resolver %q", cfg.Addr)
}
return netaddr.IPPort{
IP: ip,
Port: 53,
}, nil
}
// tailscaleVarRoot returns the root directory of Tailscale's writable
// storage area. (e.g. "/var/lib/tailscale")
func tailscaleVarRoot() string {

@ -4,7 +4,7 @@
package tailcfg
//go:generate go run tailscale.com/cmd/cloner --type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse --clonefunc=true --output=tailcfg_clone.go
//go:generate go run tailscale.com/cmd/cloner --type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse --clonefunc=true --output=tailcfg_clone.go
import (
"bytes"
@ -36,7 +36,8 @@ import (
// 11: 2021-03-03: client understands IPv6, multiple default routes, and goroutine dumping
// 12: 2021-03-04: client understands PingRequest
// 13: 2021-03-19: client understands FilterRule.IPProto
const CurrentMapRequestVersion = 13
// 14: 2021-04-07: client understands DNSConfig.Routes and DNSConfig.Resolvers
const CurrentMapRequestVersion = 14
type StableID string
@ -763,19 +764,52 @@ var FilterAllowAll = []FilterRule{
},
}
// DNSResolver is the configuration for one DNS resolver.
type DNSResolver struct {
// Addr is the address of the DNS resolver, one of:
// - A plain IP address for a "classic" UDP+TCP DNS resolver
// - [TODO] "tls://resolver.com" for DNS over TCP+TLS
// - [TODO] "https://resolver.com/query-tmpl" for DNS over HTTPS
Addr string `json:",omitempty"`
// BootstrapResolution is an optional suggested resolution for the
// DoT/DoH resolver, if the resolver URL does not reference an IP
// address directly.
// BootstrapResolution may be empty, in which case clients should
// look up the DoT/DoH server using their local "classic" DNS
// resolver.
BootstrapResolution []netaddr.IP `json:",omitempty"`
}
// DNSConfig is the DNS configuration.
type DNSConfig struct {
// Nameservers are the IP addresses of the nameservers to use.
Nameservers []netaddr.IP `json:",omitempty"`
// Resolvers are the DNS resolvers to use, in order of preference.
Resolvers []DNSResolver `json:",omitempty"`
// Routes maps DNS name suffixes to a set of DNS resolvers to
// use. It is used to implement "split DNS" and other advanced DNS
// routing overlays.
// Map keys must be fully-qualified DNS name suffixes, with a
// trailing dot but no leading dot.
Routes map[string][]DNSResolver `json:",omitempty"`
// Domains are the search domains to use.
// Search domains must be FQDNs, but *without* the trailing dot.
Domains []string `json:",omitempty"`
// Proxied turns on automatic resolution of hostnames for devices
// in the network map, aka MagicDNS.
// Despite the (legacy) name, does not necessarily cause request
// proxying to be enabled.
Proxied bool `json:",omitempty"`
// The following fields are only set and used by
// MapRequest.Version >=9 and <14.
// Nameservers are the IP addresses of the nameservers to use.
Nameservers []netaddr.IP `json:",omitempty"`
// PerDomain is not set by the control server, and does nothing.
// TODO(danderson): revise DNS configuration to make this useful
// again.
PerDomain bool
// Proxied indicates whether DNS requests are proxied through a dns.Resolver.
// This enables MagicDNS.
Proxied bool
PerDomain bool `json:",omitempty"`
}
// PingRequest is a request to send an HTTP request to prove the
@ -829,15 +863,11 @@ type MapResponse struct {
PeerSeenChange map[NodeID]bool `json:",omitempty"`
// DNS is the same as DNSConfig.Nameservers.
//
// TODO(dmytro): should be sent in DNSConfig.Nameservers once clients have updated.
// Only populated if MapRequest.Version < 9.
DNS []netaddr.IP `json:",omitempty"`
// SearchPaths is the old way to specify DNS search
// domains. Clients should use these values if set, but the
// server will omit this field for clients with
// MapRequest.Version >= 9. Clients should prefer to use
// DNSConfig.Domains instead.
// SearchPaths is the old way to specify DNS search domains.
// Only populated if MapRequest.Version < 9.
SearchPaths []string `json:",omitempty"`
// DNSConfig contains the DNS settings for the client to use.

@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse; DO NOT EDIT.
// Code generated by tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse; DO NOT EDIT.
package tailcfg
@ -26,7 +26,7 @@ func (src *User) Clone() *User {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _UserNeedsRegeneration = User(struct {
ID UserID
LoginName string
@ -58,7 +58,7 @@ func (src *Node) Clone() *Node {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _NodeNeedsRegeneration = Node(struct {
ID NodeID
StableID StableNodeID
@ -100,7 +100,7 @@ func (src *Hostinfo) Clone() *Hostinfo {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _HostinfoNeedsRegeneration = Hostinfo(struct {
IPNVersion string
FrontendLogID string
@ -137,7 +137,7 @@ func (src *NetInfo) Clone() *NetInfo {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _NetInfoNeedsRegeneration = NetInfo(struct {
MappingVariesByDestIP opt.Bool
HairPinning opt.Bool
@ -164,7 +164,7 @@ func (src *Login) Clone() *Login {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _LoginNeedsRegeneration = Login(struct {
_ structs.Incomparable
ID LoginID
@ -183,18 +183,49 @@ func (src *DNSConfig) Clone() *DNSConfig {
}
dst := new(DNSConfig)
*dst = *src
dst.Nameservers = append(src.Nameservers[:0:0], src.Nameservers...)
dst.Resolvers = make([]DNSResolver, len(src.Resolvers))
for i := range dst.Resolvers {
dst.Resolvers[i] = *src.Resolvers[i].Clone()
}
if dst.Routes != nil {
dst.Routes = map[string][]DNSResolver{}
for k := range src.Routes {
dst.Routes[k] = append([]DNSResolver{}, src.Routes[k]...)
}
}
dst.Domains = append(src.Domains[:0:0], src.Domains...)
dst.Nameservers = append(src.Nameservers[:0:0], src.Nameservers...)
return dst
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _DNSConfigNeedsRegeneration = DNSConfig(struct {
Nameservers []netaddr.IP
Resolvers []DNSResolver
Routes map[string][]DNSResolver
Domains []string
PerDomain bool
Proxied bool
Nameservers []netaddr.IP
PerDomain bool
}{})
// Clone makes a deep copy of DNSResolver.
// The result aliases no memory with the original.
func (src *DNSResolver) Clone() *DNSResolver {
if src == nil {
return nil
}
dst := new(DNSResolver)
*dst = *src
dst.BootstrapResolution = append(src.BootstrapResolution[:0:0], src.BootstrapResolution...)
return dst
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _DNSResolverNeedsRegeneration = DNSResolver(struct {
Addr string
BootstrapResolution []netaddr.IP
}{})
// Clone makes a deep copy of RegisterResponse.
@ -210,7 +241,7 @@ func (src *RegisterResponse) Clone() *RegisterResponse {
}
// A compilation failure here means this code must be regenerated, with command:
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse
// tailscale.com/cmd/cloner -type User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse
var _RegisterResponseNeedsRegeneration = RegisterResponse(struct {
User User
Login Login
@ -221,7 +252,7 @@ var _RegisterResponseNeedsRegeneration = RegisterResponse(struct {
// Clone duplicates src into dst and reports whether it succeeded.
// To succeed, <src, dst> must be of types <*T, *T> or <*T, **T>,
// where T is one of User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse.
// where T is one of User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse.
func Clone(dst, src interface{}) bool {
switch src := src.(type) {
case *User:
@ -278,6 +309,15 @@ func Clone(dst, src interface{}) bool {
*dst = src.Clone()
return true
}
case *DNSResolver:
switch dst := dst.(type) {
case *DNSResolver:
*dst = *src.Clone()
return true
case **DNSResolver:
*dst = src.Clone()
return true
}
case *RegisterResponse:
switch dst := dst.(type) {
case *RegisterResponse:

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