@ -8,8 +8,12 @@
package conn25
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/netip"
"slices"
@ -17,6 +21,7 @@ import (
"go4.org/netipx"
"golang.org/x/net/dns/dnsmessage"
"tailscale.com/appc"
"tailscale.com/feature"
"tailscale.com/ipn/ipnext"
"tailscale.com/ipn/ipnlocal"
@ -33,16 +38,30 @@ import (
// It is also the [extension] name and the log prefix.
const featureName = "conn25"
const maxBodyBytes = 1024 * 1024
// jsonDecode decodes all of a io.ReadCloser (eg an http.Request Body) into one pointer with best practices.
// It limits the size of bytes it will read.
// It either decodes all of the bytes into the pointer, or errors (unlike json.Decoder.Decode).
// It closes the ReadCloser after reading.
func jsonDecode ( target any , rc io . ReadCloser ) error {
defer rc . Close ( )
respBs , err := io . ReadAll ( io . LimitReader ( rc , maxBodyBytes + 1 ) )
if err != nil {
return err
}
err = json . Unmarshal ( respBs , & target )
return err
}
func init ( ) {
feature . Register ( featureName )
newExtension := func ( logf logger . Logf , sb ipnext . SafeBackend ) ( ipnext . Extension , error ) {
e := & extension {
ipnext . RegisterExtension ( featureName , func ( logf logger . Logf , sb ipnext . SafeBackend ) ( ipnext . Extension , error ) {
return & extension {
conn25 : newConn25 ( logger . WithPrefix ( logf , "conn25: " ) ) ,
backend : sb ,
}
return e , nil
}
ipnext . RegisterExtension ( featureName , newExtension )
} , nil
} )
ipnlocal . RegisterPeerAPIHandler ( "/v0/connector/transit-ip" , handleConnectorTransitIP )
}
@ -61,6 +80,9 @@ type extension struct {
conn25 * Conn25 // safe for concurrent access and only set at creation
backend ipnext . SafeBackend // safe for concurrent access and only set at creation
host ipnext . Host // set in Init, read-only after
ctxCancel context . CancelCauseFunc // cancels sendLoop goroutine
mu sync . Mutex // protects the fields below
isDNSHookRegistered bool
}
@ -72,17 +94,32 @@ func (e *extension) Name() string {
// Init implements [ipnext.Extension].
func ( e * extension ) Init ( host ipnext . Host ) error {
//Init only once
e . mu . Lock ( )
defer e . mu . Unlock ( )
if e . ctxCancel != nil {
return nil
}
e . host = host
host . Hooks ( ) . OnSelfChange . Add ( e . onSelfChange )
ctx , cancel := context . WithCancelCause ( context . Background ( ) )
e . ctxCancel = cancel
go e . sendLoop ( ctx )
return nil
}
// Shutdown implements [ipnlocal.Extension].
func ( e * extension ) Shutdown ( ) error {
if e . ctxCancel != nil {
e . ctxCancel ( errors . New ( "extension shutdown" ) )
}
if e . conn25 != nil {
close ( e . conn25 . client . addrsCh )
}
return nil
}
func ( e * extension ) handleConnectorTransitIP ( h ipnlocal . PeerAPIHandler , w http . ResponseWriter , r * http . Request ) {
const maxBodyBytes = 1024 * 1024
defer r . Body . Close ( )
if r . Method != "POST" {
http . Error ( w , "Method should be POST" , http . StatusMethodNotAllowed )
@ -172,7 +209,10 @@ func (c *Conn25) isConfigured() bool {
func newConn25 ( logf logger . Logf ) * Conn25 {
c := & Conn25 {
client : & client { logf : logf } ,
client : & client {
logf : logf ,
addrsCh : make ( chan addrs , 64 ) ,
} ,
connector : & connector { logf : logf } ,
}
return c
@ -310,7 +350,8 @@ const AppConnectorsExperimentalAttrName = "tailscale.com/app-connectors-experime
type config struct {
isConfigured bool
apps [ ] appctype . Conn25Attr
appsByDomain map [ dnsname . FQDN ] [ ] string
appsByName map [ string ] appctype . Conn25Attr
appNamesByDomain map [ dnsname . FQDN ] [ ] string
selfRoutedDomains set . Set [ dnsname . FQDN ]
}
@ -326,7 +367,8 @@ func configFromNodeView(n tailcfg.NodeView) (config, error) {
cfg := config {
isConfigured : true ,
apps : apps ,
appsByDomain : map [ dnsname . FQDN ] [ ] string { } ,
appsByName : map [ string ] appctype . Conn25Attr { } ,
appNamesByDomain : map [ dnsname . FQDN ] [ ] string { } ,
selfRoutedDomains : set . Set [ dnsname . FQDN ] { } ,
}
for _ , app := range apps {
@ -336,11 +378,12 @@ func configFromNodeView(n tailcfg.NodeView) (config, error) {
if err != nil {
return config { } , err
}
mak . Set ( & cfg . appsByDomain , fqdn , append ( cfg . appsByDomain [ fqdn ] , app . Name ) )
mak . Set ( & cfg . appName sByDomain , fqdn , append ( cfg . appName sByDomain [ fqdn ] , app . Name ) )
if selfMatchesTags {
cfg . selfRoutedDomains . Add ( fqdn )
}
}
mak . Set ( & cfg . appsByName , app . Name , app )
}
return cfg , nil
}
@ -350,7 +393,8 @@ func configFromNodeView(n tailcfg.NodeView) (config, error) {
// connectors.
// It's safe for concurrent use.
type client struct {
logf logger . Logf
logf logger . Logf
addrsCh chan addrs
mu sync . Mutex // protects the fields below
magicIPPool * ippool
@ -402,7 +446,7 @@ func (c *client) reconfig(newCfg config) error {
func ( c * client ) isConnectorDomain ( domain dnsname . FQDN ) bool {
c . mu . Lock ( )
defer c . mu . Unlock ( )
appNames , ok := c . config . appsByDomain [ domain ]
appNames , ok := c . config . appName sByDomain [ domain ]
return ok && len ( appNames ) > 0
}
@ -416,7 +460,7 @@ func (c *client) reserveAddresses(domain dnsname.FQDN, dst netip.Addr) (addrs, e
if existing , ok := c . assignments . lookupByDomainDst ( domain , dst ) ; ok {
return existing , nil
}
appNames , _ := c . config . appsByDomain [ domain ]
appNames , _ := c . config . appName sByDomain [ domain ]
// only reserve for first app
app := appNames [ 0 ]
mip , err := c . magicIPPool . next ( )
@ -437,12 +481,100 @@ func (c *client) reserveAddresses(domain dnsname.FQDN, dst netip.Addr) (addrs, e
if err := c . assignments . insert ( as ) ; err != nil {
return addrs { } , err
}
err = c . enqueueAddressAssignment ( as )
if err != nil {
return addrs { } , err
}
return as , nil
}
func ( c * client ) enqueueAddressAssignment ( addrs addrs ) {
// TODO(fran) 2026-02-03 asynchronously send peerapi req to connector to
// allocate these addresses for us.
func ( e * extension ) sendLoop ( ctx context . Context ) {
for {
select {
case <- ctx . Done ( ) :
return
case as := <- e . conn25 . client . addrsCh :
if err := e . sendAddressAssignment ( ctx , as ) ; err != nil {
e . conn25 . client . logf ( "error sending transit IP assignment (app: %s, mip: %v, src: %v): %v" , as . app , as . magic , as . dst , err )
}
}
}
}
func ( c * client ) enqueueAddressAssignment ( addrs addrs ) error {
select {
// TODO(fran) investigate the value of waiting for multiple addresses and sending them
// in one ConnectorTransitIPRequest
case c . addrsCh <- addrs :
return nil
default :
c . logf ( "address assignment queue full, dropping transit assignment for %v" , addrs . domain )
return errors . New ( "queue full" )
}
}
func makePeerAPIReq ( ctx context . Context , httpClient * http . Client , urlBase string , as addrs ) error {
url := urlBase + "/v0/connector/transit-ip"
reqBody := ConnectorTransitIPRequest {
TransitIPs : [ ] TransitIPRequest { {
TransitIP : as . transit ,
DestinationIP : as . dst ,
App : as . app ,
} } ,
}
bs , err := json . Marshal ( reqBody )
if err != nil {
return fmt . Errorf ( "marshalling request: %w" , err )
}
req , err := http . NewRequestWithContext ( ctx , "POST" , url , bytes . NewReader ( bs ) )
if err != nil {
return fmt . Errorf ( "creating request: %w" , err )
}
resp , err := httpClient . Do ( req )
if err != nil {
return fmt . Errorf ( "sending request: %w" , err )
}
defer resp . Body . Close ( )
if resp . StatusCode != http . StatusOK {
return fmt . Errorf ( "connector returned HTTP %d" , resp . StatusCode )
}
var respBody ConnectorTransitIPResponse
err = jsonDecode ( & respBody , resp . Body )
if err != nil {
return fmt . Errorf ( "decoding response: %w" , err )
}
if len ( respBody . TransitIPs ) > 0 && respBody . TransitIPs [ 0 ] . Code != OK {
return fmt . Errorf ( "connector error: %s" , respBody . TransitIPs [ 0 ] . Message )
}
return nil
}
func ( e * extension ) sendAddressAssignment ( ctx context . Context , as addrs ) error {
app , ok := e . conn25 . client . config . appsByName [ as . app ]
if ! ok {
e . conn25 . client . logf ( "App not found for app: %s (domain: %s)" , as . app , as . domain )
return errors . New ( "app not found" )
}
nb := e . host . NodeBackend ( )
peers := appc . PickConnector ( nb , app )
var urlBase string
for _ , p := range peers {
urlBase = nb . PeerAPIBase ( p )
if urlBase != "" {
break
}
}
if urlBase == "" {
return errors . New ( "no connector peer found to handle address assignment" )
}
client := e . backend . Sys ( ) . Dialer . Get ( ) . PeerAPIHTTPClient ( )
return makePeerAPIReq ( ctx , client , urlBase , as )
}
func ( c * client ) mapDNSResponse ( buf [ ] byte ) [ ] byte {
@ -501,7 +633,6 @@ func (c *client) mapDNSResponse(buf []byte) []byte {
c . logf ( "assigned connector addresses unexpectedly empty: %v" , err )
return buf
}
c . enqueueAddressAssignment ( addrs )
default :
if err := p . SkipAnswer ( ) ; err != nil {
c . logf ( "error parsing dns response: %v" , err )
Fran Bull
2 months ago
committed by