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tailscale/ipn/serve.go

644 lines
19 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package ipn
import (
"errors"
"fmt"
"net"
"net/netip"
"net/url"
"slices"
"strconv"
"strings"
"tailscale.com/ipn/ipnstate"
"tailscale.com/tailcfg"
"tailscale.com/util/mak"
)
// ServeConfigKey returns a StateKey that stores the
// JSON-encoded ServeConfig for a config profile.
func ServeConfigKey(profileID ProfileID) StateKey {
return StateKey("_serve/" + profileID)
}
// ServeConfig is the JSON type stored in the StateStore for
// StateKey "_serve/$PROFILE_ID" as returned by ServeConfigKey.
type ServeConfig struct {
// TCP are the list of TCP port numbers that tailscaled should handle for
// the Tailscale IP addresses. (not subnet routers, etc)
TCP map[uint16]*TCPPortHandler `json:",omitempty"`
// Web maps from "$SNI_NAME:$PORT" to a set of HTTP handlers
// keyed by mount point ("/", "/foo", etc)
Web map[HostPort]*WebServerConfig `json:",omitempty"`
// AllowFunnel is the set of SNI:port values for which funnel
// traffic is allowed, from trusted ingress peers.
AllowFunnel map[HostPort]bool `json:",omitempty"`
// Foreground is a map of an IPN Bus session ID to an alternate foreground
// serve config that's valid for the life of that WatchIPNBus session ID.
// This. This allows the config to specify ephemeral configs that are
// used in the CLI's foreground mode to ensure ungraceful shutdowns
// of either the client or the LocalBackend does not expose ports
// that users are not aware of.
Foreground map[string]*ServeConfig `json:",omitempty"`
// ETag is the checksum of the serve config that's populated
// by the LocalClient through the HTTP ETag header during a
// GetServeConfig request and is translated to an If-Match header
// during a SetServeConfig request.
ETag string `json:"-"`
}
// HostPort is an SNI name and port number, joined by a colon.
// There is no implicit port 443. It must contain a colon.
type HostPort string
// Port extracts just the port number from hp.
// An error is reported in the case that the hp does not
// have a valid numeric port ending.
func (hp HostPort) Port() (uint16, error) {
_, port, err := net.SplitHostPort(string(hp))
if err != nil {
return 0, err
}
port16, err := strconv.ParseUint(port, 10, 16)
if err != nil {
return 0, err
}
return uint16(port16), nil
}
// A FunnelConn wraps a net.Conn that is coming over a
// Funnel connection. It can be used to determine further
// information about the connection, like the source address
// and the target SNI name.
type FunnelConn struct {
// Conn is the underlying connection.
net.Conn
// Target is what was presented in the "Tailscale-Ingress-Target"
// HTTP header.
Target HostPort
// Src is the source address of the connection.
// This is the address of the client that initiated the
// connection, not the address of the Tailscale Funnel
// node which is relaying the connection. That address
// can be found in Conn.RemoteAddr.
Src netip.AddrPort
}
// WebServerConfig describes a web server's configuration.
type WebServerConfig struct {
Handlers map[string]*HTTPHandler // mountPoint => handler
}
// TCPPortHandler describes what to do when handling a TCP
// connection.
type TCPPortHandler struct {
// HTTPS, if true, means that tailscaled should handle this connection as an
// HTTPS request as configured by ServeConfig.Web.
//
// It is mutually exclusive with TCPForward.
HTTPS bool `json:",omitempty"`
// HTTP, if true, means that tailscaled should handle this connection as an
// HTTP request as configured by ServeConfig.Web.
//
// It is mutually exclusive with TCPForward.
HTTP bool `json:",omitempty"`
// TCPForward is the IP:port to forward TCP connections to.
// Whether or not TLS is terminated by tailscaled depends on
// TerminateTLS.
//
// It is mutually exclusive with HTTPS.
TCPForward string `json:",omitempty"`
// TerminateTLS, if non-empty, means that tailscaled should terminate the
// TLS connections before forwarding them to TCPForward, permitting only the
// SNI name with this value. It is only used if TCPForward is non-empty.
// (the HTTPS mode uses ServeConfig.Web)
TerminateTLS string `json:",omitempty"`
}
// HTTPHandler is either a path or a proxy to serve.
type HTTPHandler struct {
// Exactly one of the following may be set.
Path string `json:",omitempty"` // absolute path to directory or file to serve
Proxy string `json:",omitempty"` // http://localhost:3000/, localhost:3030, 3030
Text string `json:",omitempty"` // plaintext to serve (primarily for testing)
// TODO(bradfitz): bool to not enumerate directories? TTL on mapping for
// temporary ones? Error codes? Redirects?
}
// WebHandlerExists reports whether if the ServeConfig Web handler exists for
// the given host:port and mount point.
func (sc *ServeConfig) WebHandlerExists(hp HostPort, mount string) bool {
h := sc.GetWebHandler(hp, mount)
return h != nil
}
// GetWebHandler returns the HTTPHandler for the given host:port and mount point.
// Returns nil if the handler does not exist.
func (sc *ServeConfig) GetWebHandler(hp HostPort, mount string) *HTTPHandler {
if sc == nil || sc.Web[hp] == nil {
return nil
}
return sc.Web[hp].Handlers[mount]
}
// GetTCPPortHandler returns the TCPPortHandler for the given port.
// If the port is not configured, nil is returned.
func (sc *ServeConfig) GetTCPPortHandler(port uint16) *TCPPortHandler {
if sc == nil {
return nil
}
return sc.TCP[port]
}
// HasPathHandler reports whether if ServeConfig has at least
// one path handler, including foreground configs.
func (sc *ServeConfig) HasPathHandler() bool {
if sc.Web != nil {
for _, webServerConfig := range sc.Web {
for _, httpHandler := range webServerConfig.Handlers {
if httpHandler.Path != "" {
return true
}
}
}
}
if sc.Foreground != nil {
for _, fgConfig := range sc.Foreground {
if fgConfig.HasPathHandler() {
return true
}
}
}
return false
}
// IsTCPForwardingAny reports whether ServeConfig is currently forwarding in
// TCPForward mode on any port. This is exclusive of Web/HTTPS serving.
func (sc *ServeConfig) IsTCPForwardingAny() bool {
if sc == nil || len(sc.TCP) == 0 {
return false
}
for _, h := range sc.TCP {
if h.TCPForward != "" {
return true
}
}
return false
}
// IsTCPForwardingOnPort reports whether if ServeConfig is currently forwarding
// in TCPForward mode on the given port. This is exclusive of Web/HTTPS serving.
func (sc *ServeConfig) IsTCPForwardingOnPort(port uint16) bool {
if sc == nil || sc.TCP[port] == nil {
return false
}
return !sc.IsServingWeb(port)
}
// IsServingWeb reports whether if ServeConfig is currently serving Web
// (HTTP/HTTPS) on the given port. This is exclusive of TCPForwarding.
func (sc *ServeConfig) IsServingWeb(port uint16) bool {
return sc.IsServingHTTP(port) || sc.IsServingHTTPS(port)
}
// IsServingHTTPS reports whether if ServeConfig is currently serving HTTPS on
// the given port. This is exclusive of HTTP and TCPForwarding.
func (sc *ServeConfig) IsServingHTTPS(port uint16) bool {
if sc == nil || sc.TCP[port] == nil {
return false
}
return sc.TCP[port].HTTPS
}
// IsServingHTTP reports whether if ServeConfig is currently serving HTTP on the
// given port. This is exclusive of HTTPS and TCPForwarding.
func (sc *ServeConfig) IsServingHTTP(port uint16) bool {
if sc == nil || sc.TCP[port] == nil {
return false
}
return sc.TCP[port].HTTP
}
// FindConfig finds a config that contains the given port, which can be
// the top level background config or an inner foreground one.
// The second result is true if it's foreground.
func (sc *ServeConfig) FindConfig(port uint16) (*ServeConfig, bool) {
if sc == nil {
return nil, false
}
if _, ok := sc.TCP[port]; ok {
return sc, false
}
for _, sc := range sc.Foreground {
if _, ok := sc.TCP[port]; ok {
return sc, true
}
}
return nil, false
}
// SetWebHandler sets the given HTTPHandler at the specified host, port,
// and mount in the serve config. sc.TCP is also updated to reflect web
// serving usage of the given port.
func (sc *ServeConfig) SetWebHandler(handler *HTTPHandler, host string, port uint16, mount string, useTLS bool) {
if sc == nil {
sc = new(ServeConfig)
}
mak.Set(&sc.TCP, port, &TCPPortHandler{HTTPS: useTLS, HTTP: !useTLS})
hp := HostPort(net.JoinHostPort(host, strconv.Itoa(int(port))))
if _, ok := sc.Web[hp]; !ok {
mak.Set(&sc.Web, hp, new(WebServerConfig))
}
mak.Set(&sc.Web[hp].Handlers, mount, handler)
// TODO(tylersmalley): handle multiple web handlers from foreground mode
for k, v := range sc.Web[hp].Handlers {
if v == handler {
continue
}
// If the new mount point ends in / and another mount point
// shares the same prefix, remove the other handler.
// (e.g. /foo/ overwrites /foo)
// The opposite example is also handled.
m1 := strings.TrimSuffix(mount, "/")
m2 := strings.TrimSuffix(k, "/")
if m1 == m2 {
delete(sc.Web[hp].Handlers, k)
}
}
}
// SetTCPForwarding sets the fwdAddr (IP:port form) to which to forward
// connections from the given port. If terminateTLS is true, TLS connections
// are terminated with only the given host name permitted before passing them
// to the fwdAddr.
func (sc *ServeConfig) SetTCPForwarding(port uint16, fwdAddr string, terminateTLS bool, host string) {
if sc == nil {
sc = new(ServeConfig)
}
mak.Set(&sc.TCP, port, &TCPPortHandler{TCPForward: fwdAddr})
if terminateTLS {
sc.TCP[port].TerminateTLS = host
}
}
// SetFunnel sets the sc.AllowFunnel value for the given host and port.
func (sc *ServeConfig) SetFunnel(host string, port uint16, setOn bool) {
if sc == nil {
sc = new(ServeConfig)
}
hp := HostPort(net.JoinHostPort(host, strconv.Itoa(int(port))))
// TODO(tylersmalley): should ensure there is no other conflicting funnel
// TODO(tylersmalley): add error handling for if toggling for existing sc
if setOn {
mak.Set(&sc.AllowFunnel, hp, true)
} else if _, exists := sc.AllowFunnel[hp]; exists {
delete(sc.AllowFunnel, hp)
// Clear map mostly for testing.
if len(sc.AllowFunnel) == 0 {
sc.AllowFunnel = nil
}
}
}
// RemoveWebHandler deletes the web handlers at all of the given mount points
// for the provided host and port in the serve config. If cleanupFunnel is
// true, this also removes the funnel value for this port if no handlers remain.
func (sc *ServeConfig) RemoveWebHandler(host string, port uint16, mounts []string, cleanupFunnel bool) {
hp := HostPort(net.JoinHostPort(host, strconv.Itoa(int(port))))
// Delete existing handler, then cascade delete if empty.
for _, m := range mounts {
delete(sc.Web[hp].Handlers, m)
}
if len(sc.Web[hp].Handlers) == 0 {
delete(sc.Web, hp)
delete(sc.TCP, port)
if cleanupFunnel {
delete(sc.AllowFunnel, hp) // disable funnel if no mounts remain for the port
}
}
// Clear empty maps, mostly for testing.
if len(sc.Web) == 0 {
sc.Web = nil
}
if len(sc.TCP) == 0 {
sc.TCP = nil
}
if len(sc.AllowFunnel) == 0 {
sc.AllowFunnel = nil
}
}
// RemoveTCPForwarding deletes the TCP forwarding configuration for the given
// port from the serve config.
func (sc *ServeConfig) RemoveTCPForwarding(port uint16) {
delete(sc.TCP, port)
if len(sc.TCP) == 0 {
sc.TCP = nil
}
}
// IsFunnelOn reports whether if ServeConfig is currently allowing funnel
// traffic for any host:port.
//
// View version of ServeConfig.IsFunnelOn.
func (v ServeConfigView) IsFunnelOn() bool { return v.ж.IsFunnelOn() }
// IsFunnelOn reports whether if ServeConfig is currently allowing funnel
// traffic for any host:port.
func (sc *ServeConfig) IsFunnelOn() bool {
if sc == nil {
return false
}
for _, b := range sc.AllowFunnel {
if b {
return true
}
}
return false
}
// CheckFunnelAccess checks whether Funnel access is allowed for the given node
// and port.
// It checks:
// 1. HTTPS is enabled on the tailnet
// 2. the node has the "funnel" nodeAttr
// 3. the port is allowed for Funnel
//
// The node arg should be the ipnstate.Status.Self node.
func CheckFunnelAccess(port uint16, node *ipnstate.PeerStatus) error {
if err := NodeCanFunnel(node); err != nil {
return err
}
return CheckFunnelPort(port, node)
}
// NodeCanFunnel returns an error if the given node is not configured to allow
// for Tailscale Funnel usage.
func NodeCanFunnel(node *ipnstate.PeerStatus) error {
if !node.HasCap(tailcfg.CapabilityHTTPS) {
return errors.New("Funnel not available; HTTPS must be enabled. See https://tailscale.com/s/https.")
}
if !node.HasCap(tailcfg.NodeAttrFunnel) {
return errors.New("Funnel not available; \"funnel\" node attribute not set. See https://tailscale.com/s/no-funnel.")
}
return nil
}
// CheckFunnelPort checks whether the given port is allowed for Funnel.
// It uses the tailcfg.CapabilityFunnelPorts nodeAttr to determine the allowed
// ports.
func CheckFunnelPort(wantedPort uint16, node *ipnstate.PeerStatus) error {
deny := func(allowedPorts string) error {
if allowedPorts == "" {
return fmt.Errorf("port %d is not allowed for funnel", wantedPort)
}
return fmt.Errorf("port %d is not allowed for funnel; allowed ports are: %v", wantedPort, allowedPorts)
}
var portsStr string
parseAttr := func(attr string) (string, error) {
u, err := url.Parse(attr)
if err != nil {
return "", deny("")
}
portsStr := u.Query().Get("ports")
if portsStr == "" {
return "", deny("")
}
u.RawQuery = ""
if u.String() != string(tailcfg.CapabilityFunnelPorts) {
return "", deny("")
}
return portsStr, nil
}
for attr := range node.CapMap {
attr := string(attr)
if !strings.HasPrefix(attr, string(tailcfg.CapabilityFunnelPorts)) {
continue
}
var err error
portsStr, err = parseAttr(attr)
if err != nil {
return err
}
break
}
if portsStr == "" {
for _, attr := range node.Capabilities {
attr := string(attr)
if !strings.HasPrefix(attr, string(tailcfg.CapabilityFunnelPorts)) {
continue
}
var err error
portsStr, err = parseAttr(attr)
if err != nil {
return err
}
break
}
}
if portsStr == "" {
return deny("")
}
wantedPortString := strconv.Itoa(int(wantedPort))
for _, ps := range strings.Split(portsStr, ",") {
if ps == "" {
continue
}
first, last, ok := strings.Cut(ps, "-")
if !ok {
if first == wantedPortString {
return nil
}
continue
}
fp, err := strconv.ParseUint(first, 10, 16)
if err != nil {
continue
}
lp, err := strconv.ParseUint(last, 10, 16)
if err != nil {
continue
}
pr := tailcfg.PortRange{First: uint16(fp), Last: uint16(lp)}
if pr.Contains(wantedPort) {
return nil
}
}
return deny(portsStr)
}
// ExpandProxyTargetValue expands the supported target values to be proxied
// allowing for input values to be a port number, a partial URL, or a full URL
// including a path.
//
// examples:
// - 3000
// - localhost:3000
// - tcp://localhost:3000
// - http://localhost:3000
// - https://localhost:3000
// - https-insecure://localhost:3000
// - https-insecure://localhost:3000/foo
func ExpandProxyTargetValue(target string, supportedSchemes []string, defaultScheme string) (string, error) {
const host = "127.0.0.1"
// support target being a port number
if port, err := strconv.ParseUint(target, 10, 16); err == nil {
return fmt.Sprintf("%s://%s:%d", defaultScheme, host, port), nil
}
// prepend scheme if not present
if !strings.Contains(target, "://") {
target = defaultScheme + "://" + target
}
// make sure we can parse the target
u, err := url.ParseRequestURI(target)
if err != nil {
return "", fmt.Errorf("invalid URL %w", err)
}
// ensure a supported scheme
if !slices.Contains(supportedSchemes, u.Scheme) {
return "", fmt.Errorf("must be a URL starting with one of the supported schemes: %v", supportedSchemes)
}
// validate the host.
switch u.Hostname() {
case "localhost", "127.0.0.1":
default:
return "", errors.New("only localhost or 127.0.0.1 proxies are currently supported")
}
// validate the port
port, err := strconv.ParseUint(u.Port(), 10, 16)
if err != nil || port == 0 {
return "", fmt.Errorf("invalid port %q", u.Port())
}
u.Host = fmt.Sprintf("%s:%d", host, port)
return u.String(), nil
}
// RangeOverTCPs ranges over both background and foreground TCPs.
// If the returned bool from the given f is false, then this function stops
// iterating immediately and does not check other foreground configs.
func (v ServeConfigView) RangeOverTCPs(f func(port uint16, _ TCPPortHandlerView) bool) {
parentCont := true
v.TCP().Range(func(k uint16, v TCPPortHandlerView) (cont bool) {
parentCont = f(k, v)
return parentCont
})
v.Foreground().Range(func(k string, v ServeConfigView) (cont bool) {
if !parentCont {
return false
}
v.TCP().Range(func(k uint16, v TCPPortHandlerView) (cont bool) {
parentCont = f(k, v)
return parentCont
})
return parentCont
})
}
// RangeOverWebs ranges over both background and foreground Webs.
// If the returned bool from the given f is false, then this function stops
// iterating immediately and does not check other foreground configs.
func (v ServeConfigView) RangeOverWebs(f func(_ HostPort, conf WebServerConfigView) bool) {
parentCont := true
v.Web().Range(func(k HostPort, v WebServerConfigView) (cont bool) {
parentCont = f(k, v)
return parentCont
})
v.Foreground().Range(func(k string, v ServeConfigView) (cont bool) {
if !parentCont {
return false
}
v.Web().Range(func(k HostPort, v WebServerConfigView) (cont bool) {
parentCont = f(k, v)
return parentCont
})
return parentCont
})
}
// FindTCP returns the first TCP that matches with the given port. It
// prefers a foreground match first followed by a background search if none
// existed.
func (v ServeConfigView) FindTCP(port uint16) (res TCPPortHandlerView, ok bool) {
v.Foreground().Range(func(_ string, v ServeConfigView) (cont bool) {
res, ok = v.TCP().GetOk(port)
return !ok
})
if ok {
return res, ok
}
return v.TCP().GetOk(port)
}
// FindWeb returns the first Web that matches with the given HostPort. It
// prefers a foreground match first followed by a background search if none
// existed.
func (v ServeConfigView) FindWeb(hp HostPort) (res WebServerConfigView, ok bool) {
v.Foreground().Range(func(_ string, v ServeConfigView) (cont bool) {
res, ok = v.Web().GetOk(hp)
return !ok
})
if ok {
return res, ok
}
return v.Web().GetOk(hp)
}
// HasAllowFunnel returns whether this config has at least one AllowFunnel
// set in the background or foreground configs.
func (v ServeConfigView) HasAllowFunnel() bool {
return v.AllowFunnel().Len() > 0 || func() bool {
var exists bool
v.Foreground().Range(func(k string, v ServeConfigView) (cont bool) {
exists = v.AllowFunnel().Len() > 0
return !exists
})
return exists
}()
}
// FindFunnel reports whether target exists in in either the background AllowFunnel
// or any of the foreground configs.
func (v ServeConfigView) HasFunnelForTarget(target HostPort) bool {
if v.AllowFunnel().Get(target) {
return true
}
var exists bool
v.Foreground().Range(func(_ string, v ServeConfigView) (cont bool) {
if exists = v.AllowFunnel().Get(target); exists {
return false
}
return true
})
return exists
}