tailscale/ipn/serve.go

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// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package ipn
import (
"errors"
"net"
"net/netip"
"golang.org/x/exp/slices"
"tailscale.com/tailcfg"
)
// 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"`
}
// 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
// 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"`
// 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 checks 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]
}
// IsTCPForwardingAny checks if 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 checks 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.TCP[port].HTTPS
}
// IsServingWeb checks if ServeConfig is currently serving
// Web/HTTPS on the given port.
// This is exclusive of TCPForwarding.
func (sc *ServeConfig) IsServingWeb(port uint16) bool {
if sc == nil || sc.TCP[port] == nil {
return false
}
return sc.TCP[port].HTTPS
}
// IsFunnelOn checks 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 three things: 1) an invite was used to join the
// Funnel alpha; 2) HTTPS is enabled; 3) the node has the "funnel" attribute.
// If any of these are false, an error is returned describing the problem.
//
// The nodeAttrs arg should be the node's Self.Capabilities which should contain
// the attribute we're checking for and possibly warning-capabilities for Funnel.
func CheckFunnelAccess(nodeAttrs []string) error {
if slices.Contains(nodeAttrs, tailcfg.CapabilityWarnFunnelNoInvite) {
return errors.New("Funnel not available; an invite is required to join the alpha. See https://tailscale.com/kb/1223/tailscale-funnel/.")
}
if slices.Contains(nodeAttrs, tailcfg.CapabilityWarnFunnelNoHTTPS) {
return errors.New("Funnel not available; HTTPS must be enabled. See https://tailscale.com/kb/1153/enabling-https/.")
}
if !slices.Contains(nodeAttrs, tailcfg.NodeAttrFunnel) {
return errors.New("Funnel not available; \"funnel\" node attribute not set. See https://tailscale.com/kb/1223/tailscale-funnel/.")
}
return nil
}