package headscale
import (
"bytes"
"encoding/json"
"fmt"
"html/template"
"net/http"
"strings"
"time"
"github.com/gorilla/mux"
"github.com/rs/zerolog/log"
"tailscale.com/tailcfg"
"tailscale.com/types/key"
)
const (
// TODO(juan): remove this once https://github.com/juanfont/headscale/issues/727 is fixed.
registrationHoldoff = time.Second * 5
reservedResponseHeaderSize = 4
RegisterMethodAuthKey = "authkey"
RegisterMethodOIDC = "oidc"
RegisterMethodCLI = "cli"
ErrRegisterMethodCLIDoesNotSupportExpire = Error(
"machines registered with CLI does not support expire",
)
// The CapabilityVersion is used by Tailscale clients to indicate
// their codebase version. Tailscale clients can communicate over TS2021
// from CapabilityVersion 28.
// See https://github.com/tailscale/tailscale/blob/main/tailcfg/tailcfg.go
NoiseCapabilityVersion = 28
)
func (h *Headscale) HealthHandler(
writer http.ResponseWriter,
req *http.Request,
) {
respond := func(err error) {
writer.Header().Set("Content-Type", "application/health+json; charset=utf-8")
res := struct {
Status string `json:"status"`
}{
Status: "pass",
}
if err != nil {
writer.WriteHeader(http.StatusInternalServerError)
log.Error().Caller().Err(err).Msg("health check failed")
res.Status = "fail"
}
buf, err := json.Marshal(res)
if err != nil {
log.Error().Caller().Err(err).Msg("marshal failed")
}
_, err = writer.Write(buf)
if err != nil {
log.Error().Caller().Err(err).Msg("write failed")
}
}
if err := h.pingDB(); err != nil {
respond(err)
return
}
respond(nil)
}
type registerWebAPITemplateConfig struct {
Key string
}
var registerWebAPITemplate = template.Must(
template.New("registerweb").Parse(`
<html>
<head>
<title>Registration - Headscale</title>
</head>
<body>
<h1>headscale</h1>
<h2>Machine registration</h2>
<p>
Run the command below in the headscale server to add this machine to your network:
</p>
<pre><code>headscale -n NAMESPACE nodes register --key {{.Key}}</code></pre>
</body>
</html>
`))
// RegisterWebAPI shows a simple message in the browser to point to the CLI
// Listens in /register/:nkey.
//
// This is not part of the Tailscale control API, as we could send whatever URL
// in the RegisterResponse.AuthURL field.
func (h *Headscale) RegisterWebAPI(
writer http.ResponseWriter,
req *http.Request,
) {
vars := mux.Vars(req)
nodeKeyStr, ok := vars["nkey"]
if !ok || nodeKeyStr == "" {
writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
writer.WriteHeader(http.StatusBadRequest)
_, err := writer.Write([]byte("Wrong params"))
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
return
}
var content bytes.Buffer
if err := registerWebAPITemplate.Execute(&content, registerWebAPITemplateConfig{
Key: nodeKeyStr,
}); err != nil {
log.Error().
Str("func", "RegisterWebAPI").
Err(err).
Msg("Could not render register web API template")
writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
writer.WriteHeader(http.StatusInternalServerError)
_, err = writer.Write([]byte("Could not render register web API template"))
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
return
}
writer.Header().Set("Content-Type", "text/html; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err := writer.Write(content.Bytes())
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
func (h *Headscale) handleMachineLogOut(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
log.Info().
Str("machine", machine.Hostname).
Msg("Client requested logout")
err := h.ExpireMachine(&machine)
if err != nil {
log.Error().
Caller().
Str("func", "handleMachineLogOut").
Err(err).
Msg("Failed to expire machine")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
resp.AuthURL = ""
resp.MachineAuthorized = false
resp.User = *machine.Namespace.toUser()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
func (h *Headscale) handleMachineValidRegistration(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
// The machine registration is valid, respond with redirect to /map
log.Debug().
Str("machine", machine.Hostname).
Msg("Client is registered and we have the current NodeKey. All clear to /map")
resp.AuthURL = ""
resp.MachineAuthorized = true
resp.User = *machine.Namespace.toUser()
resp.Login = *machine.Namespace.toLogin()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("update", "web", "error", machine.Namespace.Name).
Inc()
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
machineRegistrations.WithLabelValues("update", "web", "success", machine.Namespace.Name).
Inc()
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
func (h *Headscale) handleMachineExpired(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
// The client has registered before, but has expired
log.Debug().
Str("machine", machine.Hostname).
Msg("Machine registration has expired. Sending a authurl to register")
if registerRequest.Auth.AuthKey != "" {
h.handleAuthKey(writer, req, machineKey, registerRequest)
return
}
if h.cfg.OIDC.Issuer != "" {
resp.AuthURL = fmt.Sprintf("%s/oidc/register/%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"),
NodePublicKeyStripPrefix(registerRequest.NodeKey))
} else {
resp.AuthURL = fmt.Sprintf("%s/register/%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"),
NodePublicKeyStripPrefix(registerRequest.NodeKey))
}
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("reauth", "web", "error", machine.Namespace.Name).
Inc()
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
machineRegistrations.WithLabelValues("reauth", "web", "success", machine.Namespace.Name).
Inc()
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
func (h *Headscale) handleMachineRefreshKey(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
log.Debug().
Str("machine", machine.Hostname).
Msg("We have the OldNodeKey in the database. This is a key refresh")
machine.NodeKey = NodePublicKeyStripPrefix(registerRequest.NodeKey)
if err := h.db.Save(&machine).Error; err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to update machine key in the database")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
resp.AuthURL = ""
resp.User = *machine.Namespace.toUser()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
func (h *Headscale) handleMachineRegistrationNew(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
) {
resp := tailcfg.RegisterResponse{}
// The machine registration is new, redirect the client to the registration URL
log.Debug().
Caller().
Str("machine", registerRequest.Hostinfo.Hostname).
Msg("The node seems to be new, sending auth url")
if h.cfg.OIDC.Issuer != "" {
resp.AuthURL = fmt.Sprintf(
"%s/oidc/register/%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"),
NodePublicKeyStripPrefix(registerRequest.NodeKey),
)
} else {
resp.AuthURL = fmt.Sprintf("%s/register/%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"),
NodePublicKeyStripPrefix(registerRequest.NodeKey))
}
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
}
// TODO: check if any locks are needed around IP allocation.
func (h *Headscale) handleAuthKey(
writer http.ResponseWriter,
req *http.Request,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
) {
machineKeyStr := MachinePublicKeyStripPrefix(machineKey)
log.Debug().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msgf("Processing auth key for %s", registerRequest.Hostinfo.Hostname)
resp := tailcfg.RegisterResponse{}
pak, err := h.checkKeyValidity(registerRequest.Auth.AuthKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Failed authentication via AuthKey")
resp.MachineAuthorized = false
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Cannot encode message")
http.Error(writer, "Internal server error", http.StatusInternalServerError)
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
return
}
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusUnauthorized)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msg("Failed authentication via AuthKey")
if pak != nil {
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
} else {
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", "unknown").Inc()
}
return
}
log.Debug().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msg("Authentication key was valid, proceeding to acquire IP addresses")
nodeKey := NodePublicKeyStripPrefix(registerRequest.NodeKey)
// retrieve machine information if it exist
// The error is not important, because if it does not
// exist, then this is a new machine and we will move
// on to registration.
machine, _ := h.GetMachineByMachineKey(machineKey)
if machine != nil {
log.Trace().
Caller().
Str("machine", machine.Hostname).
Msg("machine already registered, refreshing with new auth key")
machine.NodeKey = nodeKey
machine.AuthKeyID = uint(pak.ID)
err := h.RefreshMachine(machine, registerRequest.Expiry)
if err != nil {
log.Error().
Caller().
Str("machine", machine.Hostname).
Err(err).
Msg("Failed to refresh machine")
return
}
} else {
now := time.Now().UTC()
givenName, err := h.GenerateGivenName(registerRequest.Hostinfo.Hostname)
if err != nil {
log.Error().
Caller().
Str("func", "RegistrationHandler").
Str("hostinfo.name", registerRequest.Hostinfo.Hostname).
Err(err)
return
}
machineToRegister := Machine{
Hostname: registerRequest.Hostinfo.Hostname,
GivenName: givenName,
NamespaceID: pak.Namespace.ID,
MachineKey: machineKeyStr,
RegisterMethod: RegisterMethodAuthKey,
Expiry: ®isterRequest.Expiry,
NodeKey: nodeKey,
LastSeen: &now,
AuthKeyID: uint(pak.ID),
}
machine, err = h.RegisterMachine(
machineToRegister,
)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("could not register machine")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
}
err = h.UsePreAuthKey(pak)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to use pre-auth key")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
resp.MachineAuthorized = true
resp.User = *pak.Namespace.toUser()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
http.Error(writer, "Internal server error", http.StatusInternalServerError)
return
}
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "success", pak.Namespace.Name).
Inc()
writer.Header().Set("Content-Type", "application/json; charset=utf-8")
writer.WriteHeader(http.StatusOK)
_, err = writer.Write(respBody)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Failed to write response")
}
log.Info().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Str("ips", strings.Join(machine.IPAddresses.ToStringSlice(), ", ")).
Msg("Successfully authenticated via AuthKey")
}