headscale/api.go
Kristoffer Dalby dd8c0d1e9e Move most "poll" functionality to poll.go
This function migrates more poll functions (including keepalive) to
poll.go to keep it somehow in the same file.

In addition it makes changes to improve the stability and ensure nodes
get the appropriate updates from the headscale control and are not left
in an inconsistent state.

Two new additions is:

omitpeers=true will now trigger an update if the clients are not already up
to date

keepalive has been extended with a timer that will check every 120s if
all nodes are up to date.
2021-08-18 23:24:22 +01:00

385 lines
10 KiB
Go

package headscale
import (
"encoding/binary"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"time"
"github.com/rs/zerolog/log"
"github.com/gin-gonic/gin"
"github.com/klauspost/compress/zstd"
"gorm.io/gorm"
"inet.af/netaddr"
"tailscale.com/tailcfg"
"tailscale.com/types/wgkey"
)
// KeyHandler provides the Headscale pub key
// Listens in /key
func (h *Headscale) KeyHandler(c *gin.Context) {
c.Data(200, "text/plain; charset=utf-8", []byte(h.publicKey.HexString()))
}
// RegisterWebAPI shows a simple message in the browser to point to the CLI
// Listens in /register
func (h *Headscale) RegisterWebAPI(c *gin.Context) {
mKeyStr := c.Query("key")
if mKeyStr == "" {
c.String(http.StatusBadRequest, "Wrong params")
return
}
// spew.Dump(c.Params)
c.Data(http.StatusOK, "text/html; charset=utf-8", []byte(fmt.Sprintf(`
<html>
<body>
<h1>headscale</h1>
<p>
Run the command below in the headscale server to add this machine to your network:
</p>
<p>
<code>
<b>headscale -n NAMESPACE nodes register %s</b>
</code>
</p>
</body>
</html>
`, mKeyStr)))
}
// RegistrationHandler handles the actual registration process of a machine
// Endpoint /machine/:id
func (h *Headscale) RegistrationHandler(c *gin.Context) {
body, _ := io.ReadAll(c.Request.Body)
mKeyStr := c.Param("id")
mKey, err := wgkey.ParseHex(mKeyStr)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot parse machine key")
c.String(http.StatusInternalServerError, "Sad!")
return
}
req := tailcfg.RegisterRequest{}
err = decode(body, &req, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot decode message")
c.String(http.StatusInternalServerError, "Very sad!")
return
}
now := time.Now().UTC()
var m Machine
if result := h.db.Preload("Namespace").First(&m, "machine_key = ?", mKey.HexString()); errors.Is(result.Error, gorm.ErrRecordNotFound) {
log.Info().Str("machine", req.Hostinfo.Hostname).Msg("New machine")
m = Machine{
Expiry: &req.Expiry,
MachineKey: mKey.HexString(),
Name: req.Hostinfo.Hostname,
NodeKey: wgkey.Key(req.NodeKey).HexString(),
LastSuccessfulUpdate: &now,
}
if err := h.db.Create(&m).Error; err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Could not create row")
return
}
}
if !m.Registered && req.Auth.AuthKey != "" {
h.handleAuthKey(c, h.db, mKey, req, m)
return
}
resp := tailcfg.RegisterResponse{}
// We have the updated key!
if m.NodeKey == wgkey.Key(req.NodeKey).HexString() {
if m.Registered {
log.Debug().
Str("handler", "Registration").
Str("machine", m.Name).
Msg("Client is registered and we have the current NodeKey. All clear to /map")
resp.AuthURL = ""
resp.MachineAuthorized = true
resp.User = *m.Namespace.toUser()
respBody, err := encode(resp, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
return
}
log.Debug().
Str("handler", "Registration").
Str("machine", m.Name).
Msg("Not registered and not NodeKey rotation. Sending a authurl to register")
resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
h.cfg.ServerURL, mKey.HexString())
respBody, err := encode(resp, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
return
}
// The NodeKey we have matches OldNodeKey, which means this is a refresh after an key expiration
if m.NodeKey == wgkey.Key(req.OldNodeKey).HexString() {
log.Debug().
Str("handler", "Registration").
Str("machine", m.Name).
Msg("We have the OldNodeKey in the database. This is a key refresh")
m.NodeKey = wgkey.Key(req.NodeKey).HexString()
h.db.Save(&m)
resp.AuthURL = ""
resp.User = *m.Namespace.toUser()
respBody, err := encode(resp, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "Extremely sad!")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
return
}
// We arrive here after a client is restarted without finalizing the authentication flow or
// when headscale is stopped in the middle of the auth process.
if m.Registered {
log.Debug().
Str("handler", "Registration").
Str("machine", m.Name).
Msg("The node is sending us a new NodeKey, but machine is registered. All clear for /map")
resp.AuthURL = ""
resp.MachineAuthorized = true
resp.User = *m.Namespace.toUser()
respBody, err := encode(resp, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
return
}
log.Debug().
Str("handler", "Registration").
Str("machine", m.Name).
Msg("The node is sending us a new NodeKey, sending auth url")
resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
h.cfg.ServerURL, mKey.HexString())
respBody, err := encode(resp, &mKey, h.privateKey)
if err != nil {
log.Error().
Str("handler", "Registration").
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
}
func (h *Headscale) getMapResponse(mKey wgkey.Key, req tailcfg.MapRequest, m Machine) (*[]byte, error) {
log.Trace().
Str("func", "getMapResponse").
Str("machine", req.Hostinfo.Hostname).
Msg("Creating Map response")
node, err := m.toNode()
if err != nil {
log.Error().
Str("func", "getMapResponse").
Err(err).
Msg("Cannot convert to node")
return nil, err
}
peers, err := h.getPeers(m)
if err != nil {
log.Error().
Str("func", "getMapResponse").
Err(err).
Msg("Cannot fetch peers")
return nil, err
}
profile := tailcfg.UserProfile{
ID: tailcfg.UserID(m.NamespaceID),
LoginName: m.Namespace.Name,
DisplayName: m.Namespace.Name,
}
resp := tailcfg.MapResponse{
KeepAlive: false,
Node: node,
Peers: *peers,
DNS: []netaddr.IP{},
SearchPaths: []string{},
Domain: "headscale.net",
PacketFilter: *h.aclRules,
DERPMap: h.cfg.DerpMap,
UserProfiles: []tailcfg.UserProfile{profile},
}
log.Trace().
Str("func", "getMapResponse").
Str("machine", req.Hostinfo.Hostname).
Msgf("Generated map response: %s", tailMapResponseToString(resp))
var respBody []byte
if req.Compress == "zstd" {
src, _ := json.Marshal(resp)
encoder, _ := zstd.NewWriter(nil)
srcCompressed := encoder.EncodeAll(src, nil)
respBody, err = encodeMsg(srcCompressed, &mKey, h.privateKey)
if err != nil {
return nil, err
}
} else {
respBody, err = encode(resp, &mKey, h.privateKey)
if err != nil {
return nil, err
}
}
// spew.Dump(resp)
// declare the incoming size on the first 4 bytes
data := make([]byte, 4)
binary.LittleEndian.PutUint32(data, uint32(len(respBody)))
data = append(data, respBody...)
return &data, nil
}
func (h *Headscale) getMapKeepAliveResponse(mKey wgkey.Key, req tailcfg.MapRequest, m Machine) (*[]byte, error) {
resp := tailcfg.MapResponse{
KeepAlive: true,
}
var respBody []byte
var err error
if req.Compress == "zstd" {
src, _ := json.Marshal(resp)
encoder, _ := zstd.NewWriter(nil)
srcCompressed := encoder.EncodeAll(src, nil)
respBody, err = encodeMsg(srcCompressed, &mKey, h.privateKey)
if err != nil {
return nil, err
}
} else {
respBody, err = encode(resp, &mKey, h.privateKey)
if err != nil {
return nil, err
}
}
data := make([]byte, 4)
binary.LittleEndian.PutUint32(data, uint32(len(respBody)))
data = append(data, respBody...)
return &data, nil
}
func (h *Headscale) handleAuthKey(c *gin.Context, db *gorm.DB, idKey wgkey.Key, req tailcfg.RegisterRequest, m Machine) {
log.Debug().
Str("func", "handleAuthKey").
Str("machine", req.Hostinfo.Hostname).
Msgf("Processing auth key for %s", req.Hostinfo.Hostname)
resp := tailcfg.RegisterResponse{}
pak, err := h.checkKeyValidity(req.Auth.AuthKey)
if err != nil {
resp.MachineAuthorized = false
respBody, err := encode(resp, &idKey, h.privateKey)
if err != nil {
log.Error().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
log.Error().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Msg("Failed authentication via AuthKey")
return
}
log.Debug().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Msg("Authentication key was valid, proceeding to acquire an IP address")
ip, err := h.getAvailableIP()
if err != nil {
log.Error().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Msg("Failed to find an available IP")
return
}
log.Info().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Str("ip", ip.String()).
Msgf("Assigning %s to %s", ip, m.Name)
m.AuthKeyID = uint(pak.ID)
m.IPAddress = ip.String()
m.NamespaceID = pak.NamespaceID
m.NodeKey = wgkey.Key(req.NodeKey).HexString() // we update it just in case
m.Registered = true
m.RegisterMethod = "authKey"
db.Save(&m)
resp.MachineAuthorized = true
resp.User = *pak.Namespace.toUser()
respBody, err := encode(resp, &idKey, h.privateKey)
if err != nil {
log.Error().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Err(err).
Msg("Cannot encode message")
c.String(http.StatusInternalServerError, "Extremely sad!")
return
}
c.Data(200, "application/json; charset=utf-8", respBody)
log.Info().
Str("func", "handleAuthKey").
Str("machine", m.Name).
Str("ip", ip.String()).
Msg("Successfully authenticated via AuthKey")
}