sftpgo-mirror/webdavd/server.go
2020-08-15 15:55:20 +02:00

258 lines
8 KiB
Go

package webdavd
import (
"context"
"crypto/tls"
"errors"
"fmt"
"net/http"
"path"
"path/filepath"
"strings"
"time"
"github.com/rs/cors"
"github.com/rs/xid"
"golang.org/x/net/webdav"
"github.com/drakkan/sftpgo/common"
"github.com/drakkan/sftpgo/dataprovider"
"github.com/drakkan/sftpgo/logger"
"github.com/drakkan/sftpgo/metrics"
"github.com/drakkan/sftpgo/utils"
)
var (
err401 = errors.New("Unauthorized")
err403 = errors.New("Forbidden")
xForwardedFor = http.CanonicalHeaderKey("X-Forwarded-For")
xRealIP = http.CanonicalHeaderKey("X-Real-IP")
)
type webDavServer struct {
config *Configuration
certMgr *common.CertManager
}
func newServer(config *Configuration, configDir string) (*webDavServer, error) {
var err error
server := &webDavServer{
config: config,
certMgr: nil,
}
certificateFile := getConfigPath(config.CertificateFile, configDir)
certificateKeyFile := getConfigPath(config.CertificateKeyFile, configDir)
if len(certificateFile) > 0 && len(certificateKeyFile) > 0 {
server.certMgr, err = common.NewCertManager(certificateFile, certificateKeyFile, logSender)
if err != nil {
return server, err
}
}
return server, nil
}
func (s *webDavServer) listenAndServe() error {
httpServer := &http.Server{
Addr: fmt.Sprintf("%s:%d", s.config.BindAddress, s.config.BindPort),
Handler: server,
ReadHeaderTimeout: 30 * time.Second,
IdleTimeout: 120 * time.Second,
MaxHeaderBytes: 1 << 16, // 64KB
}
if s.config.Cors.Enabled {
c := cors.New(cors.Options{
AllowedOrigins: s.config.Cors.AllowedOrigins,
AllowedMethods: s.config.Cors.AllowedMethods,
AllowedHeaders: s.config.Cors.AllowedHeaders,
ExposedHeaders: s.config.Cors.ExposedHeaders,
MaxAge: s.config.Cors.MaxAge,
AllowCredentials: s.config.Cors.AllowCredentials,
OptionsPassthrough: true,
})
httpServer.Handler = c.Handler(server)
} else {
httpServer.Handler = server
}
if s.certMgr != nil {
httpServer.TLSConfig = &tls.Config{
GetCertificate: s.certMgr.GetCertificateFunc(),
MinVersion: tls.VersionTLS12,
}
return httpServer.ListenAndServeTLS("", "")
}
return httpServer.ListenAndServe()
}
// ServeHTTP implements the http.Handler interface
func (s *webDavServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
checkRemoteAddress(r)
if err := common.Config.ExecutePostConnectHook(r.RemoteAddr, common.ProtocolWebDAV); err != nil {
http.Error(w, common.ErrConnectionDenied.Error(), http.StatusForbidden)
return
}
user, err := s.authenticate(r)
if err != nil {
w.Header().Set("WWW-Authenticate", "Basic realm=\"SFTPGo WebDAV\"")
http.Error(w, err401.Error(), http.StatusUnauthorized)
return
}
connectionID, err := s.validateUser(user, r)
if err != nil {
updateLoginMetrics(user.Username, r.RemoteAddr, err)
http.Error(w, err.Error(), http.StatusForbidden)
return
}
fs, err := user.GetFilesystem(connectionID)
if err != nil {
updateLoginMetrics(user.Username, r.RemoteAddr, err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
updateLoginMetrics(user.Username, r.RemoteAddr, err)
ctx := context.WithValue(r.Context(), requestIDKey, connectionID)
ctx = context.WithValue(ctx, requestStartKey, time.Now())
connection := &Connection{
BaseConnection: common.NewBaseConnection(connectionID, common.ProtocolWebDAV, user, fs),
request: r,
}
common.Connections.Add(connection)
defer common.Connections.Remove(connection.GetID())
connection.Fs.CheckRootPath(connection.GetUsername(), user.GetUID(), user.GetGID())
connection.Log(logger.LevelInfo, "User id: %d, logged in with WebDAV, method: %v, username: %#v, home_dir: %#v remote addr: %#v",
user.ID, r.Method, user.Username, user.HomeDir, r.RemoteAddr)
dataprovider.UpdateLastLogin(user) //nolint:errcheck
prefix := path.Join("/", user.Username)
// see RFC4918, section 9.4
if r.Method == "GET" {
p := strings.TrimPrefix(path.Clean(r.URL.Path), prefix)
info, err := connection.Stat(ctx, p)
if err == nil && info.IsDir() {
r.Method = "PROPFIND"
if r.Header.Get("Depth") == "" {
r.Header.Add("Depth", "1")
}
}
}
handler := webdav.Handler{
Prefix: prefix,
FileSystem: connection,
LockSystem: webdav.NewMemLS(),
Logger: writeLog,
}
handler.ServeHTTP(w, r.WithContext(ctx))
}
func (s *webDavServer) authenticate(r *http.Request) (dataprovider.User, error) {
var user dataprovider.User
var err error
username, password, ok := r.BasicAuth()
if !ok {
return user, err401
}
user, err = dataprovider.CheckUserAndPass(username, password, utils.GetIPFromRemoteAddress(r.RemoteAddr), common.ProtocolWebDAV)
if err != nil {
updateLoginMetrics(username, r.RemoteAddr, err)
return user, err
}
return user, err
}
func (s *webDavServer) validateUser(user dataprovider.User, r *http.Request) (string, error) {
connID := xid.New().String()
connectionID := fmt.Sprintf("%v_%v", common.ProtocolWebDAV, connID)
uriSegments := strings.Split(path.Clean(r.URL.Path), "/")
if len(uriSegments) < 2 || uriSegments[1] != user.Username {
logger.Debug(logSender, connectionID, "URI %#v not allowed for user %#v", r.URL.Path, user.Username)
return connID, err403
}
if !filepath.IsAbs(user.HomeDir) {
logger.Warn(logSender, connectionID, "user %#v has an invalid home dir: %#v. Home dir must be an absolute path, login not allowed",
user.Username, user.HomeDir)
return connID, fmt.Errorf("cannot login user with invalid home dir: %#v", user.HomeDir)
}
if user.MaxSessions > 0 {
activeSessions := common.Connections.GetActiveSessions(user.Username)
if activeSessions >= user.MaxSessions {
logger.Debug(logSender, connID, "authentication refused for user: %#v, too many open sessions: %v/%v", user.Username,
activeSessions, user.MaxSessions)
return connID, fmt.Errorf("too many open sessions: %v", activeSessions)
}
}
if dataprovider.GetQuotaTracking() > 0 && user.HasOverlappedMappedPaths() {
logger.Debug(logSender, connectionID, "cannot login user %#v, overlapping mapped folders are allowed only with quota tracking disabled",
user.Username)
return connID, errors.New("overlapping mapped folders are allowed only with quota tracking disabled")
}
if !user.IsLoginFromAddrAllowed(r.RemoteAddr) {
logger.Debug(logSender, connectionID, "cannot login user %#v, remote address is not allowed: %v", user.Username, r.RemoteAddr)
return connID, fmt.Errorf("Login for user %#v is not allowed from this address: %v", user.Username, r.RemoteAddr)
}
return connID, nil
}
func writeLog(r *http.Request, err error) {
scheme := "http"
if r.TLS != nil {
scheme = "https"
}
fields := map[string]interface{}{
"remote_addr": r.RemoteAddr,
"proto": r.Proto,
"method": r.Method,
"user_agent": r.UserAgent(),
"uri": fmt.Sprintf("%s://%s%s", scheme, r.Host, r.RequestURI)}
if reqID, ok := r.Context().Value(requestIDKey).(string); ok {
fields["request_id"] = reqID
}
if reqStart, ok := r.Context().Value(requestStartKey).(time.Time); ok {
fields["elapsed_ms"] = time.Since(reqStart).Nanoseconds() / 1000000
}
logger.GetLogger().Info().
Timestamp().
Str("sender", logSender).
Fields(fields).
Err(err).
Msg("")
}
func checkRemoteAddress(r *http.Request) {
if common.Config.ProxyProtocol != 0 {
return
}
var ip string
if xrip := r.Header.Get(xRealIP); xrip != "" {
ip = xrip
} else if xff := r.Header.Get(xForwardedFor); xff != "" {
i := strings.Index(xff, ", ")
if i == -1 {
i = len(xff)
}
ip = strings.TrimSpace(xff[:i])
}
if len(ip) > 0 {
r.RemoteAddr = ip
}
}
func updateLoginMetrics(username, remoteAddress string, err error) {
metrics.AddLoginAttempt(dataprovider.LoginMethodPassword)
ip := utils.GetIPFromRemoteAddress(remoteAddress)
if err != nil {
logger.ConnectionFailedLog(username, ip, dataprovider.LoginMethodPassword, common.ProtocolWebDAV, err.Error())
}
metrics.AddLoginResult(dataprovider.LoginMethodPassword, err)
dataprovider.ExecutePostLoginHook(username, dataprovider.LoginMethodPassword, ip, common.ProtocolWebDAV, err)
}