// Copyright 2018 The goftp Authors. All rights reserved.// Use of this source code is governed by a MIT-style// license that can be found in the LICENSE file. package server import ( "bufio" "context" "crypto/tls" "errors" "fmt" "net" "strconv") // Version returns the library versionfunc Version() string { return "0.3.0"} // ServerOpts contains parameters for server.NewServer()type ServerOpts struct { // The factory that will be used to create a new FTPDriver instance for // each client connection. This is a mandatory option. Factory DriverFactory Auth Auth // Server Name, Default is Go Ftp Server Name string // The hostname that the FTP server should listen on. Optional, defaults to // "::", which means all hostnames on ipv4 and ipv6. Hostname string // Public IP of the server PublicIp string // Passive ports PassivePorts string // The port that the FTP should listen on. Optional, defaults to 3000. In // a production environment you will probably want to change this to 21. Port int // use tls, default is false TLS bool // if tls used, cert file is required CertFile string // if tls used, key file is required KeyFile string // If ture TLS is used in RFC4217 mode ExplicitFTPS bool WelcomeMessage string // A logger implementation, if nil the StdLogger is used Logger Logger} // Server is the root of your FTP application. You should instantiate one// of these and call ListenAndServe() to start accepting client connections.//// Always use the NewServer() method to create a new Server.type Server struct { *ServerOpts listenTo string logger Logger listener net.Listener tlsConfig *tls.Config ctx context.Context cancel context.CancelFunc feats string} // ErrServerClosed is returned by ListenAndServe() or Serve() when a shutdown// was requested.var ErrServerClosed = errors.New("ftp: Server closed") // serverOptsWithDefaults copies an ServerOpts struct into a new struct,// then adds any default values that are missing and returns the new data.func serverOptsWithDefaults(opts *ServerOpts) *ServerOpts { var newOpts ServerOpts if opts == nil { opts = &ServerOpts{} } if opts.Hostname == "" { newOpts.Hostname = "::" } else { newOpts.Hostname = opts.Hostname } if opts.Port == 0 { newOpts.Port = 3000 } else { newOpts.Port = opts.Port } newOpts.Factory = opts.Factory if opts.Name == "" { newOpts.Name = "Go FTP Server" } else { newOpts.Name = opts.Name } if opts.WelcomeMessage == "" { newOpts.WelcomeMessage = defaultWelcomeMessage } else { newOpts.WelcomeMessage = opts.WelcomeMessage } if opts.Auth != nil { newOpts.Auth = opts.Auth } newOpts.Logger = &StdLogger{} if opts.Logger != nil { newOpts.Logger = opts.Logger } newOpts.TLS = opts.TLS newOpts.KeyFile = opts.KeyFile newOpts.CertFile = opts.CertFile newOpts.ExplicitFTPS = opts.ExplicitFTPS newOpts.PublicIp = opts.PublicIp newOpts.PassivePorts = opts.PassivePorts return &newOpts} // NewServer initialises a new FTP server. Configuration options are provided// via an instance of ServerOpts. Calling this function in your code will// probably look something like this://// factory := &MyDriverFactory{}// server := server.NewServer(&server.ServerOpts{ Factory: factory })//// or://// factory := &MyDriverFactory{}// opts := &server.ServerOpts{// Factory: factory,// Port: 2000,// Hostname: "127.0.0.1",// }// server := server.NewServer(opts)//func NewServer(opts *ServerOpts) *Server { opts = serverOptsWithDefaults(opts) s := new(Server) s.ServerOpts = opts s.listenTo = net.JoinHostPort(opts.Hostname, strconv.Itoa(opts.Port)) s.logger = opts.Logger return s} // NewConn constructs a new object that will handle the FTP protocol over// an active net.TCPConn. The TCP connection should already be open before// it is handed to this functions. driver is an instance of FTPDriver that// will handle all auth and persistence details.func (server *Server) newConn(tcpConn net.Conn, driver Driver) *Conn { c := new(Conn) c.namePrefix = "/" c.conn = tcpConn c.controlReader = bufio.NewReader(tcpConn) c.controlWriter = bufio.NewWriter(tcpConn) c.driver = driver c.auth = server.Auth c.server = server c.sessionID = newSessionID() c.logger = server.logger c.tlsConfig = server.tlsConfig driver.Init(c) return c} func simpleTLSConfig(certFile, keyFile string) (*tls.Config, error) { config := &tls.Config{} if config.NextProtos == nil { config.NextProtos = []string{"ftp"} } var err error config.Certificates = make([]tls.Certificate, 1) config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile) if err != nil { return nil, err } return config, nil} // ListenAndServe asks a new Server to begin accepting client connections. It// accepts no arguments - all configuration is provided via the NewServer// function.//// If the server fails to start for any reason, an error will be returned. Common// errors are trying to bind to a privileged port or something else is already// listening on the same port.//func (server *Server) ListenAndServe() error { var listener net.Listener var err error var curFeats = featCmds if server.ServerOpts.TLS { server.tlsConfig, err = simpleTLSConfig(server.CertFile, server.KeyFile) if err != nil { return err } curFeats += " AUTH TLS\n PBSZ\n PROT\n" if server.ServerOpts.ExplicitFTPS { listener, err = net.Listen("tcp", server.listenTo) } else { listener, err = tls.Listen("tcp", server.listenTo, server.tlsConfig) } } else { listener, err = net.Listen("tcp", server.listenTo) } if err != nil { return err } server.feats = fmt.Sprintf(feats, curFeats) sessionID := "" server.logger.Printf(sessionID, "%s listening on %d", server.Name, server.Port) return server.Serve(listener)} // Serve accepts connections on a given net.Listener and handles each// request in a new goroutine.//func (server *Server) Serve(l net.Listener) error { server.listener = l server.ctx, server.cancel = context.WithCancel(context.Background()) sessionID := "" for { tcpConn, err := server.listener.Accept() if err != nil { select { case <-server.ctx.Done(): return ErrServerClosed default: } server.logger.Printf(sessionID, "listening error: %v", err) if ne, ok := err.(net.Error); ok && ne.Temporary() { continue } return err } driver, err := server.Factory.NewDriver() if err != nil { server.logger.Printf(sessionID, "Error creating driver, aborting client connection: %v", err) tcpConn.Close() } else { ftpConn := server.newConn(tcpConn, driver) go ftpConn.Serve() } }} // Shutdown will gracefully stop a server. Already connected clients will retain their connectionsfunc (server *Server) Shutdown() error { if server.cancel != nil { server.cancel() } if server.listener != nil { return server.listener.Close() } // server wasnt even started return nil}
// Copyright 2018 The goftp Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package server
import (
"bufio"
"context"
"crypto/tls"
"errors"
"fmt"
"net"
"strconv"
)
// Version returns the library version
func Version() string {
return "0.3.0"
}
// ServerOpts contains parameters for server.NewServer()
type ServerOpts struct {
// The factory that will be used to create a new FTPDriver instance for
// each client connection. This is a mandatory option.
Factory DriverFactory
Auth Auth
// Server Name, Default is Go Ftp Server
Name string
// The hostname that the FTP server should listen on. Optional, defaults to
// "::", which means all hostnames on ipv4 and ipv6.
Hostname string
// Public IP of the server
PublicIp string
// Passive ports
PassivePorts string
// The port that the FTP should listen on. Optional, defaults to 3000. In
// a production environment you will probably want to change this to 21.
Port int
// use tls, default is false
TLS bool
// if tls used, cert file is required
CertFile string
// if tls used, key file is required
KeyFile string
// If ture TLS is used in RFC4217 mode
ExplicitFTPS bool
WelcomeMessage string
// A logger implementation, if nil the StdLogger is used
Logger Logger
}
// Server is the root of your FTP application. You should instantiate one
// of these and call ListenAndServe() to start accepting client connections.
//
// Always use the NewServer() method to create a new Server.
type Server struct {
*ServerOpts
listenTo string
logger Logger
listener net.Listener
tlsConfig *tls.Config
ctx context.Context
cancel context.CancelFunc
feats string
}
// ErrServerClosed is returned by ListenAndServe() or Serve() when a shutdown
// was requested.
var ErrServerClosed = errors.New("ftp: Server closed")
// serverOptsWithDefaults copies an ServerOpts struct into a new struct,
// then adds any default values that are missing and returns the new data.
func serverOptsWithDefaults(opts *ServerOpts) *ServerOpts {
var newOpts ServerOpts
if opts == nil {
opts = &ServerOpts{}
}
if opts.Hostname == "" {
newOpts.Hostname = "::"
} else {
newOpts.Hostname = opts.Hostname
}
if opts.Port == 0 {
newOpts.Port = 3000
} else {
newOpts.Port = opts.Port
}
newOpts.Factory = opts.Factory
if opts.Name == "" {
newOpts.Name = "Go FTP Server"
} else {
newOpts.Name = opts.Name
}
if opts.WelcomeMessage == "" {
newOpts.WelcomeMessage = defaultWelcomeMessage
} else {
newOpts.WelcomeMessage = opts.WelcomeMessage
}
if opts.Auth != nil {
newOpts.Auth = opts.Auth
}
newOpts.Logger = &StdLogger{}
if opts.Logger != nil {
newOpts.Logger = opts.Logger
}
newOpts.TLS = opts.TLS
newOpts.KeyFile = opts.KeyFile
newOpts.CertFile = opts.CertFile
newOpts.ExplicitFTPS = opts.ExplicitFTPS
newOpts.PublicIp = opts.PublicIp
newOpts.PassivePorts = opts.PassivePorts
return &newOpts
}
// NewServer initialises a new FTP server. Configuration options are provided
// via an instance of ServerOpts. Calling this function in your code will
// probably look something like this:
//
// factory := &MyDriverFactory{}
// server := server.NewServer(&server.ServerOpts{ Factory: factory })
//
// or:
//
// factory := &MyDriverFactory{}
// opts := &server.ServerOpts{
// Factory: factory,
// Port: 2000,
// Hostname: "127.0.0.1",
// }
// server := server.NewServer(opts)
//
func NewServer(opts *ServerOpts) *Server {
opts = serverOptsWithDefaults(opts)
s := new(Server)
s.ServerOpts = opts
s.listenTo = net.JoinHostPort(opts.Hostname, strconv.Itoa(opts.Port))
s.logger = opts.Logger
return s
}
// NewConn constructs a new object that will handle the FTP protocol over
// an active net.TCPConn. The TCP connection should already be open before
// it is handed to this functions. driver is an instance of FTPDriver that
// will handle all auth and persistence details.
func (server *Server) newConn(tcpConn net.Conn, driver Driver) *Conn {
c := new(Conn)
c.namePrefix = "/"
c.conn = tcpConn
c.controlReader = bufio.NewReader(tcpConn)
c.controlWriter = bufio.NewWriter(tcpConn)
c.driver = driver
c.auth = server.Auth
c.server = server
c.sessionID = newSessionID()
c.logger = server.logger
c.tlsConfig = server.tlsConfig
driver.Init(c)
return c
}
func simpleTLSConfig(certFile, keyFile string) (*tls.Config, error) {
config := &tls.Config{}
if config.NextProtos == nil {
config.NextProtos = []string{"ftp"}
}
var err error
config.Certificates = make([]tls.Certificate, 1)
config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
return nil, err
}
return config, nil
}
// ListenAndServe asks a new Server to begin accepting client connections. It
// accepts no arguments - all configuration is provided via the NewServer
// function.
//
// If the server fails to start for any reason, an error will be returned. Common
// errors are trying to bind to a privileged port or something else is already
// listening on the same port.
//
func (server *Server) ListenAndServe() error {
var listener net.Listener
var err error
var curFeats = featCmds
if server.ServerOpts.TLS {
server.tlsConfig, err = simpleTLSConfig(server.CertFile, server.KeyFile)
if err != nil {
return err
}
curFeats += " AUTH TLS\n PBSZ\n PROT\n"
if server.ServerOpts.ExplicitFTPS {
listener, err = net.Listen("tcp", server.listenTo)
} else {
listener, err = tls.Listen("tcp", server.listenTo, server.tlsConfig)
}
} else {
listener, err = net.Listen("tcp", server.listenTo)
}
if err != nil {
return err
}
server.feats = fmt.Sprintf(feats, curFeats)
sessionID := ""
server.logger.Printf(sessionID, "%s listening on %d", server.Name, server.Port)
return server.Serve(listener)
}
// Serve accepts connections on a given net.Listener and handles each
// request in a new goroutine.
//
func (server *Server) Serve(l net.Listener) error {
server.listener = l
server.ctx, server.cancel = context.WithCancel(context.Background())
sessionID := ""
for {
tcpConn, err := server.listener.Accept()
if err != nil {
select {
case <-server.ctx.Done():
return ErrServerClosed
default:
}
server.logger.Printf(sessionID, "listening error: %v", err)
if ne, ok := err.(net.Error); ok && ne.Temporary() {
continue
}
return err
}
driver, err := server.Factory.NewDriver()
if err != nil {
server.logger.Printf(sessionID, "Error creating driver, aborting client connection: %v", err)
tcpConn.Close()
} else {
ftpConn := server.newConn(tcpConn, driver)
go ftpConn.Serve()
}
}
}
// Shutdown will gracefully stop a server. Already connected clients will retain their connections
func (server *Server) Shutdown() error {
if server.cancel != nil {
server.cancel()
}
if server.listener != nil {
return server.listener.Close()
}
// server wasnt even started
return nil
}