chore(deps): update actions/setup-go action to v4 (#3858)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/auto_lang.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ${{ matrix.platform }}
     steps:
       - name: Setup go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go-version }}
 

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ${{ matrix.platform }}
     steps:
       - name: Setup Go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go-version }}
 

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
           prerelease: true
 
       - name: Setup Go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go-version }}
 

Dockerfile

@@ -15,4 +15,4 @@ RUN apk add --no-cache bash ca-certificates su-exec tzdata; \
     chmod +x /entrypoint.sh
 ENV PUID=0 PGID=0 UMASK=022
 EXPOSE 5244
-ENTRYPOINT [ "/entrypoint.sh" ]
+CMD [ "/entrypoint.sh" ]

drivers/115/meta.go

@@ -6,8 +6,9 @@ import (
 )
 
 type Addition struct {
-	Cookie      string `json:"cookie"`
-	QRCodeToken string `json:"qrcode_token"`
+	Cookie      string `json:"cookie" type:"text" help:"one of QR code token and cookie required"`
+	QRCodeToken string `json:"qrcode_token" type:"text" help:"one of QR code token and cookie required"`
+	PageSize    int64  `json:"page_size" type:"number" default:"56" help:"list api per page size of 115 driver"`
 	driver.RootID
 }
 

drivers/115/util.go

@@ -7,7 +7,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-var UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36 115Browser/23.9.3.2 115disk/30.1.0"
+var UserAgent = driver.UA115Desktop
 
 func (d *Pan115) login() error {
 	var err error
@@ -38,7 +38,10 @@ func (d *Pan115) login() error {
 
 func (d *Pan115) getFiles(fileId string) ([]driver.File, error) {
 	res := make([]driver.File, 0)
-	files, err := d.client.List(fileId)
+	if d.PageSize <= 0 {
+		d.PageSize = driver.FileListLimit
+	}
+	files, err := d.client.ListWithLimit(fileId, d.PageSize)
 	if err != nil {
 		return nil, err
 	}

drivers/alias/driver.go

@@ -0,0 +1,114 @@
+package alias
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/alist-org/alist/v3/internal/driver"
+	"github.com/alist-org/alist/v3/internal/errs"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/pkg/utils"
+)
+
+type Alias struct {
+	model.Storage
+	Addition
+	pathMap     map[string][]string
+	autoFlatten bool
+	oneKey      string
+}
+
+func (d *Alias) Config() driver.Config {
+	return config
+}
+
+func (d *Alias) GetAddition() driver.Additional {
+	return &d.Addition
+}
+
+func (d *Alias) Init(ctx context.Context) error {
+	if d.Paths == "" {
+		return errors.New("paths is required")
+	}
+	d.pathMap = make(map[string][]string)
+	for _, path := range strings.Split(d.Paths, "\n") {
+		path = strings.TrimSpace(path)
+		if path == "" {
+			continue
+		}
+		k, v := getPair(path)
+		d.pathMap[k] = append(d.pathMap[k], v)
+	}
+	if len(d.pathMap) == 1 {
+		for k := range d.pathMap {
+			d.oneKey = k
+		}
+		d.autoFlatten = true
+	}
+	return nil
+}
+
+func (d *Alias) Drop(ctx context.Context) error {
+	d.pathMap = nil
+	return nil
+}
+
+func (d *Alias) Get(ctx context.Context, path string) (model.Obj, error) {
+	if utils.PathEqual(path, "/") {
+		return &model.Object{
+			Name:     "Root",
+			IsFolder: true,
+			Path:     "/",
+		}, nil
+	}
+	root, sub := d.getRootAndPath(path)
+	dsts, ok := d.pathMap[root]
+	if !ok {
+		return nil, errs.ObjectNotFound
+	}
+	for _, dst := range dsts {
+		obj, err := d.get(ctx, path, dst, sub)
+		if err == nil {
+			return obj, nil
+		}
+	}
+	return nil, errs.ObjectNotFound
+}
+
+func (d *Alias) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([]model.Obj, error) {
+	path := dir.GetPath()
+	if utils.PathEqual(path, "/") && !d.autoFlatten {
+		return d.listRoot(), nil
+	}
+	root, sub := d.getRootAndPath(path)
+	dsts, ok := d.pathMap[root]
+	if !ok {
+		return nil, errs.ObjectNotFound
+	}
+	var objs []model.Obj
+	for _, dst := range dsts {
+		tmp, err := d.list(ctx, dst, sub)
+		if err == nil {
+			objs = append(objs, tmp...)
+		}
+	}
+	return objs, nil
+}
+
+func (d *Alias) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*model.Link, error) {
+	root, sub := d.getRootAndPath(file.GetPath())
+	dsts, ok := d.pathMap[root]
+	if !ok {
+		return nil, errs.ObjectNotFound
+	}
+	for _, dst := range dsts {
+		link, err := d.link(ctx, dst, sub, args)
+		if err == nil {
+			return link, nil
+		}
+	}
+	return nil, errs.ObjectNotFound
+}
+
+var _ driver.Driver = (*Alias)(nil)

drivers/alias/meta.go

@@ -0,0 +1,27 @@
+package alias
+
+import (
+	"github.com/alist-org/alist/v3/internal/driver"
+	"github.com/alist-org/alist/v3/internal/op"
+)
+
+type Addition struct {
+	// Usually one of two
+	// driver.RootPath
+	// define other
+	Paths string `json:"paths" required:"true" type:"text"`
+}
+
+var config = driver.Config{
+	Name:        "Alias",
+	LocalSort:   true,
+	NoCache:     true,
+	NoUpload:    true,
+	DefaultRoot: "/",
+}
+
+func init() {
+	op.RegisterDriver(func() driver.Driver {
+		return &Alias{}
+	})
+}

drivers/alias/types.go

@@ -0,0 +1 @@
+package alias

drivers/alias/util.go

@@ -0,0 +1,103 @@
+package alias
+
+import (
+	"context"
+	"fmt"
+	stdpath "path"
+	"strings"
+
+	"github.com/alist-org/alist/v3/internal/fs"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/internal/sign"
+	"github.com/alist-org/alist/v3/pkg/utils"
+	"github.com/alist-org/alist/v3/server/common"
+)
+
+func (d *Alias) listRoot() []model.Obj {
+	var objs []model.Obj
+	for k, _ := range d.pathMap {
+		obj := model.Object{
+			Name:     k,
+			IsFolder: true,
+			Modified: d.Modified,
+		}
+		objs = append(objs, &obj)
+	}
+	return objs
+}
+
+// do others that not defined in Driver interface
+func getPair(path string) (string, string) {
+	//path = strings.TrimSpace(path)
+	if strings.Contains(path, ":") {
+		pair := strings.SplitN(path, ":", 2)
+		if !strings.Contains(pair[0], "/") {
+			return pair[0], pair[1]
+		}
+	}
+	return stdpath.Base(path), path
+}
+
+func (d *Alias) getRootAndPath(path string) (string, string) {
+	if d.autoFlatten {
+		return d.oneKey, path
+	}
+	path = strings.TrimPrefix(path, "/")
+	parts := strings.SplitN(path, "/", 2)
+	if len(parts) == 1 {
+		return parts[0], ""
+	}
+	return parts[0], parts[1]
+}
+
+func (d *Alias) get(ctx context.Context, path string, dst, sub string) (model.Obj, error) {
+	obj, err := fs.Get(ctx, stdpath.Join(dst, sub))
+	if err != nil {
+		return nil, err
+	}
+	return &model.Object{
+		Path:     path,
+		Name:     obj.GetName(),
+		Size:     obj.GetSize(),
+		Modified: obj.ModTime(),
+		IsFolder: obj.IsDir(),
+	}, nil
+}
+
+func (d *Alias) list(ctx context.Context, dst, sub string) ([]model.Obj, error) {
+	objs, err := fs.List(ctx, stdpath.Join(dst, sub))
+	// the obj must implement the model.SetPath interface
+	// return objs, err
+	if err != nil {
+		return nil, err
+	}
+	return utils.SliceConvert(objs, func(obj model.Obj) (model.Obj, error) {
+		return &model.Object{
+			Name:     obj.GetName(),
+			Size:     obj.GetSize(),
+			Modified: obj.ModTime(),
+			IsFolder: obj.IsDir(),
+		}, nil
+	})
+}
+
+func (d *Alias) link(ctx context.Context, dst, sub string, args model.LinkArgs) (*model.Link, error) {
+	reqPath := stdpath.Join(dst, sub)
+	storage, err := fs.GetStorage(reqPath)
+	if err != nil {
+		return nil, err
+	}
+	_, err = fs.Get(ctx, reqPath)
+	if err != nil {
+		return nil, err
+	}
+	if common.ShouldProxy(storage, stdpath.Base(sub)) {
+		return &model.Link{
+			URL: fmt.Sprintf("/p%s?sign=%s",
+				utils.EncodePath(reqPath, true),
+				sign.Sign(reqPath)),
+		}, nil
+	}
+	link, _, err := fs.Link(ctx, reqPath, args)
+	return link, err
+}

drivers/aliyundrive/driver.go

@@ -226,7 +226,7 @@ func (d *AliDrive) Put(ctx context.Context, dstDir model.Obj, stream model.FileS
 		delete(reqBody, "pre_hash")
 		h := sha1.New()
 		if localFile != nil {
-			if _, err = io.Copy(h, localFile); err != nil {
+			if err = utils.CopyWithCtx(ctx, h, localFile, 0, nil); err != nil {
 				return err
 			}
 			if _, err = localFile.Seek(0, io.SeekStart); err != nil {
@@ -241,7 +241,7 @@ func (d *AliDrive) Put(ctx context.Context, dstDir model.Obj, stream model.FileS
 				_ = tempFile.Close()
 				_ = os.Remove(tempFile.Name())
 			}()
-			if _, err = io.Copy(io.MultiWriter(tempFile, h), file); err != nil {
+			if err = utils.CopyWithCtx(ctx, io.MultiWriter(tempFile, h), file, 0, nil); err != nil {
 				return err
 			}
 			localFile = tempFile

drivers/aliyundrive_open/driver.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"math"
 	"net/http"
+	"strings"
 
 	"github.com/alist-org/alist/v3/drivers/base"
 	"github.com/alist-org/alist/v3/internal/driver"
@@ -170,7 +171,12 @@ func (d *AliyundriveOpen) Put(ctx context.Context, dstDir model.Obj, stream mode
 		if utils.IsCanceled(ctx) {
 			return ctx.Err()
 		}
-		req, err := http.NewRequest("PUT", partInfo.UploadUrl, io.LimitReader(stream, DEFAULT))
+		uploadUrl := partInfo.UploadUrl
+		if d.InternalUpload {
+			//Replace a known public Host with an internal Host
+			uploadUrl = strings.ReplaceAll(uploadUrl, "https://cn-beijing-data.aliyundrive.net/", "http://ccp-bj29-bj-1592982087.oss-cn-beijing-internal.aliyuncs.com/")
+		}
+		req, err := http.NewRequest("PUT", uploadUrl, io.LimitReader(stream, DEFAULT))
 		if err != nil {
 			return err
 		}

drivers/aliyundrive_open/meta.go

@@ -14,6 +14,7 @@ type Addition struct {
 	ClientID       string `json:"client_id" required:"false" help:"Keep it empty if you don't have one"`
 	ClientSecret   string `json:"client_secret" required:"false" help:"Keep it empty if you don't have one"`
 	RemoveWay      string `json:"remove_way" required:"true" type:"select" options:"trash,delete"`
+	InternalUpload bool   `json:"internal_upload" help:"If you are using Aliyun ECS in Beijing, you can turn it on to boost the upload speed"`
 }
 
 var config = driver.Config{

drivers/all.go

@@ -6,6 +6,7 @@ import (
 	_ "github.com/alist-org/alist/v3/drivers/139"
 	_ "github.com/alist-org/alist/v3/drivers/189"
 	_ "github.com/alist-org/alist/v3/drivers/189pc"
+	_ "github.com/alist-org/alist/v3/drivers/alias"
 	_ "github.com/alist-org/alist/v3/drivers/alist_v2"
 	_ "github.com/alist-org/alist/v3/drivers/alist_v3"
 	_ "github.com/alist-org/alist/v3/drivers/aliyundrive"
@@ -13,6 +14,7 @@ import (
 	_ "github.com/alist-org/alist/v3/drivers/aliyundrive_share"
 	_ "github.com/alist-org/alist/v3/drivers/baidu_netdisk"
 	_ "github.com/alist-org/alist/v3/drivers/baidu_photo"
+	_ "github.com/alist-org/alist/v3/drivers/baidu_share"
 	_ "github.com/alist-org/alist/v3/drivers/cloudreve"
 	_ "github.com/alist-org/alist/v3/drivers/ftp"
 	_ "github.com/alist-org/alist/v3/drivers/google_drive"
@@ -32,6 +34,7 @@ import (
 	_ "github.com/alist-org/alist/v3/drivers/teambition"
 	_ "github.com/alist-org/alist/v3/drivers/terabox"
 	_ "github.com/alist-org/alist/v3/drivers/thunder"
+	_ "github.com/alist-org/alist/v3/drivers/trainbit"
 	_ "github.com/alist-org/alist/v3/drivers/uss"
 	_ "github.com/alist-org/alist/v3/drivers/virtual"
 	_ "github.com/alist-org/alist/v3/drivers/webdav"

drivers/baidu_share/driver.go

@@ -0,0 +1,153 @@
+package baidu_share
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"time"
+
+	"github.com/Xhofe/go-cache"
+	"github.com/alist-org/alist/v3/drivers/base"
+	"github.com/alist-org/alist/v3/internal/driver"
+	"github.com/alist-org/alist/v3/internal/errs"
+	"github.com/alist-org/alist/v3/internal/model"
+)
+
+type BaiduShare struct {
+	model.Storage
+	Addition
+	config     map[string]string
+	dlinkCache cache.ICache[string]
+}
+
+func (d *BaiduShare) Config() driver.Config {
+	return config
+}
+
+func (d *BaiduShare) GetAddition() driver.Additional {
+	return &d.Addition
+}
+
+func (d *BaiduShare) Init(ctx context.Context) error {
+	// TODO login / refresh token
+	//op.MustSaveDriverStorage(d)
+	d.config = map[string]string{}
+	d.dlinkCache = cache.NewMemCache(cache.WithClearInterval[string](time.Duration(d.CacheExpiration) * time.Minute))
+	return nil
+}
+
+func (d *BaiduShare) Drop(ctx context.Context) error {
+	d.dlinkCache.Clear()
+	return nil
+}
+
+func (d *BaiduShare) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([]model.Obj, error) {
+	// TODO return the files list
+	body := url.Values{
+		"shorturl": {d.Surl},
+		"dir":      {dir.GetPath()},
+		"root":     {"0"},
+		"pwd":      {d.Pwd},
+		"num":      {"1000"},
+		"order":    {"time"},
+	}
+	if body.Get("dir") == "" || body.Get("dir") == d.config["root"] {
+		body.Set("root", "1")
+	}
+	res := []model.Obj{}
+	var err error
+	var page int64 = 1
+	more := true
+	for more {
+		body.Set("page", strconv.FormatInt(page, 10))
+		req := base.RestyClient.R().
+			SetCookies([]*http.Cookie{{Name: "BDUSS", Value: d.BDUSS}}).
+			SetBody(body.Encode())
+		resp, e := req.Post("https://pan.baidu.com/share/wxlist?channel=weixin&version=2.2.2&clienttype=25&web=1")
+		err = e
+		jsonresp := jsonResp{}
+		if err == nil {
+			err = base.RestyClient.JSONUnmarshal(resp.Body(), &jsonresp)
+		}
+		if err == nil && jsonresp.Errno == 0 {
+			more = jsonresp.Data.More
+			page += 1
+			for _, v := range jsonresp.Data.List {
+				size, _ := v.Size.Int64()
+				mtime, _ := v.Time.Int64()
+				res = append(res, &model.Object{
+					ID:       v.ID.String(),
+					Path:     v.Path,
+					Name:     v.Name,
+					Size:     size,
+					Modified: time.Unix(mtime, 0),
+					IsFolder: v.Dir.String() == "1",
+				})
+				d.dlinkCache.Set(v.Path, v.Dlink, cache.WithEx[string](time.Duration(d.CacheExpiration/2)*time.Minute))
+			}
+			if len(res) > 0 && body.Get("root") == "1" {
+				d.config["root"] = path.Dir(res[0].GetPath())
+			}
+		} else {
+			if err == nil {
+				err = fmt.Errorf("errno:%d", jsonresp.Errno)
+			}
+			break
+		}
+	}
+	return res, err
+}
+
+func (d *BaiduShare) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*model.Link, error) {
+	// TODO return link of file
+	var err error
+	req := base.RestyClient.R().SetCookies([]*http.Cookie{{Name: "BDUSS", Value: d.BDUSS}})
+	url, found := d.dlinkCache.Get(file.GetPath())
+	if !found {
+		_, err = d.List(ctx, &model.Object{Path: path.Dir(file.GetPath())}, model.ListArgs{})
+		url, found = d.dlinkCache.Get(file.GetPath())
+		if err == nil && !found {
+			err = errs.NotSupport
+		}
+	}
+	return &model.Link{URL: url, Header: req.Header}, err
+}
+
+func (d *BaiduShare) MakeDir(ctx context.Context, parentDir model.Obj, dirName string) error {
+	// TODO create folder
+	return errs.NotSupport
+}
+
+func (d *BaiduShare) Move(ctx context.Context, srcObj, dstDir model.Obj) error {
+	// TODO move obj
+	return errs.NotSupport
+}
+
+func (d *BaiduShare) Rename(ctx context.Context, srcObj model.Obj, newName string) error {
+	// TODO rename obj
+	return errs.NotSupport
+}
+
+func (d *BaiduShare) Copy(ctx context.Context, srcObj, dstDir model.Obj) error {
+	// TODO copy obj
+	return errs.NotSupport
+}
+
+func (d *BaiduShare) Remove(ctx context.Context, obj model.Obj) error {
+	// TODO remove obj
+	return errs.NotSupport
+}
+
+func (d *BaiduShare) Put(ctx context.Context, dstDir model.Obj, stream model.FileStreamer, up driver.UpdateProgress) error {
+	// TODO upload file
+	return errs.NotSupport
+}
+
+//func (d *Template) Other(ctx context.Context, args model.OtherArgs) (interface{}, error) {
+//	return nil, errs.NotSupport
+//}
+
+var _ driver.Driver = (*BaiduShare)(nil)

drivers/baidu_share/meta.go

@@ -0,0 +1,34 @@
+package baidu_share
+
+import (
+	"github.com/alist-org/alist/v3/internal/driver"
+	"github.com/alist-org/alist/v3/internal/op"
+)
+
+type Addition struct {
+	// Usually one of two
+	driver.RootPath
+	// driver.RootID
+	// define other
+	// Field string `json:"field" type:"select" required:"true" options:"a,b,c" default:"a"`
+	Surl  string `json:"surl"`
+	Pwd   string `json:"pwd"`
+	BDUSS string `json:"BDUSS"`
+}
+
+var config = driver.Config{
+	Name:        "BaiduShare",
+	LocalSort:   true,
+	OnlyLocal:   false,
+	OnlyProxy:   false,
+	NoCache:     false,
+	NoUpload:    true,
+	NeedMs:      false,
+	DefaultRoot: "",
+}
+
+func init() {
+	op.RegisterDriver(func() driver.Driver {
+		return &BaiduShare{}
+	})
+}

drivers/baidu_share/types.go

@@ -0,0 +1,19 @@
+package baidu_share
+
+import "encoding/json"
+
+type jsonResp struct {
+	Errno int64 `json:"errno"`
+	Data  struct {
+		More bool `json:"has_more"`
+		List []struct {
+			ID    json.Number `json:"fs_id"`
+			Dir   json.Number `json:"isdir"`
+			Path  string      `json:"path"`
+			Name  string      `json:"server_filename"`
+			Time  json.Number `json:"server_mtime"`
+			Size  json.Number `json:"size"`
+			Dlink string      `json:"dlink"`
+		} `json:"list"`
+	} `json:"data"`
+}

drivers/baidu_share/util.go

@@ -0,0 +1,3 @@
+package baidu_share
+
+// do others that not defined in Driver interface

drivers/ftp/driver.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	stdpath "path"
 
+	"github.com/alist-org/alist/v3/drivers/base"
 	"github.com/alist-org/alist/v3/internal/driver"
 	"github.com/alist-org/alist/v3/internal/errs"
 	"github.com/alist-org/alist/v3/internal/model"
@@ -44,8 +45,7 @@ func (d *FTP) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([]m
 		return nil, err
 	}
 	res := make([]model.Obj, 0)
-	for i, _ := range entries {
-		entry := entries[i]
+	for _, entry := range entries {
 		if entry.Name == "." || entry.Name == ".." {
 			continue
 		}
@@ -64,13 +64,13 @@ func (d *FTP) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*m
 	if err := d.login(); err != nil {
 		return nil, err
 	}
-	resp, err := d.conn.Retr(file.GetPath())
-	if err != nil {
-		return nil, err
+
+	r := NewFTPFileReader(d.conn, file.GetPath())
+	link := &model.Link{
+		Data: r,
 	}
-	return &model.Link{
-		Data: resp,
-	}, nil
+	base.HandleRange(link, r, args.Header, file.GetSize())
+	return link, nil
 }
 
 func (d *FTP) MakeDir(ctx context.Context, parentDir model.Obj, dirName string) error {

drivers/ftp/util.go

@@ -1,6 +1,13 @@
 package ftp
 
-import "github.com/jlaffaye/ftp"
+import (
+	"io"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/jlaffaye/ftp"
+)
 
 // do others that not defined in Driver interface
 
@@ -11,7 +18,7 @@ func (d *FTP) login() error {
 			return nil
 		}
 	}
-	conn, err := ftp.Dial(d.Address)
+	conn, err := ftp.Dial(d.Address, ftp.DialWithShutTimeout(10*time.Second))
 	if err != nil {
 		return err
 	}
@@ -22,3 +29,81 @@ func (d *FTP) login() error {
 	d.conn = conn
 	return nil
 }
+
+// An FTP file reader that implements io.ReadSeekCloser for seeking.
+type FTPFileReader struct {
+	conn   *ftp.ServerConn
+	resp   *ftp.Response
+	offset int64
+	mu     sync.Mutex
+	path   string
+}
+
+func NewFTPFileReader(conn *ftp.ServerConn, path string) *FTPFileReader {
+	return &FTPFileReader{
+		conn: conn,
+		path: path,
+	}
+}
+
+func (r *FTPFileReader) Read(buf []byte) (n int, err error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if r.resp == nil {
+		r.resp, err = r.conn.RetrFrom(r.path, uint64(r.offset))
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	n, err = r.resp.Read(buf)
+	r.offset += int64(n)
+	return
+}
+
+func (r *FTPFileReader) Seek(offset int64, whence int) (int64, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	oldOffset := r.offset
+	var newOffset int64
+	switch whence {
+	case io.SeekStart:
+		newOffset = offset
+	case io.SeekCurrent:
+		newOffset = oldOffset + offset
+	case io.SeekEnd:
+		size, err := r.conn.FileSize(r.path)
+		if err != nil {
+			return oldOffset, err
+		}
+		newOffset = offset + int64(size)
+	default:
+		return -1, os.ErrInvalid
+	}
+
+	if newOffset < 0 {
+		// offset out of range
+		return oldOffset, os.ErrInvalid
+	}
+	if newOffset == oldOffset {
+		// offset not changed, so return directly
+		return oldOffset, nil
+	}
+	r.offset = newOffset
+
+	if r.resp != nil {
+		// close the existing ftp data connection, otherwise the next read will be blocked
+		_ = r.resp.Close() // we do not care about whether it returns an error
+		r.resp = nil
+	}
+	return newOffset, nil
+}
+
+func (r *FTPFileReader) Close() error {
+	if r.resp != nil {
+		return r.resp.Close()
+	}
+	return nil
+}