minio/cmd/sftp-server-driver.go
Harshavardhana 1d3bd02089
avoid close 'nil' panics if any (#18890)
brings a generic implementation that
prints a stack trace for 'nil' channel
closes(), if not safely closes it.
2024-01-28 10:04:17 -08:00

535 lines
13 KiB
Go

// Copyright (c) 2015-2023 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"os"
"strings"
"sync"
"time"
"github.com/minio/madmin-go/v3"
"github.com/minio/minio-go/v7"
"github.com/minio/minio-go/v7/pkg/credentials"
"github.com/minio/minio/internal/auth"
xioutil "github.com/minio/minio/internal/ioutil"
"github.com/minio/minio/internal/logger"
"github.com/pkg/sftp"
"golang.org/x/crypto/ssh"
)
type sftpDriver struct {
permissions *ssh.Permissions
endpoint string
}
//msgp:ignore sftpMetrics
type sftpMetrics struct{}
var globalSftpMetrics sftpMetrics
func sftpTrace(s *sftp.Request, startTime time.Time, source string, user string, err error) madmin.TraceInfo {
var errStr string
if err != nil {
errStr = err.Error()
}
return madmin.TraceInfo{
TraceType: madmin.TraceFTP,
Time: startTime,
NodeName: globalLocalNodeName,
FuncName: fmt.Sprintf("sftp USER=%s COMMAND=%s PARAM=%s, Source=%s", user, s.Method, s.Filepath, source),
Duration: time.Since(startTime),
Path: s.Filepath,
Error: errStr,
}
}
func (m *sftpMetrics) log(s *sftp.Request, user string) func(err error) {
startTime := time.Now()
source := getSource(2)
return func(err error) {
globalTrace.Publish(sftpTrace(s, startTime, source, user, err))
}
}
// NewSFTPDriver initializes sftp.Handlers implementation of following interfaces
//
// - sftp.Fileread
// - sftp.Filewrite
// - sftp.Filelist
// - sftp.Filecmd
func NewSFTPDriver(perms *ssh.Permissions) sftp.Handlers {
handler := &sftpDriver{endpoint: fmt.Sprintf("127.0.0.1:%s", globalMinioPort), permissions: perms}
return sftp.Handlers{
FileGet: handler,
FilePut: handler,
FileCmd: handler,
FileList: handler,
}
}
func (f *sftpDriver) getMinIOClient() (*minio.Client, error) {
ui, ok := globalIAMSys.GetUser(context.Background(), f.AccessKey())
if !ok && !globalIAMSys.LDAPConfig.Enabled() {
return nil, errNoSuchUser
}
if !ok && globalIAMSys.LDAPConfig.Enabled() {
sa, _, err := globalIAMSys.getServiceAccount(context.Background(), f.AccessKey())
if err != nil && !errors.Is(err, errNoSuchServiceAccount) {
return nil, err
}
var mcreds *credentials.Credentials
if errors.Is(err, errNoSuchServiceAccount) {
targetUser, targetGroups, err := globalIAMSys.LDAPConfig.LookupUserDN(f.AccessKey())
if err != nil {
return nil, err
}
expiryDur, err := globalIAMSys.LDAPConfig.GetExpiryDuration("")
if err != nil {
return nil, err
}
claims := make(map[string]interface{})
claims[expClaim] = UTCNow().Add(expiryDur).Unix()
for k, v := range f.permissions.CriticalOptions {
claims[k] = v
}
cred, err := auth.GetNewCredentialsWithMetadata(claims, globalActiveCred.SecretKey)
if err != nil {
return nil, err
}
// Set the parent of the temporary access key, this is useful
// in obtaining service accounts by this cred.
cred.ParentUser = targetUser
// Set this value to LDAP groups, LDAP user can be part
// of large number of groups
cred.Groups = targetGroups
// Set the newly generated credentials, policyName is empty on purpose
// LDAP policies are applied automatically using their ldapUser, ldapGroups
// mapping.
updatedAt, err := globalIAMSys.SetTempUser(context.Background(), cred.AccessKey, cred, "")
if err != nil {
return nil, err
}
// Call hook for site replication.
logger.LogIf(context.Background(), globalSiteReplicationSys.IAMChangeHook(context.Background(), madmin.SRIAMItem{
Type: madmin.SRIAMItemSTSAcc,
STSCredential: &madmin.SRSTSCredential{
AccessKey: cred.AccessKey,
SecretKey: cred.SecretKey,
SessionToken: cred.SessionToken,
ParentUser: cred.ParentUser,
},
UpdatedAt: updatedAt,
}))
mcreds = credentials.NewStaticV4(cred.AccessKey, cred.SecretKey, cred.SessionToken)
} else {
mcreds = credentials.NewStaticV4(sa.Credentials.AccessKey, sa.Credentials.SecretKey, "")
}
return minio.New(f.endpoint, &minio.Options{
Creds: mcreds,
Secure: globalIsTLS,
Transport: globalRemoteFTPClientTransport,
})
}
// ok == true - at this point
if ui.Credentials.IsTemp() {
// Temporary credentials are not allowed.
return nil, errAuthentication
}
return minio.New(f.endpoint, &minio.Options{
Creds: credentials.NewStaticV4(ui.Credentials.AccessKey, ui.Credentials.SecretKey, ""),
Secure: globalIsTLS,
Transport: globalRemoteFTPClientTransport,
})
}
func (f *sftpDriver) AccessKey() string {
if _, ok := f.permissions.CriticalOptions["accessKey"]; !ok {
return f.permissions.CriticalOptions[ldapUserN]
}
return f.permissions.CriticalOptions["accessKey"]
}
func (f *sftpDriver) Fileread(r *sftp.Request) (ra io.ReaderAt, err error) {
stopFn := globalSftpMetrics.log(r, f.AccessKey())
defer stopFn(err)
flags := r.Pflags()
if !flags.Read {
// sanity check
return nil, os.ErrInvalid
}
bucket, object := path2BucketObject(r.Filepath)
if bucket == "" {
return nil, errors.New("bucket name cannot be empty")
}
clnt, err := f.getMinIOClient()
if err != nil {
return nil, err
}
obj, err := clnt.GetObject(context.Background(), bucket, object, minio.GetObjectOptions{})
if err != nil {
return nil, err
}
_, err = obj.Stat()
if err != nil {
return nil, err
}
return obj, nil
}
// TransferError will catch network errors during transfer.
// When TransferError() is called Close() will also
// be called, so we do not need to Wait() here.
func (w *writerAt) TransferError(err error) {
_ = w.w.CloseWithError(err)
_ = w.r.CloseWithError(err)
w.err = err
}
func (w *writerAt) Close() (err error) {
switch {
case len(w.buffer) > 0:
err = errors.New("some file segments were not flushed from the queue")
_ = w.w.CloseWithError(err)
case w.err != nil:
// No need to close here since both pipes were
// closing inside TransferError()
err = w.err
default:
err = w.w.Close()
}
for i := range w.buffer {
delete(w.buffer, i)
}
w.wg.Wait()
return err
}
type writerAt struct {
w *io.PipeWriter
r *io.PipeReader
wg *sync.WaitGroup
buffer map[int64][]byte
err error
nextOffset int64
m sync.Mutex
}
func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
w.m.Lock()
defer w.m.Unlock()
if w.nextOffset == offset {
n, err = w.w.Write(b)
w.nextOffset += int64(n)
} else {
w.buffer[offset] = make([]byte, len(b))
copy(w.buffer[offset], b)
n = len(b)
}
again:
nextOut, ok := w.buffer[w.nextOffset]
if ok {
n, err = w.w.Write(nextOut)
delete(w.buffer, w.nextOffset)
w.nextOffset += int64(n)
if n != len(nextOut) {
return 0, fmt.Errorf("expected write size %d but wrote %d bytes", len(nextOut), n)
}
if err != nil {
return 0, err
}
goto again
}
return len(b), nil
}
func (f *sftpDriver) Filewrite(r *sftp.Request) (w io.WriterAt, err error) {
stopFn := globalSftpMetrics.log(r, f.AccessKey())
defer stopFn(err)
flags := r.Pflags()
if !flags.Write {
// sanity check
return nil, os.ErrInvalid
}
bucket, object := path2BucketObject(r.Filepath)
if bucket == "" {
return nil, errors.New("bucket name cannot be empty")
}
clnt, err := f.getMinIOClient()
if err != nil {
return nil, err
}
ok, err := clnt.BucketExists(r.Context(), bucket)
if err != nil {
return nil, err
}
if !ok {
return nil, os.ErrNotExist
}
pr, pw := io.Pipe()
wa := &writerAt{
buffer: make(map[int64][]byte),
w: pw,
r: pr,
wg: &sync.WaitGroup{},
}
wa.wg.Add(1)
go func() {
_, err := clnt.PutObject(r.Context(), bucket, object, pr, -1, minio.PutObjectOptions{SendContentMd5: true})
pr.CloseWithError(err)
wa.wg.Done()
}()
return wa, nil
}
func (f *sftpDriver) Filecmd(r *sftp.Request) (err error) {
stopFn := globalSftpMetrics.log(r, f.AccessKey())
defer stopFn(err)
clnt, err := f.getMinIOClient()
if err != nil {
return err
}
switch r.Method {
case "Setstat", "Rename", "Link", "Symlink":
return NotImplemented{}
case "Rmdir":
bucket, prefix := path2BucketObject(r.Filepath)
if bucket == "" {
return errors.New("deleting all buckets not allowed")
}
cctx, cancel := context.WithCancel(context.Background())
defer cancel()
if prefix == "" {
// if all objects are not deleted yet this call may fail.
return clnt.RemoveBucket(cctx, bucket)
}
objectsCh := make(chan minio.ObjectInfo)
// Send object names that are needed to be removed to objectsCh
go func() {
defer xioutil.SafeClose(objectsCh)
opts := minio.ListObjectsOptions{
Prefix: prefix,
Recursive: true,
}
for object := range clnt.ListObjects(cctx, bucket, opts) {
if object.Err != nil {
return
}
objectsCh <- object
}
}()
// Call RemoveObjects API
for err := range clnt.RemoveObjects(context.Background(), bucket, objectsCh, minio.RemoveObjectsOptions{}) {
if err.Err != nil {
return err.Err
}
}
return err
case "Remove":
bucket, object := path2BucketObject(r.Filepath)
if bucket == "" {
return errors.New("bucket name cannot be empty")
}
return clnt.RemoveObject(context.Background(), bucket, object, minio.RemoveObjectOptions{})
case "Mkdir":
bucket, prefix := path2BucketObject(r.Filepath)
if bucket == "" {
return errors.New("bucket name cannot be empty")
}
if prefix == "" {
return clnt.MakeBucket(context.Background(), bucket, minio.MakeBucketOptions{Region: globalSite.Region})
}
dirPath := buildMinioDir(prefix)
_, err = clnt.PutObject(context.Background(), bucket, dirPath, bytes.NewReader([]byte("")), 0,
// Always send Content-MD5 to succeed with bucket with
// locking enabled. There is no performance hit since
// this is always an empty object
minio.PutObjectOptions{SendContentMd5: true},
)
return err
}
return NotImplemented{}
}
type listerAt []os.FileInfo
// Modeled after strings.Reader's ReadAt() implementation
func (f listerAt) ListAt(ls []os.FileInfo, offset int64) (int, error) {
var n int
if offset >= int64(len(f)) {
return 0, io.EOF
}
n = copy(ls, f[offset:])
if n < len(ls) {
return n, io.EOF
}
return n, nil
}
func (f *sftpDriver) Filelist(r *sftp.Request) (la sftp.ListerAt, err error) {
stopFn := globalSftpMetrics.log(r, f.AccessKey())
defer stopFn(err)
clnt, err := f.getMinIOClient()
if err != nil {
return nil, err
}
switch r.Method {
case "List":
var files []os.FileInfo
bucket, prefix := path2BucketObject(r.Filepath)
if bucket == "" {
buckets, err := clnt.ListBuckets(r.Context())
if err != nil {
return nil, err
}
for _, bucket := range buckets {
files = append(files, &minioFileInfo{
p: bucket.Name,
info: minio.ObjectInfo{Key: bucket.Name, LastModified: bucket.CreationDate},
isDir: true,
})
}
return listerAt(files), nil
}
prefix = retainSlash(prefix)
for object := range clnt.ListObjects(r.Context(), bucket, minio.ListObjectsOptions{
Prefix: prefix,
Recursive: false,
}) {
if object.Err != nil {
return nil, object.Err
}
if object.Key == prefix {
continue
}
isDir := strings.HasSuffix(object.Key, SlashSeparator)
files = append(files, &minioFileInfo{
p: pathClean(strings.TrimPrefix(object.Key, prefix)),
info: object,
isDir: isDir,
})
}
return listerAt(files), nil
case "Stat":
if r.Filepath == SlashSeparator {
return listerAt{&minioFileInfo{
p: r.Filepath,
isDir: true,
}}, nil
}
bucket, object := path2BucketObject(r.Filepath)
if bucket == "" {
return nil, errors.New("bucket name cannot be empty")
}
if object == "" {
ok, err := clnt.BucketExists(context.Background(), bucket)
if err != nil {
return nil, err
}
if !ok {
return nil, os.ErrNotExist
}
return listerAt{&minioFileInfo{
p: pathClean(bucket),
info: minio.ObjectInfo{Key: bucket},
isDir: true,
}}, nil
}
objInfo, err := clnt.StatObject(context.Background(), bucket, object, minio.StatObjectOptions{})
if err != nil {
if minio.ToErrorResponse(err).Code == "NoSuchKey" {
// dummy return to satisfy LIST (stat -> list) behavior.
return listerAt{&minioFileInfo{
p: pathClean(object),
info: minio.ObjectInfo{Key: object},
isDir: true,
}}, nil
}
return nil, err
}
isDir := strings.HasSuffix(objInfo.Key, SlashSeparator)
return listerAt{&minioFileInfo{
p: pathClean(object),
info: objInfo,
isDir: isDir,
}}, nil
}
return nil, NotImplemented{}
}