sftpgo-mirror/common/actions.go
Nicola Murino 25a44030f9
actions: add pre-download and pre-upload
Downloads and uploads can be denied based on hook response
2021-05-26 07:48:37 +02:00

234 lines
7.8 KiB
Go

package common
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"os"
"os/exec"
"path/filepath"
"strings"
"time"
"github.com/drakkan/sftpgo/dataprovider"
"github.com/drakkan/sftpgo/httpclient"
"github.com/drakkan/sftpgo/logger"
"github.com/drakkan/sftpgo/utils"
"github.com/drakkan/sftpgo/vfs"
)
var (
errUnconfiguredAction = errors.New("no hook is configured for this action")
errNoHook = errors.New("unable to execute action, no hook defined")
errUnexpectedHTTResponse = errors.New("unexpected HTTP response code")
)
// ProtocolActions defines the action to execute on file operations and SSH commands
type ProtocolActions struct {
// Valid values are download, upload, pre-delete, delete, rename, ssh_cmd. Empty slice to disable
ExecuteOn []string `json:"execute_on" mapstructure:"execute_on"`
// Actions to be performed synchronously.
// The pre-delete action is always executed synchronously while the other ones are asynchronous.
// Executing an action synchronously means that SFTPGo will not return a result code to the client
// (which is waiting for it) until your hook have completed its execution.
ExecuteSync []string `json:"execute_sync" mapstructure:"execute_sync"`
// Absolute path to an external program or an HTTP URL
Hook string `json:"hook" mapstructure:"hook"`
}
var actionHandler ActionHandler = &defaultActionHandler{}
// InitializeActionHandler lets the user choose an action handler implementation.
//
// Do NOT call this function after application initialization.
func InitializeActionHandler(handler ActionHandler) {
actionHandler = handler
}
// ExecutePreAction executes a pre-* action and returns the result
func ExecutePreAction(user *dataprovider.User, operation, filePath, virtualPath, protocol string, fileSize int64) error {
if !utils.IsStringInSlice(operation, Config.Actions.ExecuteOn) {
// for pre-delete we execute the internal handling on error, so we must return errUnconfiguredAction.
// Other pre action will deny the operation on error so if we have no configuration we must return
// a nil error
if operation == operationPreDelete {
return errUnconfiguredAction
}
return nil
}
notification := newActionNotification(user, operation, filePath, virtualPath, "", "", protocol, fileSize, nil)
return actionHandler.Handle(notification)
}
// ExecuteActionNotification executes the defined hook, if any, for the specified action
func ExecuteActionNotification(user *dataprovider.User, operation, filePath, virtualPath, target, sshCmd, protocol string, fileSize int64, err error) {
notification := newActionNotification(user, operation, filePath, virtualPath, target, sshCmd, protocol, fileSize, err)
if utils.IsStringInSlice(operation, Config.Actions.ExecuteSync) {
actionHandler.Handle(notification) //nolint:errcheck
return
}
go actionHandler.Handle(notification) //nolint:errcheck
}
// ActionHandler handles a notification for a Protocol Action.
type ActionHandler interface {
Handle(notification *ActionNotification) error
}
// ActionNotification defines a notification for a Protocol Action.
type ActionNotification struct {
Action string `json:"action"`
Username string `json:"username"`
Path string `json:"path"`
TargetPath string `json:"target_path,omitempty"`
SSHCmd string `json:"ssh_cmd,omitempty"`
FileSize int64 `json:"file_size,omitempty"`
FsProvider int `json:"fs_provider"`
Bucket string `json:"bucket,omitempty"`
Endpoint string `json:"endpoint,omitempty"`
Status int `json:"status"`
Protocol string `json:"protocol"`
}
func newActionNotification(
user *dataprovider.User,
operation, filePath, virtualPath, target, sshCmd, protocol string,
fileSize int64,
err error,
) *ActionNotification {
var bucket, endpoint string
status := 1
fsConfig := user.GetFsConfigForPath(virtualPath)
switch fsConfig.Provider {
case vfs.S3FilesystemProvider:
bucket = fsConfig.S3Config.Bucket
endpoint = fsConfig.S3Config.Endpoint
case vfs.GCSFilesystemProvider:
bucket = fsConfig.GCSConfig.Bucket
case vfs.AzureBlobFilesystemProvider:
bucket = fsConfig.AzBlobConfig.Container
if fsConfig.AzBlobConfig.SASURL != "" {
endpoint = fsConfig.AzBlobConfig.SASURL
} else {
endpoint = fsConfig.AzBlobConfig.Endpoint
}
case vfs.SFTPFilesystemProvider:
endpoint = fsConfig.SFTPConfig.Endpoint
}
if err == ErrQuotaExceeded {
status = 2
} else if err != nil {
status = 0
}
return &ActionNotification{
Action: operation,
Username: user.Username,
Path: filePath,
TargetPath: target,
SSHCmd: sshCmd,
FileSize: fileSize,
FsProvider: int(fsConfig.Provider),
Bucket: bucket,
Endpoint: endpoint,
Status: status,
Protocol: protocol,
}
}
type defaultActionHandler struct{}
func (h *defaultActionHandler) Handle(notification *ActionNotification) error {
if !utils.IsStringInSlice(notification.Action, Config.Actions.ExecuteOn) {
return errUnconfiguredAction
}
if Config.Actions.Hook == "" {
logger.Warn(notification.Protocol, "", "Unable to send notification, no hook is defined")
return errNoHook
}
if strings.HasPrefix(Config.Actions.Hook, "http") {
return h.handleHTTP(notification)
}
return h.handleCommand(notification)
}
func (h *defaultActionHandler) handleHTTP(notification *ActionNotification) error {
u, err := url.Parse(Config.Actions.Hook)
if err != nil {
logger.Warn(notification.Protocol, "", "Invalid hook %#v for operation %#v: %v", Config.Actions.Hook, notification.Action, err)
return err
}
startTime := time.Now()
respCode := 0
var b bytes.Buffer
_ = json.NewEncoder(&b).Encode(notification)
resp, err := httpclient.RetryablePost(Config.Actions.Hook, "application/json", &b)
if err == nil {
respCode = resp.StatusCode
resp.Body.Close()
if respCode != http.StatusOK {
err = errUnexpectedHTTResponse
}
}
logger.Debug(notification.Protocol, "", "notified operation %#v to URL: %v status code: %v, elapsed: %v err: %v",
notification.Action, u.Redacted(), respCode, time.Since(startTime), err)
return err
}
func (h *defaultActionHandler) handleCommand(notification *ActionNotification) error {
if !filepath.IsAbs(Config.Actions.Hook) {
err := fmt.Errorf("invalid notification command %#v", Config.Actions.Hook)
logger.Warn(notification.Protocol, "", "unable to execute notification command: %v", err)
return err
}
ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()
cmd := exec.CommandContext(ctx, Config.Actions.Hook, notification.Action, notification.Username, notification.Path, notification.TargetPath, notification.SSHCmd)
cmd.Env = append(os.Environ(), notificationAsEnvVars(notification)...)
startTime := time.Now()
err := cmd.Run()
logger.Debug(notification.Protocol, "", "executed command %#v with arguments: %#v, %#v, %#v, %#v, %#v, elapsed: %v, error: %v",
Config.Actions.Hook, notification.Action, notification.Username, notification.Path, notification.TargetPath, notification.SSHCmd, time.Since(startTime), err)
return err
}
func notificationAsEnvVars(notification *ActionNotification) []string {
return []string{
fmt.Sprintf("SFTPGO_ACTION=%v", notification.Action),
fmt.Sprintf("SFTPGO_ACTION_USERNAME=%v", notification.Username),
fmt.Sprintf("SFTPGO_ACTION_PATH=%v", notification.Path),
fmt.Sprintf("SFTPGO_ACTION_TARGET=%v", notification.TargetPath),
fmt.Sprintf("SFTPGO_ACTION_SSH_CMD=%v", notification.SSHCmd),
fmt.Sprintf("SFTPGO_ACTION_FILE_SIZE=%v", notification.FileSize),
fmt.Sprintf("SFTPGO_ACTION_FS_PROVIDER=%v", notification.FsProvider),
fmt.Sprintf("SFTPGO_ACTION_BUCKET=%v", notification.Bucket),
fmt.Sprintf("SFTPGO_ACTION_ENDPOINT=%v", notification.Endpoint),
fmt.Sprintf("SFTPGO_ACTION_STATUS=%v", notification.Status),
fmt.Sprintf("SFTPGO_ACTION_PROTOCOL=%v", notification.Protocol),
}
}