From 2278a30f91da38e20065123efbba8ffdcd540b3b Mon Sep 17 00:00:00 2001
From: Saw-jan <saw.jan.grg3e@gmail.com>
Date: Wed, 10 Jan 2024 16:54:33 +0545
Subject: [PATCH] raise Exception if the provider is not webdav when using
 proxy mode

---
 cmd/serve/s3/backend.go |  2 +-
 cmd/serve/s3/s3.go      | 11 +++++++++--
 cmd/serve/s3/server.go  |  2 +-
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/cmd/serve/s3/backend.go b/cmd/serve/s3/backend.go
index c6066080e6a4b..1182d571e817c 100644
--- a/cmd/serve/s3/backend.go
+++ b/cmd/serve/s3/backend.go
@@ -41,7 +41,7 @@ func newBackend(opt *Options, w *Server) gofakes3.Backend {
 }
 
 func (b *s3Backend) getVfs(accessKey string) *vfs.VFS {
-	if b.opt.asProxy {
+	if b.opt.proxyMode {
 		// new VFS
 		if _, ok := b.w.f.(*webdav.Fs); ok {
 			info, name, remote, config, _ := fs.ConfigFs(b.w.f.Name() + ":")
diff --git a/cmd/serve/s3/s3.go b/cmd/serve/s3/s3.go
index 293843f501593..57083fa0fa2e1 100644
--- a/cmd/serve/s3/s3.go
+++ b/cmd/serve/s3/s3.go
@@ -4,7 +4,9 @@ import (
 	"context"
 	_ "embed"
 
+	"github.com/rclone/rclone/backend/webdav"
 	"github.com/rclone/rclone/cmd"
+	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/config/flags"
 	"github.com/rclone/rclone/fs/hash"
 	httplib "github.com/rclone/rclone/lib/http"
@@ -19,7 +21,7 @@ var DefaultOpt = Options{
 	hashName:       "MD5",
 	hashType:       hash.MD5,
 	noCleanup:      false,
-	asProxy:        false,
+	proxyMode:      false,
 	HTTP:           httplib.DefaultCfg(),
 }
 
@@ -36,7 +38,7 @@ func init() {
 	flags.StringVarP(flagSet, &Opt.hashName, "etag-hash", "", Opt.hashName, "Which hash to use for the ETag, or auto or blank for off", "")
 	flags.StringArrayVarP(flagSet, &Opt.authPair, "auth-key", "", Opt.authPair, "Set key pair for v4 authorization: access_key_id,secret_access_key", "")
 	flags.BoolVarP(flagSet, &Opt.noCleanup, "no-cleanup", "", Opt.noCleanup, "Not to cleanup empty folder after object is deleted", "")
-	flags.BoolVarP(flagSet, &Opt.asProxy, "as-proxy", "", Opt.asProxy, "Serve as a proxy", "")
+	flags.BoolVarP(flagSet, &Opt.proxyMode, "proxy-mode", "", Opt.proxyMode, "Serve as a proxy for s3 clients", "")
 }
 
 //go:embed serve_s3.md
@@ -56,6 +58,11 @@ var Command = &cobra.Command{
 		cmd.CheckArgs(1, 1, command, args)
 		f := cmd.NewFsSrc(args)
 
+		if _, ok := f.(*webdav.Fs); !ok && Opt.proxyMode {
+			fs.Logf("serve s3", "Proxy mode is not supported for %s provider", f.Name())
+			return fs.ErrorNotImplemented
+		}
+
 		if Opt.hashName == "auto" {
 			Opt.hashType = f.Hashes().GetOne()
 		} else if Opt.hashName != "" {
diff --git a/cmd/serve/s3/server.go b/cmd/serve/s3/server.go
index ec4584ec34334..efb399835c0fb 100644
--- a/cmd/serve/s3/server.go
+++ b/cmd/serve/s3/server.go
@@ -24,7 +24,7 @@ type Options struct {
 	hashType       hash.Type
 	authPair       []string
 	noCleanup      bool
-	asProxy        bool
+	proxyMode      bool
 	HTTP           httplib.Config
 }