modules/lfstransfer: add a backend and runner

Also add handler in runServ()

The protocol lib supports locking but the backend does not,
as neither does Gitea. Support can be added later and the
capability advertised.

cmd/serv.go

@@ -22,6 +22,7 @@ import (
 	"code.gitea.io/gitea/models/perm"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/json"
+	"code.gitea.io/gitea/modules/lfstransfer"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/pprof"
 	"code.gitea.io/gitea/modules/private"
@@ -40,6 +41,7 @@ const (
 	verbUploadArchive   = "git-upload-archive"
 	verbReceivePack     = "git-receive-pack"
 	verbLfsAuthenticate = "git-lfs-authenticate"
+	verbLfsTransfer     = "git-lfs-transfer"
 )
 
 // CmdServ represents the available serv sub-command.
@@ -83,9 +85,11 @@ var (
 		verbUploadArchive:   true,
 		verbReceivePack:     true,
 		verbLfsAuthenticate: true,
+		verbLfsTransfer:     true,
 	}
 	allowedCommandsLfs = map[string]bool{
 		verbLfsAuthenticate: true,
+		verbLfsTransfer:     true,
 	}
 	alphaDashDotPattern = regexp.MustCompile(`[^\w-\.]`)
 )
@@ -138,7 +142,7 @@ func getAccessMode(verb string, lfsVerb string) perm.AccessMode {
 		return perm.AccessModeRead
 	case verbReceivePack:
 		return perm.AccessModeWrite
-	case verbLfsAuthenticate:
+	case verbLfsAuthenticate, verbLfsTransfer:
 		switch lfsVerb {
 		case "upload":
 			return perm.AccessModeWrite
@@ -297,6 +301,15 @@ func runServ(c *cli.Context) error {
 		return fail(ctx, extra.UserMsg, "ServCommand failed: %s", extra.Error)
 	}
 
+	// LFS SSH protocol
+	if verb == verbLfsTransfer {
+		token, err := getLFSAuthToken(ctx, lfsVerb, results)
+		if err != nil {
+			return err
+		}
+		return lfstransfer.Main(ctx, repoPath, lfsVerb, token)
+	}
+
 	// LFS token authentication
 	if verb == verbLfsAuthenticate {
 		url := fmt.Sprintf("%s%s/%s.git/info/lfs", setting.AppURL, url.PathEscape(results.OwnerName), url.PathEscape(results.RepoName))