add --sftp-chattr

copyparty/__main__.py

@@ -1700,6 +1700,7 @@ def add_sftp(ap):
     ap2.add_argument("--sftp-anon", metavar="TXT", type=u, default="", help="allow anonymous/unauthenticated connections with \033[33mTXT\033[0m as username")
     ap2.add_argument("--sftp-hostk", metavar="FP", type=u, default=E.cfg, help="path to folder with hostkeys, for example 'ssh_host_rsa_key'; missing keys will be generated")
     ap2.add_argument("--sftp-fastldr", action="store_true", help="speedhack for 'loading hostkeys' on old CPUs; only use with known-good hostkeys")
+    ap2.add_argument("--sftp-chattr", metavar="T", default="s", help="which attributes can be modified with chattr? [\033[32ms\033[0m]=size, [\033[32mt\033[0m]=mtime, [\033[32mp\033[0m]=permissions, [\033[32mu\033[0m]=uid/gid. Example: [\033[32mstpu\033[0m]")
     ap2.add_argument("--sftp-banner", metavar="T", type=u, default="", help="bannertext to send when someone connects; can be @filepath")
     ap2.add_argument("--sftp-ipa", metavar="CIDR", type=u, default="", help="only accept connections from IP-addresses inside \033[33mCIDR\033[0m (comma-separated); specify [\033[32many\033[0m] to disable inheriting \033[33m--ipa\033[0m / \033[33m--ipar\033[0m. Examples: [\033[32mlan\033[0m] or [\033[32m10.89.0.0/16, 192.168.33.0/24\033[0m]")
     ap2.add_argument("--sftp-hs-t", metavar="SEC", type=int, default=15, help="connection handshake timeout in seconds")

copyparty/sftpd.py

@@ -311,6 +311,17 @@ class SFTP_Srv(paramiko.SFTPServerInterface):
         if self.uname == LEELOO_DALLAS:
             raise Exception("send her back")
 
+        cm = 0
+        for zs, zi in (
+            ("s", SATTR.FLAG_SIZE),
+            ("t", SATTR.FLAG_AMTIME),
+            ("p", SATTR.FLAG_PERMISSIONS),
+            ("u", SATTR.FLAG_UIDGID),
+        ):
+            if zs in self.args.sftp_chattr:
+                cm |= zi
+        self.chattr_mask = cm
+
         self.vols = [
             vp
             for vp, vn in self.asrv.vfs.all_vols.items()
@@ -735,6 +746,7 @@ class SFTP_Srv(paramiko.SFTPServerInterface):
     def _chattr(self, vp: str, attr: SATTR) -> int:
         self.log("chattr(%s, %s)" % (vp, attr))
         try:
+            attr._flags &= self.chattr_mask
             ap, _, _ = self.v2a(vp, w=True, d=True)
             paramiko.SFTPServer.set_file_attr(ap, attr)
             return SFTP_OK