Begin to add groupmap logic

src/middlewared/middlewared/utils/groupmap.py

@@ -0,0 +1,33 @@
+from base64 import b64decode, b64encode
+from collections import namedtuple
+
+from middlewared.utils.sid import (
+        lsa_sidtype
+)
+from socket import htonl, ntohl
+
+UNIX_GROUP_KEY_PREFIX = 'UNIXGROUP/'
+MEMBEROF_PREFIX = 'MEMBEROF/'
+
+GROUP_MAP = namedtuple('SMBGroupMap', ['gid', 'sid_type', 'name', 'comment'])
+GROUPMEM = namedtuple('SMBGroupMembership', ['sid', 'members'])
+
+def _parse_unixgroup(tdb_key: str, tdb_val: str) -> GROUP_MAP:
+    sid = tdb_key[len(UNIX_GROUP_KEY_PREFIX):]
+    data = b64decode(tdb_val)
+
+    # unix groups are written into tdb file via tdb_pack
+    gid = htonl(data[0:4])
+    sid_type = lsa_sidtype(htonl(data[4:8]))
+
+    # remaining bytes are two null-terminated strings
+    bname, bcomment = data[8:-1].split(b'\x00')
+    return GROUP_MAP(gid, sid_type, bname.decode(), bcomment.decode())
+
+
+def _parse_memberof(tdb_key: str, tdb_val: str) -> GROUP_MEMBER:
+    sid = tdb_key[len(MEMBEROF_PREFIX):]
+    data = b64decode(tdb_val)
+
+    members = tuple(data[:-1].decode().split())
+    return GROUPMEM(sid, members)