packet lib: sctp: fix reversibility about json

although SCTP is using internal classes, no class is registered into '_class_prefixes'.
therefore, AssertionError occurs in from_jsondict() when the argument 'param' was processed.
this patch makes from_jsondict() to work correctly by registering internal classes into '_class_prefixes'.

examination code:

    from ryu.lib.packet import sctp
    msg1 = sctp.sctp(chunks=[sctp.chunk_init(params=[sctp.param_cookie_preserve()])])
    print msg1
    jsondict = msg1.to_jsondict()
    msg2 = sctp.sctp.from_jsondict(jsondict['sctp'])
    print msg2
    print str(msg1) == str(msg2)

before applying this patch:

    sctp(chunks=[chunk_init(a_rwnd=0,flags=0,i_tsn=0,init_tag=0,length=0,mis=0,os=0,params=[param_cookie_preserve(length=0,value=0)])],csum=0,dst_port=0,src_port=0,vtag=0)
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 291, in from_jsondict
        kwargs = cls._restore_args(_mapdict_kv(decode, dict_))
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 46, in <lambda>
        _mapdict_kv = lambda f, d: dict([(k, f(k, v)) for k, v in d.items()])
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 290, in <lambda>
        decode = lambda k, x: cls._decode_value(k, x, decode_string)
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 234, in _decode_value
        return cls._get_decoder(k, decode_string)(json_value)
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 242, in _decode
        v = map(_decode, json_value)
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 245, in _decode
        v = cls.obj_from_jsondict(json_value)
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 223, in obj_from_jsondict
        return obj_cls.from_jsondict(v)
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/stringify.py", line 293, in from_jsondict
        return cls(**dict(kwargs, **additional_args))
      File "/usr/local/lib/python2.7/dist-packages/ryu/lib/packet/sctp.py", line 273, in __init__
        assert isinstance(one, param)
    AssertionError

after applying this patch:

    sctp(chunks=[chunk_init(a_rwnd=0,flags=0,i_tsn=0,init_tag=0,length=0,mis=0,os=0,params=[param_cookie_preserve(length=0,value=0)])],csum=0,dst_port=0,src_port=0,vtag=0)
    sctp(chunks=[chunk_init(a_rwnd=0,flags=0,i_tsn=0,init_tag=0,length=0,mis=0,os=0,params=[param_cookie_preserve(length=0,value=0)])],csum=0,dst_port=0,src_port=0,vtag=0)
    True

Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 4 insertions, 0 deletions

diff --git a/ryu/lib/packet/sctp.py b/ryu/lib/packet/sctp.py
index c5bb9ed7..e984dc21 100644
--- a/ryu/lib/packet/sctp.py
+++ b/ryu/lib/packet/sctp.py
@@ -257,6 +257,7 @@ class chunk_init_base(chunk):
     __metaclass__ = abc.ABCMeta
     _PACK_STR = '!BBHIIHHI'
     _MIN_LEN = struct.calcsize(_PACK_STR)
+    _class_prefixes = ['param_']
 
     def __init__(self, flags=0, length=0, init_tag=0, a_rwnd=0, os=0,
                  mis=0, i_tsn=0, params=None):
@@ -306,6 +307,7 @@ class chunk_init_base(chunk):
 class chunk_heartbeat_base(chunk):
 
     __metaclass__ = abc.ABCMeta
+    _class_prefixes = ['param_']
 
     def __init__(self, flags=0, length=0, info=None):
         super(chunk_heartbeat_base, self).__init__(
@@ -1448,6 +1450,7 @@ class cause_unresolvable_addr(cause_with_value):
     ============== =====================================================
     """
 
+    _class_prefixes = ['param_']
     _RECOGNIZED_PARAMS = {}
 
     @staticmethod
@@ -1662,6 +1665,7 @@ class cause_restart_with_new_addr(cause_with_value):
     ============== =====================================================
     """
 
+    _class_prefixes = ['param_']
     _RECOGNIZED_PARAMS = {}
 
     @staticmethod