packet lib: icmpv6: add nd_router messages

add ICMPv6 sub encoder/decoder class for Router Solicitation and
Router Advertisement messages.

add ICMPv6 sub encoder/decoder class for Neighbor discovery
Prefix Information Option.

Signed-off-by: Ygor Amaral <yabls@cin.ufpe.br>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

2 files changed, 316 insertions, 25 deletions

diff --git a/ryu/lib/packet/icmpv6.py b/ryu/lib/packet/icmpv6.py
index ac1d5349..1ad2e68e 100644
--- a/ryu/lib/packet/icmpv6.py
+++ b/ryu/lib/packet/icmpv6.py
@@ -214,8 +214,192 @@ class nd_neighbor(stringify.StringifyMixin):
         return hdr
 
 
+@icmpv6.register_icmpv6_type(ND_ROUTER_SOLICIT)
+class nd_router_solicit(stringify.StringifyMixin):
+    """ICMPv6 sub encoder/decoder class for Router Solicitation messages.
+    (RFC 4861)
+
+    This is used with ryu.lib.packet.icmpv6.icmpv6.
+
+    An instance has the following attributes at least.
+    Most of them are same to the on-wire counterparts but in host byte order.
+    __init__ takes the correspondig args in this order.
+
+    .. tabularcolumns:: |l|p{35em}|
+
+    ============== ====================
+    Attribute      Description
+    ============== ====================
+    res            This field is unused.  It MUST be initialized to zero.
+    type\_         "Type" field of the first option.  None if no options. \
+                   NOTE: This implementation doesn't support two or more \
+                   options.
+    length         "Length" field of the first option.  None if no options.
+    data           An object to describe the first option. \
+                   None if no options. \
+                   Either ryu.lib.packet.icmpv6.nd_option_la object \
+                   or a bytearray.
+    ============== ====================
+    """
+
+    _PACK_STR = '!I'
+    _MIN_LEN = struct.calcsize(_PACK_STR)
+    _ND_OPTION_TYPES = {}
+
+    # ND option type
+    ND_OPTION_SLA = 1  # Source Link-Layer Address
+
+    @staticmethod
+    def register_nd_option_type(*args):
+        def _register_nd_option_type(cls):
+            for type_ in args:
+                nd_router_solicit._ND_OPTION_TYPES[type_] = cls
+            return cls
+        return _register_nd_option_type
+
+    def __init__(self, res, type_=None, length=None, data=None):
+        self.res = res
+        self.type_ = type_
+        self.length = length
+        self.data = data
+
+    @classmethod
+    def parser(cls, buf, offset):
+        res = struct.unpack_from(cls._PACK_STR, buf, offset)
+        msg = cls(res)
+        offset += cls._MIN_LEN
+        if len(buf) > offset:
+            (msg.type_, msg.length) = struct.unpack_from('!BB', buf, offset)
+            cls_ = cls._ND_OPTION_TYPES.get(msg.type_, None)
+            offset += 2
+            if cls_:
+                msg.data = cls_.parser(buf, offset)
+            else:
+                msg.data = buf[offset:]
+
+        return msg
+
+    def serialize(self):
+        hdr = bytearray(struct.pack(nd_router_solicit._PACK_STR, self.res))
+
+        if self.type_ is not None:
+            hdr += bytearray(struct.pack('!BB', self.type_, self.length))
+            if self.type_ in nd_router_solicit._ND_OPTION_TYPES:
+                hdr += self.data.serialize()
+            elif self.data is not None:
+                hdr += bytearray(self.data)
+
+        return hdr
+
+
+@icmpv6.register_icmpv6_type(ND_ROUTER_ADVERT)
+class nd_router_advert(stringify.StringifyMixin):
+    """ICMPv6 sub encoder/decoder class for Router Advertisement messages.
+    (RFC 4861)
+
+    This is used with ryu.lib.packet.icmpv6.icmpv6.
+
+    An instance has the following attributes at least.
+    Most of them are same to the on-wire counterparts but in host byte order.
+    __init__ takes the correspondig args in this order.
+
+    .. tabularcolumns:: |l|p{35em}|
+
+    ============== ====================
+    Attribute      Description
+    ============== ====================
+    ch_l           Cur Hop Limit.
+    res            M,O Flags for Router Advertisement.
+    rou_l          Router Lifetime.
+    rea_t          Reachable Time.
+    ret_t          Retrans Timer.
+    type\_         List of option type. Each index refers to an option. \
+                   None if no options. \
+                   NOTE: This implementation support one or more \
+                   options.
+    length         List of option length. Each index refers to an option. \
+                   None if no options. \
+    data           List of option data. Each index refers to an option. \
+                   None if no options. \
+                   ryu.lib.packet.icmpv6.nd_option_la object, \
+                   ryu.lib.packet.icmpv6.nd_option_pi object \
+                   or a bytearray.
+    ============== ====================
+    """
+
+    _PACK_STR = '!BBHII'
+    _MIN_LEN = struct.calcsize(_PACK_STR)
+    _ND_OPTION_TYPES = {}
+
+    # ND option type
+    ND_OPTION_SLA = 1  # Source Link-Layer Address
+    ND_OPTION_PI = 3   # Prefix Information
+    ND_OPTION_MTU = 5  # MTU
+
+    @staticmethod
+    def register_nd_option_type(*args):
+        def _register_nd_option_type(cls):
+            for type_ in args:
+                nd_router_advert._ND_OPTION_TYPES[type_] = cls
+            return cls
+        return _register_nd_option_type
+
+    def __init__(self, ch_l, res, rou_l, rea_t, ret_t, type_=None, length=None,
+                 data=None):
+        self.ch_l = ch_l
+        self.res = res << 6
+        self.rou_l = rou_l
+        self.rea_t = rea_t
+        self.ret_t = ret_t
+        self.type_ = type_
+        self.length = length
+        self.data = data
+
+    @classmethod
+    def parser(cls, buf, offset):
+        (ch_l, res, rou_l, rea_t, ret_t) = struct.unpack_from(cls._PACK_STR,
+                                                              buf, offset)
+        msg = cls(ch_l, res >> 6, rou_l, rea_t, ret_t)
+        offset += cls._MIN_LEN
+        msg.type_ = list()
+        msg.length = list()
+        msg.data = list()
+        while len(buf) > offset:
+            (type_, length) = struct.unpack_from('!BB', buf, offset)
+            msg.type_.append(type_)
+            msg.length.append(length)
+            cls_ = cls._ND_OPTION_TYPES.get(type_, None)
+            offset += 2
+            if cls_:
+                msg.data.append(cls_.parser(buf[:offset+cls_._MIN_LEN],
+                                            offset))
+                offset += cls_._MIN_LEN
+            else:
+                msg.data.append(buf[offset:])
+                offset = len(buf)
+
+        return msg
+
+    def serialize(self):
+        hdr = bytearray(struct.pack(nd_router_advert._PACK_STR, self.ch_l,
+                                    self.res, self.rou_l, self.rea_t,
+                                    self.ret_t))
+        if self.type_ is not None:
+            for i in range(len(self.type_)):
+                hdr += bytearray(struct.pack('!BB', self.type_[i],
+                                             self.length[i]))
+                if self.type_[i] in nd_router_advert._ND_OPTION_TYPES:
+                    hdr += self.data[i].serialize()
+                elif self.data[i] is not None:
+                    hdr += bytearray(self.data[i])
+
+        return hdr
+
+
 @nd_neighbor.register_nd_option_type(nd_neighbor.ND_OPTION_SLA,
                                      nd_neighbor.ND_OPTION_TLA)
+@nd_router_solicit.register_nd_option_type(nd_router_solicit.ND_OPTION_SLA)
+@nd_router_advert.register_nd_option_type(nd_router_advert.ND_OPTION_SLA)
 class nd_option_la(stringify.StringifyMixin):
     """ICMPv6 sub encoder/decoder class for Neighbor discovery
     Source/Target Link-Layer Address Option. (RFC 4861)
@@ -270,6 +454,63 @@ class nd_option_la(stringify.StringifyMixin):
         return hdr
 
 
+@nd_router_advert.register_nd_option_type(nd_router_advert.ND_OPTION_PI)
+class nd_option_pi(stringify.StringifyMixin):
+    """ICMPv6 sub encoder/decoder class for Neighbor discovery
+    Prefix Information Option. (RFC 4861)
+
+    This is used with ryu.lib.packet.icmpv6.nd_neighbor.
+
+    An instance has the following attributes at least.
+    Most of them are same to the on-wire counterparts but in host byte order.
+    __init__ takes the correspondig args in this order.
+
+    .. tabularcolumns:: |l|p{35em}|
+
+    ============== ====================
+    Attribute      Description
+    ============== ====================
+    pl             Prefix Length.
+    res1           L,A,R* Flags for Prefix Information.
+    val_l          Valid Lifetime.
+    pre_l          Preferred Lifetime.
+    res2           This field is unused. It MUST be initialized to zero.
+    prefix         An IP address or a prefix of an IP address.
+    ============== ====================
+
+    *R flag is defined in (RFC 3775)
+    """
+
+    _PACK_STR = '!BBIII16s'
+    _MIN_LEN = struct.calcsize(_PACK_STR)
+
+    def __init__(self, pl, res1, val_l, pre_l, res2, prefix):
+        self.pl = pl
+        self.res1 = res1 << 5
+        self.val_l = val_l
+        self.pre_l = pre_l
+        self.res2 = res2
+        self.prefix = prefix
+
+    @classmethod
+    def parser(cls, buf, offset):
+        (pl, res1, val_l, pre_l, res2, prefix) = struct.unpack_from(cls.
+                                                                    _PACK_STR,
+                                                                    buf,
+                                                                    offset)
+        msg = cls(pl, res1 >> 5, val_l, pre_l, res2,
+                  addrconv.ipv6.bin_to_text(prefix))
+
+        return msg
+
+    def serialize(self):
+        hdr = bytearray(struct.pack(self._PACK_STR, self.pl, self.res1,
+                                    self.val_l, self.pre_l, self.res2,
+                                    addrconv.ipv6.text_to_bin(self.prefix)))
+
+        return hdr
+
+
 @icmpv6.register_icmpv6_type(ICMPV6_ECHO_REPLY, ICMPV6_ECHO_REQUEST)
 class echo(stringify.StringifyMixin):
     """ICMPv6 sub encoder/decoder class for Echo Request and Echo Reply
diff --git a/ryu/tests/unit/packet/test_icmpv6.py b/ryu/tests/unit/packet/test_icmpv6.py
index 848ecf9d..0a33ca0a 100644
--- a/ryu/tests/unit/packet/test_icmpv6.py
+++ b/ryu/tests/unit/packet/test_icmpv6.py
@@ -347,10 +347,11 @@ class Test_icmpv6_router_solict(unittest.TestCase):
     res = 0
     nd_type = 1
     nd_length = 1
-    nd_data = None
-    nd_hw_src = '\x12\x2d\xa5\x6d\xbc\x0f'
+    nd_hw_src = '12:2d:a5:6d:bc:0f'
     data = '\x00\x00\x00\x00\x01\x01\x12\x2d\xa5\x6d\xbc\x0f'
     buf = '\x85\x00\x97\xd9'
+    src_ipv6 = '3ffe:507:0:1:200:86ff:fe05:80da'
+    dst_ipv6 = '3ffe:501:0:1001::2'
 
     def setUp(self):
         pass
@@ -359,7 +360,11 @@ class Test_icmpv6_router_solict(unittest.TestCase):
         pass
 
     def test_init(self):
-        pass
+        rs = icmpv6.nd_router_solicit(self.res)
+        eq_(rs.res, self.res)
+        eq_(rs.type_, None)
+        eq_(rs.length, None)
+        eq_(rs.data, None)
 
     def _test_parser(self, data=None):
         buf = self.buf + str(data or '')
@@ -368,7 +373,15 @@ class Test_icmpv6_router_solict(unittest.TestCase):
         eq_(msg.type_, self.type_)
         eq_(msg.code, self.code)
         eq_(msg.csum, self.csum)
-        eq_(msg.data, data)
+        if data is not None:
+            eq_(msg.data.res[0], self.res)
+        eq_(n, None)
+        if data:
+            rs = msg.data
+            eq_(rs.type_, self.nd_type)
+            eq_(rs.length, self.nd_length)
+            eq_(rs.data.hw_src, self.nd_hw_src)
+            eq_(rs.data.data, None)
 
     def test_parser_without_data(self):
         self._test_parser()
@@ -376,38 +389,75 @@ class Test_icmpv6_router_solict(unittest.TestCase):
     def test_parser_with_data(self):
         self._test_parser(self.data)
 
-    def _test_serialize(self, nd_data=None):
-        nd_data = str(nd_data or '')
-        buf = self.buf + nd_data
-        src_ipv6 = 'fe80::102d:a5ff:fe6d:bc0f'
-        dst_ipv6 = 'ff02::2'
-        prev = ipv6(6, 0, 0, len(buf), 58, 255, src_ipv6, dst_ipv6)
-        nd_csum = icmpv6_csum(prev, buf)
+    def test_serialize_without_data(self):
+        rs = icmpv6.nd_router_solicit(self.res)
+        prev = ipv6(6, 0, 0, 8, 64, 255, self.src_ipv6, self.dst_ipv6)
+        rs_csum = icmpv6_csum(prev, self.buf)
 
-        icmp = icmpv6.icmpv6(self.type_, self.code, 0, nd_data)
+        icmp = icmpv6.icmpv6(self.type_, self.code, 0, rs)
         buf = buffer(icmp.serialize(bytearray(), prev))
+
         (type_, code, csum) = struct.unpack_from(icmp._PACK_STR, buf, 0)
-        data = buf[icmp._MIN_LEN:]
+        res = struct.unpack_from(rs._PACK_STR, buf, icmp._MIN_LEN)
+        data = buf[(icmp._MIN_LEN + rs._MIN_LEN):]
 
         eq_(type_, self.type_)
         eq_(code, self.code)
-        eq_(csum, nd_csum)
-        eq_(data, nd_data)
-
-    def test_serialize_without_data(self):
-        self._test_serialize()
+        eq_(csum, rs_csum)
+        eq_(res[0], self.res)
+        eq_(data, '')
 
     def test_serialize_with_data(self):
-        self._test_serialize(self.data)
+        nd_opt = icmpv6.nd_option_la(self.nd_hw_src)
+        rs = icmpv6.nd_router_solicit(self.res, self.nd_type, self.nd_length,
+                                      nd_opt)
+        prev = ipv6(6, 0, 0, 16, 64, 255, self.src_ipv6, self.dst_ipv6)
+        rs_csum = icmpv6_csum(prev, self.buf + self.data)
+
+        icmp = icmpv6.icmpv6(self.type_, self.code, 0, rs)
+        buf = buffer(icmp.serialize(bytearray(), prev))
+
+        (type_, code, csum) = struct.unpack_from(icmp._PACK_STR, buf, 0)
+        res = struct.unpack_from(rs._PACK_STR, buf, icmp._MIN_LEN)
+        (nd_type, nd_length, nd_hw_src) = struct.unpack_from(
+            '!BB6s', buf, icmp._MIN_LEN + rs._MIN_LEN)
+        data = buf[(icmp._MIN_LEN + rs._MIN_LEN + 8):]
+
+        eq_(type_, self.type_)
+        eq_(code, self.code)
+        eq_(csum, rs_csum)
+        eq_(res[0], self.res)
+        eq_(nd_type, self.nd_type)
+        eq_(nd_length, self.nd_length)
+        eq_(nd_hw_src, addrconv.mac.text_to_bin(self.nd_hw_src))
 
     def test_to_string(self):
-        ic = icmpv6.icmpv6(self.type_, self.code, self.csum, self.data)
+        nd_opt = icmpv6.nd_option_la(self.nd_hw_src)
+        rs = icmpv6.nd_router_solicit(
+            self.res, self.nd_type, self.nd_length, nd_opt)
+        ic = icmpv6.icmpv6(self.type_, self.code, self.csum, rs)
 
-        icmp_values = {'type_': self.type_,
-                       'code': self.code,
-                       'csum': self.csum,
-                       'data': self.data}
-        _ic_str = ','.join(['%s=%s' % (k, repr(icmp_values[k]))
+        nd_opt_values = {'hw_src': self.nd_hw_src,
+                         'data': None}
+        _nd_opt_str = ','.join(['%s=%s' % (k, repr(nd_opt_values[k]))
+                                for k, v in inspect.getmembers(nd_opt)
+                                if k in nd_opt_values])
+        nd_opt_str = '%s(%s)' % (icmpv6.nd_option_la.__name__, _nd_opt_str)
+
+        rs_values = {'res': repr(rs.res),
+                     'type_': repr(self.nd_type),
+                     'length': repr(self.nd_length),
+                     'data': nd_opt_str}
+        _rs_str = ','.join(['%s=%s' % (k, rs_values[k])
+                            for k, v in inspect.getmembers(rs)
+                            if k in rs_values])
+        rs_str = '%s(%s)' % (icmpv6.nd_router_solicit.__name__, _rs_str)
+
+        icmp_values = {'type_': repr(self.type_),
+                       'code': repr(self.code),
+                       'csum': repr(self.csum),
+                       'data': rs_str}
+        _ic_str = ','.join(['%s=%s' % (k, icmp_values[k])
                             for k, v in inspect.getmembers(ic)
                             if k in icmp_values])
         ic_str = '%s(%s)' % (icmpv6.icmpv6.__name__, _ic_str)