packet lib: icmpv6: support default parameters and the auto calculation of lengths

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

2 files changed, 443 insertions, 13 deletions

diff --git a/ryu/lib/packet/icmpv6.py b/ryu/lib/packet/icmpv6.py
index bcf1fff7..d4bb00b9 100644
--- a/ryu/lib/packet/icmpv6.py
+++ b/ryu/lib/packet/icmpv6.py
@@ -102,7 +102,7 @@ class icmpv6(packet_base.PacketBase):
             return cls
         return _register_icmpv6_type
 
-    def __init__(self, type_, code, csum, data=None):
+    def __init__(self, type_=0, code=0, csum=0, data=None):
         super(icmpv6, self).__init__()
         self.type_ = type_
         self.code = code
@@ -180,7 +180,7 @@ class nd_neighbor(stringify.StringifyMixin):
             return cls
         return _register_nd_option_type(args[0])
 
-    def __init__(self, res, dst, option=None):
+    def __init__(self, res=0, dst='::', option=None):
         self.res = res
         self.dst = dst
         self.option = option
@@ -252,7 +252,7 @@ class nd_router_solicit(stringify.StringifyMixin):
             return cls
         return _register_nd_option_type(args[0])
 
-    def __init__(self, res, option=None):
+    def __init__(self, res=0, option=None):
         self.res = res
         self.option = option
 
@@ -326,7 +326,7 @@ class nd_router_advert(stringify.StringifyMixin):
             return cls
         return _register_nd_option_type(args[0])
 
-    def __init__(self, ch_l, res, rou_l, rea_t, ret_t, options=None):
+    def __init__(self, ch_l=0, res=0, rou_l=0, rea_t=0, ret_t=0, options=None):
         self.ch_l = ch_l
         self.res = res
         self.rou_l = rou_l
@@ -430,6 +430,9 @@ class nd_option_la(nd_option):
         mod = len(buf) % 8
         if mod:
             buf.extend(bytearray(8 - mod))
+        if 0 == self.length:
+            self.length = len(buf) / 8
+            struct.pack_into('!B', buf, 1, self.length)
         return str(buf)
 
     def __len__(self):
@@ -459,7 +462,8 @@ class nd_option_sla(nd_option_la):
     ============== ====================
     Attribute      Description
     ============== ====================
-    length         length of the option.
+    length         length of the option. \
+                   (0 means automatically-calculate when encoding)
     hw_src         Link-Layer Address. \
                    NOTE: If the address is longer than 6 octets this contains \
                    the first 6 octets in the address. \
@@ -476,7 +480,7 @@ class nd_option_sla(nd_option_la):
     def option_type(cls):
         return ND_OPTION_SLA
 
-    def __init__(self, length, hw_src, data=None):
+    def __init__(self, length=0, hw_src='00:00:00:00:00:00', data=None):
         super(nd_option_sla, self).__init__(length, hw_src, data)
 
 
@@ -496,7 +500,8 @@ class nd_option_tla(nd_option_la):
     ============== ====================
     Attribute      Description
     ============== ====================
-    length         length of the option.
+    length         length of the option. \
+                   (0 means automatically-calculate when encoding)
     hw_src         Link-Layer Address. \
                    NOTE: If the address is longer than 6 octets this contains \
                    the first 6 octets in the address. \
@@ -513,7 +518,7 @@ class nd_option_tla(nd_option_la):
     def option_type(cls):
         return ND_OPTION_TLA
 
-    def __init__(self, length, hw_src, data=None):
+    def __init__(self, length=0, hw_src='00:00:00:00:00:00', data=None):
         super(nd_option_tla, self).__init__(length, hw_src, data)
 
 
@@ -533,7 +538,8 @@ class nd_option_pi(nd_option):
     ============== ====================
     Attribute      Description
     ============== ====================
-    length         length of the option.
+    length         length of the option. \
+                   (0 means automatically-calculate when encoding)
     pl             Prefix Length.
     res1           L,A,R\* Flags for Prefix Information.
     val_l          Valid Lifetime.
@@ -552,7 +558,8 @@ class nd_option_pi(nd_option):
     def option_type(cls):
         return ND_OPTION_PI
 
-    def __init__(self, length, pl, res1, val_l, pre_l, res2, prefix):
+    def __init__(self, length=0, pl=0, res1=0, val_l=0, pre_l=0, res2=0,
+                 prefix='::'):
         super(nd_option_pi, self).__init__(self.option_type(), length)
         self.pl = pl
         self.res1 = res1
@@ -576,8 +583,10 @@ class nd_option_pi(nd_option):
             self._PACK_STR, self.option_type(), self.length, self.pl,
             res1, self.val_l, self.pre_l, self.res2,
             addrconv.ipv6.text_to_bin(self.prefix)))
-
-        return hdr
+        if 0 == self.length:
+            self.length = len(hdr) / 8
+            struct.pack_into('!B', hdr, 1, self.length)
+        return str(hdr)
 
 
 @icmpv6.register_icmpv6_type(ICMPV6_ECHO_REPLY, ICMPV6_ECHO_REQUEST)
@@ -604,7 +613,7 @@ class echo(stringify.StringifyMixin):
     _PACK_STR = '!HH'
     _MIN_LEN = struct.calcsize(_PACK_STR)
 
-    def __init__(self, id_, seq, data=None):
+    def __init__(self, id_=0, seq=0, data=None):
         self.id = id_
         self.seq = seq
         self.data = data
diff --git a/ryu/tests/unit/packet/test_icmpv6.py b/ryu/tests/unit/packet/test_icmpv6.py
index 43ba8c4e..21167c92 100644
--- a/ryu/tests/unit/packet/test_icmpv6.py
+++ b/ryu/tests/unit/packet/test_icmpv6.py
@@ -89,6 +89,17 @@ class Test_icmpv6_header(unittest.TestCase):
         m_short_buf = self.buf[1:self.icmp._MIN_LEN]
         self.icmp.parser(m_short_buf)
 
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6()
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
 
 class Test_icmpv6_echo_request(unittest.TestCase):
     type_ = 128
@@ -182,6 +193,23 @@ class Test_icmpv6_echo_request(unittest.TestCase):
         eq_(str(ic), ic_str)
         eq_(repr(ic), ic_str)
 
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ICMPV6_ECHO_REQUEST, data=icmpv6.echo())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ICMPV6_ECHO_REQUEST)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.echo._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+
 
 class Test_icmpv6_echo_reply(Test_icmpv6_echo_request):
     def setUp(self):
@@ -189,6 +217,23 @@ class Test_icmpv6_echo_reply(Test_icmpv6_echo_request):
         self.csum = 0xa472
         self.buf = '\x81\x00\xa4\x72\x76\x20\x00\x00'
 
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ICMPV6_ECHO_REPLY, data=icmpv6.echo())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ICMPV6_ECHO_REPLY)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.echo._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+
 
 class Test_icmpv6_neighbor_solicit(unittest.TestCase):
     type_ = 135
@@ -317,6 +362,48 @@ class Test_icmpv6_neighbor_solicit(unittest.TestCase):
         eq_(str(ic), ic_str)
         eq_(repr(ic), ic_str)
 
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_NEIGHBOR_SOLICIT, data=icmpv6.nd_neighbor())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_NEIGHBOR_SOLICIT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_neighbor._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+        eq_(res[1], addrconv.ipv6.text_to_bin('::'))
+
+        # with nd_option_sla
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_NEIGHBOR_SOLICIT,
+            data=icmpv6.nd_neighbor(
+                option=icmpv6.nd_option_sla()))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_NEIGHBOR_SOLICIT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_neighbor._PACK_STR, str(buf[4:24]))
+
+        eq_(res[0], 0)
+        eq_(res[1], addrconv.ipv6.text_to_bin('::'))
+
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf[24:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
 
 class Test_icmpv6_neighbor_advert(Test_icmpv6_neighbor_solicit):
     def setUp(self):
@@ -390,6 +477,48 @@ class Test_icmpv6_neighbor_advert(Test_icmpv6_neighbor_solicit):
         eq_(str(ic), ic_str)
         eq_(repr(ic), ic_str)
 
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_NEIGHBOR_ADVERT, data=icmpv6.nd_neighbor())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_NEIGHBOR_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_neighbor._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+        eq_(res[1], addrconv.ipv6.text_to_bin('::'))
+
+        # with nd_option_tla
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_NEIGHBOR_ADVERT,
+            data=icmpv6.nd_neighbor(
+                option=icmpv6.nd_option_tla()))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_NEIGHBOR_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_neighbor._PACK_STR, str(buf[4:24]))
+
+        eq_(res[0], 0)
+        eq_(res[1], addrconv.ipv6.text_to_bin('::'))
+
+        res = struct.unpack(icmpv6.nd_option_tla._PACK_STR, str(buf[24:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_TLA)
+        eq_(res[1], len(icmpv6.nd_option_tla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
 
 class Test_icmpv6_router_solicit(unittest.TestCase):
     type_ = 133
@@ -509,3 +638,295 @@ class Test_icmpv6_router_solicit(unittest.TestCase):
 
         eq_(str(ic), ic_str)
         eq_(repr(ic), ic_str)
+
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_SOLICIT, data=icmpv6.nd_router_solicit())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_SOLICIT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_solicit._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+
+        # with nd_option_sla
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_SOLICIT,
+            data=icmpv6.nd_router_solicit(
+                option=icmpv6.nd_option_sla()))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_SOLICIT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_solicit._PACK_STR, str(buf[4:8]))
+
+        eq_(res[0], 0)
+
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf[8:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+
+class Test_icmpv6_router_advert(unittest.TestCase):
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_default_args(self):
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_ADVERT, data=icmpv6.nd_router_advert())
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_advert._PACK_STR, str(buf[4:]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+
+        # with nd_option_sla
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_ADVERT,
+            data=icmpv6.nd_router_advert(
+                options=[icmpv6.nd_option_sla()]))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_advert._PACK_STR, str(buf[4:16]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf[16:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+        # with nd_option_pi
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_ADVERT,
+            data=icmpv6.nd_router_advert(
+                options=[icmpv6.nd_option_pi()]))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_advert._PACK_STR, str(buf[4:16]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+
+        res = struct.unpack(icmpv6.nd_option_pi._PACK_STR, str(buf[16:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_PI)
+        eq_(res[1], 4)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+        eq_(res[5], 0)
+        eq_(res[6], 0)
+        eq_(res[7], addrconv.ipv6.text_to_bin('::'))
+
+        # with nd_option_sla and nd_option_pi
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_ADVERT,
+            data=icmpv6.nd_router_advert(
+                options=[icmpv6.nd_option_sla(), icmpv6.nd_option_pi()]))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_advert._PACK_STR, str(buf[4:16]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf[16:24]))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+        res = struct.unpack(icmpv6.nd_option_pi._PACK_STR, str(buf[24:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_PI)
+        eq_(res[1], len(icmpv6.nd_option_pi()) / 8)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+        eq_(res[5], 0)
+        eq_(res[6], 0)
+        eq_(res[7], addrconv.ipv6.text_to_bin('::'))
+
+
+class Test_icmpv6_nd_option_la(unittest.TestCase):
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_default_args(self):
+        la = icmpv6.nd_option_sla()
+        buf = la.serialize()
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+        # with nd_neighbor
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_NEIGHBOR_ADVERT,
+            data=icmpv6.nd_neighbor(
+                option=icmpv6.nd_option_tla()))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_NEIGHBOR_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_neighbor._PACK_STR, str(buf[4:24]))
+
+        eq_(res[0], 0)
+        eq_(res[1], addrconv.ipv6.text_to_bin('::'))
+
+        res = struct.unpack(icmpv6.nd_option_tla._PACK_STR, str(buf[24:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_TLA)
+        eq_(res[1], len(icmpv6.nd_option_tla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+        # with nd_router_solicit
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_SOLICIT,
+            data=icmpv6.nd_router_solicit(
+                option=icmpv6.nd_option_sla()))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_SOLICIT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_solicit._PACK_STR, str(buf[4:8]))
+
+        eq_(res[0], 0)
+
+        res = struct.unpack(icmpv6.nd_option_sla._PACK_STR, str(buf[8:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_SLA)
+        eq_(res[1], len(icmpv6.nd_option_sla()) / 8)
+        eq_(res[2], addrconv.mac.text_to_bin('00:00:00:00:00:00'))
+
+
+class Test_icmpv6_nd_option_pi(unittest.TestCase):
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_default_args(self):
+        pi = icmpv6.nd_option_pi()
+        buf = pi.serialize()
+        res = struct.unpack(icmpv6.nd_option_pi._PACK_STR, str(buf))
+
+        eq_(res[0], icmpv6.ND_OPTION_PI)
+        eq_(res[1], len(icmpv6.nd_option_pi()) / 8)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+        eq_(res[5], 0)
+        eq_(res[6], 0)
+        eq_(res[7], addrconv.ipv6.text_to_bin('::'))
+
+        # with nd_router_advert
+        prev = ipv6(nxt=inet.IPPROTO_ICMPV6)
+        ic = icmpv6.icmpv6(
+            type_=icmpv6.ND_ROUTER_ADVERT,
+            data=icmpv6.nd_router_advert(
+                options=[icmpv6.nd_option_pi()]))
+        prev.serialize(ic, None)
+        buf = ic.serialize(bytearray(), prev)
+        res = struct.unpack(icmpv6.icmpv6._PACK_STR, str(buf[:4]))
+
+        eq_(res[0], icmpv6.ND_ROUTER_ADVERT)
+        eq_(res[1], 0)
+        eq_(res[2], icmpv6_csum(prev, buf))
+
+        res = struct.unpack(icmpv6.nd_router_advert._PACK_STR, str(buf[4:16]))
+
+        eq_(res[0], 0)
+        eq_(res[1], 0)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+
+        res = struct.unpack(icmpv6.nd_option_pi._PACK_STR, str(buf[16:]))
+
+        eq_(res[0], icmpv6.ND_OPTION_PI)
+        eq_(res[1], 4)
+        eq_(res[2], 0)
+        eq_(res[3], 0)
+        eq_(res[4], 0)
+        eq_(res[5], 0)
+        eq_(res[6], 0)
+        eq_(res[7], addrconv.ipv6.text_to_bin('::'))