Add ipv6addr() nftables expr helper.

pyroute2/nftables/expressions.py

@@ -86,3 +86,56 @@ def ipv4addr(src=None, dst=None):
     kwarg['data'] = {'attrs': [('NFTA_DATA_VALUE', packed)]}
     ret.append(genex('cmp', kwarg))
     return ret
+
+
+def ipv6addr(src=None, dst=None):
+    if not src and not dst:
+        raise ValueError('must be at least one of src, dst')
+
+    ret = []
+    # get masks
+    src, src_mask = get_mask(src)
+    dst, dst_mask = get_mask(dst)
+
+    # load address(es) into NFT_REG_1
+    kwarg = OrderedDict()
+    kwarg['dreg'] = 1  # save to NFT_REG_1
+    kwarg['base'] = 1  # NFT_PAYLOAD_NETWORK_HEADER
+    kwarg['offset'] = 8 if src else 24
+    kwarg['len'] = 32 if (src and dst) else 16
+    ret.append(genex('payload', kwarg))
+
+    # run bitwise with masks -- if provided
+    if src_mask or dst_mask:
+        mask = b''
+        if src:
+            if not src_mask:
+                src_mask = '128'
+            src_mask = int('1' * int(src_mask), 2)
+            mask += struct.pack('QQ', src_mask)
+        if dst:
+            if not dst_mask:
+                dst_mask = '128'
+            dst_mask = int('1' * int(dst_mask), 2)
+            mask += struct.pack('QQ', dst_mask)
+        xor = '\x00' * len(mask)
+        kwarg = OrderedDict()
+        kwarg['sreg'] = 1  # read from NFT_REG_1
+        kwarg['dreg'] = 1  # save to NFT_REG_1
+        kwarg['len'] = 32 if (src and dst) else 16
+        kwarg['mask'] = {'attrs': [('NFTA_DATA_VALUE', mask)]}
+        kwarg['xor'] = {'attrs': [('NFTA_DATA_VALUE', xor)]}
+        ret.append(genex('bitwise', kwarg))
+
+    # run cmp
+    packed = b''
+    if src:
+        packed += socket.inet_pton(socket.AF_INET6,src)
+    if dst:
+        packed += socket.inet_pton(socket.AF_INET6,dst)
+    kwarg = OrderedDict()
+    kwarg['sreg'] = 1  # read from NFT_REG_1
+    kwarg['op'] = 0  # NFT_CMP_EQ
+    kwarg['data'] = {'attrs': [('NFTA_DATA_VALUE', packed)]}
+    ret.append(genex('cmp', kwarg))
+    return ret