"""Map utilities library."""
+import ipaddress
+
from resources.libraries.python.VatExecutor import VatExecutor
if output[0]["retval"] != 0:
raise RuntimeError('Unable to add map rule on node {}'
.format(vpp_node['host']))
+
+ @staticmethod
+ def map_del_domain(vpp_node, index):
+ """Delete map domain on node.
+
+ :param vpp_node: VPP node to delete map domain on.
+ :param index: Index of the map domain.
+ :type vpp_node: dict
+ :type index: int
+ :raises RuntimeError: If unable to delete map domain.
+ """
+ output = VatExecutor.cmd_from_template(vpp_node, "map_del_domain.vat",
+ index=index)
+ if output[0]["retval"] != 0:
+ raise RuntimeError('Unable to delete map domain {} on node {}'
+ .format(index, vpp_node['host']))
+
+ @staticmethod
+ def get_psid_from_port(port, psid_len, psid_offset):
+ """Return PSID from port.
+ 0 1
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+ +-----------+-----------+-------+
+ Ports in | A | PSID | j |
+ the CE port set | > 0 | | |
+ +-----------+-----------+-------+
+ | a bits | k bits |m bits |
+
+
+ :param port: Port to compute PSID from.
+ :param psid_len: PSID length.
+ :param psid_offset: PSID offset.
+ :type port: int
+ :type psid_len: int
+ :type psid_offset: int
+
+ :return: PSID.
+ :rtype: int
+ """
+ ones = 2**16-1
+ mask = ones >> (16 - psid_len)
+ psid = port >> (16 - psid_len - psid_offset)
+ psid &= mask
+ return psid
+
+ @staticmethod
+ def _make_ea_bits(ipv4_net, ipv4_host, ea_bit_len, psid_len, psid):
+ """
+ _note_: host(or prefix) part of destination ip in rule prefix, + psid
+
+ :param ipv4_net: IPv4 domain prefix.
+ :param ipv4_host: Destination IPv4 address.
+ :param ea_bit_len: EA bit length.
+ :param psid_len: PSID length.
+ :param psid: PSID.
+ :type ipv4_net: ipaddress.IPv4Network
+ :type ipv4_host: ipaddress.IPv4Address
+ :type ea_bit_len: int
+ :type psid_len: int
+ :type psid: int
+ :return: Number representing EA bit field of destination IPv6 address.
+ :rtype: int
+ """
+ v4_suffix_len = ipv4_net._max_prefixlen - ipv4_net.prefixlen
+ v4_suffix = ipv4_net.network_address._ip ^ ipv4_host._ip
+
+ if ipv4_net.prefixlen + ea_bit_len <= 32:
+ ea_bits = v4_suffix >> (v4_suffix_len - ea_bit_len)
+ return ea_bits
+ else:
+ q_len = ea_bit_len - v4_suffix_len
+ # p_bits = v4_suffix << q_len # option 1: psid right padded
+ p_bits = v4_suffix << psid_len # option 2: psid left padded
+ if q_len < psid_len:
+ raise Exception("invalid configuration: q_len < psid_len")
+ ea_bits = p_bits | psid
+ ea_bits <<= q_len - psid_len # option 2: psid left padded
+ return ea_bits
+
+ @staticmethod
+ def _make_interface_id(rule_net, dst_ip, ea_bit_len, psid):
+ """
+ _note_: if prefix or complete ip (<= 32), psid is 0
+
+ :param rule_net: IPv4 domain prefix.
+ :param dst_ip: Destination IPv4 address.
+ :param ea_bit_len: EA bit length.
+ :param psid: PSID.
+ :type rule_net: ipaddress.IPv4Network
+ :type dst_ip: ipaddress.IPv4Address
+ :type ea_bit_len: int
+ :type psid: int
+ :return: Number representing interface id field of destination IPv6
+ address.
+ :rtype: int
+ """
+ if rule_net.prefixlen + ea_bit_len < 32:
+ v4_suffix_len = rule_net._max_prefixlen - rule_net.prefixlen
+ v4_suffix = rule_net.network_address._ip ^ dst_ip._ip
+ ea_bits = v4_suffix >> (v4_suffix_len - ea_bit_len)
+ address = rule_net.network_address._ip >> v4_suffix_len
+ address <<= ea_bit_len
+ address |= ea_bits
+ address <<= 32 - rule_net.prefixlen - ea_bit_len
+ address <<= 16
+ # psid_field = 0
+ # address = address | psid_field
+ elif rule_net.prefixlen + ea_bit_len == 32:
+ address = dst_ip._ip << 16
+ # psid_field = 0
+ # address = address | psid_field
+ else:
+ address = dst_ip._ip << 16
+ address |= psid
+ return address
+
+ return address
+
+ @staticmethod
+ def compute_ipv6_map_destination_address(ipv4_pfx, ipv6_pfx, ea_bit_len,
+ psid_offset, psid_len, ipv4_dst,
+ dst_port):
+ """Compute IPv6 destination address from IPv4 address for MAP algorithm.
+ (RFC 7597)
+
+ | n bits | o bits | s bits | 128-n-o-s bits |
+ +--------------------+-----------+---------+-----------------------+
+ | Rule IPv6 prefix | EA bits |subnet ID| interface ID |
+ +--------------------+-----------+---------+-----------------------+
+ |<--- End-user IPv6 prefix --->|
+
+
+ :param ipv4_pfx: Domain IPv4 preffix.
+ :param ipv6_pfx: Domain IPv6 preffix.
+ :param ea_bit_len: Domain EA bits length.
+ :param psid_offset: Domain PSID offset.
+ :param psid_len: Domain PSID length.
+ :param ipv4_dst: Destination IPv4 address.
+ :param dst_port: Destination port number or ICMP ID.
+ :type ipv4_pfx: str
+ :type ipv6_pfx: str
+ :type ea_bit_len: int
+ :type psid_offset: int
+ :type psid_len: int
+ :type ipv4_dst: str
+ :type dst_port: int
+ :return: Computed IPv6 address.
+ :rtype: str
+ """
+ ipv6_net = ipaddress.ip_network(unicode(ipv6_pfx))
+ ipv4_net = ipaddress.ip_network(unicode(ipv4_pfx))
+ ipv4_host = ipaddress.ip_address(unicode(ipv4_dst))
+
+ ipv6_host_len = ipv6_net._max_prefixlen - ipv6_net.prefixlen
+ ipv4_host_len = ipv4_net._max_prefixlen - ipv4_net.prefixlen
+ end_user_v6_pfx_len = ipv6_net.prefixlen + ea_bit_len
+ psid = Map.get_psid_from_port(dst_port, psid_len, psid_offset)
+
+ rule_v6_pfx = ipv6_net.network_address._ip >> ipv6_host_len
+ ea_bits = Map._make_ea_bits(ipv4_net, ipv4_host, ea_bit_len, psid_len,
+ psid)
+ subnet_id = 0
+ interface_id = Map._make_interface_id(ipv4_net, ipv4_host, ea_bit_len,
+ psid)
+
+ address = rule_v6_pfx << ea_bit_len
+ address |= ea_bits # add EA bits
+
+ if end_user_v6_pfx_len > 64:
+ # If the End-user IPv6 prefix length is larger than 64,
+ # the most significant parts of the interface identifier are
+ # overwritten by the prefix.
+ mask = (2**128-1) >> end_user_v6_pfx_len
+ interface_id &= mask
+ address <<= (128 - end_user_v6_pfx_len)
+ address |= interface_id # add Interface ID bits
+
+ return str(ipaddress.ip_address(address))
Code Review / csit.git / blobdiff