#!/usr/bin/env python3 import unittest import socket from scapy.packet import Raw from scapy.layers.l2 import Ether from scapy.layers.inet import IP, UDP from scapy.layers.inet6 import IPv6 from vpp_papi import VppEnum from vpp_ip_route import VppRoutePath from framework import VppTestCase class TestIpSessionRedirect(VppTestCase): """IP session redirect Test Case""" @classmethod def setUpClass(cls): super(TestIpSessionRedirect, cls).setUpClass() itfs = cls.create_pg_interfaces(range(3)) for itf in itfs: itf.admin_up() itf.config_ip4() itf.resolve_arp() itf.config_ip6() itf.resolve_ndp() def __build_mask(self, ip, src_port, match_n_vectors): # UDP: udp src port (2 bytes) udp = src_port.to_bytes(2, byteorder="big") match = ip + udp # skip the remainer match += b"\x00" * (match_n_vectors * 16 - len(match)) return match def build_mask4(self, proto, src_ip, src_port): proto = proto.to_bytes(1, byteorder="big") # IP: skip 9 bytes | proto (1 byte) | skip checksum (2 bytes) | src IP # (4 bytes) | skip dst IP (4 bytes) ip = b"\x00" * 9 + proto + b"\x00" * 2 + src_ip + b"\x00" * 4 return self.__build_mask(ip, src_port, 2) def build_mask6(self, proto, src_ip, src_port): nh = proto.to_bytes(1, byteorder="big") # IPv6: skip 6 bytes | nh (1 byte) | skip hl (1 byte) | src IP (16 # bytes) | skip dst IP (16 bytes) ip = b"\x00" * 6 + nh + b"\x00" + src_ip + b"\x00" * 16 return self.__build_mask(ip, src_port, 4) def build_match(self, src_ip, src_port, is_ip6): if is_ip6: return self.build_mask6( 0x11, socket.inet_pton(socket.AF_INET6, src_ip), src_port ) else: return self.build_mask4( 0x11, socket.inet_pton(socket.AF_INET, src_ip), src_port ) def create_table(self, is_ip6): if is_ip6: mask = self.build_mask6(0xFF, b"\xff" * 16, 0xFFFF) match_n_vectors = 4 else: mask = self.build_mask4(0xFF, b"\xff" * 4, 0xFFFF) match_n_vectors = 2 r = self.vapi.classify_add_del_table( is_add=True, match_n_vectors=match_n_vectors, miss_next_index=0, # drop current_data_flag=1, # match on current header (ip) mask_len=len(mask), mask=mask, ) return r.new_table_index def __test_redirect(self, sport, dport, is_punt, is_ip6): if is_ip6: af = VppEnum.vl_api_address_family_t.ADDRESS_IP6 nh1 = self.pg1.remote_ip6 nh2 = self.pg2.remote_ip6 # note: nh3 is using a v4 adj to forward ipv6 packets nh3 = self.pg2.remote_ip4 src = self.pg0.remote_ip6 dst = self.pg0.local_ip6 IP46 = IPv6 proto = VppEnum.vl_api_fib_path_nh_proto_t.FIB_API_PATH_NH_PROTO_IP6 else: af = VppEnum.vl_api_address_family_t.ADDRESS_IP4 nh1 = self.pg1.remote_ip4 nh2 = self.pg2.remote_ip4 # note: nh3 is using a v6 adj to forward ipv4 packets nh3 = self.pg2.remote_ip6 src = self.pg0.remote_ip4 dst = self.pg0.local_ip4 IP46 = IP proto = VppEnum.vl_api_fib_path_nh_proto_t.FIB_API_PATH_NH_PROTO_IP4 if is_punt: # punt udp packets to dport self.vapi.set_punt( is_add=1, punt={ "type": VppEnum.vl_api_punt_type_t.PUNT_API_TYPE_L4, "punt": { "l4": { "af": af, "protocol": VppEnum.vl_api_ip_proto_t.IP_API_PROTO_UDP, "port": dport, } }, }, ) pkts = [ ( Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) / IP46(src=src, dst=dst) / UDP(sport=sport, dport=dport) / Raw("\x17" * 100) ) ] * 2 # create table and configure ACL table_index = self.create_table(is_ip6) ip4_tid, ip6_tid = ( (0xFFFFFFFF, table_index) if is_ip6 else (table_index, 0xFFFFFFFF) ) if is_punt: self.vapi.punt_acl_add_del( is_add=1, ip4_table_index=ip4_tid, ip6_table_index=ip6_tid ) else: self.vapi.input_acl_set_interface( is_add=1, ip4_table_index=ip4_tid, ip6_table_index=ip6_tid, l2_table_index=0xFFFFFFFF, sw_if_index=self.pg0.sw_if_index, ) # add a session redirect rule but not matching the stream: expect to # drop paths = [VppRoutePath(nh1, 0xFFFFFFFF).encode()] match1 = self.build_match(src, sport + 10, is_ip6) r = self.vapi.ip_session_redirect_add_v2( table_index=table_index, match_len=len(match1), match=match1, is_punt=is_punt, n_paths=1, paths=paths, ) self.send_and_assert_no_replies(self.pg0, pkts) # redirect a session matching the stream: expect to pass match2 = self.build_match(src, sport, is_ip6) self.vapi.ip_session_redirect_add_v2( table_index=table_index, match_len=len(match2), match=match2, is_punt=is_punt, n_paths=1, paths=paths, ) self.send_and_expect_only(self.pg0, pkts, self.pg1) # update the matching entry so it redirects to pg2 # nh3 is using a v4 adj for v6 and vice-versa, hence we must specify # the payload proto with v2 api paths = [VppRoutePath(nh3, 0xFFFFFFFF).encode()] self.vapi.ip_session_redirect_add_v2( table_index=table_index, match_len=len(match2), match=match2, is_punt=is_punt, n_paths=1, paths=paths, proto=proto, ) self.send_and_expect_only(self.pg0, pkts, self.pg2) # we still have only 2 sessions, not 3 t = self.vapi.classify_table_info(table_id=table_index) self.assertEqual(t.active_sessions, 2) # cleanup self.vapi.ip_session_redirect_del(table_index, len(match2), match2) self.vapi.ip_session_redirect_del(table_index, len(match1), match1) t = self.vapi.classify_table_info(table_id=table_index) self.assertEqual(t.active_sessions, 0) if is_punt: self.vapi.punt_acl_add_del( is_add=0, ip4_table_index=ip4_tid, ip6_table_index=ip6_tid ) else: self.vapi.input_acl_set_interface( is_add=0, ip4_table_index=ip4_tid, ip6_table_index=ip6_tid, l2_table_index=0xFFFFFFFF, sw_if_index=self.pg0.sw_if_index, ) def test_punt_redirect_ipv4(self): """IPv4 punt session redirect test""" return self.__test_redirect(sport=6754, dport=17923, is_punt=True, is_ip6=False) def test_punt_redirect_ipv6(self): """IPv6 punt session redirect test""" return self.__test_redirect(sport=28447, dport=4035, is_punt=True, is_ip6=True) def test_redirect_ipv4(self): """IPv4 session redirect test""" return self.__test_redirect(sport=834, dport=1267, is_punt=False, is_ip6=False) def test_redirect_ipv6(self): """IPv6 session redirect test""" return self.__test_redirect(sport=9999, dport=32768, is_punt=False, is_ip6=True) if __name__ == "__main__": unittest.main(testRunner=VppTestRunner)