| Neale Ranns | bf55e99 | 2018-10-04 06:40:30 -0700 | [diff] [blame] | 1 | #!/usr/bin/env python3 |
| 2 | |
| 3 | import unittest |
| 4 | |
| 5 | from framework import VppTestCase, VppTestRunner |
| 6 | |
| 7 | from scapy.layers.inet import IP, TCP |
| 8 | from scapy.layers.inet6 import IPv6 |
| 9 | from scapy.layers.l2 import Ether |
| 10 | from scapy.packet import Raw |
| 11 | |
| 12 | |
| 13 | class TestMSSClamp(VppTestCase): |
| 14 | """ TCP MSS Clamping Test Case """ |
| 15 | |
| 16 | def setUp(self): |
| 17 | super(TestMSSClamp, self).setUp() |
| 18 | |
| 19 | # create 2 pg interfaces |
| 20 | self.create_pg_interfaces(range(2)) |
| 21 | |
| 22 | for i in self.pg_interfaces: |
| 23 | i.admin_up() |
| 24 | i.config_ip4() |
| 25 | i.resolve_arp() |
| 26 | i.config_ip6() |
| 27 | i.resolve_ndp() |
| 28 | |
| 29 | def tearDown(self): |
| 30 | for i in self.pg_interfaces: |
| 31 | i.unconfig_ip4() |
| 32 | i.unconfig_ip6() |
| 33 | i.admin_down() |
| 34 | super(TestMSSClamp, self).tearDown() |
| 35 | |
| 36 | def verify_pkt(self, rx, expected_mss): |
| 37 | # check that the MSS size equals the expected value |
| 38 | # and the IP and TCP checksums are correct |
| 39 | tcp = rx[TCP] |
| 40 | tcp_csum = tcp.chksum |
| 41 | del tcp.chksum |
| 42 | ip_csum = 0 |
| 43 | if (rx.haslayer(IP)): |
| 44 | ip_csum = rx[IP].chksum |
| 45 | del rx[IP].chksum |
| 46 | |
| 47 | opt = tcp.options |
| 48 | self.assertEqual(opt[0][0], 'MSS') |
| 49 | self.assertEqual(opt[0][1], expected_mss) |
| 50 | # recalculate checksums |
| 51 | rx = rx.__class__(bytes(rx)) |
| 52 | tcp = rx[TCP] |
| 53 | self.assertEqual(tcp_csum, tcp.chksum) |
| 54 | if (rx.haslayer(IP)): |
| 55 | self.assertEqual(ip_csum, rx[IP].chksum) |
| 56 | |
| 57 | def send_and_verify_ip4(self, src_pg, dst_pg, mss, expected_mss): |
| 58 | # IPv4 TCP packet with the requested MSS option. |
| 59 | # from a host on src_pg to a host on dst_pg. |
| 60 | p = (Ether(dst=src_pg.local_mac, |
| 61 | src=src_pg.remote_mac) / |
| 62 | IP(src=src_pg.remote_ip4, |
| 63 | dst=dst_pg.remote_ip4) / |
| 64 | TCP(sport=1234, dport=1234, |
| 65 | flags="S", |
| 66 | options=[('MSS', (mss)), ('EOL', None)]) / |
| 67 | Raw('\xa5' * 100)) |
| 68 | |
| 69 | rxs = self.send_and_expect(src_pg, p * 65, dst_pg) |
| 70 | |
| 71 | for rx in rxs: |
| 72 | self.verify_pkt(rx, expected_mss) |
| 73 | |
| 74 | def send_and_verify_ip6(self, src_pg, dst_pg, mss, expected_mss): |
| 75 | # |
| 76 | # IPv6 TCP packet with the requested MSS option. |
| 77 | # from a host on src_pg to a host on dst_pg. |
| 78 | # |
| 79 | p = (Ether(dst=src_pg.local_mac, |
| 80 | src=src_pg.remote_mac) / |
| 81 | IPv6(src=src_pg.remote_ip6, |
| 82 | dst=dst_pg.remote_ip6) / |
| 83 | TCP(sport=1234, dport=1234, |
| 84 | flags="S", |
| 85 | options=[('MSS', (mss)), ('EOL', None)]) / |
| 86 | Raw('\xa5' * 100)) |
| 87 | |
| 88 | rxs = self.send_and_expect(src_pg, p * 65, dst_pg) |
| 89 | |
| 90 | for rx in rxs: |
| 91 | self.verify_pkt(rx, expected_mss) |
| 92 | |
| 93 | def test_tcp_mss_clamping_ip4_tx(self): |
| 94 | """ IP4 TCP MSS Clamping TX """ |
| 95 | |
| 96 | # enable the TCP MSS clamping feature to lower the MSS to 1424. |
| 97 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 98 | ipv4_mss=1424, ipv6_mss=0, |
| 99 | ipv4_direction=3, ipv6_direction=0) |
| 100 | |
| 101 | # Verify that the feature is enabled. |
| 102 | rv, reply = self.vapi.mss_clamp_get(sw_if_index=self.pg1.sw_if_index) |
| 103 | self.assertEqual(reply[0].ipv4_mss, 1424) |
| 104 | self.assertEqual(reply[0].ipv4_direction, 3) |
| 105 | |
| 106 | # Send syn packets and verify that the MSS value is lowered. |
| 107 | self.send_and_verify_ip4(self.pg0, self.pg1, 1460, 1424) |
| 108 | |
| 109 | # check the stats |
| 110 | stats = self.statistics.get_counter( |
| 111 | '/err/tcp-mss-clamping-ip4-out/clamped') |
| 112 | self.assertEqual(sum(stats), 65) |
| 113 | |
| 114 | # Send syn packets with small enough MSS values and verify they are |
| 115 | # unchanged. |
| 116 | self.send_and_verify_ip4(self.pg0, self.pg1, 1400, 1400) |
| 117 | |
| 118 | # enable the the feature only in TX direction |
| 119 | # and change the max MSS value |
| 120 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 121 | ipv4_mss=1420, ipv6_mss=0, |
| 122 | ipv4_direction=2, ipv6_direction=0) |
| 123 | |
| 124 | # Send syn packets and verify that the MSS value is lowered. |
| 125 | self.send_and_verify_ip4(self.pg0, self.pg1, 1460, 1420) |
| 126 | |
| 127 | # enable the the feature only in RX direction |
| 128 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 129 | ipv4_mss=1424, ipv6_mss=0, |
| 130 | ipv4_direction=1, ipv6_direction=0) |
| 131 | |
| 132 | # Send the packets again and ensure they are unchanged. |
| 133 | self.send_and_verify_ip4(self.pg0, self.pg1, 1460, 1460) |
| 134 | |
| 135 | # disable the feature |
| 136 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 137 | ipv4_mss=0, ipv6_mss=0, |
| 138 | ipv4_direction=0, ipv6_direction=0) |
| 139 | |
| 140 | # Send the packets again and ensure they are unchanged. |
| 141 | self.send_and_verify_ip4(self.pg0, self.pg1, 1460, 1460) |
| 142 | |
| 143 | def test_tcp_mss_clamping_ip4_rx(self): |
| 144 | """ IP4 TCP MSS Clamping RX """ |
| 145 | |
| 146 | # enable the TCP MSS clamping feature to lower the MSS to 1424. |
| 147 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 148 | ipv4_mss=1424, ipv6_mss=0, |
| 149 | ipv4_direction=3, ipv6_direction=0) |
| 150 | |
| 151 | # Verify that the feature is enabled. |
| 152 | rv, reply = self.vapi.mss_clamp_get(sw_if_index=self.pg1.sw_if_index) |
| 153 | self.assertEqual(reply[0].ipv4_mss, 1424) |
| 154 | self.assertEqual(reply[0].ipv4_direction, 3) |
| 155 | |
| 156 | # Send syn packets and verify that the MSS value is lowered. |
| 157 | self.send_and_verify_ip4(self.pg1, self.pg0, 1460, 1424) |
| 158 | |
| 159 | # check the stats |
| 160 | stats = self.statistics.get_counter( |
| 161 | '/err/tcp-mss-clamping-ip4-in/clamped') |
| 162 | self.assertEqual(sum(stats), 65) |
| 163 | |
| 164 | # Send syn packets with small enough MSS values and verify they are |
| 165 | # unchanged. |
| 166 | self.send_and_verify_ip4(self.pg1, self.pg0, 1400, 1400) |
| 167 | |
| 168 | # enable the the feature only in RX direction |
| 169 | # and change the max MSS value |
| 170 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 171 | ipv4_mss=1420, ipv6_mss=0, |
| 172 | ipv4_direction=1, ipv6_direction=0) |
| 173 | |
| 174 | # Send syn packets and verify that the MSS value is lowered. |
| 175 | self.send_and_verify_ip4(self.pg1, self.pg0, 1460, 1420) |
| 176 | |
| 177 | # enable the the feature only in TX direction |
| 178 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 179 | ipv4_mss=1424, ipv6_mss=0, |
| 180 | ipv4_direction=2, ipv6_direction=0) |
| 181 | |
| 182 | # Send the packets again and ensure they are unchanged. |
| 183 | self.send_and_verify_ip4(self.pg1, self.pg0, 1460, 1460) |
| 184 | |
| 185 | # disable the feature |
| 186 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 187 | ipv4_mss=0, ipv6_mss=0, |
| 188 | ipv4_direction=0, ipv6_direction=0) |
| 189 | |
| 190 | # Send the packets again and ensure they are unchanged. |
| 191 | self.send_and_verify_ip4(self.pg1, self.pg0, 1460, 1460) |
| 192 | |
| 193 | def test_tcp_mss_clamping_ip6_tx(self): |
| 194 | """ IP6 TCP MSS Clamping TX """ |
| 195 | |
| 196 | # enable the TCP MSS clamping feature to lower the MSS to 1424. |
| 197 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 198 | ipv4_mss=0, ipv6_mss=1424, |
| 199 | ipv4_direction=0, ipv6_direction=3) |
| 200 | |
| 201 | # Verify that the feature is enabled. |
| 202 | rv, reply = self.vapi.mss_clamp_get(sw_if_index=self.pg1.sw_if_index) |
| 203 | self.assertEqual(reply[0].ipv6_mss, 1424) |
| 204 | self.assertEqual(reply[0].ipv6_direction, 3) |
| 205 | |
| 206 | # Send syn packets and verify that the MSS value is lowered. |
| 207 | self.send_and_verify_ip6(self.pg0, self.pg1, 1460, 1424) |
| 208 | |
| 209 | # check the stats |
| 210 | stats = self.statistics.get_counter( |
| 211 | '/err/tcp-mss-clamping-ip6-out/clamped') |
| 212 | self.assertEqual(sum(stats), 65) |
| 213 | |
| 214 | # Send syn packets with small enough MSS values and verify they are |
| 215 | # unchanged. |
| 216 | self.send_and_verify_ip6(self.pg0, self.pg1, 1400, 1400) |
| 217 | |
| 218 | # enable the the feature only in TX direction |
| 219 | # and change the max MSS value |
| 220 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 221 | ipv4_mss=0, ipv6_mss=1420, |
| 222 | ipv4_direction=0, ipv6_direction=2) |
| 223 | |
| 224 | # Send syn packets and verify that the MSS value is lowered. |
| 225 | self.send_and_verify_ip6(self.pg0, self.pg1, 1460, 1420) |
| 226 | |
| 227 | # enable the the feature only in RX direction |
| 228 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 229 | ipv4_mss=0, ipv6_mss=1424, |
| 230 | ipv4_direction=0, ipv6_direction=1) |
| 231 | |
| 232 | # Send the packets again and ensure they are unchanged. |
| 233 | self.send_and_verify_ip6(self.pg0, self.pg1, 1460, 1460) |
| 234 | |
| 235 | # disable the feature |
| 236 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 237 | ipv4_mss=0, ipv6_mss=0, |
| 238 | ipv4_direction=0, ipv6_direction=0) |
| 239 | |
| 240 | # Send the packets again and ensure they are unchanged. |
| 241 | self.send_and_verify_ip6(self.pg0, self.pg1, 1460, 1460) |
| 242 | |
| 243 | def test_tcp_mss_clamping_ip6_rx(self): |
| 244 | """ IP6 TCP MSS Clamping RX """ |
| 245 | |
| 246 | # enable the TCP MSS clamping feature to lower the MSS to 1424. |
| 247 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 248 | ipv4_mss=0, ipv6_mss=1424, |
| 249 | ipv4_direction=0, ipv6_direction=3) |
| 250 | |
| 251 | # Verify that the feature is enabled. |
| 252 | rv, reply = self.vapi.mss_clamp_get(sw_if_index=self.pg1.sw_if_index) |
| 253 | self.assertEqual(reply[0].ipv6_mss, 1424) |
| 254 | self.assertEqual(reply[0].ipv6_direction, 3) |
| 255 | |
| 256 | # Send syn packets and verify that the MSS value is lowered. |
| 257 | self.send_and_verify_ip6(self.pg1, self.pg0, 1460, 1424) |
| 258 | |
| 259 | # check the stats |
| 260 | stats = self.statistics.get_counter( |
| 261 | '/err/tcp-mss-clamping-ip6-in/clamped') |
| 262 | self.assertEqual(sum(stats), 65) |
| 263 | |
| 264 | # Send syn packets with small enough MSS values and verify they are |
| 265 | # unchanged. |
| 266 | self.send_and_verify_ip6(self.pg1, self.pg0, 1400, 1400) |
| 267 | |
| 268 | # enable the the feature only in RX direction |
| 269 | # and change the max MSS value |
| 270 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 271 | ipv4_mss=0, ipv6_mss=1420, |
| 272 | ipv4_direction=0, ipv6_direction=1) |
| 273 | |
| 274 | # Send syn packets and verify that the MSS value is lowered. |
| 275 | self.send_and_verify_ip6(self.pg1, self.pg0, 1460, 1420) |
| 276 | |
| 277 | # enable the the feature only in TX direction |
| 278 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 279 | ipv4_mss=0, ipv6_mss=1424, |
| 280 | ipv4_direction=0, ipv6_direction=2) |
| 281 | |
| 282 | # Send the packets again and ensure they are unchanged. |
| 283 | self.send_and_verify_ip6(self.pg1, self.pg0, 1460, 1460) |
| 284 | |
| 285 | # disable the feature |
| 286 | self.vapi.mss_clamp_enable_disable(self.pg1.sw_if_index, |
| 287 | ipv4_mss=0, ipv6_mss=0, |
| 288 | ipv4_direction=0, ipv6_direction=0) |
| 289 | |
| 290 | # Send the packets again and ensure they are unchanged. |
| 291 | self.send_and_verify_ip6(self.pg1, self.pg0, 1460, 1460) |
| 292 | |
| 293 | |
| 294 | if __name__ == '__main__': |
| 295 | unittest.main(testRunner=VppTestRunner) |