2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * ip/ip4_source_check.c: IP v4 check source address (unicast RPF check)
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #include <vnet/ip/ip.h>
41 #include <vnet/fib/ip4_fib.h>
42 #include <vnet/fib/fib_urpf_list.h>
43 #include <vnet/dpo/load_balance.h>
47 * @brief IPv4 Unicast Source Check.
49 * This file contains the IPv4 interface unicast source check.
56 } ip4_source_check_trace_t;
58 static u8 * format_ip4_source_check_trace (u8 * s, va_list * va)
60 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
61 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
62 ip4_source_check_trace_t * t = va_arg (*va, ip4_source_check_trace_t *);
66 t->packet_data, sizeof (t->packet_data));
72 IP4_SOURCE_CHECK_NEXT_DROP,
73 IP4_SOURCE_CHECK_N_NEXT,
74 } ip4_source_check_next_t;
77 IP4_SOURCE_CHECK_REACHABLE_VIA_RX,
78 IP4_SOURCE_CHECK_REACHABLE_VIA_ANY,
79 } ip4_source_check_type_t;
83 } ip4_source_check_config_t;
86 ip4_source_check_inline (vlib_main_t * vm,
87 vlib_node_runtime_t * node,
89 ip4_source_check_type_t source_check_type)
91 u32 n_left_from, * from, * to_next;
93 vlib_node_runtime_t * error_node = vlib_node_get_runtime (vm, ip4_input_node.index);
95 from = vlib_frame_vector_args (frame);
96 n_left_from = frame->n_vectors;
97 next_index = node->cached_next_index;
99 if (node->flags & VLIB_NODE_FLAG_TRACE)
100 vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
102 sizeof (ip4_source_check_trace_t));
104 while (n_left_from > 0)
108 vlib_get_next_frame (vm, node, next_index,
109 to_next, n_left_to_next);
111 while (n_left_from >= 4 && n_left_to_next >= 2)
113 vlib_buffer_t * p0, * p1;
114 ip4_header_t * ip0, * ip1;
115 ip4_fib_mtrie_t * mtrie0, * mtrie1;
116 ip4_fib_mtrie_leaf_t leaf0, leaf1;
117 ip4_source_check_config_t * c0, * c1;
118 const load_balance_t * lb0, * lb1;
119 u32 pi0, next0, pass0, lb_index0;
120 u32 pi1, next1, pass1, lb_index1;
122 /* Prefetch next iteration. */
124 vlib_buffer_t * p2, * p3;
126 p2 = vlib_get_buffer (vm, from[2]);
127 p3 = vlib_get_buffer (vm, from[3]);
129 vlib_prefetch_buffer_header (p2, LOAD);
130 vlib_prefetch_buffer_header (p3, LOAD);
132 CLIB_PREFETCH (p2->data, sizeof (ip0[0]), LOAD);
133 CLIB_PREFETCH (p3->data, sizeof (ip1[0]), LOAD);
136 pi0 = to_next[0] = from[0];
137 pi1 = to_next[1] = from[1];
143 p0 = vlib_get_buffer (vm, pi0);
144 p1 = vlib_get_buffer (vm, pi1);
146 ip0 = vlib_buffer_get_current (p0);
147 ip1 = vlib_buffer_get_current (p1);
149 c0 = vnet_feature_next_with_data(vnet_buffer (p0)->sw_if_index[VLIB_RX] , &next0, p0, sizeof (c0[0]));
150 c1 = vnet_feature_next_with_data(vnet_buffer (p1)->sw_if_index[VLIB_RX] , &next1, p1, sizeof (c1[0]));
152 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
153 mtrie1 = &ip4_fib_get (c1->fib_index)->mtrie;
155 leaf0 = leaf1 = IP4_FIB_MTRIE_LEAF_ROOT;
157 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
158 leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 0);
160 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
161 leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 1);
163 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
164 leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 2);
166 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
167 leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 3);
169 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
170 lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
172 lb0 = load_balance_get(lb_index0);
173 lb1 = load_balance_get(lb_index1);
175 /* Pass multicast. */
176 pass0 = ip4_address_is_multicast (&ip0->src_address) || ip0->src_address.as_u32 == clib_host_to_net_u32(0xFFFFFFFF);
177 pass1 = ip4_address_is_multicast (&ip1->src_address) || ip1->src_address.as_u32 == clib_host_to_net_u32(0xFFFFFFFF);
179 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
181 pass0 |= fib_urpf_check(lb0->lb_urpf,
182 vnet_buffer (p0)->sw_if_index[VLIB_RX]);
183 pass1 |= fib_urpf_check(lb1->lb_urpf,
184 vnet_buffer (p1)->sw_if_index[VLIB_RX]);
188 pass0 |= fib_urpf_check_size(lb0->lb_urpf);
189 pass1 |= fib_urpf_check_size(lb1->lb_urpf);
191 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
192 next1 = (pass1 ? next1 : IP4_SOURCE_CHECK_NEXT_DROP);
194 p0->error = error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
195 p1->error = error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
197 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
198 to_next, n_left_to_next,
199 pi0, pi1, next0, next1);
202 while (n_left_from > 0 && n_left_to_next > 0)
206 ip4_fib_mtrie_t * mtrie0;
207 ip4_fib_mtrie_leaf_t leaf0;
208 ip4_source_check_config_t * c0;
209 u32 pi0, next0, pass0, lb_index0;
210 const load_balance_t * lb0;
219 p0 = vlib_get_buffer (vm, pi0);
220 ip0 = vlib_buffer_get_current (p0);
222 c0 = vnet_feature_next_with_data(vnet_buffer (p0)->sw_if_index[VLIB_RX] , &next0, p0, sizeof (c0[0]));
224 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
226 leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
228 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
230 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
232 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
234 leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
236 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
238 lb0 = load_balance_get(lb_index0);
240 /* Pass multicast. */
241 pass0 = ip4_address_is_multicast (&ip0->src_address) || ip0->src_address.as_u32 == clib_host_to_net_u32(0xFFFFFFFF);
243 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
245 pass0 |= fib_urpf_check(lb0->lb_urpf,
246 vnet_buffer (p0)->sw_if_index[VLIB_RX]);
250 pass0 |= fib_urpf_check_size(lb0->lb_urpf);
253 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
254 p0->error = error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
256 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
257 to_next, n_left_to_next,
261 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
264 return frame->n_vectors;
268 ip4_source_check_reachable_via_any (vlib_main_t * vm,
269 vlib_node_runtime_t * node,
270 vlib_frame_t * frame)
272 return ip4_source_check_inline (vm, node, frame, IP4_SOURCE_CHECK_REACHABLE_VIA_ANY);
276 ip4_source_check_reachable_via_rx (vlib_main_t * vm,
277 vlib_node_runtime_t * node,
278 vlib_frame_t * frame)
280 return ip4_source_check_inline (vm, node, frame, IP4_SOURCE_CHECK_REACHABLE_VIA_RX);
283 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_any) = {
284 .function = ip4_source_check_reachable_via_any,
285 .name = "ip4-source-check-via-any",
286 .vector_size = sizeof (u32),
288 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
290 [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
293 .format_buffer = format_ip4_header,
294 .format_trace = format_ip4_source_check_trace,
297 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_any,
298 ip4_source_check_reachable_via_any)
300 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_rx) = {
301 .function = ip4_source_check_reachable_via_rx,
302 .name = "ip4-source-check-via-rx",
303 .vector_size = sizeof (u32),
305 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
307 [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
310 .format_buffer = format_ip4_header,
311 .format_trace = format_ip4_source_check_trace,
314 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_rx,
315 ip4_source_check_reachable_via_rx)
317 static clib_error_t *
318 set_ip_source_check (vlib_main_t * vm,
319 unformat_input_t * input,
320 vlib_cli_command_t * cmd)
322 unformat_input_t _line_input, * line_input = &_line_input;
323 vnet_main_t * vnm = vnet_get_main();
324 ip4_main_t * im = &ip4_main;
325 clib_error_t * error = 0;
326 u32 sw_if_index, is_del;
327 ip4_source_check_config_t config;
328 char * feature_name = "ip4-source-check-via-rx";
333 if (! unformat_user (input, unformat_line_input, line_input))
336 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
338 if (unformat_user (line_input, unformat_vnet_sw_interface, vnm, &sw_if_index))
340 else if (unformat (line_input, "del"))
342 else if (unformat (line_input, "loose"))
343 feature_name = "ip4-source-check-via-any";
346 error = unformat_parse_error (line_input);
351 if (~0 == sw_if_index)
353 error = clib_error_return (0, "unknown interface `%U'",
354 format_unformat_error, line_input);
358 config.fib_index = im->fib_index_by_sw_if_index[sw_if_index];
359 vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index,
360 is_del == 0, &config, sizeof (config));
366 * This command adds the 'ip4-source-check-via-rx' graph node for
367 * a given interface. By adding the IPv4 source check graph node to
368 * an interface, the code verifies that the source address of incoming
369 * unicast packets are reachable over the incoming interface. Two flavours
370 * are supported (the default is strict):
371 * - loose: accept ingress packet if there is a route to reach the source
372 * - strict: accept ingress packet if it arrived on an interface which
373 * the route to the source uses. i.e. an interface that the source
378 * Example of graph node before range checking is enabled:
379 * @cliexstart{show vlib graph ip4-source-check-via-rx}
381 * ip4-source-check-via-rx error-drop [0]
384 * Example of how to enable unicast source checking on an interface:
385 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 loose}
387 * Example of graph node after range checking is enabled:
388 * @cliexstart{show vlib graph ip4-source-check-via-rx}
390 * ip4-source-check-via-rx error-drop [0] ip4-input-no-checksum
391 * ip4-source-and-port-range- ip4-input
394 * Example of how to display the feature enabed on an interface:
395 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
396 * IP feature paths configured on GigabitEthernet2/0/0...
399 * ip4-source-check-via-rx
403 * ip4-lookup-multicast
418 * Example of how to disable unicast source checking on an interface:
419 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 del}
423 VLIB_CLI_COMMAND (set_interface_ip_source_check_command, static) = {
424 .path = "set interface ip source-check",
425 .function = set_ip_source_check,
426 .short_help = "set interface ip source-check <interface> [strict|loose] [del]",
430 static clib_error_t *
431 ip_source_check_accept (vlib_main_t * vm,
432 unformat_input_t * input,
433 vlib_cli_command_t * cmd)
435 unformat_input_t _line_input, * line_input = &_line_input;
437 .fp_proto = FIB_PROTOCOL_IP4,
439 clib_error_t * error = NULL;
440 u32 table_id, is_add, fib_index;
445 /* Get a line of input. */
446 if (! unformat_user (input, unformat_line_input, line_input))
449 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
451 if (unformat (line_input, "table %d", &table_id))
453 else if (unformat (line_input, "del"))
455 else if (unformat (line_input, "add"))
457 else if (unformat (line_input, "%U/%d",
458 unformat_ip4_address,
461 pfx.fp_proto = FIB_PROTOCOL_IP4;
464 error = unformat_parse_error (line_input);
471 fib_index = fib_table_id_find_fib_index(pfx.fp_proto, table_id);
474 error = clib_error_return (0,
475 "Nonexistent table id %d",
487 fib_table_entry_special_add(fib_index,
489 FIB_SOURCE_URPF_EXEMPT,
495 fib_table_entry_special_remove(fib_index,
497 FIB_SOURCE_URPF_EXEMPT);
505 * Add an exemption for a prefix to pass the Unicast Reverse Path
506 * Forwarding (uRPF) loose check. This is for testing purposes only.
507 * If the '<em>table</em>' is not enter it is defaulted to 0. Default
508 * is to '<em>add</em>'. VPP always performs a loose uRPF check for
512 * Example of how to add a uRPF exception to a FIB table to pass the
514 * @cliexcmd{ip urpf-accept table 7 add}
517 VLIB_CLI_COMMAND (ip_source_check_accept_command, static) = {
518 .path = "ip urpf-accept",
519 .function = ip_source_check_accept,
520 .short_help = "ip urpf-accept [table <table-id>] [add|del]",
525 /* Dummy init function to get us linked in. */
526 clib_error_t * ip4_source_check_init (vlib_main_t * vm)
529 VLIB_INIT_FUNCTION (ip4_source_check_init);