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.
57 } ip4_source_check_trace_t;
60 format_ip4_source_check_trace (u8 * s, va_list * va)
62 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
63 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
64 ip4_source_check_trace_t *t = va_arg (*va, ip4_source_check_trace_t *);
67 format_ip4_header, t->packet_data, sizeof (t->packet_data));
74 IP4_SOURCE_CHECK_NEXT_DROP,
75 IP4_SOURCE_CHECK_N_NEXT,
76 } ip4_source_check_next_t;
80 IP4_SOURCE_CHECK_REACHABLE_VIA_RX,
81 IP4_SOURCE_CHECK_REACHABLE_VIA_ANY,
82 } ip4_source_check_type_t;
87 } ip4_source_check_config_t;
90 ip4_source_check_inline (vlib_main_t * vm,
91 vlib_node_runtime_t * node,
93 ip4_source_check_type_t source_check_type)
95 u32 n_left_from, *from, *to_next;
97 vlib_node_runtime_t *error_node =
98 vlib_node_get_runtime (vm, ip4_input_node.index);
100 from = vlib_frame_vector_args (frame);
101 n_left_from = frame->n_vectors;
102 next_index = node->cached_next_index;
104 if (node->flags & VLIB_NODE_FLAG_TRACE)
105 vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
107 sizeof (ip4_source_check_trace_t));
109 while (n_left_from > 0)
113 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
115 while (n_left_from >= 4 && n_left_to_next >= 2)
117 vlib_buffer_t *p0, *p1;
118 ip4_header_t *ip0, *ip1;
119 ip4_fib_mtrie_t *mtrie0, *mtrie1;
120 ip4_fib_mtrie_leaf_t leaf0, leaf1;
121 ip4_source_check_config_t *c0, *c1;
122 const load_balance_t *lb0, *lb1;
123 u32 pi0, next0, pass0, lb_index0;
124 u32 pi1, next1, pass1, lb_index1;
126 /* Prefetch next iteration. */
128 vlib_buffer_t *p2, *p3;
130 p2 = vlib_get_buffer (vm, from[2]);
131 p3 = vlib_get_buffer (vm, from[3]);
133 vlib_prefetch_buffer_header (p2, LOAD);
134 vlib_prefetch_buffer_header (p3, LOAD);
136 CLIB_PREFETCH (p2->data, sizeof (ip0[0]), LOAD);
137 CLIB_PREFETCH (p3->data, sizeof (ip1[0]), LOAD);
140 pi0 = to_next[0] = from[0];
141 pi1 = to_next[1] = from[1];
147 p0 = vlib_get_buffer (vm, pi0);
148 p1 = vlib_get_buffer (vm, pi1);
150 ip0 = vlib_buffer_get_current (p0);
151 ip1 = vlib_buffer_get_current (p1);
153 c0 = vnet_feature_next_with_data (&next0, p0, sizeof (c0[0]));
154 c1 = vnet_feature_next_with_data (&next1, p1, sizeof (c1[0]));
156 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
157 mtrie1 = &ip4_fib_get (c1->fib_index)->mtrie;
159 leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
160 leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, &ip1->src_address);
163 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
165 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 2);
168 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
170 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 3);
172 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
173 lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
175 lb0 = load_balance_get (lb_index0);
176 lb1 = load_balance_get (lb_index1);
178 /* Pass multicast. */
179 pass0 = ip4_address_is_multicast (&ip0->src_address)
180 || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
181 pass1 = ip4_address_is_multicast (&ip1->src_address)
182 || ip1->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
184 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
186 pass0 |= fib_urpf_check (lb0->lb_urpf,
187 vnet_buffer (p0)->sw_if_index
190 fib_urpf_check (lb1->lb_urpf,
191 vnet_buffer (p1)->sw_if_index[VLIB_RX]);
195 pass0 |= fib_urpf_check_size (lb0->lb_urpf);
196 pass1 |= fib_urpf_check_size (lb1->lb_urpf);
198 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
199 next1 = (pass1 ? next1 : IP4_SOURCE_CHECK_NEXT_DROP);
202 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
204 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
206 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
207 to_next, n_left_to_next,
208 pi0, pi1, next0, next1);
211 while (n_left_from > 0 && n_left_to_next > 0)
215 ip4_fib_mtrie_t *mtrie0;
216 ip4_fib_mtrie_leaf_t leaf0;
217 ip4_source_check_config_t *c0;
218 u32 pi0, next0, pass0, lb_index0;
219 const load_balance_t *lb0;
228 p0 = vlib_get_buffer (vm, pi0);
229 ip0 = vlib_buffer_get_current (p0);
231 c0 = vnet_feature_next_with_data (&next0, p0, sizeof (c0[0]));
233 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
235 leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
238 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
241 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
243 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
245 lb0 = load_balance_get (lb_index0);
247 /* Pass multicast. */
248 pass0 = ip4_address_is_multicast (&ip0->src_address)
249 || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
251 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
253 pass0 |= fib_urpf_check (lb0->lb_urpf,
254 vnet_buffer (p0)->sw_if_index
259 pass0 |= fib_urpf_check_size (lb0->lb_urpf);
262 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
264 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
266 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
267 to_next, n_left_to_next,
271 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
274 return frame->n_vectors;
278 ip4_source_check_reachable_via_any (vlib_main_t * vm,
279 vlib_node_runtime_t * node,
280 vlib_frame_t * frame)
282 return ip4_source_check_inline (vm, node, frame,
283 IP4_SOURCE_CHECK_REACHABLE_VIA_ANY);
287 ip4_source_check_reachable_via_rx (vlib_main_t * vm,
288 vlib_node_runtime_t * node,
289 vlib_frame_t * frame)
291 return ip4_source_check_inline (vm, node, frame,
292 IP4_SOURCE_CHECK_REACHABLE_VIA_RX);
296 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_any) = {
297 .function = ip4_source_check_reachable_via_any,
298 .name = "ip4-source-check-via-any",
299 .vector_size = sizeof (u32),
301 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
303 [IP4_SOURCE_CHECK_NEXT_DROP] = "ip4-drop",
306 .format_buffer = format_ip4_header,
307 .format_trace = format_ip4_source_check_trace,
311 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_any,
312 ip4_source_check_reachable_via_any);
315 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_rx) = {
316 .function = ip4_source_check_reachable_via_rx,
317 .name = "ip4-source-check-via-rx",
318 .vector_size = sizeof (u32),
320 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
322 [IP4_SOURCE_CHECK_NEXT_DROP] = "ip4-drop",
325 .format_buffer = format_ip4_header,
326 .format_trace = format_ip4_source_check_trace,
330 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_rx,
331 ip4_source_check_reachable_via_rx);
333 static clib_error_t *
334 set_ip_source_check (vlib_main_t * vm,
335 unformat_input_t * input, vlib_cli_command_t * cmd)
337 unformat_input_t _line_input, *line_input = &_line_input;
338 vnet_main_t *vnm = vnet_get_main ();
339 ip4_main_t *im = &ip4_main;
340 clib_error_t *error = 0;
341 u32 sw_if_index, is_del;
342 ip4_source_check_config_t config;
343 char *feature_name = "ip4-source-check-via-rx";
348 if (!unformat_user (input, unformat_line_input, line_input))
351 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
354 (line_input, unformat_vnet_sw_interface, vnm, &sw_if_index))
356 else if (unformat (line_input, "del"))
358 else if (unformat (line_input, "loose"))
359 feature_name = "ip4-source-check-via-any";
362 error = unformat_parse_error (line_input);
367 if (~0 == sw_if_index)
369 error = clib_error_return (0, "unknown interface `%U'",
370 format_unformat_error, line_input);
374 config.fib_index = im->fib_index_by_sw_if_index[sw_if_index];
375 vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index,
376 is_del == 0, &config, sizeof (config));
378 unformat_free (line_input);
384 * This command adds the 'ip4-source-check-via-rx' graph node for
385 * a given interface. By adding the IPv4 source check graph node to
386 * an interface, the code verifies that the source address of incoming
387 * unicast packets are reachable over the incoming interface. Two flavours
388 * are supported (the default is strict):
389 * - loose: accept ingress packet if there is a route to reach the source
390 * - strict: accept ingress packet if it arrived on an interface which
391 * the route to the source uses. i.e. an interface that the source
396 * Example of graph node before range checking is enabled:
397 * @cliexstart{show vlib graph ip4-source-check-via-rx}
399 * ip4-source-check-via-rx ip4-drop [0]
402 * Example of how to enable unicast source checking on an interface:
403 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 loose}
405 * Example of graph node after range checking is enabled:
406 * @cliexstart{show vlib graph ip4-source-check-via-rx}
408 * ip4-source-check-via-rx ip4-drop [0] ip4-input-no-checksum
409 * ip4-source-and-port-range- ip4-input
412 * Example of how to display the feature enabed on an interface:
413 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
414 * IP feature paths configured on GigabitEthernet2/0/0...
417 * ip4-source-check-via-rx
421 * ip4-lookup-multicast
436 * Example of how to disable unicast source checking on an interface:
437 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 del}
441 VLIB_CLI_COMMAND (set_interface_ip_source_check_command, static) = {
442 .path = "set interface ip source-check",
443 .function = set_ip_source_check,
444 .short_help = "set interface ip source-check <interface> [strict|loose] [del]",
448 static clib_error_t *
449 ip_source_check_accept (vlib_main_t * vm,
450 unformat_input_t * input, vlib_cli_command_t * cmd)
452 unformat_input_t _line_input, *line_input = &_line_input;
454 .fp_proto = FIB_PROTOCOL_IP4,
456 clib_error_t *error = NULL;
457 u32 table_id, is_add, fib_index;
462 /* Get a line of input. */
463 if (!unformat_user (input, unformat_line_input, line_input))
466 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
468 if (unformat (line_input, "table %d", &table_id))
470 else if (unformat (line_input, "del"))
472 else if (unformat (line_input, "add"))
474 else if (unformat (line_input, "%U/%d",
475 unformat_ip4_address, &pfx.fp_addr.ip4, &pfx.fp_len))
476 pfx.fp_proto = FIB_PROTOCOL_IP4;
479 error = unformat_parse_error (line_input);
486 fib_index = fib_table_find (pfx.fp_proto, table_id);
489 error = clib_error_return (0, "Nonexistent table id %d", table_id);
500 fib_table_entry_special_add (fib_index,
502 FIB_SOURCE_URPF_EXEMPT,
503 FIB_ENTRY_FLAG_DROP);
507 fib_table_entry_special_remove (fib_index,
508 &pfx, FIB_SOURCE_URPF_EXEMPT);
512 unformat_free (line_input);
518 * Add an exemption for a prefix to pass the Unicast Reverse Path
519 * Forwarding (uRPF) loose check. This is for testing purposes only.
520 * If the '<em>table</em>' is not enter it is defaulted to 0. Default
521 * is to '<em>add</em>'. VPP always performs a loose uRPF check for
525 * Example of how to add a uRPF exception to a FIB table to pass the
527 * @cliexcmd{ip urpf-accept table 7 add}
530 VLIB_CLI_COMMAND (ip_source_check_accept_command, static) = {
531 .path = "ip urpf-accept",
532 .function = ip_source_check_accept,
533 .short_help = "ip urpf-accept [table <table-id>] [add|del]",
538 /* Dummy init function to get us linked in. */
540 ip4_source_check_init (vlib_main_t * vm)
545 VLIB_INIT_FUNCTION (ip4_source_check_init);
548 * fd.io coding-style-patch-verification: ON
551 * eval: (c-set-style "gnu")