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);
154 vnet_feature_next_with_data (vnet_buffer (p0)->sw_if_index
155 [VLIB_RX], &next0, p0,
158 vnet_feature_next_with_data (vnet_buffer (p1)->sw_if_index
159 [VLIB_RX], &next1, p1,
162 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
163 mtrie1 = &ip4_fib_get (c1->fib_index)->mtrie;
165 leaf0 = leaf1 = IP4_FIB_MTRIE_LEAF_ROOT;
168 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
170 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 0);
173 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
175 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 1);
178 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
180 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 2);
183 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
185 ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 3);
187 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
188 lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
190 lb0 = load_balance_get (lb_index0);
191 lb1 = load_balance_get (lb_index1);
193 /* Pass multicast. */
194 pass0 = ip4_address_is_multicast (&ip0->src_address)
195 || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
196 pass1 = ip4_address_is_multicast (&ip1->src_address)
197 || ip1->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
199 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
201 pass0 |= fib_urpf_check (lb0->lb_urpf,
202 vnet_buffer (p0)->sw_if_index
205 fib_urpf_check (lb1->lb_urpf,
206 vnet_buffer (p1)->sw_if_index[VLIB_RX]);
210 pass0 |= fib_urpf_check_size (lb0->lb_urpf);
211 pass1 |= fib_urpf_check_size (lb1->lb_urpf);
213 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
214 next1 = (pass1 ? next1 : IP4_SOURCE_CHECK_NEXT_DROP);
217 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
219 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
221 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
222 to_next, n_left_to_next,
223 pi0, pi1, next0, next1);
226 while (n_left_from > 0 && n_left_to_next > 0)
230 ip4_fib_mtrie_t *mtrie0;
231 ip4_fib_mtrie_leaf_t leaf0;
232 ip4_source_check_config_t *c0;
233 u32 pi0, next0, pass0, lb_index0;
234 const load_balance_t *lb0;
243 p0 = vlib_get_buffer (vm, pi0);
244 ip0 = vlib_buffer_get_current (p0);
247 vnet_feature_next_with_data (vnet_buffer (p0)->sw_if_index
248 [VLIB_RX], &next0, p0,
251 mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
253 leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
256 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
259 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
262 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
265 ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
267 lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
269 lb0 = load_balance_get (lb_index0);
271 /* Pass multicast. */
272 pass0 = ip4_address_is_multicast (&ip0->src_address)
273 || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
275 if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
277 pass0 |= fib_urpf_check (lb0->lb_urpf,
278 vnet_buffer (p0)->sw_if_index
283 pass0 |= fib_urpf_check_size (lb0->lb_urpf);
286 next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
288 error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
290 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
291 to_next, n_left_to_next,
295 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
298 return frame->n_vectors;
302 ip4_source_check_reachable_via_any (vlib_main_t * vm,
303 vlib_node_runtime_t * node,
304 vlib_frame_t * frame)
306 return ip4_source_check_inline (vm, node, frame,
307 IP4_SOURCE_CHECK_REACHABLE_VIA_ANY);
311 ip4_source_check_reachable_via_rx (vlib_main_t * vm,
312 vlib_node_runtime_t * node,
313 vlib_frame_t * frame)
315 return ip4_source_check_inline (vm, node, frame,
316 IP4_SOURCE_CHECK_REACHABLE_VIA_RX);
320 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_any) = {
321 .function = ip4_source_check_reachable_via_any,
322 .name = "ip4-source-check-via-any",
323 .vector_size = sizeof (u32),
325 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
327 [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
330 .format_buffer = format_ip4_header,
331 .format_trace = format_ip4_source_check_trace,
335 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_any,
336 ip4_source_check_reachable_via_any);
339 VLIB_REGISTER_NODE (ip4_check_source_reachable_via_rx) = {
340 .function = ip4_source_check_reachable_via_rx,
341 .name = "ip4-source-check-via-rx",
342 .vector_size = sizeof (u32),
344 .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
346 [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
349 .format_buffer = format_ip4_header,
350 .format_trace = format_ip4_source_check_trace,
354 VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_rx,
355 ip4_source_check_reachable_via_rx);
357 static clib_error_t *
358 set_ip_source_check (vlib_main_t * vm,
359 unformat_input_t * input, vlib_cli_command_t * cmd)
361 unformat_input_t _line_input, *line_input = &_line_input;
362 vnet_main_t *vnm = vnet_get_main ();
363 ip4_main_t *im = &ip4_main;
364 clib_error_t *error = 0;
365 u32 sw_if_index, is_del;
366 ip4_source_check_config_t config;
367 char *feature_name = "ip4-source-check-via-rx";
372 if (!unformat_user (input, unformat_line_input, line_input))
375 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
378 (line_input, unformat_vnet_sw_interface, vnm, &sw_if_index))
380 else if (unformat (line_input, "del"))
382 else if (unformat (line_input, "loose"))
383 feature_name = "ip4-source-check-via-any";
386 error = unformat_parse_error (line_input);
391 if (~0 == sw_if_index)
393 error = clib_error_return (0, "unknown interface `%U'",
394 format_unformat_error, line_input);
398 config.fib_index = im->fib_index_by_sw_if_index[sw_if_index];
399 vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index,
400 is_del == 0, &config, sizeof (config));
402 unformat_free (line_input);
408 * This command adds the 'ip4-source-check-via-rx' graph node for
409 * a given interface. By adding the IPv4 source check graph node to
410 * an interface, the code verifies that the source address of incoming
411 * unicast packets are reachable over the incoming interface. Two flavours
412 * are supported (the default is strict):
413 * - loose: accept ingress packet if there is a route to reach the source
414 * - strict: accept ingress packet if it arrived on an interface which
415 * the route to the source uses. i.e. an interface that the source
420 * Example of graph node before range checking is enabled:
421 * @cliexstart{show vlib graph ip4-source-check-via-rx}
423 * ip4-source-check-via-rx error-drop [0]
426 * Example of how to enable unicast source checking on an interface:
427 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 loose}
429 * Example of graph node after range checking is enabled:
430 * @cliexstart{show vlib graph ip4-source-check-via-rx}
432 * ip4-source-check-via-rx error-drop [0] ip4-input-no-checksum
433 * ip4-source-and-port-range- ip4-input
436 * Example of how to display the feature enabed on an interface:
437 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
438 * IP feature paths configured on GigabitEthernet2/0/0...
441 * ip4-source-check-via-rx
445 * ip4-lookup-multicast
460 * Example of how to disable unicast source checking on an interface:
461 * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 del}
465 VLIB_CLI_COMMAND (set_interface_ip_source_check_command, static) = {
466 .path = "set interface ip source-check",
467 .function = set_ip_source_check,
468 .short_help = "set interface ip source-check <interface> [strict|loose] [del]",
472 static clib_error_t *
473 ip_source_check_accept (vlib_main_t * vm,
474 unformat_input_t * input, vlib_cli_command_t * cmd)
476 unformat_input_t _line_input, *line_input = &_line_input;
478 .fp_proto = FIB_PROTOCOL_IP4,
480 clib_error_t *error = NULL;
481 u32 table_id, is_add, fib_index;
486 /* Get a line of input. */
487 if (!unformat_user (input, unformat_line_input, line_input))
490 while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
492 if (unformat (line_input, "table %d", &table_id))
494 else if (unformat (line_input, "del"))
496 else if (unformat (line_input, "add"))
498 else if (unformat (line_input, "%U/%d",
499 unformat_ip4_address, &pfx.fp_addr.ip4, &pfx.fp_len))
500 pfx.fp_proto = FIB_PROTOCOL_IP4;
503 error = unformat_parse_error (line_input);
510 fib_index = fib_table_id_find_fib_index (pfx.fp_proto, table_id);
513 error = clib_error_return (0, "Nonexistent table id %d", table_id);
524 fib_table_entry_special_add (fib_index,
526 FIB_SOURCE_URPF_EXEMPT,
527 FIB_ENTRY_FLAG_DROP, ADJ_INDEX_INVALID);
531 fib_table_entry_special_remove (fib_index,
532 &pfx, FIB_SOURCE_URPF_EXEMPT);
536 unformat_free (line_input);
542 * Add an exemption for a prefix to pass the Unicast Reverse Path
543 * Forwarding (uRPF) loose check. This is for testing purposes only.
544 * If the '<em>table</em>' is not enter it is defaulted to 0. Default
545 * is to '<em>add</em>'. VPP always performs a loose uRPF check for
549 * Example of how to add a uRPF exception to a FIB table to pass the
551 * @cliexcmd{ip urpf-accept table 7 add}
554 VLIB_CLI_COMMAND (ip_source_check_accept_command, static) = {
555 .path = "ip urpf-accept",
556 .function = ip_source_check_accept,
557 .short_help = "ip urpf-accept [table <table-id>] [add|del]",
562 /* Dummy init function to get us linked in. */
564 ip4_source_check_init (vlib_main_t * vm)
569 VLIB_INIT_FUNCTION (ip4_source_check_init);
572 * fd.io coding-style-patch-verification: ON
575 * eval: (c-set-style "gnu")