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_input.c: IP v4 input node
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/ethernet/ethernet.h>
42 #include <vnet/ppp/ppp.h>
43 #include <vnet/hdlc/hdlc.h>
49 static u8 * format_ip4_input_trace (u8 * s, va_list * va)
51 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
52 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
53 ip4_input_trace_t * t = va_arg (*va, ip4_input_trace_t *);
57 t->packet_data, sizeof (t->packet_data));
65 IP4_INPUT_NEXT_LOOKUP,
66 IP4_INPUT_NEXT_LOOKUP_MULTICAST,
67 IP4_INPUT_NEXT_ICMP_ERROR,
71 /* Validate IP v4 packets and pass them either to forwarding code
72 or drop/punt exception packets. */
74 ip4_input_inline (vlib_main_t * vm,
75 vlib_node_runtime_t * node,
79 ip4_main_t * im = &ip4_main;
80 vnet_main_t * vnm = vnet_get_main();
81 ip_lookup_main_t * lm = &im->lookup_main;
82 u32 n_left_from, * from, * to_next;
83 ip4_input_next_t next_index;
84 vlib_node_runtime_t * error_node = vlib_node_get_runtime (vm, ip4_input_node.index);
85 vlib_simple_counter_main_t * cm;
86 u32 cpu_index = os_get_cpu_number();
88 from = vlib_frame_vector_args (frame);
89 n_left_from = frame->n_vectors;
90 next_index = node->cached_next_index;
92 if (node->flags & VLIB_NODE_FLAG_TRACE)
93 vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
95 sizeof (ip4_input_trace_t));
97 cm = vec_elt_at_index (vnm->interface_main.sw_if_counters,
98 VNET_INTERFACE_COUNTER_IP4);
100 while (n_left_from > 0)
104 vlib_get_next_frame (vm, node, next_index,
105 to_next, n_left_to_next);
107 while (n_left_from >= 4 && n_left_to_next >= 2)
109 vlib_buffer_t * p0, * p1;
110 ip4_header_t * ip0, * ip1;
111 u32 sw_if_index0, pi0, ip_len0, cur_len0, next0 = 0;
112 u32 sw_if_index1, pi1, ip_len1, cur_len1, next1 = 0;
113 i32 len_diff0, len_diff1;
114 u8 error0, error1, arc0, arc1;
116 /* Prefetch next iteration. */
118 vlib_buffer_t * p2, * p3;
120 p2 = vlib_get_buffer (vm, from[2]);
121 p3 = vlib_get_buffer (vm, from[3]);
123 vlib_prefetch_buffer_header (p2, LOAD);
124 vlib_prefetch_buffer_header (p3, LOAD);
126 CLIB_PREFETCH (p2->data, sizeof (ip0[0]), LOAD);
127 CLIB_PREFETCH (p3->data, sizeof (ip1[0]), LOAD);
130 to_next[0] = pi0 = from[0];
131 to_next[1] = pi1 = from[1];
137 p0 = vlib_get_buffer (vm, pi0);
138 p1 = vlib_get_buffer (vm, pi1);
140 ip0 = vlib_buffer_get_current (p0);
141 ip1 = vlib_buffer_get_current (p1);
143 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
144 sw_if_index1 = vnet_buffer (p1)->sw_if_index[VLIB_RX];
146 arc0 = ip4_address_is_multicast (&ip0->dst_address) ? lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
147 arc1 = ip4_address_is_multicast (&ip1->dst_address) ? lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
149 vnet_buffer (p0)->ip.adj_index[VLIB_RX] = ~0;
150 vnet_buffer (p1)->ip.adj_index[VLIB_RX] = ~0;
152 vnet_feature_arc_start (arc0, sw_if_index0, &next0, p0);
153 vnet_feature_arc_start (arc1, sw_if_index1, &next1, p1);
155 vlib_increment_simple_counter (cm, cpu_index, sw_if_index0, 1);
156 vlib_increment_simple_counter (cm, cpu_index, sw_if_index1, 1);
158 error0 = error1 = IP4_ERROR_NONE;
160 /* Punt packets with options. */
161 error0 = (ip0->ip_version_and_header_length & 0xf) != 5 ? IP4_ERROR_OPTIONS : error0;
162 error1 = (ip1->ip_version_and_header_length & 0xf) != 5 ? IP4_ERROR_OPTIONS : error1;
164 /* Version != 4? Drop it. */
165 error0 = (ip0->ip_version_and_header_length >> 4) != 4 ? IP4_ERROR_VERSION : error0;
166 error1 = (ip1->ip_version_and_header_length >> 4) != 4 ? IP4_ERROR_VERSION : error1;
168 /* Verify header checksum. */
171 ip_csum_t sum0, sum1;
173 ip4_partial_header_checksum_x1 (ip0, sum0);
174 ip4_partial_header_checksum_x1 (ip1, sum1);
176 error0 = 0xffff != ip_csum_fold (sum0) ? IP4_ERROR_BAD_CHECKSUM : error0;
177 error1 = 0xffff != ip_csum_fold (sum1) ? IP4_ERROR_BAD_CHECKSUM : error1;
180 /* Drop fragmentation offset 1 packets. */
181 error0 = ip4_get_fragment_offset (ip0) == 1 ? IP4_ERROR_FRAGMENT_OFFSET_ONE : error0;
182 error1 = ip4_get_fragment_offset (ip1) == 1 ? IP4_ERROR_FRAGMENT_OFFSET_ONE : error1;
184 /* TTL < 1? Drop it. */
185 error0 = (ip0->ttl < 1 && arc0 == lm->ucast_feature_arc_index) ? IP4_ERROR_TIME_EXPIRED : error0;
186 error1 = (ip1->ttl < 1 && arc1 == lm->ucast_feature_arc_index) ? IP4_ERROR_TIME_EXPIRED : error1;
188 /* Verify lengths. */
189 ip_len0 = clib_net_to_host_u16 (ip0->length);
190 ip_len1 = clib_net_to_host_u16 (ip1->length);
192 /* IP length must be at least minimal IP header. */
193 error0 = ip_len0 < sizeof (ip0[0]) ? IP4_ERROR_TOO_SHORT : error0;
194 error1 = ip_len1 < sizeof (ip1[0]) ? IP4_ERROR_TOO_SHORT : error1;
196 cur_len0 = vlib_buffer_length_in_chain (vm, p0);
197 cur_len1 = vlib_buffer_length_in_chain (vm, p1);
199 len_diff0 = cur_len0 - ip_len0;
200 len_diff1 = cur_len1 - ip_len1;
202 error0 = len_diff0 < 0 ? IP4_ERROR_BAD_LENGTH : error0;
203 error1 = len_diff1 < 0 ? IP4_ERROR_BAD_LENGTH : error1;
205 p0->error = error_node->errors[error0];
206 p1->error = error_node->errors[error1];
208 if (PREDICT_FALSE(error0 != IP4_ERROR_NONE))
210 if (error0 == IP4_ERROR_TIME_EXPIRED) {
211 icmp4_error_set_vnet_buffer(p0, ICMP4_time_exceeded,
212 ICMP4_time_exceeded_ttl_exceeded_in_transit, 0);
213 next0 = IP4_INPUT_NEXT_ICMP_ERROR;
215 next0 = error0 != IP4_ERROR_OPTIONS ? IP4_INPUT_NEXT_DROP : IP4_INPUT_NEXT_PUNT;
217 if (PREDICT_FALSE(error1 != IP4_ERROR_NONE))
219 if (error1 == IP4_ERROR_TIME_EXPIRED) {
220 icmp4_error_set_vnet_buffer(p1, ICMP4_time_exceeded,
221 ICMP4_time_exceeded_ttl_exceeded_in_transit, 0);
222 next1 = IP4_INPUT_NEXT_ICMP_ERROR;
224 next1 = error1 != IP4_ERROR_OPTIONS ? IP4_INPUT_NEXT_DROP : IP4_INPUT_NEXT_PUNT;
227 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
228 to_next, n_left_to_next,
229 pi0, pi1, next0, next1);
231 while (n_left_from > 0 && n_left_to_next > 0)
235 u32 sw_if_index0, pi0, ip_len0, cur_len0, next0 = 0;
246 p0 = vlib_get_buffer (vm, pi0);
247 ip0 = vlib_buffer_get_current (p0);
249 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
251 arc0 = ip4_address_is_multicast (&ip0->dst_address) ? lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
252 vnet_buffer (p0)->ip.adj_index[VLIB_RX] = ~0;
253 vnet_feature_arc_start (arc0, sw_if_index0, &next0, p0);
255 vlib_increment_simple_counter (cm, cpu_index, sw_if_index0, 1);
257 error0 = IP4_ERROR_NONE;
259 /* Punt packets with options. */
260 error0 = (ip0->ip_version_and_header_length & 0xf) != 5 ? IP4_ERROR_OPTIONS : error0;
262 /* Version != 4? Drop it. */
263 error0 = (ip0->ip_version_and_header_length >> 4) != 4 ? IP4_ERROR_VERSION : error0;
265 /* Verify header checksum. */
270 ip4_partial_header_checksum_x1 (ip0, sum0);
271 error0 = 0xffff != ip_csum_fold (sum0) ? IP4_ERROR_BAD_CHECKSUM : error0;
274 /* Drop fragmentation offset 1 packets. */
275 error0 = ip4_get_fragment_offset (ip0) == 1 ? IP4_ERROR_FRAGMENT_OFFSET_ONE : error0;
277 /* TTL < 1? Drop it. */
278 error0 = (ip0->ttl < 1 && arc0 == lm->ucast_feature_arc_index) ? IP4_ERROR_TIME_EXPIRED : error0;
280 /* Verify lengths. */
281 ip_len0 = clib_net_to_host_u16 (ip0->length);
283 /* IP length must be at least minimal IP header. */
284 error0 = ip_len0 < sizeof (ip0[0]) ? IP4_ERROR_TOO_SHORT : error0;
286 cur_len0 = vlib_buffer_length_in_chain (vm, p0);
287 len_diff0 = cur_len0 - ip_len0;
288 error0 = len_diff0 < 0 ? IP4_ERROR_BAD_LENGTH : error0;
290 p0->error = error_node->errors[error0];
291 if (PREDICT_FALSE(error0 != IP4_ERROR_NONE))
293 if (error0 == IP4_ERROR_TIME_EXPIRED) {
294 icmp4_error_set_vnet_buffer(p0, ICMP4_time_exceeded,
295 ICMP4_time_exceeded_ttl_exceeded_in_transit, 0);
296 next0 = IP4_INPUT_NEXT_ICMP_ERROR;
298 next0 = error0 != IP4_ERROR_OPTIONS ? IP4_INPUT_NEXT_DROP : IP4_INPUT_NEXT_PUNT;
301 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
302 to_next, n_left_to_next,
306 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
309 return frame->n_vectors;
312 /** \brief IPv4 input node.
315 This is the IPv4 input node: validates ip4 header checksums,
316 verifies ip header lengths, discards pkts with expired TTLs,
317 and sends pkts to the set of ip feature nodes configured on
320 @param vm vlib_main_t corresponding to the current thread
321 @param node vlib_node_runtime_t
322 @param frame vlib_frame_t whose contents should be dispatched
324 @par Graph mechanics: buffer metadata, next index usage
327 - vnet_feature_config_main_t cm corresponding to each pkt's dst address unicast /
329 - <code>b->current_config_index</code> corresponding to each pkt's
331 - This sets the per-packet graph trajectory, ensuring that
332 each packet visits the per-interface features in order.
334 - <code>vnet_buffer(b)->sw_if_index[VLIB_RX]</code>
335 - Indicates the @c sw_if_index value of the interface that the
336 packet was received on.
339 - <code>vnet_buffer(b)->ip.adj_index[VLIB_TX]</code>
340 - The lookup result adjacency index.
342 <em>Next Indices:</em>
343 - Dispatches pkts to the (first) feature node:
344 <code> vnet_get_config_data (... &next0 ...); </code>
348 ip4_input (vlib_main_t * vm,
349 vlib_node_runtime_t * node,
350 vlib_frame_t * frame)
352 return ip4_input_inline (vm, node, frame, /* verify_checksum */ 1);
356 ip4_input_no_checksum (vlib_main_t * vm,
357 vlib_node_runtime_t * node,
358 vlib_frame_t * frame)
360 return ip4_input_inline (vm, node, frame, /* verify_checksum */ 0);
363 static char * ip4_error_strings[] = {
364 #define _(sym,string) string,
369 VLIB_REGISTER_NODE (ip4_input_node) = {
370 .function = ip4_input,
372 .vector_size = sizeof (u32),
374 .n_errors = IP4_N_ERROR,
375 .error_strings = ip4_error_strings,
377 .n_next_nodes = IP4_INPUT_N_NEXT,
379 [IP4_INPUT_NEXT_DROP] = "error-drop",
380 [IP4_INPUT_NEXT_PUNT] = "error-punt",
381 [IP4_INPUT_NEXT_LOOKUP] = "ip4-lookup",
382 [IP4_INPUT_NEXT_LOOKUP_MULTICAST] = "ip4-lookup-multicast",
383 [IP4_INPUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
386 .format_buffer = format_ip4_header,
387 .format_trace = format_ip4_input_trace,
390 VLIB_NODE_FUNCTION_MULTIARCH (ip4_input_node, ip4_input)
392 VLIB_REGISTER_NODE (ip4_input_no_checksum_node,static) = {
393 .function = ip4_input_no_checksum,
394 .name = "ip4-input-no-checksum",
395 .vector_size = sizeof (u32),
397 .n_next_nodes = IP4_INPUT_N_NEXT,
399 [IP4_INPUT_NEXT_DROP] = "error-drop",
400 [IP4_INPUT_NEXT_PUNT] = "error-punt",
401 [IP4_INPUT_NEXT_LOOKUP] = "ip4-lookup",
402 [IP4_INPUT_NEXT_LOOKUP_MULTICAST] = "ip4-lookup-multicast",
403 [IP4_INPUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
406 .format_buffer = format_ip4_header,
407 .format_trace = format_ip4_input_trace,
410 VLIB_NODE_FUNCTION_MULTIARCH (ip4_input_no_checksum_node, ip4_input_no_checksum)
412 static clib_error_t * ip4_init (vlib_main_t * vm)
414 clib_error_t * error;
416 ethernet_register_input_type (vm, ETHERNET_TYPE_IP4,
417 ip4_input_node.index);
418 ppp_register_input_protocol (vm, PPP_PROTOCOL_ip4,
419 ip4_input_node.index);
420 hdlc_register_input_protocol (vm, HDLC_PROTOCOL_ip4,
421 ip4_input_node.index);
425 pn = pg_get_node (ip4_input_node.index);
426 pn->unformat_edit = unformat_pg_ip4_header;
427 pn = pg_get_node (ip4_input_no_checksum_node.index);
428 pn->unformat_edit = unformat_pg_ip4_header;
431 if ((error = vlib_call_init_function (vm, ip4_cli_init)))
434 if ((error = vlib_call_init_function (vm, ip4_source_check_init)))
437 if ((error = vlib_call_init_function
438 (vm, ip4_source_and_port_range_check_init)))
441 /* Set flow hash to something non-zero. */
442 ip4_main.flow_hash_seed = 0xdeadbeef;
444 /* Default TTL for packets we generate. */
445 ip4_main.host_config.ttl = 64;
450 VLIB_INIT_FUNCTION (ip4_init);