2 * Copyright (c) 2016 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 #include <vnet/vnet.h>
17 #include <vnet/ip/ip.h>
18 #include <vnet/mpls/mpls.h>
22 * @brief Feature Subgraph Ordering.
24 Dynamically compute feature subgraph ordering by performing a
25 topological sort across a set of "feature A before feature B" and
26 "feature C after feature B" constraints.
28 Use the topological sort result to set up vnet_config_main_t's for
31 Feature subgraph arcs are simple enough. They start at specific
32 fixed nodes, and end at specific fixed nodes. In between, a
33 per-interface current feature configuration dictates which
34 additional nodes each packet visits. Each so-called feature node
35 can [of course] drop any specific packet.
37 See ip4_forward.c, ip6_forward.c in this directory to see the
38 current rx-unicast, rx-multicast, and tx feature subgraph arc
41 Let's say that we wish to add a new feature to the ip4 unicast
42 feature subgraph arc, which needs to run before @c ip4-lookup. In
43 either base code or a plugin,
45 \#include <vnet/feature/feature.h>
48 and add the new feature as shown:
51 VNET_FEATURE_INIT (ip4_lookup, static) =
53 .arch_name = "ip4-unicast",
54 .node_name = "my-ip4-unicast-feature",
55 .runs_before = VLIB_FEATURES ("ip4-lookup", 0)
59 Here's the standard coding pattern to enable / disable
60 @c my-ip4-unicast-feature on an interface:
64 sw_if_index = <interface-handle>
65 vnet_feature_enable_disable ("ip4-unicast", "my-ip4-unicast-feature",
69 Here's how to obtain the correct next node index in packet
70 processing code, aka in the implementation of @c my-ip4-unicast-feature:
73 vnet_feature_main_t *fm = &feature_main;
74 vnet_feature_config_main_t * cm = &fm->feature_config_mains[VNET_FEAT_IP4_UNICAST];
76 Call @c vnet_get_config_data to set next0, and to advance
77 @c b0->current_config_index:
79 config_data0 = vnet_get_config_data (&cm->config_main,
80 &b0->current_config_index,
82 0 / * sizeof config data * /);
85 Nodes are free to drop or otherwise redirect packets. Packets
86 which "pass" should be enqueued via the next0 arc computed by
90 static const char *vnet_cast_names[] = VNET_CAST_NAMES;
93 comma_split (u8 * s, u8 ** a, u8 ** b)
97 while (*s && *s != ',')
110 * @brief Initialize a feature graph arc
111 * @param vm vlib main structure pointer
112 * @param vcm vnet config main structure pointer
113 * @param feature_start_nodes names of start-nodes which use this
115 * @param num_feature_start_nodes number of start-nodes
116 * @param first_reg first element in
117 * [an __attribute__((constructor)) function built, or
118 * otherwise created] singly-linked list of feature registrations
119 * @param [out] in_feature_nodes returned vector of
120 * topologically-sorted feature node names, for use in
122 * @returns 0 on success, otherwise an error message. Errors
123 * are fatal since they invariably involve mistyped node-names, or
124 * genuinely missing node-names
127 vnet_feature_arc_init (vlib_main_t * vm,
128 vnet_config_main_t * vcm,
129 char **feature_start_nodes,
130 int num_feature_start_nodes,
131 vnet_feature_registration_t * first_reg,
132 char ***in_feature_nodes)
134 uword *index_by_name;
138 char **these_constraints;
139 char *this_constraint_c;
140 u8 **constraints = 0;
141 u8 *constraint_tuple;
143 u8 **orig, **closure;
147 int a_index, b_index;
150 vnet_feature_registration_t *this_reg = 0;
151 char **feature_nodes = 0;
153 u8 **keys_to_delete = 0;
155 index_by_name = hash_create_string (0, sizeof (uword));
156 reg_by_index = hash_create (0, sizeof (uword));
158 this_reg = first_reg;
160 /* pass 1, collect feature node names, construct a before b pairs */
163 node_name = format (0, "%s%c", this_reg->node_name, 0);
164 hash_set (reg_by_index, vec_len (node_names), (uword) this_reg);
166 hash_set_mem (index_by_name, node_name, vec_len (node_names));
168 vec_add1 (node_names, node_name);
170 these_constraints = this_reg->runs_before;
171 while (these_constraints && these_constraints[0])
173 this_constraint_c = these_constraints[0];
175 constraint_tuple = format (0, "%s,%s%c", node_name,
176 this_constraint_c, 0);
177 vec_add1 (constraints, constraint_tuple);
181 these_constraints = this_reg->runs_after;
182 while (these_constraints && these_constraints[0])
184 this_constraint_c = these_constraints[0];
186 constraint_tuple = format (0, "%s,%s%c",
187 this_constraint_c, node_name, 0);
188 vec_add1 (constraints, constraint_tuple);
192 this_reg = this_reg->next;
195 n_features = vec_len (node_names);
196 orig = clib_ptclosure_alloc (n_features);
198 for (i = 0; i < vec_len (constraints); i++)
200 this_constraint = constraints[i];
202 if (comma_split (this_constraint, &a_name, &b_name))
203 return clib_error_return (0, "comma_split failed!");
205 p = hash_get_mem (index_by_name, a_name);
207 * Note: the next two errors mean that the xxx_FEATURE_INIT macros are
208 * b0rked. As in: if you code "A depends on B," and you forget
209 * to define a FEATURE_INIT macro for B, you lose.
210 * Nonexistent graph nodes are tolerated.
213 return clib_error_return (0, "feature node '%s' not found", a_name);
216 p = hash_get_mem (index_by_name, b_name);
218 return clib_error_return (0, "feature node '%s' not found", b_name);
221 /* add a before b to the original set of constraints */
222 orig[a_index][b_index] = 1;
223 vec_free (this_constraint);
226 /* Compute the positive transitive closure of the original constraints */
227 closure = clib_ptclosure (orig);
229 /* Compute a partial order across feature nodes, if one exists. */
231 for (i = 0; i < n_features; i++)
233 for (j = 0; j < n_features; j++)
236 goto item_constrained;
238 /* Item i can be output */
239 vec_add1 (result, i);
241 for (k = 0; k < n_features; k++)
244 * Add a "Magic" a before a constraint.
245 * This means we'll never output it again
254 /* see if we got a partial order... */
255 if (vec_len (result) != n_features)
256 return clib_error_return (0, "%d feature_init_cast no partial order!");
260 * Bind the index variables, and output the feature node name vector
261 * using the partial order we just computed. Result is in stack
262 * order, because the entry with the fewest constraints (e.g. none)
263 * is output first, etc.
266 for (i = n_features - 1; i >= 0; i--)
268 p = hash_get (reg_by_index, result[i]);
270 this_reg = (vnet_feature_registration_t *) p[0];
271 if (this_reg->feature_index)
272 *this_reg->feature_index = n_features - (i + 1);
273 this_reg->feature_index_u32 = n_features - (i + 1);
274 vec_add1 (feature_nodes, this_reg->node_name);
277 /* Set up the config infrastructure */
278 vnet_config_init (vm, vcm,
280 num_feature_start_nodes,
281 feature_nodes, vec_len (feature_nodes));
283 /* Save a copy for show command */
284 *in_feature_nodes = feature_nodes;
286 /* Finally, clean up all the shit we allocated */
288 hash_foreach_pair (hp, index_by_name,
290 vec_add1 (keys_to_delete, (u8 *)hp->key);
293 hash_free (index_by_name);
294 for (i = 0; i < vec_len (keys_to_delete); i++)
295 vec_free (keys_to_delete[i]);
296 vec_free (keys_to_delete);
297 hash_free (reg_by_index);
299 clib_ptclosure_free (orig);
300 clib_ptclosure_free (closure);
304 #define foreach_af_cast \
305 _(4, VNET_IP_RX_UNICAST_FEAT, "ip4 unicast") \
306 _(4, VNET_IP_RX_MULTICAST_FEAT, "ip4 multicast") \
307 _(4, VNET_IP_TX_FEAT, "ip4 output") \
308 _(6, VNET_IP_RX_UNICAST_FEAT, "ip6 unicast") \
309 _(6, VNET_IP_RX_MULTICAST_FEAT, "ip6 multicast") \
310 _(6, VNET_IP_TX_FEAT, "ip6 output")
312 /** Display the set of available ip features.
313 Useful for verifying that expected features are present
316 static clib_error_t *
317 show_ip_features_command_fn (vlib_main_t * vm,
318 unformat_input_t * input,
319 vlib_cli_command_t * cmd)
321 ip4_main_t *im4 = &ip4_main;
322 ip6_main_t *im6 = &ip6_main;
326 vlib_cli_output (vm, "Available IP feature nodes");
330 features = im##a->feature_nodes[c]; \
331 vlib_cli_output (vm, "%s:", s); \
332 for (i = 0; i < vec_len(features); i++) \
333 vlib_cli_output (vm, " %s\n", features[i]); \
342 * This command is used to display the set of available IP features.
343 * This can be useful for verifying that expected features are present.
346 * Example of how to display the set of available IP features:
347 * @cliexstart{show ip features}
348 * Available IP feature nodes
351 * ip4-source-check-via-rx
352 * ip4-source-check-via-any
353 * ip4-source-and-port-range-check-rx
354 * ip4-policer-classify
362 * ip4-lookup-multicast
364 * ip4-source-and-port-range-check-tx
368 * ip6-policer-classify
382 VLIB_CLI_COMMAND (show_ip_features_command, static) = {
383 .path = "show ip features",
384 .short_help = "show ip features",
385 .function = show_ip_features_command_fn,
389 /** Display the set of IP features configured on a specific interface
393 ip_interface_features_show (vlib_main_t * vm,
395 vnet_feature_config_main_t * cm, u32 sw_if_index)
397 u32 node_index, current_config_index;
399 vnet_config_main_t *vcm;
402 vnet_config_feature_t *feat;
406 vlib_cli_output (vm, "%s feature paths configured on %U...",
407 pname, format_vnet_sw_if_index_name,
408 vnet_get_main (), sw_if_index);
410 for (cast = VNET_IP_RX_UNICAST_FEAT; cast < VNET_N_IP_FEAT; cast++)
412 vcm = &(cm[cast].config_main);
414 vlib_cli_output (vm, "\n%s %s:", pname, vnet_cast_names[cast]);
416 if (NULL == cm[cast].config_index_by_sw_if_index ||
417 vec_len (cm[cast].config_index_by_sw_if_index) < sw_if_index)
419 vlib_cli_output (vm, "none configured");
423 current_config_index = vec_elt (cm[cast].config_index_by_sw_if_index,
426 ASSERT (current_config_index
427 < vec_len (vcm->config_pool_index_by_user_index));
429 cfg_index = vcm->config_pool_index_by_user_index[current_config_index];
430 cfg = pool_elt_at_index (vcm->config_pool, cfg_index);
432 for (i = 0; i < vec_len (cfg->features); i++)
434 feat = cfg->features + i;
435 node_index = feat->node_index;
436 n = vlib_get_node (vm, node_index);
437 vlib_cli_output (vm, " %v", n->name);
442 static clib_error_t *
443 show_ip_interface_features_command_fn (vlib_main_t * vm,
444 unformat_input_t * input,
445 vlib_cli_command_t * cmd)
447 vnet_main_t *vnm = vnet_get_main ();
448 ip4_main_t *im4 = &ip4_main;
449 ip_lookup_main_t *lm4 = &im4->lookup_main;
450 ip6_main_t *im6 = &ip6_main;
451 ip_lookup_main_t *lm6 = &im6->lookup_main;
453 ip_lookup_main_t *lm;
456 if (!unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
457 return clib_error_return (0, "Interface not specified...");
459 vlib_cli_output (vm, "IP feature paths configured on %U...",
460 format_vnet_sw_if_index_name, vnm, sw_if_index);
462 for (af = 0; af < 2; af++)
469 ip_interface_features_show (vm, (af == 0) ? "ip4" : "ip6",
470 lm->feature_config_mains, sw_if_index);
477 * This command is used to display the set of IP features configured
478 * on a specific interface
481 * Example of how to display the set of available IP features on an interface:
482 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
483 * IP feature paths configured on GigabitEthernet2/0/0...
487 * ip4-lookup-multicast
499 VLIB_CLI_COMMAND (show_ip_interface_features_command, static) = {
500 .path = "show ip interface features",
501 .short_help = "show ip interface features <interface>",
502 .function = show_ip_interface_features_command_fn,
507 * fd.io coding-style-patch-verification: ON
510 * eval: (c-set-style "gnu")