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")
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_next (sw_if_index0, &next0, b0);
77 Nodes are free to drop or otherwise redirect packets. Packets
78 which "pass" should be enqueued via the next0 arc computed by
82 static const char *vnet_cast_names[] = VNET_CAST_NAMES;
85 comma_split (u8 * s, u8 ** a, u8 ** b)
89 while (*s && *s != ',')
102 * @brief Initialize a feature graph arc
103 * @param vm vlib main structure pointer
104 * @param vcm vnet config main structure pointer
105 * @param feature_start_nodes names of start-nodes which use this
107 * @param num_feature_start_nodes number of start-nodes
108 * @param first_reg first element in
109 * [an __attribute__((constructor)) function built, or
110 * otherwise created] singly-linked list of feature registrations
111 * @param [out] in_feature_nodes returned vector of
112 * topologically-sorted feature node names, for use in
114 * @returns 0 on success, otherwise an error message. Errors
115 * are fatal since they invariably involve mistyped node-names, or
116 * genuinely missing node-names
119 vnet_feature_arc_init (vlib_main_t * vm,
120 vnet_config_main_t * vcm,
121 char **feature_start_nodes,
122 int num_feature_start_nodes,
123 vnet_feature_registration_t * first_reg,
124 char ***in_feature_nodes)
126 uword *index_by_name;
130 char **these_constraints;
131 char *this_constraint_c;
132 u8 **constraints = 0;
133 u8 *constraint_tuple;
135 u8 **orig, **closure;
139 int a_index, b_index;
142 vnet_feature_registration_t *this_reg = 0;
143 char **feature_nodes = 0;
145 u8 **keys_to_delete = 0;
147 index_by_name = hash_create_string (0, sizeof (uword));
148 reg_by_index = hash_create (0, sizeof (uword));
150 this_reg = first_reg;
152 /* pass 1, collect feature node names, construct a before b pairs */
155 node_name = format (0, "%s%c", this_reg->node_name, 0);
156 hash_set (reg_by_index, vec_len (node_names), (uword) this_reg);
158 hash_set_mem (index_by_name, node_name, vec_len (node_names));
160 vec_add1 (node_names, node_name);
162 these_constraints = this_reg->runs_before;
163 while (these_constraints && these_constraints[0])
165 this_constraint_c = these_constraints[0];
167 constraint_tuple = format (0, "%s,%s%c", node_name,
168 this_constraint_c, 0);
169 vec_add1 (constraints, constraint_tuple);
173 these_constraints = this_reg->runs_after;
174 while (these_constraints && these_constraints[0])
176 this_constraint_c = these_constraints[0];
178 constraint_tuple = format (0, "%s,%s%c",
179 this_constraint_c, node_name, 0);
180 vec_add1 (constraints, constraint_tuple);
184 this_reg = this_reg->next;
187 n_features = vec_len (node_names);
188 orig = clib_ptclosure_alloc (n_features);
190 for (i = 0; i < vec_len (constraints); i++)
192 this_constraint = constraints[i];
194 if (comma_split (this_constraint, &a_name, &b_name))
195 return clib_error_return (0, "comma_split failed!");
197 p = hash_get_mem (index_by_name, a_name);
199 * Note: the next two errors mean that the xxx_FEATURE_INIT macros are
200 * b0rked. As in: if you code "A depends on B," and you forget
201 * to define a FEATURE_INIT macro for B, you lose.
202 * Nonexistent graph nodes are tolerated.
205 return clib_error_return (0, "feature node '%s' not found", a_name);
208 p = hash_get_mem (index_by_name, b_name);
210 return clib_error_return (0, "feature node '%s' not found", b_name);
213 /* add a before b to the original set of constraints */
214 orig[a_index][b_index] = 1;
215 vec_free (this_constraint);
218 /* Compute the positive transitive closure of the original constraints */
219 closure = clib_ptclosure (orig);
221 /* Compute a partial order across feature nodes, if one exists. */
223 for (i = 0; i < n_features; i++)
225 for (j = 0; j < n_features; j++)
228 goto item_constrained;
230 /* Item i can be output */
231 vec_add1 (result, i);
233 for (k = 0; k < n_features; k++)
236 * Add a "Magic" a before a constraint.
237 * This means we'll never output it again
246 /* see if we got a partial order... */
247 if (vec_len (result) != n_features)
248 return clib_error_return (0, "%d feature_init_cast no partial order!");
252 * Bind the index variables, and output the feature node name vector
253 * using the partial order we just computed. Result is in stack
254 * order, because the entry with the fewest constraints (e.g. none)
255 * is output first, etc.
258 for (i = n_features - 1; i >= 0; i--)
260 p = hash_get (reg_by_index, result[i]);
262 this_reg = (vnet_feature_registration_t *) p[0];
263 if (this_reg->feature_index)
264 *this_reg->feature_index = n_features - (i + 1);
265 this_reg->feature_index_u32 = n_features - (i + 1);
266 vec_add1 (feature_nodes, this_reg->node_name);
269 /* Set up the config infrastructure */
270 vnet_config_init (vm, vcm,
272 num_feature_start_nodes,
273 feature_nodes, vec_len (feature_nodes));
275 /* Save a copy for show command */
276 *in_feature_nodes = feature_nodes;
278 /* Finally, clean up all the shit we allocated */
280 hash_foreach_pair (hp, index_by_name,
282 vec_add1 (keys_to_delete, (u8 *)hp->key);
285 hash_free (index_by_name);
286 for (i = 0; i < vec_len (keys_to_delete); i++)
287 vec_free (keys_to_delete[i]);
288 vec_free (keys_to_delete);
289 hash_free (reg_by_index);
291 clib_ptclosure_free (orig);
292 clib_ptclosure_free (closure);
296 #define foreach_af_cast \
297 _(4, VNET_IP_RX_UNICAST_FEAT, "ip4 unicast") \
298 _(4, VNET_IP_RX_MULTICAST_FEAT, "ip4 multicast") \
299 _(4, VNET_IP_TX_FEAT, "ip4 output") \
300 _(6, VNET_IP_RX_UNICAST_FEAT, "ip6 unicast") \
301 _(6, VNET_IP_RX_MULTICAST_FEAT, "ip6 multicast") \
302 _(6, VNET_IP_TX_FEAT, "ip6 output")
304 /** Display the set of available ip features.
305 Useful for verifying that expected features are present
308 static clib_error_t *
309 show_ip_features_command_fn (vlib_main_t * vm,
310 unformat_input_t * input,
311 vlib_cli_command_t * cmd)
313 ip4_main_t *im4 = &ip4_main;
314 ip6_main_t *im6 = &ip6_main;
318 vlib_cli_output (vm, "Available IP feature nodes");
322 features = im##a->feature_nodes[c]; \
323 vlib_cli_output (vm, "%s:", s); \
324 for (i = 0; i < vec_len(features); i++) \
325 vlib_cli_output (vm, " %s\n", features[i]); \
334 * This command is used to display the set of available IP features.
335 * This can be useful for verifying that expected features are present.
338 * Example of how to display the set of available IP features:
339 * @cliexstart{show ip features}
340 * Available IP feature nodes
343 * ip4-source-check-via-rx
344 * ip4-source-check-via-any
345 * ip4-source-and-port-range-check-rx
346 * ip4-policer-classify
354 * ip4-lookup-multicast
356 * ip4-source-and-port-range-check-tx
360 * ip6-policer-classify
374 VLIB_CLI_COMMAND (show_ip_features_command, static) = {
375 .path = "show ip features",
376 .short_help = "show ip features",
377 .function = show_ip_features_command_fn,
381 /** Display the set of IP features configured on a specific interface
385 ip_interface_features_show (vlib_main_t * vm,
387 vnet_feature_config_main_t * cm, u32 sw_if_index)
389 u32 node_index, current_config_index;
391 vnet_config_main_t *vcm;
394 vnet_config_feature_t *feat;
398 vlib_cli_output (vm, "%s feature paths configured on %U...",
399 pname, format_vnet_sw_if_index_name,
400 vnet_get_main (), sw_if_index);
402 for (cast = VNET_IP_RX_UNICAST_FEAT; cast < VNET_N_IP_FEAT; cast++)
404 vcm = &(cm[cast].config_main);
406 vlib_cli_output (vm, "\n%s %s:", pname, vnet_cast_names[cast]);
408 if (NULL == cm[cast].config_index_by_sw_if_index ||
409 vec_len (cm[cast].config_index_by_sw_if_index) < sw_if_index)
411 vlib_cli_output (vm, "none configured");
415 current_config_index = vec_elt (cm[cast].config_index_by_sw_if_index,
418 ASSERT (current_config_index
419 < vec_len (vcm->config_pool_index_by_user_index));
421 cfg_index = vcm->config_pool_index_by_user_index[current_config_index];
422 cfg = pool_elt_at_index (vcm->config_pool, cfg_index);
424 for (i = 0; i < vec_len (cfg->features); i++)
426 feat = cfg->features + i;
427 node_index = feat->node_index;
428 n = vlib_get_node (vm, node_index);
429 vlib_cli_output (vm, " %v", n->name);
434 static clib_error_t *
435 show_ip_interface_features_command_fn (vlib_main_t * vm,
436 unformat_input_t * input,
437 vlib_cli_command_t * cmd)
439 vnet_main_t *vnm = vnet_get_main ();
440 ip4_main_t *im4 = &ip4_main;
441 ip_lookup_main_t *lm4 = &im4->lookup_main;
442 ip6_main_t *im6 = &ip6_main;
443 ip_lookup_main_t *lm6 = &im6->lookup_main;
445 ip_lookup_main_t *lm;
448 if (!unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
449 return clib_error_return (0, "Interface not specified...");
451 vlib_cli_output (vm, "IP feature paths configured on %U...",
452 format_vnet_sw_if_index_name, vnm, sw_if_index);
454 for (af = 0; af < 2; af++)
461 ip_interface_features_show (vm, (af == 0) ? "ip4" : "ip6",
462 lm->feature_config_mains, sw_if_index);
469 * This command is used to display the set of IP features configured
470 * on a specific interface
473 * Example of how to display the set of available IP features on an interface:
474 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
475 * IP feature paths configured on GigabitEthernet2/0/0...
479 * ip4-lookup-multicast
491 VLIB_CLI_COMMAND (show_ip_interface_features_command, static) = {
492 .path = "show ip interface features",
493 .short_help = "show ip interface features <interface>",
494 .function = show_ip_interface_features_command_fn,
499 * fd.io coding-style-patch-verification: ON
502 * eval: (c-set-style "gnu")