abf_policy.c revision 13b2ba2a
1/*
2 * Copyright (c) 2017 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:
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
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.
14 */
15
16#include <plugins/abf/abf_policy.h>
17
18#include <vlib/vlib.h>
19#include <vnet/plugin/plugin.h>
20#include <vnet/fib/fib_path_list.h>
21#include <vnet/fib/fib_walk.h>
22
23/**
24 * FIB node type the attachment is registered
25 */
26fib_node_type_t abf_policy_fib_node_type;
27
28/**
29 * Pool of ABF objects
30 */
31static abf_policy_t *abf_policy_pool;
32
33/**
34 * DB of ABF policy objects
35 *  - policy ID to index conversion.
36 */
37static uword *abf_policy_db;
38
39
40abf_policy_t *
41abf_policy_get (u32 index)
42{
43  return (pool_elt_at_index (abf_policy_pool, index));
44}
45
46static u32
47abf_policy_get_index (const abf_policy_t * abf)
48{
49  return (abf - abf_policy_pool);
50}
51
52static abf_policy_t *
53abf_policy_find_i (u32 policy_id)
54{
55  u32 api;
56
57  api = abf_policy_find (policy_id);
58
59  if (INDEX_INVALID != api)
60    return (abf_policy_get (api));
61
62  return (NULL);
63}
64
65u32
66abf_policy_find (u32 policy_id)
67{
68  uword *p;
69
70  p = hash_get (abf_policy_db, policy_id);
71
72  if (NULL != p)
73    return (p[0]);
74
75  return (INDEX_INVALID);
76}
77
78
79void
80abf_policy_update (u32 policy_id,
81		   u32 acl_index, const fib_route_path_t * rpaths)
82{
83  abf_policy_t *ap;
84  u32 api;
85
86  api = abf_policy_find (policy_id);
87
88  if (INDEX_INVALID == api)
89    {
90      /*
91       * create a new policy
92       */
93      pool_get (abf_policy_pool, ap);
94
95      api = ap - abf_policy_pool;
96      fib_node_init (&ap->ap_node, abf_policy_fib_node_type);
97      ap->ap_acl = acl_index;
98      ap->ap_id = policy_id;
99      ap->ap_pl = fib_path_list_create ((FIB_PATH_LIST_FLAG_SHARED |
100					 FIB_PATH_LIST_FLAG_NO_URPF), rpaths);
101
102      /*
103       * become a child of the path list so we get poked when
104       * the forwarding changes.
105       */
106      ap->ap_sibling = fib_path_list_child_add (ap->ap_pl,
107						abf_policy_fib_node_type,
108						api);
109
110      /*
111       * add this new policy to the DB
112       */
113      hash_set (abf_policy_db, policy_id, api);
114
115      /*
116       * take a lock on behalf of the CLI/API creation
117       */
118      fib_node_lock (&ap->ap_node);
119    }
120  else
121    {
122      /*
123       * update an existing policy.
124       * - add the path to the path-list and swap our ancestry
125       * - backwalk to poke all attachments to update
126       */
127      fib_node_index_t old_pl;
128
129      ap = abf_policy_get (api);
130      old_pl = ap->ap_pl;
131
132      if (FIB_NODE_INDEX_INVALID != old_pl)
133	{
134	  ap->ap_pl = fib_path_list_copy_and_path_add (old_pl,
135						       (FIB_PATH_LIST_FLAG_SHARED
136							|
137							FIB_PATH_LIST_FLAG_NO_URPF),
138						       rpaths);
139	  fib_path_list_child_remove (old_pl, ap->ap_sibling);
140	}
141      else
142	{
143	  ap->ap_pl = fib_path_list_create ((FIB_PATH_LIST_FLAG_SHARED |
144					     FIB_PATH_LIST_FLAG_NO_URPF),
145					    rpaths);
146	}
147
148      ap->ap_sibling = fib_path_list_child_add (ap->ap_pl,
149						abf_policy_fib_node_type,
150						api);
151
152      fib_node_back_walk_ctx_t ctx = {
153	.fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE,
154      };
155
156      fib_walk_sync (abf_policy_fib_node_type, api, &ctx);
157    }
158}
159
160static void
161abf_policy_destroy (abf_policy_t * ap)
162{
163  /*
164   * this ABF should not be a sibling on the path list, since
165   * that was removed when the API config went
166   */
167  ASSERT (ap->ap_sibling == ~0);
168  ASSERT (ap->ap_pl == FIB_NODE_INDEX_INVALID);
169
170  hash_unset (abf_policy_db, ap->ap_id);
171  pool_put (abf_policy_pool, ap);
172}
173
174int
175abf_policy_delete (u32 policy_id, const fib_route_path_t * rpaths)
176{
177  abf_policy_t *ap;
178  u32 api;
179
180  api = abf_policy_find (policy_id);
181
182  if (INDEX_INVALID == api)
183    {
184      /*
185       * no such policy
186       */
187      return (-1);
188    }
189  else
190    {
191      /*
192       * update an existing policy.
193       * - add the path to the path-list and swap our ancestry
194       * - backwalk to poke all attachments to update
195       */
196      fib_node_index_t old_pl;
197
198      ap = abf_policy_get (api);
199      old_pl = ap->ap_pl;
200
201      fib_path_list_lock (old_pl);
202      ap->ap_pl =
203	fib_path_list_copy_and_path_remove (ap->ap_pl,
204					    (FIB_PATH_LIST_FLAG_SHARED |
205					     FIB_PATH_LIST_FLAG_NO_URPF),
206					    rpaths);
207
208      fib_path_list_child_remove (old_pl, ap->ap_sibling);
209      ap->ap_sibling = ~0;
210
211      if (FIB_NODE_INDEX_INVALID == ap->ap_pl)
212	{
213	  /*
214	   * no more paths on this policy. It's toast
215	   * remove the CLI/API's lock
216	   */
217	  fib_node_unlock (&ap->ap_node);
218	}
219      else
220	{
221	  ap->ap_sibling = fib_path_list_child_add (ap->ap_pl,
222						    abf_policy_fib_node_type,
223						    api);
224
225	  fib_node_back_walk_ctx_t ctx = {
226	    .fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE,
227	  };
228
229	  fib_walk_sync (abf_policy_fib_node_type, api, &ctx);
230	}
231      fib_path_list_unlock (old_pl);
232    }
233
234  return (0);
235}
236
237static clib_error_t *
238abf_policy_cmd (vlib_main_t * vm,
239		unformat_input_t * main_input, vlib_cli_command_t * cmd)
240{
241  unformat_input_t _line_input, *line_input = &_line_input;
242  u32 acl_index, policy_id;
243  fib_route_path_t *rpaths = NULL, rpath;
244  u32 is_del;
245
246  is_del = 0;
247  acl_index = INDEX_INVALID;
248  policy_id = INDEX_INVALID;
249
250  /* Get a line of input. */
251  if (!unformat_user (main_input, unformat_line_input, line_input))
252    return 0;
253
254  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
255    {
256      if (unformat (line_input, "acl %d", &acl_index))
257	;
258      else if (unformat (line_input, "id %d", &policy_id))
259	;
260      else if (unformat (line_input, "del"))
261	is_del = 1;
262      else if (unformat (line_input, "add"))
263	is_del = 0;
264      else if (unformat (line_input, "via %U",
265			 unformat_fib_route_path, &rpath))
266	vec_add1 (rpaths, rpath);
267      else
268	return (clib_error_return (0, "unknown input '%U'",
269				   format_unformat_error, line_input));
270    }
271
272  if (INDEX_INVALID == policy_id)
273    {
274      vlib_cli_output (vm, "Specify a Policy ID");
275      return 0;
276    }
277
278  if (!is_del)
279    {
280      if (INDEX_INVALID == acl_index)
281	{
282	  vlib_cli_output (vm, "ACL index must be set");
283	  return 0;
284	}
285
286      abf_policy_update (policy_id, acl_index, rpaths);
287    }
288  else
289    {
290      abf_policy_delete (policy_id, rpaths);
291    }
292
293  unformat_free (line_input);
294  return (NULL);
295}
296
297/* *INDENT-OFF* */
298/**
299 * Create an ABF policy.
300 */
301VLIB_CLI_COMMAND (abf_policy_cmd_node, static) = {
302  .path = "abf policy",
303  .function = abf_policy_cmd,
304  .short_help = "abf policy [add|del] id <index> acl <index> via ...",
305  .is_mp_safe = 1,
306};
307/* *INDENT-ON* */
308
309static u8 *
310format_abf (u8 * s, va_list * args)
311{
312  abf_policy_t *ap = va_arg (*args, abf_policy_t *);
313
314  s = format (s, "abf:[%d]: policy:%d acl:%d",
315	      ap - abf_policy_pool, ap->ap_id, ap->ap_acl);
316  s = format (s, "\n ");
317  if (FIB_NODE_INDEX_INVALID == ap->ap_pl)
318    {
319      s = format (s, "no forwarding");
320    }
321  else
322    {
323      s = fib_path_list_format (ap->ap_pl, s);
324    }
325
326  return (s);
327}
328
329void
330abf_policy_walk (abf_policy_walk_cb_t cb, void *ctx)
331{
332  u32 api;
333
334  /* *INDENT-OFF* */
335  pool_foreach_index(api, abf_policy_pool,
336  ({
337    if (!cb(api, ctx))
338      break;
339  }));
340  /* *INDENT-ON* */
341}
342
343static clib_error_t *
344abf_show_policy_cmd (vlib_main_t * vm,
345		     unformat_input_t * input, vlib_cli_command_t * cmd)
346{
347  u32 policy_id;
348  abf_policy_t *ap;
349
350  policy_id = INDEX_INVALID;
351
352  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
353    {
354      if (unformat (input, "%d", &policy_id))
355	;
356      else
357	return (clib_error_return (0, "unknown input '%U'",
358				   format_unformat_error, input));
359    }
360
361  if (INDEX_INVALID == policy_id)
362    {
363      /* *INDENT-OFF* */
364      pool_foreach(ap, abf_policy_pool,
365      ({
366        vlib_cli_output(vm, "%U", format_abf, ap);
367      }));
368      /* *INDENT-ON* */
369    }
370  else
371    {
372      ap = abf_policy_find_i (policy_id);
373
374      if (NULL != ap)
375	vlib_cli_output (vm, "%U", format_abf, ap);
376      else
377	vlib_cli_output (vm, "Invalid policy ID:%d", policy_id);
378    }
379
380  return (NULL);
381}
382
383/* *INDENT-OFF* */
384VLIB_CLI_COMMAND (abf_policy_show_policy_cmd_node, static) = {
385  .path = "show abf policy",
386  .function = abf_show_policy_cmd,
387  .short_help = "show abf policy <value>",
388  .is_mp_safe = 1,
389};
390/* *INDENT-ON* */
391
392static fib_node_t *
393abf_policy_get_node (fib_node_index_t index)
394{
395  abf_policy_t *ap = abf_policy_get (index);
396  return (&(ap->ap_node));
397}
398
399static abf_policy_t *
400abf_policy_get_from_node (fib_node_t * node)
401{
402  return ((abf_policy_t *) (((char *) node) -
403			    STRUCT_OFFSET_OF (abf_policy_t, ap_node)));
404}
405
406static void
407abf_policy_last_lock_gone (fib_node_t * node)
408{
409  abf_policy_destroy (abf_policy_get_from_node (node));
410}
411
412/*
413 * A back walk has reached this ABF policy
414 */
415static fib_node_back_walk_rc_t
416abf_policy_back_walk_notify (fib_node_t * node,
417			     fib_node_back_walk_ctx_t * ctx)
418{
419  /*
420   * re-stack the fmask on the n-eos of the via
421   */
422  abf_policy_t *abf = abf_policy_get_from_node (node);
423
424  /*
425   * propagate further up the graph.
426   * we can do this synchronously since the fan out is small.
427   */
428  fib_walk_sync (abf_policy_fib_node_type, abf_policy_get_index (abf), ctx);
429
430  return (FIB_NODE_BACK_WALK_CONTINUE);
431}
432
433/*
434 * The BIER fmask's graph node virtual function table
435 */
436static const fib_node_vft_t abf_policy_vft = {
437  .fnv_get = abf_policy_get_node,
438  .fnv_last_lock = abf_policy_last_lock_gone,
439  .fnv_back_walk = abf_policy_back_walk_notify,
440};
441
442static clib_error_t *
443abf_policy_init (vlib_main_t * vm)
444{
445  abf_policy_fib_node_type = fib_node_register_new_type (&abf_policy_vft);
446
447  return (NULL);
448}
449
450VLIB_INIT_FUNCTION (abf_policy_init);
451
452/*
453 * fd.io coding-style-patch-verification: ON
454 *
455 * Local Variables:
456 * eval: (c-set-style "gnu")
457 * End:
458 */
459