libnl  3.5.0
class.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * lib/route/class.c Traffic Classes
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation version 2.1
8  * of the License.
9  *
10  * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
11  */
12 
13 /**
14  * @ingroup tc
15  * @defgroup class Traffic Classes
16  * @{
17  */
18 
19 #include <netlink-private/netlink.h>
20 #include <netlink-private/tc.h>
21 #include <netlink/netlink.h>
22 #include <netlink-private/route/tc-api.h>
23 #include <netlink/route/class.h>
24 #include <netlink/route/qdisc.h>
25 #include <netlink/route/classifier.h>
26 #include <netlink/utils.h>
27 
28 static struct nl_cache_ops rtnl_class_ops;
29 static struct nl_object_ops class_obj_ops;
30 
31 static void class_dump_details(struct rtnl_tc *tc, struct nl_dump_params *p)
32 {
33  struct rtnl_class *class = (struct rtnl_class *) tc;
34  char buf[32];
35 
36  if (class->c_info)
37  nl_dump(p, "child-qdisc %s ",
38  rtnl_tc_handle2str(class->c_info, buf, sizeof(buf)));
39 }
40 
41 
42 static int class_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
43  struct nlmsghdr *nlh, struct nl_parser_param *pp)
44 {
45  struct rtnl_class *class;
46  int err;
47 
48  if (!(class = rtnl_class_alloc()))
49  return -NLE_NOMEM;
50 
51  if ((err = rtnl_tc_msg_parse(nlh, TC_CAST(class))) < 0)
52  goto errout;
53 
54  err = pp->pp_cb(OBJ_CAST(class), pp);
55 errout:
56  rtnl_class_put(class);
57 
58  return err;
59 }
60 
61 static int class_request_update(struct nl_cache *cache, struct nl_sock *sk)
62 {
63  struct tcmsg tchdr = {
64  .tcm_family = AF_UNSPEC,
65  .tcm_ifindex = cache->c_iarg1,
66  };
67 
68  return nl_send_simple(sk, RTM_GETTCLASS, NLM_F_DUMP, &tchdr,
69  sizeof(tchdr));
70 }
71 
72 /**
73  * @name Allocation/Freeing
74  * @{
75  */
76 
77 struct rtnl_class *rtnl_class_alloc(void)
78 {
79  struct rtnl_tc *tc;
80 
81  tc = TC_CAST(nl_object_alloc(&class_obj_ops));
82  if (tc)
83  tc->tc_type = RTNL_TC_TYPE_CLASS;
84 
85  return (struct rtnl_class *) tc;
86 }
87 
88 void rtnl_class_put(struct rtnl_class *class)
89 {
90  nl_object_put((struct nl_object *) class);
91 }
92 
93 /** @} */
94 
95 
96 /**
97  * @name Addition/Modification/Deletion
98  * @{
99  */
100 
101 static int class_build(struct rtnl_class *class, int type, int flags,
102  struct nl_msg **result)
103 {
104  uint32_t needed = TCA_ATTR_PARENT | TCA_ATTR_HANDLE;
105 
106  if ((class->ce_mask & needed) == needed &&
107  TC_H_MAJ(class->c_parent) && TC_H_MAJ(class->c_handle) &&
108  TC_H_MAJ(class->c_parent) != TC_H_MAJ(class->c_handle)) {
109  APPBUG("TC_H_MAJ(parent) must match TC_H_MAJ(handle)");
110  return -NLE_INVAL;
111  }
112 
113  return rtnl_tc_msg_build(TC_CAST(class), type, flags, result);
114 }
115 
116 /**
117  * Build a netlink message requesting the addition of a traffic class
118  * @arg class Traffic class to add
119  * @arg flags Additional netlink message flags
120  * @arg result Pointer to store resulting netlink message
121  *
122  * The behaviour of this function is identical to rtnl_class_add() with
123  * the exception that it will not send the message but return it int the
124  * provided return pointer instead.
125  *
126  * @see rtnl_class_add()
127  *
128  * @return 0 on success or a negative error code.
129  */
130 int rtnl_class_build_add_request(struct rtnl_class *class, int flags,
131  struct nl_msg **result)
132 {
133  return class_build(class, RTM_NEWTCLASS, flags, result);
134 }
135 
136 /**
137  * Add/Update traffic class
138  * @arg sk Netlink socket
139  * @arg class Traffic class to add
140  * @arg flags Additional netlink message flags
141  *
142  * Builds a \c RTM_NEWTCLASS netlink message requesting the addition
143  * of a new traffic class and sends the message to the kernel. The
144  * configuration of the traffic class is derived from the attributes
145  * of the specified traffic class.
146  *
147  * The following flags may be specified:
148  * - \c NLM_F_CREATE: Create traffic class if it does not exist,
149  * otherwise -NLE_OBJ_NOTFOUND is returned.
150  * - \c NLM_F_EXCL: Return -NLE_EXISTS if a traffic class with
151  * matching handle exists already.
152  *
153  * Existing traffic classes with matching handles will be updated,
154  * unless the flag \c NLM_F_EXCL is specified. If no matching traffic
155  * class exists, it will be created if the flag \c NLM_F_CREATE is set,
156  * otherwise the error -NLE_OBJ_NOTFOUND is returned.
157  *
158  * If the parent qdisc does not support classes, the error
159  * \c NLE_OPNOTSUPP is returned.
160  *
161  * After sending, the function will wait for the ACK or an eventual
162  * error message to be received and will therefore block until the
163  * operation has been completed.
164  *
165  * @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
166  * this function to return immediately after sending. In this case,
167  * it is the responsibility of the caller to handle any error
168  * messages returned.
169  *
170  * @return 0 on success or a negative error code.
171  */
172 int rtnl_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags)
173 {
174  struct nl_msg *msg;
175  int err;
176 
177  if ((err = rtnl_class_build_add_request(class, flags, &msg)) < 0)
178  return err;
179 
180  return nl_send_sync(sk, msg);
181 }
182 
183 /**
184  * Build netlink message requesting the deletion of a traffic class
185  * @arg class Traffic class to delete
186  * @arg result Pointer to store resulting netlink message
187  *
188  * The behaviour of this function is identical to rtnl_class_delete() with
189  * the exception that it will not send the message but return it in the
190  * provided return pointer instead.
191  *
192  * @see rtnl_class_delete()
193  *
194  * @return 0 on success or a negative error code.
195  */
196 int rtnl_class_build_delete_request(struct rtnl_class *class, struct nl_msg **result)
197 {
198  struct nl_msg *msg;
199  struct tcmsg tchdr;
200  uint32_t required = TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE;
201 
202  if ((class->ce_mask & required) != required) {
203  APPBUG("ifindex and handle must be specified");
204  return -NLE_MISSING_ATTR;
205  }
206 
207  if (!(msg = nlmsg_alloc_simple(RTM_DELTCLASS, 0)))
208  return -NLE_NOMEM;
209 
210  memset(&tchdr, 0, sizeof(tchdr));
211  tchdr.tcm_family = AF_UNSPEC;
212  tchdr.tcm_ifindex = class->c_ifindex;
213  tchdr.tcm_handle = class->c_handle;
214 
215  if (class->ce_mask & TCA_ATTR_PARENT)
216  tchdr.tcm_parent = class->c_parent;
217 
218  if (nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO) < 0) {
219  nlmsg_free(msg);
220  return -NLE_MSGSIZE;
221  }
222 
223  *result = msg;
224  return 0;
225 }
226 
227 /**
228  * Delete traffic class
229  * @arg sk Netlink socket
230  * @arg class Traffic class to delete
231  *
232  * Builds a \c RTM_DELTCLASS netlink message requesting the deletion
233  * of a traffic class and sends the message to the kernel.
234  *
235  * The message is constructed out of the following attributes:
236  * - \c ifindex and \c handle (required)
237  * - \c parent (optional, must match if provided)
238  *
239  * All other class attributes including all class type specific
240  * attributes are ignored.
241  *
242  * After sending, the function will wait for the ACK or an eventual
243  * error message to be received and will therefore block until the
244  * operation has been completed.
245  *
246  * @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
247  * this function to return immediately after sending. In this case,
248  * it is the responsibility of the caller to handle any error
249  * messages returned.
250  *
251  * @return 0 on success or a negative error code.
252  */
253 int rtnl_class_delete(struct nl_sock *sk, struct rtnl_class *class)
254 {
255  struct nl_msg *msg;
256  int err;
257 
258  if ((err = rtnl_class_build_delete_request(class, &msg)) < 0)
259  return err;
260 
261  return nl_send_sync(sk, msg);
262 }
263 
264 /** @} */
265 
266 /**
267  * @name Leaf Qdisc
268  * @{
269  */
270 
271 /**
272  * Lookup the leaf qdisc of a traffic class
273  * @arg class the parent traffic class
274  * @arg cache a qdisc cache allocated using rtnl_qdisc_alloc_cache()
275  *
276  * @return Matching Qdisc or NULL if the traffic class has no leaf qdisc
277  */
278 struct rtnl_qdisc *rtnl_class_leaf_qdisc(struct rtnl_class *class,
279  struct nl_cache *cache)
280 {
281  struct rtnl_qdisc *leaf;
282 
283  if (!class->c_info)
284  return NULL;
285 
286  leaf = rtnl_qdisc_get_by_parent(cache, class->c_ifindex,
287  class->c_handle);
288  if (!leaf || leaf->q_handle != class->c_info)
289  return NULL;
290 
291  return leaf;
292 }
293 
294 /** @} */
295 
296 /**
297  * @name Cache Related Functions
298  * @{
299  */
300 
301 /**
302  * Allocate a cache and fill it with all configured traffic classes
303  * @arg sk Netlink socket
304  * @arg ifindex Interface index of the network device
305  * @arg result Pointer to store the created cache
306  *
307  * Allocates a new traffic class cache and fills it with a list of all
308  * configured traffic classes on a specific network device. Release the
309  * cache with nl_cache_free().
310  *
311  * @return 0 on success or a negative error code.
312  */
313 int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex,
314  struct nl_cache **result)
315 {
316  struct nl_cache * cache;
317  int err;
318 
319  if (!ifindex) {
320  APPBUG("ifindex must be specified");
321  return -NLE_INVAL;
322  }
323 
324  if (!(cache = nl_cache_alloc(&rtnl_class_ops)))
325  return -NLE_NOMEM;
326 
327  cache->c_iarg1 = ifindex;
328 
329  if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
330  nl_cache_free(cache);
331  return err;
332  }
333 
334  *result = cache;
335  return 0;
336 }
337 
338 /**
339  * Search traffic class by interface index and handle
340  * @arg cache Traffic class cache
341  * @arg ifindex Interface index
342  * @arg handle ID of traffic class
343  *
344  * Searches a traffic class cache previously allocated with
345  * rtnl_class_alloc_cache() and searches for a traffi class matching
346  * the interface index and handle.
347  *
348  * The reference counter is incremented before returning the traffic
349  * class, therefore the reference must be given back with rtnl_class_put()
350  * after usage.
351  *
352  * @return Traffic class or NULL if no match was found.
353  */
354 struct rtnl_class *rtnl_class_get(struct nl_cache *cache, int ifindex,
355  uint32_t handle)
356 {
357  struct rtnl_class *class;
358 
359  if (cache->c_ops != &rtnl_class_ops)
360  return NULL;
361 
362  nl_list_for_each_entry(class, &cache->c_items, ce_list) {
363  if (class->c_handle == handle && class->c_ifindex == ifindex) {
364  nl_object_get((struct nl_object *) class);
365  return class;
366  }
367  }
368  return NULL;
369 }
370 
371 /**
372  * Search class by interface index and parent
373  * @arg cache Traffic class cache
374  * @arg ifindex Interface index
375  * @arg parent Handle of parent qdisc
376  *
377  * Searches a class cache previously allocated with rtnl_class_alloc_cache()
378  * and searches for a class matching the interface index and parent qdisc.
379  *
380  * The reference counter is incremented before returning the class, therefore
381  * the reference must be given back with rtnl_class_put() after usage.
382  *
383  * @return pointer to class inside the cache or NULL if no match was found.
384  */
385 struct rtnl_class *rtnl_class_get_by_parent(struct nl_cache *cache, int ifindex,
386  uint32_t parent)
387 {
388  struct rtnl_class *class;
389 
390  if (cache->c_ops != &rtnl_class_ops)
391  return NULL;
392 
393  nl_list_for_each_entry(class, &cache->c_items, ce_list) {
394  if (class->c_parent == parent && class->c_ifindex == ifindex) {
395  nl_object_get((struct nl_object *) class);
396  return class;
397  }
398  }
399 
400  return NULL;
401 }
402 
403 /** @} */
404 
405 /**
406  * @name Deprecated Functions
407  * @{
408  */
409 
410 /**
411  * Call a callback for each child of a class
412  *
413  * @deprecated Use of this function is deprecated, it does not allow
414  * to handle the out of memory situation that can occur.
415  */
416 void rtnl_class_foreach_child(struct rtnl_class *class, struct nl_cache *cache,
417  void (*cb)(struct nl_object *, void *), void *arg)
418 {
419  struct rtnl_class *filter;
420 
421  filter = rtnl_class_alloc();
422  if (!filter)
423  return;
424 
425  rtnl_tc_set_parent(TC_CAST(filter), class->c_handle);
426  rtnl_tc_set_ifindex(TC_CAST(filter), class->c_ifindex);
427  rtnl_tc_set_kind(TC_CAST(filter), class->c_kind);
428 
429  nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg);
430  rtnl_class_put(filter);
431 }
432 
433 /**
434  * Call a callback for each classifier attached to the class
435  *
436  * @deprecated Use of this function is deprecated, it does not allow
437  * to handle the out of memory situation that can occur.
438  */
439 void rtnl_class_foreach_cls(struct rtnl_class *class, struct nl_cache *cache,
440  void (*cb)(struct nl_object *, void *), void *arg)
441 {
442  struct rtnl_cls *filter;
443 
444  filter = rtnl_cls_alloc();
445  if (!filter)
446  return;
447 
448  rtnl_tc_set_ifindex((struct rtnl_tc *) filter, class->c_ifindex);
449  rtnl_tc_set_parent((struct rtnl_tc *) filter, class->c_parent);
450 
451  nl_cache_foreach_filter(cache, (struct nl_object *) filter, cb, arg);
452  rtnl_cls_put(filter);
453 }
454 
455 /** @} */
456 
457 static struct rtnl_tc_type_ops class_ops = {
458  .tt_type = RTNL_TC_TYPE_CLASS,
459  .tt_dump_prefix = "class",
460  .tt_dump = {
461  [NL_DUMP_DETAILS] = class_dump_details,
462  },
463 };
464 
465 static struct nl_object_ops class_obj_ops = {
466  .oo_name = "route/class",
467  .oo_size = sizeof(struct rtnl_class),
468  .oo_free_data = rtnl_tc_free_data,
469  .oo_clone = rtnl_tc_clone,
470  .oo_dump = {
471  [NL_DUMP_LINE] = rtnl_tc_dump_line,
472  [NL_DUMP_DETAILS] = rtnl_tc_dump_details,
473  [NL_DUMP_STATS] = rtnl_tc_dump_stats,
474  },
475  .oo_compare = rtnl_tc_compare,
476  .oo_id_attrs = (TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE),
477 };
478 
479 static struct nl_cache_ops rtnl_class_ops = {
480  .co_name = "route/class",
481  .co_hdrsize = sizeof(struct tcmsg),
482  .co_msgtypes = {
483  { RTM_NEWTCLASS, NL_ACT_NEW, "new" },
484  { RTM_DELTCLASS, NL_ACT_DEL, "del" },
485  { RTM_GETTCLASS, NL_ACT_GET, "get" },
486  END_OF_MSGTYPES_LIST,
487  },
488  .co_protocol = NETLINK_ROUTE,
489  .co_groups = tc_groups,
490  .co_request_update = &class_request_update,
491  .co_msg_parser = &class_msg_parser,
492  .co_obj_ops = &class_obj_ops,
493 };
494 
495 static void __init class_init(void)
496 {
497  rtnl_tc_type_register(&class_ops);
498  nl_cache_mngt_register(&rtnl_class_ops);
499 }
500 
501 static void __exit class_exit(void)
502 {
503  nl_cache_mngt_unregister(&rtnl_class_ops);
504  rtnl_tc_type_unregister(&class_ops);
505 }
506 
507 /** @} */
Dump object briefly on one line.
Definition: types.h:22
struct rtnl_qdisc * rtnl_qdisc_get_by_parent(struct nl_cache *cache, int ifindex, uint32_t parent)
Search qdisc by interface index and parent.
Definition: qdisc.c:388
void nlmsg_free(struct nl_msg *msg)
Release a reference from an netlink message.
Definition: msg.c:565
int rtnl_tc_set_kind(struct rtnl_tc *tc, const char *kind)
Define the type of traffic control object.
Definition: tc.c:530
struct nl_object * nl_object_alloc(struct nl_object_ops *ops)
Allocate a new object of kind specified by the operations handle.
Definition: object.c:55
int nl_cache_mngt_unregister(struct nl_cache_ops *ops)
Unregister a set of cache operations.
Definition: cache_mngt.c:288
void nl_object_get(struct nl_object *obj)
Acquire a reference on a object.
Definition: object.c:205
int nl_send_sync(struct nl_sock *sk, struct nl_msg *msg)
Finalize and transmit Netlink message and wait for ACK or error message.
Definition: nl.c:549
struct rtnl_qdisc * rtnl_class_leaf_qdisc(struct rtnl_class *class, struct nl_cache *cache)
Lookup the leaf qdisc of a traffic class.
Definition: class.c:278
int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex, struct nl_cache **result)
Allocate a cache and fill it with all configured traffic classes.
Definition: class.c:313
void rtnl_tc_set_parent(struct rtnl_tc *tc, uint32_t parent)
Set the parent identifier of a traffic control object.
Definition: tc.c:508
void nl_cache_foreach_filter(struct nl_cache *cache, struct nl_object *filter, void(*cb)(struct nl_object *, void *), void *arg)
Call a callback on each element of the cache (filtered).
Definition: cache.c:1283
Dump all attributes but no statistics.
Definition: types.h:23
void nl_cache_free(struct nl_cache *cache)
Free a cache.
Definition: cache.c:409
int nl_cache_mngt_register(struct nl_cache_ops *ops)
Register a set of cache operations.
Definition: cache_mngt.c:253
void rtnl_class_foreach_child(struct rtnl_class *class, struct nl_cache *cache, void(*cb)(struct nl_object *, void *), void *arg)
Call a callback for each child of a class.
Definition: class.c:416
void rtnl_tc_set_ifindex(struct rtnl_tc *tc, int ifindex)
Set interface index of traffic control object.
Definition: tc.c:279
#define TC_CAST(ptr)
Macro to cast qdisc/class/classifier to tc object.
Definition: tc.h:56
struct rtnl_class * rtnl_class_get(struct nl_cache *cache, int ifindex, uint32_t handle)
Search traffic class by interface index and handle.
Definition: class.c:354
int rtnl_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags)
Add/Update traffic class.
Definition: class.c:172
int nl_send_simple(struct nl_sock *sk, int type, int flags, void *buf, size_t size)
Construct and transmit a Netlink message.
Definition: nl.c:581
int nlmsg_append(struct nl_msg *n, void *data, size_t len, int pad)
Append data to tail of a netlink message.
Definition: msg.c:449
int nl_cache_refill(struct nl_sock *sk, struct nl_cache *cache)
(Re)fill a cache with the contents in the kernel.
Definition: cache.c:1041
void nl_object_put(struct nl_object *obj)
Release a reference from an object.
Definition: object.c:216
struct nl_msg * nlmsg_alloc_simple(int nlmsgtype, int flags)
Allocate a new netlink message.
Definition: msg.c:348
struct rtnl_class * rtnl_class_get_by_parent(struct nl_cache *cache, int ifindex, uint32_t parent)
Search class by interface index and parent.
Definition: class.c:385
char * rtnl_tc_handle2str(uint32_t handle, char *buf, size_t len)
Convert a traffic control handle to a character string (Reentrant).
Definition: classid.c:110
Dumping parameters.
Definition: types.h:33
int rtnl_class_build_delete_request(struct rtnl_class *class, struct nl_msg **result)
Build netlink message requesting the deletion of a traffic class.
Definition: class.c:196
int rtnl_class_delete(struct nl_sock *sk, struct rtnl_class *class)
Delete traffic class.
Definition: class.c:253
void nl_dump(struct nl_dump_params *params, const char *fmt,...)
Dump a formatted character string.
Definition: utils.c:962
int rtnl_class_build_add_request(struct rtnl_class *class, int flags, struct nl_msg **result)
Build a netlink message requesting the addition of a traffic class.
Definition: class.c:130
Dump all attributes including statistics.
Definition: types.h:24
struct nl_cache * nl_cache_alloc(struct nl_cache_ops *ops)
Allocate new cache.
Definition: cache.c:184
void rtnl_class_foreach_cls(struct rtnl_class *class, struct nl_cache *cache, void(*cb)(struct nl_object *, void *), void *arg)
Call a callback for each classifier attached to the class.
Definition: class.c:439