1 /*
2 * lib/route/qdisc.c Queueing Disciplines
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation version 2.1
7 * of the License.
8 *
9 * Copyright (c) 2003-2011 Thomas Graf <tgraf@suug.ch>
10 */
11
12 /**
13 * @ingroup tc
14 * @defgroup qdisc Queueing Disciplines
15 * @{
16 */
17
18 #include <netlink-private/netlink.h>
19 #include <netlink-private/tc.h>
20 #include <netlink/netlink.h>
21 #include <netlink/utils.h>
22 #include <netlink/route/link.h>
23 #include <netlink-private/route/tc-api.h>
24 #include <netlink/route/qdisc.h>
25 #include <netlink/route/class.h>
26 #include <netlink/route/classifier.h>
27
28 static struct nl_cache_ops rtnl_qdisc_ops;
29 static struct nl_object_ops qdisc_obj_ops;
30
qdisc_msg_parser(struct nl_cache_ops * ops,struct sockaddr_nl * who,struct nlmsghdr * n,struct nl_parser_param * pp)31 static int qdisc_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
32 struct nlmsghdr *n, struct nl_parser_param *pp)
33 {
34 struct rtnl_qdisc *qdisc;
35 int err;
36
37 if (!(qdisc = rtnl_qdisc_alloc()))
38 return -NLE_NOMEM;
39
40 if ((err = rtnl_tc_msg_parse(n, TC_CAST(qdisc))) < 0)
41 goto errout;
42
43 err = pp->pp_cb(OBJ_CAST(qdisc), pp);
44 errout:
45 rtnl_qdisc_put(qdisc);
46
47 return err;
48 }
49
qdisc_request_update(struct nl_cache * c,struct nl_sock * sk)50 static int qdisc_request_update(struct nl_cache *c, struct nl_sock *sk)
51 {
52 struct tcmsg tchdr = {
53 .tcm_family = AF_UNSPEC,
54 .tcm_ifindex = c->c_iarg1,
55 };
56
57 return nl_send_simple(sk, RTM_GETQDISC, NLM_F_DUMP, &tchdr,
58 sizeof(tchdr));
59 }
60
61 /**
62 * @name Allocation/Freeing
63 * @{
64 */
65
rtnl_qdisc_alloc(void)66 struct rtnl_qdisc *rtnl_qdisc_alloc(void)
67 {
68 struct rtnl_tc *tc;
69
70 tc = TC_CAST(nl_object_alloc(&qdisc_obj_ops));
71 if (tc)
72 tc->tc_type = RTNL_TC_TYPE_QDISC;
73
74 return (struct rtnl_qdisc *) tc;
75 }
76
rtnl_qdisc_put(struct rtnl_qdisc * qdisc)77 void rtnl_qdisc_put(struct rtnl_qdisc *qdisc)
78 {
79 nl_object_put((struct nl_object *) qdisc);
80 }
81
82 /** @} */
83
84 /**
85 * @name Addition / Modification / Deletion
86 * @{
87 */
88
build_qdisc_msg(struct rtnl_qdisc * qdisc,int type,int flags,struct nl_msg ** result)89 static int build_qdisc_msg(struct rtnl_qdisc *qdisc, int type, int flags,
90 struct nl_msg **result)
91 {
92 if (!(qdisc->ce_mask & TCA_ATTR_IFINDEX)) {
93 APPBUG("ifindex must be specified");
94 return -NLE_MISSING_ATTR;
95 }
96
97 return rtnl_tc_msg_build(TC_CAST(qdisc), type, flags, result);
98 }
99
100 /**
101 * Build a netlink message requesting the addition of a qdisc
102 * @arg qdisc Qdisc to add
103 * @arg flags Additional netlink message flags
104 * @arg result Pointer to store resulting netlink message
105 *
106 * The behaviour of this function is identical to rtnl_qdisc_add() with
107 * the exception that it will not send the message but return it int the
108 * provided return pointer instead.
109 *
110 * @see rtnl_qdisc_add()
111 *
112 * @return 0 on success or a negative error code.
113 */
rtnl_qdisc_build_add_request(struct rtnl_qdisc * qdisc,int flags,struct nl_msg ** result)114 int rtnl_qdisc_build_add_request(struct rtnl_qdisc *qdisc, int flags,
115 struct nl_msg **result)
116 {
117 if (!(qdisc->ce_mask & (TCA_ATTR_HANDLE | TCA_ATTR_PARENT))) {
118 APPBUG("handle or parent must be specified");
119 return -NLE_MISSING_ATTR;
120 }
121
122 return build_qdisc_msg(qdisc, RTM_NEWQDISC, flags, result);
123 }
124
125 /**
126 * Add qdisc
127 * @arg sk Netlink socket
128 * @arg qdisc Qdisc to add
129 * @arg flags Additional netlink message flags
130 *
131 * Builds a \c RTM_NEWQDISC netlink message requesting the addition
132 * of a new qdisc and sends the message to the kernel. The configuration
133 * of the qdisc is derived from the attributes of the specified qdisc.
134 *
135 * The following flags may be specified:
136 * - \c NLM_F_CREATE: Create qdisc if it does not exist, otherwise
137 * -NLE_OBJ_NOTFOUND is returned.
138 * - \c NLM_F_REPLACE: If another qdisc is already attached to the
139 * parent, replace it even if the handles mismatch.
140 * - \c NLM_F_EXCL: Return -NLE_EXISTS if a qdisc with matching
141 * handle exists already.
142 *
143 * Existing qdiscs with matching handles will be updated, unless the
144 * flag \c NLM_F_EXCL is specified. If their handles do not match, the
145 * error -NLE_EXISTS is returned unless the flag \c NLM_F_REPLACE is
146 * specified in which case the existing qdisc is replaced with the new
147 * one. If no matching qdisc exists, it will be created if the flag
148 * \c NLM_F_CREATE is set, otherwise the error -NLE_OBJ_NOTFOUND is
149 * returned.
150 *
151 * After sending, the function will wait for the ACK or an eventual
152 * error message to be received and will therefore block until the
153 * operation has been completed.
154 *
155 * @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
156 * this function to return immediately after sending. In this case,
157 * it is the responsibility of the caller to handle any error
158 * messages returned.
159 *
160 * @return 0 on success or a negative error code.
161 */
rtnl_qdisc_add(struct nl_sock * sk,struct rtnl_qdisc * qdisc,int flags)162 int rtnl_qdisc_add(struct nl_sock *sk, struct rtnl_qdisc *qdisc, int flags)
163 {
164 struct nl_msg *msg;
165 int err;
166
167 if ((err = rtnl_qdisc_build_add_request(qdisc, flags, &msg)) < 0)
168 return err;
169
170 return nl_send_sync(sk, msg);
171 }
172
173 /**
174 * Build netlink message requesting the update of a qdisc
175 * @arg qdisc Qdisc to update
176 * @arg new Qdisc with updated attributes
177 * @arg flags Additional netlink message flags
178 * @arg result Pointer to store resulting netlink message
179 *
180 * The behaviour of this function is identical to rtnl_qdisc_update() with
181 * the exception that it will not send the message but return it in the
182 * provided return pointer instead.
183 *
184 * @see rtnl_qdisc_update()
185 *
186 * @return 0 on success or a negative error code.
187 */
rtnl_qdisc_build_update_request(struct rtnl_qdisc * qdisc,struct rtnl_qdisc * new,int flags,struct nl_msg ** result)188 int rtnl_qdisc_build_update_request(struct rtnl_qdisc *qdisc,
189 struct rtnl_qdisc *new, int flags,
190 struct nl_msg **result)
191 {
192 if (flags & (NLM_F_CREATE | NLM_F_EXCL)) {
193 APPBUG("NLM_F_CREATE and NLM_F_EXCL may not be used here, "
194 "use rtnl_qdisc_add()");
195 return -NLE_INVAL;
196 }
197
198 if (!(qdisc->ce_mask & TCA_ATTR_IFINDEX)) {
199 APPBUG("ifindex must be specified");
200 return -NLE_MISSING_ATTR;
201 }
202
203 if (!(qdisc->ce_mask & (TCA_ATTR_HANDLE | TCA_ATTR_PARENT))) {
204 APPBUG("handle or parent must be specified");
205 return -NLE_MISSING_ATTR;
206 }
207
208 rtnl_tc_set_ifindex(TC_CAST(new), qdisc->q_ifindex);
209
210 if (qdisc->ce_mask & TCA_ATTR_HANDLE)
211 rtnl_tc_set_handle(TC_CAST(new), qdisc->q_handle);
212
213 if (qdisc->ce_mask & TCA_ATTR_PARENT)
214 rtnl_tc_set_parent(TC_CAST(new), qdisc->q_parent);
215
216 return build_qdisc_msg(new, RTM_NEWQDISC, flags, result);
217 }
218
219 /**
220 * Update qdisc
221 * @arg sk Netlink socket
222 * @arg qdisc Qdisc to update
223 * @arg new Qdisc with updated attributes
224 * @arg flags Additional netlink message flags
225 *
226 * Builds a \c RTM_NEWQDISC netlink message requesting the update
227 * of an existing qdisc and sends the message to the kernel.
228 *
229 * This function is a varation of rtnl_qdisc_add() to update qdiscs
230 * if the qdisc to be updated is available as qdisc object. The
231 * behaviour is identical to the one of rtnl_qdisc_add except that
232 * before constructing the message, it copies the \c ifindex,
233 * \c handle, and \c parent from the original \p qdisc to the \p new
234 * qdisc.
235 *
236 * After sending, the function will wait for the ACK or an eventual
237 * error message to be received and will therefore block until the
238 * operation has been completed.
239 *
240 * @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
241 * this function to return immediately after sending. In this case,
242 * it is the responsibility of the caller to handle any error
243 * messages returned.
244 *
245 * @return 0 on success or a negative error code.
246 */
rtnl_qdisc_update(struct nl_sock * sk,struct rtnl_qdisc * qdisc,struct rtnl_qdisc * new,int flags)247 int rtnl_qdisc_update(struct nl_sock *sk, struct rtnl_qdisc *qdisc,
248 struct rtnl_qdisc *new, int flags)
249 {
250 struct nl_msg *msg;
251 int err;
252
253 err = rtnl_qdisc_build_update_request(qdisc, new, flags, &msg);
254 if (err < 0)
255 return err;
256
257 return nl_send_sync(sk, msg);
258 }
259
260 /**
261 * Build netlink message requesting the deletion of a qdisc
262 * @arg qdisc Qdisc to delete
263 * @arg result Pointer to store resulting netlink message
264 *
265 * The behaviour of this function is identical to rtnl_qdisc_delete() with
266 * the exception that it will not send the message but return it in the
267 * provided return pointer instead.
268 *
269 * @see rtnl_qdisc_delete()
270 *
271 * @return 0 on success or a negative error code.
272 */
rtnl_qdisc_build_delete_request(struct rtnl_qdisc * qdisc,struct nl_msg ** result)273 int rtnl_qdisc_build_delete_request(struct rtnl_qdisc *qdisc,
274 struct nl_msg **result)
275 {
276 struct nl_msg *msg;
277 struct tcmsg tchdr;
278 uint32_t required = TCA_ATTR_IFINDEX | TCA_ATTR_PARENT;
279
280 if ((qdisc->ce_mask & required) != required) {
281 APPBUG("ifindex and parent must be specified");
282 return -NLE_MISSING_ATTR;
283 }
284
285 if (!(msg = nlmsg_alloc_simple(RTM_DELQDISC, 0)))
286 return -NLE_NOMEM;
287
288 memset(&tchdr, 0, sizeof(tchdr));
289
290 tchdr.tcm_family = AF_UNSPEC;
291 tchdr.tcm_ifindex = qdisc->q_ifindex;
292 tchdr.tcm_parent = qdisc->q_parent;
293
294 if (qdisc->ce_mask & TCA_ATTR_HANDLE)
295 tchdr.tcm_handle = qdisc->q_handle;
296
297 if (nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO) < 0)
298 goto nla_put_failure;
299
300 if (qdisc->ce_mask & TCA_ATTR_KIND)
301 NLA_PUT_STRING(msg, TCA_KIND, qdisc->q_kind);
302
303 *result = msg;
304 return 0;
305
306 nla_put_failure:
307 nlmsg_free(msg);
308 return -NLE_MSGSIZE;
309 }
310
311 /**
312 * Delete qdisc
313 * @arg sk Netlink socket
314 * @arg qdisc Qdisc to add
315 *
316 * Builds a \c RTM_NEWQDISC netlink message requesting the deletion
317 * of a qdisc and sends the message to the kernel.
318 *
319 * The message is constructed out of the following attributes:
320 * - \c ifindex and \c parent
321 * - \c handle (optional, must match if provided)
322 * - \c kind (optional, must match if provided)
323 *
324 * All other qdisc attributes including all qdisc type specific
325 * attributes are ignored.
326 *
327 * After sending, the function will wait for the ACK or an eventual
328 * error message to be received and will therefore block until the
329 * operation has been completed.
330 *
331 * @note It is not possible to delete default qdiscs.
332 *
333 * @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
334 * this function to return immediately after sending. In this case,
335 * it is the responsibility of the caller to handle any error
336 * messages returned.
337 *
338 * @return 0 on success or a negative error code.
339 */
rtnl_qdisc_delete(struct nl_sock * sk,struct rtnl_qdisc * qdisc)340 int rtnl_qdisc_delete(struct nl_sock *sk, struct rtnl_qdisc *qdisc)
341 {
342 struct nl_msg *msg;
343 int err;
344
345 if ((err = rtnl_qdisc_build_delete_request(qdisc, &msg)) < 0)
346 return err;
347
348 return nl_send_sync(sk, msg);
349 }
350
351 /** @} */
352
353 /**
354 * @name Cache Related Functions
355 * @{
356 */
357
358 /**
359 * Allocate a cache and fill it with all configured qdiscs
360 * @arg sk Netlink socket
361 * @arg result Pointer to store the created cache
362 *
363 * Allocates a new qdisc cache and fills it with a list of all configured
364 * qdiscs on all network devices. Release the cache with nl_cache_free().
365 *
366 * @return 0 on success or a negative error code.
367 */
rtnl_qdisc_alloc_cache(struct nl_sock * sk,struct nl_cache ** result)368 int rtnl_qdisc_alloc_cache(struct nl_sock *sk, struct nl_cache **result)
369 {
370 return nl_cache_alloc_and_fill(&rtnl_qdisc_ops, sk, result);
371 }
372
373 /**
374 * Search qdisc by interface index and parent
375 * @arg cache Qdisc cache
376 * @arg ifindex Interface index
377 * @arg parent Handle of parent qdisc
378 *
379 * Searches a qdisc cache previously allocated with rtnl_qdisc_alloc_cache()
380 * and searches for a qdisc matching the interface index and parent qdisc.
381 *
382 * The reference counter is incremented before returning the qdisc, therefore
383 * the reference must be given back with rtnl_qdisc_put() after usage.
384 *
385 * @return pointer to qdisc inside the cache or NULL if no match was found.
386 */
rtnl_qdisc_get_by_parent(struct nl_cache * cache,int ifindex,uint32_t parent)387 struct rtnl_qdisc *rtnl_qdisc_get_by_parent(struct nl_cache *cache,
388 int ifindex, uint32_t parent)
389 {
390 struct rtnl_qdisc *q;
391
392 if (cache->c_ops != &rtnl_qdisc_ops)
393 return NULL;
394
395 nl_list_for_each_entry(q, &cache->c_items, ce_list) {
396 if (q->q_parent == parent && q->q_ifindex == ifindex) {
397 nl_object_get((struct nl_object *) q);
398 return q;
399 }
400 }
401
402 return NULL;
403 }
404
405 /**
406 * Search qdisc by interface index and handle
407 * @arg cache Qdisc cache
408 * @arg ifindex Interface index
409 * @arg handle Handle
410 *
411 * Searches a qdisc cache previously allocated with rtnl_qdisc_alloc_cache()
412 * and searches for a qdisc matching the interface index and handle.
413 *
414 * The reference counter is incremented before returning the qdisc, therefore
415 * the reference must be given back with rtnl_qdisc_put() after usage.
416 *
417 * @return Qdisc or NULL if no match was found.
418 */
rtnl_qdisc_get(struct nl_cache * cache,int ifindex,uint32_t handle)419 struct rtnl_qdisc *rtnl_qdisc_get(struct nl_cache *cache, int ifindex,
420 uint32_t handle)
421 {
422 struct rtnl_qdisc *q;
423
424 if (cache->c_ops != &rtnl_qdisc_ops)
425 return NULL;
426
427 nl_list_for_each_entry(q, &cache->c_items, ce_list) {
428 if (q->q_handle == handle && q->q_ifindex == ifindex) {
429 nl_object_get((struct nl_object *) q);
430 return q;
431 }
432 }
433
434 return NULL;
435 }
436
437 /** @} */
438
439 /**
440 * @name Deprecated Functions
441 * @{
442 */
443
444 /**
445 * Call a callback for each child class of a qdisc (deprecated)
446 *
447 * @deprecated Use of this function is deprecated, it does not allow
448 * to handle the out of memory situation that can occur.
449 */
rtnl_qdisc_foreach_child(struct rtnl_qdisc * qdisc,struct nl_cache * cache,void (* cb)(struct nl_object *,void *),void * arg)450 void rtnl_qdisc_foreach_child(struct rtnl_qdisc *qdisc, struct nl_cache *cache,
451 void (*cb)(struct nl_object *, void *), void *arg)
452 {
453 struct rtnl_class *filter;
454
455 filter = rtnl_class_alloc();
456 if (!filter)
457 return;
458
459 rtnl_tc_set_parent(TC_CAST(filter), qdisc->q_handle);
460 rtnl_tc_set_ifindex(TC_CAST(filter), qdisc->q_ifindex);
461 rtnl_tc_set_kind(TC_CAST(filter), qdisc->q_kind);
462
463 nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg);
464
465 rtnl_class_put(filter);
466 }
467
468 /**
469 * Call a callback for each filter attached to the qdisc (deprecated)
470 *
471 * @deprecated Use of this function is deprecated, it does not allow
472 * to handle the out of memory situation that can occur.
473 */
rtnl_qdisc_foreach_cls(struct rtnl_qdisc * qdisc,struct nl_cache * cache,void (* cb)(struct nl_object *,void *),void * arg)474 void rtnl_qdisc_foreach_cls(struct rtnl_qdisc *qdisc, struct nl_cache *cache,
475 void (*cb)(struct nl_object *, void *), void *arg)
476 {
477 struct rtnl_cls *filter;
478
479 if (!(filter = rtnl_cls_alloc()))
480 return;
481
482 rtnl_tc_set_ifindex(TC_CAST(filter), qdisc->q_ifindex);
483 rtnl_tc_set_parent(TC_CAST(filter), qdisc->q_parent);
484
485 nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg);
486 rtnl_cls_put(filter);
487 }
488
489 /**
490 * Build a netlink message requesting the update of a qdisc
491 *
492 * @deprecated Use of this function is deprecated in favour of
493 * rtnl_qdisc_build_update_request() due to the missing
494 * possibility of specifying additional flags.
495 */
rtnl_qdisc_build_change_request(struct rtnl_qdisc * qdisc,struct rtnl_qdisc * new,struct nl_msg ** result)496 int rtnl_qdisc_build_change_request(struct rtnl_qdisc *qdisc,
497 struct rtnl_qdisc *new,
498 struct nl_msg **result)
499 {
500 return rtnl_qdisc_build_update_request(qdisc, new, NLM_F_REPLACE,
501 result);
502 }
503
504 /**
505 * Change attributes of a qdisc
506 *
507 * @deprecated Use of this function is deprecated in favour of
508 * rtnl_qdisc_update() due to the missing possibility of
509 * specifying additional flags.
510 */
rtnl_qdisc_change(struct nl_sock * sk,struct rtnl_qdisc * qdisc,struct rtnl_qdisc * new)511 int rtnl_qdisc_change(struct nl_sock *sk, struct rtnl_qdisc *qdisc,
512 struct rtnl_qdisc *new)
513 {
514 return rtnl_qdisc_update(sk, qdisc, new, NLM_F_REPLACE);
515 }
516
517 /** @} */
518
qdisc_dump_details(struct rtnl_tc * tc,struct nl_dump_params * p)519 static void qdisc_dump_details(struct rtnl_tc *tc, struct nl_dump_params *p)
520 {
521 struct rtnl_qdisc *qdisc = (struct rtnl_qdisc *) tc;
522
523 nl_dump(p, "refcnt %u ", qdisc->q_info);
524 }
525
526 static struct rtnl_tc_type_ops qdisc_ops = {
527 .tt_type = RTNL_TC_TYPE_QDISC,
528 .tt_dump_prefix = "qdisc",
529 .tt_dump = {
530 [NL_DUMP_DETAILS] = qdisc_dump_details,
531 },
532 };
533
534 static struct nl_cache_ops rtnl_qdisc_ops = {
535 .co_name = "route/qdisc",
536 .co_hdrsize = sizeof(struct tcmsg),
537 .co_msgtypes = {
538 { RTM_NEWQDISC, NL_ACT_NEW, "new" },
539 { RTM_DELQDISC, NL_ACT_DEL, "del" },
540 { RTM_GETQDISC, NL_ACT_GET, "get" },
541 END_OF_MSGTYPES_LIST,
542 },
543 .co_protocol = NETLINK_ROUTE,
544 .co_groups = tc_groups,
545 .co_request_update = qdisc_request_update,
546 .co_msg_parser = qdisc_msg_parser,
547 .co_obj_ops = &qdisc_obj_ops,
548 };
549
550 static struct nl_object_ops qdisc_obj_ops = {
551 .oo_name = "route/qdisc",
552 .oo_size = sizeof(struct rtnl_qdisc),
553 .oo_free_data = rtnl_tc_free_data,
554 .oo_clone = rtnl_tc_clone,
555 .oo_dump = {
556 [NL_DUMP_LINE] = rtnl_tc_dump_line,
557 [NL_DUMP_DETAILS] = rtnl_tc_dump_details,
558 [NL_DUMP_STATS] = rtnl_tc_dump_stats,
559 },
560 .oo_compare = rtnl_tc_compare,
561 .oo_id_attrs = (TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE),
562 };
563
qdisc_init(void)564 static void __init qdisc_init(void)
565 {
566 rtnl_tc_type_register(&qdisc_ops);
567 nl_cache_mngt_register(&rtnl_qdisc_ops);
568 }
569
qdisc_exit(void)570 static void __exit qdisc_exit(void)
571 {
572 nl_cache_mngt_unregister(&rtnl_qdisc_ops);
573 rtnl_tc_type_unregister(&qdisc_ops);
574 }
575
576 /** @} */
577