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