class.c revision cfcfca070355b246028df60da79813f09ed65755 
1/*
2 * lib/route/class.c            Queueing 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) 2003-2008 Thomas Graf <tgraf@suug.ch>
10 */
11
12/**
13 * @ingroup tc
14 * @defgroup class Queueing Classes
15 * @{
16 */
17
18#include <netlink-local.h>
19#include <netlink-tc.h>
20#include <netlink/netlink.h>
21#include <netlink/route/tc.h>
22#include <netlink/route/class.h>
23#include <netlink/route/class-modules.h>
24#include <netlink/route/qdisc.h>
25#include <netlink/route/classifier.h>
26#include <netlink/utils.h>
27
28static struct nl_cache_ops rtnl_class_ops;
29
30static int class_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
31			    struct nlmsghdr *n, struct nl_parser_param *pp)
32{
33	int err;
34	struct rtnl_class *class;
35	struct rtnl_class_ops *cops;
36
37	class = rtnl_class_alloc();
38	if (!class) {
39		err = -NLE_NOMEM;
40		goto errout;
41	}
42	class->ce_msgtype = n->nlmsg_type;
43
44	err = tca_msg_parser(n, (struct rtnl_tca *) class);
45	if (err < 0)
46		goto errout_free;
47
48	cops = rtnl_class_lookup_ops(class);
49	if (cops && cops->co_msg_parser) {
50		err = cops->co_msg_parser(class);
51		if (err < 0)
52			goto errout_free;
53	}
54
55	err = pp->pp_cb((struct nl_object *) class, pp);
56errout_free:
57	rtnl_class_put(class);
58errout:
59	return err;
60}
61
62static int class_request_update(struct nl_cache *cache, struct nl_sock *sk)
63{
64	struct tcmsg tchdr = {
65		.tcm_family = AF_UNSPEC,
66		.tcm_ifindex = cache->c_iarg1,
67	};
68
69	return nl_send_simple(sk, RTM_GETTCLASS, NLM_F_DUMP, &tchdr,
70			      sizeof(tchdr));
71}
72
73/**
74 * @name Addition/Modification
75 * @{
76 */
77
78static int class_build(struct rtnl_class *class, int type, int flags,
79		       struct nl_msg **result)
80{
81	struct rtnl_class_ops *cops;
82	int err;
83
84	err = tca_build_msg((struct rtnl_tca *) class, type, flags, result);
85	if (err < 0)
86		return err;
87
88	cops = rtnl_class_lookup_ops(class);
89	if (cops && cops->co_get_opts) {
90		struct nl_msg *opts;
91
92		opts = cops->co_get_opts(class);
93		if (opts) {
94			err = nla_put_nested(*result, TCA_OPTIONS, opts);
95			nlmsg_free(opts);
96			if (err < 0)
97				goto errout;
98		}
99	}
100
101	return 0;
102errout:
103	nlmsg_free(*result);
104	return err;
105}
106
107/**
108 * Build a netlink message to add a new class
109 * @arg class		class to add
110 * @arg flags		additional netlink message flags
111 * @arg result		Pointer to store resulting message.
112 *
113 * Builds a new netlink message requesting an addition of a class.
114 * The netlink message header isn't fully equipped with all relevant
115 * fields and must be sent out via nl_send_auto_complete() or
116 * supplemented as needed.
117 *
118 * Common message flags
119 *   - NLM_F_REPLACE - replace possibly existing classes
120 *
121 * @return 0 on success or a negative error code.
122 */
123int rtnl_class_build_add_request(struct rtnl_class *class, int flags,
124				 struct nl_msg **result)
125{
126	return class_build(class, RTM_NEWTCLASS, NLM_F_CREATE | flags, result);
127}
128
129/**
130 * Add a new class
131 * @arg sk		Netlink socket.
132 * @arg class		class to delete
133 * @arg flags		additional netlink message flags
134 *
135 * Builds a netlink message by calling rtnl_qdisc_build_add_request(),
136 * sends the request to the kernel and waits for the next ACK to be
137 * received and thus blocks until the request has been processed.
138 *
139 * Common message flags
140 *   - NLM_F_REPLACE - replace possibly existing classes
141 *
142 * @return 0 on success or a negative error code
143 */
144int rtnl_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags)
145{
146	struct nl_msg *msg;
147	int err;
148
149	if ((err = rtnl_class_build_add_request(class, flags, &msg)) < 0)
150		return err;
151
152	err = nl_send_auto_complete(sk, msg);
153	nlmsg_free(msg);
154	if (err < 0)
155		return err;
156
157	return wait_for_ack(sk);
158}
159
160/** @} */
161
162/**
163 * @name Cache Management
164 * @{
165 */
166
167/**
168 * Build a class cache including all classes attached to the specified interface
169 * @arg sk		Netlink socket.
170 * @arg ifindex		interface index of the link the classes are
171 *                      attached to.
172 *
173 * Allocates a new cache, initializes it properly and updates it to
174 * include all classes attached to the specified interface.
175 *
176 * @return The cache or NULL if an error has occured.
177 */
178int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex,
179			   struct nl_cache **result)
180{
181	struct nl_cache * cache;
182	int err;
183
184	cache = nl_cache_alloc(&rtnl_class_ops);
185	if (!cache)
186		return -NLE_NOMEM;
187
188	cache->c_iarg1 = ifindex;
189
190	if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
191		nl_cache_free(cache);
192		return err;
193	}
194
195	*result = cache;
196	return 0;
197}
198
199/** @} */
200
201static struct nl_cache_ops rtnl_class_ops = {
202	.co_name		= "route/class",
203	.co_hdrsize		= sizeof(struct tcmsg),
204	.co_msgtypes		= {
205					{ RTM_NEWTCLASS, NL_ACT_NEW, "new" },
206					{ RTM_DELTCLASS, NL_ACT_DEL, "del" },
207					{ RTM_GETTCLASS, NL_ACT_GET, "get" },
208					END_OF_MSGTYPES_LIST,
209				  },
210	.co_protocol		= NETLINK_ROUTE,
211	.co_request_update	= &class_request_update,
212	.co_msg_parser		= &class_msg_parser,
213	.co_obj_ops		= &class_obj_ops,
214};
215
216static void __init class_init(void)
217{
218	nl_cache_mngt_register(&rtnl_class_ops);
219}
220
221static void __exit class_exit(void)
222{
223	nl_cache_mngt_unregister(&rtnl_class_ops);
224}
225
226/** @} */
227