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
28 static struct nl_cache_ops rtnl_class_ops;
29
class_msg_parser(struct nl_cache_ops * ops,struct sockaddr_nl * who,struct nlmsghdr * n,struct nl_parser_param * pp)30 static 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);
56 errout_free:
57 rtnl_class_put(class);
58 errout:
59 return err;
60 }
61
class_request_update(struct nl_cache * cache,struct nl_sock * sk)62 static 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
class_build(struct rtnl_class * class,int type,int flags,struct nl_msg ** result)78 static 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;
102 errout:
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 */
rtnl_class_build_add_request(struct rtnl_class * class,int flags,struct nl_msg ** result)123 int 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 */
rtnl_class_add(struct nl_sock * sk,struct rtnl_class * class,int flags)144 int 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
rtnl_class_build_delete_request(struct rtnl_class * class,struct nl_msg ** result)160 int rtnl_class_build_delete_request(struct rtnl_class *class,
161 struct nl_msg **result)
162 {
163 struct nl_msg *msg;
164 struct tcmsg tchdr;
165 int required = TCA_ATTR_IFINDEX | TCA_ATTR_PARENT;
166
167 if ((class->ce_mask & required) != required)
168 BUG();
169
170 msg = nlmsg_alloc_simple(RTM_DELTCLASS, 0);
171 if (!msg)
172 return -NLE_NOMEM;
173
174 tchdr.tcm_family = AF_UNSPEC;
175 tchdr.tcm_handle = class->c_handle;
176 tchdr.tcm_parent = class->c_parent;
177 tchdr.tcm_ifindex = class->c_ifindex;
178 if (nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO) < 0) {
179 nlmsg_free(msg);
180 return -NLE_MSGSIZE;
181 }
182
183 *result = msg;
184 return 0;
185 }
186
187 /**
188 * Delete a class
189 * @arg sk Netlink socket.
190 * @arg class class to delete
191 *
192 * Builds a netlink message by calling rtnl_class_build_delete_request(),
193 * sends the request to the kernel and waits for the ACK to be
194 * received and thus blocks until the request has been processed.
195 *
196 * @return 0 on success or a negative error code
197 */
rtnl_class_delete(struct nl_sock * sk,struct rtnl_class * class)198 int rtnl_class_delete(struct nl_sock *sk, struct rtnl_class *class)
199 {
200 struct nl_msg *msg;
201 int err;
202
203 if ((err = rtnl_class_build_delete_request(class, &msg)) < 0)
204 return err;
205
206 err = nl_send_auto_complete(sk, msg);
207 nlmsg_free(msg);
208 if (err < 0)
209 return err;
210
211 return wait_for_ack(sk);
212 }
213
214 /** @} */
215
216 /**
217 * @name Cache Management
218 * @{
219 */
220
221 /**
222 * Build a class cache including all classes attached to the specified interface
223 * @arg sk Netlink socket.
224 * @arg ifindex interface index of the link the classes are
225 * attached to.
226 *
227 * Allocates a new cache, initializes it properly and updates it to
228 * include all classes attached to the specified interface.
229 *
230 * @return The cache or NULL if an error has occured.
231 */
rtnl_class_alloc_cache(struct nl_sock * sk,int ifindex,struct nl_cache ** result)232 int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex,
233 struct nl_cache **result)
234 {
235 struct nl_cache * cache;
236 int err;
237
238 cache = nl_cache_alloc(&rtnl_class_ops);
239 if (!cache)
240 return -NLE_NOMEM;
241
242 cache->c_iarg1 = ifindex;
243
244 if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
245 nl_cache_free(cache);
246 return err;
247 }
248
249 *result = cache;
250 return 0;
251 }
252
253 /**
254 * Look up class by its handle in the provided cache
255 * @arg cache class cache
256 * @arg ifindex interface the class is attached to
257 * @arg handle class handle
258 * @return pointer to class inside the cache or NULL if no match was found.
259 */
rtnl_class_get(struct nl_cache * cache,int ifindex,uint32_t handle)260 struct rtnl_class *rtnl_class_get(struct nl_cache *cache, int ifindex,
261 uint32_t handle)
262 {
263 struct rtnl_class *class;
264
265 if (cache->c_ops != &rtnl_class_ops)
266 return NULL;
267
268 nl_list_for_each_entry(class, &cache->c_items, ce_list) {
269 if (class->c_handle == handle && class->c_ifindex == ifindex) {
270 nl_object_get((struct nl_object *) class);
271 return class;
272 }
273 }
274 return NULL;
275 }
276
277 /** @} */
278
279 static struct nl_cache_ops rtnl_class_ops = {
280 .co_name = "route/class",
281 .co_hdrsize = sizeof(struct tcmsg),
282 .co_msgtypes = {
283 { RTM_NEWTCLASS, NL_ACT_NEW, "new" },
284 { RTM_DELTCLASS, NL_ACT_DEL, "del" },
285 { RTM_GETTCLASS, NL_ACT_GET, "get" },
286 END_OF_MSGTYPES_LIST,
287 },
288 .co_protocol = NETLINK_ROUTE,
289 .co_request_update = &class_request_update,
290 .co_msg_parser = &class_msg_parser,
291 .co_obj_ops = &class_obj_ops,
292 };
293
class_init(void)294 static void __init class_init(void)
295 {
296 nl_cache_mngt_register(&rtnl_class_ops);
297 }
298
class_exit(void)299 static void __exit class_exit(void)
300 {
301 nl_cache_mngt_unregister(&rtnl_class_ops);
302 }
303
304 /** @} */
305