1 /*
2 * lib/route/classifier.c Classifier
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) 2003-2009 Thomas Graf <tgraf@suug.ch>
10 */
11
12 /**
13 * @ingroup tc
14 * @defgroup cls Classifiers
15 *
16 * @par Classifier Identification
17 * - protocol
18 * - priority
19 * - parent
20 * - interface
21 * - kind
22 * - handle
23 *
24 * @{
25 */
26
27 #include <netlink-local.h>
28 #include <netlink-tc.h>
29 #include <netlink/netlink.h>
30 #include <netlink/utils.h>
31 #include <netlink/route/tc.h>
32 #include <netlink/route/classifier.h>
33 #include <netlink/route/classifier-modules.h>
34 #include <netlink/route/link.h>
35
36 static struct nl_cache_ops rtnl_cls_ops;
37
cls_msg_parser(struct nl_cache_ops * ops,struct sockaddr_nl * who,struct nlmsghdr * nlh,struct nl_parser_param * pp)38 static int cls_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
39 struct nlmsghdr *nlh, struct nl_parser_param *pp)
40 {
41 struct rtnl_cls_ops *cops;
42 struct rtnl_cls *cls;
43 int err;
44
45 cls = rtnl_cls_alloc();
46 if (!cls) {
47 err = -NLE_NOMEM;
48 goto errout;
49 }
50 cls->ce_msgtype = nlh->nlmsg_type;
51
52 err = tca_msg_parser(nlh, (struct rtnl_tca *) cls);
53 if (err < 0)
54 goto errout_free;
55
56 cls->c_prio = TC_H_MAJ(cls->c_info) >> 16;
57 cls->c_protocol = ntohs(TC_H_MIN(cls->c_info));
58
59 cops = rtnl_cls_lookup_ops(cls);
60 if (cops && cops->co_msg_parser && (err = cops->co_msg_parser(cls)) < 0)
61 goto errout_free;
62
63 err = pp->pp_cb((struct nl_object *) cls, pp);
64 errout_free:
65 rtnl_cls_put(cls);
66 errout:
67 return err;
68 }
69
cls_request_update(struct nl_cache * cache,struct nl_sock * sk)70 static int cls_request_update(struct nl_cache *cache, struct nl_sock *sk)
71 {
72 struct tcmsg tchdr = {
73 .tcm_family = AF_UNSPEC,
74 .tcm_ifindex = cache->c_iarg1,
75 .tcm_parent = cache->c_iarg2,
76 };
77
78 return nl_send_simple(sk, RTM_GETTFILTER, NLM_F_DUMP, &tchdr,
79 sizeof(tchdr));
80 }
81
82
cls_build(struct rtnl_cls * cls,int type,int flags,struct nl_msg ** result)83 static int cls_build(struct rtnl_cls *cls, int type, int flags,
84 struct nl_msg **result)
85 {
86 struct rtnl_cls_ops *cops;
87 int err, prio, proto;
88 struct tcmsg *tchdr;
89
90 err = tca_build_msg((struct rtnl_tca *) cls, type, flags, result);
91 if (err < 0)
92 return err;
93
94 tchdr = nlmsg_data(nlmsg_hdr(*result));
95 prio = rtnl_cls_get_prio(cls);
96 proto = rtnl_cls_get_protocol(cls);
97 tchdr->tcm_info = TC_H_MAKE(prio << 16, htons(proto));
98
99 cops = rtnl_cls_lookup_ops(cls);
100 if (cops && cops->co_get_opts) {
101 struct nl_msg *opts;
102
103 if (!(opts = nlmsg_alloc())) {
104 err = -NLE_NOMEM;
105 goto errout;
106 }
107
108 if (!(err = cops->co_get_opts(cls, opts)))
109 err = nla_put_nested(*result, TCA_OPTIONS, opts);
110
111 nlmsg_free(opts);
112 if (err < 0)
113 goto errout;
114 }
115
116 return 0;
117 errout:
118 nlmsg_free(*result);
119 return err;
120 }
121
122 /**
123 * @name Classifier Addition/Modification/Deletion
124 * @{
125 */
126
127 /**
128 * Build a netlink message to add a new classifier
129 * @arg cls classifier to add
130 * @arg flags additional netlink message flags
131 * @arg result Pointer to store resulting message.
132 *
133 * Builds a new netlink message requesting an addition of a classifier
134 * The netlink message header isn't fully equipped with all relevant
135 * fields and must be sent out via nl_send_auto_complete() or
136 * supplemented as needed. \a classifier must contain the attributes of
137 * the new classifier set via \c rtnl_cls_set_* functions. \a opts
138 * may point to the clsasifier specific options.
139 *
140 * @return 0 on success or a negative error code.
141 */
rtnl_cls_build_add_request(struct rtnl_cls * cls,int flags,struct nl_msg ** result)142 int rtnl_cls_build_add_request(struct rtnl_cls *cls, int flags,
143 struct nl_msg **result)
144 {
145 return cls_build(cls, RTM_NEWTFILTER, NLM_F_CREATE | flags, result);
146 }
147
148 /**
149 * Add a new classifier
150 * @arg sk Netlink socket.
151 * @arg cls classifier to add
152 * @arg flags additional netlink message flags
153 *
154 * Builds a netlink message by calling rtnl_cls_build_add_request(),
155 * sends the request to the kernel and waits for the next ACK to be
156 * received and thus blocks until the request has been processed.
157 *
158 * @return 0 on sucess or a negative error if an error occured.
159 */
rtnl_cls_add(struct nl_sock * sk,struct rtnl_cls * cls,int flags)160 int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
161 {
162 struct nl_msg *msg;
163 int err;
164
165 if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0)
166 return err;
167
168 err = nl_send_auto_complete(sk, msg);
169 nlmsg_free(msg);
170 if (err < 0)
171 return err;
172
173 return nl_wait_for_ack(sk);
174 }
175
176 /**
177 * Build a netlink message to change classifier attributes
178 * @arg cls classifier to change
179 * @arg flags additional netlink message flags
180 * @arg result Pointer to store resulting message.
181 *
182 * Builds a new netlink message requesting a change of a neigh
183 * attributes. The netlink message header isn't fully equipped with
184 * all relevant fields and must thus be sent out via nl_send_auto_complete()
185 * or supplemented as needed.
186 *
187 * @return 0 on success or a negative error code.
188 */
rtnl_cls_build_change_request(struct rtnl_cls * cls,int flags,struct nl_msg ** result)189 int rtnl_cls_build_change_request(struct rtnl_cls *cls, int flags,
190 struct nl_msg **result)
191 {
192 return cls_build(cls, RTM_NEWTFILTER, NLM_F_REPLACE | flags, result);
193 }
194
195 /**
196 * Change a classifier
197 * @arg sk Netlink socket.
198 * @arg cls classifier to change
199 * @arg flags additional netlink message flags
200 *
201 * Builds a netlink message by calling rtnl_cls_build_change_request(),
202 * sends the request to the kernel and waits for the next ACK to be
203 * received and thus blocks until the request has been processed.
204 *
205 * @return 0 on sucess or a negative error if an error occured.
206 */
rtnl_cls_change(struct nl_sock * sk,struct rtnl_cls * cls,int flags)207 int rtnl_cls_change(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
208 {
209 struct nl_msg *msg;
210 int err;
211
212 if ((err = rtnl_cls_build_change_request(cls, flags, &msg)) < 0)
213 return err;
214
215 err = nl_send_auto_complete(sk, msg);
216 nlmsg_free(msg);
217 if (err < 0)
218 return err;
219
220 return nl_wait_for_ack(sk);
221 }
222
223 /**
224 * Build a netlink request message to delete a classifier
225 * @arg cls classifier to delete
226 * @arg flags additional netlink message flags
227 * @arg result Pointer to store resulting message.
228 *
229 * Builds a new netlink message requesting a deletion of a classifier.
230 * The netlink message header isn't fully equipped with all relevant
231 * fields and must thus be sent out via nl_send_auto_complete()
232 * or supplemented as needed.
233 *
234 * @return 0 on success or a negative error code.
235 */
rtnl_cls_build_delete_request(struct rtnl_cls * cls,int flags,struct nl_msg ** result)236 int rtnl_cls_build_delete_request(struct rtnl_cls *cls, int flags,
237 struct nl_msg **result)
238 {
239 return cls_build(cls, RTM_DELTFILTER, flags, result);
240 }
241
242
243 /**
244 * Delete a classifier
245 * @arg sk Netlink socket.
246 * @arg cls classifier to delete
247 * @arg flags additional netlink message flags
248 *
249 * Builds a netlink message by calling rtnl_cls_build_delete_request(),
250 * sends the request to the kernel and waits for the next ACK to be
251 * received and thus blocks until the request has been processed.
252 *
253 * @return 0 on sucess or a negative error if an error occured.
254 */
rtnl_cls_delete(struct nl_sock * sk,struct rtnl_cls * cls,int flags)255 int rtnl_cls_delete(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
256 {
257 struct nl_msg *msg;
258 int err;
259
260 if ((err = rtnl_cls_build_delete_request(cls, flags, &msg)) < 0)
261 return err;
262
263 err = nl_send_auto_complete(sk, msg);
264 nlmsg_free(msg);
265 if (err < 0)
266 return err;
267
268 return nl_wait_for_ack(sk);
269 }
270
271 /** @} */
272
273 /**
274 * @name Cache Management
275 * @{
276 */
277
278 /**
279 * Build a classifier cache including all classifiers attached to the
280 * specified class/qdisc on eht specified interface.
281 * @arg sk Netlink socket.
282 * @arg ifindex interface index of the link the classes are
283 * attached to.
284 * @arg parent parent qdisc/class
285 * @arg result Pointer to store resulting cache.
286 *
287 * Allocates a new cache, initializes it properly and updates it to
288 * include all classes attached to the specified interface.
289 *
290 * @note The caller is responsible for destroying and freeing the
291 * cache after using it.
292 * @return 0 on success or a negative error code.
293 */
rtnl_cls_alloc_cache(struct nl_sock * sk,int ifindex,uint32_t parent,struct nl_cache ** result)294 int rtnl_cls_alloc_cache(struct nl_sock *sk, int ifindex, uint32_t parent, struct nl_cache **result)
295 {
296 struct nl_cache * cache;
297 int err;
298
299 if (!(cache = nl_cache_alloc(&rtnl_cls_ops)))
300 return -NLE_NOMEM;
301
302 cache->c_iarg1 = ifindex;
303 cache->c_iarg2 = parent;
304
305 if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
306 nl_cache_free(cache);
307 return err;
308 }
309
310 *result = cache;
311 return 0;
312 }
313
314 /** @} */
315
316 static struct nl_cache_ops rtnl_cls_ops = {
317 .co_name = "route/cls",
318 .co_hdrsize = sizeof(struct tcmsg),
319 .co_msgtypes = {
320 { RTM_NEWTFILTER, NL_ACT_NEW, "new" },
321 { RTM_DELTFILTER, NL_ACT_DEL, "del" },
322 { RTM_GETTFILTER, NL_ACT_GET, "get" },
323 END_OF_MSGTYPES_LIST,
324 },
325 .co_protocol = NETLINK_ROUTE,
326 .co_request_update = cls_request_update,
327 .co_msg_parser = cls_msg_parser,
328 .co_obj_ops = &cls_obj_ops,
329 };
330
cls_init(void)331 static void __init cls_init(void)
332 {
333 nl_cache_mngt_register(&rtnl_cls_ops);
334 }
335
cls_exit(void)336 static void __exit cls_exit(void)
337 {
338 nl_cache_mngt_unregister(&rtnl_cls_ops);
339 }
340
341 /** @} */
342