xref: /linux/net/sched/cls_matchall.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * net/sched/cls_matchll.c		Match-all classifier
3  *
4  * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 
16 #include <net/sch_generic.h>
17 #include <net/pkt_cls.h>
18 
19 struct cls_mall_filter {
20 	struct tcf_exts exts;
21 	struct tcf_result res;
22 	u32 handle;
23 	struct rcu_head	rcu;
24 	u32 flags;
25 };
26 
27 struct cls_mall_head {
28 	struct cls_mall_filter *filter;
29 	struct rcu_head	rcu;
30 };
31 
32 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
33 			 struct tcf_result *res)
34 {
35 	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
36 	struct cls_mall_filter *f = head->filter;
37 
38 	if (tc_skip_sw(f->flags))
39 		return -1;
40 
41 	return tcf_exts_exec(skb, &f->exts, res);
42 }
43 
44 static int mall_init(struct tcf_proto *tp)
45 {
46 	struct cls_mall_head *head;
47 
48 	head = kzalloc(sizeof(*head), GFP_KERNEL);
49 	if (!head)
50 		return -ENOBUFS;
51 
52 	rcu_assign_pointer(tp->root, head);
53 
54 	return 0;
55 }
56 
57 static void mall_destroy_filter(struct rcu_head *head)
58 {
59 	struct cls_mall_filter *f = container_of(head, struct cls_mall_filter, rcu);
60 
61 	tcf_exts_destroy(&f->exts);
62 
63 	kfree(f);
64 }
65 
66 static int mall_replace_hw_filter(struct tcf_proto *tp,
67 				  struct cls_mall_filter *f,
68 				  unsigned long cookie)
69 {
70 	struct net_device *dev = tp->q->dev_queue->dev;
71 	struct tc_to_netdev offload;
72 	struct tc_cls_matchall_offload mall_offload = {0};
73 
74 	offload.type = TC_SETUP_MATCHALL;
75 	offload.cls_mall = &mall_offload;
76 	offload.cls_mall->command = TC_CLSMATCHALL_REPLACE;
77 	offload.cls_mall->exts = &f->exts;
78 	offload.cls_mall->cookie = cookie;
79 
80 	return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
81 					     &offload);
82 }
83 
84 static void mall_destroy_hw_filter(struct tcf_proto *tp,
85 				   struct cls_mall_filter *f,
86 				   unsigned long cookie)
87 {
88 	struct net_device *dev = tp->q->dev_queue->dev;
89 	struct tc_to_netdev offload;
90 	struct tc_cls_matchall_offload mall_offload = {0};
91 
92 	offload.type = TC_SETUP_MATCHALL;
93 	offload.cls_mall = &mall_offload;
94 	offload.cls_mall->command = TC_CLSMATCHALL_DESTROY;
95 	offload.cls_mall->exts = NULL;
96 	offload.cls_mall->cookie = cookie;
97 
98 	dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
99 					     &offload);
100 }
101 
102 static bool mall_destroy(struct tcf_proto *tp, bool force)
103 {
104 	struct cls_mall_head *head = rtnl_dereference(tp->root);
105 	struct net_device *dev = tp->q->dev_queue->dev;
106 	struct cls_mall_filter *f = head->filter;
107 
108 	if (!force && f)
109 		return false;
110 
111 	if (f) {
112 		if (tc_should_offload(dev, tp, f->flags))
113 			mall_destroy_hw_filter(tp, f, (unsigned long) f);
114 
115 		call_rcu(&f->rcu, mall_destroy_filter);
116 	}
117 	RCU_INIT_POINTER(tp->root, NULL);
118 	kfree_rcu(head, rcu);
119 	return true;
120 }
121 
122 static unsigned long mall_get(struct tcf_proto *tp, u32 handle)
123 {
124 	struct cls_mall_head *head = rtnl_dereference(tp->root);
125 	struct cls_mall_filter *f = head->filter;
126 
127 	if (f && f->handle == handle)
128 		return (unsigned long) f;
129 	return 0;
130 }
131 
132 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
133 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
134 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
135 };
136 
137 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
138 			  struct cls_mall_filter *f,
139 			  unsigned long base, struct nlattr **tb,
140 			  struct nlattr *est, bool ovr)
141 {
142 	struct tcf_exts e;
143 	int err;
144 
145 	tcf_exts_init(&e, TCA_MATCHALL_ACT, 0);
146 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
147 	if (err < 0)
148 		return err;
149 
150 	if (tb[TCA_MATCHALL_CLASSID]) {
151 		f->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
152 		tcf_bind_filter(tp, &f->res, base);
153 	}
154 
155 	tcf_exts_change(tp, &f->exts, &e);
156 
157 	return 0;
158 }
159 
160 static int mall_change(struct net *net, struct sk_buff *in_skb,
161 		       struct tcf_proto *tp, unsigned long base,
162 		       u32 handle, struct nlattr **tca,
163 		       unsigned long *arg, bool ovr)
164 {
165 	struct cls_mall_head *head = rtnl_dereference(tp->root);
166 	struct cls_mall_filter *fold = (struct cls_mall_filter *) *arg;
167 	struct net_device *dev = tp->q->dev_queue->dev;
168 	struct cls_mall_filter *f;
169 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
170 	u32 flags = 0;
171 	int err;
172 
173 	if (!tca[TCA_OPTIONS])
174 		return -EINVAL;
175 
176 	if (head->filter)
177 		return -EBUSY;
178 
179 	if (fold)
180 		return -EINVAL;
181 
182 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX,
183 			       tca[TCA_OPTIONS], mall_policy);
184 	if (err < 0)
185 		return err;
186 
187 	if (tb[TCA_MATCHALL_FLAGS]) {
188 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
189 		if (!tc_flags_valid(flags))
190 			return -EINVAL;
191 	}
192 
193 	f = kzalloc(sizeof(*f), GFP_KERNEL);
194 	if (!f)
195 		return -ENOBUFS;
196 
197 	tcf_exts_init(&f->exts, TCA_MATCHALL_ACT, 0);
198 
199 	if (!handle)
200 		handle = 1;
201 	f->handle = handle;
202 	f->flags = flags;
203 
204 	err = mall_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr);
205 	if (err)
206 		goto errout;
207 
208 	if (tc_should_offload(dev, tp, flags)) {
209 		err = mall_replace_hw_filter(tp, f, (unsigned long) f);
210 		if (err) {
211 			if (tc_skip_sw(flags))
212 				goto errout;
213 			else
214 				err = 0;
215 		}
216 	}
217 
218 	*arg = (unsigned long) f;
219 	rcu_assign_pointer(head->filter, f);
220 
221 	return 0;
222 
223 errout:
224 	kfree(f);
225 	return err;
226 }
227 
228 static int mall_delete(struct tcf_proto *tp, unsigned long arg)
229 {
230 	struct cls_mall_head *head = rtnl_dereference(tp->root);
231 	struct cls_mall_filter *f = (struct cls_mall_filter *) arg;
232 	struct net_device *dev = tp->q->dev_queue->dev;
233 
234 	if (tc_should_offload(dev, tp, f->flags))
235 		mall_destroy_hw_filter(tp, f, (unsigned long) f);
236 
237 	RCU_INIT_POINTER(head->filter, NULL);
238 	tcf_unbind_filter(tp, &f->res);
239 	call_rcu(&f->rcu, mall_destroy_filter);
240 	return 0;
241 }
242 
243 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
244 {
245 	struct cls_mall_head *head = rtnl_dereference(tp->root);
246 	struct cls_mall_filter *f = head->filter;
247 
248 	if (arg->count < arg->skip)
249 		goto skip;
250 	if (arg->fn(tp, (unsigned long) f, arg) < 0)
251 		arg->stop = 1;
252 skip:
253 	arg->count++;
254 }
255 
256 static int mall_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
257 		     struct sk_buff *skb, struct tcmsg *t)
258 {
259 	struct cls_mall_filter *f = (struct cls_mall_filter *) fh;
260 	struct nlattr *nest;
261 
262 	if (!f)
263 		return skb->len;
264 
265 	t->tcm_handle = f->handle;
266 
267 	nest = nla_nest_start(skb, TCA_OPTIONS);
268 	if (!nest)
269 		goto nla_put_failure;
270 
271 	if (f->res.classid &&
272 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, f->res.classid))
273 		goto nla_put_failure;
274 
275 	if (tcf_exts_dump(skb, &f->exts))
276 		goto nla_put_failure;
277 
278 	nla_nest_end(skb, nest);
279 
280 	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
281 		goto nla_put_failure;
282 
283 	return skb->len;
284 
285 nla_put_failure:
286 	nla_nest_cancel(skb, nest);
287 	return -1;
288 }
289 
290 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
291 	.kind		= "matchall",
292 	.classify	= mall_classify,
293 	.init		= mall_init,
294 	.destroy	= mall_destroy,
295 	.get		= mall_get,
296 	.change		= mall_change,
297 	.delete		= mall_delete,
298 	.walk		= mall_walk,
299 	.dump		= mall_dump,
300 	.owner		= THIS_MODULE,
301 };
302 
303 static int __init cls_mall_init(void)
304 {
305 	return register_tcf_proto_ops(&cls_mall_ops);
306 }
307 
308 static void __exit cls_mall_exit(void)
309 {
310 	unregister_tcf_proto_ops(&cls_mall_ops);
311 }
312 
313 module_init(cls_mall_init);
314 module_exit(cls_mall_exit);
315 
316 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
317 MODULE_DESCRIPTION("Match-all classifier");
318 MODULE_LICENSE("GPL v2");
319