xref: /openbmc/linux/net/sched/cls_matchall.c (revision 8f8d5745bb520c76b81abef4a2cb3023d0313bfd)
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 #include <linux/percpu.h>
16 
17 #include <net/sch_generic.h>
18 #include <net/pkt_cls.h>
19 
20 struct cls_mall_head {
21 	struct tcf_exts exts;
22 	struct tcf_result res;
23 	u32 handle;
24 	u32 flags;
25 	unsigned int in_hw_count;
26 	struct tc_matchall_pcnt __percpu *pf;
27 	struct rcu_work rwork;
28 };
29 
30 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
31 			 struct tcf_result *res)
32 {
33 	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
34 
35 	if (tc_skip_sw(head->flags))
36 		return -1;
37 
38 	*res = head->res;
39 	__this_cpu_inc(head->pf->rhit);
40 	return tcf_exts_exec(skb, &head->exts, res);
41 }
42 
43 static int mall_init(struct tcf_proto *tp)
44 {
45 	return 0;
46 }
47 
48 static void __mall_destroy(struct cls_mall_head *head)
49 {
50 	tcf_exts_destroy(&head->exts);
51 	tcf_exts_put_net(&head->exts);
52 	free_percpu(head->pf);
53 	kfree(head);
54 }
55 
56 static void mall_destroy_work(struct work_struct *work)
57 {
58 	struct cls_mall_head *head = container_of(to_rcu_work(work),
59 						  struct cls_mall_head,
60 						  rwork);
61 	rtnl_lock();
62 	__mall_destroy(head);
63 	rtnl_unlock();
64 }
65 
66 static void mall_destroy_hw_filter(struct tcf_proto *tp,
67 				   struct cls_mall_head *head,
68 				   unsigned long cookie,
69 				   struct netlink_ext_ack *extack)
70 {
71 	struct tc_cls_matchall_offload cls_mall = {};
72 	struct tcf_block *block = tp->chain->block;
73 
74 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
75 	cls_mall.command = TC_CLSMATCHALL_DESTROY;
76 	cls_mall.cookie = cookie;
77 
78 	tc_setup_cb_call(block, TC_SETUP_CLSMATCHALL, &cls_mall, false);
79 	tcf_block_offload_dec(block, &head->flags);
80 }
81 
82 static int mall_replace_hw_filter(struct tcf_proto *tp,
83 				  struct cls_mall_head *head,
84 				  unsigned long cookie,
85 				  struct netlink_ext_ack *extack)
86 {
87 	struct tc_cls_matchall_offload cls_mall = {};
88 	struct tcf_block *block = tp->chain->block;
89 	bool skip_sw = tc_skip_sw(head->flags);
90 	int err;
91 
92 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
93 	cls_mall.command = TC_CLSMATCHALL_REPLACE;
94 	cls_mall.exts = &head->exts;
95 	cls_mall.cookie = cookie;
96 
97 	err = tc_setup_cb_call(block, TC_SETUP_CLSMATCHALL, &cls_mall, skip_sw);
98 	if (err < 0) {
99 		mall_destroy_hw_filter(tp, head, cookie, NULL);
100 		return err;
101 	} else if (err > 0) {
102 		head->in_hw_count = err;
103 		tcf_block_offload_inc(block, &head->flags);
104 	}
105 
106 	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
107 		return -EINVAL;
108 
109 	return 0;
110 }
111 
112 static void mall_destroy(struct tcf_proto *tp, bool rtnl_held,
113 			 struct netlink_ext_ack *extack)
114 {
115 	struct cls_mall_head *head = rtnl_dereference(tp->root);
116 
117 	if (!head)
118 		return;
119 
120 	tcf_unbind_filter(tp, &head->res);
121 
122 	if (!tc_skip_hw(head->flags))
123 		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);
124 
125 	if (tcf_exts_get_net(&head->exts))
126 		tcf_queue_work(&head->rwork, mall_destroy_work);
127 	else
128 		__mall_destroy(head);
129 }
130 
131 static void *mall_get(struct tcf_proto *tp, u32 handle)
132 {
133 	struct cls_mall_head *head = rtnl_dereference(tp->root);
134 
135 	if (head && head->handle == handle)
136 		return head;
137 
138 	return NULL;
139 }
140 
141 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
142 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
143 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
144 };
145 
146 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
147 			  struct cls_mall_head *head,
148 			  unsigned long base, struct nlattr **tb,
149 			  struct nlattr *est, bool ovr,
150 			  struct netlink_ext_ack *extack)
151 {
152 	int err;
153 
154 	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, true,
155 				extack);
156 	if (err < 0)
157 		return err;
158 
159 	if (tb[TCA_MATCHALL_CLASSID]) {
160 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
161 		tcf_bind_filter(tp, &head->res, base);
162 	}
163 	return 0;
164 }
165 
166 static int mall_change(struct net *net, struct sk_buff *in_skb,
167 		       struct tcf_proto *tp, unsigned long base,
168 		       u32 handle, struct nlattr **tca,
169 		       void **arg, bool ovr, bool rtnl_held,
170 		       struct netlink_ext_ack *extack)
171 {
172 	struct cls_mall_head *head = rtnl_dereference(tp->root);
173 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
174 	struct cls_mall_head *new;
175 	u32 flags = 0;
176 	int err;
177 
178 	if (!tca[TCA_OPTIONS])
179 		return -EINVAL;
180 
181 	if (head)
182 		return -EEXIST;
183 
184 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
185 			       mall_policy, NULL);
186 	if (err < 0)
187 		return err;
188 
189 	if (tb[TCA_MATCHALL_FLAGS]) {
190 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
191 		if (!tc_flags_valid(flags))
192 			return -EINVAL;
193 	}
194 
195 	new = kzalloc(sizeof(*new), GFP_KERNEL);
196 	if (!new)
197 		return -ENOBUFS;
198 
199 	err = tcf_exts_init(&new->exts, net, TCA_MATCHALL_ACT, 0);
200 	if (err)
201 		goto err_exts_init;
202 
203 	if (!handle)
204 		handle = 1;
205 	new->handle = handle;
206 	new->flags = flags;
207 	new->pf = alloc_percpu(struct tc_matchall_pcnt);
208 	if (!new->pf) {
209 		err = -ENOMEM;
210 		goto err_alloc_percpu;
211 	}
212 
213 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
214 			     extack);
215 	if (err)
216 		goto err_set_parms;
217 
218 	if (!tc_skip_hw(new->flags)) {
219 		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
220 					     extack);
221 		if (err)
222 			goto err_replace_hw_filter;
223 	}
224 
225 	if (!tc_in_hw(new->flags))
226 		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
227 
228 	*arg = head;
229 	rcu_assign_pointer(tp->root, new);
230 	return 0;
231 
232 err_replace_hw_filter:
233 err_set_parms:
234 	free_percpu(new->pf);
235 err_alloc_percpu:
236 	tcf_exts_destroy(&new->exts);
237 err_exts_init:
238 	kfree(new);
239 	return err;
240 }
241 
242 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
243 		       bool rtnl_held, struct netlink_ext_ack *extack)
244 {
245 	return -EOPNOTSUPP;
246 }
247 
248 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg,
249 		      bool rtnl_held)
250 {
251 	struct cls_mall_head *head = rtnl_dereference(tp->root);
252 
253 	if (arg->count < arg->skip)
254 		goto skip;
255 
256 	if (!head)
257 		return;
258 	if (arg->fn(tp, head, arg) < 0)
259 		arg->stop = 1;
260 skip:
261 	arg->count++;
262 }
263 
264 static int mall_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
265 			  void *cb_priv, struct netlink_ext_ack *extack)
266 {
267 	struct cls_mall_head *head = rtnl_dereference(tp->root);
268 	struct tc_cls_matchall_offload cls_mall = {};
269 	struct tcf_block *block = tp->chain->block;
270 	int err;
271 
272 	if (tc_skip_hw(head->flags))
273 		return 0;
274 
275 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
276 	cls_mall.command = add ?
277 		TC_CLSMATCHALL_REPLACE : TC_CLSMATCHALL_DESTROY;
278 	cls_mall.exts = &head->exts;
279 	cls_mall.cookie = (unsigned long)head;
280 
281 	err = cb(TC_SETUP_CLSMATCHALL, &cls_mall, cb_priv);
282 	if (err) {
283 		if (add && tc_skip_sw(head->flags))
284 			return err;
285 		return 0;
286 	}
287 
288 	tc_cls_offload_cnt_update(block, &head->in_hw_count, &head->flags, add);
289 
290 	return 0;
291 }
292 
293 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
294 		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
295 {
296 	struct tc_matchall_pcnt gpf = {};
297 	struct cls_mall_head *head = fh;
298 	struct nlattr *nest;
299 	int cpu;
300 
301 	if (!head)
302 		return skb->len;
303 
304 	t->tcm_handle = head->handle;
305 
306 	nest = nla_nest_start(skb, TCA_OPTIONS);
307 	if (!nest)
308 		goto nla_put_failure;
309 
310 	if (head->res.classid &&
311 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
312 		goto nla_put_failure;
313 
314 	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
315 		goto nla_put_failure;
316 
317 	for_each_possible_cpu(cpu) {
318 		struct tc_matchall_pcnt *pf = per_cpu_ptr(head->pf, cpu);
319 
320 		gpf.rhit += pf->rhit;
321 	}
322 
323 	if (nla_put_64bit(skb, TCA_MATCHALL_PCNT,
324 			  sizeof(struct tc_matchall_pcnt),
325 			  &gpf, TCA_MATCHALL_PAD))
326 		goto nla_put_failure;
327 
328 	if (tcf_exts_dump(skb, &head->exts))
329 		goto nla_put_failure;
330 
331 	nla_nest_end(skb, nest);
332 
333 	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
334 		goto nla_put_failure;
335 
336 	return skb->len;
337 
338 nla_put_failure:
339 	nla_nest_cancel(skb, nest);
340 	return -1;
341 }
342 
343 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
344 {
345 	struct cls_mall_head *head = fh;
346 
347 	if (head && head->res.classid == classid)
348 		head->res.class = cl;
349 }
350 
351 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
352 	.kind		= "matchall",
353 	.classify	= mall_classify,
354 	.init		= mall_init,
355 	.destroy	= mall_destroy,
356 	.get		= mall_get,
357 	.change		= mall_change,
358 	.delete		= mall_delete,
359 	.walk		= mall_walk,
360 	.reoffload	= mall_reoffload,
361 	.dump		= mall_dump,
362 	.bind_class	= mall_bind_class,
363 	.owner		= THIS_MODULE,
364 };
365 
366 static int __init cls_mall_init(void)
367 {
368 	return register_tcf_proto_ops(&cls_mall_ops);
369 }
370 
371 static void __exit cls_mall_exit(void)
372 {
373 	unregister_tcf_proto_ops(&cls_mall_ops);
374 }
375 
376 module_init(cls_mall_init);
377 module_exit(cls_mall_exit);
378 
379 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
380 MODULE_DESCRIPTION("Match-all classifier");
381 MODULE_LICENSE("GPL v2");
382