xref: /openbmc/linux/net/sched/cls_matchall.c (revision 023e4163)
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 	return NULL;
134 }
135 
136 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
137 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
138 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
139 };
140 
141 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
142 			  struct cls_mall_head *head,
143 			  unsigned long base, struct nlattr **tb,
144 			  struct nlattr *est, bool ovr,
145 			  struct netlink_ext_ack *extack)
146 {
147 	int err;
148 
149 	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, true,
150 				extack);
151 	if (err < 0)
152 		return err;
153 
154 	if (tb[TCA_MATCHALL_CLASSID]) {
155 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
156 		tcf_bind_filter(tp, &head->res, base);
157 	}
158 	return 0;
159 }
160 
161 static int mall_change(struct net *net, struct sk_buff *in_skb,
162 		       struct tcf_proto *tp, unsigned long base,
163 		       u32 handle, struct nlattr **tca,
164 		       void **arg, bool ovr, bool rtnl_held,
165 		       struct netlink_ext_ack *extack)
166 {
167 	struct cls_mall_head *head = rtnl_dereference(tp->root);
168 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
169 	struct cls_mall_head *new;
170 	u32 flags = 0;
171 	int err;
172 
173 	if (!tca[TCA_OPTIONS])
174 		return -EINVAL;
175 
176 	if (head)
177 		return -EEXIST;
178 
179 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
180 			       mall_policy, NULL);
181 	if (err < 0)
182 		return err;
183 
184 	if (tb[TCA_MATCHALL_FLAGS]) {
185 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
186 		if (!tc_flags_valid(flags))
187 			return -EINVAL;
188 	}
189 
190 	new = kzalloc(sizeof(*new), GFP_KERNEL);
191 	if (!new)
192 		return -ENOBUFS;
193 
194 	err = tcf_exts_init(&new->exts, net, TCA_MATCHALL_ACT, 0);
195 	if (err)
196 		goto err_exts_init;
197 
198 	if (!handle)
199 		handle = 1;
200 	new->handle = handle;
201 	new->flags = flags;
202 	new->pf = alloc_percpu(struct tc_matchall_pcnt);
203 	if (!new->pf) {
204 		err = -ENOMEM;
205 		goto err_alloc_percpu;
206 	}
207 
208 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
209 			     extack);
210 	if (err)
211 		goto err_set_parms;
212 
213 	if (!tc_skip_hw(new->flags)) {
214 		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
215 					     extack);
216 		if (err)
217 			goto err_replace_hw_filter;
218 	}
219 
220 	if (!tc_in_hw(new->flags))
221 		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
222 
223 	*arg = head;
224 	rcu_assign_pointer(tp->root, new);
225 	return 0;
226 
227 err_replace_hw_filter:
228 err_set_parms:
229 	free_percpu(new->pf);
230 err_alloc_percpu:
231 	tcf_exts_destroy(&new->exts);
232 err_exts_init:
233 	kfree(new);
234 	return err;
235 }
236 
237 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
238 		       bool rtnl_held, struct netlink_ext_ack *extack)
239 {
240 	return -EOPNOTSUPP;
241 }
242 
243 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg,
244 		      bool rtnl_held)
245 {
246 	struct cls_mall_head *head = rtnl_dereference(tp->root);
247 
248 	if (arg->count < arg->skip)
249 		goto skip;
250 
251 	if (!head)
252 		return;
253 	if (arg->fn(tp, head, arg) < 0)
254 		arg->stop = 1;
255 skip:
256 	arg->count++;
257 }
258 
259 static int mall_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
260 			  void *cb_priv, struct netlink_ext_ack *extack)
261 {
262 	struct cls_mall_head *head = rtnl_dereference(tp->root);
263 	struct tc_cls_matchall_offload cls_mall = {};
264 	struct tcf_block *block = tp->chain->block;
265 	int err;
266 
267 	if (tc_skip_hw(head->flags))
268 		return 0;
269 
270 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
271 	cls_mall.command = add ?
272 		TC_CLSMATCHALL_REPLACE : TC_CLSMATCHALL_DESTROY;
273 	cls_mall.exts = &head->exts;
274 	cls_mall.cookie = (unsigned long)head;
275 
276 	err = cb(TC_SETUP_CLSMATCHALL, &cls_mall, cb_priv);
277 	if (err) {
278 		if (add && tc_skip_sw(head->flags))
279 			return err;
280 		return 0;
281 	}
282 
283 	tc_cls_offload_cnt_update(block, &head->in_hw_count, &head->flags, add);
284 
285 	return 0;
286 }
287 
288 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
289 		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
290 {
291 	struct tc_matchall_pcnt gpf = {};
292 	struct cls_mall_head *head = fh;
293 	struct nlattr *nest;
294 	int cpu;
295 
296 	if (!head)
297 		return skb->len;
298 
299 	t->tcm_handle = head->handle;
300 
301 	nest = nla_nest_start(skb, TCA_OPTIONS);
302 	if (!nest)
303 		goto nla_put_failure;
304 
305 	if (head->res.classid &&
306 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
307 		goto nla_put_failure;
308 
309 	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
310 		goto nla_put_failure;
311 
312 	for_each_possible_cpu(cpu) {
313 		struct tc_matchall_pcnt *pf = per_cpu_ptr(head->pf, cpu);
314 
315 		gpf.rhit += pf->rhit;
316 	}
317 
318 	if (nla_put_64bit(skb, TCA_MATCHALL_PCNT,
319 			  sizeof(struct tc_matchall_pcnt),
320 			  &gpf, TCA_MATCHALL_PAD))
321 		goto nla_put_failure;
322 
323 	if (tcf_exts_dump(skb, &head->exts))
324 		goto nla_put_failure;
325 
326 	nla_nest_end(skb, nest);
327 
328 	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
329 		goto nla_put_failure;
330 
331 	return skb->len;
332 
333 nla_put_failure:
334 	nla_nest_cancel(skb, nest);
335 	return -1;
336 }
337 
338 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
339 {
340 	struct cls_mall_head *head = fh;
341 
342 	if (head && head->res.classid == classid)
343 		head->res.class = cl;
344 }
345 
346 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
347 	.kind		= "matchall",
348 	.classify	= mall_classify,
349 	.init		= mall_init,
350 	.destroy	= mall_destroy,
351 	.get		= mall_get,
352 	.change		= mall_change,
353 	.delete		= mall_delete,
354 	.walk		= mall_walk,
355 	.reoffload	= mall_reoffload,
356 	.dump		= mall_dump,
357 	.bind_class	= mall_bind_class,
358 	.owner		= THIS_MODULE,
359 };
360 
361 static int __init cls_mall_init(void)
362 {
363 	return register_tcf_proto_ops(&cls_mall_ops);
364 }
365 
366 static void __exit cls_mall_exit(void)
367 {
368 	unregister_tcf_proto_ops(&cls_mall_ops);
369 }
370 
371 module_init(cls_mall_init);
372 module_exit(cls_mall_exit);
373 
374 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
375 MODULE_DESCRIPTION("Match-all classifier");
376 MODULE_LICENSE("GPL v2");
377