xref: /openbmc/linux/net/sched/cls_matchall.c (revision a17922de)
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_head {
20 	struct tcf_exts exts;
21 	struct tcf_result res;
22 	u32 handle;
23 	u32 flags;
24 	unsigned int in_hw_count;
25 	struct rcu_work rwork;
26 };
27 
28 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
29 			 struct tcf_result *res)
30 {
31 	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
32 
33 	if (tc_skip_sw(head->flags))
34 		return -1;
35 
36 	*res = head->res;
37 	return tcf_exts_exec(skb, &head->exts, res);
38 }
39 
40 static int mall_init(struct tcf_proto *tp)
41 {
42 	return 0;
43 }
44 
45 static void __mall_destroy(struct cls_mall_head *head)
46 {
47 	tcf_exts_destroy(&head->exts);
48 	tcf_exts_put_net(&head->exts);
49 	kfree(head);
50 }
51 
52 static void mall_destroy_work(struct work_struct *work)
53 {
54 	struct cls_mall_head *head = container_of(to_rcu_work(work),
55 						  struct cls_mall_head,
56 						  rwork);
57 	rtnl_lock();
58 	__mall_destroy(head);
59 	rtnl_unlock();
60 }
61 
62 static void mall_destroy_hw_filter(struct tcf_proto *tp,
63 				   struct cls_mall_head *head,
64 				   unsigned long cookie,
65 				   struct netlink_ext_ack *extack)
66 {
67 	struct tc_cls_matchall_offload cls_mall = {};
68 	struct tcf_block *block = tp->chain->block;
69 
70 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
71 	cls_mall.command = TC_CLSMATCHALL_DESTROY;
72 	cls_mall.cookie = cookie;
73 
74 	tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
75 	tcf_block_offload_dec(block, &head->flags);
76 }
77 
78 static int mall_replace_hw_filter(struct tcf_proto *tp,
79 				  struct cls_mall_head *head,
80 				  unsigned long cookie,
81 				  struct netlink_ext_ack *extack)
82 {
83 	struct tc_cls_matchall_offload cls_mall = {};
84 	struct tcf_block *block = tp->chain->block;
85 	bool skip_sw = tc_skip_sw(head->flags);
86 	int err;
87 
88 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
89 	cls_mall.command = TC_CLSMATCHALL_REPLACE;
90 	cls_mall.exts = &head->exts;
91 	cls_mall.cookie = cookie;
92 
93 	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
94 			       &cls_mall, skip_sw);
95 	if (err < 0) {
96 		mall_destroy_hw_filter(tp, head, cookie, NULL);
97 		return err;
98 	} else if (err > 0) {
99 		head->in_hw_count = err;
100 		tcf_block_offload_inc(block, &head->flags);
101 	}
102 
103 	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
104 		return -EINVAL;
105 
106 	return 0;
107 }
108 
109 static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
110 {
111 	struct cls_mall_head *head = rtnl_dereference(tp->root);
112 
113 	if (!head)
114 		return;
115 
116 	if (!tc_skip_hw(head->flags))
117 		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);
118 
119 	if (tcf_exts_get_net(&head->exts))
120 		tcf_queue_work(&head->rwork, mall_destroy_work);
121 	else
122 		__mall_destroy(head);
123 }
124 
125 static void *mall_get(struct tcf_proto *tp, u32 handle)
126 {
127 	return NULL;
128 }
129 
130 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
131 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
132 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
133 };
134 
135 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
136 			  struct cls_mall_head *head,
137 			  unsigned long base, struct nlattr **tb,
138 			  struct nlattr *est, bool ovr,
139 			  struct netlink_ext_ack *extack)
140 {
141 	int err;
142 
143 	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
144 	if (err < 0)
145 		return err;
146 
147 	if (tb[TCA_MATCHALL_CLASSID]) {
148 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
149 		tcf_bind_filter(tp, &head->res, base);
150 	}
151 	return 0;
152 }
153 
154 static int mall_change(struct net *net, struct sk_buff *in_skb,
155 		       struct tcf_proto *tp, unsigned long base,
156 		       u32 handle, struct nlattr **tca,
157 		       void **arg, bool ovr, struct netlink_ext_ack *extack)
158 {
159 	struct cls_mall_head *head = rtnl_dereference(tp->root);
160 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
161 	struct cls_mall_head *new;
162 	u32 flags = 0;
163 	int err;
164 
165 	if (!tca[TCA_OPTIONS])
166 		return -EINVAL;
167 
168 	if (head)
169 		return -EEXIST;
170 
171 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
172 			       mall_policy, NULL);
173 	if (err < 0)
174 		return err;
175 
176 	if (tb[TCA_MATCHALL_FLAGS]) {
177 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
178 		if (!tc_flags_valid(flags))
179 			return -EINVAL;
180 	}
181 
182 	new = kzalloc(sizeof(*new), GFP_KERNEL);
183 	if (!new)
184 		return -ENOBUFS;
185 
186 	err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
187 	if (err)
188 		goto err_exts_init;
189 
190 	if (!handle)
191 		handle = 1;
192 	new->handle = handle;
193 	new->flags = flags;
194 
195 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
196 			     extack);
197 	if (err)
198 		goto err_set_parms;
199 
200 	if (!tc_skip_hw(new->flags)) {
201 		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
202 					     extack);
203 		if (err)
204 			goto err_replace_hw_filter;
205 	}
206 
207 	if (!tc_in_hw(new->flags))
208 		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
209 
210 	*arg = head;
211 	rcu_assign_pointer(tp->root, new);
212 	return 0;
213 
214 err_replace_hw_filter:
215 err_set_parms:
216 	tcf_exts_destroy(&new->exts);
217 err_exts_init:
218 	kfree(new);
219 	return err;
220 }
221 
222 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
223 		       struct netlink_ext_ack *extack)
224 {
225 	return -EOPNOTSUPP;
226 }
227 
228 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
229 {
230 	struct cls_mall_head *head = rtnl_dereference(tp->root);
231 
232 	if (arg->count < arg->skip)
233 		goto skip;
234 	if (arg->fn(tp, head, arg) < 0)
235 		arg->stop = 1;
236 skip:
237 	arg->count++;
238 }
239 
240 static int mall_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
241 			  void *cb_priv, struct netlink_ext_ack *extack)
242 {
243 	struct cls_mall_head *head = rtnl_dereference(tp->root);
244 	struct tc_cls_matchall_offload cls_mall = {};
245 	struct tcf_block *block = tp->chain->block;
246 	int err;
247 
248 	if (tc_skip_hw(head->flags))
249 		return 0;
250 
251 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
252 	cls_mall.command = add ?
253 		TC_CLSMATCHALL_REPLACE : TC_CLSMATCHALL_DESTROY;
254 	cls_mall.exts = &head->exts;
255 	cls_mall.cookie = (unsigned long)head;
256 
257 	err = cb(TC_SETUP_CLSMATCHALL, &cls_mall, cb_priv);
258 	if (err) {
259 		if (add && tc_skip_sw(head->flags))
260 			return err;
261 		return 0;
262 	}
263 
264 	tc_cls_offload_cnt_update(block, &head->in_hw_count, &head->flags, add);
265 
266 	return 0;
267 }
268 
269 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
270 		     struct sk_buff *skb, struct tcmsg *t)
271 {
272 	struct cls_mall_head *head = fh;
273 	struct nlattr *nest;
274 
275 	if (!head)
276 		return skb->len;
277 
278 	t->tcm_handle = head->handle;
279 
280 	nest = nla_nest_start(skb, TCA_OPTIONS);
281 	if (!nest)
282 		goto nla_put_failure;
283 
284 	if (head->res.classid &&
285 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
286 		goto nla_put_failure;
287 
288 	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
289 		goto nla_put_failure;
290 
291 	if (tcf_exts_dump(skb, &head->exts))
292 		goto nla_put_failure;
293 
294 	nla_nest_end(skb, nest);
295 
296 	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
297 		goto nla_put_failure;
298 
299 	return skb->len;
300 
301 nla_put_failure:
302 	nla_nest_cancel(skb, nest);
303 	return -1;
304 }
305 
306 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
307 {
308 	struct cls_mall_head *head = fh;
309 
310 	if (head && head->res.classid == classid)
311 		head->res.class = cl;
312 }
313 
314 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
315 	.kind		= "matchall",
316 	.classify	= mall_classify,
317 	.init		= mall_init,
318 	.destroy	= mall_destroy,
319 	.get		= mall_get,
320 	.change		= mall_change,
321 	.delete		= mall_delete,
322 	.walk		= mall_walk,
323 	.reoffload	= mall_reoffload,
324 	.dump		= mall_dump,
325 	.bind_class	= mall_bind_class,
326 	.owner		= THIS_MODULE,
327 };
328 
329 static int __init cls_mall_init(void)
330 {
331 	return register_tcf_proto_ops(&cls_mall_ops);
332 }
333 
334 static void __exit cls_mall_exit(void)
335 {
336 	unregister_tcf_proto_ops(&cls_mall_ops);
337 }
338 
339 module_init(cls_mall_init);
340 module_exit(cls_mall_exit);
341 
342 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
343 MODULE_DESCRIPTION("Match-all classifier");
344 MODULE_LICENSE("GPL v2");
345