xref: /linux/net/sched/cls_matchall.c (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
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 	union {
25 		struct work_struct work;
26 		struct rcu_head	rcu;
27 	};
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 	return tcf_exts_exec(skb, &head->exts, res);
40 }
41 
42 static int mall_init(struct tcf_proto *tp)
43 {
44 	return 0;
45 }
46 
47 static void __mall_destroy(struct cls_mall_head *head)
48 {
49 	tcf_exts_destroy(&head->exts);
50 	tcf_exts_put_net(&head->exts);
51 	kfree(head);
52 }
53 
54 static void mall_destroy_work(struct work_struct *work)
55 {
56 	struct cls_mall_head *head = container_of(work, struct cls_mall_head,
57 						  work);
58 	rtnl_lock();
59 	__mall_destroy(head);
60 	rtnl_unlock();
61 }
62 
63 static void mall_destroy_rcu(struct rcu_head *rcu)
64 {
65 	struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
66 						  rcu);
67 
68 	INIT_WORK(&head->work, mall_destroy_work);
69 	tcf_queue_work(&head->work);
70 }
71 
72 static void mall_destroy_hw_filter(struct tcf_proto *tp,
73 				   struct cls_mall_head *head,
74 				   unsigned long cookie,
75 				   struct netlink_ext_ack *extack)
76 {
77 	struct tc_cls_matchall_offload cls_mall = {};
78 	struct tcf_block *block = tp->chain->block;
79 
80 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
81 	cls_mall.command = TC_CLSMATCHALL_DESTROY;
82 	cls_mall.cookie = cookie;
83 
84 	tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
85 	tcf_block_offload_dec(block, &head->flags);
86 }
87 
88 static int mall_replace_hw_filter(struct tcf_proto *tp,
89 				  struct cls_mall_head *head,
90 				  unsigned long cookie,
91 				  struct netlink_ext_ack *extack)
92 {
93 	struct tc_cls_matchall_offload cls_mall = {};
94 	struct tcf_block *block = tp->chain->block;
95 	bool skip_sw = tc_skip_sw(head->flags);
96 	int err;
97 
98 	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
99 	cls_mall.command = TC_CLSMATCHALL_REPLACE;
100 	cls_mall.exts = &head->exts;
101 	cls_mall.cookie = cookie;
102 
103 	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
104 			       &cls_mall, skip_sw);
105 	if (err < 0) {
106 		mall_destroy_hw_filter(tp, head, cookie, NULL);
107 		return err;
108 	} else if (err > 0) {
109 		tcf_block_offload_inc(block, &head->flags);
110 	}
111 
112 	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
113 		return -EINVAL;
114 
115 	return 0;
116 }
117 
118 static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
119 {
120 	struct cls_mall_head *head = rtnl_dereference(tp->root);
121 
122 	if (!head)
123 		return;
124 
125 	if (!tc_skip_hw(head->flags))
126 		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);
127 
128 	if (tcf_exts_get_net(&head->exts))
129 		call_rcu(&head->rcu, mall_destroy_rcu);
130 	else
131 		__mall_destroy(head);
132 }
133 
134 static void *mall_get(struct tcf_proto *tp, u32 handle)
135 {
136 	return NULL;
137 }
138 
139 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
140 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
141 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
142 };
143 
144 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
145 			  struct cls_mall_head *head,
146 			  unsigned long base, struct nlattr **tb,
147 			  struct nlattr *est, bool ovr,
148 			  struct netlink_ext_ack *extack)
149 {
150 	int err;
151 
152 	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
153 	if (err < 0)
154 		return err;
155 
156 	if (tb[TCA_MATCHALL_CLASSID]) {
157 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
158 		tcf_bind_filter(tp, &head->res, base);
159 	}
160 	return 0;
161 }
162 
163 static int mall_change(struct net *net, struct sk_buff *in_skb,
164 		       struct tcf_proto *tp, unsigned long base,
165 		       u32 handle, struct nlattr **tca,
166 		       void **arg, bool ovr, struct netlink_ext_ack *extack)
167 {
168 	struct cls_mall_head *head = rtnl_dereference(tp->root);
169 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
170 	struct cls_mall_head *new;
171 	u32 flags = 0;
172 	int err;
173 
174 	if (!tca[TCA_OPTIONS])
175 		return -EINVAL;
176 
177 	if (head)
178 		return -EEXIST;
179 
180 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
181 			       mall_policy, NULL);
182 	if (err < 0)
183 		return err;
184 
185 	if (tb[TCA_MATCHALL_FLAGS]) {
186 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
187 		if (!tc_flags_valid(flags))
188 			return -EINVAL;
189 	}
190 
191 	new = kzalloc(sizeof(*new), GFP_KERNEL);
192 	if (!new)
193 		return -ENOBUFS;
194 
195 	err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
196 	if (err)
197 		goto err_exts_init;
198 
199 	if (!handle)
200 		handle = 1;
201 	new->handle = handle;
202 	new->flags = flags;
203 
204 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
205 			     extack);
206 	if (err)
207 		goto err_set_parms;
208 
209 	if (!tc_skip_hw(new->flags)) {
210 		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
211 					     extack);
212 		if (err)
213 			goto err_replace_hw_filter;
214 	}
215 
216 	if (!tc_in_hw(new->flags))
217 		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
218 
219 	*arg = head;
220 	rcu_assign_pointer(tp->root, new);
221 	return 0;
222 
223 err_replace_hw_filter:
224 err_set_parms:
225 	tcf_exts_destroy(&new->exts);
226 err_exts_init:
227 	kfree(new);
228 	return err;
229 }
230 
231 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
232 		       struct netlink_ext_ack *extack)
233 {
234 	return -EOPNOTSUPP;
235 }
236 
237 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
238 {
239 	struct cls_mall_head *head = rtnl_dereference(tp->root);
240 
241 	if (arg->count < arg->skip)
242 		goto skip;
243 	if (arg->fn(tp, head, arg) < 0)
244 		arg->stop = 1;
245 skip:
246 	arg->count++;
247 }
248 
249 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
250 		     struct sk_buff *skb, struct tcmsg *t)
251 {
252 	struct cls_mall_head *head = fh;
253 	struct nlattr *nest;
254 
255 	if (!head)
256 		return skb->len;
257 
258 	t->tcm_handle = head->handle;
259 
260 	nest = nla_nest_start(skb, TCA_OPTIONS);
261 	if (!nest)
262 		goto nla_put_failure;
263 
264 	if (head->res.classid &&
265 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
266 		goto nla_put_failure;
267 
268 	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
269 		goto nla_put_failure;
270 
271 	if (tcf_exts_dump(skb, &head->exts))
272 		goto nla_put_failure;
273 
274 	nla_nest_end(skb, nest);
275 
276 	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
277 		goto nla_put_failure;
278 
279 	return skb->len;
280 
281 nla_put_failure:
282 	nla_nest_cancel(skb, nest);
283 	return -1;
284 }
285 
286 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
287 {
288 	struct cls_mall_head *head = fh;
289 
290 	if (head && head->res.classid == classid)
291 		head->res.class = cl;
292 }
293 
294 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
295 	.kind		= "matchall",
296 	.classify	= mall_classify,
297 	.init		= mall_init,
298 	.destroy	= mall_destroy,
299 	.get		= mall_get,
300 	.change		= mall_change,
301 	.delete		= mall_delete,
302 	.walk		= mall_walk,
303 	.dump		= mall_dump,
304 	.bind_class	= mall_bind_class,
305 	.owner		= THIS_MODULE,
306 };
307 
308 static int __init cls_mall_init(void)
309 {
310 	return register_tcf_proto_ops(&cls_mall_ops);
311 }
312 
313 static void __exit cls_mall_exit(void)
314 {
315 	unregister_tcf_proto_ops(&cls_mall_ops);
316 }
317 
318 module_init(cls_mall_init);
319 module_exit(cls_mall_exit);
320 
321 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
322 MODULE_DESCRIPTION("Match-all classifier");
323 MODULE_LICENSE("GPL v2");
324