xref: /linux/net/sched/cls_matchall.c (revision 995231c820e3bd3633cb38bf4ea6f2541e1da331)
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 	struct rcu_head	rcu;
25 };
26 
27 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
28 			 struct tcf_result *res)
29 {
30 	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
31 
32 	if (tc_skip_sw(head->flags))
33 		return -1;
34 
35 	*res = head->res;
36 	return tcf_exts_exec(skb, &head->exts, res);
37 }
38 
39 static int mall_init(struct tcf_proto *tp)
40 {
41 	return 0;
42 }
43 
44 static void mall_destroy_rcu(struct rcu_head *rcu)
45 {
46 	struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
47 						  rcu);
48 
49 	tcf_exts_destroy(&head->exts);
50 	kfree(head);
51 }
52 
53 static void mall_destroy_hw_filter(struct tcf_proto *tp,
54 				   struct cls_mall_head *head,
55 				   unsigned long cookie)
56 {
57 	struct tc_cls_matchall_offload cls_mall = {};
58 	struct tcf_block *block = tp->chain->block;
59 
60 	tc_cls_common_offload_init(&cls_mall.common, tp);
61 	cls_mall.command = TC_CLSMATCHALL_DESTROY;
62 	cls_mall.cookie = cookie;
63 
64 	tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
65 }
66 
67 static int mall_replace_hw_filter(struct tcf_proto *tp,
68 				  struct cls_mall_head *head,
69 				  unsigned long cookie)
70 {
71 	struct tc_cls_matchall_offload cls_mall = {};
72 	struct tcf_block *block = tp->chain->block;
73 	bool skip_sw = tc_skip_sw(head->flags);
74 	int err;
75 
76 	tc_cls_common_offload_init(&cls_mall.common, tp);
77 	cls_mall.command = TC_CLSMATCHALL_REPLACE;
78 	cls_mall.exts = &head->exts;
79 	cls_mall.cookie = cookie;
80 
81 	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
82 			       &cls_mall, skip_sw);
83 	if (err < 0) {
84 		mall_destroy_hw_filter(tp, head, cookie);
85 		return err;
86 	} else if (err > 0) {
87 		head->flags |= TCA_CLS_FLAGS_IN_HW;
88 	}
89 
90 	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
91 		return -EINVAL;
92 
93 	return 0;
94 }
95 
96 static void mall_destroy(struct tcf_proto *tp)
97 {
98 	struct cls_mall_head *head = rtnl_dereference(tp->root);
99 
100 	if (!head)
101 		return;
102 
103 	if (!tc_skip_hw(head->flags))
104 		mall_destroy_hw_filter(tp, head, (unsigned long) head);
105 
106 	call_rcu(&head->rcu, mall_destroy_rcu);
107 }
108 
109 static void *mall_get(struct tcf_proto *tp, u32 handle)
110 {
111 	return NULL;
112 }
113 
114 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
115 	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
116 	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
117 };
118 
119 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
120 			  struct cls_mall_head *head,
121 			  unsigned long base, struct nlattr **tb,
122 			  struct nlattr *est, bool ovr)
123 {
124 	int err;
125 
126 	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
127 	if (err < 0)
128 		return err;
129 
130 	if (tb[TCA_MATCHALL_CLASSID]) {
131 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
132 		tcf_bind_filter(tp, &head->res, base);
133 	}
134 	return 0;
135 }
136 
137 static int mall_change(struct net *net, struct sk_buff *in_skb,
138 		       struct tcf_proto *tp, unsigned long base,
139 		       u32 handle, struct nlattr **tca,
140 		       void **arg, bool ovr)
141 {
142 	struct cls_mall_head *head = rtnl_dereference(tp->root);
143 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
144 	struct cls_mall_head *new;
145 	u32 flags = 0;
146 	int err;
147 
148 	if (!tca[TCA_OPTIONS])
149 		return -EINVAL;
150 
151 	if (head)
152 		return -EEXIST;
153 
154 	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
155 			       mall_policy, NULL);
156 	if (err < 0)
157 		return err;
158 
159 	if (tb[TCA_MATCHALL_FLAGS]) {
160 		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
161 		if (!tc_flags_valid(flags))
162 			return -EINVAL;
163 	}
164 
165 	new = kzalloc(sizeof(*new), GFP_KERNEL);
166 	if (!new)
167 		return -ENOBUFS;
168 
169 	err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
170 	if (err)
171 		goto err_exts_init;
172 
173 	if (!handle)
174 		handle = 1;
175 	new->handle = handle;
176 	new->flags = flags;
177 
178 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
179 	if (err)
180 		goto err_set_parms;
181 
182 	if (!tc_skip_hw(new->flags)) {
183 		err = mall_replace_hw_filter(tp, new, (unsigned long) new);
184 		if (err)
185 			goto err_replace_hw_filter;
186 	}
187 
188 	if (!tc_in_hw(new->flags))
189 		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
190 
191 	*arg = head;
192 	rcu_assign_pointer(tp->root, new);
193 	return 0;
194 
195 err_replace_hw_filter:
196 err_set_parms:
197 	tcf_exts_destroy(&new->exts);
198 err_exts_init:
199 	kfree(new);
200 	return err;
201 }
202 
203 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last)
204 {
205 	return -EOPNOTSUPP;
206 }
207 
208 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
209 {
210 	struct cls_mall_head *head = rtnl_dereference(tp->root);
211 
212 	if (arg->count < arg->skip)
213 		goto skip;
214 	if (arg->fn(tp, head, arg) < 0)
215 		arg->stop = 1;
216 skip:
217 	arg->count++;
218 }
219 
220 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
221 		     struct sk_buff *skb, struct tcmsg *t)
222 {
223 	struct cls_mall_head *head = fh;
224 	struct nlattr *nest;
225 
226 	if (!head)
227 		return skb->len;
228 
229 	t->tcm_handle = head->handle;
230 
231 	nest = nla_nest_start(skb, TCA_OPTIONS);
232 	if (!nest)
233 		goto nla_put_failure;
234 
235 	if (head->res.classid &&
236 	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
237 		goto nla_put_failure;
238 
239 	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
240 		goto nla_put_failure;
241 
242 	if (tcf_exts_dump(skb, &head->exts))
243 		goto nla_put_failure;
244 
245 	nla_nest_end(skb, nest);
246 
247 	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
248 		goto nla_put_failure;
249 
250 	return skb->len;
251 
252 nla_put_failure:
253 	nla_nest_cancel(skb, nest);
254 	return -1;
255 }
256 
257 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
258 {
259 	struct cls_mall_head *head = fh;
260 
261 	if (head && head->res.classid == classid)
262 		head->res.class = cl;
263 }
264 
265 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
266 	.kind		= "matchall",
267 	.classify	= mall_classify,
268 	.init		= mall_init,
269 	.destroy	= mall_destroy,
270 	.get		= mall_get,
271 	.change		= mall_change,
272 	.delete		= mall_delete,
273 	.walk		= mall_walk,
274 	.dump		= mall_dump,
275 	.bind_class	= mall_bind_class,
276 	.owner		= THIS_MODULE,
277 };
278 
279 static int __init cls_mall_init(void)
280 {
281 	return register_tcf_proto_ops(&cls_mall_ops);
282 }
283 
284 static void __exit cls_mall_exit(void)
285 {
286 	unregister_tcf_proto_ops(&cls_mall_ops);
287 }
288 
289 module_init(cls_mall_init);
290 module_exit(cls_mall_exit);
291 
292 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
293 MODULE_DESCRIPTION("Match-all classifier");
294 MODULE_LICENSE("GPL v2");
295