xref: /openbmc/linux/net/sched/cls_basic.c (revision 9ffc93f2) 
1 /*
2  * net/sched/cls_basic.c	Basic Packet Classifier.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Authors:	Thomas Graf <tgraf@suug.ch>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/skbuff.h>
20 #include <net/netlink.h>
21 #include <net/act_api.h>
22 #include <net/pkt_cls.h>
23 
24 struct basic_head {
25 	u32			hgenerator;
26 	struct list_head	flist;
27 };
28 
29 struct basic_filter {
30 	u32			handle;
31 	struct tcf_exts		exts;
32 	struct tcf_ematch_tree	ematches;
33 	struct tcf_result	res;
34 	struct list_head	link;
35 };
36 
37 static const struct tcf_ext_map basic_ext_map = {
38 	.action = TCA_BASIC_ACT,
39 	.police = TCA_BASIC_POLICE
40 };
41 
42 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
43 			  struct tcf_result *res)
44 {
45 	int r;
46 	struct basic_head *head = (struct basic_head *) tp->root;
47 	struct basic_filter *f;
48 
49 	list_for_each_entry(f, &head->flist, link) {
50 		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
51 			continue;
52 		*res = f->res;
53 		r = tcf_exts_exec(skb, &f->exts, res);
54 		if (r < 0)
55 			continue;
56 		return r;
57 	}
58 	return -1;
59 }
60 
61 static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
62 {
63 	unsigned long l = 0UL;
64 	struct basic_head *head = (struct basic_head *) tp->root;
65 	struct basic_filter *f;
66 
67 	if (head == NULL)
68 		return 0UL;
69 
70 	list_for_each_entry(f, &head->flist, link)
71 		if (f->handle == handle)
72 			l = (unsigned long) f;
73 
74 	return l;
75 }
76 
77 static void basic_put(struct tcf_proto *tp, unsigned long f)
78 {
79 }
80 
81 static int basic_init(struct tcf_proto *tp)
82 {
83 	struct basic_head *head;
84 
85 	head = kzalloc(sizeof(*head), GFP_KERNEL);
86 	if (head == NULL)
87 		return -ENOBUFS;
88 	INIT_LIST_HEAD(&head->flist);
89 	tp->root = head;
90 	return 0;
91 }
92 
93 static void basic_delete_filter(struct tcf_proto *tp, struct basic_filter *f)
94 {
95 	tcf_unbind_filter(tp, &f->res);
96 	tcf_exts_destroy(tp, &f->exts);
97 	tcf_em_tree_destroy(tp, &f->ematches);
98 	kfree(f);
99 }
100 
101 static void basic_destroy(struct tcf_proto *tp)
102 {
103 	struct basic_head *head = tp->root;
104 	struct basic_filter *f, *n;
105 
106 	list_for_each_entry_safe(f, n, &head->flist, link) {
107 		list_del(&f->link);
108 		basic_delete_filter(tp, f);
109 	}
110 	kfree(head);
111 }
112 
113 static int basic_delete(struct tcf_proto *tp, unsigned long arg)
114 {
115 	struct basic_head *head = (struct basic_head *) tp->root;
116 	struct basic_filter *t, *f = (struct basic_filter *) arg;
117 
118 	list_for_each_entry(t, &head->flist, link)
119 		if (t == f) {
120 			tcf_tree_lock(tp);
121 			list_del(&t->link);
122 			tcf_tree_unlock(tp);
123 			basic_delete_filter(tp, t);
124 			return 0;
125 		}
126 
127 	return -ENOENT;
128 }
129 
130 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
131 	[TCA_BASIC_CLASSID]	= { .type = NLA_U32 },
132 	[TCA_BASIC_EMATCHES]	= { .type = NLA_NESTED },
133 };
134 
135 static int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
136 			   unsigned long base, struct nlattr **tb,
137 			   struct nlattr *est)
138 {
139 	int err = -EINVAL;
140 	struct tcf_exts e;
141 	struct tcf_ematch_tree t;
142 
143 	err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map);
144 	if (err < 0)
145 		return err;
146 
147 	err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t);
148 	if (err < 0)
149 		goto errout;
150 
151 	if (tb[TCA_BASIC_CLASSID]) {
152 		f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
153 		tcf_bind_filter(tp, &f->res, base);
154 	}
155 
156 	tcf_exts_change(tp, &f->exts, &e);
157 	tcf_em_tree_change(tp, &f->ematches, &t);
158 
159 	return 0;
160 errout:
161 	tcf_exts_destroy(tp, &e);
162 	return err;
163 }
164 
165 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
166 			struct nlattr **tca, unsigned long *arg)
167 {
168 	int err;
169 	struct basic_head *head = (struct basic_head *) tp->root;
170 	struct nlattr *tb[TCA_BASIC_MAX + 1];
171 	struct basic_filter *f = (struct basic_filter *) *arg;
172 
173 	if (tca[TCA_OPTIONS] == NULL)
174 		return -EINVAL;
175 
176 	err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
177 			       basic_policy);
178 	if (err < 0)
179 		return err;
180 
181 	if (f != NULL) {
182 		if (handle && f->handle != handle)
183 			return -EINVAL;
184 		return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
185 	}
186 
187 	err = -ENOBUFS;
188 	f = kzalloc(sizeof(*f), GFP_KERNEL);
189 	if (f == NULL)
190 		goto errout;
191 
192 	err = -EINVAL;
193 	if (handle)
194 		f->handle = handle;
195 	else {
196 		unsigned int i = 0x80000000;
197 		do {
198 			if (++head->hgenerator == 0x7FFFFFFF)
199 				head->hgenerator = 1;
200 		} while (--i > 0 && basic_get(tp, head->hgenerator));
201 
202 		if (i <= 0) {
203 			pr_err("Insufficient number of handles\n");
204 			goto errout;
205 		}
206 
207 		f->handle = head->hgenerator;
208 	}
209 
210 	err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
211 	if (err < 0)
212 		goto errout;
213 
214 	tcf_tree_lock(tp);
215 	list_add(&f->link, &head->flist);
216 	tcf_tree_unlock(tp);
217 	*arg = (unsigned long) f;
218 
219 	return 0;
220 errout:
221 	if (*arg == 0UL && f)
222 		kfree(f);
223 
224 	return err;
225 }
226 
227 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
228 {
229 	struct basic_head *head = (struct basic_head *) tp->root;
230 	struct basic_filter *f;
231 
232 	list_for_each_entry(f, &head->flist, link) {
233 		if (arg->count < arg->skip)
234 			goto skip;
235 
236 		if (arg->fn(tp, (unsigned long) f, arg) < 0) {
237 			arg->stop = 1;
238 			break;
239 		}
240 skip:
241 		arg->count++;
242 	}
243 }
244 
245 static int basic_dump(struct tcf_proto *tp, unsigned long fh,
246 		      struct sk_buff *skb, struct tcmsg *t)
247 {
248 	struct basic_filter *f = (struct basic_filter *) fh;
249 	struct nlattr *nest;
250 
251 	if (f == NULL)
252 		return skb->len;
253 
254 	t->tcm_handle = f->handle;
255 
256 	nest = nla_nest_start(skb, TCA_OPTIONS);
257 	if (nest == NULL)
258 		goto nla_put_failure;
259 
260 	if (f->res.classid)
261 		NLA_PUT_U32(skb, TCA_BASIC_CLASSID, f->res.classid);
262 
263 	if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 ||
264 	    tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
265 		goto nla_put_failure;
266 
267 	nla_nest_end(skb, nest);
268 
269 	if (tcf_exts_dump_stats(skb, &f->exts, &basic_ext_map) < 0)
270 		goto nla_put_failure;
271 
272 	return skb->len;
273 
274 nla_put_failure:
275 	nla_nest_cancel(skb, nest);
276 	return -1;
277 }
278 
279 static struct tcf_proto_ops cls_basic_ops __read_mostly = {
280 	.kind		=	"basic",
281 	.classify	=	basic_classify,
282 	.init		=	basic_init,
283 	.destroy	=	basic_destroy,
284 	.get		=	basic_get,
285 	.put		=	basic_put,
286 	.change		=	basic_change,
287 	.delete		=	basic_delete,
288 	.walk		=	basic_walk,
289 	.dump		=	basic_dump,
290 	.owner		=	THIS_MODULE,
291 };
292 
293 static int __init init_basic(void)
294 {
295 	return register_tcf_proto_ops(&cls_basic_ops);
296 }
297 
298 static void __exit exit_basic(void)
299 {
300 	unregister_tcf_proto_ops(&cls_basic_ops);
301 }
302 
303 module_init(init_basic)
304 module_exit(exit_basic)
305 MODULE_LICENSE("GPL");
306 
307