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