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 struct rcu_head rcu;
28 };
29
30 struct basic_filter {
31 u32 handle;
32 struct tcf_exts exts;
33 struct tcf_ematch_tree ematches;
34 struct tcf_result res;
35 struct tcf_proto *tp;
36 struct list_head link;
37 struct rcu_head rcu;
38 };
39
40 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
41 struct tcf_result *res)
42 {
43 int r;
44 struct basic_head *head = rcu_dereference_bh(tp->root);
45 struct basic_filter *f;
46
47 list_for_each_entry_rcu(f, &head->flist, link) {
48 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
49 continue;
50 *res = f->res;
51 r = tcf_exts_exec(skb, &f->exts, res);
52 if (r < 0)
53 continue;
54 return r;
55 }
56 return -1;
57 }
58
59 static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
60 {
61 unsigned long l = 0UL;
62 struct basic_head *head = rtnl_dereference(tp->root);
63 struct basic_filter *f;
64
65 list_for_each_entry(f, &head->flist, link) {
66 if (f->handle == handle) {
67 l = (unsigned long) f;
68 break;
69 }
70 }
71
72 return l;
73 }
74
75 static int basic_init(struct tcf_proto *tp)
76 {
77 struct basic_head *head;
78
79 head = kzalloc(sizeof(*head), GFP_KERNEL);
80 if (head == NULL)
81 return -ENOBUFS;
82 INIT_LIST_HEAD(&head->flist);
83 rcu_assign_pointer(tp->root, head);
84 return 0;
85 }
86
87 static void basic_delete_filter(struct rcu_head *head)
88 {
89 struct basic_filter *f = container_of(head, struct basic_filter, rcu);
90
91 tcf_exts_destroy(&f->exts);
92 tcf_em_tree_destroy(&f->ematches);
93 kfree(f);
94 }
95
96 static void basic_destroy(struct tcf_proto *tp)
97 {
98 struct basic_head *head = rtnl_dereference(tp->root);
99 struct basic_filter *f, *n;
100
101 list_for_each_entry_safe(f, n, &head->flist, link) {
102 list_del_rcu(&f->link);
103 tcf_unbind_filter(tp, &f->res);
104 call_rcu(&f->rcu, basic_delete_filter);
105 }
106 kfree_rcu(head, rcu);
107 }
108
109 static int basic_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
110 {
111 struct basic_head *head = rtnl_dereference(tp->root);
112 struct basic_filter *f = (struct basic_filter *) arg;
113
114 list_del_rcu(&f->link);
115 tcf_unbind_filter(tp, &f->res);
116 call_rcu(&f->rcu, basic_delete_filter);
117 *last = list_empty(&head->flist);
118 return 0;
119 }
120
121 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
122 [TCA_BASIC_CLASSID] = { .type = NLA_U32 },
123 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED },
124 };
125
126 static int basic_set_parms(struct net *net, struct tcf_proto *tp,
127 struct basic_filter *f, unsigned long base,
128 struct nlattr **tb,
129 struct nlattr *est, bool ovr)
130 {
131 int err;
132 struct tcf_exts e;
133 struct tcf_ematch_tree t;
134
135 err = tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE);
136 if (err < 0)
137 return err;
138 err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
139 if (err < 0)
140 goto errout;
141
142 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t);
143 if (err < 0)
144 goto errout;
145
146 if (tb[TCA_BASIC_CLASSID]) {
147 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
148 tcf_bind_filter(tp, &f->res, base);
149 }
150
151 tcf_exts_change(tp, &f->exts, &e);
152 tcf_em_tree_change(tp, &f->ematches, &t);
153 f->tp = tp;
154
155 return 0;
156 errout:
157 tcf_exts_destroy(&e);
158 return err;
159 }
160
161 static int basic_change(struct net *net, struct sk_buff *in_skb,
162 struct tcf_proto *tp, unsigned long base, u32 handle,
163 struct nlattr **tca, unsigned long *arg, bool ovr)
164 {
165 int err;
166 struct basic_head *head = rtnl_dereference(tp->root);
167 struct nlattr *tb[TCA_BASIC_MAX + 1];
168 struct basic_filter *fold = (struct basic_filter *) *arg;
169 struct basic_filter *fnew;
170
171 if (tca[TCA_OPTIONS] == NULL)
172 return -EINVAL;
173
174 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
175 basic_policy, NULL);
176 if (err < 0)
177 return err;
178
179 if (fold != NULL) {
180 if (handle && fold->handle != handle)
181 return -EINVAL;
182 }
183
184 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
185 if (!fnew)
186 return -ENOBUFS;
187
188 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE);
189 if (err < 0)
190 goto errout;
191
192 err = -EINVAL;
193 if (handle) {
194 fnew->handle = handle;
195 } else if (fold) {
196 fnew->handle = fold->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 pr_err("Insufficient number of handles\n");
206 goto errout;
207 }
208
209 fnew->handle = head->hgenerator;
210 }
211
212 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr);
213 if (err < 0)
214 goto errout;
215
216 *arg = (unsigned long)fnew;
217
218 if (fold) {
219 list_replace_rcu(&fold->link, &fnew->link);
220 tcf_unbind_filter(tp, &fold->res);
221 call_rcu(&fold->rcu, basic_delete_filter);
222 } else {
223 list_add_rcu(&fnew->link, &head->flist);
224 }
225
226 return 0;
227 errout:
228 tcf_exts_destroy(&fnew->exts);
229 kfree(fnew);
230 return err;
231 }
232
233 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
234 {
235 struct basic_head *head = rtnl_dereference(tp->root);
236 struct basic_filter *f;
237
238 list_for_each_entry(f, &head->flist, link) {
239 if (arg->count < arg->skip)
240 goto skip;
241
242 if (arg->fn(tp, (unsigned long) f, arg) < 0) {
243 arg->stop = 1;
244 break;
245 }
246 skip:
247 arg->count++;
248 }
249 }
250
251 static int basic_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
252 struct sk_buff *skb, struct tcmsg *t)
253 {
254 struct basic_filter *f = (struct basic_filter *) fh;
255 struct nlattr *nest;
256
257 if (f == NULL)
258 return skb->len;
259
260 t->tcm_handle = f->handle;
261
262 nest = nla_nest_start(skb, TCA_OPTIONS);
263 if (nest == NULL)
264 goto nla_put_failure;
265
266 if (f->res.classid &&
267 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid))
268 goto nla_put_failure;
269
270 if (tcf_exts_dump(skb, &f->exts) < 0 ||
271 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
272 goto nla_put_failure;
273
274 nla_nest_end(skb, nest);
275
276 if (tcf_exts_dump_stats(skb, &f->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 struct tcf_proto_ops cls_basic_ops __read_mostly = {
287 .kind = "basic",
288 .classify = basic_classify,
289 .init = basic_init,
290 .destroy = basic_destroy,
291 .get = basic_get,
292 .change = basic_change,
293 .delete = basic_delete,
294 .walk = basic_walk,
295 .dump = basic_dump,
296 .owner = THIS_MODULE,
297 };
298
299 static int __init init_basic(void)
300 {
301 return register_tcf_proto_ops(&cls_basic_ops);
302 }
303
304 static void __exit exit_basic(void)
305 {
306 unregister_tcf_proto_ops(&cls_basic_ops);
307 }
308
309 module_init(init_basic)
310 module_exit(exit_basic)
311 MODULE_LICENSE("GPL");
312
313
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