xref: /linux/net/sched/cls_fw.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076) 
1 /*
2  * net/sched/cls_fw.c	Classifier mapping ipchains' fwmark to traffic class.
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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *
11  * Changes:
12  * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
13  * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
14  * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
15  *
16  * JHS: We should remove the CONFIG_NET_CLS_IND from here
17  * eventually when the meta match extension is made available
18  *
19  */
20 
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kernel.h>
24 #include <linux/string.h>
25 #include <linux/errno.h>
26 #include <linux/skbuff.h>
27 #include <net/netlink.h>
28 #include <net/act_api.h>
29 #include <net/pkt_cls.h>
30 
31 #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
32 
33 struct fw_head
34 {
35 	struct fw_filter *ht[HTSIZE];
36 	u32 mask;
37 };
38 
39 struct fw_filter
40 {
41 	struct fw_filter	*next;
42 	u32			id;
43 	struct tcf_result	res;
44 #ifdef CONFIG_NET_CLS_IND
45 	char			indev[IFNAMSIZ];
46 #endif /* CONFIG_NET_CLS_IND */
47 	struct tcf_exts		exts;
48 };
49 
50 static const struct tcf_ext_map fw_ext_map = {
51 	.action = TCA_FW_ACT,
52 	.police = TCA_FW_POLICE
53 };
54 
55 static __inline__ int fw_hash(u32 handle)
56 {
57 	if (HTSIZE == 4096)
58 		return ((handle >> 24) & 0xFFF) ^
59 		       ((handle >> 12) & 0xFFF) ^
60 		       (handle & 0xFFF);
61 	else if (HTSIZE == 2048)
62 		return ((handle >> 22) & 0x7FF) ^
63 		       ((handle >> 11) & 0x7FF) ^
64 		       (handle & 0x7FF);
65 	else if (HTSIZE == 1024)
66 		return ((handle >> 20) & 0x3FF) ^
67 		       ((handle >> 10) & 0x3FF) ^
68 		       (handle & 0x3FF);
69 	else if (HTSIZE == 512)
70 		return (handle >> 27) ^
71 		       ((handle >> 18) & 0x1FF) ^
72 		       ((handle >> 9) & 0x1FF) ^
73 		       (handle & 0x1FF);
74 	else if (HTSIZE == 256) {
75 		u8 *t = (u8 *) &handle;
76 		return t[0] ^ t[1] ^ t[2] ^ t[3];
77 	} else
78 		return handle & (HTSIZE - 1);
79 }
80 
81 static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
82 			  struct tcf_result *res)
83 {
84 	struct fw_head *head = (struct fw_head*)tp->root;
85 	struct fw_filter *f;
86 	int r;
87 	u32 id = skb->mark;
88 
89 	if (head != NULL) {
90 		id &= head->mask;
91 		for (f=head->ht[fw_hash(id)]; f; f=f->next) {
92 			if (f->id == id) {
93 				*res = f->res;
94 #ifdef CONFIG_NET_CLS_IND
95 				if (!tcf_match_indev(skb, f->indev))
96 					continue;
97 #endif /* CONFIG_NET_CLS_IND */
98 				r = tcf_exts_exec(skb, &f->exts, res);
99 				if (r < 0)
100 					continue;
101 
102 				return r;
103 			}
104 		}
105 	} else {
106 		/* old method */
107 		if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
108 			res->classid = id;
109 			res->class = 0;
110 			return 0;
111 		}
112 	}
113 
114 	return -1;
115 }
116 
117 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
118 {
119 	struct fw_head *head = (struct fw_head*)tp->root;
120 	struct fw_filter *f;
121 
122 	if (head == NULL)
123 		return 0;
124 
125 	for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
126 		if (f->id == handle)
127 			return (unsigned long)f;
128 	}
129 	return 0;
130 }
131 
132 static void fw_put(struct tcf_proto *tp, unsigned long f)
133 {
134 }
135 
136 static int fw_init(struct tcf_proto *tp)
137 {
138 	return 0;
139 }
140 
141 static inline void
142 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
143 {
144 	tcf_unbind_filter(tp, &f->res);
145 	tcf_exts_destroy(tp, &f->exts);
146 	kfree(f);
147 }
148 
149 static void fw_destroy(struct tcf_proto *tp)
150 {
151 	struct fw_head *head = tp->root;
152 	struct fw_filter *f;
153 	int h;
154 
155 	if (head == NULL)
156 		return;
157 
158 	for (h=0; h<HTSIZE; h++) {
159 		while ((f=head->ht[h]) != NULL) {
160 			head->ht[h] = f->next;
161 			fw_delete_filter(tp, f);
162 		}
163 	}
164 	kfree(head);
165 }
166 
167 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
168 {
169 	struct fw_head *head = (struct fw_head*)tp->root;
170 	struct fw_filter *f = (struct fw_filter*)arg;
171 	struct fw_filter **fp;
172 
173 	if (head == NULL || f == NULL)
174 		goto out;
175 
176 	for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
177 		if (*fp == f) {
178 			tcf_tree_lock(tp);
179 			*fp = f->next;
180 			tcf_tree_unlock(tp);
181 			fw_delete_filter(tp, f);
182 			return 0;
183 		}
184 	}
185 out:
186 	return -EINVAL;
187 }
188 
189 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
190 	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
191 	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
192 	[TCA_FW_MASK]		= { .type = NLA_U32 },
193 };
194 
195 static int
196 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
197 	struct nlattr **tb, struct nlattr **tca, unsigned long base)
198 {
199 	struct fw_head *head = (struct fw_head *)tp->root;
200 	struct tcf_exts e;
201 	u32 mask;
202 	int err;
203 
204 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
205 	if (err < 0)
206 		return err;
207 
208 	err = -EINVAL;
209 	if (tb[TCA_FW_CLASSID]) {
210 		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
211 		tcf_bind_filter(tp, &f->res, base);
212 	}
213 
214 #ifdef CONFIG_NET_CLS_IND
215 	if (tb[TCA_FW_INDEV]) {
216 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
217 		if (err < 0)
218 			goto errout;
219 	}
220 #endif /* CONFIG_NET_CLS_IND */
221 
222 	if (tb[TCA_FW_MASK]) {
223 		mask = nla_get_u32(tb[TCA_FW_MASK]);
224 		if (mask != head->mask)
225 			goto errout;
226 	} else if (head->mask != 0xFFFFFFFF)
227 		goto errout;
228 
229 	tcf_exts_change(tp, &f->exts, &e);
230 
231 	return 0;
232 errout:
233 	tcf_exts_destroy(tp, &e);
234 	return err;
235 }
236 
237 static int fw_change(struct tcf_proto *tp, unsigned long base,
238 		     u32 handle,
239 		     struct nlattr **tca,
240 		     unsigned long *arg)
241 {
242 	struct fw_head *head = (struct fw_head*)tp->root;
243 	struct fw_filter *f = (struct fw_filter *) *arg;
244 	struct nlattr *opt = tca[TCA_OPTIONS];
245 	struct nlattr *tb[TCA_FW_MAX + 1];
246 	int err;
247 
248 	if (!opt)
249 		return handle ? -EINVAL : 0;
250 
251 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
252 	if (err < 0)
253 		return err;
254 
255 	if (f != NULL) {
256 		if (f->id != handle && handle)
257 			return -EINVAL;
258 		return fw_change_attrs(tp, f, tb, tca, base);
259 	}
260 
261 	if (!handle)
262 		return -EINVAL;
263 
264 	if (head == NULL) {
265 		u32 mask = 0xFFFFFFFF;
266 		if (tb[TCA_FW_MASK])
267 			mask = nla_get_u32(tb[TCA_FW_MASK]);
268 
269 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
270 		if (head == NULL)
271 			return -ENOBUFS;
272 		head->mask = mask;
273 
274 		tcf_tree_lock(tp);
275 		tp->root = head;
276 		tcf_tree_unlock(tp);
277 	}
278 
279 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
280 	if (f == NULL)
281 		return -ENOBUFS;
282 
283 	f->id = handle;
284 
285 	err = fw_change_attrs(tp, f, tb, tca, base);
286 	if (err < 0)
287 		goto errout;
288 
289 	f->next = head->ht[fw_hash(handle)];
290 	tcf_tree_lock(tp);
291 	head->ht[fw_hash(handle)] = f;
292 	tcf_tree_unlock(tp);
293 
294 	*arg = (unsigned long)f;
295 	return 0;
296 
297 errout:
298 	kfree(f);
299 	return err;
300 }
301 
302 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
303 {
304 	struct fw_head *head = (struct fw_head*)tp->root;
305 	int h;
306 
307 	if (head == NULL)
308 		arg->stop = 1;
309 
310 	if (arg->stop)
311 		return;
312 
313 	for (h = 0; h < HTSIZE; h++) {
314 		struct fw_filter *f;
315 
316 		for (f = head->ht[h]; f; f = f->next) {
317 			if (arg->count < arg->skip) {
318 				arg->count++;
319 				continue;
320 			}
321 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
322 				arg->stop = 1;
323 				return;
324 			}
325 			arg->count++;
326 		}
327 	}
328 }
329 
330 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
331 		   struct sk_buff *skb, struct tcmsg *t)
332 {
333 	struct fw_head *head = (struct fw_head *)tp->root;
334 	struct fw_filter *f = (struct fw_filter*)fh;
335 	unsigned char *b = skb_tail_pointer(skb);
336 	struct nlattr *nest;
337 
338 	if (f == NULL)
339 		return skb->len;
340 
341 	t->tcm_handle = f->id;
342 
343 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
344 		return skb->len;
345 
346 	nest = nla_nest_start(skb, TCA_OPTIONS);
347 	if (nest == NULL)
348 		goto nla_put_failure;
349 
350 	if (f->res.classid)
351 		NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
352 #ifdef CONFIG_NET_CLS_IND
353 	if (strlen(f->indev))
354 		NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
355 #endif /* CONFIG_NET_CLS_IND */
356 	if (head->mask != 0xFFFFFFFF)
357 		NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);
358 
359 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
360 		goto nla_put_failure;
361 
362 	nla_nest_end(skb, nest);
363 
364 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
365 		goto nla_put_failure;
366 
367 	return skb->len;
368 
369 nla_put_failure:
370 	nlmsg_trim(skb, b);
371 	return -1;
372 }
373 
374 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
375 	.kind		=	"fw",
376 	.classify	=	fw_classify,
377 	.init		=	fw_init,
378 	.destroy	=	fw_destroy,
379 	.get		=	fw_get,
380 	.put		=	fw_put,
381 	.change		=	fw_change,
382 	.delete		=	fw_delete,
383 	.walk		=	fw_walk,
384 	.dump		=	fw_dump,
385 	.owner		=	THIS_MODULE,
386 };
387 
388 static int __init init_fw(void)
389 {
390 	return register_tcf_proto_ops(&cls_fw_ops);
391 }
392 
393 static void __exit exit_fw(void)
394 {
395 	unregister_tcf_proto_ops(&cls_fw_ops);
396 }
397 
398 module_init(init_fw)
399 module_exit(exit_fw)
400 MODULE_LICENSE("GPL");
401