xref: /linux/net/sched/cls_fw.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d) 
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/slab.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
25 #include <linux/string.h>
26 #include <linux/errno.h>
27 #include <linux/skbuff.h>
28 #include <net/netlink.h>
29 #include <net/act_api.h>
30 #include <net/pkt_cls.h>
31 
32 #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
33 
34 struct fw_head {
35 	struct fw_filter *ht[HTSIZE];
36 	u32 mask;
37 };
38 
39 struct fw_filter {
40 	struct fw_filter	*next;
41 	u32			id;
42 	struct tcf_result	res;
43 #ifdef CONFIG_NET_CLS_IND
44 	char			indev[IFNAMSIZ];
45 #endif /* CONFIG_NET_CLS_IND */
46 	struct tcf_exts		exts;
47 };
48 
49 static const struct tcf_ext_map fw_ext_map = {
50 	.action = TCA_FW_ACT,
51 	.police = TCA_FW_POLICE
52 };
53 
54 static inline int fw_hash(u32 handle)
55 {
56 	if (HTSIZE == 4096)
57 		return ((handle >> 24) & 0xFFF) ^
58 		       ((handle >> 12) & 0xFFF) ^
59 		       (handle & 0xFFF);
60 	else if (HTSIZE == 2048)
61 		return ((handle >> 22) & 0x7FF) ^
62 		       ((handle >> 11) & 0x7FF) ^
63 		       (handle & 0x7FF);
64 	else if (HTSIZE == 1024)
65 		return ((handle >> 20) & 0x3FF) ^
66 		       ((handle >> 10) & 0x3FF) ^
67 		       (handle & 0x3FF);
68 	else if (HTSIZE == 512)
69 		return (handle >> 27) ^
70 		       ((handle >> 18) & 0x1FF) ^
71 		       ((handle >> 9) & 0x1FF) ^
72 		       (handle & 0x1FF);
73 	else if (HTSIZE == 256) {
74 		u8 *t = (u8 *) &handle;
75 		return t[0] ^ t[1] ^ t[2] ^ t[3];
76 	} else
77 		return handle & (HTSIZE - 1);
78 }
79 
80 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
81 			  struct tcf_result *res)
82 {
83 	struct fw_head *head = (struct fw_head *)tp->root;
84 	struct fw_filter *f;
85 	int r;
86 	u32 id = skb->mark;
87 
88 	if (head != NULL) {
89 		id &= head->mask;
90 		for (f = head->ht[fw_hash(id)]; f; f = f->next) {
91 			if (f->id == id) {
92 				*res = f->res;
93 #ifdef CONFIG_NET_CLS_IND
94 				if (!tcf_match_indev(skb, f->indev))
95 					continue;
96 #endif /* CONFIG_NET_CLS_IND */
97 				r = tcf_exts_exec(skb, &f->exts, res);
98 				if (r < 0)
99 					continue;
100 
101 				return r;
102 			}
103 		}
104 	} else {
105 		/* old method */
106 		if (id && (TC_H_MAJ(id) == 0 ||
107 			   !(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 void fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
142 {
143 	tcf_unbind_filter(tp, &f->res);
144 	tcf_exts_destroy(tp, &f->exts);
145 	kfree(f);
146 }
147 
148 static void fw_destroy(struct tcf_proto *tp)
149 {
150 	struct fw_head *head = tp->root;
151 	struct fw_filter *f;
152 	int h;
153 
154 	if (head == NULL)
155 		return;
156 
157 	for (h = 0; h < HTSIZE; h++) {
158 		while ((f = head->ht[h]) != NULL) {
159 			head->ht[h] = f->next;
160 			fw_delete_filter(tp, f);
161 		}
162 	}
163 	kfree(head);
164 }
165 
166 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
167 {
168 	struct fw_head *head = (struct fw_head *)tp->root;
169 	struct fw_filter *f = (struct fw_filter *)arg;
170 	struct fw_filter **fp;
171 
172 	if (head == NULL || f == NULL)
173 		goto out;
174 
175 	for (fp = &head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
176 		if (*fp == f) {
177 			tcf_tree_lock(tp);
178 			*fp = f->next;
179 			tcf_tree_unlock(tp);
180 			fw_delete_filter(tp, f);
181 			return 0;
182 		}
183 	}
184 out:
185 	return -EINVAL;
186 }
187 
188 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
189 	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
190 	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
191 	[TCA_FW_MASK]		= { .type = NLA_U32 },
192 };
193 
194 static int
195 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
196 	struct nlattr **tb, struct nlattr **tca, unsigned long base)
197 {
198 	struct fw_head *head = (struct fw_head *)tp->root;
199 	struct tcf_exts e;
200 	u32 mask;
201 	int err;
202 
203 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
204 	if (err < 0)
205 		return err;
206 
207 	err = -EINVAL;
208 	if (tb[TCA_FW_CLASSID]) {
209 		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
210 		tcf_bind_filter(tp, &f->res, base);
211 	}
212 
213 #ifdef CONFIG_NET_CLS_IND
214 	if (tb[TCA_FW_INDEV]) {
215 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
216 		if (err < 0)
217 			goto errout;
218 	}
219 #endif /* CONFIG_NET_CLS_IND */
220 
221 	if (tb[TCA_FW_MASK]) {
222 		mask = nla_get_u32(tb[TCA_FW_MASK]);
223 		if (mask != head->mask)
224 			goto errout;
225 	} else if (head->mask != 0xFFFFFFFF)
226 		goto errout;
227 
228 	tcf_exts_change(tp, &f->exts, &e);
229 
230 	return 0;
231 errout:
232 	tcf_exts_destroy(tp, &e);
233 	return err;
234 }
235 
236 static int fw_change(struct tcf_proto *tp, unsigned long base,
237 		     u32 handle,
238 		     struct nlattr **tca,
239 		     unsigned long *arg)
240 {
241 	struct fw_head *head = (struct fw_head *)tp->root;
242 	struct fw_filter *f = (struct fw_filter *) *arg;
243 	struct nlattr *opt = tca[TCA_OPTIONS];
244 	struct nlattr *tb[TCA_FW_MAX + 1];
245 	int err;
246 
247 	if (!opt)
248 		return handle ? -EINVAL : 0;
249 
250 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
251 	if (err < 0)
252 		return err;
253 
254 	if (f != NULL) {
255 		if (f->id != handle && handle)
256 			return -EINVAL;
257 		return fw_change_attrs(tp, f, tb, tca, base);
258 	}
259 
260 	if (!handle)
261 		return -EINVAL;
262 
263 	if (head == NULL) {
264 		u32 mask = 0xFFFFFFFF;
265 		if (tb[TCA_FW_MASK])
266 			mask = nla_get_u32(tb[TCA_FW_MASK]);
267 
268 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
269 		if (head == NULL)
270 			return -ENOBUFS;
271 		head->mask = mask;
272 
273 		tcf_tree_lock(tp);
274 		tp->root = head;
275 		tcf_tree_unlock(tp);
276 	}
277 
278 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
279 	if (f == NULL)
280 		return -ENOBUFS;
281 
282 	f->id = handle;
283 
284 	err = fw_change_attrs(tp, f, tb, tca, base);
285 	if (err < 0)
286 		goto errout;
287 
288 	f->next = head->ht[fw_hash(handle)];
289 	tcf_tree_lock(tp);
290 	head->ht[fw_hash(handle)] = f;
291 	tcf_tree_unlock(tp);
292 
293 	*arg = (unsigned long)f;
294 	return 0;
295 
296 errout:
297 	kfree(f);
298 	return err;
299 }
300 
301 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
302 {
303 	struct fw_head *head = (struct fw_head *)tp->root;
304 	int h;
305 
306 	if (head == NULL)
307 		arg->stop = 1;
308 
309 	if (arg->stop)
310 		return;
311 
312 	for (h = 0; h < HTSIZE; h++) {
313 		struct fw_filter *f;
314 
315 		for (f = head->ht[h]; f; f = f->next) {
316 			if (arg->count < arg->skip) {
317 				arg->count++;
318 				continue;
319 			}
320 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
321 				arg->stop = 1;
322 				return;
323 			}
324 			arg->count++;
325 		}
326 	}
327 }
328 
329 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
330 		   struct sk_buff *skb, struct tcmsg *t)
331 {
332 	struct fw_head *head = (struct fw_head *)tp->root;
333 	struct fw_filter *f = (struct fw_filter *)fh;
334 	unsigned char *b = skb_tail_pointer(skb);
335 	struct nlattr *nest;
336 
337 	if (f == NULL)
338 		return skb->len;
339 
340 	t->tcm_handle = f->id;
341 
342 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
343 		return skb->len;
344 
345 	nest = nla_nest_start(skb, TCA_OPTIONS);
346 	if (nest == NULL)
347 		goto nla_put_failure;
348 
349 	if (f->res.classid &&
350 	    nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
351 		goto nla_put_failure;
352 #ifdef CONFIG_NET_CLS_IND
353 	if (strlen(f->indev) &&
354 	    nla_put_string(skb, TCA_FW_INDEV, f->indev))
355 		goto nla_put_failure;
356 #endif /* CONFIG_NET_CLS_IND */
357 	if (head->mask != 0xFFFFFFFF &&
358 	    nla_put_u32(skb, TCA_FW_MASK, head->mask))
359 		goto nla_put_failure;
360 
361 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
362 		goto nla_put_failure;
363 
364 	nla_nest_end(skb, nest);
365 
366 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
367 		goto nla_put_failure;
368 
369 	return skb->len;
370 
371 nla_put_failure:
372 	nlmsg_trim(skb, b);
373 	return -1;
374 }
375 
376 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
377 	.kind		=	"fw",
378 	.classify	=	fw_classify,
379 	.init		=	fw_init,
380 	.destroy	=	fw_destroy,
381 	.get		=	fw_get,
382 	.put		=	fw_put,
383 	.change		=	fw_change,
384 	.delete		=	fw_delete,
385 	.walk		=	fw_walk,
386 	.dump		=	fw_dump,
387 	.owner		=	THIS_MODULE,
388 };
389 
390 static int __init init_fw(void)
391 {
392 	return register_tcf_proto_ops(&cls_fw_ops);
393 }
394 
395 static void __exit exit_fw(void)
396 {
397 	unregister_tcf_proto_ops(&cls_fw_ops);
398 }
399 
400 module_init(init_fw)
401 module_exit(exit_fw)
402 MODULE_LICENSE("GPL");
403