xref: /linux/net/sched/cls_fw.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6) 
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 <asm/uaccess.h>
23 #include <asm/system.h>
24 #include <linux/bitops.h>
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/mm.h>
29 #include <linux/socket.h>
30 #include <linux/sockios.h>
31 #include <linux/in.h>
32 #include <linux/errno.h>
33 #include <linux/interrupt.h>
34 #include <linux/if_ether.h>
35 #include <linux/inet.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/notifier.h>
39 #include <linux/netfilter.h>
40 #include <net/ip.h>
41 #include <net/route.h>
42 #include <linux/skbuff.h>
43 #include <net/sock.h>
44 #include <net/act_api.h>
45 #include <net/pkt_cls.h>
46 
47 #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
48 
49 struct fw_head
50 {
51 	struct fw_filter *ht[HTSIZE];
52 	u32 mask;
53 };
54 
55 struct fw_filter
56 {
57 	struct fw_filter	*next;
58 	u32			id;
59 	struct tcf_result	res;
60 #ifdef CONFIG_NET_CLS_IND
61 	char			indev[IFNAMSIZ];
62 #endif /* CONFIG_NET_CLS_IND */
63 	struct tcf_exts		exts;
64 };
65 
66 static struct tcf_ext_map fw_ext_map = {
67 	.action = TCA_FW_ACT,
68 	.police = TCA_FW_POLICE
69 };
70 
71 static __inline__ int fw_hash(u32 handle)
72 {
73 	if (HTSIZE == 4096)
74 		return ((handle >> 24) & 0xFFF) ^
75 		       ((handle >> 12) & 0xFFF) ^
76 		       (handle & 0xFFF);
77 	else if (HTSIZE == 2048)
78 		return ((handle >> 22) & 0x7FF) ^
79 		       ((handle >> 11) & 0x7FF) ^
80 		       (handle & 0x7FF);
81 	else if (HTSIZE == 1024)
82 		return ((handle >> 20) & 0x3FF) ^
83 		       ((handle >> 10) & 0x3FF) ^
84 		       (handle & 0x3FF);
85 	else if (HTSIZE == 512)
86 		return (handle >> 27) ^
87 		       ((handle >> 18) & 0x1FF) ^
88 		       ((handle >> 9) & 0x1FF) ^
89 		       (handle & 0x1FF);
90 	else if (HTSIZE == 256) {
91 		u8 *t = (u8 *) &handle;
92 		return t[0] ^ t[1] ^ t[2] ^ t[3];
93 	} else
94 		return handle & (HTSIZE - 1);
95 }
96 
97 static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
98 			  struct tcf_result *res)
99 {
100 	struct fw_head *head = (struct fw_head*)tp->root;
101 	struct fw_filter *f;
102 	int r;
103 	u32 id = skb->mark;
104 
105 	if (head != NULL) {
106 		id &= head->mask;
107 		for (f=head->ht[fw_hash(id)]; f; f=f->next) {
108 			if (f->id == id) {
109 				*res = f->res;
110 #ifdef CONFIG_NET_CLS_IND
111 				if (!tcf_match_indev(skb, f->indev))
112 					continue;
113 #endif /* CONFIG_NET_CLS_IND */
114 				r = tcf_exts_exec(skb, &f->exts, res);
115 				if (r < 0)
116 					continue;
117 
118 				return r;
119 			}
120 		}
121 	} else {
122 		/* old method */
123 		if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
124 			res->classid = id;
125 			res->class = 0;
126 			return 0;
127 		}
128 	}
129 
130 	return -1;
131 }
132 
133 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
134 {
135 	struct fw_head *head = (struct fw_head*)tp->root;
136 	struct fw_filter *f;
137 
138 	if (head == NULL)
139 		return 0;
140 
141 	for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
142 		if (f->id == handle)
143 			return (unsigned long)f;
144 	}
145 	return 0;
146 }
147 
148 static void fw_put(struct tcf_proto *tp, unsigned long f)
149 {
150 }
151 
152 static int fw_init(struct tcf_proto *tp)
153 {
154 	return 0;
155 }
156 
157 static inline void
158 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
159 {
160 	tcf_unbind_filter(tp, &f->res);
161 	tcf_exts_destroy(tp, &f->exts);
162 	kfree(f);
163 }
164 
165 static void fw_destroy(struct tcf_proto *tp)
166 {
167 	struct fw_head *head = (struct fw_head*)xchg(&tp->root, NULL);
168 	struct fw_filter *f;
169 	int h;
170 
171 	if (head == NULL)
172 		return;
173 
174 	for (h=0; h<HTSIZE; h++) {
175 		while ((f=head->ht[h]) != NULL) {
176 			head->ht[h] = f->next;
177 			fw_delete_filter(tp, f);
178 		}
179 	}
180 	kfree(head);
181 }
182 
183 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
184 {
185 	struct fw_head *head = (struct fw_head*)tp->root;
186 	struct fw_filter *f = (struct fw_filter*)arg;
187 	struct fw_filter **fp;
188 
189 	if (head == NULL || f == NULL)
190 		goto out;
191 
192 	for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
193 		if (*fp == f) {
194 			tcf_tree_lock(tp);
195 			*fp = f->next;
196 			tcf_tree_unlock(tp);
197 			fw_delete_filter(tp, f);
198 			return 0;
199 		}
200 	}
201 out:
202 	return -EINVAL;
203 }
204 
205 static int
206 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
207 	struct rtattr **tb, struct rtattr **tca, unsigned long base)
208 {
209 	struct fw_head *head = (struct fw_head *)tp->root;
210 	struct tcf_exts e;
211 	u32 mask;
212 	int err;
213 
214 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE-1], &e, &fw_ext_map);
215 	if (err < 0)
216 		return err;
217 
218 	err = -EINVAL;
219 	if (tb[TCA_FW_CLASSID-1]) {
220 		if (RTA_PAYLOAD(tb[TCA_FW_CLASSID-1]) != sizeof(u32))
221 			goto errout;
222 		f->res.classid = *(u32*)RTA_DATA(tb[TCA_FW_CLASSID-1]);
223 		tcf_bind_filter(tp, &f->res, base);
224 	}
225 
226 #ifdef CONFIG_NET_CLS_IND
227 	if (tb[TCA_FW_INDEV-1]) {
228 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV-1]);
229 		if (err < 0)
230 			goto errout;
231 	}
232 #endif /* CONFIG_NET_CLS_IND */
233 
234 	if (tb[TCA_FW_MASK-1]) {
235 		if (RTA_PAYLOAD(tb[TCA_FW_MASK-1]) != sizeof(u32))
236 			goto errout;
237 		mask = *(u32*)RTA_DATA(tb[TCA_FW_MASK-1]);
238 		if (mask != head->mask)
239 			goto errout;
240 	} else if (head->mask != 0xFFFFFFFF)
241 		goto errout;
242 
243 	tcf_exts_change(tp, &f->exts, &e);
244 
245 	return 0;
246 errout:
247 	tcf_exts_destroy(tp, &e);
248 	return err;
249 }
250 
251 static int fw_change(struct tcf_proto *tp, unsigned long base,
252 		     u32 handle,
253 		     struct rtattr **tca,
254 		     unsigned long *arg)
255 {
256 	struct fw_head *head = (struct fw_head*)tp->root;
257 	struct fw_filter *f = (struct fw_filter *) *arg;
258 	struct rtattr *opt = tca[TCA_OPTIONS-1];
259 	struct rtattr *tb[TCA_FW_MAX];
260 	int err;
261 
262 	if (!opt)
263 		return handle ? -EINVAL : 0;
264 
265 	if (rtattr_parse_nested(tb, TCA_FW_MAX, opt) < 0)
266 		return -EINVAL;
267 
268 	if (f != NULL) {
269 		if (f->id != handle && handle)
270 			return -EINVAL;
271 		return fw_change_attrs(tp, f, tb, tca, base);
272 	}
273 
274 	if (!handle)
275 		return -EINVAL;
276 
277 	if (head == NULL) {
278 		u32 mask = 0xFFFFFFFF;
279 		if (tb[TCA_FW_MASK-1]) {
280 			if (RTA_PAYLOAD(tb[TCA_FW_MASK-1]) != sizeof(u32))
281 				return -EINVAL;
282 			mask = *(u32*)RTA_DATA(tb[TCA_FW_MASK-1]);
283 		}
284 
285 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
286 		if (head == NULL)
287 			return -ENOBUFS;
288 		head->mask = mask;
289 
290 		tcf_tree_lock(tp);
291 		tp->root = head;
292 		tcf_tree_unlock(tp);
293 	}
294 
295 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
296 	if (f == NULL)
297 		return -ENOBUFS;
298 
299 	f->id = handle;
300 
301 	err = fw_change_attrs(tp, f, tb, tca, base);
302 	if (err < 0)
303 		goto errout;
304 
305 	f->next = head->ht[fw_hash(handle)];
306 	tcf_tree_lock(tp);
307 	head->ht[fw_hash(handle)] = f;
308 	tcf_tree_unlock(tp);
309 
310 	*arg = (unsigned long)f;
311 	return 0;
312 
313 errout:
314 	kfree(f);
315 	return err;
316 }
317 
318 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
319 {
320 	struct fw_head *head = (struct fw_head*)tp->root;
321 	int h;
322 
323 	if (head == NULL)
324 		arg->stop = 1;
325 
326 	if (arg->stop)
327 		return;
328 
329 	for (h = 0; h < HTSIZE; h++) {
330 		struct fw_filter *f;
331 
332 		for (f = head->ht[h]; f; f = f->next) {
333 			if (arg->count < arg->skip) {
334 				arg->count++;
335 				continue;
336 			}
337 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
338 				arg->stop = 1;
339 				return;
340 			}
341 			arg->count++;
342 		}
343 	}
344 }
345 
346 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
347 		   struct sk_buff *skb, struct tcmsg *t)
348 {
349 	struct fw_head *head = (struct fw_head *)tp->root;
350 	struct fw_filter *f = (struct fw_filter*)fh;
351 	unsigned char	 *b = skb->tail;
352 	struct rtattr *rta;
353 
354 	if (f == NULL)
355 		return skb->len;
356 
357 	t->tcm_handle = f->id;
358 
359 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
360 		return skb->len;
361 
362 	rta = (struct rtattr*)b;
363 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
364 
365 	if (f->res.classid)
366 		RTA_PUT(skb, TCA_FW_CLASSID, 4, &f->res.classid);
367 #ifdef CONFIG_NET_CLS_IND
368 	if (strlen(f->indev))
369 		RTA_PUT(skb, TCA_FW_INDEV, IFNAMSIZ, f->indev);
370 #endif /* CONFIG_NET_CLS_IND */
371 	if (head->mask != 0xFFFFFFFF)
372 		RTA_PUT(skb, TCA_FW_MASK, 4, &head->mask);
373 
374 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
375 		goto rtattr_failure;
376 
377 	rta->rta_len = skb->tail - b;
378 
379 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
380 		goto rtattr_failure;
381 
382 	return skb->len;
383 
384 rtattr_failure:
385 	skb_trim(skb, b - skb->data);
386 	return -1;
387 }
388 
389 static struct tcf_proto_ops cls_fw_ops = {
390 	.next		=	NULL,
391 	.kind		=	"fw",
392 	.classify	=	fw_classify,
393 	.init		=	fw_init,
394 	.destroy	=	fw_destroy,
395 	.get		=	fw_get,
396 	.put		=	fw_put,
397 	.change		=	fw_change,
398 	.delete		=	fw_delete,
399 	.walk		=	fw_walk,
400 	.dump		=	fw_dump,
401 	.owner		=	THIS_MODULE,
402 };
403 
404 static int __init init_fw(void)
405 {
406 	return register_tcf_proto_ops(&cls_fw_ops);
407 }
408 
409 static void __exit exit_fw(void)
410 {
411 	unregister_tcf_proto_ops(&cls_fw_ops);
412 }
413 
414 module_init(init_fw)
415 module_exit(exit_fw)
416 MODULE_LICENSE("GPL");
417