xref: /linux/net/sched/cls_fw.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab) 
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/config.h>
22 #include <linux/module.h>
23 #include <asm/uaccess.h>
24 #include <asm/system.h>
25 #include <linux/bitops.h>
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/string.h>
30 #include <linux/mm.h>
31 #include <linux/socket.h>
32 #include <linux/sockios.h>
33 #include <linux/in.h>
34 #include <linux/errno.h>
35 #include <linux/interrupt.h>
36 #include <linux/if_ether.h>
37 #include <linux/inet.h>
38 #include <linux/netdevice.h>
39 #include <linux/etherdevice.h>
40 #include <linux/notifier.h>
41 #include <linux/netfilter.h>
42 #include <net/ip.h>
43 #include <net/route.h>
44 #include <linux/skbuff.h>
45 #include <net/sock.h>
46 #include <net/act_api.h>
47 #include <net/pkt_cls.h>
48 
49 #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
50 
51 struct fw_head
52 {
53 	struct fw_filter *ht[HTSIZE];
54 };
55 
56 struct fw_filter
57 {
58 	struct fw_filter	*next;
59 	u32			id;
60 	struct tcf_result	res;
61 #ifdef CONFIG_NET_CLS_IND
62 	char			indev[IFNAMSIZ];
63 #endif /* CONFIG_NET_CLS_IND */
64 	struct tcf_exts		exts;
65 };
66 
67 static struct tcf_ext_map fw_ext_map = {
68 	.action = TCA_FW_ACT,
69 	.police = TCA_FW_POLICE
70 };
71 
72 static __inline__ int fw_hash(u32 handle)
73 {
74 	if (HTSIZE == 4096)
75 		return ((handle >> 24) & 0xFFF) ^
76 		       ((handle >> 12) & 0xFFF) ^
77 		       (handle & 0xFFF);
78 	else if (HTSIZE == 2048)
79 		return ((handle >> 22) & 0x7FF) ^
80 		       ((handle >> 11) & 0x7FF) ^
81 		       (handle & 0x7FF);
82 	else if (HTSIZE == 1024)
83 		return ((handle >> 20) & 0x3FF) ^
84 		       ((handle >> 10) & 0x3FF) ^
85 		       (handle & 0x3FF);
86 	else if (HTSIZE == 512)
87 		return (handle >> 27) ^
88 		       ((handle >> 18) & 0x1FF) ^
89 		       ((handle >> 9) & 0x1FF) ^
90 		       (handle & 0x1FF);
91 	else if (HTSIZE == 256) {
92 		u8 *t = (u8 *) &handle;
93 		return t[0] ^ t[1] ^ t[2] ^ t[3];
94 	} else
95 		return handle & (HTSIZE - 1);
96 }
97 
98 static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
99 			  struct tcf_result *res)
100 {
101 	struct fw_head *head = (struct fw_head*)tp->root;
102 	struct fw_filter *f;
103 	int r;
104 #ifdef CONFIG_NETFILTER
105 	u32 id = skb->nfmark;
106 #else
107 	u32 id = 0;
108 #endif
109 
110 	if (head != NULL) {
111 		for (f=head->ht[fw_hash(id)]; f; f=f->next) {
112 			if (f->id == id) {
113 				*res = f->res;
114 #ifdef CONFIG_NET_CLS_IND
115 				if (!tcf_match_indev(skb, f->indev))
116 					continue;
117 #endif /* CONFIG_NET_CLS_IND */
118 				r = tcf_exts_exec(skb, &f->exts, res);
119 				if (r < 0)
120 					continue;
121 
122 				return r;
123 			}
124 		}
125 	} else {
126 		/* old method */
127 		if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
128 			res->classid = id;
129 			res->class = 0;
130 			return 0;
131 		}
132 	}
133 
134 	return -1;
135 }
136 
137 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
138 {
139 	struct fw_head *head = (struct fw_head*)tp->root;
140 	struct fw_filter *f;
141 
142 	if (head == NULL)
143 		return 0;
144 
145 	for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
146 		if (f->id == handle)
147 			return (unsigned long)f;
148 	}
149 	return 0;
150 }
151 
152 static void fw_put(struct tcf_proto *tp, unsigned long f)
153 {
154 }
155 
156 static int fw_init(struct tcf_proto *tp)
157 {
158 	return 0;
159 }
160 
161 static inline void
162 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
163 {
164 	tcf_unbind_filter(tp, &f->res);
165 	tcf_exts_destroy(tp, &f->exts);
166 	kfree(f);
167 }
168 
169 static void fw_destroy(struct tcf_proto *tp)
170 {
171 	struct fw_head *head = (struct fw_head*)xchg(&tp->root, NULL);
172 	struct fw_filter *f;
173 	int h;
174 
175 	if (head == NULL)
176 		return;
177 
178 	for (h=0; h<HTSIZE; h++) {
179 		while ((f=head->ht[h]) != NULL) {
180 			head->ht[h] = f->next;
181 			fw_delete_filter(tp, f);
182 		}
183 	}
184 	kfree(head);
185 }
186 
187 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
188 {
189 	struct fw_head *head = (struct fw_head*)tp->root;
190 	struct fw_filter *f = (struct fw_filter*)arg;
191 	struct fw_filter **fp;
192 
193 	if (head == NULL || f == NULL)
194 		goto out;
195 
196 	for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
197 		if (*fp == f) {
198 			tcf_tree_lock(tp);
199 			*fp = f->next;
200 			tcf_tree_unlock(tp);
201 			fw_delete_filter(tp, f);
202 			return 0;
203 		}
204 	}
205 out:
206 	return -EINVAL;
207 }
208 
209 static int
210 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
211 	struct rtattr **tb, struct rtattr **tca, unsigned long base)
212 {
213 	struct tcf_exts e;
214 	int err;
215 
216 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE-1], &e, &fw_ext_map);
217 	if (err < 0)
218 		return err;
219 
220 	err = -EINVAL;
221 	if (tb[TCA_FW_CLASSID-1]) {
222 		if (RTA_PAYLOAD(tb[TCA_FW_CLASSID-1]) != sizeof(u32))
223 			goto errout;
224 		f->res.classid = *(u32*)RTA_DATA(tb[TCA_FW_CLASSID-1]);
225 		tcf_bind_filter(tp, &f->res, base);
226 	}
227 
228 #ifdef CONFIG_NET_CLS_IND
229 	if (tb[TCA_FW_INDEV-1]) {
230 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV-1]);
231 		if (err < 0)
232 			goto errout;
233 	}
234 #endif /* CONFIG_NET_CLS_IND */
235 
236 	tcf_exts_change(tp, &f->exts, &e);
237 
238 	return 0;
239 errout:
240 	tcf_exts_destroy(tp, &e);
241 	return err;
242 }
243 
244 static int fw_change(struct tcf_proto *tp, unsigned long base,
245 		     u32 handle,
246 		     struct rtattr **tca,
247 		     unsigned long *arg)
248 {
249 	struct fw_head *head = (struct fw_head*)tp->root;
250 	struct fw_filter *f = (struct fw_filter *) *arg;
251 	struct rtattr *opt = tca[TCA_OPTIONS-1];
252 	struct rtattr *tb[TCA_FW_MAX];
253 	int err;
254 
255 	if (!opt)
256 		return handle ? -EINVAL : 0;
257 
258 	if (rtattr_parse_nested(tb, TCA_FW_MAX, opt) < 0)
259 		return -EINVAL;
260 
261 	if (f != NULL) {
262 		if (f->id != handle && handle)
263 			return -EINVAL;
264 		return fw_change_attrs(tp, f, tb, tca, base);
265 	}
266 
267 	if (!handle)
268 		return -EINVAL;
269 
270 	if (head == NULL) {
271 		head = kmalloc(sizeof(struct fw_head), GFP_KERNEL);
272 		if (head == NULL)
273 			return -ENOBUFS;
274 		memset(head, 0, sizeof(*head));
275 
276 		tcf_tree_lock(tp);
277 		tp->root = head;
278 		tcf_tree_unlock(tp);
279 	}
280 
281 	f = kmalloc(sizeof(struct fw_filter), GFP_KERNEL);
282 	if (f == NULL)
283 		return -ENOBUFS;
284 	memset(f, 0, sizeof(*f));
285 
286 	f->id = handle;
287 
288 	err = fw_change_attrs(tp, f, tb, tca, base);
289 	if (err < 0)
290 		goto errout;
291 
292 	f->next = head->ht[fw_hash(handle)];
293 	tcf_tree_lock(tp);
294 	head->ht[fw_hash(handle)] = f;
295 	tcf_tree_unlock(tp);
296 
297 	*arg = (unsigned long)f;
298 	return 0;
299 
300 errout:
301 	if (f)
302 		kfree(f);
303 	return err;
304 }
305 
306 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
307 {
308 	struct fw_head *head = (struct fw_head*)tp->root;
309 	int h;
310 
311 	if (head == NULL)
312 		arg->stop = 1;
313 
314 	if (arg->stop)
315 		return;
316 
317 	for (h = 0; h < HTSIZE; h++) {
318 		struct fw_filter *f;
319 
320 		for (f = head->ht[h]; f; f = f->next) {
321 			if (arg->count < arg->skip) {
322 				arg->count++;
323 				continue;
324 			}
325 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
326 				arg->stop = 1;
327 				return;
328 			}
329 			arg->count++;
330 		}
331 	}
332 }
333 
334 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
335 		   struct sk_buff *skb, struct tcmsg *t)
336 {
337 	struct fw_filter *f = (struct fw_filter*)fh;
338 	unsigned char	 *b = skb->tail;
339 	struct rtattr *rta;
340 
341 	if (f == NULL)
342 		return skb->len;
343 
344 	t->tcm_handle = f->id;
345 
346 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
347 		return skb->len;
348 
349 	rta = (struct rtattr*)b;
350 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
351 
352 	if (f->res.classid)
353 		RTA_PUT(skb, TCA_FW_CLASSID, 4, &f->res.classid);
354 #ifdef CONFIG_NET_CLS_IND
355 	if (strlen(f->indev))
356 		RTA_PUT(skb, TCA_FW_INDEV, IFNAMSIZ, f->indev);
357 #endif /* CONFIG_NET_CLS_IND */
358 
359 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
360 		goto rtattr_failure;
361 
362 	rta->rta_len = skb->tail - b;
363 
364 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
365 		goto rtattr_failure;
366 
367 	return skb->len;
368 
369 rtattr_failure:
370 	skb_trim(skb, b - skb->data);
371 	return -1;
372 }
373 
374 static struct tcf_proto_ops cls_fw_ops = {
375 	.next		=	NULL,
376 	.kind		=	"fw",
377 	.classify	=	fw_classify,
378 	.init		=	fw_init,
379 	.destroy	=	fw_destroy,
380 	.get		=	fw_get,
381 	.put		=	fw_put,
382 	.change		=	fw_change,
383 	.delete		=	fw_delete,
384 	.walk		=	fw_walk,
385 	.dump		=	fw_dump,
386 	.owner		=	THIS_MODULE,
387 };
388 
389 static int __init init_fw(void)
390 {
391 	return register_tcf_proto_ops(&cls_fw_ops);
392 }
393 
394 static void __exit exit_fw(void)
395 {
396 	unregister_tcf_proto_ops(&cls_fw_ops);
397 }
398 
399 module_init(init_fw)
400 module_exit(exit_fw)
401 MODULE_LICENSE("GPL");
402