xref: /linux/net/sched/cls_fw.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862) 
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/sched.h>
28 #include <linux/string.h>
29 #include <linux/mm.h>
30 #include <linux/socket.h>
31 #include <linux/sockios.h>
32 #include <linux/in.h>
33 #include <linux/errno.h>
34 #include <linux/interrupt.h>
35 #include <linux/if_ether.h>
36 #include <linux/inet.h>
37 #include <linux/netdevice.h>
38 #include <linux/etherdevice.h>
39 #include <linux/notifier.h>
40 #include <linux/netfilter.h>
41 #include <net/ip.h>
42 #include <net/route.h>
43 #include <linux/skbuff.h>
44 #include <net/sock.h>
45 #include <net/act_api.h>
46 #include <net/pkt_cls.h>
47 
48 #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
49 
50 struct fw_head
51 {
52 	struct fw_filter *ht[HTSIZE];
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 #ifdef CONFIG_NETFILTER
104 	u32 id = skb->nfmark;
105 #else
106 	u32 id = 0;
107 #endif
108 
109 	if (head != NULL) {
110 		for (f=head->ht[fw_hash(id)]; f; f=f->next) {
111 			if (f->id == id) {
112 				*res = f->res;
113 #ifdef CONFIG_NET_CLS_IND
114 				if (!tcf_match_indev(skb, f->indev))
115 					continue;
116 #endif /* CONFIG_NET_CLS_IND */
117 				r = tcf_exts_exec(skb, &f->exts, res);
118 				if (r < 0)
119 					continue;
120 
121 				return r;
122 			}
123 		}
124 	} else {
125 		/* old method */
126 		if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
127 			res->classid = id;
128 			res->class = 0;
129 			return 0;
130 		}
131 	}
132 
133 	return -1;
134 }
135 
136 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
137 {
138 	struct fw_head *head = (struct fw_head*)tp->root;
139 	struct fw_filter *f;
140 
141 	if (head == NULL)
142 		return 0;
143 
144 	for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
145 		if (f->id == handle)
146 			return (unsigned long)f;
147 	}
148 	return 0;
149 }
150 
151 static void fw_put(struct tcf_proto *tp, unsigned long f)
152 {
153 }
154 
155 static int fw_init(struct tcf_proto *tp)
156 {
157 	return 0;
158 }
159 
160 static inline void
161 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
162 {
163 	tcf_unbind_filter(tp, &f->res);
164 	tcf_exts_destroy(tp, &f->exts);
165 	kfree(f);
166 }
167 
168 static void fw_destroy(struct tcf_proto *tp)
169 {
170 	struct fw_head *head = (struct fw_head*)xchg(&tp->root, NULL);
171 	struct fw_filter *f;
172 	int h;
173 
174 	if (head == NULL)
175 		return;
176 
177 	for (h=0; h<HTSIZE; h++) {
178 		while ((f=head->ht[h]) != NULL) {
179 			head->ht[h] = f->next;
180 			fw_delete_filter(tp, f);
181 		}
182 	}
183 	kfree(head);
184 }
185 
186 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
187 {
188 	struct fw_head *head = (struct fw_head*)tp->root;
189 	struct fw_filter *f = (struct fw_filter*)arg;
190 	struct fw_filter **fp;
191 
192 	if (head == NULL || f == NULL)
193 		goto out;
194 
195 	for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
196 		if (*fp == f) {
197 			tcf_tree_lock(tp);
198 			*fp = f->next;
199 			tcf_tree_unlock(tp);
200 			fw_delete_filter(tp, f);
201 			return 0;
202 		}
203 	}
204 out:
205 	return -EINVAL;
206 }
207 
208 static int
209 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
210 	struct rtattr **tb, struct rtattr **tca, unsigned long base)
211 {
212 	struct tcf_exts e;
213 	int err;
214 
215 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE-1], &e, &fw_ext_map);
216 	if (err < 0)
217 		return err;
218 
219 	err = -EINVAL;
220 	if (tb[TCA_FW_CLASSID-1]) {
221 		if (RTA_PAYLOAD(tb[TCA_FW_CLASSID-1]) != sizeof(u32))
222 			goto errout;
223 		f->res.classid = *(u32*)RTA_DATA(tb[TCA_FW_CLASSID-1]);
224 		tcf_bind_filter(tp, &f->res, base);
225 	}
226 
227 #ifdef CONFIG_NET_CLS_IND
228 	if (tb[TCA_FW_INDEV-1]) {
229 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV-1]);
230 		if (err < 0)
231 			goto errout;
232 	}
233 #endif /* CONFIG_NET_CLS_IND */
234 
235 	tcf_exts_change(tp, &f->exts, &e);
236 
237 	return 0;
238 errout:
239 	tcf_exts_destroy(tp, &e);
240 	return err;
241 }
242 
243 static int fw_change(struct tcf_proto *tp, unsigned long base,
244 		     u32 handle,
245 		     struct rtattr **tca,
246 		     unsigned long *arg)
247 {
248 	struct fw_head *head = (struct fw_head*)tp->root;
249 	struct fw_filter *f = (struct fw_filter *) *arg;
250 	struct rtattr *opt = tca[TCA_OPTIONS-1];
251 	struct rtattr *tb[TCA_FW_MAX];
252 	int err;
253 
254 	if (!opt)
255 		return handle ? -EINVAL : 0;
256 
257 	if (rtattr_parse_nested(tb, TCA_FW_MAX, opt) < 0)
258 		return -EINVAL;
259 
260 	if (f != NULL) {
261 		if (f->id != handle && handle)
262 			return -EINVAL;
263 		return fw_change_attrs(tp, f, tb, tca, base);
264 	}
265 
266 	if (!handle)
267 		return -EINVAL;
268 
269 	if (head == NULL) {
270 		head = kmalloc(sizeof(struct fw_head), GFP_KERNEL);
271 		if (head == NULL)
272 			return -ENOBUFS;
273 		memset(head, 0, sizeof(*head));
274 
275 		tcf_tree_lock(tp);
276 		tp->root = head;
277 		tcf_tree_unlock(tp);
278 	}
279 
280 	f = kmalloc(sizeof(struct fw_filter), GFP_KERNEL);
281 	if (f == NULL)
282 		return -ENOBUFS;
283 	memset(f, 0, sizeof(*f));
284 
285 	f->id = handle;
286 
287 	err = fw_change_attrs(tp, f, tb, tca, base);
288 	if (err < 0)
289 		goto errout;
290 
291 	f->next = head->ht[fw_hash(handle)];
292 	tcf_tree_lock(tp);
293 	head->ht[fw_hash(handle)] = f;
294 	tcf_tree_unlock(tp);
295 
296 	*arg = (unsigned long)f;
297 	return 0;
298 
299 errout:
300 	kfree(f);
301 	return err;
302 }
303 
304 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
305 {
306 	struct fw_head *head = (struct fw_head*)tp->root;
307 	int h;
308 
309 	if (head == NULL)
310 		arg->stop = 1;
311 
312 	if (arg->stop)
313 		return;
314 
315 	for (h = 0; h < HTSIZE; h++) {
316 		struct fw_filter *f;
317 
318 		for (f = head->ht[h]; f; f = f->next) {
319 			if (arg->count < arg->skip) {
320 				arg->count++;
321 				continue;
322 			}
323 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
324 				arg->stop = 1;
325 				return;
326 			}
327 			arg->count++;
328 		}
329 	}
330 }
331 
332 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
333 		   struct sk_buff *skb, struct tcmsg *t)
334 {
335 	struct fw_filter *f = (struct fw_filter*)fh;
336 	unsigned char	 *b = skb->tail;
337 	struct rtattr *rta;
338 
339 	if (f == NULL)
340 		return skb->len;
341 
342 	t->tcm_handle = f->id;
343 
344 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
345 		return skb->len;
346 
347 	rta = (struct rtattr*)b;
348 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
349 
350 	if (f->res.classid)
351 		RTA_PUT(skb, TCA_FW_CLASSID, 4, &f->res.classid);
352 #ifdef CONFIG_NET_CLS_IND
353 	if (strlen(f->indev))
354 		RTA_PUT(skb, TCA_FW_INDEV, IFNAMSIZ, f->indev);
355 #endif /* CONFIG_NET_CLS_IND */
356 
357 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
358 		goto rtattr_failure;
359 
360 	rta->rta_len = skb->tail - b;
361 
362 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
363 		goto rtattr_failure;
364 
365 	return skb->len;
366 
367 rtattr_failure:
368 	skb_trim(skb, b - skb->data);
369 	return -1;
370 }
371 
372 static struct tcf_proto_ops cls_fw_ops = {
373 	.next		=	NULL,
374 	.kind		=	"fw",
375 	.classify	=	fw_classify,
376 	.init		=	fw_init,
377 	.destroy	=	fw_destroy,
378 	.get		=	fw_get,
379 	.put		=	fw_put,
380 	.change		=	fw_change,
381 	.delete		=	fw_delete,
382 	.walk		=	fw_walk,
383 	.dump		=	fw_dump,
384 	.owner		=	THIS_MODULE,
385 };
386 
387 static int __init init_fw(void)
388 {
389 	return register_tcf_proto_ops(&cls_fw_ops);
390 }
391 
392 static void __exit exit_fw(void)
393 {
394 	unregister_tcf_proto_ops(&cls_fw_ops);
395 }
396 
397 module_init(init_fw)
398 module_exit(exit_fw)
399 MODULE_LICENSE("GPL");
400