xref: /openbmc/linux/net/sched/cls_fw.c (revision 4800cd83) 
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 {
36 	struct fw_filter *ht[HTSIZE];
37 	u32 mask;
38 };
39 
40 struct fw_filter
41 {
42 	struct fw_filter	*next;
43 	u32			id;
44 	struct tcf_result	res;
45 #ifdef CONFIG_NET_CLS_IND
46 	char			indev[IFNAMSIZ];
47 #endif /* CONFIG_NET_CLS_IND */
48 	struct tcf_exts		exts;
49 };
50 
51 static const struct tcf_ext_map fw_ext_map = {
52 	.action = TCA_FW_ACT,
53 	.police = TCA_FW_POLICE
54 };
55 
56 static __inline__ int fw_hash(u32 handle)
57 {
58 	if (HTSIZE == 4096)
59 		return ((handle >> 24) & 0xFFF) ^
60 		       ((handle >> 12) & 0xFFF) ^
61 		       (handle & 0xFFF);
62 	else if (HTSIZE == 2048)
63 		return ((handle >> 22) & 0x7FF) ^
64 		       ((handle >> 11) & 0x7FF) ^
65 		       (handle & 0x7FF);
66 	else if (HTSIZE == 1024)
67 		return ((handle >> 20) & 0x3FF) ^
68 		       ((handle >> 10) & 0x3FF) ^
69 		       (handle & 0x3FF);
70 	else if (HTSIZE == 512)
71 		return (handle >> 27) ^
72 		       ((handle >> 18) & 0x1FF) ^
73 		       ((handle >> 9) & 0x1FF) ^
74 		       (handle & 0x1FF);
75 	else if (HTSIZE == 256) {
76 		u8 *t = (u8 *) &handle;
77 		return t[0] ^ t[1] ^ t[2] ^ t[3];
78 	} else
79 		return handle & (HTSIZE - 1);
80 }
81 
82 static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
83 			  struct tcf_result *res)
84 {
85 	struct fw_head *head = (struct fw_head*)tp->root;
86 	struct fw_filter *f;
87 	int r;
88 	u32 id = skb->mark;
89 
90 	if (head != NULL) {
91 		id &= head->mask;
92 		for (f=head->ht[fw_hash(id)]; f; f=f->next) {
93 			if (f->id == id) {
94 				*res = f->res;
95 #ifdef CONFIG_NET_CLS_IND
96 				if (!tcf_match_indev(skb, f->indev))
97 					continue;
98 #endif /* CONFIG_NET_CLS_IND */
99 				r = tcf_exts_exec(skb, &f->exts, res);
100 				if (r < 0)
101 					continue;
102 
103 				return r;
104 			}
105 		}
106 	} else {
107 		/* old method */
108 		if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
109 			res->classid = id;
110 			res->class = 0;
111 			return 0;
112 		}
113 	}
114 
115 	return -1;
116 }
117 
118 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
119 {
120 	struct fw_head *head = (struct fw_head*)tp->root;
121 	struct fw_filter *f;
122 
123 	if (head == NULL)
124 		return 0;
125 
126 	for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
127 		if (f->id == handle)
128 			return (unsigned long)f;
129 	}
130 	return 0;
131 }
132 
133 static void fw_put(struct tcf_proto *tp, unsigned long f)
134 {
135 }
136 
137 static int fw_init(struct tcf_proto *tp)
138 {
139 	return 0;
140 }
141 
142 static inline void
143 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
144 {
145 	tcf_unbind_filter(tp, &f->res);
146 	tcf_exts_destroy(tp, &f->exts);
147 	kfree(f);
148 }
149 
150 static void fw_destroy(struct tcf_proto *tp)
151 {
152 	struct fw_head *head = tp->root;
153 	struct fw_filter *f;
154 	int h;
155 
156 	if (head == NULL)
157 		return;
158 
159 	for (h=0; h<HTSIZE; h++) {
160 		while ((f=head->ht[h]) != NULL) {
161 			head->ht[h] = f->next;
162 			fw_delete_filter(tp, f);
163 		}
164 	}
165 	kfree(head);
166 }
167 
168 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
169 {
170 	struct fw_head *head = (struct fw_head*)tp->root;
171 	struct fw_filter *f = (struct fw_filter*)arg;
172 	struct fw_filter **fp;
173 
174 	if (head == NULL || f == NULL)
175 		goto out;
176 
177 	for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
178 		if (*fp == f) {
179 			tcf_tree_lock(tp);
180 			*fp = f->next;
181 			tcf_tree_unlock(tp);
182 			fw_delete_filter(tp, f);
183 			return 0;
184 		}
185 	}
186 out:
187 	return -EINVAL;
188 }
189 
190 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
191 	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
192 	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
193 	[TCA_FW_MASK]		= { .type = NLA_U32 },
194 };
195 
196 static int
197 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
198 	struct nlattr **tb, struct nlattr **tca, unsigned long base)
199 {
200 	struct fw_head *head = (struct fw_head *)tp->root;
201 	struct tcf_exts e;
202 	u32 mask;
203 	int err;
204 
205 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
206 	if (err < 0)
207 		return err;
208 
209 	err = -EINVAL;
210 	if (tb[TCA_FW_CLASSID]) {
211 		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
212 		tcf_bind_filter(tp, &f->res, base);
213 	}
214 
215 #ifdef CONFIG_NET_CLS_IND
216 	if (tb[TCA_FW_INDEV]) {
217 		err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
218 		if (err < 0)
219 			goto errout;
220 	}
221 #endif /* CONFIG_NET_CLS_IND */
222 
223 	if (tb[TCA_FW_MASK]) {
224 		mask = nla_get_u32(tb[TCA_FW_MASK]);
225 		if (mask != head->mask)
226 			goto errout;
227 	} else if (head->mask != 0xFFFFFFFF)
228 		goto errout;
229 
230 	tcf_exts_change(tp, &f->exts, &e);
231 
232 	return 0;
233 errout:
234 	tcf_exts_destroy(tp, &e);
235 	return err;
236 }
237 
238 static int fw_change(struct tcf_proto *tp, unsigned long base,
239 		     u32 handle,
240 		     struct nlattr **tca,
241 		     unsigned long *arg)
242 {
243 	struct fw_head *head = (struct fw_head*)tp->root;
244 	struct fw_filter *f = (struct fw_filter *) *arg;
245 	struct nlattr *opt = tca[TCA_OPTIONS];
246 	struct nlattr *tb[TCA_FW_MAX + 1];
247 	int err;
248 
249 	if (!opt)
250 		return handle ? -EINVAL : 0;
251 
252 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
253 	if (err < 0)
254 		return err;
255 
256 	if (f != NULL) {
257 		if (f->id != handle && handle)
258 			return -EINVAL;
259 		return fw_change_attrs(tp, f, tb, tca, base);
260 	}
261 
262 	if (!handle)
263 		return -EINVAL;
264 
265 	if (head == NULL) {
266 		u32 mask = 0xFFFFFFFF;
267 		if (tb[TCA_FW_MASK])
268 			mask = nla_get_u32(tb[TCA_FW_MASK]);
269 
270 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
271 		if (head == NULL)
272 			return -ENOBUFS;
273 		head->mask = mask;
274 
275 		tcf_tree_lock(tp);
276 		tp->root = head;
277 		tcf_tree_unlock(tp);
278 	}
279 
280 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
281 	if (f == NULL)
282 		return -ENOBUFS;
283 
284 	f->id = handle;
285 
286 	err = fw_change_attrs(tp, f, tb, tca, base);
287 	if (err < 0)
288 		goto errout;
289 
290 	f->next = head->ht[fw_hash(handle)];
291 	tcf_tree_lock(tp);
292 	head->ht[fw_hash(handle)] = f;
293 	tcf_tree_unlock(tp);
294 
295 	*arg = (unsigned long)f;
296 	return 0;
297 
298 errout:
299 	kfree(f);
300 	return err;
301 }
302 
303 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
304 {
305 	struct fw_head *head = (struct fw_head*)tp->root;
306 	int h;
307 
308 	if (head == NULL)
309 		arg->stop = 1;
310 
311 	if (arg->stop)
312 		return;
313 
314 	for (h = 0; h < HTSIZE; h++) {
315 		struct fw_filter *f;
316 
317 		for (f = head->ht[h]; f; f = f->next) {
318 			if (arg->count < arg->skip) {
319 				arg->count++;
320 				continue;
321 			}
322 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
323 				arg->stop = 1;
324 				return;
325 			}
326 			arg->count++;
327 		}
328 	}
329 }
330 
331 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
332 		   struct sk_buff *skb, struct tcmsg *t)
333 {
334 	struct fw_head *head = (struct fw_head *)tp->root;
335 	struct fw_filter *f = (struct fw_filter*)fh;
336 	unsigned char *b = skb_tail_pointer(skb);
337 	struct nlattr *nest;
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 	nest = nla_nest_start(skb, TCA_OPTIONS);
348 	if (nest == NULL)
349 		goto nla_put_failure;
350 
351 	if (f->res.classid)
352 		NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
353 #ifdef CONFIG_NET_CLS_IND
354 	if (strlen(f->indev))
355 		NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
356 #endif /* CONFIG_NET_CLS_IND */
357 	if (head->mask != 0xFFFFFFFF)
358 		NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);
359 
360 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
361 		goto nla_put_failure;
362 
363 	nla_nest_end(skb, nest);
364 
365 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
366 		goto nla_put_failure;
367 
368 	return skb->len;
369 
370 nla_put_failure:
371 	nlmsg_trim(skb, b);
372 	return -1;
373 }
374 
375 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
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