xref: /openbmc/linux/net/sched/cls_fw.c (revision afc98d90) 
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 	int			ifindex;
45 #endif /* CONFIG_NET_CLS_IND */
46 	struct tcf_exts		exts;
47 };
48 
49 static inline int fw_hash(u32 handle)
50 {
51 	if (HTSIZE == 4096)
52 		return ((handle >> 24) & 0xFFF) ^
53 		       ((handle >> 12) & 0xFFF) ^
54 		       (handle & 0xFFF);
55 	else if (HTSIZE == 2048)
56 		return ((handle >> 22) & 0x7FF) ^
57 		       ((handle >> 11) & 0x7FF) ^
58 		       (handle & 0x7FF);
59 	else if (HTSIZE == 1024)
60 		return ((handle >> 20) & 0x3FF) ^
61 		       ((handle >> 10) & 0x3FF) ^
62 		       (handle & 0x3FF);
63 	else if (HTSIZE == 512)
64 		return (handle >> 27) ^
65 		       ((handle >> 18) & 0x1FF) ^
66 		       ((handle >> 9) & 0x1FF) ^
67 		       (handle & 0x1FF);
68 	else if (HTSIZE == 256) {
69 		u8 *t = (u8 *) &handle;
70 		return t[0] ^ t[1] ^ t[2] ^ t[3];
71 	} else
72 		return handle & (HTSIZE - 1);
73 }
74 
75 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
76 			  struct tcf_result *res)
77 {
78 	struct fw_head *head = tp->root;
79 	struct fw_filter *f;
80 	int r;
81 	u32 id = skb->mark;
82 
83 	if (head != NULL) {
84 		id &= head->mask;
85 		for (f = head->ht[fw_hash(id)]; f; f = f->next) {
86 			if (f->id == id) {
87 				*res = f->res;
88 #ifdef CONFIG_NET_CLS_IND
89 				if (!tcf_match_indev(skb, f->ifindex))
90 					continue;
91 #endif /* CONFIG_NET_CLS_IND */
92 				r = tcf_exts_exec(skb, &f->exts, res);
93 				if (r < 0)
94 					continue;
95 
96 				return r;
97 			}
98 		}
99 	} else {
100 		/* old method */
101 		if (id && (TC_H_MAJ(id) == 0 ||
102 			   !(TC_H_MAJ(id ^ tp->q->handle)))) {
103 			res->classid = id;
104 			res->class = 0;
105 			return 0;
106 		}
107 	}
108 
109 	return -1;
110 }
111 
112 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
113 {
114 	struct fw_head *head = tp->root;
115 	struct fw_filter *f;
116 
117 	if (head == NULL)
118 		return 0;
119 
120 	for (f = head->ht[fw_hash(handle)]; f; f = f->next) {
121 		if (f->id == handle)
122 			return (unsigned long)f;
123 	}
124 	return 0;
125 }
126 
127 static void fw_put(struct tcf_proto *tp, unsigned long f)
128 {
129 }
130 
131 static int fw_init(struct tcf_proto *tp)
132 {
133 	return 0;
134 }
135 
136 static void fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
137 {
138 	tcf_unbind_filter(tp, &f->res);
139 	tcf_exts_destroy(tp, &f->exts);
140 	kfree(f);
141 }
142 
143 static void fw_destroy(struct tcf_proto *tp)
144 {
145 	struct fw_head *head = tp->root;
146 	struct fw_filter *f;
147 	int h;
148 
149 	if (head == NULL)
150 		return;
151 
152 	for (h = 0; h < HTSIZE; h++) {
153 		while ((f = head->ht[h]) != NULL) {
154 			head->ht[h] = f->next;
155 			fw_delete_filter(tp, f);
156 		}
157 	}
158 	kfree(head);
159 }
160 
161 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
162 {
163 	struct fw_head *head = tp->root;
164 	struct fw_filter *f = (struct fw_filter *)arg;
165 	struct fw_filter **fp;
166 
167 	if (head == NULL || f == NULL)
168 		goto out;
169 
170 	for (fp = &head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
171 		if (*fp == f) {
172 			tcf_tree_lock(tp);
173 			*fp = f->next;
174 			tcf_tree_unlock(tp);
175 			fw_delete_filter(tp, f);
176 			return 0;
177 		}
178 	}
179 out:
180 	return -EINVAL;
181 }
182 
183 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
184 	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
185 	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
186 	[TCA_FW_MASK]		= { .type = NLA_U32 },
187 };
188 
189 static int
190 fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
191 	struct nlattr **tb, struct nlattr **tca, unsigned long base)
192 {
193 	struct fw_head *head = tp->root;
194 	struct tcf_exts e;
195 	u32 mask;
196 	int err;
197 
198 	tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
199 	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e);
200 	if (err < 0)
201 		return err;
202 
203 	if (tb[TCA_FW_CLASSID]) {
204 		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
205 		tcf_bind_filter(tp, &f->res, base);
206 	}
207 
208 #ifdef CONFIG_NET_CLS_IND
209 	if (tb[TCA_FW_INDEV]) {
210 		int ret;
211 		ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
212 		if (ret < 0) {
213 			err = ret;
214 			goto errout;
215 		}
216 		f->ifindex = ret;
217 	}
218 #endif /* CONFIG_NET_CLS_IND */
219 
220 	err = -EINVAL;
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 net *net, struct sk_buff *in_skb,
237 		     struct tcf_proto *tp, unsigned long base,
238 		     u32 handle,
239 		     struct nlattr **tca,
240 		     unsigned long *arg)
241 {
242 	struct fw_head *head = tp->root;
243 	struct fw_filter *f = (struct fw_filter *) *arg;
244 	struct nlattr *opt = tca[TCA_OPTIONS];
245 	struct nlattr *tb[TCA_FW_MAX + 1];
246 	int err;
247 
248 	if (!opt)
249 		return handle ? -EINVAL : 0;
250 
251 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
252 	if (err < 0)
253 		return err;
254 
255 	if (f != NULL) {
256 		if (f->id != handle && handle)
257 			return -EINVAL;
258 		return fw_change_attrs(net, tp, f, tb, tca, base);
259 	}
260 
261 	if (!handle)
262 		return -EINVAL;
263 
264 	if (head == NULL) {
265 		u32 mask = 0xFFFFFFFF;
266 		if (tb[TCA_FW_MASK])
267 			mask = nla_get_u32(tb[TCA_FW_MASK]);
268 
269 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
270 		if (head == NULL)
271 			return -ENOBUFS;
272 		head->mask = mask;
273 
274 		tcf_tree_lock(tp);
275 		tp->root = head;
276 		tcf_tree_unlock(tp);
277 	}
278 
279 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
280 	if (f == NULL)
281 		return -ENOBUFS;
282 
283 	tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
284 	f->id = handle;
285 
286 	err = fw_change_attrs(net, 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 = 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 net *net, struct tcf_proto *tp, unsigned long fh,
332 		   struct sk_buff *skb, struct tcmsg *t)
333 {
334 	struct fw_head *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 		goto nla_put_failure;
354 #ifdef CONFIG_NET_CLS_IND
355 	if (f->ifindex) {
356 		struct net_device *dev;
357 		dev = __dev_get_by_index(net, f->ifindex);
358 		if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
359 			goto nla_put_failure;
360 	}
361 #endif /* CONFIG_NET_CLS_IND */
362 	if (head->mask != 0xFFFFFFFF &&
363 	    nla_put_u32(skb, TCA_FW_MASK, head->mask))
364 		goto nla_put_failure;
365 
366 	if (tcf_exts_dump(skb, &f->exts) < 0)
367 		goto nla_put_failure;
368 
369 	nla_nest_end(skb, nest);
370 
371 	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
372 		goto nla_put_failure;
373 
374 	return skb->len;
375 
376 nla_put_failure:
377 	nlmsg_trim(skb, b);
378 	return -1;
379 }
380 
381 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
382 	.kind		=	"fw",
383 	.classify	=	fw_classify,
384 	.init		=	fw_init,
385 	.destroy	=	fw_destroy,
386 	.get		=	fw_get,
387 	.put		=	fw_put,
388 	.change		=	fw_change,
389 	.delete		=	fw_delete,
390 	.walk		=	fw_walk,
391 	.dump		=	fw_dump,
392 	.owner		=	THIS_MODULE,
393 };
394 
395 static int __init init_fw(void)
396 {
397 	return register_tcf_proto_ops(&cls_fw_ops);
398 }
399 
400 static void __exit exit_fw(void)
401 {
402 	unregister_tcf_proto_ops(&cls_fw_ops);
403 }
404 
405 module_init(init_fw)
406 module_exit(exit_fw)
407 MODULE_LICENSE("GPL");
408