xref: /openbmc/linux/net/sched/cls_fw.c (revision 06ed5c2b) 
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 256
33 
34 struct fw_head {
35 	u32			mask;
36 	struct fw_filter	*ht[HTSIZE];
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 u32 fw_hash(u32 handle)
50 {
51 	handle ^= (handle >> 16);
52 	handle ^= (handle >> 8);
53 	return handle % HTSIZE;
54 }
55 
56 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
57 			  struct tcf_result *res)
58 {
59 	struct fw_head *head = tp->root;
60 	struct fw_filter *f;
61 	int r;
62 	u32 id = skb->mark;
63 
64 	if (head != NULL) {
65 		id &= head->mask;
66 		for (f = head->ht[fw_hash(id)]; f; f = f->next) {
67 			if (f->id == id) {
68 				*res = f->res;
69 #ifdef CONFIG_NET_CLS_IND
70 				if (!tcf_match_indev(skb, f->ifindex))
71 					continue;
72 #endif /* CONFIG_NET_CLS_IND */
73 				r = tcf_exts_exec(skb, &f->exts, res);
74 				if (r < 0)
75 					continue;
76 
77 				return r;
78 			}
79 		}
80 	} else {
81 		/* old method */
82 		if (id && (TC_H_MAJ(id) == 0 ||
83 			   !(TC_H_MAJ(id ^ tp->q->handle)))) {
84 			res->classid = id;
85 			res->class = 0;
86 			return 0;
87 		}
88 	}
89 
90 	return -1;
91 }
92 
93 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
94 {
95 	struct fw_head *head = tp->root;
96 	struct fw_filter *f;
97 
98 	if (head == NULL)
99 		return 0;
100 
101 	for (f = head->ht[fw_hash(handle)]; f; f = f->next) {
102 		if (f->id == handle)
103 			return (unsigned long)f;
104 	}
105 	return 0;
106 }
107 
108 static void fw_put(struct tcf_proto *tp, unsigned long f)
109 {
110 }
111 
112 static int fw_init(struct tcf_proto *tp)
113 {
114 	return 0;
115 }
116 
117 static void fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
118 {
119 	tcf_unbind_filter(tp, &f->res);
120 	tcf_exts_destroy(tp, &f->exts);
121 	kfree(f);
122 }
123 
124 static void fw_destroy(struct tcf_proto *tp)
125 {
126 	struct fw_head *head = tp->root;
127 	struct fw_filter *f;
128 	int h;
129 
130 	if (head == NULL)
131 		return;
132 
133 	for (h = 0; h < HTSIZE; h++) {
134 		while ((f = head->ht[h]) != NULL) {
135 			head->ht[h] = f->next;
136 			fw_delete_filter(tp, f);
137 		}
138 	}
139 	kfree(head);
140 }
141 
142 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
143 {
144 	struct fw_head *head = tp->root;
145 	struct fw_filter *f = (struct fw_filter *)arg;
146 	struct fw_filter **fp;
147 
148 	if (head == NULL || f == NULL)
149 		goto out;
150 
151 	for (fp = &head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
152 		if (*fp == f) {
153 			tcf_tree_lock(tp);
154 			*fp = f->next;
155 			tcf_tree_unlock(tp);
156 			fw_delete_filter(tp, f);
157 			return 0;
158 		}
159 	}
160 out:
161 	return -EINVAL;
162 }
163 
164 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
165 	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
166 	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
167 	[TCA_FW_MASK]		= { .type = NLA_U32 },
168 };
169 
170 static int
171 fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
172 	struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
173 {
174 	struct fw_head *head = tp->root;
175 	struct tcf_exts e;
176 	u32 mask;
177 	int err;
178 
179 	tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
180 	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
181 	if (err < 0)
182 		return err;
183 
184 	if (tb[TCA_FW_CLASSID]) {
185 		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
186 		tcf_bind_filter(tp, &f->res, base);
187 	}
188 
189 #ifdef CONFIG_NET_CLS_IND
190 	if (tb[TCA_FW_INDEV]) {
191 		int ret;
192 		ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
193 		if (ret < 0) {
194 			err = ret;
195 			goto errout;
196 		}
197 		f->ifindex = ret;
198 	}
199 #endif /* CONFIG_NET_CLS_IND */
200 
201 	err = -EINVAL;
202 	if (tb[TCA_FW_MASK]) {
203 		mask = nla_get_u32(tb[TCA_FW_MASK]);
204 		if (mask != head->mask)
205 			goto errout;
206 	} else if (head->mask != 0xFFFFFFFF)
207 		goto errout;
208 
209 	tcf_exts_change(tp, &f->exts, &e);
210 
211 	return 0;
212 errout:
213 	tcf_exts_destroy(tp, &e);
214 	return err;
215 }
216 
217 static int fw_change(struct net *net, struct sk_buff *in_skb,
218 		     struct tcf_proto *tp, unsigned long base,
219 		     u32 handle,
220 		     struct nlattr **tca,
221 		     unsigned long *arg, bool ovr)
222 {
223 	struct fw_head *head = tp->root;
224 	struct fw_filter *f = (struct fw_filter *) *arg;
225 	struct nlattr *opt = tca[TCA_OPTIONS];
226 	struct nlattr *tb[TCA_FW_MAX + 1];
227 	int err;
228 
229 	if (!opt)
230 		return handle ? -EINVAL : 0;
231 
232 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
233 	if (err < 0)
234 		return err;
235 
236 	if (f != NULL) {
237 		if (f->id != handle && handle)
238 			return -EINVAL;
239 		return fw_change_attrs(net, tp, f, tb, tca, base, ovr);
240 	}
241 
242 	if (!handle)
243 		return -EINVAL;
244 
245 	if (head == NULL) {
246 		u32 mask = 0xFFFFFFFF;
247 		if (tb[TCA_FW_MASK])
248 			mask = nla_get_u32(tb[TCA_FW_MASK]);
249 
250 		head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
251 		if (head == NULL)
252 			return -ENOBUFS;
253 		head->mask = mask;
254 
255 		tcf_tree_lock(tp);
256 		tp->root = head;
257 		tcf_tree_unlock(tp);
258 	}
259 
260 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
261 	if (f == NULL)
262 		return -ENOBUFS;
263 
264 	tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
265 	f->id = handle;
266 
267 	err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
268 	if (err < 0)
269 		goto errout;
270 
271 	f->next = head->ht[fw_hash(handle)];
272 	tcf_tree_lock(tp);
273 	head->ht[fw_hash(handle)] = f;
274 	tcf_tree_unlock(tp);
275 
276 	*arg = (unsigned long)f;
277 	return 0;
278 
279 errout:
280 	kfree(f);
281 	return err;
282 }
283 
284 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
285 {
286 	struct fw_head *head = tp->root;
287 	int h;
288 
289 	if (head == NULL)
290 		arg->stop = 1;
291 
292 	if (arg->stop)
293 		return;
294 
295 	for (h = 0; h < HTSIZE; h++) {
296 		struct fw_filter *f;
297 
298 		for (f = head->ht[h]; f; f = f->next) {
299 			if (arg->count < arg->skip) {
300 				arg->count++;
301 				continue;
302 			}
303 			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
304 				arg->stop = 1;
305 				return;
306 			}
307 			arg->count++;
308 		}
309 	}
310 }
311 
312 static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
313 		   struct sk_buff *skb, struct tcmsg *t)
314 {
315 	struct fw_head *head = tp->root;
316 	struct fw_filter *f = (struct fw_filter *)fh;
317 	unsigned char *b = skb_tail_pointer(skb);
318 	struct nlattr *nest;
319 
320 	if (f == NULL)
321 		return skb->len;
322 
323 	t->tcm_handle = f->id;
324 
325 	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
326 		return skb->len;
327 
328 	nest = nla_nest_start(skb, TCA_OPTIONS);
329 	if (nest == NULL)
330 		goto nla_put_failure;
331 
332 	if (f->res.classid &&
333 	    nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
334 		goto nla_put_failure;
335 #ifdef CONFIG_NET_CLS_IND
336 	if (f->ifindex) {
337 		struct net_device *dev;
338 		dev = __dev_get_by_index(net, f->ifindex);
339 		if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
340 			goto nla_put_failure;
341 	}
342 #endif /* CONFIG_NET_CLS_IND */
343 	if (head->mask != 0xFFFFFFFF &&
344 	    nla_put_u32(skb, TCA_FW_MASK, head->mask))
345 		goto nla_put_failure;
346 
347 	if (tcf_exts_dump(skb, &f->exts) < 0)
348 		goto nla_put_failure;
349 
350 	nla_nest_end(skb, nest);
351 
352 	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
353 		goto nla_put_failure;
354 
355 	return skb->len;
356 
357 nla_put_failure:
358 	nlmsg_trim(skb, b);
359 	return -1;
360 }
361 
362 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
363 	.kind		=	"fw",
364 	.classify	=	fw_classify,
365 	.init		=	fw_init,
366 	.destroy	=	fw_destroy,
367 	.get		=	fw_get,
368 	.put		=	fw_put,
369 	.change		=	fw_change,
370 	.delete		=	fw_delete,
371 	.walk		=	fw_walk,
372 	.dump		=	fw_dump,
373 	.owner		=	THIS_MODULE,
374 };
375 
376 static int __init init_fw(void)
377 {
378 	return register_tcf_proto_ops(&cls_fw_ops);
379 }
380 
381 static void __exit exit_fw(void)
382 {
383 	unregister_tcf_proto_ops(&cls_fw_ops);
384 }
385 
386 module_init(init_fw)
387 module_exit(exit_fw)
388 MODULE_LICENSE("GPL");
389