Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
/*
 * net/sched/cls_fw.c	Classifier mapping ipchains' fwmark to traffic class.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
 *
 * JHS: We should remove the CONFIG_NET_CLS_IND from here
 * eventually when the meta match extension is made available
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>

#define HTSIZE 256

struct fw_head {
	u32			mask;
	struct fw_filter __rcu	*ht[HTSIZE];
	struct rcu_head		rcu;
};

struct fw_filter {
	struct fw_filter __rcu	*next;
	u32			id;
	struct tcf_result	res;
#ifdef CONFIG_NET_CLS_IND
	int			ifindex;
#endif /* CONFIG_NET_CLS_IND */
	struct tcf_exts		exts;
	struct tcf_proto	*tp;
	struct rcu_head		rcu;
};

static u32 fw_hash(u32 handle)
{
	handle ^= (handle >> 16);
	handle ^= (handle >> 8);
	return handle % HTSIZE;
}

static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
			  struct tcf_result *res)
{
	struct fw_head *head = rcu_dereference_bh(tp->root);
	struct fw_filter *f;
	int r;
	u32 id = skb->mark;

	if (head != NULL) {
		id &= head->mask;

		for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
		     f = rcu_dereference_bh(f->next)) {
			if (f->id == id) {
				*res = f->res;
#ifdef CONFIG_NET_CLS_IND
				if (!tcf_match_indev(skb, f->ifindex))
					continue;
#endif /* CONFIG_NET_CLS_IND */
				r = tcf_exts_exec(skb, &f->exts, res);
				if (r < 0)
					continue;

				return r;
			}
		}
	} else {
		/* Old method: classify the packet using its skb mark. */
		if (id && (TC_H_MAJ(id) == 0 ||
			   !(TC_H_MAJ(id ^ tp->q->handle)))) {
			res->classid = id;
			res->class = 0;
			return 0;
		}
	}

	return -1;
}

static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct fw_filter *f;

	if (head == NULL)
		return 0;

	f = rtnl_dereference(head->ht[fw_hash(handle)]);
	for (; f; f = rtnl_dereference(f->next)) {
		if (f->id == handle)
			return (unsigned long)f;
	}
	return 0;
}

static int fw_init(struct tcf_proto *tp)
{
	/* We don't allocate fw_head here, because in the old method
	 * we don't need it at all.
	 */
	return 0;
}

static void fw_delete_filter(struct rcu_head *head)
{
	struct fw_filter *f = container_of(head, struct fw_filter, rcu);

	tcf_exts_destroy(&f->exts);
	kfree(f);
}

static bool fw_destroy(struct tcf_proto *tp, bool force)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct fw_filter *f;
	int h;

	if (head == NULL)
		return true;

	if (!force) {
		for (h = 0; h < HTSIZE; h++)
			if (rcu_access_pointer(head->ht[h]))
				return false;
	}

	for (h = 0; h < HTSIZE; h++) {
		while ((f = rtnl_dereference(head->ht[h])) != NULL) {
			RCU_INIT_POINTER(head->ht[h],
					 rtnl_dereference(f->next));
			tcf_unbind_filter(tp, &f->res);
			call_rcu(&f->rcu, fw_delete_filter);
		}
	}
	RCU_INIT_POINTER(tp->root, NULL);
	kfree_rcu(head, rcu);
	return true;
}

static int fw_delete(struct tcf_proto *tp, unsigned long arg)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct fw_filter *f = (struct fw_filter *)arg;
	struct fw_filter __rcu **fp;
	struct fw_filter *pfp;

	if (head == NULL || f == NULL)
		goto out;

	fp = &head->ht[fw_hash(f->id)];

	for (pfp = rtnl_dereference(*fp); pfp;
	     fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
		if (pfp == f) {
			RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
			tcf_unbind_filter(tp, &f->res);
			call_rcu(&f->rcu, fw_delete_filter);
			return 0;
		}
	}
out:
	return -EINVAL;
}

static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
	[TCA_FW_MASK]		= { .type = NLA_U32 },
};

static int
fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
	struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct tcf_exts e;
	u32 mask;
	int err;

	tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
	if (err < 0)
		return err;

	if (tb[TCA_FW_CLASSID]) {
		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
		tcf_bind_filter(tp, &f->res, base);
	}

#ifdef CONFIG_NET_CLS_IND
	if (tb[TCA_FW_INDEV]) {
		int ret;
		ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
		if (ret < 0) {
			err = ret;
			goto errout;
		}
		f->ifindex = ret;
	}
#endif /* CONFIG_NET_CLS_IND */

	err = -EINVAL;
	if (tb[TCA_FW_MASK]) {
		mask = nla_get_u32(tb[TCA_FW_MASK]);
		if (mask != head->mask)
			goto errout;
	} else if (head->mask != 0xFFFFFFFF)
		goto errout;

	tcf_exts_change(tp, &f->exts, &e);

	return 0;
errout:
	tcf_exts_destroy(&e);
	return err;
}

static int fw_change(struct net *net, struct sk_buff *in_skb,
		     struct tcf_proto *tp, unsigned long base,
		     u32 handle,
		     struct nlattr **tca,
		     unsigned long *arg, bool ovr)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct fw_filter *f = (struct fw_filter *) *arg;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_FW_MAX + 1];
	int err;

	if (!opt)
		return handle ? -EINVAL : 0; /* Succeed if it is old method. */

	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
	if (err < 0)
		return err;

	if (f) {
		struct fw_filter *pfp, *fnew;
		struct fw_filter __rcu **fp;

		if (f->id != handle && handle)
			return -EINVAL;

		fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
		if (!fnew)
			return -ENOBUFS;

		fnew->id = f->id;
		fnew->res = f->res;
#ifdef CONFIG_NET_CLS_IND
		fnew->ifindex = f->ifindex;
#endif /* CONFIG_NET_CLS_IND */
		fnew->tp = f->tp;

		tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE);

		err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr);
		if (err < 0) {
			kfree(fnew);
			return err;
		}

		fp = &head->ht[fw_hash(fnew->id)];
		for (pfp = rtnl_dereference(*fp); pfp;
		     fp = &pfp->next, pfp = rtnl_dereference(*fp))
			if (pfp == f)
				break;

		RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
		rcu_assign_pointer(*fp, fnew);
		tcf_unbind_filter(tp, &f->res);
		call_rcu(&f->rcu, fw_delete_filter);

		*arg = (unsigned long)fnew;
		return err;
	}

	if (!handle)
		return -EINVAL;

	if (!head) {
		u32 mask = 0xFFFFFFFF;
		if (tb[TCA_FW_MASK])
			mask = nla_get_u32(tb[TCA_FW_MASK]);

		head = kzalloc(sizeof(*head), GFP_KERNEL);
		if (!head)
			return -ENOBUFS;
		head->mask = mask;

		rcu_assign_pointer(tp->root, head);
	}

	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
	if (f == NULL)
		return -ENOBUFS;

	tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
	f->id = handle;
	f->tp = tp;

	err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
	if (err < 0)
		goto errout;

	RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
	rcu_assign_pointer(head->ht[fw_hash(handle)], f);

	*arg = (unsigned long)f;
	return 0;

errout:
	kfree(f);
	return err;
}

static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	int h;

	if (head == NULL)
		arg->stop = 1;

	if (arg->stop)
		return;

	for (h = 0; h < HTSIZE; h++) {
		struct fw_filter *f;

		for (f = rtnl_dereference(head->ht[h]); f;
		     f = rtnl_dereference(f->next)) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
		   struct sk_buff *skb, struct tcmsg *t)
{
	struct fw_head *head = rtnl_dereference(tp->root);
	struct fw_filter *f = (struct fw_filter *)fh;
	struct nlattr *nest;

	if (f == NULL)
		return skb->len;

	t->tcm_handle = f->id;

	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
		return skb->len;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	if (f->res.classid &&
	    nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
		goto nla_put_failure;
#ifdef CONFIG_NET_CLS_IND
	if (f->ifindex) {
		struct net_device *dev;
		dev = __dev_get_by_index(net, f->ifindex);
		if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
			goto nla_put_failure;
	}
#endif /* CONFIG_NET_CLS_IND */
	if (head->mask != 0xFFFFFFFF &&
	    nla_put_u32(skb, TCA_FW_MASK, head->mask))
		goto nla_put_failure;

	if (tcf_exts_dump(skb, &f->exts) < 0)
		goto nla_put_failure;

	nla_nest_end(skb, nest);

	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static struct tcf_proto_ops cls_fw_ops __read_mostly = {
	.kind		=	"fw",
	.classify	=	fw_classify,
	.init		=	fw_init,
	.destroy	=	fw_destroy,
	.get		=	fw_get,
	.change		=	fw_change,
	.delete		=	fw_delete,
	.walk		=	fw_walk,
	.dump		=	fw_dump,
	.owner		=	THIS_MODULE,
};

static int __init init_fw(void)
{
	return register_tcf_proto_ops(&cls_fw_ops);
}

static void __exit exit_fw(void)
{
	unregister_tcf_proto_ops(&cls_fw_ops);
}

module_init(init_fw)
module_exit(exit_fw)
MODULE_LICENSE("GPL");