summaryrefslogtreecommitdiffstats
path: root/net/sched/act_ipt.c
blob: d9e399a7e3d59c8ec53e46e0862e2ca3c83988bc (plain)
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
/*
 * net/sched/act_ipt.c		iptables target interface
 *
 *TODO: Add other tables. For now we only support the ipv4 table targets
 *
 *		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.
 *
 * Copyright:	Jamal Hadi Salim (2002-13)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_ipt.h>
#include <net/tc_act/tc_ipt.h>

#include <linux/netfilter_ipv4/ip_tables.h>


static unsigned int ipt_net_id;
static struct tc_action_ops act_ipt_ops;

static unsigned int xt_net_id;
static struct tc_action_ops act_xt_ops;

static int ipt_init_target(struct net *net, struct xt_entry_target *t,
			   char *table, unsigned int hook)
{
	struct xt_tgchk_param par;
	struct xt_target *target;
	struct ipt_entry e = {};
	int ret = 0;

	target = xt_request_find_target(AF_INET, t->u.user.name,
					t->u.user.revision);
	if (IS_ERR(target))
		return PTR_ERR(target);

	t->u.kernel.target = target;
	memset(&par, 0, sizeof(par));
	par.net       = net;
	par.table     = table;
	par.entryinfo = &e;
	par.target    = target;
	par.targinfo  = t->data;
	par.hook_mask = hook;
	par.family    = NFPROTO_IPV4;

	ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
	if (ret < 0) {
		module_put(t->u.kernel.target->me);
		return ret;
	}
	return 0;
}

static void ipt_destroy_target(struct xt_entry_target *t)
{
	struct xt_tgdtor_param par = {
		.target   = t->u.kernel.target,
		.targinfo = t->data,
		.family   = NFPROTO_IPV4,
	};
	if (par.target->destroy != NULL)
		par.target->destroy(&par);
	module_put(par.target->me);
}

static void tcf_ipt_release(struct tc_action *a, int bind)
{
	struct tcf_ipt *ipt = to_ipt(a);
	ipt_destroy_target(ipt->tcfi_t);
	kfree(ipt->tcfi_tname);
	kfree(ipt->tcfi_t);
}

static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
	[TCA_IPT_TABLE]	= { .type = NLA_STRING, .len = IFNAMSIZ },
	[TCA_IPT_HOOK]	= { .type = NLA_U32 },
	[TCA_IPT_INDEX]	= { .type = NLA_U32 },
	[TCA_IPT_TARG]	= { .len = sizeof(struct xt_entry_target) },
};

static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
			  struct nlattr *est, struct tc_action **a,
			  const struct tc_action_ops *ops, int ovr, int bind)
{
	struct tc_action_net *tn = net_generic(net, id);
	struct nlattr *tb[TCA_IPT_MAX + 1];
	struct tcf_ipt *ipt;
	struct xt_entry_target *td, *t;
	char *tname;
	bool exists = false;
	int ret = 0, err;
	u32 hook = 0;
	u32 index = 0;

	if (nla == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy, NULL);
	if (err < 0)
		return err;

	if (tb[TCA_IPT_INDEX] != NULL)
		index = nla_get_u32(tb[TCA_IPT_INDEX]);

	exists = tcf_idr_check(tn, index, a, bind);
	if (exists && bind)
		return 0;

	if (tb[TCA_IPT_HOOK] == NULL || tb[TCA_IPT_TARG] == NULL) {
		if (exists)
			tcf_idr_release(*a, bind);
		return -EINVAL;
	}

	td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
	if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) {
		if (exists)
			tcf_idr_release(*a, bind);
		return -EINVAL;
	}

	if (!exists) {
		ret = tcf_idr_create(tn, index, est, a, ops, bind,
				     false);
		if (ret)
			return ret;
		ret = ACT_P_CREATED;
	} else {
		if (bind)/* dont override defaults */
			return 0;
		tcf_idr_release(*a, bind);

		if (!ovr)
			return -EEXIST;
	}
	hook = nla_get_u32(tb[TCA_IPT_HOOK]);

	err = -ENOMEM;
	tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
	if (unlikely(!tname))
		goto err1;
	if (tb[TCA_IPT_TABLE] == NULL ||
	    nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ)
		strcpy(tname, "mangle");

	t = kmemdup(td, td->u.target_size, GFP_KERNEL);
	if (unlikely(!t))
		goto err2;

	err = ipt_init_target(net, t, tname, hook);
	if (err < 0)
		goto err3;

	ipt = to_ipt(*a);

	spin_lock_bh(&ipt->tcf_lock);
	if (ret != ACT_P_CREATED) {
		ipt_destroy_target(ipt->tcfi_t);
		kfree(ipt->tcfi_tname);
		kfree(ipt->tcfi_t);
	}
	ipt->tcfi_tname = tname;
	ipt->tcfi_t     = t;
	ipt->tcfi_hook  = hook;
	spin_unlock_bh(&ipt->tcf_lock);
	if (ret == ACT_P_CREATED)
		tcf_idr_insert(tn, *a);
	return ret;

err3:
	kfree(t);
err2:
	kfree(tname);
err1:
	if (ret == ACT_P_CREATED)
		tcf_idr_cleanup(*a, est);
	return err;
}

static int tcf_ipt_init(struct net *net, struct nlattr *nla,
			struct nlattr *est, struct tc_action **a, int ovr,
			int bind)
{
	return __tcf_ipt_init(net, ipt_net_id, nla, est, a, &act_ipt_ops, ovr,
			      bind);
}

static int tcf_xt_init(struct net *net, struct nlattr *nla,
		       struct nlattr *est, struct tc_action **a, int ovr,
		       int bind)
{
	return __tcf_ipt_init(net, xt_net_id, nla, est, a, &act_xt_ops, ovr,
			      bind);
}

static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a,
		   struct tcf_result *res)
{
	int ret = 0, result = 0;
	struct tcf_ipt *ipt = to_ipt(a);
	struct xt_action_param par;
	struct nf_hook_state state = {
		.net	= dev_net(skb->dev),
		.in	= skb->dev,
		.hook	= ipt->tcfi_hook,
		.pf	= NFPROTO_IPV4,
	};

	if (skb_unclone(skb, GFP_ATOMIC))
		return TC_ACT_UNSPEC;

	spin_lock(&ipt->tcf_lock);

	tcf_lastuse_update(&ipt->tcf_tm);
	bstats_update(&ipt->tcf_bstats, skb);

	/* yes, we have to worry about both in and out dev
	 * worry later - danger - this API seems to have changed
	 * from earlier kernels
	 */
	par.state    = &state;
	par.target   = ipt->tcfi_t->u.kernel.target;
	par.targinfo = ipt->tcfi_t->data;
	ret = par.target->target(skb, &par);

	switch (ret) {
	case NF_ACCEPT:
		result = TC_ACT_OK;
		break;
	case NF_DROP:
		result = TC_ACT_SHOT;
		ipt->tcf_qstats.drops++;
		break;
	case XT_CONTINUE:
		result = TC_ACT_PIPE;
		break;
	default:
		net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n",
				       ret);
		result = TC_ACT_OK;
		break;
	}
	spin_unlock(&ipt->tcf_lock);
	return result;

}

static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
			int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_ipt *ipt = to_ipt(a);
	struct xt_entry_target *t;
	struct tcf_t tm;
	struct tc_cnt c;

	/* for simple targets kernel size == user size
	 * user name = target name
	 * for foolproof you need to not assume this
	 */

	t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
	if (unlikely(!t))
		goto nla_put_failure;

	c.bindcnt = ipt->tcf_bindcnt - bind;
	c.refcnt = ipt->tcf_refcnt - ref;
	strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);

	if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) ||
	    nla_put_u32(skb, TCA_IPT_INDEX, ipt->tcf_index) ||
	    nla_put_u32(skb, TCA_IPT_HOOK, ipt->tcfi_hook) ||
	    nla_put(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c) ||
	    nla_put_string(skb, TCA_IPT_TABLE, ipt->tcfi_tname))
		goto nla_put_failure;

	tcf_tm_dump(&tm, &ipt->tcf_tm);
	if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
		goto nla_put_failure;

	kfree(t);
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	kfree(t);
	return -1;
}

static int tcf_ipt_walker(struct net *net, struct sk_buff *skb,
			  struct netlink_callback *cb, int type,
			  const struct tc_action_ops *ops)
{
	struct tc_action_net *tn = net_generic(net, ipt_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops);
}

static int tcf_ipt_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, ipt_net_id);

	return tcf_idr_search(tn, a, index);
}

static struct tc_action_ops act_ipt_ops = {
	.kind		=	"ipt",
	.type		=	TCA_ACT_IPT,
	.owner		=	THIS_MODULE,
	.act		=	tcf_ipt,
	.dump		=	tcf_ipt_dump,
	.cleanup	=	tcf_ipt_release,
	.init		=	tcf_ipt_init,
	.walk		=	tcf_ipt_walker,
	.lookup		=	tcf_ipt_search,
	.size		=	sizeof(struct tcf_ipt),
};

static __net_init int ipt_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, ipt_net_id);

	return tc_action_net_init(tn, &act_ipt_ops);
}

static void __net_exit ipt_exit_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, ipt_net_id);

	tc_action_net_exit(tn);
}

static struct pernet_operations ipt_net_ops = {
	.init = ipt_init_net,
	.exit = ipt_exit_net,
	.id   = &ipt_net_id,
	.size = sizeof(struct tc_action_net),
};

static int tcf_xt_walker(struct net *net, struct sk_buff *skb,
			 struct netlink_callback *cb, int type,
			 const struct tc_action_ops *ops)
{
	struct tc_action_net *tn = net_generic(net, xt_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops);
}

static int tcf_xt_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, xt_net_id);

	return tcf_idr_search(tn, a, index);
}

static struct tc_action_ops act_xt_ops = {
	.kind		=	"xt",
	.type		=	TCA_ACT_XT,
	.owner		=	THIS_MODULE,
	.act		=	tcf_ipt,
	.dump		=	tcf_ipt_dump,
	.cleanup	=	tcf_ipt_release,
	.init		=	tcf_xt_init,
	.walk		=	tcf_xt_walker,
	.lookup		=	tcf_xt_search,
	.size		=	sizeof(struct tcf_ipt),
};

static __net_init int xt_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, xt_net_id);

	return tc_action_net_init(tn, &act_xt_ops);
}

static void __net_exit xt_exit_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, xt_net_id);

	tc_action_net_exit(tn);
}

static struct pernet_operations xt_net_ops = {
	.init = xt_init_net,
	.exit = xt_exit_net,
	.id   = &xt_net_id,
	.size = sizeof(struct tc_action_net),
};

MODULE_AUTHOR("Jamal Hadi Salim(2002-13)");
MODULE_DESCRIPTION("Iptables target actions");
MODULE_LICENSE("GPL");
MODULE_ALIAS("act_xt");

static int __init ipt_init_module(void)
{
	int ret1, ret2;

	ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops);
	if (ret1 < 0)
		pr_err("Failed to load xt action\n");

	ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops);
	if (ret2 < 0)
		pr_err("Failed to load ipt action\n");

	if (ret1 < 0 && ret2 < 0) {
		return ret1;
	} else
		return 0;
}

static void __exit ipt_cleanup_module(void)
{
	tcf_unregister_action(&act_ipt_ops, &ipt_net_ops);
	tcf_unregister_action(&act_xt_ops, &xt_net_ops);
}

module_init(ipt_init_module);
module_exit(ipt_cleanup_module);