summaryrefslogtreecommitdiffstats
path: root/net/sched/pedit.c
blob: 678be6a645fbf41548d2c120ccd278ed0e03042a (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
/*
 * net/sched/pedit.c	Generic packet editor
 *
 *		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:	Jamal Hadi Salim (2002-4)
 */

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_pedit.h>
#include <net/tc_act/tc_pedit.h>


#define PEDIT_DEB 1

/* use generic hash table */
#define MY_TAB_SIZE     16
#define MY_TAB_MASK     15
static u32 idx_gen;
static struct tcf_pedit *tcf_pedit_ht[MY_TAB_SIZE];
static DEFINE_RWLOCK(pedit_lock);

#define tcf_st		tcf_pedit
#define tc_st		tc_pedit
#define tcf_t_lock	pedit_lock
#define tcf_ht		tcf_pedit_ht

#define CONFIG_NET_ACT_INIT 1
#include <net/pkt_act.h>

static int
tcf_pedit_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
               int ovr, int bind)
{
	struct rtattr *tb[TCA_PEDIT_MAX];
	struct tc_pedit *parm;
	int ret = 0;
	struct tcf_pedit *p;
	struct tc_pedit_key *keys = NULL;
	int ksize;

	if (rta == NULL || rtattr_parse_nested(tb, TCA_PEDIT_MAX, rta) < 0)
		return -EINVAL;

	if (tb[TCA_PEDIT_PARMS - 1] == NULL ||
	    RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm))
		return -EINVAL;
	parm = RTA_DATA(tb[TCA_PEDIT_PARMS-1]);
	ksize = parm->nkeys * sizeof(struct tc_pedit_key);
	if (RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm) + ksize)
		return -EINVAL;

	p = tcf_hash_check(parm->index, a, ovr, bind);
	if (p == NULL) {
		if (!parm->nkeys)
			return -EINVAL;
		p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
		if (p == NULL)
			return -ENOMEM;
		keys = kmalloc(ksize, GFP_KERNEL);
		if (keys == NULL) {
			kfree(p);
			return -ENOMEM;
		}
		ret = ACT_P_CREATED;
	} else {
		if (!ovr) {
			tcf_hash_release(p, bind);
			return -EEXIST;
		}
		if (p->nkeys && p->nkeys != parm->nkeys) {
			keys = kmalloc(ksize, GFP_KERNEL);
			if (keys == NULL)
				return -ENOMEM;
		}
	}

	spin_lock_bh(&p->lock);
	p->flags = parm->flags;
	p->action = parm->action;
	if (keys) {
		kfree(p->keys);
		p->keys = keys;
		p->nkeys = parm->nkeys;
	}
	memcpy(p->keys, parm->keys, ksize);
	spin_unlock_bh(&p->lock);
	if (ret == ACT_P_CREATED)
		tcf_hash_insert(p);
	return ret;
}

static int
tcf_pedit_cleanup(struct tc_action *a, int bind)
{
	struct tcf_pedit *p = PRIV(a, pedit);

	if (p != NULL) {
		struct tc_pedit_key *keys = p->keys;
		if (tcf_hash_release(p, bind)) {
			kfree(keys);
			return 1;
		}
	}
	return 0;
}

static int
tcf_pedit(struct sk_buff **pskb, struct tc_action *a)
{
	struct tcf_pedit *p = PRIV(a, pedit);
	struct sk_buff *skb = *pskb;
	int i, munged = 0;
	u8 *pptr;

	if (!(skb->tc_verd & TC_OK2MUNGE)) {
		/* should we set skb->cloned? */
		if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
			return p->action;
		}
	}

	pptr = skb->nh.raw;

	spin_lock(&p->lock);

	p->tm.lastuse = jiffies;

	if (p->nkeys > 0) {
		struct tc_pedit_key *tkey = p->keys;

		for (i = p->nkeys; i > 0; i--, tkey++) {
			u32 *ptr;
			int offset = tkey->off;

			if (tkey->offmask) {
				if (skb->len > tkey->at) {
					 char *j = pptr + tkey->at;
					 offset += ((*j & tkey->offmask) >> 
					           tkey->shift);
				} else {
					goto bad;
				}
			}

			if (offset % 4) {
				printk("offset must be on 32 bit boundaries\n");
				goto bad;
			}
			if (skb->len < 0 || (offset > 0 && offset > skb->len)) {
				printk("offset %d cant exceed pkt length %d\n",
				       offset, skb->len);
				goto bad;
			}

			ptr = (u32 *)(pptr+offset);
			/* just do it, baby */
			*ptr = ((*ptr & tkey->mask) ^ tkey->val);
			munged++;
		}
		
		if (munged)
			skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
		goto done;
	} else {
		printk("pedit BUG: index %d\n",p->index);
	}

bad:
	p->qstats.overlimits++;
done:
	p->bstats.bytes += skb->len;
	p->bstats.packets++;
	spin_unlock(&p->lock);
	return p->action;
}

static int
tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,int bind, int ref)
{
	unsigned char *b = skb->tail;
	struct tc_pedit *opt;
	struct tcf_pedit *p = PRIV(a, pedit);
	struct tcf_t t;
	int s; 
		
	s = sizeof(*opt) + p->nkeys * sizeof(struct tc_pedit_key);

	/* netlink spinlocks held above us - must use ATOMIC */
	opt = kmalloc(s, GFP_ATOMIC);
	if (opt == NULL)
		return -ENOBUFS;
	memset(opt, 0, s);

	memcpy(opt->keys, p->keys, p->nkeys * sizeof(struct tc_pedit_key));
	opt->index = p->index;
	opt->nkeys = p->nkeys;
	opt->flags = p->flags;
	opt->action = p->action;
	opt->refcnt = p->refcnt - ref;
	opt->bindcnt = p->bindcnt - bind;


#ifdef PEDIT_DEB
	{                
		/* Debug - get rid of later */
		int i;
		struct tc_pedit_key *key = opt->keys;

		for (i=0; i<opt->nkeys; i++, key++) {
			printk( "\n key #%d",i);
			printk( "  at %d: val %08x mask %08x",
			(unsigned int)key->off,
			(unsigned int)key->val,
			(unsigned int)key->mask);
		}
	}
#endif

	RTA_PUT(skb, TCA_PEDIT_PARMS, s, opt);
	t.install = jiffies_to_clock_t(jiffies - p->tm.install);
	t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
	t.expires = jiffies_to_clock_t(p->tm.expires);
	RTA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t);
	return skb->len;

rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

static
struct tc_action_ops act_pedit_ops = {
	.kind		=	"pedit",
	.type		=	TCA_ACT_PEDIT,
	.capab		=	TCA_CAP_NONE,
	.owner		=	THIS_MODULE,
	.act		=	tcf_pedit,
	.dump		=	tcf_pedit_dump,
	.cleanup	=	tcf_pedit_cleanup,
	.lookup		=	tcf_hash_search,
	.init		=	tcf_pedit_init,
	.walk		=	tcf_generic_walker
};

MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
MODULE_DESCRIPTION("Generic Packet Editor actions");
MODULE_LICENSE("GPL");

static int __init
pedit_init_module(void)
{
	return tcf_register_action(&act_pedit_ops);
}

static void __exit
pedit_cleanup_module(void)
{
	tcf_unregister_action(&act_pedit_ops);
}

module_init(pedit_init_module);
module_exit(pedit_cleanup_module);