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
|
/*
* net/sched/mirred.c packet mirroring and redirect actions
*
* 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)
*
* TODO: Add ingress support (and socket redirect support)
*
*/
#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/gfp.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_mirred.h>
#include <net/tc_act/tc_mirred.h>
#include <linux/if_arp.h>
#define MIRRED_TAB_MASK 7
static LIST_HEAD(mirred_list);
static void tcf_mirred_release(struct tc_action *a, int bind)
{
struct tcf_mirred *m = to_mirred(a);
list_del(&m->tcfm_list);
if (m->tcfm_dev)
dev_put(m->tcfm_dev);
}
static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
};
static int tcf_mirred_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action *a, int ovr,
int bind)
{
struct nlattr *tb[TCA_MIRRED_MAX + 1];
struct tc_mirred *parm;
struct tcf_mirred *m;
struct net_device *dev;
int ret, ok_push = 0;
if (nla == NULL)
return -EINVAL;
ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
if (ret < 0)
return ret;
if (tb[TCA_MIRRED_PARMS] == NULL)
return -EINVAL;
parm = nla_data(tb[TCA_MIRRED_PARMS]);
switch (parm->eaction) {
case TCA_EGRESS_MIRROR:
case TCA_EGRESS_REDIR:
break;
default:
return -EINVAL;
}
if (parm->ifindex) {
dev = __dev_get_by_index(net, parm->ifindex);
if (dev == NULL)
return -ENODEV;
switch (dev->type) {
case ARPHRD_TUNNEL:
case ARPHRD_TUNNEL6:
case ARPHRD_SIT:
case ARPHRD_IPGRE:
case ARPHRD_VOID:
case ARPHRD_NONE:
ok_push = 0;
break;
default:
ok_push = 1;
break;
}
} else {
dev = NULL;
}
if (!tcf_hash_check(parm->index, a, bind)) {
if (dev == NULL)
return -EINVAL;
ret = tcf_hash_create(parm->index, est, a, sizeof(*m), bind);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
if (!ovr) {
tcf_hash_release(a, bind);
return -EEXIST;
}
}
m = to_mirred(a);
spin_lock_bh(&m->tcf_lock);
m->tcf_action = parm->action;
m->tcfm_eaction = parm->eaction;
if (dev != NULL) {
m->tcfm_ifindex = parm->ifindex;
if (ret != ACT_P_CREATED)
dev_put(m->tcfm_dev);
dev_hold(dev);
m->tcfm_dev = dev;
m->tcfm_ok_push = ok_push;
}
spin_unlock_bh(&m->tcf_lock);
if (ret == ACT_P_CREATED) {
list_add(&m->tcfm_list, &mirred_list);
tcf_hash_insert(a);
}
return ret;
}
static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_mirred *m = a->priv;
struct net_device *dev;
struct sk_buff *skb2;
u32 at;
int retval, err = 1;
spin_lock(&m->tcf_lock);
m->tcf_tm.lastuse = jiffies;
bstats_update(&m->tcf_bstats, skb);
dev = m->tcfm_dev;
if (!dev) {
printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
goto out;
}
if (!(dev->flags & IFF_UP)) {
net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
dev->name);
goto out;
}
at = G_TC_AT(skb->tc_verd);
skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
if (skb2 == NULL)
goto out;
if (!(at & AT_EGRESS)) {
if (m->tcfm_ok_push)
skb_push(skb2, skb2->dev->hard_header_len);
}
/* mirror is always swallowed */
if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
skb2->skb_iif = skb->dev->ifindex;
skb2->dev = dev;
err = dev_queue_xmit(skb2);
out:
if (err) {
m->tcf_qstats.overlimits++;
if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
retval = TC_ACT_SHOT;
else
retval = m->tcf_action;
} else
retval = m->tcf_action;
spin_unlock(&m->tcf_lock);
return retval;
}
static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_mirred *m = a->priv;
struct tc_mirred opt = {
.index = m->tcf_index,
.action = m->tcf_action,
.refcnt = m->tcf_refcnt - ref,
.bindcnt = m->tcf_bindcnt - bind,
.eaction = m->tcfm_eaction,
.ifindex = m->tcfm_ifindex,
};
struct tcf_t t;
if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int mirred_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct tcf_mirred *m;
if (event == NETDEV_UNREGISTER)
list_for_each_entry(m, &mirred_list, tcfm_list) {
if (m->tcfm_dev == dev) {
dev_put(dev);
m->tcfm_dev = NULL;
}
}
return NOTIFY_DONE;
}
static struct notifier_block mirred_device_notifier = {
.notifier_call = mirred_device_event,
};
static struct tc_action_ops act_mirred_ops = {
.kind = "mirred",
.type = TCA_ACT_MIRRED,
.owner = THIS_MODULE,
.act = tcf_mirred,
.dump = tcf_mirred_dump,
.cleanup = tcf_mirred_release,
.init = tcf_mirred_init,
};
MODULE_AUTHOR("Jamal Hadi Salim(2002)");
MODULE_DESCRIPTION("Device Mirror/redirect actions");
MODULE_LICENSE("GPL");
static int __init mirred_init_module(void)
{
int err = register_netdevice_notifier(&mirred_device_notifier);
if (err)
return err;
pr_info("Mirror/redirect action on\n");
return tcf_register_action(&act_mirred_ops, MIRRED_TAB_MASK);
}
static void __exit mirred_cleanup_module(void)
{
tcf_unregister_action(&act_mirred_ops);
unregister_netdevice_notifier(&mirred_device_notifier);
}
module_init(mirred_init_module);
module_exit(mirred_cleanup_module);
|
