f309ce336803480b090e9100d7cc2978aea78b90
[linux-2.6.git] / net / sched / mirred.c
1 /*
2  * net/sched/mirred.c   packet mirroring and redirect actions
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:     Jamal Hadi Salim (2002-4)
10  *
11  * TODO: Add ingress support (and socket redirect support)
12  *
13  */
14
15 #include <asm/uaccess.h>
16 #include <asm/system.h>
17 #include <asm/bitops.h>
18 #include <linux/config.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/string.h>
23 #include <linux/mm.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/in.h>
27 #include <linux/errno.h>
28 #include <linux/interrupt.h>
29 #include <linux/netdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/rtnetlink.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/proc_fs.h>
35 #include <net/sock.h>
36 #include <net/pkt_sched.h>
37 #include <linux/tc_act/tc_mirred.h>
38 #include <net/tc_act/tc_mirred.h>
39
40 #include <linux/etherdevice.h>
41 #include <linux/if_arp.h>
42
43
44 /* use generic hash table */
45 #define MY_TAB_SIZE     8
46 #define MY_TAB_MASK     (MY_TAB_SIZE - 1)
47 static u32 idx_gen;
48 static struct tcf_mirred *tcf_mirred_ht[MY_TAB_SIZE];
49 static DEFINE_RWLOCK(mirred_lock);
50
51 /* ovewrride the defaults */
52 #define tcf_st          tcf_mirred
53 #define tc_st           tc_mirred
54 #define tcf_t_lock      mirred_lock
55 #define tcf_ht          tcf_mirred_ht
56
57 #define CONFIG_NET_ACT_INIT 1
58 #include <net/pkt_act.h>
59
60 static inline int
61 tcf_mirred_release(struct tcf_mirred *p, int bind)
62 {
63         if (p) {
64                 if (bind)
65                         p->bindcnt--;
66                 p->refcnt--;
67                 if(!p->bindcnt && p->refcnt <= 0) {
68                         dev_put(p->dev);
69                         tcf_hash_destroy(p);
70                         return 1;
71                 }
72         }
73         return 0;
74 }
75
76 static int
77 tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
78                 int ovr, int bind)
79 {
80         struct rtattr *tb[TCA_MIRRED_MAX];
81         struct tc_mirred *parm;
82         struct tcf_mirred *p;
83         struct net_device *dev = NULL;
84         int ret = 0;
85         int ok_push = 0;
86
87         if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
88                 return -EINVAL;
89
90         if (tb[TCA_MIRRED_PARMS-1] == NULL ||
91             RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
92                 return -EINVAL;
93         parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
94
95         if (parm->ifindex) {
96                 dev = __dev_get_by_index(parm->ifindex);
97                 if (dev == NULL)
98                         return -ENODEV;
99                 switch (dev->type) {
100                         case ARPHRD_TUNNEL:
101                         case ARPHRD_TUNNEL6:
102                         case ARPHRD_SIT:
103                         case ARPHRD_IPGRE:
104                         case ARPHRD_VOID:
105                         case ARPHRD_NONE:
106                                 ok_push = 0;
107                                 break;
108                         default:
109                                 ok_push = 1;
110                                 break;
111                 }
112         }
113
114         p = tcf_hash_check(parm->index, a, ovr, bind);
115         if (p == NULL) {
116                 if (!parm->ifindex)
117                         return -EINVAL;
118                 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
119                 if (p == NULL)
120                         return -ENOMEM;
121                 ret = ACT_P_CREATED;
122         } else {
123                 if (!ovr) {
124                         tcf_mirred_release(p, bind);
125                         return -EEXIST;
126                 }
127         }
128
129         spin_lock_bh(&p->lock);
130         p->action = parm->action;
131         p->eaction = parm->eaction;
132         if (parm->ifindex) {
133                 p->ifindex = parm->ifindex;
134                 if (ret != ACT_P_CREATED)
135                         dev_put(p->dev);
136                 p->dev = dev;
137                 dev_hold(dev);
138                 p->ok_push = ok_push;
139         }
140         spin_unlock_bh(&p->lock);
141         if (ret == ACT_P_CREATED)
142                 tcf_hash_insert(p);
143
144         DPRINTK("tcf_mirred_init index %d action %d eaction %d device %s "
145                 "ifindex %d\n", parm->index, parm->action, parm->eaction,
146                 dev->name, parm->ifindex);
147         return ret;
148 }
149
150 static int
151 tcf_mirred_cleanup(struct tc_action *a, int bind)
152 {
153         struct tcf_mirred *p = PRIV(a, mirred);
154
155         if (p != NULL)
156                 return tcf_mirred_release(p, bind);
157         return 0;
158 }
159
160 static int
161 tcf_mirred(struct sk_buff **pskb, struct tc_action *a)
162 {
163         struct tcf_mirred *p = PRIV(a, mirred);
164         struct net_device *dev;
165         struct sk_buff *skb2 = NULL;
166         struct sk_buff *skb = *pskb;
167         u32 at = G_TC_AT(skb->tc_verd);
168
169         spin_lock(&p->lock);
170
171         dev = p->dev;
172         p->tm.lastuse = jiffies;
173
174         if (!(dev->flags&IFF_UP) ) {
175                 if (net_ratelimit())
176                         printk("mirred to Houston: device %s is gone!\n",
177                                dev->name);
178 bad_mirred:
179                 if (skb2 != NULL)
180                         kfree_skb(skb2);
181                 p->qstats.overlimits++;
182                 p->bstats.bytes += skb->len;
183                 p->bstats.packets++;
184                 spin_unlock(&p->lock);
185                 /* should we be asking for packet to be dropped?
186                  * may make sense for redirect case only
187                 */
188                 return TC_ACT_SHOT;
189         }
190
191         skb2 = skb_clone(skb, GFP_ATOMIC);
192         if (skb2 == NULL)
193                 goto bad_mirred;
194         if (p->eaction != TCA_EGRESS_MIRROR && p->eaction != TCA_EGRESS_REDIR) {
195                 if (net_ratelimit())
196                         printk("tcf_mirred unknown action %d\n", p->eaction);
197                 goto bad_mirred;
198         }
199
200         p->bstats.bytes += skb2->len;
201         p->bstats.packets++;
202         if (!(at & AT_EGRESS))
203                 if (p->ok_push)
204                         skb_push(skb2, skb2->dev->hard_header_len);
205
206         /* mirror is always swallowed */
207         if (p->eaction != TCA_EGRESS_MIRROR)
208                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
209
210         skb2->dev = dev;
211         skb2->input_dev = skb->dev;
212         dev_queue_xmit(skb2);
213         spin_unlock(&p->lock);
214         return p->action;
215 }
216
217 static int
218 tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
219 {
220         unsigned char *b = skb->tail;
221         struct tc_mirred opt;
222         struct tcf_mirred *p = PRIV(a, mirred);
223         struct tcf_t t;
224
225         opt.index = p->index;
226         opt.action = p->action;
227         opt.refcnt = p->refcnt - ref;
228         opt.bindcnt = p->bindcnt - bind;
229         opt.eaction = p->eaction;
230         opt.ifindex = p->ifindex;
231         DPRINTK("tcf_mirred_dump index %d action %d eaction %d ifindex %d\n",
232                  p->index, p->action, p->eaction, p->ifindex);
233         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
234         t.install = jiffies_to_clock_t(jiffies - p->tm.install);
235         t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
236         t.expires = jiffies_to_clock_t(p->tm.expires);
237         RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
238         return skb->len;
239
240       rtattr_failure:
241         skb_trim(skb, b - skb->data);
242         return -1;
243 }
244
245 static struct tc_action_ops act_mirred_ops = {
246         .kind           =       "mirred",
247         .type           =       TCA_ACT_MIRRED,
248         .capab          =       TCA_CAP_NONE,
249         .owner          =       THIS_MODULE,
250         .act            =       tcf_mirred,
251         .dump           =       tcf_mirred_dump,
252         .cleanup        =       tcf_mirred_cleanup,
253         .lookup         =       tcf_hash_search,
254         .init           =       tcf_mirred_init,
255         .walk           =       tcf_generic_walker
256 };
257
258 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
259 MODULE_DESCRIPTION("Device Mirror/redirect actions");
260 MODULE_LICENSE("GPL");
261
262 static int __init
263 mirred_init_module(void)
264 {
265         printk("Mirror/redirect action on\n");
266         return tcf_register_action(&act_mirred_ops);
267 }
268
269 static void __exit
270 mirred_cleanup_module(void)
271 {
272         tcf_unregister_action(&act_mirred_ops);
273 }
274
275 module_init(mirred_init_module);
276 module_exit(mirred_cleanup_module);