Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6
[linux-2.6] / net / sched / act_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/types.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/string.h>
22 #include <linux/mm.h>
23 #include <linux/socket.h>
24 #include <linux/sockios.h>
25 #include <linux/in.h>
26 #include <linux/errno.h>
27 #include <linux/interrupt.h>
28 #include <linux/netdevice.h>
29 #include <linux/skbuff.h>
30 #include <linux/rtnetlink.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/proc_fs.h>
34 #include <net/sock.h>
35 #include <net/pkt_sched.h>
36 #include <linux/tc_act/tc_mirred.h>
37 #include <net/tc_act/tc_mirred.h>
38
39 #include <linux/etherdevice.h>
40 #include <linux/if_arp.h>
41
42 #define MIRRED_TAB_MASK     7
43 static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
44 static u32 mirred_idx_gen;
45 static DEFINE_RWLOCK(mirred_lock);
46
47 static struct tcf_hashinfo mirred_hash_info = {
48         .htab   =       tcf_mirred_ht,
49         .hmask  =       MIRRED_TAB_MASK,
50         .lock   =       &mirred_lock,
51 };
52
53 static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
54 {
55         if (m) {
56                 if (bind)
57                         m->tcf_bindcnt--;
58                 m->tcf_refcnt--;
59                 if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
60                         dev_put(m->tcfm_dev);
61                         tcf_hash_destroy(&m->common, &mirred_hash_info);
62                         return 1;
63                 }
64         }
65         return 0;
66 }
67
68 static int tcf_mirred_init(struct rtattr *rta, struct rtattr *est,
69                            struct tc_action *a, int ovr, int bind)
70 {
71         struct rtattr *tb[TCA_MIRRED_MAX];
72         struct tc_mirred *parm;
73         struct tcf_mirred *m;
74         struct tcf_common *pc;
75         struct net_device *dev = NULL;
76         int ret = 0;
77         int ok_push = 0;
78
79         if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
80                 return -EINVAL;
81
82         if (tb[TCA_MIRRED_PARMS-1] == NULL ||
83             RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
84                 return -EINVAL;
85         parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
86
87         if (parm->ifindex) {
88                 dev = __dev_get_by_index(parm->ifindex);
89                 if (dev == NULL)
90                         return -ENODEV;
91                 switch (dev->type) {
92                         case ARPHRD_TUNNEL:
93                         case ARPHRD_TUNNEL6:
94                         case ARPHRD_SIT:
95                         case ARPHRD_IPGRE:
96                         case ARPHRD_VOID:
97                         case ARPHRD_NONE:
98                                 ok_push = 0;
99                                 break;
100                         default:
101                                 ok_push = 1;
102                                 break;
103                 }
104         }
105
106         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
107         if (!pc) {
108                 if (!parm->ifindex)
109                         return -EINVAL;
110                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
111                                      &mirred_idx_gen, &mirred_hash_info);
112                 if (unlikely(!pc))
113                         return -ENOMEM;
114                 ret = ACT_P_CREATED;
115         } else {
116                 if (!ovr) {
117                         tcf_mirred_release(to_mirred(pc), bind);
118                         return -EEXIST;
119                 }
120         }
121         m = to_mirred(pc);
122
123         spin_lock_bh(&m->tcf_lock);
124         m->tcf_action = parm->action;
125         m->tcfm_eaction = parm->eaction;
126         if (parm->ifindex) {
127                 m->tcfm_ifindex = parm->ifindex;
128                 if (ret != ACT_P_CREATED)
129                         dev_put(m->tcfm_dev);
130                 m->tcfm_dev = dev;
131                 dev_hold(dev);
132                 m->tcfm_ok_push = ok_push;
133         }
134         spin_unlock_bh(&m->tcf_lock);
135         if (ret == ACT_P_CREATED)
136                 tcf_hash_insert(pc, &mirred_hash_info);
137
138         return ret;
139 }
140
141 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
142 {
143         struct tcf_mirred *m = a->priv;
144
145         if (m)
146                 return tcf_mirred_release(m, bind);
147         return 0;
148 }
149
150 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
151                       struct tcf_result *res)
152 {
153         struct tcf_mirred *m = a->priv;
154         struct net_device *dev;
155         struct sk_buff *skb2 = NULL;
156         u32 at = G_TC_AT(skb->tc_verd);
157
158         spin_lock(&m->tcf_lock);
159
160         dev = m->tcfm_dev;
161         m->tcf_tm.lastuse = jiffies;
162
163         if (!(dev->flags&IFF_UP) ) {
164                 if (net_ratelimit())
165                         printk("mirred to Houston: device %s is gone!\n",
166                                dev->name);
167 bad_mirred:
168                 if (skb2 != NULL)
169                         kfree_skb(skb2);
170                 m->tcf_qstats.overlimits++;
171                 m->tcf_bstats.bytes += skb->len;
172                 m->tcf_bstats.packets++;
173                 spin_unlock(&m->tcf_lock);
174                 /* should we be asking for packet to be dropped?
175                  * may make sense for redirect case only
176                 */
177                 return TC_ACT_SHOT;
178         }
179
180         skb2 = skb_clone(skb, GFP_ATOMIC);
181         if (skb2 == NULL)
182                 goto bad_mirred;
183         if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
184             m->tcfm_eaction != TCA_EGRESS_REDIR) {
185                 if (net_ratelimit())
186                         printk("tcf_mirred unknown action %d\n",
187                                m->tcfm_eaction);
188                 goto bad_mirred;
189         }
190
191         m->tcf_bstats.bytes += skb2->len;
192         m->tcf_bstats.packets++;
193         if (!(at & AT_EGRESS))
194                 if (m->tcfm_ok_push)
195                         skb_push(skb2, skb2->dev->hard_header_len);
196
197         /* mirror is always swallowed */
198         if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
199                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
200
201         skb2->dev = dev;
202         skb2->input_dev = skb->dev;
203         dev_queue_xmit(skb2);
204         spin_unlock(&m->tcf_lock);
205         return m->tcf_action;
206 }
207
208 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
209 {
210         unsigned char *b = skb->tail;
211         struct tcf_mirred *m = a->priv;
212         struct tc_mirred opt;
213         struct tcf_t t;
214
215         opt.index = m->tcf_index;
216         opt.action = m->tcf_action;
217         opt.refcnt = m->tcf_refcnt - ref;
218         opt.bindcnt = m->tcf_bindcnt - bind;
219         opt.eaction = m->tcfm_eaction;
220         opt.ifindex = m->tcfm_ifindex;
221         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
222         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
223         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
224         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
225         RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
226         return skb->len;
227
228 rtattr_failure:
229         skb_trim(skb, b - skb->data);
230         return -1;
231 }
232
233 static struct tc_action_ops act_mirred_ops = {
234         .kind           =       "mirred",
235         .hinfo          =       &mirred_hash_info,
236         .type           =       TCA_ACT_MIRRED,
237         .capab          =       TCA_CAP_NONE,
238         .owner          =       THIS_MODULE,
239         .act            =       tcf_mirred,
240         .dump           =       tcf_mirred_dump,
241         .cleanup        =       tcf_mirred_cleanup,
242         .lookup         =       tcf_hash_search,
243         .init           =       tcf_mirred_init,
244         .walk           =       tcf_generic_walker
245 };
246
247 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
248 MODULE_DESCRIPTION("Device Mirror/redirect actions");
249 MODULE_LICENSE("GPL");
250
251 static int __init mirred_init_module(void)
252 {
253         printk("Mirror/redirect action on\n");
254         return tcf_register_action(&act_mirred_ops);
255 }
256
257 static void __exit mirred_cleanup_module(void)
258 {
259         tcf_unregister_action(&act_mirred_ops);
260 }
261
262 module_init(mirred_init_module);
263 module_exit(mirred_cleanup_module);