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