ipv6: fix bad free of addrconf_init_net
[pandora-kernel.git] / 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 <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/skbuff.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/gfp.h>
24 #include <net/net_namespace.h>
25 #include <net/netlink.h>
26 #include <net/pkt_sched.h>
27 #include <linux/tc_act/tc_mirred.h>
28 #include <net/tc_act/tc_mirred.h>
29
30 #include <linux/if_arp.h>
31
32 #define MIRRED_TAB_MASK     7
33 static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
34 static u32 mirred_idx_gen;
35 static DEFINE_RWLOCK(mirred_lock);
36 static LIST_HEAD(mirred_list);
37
38 static struct tcf_hashinfo mirred_hash_info = {
39         .htab   =       tcf_mirred_ht,
40         .hmask  =       MIRRED_TAB_MASK,
41         .lock   =       &mirred_lock,
42 };
43
44 static int tcf_mirred_release(struct tcf_mirred *m, int bind)
45 {
46         if (m) {
47                 if (bind)
48                         m->tcf_bindcnt--;
49                 m->tcf_refcnt--;
50                 if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
51                         list_del(&m->tcfm_list);
52                         if (m->tcfm_dev)
53                                 dev_put(m->tcfm_dev);
54                         tcf_hash_destroy(&m->common, &mirred_hash_info);
55                         return 1;
56                 }
57         }
58         return 0;
59 }
60
61 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
62         [TCA_MIRRED_PARMS]      = { .len = sizeof(struct tc_mirred) },
63 };
64
65 static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
66                            struct tc_action *a, int ovr, int bind)
67 {
68         struct nlattr *tb[TCA_MIRRED_MAX + 1];
69         struct tc_mirred *parm;
70         struct tcf_mirred *m;
71         struct tcf_common *pc;
72         struct net_device *dev;
73         int ret, ok_push = 0;
74
75         if (nla == NULL)
76                 return -EINVAL;
77         ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
78         if (ret < 0)
79                 return ret;
80         if (tb[TCA_MIRRED_PARMS] == NULL)
81                 return -EINVAL;
82         parm = nla_data(tb[TCA_MIRRED_PARMS]);
83         switch (parm->eaction) {
84         case TCA_EGRESS_MIRROR:
85         case TCA_EGRESS_REDIR:
86                 break;
87         default:
88                 return -EINVAL;
89         }
90         if (parm->ifindex) {
91                 dev = __dev_get_by_index(&init_net, parm->ifindex);
92                 if (dev == NULL)
93                         return -ENODEV;
94                 switch (dev->type) {
95                 case ARPHRD_TUNNEL:
96                 case ARPHRD_TUNNEL6:
97                 case ARPHRD_SIT:
98                 case ARPHRD_IPGRE:
99                 case ARPHRD_VOID:
100                 case ARPHRD_NONE:
101                         ok_push = 0;
102                         break;
103                 default:
104                         ok_push = 1;
105                         break;
106                 }
107         } else {
108                 dev = NULL;
109         }
110
111         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
112         if (!pc) {
113                 if (dev == NULL)
114                         return -EINVAL;
115                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
116                                      &mirred_idx_gen, &mirred_hash_info);
117                 if (IS_ERR(pc))
118                         return PTR_ERR(pc);
119                 ret = ACT_P_CREATED;
120         } else {
121                 if (!ovr) {
122                         tcf_mirred_release(to_mirred(pc), bind);
123                         return -EEXIST;
124                 }
125         }
126         m = to_mirred(pc);
127
128         spin_lock_bh(&m->tcf_lock);
129         m->tcf_action = parm->action;
130         m->tcfm_eaction = parm->eaction;
131         if (dev != NULL) {
132                 m->tcfm_ifindex = parm->ifindex;
133                 if (ret != ACT_P_CREATED)
134                         dev_put(m->tcfm_dev);
135                 dev_hold(dev);
136                 m->tcfm_dev = dev;
137                 m->tcfm_ok_push = ok_push;
138         }
139         spin_unlock_bh(&m->tcf_lock);
140         if (ret == ACT_P_CREATED) {
141                 list_add(&m->tcfm_list, &mirred_list);
142                 tcf_hash_insert(pc, &mirred_hash_info);
143         }
144
145         return ret;
146 }
147
148 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
149 {
150         struct tcf_mirred *m = a->priv;
151
152         if (m)
153                 return tcf_mirred_release(m, bind);
154         return 0;
155 }
156
157 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
158                       struct tcf_result *res)
159 {
160         struct tcf_mirred *m = a->priv;
161         struct net_device *dev;
162         struct sk_buff *skb2;
163         u32 at;
164         int retval, err = 1;
165
166         spin_lock(&m->tcf_lock);
167         m->tcf_tm.lastuse = jiffies;
168         bstats_update(&m->tcf_bstats, skb);
169
170         dev = m->tcfm_dev;
171         if (!dev) {
172                 printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
173                 goto out;
174         }
175
176         if (!(dev->flags & IFF_UP)) {
177                 if (net_ratelimit())
178                         pr_notice("tc mirred to Houston: device %s is down\n",
179                                   dev->name);
180                 goto out;
181         }
182
183         at = G_TC_AT(skb->tc_verd);
184         skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
185         if (skb2 == NULL)
186                 goto out;
187
188         if (!(at & AT_EGRESS)) {
189                 if (m->tcfm_ok_push)
190                         skb_push(skb2, skb2->dev->hard_header_len);
191         }
192
193         /* mirror is always swallowed */
194         if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
195                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
196
197         skb2->skb_iif = skb->dev->ifindex;
198         skb2->dev = dev;
199         err = dev_queue_xmit(skb2);
200
201 out:
202         if (err) {
203                 m->tcf_qstats.overlimits++;
204                 /* should we be asking for packet to be dropped?
205                  * may make sense for redirect case only
206                  */
207                 retval = TC_ACT_SHOT;
208         } else {
209                 retval = m->tcf_action;
210         }
211         spin_unlock(&m->tcf_lock);
212
213         return retval;
214 }
215
216 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
217 {
218         unsigned char *b = skb_tail_pointer(skb);
219         struct tcf_mirred *m = a->priv;
220         struct tc_mirred opt = {
221                 .index   = m->tcf_index,
222                 .action  = m->tcf_action,
223                 .refcnt  = m->tcf_refcnt - ref,
224                 .bindcnt = m->tcf_bindcnt - bind,
225                 .eaction = m->tcfm_eaction,
226                 .ifindex = m->tcfm_ifindex,
227         };
228         struct tcf_t t;
229
230         NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
231         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
232         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
233         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
234         NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
235         return skb->len;
236
237 nla_put_failure:
238         nlmsg_trim(skb, b);
239         return -1;
240 }
241
242 static int mirred_device_event(struct notifier_block *unused,
243                                unsigned long event, void *ptr)
244 {
245         struct net_device *dev = ptr;
246         struct tcf_mirred *m;
247
248         if (event == NETDEV_UNREGISTER)
249                 list_for_each_entry(m, &mirred_list, tcfm_list) {
250                         if (m->tcfm_dev == dev) {
251                                 dev_put(dev);
252                                 m->tcfm_dev = NULL;
253                         }
254                 }
255
256         return NOTIFY_DONE;
257 }
258
259 static struct notifier_block mirred_device_notifier = {
260         .notifier_call = mirred_device_event,
261 };
262
263
264 static struct tc_action_ops act_mirred_ops = {
265         .kind           =       "mirred",
266         .hinfo          =       &mirred_hash_info,
267         .type           =       TCA_ACT_MIRRED,
268         .capab          =       TCA_CAP_NONE,
269         .owner          =       THIS_MODULE,
270         .act            =       tcf_mirred,
271         .dump           =       tcf_mirred_dump,
272         .cleanup        =       tcf_mirred_cleanup,
273         .lookup         =       tcf_hash_search,
274         .init           =       tcf_mirred_init,
275         .walk           =       tcf_generic_walker
276 };
277
278 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
279 MODULE_DESCRIPTION("Device Mirror/redirect actions");
280 MODULE_LICENSE("GPL");
281
282 static int __init mirred_init_module(void)
283 {
284         int err = register_netdevice_notifier(&mirred_device_notifier);
285         if (err)
286                 return err;
287
288         pr_info("Mirror/redirect action on\n");
289         return tcf_register_action(&act_mirred_ops);
290 }
291
292 static void __exit mirred_cleanup_module(void)
293 {
294         unregister_netdevice_notifier(&mirred_device_notifier);
295         tcf_unregister_action(&act_mirred_ops);
296 }
297
298 module_init(mirred_init_module);
299 module_exit(mirred_cleanup_module);