[IPSEC]: Get nexthdr from caller in xfrm6_rcv_spi
[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 <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 <net/net_namespace.h>
24 #include <net/netlink.h>
25 #include <net/pkt_sched.h>
26 #include <linux/tc_act/tc_mirred.h>
27 #include <net/tc_act/tc_mirred.h>
28
29 #include <linux/if_arp.h>
30
31 #define MIRRED_TAB_MASK     7
32 static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
33 static u32 mirred_idx_gen;
34 static DEFINE_RWLOCK(mirred_lock);
35
36 static struct tcf_hashinfo mirred_hash_info = {
37         .htab   =       tcf_mirred_ht,
38         .hmask  =       MIRRED_TAB_MASK,
39         .lock   =       &mirred_lock,
40 };
41
42 static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
43 {
44         if (m) {
45                 if (bind)
46                         m->tcf_bindcnt--;
47                 m->tcf_refcnt--;
48                 if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
49                         dev_put(m->tcfm_dev);
50                         tcf_hash_destroy(&m->common, &mirred_hash_info);
51                         return 1;
52                 }
53         }
54         return 0;
55 }
56
57 static int tcf_mirred_init(struct rtattr *rta, struct rtattr *est,
58                            struct tc_action *a, int ovr, int bind)
59 {
60         struct rtattr *tb[TCA_MIRRED_MAX];
61         struct tc_mirred *parm;
62         struct tcf_mirred *m;
63         struct tcf_common *pc;
64         struct net_device *dev = NULL;
65         int ret = 0;
66         int ok_push = 0;
67
68         if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
69                 return -EINVAL;
70
71         if (tb[TCA_MIRRED_PARMS-1] == NULL ||
72             RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
73                 return -EINVAL;
74         parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
75
76         if (parm->ifindex) {
77                 dev = __dev_get_by_index(&init_net, parm->ifindex);
78                 if (dev == NULL)
79                         return -ENODEV;
80                 switch (dev->type) {
81                         case ARPHRD_TUNNEL:
82                         case ARPHRD_TUNNEL6:
83                         case ARPHRD_SIT:
84                         case ARPHRD_IPGRE:
85                         case ARPHRD_VOID:
86                         case ARPHRD_NONE:
87                                 ok_push = 0;
88                                 break;
89                         default:
90                                 ok_push = 1;
91                                 break;
92                 }
93         }
94
95         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
96         if (!pc) {
97                 if (!parm->ifindex)
98                         return -EINVAL;
99                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
100                                      &mirred_idx_gen, &mirred_hash_info);
101                 if (unlikely(!pc))
102                         return -ENOMEM;
103                 ret = ACT_P_CREATED;
104         } else {
105                 if (!ovr) {
106                         tcf_mirred_release(to_mirred(pc), bind);
107                         return -EEXIST;
108                 }
109         }
110         m = to_mirred(pc);
111
112         spin_lock_bh(&m->tcf_lock);
113         m->tcf_action = parm->action;
114         m->tcfm_eaction = parm->eaction;
115         if (parm->ifindex) {
116                 m->tcfm_ifindex = parm->ifindex;
117                 if (ret != ACT_P_CREATED)
118                         dev_put(m->tcfm_dev);
119                 m->tcfm_dev = dev;
120                 dev_hold(dev);
121                 m->tcfm_ok_push = ok_push;
122         }
123         spin_unlock_bh(&m->tcf_lock);
124         if (ret == ACT_P_CREATED)
125                 tcf_hash_insert(pc, &mirred_hash_info);
126
127         return ret;
128 }
129
130 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
131 {
132         struct tcf_mirred *m = a->priv;
133
134         if (m)
135                 return tcf_mirred_release(m, bind);
136         return 0;
137 }
138
139 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
140                       struct tcf_result *res)
141 {
142         struct tcf_mirred *m = a->priv;
143         struct net_device *dev;
144         struct sk_buff *skb2 = NULL;
145         u32 at = G_TC_AT(skb->tc_verd);
146
147         spin_lock(&m->tcf_lock);
148
149         dev = m->tcfm_dev;
150         m->tcf_tm.lastuse = jiffies;
151
152         if (!(dev->flags&IFF_UP) ) {
153                 if (net_ratelimit())
154                         printk("mirred to Houston: device %s is gone!\n",
155                                dev->name);
156 bad_mirred:
157                 if (skb2 != NULL)
158                         kfree_skb(skb2);
159                 m->tcf_qstats.overlimits++;
160                 m->tcf_bstats.bytes += skb->len;
161                 m->tcf_bstats.packets++;
162                 spin_unlock(&m->tcf_lock);
163                 /* should we be asking for packet to be dropped?
164                  * may make sense for redirect case only
165                 */
166                 return TC_ACT_SHOT;
167         }
168
169         skb2 = skb_clone(skb, GFP_ATOMIC);
170         if (skb2 == NULL)
171                 goto bad_mirred;
172         if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
173             m->tcfm_eaction != TCA_EGRESS_REDIR) {
174                 if (net_ratelimit())
175                         printk("tcf_mirred unknown action %d\n",
176                                m->tcfm_eaction);
177                 goto bad_mirred;
178         }
179
180         m->tcf_bstats.bytes += skb2->len;
181         m->tcf_bstats.packets++;
182         if (!(at & AT_EGRESS))
183                 if (m->tcfm_ok_push)
184                         skb_push(skb2, skb2->dev->hard_header_len);
185
186         /* mirror is always swallowed */
187         if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
188                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
189
190         skb2->dev = dev;
191         skb2->iif = skb->dev->ifindex;
192         dev_queue_xmit(skb2);
193         spin_unlock(&m->tcf_lock);
194         return m->tcf_action;
195 }
196
197 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
198 {
199         unsigned char *b = skb_tail_pointer(skb);
200         struct tcf_mirred *m = a->priv;
201         struct tc_mirred opt;
202         struct tcf_t t;
203
204         opt.index = m->tcf_index;
205         opt.action = m->tcf_action;
206         opt.refcnt = m->tcf_refcnt - ref;
207         opt.bindcnt = m->tcf_bindcnt - bind;
208         opt.eaction = m->tcfm_eaction;
209         opt.ifindex = m->tcfm_ifindex;
210         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
211         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
212         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
213         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
214         RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
215         return skb->len;
216
217 rtattr_failure:
218         nlmsg_trim(skb, b);
219         return -1;
220 }
221
222 static struct tc_action_ops act_mirred_ops = {
223         .kind           =       "mirred",
224         .hinfo          =       &mirred_hash_info,
225         .type           =       TCA_ACT_MIRRED,
226         .capab          =       TCA_CAP_NONE,
227         .owner          =       THIS_MODULE,
228         .act            =       tcf_mirred,
229         .dump           =       tcf_mirred_dump,
230         .cleanup        =       tcf_mirred_cleanup,
231         .lookup         =       tcf_hash_search,
232         .init           =       tcf_mirred_init,
233         .walk           =       tcf_generic_walker
234 };
235
236 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
237 MODULE_DESCRIPTION("Device Mirror/redirect actions");
238 MODULE_LICENSE("GPL");
239
240 static int __init mirred_init_module(void)
241 {
242         printk("Mirror/redirect action on\n");
243         return tcf_register_action(&act_mirred_ops);
244 }
245
246 static void __exit mirred_cleanup_module(void)
247 {
248         tcf_unregister_action(&act_mirred_ops);
249 }
250
251 module_init(mirred_init_module);
252 module_exit(mirred_cleanup_module);