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