tridentfb: add imageblit acceleration for Blade3D family
[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 const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
58         [TCA_MIRRED_PARMS]      = { .len = sizeof(struct tc_mirred) },
59 };
60
61 static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
62                            struct tc_action *a, int ovr, int bind)
63 {
64         struct nlattr *tb[TCA_MIRRED_MAX + 1];
65         struct tc_mirred *parm;
66         struct tcf_mirred *m;
67         struct tcf_common *pc;
68         struct net_device *dev = NULL;
69         int ret = 0, err;
70         int ok_push = 0;
71
72         if (nla == NULL)
73                 return -EINVAL;
74
75         err = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
76         if (err < 0)
77                 return err;
78
79         if (tb[TCA_MIRRED_PARMS] == NULL)
80                 return -EINVAL;
81         parm = nla_data(tb[TCA_MIRRED_PARMS]);
82
83         if (parm->ifindex) {
84                 dev = __dev_get_by_index(&init_net, parm->ifindex);
85                 if (dev == NULL)
86                         return -ENODEV;
87                 switch (dev->type) {
88                         case ARPHRD_TUNNEL:
89                         case ARPHRD_TUNNEL6:
90                         case ARPHRD_SIT:
91                         case ARPHRD_IPGRE:
92                         case ARPHRD_VOID:
93                         case ARPHRD_NONE:
94                                 ok_push = 0;
95                                 break;
96                         default:
97                                 ok_push = 1;
98                                 break;
99                 }
100         }
101
102         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
103         if (!pc) {
104                 if (!parm->ifindex)
105                         return -EINVAL;
106                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
107                                      &mirred_idx_gen, &mirred_hash_info);
108                 if (unlikely(!pc))
109                         return -ENOMEM;
110                 ret = ACT_P_CREATED;
111         } else {
112                 if (!ovr) {
113                         tcf_mirred_release(to_mirred(pc), bind);
114                         return -EEXIST;
115                 }
116         }
117         m = to_mirred(pc);
118
119         spin_lock_bh(&m->tcf_lock);
120         m->tcf_action = parm->action;
121         m->tcfm_eaction = parm->eaction;
122         if (parm->ifindex) {
123                 m->tcfm_ifindex = parm->ifindex;
124                 if (ret != ACT_P_CREATED)
125                         dev_put(m->tcfm_dev);
126                 m->tcfm_dev = dev;
127                 dev_hold(dev);
128                 m->tcfm_ok_push = ok_push;
129         }
130         spin_unlock_bh(&m->tcf_lock);
131         if (ret == ACT_P_CREATED)
132                 tcf_hash_insert(pc, &mirred_hash_info);
133
134         return ret;
135 }
136
137 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
138 {
139         struct tcf_mirred *m = a->priv;
140
141         if (m)
142                 return tcf_mirred_release(m, bind);
143         return 0;
144 }
145
146 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
147                       struct tcf_result *res)
148 {
149         struct tcf_mirred *m = a->priv;
150         struct net_device *dev;
151         struct sk_buff *skb2 = NULL;
152         u32 at = G_TC_AT(skb->tc_verd);
153
154         spin_lock(&m->tcf_lock);
155
156         dev = m->tcfm_dev;
157         m->tcf_tm.lastuse = jiffies;
158
159         if (!(dev->flags&IFF_UP) ) {
160                 if (net_ratelimit())
161                         printk("mirred to Houston: device %s is gone!\n",
162                                dev->name);
163 bad_mirred:
164                 if (skb2 != NULL)
165                         kfree_skb(skb2);
166                 m->tcf_qstats.overlimits++;
167                 m->tcf_bstats.bytes += qdisc_pkt_len(skb);
168                 m->tcf_bstats.packets++;
169                 spin_unlock(&m->tcf_lock);
170                 /* should we be asking for packet to be dropped?
171                  * may make sense for redirect case only
172                 */
173                 return TC_ACT_SHOT;
174         }
175
176         skb2 = skb_act_clone(skb, GFP_ATOMIC);
177         if (skb2 == NULL)
178                 goto bad_mirred;
179         if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
180             m->tcfm_eaction != TCA_EGRESS_REDIR) {
181                 if (net_ratelimit())
182                         printk("tcf_mirred unknown action %d\n",
183                                m->tcfm_eaction);
184                 goto bad_mirred;
185         }
186
187         m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
188         m->tcf_bstats.packets++;
189         if (!(at & AT_EGRESS))
190                 if (m->tcfm_ok_push)
191                         skb_push(skb2, skb2->dev->hard_header_len);
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->dev = dev;
198         skb2->iif = skb->dev->ifindex;
199         dev_queue_xmit(skb2);
200         spin_unlock(&m->tcf_lock);
201         return m->tcf_action;
202 }
203
204 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
205 {
206         unsigned char *b = skb_tail_pointer(skb);
207         struct tcf_mirred *m = a->priv;
208         struct tc_mirred opt;
209         struct tcf_t t;
210
211         opt.index = m->tcf_index;
212         opt.action = m->tcf_action;
213         opt.refcnt = m->tcf_refcnt - ref;
214         opt.bindcnt = m->tcf_bindcnt - bind;
215         opt.eaction = m->tcfm_eaction;
216         opt.ifindex = m->tcfm_ifindex;
217         NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
218         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
219         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
220         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
221         NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
222         return skb->len;
223
224 nla_put_failure:
225         nlmsg_trim(skb, b);
226         return -1;
227 }
228
229 static struct tc_action_ops act_mirred_ops = {
230         .kind           =       "mirred",
231         .hinfo          =       &mirred_hash_info,
232         .type           =       TCA_ACT_MIRRED,
233         .capab          =       TCA_CAP_NONE,
234         .owner          =       THIS_MODULE,
235         .act            =       tcf_mirred,
236         .dump           =       tcf_mirred_dump,
237         .cleanup        =       tcf_mirred_cleanup,
238         .lookup         =       tcf_hash_search,
239         .init           =       tcf_mirred_init,
240         .walk           =       tcf_generic_walker
241 };
242
243 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
244 MODULE_DESCRIPTION("Device Mirror/redirect actions");
245 MODULE_LICENSE("GPL");
246
247 static int __init mirred_init_module(void)
248 {
249         printk("Mirror/redirect action on\n");
250         return tcf_register_action(&act_mirred_ops);
251 }
252
253 static void __exit mirred_cleanup_module(void)
254 {
255         tcf_unregister_action(&act_mirred_ops);
256 }
257
258 module_init(mirred_init_module);
259 module_exit(mirred_cleanup_module);