ip: fix mc_loop checks for tunnels with multicast outer addresses
[linux-2.6.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 <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;
69         int ret, ok_push = 0;
70
71         if (nla == NULL)
72                 return -EINVAL;
73         ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
74         if (ret < 0)
75                 return ret;
76         if (tb[TCA_MIRRED_PARMS] == NULL)
77                 return -EINVAL;
78         parm = nla_data(tb[TCA_MIRRED_PARMS]);
79         switch (parm->eaction) {
80         case TCA_EGRESS_MIRROR:
81         case TCA_EGRESS_REDIR:
82                 break;
83         default:
84                 return -EINVAL;
85         }
86         if (parm->ifindex) {
87                 dev = __dev_get_by_index(&init_net, 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         } else {
104                 dev = NULL;
105         }
106
107         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
108         if (!pc) {
109                 if (dev == NULL)
110                         return -EINVAL;
111                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
112                                      &mirred_idx_gen, &mirred_hash_info);
113                 if (IS_ERR(pc))
114                         return PTR_ERR(pc);
115                 ret = ACT_P_CREATED;
116         } else {
117                 if (!ovr) {
118                         tcf_mirred_release(to_mirred(pc), bind);
119                         return -EEXIST;
120                 }
121         }
122         m = to_mirred(pc);
123
124         spin_lock_bh(&m->tcf_lock);
125         m->tcf_action = parm->action;
126         m->tcfm_eaction = parm->eaction;
127         if (dev != NULL) {
128                 m->tcfm_ifindex = parm->ifindex;
129                 if (ret != ACT_P_CREATED)
130                         dev_put(m->tcfm_dev);
131                 dev_hold(dev);
132                 m->tcfm_dev = dev;
133                 m->tcfm_ok_push = ok_push;
134         }
135         spin_unlock_bh(&m->tcf_lock);
136         if (ret == ACT_P_CREATED)
137                 tcf_hash_insert(pc, &mirred_hash_info);
138
139         return ret;
140 }
141
142 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
143 {
144         struct tcf_mirred *m = a->priv;
145
146         if (m)
147                 return tcf_mirred_release(m, bind);
148         return 0;
149 }
150
151 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
152                       struct tcf_result *res)
153 {
154         struct tcf_mirred *m = a->priv;
155         struct net_device *dev;
156         struct sk_buff *skb2;
157         u32 at;
158         int retval, err = 1;
159
160         spin_lock(&m->tcf_lock);
161         m->tcf_tm.lastuse = jiffies;
162
163         dev = m->tcfm_dev;
164         if (!(dev->flags & IFF_UP)) {
165                 if (net_ratelimit())
166                         printk("mirred to Houston: device %s is gone!\n",
167                                dev->name);
168                 goto out;
169         }
170
171         skb2 = skb_act_clone(skb, GFP_ATOMIC);
172         if (skb2 == NULL)
173                 goto out;
174
175         m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
176         m->tcf_bstats.packets++;
177         at = G_TC_AT(skb->tc_verd);
178         if (!(at & AT_EGRESS)) {
179                 if (m->tcfm_ok_push)
180                         skb_push(skb2, skb2->dev->hard_header_len);
181         }
182
183         /* mirror is always swallowed */
184         if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
185                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
186
187         skb2->dev = dev;
188         skb2->skb_iif = skb->dev->ifindex;
189         dev_queue_xmit(skb2);
190         err = 0;
191
192 out:
193         if (err) {
194                 m->tcf_qstats.overlimits++;
195                 m->tcf_bstats.bytes += qdisc_pkt_len(skb);
196                 m->tcf_bstats.packets++;
197                 /* should we be asking for packet to be dropped?
198                  * may make sense for redirect case only
199                  */
200                 retval = TC_ACT_SHOT;
201         } else {
202                 retval = m->tcf_action;
203         }
204         spin_unlock(&m->tcf_lock);
205
206         return retval;
207 }
208
209 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
210 {
211         unsigned char *b = skb_tail_pointer(skb);
212         struct tcf_mirred *m = a->priv;
213         struct tc_mirred opt;
214         struct tcf_t t;
215
216         opt.index = m->tcf_index;
217         opt.action = m->tcf_action;
218         opt.refcnt = m->tcf_refcnt - ref;
219         opt.bindcnt = m->tcf_bindcnt - bind;
220         opt.eaction = m->tcfm_eaction;
221         opt.ifindex = m->tcfm_ifindex;
222         NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
223         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
224         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
225         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
226         NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
227         return skb->len;
228
229 nla_put_failure:
230         nlmsg_trim(skb, b);
231         return -1;
232 }
233
234 static struct tc_action_ops act_mirred_ops = {
235         .kind           =       "mirred",
236         .hinfo          =       &mirred_hash_info,
237         .type           =       TCA_ACT_MIRRED,
238         .capab          =       TCA_CAP_NONE,
239         .owner          =       THIS_MODULE,
240         .act            =       tcf_mirred,
241         .dump           =       tcf_mirred_dump,
242         .cleanup        =       tcf_mirred_cleanup,
243         .lookup         =       tcf_hash_search,
244         .init           =       tcf_mirred_init,
245         .walk           =       tcf_generic_walker
246 };
247
248 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
249 MODULE_DESCRIPTION("Device Mirror/redirect actions");
250 MODULE_LICENSE("GPL");
251
252 static int __init mirred_init_module(void)
253 {
254         printk("Mirror/redirect action on\n");
255         return tcf_register_action(&act_mirred_ops);
256 }
257
258 static void __exit mirred_cleanup_module(void)
259 {
260         tcf_unregister_action(&act_mirred_ops);
261 }
262
263 module_init(mirred_init_module);
264 module_exit(mirred_cleanup_module);