[PATCH] net: Add netconsole support to dm9000 driver
[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 <asm/uaccess.h>
16 #include <asm/system.h>
17 #include <asm/bitops.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/string.h>
22 #include <linux/mm.h>
23 #include <linux/socket.h>
24 #include <linux/sockios.h>
25 #include <linux/in.h>
26 #include <linux/errno.h>
27 #include <linux/interrupt.h>
28 #include <linux/netdevice.h>
29 #include <linux/skbuff.h>
30 #include <linux/rtnetlink.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/proc_fs.h>
34 #include <net/sock.h>
35 #include <net/pkt_sched.h>
36 #include <linux/tc_act/tc_mirred.h>
37 #include <net/tc_act/tc_mirred.h>
38
39 #include <linux/etherdevice.h>
40 #include <linux/if_arp.h>
41
42
43 /* use generic hash table */
44 #define MY_TAB_SIZE     8
45 #define MY_TAB_MASK     (MY_TAB_SIZE - 1)
46 static u32 idx_gen;
47 static struct tcf_mirred *tcf_mirred_ht[MY_TAB_SIZE];
48 static DEFINE_RWLOCK(mirred_lock);
49
50 /* ovewrride the defaults */
51 #define tcf_st          tcf_mirred
52 #define tc_st           tc_mirred
53 #define tcf_t_lock      mirred_lock
54 #define tcf_ht          tcf_mirred_ht
55
56 #define CONFIG_NET_ACT_INIT 1
57 #include <net/pkt_act.h>
58
59 static inline int
60 tcf_mirred_release(struct tcf_mirred *p, int bind)
61 {
62         if (p) {
63                 if (bind)
64                         p->bindcnt--;
65                 p->refcnt--;
66                 if(!p->bindcnt && p->refcnt <= 0) {
67                         dev_put(p->dev);
68                         tcf_hash_destroy(p);
69                         return 1;
70                 }
71         }
72         return 0;
73 }
74
75 static int
76 tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
77                 int ovr, int bind)
78 {
79         struct rtattr *tb[TCA_MIRRED_MAX];
80         struct tc_mirred *parm;
81         struct tcf_mirred *p;
82         struct net_device *dev = NULL;
83         int ret = 0;
84         int ok_push = 0;
85
86         if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
87                 return -EINVAL;
88
89         if (tb[TCA_MIRRED_PARMS-1] == NULL ||
90             RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
91                 return -EINVAL;
92         parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
93
94         if (parm->ifindex) {
95                 dev = __dev_get_by_index(parm->ifindex);
96                 if (dev == NULL)
97                         return -ENODEV;
98                 switch (dev->type) {
99                         case ARPHRD_TUNNEL:
100                         case ARPHRD_TUNNEL6:
101                         case ARPHRD_SIT:
102                         case ARPHRD_IPGRE:
103                         case ARPHRD_VOID:
104                         case ARPHRD_NONE:
105                                 ok_push = 0;
106                                 break;
107                         default:
108                                 ok_push = 1;
109                                 break;
110                 }
111         }
112
113         p = tcf_hash_check(parm->index, a, ovr, bind);
114         if (p == NULL) {
115                 if (!parm->ifindex)
116                         return -EINVAL;
117                 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
118                 if (p == NULL)
119                         return -ENOMEM;
120                 ret = ACT_P_CREATED;
121         } else {
122                 if (!ovr) {
123                         tcf_mirred_release(p, bind);
124                         return -EEXIST;
125                 }
126         }
127
128         spin_lock_bh(&p->lock);
129         p->action = parm->action;
130         p->eaction = parm->eaction;
131         if (parm->ifindex) {
132                 p->ifindex = parm->ifindex;
133                 if (ret != ACT_P_CREATED)
134                         dev_put(p->dev);
135                 p->dev = dev;
136                 dev_hold(dev);
137                 p->ok_push = ok_push;
138         }
139         spin_unlock_bh(&p->lock);
140         if (ret == ACT_P_CREATED)
141                 tcf_hash_insert(p);
142
143         DPRINTK("tcf_mirred_init index %d action %d eaction %d device %s "
144                 "ifindex %d\n", parm->index, parm->action, parm->eaction,
145                 dev->name, parm->ifindex);
146         return ret;
147 }
148
149 static int
150 tcf_mirred_cleanup(struct tc_action *a, int bind)
151 {
152         struct tcf_mirred *p = PRIV(a, mirred);
153
154         if (p != NULL)
155                 return tcf_mirred_release(p, bind);
156         return 0;
157 }
158
159 static int
160 tcf_mirred(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
161 {
162         struct tcf_mirred *p = PRIV(a, mirred);
163         struct net_device *dev;
164         struct sk_buff *skb2 = NULL;
165         u32 at = G_TC_AT(skb->tc_verd);
166
167         spin_lock(&p->lock);
168
169         dev = p->dev;
170         p->tm.lastuse = jiffies;
171
172         if (!(dev->flags&IFF_UP) ) {
173                 if (net_ratelimit())
174                         printk("mirred to Houston: device %s is gone!\n",
175                                dev->name);
176 bad_mirred:
177                 if (skb2 != NULL)
178                         kfree_skb(skb2);
179                 p->qstats.overlimits++;
180                 p->bstats.bytes += skb->len;
181                 p->bstats.packets++;
182                 spin_unlock(&p->lock);
183                 /* should we be asking for packet to be dropped?
184                  * may make sense for redirect case only
185                 */
186                 return TC_ACT_SHOT;
187         }
188
189         skb2 = skb_clone(skb, GFP_ATOMIC);
190         if (skb2 == NULL)
191                 goto bad_mirred;
192         if (p->eaction != TCA_EGRESS_MIRROR && p->eaction != TCA_EGRESS_REDIR) {
193                 if (net_ratelimit())
194                         printk("tcf_mirred unknown action %d\n", p->eaction);
195                 goto bad_mirred;
196         }
197
198         p->bstats.bytes += skb2->len;
199         p->bstats.packets++;
200         if (!(at & AT_EGRESS))
201                 if (p->ok_push)
202                         skb_push(skb2, skb2->dev->hard_header_len);
203
204         /* mirror is always swallowed */
205         if (p->eaction != TCA_EGRESS_MIRROR)
206                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
207
208         skb2->dev = dev;
209         skb2->input_dev = skb->dev;
210         dev_queue_xmit(skb2);
211         spin_unlock(&p->lock);
212         return p->action;
213 }
214
215 static int
216 tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
217 {
218         unsigned char *b = skb->tail;
219         struct tc_mirred opt;
220         struct tcf_mirred *p = PRIV(a, mirred);
221         struct tcf_t t;
222
223         opt.index = p->index;
224         opt.action = p->action;
225         opt.refcnt = p->refcnt - ref;
226         opt.bindcnt = p->bindcnt - bind;
227         opt.eaction = p->eaction;
228         opt.ifindex = p->ifindex;
229         DPRINTK("tcf_mirred_dump index %d action %d eaction %d ifindex %d\n",
230                  p->index, p->action, p->eaction, p->ifindex);
231         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
232         t.install = jiffies_to_clock_t(jiffies - p->tm.install);
233         t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
234         t.expires = jiffies_to_clock_t(p->tm.expires);
235         RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
236         return skb->len;
237
238       rtattr_failure:
239         skb_trim(skb, b - skb->data);
240         return -1;
241 }
242
243 static struct tc_action_ops act_mirred_ops = {
244         .kind           =       "mirred",
245         .type           =       TCA_ACT_MIRRED,
246         .capab          =       TCA_CAP_NONE,
247         .owner          =       THIS_MODULE,
248         .act            =       tcf_mirred,
249         .dump           =       tcf_mirred_dump,
250         .cleanup        =       tcf_mirred_cleanup,
251         .lookup         =       tcf_hash_search,
252         .init           =       tcf_mirred_init,
253         .walk           =       tcf_generic_walker
254 };
255
256 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
257 MODULE_DESCRIPTION("Device Mirror/redirect actions");
258 MODULE_LICENSE("GPL");
259
260 static int __init
261 mirred_init_module(void)
262 {
263         printk("Mirror/redirect action on\n");
264         return tcf_register_action(&act_mirred_ops);
265 }
266
267 static void __exit
268 mirred_cleanup_module(void)
269 {
270         tcf_unregister_action(&act_mirred_ops);
271 }
272
273 module_init(mirred_init_module);
274 module_exit(mirred_cleanup_module);