[NET_SCHED]: Propagate nla_parse return value
[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 nlattr *nla, struct nlattr *est,
58                            struct tc_action *a, int ovr, int bind)
59 {
60         struct nlattr *tb[TCA_MIRRED_MAX + 1];
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, err;
66         int ok_push = 0;
67
68         if (nla == NULL)
69                 return -EINVAL;
70
71         err = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, NULL);
72         if (err < 0)
73                 return err;
74
75         if (tb[TCA_MIRRED_PARMS] == NULL ||
76             nla_len(tb[TCA_MIRRED_PARMS]) < sizeof(*parm))
77                 return -EINVAL;
78         parm = nla_data(tb[TCA_MIRRED_PARMS]);
79
80         if (parm->ifindex) {
81                 dev = __dev_get_by_index(&init_net, parm->ifindex);
82                 if (dev == NULL)
83                         return -ENODEV;
84                 switch (dev->type) {
85                         case ARPHRD_TUNNEL:
86                         case ARPHRD_TUNNEL6:
87                         case ARPHRD_SIT:
88                         case ARPHRD_IPGRE:
89                         case ARPHRD_VOID:
90                         case ARPHRD_NONE:
91                                 ok_push = 0;
92                                 break;
93                         default:
94                                 ok_push = 1;
95                                 break;
96                 }
97         }
98
99         pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
100         if (!pc) {
101                 if (!parm->ifindex)
102                         return -EINVAL;
103                 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
104                                      &mirred_idx_gen, &mirred_hash_info);
105                 if (unlikely(!pc))
106                         return -ENOMEM;
107                 ret = ACT_P_CREATED;
108         } else {
109                 if (!ovr) {
110                         tcf_mirred_release(to_mirred(pc), bind);
111                         return -EEXIST;
112                 }
113         }
114         m = to_mirred(pc);
115
116         spin_lock_bh(&m->tcf_lock);
117         m->tcf_action = parm->action;
118         m->tcfm_eaction = parm->eaction;
119         if (parm->ifindex) {
120                 m->tcfm_ifindex = parm->ifindex;
121                 if (ret != ACT_P_CREATED)
122                         dev_put(m->tcfm_dev);
123                 m->tcfm_dev = dev;
124                 dev_hold(dev);
125                 m->tcfm_ok_push = ok_push;
126         }
127         spin_unlock_bh(&m->tcf_lock);
128         if (ret == ACT_P_CREATED)
129                 tcf_hash_insert(pc, &mirred_hash_info);
130
131         return ret;
132 }
133
134 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
135 {
136         struct tcf_mirred *m = a->priv;
137
138         if (m)
139                 return tcf_mirred_release(m, bind);
140         return 0;
141 }
142
143 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
144                       struct tcf_result *res)
145 {
146         struct tcf_mirred *m = a->priv;
147         struct net_device *dev;
148         struct sk_buff *skb2 = NULL;
149         u32 at = G_TC_AT(skb->tc_verd);
150
151         spin_lock(&m->tcf_lock);
152
153         dev = m->tcfm_dev;
154         m->tcf_tm.lastuse = jiffies;
155
156         if (!(dev->flags&IFF_UP) ) {
157                 if (net_ratelimit())
158                         printk("mirred to Houston: device %s is gone!\n",
159                                dev->name);
160 bad_mirred:
161                 if (skb2 != NULL)
162                         kfree_skb(skb2);
163                 m->tcf_qstats.overlimits++;
164                 m->tcf_bstats.bytes += skb->len;
165                 m->tcf_bstats.packets++;
166                 spin_unlock(&m->tcf_lock);
167                 /* should we be asking for packet to be dropped?
168                  * may make sense for redirect case only
169                 */
170                 return TC_ACT_SHOT;
171         }
172
173         skb2 = skb_act_clone(skb, GFP_ATOMIC);
174         if (skb2 == NULL)
175                 goto bad_mirred;
176         if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
177             m->tcfm_eaction != TCA_EGRESS_REDIR) {
178                 if (net_ratelimit())
179                         printk("tcf_mirred unknown action %d\n",
180                                m->tcfm_eaction);
181                 goto bad_mirred;
182         }
183
184         m->tcf_bstats.bytes += skb2->len;
185         m->tcf_bstats.packets++;
186         if (!(at & AT_EGRESS))
187                 if (m->tcfm_ok_push)
188                         skb_push(skb2, skb2->dev->hard_header_len);
189
190         /* mirror is always swallowed */
191         if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
192                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
193
194         skb2->dev = dev;
195         skb2->iif = skb->dev->ifindex;
196         dev_queue_xmit(skb2);
197         spin_unlock(&m->tcf_lock);
198         return m->tcf_action;
199 }
200
201 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
202 {
203         unsigned char *b = skb_tail_pointer(skb);
204         struct tcf_mirred *m = a->priv;
205         struct tc_mirred opt;
206         struct tcf_t t;
207
208         opt.index = m->tcf_index;
209         opt.action = m->tcf_action;
210         opt.refcnt = m->tcf_refcnt - ref;
211         opt.bindcnt = m->tcf_bindcnt - bind;
212         opt.eaction = m->tcfm_eaction;
213         opt.ifindex = m->tcfm_ifindex;
214         NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
215         t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
216         t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
217         t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
218         NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
219         return skb->len;
220
221 nla_put_failure:
222         nlmsg_trim(skb, b);
223         return -1;
224 }
225
226 static struct tc_action_ops act_mirred_ops = {
227         .kind           =       "mirred",
228         .hinfo          =       &mirred_hash_info,
229         .type           =       TCA_ACT_MIRRED,
230         .capab          =       TCA_CAP_NONE,
231         .owner          =       THIS_MODULE,
232         .act            =       tcf_mirred,
233         .dump           =       tcf_mirred_dump,
234         .cleanup        =       tcf_mirred_cleanup,
235         .lookup         =       tcf_hash_search,
236         .init           =       tcf_mirred_init,
237         .walk           =       tcf_generic_walker
238 };
239
240 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
241 MODULE_DESCRIPTION("Device Mirror/redirect actions");
242 MODULE_LICENSE("GPL");
243
244 static int __init mirred_init_module(void)
245 {
246         printk("Mirror/redirect action on\n");
247         return tcf_register_action(&act_mirred_ops);
248 }
249
250 static void __exit mirred_cleanup_module(void)
251 {
252         tcf_unregister_action(&act_mirred_ops);
253 }
254
255 module_init(mirred_init_module);
256 module_exit(mirred_cleanup_module);