[ETH]: Validate address in eth_mac_addr
[linux-2.6] / net / sched / act_ipt.c
1 /*
2  * net/sched/ipt.c      iptables target interface
3  *
4  *TODO: Add other tables. For now we only support the ipv4 table targets
5  *
6  *              This program is free software; you can redistribute it and/or
7  *              modify it under the terms of the GNU General Public License
8  *              as published by the Free Software Foundation; either version
9  *              2 of the License, or (at your option) any later version.
10  *
11  * Copyright:   Jamal Hadi Salim (2002-4)
12  */
13
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/skbuff.h>
19 #include <linux/rtnetlink.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <net/netlink.h>
23 #include <net/pkt_sched.h>
24 #include <linux/tc_act/tc_ipt.h>
25 #include <net/tc_act/tc_ipt.h>
26
27 #include <linux/netfilter_ipv4/ip_tables.h>
28
29
30 #define IPT_TAB_MASK     15
31 static struct tcf_common *tcf_ipt_ht[IPT_TAB_MASK + 1];
32 static u32 ipt_idx_gen;
33 static DEFINE_RWLOCK(ipt_lock);
34
35 static struct tcf_hashinfo ipt_hash_info = {
36         .htab   =       tcf_ipt_ht,
37         .hmask  =       IPT_TAB_MASK,
38         .lock   =       &ipt_lock,
39 };
40
41 static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook)
42 {
43         struct xt_target *target;
44         int ret = 0;
45
46         target = xt_request_find_target(AF_INET, t->u.user.name,
47                                         t->u.user.revision);
48         if (!target)
49                 return -ENOENT;
50
51         t->u.kernel.target = target;
52
53         ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
54                               table, hook, 0, 0);
55         if (ret) {
56                 module_put(t->u.kernel.target->me);
57                 return ret;
58         }
59         if (t->u.kernel.target->checkentry
60             && !t->u.kernel.target->checkentry(table, NULL,
61                                                t->u.kernel.target, t->data,
62                                                hook)) {
63                 module_put(t->u.kernel.target->me);
64                 ret = -EINVAL;
65         }
66
67         return ret;
68 }
69
70 static void ipt_destroy_target(struct ipt_entry_target *t)
71 {
72         if (t->u.kernel.target->destroy)
73                 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
74         module_put(t->u.kernel.target->me);
75 }
76
77 static int tcf_ipt_release(struct tcf_ipt *ipt, int bind)
78 {
79         int ret = 0;
80         if (ipt) {
81                 if (bind)
82                         ipt->tcf_bindcnt--;
83                 ipt->tcf_refcnt--;
84                 if (ipt->tcf_bindcnt <= 0 && ipt->tcf_refcnt <= 0) {
85                         ipt_destroy_target(ipt->tcfi_t);
86                         kfree(ipt->tcfi_tname);
87                         kfree(ipt->tcfi_t);
88                         tcf_hash_destroy(&ipt->common, &ipt_hash_info);
89                         ret = ACT_P_DELETED;
90                 }
91         }
92         return ret;
93 }
94
95 static int tcf_ipt_init(struct rtattr *rta, struct rtattr *est,
96                         struct tc_action *a, int ovr, int bind)
97 {
98         struct rtattr *tb[TCA_IPT_MAX];
99         struct tcf_ipt *ipt;
100         struct tcf_common *pc;
101         struct ipt_entry_target *td, *t;
102         char *tname;
103         int ret = 0, err;
104         u32 hook = 0;
105         u32 index = 0;
106
107         if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0)
108                 return -EINVAL;
109
110         if (tb[TCA_IPT_HOOK-1] == NULL ||
111             RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32))
112                 return -EINVAL;
113         if (tb[TCA_IPT_TARG-1] == NULL ||
114             RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t))
115                 return -EINVAL;
116         td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]);
117         if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size)
118                 return -EINVAL;
119
120         if (tb[TCA_IPT_INDEX-1] != NULL &&
121             RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32))
122                 index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]);
123
124         pc = tcf_hash_check(index, a, bind, &ipt_hash_info);
125         if (!pc) {
126                 pc = tcf_hash_create(index, est, a, sizeof(*ipt), bind,
127                                      &ipt_idx_gen, &ipt_hash_info);
128                 if (unlikely(!pc))
129                         return -ENOMEM;
130                 ret = ACT_P_CREATED;
131         } else {
132                 if (!ovr) {
133                         tcf_ipt_release(to_ipt(pc), bind);
134                         return -EEXIST;
135                 }
136         }
137         ipt = to_ipt(pc);
138
139         hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]);
140
141         err = -ENOMEM;
142         tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
143         if (unlikely(!tname))
144                 goto err1;
145         if (tb[TCA_IPT_TABLE - 1] == NULL ||
146             rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ)
147                 strcpy(tname, "mangle");
148
149         t = kmemdup(td, td->u.target_size, GFP_KERNEL);
150         if (unlikely(!t))
151                 goto err2;
152
153         if ((err = ipt_init_target(t, tname, hook)) < 0)
154                 goto err3;
155
156         spin_lock_bh(&ipt->tcf_lock);
157         if (ret != ACT_P_CREATED) {
158                 ipt_destroy_target(ipt->tcfi_t);
159                 kfree(ipt->tcfi_tname);
160                 kfree(ipt->tcfi_t);
161         }
162         ipt->tcfi_tname = tname;
163         ipt->tcfi_t     = t;
164         ipt->tcfi_hook  = hook;
165         spin_unlock_bh(&ipt->tcf_lock);
166         if (ret == ACT_P_CREATED)
167                 tcf_hash_insert(pc, &ipt_hash_info);
168         return ret;
169
170 err3:
171         kfree(t);
172 err2:
173         kfree(tname);
174 err1:
175         kfree(pc);
176         return err;
177 }
178
179 static int tcf_ipt_cleanup(struct tc_action *a, int bind)
180 {
181         struct tcf_ipt *ipt = a->priv;
182         return tcf_ipt_release(ipt, bind);
183 }
184
185 static int tcf_ipt(struct sk_buff *skb, struct tc_action *a,
186                    struct tcf_result *res)
187 {
188         int ret = 0, result = 0;
189         struct tcf_ipt *ipt = a->priv;
190
191         if (skb_cloned(skb)) {
192                 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
193                         return TC_ACT_UNSPEC;
194         }
195
196         spin_lock(&ipt->tcf_lock);
197
198         ipt->tcf_tm.lastuse = jiffies;
199         ipt->tcf_bstats.bytes += skb->len;
200         ipt->tcf_bstats.packets++;
201
202         /* yes, we have to worry about both in and out dev
203          worry later - danger - this API seems to have changed
204          from earlier kernels */
205
206         /* iptables targets take a double skb pointer in case the skb
207          * needs to be replaced. We don't own the skb, so this must not
208          * happen. The pskb_expand_head above should make sure of this */
209         ret = ipt->tcfi_t->u.kernel.target->target(&skb, skb->dev, NULL,
210                                                    ipt->tcfi_hook,
211                                                    ipt->tcfi_t->u.kernel.target,
212                                                    ipt->tcfi_t->data);
213         switch (ret) {
214         case NF_ACCEPT:
215                 result = TC_ACT_OK;
216                 break;
217         case NF_DROP:
218                 result = TC_ACT_SHOT;
219                 ipt->tcf_qstats.drops++;
220                 break;
221         case IPT_CONTINUE:
222                 result = TC_ACT_PIPE;
223                 break;
224         default:
225                 if (net_ratelimit())
226                         printk("Bogus netfilter code %d assume ACCEPT\n", ret);
227                 result = TC_POLICE_OK;
228                 break;
229         }
230         spin_unlock(&ipt->tcf_lock);
231         return result;
232
233 }
234
235 static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
236 {
237         unsigned char *b = skb_tail_pointer(skb);
238         struct tcf_ipt *ipt = a->priv;
239         struct ipt_entry_target *t;
240         struct tcf_t tm;
241         struct tc_cnt c;
242
243         /* for simple targets kernel size == user size
244         ** user name = target name
245         ** for foolproof you need to not assume this
246         */
247
248         t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
249         if (unlikely(!t))
250                 goto rtattr_failure;
251
252         c.bindcnt = ipt->tcf_bindcnt - bind;
253         c.refcnt = ipt->tcf_refcnt - ref;
254         strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
255
256         RTA_PUT(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t);
257         RTA_PUT(skb, TCA_IPT_INDEX, 4, &ipt->tcf_index);
258         RTA_PUT(skb, TCA_IPT_HOOK, 4, &ipt->tcfi_hook);
259         RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c);
260         RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, ipt->tcfi_tname);
261         tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install);
262         tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse);
263         tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires);
264         RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm);
265         kfree(t);
266         return skb->len;
267
268 rtattr_failure:
269         nlmsg_trim(skb, b);
270         kfree(t);
271         return -1;
272 }
273
274 static struct tc_action_ops act_ipt_ops = {
275         .kind           =       "ipt",
276         .hinfo          =       &ipt_hash_info,
277         .type           =       TCA_ACT_IPT,
278         .capab          =       TCA_CAP_NONE,
279         .owner          =       THIS_MODULE,
280         .act            =       tcf_ipt,
281         .dump           =       tcf_ipt_dump,
282         .cleanup        =       tcf_ipt_cleanup,
283         .lookup         =       tcf_hash_search,
284         .init           =       tcf_ipt_init,
285         .walk           =       tcf_generic_walker
286 };
287
288 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
289 MODULE_DESCRIPTION("Iptables target actions");
290 MODULE_LICENSE("GPL");
291
292 static int __init ipt_init_module(void)
293 {
294         return tcf_register_action(&act_ipt_ops);
295 }
296
297 static void __exit ipt_cleanup_module(void)
298 {
299         tcf_unregister_action(&act_ipt_ops);
300 }
301
302 module_init(ipt_init_module);
303 module_exit(ipt_cleanup_module);