blob: 39a22a3ffe78822636cad6306536916c368e5f19 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 <asm/uaccess.h>
15#include <asm/system.h>
16#include <asm/bitops.h>
17#include <linux/config.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 <linux/kmod.h>
35#include <net/sock.h>
36#include <net/pkt_sched.h>
37#include <linux/tc_act/tc_ipt.h>
38#include <net/tc_act/tc_ipt.h>
39
40#include <linux/netfilter_ipv4/ip_tables.h>
41
42/* use generic hash table */
43#define MY_TAB_SIZE 16
44#define MY_TAB_MASK 15
45
46static u32 idx_gen;
47static struct tcf_ipt *tcf_ipt_ht[MY_TAB_SIZE];
48/* ipt hash table lock */
49static DEFINE_RWLOCK(ipt_lock);
50
51/* ovewrride the defaults */
52#define tcf_st tcf_ipt
53#define tcf_t_lock ipt_lock
54#define tcf_ht tcf_ipt_ht
55
56#define CONFIG_NET_ACT_INIT
57#include <net/pkt_act.h>
58
59static int
60ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook)
61{
62 struct ipt_target *target;
63 int ret = 0;
64
Harald Welte2e4e6a12006-01-12 13:30:04 -080065 target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 if (!target)
67 return -ENOENT;
68
69 DPRINTK("ipt_init_target: found %s\n", target->name);
70 t->u.kernel.target = target;
71
72 if (t->u.kernel.target->checkentry
73 && !t->u.kernel.target->checkentry(table, NULL, t->data,
74 t->u.target_size - sizeof(*t),
75 hook)) {
76 DPRINTK("ipt_init_target: check failed for `%s'.\n",
77 t->u.kernel.target->name);
78 module_put(t->u.kernel.target->me);
79 ret = -EINVAL;
80 }
81
82 return ret;
83}
84
85static void
86ipt_destroy_target(struct ipt_entry_target *t)
87{
88 if (t->u.kernel.target->destroy)
89 t->u.kernel.target->destroy(t->data,
90 t->u.target_size - sizeof(*t));
91 module_put(t->u.kernel.target->me);
92}
93
94static int
95tcf_ipt_release(struct tcf_ipt *p, int bind)
96{
97 int ret = 0;
98 if (p) {
99 if (bind)
100 p->bindcnt--;
101 p->refcnt--;
102 if (p->bindcnt <= 0 && p->refcnt <= 0) {
103 ipt_destroy_target(p->t);
104 kfree(p->tname);
105 kfree(p->t);
106 tcf_hash_destroy(p);
107 ret = ACT_P_DELETED;
108 }
109 }
110 return ret;
111}
112
113static int
114tcf_ipt_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
115 int ovr, int bind)
116{
117 struct rtattr *tb[TCA_IPT_MAX];
118 struct tcf_ipt *p;
119 struct ipt_entry_target *td, *t;
120 char *tname;
121 int ret = 0, err;
122 u32 hook = 0;
123 u32 index = 0;
124
125 if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0)
126 return -EINVAL;
127
128 if (tb[TCA_IPT_HOOK-1] == NULL ||
129 RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32))
130 return -EINVAL;
131 if (tb[TCA_IPT_TARG-1] == NULL ||
132 RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t))
133 return -EINVAL;
134 td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]);
135 if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size)
136 return -EINVAL;
137
138 if (tb[TCA_IPT_INDEX-1] != NULL &&
139 RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32))
140 index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]);
141
142 p = tcf_hash_check(index, a, ovr, bind);
143 if (p == NULL) {
144 p = tcf_hash_create(index, est, a, sizeof(*p), ovr, bind);
145 if (p == NULL)
146 return -ENOMEM;
147 ret = ACT_P_CREATED;
148 } else {
149 if (!ovr) {
150 tcf_ipt_release(p, bind);
151 return -EEXIST;
152 }
153 }
154
155 hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]);
156
157 err = -ENOMEM;
158 tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
159 if (tname == NULL)
160 goto err1;
161 if (tb[TCA_IPT_TABLE - 1] == NULL ||
162 rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ)
163 strcpy(tname, "mangle");
164
165 t = kmalloc(td->u.target_size, GFP_KERNEL);
166 if (t == NULL)
167 goto err2;
168 memcpy(t, td, td->u.target_size);
169
170 if ((err = ipt_init_target(t, tname, hook)) < 0)
171 goto err3;
172
173 spin_lock_bh(&p->lock);
174 if (ret != ACT_P_CREATED) {
175 ipt_destroy_target(p->t);
176 kfree(p->tname);
177 kfree(p->t);
178 }
179 p->tname = tname;
180 p->t = t;
181 p->hook = hook;
182 spin_unlock_bh(&p->lock);
183 if (ret == ACT_P_CREATED)
184 tcf_hash_insert(p);
185 return ret;
186
187err3:
188 kfree(t);
189err2:
190 kfree(tname);
191err1:
192 kfree(p);
193 return err;
194}
195
196static int
197tcf_ipt_cleanup(struct tc_action *a, int bind)
198{
199 struct tcf_ipt *p = PRIV(a, ipt);
200 return tcf_ipt_release(p, bind);
201}
202
203static int
Patrick McHardyf43c5a02006-01-08 22:15:34 -0800204tcf_ipt(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
206 int ret = 0, result = 0;
207 struct tcf_ipt *p = PRIV(a, ipt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 if (skb_cloned(skb)) {
210 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
211 return TC_ACT_UNSPEC;
212 }
213
214 spin_lock(&p->lock);
215
216 p->tm.lastuse = jiffies;
217 p->bstats.bytes += skb->len;
218 p->bstats.packets++;
219
220 /* yes, we have to worry about both in and out dev
221 worry later - danger - this API seems to have changed
222 from earlier kernels */
223
Patrick McHardyf43c5a02006-01-08 22:15:34 -0800224 /* iptables targets take a double skb pointer in case the skb
225 * needs to be replaced. We don't own the skb, so this must not
226 * happen. The pskb_expand_head above should make sure of this */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 ret = p->t->u.kernel.target->target(&skb, skb->dev, NULL,
228 p->hook, p->t->data, NULL);
229 switch (ret) {
230 case NF_ACCEPT:
231 result = TC_ACT_OK;
232 break;
233 case NF_DROP:
234 result = TC_ACT_SHOT;
235 p->qstats.drops++;
236 break;
237 case IPT_CONTINUE:
238 result = TC_ACT_PIPE;
239 break;
240 default:
241 if (net_ratelimit())
242 printk("Bogus netfilter code %d assume ACCEPT\n", ret);
243 result = TC_POLICE_OK;
244 break;
245 }
246 spin_unlock(&p->lock);
247 return result;
248
249}
250
251static int
252tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
253{
254 struct ipt_entry_target *t;
255 struct tcf_t tm;
256 struct tc_cnt c;
257 unsigned char *b = skb->tail;
258 struct tcf_ipt *p = PRIV(a, ipt);
259
260 /* for simple targets kernel size == user size
261 ** user name = target name
262 ** for foolproof you need to not assume this
263 */
264
265 t = kmalloc(p->t->u.user.target_size, GFP_ATOMIC);
266 if (t == NULL)
267 goto rtattr_failure;
268
269 c.bindcnt = p->bindcnt - bind;
270 c.refcnt = p->refcnt - ref;
271 memcpy(t, p->t, p->t->u.user.target_size);
272 strcpy(t->u.user.name, p->t->u.kernel.target->name);
273
274 DPRINTK("\ttcf_ipt_dump tablename %s length %d\n", p->tname,
275 strlen(p->tname));
276 DPRINTK("\tdump target name %s size %d size user %d "
277 "data[0] %x data[1] %x\n", p->t->u.kernel.target->name,
278 p->t->u.target_size, p->t->u.user.target_size,
279 p->t->data[0], p->t->data[1]);
280 RTA_PUT(skb, TCA_IPT_TARG, p->t->u.user.target_size, t);
281 RTA_PUT(skb, TCA_IPT_INDEX, 4, &p->index);
282 RTA_PUT(skb, TCA_IPT_HOOK, 4, &p->hook);
283 RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c);
284 RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, p->tname);
285 tm.install = jiffies_to_clock_t(jiffies - p->tm.install);
286 tm.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
287 tm.expires = jiffies_to_clock_t(p->tm.expires);
288 RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm);
289 kfree(t);
290 return skb->len;
291
292 rtattr_failure:
293 skb_trim(skb, b - skb->data);
294 kfree(t);
295 return -1;
296}
297
298static struct tc_action_ops act_ipt_ops = {
299 .kind = "ipt",
300 .type = TCA_ACT_IPT,
301 .capab = TCA_CAP_NONE,
302 .owner = THIS_MODULE,
303 .act = tcf_ipt,
304 .dump = tcf_ipt_dump,
305 .cleanup = tcf_ipt_cleanup,
306 .lookup = tcf_hash_search,
307 .init = tcf_ipt_init,
308 .walk = tcf_generic_walker
309};
310
311MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
312MODULE_DESCRIPTION("Iptables target actions");
313MODULE_LICENSE("GPL");
314
315static int __init
316ipt_init_module(void)
317{
318 return tcf_register_action(&act_ipt_ops);
319}
320
321static void __exit
322ipt_cleanup_module(void)
323{
324 tcf_unregister_action(&act_ipt_ops);
325}
326
327module_init(ipt_init_module);
328module_exit(ipt_cleanup_module);