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Commit | Line | Data |
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1da177e4 LT |
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 <asm/uaccess.h> | |
15 | #include <asm/system.h> | |
16 | #include <asm/bitops.h> | |
1da177e4 LT |
17 | #include <linux/types.h> |
18 | #include <linux/kernel.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/socket.h> | |
23 | #include <linux/sockios.h> | |
24 | #include <linux/in.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/netdevice.h> | |
28 | #include <linux/skbuff.h> | |
29 | #include <linux/rtnetlink.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/kmod.h> | |
34 | #include <net/sock.h> | |
35 | #include <net/pkt_sched.h> | |
36 | #include <linux/tc_act/tc_ipt.h> | |
37 | #include <net/tc_act/tc_ipt.h> | |
38 | ||
39 | #include <linux/netfilter_ipv4/ip_tables.h> | |
40 | ||
1da177e4 | 41 | |
e9ce1cd3 DM |
42 | #define IPT_TAB_MASK 15 |
43 | static struct tcf_common *tcf_ipt_ht[IPT_TAB_MASK + 1]; | |
44 | static u32 ipt_idx_gen; | |
1da177e4 LT |
45 | static DEFINE_RWLOCK(ipt_lock); |
46 | ||
e9ce1cd3 DM |
47 | static struct tcf_hashinfo ipt_hash_info = { |
48 | .htab = tcf_ipt_ht, | |
49 | .hmask = IPT_TAB_MASK, | |
50 | .lock = &ipt_lock, | |
51 | }; | |
1da177e4 | 52 | |
e9ce1cd3 | 53 | static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook) |
1da177e4 LT |
54 | { |
55 | struct ipt_target *target; | |
56 | int ret = 0; | |
57 | ||
2e4e6a17 | 58 | target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision); |
1da177e4 LT |
59 | if (!target) |
60 | return -ENOENT; | |
61 | ||
1da177e4 LT |
62 | t->u.kernel.target = target; |
63 | ||
18118cdb PM |
64 | ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t), |
65 | table, hook, 0, 0); | |
66 | if (ret) | |
67 | return ret; | |
68 | ||
1da177e4 | 69 | if (t->u.kernel.target->checkentry |
1c524830 PM |
70 | && !t->u.kernel.target->checkentry(table, NULL, |
71 | t->u.kernel.target, t->data, | |
1da177e4 LT |
72 | t->u.target_size - sizeof(*t), |
73 | hook)) { | |
1da177e4 LT |
74 | module_put(t->u.kernel.target->me); |
75 | ret = -EINVAL; | |
76 | } | |
77 | ||
78 | return ret; | |
79 | } | |
80 | ||
e9ce1cd3 | 81 | static void ipt_destroy_target(struct ipt_entry_target *t) |
1da177e4 LT |
82 | { |
83 | if (t->u.kernel.target->destroy) | |
1c524830 | 84 | t->u.kernel.target->destroy(t->u.kernel.target, t->data, |
1da177e4 LT |
85 | t->u.target_size - sizeof(*t)); |
86 | module_put(t->u.kernel.target->me); | |
87 | } | |
88 | ||
e9ce1cd3 | 89 | static int tcf_ipt_release(struct tcf_ipt *ipt, int bind) |
1da177e4 LT |
90 | { |
91 | int ret = 0; | |
e9ce1cd3 | 92 | if (ipt) { |
1da177e4 | 93 | if (bind) |
e9ce1cd3 DM |
94 | ipt->tcf_bindcnt--; |
95 | ipt->tcf_refcnt--; | |
96 | if (ipt->tcf_bindcnt <= 0 && ipt->tcf_refcnt <= 0) { | |
97 | ipt_destroy_target(ipt->tcfi_t); | |
98 | kfree(ipt->tcfi_tname); | |
99 | kfree(ipt->tcfi_t); | |
100 | tcf_hash_destroy(&ipt->common, &ipt_hash_info); | |
1da177e4 LT |
101 | ret = ACT_P_DELETED; |
102 | } | |
103 | } | |
104 | return ret; | |
105 | } | |
106 | ||
e9ce1cd3 DM |
107 | static int tcf_ipt_init(struct rtattr *rta, struct rtattr *est, |
108 | struct tc_action *a, int ovr, int bind) | |
1da177e4 LT |
109 | { |
110 | struct rtattr *tb[TCA_IPT_MAX]; | |
e9ce1cd3 DM |
111 | struct tcf_ipt *ipt; |
112 | struct tcf_common *pc; | |
1da177e4 LT |
113 | struct ipt_entry_target *td, *t; |
114 | char *tname; | |
115 | int ret = 0, err; | |
116 | u32 hook = 0; | |
117 | u32 index = 0; | |
118 | ||
119 | if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0) | |
120 | return -EINVAL; | |
121 | ||
122 | if (tb[TCA_IPT_HOOK-1] == NULL || | |
123 | RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32)) | |
124 | return -EINVAL; | |
125 | if (tb[TCA_IPT_TARG-1] == NULL || | |
126 | RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t)) | |
127 | return -EINVAL; | |
128 | td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]); | |
129 | if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size) | |
130 | return -EINVAL; | |
131 | ||
132 | if (tb[TCA_IPT_INDEX-1] != NULL && | |
133 | RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32)) | |
134 | index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]); | |
135 | ||
e9ce1cd3 DM |
136 | pc = tcf_hash_check(index, a, bind, &ipt_hash_info); |
137 | if (!pc) { | |
138 | pc = tcf_hash_create(index, est, a, sizeof(*ipt), bind, | |
139 | &ipt_idx_gen, &ipt_hash_info); | |
140 | if (unlikely(!pc)) | |
1da177e4 LT |
141 | return -ENOMEM; |
142 | ret = ACT_P_CREATED; | |
143 | } else { | |
144 | if (!ovr) { | |
e9ce1cd3 | 145 | tcf_ipt_release(to_ipt(pc), bind); |
1da177e4 LT |
146 | return -EEXIST; |
147 | } | |
148 | } | |
e9ce1cd3 | 149 | ipt = to_ipt(pc); |
1da177e4 LT |
150 | |
151 | hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]); | |
152 | ||
153 | err = -ENOMEM; | |
154 | tname = kmalloc(IFNAMSIZ, GFP_KERNEL); | |
e9ce1cd3 | 155 | if (unlikely(!tname)) |
1da177e4 LT |
156 | goto err1; |
157 | if (tb[TCA_IPT_TABLE - 1] == NULL || | |
158 | rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ) | |
159 | strcpy(tname, "mangle"); | |
160 | ||
161 | t = kmalloc(td->u.target_size, GFP_KERNEL); | |
e9ce1cd3 | 162 | if (unlikely(!t)) |
1da177e4 LT |
163 | goto err2; |
164 | memcpy(t, td, td->u.target_size); | |
165 | ||
166 | if ((err = ipt_init_target(t, tname, hook)) < 0) | |
167 | goto err3; | |
168 | ||
e9ce1cd3 | 169 | spin_lock_bh(&ipt->tcf_lock); |
1da177e4 | 170 | if (ret != ACT_P_CREATED) { |
e9ce1cd3 DM |
171 | ipt_destroy_target(ipt->tcfi_t); |
172 | kfree(ipt->tcfi_tname); | |
173 | kfree(ipt->tcfi_t); | |
1da177e4 | 174 | } |
e9ce1cd3 DM |
175 | ipt->tcfi_tname = tname; |
176 | ipt->tcfi_t = t; | |
177 | ipt->tcfi_hook = hook; | |
178 | spin_unlock_bh(&ipt->tcf_lock); | |
1da177e4 | 179 | if (ret == ACT_P_CREATED) |
e9ce1cd3 | 180 | tcf_hash_insert(pc, &ipt_hash_info); |
1da177e4 LT |
181 | return ret; |
182 | ||
183 | err3: | |
184 | kfree(t); | |
185 | err2: | |
186 | kfree(tname); | |
187 | err1: | |
e9ce1cd3 | 188 | kfree(pc); |
1da177e4 LT |
189 | return err; |
190 | } | |
191 | ||
e9ce1cd3 | 192 | static int tcf_ipt_cleanup(struct tc_action *a, int bind) |
1da177e4 | 193 | { |
e9ce1cd3 DM |
194 | struct tcf_ipt *ipt = a->priv; |
195 | return tcf_ipt_release(ipt, bind); | |
1da177e4 LT |
196 | } |
197 | ||
e9ce1cd3 DM |
198 | static int tcf_ipt(struct sk_buff *skb, struct tc_action *a, |
199 | struct tcf_result *res) | |
1da177e4 LT |
200 | { |
201 | int ret = 0, result = 0; | |
e9ce1cd3 | 202 | struct tcf_ipt *ipt = a->priv; |
1da177e4 LT |
203 | |
204 | if (skb_cloned(skb)) { | |
205 | if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) | |
206 | return TC_ACT_UNSPEC; | |
207 | } | |
208 | ||
e9ce1cd3 | 209 | spin_lock(&ipt->tcf_lock); |
1da177e4 | 210 | |
e9ce1cd3 DM |
211 | ipt->tcf_tm.lastuse = jiffies; |
212 | ipt->tcf_bstats.bytes += skb->len; | |
213 | ipt->tcf_bstats.packets++; | |
1da177e4 LT |
214 | |
215 | /* yes, we have to worry about both in and out dev | |
216 | worry later - danger - this API seems to have changed | |
217 | from earlier kernels */ | |
218 | ||
f43c5a0d PM |
219 | /* iptables targets take a double skb pointer in case the skb |
220 | * needs to be replaced. We don't own the skb, so this must not | |
221 | * happen. The pskb_expand_head above should make sure of this */ | |
e9ce1cd3 DM |
222 | ret = ipt->tcfi_t->u.kernel.target->target(&skb, skb->dev, NULL, |
223 | ipt->tcfi_hook, | |
224 | ipt->tcfi_t->u.kernel.target, | |
fe1cb108 | 225 | ipt->tcfi_t->data); |
1da177e4 LT |
226 | switch (ret) { |
227 | case NF_ACCEPT: | |
228 | result = TC_ACT_OK; | |
229 | break; | |
230 | case NF_DROP: | |
231 | result = TC_ACT_SHOT; | |
e9ce1cd3 | 232 | ipt->tcf_qstats.drops++; |
1da177e4 LT |
233 | break; |
234 | case IPT_CONTINUE: | |
235 | result = TC_ACT_PIPE; | |
236 | break; | |
237 | default: | |
238 | if (net_ratelimit()) | |
239 | printk("Bogus netfilter code %d assume ACCEPT\n", ret); | |
240 | result = TC_POLICE_OK; | |
241 | break; | |
242 | } | |
e9ce1cd3 | 243 | spin_unlock(&ipt->tcf_lock); |
1da177e4 LT |
244 | return result; |
245 | ||
246 | } | |
247 | ||
e9ce1cd3 | 248 | static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) |
1da177e4 | 249 | { |
e9ce1cd3 DM |
250 | unsigned char *b = skb->tail; |
251 | struct tcf_ipt *ipt = a->priv; | |
1da177e4 LT |
252 | struct ipt_entry_target *t; |
253 | struct tcf_t tm; | |
254 | struct tc_cnt c; | |
1da177e4 LT |
255 | |
256 | /* for simple targets kernel size == user size | |
257 | ** user name = target name | |
258 | ** for foolproof you need to not assume this | |
259 | */ | |
260 | ||
e9ce1cd3 DM |
261 | t = kmalloc(ipt->tcfi_t->u.user.target_size, GFP_ATOMIC); |
262 | if (unlikely(!t)) | |
1da177e4 LT |
263 | goto rtattr_failure; |
264 | ||
e9ce1cd3 DM |
265 | c.bindcnt = ipt->tcf_bindcnt - bind; |
266 | c.refcnt = ipt->tcf_refcnt - ref; | |
267 | memcpy(t, ipt->tcfi_t, ipt->tcfi_t->u.user.target_size); | |
268 | strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name); | |
269 | ||
270 | RTA_PUT(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t); | |
271 | RTA_PUT(skb, TCA_IPT_INDEX, 4, &ipt->tcf_index); | |
272 | RTA_PUT(skb, TCA_IPT_HOOK, 4, &ipt->tcfi_hook); | |
1da177e4 | 273 | RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c); |
e9ce1cd3 DM |
274 | RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, ipt->tcfi_tname); |
275 | tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install); | |
276 | tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse); | |
277 | tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires); | |
1da177e4 LT |
278 | RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm); |
279 | kfree(t); | |
280 | return skb->len; | |
281 | ||
e9ce1cd3 | 282 | rtattr_failure: |
1da177e4 LT |
283 | skb_trim(skb, b - skb->data); |
284 | kfree(t); | |
285 | return -1; | |
286 | } | |
287 | ||
288 | static struct tc_action_ops act_ipt_ops = { | |
289 | .kind = "ipt", | |
e9ce1cd3 | 290 | .hinfo = &ipt_hash_info, |
1da177e4 LT |
291 | .type = TCA_ACT_IPT, |
292 | .capab = TCA_CAP_NONE, | |
293 | .owner = THIS_MODULE, | |
294 | .act = tcf_ipt, | |
295 | .dump = tcf_ipt_dump, | |
296 | .cleanup = tcf_ipt_cleanup, | |
297 | .lookup = tcf_hash_search, | |
298 | .init = tcf_ipt_init, | |
299 | .walk = tcf_generic_walker | |
300 | }; | |
301 | ||
302 | MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); | |
303 | MODULE_DESCRIPTION("Iptables target actions"); | |
304 | MODULE_LICENSE("GPL"); | |
305 | ||
e9ce1cd3 | 306 | static int __init ipt_init_module(void) |
1da177e4 LT |
307 | { |
308 | return tcf_register_action(&act_ipt_ops); | |
309 | } | |
310 | ||
e9ce1cd3 | 311 | static void __exit ipt_cleanup_module(void) |
1da177e4 LT |
312 | { |
313 | tcf_unregister_action(&act_ipt_ops); | |
314 | } | |
315 | ||
316 | module_init(ipt_init_module); | |
317 | module_exit(ipt_cleanup_module); |