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> | |
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 | ||
46 | static u32 idx_gen; | |
47 | static struct tcf_ipt *tcf_ipt_ht[MY_TAB_SIZE]; | |
48 | /* ipt hash table lock */ | |
49 | static 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 | ||
59 | static int | |
60 | ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook) | |
61 | { | |
62 | struct ipt_target *target; | |
63 | int ret = 0; | |
64 | ||
2e4e6a17 | 65 | target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision); |
1da177e4 LT |
66 | 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 | |
1c524830 PM |
73 | && !t->u.kernel.target->checkentry(table, NULL, |
74 | t->u.kernel.target, t->data, | |
1da177e4 LT |
75 | t->u.target_size - sizeof(*t), |
76 | hook)) { | |
77 | DPRINTK("ipt_init_target: check failed for `%s'.\n", | |
78 | t->u.kernel.target->name); | |
79 | module_put(t->u.kernel.target->me); | |
80 | ret = -EINVAL; | |
81 | } | |
82 | ||
83 | return ret; | |
84 | } | |
85 | ||
86 | static void | |
87 | ipt_destroy_target(struct ipt_entry_target *t) | |
88 | { | |
89 | if (t->u.kernel.target->destroy) | |
1c524830 | 90 | t->u.kernel.target->destroy(t->u.kernel.target, t->data, |
1da177e4 LT |
91 | t->u.target_size - sizeof(*t)); |
92 | module_put(t->u.kernel.target->me); | |
93 | } | |
94 | ||
95 | static int | |
96 | tcf_ipt_release(struct tcf_ipt *p, int bind) | |
97 | { | |
98 | int ret = 0; | |
99 | if (p) { | |
100 | if (bind) | |
101 | p->bindcnt--; | |
102 | p->refcnt--; | |
103 | if (p->bindcnt <= 0 && p->refcnt <= 0) { | |
104 | ipt_destroy_target(p->t); | |
105 | kfree(p->tname); | |
106 | kfree(p->t); | |
107 | tcf_hash_destroy(p); | |
108 | ret = ACT_P_DELETED; | |
109 | } | |
110 | } | |
111 | return ret; | |
112 | } | |
113 | ||
114 | static int | |
115 | tcf_ipt_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a, | |
116 | int ovr, int bind) | |
117 | { | |
118 | struct rtattr *tb[TCA_IPT_MAX]; | |
119 | struct tcf_ipt *p; | |
120 | struct ipt_entry_target *td, *t; | |
121 | char *tname; | |
122 | int ret = 0, err; | |
123 | u32 hook = 0; | |
124 | u32 index = 0; | |
125 | ||
126 | if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0) | |
127 | return -EINVAL; | |
128 | ||
129 | if (tb[TCA_IPT_HOOK-1] == NULL || | |
130 | RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32)) | |
131 | return -EINVAL; | |
132 | if (tb[TCA_IPT_TARG-1] == NULL || | |
133 | RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t)) | |
134 | return -EINVAL; | |
135 | td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]); | |
136 | if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size) | |
137 | return -EINVAL; | |
138 | ||
139 | if (tb[TCA_IPT_INDEX-1] != NULL && | |
140 | RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32)) | |
141 | index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]); | |
142 | ||
143 | p = tcf_hash_check(index, a, ovr, bind); | |
144 | if (p == NULL) { | |
145 | p = tcf_hash_create(index, est, a, sizeof(*p), ovr, bind); | |
146 | if (p == NULL) | |
147 | return -ENOMEM; | |
148 | ret = ACT_P_CREATED; | |
149 | } else { | |
150 | if (!ovr) { | |
151 | tcf_ipt_release(p, bind); | |
152 | return -EEXIST; | |
153 | } | |
154 | } | |
155 | ||
156 | hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]); | |
157 | ||
158 | err = -ENOMEM; | |
159 | tname = kmalloc(IFNAMSIZ, GFP_KERNEL); | |
160 | if (tname == NULL) | |
161 | goto err1; | |
162 | if (tb[TCA_IPT_TABLE - 1] == NULL || | |
163 | rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ) | |
164 | strcpy(tname, "mangle"); | |
165 | ||
166 | t = kmalloc(td->u.target_size, GFP_KERNEL); | |
167 | if (t == NULL) | |
168 | goto err2; | |
169 | memcpy(t, td, td->u.target_size); | |
170 | ||
171 | if ((err = ipt_init_target(t, tname, hook)) < 0) | |
172 | goto err3; | |
173 | ||
174 | spin_lock_bh(&p->lock); | |
175 | if (ret != ACT_P_CREATED) { | |
176 | ipt_destroy_target(p->t); | |
177 | kfree(p->tname); | |
178 | kfree(p->t); | |
179 | } | |
180 | p->tname = tname; | |
181 | p->t = t; | |
182 | p->hook = hook; | |
183 | spin_unlock_bh(&p->lock); | |
184 | if (ret == ACT_P_CREATED) | |
185 | tcf_hash_insert(p); | |
186 | return ret; | |
187 | ||
188 | err3: | |
189 | kfree(t); | |
190 | err2: | |
191 | kfree(tname); | |
192 | err1: | |
193 | kfree(p); | |
194 | return err; | |
195 | } | |
196 | ||
197 | static int | |
198 | tcf_ipt_cleanup(struct tc_action *a, int bind) | |
199 | { | |
200 | struct tcf_ipt *p = PRIV(a, ipt); | |
201 | return tcf_ipt_release(p, bind); | |
202 | } | |
203 | ||
204 | static int | |
f43c5a0d | 205 | tcf_ipt(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) |
1da177e4 LT |
206 | { |
207 | int ret = 0, result = 0; | |
208 | struct tcf_ipt *p = PRIV(a, ipt); | |
1da177e4 LT |
209 | |
210 | if (skb_cloned(skb)) { | |
211 | if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) | |
212 | return TC_ACT_UNSPEC; | |
213 | } | |
214 | ||
215 | spin_lock(&p->lock); | |
216 | ||
217 | p->tm.lastuse = jiffies; | |
218 | p->bstats.bytes += skb->len; | |
219 | p->bstats.packets++; | |
220 | ||
221 | /* yes, we have to worry about both in and out dev | |
222 | worry later - danger - this API seems to have changed | |
223 | from earlier kernels */ | |
224 | ||
f43c5a0d PM |
225 | /* iptables targets take a double skb pointer in case the skb |
226 | * needs to be replaced. We don't own the skb, so this must not | |
227 | * happen. The pskb_expand_head above should make sure of this */ | |
1c524830 PM |
228 | ret = p->t->u.kernel.target->target(&skb, skb->dev, NULL, p->hook, |
229 | p->t->u.kernel.target, p->t->data, | |
230 | NULL); | |
1da177e4 LT |
231 | switch (ret) { |
232 | case NF_ACCEPT: | |
233 | result = TC_ACT_OK; | |
234 | break; | |
235 | case NF_DROP: | |
236 | result = TC_ACT_SHOT; | |
237 | p->qstats.drops++; | |
238 | break; | |
239 | case IPT_CONTINUE: | |
240 | result = TC_ACT_PIPE; | |
241 | break; | |
242 | default: | |
243 | if (net_ratelimit()) | |
244 | printk("Bogus netfilter code %d assume ACCEPT\n", ret); | |
245 | result = TC_POLICE_OK; | |
246 | break; | |
247 | } | |
248 | spin_unlock(&p->lock); | |
249 | return result; | |
250 | ||
251 | } | |
252 | ||
253 | static int | |
254 | tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) | |
255 | { | |
256 | struct ipt_entry_target *t; | |
257 | struct tcf_t tm; | |
258 | struct tc_cnt c; | |
259 | unsigned char *b = skb->tail; | |
260 | struct tcf_ipt *p = PRIV(a, ipt); | |
261 | ||
262 | /* for simple targets kernel size == user size | |
263 | ** user name = target name | |
264 | ** for foolproof you need to not assume this | |
265 | */ | |
266 | ||
267 | t = kmalloc(p->t->u.user.target_size, GFP_ATOMIC); | |
268 | if (t == NULL) | |
269 | goto rtattr_failure; | |
270 | ||
271 | c.bindcnt = p->bindcnt - bind; | |
272 | c.refcnt = p->refcnt - ref; | |
273 | memcpy(t, p->t, p->t->u.user.target_size); | |
274 | strcpy(t->u.user.name, p->t->u.kernel.target->name); | |
275 | ||
276 | DPRINTK("\ttcf_ipt_dump tablename %s length %d\n", p->tname, | |
277 | strlen(p->tname)); | |
278 | DPRINTK("\tdump target name %s size %d size user %d " | |
279 | "data[0] %x data[1] %x\n", p->t->u.kernel.target->name, | |
280 | p->t->u.target_size, p->t->u.user.target_size, | |
281 | p->t->data[0], p->t->data[1]); | |
282 | RTA_PUT(skb, TCA_IPT_TARG, p->t->u.user.target_size, t); | |
283 | RTA_PUT(skb, TCA_IPT_INDEX, 4, &p->index); | |
284 | RTA_PUT(skb, TCA_IPT_HOOK, 4, &p->hook); | |
285 | RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c); | |
286 | RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, p->tname); | |
287 | tm.install = jiffies_to_clock_t(jiffies - p->tm.install); | |
288 | tm.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse); | |
289 | tm.expires = jiffies_to_clock_t(p->tm.expires); | |
290 | RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm); | |
291 | kfree(t); | |
292 | return skb->len; | |
293 | ||
294 | rtattr_failure: | |
295 | skb_trim(skb, b - skb->data); | |
296 | kfree(t); | |
297 | return -1; | |
298 | } | |
299 | ||
300 | static struct tc_action_ops act_ipt_ops = { | |
301 | .kind = "ipt", | |
302 | .type = TCA_ACT_IPT, | |
303 | .capab = TCA_CAP_NONE, | |
304 | .owner = THIS_MODULE, | |
305 | .act = tcf_ipt, | |
306 | .dump = tcf_ipt_dump, | |
307 | .cleanup = tcf_ipt_cleanup, | |
308 | .lookup = tcf_hash_search, | |
309 | .init = tcf_ipt_init, | |
310 | .walk = tcf_generic_walker | |
311 | }; | |
312 | ||
313 | MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); | |
314 | MODULE_DESCRIPTION("Iptables target actions"); | |
315 | MODULE_LICENSE("GPL"); | |
316 | ||
317 | static int __init | |
318 | ipt_init_module(void) | |
319 | { | |
320 | return tcf_register_action(&act_ipt_ops); | |
321 | } | |
322 | ||
323 | static void __exit | |
324 | ipt_cleanup_module(void) | |
325 | { | |
326 | tcf_unregister_action(&act_ipt_ops); | |
327 | } | |
328 | ||
329 | module_init(ipt_init_module); | |
330 | module_exit(ipt_cleanup_module); |