don't expose I_NEW inodes via dentry->d_inode
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / nf_queue.c
CommitLineData
f6ebe77f 1#include <linux/kernel.h>
5a0e3ad6 2#include <linux/slab.h>
f6ebe77f
HW
3#include <linux/init.h>
4#include <linux/module.h>
5#include <linux/proc_fs.h>
6#include <linux/skbuff.h>
7#include <linux/netfilter.h>
bbd86b9f 8#include <linux/seq_file.h>
7a11b984 9#include <linux/rcupdate.h>
f6ebe77f 10#include <net/protocol.h>
c01cd429 11#include <net/netfilter/nf_queue.h>
7fee226a 12#include <net/dst.h>
f6ebe77f
HW
13
14#include "nf_internals.h"
15
601e68e1 16/*
f6ebe77f
HW
17 * A queue handler may be registered for each protocol. Each is protected by
18 * long term mutex. The handler must provide an an outfn() to accept packets
19 * for queueing and must reinject all packets it receives, no matter what.
20 */
0906a372 21static const struct nf_queue_handler __rcu *queue_handler[NFPROTO_NUMPROTO] __read_mostly;
f6ebe77f 22
585426fd 23static DEFINE_MUTEX(queue_handler_mutex);
f6ebe77f 24
d72367b6
HW
25/* return EBUSY when somebody else is registered, return EEXIST if the
26 * same handler is registered, return 0 in case of success. */
76108cea 27int nf_register_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
601e68e1 28{
f6ebe77f 29 int ret;
0e60ebe0 30 const struct nf_queue_handler *old;
f6ebe77f 31
7e9c6eeb 32 if (pf >= ARRAY_SIZE(queue_handler))
f6ebe77f
HW
33 return -EINVAL;
34
585426fd 35 mutex_lock(&queue_handler_mutex);
0e60ebe0
ED
36 old = rcu_dereference_protected(queue_handler[pf],
37 lockdep_is_held(&queue_handler_mutex));
38 if (old == qh)
d72367b6 39 ret = -EEXIST;
0e60ebe0 40 else if (old)
f6ebe77f
HW
41 ret = -EBUSY;
42 else {
cf778b00 43 rcu_assign_pointer(queue_handler[pf], qh);
f6ebe77f
HW
44 ret = 0;
45 }
585426fd 46 mutex_unlock(&queue_handler_mutex);
f6ebe77f
HW
47
48 return ret;
49}
50EXPORT_SYMBOL(nf_register_queue_handler);
51
52/* The caller must flush their queue before this */
76108cea 53int nf_unregister_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
f6ebe77f 54{
0e60ebe0
ED
55 const struct nf_queue_handler *old;
56
7e9c6eeb 57 if (pf >= ARRAY_SIZE(queue_handler))
f6ebe77f
HW
58 return -EINVAL;
59
585426fd 60 mutex_lock(&queue_handler_mutex);
0e60ebe0
ED
61 old = rcu_dereference_protected(queue_handler[pf],
62 lockdep_is_held(&queue_handler_mutex));
63 if (old && old != qh) {
585426fd 64 mutex_unlock(&queue_handler_mutex);
ce7663d8
YK
65 return -EINVAL;
66 }
67
a9b3cd7f 68 RCU_INIT_POINTER(queue_handler[pf], NULL);
585426fd
YK
69 mutex_unlock(&queue_handler_mutex);
70
71 synchronize_rcu();
601e68e1 72
f6ebe77f
HW
73 return 0;
74}
75EXPORT_SYMBOL(nf_unregister_queue_handler);
76
e3ac5298 77void nf_unregister_queue_handlers(const struct nf_queue_handler *qh)
f6ebe77f 78{
76108cea 79 u_int8_t pf;
f6ebe77f 80
585426fd 81 mutex_lock(&queue_handler_mutex);
7e9c6eeb 82 for (pf = 0; pf < ARRAY_SIZE(queue_handler); pf++) {
0e60ebe0
ED
83 if (rcu_dereference_protected(
84 queue_handler[pf],
85 lockdep_is_held(&queue_handler_mutex)
86 ) == qh)
a9b3cd7f 87 RCU_INIT_POINTER(queue_handler[pf], NULL);
f6ebe77f 88 }
585426fd
YK
89 mutex_unlock(&queue_handler_mutex);
90
91 synchronize_rcu();
f6ebe77f
HW
92}
93EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
94
daaa8be2
PM
95static void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
96{
97 /* Release those devices we held, or Alexey will kill me. */
98 if (entry->indev)
99 dev_put(entry->indev);
100 if (entry->outdev)
101 dev_put(entry->outdev);
102#ifdef CONFIG_BRIDGE_NETFILTER
103 if (entry->skb->nf_bridge) {
104 struct nf_bridge_info *nf_bridge = entry->skb->nf_bridge;
105
106 if (nf_bridge->physindev)
107 dev_put(nf_bridge->physindev);
108 if (nf_bridge->physoutdev)
109 dev_put(nf_bridge->physoutdev);
110 }
111#endif
112 /* Drop reference to owner of hook which queued us. */
113 module_put(entry->elem->owner);
114}
115
601e68e1
YH
116/*
117 * Any packet that leaves via this function must come back
f6ebe77f
HW
118 * through nf_reinject().
119 */
394f545d
PM
120static int __nf_queue(struct sk_buff *skb,
121 struct list_head *elem,
76108cea 122 u_int8_t pf, unsigned int hook,
394f545d
PM
123 struct net_device *indev,
124 struct net_device *outdev,
125 int (*okfn)(struct sk_buff *),
126 unsigned int queuenum)
f6ebe77f 127{
f1585086 128 int status = -ENOENT;
daaa8be2 129 struct nf_queue_entry *entry = NULL;
f6ebe77f 130#ifdef CONFIG_BRIDGE_NETFILTER
daaa8be2
PM
131 struct net_device *physindev;
132 struct net_device *physoutdev;
f6ebe77f 133#endif
1e796fda 134 const struct nf_afinfo *afinfo;
e3ac5298 135 const struct nf_queue_handler *qh;
f6ebe77f 136
25985edc 137 /* QUEUE == DROP if no one is waiting, to be safe. */
585426fd
YK
138 rcu_read_lock();
139
140 qh = rcu_dereference(queue_handler[pf]);
94b27cc3
FW
141 if (!qh) {
142 status = -ESRCH;
daaa8be2 143 goto err_unlock;
94b27cc3 144 }
f6ebe77f 145
bce8032e 146 afinfo = nf_get_afinfo(pf);
daaa8be2
PM
147 if (!afinfo)
148 goto err_unlock;
bce8032e 149
02f014d8 150 entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);
f1585086
FW
151 if (!entry) {
152 status = -ENOMEM;
daaa8be2 153 goto err_unlock;
f1585086 154 }
f6ebe77f 155
02f014d8
PM
156 *entry = (struct nf_queue_entry) {
157 .skb = skb,
158 .elem = list_entry(elem, struct nf_hook_ops, list),
159 .pf = pf,
160 .hook = hook,
161 .indev = indev,
162 .outdev = outdev,
163 .okfn = okfn,
164 };
f6ebe77f
HW
165
166 /* If it's going away, ignore hook. */
02f014d8 167 if (!try_module_get(entry->elem->owner)) {
06cdb634
FW
168 status = -ECANCELED;
169 goto err_unlock;
f6ebe77f 170 }
f6ebe77f 171 /* Bump dev refs so they don't vanish while packet is out */
8b1cf0db
PM
172 if (indev)
173 dev_hold(indev);
174 if (outdev)
175 dev_hold(outdev);
f6ebe77f 176#ifdef CONFIG_BRIDGE_NETFILTER
394f545d
PM
177 if (skb->nf_bridge) {
178 physindev = skb->nf_bridge->physindev;
8b1cf0db
PM
179 if (physindev)
180 dev_hold(physindev);
394f545d 181 physoutdev = skb->nf_bridge->physoutdev;
8b1cf0db
PM
182 if (physoutdev)
183 dev_hold(physoutdev);
f6ebe77f
HW
184 }
185#endif
7fee226a 186 skb_dst_force(skb);
02f014d8
PM
187 afinfo->saveroute(skb, entry);
188 status = qh->outfn(entry, queuenum);
f6ebe77f 189
585426fd 190 rcu_read_unlock();
f6ebe77f
HW
191
192 if (status < 0) {
daaa8be2
PM
193 nf_queue_entry_release_refs(entry);
194 goto err;
f6ebe77f
HW
195 }
196
f1585086 197 return 0;
daaa8be2
PM
198
199err_unlock:
200 rcu_read_unlock();
201err:
daaa8be2 202 kfree(entry);
f1585086 203 return status;
f6ebe77f
HW
204}
205
a8db7b2d
FW
206#ifdef CONFIG_BRIDGE_NETFILTER
207/* When called from bridge netfilter, skb->data must point to MAC header
208 * before calling skb_gso_segment(). Else, original MAC header is lost
209 * and segmented skbs will be sent to wrong destination.
210 */
211static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
212{
213 if (skb->nf_bridge)
214 __skb_push(skb, skb->network_header - skb->mac_header);
215}
216
217static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
218{
219 if (skb->nf_bridge)
220 __skb_pull(skb, skb->network_header - skb->mac_header);
221}
222#else
223#define nf_bridge_adjust_skb_data(s) do {} while (0)
224#define nf_bridge_adjust_segmented_data(s) do {} while (0)
225#endif
226
394f545d
PM
227int nf_queue(struct sk_buff *skb,
228 struct list_head *elem,
76108cea 229 u_int8_t pf, unsigned int hook,
394f545d
PM
230 struct net_device *indev,
231 struct net_device *outdev,
232 int (*okfn)(struct sk_buff *),
233 unsigned int queuenum)
234{
235 struct sk_buff *segs;
a8db7b2d 236 int err = -EINVAL;
f1585086 237 unsigned int queued;
394f545d
PM
238
239 if (!skb_is_gso(skb))
240 return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
241 queuenum);
242
243 switch (pf) {
4b1e27e9 244 case NFPROTO_IPV4:
394f545d
PM
245 skb->protocol = htons(ETH_P_IP);
246 break;
4b1e27e9 247 case NFPROTO_IPV6:
394f545d
PM
248 skb->protocol = htons(ETH_P_IPV6);
249 break;
250 }
251
a8db7b2d 252 nf_bridge_adjust_skb_data(skb);
394f545d 253 segs = skb_gso_segment(skb, 0);
f1585086
FW
254 /* Does not use PTR_ERR to limit the number of error codes that can be
255 * returned by nf_queue. For instance, callers rely on -ECANCELED to mean
256 * 'ignore this hook'.
257 */
801678c5 258 if (IS_ERR(segs))
a8db7b2d 259 goto out_err;
f1585086
FW
260 queued = 0;
261 err = 0;
394f545d
PM
262 do {
263 struct sk_buff *nskb = segs->next;
264
265 segs->next = NULL;
a8db7b2d
FW
266 if (err == 0) {
267 nf_bridge_adjust_segmented_data(segs);
f1585086
FW
268 err = __nf_queue(segs, elem, pf, hook, indev,
269 outdev, okfn, queuenum);
a8db7b2d 270 }
f1585086
FW
271 if (err == 0)
272 queued++;
273 else
394f545d
PM
274 kfree_skb(segs);
275 segs = nskb;
276 } while (segs);
f1585086 277
a8db7b2d 278 if (queued) {
06cdb634 279 kfree_skb(skb);
a8db7b2d
FW
280 return 0;
281 }
282 out_err:
283 nf_bridge_adjust_segmented_data(skb);
f1585086 284 return err;
394f545d
PM
285}
286
02f014d8 287void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
f6ebe77f 288{
02f014d8
PM
289 struct sk_buff *skb = entry->skb;
290 struct list_head *elem = &entry->elem->list;
1e796fda 291 const struct nf_afinfo *afinfo;
f1585086 292 int err;
f6ebe77f
HW
293
294 rcu_read_lock();
295
daaa8be2 296 nf_queue_entry_release_refs(entry);
f6ebe77f 297
f6ebe77f
HW
298 /* Continue traversal iff userspace said ok... */
299 if (verdict == NF_REPEAT) {
300 elem = elem->prev;
301 verdict = NF_ACCEPT;
302 }
303
7a11b984 304 if (verdict == NF_ACCEPT) {
02f014d8
PM
305 afinfo = nf_get_afinfo(entry->pf);
306 if (!afinfo || afinfo->reroute(skb, entry) < 0)
7a11b984
PM
307 verdict = NF_DROP;
308 }
309
f6ebe77f
HW
310 if (verdict == NF_ACCEPT) {
311 next_hook:
02f014d8
PM
312 verdict = nf_iterate(&nf_hooks[entry->pf][entry->hook],
313 skb, entry->hook,
314 entry->indev, entry->outdev, &elem,
315 entry->okfn, INT_MIN);
f6ebe77f
HW
316 }
317
318 switch (verdict & NF_VERDICT_MASK) {
319 case NF_ACCEPT:
3bc38712 320 case NF_STOP:
4b3d15ef 321 local_bh_disable();
02f014d8 322 entry->okfn(skb);
4b3d15ef 323 local_bh_enable();
f6ebe77f 324 break;
f6ebe77f 325 case NF_QUEUE:
f1585086
FW
326 err = __nf_queue(skb, elem, entry->pf, entry->hook,
327 entry->indev, entry->outdev, entry->okfn,
f615df76 328 verdict >> NF_VERDICT_QBITS);
06cdb634
FW
329 if (err < 0) {
330 if (err == -ECANCELED)
331 goto next_hook;
94b27cc3
FW
332 if (err == -ESRCH &&
333 (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS))
334 goto next_hook;
06cdb634
FW
335 kfree_skb(skb);
336 }
f6ebe77f 337 break;
64507fdb 338 case NF_STOLEN:
fad54440 339 break;
3bc38712
PM
340 default:
341 kfree_skb(skb);
f6ebe77f
HW
342 }
343 rcu_read_unlock();
02f014d8 344 kfree(entry);
f6ebe77f
HW
345}
346EXPORT_SYMBOL(nf_reinject);
347
bbd86b9f
HW
348#ifdef CONFIG_PROC_FS
349static void *seq_start(struct seq_file *seq, loff_t *pos)
350{
7e9c6eeb 351 if (*pos >= ARRAY_SIZE(queue_handler))
bbd86b9f
HW
352 return NULL;
353
354 return pos;
355}
356
357static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
358{
359 (*pos)++;
360
7e9c6eeb 361 if (*pos >= ARRAY_SIZE(queue_handler))
bbd86b9f
HW
362 return NULL;
363
364 return pos;
365}
366
367static void seq_stop(struct seq_file *s, void *v)
368{
369
370}
371
372static int seq_show(struct seq_file *s, void *v)
373{
374 int ret;
375 loff_t *pos = v;
e3ac5298 376 const struct nf_queue_handler *qh;
bbd86b9f 377
585426fd
YK
378 rcu_read_lock();
379 qh = rcu_dereference(queue_handler[*pos]);
bbd86b9f
HW
380 if (!qh)
381 ret = seq_printf(s, "%2lld NONE\n", *pos);
382 else
383 ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
585426fd 384 rcu_read_unlock();
bbd86b9f
HW
385
386 return ret;
387}
388
56b3d975 389static const struct seq_operations nfqueue_seq_ops = {
bbd86b9f
HW
390 .start = seq_start,
391 .next = seq_next,
392 .stop = seq_stop,
393 .show = seq_show,
394};
395
396static int nfqueue_open(struct inode *inode, struct file *file)
397{
398 return seq_open(file, &nfqueue_seq_ops);
399}
400
da7071d7 401static const struct file_operations nfqueue_file_ops = {
bbd86b9f
HW
402 .owner = THIS_MODULE,
403 .open = nfqueue_open,
404 .read = seq_read,
405 .llseek = seq_lseek,
406 .release = seq_release,
407};
408#endif /* PROC_FS */
409
410
f6ebe77f
HW
411int __init netfilter_queue_init(void)
412{
bbd86b9f 413#ifdef CONFIG_PROC_FS
8eeee8b1
DL
414 if (!proc_create("nf_queue", S_IRUGO,
415 proc_net_netfilter, &nfqueue_file_ops))
bbd86b9f 416 return -1;
bbd86b9f 417#endif
f6ebe77f
HW
418 return 0;
419}
420