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f6ebe77f HW |
1 | #include <linux/kernel.h> |
2 | #include <linux/init.h> | |
3 | #include <linux/module.h> | |
4 | #include <linux/proc_fs.h> | |
5 | #include <linux/skbuff.h> | |
6 | #include <linux/netfilter.h> | |
bbd86b9f | 7 | #include <linux/seq_file.h> |
7a11b984 | 8 | #include <linux/rcupdate.h> |
f6ebe77f | 9 | #include <net/protocol.h> |
c01cd429 | 10 | #include <net/netfilter/nf_queue.h> |
f6ebe77f HW |
11 | |
12 | #include "nf_internals.h" | |
13 | ||
601e68e1 | 14 | /* |
f6ebe77f HW |
15 | * A queue handler may be registered for each protocol. Each is protected by |
16 | * long term mutex. The handler must provide an an outfn() to accept packets | |
17 | * for queueing and must reinject all packets it receives, no matter what. | |
18 | */ | |
7e9c6eeb | 19 | static const struct nf_queue_handler *queue_handler[NFPROTO_NUMPROTO] __read_mostly; |
f6ebe77f | 20 | |
585426fd | 21 | static DEFINE_MUTEX(queue_handler_mutex); |
f6ebe77f | 22 | |
d72367b6 HW |
23 | /* return EBUSY when somebody else is registered, return EEXIST if the |
24 | * same handler is registered, return 0 in case of success. */ | |
76108cea | 25 | int nf_register_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh) |
601e68e1 | 26 | { |
f6ebe77f HW |
27 | int ret; |
28 | ||
7e9c6eeb | 29 | if (pf >= ARRAY_SIZE(queue_handler)) |
f6ebe77f HW |
30 | return -EINVAL; |
31 | ||
585426fd | 32 | mutex_lock(&queue_handler_mutex); |
d72367b6 HW |
33 | if (queue_handler[pf] == qh) |
34 | ret = -EEXIST; | |
35 | else if (queue_handler[pf]) | |
f6ebe77f HW |
36 | ret = -EBUSY; |
37 | else { | |
585426fd | 38 | rcu_assign_pointer(queue_handler[pf], qh); |
f6ebe77f HW |
39 | ret = 0; |
40 | } | |
585426fd | 41 | mutex_unlock(&queue_handler_mutex); |
f6ebe77f HW |
42 | |
43 | return ret; | |
44 | } | |
45 | EXPORT_SYMBOL(nf_register_queue_handler); | |
46 | ||
47 | /* The caller must flush their queue before this */ | |
76108cea | 48 | int nf_unregister_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh) |
f6ebe77f | 49 | { |
7e9c6eeb | 50 | if (pf >= ARRAY_SIZE(queue_handler)) |
f6ebe77f HW |
51 | return -EINVAL; |
52 | ||
585426fd | 53 | mutex_lock(&queue_handler_mutex); |
94be1a3f | 54 | if (queue_handler[pf] && queue_handler[pf] != qh) { |
585426fd | 55 | mutex_unlock(&queue_handler_mutex); |
ce7663d8 YK |
56 | return -EINVAL; |
57 | } | |
58 | ||
585426fd YK |
59 | rcu_assign_pointer(queue_handler[pf], NULL); |
60 | mutex_unlock(&queue_handler_mutex); | |
61 | ||
62 | synchronize_rcu(); | |
601e68e1 | 63 | |
f6ebe77f HW |
64 | return 0; |
65 | } | |
66 | EXPORT_SYMBOL(nf_unregister_queue_handler); | |
67 | ||
e3ac5298 | 68 | void nf_unregister_queue_handlers(const struct nf_queue_handler *qh) |
f6ebe77f | 69 | { |
76108cea | 70 | u_int8_t pf; |
f6ebe77f | 71 | |
585426fd | 72 | mutex_lock(&queue_handler_mutex); |
7e9c6eeb | 73 | for (pf = 0; pf < ARRAY_SIZE(queue_handler); pf++) { |
bbd86b9f | 74 | if (queue_handler[pf] == qh) |
585426fd | 75 | rcu_assign_pointer(queue_handler[pf], NULL); |
f6ebe77f | 76 | } |
585426fd YK |
77 | mutex_unlock(&queue_handler_mutex); |
78 | ||
79 | synchronize_rcu(); | |
f6ebe77f HW |
80 | } |
81 | EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers); | |
82 | ||
daaa8be2 PM |
83 | static void nf_queue_entry_release_refs(struct nf_queue_entry *entry) |
84 | { | |
85 | /* Release those devices we held, or Alexey will kill me. */ | |
86 | if (entry->indev) | |
87 | dev_put(entry->indev); | |
88 | if (entry->outdev) | |
89 | dev_put(entry->outdev); | |
90 | #ifdef CONFIG_BRIDGE_NETFILTER | |
91 | if (entry->skb->nf_bridge) { | |
92 | struct nf_bridge_info *nf_bridge = entry->skb->nf_bridge; | |
93 | ||
94 | if (nf_bridge->physindev) | |
95 | dev_put(nf_bridge->physindev); | |
96 | if (nf_bridge->physoutdev) | |
97 | dev_put(nf_bridge->physoutdev); | |
98 | } | |
99 | #endif | |
100 | /* Drop reference to owner of hook which queued us. */ | |
101 | module_put(entry->elem->owner); | |
102 | } | |
103 | ||
601e68e1 YH |
104 | /* |
105 | * Any packet that leaves via this function must come back | |
f6ebe77f HW |
106 | * through nf_reinject(). |
107 | */ | |
394f545d PM |
108 | static int __nf_queue(struct sk_buff *skb, |
109 | struct list_head *elem, | |
76108cea | 110 | u_int8_t pf, unsigned int hook, |
394f545d PM |
111 | struct net_device *indev, |
112 | struct net_device *outdev, | |
113 | int (*okfn)(struct sk_buff *), | |
114 | unsigned int queuenum) | |
f6ebe77f HW |
115 | { |
116 | int status; | |
daaa8be2 | 117 | struct nf_queue_entry *entry = NULL; |
f6ebe77f | 118 | #ifdef CONFIG_BRIDGE_NETFILTER |
daaa8be2 PM |
119 | struct net_device *physindev; |
120 | struct net_device *physoutdev; | |
f6ebe77f | 121 | #endif |
1e796fda | 122 | const struct nf_afinfo *afinfo; |
e3ac5298 | 123 | const struct nf_queue_handler *qh; |
f6ebe77f HW |
124 | |
125 | /* QUEUE == DROP if noone is waiting, to be safe. */ | |
585426fd YK |
126 | rcu_read_lock(); |
127 | ||
128 | qh = rcu_dereference(queue_handler[pf]); | |
daaa8be2 PM |
129 | if (!qh) |
130 | goto err_unlock; | |
f6ebe77f | 131 | |
bce8032e | 132 | afinfo = nf_get_afinfo(pf); |
daaa8be2 PM |
133 | if (!afinfo) |
134 | goto err_unlock; | |
bce8032e | 135 | |
02f014d8 | 136 | entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC); |
daaa8be2 PM |
137 | if (!entry) |
138 | goto err_unlock; | |
f6ebe77f | 139 | |
02f014d8 PM |
140 | *entry = (struct nf_queue_entry) { |
141 | .skb = skb, | |
142 | .elem = list_entry(elem, struct nf_hook_ops, list), | |
143 | .pf = pf, | |
144 | .hook = hook, | |
145 | .indev = indev, | |
146 | .outdev = outdev, | |
147 | .okfn = okfn, | |
148 | }; | |
f6ebe77f HW |
149 | |
150 | /* If it's going away, ignore hook. */ | |
02f014d8 | 151 | if (!try_module_get(entry->elem->owner)) { |
585426fd | 152 | rcu_read_unlock(); |
02f014d8 | 153 | kfree(entry); |
f6ebe77f HW |
154 | return 0; |
155 | } | |
156 | ||
157 | /* Bump dev refs so they don't vanish while packet is out */ | |
8b1cf0db PM |
158 | if (indev) |
159 | dev_hold(indev); | |
160 | if (outdev) | |
161 | dev_hold(outdev); | |
f6ebe77f | 162 | #ifdef CONFIG_BRIDGE_NETFILTER |
394f545d PM |
163 | if (skb->nf_bridge) { |
164 | physindev = skb->nf_bridge->physindev; | |
8b1cf0db PM |
165 | if (physindev) |
166 | dev_hold(physindev); | |
394f545d | 167 | physoutdev = skb->nf_bridge->physoutdev; |
8b1cf0db PM |
168 | if (physoutdev) |
169 | dev_hold(physoutdev); | |
f6ebe77f HW |
170 | } |
171 | #endif | |
02f014d8 PM |
172 | afinfo->saveroute(skb, entry); |
173 | status = qh->outfn(entry, queuenum); | |
f6ebe77f | 174 | |
585426fd | 175 | rcu_read_unlock(); |
f6ebe77f HW |
176 | |
177 | if (status < 0) { | |
daaa8be2 PM |
178 | nf_queue_entry_release_refs(entry); |
179 | goto err; | |
f6ebe77f HW |
180 | } |
181 | ||
182 | return 1; | |
daaa8be2 PM |
183 | |
184 | err_unlock: | |
185 | rcu_read_unlock(); | |
186 | err: | |
187 | kfree_skb(skb); | |
188 | kfree(entry); | |
189 | return 1; | |
f6ebe77f HW |
190 | } |
191 | ||
394f545d PM |
192 | int nf_queue(struct sk_buff *skb, |
193 | struct list_head *elem, | |
76108cea | 194 | u_int8_t pf, unsigned int hook, |
394f545d PM |
195 | struct net_device *indev, |
196 | struct net_device *outdev, | |
197 | int (*okfn)(struct sk_buff *), | |
198 | unsigned int queuenum) | |
199 | { | |
200 | struct sk_buff *segs; | |
201 | ||
202 | if (!skb_is_gso(skb)) | |
203 | return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn, | |
204 | queuenum); | |
205 | ||
206 | switch (pf) { | |
4b1e27e9 | 207 | case NFPROTO_IPV4: |
394f545d PM |
208 | skb->protocol = htons(ETH_P_IP); |
209 | break; | |
4b1e27e9 | 210 | case NFPROTO_IPV6: |
394f545d PM |
211 | skb->protocol = htons(ETH_P_IPV6); |
212 | break; | |
213 | } | |
214 | ||
215 | segs = skb_gso_segment(skb, 0); | |
216 | kfree_skb(skb); | |
801678c5 | 217 | if (IS_ERR(segs)) |
394f545d PM |
218 | return 1; |
219 | ||
220 | do { | |
221 | struct sk_buff *nskb = segs->next; | |
222 | ||
223 | segs->next = NULL; | |
224 | if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn, | |
225 | queuenum)) | |
226 | kfree_skb(segs); | |
227 | segs = nskb; | |
228 | } while (segs); | |
229 | return 1; | |
230 | } | |
231 | ||
02f014d8 | 232 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 233 | { |
02f014d8 PM |
234 | struct sk_buff *skb = entry->skb; |
235 | struct list_head *elem = &entry->elem->list; | |
1e796fda | 236 | const struct nf_afinfo *afinfo; |
f6ebe77f HW |
237 | |
238 | rcu_read_lock(); | |
239 | ||
daaa8be2 | 240 | nf_queue_entry_release_refs(entry); |
f6ebe77f | 241 | |
f6ebe77f HW |
242 | /* Continue traversal iff userspace said ok... */ |
243 | if (verdict == NF_REPEAT) { | |
244 | elem = elem->prev; | |
245 | verdict = NF_ACCEPT; | |
246 | } | |
247 | ||
7a11b984 | 248 | if (verdict == NF_ACCEPT) { |
02f014d8 PM |
249 | afinfo = nf_get_afinfo(entry->pf); |
250 | if (!afinfo || afinfo->reroute(skb, entry) < 0) | |
7a11b984 PM |
251 | verdict = NF_DROP; |
252 | } | |
253 | ||
f6ebe77f HW |
254 | if (verdict == NF_ACCEPT) { |
255 | next_hook: | |
02f014d8 PM |
256 | verdict = nf_iterate(&nf_hooks[entry->pf][entry->hook], |
257 | skb, entry->hook, | |
258 | entry->indev, entry->outdev, &elem, | |
259 | entry->okfn, INT_MIN); | |
f6ebe77f HW |
260 | } |
261 | ||
262 | switch (verdict & NF_VERDICT_MASK) { | |
263 | case NF_ACCEPT: | |
3bc38712 | 264 | case NF_STOP: |
4b3d15ef | 265 | local_bh_disable(); |
02f014d8 | 266 | entry->okfn(skb); |
4b3d15ef | 267 | local_bh_enable(); |
3bc38712 | 268 | case NF_STOLEN: |
f6ebe77f | 269 | break; |
f6ebe77f | 270 | case NF_QUEUE: |
02f014d8 PM |
271 | if (!__nf_queue(skb, elem, entry->pf, entry->hook, |
272 | entry->indev, entry->outdev, entry->okfn, | |
394f545d | 273 | verdict >> NF_VERDICT_BITS)) |
f6ebe77f HW |
274 | goto next_hook; |
275 | break; | |
3bc38712 PM |
276 | default: |
277 | kfree_skb(skb); | |
f6ebe77f HW |
278 | } |
279 | rcu_read_unlock(); | |
02f014d8 | 280 | kfree(entry); |
f6ebe77f HW |
281 | return; |
282 | } | |
283 | EXPORT_SYMBOL(nf_reinject); | |
284 | ||
bbd86b9f HW |
285 | #ifdef CONFIG_PROC_FS |
286 | static void *seq_start(struct seq_file *seq, loff_t *pos) | |
287 | { | |
7e9c6eeb | 288 | if (*pos >= ARRAY_SIZE(queue_handler)) |
bbd86b9f HW |
289 | return NULL; |
290 | ||
291 | return pos; | |
292 | } | |
293 | ||
294 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) | |
295 | { | |
296 | (*pos)++; | |
297 | ||
7e9c6eeb | 298 | if (*pos >= ARRAY_SIZE(queue_handler)) |
bbd86b9f HW |
299 | return NULL; |
300 | ||
301 | return pos; | |
302 | } | |
303 | ||
304 | static void seq_stop(struct seq_file *s, void *v) | |
305 | { | |
306 | ||
307 | } | |
308 | ||
309 | static int seq_show(struct seq_file *s, void *v) | |
310 | { | |
311 | int ret; | |
312 | loff_t *pos = v; | |
e3ac5298 | 313 | const struct nf_queue_handler *qh; |
bbd86b9f | 314 | |
585426fd YK |
315 | rcu_read_lock(); |
316 | qh = rcu_dereference(queue_handler[*pos]); | |
bbd86b9f HW |
317 | if (!qh) |
318 | ret = seq_printf(s, "%2lld NONE\n", *pos); | |
319 | else | |
320 | ret = seq_printf(s, "%2lld %s\n", *pos, qh->name); | |
585426fd | 321 | rcu_read_unlock(); |
bbd86b9f HW |
322 | |
323 | return ret; | |
324 | } | |
325 | ||
56b3d975 | 326 | static const struct seq_operations nfqueue_seq_ops = { |
bbd86b9f HW |
327 | .start = seq_start, |
328 | .next = seq_next, | |
329 | .stop = seq_stop, | |
330 | .show = seq_show, | |
331 | }; | |
332 | ||
333 | static int nfqueue_open(struct inode *inode, struct file *file) | |
334 | { | |
335 | return seq_open(file, &nfqueue_seq_ops); | |
336 | } | |
337 | ||
da7071d7 | 338 | static const struct file_operations nfqueue_file_ops = { |
bbd86b9f HW |
339 | .owner = THIS_MODULE, |
340 | .open = nfqueue_open, | |
341 | .read = seq_read, | |
342 | .llseek = seq_lseek, | |
343 | .release = seq_release, | |
344 | }; | |
345 | #endif /* PROC_FS */ | |
346 | ||
347 | ||
f6ebe77f HW |
348 | int __init netfilter_queue_init(void) |
349 | { | |
bbd86b9f | 350 | #ifdef CONFIG_PROC_FS |
8eeee8b1 DL |
351 | if (!proc_create("nf_queue", S_IRUGO, |
352 | proc_net_netfilter, &nfqueue_file_ops)) | |
bbd86b9f | 353 | return -1; |
bbd86b9f | 354 | #endif |
f6ebe77f HW |
355 | return 0; |
356 | } | |
357 |