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Commit | Line | Data |
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f229f6ce PM |
1 | /* |
2 | * Rusty Russell (C)2000 -- This code is GPL. | |
3 | * Patrick McHardy (c) 2006-2012 | |
4 | */ | |
5 | ||
f6ebe77f | 6 | #include <linux/kernel.h> |
5a0e3ad6 | 7 | #include <linux/slab.h> |
f6ebe77f HW |
8 | #include <linux/init.h> |
9 | #include <linux/module.h> | |
10 | #include <linux/proc_fs.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/netfilter.h> | |
bbd86b9f | 13 | #include <linux/seq_file.h> |
7a11b984 | 14 | #include <linux/rcupdate.h> |
f6ebe77f | 15 | #include <net/protocol.h> |
c01cd429 | 16 | #include <net/netfilter/nf_queue.h> |
7fee226a | 17 | #include <net/dst.h> |
f6ebe77f HW |
18 | |
19 | #include "nf_internals.h" | |
20 | ||
601e68e1 | 21 | /* |
0360ae41 FW |
22 | * Hook for nfnetlink_queue to register its queue handler. |
23 | * We do this so that most of the NFQUEUE code can be modular. | |
24 | * | |
25 | * Once the queue is registered it must reinject all packets it | |
26 | * receives, no matter what. | |
f6ebe77f | 27 | */ |
0360ae41 | 28 | static const struct nf_queue_handler __rcu *queue_handler __read_mostly; |
f6ebe77f | 29 | |
d72367b6 HW |
30 | /* return EBUSY when somebody else is registered, return EEXIST if the |
31 | * same handler is registered, return 0 in case of success. */ | |
0360ae41 | 32 | void nf_register_queue_handler(const struct nf_queue_handler *qh) |
601e68e1 | 33 | { |
0360ae41 FW |
34 | /* should never happen, we only have one queueing backend in kernel */ |
35 | WARN_ON(rcu_access_pointer(queue_handler)); | |
36 | rcu_assign_pointer(queue_handler, qh); | |
f6ebe77f HW |
37 | } |
38 | EXPORT_SYMBOL(nf_register_queue_handler); | |
39 | ||
40 | /* The caller must flush their queue before this */ | |
0360ae41 | 41 | void nf_unregister_queue_handler(void) |
f6ebe77f | 42 | { |
0360ae41 | 43 | RCU_INIT_POINTER(queue_handler, NULL); |
585426fd | 44 | synchronize_rcu(); |
f6ebe77f HW |
45 | } |
46 | EXPORT_SYMBOL(nf_unregister_queue_handler); | |
47 | ||
a5fedd43 | 48 | void nf_queue_entry_release_refs(struct nf_queue_entry *entry) |
daaa8be2 PM |
49 | { |
50 | /* Release those devices we held, or Alexey will kill me. */ | |
51 | if (entry->indev) | |
52 | dev_put(entry->indev); | |
53 | if (entry->outdev) | |
54 | dev_put(entry->outdev); | |
55 | #ifdef CONFIG_BRIDGE_NETFILTER | |
56 | if (entry->skb->nf_bridge) { | |
57 | struct nf_bridge_info *nf_bridge = entry->skb->nf_bridge; | |
58 | ||
59 | if (nf_bridge->physindev) | |
60 | dev_put(nf_bridge->physindev); | |
61 | if (nf_bridge->physoutdev) | |
62 | dev_put(nf_bridge->physoutdev); | |
63 | } | |
64 | #endif | |
65 | /* Drop reference to owner of hook which queued us. */ | |
66 | module_put(entry->elem->owner); | |
67 | } | |
a5fedd43 | 68 | EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs); |
daaa8be2 | 69 | |
4bd60443 | 70 | /* Bump dev refs so they don't vanish while packet is out */ |
a5fedd43 | 71 | bool nf_queue_entry_get_refs(struct nf_queue_entry *entry) |
4bd60443 FW |
72 | { |
73 | if (!try_module_get(entry->elem->owner)) | |
74 | return false; | |
75 | ||
76 | if (entry->indev) | |
77 | dev_hold(entry->indev); | |
78 | if (entry->outdev) | |
79 | dev_hold(entry->outdev); | |
80 | #ifdef CONFIG_BRIDGE_NETFILTER | |
81 | if (entry->skb->nf_bridge) { | |
82 | struct nf_bridge_info *nf_bridge = entry->skb->nf_bridge; | |
83 | struct net_device *physdev; | |
84 | ||
85 | physdev = nf_bridge->physindev; | |
86 | if (physdev) | |
87 | dev_hold(physdev); | |
88 | physdev = nf_bridge->physoutdev; | |
89 | if (physdev) | |
90 | dev_hold(physdev); | |
91 | } | |
92 | #endif | |
93 | ||
94 | return true; | |
95 | } | |
a5fedd43 | 96 | EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs); |
4bd60443 | 97 | |
601e68e1 YH |
98 | /* |
99 | * Any packet that leaves via this function must come back | |
f6ebe77f HW |
100 | * through nf_reinject(). |
101 | */ | |
a5fedd43 | 102 | int nf_queue(struct sk_buff *skb, |
1c15b677 | 103 | struct nf_hook_ops *elem, |
76108cea | 104 | u_int8_t pf, unsigned int hook, |
394f545d PM |
105 | struct net_device *indev, |
106 | struct net_device *outdev, | |
107 | int (*okfn)(struct sk_buff *), | |
108 | unsigned int queuenum) | |
f6ebe77f | 109 | { |
f1585086 | 110 | int status = -ENOENT; |
daaa8be2 | 111 | struct nf_queue_entry *entry = NULL; |
1e796fda | 112 | const struct nf_afinfo *afinfo; |
e3ac5298 | 113 | const struct nf_queue_handler *qh; |
f6ebe77f | 114 | |
25985edc | 115 | /* QUEUE == DROP if no one is waiting, to be safe. */ |
585426fd YK |
116 | rcu_read_lock(); |
117 | ||
0360ae41 | 118 | qh = rcu_dereference(queue_handler); |
94b27cc3 FW |
119 | if (!qh) { |
120 | status = -ESRCH; | |
daaa8be2 | 121 | goto err_unlock; |
94b27cc3 | 122 | } |
f6ebe77f | 123 | |
bce8032e | 124 | afinfo = nf_get_afinfo(pf); |
daaa8be2 PM |
125 | if (!afinfo) |
126 | goto err_unlock; | |
bce8032e | 127 | |
02f014d8 | 128 | entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC); |
f1585086 FW |
129 | if (!entry) { |
130 | status = -ENOMEM; | |
daaa8be2 | 131 | goto err_unlock; |
f1585086 | 132 | } |
f6ebe77f | 133 | |
02f014d8 PM |
134 | *entry = (struct nf_queue_entry) { |
135 | .skb = skb, | |
1c15b677 | 136 | .elem = elem, |
02f014d8 PM |
137 | .pf = pf, |
138 | .hook = hook, | |
139 | .indev = indev, | |
140 | .outdev = outdev, | |
141 | .okfn = okfn, | |
a5fedd43 | 142 | .size = sizeof(*entry) + afinfo->route_key_size, |
02f014d8 | 143 | }; |
f6ebe77f | 144 | |
4bd60443 | 145 | if (!nf_queue_entry_get_refs(entry)) { |
06cdb634 FW |
146 | status = -ECANCELED; |
147 | goto err_unlock; | |
f6ebe77f | 148 | } |
7fee226a | 149 | skb_dst_force(skb); |
02f014d8 PM |
150 | afinfo->saveroute(skb, entry); |
151 | status = qh->outfn(entry, queuenum); | |
f6ebe77f | 152 | |
585426fd | 153 | rcu_read_unlock(); |
f6ebe77f HW |
154 | |
155 | if (status < 0) { | |
daaa8be2 PM |
156 | nf_queue_entry_release_refs(entry); |
157 | goto err; | |
f6ebe77f HW |
158 | } |
159 | ||
f1585086 | 160 | return 0; |
daaa8be2 PM |
161 | |
162 | err_unlock: | |
163 | rcu_read_unlock(); | |
164 | err: | |
daaa8be2 | 165 | kfree(entry); |
f1585086 | 166 | return status; |
f6ebe77f HW |
167 | } |
168 | ||
02f014d8 | 169 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 170 | { |
02f014d8 | 171 | struct sk_buff *skb = entry->skb; |
2a6decfd | 172 | struct nf_hook_ops *elem = entry->elem; |
1e796fda | 173 | const struct nf_afinfo *afinfo; |
f1585086 | 174 | int err; |
f6ebe77f HW |
175 | |
176 | rcu_read_lock(); | |
177 | ||
daaa8be2 | 178 | nf_queue_entry_release_refs(entry); |
f6ebe77f | 179 | |
f6ebe77f HW |
180 | /* Continue traversal iff userspace said ok... */ |
181 | if (verdict == NF_REPEAT) { | |
2a6decfd | 182 | elem = list_entry(elem->list.prev, struct nf_hook_ops, list); |
f6ebe77f HW |
183 | verdict = NF_ACCEPT; |
184 | } | |
185 | ||
7a11b984 | 186 | if (verdict == NF_ACCEPT) { |
02f014d8 PM |
187 | afinfo = nf_get_afinfo(entry->pf); |
188 | if (!afinfo || afinfo->reroute(skb, entry) < 0) | |
7a11b984 PM |
189 | verdict = NF_DROP; |
190 | } | |
191 | ||
f6ebe77f HW |
192 | if (verdict == NF_ACCEPT) { |
193 | next_hook: | |
02f014d8 PM |
194 | verdict = nf_iterate(&nf_hooks[entry->pf][entry->hook], |
195 | skb, entry->hook, | |
196 | entry->indev, entry->outdev, &elem, | |
197 | entry->okfn, INT_MIN); | |
f6ebe77f HW |
198 | } |
199 | ||
200 | switch (verdict & NF_VERDICT_MASK) { | |
201 | case NF_ACCEPT: | |
3bc38712 | 202 | case NF_STOP: |
4b3d15ef | 203 | local_bh_disable(); |
02f014d8 | 204 | entry->okfn(skb); |
4b3d15ef | 205 | local_bh_enable(); |
f6ebe77f | 206 | break; |
f6ebe77f | 207 | case NF_QUEUE: |
a5fedd43 FW |
208 | err = nf_queue(skb, elem, entry->pf, entry->hook, |
209 | entry->indev, entry->outdev, entry->okfn, | |
210 | verdict >> NF_VERDICT_QBITS); | |
06cdb634 FW |
211 | if (err < 0) { |
212 | if (err == -ECANCELED) | |
213 | goto next_hook; | |
94b27cc3 FW |
214 | if (err == -ESRCH && |
215 | (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS)) | |
216 | goto next_hook; | |
06cdb634 FW |
217 | kfree_skb(skb); |
218 | } | |
f6ebe77f | 219 | break; |
64507fdb | 220 | case NF_STOLEN: |
fad54440 | 221 | break; |
3bc38712 PM |
222 | default: |
223 | kfree_skb(skb); | |
f6ebe77f HW |
224 | } |
225 | rcu_read_unlock(); | |
02f014d8 | 226 | kfree(entry); |
f6ebe77f HW |
227 | } |
228 | EXPORT_SYMBOL(nf_reinject); |