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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> | |
c737b7c4 | 13 | #include <linux/netfilter_bridge.h> |
bbd86b9f | 14 | #include <linux/seq_file.h> |
7a11b984 | 15 | #include <linux/rcupdate.h> |
f6ebe77f | 16 | #include <net/protocol.h> |
c01cd429 | 17 | #include <net/netfilter/nf_queue.h> |
7fee226a | 18 | #include <net/dst.h> |
f6ebe77f HW |
19 | |
20 | #include "nf_internals.h" | |
21 | ||
601e68e1 | 22 | /* |
0360ae41 FW |
23 | * Hook for nfnetlink_queue to register its queue handler. |
24 | * We do this so that most of the NFQUEUE code can be modular. | |
25 | * | |
26 | * Once the queue is registered it must reinject all packets it | |
27 | * receives, no matter what. | |
f6ebe77f | 28 | */ |
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. */ | |
dc3ee32e | 32 | void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh) |
601e68e1 | 33 | { |
0360ae41 | 34 | /* should never happen, we only have one queueing backend in kernel */ |
dc3ee32e EB |
35 | WARN_ON(rcu_access_pointer(net->nf.queue_handler)); |
36 | rcu_assign_pointer(net->nf.queue_handler, qh); | |
f6ebe77f HW |
37 | } |
38 | EXPORT_SYMBOL(nf_register_queue_handler); | |
39 | ||
40 | /* The caller must flush their queue before this */ | |
dc3ee32e | 41 | void nf_unregister_queue_handler(struct net *net) |
f6ebe77f | 42 | { |
dc3ee32e | 43 | RCU_INIT_POINTER(net->nf.queue_handler, NULL); |
f6ebe77f HW |
44 | } |
45 | EXPORT_SYMBOL(nf_unregister_queue_handler); | |
46 | ||
a5fedd43 | 47 | void nf_queue_entry_release_refs(struct nf_queue_entry *entry) |
daaa8be2 | 48 | { |
1d1de89b DM |
49 | struct nf_hook_state *state = &entry->state; |
50 | ||
daaa8be2 | 51 | /* Release those devices we held, or Alexey will kill me. */ |
1d1de89b DM |
52 | if (state->in) |
53 | dev_put(state->in); | |
54 | if (state->out) | |
55 | dev_put(state->out); | |
1c984f8a DM |
56 | if (state->sk) |
57 | sock_put(state->sk); | |
1109a90c | 58 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
daaa8be2 | 59 | if (entry->skb->nf_bridge) { |
c737b7c4 | 60 | struct net_device *physdev; |
daaa8be2 | 61 | |
c737b7c4 FW |
62 | physdev = nf_bridge_get_physindev(entry->skb); |
63 | if (physdev) | |
64 | dev_put(physdev); | |
65 | physdev = nf_bridge_get_physoutdev(entry->skb); | |
66 | if (physdev) | |
67 | dev_put(physdev); | |
daaa8be2 PM |
68 | } |
69 | #endif | |
daaa8be2 | 70 | } |
a5fedd43 | 71 | EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs); |
daaa8be2 | 72 | |
4bd60443 | 73 | /* Bump dev refs so they don't vanish while packet is out */ |
ed78d09d | 74 | void nf_queue_entry_get_refs(struct nf_queue_entry *entry) |
4bd60443 | 75 | { |
1d1de89b DM |
76 | struct nf_hook_state *state = &entry->state; |
77 | ||
1d1de89b DM |
78 | if (state->in) |
79 | dev_hold(state->in); | |
80 | if (state->out) | |
81 | dev_hold(state->out); | |
1c984f8a DM |
82 | if (state->sk) |
83 | sock_hold(state->sk); | |
1109a90c | 84 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
4bd60443 | 85 | if (entry->skb->nf_bridge) { |
4bd60443 FW |
86 | struct net_device *physdev; |
87 | ||
c737b7c4 | 88 | physdev = nf_bridge_get_physindev(entry->skb); |
4bd60443 FW |
89 | if (physdev) |
90 | dev_hold(physdev); | |
c737b7c4 | 91 | physdev = nf_bridge_get_physoutdev(entry->skb); |
4bd60443 FW |
92 | if (physdev) |
93 | dev_hold(physdev); | |
94 | } | |
95 | #endif | |
4bd60443 | 96 | } |
a5fedd43 | 97 | EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs); |
4bd60443 | 98 | |
039b40ee | 99 | unsigned int nf_queue_nf_hook_drop(struct net *net) |
8405a8ff EB |
100 | { |
101 | const struct nf_queue_handler *qh; | |
039b40ee | 102 | unsigned int count = 0; |
8405a8ff | 103 | |
8405a8ff | 104 | rcu_read_lock(); |
dc3ee32e | 105 | qh = rcu_dereference(net->nf.queue_handler); |
2385eb0c | 106 | if (qh) |
039b40ee | 107 | count = qh->nf_hook_drop(net); |
8405a8ff | 108 | rcu_read_unlock(); |
039b40ee FW |
109 | |
110 | return count; | |
8405a8ff | 111 | } |
e2a75007 | 112 | EXPORT_SYMBOL_GPL(nf_queue_nf_hook_drop); |
8405a8ff | 113 | |
7034b566 | 114 | static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state, |
960632ec AC |
115 | const struct nf_hook_entries *entries, |
116 | unsigned int index, unsigned int queuenum) | |
f6ebe77f | 117 | { |
f1585086 | 118 | int status = -ENOENT; |
daaa8be2 | 119 | struct nf_queue_entry *entry = NULL; |
1e796fda | 120 | const struct nf_afinfo *afinfo; |
e3ac5298 | 121 | const struct nf_queue_handler *qh; |
dc3ee32e | 122 | struct net *net = state->net; |
f6ebe77f | 123 | |
25985edc | 124 | /* QUEUE == DROP if no one is waiting, to be safe. */ |
dc3ee32e | 125 | qh = rcu_dereference(net->nf.queue_handler); |
94b27cc3 FW |
126 | if (!qh) { |
127 | status = -ESRCH; | |
81b4325e | 128 | goto err; |
94b27cc3 | 129 | } |
f6ebe77f | 130 | |
cfdfab31 | 131 | afinfo = nf_get_afinfo(state->pf); |
daaa8be2 | 132 | if (!afinfo) |
81b4325e | 133 | goto err; |
bce8032e | 134 | |
02f014d8 | 135 | entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC); |
f1585086 FW |
136 | if (!entry) { |
137 | status = -ENOMEM; | |
81b4325e | 138 | goto err; |
f1585086 | 139 | } |
f6ebe77f | 140 | |
faf4ba40 | 141 | if (skb_dst(skb) && !skb_dst_force(skb)) { |
0face484 FW |
142 | status = -ENETDOWN; |
143 | goto err; | |
144 | } | |
145 | ||
02f014d8 PM |
146 | *entry = (struct nf_queue_entry) { |
147 | .skb = skb, | |
1d1de89b | 148 | .state = *state, |
960632ec | 149 | .hook_index = index, |
a5fedd43 | 150 | .size = sizeof(*entry) + afinfo->route_key_size, |
02f014d8 | 151 | }; |
f6ebe77f | 152 | |
ed78d09d | 153 | nf_queue_entry_get_refs(entry); |
02f014d8 PM |
154 | afinfo->saveroute(skb, entry); |
155 | status = qh->outfn(entry, queuenum); | |
f6ebe77f | 156 | |
f6ebe77f | 157 | if (status < 0) { |
daaa8be2 PM |
158 | nf_queue_entry_release_refs(entry); |
159 | goto err; | |
f6ebe77f HW |
160 | } |
161 | ||
f1585086 | 162 | return 0; |
daaa8be2 | 163 | |
daaa8be2 | 164 | err: |
daaa8be2 | 165 | kfree(entry); |
f1585086 | 166 | return status; |
f6ebe77f HW |
167 | } |
168 | ||
7034b566 PNA |
169 | /* Packets leaving via this function must come back through nf_reinject(). */ |
170 | int nf_queue(struct sk_buff *skb, struct nf_hook_state *state, | |
960632ec AC |
171 | const struct nf_hook_entries *entries, unsigned int index, |
172 | unsigned int verdict) | |
7034b566 | 173 | { |
7034b566 PNA |
174 | int ret; |
175 | ||
960632ec | 176 | ret = __nf_queue(skb, state, entries, index, verdict >> NF_VERDICT_QBITS); |
7034b566 PNA |
177 | if (ret < 0) { |
178 | if (ret == -ESRCH && | |
960632ec | 179 | (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS)) |
7034b566 | 180 | return 1; |
7034b566 PNA |
181 | kfree_skb(skb); |
182 | } | |
183 | ||
184 | return 0; | |
185 | } | |
186 | ||
26dfab72 PNA |
187 | static unsigned int nf_iterate(struct sk_buff *skb, |
188 | struct nf_hook_state *state, | |
960632ec AC |
189 | const struct nf_hook_entries *hooks, |
190 | unsigned int *index) | |
26dfab72 | 191 | { |
960632ec AC |
192 | const struct nf_hook_entry *hook; |
193 | unsigned int verdict, i = *index; | |
26dfab72 | 194 | |
960632ec AC |
195 | while (i < hooks->num_hook_entries) { |
196 | hook = &hooks->hooks[i]; | |
26dfab72 | 197 | repeat: |
960632ec | 198 | verdict = nf_hook_entry_hookfn(hook, skb, state); |
26dfab72 | 199 | if (verdict != NF_ACCEPT) { |
128b510a | 200 | *index = i; |
26dfab72 PNA |
201 | if (verdict != NF_REPEAT) |
202 | return verdict; | |
203 | goto repeat; | |
204 | } | |
960632ec AC |
205 | i++; |
206 | } | |
26dfab72 | 207 | |
960632ec | 208 | *index = i; |
26dfab72 PNA |
209 | return NF_ACCEPT; |
210 | } | |
211 | ||
960632ec | 212 | /* Caller must hold rcu read-side lock */ |
02f014d8 | 213 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 214 | { |
960632ec AC |
215 | const struct nf_hook_entry *hook_entry; |
216 | const struct nf_hook_entries *hooks; | |
02f014d8 | 217 | struct sk_buff *skb = entry->skb; |
1e796fda | 218 | const struct nf_afinfo *afinfo; |
960632ec AC |
219 | const struct net *net; |
220 | unsigned int i; | |
f1585086 | 221 | int err; |
960632ec AC |
222 | u8 pf; |
223 | ||
224 | net = entry->state.net; | |
225 | pf = entry->state.pf; | |
226 | ||
227 | hooks = rcu_dereference(net->nf.hooks[pf][entry->state.hook]); | |
f6ebe77f | 228 | |
daaa8be2 | 229 | nf_queue_entry_release_refs(entry); |
f6ebe77f | 230 | |
960632ec AC |
231 | i = entry->hook_index; |
232 | if (WARN_ON_ONCE(i >= hooks->num_hook_entries)) { | |
233 | kfree_skb(skb); | |
234 | kfree(entry); | |
235 | return; | |
236 | } | |
237 | ||
238 | hook_entry = &hooks->hooks[i]; | |
239 | ||
f6ebe77f | 240 | /* Continue traversal iff userspace said ok... */ |
7ceebfe4 | 241 | if (verdict == NF_REPEAT) |
0aa8c57a | 242 | verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state); |
f6ebe77f | 243 | |
7a11b984 | 244 | if (verdict == NF_ACCEPT) { |
1d1de89b | 245 | afinfo = nf_get_afinfo(entry->state.pf); |
d815d90b | 246 | if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0) |
7a11b984 PM |
247 | verdict = NF_DROP; |
248 | } | |
249 | ||
f6ebe77f | 250 | if (verdict == NF_ACCEPT) { |
7034b566 | 251 | next_hook: |
960632ec AC |
252 | ++i; |
253 | verdict = nf_iterate(skb, &entry->state, hooks, &i); | |
f6ebe77f HW |
254 | } |
255 | ||
256 | switch (verdict & NF_VERDICT_MASK) { | |
257 | case NF_ACCEPT: | |
3bc38712 | 258 | case NF_STOP: |
4b3d15ef | 259 | local_bh_disable(); |
0c4b51f0 | 260 | entry->state.okfn(entry->state.net, entry->state.sk, skb); |
4b3d15ef | 261 | local_bh_enable(); |
f6ebe77f | 262 | break; |
f6ebe77f | 263 | case NF_QUEUE: |
960632ec AC |
264 | err = nf_queue(skb, &entry->state, hooks, i, verdict); |
265 | if (err == 1) | |
266 | goto next_hook; | |
f6ebe77f | 267 | break; |
64507fdb | 268 | case NF_STOLEN: |
fad54440 | 269 | break; |
3bc38712 PM |
270 | default: |
271 | kfree_skb(skb); | |
f6ebe77f | 272 | } |
81b4325e | 273 | |
02f014d8 | 274 | kfree(entry); |
f6ebe77f HW |
275 | } |
276 | EXPORT_SYMBOL(nf_reinject); |