Commit | Line | Data |
---|---|---|
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> | |
7db9a51e PNA |
13 | #include <linux/netfilter_ipv4.h> |
14 | #include <linux/netfilter_ipv6.h> | |
c737b7c4 | 15 | #include <linux/netfilter_bridge.h> |
bbd86b9f | 16 | #include <linux/seq_file.h> |
7a11b984 | 17 | #include <linux/rcupdate.h> |
f6ebe77f | 18 | #include <net/protocol.h> |
c01cd429 | 19 | #include <net/netfilter/nf_queue.h> |
7fee226a | 20 | #include <net/dst.h> |
f6ebe77f HW |
21 | |
22 | #include "nf_internals.h" | |
23 | ||
601e68e1 | 24 | /* |
0360ae41 FW |
25 | * Hook for nfnetlink_queue to register its queue handler. |
26 | * We do this so that most of the NFQUEUE code can be modular. | |
27 | * | |
28 | * Once the queue is registered it must reinject all packets it | |
29 | * receives, no matter what. | |
f6ebe77f | 30 | */ |
f6ebe77f | 31 | |
d72367b6 HW |
32 | /* return EBUSY when somebody else is registered, return EEXIST if the |
33 | * same handler is registered, return 0 in case of success. */ | |
dc3ee32e | 34 | void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh) |
601e68e1 | 35 | { |
0360ae41 | 36 | /* should never happen, we only have one queueing backend in kernel */ |
dc3ee32e EB |
37 | WARN_ON(rcu_access_pointer(net->nf.queue_handler)); |
38 | rcu_assign_pointer(net->nf.queue_handler, qh); | |
f6ebe77f HW |
39 | } |
40 | EXPORT_SYMBOL(nf_register_queue_handler); | |
41 | ||
42 | /* The caller must flush their queue before this */ | |
dc3ee32e | 43 | void nf_unregister_queue_handler(struct net *net) |
f6ebe77f | 44 | { |
dc3ee32e | 45 | RCU_INIT_POINTER(net->nf.queue_handler, NULL); |
f6ebe77f HW |
46 | } |
47 | EXPORT_SYMBOL(nf_unregister_queue_handler); | |
48 | ||
c4b0e771 FW |
49 | static void nf_queue_entry_release_br_nf_refs(struct sk_buff *skb) |
50 | { | |
51 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) | |
52 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); | |
53 | ||
54 | if (nf_bridge) { | |
55 | struct net_device *physdev; | |
56 | ||
57 | physdev = nf_bridge_get_physindev(skb); | |
58 | if (physdev) | |
59 | dev_put(physdev); | |
60 | physdev = nf_bridge_get_physoutdev(skb); | |
61 | if (physdev) | |
62 | dev_put(physdev); | |
63 | } | |
64 | #endif | |
65 | } | |
66 | ||
a5fedd43 | 67 | void nf_queue_entry_release_refs(struct nf_queue_entry *entry) |
daaa8be2 | 68 | { |
1d1de89b DM |
69 | struct nf_hook_state *state = &entry->state; |
70 | ||
daaa8be2 | 71 | /* Release those devices we held, or Alexey will kill me. */ |
1d1de89b DM |
72 | if (state->in) |
73 | dev_put(state->in); | |
74 | if (state->out) | |
75 | dev_put(state->out); | |
1c984f8a DM |
76 | if (state->sk) |
77 | sock_put(state->sk); | |
c4b0e771 FW |
78 | |
79 | nf_queue_entry_release_br_nf_refs(entry->skb); | |
80 | } | |
81 | EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs); | |
82 | ||
83 | static void nf_queue_entry_get_br_nf_refs(struct sk_buff *skb) | |
84 | { | |
1109a90c | 85 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
c4b0e771 FW |
86 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
87 | ||
88 | if (nf_bridge) { | |
c737b7c4 | 89 | struct net_device *physdev; |
daaa8be2 | 90 | |
c4b0e771 | 91 | physdev = nf_bridge_get_physindev(skb); |
c737b7c4 | 92 | if (physdev) |
c4b0e771 FW |
93 | dev_hold(physdev); |
94 | physdev = nf_bridge_get_physoutdev(skb); | |
c737b7c4 | 95 | if (physdev) |
c4b0e771 | 96 | dev_hold(physdev); |
daaa8be2 PM |
97 | } |
98 | #endif | |
daaa8be2 PM |
99 | } |
100 | ||
4bd60443 | 101 | /* Bump dev refs so they don't vanish while packet is out */ |
ed78d09d | 102 | void nf_queue_entry_get_refs(struct nf_queue_entry *entry) |
4bd60443 | 103 | { |
1d1de89b DM |
104 | struct nf_hook_state *state = &entry->state; |
105 | ||
1d1de89b DM |
106 | if (state->in) |
107 | dev_hold(state->in); | |
108 | if (state->out) | |
109 | dev_hold(state->out); | |
1c984f8a DM |
110 | if (state->sk) |
111 | sock_hold(state->sk); | |
4bd60443 | 112 | |
c4b0e771 | 113 | nf_queue_entry_get_br_nf_refs(entry->skb); |
4bd60443 | 114 | } |
a5fedd43 | 115 | EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs); |
4bd60443 | 116 | |
26888dfd | 117 | void nf_queue_nf_hook_drop(struct net *net) |
8405a8ff EB |
118 | { |
119 | const struct nf_queue_handler *qh; | |
8405a8ff | 120 | |
8405a8ff | 121 | rcu_read_lock(); |
dc3ee32e | 122 | qh = rcu_dereference(net->nf.queue_handler); |
2385eb0c | 123 | if (qh) |
26888dfd | 124 | qh->nf_hook_drop(net); |
8405a8ff | 125 | rcu_read_unlock(); |
8405a8ff | 126 | } |
e2a75007 | 127 | EXPORT_SYMBOL_GPL(nf_queue_nf_hook_drop); |
8405a8ff | 128 | |
7db9a51e PNA |
129 | static void nf_ip_saveroute(const struct sk_buff *skb, |
130 | struct nf_queue_entry *entry) | |
131 | { | |
132 | struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
133 | ||
134 | if (entry->state.hook == NF_INET_LOCAL_OUT) { | |
135 | const struct iphdr *iph = ip_hdr(skb); | |
136 | ||
137 | rt_info->tos = iph->tos; | |
138 | rt_info->daddr = iph->daddr; | |
139 | rt_info->saddr = iph->saddr; | |
140 | rt_info->mark = skb->mark; | |
141 | } | |
142 | } | |
143 | ||
144 | static void nf_ip6_saveroute(const struct sk_buff *skb, | |
145 | struct nf_queue_entry *entry) | |
146 | { | |
147 | struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
148 | ||
149 | if (entry->state.hook == NF_INET_LOCAL_OUT) { | |
150 | const struct ipv6hdr *iph = ipv6_hdr(skb); | |
151 | ||
152 | rt_info->daddr = iph->daddr; | |
153 | rt_info->saddr = iph->saddr; | |
154 | rt_info->mark = skb->mark; | |
155 | } | |
156 | } | |
157 | ||
7034b566 | 158 | static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state, |
960632ec AC |
159 | const struct nf_hook_entries *entries, |
160 | unsigned int index, unsigned int queuenum) | |
f6ebe77f | 161 | { |
f1585086 | 162 | int status = -ENOENT; |
daaa8be2 | 163 | struct nf_queue_entry *entry = NULL; |
e3ac5298 | 164 | const struct nf_queue_handler *qh; |
dc3ee32e | 165 | struct net *net = state->net; |
46435623 | 166 | unsigned int route_key_size; |
f6ebe77f | 167 | |
25985edc | 168 | /* QUEUE == DROP if no one is waiting, to be safe. */ |
dc3ee32e | 169 | qh = rcu_dereference(net->nf.queue_handler); |
94b27cc3 FW |
170 | if (!qh) { |
171 | status = -ESRCH; | |
81b4325e | 172 | goto err; |
94b27cc3 | 173 | } |
f6ebe77f | 174 | |
46435623 PNA |
175 | switch (state->pf) { |
176 | case AF_INET: | |
177 | route_key_size = sizeof(struct ip_rt_info); | |
178 | break; | |
179 | case AF_INET6: | |
180 | route_key_size = sizeof(struct ip6_rt_info); | |
181 | break; | |
182 | default: | |
183 | route_key_size = 0; | |
184 | break; | |
185 | } | |
bce8032e | 186 | |
46435623 | 187 | entry = kmalloc(sizeof(*entry) + route_key_size, GFP_ATOMIC); |
f1585086 FW |
188 | if (!entry) { |
189 | status = -ENOMEM; | |
81b4325e | 190 | goto err; |
f1585086 | 191 | } |
f6ebe77f | 192 | |
02f014d8 PM |
193 | *entry = (struct nf_queue_entry) { |
194 | .skb = skb, | |
1d1de89b | 195 | .state = *state, |
960632ec | 196 | .hook_index = index, |
46435623 | 197 | .size = sizeof(*entry) + route_key_size, |
02f014d8 | 198 | }; |
f6ebe77f | 199 | |
ed78d09d | 200 | nf_queue_entry_get_refs(entry); |
7fee226a | 201 | skb_dst_force(skb); |
7db9a51e PNA |
202 | |
203 | switch (entry->state.pf) { | |
204 | case AF_INET: | |
205 | nf_ip_saveroute(skb, entry); | |
206 | break; | |
207 | case AF_INET6: | |
208 | nf_ip6_saveroute(skb, entry); | |
209 | break; | |
210 | } | |
211 | ||
02f014d8 | 212 | status = qh->outfn(entry, queuenum); |
f6ebe77f | 213 | |
f6ebe77f | 214 | if (status < 0) { |
daaa8be2 PM |
215 | nf_queue_entry_release_refs(entry); |
216 | goto err; | |
f6ebe77f HW |
217 | } |
218 | ||
f1585086 | 219 | return 0; |
daaa8be2 | 220 | |
daaa8be2 | 221 | err: |
daaa8be2 | 222 | kfree(entry); |
f1585086 | 223 | return status; |
f6ebe77f HW |
224 | } |
225 | ||
7034b566 PNA |
226 | /* Packets leaving via this function must come back through nf_reinject(). */ |
227 | int nf_queue(struct sk_buff *skb, struct nf_hook_state *state, | |
960632ec AC |
228 | const struct nf_hook_entries *entries, unsigned int index, |
229 | unsigned int verdict) | |
7034b566 | 230 | { |
7034b566 PNA |
231 | int ret; |
232 | ||
960632ec | 233 | ret = __nf_queue(skb, state, entries, index, verdict >> NF_VERDICT_QBITS); |
7034b566 PNA |
234 | if (ret < 0) { |
235 | if (ret == -ESRCH && | |
960632ec | 236 | (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS)) |
7034b566 | 237 | return 1; |
7034b566 PNA |
238 | kfree_skb(skb); |
239 | } | |
240 | ||
241 | return 0; | |
242 | } | |
971502d7 | 243 | EXPORT_SYMBOL_GPL(nf_queue); |
7034b566 | 244 | |
26dfab72 PNA |
245 | static unsigned int nf_iterate(struct sk_buff *skb, |
246 | struct nf_hook_state *state, | |
960632ec AC |
247 | const struct nf_hook_entries *hooks, |
248 | unsigned int *index) | |
26dfab72 | 249 | { |
960632ec AC |
250 | const struct nf_hook_entry *hook; |
251 | unsigned int verdict, i = *index; | |
26dfab72 | 252 | |
960632ec AC |
253 | while (i < hooks->num_hook_entries) { |
254 | hook = &hooks->hooks[i]; | |
26dfab72 | 255 | repeat: |
960632ec | 256 | verdict = nf_hook_entry_hookfn(hook, skb, state); |
26dfab72 PNA |
257 | if (verdict != NF_ACCEPT) { |
258 | if (verdict != NF_REPEAT) | |
259 | return verdict; | |
260 | goto repeat; | |
261 | } | |
960632ec AC |
262 | i++; |
263 | } | |
26dfab72 | 264 | |
960632ec | 265 | *index = i; |
26dfab72 PNA |
266 | return NF_ACCEPT; |
267 | } | |
268 | ||
b0f38338 FW |
269 | static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum) |
270 | { | |
271 | switch (pf) { | |
2a95183a | 272 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE |
b0f38338 FW |
273 | case NFPROTO_BRIDGE: |
274 | return rcu_dereference(net->nf.hooks_bridge[hooknum]); | |
2a95183a | 275 | #endif |
b0f38338 FW |
276 | case NFPROTO_IPV4: |
277 | return rcu_dereference(net->nf.hooks_ipv4[hooknum]); | |
278 | case NFPROTO_IPV6: | |
279 | return rcu_dereference(net->nf.hooks_ipv6[hooknum]); | |
280 | default: | |
281 | WARN_ON_ONCE(1); | |
282 | return NULL; | |
283 | } | |
284 | ||
285 | return NULL; | |
286 | } | |
287 | ||
960632ec | 288 | /* Caller must hold rcu read-side lock */ |
02f014d8 | 289 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 290 | { |
960632ec AC |
291 | const struct nf_hook_entry *hook_entry; |
292 | const struct nf_hook_entries *hooks; | |
02f014d8 | 293 | struct sk_buff *skb = entry->skb; |
960632ec AC |
294 | const struct net *net; |
295 | unsigned int i; | |
f1585086 | 296 | int err; |
960632ec AC |
297 | u8 pf; |
298 | ||
299 | net = entry->state.net; | |
300 | pf = entry->state.pf; | |
301 | ||
b0f38338 | 302 | hooks = nf_hook_entries_head(net, pf, entry->state.hook); |
f6ebe77f | 303 | |
daaa8be2 | 304 | nf_queue_entry_release_refs(entry); |
f6ebe77f | 305 | |
960632ec | 306 | i = entry->hook_index; |
b0f38338 | 307 | if (WARN_ON_ONCE(!hooks || i >= hooks->num_hook_entries)) { |
960632ec AC |
308 | kfree_skb(skb); |
309 | kfree(entry); | |
310 | return; | |
311 | } | |
312 | ||
313 | hook_entry = &hooks->hooks[i]; | |
314 | ||
f6ebe77f | 315 | /* Continue traversal iff userspace said ok... */ |
7ceebfe4 | 316 | if (verdict == NF_REPEAT) |
0aa8c57a | 317 | verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state); |
f6ebe77f | 318 | |
7a11b984 | 319 | if (verdict == NF_ACCEPT) { |
ce388f45 | 320 | if (nf_reroute(skb, entry) < 0) |
7a11b984 PM |
321 | verdict = NF_DROP; |
322 | } | |
323 | ||
f6ebe77f | 324 | if (verdict == NF_ACCEPT) { |
7034b566 | 325 | next_hook: |
960632ec AC |
326 | ++i; |
327 | verdict = nf_iterate(skb, &entry->state, hooks, &i); | |
f6ebe77f HW |
328 | } |
329 | ||
330 | switch (verdict & NF_VERDICT_MASK) { | |
331 | case NF_ACCEPT: | |
3bc38712 | 332 | case NF_STOP: |
4b3d15ef | 333 | local_bh_disable(); |
0c4b51f0 | 334 | entry->state.okfn(entry->state.net, entry->state.sk, skb); |
4b3d15ef | 335 | local_bh_enable(); |
f6ebe77f | 336 | break; |
f6ebe77f | 337 | case NF_QUEUE: |
960632ec AC |
338 | err = nf_queue(skb, &entry->state, hooks, i, verdict); |
339 | if (err == 1) | |
340 | goto next_hook; | |
f6ebe77f | 341 | break; |
64507fdb | 342 | case NF_STOLEN: |
fad54440 | 343 | break; |
3bc38712 PM |
344 | default: |
345 | kfree_skb(skb); | |
f6ebe77f | 346 | } |
81b4325e | 347 | |
02f014d8 | 348 | kfree(entry); |
f6ebe77f HW |
349 | } |
350 | EXPORT_SYMBOL(nf_reinject); |