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 | ||
dd3cc111 | 49 | static void nf_queue_entry_release_refs(struct nf_queue_entry *entry) |
daaa8be2 | 50 | { |
1d1de89b DM |
51 | struct nf_hook_state *state = &entry->state; |
52 | ||
daaa8be2 | 53 | /* Release those devices we held, or Alexey will kill me. */ |
1d1de89b DM |
54 | if (state->in) |
55 | dev_put(state->in); | |
56 | if (state->out) | |
57 | dev_put(state->out); | |
1c984f8a DM |
58 | if (state->sk) |
59 | sock_put(state->sk); | |
c4b0e771 | 60 | |
119e52e6 FW |
61 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
62 | if (entry->physin) | |
63 | dev_put(entry->physin); | |
64 | if (entry->physout) | |
65 | dev_put(entry->physout); | |
66 | #endif | |
c4b0e771 | 67 | } |
dd3cc111 FW |
68 | |
69 | void nf_queue_entry_free(struct nf_queue_entry *entry) | |
70 | { | |
71 | nf_queue_entry_release_refs(entry); | |
72 | kfree(entry); | |
73 | } | |
74 | EXPORT_SYMBOL_GPL(nf_queue_entry_free); | |
c4b0e771 | 75 | |
119e52e6 | 76 | static void __nf_queue_entry_init_physdevs(struct nf_queue_entry *entry) |
c4b0e771 | 77 | { |
1109a90c | 78 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
119e52e6 FW |
79 | const struct sk_buff *skb = entry->skb; |
80 | struct nf_bridge_info *nf_bridge; | |
c4b0e771 | 81 | |
119e52e6 | 82 | nf_bridge = nf_bridge_info_get(skb); |
c4b0e771 | 83 | if (nf_bridge) { |
119e52e6 FW |
84 | entry->physin = nf_bridge_get_physindev(skb); |
85 | entry->physout = nf_bridge_get_physoutdev(skb); | |
86 | } else { | |
87 | entry->physin = NULL; | |
88 | entry->physout = NULL; | |
daaa8be2 PM |
89 | } |
90 | #endif | |
daaa8be2 PM |
91 | } |
92 | ||
4bd60443 | 93 | /* Bump dev refs so they don't vanish while packet is out */ |
ed78d09d | 94 | void nf_queue_entry_get_refs(struct nf_queue_entry *entry) |
4bd60443 | 95 | { |
1d1de89b DM |
96 | struct nf_hook_state *state = &entry->state; |
97 | ||
1d1de89b DM |
98 | if (state->in) |
99 | dev_hold(state->in); | |
100 | if (state->out) | |
101 | dev_hold(state->out); | |
1c984f8a DM |
102 | if (state->sk) |
103 | sock_hold(state->sk); | |
4bd60443 | 104 | |
119e52e6 FW |
105 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
106 | if (entry->physin) | |
107 | dev_hold(entry->physin); | |
108 | if (entry->physout) | |
109 | dev_hold(entry->physout); | |
110 | #endif | |
4bd60443 | 111 | } |
a5fedd43 | 112 | EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs); |
4bd60443 | 113 | |
26888dfd | 114 | void nf_queue_nf_hook_drop(struct net *net) |
8405a8ff EB |
115 | { |
116 | const struct nf_queue_handler *qh; | |
8405a8ff | 117 | |
8405a8ff | 118 | rcu_read_lock(); |
dc3ee32e | 119 | qh = rcu_dereference(net->nf.queue_handler); |
2385eb0c | 120 | if (qh) |
26888dfd | 121 | qh->nf_hook_drop(net); |
8405a8ff | 122 | rcu_read_unlock(); |
8405a8ff | 123 | } |
e2a75007 | 124 | EXPORT_SYMBOL_GPL(nf_queue_nf_hook_drop); |
8405a8ff | 125 | |
7db9a51e PNA |
126 | static void nf_ip_saveroute(const struct sk_buff *skb, |
127 | struct nf_queue_entry *entry) | |
128 | { | |
129 | struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
130 | ||
131 | if (entry->state.hook == NF_INET_LOCAL_OUT) { | |
132 | const struct iphdr *iph = ip_hdr(skb); | |
133 | ||
134 | rt_info->tos = iph->tos; | |
135 | rt_info->daddr = iph->daddr; | |
136 | rt_info->saddr = iph->saddr; | |
137 | rt_info->mark = skb->mark; | |
138 | } | |
139 | } | |
140 | ||
141 | static void nf_ip6_saveroute(const struct sk_buff *skb, | |
142 | struct nf_queue_entry *entry) | |
143 | { | |
144 | struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
145 | ||
146 | if (entry->state.hook == NF_INET_LOCAL_OUT) { | |
147 | const struct ipv6hdr *iph = ipv6_hdr(skb); | |
148 | ||
149 | rt_info->daddr = iph->daddr; | |
150 | rt_info->saddr = iph->saddr; | |
151 | rt_info->mark = skb->mark; | |
152 | } | |
153 | } | |
154 | ||
7034b566 | 155 | static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state, |
960632ec | 156 | unsigned int index, unsigned int queuenum) |
f6ebe77f | 157 | { |
daaa8be2 | 158 | struct nf_queue_entry *entry = NULL; |
e3ac5298 | 159 | const struct nf_queue_handler *qh; |
dc3ee32e | 160 | struct net *net = state->net; |
46435623 | 161 | unsigned int route_key_size; |
28f715b9 | 162 | int status; |
f6ebe77f | 163 | |
25985edc | 164 | /* QUEUE == DROP if no one is waiting, to be safe. */ |
dc3ee32e | 165 | qh = rcu_dereference(net->nf.queue_handler); |
28f715b9 FW |
166 | if (!qh) |
167 | return -ESRCH; | |
f6ebe77f | 168 | |
46435623 PNA |
169 | switch (state->pf) { |
170 | case AF_INET: | |
171 | route_key_size = sizeof(struct ip_rt_info); | |
172 | break; | |
173 | case AF_INET6: | |
174 | route_key_size = sizeof(struct ip6_rt_info); | |
175 | break; | |
176 | default: | |
177 | route_key_size = 0; | |
178 | break; | |
179 | } | |
bce8032e | 180 | |
46435623 | 181 | entry = kmalloc(sizeof(*entry) + route_key_size, GFP_ATOMIC); |
28f715b9 FW |
182 | if (!entry) |
183 | return -ENOMEM; | |
f6ebe77f | 184 | |
0b9173f4 | 185 | if (skb_dst(skb) && !skb_dst_force(skb)) { |
28f715b9 FW |
186 | kfree(entry); |
187 | return -ENETDOWN; | |
b60a7738 FW |
188 | } |
189 | ||
02f014d8 PM |
190 | *entry = (struct nf_queue_entry) { |
191 | .skb = skb, | |
1d1de89b | 192 | .state = *state, |
960632ec | 193 | .hook_index = index, |
46435623 | 194 | .size = sizeof(*entry) + route_key_size, |
02f014d8 | 195 | }; |
f6ebe77f | 196 | |
119e52e6 FW |
197 | __nf_queue_entry_init_physdevs(entry); |
198 | ||
ed78d09d | 199 | nf_queue_entry_get_refs(entry); |
7db9a51e PNA |
200 | |
201 | switch (entry->state.pf) { | |
202 | case AF_INET: | |
203 | nf_ip_saveroute(skb, entry); | |
204 | break; | |
205 | case AF_INET6: | |
206 | nf_ip6_saveroute(skb, entry); | |
207 | break; | |
208 | } | |
209 | ||
02f014d8 | 210 | status = qh->outfn(entry, queuenum); |
f6ebe77f | 211 | if (status < 0) { |
28f715b9 FW |
212 | nf_queue_entry_free(entry); |
213 | return status; | |
f6ebe77f HW |
214 | } |
215 | ||
f1585086 | 216 | return 0; |
f6ebe77f HW |
217 | } |
218 | ||
7034b566 PNA |
219 | /* Packets leaving via this function must come back through nf_reinject(). */ |
220 | int nf_queue(struct sk_buff *skb, struct nf_hook_state *state, | |
0d9cb300 | 221 | unsigned int index, unsigned int verdict) |
7034b566 | 222 | { |
7034b566 PNA |
223 | int ret; |
224 | ||
0d9cb300 | 225 | ret = __nf_queue(skb, state, index, verdict >> NF_VERDICT_QBITS); |
7034b566 PNA |
226 | if (ret < 0) { |
227 | if (ret == -ESRCH && | |
960632ec | 228 | (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS)) |
7034b566 | 229 | return 1; |
7034b566 PNA |
230 | kfree_skb(skb); |
231 | } | |
232 | ||
233 | return 0; | |
234 | } | |
971502d7 | 235 | EXPORT_SYMBOL_GPL(nf_queue); |
7034b566 | 236 | |
26dfab72 PNA |
237 | static unsigned int nf_iterate(struct sk_buff *skb, |
238 | struct nf_hook_state *state, | |
960632ec AC |
239 | const struct nf_hook_entries *hooks, |
240 | unsigned int *index) | |
26dfab72 | 241 | { |
960632ec AC |
242 | const struct nf_hook_entry *hook; |
243 | unsigned int verdict, i = *index; | |
26dfab72 | 244 | |
960632ec AC |
245 | while (i < hooks->num_hook_entries) { |
246 | hook = &hooks->hooks[i]; | |
26dfab72 | 247 | repeat: |
960632ec | 248 | verdict = nf_hook_entry_hookfn(hook, skb, state); |
26dfab72 | 249 | if (verdict != NF_ACCEPT) { |
946c0d8e | 250 | *index = i; |
26dfab72 PNA |
251 | if (verdict != NF_REPEAT) |
252 | return verdict; | |
253 | goto repeat; | |
254 | } | |
960632ec AC |
255 | i++; |
256 | } | |
26dfab72 | 257 | |
960632ec | 258 | *index = i; |
26dfab72 PNA |
259 | return NF_ACCEPT; |
260 | } | |
261 | ||
b0f38338 FW |
262 | static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum) |
263 | { | |
264 | switch (pf) { | |
2a95183a | 265 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE |
b0f38338 FW |
266 | case NFPROTO_BRIDGE: |
267 | return rcu_dereference(net->nf.hooks_bridge[hooknum]); | |
2a95183a | 268 | #endif |
b0f38338 FW |
269 | case NFPROTO_IPV4: |
270 | return rcu_dereference(net->nf.hooks_ipv4[hooknum]); | |
271 | case NFPROTO_IPV6: | |
272 | return rcu_dereference(net->nf.hooks_ipv6[hooknum]); | |
273 | default: | |
274 | WARN_ON_ONCE(1); | |
275 | return NULL; | |
276 | } | |
277 | ||
278 | return NULL; | |
279 | } | |
280 | ||
960632ec | 281 | /* Caller must hold rcu read-side lock */ |
02f014d8 | 282 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 283 | { |
960632ec AC |
284 | const struct nf_hook_entry *hook_entry; |
285 | const struct nf_hook_entries *hooks; | |
02f014d8 | 286 | struct sk_buff *skb = entry->skb; |
960632ec AC |
287 | const struct net *net; |
288 | unsigned int i; | |
f1585086 | 289 | int err; |
960632ec AC |
290 | u8 pf; |
291 | ||
292 | net = entry->state.net; | |
293 | pf = entry->state.pf; | |
294 | ||
b0f38338 | 295 | hooks = nf_hook_entries_head(net, pf, entry->state.hook); |
f6ebe77f | 296 | |
960632ec | 297 | i = entry->hook_index; |
b0f38338 | 298 | if (WARN_ON_ONCE(!hooks || i >= hooks->num_hook_entries)) { |
960632ec | 299 | kfree_skb(skb); |
af370ab3 | 300 | nf_queue_entry_free(entry); |
960632ec AC |
301 | return; |
302 | } | |
303 | ||
304 | hook_entry = &hooks->hooks[i]; | |
305 | ||
f6ebe77f | 306 | /* Continue traversal iff userspace said ok... */ |
7ceebfe4 | 307 | if (verdict == NF_REPEAT) |
0aa8c57a | 308 | verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state); |
f6ebe77f | 309 | |
7a11b984 | 310 | if (verdict == NF_ACCEPT) { |
ce388f45 | 311 | if (nf_reroute(skb, entry) < 0) |
7a11b984 PM |
312 | verdict = NF_DROP; |
313 | } | |
314 | ||
f6ebe77f | 315 | if (verdict == NF_ACCEPT) { |
7034b566 | 316 | next_hook: |
960632ec AC |
317 | ++i; |
318 | verdict = nf_iterate(skb, &entry->state, hooks, &i); | |
f6ebe77f HW |
319 | } |
320 | ||
321 | switch (verdict & NF_VERDICT_MASK) { | |
322 | case NF_ACCEPT: | |
3bc38712 | 323 | case NF_STOP: |
4b3d15ef | 324 | local_bh_disable(); |
0c4b51f0 | 325 | entry->state.okfn(entry->state.net, entry->state.sk, skb); |
4b3d15ef | 326 | local_bh_enable(); |
f6ebe77f | 327 | break; |
f6ebe77f | 328 | case NF_QUEUE: |
0d9cb300 | 329 | err = nf_queue(skb, &entry->state, i, verdict); |
960632ec AC |
330 | if (err == 1) |
331 | goto next_hook; | |
f6ebe77f | 332 | break; |
64507fdb | 333 | case NF_STOLEN: |
fad54440 | 334 | break; |
3bc38712 PM |
335 | default: |
336 | kfree_skb(skb); | |
f6ebe77f | 337 | } |
81b4325e | 338 | |
af370ab3 | 339 | nf_queue_entry_free(entry); |
f6ebe77f HW |
340 | } |
341 | EXPORT_SYMBOL(nf_reinject); |