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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 | |
e3b37f11 | 99 | void nf_queue_nf_hook_drop(struct net *net, const struct nf_hook_entry *entry) |
8405a8ff EB |
100 | { |
101 | const struct nf_queue_handler *qh; | |
8405a8ff | 102 | |
8405a8ff | 103 | rcu_read_lock(); |
dc3ee32e | 104 | qh = rcu_dereference(net->nf.queue_handler); |
2385eb0c | 105 | if (qh) |
e3b37f11 | 106 | qh->nf_hook_drop(net, entry); |
8405a8ff | 107 | rcu_read_unlock(); |
8405a8ff EB |
108 | } |
109 | ||
7034b566 | 110 | static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state, |
01886bd9 | 111 | struct nf_hook_entry *hook_entry, unsigned int queuenum) |
f6ebe77f | 112 | { |
f1585086 | 113 | int status = -ENOENT; |
daaa8be2 | 114 | struct nf_queue_entry *entry = NULL; |
1e796fda | 115 | const struct nf_afinfo *afinfo; |
e3ac5298 | 116 | const struct nf_queue_handler *qh; |
dc3ee32e | 117 | struct net *net = state->net; |
f6ebe77f | 118 | |
25985edc | 119 | /* QUEUE == DROP if no one is waiting, to be safe. */ |
dc3ee32e | 120 | qh = rcu_dereference(net->nf.queue_handler); |
94b27cc3 FW |
121 | if (!qh) { |
122 | status = -ESRCH; | |
81b4325e | 123 | goto err; |
94b27cc3 | 124 | } |
f6ebe77f | 125 | |
cfdfab31 | 126 | afinfo = nf_get_afinfo(state->pf); |
daaa8be2 | 127 | if (!afinfo) |
81b4325e | 128 | goto err; |
bce8032e | 129 | |
02f014d8 | 130 | entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC); |
f1585086 FW |
131 | if (!entry) { |
132 | status = -ENOMEM; | |
81b4325e | 133 | goto err; |
f1585086 | 134 | } |
f6ebe77f | 135 | |
02f014d8 PM |
136 | *entry = (struct nf_queue_entry) { |
137 | .skb = skb, | |
1d1de89b | 138 | .state = *state, |
01886bd9 | 139 | .hook = hook_entry, |
a5fedd43 | 140 | .size = sizeof(*entry) + afinfo->route_key_size, |
02f014d8 | 141 | }; |
f6ebe77f | 142 | |
ed78d09d | 143 | nf_queue_entry_get_refs(entry); |
7fee226a | 144 | skb_dst_force(skb); |
02f014d8 PM |
145 | afinfo->saveroute(skb, entry); |
146 | status = qh->outfn(entry, queuenum); | |
f6ebe77f | 147 | |
f6ebe77f | 148 | if (status < 0) { |
daaa8be2 PM |
149 | nf_queue_entry_release_refs(entry); |
150 | goto err; | |
f6ebe77f HW |
151 | } |
152 | ||
f1585086 | 153 | return 0; |
daaa8be2 | 154 | |
daaa8be2 | 155 | err: |
daaa8be2 | 156 | kfree(entry); |
f1585086 | 157 | return status; |
f6ebe77f HW |
158 | } |
159 | ||
7034b566 PNA |
160 | /* Packets leaving via this function must come back through nf_reinject(). */ |
161 | int nf_queue(struct sk_buff *skb, struct nf_hook_state *state, | |
162 | struct nf_hook_entry **entryp, unsigned int verdict) | |
163 | { | |
164 | struct nf_hook_entry *entry = *entryp; | |
165 | int ret; | |
166 | ||
01886bd9 | 167 | ret = __nf_queue(skb, state, entry, verdict >> NF_VERDICT_QBITS); |
7034b566 PNA |
168 | if (ret < 0) { |
169 | if (ret == -ESRCH && | |
170 | (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS)) { | |
171 | *entryp = rcu_dereference(entry->next); | |
172 | return 1; | |
173 | } | |
174 | kfree_skb(skb); | |
175 | } | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
26dfab72 PNA |
180 | static unsigned int nf_iterate(struct sk_buff *skb, |
181 | struct nf_hook_state *state, | |
182 | struct nf_hook_entry **entryp) | |
183 | { | |
184 | unsigned int verdict; | |
185 | ||
186 | do { | |
187 | repeat: | |
0aa8c57a | 188 | verdict = nf_hook_entry_hookfn((*entryp), skb, state); |
26dfab72 PNA |
189 | if (verdict != NF_ACCEPT) { |
190 | if (verdict != NF_REPEAT) | |
191 | return verdict; | |
192 | goto repeat; | |
193 | } | |
194 | *entryp = rcu_dereference((*entryp)->next); | |
195 | } while (*entryp); | |
196 | ||
197 | return NF_ACCEPT; | |
198 | } | |
199 | ||
02f014d8 | 200 | void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) |
f6ebe77f | 201 | { |
01886bd9 | 202 | struct nf_hook_entry *hook_entry = entry->hook; |
02f014d8 | 203 | struct sk_buff *skb = entry->skb; |
1e796fda | 204 | const struct nf_afinfo *afinfo; |
f1585086 | 205 | int err; |
f6ebe77f | 206 | |
daaa8be2 | 207 | nf_queue_entry_release_refs(entry); |
f6ebe77f | 208 | |
f6ebe77f | 209 | /* Continue traversal iff userspace said ok... */ |
7ceebfe4 | 210 | if (verdict == NF_REPEAT) |
0aa8c57a | 211 | verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state); |
f6ebe77f | 212 | |
7a11b984 | 213 | if (verdict == NF_ACCEPT) { |
1d1de89b | 214 | afinfo = nf_get_afinfo(entry->state.pf); |
d815d90b | 215 | if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0) |
7a11b984 PM |
216 | verdict = NF_DROP; |
217 | } | |
218 | ||
f6ebe77f | 219 | if (verdict == NF_ACCEPT) { |
7034b566 PNA |
220 | hook_entry = rcu_dereference(hook_entry->next); |
221 | if (hook_entry) | |
222 | next_hook: | |
223 | verdict = nf_iterate(skb, &entry->state, &hook_entry); | |
f6ebe77f HW |
224 | } |
225 | ||
226 | switch (verdict & NF_VERDICT_MASK) { | |
227 | case NF_ACCEPT: | |
3bc38712 | 228 | case NF_STOP: |
7034b566 | 229 | okfn: |
4b3d15ef | 230 | local_bh_disable(); |
0c4b51f0 | 231 | entry->state.okfn(entry->state.net, entry->state.sk, skb); |
4b3d15ef | 232 | local_bh_enable(); |
f6ebe77f | 233 | break; |
f6ebe77f | 234 | case NF_QUEUE: |
7034b566 PNA |
235 | err = nf_queue(skb, &entry->state, &hook_entry, verdict); |
236 | if (err == 1) { | |
237 | if (hook_entry) | |
94b27cc3 | 238 | goto next_hook; |
7034b566 | 239 | goto okfn; |
06cdb634 | 240 | } |
f6ebe77f | 241 | break; |
64507fdb | 242 | case NF_STOLEN: |
fad54440 | 243 | break; |
3bc38712 PM |
244 | default: |
245 | kfree_skb(skb); | |
f6ebe77f | 246 | } |
81b4325e | 247 | |
02f014d8 | 248 | kfree(entry); |
f6ebe77f HW |
249 | } |
250 | EXPORT_SYMBOL(nf_reinject); |