2 * Rusty Russell (C)2000 -- This code is GPL.
3 * Patrick McHardy (c) 2006-2012
6 #include <linux/kernel.h>
7 #include <linux/slab.h>
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>
13 #include <linux/netfilter_bridge.h>
14 #include <linux/seq_file.h>
15 #include <linux/rcupdate.h>
16 #include <net/protocol.h>
17 #include <net/netfilter/nf_queue.h>
20 #include "nf_internals.h"
23 * Hook for nfnetlink_queue to register its queue handler.
24 * We do this so that most of the NFQUEUE code can be modular.
26 * Once the queue is registered it must reinject all packets it
27 * receives, no matter what.
30 /* return EBUSY when somebody else is registered, return EEXIST if the
31 * same handler is registered, return 0 in case of success. */
32 void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh)
34 /* should never happen, we only have one queueing backend in kernel */
35 WARN_ON(rcu_access_pointer(net->nf.queue_handler));
36 rcu_assign_pointer(net->nf.queue_handler, qh);
38 EXPORT_SYMBOL(nf_register_queue_handler);
40 /* The caller must flush their queue before this */
41 void nf_unregister_queue_handler(struct net *net)
43 RCU_INIT_POINTER(net->nf.queue_handler, NULL);
45 EXPORT_SYMBOL(nf_unregister_queue_handler);
47 static void nf_queue_sock_put(struct sock *sk)
56 void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
58 struct nf_hook_state *state = &entry->state;
60 /* Release those devices we held, or Alexey will kill me. */
66 nf_queue_sock_put(state->sk);
67 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
68 if (entry->skb->nf_bridge) {
69 struct net_device *physdev;
71 physdev = nf_bridge_get_physindev(entry->skb);
74 physdev = nf_bridge_get_physoutdev(entry->skb);
80 EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs);
82 /* Bump dev refs so they don't vanish while packet is out */
83 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry)
85 struct nf_hook_state *state = &entry->state;
87 if (state->sk && !refcount_inc_not_zero(&state->sk->sk_refcnt))
94 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
95 if (entry->skb->nf_bridge) {
96 struct net_device *physdev;
98 physdev = nf_bridge_get_physindev(entry->skb);
101 physdev = nf_bridge_get_physoutdev(entry->skb);
108 EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);
110 unsigned int nf_queue_nf_hook_drop(struct net *net)
112 const struct nf_queue_handler *qh;
113 unsigned int count = 0;
116 qh = rcu_dereference(net->nf.queue_handler);
118 count = qh->nf_hook_drop(net);
123 EXPORT_SYMBOL_GPL(nf_queue_nf_hook_drop);
125 static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state,
126 const struct nf_hook_entries *entries,
127 unsigned int index, unsigned int queuenum)
129 int status = -ENOENT;
130 struct nf_queue_entry *entry = NULL;
131 const struct nf_afinfo *afinfo;
132 const struct nf_queue_handler *qh;
133 struct net *net = state->net;
135 /* QUEUE == DROP if no one is waiting, to be safe. */
136 qh = rcu_dereference(net->nf.queue_handler);
142 afinfo = nf_get_afinfo(state->pf);
146 entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);
152 if (skb_dst(skb) && !skb_dst_force(skb)) {
157 *entry = (struct nf_queue_entry) {
161 .size = sizeof(*entry) + afinfo->route_key_size,
164 if (!nf_queue_entry_get_refs(entry)) {
169 afinfo->saveroute(skb, entry);
170 status = qh->outfn(entry, queuenum);
173 nf_queue_entry_release_refs(entry);
184 /* Packets leaving via this function must come back through nf_reinject(). */
185 int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
186 const struct nf_hook_entries *entries, unsigned int index,
187 unsigned int verdict)
191 ret = __nf_queue(skb, state, entries, index, verdict >> NF_VERDICT_QBITS);
194 (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS))
202 static unsigned int nf_iterate(struct sk_buff *skb,
203 struct nf_hook_state *state,
204 const struct nf_hook_entries *hooks,
207 const struct nf_hook_entry *hook;
208 unsigned int verdict, i = *index;
210 while (i < hooks->num_hook_entries) {
211 hook = &hooks->hooks[i];
213 verdict = nf_hook_entry_hookfn(hook, skb, state);
214 if (verdict != NF_ACCEPT) {
216 if (verdict != NF_REPEAT)
227 /* Caller must hold rcu read-side lock */
228 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
230 const struct nf_hook_entry *hook_entry;
231 const struct nf_hook_entries *hooks;
232 struct sk_buff *skb = entry->skb;
233 const struct nf_afinfo *afinfo;
234 const struct net *net;
239 net = entry->state.net;
240 pf = entry->state.pf;
242 hooks = rcu_dereference(net->nf.hooks[pf][entry->state.hook]);
244 nf_queue_entry_release_refs(entry);
246 i = entry->hook_index;
247 if (WARN_ON_ONCE(i >= hooks->num_hook_entries)) {
253 hook_entry = &hooks->hooks[i];
255 /* Continue traversal iff userspace said ok... */
256 if (verdict == NF_REPEAT)
257 verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state);
259 if (verdict == NF_ACCEPT) {
260 afinfo = nf_get_afinfo(entry->state.pf);
261 if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0)
265 if (verdict == NF_ACCEPT) {
268 verdict = nf_iterate(skb, &entry->state, hooks, &i);
271 switch (verdict & NF_VERDICT_MASK) {
275 entry->state.okfn(entry->state.net, entry->state.sk, skb);
279 err = nf_queue(skb, &entry->state, hooks, i, verdict);
291 EXPORT_SYMBOL(nf_reinject);