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 void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
49 struct nf_hook_state *state = &entry->state;
51 /* Release those devices we held, or Alexey will kill me. */
58 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
59 if (entry->skb->nf_bridge) {
60 struct net_device *physdev;
62 physdev = nf_bridge_get_physindev(entry->skb);
65 physdev = nf_bridge_get_physoutdev(entry->skb);
71 EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs);
73 /* Bump dev refs so they don't vanish while packet is out */
74 void nf_queue_entry_get_refs(struct nf_queue_entry *entry)
76 struct nf_hook_state *state = &entry->state;
84 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
85 if (entry->skb->nf_bridge) {
86 struct net_device *physdev;
88 physdev = nf_bridge_get_physindev(entry->skb);
91 physdev = nf_bridge_get_physoutdev(entry->skb);
97 EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);
99 void nf_queue_nf_hook_drop(struct net *net, struct nf_hook_ops *ops)
101 const struct nf_queue_handler *qh;
104 qh = rcu_dereference(net->nf.queue_handler);
106 qh->nf_hook_drop(net, ops);
111 * Any packet that leaves via this function must come back
112 * through nf_reinject().
114 int nf_queue(struct sk_buff *skb,
115 struct nf_hook_ops *elem,
116 struct nf_hook_state *state,
117 unsigned int queuenum)
119 int status = -ENOENT;
120 struct nf_queue_entry *entry = NULL;
121 const struct nf_afinfo *afinfo;
122 const struct nf_queue_handler *qh;
123 struct net *net = state->net;
125 /* QUEUE == DROP if no one is waiting, to be safe. */
126 qh = rcu_dereference(net->nf.queue_handler);
132 afinfo = nf_get_afinfo(state->pf);
136 entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);
142 *entry = (struct nf_queue_entry) {
146 .size = sizeof(*entry) + afinfo->route_key_size,
149 nf_queue_entry_get_refs(entry);
151 afinfo->saveroute(skb, entry);
152 status = qh->outfn(entry, queuenum);
155 nf_queue_entry_release_refs(entry);
166 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
168 struct sk_buff *skb = entry->skb;
169 struct nf_hook_ops *elem = entry->elem;
170 const struct nf_afinfo *afinfo;
173 nf_queue_entry_release_refs(entry);
175 /* Continue traversal iff userspace said ok... */
176 if (verdict == NF_REPEAT)
177 verdict = elem->hook(elem->priv, skb, &entry->state);
179 if (verdict == NF_ACCEPT) {
180 afinfo = nf_get_afinfo(entry->state.pf);
181 if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0)
185 entry->state.thresh = INT_MIN;
187 if (verdict == NF_ACCEPT) {
189 verdict = nf_iterate(entry->state.hook_list,
190 skb, &entry->state, &elem);
193 switch (verdict & NF_VERDICT_MASK) {
197 entry->state.okfn(entry->state.net, entry->state.sk, skb);
201 err = nf_queue(skb, elem, &entry->state,
202 verdict >> NF_VERDICT_QBITS);
205 (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS))
218 EXPORT_SYMBOL(nf_reinject);