1 #include <linux/kernel.h>
2 #include <linux/init.h>
3 #include <linux/module.h>
4 #include <linux/proc_fs.h>
5 #include <linux/skbuff.h>
6 #include <linux/netfilter.h>
7 #include <linux/seq_file.h>
8 #include <linux/rcupdate.h>
9 #include <net/protocol.h>
11 #include "nf_internals.h"
14 * A queue handler may be registered for each protocol. Each is protected by
15 * long term mutex. The handler must provide an an outfn() to accept packets
16 * for queueing and must reinject all packets it receives, no matter what.
18 static struct nf_queue_handler *queue_handler[NPROTO];
20 static DEFINE_RWLOCK(queue_handler_lock);
22 /* return EBUSY when somebody else is registered, return EEXIST if the
23 * same handler is registered, return 0 in case of success. */
24 int nf_register_queue_handler(int pf, struct nf_queue_handler *qh)
31 write_lock_bh(&queue_handler_lock);
32 if (queue_handler[pf] == qh)
34 else if (queue_handler[pf])
37 queue_handler[pf] = qh;
40 write_unlock_bh(&queue_handler_lock);
44 EXPORT_SYMBOL(nf_register_queue_handler);
46 /* The caller must flush their queue before this */
47 int nf_unregister_queue_handler(int pf)
52 write_lock_bh(&queue_handler_lock);
53 queue_handler[pf] = NULL;
54 write_unlock_bh(&queue_handler_lock);
58 EXPORT_SYMBOL(nf_unregister_queue_handler);
60 void nf_unregister_queue_handlers(struct nf_queue_handler *qh)
64 write_lock_bh(&queue_handler_lock);
65 for (pf = 0; pf < NPROTO; pf++) {
66 if (queue_handler[pf] == qh)
67 queue_handler[pf] = NULL;
69 write_unlock_bh(&queue_handler_lock);
71 EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
74 * Any packet that leaves via this function must come back
75 * through nf_reinject().
77 int nf_queue(struct sk_buff **skb,
78 struct list_head *elem,
79 int pf, unsigned int hook,
80 struct net_device *indev,
81 struct net_device *outdev,
82 int (*okfn)(struct sk_buff *),
83 unsigned int queuenum)
87 #ifdef CONFIG_BRIDGE_NETFILTER
88 struct net_device *physindev = NULL;
89 struct net_device *physoutdev = NULL;
91 struct nf_afinfo *afinfo;
93 /* QUEUE == DROP if noone is waiting, to be safe. */
94 read_lock(&queue_handler_lock);
95 if (!queue_handler[pf]) {
96 read_unlock(&queue_handler_lock);
101 afinfo = nf_get_afinfo(pf);
103 read_unlock(&queue_handler_lock);
108 info = kmalloc(sizeof(*info) + afinfo->route_key_size, GFP_ATOMIC);
111 printk(KERN_ERR "OOM queueing packet %p\n",
113 read_unlock(&queue_handler_lock);
118 *info = (struct nf_info) {
119 (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
121 /* If it's going away, ignore hook. */
122 if (!try_module_get(info->elem->owner)) {
123 read_unlock(&queue_handler_lock);
128 /* Bump dev refs so they don't vanish while packet is out */
129 if (indev) dev_hold(indev);
130 if (outdev) dev_hold(outdev);
132 #ifdef CONFIG_BRIDGE_NETFILTER
133 if ((*skb)->nf_bridge) {
134 physindev = (*skb)->nf_bridge->physindev;
135 if (physindev) dev_hold(physindev);
136 physoutdev = (*skb)->nf_bridge->physoutdev;
137 if (physoutdev) dev_hold(physoutdev);
140 afinfo->saveroute(*skb, info);
141 status = queue_handler[pf]->outfn(*skb, info, queuenum,
142 queue_handler[pf]->data);
144 read_unlock(&queue_handler_lock);
147 /* James M doesn't say fuck enough. */
148 if (indev) dev_put(indev);
149 if (outdev) dev_put(outdev);
150 #ifdef CONFIG_BRIDGE_NETFILTER
151 if (physindev) dev_put(physindev);
152 if (physoutdev) dev_put(physoutdev);
154 module_put(info->elem->owner);
164 void nf_reinject(struct sk_buff *skb, struct nf_info *info,
165 unsigned int verdict)
167 struct list_head *elem = &info->elem->list;
169 struct nf_afinfo *afinfo;
173 /* Release those devices we held, or Alexey will kill me. */
174 if (info->indev) dev_put(info->indev);
175 if (info->outdev) dev_put(info->outdev);
176 #ifdef CONFIG_BRIDGE_NETFILTER
177 if (skb->nf_bridge) {
178 if (skb->nf_bridge->physindev)
179 dev_put(skb->nf_bridge->physindev);
180 if (skb->nf_bridge->physoutdev)
181 dev_put(skb->nf_bridge->physoutdev);
185 /* Drop reference to owner of hook which queued us. */
186 module_put(info->elem->owner);
188 list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) {
193 if (i == &nf_hooks[info->pf][info->hook]) {
194 /* The module which sent it to userspace is gone. */
195 NFDEBUG("%s: module disappeared, dropping packet.\n",
200 /* Continue traversal iff userspace said ok... */
201 if (verdict == NF_REPEAT) {
206 if (verdict == NF_ACCEPT) {
207 afinfo = nf_get_afinfo(info->pf);
208 if (!afinfo || afinfo->reroute(&skb, info) < 0)
212 if (verdict == NF_ACCEPT) {
214 verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
216 info->indev, info->outdev, &elem,
217 info->okfn, INT_MIN);
220 switch (verdict & NF_VERDICT_MASK) {
227 if (!nf_queue(&skb, elem, info->pf, info->hook,
228 info->indev, info->outdev, info->okfn,
229 verdict >> NF_VERDICT_BITS))
239 EXPORT_SYMBOL(nf_reinject);
241 #ifdef CONFIG_PROC_FS
242 static void *seq_start(struct seq_file *seq, loff_t *pos)
250 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
260 static void seq_stop(struct seq_file *s, void *v)
265 static int seq_show(struct seq_file *s, void *v)
269 struct nf_queue_handler *qh;
271 read_lock_bh(&queue_handler_lock);
272 qh = queue_handler[*pos];
274 ret = seq_printf(s, "%2lld NONE\n", *pos);
276 ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
277 read_unlock_bh(&queue_handler_lock);
282 static struct seq_operations nfqueue_seq_ops = {
289 static int nfqueue_open(struct inode *inode, struct file *file)
291 return seq_open(file, &nfqueue_seq_ops);
294 static struct file_operations nfqueue_file_ops = {
295 .owner = THIS_MODULE,
296 .open = nfqueue_open,
299 .release = seq_release,
304 int __init netfilter_queue_init(void)
306 #ifdef CONFIG_PROC_FS
307 struct proc_dir_entry *pde;
309 pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
312 pde->proc_fops = &nfqueue_file_ops;