1 files changed, 343 insertions, 0 deletions
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
new file mode 100644
index 00000000000..d10d552d9c4
--- /dev/null
+++ b/net/netfilter/nf_queue.c
@@ -0,0 +1,343 @@
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter.h>
+#include <linux/seq_file.h>
+#include <net/protocol.h>
+
+#include "nf_internals.h"
+
+/* 
+ * A queue handler may be registered for each protocol.  Each is protected by
+ * long term mutex.  The handler must provide an an outfn() to accept packets
+ * for queueing and must reinject all packets it receives, no matter what.
+ */
+static struct nf_queue_handler *queue_handler[NPROTO];
+static struct nf_queue_rerouter *queue_rerouter;
+
+static DEFINE_RWLOCK(queue_handler_lock);
+
+/* return EBUSY when somebody else is registered, return EEXIST if the
+ * same handler is registered, return 0 in case of success. */
+int nf_register_queue_handler(int pf, struct nf_queue_handler *qh)
+{      
+	int ret;
+
+	if (pf >= NPROTO)
+		return -EINVAL;
+
+	write_lock_bh(&queue_handler_lock);
+	if (queue_handler[pf] == qh)
+		ret = -EEXIST;
+	else if (queue_handler[pf])
+		ret = -EBUSY;
+	else {
+		queue_handler[pf] = qh;
+		ret = 0;
+	}
+	write_unlock_bh(&queue_handler_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(nf_register_queue_handler);
+
+/* The caller must flush their queue before this */
+int nf_unregister_queue_handler(int pf)
+{
+	if (pf >= NPROTO)
+		return -EINVAL;
+
+	write_lock_bh(&queue_handler_lock);
+	queue_handler[pf] = NULL;
+	write_unlock_bh(&queue_handler_lock);
+	
+	return 0;
+}
+EXPORT_SYMBOL(nf_unregister_queue_handler);
+
+int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer)
+{
+	if (pf >= NPROTO)
+		return -EINVAL;
+
+	write_lock_bh(&queue_handler_lock);
+	memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf]));
+	write_unlock_bh(&queue_handler_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_register_queue_rerouter);
+
+int nf_unregister_queue_rerouter(int pf)
+{
+	if (pf >= NPROTO)
+		return -EINVAL;
+
+	write_lock_bh(&queue_handler_lock);
+	memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf]));
+	write_unlock_bh(&queue_handler_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter);
+
+void nf_unregister_queue_handlers(struct nf_queue_handler *qh)
+{
+	int pf;
+
+	write_lock_bh(&queue_handler_lock);
+	for (pf = 0; pf < NPROTO; pf++)  {
+		if (queue_handler[pf] == qh)
+			queue_handler[pf] = NULL;
+	}
+	write_unlock_bh(&queue_handler_lock);
+}
+EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
+
+/* 
+ * Any packet that leaves via this function must come back 
+ * through nf_reinject().
+ */
+int nf_queue(struct sk_buff **skb, 
+	     struct list_head *elem, 
+	     int pf, unsigned int hook,
+	     struct net_device *indev,
+	     struct net_device *outdev,
+	     int (*okfn)(struct sk_buff *),
+	     unsigned int queuenum)
+{
+	int status;
+	struct nf_info *info;
+#ifdef CONFIG_BRIDGE_NETFILTER
+	struct net_device *physindev = NULL;
+	struct net_device *physoutdev = NULL;
+#endif
+
+	/* QUEUE == DROP if noone is waiting, to be safe. */
+	read_lock(&queue_handler_lock);
+	if (!queue_handler[pf]->outfn) {
+		read_unlock(&queue_handler_lock);
+		kfree_skb(*skb);
+		return 1;
+	}
+
+	info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC);
+	if (!info) {
+		if (net_ratelimit())
+			printk(KERN_ERR "OOM queueing packet %p\n",
+			       *skb);
+		read_unlock(&queue_handler_lock);
+		kfree_skb(*skb);
+		return 1;
+	}
+
+	*info = (struct nf_info) { 
+		(struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
+
+	/* If it's going away, ignore hook. */
+	if (!try_module_get(info->elem->owner)) {
+		read_unlock(&queue_handler_lock);
+		kfree(info);
+		return 0;
+	}
+
+	/* Bump dev refs so they don't vanish while packet is out */
+	if (indev) dev_hold(indev);
+	if (outdev) dev_hold(outdev);
+
+#ifdef CONFIG_BRIDGE_NETFILTER
+	if ((*skb)->nf_bridge) {
+		physindev = (*skb)->nf_bridge->physindev;
+		if (physindev) dev_hold(physindev);
+		physoutdev = (*skb)->nf_bridge->physoutdev;
+		if (physoutdev) dev_hold(physoutdev);
+	}
+#endif
+	if (queue_rerouter[pf].save)
+		queue_rerouter[pf].save(*skb, info);
+
+	status = queue_handler[pf]->outfn(*skb, info, queuenum,
+					  queue_handler[pf]->data);
+
+	if (status >= 0 && queue_rerouter[pf].reroute)
+		status = queue_rerouter[pf].reroute(skb, info);
+
+	read_unlock(&queue_handler_lock);
+
+	if (status < 0) {
+		/* James M doesn't say fuck enough. */
+		if (indev) dev_put(indev);
+		if (outdev) dev_put(outdev);
+#ifdef CONFIG_BRIDGE_NETFILTER
+		if (physindev) dev_put(physindev);
+		if (physoutdev) dev_put(physoutdev);
+#endif
+		module_put(info->elem->owner);
+		kfree(info);
+		kfree_skb(*skb);
+
+		return 1;
+	}
+
+	return 1;
+}
+
+void nf_reinject(struct sk_buff *skb, struct nf_info *info,
+		 unsigned int verdict)
+{
+	struct list_head *elem = &info->elem->list;
+	struct list_head *i;
+
+	rcu_read_lock();
+
+	/* Release those devices we held, or Alexey will kill me. */
+	if (info->indev) dev_put(info->indev);
+	if (info->outdev) dev_put(info->outdev);
+#ifdef CONFIG_BRIDGE_NETFILTER
+	if (skb->nf_bridge) {
+		if (skb->nf_bridge->physindev)
+			dev_put(skb->nf_bridge->physindev);
+		if (skb->nf_bridge->physoutdev)
+			dev_put(skb->nf_bridge->physoutdev);
+	}
+#endif
+
+	/* Drop reference to owner of hook which queued us. */
+	module_put(info->elem->owner);
+
+	list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) {
+		if (i == elem) 
+  			break;
+  	}
+  
+	if (elem == &nf_hooks[info->pf][info->hook]) {
+		/* The module which sent it to userspace is gone. */
+		NFDEBUG("%s: module disappeared, dropping packet.\n",
+			__FUNCTION__);
+		verdict = NF_DROP;
+	}
+
+	/* Continue traversal iff userspace said ok... */
+	if (verdict == NF_REPEAT) {
+		elem = elem->prev;
+		verdict = NF_ACCEPT;
+	}
+
+	if (verdict == NF_ACCEPT) {
+	next_hook:
+		verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
+				     &skb, info->hook, 
+				     info->indev, info->outdev, &elem,
+				     info->okfn, INT_MIN);
+	}
+
+	switch (verdict & NF_VERDICT_MASK) {
+	case NF_ACCEPT:
+		info->okfn(skb);
+		break;
+
+	case NF_QUEUE:
+		if (!nf_queue(&skb, elem, info->pf, info->hook, 
+			      info->indev, info->outdev, info->okfn,
+			      verdict >> NF_VERDICT_BITS))
+			goto next_hook;
+		break;
+	}
+	rcu_read_unlock();
+
+	if (verdict == NF_DROP)
+		kfree_skb(skb);
+
+	kfree(info);
+	return;
+}
+EXPORT_SYMBOL(nf_reinject);
+
+#ifdef CONFIG_PROC_FS
+static void *seq_start(struct seq_file *seq, loff_t *pos)
+{
+	if (*pos >= NPROTO)
+		return NULL;
+
+	return pos;
+}
+
+static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	(*pos)++;
+
+	if (*pos >= NPROTO)
+		return NULL;
+
+	return pos;
+}
+
+static void seq_stop(struct seq_file *s, void *v)
+{
+
+}
+
+static int seq_show(struct seq_file *s, void *v)
+{
+	int ret;
+	loff_t *pos = v;
+	struct nf_queue_handler *qh;
+
+	read_lock_bh(&queue_handler_lock);
+	qh = queue_handler[*pos];
+	if (!qh)
+		ret = seq_printf(s, "%2lld NONE\n", *pos);
+	else
+		ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
+	read_unlock_bh(&queue_handler_lock);
+
+	return ret;
+}
+
+static struct seq_operations nfqueue_seq_ops = {
+	.start	= seq_start,
+	.next	= seq_next,
+	.stop	= seq_stop,
+	.show	= seq_show,
+};
+
+static int nfqueue_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &nfqueue_seq_ops);
+}
+
+static struct file_operations nfqueue_file_ops = {
+	.owner	 = THIS_MODULE,
+	.open	 = nfqueue_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release,
+};
+#endif /* PROC_FS */
+
+
+int __init netfilter_queue_init(void)
+{
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *pde;
+#endif
+	queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter),
+				 GFP_KERNEL);
+	if (!queue_rerouter)
+		return -ENOMEM;
+
+#ifdef CONFIG_PROC_FS
+	pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
+	if (!pde) {
+		kfree(queue_rerouter);
+		return -1;
+	}
+	pde->proc_fops = &nfqueue_file_ops;
+#endif
+	memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter));
+
+	return 0;
+}
+