[net-next-2.6.git] / net / netfilter / nf_queue.c

#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 <linux/rcupdate.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 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);

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().
 */
static 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
	struct nf_afinfo *afinfo;

	/* QUEUE == DROP if noone is waiting, to be safe. */
	read_lock(&queue_handler_lock);
	if (!queue_handler[pf]) {
		read_unlock(&queue_handler_lock);
		kfree_skb(skb);
		return 1;
	}

	afinfo = nf_get_afinfo(pf);
	if (!afinfo) {
		read_unlock(&queue_handler_lock);
		kfree_skb(skb);
		return 1;
	}

	info = kmalloc(sizeof(*info) + afinfo->route_key_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
	afinfo->saveroute(skb, info);
	status = queue_handler[pf]->outfn(skb, info, queuenum,
					  queue_handler[pf]->data);

	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;
}

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)
{
	struct sk_buff *segs;

	if (!skb_is_gso(skb))
		return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
				  queuenum);

	switch (pf) {
	case AF_INET:
		skb->protocol = htons(ETH_P_IP);
		break;
	case AF_INET6:
		skb->protocol = htons(ETH_P_IPV6);
		break;
	}

	segs = skb_gso_segment(skb, 0);
	kfree_skb(skb);
	if (unlikely(IS_ERR(segs)))
		return 1;

	do {
		struct sk_buff *nskb = segs->next;

		segs->next = NULL;
		if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,
				queuenum))
			kfree_skb(segs);
		segs = nskb;
	} while (segs);
	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;
	struct nf_afinfo *afinfo;

	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 (i == &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) {
		afinfo = nf_get_afinfo(info->pf);
		if (!afinfo || afinfo->reroute(&skb, info) < 0)
			verdict = NF_DROP;
	}

	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:
	case NF_STOP:
		info->okfn(skb);
	case NF_STOLEN:
		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;
	default:
		kfree_skb(skb);
	}
	rcu_read_unlock();
	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 const 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;

	pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
	if (!pde)
		return -1;
	pde->proc_fops = &nfqueue_file_ops;
#endif
	return 0;
}
Commit	Line	Data
f6ebe77f HW	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>
bbd86b9f	7	#include <linux/seq_file.h>
7a11b984	8	#include <linux/rcupdate.h>
f6ebe77f HW	9	#include <net/protocol.h>
	10
	11	#include "nf_internals.h"
	12
601e68e1	13	/*
f6ebe77f HW	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.
	17	*/
bbd86b9f	18	static struct nf_queue_handler *queue_handler[NPROTO];
f6ebe77f HW	19
	20	static DEFINE_RWLOCK(queue_handler_lock);
	21
d72367b6 HW	22	/* return EBUSY when somebody else is registered, return EEXIST if the
d72367b6 HW	23	* same handler is registered, return 0 in case of success. */
bbd86b9f	24	int nf_register_queue_handler(int pf, struct nf_queue_handler *qh)
601e68e1	25	{
f6ebe77f HW	26	int ret;
	27
	28	if (pf >= NPROTO)
	29	return -EINVAL;
	30
	31	write_lock_bh(&queue_handler_lock);
d72367b6 HW	32	if (queue_handler[pf] == qh)
	33	ret = -EEXIST;
	34	else if (queue_handler[pf])
f6ebe77f HW	35	ret = -EBUSY;
f6ebe77f HW	36	else {
bbd86b9f	37	queue_handler[pf] = qh;
f6ebe77f HW	38	ret = 0;
	39	}
	40	write_unlock_bh(&queue_handler_lock);
	41
	42	return ret;
	43	}
	44	EXPORT_SYMBOL(nf_register_queue_handler);
	45
	46	/* The caller must flush their queue before this */
	47	int nf_unregister_queue_handler(int pf)
	48	{
	49	if (pf >= NPROTO)
	50	return -EINVAL;
	51
	52	write_lock_bh(&queue_handler_lock);
bbd86b9f	53	queue_handler[pf] = NULL;
f6ebe77f	54	write_unlock_bh(&queue_handler_lock);
601e68e1	55
f6ebe77f HW	56	return 0;
	57	}
	58	EXPORT_SYMBOL(nf_unregister_queue_handler);
	59
bbd86b9f	60	void nf_unregister_queue_handlers(struct nf_queue_handler *qh)
f6ebe77f HW	61	{
	62	int pf;
	63
	64	write_lock_bh(&queue_handler_lock);
	65	for (pf = 0; pf < NPROTO; pf++) {
bbd86b9f HW	66	if (queue_handler[pf] == qh)
bbd86b9f HW	67	queue_handler[pf] = NULL;
f6ebe77f HW	68	}
	69	write_unlock_bh(&queue_handler_lock);
	70	}
	71	EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
	72
601e68e1 YH	73	/*
601e68e1 YH	74	* Any packet that leaves via this function must come back
f6ebe77f HW	75	* through nf_reinject().
f6ebe77f HW	76	*/
394f545d PM	77	static 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)
f6ebe77f HW	84	{
	85	int status;
	86	struct nf_info *info;
	87	#ifdef CONFIG_BRIDGE_NETFILTER
	88	struct net_device *physindev = NULL;
	89	struct net_device *physoutdev = NULL;
	90	#endif
bce8032e	91	struct nf_afinfo *afinfo;
f6ebe77f HW	92
	93	/* QUEUE == DROP if noone is waiting, to be safe. */
	94	read_lock(&queue_handler_lock);
e121e9ec	95	if (!queue_handler[pf]) {
f6ebe77f	96	read_unlock(&queue_handler_lock);
394f545d	97	kfree_skb(skb);
f6ebe77f HW	98	return 1;
	99	}
	100
bce8032e PM	101	afinfo = nf_get_afinfo(pf);
	102	if (!afinfo) {
	103	read_unlock(&queue_handler_lock);
394f545d	104	kfree_skb(skb);
bce8032e PM	105	return 1;
	106	}
	107
	108	info = kmalloc(sizeof(*info) + afinfo->route_key_size, GFP_ATOMIC);
f6ebe77f HW	109	if (!info) {
	110	if (net_ratelimit())
	111	printk(KERN_ERR "OOM queueing packet %p\n",
394f545d	112	skb);
f6ebe77f	113	read_unlock(&queue_handler_lock);
394f545d	114	kfree_skb(skb);
f6ebe77f HW	115	return 1;
	116	}
	117
601e68e1	118	*info = (struct nf_info) {
f6ebe77f HW	119	(struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
	120
	121	/* If it's going away, ignore hook. */
	122	if (!try_module_get(info->elem->owner)) {
	123	read_unlock(&queue_handler_lock);
	124	kfree(info);
	125	return 0;
	126	}
	127
	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);
	131
	132	#ifdef CONFIG_BRIDGE_NETFILTER
394f545d PM	133	if (skb->nf_bridge) {
394f545d PM	134	physindev = skb->nf_bridge->physindev;
f6ebe77f	135	if (physindev) dev_hold(physindev);
394f545d	136	physoutdev = skb->nf_bridge->physoutdev;
f6ebe77f HW	137	if (physoutdev) dev_hold(physoutdev);
	138	}
	139	#endif
394f545d PM	140	afinfo->saveroute(skb, info);
394f545d PM	141	status = queue_handler[pf]->outfn(skb, info, queuenum,
bbd86b9f	142	queue_handler[pf]->data);
f6ebe77f	143
f6ebe77f HW	144	read_unlock(&queue_handler_lock);
	145
	146	if (status < 0) {
	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);
	153	#endif
	154	module_put(info->elem->owner);
	155	kfree(info);
394f545d	156	kfree_skb(skb);
f6ebe77f HW	157
	158	return 1;
	159	}
	160
	161	return 1;
	162	}
	163
394f545d PM	164	int nf_queue(struct sk_buff *skb,
	165	struct list_head *elem,
	166	int pf, unsigned int hook,
	167	struct net_device *indev,
	168	struct net_device *outdev,
	169	int (okfn)(struct sk_buff ),
	170	unsigned int queuenum)
	171	{
	172	struct sk_buff *segs;
	173
	174	if (!skb_is_gso(skb))
	175	return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
	176	queuenum);
	177
	178	switch (pf) {
	179	case AF_INET:
	180	skb->protocol = htons(ETH_P_IP);
	181	break;
	182	case AF_INET6:
	183	skb->protocol = htons(ETH_P_IPV6);
	184	break;
	185	}
	186
	187	segs = skb_gso_segment(skb, 0);
	188	kfree_skb(skb);
	189	if (unlikely(IS_ERR(segs)))
	190	return 1;
	191
	192	do {
	193	struct sk_buff *nskb = segs->next;
	194
	195	segs->next = NULL;
	196	if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,
	197	queuenum))
	198	kfree_skb(segs);
	199	segs = nskb;
	200	} while (segs);
	201	return 1;
	202	}
	203
f6ebe77f HW	204	void nf_reinject(struct sk_buff skb, struct nf_info info,
	205	unsigned int verdict)
	206	{
	207	struct list_head *elem = &info->elem->list;
	208	struct list_head *i;
bce8032e	209	struct nf_afinfo *afinfo;
f6ebe77f HW	210
	211	rcu_read_lock();
	212
	213	/* Release those devices we held, or Alexey will kill me. */
	214	if (info->indev) dev_put(info->indev);
	215	if (info->outdev) dev_put(info->outdev);
	216	#ifdef CONFIG_BRIDGE_NETFILTER
	217	if (skb->nf_bridge) {
	218	if (skb->nf_bridge->physindev)
	219	dev_put(skb->nf_bridge->physindev);
	220	if (skb->nf_bridge->physoutdev)
	221	dev_put(skb->nf_bridge->physoutdev);
	222	}
	223	#endif
	224
	225	/* Drop reference to owner of hook which queued us. */
	226	module_put(info->elem->owner);
	227
	228	list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) {
601e68e1 YH	229	if (i == elem)
	230	break;
	231	}
	232
45fe4dc0	233	if (i == &nf_hooks[info->pf][info->hook]) {
f6ebe77f HW	234	/* The module which sent it to userspace is gone. */
	235	NFDEBUG("%s: module disappeared, dropping packet.\n",
	236	__FUNCTION__);
	237	verdict = NF_DROP;
	238	}
	239
	240	/* Continue traversal iff userspace said ok... */
	241	if (verdict == NF_REPEAT) {
	242	elem = elem->prev;
	243	verdict = NF_ACCEPT;
	244	}
	245
7a11b984	246	if (verdict == NF_ACCEPT) {
bce8032e PM	247	afinfo = nf_get_afinfo(info->pf);
bce8032e PM	248	if (!afinfo \|\| afinfo->reroute(&skb, info) < 0)
7a11b984 PM	249	verdict = NF_DROP;
	250	}
	251
f6ebe77f HW	252	if (verdict == NF_ACCEPT) {
	253	next_hook:
	254	verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
601e68e1	255	&skb, info->hook,
f6ebe77f HW	256	info->indev, info->outdev, &elem,
	257	info->okfn, INT_MIN);
	258	}
	259
	260	switch (verdict & NF_VERDICT_MASK) {
	261	case NF_ACCEPT:
3bc38712	262	case NF_STOP:
f6ebe77f	263	info->okfn(skb);
3bc38712	264	case NF_STOLEN:
f6ebe77f	265	break;
f6ebe77f	266	case NF_QUEUE:
394f545d PM	267	if (!__nf_queue(skb, elem, info->pf, info->hook,
	268	info->indev, info->outdev, info->okfn,
	269	verdict >> NF_VERDICT_BITS))
f6ebe77f HW	270	goto next_hook;
f6ebe77f HW	271	break;
3bc38712 PM	272	default:
3bc38712 PM	273	kfree_skb(skb);
f6ebe77f HW	274	}
f6ebe77f HW	275	rcu_read_unlock();
f6ebe77f HW	276	kfree(info);
	277	return;
	278	}
	279	EXPORT_SYMBOL(nf_reinject);
	280
bbd86b9f HW	281	#ifdef CONFIG_PROC_FS
	282	static void seq_start(struct seq_file seq, loff_t *pos)
	283	{
	284	if (*pos >= NPROTO)
	285	return NULL;
	286
	287	return pos;
	288	}
	289
	290	static void seq_next(struct seq_file s, void v, loff_t pos)
	291	{
	292	(*pos)++;
	293
	294	if (*pos >= NPROTO)
	295	return NULL;
	296
	297	return pos;
	298	}
	299
	300	static void seq_stop(struct seq_file s, void v)
	301	{
	302
	303	}
	304
	305	static int seq_show(struct seq_file s, void v)
	306	{
	307	int ret;
	308	loff_t *pos = v;
	309	struct nf_queue_handler *qh;
	310
	311	read_lock_bh(&queue_handler_lock);
	312	qh = queue_handler[*pos];
	313	if (!qh)
	314	ret = seq_printf(s, "%2lld NONE\n", *pos);
	315	else
	316	ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
	317	read_unlock_bh(&queue_handler_lock);
	318
	319	return ret;
	320	}
	321
	322	static struct seq_operations nfqueue_seq_ops = {
	323	.start = seq_start,
	324	.next = seq_next,
	325	.stop = seq_stop,
	326	.show = seq_show,
	327	};
	328
	329	static int nfqueue_open(struct inode inode, struct file file)
	330	{
	331	return seq_open(file, &nfqueue_seq_ops);
	332	}
	333
da7071d7	334	static const struct file_operations nfqueue_file_ops = {
bbd86b9f HW	335	.owner = THIS_MODULE,
	336	.open = nfqueue_open,
	337	.read = seq_read,
	338	.llseek = seq_lseek,
	339	.release = seq_release,
	340	};
	341	#endif /* PROC_FS */
	342
	343
f6ebe77f HW	344	int __init netfilter_queue_init(void)
f6ebe77f HW	345	{
bbd86b9f HW	346	#ifdef CONFIG_PROC_FS
bbd86b9f HW	347	struct proc_dir_entry *pde;
f6ebe77f	348
bbd86b9f	349	pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
e02f7d16	350	if (!pde)
bbd86b9f	351	return -1;
bbd86b9f HW	352	pde->proc_fops = &nfqueue_file_ops;
bbd86b9f HW	353	#endif
f6ebe77f HW	354	return 0;
	355	}
	356