[GitHub/mt8127/android_kernel_alcatel_ttab.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 <net/netfilter/nf_queue.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 const struct nf_queue_handler *queue_handler[NPROTO];

static DEFINE_MUTEX(queue_handler_mutex);

/* 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, const struct nf_queue_handler *qh)
{
	int ret;

	if (pf >= NPROTO)
		return -EINVAL;

	mutex_lock(&queue_handler_mutex);
	if (queue_handler[pf] == qh)
		ret = -EEXIST;
	else if (queue_handler[pf])
		ret = -EBUSY;
	else {
		rcu_assign_pointer(queue_handler[pf], qh);
		ret = 0;
	}
	mutex_unlock(&queue_handler_mutex);

	return ret;
}
EXPORT_SYMBOL(nf_register_queue_handler);

/* The caller must flush their queue before this */
int nf_unregister_queue_handler(int pf, const struct nf_queue_handler *qh)
{
	if (pf >= NPROTO)
		return -EINVAL;

	mutex_lock(&queue_handler_mutex);
	if (queue_handler[pf] != qh) {
		mutex_unlock(&queue_handler_mutex);
		return -EINVAL;
	}

	rcu_assign_pointer(queue_handler[pf], NULL);
	mutex_unlock(&queue_handler_mutex);

	synchronize_rcu();

	return 0;
}
EXPORT_SYMBOL(nf_unregister_queue_handler);

void nf_unregister_queue_handlers(const struct nf_queue_handler *qh)
{
	int pf;

	mutex_lock(&queue_handler_mutex);
	for (pf = 0; pf < NPROTO; pf++)  {
		if (queue_handler[pf] == qh)
			rcu_assign_pointer(queue_handler[pf], NULL);
	}
	mutex_unlock(&queue_handler_mutex);

	synchronize_rcu();
}
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;
	const struct nf_queue_handler *qh;

	/* QUEUE == DROP if noone is waiting, to be safe. */
	rcu_read_lock();

	qh = rcu_dereference(queue_handler[pf]);
	if (!qh) {
		rcu_read_unlock();
		kfree_skb(skb);
		return 1;
	}

	afinfo = nf_get_afinfo(pf);
	if (!afinfo) {
		rcu_read_unlock();
		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);
		rcu_read_unlock();
		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)) {
		rcu_read_unlock();
		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 = qh->outfn(skb, info, queuenum);

	rcu_read_unlock();

	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 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);

	/* 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;
	const struct nf_queue_handler *qh;

	rcu_read_lock();
	qh = rcu_dereference(queue_handler[*pos]);
	if (!qh)
		ret = seq_printf(s, "%2lld NONE\n", *pos);
	else
		ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
	rcu_read_unlock();

	return ret;
}

static const 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
	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>
	10	#include <net/netfilter/nf_queue.h>
	11
	12	#include "nf_internals.h"
	13
	14	/*
	15	* A queue handler may be registered for each protocol. Each is protected by
	16	* long term mutex. The handler must provide an an outfn() to accept packets
	17	* for queueing and must reinject all packets it receives, no matter what.
	18	*/
	19	static const struct nf_queue_handler *queue_handler[NPROTO];
	20
	21	static DEFINE_MUTEX(queue_handler_mutex);
	22
	23	/* return EBUSY when somebody else is registered, return EEXIST if the
	24	* same handler is registered, return 0 in case of success. */
	25	int nf_register_queue_handler(int pf, const struct nf_queue_handler *qh)
	26	{
	27	int ret;
	28
	29	if (pf >= NPROTO)
	30	return -EINVAL;
	31
	32	mutex_lock(&queue_handler_mutex);
	33	if (queue_handler[pf] == qh)
	34	ret = -EEXIST;
	35	else if (queue_handler[pf])
	36	ret = -EBUSY;
	37	else {
	38	rcu_assign_pointer(queue_handler[pf], qh);
	39	ret = 0;
	40	}
	41	mutex_unlock(&queue_handler_mutex);
	42
	43	return ret;
	44	}
	45	EXPORT_SYMBOL(nf_register_queue_handler);
	46
	47	/* The caller must flush their queue before this */
	48	int nf_unregister_queue_handler(int pf, const struct nf_queue_handler *qh)
	49	{
	50	if (pf >= NPROTO)
	51	return -EINVAL;
	52
	53	mutex_lock(&queue_handler_mutex);
	54	if (queue_handler[pf] != qh) {
	55	mutex_unlock(&queue_handler_mutex);
	56	return -EINVAL;
	57	}
	58
	59	rcu_assign_pointer(queue_handler[pf], NULL);
	60	mutex_unlock(&queue_handler_mutex);
	61
	62	synchronize_rcu();
	63
	64	return 0;
	65	}
	66	EXPORT_SYMBOL(nf_unregister_queue_handler);
	67
	68	void nf_unregister_queue_handlers(const struct nf_queue_handler *qh)
	69	{
	70	int pf;
	71
	72	mutex_lock(&queue_handler_mutex);
	73	for (pf = 0; pf < NPROTO; pf++) {
	74	if (queue_handler[pf] == qh)
	75	rcu_assign_pointer(queue_handler[pf], NULL);
	76	}
	77	mutex_unlock(&queue_handler_mutex);
	78
	79	synchronize_rcu();
	80	}
	81	EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
	82
	83	/*
	84	* Any packet that leaves via this function must come back
	85	* through nf_reinject().
	86	*/
	87	static int __nf_queue(struct sk_buff *skb,
	88	struct list_head *elem,
	89	int pf, unsigned int hook,
	90	struct net_device *indev,
	91	struct net_device *outdev,
	92	int (okfn)(struct sk_buff ),
	93	unsigned int queuenum)
	94	{
	95	int status;
	96	struct nf_info *info;
	97	#ifdef CONFIG_BRIDGE_NETFILTER
	98	struct net_device *physindev = NULL;
	99	struct net_device *physoutdev = NULL;
	100	#endif
	101	struct nf_afinfo *afinfo;
	102	const struct nf_queue_handler *qh;
	103
	104	/* QUEUE == DROP if noone is waiting, to be safe. */
	105	rcu_read_lock();
	106
	107	qh = rcu_dereference(queue_handler[pf]);
	108	if (!qh) {
	109	rcu_read_unlock();
	110	kfree_skb(skb);
	111	return 1;
	112	}
	113
	114	afinfo = nf_get_afinfo(pf);
	115	if (!afinfo) {
	116	rcu_read_unlock();
	117	kfree_skb(skb);
	118	return 1;
	119	}
	120
	121	info = kmalloc(sizeof(*info) + afinfo->route_key_size, GFP_ATOMIC);
	122	if (!info) {
	123	if (net_ratelimit())
	124	printk(KERN_ERR "OOM queueing packet %p\n",
	125	skb);
	126	rcu_read_unlock();
	127	kfree_skb(skb);
	128	return 1;
	129	}
	130
	131	*info = (struct nf_info) {
	132	(struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
	133
	134	/* If it's going away, ignore hook. */
	135	if (!try_module_get(info->elem->owner)) {
	136	rcu_read_unlock();
	137	kfree(info);
	138	return 0;
	139	}
	140
	141	/* Bump dev refs so they don't vanish while packet is out */
	142	if (indev)
	143	dev_hold(indev);
	144	if (outdev)
	145	dev_hold(outdev);
	146	#ifdef CONFIG_BRIDGE_NETFILTER
	147	if (skb->nf_bridge) {
	148	physindev = skb->nf_bridge->physindev;
	149	if (physindev)
	150	dev_hold(physindev);
	151	physoutdev = skb->nf_bridge->physoutdev;
	152	if (physoutdev)
	153	dev_hold(physoutdev);
	154	}
	155	#endif
	156	afinfo->saveroute(skb, info);
	157	status = qh->outfn(skb, info, queuenum);
	158
	159	rcu_read_unlock();
	160
	161	if (status < 0) {
	162	/* James M doesn't say fuck enough. */
	163	if (indev)
	164	dev_put(indev);
	165	if (outdev)
	166	dev_put(outdev);
	167	#ifdef CONFIG_BRIDGE_NETFILTER
	168	if (physindev)
	169	dev_put(physindev);
	170	if (physoutdev)
	171	dev_put(physoutdev);
	172	#endif
	173	module_put(info->elem->owner);
	174	kfree(info);
	175	kfree_skb(skb);
	176
	177	return 1;
	178	}
	179
	180	return 1;
	181	}
	182
	183	int nf_queue(struct sk_buff *skb,
	184	struct list_head *elem,
	185	int pf, unsigned int hook,
	186	struct net_device *indev,
	187	struct net_device *outdev,
	188	int (okfn)(struct sk_buff ),
	189	unsigned int queuenum)
	190	{
	191	struct sk_buff *segs;
	192
	193	if (!skb_is_gso(skb))
	194	return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
	195	queuenum);
	196
	197	switch (pf) {
	198	case AF_INET:
	199	skb->protocol = htons(ETH_P_IP);
	200	break;
	201	case AF_INET6:
	202	skb->protocol = htons(ETH_P_IPV6);
	203	break;
	204	}
	205
	206	segs = skb_gso_segment(skb, 0);
	207	kfree_skb(skb);
	208	if (unlikely(IS_ERR(segs)))
	209	return 1;
	210
	211	do {
	212	struct sk_buff *nskb = segs->next;
	213
	214	segs->next = NULL;
	215	if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,
	216	queuenum))
	217	kfree_skb(segs);
	218	segs = nskb;
	219	} while (segs);
	220	return 1;
	221	}
	222
	223	void nf_reinject(struct sk_buff skb, struct nf_info info,
	224	unsigned int verdict)
	225	{
	226	struct list_head *elem = &info->elem->list;
	227	struct nf_afinfo *afinfo;
	228
	229	rcu_read_lock();
	230
	231	/* Release those devices we held, or Alexey will kill me. */
	232	if (info->indev)
	233	dev_put(info->indev);
	234	if (info->outdev)
	235	dev_put(info->outdev);
	236	#ifdef CONFIG_BRIDGE_NETFILTER
	237	if (skb->nf_bridge) {
	238	if (skb->nf_bridge->physindev)
	239	dev_put(skb->nf_bridge->physindev);
	240	if (skb->nf_bridge->physoutdev)
	241	dev_put(skb->nf_bridge->physoutdev);
	242	}
	243	#endif
	244
	245	/* Drop reference to owner of hook which queued us. */
	246	module_put(info->elem->owner);
	247
	248	/* Continue traversal iff userspace said ok... */
	249	if (verdict == NF_REPEAT) {
	250	elem = elem->prev;
	251	verdict = NF_ACCEPT;
	252	}
	253
	254	if (verdict == NF_ACCEPT) {
	255	afinfo = nf_get_afinfo(info->pf);
	256	if (!afinfo \|\| afinfo->reroute(skb, info) < 0)
	257	verdict = NF_DROP;
	258	}
	259
	260	if (verdict == NF_ACCEPT) {
	261	next_hook:
	262	verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
	263	skb, info->hook,
	264	info->indev, info->outdev, &elem,
	265	info->okfn, INT_MIN);
	266	}
	267
	268	switch (verdict & NF_VERDICT_MASK) {
	269	case NF_ACCEPT:
	270	case NF_STOP:
	271	info->okfn(skb);
	272	case NF_STOLEN:
	273	break;
	274	case NF_QUEUE:
	275	if (!__nf_queue(skb, elem, info->pf, info->hook,
	276	info->indev, info->outdev, info->okfn,
	277	verdict >> NF_VERDICT_BITS))
	278	goto next_hook;
	279	break;
	280	default:
	281	kfree_skb(skb);
	282	}
	283	rcu_read_unlock();
	284	kfree(info);
	285	return;
	286	}
	287	EXPORT_SYMBOL(nf_reinject);
	288
	289	#ifdef CONFIG_PROC_FS
	290	static void seq_start(struct seq_file seq, loff_t *pos)
	291	{
	292	if (*pos >= NPROTO)
	293	return NULL;
	294
	295	return pos;
	296	}
	297
	298	static void seq_next(struct seq_file s, void v, loff_t pos)
	299	{
	300	(*pos)++;
	301
	302	if (*pos >= NPROTO)
	303	return NULL;
	304
	305	return pos;
	306	}
	307
	308	static void seq_stop(struct seq_file s, void v)
	309	{
	310
	311	}
	312
	313	static int seq_show(struct seq_file s, void v)
	314	{
	315	int ret;
	316	loff_t *pos = v;
	317	const struct nf_queue_handler *qh;
	318
	319	rcu_read_lock();
	320	qh = rcu_dereference(queue_handler[*pos]);
	321	if (!qh)
	322	ret = seq_printf(s, "%2lld NONE\n", *pos);
	323	else
	324	ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
	325	rcu_read_unlock();
	326
	327	return ret;
	328	}
	329
	330	static const struct seq_operations nfqueue_seq_ops = {
	331	.start = seq_start,
	332	.next = seq_next,
	333	.stop = seq_stop,
	334	.show = seq_show,
	335	};
	336
	337	static int nfqueue_open(struct inode inode, struct file file)
	338	{
	339	return seq_open(file, &nfqueue_seq_ops);
	340	}
	341
	342	static const struct file_operations nfqueue_file_ops = {
	343	.owner = THIS_MODULE,
	344	.open = nfqueue_open,
	345	.read = seq_read,
	346	.llseek = seq_lseek,
	347	.release = seq_release,
	348	};
	349	#endif /* PROC_FS */
	350
	351
	352	int __init netfilter_queue_init(void)
	353	{
	354	#ifdef CONFIG_PROC_FS
	355	struct proc_dir_entry *pde;
	356
	357	pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
	358	if (!pde)
	359	return -1;
	360	pde->proc_fops = &nfqueue_file_ops;
	361	#endif
	362	return 0;
	363	}
	364