[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 "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_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, 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, 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(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;
	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, qh->data);

	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;
	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
	11	#include "nf_internals.h"
	12
	13	/*
	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	*/
	18	static struct nf_queue_handler *queue_handler[NPROTO];
	19
	20	static DEFINE_MUTEX(queue_handler_mutex);
	21
	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)
	25	{
	26	int ret;
	27
	28	if (pf >= NPROTO)
	29	return -EINVAL;
	30
	31	mutex_lock(&queue_handler_mutex);
	32	if (queue_handler[pf] == qh)
	33	ret = -EEXIST;
	34	else if (queue_handler[pf])
	35	ret = -EBUSY;
	36	else {
	37	rcu_assign_pointer(queue_handler[pf], qh);
	38	ret = 0;
	39	}
	40	mutex_unlock(&queue_handler_mutex);
	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, struct nf_queue_handler *qh)
	48	{
	49	if (pf >= NPROTO)
	50	return -EINVAL;
	51
	52	mutex_lock(&queue_handler_mutex);
	53	if (queue_handler[pf] != qh) {
	54	mutex_unlock(&queue_handler_mutex);
	55	return -EINVAL;
	56	}
	57
	58	rcu_assign_pointer(queue_handler[pf], NULL);
	59	mutex_unlock(&queue_handler_mutex);
	60
	61	synchronize_rcu();
	62
	63	return 0;
	64	}
	65	EXPORT_SYMBOL(nf_unregister_queue_handler);
	66
	67	void nf_unregister_queue_handlers(struct nf_queue_handler *qh)
	68	{
	69	int pf;
	70
	71	mutex_lock(&queue_handler_mutex);
	72	for (pf = 0; pf < NPROTO; pf++) {
	73	if (queue_handler[pf] == qh)
	74	rcu_assign_pointer(queue_handler[pf], NULL);
	75	}
	76	mutex_unlock(&queue_handler_mutex);
	77
	78	synchronize_rcu();
	79	}
	80	EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
	81
	82	/*
	83	* Any packet that leaves via this function must come back
	84	* through nf_reinject().
	85	*/
	86	static int __nf_queue(struct sk_buff *skb,
	87	struct list_head *elem,
	88	int pf, unsigned int hook,
	89	struct net_device *indev,
	90	struct net_device *outdev,
	91	int (okfn)(struct sk_buff ),
	92	unsigned int queuenum)
	93	{
	94	int status;
	95	struct nf_info *info;
	96	#ifdef CONFIG_BRIDGE_NETFILTER
	97	struct net_device *physindev = NULL;
	98	struct net_device *physoutdev = NULL;
	99	#endif
	100	struct nf_afinfo *afinfo;
	101	struct nf_queue_handler *qh;
	102
	103	/* QUEUE == DROP if noone is waiting, to be safe. */
	104	rcu_read_lock();
	105
	106	qh = rcu_dereference(queue_handler[pf]);
	107	if (!qh) {
	108	rcu_read_unlock();
	109	kfree_skb(skb);
	110	return 1;
	111	}
	112
	113	afinfo = nf_get_afinfo(pf);
	114	if (!afinfo) {
	115	rcu_read_unlock();
	116	kfree_skb(skb);
	117	return 1;
	118	}
	119
	120	info = kmalloc(sizeof(*info) + afinfo->route_key_size, GFP_ATOMIC);
	121	if (!info) {
	122	if (net_ratelimit())
	123	printk(KERN_ERR "OOM queueing packet %p\n",
	124	skb);
	125	rcu_read_unlock();
	126	kfree_skb(skb);
	127	return 1;
	128	}
	129
	130	*info = (struct nf_info) {
	131	(struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
	132
	133	/* If it's going away, ignore hook. */
	134	if (!try_module_get(info->elem->owner)) {
	135	rcu_read_unlock();
	136	kfree(info);
	137	return 0;
	138	}
	139
	140	/* Bump dev refs so they don't vanish while packet is out */
	141	if (indev)
	142	dev_hold(indev);
	143	if (outdev)
	144	dev_hold(outdev);
	145	#ifdef CONFIG_BRIDGE_NETFILTER
	146	if (skb->nf_bridge) {
	147	physindev = skb->nf_bridge->physindev;
	148	if (physindev)
	149	dev_hold(physindev);
	150	physoutdev = skb->nf_bridge->physoutdev;
	151	if (physoutdev)
	152	dev_hold(physoutdev);
	153	}
	154	#endif
	155	afinfo->saveroute(skb, info);
	156	status = qh->outfn(skb, info, queuenum, qh->data);
	157
	158	rcu_read_unlock();
	159
	160	if (status < 0) {
	161	/* James M doesn't say fuck enough. */
	162	if (indev)
	163	dev_put(indev);
	164	if (outdev)
	165	dev_put(outdev);
	166	#ifdef CONFIG_BRIDGE_NETFILTER
	167	if (physindev)
	168	dev_put(physindev);
	169	if (physoutdev)
	170	dev_put(physoutdev);
	171	#endif
	172	module_put(info->elem->owner);
	173	kfree(info);
	174	kfree_skb(skb);
	175
	176	return 1;
	177	}
	178
	179	return 1;
	180	}
	181
	182	int nf_queue(struct sk_buff *skb,
	183	struct list_head *elem,
	184	int pf, unsigned int hook,
	185	struct net_device *indev,
	186	struct net_device *outdev,
	187	int (okfn)(struct sk_buff ),
	188	unsigned int queuenum)
	189	{
	190	struct sk_buff *segs;
	191
	192	if (!skb_is_gso(skb))
	193	return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
	194	queuenum);
	195
	196	switch (pf) {
	197	case AF_INET:
	198	skb->protocol = htons(ETH_P_IP);
	199	break;
	200	case AF_INET6:
	201	skb->protocol = htons(ETH_P_IPV6);
	202	break;
	203	}
	204
	205	segs = skb_gso_segment(skb, 0);
	206	kfree_skb(skb);
	207	if (unlikely(IS_ERR(segs)))
	208	return 1;
	209
	210	do {
	211	struct sk_buff *nskb = segs->next;
	212
	213	segs->next = NULL;
	214	if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,
	215	queuenum))
	216	kfree_skb(segs);
	217	segs = nskb;
	218	} while (segs);
	219	return 1;
	220	}
	221
	222	void nf_reinject(struct sk_buff skb, struct nf_info info,
	223	unsigned int verdict)
	224	{
	225	struct list_head *elem = &info->elem->list;
	226	struct nf_afinfo *afinfo;
	227
	228	rcu_read_lock();
	229
	230	/* Release those devices we held, or Alexey will kill me. */
	231	if (info->indev)
	232	dev_put(info->indev);
	233	if (info->outdev)
	234	dev_put(info->outdev);
	235	#ifdef CONFIG_BRIDGE_NETFILTER
	236	if (skb->nf_bridge) {
	237	if (skb->nf_bridge->physindev)
	238	dev_put(skb->nf_bridge->physindev);
	239	if (skb->nf_bridge->physoutdev)
	240	dev_put(skb->nf_bridge->physoutdev);
	241	}
	242	#endif
	243
	244	/* Drop reference to owner of hook which queued us. */
	245	module_put(info->elem->owner);
	246
	247	/* Continue traversal iff userspace said ok... */
	248	if (verdict == NF_REPEAT) {
	249	elem = elem->prev;
	250	verdict = NF_ACCEPT;
	251	}
	252
	253	if (verdict == NF_ACCEPT) {
	254	afinfo = nf_get_afinfo(info->pf);
	255	if (!afinfo \|\| afinfo->reroute(skb, info) < 0)
	256	verdict = NF_DROP;
	257	}
	258
	259	if (verdict == NF_ACCEPT) {
	260	next_hook:
	261	verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
	262	skb, info->hook,
	263	info->indev, info->outdev, &elem,
	264	info->okfn, INT_MIN);
	265	}
	266
	267	switch (verdict & NF_VERDICT_MASK) {
	268	case NF_ACCEPT:
	269	case NF_STOP:
	270	info->okfn(skb);
	271	case NF_STOLEN:
	272	break;
	273	case NF_QUEUE:
	274	if (!__nf_queue(skb, elem, info->pf, info->hook,
	275	info->indev, info->outdev, info->okfn,
	276	verdict >> NF_VERDICT_BITS))
	277	goto next_hook;
	278	break;
	279	default:
	280	kfree_skb(skb);
	281	}
	282	rcu_read_unlock();
	283	kfree(info);
	284	return;
	285	}
	286	EXPORT_SYMBOL(nf_reinject);
	287
	288	#ifdef CONFIG_PROC_FS
	289	static void seq_start(struct seq_file seq, loff_t *pos)
	290	{
	291	if (*pos >= NPROTO)
	292	return NULL;
	293
	294	return pos;
	295	}
	296
	297	static void seq_next(struct seq_file s, void v, loff_t pos)
	298	{
	299	(*pos)++;
	300
	301	if (*pos >= NPROTO)
	302	return NULL;
	303
	304	return pos;
	305	}
	306
	307	static void seq_stop(struct seq_file s, void v)
	308	{
	309
	310	}
	311
	312	static int seq_show(struct seq_file s, void v)
	313	{
	314	int ret;
	315	loff_t *pos = v;
	316	struct nf_queue_handler *qh;
	317
	318	rcu_read_lock();
	319	qh = rcu_dereference(queue_handler[*pos]);
	320	if (!qh)
	321	ret = seq_printf(s, "%2lld NONE\n", *pos);
	322	else
	323	ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
	324	rcu_read_unlock();
	325
	326	return ret;
	327	}
	328
	329	static const struct seq_operations nfqueue_seq_ops = {
	330	.start = seq_start,
	331	.next = seq_next,
	332	.stop = seq_stop,
	333	.show = seq_show,
	334	};
	335
	336	static int nfqueue_open(struct inode inode, struct file file)
	337	{
	338	return seq_open(file, &nfqueue_seq_ops);
	339	}
	340
	341	static const struct file_operations nfqueue_file_ops = {
	342	.owner = THIS_MODULE,
	343	.open = nfqueue_open,
	344	.read = seq_read,
	345	.llseek = seq_lseek,
	346	.release = seq_release,
	347	};
	348	#endif /* PROC_FS */
	349
	350
	351	int __init netfilter_queue_init(void)
	352	{
	353	#ifdef CONFIG_PROC_FS
	354	struct proc_dir_entry *pde;
	355
	356	pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
	357	if (!pde)
	358	return -1;
	359	pde->proc_fops = &nfqueue_file_ops;
	360	#endif
	361	return 0;
	362	}
	363