[mirror_ubuntu-bionic-kernel.git] / net / x25 / x25_link.c

/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine,
 *	randomly fail to work with new releases, misbehave and/or generally
 *	screw up. It might even work.
 *
 *	This code REQUIRES 2.1.15 or higher
 *
 *	This module:
 *		This module is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	History
 *	X.25 001	Jonathan Naylor	  Started coding.
 *	X.25 002	Jonathan Naylor	  New timer architecture.
 *	mar/20/00	Daniela Squassoni Disabling/enabling of facilities
 *					  negotiation.
 *	2000-09-04	Henner Eisen	  dev_hold() / dev_put() for x25_neigh.
 */

#define pr_fmt(fmt) "X25: " fmt

#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/uaccess.h>
#include <linux/init.h>
#include <net/x25.h>

LIST_HEAD(x25_neigh_list);
DEFINE_RWLOCK(x25_neigh_list_lock);

static void x25_t20timer_expiry(struct timer_list *);

static void x25_transmit_restart_confirmation(struct x25_neigh *nb);
static void x25_transmit_restart_request(struct x25_neigh *nb);

/*
 *	Linux set/reset timer routines
 */
static inline void x25_start_t20timer(struct x25_neigh *nb)
{
	mod_timer(&nb->t20timer, jiffies + nb->t20);
}

static void x25_t20timer_expiry(struct timer_list *t)
{
	struct x25_neigh *nb = from_timer(nb, t, t20timer);

	x25_transmit_restart_request(nb);

	x25_start_t20timer(nb);
}

static inline void x25_stop_t20timer(struct x25_neigh *nb)
{
	del_timer(&nb->t20timer);
}

static inline int x25_t20timer_pending(struct x25_neigh *nb)
{
	return timer_pending(&nb->t20timer);
}

/*
 *	This handles all restart and diagnostic frames.
 */
void x25_link_control(struct sk_buff *skb, struct x25_neigh *nb,
		      unsigned short frametype)
{
	struct sk_buff *skbn;
	int confirm;

	switch (frametype) {
	case X25_RESTART_REQUEST:
		confirm = !x25_t20timer_pending(nb);
		x25_stop_t20timer(nb);
		nb->state = X25_LINK_STATE_3;
		if (confirm)
			x25_transmit_restart_confirmation(nb);
		break;

	case X25_RESTART_CONFIRMATION:
		x25_stop_t20timer(nb);
		nb->state = X25_LINK_STATE_3;
		break;

	case X25_DIAGNOSTIC:
		if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 4))
			break;

		pr_warn("diagnostic #%d - %02X %02X %02X\n",
		       skb->data[3], skb->data[4],
		       skb->data[5], skb->data[6]);
		break;

	default:
		pr_warn("received unknown %02X with LCI 000\n",
		       frametype);
		break;
	}

	if (nb->state == X25_LINK_STATE_3)
		while ((skbn = skb_dequeue(&nb->queue)) != NULL)
			x25_send_frame(skbn, nb);
}

/*
 *	This routine is called when a Restart Request is needed
 */
static void x25_transmit_restart_request(struct x25_neigh *nb)
{
	unsigned char *dptr;
	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);

	if (!skb)
		return;

	skb_reserve(skb, X25_MAX_L2_LEN);

	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);

	*dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
	*dptr++ = 0x00;
	*dptr++ = X25_RESTART_REQUEST;
	*dptr++ = 0x00;
	*dptr++ = 0;

	skb->sk = NULL;

	x25_send_frame(skb, nb);
}

/*
 * This routine is called when a Restart Confirmation is needed
 */
static void x25_transmit_restart_confirmation(struct x25_neigh *nb)
{
	unsigned char *dptr;
	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN;
	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);

	if (!skb)
		return;

	skb_reserve(skb, X25_MAX_L2_LEN);

	dptr = skb_put(skb, X25_STD_MIN_LEN);

	*dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
	*dptr++ = 0x00;
	*dptr++ = X25_RESTART_CONFIRMATION;

	skb->sk = NULL;

	x25_send_frame(skb, nb);
}

/*
 *	This routine is called when a Clear Request is needed outside of the context
 *	of a connected socket.
 */
void x25_transmit_clear_request(struct x25_neigh *nb, unsigned int lci,
				unsigned char cause)
{
	unsigned char *dptr;
	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);

	if (!skb)
		return;

	skb_reserve(skb, X25_MAX_L2_LEN);

	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);

	*dptr++ = ((lci >> 8) & 0x0F) | (nb->extended ?
					 X25_GFI_EXTSEQ :
					 X25_GFI_STDSEQ);
	*dptr++ = (lci >> 0) & 0xFF;
	*dptr++ = X25_CLEAR_REQUEST;
	*dptr++ = cause;
	*dptr++ = 0x00;

	skb->sk = NULL;

	x25_send_frame(skb, nb);
}

void x25_transmit_link(struct sk_buff *skb, struct x25_neigh *nb)
{
	switch (nb->state) {
	case X25_LINK_STATE_0:
		skb_queue_tail(&nb->queue, skb);
		nb->state = X25_LINK_STATE_1;
		x25_establish_link(nb);
		break;
	case X25_LINK_STATE_1:
	case X25_LINK_STATE_2:
		skb_queue_tail(&nb->queue, skb);
		break;
	case X25_LINK_STATE_3:
		x25_send_frame(skb, nb);
		break;
	}
}

/*
 *	Called when the link layer has become established.
 */
void x25_link_established(struct x25_neigh *nb)
{
	switch (nb->state) {
	case X25_LINK_STATE_0:
		nb->state = X25_LINK_STATE_2;
		break;
	case X25_LINK_STATE_1:
		x25_transmit_restart_request(nb);
		nb->state = X25_LINK_STATE_2;
		x25_start_t20timer(nb);
		break;
	}
}

/*
 *	Called when the link layer has terminated, or an establishment
 *	request has failed.
 */

void x25_link_terminated(struct x25_neigh *nb)
{
	nb->state = X25_LINK_STATE_0;
	/* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */
	x25_kill_by_neigh(nb);
}

/*
 *	Add a new device.
 */
void x25_link_device_up(struct net_device *dev)
{
	struct x25_neigh *nb = kmalloc(sizeof(*nb), GFP_ATOMIC);

	if (!nb)
		return;

	skb_queue_head_init(&nb->queue);
	timer_setup(&nb->t20timer, x25_t20timer_expiry, 0);

	dev_hold(dev);
	nb->dev      = dev;
	nb->state    = X25_LINK_STATE_0;
	nb->extended = 0;
	/*
	 * Enables negotiation
	 */
	nb->global_facil_mask = X25_MASK_REVERSE |
				       X25_MASK_THROUGHPUT |
				       X25_MASK_PACKET_SIZE |
				       X25_MASK_WINDOW_SIZE;
	nb->t20      = sysctl_x25_restart_request_timeout;
	refcount_set(&nb->refcnt, 1);

	write_lock_bh(&x25_neigh_list_lock);
	list_add(&nb->node, &x25_neigh_list);
	write_unlock_bh(&x25_neigh_list_lock);
}

/**
 *	__x25_remove_neigh - remove neighbour from x25_neigh_list
 *	@nb - neigh to remove
 *
 *	Remove neighbour from x25_neigh_list. If it was there.
 *	Caller must hold x25_neigh_list_lock.
 */
static void __x25_remove_neigh(struct x25_neigh *nb)
{
	skb_queue_purge(&nb->queue);
	x25_stop_t20timer(nb);

	if (nb->node.next) {
		list_del(&nb->node);
		x25_neigh_put(nb);
	}
}

/*
 *	A device has been removed, remove its links.
 */
void x25_link_device_down(struct net_device *dev)
{
	struct x25_neigh *nb;
	struct list_head *entry, *tmp;

	write_lock_bh(&x25_neigh_list_lock);

	list_for_each_safe(entry, tmp, &x25_neigh_list) {
		nb = list_entry(entry, struct x25_neigh, node);

		if (nb->dev == dev) {
			__x25_remove_neigh(nb);
			dev_put(dev);
		}
	}

	write_unlock_bh(&x25_neigh_list_lock);
}

/*
 *	Given a device, return the neighbour address.
 */
struct x25_neigh *x25_get_neigh(struct net_device *dev)
{
	struct x25_neigh *nb, *use = NULL;
	struct list_head *entry;

	read_lock_bh(&x25_neigh_list_lock);
	list_for_each(entry, &x25_neigh_list) {
		nb = list_entry(entry, struct x25_neigh, node);

		if (nb->dev == dev) {
			use = nb;
			break;
		}
	}

	if (use)
		x25_neigh_hold(use);
	read_unlock_bh(&x25_neigh_list_lock);
	return use;
}

/*
 *	Handle the ioctls that control the subscription functions.
 */
int x25_subscr_ioctl(unsigned int cmd, void __user *arg)
{
	struct x25_subscrip_struct x25_subscr;
	struct x25_neigh *nb;
	struct net_device *dev;
	int rc = -EINVAL;

	if (cmd != SIOCX25GSUBSCRIP && cmd != SIOCX25SSUBSCRIP)
		goto out;

	rc = -EFAULT;
	if (copy_from_user(&x25_subscr, arg, sizeof(x25_subscr)))
		goto out;

	rc = -EINVAL;
	if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
		goto out;

	if ((nb = x25_get_neigh(dev)) == NULL)
		goto out_dev_put;

	dev_put(dev);

	if (cmd == SIOCX25GSUBSCRIP) {
		read_lock_bh(&x25_neigh_list_lock);
		x25_subscr.extended	     = nb->extended;
		x25_subscr.global_facil_mask = nb->global_facil_mask;
		read_unlock_bh(&x25_neigh_list_lock);
		rc = copy_to_user(arg, &x25_subscr,
				  sizeof(x25_subscr)) ? -EFAULT : 0;
	} else {
		rc = -EINVAL;
		if (!(x25_subscr.extended && x25_subscr.extended != 1)) {
			rc = 0;
			write_lock_bh(&x25_neigh_list_lock);
			nb->extended	     = x25_subscr.extended;
			nb->global_facil_mask = x25_subscr.global_facil_mask;
			write_unlock_bh(&x25_neigh_list_lock);
		}
	}
	x25_neigh_put(nb);
out:
	return rc;
out_dev_put:
	dev_put(dev);
	goto out;
}


/*
 *	Release all memory associated with X.25 neighbour structures.
 */
void __exit x25_link_free(void)
{
	struct x25_neigh *nb;
	struct list_head *entry, *tmp;

	write_lock_bh(&x25_neigh_list_lock);

	list_for_each_safe(entry, tmp, &x25_neigh_list) {
		struct net_device *dev;

		nb = list_entry(entry, struct x25_neigh, node);
		dev = nb->dev;
		__x25_remove_neigh(nb);
		dev_put(dev);
	}
	write_unlock_bh(&x25_neigh_list_lock);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* X.25 Packet Layer release 002
	3	*
	4	* This is ALPHA test software. This code may break your machine,
	5	* randomly fail to work with new releases, misbehave and/or generally
f8e1d201	6	* screw up. It might even work.
1da177e4 LT	7	*
	8	* This code REQUIRES 2.1.15 or higher
	9	*
	10	* This module:
	11	* This module is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*
	16	* History
	17	* X.25 001 Jonathan Naylor Started coding.
	18	* X.25 002 Jonathan Naylor New timer architecture.
f8e1d201	19	* mar/20/00 Daniela Squassoni Disabling/enabling of facilities
1da177e4 LT	20	* negotiation.
	21	* 2000-09-04 Henner Eisen dev_hold() / dev_put() for x25_neigh.
	22	*/
	23
b73e9e3c	24	#define pr_fmt(fmt) "X25: " fmt
b73e9e3c	25
1da177e4 LT	26	#include <linux/kernel.h>
	27	#include <linux/jiffies.h>
	28	#include <linux/timer.h>
5a0e3ad6	29	#include <linux/slab.h>
1da177e4 LT	30	#include <linux/netdevice.h>
1da177e4 LT	31	#include <linux/skbuff.h>
7c0f6ba6	32	#include <linux/uaccess.h>
1da177e4 LT	33	#include <linux/init.h>
	34	#include <net/x25.h>
	35
5595a1a5	36	LIST_HEAD(x25_neigh_list);
5595a1a5	37	DEFINE_RWLOCK(x25_neigh_list_lock);
1da177e4	38
e99e88a9	39	static void x25_t20timer_expiry(struct timer_list *);
1da177e4 LT	40
	41	static void x25_transmit_restart_confirmation(struct x25_neigh *nb);
	42	static void x25_transmit_restart_request(struct x25_neigh *nb);
	43
	44	/*
	45	* Linux set/reset timer routines
	46	*/
	47	static inline void x25_start_t20timer(struct x25_neigh *nb)
	48	{
	49	mod_timer(&nb->t20timer, jiffies + nb->t20);
	50	}
	51
e99e88a9	52	static void x25_t20timer_expiry(struct timer_list *t)
1da177e4	53	{
e99e88a9	54	struct x25_neigh *nb = from_timer(nb, t, t20timer);
1da177e4 LT	55
	56	x25_transmit_restart_request(nb);
	57
	58	x25_start_t20timer(nb);
	59	}
	60
	61	static inline void x25_stop_t20timer(struct x25_neigh *nb)
	62	{
	63	del_timer(&nb->t20timer);
	64	}
	65
	66	static inline int x25_t20timer_pending(struct x25_neigh *nb)
	67	{
	68	return timer_pending(&nb->t20timer);
	69	}
	70
	71	/*
	72	* This handles all restart and diagnostic frames.
	73	*/
	74	void x25_link_control(struct sk_buff skb, struct x25_neigh nb,
	75	unsigned short frametype)
	76	{
	77	struct sk_buff *skbn;
	78	int confirm;
	79
	80	switch (frametype) {
fddc5f3e JP	81	case X25_RESTART_REQUEST:
	82	confirm = !x25_t20timer_pending(nb);
	83	x25_stop_t20timer(nb);
	84	nb->state = X25_LINK_STATE_3;
	85	if (confirm)
	86	x25_transmit_restart_confirmation(nb);
	87	break;
	88
	89	case X25_RESTART_CONFIRMATION:
	90	x25_stop_t20timer(nb);
	91	nb->state = X25_LINK_STATE_3;
	92	break;
	93
	94	case X25_DIAGNOSTIC:
cb101ed2 MD	95	if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 4))
	96	break;
	97
b73e9e3c	98	pr_warn("diagnostic #%d - %02X %02X %02X\n",
fddc5f3e JP	99	skb->data[3], skb->data[4],
	100	skb->data[5], skb->data[6]);
	101	break;
	102
	103	default:
b73e9e3c	104	pr_warn("received unknown %02X with LCI 000\n",
fddc5f3e JP	105	frametype);
fddc5f3e JP	106	break;
1da177e4 LT	107	}
	108
	109	if (nb->state == X25_LINK_STATE_3)
	110	while ((skbn = skb_dequeue(&nb->queue)) != NULL)
	111	x25_send_frame(skbn, nb);
	112	}
	113
	114	/*
	115	* This routine is called when a Restart Request is needed
	116	*/
	117	static void x25_transmit_restart_request(struct x25_neigh *nb)
	118	{
	119	unsigned char *dptr;
	120	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
	121	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
	122
	123	if (!skb)
	124	return;
	125
	126	skb_reserve(skb, X25_MAX_L2_LEN);
	127
	128	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
	129
	130	*dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
	131	*dptr++ = 0x00;
	132	*dptr++ = X25_RESTART_REQUEST;
	133	*dptr++ = 0x00;
	134	*dptr++ = 0;
	135
	136	skb->sk = NULL;
	137
	138	x25_send_frame(skb, nb);
	139	}
	140
	141	/*
	142	* This routine is called when a Restart Confirmation is needed
	143	*/
	144	static void x25_transmit_restart_confirmation(struct x25_neigh *nb)
	145	{
	146	unsigned char *dptr;
	147	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN;
	148	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
	149
	150	if (!skb)
	151	return;
	152
	153	skb_reserve(skb, X25_MAX_L2_LEN);
	154
	155	dptr = skb_put(skb, X25_STD_MIN_LEN);
	156
	157	*dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
	158	*dptr++ = 0x00;
	159	*dptr++ = X25_RESTART_CONFIRMATION;
	160
	161	skb->sk = NULL;
	162
	163	x25_send_frame(skb, nb);
	164	}
	165
	166	/*
	167	* This routine is called when a Clear Request is needed outside of the context
	168	* of a connected socket.
	169	*/
	170	void x25_transmit_clear_request(struct x25_neigh *nb, unsigned int lci,
171	unsigned char cause)
172	{
173	unsigned char *dptr;
174	int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
175	struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
176
177	if (!skb)
178	return;
179
180	skb_reserve(skb, X25_MAX_L2_LEN);
181
182	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
183
184	*dptr++ = ((lci >> 8) & 0x0F) \| (nb->extended ?
185	X25_GFI_EXTSEQ :
186	X25_GFI_STDSEQ);
187	*dptr++ = (lci >> 0) & 0xFF;
188	*dptr++ = X25_CLEAR_REQUEST;
189	*dptr++ = cause;
190	*dptr++ = 0x00;
191
192	skb->sk = NULL;
193
194	x25_send_frame(skb, nb);
195	}
196
197	void x25_transmit_link(struct sk_buff skb, struct x25_neigh nb)
198	{
199	switch (nb->state) {
fddc5f3e JP	200	case X25_LINK_STATE_0:
	201	skb_queue_tail(&nb->queue, skb);
	202	nb->state = X25_LINK_STATE_1;
	203	x25_establish_link(nb);
	204	break;
	205	case X25_LINK_STATE_1:
	206	case X25_LINK_STATE_2:
	207	skb_queue_tail(&nb->queue, skb);
	208	break;
	209	case X25_LINK_STATE_3:
	210	x25_send_frame(skb, nb);
	211	break;
1da177e4 LT	212	}
	213	}
	214
	215	/*
	216	* Called when the link layer has become established.
	217	*/
	218	void x25_link_established(struct x25_neigh *nb)
	219	{
	220	switch (nb->state) {
fddc5f3e JP	221	case X25_LINK_STATE_0:
	222	nb->state = X25_LINK_STATE_2;
	223	break;
	224	case X25_LINK_STATE_1:
	225	x25_transmit_restart_request(nb);
	226	nb->state = X25_LINK_STATE_2;
	227	x25_start_t20timer(nb);
	228	break;
1da177e4 LT	229	}
	230	}
	231
	232	/*
	233	* Called when the link layer has terminated, or an establishment
	234	* request has failed.
	235	*/
	236
	237	void x25_link_terminated(struct x25_neigh *nb)
	238	{
	239	nb->state = X25_LINK_STATE_0;
	240	/* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */
	241	x25_kill_by_neigh(nb);
	242	}
	243
	244	/*
	245	* Add a new device.
	246	*/
	247	void x25_link_device_up(struct net_device *dev)
	248	{
	249	struct x25_neigh nb = kmalloc(sizeof(nb), GFP_ATOMIC);
	250
	251	if (!nb)
	252	return;
	253
	254	skb_queue_head_init(&nb->queue);
e99e88a9	255	timer_setup(&nb->t20timer, x25_t20timer_expiry, 0);
1da177e4 LT	256
	257	dev_hold(dev);
	258	nb->dev = dev;
	259	nb->state = X25_LINK_STATE_0;
	260	nb->extended = 0;
	261	/*
	262	* Enables negotiation
	263	*/
	264	nb->global_facil_mask = X25_MASK_REVERSE \|
	265	X25_MASK_THROUGHPUT \|
	266	X25_MASK_PACKET_SIZE \|
	267	X25_MASK_WINDOW_SIZE;
	268	nb->t20 = sysctl_x25_restart_request_timeout;
5534a51a	269	refcount_set(&nb->refcnt, 1);
1da177e4 LT	270
	271	write_lock_bh(&x25_neigh_list_lock);
	272	list_add(&nb->node, &x25_neigh_list);
	273	write_unlock_bh(&x25_neigh_list_lock);
	274	}
	275
	276	/**
	277	* __x25_remove_neigh - remove neighbour from x25_neigh_list
	278	* @nb - neigh to remove
	279	*
	280	* Remove neighbour from x25_neigh_list. If it was there.
	281	* Caller must hold x25_neigh_list_lock.
	282	*/
	283	static void __x25_remove_neigh(struct x25_neigh *nb)
	284	{
	285	skb_queue_purge(&nb->queue);
	286	x25_stop_t20timer(nb);
	287
	288	if (nb->node.next) {
	289	list_del(&nb->node);
	290	x25_neigh_put(nb);
	291	}
	292	}
	293
	294	/*
	295	* A device has been removed, remove its links.
	296	*/
	297	void x25_link_device_down(struct net_device *dev)
	298	{
	299	struct x25_neigh *nb;
	300	struct list_head entry, tmp;
	301
	302	write_lock_bh(&x25_neigh_list_lock);
	303
	304	list_for_each_safe(entry, tmp, &x25_neigh_list) {
	305	nb = list_entry(entry, struct x25_neigh, node);
	306
	307	if (nb->dev == dev) {
	308	__x25_remove_neigh(nb);
	309	dev_put(dev);
	310	}
	311	}
	312
	313	write_unlock_bh(&x25_neigh_list_lock);
	314	}
	315
	316	/*
	317	* Given a device, return the neighbour address.
	318	*/
	319	struct x25_neigh x25_get_neigh(struct net_device dev)
	320	{
	321	struct x25_neigh nb, use = NULL;
	322	struct list_head *entry;
	323
	324	read_lock_bh(&x25_neigh_list_lock);
	325	list_for_each(entry, &x25_neigh_list) {
	326	nb = list_entry(entry, struct x25_neigh, node);
	327
	328	if (nb->dev == dev) {
	329	use = nb;
	330	break;
	331	}
	332	}
	333
334	if (use)
335	x25_neigh_hold(use);
336	read_unlock_bh(&x25_neigh_list_lock);
337	return use;
338	}
339
340	/*
341	* Handle the ioctls that control the subscription functions.
342	*/
343	int x25_subscr_ioctl(unsigned int cmd, void __user *arg)
344	{
345	struct x25_subscrip_struct x25_subscr;
346	struct x25_neigh *nb;
347	struct net_device *dev;
348	int rc = -EINVAL;
349
350	if (cmd != SIOCX25GSUBSCRIP && cmd != SIOCX25SSUBSCRIP)
351	goto out;
352
353	rc = -EFAULT;
354	if (copy_from_user(&x25_subscr, arg, sizeof(x25_subscr)))
355	goto out;
356
357	rc = -EINVAL;
358	if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
359	goto out;
360
361	if ((nb = x25_get_neigh(dev)) == NULL)
362	goto out_dev_put;
363
364	dev_put(dev);
365
366	if (cmd == SIOCX25GSUBSCRIP) {
5595a1a5	367	read_lock_bh(&x25_neigh_list_lock);
1da177e4 LT	368	x25_subscr.extended = nb->extended;
1da177e4 LT	369	x25_subscr.global_facil_mask = nb->global_facil_mask;
5595a1a5	370	read_unlock_bh(&x25_neigh_list_lock);
1da177e4 LT	371	rc = copy_to_user(arg, &x25_subscr,
	372	sizeof(x25_subscr)) ? -EFAULT : 0;
	373	} else {
	374	rc = -EINVAL;
	375	if (!(x25_subscr.extended && x25_subscr.extended != 1)) {
	376	rc = 0;
5595a1a5	377	write_lock_bh(&x25_neigh_list_lock);
1da177e4 LT	378	nb->extended = x25_subscr.extended;
1da177e4 LT	379	nb->global_facil_mask = x25_subscr.global_facil_mask;
5595a1a5	380	write_unlock_bh(&x25_neigh_list_lock);
1da177e4 LT	381	}
	382	}
	383	x25_neigh_put(nb);
	384	out:
	385	return rc;
	386	out_dev_put:
	387	dev_put(dev);
	388	goto out;
	389	}
	390
	391
	392	/*
	393	* Release all memory associated with X.25 neighbour structures.
	394	*/
	395	void __exit x25_link_free(void)
	396	{
	397	struct x25_neigh *nb;
	398	struct list_head entry, tmp;
	399
	400	write_lock_bh(&x25_neigh_list_lock);
	401
	402	list_for_each_safe(entry, tmp, &x25_neigh_list) {
96642d42 DM	403	struct net_device *dev;
96642d42 DM	404
1da177e4	405	nb = list_entry(entry, struct x25_neigh, node);
96642d42	406	dev = nb->dev;
1da177e4	407	__x25_remove_neigh(nb);
96642d42	408	dev_put(dev);
1da177e4 LT	409	}
	410	write_unlock_bh(&x25_neigh_list_lock);
	411	}