[linux.git] / net / x25 / x25_in.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	  Centralised disconnection code.
 *					  New timer architecture.
 *	2000-03-20	Daniela Squassoni Disabling/enabling of facilities
 *					  negotiation.
 *	2000-11-10	Henner Eisen	  Check and reset for out-of-sequence
 *					  i-frames.
 */

#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/x25.h>

static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
{
	struct sk_buff *skbo, *skbn = skb;
	struct x25_sock *x25 = x25_sk(sk);

	if (more) {
		x25->fraglen += skb->len;
		skb_queue_tail(&x25->fragment_queue, skb);
		skb_set_owner_r(skb, sk);
		return 0;
	}

	if (!more && x25->fraglen > 0) {	/* End of fragment */
		int len = x25->fraglen + skb->len;

		if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){
			kfree_skb(skb);
			return 1;
		}

		skb_queue_tail(&x25->fragment_queue, skb);

		skb_reset_transport_header(skbn);

		skbo = skb_dequeue(&x25->fragment_queue);
		skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len),
					  skbo->len);
		kfree_skb(skbo);

		while ((skbo =
			skb_dequeue(&x25->fragment_queue)) != NULL) {
			skb_pull(skbo, (x25->neighbour->extended) ?
					X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
			skb_copy_from_linear_data(skbo,
						  skb_put(skbn, skbo->len),
						  skbo->len);
			kfree_skb(skbo);
		}

		x25->fraglen = 0;
	}

	skb_set_owner_r(skbn, sk);
	skb_queue_tail(&sk->sk_receive_queue, skbn);
	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_data_ready(sk, skbn->len);

	return 0;
}

/*
 * State machine for state 1, Awaiting Call Accepted State.
 * The handling of the timer(s) is in file x25_timer.c.
 * Handling of state 0 and connection release is in af_x25.c.
 */
static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	struct x25_address source_addr, dest_addr;
	int len;

	switch (frametype) {
		case X25_CALL_ACCEPTED: {
			struct x25_sock *x25 = x25_sk(sk);

			x25_stop_timer(sk);
			x25->condition = 0x00;
			x25->vs        = 0;
			x25->va        = 0;
			x25->vr        = 0;
			x25->vl        = 0;
			x25->state     = X25_STATE_3;
			sk->sk_state   = TCP_ESTABLISHED;
			/*
			 *	Parse the data in the frame.
			 */
			skb_pull(skb, X25_STD_MIN_LEN);

			len = x25_parse_address_block(skb, &source_addr,
						&dest_addr);
			if (len > 0)
				skb_pull(skb, len);

			len = x25_parse_facilities(skb, &x25->facilities,
						&x25->dte_facilities,
						&x25->vc_facil_mask);
			if (len > 0)
				skb_pull(skb, len);
			else
				return -1;
			/*
			 *	Copy any Call User Data.
			 */
			if (skb->len > 0) {
				skb_copy_from_linear_data(skb,
					      x25->calluserdata.cuddata,
					      skb->len);
				x25->calluserdata.cudlength = skb->len;
			}
			if (!sock_flag(sk, SOCK_DEAD))
				sk->sk_state_change(sk);
			break;
		}
		case X25_CLEAR_REQUEST:
			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
			x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
			break;

		default:
			break;
	}

	return 0;
}

/*
 * State machine for state 2, Awaiting Clear Confirmation State.
 * The handling of the timer(s) is in file x25_timer.c
 * Handling of state 0 and connection release is in af_x25.c.
 */
static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	switch (frametype) {

		case X25_CLEAR_REQUEST:
			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
			break;

		case X25_CLEAR_CONFIRMATION:
			x25_disconnect(sk, 0, 0, 0);
			break;

		default:
			break;
	}

	return 0;
}

/*
 * State machine for state 3, Connected State.
 * The handling of the timer(s) is in file x25_timer.c
 * Handling of state 0 and connection release is in af_x25.c.
 */
static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
{
	int queued = 0;
	int modulus;
	struct x25_sock *x25 = x25_sk(sk);

	modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;

	switch (frametype) {

		case X25_RESET_REQUEST:
			x25_write_internal(sk, X25_RESET_CONFIRMATION);
			x25_stop_timer(sk);
			x25->condition = 0x00;
			x25->vs        = 0;
			x25->vr        = 0;
			x25->va        = 0;
			x25->vl        = 0;
			x25_requeue_frames(sk);
			break;

		case X25_CLEAR_REQUEST:
			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
			break;

		case X25_RR:
		case X25_RNR:
			if (!x25_validate_nr(sk, nr)) {
				x25_clear_queues(sk);
				x25_write_internal(sk, X25_RESET_REQUEST);
				x25_start_t22timer(sk);
				x25->condition = 0x00;
				x25->vs        = 0;
				x25->vr        = 0;
				x25->va        = 0;
				x25->vl        = 0;
				x25->state     = X25_STATE_4;
			} else {
				x25_frames_acked(sk, nr);
				if (frametype == X25_RNR) {
					x25->condition |= X25_COND_PEER_RX_BUSY;
				} else {
					x25->condition &= ~X25_COND_PEER_RX_BUSY;
				}
			}
			break;

		case X25_DATA:	/* XXX */
			x25->condition &= ~X25_COND_PEER_RX_BUSY;
			if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) {
				x25_clear_queues(sk);
				x25_write_internal(sk, X25_RESET_REQUEST);
				x25_start_t22timer(sk);
				x25->condition = 0x00;
				x25->vs        = 0;
				x25->vr        = 0;
				x25->va        = 0;
				x25->vl        = 0;
				x25->state     = X25_STATE_4;
				break;
			}
			x25_frames_acked(sk, nr);
			if (ns == x25->vr) {
				if (x25_queue_rx_frame(sk, skb, m) == 0) {
					x25->vr = (x25->vr + 1) % modulus;
					queued = 1;
				} else {
					/* Should never happen */
					x25_clear_queues(sk);
					x25_write_internal(sk, X25_RESET_REQUEST);
					x25_start_t22timer(sk);
					x25->condition = 0x00;
					x25->vs        = 0;
					x25->vr        = 0;
					x25->va        = 0;
					x25->vl        = 0;
					x25->state     = X25_STATE_4;
					break;
				}
				if (atomic_read(&sk->sk_rmem_alloc) >
				    (sk->sk_rcvbuf >> 1))
					x25->condition |= X25_COND_OWN_RX_BUSY;
			}
			/*
			 *	If the window is full Ack it immediately, else
			 *	start the holdback timer.
			 */
			if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
				x25->condition &= ~X25_COND_ACK_PENDING;
				x25_stop_timer(sk);
				x25_enquiry_response(sk);
			} else {
				x25->condition |= X25_COND_ACK_PENDING;
				x25_start_t2timer(sk);
			}
			break;

		case X25_INTERRUPT_CONFIRMATION:
			clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
			break;

		case X25_INTERRUPT:
			if (sock_flag(sk, SOCK_URGINLINE))
				queued = !sock_queue_rcv_skb(sk, skb);
			else {
				skb_set_owner_r(skb, sk);
				skb_queue_tail(&x25->interrupt_in_queue, skb);
				queued = 1;
			}
			sk_send_sigurg(sk);
			x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
			break;

		default:
			printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
			break;
	}

	return queued;
}

/*
 * State machine for state 4, Awaiting Reset Confirmation State.
 * The handling of the timer(s) is in file x25_timer.c
 * Handling of state 0 and connection release is in af_x25.c.
 */
static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	switch (frametype) {

		case X25_RESET_REQUEST:
			x25_write_internal(sk, X25_RESET_CONFIRMATION);
		case X25_RESET_CONFIRMATION: {
			struct x25_sock *x25 = x25_sk(sk);

			x25_stop_timer(sk);
			x25->condition = 0x00;
			x25->va        = 0;
			x25->vr        = 0;
			x25->vs        = 0;
			x25->vl        = 0;
			x25->state     = X25_STATE_3;
			x25_requeue_frames(sk);
			break;
		}
		case X25_CLEAR_REQUEST:
			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
			break;

		default:
			break;
	}

	return 0;
}

/* Higher level upcall for a LAPB frame */
int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb)
{
	struct x25_sock *x25 = x25_sk(sk);
	int queued = 0, frametype, ns, nr, q, d, m;

	if (x25->state == X25_STATE_0)
		return 0;

	frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);

	switch (x25->state) {
		case X25_STATE_1:
			queued = x25_state1_machine(sk, skb, frametype);
			break;
		case X25_STATE_2:
			queued = x25_state2_machine(sk, skb, frametype);
			break;
		case X25_STATE_3:
			queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
			break;
		case X25_STATE_4:
			queued = x25_state4_machine(sk, skb, frametype);
			break;
	}

	x25_kick(sk);

	return queued;
}

int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
	int queued = x25_process_rx_frame(sk, skb);

	if (!queued)
		kfree_skb(skb);

	return 0;
}
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 Centralised disconnection code.
	19	* New timer architecture.
f8e1d201	20	* 2000-03-20 Daniela Squassoni Disabling/enabling of facilities
1da177e4 LT	21	* negotiation.
	22	* 2000-11-10 Henner Eisen Check and reset for out-of-sequence
	23	* i-frames.
	24	*/
	25
5a0e3ad6	26	#include <linux/slab.h>
1da177e4 LT	27	#include <linux/errno.h>
	28	#include <linux/kernel.h>
	29	#include <linux/string.h>
	30	#include <linux/skbuff.h>
	31	#include <net/sock.h>
c752f073	32	#include <net/tcp_states.h>
1da177e4 LT	33	#include <net/x25.h>
	34
	35	static int x25_queue_rx_frame(struct sock sk, struct sk_buff skb, int more)
	36	{
	37	struct sk_buff skbo, skbn = skb;
	38	struct x25_sock *x25 = x25_sk(sk);
	39
	40	if (more) {
	41	x25->fraglen += skb->len;
	42	skb_queue_tail(&x25->fragment_queue, skb);
	43	skb_set_owner_r(skb, sk);
	44	return 0;
	45	}
	46
	47	if (!more && x25->fraglen > 0) { /* End of fragment */
	48	int len = x25->fraglen + skb->len;
	49
	50	if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){
	51	kfree_skb(skb);
	52	return 1;
	53	}
	54
	55	skb_queue_tail(&x25->fragment_queue, skb);
	56
badff6d0	57	skb_reset_transport_header(skbn);
1da177e4 LT	58
1da177e4 LT	59	skbo = skb_dequeue(&x25->fragment_queue);
1a4e2d09 ACM	60	skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len),
1a4e2d09 ACM	61	skbo->len);
1da177e4 LT	62	kfree_skb(skbo);
	63
	64	while ((skbo =
	65	skb_dequeue(&x25->fragment_queue)) != NULL) {
	66	skb_pull(skbo, (x25->neighbour->extended) ?
	67	X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
1a4e2d09 ACM	68	skb_copy_from_linear_data(skbo,
	69	skb_put(skbn, skbo->len),
	70	skbo->len);
1da177e4 LT	71	kfree_skb(skbo);
	72	}
	73
f8e1d201	74	x25->fraglen = 0;
1da177e4 LT	75	}
	76
	77	skb_set_owner_r(skbn, sk);
	78	skb_queue_tail(&sk->sk_receive_queue, skbn);
	79	if (!sock_flag(sk, SOCK_DEAD))
	80	sk->sk_data_ready(sk, skbn->len);
	81
	82	return 0;
	83	}
	84
	85	/*
	86	* State machine for state 1, Awaiting Call Accepted State.
	87	* The handling of the timer(s) is in file x25_timer.c.
	88	* Handling of state 0 and connection release is in af_x25.c.
	89	*/
	90	static int x25_state1_machine(struct sock sk, struct sk_buff skb, int frametype)
	91	{
	92	struct x25_address source_addr, dest_addr;
f5eb917b	93	int len;
1da177e4 LT	94
	95	switch (frametype) {
	96	case X25_CALL_ACCEPTED: {
	97	struct x25_sock *x25 = x25_sk(sk);
	98
	99	x25_stop_timer(sk);
	100	x25->condition = 0x00;
	101	x25->vs = 0;
	102	x25->va = 0;
	103	x25->vr = 0;
	104	x25->vl = 0;
	105	x25->state = X25_STATE_3;
	106	sk->sk_state = TCP_ESTABLISHED;
	107	/*
	108	* Parse the data in the frame.
	109	*/
	110	skb_pull(skb, X25_STD_MIN_LEN);
f5eb917b JH	111
	112	len = x25_parse_address_block(skb, &source_addr,
	113	&dest_addr);
	114	if (len > 0)
	115	skb_pull(skb, len);
	116
	117	len = x25_parse_facilities(skb, &x25->facilities,
a64b7b93	118	&x25->dte_facilities,
f5eb917b JH	119	&x25->vc_facil_mask);
	120	if (len > 0)
	121	skb_pull(skb, len);
a6331d6f	122	else
a6331d6f	123	return -1;
1da177e4 LT	124	/*
	125	* Copy any Call User Data.
	126	*/
091bb8ab	127	if (skb->len > 0) {
d626f62b ACM	128	skb_copy_from_linear_data(skb,
	129	x25->calluserdata.cuddata,
	130	skb->len);
1da177e4 LT	131	x25->calluserdata.cudlength = skb->len;
	132	}
	133	if (!sock_flag(sk, SOCK_DEAD))
	134	sk->sk_state_change(sk);
	135	break;
	136	}
	137	case X25_CLEAR_REQUEST:
	138	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	139	x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
	140	break;
	141
	142	default:
	143	break;
	144	}
	145
	146	return 0;
	147	}
	148
	149	/*
	150	* State machine for state 2, Awaiting Clear Confirmation State.
	151	* The handling of the timer(s) is in file x25_timer.c
	152	* Handling of state 0 and connection release is in af_x25.c.
	153	*/
	154	static int x25_state2_machine(struct sock sk, struct sk_buff skb, int frametype)
	155	{
	156	switch (frametype) {
	157
	158	case X25_CLEAR_REQUEST:
	159	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	160	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	161	break;
	162
	163	case X25_CLEAR_CONFIRMATION:
	164	x25_disconnect(sk, 0, 0, 0);
	165	break;
	166
	167	default:
	168	break;
	169	}
	170
	171	return 0;
	172	}
	173
	174	/*
	175	* State machine for state 3, Connected State.
	176	* The handling of the timer(s) is in file x25_timer.c
	177	* Handling of state 0 and connection release is in af_x25.c.
	178	*/
	179	static int x25_state3_machine(struct sock sk, struct sk_buff skb, int frametype, int ns, int nr, int q, int d, int m)
	180	{
	181	int queued = 0;
	182	int modulus;
	183	struct x25_sock *x25 = x25_sk(sk);
f8e1d201	184
1da177e4 LT	185	modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
	186
	187	switch (frametype) {
	188
	189	case X25_RESET_REQUEST:
	190	x25_write_internal(sk, X25_RESET_CONFIRMATION);
	191	x25_stop_timer(sk);
	192	x25->condition = 0x00;
	193	x25->vs = 0;
	194	x25->vr = 0;
	195	x25->va = 0;
	196	x25->vl = 0;
	197	x25_requeue_frames(sk);
	198	break;
	199
	200	case X25_CLEAR_REQUEST:
	201	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	202	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	203	break;
	204
	205	case X25_RR:
	206	case X25_RNR:
	207	if (!x25_validate_nr(sk, nr)) {
	208	x25_clear_queues(sk);
	209	x25_write_internal(sk, X25_RESET_REQUEST);
	210	x25_start_t22timer(sk);
	211	x25->condition = 0x00;
	212	x25->vs = 0;
	213	x25->vr = 0;
	214	x25->va = 0;
	215	x25->vl = 0;
	216	x25->state = X25_STATE_4;
	217	} else {
	218	x25_frames_acked(sk, nr);
	219	if (frametype == X25_RNR) {
	220	x25->condition \|= X25_COND_PEER_RX_BUSY;
	221	} else {
	222	x25->condition &= ~X25_COND_PEER_RX_BUSY;
	223	}
	224	}
	225	break;
	226
	227	case X25_DATA: /* XXX */
	228	x25->condition &= ~X25_COND_PEER_RX_BUSY;
	229	if ((ns != x25->vr) \|\| !x25_validate_nr(sk, nr)) {
	230	x25_clear_queues(sk);
	231	x25_write_internal(sk, X25_RESET_REQUEST);
	232	x25_start_t22timer(sk);
	233	x25->condition = 0x00;
	234	x25->vs = 0;
	235	x25->vr = 0;
	236	x25->va = 0;
	237	x25->vl = 0;
	238	x25->state = X25_STATE_4;
	239	break;
	240	}
	241	x25_frames_acked(sk, nr);
	242	if (ns == x25->vr) {
	243	if (x25_queue_rx_frame(sk, skb, m) == 0) {
	244	x25->vr = (x25->vr + 1) % modulus;
	245	queued = 1;
	246	} else {
	247	/* Should never happen */
	248	x25_clear_queues(sk);
249	x25_write_internal(sk, X25_RESET_REQUEST);
250	x25_start_t22timer(sk);
251	x25->condition = 0x00;
252	x25->vs = 0;
253	x25->vr = 0;
254	x25->va = 0;
255	x25->vl = 0;
256	x25->state = X25_STATE_4;
257	break;
258	}
259	if (atomic_read(&sk->sk_rmem_alloc) >
6bf1574e	260	(sk->sk_rcvbuf >> 1))
1da177e4 LT	261	x25->condition \|= X25_COND_OWN_RX_BUSY;
	262	}
	263	/*
	264	* If the window is full Ack it immediately, else
	265	* start the holdback timer.
	266	*/
	267	if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
	268	x25->condition &= ~X25_COND_ACK_PENDING;
	269	x25_stop_timer(sk);
	270	x25_enquiry_response(sk);
	271	} else {
	272	x25->condition \|= X25_COND_ACK_PENDING;
	273	x25_start_t2timer(sk);
	274	}
	275	break;
	276
	277	case X25_INTERRUPT_CONFIRMATION:
b7792e34	278	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
1da177e4 LT	279	break;
	280
	281	case X25_INTERRUPT:
	282	if (sock_flag(sk, SOCK_URGINLINE))
	283	queued = !sock_queue_rcv_skb(sk, skb);
	284	else {
	285	skb_set_owner_r(skb, sk);
	286	skb_queue_tail(&x25->interrupt_in_queue, skb);
	287	queued = 1;
	288	}
	289	sk_send_sigurg(sk);
	290	x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
	291	break;
	292
	293	default:
	294	printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
	295	break;
	296	}
	297
	298	return queued;
	299	}
	300
	301	/*
	302	* State machine for state 4, Awaiting Reset Confirmation State.
	303	* The handling of the timer(s) is in file x25_timer.c
	304	* Handling of state 0 and connection release is in af_x25.c.
	305	*/
	306	static int x25_state4_machine(struct sock sk, struct sk_buff skb, int frametype)
	307	{
	308	switch (frametype) {
	309
	310	case X25_RESET_REQUEST:
	311	x25_write_internal(sk, X25_RESET_CONFIRMATION);
	312	case X25_RESET_CONFIRMATION: {
	313	struct x25_sock *x25 = x25_sk(sk);
	314
	315	x25_stop_timer(sk);
	316	x25->condition = 0x00;
	317	x25->va = 0;
	318	x25->vr = 0;
	319	x25->vs = 0;
	320	x25->vl = 0;
	321	x25->state = X25_STATE_3;
	322	x25_requeue_frames(sk);
	323	break;
	324	}
	325	case X25_CLEAR_REQUEST:
	326	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	327	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	328	break;
	329
	330	default:
	331	break;
	332	}
	333
	334	return 0;
	335	}
	336
	337	/* Higher level upcall for a LAPB frame */
	338	int x25_process_rx_frame(struct sock sk, struct sk_buff skb)
	339	{
	340	struct x25_sock *x25 = x25_sk(sk);
	341	int queued = 0, frametype, ns, nr, q, d, m;
	342
343	if (x25->state == X25_STATE_0)
344	return 0;
345
346	frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
347
348	switch (x25->state) {
349	case X25_STATE_1:
350	queued = x25_state1_machine(sk, skb, frametype);
351	break;
352	case X25_STATE_2:
353	queued = x25_state2_machine(sk, skb, frametype);
354	break;
355	case X25_STATE_3:
356	queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
357	break;
358	case X25_STATE_4:
359	queued = x25_state4_machine(sk, skb, frametype);
360	break;
361	}
362
363	x25_kick(sk);
364
365	return queued;
366	}
367
368	int x25_backlog_rcv(struct sock sk, struct sk_buff skb)
369	{
370	int queued = x25_process_rx_frame(sk, skb);
371
372	if (!queued)
373	kfree_skb(skb);
374
375	return 0;
376	}