[net-next-2.6.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);
			/*
			 *	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);
1da177e4 LT	122	/*
	123	* Copy any Call User Data.
	124	*/
091bb8ab	125	if (skb->len > 0) {
d626f62b ACM	126	skb_copy_from_linear_data(skb,
	127	x25->calluserdata.cuddata,
	128	skb->len);
1da177e4 LT	129	x25->calluserdata.cudlength = skb->len;
	130	}
	131	if (!sock_flag(sk, SOCK_DEAD))
	132	sk->sk_state_change(sk);
	133	break;
	134	}
	135	case X25_CLEAR_REQUEST:
	136	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	137	x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
	138	break;
	139
	140	default:
	141	break;
	142	}
	143
	144	return 0;
	145	}
	146
	147	/*
	148	* State machine for state 2, Awaiting Clear Confirmation State.
	149	* The handling of the timer(s) is in file x25_timer.c
	150	* Handling of state 0 and connection release is in af_x25.c.
	151	*/
	152	static int x25_state2_machine(struct sock sk, struct sk_buff skb, int frametype)
	153	{
	154	switch (frametype) {
	155
	156	case X25_CLEAR_REQUEST:
	157	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	158	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	159	break;
	160
	161	case X25_CLEAR_CONFIRMATION:
	162	x25_disconnect(sk, 0, 0, 0);
	163	break;
	164
	165	default:
	166	break;
	167	}
	168
	169	return 0;
	170	}
	171
	172	/*
	173	* State machine for state 3, Connected State.
	174	* The handling of the timer(s) is in file x25_timer.c
	175	* Handling of state 0 and connection release is in af_x25.c.
	176	*/
	177	static int x25_state3_machine(struct sock sk, struct sk_buff skb, int frametype, int ns, int nr, int q, int d, int m)
	178	{
	179	int queued = 0;
	180	int modulus;
	181	struct x25_sock *x25 = x25_sk(sk);
f8e1d201	182
1da177e4 LT	183	modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
	184
	185	switch (frametype) {
	186
	187	case X25_RESET_REQUEST:
	188	x25_write_internal(sk, X25_RESET_CONFIRMATION);
	189	x25_stop_timer(sk);
	190	x25->condition = 0x00;
	191	x25->vs = 0;
	192	x25->vr = 0;
	193	x25->va = 0;
	194	x25->vl = 0;
	195	x25_requeue_frames(sk);
	196	break;
	197
	198	case X25_CLEAR_REQUEST:
	199	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	200	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	201	break;
	202
	203	case X25_RR:
	204	case X25_RNR:
	205	if (!x25_validate_nr(sk, nr)) {
	206	x25_clear_queues(sk);
	207	x25_write_internal(sk, X25_RESET_REQUEST);
	208	x25_start_t22timer(sk);
	209	x25->condition = 0x00;
	210	x25->vs = 0;
	211	x25->vr = 0;
	212	x25->va = 0;
	213	x25->vl = 0;
	214	x25->state = X25_STATE_4;
	215	} else {
	216	x25_frames_acked(sk, nr);
	217	if (frametype == X25_RNR) {
	218	x25->condition \|= X25_COND_PEER_RX_BUSY;
	219	} else {
	220	x25->condition &= ~X25_COND_PEER_RX_BUSY;
	221	}
	222	}
	223	break;
	224
	225	case X25_DATA: /* XXX */
	226	x25->condition &= ~X25_COND_PEER_RX_BUSY;
	227	if ((ns != x25->vr) \|\| !x25_validate_nr(sk, nr)) {
	228	x25_clear_queues(sk);
	229	x25_write_internal(sk, X25_RESET_REQUEST);
	230	x25_start_t22timer(sk);
	231	x25->condition = 0x00;
	232	x25->vs = 0;
	233	x25->vr = 0;
	234	x25->va = 0;
	235	x25->vl = 0;
	236	x25->state = X25_STATE_4;
	237	break;
	238	}
	239	x25_frames_acked(sk, nr);
	240	if (ns == x25->vr) {
	241	if (x25_queue_rx_frame(sk, skb, m) == 0) {
	242	x25->vr = (x25->vr + 1) % modulus;
	243	queued = 1;
	244	} else {
	245	/* Should never happen */
	246	x25_clear_queues(sk);
247	x25_write_internal(sk, X25_RESET_REQUEST);
248	x25_start_t22timer(sk);
249	x25->condition = 0x00;
250	x25->vs = 0;
251	x25->vr = 0;
252	x25->va = 0;
253	x25->vl = 0;
254	x25->state = X25_STATE_4;
255	break;
256	}
257	if (atomic_read(&sk->sk_rmem_alloc) >
6bf1574e	258	(sk->sk_rcvbuf >> 1))
1da177e4 LT	259	x25->condition \|= X25_COND_OWN_RX_BUSY;
	260	}
	261	/*
	262	* If the window is full Ack it immediately, else
	263	* start the holdback timer.
	264	*/
	265	if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
	266	x25->condition &= ~X25_COND_ACK_PENDING;
	267	x25_stop_timer(sk);
	268	x25_enquiry_response(sk);
	269	} else {
	270	x25->condition \|= X25_COND_ACK_PENDING;
	271	x25_start_t2timer(sk);
	272	}
	273	break;
	274
	275	case X25_INTERRUPT_CONFIRMATION:
b7792e34	276	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
1da177e4 LT	277	break;
	278
	279	case X25_INTERRUPT:
	280	if (sock_flag(sk, SOCK_URGINLINE))
	281	queued = !sock_queue_rcv_skb(sk, skb);
	282	else {
	283	skb_set_owner_r(skb, sk);
	284	skb_queue_tail(&x25->interrupt_in_queue, skb);
	285	queued = 1;
	286	}
	287	sk_send_sigurg(sk);
	288	x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
	289	break;
	290
	291	default:
	292	printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
	293	break;
	294	}
	295
	296	return queued;
	297	}
	298
	299	/*
	300	* State machine for state 4, Awaiting Reset Confirmation State.
	301	* The handling of the timer(s) is in file x25_timer.c
	302	* Handling of state 0 and connection release is in af_x25.c.
	303	*/
	304	static int x25_state4_machine(struct sock sk, struct sk_buff skb, int frametype)
	305	{
	306	switch (frametype) {
	307
	308	case X25_RESET_REQUEST:
	309	x25_write_internal(sk, X25_RESET_CONFIRMATION);
	310	case X25_RESET_CONFIRMATION: {
	311	struct x25_sock *x25 = x25_sk(sk);
	312
	313	x25_stop_timer(sk);
	314	x25->condition = 0x00;
	315	x25->va = 0;
	316	x25->vr = 0;
	317	x25->vs = 0;
	318	x25->vl = 0;
	319	x25->state = X25_STATE_3;
	320	x25_requeue_frames(sk);
	321	break;
	322	}
	323	case X25_CLEAR_REQUEST:
	324	x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
	325	x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
	326	break;
	327
	328	default:
	329	break;
	330	}
	331
	332	return 0;
	333	}
	334
	335	/* Higher level upcall for a LAPB frame */
	336	int x25_process_rx_frame(struct sock sk, struct sk_buff skb)
	337	{
	338	struct x25_sock *x25 = x25_sk(sk);
	339	int queued = 0, frametype, ns, nr, q, d, m;
	340
341	if (x25->state == X25_STATE_0)
342	return 0;
343
344	frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
345
346	switch (x25->state) {
347	case X25_STATE_1:
348	queued = x25_state1_machine(sk, skb, frametype);
349	break;
350	case X25_STATE_2:
351	queued = x25_state2_machine(sk, skb, frametype);
352	break;
353	case X25_STATE_3:
354	queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
355	break;
356	case X25_STATE_4:
357	queued = x25_state4_machine(sk, skb, frametype);
358	break;
359	}
360
361	x25_kick(sk);
362
363	return queued;
364	}
365
366	int x25_backlog_rcv(struct sock sk, struct sk_buff skb)
367	{
368	int queued = x25_process_rx_frame(sk, skb);
369
370	if (!queued)
371	kfree_skb(skb);
372
373	return 0;
374	}