[linux.git] / net / ax25 / ax25_out.c

/*
 * This program 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.
 *
 * Copyright (C) Alan Cox GW4PTS ([email protected])
 * Copyright (C) Jonathan Naylor G4KLX ([email protected])
 * Copyright (C) Joerg Reuter DL1BKE ([email protected])
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/spinlock.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>

static DEFINE_SPINLOCK(ax25_frag_lock);

ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_address *src, ax25_address *dest, ax25_digi *digi, struct net_device *dev)
{
	ax25_dev *ax25_dev;
	ax25_cb *ax25;

	/*
	 * Take the default packet length for the device if zero is
	 * specified.
	 */
	if (paclen == 0) {
		if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
			return NULL;

		paclen = ax25_dev->values[AX25_VALUES_PACLEN];
	}

	/*
	 * Look for an existing connection.
	 */
	if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
		ax25_output(ax25, paclen, skb);
		return ax25;		/* It already existed */
	}

	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
		return NULL;

	if ((ax25 = ax25_create_cb()) == NULL)
		return NULL;

	ax25_fillin_cb(ax25, ax25_dev);

	ax25->source_addr = *src;
	ax25->dest_addr   = *dest;

	if (digi != NULL) {
		ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
		if (ax25->digipeat == NULL) {
			ax25_cb_put(ax25);
			return NULL;
		}
	}

	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	case AX25_PROTO_STD_SIMPLEX:
	case AX25_PROTO_STD_DUPLEX:
		ax25_std_establish_data_link(ax25);
		break;

#ifdef CONFIG_AX25_DAMA_SLAVE
	case AX25_PROTO_DAMA_SLAVE:
		if (ax25_dev->dama.slave)
			ax25_ds_establish_data_link(ax25);
		else
			ax25_std_establish_data_link(ax25);
		break;
#endif
	}

	/*
	 * There is one ref for the state machine; a caller needs
	 * one more to put it back, just like with the existing one.
	 */
	ax25_cb_hold(ax25);

	ax25_cb_add(ax25);

	ax25->state = AX25_STATE_1;

	ax25_start_heartbeat(ax25);

	ax25_output(ax25, paclen, skb);

	return ax25;			/* We had to create it */
}

EXPORT_SYMBOL(ax25_send_frame);

/*
 *	All outgoing AX.25 I frames pass via this routine. Therefore this is
 *	where the fragmentation of frames takes place. If fragment is set to
 *	zero then we are not allowed to do fragmentation, even if the frame
 *	is too large.
 */
void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb)
{
	struct sk_buff *skbn;
	unsigned char *p;
	int frontlen, len, fragno, ka9qfrag, first = 1;

	if (paclen < 16) {
		WARN_ON_ONCE(1);
		kfree_skb(skb);
		return;
	}

	if ((skb->len - 1) > paclen) {
		if (*skb->data == AX25_P_TEXT) {
			skb_pull(skb, 1); /* skip PID */
			ka9qfrag = 0;
		} else {
			paclen -= 2;	/* Allow for fragment control info */
			ka9qfrag = 1;
		}

		fragno = skb->len / paclen;
		if (skb->len % paclen == 0) fragno--;

		frontlen = skb_headroom(skb);	/* Address space + CTRL */

		while (skb->len > 0) {
			spin_lock_bh(&ax25_frag_lock);
			if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
				spin_unlock_bh(&ax25_frag_lock);
				printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
				return;
			}

			if (skb->sk != NULL)
				skb_set_owner_w(skbn, skb->sk);

			spin_unlock_bh(&ax25_frag_lock);

			len = (paclen > skb->len) ? skb->len : paclen;

			if (ka9qfrag == 1) {
				skb_reserve(skbn, frontlen + 2);
				skb_set_network_header(skbn,
						      skb_network_offset(skb));
				skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
				p = skb_push(skbn, 2);

				*p++ = AX25_P_SEGMENT;

				*p = fragno--;
				if (first) {
					*p |= AX25_SEG_FIRST;
					first = 0;
				}
			} else {
				skb_reserve(skbn, frontlen + 1);
				skb_set_network_header(skbn,
						      skb_network_offset(skb));
				skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
				p = skb_push(skbn, 1);
				*p = AX25_P_TEXT;
			}

			skb_pull(skb, len);
			skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
		}

		kfree_skb(skb);
	} else {
		skb_queue_tail(&ax25->write_queue, skb);	  /* Throw it on the queue */
	}

	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	case AX25_PROTO_STD_SIMPLEX:
	case AX25_PROTO_STD_DUPLEX:
		ax25_kick(ax25);
		break;

#ifdef CONFIG_AX25_DAMA_SLAVE
	/*
	 * A DAMA slave is _required_ to work as normal AX.25L2V2
	 * if no DAMA master is available.
	 */
	case AX25_PROTO_DAMA_SLAVE:
		if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
		break;
#endif
	}
}

/*
 *  This procedure is passed a buffer descriptor for an iframe. It builds
 *  the rest of the control part of the frame and then writes it out.
 */
static void ax25_send_iframe(ax25_cb *ax25, struct sk_buff *skb, int poll_bit)
{
	unsigned char *frame;

	if (skb == NULL)
		return;

	skb_reset_network_header(skb);

	if (ax25->modulus == AX25_MODULUS) {
		frame = skb_push(skb, 1);

		*frame = AX25_I;
		*frame |= (poll_bit) ? AX25_PF : 0;
		*frame |= (ax25->vr << 5);
		*frame |= (ax25->vs << 1);
	} else {
		frame = skb_push(skb, 2);

		frame[0] = AX25_I;
		frame[0] |= (ax25->vs << 1);
		frame[1] = (poll_bit) ? AX25_EPF : 0;
		frame[1] |= (ax25->vr << 1);
	}

	ax25_start_idletimer(ax25);

	ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
}

void ax25_kick(ax25_cb *ax25)
{
	struct sk_buff *skb, *skbn;
	int last = 1;
	unsigned short start, end, next;

	if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
		return;

	if (ax25->condition & AX25_COND_PEER_RX_BUSY)
		return;

	if (skb_peek(&ax25->write_queue) == NULL)
		return;

	start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
	end   = (ax25->va + ax25->window) % ax25->modulus;

	if (start == end)
		return;

	/*
	 * Transmit data until either we're out of data to send or
	 * the window is full. Send a poll on the final I frame if
	 * the window is filled.
	 */

	/*
	 * Dequeue the frame and copy it.
	 * Check for race with ax25_clear_queues().
	 */
	skb  = skb_dequeue(&ax25->write_queue);
	if (!skb)
		return;

	ax25->vs = start;

	do {
		if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
			skb_queue_head(&ax25->write_queue, skb);
			break;
		}

		if (skb->sk != NULL)
			skb_set_owner_w(skbn, skb->sk);

		next = (ax25->vs + 1) % ax25->modulus;
		last = (next == end);

		/*
		 * Transmit the frame copy.
		 * bke 960114: do not set the Poll bit on the last frame
		 * in DAMA mode.
		 */
		switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
		case AX25_PROTO_STD_SIMPLEX:
		case AX25_PROTO_STD_DUPLEX:
			ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
			break;

#ifdef CONFIG_AX25_DAMA_SLAVE
		case AX25_PROTO_DAMA_SLAVE:
			ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
			break;
#endif
		}

		ax25->vs = next;

		/*
		 * Requeue the original data frame.
		 */
		skb_queue_tail(&ax25->ack_queue, skb);

	} while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);

	ax25->condition &= ~AX25_COND_ACK_PENDING;

	if (!ax25_t1timer_running(ax25)) {
		ax25_stop_t3timer(ax25);
		ax25_calculate_t1(ax25);
		ax25_start_t1timer(ax25);
	}
}

void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type)
{
	struct sk_buff *skbn;
	unsigned char *ptr;
	int headroom;

	if (ax25->ax25_dev == NULL) {
		ax25_disconnect(ax25, ENETUNREACH);
		return;
	}

	headroom = ax25_addr_size(ax25->digipeat);

	if (skb_headroom(skb) < headroom) {
		if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
			printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
			kfree_skb(skb);
			return;
		}

		if (skb->sk != NULL)
			skb_set_owner_w(skbn, skb->sk);

		kfree_skb(skb);
		skb = skbn;
	}

	ptr = skb_push(skb, headroom);

	ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);

	ax25_queue_xmit(skb, ax25->ax25_dev->dev);
}

/*
 *	A small shim to dev_queue_xmit to add the KISS control byte, and do
 *	any packet forwarding in operation.
 */
void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned char *ptr;

	skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(dev));

	ptr  = skb_push(skb, 1);
	*ptr = 0x00;			/* KISS */

	dev_queue_xmit(skb);
}

int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
{
	if (ax25->vs == nr) {
		ax25_frames_acked(ax25, nr);
		ax25_calculate_rtt(ax25);
		ax25_stop_t1timer(ax25);
		ax25_start_t3timer(ax25);
		return 1;
	} else {
		if (ax25->va != nr) {
			ax25_frames_acked(ax25, nr);
			ax25_calculate_t1(ax25);
			ax25_start_t1timer(ax25);
			return 1;
		}
	}
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Alan Cox GW4PTS ([email protected])
	8	* Copyright (C) Jonathan Naylor G4KLX ([email protected])
	9	* Copyright (C) Joerg Reuter DL1BKE ([email protected])
	10	*/
1da177e4 LT	11	#include <linux/errno.h>
	12	#include <linux/types.h>
	13	#include <linux/socket.h>
	14	#include <linux/in.h>
	15	#include <linux/kernel.h>
70868eac	16	#include <linux/module.h>
1da177e4 LT	17	#include <linux/timer.h>
	18	#include <linux/string.h>
	19	#include <linux/sockios.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/net.h>
5a0e3ad6	22	#include <linux/slab.h>
1da177e4 LT	23	#include <net/ax25.h>
	24	#include <linux/inet.h>
	25	#include <linux/netdevice.h>
	26	#include <linux/skbuff.h>
	27	#include <linux/netfilter.h>
	28	#include <net/sock.h>
	29	#include <asm/uaccess.h>
	30	#include <asm/system.h>
	31	#include <linux/fcntl.h>
	32	#include <linux/mm.h>
	33	#include <linux/interrupt.h>
	34
	35	static DEFINE_SPINLOCK(ax25_frag_lock);
	36
	37	ax25_cb ax25_send_frame(struct sk_buff skb, int paclen, ax25_address src, ax25_address dest, ax25_digi digi, struct net_device dev)
	38	{
	39	ax25_dev *ax25_dev;
	40	ax25_cb *ax25;
	41
	42	/*
	43	* Take the default packet length for the device if zero is
	44	* specified.
	45	*/
	46	if (paclen == 0) {
	47	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	48	return NULL;
	49
	50	paclen = ax25_dev->values[AX25_VALUES_PACLEN];
	51	}
	52
	53	/*
	54	* Look for an existing connection.
	55	*/
	56	if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
	57	ax25_output(ax25, paclen, skb);
	58	return ax25; /* It already existed */
	59	}
	60
	61	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	62	return NULL;
	63
	64	if ((ax25 = ax25_create_cb()) == NULL)
	65	return NULL;
	66
	67	ax25_fillin_cb(ax25, ax25_dev);
	68
	69	ax25->source_addr = *src;
	70	ax25->dest_addr = *dest;
	71
	72	if (digi != NULL) {
0459d70a ACM	73	ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
0459d70a ACM	74	if (ax25->digipeat == NULL) {
1da177e4 LT	75	ax25_cb_put(ax25);
	76	return NULL;
	77	}
1da177e4 LT	78	}
	79
	80	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	81	case AX25_PROTO_STD_SIMPLEX:
	82	case AX25_PROTO_STD_DUPLEX:
	83	ax25_std_establish_data_link(ax25);
	84	break;
	85
	86	#ifdef CONFIG_AX25_DAMA_SLAVE
	87	case AX25_PROTO_DAMA_SLAVE:
	88	if (ax25_dev->dama.slave)
	89	ax25_ds_establish_data_link(ax25);
	90	else
	91	ax25_std_establish_data_link(ax25);
	92	break;
	93	#endif
	94	}
	95
d00c362f JP	96	/*
	97	* There is one ref for the state machine; a caller needs
	98	* one more to put it back, just like with the existing one.
	99	*/
	100	ax25_cb_hold(ax25);
	101
1da177e4 LT	102	ax25_cb_add(ax25);
	103
	104	ax25->state = AX25_STATE_1;
	105
	106	ax25_start_heartbeat(ax25);
	107
	108	ax25_output(ax25, paclen, skb);
	109
	110	return ax25; /* We had to create it */
	111	}
	112
70868eac RB	113	EXPORT_SYMBOL(ax25_send_frame);
70868eac RB	114
1da177e4 LT	115	/*
	116	* All outgoing AX.25 I frames pass via this routine. Therefore this is
	117	* where the fragmentation of frames takes place. If fragment is set to
	118	* zero then we are not allowed to do fragmentation, even if the frame
	119	* is too large.
	120	*/
	121	void ax25_output(ax25_cb ax25, int paclen, struct sk_buff skb)
	122	{
	123	struct sk_buff *skbn;
	124	unsigned char *p;
	125	int frontlen, len, fragno, ka9qfrag, first = 1;
	126
f47b7257 JP	127	if (paclen < 16) {
	128	WARN_ON_ONCE(1);
	129	kfree_skb(skb);
	130	return;
	131	}
	132
1da177e4 LT	133	if ((skb->len - 1) > paclen) {
	134	if (*skb->data == AX25_P_TEXT) {
	135	skb_pull(skb, 1); /* skip PID */
	136	ka9qfrag = 0;
	137	} else {
	138	paclen -= 2; /* Allow for fragment control info */
	139	ka9qfrag = 1;
	140	}
	141
	142	fragno = skb->len / paclen;
	143	if (skb->len % paclen == 0) fragno--;
	144
	145	frontlen = skb_headroom(skb); /* Address space + CTRL */
	146
	147	while (skb->len > 0) {
	148	spin_lock_bh(&ax25_frag_lock);
	149	if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
	150	spin_unlock_bh(&ax25_frag_lock);
	151	printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
	152	return;
	153	}
	154
	155	if (skb->sk != NULL)
	156	skb_set_owner_w(skbn, skb->sk);
	157
	158	spin_unlock_bh(&ax25_frag_lock);
	159
	160	len = (paclen > skb->len) ? skb->len : paclen;
	161
	162	if (ka9qfrag == 1) {
	163	skb_reserve(skbn, frontlen + 2);
c14d2450 ACM	164	skb_set_network_header(skbn,
c14d2450 ACM	165	skb_network_offset(skb));
d626f62b	166	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	167	p = skb_push(skbn, 2);
	168
	169	*p++ = AX25_P_SEGMENT;
	170
	171	*p = fragno--;
	172	if (first) {
	173	*p \|= AX25_SEG_FIRST;
	174	first = 0;
	175	}
	176	} else {
	177	skb_reserve(skbn, frontlen + 1);
c14d2450 ACM	178	skb_set_network_header(skbn,
c14d2450 ACM	179	skb_network_offset(skb));
d626f62b	180	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	181	p = skb_push(skbn, 1);
	182	*p = AX25_P_TEXT;
	183	}
	184
	185	skb_pull(skb, len);
	186	skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
	187	}
	188
	189	kfree_skb(skb);
	190	} else {
	191	skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
	192	}
	193
	194	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	195	case AX25_PROTO_STD_SIMPLEX:
	196	case AX25_PROTO_STD_DUPLEX:
	197	ax25_kick(ax25);
	198	break;
	199
	200	#ifdef CONFIG_AX25_DAMA_SLAVE
	201	/*
	202	* A DAMA slave is _required_ to work as normal AX.25L2V2
	203	* if no DAMA master is available.
	204	*/
	205	case AX25_PROTO_DAMA_SLAVE:
	206	if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
	207	break;
	208	#endif
	209	}
	210	}
	211
	212	/*
	213	* This procedure is passed a buffer descriptor for an iframe. It builds
	214	* the rest of the control part of the frame and then writes it out.
	215	*/
	216	static void ax25_send_iframe(ax25_cb ax25, struct sk_buff skb, int poll_bit)
	217	{
	218	unsigned char *frame;
	219
	220	if (skb == NULL)
	221	return;
	222
c1d2bbe1	223	skb_reset_network_header(skb);
1da177e4 LT	224
	225	if (ax25->modulus == AX25_MODULUS) {
	226	frame = skb_push(skb, 1);
	227
	228	*frame = AX25_I;
	229	*frame \|= (poll_bit) ? AX25_PF : 0;
	230	*frame \|= (ax25->vr << 5);
	231	*frame \|= (ax25->vs << 1);
	232	} else {
	233	frame = skb_push(skb, 2);
	234
	235	frame[0] = AX25_I;
	236	frame[0] \|= (ax25->vs << 1);
	237	frame[1] = (poll_bit) ? AX25_EPF : 0;
	238	frame[1] \|= (ax25->vr << 1);
	239	}
	240
	241	ax25_start_idletimer(ax25);
	242
	243	ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
	244	}
	245
	246	void ax25_kick(ax25_cb *ax25)
	247	{
	248	struct sk_buff skb, skbn;
	249	int last = 1;
	250	unsigned short start, end, next;
	251
	252	if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
	253	return;
	254
	255	if (ax25->condition & AX25_COND_PEER_RX_BUSY)
	256	return;
	257
	258	if (skb_peek(&ax25->write_queue) == NULL)
	259	return;
	260
	261	start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
	262	end = (ax25->va + ax25->window) % ax25->modulus;
	263
	264	if (start == end)
	265	return;
	266
1da177e4 LT	267	/*
	268	* Transmit data until either we're out of data to send or
	269	* the window is full. Send a poll on the final I frame if
	270	* the window is filled.
	271	*/
	272
	273	/*
	274	* Dequeue the frame and copy it.
f47b7257	275	* Check for race with ax25_clear_queues().
1da177e4 LT	276	*/
1da177e4 LT	277	skb = skb_dequeue(&ax25->write_queue);
f47b7257 JP	278	if (!skb)
	279	return;
	280
	281	ax25->vs = start;
1da177e4 LT	282
	283	do {
	284	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
	285	skb_queue_head(&ax25->write_queue, skb);
	286	break;
	287	}
	288
	289	if (skb->sk != NULL)
	290	skb_set_owner_w(skbn, skb->sk);
	291
	292	next = (ax25->vs + 1) % ax25->modulus;
	293	last = (next == end);
	294
	295	/*
	296	* Transmit the frame copy.
	297	* bke 960114: do not set the Poll bit on the last frame
	298	* in DAMA mode.
	299	*/
	300	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	301	case AX25_PROTO_STD_SIMPLEX:
	302	case AX25_PROTO_STD_DUPLEX:
	303	ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
	304	break;
	305
	306	#ifdef CONFIG_AX25_DAMA_SLAVE
	307	case AX25_PROTO_DAMA_SLAVE:
	308	ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
	309	break;
	310	#endif
	311	}
	312
	313	ax25->vs = next;
	314
	315	/*
	316	* Requeue the original data frame.
	317	*/
	318	skb_queue_tail(&ax25->ack_queue, skb);
	319
	320	} while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);
	321
	322	ax25->condition &= ~AX25_COND_ACK_PENDING;
	323
	324	if (!ax25_t1timer_running(ax25)) {
	325	ax25_stop_t3timer(ax25);
	326	ax25_calculate_t1(ax25);
	327	ax25_start_t1timer(ax25);
	328	}
	329	}
	330
	331	void ax25_transmit_buffer(ax25_cb ax25, struct sk_buff skb, int type)
	332	{
	333	struct sk_buff *skbn;
	334	unsigned char *ptr;
	335	int headroom;
	336
	337	if (ax25->ax25_dev == NULL) {
	338	ax25_disconnect(ax25, ENETUNREACH);
	339	return;
	340	}
	341
	342	headroom = ax25_addr_size(ax25->digipeat);
	343
	344	if (skb_headroom(skb) < headroom) {
	345	if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
346	printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
347	kfree_skb(skb);
348	return;
349	}
350
351	if (skb->sk != NULL)
352	skb_set_owner_w(skbn, skb->sk);
353
354	kfree_skb(skb);
355	skb = skbn;
356	}
357
358	ptr = skb_push(skb, headroom);
359
360	ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
361
29c4be51	362	ax25_queue_xmit(skb, ax25->ax25_dev->dev);
1da177e4 LT	363	}
	364
	365	/*
	366	* A small shim to dev_queue_xmit to add the KISS control byte, and do
	367	* any packet forwarding in operation.
	368	*/
29c4be51	369	void ax25_queue_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	370	{
	371	unsigned char *ptr;
	372
56cb5156	373	skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(dev));
1da177e4 LT	374
	375	ptr = skb_push(skb, 1);
	376	ptr = 0x00; / KISS */
	377
	378	dev_queue_xmit(skb);
	379	}
	380
	381	int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
	382	{
	383	if (ax25->vs == nr) {
	384	ax25_frames_acked(ax25, nr);
	385	ax25_calculate_rtt(ax25);
	386	ax25_stop_t1timer(ax25);
	387	ax25_start_t3timer(ax25);
	388	return 1;
	389	} else {
	390	if (ax25->va != nr) {
	391	ax25_frames_acked(ax25, nr);
	392	ax25_calculate_t1(ax25);
	393	ax25_start_t1timer(ax25);
	394	return 1;
	395	}
	396	}
	397	return 0;
	398	}
	399