[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 <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);

		consume_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>
1da177e4 LT	30	#include <linux/fcntl.h>
	31	#include <linux/mm.h>
	32	#include <linux/interrupt.h>
	33
	34	static DEFINE_SPINLOCK(ax25_frag_lock);
	35
	36	ax25_cb ax25_send_frame(struct sk_buff skb, int paclen, ax25_address src, ax25_address dest, ax25_digi digi, struct net_device dev)
	37	{
	38	ax25_dev *ax25_dev;
	39	ax25_cb *ax25;
	40
	41	/*
	42	* Take the default packet length for the device if zero is
	43	* specified.
	44	*/
	45	if (paclen == 0) {
	46	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	47	return NULL;
	48
	49	paclen = ax25_dev->values[AX25_VALUES_PACLEN];
	50	}
	51
	52	/*
	53	* Look for an existing connection.
	54	*/
	55	if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
	56	ax25_output(ax25, paclen, skb);
	57	return ax25; /* It already existed */
	58	}
	59
	60	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	61	return NULL;
	62
	63	if ((ax25 = ax25_create_cb()) == NULL)
	64	return NULL;
	65
	66	ax25_fillin_cb(ax25, ax25_dev);
	67
	68	ax25->source_addr = *src;
	69	ax25->dest_addr = *dest;
	70
	71	if (digi != NULL) {
0459d70a ACM	72	ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
0459d70a ACM	73	if (ax25->digipeat == NULL) {
1da177e4 LT	74	ax25_cb_put(ax25);
	75	return NULL;
	76	}
1da177e4 LT	77	}
	78
	79	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	80	case AX25_PROTO_STD_SIMPLEX:
	81	case AX25_PROTO_STD_DUPLEX:
	82	ax25_std_establish_data_link(ax25);
	83	break;
	84
	85	#ifdef CONFIG_AX25_DAMA_SLAVE
	86	case AX25_PROTO_DAMA_SLAVE:
	87	if (ax25_dev->dama.slave)
	88	ax25_ds_establish_data_link(ax25);
	89	else
	90	ax25_std_establish_data_link(ax25);
	91	break;
	92	#endif
	93	}
	94
d00c362f JP	95	/*
	96	* There is one ref for the state machine; a caller needs
	97	* one more to put it back, just like with the existing one.
	98	*/
	99	ax25_cb_hold(ax25);
	100
1da177e4 LT	101	ax25_cb_add(ax25);
	102
	103	ax25->state = AX25_STATE_1;
	104
	105	ax25_start_heartbeat(ax25);
	106
	107	ax25_output(ax25, paclen, skb);
	108
	109	return ax25; /* We had to create it */
	110	}
	111
70868eac RB	112	EXPORT_SYMBOL(ax25_send_frame);
70868eac RB	113
1da177e4 LT	114	/*
	115	* All outgoing AX.25 I frames pass via this routine. Therefore this is
	116	* where the fragmentation of frames takes place. If fragment is set to
	117	* zero then we are not allowed to do fragmentation, even if the frame
	118	* is too large.
	119	*/
	120	void ax25_output(ax25_cb ax25, int paclen, struct sk_buff skb)
	121	{
	122	struct sk_buff *skbn;
	123	unsigned char *p;
	124	int frontlen, len, fragno, ka9qfrag, first = 1;
	125
f47b7257 JP	126	if (paclen < 16) {
	127	WARN_ON_ONCE(1);
	128	kfree_skb(skb);
	129	return;
	130	}
	131
1da177e4 LT	132	if ((skb->len - 1) > paclen) {
	133	if (*skb->data == AX25_P_TEXT) {
	134	skb_pull(skb, 1); /* skip PID */
	135	ka9qfrag = 0;
	136	} else {
	137	paclen -= 2; /* Allow for fragment control info */
	138	ka9qfrag = 1;
	139	}
	140
	141	fragno = skb->len / paclen;
	142	if (skb->len % paclen == 0) fragno--;
	143
	144	frontlen = skb_headroom(skb); /* Address space + CTRL */
	145
	146	while (skb->len > 0) {
	147	spin_lock_bh(&ax25_frag_lock);
	148	if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
	149	spin_unlock_bh(&ax25_frag_lock);
	150	printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
	151	return;
	152	}
	153
	154	if (skb->sk != NULL)
	155	skb_set_owner_w(skbn, skb->sk);
	156
	157	spin_unlock_bh(&ax25_frag_lock);
	158
	159	len = (paclen > skb->len) ? skb->len : paclen;
	160
	161	if (ka9qfrag == 1) {
	162	skb_reserve(skbn, frontlen + 2);
c14d2450 ACM	163	skb_set_network_header(skbn,
c14d2450 ACM	164	skb_network_offset(skb));
d626f62b	165	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	166	p = skb_push(skbn, 2);
	167
	168	*p++ = AX25_P_SEGMENT;
	169
	170	*p = fragno--;
	171	if (first) {
	172	*p \|= AX25_SEG_FIRST;
	173	first = 0;
	174	}
	175	} else {
	176	skb_reserve(skbn, frontlen + 1);
c14d2450 ACM	177	skb_set_network_header(skbn,
c14d2450 ACM	178	skb_network_offset(skb));
d626f62b	179	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	180	p = skb_push(skbn, 1);
	181	*p = AX25_P_TEXT;
	182	}
	183
	184	skb_pull(skb, len);
	185	skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
	186	}
	187
	188	kfree_skb(skb);
	189	} else {
	190	skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
	191	}
	192
	193	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	194	case AX25_PROTO_STD_SIMPLEX:
	195	case AX25_PROTO_STD_DUPLEX:
	196	ax25_kick(ax25);
	197	break;
	198
	199	#ifdef CONFIG_AX25_DAMA_SLAVE
	200	/*
	201	* A DAMA slave is _required_ to work as normal AX.25L2V2
	202	* if no DAMA master is available.
	203	*/
	204	case AX25_PROTO_DAMA_SLAVE:
	205	if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
	206	break;
	207	#endif
	208	}
	209	}
	210
	211	/*
	212	* This procedure is passed a buffer descriptor for an iframe. It builds
	213	* the rest of the control part of the frame and then writes it out.
	214	*/
	215	static void ax25_send_iframe(ax25_cb ax25, struct sk_buff skb, int poll_bit)
	216	{
	217	unsigned char *frame;
	218
	219	if (skb == NULL)
	220	return;
	221
c1d2bbe1	222	skb_reset_network_header(skb);
1da177e4 LT	223
	224	if (ax25->modulus == AX25_MODULUS) {
	225	frame = skb_push(skb, 1);
	226
	227	*frame = AX25_I;
	228	*frame \|= (poll_bit) ? AX25_PF : 0;
	229	*frame \|= (ax25->vr << 5);
	230	*frame \|= (ax25->vs << 1);
	231	} else {
	232	frame = skb_push(skb, 2);
	233
	234	frame[0] = AX25_I;
	235	frame[0] \|= (ax25->vs << 1);
	236	frame[1] = (poll_bit) ? AX25_EPF : 0;
	237	frame[1] \|= (ax25->vr << 1);
	238	}
	239
	240	ax25_start_idletimer(ax25);
	241
	242	ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
	243	}
	244
	245	void ax25_kick(ax25_cb *ax25)
	246	{
	247	struct sk_buff skb, skbn;
	248	int last = 1;
	249	unsigned short start, end, next;
	250
	251	if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
	252	return;
	253
	254	if (ax25->condition & AX25_COND_PEER_RX_BUSY)
	255	return;
	256
	257	if (skb_peek(&ax25->write_queue) == NULL)
	258	return;
	259
	260	start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
	261	end = (ax25->va + ax25->window) % ax25->modulus;
	262
	263	if (start == end)
	264	return;
	265
1da177e4 LT	266	/*
	267	* Transmit data until either we're out of data to send or
	268	* the window is full. Send a poll on the final I frame if
	269	* the window is filled.
	270	*/
	271
	272	/*
	273	* Dequeue the frame and copy it.
f47b7257	274	* Check for race with ax25_clear_queues().
1da177e4 LT	275	*/
1da177e4 LT	276	skb = skb_dequeue(&ax25->write_queue);
f47b7257 JP	277	if (!skb)
	278	return;
	279
	280	ax25->vs = start;
1da177e4 LT	281
	282	do {
	283	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
	284	skb_queue_head(&ax25->write_queue, skb);
	285	break;
	286	}
	287
	288	if (skb->sk != NULL)
	289	skb_set_owner_w(skbn, skb->sk);
	290
	291	next = (ax25->vs + 1) % ax25->modulus;
	292	last = (next == end);
	293
	294	/*
	295	* Transmit the frame copy.
	296	* bke 960114: do not set the Poll bit on the last frame
	297	* in DAMA mode.
	298	*/
	299	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	300	case AX25_PROTO_STD_SIMPLEX:
	301	case AX25_PROTO_STD_DUPLEX:
	302	ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
	303	break;
	304
	305	#ifdef CONFIG_AX25_DAMA_SLAVE
	306	case AX25_PROTO_DAMA_SLAVE:
	307	ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
	308	break;
	309	#endif
	310	}
	311
	312	ax25->vs = next;
	313
	314	/*
	315	* Requeue the original data frame.
	316	*/
	317	skb_queue_tail(&ax25->ack_queue, skb);
	318
	319	} while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);
	320
	321	ax25->condition &= ~AX25_COND_ACK_PENDING;
	322
	323	if (!ax25_t1timer_running(ax25)) {
	324	ax25_stop_t3timer(ax25);
	325	ax25_calculate_t1(ax25);
	326	ax25_start_t1timer(ax25);
	327	}
	328	}
	329
	330	void ax25_transmit_buffer(ax25_cb ax25, struct sk_buff skb, int type)
	331	{
	332	struct sk_buff *skbn;
	333	unsigned char *ptr;
	334	int headroom;
	335
	336	if (ax25->ax25_dev == NULL) {
	337	ax25_disconnect(ax25, ENETUNREACH);
	338	return;
	339	}
	340
	341	headroom = ax25_addr_size(ax25->digipeat);
	342
	343	if (skb_headroom(skb) < headroom) {
	344	if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
345	printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
346	kfree_skb(skb);
347	return;
348	}
349
350	if (skb->sk != NULL)
351	skb_set_owner_w(skbn, skb->sk);
352
5d0ba55b	353	consume_skb(skb);
1da177e4 LT	354	skb = skbn;
	355	}
	356
	357	ptr = skb_push(skb, headroom);
	358
	359	ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
	360
29c4be51	361	ax25_queue_xmit(skb, ax25->ax25_dev->dev);
1da177e4 LT	362	}
	363
	364	/*
	365	* A small shim to dev_queue_xmit to add the KISS control byte, and do
	366	* any packet forwarding in operation.
	367	*/
29c4be51	368	void ax25_queue_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	369	{
	370	unsigned char *ptr;
	371
56cb5156	372	skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(dev));
1da177e4 LT	373
	374	ptr = skb_push(skb, 1);
	375	ptr = 0x00; / KISS */
	376
	377	dev_queue_xmit(skb);
	378	}
	379
	380	int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
	381	{
	382	if (ax25->vs == nr) {
	383	ax25_frames_acked(ax25, nr);
	384	ax25_calculate_rtt(ax25);
	385	ax25_stop_t1timer(ax25);
	386	ax25_start_t3timer(ax25);
	387	return 1;
	388	} else {
	389	if (ax25->va != nr) {
	390	ax25_frames_acked(ax25, nr);
	391	ax25_calculate_t1(ax25);
	392	ax25_start_t1timer(ax25);
	393	return 1;
	394	}
	395	}
	396	return 0;
	397	}
	398