[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 <net/sock.h>
#include <linux/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>
1da177e4	27	#include <net/sock.h>
7c0f6ba6	28	#include <linux/uaccess.h>
1da177e4 LT	29	#include <linux/fcntl.h>
	30	#include <linux/mm.h>
	31	#include <linux/interrupt.h>
	32
	33	static DEFINE_SPINLOCK(ax25_frag_lock);
	34
	35	ax25_cb ax25_send_frame(struct sk_buff skb, int paclen, ax25_address src, ax25_address dest, ax25_digi digi, struct net_device dev)
	36	{
	37	ax25_dev *ax25_dev;
	38	ax25_cb *ax25;
	39
	40	/*
	41	* Take the default packet length for the device if zero is
	42	* specified.
	43	*/
	44	if (paclen == 0) {
	45	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	46	return NULL;
	47
	48	paclen = ax25_dev->values[AX25_VALUES_PACLEN];
	49	}
	50
	51	/*
	52	* Look for an existing connection.
	53	*/
	54	if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
	55	ax25_output(ax25, paclen, skb);
	56	return ax25; /* It already existed */
	57	}
	58
	59	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
	60	return NULL;
	61
	62	if ((ax25 = ax25_create_cb()) == NULL)
	63	return NULL;
	64
	65	ax25_fillin_cb(ax25, ax25_dev);
	66
	67	ax25->source_addr = *src;
	68	ax25->dest_addr = *dest;
	69
	70	if (digi != NULL) {
0459d70a ACM	71	ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
0459d70a ACM	72	if (ax25->digipeat == NULL) {
1da177e4 LT	73	ax25_cb_put(ax25);
	74	return NULL;
	75	}
1da177e4 LT	76	}
	77
	78	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	79	case AX25_PROTO_STD_SIMPLEX:
	80	case AX25_PROTO_STD_DUPLEX:
	81	ax25_std_establish_data_link(ax25);
	82	break;
	83
	84	#ifdef CONFIG_AX25_DAMA_SLAVE
	85	case AX25_PROTO_DAMA_SLAVE:
	86	if (ax25_dev->dama.slave)
	87	ax25_ds_establish_data_link(ax25);
	88	else
	89	ax25_std_establish_data_link(ax25);
	90	break;
	91	#endif
	92	}
	93
d00c362f JP	94	/*
	95	* There is one ref for the state machine; a caller needs
	96	* one more to put it back, just like with the existing one.
	97	*/
	98	ax25_cb_hold(ax25);
	99
1da177e4 LT	100	ax25_cb_add(ax25);
	101
	102	ax25->state = AX25_STATE_1;
	103
	104	ax25_start_heartbeat(ax25);
	105
	106	ax25_output(ax25, paclen, skb);
	107
	108	return ax25; /* We had to create it */
	109	}
	110
70868eac RB	111	EXPORT_SYMBOL(ax25_send_frame);
70868eac RB	112
1da177e4 LT	113	/*
	114	* All outgoing AX.25 I frames pass via this routine. Therefore this is
	115	* where the fragmentation of frames takes place. If fragment is set to
	116	* zero then we are not allowed to do fragmentation, even if the frame
	117	* is too large.
	118	*/
	119	void ax25_output(ax25_cb ax25, int paclen, struct sk_buff skb)
	120	{
	121	struct sk_buff *skbn;
	122	unsigned char *p;
	123	int frontlen, len, fragno, ka9qfrag, first = 1;
	124
f47b7257 JP	125	if (paclen < 16) {
	126	WARN_ON_ONCE(1);
	127	kfree_skb(skb);
	128	return;
	129	}
	130
1da177e4 LT	131	if ((skb->len - 1) > paclen) {
	132	if (*skb->data == AX25_P_TEXT) {
	133	skb_pull(skb, 1); /* skip PID */
	134	ka9qfrag = 0;
	135	} else {
	136	paclen -= 2; /* Allow for fragment control info */
	137	ka9qfrag = 1;
	138	}
	139
	140	fragno = skb->len / paclen;
	141	if (skb->len % paclen == 0) fragno--;
	142
	143	frontlen = skb_headroom(skb); /* Address space + CTRL */
	144
	145	while (skb->len > 0) {
	146	spin_lock_bh(&ax25_frag_lock);
	147	if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
	148	spin_unlock_bh(&ax25_frag_lock);
	149	printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
	150	return;
	151	}
	152
	153	if (skb->sk != NULL)
	154	skb_set_owner_w(skbn, skb->sk);
	155
	156	spin_unlock_bh(&ax25_frag_lock);
	157
	158	len = (paclen > skb->len) ? skb->len : paclen;
	159
	160	if (ka9qfrag == 1) {
	161	skb_reserve(skbn, frontlen + 2);
c14d2450 ACM	162	skb_set_network_header(skbn,
c14d2450 ACM	163	skb_network_offset(skb));
d626f62b	164	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	165	p = skb_push(skbn, 2);
	166
	167	*p++ = AX25_P_SEGMENT;
	168
	169	*p = fragno--;
	170	if (first) {
	171	*p \|= AX25_SEG_FIRST;
	172	first = 0;
	173	}
	174	} else {
	175	skb_reserve(skbn, frontlen + 1);
c14d2450 ACM	176	skb_set_network_header(skbn,
c14d2450 ACM	177	skb_network_offset(skb));
d626f62b	178	skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
1da177e4 LT	179	p = skb_push(skbn, 1);
	180	*p = AX25_P_TEXT;
	181	}
	182
	183	skb_pull(skb, len);
	184	skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
	185	}
	186
	187	kfree_skb(skb);
	188	} else {
	189	skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
	190	}
	191
	192	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	193	case AX25_PROTO_STD_SIMPLEX:
	194	case AX25_PROTO_STD_DUPLEX:
	195	ax25_kick(ax25);
	196	break;
	197
	198	#ifdef CONFIG_AX25_DAMA_SLAVE
	199	/*
	200	* A DAMA slave is _required_ to work as normal AX.25L2V2
	201	* if no DAMA master is available.
	202	*/
	203	case AX25_PROTO_DAMA_SLAVE:
	204	if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
	205	break;
	206	#endif
	207	}
	208	}
	209
	210	/*
	211	* This procedure is passed a buffer descriptor for an iframe. It builds
	212	* the rest of the control part of the frame and then writes it out.
	213	*/
	214	static void ax25_send_iframe(ax25_cb ax25, struct sk_buff skb, int poll_bit)
	215	{
	216	unsigned char *frame;
	217
	218	if (skb == NULL)
	219	return;
	220
c1d2bbe1	221	skb_reset_network_header(skb);
1da177e4 LT	222
	223	if (ax25->modulus == AX25_MODULUS) {
	224	frame = skb_push(skb, 1);
	225
	226	*frame = AX25_I;
	227	*frame \|= (poll_bit) ? AX25_PF : 0;
	228	*frame \|= (ax25->vr << 5);
	229	*frame \|= (ax25->vs << 1);
	230	} else {
	231	frame = skb_push(skb, 2);
	232
	233	frame[0] = AX25_I;
	234	frame[0] \|= (ax25->vs << 1);
	235	frame[1] = (poll_bit) ? AX25_EPF : 0;
	236	frame[1] \|= (ax25->vr << 1);
	237	}
	238
	239	ax25_start_idletimer(ax25);
	240
	241	ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
	242	}
	243
	244	void ax25_kick(ax25_cb *ax25)
	245	{
	246	struct sk_buff skb, skbn;
	247	int last = 1;
	248	unsigned short start, end, next;
	249
	250	if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
	251	return;
	252
	253	if (ax25->condition & AX25_COND_PEER_RX_BUSY)
	254	return;
	255
	256	if (skb_peek(&ax25->write_queue) == NULL)
	257	return;
	258
	259	start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
	260	end = (ax25->va + ax25->window) % ax25->modulus;
	261
	262	if (start == end)
	263	return;
	264
1da177e4 LT	265	/*
	266	* Transmit data until either we're out of data to send or
	267	* the window is full. Send a poll on the final I frame if
	268	* the window is filled.
	269	*/
	270
	271	/*
	272	* Dequeue the frame and copy it.
f47b7257	273	* Check for race with ax25_clear_queues().
1da177e4 LT	274	*/
1da177e4 LT	275	skb = skb_dequeue(&ax25->write_queue);
f47b7257 JP	276	if (!skb)
	277	return;
	278
	279	ax25->vs = start;
1da177e4 LT	280
	281	do {
	282	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
	283	skb_queue_head(&ax25->write_queue, skb);
	284	break;
	285	}
	286
	287	if (skb->sk != NULL)
	288	skb_set_owner_w(skbn, skb->sk);
	289
	290	next = (ax25->vs + 1) % ax25->modulus;
	291	last = (next == end);
	292
	293	/*
	294	* Transmit the frame copy.
	295	* bke 960114: do not set the Poll bit on the last frame
	296	* in DAMA mode.
	297	*/
	298	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	299	case AX25_PROTO_STD_SIMPLEX:
	300	case AX25_PROTO_STD_DUPLEX:
	301	ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
	302	break;
	303
	304	#ifdef CONFIG_AX25_DAMA_SLAVE
	305	case AX25_PROTO_DAMA_SLAVE:
	306	ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
	307	break;
	308	#endif
	309	}
	310
	311	ax25->vs = next;
	312
	313	/*
	314	* Requeue the original data frame.
	315	*/
	316	skb_queue_tail(&ax25->ack_queue, skb);
	317
	318	} while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);
	319
	320	ax25->condition &= ~AX25_COND_ACK_PENDING;
	321
	322	if (!ax25_t1timer_running(ax25)) {
	323	ax25_stop_t3timer(ax25);
	324	ax25_calculate_t1(ax25);
	325	ax25_start_t1timer(ax25);
	326	}
	327	}
	328
	329	void ax25_transmit_buffer(ax25_cb ax25, struct sk_buff skb, int type)
	330	{
	331	struct sk_buff *skbn;
	332	unsigned char *ptr;
	333	int headroom;
	334
	335	if (ax25->ax25_dev == NULL) {
	336	ax25_disconnect(ax25, ENETUNREACH);
	337	return;
	338	}
	339
	340	headroom = ax25_addr_size(ax25->digipeat);
	341
	342	if (skb_headroom(skb) < headroom) {
	343	if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
344	printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
345	kfree_skb(skb);
346	return;
347	}
348
349	if (skb->sk != NULL)
350	skb_set_owner_w(skbn, skb->sk);
351
5d0ba55b	352	consume_skb(skb);
1da177e4 LT	353	skb = skbn;
	354	}
	355
	356	ptr = skb_push(skb, headroom);
	357
	358	ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
	359
29c4be51	360	ax25_queue_xmit(skb, ax25->ax25_dev->dev);
1da177e4 LT	361	}
	362
	363	/*
	364	* A small shim to dev_queue_xmit to add the KISS control byte, and do
	365	* any packet forwarding in operation.
	366	*/
29c4be51	367	void ax25_queue_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	368	{
	369	unsigned char *ptr;
	370
56cb5156	371	skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(dev));
1da177e4 LT	372
	373	ptr = skb_push(skb, 1);
	374	ptr = 0x00; / KISS */
	375
	376	dev_queue_xmit(skb);
	377	}
	378
	379	int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
	380	{
	381	if (ax25->vs == nr) {
	382	ax25_frames_acked(ax25, nr);
	383	ax25_calculate_rtt(ax25);
	384	ax25_stop_t1timer(ax25);
	385	ax25_start_t3timer(ax25);
	386	return 1;
	387	} else {
	388	if (ax25->va != nr) {
	389	ax25_frames_acked(ax25, nr);
	390	ax25_calculate_t1(ax25);
	391	ax25_start_t1timer(ax25);
	392	return 1;
	393	}
	394	}
	395	return 0;
	396	}
	397