[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 <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
	}

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