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| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
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| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ax25/ax25_ds_subr.c | |
| download | olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip  | |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/ax25/ax25_ds_subr.c')
| -rw-r--r-- | net/ax25/ax25_ds_subr.c | 212 | 
1 files changed, 212 insertions, 0 deletions
diff --git a/net/ax25/ax25_ds_subr.c b/net/ax25/ax25_ds_subr.c new file mode 100644 index 00000000000..10ffd2beba3 --- /dev/null +++ b/net/ax25/ax25_ds_subr.c @@ -0,0 +1,212 @@ +/* + * 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) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) + * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) + */ +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/sched.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 <net/sock.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> + +void ax25_ds_nr_error_recovery(ax25_cb *ax25) +{ +	ax25_ds_establish_data_link(ax25); +} + +/* + *	dl1bke 960114: transmit I frames on DAMA poll + */ +void ax25_ds_enquiry_response(ax25_cb *ax25) +{ +	ax25_cb *ax25o; +	struct hlist_node *node; + +	/* Please note that neither DK4EG´s nor DG2FEF´s +	 * DAMA spec mention the following behaviour as seen +	 * with TheFirmware: +	 * +	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA] +	 *	DL1BKE->DB0ACH <I NR=0 NS=0> +	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> +	 *	DL1BKE->DB0ACH <RR R F R0> +	 * +	 * The Flexnet DAMA Master implementation apparently +	 * insists on the "proper" AX.25 behaviour: +	 * +	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA] +	 *	DL1BKE->DB0ACH <RR R F R0> +	 *	DL1BKE->DB0ACH <I NR=0 NS=0> +	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> +	 * +	 * Flexnet refuses to send us *any* I frame if we send +	 * a REJ in case AX25_COND_REJECT is set. It is superfluous in +	 * this mode anyway (a RR or RNR invokes the retransmission). +	 * Is this a Flexnet bug? +	 */ + +	ax25_std_enquiry_response(ax25); + +	if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) { +		ax25_requeue_frames(ax25); +		ax25_kick(ax25); +	} + +	if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL) +		ax25_ds_t1_timeout(ax25); +	else +		ax25->n2count = 0; + +	ax25_start_t3timer(ax25); +	ax25_ds_set_timer(ax25->ax25_dev); + +	spin_lock_bh(&ax25_list_lock); +	ax25_for_each(ax25o, node, &ax25_list) { +		if (ax25o == ax25) +			continue; + +		if (ax25o->ax25_dev != ax25->ax25_dev) +			continue; + +		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) { +			ax25_ds_t1_timeout(ax25o); +			continue; +		} + +		if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) { +			ax25_requeue_frames(ax25o); +			ax25_kick(ax25o); +		} + +		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL) +			ax25_ds_t1_timeout(ax25o); + +		/* do not start T3 for listening sockets (tnx DD8NE) */ + +		if (ax25o->state != AX25_STATE_0) +			ax25_start_t3timer(ax25o); +	} +	spin_unlock_bh(&ax25_list_lock); +} + +void ax25_ds_establish_data_link(ax25_cb *ax25) +{ +	ax25->condition &= AX25_COND_DAMA_MODE; +	ax25->n2count    = 0; +	ax25_calculate_t1(ax25); +	ax25_start_t1timer(ax25); +	ax25_stop_t2timer(ax25); +	ax25_start_t3timer(ax25); +} + +/* + *	:::FIXME::: + *	This is a kludge. Not all drivers recognize kiss commands. + *	We need a driver level  request to switch duplex mode, that does + *	either SCC changing, PI config or KISS as required. Currently + *	this request isn't reliable. + */ +static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param) +{ +	struct sk_buff *skb; +	unsigned char *p; + +	if (ax25_dev->dev == NULL) +		return; + +	if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL) +		return; + +	skb->nh.raw = skb->data; +	p = skb_put(skb, 2); + +	*p++ = cmd; +	*p++ = param; + +	skb->dev      = ax25_dev->dev; +	skb->protocol = htons(ETH_P_AX25); + +	dev_queue_xmit(skb); +} + +/* + *	A nasty problem arises if we count the number of DAMA connections + *	wrong, especially when connections on the device already existed + *	and our network node (or the sysop) decides to turn on DAMA Master + *	mode. We thus flag the 'real' slave connections with + *	ax25->dama_slave=1 and look on every disconnect if still slave + *	connections exist. + */ +static int ax25_check_dama_slave(ax25_dev *ax25_dev) +{ +	ax25_cb *ax25; +	int res = 0; +	struct hlist_node *node; + +	spin_lock_bh(&ax25_list_lock); +	ax25_for_each(ax25, node, &ax25_list) +		if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) { +			res = 1; +			break; +		} +	spin_unlock_bh(&ax25_list_lock); + +	return res; +} + +static void ax25_dev_dama_on(ax25_dev *ax25_dev) +{ +	if (ax25_dev == NULL) +		return; + +	if (ax25_dev->dama.slave == 0) +		ax25_kiss_cmd(ax25_dev, 5, 1); + +	ax25_dev->dama.slave = 1; +	ax25_ds_set_timer(ax25_dev); +} + +void ax25_dev_dama_off(ax25_dev *ax25_dev) +{ +	if (ax25_dev == NULL) +		return; + +	if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) { +		ax25_kiss_cmd(ax25_dev, 5, 0); +		ax25_dev->dama.slave = 0; +		ax25_ds_del_timer(ax25_dev); +	} +} + +void ax25_dama_on(ax25_cb *ax25) +{ +	ax25_dev_dama_on(ax25->ax25_dev); +	ax25->condition |= AX25_COND_DAMA_MODE; +} + +void ax25_dama_off(ax25_cb *ax25) +{ +	ax25->condition &= ~AX25_COND_DAMA_MODE; +	ax25_dev_dama_off(ax25->ax25_dev); +} +  |