path: root/drivers/net/hamradio/mkiss.c

/*
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Copyright (C) Hans Alblas PE1AYX <hans@esrac.ele.tue.nl>
 * Copyright (C) 2004, 05 Ralf Baechle DL5RB <ralf@linux-mips.org>
 * Copyright (C) 2004, 05 Thomas Osterried DL9SAU <thomas@x-berg.in-berlin.de>
 */
#include <linux/module.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <asm/uaccess.h>
#include <linux/crc16.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/jiffies.h>

#include <net/ax25.h>

#define AX_MTU		236

/* SLIP/KISS protocol characters. */
#define END             0300		/* indicates end of frame	*/
#define ESC             0333		/* indicates byte stuffing	*/
#define ESC_END         0334		/* ESC ESC_END means END 'data'	*/
#define ESC_ESC         0335		/* ESC ESC_ESC means ESC 'data'	*/

struct mkiss {
	struct tty_struct	*tty;	/* ptr to TTY structure		*/
	struct net_device	*dev;	/* easy for intr handling	*/

	/* These are pointers to the malloc()ed frame buffers. */
	spinlock_t		buflock;/* lock for rbuf and xbuf */
	unsigned char		*rbuff;	/* receiver buffer		*/
	int			rcount;	/* received chars counter       */
	unsigned char		*xbuff;	/* transmitter buffer		*/
	unsigned char		*xhead;	/* pointer to next byte to XMIT */
	int			xleft;	/* bytes left in XMIT queue     */

	struct net_device_stats	stats;

	/* Detailed SLIP statistics. */
	int		mtu;		/* Our mtu (to spot changes!)   */
	int		buffsize;	/* Max buffers sizes            */

	unsigned long	flags;		/* Flag values/ mode etc	*/
					/* long req'd: used by set_bit --RR */
#define AXF_INUSE	0		/* Channel in use               */
#define AXF_ESCAPE	1               /* ESC received                 */
#define AXF_ERROR	2               /* Parity, etc. error           */
#define AXF_KEEPTEST	3		/* Keepalive test flag		*/
#define AXF_OUTWAIT	4		/* is outpacket was flag	*/

	int		mode;
        int		crcmode;	/* MW: for FlexNet, SMACK etc.  */
	int		crcauto;	/* CRC auto mode */

#define CRC_MODE_NONE		0
#define CRC_MODE_FLEX		1
#define CRC_MODE_SMACK		2
#define CRC_MODE_FLEX_TEST	3
#define CRC_MODE_SMACK_TEST	4

	atomic_t		refcnt;
	struct semaphore	dead_sem;
};

/*---------------------------------------------------------------------------*/

static const unsigned short crc_flex_table[] = {
	0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38,
	0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770,
	0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9,
	0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1,
	0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a,
	0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672,
	0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb,
	0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3,
	0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c,
	0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574,
	0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd,
	0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5,
	0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e,
	0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476,
	0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf,
	0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7,
	0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30,
	0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378,
	0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1,
	0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9,
	0xaa8d, 0xbb04,