1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * slip.h	Define the SLIP device driver interface and constants.
  4 *
  5 * NOTE:	THIS FILE WILL BE MOVED TO THE LINUX INCLUDE DIRECTORY
  6 *		AS SOON AS POSSIBLE!
  7 *
  8 * Version:	@(#)slip.h	1.2.0	03/28/93
  9 *
 10 * Fixes:
 11 *		Alan Cox	: 	Added slip mtu field.
 12 *		Matt Dillon	:	Printable slip (borrowed from net2e)
 13 *		Alan Cox	:	Added SL_SLIP_LOTS
 14 *	Dmitry Gorodchanin	:	A lot of changes in the 'struct slip'
 15 *	Dmitry Gorodchanin	:	Added CSLIP statistics.
 16 *	Stanislav Voronyi	:	Make line checking as created by
 17 *					Igor Chechik, RELCOM Corp.
 18 *	Craig Schlenter		:	Fixed #define bug that caused
 19 *					CSLIP telnets to hang in 1.3.61-6
 20 *
 21 * Author:	Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
 22 */
 23#ifndef _LINUX_SLIP_H
 24#define _LINUX_SLIP_H
 25
 26
 27#if defined(CONFIG_INET) && defined(CONFIG_SLIP_COMPRESSED)
 28# define SL_INCLUDE_CSLIP
 29#endif
 30
 31#ifdef SL_INCLUDE_CSLIP
 32# define SL_MODE_DEFAULT SL_MODE_ADAPTIVE
 33#else
 34# define SL_MODE_DEFAULT SL_MODE_SLIP
 35#endif
 36
 37/* SLIP configuration. */
 38#define SL_NRUNIT	256		/* MAX number of SLIP channels;
 39					   This can be overridden with
 40					   insmod -oslip_maxdev=nnn	*/
 41#define SL_MTU		296		/* 296; I am used to 600- FvK	*/
 42
 43/* SLIP protocol characters. */
 44#define END             0300		/* indicates end of frame	*/
 45#define ESC             0333		/* indicates byte stuffing	*/
 46#define ESC_END         0334		/* ESC ESC_END means END 'data'	*/
 47#define ESC_ESC         0335		/* ESC ESC_ESC means ESC 'data'	*/
 48
 49
 50struct slip {
 51  int			magic;
 52
 53  /* Various fields. */
 54  struct tty_struct	*tty;		/* ptr to TTY structure		*/
 55  struct net_device	*dev;		/* easy for intr handling	*/
 56  spinlock_t		lock;
 57  struct work_struct	tx_work;	/* Flushes transmit buffer	*/
 58
 59#ifdef SL_INCLUDE_CSLIP
 60  struct slcompress	*slcomp;	/* for header compression 	*/
 61  unsigned char		*cbuff;		/* compression buffer		*/
 62#endif
 63
 64  /* These are pointers to the malloc()ed frame buffers. */
 65  unsigned char		*rbuff;		/* receiver buffer		*/
 66  int                   rcount;         /* received chars counter       */
 67  unsigned char		*xbuff;		/* transmitter buffer		*/
 68  unsigned char         *xhead;         /* pointer to next byte to XMIT */
 69  int                   xleft;          /* bytes left in XMIT queue     */
 70  int			mtu;		/* Our mtu (to spot changes!)   */
 71  int                   buffsize;       /* Max buffers sizes            */
 72
 73#ifdef CONFIG_SLIP_MODE_SLIP6
 74  int			xdata, xbits;	/* 6 bit slip controls 		*/
 75#endif
 76
 77  unsigned long		flags;		/* Flag values/ mode etc	*/
 78#define SLF_INUSE	0		/* Channel in use               */
 79#define SLF_ESCAPE	1               /* ESC received                 */
 80#define SLF_ERROR	2               /* Parity, etc. error           */
 81#define SLF_KEEPTEST	3		/* Keepalive test flag		*/
 82#define SLF_OUTWAIT	4		/* is outpacket was flag	*/
 83
 84  unsigned char		mode;		/* SLIP mode			*/
 85  unsigned char		leased;
 86  pid_t			pid;
 87#define SL_MODE_SLIP	0
 88#define SL_MODE_CSLIP	1
 89#define SL_MODE_SLIP6	2		/* Matt Dillon's printable slip */
 90#define SL_MODE_CSLIP6	(SL_MODE_SLIP6|SL_MODE_CSLIP)
 91#define SL_MODE_AX25	4
 92#define SL_MODE_ADAPTIVE 8
 93#ifdef CONFIG_SLIP_SMART
 94  unsigned char		outfill;	/* # of sec between outfill packet */
 95  unsigned char		keepalive;	/* keepalive seconds		*/
 96  struct timer_list	outfill_timer;
 97  struct timer_list	keepalive_timer;
 98#endif
 99};
100
101#define SLIP_MAGIC 0x5302
102
103#endif	/* _LINUX_SLIP.H */