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 /* some arch define END as assembly function ending, just undef it */
44 #undef	END
45 /* SLIP protocol characters. */
46 #define END             0300		/* indicates end of frame	*/
47 #define ESC             0333		/* indicates byte stuffing	*/
48 #define ESC_END         0334		/* ESC ESC_END means END 'data'	*/
49 #define ESC_ESC         0335		/* ESC ESC_ESC means ESC 'data'	*/
50 
51 
52 struct slip {
53   int			magic;
54 
55   /* Various fields. */
56   struct tty_struct	*tty;		/* ptr to TTY structure		*/
57   struct net_device	*dev;		/* easy for intr handling	*/
58   spinlock_t		lock;
59   struct work_struct	tx_work;	/* Flushes transmit buffer	*/
60 
61 #ifdef SL_INCLUDE_CSLIP
62   struct slcompress	*slcomp;	/* for header compression 	*/
63   unsigned char		*cbuff;		/* compression buffer		*/
64 #endif
65 
66   /* These are pointers to the malloc()ed frame buffers. */
67   unsigned char		*rbuff;		/* receiver buffer		*/
68   int                   rcount;         /* received chars counter       */
69   unsigned char		*xbuff;		/* transmitter buffer		*/
70   unsigned char         *xhead;         /* pointer to next byte to XMIT */
71   int                   xleft;          /* bytes left in XMIT queue     */
72   int			mtu;		/* Our mtu (to spot changes!)   */
73   int                   buffsize;       /* Max buffers sizes            */
74 
75 #ifdef CONFIG_SLIP_MODE_SLIP6
76   int			xdata, xbits;	/* 6 bit slip controls 		*/
77 #endif
78 
79   unsigned long		flags;		/* Flag values/ mode etc	*/
80 #define SLF_INUSE	0		/* Channel in use               */
81 #define SLF_ESCAPE	1               /* ESC received                 */
82 #define SLF_ERROR	2               /* Parity, etc. error           */
83 #define SLF_KEEPTEST	3		/* Keepalive test flag		*/
84 #define SLF_OUTWAIT	4		/* is outpacket was flag	*/
85 
86   unsigned char		mode;		/* SLIP mode			*/
87   unsigned char		leased;
88   pid_t			pid;
89 #define SL_MODE_SLIP	0
90 #define SL_MODE_CSLIP	1
91 #define SL_MODE_SLIP6	2		/* Matt Dillon's printable slip */
92 #define SL_MODE_CSLIP6	(SL_MODE_SLIP6|SL_MODE_CSLIP)
93 #define SL_MODE_AX25	4
94 #define SL_MODE_ADAPTIVE 8
95 #ifdef CONFIG_SLIP_SMART
96   unsigned char		outfill;	/* # of sec between outfill packet */
97   unsigned char		keepalive;	/* keepalive seconds		*/
98   struct timer_list	outfill_timer;
99   struct timer_list	keepalive_timer;
100 #endif
101 };
102 
103 #define SLIP_MAGIC 0x5302
104 
105 #endif	/* _LINUX_SLIP.H */
106