drivers/net/slip/slip.h

   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
  50 struct 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 */