sys/net/if_ppp.h

/*
 * if_ppp.h - Point-to-Point Protocol definitions.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Modified by Paul Mackerras (paulus@cs.anu.edu.au)
 * Added PPP_MRU, sc_outm, sc_fastq, sc_bpf.
 *
 *      $Id$
 *      From: if_ppp.h,v 1.4 1993/08/29 11:22:37 paulus Exp $
 */

/*
 * Standard PPP header.
 */
struct ppp_header {
        u_char  ph_address;     /* Address Field */
        u_char  ph_control;     /* Control Field */
        u_short ph_protocol;    /* Protocol Field */
};

#define PPP_HEADER_LEN  4       /* octets, must == sizeof(struct ppp_header) */
#define PPP_FCS_LEN     2       /* octets for FCS */

#define PPP_ALLSTATIONS 0xff    /* All-Stations broadcast address */
#define PPP_UI          0x03    /* Unnumbered Information */
#define PPP_FLAG        0x7e    /* Flag Sequence */
#define PPP_ESCAPE      0x7d    /* Asynchronous Control Escape */
#define PPP_TRANS       0x20    /* Asynchronous transparency modifier */

/*
 * Protocol types.
 */
#define PPP_IP          0x21    /* Internet Protocol */
#define PPP_XNS         0x25    /* Xerox NS */
#define PPP_VJC_COMP    0x2d    /* VJ compressed TCP */
#define PPP_VJC_UNCOMP  0x2f    /* VJ uncompressed TCP */
#define PPP_LCP         0xc021  /* Link Control Protocol */

/*
 * Important FCS values.
 */
#define PPP_INITFCS     0xffff  /* Initial FCS value */
#define PPP_GOODFCS     0xf0b8  /* Good final FCS value */
#define PPP_FCS(fcs, c) (((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])

#define PPP_MTU         1500    /* Default MTU (size of Info field) */
#define PPP_MRU         1500    /* Default MRU (max receive unit) */
#define PPP_MAXMRU      65000   /* Largest MRU we allow */
#define PPP_HIWAT       400     /* Don't start a new packet if HIWAT on que */

struct ppp_softc {
        struct ifnet sc_if;     /* network-visible interface */
        u_int   sc_flags;       /* see below */
        struct  tty *sc_ttyp;   /* pointer to tty structure */
        struct  mbuf *sc_outm;  /* mbuf chain being output currently */
        struct  mbuf *sc_m;     /* pointer to input mbuf chain */
        struct  mbuf *sc_mc;    /* pointer to current input mbuf */
        char    *sc_mp;         /* pointer to next char in input mbuf */
        short   sc_ilen;        /* length of input-packet-so-far */
        u_short sc_fcs;         /* FCS so far (input) */
        u_short sc_outfcs;      /* FCS so far for output packet */
        short   sc_mru;         /* max receive unit */
        u_long  sc_asyncmap;    /* async control character map */
        u_long  sc_rasyncmap;   /* receive async control char map */
        struct  ifqueue sc_inq; /* TTY side input queue */
        struct  ifqueue sc_fastq; /* IP interactive output packet queue */
#ifdef  VJC
        struct  slcompress sc_comp; /* vjc control buffer */
#endif
        u_int   sc_bytessent;
        u_int   sc_bytesrcvd;
        caddr_t sc_bpf;
};

/* flags */
#define SC_COMP_PROT    0x00000001      /* protocol compression (output) */
#define SC_COMP_AC      0x00000002      /* header compression (output) */
#define SC_COMP_TCP     0x00000004      /* TCP (VJ) compression (output) */
#define SC_NO_TCP_CCID  0x00000008      /* disable VJ connection-id comp. */
#define SC_REJ_COMP_AC  0x00000010      /* reject adrs/ctrl comp. on input */
#define SC_REJ_COMP_TCP 0x00000020      /* reject TCP (VJ) comp. on input */
#define SC_MASK         0x0000ffff      /* bits that user can change */

/* state bits */
#define SC_ESCAPED      0x00010000      /* saw a PPP_ESCAPE */
#define SC_FLUSH        0x00020000      /* flush input until next PPP_FLAG */

#define t_sc T_LINEP

/* this stuff doesn't belong here... */
#define PPPIOCGFLAGS    _IOR('t', 90, int)      /* get configuration flags */
#define PPPIOCSFLAGS    _IOW('t', 89, int)      /* set configuration flags */
#define PPPIOCGASYNCMAP _IOR('t', 88, int)      /* get async map */
#define PPPIOCSASYNCMAP _IOW('t', 87, int)      /* set async map */
#define PPPIOCGUNIT     _IOR('t', 86, int)      /* get ppp unit number */
#define PPPIOCGRASYNCMAP _IOR('t', 85, int)     /* get receive async map */
#define PPPIOCSRASYNCMAP _IOW('t', 84, int)     /* set receive async map */
#define PPPIOCGMRU      _IOR('t', 83, int)      /* get max receive unit */
#define PPPIOCSMRU      _IOW('t', 82, int)      /* set max receive unit */

/* old copies of PPP may have defined this */
#if !defined(ifr_mtu)
#define ifr_mtu ifr_metric
#endif