libexec/pppd/fsm.h

/*
 * fsm.h - {Link, IP} Control Protocol Finite State Machine 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.
 */

/*
 * Packet header = Code, id, length.
 */
#define HEADERLEN       (sizeof (u_char) + sizeof (u_char) + sizeof (u_short))


/*
 *  CP (LCP, IPCP, etc.) codes.
 */
#define CONFREQ         1       /* Configuration Request */
#define CONFACK         2       /* Configuration Ack */
#define CONFNAK         3       /* Configuration Nak */
#define CONFREJ         4       /* Configuration Reject */
#define TERMREQ         5       /* Termination Request */
#define TERMACK         6       /* Termination Ack */
#define CODEREJ         7       /* Code Reject */
#define PROTREJ         8       /* Protocol Reject */
#define ECHOREQ         9       /* Echo Request */
#define ECHOREP         10      /* Echo Reply */
#define DISCREQ         11      /* Discard Request */
#define KEEPALIVE       12      /* Keepalive */


/*
 * Each FSM is described by a fsm_callbacks and a fsm structure.
 */
typedef struct fsm_callbacks {
    void (*resetci)();          /* Reset our Configuration Information */
    int (*cilen)();             /* Length of our Configuration Information */
    void (*addci)();            /* Add our Configuration Information */
    int (*ackci)();             /* ACK our Configuration Information */
    void (*nakci)();            /* NAK our Configuration Information */
    void (*rejci)();            /* Reject our Configuration Information */
    u_char (*reqci)();          /* Request peer's Configuration Information */
    void (*up)();               /* Called when fsm reaches OPEN state */
    void (*down)();             /* Called when fsm leaves OPEN state */
    void (*closed)();           /* Called when fsm reaches CLOSED state */
    void (*protreject)();       /* Called when Protocol-Reject received */
    void (*retransmit)();       /* Retransmission is necessary */
} fsm_callbacks;


typedef struct fsm {
    int unit;                   /* Interface unit number */
    u_short protocol;           /* Data Link Layer Protocol field value */
    int state;                  /* State */
    int flags;                  /* Flags */
    u_char id;                  /* Current id */
    u_char reqid;               /* Current request id */
    int timeouttime;            /* Timeout time in milliseconds */
    int maxconfreqtransmits;    /* Maximum Configure-Request transmissions */
    int retransmits;            /* Number of retransmissions */
    int maxtermtransmits;       /* Maximum Terminate-Request transmissions */
    int nakloops;               /* Number of nak loops since last timeout */
    int maxnakloops;            /* Maximum number of nak loops tolerated */
    fsm_callbacks *callbacks;   /* Callback routines */
} fsm;


/*
 * Link states.
 */
#define CLOSED          1       /* Connection closed */
#define LISTEN          2       /* Listening for a Config Request */
#define REQSENT         3       /* We've sent a Config Request */
#define ACKSENT         4       /* We've sent a Config Ack */
#define ACKRCVD         5       /* We've received a Config Ack */
#define OPEN            6       /* Connection open */
#define TERMSENT        7       /* We've sent a Terminate Request */


/*
 * Flags.
 */
#define LOWERUP         1       /* The lower level is UP */
#define AOPENDING       2       /* Active Open pending timeout of request */
#define POPENDING       4       /* Passive Open pending timeout of request */


/*
 * Timeouts.
 */
#define DEFTIMEOUT      3       /* Timeout time in seconds */
#define DEFMAXTERMTRANSMITS 10  /* Maximum Terminate-Request transmissions */
#define DEFMAXCONFIGREQS 10     /* Maximum Configure-Request transmissions */


#define DEFMAXNAKLOOPS  10      /* Maximum number of nak loops */


void fsm_init __ARGS((fsm *));
void fsm_activeopen __ARGS((fsm *));
void fsm_passiveopen __ARGS((fsm *));
void fsm_close __ARGS((fsm *));
void fsm_lowerup __ARGS((fsm *));
void fsm_lowerdown __ARGS((fsm *));
void fsm_protreject __ARGS((fsm *));
void fsm_input __ARGS((fsm *, u_char *, int));
void fsm_sdata __ARGS((fsm *, int, int, u_char *, int));