pppd/fsm.h

   1 /*
   2  * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
   3  *
   4  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  *
  18  * 3. The name "Carnegie Mellon University" must not be used to
  19  *    endorse or promote products derived from this software without
  20  *    prior written permission. For permission or any legal
  21  *    details, please contact
  22  *      Office of Technology Transfer
  23  *      Carnegie Mellon University
  24  *      5000 Forbes Avenue
  25  *      Pittsburgh, PA  15213-3890
  26  *      (412) 268-4387, fax: (412) 268-7395
  27  *      tech-transfer@andrew.cmu.edu
  28  *
  29  * 4. Redistributions of any form whatsoever must retain the following
  30  *    acknowledgment:
  31  *    "This product includes software developed by Computing Services
  32  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
  33  *
  34  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
  35  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  36  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
  37  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  38  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
  39  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  40  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  41  *
  42  * $Id: fsm.h,v 1.10 2004/11/13 02:28:15 paulus Exp $
  43  */
  44
  45 /*
  46  * Packet header = Code, id, length.
  47  */
  48 #define HEADERLEN       4
  49
  50
  51 /*
  52  *  CP (LCP, IPCP, etc.) codes.
  53  */
  54 #define CONFREQ         1       /* Configuration Request */
  55 #define CONFACK         2       /* Configuration Ack */
  56 #define CONFNAK         3       /* Configuration Nak */
  57 #define CONFREJ         4       /* Configuration Reject */
  58 #define TERMREQ         5       /* Termination Request */
  59 #define TERMACK         6       /* Termination Ack */
  60 #define CODEREJ         7       /* Code Reject */
  61
  62
  63 /*
  64  * Each FSM is described by an fsm structure and fsm callbacks.
  65  */
  66 typedef struct fsm {
  67     int unit;                   /* Interface unit number */
  68     int protocol;               /* Data Link Layer Protocol field value */
  69     int state;                  /* State */
  70     int flags;                  /* Contains option bits */
  71     u_char id;                  /* Current id */
  72     u_char reqid;               /* Current request id */
  73     u_char seen_ack;            /* Have received valid Ack/Nak/Rej to Req */
  74     int timeouttime;            /* Timeout time in milliseconds */
  75     int maxconfreqtransmits;    /* Maximum Configure-Request transmissions */
  76     int retransmits;            /* Number of retransmissions left */
  77     int maxtermtransmits;       /* Maximum Terminate-Request transmissions */
  78     int nakloops;               /* Number of nak loops since last ack */
  79     int rnakloops;              /* Number of naks received */
  80     int maxnakloops;            /* Maximum number of nak loops tolerated */
  81     struct fsm_callbacks *callbacks;    /* Callback routines */
  82     char *term_reason;          /* Reason for closing protocol */
  83     int term_reason_len;        /* Length of term_reason */
  84 } fsm;
  85
  86
  87 typedef struct fsm_callbacks {
  88     void (*resetci)             /* Reset our Configuration Information */
  89                 __P((fsm *));
  90     int  (*cilen)               /* Length of our Configuration Information */
  91                 __P((fsm *));
  92     void (*addci)               /* Add our Configuration Information */
  93                 __P((fsm *, u_char *, int *));
  94     int  (*ackci)               /* ACK our Configuration Information */
  95                 __P((fsm *, u_char *, int));
  96     int  (*nakci)               /* NAK our Configuration Information */
  97                 __P((fsm *, u_char *, int, int));
  98     int  (*rejci)               /* Reject our Configuration Information */
  99                 __P((fsm *, u_char *, int));
 100     int  (*reqci)               /* Request peer's Configuration Information */
 101                 __P((fsm *, u_char *, int *, int));
 102     void (*up)                  /* Called when fsm reaches OPENED state */
 103                 __P((fsm *));
 104     void (*down)                /* Called when fsm leaves OPENED state */
 105                 __P((fsm *));
 106     void (*starting)            /* Called when we want the lower layer */
 107                 __P((fsm *));
 108     void (*finished)            /* Called when we don't want the lower layer */
 109                 __P((fsm *));
 110     void (*protreject)          /* Called when Protocol-Reject received */
 111                 __P((int));
 112     void (*retransmit)          /* Retransmission is necessary */
 113                 __P((fsm *));
 114     int  (*extcode)             /* Called when unknown code received */
 115                 __P((fsm *, int, int, u_char *, int));
 116     char *proto_name;           /* String name for protocol (for messages) */
 117 } fsm_callbacks;
 118
 119
 120 /*
 121  * Link states.
 122  */
 123 #define INITIAL         0       /* Down, hasn't been opened */
 124 #define STARTING        1       /* Down, been opened */
 125 #define CLOSED          2       /* Up, hasn't been opened */
 126 #define STOPPED         3       /* Open, waiting for down event */
 127 #define CLOSING         4       /* Terminating the connection, not open */
 128 #define STOPPING        5       /* Terminating, but open */
 129 #define REQSENT         6       /* We've sent a Config Request */
 130 #define ACKRCVD         7       /* We've received a Config Ack */
 131 #define ACKSENT         8       /* We've sent a Config Ack */
 132 #define OPENED          9       /* Connection available */
 133
 134
 135 /*
 136  * Flags - indicate options controlling FSM operation
 137  */
 138 #define OPT_PASSIVE     1       /* Don't die if we don't get a response */
 139 #define OPT_RESTART     2       /* Treat 2nd OPEN as DOWN, UP */
 140 #define OPT_SILENT      4       /* Wait for peer to speak first */
 141
 142
 143 /*
 144  * Timeouts.
 145  */
 146 #define DEFTIMEOUT      3       /* Timeout time in seconds */
 147 #define DEFMAXTERMREQS  2       /* Maximum Terminate-Request transmissions */
 148 #define DEFMAXCONFREQS  10      /* Maximum Configure-Request transmissions */
 149 #define DEFMAXNAKLOOPS  5       /* Maximum number of nak loops */
 150
 151
 152 /*
 153  * Prototypes
 154  */
 155 void fsm_init __P((fsm *));
 156 void fsm_lowerup __P((fsm *));
 157 void fsm_lowerdown __P((fsm *));
 158 void fsm_open __P((fsm *));
 159 void fsm_close __P((fsm *, char *));
 160 void fsm_input __P((fsm *, u_char *, int));
 161 void fsm_protreject __P((fsm *));
 162 void fsm_sdata __P((fsm *, int, int, u_char *, int));
 163
 164
 165 /*
 166  * Variables
 167  */
 168 extern int peer_mru[];          /* currently negotiated peer MRU (per unit) */