fsm.h

00001 /*
00002  * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
00003  *
00004  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
00005  *
00006  * Redistribution and use in source and binary forms, with or without
00007  * modification, are permitted provided that the following conditions
00008  * are met:
00009  *
00010  * 1. Redistributions of source code must retain the above copyright
00011  *    notice, this list of conditions and the following disclaimer.
00012  *
00013  * 2. Redistributions in binary form must reproduce the above copyright
00014  *    notice, this list of conditions and the following disclaimer in
00015  *    the documentation and/or other materials provided with the
00016  *    distribution.
00017  *
00018  * 3. The name "Carnegie Mellon University" must not be used to
00019  *    endorse or promote products derived from this software without
00020  *    prior written permission. For permission or any legal
00021  *    details, please contact
00022  *      Office of Technology Transfer
00023  *      Carnegie Mellon University
00024  *      5000 Forbes Avenue
00025  *      Pittsburgh, PA  15213-3890
00026  *      (412) 268-4387, fax: (412) 268-7395
00027  *      tech-transfer@andrew.cmu.edu
00028  *
00029  * 4. Redistributions of any form whatsoever must retain the following
00030  *    acknowledgment:
00031  *    "This product includes software developed by Computing Services
00032  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
00033  *
00034  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
00035  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
00036  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
00037  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
00038  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
00039  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
00040  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
00041  *
00042  * $Id: fsm.h,v 1.10 2004/11/13 02:28:15 paulus Exp $
00043  */
00044 
00045 #include "ppp_opts.h"
00046 #if PPP_SUPPORT /* don't build if not configured for use in ppp_opts.h */
00047 
00048 #ifndef FSM_H
00049 #define FSM_H
00050 
00051 #include "ppp.h"
00052 
00053 #ifdef __cplusplus
00054 extern "C" {
00055 #endif
00056 
00057 /*
00058  * Packet header = Code, id, length.
00059  */
00060 #define HEADERLEN   4
00061 
00062 
00063 /*
00064  *  CP (LCP, IPCP, etc.) codes.
00065  */
00066 #define CONFREQ     1   /* Configuration Request */
00067 #define CONFACK     2   /* Configuration Ack */
00068 #define CONFNAK     3   /* Configuration Nak */
00069 #define CONFREJ     4   /* Configuration Reject */
00070 #define TERMREQ     5   /* Termination Request */
00071 #define TERMACK     6   /* Termination Ack */
00072 #define CODEREJ     7   /* Code Reject */
00073 
00074 
00075 /*
00076  * Each FSM is described by an fsm structure and fsm callbacks.
00077  */
00078 typedef struct fsm {
00079     ppp_pcb *pcb;       /* PPP Interface */
00080     const struct fsm_callbacks *callbacks;  /* Callback routines */
00081     const char *term_reason;    /* Reason for closing protocol */
00082     u8_t seen_ack;      /* Have received valid Ack/Nak/Rej to Req */
00083                   /* -- This is our only flag, we might use u_int :1 if we have more flags */
00084     u16_t protocol;     /* Data Link Layer Protocol field value */
00085     u8_t state;         /* State */
00086     u8_t flags;         /* Contains option bits */
00087     u8_t id;            /* Current id */
00088     u8_t reqid;         /* Current request id */
00089     u8_t retransmits;       /* Number of retransmissions left */
00090     u8_t nakloops;      /* Number of nak loops since last ack */
00091     u8_t rnakloops;     /* Number of naks received */
00092     u8_t maxnakloops;       /* Maximum number of nak loops tolerated
00093                    (necessary because IPCP require a custom large max nak loops value) */
00094     u8_t term_reason_len;   /* Length of term_reason */
00095 } fsm;
00096 
00097 
00098 typedef struct fsm_callbacks {
00099     void (*resetci)     /* Reset our Configuration Information */
00100         (fsm *);
00101     int  (*cilen)       /* Length of our Configuration Information */
00102         (fsm *);
00103     void (*addci)       /* Add our Configuration Information */
00104         (fsm *, u_char *, int *);
00105     int  (*ackci)       /* ACK our Configuration Information */
00106         (fsm *, u_char *, int);
00107     int  (*nakci)       /* NAK our Configuration Information */
00108         (fsm *, u_char *, int, int);
00109     int  (*rejci)       /* Reject our Configuration Information */
00110         (fsm *, u_char *, int);
00111     int  (*reqci)       /* Request peer's Configuration Information */
00112         (fsm *, u_char *, int *, int);
00113     void (*up)          /* Called when fsm reaches PPP_FSM_OPENED state */
00114         (fsm *);
00115     void (*down)        /* Called when fsm leaves PPP_FSM_OPENED state */
00116         (fsm *);
00117     void (*starting)        /* Called when we want the lower layer */
00118         (fsm *);
00119     void (*finished)        /* Called when we don't want the lower layer */
00120         (fsm *);
00121     void (*protreject)      /* Called when Protocol-Reject received */
00122         (int);
00123     void (*retransmit)      /* Retransmission is necessary */
00124         (fsm *);
00125     int  (*extcode)     /* Called when unknown code received */
00126         (fsm *, int, int, u_char *, int);
00127     const char *proto_name; /* String name for protocol (for messages) */
00128 } fsm_callbacks;
00129 
00130 
00131 /*
00132  * Link states.
00133  */
00134 #define PPP_FSM_INITIAL     0   /* Down, hasn't been opened */
00135 #define PPP_FSM_STARTING    1   /* Down, been opened */
00136 #define PPP_FSM_CLOSED      2   /* Up, hasn't been opened */
00137 #define PPP_FSM_STOPPED     3   /* Open, waiting for down event */
00138 #define PPP_FSM_CLOSING     4   /* Terminating the connection, not open */
00139 #define PPP_FSM_STOPPING    5   /* Terminating, but open */
00140 #define PPP_FSM_REQSENT     6   /* We've sent a Config Request */
00141 #define PPP_FSM_ACKRCVD     7   /* We've received a Config Ack */
00142 #define PPP_FSM_ACKSENT     8   /* We've sent a Config Ack */
00143 #define PPP_FSM_OPENED      9   /* Connection available */
00144 
00145 
00146 /*
00147  * Flags - indicate options controlling FSM operation
00148  */
00149 #define OPT_PASSIVE 1   /* Don't die if we don't get a response */
00150 #define OPT_RESTART 2   /* Treat 2nd OPEN as DOWN, UP */
00151 #define OPT_SILENT  4   /* Wait for peer to speak first */
00152 
00153 
00154 /*
00155  * Timeouts.
00156  */
00157 #if 0 /* moved to ppp_opts.h */
00158 #define DEFTIMEOUT  3   /* Timeout time in seconds */
00159 #define DEFMAXTERMREQS  2   /* Maximum Terminate-Request transmissions */
00160 #define DEFMAXCONFREQS  10  /* Maximum Configure-Request transmissions */
00161 #define DEFMAXNAKLOOPS  5   /* Maximum number of nak loops */
00162 #endif /* moved to ppp_opts.h */
00163 
00164 
00165 /*
00166  * Prototypes
00167  */
00168 void fsm_init(fsm *f);
00169 void fsm_lowerup(fsm *f);
00170 void fsm_lowerdown(fsm *f);
00171 void fsm_open(fsm *f);
00172 void fsm_close(fsm *f, const char *reason);
00173 void fsm_input(fsm *f, u_char *inpacket, int l);
00174 void fsm_protreject(fsm *f);
00175 void fsm_sdata(fsm *f, u_char code, u_char id, const u_char *data, int datalen);
00176 
00177 #ifdef __cplusplus
00178 }
00179 #endif
00180 
00181 #endif /* FSM_H */
00182 #endif /* PPP_SUPPORT */