text: /*
   * pppd.h - PPP daemon global declarations.
   *
   * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The name "Carnegie Mellon University" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For permission or any legal
   *    details, please contact
   *      Office of Technology Transfer
   *      Carnegie Mellon University
   *      5000 Forbes Avenue
   *      Pittsburgh, PA  15213-3890
   *      (412) 268-4387, fax: (412) 268-7395
   *      tech-transfer@andrew.cmu.edu
   *
   * 4. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by Computing Services
   *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
   *
   * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
   * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
   * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
   * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
   * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
   * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   *
   * $Id: pppd.h,v 1.88 2004/11/13 12:02:22 paulus Exp $
   */
  
  /*
   * TODO:
   */
  
  #ifndef __PPPD_H__
  #define __PPPD_H__
  
  #include <stdio.h>		/* for FILE */
  #include <limits.h>		/* for NGROUPS_MAX */
  #include <sys/param.h>		/* for MAXPATHLEN and BSD4_4, if defined */
  #include <sys/types.h>		/* for u_int32_t, if defined */
  #include <sys/time.h>		/* for struct timeval */
  #include <net/ppp_defs.h>
  #include "patchlevel.h"
  
  #if defined(__STDC__)
  #include <stdarg.h>
  #define __V(x)	x
  #else
  #include <varargs.h>
  #define __V(x)	(va_alist) va_dcl
  #define const
  #define volatile
  #endif
  
  #ifdef INET6
  #include "eui64.h"
  #endif
  
  /*
   * Limits.
   */
  
  #define NUM_PPP		1	/* One PPP interface supported (per process) */
  #define MAXWORDLEN	1024	/* max length of word in file (incl null) */
  #define MAXARGS		1	/* max # args to a command */
  #define MAXNAMELEN	256	/* max length of hostname or name for auth */
  #define MAXSECRETLEN	256	/* max length of password or secret */
  
  /*
   * Option descriptor structure.
   */
  
  typedef unsigned char	bool;
  
  enum opt_type {
  	o_special_noarg = 0,
  	o_special = 1,
  	o_bool,
  	o_int,
  	o_uint32,
  	o_string,
  	o_wild
  };
  
  typedef struct {
  	char	*name;		/* name of the option */
  	enum opt_type type;
  	void	*addr;
  	char	*description;
  	unsigned int flags;
  	void	*addr2;
  	int	upper_limit;
  	int	lower_limit;
  	const char *source;
  	short int priority;
  	short int winner;
  } option_t;
  
  /* Values for flags */
  #define OPT_VALUE	0xff	/* mask for presupplied value */
  #define OPT_HEX		0x100	/* int option is in hex */
  #define OPT_NOARG	0x200	/* option doesn't take argument */
  #define OPT_OR		0x400	/* OR in argument to value */
  #define OPT_INC		0x800	/* increment value */
  #define OPT_A2OR	0x800	/* for o_bool, OR arg to *(u_char *)addr2 */
  #define OPT_PRIV	0x1000	/* privileged option */
  #define OPT_STATIC	0x2000	/* string option goes into static array */
  #define OPT_LLIMIT	0x4000	/* check value against lower limit */
  #define OPT_ULIMIT	0x8000	/* check value against upper limit */
  #define OPT_LIMITS	(OPT_LLIMIT|OPT_ULIMIT)
  #define OPT_ZEROOK	0x10000	/* 0 value is OK even if not within limits */
  #define OPT_HIDE	0x10000	/* for o_string, print value as ?????? */
  #define OPT_A2LIST	0x10000 /* for o_special, keep list of values */
  #define OPT_A2CLRB	0x10000 /* o_bool, clr val bits in *(u_char *)addr2 */
  #define OPT_NOINCR	0x20000	/* value mustn't be increased */
  #define OPT_ZEROINF	0x40000	/* with OPT_NOINCR, 0 == infinity */
  #define OPT_PRIO	0x80000	/* process option priorities for this option */
  #define OPT_PRIOSUB	0x100000 /* subsidiary member of priority group */
  #define OPT_ALIAS	0x200000 /* option is alias for previous option */
  #define OPT_A2COPY	0x400000 /* addr2 -> second location to rcv value */
  #define OPT_ENABLE	0x800000 /* use *addr2 as enable for option */
  #define OPT_A2CLR	0x1000000 /* clear *(bool *)addr2 */
  #define OPT_PRIVFIX	0x2000000 /* user can't override if set by root */
  #define OPT_INITONLY	0x4000000 /* option can only be set in init phase */
  #define OPT_DEVEQUIV	0x8000000 /* equiv to device name */
  #define OPT_DEVNAM	(OPT_INITONLY | OPT_DEVEQUIV)
  #define OPT_A2PRINTER	0x10000000 /* *addr2 is a fn for printing option */
  #define OPT_A2STRVAL	0x20000000 /* *addr2 points to current string value */
  #define OPT_NOPRINT	0x40000000 /* don't print this option at all */
  
  #define OPT_VAL(x)	((x) & OPT_VALUE)
  
  /* Values for priority */
  #define OPRIO_DEFAULT	0	/* a default value */
  #define OPRIO_CFGFILE	1	/* value from a configuration file */
  #define OPRIO_CMDLINE	2	/* value from the command line */
  #define OPRIO_SECFILE	3	/* value from options in a secrets file */
  #define OPRIO_ROOT	100	/* added to priority if OPT_PRIVFIX && root */
  
  #ifndef GIDSET_TYPE
  #define GIDSET_TYPE	gid_t
  #endif
  
  /* Structure representing a list of permitted IP addresses. */
  struct permitted_ip {
      int		permit;		/* 1 = permit, 0 = forbid */
      u_int32_t	base;		/* match if (addr & mask) == base */
      u_int32_t	mask;		/* base and mask are in network byte order */
  };
  
  /*
   * Unfortunately, the linux kernel driver uses a different structure
   * for statistics from the rest of the ports.
   * This structure serves as a common representation for the bits
   * pppd needs.
   */
  struct pppd_stats {
      unsigned int	bytes_in;
      unsigned int	bytes_out;
      unsigned int	pkts_in;
      unsigned int	pkts_out;
  };
  
  /* Used for storing a sequence of words.  Usually malloced. */
  struct wordlist {
      struct wordlist	*next;
      char		*word;
  };
  
  /* An endpoint discriminator, used with multilink. */
  #define MAX_ENDP_LEN	20	/* maximum length of discriminator value */
  struct epdisc {
      unsigned char	class;
      unsigned char	length;
      unsigned char	value[MAX_ENDP_LEN];
  };
  
  /* values for epdisc.class */
  #define EPD_NULL	0	/* null discriminator, no data */
  #define EPD_LOCAL	1
  #define EPD_IP		2
  #define EPD_MAC		3
  #define EPD_MAGIC	4
  #define EPD_PHONENUM	5
  
  typedef void (*notify_func) __P((void *, int));
  
  struct notifier {
      struct notifier *next;
      notify_func	    func;
      void	    *arg;
  };
  
  /*
   * Global variables.
   */
  
  extern int	hungup;		/* Physical layer has disconnected */
  extern int	ifunit;		/* Interface unit number */
  extern char	ifname[];	/* Interface name */
  extern char	hostname[];	/* Our hostname */
  extern u_char	outpacket_buf[]; /* Buffer for outgoing packets */
  extern int	devfd;		/* fd of underlying device */
  extern int	fd_ppp;		/* fd for talking PPP */
  extern int	phase;		/* Current state of link - see values below */
  extern int	baud_rate;	/* Current link speed in bits/sec */
  extern char	*progname;	/* Name of this program */
  extern int	redirect_stderr;/* Connector's stderr should go to file */
  extern char	peer_authname[];/* Authenticated name of peer */
  extern int	auth_done[NUM_PPP]; /* Methods actually used for auth */
  extern int	privileged;	/* We were run by real-uid root */
  extern int	need_holdoff;	/* Need holdoff period after link terminates */
  extern char	**script_env;	/* Environment variables for scripts */
  extern int	detached;	/* Have detached from controlling tty */
  extern GIDSET_TYPE groups[NGROUPS_MAX];	/* groups the user is in */
  extern int	ngroups;	/* How many groups valid in groups */
  extern struct pppd_stats link_stats; /* byte/packet counts etc. for link */
  extern int	link_stats_valid; /* set if link_stats is valid */
  extern unsigned	link_connect_time; /* time the link was up for */
  extern int	using_pty;	/* using pty as device (notty or pty opt.) */
  extern int	log_to_fd;	/* logging to this fd as well as syslog */
  extern bool	log_default;	/* log_to_fd is default (stdout) */
  extern char	*no_ppp_msg;	/* message to print if ppp not in kernel */
  extern volatile int status;	/* exit status for pppd */
  extern bool	devnam_fixed;	/* can no longer change devnam */
  extern int	unsuccess;	/* # unsuccessful connection attempts */
  extern int	do_callback;	/* set if we want to do callback next */
  extern int	doing_callback;	/* set if this is a callback */
  extern int	error_count;	/* # of times error() has been called */
  extern char	ppp_devnam[MAXPATHLEN];
  extern char     remote_number[MAXNAMELEN]; /* Remote telephone number, if avail. */
  extern int      ppp_session_number; /* Session number (eg PPPoE session) */
  extern int	fd_devnull;	/* fd open to /dev/null */
  
  extern int	listen_time;	/* time to listen first (ms) */
  extern bool	doing_multilink;
  extern bool	multilink_master;
  extern bool	bundle_eof;
  extern bool	bundle_terminating;
  
  extern struct notifier *pidchange;   /* for notifications of pid changing */
  extern struct notifier *phasechange; /* for notifications of phase changes */
  extern struct notifier *exitnotify;  /* for notification that we're exiting */
  extern struct notifier *sigreceived; /* notification of received signal */
  extern struct notifier *ip_up_notifier; /* IPCP has come up */
  extern struct notifier *ip_down_notifier; /* IPCP has gone down */
  extern struct notifier *auth_up_notifier; /* peer has authenticated */
  extern struct notifier *link_down_notifier; /* link has gone down */
  extern struct notifier *fork_notifier;	/* we are a new child process */
  
  /* Values for do_callback and doing_callback */
  #define CALLBACK_DIALIN		1	/* we are expecting the call back */
  #define CALLBACK_DIALOUT	2	/* we are dialling out to call back */
  
  /*
   * Variables set by command-line options.
   */
  
  extern int	debug;		/* Debug flag */
  extern int	kdebugflag;	/* Tell kernel to print debug messages */
  extern int	default_device;	/* Using /dev/tty or equivalent */
  extern char	devnam[MAXPATHLEN];	/* Device name */
  extern int	crtscts;	/* Use hardware flow control */
  extern bool	modem;		/* Use modem control lines */
  extern int	inspeed;	/* Input/Output speed requested */
  extern u_int32_t netmask;	/* IP netmask to set on interface */
  extern bool	lockflag;	/* Create lock file to lock the serial dev */
  extern bool	nodetach;	/* Don't detach from controlling tty */
  extern bool	updetach;	/* Detach from controlling tty when link up */
  extern char	*initializer;	/* Script to initialize physical link */
  extern char	*connect_script; /* Script to establish physical link */
  extern char	*disconnect_script; /* Script to disestablish physical link */
  extern char	*welcomer;	/* Script to welcome client after connection */
  extern char	*ptycommand;	/* Command to run on other side of pty */
  extern int	maxconnect;	/* Maximum connect time (seconds) */
  extern char	user[MAXNAMELEN];/* Our name for authenticating ourselves */
  extern char	passwd[MAXSECRETLEN];	/* Password for PAP or CHAP */
  extern bool	auth_required;	/* Peer is required to authenticate */
  extern bool	persist;	/* Reopen link after it goes down */
  extern bool	uselogin;	/* Use /etc/passwd for checking PAP */
  extern char	our_name[MAXNAMELEN];/* Our name for authentication purposes */
  extern char	remote_name[MAXNAMELEN]; /* Peer's name for authentication */
  extern bool	explicit_remote;/* remote_name specified with remotename opt */
  extern bool	demand;		/* Do dial-on-demand */
  extern char	*ipparam;	/* Extra parameter for ip up/down scripts */
  extern bool	cryptpap;	/* Others' PAP passwords are encrypted */
  extern int	idle_time_limit;/* Shut down link if idle for this long */
  extern int	holdoff;	/* Dead time before restarting */
  extern bool	holdoff_specified; /* true if user gave a holdoff value */
  extern bool	notty;		/* Stdin/out is not a tty */
  extern char	*pty_socket;	/* Socket to connect to pty */
  extern char	*record_file;	/* File to record chars sent/received */
  extern bool	sync_serial;	/* Device is synchronous serial device */
  extern int	maxfail;	/* Max # of unsuccessful connection attempts */
  extern char	linkname[MAXPATHLEN]; /* logical name for link */
  extern char   linkinterface[MAXSECRETLEN];    /* logical name for link interface*/
  extern bool	tune_kernel;	/* May alter kernel settings as necessary */
  extern int	connect_delay;	/* Time to delay after connect script */
  extern int	max_data_rate;	/* max bytes/sec through charshunt */
  extern int	req_unit;	/* interface unit number to use */
  extern bool	multilink;	/* enable multilink operation */
  extern bool	noendpoint;	/* don't send or accept endpt. discrim. */
  extern char	*bundle_name;	/* bundle name for multilink */
  extern bool	dump_options;	/* print out option values */
  extern bool	dryrun;		/* check everything, print options, exit */
  extern int	child_wait;	/* # seconds to wait for children at end */
  
  #ifdef MAXOCTETS
  extern unsigned int maxoctets;	     /* Maximum octetes per session (in bytes) */
  extern int       maxoctets_dir;      /* Direction :
  				      0 - in+out (default)
  				      1 - in 
  				      2 - out
  				      3 - max(in,out) */
  extern int       maxoctets_timeout;  /* Timeout for check of octets limit */
  #define PPP_OCTETS_DIRECTION_SUM        0
  #define PPP_OCTETS_DIRECTION_IN         1
  #define PPP_OCTETS_DIRECTION_OUT        2
  #define PPP_OCTETS_DIRECTION_MAXOVERAL  3
  /* same as previos, but little different on RADIUS side */
  #define PPP_OCTETS_DIRECTION_MAXSESSION 4	
  #endif
  
  #ifdef PPP_FILTER
  extern struct	bpf_program pass_filter;   /* Filter for pkts to pass */
  extern struct	bpf_program active_filter; /* Filter for link-active pkts */
  #endif
  
  #ifdef MSLANMAN
  extern bool	ms_lanman;	/* Use LanMan password instead of NT */
  				/* Has meaning only with MS-CHAP challenges */
  #endif
  
  /* Values for auth_pending, auth_done */
  #define PAP_WITHPEER	0x1
  #define PAP_PEER	0x2
  #define CHAP_WITHPEER	0x4
  #define CHAP_PEER	0x8
  #define EAP_WITHPEER	0x10
  #define EAP_PEER	0x20
  
  /* Values for auth_done only */
  #define CHAP_MD5_WITHPEER	0x40
  #define CHAP_MD5_PEER		0x80
  #define CHAP_MS_SHIFT		8	/* LSB position for MS auths */
  #define CHAP_MS_WITHPEER	0x100
  #define CHAP_MS_PEER		0x200
  #define CHAP_MS2_WITHPEER	0x400
  #define CHAP_MS2_PEER		0x800
  
  extern char *current_option;	/* the name of the option being parsed */
  extern int  privileged_option;	/* set iff the current option came from root */
  extern char *option_source;	/* string saying where the option came from */
  extern int  option_priority;	/* priority of current options */
  
  /*
   * Values for phase.
   */
  #define PHASE_DEAD		0
  #define PHASE_INITIALIZE	1
  #define PHASE_SERIALCONN	2
  #define PHASE_DORMANT		3
  #define PHASE_ESTABLISH		4
  #define PHASE_AUTHENTICATE	5
  #define PHASE_CALLBACK		6
  #define PHASE_NETWORK		7
  #define PHASE_RUNNING		8
  #define PHASE_TERMINATE		9
  #define PHASE_DISCONNECT	10
  #define PHASE_HOLDOFF		11
  #define PHASE_MASTER		12
  
  /*
   * The following struct gives the addresses of procedures to call
   * for a particular protocol.
   */
  struct protent {
      u_short protocol;		/* PPP protocol number */
      /* Initialization procedure */
      void (*init) __P((int unit));
      /* Process a received packet */
      void (*input) __P((int unit, u_char *pkt, int len));
      /* Process a received protocol-reject */
      void (*protrej) __P((int unit));
      /* Lower layer has come up */
      void (*lowerup) __P((int unit));
      /* Lower layer has gone down */
      void (*lowerdown) __P((int unit));
      /* Open the protocol */
      void (*open) __P((int unit));
      /* Close the protocol */
      void (*close) __P((int unit, char *reason));
      /* Print a packet in readable form */
      int  (*printpkt) __P((u_char *pkt, int len,
  			  void (*printer) __P((void *, char *, ...)),
  			  void *arg));
      /* Process a received data packet */
      void (*datainput) __P((int unit, u_char *pkt, int len));
      bool enabled_flag;		/* 0 iff protocol is disabled */
      char *name;			/* Text name of protocol */
      char *data_name;		/* Text name of corresponding data protocol */
      option_t *options;		/* List of command-line options */
      /* Check requested options, assign defaults */
      void (*check_options) __P((void));
      /* Configure interface for demand-dial */
      int  (*demand_conf) __P((int unit));
      /* Say whether to bring up link for this pkt */
      int  (*active_pkt) __P((u_char *pkt, int len));
  };
  
  /* Table of pointers to supported protocols */
  extern struct protent *protocols[];
  
  /*
   * This struct contains pointers to a set of procedures for
   * doing operations on a "channel".  A channel provides a way
   * to send and receive PPP packets - the canonical example is
   * a serial port device in PPP line discipline (or equivalently
   * with PPP STREAMS modules pushed onto it).
   */
  struct channel {
  	/* set of options for this channel */
  	option_t *options;
  	/* find and process a per-channel options file */
  	void (*process_extra_options) __P((void));
  	/* check all the options that have been given */
  	void (*check_options) __P((void));
  	/* get the channel ready to do PPP, return a file descriptor */
  	int  (*connect) __P((void));
  	/* we're finished with the channel */
  	void (*disconnect) __P((void));
  	/* put the channel into PPP `mode' */
  	int  (*establish_ppp) __P((int));
  	/* take the channel out of PPP `mode', restore loopback if demand */
  	void (*disestablish_ppp) __P((int));
  	/* set the transmit-side PPP parameters of the channel */
  	void (*send_config) __P((int, u_int32_t, int, int));
  	/* set the receive-side PPP parameters of the channel */
  	void (*recv_config) __P((int, u_int32_t, int, int));
  	/* cleanup on error or normal exit */
  	void (*cleanup) __P((void));
  	/* close the device, called in children after fork */
  	void (*close) __P((void));
  };
  
  extern struct channel *the_channel;
  
  /*
   * Prototypes.
   */
  
  /* Procedures exported from main.c. */
  void set_ifunit __P((int));	/* set stuff that depends on ifunit */
  void detach __P((void));	/* Detach from controlling tty */
  void die __P((int));		/* Cleanup and exit */
  void quit __P((void));		/* like die(1) */
  void novm __P((char *));	/* Say we ran out of memory, and die */
  void timeout __P((void (*func)(void *), void *arg, int s, int us));
  				/* Call func(arg) after s.us seconds */
  void untimeout __P((void (*func)(void *), void *arg));
  				/* Cancel call to func(arg) */
  void record_child __P((int, char *, void (*) (void *), void *));
  pid_t safe_fork __P((int, int, int));	/* Fork & close stuff in child */
  int  device_script __P((char *cmd, int in, int out, int dont_wait));
  				/* Run `cmd' with given stdin and stdout */
  pid_t run_program __P((char *prog, char **args, int must_exist,
  		       void (*done)(void *), void *arg));
  				/* Run program prog with args in child */
  void reopen_log __P((void));	/* (re)open the connection to syslog */
  void print_link_stats __P((void)); /* Print stats, if available */
  void reset_link_stats __P((int)); /* Reset (init) stats when link goes up */
  void update_link_stats __P((int)); /* Get stats at link termination */
  void script_setenv __P((char *, char *, int));	/* set script env var */
  void script_unsetenv __P((char *));		/* unset script env var */
  void new_phase __P((int));	/* signal start of new phase */
  void add_notifier __P((struct notifier **, notify_func, void *));
  void remove_notifier __P((struct notifier **, notify_func, void *));
  void notify __P((struct notifier *, int));
  int  ppp_send_config __P((int, int, u_int32_t, int, int));
  int  ppp_recv_config __P((int, int, u_int32_t, int, int));
  void remove_pidfiles __P((void));
  void lock_db __P((void));
  void unlock_db __P((void));
  
  /* Procedures exported from tty.c. */
  void tty_init __P((void));
  
  /* Procedures exported from utils.c. */
  void log_packet __P((u_char *, int, char *, int));
  				/* Format a packet and log it with syslog */
  void print_string __P((char *, int,  void (*) (void *, char *, ...),
  		void *));	/* Format a string for output */
  int slprintf __P((char *, int, char *, ...));		/* sprintf++ */
  int vslprintf __P((char *, int, char *, va_list));	/* vsprintf++ */
  #if !defined(ANDROID_CHANGES)
  size_t strlcpy __P((char *, const char *, size_t));	/* safe strcpy */
  size_t strlcat __P((char *, const char *, size_t));	/* safe strncpy */
  #endif
  void dbglog __P((char *, ...));	/* log a debug message */
  void info __P((char *, ...));	/* log an informational message */
  void notice __P((char *, ...));	/* log a notice-level message */
  void warn __P((char *, ...));	/* log a warning message */
  void error __P((char *, ...));	/* log an error message */
  void fatal __P((char *, ...));	/* log an error message and die(1) */
  void init_pr_log __P((char *, int));	/* initialize for using pr_log */
  void pr_log __P((void *, char *, ...));	/* printer fn, output to syslog */
  void end_pr_log __P((void));	/* finish up after using pr_log */
  void dump_packet __P((const char *, u_char *, int));
  				/* dump packet to debug log if interesting */
  ssize_t complete_read __P((int, void *, size_t));
  				/* read a complete buffer */
  
  /* Procedures exported from auth.c */
  void link_required __P((int));	  /* we are starting to use the link */
  void link_terminated __P((int));  /* we are finished with the link */
  void link_down __P((int));	  /* the LCP layer has left the Opened state */
  void upper_layers_down __P((int));/* take all NCPs down */
  void link_established __P((int)); /* the link is up; authenticate now */
  void start_networks __P((int));   /* start all the network control protos */
  void continue_networks __P((int)); /* start network [ip, etc] control protos */
  void np_up __P((int, int));	  /* a network protocol has come up */
  void np_down __P((int, int));	  /* a network protocol has gone down */
  void np_finished __P((int, int)); /* a network protocol no longer needs link */
  void auth_peer_fail __P((int, int));
  				/* peer failed to authenticate itself */
  void auth_peer_success __P((int, int, int, char *, int));
  				/* peer successfully authenticated itself */
  void auth_withpeer_fail __P((int, int));
  				/* we failed to authenticate ourselves */
  void auth_withpeer_success __P((int, int, int));
  				/* we successfully authenticated ourselves */
  void auth_check_options __P((void));
  				/* check authentication options supplied */
  void auth_reset __P((int));	/* check what secrets we have */
  int  check_passwd __P((int, char *, int, char *, int, char **));
  				/* Check peer-supplied username/password */
  int  get_secret __P((int, char *, char *, char *, int *, int));
  				/* get "secret" for chap */
  int  get_srp_secret __P((int unit, char *client, char *server, char *secret,
      int am_server));
  int  auth_ip_addr __P((int, u_int32_t));
  				/* check if IP address is authorized */
  int  auth_number __P((void));	/* check if remote number is authorized */
  int  bad_ip_adrs __P((u_int32_t));
  				/* check if IP address is unreasonable */
  
  /* Procedures exported from demand.c */
  void demand_conf __P((void));	/* config interface(s) for demand-dial */
  void demand_block __P((void));	/* set all NPs to queue up packets */
  void demand_unblock __P((void)); /* set all NPs to pass packets */
  void demand_discard __P((void)); /* set all NPs to discard packets */
  void demand_rexmit __P((int));	/* retransmit saved frames for an NP */
  int  loop_chars __P((unsigned char *, int)); /* process chars from loopback */
  int  loop_frame __P((unsigned char *, int)); /* should we bring link up? */
  
  /* Procedures exported from multilink.c */
  #ifdef HAVE_MULTILINK
  void mp_check_options __P((void)); /* Check multilink-related options */
  int  mp_join_bundle __P((void));  /* join our link to an appropriate bundle */
  void mp_exit_bundle __P((void));  /* have disconnected our link from bundle */
  void mp_bundle_terminated __P((void));
  char *epdisc_to_str __P((struct epdisc *)); /* string from endpoint discrim. */
  int  str_to_epdisc __P((struct epdisc *, char *)); /* endpt disc. from str */
  #else
  #define mp_bundle_terminated()	/* nothing */
  #define mp_exit_bundle()	/* nothing */
  #define doing_multilink		0
  #define multilink_master	0
  #endif
  
  /* Procedures exported from sys-*.c */
  void sys_init __P((void));	/* Do system-dependent initialization */
  void sys_cleanup __P((void));	/* Restore system state before exiting */
  int  sys_check_options __P((void)); /* Check options specified */
  void sys_close __P((void));	/* Clean up in a child before execing */
  int  ppp_available __P((void));	/* Test whether ppp kernel support exists */
  int  get_pty __P((int *, int *, char *, int));	/* Get pty master/slave */
  int  open_ppp_loopback __P((void)); /* Open loopback for demand-dialling */
  int  tty_establish_ppp __P((int));  /* Turn serial port into a ppp interface */
  void tty_disestablish_ppp __P((int)); /* Restore port to normal operation */
  void generic_disestablish_ppp __P((int dev_fd)); /* Restore device setting */
  int  generic_establish_ppp __P((int dev_fd)); /* Make a ppp interface */
  void make_new_bundle __P((int, int, int, int)); /* Create new bundle */
  int  bundle_attach __P((int));	/* Attach link to existing bundle */
  void cfg_bundle __P((int, int, int, int)); /* Configure existing bundle */
  void destroy_bundle __P((void)); /* Tell driver to destroy bundle */
  void clean_check __P((void));	/* Check if line was 8-bit clean */
  void set_up_tty __P((int, int)); /* Set up port's speed, parameters, etc. */
  void restore_tty __P((int));	/* Restore port's original parameters */
  void setdtr __P((int, int));	/* Raise or lower port's DTR line */
  void output __P((int, u_char *, int)); /* Output a PPP packet */
  void wait_input __P((struct timeval *));
  				/* Wait for input, with timeout */
  void add_fd __P((int));		/* Add fd to set to wait for */
  void remove_fd __P((int));	/* Remove fd from set to wait for */
  int  read_packet __P((u_char *)); /* Read PPP packet */
  int  get_loop_output __P((void)); /* Read pkts from loopback */
  void tty_send_config __P((int, u_int32_t, int, int));
  				/* Configure i/f transmit parameters */
  void tty_set_xaccm __P((ext_accm));
  				/* Set extended transmit ACCM */
  void tty_recv_config __P((int, u_int32_t, int, int));
  				/* Configure i/f receive parameters */
  int  ccp_test __P((int, u_char *, int, int));
  				/* Test support for compression scheme */
  void ccp_flags_set __P((int, int, int));
  				/* Set kernel CCP state */
  int  ccp_fatal_error __P((int)); /* Test for fatal decomp error in kernel */
  int  get_idle_time __P((int, struct ppp_idle *));
  				/* Find out how long link has been idle */
  int  get_ppp_stats __P((int, struct pppd_stats *));
  				/* Return link statistics */
  void netif_set_mtu __P((int, int)); /* Set PPP interface MTU */
  int  netif_get_mtu __P((int));      /* Get PPP interface MTU */
  int  sifvjcomp __P((int, int, int, int));
  				/* Configure VJ TCP header compression */
  int  sifup __P((int));		/* Configure i/f up for one protocol */
  int  sifnpmode __P((int u, int proto, enum NPmode mode));
  				/* Set mode for handling packets for proto */
  int  sifdown __P((int));	/* Configure i/f down for one protocol */
  int  sifaddr __P((int, u_int32_t, u_int32_t, u_int32_t));
  				/* Configure IPv4 addresses for i/f */
  int  cifaddr __P((int, u_int32_t, u_int32_t));
  				/* Reset i/f IP addresses */
  #ifdef INET6
  int  sif6addr __P((int, eui64_t, eui64_t));
  				/* Configure IPv6 addresses for i/f */
  int  cif6addr __P((int, eui64_t, eui64_t));
  				/* Remove an IPv6 address from i/f */
  #endif
  int  sifdefaultroute __P((int, u_int32_t, u_int32_t));
  				/* Create default route through i/f */
  int  cifdefaultroute __P((int, u_int32_t, u_int32_t));
  				/* Delete default route through i/f */
  int  sifproxyarp __P((int, u_int32_t));
  				/* Add proxy ARP entry for peer */
  int  cifproxyarp __P((int, u_int32_t));
  				/* Delete proxy ARP entry for peer */
  u_int32_t GetMask __P((u_int32_t)); /* Get appropriate netmask for address */
  int  lock __P((char *));	/* Create lock file for device */
  int  relock __P((int));		/* Rewrite lock file with new pid */
  void unlock __P((void));	/* Delete previously-created lock file */
  void logwtmp __P((const char *, const char *, const char *));
  				/* Write entry to wtmp file */
  int  get_host_seed __P((void));	/* Get host-dependent random number seed */
  int  have_route_to __P((u_int32_t)); /* Check if route to addr exists */
  #ifdef PPP_FILTER
  int  set_filters __P((struct bpf_program *pass, struct bpf_program *active));
  				/* Set filter programs in kernel */
  #endif
  #ifdef IPX_CHANGE
  int  sipxfaddr __P((int, unsigned long, unsigned char *));
  int  cipxfaddr __P((int));
  #endif
  int  get_if_hwaddr __P((u_char *addr, char *name));
  char *get_first_ethernet __P((void));
  
  /* Procedures exported from options.c */
  int setipaddr __P((char *, char **, int)); /* Set local/remote ip addresses */
  int  parse_args __P((int argc, char **argv));
  				/* Parse options from arguments given */
  int  options_from_file __P((char *filename, int must_exist, int check_prot,
  			    int privileged));
  				/* Parse options from an options file */
  int  options_from_user __P((void)); /* Parse options from user's .ppprc */
  int  options_for_tty __P((void)); /* Parse options from /etc/ppp/options.tty */
  int  options_from_list __P((struct wordlist *, int privileged));
  				/* Parse options from a wordlist */
  int  getword __P((FILE *f, char *word, int *newlinep, char *filename));
  				/* Read a word from a file */
  void option_error __P((char *fmt, ...));
  				/* Print an error message about an option */
  int int_option __P((char *, int *));
  				/* Simplified number_option for decimal ints */
  void add_options __P((option_t *)); /* Add extra options */
  void check_options __P((void));	/* check values after all options parsed */
  int  override_value __P((const char *, int, const char *));
  				/* override value if permitted by priority */
  void print_options __P((void (*) __P((void *, char *, ...)), void *));
  				/* print out values of all options */
  
  int parse_dotted_ip __P((char *, u_int32_t *));
  
  /*
   * Hooks to enable plugins to change various things.
   */
  extern int (*new_phase_hook) __P((int));
  extern int (*idle_time_hook) __P((struct ppp_idle *));
  extern int (*holdoff_hook) __P((void));
  extern int (*pap_check_hook) __P((void));
  extern int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
  				 struct wordlist **paddrs,
  				 struct wordlist **popts));
  extern void (*pap_logout_hook) __P((void));
  extern int (*pap_passwd_hook) __P((char *user, char *passwd));
  extern int (*allowed_address_hook) __P((u_int32_t addr));
  extern void (*ip_up_hook) __P((void));
  extern void (*ip_down_hook) __P((void));
  extern void (*ip_choose_hook) __P((u_int32_t *));
  
  extern int (*chap_check_hook) __P((void));
  extern int (*chap_passwd_hook) __P((char *user, char *passwd));
  
  /* Let a plugin snoop sent and received packets.  Useful for L2TP */
  extern void (*snoop_recv_hook) __P((unsigned char *p, int len));
  extern void (*snoop_send_hook) __P((unsigned char *p, int len));
  
  /*
   * Inline versions of get/put char/short/long.
   * Pointer is advanced; we assume that both arguments
   * are lvalues and will already be in registers.
   * cp MUST be u_char *.
   */
  #define GETCHAR(c, cp) { \
  	(c) = *(cp)++; \
  }
  #define PUTCHAR(c, cp) { \
  	*(cp)++ = (u_char) (c); \
  }
  
  
  #define GETSHORT(s, cp) { \
  	(s) = *(cp)++ << 8; \
  	(s) |= *(cp)++; \
  }
  #define PUTSHORT(s, cp) { \
  	*(cp)++ = (u_char) ((s) >> 8); \
  	*(cp)++ = (u_char) (s); \
  }
  
  #define GETLONG(l, cp) { \
  	(l) = *(cp)++ << 8; \
  	(l) |= *(cp)++; (l) <<= 8; \
  	(l) |= *(cp)++; (l) <<= 8; \
  	(l) |= *(cp)++; \
  }
  #define PUTLONG(l, cp) { \
  	*(cp)++ = (u_char) ((l) >> 24); \
  	*(cp)++ = (u_char) ((l) >> 16); \
  	*(cp)++ = (u_char) ((l) >> 8); \
  	*(cp)++ = (u_char) (l); \
  }
  
  #define INCPTR(n, cp)	((cp) += (n))
  #define DECPTR(n, cp)	((cp) -= (n))
  
  /*
   * System dependent definitions for user-level 4.3BSD UNIX implementation.
   */
  
  #define TIMEOUT(r, f, t)	timeout((r), (f), (t), 0)
  #define UNTIMEOUT(r, f)		untimeout((r), (f))
  
  #define BCOPY(s, d, l)		memcpy(d, s, l)
  #define BZERO(s, n)		memset(s, 0, n)
  #define	BCMP(s1, s2, l)		memcmp(s1, s2, l)
  
  #define PRINTMSG(m, l)		{ info("Remote message: %0.*v", l, m); }
  
  /*
   * MAKEHEADER - Add Header fields to a packet.
   */
  #define MAKEHEADER(p, t) { \
      PUTCHAR(PPP_ALLSTATIONS, p); \
      PUTCHAR(PPP_UI, p); \
      PUTSHORT(t, p); }
  
  /*
   * Exit status values.
   */
  #define EXIT_OK			0
  #define EXIT_FATAL_ERROR	1
  #define EXIT_OPTION_ERROR	2
  #define EXIT_NOT_ROOT		3
  #define EXIT_NO_KERNEL_SUPPORT	4
  #define EXIT_USER_REQUEST	5
  #define EXIT_LOCK_FAILED	6
  #define EXIT_OPEN_FAILED	7
  #define EXIT_CONNECT_FAILED	8
  #define EXIT_PTYCMD_FAILED	9
  #define EXIT_NEGOTIATION_FAILED	10
  #define EXIT_PEER_AUTH_FAILED	11
  #define EXIT_IDLE_TIMEOUT	12
  #define EXIT_CONNECT_TIME	13
  #define EXIT_CALLBACK		14
  #define EXIT_PEER_DEAD		15
  #define EXIT_HANGUP		16
  #define EXIT_LOOPBACK		17
  #define EXIT_INIT_FAILED	18
  #define EXIT_AUTH_TOPEER_FAILED	19
  #ifdef MAXOCTETS
  #define EXIT_TRAFFIC_LIMIT	20
  #endif
  #define EXIT_CNID_AUTH_FAILED	21
  
  /*
   * Debug macros.  Slightly useful for finding bugs in pppd, not particularly
   * useful for finding out why your connection isn't being established.
   */
  #ifdef DEBUGALL
  #define DEBUGMAIN	1
  #define DEBUGFSM	1
  #define DEBUGLCP	1
  #define DEBUGIPCP	1
  #define DEBUGIPV6CP	1
  #define DEBUGUPAP	1
  #define DEBUGCHAP	1
  #endif
  
  #ifndef LOG_PPP			/* we use LOG_LOCAL2 for syslog by default */
  #if defined(DEBUGMAIN) || defined(DEBUGFSM) || defined(DEBUGSYS) \
    || defined(DEBUGLCP) || defined(DEBUGIPCP) || defined(DEBUGUPAP) \
    || defined(DEBUGCHAP) || defined(DEBUG) || defined(DEBUGIPV6CP)
  #define LOG_PPP LOG_LOCAL2
  #else
  #define LOG_PPP LOG_DAEMON
  #endif
  #endif /* LOG_PPP */
  
  #ifdef DEBUGMAIN
  #define MAINDEBUG(x)	if (debug) dbglog x
  #else
  #define MAINDEBUG(x)
  #endif
  
  #ifdef DEBUGSYS
  #define SYSDEBUG(x)	if (debug) dbglog x
  #else
  #define SYSDEBUG(x)
  #endif
  
  #ifdef DEBUGFSM
  #define FSMDEBUG(x)	if (debug) dbglog x
  #else
  #define FSMDEBUG(x)
  #endif
  
  #ifdef DEBUGLCP
  #define LCPDEBUG(x)	if (debug) dbglog x
  #else
  #define LCPDEBUG(x)
  #endif
  
  #ifdef DEBUGIPCP
  #define IPCPDEBUG(x)	if (debug) dbglog x
  #else
  #define IPCPDEBUG(x)
  #endif
  
  #ifdef DEBUGIPV6CP
  #define IPV6CPDEBUG(x)  if (debug) dbglog x
  #else
  #define IPV6CPDEBUG(x)
  #endif
  
  #ifdef DEBUGUPAP
  #define UPAPDEBUG(x)	if (debug) dbglog x
  #else
  #define UPAPDEBUG(x)
  #endif
  
  #ifdef DEBUGCHAP
  #define CHAPDEBUG(x)	if (debug) dbglog x
  #else
  #define CHAPDEBUG(x)
  #endif
  
  #ifdef DEBUGIPXCP
  #define IPXCPDEBUG(x)	if (debug) dbglog x
  #else
  #define IPXCPDEBUG(x)
  #endif
  
  #ifndef SIGTYPE
  #if defined(sun) || defined(SYSV) || defined(POSIX_SOURCE)
  #define SIGTYPE void
  #else
  #define SIGTYPE int
  #endif /* defined(sun) || defined(SYSV) || defined(POSIX_SOURCE) */
  #endif /* SIGTYPE */
  
  #ifndef MIN
  #define MIN(a, b)	((a) < (b)? (a): (b))
  #endif
  #ifndef MAX
  #define MAX(a, b)	((a) > (b)? (a): (b))
  #endif
  
  #ifndef offsetof
  #define offsetof(type, member) ((size_t) &((type *)0)->member)
  #endif
  
  #endif /* __PPP_H__ */
  