 /*
  * @(#) tcpd.h 1.5 96/03/19 16:22:24
  *
  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
  */

#ifdef __cplusplus
extern "C" {
#endif

/* Structure to describe one communications endpoint. */

#define STRING_LENGTH   128             /* hosts, users, processes */

struct host_info {
    char    name[STRING_LENGTH];        /* access via eval_hostname(host) */
    char    addr[STRING_LENGTH];        /* access via eval_hostaddr(host) */
    struct sockaddr_in *sin;            /* socket address or 0 */
    struct t_unitdata *unit;            /* TLI transport address or 0 */
    struct request_info *request;       /* for shared information */
};

/* Structure to describe what we know about a service request. */

struct request_info {
    int     fd;                         /* socket handle */
    char    user[STRING_LENGTH];        /* access via eval_user(request) */
    char    daemon[STRING_LENGTH];      /* access via eval_daemon(request) */
    char    pid[10];                    /* access via eval_pid(request) */
    struct host_info client[1];         /* client endpoint info */
    struct host_info server[1];         /* server endpoint info */
    void  (*sink) ();                   /* datagram sink function or 0 */
    void  (*hostname) ();               /* address to printable hostname */
    void  (*hostaddr) ();               /* address to printable address */
    void  (*cleanup) ();                /* cleanup function or 0 */
    struct netconfig *config;           /* netdir handle */
};

/* Common string operations. Less clutter should be more readable. */

#define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }

#define STRN_EQ(x,y,l)  (strncasecmp((x),(y),(l)) == 0)
#define STRN_NE(x,y,l)  (strncasecmp((x),(y),(l)) != 0)
#define STR_EQ(x,y)     (strcasecmp((x),(y)) == 0)
#define STR_NE(x,y)     (strcasecmp((x),(y)) != 0)

 /*
  * Initially, all above strings have the empty value. Information that
  * cannot be determined at runtime is set to "unknown", so that we can
  * distinguish between `unavailable' and `not yet looked up'. A hostname
  * that we do not believe in is set to "paranoid".
  */

#define STRING_UNKNOWN  "unknown"       /* lookup failed */
#define STRING_PARANOID "paranoid"      /* hostname conflict */

extern char unknown[];
extern char paranoid[];

#define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))

#define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)

/* Global functions. */

#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void fromhost();                 /* get/validate client host info */
#else
#define fromhost sock_host              /* no TLI support needed */
#endif

extern int hosts_access(struct request_info *); /* access control */
extern void shell_cmd();                /* execute shell command */
extern char *percent_x();               /* do %<char> expansion */
extern void rfc931();                   /* client name from RFC 931 daemon */
extern void clean_exit();               /* clean up and exit */
extern void refuse();                   /* clean up and exit */
extern char *xgets();                   /* fgets() on steroids */
extern char *split_at();                /* strchr() and split */
extern unsigned long dot_quad_addr();   /* restricted inet_addr() */

/* Global variables. */

extern int allow_severity;              /* for connection logging */
extern int deny_severity;               /* for connection logging */
extern char *hosts_allow_table;         /* for verification mode redirection */
extern char *hosts_deny_table;          /* for verification mode redirection */
extern int hosts_access_verbose;        /* for verbose matching mode */
extern int rfc931_timeout;              /* user lookup timeout */
extern int resident;                    /* > 0 if resident process */

 /*
  * Routines for controlled initialization and update of request structure
  * attributes. Each attribute has its own key.
  */

#ifdef __STDC__
extern struct request_info *request_init(struct request_info *,...);
extern struct request_info *request_set(struct request_info *,...);
#else
extern struct request_info *request_init();     /* initialize request */
extern struct request_info *request_set();      /* update request structure */
#endif

#define RQ_FILE         1               /* file descriptor */
#define RQ_DAEMON       2               /* server process (argv[0]) */
#define RQ_USER         3               /* client user name */
#define RQ_CLIENT_NAME  4               /* client host name */
#define RQ_CLIENT_ADDR  5               /* client host address */
#define RQ_CLIENT_SIN   6               /* client endpoint (internal) */
#define RQ_SERVER_NAME  7               /* server host name */
#define RQ_SERVER_ADDR  8               /* server host address */
#define RQ_SERVER_SIN   9               /* server endpoint (internal) */

 /*
  * Routines for delayed evaluation of request attributes. Each attribute
  * type has its own access method. The trivial ones are implemented by
  * macros. The other ones are wrappers around the transport-specific host
  * name, address, and client user lookup methods. The request_info and
  * host_info structures serve as caches for the lookup results.
  */

extern char *eval_user();               /* client user */
extern char *eval_hostname();           /* printable hostname */
extern char *eval_hostaddr();           /* printable host address */
extern char *eval_hostinfo();           /* host name or address */
extern char *eval_client(struct request_info *); /* whatever is available */
extern char *eval_server();             /* whatever is available */
#define eval_daemon(r)  ((r)->daemon)   /* daemon process name */
#define eval_pid(r)     ((r)->pid)      /* process id */

/* Socket-specific methods, including DNS hostname lookups. */

extern void sock_host(struct request_info *);
extern void sock_hostname();            /* translate address to hostname */
extern void sock_hostaddr();            /* address to printable address */
#define sock_methods(r) \
        { (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }

/* The System V Transport-Level Interface (TLI) interface. */

#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void tli_host();                 /* look up endpoint addresses etc. */
#endif

 /*
  * Problem reporting interface. Additional file/line context is reported
  * when available. The jump buffer (tcpd_buf) is not declared here, or
  * everyone would have to include <setjmp.h>.
  */

#ifdef __STDC__
extern void tcpd_warn(char *, ...);     /* report problem and proceed */
extern void tcpd_jump(char *, ...);     /* report problem and jump */
#else
extern void tcpd_warn();
extern void tcpd_jump();
#endif

struct tcpd_context {
    char   *file;                       /* current file */
    int     line;                       /* current line */
};
extern struct tcpd_context tcpd_context;

 /*
  * While processing access control rules, error conditions are handled by
  * jumping back into the hosts_access() routine. This is cleaner than
  * checking the return value of each and every silly little function. The
  * (-1) returns are here because zero is already taken by longjmp().
  */

#define AC_PERMIT       1               /* permit access */
#define AC_DENY         (-1)            /* deny_access */
#define AC_ERROR        AC_DENY         /* XXX */

 /*
  * In verification mode an option function should just say what it would do,
  * instead of really doing it. An option function that would not return
  * should clear the dry_run flag to inform the caller of this unusual
  * behavior.
  */

extern void process_options();          /* execute options */
extern int dry_run;                     /* verification flag */

/* Bug workarounds. */

#ifdef INET_ADDR_BUG                    /* inet_addr() returns struct */
#define inet_addr fix_inet_addr
extern long fix_inet_addr();
#endif

#ifdef BROKEN_FGETS                     /* partial reads from sockets */
#define fgets fix_fgets
extern char *fix_fgets();
#endif

#ifdef RECVFROM_BUG                     /* no address family info */
#define recvfrom fix_recvfrom
extern int fix_recvfrom();
#endif

#ifdef GETPEERNAME_BUG                  /* claims success with UDP */
#define getpeername fix_getpeername
extern int fix_getpeername();
#endif

#ifdef SOLARIS_24_GETHOSTBYNAME_BUG     /* lists addresses as aliases */
#define gethostbyname fix_gethostbyname
extern struct hostent *fix_gethostbyname();
#endif

#ifdef USE_STRSEP                       /* libc calls strtok() */
#define strtok  fix_strtok
extern char *fix_strtok();
#endif

#ifdef LIBC_CALLS_STRTOK                /* libc calls strtok() */
#define strtok  my_strtok
extern char *my_strtok();
#endif

#ifdef __cplusplus
}
#endif
