/*	$OpenBSD: tcpd.h,v 1.16 2012/12/05 23:20:06 deraadt Exp $	*/

/*
 * Copyright (c) 1997, Jason Downs.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
 /*
  * @(#) tcpd.h 1.5 96/03/19 16:22:24
  * 
  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
  */

#ifndef _TCPD_H_
#define _TCPD_H_

/* Structure to describe one communications endpoint. */

#define STRING_LENGTH	256		/* 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 *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)(int);			/* datagram sink function or 0 */
    void  (*hostname)(struct host_info *); /* address to printable hostname */
    void  (*hostaddr)(struct host_info *); /* address to printable address */
    void  (*cleanup)(void);		/* 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 */

__BEGIN_DECLS
extern char unknown[];
extern char paranoid[];
__END_DECLS

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

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

/* Global functions. */
#ifdef __cplusplus
extern "C" {
#endif

#define fromhost sock_host		/* no TLI support needed */

__BEGIN_DECLS
extern int hosts_access(struct request_info *);
extern int hosts_ctl(char *, char *, char *, char *);
extern void shell_cmd(char *);
extern char *percent_m(char *, char *);
extern char *percent_x(char *, int, char *, struct request_info *);
extern void rfc931(struct sockaddr *, struct sockaddr *, char *);
extern int rfc1413(struct sockaddr *, struct sockaddr *, char *, size_t, int);
extern void clean_exit(struct request_info *);
extern void refuse(struct request_info *);
#ifdef _STDIO_H_
extern char *xgets(char *, int, FILE *);
#endif	/* _STDIO_H_ */
extern char *split_at(char *, int);
extern int dot_quad_addr_new(char *, in_addr_t *);
extern in_addr_t dot_quad_addr(char *);

#ifdef __cplusplus
}
#endif

/* 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.
  */

extern struct request_info *request_init(struct request_info *, ...);
extern struct request_info *request_set(struct request_info *, ...);

#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(struct request_info *);
extern char *eval_hostname(struct host_info *);
extern char *eval_hostaddr(struct host_info *);
extern char *eval_hostinfo(struct host_info *);
extern char *eval_client(struct request_info *);
extern char *eval_server(struct request_info *);
#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(struct host_info *);
extern void sock_hostaddr(struct host_info *);
#define sock_methods(r) \
	{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }

 /*
  * 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>.
  */

extern void tcpd_warn(char *, ...)
    __attribute__((__format__(__printf__, 1, 2)));
extern void tcpd_jump(char *, ...)
    __attribute__((__format__(__printf__, 1, 2)));
__END_DECLS

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

__BEGIN_DECLS
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(char *, struct request_info *);
extern int dry_run;			/* verification flag */
__END_DECLS

#endif	/* _TCPD_H_ */