/*
 * Copyright 2014 Sachidananda Urs <sacchi@gmail.com>
 * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * @(#) 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

/*
 * HAVE_IPV6 is traditionally configured at tcp_wrappers build time but for
 * Solaris it must always be defined to keep the library interface binary
 * compatible.
 */
#define HAVE_IPV6

/* Structure to describe one communications endpoint. */

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

#include <sys/socket.h>
#include <netinet/in.h>

typedef struct sockaddr_gen {
    union {
        struct sockaddr _sg_sa;
        struct sockaddr_in      _sg_sin;
#ifdef HAVE_IPV6
        struct sockaddr_in6     _sg_sin6;
#endif
        } sg_addr;
} sockaddr_gen;

typedef union gen_addr {
    struct in_addr      ga_in;
#ifdef HAVE_IPV6
    struct in6_addr     ga_in6;
#endif
} gen_addr;

extern void sockgen_simplify();

#define sg_sa           sg_addr._sg_sa
#define sg_sin          sg_addr._sg_sin
#define sg_sin6         sg_addr._sg_sin6
#define sg_family       sg_sa.sa_family
#ifdef HAVE_IPV6
#define SGADDRSZ(sag)           ((sag)->sg_family == AF_INET6 ? \
                                    sizeof (struct in6_addr) : \
                                    sizeof (struct in_addr))
#define SGSOCKADDRSZ(sag)       ((sag)->sg_family == AF_INET6 ? \
                                    sizeof (struct sockaddr_in6) : \
                                    sizeof (struct sockaddr_in))
#define SGPORT(sag)             (*((sag)->sg_family == AF_INET6 ? \
                                    &(sag)->sg_sin6.sin6_port : \
                                    &(sag)->sg_sin.sin_port))
#define SGADDRP(sag)            (((sag)->sg_family == AF_INET6 ? \
                                    (char *)&(sag)->sg_sin6.sin6_addr : \
                                    (char *)&(sag)->sg_sin.sin_addr))
#define SGFAM(sag)              ((sag)->sg_family == AF_INET6 ? \
                                    AF_INET6 : AF_INET)

#define SG_IS_UNSPECIFIED(sag) \
                ((sag)->sg_family == AF_INET6 ? \
                        IN6_IS_ADDR_UNSPECIFIED(&(sag)->sg_sin6.sin6_addr) : \
                        (sag)->sg_sin.sin_addr.s_addr == 0)

#define VALID_ADDRTYPE(t)       ((t) == AF_INET || (t) == AF_INET6)

#ifndef IPV6_ABITS
#define IPV6_ABITS 128                  /* Size of IPV6 address in bits */
#endif

#else /* HAVE_IPV6 */

#define SGADDRSZ(sag)           sizeof (struct in_addr)
#define SGSOCKADDRSZ(sag)       sizeof (struct sockaddr_in)
#define SGPORT(sag)             ((sag)->sg_sin.sin_port)
#define SGADDRP(sag)            ((char *)&(sag)->sg_sin.sin_addr)
#define SGFAM(sag)              AF_INET
#define SG_IS_UNSPECIFIED(sag)  ((sag)->sg_sin.sin_addr.s_addr == 0)

#define VALID_ADDRTYPE(t)       ((t) == AF_INET)

#endif /* HAVE_IPV6 */

struct host_info {
    char    name[STRING_LENGTH];        /* access via eval_hostname(host) */
    char    addr[STRING_LENGTH];        /* access via eval_hostaddr(host) */
    struct sockaddr_gen *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))

#ifdef HAVE_IPV6
#define NOT_INADDR(s) (strchr(s, ':') == 0 && s[strspn(s, "0123456789./")] != 0)
#else
#define NOT_INADDR(s) (s[strspn(s, "0123456789./")] != 0)
#endif

/* 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_ctl();                 /* wrapper around request_init() */
extern int hosts_access();              /* 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() */
extern int numeric_addr();              /* IP4/IP6 inet_addr (restricted) */
extern struct hostent *tcpd_gethostbyname();
                                        /* IP4/IP6 gethostbyname */
#ifdef HAVE_IPV6
extern char *skip_ipv6_addrs();         /* skip over colons in IPv6 addrs */
#else
#define skip_ipv6_addrs(x)      x
#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.
 */

#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();             /* 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();                /* look up endpoint addresses */
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

#endif /* _TCPD_H */