/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */

/*

 * Copyright (C) 2004 by the Massachusetts Institute of Technology,

 * Cambridge, MA, USA.  All Rights Reserved.

 *

 * This software is being provided to you, the LICENSEE, by the

 * Massachusetts Institute of Technology (M.I.T.) under the following

 * license.  By obtaining, using and/or copying this software, you agree

 * that you have read, understood, and will comply with these terms and

 * conditions:

 *

 * Export of this software from the United States of America may

 * require a specific license from the United States Government.

 * It is the responsibility of any person or organization contemplating

 * export to obtain such a license before exporting.

 *

 * WITHIN THAT CONSTRAINT, permission to use, copy, modify and distribute

 * this software and its documentation for any purpose and without fee or

 * royalty is hereby granted, provided that you agree to comply with the

 * following copyright notice and statements, including the disclaimer, and

 * that the same appear on ALL copies of the software and documentation,

 * including modifications that you make for internal use or for

 * distribution:

 *

 * THIS SOFTWARE IS PROVIDED "AS IS", AND M.I.T. MAKES NO REPRESENTATIONS

 * OR WARRANTIES, EXPRESS OR IMPLIED.  By way of example, but not

 * limitation, M.I.T. MAKES NO REPRESENTATIONS OR WARRANTIES OF

 * MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF

 * THE LICENSED SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY

 * PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.

 *

 * The name of the Massachusetts Institute of Technology or M.I.T. may NOT

 * be used in advertising or publicity pertaining to distribution of the

 * software.  Title to copyright in this software and any associated

 * documentation shall at all times remain with M.I.T., and USER agrees to

 * preserve same.

 *

 * Furthermore if you modify this software you must label

 * your software as modified software and not distribute it in such a

 * fashion that it might be confused with the original M.I.T. software.

 */

/*

 * Approach overview:

 *

 * If a system version is available but buggy, save handles to it,

 * redefine the names to refer to static functions defined here, and

 * in those functions, call the system versions and fix up the

 * returned data.  Use the native data structures and flag values.

 *

 * If no system version exists, use gethostby* and fake it.  Define

 * the data structures and flag values locally.

 *

 *

 * On macOS, getaddrinfo results aren't cached (though gethostbyname

 * results are), so we need to build a cache here.  Now things are

 * getting really messy.  Because the cache is in use, we use

 * getservbyname, and throw away thread safety.  (Not that the cache

 * is thread safe, but when we get locking support, that'll be dealt

 * with.)  This code needs tearing down and rebuilding, soon.

 *

 *

 * Note that recent Windows developers' code has an interesting hack:

 * When you include the right header files, with the right set of

 * macros indicating system versions, you'll get an inline function

 * that looks for getaddrinfo (or whatever) in the system library, and

 * calls it if it's there.  If it's not there, it fakes it with

 * gethostby* calls.

 *

 * We're taking a simpler approach: A system provides these routines or

 * it does not.

 *

 * Someday, we may want to take into account different versions (say,

 * different revs of GNU libc) where some are broken in one way, and

 * some work or are broken in another way.  Cross that bridge when we

 * come to it.

 */

/* To do, maybe:

 *

 * + For AIX 4.3.3, using the RFC 2133 definition: Implement

 *   AI_NUMERICHOST.  It's not defined in the header file.

 *

 *   For certain (old?) versions of GNU libc, AI_NUMERICHOST is

 *   defined but not implemented.

 *

 * + Use gethostbyname2, inet_aton and other IPv6 or thread-safe

 *   functions if available.  But, see

 *   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=135182 for one

 *   gethostbyname2 problem on Linux.  And besides, if a platform is

 *   supporting IPv6 at all, they really should be doing getaddrinfo

 *   by now.

 *

 * + inet_ntop, inet_pton

 *

 * + Conditionally export/import the function definitions, so a

 *   library can have a single copy instead of multiple.

 *

 * + Upgrade host requirements to include working implementations of

 *   these functions, and throw all this away.  Pleeease?  :-)

 */

#include "k5-platform.h"

#include "k5-thread.h"

#include "port-sockets.h"

#include "socket-utils.h"

#include "fake-addrinfo.h"

#if defined (__APPLE__) && defined (__MACH__) && 0

#define FAI_CACHE

#endif

struct face {

    struct in_addr *addrs4;

    struct in6_addr *addrs6;

    unsigned int naddrs4, naddrs6;

    time_t expiration;

    char *canonname, *name;

    struct face *next;

};

/* fake addrinfo cache */

struct fac {

    k5_mutex_t lock;

    struct face *data;

};

extern struct fac krb5int_fac;

extern int krb5int_init_fac (void);

extern void krb5int_fini_fac (void);