1 files changed, 131 insertions, 0 deletions
diff --git a/src/util/support/cache-addrinfo.h b/src/util/support/cache-addrinfo.h
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+++ b/src/util/support/cache-addrinfo.h
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+/* -*- 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 Mac OS X, 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
+ *   http://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);