/*

 * Copying and distribution of this file, with or without modification,

 * are permitted in any medium without royalty provided the copyright

 * notice and this notice are preserved.  This file is offered as-is,

 * without any warranty.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "zlib.h"

#if defined(GNUTLS_ZLIB_ENABLE_DLOPEN) && GNUTLS_ZLIB_ENABLE_DLOPEN

#include <assert.h>

#include <dlfcn.h>

#include <errno.h>

#include <stdlib.h>

/* If Z_LIBRARY_SONAME_UNUSED is defined, dlopen handle can be automatically

 * set; otherwise, the caller needs to call

 * gnutls_zlib_ensure_library with soname determined at run time.

 */

#ifdef Z_LIBRARY_SONAME_UNUSED

static void

ensure_library (void)

{

  if (gnutls_zlib_ensure_library (Z_LIBRARY_SONAME_UNUSED, RTLD_LAZY | RTLD_LOCAL) < 0)

    abort ();

}

#if defined(GNUTLS_ZLIB_ENABLE_PTHREAD) && GNUTLS_ZLIB_ENABLE_PTHREAD

#include <pthread.h>

static pthread_once_t dlopen_once = PTHREAD_ONCE_INIT;

#define ENSURE_LIBRARY pthread_once(&dlopen_once, ensure_library)

#else /* GNUTLS_ZLIB_ENABLE_PTHREAD */

#define ENSURE_LIBRARY do {     \

    if (!gnutls_zlib_dlhandle) \

      ensure_library();       \

  } while (0)

#endif /* !GNUTLS_ZLIB_ENABLE_PTHREAD */

#else /* Z_LIBRARY_SONAME_UNUSED */

#define ENSURE_LIBRARY do {} while (0)

#endif /* !Z_LIBRARY_SONAME_UNUSED */

static void *gnutls_zlib_dlhandle;

/* Define redirection symbols */

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-macros"

#if (2 <= __GNUC__ || (4 <= __clang_major__))

#define FUNC(ret, name, args, cargs)      \

  static __typeof__(name)(*gnutls_zlib_sym_##name);

#else

#define FUNC(ret, name, args, cargs)    \

  static ret(*gnutls_zlib_sym_##name)args;

#endif

#define VOID_FUNC FUNC

#include "zlibfuncs.h"

#undef VOID_FUNC

#undef FUNC

#pragma GCC diagnostic pop

/* Define redirection wrapper functions */

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-macros"

#define FUNC(ret, name, args, cargs)        \

ret gnutls_zlib_func_##name args           \

{             \

  ENSURE_LIBRARY;         \

  assert (gnutls_zlib_sym_##name);      \

  return gnutls_zlib_sym_##name cargs;     \

}

Unexecuted instantiation: gnutls_zlib_func_compress

Unexecuted instantiation: gnutls_zlib_func_compressBound

Unexecuted instantiation: gnutls_zlib_func_uncompress

#define VOID_FUNC(ret, name, args, cargs)   \

ret gnutls_zlib_func_##name args           \

{             \

  ENSURE_LIBRARY;         \

  assert (gnutls_zlib_sym_##name);      \

  gnutls_zlib_sym_##name cargs;       \

}

#include "zlibfuncs.h"

#undef VOID_FUNC

#undef FUNC

#pragma GCC diagnostic pop

static int

ensure_symbol (const char *name, void **symp)

{

  if (!*symp)

    {

      void *sym = dlsym (gnutls_zlib_dlhandle, name);

      if (!sym)

  return -EINVAL;

      *symp = sym;

    }

  return 0;

}

int

gnutls_zlib_ensure_library (const char *soname, int flags)

{

  int err;

  if (!gnutls_zlib_dlhandle)

    {

      gnutls_zlib_dlhandle = dlopen (soname, flags);

      if (!gnutls_zlib_dlhandle)

  return -EINVAL;

    }

#define ENSURE_SYMBOL(name)         \

  ensure_symbol(#name, (void **)&gnutls_zlib_sym_##name)

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-macros"

#define FUNC(ret, name, args, cargs)    \

  err = ENSURE_SYMBOL(name);     \

  if (err < 0)         \

    {           \

      dlclose (gnutls_zlib_dlhandle); \

      gnutls_zlib_dlhandle = NULL;    \

      return err;       \

    }

#define VOID_FUNC FUNC

#include "zlibfuncs.h"

#undef VOID_FUNC

#undef FUNC

#pragma GCC diagnostic pop

#undef ENSURE_SYMBOL

  return 0;

}

void

gnutls_zlib_unload_library (void)

{

  if (gnutls_zlib_dlhandle)

    {

      dlclose (gnutls_zlib_dlhandle);

      gnutls_zlib_dlhandle = NULL;

    }

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-macros"

#define FUNC(ret, name, args, cargs)    \

  gnutls_zlib_sym_##name = NULL;

#define VOID_FUNC FUNC

#include "zlibfuncs.h"

#undef VOID_FUNC

#undef FUNC

#pragma GCC diagnostic pop

}

unsigned

gnutls_zlib_is_usable (void)

{

  return gnutls_zlib_dlhandle != NULL;

}

#else /* GNUTLS_ZLIB_ENABLE_DLOPEN */

int

gnutls_zlib_ensure_library (const char *soname, int flags)

{

  (void) soname;

  (void) flags;

  return 0;

}

void

gnutls_zlib_unload_library (void)

{

}

unsigned

gnutls_zlib_is_usable (void)

{

  /* The library is linked at build time, thus always usable */

  return 1;

}

#endif /* !GNUTLS_ZLIB_ENABLE_DLOPEN */