/* dso.h -*- mode:C; c-file-style: "eay" -*- */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 2000 The OpenSSL Project.  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.
 *
 * 3. All advertising materials mentioning features or use of this
 *   software must display the following acknowledgment:
 *   "This product includes software developed by the OpenSSL Project
 *   for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *   endorse or promote products derived from this software without
 *   prior written permission. For written permission, please contact
 *   licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *   nor may "OpenSSL" appear in their names without prior written
 *   permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *   acknowledgment:
 *   "This product includes software developed by the OpenSSL Project
 *   for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

module deimos.openssl.dso;

import deimos.openssl._d_util;

public import deimos.openssl.crypto;

extern (C):
nothrow:

/* These values are used as commands to DSO_ctrl() */
enum DSO_CTRL_GET_FLAGS = 1;
enum DSO_CTRL_SET_FLAGS = 2;
enum DSO_CTRL_OR_FLAGS = 3;

/* By default, DSO_load() will translate the provided filename into a form
 * typical for the platform (more specifically the DSO_METHOD) using the
 * dso_name_converter function of the method. Eg. win32 will transform "blah"
 * into "blah.dll", and dlfcn will transform it into "libblah.so". The
 * behaviour can be overriden by setting the name_converter callback in the DSO
 * object (using DSO_set_name_converter()). This callback could even utilise
 * the DSO_METHOD's converter too if it only wants to override behaviour for
 * one or two possible DSO methods. However, the following flag can be set in a
 * DSO to prevent* any* native name-translation at all - eg. if the caller has
 * prompted the user for a path to a driver library so the filename should be
 * interpreted as-is. */
enum DSO_FLAG_NO_NAME_TRANSLATION = 0x01;
/* An extra flag to give if only the extension should be added as
 * translation.  This is obviously only of importance on Unix and
 * other operating systems where the translation also may prefix
 * the name with something, like 'lib', and ignored everywhere else.
 * This flag is also ignored if DSO_FLAG_NO_NAME_TRANSLATION is used
 * at the same time. */
enum DSO_FLAG_NAME_TRANSLATION_EXT_ONLY = 0x02;

/* The following flag controls the translation of symbol names to upper
 * case.  This is currently only being implemented for OpenVMS.
 */
enum DSO_FLAG_UPCASE_SYMBOL = 0x10;

/* This flag loads the library with public symbols.
 * Meaning: The exported symbols of this library are public
 * to all libraries loaded after this library.
 * At the moment only implemented in unix.
 */
enum DSO_FLAG_GLOBAL_SYMBOLS = 0x20;


alias ExternC!(void function()) DSO_FUNC_TYPE;

alias dso_st DSO;

/* The function prototype used for method functions (or caller-provided
 * callbacks) that transform filenames. They are passed a DSO structure pointer
 * (or NULL if they are to be used independantly of a DSO object) and a
 * filename to transform. They should either return NULL (if there is an error
 * condition) or a newly allocated string containing the transformed form that
 * the caller will need to free with OPENSSL_free() when done. */
alias ExternC!(char*function(DSO*, const(char)*)) DSO_NAME_CONVERTER_FUNC;
/* The function prototype used for method functions (or caller-provided
 * callbacks) that merge two file specifications. They are passed a
 * DSO structure pointer (or NULL if they are to be used independantly of
 * a DSO object) and two file specifications to merge. They should
 * either return NULL (if there is an error condition) or a newly allocated
 * string containing the result of merging that the caller will need
 * to free with OPENSSL_free() when done.
 * Here, merging means that bits and pieces are taken from each of the
 * file specifications and added together in whatever fashion that is
 * sensible for the DSO method in question.  The only rule that really
 * applies is that if the two specification contain pieces of the same
 * type, the copy from the first string takes priority.  One could see
 * it as the first specification is the one given by the user and the
 * second being a bunch of defaults to add on if they're missing in the
 * first. */
alias ExternC!(char*function(DSO*, const(char)*, const(char)*)) DSO_MERGER_FUNC;

struct dso_meth_st
	{
	const(char)* name;
	/* Loads a shared library, NB: new DSO_METHODs must ensure that a
	 * successful load populates the loaded_filename field, and likewise a
	 * successful unload OPENSSL_frees and NULLs it out. */
	ExternC!(int function(DSO* dso)) dso_load;
	/* Unloads a shared library */
	ExternC!(int function(DSO* dso)) dso_unload;
	/* Binds a variable */
	ExternC!(void* function(DSO* dso, const(char)* symname)) dso_bind_var;
	/* Binds a function - assumes a return type of DSO_FUNC_TYPE.
	 * This should be cast to the real function prototype by the
	 * caller. Platforms that don't have compatible representations
	 * for different prototypes (this is possible within ANSI C)
	 * are highly unlikely to have shared libraries at all, let
	 * alone a DSO_METHOD implemented for them. */
	ExternC!(DSO_FUNC_TYPE function(DSO* dso, const(char)* symname)) dso_bind_func;

/* I don't think this would actually be used in any circumstances. */
version (none) {
	/* Unbinds a variable */
	ExternC!(int function(DSO* dso, char* symname, void* symptr)) dso_unbind_var;
	/* Unbinds a function */
	ExternC!(int function(DSO* dso, char* symname, DSO_FUNC_TYPE symptr)) dso_unbind_func;
}
	/* The generic (yuck) "ctrl()" function. NB: Negative return
	 * values (rather than zero) indicate errors. */
	ExternC!(c_long function(DSO* dso, int cmd, c_long larg, void* parg)) dso_ctrl;
	/* The default DSO_METHOD-specific function for converting filenames to
	 * a canonical native form. */
	DSO_NAME_CONVERTER_FUNC dso_name_converter;
	/* The default DSO_METHOD-specific function for converting filenames to
	 * a canonical native form. */
	DSO_MERGER_FUNC dso_merger;

	/* [De]Initialisation handlers. */
	ExternC!(int function(DSO* dso)) init_;
	ExternC!(int function(DSO* dso)) finish;

	/* Return pathname of the module containing location */
	ExternC!(int function(void* addr,char* path,int sz)) pathbyaddr;
	/* Perform global symbol lookup, i.e. among* all* modules */
	ExternC!(void* function(const(char)* symname)) globallookup;
	}
alias dso_meth_st DSO_METHOD;

/**********************************************************************/
/* The low-level handle type used to refer to a loaded shared library */

struct dso_st
	{
	DSO_METHOD* meth;
	/* Standard dlopen uses a (void*). Win32 uses a HANDLE. VMS
	 * doesn't use anything but will need to cache the filename
	 * for use in the dso_bind handler. All in all, let each
	 * method control its own destiny. "Handles" and such go in
	 * a STACK. */
	STACK_OF!() *meth_data;
	int references;
	int flags;
	/* For use by applications etc ... use this for your bits'n'pieces,
	 * don't touch meth_data! */
	CRYPTO_EX_DATA ex_data;
	/* If this callback function pointer is set to non-NULL, then it will
	 * be used in DSO_load() in place of meth->dso_name_converter. NB: This
	 * should normally set using DSO_set_name_converter(). */
	DSO_NAME_CONVERTER_FUNC name_converter;
	/* If this callback function pointer is set to non-NULL, then it will
	 * be used in DSO_load() in place of meth->dso_merger. NB: This
	 * should normally set using DSO_set_merger(). */
	DSO_MERGER_FUNC merger;
	/* This is populated with (a copy of) the platform-independant
	 * filename used for this DSO. */
	char* filename;
	/* This is populated with (a copy of) the translated filename by which
	 * the DSO was actually loaded. It is NULL iff the DSO is not currently
	 * loaded. NB: This is here because the filename translation process
	 * may involve a callback being invoked more than once not only to
	 * convert to a platform-specific form, but also to try different
	 * filenames in the process of trying to perform a load. As such, this
	 * variable can be used to indicate (a) whether this DSO structure
	 * corresponds to a loaded library or not, and (b) the filename with
	 * which it was actually loaded. */
	char* loaded_filename;
	};


DSO* 	DSO_new();
DSO* 	DSO_new_method(DSO_METHOD* method);
int	DSO_free(DSO* dso);
int	DSO_flags(DSO* dso);
int	DSO_up_ref(DSO* dso);
c_long	DSO_ctrl(DSO* dso, int cmd, c_long larg, void* parg);

/* This function sets the DSO's name_converter callback. If it is non-NULL,
 * then it will be used instead of the associated DSO_METHOD's function. If
 * oldcb is non-NULL then it is set to the function pointer value being
 * replaced. Return value is non-zero for success. */
int	DSO_set_name_converter(DSO* dso, DSO_NAME_CONVERTER_FUNC cb,
				DSO_NAME_CONVERTER_FUNC* oldcb);
/* These functions can be used to get/set the platform-independant filename
 * used for a DSO. NB: set will fail if the DSO is already loaded. */
const(char)* DSO_get_filename(DSO* dso);
int	DSO_set_filename(DSO* dso, const(char)* filename);
/* This function will invoke the DSO's name_converter callback to translate a
 * filename, or if the callback isn't set it will instead use the DSO_METHOD's
 * converter. If "filename" is NULL, the "filename" in the DSO itself will be
 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
 * simply duplicated. NB: This function is usually called from within a
 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so that
 * caller-created DSO_METHODs can do the same thing. A non-NULL return value
 * will need to be OPENSSL_free()'d. */
char* DSO_convert_filename(DSO* dso, const(char)* filename);
/* This function will invoke the DSO's merger callback to merge two file
 * specifications, or if the callback isn't set it will instead use the
 * DSO_METHOD's merger.  A non-NULL return value will need to be
 * OPENSSL_free()'d. */
char* DSO_merge(DSO* dso, const(char)* filespec1, const(char)* filespec2);
/* If the DSO is currently loaded, this returns the filename that it was loaded
 * under, otherwise it returns NULL. So it is also useful as a test as to
 * whether the DSO is currently loaded. NB: This will not necessarily return
 * the same value as DSO_convert_filename(dso, dso->filename), because the
 * DSO_METHOD's load function may have tried a variety of filenames (with
 * and/or without the aid of the converters) before settling on the one it
 * actually loaded. */
const(char)* DSO_get_loaded_filename(DSO* dso);

void	DSO_set_default_method(DSO_METHOD* meth);
DSO_METHOD* DSO_get_default_method();
DSO_METHOD* DSO_get_method(DSO* dso);
DSO_METHOD* DSO_set_method(DSO* dso, DSO_METHOD* meth);

/* The all-singing all-dancing load function, you normally pass NULL
 * for the first and third parameters. Use DSO_up and DSO_free for
 * subsequent reference count handling. Any flags passed in will be set
 * in the constructed DSO after its init() function but before the
 * load operation. If 'dso' is non-NULL, 'flags' is ignored. */
DSO* DSO_load(DSO* dso, const(char)* filename, DSO_METHOD* meth, int flags);

/* This function binds to a variable inside a shared library. */
void* DSO_bind_var(DSO* dso, const(char)* symname);

/* This function binds to a function inside a shared library. */
DSO_FUNC_TYPE DSO_bind_func(DSO* dso, const(char)* symname);

/* This method is the default, but will beg, borrow, or steal whatever
 * method should be the default on any particular platform (including
 * DSO_METH_null() if necessary). */
DSO_METHOD* DSO_METHOD_openssl();

/* This method is defined for all platforms - if a platform has no
 * DSO support then this will be the only method! */
DSO_METHOD* DSO_METHOD_null();

/* If DSO_DLFCN is defined, the standard dlfcn.h-style functions
 * (dlopen, dlclose, dlsym, etc) will be used and incorporated into
 * this method. If not, this method will return NULL. */
DSO_METHOD* DSO_METHOD_dlfcn();

/* If DSO_DL is defined, the standard dl.h-style functions (shl_load,
 * shl_unload, shl_findsym, etc) will be used and incorporated into
 * this method. If not, this method will return NULL. */
DSO_METHOD* DSO_METHOD_dl();

/* If WIN32 is defined, use DLLs. If not, return NULL. */
DSO_METHOD* DSO_METHOD_win32();

/* If VMS is defined, use shared images. If not, return NULL. */
DSO_METHOD* DSO_METHOD_vms();

/* This function writes null-terminated pathname of DSO module
 * containing 'addr' into 'sz' large caller-provided 'path' and
 * returns the number of characters [including trailing zero]
 * written to it. If 'sz' is 0 or negative, 'path' is ignored and
 * required amount of charachers [including trailing zero] to
 * accomodate pathname is returned. If 'addr' is NULL, then
 * pathname of cryptolib itself is returned. Negative or zero
 * return value denotes error.
 */
int DSO_pathbyaddr(void* addr,char* path,int sz);

/* This function should be used with caution! It looks up symbols in
 ** all* loaded modules and if module gets unloaded by somebody else
 * attempt to dereference the pointer is doomed to have fatal
 * consequences. Primary usage for this function is to probe* core*
 * system functionality, e.g. check if getnameinfo(3) is available
 * at run-time without bothering about OS-specific details such as
 * libc.so.versioning or where does it actually reside: in libc
 * itself or libsocket. */
void* DSO_global_lookup(const(char)* name);

/* If BeOS is defined, use shared images. If not, return NULL. */
DSO_METHOD* DSO_METHOD_beos();

/* BEGIN ERROR CODES */
/* The following lines are auto generated by the script mkerr.pl. Any changes
 * made after this point may be overwritten when the script is next run.
 */
void ERR_load_DSO_strings();

/* Error codes for the DSO functions. */

/* Function codes. */
enum DSO_F_BEOS_BIND_FUNC = 144;
enum DSO_F_BEOS_BIND_VAR = 145;
enum DSO_F_BEOS_LOAD = 146;
enum DSO_F_BEOS_NAME_CONVERTER = 147;
enum DSO_F_BEOS_UNLOAD = 148;
enum DSO_F_DLFCN_BIND_FUNC = 100;
enum DSO_F_DLFCN_BIND_VAR = 101;
enum DSO_F_DLFCN_LOAD = 102;
enum DSO_F_DLFCN_MERGER = 130;
enum DSO_F_DLFCN_NAME_CONVERTER = 123;
enum DSO_F_DLFCN_UNLOAD = 103;
enum DSO_F_DL_BIND_FUNC = 104;
enum DSO_F_DL_BIND_VAR = 105;
enum DSO_F_DL_LOAD = 106;
enum DSO_F_DL_MERGER = 131;
enum DSO_F_DL_NAME_CONVERTER = 124;
enum DSO_F_DL_UNLOAD = 107;
enum DSO_F_DSO_BIND_FUNC = 108;
enum DSO_F_DSO_BIND_VAR = 109;
enum DSO_F_DSO_CONVERT_FILENAME = 126;
enum DSO_F_DSO_CTRL = 110;
enum DSO_F_DSO_FREE = 111;
enum DSO_F_DSO_GET_FILENAME = 127;
enum DSO_F_DSO_GET_LOADED_FILENAME = 128;
enum DSO_F_DSO_GLOBAL_LOOKUP = 139;
enum DSO_F_DSO_LOAD = 112;
enum DSO_F_DSO_MERGE = 132;
enum DSO_F_DSO_NEW_METHOD = 113;
enum DSO_F_DSO_PATHBYADDR = 140;
enum DSO_F_DSO_SET_FILENAME = 129;
enum DSO_F_DSO_SET_NAME_CONVERTER = 122;
enum DSO_F_DSO_UP_REF = 114;
enum DSO_F_GLOBAL_LOOKUP_FUNC = 138;
enum DSO_F_PATHBYADDR = 137;
enum DSO_F_VMS_BIND_SYM = 115;
enum DSO_F_VMS_LOAD = 116;
enum DSO_F_VMS_MERGER = 133;
enum DSO_F_VMS_UNLOAD = 117;
enum DSO_F_WIN32_BIND_FUNC = 118;
enum DSO_F_WIN32_BIND_VAR = 119;
enum DSO_F_WIN32_GLOBALLOOKUP = 142;
enum DSO_F_WIN32_GLOBALLOOKUP_FUNC = 143;
enum DSO_F_WIN32_JOINER = 135;
enum DSO_F_WIN32_LOAD = 120;
enum DSO_F_WIN32_MERGER = 134;
enum DSO_F_WIN32_NAME_CONVERTER = 125;
enum DSO_F_WIN32_PATHBYADDR = 141;
enum DSO_F_WIN32_SPLITTER = 136;
enum DSO_F_WIN32_UNLOAD = 121;

/* Reason codes. */
enum DSO_R_CTRL_FAILED = 100;
enum DSO_R_DSO_ALREADY_LOADED = 110;
enum DSO_R_EMPTY_FILE_STRUCTURE = 113;
enum DSO_R_FAILURE = 114;
enum DSO_R_FILENAME_TOO_BIG = 101;
enum DSO_R_FINISH_FAILED = 102;
enum DSO_R_INCORRECT_FILE_SYNTAX = 115;
enum DSO_R_LOAD_FAILED = 103;
enum DSO_R_NAME_TRANSLATION_FAILED = 109;
enum DSO_R_NO_FILENAME = 111;
enum DSO_R_NO_FILE_SPECIFICATION = 116;
enum DSO_R_NULL_HANDLE = 104;
enum DSO_R_SET_FILENAME_FAILED = 112;
enum DSO_R_STACK_ERROR = 105;
enum DSO_R_SYM_FAILURE = 106;
enum DSO_R_UNLOAD_FAILED = 107;
enum DSO_R_UNSUPPORTED = 108;