switch_dso.c

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/* 
 * Cross Platform dso/dll load abstraction
 * Copyright(C) 2008 Michael Jerris
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so.
 *
 * This work is provided under this license on an "as is" basis, without warranty of any kind,
 * either expressed or implied, including, without limitation, warranties that the covered code
 * is free of defects, merchantable, fit for a particular purpose or non-infringing. The entire
 * risk as to the quality and performance of the covered code is with you. Should any covered
 * code prove defective in any respect, you (not the initial developer or any other contributor)
 * assume the cost of any necessary servicing, repair or correction. This disclaimer of warranty
 * constitutes an essential part of this license. No use of any covered code is authorized hereunder
 * except under this disclaimer. 
 *
 */

#include <switch.h>
#include "switch_dso.h"
#include <stdlib.h>
#include <string.h>

#ifdef WIN32

SWITCH_DECLARE(void) switch_dso_destroy(switch_dso_lib_t *lib)
{
        if (lib && *lib) {
                FreeLibrary(*lib);
                *lib = NULL;
        }
}

SWITCH_DECLARE(switch_dso_lib_t) switch_dso_open(const char *path, int global, char **err)
{
        HINSTANCE lib;

        lib = LoadLibraryEx(path, NULL, 0);

        if (!lib) {
                LoadLibraryEx(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
        }

        if (!lib) {
                DWORD error = GetLastError();
                *err = switch_mprintf("dll open error [%ul]\n", error);
        }

        return lib;
}

SWITCH_DECLARE(switch_dso_func_t) switch_dso_func_sym(switch_dso_lib_t lib, const char *sym, char **err)
{
        FARPROC func = GetProcAddress(lib, sym);
        if (!func) {
                DWORD error = GetLastError();
                *err = switch_mprintf("dll sym error [%ul]\n", error);
        }
        return (switch_dso_func_t) func;
}

SWITCH_DECLARE(void *) switch_dso_data_sym(switch_dso_lib_t lib, const char *sym, char **err)
{
        FARPROC addr = GetProcAddress(lib, sym);
        if (!addr) {
                DWORD error = GetLastError();
                *err = switch_mprintf("dll sym error [%ul]\n", error);
        }
        return (void *) (intptr_t) addr;
}


#else
/*
** {========================================================================
** This is an implementation of loadlib based on the dlfcn interface.
** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
** as an emulation layer on top of native functions.
** =========================================================================
*/


#include <dlfcn.h>

void switch_dso_destroy(switch_dso_lib_t *lib)
{
        if (lib && *lib) {
                dlclose(*lib);
                *lib = NULL;
        }
}

switch_dso_lib_t switch_dso_open(const char *path, int global, char **err)
{
        void *lib;

        if (global) {
                lib = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
        } else {
                lib = dlopen(path, RTLD_NOW | RTLD_LOCAL);
        }

        if (lib == NULL) {
                const char *dlerr = dlerror();
                /* Work around broken uclibc returning NULL on both dlopen() and dlerror() */
                if (dlerr) {
                        *err = strdup(dlerr);
                } else {
                        *err = strdup("Unknown error");
                }
        }
        return lib;
}

switch_dso_func_t switch_dso_func_sym(switch_dso_lib_t lib, const char *sym, char **err)
{
        void *func = dlsym(lib, sym);
        if (!func) {
                *err = strdup(dlerror());
        }
        return (switch_dso_func_t) (intptr_t) func;
}

void *switch_dso_data_sym(switch_dso_lib_t lib, const char *sym, char **err)
{
        void *addr = dlsym(lib, sym);
        if (!addr) {
                char *err_str = NULL;
                dlerror();

                if (!(addr = dlsym(lib, sym))) {
                        err_str = (char *)dlerror();
                }

                if (err_str) {
                        *err = strdup(err_str);
                }
        }
        return addr;
}

#endif
/* }====================================================== */

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