/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  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. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``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 APACHE SOFTWARE FOUNDATION 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
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 * 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 software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#include "dso.h"
#include "apr_strings.h"

#if APR_HAS_DSO

#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
#if APR_HAVE_STRING_H
#include <string.h> /* for strerror() on HP-UX */
#endif

static apr_status_t dso_cleanup(void *thedso)
{
    apr_dso_handle_t *dso = thedso;

    if (dso->handle == NULL)
        return APR_SUCCESS;

#if defined(HPUX) || defined(HPUX10) || defined(HPUX11)
    shl_unload((shl_t)dso->handle);
#elif defined(DARWIN)
    NSUnLinkModule(dso->handle, FALSE);
#else
    if (dlclose(dso->handle) != 0)
        return APR_EINIT;
#endif
    dso->handle = NULL;

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_dso_load(apr_dso_handle_t **res_handle, 
                                       const char *path, apr_pool_t *ctx)
{
#if defined(HPUX) || defined(HPUX10) || defined(HPUX11)
    shl_t os_handle = shl_load(path, BIND_IMMEDIATE|BIND_VERBOSE|BIND_NOSTART, 0L);

#elif defined(DARWIN)
    NSObjectFileImage image;
    NSModule os_handle;
    char* err_msg = NULL;
    if (NSCreateObjectFileImageFromFile(path, &image) != NSObjectFileImageSuccess) {
	err_msg = "cannot create object file image";
    }
    else {
#ifdef NSLINKMODULE_OPTION_PRIVATE
      os_handle = NSLinkModule(image, path,
			       NSLINKMODULE_OPTION_PRIVATE |
			       NSLINKMODULE_OPTION_RETURN_ON_ERROR);
#else
      os_handle = NSLinkModule(image, path, TRUE);
#endif
    }

#elif defined(OSF1) || defined(SEQUENT) || defined(SNI) ||\
    (defined(__FreeBSD_version) && (__FreeBSD_version >= 220000))
    void *os_handle = dlopen((char *)path, RTLD_NOW | RTLD_GLOBAL);

#else
    void *os_handle = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
#endif    

    *res_handle = apr_pcalloc(ctx, sizeof(**res_handle));

    if(os_handle == NULL) {
#if defined(HPUX) || defined(HPUX10) || defined(HPUX11)
        (*res_handle)->errormsg = strerror(errno);
        return errno;
#elif defined(DARWIN)
        (*res_handle)->errormsg = (err_msg) ? err_msg : "link failed";
        return APR_EDSOOPEN;
#else
        (*res_handle)->errormsg = dlerror();
        return APR_EDSOOPEN;
#endif
    }

    (*res_handle)->handle = (void*)os_handle;
    (*res_handle)->cont = ctx;
    (*res_handle)->errormsg = NULL;

    apr_pool_cleanup_register(ctx, *res_handle, dso_cleanup, apr_pool_cleanup_null);

    return APR_SUCCESS;
}
    
APR_DECLARE(apr_status_t) apr_dso_unload(apr_dso_handle_t *handle)
{
    return apr_pool_cleanup_run(handle->cont, handle, dso_cleanup);
}

APR_DECLARE(apr_status_t) apr_dso_sym(apr_dso_handle_sym_t *ressym, 
                                      apr_dso_handle_t *handle, 
                                      const char *symname)
{
#if defined(HPUX) || defined(HPUX10) || defined(HPUX11)
    void *symaddr = NULL;
    int status;

    errno = 0;
    status = shl_findsym((shl_t *)&handle->handle, symname, TYPE_PROCEDURE, &symaddr);
    if (status == -1 && errno == 0) /* try TYPE_DATA instead */
        status = shl_findsym((shl_t *)&handle->handle, symname, TYPE_DATA, &symaddr);
    if (status = -1)
        return APR_EINIT;
    *ressym = symaddr;
    return APR_SUCCESS;

#elif defined(DARWIN)
    void *retval = NULL;
    NSSymbol symbol;
    char *symname2 = (char*)malloc(sizeof(char)*(strlen(symname)+2));
    sprintf(symname2, "_%s", symname);
#ifdef NSLINKMODULE_OPTION_PRIVATE
    symbol = NSLookupSymbolInModule((NSModule)handle->handle, symname2);
#else
    symbol = NSLookupAndBindSymbol(symname2);
#endif
    free(symname2);
    if (symbol == NULL) {
        handle->errormsg = "undefined symbol";
	return APR_EINIT;
    }
    retval = NSAddressOfSymbol(symbol);
    if (retval == NULL) {
        handle->errormsg = "cannot resolve symbol";
	return APR_EINIT;
    }

#else /* use dlsym()/dlerror() */

#if defined(DLSYM_NEEDS_UNDERSCORE)
    void *retval;
    char *symbol = (char*)malloc(sizeof(char)*(strlen(symname)+2));
    sprintf(symbol, "_%s", symname);
    retval = dlsym(handle->handle, symbol);
    free(symbol);

#elif defined(SEQUENT) || defined(SNI)
    void *retval = dlsym(handle->handle, (char *)symname);
#else
    void *retval = dlsym(handle->handle, symname);
#endif

    if (retval == NULL) {
        handle->errormsg = dlerror();
        return APR_EINIT;
    }

    *ressym = retval;
    
    return APR_SUCCESS;
#endif /* use dlsym()/dlerror() */
}

APR_DECLARE(const char *) apr_dso_error(apr_dso_handle_t *dso, char *buffer, apr_size_t buflen)
{
    if (dso->errormsg) {
        apr_cpystrn(buffer, dso->errormsg, buflen);
        return dso->errormsg;
    }
    return "No Error";
}

#endif