apache-http-server/server/util_ebcdic.c

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 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
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 *    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.
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 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * 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/>.
 *
 * Portions of this software are based upon public domain software
 * originally written at the National Center for Supercomputing Applications,
 * University of Illinois, Urbana-Champaign.
 */

#include "ap_config.h"

#ifdef CHARSET_EBCDIC

#include "httpd.h"
#include "http_log.h"
#include "http_core.h"
#include "util_ebcdic.h"

ap_status_t ap_init_ebcdic(ap_pool_t *pool)
{
    ap_status_t rv;
    char buf[80];

    rv = ap_xlate_open(&ap_hdrs_to_ascii, "ISO8859-1", APR_DEFAULT_CHARSET, pool);
    if (rv) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                     "ap_xlate_open() failed");
        return rv;
    }

    rv = ap_xlate_open(&ap_hdrs_from_ascii, APR_DEFAULT_CHARSET, "ISO8859-1", pool);
    if (rv) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                     "ap_xlate_open() failed");
        return rv;
    }

    ap_locale_to_ascii = ap_hdrs_to_ascii; /* TODO: "ISO8859-1" to APR_LOCALE_CHARSET */
    ap_locale_from_ascii = ap_hdrs_from_ascii; /* TODO: APR_LOCALE_CHARSET to "ISO8859-1" */

    rv = ap_MD5InitEBCDIC(ap_hdrs_to_ascii);
    if (rv) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                     "ap_MD5InitEBCDIC() failed");
        return rv;
    }
    
    rv = ap_base64init_ebcdic(ap_hdrs_to_ascii, ap_hdrs_from_ascii);
    if (rv) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                     "ap_base64init_ebcdic() failed");
        return rv;
    }
    
    rv = ap_SHA1InitEBCDIC(ap_hdrs_to_ascii);
    if (rv) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                     "ap_SHA1InitEBCDIC() failed");
        return rv;
    }
    
    return APR_SUCCESS;
}

#define ASCIITEXT_MAGIC_TYPE_PREFIX "text/x-ascii-" /* Text files whose content-type starts with this are passed thru unconverted */

/* Check the Content-Type to decide if conversion is needed */
ap_xlate_t *ap_checkconv(struct request_rec *r)
{
    int convert_to_ascii;
    const char *type;
    ap_xlate_t *zero = NULL;

    /* To make serving of "raw ASCII text" files easy (they serve faster 
     * since they don't have to be converted from EBCDIC), a new
     * "magic" type prefix was invented: text/x-ascii-{plain,html,...}
     * If we detect one of these content types here, we simply correct
     * the type to the real text/{plain,html,...} type. Otherwise, we
     * set a flag that translation is required later on.
     */

    type = (r->content_type == NULL) ? ap_default_type(r) : r->content_type;

    /* If no content type is set then treat it as (ebcdic) text/plain */
    convert_to_ascii = (type == NULL);

    /* Conversion is applied to text/ files only, if ever. */
    if (type && (strncasecmp(type, "text/", 5) == 0 ||
		 strncasecmp(type, "message/", 8) == 0)) {
	if (strncasecmp(type, ASCIITEXT_MAGIC_TYPE_PREFIX,
			sizeof(ASCIITEXT_MAGIC_TYPE_PREFIX)-1) == 0)
	    r->content_type = ap_pstrcat(r->pool, "text/",
					 type+sizeof(ASCIITEXT_MAGIC_TYPE_PREFIX)-1,
					 NULL);
        else
	    /* translate EBCDIC to ASCII */
	    convert_to_ascii = 1;
    }
    /* Turn off conversion if it's not a text document */
    if (!convert_to_ascii) {
        ap_set_content_xlate(r, 1, zero);
    }

    return convert_to_ascii ? ap_locale_to_ascii : NULL;
}

#endif /* CHARSET_EBCDIC */