/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2002 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",
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 *    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/>.
 *
 * 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 "apr_strings.h"
#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_protocol.h"
#include "http_log.h"
#include "util_script.h"
#include "http_main.h"
#include "http_request.h"

#include "mod_core.h"

#define ASIS_MAGIC_TYPE "httpd/send-as-is"

static int asis_handler(request_rec *r)
{
    conn_rec *c = r->connection;
    apr_file_t *f = NULL;
    apr_status_t rv;
    const char *location;

    if(strcmp(r->handler,ASIS_MAGIC_TYPE) && strcmp(r->handler,"send-as-is"))
	return DECLINED;

    r->allowed |= (AP_METHOD_BIT << M_GET);
    if (r->method_number != M_GET)
	return DECLINED;
    if (r->finfo.filetype == 0) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
		    "File does not exist: %s", r->filename);
	return HTTP_NOT_FOUND;
    }

    if ((rv = apr_file_open(&f, r->filename, APR_READ, 
                APR_OS_DEFAULT, r->pool)) != APR_SUCCESS) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
		    "file permissions deny server access: %s", r->filename);
	return HTTP_FORBIDDEN;
    }

    ap_scan_script_header_err(r, f, NULL);
    location = apr_table_get(r->headers_out, "Location");

    if (location && location[0] == '/' &&
	((r->status == HTTP_OK) || ap_is_HTTP_REDIRECT(r->status))) {

	apr_file_close(f);

	/* Internal redirect -- fake-up a pseudo-request */
	r->status = HTTP_OK;

	/* This redirect needs to be a GET no matter what the original
	 * method was.
	 */
	r->method = apr_pstrdup(r->pool, "GET");
	r->method_number = M_GET;

	ap_internal_redirect_handler(location, r);
	return OK;
    }

    if (!r->header_only) {
        apr_bucket_brigade *bb;
        apr_bucket *b;
        apr_off_t pos = 0;

        rv = apr_file_seek(f, APR_CUR, &pos);
        if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                          "mod_asis: failed to find end-of-headers position "
                          "for %s", r->filename);
            apr_file_close(f);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        bb = apr_brigade_create(r->pool, c->bucket_alloc);
#if APR_HAS_LARGE_FILES
        if (r->finfo.size - pos > AP_MAX_SENDFILE) {
            /* APR_HAS_LARGE_FILES issue; must split into mutiple buckets, 
             * no greater than MAX(apr_size_t), and more granular than that
             * in case the brigade code/filters attempt to read it directly.
             */
            apr_off_t fsize = r->finfo.size - pos;
            b = apr_bucket_file_create(f, pos, AP_MAX_SENDFILE,
                                       r->pool, c->bucket_alloc);
            while (fsize > AP_MAX_SENDFILE) {
                APR_BRIGADE_INSERT_TAIL(bb, b);
                apr_bucket_copy(b, &b);
                b->start += AP_MAX_SENDFILE;
                fsize -= AP_MAX_SENDFILE;
            }
            b->length = (apr_size_t)fsize; /* Resize just the last bucket */
        }
        else
#endif
        b = apr_bucket_file_create(f, pos, (apr_size_t) (r->finfo.size - pos),
                                   r->pool, c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);
        b = apr_bucket_eos_create(c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);
        rv = ap_pass_brigade(r->output_filters, bb);
        if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                          "mod_asis: ap_pass_brigade failed for file %s", r->filename);
            return HTTP_INTERNAL_SERVER_ERROR;
        }
    }
    else {
        apr_file_close(f);
    }

    return OK;
}

static void register_hooks(apr_pool_t *p)
{
    ap_hook_handler(asis_handler,NULL,NULL,APR_HOOK_MIDDLE);
}

module AP_MODULE_DECLARE_DATA asis_module =
{
    STANDARD20_MODULE_STUFF,
    NULL,			/* create per-directory config structure */
    NULL,			/* merge per-directory config structures */
    NULL,			/* create per-server config structure */
    NULL,			/* merge per-server config structures */
    NULL,			/* command apr_table_t */
    register_hooks		/* register hooks */
};
