/* Copyright 1999-2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "apr_strings.h"
#include "apr_thread_proc.h"    /* for RLIMIT stuff */

#define APR_WANT_STRFUNC
#include "apr_want.h"

#define CORE_PRIVATE
#include "httpd.h"
#include "http_config.h"
#include "http_connection.h"
#include "http_core.h"
#include "http_protocol.h"	/* For index_of_response().  Grump. */
#include "http_request.h"

#include "util_filter.h"
#include "util_ebcdic.h"
#include "ap_mpm.h"
#include "scoreboard.h"

#include "mod_core.h"

/* Handles for core filters */
AP_DECLARE_DATA ap_filter_rec_t *ap_http_input_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_http_header_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_chunk_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_byterange_filter_handle;

static const char *set_keep_alive_timeout(cmd_parms *cmd, void *dummy,
					  const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE|NOT_IN_LIMIT);
    if (err != NULL) {
        return err;
    }

    cmd->server->keep_alive_timeout = apr_time_from_sec(atoi(arg));
    return NULL;
}

static const char *set_keep_alive(cmd_parms *cmd, void *dummy,
				  const char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE|NOT_IN_LIMIT);
    if (err != NULL) {
        return err;
    }

    /* We've changed it to On/Off, but used to use numbers
     * so we accept anything but "Off" or "0" as "On"
     */
    if (!strcasecmp(arg, "off") || !strcmp(arg, "0")) {
	cmd->server->keep_alive = 0;
    }
    else {
	cmd->server->keep_alive = 1;
    }
    return NULL;
}

static const char *set_keep_alive_max(cmd_parms *cmd, void *dummy,
				      const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE|NOT_IN_LIMIT);
    if (err != NULL) {
        return err;
    }

    cmd->server->keep_alive_max = atoi(arg);
    return NULL;
}

static const command_rec http_cmds[] = {
    AP_INIT_TAKE1("KeepAliveTimeout", set_keep_alive_timeout, NULL, RSRC_CONF,
                  "Keep-Alive timeout duration (sec)"),
    AP_INIT_TAKE1("MaxKeepAliveRequests", set_keep_alive_max, NULL, RSRC_CONF,
                  "Maximum number of Keep-Alive requests per connection, "
                  "or 0 for infinite"),
    AP_INIT_TAKE1("KeepAlive", set_keep_alive, NULL, RSRC_CONF,
                  "Whether persistent connections should be On or Off"),
    { NULL }
};

static const char *http_scheme(const request_rec *r)
{
    return "http";
}

static apr_port_t http_port(const request_rec *r)
{
    return DEFAULT_HTTP_PORT;
}

static int ap_process_http_async_connection(conn_rec *c)
{
    request_rec *r;
    conn_state_t *cs = c->cs;
    
    AP_DEBUG_ASSERT(cs->state == CONN_STATE_READ_REQUEST_LINE);
    
    while (cs->state == CONN_STATE_READ_REQUEST_LINE) {
        ap_update_child_status(c->sbh, SERVER_BUSY_READ, NULL);
            
        if ((r = ap_read_request(c))) {

            c->keepalive = AP_CONN_UNKNOWN;
            /* process the request if it was read without error */
                                                       
            ap_update_child_status(c->sbh, SERVER_BUSY_WRITE, r);
            if (r->status == HTTP_OK)
                ap_process_request(r);

            if (ap_extended_status)
                ap_increment_counts(c->sbh, r);

            if (c->keepalive != AP_CONN_KEEPALIVE || c->aborted 
                    || ap_graceful_stop_signalled()) {
                cs->state = CONN_STATE_LINGER;
            }
            else if (!c->data_in_input_filters) {
                cs->state = CONN_STATE_CHECK_REQUEST_LINE_READABLE;
            }

            /* else we are pipelining.  Stay in READ_REQUEST_LINE state
             *  and stay in the loop
             */

            apr_pool_destroy(r->pool);
        }
        else {   /* ap_read_request failed - client may have closed */
            cs->state = CONN_STATE_LINGER;
        }
    }

    return OK;
}

static int ap_process_http_connection(conn_rec *c)
{
    request_rec *r;
    int csd_set = 0;
    apr_socket_t *csd = NULL;

    /*
     * Read and process each request found on our connection
     * until no requests are left or we decide to close.
     */
 
    ap_update_child_status(c->sbh, SERVER_BUSY_READ, NULL);
    while ((r = ap_read_request(c)) != NULL) {

        c->keepalive = AP_CONN_UNKNOWN;
        /* process the request if it was read without error */
 
        ap_update_child_status(c->sbh, SERVER_BUSY_WRITE, r);
        if (r->status == HTTP_OK)
            ap_process_request(r);
 
        if (ap_extended_status)
            ap_increment_counts(c->sbh, r);
 
        if (c->keepalive != AP_CONN_KEEPALIVE || c->aborted)
            break;
 
        ap_update_child_status(c->sbh, SERVER_BUSY_KEEPALIVE, r);
        apr_pool_destroy(r->pool);
 
        if (ap_graceful_stop_signalled())
            break;
        /* Go straight to select() to wait for the next request */
        if (!csd_set) {
            csd = ap_get_module_config(c->conn_config, &core_module);
            csd_set = 1;
        }
        apr_socket_opt_set(csd, APR_INCOMPLETE_READ, 1);
    }
 
    return OK;
}

static int http_create_request(request_rec *r)
{
    if (!r->main && !r->prev) {
        ap_add_output_filter_handle(ap_byterange_filter_handle,
                                    NULL, r, r->connection);
        ap_add_output_filter_handle(ap_content_length_filter_handle,
                                    NULL, r, r->connection);
        ap_add_output_filter_handle(ap_http_header_filter_handle,
                                    NULL, r, r->connection);
    }

    return OK;
}

static void register_hooks(apr_pool_t *p)
{
    /**
     * If we ae using an MPM That Supports Async Connections,
     * use a different processing function
     */
    int async_mpm = 0;
    if (ap_mpm_query(AP_MPMQ_IS_ASYNC, &async_mpm) == APR_SUCCESS 
        && async_mpm == 1) {
        ap_hook_process_connection(ap_process_http_async_connection, NULL,
                                   NULL, APR_HOOK_REALLY_LAST);
    }
    else {
        ap_hook_process_connection(ap_process_http_connection, NULL, NULL, 
                                   APR_HOOK_REALLY_LAST);
    }

    ap_hook_map_to_storage(ap_send_http_trace,NULL,NULL,APR_HOOK_MIDDLE);
    ap_hook_http_scheme(http_scheme,NULL,NULL,APR_HOOK_REALLY_LAST);
    ap_hook_default_port(http_port,NULL,NULL,APR_HOOK_REALLY_LAST);
    ap_hook_create_request(http_create_request, NULL, NULL, APR_HOOK_REALLY_LAST);
    ap_http_input_filter_handle =
        ap_register_input_filter("HTTP_IN", ap_http_filter,
                                 NULL, AP_FTYPE_PROTOCOL);
    ap_http_header_filter_handle =
        ap_register_output_filter("HTTP_HEADER", ap_http_header_filter, 
                                  NULL, AP_FTYPE_PROTOCOL);
    ap_chunk_filter_handle =
        ap_register_output_filter("CHUNK", ap_http_chunk_filter,
                                  NULL, AP_FTYPE_TRANSCODE);
    ap_byterange_filter_handle =
        ap_register_output_filter("BYTERANGE", ap_byterange_filter,
                                  NULL, AP_FTYPE_PROTOCOL);
    ap_method_registry_init(p);
}

module AP_MODULE_DECLARE_DATA http_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 */
    http_cmds,			/* command apr_table_t */
    register_hooks		/* register hooks */
};
