/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.h"
#include "apr_strings.h"
#include "apr_lib.h"
#include "apr_fnmatch.h"
#include "apr_hash.h"
#include "apr_thread_proc.h"    /* for RLIMIT stuff */
#include "apr_random.h"

#define APR_WANT_IOVEC
#define APR_WANT_STRFUNC
#define APR_WANT_MEMFUNC
#include "apr_want.h"

#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_protocol.h" /* For index_of_response().  Grump. */
#include "http_request.h"
#include "http_vhost.h"
#include "http_main.h"     /* For the default_handler below... */
#include "http_log.h"
#include "util_md5.h"
#include "http_connection.h"
#include "apr_buckets.h"
#include "util_filter.h"
#include "util_ebcdic.h"
#include "util_mutex.h"
#include "util_time.h"
#include "mpm_common.h"
#include "scoreboard.h"
#include "mod_core.h"
#include "mod_proxy.h"
#include "ap_listen.h"
#include "ap_provider.h"

#include "mod_so.h" /* for ap_find_loaded_module_symbol */

#if defined(RLIMIT_CPU) || defined (RLIMIT_DATA) || defined (RLIMIT_VMEM) || defined(RLIMIT_AS) || defined (RLIMIT_NPROC)
#include "unixd.h"
#endif
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif

/* LimitRequestBody handling */
#define AP_LIMIT_REQ_BODY_UNSET         ((apr_off_t) -1)
#define AP_DEFAULT_LIMIT_REQ_BODY       ((apr_off_t) 0)

/* LimitXMLRequestBody handling */
#define AP_LIMIT_UNSET                  ((long) -1)
#define AP_DEFAULT_LIMIT_XML_BODY       ((apr_size_t)1000000)

#define AP_MIN_SENDFILE_BYTES           (256)

/* maximum include nesting level */
#ifndef AP_MAX_INCLUDE_DEPTH
#define AP_MAX_INCLUDE_DEPTH            (128)
#endif

/* valid in core-conf, but not in runtime r->used_path_info */
#define AP_ACCEPT_PATHINFO_UNSET 3

#define AP_CONTENT_MD5_OFF   0
#define AP_CONTENT_MD5_ON    1
#define AP_CONTENT_MD5_UNSET 2

APR_HOOK_STRUCT(
    APR_HOOK_LINK(get_mgmt_items)
    APR_HOOK_LINK(insert_network_bucket)
)

AP_IMPLEMENT_HOOK_RUN_ALL(int, get_mgmt_items,
                          (apr_pool_t *p, const char *val, apr_hash_t *ht),
                          (p, val, ht), OK, DECLINED)

AP_IMPLEMENT_HOOK_RUN_FIRST(apr_status_t, insert_network_bucket,
                            (conn_rec *c, apr_bucket_brigade *bb,
                             apr_socket_t *socket),
                            (c, bb, socket), AP_DECLINED)

/* Server core module... This module provides support for really basic
 * server operations, including options and commands which control the
 * operation of other modules.  Consider this the bureaucracy module.
 *
 * The core module also defines handlers, etc., to handle just enough
 * to allow a server with the core module ONLY to actually serve documents.
 *
 * This file could almost be mod_core.c, except for the stuff which affects
 * the http_conf_globals.
 */

/* we know core's module_index is 0 */
#undef APLOG_MODULE_INDEX
#define APLOG_MODULE_INDEX AP_CORE_MODULE_INDEX

/* Handles for core filters */
AP_DECLARE_DATA ap_filter_rec_t *ap_subreq_core_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_request_core_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_core_output_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_content_length_filter_handle;
AP_DECLARE_DATA ap_filter_rec_t *ap_core_input_filter_handle;

/* Provide ap_document_root_check storage and default value = true */
AP_DECLARE_DATA int ap_document_root_check = 1;

/* magic pointer for ErrorDocument xxx "default" */
static char errordocument_default;

static apr_array_header_t *saved_server_config_defines = NULL;
static apr_table_t *server_config_defined_vars = NULL;

AP_DECLARE_DATA int ap_main_state = AP_SQ_MS_INITIAL_STARTUP;
AP_DECLARE_DATA int ap_run_mode = AP_SQ_RM_UNKNOWN;
AP_DECLARE_DATA int ap_config_generation = 0;

typedef struct {
    apr_ipsubnet_t *subnet;
    struct ap_logconf log;
} conn_log_config;

static void *create_core_dir_config(apr_pool_t *a, char *dir)
{
    core_dir_config *conf;

    conf = (core_dir_config *)apr_pcalloc(a, sizeof(core_dir_config));

    /* conf->r and conf->d[_*] are initialized by dirsection() or left NULL */

    conf->opts = dir ? OPT_UNSET : OPT_UNSET|OPT_SYM_LINKS;
    conf->opts_add = conf->opts_remove = OPT_NONE;
    conf->override = OR_UNSET|OR_NONE;
    conf->override_opts = OPT_UNSET | OPT_ALL | OPT_SYM_OWNER | OPT_MULTI;

    conf->content_md5 = AP_CONTENT_MD5_UNSET;
    conf->accept_path_info = AP_ACCEPT_PATHINFO_UNSET;

    conf->use_canonical_name = USE_CANONICAL_NAME_UNSET;
    conf->use_canonical_phys_port = USE_CANONICAL_PHYS_PORT_UNSET;

    conf->hostname_lookups = HOSTNAME_LOOKUP_UNSET;

    /*
     * left as NULL (we use apr_pcalloc):
     * conf->limit_cpu = NULL;
     * conf->limit_mem = NULL;
     * conf->limit_nproc = NULL;
     * conf->sec_file = NULL;
     * conf->sec_if   = NULL;
     */

    conf->limit_req_body = AP_LIMIT_REQ_BODY_UNSET;
    conf->limit_xml_body = AP_LIMIT_UNSET;

    conf->server_signature = srv_sig_unset;

    conf->add_default_charset = ADD_DEFAULT_CHARSET_UNSET;
    conf->add_default_charset_name = DEFAULT_ADD_DEFAULT_CHARSET_NAME;

    /* Overriding all negotiation
     * Set NULL by apr_pcalloc:
     * conf->mime_type = NULL;
     * conf->handler = NULL;
     * conf->output_filters = NULL;
     * conf->input_filters = NULL;
     */

    /*
     * Flag for use of inodes in ETags.
     */
    conf->etag_bits = ETAG_UNSET;
    conf->etag_add = ETAG_UNSET;
    conf->etag_remove = ETAG_UNSET;

    conf->enable_mmap = ENABLE_MMAP_UNSET;
    conf->enable_sendfile = ENABLE_SENDFILE_UNSET;
    conf->allow_encoded_slashes = 0;
    conf->decode_encoded_slashes = 0;

    conf->max_ranges = AP_MAXRANGES_UNSET;
    conf->max_overlaps = AP_MAXRANGES_UNSET;
    conf->max_reversals = AP_MAXRANGES_UNSET;

    conf->cgi_pass_auth = AP_CGI_PASS_AUTH_UNSET;
    conf->qualify_redirect_url = AP_CORE_CONFIG_UNSET; 

    return (void *)conf;
}

static void *merge_core_dir_configs(apr_pool_t *a, void *basev, void *newv)
{
    core_dir_config *base = (core_dir_config *)basev;
    core_dir_config *new = (core_dir_config *)newv;
    core_dir_config *conf;

    /* Create this conf by duplicating the base, replacing elements
     * (or creating copies for merging) where new-> values exist.
     */
    conf = (core_dir_config *)apr_pmemdup(a, base, sizeof(core_dir_config));

    conf->d = new->d;
    conf->d_is_fnmatch = new->d_is_fnmatch;
    conf->d_components = new->d_components;
    conf->r = new->r;
    conf->refs = new->refs;
    conf->condition = new->condition;

    if (new->opts & OPT_UNSET) {
        /* there was no explicit setting of new->opts, so we merge
         * preserve the invariant (opts_add & opts_remove) == 0
         */
        conf->opts_add = (conf->opts_add & ~new->opts_remove) | new->opts_add;
        conf->opts_remove = (conf->opts_remove & ~new->opts_add)
                            | new->opts_remove;
        conf->opts = (conf->opts & ~conf->opts_remove) | conf->opts_add;

        /* If Includes was enabled with exec in the base config, but
         * was enabled without exec in the new config, then disable
         * exec in the merged set. */
        if (((base->opts & (OPT_INCLUDES|OPT_INC_WITH_EXEC))
             == (OPT_INCLUDES|OPT_INC_WITH_EXEC))
            && ((new->opts & (OPT_INCLUDES|OPT_INC_WITH_EXEC))
                == OPT_INCLUDES)) {
            conf->opts &= ~OPT_INC_WITH_EXEC;
        }
    }
    else {
        /* otherwise we just copy, because an explicit opts setting
         * overrides all earlier +/- modifiers
         */
        conf->opts = new->opts;
        conf->opts_add = new->opts_add;
        conf->opts_remove = new->opts_remove;
    }

    if (!(new->override & OR_UNSET)) {
        conf->override = new->override;
    }

    if (!(new->override_opts & OPT_UNSET)) {
        conf->override_opts = new->override_opts;
    }

    if (new->override_list != NULL) {
        conf->override_list = new->override_list;
    }

    if (conf->response_code_exprs == NULL) {
        conf->response_code_exprs = new->response_code_exprs;
    }
    else if (new->response_code_exprs != NULL) {
        conf->response_code_exprs = apr_hash_overlay(a,
                new->response_code_exprs, conf->response_code_exprs);
    }
    /* Otherwise we simply use the base->response_code_exprs array
     */

    if (new->hostname_lookups != HOSTNAME_LOOKUP_UNSET) {
        conf->hostname_lookups = new->hostname_lookups;
    }

    if (new->content_md5 != AP_CONTENT_MD5_UNSET) {
        conf->content_md5 = new->content_md5;
    }

    if (new->accept_path_info != AP_ACCEPT_PATHINFO_UNSET) {
        conf->accept_path_info = new->accept_path_info;
    }

    if (new->use_canonical_name != USE_CANONICAL_NAME_UNSET) {
        conf->use_canonical_name = new->use_canonical_name;
    }

    if (new->use_canonical_phys_port != USE_CANONICAL_PHYS_PORT_UNSET) {
        conf->use_canonical_phys_port = new->use_canonical_phys_port;
    }

#ifdef RLIMIT_CPU
    if (new->limit_cpu) {
        conf->limit_cpu = new->limit_cpu;
    }
#endif

#if defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_AS)
    if (new->limit_mem) {
        conf->limit_mem = new->limit_mem;
    }
#endif

#ifdef RLIMIT_NPROC
    if (new->limit_nproc) {
        conf->limit_nproc = new->limit_nproc;
    }
#endif

    if (new->limit_req_body != AP_LIMIT_REQ_BODY_UNSET) {
        conf->limit_req_body = new->limit_req_body;
    }

    if (new->limit_xml_body != AP_LIMIT_UNSET)
        conf->limit_xml_body = new->limit_xml_body;

    if (!conf->sec_file) {
        conf->sec_file = new->sec_file;
    }
    else if (new->sec_file) {
        /* If we merge, the merge-result must have its own array
         */
        conf->sec_file = apr_array_append(a, base->sec_file, new->sec_file);
    }
    /* Otherwise we simply use the base->sec_file array
     */

    if (!conf->sec_if) {
        conf->sec_if = new->sec_if;
    }
    else if (new->sec_if) {
        /* If we merge, the merge-result must have its own array
         */
        conf->sec_if = apr_array_append(a, base->sec_if, new->sec_if);
    }
    /* Otherwise we simply use the base->sec_if array
     */

    if (new->server_signature != srv_sig_unset) {
        conf->server_signature = new->server_signature;
    }

    if (new->add_default_charset != ADD_DEFAULT_CHARSET_UNSET) {
        conf->add_default_charset = new->add_default_charset;
        conf->add_default_charset_name = new->add_default_charset_name;
    }

    /* Overriding all negotiation
     */
    if (new->mime_type) {
        conf->mime_type = new->mime_type;
    }

    if (new->handler) {
        conf->handler = new->handler;
    }
    if (new->expr_handler) {
        conf->expr_handler = new->expr_handler;
    }

    if (new->output_filters) {
        conf->output_filters = new->output_filters;
    }

    if (new->input_filters) {
        conf->input_filters = new->input_filters;
    }

    /*
     * Now merge the setting of the FileETag directive.
     */
    if (new->etag_bits == ETAG_UNSET) {
        conf->etag_add =
            (conf->etag_add & (~ new->etag_remove)) | new->etag_add;
        conf->etag_remove =
            (conf->etag_remove & (~ new->etag_add)) | new->etag_remove;
        conf->etag_bits =
            (conf->etag_bits & (~ conf->etag_remove)) | conf->etag_add;
    }
    else {
        conf->etag_bits = new->etag_bits;
        conf->etag_add = new->etag_add;
        conf->etag_remove = new->etag_remove;
    }

    if (conf->etag_bits != ETAG_NONE) {
        conf->etag_bits &= (~ ETAG_NONE);
    }

    if (new->enable_mmap != ENABLE_MMAP_UNSET) {
        conf->enable_mmap = new->enable_mmap;
    }

    if (new->enable_sendfile != ENABLE_SENDFILE_UNSET) {
        conf->enable_sendfile = new->enable_sendfile;
    }

    if (new->allow_encoded_slashes_set) {
        conf->allow_encoded_slashes = new->allow_encoded_slashes;
    }
    if (new->decode_encoded_slashes_set) {
        conf->decode_encoded_slashes = new->decode_encoded_slashes;
    }

    if (new->log) {
        if (!conf->log) {
            conf->log = new->log;
        }
        else {
            conf->log = ap_new_log_config(a, new->log);
            ap_merge_log_config(base->log, conf->log);
        }
    }

    conf->max_ranges = new->max_ranges != AP_MAXRANGES_UNSET ? new->max_ranges : base->max_ranges;
    conf->max_overlaps = new->max_overlaps != AP_MAXRANGES_UNSET ? new->max_overlaps : base->max_overlaps;
    conf->max_reversals = new->max_reversals != AP_MAXRANGES_UNSET ? new->max_reversals : base->max_reversals;

    conf->cgi_pass_auth = new->cgi_pass_auth != AP_CGI_PASS_AUTH_UNSET ? new->cgi_pass_auth : base->cgi_pass_auth;

    if (new->cgi_var_rules) {
        if (!conf->cgi_var_rules) {
            conf->cgi_var_rules = new->cgi_var_rules;
        }
        else {
            conf->cgi_var_rules = apr_hash_overlay(a, new->cgi_var_rules, conf->cgi_var_rules);
        }
    }

    AP_CORE_MERGE_FLAG(qualify_redirect_url, conf, base, new);

    return (void*)conf;
}

#if APR_HAS_SO_ACCEPTFILTER
#ifndef ACCEPT_FILTER_NAME
#define ACCEPT_FILTER_NAME "httpready"
#ifdef __FreeBSD_version
#if __FreeBSD_version < 411000 /* httpready broken before 4.1.1 */
#undef ACCEPT_FILTER_NAME
#define ACCEPT_FILTER_NAME "dataready"
#endif
#endif
#endif
#endif

static void *create_core_server_config(apr_pool_t *a, server_rec *s)
{
    core_server_config *conf;
    int is_virtual = s->is_virtual;

    conf = (core_server_config *)apr_pcalloc(a, sizeof(core_server_config));

    /* global-default / global-only settings */

    if (!is_virtual) {
        conf->ap_document_root = DOCUMENT_LOCATION;
        conf->access_name = DEFAULT_ACCESS_FNAME;

        /* A mapping only makes sense in the global context */
        conf->accf_map = apr_table_make(a, 5);
#if APR_HAS_SO_ACCEPTFILTER
        apr_table_setn(conf->accf_map, "http", ACCEPT_FILTER_NAME);
        apr_table_setn(conf->accf_map, "https", "dataready");
#else
        apr_table_setn(conf->accf_map, "http", "data");
        apr_table_setn(conf->accf_map, "https", "data");
#endif
    }
    /* pcalloc'ed - we have NULL's/0's
    else ** is_virtual ** {
        conf->ap_document_root = NULL;
        conf->access_name = NULL;
        conf->accf_map = NULL;
    }
     */

    /* initialization, no special case for global context */

    conf->sec_dir = apr_array_make(a, 40, sizeof(ap_conf_vector_t *));
    conf->sec_url = apr_array_make(a, 40, sizeof(ap_conf_vector_t *));

    /* pcalloc'ed - we have NULL's/0's
    conf->gprof_dir = NULL;

    ** recursion stopper; 0 == unset
    conf->redirect_limit = 0;
    conf->subreq_limit = 0;

    conf->protocol = NULL;
     */

    conf->trace_enable = AP_TRACE_UNSET;

    conf->protocols = apr_array_make(a, 5, sizeof(const char *));
    conf->protocols_honor_order = -1;
    conf->async_filter = 0;

    return (void *)conf;
}

static void *merge_core_server_configs(apr_pool_t *p, void *basev, void *virtv)
{
    core_server_config *base = (core_server_config *)basev;
    core_server_config *virt = (core_server_config *)virtv;
    core_server_config *conf = (core_server_config *)
                               apr_pmemdup(p, base, sizeof(core_server_config));

    if (virt->ap_document_root)
        conf->ap_document_root = virt->ap_document_root;

    if (virt->access_name)
        conf->access_name = virt->access_name;

    /* XXX optimize to keep base->sec_ pointers if virt->sec_ array is empty */
    conf->sec_dir = apr_array_append(p, base->sec_dir, virt->sec_dir);
    conf->sec_url = apr_array_append(p, base->sec_url, virt->sec_url);

    if (virt->redirect_limit)
        conf->redirect_limit = virt->redirect_limit;

    if (virt->subreq_limit)
        conf->subreq_limit = virt->subreq_limit;

    if (virt->trace_enable != AP_TRACE_UNSET)
        conf->trace_enable = virt->trace_enable;

    if (virt->http09_enable != AP_HTTP09_UNSET)
        conf->http09_enable = virt->http09_enable;

    if (virt->http_conformance != AP_HTTP_CONFORMANCE_UNSET)
        conf->http_conformance = virt->http_conformance;

    if (virt->http_cl_head_zero != AP_HTTP_CL_HEAD_ZERO_UNSET)
        conf->http_cl_head_zero = virt->http_cl_head_zero;

    if (virt->http_expect_strict != AP_HTTP_EXPECT_STRICT_UNSET)
        conf->http_expect_strict = virt->http_expect_strict;

    /* no action for virt->accf_map, not allowed per-vhost */

    if (virt->protocol)
        conf->protocol = virt->protocol;

    if (virt->gprof_dir)
        conf->gprof_dir = virt->gprof_dir;

    if (virt->error_log_format)
        conf->error_log_format = virt->error_log_format;

    if (virt->error_log_conn)
        conf->error_log_conn = virt->error_log_conn;

    if (virt->error_log_req)
        conf->error_log_req = virt->error_log_req;

    if (virt->conn_log_level) {
        if (!conf->conn_log_level) {
            conf->conn_log_level = virt->conn_log_level;
        }
        else {
            /* apr_array_append actually creates a new array */
            conf->conn_log_level = apr_array_append(p, conf->conn_log_level,
                                                    virt->conn_log_level);
        }
    }

    conf->merge_trailers = (virt->merge_trailers != AP_MERGE_TRAILERS_UNSET)
                           ? virt->merge_trailers
                           : base->merge_trailers;

    conf->protocols = ((virt->protocols->nelts > 0) ?
                       virt->protocols : base->protocols);
    conf->protocols_honor_order = ((virt->protocols_honor_order < 0) ?
                                       base->protocols_honor_order :
                                       virt->protocols_honor_order);
    conf->async_filter = ((virt->async_filter_set) ?
                                       virt->async_filter :
                                       base->async_filter);
    conf->async_filter_set = base->async_filter_set || virt->async_filter_set;

    return conf;
}

/* Add per-directory configuration entry (for <directory> section);
 * these are part of the core server config.
 */

AP_CORE_DECLARE(void) ap_add_per_dir_conf(server_rec *s, void *dir_config)
{
    core_server_config *sconf = ap_get_core_module_config(s->module_config);
    void **new_space = (void **)apr_array_push(sconf->sec_dir);

    *new_space = dir_config;
}

AP_CORE_DECLARE(void) ap_add_per_url_conf(server_rec *s, void *url_config)
{
    core_server_config *sconf = ap_get_core_module_config(s->module_config);
    void **new_space = (void **)apr_array_push(sconf->sec_url);

    *new_space = url_config;
}

AP_CORE_DECLARE(void) ap_add_file_conf(apr_pool_t *p, core_dir_config *conf,
                                       void *url_config)
{
    void **new_space;

    if (!conf->sec_file)
        conf->sec_file = apr_array_make(p, 2, sizeof(ap_conf_vector_t *));

    new_space = (void **)apr_array_push(conf->sec_file);
    *new_space = url_config;
}

AP_CORE_DECLARE(const char *) ap_add_if_conf(apr_pool_t *p,
                                             core_dir_config *conf,
                                             void *if_config)
{
    void **new_space;
    core_dir_config *new = ap_get_module_config(if_config, &core_module);

    if (!conf->sec_if) {
        conf->sec_if = apr_array_make(p, 2, sizeof(ap_conf_vector_t *));
    }
    if (new->condition_ifelse & AP_CONDITION_ELSE) {
        int have_if = 0;
        if (conf->sec_if->nelts > 0) {
            core_dir_config *last;
            ap_conf_vector_t *lastelt = APR_ARRAY_IDX(conf->sec_if,
                                                      conf->sec_if->nelts - 1,
                                                      ap_conf_vector_t *);
            last = ap_get_module_config(lastelt, &core_module);
            if (last->condition_ifelse & AP_CONDITION_IF)
                have_if = 1;
        }
        if (!have_if)
            return "<Else> or <ElseIf> section without previous <If> or "
                   "<ElseIf> section in same scope";
    }

    new_space = (void **)apr_array_push(conf->sec_if);
    *new_space = if_config;
    return NULL;
}


/* We need to do a stable sort, qsort isn't stable.  So to make it stable
 * we'll be maintaining the original index into the list, and using it
 * as the minor key during sorting.  The major key is the number of
 * components (where the root component is zero).
 */
struct reorder_sort_rec {
    ap_conf_vector_t *elt;
    int orig_index;
};

static int reorder_sorter(const void *va, const void *vb)
{
    const struct reorder_sort_rec *a = va;
    const struct reorder_sort_rec *b = vb;
    core_dir_config *core_a;
    core_dir_config *core_b;

    core_a = ap_get_core_module_config(a->elt);
    core_b = ap_get_core_module_config(b->elt);

    /* a regex always sorts after a non-regex
     */
    if (!core_a->r && core_b->r) {
        return -1;
    }
    else if (core_a->r && !core_b->r) {
        return 1;
    }

    /* we always sort next by the number of components
     */
    if (core_a->d_components < core_b->d_components) {
        return -1;
    }
    else if (core_a->d_components > core_b->d_components) {
        return 1;
    }

    /* They have the same number of components, we now have to compare
     * the minor key to maintain the original order (from the config.)
     */
    return a->orig_index - b->orig_index;
}

void ap_core_reorder_directories(apr_pool_t *p, server_rec *s)
{
    core_server_config *sconf;
    apr_array_header_t *sec_dir;
    struct reorder_sort_rec *sortbin;
    int nelts;
    ap_conf_vector_t **elts;
    int i;
    apr_pool_t *tmp;

    sconf = ap_get_core_module_config(s->module_config);
    sec_dir = sconf->sec_dir;
    nelts = sec_dir->nelts;
    elts = (ap_conf_vector_t **)sec_dir->elts;

    if (!nelts) {
        /* simple case of already being sorted... */
        /* We're not checking this condition to be fast... we're checking
         * it to avoid trying to palloc zero bytes, which can trigger some
         * memory debuggers to barf
         */
        return;
    }

    /* we have to allocate tmp space to do a stable sort */
    apr_pool_create(&tmp, p);
    sortbin = apr_palloc(tmp, sec_dir->nelts * sizeof(*sortbin));
    for (i = 0; i < nelts; ++i) {
        sortbin[i].orig_index = i;
        sortbin[i].elt = elts[i];
    }

    qsort(sortbin, nelts, sizeof(*sortbin), reorder_sorter);

    /* and now copy back to the original array */
    for (i = 0; i < nelts; ++i) {
        elts[i] = sortbin[i].elt;
    }

    apr_pool_destroy(tmp);
}

/*****************************************************************
 *
 * There are some elements of the core config structures in which
 * other modules have a legitimate interest (this is ugly, but necessary
 * to preserve NCSA back-compatibility).  So, we have a bunch of accessors
 * here...
 */

AP_DECLARE(int) ap_allow_options(request_rec *r)
{
    core_dir_config *conf =
      (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    return conf->opts;
}

AP_DECLARE(int) ap_allow_overrides(request_rec *r)
{
    core_dir_config *conf;
    conf = (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    return conf->override;
}

/*
 * Optional function coming from mod_authn_core, used for
 * retrieving the type of autorization
 */
static APR_OPTIONAL_FN_TYPE(authn_ap_auth_type) *authn_ap_auth_type;

AP_DECLARE(const char *) ap_auth_type(request_rec *r)
{
    if (authn_ap_auth_type) {
        return authn_ap_auth_type(r);
    }
    return NULL;
}

/*
 * Optional function coming from mod_authn_core, used for
 * retrieving the authorization realm
 */
static APR_OPTIONAL_FN_TYPE(authn_ap_auth_name) *authn_ap_auth_name;

AP_DECLARE(const char *) ap_auth_name(request_rec *r)
{
    if (authn_ap_auth_name) {
        return authn_ap_auth_name(r);
    }
    return NULL;
}

/*
 * Optional function coming from mod_access_compat, used to determine how
   access control interacts with authentication/authorization
 */
static APR_OPTIONAL_FN_TYPE(access_compat_ap_satisfies) *access_compat_ap_satisfies;

AP_DECLARE(int) ap_satisfies(request_rec *r)
{
    if (access_compat_ap_satisfies) {
        return access_compat_ap_satisfies(r);
    }
    return SATISFY_NOSPEC;
}

AP_DECLARE(const char *) ap_document_root(request_rec *r) /* Don't use this! */
{
    core_server_config *sconf;
    core_request_config *rconf = ap_get_core_module_config(r->request_config);
    if (rconf->document_root)
        return rconf->document_root;
    sconf = ap_get_core_module_config(r->server->module_config);
    return sconf->ap_document_root;
}

AP_DECLARE(const char *) ap_context_prefix(request_rec *r)
{
    core_request_config *conf = ap_get_core_module_config(r->request_config);
    if (conf->context_prefix)
        return conf->context_prefix;
    else
        return "";
}

AP_DECLARE(const char *) ap_context_document_root(request_rec *r)
{
    core_request_config *conf = ap_get_core_module_config(r->request_config);
    if (conf->context_document_root)
        return conf->context_document_root;
    else
        return ap_document_root(r);
}

AP_DECLARE(void) ap_set_document_root(request_rec *r, const char *document_root)
{
    core_request_config *conf = ap_get_core_module_config(r->request_config);
    conf->document_root = document_root;
}

AP_DECLARE(void) ap_set_context_info(request_rec *r, const char *context_prefix,
                                     const char *context_document_root)
{
    core_request_config *conf = ap_get_core_module_config(r->request_config);
    if (context_prefix)
        conf->context_prefix = context_prefix;
    if (context_document_root)
        conf->context_document_root = context_document_root;
}

/* Should probably just get rid of this... the only code that cares is
 * part of the core anyway (and in fact, it isn't publicised to other
 * modules).
 */

char *ap_response_code_string(request_rec *r, int error_index)
{
    core_dir_config *dirconf;
    core_request_config *reqconf = ap_get_core_module_config(r->request_config);
    const char *err;
    const char *response;
    ap_expr_info_t *expr;

    /* check for string registered via ap_custom_response() first */
    if (reqconf->response_code_strings != NULL
            && reqconf->response_code_strings[error_index] != NULL) {
        return reqconf->response_code_strings[error_index];
    }

    /* check for string specified via ErrorDocument */
    dirconf = ap_get_core_module_config(r->per_dir_config);

    if (!dirconf->response_code_exprs) {
        return NULL;
    }

    expr = apr_hash_get(dirconf->response_code_exprs, &error_index,
            sizeof(error_index));
    if (!expr) {
        return NULL;
    }

    /* special token to indicate revert back to default */
    if ((char *) expr == &errordocument_default) {
        return NULL;
    }

    err = NULL;
    response = ap_expr_str_exec(r, expr, &err);
    if (err) {
        ap_log_rerror(
                APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02841) "core: ErrorDocument: can't "
                "evaluate require expression: %s", err);
        return NULL;
    }

    /* alas, duplication required as we return not-const */
    return apr_pstrdup(r->pool, response);
}


/* Code from Harald Hanche-Olsen <hanche@imf.unit.no> */
static APR_INLINE int do_double_reverse (int double_reverse,
                                         const char *remote_host,
                                         apr_sockaddr_t *client_addr,
                                         apr_pool_t *pool)
{
    apr_sockaddr_t *sa;
    apr_status_t rv;

    if (double_reverse) {
        /* already done */
        return double_reverse;
    }

    if (remote_host == NULL || remote_host[0] == '\0') {
        /* single reverse failed, so don't bother */
        return -1;
    }

    rv = apr_sockaddr_info_get(&sa, remote_host, APR_UNSPEC, 0, 0, pool);
    if (rv == APR_SUCCESS) {
        while (sa) {
            if (apr_sockaddr_equal(sa, client_addr)) {
                return 1;
            }

            sa = sa->next;
        }
    }

    return -1;
}

AP_DECLARE(const char *) ap_get_remote_host(conn_rec *conn, void *dir_config,
                                            int type, int *str_is_ip)
{
    int hostname_lookups;
    int ignored_str_is_ip;

    if (!str_is_ip) { /* caller doesn't want to know */
        str_is_ip = &ignored_str_is_ip;
    }
    *str_is_ip = 0;

    /* If we haven't checked the host name, and we want to */
    if (dir_config) {
        hostname_lookups = ((core_dir_config *)ap_get_core_module_config(dir_config))
                           ->hostname_lookups;

        if (hostname_lookups == HOSTNAME_LOOKUP_UNSET) {
            hostname_lookups = HOSTNAME_LOOKUP_OFF;
        }
    }
    else {
        /* the default */
        hostname_lookups = HOSTNAME_LOOKUP_OFF;
    }

    if (type != REMOTE_NOLOOKUP
        && conn->remote_host == NULL
        && (type == REMOTE_DOUBLE_REV
        || hostname_lookups != HOSTNAME_LOOKUP_OFF)) {

        if (apr_getnameinfo(&conn->remote_host, conn->client_addr, 0)
            == APR_SUCCESS) {
            ap_str_tolower(conn->remote_host);

            if (hostname_lookups == HOSTNAME_LOOKUP_DOUBLE) {
                conn->double_reverse = do_double_reverse(conn->double_reverse,
                                                         conn->remote_host,
                                                         conn->client_addr,
                                                         conn->pool);
                if (conn->double_reverse != 1) {
                    conn->remote_host = NULL;
                }
            }
        }

        /* if failed, set it to the NULL string to indicate error */
        if (conn->remote_host == NULL) {
            conn->remote_host = "";
        }
    }

    if (type == REMOTE_DOUBLE_REV) {
        conn->double_reverse = do_double_reverse(conn->double_reverse,
                                                 conn->remote_host,
                                                 conn->client_addr, conn->pool);
        if (conn->double_reverse == -1) {
            return NULL;
        }
    }

    /*
     * Return the desired information; either the remote DNS name, if found,
     * or either NULL (if the hostname was requested) or the IP address
     * (if any identifier was requested).
     */
    if (conn->remote_host != NULL && conn->remote_host[0] != '\0') {
        return conn->remote_host;
    }
    else {
        if (type == REMOTE_HOST || type == REMOTE_DOUBLE_REV) {
            return NULL;
        }
        else {
            *str_is_ip = 1;
            return conn->client_ip;
        }
    }
}

AP_DECLARE(const char *) ap_get_useragent_host(request_rec *r,
                                               int type, int *str_is_ip)
{
    conn_rec *conn = r->connection;
    int hostname_lookups;
    int ignored_str_is_ip;

    /* Guard here when examining the host before the read_request hook
     * has populated an r->useragent_addr
     */
    if (!r->useragent_addr || (r->useragent_addr == conn->client_addr)) {
        return ap_get_remote_host(conn, r->per_dir_config, type, str_is_ip);
    }

    if (!str_is_ip) { /* caller doesn't want to know */
        str_is_ip = &ignored_str_is_ip;
    }
    *str_is_ip = 0;

    hostname_lookups = ((core_dir_config *)
                        ap_get_core_module_config(r->per_dir_config))
                            ->hostname_lookups;
    if (hostname_lookups == HOSTNAME_LOOKUP_UNSET) {
        hostname_lookups = HOSTNAME_LOOKUP_OFF;
    }

    if (type != REMOTE_NOLOOKUP
        && r->useragent_host == NULL
        && (type == REMOTE_DOUBLE_REV
        || hostname_lookups != HOSTNAME_LOOKUP_OFF)) {

        if (apr_getnameinfo(&r->useragent_host, r->useragent_addr, 0)
            == APR_SUCCESS) {
            ap_str_tolower(r->useragent_host);

            if (hostname_lookups == HOSTNAME_LOOKUP_DOUBLE) {
                r->double_reverse = do_double_reverse(r->double_reverse,
                                                      r->useragent_host,
                                                      r->useragent_addr,
                                                      r->pool);
                if (r->double_reverse != 1) {
                    r->useragent_host = NULL;
                }
            }
        }

        /* if failed, set it to the NULL string to indicate error */
        if (r->useragent_host == NULL) {
            r->useragent_host = "";
        }
    }

    if (type == REMOTE_DOUBLE_REV) {
        r->double_reverse = do_double_reverse(r->double_reverse,
                                              r->useragent_host,
                                              r->useragent_addr, r->pool);
        if (r->double_reverse == -1) {
            return NULL;
        }
    }

    /*
     * Return the desired information; either the remote DNS name, if found,
     * or either NULL (if the hostname was requested) or the IP address
     * (if any identifier was requested).
     */
    if (r->useragent_host != NULL && r->useragent_host[0] != '\0') {
        return r->useragent_host;
    }
    else {
        if (type == REMOTE_HOST || type == REMOTE_DOUBLE_REV) {
            return NULL;
        }
        else {
            *str_is_ip = 1;
            return r->useragent_ip;
        }
    }
}

/*
 * Optional function coming from mod_ident, used for looking up ident user
 */
static APR_OPTIONAL_FN_TYPE(ap_ident_lookup) *ident_lookup;

AP_DECLARE(const char *) ap_get_remote_logname(request_rec *r)
{
    if (r->connection->remote_logname != NULL) {
        return r->connection->remote_logname;
    }

    if (ident_lookup) {
        return ident_lookup(r);
    }

    return NULL;
}

/* There are two options regarding what the "name" of a server is.  The
 * "canonical" name as defined by ServerName and Port, or the "client's
 * name" as supplied by a possible Host: header or full URI.
 *
 * The DNS option to UseCanonicalName causes this routine to do a
 * reverse lookup on the local IP address of the connection and use
 * that for the ServerName. This makes its value more reliable while
 * at the same time allowing Demon's magic virtual hosting to work.
 * The assumption is that DNS lookups are sufficiently quick...
 * -- fanf 1998-10-03
 */
AP_DECLARE(const char *) ap_get_server_name(request_rec *r)
{
    conn_rec *conn = r->connection;
    core_dir_config *d;
    const char *retval;

    d = (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    switch (d->use_canonical_name) {
        case USE_CANONICAL_NAME_ON:
            retval = r->server->server_hostname;
            break;
        case USE_CANONICAL_NAME_DNS:
            if (conn->local_host == NULL) {
                if (apr_getnameinfo(&conn->local_host,
                                conn->local_addr, 0) != APR_SUCCESS)
                    conn->local_host = apr_pstrdup(conn->pool,
                                               r->server->server_hostname);
                else {
                    ap_str_tolower(conn->local_host);
                }
            }
            retval = conn->local_host;
            break;
        case USE_CANONICAL_NAME_OFF:
        case USE_CANONICAL_NAME_UNSET:
            retval = r->hostname ? r->hostname : r->server->server_hostname;
            break;
        default:
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00109)
                         "ap_get_server_name: Invalid UCN Option somehow");
            retval = "localhost";
            break;
    }
    return retval;
}

/*
 * Get the current server name from the request for the purposes
 * of using in a URL.  If the server name is an IPv6 literal
 * address, it will be returned in URL format (e.g., "[fe80::1]").
 */
AP_DECLARE(const char *) ap_get_server_name_for_url(request_rec *r)
{
    const char *plain_server_name = ap_get_server_name(r);

#if APR_HAVE_IPV6
    if (ap_strchr_c(plain_server_name, ':')) { /* IPv6 literal? */
        return apr_pstrcat(r->pool, "[", plain_server_name, "]", NULL);
    }
#endif
    return plain_server_name;
}

AP_DECLARE(apr_port_t) ap_get_server_port(const request_rec *r)
{
    apr_port_t port;
    core_dir_config *d =
      (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    switch (d->use_canonical_name) {
        case USE_CANONICAL_NAME_OFF:
        case USE_CANONICAL_NAME_DNS:
        case USE_CANONICAL_NAME_UNSET:
            if (d->use_canonical_phys_port == USE_CANONICAL_PHYS_PORT_ON)
                port = r->parsed_uri.port_str ? r->parsed_uri.port :
                       r->connection->local_addr->port ? r->connection->local_addr->port :
                       r->server->port ? r->server->port :
                       ap_default_port(r);
            else /* USE_CANONICAL_PHYS_PORT_OFF or USE_CANONICAL_PHYS_PORT_UNSET */
                port = r->parsed_uri.port_str ? r->parsed_uri.port :
                       r->server->port ? r->server->port :
                       ap_default_port(r);
            break;
        case USE_CANONICAL_NAME_ON:
            /* With UseCanonicalName on (and in all versions prior to 1.3)
             * Apache will use the hostname and port specified in the
             * ServerName directive to construct a canonical name for the
             * server. (If no port was specified in the ServerName
             * directive, Apache uses the port supplied by the client if
             * any is supplied, and finally the default port for the protocol
             * used.
             */
            if (d->use_canonical_phys_port == USE_CANONICAL_PHYS_PORT_ON)
                port = r->server->port ? r->server->port :
                       r->connection->local_addr->port ? r->connection->local_addr->port :
                       ap_default_port(r);
            else /* USE_CANONICAL_PHYS_PORT_OFF or USE_CANONICAL_PHYS_PORT_UNSET */
                port = r->server->port ? r->server->port :
                       ap_default_port(r);
            break;
        default:
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00110)
                         "ap_get_server_port: Invalid UCN Option somehow");
            port = ap_default_port(r);
            break;
    }

    return port;
}

AP_DECLARE(char *) ap_construct_url(apr_pool_t *p, const char *uri,
                                    request_rec *r)
{
    unsigned port = ap_get_server_port(r);
    const char *host = ap_get_server_name_for_url(r);

    if (ap_is_default_port(port, r)) {
        return apr_pstrcat(p, ap_http_scheme(r), "://", host, uri, NULL);
    }

    return apr_psprintf(p, "%s://%s:%u%s", ap_http_scheme(r), host, port, uri);
}

AP_DECLARE(apr_off_t) ap_get_limit_req_body(const request_rec *r)
{
    core_dir_config *d =
      (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    if (d->limit_req_body == AP_LIMIT_REQ_BODY_UNSET) {
        return AP_DEFAULT_LIMIT_REQ_BODY;
    }

    return d->limit_req_body;
}


/*****************************************************************
 *
 * Commands... this module handles almost all of the NCSA httpd.conf
 * commands, but most of the old srm.conf is in the modules.
 */


/* returns a parent if it matches the given directive */
static const ap_directive_t * find_parent(const ap_directive_t *dirp,
                                          const char *what)
{
    while (dirp->parent != NULL) {
        dirp = dirp->parent;

        /* ### it would be nice to have atom-ized directives */
        if (ap_cstr_casecmp(dirp->directive, what) == 0)
            return dirp;
    }

    return NULL;
}

AP_DECLARE(const char *) ap_check_cmd_context(cmd_parms *cmd,
                                              unsigned forbidden)
{
    const char *gt = (cmd->cmd->name[0] == '<'
                      && cmd->cmd->name[strlen(cmd->cmd->name)-1] != '>')
                         ? ">" : "";
    const ap_directive_t *found;

    if ((forbidden & NOT_IN_VIRTUALHOST) && cmd->server->is_virtual) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name, gt,
                           " cannot occur within <VirtualHost> section", NULL);
    }

    if ((forbidden & (NOT_IN_LIMIT | NOT_IN_DIR_LOC_FILE))
        && cmd->limited != -1) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name, gt,
                           " cannot occur within <Limit> or <LimitExcept> "
                           "section", NULL);
    }

    if ((forbidden & NOT_IN_HTACCESS) && (cmd->pool == cmd->temp_pool)) {
         return apr_pstrcat(cmd->pool, cmd->cmd->name, gt,
                            " cannot occur within htaccess files", NULL);
    }

    if ((forbidden & NOT_IN_DIR_LOC_FILE) == NOT_IN_DIR_LOC_FILE) {
        if (cmd->path != NULL) {
            return apr_pstrcat(cmd->pool, cmd->cmd->name, gt,
                            " cannot occur within <Directory/Location/Files> "
                            "section", NULL);
        }
        if (cmd->cmd->req_override & EXEC_ON_READ) {
            /* EXEC_ON_READ must be NOT_IN_DIR_LOC_FILE, if not, it will
             * (deliberately) segfault below in the individual tests...
             */
            return NULL;
        }
    }

    if (((forbidden & NOT_IN_DIRECTORY)
         && ((found = find_parent(cmd->directive, "<Directory"))
             || (found = find_parent(cmd->directive, "<DirectoryMatch"))))
        || ((forbidden & NOT_IN_LOCATION)
            && ((found = find_parent(cmd->directive, "<Location"))
                || (found = find_parent(cmd->directive, "<LocationMatch"))))
        || ((forbidden & NOT_IN_FILES)
            && ((found = find_parent(cmd->directive, "<Files"))
                || (found = find_parent(cmd->directive, "<FilesMatch"))
                || (found = find_parent(cmd->directive, "<If"))
                || (found = find_parent(cmd->directive, "<ElseIf"))
                || (found = find_parent(cmd->directive, "<Else"))))
        || ((forbidden & NOT_IN_PROXY)
            && ((found = find_parent(cmd->directive, "<Proxy"))
                || (found = find_parent(cmd->directive, "<ProxyMatch"))))) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name, gt,
                           " cannot occur within ", found->directive,
                           "> section", NULL);
    }

    return NULL;
}

static const char *set_access_name(cmd_parms *cmd, void *dummy,
                                   const char *arg)
{
    void *sconf = cmd->server->module_config;
    core_server_config *conf = ap_get_core_module_config(sconf);

    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    conf->access_name = apr_pstrdup(cmd->pool, arg);
    return NULL;
}

AP_DECLARE(const char *) ap_resolve_env(apr_pool_t *p, const char * word)
{
# define SMALL_EXPANSION 5
    struct sll {
        struct sll *next;
        const char *string;
        apr_size_t len;
    } *result, *current, sresult[SMALL_EXPANSION];
    char *res_buf, *cp;
    const char *s, *e, *ep;
    unsigned spc;
    apr_size_t outlen;

    s = ap_strchr_c(word, '$');
    if (!s) {
        return word;
    }

    /* well, actually something to do */
    ep = word + strlen(word);
    spc = 0;
    result = current = &(sresult[spc++]);
    current->next = NULL;
    current->string = word;
    current->len = s - word;
    outlen = current->len;

    do {
        /* prepare next entry */
        if (current->len) {
            current->next = (spc < SMALL_EXPANSION)
                            ? &(sresult[spc++])
                            : (struct sll *)apr_palloc(p,
                                                       sizeof(*current->next));
            current = current->next;
            current->next = NULL;
            current->len = 0;
        }

        if (*s == '$') {
            if (s[1] == '{' && (e = ap_strchr_c(s+2, '}'))) {
                char *name = apr_pstrmemdup(p, s+2, e-s-2);
                word = NULL;
                if (server_config_defined_vars)
                    word = apr_table_get(server_config_defined_vars, name);
                if (!word)
                    word = getenv(name);
                if (word) {
                    current->string = word;
                    current->len = strlen(word);
                    outlen += current->len;
                }
                else {
                    if (ap_strchr(name, ':') == 0)
                        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, NULL, APLOGNO(00111)
                                     "Config variable ${%s} is not defined",
                                     name);
                    current->string = s;
                    current->len = e - s + 1;
                    outlen += current->len;
                }
                s = e + 1;
            }
            else {
                current->string = s++;
                current->len = 1;
                ++outlen;
            }
        }
        else {
            word = s;
            s = ap_strchr_c(s, '$');
            current->string = word;
            current->len = s ? s - word : ep - word;
            outlen += current->len;
        }
    } while (s && *s);

    /* assemble result */
    res_buf = cp = apr_palloc(p, outlen + 1);
    do {
        if (result->len) {
            memcpy(cp, result->string, result->len);
            cp += result->len;
        }
        result = result->next;
    } while (result);
    res_buf[outlen] = '\0';

    return res_buf;
}

static int reset_config_defines(void *dummy)
{
    ap_server_config_defines = saved_server_config_defines;
    saved_server_config_defines = NULL;
    server_config_defined_vars = NULL;
    return OK;
}

/*
 * Make sure we can revert the effects of Define/UnDefine when restarting.
 * This function must be called once per loading of the config, before
 * ap_server_config_defines is changed. This may be during reading of the
 * config, which is even before the pre_config hook is run (due to
 * EXEC_ON_READ for Define/UnDefine).
 */
static void init_config_defines(apr_pool_t *pconf)
{
    saved_server_config_defines = ap_server_config_defines;
    /* Use apr_array_copy instead of apr_array_copy_hdr because it does not
     * protect from the way unset_define removes entries.
     */
    ap_server_config_defines = apr_array_copy(pconf, ap_server_config_defines);
}

static const char *set_define(cmd_parms *cmd, void *dummy,
                              const char *name, const char *value)
{
    if (cmd->parent && ap_cstr_casecmp(cmd->parent->directive, "<VirtualHost")) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name, " is not valid in ",
                                      cmd->parent->directive, " context", NULL);
    }

    if (ap_strchr_c(name, ':') != NULL) {
        return "Variable name must not contain ':'";
    }

    if (!saved_server_config_defines) {
        init_config_defines(cmd->pool);
    }
    if (!ap_exists_config_define(name)) {
        const char **newv = (const char **)apr_array_push(ap_server_config_defines);
        *newv = name;
    }
    if (value) {
        if (!server_config_defined_vars) {
            server_config_defined_vars = apr_table_make(cmd->pool, 5);
        }
        apr_table_setn(server_config_defined_vars, name, value);
    }

    return NULL;
}

static const char *unset_define(cmd_parms *cmd, void *dummy,
                                const char *name)
{
    int i;
    char **defines;
    if (cmd->parent && ap_cstr_casecmp(cmd->parent->directive, "<VirtualHost")) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name, " is not valid in ",
                                      cmd->parent->directive, " context", NULL);
    }

    if (ap_strchr_c(name, ':') != NULL) {
        return "Variable name must not contain ':'";
    }

    if (!saved_server_config_defines) {
        init_config_defines(cmd->pool);
    }

    defines = (char **)ap_server_config_defines->elts;
    for (i = 0; i < ap_server_config_defines->nelts; i++) {
        if (strcmp(defines[i], name) == 0) {
            defines[i] = *(char **)apr_array_pop(ap_server_config_defines);
            break;
        }
    }

    if (server_config_defined_vars) {
        apr_table_unset(server_config_defined_vars, name);
    }

    return NULL;
}

static const char *generate_message(cmd_parms *cmd, void *dummy,
                                    const char *arg)
{
    /* cast with 64-bit warning avoidance */
    int level = (cmd->info==(void*)APLOG_ERR)? APLOG_ERR: APLOG_WARNING;
    char * msg;

    /* get position information from wherever we can? */
    ap_configfile_t * cf = cmd->config_file;
    ap_directive_t const * ed1 = cmd->directive;
    ap_directive_t const * ed2 = cmd->err_directive;

    /* expect an argument */
    if (!arg || !*arg) {
        return "The Error or Warning directive was used with no message.";
    }

    /* set message, strip off quotes if necessary */
    msg = (char *)arg;
    if (*arg == '"' || *arg == '\'') {
        apr_size_t len = strlen(arg);
        char last = *(arg + len - 1);

        if (*arg == last) {
            msg = apr_pstrndup(cmd->pool, arg + 1, len - 2);
        }
    }

    /* generate error or warning with a configuration file position.
     * the log is displayed on the terminal as no log file is opened yet.
     */
    ap_log_error(APLOG_MARK, level, 0, NULL,
                 "%s on line %d of %s", msg,
                 cf? cf->line_number:
                   ed1? ed1->line_num:
                     ed2? ed2->line_num: -1,
                 cf? cf->name:
                   ed1? ed1->filename:
                     ed2? ed2->filename: "<UNKNOWN>");

    /* message displayed above, return will stop configuration processing */
    return level==APLOG_ERR?
        "Configuration processing stopped by Error directive": NULL;
}

#ifdef GPROF
static const char *set_gprof_dir(cmd_parms *cmd, void *dummy, const char *arg)
{
    void *sconf = cmd->server->module_config;
    core_server_config *conf = ap_get_core_module_config(sconf);

    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    conf->gprof_dir = arg;
    return NULL;
}
#endif /*GPROF*/

static const char *set_add_default_charset(cmd_parms *cmd,
                                           void *d_, const char *arg)
{
    core_dir_config *d = d_;

    if (!ap_cstr_casecmp(arg, "Off")) {
       d->add_default_charset = ADD_DEFAULT_CHARSET_OFF;
    }
    else if (!ap_cstr_casecmp(arg, "On")) {
       d->add_default_charset = ADD_DEFAULT_CHARSET_ON;
       d->add_default_charset_name = DEFAULT_ADD_DEFAULT_CHARSET_NAME;
    }
    else {
       d->add_default_charset = ADD_DEFAULT_CHARSET_ON;
       d->add_default_charset_name = arg;
    }

    return NULL;
}

static const char *set_document_root(cmd_parms *cmd, void *dummy,
                                     const char *arg)
{
    void *sconf = cmd->server->module_config;
    core_server_config *conf = ap_get_core_module_config(sconf);

    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    /* When ap_document_root_check is false; skip all the stuff below */
    if (!ap_document_root_check) {
       conf->ap_document_root = arg;
       return NULL;
    }

    /* Make it absolute, relative to ServerRoot */
    arg = ap_server_root_relative(cmd->pool, arg);
    if (arg == NULL) {
        return "DocumentRoot must be a directory";
    }

    if (apr_filepath_merge((char**)&conf->ap_document_root, NULL, arg,
                           APR_FILEPATH_TRUENAME, cmd->pool) != APR_SUCCESS
        || !ap_is_directory(cmd->temp_pool, arg)) {
        if (cmd->server->is_virtual) {
            ap_log_perror(APLOG_MARK, APLOG_STARTUP, 0,
                          cmd->pool, APLOGNO(00112)
                          "Warning: DocumentRoot [%s] does not exist",
                          arg);
            conf->ap_document_root = arg;
        }
        else {
            return apr_psprintf(cmd->pool, 
                                "DocumentRoot '%s' is not a directory, or is not readable",
                                arg);
        }
    }
    return NULL;
}

AP_DECLARE(void) ap_custom_response(request_rec *r, int status,
                                    const char *string)
{
    core_request_config *conf = ap_get_core_module_config(r->request_config);
    int idx;

    if (conf->response_code_strings == NULL) {
        conf->response_code_strings =
            apr_pcalloc(r->pool,
                        sizeof(*conf->response_code_strings) * RESPONSE_CODES);
    }

    idx = ap_index_of_response(status);

    conf->response_code_strings[idx] =
       ((ap_is_url(string) || (*string == '/')) && (*string != '"')) ?
       apr_pstrdup(r->pool, string) : apr_pstrcat(r->pool, "\"", string, NULL);
}

static const char *set_error_document(cmd_parms *cmd, void *conf_,
                                      const char *errno_str, const char *msg)
{
    core_dir_config *conf = conf_;
    int error_number, index_number, idx500;
    enum { MSG, LOCAL_PATH, REMOTE_PATH } what = MSG;

    /* 1st parameter should be a 3 digit number, which we recognize;
     * convert it into an array index
     */
    error_number = atoi(errno_str);
    idx500 = ap_index_of_response(HTTP_INTERNAL_SERVER_ERROR);

    if (error_number == HTTP_INTERNAL_SERVER_ERROR) {
        index_number = idx500;
    }
    else if ((index_number = ap_index_of_response(error_number)) == idx500) {
        return apr_pstrcat(cmd->pool, "Unsupported HTTP response code ",
                           errno_str, NULL);
    }

    /* Heuristic to determine second argument. */
    if (ap_strchr_c(msg,' '))
        what = MSG;
    else if (msg[0] == '/')
        what = LOCAL_PATH;
    else if (ap_is_url(msg))
        what = REMOTE_PATH;
    else
        what = MSG;

    /* The entry should be ignored if it is a full URL for a 401 error */

    if (error_number == 401 && what == REMOTE_PATH) {
        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, cmd->server, APLOGNO(00113)
                     "%s:%d cannot use a full URL in a 401 ErrorDocument "
                     "directive --- ignoring!", cmd->directive->filename, cmd->directive->line_num);
    }
    else { /* Store it... */
        if (conf->response_code_exprs == NULL) {
            conf->response_code_exprs = apr_hash_make(cmd->pool);
        }

        if (ap_cstr_casecmp(msg, "default") == 0) {
            /* special case: ErrorDocument 404 default restores the
             * canned server error response
             */
            apr_hash_set(conf->response_code_exprs,
                    apr_pmemdup(cmd->pool, &index_number, sizeof(index_number)),
                    sizeof(index_number), &errordocument_default);
        }
        else {
            ap_expr_info_t *expr;
            const char *expr_err = NULL;

            /* hack. Prefix a " if it is a msg; as that is what
             * http_protocol.c relies on to distinguish between
             * a msg and a (local) path.
             */
            const char *response =
                    (what == MSG) ? apr_pstrcat(cmd->pool, "\"", msg, NULL) :
                            apr_pstrdup(cmd->pool, msg);

            expr = ap_expr_parse_cmd(cmd, response, AP_EXPR_FLAG_STRING_RESULT,
                    &expr_err, NULL);

            if (expr_err) {
                return apr_pstrcat(cmd->temp_pool,
                                   "Cannot parse expression in ErrorDocument: ",
                                   expr_err, NULL);
            }

            apr_hash_set(conf->response_code_exprs,
                    apr_pmemdup(cmd->pool, &index_number, sizeof(index_number)),
                    sizeof(index_number), expr);

        }
    }

    return NULL;
}

static const char *set_allow_opts(cmd_parms *cmd, allow_options_t *opts,
                                  const char *l)
{
    allow_options_t opt;
    int first = 1;

    char *w, *p = (char *) l;
    char *tok_state;

    while ((w = apr_strtok(p, ",", &tok_state)) != NULL) {

        if (first) {
            p = NULL;
            *opts = OPT_NONE;
            first = 0;
        }

        if (!ap_cstr_casecmp(w, "Indexes")) {
            opt = OPT_INDEXES;
        }
        else if (!ap_cstr_casecmp(w, "Includes")) {
            /* If Includes is permitted, both Includes and
             * IncludesNOEXEC may be changed. */
            opt = (OPT_INCLUDES | OPT_INC_WITH_EXEC);
        }
        else if (!ap_cstr_casecmp(w, "IncludesNOEXEC")) {
            opt = OPT_INCLUDES;
        }
        else if (!ap_cstr_casecmp(w, "FollowSymLinks")) {
            opt = OPT_SYM_LINKS;
        }
        else if (!ap_cstr_casecmp(w, "SymLinksIfOwnerMatch")) {
            opt = OPT_SYM_OWNER;
        }
        else if (!ap_cstr_casecmp(w, "ExecCGI")) {
            opt = OPT_EXECCGI;
        }
        else if (!ap_cstr_casecmp(w, "MultiViews")) {
            opt = OPT_MULTI;
        }
        else if (!ap_cstr_casecmp(w, "RunScripts")) { /* AI backcompat. Yuck */
            opt = OPT_MULTI|OPT_EXECCGI;
        }
        else if (!ap_cstr_casecmp(w, "None")) {
            opt = OPT_NONE;
        }
        else if (!ap_cstr_casecmp(w, "All")) {
            opt = OPT_ALL;
        }
        else {
            return apr_pstrcat(cmd->pool, "Illegal option ", w, NULL);
        }

        *opts |= opt;
    }

    (*opts) &= (~OPT_UNSET);

    return NULL;
}

static const char *set_override(cmd_parms *cmd, void *d_, const char *l)
{
    core_dir_config *d = d_;
    char *w;
    char *k, *v;
    const char *err;

    /* Throw a warning if we're in <Location> or <Files> */
    if (ap_check_cmd_context(cmd, NOT_IN_LOCATION | NOT_IN_FILES)) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00114)
                     "Useless use of AllowOverride in line %d of %s.",
                     cmd->directive->line_num, cmd->directive->filename);
    }
    if ((err = ap_check_cmd_context(cmd, NOT_IN_HTACCESS)) != NULL)
        return err;

    d->override = OR_NONE;
    while (l[0]) {
        w = ap_getword_conf(cmd->temp_pool, &l);

        k = w;
        v = strchr(k, '=');
        if (v) {
                *v++ = '\0';
        }

        if (!ap_cstr_casecmp(w, "Limit")) {
            d->override |= OR_LIMIT;
        }
        else if (!ap_cstr_casecmp(k, "Options")) {
            d->override |= OR_OPTIONS;
            if (v)
                set_allow_opts(cmd, &(d->override_opts), v);
            else
                d->override_opts = OPT_ALL;
        }
        else if (!ap_cstr_casecmp(w, "FileInfo")) {
            d->override |= OR_FILEINFO;
        }
        else if (!ap_cstr_casecmp(w, "AuthConfig")) {
            d->override |= OR_AUTHCFG;
        }
        else if (!ap_cstr_casecmp(w, "Indexes")) {
            d->override |= OR_INDEXES;
        }
        else if (!ap_cstr_casecmp(w, "Nonfatal")) {
            if (!ap_cstr_casecmp(v, "Override")) {
                d->override |= NONFATAL_OVERRIDE;
            }
            else if (!ap_cstr_casecmp(v, "Unknown")) {
                d->override |= NONFATAL_UNKNOWN;
            }
            else if (!ap_cstr_casecmp(v, "All")) {
                d->override |= NONFATAL_ALL;
            }
        }
        else if (!ap_cstr_casecmp(w, "None")) {
            d->override = OR_NONE;
        }
        else if (!ap_cstr_casecmp(w, "All")) {
            d->override = OR_ALL;
        }
        else {
            return apr_pstrcat(cmd->pool, "Illegal override option ", w, NULL);
        }

        d->override &= ~OR_UNSET;
    }

    return NULL;
}

static const char *set_cgi_pass_auth(cmd_parms *cmd, void *d_, int flag)
{
    core_dir_config *d = d_;

    d->cgi_pass_auth = flag ? AP_CGI_PASS_AUTH_ON : AP_CGI_PASS_AUTH_OFF;

    return NULL;
}

static const char *set_cgi_var(cmd_parms *cmd, void *d_,
                               const char *var, const char *rule_)
{
    core_dir_config *d = d_;
    char *rule = apr_pstrdup(cmd->pool, rule_);

    ap_str_tolower(rule);

    if (!strcmp(var, "REQUEST_URI")) {
        if (strcmp(rule, "current-uri") && strcmp(rule, "original-uri")) {
            return "Valid rules for REQUEST_URI are 'current-uri' and 'original-uri'";
        }
    }
    else {
        return apr_pstrcat(cmd->pool, "Unrecognized CGI variable: \"",
                           var, "\"", NULL);
    }

    if (!d->cgi_var_rules) {
        d->cgi_var_rules = apr_hash_make(cmd->pool);
    }
    apr_hash_set(d->cgi_var_rules, var, APR_HASH_KEY_STRING, rule);
    return NULL;
}

static const char *set_qualify_redirect_url(cmd_parms *cmd, void *d_, int flag)
{
    core_dir_config *d = d_;

    d->qualify_redirect_url = flag ? AP_CORE_CONFIG_ON : AP_CORE_CONFIG_OFF;

    return NULL;
}

static const char *set_override_list(cmd_parms *cmd, void *d_, int argc, char *const argv[])
{
    core_dir_config *d = d_;
    int i;
    const char *err;

    /* Throw a warning if we're in <Location> or <Files> */
    if (ap_check_cmd_context(cmd, NOT_IN_LOCATION | NOT_IN_FILES)) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00115)
                     "Useless use of AllowOverrideList at %s:%d",
                     cmd->directive->filename, cmd->directive->line_num);
    }
    if ((err = ap_check_cmd_context(cmd, NOT_IN_HTACCESS)) != NULL)
        return err;

    d->override_list = apr_table_make(cmd->pool, argc);

    for (i = 0; i < argc; i++) {
        if (!ap_cstr_casecmp(argv[i], "None")) {
            if (argc != 1) {
                return "'None' not allowed with other directives in "
                       "AllowOverrideList";
            }
            return NULL;
        }
        else {
            const command_rec *result = NULL;
            module *mod = ap_top_module;

            result = ap_find_command_in_modules(argv[i], &mod);
            if (result == NULL) {
                ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server,
                             APLOGNO(00116) "Discarding unrecognized "
                             "directive `%s' in AllowOverrideList at %s:%d",
                             argv[i], cmd->directive->filename,
                             cmd->directive->line_num);
                continue;
            }
            else if ((result->req_override & (OR_ALL|ACCESS_CONF)) == 0) {
                ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server,
                             APLOGNO(02304) "Discarding directive `%s' not "
                             "allowed in AllowOverrideList at %s:%d",
                             argv[i], cmd->directive->filename,
                             cmd->directive->line_num);
                continue;
            }
            else {
                apr_table_setn(d->override_list, argv[i], "1");
            }
        }
    }

    return NULL;
}

static const char *set_options(cmd_parms *cmd, void *d_, const char *l)
{
    core_dir_config *d = d_;
    allow_options_t opt;
    int first = 1;
    int merge = 0;
    int all_none = 0;
    char action;

    while (l[0]) {
        char *w = ap_getword_conf(cmd->temp_pool, &l);
        action = '\0';

        if (*w == '+' || *w == '-') {
            action = *(w++);
            if (!merge && !first && !all_none) {
                return "Either all Options must start with + or -, or no Option may.";
            }
            merge = 1;
        }
        else if (first) {
            d->opts = OPT_NONE;
        }
        else if (merge) {
            return "Either all Options must start with + or -, or no Option may.";
        }

        if (!ap_cstr_casecmp(w, "Indexes")) {
            opt = OPT_INDEXES;
        }
        else if (!ap_cstr_casecmp(w, "Includes")) {
            opt = (OPT_INCLUDES | OPT_INC_WITH_EXEC);
        }
        else if (!ap_cstr_casecmp(w, "IncludesNOEXEC")) {
            opt = OPT_INCLUDES;
        }
        else if (!ap_cstr_casecmp(w, "FollowSymLinks")) {
            opt = OPT_SYM_LINKS;
        }
        else if (!ap_cstr_casecmp(w, "SymLinksIfOwnerMatch")) {
            opt = OPT_SYM_OWNER;
        }
        else if (!ap_cstr_casecmp(w, "ExecCGI")) {
            opt = OPT_EXECCGI;
        }
        else if (!ap_cstr_casecmp(w, "MultiViews")) {
            opt = OPT_MULTI;
        }
        else if (!ap_cstr_casecmp(w, "RunScripts")) { /* AI backcompat. Yuck */
            opt = OPT_MULTI|OPT_EXECCGI;
        }
        else if (!ap_cstr_casecmp(w, "None")) {
            if (!first) {
                return "'Options None' must be the first Option given.";
            }
            else if (merge) { /* Only works since None may not follow any other option. */
                return "You may not use 'Options +None' or 'Options -None'.";
            }
            opt = OPT_NONE;
            all_none = 1;
        }
        else if (!ap_cstr_casecmp(w, "All")) {
            if (!first) {
                return "'Options All' must be the first option given.";
            }
            else if (merge) { /* Only works since All may not follow any other option. */
                return "You may not use 'Options +All' or 'Options -All'.";
            }
            opt = OPT_ALL;
            all_none = 1;
        }
        else {
            return apr_pstrcat(cmd->pool, "Illegal option ", w, NULL);
        }

        if ( (cmd->override_opts & opt) != opt ) {
            return apr_pstrcat(cmd->pool, "Option ", w, " not allowed here", NULL);
        }
        else if (action == '-') {
            /* we ensure the invariant (d->opts_add & d->opts_remove) == 0 */
            d->opts_remove |= opt;
            d->opts_add &= ~opt;
            d->opts &= ~opt;
        }
        else if (action == '+') {
            d->opts_add |= opt;
            d->opts_remove &= ~opt;
            d->opts |= opt;
        }
        else {
            d->opts |= opt;
        }

        first = 0;
    }

    return NULL;
}

static const char *set_default_type(cmd_parms *cmd, void *d_,
                                   const char *arg)
{
    if (ap_cstr_casecmp(arg, "off") != 0 && ap_cstr_casecmp(arg, "none") != 0) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00117)
              "Ignoring deprecated use of DefaultType in line %d of %s.",
                     cmd->directive->line_num, cmd->directive->filename);
    }

    return NULL;
}

static const char *set_sethandler(cmd_parms *cmd,
                                     void *d_,
                                     const char *arg_)
{
    core_dir_config *dirconf = d_;
    const char *err;
    dirconf->expr_handler = ap_expr_parse_cmd(cmd, arg_,
                                          AP_EXPR_FLAG_STRING_RESULT,
                                          &err, NULL);
    if (err) {
        return apr_pstrcat(cmd->pool,
                "Can't parse expression : ", err, NULL);
    }
    return NULL;
}

/*
 * Note what data should be used when forming file ETag values.
 * It would be nicer to do this as an ITERATE, but then we couldn't
 * remember the +/- state properly.
 */
static const char *set_etag_bits(cmd_parms *cmd, void *mconfig,
                                 const char *args_p)
{
    core_dir_config *cfg;
    etag_components_t bit;
    char action;
    char *token;
    const char *args;
    int valid;
    int first;
    int explicit;

    cfg = (core_dir_config *)mconfig;

    args = args_p;
    first = 1;
    explicit = 0;
    while (args[0] != '\0') {
        action = '*';
        bit = ETAG_UNSET;
        valid = 1;
        token = ap_getword_conf(cmd->temp_pool, &args);
        if ((*token == '+') || (*token == '-')) {
            action = *token;
            token++;
        }
        else {
            /*
             * The occurrence of an absolute setting wipes
             * out any previous relative ones.  The first such
             * occurrence forgets any inherited ones, too.
             */
            if (first) {
                cfg->etag_bits = ETAG_UNSET;
                cfg->etag_add = ETAG_UNSET;
                cfg->etag_remove = ETAG_UNSET;
                first = 0;
            }
        }

        if (ap_cstr_casecmp(token, "None") == 0) {
            if (action != '*') {
                valid = 0;
            }
            else {
                cfg->etag_bits = bit = ETAG_NONE;
                explicit = 1;
            }
        }
        else if (ap_cstr_casecmp(token, "All") == 0) {
            if (action != '*') {
                valid = 0;
            }
            else {
                explicit = 1;
                cfg->etag_bits = bit = ETAG_ALL;
            }
        }
        else if (ap_cstr_casecmp(token, "Size") == 0) {
            bit = ETAG_SIZE;
        }
        else if ((ap_cstr_casecmp(token, "LMTime") == 0)
                 || (ap_cstr_casecmp(token, "MTime") == 0)
                 || (ap_cstr_casecmp(token, "LastModified") == 0)) {
            bit = ETAG_MTIME;
        }
        else if (ap_cstr_casecmp(token, "INode") == 0) {
            bit = ETAG_INODE;
        }
        else {
            return apr_pstrcat(cmd->pool, "Unknown keyword '",
                               token, "' for ", cmd->cmd->name,
                               " directive", NULL);
        }

        if (! valid) {
            return apr_pstrcat(cmd->pool, cmd->cmd->name, " keyword '",
                               token, "' cannot be used with '+' or '-'",
                               NULL);
        }

        if (action == '+') {
            /*
             * Make sure it's in the 'add' list and absent from the
             * 'subtract' list.
             */
            cfg->etag_add |= bit;
            cfg->etag_remove &= (~ bit);
        }
        else if (action == '-') {
            cfg->etag_remove |= bit;
            cfg->etag_add &= (~ bit);
        }
        else {
            /*
             * Non-relative values wipe out any + or - values
             * accumulated so far.
             */
            cfg->etag_bits |= bit;
            cfg->etag_add = ETAG_UNSET;
            cfg->etag_remove = ETAG_UNSET;
            explicit = 1;
        }
    }

    /*
     * Any setting at all will clear the 'None' and 'Unset' bits.
     */

    if (cfg->etag_add != ETAG_UNSET) {
        cfg->etag_add &= (~ ETAG_UNSET);
    }

    if (cfg->etag_remove != ETAG_UNSET) {
        cfg->etag_remove &= (~ ETAG_UNSET);
    }

    if (explicit) {
        cfg->etag_bits &= (~ ETAG_UNSET);

        if ((cfg->etag_bits & ETAG_NONE) != ETAG_NONE) {
            cfg->etag_bits &= (~ ETAG_NONE);
        }
    }

    return NULL;
}

static const char *set_enable_mmap(cmd_parms *cmd, void *d_,
                                   const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "on") == 0) {
        d->enable_mmap = ENABLE_MMAP_ON;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        d->enable_mmap = ENABLE_MMAP_OFF;
    }
    else {
        return "parameter must be 'on' or 'off'";
    }

    return NULL;
}

static const char *set_enable_sendfile(cmd_parms *cmd, void *d_,
                                   const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "on") == 0) {
        d->enable_sendfile = ENABLE_SENDFILE_ON;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        d->enable_sendfile = ENABLE_SENDFILE_OFF;
    }
    else {
        return "parameter must be 'on' or 'off'";
    }

    return NULL;
}


/*
 * Report a missing-'>' syntax error.
 */
static char *unclosed_directive(cmd_parms *cmd)
{
    return apr_pstrcat(cmd->pool, cmd->cmd->name,
                       "> directive missing closing '>'", NULL);
}

/*
 * Report a missing args in '<Foo >' syntax error.
 */
static char *missing_container_arg(cmd_parms *cmd)
{
    return apr_pstrcat(cmd->pool, cmd->cmd->name,
                       "> directive requires additional arguments", NULL);
}

AP_CORE_DECLARE_NONSTD(const char *) ap_limit_section(cmd_parms *cmd,
                                                      void *dummy,
                                                      const char *arg)
{
    const char *endp = ap_strrchr_c(arg, '>');
    const char *limited_methods;
    void *tog = cmd->cmd->cmd_data;
    apr_int64_t limited = 0;
    apr_int64_t old_limited = cmd->limited;
    const char *errmsg;

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    limited_methods = apr_pstrmemdup(cmd->temp_pool, arg, endp - arg);

    if (!limited_methods[0]) {
        return missing_container_arg(cmd);
    }

    while (limited_methods[0]) {
        char *method = ap_getword_conf(cmd->temp_pool, &limited_methods);
        int methnum;

        /* check for builtin or module registered method number */
        methnum = ap_method_number_of(method);

        if (methnum == M_TRACE && !tog) {
            return "TRACE cannot be controlled by <Limit>, see TraceEnable";
        }
        else if (methnum == M_INVALID) {
            /* method has not been registered yet, but resource restriction
             * is always checked before method handling, so register it.
             */
            methnum = ap_method_register(cmd->pool,
                                         apr_pstrdup(cmd->pool, method));
        }

        limited |= (AP_METHOD_BIT << methnum);
    }

    /* Killing two features with one function,
     * if (tog == NULL) <Limit>, else <LimitExcept>
     */
    limited = tog ? ~limited : limited;

    if (!(old_limited & limited)) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name,
                           "> directive excludes all methods", NULL);
    }
    else if ((old_limited & limited) == old_limited) {
        return apr_pstrcat(cmd->pool, cmd->cmd->name,
                           "> directive specifies methods already excluded",
                           NULL);
    }

    cmd->limited &= limited;

    errmsg = ap_walk_config(cmd->directive->first_child, cmd, cmd->context);

    cmd->limited = old_limited;

    return errmsg;
}

/* XXX: Bogus - need to do this differently (at least OS2/Netware suffer
 * the same problem!!!
 * We use this in <DirectoryMatch> and <FilesMatch>, to ensure that
 * people don't get bitten by wrong-cased regex matches
 */

#ifdef WIN32
#define USE_ICASE AP_REG_ICASE
#else
#define USE_ICASE 0
#endif

static const char *dirsection(cmd_parms *cmd, void *mconfig, const char *arg)
{
    const char *errmsg;
    const char *endp = ap_strrchr_c(arg, '>');
    int old_overrides = cmd->override;
    char *old_path = cmd->path;
    core_dir_config *conf;
    ap_conf_vector_t *new_dir_conf = ap_create_per_dir_config(cmd->pool);
    ap_regex_t *r = NULL;
    const command_rec *thiscmd = cmd->cmd;

    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    cmd->path = ap_getword_conf(cmd->pool, &arg);
    cmd->override = OR_ALL|ACCESS_CONF;

    if (!strcmp(cmd->path, "~")) {
        cmd->path = ap_getword_conf(cmd->pool, &arg);
        if (!cmd->path)
            return "<Directory ~ > block must specify a path";
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED|USE_ICASE);
        if (!r) {
            return "Regex could not be compiled";
        }
    }
    else if (thiscmd->cmd_data) { /* <DirectoryMatch> */
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED|USE_ICASE);
        if (!r) {
            return "Regex could not be compiled";
        }
    }
    else if (strcmp(cmd->path, "/") != 0)
    {
        char *newpath;

        /*
         * Ensure that the pathname is canonical, and append the trailing /
         */
        apr_status_t rv = apr_filepath_merge(&newpath, NULL, cmd->path,
                                             APR_FILEPATH_TRUENAME, cmd->pool);
        if (rv != APR_SUCCESS && rv != APR_EPATHWILD) {
            return apr_pstrcat(cmd->pool, "<Directory \"", cmd->path,
                               "\"> path is invalid.", NULL);
        }

        cmd->path = newpath;
        if (cmd->path[strlen(cmd->path) - 1] != '/')
            cmd->path = apr_pstrcat(cmd->pool, cmd->path, "/", NULL);
    }

    /* initialize our config and fetch it */
    conf = ap_set_config_vectors(cmd->server, new_dir_conf, cmd->path,
                                 &core_module, cmd->pool);

    errmsg = ap_walk_config(cmd->directive->first_child, cmd, new_dir_conf);
    if (errmsg != NULL)
        return errmsg;

    conf->r = r;
    conf->d = cmd->path;
    conf->d_is_fnmatch = (apr_fnmatch_test(conf->d) != 0);

    if (r) {
        conf->refs = apr_array_make(cmd->pool, 8, sizeof(char *));
        ap_regname(r, conf->refs, AP_REG_MATCH, 1);
    }

    /* Make this explicit - the "/" root has 0 elements, that is, we
     * will always merge it, and it will always sort and merge first.
     * All others are sorted and tested by the number of slashes.
     */
    if (strcmp(conf->d, "/") == 0)
        conf->d_components = 0;
    else
        conf->d_components = ap_count_dirs(conf->d);

    ap_add_per_dir_conf(cmd->server, new_dir_conf);

    if (*arg != '\0') {
        return apr_pstrcat(cmd->pool, "Multiple ", thiscmd->name,
                           "> arguments not (yet) supported.", NULL);
    }

    cmd->path = old_path;
    cmd->override = old_overrides;

    return NULL;
}

static const char *urlsection(cmd_parms *cmd, void *mconfig, const char *arg)
{
    const char *errmsg;
    const char *endp = ap_strrchr_c(arg, '>');
    int old_overrides = cmd->override;
    char *old_path = cmd->path;
    core_dir_config *conf;
    ap_regex_t *r = NULL;
    const command_rec *thiscmd = cmd->cmd;
    ap_conf_vector_t *new_url_conf = ap_create_per_dir_config(cmd->pool);
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    cmd->path = ap_getword_conf(cmd->pool, &arg);
    cmd->override = OR_ALL|ACCESS_CONF;

    if (thiscmd->cmd_data) { /* <LocationMatch> */
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED);
        if (!r) {
            return "Regex could not be compiled";
        }
    }
    else if (!strcmp(cmd->path, "~")) {
        cmd->path = ap_getword_conf(cmd->pool, &arg);
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED);
        if (!r) {
            return "Regex could not be compiled";
        }
    }

    /* initialize our config and fetch it */
    conf = ap_set_config_vectors(cmd->server, new_url_conf, cmd->path,
                                 &core_module, cmd->pool);

    errmsg = ap_walk_config(cmd->directive->first_child, cmd, new_url_conf);
    if (errmsg != NULL)
        return errmsg;

    conf->d = apr_pstrdup(cmd->pool, cmd->path);     /* No mangling, please */
    conf->d_is_fnmatch = apr_fnmatch_test(conf->d) != 0;
    conf->r = r;

    if (r) {
        conf->refs = apr_array_make(cmd->pool, 8, sizeof(char *));
        ap_regname(r, conf->refs, AP_REG_MATCH, 1);
    }

    ap_add_per_url_conf(cmd->server, new_url_conf);

    if (*arg != '\0') {
        return apr_pstrcat(cmd->pool, "Multiple ", thiscmd->name,
                           "> arguments not (yet) supported.", NULL);
    }

    cmd->path = old_path;
    cmd->override = old_overrides;

    return NULL;
}

static const char *filesection(cmd_parms *cmd, void *mconfig, const char *arg)
{
    const char *errmsg;
    const char *endp = ap_strrchr_c(arg, '>');
    int old_overrides = cmd->override;
    char *old_path = cmd->path;
    core_dir_config *conf;
    ap_regex_t *r = NULL;
    const command_rec *thiscmd = cmd->cmd;
    ap_conf_vector_t *new_file_conf = ap_create_per_dir_config(cmd->pool);
    const char *err = ap_check_cmd_context(cmd,
                                           NOT_IN_LOCATION | NOT_IN_LIMIT);

    if (err != NULL) {
        return err;
    }

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    cmd->path = ap_getword_conf(cmd->pool, &arg);
    /* Only if not an .htaccess file */
    if (!old_path) {
        cmd->override = OR_ALL|ACCESS_CONF;
    }

    if (thiscmd->cmd_data) { /* <FilesMatch> */
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED|USE_ICASE);
        if (!r) {
            return "Regex could not be compiled";
        }
    }
    else if (!strcmp(cmd->path, "~")) {
        cmd->path = ap_getword_conf(cmd->pool, &arg);
        r = ap_pregcomp(cmd->pool, cmd->path, AP_REG_EXTENDED|USE_ICASE);
        if (!r) {
            return "Regex could not be compiled";
        }
    }
    else {
        char *newpath;
        /* Ensure that the pathname is canonical, but we
         * can't test the case/aliases without a fixed path */
        if (apr_filepath_merge(&newpath, "", cmd->path,
                               0, cmd->pool) != APR_SUCCESS)
                return apr_pstrcat(cmd->pool, "<Files \"", cmd->path,
                               "\"> is invalid.", NULL);
        cmd->path = newpath;
    }

    /* initialize our config and fetch it */
    conf = ap_set_config_vectors(cmd->server, new_file_conf, cmd->path,
                                 &core_module, cmd->pool);

    errmsg = ap_walk_config(cmd->directive->first_child, cmd, new_file_conf);
    if (errmsg != NULL)
        return errmsg;

    conf->d = cmd->path;
    conf->d_is_fnmatch = apr_fnmatch_test(conf->d) != 0;
    conf->r = r;

    if (r) {
        conf->refs = apr_array_make(cmd->pool, 8, sizeof(char *));
        ap_regname(r, conf->refs, AP_REG_MATCH, 1);
    }

    ap_add_file_conf(cmd->pool, (core_dir_config *)mconfig, new_file_conf);

    if (*arg != '\0') {
        return apr_pstrcat(cmd->pool, "Multiple ", thiscmd->name,
                           "> arguments not (yet) supported.", NULL);
    }

    cmd->path = old_path;
    cmd->override = old_overrides;

    return NULL;
}

#define COND_IF      ((void *)1)
#define COND_ELSE    ((void *)2)
#define COND_ELSEIF  ((void *)3)

static const char *ifsection(cmd_parms *cmd, void *mconfig, const char *arg)
{
    const char *errmsg;
    const char *endp = ap_strrchr_c(arg, '>');
    int old_overrides = cmd->override;
    char *old_path = cmd->path;
    core_dir_config *conf;
    const command_rec *thiscmd = cmd->cmd;
    ap_conf_vector_t *new_if_conf = ap_create_per_dir_config(cmd->pool);
    const char *err = ap_check_cmd_context(cmd, NOT_IN_LIMIT);
    const char *condition;
    const char *expr_err;

    if (err != NULL) {
        return err;
    }

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    /*
     * Set a dummy value so that other directives notice that they are inside
     * a config section.
     */
    cmd->path = "*If";
    /* Only if not an .htaccess file */
    if (!old_path) {
        cmd->override = OR_ALL|ACCESS_CONF;
    }

    /* initialize our config and fetch it */
    conf = ap_set_config_vectors(cmd->server, new_if_conf, cmd->path,
                                 &core_module, cmd->pool);

    if (cmd->cmd->cmd_data == COND_IF)
        conf->condition_ifelse = AP_CONDITION_IF;
    else if (cmd->cmd->cmd_data == COND_ELSEIF)
        conf->condition_ifelse = AP_CONDITION_ELSEIF;
    else if (cmd->cmd->cmd_data == COND_ELSE)
        conf->condition_ifelse = AP_CONDITION_ELSE;
    else
        ap_assert(0);

    if (conf->condition_ifelse == AP_CONDITION_ELSE) {
        if (arg[0])
            return "<Else> does not take an argument";
    }
    else {
        if (!arg[0])
            return missing_container_arg(cmd);
        condition = ap_getword_conf(cmd->pool, &arg);
        conf->condition = ap_expr_parse_cmd(cmd, condition, 0, &expr_err, NULL);
        if (expr_err)
            return apr_psprintf(cmd->pool, "Cannot parse condition clause: %s",
                                expr_err);
    }

    errmsg = ap_walk_config(cmd->directive->first_child, cmd, new_if_conf);
    if (errmsg != NULL)
        return errmsg;

    conf->d = cmd->path;
    conf->d_is_fnmatch = 0;
    conf->r = NULL;

    errmsg = ap_add_if_conf(cmd->pool, (core_dir_config *)mconfig, new_if_conf);
    if (errmsg != NULL)
        return errmsg;

    if (*arg != '\0') {
        return apr_pstrcat(cmd->pool, "Multiple ", thiscmd->name,
                           "> arguments not supported.", NULL);
    }

    cmd->path = old_path;
    cmd->override = old_overrides;

    return NULL;
}

static module *find_module(server_rec *s, const char *name)
{
    module *found = ap_find_linked_module(name);

    /* search prelinked stuff */
    if (!found) {
        ap_module_symbol_t *current = ap_prelinked_module_symbols;

        for (; current->name; ++current) {
            if (!strcmp(current->name, name)) {
                found = current->modp;
                break;
            }
        }
    }

    /* search dynamic stuff */
    if (!found) {
        APR_OPTIONAL_FN_TYPE(ap_find_loaded_module_symbol) *check_symbol =
            APR_RETRIEVE_OPTIONAL_FN(ap_find_loaded_module_symbol);

        if (check_symbol) {
            /*
             * There are two phases where calling ap_find_loaded_module_symbol
             * is problematic:
             *
             * During reading of the config, ap_server_conf is invalid but s
             * points to the main server config, if passed from cmd->server
             * of an EXEC_ON_READ directive.
             *
             * During config parsing, s may be a virtual host that would cause
             * a segfault in mod_so if passed to ap_find_loaded_module_symbol,
             * because mod_so's server config for vhosts is initialized later.
             * But ap_server_conf is already set at this time.
             *
             * Therefore we use s if it is not virtual and ap_server_conf if
             * s is virtual.
             */
            found = check_symbol(s->is_virtual ? ap_server_conf : s, name);
        }
    }

    return found;
}


static const char *start_ifmod(cmd_parms *cmd, void *mconfig, const char *arg)
{
    const char *endp = ap_strrchr_c(arg, '>');
    int not = (arg[0] == '!');
    module *found;

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (not) {
        arg++;
    }

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    found = find_module(cmd->server, arg);

    if ((!not && found) || (not && !found)) {
        ap_directive_t *parent = NULL;
        ap_directive_t *current = NULL;
        const char *retval;

        retval = ap_build_cont_config(cmd->pool, cmd->temp_pool, cmd,
                                      &current, &parent, "<IfModule");
        *(ap_directive_t **)mconfig = current;
        return retval;
    }
    else {
        *(ap_directive_t **)mconfig = NULL;
        return ap_soak_end_container(cmd, "<IfModule");
    }
}

AP_DECLARE(int) ap_exists_config_define(const char *name)
{
    return ap_array_str_contains(ap_server_config_defines, name);
}

static const char *start_ifdefine(cmd_parms *cmd, void *dummy, const char *arg)
{
    const char *endp;
    int defined;
    int not = 0;

    endp = ap_strrchr_c(arg, '>');
    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (arg[0] == '!') {
        not = 1;
        arg++;
    }

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    defined = ap_exists_config_define(arg);
    if ((!not && defined) || (not && !defined)) {
        ap_directive_t *parent = NULL;
        ap_directive_t *current = NULL;
        const char *retval;

        retval = ap_build_cont_config(cmd->pool, cmd->temp_pool, cmd,
                                      &current, &parent, "<IfDefine");
        *(ap_directive_t **)dummy = current;
        return retval;
    }
    else {
        *(ap_directive_t **)dummy = NULL;
        return ap_soak_end_container(cmd, "<IfDefine");
    }
}

/* httpd.conf commands... beginning with the <VirtualHost> business */

static const char *virtualhost_section(cmd_parms *cmd, void *dummy,
                                       const char *arg)
{
    server_rec *main_server = cmd->server, *s;
    const char *errmsg;
    const char *endp = ap_strrchr_c(arg, '>');
    apr_pool_t *p = cmd->pool;

    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    if (endp == NULL) {
        return unclosed_directive(cmd);
    }

    arg = apr_pstrndup(cmd->temp_pool, arg, endp - arg);

    if (!arg[0]) {
        return missing_container_arg(cmd);
    }

    /* FIXME: There's another feature waiting to happen here -- since you
        can now put multiple addresses/names on a single <VirtualHost>
        you might want to use it to group common definitions and then
        define other "subhosts" with their individual differences.  But
        personally I'd rather just do it with a macro preprocessor. -djg */
    if (main_server->is_virtual) {
        return "<VirtualHost> doesn't nest!";
    }

    errmsg = ap_init_virtual_host(p, arg, main_server, &s);
    if (errmsg) {
        return errmsg;
    }

    s->next = main_server->next;
    main_server->next = s;

    s->defn_name = cmd->directive->filename;
    s->defn_line_number = cmd->directive->line_num;

    cmd->server = s;

    errmsg = ap_walk_config(cmd->directive->first_child, cmd,
                            s->lookup_defaults);

    cmd->server = main_server;

    return errmsg;
}

static const char *set_server_alias(cmd_parms *cmd, void *dummy,
                                    const char *arg)
{
    if (!cmd->server->names) {
        return "ServerAlias only used in <VirtualHost>";
    }

    while (*arg) {
        char **item, *name = ap_getword_conf(cmd->pool, &arg);

        if (ap_is_matchexp(name)) {
            item = (char **)apr_array_push(cmd->server->wild_names);
        }
        else {
            item = (char **)apr_array_push(cmd->server->names);
        }

        *item = name;
    }

    return NULL;
}

static const char *set_accf_map(cmd_parms *cmd, void *dummy,
                                const char *iproto, const char* iaccf)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);
    char* proto;
    char* accf;
    if (err != NULL) {
        return err;
    }

    proto = apr_pstrdup(cmd->pool, iproto);
    ap_str_tolower(proto);
    accf = apr_pstrdup(cmd->pool, iaccf);
    ap_str_tolower(accf);
    apr_table_setn(conf->accf_map, proto, accf);

    return NULL;
}

AP_DECLARE(const char*) ap_get_server_protocol(server_rec* s)
{
    core_server_config *conf = ap_get_core_module_config(s->module_config);
    return conf->protocol;
}

AP_DECLARE(void) ap_set_server_protocol(server_rec* s, const char* proto)
{
    core_server_config *conf = ap_get_core_module_config(s->module_config);
    conf->protocol = proto;
}

static const char *set_protocol(cmd_parms *cmd, void *dummy,
                                const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);
    char* proto;

    if (err != NULL) {
        return err;
    }

    proto = apr_pstrdup(cmd->pool, arg);
    ap_str_tolower(proto);
    conf->protocol = proto;

    return NULL;
}

static const char *set_server_string_slot(cmd_parms *cmd, void *dummy,
                                          const char *arg)
{
    /* This one's pretty generic... */

    int offset = (int)(long)cmd->info;
    char *struct_ptr = (char *)cmd->server;

    const char *err = ap_check_cmd_context(cmd,
                                           NOT_IN_DIR_LOC_FILE);
    if (err != NULL) {
        return err;
    }

    *(const char **)(struct_ptr + offset) = arg;
    return NULL;
}

/*
 * The ServerName directive takes one argument with format
 * [scheme://]fully-qualified-domain-name[:port], for instance
 * ServerName www.example.com
 * ServerName www.example.com:80
 * ServerName https://www.example.com:443
 */

static const char *server_hostname_port(cmd_parms *cmd, void *dummy, const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    const char *portstr, *part;
    char *scheme;
    int port;

    if (err != NULL) {
        return err;
    }

    if (apr_fnmatch_test(arg))
        return apr_pstrcat(cmd->temp_pool, "Invalid ServerName \"", arg,
                "\" use ServerAlias to set multiple server names.", NULL);

    part = ap_strstr_c(arg, "://");

    if (part) {
      scheme = apr_pstrndup(cmd->pool, arg, part - arg);
      ap_str_tolower(scheme);
      cmd->server->server_scheme = (const char *)scheme;
      part += 3;
    } else {
      part = arg;
    }

    portstr = ap_strchr_c(part, ':');
    if (portstr) {
        cmd->server->server_hostname = apr_pstrndup(cmd->pool, part,
                                                    portstr - part);
        portstr++;
        port = atoi(portstr);
        if (port <= 0 || port >= 65536) { /* 65536 == 1<<16 */
            return apr_pstrcat(cmd->temp_pool, "The port number \"", arg,
                          "\" is outside the appropriate range "
                          "(i.e., 1..65535).", NULL);
        }
    }
    else {
        cmd->server->server_hostname = apr_pstrdup(cmd->pool, part);
        port = 0;
    }

    cmd->server->port = port;
    return NULL;
}

static const char *set_signature_flag(cmd_parms *cmd, void *d_,
                                      const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "On") == 0) {
        d->server_signature = srv_sig_on;
    }
    else if (ap_cstr_casecmp(arg, "Off") == 0) {
        d->server_signature = srv_sig_off;
    }
    else if (ap_cstr_casecmp(arg, "EMail") == 0) {
        d->server_signature = srv_sig_withmail;
    }
    else {
        return "ServerSignature: use one of: off | on | email";
    }

    return NULL;
}

static const char *set_server_root(cmd_parms *cmd, void *dummy,
                                   const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);

    if (err != NULL) {
        return err;
    }

    if ((apr_filepath_merge((char**)&ap_server_root, NULL, arg,
                            APR_FILEPATH_TRUENAME, cmd->pool) != APR_SUCCESS)
        || !ap_is_directory(cmd->temp_pool, ap_server_root)) {
        return "ServerRoot must be a valid directory";
    }

    return NULL;
}

static const char *set_runtime_dir(cmd_parms *cmd, void *dummy, const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);

    if (err != NULL) {
        return err;
    }

    if ((apr_filepath_merge((char**)&ap_runtime_dir, NULL,
                            ap_server_root_relative(cmd->temp_pool, arg),
                            APR_FILEPATH_TRUENAME, cmd->pool) != APR_SUCCESS)
        || !ap_is_directory(cmd->temp_pool, ap_runtime_dir)) {
        return "DefaultRuntimeDir must be a valid directory, absolute or relative to ServerRoot";
    }

    return NULL;
}

static const char *set_timeout(cmd_parms *cmd, void *dummy, const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);

    if (err != NULL) {
        return err;
    }

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

static const char *set_allow2f(cmd_parms *cmd, void *d_, const char *arg)
{
    core_dir_config *d = d_;

    if (0 == ap_cstr_casecmp(arg, "on")) {
        d->allow_encoded_slashes = 1;
        d->decode_encoded_slashes = 1; /* for compatibility with 2.0 & 2.2 */
    } else if (0 == ap_cstr_casecmp(arg, "off")) {
        d->allow_encoded_slashes = 0;
        d->decode_encoded_slashes = 0;
    } else if (0 == ap_cstr_casecmp(arg, "nodecode")) {
        d->allow_encoded_slashes = 1;
        d->decode_encoded_slashes = 0;
    } else {
        return apr_pstrcat(cmd->pool,
                           cmd->cmd->name, " must be On, Off, or NoDecode",
                           NULL);
    }

    d->allow_encoded_slashes_set = 1;
    d->decode_encoded_slashes_set = 1;

    return NULL;
}

static const char *set_hostname_lookups(cmd_parms *cmd, void *d_,
                                        const char *arg)
{
    core_dir_config *d = d_;

    if (!ap_cstr_casecmp(arg, "on")) {
        d->hostname_lookups = HOSTNAME_LOOKUP_ON;
    }
    else if (!ap_cstr_casecmp(arg, "off")) {
        d->hostname_lookups = HOSTNAME_LOOKUP_OFF;
    }
    else if (!ap_cstr_casecmp(arg, "double")) {
        d->hostname_lookups = HOSTNAME_LOOKUP_DOUBLE;
    }
    else {
        return "parameter must be 'on', 'off', or 'double'";
    }

    return NULL;
}

static const char *set_serverpath(cmd_parms *cmd, void *dummy,
                                  const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);

    if (err != NULL) {
        return err;
    }

    cmd->server->path = arg;
    cmd->server->pathlen = (int)strlen(arg);
    return NULL;
}

static const char *set_content_md5(cmd_parms *cmd, void *d_, int arg)
{
    core_dir_config *d = d_;

    d->content_md5 = arg ? AP_CONTENT_MD5_ON : AP_CONTENT_MD5_OFF;
    return NULL;
}

static const char *set_accept_path_info(cmd_parms *cmd, void *d_, const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "on") == 0) {
        d->accept_path_info = AP_REQ_ACCEPT_PATH_INFO;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        d->accept_path_info = AP_REQ_REJECT_PATH_INFO;
    }
    else if (ap_cstr_casecmp(arg, "default") == 0) {
        d->accept_path_info = AP_REQ_DEFAULT_PATH_INFO;
    }
    else {
        return "AcceptPathInfo must be set to on, off or default";
    }

    return NULL;
}

static const char *set_use_canonical_name(cmd_parms *cmd, void *d_,
                                          const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "on") == 0) {
        d->use_canonical_name = USE_CANONICAL_NAME_ON;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        d->use_canonical_name = USE_CANONICAL_NAME_OFF;
    }
    else if (ap_cstr_casecmp(arg, "dns") == 0) {
        d->use_canonical_name = USE_CANONICAL_NAME_DNS;
    }
    else {
        return "parameter must be 'on', 'off', or 'dns'";
    }

    return NULL;
}

static const char *set_use_canonical_phys_port(cmd_parms *cmd, void *d_,
                                          const char *arg)
{
    core_dir_config *d = d_;

    if (ap_cstr_casecmp(arg, "on") == 0) {
        d->use_canonical_phys_port = USE_CANONICAL_PHYS_PORT_ON;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        d->use_canonical_phys_port = USE_CANONICAL_PHYS_PORT_OFF;
    }
    else {
        return "parameter must be 'on' or 'off'";
    }

    return NULL;
}

static const char *include_config (cmd_parms *cmd, void *dummy,
                                   const char *name)
{
    ap_directive_t *conftree = NULL;
    const char *conffile, *error;
    unsigned *recursion;
    int optional = cmd->cmd->cmd_data ? 1 : 0;
    void *data;

    /* NOTE: ap_include_sentinel is also used by ap_process_resource_config()
     * during DUMP_INCLUDES; don't change its type or remove it without updating
     * the other.
     */
    apr_pool_userdata_get(&data, "ap_include_sentinel", cmd->pool);
    if (data) {
        recursion = data;
    }
    else {
        data = recursion = apr_palloc(cmd->pool, sizeof(*recursion));
        *recursion = 0;
        apr_pool_userdata_setn(data, "ap_include_sentinel", NULL, cmd->pool);
    }

    if (++*recursion > AP_MAX_INCLUDE_DEPTH) {
        *recursion = 0;
        return apr_psprintf(cmd->pool, "Exceeded maximum include depth of %u, "
                            "There appears to be a recursion.",
                            AP_MAX_INCLUDE_DEPTH);
    }

    conffile = ap_server_root_relative(cmd->pool, name);
    if (!conffile) {
        *recursion = 0;
        return apr_pstrcat(cmd->pool, "Invalid Include path ",
                           name, NULL);
    }

    if (ap_exists_config_define("DUMP_INCLUDES")) {
        unsigned *line_number;

        /* NOTE: ap_include_lineno is used by ap_process_resource_config()
         * during DUMP_INCLUDES; don't change its type or remove it without
         * updating the other.
         */
        apr_pool_userdata_get(&data, "ap_include_lineno", cmd->pool);
        if (data) {
            line_number = data;
        } else {
            data = line_number = apr_palloc(cmd->pool, sizeof(*line_number));
            apr_pool_userdata_setn(data, "ap_include_lineno", NULL, cmd->pool);
        }

        *line_number = cmd->config_file->line_number;
    }

    error = ap_process_fnmatch_configs(cmd->server, conffile, &conftree,
                                       cmd->pool, cmd->temp_pool,
                                       optional);
    if (error) {
        *recursion = 0;
        return error;
    }

    *(ap_directive_t **)dummy = conftree;

    /* recursion level done */
    if (*recursion) {
        --*recursion;
    }

    return NULL;
}

static const char *update_loglevel(cmd_parms *cmd, struct ap_logconf *log,
                                   const char *arg)
{
    const char *level_str, *err;
    module *module;
    int level;

    level_str = ap_strrchr_c(arg, ':');

    if (level_str == NULL) {
        err = ap_parse_log_level(arg, &log->level);
        if (err != NULL)
            return err;
        ap_reset_module_loglevels(log, APLOG_NO_MODULE);
        ap_log_error(APLOG_MARK, APLOG_TRACE3, 0, cmd->server,
                     "Setting %s for all modules to %s", cmd->cmd->name, arg);
        return NULL;
    }

    arg = apr_pstrmemdup(cmd->temp_pool, arg, level_str - arg);
    level_str++;
    if (!*level_str) {
        return apr_psprintf(cmd->temp_pool, "Module specifier '%s' must be "
                            "followed by a log level keyword", arg);
    }

    err = ap_parse_log_level(level_str, &level);
    if (err != NULL)
        return apr_psprintf(cmd->temp_pool, "%s:%s: %s", arg, level_str, err);

    if ((module = find_module(cmd->server, arg)) == NULL) {
        char *name = apr_psprintf(cmd->temp_pool, "%s_module", arg);
        ap_log_error(APLOG_MARK, APLOG_TRACE6, 0, cmd->server,
                     "Cannot find module '%s', trying '%s'", arg, name);
        module = find_module(cmd->server, name);
    }

    if (module == NULL) {
        return apr_psprintf(cmd->temp_pool, "Cannot find module %s", arg);
    }

    ap_set_module_loglevel(cmd->pool, log, module->module_index, level);
    ap_log_error(APLOG_MARK, APLOG_TRACE3, 0, cmd->server,
                 "Setting %s for module %s to %s", cmd->cmd->name,
                 module->name, level_str);

    return NULL;
}

static const char *set_loglevel(cmd_parms *cmd, void *config_, const char *arg)
{
    struct ap_logconf *log;

    if (cmd->path) {
        core_dir_config *dconf = config_;
        if (!dconf->log) {
            dconf->log = ap_new_log_config(cmd->pool, NULL);
        }
        log = dconf->log;
    }
    else {
        log = &cmd->server->log;
    }

    if (arg == NULL)
        return "LogLevel requires level keyword or module loglevel specifier";

    return update_loglevel(cmd, log, arg);
}

static const char *set_loglevel_override(cmd_parms *cmd, void *d_, int argc,
                                         char *const argv[])
{
    core_server_config *sconf;
    conn_log_config *entry;
    int ret, i;
    const char *addr, *mask, *err;

    if (argc < 2)
        return "LogLevelOverride requires at least two arguments";

    entry = apr_pcalloc(cmd->pool, sizeof(conn_log_config));
    sconf = ap_get_core_module_config(cmd->server->module_config);
    if (!sconf->conn_log_level)
        sconf->conn_log_level = apr_array_make(cmd->pool, 4, sizeof(entry));
    APR_ARRAY_PUSH(sconf->conn_log_level, conn_log_config *) = entry;

    addr = argv[0];
    mask = ap_strchr_c(addr, '/');
    if (mask) {
        addr = apr_pstrmemdup(cmd->temp_pool, addr, mask - addr);
        mask++;
    }
    ret = apr_ipsubnet_create(&entry->subnet, addr, mask, cmd->pool);
    if (ret != APR_SUCCESS)
        return "parsing of subnet/netmask failed";

    for (i = 1; i < argc; i++) {
        if ((err = update_loglevel(cmd, &entry->log, argv[i])) != NULL)
            return err;
    }
    return NULL;
}

AP_DECLARE(const char *) ap_psignature(const char *prefix, request_rec *r)
{
    char sport[20];
    core_dir_config *conf;

    conf = (core_dir_config *)ap_get_core_module_config(r->per_dir_config);
    if ((conf->server_signature == srv_sig_off)
            || (conf->server_signature == srv_sig_unset)) {
        return "";
    }

    apr_snprintf(sport, sizeof sport, "%u", (unsigned) ap_get_server_port(r));

    if (conf->server_signature == srv_sig_withmail) {
        return apr_pstrcat(r->pool, prefix, "<address>",
                           ap_get_server_banner(),
                           " Server at <a href=\"",
                           ap_is_url(r->server->server_admin) ? "" : "mailto:",
                           ap_escape_html(r->pool, r->server->server_admin),
                           "\">",
                           ap_escape_html(r->pool, ap_get_server_name(r)),
                           "</a> Port ", sport,
                           "</address>\n", NULL);
    }

    return apr_pstrcat(r->pool, prefix, "<address>", ap_get_server_banner(),
                       " Server at ",
                       ap_escape_html(r->pool, ap_get_server_name(r)),
                       " Port ", sport,
                       "</address>\n", NULL);
}

/*
 * Handle a request to include the server's OS platform in the Server
 * response header field (the ServerTokens directive).  Unfortunately
 * this requires a new global in order to communicate the setting back to
 * http_main so it can insert the information in the right place in the
 * string.
 */

static char *server_banner = NULL;
static int banner_locked = 0;
static const char *server_description = NULL;

enum server_token_type {
    SrvTk_MAJOR,         /* eg: Apache/2 */
    SrvTk_MINOR,         /* eg. Apache/2.0 */
    SrvTk_MINIMAL,       /* eg: Apache/2.0.41 */
    SrvTk_OS,            /* eg: Apache/2.0.41 (UNIX) */
    SrvTk_FULL,          /* eg: Apache/2.0.41 (UNIX) PHP/4.2.2 FooBar/1.2b */
    SrvTk_PRODUCT_ONLY   /* eg: Apache */
};
static enum server_token_type ap_server_tokens = SrvTk_FULL;

static apr_status_t reset_banner(void *dummy)
{
    banner_locked = 0;
    ap_server_tokens = SrvTk_FULL;
    server_banner = NULL;
    server_description = NULL;
    return APR_SUCCESS;
}

AP_DECLARE(void) ap_get_server_revision(ap_version_t *version)
{
    version->major = AP_SERVER_MAJORVERSION_NUMBER;
    version->minor = AP_SERVER_MINORVERSION_NUMBER;
    version->patch = AP_SERVER_PATCHLEVEL_NUMBER;
    version->add_string = AP_SERVER_ADD_STRING;
}

AP_DECLARE(const char *) ap_get_server_description(void)
{
    return server_description ? server_description :
        AP_SERVER_BASEVERSION " (" PLATFORM ")";
}

AP_DECLARE(const char *) ap_get_server_banner(void)
{
    return server_banner ? server_banner : AP_SERVER_BASEVERSION;
}

AP_DECLARE(void) ap_add_version_component(apr_pool_t *pconf, const char *component)
{
    if (! banner_locked) {
        /*
         * If the version string is null, register our cleanup to reset the
         * pointer on pool destruction. We also know that, if NULL,
         * we are adding the original SERVER_BASEVERSION string.
         */
        if (server_banner == NULL) {
            apr_pool_cleanup_register(pconf, NULL, reset_banner,
                                      apr_pool_cleanup_null);
            server_banner = apr_pstrdup(pconf, component);
        }
        else {
            /*
             * Tack the given component identifier to the end of
             * the existing string.
             */
            server_banner = apr_pstrcat(pconf, server_banner, " ",
                                        component, NULL);
        }
    }
    server_description = apr_pstrcat(pconf, server_description, " ",
                                     component, NULL);
}

/*
 * This routine adds the real server base identity to the banner string,
 * and then locks out changes until the next reconfig.
 */
static void set_banner(apr_pool_t *pconf)
{
    if (ap_server_tokens == SrvTk_PRODUCT_ONLY) {
        ap_add_version_component(pconf, AP_SERVER_BASEPRODUCT);
    }
    else if (ap_server_tokens == SrvTk_MINIMAL) {
        ap_add_version_component(pconf, AP_SERVER_BASEVERSION);
    }
    else if (ap_server_tokens == SrvTk_MINOR) {
        ap_add_version_component(pconf, AP_SERVER_BASEPRODUCT "/" AP_SERVER_MINORREVISION);
    }
    else if (ap_server_tokens == SrvTk_MAJOR) {
        ap_add_version_component(pconf, AP_SERVER_BASEPRODUCT "/" AP_SERVER_MAJORVERSION);
    }
    else {
        ap_add_version_component(pconf, AP_SERVER_BASEVERSION " (" PLATFORM ")");
    }

    /*
     * Lock the server_banner string if we're not displaying
     * the full set of tokens
     */
    if (ap_server_tokens != SrvTk_FULL) {
        banner_locked++;
    }
    server_description = AP_SERVER_BASEVERSION " (" PLATFORM ")";
}

static const char *set_serv_tokens(cmd_parms *cmd, void *dummy,
                                   const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);

    if (err != NULL) {
        return err;
    }

    if (!ap_cstr_casecmp(arg, "OS")) {
        ap_server_tokens = SrvTk_OS;
    }
    else if (!ap_cstr_casecmp(arg, "Min") || !ap_cstr_casecmp(arg, "Minimal")) {
        ap_server_tokens = SrvTk_MINIMAL;
    }
    else if (!ap_cstr_casecmp(arg, "Major")) {
        ap_server_tokens = SrvTk_MAJOR;
    }
    else if (!ap_cstr_casecmp(arg, "Minor") ) {
        ap_server_tokens = SrvTk_MINOR;
    }
    else if (!ap_cstr_casecmp(arg, "Prod") || !ap_cstr_casecmp(arg, "ProductOnly")) {
        ap_server_tokens = SrvTk_PRODUCT_ONLY;
    }
    else if (!ap_cstr_casecmp(arg, "Full")) {
        ap_server_tokens = SrvTk_FULL;
    }
    else {
        return "ServerTokens takes 1 argument: 'Prod(uctOnly)', 'Major', 'Minor', 'Min(imal)', 'OS', or 'Full'";
    }

    return NULL;
}

static const char *set_limit_req_line(cmd_parms *cmd, void *dummy,
                                      const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    int lim;

    if (err != NULL) {
        return err;
    }

    lim = atoi(arg);
    if (lim < 0) {
        return apr_pstrcat(cmd->temp_pool, "LimitRequestLine \"", arg,
                           "\" must be a non-negative integer", NULL);
    }

    cmd->server->limit_req_line = lim;
    return NULL;
}

static const char *set_limit_req_fieldsize(cmd_parms *cmd, void *dummy,
                                           const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    int lim;

    if (err != NULL) {
        return err;
    }

    lim = atoi(arg);
    if (lim < 0) {
        return apr_pstrcat(cmd->temp_pool, "LimitRequestFieldsize \"", arg,
                          "\" must be a non-negative integer",
                          NULL);
    }

    cmd->server->limit_req_fieldsize = lim;
    return NULL;
}

static const char *set_limit_req_fields(cmd_parms *cmd, void *dummy,
                                        const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    int lim;

    if (err != NULL) {
        return err;
    }

    lim = atoi(arg);
    if (lim < 0) {
        return apr_pstrcat(cmd->temp_pool, "LimitRequestFields \"", arg,
                           "\" must be a non-negative integer (0 = no limit)",
                           NULL);
    }

    cmd->server->limit_req_fields = lim;
    return NULL;
}

static const char *set_limit_req_body(cmd_parms *cmd, void *conf_,
                                      const char *arg)
{
    core_dir_config *conf = conf_;
    char *errp;

    if (APR_SUCCESS != apr_strtoff(&conf->limit_req_body, arg, &errp, 10)) {
        return "LimitRequestBody argument is not parsable.";
    }
    if (*errp || conf->limit_req_body < 0) {
        return "LimitRequestBody requires a non-negative integer.";
    }

    return NULL;
}

static const char *set_limit_xml_req_body(cmd_parms *cmd, void *conf_,
                                          const char *arg)
{
    core_dir_config *conf = conf_;

    conf->limit_xml_body = atol(arg);
    if (conf->limit_xml_body < 0)
        return "LimitXMLRequestBody requires a non-negative integer.";

    return NULL;
}

static const char *set_max_ranges(cmd_parms *cmd, void *conf_, const char *arg)
{
    core_dir_config *conf = conf_;
    int val = 0;

    if (!ap_cstr_casecmp(arg, "none")) {
        val = AP_MAXRANGES_NORANGES;
    }
    else if (!ap_cstr_casecmp(arg, "default")) {
        val = AP_MAXRANGES_DEFAULT;
    }
    else if (!ap_cstr_casecmp(arg, "unlimited")) {
        val = AP_MAXRANGES_UNLIMITED;
    }
    else {
        val = atoi(arg);
        if (val <= 0)
            return "MaxRanges requires 'none', 'default', 'unlimited' or "
                   "a positive integer";
    }

    conf->max_ranges = val;

    return NULL;
}

static const char *set_max_overlaps(cmd_parms *cmd, void *conf_, const char *arg)
{
    core_dir_config *conf = conf_;
    int val = 0;

    if (!ap_cstr_casecmp(arg, "none")) {
        val = AP_MAXRANGES_NORANGES;
    }
    else if (!ap_cstr_casecmp(arg, "default")) {
        val = AP_MAXRANGES_DEFAULT;
    }
    else if (!ap_cstr_casecmp(arg, "unlimited")) {
        val = AP_MAXRANGES_UNLIMITED;
    }
    else {
        val = atoi(arg);
        if (val <= 0)
            return "MaxRangeOverlaps requires 'none', 'default', 'unlimited' or "
            "a positive integer";
    }

    conf->max_overlaps = val;

    return NULL;
}

static const char *set_max_reversals(cmd_parms *cmd, void *conf_, const char *arg)
{
    core_dir_config *conf = conf_;
    int val = 0;

    if (!ap_cstr_casecmp(arg, "none")) {
        val = AP_MAXRANGES_NORANGES;
    }
    else if (!ap_cstr_casecmp(arg, "default")) {
        val = AP_MAXRANGES_DEFAULT;
    }
    else if (!ap_cstr_casecmp(arg, "unlimited")) {
        val = AP_MAXRANGES_UNLIMITED;
    }
    else {
        val = atoi(arg);
        if (val <= 0)
            return "MaxRangeReversals requires 'none', 'default', 'unlimited' or "
            "a positive integer";
    }

    conf->max_reversals = val;

    return NULL;
}

AP_DECLARE(apr_size_t) ap_get_limit_xml_body(const request_rec *r)
{
    core_dir_config *conf;

    conf = ap_get_core_module_config(r->per_dir_config);
    if (conf->limit_xml_body == AP_LIMIT_UNSET)
        return AP_DEFAULT_LIMIT_XML_BODY;

    return (apr_size_t)conf->limit_xml_body;
}

#if !defined (RLIMIT_CPU) || !(defined (RLIMIT_DATA) || defined (RLIMIT_VMEM) || defined(RLIMIT_AS)) || !defined (RLIMIT_NPROC)
static const char *no_set_limit(cmd_parms *cmd, void *conf_,
                                const char *arg, const char *arg2)
{
    ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, APLOGNO(00118)
                "%s not supported on this platform", cmd->cmd->name);

    return NULL;
}
#endif

#ifdef RLIMIT_CPU
static const char *set_limit_cpu(cmd_parms *cmd, void *conf_,
                                 const char *arg, const char *arg2)
{
    core_dir_config *conf = conf_;

    ap_unixd_set_rlimit(cmd, &conf->limit_cpu, arg, arg2, RLIMIT_CPU);
    return NULL;
}
#endif

#if defined (RLIMIT_DATA) || defined (RLIMIT_VMEM) || defined(RLIMIT_AS)
static const char *set_limit_mem(cmd_parms *cmd, void *conf_,
                                 const char *arg, const char * arg2)
{
    core_dir_config *conf = conf_;

#if defined(RLIMIT_AS)
    ap_unixd_set_rlimit(cmd, &conf->limit_mem, arg, arg2 ,RLIMIT_AS);
#elif defined(RLIMIT_DATA)
    ap_unixd_set_rlimit(cmd, &conf->limit_mem, arg, arg2, RLIMIT_DATA);
#elif defined(RLIMIT_VMEM)
    ap_unixd_set_rlimit(cmd, &conf->limit_mem, arg, arg2, RLIMIT_VMEM);
#endif

    return NULL;
}
#endif

#ifdef RLIMIT_NPROC
static const char *set_limit_nproc(cmd_parms *cmd, void *conf_,
                                   const char *arg, const char * arg2)
{
    core_dir_config *conf = conf_;

    ap_unixd_set_rlimit(cmd, &conf->limit_nproc, arg, arg2, RLIMIT_NPROC);
    return NULL;
}
#endif

static const char *set_recursion_limit(cmd_parms *cmd, void *dummy,
                                       const char *arg1, const char *arg2)
{
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);
    int limit = atoi(arg1);

    if (limit <= 0) {
        return "The recursion limit must be greater than zero.";
    }
    if (limit < 4) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00119)
                     "Limiting internal redirects to very low numbers may "
                     "cause normal requests to fail.");
    }

    conf->redirect_limit = limit;

    if (arg2) {
        limit = atoi(arg2);

        if (limit <= 0) {
            return "The recursion limit must be greater than zero.";
        }
        if (limit < 4) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00120)
                         "Limiting the subrequest depth to a very low level may"
                         " cause normal requests to fail.");
        }
    }

    conf->subreq_limit = limit;

    return NULL;
}

static void log_backtrace(const request_rec *r)
{
    const request_rec *top = r;

    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00121)
                  "r->uri = %s", r->uri ? r->uri : "(unexpectedly NULL)");

    while (top && (top->prev || top->main)) {
        if (top->prev) {
            top = top->prev;
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00122)
                          "redirected from r->uri = %s",
                          top->uri ? top->uri : "(unexpectedly NULL)");
        }

        if (!top->prev && top->main) {
            top = top->main;
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00123)
                          "subrequested from r->uri = %s",
                          top->uri ? top->uri : "(unexpectedly NULL)");
        }
    }
}

/*
 * check whether redirect limit is reached
 */
AP_DECLARE(int) ap_is_recursion_limit_exceeded(const request_rec *r)
{
    core_server_config *conf =
        ap_get_core_module_config(r->server->module_config);
    const request_rec *top = r;
    int redirects = 0, subreqs = 0;
    int rlimit = conf->redirect_limit
                 ? conf->redirect_limit
                 : AP_DEFAULT_MAX_INTERNAL_REDIRECTS;
    int slimit = conf->subreq_limit
                 ? conf->subreq_limit
                 : AP_DEFAULT_MAX_SUBREQ_DEPTH;


    while (top->prev || top->main) {
        if (top->prev) {
            if (++redirects >= rlimit) {
                /* uuh, too much. */
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00124)
                              "Request exceeded the limit of %d internal "
                              "redirects due to probable configuration error. "
                              "Use 'LimitInternalRecursion' to increase the "
                              "limit if necessary. Use 'LogLevel debug' to get "
                              "a backtrace.", rlimit);

                /* post backtrace */
                log_backtrace(r);

                /* return failure */
                return 1;
            }

            top = top->prev;
        }

        if (!top->prev && top->main) {
            if (++subreqs >= slimit) {
                /* uuh, too much. */
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00125)
                              "Request exceeded the limit of %d subrequest "
                              "nesting levels due to probable configuration "
                              "error. Use 'LimitInternalRecursion' to increase "
                              "the limit if necessary. Use 'LogLevel debug' to "
                              "get a backtrace.", slimit);

                /* post backtrace */
                log_backtrace(r);

                /* return failure */
                return 1;
            }

            top = top->main;
        }
    }

    /* recursion state: ok */
    return 0;
}

static const char *set_trace_enable(cmd_parms *cmd, void *dummy,
                                    const char *arg1)
{
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);

    if (ap_cstr_casecmp(arg1, "on") == 0) {
        conf->trace_enable = AP_TRACE_ENABLE;
    }
    else if (ap_cstr_casecmp(arg1, "off") == 0) {
        conf->trace_enable = AP_TRACE_DISABLE;
    }
    else if (ap_cstr_casecmp(arg1, "extended") == 0) {
        conf->trace_enable = AP_TRACE_EXTENDED;
    }
    else {
        return "TraceEnable must be one of 'on', 'off', or 'extended'";
    }

    return NULL;
}

static const char *set_protocols(cmd_parms *cmd, void *dummy,
                                 const char *arg)
{
    core_server_config *conf =
    ap_get_core_module_config(cmd->server->module_config);
    const char **np;
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);

    if (err) {
        return err;
    }
    
    np = (const char **)apr_array_push(conf->protocols);
    *np = arg;

    return NULL;
}

static const char *set_protocols_honor_order(cmd_parms *cmd, void *dummy,
                                             const char *arg)
{
    core_server_config *conf =
    ap_get_core_module_config(cmd->server->module_config);
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
    
    if (err) {
        return err;
    }
    
    if (ap_cstr_casecmp(arg, "on") == 0) {
        conf->protocols_honor_order = 1;
    }
    else if (ap_cstr_casecmp(arg, "off") == 0) {
        conf->protocols_honor_order = 0;
    }
    else {
        return "ProtocolsHonorOrder must be 'on' or 'off'";
    }
    
    return NULL;
}

static const char *set_http_protocol(cmd_parms *cmd, void *dummy,
                                     const char *arg)
{
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);

    if (strncmp(arg, "min=", 4) == 0) {
        arg += 4;
        if (strcmp(arg, "0.9") == 0)
            conf->http09_enable = AP_HTTP09_ENABLE;
        else if (strcmp(arg, "1.0") == 0)
            conf->http09_enable = AP_HTTP09_DISABLE;
        else
            return "HttpProtocol 'min' must be one of '0.9' and '1.0'";
        return NULL;
    }

    if (strcmp(arg, "strict") == 0)
        conf->http_conformance = AP_HTTP_CONFORMANCE_STRICT;
    else if (strcmp(arg, "strict,log-only") == 0)
        conf->http_conformance = AP_HTTP_CONFORMANCE_STRICT|
                                 AP_HTTP_CONFORMANCE_LOGONLY;
    else if (strcmp(arg, "liberal") == 0)
        conf->http_conformance = AP_HTTP_CONFORMANCE_LIBERAL;
    else
        return "HttpProtocol accepts 'min=0.9', 'min=1.0', 'liberal', "
               "'strict', 'strict,log-only'";

    if ((conf->http_conformance & AP_HTTP_CONFORMANCE_STRICT) &&
        (conf->http_conformance & AP_HTTP_CONFORMANCE_LIBERAL)) {
        return "HttpProtocol 'strict' and 'liberal' are mutually exclusive";
    }

    return NULL;
}

static const char *set_async_filter(cmd_parms *cmd, void *dummy,
                                             const char *arg)
{
    core_server_config *conf =
    ap_get_core_module_config(cmd->server->module_config);
    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);

    if (err) {
        return err;
    }

    if (ap_cstr_casecmp(arg, "network") == 0) {
        conf->async_filter = AP_FTYPE_NETWORK;
    }
    else if (ap_cstr_casecmp(arg, "connection") == 0) {
        conf->async_filter = AP_FTYPE_CONNECTION;
    }
    else if (ap_cstr_casecmp(arg, "request") == 0) {
        conf->async_filter = 0;
    }
    else {
        return "AsyncFilter must be 'network', 'connection' or 'request'";
    }
    conf->async_filter_set = 1;

    return NULL;
}

static const char *set_http_method(cmd_parms *cmd, void *conf, const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL)
        return err;
    ap_method_register(cmd->pool, arg);
    return NULL;
}

static const char *set_cl_head_zero(cmd_parms *cmd, void *dummy, int arg)
{
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);

    if (arg) {
        conf->http_cl_head_zero = AP_HTTP_CL_HEAD_ZERO_ENABLE;
    } else {
        conf->http_cl_head_zero = AP_HTTP_CL_HEAD_ZERO_DISABLE;
    }
    return NULL;
}

static const char *set_expect_strict(cmd_parms *cmd, void *dummy, int arg)
{
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);

    if (arg) {
        conf->http_expect_strict = AP_HTTP_EXPECT_STRICT_ENABLE;
    } else {
        conf->http_expect_strict = AP_HTTP_EXPECT_STRICT_DISABLE;
    }
    return NULL;
}

static apr_hash_t *errorlog_hash;

static int log_constant_item(const ap_errorlog_info *info, const char *arg,
                             char *buf, int buflen)
{
    char *end = apr_cpystrn(buf, arg, buflen);
    return end - buf;
}

static char *parse_errorlog_misc_string(apr_pool_t *p,
                                        ap_errorlog_format_item *it,
                                        const char **sa)
{
    const char *s;
    char scratch[MAX_STRING_LEN];
    char *d = scratch;
    /*
     * non-leading white space terminates this string to allow the next field
     * separator to be inserted
     */
    int at_start = 1;

    it->func = log_constant_item;
    s = *sa;

    while (*s && *s != '%' && (*s != ' ' || at_start) && d < scratch + MAX_STRING_LEN) {
        if (*s != '\\') {
            if (*s != ' ') {
                at_start = 0;
            }
            *d++ = *s++;
        }
        else {
            s++;
            switch (*s) {
            case 'r':
                *d++ = '\r';
                s++;
                break;
            case 'n':
                *d++ = '\n';
                s++;
                break;
            case 't':
                *d++ = '\t';
                s++;
                break;
            case '\0':
                /* handle end of string */
                *d++ = '\\';
                break;
            default:
                /* copy next char verbatim */
                *d++ = *s++;
                break;
            }
        }
    }
    *d = '\0';
    it->arg = apr_pstrdup(p, scratch);

    *sa = s;
    return NULL;
}

static char *parse_errorlog_item(apr_pool_t *p, ap_errorlog_format_item *it,
                                 const char **sa)
{
    const char *s = *sa;
    ap_errorlog_handler *handler;
    int i;

    if (*s != '%') {
        if (*s == ' ') {
            it->flags |= AP_ERRORLOG_FLAG_FIELD_SEP;
        }
        return parse_errorlog_misc_string(p, it, sa);
    }

    ++s;

    if (*s == ' ') {
        /* percent-space (% ) is a field separator */
        it->flags |= AP_ERRORLOG_FLAG_FIELD_SEP;
        *sa = ++s;
        /* recurse */
        return parse_errorlog_item(p, it, sa);
    }
    else if (*s == '%') {
        it->arg = "%";
        it->func = log_constant_item;
        *sa = ++s;
        return NULL;
    }

    while (*s) {
        switch (*s) {
        case '{':
            ++s;
            it->arg = ap_getword(p, &s, '}');
            break;
        case '+':
            ++s;
            it->flags |= AP_ERRORLOG_FLAG_REQUIRED;
            break;
        case '-':
            ++s;
            it->flags |= AP_ERRORLOG_FLAG_NULL_AS_HYPHEN;
            break;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            i = *s - '0';
            while (apr_isdigit(*++s))
                i = i * 10 + (*s) - '0';
            it->min_loglevel = i;
            break;
        case 'M':
            it->func = NULL;
            it->flags |= AP_ERRORLOG_FLAG_MESSAGE;
            *sa = ++s;
            return NULL;
        default:
            handler = (ap_errorlog_handler *)apr_hash_get(errorlog_hash, s, 1);
            if (!handler) {
                char dummy[2];

                dummy[0] = *s;
                dummy[1] = '\0';
                return apr_pstrcat(p, "Unrecognized error log format directive %",
                               dummy, NULL);
            }
            it->func = handler->func;
            *sa = ++s;
            return NULL;
        }
    }

    return "Ran off end of error log format parsing args to some directive";
}

static apr_array_header_t *parse_errorlog_string(apr_pool_t *p,
                                                 const char *s,
                                                 const char **err,
                                                 int is_main_fmt)
{
    apr_array_header_t *a = apr_array_make(p, 30,
                                           sizeof(ap_errorlog_format_item));
    char *res;
    int seen_msg_fmt = 0;

    while (s && *s) {
        ap_errorlog_format_item *item =
            (ap_errorlog_format_item *)apr_array_push(a);
        memset(item, 0, sizeof(*item));
        res = parse_errorlog_item(p, item, &s);
        if (res) {
            *err = res;
            return NULL;
        }
        if (item->flags & AP_ERRORLOG_FLAG_MESSAGE) {
            if (!is_main_fmt) {
                *err = "%M cannot be used in once-per-request or "
                       "once-per-connection formats";
                return NULL;
            }
            seen_msg_fmt = 1;
        }
        if (is_main_fmt && item->flags & AP_ERRORLOG_FLAG_REQUIRED) {
            *err = "The '+' flag cannot be used in the main error log format";
            return NULL;
        }
        if (!is_main_fmt && item->min_loglevel) {
            *err = "The loglevel cannot be used as a condition in "
                   "once-per-request or once-per-connection formats";
            return NULL;
        }
        if (item->min_loglevel > APLOG_TRACE8) {
            *err = "The specified loglevel modifier is out of range";
            return NULL;
        }
    }

    if (is_main_fmt && !seen_msg_fmt) {
        *err = "main ErrorLogFormat must contain message format string '%M'";
        return NULL;
    }

    return a;
}

static const char *set_errorlog(cmd_parms *cmd, void *dummy, const char *arg1,
                                const char *arg2)
{
    ap_errorlog_provider *provider;
    const char *err;
    cmd->server->errorlog_provider = NULL;

    if (!arg2) {
        /* Stay backward compatible and check for "syslog" */
        if (strncmp("syslog", arg1, 6) == 0) {
            arg2 = arg1 + 7; /* skip the ':' if any */
            arg1 = "syslog";
        }
        else {
            /* Admin can define only "ErrorLog provider" and we should 
             * still handle that using the defined provider, but with empty
             * error_fname. */
            provider = ap_lookup_provider(AP_ERRORLOG_PROVIDER_GROUP, arg1,
                                          AP_ERRORLOG_PROVIDER_VERSION);
            if (provider) {
                arg2 = "";
            }
            else {
                return set_server_string_slot(cmd, dummy, arg1);
            }
        }
    }

    if (strcmp("file", arg1) == 0) {
        return set_server_string_slot(cmd, dummy, arg2);
    }

    provider = ap_lookup_provider(AP_ERRORLOG_PROVIDER_GROUP, arg1,
                                    AP_ERRORLOG_PROVIDER_VERSION);
    if (!provider) {
        return apr_psprintf(cmd->pool,
                            "Unknown ErrorLog provider: %s",
                            arg1);
    }

    err = provider->parse_errorlog_arg(cmd, arg2);
    if (err) {
        return err;
    }

    cmd->server->errorlog_provider = provider;
    return set_server_string_slot(cmd, dummy, arg2);
}

static const char *set_errorlog_format(cmd_parms *cmd, void *dummy,
                                       const char *arg1, const char *arg2)
{
    const char *err_string = NULL;
    core_server_config *conf =
        ap_get_core_module_config(cmd->server->module_config);

    if (!arg2) {
        conf->error_log_format = parse_errorlog_string(cmd->pool, arg1,
                                                       &err_string, 1);
    }
    else if (!ap_cstr_casecmp(arg1, "connection")) {
        if (!conf->error_log_conn) {
            conf->error_log_conn = apr_array_make(cmd->pool, 5,
                                                  sizeof(apr_array_header_t *));
        }

        if (*arg2) {
            apr_array_header_t **e;
            e = (apr_array_header_t **) apr_array_push(conf->error_log_conn);
            *e = parse_errorlog_string(cmd->pool, arg2, &err_string, 0);
        }
    }
    else if (!ap_cstr_casecmp(arg1, "request")) {
        if (!conf->error_log_req) {
            conf->error_log_req = apr_array_make(cmd->pool, 5,
                                                 sizeof(apr_array_header_t *));
        }

        if (*arg2) {
            apr_array_header_t **e;
            e = (apr_array_header_t **) apr_array_push(conf->error_log_req);
            *e = parse_errorlog_string(cmd->pool, arg2, &err_string, 0);
        }
    }
    else {
        err_string = "ErrorLogFormat type must be one of request, connection";
    }

    return err_string;
}

AP_DECLARE(void) ap_register_errorlog_handler(apr_pool_t *p, char *tag,
                                              ap_errorlog_handler_fn_t *handler,
                                              int flags)
{
    ap_errorlog_handler *log_struct = apr_palloc(p, sizeof(*log_struct));
    log_struct->func = handler;
    log_struct->flags = flags;

    apr_hash_set(errorlog_hash, tag, 1, (const void *)log_struct);
}


static const char *set_merge_trailers(cmd_parms *cmd, void *dummy, int arg)
{
    core_server_config *conf = ap_get_module_config(cmd->server->module_config,
                                                    &core_module);
    conf->merge_trailers = (arg ? AP_MERGE_TRAILERS_ENABLE :
            AP_MERGE_TRAILERS_DISABLE);

    return NULL;
}

/* Note --- ErrorDocument will now work from .htaccess files.
 * The AllowOverride of Fileinfo allows webmasters to turn it off
 */

static const command_rec core_cmds[] = {

/* Old access config file commands */

AP_INIT_RAW_ARGS("<Directory", dirsection, NULL, RSRC_CONF,
  "Container for directives affecting resources located in the specified "
  "directories"),
AP_INIT_RAW_ARGS("<Location", urlsection, NULL, RSRC_CONF,
  "Container for directives affecting resources accessed through the "
  "specified URL paths"),
AP_INIT_RAW_ARGS("<VirtualHost", virtualhost_section, NULL, RSRC_CONF,
  "Container to map directives to a particular virtual host, takes one or "
  "more host addresses"),
AP_INIT_RAW_ARGS("<Files", filesection, NULL, OR_ALL,
  "Container for directives affecting files matching specified patterns"),
AP_INIT_RAW_ARGS("<Limit", ap_limit_section, NULL, OR_LIMIT | OR_AUTHCFG,
  "Container for authentication directives when accessed using specified HTTP "
  "methods"),
AP_INIT_RAW_ARGS("<LimitExcept", ap_limit_section, (void*)1,
                 OR_LIMIT | OR_AUTHCFG,
  "Container for authentication directives to be applied when any HTTP "
  "method other than those specified is used to access the resource"),
AP_INIT_TAKE1("<IfModule", start_ifmod, NULL, EXEC_ON_READ | OR_ALL,
  "Container for directives based on existence of specified modules"),
AP_INIT_TAKE1("<IfDefine", start_ifdefine, NULL, EXEC_ON_READ | OR_ALL,
  "Container for directives based on existence of command line defines"),
AP_INIT_RAW_ARGS("<DirectoryMatch", dirsection, (void*)1, RSRC_CONF,
  "Container for directives affecting resources located in the "
  "specified directories"),
AP_INIT_RAW_ARGS("<LocationMatch", urlsection, (void*)1, RSRC_CONF,
  "Container for directives affecting resources accessed through the "
  "specified URL paths"),
AP_INIT_RAW_ARGS("<FilesMatch", filesection, (void*)1, OR_ALL,
  "Container for directives affecting files matching specified patterns"),
#ifdef GPROF
AP_INIT_TAKE1("GprofDir", set_gprof_dir, NULL, RSRC_CONF,
  "Directory to plop gmon.out files"),
#endif
AP_INIT_TAKE1("AddDefaultCharset", set_add_default_charset, NULL, OR_FILEINFO,
  "The name of the default charset to add to any Content-Type without one or 'Off' to disable"),
AP_INIT_TAKE1("AcceptPathInfo", set_accept_path_info, NULL, OR_FILEINFO,
  "Set to on or off for PATH_INFO to be accepted by handlers, or default for the per-handler preference"),
AP_INIT_TAKE12("Define", set_define, NULL, EXEC_ON_READ|RSRC_CONF,
              "Define a variable, optionally to a value.  Same as passing -D to the command line."),
AP_INIT_TAKE1("UnDefine", unset_define, NULL, EXEC_ON_READ|RSRC_CONF,
              "Undefine the existence of a variable. Undo a Define."),
AP_INIT_RAW_ARGS("Error", generate_message, (void*) APLOG_ERR, OR_ALL,
                 "Generate error message from within configuration."),
AP_INIT_RAW_ARGS("Warning", generate_message, (void*) APLOG_WARNING, OR_ALL,
                 "Generate warning message from within configuration."),
AP_INIT_RAW_ARGS("<If", ifsection, COND_IF, OR_ALL,
  "Container for directives to be conditionally applied"),
AP_INIT_RAW_ARGS("<ElseIf", ifsection, COND_ELSEIF, OR_ALL,
  "Container for directives to be conditionally applied"),
AP_INIT_RAW_ARGS("<Else", ifsection, COND_ELSE, OR_ALL,
  "Container for directives to be conditionally applied"),

/* Old resource config file commands */

AP_INIT_RAW_ARGS("AccessFileName", set_access_name, NULL, RSRC_CONF,
  "Name(s) of per-directory config files (default: .htaccess)"),
AP_INIT_TAKE1("DocumentRoot", set_document_root, NULL, RSRC_CONF,
  "Root directory of the document tree"),
AP_INIT_TAKE2("ErrorDocument", set_error_document, NULL, OR_FILEINFO,
  "Change responses for HTTP errors"),
AP_INIT_RAW_ARGS("AllowOverride", set_override, NULL, ACCESS_CONF,
  "Controls what groups of directives can be configured by per-directory "
  "config files"),
AP_INIT_TAKE_ARGV("AllowOverrideList", set_override_list, NULL, ACCESS_CONF,
  "Controls what individual directives can be configured by per-directory "
  "config files"),
AP_INIT_RAW_ARGS("Options", set_options, NULL, OR_OPTIONS,
  "Set a number of attributes for a given directory"),
AP_INIT_TAKE1("DefaultType", set_default_type, NULL, OR_FILEINFO,
  "the default media type for otherwise untyped files (DEPRECATED)"),
AP_INIT_RAW_ARGS("FileETag", set_etag_bits, NULL, OR_FILEINFO,
  "Specify components used to construct a file's ETag"),
AP_INIT_TAKE1("EnableMMAP", set_enable_mmap, NULL, OR_FILEINFO,
  "Controls whether memory-mapping may be used to read files"),
AP_INIT_TAKE1("EnableSendfile", set_enable_sendfile, NULL, OR_FILEINFO,
  "Controls whether sendfile may be used to transmit files"),

/* Old server config file commands */

AP_INIT_TAKE1("Protocol", set_protocol, NULL, RSRC_CONF,
  "Set the Protocol for httpd to use."),
AP_INIT_TAKE2("AcceptFilter", set_accf_map, NULL, RSRC_CONF,
  "Set the Accept Filter to use for a protocol"),
AP_INIT_TAKE1("Port", ap_set_deprecated, NULL, RSRC_CONF,
  "Port was replaced with Listen in Apache 2.0"),
AP_INIT_TAKE1("HostnameLookups", set_hostname_lookups, NULL,
  ACCESS_CONF|RSRC_CONF,
  "\"on\" to enable, \"off\" to disable reverse DNS lookups, or \"double\" to "
  "enable double-reverse DNS lookups"),
AP_INIT_TAKE1("ServerAdmin", set_server_string_slot,
  (void *)APR_OFFSETOF(server_rec, server_admin), RSRC_CONF,
  "The email address of the server administrator"),
AP_INIT_TAKE1("ServerName", server_hostname_port, NULL, RSRC_CONF,
  "The hostname and port of the server"),
AP_INIT_TAKE1("ServerSignature", set_signature_flag, NULL, OR_ALL,
  "En-/disable server signature (on|off|email)"),
AP_INIT_TAKE1("ServerRoot", set_server_root, NULL, RSRC_CONF | EXEC_ON_READ,
  "Common directory of server-related files (logs, confs, etc.)"),
AP_INIT_TAKE1("DefaultRuntimeDir", set_runtime_dir, NULL, RSRC_CONF | EXEC_ON_READ,
  "Common directory for run-time files (shared memory, locks, etc.)"),
AP_INIT_TAKE12("ErrorLog", set_errorlog,
  (void *)APR_OFFSETOF(server_rec, error_fname), RSRC_CONF,
  "The filename of the error log"),
AP_INIT_TAKE12("ErrorLogFormat", set_errorlog_format, NULL, RSRC_CONF,
  "Format string for the ErrorLog"),
AP_INIT_RAW_ARGS("ServerAlias", set_server_alias, NULL, RSRC_CONF,
  "A name or names alternately used to access the server"),
AP_INIT_TAKE1("ServerPath", set_serverpath, NULL, RSRC_CONF,
  "The pathname the server can be reached at"),
AP_INIT_TAKE1("Timeout", set_timeout, NULL, RSRC_CONF,
  "Timeout duration (sec)"),
AP_INIT_FLAG("ContentDigest", set_content_md5, NULL, OR_OPTIONS,
  "whether or not to send a Content-MD5 header with each request"),
AP_INIT_TAKE1("UseCanonicalName", set_use_canonical_name, NULL,
  RSRC_CONF|ACCESS_CONF,
  "How to work out the ServerName : Port when constructing URLs"),
AP_INIT_TAKE1("UseCanonicalPhysicalPort", set_use_canonical_phys_port, NULL,
  RSRC_CONF|ACCESS_CONF,
  "Whether to use the physical Port when constructing URLs"),
/* TODO: RlimitFoo should all be part of mod_cgi, not in the core */
/* TODO: ListenBacklog in MPM */
AP_INIT_TAKE1("Include", include_config, NULL,
  (RSRC_CONF | ACCESS_CONF | EXEC_ON_READ),
  "Name(s) of the config file(s) to be included; fails if the wildcard does "
  "not match at least one file"),
AP_INIT_TAKE1("IncludeOptional", include_config, (void*)1,
  (RSRC_CONF | ACCESS_CONF | EXEC_ON_READ),
  "Name or pattern of the config file(s) to be included; ignored if the file "
  "does not exist or the pattern does not match any files"),
AP_INIT_ITERATE("LogLevel", set_loglevel, NULL, RSRC_CONF|ACCESS_CONF,
  "Level of verbosity in error logging"),
AP_INIT_TAKE_ARGV("LogLevelOverride", set_loglevel_override, NULL, RSRC_CONF,
  "Override LogLevel for clients with certain IPs"),
AP_INIT_TAKE1("NameVirtualHost", ap_set_name_virtual_host, NULL, RSRC_CONF,
  "A numeric IP address:port, or the name of a host"),
AP_INIT_TAKE1("ServerTokens", set_serv_tokens, NULL, RSRC_CONF,
  "Determine tokens displayed in the Server: header - Min(imal), "
  "Major, Minor, Prod(uctOnly), OS, or Full"),
AP_INIT_TAKE1("LimitRequestLine", set_limit_req_line, NULL, RSRC_CONF,
  "Limit on maximum size of an HTTP request line"),
AP_INIT_TAKE1("LimitRequestFieldsize", set_limit_req_fieldsize, NULL,
  RSRC_CONF,
  "Limit on maximum size of an HTTP request header field"),
AP_INIT_TAKE1("LimitRequestFields", set_limit_req_fields, NULL, RSRC_CONF,
  "Limit (0 = unlimited) on max number of header fields in a request message"),
AP_INIT_TAKE1("LimitRequestBody", set_limit_req_body,
  (void*)APR_OFFSETOF(core_dir_config, limit_req_body), OR_ALL,
  "Limit (in bytes) on maximum size of request message body"),
AP_INIT_TAKE1("LimitXMLRequestBody", set_limit_xml_req_body, NULL, OR_ALL,
              "Limit (in bytes) on maximum size of an XML-based request "
              "body"),
AP_INIT_RAW_ARGS("Mutex", ap_set_mutex, NULL, RSRC_CONF,
                 "mutex (or \"default\") and mechanism"),

AP_INIT_TAKE1("MaxRanges", set_max_ranges, NULL, RSRC_CONF|ACCESS_CONF,
              "Maximum number of Ranges in a request before returning the entire "
              "resource, or 0 for unlimited"),
AP_INIT_TAKE1("MaxRangeOverlaps", set_max_overlaps, NULL, RSRC_CONF|ACCESS_CONF,
              "Maximum number of overlaps in Ranges in a request before returning the entire "
              "resource, or 0 for unlimited"),
AP_INIT_TAKE1("MaxRangeReversals", set_max_reversals, NULL, RSRC_CONF|ACCESS_CONF,
              "Maximum number of reversals in Ranges in a request before returning the entire "
              "resource, or 0 for unlimited"),
/* System Resource Controls */
#ifdef RLIMIT_CPU
AP_INIT_TAKE12("RLimitCPU", set_limit_cpu,
  (void*)APR_OFFSETOF(core_dir_config, limit_cpu),
  OR_ALL, "Soft/hard limits for max CPU usage in seconds"),
#else
AP_INIT_TAKE12("RLimitCPU", no_set_limit, NULL,
  OR_ALL, "Soft/hard limits for max CPU usage in seconds"),
#endif
#if defined (RLIMIT_DATA) || defined (RLIMIT_VMEM) || defined (RLIMIT_AS)
AP_INIT_TAKE12("RLimitMEM", set_limit_mem,
  (void*)APR_OFFSETOF(core_dir_config, limit_mem),
  OR_ALL, "Soft/hard limits for max memory usage per process"),
#else
AP_INIT_TAKE12("RLimitMEM", no_set_limit, NULL,
  OR_ALL, "Soft/hard limits for max memory usage per process"),
#endif
#ifdef RLIMIT_NPROC
AP_INIT_TAKE12("RLimitNPROC", set_limit_nproc,
  (void*)APR_OFFSETOF(core_dir_config, limit_nproc),
  OR_ALL, "soft/hard limits for max number of processes per uid"),
#else
AP_INIT_TAKE12("RLimitNPROC", no_set_limit, NULL,
   OR_ALL, "soft/hard limits for max number of processes per uid"),
#endif

/* internal recursion stopper */
AP_INIT_TAKE12("LimitInternalRecursion", set_recursion_limit, NULL, RSRC_CONF,
              "maximum recursion depth of internal redirects and subrequests"),

AP_INIT_FLAG("CGIPassAuth", set_cgi_pass_auth, NULL, OR_AUTHCFG,
             "Controls whether HTTP authorization headers, normally hidden, will "
             "be passed to scripts"),
AP_INIT_TAKE2("CGIVar", set_cgi_var, NULL, OR_FILEINFO,
              "Controls how some CGI variables are set"),
AP_INIT_FLAG("QualifyRedirectURL", set_qualify_redirect_url, NULL, OR_FILEINFO,
             "Controls whether the REDIRECT_URL environment variable is fully "
             "qualified"),

AP_INIT_TAKE1("ForceType", ap_set_string_slot_lower,
       (void *)APR_OFFSETOF(core_dir_config, mime_type), OR_FILEINFO,
     "a mime type that overrides other configured type"),
AP_INIT_TAKE1("SetHandler", set_sethandler, NULL, OR_FILEINFO,
   "a handler name that overrides any other configured handler"),
AP_INIT_TAKE1("SetOutputFilter", ap_set_string_slot,
       (void *)APR_OFFSETOF(core_dir_config, output_filters), OR_FILEINFO,
   "filter (or ; delimited list of filters) to be run on the request content"),
AP_INIT_TAKE1("SetInputFilter", ap_set_string_slot,
       (void *)APR_OFFSETOF(core_dir_config, input_filters), OR_FILEINFO,
   "filter (or ; delimited list of filters) to be run on the request body"),
AP_INIT_TAKE1("AllowEncodedSlashes", set_allow2f, NULL, RSRC_CONF,
             "Allow URLs containing '/' encoded as '%2F'"),

/* scoreboard.c directives */
AP_INIT_TAKE1("ScoreBoardFile", ap_set_scoreboard, NULL, RSRC_CONF,
              "A file for Apache to maintain runtime process management information"),
AP_INIT_FLAG("ExtendedStatus", ap_set_extended_status, NULL, RSRC_CONF,
             "\"On\" to track extended status information, \"Off\" to disable"),
AP_INIT_FLAG("SeeRequestTail", ap_set_reqtail, NULL, RSRC_CONF,
             "For extended status, \"On\" to see the last 63 chars of "
             "the request line, \"Off\" (default) to see the first 63"),

/*
 * These are default configuration directives that mpms can/should
 * pay attention to.
 * XXX These are not for all platforms, and even some Unix MPMs might not want
 * some directives.
 */
AP_INIT_TAKE1("PidFile",  ap_mpm_set_pidfile, NULL, RSRC_CONF,
              "A file for logging the server process ID"),
AP_INIT_TAKE1("MaxRequestsPerChild", ap_mpm_set_max_requests, NULL, RSRC_CONF,
              "Maximum number of connections a particular child serves before "
              "dying. (DEPRECATED, use MaxConnectionsPerChild)"),
AP_INIT_TAKE1("MaxConnectionsPerChild", ap_mpm_set_max_requests, NULL, RSRC_CONF,
              "Maximum number of connections a particular child serves before dying."),
AP_INIT_TAKE1("CoreDumpDirectory", ap_mpm_set_coredumpdir, NULL, RSRC_CONF,
              "The location of the directory Apache changes to before dumping core"),
AP_INIT_TAKE1("MaxMemFree", ap_mpm_set_max_mem_free, NULL, RSRC_CONF,
              "Maximum number of 1k blocks a particular child's allocator may hold."),
AP_INIT_TAKE1("ThreadStackSize", ap_mpm_set_thread_stacksize, NULL, RSRC_CONF,
              "Size in bytes of stack used by threads handling client connections"),
#if AP_ENABLE_EXCEPTION_HOOK
AP_INIT_TAKE1("EnableExceptionHook", ap_mpm_set_exception_hook, NULL, RSRC_CONF,
              "Controls whether exception hook may be called after a crash"),
#endif
AP_INIT_TAKE1("TraceEnable", set_trace_enable, NULL, RSRC_CONF,
              "'on' (default), 'off' or 'extended' to trace request body content"),
AP_INIT_FLAG("MergeTrailers", set_merge_trailers, NULL, RSRC_CONF,
              "merge request trailers into request headers or not"),
AP_INIT_ITERATE("HttpProtocol", set_http_protocol, NULL, RSRC_CONF,
              "'min=0.9' (default) or 'min=1.0' to allow/deny HTTP/0.9; "
              "'liberal', 'strict', 'strict,log-only'"),
AP_INIT_ITERATE("RegisterHttpMethod", set_http_method, NULL, RSRC_CONF,
                "Registers non-standard HTTP methods"),
AP_INIT_FLAG("HttpContentLengthHeadZero", set_cl_head_zero, NULL, OR_OPTIONS,
  "whether to permit Content-Length of 0 responses to HEAD requests"),
AP_INIT_FLAG("HttpExpectStrict", set_expect_strict, NULL, OR_OPTIONS,
  "whether to return a 417 if a client doesn't send 100-Continue"),
AP_INIT_ITERATE("Protocols", set_protocols, NULL, RSRC_CONF,
                "Controls which protocols are allowed"),
AP_INIT_TAKE1("ProtocolsHonorOrder", set_protocols_honor_order, NULL, RSRC_CONF,
              "'off' (default) or 'on' to respect given order of protocols, "
              "by default the client specified order determines selection"),
AP_INIT_TAKE1("AsyncFilter", set_async_filter, NULL, RSRC_CONF,
              "'network', 'connection' (default) or 'request' to limit the "
              "types of filters that support asynchronous handling"),
{ NULL }
};

/*****************************************************************
 *
 * Core handlers for various phases of server operation...
 */

AP_DECLARE_NONSTD(int) ap_core_translate(request_rec *r)
{
    apr_status_t rv;
    char *path;

    /* XXX this seems too specific, this should probably become
     * some general-case test
     */
    if (r->proxyreq) {
        return HTTP_FORBIDDEN;
    }
    if (!r->uri || ((r->uri[0] != '/') && strcmp(r->uri, "*"))) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00126)
                     "Invalid URI in request %s", r->the_request);
        return HTTP_BAD_REQUEST;
    }

    if (r->server->path
        && !strncmp(r->uri, r->server->path, r->server->pathlen)
        && (r->server->path[r->server->pathlen - 1] == '/'
            || r->uri[r->server->pathlen] == '/'
            || r->uri[r->server->pathlen] == '\0'))
    {
        path = r->uri + r->server->pathlen;
    }
    else {
        path = r->uri;
    }
    /*
     * Make sure that we do not mess up the translation by adding two
     * /'s in a row.  This happens under windows when the document
     * root ends with a /
     */
    /* skip all leading /'s (e.g. http://localhost///foo)
     * so we are looking at only the relative path.
     */
    while (*path == '/') {
        ++path;
    }
    if ((rv = apr_filepath_merge(&r->filename, ap_document_root(r), path,
                                 APR_FILEPATH_TRUENAME
                               | APR_FILEPATH_SECUREROOT, r->pool))
                != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00127)
                     "Cannot map %s to file", r->the_request);
        return HTTP_FORBIDDEN;
    }
    r->canonical_filename = r->filename;

    return OK;
}

/*****************************************************************
 *
 * Test the filesystem name through directory_walk and file_walk
 */
static int core_map_to_storage(request_rec *r)
{
    int access_status;

    if ((access_status = ap_directory_walk(r))) {
        return access_status;
    }

    if ((access_status = ap_file_walk(r))) {
        return access_status;
    }

    return OK;
}


static int do_nothing(request_rec *r) { return OK; }

static int core_override_type(request_rec *r)
{
    core_dir_config *conf =
        (core_dir_config *)ap_get_core_module_config(r->per_dir_config);

    /* Check for overrides with ForceType / SetHandler
     */
    if (conf->mime_type && strcmp(conf->mime_type, "none"))
        ap_set_content_type(r, (char*) conf->mime_type);

    if (conf->expr_handler) { 
        const char *err;
        const char *val;
        val = ap_expr_str_exec(r, conf->expr_handler, &err);
        if (err) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(03154)
                          "Can't evaluate handler expression: %s", err);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        if (val != ap_strstr_c(val, "proxy:unix")) { 
            /* Retained for compatibility --  but not for UDS */
            char *tmp = apr_pstrdup(r->pool, val);
            ap_str_tolower(tmp);
            val = tmp;
        }

        if (strcmp(val, "none")) { 
            r->handler = val;
        }
    }
    else if (conf->handler && strcmp(conf->handler, "none")) { 
        r->handler = conf->handler;
    }

    /* Deal with the poor soul who is trying to force path_info to be
     * accepted within the core_handler, where they will let the subreq
     * address its contents.  This is toggled by the user in the very
     * beginning of the fixup phase (here!), so modules should override the user's
     * discretion in their own module fixup phase.  It is tristate, if
     * the user doesn't specify, the result is AP_REQ_DEFAULT_PATH_INFO.
     * (which the module may interpret to its own customary behavior.)
     * It won't be touched if the value is no longer AP_ACCEPT_PATHINFO_UNSET,
     * so any module changing the value prior to the fixup phase
     * OVERRIDES the user's choice.
     */
    if ((r->used_path_info == AP_REQ_DEFAULT_PATH_INFO)
        && (conf->accept_path_info != AP_ACCEPT_PATHINFO_UNSET)) {
        /* No module knew better, and the user coded AcceptPathInfo */
        r->used_path_info = conf->accept_path_info;
    }

    return OK;
}

static int default_handler(request_rec *r)
{
    conn_rec *c = r->connection;
    apr_bucket_brigade *bb;
    apr_bucket *e;
    core_dir_config *d;
    int errstatus;
    apr_file_t *fd = NULL;
    apr_status_t status;
    /* XXX if/when somebody writes a content-md5 filter we either need to
     *     remove this support or coordinate when to use the filter vs.
     *     when to use this code
     *     The current choice of when to compute the md5 here matches the 1.3
     *     support fairly closely (unlike 1.3, we don't handle computing md5
     *     when the charset is translated).
     */
    int bld_content_md5;

    d = (core_dir_config *)ap_get_core_module_config(r->per_dir_config);
    bld_content_md5 = (d->content_md5 == AP_CONTENT_MD5_ON)
                      && r->output_filters->frec->ftype != AP_FTYPE_RESOURCE;

    ap_allow_standard_methods(r, MERGE_ALLOW, M_GET, M_OPTIONS, M_POST, -1);

    /* If filters intend to consume the request body, they must
     * register an InputFilter to slurp the contents of the POST
     * data from the POST input stream.  It no longer exists when
     * the output filters are invoked by the default handler.
     */
    if ((errstatus = ap_discard_request_body(r)) != OK) {
        return errstatus;
    }

    if (r->method_number == M_GET || r->method_number == M_POST) {
        if (r->finfo.filetype == APR_NOFILE) {
            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00128)
                          "File does not exist: %s",
                          apr_pstrcat(r->pool, r->filename, r->path_info, NULL));
            return HTTP_NOT_FOUND;
        }

        /* Don't try to serve a dir.  Some OSs do weird things with
         * raw I/O on a dir.
         */
        if (r->finfo.filetype == APR_DIR) {
            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00129)
                          "Attempt to serve directory: %s", r->filename);
            return HTTP_NOT_FOUND;
        }

        if ((r->used_path_info != AP_REQ_ACCEPT_PATH_INFO) &&
            r->path_info && *r->path_info)
        {
            /* default to reject */
            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00130)
                          "File does not exist: %s",
                          apr_pstrcat(r->pool, r->filename, r->path_info, NULL));
            return HTTP_NOT_FOUND;
        }

        /* We understood the (non-GET) method, but it might not be legal for
           this particular resource. Check to see if the 'deliver_script'
           flag is set. If so, then we go ahead and deliver the file since
           it isn't really content (only GET normally returns content).

           Note: based on logic further above, the only possible non-GET
           method at this point is POST. In the future, we should enable
           script delivery for all methods.  */
        if (r->method_number != M_GET) {
            core_request_config *req_cfg;

            req_cfg = ap_get_core_module_config(r->request_config);
            if (!req_cfg->deliver_script) {
                /* The flag hasn't been set for this request. Punt. */
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00131)
                              "This resource does not accept the %s method.",
                              r->method);
                return HTTP_METHOD_NOT_ALLOWED;
            }
        }


        if ((status = apr_file_open(&fd, r->filename, APR_READ | APR_BINARY
#if APR_HAS_SENDFILE
                            | AP_SENDFILE_ENABLED(d->enable_sendfile)
#endif
                                    , 0, r->pool)) != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00132)
                          "file permissions deny server access: %s", r->filename);
            return HTTP_FORBIDDEN;
        }

        ap_update_mtime(r, r->finfo.mtime);
        ap_set_last_modified(r);
        ap_set_etag(r);
        ap_set_accept_ranges(r);
        ap_set_content_length(r, r->finfo.size);
        if (bld_content_md5) {
            apr_table_setn(r->headers_out, "Content-MD5",
                           ap_md5digest(r->pool, fd));
        }

        bb = apr_brigade_create(r->pool, c->bucket_alloc);

        if ((errstatus = ap_meets_conditions(r)) != OK) {
            apr_file_close(fd);
            r->status = errstatus;
        }
        else {
            e = apr_brigade_insert_file(bb, fd, 0, r->finfo.size, r->pool);

#if APR_HAS_MMAP
            if (d->enable_mmap == ENABLE_MMAP_OFF) {
                (void)apr_bucket_file_enable_mmap(e, 0);
            }
#endif
        }

        e = apr_bucket_eos_create(c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, e);

        status = ap_pass_brigade(r->output_filters, bb);
        if (status == APR_SUCCESS
            || r->status != HTTP_OK
            || c->aborted) {
            return OK;
        }
        else {
            /* no way to know what type of error occurred */
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00133)
                          "default_handler: ap_pass_brigade returned %i",
                          status);
            return AP_FILTER_ERROR;
        }
    }
    else {              /* unusual method (not GET or POST) */
        if (r->method_number == M_INVALID) {
            /* See if this looks like an undecrypted SSL handshake attempt.
             * It's safe to look a couple bytes into the_request if it exists, as it's
             * always allocated at least MIN_LINE_ALLOC (80) bytes.
             */
            if (r->the_request
                && r->the_request[0] == 0x16
                && (r->the_request[1] == 0x2 || r->the_request[1] == 0x3)) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00134)
                              "Invalid method in request %s - possible attempt to establish SSL connection on non-SSL port", r->the_request);
            } else {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00135)
                              "Invalid method in request %s", r->the_request);
            }
            return HTTP_NOT_IMPLEMENTED;
        }

        if (r->method_number == M_OPTIONS) {
            return ap_send_http_options(r);
        }
        return HTTP_METHOD_NOT_ALLOWED;
    }
}

/* Optional function coming from mod_logio, used for logging of output
 * traffic
 */
APR_OPTIONAL_FN_TYPE(ap_logio_add_bytes_out) *ap__logio_add_bytes_out;
APR_OPTIONAL_FN_TYPE(authz_some_auth_required) *ap__authz_ap_some_auth_required;

/* Insist that at least one module will undertake to provide system
 * security by dropping startup privileges.
 */
static int sys_privileges = 0;
AP_DECLARE(int) ap_sys_privileges_handlers(int inc)
{
    sys_privileges += inc;
    return sys_privileges;
}

static int check_errorlog_dir(apr_pool_t *p, server_rec *s)
{
    if (!s->error_fname || s->error_fname[0] == '|'
        || s->errorlog_provider != NULL) {
        return APR_SUCCESS;
    }
    else {
        char *abs = ap_server_root_relative(p, s->error_fname);
        char *dir = ap_make_dirstr_parent(p, abs);
        apr_finfo_t finfo;
        apr_status_t rv = apr_stat(&finfo, dir, APR_FINFO_TYPE, p);
        if (rv == APR_SUCCESS && finfo.filetype != APR_DIR)
            rv = APR_ENOTDIR;
        if (rv != APR_SUCCESS) {
            const char *desc = "main error log";
            if (s->defn_name)
                desc = apr_psprintf(p, "error log of vhost defined at %s:%d",
                                    s->defn_name, s->defn_line_number);
            ap_log_error(APLOG_MARK, APLOG_STARTUP|APLOG_EMERG, rv,
                          ap_server_conf, APLOGNO(02291)
                         "Cannot access directory '%s' for %s", dir, desc);
            return !OK;
        }
    }
    return OK;
}

static int core_check_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
    int rv = OK;
    while (s) {
        if (check_errorlog_dir(ptemp, s) != OK)
            rv = !OK;
        s = s->next;
    }
    return rv;
}


static int core_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp)
{
    ap_mutex_init(pconf);

    if (!saved_server_config_defines)
        init_config_defines(pconf);
    apr_pool_cleanup_register(pconf, NULL, reset_config_defines,
                              apr_pool_cleanup_null);

    mpm_common_pre_config(pconf);

    return OK;
}

static int core_post_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
    ap__logio_add_bytes_out = APR_RETRIEVE_OPTIONAL_FN(ap_logio_add_bytes_out);
    ident_lookup = APR_RETRIEVE_OPTIONAL_FN(ap_ident_lookup);
    ap__authz_ap_some_auth_required = APR_RETRIEVE_OPTIONAL_FN(authz_some_auth_required);
    authn_ap_auth_type = APR_RETRIEVE_OPTIONAL_FN(authn_ap_auth_type);
    authn_ap_auth_name = APR_RETRIEVE_OPTIONAL_FN(authn_ap_auth_name);
    access_compat_ap_satisfies = APR_RETRIEVE_OPTIONAL_FN(access_compat_ap_satisfies);

    set_banner(pconf);
    ap_setup_make_content_type(pconf);
    ap_setup_auth_internal(ptemp);
    if (!sys_privileges) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, 0, NULL, APLOGNO(00136)
                     "Server MUST relinquish startup privileges before "
                     "accepting connections.  Please ensure mod_unixd "
                     "or other system security module is loaded.");
        return !OK;
    }
    apr_pool_cleanup_register(pconf, NULL, ap_mpm_end_gen_helper,
                              apr_pool_cleanup_null);
    return OK;
}

static void core_insert_filter(request_rec *r)
{
    core_dir_config *conf = (core_dir_config *)
                            ap_get_core_module_config(r->per_dir_config);
    const char *filter, *filters = conf->output_filters;

    if (filters) {
        while (*filters && (filter = ap_getword(r->pool, &filters, ';'))) {
            ap_add_output_filter(filter, NULL, r, r->connection);
        }
    }

    filters = conf->input_filters;
    if (filters) {
        while (*filters && (filter = ap_getword(r->pool, &filters, ';'))) {
            ap_add_input_filter(filter, NULL, r, r->connection);
        }
    }
}

static apr_size_t num_request_notes = AP_NUM_STD_NOTES;

static apr_status_t reset_request_notes(void *dummy)
{
    num_request_notes = AP_NUM_STD_NOTES;
    return APR_SUCCESS;
}

AP_DECLARE(apr_size_t) ap_register_request_note(void)
{
    apr_pool_cleanup_register(apr_hook_global_pool, NULL, reset_request_notes,
                              apr_pool_cleanup_null);
    return num_request_notes++;
}

AP_DECLARE(void **) ap_get_request_note(request_rec *r, apr_size_t note_num)
{
    core_request_config *req_cfg;

    if (note_num >= num_request_notes) {
        return NULL;
    }

    req_cfg = (core_request_config *)
        ap_get_core_module_config(r->request_config);

    if (!req_cfg) {
        return NULL;
    }

    return &(req_cfg->notes[note_num]);
}

AP_DECLARE(apr_socket_t *) ap_get_conn_socket(conn_rec *c)
{
    return ap_get_core_module_config(c->conn_config);
}

static int core_create_req(request_rec *r)
{
    /* Alloc the config struct and the array of request notes in
     * a single block for efficiency
     */
    core_request_config *req_cfg;

    req_cfg = apr_pcalloc(r->pool, sizeof(core_request_config) +
                          sizeof(void *) * num_request_notes);
    req_cfg->notes = (void **)((char *)req_cfg + sizeof(core_request_config));

    /* ### temporarily enable script delivery as the default */
    req_cfg->deliver_script = 1;

    if (r->main) {
        core_request_config *main_req_cfg = (core_request_config *)
            ap_get_core_module_config(r->main->request_config);
        req_cfg->bb = main_req_cfg->bb;
    }
    else {
        req_cfg->bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
    }

    ap_set_core_module_config(r->request_config, req_cfg);

    return OK;
}

static int core_create_proxy_req(request_rec *r, request_rec *pr)
{
    return core_create_req(pr);
}

static conn_rec *core_create_conn(apr_pool_t *ptrans, server_rec *s,
                                  apr_socket_t *csd, long id, void *sbh,
                                  apr_bucket_alloc_t *alloc)
{
    apr_status_t rv;
    apr_pool_t *pool;
    conn_rec *c = (conn_rec *) apr_pcalloc(ptrans, sizeof(conn_rec));
    core_server_config *sconf = ap_get_core_module_config(s->module_config);

    c->sbh = sbh;
    ap_update_child_status(c->sbh, SERVER_BUSY_READ, NULL);

    /* Got a connection structure, so initialize what fields we can
     * (the rest are zeroed out by pcalloc).
     */
    apr_pool_create(&pool, ptrans);
    apr_pool_tag(pool, "master_conn");
    c->pool = pool;

    c->conn_config = ap_create_conn_config(c->pool);
    c->notes = apr_table_make(c->pool, 5);
    c->slaves = apr_array_make(c->pool, 20, sizeof(conn_slave_rec *));
    c->requests = apr_array_make(c->pool, 20, sizeof(request_rec *));


    if ((rv = apr_socket_addr_get(&c->local_addr, APR_LOCAL, csd))
        != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_INFO, rv, s, APLOGNO(00137)
                     "apr_socket_addr_get(APR_LOCAL)");
        apr_socket_close(csd);
        return NULL;
    }

    apr_sockaddr_ip_get(&c->local_ip, c->local_addr);
    if ((rv = apr_socket_addr_get(&c->client_addr, APR_REMOTE, csd))
        != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_INFO, rv, s, APLOGNO(00138)
                     "apr_socket_addr_get(APR_REMOTE)");
        apr_socket_close(csd);
        return NULL;
    }

    apr_sockaddr_ip_get(&c->client_ip, c->client_addr);
    c->base_server = s;

    c->id = id;
    c->bucket_alloc = alloc;
    c->empty = apr_brigade_create(c->pool, c->bucket_alloc);
    c->filters = apr_hash_make(c->pool);
    c->async_filter = sconf->async_filter;

    c->clogging_input_filters = 0;

    if (sconf->conn_log_level) {
        int i;
        conn_log_config *conf;
        const struct ap_logconf *log = NULL;
        struct ap_logconf *merged;

        for (i = 0; i < sconf->conn_log_level->nelts; i++) {
            conf = APR_ARRAY_IDX(sconf->conn_log_level, i, conn_log_config *);
            if (apr_ipsubnet_test(conf->subnet, c->client_addr))
                log = &conf->log;
        }
        if (log) {
            merged = ap_new_log_config(c->pool, log);
            ap_merge_log_config(&s->log, merged);
            c->log = merged;
        }
    }

    return c;
}

static int core_pre_connection(conn_rec *c, void *csd)
{
    core_net_rec *net = apr_palloc(c->pool, sizeof(*net));
    apr_status_t rv;

    /* The Nagle algorithm says that we should delay sending partial
     * packets in hopes of getting more data.  We don't want to do
     * this; we are not telnet.  There are bad interactions between
     * persistent connections and Nagle's algorithm that have very severe
     * performance penalties.  (Failing to disable Nagle is not much of a
     * problem with simple HTTP.)
     */
    rv = apr_socket_opt_set(csd, APR_TCP_NODELAY, 1);
    if (rv != APR_SUCCESS && rv != APR_ENOTIMPL) {
        /* expected cause is that the client disconnected already,
         * hence the debug level
         */
        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c, APLOGNO(00139)
                      "apr_socket_opt_set(APR_TCP_NODELAY)");
    }

    /* The core filter requires the timeout mode to be set, which
     * incidentally sets the socket to be nonblocking.  If this
     * is not initialized correctly, Linux - for example - will
     * be initially blocking, while Solaris will be non blocking
     * and any initial read will fail.
     */
    rv = apr_socket_timeout_set(csd, c->base_server->timeout);
    if (rv != APR_SUCCESS) {
        /* expected cause is that the client disconnected already */
        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c, APLOGNO(00140)
                      "apr_socket_timeout_set");
    }

    net->c = c;
    net->in_ctx = NULL;
    net->out_ctx = NULL;
    net->client_socket = csd;

    ap_set_core_module_config(net->c->conn_config, csd);
    /* only the master connection talks to the network */
    if (c->master == NULL) {
        ap_add_input_filter_handle(ap_core_input_filter_handle, net, NULL,
                                   net->c);
        ap_add_output_filter_handle(ap_core_output_filter_handle, net, NULL,
                                    net->c);
    }
    return DONE;
}

AP_CORE_DECLARE(conn_rec *) ap_create_slave_connection(conn_rec *c)
{
    apr_pool_t *pool;
    conn_slave_rec *new;
    conn_rec *sc = (conn_rec *) apr_palloc(c->pool, sizeof(conn_rec));

    apr_pool_create(&pool, c->pool);
    apr_pool_tag(pool, "slave_conn");
    memcpy(sc, c, sizeof(conn_rec));
    sc->slaves = NULL;
    sc->master = c;
    sc->input_filters = NULL;
    sc->output_filters = NULL;
    sc->pool = pool;
    new = apr_array_push(c->slaves);
    new->c = sc;
    return sc;
}

AP_DECLARE(int) ap_state_query(int query)
{
    switch (query) {
    case AP_SQ_MAIN_STATE:
        return ap_main_state;
    case AP_SQ_RUN_MODE:
        return ap_run_mode;
    case AP_SQ_CONFIG_GEN:
        return ap_config_generation;
    default:
        return AP_SQ_NOT_SUPPORTED;
    }
}

static apr_random_t *rng = NULL;
#if APR_HAS_THREADS
static apr_thread_mutex_t *rng_mutex = NULL;
#endif

static void core_child_init(apr_pool_t *pchild, server_rec *s)
{
    apr_proc_t proc;
#if APR_HAS_THREADS
    int threaded_mpm;
    if (ap_mpm_query(AP_MPMQ_IS_THREADED, &threaded_mpm) == APR_SUCCESS
        && threaded_mpm)
    {
        apr_thread_mutex_create(&rng_mutex, APR_THREAD_MUTEX_DEFAULT, pchild);
    }
#endif
    /* The MPMs use plain fork() and not apr_proc_fork(), so we have to call
     * apr_random_after_fork() manually in the child
     */
    proc.pid = getpid();
    apr_random_after_fork(&proc);
}

static void core_optional_fn_retrieve(void)
{
    ap_init_scoreboard(NULL);
}

AP_CORE_DECLARE(void) ap_random_parent_after_fork(void)
{
    /*
     * To ensure that the RNG state in the parent changes after the fork, we
     * pull some data from the RNG and discard it. This ensures that the RNG
     * states in the children are different even after the pid wraps around.
     * As we only use apr_random for insecure random bytes, pulling 2 bytes
     * should be enough.
     * XXX: APR should probably have some dedicated API to do this, but it
     * XXX: currently doesn't.
     */
    apr_uint16_t data;
    apr_random_insecure_bytes(rng, &data, sizeof(data));
}

AP_CORE_DECLARE(void) ap_init_rng(apr_pool_t *p)
{
    unsigned char seed[8];
    apr_status_t rv;
    rng = apr_random_standard_new(p);
    do {
        rv = apr_generate_random_bytes(seed, sizeof(seed));
        if (rv != APR_SUCCESS)
            goto error;
        apr_random_add_entropy(rng, seed, sizeof(seed));
        rv = apr_random_insecure_ready(rng);
    } while (rv == APR_ENOTENOUGHENTROPY);
    if (rv == APR_SUCCESS)
        return;
error:
    ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(00141)
                 "Could not initialize random number generator");
    exit(1);
}

AP_DECLARE(void) ap_random_insecure_bytes(void *buf, apr_size_t size)
{
#if APR_HAS_THREADS
    if (rng_mutex)
        apr_thread_mutex_lock(rng_mutex);
#endif
    /* apr_random_insecure_bytes can only fail with APR_ENOTENOUGHENTROPY,
     * and we have ruled that out during initialization. Therefore we don't
     * need to check the return code.
     */
    apr_random_insecure_bytes(rng, buf, size);
#if APR_HAS_THREADS
    if (rng_mutex)
        apr_thread_mutex_unlock(rng_mutex);
#endif
}

/*
 * Finding a random number in a range.
 *      n' = a + n(b-a+1)/(M+1)
 * where:
 *      n' = random number in range
 *      a  = low end of range
 *      b  = high end of range
 *      n  = random number of 0..M
 *      M  = maxint
 * Algorithm 'borrowed' from PHP's rand() function.
 */
#define RAND_RANGE(__n, __min, __max, __tmax) \
(__n) = (__min) + (long) ((double) ((__max) - (__min) + 1.0) * ((__n) / ((__tmax) + 1.0)))
AP_DECLARE(apr_uint32_t) ap_random_pick(apr_uint32_t min, apr_uint32_t max)
{
    apr_uint32_t number;
#if (!__GNUC__ || __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8) || \
     !__sparc__ || APR_SIZEOF_VOIDP != 8)
    /* This triggers a gcc bug on sparc/64bit with gcc < 4.8, PR 52900 */
    if (max < 16384) {
        apr_uint16_t num16;
        ap_random_insecure_bytes(&num16, sizeof(num16));
        RAND_RANGE(num16, min, max, APR_UINT16_MAX);
        number = num16;
    }
    else
#endif
    {
        ap_random_insecure_bytes(&number, sizeof(number));
        RAND_RANGE(number, min, max, APR_UINT32_MAX);
    }
    return number;
}

static apr_status_t core_insert_network_bucket(conn_rec *c,
                                               apr_bucket_brigade *bb,
                                               apr_socket_t *socket)
{
    apr_bucket *e = apr_bucket_socket_create(socket, c->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(bb, e);
    return APR_SUCCESS;
}

static apr_status_t core_dirwalk_stat(apr_finfo_t *finfo, request_rec *r,
                                      apr_int32_t wanted) 
{
    return apr_stat(finfo, r->filename, wanted, r->pool);
}

static void core_dump_config(apr_pool_t *p, server_rec *s)
{
    core_server_config *sconf = ap_get_core_module_config(s->module_config);
    apr_file_t *out = NULL;
    const char *tmp;
    const char **defines;
    int i;
    if (!ap_exists_config_define("DUMP_RUN_CFG"))
        return;

    apr_file_open_stdout(&out, p);
    apr_file_printf(out, "ServerRoot: \"%s\"\n", ap_server_root);
    tmp = ap_server_root_relative(p, sconf->ap_document_root);
    apr_file_printf(out, "Main DocumentRoot: \"%s\"\n", tmp);
    if (s->error_fname[0] != '|' && s->errorlog_provider == NULL)
        tmp = ap_server_root_relative(p, s->error_fname);
    else
        tmp = s->error_fname;
    apr_file_printf(out, "Main ErrorLog: \"%s\"\n", tmp);
    if (ap_scoreboard_fname) {
        tmp = ap_runtime_dir_relative(p, ap_scoreboard_fname);
        apr_file_printf(out, "ScoreBoardFile: \"%s\"\n", tmp);
    }
    ap_dump_mutexes(p, s, out);
    ap_mpm_dump_pidfile(p, out);

    defines = (const char **)ap_server_config_defines->elts;
    for (i = 0; i < ap_server_config_defines->nelts; i++) {
        const char *name = defines[i];
        const char *val = NULL;
        if (server_config_defined_vars)
           val = apr_table_get(server_config_defined_vars, name);
        if (val)
            apr_file_printf(out, "Define: %s=%s\n", name, val);
        else
            apr_file_printf(out, "Define: %s\n", name);
    }
}

static int core_upgrade_handler(request_rec *r)
{
    conn_rec *c = r->connection;
    const char *upgrade;

    if (c->master) {
        /* Not possible to perform an HTTP/1.1 upgrade from a slave
         * connection. */
        return DECLINED;
    }
    
    upgrade = apr_table_get(r->headers_in, "Upgrade");
    if (upgrade && *upgrade) {
        const char *conn = apr_table_get(r->headers_in, "Connection");
        if (ap_find_token(r->pool, conn, "upgrade")) {
            apr_array_header_t *offers = NULL;
            const char *err;
            
            err = ap_parse_token_list_strict(r->pool, upgrade, &offers, 0);
            if (err) {
                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02910)
                              "parsing Upgrade header: %s", err);
                return DECLINED;
            }
            
            if (offers && offers->nelts > 0) {
                const char *protocol = ap_select_protocol(c, r, NULL, offers);
                if (protocol && strcmp(protocol, ap_get_protocol(c))) {
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02909)
                                  "Upgrade selects '%s'", protocol);
                    /* Let the client know what we are upgrading to. */
                    apr_table_clear(r->headers_out);
                    apr_table_setn(r->headers_out, "Upgrade", protocol);
                    apr_table_setn(r->headers_out, "Connection", "Upgrade");
                    
                    r->status = HTTP_SWITCHING_PROTOCOLS;
                    r->status_line = ap_get_status_line(r->status);
                    ap_send_interim_response(r, 1);

                    ap_switch_protocol(c, r, r->server, protocol);

                    /* make sure httpd closes the connection after this */
                    c->keepalive = AP_CONN_CLOSE;
                    return DONE;
                }
            }
        }
    }
    else if (!c->keepalives) {
        /* first request on a master connection, if we have protocols other
         * than the current one enabled here, announce them to the
         * client. If the client is already talking a protocol with requests
         * on slave connections, leave it be. */
        const apr_array_header_t *upgrades;
        ap_get_protocol_upgrades(c, r, NULL, 0, &upgrades);
        if (upgrades && upgrades->nelts > 0) {
            char *protocols = apr_array_pstrcat(r->pool, upgrades, ',');
            apr_table_setn(r->headers_out, "Upgrade", protocols);
            apr_table_setn(r->headers_out, "Connection", "Upgrade");
        }
    }
    
    return DECLINED;
}

static int core_upgrade_storage(request_rec *r)
{
    if ((r->method_number == M_OPTIONS) && r->uri && (r->uri[0] == '*') &&
        (r->uri[1] == '\0')) {
        return core_upgrade_handler(r);
    }
    return DECLINED;
}

static void register_hooks(apr_pool_t *p)
{
    errorlog_hash = apr_hash_make(p);
    ap_register_log_hooks(p);
    ap_register_config_hooks(p);
    ap_expr_init(p);

    /* create_connection and pre_connection should always be hooked
     * APR_HOOK_REALLY_LAST by core to give other modules the opportunity
     * to install alternate network transports and stop other functions
     * from being run.
     */
    ap_hook_create_connection(core_create_conn, NULL, NULL,
                              APR_HOOK_REALLY_LAST);
    ap_hook_pre_connection(core_pre_connection, NULL, NULL,
                           APR_HOOK_REALLY_LAST);

    ap_hook_pre_config(core_pre_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
    ap_hook_post_config(core_post_config,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_check_config(core_check_config,NULL,NULL,APR_HOOK_FIRST);
    ap_hook_test_config(core_dump_config,NULL,NULL,APR_HOOK_FIRST);
    ap_hook_translate_name(ap_core_translate,NULL,NULL,APR_HOOK_REALLY_LAST);
    ap_hook_map_to_storage(core_upgrade_storage,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_map_to_storage(core_map_to_storage,NULL,NULL,APR_HOOK_REALLY_LAST);
    ap_hook_open_logs(ap_open_logs,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_child_init(core_child_init,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_child_init(ap_logs_child_init,NULL,NULL,APR_HOOK_MIDDLE);
    ap_hook_handler(core_upgrade_handler,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_handler(default_handler,NULL,NULL,APR_HOOK_REALLY_LAST);
    /* FIXME: I suspect we can eliminate the need for these do_nothings - Ben */
    ap_hook_type_checker(do_nothing,NULL,NULL,APR_HOOK_REALLY_LAST);
    ap_hook_fixups(core_override_type,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_create_request(core_create_req, NULL, NULL, APR_HOOK_MIDDLE);
    APR_OPTIONAL_HOOK(proxy, create_req, core_create_proxy_req, NULL, NULL,
                      APR_HOOK_MIDDLE);
    ap_hook_pre_mpm(ap_create_scoreboard, NULL, NULL, APR_HOOK_MIDDLE);
    ap_hook_child_status(ap_core_child_status, NULL, NULL, APR_HOOK_MIDDLE);
    ap_hook_insert_network_bucket(core_insert_network_bucket, NULL, NULL,
                                  APR_HOOK_REALLY_LAST);
    ap_hook_dirwalk_stat(core_dirwalk_stat, NULL, NULL, APR_HOOK_REALLY_LAST);
    ap_hook_open_htaccess(ap_open_htaccess, NULL, NULL, APR_HOOK_REALLY_LAST);
    ap_hook_optional_fn_retrieve(core_optional_fn_retrieve, NULL, NULL,
                                 APR_HOOK_MIDDLE);
    ap_hook_output_pending(ap_filter_output_pending, NULL, NULL,
            APR_HOOK_MIDDLE);

    /* register the core's insert_filter hook and register core-provided
     * filters
     */
    ap_hook_insert_filter(core_insert_filter, NULL, NULL, APR_HOOK_MIDDLE);

    ap_core_input_filter_handle =
        ap_register_input_filter("CORE_IN", ap_core_input_filter,
                                 NULL, AP_FTYPE_NETWORK);
    ap_content_length_filter_handle =
        ap_register_output_filter("CONTENT_LENGTH", ap_content_length_filter,
                                  NULL, AP_FTYPE_PROTOCOL);
    ap_core_output_filter_handle =
        ap_register_output_filter("CORE", ap_core_output_filter,
                                  NULL, AP_FTYPE_NETWORK);
    ap_request_core_filter_handle =
        ap_register_output_filter("REQ_CORE", ap_request_core_filter,
                                  NULL, AP_FTYPE_TRANSCODE);
    ap_subreq_core_filter_handle =
        ap_register_output_filter("SUBREQ_CORE", ap_sub_req_output_filter,
                                  NULL, AP_FTYPE_CONTENT_SET);
    ap_old_write_func =
        ap_register_output_filter("OLD_WRITE", ap_old_write_filter,
                                  NULL, AP_FTYPE_RESOURCE - 10);
}

AP_DECLARE_MODULE(core) = {
    MPM20_MODULE_STUFF,
    AP_PLATFORM_REWRITE_ARGS_HOOK, /* hook to run before apache parses args */
    create_core_dir_config,       /* create per-directory config structure */
    merge_core_dir_configs,       /* merge per-directory config structures */
    create_core_server_config,    /* create per-server config structure */
    merge_core_server_configs,    /* merge per-server config structures */
    core_cmds,                    /* command apr_table_t */
    register_hooks                /* register hooks */
};