httpd.h

/* 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.
 */

/**
 * @file httpd.h
 * @brief HTTP Daemon routines
 *
 * @defgroup APACHE Apache HTTP Server
 *
 * Top level group of which all other groups are a member
 * @{
 *
 * @defgroup APACHE_MODS Loadable modules
 *           Top level group for modules
 * @defgroup APACHE_OS Operating System Specific
 * @defgroup APACHE_INTERNAL Internal interfaces
 * @defgroup APACHE_CORE Core routines
 * @{
 * @defgroup APACHE_CORE_DAEMON HTTP Daemon Routine
 * @{
 */

#ifndef APACHE_HTTPD_H
#define APACHE_HTTPD_H

/* XXX - We need to push more stuff to other .h files, or even .c files, to
 * make this file smaller
 */

/* Headers in which EVERYONE has an interest... */
#include "ap_config.h"
#include "ap_mmn.h"

#include "ap_release.h"

#include "apr.h"
#include "apr_general.h"
#include "apr_tables.h"
#include "apr_pools.h"
#include "apr_time.h"
#include "apr_network_io.h"
#include "apr_buckets.h"
#include "apr_poll.h"
#include "apr_thread_proc.h"

#include "os.h"

#include "ap_regex.h"

#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif

/* Note: apr_uri.h is also included, see below */

#ifdef __cplusplus
extern "C" {
#endif

/* ----------------------------- config dir ------------------------------ */

/** Define this to be the default server home dir. Most things later in this
 * file with a relative pathname will have this added.
 */
#ifndef HTTPD_ROOT
#ifdef OS2
/** Set default for OS/2 file system */
#define HTTPD_ROOT "/os2httpd"
#elif defined(WIN32)
/** Set default for Windows file system */
#define HTTPD_ROOT "/apache"
#elif defined (NETWARE)
/** Set the default for NetWare */
#define HTTPD_ROOT "/apache"
#else
/** Set for all other OSs */
#define HTTPD_ROOT "/usr/local/apache"
#endif
#endif /* HTTPD_ROOT */

/*
 * --------- You shouldn't have to edit anything below this line ----------
 *
 * Any modifications to any defaults not defined above should be done in the
 * respective configuration file.
 *
 */

/**
 * Default location of documents.  Can be overridden by the DocumentRoot
 * directive.
 */
#ifndef DOCUMENT_LOCATION
#ifdef OS2
/* Set default for OS/2 file system */
#define DOCUMENT_LOCATION  HTTPD_ROOT "/docs"
#else
/* Set default for non OS/2 file system */
#define DOCUMENT_LOCATION  HTTPD_ROOT "/htdocs"
#endif
#endif /* DOCUMENT_LOCATION */

/** Maximum number of dynamically loaded modules */
#ifndef DYNAMIC_MODULE_LIMIT
#define DYNAMIC_MODULE_LIMIT 256
#endif

/** Default administrator's address */
#define DEFAULT_ADMIN "[no address given]"

/** The name of the log files */
#ifndef DEFAULT_ERRORLOG
#if defined(OS2) || defined(WIN32)
#define DEFAULT_ERRORLOG "logs/error.log"
#else
#define DEFAULT_ERRORLOG "logs/error_log"
#endif
#endif /* DEFAULT_ERRORLOG */

/** Define this to be what your per-directory security files are called */
#ifndef DEFAULT_ACCESS_FNAME
#ifdef OS2
/* Set default for OS/2 file system */
#define DEFAULT_ACCESS_FNAME "htaccess"
#else
#define DEFAULT_ACCESS_FNAME ".htaccess"
#endif
#endif /* DEFAULT_ACCESS_FNAME */

/** The name of the server config file */
#ifndef SERVER_CONFIG_FILE
#define SERVER_CONFIG_FILE "conf/httpd.conf"
#endif

/** The default path for CGI scripts if none is currently set */
#ifndef DEFAULT_PATH
#define DEFAULT_PATH "/bin:/usr/bin:/usr/ucb:/usr/bsd:/usr/local/bin"
#endif

/** The path to the suExec wrapper, can be overridden in Configuration */
#ifndef SUEXEC_BIN
#define SUEXEC_BIN  HTTPD_ROOT "/bin/suexec"
#endif

/** The timeout for waiting for messages */
#ifndef DEFAULT_TIMEOUT
#define DEFAULT_TIMEOUT 60
#endif

/** The timeout for waiting for keepalive timeout until next request */
#ifndef DEFAULT_KEEPALIVE_TIMEOUT
#define DEFAULT_KEEPALIVE_TIMEOUT 5
#endif

/** The number of requests to entertain per connection */
#ifndef DEFAULT_KEEPALIVE
#define DEFAULT_KEEPALIVE 100
#endif

/*
 * Limits on the size of various request items.  These limits primarily
 * exist to prevent simple denial-of-service attacks on a server based
 * on misuse of the protocol.  The recommended values will depend on the
 * nature of the server resources -- CGI scripts and database backends
 * might require large values, but most servers could get by with much
 * smaller limits than we use below.  The request message body size can
 * be limited by the per-dir config directive LimitRequestBody.
 *
 * Internal buffer sizes are two bytes more than the DEFAULT_LIMIT_REQUEST_LINE
 * and DEFAULT_LIMIT_REQUEST_FIELDSIZE below, which explains the 8190.
 * These two limits can be lowered or raised by the server config
 * directives LimitRequestLine and LimitRequestFieldsize, respectively.
 *
 * DEFAULT_LIMIT_REQUEST_FIELDS can be modified or disabled (set = 0) by
 * the server config directive LimitRequestFields.
 */

/** default limit on bytes in Request-Line (Method+URI+HTTP-version) */
#ifndef DEFAULT_LIMIT_REQUEST_LINE
#define DEFAULT_LIMIT_REQUEST_LINE 8190
#endif
/** default limit on bytes in any one header field  */
#ifndef DEFAULT_LIMIT_REQUEST_FIELDSIZE
#define DEFAULT_LIMIT_REQUEST_FIELDSIZE 8190
#endif
/** default limit on number of request header fields */
#ifndef DEFAULT_LIMIT_REQUEST_FIELDS
#define DEFAULT_LIMIT_REQUEST_FIELDS 100
#endif
/** default/hard limit on number of leading/trailing empty lines */
#ifndef DEFAULT_LIMIT_BLANK_LINES
#define DEFAULT_LIMIT_BLANK_LINES 10
#endif

/**
 * The default default character set name to add if AddDefaultCharset is
 * enabled.  Overridden with AddDefaultCharsetName.
 */
#define DEFAULT_ADD_DEFAULT_CHARSET_NAME "iso-8859-1"

/** default HTTP Server protocol */
#define AP_SERVER_PROTOCOL "HTTP/1.1"


/* ------------------ stuff that modules are allowed to look at ----------- */

/** Define this to be what your HTML directory content files are called */
#ifndef AP_DEFAULT_INDEX
#define AP_DEFAULT_INDEX "index.html"
#endif

/** The name of the MIME types file */
#ifndef AP_TYPES_CONFIG_FILE
#define AP_TYPES_CONFIG_FILE "conf/mime.types"
#endif

/*
 * Define the HTML doctype strings centrally.
 */
/** HTML 2.0 Doctype */
#define DOCTYPE_HTML_2_0  "<!DOCTYPE HTML PUBLIC \"-//IETF//" \
                          "DTD HTML 2.0//EN\">\n"
/** HTML 3.2 Doctype */
#define DOCTYPE_HTML_3_2  "<!DOCTYPE HTML PUBLIC \"-//W3C//" \
                          "DTD HTML 3.2 Final//EN\">\n"
/** HTML 4.0 Strict Doctype */
#define DOCTYPE_HTML_4_0S "<!DOCTYPE HTML PUBLIC \"-//W3C//" \
                          "DTD HTML 4.0//EN\"\n" \
                          "\"http://www.w3.org/TR/REC-html40/strict.dtd\">\n"
/** HTML 4.0 Transitional Doctype */
#define DOCTYPE_HTML_4_0T "<!DOCTYPE HTML PUBLIC \"-//W3C//" \
                          "DTD HTML 4.0 Transitional//EN\"\n" \
                          "\"http://www.w3.org/TR/REC-html40/loose.dtd\">\n"
/** HTML 4.0 Frameset Doctype */
#define DOCTYPE_HTML_4_0F "<!DOCTYPE HTML PUBLIC \"-//W3C//" \
                          "DTD HTML 4.0 Frameset//EN\"\n" \
                          "\"http://www.w3.org/TR/REC-html40/frameset.dtd\">\n"
/** XHTML 1.0 Strict Doctype */
#define DOCTYPE_XHTML_1_0S "<!DOCTYPE html PUBLIC \"-//W3C//" \
                           "DTD XHTML 1.0 Strict//EN\"\n" \
                           "\"http://www.w3.org/TR/xhtml1/DTD/" \
                           "xhtml1-strict.dtd\">\n"
/** XHTML 1.0 Transitional Doctype */
#define DOCTYPE_XHTML_1_0T "<!DOCTYPE html PUBLIC \"-//W3C//" \
                           "DTD XHTML 1.0 Transitional//EN\"\n" \
                           "\"http://www.w3.org/TR/xhtml1/DTD/" \
                           "xhtml1-transitional.dtd\">\n"
/** XHTML 1.0 Frameset Doctype */
#define DOCTYPE_XHTML_1_0F "<!DOCTYPE html PUBLIC \"-//W3C//" \
                           "DTD XHTML 1.0 Frameset//EN\"\n" \
                           "\"http://www.w3.org/TR/xhtml1/DTD/" \
                           "xhtml1-frameset.dtd\">"

/** Internal representation for a HTTP protocol number, e.g., HTTP/1.1 */
#define HTTP_VERSION(major,minor) (1000*(major)+(minor))
/** Major part of HTTP protocol */
#define HTTP_VERSION_MAJOR(number) ((number)/1000)
/** Minor part of HTTP protocol */
#define HTTP_VERSION_MINOR(number) ((number)%1000)

/* -------------- Port number for server running standalone --------------- */

/** default HTTP Port */
#define DEFAULT_HTTP_PORT       80
/** default HTTPS Port */
#define DEFAULT_HTTPS_PORT      443
/**
 * Check whether @a port is the default port for the request @a r.
 * @param port The port number
 * @param r The request
 * @see #ap_default_port
 */
#define ap_is_default_port(port,r)      ((port) == ap_default_port(r))
/**
 * Get the default port for a request (which depends on the scheme).
 * @param r The request
 */
#define ap_default_port(r)      ap_run_default_port(r)
/**
 * Get the scheme for a request.
 * @param r The request
 */
#define ap_http_scheme(r)       ap_run_http_scheme(r)

/** The default string length */
#define MAX_STRING_LEN HUGE_STRING_LEN

/** The length of a Huge string */
#define HUGE_STRING_LEN 8192

/** The size of the server's internal read-write buffers */
#define AP_IOBUFSIZE 8192

/** The max number of regex captures that can be expanded by ap_pregsub */
#define AP_MAX_REG_MATCH 10

/**
 * APR_HAS_LARGE_FILES introduces the problem of spliting sendfile into
 * multiple buckets, no greater than MAX(apr_size_t), and more granular
 * than that in case the brigade code/filters attempt to read it directly.
 * ### 16mb is an invention, no idea if it is reasonable.
 */
#define AP_MAX_SENDFILE 16777216  /* 2^24 */

/**
 * MPM child process exit status values
 * The MPM parent process may check the status to see if special
 * error handling is required.
 */
/** a normal exit */
#define APEXIT_OK               0x0
/** A fatal error arising during the server's init sequence */
#define APEXIT_INIT             0x2
/**  The child died during its init sequence */
#define APEXIT_CHILDINIT        0x3
/**
 *   The child exited due to a resource shortage.
 *   The parent should limit the rate of forking until
 *   the situation is resolved.
 */
#define APEXIT_CHILDSICK        0x7
/**
 *     A fatal error, resulting in the whole server aborting.
 *     If a child exits with this error, the parent process
 *     considers this a server-wide fatal error and aborts.
 */
#define APEXIT_CHILDFATAL       0xf

#ifndef AP_DECLARE
/**
 * Stuff marked #AP_DECLARE is part of the API, and intended for use
 * by modules. Its purpose is to allow us to add attributes that
 * particular platforms or compilers require to every exported function.
 */
# define AP_DECLARE(type)    type
#endif

#ifndef AP_DECLARE_NONSTD
/**
 * Stuff marked #AP_DECLARE_NONSTD is part of the API, and intended for
 * use by modules.  The difference between #AP_DECLARE and
 * #AP_DECLARE_NONSTD is that the latter is required for any functions
 * which use varargs or are used via indirect function call.  This
 * is to accommodate the two calling conventions in windows dlls.
 */
# define AP_DECLARE_NONSTD(type)    type
#endif
#ifndef AP_DECLARE_DATA
# define AP_DECLARE_DATA
#endif

#ifndef AP_MODULE_DECLARE
# define AP_MODULE_DECLARE(type)    type
#endif
#ifndef AP_MODULE_DECLARE_NONSTD
# define AP_MODULE_DECLARE_NONSTD(type)  type
#endif
#ifndef AP_MODULE_DECLARE_DATA
# define AP_MODULE_DECLARE_DATA
#endif

/**
 * @internal
 * modules should not use functions marked AP_CORE_DECLARE
 */
#ifndef AP_CORE_DECLARE
# define AP_CORE_DECLARE        AP_DECLARE
#endif

/**
 * @internal
 * modules should not use functions marked AP_CORE_DECLARE_NONSTD
 */

#ifndef AP_CORE_DECLARE_NONSTD
# define AP_CORE_DECLARE_NONSTD AP_DECLARE_NONSTD
#endif

/**
 * @defgroup APACHE_APR_STATUS_T HTTPD specific values of apr_status_t
 * @{
 */
#define AP_START_USERERR            (APR_OS_START_USERERR + 2000)
#define AP_USERERR_LEN              1000

/** The function declines to handle the request */
#define AP_DECLINED                 (AP_START_USERERR + 0)

/** @} */

/**
 * @brief The numeric version information is broken out into fields within this
 * structure.
 */
typedef struct {
    int major;              /**< major number */
    int minor;              /**< minor number */
    int patch;              /**< patch number */
    const char *add_string; /**< additional string like "-dev" */
} ap_version_t;

/**
 * Return httpd's version information in a numeric form.
 *
 *  @param version Pointer to a version structure for returning the version
 *                 information.
 */
AP_DECLARE(void) ap_get_server_revision(ap_version_t *version);

/**
 * Get the server banner in a form suitable for sending over the
 * network, with the level of information controlled by the
 * ServerTokens directive.
 * @return The server banner
 */
AP_DECLARE(const char *) ap_get_server_banner(void);

/**
 * Get the server description in a form suitable for local displays,
 * status reports, or logging.  This includes the detailed server
 * version and information about some modules.  It is not affected
 * by the ServerTokens directive.
 * @return The server description
 */
AP_DECLARE(const char *) ap_get_server_description(void);

/**
 * Add a component to the server description and banner strings
 * @param pconf The pool to allocate the component from
 * @param component The string to add
 */
AP_DECLARE(void) ap_add_version_component(apr_pool_t *pconf, const char *component);

/**
 * Get the date a time that the server was built
 * @return The server build time string
 */
AP_DECLARE(const char *) ap_get_server_built(void);

/* non-HTTP status codes returned by hooks */

#define OK 0                    /**< Module has handled this stage. */
#define DECLINED -1             /**< Module declines to handle */
#define DONE -2                 /**< Module has served the response completely
                                 *  - it's safe to die() with no more output
                                 */
#define SUSPENDED -3 /**< Module will handle the remainder of the request.
                      * The core will never invoke the request again, */

/** Returned by the bottom-most filter if no data was written.
 *  @see ap_pass_brigade(). */
#define AP_NOBODY_WROTE         -100
/** Returned by the bottom-most filter if no data was read.
 *  @see ap_get_brigade(). */
#define AP_NOBODY_READ          -101
/** Returned by any filter if the filter chain encounters an error
 *  and has already dealt with the error response.
 */
#define AP_FILTER_ERROR         -102

/**
 * @defgroup HTTP_Status HTTP Status Codes
 * @{
 */
/**
 * The size of the static status_lines array in http_protocol.c for
 * storing all of the potential response status-lines (a sparse table).
 * When adding a new code here add it to status_lines as well.
 * A future version should dynamically generate the apr_table_t at startup.
 */
#define RESPONSE_CODES 103

#define HTTP_CONTINUE                        100
#define HTTP_SWITCHING_PROTOCOLS             101
#define HTTP_PROCESSING                      102
#define HTTP_OK                              200
#define HTTP_CREATED                         201
#define HTTP_ACCEPTED                        202
#define HTTP_NON_AUTHORITATIVE               203
#define HTTP_NO_CONTENT                      204
#define HTTP_RESET_CONTENT                   205
#define HTTP_PARTIAL_CONTENT                 206
#define HTTP_MULTI_STATUS                    207
#define HTTP_ALREADY_REPORTED                208
#define HTTP_IM_USED                         226
#define HTTP_MULTIPLE_CHOICES                300
#define HTTP_MOVED_PERMANENTLY               301
#define HTTP_MOVED_TEMPORARILY               302
#define HTTP_SEE_OTHER                       303
#define HTTP_NOT_MODIFIED                    304
#define HTTP_USE_PROXY                       305
#define HTTP_TEMPORARY_REDIRECT              307
#define HTTP_PERMANENT_REDIRECT              308
#define HTTP_BAD_REQUEST                     400
#define HTTP_UNAUTHORIZED                    401
#define HTTP_PAYMENT_REQUIRED                402
#define HTTP_FORBIDDEN                       403
#define HTTP_NOT_FOUND                       404
#define HTTP_METHOD_NOT_ALLOWED              405
#define HTTP_NOT_ACCEPTABLE                  406
#define HTTP_PROXY_AUTHENTICATION_REQUIRED   407
#define HTTP_REQUEST_TIME_OUT                408
#define HTTP_CONFLICT                        409
#define HTTP_GONE                            410
#define HTTP_LENGTH_REQUIRED                 411
#define HTTP_PRECONDITION_FAILED             412
#define HTTP_REQUEST_ENTITY_TOO_LARGE        413
#define HTTP_REQUEST_URI_TOO_LARGE           414
#define HTTP_UNSUPPORTED_MEDIA_TYPE          415
#define HTTP_RANGE_NOT_SATISFIABLE           416
#define HTTP_EXPECTATION_FAILED              417
#define HTTP_MISDIRECTED_REQUEST             421
#define HTTP_UNPROCESSABLE_ENTITY            422
#define HTTP_LOCKED                          423
#define HTTP_FAILED_DEPENDENCY               424
#define HTTP_UPGRADE_REQUIRED                426
#define HTTP_PRECONDITION_REQUIRED           428
#define HTTP_TOO_MANY_REQUESTS               429
#define HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE 431
#define HTTP_UNAVAILABLE_FOR_LEGAL_REASONS   451
#define HTTP_INTERNAL_SERVER_ERROR           500
#define HTTP_NOT_IMPLEMENTED                 501
#define HTTP_BAD_GATEWAY                     502
#define HTTP_SERVICE_UNAVAILABLE             503
#define HTTP_GATEWAY_TIME_OUT                504
#define HTTP_VERSION_NOT_SUPPORTED           505
#define HTTP_VARIANT_ALSO_VARIES             506
#define HTTP_INSUFFICIENT_STORAGE            507
#define HTTP_LOOP_DETECTED                   508
#define HTTP_NOT_EXTENDED                    510
#define HTTP_NETWORK_AUTHENTICATION_REQUIRED 511

/** is the status code informational */
#define ap_is_HTTP_INFO(x)         (((x) >= 100)&&((x) < 200))
/** is the status code OK ?*/
#define ap_is_HTTP_SUCCESS(x)      (((x) >= 200)&&((x) < 300))
/** is the status code a redirect */
#define ap_is_HTTP_REDIRECT(x)     (((x) >= 300)&&((x) < 400))
/** is the status code a error (client or server) */
#define ap_is_HTTP_ERROR(x)        (((x) >= 400)&&((x) < 600))
/** is the status code a client error  */
#define ap_is_HTTP_CLIENT_ERROR(x) (((x) >= 400)&&((x) < 500))
/** is the status code a server error  */
#define ap_is_HTTP_SERVER_ERROR(x) (((x) >= 500)&&((x) < 600))
/** is the status code a (potentially) valid response code?  */
#define ap_is_HTTP_VALID_RESPONSE(x) (((x) >= 100)&&((x) < 600))

/** should the status code drop the connection */
#define ap_status_drops_connection(x) \
                                   (((x) == HTTP_BAD_REQUEST)           || \
                                    ((x) == HTTP_REQUEST_TIME_OUT)      || \
                                    ((x) == HTTP_LENGTH_REQUIRED)       || \
                                    ((x) == HTTP_REQUEST_ENTITY_TOO_LARGE) || \
                                    ((x) == HTTP_REQUEST_URI_TOO_LARGE) || \
                                    ((x) == HTTP_INTERNAL_SERVER_ERROR) || \
                                    ((x) == HTTP_SERVICE_UNAVAILABLE) || \
                                    ((x) == HTTP_NOT_IMPLEMENTED))
/** @} */

/**
 * @defgroup Methods List of Methods recognized by the server
 * @ingroup APACHE_CORE_DAEMON
 * @{
 *
 * @brief Methods recognized (but not necessarily handled) by the server.
 *
 * These constants are used in bit shifting masks of size int, so it is
 * unsafe to have more methods than bits in an int.  HEAD == M_GET.
 * This list must be tracked by the list in http_protocol.c in routine
 * ap_method_name_of().
 *
 */

#define M_GET                   0       /** RFC 2616: HTTP */
#define M_PUT                   1       /*  :             */
#define M_POST                  2
#define M_DELETE                3
#define M_CONNECT               4
#define M_OPTIONS               5
#define M_TRACE                 6       /** RFC 2616: HTTP */
#define M_PATCH                 7       /** no rfc(!)  ### remove this one? */
#define M_PROPFIND              8       /** RFC 2518: WebDAV */
#define M_PROPPATCH             9       /*  :               */
#define M_MKCOL                 10
#define M_COPY                  11
#define M_MOVE                  12
#define M_LOCK                  13
#define M_UNLOCK                14      /** RFC 2518: WebDAV */
#define M_VERSION_CONTROL       15      /** RFC 3253: WebDAV Versioning */
#define M_CHECKOUT              16      /*  :                          */
#define M_UNCHECKOUT            17
#define M_CHECKIN               18
#define M_UPDATE                19
#define M_LABEL                 20
#define M_REPORT                21
#define M_MKWORKSPACE           22
#define M_MKACTIVITY            23
#define M_BASELINE_CONTROL      24
#define M_MERGE                 25
#define M_INVALID               26      /** no valid method */

/**
 * METHODS needs to be equal to the number of bits
 * we are using for limit masks.
 */
#define METHODS     64

/**
 * The method mask bit to shift for anding with a bitmask.
 */
#define AP_METHOD_BIT ((apr_int64_t)1)
/** @} */


/** @see ap_method_list_t */
typedef struct ap_method_list_t ap_method_list_t;

/**
 * @struct ap_method_list_t
 * @brief  Structure for handling HTTP methods.
 *
 * Methods known to the server are accessed via a bitmask shortcut;
 * extension methods are handled by an array.
 */
struct ap_method_list_t {
    /** The bitmask used for known methods */
    apr_int64_t method_mask;
    /** the array used for extension methods */
    apr_array_header_t *method_list;
};

/**
 * @defgroup module_magic Module Magic mime types
 * @{
 */
/** Magic for mod_cgi[d] */
#define CGI_MAGIC_TYPE "application/x-httpd-cgi"
/** Magic for mod_include */
#define INCLUDES_MAGIC_TYPE "text/x-server-parsed-html"
/** Magic for mod_include */
#define INCLUDES_MAGIC_TYPE3 "text/x-server-parsed-html3"
/** Magic for mod_dir */
#define DIR_MAGIC_TYPE "httpd/unix-directory"
/** Default for r->handler if no content-type set by type_checker */
#define AP_DEFAULT_HANDLER_NAME ""
#define AP_IS_DEFAULT_HANDLER_NAME(x) (*x == '\0')

/** @} */
/* Just in case your linefeed isn't the one the other end is expecting. */
#if !APR_CHARSET_EBCDIC
/** linefeed */
#define LF 10
/** carrige return */
#define CR 13
/** carrige return /Line Feed Combo */
#define CRLF "\015\012"
#else /* APR_CHARSET_EBCDIC */
/* For platforms using the EBCDIC charset, the transition ASCII->EBCDIC is done
 * in the buff package (bread/bputs/bwrite).  Everywhere else, we use
 * "native EBCDIC" CR and NL characters. These are therefore
 * defined as
 * '\r' and '\n'.
 */
#define CR '\r'
#define LF '\n'
#define CRLF "\r\n"
#endif /* APR_CHARSET_EBCDIC */
/** Useful for common code with either platform charset. */
#define CRLF_ASCII "\015\012"

/**
 * @defgroup values_request_rec_body Possible values for request_rec.read_body
 * @{
 * Possible values for request_rec.read_body (set by handling module):
 */

/** Send 413 error if message has any body */
#define REQUEST_NO_BODY          0
/** Send 411 error if body without Content-Length */
#define REQUEST_CHUNKED_ERROR    1
/** If chunked, remove the chunks for me. */
#define REQUEST_CHUNKED_DECHUNK  2
/** @} // values_request_rec_body */

/**
 * @defgroup values_request_rec_used_path_info Possible values for request_rec.used_path_info
 * @ingroup APACHE_CORE_DAEMON
 * @{
 * Possible values for request_rec.used_path_info:
 */

/** Accept the path_info from the request */
#define AP_REQ_ACCEPT_PATH_INFO    0
/** Return a 404 error if path_info was given */
#define AP_REQ_REJECT_PATH_INFO    1
/** Module may chose to use the given path_info */
#define AP_REQ_DEFAULT_PATH_INFO   2

/** @} // values_request_rec_used_path_info */


/*
 * Things which may vary per file-lookup WITHIN a request ---
 * e.g., state of MIME config.  Basically, the name of an object, info
 * about the object, and any other info we may ahve which may need to
 * change as we go poking around looking for it (e.g., overridden by
 * .htaccess files).
 *
 * Note how the default state of almost all these things is properly
 * zero, so that allocating it with pcalloc does the right thing without
 * a whole lot of hairy initialization... so long as we are willing to
 * make the (fairly) portable assumption that the bit pattern of a NULL
 * pointer is, in fact, zero.
 */

/**
 * @brief This represents the result of calling htaccess; these are cached for
 * each request.
 */
struct htaccess_result {
    /** the directory to which this applies */
    const char *dir;
    /** the overrides allowed for the .htaccess file */
    int override;
    /** the override options allowed for the .htaccess file */
    int override_opts;
    /** Table of allowed directives for override */
    apr_table_t *override_list;
    /** the configuration directives */
    struct ap_conf_vector_t *htaccess;
    /** the next one, or NULL if no more; N.B. never change this */
    const struct htaccess_result *next;
};

/* The following four types define a hierarchy of activities, so that
 * given a request_rec r you can write r->connection->server->process
 * to get to the process_rec.  While this reduces substantially the
 * number of arguments that various hooks require beware that in
 * threaded versions of the server you must consider multiplexing
 * issues.  */


/** A structure that represents one process */
typedef struct process_rec process_rec;
/** A structure that represents a virtual server */
typedef struct server_rec server_rec;
/** A structure that represents one connection */
typedef struct conn_rec conn_rec;
/** A structure that represents the current request */
typedef struct request_rec request_rec;
/** A structure that represents the status of the current connection */
typedef struct conn_state_t conn_state_t;

/* ### would be nice to not include this from httpd.h ... */
/* This comes after we have defined the request_rec type */
#include "apr_uri.h"

/**
 * @brief A structure that represents one process
 */
struct process_rec {
    /** Global pool. Cleared upon normal exit */
    apr_pool_t *pool;
    /** Configuration pool. Cleared upon restart */
    apr_pool_t *pconf;
    /** The program name used to execute the program */
    const char *short_name;
    /** The command line arguments */
    const char * const *argv;
    /** Number of command line arguments passed to the program */
    int argc;
};

/**
 * @brief A structure that represents the current request
 */
struct request_rec {
    /** The pool associated with the request */
    apr_pool_t *pool;
    /** The connection to the client */
    conn_rec *connection;
    /** The virtual host for this request */
    server_rec *server;

    /** Pointer to the redirected request if this is an external redirect */
    request_rec *next;
    /** Pointer to the previous request if this is an internal redirect */
    request_rec *prev;

    /** Pointer to the main request if this is a sub-request
     * (see http_request.h) */
    request_rec *main;

    /* Info about the request itself... we begin with stuff that only
     * protocol.c should ever touch...
     */
    /** First line of request */
    char *the_request;
    /** HTTP/0.9, "simple" request (e.g. GET /foo\n w/no headers) */
    int assbackwards;
    /** A proxy request (calculated during post_read_request/translate_name)
     *  possible values PROXYREQ_NONE, PROXYREQ_PROXY, PROXYREQ_REVERSE,
     *                  PROXYREQ_RESPONSE
     */
    int proxyreq;
    /** HEAD request, as opposed to GET */
    int header_only;
    /** Protocol version number of protocol; 1.1 = 1001 */
    int proto_num;
    /** Protocol string, as given to us, or HTTP/0.9 */
    char *protocol;
    /** Host, as set by full URI or Host: */
    const char *hostname;

    /** Time when the request started */
    apr_time_t request_time;

    /** Status line, if set by script */
    const char *status_line;
    /** Status line */
    int status;

    /* Request method, two ways; also, protocol, etc..  Outside of protocol.c,
     * look, but don't touch.
     */

    /** M_GET, M_POST, etc. */
    int method_number;
    /** Request method (eg. GET, HEAD, POST, etc.) */
    const char *method;

    /**
     *  'allowed' is a bitvector of the allowed methods.
     *
     *  A handler must ensure that the request method is one that
     *  it is capable of handling.  Generally modules should DECLINE
     *  any request methods they do not handle.  Prior to aborting the
     *  handler like this the handler should set r->allowed to the list
     *  of methods that it is willing to handle.  This bitvector is used
     *  to construct the "Allow:" header required for OPTIONS requests,
     *  and HTTP_METHOD_NOT_ALLOWED and HTTP_NOT_IMPLEMENTED status codes.
     *
     *  Since the default_handler deals with OPTIONS, all modules can
     *  usually decline to deal with OPTIONS.  TRACE is always allowed,
     *  modules don't need to set it explicitly.
     *
     *  Since the default_handler will always handle a GET, a
     *  module which does *not* implement GET should probably return
     *  HTTP_METHOD_NOT_ALLOWED.  Unfortunately this means that a Script GET
     *  handler can't be installed by mod_actions.
     */
    apr_int64_t allowed;
    /** Array of extension methods */
    apr_array_header_t *allowed_xmethods;
    /** List of allowed methods */
    ap_method_list_t *allowed_methods;

    /** byte count in stream is for body */
    apr_off_t sent_bodyct;
    /** body byte count, for easy access */
    apr_off_t bytes_sent;
    /** Last modified time of the requested resource */
    apr_time_t mtime;

    /* HTTP/1.1 connection-level features */

    /** The Range: header */
    const char *range;
    /** The "real" content length */
    apr_off_t clength;
    /** sending chunked transfer-coding */
    int chunked;

    /** Method for reading the request body
     * (eg. REQUEST_CHUNKED_ERROR, REQUEST_NO_BODY,
     *  REQUEST_CHUNKED_DECHUNK, etc...) */
    int read_body;
    /** reading chunked transfer-coding */
    int read_chunked;
    /** is client waiting for a 100 response? */
    unsigned expecting_100;
    /** The optional kept body of the request. */
    apr_bucket_brigade *kept_body;
    /** For ap_body_to_table(): parsed body */
    /* XXX: ap_body_to_table has been removed. Remove body_table too or
     * XXX: keep it to reintroduce ap_body_to_table without major bump? */
    apr_table_t *body_table;
    /** Remaining bytes left to read from the request body */
    apr_off_t remaining;
    /** Number of bytes that have been read  from the request body */
    apr_off_t read_length;

    /* MIME header environments, in and out.  Also, an array containing
     * environment variables to be passed to subprocesses, so people can
     * write modules to add to that environment.
     *
     * The difference between headers_out and err_headers_out is that the
     * latter are printed even on error, and persist across internal redirects
     * (so the headers printed for ErrorDocument handlers will have them).
     *
     * The 'notes' apr_table_t is for notes from one module to another, with no
     * other set purpose in mind...
     */

    /** MIME header environment from the request */
    apr_table_t *headers_in;
    /** MIME header environment for the response */
    apr_table_t *headers_out;
    /** MIME header environment for the response, printed even on errors and
     * persist across internal redirects */
    apr_table_t *err_headers_out;
    /** Array of environment variables to be used for sub processes */
    apr_table_t *subprocess_env;
    /** Notes from one module to another */
    apr_table_t *notes;

    /* content_type, handler, content_encoding, and all content_languages
     * MUST be lowercased strings.  They may be pointers to static strings;
     * they should not be modified in place.
     */
    /** The content-type for the current request */
    const char *content_type;   /* Break these out --- we dispatch on 'em */
    /** The handler string that we use to call a handler function */
    const char *handler;        /* What we *really* dispatch on */

    /** How to encode the data */
    const char *content_encoding;
    /** Array of strings representing the content languages */
    apr_array_header_t *content_languages;

    /** variant list validator (if negotiated) */
    char *vlist_validator;

    /** If an authentication check was made, this gets set to the user name. */
    char *user;
    /** If an authentication check was made, this gets set to the auth type. */
    char *ap_auth_type;

    /* What object is being requested (either directly, or via include
     * or content-negotiation mapping).
     */

    /** The URI without any parsing performed */
    char *unparsed_uri;
    /** The path portion of the URI, or "/" if no path provided */
    char *uri;
    /** The filename on disk corresponding to this response */
    char *filename;
    /** The true filename stored in the filesystem, as in the true alpha case
     *  and alias correction, e.g. "Image.jpeg" not "IMAGE$1.JPE" on Windows.
     *  The core map_to_storage canonicalizes r->filename when they mismatch */
    char *canonical_filename;
    /** The PATH_INFO extracted from this request */
    char *path_info;
    /** The QUERY_ARGS extracted from this request */
    char *args;

    /**
     * Flag for the handler to accept or reject path_info on
     * the current request.  All modules should respect the
     * AP_REQ_ACCEPT_PATH_INFO and AP_REQ_REJECT_PATH_INFO
     * values, while AP_REQ_DEFAULT_PATH_INFO indicates they
     * may follow existing conventions.  This is set to the
     * user's preference upon HOOK_VERY_FIRST of the fixups.
     */
    int used_path_info;

    /** A flag to determine if the eos bucket has been sent yet */
    int eos_sent;

    /* Various other config info which may change with .htaccess files
     * These are config vectors, with one void* pointer for each module
     * (the thing pointed to being the module's business).
     */

    /** Options set in config files, etc. */
    struct ap_conf_vector_t *per_dir_config;
    /** Notes on *this* request */
    struct ap_conf_vector_t *request_config;

    /** Optional request log level configuration. Will usually point
     *  to a server or per_dir config, i.e. must be copied before
     *  modifying */
    const struct ap_logconf *log;

    /** Id to identify request in access and error log. Set when the first
     *  error log entry for this request is generated.