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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
| commit | 6beeb1b708550be0d4a53b272283e17e5e35fe17 (patch) | |
| tree | 1ce8673d4aaa948e5554000101f46536a1e4cc29 /docs/manual/developer/new_api_2_4.html.en | |
| parent | Initial commit. (diff) | |
| download | apache2-6beeb1b708550be0d4a53b272283e17e5e35fe17.tar.xz apache2-6beeb1b708550be0d4a53b272283e17e5e35fe17.zip | |
Adding upstream version 2.4.57.upstream/2.4.57upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/manual/developer/new_api_2_4.html.en')
| -rw-r--r-- | docs/manual/developer/new_api_2_4.html.en | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/docs/manual/developer/new_api_2_4.html.en b/docs/manual/developer/new_api_2_4.html.en new file mode 100644 index 0000000..6354e85 --- /dev/null +++ b/docs/manual/developer/new_api_2_4.html.en @@ -0,0 +1,601 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head> +<meta content="text/html; charset=UTF-8" http-equiv="Content-Type" /> +<!-- + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + This file is generated from xml source: DO NOT EDIT + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + --> +<title>API Changes in Apache HTTP Server 2.4 since 2.2 - Apache HTTP Server Version 2.4</title> +<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> +<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> +<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" /> +<script src="../style/scripts/prettify.min.js" type="text/javascript"> +</script> + +<link href="../images/favicon.ico" rel="shortcut icon" /></head> +<body id="manual-page"><div id="page-header"> +<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p> +<p class="apache">Apache HTTP Server Version 2.4</p> +<img alt="" src="../images/feather.png" /></div> +<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div> +<div id="path"> +<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.4</a></div><div id="page-content"><div id="preamble"><h1>API Changes in Apache HTTP Server 2.4 since 2.2</h1> +<div class="toplang"> +<p><span>Available Languages: </span><a href="../en/developer/new_api_2_4.html" title="English"> en </a></p> +</div> + + <p>This document describes changes to the Apache HTTPD API from + version 2.2 to 2.4, that may be of interest to module/application + developers and core hacks. As of the first GA release of the + 2.4 branch API compatibility is preserved for the life of the + 2.4 branch. (The + <a href="http://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x/VERSIONING">VERSIONING</a> + description for the 2.4 release provides more information about API + compatibility.)</p> + + <p>API changes fall into two categories: APIs that are altogether new, + and existing APIs that are expanded or changed. The latter are + further divided into those where all changes are backwards-compatible + (so existing modules can ignore them), and those that might + require attention by maintainers. As with the transition from + HTTPD 2.0 to 2.2, existing modules and applications will require + recompiling and may call for some attention, but most should not + require any substantial updating (although some may be able to + take advantage of API changes to offer significant improvements).</p> + <p>For the purpose of this document, the API is split according + to the public header files. These headers are themselves the + reference documentation, and can be used to generate a browsable + HTML reference with <code>make docs</code>.</p> +</div> +<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#api_changes">Changed APIs</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#upgrading">Specific information on upgrading modules from 2.2</a></li> +</ul><h3>See also</h3><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="api_changes" id="api_changes">Changed APIs</a></h2> + + + <h3><a name="ap_expr" id="ap_expr">ap_expr (NEW!)</a></h3> + + <p>Introduces a new API to parse and evaluate boolean and algebraic + expressions, including provision for a standard syntax and + customised variants.</p> + + + <h3><a name="ap_listen" id="ap_listen">ap_listen (changed; backwards-compatible)</a></h3> + + <p>Introduces a new API to enable httpd child processes to serve + different purposes.</p> + + + <h3><a name="ap_mpm" id="ap_mpm">ap_mpm (changed)</a></h3> + + <p><code>ap_mpm_run</code> is replaced by a new <code>mpm</code> hook. + Also <code>ap_graceful_stop_signalled</code> is lost, and + <code>ap_mpm_register_timed_callback</code> is new.</p> + + + <h3><a name="ap_regex" id="ap_regex">ap_regex (changed)</a></h3> + + <p>In addition to the existing regexp wrapper, a new higher-level API + <code>ap_rxplus</code> is now provided. This provides the capability to + compile Perl-style expressions like <code>s/regexp/replacement/flags</code> + and to execute them against arbitrary strings. Support for regexp + backreferences is also added.</p> + + + <h3><a name="ap_slotmem" id="ap_slotmem">ap_slotmem (NEW!)</a></h3> + + <p>Introduces an API for modules to allocate and manage memory slots, + most commonly for shared memory.</p> + + + <h3><a name="ap_socache" id="ap_socache">ap_socache (NEW!)</a></h3> + + <p>API to manage a shared object cache.</p> + + + <h3><a name="heartbeat" id="heartbeat">heartbeat (NEW!)</a></h3> + + <p>common structures for heartbeat modules</p> + + + <h3><a name="ap_parse_htaccess" id="ap_parse_htaccess">ap_parse_htaccess (changed)</a></h3> + + <p>The function signature for <code>ap_parse_htaccess</code> has been + changed. A <code>apr_table_t</code> of individual directives allowed + for override must now be passed (override remains).</p> + + + <h3><a name="http_config" id="http_config">http_config (changed)</a></h3> + + <ul> + <li>Introduces per-module, per-directory loglevels, including macro wrappers.</li> + <li>New <code>AP_DECLARE_MODULE</code> macro to declare all modules.</li> + <li>New <code>APLOG_USE_MODULE</code> macro necessary for per-module loglevels in + multi-file modules.</li> + <li>New API to retain data across module unload/load</li> + <li>New <code>check_config</code> hook</li> + <li>New <code>ap_process_fnmatch_configs()</code> function to process wildcards</li> + <li>Change <code>ap_configfile_t</code>, <code>ap_cfg_getline()</code>, + <code>ap_cfg_getc()</code> to return error codes, and add + <code>ap_pcfg_strerror()</code> for retrieving an error description.</li> + <li>Any config directive permitted in ACCESS_CONF context must now + correctly handle being called from an .htaccess file via the new + <code class="directive"><a href="../mod/core.html#allowoverridelist">AllowOverrideList</a></code> directive. + ap_check_cmd_context() accepts a new flag NOT_IN_HTACCESS to detect + this case.</li> + </ul> + + + <h3><a name="http_core" id="http_core">http_core (changed)</a></h3> + + <ul> + <li>REMOVED <code>ap_default_type</code>, <code>ap_requires</code>, all + 2.2 authnz API</li> + <li>Introduces Optional Functions for logio and authnz</li> + <li>New function <code>ap_get_server_name_for_url</code> to support IPv6 + literals.</li> + <li>New function <code>ap_register_errorlog_handler</code> to register error log + format string handlers.</li> + <li>Arguments of <code>error_log</code> hook have changed. Declaration has moved to + <code>http_core.h</code>.</li> + <li>New function <code>ap_state_query</code> to determine if the server is in the + initial configuration preflight phase or not. This is both easier to + use and more correct than the old method of creating a pool userdata + entry in the process pool.</li> + <li>New function <code>ap_get_conn_socket</code> to get the socket descriptor for a + connection. This should be used instead of accessing the core + connection config directly.</li> + </ul> + + + <h3><a name="httpd" id="httpd">httpd (changed)</a></h3> + + <ul> + <li>Introduce per-directory, per-module loglevel</li> + <li>New loglevels <code>APLOG_TRACEn</code></li> + <li>Introduce errorlog ids for requests and connections</li> + <li>Support for mod_request kept_body</li> + <li>Support buffering filter data for async requests</li> + <li>New <code>CONN_STATE</code> values</li> + <li>Function changes: <code>ap_escape_html</code> updated; + <code>ap_unescape_all</code>, <code>ap_escape_path_segment_buffer</code></li> + <li>Modules that load other modules later than the <code>EXEC_ON_READ</code> config + reading stage need to call <code>ap_reserve_module_slots()</code> or + <code>ap_reserve_module_slots_directive()</code> in their + <code>pre_config hook</code>.</li> + <li>The useragent IP address per request can now be tracked + independently of the client IP address of the connection, for + support of deployments with load balancers.</li> + </ul> + + + <h3><a name="http_log" id="http_log">http_log (changed)</a></h3> + + <ul> + <li>Introduce per-directory, per-module loglevel</li> + <li>New loglevels <code>APLOG_TRACEn</code></li> + <li><code>ap_log_*error</code> become macro wrappers (backwards-compatible if + <code>APLOG_MARK</code> macro is used, except that is no longer possible to + use <code>#ifdef</code> inside the argument list)</li> + <li>piped logging revamped</li> + <li><code>module_index</code> added to error_log hook</li> + <li>new function: <code>ap_log_command_line</code></li> + </ul> + + + <h3><a name="http_request" id="http_request">http_request (changed)</a></h3> + + <ul> + <li>New auth_internal API and auth_provider API</li> + <li>New <code>EOR</code> bucket type</li> + <li>New function <code>ap_process_async_request</code></li> + <li>New flags <code>AP_AUTH_INTERNAL_PER_CONF</code> and + <code>AP_AUTH_INTERNAL_PER_URI</code></li> + <li>New <code>access_checker_ex</code> hook to apply additional access control + and/or bypass authentication.</li> + <li>New functions <code>ap_hook_check_access_ex</code>, + <code>ap_hook_check_access</code>, <code>ap_hook_check_authn</code>, + <code>ap_hook_check_authz</code> which accept + <code>AP_AUTH_INTERNAL_PER_*</code> flags</li> + <li>DEPRECATED direct use of <code>ap_hook_access_checker</code>, + <code>access_checker_ex</code>, <code>ap_hook_check_user_id</code>, + <code>ap_hook_auth_checker</code></li> + </ul> + <p>When possible, registering all access control hooks (including + authentication and authorization hooks) using <code>AP_AUTH_INTERNAL_PER_CONF</code> + is recommended. If all modules' access control hooks are registered + with this flag, then whenever the server handles an internal + sub-request that matches the same set of access control configuration + directives as the initial request (which is the common case), it can + avoid invoking the access control hooks another time.</p> + <p>If your module requires the old behavior and must perform access + control checks on every sub-request with a different URI from the + initial request, even if that URI matches the same set of access + control configuration directives, then use + <code>AP_AUTH_INTERNAL_PER_URI</code>.</p> + + + <h3><a name="mod_auth" id="mod_auth">mod_auth (NEW!)</a></h3> + + <p>Introduces the new provider framework for authn and authz</p> + + + <h3><a name="mod_cache" id="mod_cache">mod_cache (changed)</a></h3> + + <p>Introduces a <code>commit_entity()</code> function to the cache provider + interface, allowing atomic writes to cache. Add a <code>cache_status()</code> + hook to report the cache decision. All private structures and functions were + removed.</p> + + + <h3><a name="mod_core" id="mod_core">mod_core (NEW!)</a></h3> + + <p>This introduces low-level APIs to send arbitrary headers, + and exposes functions to handle HTTP OPTIONS and TRACE.</p> + + + <h3><a name="mod_cache_disk" id="mod_cache_disk">mod_cache_disk (changed)</a></h3> + + <p>Changes the disk format of the disk cache to support atomic cache + updates without locking. The device/inode pair of the body file is + embedded in the header file, allowing confirmation that the header + and body belong to one another.</p> + + + <h3><a name="mod_disk_cache" id="mod_disk_cache">mod_disk_cache (renamed)</a></h3> + + <p>The mod_disk_cache module has been renamed to mod_cache_disk in + order to be consistent with the naming of other modules within the + server.</p> + + + <h3><a name="mod_request" id="mod_request">mod_request (NEW!)</a></h3> + + <p>The API for <code class="module"><a href="../mod/mod_request.html">mod_request</a></code>, to make input data + available to multiple application/handler modules where required, + and to parse HTML form data.</p> + + + <h3><a name="mpm_common" id="mpm_common">mpm_common (changed)</a></h3> + + <ul> + <li>REMOVES: <code>accept</code>, <code>lockfile</code>, <code>lock_mech</code>, + <code>set_scoreboard</code> (locking uses the new ap_mutex API)</li> + <li>NEW API to drop privileges (delegates this platform-dependent + function to modules)</li> + <li>NEW Hooks: <code>mpm_query</code>, <code>timed_callback</code>, and + <code>get_name</code></li> + <li>CHANGED interfaces: <code>monitor</code> hook, + <code>ap_reclaim_child_processes</code>, + <code>ap_relieve_child_processes</code></li> + </ul> + + + <h3><a name="scoreboard" id="scoreboard">scoreboard (changed)</a></h3> + + <p><code>ap_get_scoreboard_worker</code> is made non-backwards-compatible + as an alternative version is introduced. Additional proxy_balancer + support. Child status stuff revamped.</p> + + + <h3><a name="util_cookies" id="util_cookies">util_cookies (NEW!)</a></h3> + + <p>Introduces a new API for managing HTTP Cookies.</p> + + + <h3><a name="util_ldap" id="util_ldap">util_ldap (changed)</a></h3> + + <p><em>no description available</em></p> + + + <h3><a name="util_mutex" id="util_mutex">util_mutex (NEW!)</a></h3> + + <p>A wrapper for APR proc and global mutexes in httpd, providing + common configuration for the underlying mechanism and location + of lock files.</p> + + + <h3><a name="util_script" id="util_script">util_script (changed)</a></h3> + + <p>NEW: <code>ap_args_to_table</code></p> + + + <h3><a name="util_time" id="util_time">util_time (changed)</a></h3> + + <p>NEW: <code>ap_recent_ctime_ex</code></p> + + +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="upgrading" id="upgrading">Specific information on upgrading modules from 2.2</a></h2> + + + <h3><a name="upgrading_logging" id="upgrading_logging">Logging</a></h3> + + <p>In order to take advantage of per-module loglevel configuration, any + source file that calls the <code>ap_log_*</code> functions should declare + which module it belongs to. If the module's module_struct is called + <code>foo_module</code>, the following code can be used to remain + backward compatible with HTTPD 2.0 and 2.2:</p> + <div class="example"><p><code> + #include <http_log.h><br /> + <br /> + #ifdef APLOG_USE_MODULE<br /> + APLOG_USE_MODULE(foo);<br /> + #endif + </code></p></div> + <p>Note: This is absolutely required for C++-language modules. It + can be skipped for C-language modules, though that breaks + module-specific log level support for files without it.</p> + <p>The number of parameters of the <code>ap_log_*</code> functions and the + definition of <code>APLOG_MARK</code> has changed. Normally, the change + is completely transparent. However, changes are required if a + module uses <code>APLOG_MARK</code> as a parameter to its own functions + or if a module calls <code>ap_log_*</code> without passing + <code>APLOG_MARK</code>. A module which uses wrappers + around <code>ap_log_*</code> typically uses both of these constructs.</p> + + <p>The easiest way to change code which passes <code>APLOG_MARK</code> to + its own functions is to define and use a different macro that expands to + the parameters required by those functions, as <code>APLOG_MARK</code> + should only be used when calling <code>ap_log_*</code> + directly. In this way, the code will remain compatible with HTTPD 2.0 + and 2.2.</p> + + <p>Code which calls <code>ap_log_*</code> without passing + <code>APLOG_MARK</code> will necessarily differ between 2.4 and earlier + releases, as 2.4 requires a new third argument, + <code>APLOG_MODULE_INDEX</code>.</p> + + <div class="example"><p><code> + /* code for httpd 2.0/2.2 */<br /> + ap_log_perror(file, line, APLOG_ERR, 0, p, "Failed to allocate dynamic lock structure");<br /> + <br /> + /* code for httpd 2.4 */<br /> + ap_log_perror(file, line, APLOG_MODULE_INDEX, APLOG_ERR, 0, p, "Failed to allocate dynamic lock structure");<br /> + <br /> + </code></p></div> + + <p><code>ap_log_*error</code> are now implemented as macros. This means + that it is no longer possible to use <code>#ifdef</code> inside the + argument list of <code>ap_log_*error</code>, as this would cause + undefined behavior according to C99.</p> + + <p>A <code>server_rec</code> pointer must be passed to + <code>ap_log_error()</code> when called after startup. This + was always appropriate, but there are even more limitations with + a <code>NULL</code> <code>server_rec</code> in 2.4 than in + previous releases. Beginning with 2.3.12, the global variable + <code>ap_server_conf</code> can always be used as + the <code>server_rec</code> parameter, as it will be + <code>NULL</code> only when it is valid to pass <code>NULL</code> + to <code>ap_log_error()</code>. <code>ap_server_conf</code> + should be used only when a more appropriate <code>server_rec</code> + is not available.</p> + + <p>Consider the following changes to take advantage of the new + <code>APLOG_TRACE1..8</code> log levels:</p> + <ul> + <li>Check current use of <code>APLOG_DEBUG</code> and + consider if one of the <code>APLOG_TRACEn</code> levels is + more appropriate.</li> + <li>If your module currently has a mechanism for configuring + the amount of debug logging which is performed, consider + eliminating that mechanism and relying on the use of + different <code>APLOG_TRACEn</code> levels. If expensive + trace processing needs to be bypassed depending on the + configured log level, use the <code>APLOGtrace<em>n</em></code> + and <code>APLOGrtrace<em>n</em></code> macros to first check + if tracing is enabled.</li> + </ul> + + <p>Modules sometimes add process id and/or thread id to their log + messages. These ids are now logged by default, so it may not + be necessary for the module to log them explicitly. (Users may + remove them from the error log format, but they can be + instructed to add it back if necessary for problem diagnosis.)</p> + + + <h3><a name="upgrading_byfunction" id="upgrading_byfunction">If your module uses these existing APIs...</a></h3> + + + <dl> + <dt><code>ap_default_type()</code></dt> + <dd>This is no longer available; Content-Type must be configured + explicitly or added by the application.</dd> + + <dt><code>ap_get_server_name()</code></dt> + <dd>If the returned server name is used in a URL, + use <code>ap_get_server_name_for_url()</code> instead. This new + function handles the odd case where the server name is an IPv6 + literal address.</dd> + + <dt><code>ap_get_server_version()</code></dt> + <dd>For logging purposes, where detailed information is + appropriate, use <code>ap_get_server_description()</code>. + When generating output, where the amount of information + should be configurable by ServerTokens, use + <code>ap_get_server_banner()</code>.</dd> + + <dt><code>ap_graceful_stop_signalled()</code></dt> + <dd>Replace with a call + to <code>ap_mpm_query(AP_MPMQ_MPM_STATE)</code> and checking for + state <code>AP_MPMQ_STOPPING</code>.</dd> + + <dt><code>ap_max_daemons_limit</code>, <code>ap_my_generation</code>, + and <code>ap_threads_per_child</code></dt> + <dd>Use <code>ap_mpm_query()</code> query codes + <code>AP_MPMQ_MAX_DAEMON_USED</code>, <code>AP_MPMQ_GENERATION</code>, + and <code>AP_MPMQ_MAX_THREADS</code>, respectively.</dd> + + <dt><code>ap_mpm_query()</code></dt> + <dd>Ensure that it is not used until after the register-hooks + hook has completed. Otherwise, an MPM built as a DSO + would not have had a chance to enable support for this + function.</dd> + + <dt><code>ap_requires()</code></dt> + <dd>The core server now provides better infrastructure for handling + <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> configuration. + Register an auth provider function for each supported entity using + <code>ap_register_auth_provider()</code>. The function will be + called as necessary during <code class="directive">Require</code> + processing. (Consult bundled modules for detailed examples.)</dd> + + <dt><code>ap_server_conf->process->pool</code> + userdata</dt> + <dd> + Optional: + <ul> + <li>If your module uses this to determine which pass of the + startup hooks is being run, + use <code>ap_state_query(AP_SQ_MAIN_STATE)</code>.</li> + <li>If your module uses this to maintain data across the + unloading and reloading of your module, use + <code>ap_retained_data_create()</code> and + <code>ap_retained_data_get()</code>.</li> + </ul> + </dd> + + <dt><code>apr_global_mutex_create()</code>, + <code>apr_proc_mutex_create()</code></dt> + <dd>Optional: See <code>ap_mutex_register()</code>, + <code>ap_global_mutex_create()</code>, and + <code>ap_proc_mutex_create()</code>; these allow your + mutexes to be configurable with + the <code class="directive"><a href="../mod/core.html#mutex">Mutex</a></code> directive; + you can also remove any configuration mechanisms in your + module for such mutexes + </dd> + + <dt><code>CORE_PRIVATE</code></dt> + <dd>This is now unnecessary and ignored.</dd> + + <dt><code>dav_new_error()</code> + and <code>dav_new_error_tag()</code></dt> + <dd>Previously, these assumed that <code>errno</code> contained + information describing the failure. Now, + an <code>apr_status_t</code> parameter must be provided. Pass + 0/APR_SUCCESS if there is no such error information, or a valid + <code>apr_status_t</code> value otherwise.</dd> + + <dt><code>mpm_default.h</code>, <code>DEFAULT_LOCKFILE</code>, + <code>DEFAULT_THREAD_LIMIT</code>, <code>DEFAULT_PIDLOG</code>, + etc.</dt> + <dd>The header file and most of the default configuration + values set in it are no longer visible to modules. (Most can + still be overridden at build time.) <code>DEFAULT_PIDLOG</code> + and <code>DEFAULT_REL_RUNTIMEDIR</code> are now universally + available via <code>ap_config.h</code>.</dd> + + <dt><code>unixd_config</code></dt> + <dd>This has been renamed to ap_unixd_config.</dd> + + <dt><code>unixd_setup_child()</code></dt> + <dd>This has been renamed to ap_unixd_setup_child(), but most callers + should call the added ap_run_drop_privileges() hook.</dd> + + <dt><code>conn_rec->remote_ip</code> and + <code>conn_rec->remote_addr</code></dt> + <dd>These fields have been renamed in order to distinguish between + the client IP address of the connection and the useragent IP address + of the request (potentially overridden by a load balancer or proxy). + References to either of these fields must be updated with one of the + following options, as appropriate for the module: + <ul> + <li>When you require the IP address of the user agent, which + might be connected directly to the server, or might optionally be + separated from the server by a transparent load balancer or + proxy, use <code>request_rec->useragent_ip</code> and + <code>request_rec->useragent_addr</code>.</li> + <li>When you require the IP address of the client that is + connected directly to the server, which might be the useragent or + might be the load balancer or proxy itself, use + <code>conn_rec->client_ip</code> and + <code>conn_rec->client_addr</code>.</li> + </ul> + </dd> + </dl> + + + <h3><a name="upgrading_byfeature" id="upgrading_byfeature">If your module interfaces with this feature...</a></h3> + + <dl> + <dt>suEXEC</dt> + <dd>Optional: If your module logs an error + when <code>ap_unixd_config.suexec_enabled</code> is 0, + also log the value of the new + field <code>suexec_disabled_reason</code>, which contains an + explanation of why it is not available.</dd> + + <dt>Extended status data in the scoreboard</dt> + <dd>In previous releases, <code>ExtendedStatus</code> had to be + set to <code>On</code>, which in turn required that + mod_status was loaded. In 2.4, just + set <code>ap_extended_status</code> to <code>1</code> in a + pre-config hook and the extended status data will be + available.</dd> + </dl> + + + <h3><a name="upgrading_newfeatures" id="upgrading_newfeatures">Does your module...</a></h3> + + <dl> + <dt>Parse query args</dt> + <dd>Consider if <code>ap_args_to_table()</code> would be + helpful.</dd> + + <dt>Parse form data...</dt> + <dd>Use <code>ap_parse_form_data()</code>.</dd> + + <dt>Check for request header fields <code>Content-Length</code> + and <code>Transfer-Encoding</code> to see if a body was + specified</dt> + <dd>Use <code>ap_request_has_body()</code>.</dd> + + <dt>Implement cleanups which clear pointer variables</dt> + <dd>Use <code>ap_pool_cleanup_set_null()</code>.</dd> + + <dt>Create run-time files such as shared memory files, pid files, + etc.</dt> + <dd>Use <code>ap_runtime_dir_relative()</code> so that the global + configuration for the location of such files, either by the + <code>DEFAULT_REL_RUNTIMEDIR</code> compile setting or the + <code class="directive"><a href="../mod/core.html#defaultruntimedir">DefaultRuntimeDir</a></code> directive, + will be respected. <em>Apache httpd 2.4.2 and above.</em></dd> + + </dl> + + +</div></div> +<div class="bottomlang"> +<p><span>Available Languages: </span><a href="../en/developer/new_api_2_4.html" title="English"> en </a></p> +</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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