view src/http/ngx_http_variables.c @ 9203:0de20f43db25

Fixed request termination with AIO and subrequests (ticket #2555). When a request was terminated due to an error via ngx_http_terminate_request() while an AIO operation was running in a subrequest, various issues were observed. This happened because ngx_http_request_finalizer() was only set in the subrequest where ngx_http_terminate_request() was called, but not in the subrequest where the AIO operation was running. After completion of the AIO operation normal processing of the subrequest was resumed, leading to issues. In particular, in case of the upstream module, termination of the request called upstream cleanup, which closed the upstream connection. Attempts to further work with the upstream connection after AIO operation completion resulted in segfaults in ngx_ssl_recv(), "readv() failed (9: Bad file descriptor) while reading upstream" errors, or socket leaks. In ticket #2555, issues were observed with the following configuration with cache background update (with thread writing instrumented to introduce a delay, when a client closes the connection during an update): location = /background-and-aio-write { proxy_pass ... proxy_cache one; proxy_cache_valid 200 1s; proxy_cache_background_update on; proxy_cache_use_stale updating; aio threads; aio_write on; limit_rate 1000; } Similarly, the same issue can be seen with SSI, and can be caused by errors in subrequests, such as in the following configuration (where "/proxy" uses AIO, and "/sleep" returns 444 after some delay, causing request termination): location = /ssi-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Or the same with both AIO operation and the error in non-active subrequests (which needs slightly different handling, see below): location = /ssi-non-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Similarly, issues can be observed with just static files. However, with static files potential impact is limited due to timeout safeguards in ngx_http_writer(), and the fact that c->error is set during request termination. In a simple configuration with an AIO operation in the active subrequest, such as in the following configuration, the connection is closed right after completion of the AIO operation anyway, since ngx_http_writer() tries to write to the connection and fails due to c->error set: location = /ssi-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } In the following configuration, with an AIO operation in a non-active subrequest, the connection is closed only after send_timeout expires: location = /ssi-non-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Fix is to introduce r->main->terminated flag, which is to be checked by AIO event handlers when the r->main->blocked counter is decremented. When the flag is set, handlers are expected to wake up the connection instead of the subrequest (which might be already cleaned up). Additionally, now ngx_http_request_finalizer() is always set in the active subrequest, so waking up the connection properly finalizes the request even if termination happened in a non-active subrequest.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 30 Jan 2024 03:20:05 +0300
parents b71e69247483
children 106b3832e7ef
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <nginx.h>


static ngx_http_variable_t *ngx_http_add_prefix_variable(ngx_conf_t *cf,
    ngx_str_t *name, ngx_uint_t flags);

static ngx_int_t ngx_http_variable_request(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
#if 0
static void ngx_http_variable_request_set(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
#endif
static ngx_int_t ngx_http_variable_request_get_size(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_header(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_variable_cookies(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_headers_internal(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data, u_char sep);

static ngx_int_t ngx_http_variable_unknown_header_in(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_unknown_header_out(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_unknown_trailer_out(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_line(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_cookie(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_argument(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
#if (NGX_HAVE_TCP_INFO)
static ngx_int_t ngx_http_variable_tcpinfo(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
#endif

static ngx_int_t ngx_http_variable_content_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_host(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_binary_remote_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_remote_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_remote_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_proxy_protocol_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_proxy_protocol_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_proxy_protocol_tlv(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_server_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_server_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_scheme(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_https(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static void ngx_http_variable_set_args(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_is_args(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_document_root(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_realpath_root(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_filename(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_server_name(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_method(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_remote_user(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_bytes_sent(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_body_bytes_sent(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_pipe(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_completion(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_body(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_body_file(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_time(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_id(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_status(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_variable_sent_content_type(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_content_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_location(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_last_modified(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_connection(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_keep_alive(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_sent_transfer_encoding(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static void ngx_http_variable_set_limit_rate(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_variable_connection(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_connection_requests(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_connection_time(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_variable_nginx_version(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_hostname(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_pid(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_msec(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_time_iso8601(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_time_local(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

/*
 * TODO:
 *     Apache CGI: AUTH_TYPE, PATH_INFO (null), PATH_TRANSLATED
 *                 REMOTE_HOST (null), REMOTE_IDENT (null),
 *                 SERVER_SOFTWARE
 *
 *     Apache SSI: DOCUMENT_NAME, LAST_MODIFIED, USER_NAME (file owner)
 */

/*
 * the $http_host, $http_user_agent, $http_referer, and $http_via
 * variables may be handled by generic
 * ngx_http_variable_unknown_header_in(), but for performance reasons
 * they are handled using dedicated entries
 */

static ngx_http_variable_t  ngx_http_core_variables[] = {

    { ngx_string("http_host"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.host), 0, 0 },

    { ngx_string("http_user_agent"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.user_agent), 0, 0 },

    { ngx_string("http_referer"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.referer), 0, 0 },

#if (NGX_HTTP_GZIP)
    { ngx_string("http_via"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.via), 0, 0 },
#endif

#if (NGX_HTTP_X_FORWARDED_FOR)
    { ngx_string("http_x_forwarded_for"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.x_forwarded_for), 0, 0 },
#endif

    { ngx_string("http_cookie"), NULL, ngx_http_variable_cookies,
      offsetof(ngx_http_request_t, headers_in.cookie), 0, 0 },

    { ngx_string("content_length"), NULL, ngx_http_variable_content_length,
      0, 0, 0 },

    { ngx_string("content_type"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_in.content_type), 0, 0 },

    { ngx_string("host"), NULL, ngx_http_variable_host, 0, 0, 0 },

    { ngx_string("binary_remote_addr"), NULL,
      ngx_http_variable_binary_remote_addr, 0, 0, 0 },

    { ngx_string("remote_addr"), NULL, ngx_http_variable_remote_addr, 0, 0, 0 },

    { ngx_string("remote_port"), NULL, ngx_http_variable_remote_port, 0, 0, 0 },

    { ngx_string("proxy_protocol_addr"), NULL,
      ngx_http_variable_proxy_protocol_addr,
      offsetof(ngx_proxy_protocol_t, src_addr), 0, 0 },

    { ngx_string("proxy_protocol_port"), NULL,
      ngx_http_variable_proxy_protocol_port,
      offsetof(ngx_proxy_protocol_t, src_port), 0, 0 },

    { ngx_string("proxy_protocol_server_addr"), NULL,
      ngx_http_variable_proxy_protocol_addr,
      offsetof(ngx_proxy_protocol_t, dst_addr), 0, 0 },

    { ngx_string("proxy_protocol_server_port"), NULL,
      ngx_http_variable_proxy_protocol_port,
      offsetof(ngx_proxy_protocol_t, dst_port), 0, 0 },

    { ngx_string("proxy_protocol_tlv_"), NULL,
      ngx_http_variable_proxy_protocol_tlv,
      0, NGX_HTTP_VAR_PREFIX, 0 },

    { ngx_string("server_addr"), NULL, ngx_http_variable_server_addr, 0, 0, 0 },

    { ngx_string("server_port"), NULL, ngx_http_variable_server_port, 0, 0, 0 },

    { ngx_string("server_protocol"), NULL, ngx_http_variable_request,
      offsetof(ngx_http_request_t, http_protocol), 0, 0 },

    { ngx_string("scheme"), NULL, ngx_http_variable_scheme, 0, 0, 0 },

    { ngx_string("https"), NULL, ngx_http_variable_https, 0, 0, 0 },

    { ngx_string("request_uri"), NULL, ngx_http_variable_request,
      offsetof(ngx_http_request_t, unparsed_uri), 0, 0 },

    { ngx_string("uri"), NULL, ngx_http_variable_request,
      offsetof(ngx_http_request_t, uri),
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("document_uri"), NULL, ngx_http_variable_request,
      offsetof(ngx_http_request_t, uri),
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("request"), NULL, ngx_http_variable_request_line, 0, 0, 0 },

    { ngx_string("document_root"), NULL,
      ngx_http_variable_document_root, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("realpath_root"), NULL,
      ngx_http_variable_realpath_root, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("query_string"), NULL, ngx_http_variable_request,
      offsetof(ngx_http_request_t, args),
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("args"),
      ngx_http_variable_set_args,
      ngx_http_variable_request,
      offsetof(ngx_http_request_t, args),
      NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("is_args"), NULL, ngx_http_variable_is_args,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("request_filename"), NULL,
      ngx_http_variable_request_filename, 0,
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("server_name"), NULL, ngx_http_variable_server_name, 0, 0, 0 },

    { ngx_string("request_method"), NULL,
      ngx_http_variable_request_method, 0,
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("remote_user"), NULL, ngx_http_variable_remote_user, 0, 0, 0 },

    { ngx_string("bytes_sent"), NULL, ngx_http_variable_bytes_sent,
      0, 0, 0 },

    { ngx_string("body_bytes_sent"), NULL, ngx_http_variable_body_bytes_sent,
      0, 0, 0 },

    { ngx_string("pipe"), NULL, ngx_http_variable_pipe,
      0, 0, 0 },

    { ngx_string("request_completion"), NULL,
      ngx_http_variable_request_completion,
      0, 0, 0 },

    { ngx_string("request_body"), NULL,
      ngx_http_variable_request_body,
      0, 0, 0 },

    { ngx_string("request_body_file"), NULL,
      ngx_http_variable_request_body_file,
      0, 0, 0 },

    { ngx_string("request_length"), NULL, ngx_http_variable_request_length,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("request_time"), NULL, ngx_http_variable_request_time,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("request_id"), NULL,
      ngx_http_variable_request_id,
      0, 0, 0 },

    { ngx_string("status"), NULL,
      ngx_http_variable_status, 0,
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("sent_http_content_type"), NULL,
      ngx_http_variable_sent_content_type, 0, 0, 0 },

    { ngx_string("sent_http_content_length"), NULL,
      ngx_http_variable_sent_content_length, 0, 0, 0 },

    { ngx_string("sent_http_location"), NULL,
      ngx_http_variable_sent_location, 0, 0, 0 },

    { ngx_string("sent_http_last_modified"), NULL,
      ngx_http_variable_sent_last_modified, 0, 0, 0 },

    { ngx_string("sent_http_connection"), NULL,
      ngx_http_variable_sent_connection, 0, 0, 0 },

    { ngx_string("sent_http_keep_alive"), NULL,
      ngx_http_variable_sent_keep_alive, 0, 0, 0 },

    { ngx_string("sent_http_transfer_encoding"), NULL,
      ngx_http_variable_sent_transfer_encoding, 0, 0, 0 },

    { ngx_string("sent_http_cache_control"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_out.cache_control), 0, 0 },

    { ngx_string("sent_http_link"), NULL, ngx_http_variable_header,
      offsetof(ngx_http_request_t, headers_out.link), 0, 0 },

    { ngx_string("limit_rate"), ngx_http_variable_set_limit_rate,
      ngx_http_variable_request_get_size,
      offsetof(ngx_http_request_t, limit_rate),
      NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("connection"), NULL,
      ngx_http_variable_connection, 0, 0, 0 },

    { ngx_string("connection_requests"), NULL,
      ngx_http_variable_connection_requests, 0, 0, 0 },

    { ngx_string("connection_time"), NULL, ngx_http_variable_connection_time,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("nginx_version"), NULL, ngx_http_variable_nginx_version,
      0, 0, 0 },

    { ngx_string("hostname"), NULL, ngx_http_variable_hostname,
      0, 0, 0 },

    { ngx_string("pid"), NULL, ngx_http_variable_pid,
      0, 0, 0 },

    { ngx_string("msec"), NULL, ngx_http_variable_msec,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("time_iso8601"), NULL, ngx_http_variable_time_iso8601,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("time_local"), NULL, ngx_http_variable_time_local,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

#if (NGX_HAVE_TCP_INFO)
    { ngx_string("tcpinfo_rtt"), NULL, ngx_http_variable_tcpinfo,
      0, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("tcpinfo_rttvar"), NULL, ngx_http_variable_tcpinfo,
      1, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("tcpinfo_snd_cwnd"), NULL, ngx_http_variable_tcpinfo,
      2, NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("tcpinfo_rcv_space"), NULL, ngx_http_variable_tcpinfo,
      3, NGX_HTTP_VAR_NOCACHEABLE, 0 },
#endif

    { ngx_string("http_"), NULL, ngx_http_variable_unknown_header_in,
      0, NGX_HTTP_VAR_PREFIX, 0 },

    { ngx_string("sent_http_"), NULL, ngx_http_variable_unknown_header_out,
      0, NGX_HTTP_VAR_PREFIX, 0 },

    { ngx_string("sent_trailer_"), NULL, ngx_http_variable_unknown_trailer_out,
      0, NGX_HTTP_VAR_PREFIX, 0 },

    { ngx_string("cookie_"), NULL, ngx_http_variable_cookie,
      0, NGX_HTTP_VAR_PREFIX, 0 },

    { ngx_string("arg_"), NULL, ngx_http_variable_argument,
      0, NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_PREFIX, 0 },

      ngx_http_null_variable
};


ngx_http_variable_value_t  ngx_http_variable_null_value =
    ngx_http_variable("");
ngx_http_variable_value_t  ngx_http_variable_true_value =
    ngx_http_variable("1");


static ngx_uint_t  ngx_http_variable_depth = 100;


ngx_http_variable_t *
ngx_http_add_variable(ngx_conf_t *cf, ngx_str_t *name, ngx_uint_t flags)
{
    ngx_int_t                   rc;
    ngx_uint_t                  i;
    ngx_hash_key_t             *key;
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    if (name->len == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"$\"");
        return NULL;
    }

    if (flags & NGX_HTTP_VAR_PREFIX) {
        return ngx_http_add_prefix_variable(cf, name, flags);
    }

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    key = cmcf->variables_keys->keys.elts;
    for (i = 0; i < cmcf->variables_keys->keys.nelts; i++) {
        if (name->len != key[i].key.len
            || ngx_strncasecmp(name->data, key[i].key.data, name->len) != 0)
        {
            continue;
        }

        v = key[i].value;

        if (!(v->flags & NGX_HTTP_VAR_CHANGEABLE)) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the duplicate \"%V\" variable", name);
            return NULL;
        }

        if (!(flags & NGX_HTTP_VAR_WEAK)) {
            v->flags &= ~NGX_HTTP_VAR_WEAK;
        }

        return v;
    }

    v = ngx_palloc(cf->pool, sizeof(ngx_http_variable_t));
    if (v == NULL) {
        return NULL;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NULL;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = flags;
    v->index = 0;

    rc = ngx_hash_add_key(cmcf->variables_keys, &v->name, v, 0);

    if (rc == NGX_ERROR) {
        return NULL;
    }

    if (rc == NGX_BUSY) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "conflicting variable name \"%V\"", name);
        return NULL;
    }

    return v;
}


static ngx_http_variable_t *
ngx_http_add_prefix_variable(ngx_conf_t *cf, ngx_str_t *name, ngx_uint_t flags)
{
    ngx_uint_t                  i;
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    v = cmcf->prefix_variables.elts;
    for (i = 0; i < cmcf->prefix_variables.nelts; i++) {
        if (name->len != v[i].name.len
            || ngx_strncasecmp(name->data, v[i].name.data, name->len) != 0)
        {
            continue;
        }

        v = &v[i];

        if (!(v->flags & NGX_HTTP_VAR_CHANGEABLE)) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the duplicate \"%V\" variable", name);
            return NULL;
        }

        if (!(flags & NGX_HTTP_VAR_WEAK)) {
            v->flags &= ~NGX_HTTP_VAR_WEAK;
        }

        return v;
    }

    v = ngx_array_push(&cmcf->prefix_variables);
    if (v == NULL) {
        return NULL;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NULL;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = flags;
    v->index = 0;

    return v;
}


ngx_int_t
ngx_http_get_variable_index(ngx_conf_t *cf, ngx_str_t *name)
{
    ngx_uint_t                  i;
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    if (name->len == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"$\"");
        return NGX_ERROR;
    }

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    v = cmcf->variables.elts;

    if (v == NULL) {
        if (ngx_array_init(&cmcf->variables, cf->pool, 4,
                           sizeof(ngx_http_variable_t))
            != NGX_OK)
        {
            return NGX_ERROR;
        }

    } else {
        for (i = 0; i < cmcf->variables.nelts; i++) {
            if (name->len != v[i].name.len
                || ngx_strncasecmp(name->data, v[i].name.data, name->len) != 0)
            {
                continue;
            }

            return i;
        }
    }

    v = ngx_array_push(&cmcf->variables);
    if (v == NULL) {
        return NGX_ERROR;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NGX_ERROR;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = 0;
    v->index = cmcf->variables.nelts - 1;

    return v->index;
}


ngx_http_variable_value_t *
ngx_http_get_indexed_variable(ngx_http_request_t *r, ngx_uint_t index)
{
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    if (cmcf->variables.nelts <= index) {
        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
                      "unknown variable index: %ui", index);
        return NULL;
    }

    if (r->variables[index].not_found || r->variables[index].valid) {
        return &r->variables[index];
    }

    v = cmcf->variables.elts;

    if (ngx_http_variable_depth == 0) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "cycle while evaluating variable \"%V\"",
                      &v[index].name);
        return NULL;
    }

    ngx_http_variable_depth--;

    if (v[index].get_handler(r, &r->variables[index], v[index].data)
        == NGX_OK)
    {
        ngx_http_variable_depth++;

        if (v[index].flags & NGX_HTTP_VAR_NOCACHEABLE) {
            r->variables[index].no_cacheable = 1;
        }

        return &r->variables[index];
    }

    ngx_http_variable_depth++;

    r->variables[index].valid = 0;
    r->variables[index].not_found = 1;

    return NULL;
}


ngx_http_variable_value_t *
ngx_http_get_flushed_variable(ngx_http_request_t *r, ngx_uint_t index)
{
    ngx_http_variable_value_t  *v;

    v = &r->variables[index];

    if (v->valid || v->not_found) {
        if (!v->no_cacheable) {
            return v;
        }

        v->valid = 0;
        v->not_found = 0;
    }

    return ngx_http_get_indexed_variable(r, index);
}


ngx_http_variable_value_t *
ngx_http_get_variable(ngx_http_request_t *r, ngx_str_t *name, ngx_uint_t key)
{
    size_t                      len;
    ngx_uint_t                  i, n;
    ngx_http_variable_t        *v;
    ngx_http_variable_value_t  *vv;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    v = ngx_hash_find(&cmcf->variables_hash, key, name->data, name->len);

    if (v) {
        if (v->flags & NGX_HTTP_VAR_INDEXED) {
            return ngx_http_get_flushed_variable(r, v->index);
        }

        if (ngx_http_variable_depth == 0) {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "cycle while evaluating variable \"%V\"", name);
            return NULL;
        }

        ngx_http_variable_depth--;

        vv = ngx_palloc(r->pool, sizeof(ngx_http_variable_value_t));

        if (vv && v->get_handler(r, vv, v->data) == NGX_OK) {
            ngx_http_variable_depth++;
            return vv;
        }

        ngx_http_variable_depth++;
        return NULL;
    }

    vv = ngx_palloc(r->pool, sizeof(ngx_http_variable_value_t));
    if (vv == NULL) {
        return NULL;
    }

    len = 0;

    v = cmcf->prefix_variables.elts;
    n = cmcf->prefix_variables.nelts;

    for (i = 0; i < cmcf->prefix_variables.nelts; i++) {
        if (name->len >= v[i].name.len && name->len > len
            && ngx_strncmp(name->data, v[i].name.data, v[i].name.len) == 0)
        {
            len = v[i].name.len;
            n = i;
        }
    }

    if (n != cmcf->prefix_variables.nelts) {
        if (v[n].get_handler(r, vv, (uintptr_t) name) == NGX_OK) {
            return vv;
        }

        return NULL;
    }

    vv->not_found = 1;

    return vv;
}


static ngx_int_t
ngx_http_variable_request(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_str_t  *s;

    s = (ngx_str_t *) ((char *) r + data);

    if (s->data) {
        v->len = s->len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = s->data;

    } else {
        v->not_found = 1;
    }

    return NGX_OK;
}


#if 0

static void
ngx_http_variable_request_set(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t  *s;

    s = (ngx_str_t *) ((char *) r + data);

    s->len = v->len;
    s->data = v->data;
}

#endif


static ngx_int_t
ngx_http_variable_request_get_size(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    size_t  *sp;

    sp = (size_t *) ((char *) r + data);

    v->data = ngx_pnalloc(r->pool, NGX_SIZE_T_LEN);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(v->data, "%uz", *sp) - v->data;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_header(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    return ngx_http_variable_headers_internal(r, v, data, ',');
}


static ngx_int_t
ngx_http_variable_cookies(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    return ngx_http_variable_headers_internal(r, v, data, ';');
}


static ngx_int_t
ngx_http_variable_headers_internal(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data, u_char sep)
{
    size_t            len;
    u_char           *p, *end;
    ngx_table_elt_t  *h, *th;

    h = *(ngx_table_elt_t **) ((char *) r + data);

    len = 0;

    for (th = h; th; th = th->next) {

        if (th->hash == 0) {
            continue;
        }

        len += th->value.len + 2;
    }

    if (len == 0) {
        v->not_found = 1;
        return NGX_OK;
    }

    len -= 2;

    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    if (h->next == NULL) {
        v->len = h->value.len;
        v->data = h->value.data;

        return NGX_OK;
    }

    p = ngx_pnalloc(r->pool, len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = len;
    v->data = p;

    end = p + len;

    for (th = h; th; th = th->next) {

        if (th->hash == 0) {
            continue;
        }

        p = ngx_copy(p, th->value.data, th->value.len);

        if (p == end) {
            break;
        }

        *p++ = sep; *p++ = ' ';
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_unknown_header_in(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    return ngx_http_variable_unknown_header(r, v, (ngx_str_t *) data,
                                            &r->headers_in.headers.part,
                                            sizeof("http_") - 1);
}


static ngx_int_t
ngx_http_variable_unknown_header_out(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    return ngx_http_variable_unknown_header(r, v, (ngx_str_t *) data,
                                            &r->headers_out.headers.part,
                                            sizeof("sent_http_") - 1);
}


static ngx_int_t
ngx_http_variable_unknown_trailer_out(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    return ngx_http_variable_unknown_header(r, v, (ngx_str_t *) data,
                                            &r->headers_out.trailers.part,
                                            sizeof("sent_trailer_") - 1);
}


ngx_int_t
ngx_http_variable_unknown_header(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, ngx_str_t *var,
    ngx_list_part_t *part, size_t prefix)
{
    u_char           *p, ch;
    size_t            len;
    ngx_uint_t        i, n;
    ngx_table_elt_t  *header, *h, **ph;

    ph = &h;
#if (NGX_SUPPRESS_WARN)
    len = 0;
#endif

    header = part->elts;

    for (i = 0; /* void */ ; i++) {

        if (i >= part->nelts) {
            if (part->next == NULL) {
                break;
            }

            part = part->next;
            header = part->elts;
            i = 0;
        }

        if (header[i].hash == 0) {
            continue;
        }

        if (header[i].key.len != var->len - prefix) {
            continue;
        }

        for (n = 0; n < var->len - prefix; n++) {
            ch = header[i].key.data[n];

            if (ch >= 'A' && ch <= 'Z') {
                ch |= 0x20;

            } else if (ch == '-') {
                ch = '_';
            }

            if (var->data[n + prefix] != ch) {
                break;
            }
        }

        if (n != var->len - prefix) {
            continue;
        }

        len += header[i].value.len + 2;

        *ph = &header[i];
        ph = &header[i].next;
    }

    *ph = NULL;

    if (h == NULL) {
        v->not_found = 1;
        return NGX_OK;
    }

    len -= 2;

    if (h->next == NULL) {

        v->len = h->value.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = h->value.data;

        return NGX_OK;
    }

    p = ngx_pnalloc(r->pool, len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    for ( ;; ) {

        p = ngx_copy(p, h->value.data, h->value.len);

        if (h->next == NULL) {
            break;
        }

        *p++ = ','; *p++ = ' ';

        h = h->next;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_line(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p, *s;

    s = r->request_line.data;

    if (s == NULL) {
        s = r->request_start;

        if (s == NULL) {
            v->not_found = 1;
            return NGX_OK;
        }

        for (p = s; p < r->header_in->last; p++) {
            if (*p == CR || *p == LF) {
                break;
            }
        }

        r->request_line.len = p - s;
        r->request_line.data = s;
    }

    v->len = r->request_line.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = s;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_cookie(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_str_t *name = (ngx_str_t *) data;

    ngx_str_t  cookie, s;

    s.len = name->len - (sizeof("cookie_") - 1);
    s.data = name->data + sizeof("cookie_") - 1;

    if (ngx_http_parse_multi_header_lines(r, r->headers_in.cookie, &s, &cookie)
        == NULL)
    {
        v->not_found = 1;
        return NGX_OK;
    }

    v->len = cookie.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = cookie.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_argument(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_str_t *name = (ngx_str_t *) data;

    u_char     *arg;
    size_t      len;
    ngx_str_t   value;

    len = name->len - (sizeof("arg_") - 1);
    arg = name->data + sizeof("arg_") - 1;

    if (len == 0 || ngx_http_arg(r, arg, len, &value) != NGX_OK) {
        v->not_found = 1;
        return NGX_OK;
    }

    v->data = value.data;
    v->len = value.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


#if (NGX_HAVE_TCP_INFO)

static ngx_int_t
ngx_http_variable_tcpinfo(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    struct tcp_info  ti;
    socklen_t        len;
    uint32_t         value;

    len = sizeof(struct tcp_info);
    if (getsockopt(r->connection->fd, IPPROTO_TCP, TCP_INFO, &ti, &len) == -1) {
        v->not_found = 1;
        return NGX_OK;
    }

    v->data = ngx_pnalloc(r->pool, NGX_INT32_LEN);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    switch (data) {
    case 0:
        value = ti.tcpi_rtt;
        break;

    case 1:
        value = ti.tcpi_rttvar;
        break;

    case 2:
        value = ti.tcpi_snd_cwnd;
        break;

    case 3:
        value = ti.tcpi_rcv_space;
        break;

    /* suppress warning */
    default:
        value = 0;
        break;
    }

    v->len = ngx_sprintf(v->data, "%uD", value) - v->data;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}

#endif


static ngx_int_t
ngx_http_variable_content_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    if (r->headers_in.content_length) {
        v->len = r->headers_in.content_length->value.len;
        v->data = r->headers_in.content_length->value.data;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;

    } else if (r->reading_body) {
        v->not_found = 1;
        v->no_cacheable = 1;

    } else if (r->headers_in.content_length_n >= 0) {
        p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN);
        if (p == NULL) {
            return NGX_ERROR;
        }

        v->len = ngx_sprintf(p, "%O", r->headers_in.content_length_n) - p;
        v->data = p;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;

    } else if (r->headers_in.chunked) {
        v->not_found = 1;
        v->no_cacheable = 1;

    } else {
        v->not_found = 1;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_host(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_http_core_srv_conf_t  *cscf;

    if (r->headers_in.server.len) {
        v->len = r->headers_in.server.len;
        v->data = r->headers_in.server.data;

    } else {
        cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

        v->len = cscf->server_name.len;
        v->data = cscf->server_name.data;
    }

    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_binary_remote_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    struct sockaddr_in   *sin;
#if (NGX_HAVE_INET6)
    struct sockaddr_in6  *sin6;
#endif

    switch (r->connection->sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
    case AF_INET6:
        sin6 = (struct sockaddr_in6 *) r->connection->sockaddr;

        v->len = sizeof(struct in6_addr);
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = sin6->sin6_addr.s6_addr;

        break;
#endif

#if (NGX_HAVE_UNIX_DOMAIN)
    case AF_UNIX:

        v->len = r->connection->addr_text.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->connection->addr_text.data;

        break;
#endif

    default: /* AF_INET */
        sin = (struct sockaddr_in *) r->connection->sockaddr;

        v->len = sizeof(in_addr_t);
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) &sin->sin_addr;

        break;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_remote_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    v->len = r->connection->addr_text.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = r->connection->addr_text.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_remote_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t  port;

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->data = ngx_pnalloc(r->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = ngx_inet_get_port(r->connection->sockaddr);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_proxy_protocol_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t             *addr;
    ngx_proxy_protocol_t  *pp;

    pp = r->connection->proxy_protocol;
    if (pp == NULL) {
        v->not_found = 1;
        return NGX_OK;
    }

    addr = (ngx_str_t *) ((char *) pp + data);

    v->len = addr->len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = addr->data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_proxy_protocol_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t             port;
    ngx_proxy_protocol_t  *pp;

    pp = r->connection->proxy_protocol;
    if (pp == NULL) {
        v->not_found = 1;
        return NGX_OK;
    }

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->data = ngx_pnalloc(r->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = *(in_port_t *) ((char *) pp + data);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_proxy_protocol_tlv(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t *name = (ngx_str_t *) data;

    ngx_int_t  rc;
    ngx_str_t  tlv, value;

    tlv.len = name->len - (sizeof("proxy_protocol_tlv_") - 1);
    tlv.data = name->data + sizeof("proxy_protocol_tlv_") - 1;

    rc = ngx_proxy_protocol_get_tlv(r->connection, &tlv, &value);

    if (rc == NGX_ERROR) {
        return NGX_ERROR;
    }

    if (rc == NGX_DECLINED) {
        v->not_found = 1;
        return NGX_OK;
    }

    v->len = value.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = value.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_server_addr(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t  s;
    u_char     addr[NGX_SOCKADDR_STRLEN];

    s.len = NGX_SOCKADDR_STRLEN;
    s.data = addr;

    if (ngx_connection_local_sockaddr(r->connection, &s, 0) != NGX_OK) {
        return NGX_ERROR;
    }

    s.data = ngx_pnalloc(r->pool, s.len);
    if (s.data == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(s.data, addr, s.len);

    v->len = s.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = s.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_server_port(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t  port;

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    if (ngx_connection_local_sockaddr(r->connection, NULL, 0) != NGX_OK) {
        return NGX_ERROR;
    }

    v->data = ngx_pnalloc(r->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = ngx_inet_get_port(r->connection->local_sockaddr);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_scheme(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
#if (NGX_HTTP_SSL)

    if (r->connection->ssl) {
        v->len = sizeof("https") - 1;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "https";

        return NGX_OK;
    }

#endif

    v->len = sizeof("http") - 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) "http";

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_https(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
#if (NGX_HTTP_SSL)

    if (r->connection->ssl) {
        v->len = sizeof("on") - 1;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "on";

        return NGX_OK;
    }

#endif

    *v = ngx_http_variable_null_value;

    return NGX_OK;
}


static void
ngx_http_variable_set_args(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    r->args.len = v->len;
    r->args.data = v->data;
    r->valid_unparsed_uri = 0;
}


static ngx_int_t
ngx_http_variable_is_args(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->args.len == 0) {
        *v = ngx_http_variable_null_value;
        return NGX_OK;
    }

    v->len = 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) "?";

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_document_root(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t                  path;
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (clcf->root_lengths == NULL) {
        v->len = clcf->root.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = clcf->root.data;

    } else {
        if (ngx_http_script_run(r, &path, clcf->root_lengths->elts, 0,
                                clcf->root_values->elts)
            == NULL)
        {
            return NGX_ERROR;
        }

        if (ngx_get_full_name(r->pool, (ngx_str_t *) &ngx_cycle->prefix, &path)
            != NGX_OK)
        {
            return NGX_ERROR;
        }

        v->len = path.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = path.data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_realpath_root(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char                    *real;
    size_t                     len;
    ngx_str_t                  path;
    ngx_http_core_loc_conf_t  *clcf;
#if (NGX_HAVE_MAX_PATH)
    u_char                     buffer[NGX_MAX_PATH];
#endif

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (clcf->root_lengths == NULL) {
        path = clcf->root;

    } else {
        if (ngx_http_script_run(r, &path, clcf->root_lengths->elts, 1,
                                clcf->root_values->elts)
            == NULL)
        {
            return NGX_ERROR;
        }

        path.data[path.len - 1] = '\0';

        if (ngx_get_full_name(r->pool, (ngx_str_t *) &ngx_cycle->prefix, &path)
            != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

#if (NGX_HAVE_MAX_PATH)
    real = buffer;
#else
    real = NULL;
#endif

    real = ngx_realpath(path.data, real);

    if (real == NULL) {
        ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno,
                      ngx_realpath_n " \"%s\" failed", path.data);
        return NGX_ERROR;
    }

    len = ngx_strlen(real);

    v->data = ngx_pnalloc(r->pool, len);
    if (v->data == NULL) {
#if !(NGX_HAVE_MAX_PATH)
        ngx_free(real);
#endif
        return NGX_ERROR;
    }

    v->len = len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    ngx_memcpy(v->data, real, len);

#if !(NGX_HAVE_MAX_PATH)
    ngx_free(real);
#endif

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_filename(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    size_t     root;
    ngx_str_t  path;

    if (ngx_http_map_uri_to_path(r, &path, &root, 0) == NULL) {
        return NGX_ERROR;
    }

    /* ngx_http_map_uri_to_path() allocates memory for terminating '\0' */

    v->len = path.len - 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = path.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_server_name(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_http_core_srv_conf_t  *cscf;

    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

    v->len = cscf->server_name.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = cscf->server_name.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_method(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->main->method_name.data) {
        v->len = r->main->method_name.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->main->method_name.data;

    } else {
        v->not_found = 1;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_remote_user(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_int_t  rc;

    rc = ngx_http_auth_basic_user(r);

    if (rc == NGX_DECLINED) {
        v->not_found = 1;
        return NGX_OK;
    }

    if (rc == NGX_ERROR) {
        return NGX_ERROR;
    }

    v->len = r->headers_in.user.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = r->headers_in.user.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_bytes_sent(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%O", r->connection->sent) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_body_bytes_sent(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    off_t    sent;
    u_char  *p;

    sent = r->connection->sent - r->header_size;

    if (sent < 0) {
        sent = 0;
    }

    p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%O", sent) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_pipe(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    v->data = (u_char *) (r->pipeline ? "p" : ".");
    v->len = 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_status(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t  status;

    v->data = ngx_pnalloc(r->pool, NGX_INT_T_LEN);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    if (r->err_status) {
        status = r->err_status;

    } else if (r->headers_out.status) {
        status = r->headers_out.status;

    } else if (r->http_version == NGX_HTTP_VERSION_9) {
        status = 9;

    } else {
        status = 0;
    }

    v->len = ngx_sprintf(v->data, "%03ui", status) - v->data;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_content_type(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->headers_out.content_type.len) {
        v->len = r->headers_out.content_type.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->headers_out.content_type.data;

    } else {
        v->not_found = 1;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_content_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    if (r->headers_out.content_length) {
        v->len = r->headers_out.content_length->value.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->headers_out.content_length->value.data;

        return NGX_OK;
    }

    if (r->headers_out.content_length_n >= 0) {
        p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN);
        if (p == NULL) {
            return NGX_ERROR;
        }

        v->len = ngx_sprintf(p, "%O", r->headers_out.content_length_n) - p;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = p;

        return NGX_OK;
    }

    v->not_found = 1;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_location(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_str_t  name;

    if (r->headers_out.location) {
        v->len = r->headers_out.location->value.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->headers_out.location->value.data;

        return NGX_OK;
    }

    ngx_str_set(&name, "sent_http_location");

    return ngx_http_variable_unknown_header(r, v, &name,
                                            &r->headers_out.headers.part,
                                            sizeof("sent_http_") - 1);
}


static ngx_int_t
ngx_http_variable_sent_last_modified(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    if (r->headers_out.last_modified) {
        v->len = r->headers_out.last_modified->value.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = r->headers_out.last_modified->value.data;

        return NGX_OK;
    }

    if (r->headers_out.last_modified_time >= 0) {
        p = ngx_pnalloc(r->pool, sizeof("Mon, 28 Sep 1970 06:00:00 GMT") - 1);
        if (p == NULL) {
            return NGX_ERROR;
        }

        v->len = ngx_http_time(p, r->headers_out.last_modified_time) - p;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = p;

        return NGX_OK;
    }

    v->not_found = 1;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_connection(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    size_t   len;
    char    *p;

    if (r->headers_out.status == NGX_HTTP_SWITCHING_PROTOCOLS) {
        len = sizeof("upgrade") - 1;
        p = "upgrade";

    } else if (r->keepalive) {
        len = sizeof("keep-alive") - 1;
        p = "keep-alive";

    } else {
        len = sizeof("close") - 1;
        p = "close";
    }

    v->len = len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_keep_alive(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char                    *p;
    ngx_http_core_loc_conf_t  *clcf;

    if (r->keepalive) {
        clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

        if (clcf->keepalive_header) {

            p = ngx_pnalloc(r->pool, sizeof("timeout=") - 1 + NGX_TIME_T_LEN);
            if (p == NULL) {
                return NGX_ERROR;
            }

            v->len = ngx_sprintf(p, "timeout=%T", clcf->keepalive_header) - p;
            v->valid = 1;
            v->no_cacheable = 0;
            v->not_found = 0;
            v->data = p;

            return NGX_OK;
        }
    }

    v->not_found = 1;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_sent_transfer_encoding(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->chunked) {
        v->len = sizeof("chunked") - 1;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "chunked";

    } else {
        v->not_found = 1;
    }

    return NGX_OK;
}


static void
ngx_http_variable_set_limit_rate(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ssize_t    s;
    ngx_str_t  val;

    val.len = v->len;
    val.data = v->data;

    s = ngx_parse_size(&val);

    if (s == NGX_ERROR) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "invalid $limit_rate \"%V\"", &val);
        return;
    }

    r->limit_rate = s;
    r->limit_rate_set = 1;
}


static ngx_int_t
ngx_http_variable_request_completion(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->request_complete) {
        v->len = 2;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "OK";

        return NGX_OK;
    }

    *v = ngx_http_variable_null_value;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_body(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char       *p;
    size_t        len;
    ngx_buf_t    *buf;
    ngx_chain_t  *cl;

    if (r->request_body == NULL
        || r->request_body->bufs == NULL
        || r->request_body->temp_file)
    {
        v->not_found = 1;

        return NGX_OK;
    }

    cl = r->request_body->bufs;
    buf = cl->buf;

    if (cl->next == NULL) {
        v->len = buf->last - buf->pos;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = buf->pos;

        return NGX_OK;
    }

    len = buf->last - buf->pos;
    cl = cl->next;

    for ( /* void */ ; cl; cl = cl->next) {
        buf = cl->buf;
        len += buf->last - buf->pos;
    }

    p = ngx_pnalloc(r->pool, len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->data = p;
    cl = r->request_body->bufs;

    for ( /* void */ ; cl; cl = cl->next) {
        buf = cl->buf;
        p = ngx_cpymem(p, buf->pos, buf->last - buf->pos);
    }

    v->len = len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_body_file(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    if (r->request_body == NULL || r->request_body->temp_file == NULL) {
        v->not_found = 1;

        return NGX_OK;
    }

    v->len = r->request_body->temp_file->file.name.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = r->request_body->temp_file->file.name.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_length(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%O", r->request_length) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_time(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char          *p;
    ngx_time_t      *tp;
    ngx_msec_int_t   ms;

    p = ngx_pnalloc(r->pool, NGX_TIME_T_LEN + 4);
    if (p == NULL) {
        return NGX_ERROR;
    }

    tp = ngx_timeofday();

    ms = (ngx_msec_int_t)
             ((tp->sec - r->start_sec) * 1000 + (tp->msec - r->start_msec));
    ms = ngx_max(ms, 0);

    v->len = ngx_sprintf(p, "%T.%03M", (time_t) ms / 1000, ms % 1000) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_request_id(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *id;

#if (NGX_OPENSSL)
    u_char   random_bytes[16];
#endif

    id = ngx_pnalloc(r->pool, 32);
    if (id == NULL) {
        return NGX_ERROR;
    }

    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->len = 32;
    v->data = id;

#if (NGX_OPENSSL)

    if (RAND_bytes(random_bytes, 16) == 1) {
        ngx_hex_dump(id, random_bytes, 16);
        return NGX_OK;
    }

    ngx_ssl_error(NGX_LOG_ERR, r->connection->log, 0, "RAND_bytes() failed");

#endif

    ngx_sprintf(id, "%08xD%08xD%08xD%08xD",
                (uint32_t) ngx_random(), (uint32_t) ngx_random(),
                (uint32_t) ngx_random(), (uint32_t) ngx_random());

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_connection(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, NGX_ATOMIC_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%uA", r->connection->number) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_connection_requests(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, NGX_INT_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%ui", r->connection->requests) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_connection_time(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char          *p;
    ngx_msec_int_t   ms;

    p = ngx_pnalloc(r->pool, NGX_TIME_T_LEN + 4);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ms = ngx_current_msec - r->connection->start_time;
    ms = ngx_max(ms, 0);

    v->len = ngx_sprintf(p, "%T.%03M", (time_t) ms / 1000, ms % 1000) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_nginx_version(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    v->len = sizeof(NGINX_VERSION) - 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) NGINX_VERSION;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_hostname(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    v->len = ngx_cycle->hostname.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = ngx_cycle->hostname.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_pid(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, NGX_INT64_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%P", ngx_pid) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_msec(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char      *p;
    ngx_time_t  *tp;

    p = ngx_pnalloc(r->pool, NGX_TIME_T_LEN + 4);
    if (p == NULL) {
        return NGX_ERROR;
    }

    tp = ngx_timeofday();

    v->len = ngx_sprintf(p, "%T.%03M", tp->sec, tp->msec) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_time_iso8601(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, ngx_cached_http_log_iso8601.len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(p, ngx_cached_http_log_iso8601.data,
               ngx_cached_http_log_iso8601.len);

    v->len = ngx_cached_http_log_iso8601.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_http_variable_time_local(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(r->pool, ngx_cached_http_log_time.len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(p, ngx_cached_http_log_time.data, ngx_cached_http_log_time.len);

    v->len = ngx_cached_http_log_time.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


void *
ngx_http_map_find(ngx_http_request_t *r, ngx_http_map_t *map, ngx_str_t *match)
{
    void        *value;
    u_char      *low;
    size_t       len;
    ngx_uint_t   key;

    len = match->len;

    if (len) {
        low = ngx_pnalloc(r->pool, len);
        if (low == NULL) {
            return NULL;
        }

    } else {
        low = NULL;
    }

    key = ngx_hash_strlow(low, match->data, len);

    value = ngx_hash_find_combined(&map->hash, key, low, len);
    if (value) {
        return value;
    }

#if (NGX_PCRE)

    if (len && map->nregex) {
        ngx_int_t              n;
        ngx_uint_t             i;
        ngx_http_map_regex_t  *reg;

        reg = map->regex;

        for (i = 0; i < map->nregex; i++) {

            n = ngx_http_regex_exec(r, reg[i].regex, match);

            if (n == NGX_OK) {
                return reg[i].value;
            }

            if (n == NGX_DECLINED) {
                continue;
            }

            /* NGX_ERROR */

            return NULL;
        }
    }

#endif

    return NULL;
}


#if (NGX_PCRE)

static ngx_int_t
ngx_http_variable_not_found(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    v->not_found = 1;
    return NGX_OK;
}


ngx_http_regex_t *
ngx_http_regex_compile(ngx_conf_t *cf, ngx_regex_compile_t *rc)
{
    u_char                     *p;
    size_t                      size;
    ngx_str_t                   name;
    ngx_uint_t                  i, n;
    ngx_http_variable_t        *v;
    ngx_http_regex_t           *re;
    ngx_http_regex_variable_t  *rv;
    ngx_http_core_main_conf_t  *cmcf;

    rc->pool = cf->pool;

    if (ngx_regex_compile(rc) != NGX_OK) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%V", &rc->err);
        return NULL;
    }

    re = ngx_pcalloc(cf->pool, sizeof(ngx_http_regex_t));
    if (re == NULL) {
        return NULL;
    }

    re->regex = rc->regex;
    re->ncaptures = rc->captures;
    re->name = rc->pattern;

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
    cmcf->ncaptures = ngx_max(cmcf->ncaptures, re->ncaptures);

    n = (ngx_uint_t) rc->named_captures;

    if (n == 0) {
        return re;
    }

    rv = ngx_palloc(rc->pool, n * sizeof(ngx_http_regex_variable_t));
    if (rv == NULL) {
        return NULL;
    }

    re->variables = rv;
    re->nvariables = n;

    size = rc->name_size;
    p = rc->names;

    for (i = 0; i < n; i++) {
        rv[i].capture = 2 * ((p[0] << 8) + p[1]);

        name.data = &p[2];
        name.len = ngx_strlen(name.data);

        v = ngx_http_add_variable(cf, &name, NGX_HTTP_VAR_CHANGEABLE);
        if (v == NULL) {
            return NULL;
        }

        rv[i].index = ngx_http_get_variable_index(cf, &name);
        if (rv[i].index == NGX_ERROR) {
            return NULL;
        }

        v->get_handler = ngx_http_variable_not_found;

        p += size;
    }

    return re;
}


ngx_int_t
ngx_http_regex_exec(ngx_http_request_t *r, ngx_http_regex_t *re, ngx_str_t *s)
{
    ngx_int_t                   rc, index;
    ngx_uint_t                  i, n, len;
    ngx_http_variable_value_t  *vv;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    if (re->ncaptures) {
        len = cmcf->ncaptures;

        if (r->captures == NULL || r->realloc_captures) {
            r->realloc_captures = 0;

            r->captures = ngx_palloc(r->pool, len * sizeof(int));
            if (r->captures == NULL) {
                return NGX_ERROR;
            }
        }

    } else {
        len = 0;
    }

    rc = ngx_regex_exec(re->regex, s, r->captures, len);

    if (rc == NGX_REGEX_NO_MATCHED) {
        return NGX_DECLINED;
    }

    if (rc < 0) {
        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
                      ngx_regex_exec_n " failed: %i on \"%V\" using \"%V\"",
                      rc, s, &re->name);
        return NGX_ERROR;
    }

    for (i = 0; i < re->nvariables; i++) {

        n = re->variables[i].capture;
        index = re->variables[i].index;
        vv = &r->variables[index];

        vv->len = r->captures[n + 1] - r->captures[n];
        vv->valid = 1;
        vv->no_cacheable = 0;
        vv->not_found = 0;
        vv->data = &s->data[r->captures[n]];

#if (NGX_DEBUG)
        {
        ngx_http_variable_t  *v;

        v = cmcf->variables.elts;

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http regex set $%V to \"%v\"", &v[index].name, vv);
        }
#endif
    }

    r->ncaptures = rc * 2;
    r->captures_data = s->data;

    return NGX_OK;
}

#endif


ngx_int_t
ngx_http_variables_add_core_vars(ngx_conf_t *cf)
{
    ngx_http_variable_t        *cv, *v;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    cmcf->variables_keys = ngx_pcalloc(cf->temp_pool,
                                       sizeof(ngx_hash_keys_arrays_t));
    if (cmcf->variables_keys == NULL) {
        return NGX_ERROR;
    }

    cmcf->variables_keys->pool = cf->pool;
    cmcf->variables_keys->temp_pool = cf->pool;

    if (ngx_hash_keys_array_init(cmcf->variables_keys, NGX_HASH_SMALL)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    if (ngx_array_init(&cmcf->prefix_variables, cf->pool, 8,
                       sizeof(ngx_http_variable_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    for (cv = ngx_http_core_variables; cv->name.len; cv++) {
        v = ngx_http_add_variable(cf, &cv->name, cv->flags);
        if (v == NULL) {
            return NGX_ERROR;
        }

        *v = *cv;
    }

    return NGX_OK;
}


ngx_int_t
ngx_http_variables_init_vars(ngx_conf_t *cf)
{
    size_t                      len;
    ngx_uint_t                  i, n;
    ngx_hash_key_t             *key;
    ngx_hash_init_t             hash;
    ngx_http_variable_t        *v, *av, *pv;
    ngx_http_core_main_conf_t  *cmcf;

    /* set the handlers for the indexed http variables */

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    v = cmcf->variables.elts;
    pv = cmcf->prefix_variables.elts;
    key = cmcf->variables_keys->keys.elts;

    for (i = 0; i < cmcf->variables.nelts; i++) {

        for (n = 0; n < cmcf->variables_keys->keys.nelts; n++) {

            av = key[n].value;

            if (v[i].name.len == key[n].key.len
                && ngx_strncmp(v[i].name.data, key[n].key.data, v[i].name.len)
                   == 0)
            {
                v[i].get_handler = av->get_handler;
                v[i].data = av->data;

                av->flags |= NGX_HTTP_VAR_INDEXED;
                v[i].flags = av->flags;

                av->index = i;

                if (av->get_handler == NULL
                    || (av->flags & NGX_HTTP_VAR_WEAK))
                {
                    break;
                }

                goto next;
            }
        }

        len = 0;
        av = NULL;

        for (n = 0; n < cmcf->prefix_variables.nelts; n++) {
            if (v[i].name.len >= pv[n].name.len && v[i].name.len > len
                && ngx_strncmp(v[i].name.data, pv[n].name.data, pv[n].name.len)
                   == 0)
            {
                av = &pv[n];
                len = pv[n].name.len;
            }
        }

        if (av) {
            v[i].get_handler = av->get_handler;
            v[i].data = (uintptr_t) &v[i].name;
            v[i].flags = av->flags;

            goto next;
        }

        if (v[i].get_handler == NULL) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "unknown \"%V\" variable", &v[i].name);

            return NGX_ERROR;
        }

    next:
        continue;
    }


    for (n = 0; n < cmcf->variables_keys->keys.nelts; n++) {
        av = key[n].value;

        if (av->flags & NGX_HTTP_VAR_NOHASH) {
            key[n].key.data = NULL;
        }
    }


    hash.hash = &cmcf->variables_hash;
    hash.key = ngx_hash_key;
    hash.max_size = cmcf->variables_hash_max_size;
    hash.bucket_size = cmcf->variables_hash_bucket_size;
    hash.name = "variables_hash";
    hash.pool = cf->pool;
    hash.temp_pool = NULL;

    if (ngx_hash_init(&hash, cmcf->variables_keys->keys.elts,
                      cmcf->variables_keys->keys.nelts)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    cmcf->variables_keys = NULL;

    return NGX_OK;
}