mod_log_config.c

apache简化版

/* ====================================================================
 * Copyright (c) 1995-1998 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

/*
 * Modified by [e-mail]:
 * If no TransferLog is given explicitly, decline to log.
 *
 * This is module implements the TransferLog directive (same as the
 * common log module), and additional directives, LogFormat and CustomLog.
 *
 *
 * Syntax:
 *
 *    TransferLog fn      Logs transfers to fn in standard log format, unless
 *                        a custom format is set with LogFormat
 *    LogFormat format    Set a log format from TransferLog files
 *    CustomLog fn format
 *                        Log to file fn with format given by the format
 *                        argument
 *
 *    CookieLog fn        For backwards compatability with old Cookie
 *                        logging module - now deprecated.
 *
 * There can be any number of TransferLog and CustomLog
 * commands. Each request will be logged to _ALL_ the
 * named files, in the appropriate format.
 *
 * If no TransferLog or CustomLog directive appears in a VirtualHost,
 * the request will be logged to the log file(s) defined outside
 * the virtual host section. If a TransferLog or CustomLog directive
 * appears in the VirtualHost section, the log files defined outside
 * the VirtualHost will _not_ be used. This makes this module compatable
 * with the CLF and config log modules, where the use of TransferLog
 * inside the VirtualHost section overrides its use outside.
 * 
 * Examples:
 *
 *    TransferLog    logs/access_log
 *    <VirtualHost>
 *    LogFormat      "... custom format ..."
 *    TransferLog    log/virtual_only
 *    CustomLog      log/virtual_useragents "%t %{user-agent}i"
 *    </VirtualHost>
 *
 * This will log using CLF to access_log any requests handled by the
 * main server, while any requests to the virtual host will be logged
 * with the "... custom format..." to virtual_only _AND_ using
 * the custom user-agent log to virtual_useragents.
 *
 * Note that the NCSA referer and user-agent logs are easily added with
 * CustomLog:
 *   CustomLog   logs/referer  "%{referer}i -> %U"
 *   CustomLog   logs/agent    "%{user-agent}i"
 *
 * Except: no RefererIgnore functionality
 *         logs '-' if no Referer or User-Agent instead of nothing
 *
 * But using this method allows much easier modification of the
 * log format, e.g. to log hosts along with UA:
 *   CustomLog   logs/referer "%{referer}i %U %h"
 *
 * The argument to LogFormat and CustomLog is a string, which can include
 * literal characters copied into the log files, and '%' directives as
 * follows:
 *
 * %...b:  bytes sent, excluding HTTP headers.
 * %...{FOOBAR}e:  The contents of the environment variable FOOBAR
 * %...f:  filename
 * %...h:  remote host
 * %...a:  remote IP-address
 * %...{Foobar}i:  The contents of Foobar: header line(s) in the request
 *                 sent to the client.
 * %...l:  remote logname (from identd, if supplied)
 * %...{Foobar}n:  The contents of note "Foobar" from another module.
 * %...{Foobar}o:  The contents of Foobar: header line(s) in the reply.
 * %...p:  the port the request was served to
 * %...P:  the process ID of the child that serviced the request.
 * %...r:  first line of request
 * %...s:  status.  For requests that got internally redirected, this
 *         is status of the *original* request --- %...>s for the last.
 * %...t:  time, in common log format time format
 * %...{format}t:  The time, in the form given by format, which should
 *                 be in strftime(3) format.
 * %...T:  the time taken to serve the request, in seconds.
 * %...u:  remote user (from auth; may be bogus if return status (%s) is 401)
 * %...U:  the URL path requested.
 * %...v:  the name of the server (i.e. which virtual host?)
 *
 * The '...' can be nothing at all (e.g. "%h %u %r %s %b"), or it can
 * indicate conditions for inclusion of the item (which will cause it
 * to be replaced with '-' if the condition is not met).  Note that
 * there is no escaping performed on the strings from %r, %...i and
 * %...o; some with long memories may remember that I thought this was
 * a bad idea, once upon a time, and I'm still not comfortable with
 * it, but it is difficult to see how to "do the right thing" with all
 * of '%..i', unless we URL-escape everything and break with CLF.
 *
 * The forms of condition are a list of HTTP status codes, which may
 * or may not be preceded by '!'.  Thus, '%400,501{User-agent}i' logs
 * User-agent: on 400 errors and 501 errors (Bad Request, Not
 * Implemented) only; '%!200,304,302{Referer}i' logs Referer: on all
 * requests which did *not* return some sort of normal status.
 *
 * The default LogFormat reproduces CLF; see below.
 *
 * The way this is supposed to work with virtual hosts is as follows:
 * a virtual host can have its own LogFormat, or its own TransferLog.
 * If it doesn't have its own LogFormat, it inherits from the main
 * server.  If it doesn't have its own TransferLog, it writes to the
 * same descriptor (meaning the same process for "| ...").
 *
 * --- rst */

#define DEFAULT_LOG_FORMAT "%h %l %u %t \"%r\" %>s %b"

#include "httpd.h"
#include "http_config.h"
#include "http_core.h"          /* For REMOTE_NAME */
#include "http_log.h"
#include <limits.h>

module MODULE_VAR_EXPORT config_log_module;

static int xfer_flags = (O_WRONLY | O_APPEND | O_CREAT);
#if defined(OS2) || defined(WIN32)
/* OS/2 dosen't support users and groups */
static mode_t xfer_mode = (S_IREAD | S_IWRITE);
#else
static mode_t xfer_mode = (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
#endif

/* POSIX.1 defines PIPE_BUF as the maximum number of bytes that is
 * guaranteed to be atomic when writing a pipe.  And PIPE_BUF >= 512
 * is guaranteed.  So we'll just guess 512 in the event the system
 * doesn't have this.  Now, for file writes there is actually no limit,
 * the entire write is atomic.  Whether all systems implement this
 * correctly is another question entirely ... so we'll just use PIPE_BUF
 * because it's probably a good guess as to what is implemented correctly
 * everywhere.
 */
#ifdef PIPE_BUF
#define LOG_BUFSIZE     PIPE_BUF
#else
#define LOG_BUFSIZE     (512)
#endif

/*
 * multi_log_state is our per-(virtual)-server configuration. We store
 * an array of the logs we are going to use, each of type config_log_state.
 * If a default log format is given by LogFormat, store in default_format
 * (backward compat. with mod_log_config).  We also store for each virtual
 * server a pointer to the logs specified for the main server, so that if this
 * vhost has no logs defined, we can use the main server's logs instead.
 *
 * So, for the main server, config_logs contains a list of the log files
 * and server_config_logs in empty. For a vhost, server_config_logs
 * points to the same array as config_logs in the main server, and
 * config_logs points to the array of logs defined inside this vhost,
 * which might be empty.
 */

typedef struct {
    char *default_format_string;
    array_header *default_format;
    array_header *config_logs;
    array_header *server_config_logs;
    table *formats;
} multi_log_state;

/*
 * config_log_state holds the status of a single log file. fname might
 * be NULL, which means this module does no logging for this
 * request. format might be NULL, in which case the default_format
 * from the multi_log_state should be used, or if that is NULL as
 * well, use the CLF. log_fd is -1 before the log file is opened and
 * set to a valid fd after it is opened.
 */

typedef struct {
    char *fname;
    char *format_string;
    array_header *format;
    int log_fd;
#ifdef BUFFERED_LOGS
    int outcnt;
    char outbuf[LOG_BUFSIZE];
#endif
} config_log_state;

/*
 * Format items...
 * Note that many of these could have ap_sprintfs replaced with static buffers.
 */

typedef const char *(*item_key_func) (request_rec *, char *);

typedef struct {
    item_key_func func;
    char *arg;
    int condition_sense;
    int want_orig;
    array_header *conditions;
} log_format_item;

static char *format_integer(pool *p, int i)
{
    return ap_psprintf(p, "%d", i);
}

static char *pfmt(pool *p, int i)
{
    if (i <= 0) {
        return "-";
    }
    else {
        return format_integer(p, i);
    }
}

static const char *constant_item(request_rec *dummy, char *stuff)
{
    return stuff;
}

static const char *log_remote_host(request_rec *r, char *a)
{
    return ap_get_remote_host(r->connection, r->per_dir_config,
                                    REMOTE_NAME);
}

static const char *log_remote_address(request_rec *r, char *a)
{
    return r->connection->remote_ip;
}

static const char *log_remote_logname(request_rec *r, char *a)
{
    return ap_get_remote_logname(r);
}

static const char *log_remote_user(request_rec *r, char *a)
{
    char *rvalue = r->connection->user;

    if (rvalue == NULL) {
        rvalue = "-";
    }
    else if (strlen(rvalue) == 0) {
        rvalue = "\"\"";
    }
    return rvalue;
}

static const char *log_request_line(request_rec *r, char *a)
{
	    /* NOTE: If the original request contained a password, we
	     * re-write the request line here to contain XXXXXX instead:
	     * (note the truncation before the protocol string for HTTP/0.9 requests)
	     * (note also that r->the_request contains the unmodified request)
	     */
    return (r->parsed_uri.password) ? ap_pstrcat(r->pool, r->method, " ",
					 ap_unparse_uri_components(r->pool, &r->parsed_uri, 0),
					 r->assbackwards ? NULL : " ", r->protocol, NULL)
					: r->the_request;
}

static const char *log_request_file(request_rec *r, char *a)
{
    return r->filename;
}
static const char *log_request_uri(request_rec *r, char *a)
{
    return r->uri;
}
static const char *log_status(request_rec *r, char *a)
{
    return pfmt(r->pool, r->status);
}

static const char *log_bytes_sent(request_rec *r, char *a)
{
    if (!r->sent_bodyct) {
        return "-";
    }
    else {
        long int bs;
        ap_bgetopt(r->connection->client, BO_BYTECT, &bs);
	return ap_psprintf(r->pool, "%ld", bs);
    }
}

static const char *log_header_in(request_rec *r, char *a)
{
    return ap_table_get(r->headers_in, a);
}