mod_usertrack.c

C编写的用来实现search engine的推荐功能

/* Copyright 1999-2005 The Apache Software Foundation or its licensors, as
 * applicable.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* User Tracking Module (Was mod_cookies.c)
 *
 * *** IMPORTANT NOTE: This module is not designed to generate
 * *** cryptographically secure cookies.  This means you should not
 * *** use cookies generated by this module for authentication purposes
 *
 * This Apache module is designed to track users paths through a site.
 * It uses the client-side state ("Cookie") protocol developed by Netscape.
 * It is known to work on most browsers.
 *
 * Each time a page is requested we look to see if the browser is sending
 * us a Cookie: header that we previously generated.
 *
 * If we don't find one then the user hasn't been to this site since
 * starting their browser or their browser doesn't support cookies.  So
 * we generate a unique Cookie for the transaction and send it back to
 * the browser (via a "Set-Cookie" header)
 * Future requests from the same browser should keep the same Cookie line.
 *
 * By matching up all the requests with the same cookie you can
 * work out exactly what path a user took through your site.  To log
 * the cookie use the " %{Cookie}n " directive in a custom access log;
 *
 * Example 1 : If you currently use the standard Log file format (CLF)
 * and use the command "TransferLog somefilename", add the line
 *       LogFormat "%h %l %u %t \"%r\" %s %b %{Cookie}n"
 * to your config file.
 *
 * Example 2 : If you used to use the old "CookieLog" directive, you
 * can emulate it by adding the following command to your config file
 *       CustomLog filename "%{Cookie}n \"%r\" %t"
 *
 * Mark Cox, [e-mail], 6 July 95
 *
 * This file replaces mod_cookies.c
 */

#include "apr.h"
#include "apr_lib.h"
#include "apr_strings.h"

#define APR_WANT_STRFUNC
#include "apr_want.h"

#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_request.h"
//added by zhiyong to record the user session
#include <gdbm.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
char session_gdbm[256] = "/home/zhiyong/software/apache2/cgi-bin/session.gdbm";


module AP_MODULE_DECLARE_DATA usertrack_module;

typedef struct {
    int always;
    int expires;
} cookie_log_state;

typedef enum {
    CT_UNSET,
    CT_NETSCAPE,
    CT_COOKIE,
    CT_COOKIE2
} cookie_type_e;

typedef struct {
    int enabled;
    cookie_type_e style;
    char *cookie_name;
    char *cookie_domain;
    char *regexp_string;  /* used to compile regexp; save for debugging */
    regex_t *regexp;  /* used to find usertrack cookie in cookie header */
} cookie_dir_rec;

/* Make Cookie: Now we have to generate something that is going to be
 * pretty unique.  We can base it on the pid, time, hostip */

#define COOKIE_NAME "Apache"

static void make_cookie(request_rec *r)
{
    cookie_log_state *cls = ap_get_module_config(r->server->module_config,
						 &usertrack_module);
    /* 1024 == hardcoded constant */
    char cookiebuf[1024];
    char *new_cookie;
    const char *rname = ap_get_remote_host(r->connection, r->per_dir_config,
					   REMOTE_NAME, NULL);
    cookie_dir_rec *dcfg;

    dcfg = ap_get_module_config(r->per_dir_config, &usertrack_module);

    /* XXX: hmm, this should really tie in with mod_unique_id */
    apr_snprintf(cookiebuf, sizeof(cookiebuf), "%s.%" APR_TIME_T_FMT, rname, 
                 apr_time_now());

    if (cls->expires) {

        /* Cookie with date; as strftime '%a, %d-%h-%y %H:%M:%S GMT' */
        new_cookie = apr_psprintf(r->pool, "%s=%s; path=/",
                                  dcfg->cookie_name, cookiebuf);

        if ((dcfg->style == CT_UNSET) || (dcfg->style == CT_NETSCAPE)) {
	    apr_time_exp_t tms;
            apr_time_exp_gmt(&tms, r->request_time 
                                 + apr_time_from_sec(cls->expires));
            new_cookie = apr_psprintf(r->pool,
                                       "%s; expires=%s, "
                                       "%.2d-%s-%.2d %.2d:%.2d:%.2d GMT",
                                       new_cookie, apr_day_snames[tms.tm_wday],
                                       tms.tm_mday,
                                       apr_month_snames[tms.tm_mon],
                                       tms.tm_year % 100,
                                       tms.tm_hour, tms.tm_min, tms.tm_sec);
        }
        else {
            new_cookie = apr_psprintf(r->pool, "%s; max-age=%d",
                                      new_cookie, cls->expires);
        }
    }
    else {
        new_cookie = apr_psprintf(r->pool, "%s=%s; path=/",
                                  dcfg->cookie_name, cookiebuf);
    }
    if (dcfg->cookie_domain != NULL) {
        new_cookie = apr_pstrcat(r->pool, new_cookie, "; domain=",
                                 dcfg->cookie_domain,
                                 (dcfg->style == CT_COOKIE2
                                  ? "; version=1"
                                  : ""),
                                 NULL);
    }

    apr_table_addn(r->headers_out,
                   (dcfg->style == CT_COOKIE2 ? "Set-Cookie2" : "Set-Cookie"),
                   new_cookie);
    apr_table_setn(r->notes, "cookie", apr_pstrdup(r->pool, cookiebuf));   /* log first time */
    return;
}

/* dcfg->regexp is "^cookie_name=([^;]+)|;[ \t]+cookie_name=([^;]+)",
 * which has three subexpressions, $0..$2 */
#define NUM_SUBS 3

static void set_and_comp_regexp(cookie_dir_rec *dcfg, 
                                apr_pool_t *p,
                                const char *cookie_name) 
{
    int danger_chars = 0;
    const char *sp = cookie_name;

    /* The goal is to end up with this regexp, 
     * ^cookie_name=([^;]+)|;[\t]+cookie_name=([^;]+) 
     * with cookie_name obviously substituted either
     * with the real cookie name set by the user in httpd.conf, or with the
     * default COOKIE_NAME.
     */

    /* Anyway, we need to escape the cookie_name before pasting it
     * into the regex
     */
    while (*sp) {
        if (!apr_isalnum(*sp)) {
            ++danger_chars;
        }
        ++sp;
    }

    if (danger_chars) {
        char *cp;
        cp = apr_palloc(p, sp - cookie_name + danger_chars + 1); /* 1 == \0 */
        sp = cookie_name;
        cookie_name = cp;
        while (*sp) {
            if (!apr_isalnum(*sp)) {
                *cp++ = '\\';
            }
            *cp++ = *sp++;
        }
        *cp = '\0';
    }

    dcfg->regexp_string = apr_pstrcat(p, "^",
                                      cookie_name,
                                      "=([^;]+)|;[ \t]+",
                                      cookie_name,
                                      "=([^;]+)", NULL);

    dcfg->regexp = ap_pregcomp(p, dcfg->regexp_string, REG_EXTENDED);
    ap_assert(dcfg->regexp != NULL);
}

static int spot_cookie(request_rec *r)
{
    cookie_dir_rec *dcfg = ap_get_module_config(r->per_dir_config,
						&usertrack_module);
    const char *cookie_header;
    regmatch_t regm[NUM_SUBS];

	//the following is added by zhiyong to record the user session
	int iRet;
	char sessionID[256];
	char sessionURL[256];
	char linkType[256];
	char* ptr = NULL;
	FILE *fp = NULL;
	GDBM_FILE db = NULL;
	datum name;
	datum value;
	char sessions[2048];
	
	
	//zhiyong
		
    /* Do not run in subrequests */
    if (!dcfg->enabled || r->main) {
        return DECLINED;
    }
	
    if ((cookie_header = apr_table_get(r->headers_in, "Cookie"))) {
        if (!ap_regexec(dcfg->regexp, cookie_header, NUM_SUBS, regm, 0)) {
            char *cookieval = NULL;
            /* Our regexp,
             * ^cookie_name=([^;]+)|;[ \t]+cookie_name=([^;]+)
             * only allows for $1 or $2 to be available. ($0 is always
             * filled with the entire matched expression, not just
             * the part in parentheses.) So just check for either one
             * and assign to cookieval if present. */
            if (regm[1].rm_so != -1) {
                cookieval = ap_pregsub(r->pool, "$1", cookie_header,
                                       NUM_SUBS, regm);
            }
            if (regm[2].rm_so != -1) {
                cookieval = ap_pregsub(r->pool, "$2", cookie_header,
                                       NUM_SUBS, regm);
            }
            /* Set the cookie in a note, for logging */
            apr_table_setn(r->notes, "cookie", cookieval);
			
			//the following are added by zhiyong to record the session in gdbm lib
			//if the request is not html file, skip			
			//strcpy(linkType, r->content_type);
			//if(strcmp(linkType, "text/html")) return DECLINED;
			strcpy(sessionID, cookieval);
			strcpy(sessionURL, r->uri);
			if((strstr(sessionURL, ".htm")==NULL)&&(strstr(sessionURL, ".HTM")==NULL)) return DECLINED;
			//create gdbm lib file if non-exist