/* * squid_session: Squid external acl helper for tracking sessions * * Copyright (C) 2006 Henrik Nordstrom <henrik@henriknordstrom.net> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. *  * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. *  * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. */#ifdef HAVE_CONFIG_H#include "config.h"#endif#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <time.h>#if defined(HAVE_DB_185_H)#include <db_185.h>#elif defined(HAVE_DB_H)#include <db.h>#else#include <db_185.h>#endifstatic int session_ttl = 3600;char *db_path = NULL;const char *program_name;DB *db = NULL;static void init_db(void){    db = dbopen(db_path, O_CREAT | O_RDWR, 0666, DB_BTREE, NULL);    if (!db) {	fprintf(stderr, "%s: Failed to open session db '%s'\n", program_name, db_path);	exit(1);    }}static void shutdown_db(void){    db->close(db);}int session_is_active = 0;static int session_active(const char *details){    DBT key, data;    key.data = (void *)details;    key.size = strlen(details);    if (db->get(db, &key, &data, 0) == 0) {	time_t timestamp;	if (data.size != sizeof(timestamp)) {	    fprintf(stderr, "%s: CORRUPTED DATABASE (%s)\n", program_name, details);	    db->del(db, &key, 0);	    return 0;	}	memcpy(&timestamp, data.data, sizeof(timestamp));	if (timestamp + session_ttl >= time(NULL))	    return 1;    }    return 0;}static void session_login(const char *details){    DBT key, data;    time_t now = time(NULL);    key.data = (void *)details;    key.size = strlen(details);    data.data = &now;    data.size = sizeof(now);    db->put(db, &key, &data, 0);}static void session_logout(const char *details){    DBT key;    key.data = (void *)details;    key.size = strlen(details);    db->del(db, &key, 0);}static void usage(void){    fprintf(stderr, "Usage: %s [-t session_timeout] [-b dbpath] [-a]\n", program_name);    fprintf(stderr, "	-t sessiontimeout	Idle timeout after which sessions will be forgotten\n");    fprintf(stderr, "	-b dbpath		Path where persistent session database will be kept\n");    fprintf(stderr, "	-a			Active mode requiring LOGIN argument to start a session\n");}int main(int argc, char **argv){    char request[256];    int opt;    int default_action = 1;    program_name = argv[0];    while ((opt = getopt(argc, argv, "t:b:a?")) != -1) {	switch(opt) {	case 't':	    session_ttl = strtol(optarg, NULL, 0);	    break;	case 'b':	    db_path = optarg;	    break;	case 'a':	    default_action = 0;	    break;	case '?':	    usage();	    exit(0);	    break;	}    }    setbuf(stdout, NULL);    init_db();    while (fgets(request, sizeof(request), stdin)) {	const char *index, *detail;	char *lastdetail;	int action = 0;	index = strtok(request, " \n");	detail = strtok(NULL, "\n");	lastdetail = strrchr(detail, ' ');	if (lastdetail) {	    if (strcmp(lastdetail, " LOGIN") == 0) {		*lastdetail++ = '\0';		action = 1;	    } else if (strcmp(lastdetail, " LOGOUT") == 0) {		action = -1;		*lastdetail++ = '\0';	    }	}	if (action == -1) {	    session_logout(detail);	    printf("%s OK message=\"Bye\"\n", index);	} else if (action == 1) {	    session_login(detail);	    printf("%s OK message=\"Welcome\"\n", index);	} else if (session_active(detail)) {	    session_login(detail);	    printf("%s OK\n", index);	} else if (default_action == 1) {	    session_login(detail);	    printf("%s ERR message=\"Welcome\"\n", index);	} else {	    printf("%s ERR message=\"No session available\"\n", index);	}    }    shutdown_db();    return 0;}