helpers/external_acl/session/squid_session.c

   1 /*
   2  * squid_session: Squid external acl helper for tracking sessions
   3  *
   4  * Copyright (C) 2006 Henrik Nordstrom <henrik@henriknordstrom.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #if HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33 #include <string.h>
  34 #include <time.h>
  35 #if HAVE_GETOPT_H
  36 #include <getopt.h>
  37 #endif
  38
  39 #if defined(HAVE_DB_185_H)
  40 #include <db_185.h>
  41 #elif defined(HAVE_DB_H)
  42 #include <db.h>
  43 #else
  44 #include <db_185.h>
  45 #endif
  46
  47 static int session_ttl = 3600;
  48 char *db_path = NULL;
  49 const char *program_name;
  50
  51 DB *db = NULL;
  52
  53 static void init_db(void)
  54 {
  55     db = dbopen(db_path, O_CREAT | O_RDWR, 0666, DB_BTREE, NULL);
  56     if (!db) {
  57         fprintf(stderr, "%s: Failed to open session db '%s'\n", program_name, db_path);
  58         exit(1);
  59     }
  60 }
  61
  62 static void shutdown_db(void)
  63 {
  64     db->close(db);
  65 }
  66
  67 int session_is_active = 0;
  68
  69 static int session_active(const char *details)
  70 {
  71     DBT key, data;
  72     key.data = (void *)details;
  73     key.size = strlen(details);
  74     if (db->get(db, &key, &data, 0) == 0) {
  75         time_t timestamp;
  76         if (data.size != sizeof(timestamp)) {
  77             fprintf(stderr, "%s: CORRUPTED DATABASE (%s)\n", program_name, details);
  78             db->del(db, &key, 0);
  79             return 0;
  80         }
  81         memcpy(&timestamp, data.data, sizeof(timestamp));
  82         if (timestamp + session_ttl >= time(NULL))
  83             return 1;
  84     }
  85     return 0;
  86 }
  87
  88 static void session_login(const char *details)
  89 {
  90     DBT key, data;
  91     time_t now = time(NULL);
  92     key.data = (void *)details;
  93     key.size = strlen(details);
  94     data.data = &now;
  95     data.size = sizeof(now);
  96     db->put(db, &key, &data, 0);
  97 }
  98
  99 static void session_logout(const char *details)
 100 {
 101     DBT key;
 102     key.data = (void *)details;
 103     key.size = strlen(details);
 104     db->del(db, &key, 0);
 105 }
 106
 107 static void usage(void)
 108 {
 109     fprintf(stderr, "Usage: %s [-t session_timeout] [-b dbpath] [-a]\n", program_name);
 110     fprintf(stderr, "   -t sessiontimeout       Idle timeout after which sessions will be forgotten\n");
 111     fprintf(stderr, "   -b dbpath               Path where persistent session database will be kept\n");
 112     fprintf(stderr, "   -a                      Active mode requiring LOGIN argument to start a session\n");
 113 }
 114 int main(int argc, char **argv)
 115 {
 116     char request[256];
 117     int opt;
 118     int default_action = 1;
 119
 120     program_name = argv[0];
 121
 122     while ((opt = getopt(argc, argv, "t:b:a?")) != -1) {
 123         switch(opt) {
 124         case 't':
 125             session_ttl = strtol(optarg, NULL, 0);
 126             break;
 127         case 'b':
 128             db_path = optarg;
 129             break;
 130         case 'a':
 131             default_action = 0;
 132             break;
 133         case '?':
 134             usage();
 135             exit(0);
 136             break;
 137         }
 138     }
 139
 140     setbuf(stdout, NULL);
 141
 142     init_db();
 143
 144     while (fgets(request, sizeof(request), stdin)) {
 145         const char *index, *detail;
 146         char *lastdetail;
 147         int action = 0;
 148         index = strtok(request, " \n");
 149         detail = strtok(NULL, "\n");
 150         lastdetail = strrchr(detail, ' ');
 151         if (lastdetail) {
 152             if (strcmp(lastdetail, " LOGIN") == 0) {
 153                 *lastdetail++ = '\0';
 154                 action = 1;
 155             } else if (strcmp(lastdetail, " LOGOUT") == 0) {
 156                 action = -1;
 157                 *lastdetail++ = '\0';
 158             }
 159         }
 160         if (action == -1) {
 161             session_logout(detail);
 162             printf("%s OK message=\"Bye\"\n", index);
 163         } else if (action == 1) {
 164             session_login(detail);
 165             printf("%s OK message=\"Welcome\"\n", index);
 166         } else if (session_active(detail)) {
 167             session_login(detail);
 168             printf("%s OK\n", index);
 169         } else if (default_action == 1) {
 170             session_login(detail);
 171             printf("%s ERR message=\"Welcome\"\n", index);
 172         } else {
 173             printf("%s ERR message=\"No session available\"\n", index);
 174         }
 175     }
 176     shutdown_db();
 177     return 0;
 178 }