helpers/external_acl/session/ext_session_acl.cc

   1 /*
   2  * ext_session_acl: 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 #if HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24 #include "helpers/defines.h"
  25
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <fcntl.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #if HAVE_UNISTD_H
  32 #include <unistd.h>
  33 #endif
  34 #include <string.h>
  35 #include <time.h>
  36 #if HAVE_GETOPT_H
  37 #include <getopt.h>
  38 #endif
  39
  40 /* At this point all Bit Types are already defined, so we must
  41    protect from multiple type definition on platform where
  42    __BIT_TYPES_DEFINED__ is not defined.
  43  */
  44 #ifndef        __BIT_TYPES_DEFINED__
  45 #define        __BIT_TYPES_DEFINED__
  46 #endif
  47
  48 #if HAVE_DB_185_H
  49 #include <db_185.h>
  50 #elif HAVE_DB_H
  51 #include <db.h>
  52 #endif
  53
  54 static int session_ttl = 3600;
  55 static int fixed_timeout = 0;
  56 char *db_path = NULL;
  57 const char *program_name;
  58
  59 DB *db = NULL;
  60
  61 static void init_db(void)
  62 {
  63     db = dbopen(db_path, O_CREAT | O_RDWR, 0666, DB_BTREE, NULL);
  64     if (!db) {
  65         fprintf(stderr, "FATAL: %s: Failed to open session db '%s'\n", program_name, db_path);
  66         exit(1);
  67     }
  68 }
  69
  70 static void shutdown_db(void)
  71 {
  72     db->close(db);
  73 }
  74
  75 int session_is_active = 0;
  76
  77 static int session_active(const char *details, size_t len)
  78 {
  79     DBT key, data;
  80     key.data = (void *)details;
  81     key.size = len;
  82     if (db->get(db, &key, &data, 0) == 0) {
  83         time_t timestamp;
  84         if (data.size != sizeof(timestamp)) {
  85             fprintf(stderr, "ERROR: %s: CORRUPTED DATABASE (%s)\n", program_name, details);
  86             db->del(db, &key, 0);
  87             return 0;
  88         }
  89         memcpy(&timestamp, data.data, sizeof(timestamp));
  90         if (timestamp + session_ttl >= time(NULL))
  91             return 1;
  92     }
  93     return 0;
  94 }
  95
  96 static void session_login(const char *details, size_t len)
  97 {
  98     DBT key, data;
  99     time_t now = time(NULL);
 100     key.data = (void *)details;
 101     key.size = len;
 102     data.data = &now;
 103     data.size = sizeof(now);
 104     db->put(db, &key, &data, 0);
 105     db->sync(db, 0);
 106 }
 107
 108 static void session_logout(const char *details, size_t len)
 109 {
 110     DBT key;
 111     key.data = (void *)details;
 112     key.size = len;
 113     db->del(db, &key, 0);
 114 }
 115
 116 static void usage(void)
 117 {
 118     fprintf(stderr, "Usage: %s [-t|-T session_timeout] [-b dbpath] [-a]\n", program_name);
 119     fprintf(stderr, "   -t sessiontimeout       Idle timeout after which sessions will be forgotten (user activity will reset)\n");
 120     fprintf(stderr, "   -T sessiontimeout       Fixed timeout after which sessions will be forgotten (regardless of user activity)\n");
 121     fprintf(stderr, "   -b dbpath               Path where persistent session database will be kept\n");
 122     fprintf(stderr, "   -a                      Active mode requiring LOGIN argument to start a session\n");
 123 }
 124 int main(int argc, char **argv)
 125 {
 126     char request[HELPER_INPUT_BUFFER];
 127     int opt;
 128     int default_action = 1;
 129
 130     program_name = argv[0];
 131
 132     while ((opt = getopt(argc, argv, "t:T:b:a?")) != -1) {
 133         switch (opt) {
 134         case 'T':
 135             fixed_timeout = 1;
 136         case 't':
 137             session_ttl = strtol(optarg, NULL, 0);
 138             break;
 139         case 'b':
 140             db_path = optarg;
 141             break;
 142         case 'a':
 143             default_action = 0;
 144             break;
 145         case '?':
 146             usage();
 147             exit(0);
 148             break;
 149         }
 150     }
 151
 152     setbuf(stdout, NULL);
 153
 154     init_db();
 155
 156     while (fgets(request, HELPER_INPUT_BUFFER, stdin)) {
 157         int action = 0;
 158         const char *channel_id = strtok(request, " ");
 159         const char *detail = strtok(NULL, "\n");
 160         if (detail == NULL) {
 161             // Only 1 paramater supplied. We are expecting at least 2 (including the channel ID)
 162             fprintf(stderr, "FATAL: %s is concurrent and requires the concurrency option to be specified.\n", program_name);
 163             exit(1);
 164         }
 165         const char *lastdetail = strrchr(detail, ' ');
 166         size_t detail_len = strlen(detail);
 167         if (lastdetail) {
 168             if (strcmp(lastdetail, " LOGIN") == 0) {
 169                 action = 1;
 170                 detail_len = (size_t)(lastdetail-detail);
 171             } else if (strcmp(lastdetail, " LOGOUT") == 0) {
 172                 action = -1;
 173                 detail_len = (size_t)(lastdetail-detail);
 174             }
 175         }
 176         if (action == -1) {
 177             session_logout(detail, detail_len);
 178             printf("%s OK message=\"Bye\"\n", channel_id);
 179         } else if (action == 1) {
 180             session_login(detail, detail_len);
 181             printf("%s OK message=\"Welcome\"\n", channel_id);
 182         } else if (session_active(detail, detail_len)) {
 183             if (fixed_timeout == 0) {
 184                 session_login(detail, detail_len);
 185             }
 186             printf("%s OK\n", channel_id);
 187         } else if (default_action == 1) {
 188             session_login(detail, detail_len);
 189             printf("%s ERR message=\"Welcome\"\n", channel_id);
 190         } else {
 191             printf("%s ERR message=\"No session available\"\n", channel_id);
 192         }
 193     }
 194     shutdown_db();
 195     return 0;
 196 }