Index: sb-config.h.in
===================================================================
--- sb-config.h.in	(revision 29)
+++ sb-config.h.in	(working copy)
@@ -82,10 +82,6 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
-/* Define to the sub-directory in which libtool stores uninstalled libraries.
-   */
-#undef LT_OBJDIR
-
 /* Name of package */
 #undef PACKAGE
 
Index: gw/sqlbox_sdb.c
===================================================================
--- gw/sqlbox_sdb.c	(revision 29)
+++ gw/sqlbox_sdb.c	(working copy)
@@ -413,6 +413,7 @@
     res->sql_leave = sdb_leave;
     res->sql_fetch_msg = sdb_fetch_msg;
     res->sql_save_msg = sdb_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 #endif
Index: gw/sqlbox.c
===================================================================
--- gw/sqlbox.c	(revision 29)
+++ gw/sqlbox.c	(working copy)
@@ -86,6 +86,7 @@
 static Octstr *box_allow_ip;
 static Octstr *box_deny_ip;
 static Octstr *global_sender;
+static int checkbalance;
 
 #ifndef HAVE_MSSQL
 #ifndef HAVE_MYSQL
@@ -149,6 +150,10 @@
     return 0;
 }
 
+#undef OCTSTR
+#undef SINGLE_GROUP
+#undef MULTI_GROUP
+
 static int sqlbox_is_single_group(Octstr *query)
 {
     #define OCTSTR(name)
@@ -253,6 +258,7 @@
 {
     Boxc *conn = arg;
     Msg *msg;
+    int hasbalance;
 
     /* remove messages from socket until it is closed */
     while (sqlbox_status != SQL_DEAD && conn->alive) {
@@ -266,13 +272,22 @@
             break;
         }
 
+	hasbalance = 1;
+
         if (msg_type(msg) == sms) {
             debug("sqlbox", 0, "smsbox_to_bearerbox: sms received");
 
-            gw_sql_save_msg(msg, octstr_imm("MT"));
+	    if (checkbalance && NULL != gw_sql_check_balance) {
+		hasbalance = gw_sql_check_balance(msg);
+	    }
+            if (hasbalance) {
+		gw_sql_save_msg(msg, octstr_imm("MT"));
+	    }
         }
 
-        send_msg(conn->bearerbox_connection, conn, msg);
+        if (hasbalance) {
+	    send_msg(conn->bearerbox_connection, conn, msg);
+	}
         /* if this is an identification message from an smsbox instance */
         if (msg_type(msg) == admin && msg->admin.command == cmd_identify) {
             /*
@@ -528,6 +543,7 @@
     Boxc *boxc;
     int fd;
     Msg *msg;
+    int hasbalance;
 
     boxc = gw_malloc(sizeof(Boxc));
     boxc->bearerbox_connection = connect_to_bearerbox_real(bearerbox_host, bearerbox_port, bearerbox_port_ssl, NULL /* bb_our_host */);
@@ -546,12 +562,18 @@
     identify_to_bearerbox(boxc);
 
     while (sqlbox_status == SQL_RUNNING) {
+	hasbalance = 1;
         if ((msg = gw_sql_fetch_msg()) != NULL) {
             if (global_sender != NULL && (msg->sms.sender == NULL || octstr_len(msg->sms.sender) == 0)) {
                 msg->sms.sender = octstr_duplicate(global_sender);
             }
-            send_msg(boxc->bearerbox_connection, boxc, msg);
-            gw_sql_save_msg(msg, octstr_imm("MT"));
+	    if (checkbalance && NULL != gw_sql_check_balance) {
+		hasbalance = gw_sql_check_balance(msg);
+	    }
+            if (hasbalance) {
+		send_msg(boxc->bearerbox_connection, boxc, msg);
+		gw_sql_save_msg(msg, octstr_imm("MT"));
+	    }
         }
         else {
             gwthread_sleep(SLEEP_BETWEEN_SELECTS);
@@ -658,6 +680,7 @@
     bearerbox_port_ssl = 0;
     logfile = NULL;
     lvl = 0;
+    checkbalance = 0;
 
     /*
      * first we take the port number in bearerbox and other values from the
@@ -697,10 +720,17 @@
         octstr_destroy(logfile);
     }
 
+    cfg_get_bool(&checkbalance, grp, octstr_imm("check-balance"));
+
     sql_type = sqlbox_init_sql(cfg);
     if (sql_type == NULL) {
         panic(0, "No proper SQL server defined.");
     }
+
+    if (checkbalance && NULL == gw_sql_check_balance) {
+        panic(0, "Prepaid functionality not implemented for this db engine.");
+    }
+
     gw_sql_enter(cfg);
 
     sqlbox_status = SQL_RUNNING;
Index: gw/sqlbox_sqlite3.c
===================================================================
--- gw/sqlbox_sqlite3.c	(revision 29)
+++ gw/sqlbox_sqlite3.c	(working copy)
@@ -315,6 +315,7 @@
     res->sql_leave = sqlite3_leave;
     res->sql_fetch_msg = sqlite3_fetch_msg;
     res->sql_save_msg = sqlite3_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 #endif
Index: gw/sqlbox_pgsql.c
===================================================================
--- gw/sqlbox_pgsql.c	(revision 29)
+++ gw/sqlbox_pgsql.c	(working copy)
@@ -377,6 +377,7 @@
     res->sql_leave = pgsql_leave;
     res->sql_fetch_msg = pgsql_fetch_msg;
     res->sql_save_msg = pgsql_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 
Index: gw/sqlbox-cfg.def
===================================================================
--- gw/sqlbox-cfg.def	(revision 29)
+++ gw/sqlbox-cfg.def	(working copy)
@@ -17,6 +17,7 @@
     OCTSTR(log-file)
     OCTSTR(log-level)
     OCTSTR(bearerbox-port)
+    OCTSTR(check-balance)
     OCTSTR(ssl-client-certkey-file)
     OCTSTR(ssl-server-cert-file)
     OCTSTR(ssl-server-key-file)
Index: gw/sqlbox_mssql.c
===================================================================
--- gw/sqlbox_mssql.c	(revision 29)
+++ gw/sqlbox_mssql.c	(working copy)
@@ -294,6 +294,7 @@
     res->sql_leave = mssql_leave;
     res->sql_fetch_msg = mssql_fetch_msg;
     res->sql_save_msg = mssql_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 #endif
Index: gw/sqlbox_sqlite.c
===================================================================
--- gw/sqlbox_sqlite.c	(revision 29)
+++ gw/sqlbox_sqlite.c	(working copy)
@@ -323,6 +323,7 @@
     res->sql_leave = sqlite_leave;
     res->sql_fetch_msg = sqlite_fetch_msg;
     res->sql_save_msg = sqlite_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 #endif
Index: gw/sqlbox_sql.h
===================================================================
--- gw/sqlbox_sql.h	(revision 29)
+++ gw/sqlbox_sql.h	(working copy)
@@ -16,6 +16,7 @@
     void (*sql_leave) ();
     Msg *(*sql_fetch_msg) ();
     void (*sql_save_msg) (Msg *, Octstr *);
+    int (*sql_check_balance) (Msg *);
 };
 
 struct sqlbox_db_queries {
@@ -41,6 +42,7 @@
 #define gw_sql_save_msg sql_type->sql_save_msg
 #define gw_sql_enter sql_type->sql_enter
 #define gw_sql_leave sql_type->sql_leave
+#define gw_sql_check_balance sql_type->sql_check_balance
 
 /* Macro to run the queries to create tables */
 #define sqlbox_run_query(query, table) \
Index: gw/sqlbox_oracle.c
===================================================================
--- gw/sqlbox_oracle.c	(revision 29)
+++ gw/sqlbox_oracle.c	(working copy)
@@ -315,6 +315,7 @@
     res->sql_leave = oracle_leave;
     res->sql_fetch_msg = oracle_fetch_msg;
     res->sql_save_msg = oracle_save_msg;
+    res->sql_check_balance = NULL;
     return res;
 }
 #endif
Index: gw/sqlbox_mysql.c
===================================================================
--- gw/sqlbox_mysql.c	(revision 29)
+++ gw/sqlbox_mysql.c	(working copy)
@@ -39,6 +39,31 @@
     dbpool_conn_produce(pc);
 }
 
+static int mysql_update_affected_rows(const Octstr *sql)
+{
+    int state, result;
+    DBPoolConn *pc;
+
+#if defined(SQLBOX_TRACE)
+     debug("SQLBOX", 0, "sql: %s", octstr_get_cstr(sql));
+#endif
+
+    pc = dbpool_conn_consume(pool);
+    if (pc == NULL) {
+        error(0, "MYSQL: Database pool got no connection! DB update failed!");
+        return;
+    }
+
+    state = mysql_query(pc->conn, octstr_get_cstr(sql));
+    result = mysql_affected_rows(pc->conn);
+    if (state != 0)
+        error(0, "MYSQL: %s", mysql_error(pc->conn));
+
+    dbpool_conn_produce(pc);
+
+    return result;
+}
+
 static MYSQL_RES* mysql_select(const Octstr *sql)
 {
     int state;
@@ -212,6 +237,39 @@
     octstr_destroy(sql);
 }
 
+int mysql_check_balance(Msg *msg)
+{
+    Octstr *sql;
+    double rate;
+    int affected_rows;
+    MYSQL_RES *res;
+    MYSQL_ROW row;
+
+    if (NULL == msg->sms.smsc_id) {
+	sql = octstr_format("select rate from sms_rates where '%s' regexp prefix", octstr_get_cstr(msg->sms.receiver));
+    }
+    else {
+	sql = octstr_format("select rate from sms_rates where smsc='%s' and '%s' regexp prefix", octstr_get_cstr(msg->sms.smsc_id), octstr_get_cstr(msg->sms.receiver));
+    }
+    res = mysql_select(sql);
+    octstr_destroy(sql);
+    if (res == NULL) {
+        debug("sqlbox", 0, "SQL statement failed: %s", octstr_get_cstr(sql));
+	return 1;
+    }
+    if (mysql_num_rows(res) != 1) {
+	debug("sqlbox", 0, "SQL statement did not return exactly one row: %s", octstr_get_cstr(sql));
+	return 1;
+    }
+    row = mysql_fetch_row(res);
+    rate = atof(row[0]);
+    mysql_free_result(res);
+    sql = octstr_format("update sms_users set balance = balance - %f where binfo='%s' and balance >= %f", rate, octstr_get_cstr(msg->sms.binfo), rate);
+    affected_rows = mysql_update_affected_rows(sql);
+    octstr_destroy(sql);
+    return affected_rows > 0;
+}
+
 void mysql_leave()
 {
     dbpool_destroy(pool);
@@ -310,6 +368,7 @@
     res->sql_leave = mysql_leave;
     res->sql_fetch_msg = mysql_fetch_msg;
     res->sql_save_msg = mysql_save_msg;
+    res->sql_check_balance = mysql_check_balance;
     return res;
 }
 #endif