openGauss: Setting the Maximum Number of Concurrent Connections to the Database

# Copyright (C) 2020 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.150337");
  script_version("2020-11-12T12:33:52+0000");
  script_tag(name:"last_modification", value:"2020-11-12 12:33:52 +0000 (Thu, 12 Nov 2020)");
  script_tag(name:"creation_date", value:"2020-11-11 15:21:37 +0000 (Wed, 11 Nov 2020)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:S/C:N/I:N/A:N");
  script_tag(name:"qod", value:"97");

  script_name("openGauss: Setting the Maximum Number of Concurrent Connections to the Database");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
  script_family("Policy");
  script_dependencies("gb_huawei_opengauss_ssh_login_detect.nasl", "compliance_tests.nasl", "opengauss_authentication_information.nasl");
  script_mandatory_keys("huawei/opengauss/detected", "Compliance/Launch");

  script_xref(name:"URL", value:"https://opengauss.org");

  script_tag(name:"summary", value:"max_connections specifies the maximum concurrent connections to the database.
Increasing the value of this parameter may cause openGauss to request System V
to share more memory or semaphore. If this occurs, the shared memory or
semaphore will exceed the default value allowed by the OS. When increasing the
value of this parameter, you need to adjust the value of max_pool_size to ensure
that the value of max_pool_size is greater than that of max_connections.");

  exit(0);
}

include( "policy_functions.inc" );
include( "ssh_func.inc" );

cmd = "SELECT name,setting FROM pg_settings WHERE name = 'max_connections';";
title = "Setting the Maximum Number of Concurrent Connections to the Database";
solution = "Set max_connections to 800 in the postgresql.conf file and then restart the database.";
default = "1-800";
test_type = "SQL_Query";

if( ! get_kb_item( "login/SSH/success" ) || ! sock = ssh_login_or_reuse_connection() ) {
  compliant = "incomplete";
  value = "error";
  comment = "No SSH connection to host";
}else if ( ! value = policy_gsql_cmd( socket:sock, query:cmd ) ) {
  compliant = "incomplete";
  value = "error";
  comment = "SQL command did not return anything";
}else if ( value =~ "failed to connect" ) {
  compliant = "incomplete";
  value = "error";
  comment = "No connection to database";
}else{
  value = ereg_replace( string:chomp(value), pattern:"^\s+", replace:"" );
  setting = eregmatch( string:value, pattern:"max_connections\s+\|\s+([0-9]+)" );
  if( ! setting[1] ){
    compliant = "incomplete";
    comment = "Can not determine setting.";
  }else{
    compliant = policy_setting_in_range( value:setting[1], min:"1", max:"800" );
  }
}

policy_reporting( result:value, default:default, compliant:compliant, fixtext:solution,
  type:test_type, test:cmd, info:comment );

policy_set_kbs( type:test_type, cmd:cmd, default:default, solution:solution, title:title,
  value:value, compliant:compliant );

exit( 0 );