lib/msf/core/db_manager/connection.rb
module Msf::DBManager::Connection
# Returns true if we are ready to load/store data
def active
# In a Rails test scenario there will be a connection established already, and it needs to be checked manually to see if a migration is required
# This check normally happens in after_establish_connection, but that might not always get called - for instance during RSpec tests
if Rails.env.test? && migrated.nil? && usable && connection_established?
self.migrated = !needs_migration?
end
# usable and migrated a just Boolean attributes, so check those first because they don't actually contact the
# database.
usable && migrated && connection_established?
end
# Finishes {#connect} after `ApplicationRecord.establish_connection` has succeeded by {#migrate migrating database}
# and setting {#workspace}.
#
# @return [void]
def after_establish_connection(opts={})
begin
# Migrate the database, if needed
migrate(opts)
rescue ::Exception => exception
self.error = exception
elog('DB.connect threw an exception', error: exception)
# remove connection to prevent issues when re-establishing connection
ApplicationRecord.remove_connection
else
# Flag that migration has completed
self.migrated = true
end
end
#
# Connects this instance to a database
#
def connect(opts={})
return false if not @usable
nopts = opts.dup
if (nopts['port'])
nopts['port'] = nopts['port'].to_i
end
# Prefer the config file's pool setting
nopts['pool'] ||= 75
# Prefer the config file's wait_timeout setting too
nopts['wait_timeout'] ||= 300
begin
# Check ApplicationRecord was already connected by Rails::Application.initialize! or some other API.
unless connection_established?
create_db(nopts)
# Configure the database adapter
ApplicationRecord.establish_connection(nopts)
end
rescue ::Exception => e
self.error = e
elog('DB.connect threw an exception', error: e)
return false
ensure
after_establish_connection(nopts)
end
true
end
#
# Attempt to create the database
#
# If the database already exists this will fail and we will continue on our
# merry way, connecting anyway. If it doesn't, we try to create it. If
# that fails, then it wasn't meant to be and the connect will raise a
# useful exception so the user won't be in the dark; no need to raise
# anything at all here.
#
def create_db(opts)
begin
case opts["adapter"]
when 'postgresql'
# Try to force a connection to be made to the database, if it succeeds
# then we know we don't need to create it :)
ApplicationRecord.establish_connection(opts)
# Do the checkout, checkin dance here to make sure this thread doesn't
# hold on to a connection we don't need
conn = ApplicationRecord.connection_pool.checkout
ApplicationRecord.connection_pool.checkin(conn)
end
rescue ::Exception => e
errstr = e.to_s
if errstr =~ /does not exist/i or errstr =~ /Unknown database/
ilog("Database doesn't exist \"#{opts['database']}\", attempting to create it.")
ApplicationRecord.establish_connection(
opts.merge(
'database' => 'postgres',
'schema_search_path' => 'public'
)
)
ApplicationRecord.connection.create_database(opts['database'])
else
ilog("Trying to continue despite failed database creation: #{e}")
end
end
ApplicationRecord.remove_connection
end
# Checks if the spec passed to `ApplicationRecord.establish_connection` can connect to the database.
#
# @return [true] if an active connection can be made to the database using the current config.
# @return [false] if an active connection cannot be made to the database.
def connection_established?
begin
# use with_connection so the connection doesn't stay pinned to the thread.
ApplicationRecord.connection_pool.with_connection {
ApplicationRecord.connection.active?
}
rescue ActiveRecord::ConnectionNotEstablished, PG::ConnectionBad => error
false
end
end
#
# Disconnects a database session
#
def disconnect
begin
ApplicationRecord.remove_connection
self.migrated = nil
self.modules_cached = false
rescue ::Exception => e
self.error = e
elog('DB.disconnect threw an exception:', error: e)
end
end
end