instiki/vendor/plugins/dnsbl_check/lib/dnsbl_check.rb

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2007-01-22 14:43:50 +01:00
# This plugin checks if the client is listed in DNSBLs (DNS Blackhole Lists).
# These are lists of IP addresses misbehaving. There are many DNSBLs, some are more
# aggressive than others. More information at http://en.wikipedia.org/wiki/DNSBL
#
# This plugin will perform one DNS request per client per blocklist.
# This plugin will deny service to clients those blocklists have listed.
# Whether any of this is acceptable is up to you.
#
# mailto:joost@spacebabies.nl
# License: MIT License, like Rails.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
# Version 1.2
# http://www.spacebabies.nl/dnsbl_check
require 'resolv'
module DNSBL_Check
$dnsbl_passed ||= []
DNSBLS = %w{list.dsbl.org bl.spamcop.net sbl-xbl.spamhaus.org}
private
# Filter to check if the client is listed. This will be run before all requests.
def dnsbl_check
return true if $dnsbl_passed.include? request.remote_addr
passed = true
threads = []
request.remote_addr =~ /(\d+).(\d+).(\d+).(\d+)/
# Check the remote address against each dnsbl in a separate thread
DNSBLS.each do |dnsbl|
threads << Thread.new("#$4.#$3.#$2.#$1.#{dnsbl}") do |host|
logger.warn("Checking DNSBL #{host}")
addr = Resolv.getaddress("#{host}") rescue ''
if addr[0,7]=="127.0.0"
logger.info("#{request.remote_addr} found using DNSBL #{host}")
passed = false
end
end
end
threads.each {|thread| thread.join(2)} # join threads, but use timeout to kill blocked ones
# Add client ip to global passed cache if no dnsbls objected. else deny service.
if passed
$dnsbl_passed = $dnsbl_passed[0,49].unshift request.remote_addr
logger.warn("#{request.remote_addr} added to DNSBL passed cache")
else
render :text => 'Access denied', :status => 403
return false
end
end
end