Bug #8285 ยป ruby-trunk-8285-resolv-tcp-fallback-fix.diff
| lib/resolv.rb (working copy) | ||
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def fetch_resource(name, typeclass)
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lazy_initialize
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requester = make_udp_requester
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protocols = {}
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requesters = {}
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senders = {}
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begin
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@config.resolv(name) {|candidate, tout, nameserver, port|
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msg = Message.new
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msg.rd = 1
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msg.add_question(candidate, typeclass)
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unless sender = senders[[candidate, nameserver, port]]
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sender = senders[[candidate, nameserver, port]] =
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protocol = protocols[candidate| ||= :udp
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requester = requesters[[protocol, nameserver]] ||= case protocol
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when :udp then make_udp_requester
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when :tcp then make_tcp_requester(nameserver, port)
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end
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sender = senders[[candidate, requester, nameserver, port]] ||=
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requester.sender(msg, candidate, nameserver, port)
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end
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reply, reply_name = requester.request(sender, tout)
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case reply.rcode
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when RCode::NoError
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if reply.tc == 1 and not Requester::TCP === requester
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requester.close
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if protocol == :udp and reply.tc == 1
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# Retry via TCP:
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requester = make_tcp_requester(nameserver, port)
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senders = {}
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# This will use TCP for all remaining candidates (assuming the
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# current candidate does not already respond successfully via
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# TCP). This makes sense because we already know the full
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# response will not fit in an untruncated UDP packet.
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protocols[candidate] = :tcp
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redo
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else
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yield(reply, reply_name)
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| ... | ... | |
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end
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}
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ensure
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requester.close
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requesters.each_value { |requester| requester.close }
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end
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end
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def make_udp_requester # :nodoc:
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nameserver_port = @config.nameserver_port
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| ... | ... | |
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def make_tcp_requester(host, port) # :nodoc:
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return Requester::TCP.new(host, port)
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rescue Errno::ECONNREFUSED
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# Treat a refused TCP connection attempt to a nameserver like a timeout,
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# as Resolv::DNS::Config#resolv considers ResolvTimeout exceptions as a
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# hint to try the next nameserver:
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raise ResolvTimeout
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end
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def extract_resources(msg, name, typeclass) # :nodoc:
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