diff --git a/lib/resolv.rb b/lib/resolv.rb index 73410f1..c84c172 100644 --- a/lib/resolv.rb +++ b/lib/resolv.rb @@ -720,7 +720,8 @@ def request(sender, tout) begin reply, from = recv_reply(select_result[0]) rescue Errno::ECONNREFUSED, # GNU/Linux, FreeBSD - Errno::ECONNRESET # Windows + Errno::ECONNRESET, # Windows + EOFError # No name server running on the server? # Don't wait anymore. raise ResolvTimeout @@ -929,8 +930,11 @@ def initialize(host, port=Port) end def recv_reply(readable_socks) - len = readable_socks[0].read(2).unpack('n')[0] + len_data = readable_socks[0].read(2) + raise EOFError if len_data.nil? || len_data.bytesize != 2 + len = len_data.unpack('n')[0] reply = @socks[0].read(len) + raise EOFError if reply.nil? || reply.bytesize != len return reply, nil end diff --git a/test/resolv/test_dns.rb b/test/resolv/test_dns.rb index 2bb8061..a91800b 100644 --- a/test/resolv/test_dns.rb +++ b/test/resolv/test_dns.rb @@ -822,4 +822,124 @@ def test_multiple_servers_with_timeout_and_truncated_tcp_fallback end end end + + def test_tcp_connection_closed_before_length + with_tcp('127.0.0.1', 0) do |t| + _, server_port, _, server_address = t.addr + + server_thread = Thread.new do + ct = t.accept + ct.recv(512) + ct.close + end + + client_thread = Thread.new do + requester = Resolv::DNS::Requester::TCP.new(server_address, server_port) + begin + msg = Resolv::DNS::Message.new + msg.add_question('example.org', Resolv::DNS::Resource::IN::A) + sender = requester.sender(msg, msg) + assert_raise(Resolv::ResolvTimeout) do + requester.request(sender, 2) + end + ensure + requester.close + end + end + + server_thread.join + client_thread.join + end + end + + def test_tcp_connection_closed_after_length + with_tcp('127.0.0.1', 0) do |t| + _, server_port, _, server_address = t.addr + + server_thread = Thread.new do + ct = t.accept + ct.recv(512) + ct.send([100].pack('n'), 0) + ct.close + end + + client_thread = Thread.new do + requester = Resolv::DNS::Requester::TCP.new(server_address, server_port) + begin + msg = Resolv::DNS::Message.new + msg.add_question('example.org', Resolv::DNS::Resource::IN::A) + sender = requester.sender(msg, msg) + assert_raise(Resolv::ResolvTimeout) do + requester.request(sender, 2) + end + ensure + requester.close + end + end + + server_thread.join + client_thread.join + end + end + + def test_tcp_connection_closed_with_partial_length_prefix + with_tcp('127.0.0.1', 0) do |t| + _, server_port, _, server_address = t.addr + + server_thread = Thread.new do + ct = t.accept + ct.recv(512) + ct.write "A" # 1 byte + ct.close + end + + client_thread = Thread.new do + requester = Resolv::DNS::Requester::TCP.new(server_address, server_port) + begin + msg = Resolv::DNS::Message.new + msg.add_question('example.org', Resolv::DNS::Resource::IN::A) + sender = requester.sender(msg, msg) + assert_raise(Resolv::ResolvTimeout) do + requester.request(sender, 2) + end + ensure + requester.close + end + end + + server_thread.join + client_thread.join + end + end + + def test_tcp_connection_closed_with_partial_message_body + with_tcp('127.0.0.1', 0) do |t| + _, server_port, _, server_address = t.addr + + server_thread = Thread.new do + ct = t.accept + ct.recv(512) + ct.write([10].pack('n')) # length 10 + ct.write "12345" # 5 bytes (partial) + ct.close + end + + client_thread = Thread.new do + requester = Resolv::DNS::Requester::TCP.new(server_address, server_port) + begin + msg = Resolv::DNS::Message.new + msg.add_question('example.org', Resolv::DNS::Resource::IN::A) + sender = requester.sender(msg, msg) + assert_raise(Resolv::ResolvTimeout) do + requester.request(sender, 2) + end + ensure + requester.close + end + end + + server_thread.join + client_thread.join + end + end end