Socket emergency

ruby-talk
1

Hi,

I had a problem when using Winsock in ruby. I tried various ways, but to
no avail. The situation is that I need to write a simple POP3 client
that pool the pop server. This is normally ok. But currently the PC
installed a version or Norman Virus Control which controls the POP3 port
(it is a proxy).

There is something strange with NVC. The symptom is that if I use my
email client to connect to it, that’s fine. If I use windows Telnet, I
only get the “+OK POP3 Server Ready” prompt. After I enter “USER xxx”,
or even “QUIT”, it does NOT reply anything, just hang there.

I tried using the ruby Socket class and TCPSocket class the result is
same. i.e., it will hang when I use the “recv()” method. Please refer to
the following sample code:

irb(main):001:0> require ‘socket’
=> true
irb(main):002:0> t = TCPSocket.new(‘127.0.0.1’, 110)
=> #TCPSocket:0x2aa0230
irb(main):006:0> t.recv(100)
=> "+OK POP3 Server Ready\r\n"
irb(main):007:0> t.send(‘USER xrfang@172.18.2.1\r\n’, 0)
=> 26
irb(main):008:0> t.recv(100)
^CTerminate batch job (Y/N)? ^C

The irb is frozen and I pressed ^C.

Another piece of code:

irb(main):003:0> t = TCPSocket.new(‘127.0.0.1’, 110)
=> #TCPSocket:0x2a94098
irb(main):005:0> t.readline
=> "+OK POP3 Server Ready\r\n"
irb(main):006:0> t.puts(‘USER xrfang@172.18.2.1’)
=> nil
irb(main):007:0> t.readline
=> "+OK\r\n"
irb(main):008:0> t.puts(‘PASS xrfang’)
Errno::EINVAL: Invalid argument
from (irb):8:in write' from (irb):8:inputs’
from (irb):8
irb(main):009:0>

I don’t know why the first “puts” is ok, while the second generated
Errno::EINVAL exception.

I also tried using Socket, not TCPSocket, but the result is similar.

Thank you very much for any advices.

Shannon

···

–
Xiangrong Fang xrfang@hotmail.com

2

irb(main):007:0> t.send('USER xrfang@172.18.2.1\r\n', 0)
=> 26

Be carefull with '' and \r \n

svg% ruby
p 'aa\r\n'.size
p "aa\r\n".size
^D
6
4
svg%

try to use

      t.send("USER xrfang@172.18.2.1\r\n", 0)
     
Guy Decoux

3

Xiangrong Fang wrote:

Hi,

I had a problem when using Winsock in ruby. I tried various ways, but to
no avail. The situation is that I need to write a simple POP3 client
[…]
same. i.e., it will hang when I use the “recv()” method. Please refer to
[…]
irb(main):007:0> t.send(‘USER xrfang@172.18.2.1\r\n’, 0)

Strange this with the telnet, this should work.

I think your code didnt work because of the \r and \n literals in the
msg exchange. So you need to use double-quotes " for the string or
stay with .puts but without the CR LF.

[…]
Thank you very much for any advices.

irb(main):001:0> require ‘socket’
=> true
irb(main):002:0> t = TCPsocket.new(‘mail.avalon.at’,110)
=> #TCPSocket:0x400d1d98
irb(main):003:0> t.readline
=> “+OK ready 13032.1061385513@ns4.avalon.at\r\n”
irb(main):004:0> t.puts(‘USER philipp’)
=> nil
irb(main):005:0> t.readline
=> “+OK Password required for philipp.\r\n”
irb(main):006:0> t.puts(‘PASS test123’)
=> nil
irb(main):007:0> t.readline
=> “-ERR [AUTH] Password supplied for "philipp" is incorrect.\r\n”
irb(main):008:0> t.puts(‘quit’)
=> nil
irb(main):009:0> t.readline
=> “+OK Pop server at ns4.avalon.at signing off.\r\n”

hope it helps
Philipp Ott

4

Hi,

I had a problem when using Winsock in ruby. I tried various ways, but to
no avail. The situation is that I need to write a simple POP3 client
[…]
same. i.e., it will hang when I use the “recv()” method. Please refer to
[…]
irb(main):007:0> t.send(‘USER xrfang@172.18.2.1\r\n’, 0)

Strange this with the telnet, this should work.

I think your code didnt work because of the \r and \n literals in the
msg exchange. So you need to use double-quotes " for the string or
stay with .puts but without the CR LF.

I’m wondering why the net/pop.rb library isn’t sufficient?