Bug#624500: libnet-server-perl: $self->{server}->{sock} elements no longer report port numbers after a HUP

[Daniel Kahn Gillmor]

Package: libnet-server-perl
Version: 0.99-1
Severity: normal

With libnet-server-perl 0.97-1, i can discover the auto-assigned port
number in post_bind_hook, and it work after a HUP as well (though the
FD of the socket changes).

With 0.99-1, i see no way to extract this information after a HUP.
This causes serious problems with the msva-perl package, which
currently dies after a HUP because it can't find the assigned port
number.

Here's example code to inspect the bound sockets for auto-assigned
ports:

------------------------------------
0 dkg at pip:~$ cat testdaemonsimple.pl
#!/usr/bin/env perl

use strict;
use warnings;

{
  package TestNetServer;
  use base qw(Net::Server::Fork);
  use Data::Dumper;

  sub post_bind_hook {
    my $self = shift;
    # if we got here, then the binding was successful.
    for my $sock (@{$self->{server}->{sock}}) {
      printf STDERR ("port: %s %s\n", $sock->show(), Dumper( [ $sock, $sock->NS_port, $sock->sockport() ] ));
    }
  }
};

TestNetServer->run(port => 0);
0 dkg at pip:$ cat inspect
#!/bin/sh
 perl ./testdaemonsimple.pl &
 sleep 2
 lsof -p $(jobs -p %1) | grep IP
 kill -HUP %1
 sleep 2
 lsof -p $(jobs -p %1) | grep IP
 kill %1
 wait
0 dkg at pip:~$ 
------------------------------------

Here are the results at start and after a HUP, with Net::Server 0.97:

-----------------------------------
0 dkg at pip:~$ ./inspect
2011/04/28-23:12:27 TestNetServer (type Net::Server::Fork) starting! pid(10293)
Binding to TCP port 0 on host *
port: Ref = "Net::Server::Proto::TCP"
  NS_proto = "TCP"
  NS_port = "0"
  NS_host = "*"
 $VAR1 = [
          bless( \*Symbol::GEN0, 'Net::Server::Proto::TCP' ),
          '0',
          37534
        ];

Group Not Defined.  Defaulting to EGID '1000 4 20 24 25 27 29 44 46 107 109 110 115 126 1000'
User Not Defined.  Defaulting to EUID '1000'
perl    10293  dkg    3u  IPv4 846239      0t0    TCP *:37534 (LISTEN)
2011/04/28-23:12:28 Server closing!
2011/04/28-23:12:28 HUP'ing server
2011/04/28-23:12:29 TestNetServer (type Net::Server::Fork) starting! pid(10293)
Binding open file descriptors
Binding to TCP port 0 on host *
port: Ref = "Net::Server::Proto::TCP"
  NS_proto = "TCP"
  NS_port = "0"
  NS_host = "*"
 $VAR1 = [
          bless( \*Symbol::GEN0, 'Net::Server::Proto::TCP' ),
          '0',
          37534
        ];

Group Not Defined.  Defaulting to EGID '1000 4 20 24 25 27 29 44 46 107 109 110 115 126 1000'
User Not Defined.  Defaulting to EUID '1000'
perl    10293  dkg    4u  IPv4 846239      0t0    TCP *:37534 (LISTEN)
2011/04/28-23:12:30 Server closing!
0 dkg at pip:~$ 
-----------------------------------


And here is the same thing after upgrading to 0.99-1:

-----------------------------------
0 dkg at pip:~$ ./inspect
2011/04/28-23:11:34 TestNetServer (type Net::Server::Fork) starting! pid(10173)
Using default listen value of 128
Binding to TCP port 0 on host *
Bound to auto-assigned port 54014
port: Ref = "Net::Server::Proto::TCP"
  NS_proto = "TCP"
  NS_port = "54014"
  NS_host = "*"
 $VAR1 = [
          bless( \*Symbol::GEN0, 'Net::Server::Proto::TCP' ),
          54014,
          54014
        ];

Group Not Defined.  Defaulting to EGID '1000 4 20 24 25 27 29 44 46 107 109 110 115 126 1000'
User Not Defined.  Defaulting to EUID '1000'
perl    10173  dkg    3u  IPv4 845957      0t0    TCP *:54014 (LISTEN)
2011/04/28-23:11:36 Server closing!
2011/04/28-23:11:36 HUP'ing server
2011/04/28-23:11:36 TestNetServer (type Net::Server::Fork) starting! pid(10173)
Using default listen value of 128
Binding open file descriptors
port: Ref = "Net::Server::Proto::TCP"
  NS_proto = "TCP"
  NS_port = "0"
  NS_host = "*"
 $VAR1 = [
          bless( \*Symbol::GEN0, 'Net::Server::Proto::TCP' ),
          '0',
          undef
        ];

Group Not Defined.  Defaulting to EGID '1000 4 20 24 25 27 29 44 46 107 109 110 115 126 1000'
User Not Defined.  Defaulting to EUID '1000'
perl    10173  dkg    4u  IPv4 845957      0t0    TCP *:54014 (LISTEN)
2011/04/28-23:11:38 Server closing!
0 dkg at pip:~$ 
-----------------------------------

Note that inspection works to determine the port number on the first
connection, but does *not* work after a HUP.

There needs to be some way to retrieve the port number after a HUP
when using an auto-assigned port.

Let me know if i can help debug this further.

Thanks for keeping Net::Server up-to-date in debian!

     --dkg

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (500, 'testing'), (200, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.38-2-686 (SMP w/1 CPU core)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libnet-server-perl depends on:
ii  libio-multiplex-perl          1.13-1     object-oriented interface to selec
ii  libnet-cidr-perl              0.14-1     Manipulate IPv4/IPv6 netblocks in 
ii  perl                          5.10.1-20  Larry Wall's Practical Extraction 

libnet-server-perl recommends no packages.

Versions of packages libnet-server-perl suggests:
ii  libio-socket-ssl-perl         1.39-1     Perl module implementing object or

-- no debconf information