[Net::FTPServer] NetFTPServer - BugFix - New Features - request for feedback

[Yair Lenga]

Greetings,

We have recenetly deployed Net-FTPServer. During the deployment  we made 
several changes to the code to make the server more friendly with agressive 
firewalls and FTP clients. I would like to commit those changes back into 
future releases. Attached below is a summary of changes. I will appreciate any 
feedback. I have sent separate email regarding some of the issues in the past 2 
months - I apologize the the duplication.

I have all the code changes ready for submission. I hope that all the changes 
are acceptable.

Thanks,
Yair

- High Priority items - bugs

1. Fix MDTM to use GMTIME.
The proposed FTP extension 
http://www.ietf.org/internet-drafts/draft-ietf-ftpext-mlst-16.txt, section 3.4 (MDTM 
example) specified "The times are in GMT, ... The
location where the file was modified, and consequently the local wall clock time at 
that location, is not available.". To make the code comply with the spec, a 
change in _MDTM_command as follows:

6630c6635
<     my $fmt_time = strftime "%Y%m%d%H%M%S", localtime ($time);
---
>     my $fmt_time = strftime "%Y%m%d%H%M%S", gmtime ($time);

2. Binding to service name under chroot.
When Net::FTPServer is chroot-ing to the user home directory, it is 
currently not possible to use service name to specify the port to bind - 
when the /etc/services files was used. The suggested solution (other 
than using service numbers), is to remember the translated port number 
(config option "ftp data port") - in the _drop_privs procedure) in the 
server object: (line ~4727), and use it in _PASV_command and 
open_data_connection.

($self->{ftpdataport} = scalar getservbyname($ftpdata,"tcp"))) >= 1024

3. Binding to specific interface card.
When Net::FTPServer is running on a server with multiple network cards - 
with active connection - it will create the data connection without 
specifying "localAddr" - creating the connection on the first available 
address. If the FTP client can only access the second interface, it will 
not be able to setup the data connection. The bug fix is to add to 
missing LocalAddr to open_data_connection (line ~7300, and line ~7312)
              LocalAddr => $self->{sockaddrstring},

4. Symbolic links to directories:
Net::FTPServer will die when trying to access a symbolic link to a 
directory. This is caused because Net/FTPServer/Full/DirHandle is using 
'stat' in the get method, and lstat in the 'status' method - causing 
inconsisnt handling of those links. The solution is to use lstat in the 
'get' method (line ~82).

- New Features:

1. Allow date components (%Y, %d, ...) to be used in the 'error' and 
'xfer' logging.
This option will allow the log files to include %Y, %m, ... to create 
date base log files. This is similar to ncftpd. The implementation is to 
use the following simple functions to resolve a file name. The code was 
also changed to make check if the log file has to be switched when 
running the server in deamon mode.

sub resolve_log_file_name {
       my ($self, $log_file) = @_ ;

       $log_file =~ s/\$(\w+)/$self->{$1}/g
               if $log_file =~ /\$/ ;
       $log_file = strftime($log_file, localtime())
               if $log_file =~ /\%/ ;
       return $log_file;
}

2. Controllable delay for unauthenticate user.
This option allow us to disable the 5 seconds delay for unathorized 
access. The server can be access from other applications that are hosted 
on our own server. For certain hosts, the delay is not required.

3. Easier subclassing
Extending the server to use new "personality" require simple 
implementation of the 'root_directory_hook' method. However, extending 
the existing DirHandle module (i.e. Full/DirHandle.pm) require complete 
reimplemnation of the get method. The proposed change will add a new 
'file_handle_hook' that will be used to create instances of file 
handles. With this change, there will be no need to hard code the 
'Net::FTPServer::Full::DirHandle' classes in the DirHandle module. 
Instead the code will look like:

sub get {
   # find out if we need to have a directory or file object
   if ( directory object) {
         return $self->new(...)
   } else {
         return $self->ftps->file_handle_hook(...)
   }
}




--

Yair Lenga
Vice President
The Yield Book
Phone: 212-816-7468
Fax: 212-816-7766
Email: address@hidden
Citigroup Global Markets Inc.