Net::Config - Local configuration data for libnet
- use Net::Config qw(%NetConfig);
Net::Config
holds configuration data for the modules in the libnet
distribution. During installation you will be asked for these values.
The configuration data is held globally in a file in the perl installation
tree, but a user may override any of these values by providing their own. This
can be done by having a .libnetrc
file in their home directory. This file
should return a reference to a HASH containing the keys described below.
For example
Net::Config
defines the following methods. They are methods as they are
invoked as class methods. This is because Net::Config
inherits from
Net::LocalCfg
so you can override these methods if you want.
Attempts to determine if a given host is outside your firewall. Possible return values are.
- -1 Cannot lookup hostname
- 0 Host is inside firewall (or there is no ftp_firewall entry)
- 1 Host is outside the firewall
This is done by using hostname lookup and the local_netmask
entry in
the configuration data.
Each is a reference to an array of hostnames (in order of preference), which should be used for the given protocol
Your internet domain name
If you have an FTP proxy firewall (NOT an HTTP or SOCKS firewall)
then this value should be set to the firewall hostname. If your firewall
does not listen to port 21, then this value should be set to
"hostname:port"
(eg "hostname:99"
)
There are many different ftp firewall products available. But unfortunately there is no standard for how to traverse a firewall. The list below shows the sequence of commands that Net::FTP will use
- user Username for remote host
- pass Password for remote host
- fwuser Username for firewall
- fwpass Password for firewall
- remote.host The hostname of the remote ftp server
There is no firewall
- USER user@remote.host
- PASS pass
- USER fwuser
- PASS fwpass
- USER user@remote.host
- PASS pass
- USER fwuser
- PASS fwpass
- SITE remote.site
- USER user
- PASS pass
- USER fwuser
- PASS fwpass
- OPEN remote.site
- USER user
- PASS pass
- USER user@fwuser@remote.site
- PASS pass@fwpass
- USER fwuser@remote.site
- PASS fwpass
- USER user
- PASS pass
- USER user@remote.host
- PASS pass
- AUTH fwuser
- RESP fwpass
FTP servers can work in passive or active mode. Active mode is when you want to transfer data you have to tell the server the address and port to connect to. Passive mode is when the server provide the address and port and you establish the connection.
With some firewalls active mode does not work as the server cannot
connect to your machine (because you are behind a firewall) and the firewall
does not re-write the command. In this case you should set ftp_ext_passive
to a true value.
Some servers are configured to only work in passive mode. If you have
one of these you can force Net::FTP
to always transfer in passive
mode; when not going via a firewall, by setting ftp_int_passive
to
a true value.
A reference to a list of netmask strings in the form "134.99.4.0/24"
.
These are used by the requires_firewall
function to determine if a given
host is inside or outside your firewall.
The following entries are used during installation & testing on the libnet package