Net::Server::Proto(3p)

NAME
Net::Server::Proto - Net::Server Protocol compatibility layer

SYNOPSIS
    NOTE: beginning in Net::Server 2.005, the default value for
          ipv is IPv* meaning that if no host is passed, or
          a hostname is past, all available socket types will be
          bound.  You can force IPv4 only by adding an ipv => 4
          configuration in any of the half dozen ways we let you
          specify it.

    # Net::Server::Proto and its accompanying modules are not
    # intended to be used outside the scope of Net::Server.

    # That being said, here is how you use them.  This is
    # only intended for anybody wishing to extend the
    # protocols to include some other set (ie maybe a
    # database connection protocol)

    use Net::Server::Proto;

    my @info = Net::Server::Proto->parse_info(
        $port,            # port to connect to
        $default_host,    # host to use if none found in port
        $default_proto,   # proto to use if none found in port
        $default_ipv,     # default of IPv6 or IPv4 if none found in port
        $server_obj,      # Net::Server object
    );

    my @raw_info = Net::Server::Proto->get_addr_info($host, $port, $proto);
    # returns arrayref of resolved ips, ports, and ipv values

    my $sock = Net::Server::Proto->object({
        port  => $port,
        host  => $host,
        proto => $proto,
        ipv   => $ipv, # * (IPv*) if false (default false)
    }, $server);

    # Net::Server::Proto will attempt to interface with
    # sub modules named similar to Net::Server::Proto::TCP
    # Individual sub modules will be loaded by
    # Net::Server::Proto as they are needed.

    use Net::Server::Proto::TCP; # or UDP or UNIX etc

    # Return an object which is a sub class of IO::Socket
    # At this point the object is not connected.
    # The method can gather any other information that it
    # needs from the server object.
    my $sock = Net::Server::Proto::TCP->object({
        port  => $port,
        host  => $host,
        proto => $proto,
        ipv   => 6, # IPv6 - default is * - can also be '4'
    }, $server);

    # Log that a connection is about to occur.
    # Use the facilities of the passed Net::Server object.
    $sock->log_connect( $server );

    # Actually bind to port or socket file.  This
    # is typically done by calling the configure method.
    $sock->connect();

    # Allow for rebinding to an already open fileno.
    # Typically will just do an fdopen.
    $sock->reconnect();

    ### Return a unique identifying string for this sock that
    # can be used when reconnecting.
    my $str = $sock->hup_string();

    # Return the proto that is being used by this module.
    my $proto = $sock->NS_proto();

DESCRIPTION
Net::Server::Proto is an intermediate module which returns IO::Socket style objects blessed into its own set of classes (ie Net::Server::Proto::TCP, Net::Server::Proto::UNIX).

Only three or four protocols come bundled with Net::Server. TCP, UDP, UNIX, UNIXDGRAM, and SSLEAY. TCP is an implementation of SOCK_STREAM across an INET socket. UDP is an implementation of SOCK_DGRAM across an INET socket. UNIX uses a unix style socket file with the SOCK_STREAM protocol. UNIXGRAM uses a unix style socket file with the SOCK_DGRAM protocol. SSLEAY is actually just a layer on top of TCP but uses Net::SSLeay to read and write from the stream.

The protocol that is passed to Net::Server can be the name of another module which contains the protocol bindings. If a protocol of MyServer::MyTCP was passed, the socket would be blessed into that class. If Net::Server::Proto::TCP was passed, it would get that class. If a bareword, such as tcp, udp, unix, unixdgram or ssleay, is passed, the word is uppercased, and post pended to "Net::Server::Proto::" (ie tcp = Net::Server::Proto::TCP).

METHODS
Protocol names used by the Net::Server::Proto should be sub classes of IO::Socket. These classes should also contain, as a minimum, the following methods should be provided:

object
    Return an object which is a sub class of IO::Socket At this point the object is not connected. The method can gather any other information that it needs from the server object. Arguments are default_host, port, and a Net::Server style server object.

log_connect
    Log that a connection is about to occur. Use the facilities of the passed Net::Server object. This should be an informative string explaining which properties are being used.

connect
    Actually bind to port or socket file. This is typically done internally by calling the configure method of the IO::Socket super class.

reconnect
    Allow for rebinding to an already open fileno. Typically will just do an fdopen using the IO::Socket super class.

hup_string
    Return a unique identifying string for this sock that can be used when reconnecting. This is done to allow information including the file descriptor of the open sockets to be passed via %ENV during an exec. This string should always be the same based upon the configuration parameters.

NS_port
    Net::Server protocol. Return the port that is being used by this module. If the underlying type is UNIX then port will actually be the path to the unix socket file.

NS_host
    Net::Server protocol. Return the protocol that is being used by this module. This does not have to be a registered or known protocol.

NS_proto
    Net::Server protocol. Return the protocol that is being used by this module. This does not have to be a registered or known protocol.

show
    Similar to log_connect, but simply shows a listing of which properties were found. Can be used at any time.

HOST
The hostname may be either blank, '*', be an IPv4 address, an IPv6 address, a bare hostname, or a hostname with IPv* specifications.

    host => "127.0.0.1",  # an IPv4 address

    host => "::1",        # an IPv6 address

    host => 'localhost',  # addresses returned by localhost (default IPv* - IPv4 and/or IPv6)

    host => 'localhost/IPv*',  # same

    ipv  => '*',
    host => 'localhost',  # same

    ipv  => 6,
    host => 'localhost',  # addresses returned by localhost (IPv6)

    ipv  => 'IPv4 IPv6',
    host => 'localhost',  # addresses returned by localhost (requires IPv6 and IPv4)

    host => '*',          # any local interfaces (default IPv*)

    ipv  => '*',
    host => '*',          # any local interfaces (any IPv6 or IPv4)

    host => '*/IPv*',     # same

IPV
In addition to being able to specify IPV as a separate parameter, ipv may also be passed as a part of the host, as part of the port, as part of the protocol or may be specified via $ENV{'IPV'}. The order of precidence is as follows:

     1) Explicit IPv4 or IPv6 address - wins
     2) ipv specified in port
     3) ipv specified in host
     4) ipv specified in proto
     5) ipv specified in default settings
     6) ipv specified in $ENV{'IPV'}
     7) default to IPv*

PORT
The port is the most important argument passed to the sub module classes and to Net::Server::Proto itself. For tcp, udp, and ssleay style ports, the form is generally host:port/protocol, [host]:port/protocol, host|port|protocol, host/port, or port. If host is a numerical IPv6 address it should be enclosed in square brackets to avoid ambiguity in parsing a port number, e.g.: "[::1]:80". Separating with spaces, commas, or pipes is also allowed, e.g. "::1, 80". For unix sockets the form is generally socket_file|unix or socket_file.

To help overcome parsing ambiguity, it is also possible to pass port as a hashref (or as an array of hashrefs) of information such as:

    port => {
        host  => "localhost",
        ipv   => 6, # could also pass IPv6 (* is default)
        port  => 20203,
        proto => 'tcp',
    }

If a hashref does not include host, ipv, or proto - it will use the default value supplied by the general configuration.

A socket protocol family PF_INET or PF_INET6 is derived from a specified address family of the binding address. A PF_INET socket can only accept IPv4 connections. A PF_INET6 socket accepts IPv6 connections, but may also accept IPv4 connections, depending on OS and its settings. For example, on FreeBSD systems setting a sysctl net.inet6.ip6.v6only to 0 will allow IPv4 connections to a PF_INET6 socket. By default on linux, binding to host [::] will accept IPv4 or IPv6 connections.

The Net::Server::Proto::object method returns a list of objects corresponding to created sockets. For Unix and INET sockets the list typically contains just one element, but may return multiple objects when multiple protocol families are allowed or when a host name resolves to multiple local binding addresses. This is particularly true when an ipv value of '*' is passed in allowing hostname resolution.

You can see what Net::Server::Proto parsed out by looking at the logs to see what log_connect said. You could also include a post_bind_hook similar to the following to debug what happened:

    sub post_bind_hook {
        my $self = shift;
        foreach my $sock ( @{ $self->{server}->{sock} } ){
            $self->log(2,$sock->show);
        }
    }

Rather than try to explain further, please look at the following examples:

    # example 1 #----------------------------------

    $port      = "20203";
    $def_host  = "default-domain.com";
    $def_proto = undef;
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => 'default-domain.com',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => *, # IPv*
    # };

    # example 2 #----------------------------------

    $port      = "someother.com:20203";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => *,
    # };

    # example 3 #----------------------------------

    $port      = "someother.com:20203/udp";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'udp', # will use Net::Server::Proto::UDP
    #     ipv   => *,
    # };

    # example 4 #----------------------------------

    $port      = "someother.com:20203/Net::Server::Proto::UDP";
    $def_host  = "default-domain.com";
    $def_proto = "TCP";
    $def_ipv   = 4;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'Net::Server::Proto::UDP',
    #     ipv   => 4,
    # };

    # example 5 #----------------------------------

    $port      = "someother.com:20203/MyObject::TCP";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto);
    # @info = {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'MyObject::TCP',
    # };

    # example 6 #----------------------------------

    $port      = "/tmp/mysock.file|unix";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '*', # irrelevant for UNIX socket
    #     port  => '/tmp/mysock.file', # not really a port
    #     proto => 'unix', # will use Net::Server::Proto::UNIX
    #     ipv   => '*', # irrelevant for UNIX socket
    # };

    # example 7 #----------------------------------

    $port      = "/tmp/mysock.file|unixdgram";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '*', # irrelevant for UNIX socket
    #     port  => '/tmp/mysock.file', # not really a port
    #     proto => 'unixdgram', # will use Net::Server::Proto::UNIXDGRAM
    #     ipv   => '*', # irrelevant for UNIX socket
    # };

    # example 8 #----------------------------------

    $port      = "/tmp/mysock.file|SOCK_STREAM|unix"; # legacy
    $def_host  = "";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '*', # irrelevant for UNIX socket
    #     port  => '/tmp/mysock.file', # not really a port
    #     proto => 'unix', # will use Net::Server::Proto::UNIX
    #     unix_type => 'SOCK_STREAM',
    #     ipv   => '*', # irrelevant for UNIX socket
    # };

    # example 9 #----------------------------------

    $port      = "/tmp/mysock.file|SOCK_DGRAM|unix"; # legacy
    $def_host  = "";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '*', # irrelevant for UNIX socket
    #     port  => '/tmp/mysock.file', # not really a port
    #     proto => 'unix', # will use Net::Server::Proto::UNIXDGRAM
    #     unix_type => 'SOCK_DGRAM',
    #     ipv   => '*', # irrelevant for UNIX socket
    # };

    # example 10 #----------------------------------

    $port = "someother.com:20203/ssleay";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'ssleay', # will use Net::Server::Proto::SSLEAY
    #     ipv   => *,
    # };

    # example 11 #----------------------------------

    $port = "[::1]:20203 ipv6 tcp";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '::1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 6,
    # };

    # example 12 #----------------------------------

    $port = "[::1]:20203 tcp";
    $def_host  = "default-domain.com/IPv6";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = {
    #     host  => '::1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 6,
    # };

    # example 13 #----------------------------------

    $port = "[someother.com]:20203 ipv6 ipv4 tcp";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = ({
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 4,
    # }, {
    #     host  => 'someother.com',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 6,
    # });

    # example 14 #----------------------------------

    # depending upon your configuration
    $port = "localhost:20203";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = ({
    #     host  => '127.0.0.1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 4, # IPv4
    # }, {
    #     host  => '::1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 6, # IPv6
    # });

    # example 15 #----------------------------------

    # depending upon your configuration
    $port = "localhost:20203";
    $def_host  = "default-domain.com IPv*";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = ({
    #     host  => '127.0.0.1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 4, # IPv4
    # }, {
    #     host  => '::1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 6, # IPv6
    # });

    # example 16 #----------------------------------

    # depending upon your configuration
    $ENV{'IPV'} = '4';
    $port = "localhost:20203";
    $def_host  = "default-domain.com";
    $def_proto = "tcp";
    $def_ipv   = undef;
    @info = Net::Server::Proto->parse_info($port,$def_host,$def_proto,$def_ipv);
    # @info = ({
    #     host  => '127.0.0.1',
    #     port  => 20203,
    #     proto => 'tcp', # will use Net::Server::Proto::TCP
    #     ipv   => 4, # IPv4
    # });

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