rhandom / perl-net-server

Perl Module Net::Server
Other
14 stars 29 forks source link

NAME Net::Server - Extensible, general Perl server engine

SYNOPSIS

!/usr/bin/perl -w -T

    package MyPackage;

    use base qw(Net::Server);

    sub process_request {
        my $self = shift;
        while (<STDIN>) {
            s/[\r\n]+$//;
            print "You said '$_'\015\012"; # basic echo
            last if /quit/i;
        }
    }

    MyPackage->run(port => 160, ipv => '*');

    # one liner to get going quickly
    perl -e 'use base qw(Net::Server); main->run(port => 20208)'

    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, any available IPv4 and IPv6 sockets 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.

FEATURES

DESCRIPTION "Net::Server" is an extensible, generic Perl server engine.

"Net::Server" attempts to be a generic server as in "Net::Daemon" and
"NetServer::Generic". It includes with it the ability to run as an inetd
process ("Net::Server::INET"), a single connection server ("Net::Server"
or "Net::Server::Single"), a forking server ("Net::Server::Fork"), a
preforking server which maintains a constant number of preforked
children ("Net::Server::PreForkSimple"), or as a managed preforking
server which maintains the number of children based on server load
("Net::Server::PreFork"). In all but the inetd type, the server provides
the ability to connect to one or to multiple server ports.

The additional server types are made possible via "personalities" or sub
classes of the "Net::Server". By moving the multiple types of servers
out of the main "Net::Server" class, the "Net::Server" concept is easily
extended to other types (in the near future, we would like to add a
"Thread" personality).

"Net::Server" borrows several concepts from the Apache Webserver.
"Net::Server" uses "hooks" to allow custom servers such as SMTP, HTTP,
POP3, etc. to be layered over the base "Net::Server" class. In addition
the "Net::Server::PreFork" class borrows concepts of min_start_servers,
max_servers, and min_waiting servers. "Net::Server::PreFork" also uses
the concept of an flock serialized accept when accepting on multiple
ports (PreFork can choose between flock, IPC::Semaphore, and pipe to
control serialization).

PERSONALITIES "Net::Server" is built around a common class (Net::Server) and is extended using sub classes, or "personalities". Each personality inherits, overrides, or enhances the base methods of the base class.

Included with the Net::Server package are several basic personalities,
each of which has their own use.

Fork
    Found in the module Net/Server/Fork.pm (see Net::Server::Fork). This
    server binds to one or more ports and then waits for a connection.
    When a client request is received, the parent forks a child, which
    then handles the client and exits. This is good for moderately hit
    services.

INET
    Found in the module Net/Server/INET.pm (see Net::Server::INET). This
    server is designed to be used with inetd. The "pre_bind", "bind",
    "accept", and "post_accept" are all overridden as these services are
    taken care of by the INET daemon.

MultiType
    Found in the module Net/Server/MultiType.pm (see
    Net::Server::MultiType). This server has no server functionality of
    its own. It is designed for servers which need a simple way to
    easily switch between different personalities. Multiple
    "server_type" parameters may be given and Net::Server::MultiType
    will cycle through until it finds a class that it can use.

Multiplex
    Found in the module Net/Server/Multiplex.pm (see
    Net::Server::Multiplex). This server binds to one or more ports. It
    uses IO::Multiplex to multiplex between waiting for new connections
    and waiting for input on currently established connections. This
    personality is designed to run as one process without forking. The
    "process_request" method is never used but the "mux_input" callback
    is used instead (see also IO::Multiplex). See examples/samplechat.pl
    for an example using most of the features of Net::Server::Multiplex.

PreForkSimple
    Found in the module Net/Server/PreFork.pm (see
    Net::Server::PreFork). This server binds to one or more ports and
    then forks "max_servers" child process. The server will make sure
    that at any given time there are always "max_servers" available to
    receive a client request. Each of these children will process up to
    "max_requests" client connections. This type is good for a heavily
    hit site that can dedicate max_server processes no matter what the
    load. It should scale well for most applications. Multi port accept
    is accomplished using either flock, IPC::Semaphore, or pipe to
    serialize the children. Serialization may also be switched on for
    single port in order to get around an OS that does not allow
    multiple children to accept at the same time. For a further
    discussion of serialization see Net::Server::PreFork.

PreFork
    Found in the module Net/Server/PreFork.pm (see
    Net::Server::PreFork). This server binds to one or more ports and
    then forks "min_servers" child process. The server will make sure
    that at any given time there are at least "min_spare_servers" but
    not more than "max_spare_servers" available to receive a client
    request, up to "max_servers". Each of these children will process up
    to "max_requests" client connections. This type is good for a
    heavily hit site, and should scale well for most applications. Multi
    port accept is accomplished using either flock, IPC::Semaphore, or
    pipe to serialize the children. Serialization may also be switched
    on for single port in order to get around an OS that does not allow
    multiple children to accept at the same time. For a further
    discussion of serialization see Net::Server::PreFork.

Single
    All methods fall back to Net::Server. This personality is provided
    only as parallelism for Net::Server::MultiType.

HTTP
    Not a distinct personality. Provides a basic HTTP daemon. This can
    be combined with the SSL or SSLEAY proto to provide an HTTPS Daemon.
    See Net::Server::HTTP.

"Net::Server" was partially written to make it easy to add new
personalities. Using separate modules built upon an open architecture
allows for easy addition of new features, a separate development
process, and reduced code bloat in the core module.

SOCKET ACCESS Once started, the Net::Server will take care of binding to port and waiting for connections. Once a connection is received, the Net::Server will accept on the socket and will store the result (the client connection) in $self->{server}->{client}. This property is a Socket blessed into the the IO::Socket classes. UDP servers are slightly different in that they will perform a recv instead of an accept.

To make programming easier, during the post_accept phase, STDIN and
STDOUT are opened to the client connection. This allows for programs to
be written using <STDIN> and print "out\n" to print to the client
connection. UDP will require using a ->send call.

SAMPLE CODE The following is a very simple server. The main functionality occurs in the process_request method call as shown below. Notice the use of timeouts to prevent Denial of Service while reading. (Other examples of using "Net::Server" can, or will, be included with this distribution).

    #!/usr/bin/perl -w -T

    package MyPackage;

    use strict;
    use base qw(Net::Server::PreFork); # any personality will do

    MyPackage->run;

    # over-ride the default echo handler

    sub process_request {
        my $self = shift;
        eval {

            local $SIG{'ALRM'} = sub { die "Timed Out!\n" };
            my $timeout = 30; # give the user 30 seconds to type some lines

            my $previous_alarm = alarm($timeout);
            while (<STDIN>) {
                s/\r?\n$//;
                print "You said '$_'\r\n";
                alarm($timeout);
            }
            alarm($previous_alarm);

        };

        if ($@ =~ /timed out/i) {
            print STDOUT "Timed Out.\r\n";
            return;
        }

    }

    1;

Playing this file from the command line will invoke a Net::Server using
the PreFork personality. When building a server layer over the
Net::Server, it is important to use features such as timeouts to prevent
Denial Of Service attacks.

Net::Server comes with a built in echo server by default. You can test
it out by simply running the following from the commandline:

    net-server

If you wanted to try another flavor you could try

    net-server PreFork

If you wanted to try out a basic HTTP server you could use

    net-server HTTP

Or if you wanted to test out a CGI you are writing you could use

    net-server HTTP --app ../../mycgi.cgi

ARGUMENTS There are at least five possible ways to pass arguments to Net::Server. They are passing to the new method, passing on command line, passing parameters to run, using a conf file, returning values in the default_values method, or configuring the values in post_configure_hook.

The "options" method is used to determine which arguments the server
will search for and can be used to extend the parsed parameters. Any
arguments found from the command line, parameters passed to run, and
arguments found in the conf_file will be matched against the keys of the
options template. Any commandline parameters that do not match will be
left in place and can be further processed by the server in the various
hooks (by looking at @ARGV). Arguments passed to new will automatically
win over any other options (this can be used if you would like to
disallow a user passing in other arguments).

Arguments consist of key value pairs. On the commandline these pairs
follow the POSIX fashion of "--key value" or "--key=value", and also
"key=value". In the conf file the parameter passing can best be shown by
the following regular expression: ($key,$val)=~/^(\w+)\s+(\S+?)\s+$/.
Passing arguments to the run method is done as follows:
"<Net::Server->run(key1 =" 'val1')>>. Passing arguments via a prebuilt
object can best be shown in the following code:

    #!/usr/bin/perl -w -T

    package MyPackage;
    use strict;
    use base qw(Net::Server);

    my $server = MyPackage->new({
        key1 => 'val1',
    });

    $server->run;

All five methods for passing arguments may be used at the same time.
Once an argument has been set, it is not over written if another method
passes the same argument. "Net::Server" will look for arguments in the
following order:

    1) Arguments passed to the C<new> method.
    2) Arguments passed on command line.
    3) Arguments passed to the C<run> method.
    4) Arguments passed via a conf file.
    5) Arguments set in the C<default_values> method.

Additionally the following hooks are available:

    1) Arguments set in the configure_hook (occurs after new
       but before any of the other areas are checked).
    2) Arguments set and validated in the post_configure_hook
       (occurs after all of the other areas are checked).

Each of these levels will override parameters of the same name specified
in subsequent levels. For example, specifying --setsid=0 on the command
line will override a value of "setsid 1" in the conf file.

Note that the configure_hook method doesn't return values to set, but is
there to allow for setting up configured values before the configure
method is called.

Key/value pairs used by the server are removed by the configuration
process so that server layers on top of "Net::Server" can pass and read
their own parameters.

ADDING CUSTOM ARGUMENTS It is possible to add in your own custom parameters to those parsed by Net::Server. The following code shows how this is done:

    sub options {
        my $self     = shift;
        my $prop     = $self->{'server'};
        my $template = shift;

        # setup options in the parent classes
        $self->SUPER::options($template);

        # add a single value option
        $prop->{'my_option'} ||= undef;
        $template->{'my_option'} = \ $prop->{'my_option'};

        # add a multi value option
        $prop->{'an_arrayref_item'} ||= [];
        $template->{'an_arrayref_item'} = $prop->{'an_arrayref_item'};
    }

Overriding the "options" method allows for adding your own custom
fields. A template hashref is passed in, that should then be modified to
contain an of your custom fields. Fields which are intended to receive a
single scalar value should have a reference to the destination scalar
given. Fields which are intended to receive multiple values should
reference the corresponding destination arrayref.

You are responsible for validating your custom options once they have
been parsed. The post_configure_hook is a good place to do your
validation.

Some emails have asked why we use this "template" method. The idea is
that you are creating the the data structure to store the values in, and
you are also creating a way to get the values into the data structure.
The template is the way to get the values to the servers data structure.
One of the possibilities (that probably isn't used that much) is that by
letting you specify the mapping, you could build a nested data structure
- even though the passed in arguments are flat. It also allows you to
setup aliases to your names.

For example, a basic structure might look like this:

   $prop = $self->{'server'}

   $prop->{'my_custom_option'} ||= undef;
   $prop->{'my_custom_array'}  ||= [];

   $template = {
       my_custom_option => \ $prop->{'my_custom_option'},
       mco              => \ $prop->{'my_custom_option'}, # alias
       my_custom_array  => $prop->{'my_custom_array'},
       mca              => $prop->{'my_custom_array'}, # an alias
   };

   $template->{'mco2'} = $template->{'mco'}; # another way to alias

But you could also have more complex data:

   $prop = $self->{'server'};

   $prop->{'one_layer'} = {
       two_layer => [
           undef,
           undef,
       ],
   };

   $template = {
       param1 => \ $prop->{'one_layer'}->{'two_layer'}->[0],
       param2 => \ $prop->{'one_layer'}->{'two_layer'}->[1],
   };

This is of course a contrived example - but it does show that you can
get the data from the flat passed in arguments to whatever type of
structure you need - with only a little bit of effort.

DEFAULT ARGUMENTS FOR Net::Server The following arguments are available in the default "Net::Server" or "Net::Server::Single" modules. (Other personalities may use additional parameters and may optionally not use parameters from the base class.)

    Key               Value                    Default
    conf_file         "filename"               undef

    log_level         0-4                      2
    log_file          (filename|Sys::Syslog
                       |Log::Log4perl)         undef

    port              \d+                      20203
    host              "host"                   "*"
    ipv               (4|6|*)                  *
    proto             (tcp|udp|unix)           "tcp"
    listen            \d+                      SOMAXCONN

    ## syslog parameters (if log_file eq Sys::Syslog)
    syslog_logsock    (native|unix|inet|udp
                       |tcp|stream|console)    unix (on Sys::Syslog < 0.15)
    syslog_ident      "identity"               "net_server"
    syslog_logopt     (cons|ndelay|nowait|pid) pid
    syslog_facility   \w+                      daemon

    reverse_lookups   1                        undef
    allow             /regex/                  none
    deny              /regex/                  none
    cidr_allow        CIDR                     none
    cidr_deny         CIDR                     none

    ## daemonization parameters
    pid_file          "filename"               undef
    chroot            "directory"              undef
    user              (uid|username)           "nobody"
    group             (gid|group)              "nobody"
    background        1                        undef
    setsid            1                        undef

    no_close_by_child (1|undef)                undef

    ## See Net::Server::Proto::(TCP|UDP|UNIX|SSL|SSLeay|etc)
    ## for more sample parameters.

conf_file
    Filename from which to read additional key value pair arguments for
    starting the server. Default is undef.

    There are two ways that you can specify a default location for a
    conf_file. The first is to pass the default value to the run method
    as in:

        MyServer->run({
           conf_file => '/etc/my_server.conf',
        });

    If the end user passes in --conf_file=/etc/their_server.conf then
    the value will be overridden.

    The second way to do this was added in the 0.96 version. It uses the
    default_values method as in:

        sub default_values {
            return {
                conf_file => '/etc/my_server.conf',
            }
        }

    This method has the advantage of also being able to be overridden in
    the run method.

    If you do not want the user to be able to specify a conf_file at
    all, you can pass conf_file to the new method when creating your
    object:

        MyServer->new({
           conf_file => '/etc/my_server.conf',
        })->run;

    If passed this way, the value passed to new will "win" over any of
    the other passed in values.

log_level
    Ranges from 0 to 4 in level. Specifies what level of error will be
    logged. "O" means logging is off. "4" means very verbose. These
    levels should be able to correlate to syslog levels. Default is 2.
    These levels correlate to syslog levels as defined by the following
    key/value pairs: 0=>'err', 1=>'warning', 2=>'notice', 3=>'info',
    4=>'debug'.

log_file
    Name of log file or log subsystem to be written to. If no name is
    given and the write_to_log_hook is not overridden, log goes to
    STDERR. Default is undef.

    The log_file may also be the name of a Net::Server pluggable logging
    class. Net::Server is packaged with Sys::Syslog and Log::Log4perl.
    If the log_file looks like a module name, it will have
    "Net::Server::Log::" added to the front and it will then be
    required. The package should provide an "initialize" class method
    that returns a single function which will be used for logging. This
    returned function will be passed log_level, and message.

    If the magic name "Sys::Syslog" is used, all logging will take place
    via the Net::Server::Log::Sys::Syslog module. If syslog is used the
    parameters "syslog_logsock", "syslog_ident", and "syslog_logopt",and
    "syslog_facility" may also be defined. See
    Net::Server::Log::Sys::Syslog.

    If the magic name "Log::Log4perl" is used, all logging will be
    directed to the Log4perl system. If used, the "log4perl_conf",
    "log4perl_poll", "log4perl_logger" may also be defined. See
    Net::Server::Log::Log::Log4per.

    If a "log_file" is given or if "setsid" is set, STDIN and STDOUT
    will automatically be opened to /dev/null and STDERR will be opened
    to STDOUT. This will prevent any output from ending up at the
    terminal.

pid_file
    Filename to store pid of parent process. Generally applies only to
    forking servers. Default is none (undef).

port
    See Net::Server::Proto for further examples of configuration.

    Local port/socket on which to bind. If it is a low port, the process
    must start as root. If multiple ports are given, all will be bound
    at server startup. May be of the form "host:port/proto",
    "host:port/proto/ipv", "host:port", "port/proto", or "port", where
    *host* represents a hostname residing on the local box, where *port*
    represents either the number of the port (eg. "80") or the service
    designation (eg. "http"), where *ipv* represents the IP protocol
    version (IPv4 or IPv6 or IPv*) and where *proto* represents the
    protocol to be used. See Net::Server::Proto. The following are some
    valid port strings:

        20203                            # port only
        localhost:20203                  # host and port
        localhost:http                   # localhost bound to port 80
        localhost:20203/tcp              # host, port, protocol
        localhost:20203/tcp/IPv*         # host, port, protocol and family
        localhost, 20203, tcp, IPv*      # same
        localhost | 20203 | tcp | IPv*   # same
        localhost:20203/IPv*             # bind any configured interfaces for IPv4 or 6 (default)
        localhost:20203/IPv4/IPv6        # bind localhost on IPv4 and 6 (fails if it cannot do both)

        *:20203                          # bind all local interfaces

    Additionally, when passed in the code (non-commandline, and
    non-config), the port may be passed as a hashref or array hashrefs
    of information:

        port => {
            host  => 'localhost',
            port  => '20203',
            ipv   => 6,     # IPv6 only
            proto => 'udp', # UDP protocol
        }

        port => [{
            host  => '*',
            port  => '20203',
            ipv   => 4,     # IPv4 only
            proto => 'tcp', # (default)
        }, {
            host  => 'localhost',
            port  => '20204',
            ipv   => '*',      # default - all IPv4 and IPv6 interfaces tied to localhost
            proto => 'ssleay', # or ssl - Using SSL
        }],

    An explicit *host* given in a port specification overrides a default
    binding address (a "host" setting, see below). The *host* part may
    be enclosed in square brackets, but when it is a numerical IPv6
    address it should be enclosed in square brackets to avoid ambiguity
    in parsing a port number, e.g.: "[::1]:80". However you could also
    use pipes, white space, or commas to separate these. Note that host
    and port number must come first.

    If the protocol is not specified, *proto* will default to the
    "proto" specified in the arguments. If "proto" is not specified
    there it will default to "tcp". If *host* is not specified, *host*
    will default to "host" specified in the arguments. If "host" is not
    specified there it will default to "*". Default port is 20203.
    Configuration passed to new or run may be either a scalar containing
    a single port number or an arrayref of ports. If "ipv" is not
    specified it will default to "*" (Any resolved addresses under IPv4
    or IPv6).

    If you are working with unix sockets, you may also specify
    "socket_file|unix" or "socket_file|type|unix" where type is
    SOCK_DGRAM or SOCK_STREAM.

    On systems that support it, a port value of 0 may be used to ask the
    OS to auto-assign a port. The value of the auto-assigned port will
    be stored in the NS_port property of the Net::Server::Proto::TCP
    object and is also available in the sockport method. When the server
    is processing a request, the $self->{server}->{sockport} property
    contains the port that was connected through.

host
    Local host or addr upon which to bind port. If a value of '*' is
    given, the server will bind that port on all available addresses on
    the box. The "host" argument provides a default local host address
    if the "port" argument omits a host specification. See
    Net::Server::Proto. See IO::Socket. Configuration passed to new or
    run may be either a scalar containing a single host or an arrayref
    of hosts - if the hosts array is shorter than the ports array, the
    last host entry will be used to augment the hosts arrary to the size
    of the ports array.

    If an IPv4 address is passed, an IPv4 socket will be created. If an
    IPv6 address is passed, an IPv6 socket will be created. If a
    hostname is given, Net::Server will look at the value of ipv
    (default IPv4) to determine which type of socket to create.
    Optionally the ipv specification can be passed as part of the
    hostname.

        host => "127.0.0.1",  # an IPv4 address

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

        host => 'localhost',  # addresses matched by localhost (default any IPv4 and/or IPv6)

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

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

        ipv  => 4,
        host => 'localhost',  # addresses matched by localhost (IPv4)

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

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

        host => '*/IPv*',     # same (any IPv6 or IPv4)

        ipv  => 4,
        host => '*',          # any local IPv4 interfaces interfaces

proto
    See Net::Server::Proto. Protocol to use when binding ports. See
    IO::Socket. As of release 2.0, Net::Server supports tcp, udp, and
    unix, unixdgram, ssl, and ssleay. Other types will need to be added
    later (or custom modules extending the Net::Server::Proto class may
    be used). Configuration passed to new or run may be either a scalar
    containing a single proto or an arrayref of protos - if the protos
    array is shorter than the ports array, the last proto entry will be
    used to augment the protos arrary to the size of the ports array.

    Additionally the proto may also contain the ipv specification.

ipv (IPv4 and IPv6)
    See Net::Server::Proto.

    IPv6 is now available under Net::Server. It will be used
    automatically if an IPv6 address is passed, or if the ipv is set
    explicitly to IPv6, or if ipv is left as the default value of IPv*.
    This is a significant change from version 2.004 and earlier where
    the default value was IPv4. However, the previous behavior led to
    confusion on IPv6 only hosts, and on hosts that only had IPv6
    entries for a local hostname. Trying to pass an IPv4 address when
    ipv is set to 6 (only 6 - not * or 4) will result in an error.

        localhost:20203 # will use IPv6 if there is a corresponding entry for localhost
                        # it will also use IPv4 if there is a corresponding v4 entry for localhost

        localhost:20203:IPv*  # same (default)

        localhost:20203:IPv6  # will use IPv6

        [::1]:20203           # will use IPv6 (IPv6 style address)

        localhost:20203:IPv4  # will use IPv4

        127.0.0.1:20203       # will use IPv4 (IPv4 style address

        localhost:20203:IPv4:IPv6 # will bind to both v4 and v6 - fails otherwise

        # or as a hashref as
        port => {
            host => "localhost",
            ipv  => 6, # only binds IPv6
        }

        port => {
            host => "localhost",
            ipv  => 4, # only binds IPv4
        }

        port => {
            host => "::1",
            ipv  => "IPv6", # same as passing "6"
        }

        port => {
            host => "localhost/IPv*",       # any IPv4 or IPv6
        }

        port => {
            host => "localhost IPv4 IPv6",  # must create both
        }

    In many proposed Net::Server solutions, IPv* was enabled by default.
    For versions 2.000 through 2.004, the previous default of IPv4 was
    used. We have attempted to make it easy to set IPv4, IPv6, or IPv*.
    If you do not want or need IPv6, simply set ipv to 4, pass IPv4
    along in the port specification, set $ENV{'IPV'}=4; before running
    the server, or uninstall IO::Socket::INET6.

    On my local box the following command results in the following
    output:

        perl -e 'use base qw(Net::Server); main->run(host => "localhost")'

        Resolved [localhost]:20203 to [::1]:20203, IPv6
        Resolved [localhost]:20203 to [127.0.0.1]:20203, IPv4
        Binding to TCP port 20203 on host ::1 with IPv6
        Binding to TCP port 20203 on host 127.0.0.1 with IPv4

    My local box has IPv6 enabled and there are entries for localhost on
    both IPv6 ::1 and IPv4 127.0.0.1. I could also choose to explicitly
    bind ports rather than depending upon ipv => "*" to resolve them for
    me as in the following:

        perl -e 'use base qw(Net::Server); main->run(port => [20203,20203], host => "localhost", ipv => [4,6])'

        Binding to TCP port 20203 on host localhost with IPv4
        Binding to TCP port 20203 on host localhost with IPv6

    There is a special case of using host => "*" as well as ipv => "*".
    The Net::Server::Proto::_bindv6only method is used to check the
    system setting for "sysctl -n net.ipv6.bindv6only" (or
    net.inet6.ip6.v6only). If this setting is false, then an IPv6 socket
    will listen for the corresponding IPv4 address. For example the
    address [::] (IPv6 equivalent of INADDR_ANY) will also listen for
    0.0.0.0. The address ::FFFF:127.0.0.1 (IPv6) would also listen to
    127.0.0.1 (IPv4). In this case, only one socket will be created
    because it will handle both cases (an error is returned if an
    attempt is made to listen to both addresses when bindv6only is
    false).

    However, if net.ipv6.bindv6only (or equivalent) is true, then a
    hostname (such as *) resolving to both a IPv4 entry as well as an
    IPv6 will result in both an IPv4 socket as well as an IPv6 socket.

    On my linux box which defaults to net.ipv6.bindv6only=0, the
    following is output.

        perl -e 'use base qw(Net::Server); main->run(host => "*")'

        Resolved [*]:8080 to [::]:8080, IPv6
        Not including resolved host [0.0.0.0] IPv4 because it will be handled by [::] IPv6
        Binding to TCP port 8080 on host :: with IPv6

    If I issue a "sudo /sbin/sysctl -w net.ipv6.bindv6only=1", the
    following is output.

        perl -e 'use base qw(Net::Server); main->run(host => "*")'

        Resolved [*]:8080 to [0.0.0.0]:8080, IPv4
        Resolved [*]:8080 to [::]:8080, IPv6
        Binding to TCP port 8080 on host 0.0.0.0 with IPv4
        Binding to TCP port 8080 on host :: with IPv6

    BSD differs from linux and generally defaults to
    net.inet6.ip6.v6only=0. If it cannot be determined on your OS, it
    will default to false and the log message will change from "it will
    be handled" to "it should be handled" (if you have a non-resource
    intensive way to check on your platform, feel free to email me). Be
    sure to check the logs as you test your server to make sure you have
    bound the ports you desire. You can always pass in individual
    explicit IPv4 and IPv6 port specifications if you need. For example,
    if your system has both IPv4 and IPv6 interfaces but you'd only like
    to bind to IPv6 entries, then you should use a hostname of [::]
    instead of [*].

    If bindv6only (or equivalent) is false, and you receive an IPv4
    connection on a bound IPv6 port, the textual representation of the
    peer's IPv4 address will typically be in a form of an IPv4-mapped
    IPv6 addresses, e.g. "::FFFF:127.0.0.1" .

    The ipv parameter was chosen because it does not conflict with any
    other existing usage, it is very similar to ipv4 or ipv6, it allows
    for user code to not need to know about Socket::AF_INET or
    Socket6::AF_INET6 or Socket::AF_UNSPEC, and it is short.

listen
    See IO::Socket. Not used with udp protocol (or UNIX SOCK_DGRAM).

reverse_lookups
    Specify whether to lookup the hostname of the connected IP.
    Information is cached in server object under "peerhost" property.
    Default is to not use reverse_lookups (undef).

allow/deny
    May be specified multiple times. Contains regex to compare to
    incoming peeraddr or peerhost (if reverse_lookups has been enabled).
    If allow or deny options are given, the incoming client must match
    an allow and not match a deny or the client connection will be
    closed. Defaults to empty array refs.

cidr_allow/cidr_deny
    May be specified multiple times. Contains a CIDR block to compare to
    incoming peeraddr. If cidr_allow or cidr_deny options are given, the
    incoming client must match a cidr_allow and not match a cidr_deny or
    the client connection will be closed. Defaults to empty array refs.

chroot
    Directory to chroot to after bind process has taken place and the
    server is still running as root. Defaults to undef.

user
    Userid or username to become after the bind process has occurred.
    Defaults to "nobody." If you would like the server to run as root,
    you will have to specify "user" equal to "root".

group
    Groupid or groupname to become after the bind process has occurred.
    Defaults to "nobody." If you would like the server to run as root,
    you will have to specify "group" equal to "root".

background
    Specifies whether or not the server should fork after the bind
    method to release itself from the command line. Defaults to undef.
    Process will also background if "setsid" is set.

setsid
    Specifies whether or not the server should fork after the bind
    method to release itself from the command line and then run the
    "POSIX::setsid()" command to truly daemonize. Defaults to undef. If
    a "log_file" is given or if "setsid" is set, STDIN and STDOUT will
    automatically be opened to /dev/null and STDERR will be opened to
    STDOUT. This will prevent any output from ending up at the terminal.

no_close_by_child
    Boolean. Specifies whether or not a forked child process has
    permission or not to shutdown the entire server process. If set to
    1, the child may NOT signal the parent to shutdown all children.
    Default is undef (not set).

no_client_stdout
    Boolean. Default undef (not set). Specifies that STDIN and STDOUT
    should not be opened on the client handle once a connection has been
    accepted. By default the Net::Server will open STDIN and STDOUT on
    the client socket making it easier for many types of scripts to read
    directly from and write directly to the socket using normal print
    and read methods. Disabling this is useful on clients that may be
    opening their own connections to STDIN and STDOUT.

    This option has no affect on STDIN and STDOUT which has a magic
    client property that is tied to the already open STDIN and STDOUT.

leave_children_open_on_hup
    Boolean. Default undef (not set). If set, the parent will not
    attempt to close child processes if the parent receives a SIG HUP.
    The parent will rebind the the open port and begin tracking a fresh
    set of children.

    Children of a Fork server will exit after their current request.
    Children of a Prefork type server will finish the current request
    and then exit.

    Note - the newly restarted parent will start up a fresh set of
    servers on fork servers. The new parent will attempt to keep track
    of the children from the former parent but custom communication
    channels (open pipes from the child to the old parent) will no
    longer be available to the old child processes. New child processes
    will still connect properly to the new parent.

sig_passthrough
    Default none. Allow for passing requested signals through to
    children. Takes a single signal name, a comma separated list of
    names, or an arrayref of signal names. It first sends the signals to
    the children before calling any currently registered signal by that
    name.

tie_client_stdout
    Default undef. If set will use Net::Server::TiedHandle tied
    interface for STDIN and STDOUT. This interface allows SSL and SSLEAY
    to work. It also allows for intercepting read and write via the
    tied_stdin_callback and tied_stdout_callback.

tied_stdin_callback
    Default undef. Called during a read of STDIN data if
    tie_client_stdout has been set, or if the client handle's tie_stdout
    method returns true. It is passed the client connection, the name of
    the method that would be called, and the arguments that are being
    passed. The callback is then responsible for calling that method on
    the handle or for performing some other input operation.

tied_stdout_callback
    Default undef. Called during a write of data to STDOUT if
    tie_client_stdout has been set, or if the client handle's tie_stdout
    method returns true. It is passed the client connection, the name of
    the method that would be called, and the arguments that are being
    passed. The callback is then responsible for calling that method on
    the handle or for performing some other output operation.

PROPERTIES All of the "ARGUMENTS" listed above become properties of the server object under the same name. These properties, as well as other internal properties, are available during hooks and other method calls.

The structure of a Net::Server object is shown below:

    $self = bless({
        server => {
            key1 => 'val1',
            # more key/vals
        },
    }, 'Net::Server');

This structure was chosen so that all server related properties are
grouped under a single key of the object hashref. This is so that other
objects could layer on top of the Net::Server object class and still
have a fairly clean namespace in the hashref.

You may get and set properties in two ways. The suggested way is to
access properties directly via

    my $val = $self->{server}->{key1};

Accessing the properties directly will speed the server process - though
some would deem this as bad style. A second way has been provided for
object oriented types who believe in methods. The second way consists of
the following methods:

    my $val = $self->get_property( 'key1' );
    my $self->set_property( key1 => 'val1' );

Properties are allowed to be changed at any time with caution (please do
not undef the sock property or you will close the client connection).

CONFIGURATION FILE "Net::Server" allows for the use of a configuration file to read in server parameters. The format of this conf file is simple key value pairs. Comments and blank lines are ignored.

    #-------------- file test.conf --------------

    ### user and group to become
    user        somebody
    group       everybody

    # logging ?
    log_file    /var/log/server.log
    log_level   3
    pid_file    /tmp/server.pid

    # optional syslog directive
    # used in place of log_file above
    #log_file       Sys::Syslog
    #syslog_logsock unix
    #syslog_ident   myserver
    #syslog_logopt  pid|cons

    # access control
    allow       .+\.(net|com)
    allow       domain\.com
    deny        a.+
    cidr_allow  127.0.0.0/8
    cidr_allow  192.0.2.0/24
    cidr_deny   192.0.2.4/30

    # background the process?
    background  1

    # ports to bind (this should bind
    # 127.0.0.1:20205 on IPv6 and
    # localhost:20204 on IPv4)
    # See Net::Server::Proto
    host        127.0.0.1
    ipv         IPv6
    port        localhost:20204/IPv4
    port        20205

    # reverse lookups ?
    # reverse_lookups on

  #-------------- file test.conf --------------

PROCESS FLOW The process flow is written in an open, easy to override, easy to hook, fashion. The basic flow is shown below. This is the flow of the "$self->run" method.

    $self->configure_hook;

    $self->configure(@_);

    $self->post_configure;

    $self->post_configure_hook;

    $self->pre_bind;

    $self->bind;

    $self->post_bind_hook;

    $self->post_bind;

    $self->pre_loop_hook;

    $self->loop;

    ### routines inside a standard $self->loop
    # $self->accept;
    # $self->run_client_connection;
    # $self->done;

    $self->pre_server_close_hook;

    $self->server_close;

The server then exits.

During the client processing phase ("$self->run_client_connection"), the
following represents the program flow:

    $self->post_accept;

    $self->get_client_info;

    $self->post_accept_hook;

    if ($self->allow_deny
        && $self->allow_deny_hook) {

        $self->process_request;

    } else {

        $self->request_denied_hook;

    }

    $self->post_process_request_hook;

    $self->post_process_request;

    $self->post_client_connection_hook;

The process then loops and waits for the next connection. For a more in
depth discussion, please read the code.

During the server shutdown phase ("$self->server_close"), the following
represents the program flow:

    $self->close_children;  # if any

    $self->post_child_cleanup_hook;

    if (Restarting server) {
        $self->restart_close_hook();
        $self->hup_server;
    }

    $self->shutdown_sockets;

    $self->server_exit;

MAIN SERVER METHODS "$self->run" This method incorporates the main process flow. This flow is listed above.

    The method run may be called in any of the following ways.

         MyPackage->run(port => 20201);

         MyPackage->new({port => 20201})->run;

         my $obj = bless {server=>{port => 20201}}, 'MyPackage';
         $obj->run;

    The ->run method should typically be the last method called in a
    server start script (the server will exit at the end of the ->run
    method).

"$self->configure"
    This method attempts to read configurations from the commandline,
    from the run method call, or from a specified conf_file (the
    conf_file may be specified by passed in parameters, or in the
    default_values). All of the configured parameters are then stored in
    the {"server"} property of the Server object.

"$self->post_configure"
    The post_configure hook begins the startup of the server. During
    this method running server instances are checked for, pid_files are
    created, log_files are created, Sys::Syslog is initialized (as
    needed), process backgrounding occurs and the server closes STDIN
    and STDOUT (as needed).

"$self->pre_bind"
    This method is used to initialize all of the socket objects used by
    the server.

"$self->bind"
    This method actually binds to the inialized sockets (or rebinds if
    the server has been HUPed).

"$self->post_bind"
    During this method priveleges are dropped. The INT, TERM, and QUIT
    signals are set to run server_close. Sig PIPE is set to IGNORE. Sig
    CHLD is set to sig_chld. And sig HUP is set to call sig_hup.

    Under the Fork, PreFork, and PreFork simple personalities, these
    signals are registered using Net::Server::SIG to allow for safe
    signal handling.

"$self->loop"
    During this phase, the server accepts incoming connections. The
    behavior of how the accepting occurs and if a child process handles
    the connection is controlled by what type of Net::Server personality
    the server is using.

    Net::Server and Net::Server single accept only one connection at a
    time.

    Net::Server::INET runs one connection and then exits (for use by
    inetd or xinetd daemons).

    Net::Server::MultiPlex allows for one process to simultaneously
    handle multiple connections (but requires rewriting the
    process_request code to operate in a more "packet-like" manner).

    Net::Server::Fork forks off a new child process for each incoming
    connection.

    Net::Server::PreForkSimple starts up a fixed number of processes
    that all accept on incoming connections.

    Net::Server::PreFork starts up a base number of child processes
    which all accept on incoming connections. The server throttles the
    number of processes running depending upon the number of requests
    coming in (similar to concept to how Apache controls its child
    processes in a PreFork server).

    Read the documentation for each of the types for more information.

"$self->server_close"
    This method is called once the server has been signaled to end, or
    signaled for the server to restart (via HUP), or the loop method has
    been exited.

    This method takes care of cleaning up any remaining child processes,
    setting appropriate flags on sockets (for HUPing), closing up
    logging, and then closing open sockets.

    Can optionally be passed an exit value that will be passed to the
    server_exit call.

"$self->server_exit"
    This method is called at the end of server_close. It calls exit, but
    may be overridden to do other items. At this point all services
    should be shut down.

    Can optionally be passed an exit value that will be passed to the
    exit call.

MAIN CLIENT CONNECTION METHODS "$self->run_client_connection" This method is run after the server has accepted and received a client connection. The full process flow is listed above under PROCESS FLOWS. This method takes care of handling each client connection.

"$self->post_accept"
    This method opens STDIN and STDOUT to the client socket. This allows
    any of the methods during the run_client_connection phase to print
    directly to and read directly from the client socket.

"$self->get_client_info"
    This method looks up information about the client connection such as
    ip address, socket type, and hostname (as needed).

"$self->allow_deny"
    This method uses the rules defined in the allow and deny
    configuration parameters to determine if the ip address should be
    accepted.

"$self->process_request"
    This method is intended to handle all of the client communication.
    At this point STDIN and STDOUT are opened to the client, the ip
    address has been verified. The server can then interact with the
    client connection according to whatever API or protocol the server
    is implementing. Note that the stub implementation uses STDIN and
    STDOUT and will not work if the no_client_stdout flag is set.

    This is the main method to override.

    The default method implements a simple echo server that will repeat
    whatever is sent. It will quit the child if "quit" is sent, and will
    exit the server if "exit" is sent.

    As of version 2.000, the client handle is passed as an argument.

"$self->post_process_request"
    This method is used to clean up the client connection and to handle
    any parent/child accounting for the forking servers.

HOOKS "Net::Server" provides a number of "hooks" allowing for servers layered on top of "Net::Server" to respond at different levels of execution without having to "SUPER" class the main built-in methods. The placement of the hooks can be seen in the PROCESS FLOW section.

Almost all of the default hook methods do nothing. To use a hook you
simply need to override the method in your subclass. For example to add
your own post_configure_hook you could do something like the following:

    package MyServer;

    sub post_configure_hook {
        my $self = shift;
        my $prop = $self->{'server'};

        # do some validation here
    }

The following describes the hooks available in the plain Net::Server
class (other flavors such as Fork or PreFork have additional hooks).

"$self->configure_hook()"
    This hook takes place immediately after the "->run()" method is
    called. This hook allows for setting up the object before any built
    in configuration takes place. This allows for custom
    configurability.

"$self->post_configure_hook()"
    This hook occurs just after the reading of configuration parameters
    and initiation of logging and pid_file creation. It also occurs
    before the "->pre_bind()" and "->bind()" methods are called. This
    hook allows for verifying configuration parameters.

"$self->post_bind_hook()"
    This hook occurs just after the bind process and just before any
    chrooting, change of user, or change of group occurs. At this point
    the process will still be running as the user who started the
    server.

"$self->pre_loop_hook()"
    This hook occurs after chroot, change of user, and change of group
    has occurred. It allows for preparation before looping begins.

"$self->can_read_hook()"
    This hook occurs after a socket becomes readible on an
    accept_multi_port request (accept_multi_port is used if there are
    multiple bound ports to accept on, or if the "multi_port"
    configuration parameter is set to true). This hook is intended to
    allow for processing of arbitrary handles added to the IO::Select
    used for the accept_multi_port. These handles could be added during
    the post_bind_hook. No internal support is added for processing
    these handles or adding them to the IO::Socket. Care must be used in
    how much occurs during the can_read_hook as a long response time
    will result in the server being susceptible to DOS attacks. A return
    value of true indicates that the Server should not pass the readible
    handle on to the post_accept and process_request phases.

    It is generally suggested that other avenues be pursued for sending
    messages via sockets not created by the Net::Server.

"$self->post_accept_hook()"
    This hook occurs after a client has connected to the server. At this
    point STDIN and STDOUT are mapped to the client socket. This hook
    occurs before the processing of the request.

"$self->allow_deny_hook()"
    This hook allows for the checking of ip and host information beyond
    the "$self->allow_deny()" routine. If this hook returns 1, the
    client request will be processed, otherwise, the request will be
    denied processing.

    As of version 2.000, the client connection is passed as an argument.

"$self->request_denied_hook()"
    This hook occurs if either the "$self->allow_deny()" or
    "$self->allow_deny_hook()" have taken place.

"$self->post_process_request_hook()"
    This hook occurs after the processing of the request, but before the
    client connection has been closed.

"$self->post_client_connection_hook"
    This is one final hook that occurs at the very end of the
    run_client_connection method. At this point all other methods and
    hooks that will run during the run_client_connection have finished
    and the client connection has already been closed.

    item "$self->other_child_died_hook($pid)"

    Net::Server takes control of signal handling and child process
    cleanup; this makes it difficult to tell when a child process
    terminates if that child process was not started by Net::Server
    itself. If Net::Server notices another child process dying that it
    did not start, it will fire this hook with the PID of the terminated
    process.

"$self->pre_server_close_hook()"
    This hook occurs before the server begins shutting down.

"$self->write_to_log_hook"
    This hook handles writing to log files. The default hook is to write
    to STDERR, or to the filename contained in the parameter "log_file".
    The arguments passed are a log level of 0 to 4 (4 being very
    verbose), and a log line. If log_file is equal to "Sys::Syslog",
    then logging will go to Sys::Syslog and will bypass the
    write_to_log_hook.

"$self->fatal_hook"
    This hook occurs when the server has encountered an unrecoverable
    error. Arguments passed are the error message, the package, file,
    and line number. The hook may close the server, but it is suggested
    that it simply return and use the built in shut down features.

"$self->post_child_cleanup_hook"
    This hook occurs in the parent server process after all children
    have been shut down and just before the server either restarts or
    exits. It is intended for additional cleanup of information. At this
    point pid_files and lockfiles still exist.

"$self->restart_open_hook"
    This hook occurs if a server has been HUPed (restarted via the HUP
    signal. It occurs just before reopening to the filenos of the
    sockets that were already opened.

"$self->restart_close_hook"
    This hook occurs if a server has been HUPed (restarted via the HUP
    signal. It occurs just before restarting the server via exec.

"$self->child_init_hook()"
    This hook is called during the forking servers. It is also called
    during run_dequeue. It runs just after the fork and after signals
    have been cleaned up. If it is a dequeue process, the string
    'dequeue' will be passed as an argument.

    If your child processes will be needing random numbers, this hook is
    a good location to initialize srand (forked processes maintain the
    same random seed unless changed).

        sub child_init_hook {
            # from perldoc -f srand
            srand(time ^ $$ ^ unpack "%L*", `ps axww | gzip -f`);
        }

"$self->pre_fork_hook()"
    Similar to the child_init_hook, but occurs just before the fork.

"$self->child_finish_hook()"
    Similar to the child_init_hook, but ran when the forked process is
    about to finish up.

OTHER METHODS "$self->default_values" Allow for returning configuration values that will be used if no other value could be found.

    Should return a hashref.

        sub default_values {
            return {
                port => 20201,
            };
        }

"$self->handle_syslog_error"
    Called when log_file is set to 'Sys::Syslog' and an error occurs
    while writing to the syslog. It is passed two arguments, the value
    of $@, and an arrayref containing the arguments that were passed to
    the log method when the error occurred.

"$self->log"
    Parameters are a log_level and a message.

    If log_level is set to 'Sys::Syslog', the parameters may alternately
    be a log_level, a format string, and format string parameters. (The
    second parameter is assumed to be a format string if additional
    arguments are passed along). Passing arbitrary format strings to
    Sys::Syslog will allow the server to be vulnerable to exploit. The
    server maintainer should make sure that any string treated as a
    format string is controlled.

        # assuming log_file = 'Sys::Syslog'

        $self->log(1, "My Message with %s in it");
        # sends "%s", "My Message with %s in it" to syslog

        $self->log(1, "My Message with %s in it", "Foo");
        # sends "My Message with %s in it", "Foo" to syslog

    If log_file is set to a file (other than Sys::Syslog), the message
    will be appended to the log file by calling the write_to_log_hook.

    If the log_file is Sys::Syslog and an error occurs during write, the
    handle_syslog_error method will be called and passed the error
    exception. The default option of handle_syslog_error is to die - but
    could easily be told to do nothing by using the following code in
    your subclassed server:

        sub handle_syslog_error {}

    It the log had been closed, you could attempt to reopen it in the
    error handler with the following code:

        sub handle_syslog_error {
            my $self = shift;
            $self->open_syslog;
        }

"$self->new"
    As of Net::Server 0.91 there is finally a "new" method. This method
    takes a class name and an argument hashref as parameters. The
    argument hashref becomes the "server" property of the object.

        package MyPackage;
        use base qw(Net::Server);

        my $obj = MyPackage->new({port => 20201});

        # same as

        my $obj = bless {server => {port => 20201}}, 'MyPackage';

"$self->open_syslog"
    Called during post_configure when the log_file option is set to
    'Sys::Syslog'. By default it use the parsed configuration options
    listed in this document. If more custom behavior is desired, the
    method could be overridden and Sys::Syslog::openlog should be called
    with the custom parameters.

"$self->shutdown_sockets"
    This method will close any remaining open sockets. This is called at
    the end of the server_close method.

RESTARTING Each of the server personalities (except for INET), support restarting via a HUP signal (see "kill -l"). When a HUP is received, the server will close children (if any), make sure that sockets are left open, and re-exec using the same commandline parameters that initially started the server. (Note: for this reason it is important that @ARGV is not modified until "->run" is called).

The Net::Server will attempt to find out the commandline used for
starting the program. The attempt is made before any configuration files
or other arguments are processed. The outcome of this attempt is stored
using the method "->commandline". The stored commandline may also be
retrieved using the same method name. The stored contents will
undoubtedly contain Tainted items that will cause the server to die
during a restart when using the -T flag (Taint mode). As it is
impossible to arbitrarily decide what is taint safe and what is not, the
individual program must clean up the tainted items before doing a
restart.

    sub configure_hook{
        my $self = shift;

        ### see the contents
        my $ref  = $self->commandline;
        use Data::Dumper;
        print Dumper $ref;

        ### arbitrary untainting - VERY dangerous
        my @untainted = map {/(.+)/;$1} @$ref;

        $self->commandline(\@untainted)
    }

SHUTDOWN Each of the Fork and PreFork personalities support graceful shutdowns via the QUIT signal. When a QUIT is received, the parent will signal the children and then wait for them to exit.

All server personalities support the normal TERM and INT signal
shutdowns.

HOT DEPLOY Since version 2.000, the Fork and PreFork personalities have accepted the TTIN and TTOU signals. When a TTIN is received, the max_servers is increased by 1. If a TTOU signal is received the max_servers is decreased by 1. This allows for adjusting the number of handling processes without having to restart the server.

If the log_level is set to at 3, then the new value is displayed in the
logs.

FILES The following files are installed as part of this distribution.

    Net/Server.pm
    Net/Server/Fork.pm
    Net/Server/INET.pm
    Net/Server/MultiType.pm
    Net/Server/PreForkSimple.pm
    Net/Server/PreFork.pm
    Net/Server/Single.pm
    Net/Server/Daemonize.pm
    Net/Server/SIG.pm
    Net/Server/Proto.pm
    Net/Server/Proto/*.pm

INSTALL Download and extract tarball before running these commands in its base directory:

    perl Makefile.PL
    make
    make test
    make install

AUTHOR Paul Seamons

THANKS Thanks to Rob Brown (bbb at cpan.org) for help with miscellaneous concepts such as tracking down the serialized select via flock ala Apache and the reference to IO::Select making multiport servers possible. And for researching into allowing sockets to remain open upon exec (making HUP possible).

Thanks to Jonathan J. Miner <miner at doit.wisc.edu> for patching a
blatant problem in the reverse lookups.

Thanks to Bennett Todd <bet at rahul.net> for pointing out a problem in
Solaris 2.5.1 which does not allow multiple children to accept on the
same port at the same time. Also for showing some sample code from
Viktor Duchovni which now represents the semaphore option of the
serialize argument in the PreFork server.

Thanks to *traveler* and *merlyn* from http://perlmonks.org for pointing
me in the right direction for determining the protocol used on a socket
connection.

Thanks to Jeremy Howard <j+daemonize at howard.fm> for numerous
suggestions and for work on Net::Server::Daemonize.

Thanks to Vadim <vadim at hardison.net> for patches to implement
parent/child communication on PreFork.pm.

Thanks to Carl Lewis for suggesting "-" in user names.

Thanks to Slaven Rezic for suggesing Reuse => 1 in Proto::UDP.

Thanks to Tim Watt for adding udp_broadcast to Proto::UDP.

Thanks to Christopher A Bongaarts for pointing out problems with the
Proto::SSL implementation that currently locks around the socket accept
and the SSL negotiation. See Net::Server::Proto::SSL.

Thanks to Alessandro Zummo for pointing out various bugs including some
in configuration, commandline args, and cidr_allow.

Thanks to various other people for bug fixes over the years. These and
future thank-you's are available in the Changes file as well as CVS
comments.

Thanks to Ben Cohen and tye (on Permonks) for finding and diagnosing
more correct behavior for dealing with re-opening STDIN and STDOUT on
the client handles.

Thanks to Mark Martinec for trouble shooting other problems with STDIN
and STDOUT (he proposed having a flag that is now the no_client_stdout
flag).

Thanks to David (DSCHWEI) on cpan for asking for the nofatal option with
syslog.

Thanks to Andreas Kippnick and Peter Beckman for suggesting leaving open
child connections open during a HUP (this is now available via the
leave_children_open_on_hup flag).

Thanks to LUPE on cpan for helping patch HUP with taint on.

Thanks to Michael Virnstein for fixing a bug in the check_for_dead
section of PreFork server.

Thanks to Rob Mueller for patching PreForkSimple to only open lock_file
once during parent call. This patch should be portable on systems
supporting flock. Rob also suggested not closing STDIN/STDOUT but
instead reopening them to /dev/null to prevent spurious warnings. Also
suggested short circuit in post_accept if in UDP. Also for cleaning up
some of the child managment code of PreFork.

Thanks to Mark Martinec for suggesting additional log messages for
failure during accept.

Thanks to Bill Nesbitt and Carlos Velasco for pointing out double
decrement bug in PreFork.pm (rt #21271)

Thanks to John W. Krahn for pointing out glaring precended with
non-parened open and ||.

Thanks to Ricardo Signes for pointing out setuid bug for perl 5.6.1 (rt
#21262).

Thanks to Carlos Velasco for updating the Syslog options (rt #21265).
And for additional fixes later.

Thanks to Steven Lembark for pointing out that no_client_stdout wasn't
working with the Multiplex server.

Thanks to Peter Beckman for suggesting allowing Sys::SysLog keyworks be
passed through the ->log method and for suggesting we allow more types
of characters through in syslog_ident. Also to Peter Beckman for
pointing out that a poorly setup localhost will cause tests to hang.

Thanks to Curtis Wilbar for pointing out that the Fork server called
post_accept_hook twice. Changed to only let the child process call this,
but added the pre_fork_hook method.

And just a general Thanks You to everybody who is using Net::Server or
who has contributed fixes over the years.

Thanks to Paul Miller for some ->autoflush, FileHandle fixes.

Thanks to Patrik Wallstrom for suggesting handling syslog errors better.

Thanks again to Rob Mueller for more logic cleanup for child accounting
in PreFork server.

Thanks to David Schweikert for suggesting handling setlogsock a little
better on newer versions of Sys::Syslog (>= 0.15).

Thanks to Mihail Nasedkin for suggesting adding a hook that is now
called post_client_connection_hook.

Thanks to Graham Barr for adding the ability to set the check_for_spawn
and min_child_ttl settings of the PreFork server.

Thanks to Daniel Kahn Gillmor for adding the other_child_died_hook.

Thanks to Dominic Humphries for helping not kill pid files on HUP.

Thanks to Kristoffer Møllerhøj for fixing UDP on Multiplex.

Thanks to mishikal for patches for helping identify un-cleaned up
children.

Thanks to rpkelly and tim@retout for pointing out error in header regex
of HTTP.

Thanks to dmcbride for some basic HTTP parsing fixes, as well as for
some broken tied handle fixes.

Thanks to Gareth for pointing out glaring bug issues with broken pipe
and semaphore serialization.

Thanks to CATONE for sending the idea for arbitrary signal passing to
children. (See the sig_passthrough option)

Thanks to intrigeri@boum for pointing out and giving code ideas for
NS_port not functioning after a HUP.

Thanks to Sergey Zasenko for adding sysread/syswrite support to SSLEAY
as well as the base test.

Thanks to mbarbon@users. for adding tally dequeue to prefork server.

Thanks to stefanos@cpan for fixes to PreFork under Win32

Thanks to Mark Martinec for much of the initial work towards getting
IPv6 going.

Thanks to the munin developers and Nicolai Langfeldt for hosting the
development verion of Net::Server for so long and for fixes to the
allow_deny checking for IPv6 addresses.

Thanks to Tatsuhiko Miyagawa for feedback, and for suggesting adding
graceful shutdowns and hot deploy (max_servers adjustment).

Thanks to TONVOON@cpan for submitting a patch adding Log4perl
functionality.

Thanks to Miko O'Sullivan for fixes to HTTP to correct tainting issues
and passing initial log fixes, and for patches to fix CLOSE on tied
stdout and various other HTTP issues.

SEE ALSO Please see also Net::Server::Fork, Net::Server::INET, Net::Server::PreForkSimple, Net::Server::PreFork, Net::Server::MultiType, Net::Server::Single Net::Server::HTTP

TODO Improve test suite to fully cover code (using Devel::Cover). Anybody that wanted to send me patches to the t/*.t tests that improved coverage would earn a big thank you.

CODE REPOSITORY https://github.com/rhandom/perl-net-server

AUTHOR Paul Seamons http://seamons.com/

    Rob Brown <bbb at cpan.org>

LICENSE This package may be distributed under the terms of either the

  GNU General Public License
    or the
  Perl Artistic License

All rights reserved.