package Net::Ping;
-# $Id: Ping.pm,v 1.1 2002/06/04 00:41:52 rob Exp $
+# $Id: Ping.pm,v 1.46 2002/12/02 19:17:09 rob Exp $
require 5.002;
require Exporter;
use strict;
use vars qw(@ISA @EXPORT $VERSION
- $def_timeout $def_proto $max_datasize $pingstring $hires $udp_source_verify);
-use FileHandle;
-use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET
+ $def_timeout $def_proto $max_datasize $pingstring $hires $source_verify $syn_forking);
+use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK );
+use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET
inet_aton inet_ntoa sockaddr_in );
+use POSIX qw( ECONNREFUSED EINPROGRESS EAGAIN WNOHANG );
+use FileHandle;
use Carp;
-use POSIX qw(ECONNREFUSED);
@ISA = qw(Exporter);
@EXPORT = qw(pingecho);
-$VERSION = "2.19";
+$VERSION = "2.26";
# Constants
$max_datasize = 1024; # Maximum data bytes in a packet
# The data we exchange with the server for the stream protocol
$pingstring = "pingschwingping!\n";
-$udp_source_verify = 1; # Default is to verify source endpoint
+$source_verify = 1; # Default is to verify source endpoint
+$syn_forking = 0;
if ($^O =~ /Win32/i) {
# Hack to avoid this Win32 spewage:
# Your vendor has not defined POSIX macro ECONNREFUSED
*ECONNREFUSED = sub {10061;}; # "Unknown Error" Special Win32 Response?
+ $syn_forking = 1;
};
+# h2ph "asm/socket.h"
+# require "asm/socket.ph";
+sub SO_BINDTODEVICE {25;}
+
# Description: The pingecho() subroutine is provided for backward
# compatibility with the original Net::Ping. It accepts a host
# name/IP and an optional timeout in seconds. Create a tcp ping
my ($this,
$proto, # Optional protocol to use for pinging
$timeout, # Optional timeout in seconds
- $data_size # Optional additional bytes of data
+ $data_size, # Optional additional bytes of data
+ $device, # Optional device to use
) = @_;
my $class = ref($this) || $this;
my $self = {};
bless($self, $class);
$proto = $def_proto unless $proto; # Determine the protocol
- croak('Protocol for ping must be "icmp", "udp", "tcp", "stream", or "external"')
- unless $proto =~ m/^(icmp|udp|tcp|stream|external)$/;
+ croak('Protocol for ping must be "icmp", "udp", "tcp", "syn", "stream", or "external"')
+ unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/;
$self->{"proto"} = $proto;
$timeout = $def_timeout unless $timeout; # Determine the timeout
if $timeout <= 0;
$self->{"timeout"} = $timeout;
+ $self->{"device"} = $device;
+
$min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size
$data_size = $min_datasize unless defined($data_size) && $proto ne "tcp";
croak("Data for ping must be from $min_datasize to $max_datasize bytes")
$self->{"local_addr"} = undef; # Don't bind by default
+ $self->{"tcp_econnrefused"} = undef; # Default Connection refused behavior
+
$self->{"seq"} = 0; # For counting packets
if ($self->{"proto"} eq "udp") # Open a socket
{
socket($self->{"fh"}, PF_INET, SOCK_DGRAM,
$self->{"proto_num"}) ||
croak("udp socket error - $!");
+ if ($self->{'device'}) {
+ setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
+ or croak "error binding to device $self->{'device'} $!";
+ }
}
elsif ($self->{"proto"} eq "icmp")
{
- croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS');
+ croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS' and $^O ne 'cygwin');
$self->{"proto_num"} = (getprotobyname('icmp'))[2] ||
croak("Can't get icmp protocol by name");
$self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid
$self->{"fh"} = FileHandle->new();
socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) ||
croak("icmp socket error - $!");
+ if ($self->{'device'}) {
+ setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
+ or croak "error binding to device $self->{'device'} $!";
+ }
}
elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream")
{
croak("Can't get tcp echo port by name");
$self->{"fh"} = FileHandle->new();
}
+ elsif ($self->{"proto"} eq "syn")
+ {
+ $self->{"proto_num"} = (getprotobyname('tcp'))[2] ||
+ croak("Can't get tcp protocol by name");
+ $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] ||
+ croak("Can't get tcp echo port by name");
+ if ($syn_forking) {
+ $self->{"fork_rd"} = FileHandle->new();
+ $self->{"fork_wr"} = FileHandle->new();
+ pipe($self->{"fork_rd"}, $self->{"fork_wr"});
+ $self->{"fh"} = FileHandle->new();
+ $self->{"good"} = {};
+ $self->{"bad"} = {};
+ } else {
+ $self->{"wbits"} = "";
+ $self->{"bad"} = {};
+ }
+ $self->{"syn"} = {};
+ $self->{"stop_time"} = 0;
+ }
+ elsif ($self->{"proto"} eq "external")
+ {
+ # No preliminary work needs to be done.
+ }
return($self);
}
sub source_verify
{
my $self = shift;
- $udp_source_verify = 1 unless defined
- ($udp_source_verify = ((defined $self) && (ref $self)) ? shift() : $self);
+ $source_verify = 1 unless defined
+ ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self);
+}
+
+# Description: Set whether or not the tcp connect
+# behavior should enforce remote service availability
+# as well as reachability.
+
+sub tcp_service_check
+{
+ my $self = shift;
+ $self->{"tcp_econnrefused"} = 1 unless defined
+ ($self->{"tcp_econnrefused"} = shift());
}
# Description: allows the module to use milliseconds as returned by
}
elsif ($self->{"proto"} eq "stream") {
$ret = $self->ping_stream($ip, $timeout);
+ }
+ elsif ($self->{"proto"} eq "syn") {
+ $ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$timeout);
} else {
croak("Unknown protocol \"$self->{proto}\" in ping()");
}
substr($recv_msg, length($recv_msg) - $len_msg,
$len_msg));
if (($from_type == ICMP_ECHOREPLY) &&
- ($from_ip eq $ip) &&
+ (!$source_verify || $from_ip eq $ip) &&
($from_pid == $self->{"pid"}) && # Does the packet check out?
($from_seq == $self->{"seq"}))
{
$@ = ""; $! = 0;
$ret = $self -> tcp_connect( $ip, $timeout);
- $ret = 1 if $! == ECONNREFUSED; # Connection refused
+ if (!$self->{"tcp_econnrefused"} &&
+ $! == ECONNREFUSED) {
+ $ret = 1; # "Connection refused" means reachable
+ }
$self->{"fh"}->close();
return $ret;
}
!CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) {
croak("tcp bind error - $!");
}
+ if ($self->{'device'}) {
+ setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
+ or croak("error binding to device $self->{'device'} $!");
+ }
};
my $do_connect = sub {
eval {
my $patience = &time() + $timeout;
- require POSIX;
my ($child);
$? = 0;
# Wait up to the timeout
# And clean off the zombie
do {
- $child = waitpid($pid, &POSIX::WNOHANG);
+ $child = waitpid($pid, &WNOHANG());
$! = $? >> 8;
$@ = $!;
select(undef, undef, undef, 0.1);
&{ $do_socket }();
- $SIG{'ALRM'} = sub { die "Timed out!"; };
- alarm($timeout); # Interrupt connect() if we have to
+ local $SIG{'ALRM'} = sub { die "Timed out!"; };
+ my $old = alarm($timeout); # Interrupt connect() if we have to
&{ $do_connect }();
- alarm(0);
+ alarm($old);
}
return $ret;
# of time. Return the result of our efforts.
use constant UDP_FLAGS => 0; # Nothing special on send or recv
-
+# XXX - Use concept by rdw @ perlmonks
+# http://perlmonks.thepen.com/42898.html
sub ping_udp
{
my ($self,
$from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS)
or last; # For example an unreachable host will make recv() fail.
($from_port, $from_ip) = sockaddr_in($from_saddr);
- if (!$udp_source_verify ||
+ if (!$source_verify ||
(($from_ip eq $ip) && # Does the packet check out?
($from_port == $self->{"port_num"}) &&
($from_msg eq $msg)))
return $ret;
}
-# Description: Close the connection unless we are using the tcp
-# protocol, since it will already be closed.
+# Description: Send a TCP SYN packet to host specified.
+sub ping_syn
+{
+ my $self = shift;
+ my $host = shift;
+ my $ip = shift;
+ my $start_time = shift;
+ my $stop_time = shift;
+
+ if ($syn_forking) {
+ return $self->ping_syn_fork($host, $ip, $start_time, $stop_time);
+ }
+
+ my $fh = FileHandle->new();
+ my $saddr = sockaddr_in($self->{"port_num"}, $ip);
+
+ # Create TCP socket
+ if (!socket ($fh, PF_INET, SOCK_STREAM, $self->{"proto_num"})) {
+ croak("tcp socket error - $!");
+ }
+
+ if (defined $self->{"local_addr"} &&
+ !CORE::bind($fh, sockaddr_in(0, $self->{"local_addr"}))) {
+ croak("tcp bind error - $!");
+ }
+
+ if ($self->{'device'}) {
+ setsockopt($fh, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
+ or croak("error binding to device $self->{'device'} $!");
+ }
+
+ # Set O_NONBLOCK property on filehandle
+ my $flags = 0;
+ if (fcntl($fh, F_GETFL, $flags)) {
+ if (!fcntl($fh, F_SETFL, $flags | O_NONBLOCK)) {
+ croak("fcntl F_SETFL: $!");
+ }
+ } else {
+ croak("fcntl F_GETFL: $!");
+ }
+
+ # Attempt the non-blocking connect
+ # by just sending the TCP SYN packet
+ if (connect($fh, $saddr)) {
+ # Non-blocking, yet still connected?
+ # Must have connected very quickly,
+ # or else it wasn't very non-blocking.
+ #warn "WARNING: Nonblocking connect connected anyway? ($^O)";
+ } else {
+ # Error occurred connecting.
+ if ($! == EINPROGRESS) {
+ # The connection is just still in progress.
+ # This is the expected condition.
+ } else {
+ # Just save the error and continue on.
+ # The ack() can check the status later.
+ $self->{"bad"}->{$host} = $!;
+ }
+ }
+
+ my $entry = [ $host, $ip, $fh, $start_time, $stop_time ];
+ $self->{"syn"}->{$fh->fileno} = $entry;
+ if ($self->{"stop_time"} < $stop_time) {
+ $self->{"stop_time"} = $stop_time;
+ }
+ vec($self->{"wbits"}, $fh->fileno, 1) = 1;
+
+ return 1;
+}
+
+sub ping_syn_fork {
+ my ($self, $host, $ip, $start_time, $stop_time) = @_;
+
+ # Buggy Winsock API doesn't allow nonblocking connect.
+ # Hence, if our OS is Windows, we need to create a separate
+ # process to do the blocking connect attempt.
+ my $pid = fork();
+ if (defined $pid) {
+ if ($pid) {
+ # Parent process
+ my $entry = [ $host, $ip, $pid, $start_time, $stop_time ];
+ $self->{"syn"}->{$pid} = $entry;
+ if ($self->{"stop_time"} < $stop_time) {
+ $self->{"stop_time"} = $stop_time;
+ }
+ } else {
+ # Child process
+ my $saddr = sockaddr_in($self->{"port_num"}, $ip);
+
+ # Create TCP socket
+ if (!socket ($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"})) {
+ croak("tcp socket error - $!");
+ }
+
+ if (defined $self->{"local_addr"} &&
+ !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) {
+ croak("tcp bind error - $!");
+ }
+
+ if ($self->{'device'}) {
+ setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
+ or croak("error binding to device $self->{'device'} $!");
+ }
+
+ $!=0;
+ # Try to connect (could take a long time)
+ connect($self->{"fh"}, $saddr);
+ # Notify parent of connect error status
+ my $err = $!+0;
+ my $wrstr = "$$ $err";
+ # Force to 10 chars including \n
+ $wrstr .= " "x(9 - length $wrstr). "\n";
+ syswrite($self->{"fork_wr"}, $wrstr);
+ exit;
+ }
+ } else {
+ # fork() failed?
+ die "fork: $!";
+ }
+ return 1;
+}
+
+# Description: Wait for TCP ACK from host specified
+# from ping_syn above. If no host is specified, wait
+# for TCP ACK from any of the hosts in the SYN queue.
+sub ack
+{
+ my $self = shift;
+
+ if ($self->{"proto"} eq "syn") {
+ if ($syn_forking) {
+ my @answer = $self->ack_unfork(shift);
+ return wantarray ? @answer : $answer[0];
+ }
+ my $wbits = "";
+ my $stop_time = 0;
+ if (my $host = shift) {
+ # Host passed as arg
+ if (exists $self->{"bad"}->{$host}) {
+ if (!$self->{"tcp_econnrefused"} &&
+ $self->{"bad"}->{ $host } &&
+ (($! = ECONNREFUSED)>0) &&
+ $self->{"bad"}->{ $host } eq "$!") {
+ # "Connection refused" means reachable
+ # Good, continue
+ } else {
+ # ECONNREFUSED means no good
+ return ();
+ }
+ }
+ my $host_fd = undef;
+ foreach my $fd (keys %{ $self->{"syn"} }) {
+ my $entry = $self->{"syn"}->{$fd};
+ if ($entry->[0] eq $host) {
+ $host_fd = $fd;
+ $stop_time = $entry->[4]
+ || croak("Corrupted SYN entry for [$host]");
+ last;
+ }
+ }
+ croak("ack called on [$host] without calling ping first!")
+ unless defined $host_fd;
+ vec($wbits, $host_fd, 1) = 1;
+ } else {
+ # No $host passed so scan all hosts
+ # Use the latest stop_time
+ $stop_time = $self->{"stop_time"};
+ # Use all the bits
+ $wbits = $self->{"wbits"};
+ }
+
+ while ($wbits !~ /^\0*$/) {
+ my $timeout = $stop_time - &time();
+ # Force a minimum of 10 ms timeout.
+ $timeout = 0.01 if $timeout <= 0.01;
+
+ my $winner_fd = undef;
+ my $wout = $wbits;
+ my $fd = 0;
+ # Do "bad" fds from $wbits first
+ while ($wout !~ /^\0*$/) {
+ if (vec($wout, $fd, 1)) {
+ # Wipe it from future scanning.
+ vec($wout, $fd, 1) = 0;
+ if (my $entry = $self->{"syn"}->{$fd}) {
+ if ($self->{"bad"}->{ $entry->[0] }) {
+ $winner_fd = $fd;
+ last;
+ }
+ }
+ }
+ $fd++;
+ }
+
+ if (defined($winner_fd) or my $nfound = select(undef, ($wout=$wbits), undef, $timeout)) {
+ if (defined $winner_fd) {
+ $fd = $winner_fd;
+ } else {
+ # Done waiting for one of the ACKs
+ $fd = 0;
+ # Determine which one
+ while ($wout !~ /^\0*$/ &&
+ !vec($wout, $fd, 1)) {
+ $fd++;
+ }
+ }
+ if (my $entry = $self->{"syn"}->{$fd}) {
+ # Wipe it from future scanning.
+ delete $self->{"syn"}->{$fd};
+ vec($self->{"wbits"}, $fd, 1) = 0;
+ vec($wbits, $fd, 1) = 0;
+ if (!$self->{"tcp_econnrefused"} &&
+ $self->{"bad"}->{ $entry->[0] } &&
+ (($! = ECONNREFUSED)>0) &&
+ $self->{"bad"}->{ $entry->[0] } eq "$!") {
+ # "Connection refused" means reachable
+ # Good, continue
+ } elsif (getpeername($entry->[2])) {
+ # Connection established to remote host
+ # Good, continue
+ } else {
+ # TCP ACK will never come from this host
+ # because there was an error connecting.
+
+ # This should set $! to the correct error.
+ my $char;
+ read($entry->[2],$char,1);
+ # Store the excuse why the connection failed.
+ $self->{"bad"}->{$entry->[0]} = $!;
+ if (!$self->{"tcp_econnrefused"} &&
+ (($! == ECONNREFUSED) ||
+ ($! == EAGAIN && $^O =~ /cygwin/i))) {
+ # "Connection refused" means reachable
+ # Good, continue
+ } else {
+ # No good, try the next socket...
+ next;
+ }
+ }
+ # Everything passed okay, return the answer
+ return wantarray ?
+ ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1]))
+ : $entry->[0];
+ } else {
+ warn "Corrupted SYN entry: unknown fd [$fd] ready!";
+ vec($wbits, $fd, 1) = 0;
+ vec($self->{"wbits"}, $fd, 1) = 0;
+ }
+ } elsif (defined $nfound) {
+ # Timed out waiting for ACK
+ foreach my $fd (keys %{ $self->{"syn"} }) {
+ if (vec($wbits, $fd, 1)) {
+ my $entry = $self->{"syn"}->{$fd};
+ $self->{"bad"}->{$entry->[0]} = "Timed out";
+ vec($wbits, $fd, 1) = 0;
+ vec($self->{"wbits"}, $fd, 1) = 0;
+ delete $self->{"syn"}->{$fd};
+ }
+ }
+ } else {
+ # Weird error occurred with select()
+ warn("select: $!");
+ $self->{"syn"} = {};
+ $wbits = "";
+ }
+ }
+ }
+ return ();
+}
+
+sub ack_unfork {
+ my ($self,$host) = @_;
+ my $stop_time = $self->{"stop_time"};
+ if ($host) {
+ # Host passed as arg
+ if (my $entry = $self->{"good"}->{$host}) {
+ delete $self->{"good"}->{$host};
+ return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1]));
+ }
+ }
+
+ my $rbits = "";
+ my $timeout;
+
+ if (keys %{ $self->{"syn"} }) {
+ # Scan all hosts that are left
+ vec($rbits, fileno($self->{"fork_rd"}), 1) = 1;
+ $timeout = $stop_time - &time();
+ # Force a minimum of 10 ms timeout.
+ $timeout = 0.01 if $timeout < 0.01;
+ } else {
+ # No hosts left to wait for
+ $timeout = 0;
+ }
+
+ if ($timeout > 0) {
+ my $nfound;
+ while ( keys %{ $self->{"syn"} } and
+ $nfound = select((my $rout=$rbits), undef, undef, $timeout)) {
+ # Done waiting for one of the ACKs
+ if (!sysread($self->{"fork_rd"}, $_, 10)) {
+ # Socket closed, which means all children are done.
+ return ();
+ }
+ my ($pid, $how) = split;
+ if ($pid) {
+ # Flush the zombie
+ waitpid($pid, 0);
+ if (my $entry = $self->{"syn"}->{$pid}) {
+ # Connection attempt to remote host is done
+ delete $self->{"syn"}->{$pid};
+ if (!$how || # If there was no error connecting
+ (!$self->{"tcp_econnrefused"} &&
+ $how == ECONNREFUSED)) { # "Connection refused" means reachable
+ if ($host && $entry->[0] ne $host) {
+ # A good connection, but not the host we need.
+ # Move it from the "syn" hash to the "good" hash.
+ $self->{"good"}->{$entry->[0]} = $entry;
+ # And wait for the next winner
+ next;
+ }
+ return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1]));
+ }
+ } else {
+ # Should never happen
+ die "Unknown ping from pid [$pid]";
+ }
+ } else {
+ die "Empty response from status socket?";
+ }
+ }
+ if (defined $nfound) {
+ # Timed out waiting for ACK status
+ } else {
+ # Weird error occurred with select()
+ warn("select: $!");
+ }
+ }
+ if (my @synners = keys %{ $self->{"syn"} }) {
+ # Kill all the synners
+ kill 9, @synners;
+ foreach my $pid (@synners) {
+ # Wait for the deaths to finish
+ # Then flush off the zombie
+ waitpid($pid, 0);
+ }
+ }
+ $self->{"syn"} = {};
+ return ();
+}
+
+# Description: Tell why the ack() failed
+sub nack {
+ my $self = shift;
+ my $host = shift || croak('Usage> nack($failed_ack_host)');
+ return $self->{"bad"}->{$host} || undef;
+}
+
+# Description: Close the connection.
sub close
{
my ($self) = @_;
- $self->{"fh"}->close() unless $self->{"proto"} eq "tcp";
+ if ($self->{"proto"} eq "syn") {
+ delete $self->{"syn"};
+ } elsif ($self->{"proto"} eq "tcp") {
+ # The connection will already be closed
+ } else {
+ $self->{"fh"}->close();
+ }
}
Net::Ping - check a remote host for reachability
-$Id: Ping.pm,v 1.1 2002/06/04 00:41:52 rob Exp $
+$Id: Ping.pm,v 1.46 2002/12/02 19:17:09 rob Exp $
=head1 SYNOPSIS
}
undef($p);
+ # Like tcp protocol, but with many hosts
+ $p = Net::Ping->new("syn");
+ $p->{port_num} = getservbyname("http", "tcp");
+ foreach $host (@host_array) {
+ $p->ping($host);
+ }
+ while (($host,$rtt,$ip) = $p->ack) {
+ print "HOST: $host [$ip] ACKed in $rtt seconds.\n";
+ }
+
# High precision syntax (requires Time::HiRes)
$p = Net::Ping->new();
$p->hires();
parameters, a variable number of hosts may be pinged multiple
times and then the connection is closed.
-You may choose one of four different protocols to use for the
-ping. The "udp" protocol is the default. Note that a live remote host
+You may choose one of six different protocols to use for the
+ping. The "tcp" protocol is the default. Note that a live remote host
may still fail to be pingable by one or more of these protocols. For
-example, www.microsoft.com is generally alive but not pingable.
+example, www.microsoft.com is generally alive but not "icmp" pingable.
With the "tcp" protocol the ping() method attempts to establish a
connection to the remote host's echo port. If the connection is
accurate results. If C<Net::Ping::External> if not installed on your
system, specifying the "external" protocol will result in an error.
+If the "syn" protocol is specified, the ping() method will only
+send a TCP SYN packet to the remote host then immediately return.
+If the syn packet was sent successfully, it will return a true value,
+otherwise it will return false. NOTE: Unlike the other protocols,
+the return value does NOT determine if the remote host is alive or
+not since the full TCP three-way handshake may not have completed
+yet. The remote host is only considered reachable if it receives
+a TCP ACK within the timeout specifed. To begin waiting for the
+ACK packets, use the ack() method as explained below. Use the
+"syn" protocol instead the "tcp" protocol to determine reachability
+of multiple destinations simultaneously by sending parallel TCP
+SYN packets. It will not block while testing each remote host.
+demo/fping is provided in this distribution to demonstrate the
+"syn" protocol as an example.
+This protocol does not require any special privileges.
+
=head2 Functions
=over 4
-=item Net::Ping->new([$proto [, $def_timeout [, $bytes]]]);
+=item Net::Ping->new([$proto [, $def_timeout [, $bytes [, $device ]]]]);
Create a new ping object. All of the parameters are optional. $proto
specifies the protocol to use when doing a ping. The current choices
-are "tcp", "udp" or "icmp". The default is "udp".
+are "tcp", "udp", "icmp", "stream", "syn", or "external".
+The default is "tcp".
If a default timeout ($def_timeout) in seconds is provided, it is used
when a timeout is not given to the ping() method (below). The timeout
otherwise. The maximum number of data bytes that can be specified is
1024.
+If $device is given, this device is used to bind the source endpoint
+before sending the ping packet. I beleive this only works with
+superuser privileges and with udp and icmp protocols at this time.
+
+=item $p->ping($host [, $timeout]);
+
+Ping the remote host and wait for a response. $host can be either the
+hostname or the IP number of the remote host. The optional timeout
+must be greater than 0 seconds and defaults to whatever was specified
+when the ping object was created. Returns a success flag. If the
+hostname cannot be found or there is a problem with the IP number, the
+success flag returned will be undef. Otherwise, the success flag will
+be 1 if the host is reachable and 0 if it is not. For most practical
+purposes, undef and 0 and can be treated as the same case. In array
+context, the elapsed time as well as the string form of the ip the
+host resolved to are also returned. The elapsed time value will
+be a float, as retuned by the Time::HiRes::time() function, if hires()
+has been previously called, otherwise it is returned as an integer.
+
=item $p->source_verify( { 0 | 1 } );
Allows source endpoint verification to be enabled or disabled.
This is useful for those remote destinations with multiples
interfaces where the response may not originate from the same
endpoint that the original destination endpoint was sent to.
+This only affects udp and icmp protocol pings.
This is enabled by default.
+=item $p->tcp_service_check( { 0 | 1 } );
+
+Set whether or not the tcp connect behavior should enforce
+remote service availability as well as reachability. Normally,
+if the remote server reported ECONNREFUSED, it must have been
+reachable because of the status packet that it reported.
+With this option enabled, the full three-way tcp handshake
+must have been established successfully before it will
+claim it is reachable. NOTE: It still does nothing more
+than connect and disconnect. It does not speak any protocol
+(i.e., HTTP or FTP) to ensure the remote server is sane in
+any way. The remote server CPU could be grinding to a halt
+and unresponsive to any clients connecting, but if the kernel
+throws the ACK packet, it is considered alive anyway. To
+really determine if the server is responding well would be
+application specific and is beyond the scope of Net::Ping.
+
+This only affects "tcp" and "syn" protocols.
+
+This is disabled by default.
+
=item $p->hires( { 0 | 1 } );
Causes this module to use Time::HiRes module, allowing milliseconds
called at all) must be called before the first call to ping() for that
object.
-=item $p->ping($host [, $timeout]);
-
-Ping the remote host and wait for a response. $host can be either the
-hostname or the IP number of the remote host. The optional timeout
-must be greater than 0 seconds and defaults to whatever was specified
-when the ping object was created. Returns a success flag. If the
-hostname cannot be found or there is a problem with the IP number, the
-success flag returned will be undef. Otherwise, the success flag will
-be 1 if the host is reachable and 0 if it is not. For most practical
-purposes, undef and 0 and can be treated as the same case. In array
-context, the elapsed time is also returned. The elapsed time value will
-be a float, as retuned by the Time::HiRes::time() function, if hires()
-has been previously called, otherwise it is returned as an integer.
-
=item $p->open($host);
-When you are using the stream protocol, this call pre-opens the
+When you are using the "stream" protocol, this call pre-opens the
tcp socket. It's only necessary to do this if you want to
provide a different timeout when creating the connection, or
remove the overhead of establishing the connection from the
This call simply does nothing if you are using any protocol other
than stream.
+=item $p->ack( [ $host ] );
+
+When using the "syn" protocol, use this method to determine
+the reachability of the remote host. This method is meant
+to be called up to as many times as ping() was called. Each
+call returns the host (as passed to ping()) that came back
+with the TCP ACK. The order in which the hosts are returned
+may not necessarily be the same order in which they were
+SYN queued using the ping() method. If the timeout is
+reached before the TCP ACK is received, or if the remote
+host is not listening on the port attempted, then the TCP
+connection will not be established and ack() will return
+undef. In list context, the host, the ack time, and the
+dotted ip string will be returned instead of just the host.
+If the optional $host argument is specified, the return
+value will be partaining to that host only.
+This call simply does nothing if you are using any protocol
+other than syn.
+
+=item $p->nack( $failed_ack_host );
+
+The reason that host $failed_ack_host did not receive a
+valid ACK. Useful to find out why when ack( $fail_ack_host )
+returns a false value.
+
=item $p->close();
Close the network connection for this ping object. The network
separate module to be written which understands all of the different
kinds of ICMP packets.
+=head1 INSTALL
+
+The latest source tree is available via cvs:
+
+ cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping
+ cd Net-Ping
+
+The tarball can be created as follows:
+
+ perl Makefile.PL ; make ; make dist
+
+The latest Net::Ping release can be found at CPAN:
+
+ $CPAN/modules/by-module/Net/
+
+1) Extract the tarball
+
+ gtar -zxvf Net-Ping-xxxx.tar.gz
+ cd Net-Ping-xxxx
+
+2) Build:
+
+ make realclean
+ perl Makefile.PL
+ make
+ make test
+
+3) Install
+
+ make install
+
+Or install it RPM Style:
+
+ rpm -ta SOURCES/Net-Ping-xxxx.tar.gz
+
+ rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm
+
=head1 AUTHORS
Current maintainer:
projects / p5sagit/p5-mst-13.2.git / blobdiff