package Net::Ping;
-# $Id: Ping.pm,v 1.34 2002/05/06 17:37:54 rob Exp $
+# $Id: Ping.pm,v 1.33 2002/10/19 05:02:43 rob Exp $
require 5.002;
require Exporter;
use strict;
use vars qw(@ISA @EXPORT $VERSION
- $def_timeout $def_proto $max_datasize $pingstring $hires);
-use FileHandle;
-use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET
+ $def_timeout $def_proto $max_datasize $pingstring $hires $source_verify $syn_forking);
+use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK );
+use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET
inet_aton inet_ntoa sockaddr_in );
+use POSIX qw( ECONNREFUSED EINPROGRESS WNOHANG );
+use FileHandle;
use Carp;
-use POSIX qw(ECONNREFUSED);
@ISA = qw(Exporter);
@EXPORT = qw(pingecho);
-$VERSION = "2.18";
+$VERSION = "2.23";
# Constants
$max_datasize = 1024; # Maximum data bytes in a packet
# The data we exchange with the server for the stream protocol
$pingstring = "pingschwingping!\n";
+$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();
+ } 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);
}
}
+# Description: Allow UDP source endpoint comparision to be
+# skipped for those remote interfaces that do
+# not response from the same endpoint.
+
+sub source_verify
+{
+ my $self = shift;
+ $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
# the Time::HiRes module
}
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;
$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 (($from_ip eq $ip) && # Does the packet check out?
- ($from_port == $self->{"port_num"}) &&
- ($from_msg eq $msg))
+ if (!$source_verify ||
+ (($from_ip eq $ip) && # Does the packet check out?
+ ($from_port == $self->{"port_num"}) &&
+ ($from_msg eq $msg)))
{
$ret = 1; # It's a winner
$done = 1;
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
+ if (my $flags = fcntl($fh, F_GETFL, 0)) {
+ fcntl($fh, F_SETFL, $flags | O_NONBLOCK);
+ } 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.
+ # Can this ever really happen?
+ }
+ else {
+ # Error occurred connecting.
+ # Hopefully the connection is just still in progress.
+ if ($! != EINPROGRESS) {
+ # If not, then it really is something bad.
+ $self->{"bad"}->{$host} = $!;
+ return undef;
+ }
+ }
+
+ 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}) {
+ 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 <= .01;
+ if (my $nfound = select(undef, (my $wout=$wbits), undef, $timeout)) {
+ # Done waiting for one of the ACKs
+ my $fd = 0;
+ # Determine which one
+ while (length $wout &&
+ !vec($wout, $fd, 1)) {
+ $fd++;
+ }
+ if (my $entry = $self->{"syn"}->{$fd}) {
+ if (getpeername($entry->[2])) {
+ # Connection established to remote host
+ delete $self->{"syn"}->{$fd};
+ vec($self->{"wbits"}, $fd, 1) = 0;
+ return wantarray ?
+ ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1]))
+ : $entry->[0];
+ } else {
+ # TCP ACK will never come from this host
+ # because there was an error connecting.
+
+ # Wipe it from future scanning.
+ delete $self->{"syn"}->{$fd};
+ vec($self->{"wbits"}, $fd, 1) = 0;
+ vec($wbits, $fd, 1) = 0;
+
+ # 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"} &&
+ $! == ECONNREFUSED) {
+ # "Connection refused" means reachable
+ return wantarray ?
+ ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1]))
+ : $entry->[0];
+ }
+ # Try another socket...
+ }
+ } else {
+ warn "Corrupted SYN entry: unknown fd [$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 = shift;
+ my $stop_time = $self->{"stop_time"};
+ if (my $host = shift) {
+ # Host passed as arg
+ warn "Cannot specify host for ack on win32\n";
+ }
+
+ 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();
+ } else {
+ # No hosts left to wait for
+ $timeout = 0;
+ }
+
+ if ($timeout > 0) {
+ if (my $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"} &&
+ $how == ECONNREFUSED)) { # "Connection refused" means reachable
+ return ($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?";
+ }
+ } elsif (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 1.34 2002/05/06 17:37:54 rob Exp $
+$Id: Ping.pm,v 1.33 2002/10/19 05:02:43 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
to be returned by subsequent calls to ping().
+This is disabled by default.
+
=item $p->bind($local_addr);
Sets the source address from which pings will be sent. This must be
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:
https://perl5.git.perl.org / perl5.git / blobdiff