package Net::Ping;
-# Current maintainer: colinm@cpan.org (Colin McMillen)
-#
-# Original author: mose@ccsn.edu (Russell Mosemann)
-#
-# Authors of the original pingecho():
-# karrer@bernina.ethz.ch (Andreas Karrer)
-# Paul.Marquess@btinternet.com (Paul Marquess)
-#
-# Copyright (c) 2001, Colin McMillen. All rights reserved. This
-# program is free software; you may redistribute it and/or modify it
-# under the same terms as Perl itself.
-use 5.005_64;
+# $Id: Ping.pm,v 1.33 2002/05/03 21:54:59 rob Exp $
+
+require 5.002;
require Exporter;
use strict;
-our(@ISA, @EXPORT, $VERSION, $def_timeout, $def_proto, $max_datasize);
+use vars qw(@ISA @EXPORT $VERSION
+ $def_timeout $def_proto $max_datasize $pingstring $hires);
use FileHandle;
use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET
inet_aton inet_ntoa sockaddr_in );
use Carp;
+use POSIX qw(ECONNREFUSED);
@ISA = qw(Exporter);
@EXPORT = qw(pingecho);
-$VERSION = 2.03;
+$VERSION = "2.17";
# Constants
$def_timeout = 5; # Default timeout to wait for a reply
-$def_proto = "udp"; # Default protocol to use for pinging
+$def_proto = "tcp"; # Default protocol to use for pinging
$max_datasize = 1024; # Maximum data bytes in a packet
+# The data we exchange with the server for the stream protocol
+$pingstring = "pingschwingping!\n";
+
+if ($^O =~ /Win32/i) {
+ # Hack to avoid this Win32 spewage:
+ # Your vendor has not defined POSIX macro ECONNREFUSED
+ *ECONNREFUSED = sub {10061;}; # "Unknown Error" Special Win32 Response?
+};
# Description: The pingecho() subroutine is provided for backward
# compatibility with the original Net::Ping. It accepts a host
sub pingecho
{
- my ($host, # Name or IP number of host to ping
- $timeout # Optional timeout in seconds
- ) = @_;
- my ($p); # A ping object
+ my ($host, # Name or IP number of host to ping
+ $timeout # Optional timeout in seconds
+ ) = @_;
+ my ($p); # A ping object
- $p = Net::Ping->new("tcp", $timeout);
- $p->ping($host); # Going out of scope closes the connection
+ $p = Net::Ping->new("tcp", $timeout);
+ $p->ping($host); # Going out of scope closes the connection
}
# Description: The new() method creates a new ping object. Optional
sub new
{
- my ($this,
- $proto, # Optional protocol to use for pinging
- $timeout, # Optional timeout in seconds
- $data_size # Optional additional bytes of data
- ) = @_;
- my $class = ref($this) || $this;
- my $self = {};
- my ($cnt, # Count through data bytes
- $min_datasize # Minimum data bytes required
- );
-
- bless($self, $class);
-
- $proto = $def_proto unless $proto; # Determine the protocol
- croak('Protocol for ping must be "icmp", "tcp", "udp", or "external"')
- unless $proto =~ m/^(tcp|udp|icmp|external)$/;
- $self->{"proto"} = $proto;
-
- $timeout = $def_timeout unless $timeout; # Determine the timeout
- croak("Default timeout for ping must be greater than 0 seconds")
- if $timeout <= 0;
- $self->{"timeout"} = $timeout;
-
- $min_datasize = ($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 $max_datasize bytes")
- if ($data_size < $min_datasize) || ($data_size > $max_datasize);
- $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte
- $self->{"data_size"} = $data_size;
-
- $self->{"data"} = ""; # Construct data bytes
- for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++)
- {
- $self->{"data"} .= chr($cnt % 256);
- }
+ my ($this,
+ $proto, # Optional protocol to use for pinging
+ $timeout, # Optional timeout in seconds
+ $data_size # Optional additional bytes of data
+ ) = @_;
+ my $class = ref($this) || $this;
+ my $self = {};
+ my ($cnt, # Count through data bytes
+ $min_datasize # Minimum data bytes required
+ );
+
+ bless($self, $class);
+
+ $proto = $def_proto unless $proto; # Determine the protocol
+ croak('Protocol for ping must be "icmp", "udp", "tcp", "stream", or "external"')
+ unless $proto =~ m/^(icmp|udp|tcp|stream|external)$/;
+ $self->{"proto"} = $proto;
+
+ $timeout = $def_timeout unless $timeout; # Determine the timeout
+ croak("Default timeout for ping must be greater than 0 seconds")
+ if $timeout <= 0;
+ $self->{"timeout"} = $timeout;
+
+ $min_datasize = ($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 $max_datasize bytes")
+ if ($data_size < $min_datasize) || ($data_size > $max_datasize);
+ $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte
+ $self->{"data_size"} = $data_size;
+
+ $self->{"data"} = ""; # Construct data bytes
+ for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++)
+ {
+ $self->{"data"} .= chr($cnt % 256);
+ }
- $self->{"seq"} = 0; # For counting packets
- if ($self->{"proto"} eq "udp") # Open a socket
- {
- $self->{"proto_num"} = (getprotobyname('udp'))[2] ||
- croak("Can't udp protocol by name");
- $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] ||
- croak("Can't get udp echo port by name");
- $self->{"fh"} = FileHandle->new();
- socket($self->{"fh"}, &PF_INET(), &SOCK_DGRAM(),
- $self->{"proto_num"}) ||
- croak("udp socket error - $!");
- }
- elsif ($self->{"proto"} eq "icmp")
- {
- croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS');
- $self->{"proto_num"} = (getprotobyname('icmp'))[2] ||
- croak("Can't get icmp protocol by name");
- $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid
- $self->{"fh"} = FileHandle->new();
- socket($self->{"fh"}, &PF_INET(), &SOCK_RAW(), $self->{"proto_num"}) ||
- croak("icmp socket error - $!");
- }
- elsif ($self->{"proto"} eq "tcp") # Just a file handle for now
- {
- $self->{"proto_num"} = (getprotobyname('tcp'))[2] ||
- croak("Can't get tcp protocol by name");
- $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] ||
- croak("Can't get tcp echo port by name");
- $self->{"fh"} = FileHandle->new();
- }
+ $self->{"local_addr"} = undef; # Don't bind by default
+
+ $self->{"seq"} = 0; # For counting packets
+ if ($self->{"proto"} eq "udp") # Open a socket
+ {
+ $self->{"proto_num"} = (getprotobyname('udp'))[2] ||
+ croak("Can't udp protocol by name");
+ $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] ||
+ croak("Can't get udp echo port by name");
+ $self->{"fh"} = FileHandle->new();
+ socket($self->{"fh"}, PF_INET, SOCK_DGRAM,
+ $self->{"proto_num"}) ||
+ croak("udp socket error - $!");
+ }
+ elsif ($self->{"proto"} eq "icmp")
+ {
+ croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS');
+ $self->{"proto_num"} = (getprotobyname('icmp'))[2] ||
+ croak("Can't get icmp protocol by name");
+ $self->{"pid"} = $$ & 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 - $!");
+ }
+ elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream")
+ {
+ $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");
+ $self->{"fh"} = FileHandle->new();
+ }
+
+ return($self);
+}
+
+# Description: Set the local IP address from which pings will be sent.
+# For ICMP and UDP pings, this calls bind() on the already-opened socket;
+# for TCP pings, just saves the address to be used when the socket is
+# opened. Returns non-zero if successful; croaks on error.
+sub bind
+{
+ my ($self,
+ $local_addr # Name or IP number of local interface
+ ) = @_;
+ my ($ip # Packed IP number of $local_addr
+ );
+
+ croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2;
+ croak("already bound") if defined($self->{"local_addr"}) &&
+ ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp");
+
+ $ip = inet_aton($local_addr);
+ croak("nonexistent local address $local_addr") unless defined($ip);
+ $self->{"local_addr"} = $ip; # Only used if proto is tcp
+
+ if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp")
+ {
+ CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) ||
+ croak("$self->{'proto'} bind error - $!");
+ }
+ elsif ($self->{"proto"} ne "tcp")
+ {
+ croak("Unknown protocol \"$self->{proto}\" in bind()");
+ }
+ return 1;
+}
- return($self);
+
+# Description: allows the module to use milliseconds as returned by
+# the Time::HiRes module
+
+$hires = 0;
+sub hires
+{
+ my $self = shift;
+ $hires = 1 unless defined
+ ($hires = ((defined $self) && (ref $self)) ? shift() : $self);
+ require Time::HiRes if $hires;
+}
+
+sub time
+{
+ return $hires ? Time::HiRes::time() : CORE::time();
}
# Description: Ping a host name or IP number with an optional timeout.
# First lookup the host, and return undef if it is not found. Otherwise
-# perform the specific ping method based on the protocol. Return the
+# perform the specific ping method based on the protocol. Return the
# result of the ping.
sub ping
{
- my ($self,
- $host, # Name or IP number of host to ping
- $timeout # Seconds after which ping times out
- ) = @_;
- my ($ip, # Packed IP number of $host
- $ret # The return value
- );
-
- croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3;
- $timeout = $self->{"timeout"} unless $timeout;
- croak("Timeout must be greater than 0 seconds") if $timeout <= 0;
-
- $ip = inet_aton($host);
- return(undef) unless defined($ip); # Does host exist?
-
- # Dispatch to the appropriate routine.
- return $self->ping_external($ip, $timeout) if $self->{"proto"} eq "external";
- return $self->ping_udp($ip, $timeout) if $self->{"proto"} eq "udp";
- return $self->ping_icmp($ip, $timeout) if $self->{"proto"} eq "icmp";
- return $self->ping_tcp($ip, $timeout) if $self->{"proto"} eq "tcp";
-
+ my ($self,
+ $host, # Name or IP number of host to ping
+ $timeout, # Seconds after which ping times out
+ ) = @_;
+ my ($ip, # Packed IP number of $host
+ $ret, # The return value
+ $ping_time, # When ping began
+ );
+
+ croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3;
+ $timeout = $self->{"timeout"} unless $timeout;
+ croak("Timeout must be greater than 0 seconds") if $timeout <= 0;
+
+ $ip = inet_aton($host);
+ return(undef) unless defined($ip); # Does host exist?
+
+ # Dispatch to the appropriate routine.
+ $ping_time = &time();
+ if ($self->{"proto"} eq "external") {
+ $ret = $self->ping_external($ip, $timeout);
+ }
+ elsif ($self->{"proto"} eq "udp") {
+ $ret = $self->ping_udp($ip, $timeout);
+ }
+ elsif ($self->{"proto"} eq "icmp") {
+ $ret = $self->ping_icmp($ip, $timeout);
+ }
+ elsif ($self->{"proto"} eq "tcp") {
+ $ret = $self->ping_tcp($ip, $timeout);
+ }
+ elsif ($self->{"proto"} eq "stream") {
+ $ret = $self->ping_stream($ip, $timeout);
+ } else {
croak("Unknown protocol \"$self->{proto}\" in ping()");
+ }
+
+ return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret;
}
# Uses Net::Ping::External to do an external ping.
$timeout # Seconds after which ping times out
) = @_;
- eval { require Net::Ping::External; };
- croak('Protocol "external" not supported on your system: Net::Ping::External not found') if $@;
+ eval { require Net::Ping::External; }
+ or croak('Protocol "external" not supported on your system: Net::Ping::External not found');
return Net::Ping::External::ping(ip => $ip, timeout => $timeout);
}
+use constant ICMP_ECHOREPLY => 0; # ICMP packet types
+use constant ICMP_ECHO => 8;
+use constant ICMP_STRUCT => "C2 S3 A"; # Structure of a minimal ICMP packet
+use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY
+use constant ICMP_FLAGS => 0; # No special flags for send or recv
+use constant ICMP_PORT => 0; # No port with ICMP
+
sub ping_icmp
{
- my ($self,
- $ip, # Packed IP number of the host
- $timeout # Seconds after which ping times out
- ) = @_;
-
- my $ICMP_ECHOREPLY = 0; # ICMP packet types
- my $ICMP_ECHO = 8;
- my $icmp_struct = "C2 S3 A"; # Structure of a minimal ICMP packet
- my $subcode = 0; # No ICMP subcode for ECHO and ECHOREPLY
- my $flags = 0; # No special flags when opening a socket
- my $port = 0; # No port with ICMP
-
- my ($saddr, # sockaddr_in with port and ip
- $checksum, # Checksum of ICMP packet
- $msg, # ICMP packet to send
- $len_msg, # Length of $msg
- $rbits, # Read bits, filehandles for reading
- $nfound, # Number of ready filehandles found
- $finish_time, # Time ping should be finished
- $done, # set to 1 when we are done
- $ret, # Return value
- $recv_msg, # Received message including IP header
- $from_saddr, # sockaddr_in of sender
- $from_port, # Port packet was sent from
- $from_ip, # Packed IP of sender
- $from_type, # ICMP type
- $from_subcode, # ICMP subcode
- $from_chk, # ICMP packet checksum
- $from_pid, # ICMP packet id
- $from_seq, # ICMP packet sequence
- $from_msg # ICMP message
- );
-
- $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence
- $checksum = 0; # No checksum for starters
- $msg = pack($icmp_struct . $self->{"data_size"}, $ICMP_ECHO, $subcode,
- $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"});
- $checksum = Net::Ping->checksum($msg);
- $msg = pack($icmp_struct . $self->{"data_size"}, $ICMP_ECHO, $subcode,
- $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"});
- $len_msg = length($msg);
- $saddr = sockaddr_in($port, $ip);
- send($self->{"fh"}, $msg, $flags, $saddr); # Send the message
-
- $rbits = "";
- vec($rbits, $self->{"fh"}->fileno(), 1) = 1;
- $ret = 0;
- $done = 0;
- $finish_time = time() + $timeout; # Must be done by this time
- while (!$done && $timeout > 0) # Keep trying if we have time
+ my ($self,
+ $ip, # Packed IP number of the host
+ $timeout # Seconds after which ping times out
+ ) = @_;
+
+ my ($saddr, # sockaddr_in with port and ip
+ $checksum, # Checksum of ICMP packet
+ $msg, # ICMP packet to send
+ $len_msg, # Length of $msg
+ $rbits, # Read bits, filehandles for reading
+ $nfound, # Number of ready filehandles found
+ $finish_time, # Time ping should be finished
+ $done, # set to 1 when we are done
+ $ret, # Return value
+ $recv_msg, # Received message including IP header
+ $from_saddr, # sockaddr_in of sender
+ $from_port, # Port packet was sent from
+ $from_ip, # Packed IP of sender
+ $from_type, # ICMP type
+ $from_subcode, # ICMP subcode
+ $from_chk, # ICMP packet checksum
+ $from_pid, # ICMP packet id
+ $from_seq, # ICMP packet sequence
+ $from_msg # ICMP message
+ );
+
+ $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence
+ $checksum = 0; # No checksum for starters
+ $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE,
+ $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"});
+ $checksum = Net::Ping->checksum($msg);
+ $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE,
+ $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"});
+ $len_msg = length($msg);
+ $saddr = sockaddr_in(ICMP_PORT, $ip);
+ send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message
+
+ $rbits = "";
+ vec($rbits, $self->{"fh"}->fileno(), 1) = 1;
+ $ret = 0;
+ $done = 0;
+ $finish_time = &time() + $timeout; # Must be done by this time
+ while (!$done && $timeout > 0) # Keep trying if we have time
+ {
+ $nfound = select($rbits, undef, undef, $timeout); # Wait for packet
+ $timeout = $finish_time - &time(); # Get remaining time
+ if (!defined($nfound)) # Hmm, a strange error
{
- $nfound = select($rbits, undef, undef, $timeout); # Wait for packet
- $timeout = $finish_time - time(); # Get remaining time
- if (!defined($nfound)) # Hmm, a strange error
- {
- $ret = undef;
- $done = 1;
- }
- elsif ($nfound) # Got a packet from somewhere
- {
- $recv_msg = "";
- $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, $flags);
- ($from_port, $from_ip) = sockaddr_in($from_saddr);
- ($from_type, $from_subcode, $from_chk,
- $from_pid, $from_seq, $from_msg) =
- unpack($icmp_struct . $self->{"data_size"},
- substr($recv_msg, length($recv_msg) - $len_msg,
- $len_msg));
- if (($from_type == $ICMP_ECHOREPLY) &&
- ($from_ip eq $ip) &&
- ($from_pid == $self->{"pid"}) && # Does the packet check out?
- ($from_seq == $self->{"seq"}))
- {
- $ret = 1; # It's a winner
- $done = 1;
- }
- }
- else # Oops, timed out
- {
- $done = 1;
- }
+ $ret = undef;
+ $done = 1;
}
- return($ret)
+ elsif ($nfound) # Got a packet from somewhere
+ {
+ $recv_msg = "";
+ $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS);
+ ($from_port, $from_ip) = sockaddr_in($from_saddr);
+ ($from_type, $from_subcode, $from_chk,
+ $from_pid, $from_seq, $from_msg) =
+ unpack(ICMP_STRUCT . $self->{"data_size"},
+ substr($recv_msg, length($recv_msg) - $len_msg,
+ $len_msg));
+ if (($from_type == ICMP_ECHOREPLY) &&
+ ($from_ip eq $ip) &&
+ ($from_pid == $self->{"pid"}) && # Does the packet check out?
+ ($from_seq == $self->{"seq"}))
+ {
+ $ret = 1; # It's a winner
+ $done = 1;
+ }
+ }
+ else # Oops, timed out
+ {
+ $done = 1;
+ }
+ }
+ return $ret;
}
# Description: Do a checksum on the message. Basically sum all of
sub checksum
{
- my ($class,
- $msg # The message to checksum
- ) = @_;
- my ($len_msg, # Length of the message
- $num_short, # The number of short words in the message
- $short, # One short word
- $chk # The checksum
- );
-
- $len_msg = length($msg);
- $num_short = int($len_msg / 2);
- $chk = 0;
- foreach $short (unpack("S$num_short", $msg))
- {
- $chk += $short;
- } # Add the odd byte in
- $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2;
- $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low
- return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement
+ my ($class,
+ $msg # The message to checksum
+ ) = @_;
+ my ($len_msg, # Length of the message
+ $num_short, # The number of short words in the message
+ $short, # One short word
+ $chk # The checksum
+ );
+
+ $len_msg = length($msg);
+ $num_short = int($len_msg / 2);
+ $chk = 0;
+ foreach $short (unpack("S$num_short", $msg))
+ {
+ $chk += $short;
+ } # Add the odd byte in
+ $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2;
+ $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low
+ return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement
}
+
# Description: Perform a tcp echo ping. Since a tcp connection is
# host specific, we have to open and close each connection here. We
# can't just leave a socket open. Because of the robust nature of
# tcp, it will take a while before it gives up trying to establish a
# connection. Therefore, we use select() on a non-blocking socket to
-# check against our timeout. No data bytes are actually
+# check against our timeout. No data bytes are actually
# sent since the successful establishment of a connection is proof
# enough of the reachability of the remote host. Also, tcp is
# expensive and doesn't need our help to add to the overhead.
my ($self,
$ip, # Packed IP number of the host
$timeout # Seconds after which ping times out
- ) = @_;
- my ($saddr, # sockaddr_in with port and ip
- $rin, # Used in select()
- $ret # The return value
- );
+ ) = @_;
+ my ($ret # The return value
+ );
+
+ $@ = ""; $! = 0;
+ $ret = $self -> tcp_connect( $ip, $timeout);
+ $ret = 1 if $! == ECONNREFUSED; # Connection refused
+ $self->{"fh"}->close();
+ return $ret;
+}
- socket($self->{"fh"}, &PF_INET(), &SOCK_STREAM(), $self->{"proto_num"}) ||
- croak("tcp socket error - $!");
+sub tcp_connect
+{
+ my ($self,
+ $ip, # Packed IP number of the host
+ $timeout # Seconds after which connect times out
+ ) = @_;
+ my ($saddr); # Packed IP and Port
$saddr = sockaddr_in($self->{"port_num"}, $ip);
- $ret = 0; # Default to unreachable
+ my $ret = 0; # Default to unreachable
- # Buggy Winsock API doesn't allow us to use non-blocking connect()
- # calls. Hence, if our OS is Windows, we need to create a new process
- # to run a blocking connect attempt, and kill it after the timeout has
- # passed.
- if ($^O =~ /win32/i)
- {
- my ($child, $ret, $pid, $time);
- my $host = inet_ntoa($ip);
+ my $do_socket = sub {
+ socket($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 - $!");
+ }
+ };
+ my $do_connect = sub {
+ eval {
+ die $! unless connect($self->{"fh"}, $saddr);
+ $self->{"ip"} = $ip;
+ $ret = 1;
+ };
+ $ret;
+ };
+
+ if ($^O =~ /Win32/i) {
+
+ # Buggy Winsock API doesn't allow us to use alarm() calls.
+ # Hence, if our OS is Windows, we need to create a separate
+ # process to do the blocking connect attempt.
+
+ $| = 1; # Clear buffer prior to fork to prevent duplicate flushing.
+ my $pid = fork;
+ if (!$pid) {
+ if (!defined $pid) {
+ # Fork did not work
+ warn "Win32 Fork error: $!";
+ return 0;
+ }
+ &{ $do_socket }();
+
+ # Try a slow blocking connect() call
+ # and report the status to the pipe.
+ if ( &{ $do_connect }() ) {
+ $self->{"fh"}->close();
+ # No error
+ exit 0;
+ } else {
+ # Pass the error status to the parent
+ exit $!;
+ }
+ }
- # The code we will be executing in our new process.
- my $code = '"use Net::Ping; $p = Net::Ping->new(\'tcp\'); ';
- $code .= 'exit($p->_ping_tcp_win(' . $host . '))"';
+ &{ $do_socket }();
+
+ 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);
+ $! = $? >> 8;
+ $@ = $!;
+ select(undef, undef, undef, 0.1);
+ } while &time() < $patience && $child != $pid;
+
+ if ($child == $pid) {
+ # Since she finished within the timeout,
+ # it is probably safe for me to try it too
+ &{ $do_connect }();
+ } else {
+ # Time must have run out.
+ $@ = "Timed out!";
+ # Put that choking client out of its misery
+ kill "KILL", $pid;
+ # Clean off the zombie
+ waitpid($pid, 0);
+ $ret = 0;
+ }
+ } else { # Win32
+ # Otherwise don't waste the resources to fork
- # Call the process.
- $pid = system(1, "perl", "-e", $code);
+ &{ $do_socket }();
- # Import the POSIX version of <sys/wait.h>
- require POSIX;
- import POSIX qw(:sys_wait_h);
+ $SIG{'ALRM'} = sub { die "Timed out!"; };
+ alarm($timeout); # Interrupt connect() if we have to
- # Get the current time; will be used to tell if we've timed out.
- $time = time;
+ &{ $do_connect }();
+ alarm(0);
+ }
- # Wait for the child to return or for the timeout to expire.
- do {
- $child = waitpid($pid, &WNOHANG);
- $ret = $?;
- } until time > ($time + $timeout) or $child;
+ return $ret;
+}
- # Return an appropriate value; 0 if the child didn't return,
- # the return value of the child otherwise.
- return $ret >> 8 if $child;
+# This writes the given string to the socket and then reads it
+# back. It returns 1 on success, 0 on failure.
+sub tcp_echo
+{
+ my $self = shift;
+ my $timeout = shift;
+ my $pingstring = shift;
+
+ my $ret = undef;
+ my $time = &time();
+ my $wrstr = $pingstring;
+ my $rdstr = "";
+
+ eval <<'EOM';
+ do {
+ my $rin = "";
+ vec($rin, $self->{"fh"}->fileno(), 1) = 1;
+
+ my $rout = undef;
+ if($wrstr) {
+ $rout = "";
+ vec($rout, $self->{"fh"}->fileno(), 1) = 1;
+ }
+
+ if(select($rin, $rout, undef, ($time + $timeout) - &time())) {
+
+ if($rout && vec($rout,$self->{"fh"}->fileno(),1)) {
+ my $num = syswrite($self->{"fh"}, $wrstr);
+ if($num) {
+ # If it was a partial write, update and try again.
+ $wrstr = substr($wrstr,$num);
+ } else {
+ # There was an error.
+ $ret = 0;
+ }
+ }
- kill $pid;
- return 0;
- }
+ if(vec($rin,$self->{"fh"}->fileno(),1)) {
+ my $reply;
+ if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) {
+ $rdstr .= $reply;
+ $ret = 1 if $rdstr eq $pingstring;
+ } else {
+ # There was an error.
+ $ret = 0;
+ }
+ }
- # If our OS isn't Windows, do this stuff instead...
- else
- {
- # Try a non-blocking TCP connect to the remote echo port.
- # Our call to select() below will stop after the timeout has
- # passed or set the return value to true if the connection
- # succeeds in time.
- $self->{"fh"}->blocking(0);
- connect($self->{"fh"}, $saddr);
-
- $rin = "";
- vec($rin, fileno($self->{"fh"}), 1) = 1;
- $ret = 1 if select($rin, undef, undef, $timeout);
-
- # Close our filehandle, restore it to its default state (i.e. blocking),
- # and return our result.
- $self->{"fh"}->blocking(1);
- $self->{"fh"}->close();
- }
- return($ret);
+ }
+ } until &time() > ($time + $timeout) || defined($ret);
+EOM
+
+ return $ret;
}
-# Warning: this method may generate false positives.
-# It is meant to be a private method and should only
-# be invoked by ping_tcp() if $^O =~ /win32/i.
-sub _ping_tcp_win
-{
- my ($self,
- $ip, # Packed IP number of the host
- ) = @_;
- my ($saddr, # sockaddr_in with port and ip
- $ret # The return value
- );
- socket($self->{"fh"}, &PF_INET(), &SOCK_STREAM(), $self->{"proto_num"}) ||
- croak("tcp socket error - $!");
- $saddr = sockaddr_in($self->{"port_num"}, $ip);
- $ret = 0; # Default to unreachable
+# Description: Perform a stream ping. If the tcp connection isn't
+# already open, it opens it. It then sends some data and waits for
+# a reply. It leaves the stream open on exit.
- eval { $ret = connect($self->{"fh"}, $saddr) };
+sub ping_stream
+{
+ my ($self,
+ $ip, # Packed IP number of the host
+ $timeout # Seconds after which ping times out
+ ) = @_;
- # If the remote host exists but returns "Connection refused",
- # the call to connect() sets $! to "Unknown error". So, we
- # assume that an "Unknown error" actually means the host is
- # alive. This assumption may occassionally give false positives.
- $ret = 1 if $! =~ /Unknown error/i;
+ # Open the stream if it's not already open
+ if(!defined $self->{"fh"}->fileno()) {
+ $self->tcp_connect($ip, $timeout) or return 0;
+ }
- $self->{"fh"}->close();
- return $ret;
+ croak "tried to switch servers while stream pinging"
+ if $self->{"ip"} ne $ip;
+
+ return $self->tcp_echo($timeout, $pingstring);
}
+# Description: opens the stream. You would do this if you want to
+# separate the overhead of opening the stream from the first ping.
+
+sub open
+{
+ my ($self,
+ $host, # Host or IP address
+ $timeout # Seconds after which open times out
+ ) = @_;
+
+ my ($ip); # Packed IP number of the host
+ $ip = inet_aton($host);
+ $timeout = $self->{"timeout"} unless $timeout;
+
+ if($self->{"proto"} eq "stream") {
+ if(defined($self->{"fh"}->fileno())) {
+ croak("socket is already open");
+ } else {
+ $self->tcp_connect($ip, $timeout);
+ }
+ }
+}
+
+
# Description: Perform a udp echo ping. Construct a message of
# at least the one-byte sequence number and any additional data bytes.
# Send the message out and wait for a message to come back. If we
# done. Otherwise go back and wait for the message until we run out
# of time. Return the result of our efforts.
+use constant UDP_FLAGS => 0; # Nothing special on send or recv
+
sub ping_udp
{
- my ($self,
- $ip, # Packed IP number of the host
- $timeout # Seconds after which ping times out
- ) = @_;
-
- my $flags = 0; # Nothing special on open
-
- my ($saddr, # sockaddr_in with port and ip
- $ret, # The return value
- $msg, # Message to be echoed
- $finish_time, # Time ping should be finished
- $done, # Set to 1 when we are done pinging
- $rbits, # Read bits, filehandles for reading
- $nfound, # Number of ready filehandles found
- $from_saddr, # sockaddr_in of sender
- $from_msg, # Characters echoed by $host
- $from_port, # Port message was echoed from
- $from_ip # Packed IP number of sender
- );
-
- $saddr = sockaddr_in($self->{"port_num"}, $ip);
- $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence
- $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any
- send($self->{"fh"}, $msg, $flags, $saddr); # Send it
-
- $rbits = "";
- vec($rbits, $self->{"fh"}->fileno(), 1) = 1;
- $ret = 0; # Default to unreachable
- $done = 0;
- $finish_time = time() + $timeout; # Ping needs to be done by then
- while (!$done && $timeout > 0)
- {
- $nfound = select($rbits, undef, undef, $timeout); # Wait for response
- $timeout = $finish_time - time(); # Get remaining time
+ my ($self,
+ $ip, # Packed IP number of the host
+ $timeout # Seconds after which ping times out
+ ) = @_;
- if (!defined($nfound)) # Hmm, a strange error
- {
- $ret = undef;
- $done = 1;
- }
- elsif ($nfound) # A packet is waiting
- {
- $from_msg = "";
- $from_saddr = recv($self->{"fh"}, $from_msg, 1500, $flags)
- or last; # For example an unreachable host will make recv() fail.
- ($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))
- {
- $ret = 1; # It's a winner
- $done = 1;
- }
- }
- else # Oops, timed out
- {
- $done = 1;
- }
+ my ($saddr, # sockaddr_in with port and ip
+ $ret, # The return value
+ $msg, # Message to be echoed
+ $finish_time, # Time ping should be finished
+ $done, # Set to 1 when we are done pinging
+ $rbits, # Read bits, filehandles for reading
+ $nfound, # Number of ready filehandles found
+ $from_saddr, # sockaddr_in of sender
+ $from_msg, # Characters echoed by $host
+ $from_port, # Port message was echoed from
+ $from_ip # Packed IP number of sender
+ );
+
+ $saddr = sockaddr_in($self->{"port_num"}, $ip);
+ $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence
+ $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any
+ send($self->{"fh"}, $msg, UDP_FLAGS, $saddr); # Send it
+
+ $rbits = "";
+ vec($rbits, $self->{"fh"}->fileno(), 1) = 1;
+ $ret = 0; # Default to unreachable
+ $done = 0;
+ $finish_time = &time() + $timeout; # Ping needs to be done by then
+ while (!$done && $timeout > 0)
+ {
+ $nfound = select($rbits, undef, undef, $timeout); # Wait for response
+ $timeout = $finish_time - &time(); # Get remaining time
+
+ if (!defined($nfound)) # Hmm, a strange error
+ {
+ $ret = undef;
+ $done = 1;
+ }
+ elsif ($nfound) # A packet is waiting
+ {
+ $from_msg = "";
+ $from_saddr = recv($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))
+ {
+ $ret = 1; # It's a winner
+ $done = 1;
+ }
+ }
+ else # Oops, timed out
+ {
+ $done = 1;
}
- return($ret);
-}
+ }
+ return $ret;
+}
# Description: Close the connection unless we are using the tcp
# protocol, since it will already be closed.
sub close
{
- my ($self) = @_;
+ my ($self) = @_;
- $self->{"fh"}->close() unless $self->{"proto"} eq "tcp";
+ $self->{"fh"}->close() unless $self->{"proto"} eq "tcp";
}
Net::Ping - check a remote host for reachability
+$Id: Ping.pm,v 1.33 2002/05/03 21:54:59 rob Exp $
+
=head1 SYNOPSIS
use Net::Ping;
$p->close();
$p = Net::Ping->new("icmp");
+ $p->bind($my_addr); # Specify source interface of pings
foreach $host (@host_array)
{
print "$host is ";
sleep(1);
}
$p->close();
-
+
$p = Net::Ping->new("tcp", 2);
+ # Try connecting to the www port instead of the echo port
+ $p->{port_num} = getservbyname("http", "tcp");
while ($stop_time > time())
{
print "$host not reachable ", scalar(localtime()), "\n"
sleep(300);
}
undef($p);
-
+
+ # High precision syntax (requires Time::HiRes)
+ $p = Net::Ping->new();
+ $p->hires();
+ ($ret, $duration, $ip) = $p->ping($host, 5.5);
+ printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration)
+ if $ret;
+ $p->close();
+
# For backward compatibility
print "$host is alive.\n" if pingecho($host);
received from the remote host and the received packet contains the
same data as the packet that was sent, the remote host is considered
reachable. This protocol does not require any special privileges.
-
-It should be borne in mind that, for both udp ping, a host
+It should be borne in mind that, for a udp ping, a host
will be reported as unreachable if it is not running the
-appropriate echo service. For Unix-like systems see L<inetd(8)> for
-more information.
+appropriate echo service. For Unix-like systems see L<inetd(8)>
+for more information.
If the "icmp" protocol is specified, the ping() method sends an icmp
echo message to the remote host, which is what the UNIX ping program
otherwise. The maximum number of data bytes that can be specified is
1024.
+=item $p->hires( { 0 | 1 } );
+
+Causes this module to use Time::HiRes module, allowing milliseconds
+to be returned by subsequent calls to ping().
+
+=item $p->bind($local_addr);
+
+Sets the source address from which pings will be sent. This must be
+the address of one of the interfaces on the local host. $local_addr
+may be specified as a hostname or as a text IP address such as
+"192.168.1.1".
+
+If the protocol is set to "tcp", this method may be called any
+number of times, and each call to the ping() method (below) will use
+the most recent $local_addr. If the protocol is "icmp" or "udp",
+then bind() must be called at most once per object, and (if it is
+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. If the hostname cannot be found or
-there is a problem with the IP number, undef is returned. Otherwise,
-1 is returned if the host is reachable and 0 if it is not. For all
-practical purposes, undef and 0 and can be treated as the same case.
+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
+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
+first ping. If you don't call C<open()>, the connection is
+automatically opened the first time C<ping()> is called.
+This call simply does nothing if you are using any protocol other
+than stream.
=item $p->close();
=back
+=head1 WARNING
+
+pingecho() or a ping object with the tcp protocol use alarm() to
+implement the timeout. So, don't use alarm() in your program while
+you are using pingecho() or a ping object with the tcp protocol. The
+udp and icmp protocols do not use alarm() to implement the timeout.
+
=head1 NOTES
There will be less network overhead (and some efficiency in your
avoid flooding your network with packets.
The icmp protocol requires that the program be run as root or that it
-be setuid to root. The tcp and udp protocols do not require special
-privileges, but not all network devices implement the echo protocol
-for tcp or udp.
+be setuid to root. The other protocols do not require special
+privileges, but not all network devices implement tcp or udp echo.
Local hosts should normally respond to pings within milliseconds.
However, on a very congested network it may take up to 3 seconds or
host is not reachable (which is almost the truth).
Reachability doesn't necessarily mean that the remote host is actually
-functioning beyond its ability to echo packets.
+functioning beyond its ability to echo packets. tcp is slightly better
+at indicating the health of a system than icmp because it uses more
+of the networking stack to respond.
Because of a lack of anything better, this module uses its own
routines to pack and unpack ICMP packets. It would be better for a
separate module to be written which understands all of the different
kinds of ICMP packets.
+=head1 AUTHORS
+
+ Current maintainer:
+ bbb@cpan.org (Rob Brown)
+
+ External protocol:
+ colinm@cpan.org (Colin McMillen)
+
+ Stream protocol:
+ bronson@trestle.com (Scott Bronson)
+
+ Original pingecho():
+ karrer@bernina.ethz.ch (Andreas Karrer)
+ pmarquess@bfsec.bt.co.uk (Paul Marquess)
+
+ Original Net::Ping author:
+ mose@ns.ccsn.edu (Russell Mosemann)
+
+=head1 COPYRIGHT
+
+Copyright (c) 2002, Rob Brown. All rights reserved.
+
+Copyright (c) 2001, Colin McMillen. All rights reserved.
+
+This program is free software; you may redistribute it and/or
+modify it under the same terms as Perl itself.
+
=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff