Mass Deface
10061, # "Unknown Error" Special Win32 Response?
ENOTCONN => 10057,
ECONNRESET => 10054,
EINPROGRESS => 10036,
EWOULDBLOCK => 10035,
);
while (my $name = shift @pairs) {
my $value = shift @pairs;
# When defined, these all are non-zero
unless (eval $name) {
no strict 'refs';
*{$name} = defined prototype \&{$name} ? sub () {$value} : sub {$value};
}
}
# $syn_forking = 1; # XXX possibly useful in < Win2K ?
};
# h2ph "asm/socket.h"
# require "asm/socket.ph";
sub SO_BINDTODEVICE {25;}
# Description: The pingecho() subroutine is provided for backward
# compatibility with the original Net::Ping. It accepts a host
# name/IP and an optional timeout in seconds. Create a tcp ping
# object and try pinging the host. The result of the ping is returned.
sub pingecho
{
my ($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
}
# Description: The new() method creates a new ping object. Optional
# parameters may be specified for the protocol to use, the timeout in
# seconds and the size in bytes of additional data which should be
# included in the packet.
# After the optional parameters are checked, the data is constructed
# and a socket is opened if appropriate. The object is returned.
sub new
{
my ($this,
$proto, # Optional protocol to use for pinging
$timeout, # Optional timeout in seconds
$data_size, # Optional additional bytes of data
$device, # Optional device to use
$tos, # Optional ToS to set
) = @_;
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", "syn", "stream", or "external"')
unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/;
$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;
$self->{"device"} = $device;
$self->{"tos"} = $tos;
$min_datasize = ($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->{"local_addr"} = undef; # Don't bind by default
$self->{"retrans"} = $def_factor; # Default exponential backoff rate
$self->{"econnrefused"} = undef; # Default Connection refused behavior
$self->{"seq"} = 0; # For counting packets
if ($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 - $!");
if ($self->{'device'}) {
setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
or croak "error binding to device $self->{'device'} $!";
}
if ($self->{'tos'}) {
setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'}))
or croak "error configuring tos to $self->{'tos'} $!";
}
}
elsif ($self->{"proto"} eq "icmp")
{
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'} $!";
}
if ($self->{'tos'}) {
setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'}))
or croak "error configuring tos to $self->{'tos'} $!";
}
}
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();
}
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);
}
# 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") && ($self->{"proto"} ne "syn"))
{
croak("Unknown protocol \"$self->{proto}\" in bind()");
}
return 1;
}
# Description: A select() wrapper that compensates for platform
# peculiarities.
sub mselect
{
if ($_[3] > 0 and $^O eq 'MSWin32') {
# On windows, select() doesn't process the message loop,
# but sleep() will, allowing alarm() to interrupt the latter.
# So we chop up the timeout into smaller pieces and interleave
# select() and sleep() calls.
my $t = $_[3];
my $gran = 0.5; # polling granularity in seconds
my @args = @_;
while (1) {
$gran = $t if $gran > $t;
my $nfound = select($_[0], $_[1], $_[2], $gran);
undef $nfound if $nfound == -1;
$t -= $gran;
return $nfound if $nfound or !defined($nfound) or $t <= 0;
sleep(0);
($_[0], $_[1], $_[2]) = @args;
}
}
else {
my $nfound = select($_[0], $_[1], $_[2], $_[3]);
undef $nfound if $nfound == -1;
return $nfound;
}
}
# Description: Allow UDP source endpoint comparison 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 connect
# behavior should enforce remote service
# availability as well as reachability.
sub service_check
{
my $self = shift;
$self->{"econnrefused"} = 1 unless defined
($self->{"econnrefused"} = shift());
}
sub tcp_service_check
{
service_check(@_);
}
# Description: Set exponential backoff for retransmission.
# Should be > 1 to retain exponential properties.
# If set to 0, retransmissions are disabled.
sub retrans
{
my $self = shift;
$self->{"retrans"} = shift;
}
# 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: Sets or clears the O_NONBLOCK flag on a file handle.
sub socket_blocking_mode
{
my ($self,
$fh, # the file handle whose flags are to be modified
$block) = @_; # if true then set the blocking
# mode (clear O_NONBLOCK), otherwise
# set the non-blocking mode (set O_NONBLOCK)
my $flags;
if ($^O eq 'MSWin32' || $^O eq 'VMS') {
# FIONBIO enables non-blocking sockets on windows and vms.
# FIONBIO is (0x80000000|(4<<16)|(ord('f')<<8)|126), as per winsock.h, ioctl.h
my $f = 0x8004667e;
my $v = pack("L", $block ? 0 : 1);
ioctl($fh, $f, $v) or croak("ioctl failed: $!");
return;
}
if ($flags = fcntl($fh, F_GETFL, 0)) {
$flags = $block ? ($flags & ~O_NONBLOCK) : ($flags | O_NONBLOCK);
if (!fcntl($fh, F_SETFL, $flags)) {
croak("fcntl F_SETFL: $!");
}
} else {
croak("fcntl F_GETFL: $!");
}
}
# 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
# 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
$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 () 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);
}
elsif ($self->{"proto"} eq "syn") {
$ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$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.
sub ping_external {
my ($self,
$ip, # Packed IP number of the host
$timeout # Seconds after which ping times out
) = @_;
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_UNREACHABLE => 3; # ICMP packet types
use constant ICMP_ECHO => 8;
use constant ICMP_STRUCT => "C2 n3 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 ($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);
$self->{"from_ip"} = undef;
$self->{"from_type"} = undef;
$self->{"from_subcode"} = undef;
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 = mselect((my $rout=$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_pid = -1;
$from_seq = -1;
$from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS);
($from_port, $from_ip) = sockaddr_in($from_saddr);
($from_type, $from_subcode) = unpack("C2", substr($recv_msg, 20, 2));
if ($from_type == ICMP_ECHOREPLY) {
($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 24, 4))
if length $recv_msg >= 28;
} else {
($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 52, 4))
if length $recv_msg >= 56;
}
$self->{"from_ip"} = $from_ip;
$self->{"from_type"} = $from_type;
$self->{"from_subcode"} = $from_subcode;
if (($from_pid == $self->{"pid"}) && # Does the packet check out?
(! $source_verify || (inet_ntoa($from_ip) eq inet_ntoa($ip))) &&
($from_seq == $self->{"seq"})) {
if ($from_type == ICMP_ECHOREPLY) {
$ret = 1;
$done = 1;
} elsif ($from_type == ICMP_UNREACHABLE) {
$done = 1;
}
}
} else { # Oops, timed out
$done = 1;
}
}
return $ret;
}
sub icmp_result {
my ($self) = @_;
my $ip = $self->{"from_ip"} || "";
$ip = "\0\0\0\0" unless 4 == length $ip;
return (inet_ntoa($ip),($self->{"from_type"} || 0), ($self->{"from_subcode"} || 0));
}
# Description: Do a checksum on the message. Basically sum all of
# the short words and fold the high order bits into the low order bits.
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("n$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
# 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.
sub ping_tcp
{
my ($self,
$ip, # Packed IP number of the host
$timeout # Seconds after which ping times out
) = @_;
my ($ret # The return value
);
$! = 0;
$ret = $self -> tcp_connect( $ip, $timeout);
if (!$self->{"econnrefused"} &&
$! == ECONNREFUSED) {
$ret = 1; # "Connection refused" means reachable
}
$self->{"fh"}->close();
return $ret;
}
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);
my $ret = 0; # Default to unreachable
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 - $!");
}
if ($self->{'device'}) {
setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'}))
or croak("error binding to device $self->{'device'} $!");
}
if ($self->{'tos'}) {
setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'}))
or croak "error configuring tos to $self->{'tos'} $!";
}
};
my $do_connect = sub {
$self->{"ip"} = $ip;
# ECONNREFUSED is 10061 on MSWin32. If we pass it as child error through $?,
# we'll get (10061 & 255) = 77, so we cannot check it in the parent process.
return ($ret = connect($self->{"fh"}, $saddr) || ($! == ECONNREFUSED && !$self->{"econnrefused"}));
};
my $do_connect_nb = sub {
# Set O_NONBLOCK property on filehandle
$self->socket_blocking_mode($self->{"fh"}, 0);
# start the connection attempt
if (!connect($self->{"fh"}, $saddr)) {
if ($! == ECONNREFUSED) {
$ret = 1 unless $self->{"econnrefused"};
} elsif ($! != EINPROGRESS && ($^O ne 'MSWin32' || $! != EWOULDBLOCK)) {
# EINPROGRESS is the expected error code after a connect()
# on a non-blocking socket. But if the kernel immediately
# determined that this connect() will never work,
# Simply respond with "unreachable" status.
# (This can occur on some platforms with errno
# EHOSTUNREACH or ENETUNREACH.)
return 0;
} else {
# Got the expected EINPROGRESS.
# Just wait for connection completion...
my ($wbits, $wout, $wexc);
$wout = $wexc = $wbits = "";
vec($wbits, $self->{"fh"}->fileno, 1) = 1;
my $nfound = mselect(undef,
($wout = $wbits),
($^O eq 'MSWin32' ? ($wexc = $wbits) : undef),
$timeout);
warn("select: $!") unless defined $nfound;
if ($nfound && vec($wout, $self->{"fh"}->fileno, 1)) {
# the socket is ready for writing so the connection
# attempt completed. test whether the connection
# attempt was successful or not
if (getpeername($self->{"fh"})) {
# Connection established to remote host
$ret = 1;
} else {
# TCP ACK will never come from this host
# because there was an error connecting.
# This should set $! to the correct error.
my $char;
sysread($self->{"fh"},$char,1);
$! = ECONNREFUSED if ($! == EAGAIN && $^O =~ /cygwin/i);
$ret = 1 if (!$self->{"econnrefused"}
&& $! == ECONNREFUSED);
}
} else {
# the connection attempt timed out (or there were connect
# errors on Windows)
if ($^O =~ 'MSWin32') {
# If the connect will fail on a non-blocking socket,
# winsock reports ECONNREFUSED as an exception, and we
# need to fetch the socket-level error code via getsockopt()
# instead of using the thread-level error code that is in $!.
if ($nfound && vec($wexc, $self->{"fh"}->fileno, 1)) {
$! = unpack("i", getsockopt($self->{"fh"}, SOL_SOCKET,
SO_ERROR));
}
}
}
}
} else {
# Connection established to remote host
$ret = 1;
}
# Unset O_NONBLOCK property on filehandle
$self->socket_blocking_mode($self->{"fh"}, 1);
$self->{"ip"} = $ip;
return $ret;
};
if ($syn_forking) {
# 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.
# XXX Above comments are not true at least for Win2K, where
# nonblocking connect works.
$| = 1; # Clear buffer prior to fork to prevent duplicate flushing.
$self->{'tcp_chld'} = fork;
if (!$self->{'tcp_chld'}) {
if (!defined $self->{'tcp_chld'}) {
# Fork did not work
warn "Fork error: $!";
return 0;
}
&{ $do_socket }();
# Try a slow blocking connect() call
# and report the status to the parent.
if ( &{ $do_connect }() ) {
$self->{"fh"}->close();
# No error
exit 0;
} else {
# Pass the error status to the parent
# Make sure that $! <= 255
exit($! <= 255 ? $! : 255);
}
}
&{ $do_socket }();
my $patience = &time() + $timeout;
my ($child, $child_errno);
$? = 0; $child_errno = 0;
# Wait up to the timeout
# And clean off the zombie
do {
$child = waitpid($self->{'tcp_chld'}, &WNOHANG());
$child_errno = $? >> 8;
select(undef, undef, undef, 0.1);
} while &time() < $patience && $child != $self->{'tcp_chld'};
if ($child == $self->{'tcp_chld'}) {
if ($self->{"proto"} eq "stream") {
# We need the socket connected here, in parent
# Should be safe to connect because the child finished
# within the timeout
&{ $do_connect }();
}
# $ret cannot be set by the child process
$ret = !$child_errno;
} else {
# Time must have run out.
# Put that choking client out of its misery
kill "KILL", $self->{'tcp_chld'};
# Clean off the zombie
waitpid($self->{'tcp_chld'}, 0);
$ret = 0;
}
delete $self->{'tcp_chld'};
$! = $child_errno;
} else {
# Otherwise don't waste the resources to fork
&{ $do_socket }();
&{ $do_connect_nb }();
}
return $ret;
}
sub DESTROY {
my $self = shift;
if ($self->{'proto'} eq 'tcp' &&
$self->{'tcp_chld'}) {
# Put that choking client out of its misery
kill "KILL", $self->{'tcp_chld'};
# Clean off the zombie
waitpid($self->{'tcp_chld'}, 0);
}
}
# 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(mselect($rin, $rout, undef, ($time + $timeout) - &time())) {
if($rout && vec($rout,$self->{"fh"}->fileno(),1)) {
my $num = syswrite($self->{"fh"}, $wrstr, length $wrstr);
if($num) {
# If it was a partial write, update and try again.
$wrstr = substr($wrstr,$num);
} else {
# There was an error.
$ret = 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;
}
}
}
} until &time() > ($time + $timeout) || defined($ret);
EOM
return $ret;
}
# 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.
sub ping_stream
{
my ($self,
$ip, # Packed IP number of the host
$timeout # Seconds after which ping times out
) = @_;
# Open the stream if it's not already open
if(!defined $self->{"fh"}->fileno()) {
$self->tcp_connect($ip, $timeout) or return 0;
}
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
# get a message, make sure all of its parts match. If they do, we are
# 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 ($saddr, # sockaddr_in with port and ip
$ret, # The return value
$msg, # Message to be echoed
$finish_time, # Time ping should be finished
$flush, # Whether socket needs to be disconnected
$connect, # Whether socket needs to be connected
$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
if ($self->{"connected"}) {
if ($self->{"connected"} ne $saddr) {
# Still connected to wrong destination.
# Need to flush out the old one.
$flush = 1;
}
} else {
# Not connected yet.
# Need to connect() before send()
$connect = 1;
}
# Have to connect() and send() instead of sendto()
# in order to pick up on the ECONNREFUSED setting
# from recv() or double send() errno as utilized in
# the concept by rdw @ perlmonks. See:
# http://perlmonks.thepen.com/42898.html
if ($flush) {
# Need to socket() again to flush the descriptor
# This will disconnect from the old saddr.
socket($self->{"fh"}, PF_INET, SOCK_DGRAM,
$self->{"proto_num"});
}
# Connect the socket if it isn't already connected
# to the right destination.
if ($flush || $connect) {
connect($self->{"fh"}, $saddr); # Tie destination to socket
$self->{"connected"} = $saddr;
}
send($self->{"fh"}, $msg, UDP_FLAGS); # Send it
$rbits = "";
vec($rbits, $self->{"fh"}->fileno(), 1) = 1;
$ret = 0; # Default to unreachable
$done = 0;
my $retrans = 0.01;
my $factor = $self->{"retrans"};
$finish_time = &time() + $timeout; # Ping needs to be done by then
while (!$done && $timeout > 0)
{
if ($factor > 1)
{
$timeout = $retrans if $timeout > $retrans;
$retrans*= $factor; # Exponential backoff
}
$nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for response
my $why = $!;
$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);
if (!$from_saddr) {
# For example an unreachable host will make recv() fail.
if (!$self->{"econnrefused"} &&
($! == ECONNREFUSED ||
$! == ECONNRESET)) {
# "Connection refused" means reachable
# Good, continue
$ret = 1;
}
$done = 1;
} else {
($from_port, $from_ip) = sockaddr_in($from_saddr);
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;
}
}
}
elsif ($timeout <= 0) # Oops, timed out
{
$done = 1;
}
else
{
# Send another in case the last one dropped
if (send($self->{"fh"}, $msg, UDP_FLAGS)) {
# Another send worked? The previous udp packet
# must have gotten lost or is still in transit.
# Hopefully this new packet will arrive safely.
} else {
if (!$self->{"econnrefused"} &&
$! == ECONNREFUSED) {
# "Connection refused" means reachable
# Good, continue
$ret = 1;
}
$done = 1;
}
}
}
return $ret;
}
# 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'} $!");
}
if ($self->{'tos'}) {
setsockopt($fh, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'}))
or croak "error configuring tos to $self->{'tos'} $!";
}
# Set O_NONBLOCK property on filehandle
$self->socket_blocking_mode($fh, 0);
# 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 || ($^O eq 'MSWin32' && $! == EWOULDBLOCK)) {
# 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'} $!");
}
if ($self->{'tos'}) {
setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'}))
or croak "error configuring tos to $self->{'tos'} $!";
}
$!=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 16 chars including \n
$wrstr .= " "x(15 - length $wrstr). "\n";
syswrite($self->{"fork_wr"}, $wrstr, length $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->{"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*\z/) {
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*\z/) {
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 $nfound = mselect(undef, ($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*\z/ &&
!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->{"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 $char;
sysread($entry->[2],$char,1);
# Store the excuse why the connection failed.
$self->{"bad"}->{$entry->[0]} = $!;
if (!$self->{"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 = mselect((my $rout=$rbits), undef, undef, $timeout)) {
# Done waiting for one of the ACKs
if (!sysread($self->{"fork_rd"}, $_, 16)) {
# Socket closed, which means all children are done.
return ();
}
my ($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->{"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 ($self) = @_;
if ($self->{"proto"} eq "syn") {
delete $self->{"syn"};
} elsif ($self->{"proto"} eq "tcp") {
# The connection will already be closed
} else {
$self->{"fh"}->close();
}
}
sub port_number {
my $self = shift;
if(@_) {
$self->{port_num} = shift @_;
$self->service_check(1);
}
return $self->{port_num};
}
1;
__END__
=head1 NAME
Net::Ping - check a remote host for reachability
=head1 SYNOPSIS
use Net::Ping;
$p = Net::Ping->new();
print "$host is alive.\n" if $p->ping($host);
$p->close();
$p = Net::Ping->new("icmp");
$p->bind($my_addr); # Specify source interface of pings
foreach $host (@host_array)
{
print "$host is ";
print "NOT " unless $p->ping($host, 2);
print "reachable.\n";
sleep(1);
}
$p->close();
$p = Net::Ping->new("tcp", 2);
# Try connecting to the www port instead of the echo port
$p->port_number(getservbyname("http", "tcp"));
while ($stop_time > time())
{
print "$host not reachable ", scalar(localtime()), "\n"
unless $p->ping($host);
sleep(300);
}
undef($p);
# Like tcp protocol, but with many hosts
$p = Net::Ping->new("syn");
$p->port_number(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();
$p->hires();
($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);
=head1 DESCRIPTION
This module contains methods to test the reachability of remote
hosts on a network. A ping object is first created with optional
parameters, a variable number of hosts may be pinged multiple
times and then the connection is closed.
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 "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
successfully established, the remote host is considered reachable. No
data is actually echoed. This protocol does not require any special
privileges but has higher overhead than the "udp" and "icmp" protocols.
Specifying the "udp" protocol causes the ping() method to send a udp
packet to the remote host's echo port. If the echoed packet is
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 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