package Net::Ping;
-# $Id: Ping.pm,v 1.6 2002/06/19 15:23:48 rob Exp $
-
require 5.002;
require Exporter;
use strict;
use vars qw(@ISA @EXPORT $VERSION
- $def_timeout $def_proto $max_datasize $pingstring $hires $source_verify);
-use FileHandle;
-use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET
+ $def_timeout $def_proto $def_factor
+ $max_datasize $pingstring $hires $source_verify $syn_forking);
+use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK );
+use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET SO_ERROR
inet_aton inet_ntoa sockaddr_in );
+use POSIX qw( ENOTCONN ECONNREFUSED ECONNRESET EINPROGRESS EWOULDBLOCK EAGAIN WNOHANG );
+use FileHandle;
use Carp;
-use POSIX qw(ECONNREFUSED);
@ISA = qw(Exporter);
@EXPORT = qw(pingecho);
-$VERSION = "2.20";
+$VERSION = "2.31";
+
+sub SOL_IP { 0; };
+sub IP_TOS { 1; };
# Constants
$def_timeout = 5; # Default timeout to wait for a reply
$def_proto = "tcp"; # Default protocol to use for pinging
+$def_factor = 1.2; # Default exponential backoff rate.
$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?
+ *ENOTCONN = sub {10057;};
+ *ECONNRESET = sub {10054;};
+ *EINPROGRESS = sub {10036;};
+ *EWOULDBLOCK = sub {10035;};
+# $syn_forking = 1; # XXX possibly useful in < Win2K ?
};
+# h2ph "asm/socket.h"
+# require "asm/socket.ph";
+sub SO_BINDTODEVICE {25;}
+
# Description: The pingecho() subroutine is provided for backward
# compatibility with the original Net::Ping. It accepts a host
# name/IP and an optional timeout in seconds. Create a tcp ping
my ($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
+ $tos, # Optional ToS to set
) = @_;
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;
+
+ $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")
}
$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
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 $^O ne 'VMS');
+ croak("icmp ping requires root privilege") if ($> 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")
{
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);
}
CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) ||
croak("$self->{'proto'} bind error - $!");
}
- elsif ($self->{"proto"} ne "tcp")
+ 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);
+ $t -= $gran;
+ return $nfound if $nfound or !defined($nfound) or $t <= 0;
+
+ sleep(0);
+ ($_[0], $_[1], $_[2]) = @args;
+ }
+ }
+ else {
+ return select($_[0], $_[1], $_[2], $_[3]);
+ }
+}
# Description: Allow UDP source endpoint comparision to be
# skipped for those remote interfaces that do
($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
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
croak("Timeout must be greater than 0 seconds") if $timeout <= 0;
$ip = inet_aton($host);
- return(undef) unless defined($ip); # Does host exist?
+ return () unless defined($ip); # Does host exist?
# Dispatch to the appropriate routine.
$ping_time = &time();
}
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()");
}
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 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
$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 = "";
$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
+ $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
{
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, $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) &&
- (!$source_verify || $from_ip eq $ip) &&
- ($from_pid == $self->{"pid"}) && # Does the packet check out?
- ($from_seq == $self->{"seq"}))
- {
- $ret = 1; # It's a winner
+ ($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?
+ ($from_seq == $self->{"seq"})) {
+ if ($from_type == ICMP_ECHOREPLY){
+ $ret = 1;
+ }
$done = 1;
}
- }
- else # Oops, timed out
- {
+ } 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.
$len_msg = length($msg);
$num_short = int($len_msg / 2);
$chk = 0;
- foreach $short (unpack("S$num_short", $msg))
+ foreach $short (unpack("n$num_short", $msg))
{
$chk += $short;
} # Add the odd byte in
my ($ret # The return value
);
- $@ = ""; $! = 0;
+ $! = 0;
$ret = $self -> tcp_connect( $ip, $timeout);
- $ret = 1 if $! == ECONNREFUSED; # Connection refused
+ if (!$self->{"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'} $!");
+ }
+ 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 {
- eval {
- die $! unless connect($self->{"fh"}, $saddr);
- $self->{"ip"} = $ip;
- $ret = 1;
- };
- $ret;
+ $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.
- if ($^O =~ /Win32/i) {
+ # This should set $! to the correct error.
+ my $char;
+ sysread($self->{"fh"},$char,1);
+ $! = ECONNREFUSED if ($! == EAGAIN && $^O =~ /cygwin/i);
- # Buggy Winsock API doesn't allow us to use alarm() calls.
+ $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.
- my $pid = fork;
- if (!$pid) {
- if (!defined $pid) {
+ $self->{'tcp_chld'} = fork;
+ if (!$self->{'tcp_chld'}) {
+ if (!defined $self->{'tcp_chld'}) {
# Fork did not work
- warn "Win32 Fork error: $!";
+ warn "Fork error: $!";
return 0;
}
&{ $do_socket }();
# Try a slow blocking connect() call
- # and report the status to the pipe.
+ # 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
- exit $!;
+ # Make sure that $! <= 255
+ exit($! <= 255 ? $! : 255);
}
}
my $patience = &time() + $timeout;
- require POSIX;
- my ($child);
- $? = 0;
+ my ($child, $child_errno);
+ $? = 0; $child_errno = 0;
# Wait up to the timeout
# And clean off the zombie
do {
- $child = waitpid($pid, &POSIX::WNOHANG);
- $! = $? >> 8;
- $@ = $!;
+ $child = waitpid($self->{'tcp_chld'}, &WNOHANG());
+ $child_errno = $? >> 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 }();
+ } 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.
- $@ = "Timed out!";
# Put that choking client out of its misery
- kill "KILL", $pid;
+ kill "KILL", $self->{'tcp_chld'};
# Clean off the zombie
- waitpid($pid, 0);
+ waitpid($self->{'tcp_chld'}, 0);
$ret = 0;
}
- } else { # Win32
+ delete $self->{'tcp_chld'};
+ $! = $child_errno;
+ } else {
# Otherwise don't waste the resources to fork
&{ $do_socket }();
- $SIG{'ALRM'} = sub { die "Timed out!"; };
- alarm($timeout); # Interrupt connect() if we have to
-
- &{ $do_connect }();
- alarm(0);
+ &{ $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
vec($rout, $self->{"fh"}->fileno(), 1) = 1;
}
- if(select($rin, $rout, undef, ($time + $timeout) - &time())) {
+ if(mselect($rin, $rout, undef, ($time + $timeout) - &time())) {
if($rout && vec($rout,$self->{"fh"}->fileno(),1)) {
- my $num = syswrite($self->{"fh"}, $wrstr);
+ my $num = syswrite($self->{"fh"}, $wrstr, length $wrstr);
if($num) {
# If it was a partial write, update and try again.
$wrstr = substr($wrstr,$num);
# of time. Return the result of our efforts.
use constant UDP_FLAGS => 0; # Nothing special on send or recv
-
sub ping_udp
{
my ($self,
$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
$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
+
+ 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)
{
- $nfound = select($rbits, undef, undef, $timeout); # Wait for response
+ 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
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 (!$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
+ $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;
+ }
}
}
- else # Oops, timed out
+ 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: 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'} $!");
+ }
+ 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) = @_;
- $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 1.6 2002/06/19 15:23:48 rob Exp $
-
=head1 SYNOPSIS
use Net::Ping;
}
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
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 other two protocols.
+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
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 [, $tos ]]]]]);
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.
+
+If $tos is given, this ToS is configured into the soscket.
+
=item $p->ping($host [, $timeout]);
Ping the remote host and wait for a response. $host can be either 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
+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.
This is enabled by default.
+=item $p->service_check( { 0 | 1 } );
+
+Set whether or not the 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.
+For udp protocol, enabling this option demands that the
+remote server replies with the same udp data that it was sent
+as defined by the udp echo service.
+
+This affects the "udp", "tcp", and "syn" protocols.
+
+This is disabled by default.
+
+=item $p->tcp_service_check( { 0 | 1 } );
+
+Depricated method, but does the same as service_check() method.
+
=item $p->hires( { 0 | 1 } );
Causes this module to use Time::HiRes module, allowing milliseconds
=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 $p->close();
Close the network connection for this ping object. The network
=back
-=head1 WARNING
-
-pingecho() or a ping object with the tcp protocol use alarm() to
-implement the timeout. So, don't use alarm() in your program while
-you are using pingecho() or a ping object with the tcp protocol. The
-udp and icmp protocols do not use alarm() to implement the timeout.
-
=head1 NOTES
There will be less network overhead (and some efficiency in your
The latest source tree is available via cvs:
- cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware co Net-Ping
+ cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping
cd Net-Ping
The tarball can be created as follows:
rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm
+=head1 BUGS
+
+For a list of known issues, visit:
+
+https://rt.cpan.org/NoAuth/Bugs.html?Dist=Net-Ping
+
+To report a new bug, visit:
+
+https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Net-Ping
+
=head1 AUTHORS
Current maintainer:
=head1 COPYRIGHT
-Copyright (c) 2002, Rob Brown. All rights reserved.
+Copyright (c) 2002-2003, Rob Brown. All rights reserved.
Copyright (c) 2001, Colin McMillen. All rights reserved.
This program is free software; you may redistribute it and/or
modify it under the same terms as Perl itself.
+$Id: Ping.pm,v 1.86 2003/06/27 21:31:07 rob Exp $
+
=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff