| Current File : //usr/share/webmin/status/ping-monitor.pl |
# ping-monitor.pl
# Ping some host
# Contains code ripped from Net::Ping by Russell Mosemann
use Socket;
sub get_ping_status
{
my ($m) = @_;
my $wait = defined($m->{'wait'}) ? $m->{'wait'} : 5;
my $ip = &to_ipaddress($m->{'host'}) ||
&to_ip6address($m->{'host'});
return { 'up' => 0 } if (!$ip);
my $ipv6 = &check_ip6address($m->{'host'}) ||
&to_ip6address($m->{'host'}) &&
!&to_ipaddress($m->{'host'});
if ($config{'pinger'} || $ipv6) {
# Call a ping command if configured, or if using IPv6 since the built-
# in code doesn't support it yet
my $cmd;
my $auto_pinger = $config{'pinger'} eq "linux" || !$config{'pinger'};
if ($auto_pinger && $gconfig{'os_type'} =~ /-linux$/) {
# Use linux command
$cmd = ($ipv6 ? "ping6" : "ping")." -c 1 -w $wait";
}
elsif ($auto_pinger && $gconfig{'os_type'} eq 'freebsd') {
# Use FreeBSD command
$cmd = ($ipv6 ? "ping6" : "ping")." -c 1 -W ".($wait * 1000);
}
elsif ($auto_pinger) {
# Don't know command for this OS
return { 'up' => - 1 };
}
else {
$cmd = $config{'pinger'};
}
my $rv;
my $out;
eval {
local $sig{'ALRM'} = sub { die "timeout" };
alarm($wait + 1);
$out = &backquote_command("$cmd ".quotemeta($m->{'host'}).
" 2>&1 </dev/null");
$rv = $?;
alarm(0);
};
if ($@ =~ /timeout/) {
return { 'up' => 0, 'desc' => &text('ping_timeout', $wait) };
}
elsif ($@) {
return { 'up' => 0, 'desc' => "$@" };
}
elsif ($rv) {
my @l = split(/\r?\n/, $out);
return { 'up' => 0, 'desc' => &html_escape($l[$#l]) };
}
else {
return { 'up' => 1 };
}
}
else {
# Use builtin code
if (!&to_ipaddress($ip)) {
return { 'up' => 0, 'desc' => $text{'ping_resolv'} };
}
my $rv = &ping_icmp(inet_aton($ip), $wait);
return { 'up' => $rv ? 1 : 0 };
}
}
sub show_ping_dialog
{
my ($m) = @_;
print &ui_table_row($text{'ping_host'},
&ui_textbox("host", $m->{'host'}, 50), 3);
print &ui_table_row($text{'ping_wait'},
&ui_textbox("wait", defined($m->{'wait'}) ? $m->{'wait'} : 5, 6).
" ".$text{'oldfile_secs'});
}
sub parse_ping_dialog
{
my ($m) = @_;
#$config{'ping_cmd'} || &error($text{'ping_econfig'});
&to_ipaddress($in{'host'}) || &to_ip6address($in{'host'}) ||
&error($text{'ping_ehost'});
$in{'wait'} =~ /^(\d*\.)?\d+$/ || &error($text{'ping_ewait'});
$m->{'host'} = $in{'host'};
$m->{'wait'} = $in{'wait'};
}
sub ping_icmp
{
my ($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
$data,
$cnt,
$data_size
);
# Construct packet data string
$data_size = 0;
for ($cnt = 0; $cnt < $data_size; $cnt++)
{
$data .= chr($cnt % 256);
}
my $proto_num = (getprotobyname('icmp'))[2];
socket(PSOCK, PF_INET, SOCK_RAW, $proto_num);
$ping_seq = ($ping_seq + 1) % 65536; # Increment sequence
$checksum = 0; # No checksum for starters
$msg = pack($icmp_struct . $data_size, $ICMP_ECHO, $subcode,
$checksum, $$, $ping_seq, $data);
$checksum = checksum($msg);
$msg = pack($icmp_struct . $data_size, $ICMP_ECHO, $subcode,
$checksum, $$, $ping_seq, $data);
$len_msg = length($msg);
$saddr = pack_sockaddr_in($port, $ip);
send(PSOCK, $msg, $flags, $saddr); # Send the message
$rbits = "";
vec($rbits, fileno(PSOCK), 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
{
# Probably an interrupted system call, so try again
$ret = undef;
#$done = 1;
}
elsif ($nfound) # Got a packet from somewhere
{
$recv_msg = "";
$from_saddr = recv(PSOCK, $recv_msg, 1500, $flags);
if ($from_saddr) {
($from_port, $from_ip) = unpack_sockaddr_in($from_saddr);
($from_type, $from_subcode, $from_chk,
$from_pid, $from_seq, $from_msg) =
unpack($icmp_struct . $data_size,
substr($recv_msg, length($recv_msg) - $len_msg,
$len_msg));
if (($from_type == $ICMP_ECHOREPLY) &&
($from_ip eq $ip) &&
($from_pid == $$) && # Does the packet check out?
($from_seq == $ping_seq))
{
$ret = 1; # It's a winner
$done = 1;
}
} else {
# Packet not actually received
$ret = undef;
}
}
else # Oops, timed out
{
$done = 1;
}
}
close(PSOCK);
return($ret)
}
# 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 ($msg # The message to checksum
) = @_;
my ($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 = $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)) if $len_msg % 2;
$chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low
return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement
}