File: big_brother.perl5

package info (click to toggle)
lsof 4.91+dfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 4,984 kB
  • sloc: ansic: 68,893; sh: 6,862; makefile: 1,682; perl: 1,099; awk: 214
file content (210 lines) | stat: -rwxr-xr-x 5,404 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
#!/usr/bin/perl -w
#+##############################################################################
#                                                                              #
# File: big_brother.perl                                                       #
#                                                                              #
# Description: check the network sockets with lsof to detect new connections   #
#									       #
# Contributed by Lionel Cons <Lionel.Cons@cern.ch>			       #
#                                                                              #
#-##############################################################################

# @(#)big_brother	1.12 08/14/96 Written by Lionel.Cons@cern.ch

# no waranty! use this at your own risks!

#
# init & setup
#
$verbose = 1;
$lsof_opt = "-itcp -iudp -Di -FcLPn -r 5";
$SIG{'HUP'} = \&hangup;
chop($hostname = `/bin/hostname`);
$fq_hostname = (gethostbyname($hostname))[0];

# Set path to lsof.

if (($LSOF = &isexec("../lsof")) eq "") {	# Try .. first
    if (($LSOF = &isexec("lsof")) eq "") {	# Then try . and $PATH
	print "can't execute $LSOF\n"; exit 1
    }
}

#
# spy forever...
#
$| = 1;
die "$LSOF is not executable\n" unless -x $LSOF;
while (1) {
    $lsof_pid = open(PIPE, "$LSOF $lsof_opt 2>&1 |")
	|| die "can't start $LSOF: $!\n";
    print "# ", &timestamp, " $LSOF $lsof_opt, pid=$lsof_pid\n"
	if $verbose;
    print "#COMMAND     PID     USER P NAME\n";
    $printed = $hanguped = $pid = $proto = 0;
    while (<PIPE>) {
	if (/^lsof: PID \d+, /) {
	    # fatal error message?
	    print "*** $_";
	    last;
	} elsif (/^lsof: /) {
	    # warning
	    warn "* $_";
	} elsif (/^p(\d+)$/) {
	    &flush;
	    $pid = $1;
	    $proto = 0;
	} elsif (/^c(.*)$/) {
	    $command = $1;
	} elsif (/^L(.*)$/) {
	    $user = $1;
	} elsif (/^P(.*)$/) {
	    &flush;
	    $proto = $1;
	} elsif (/^n(.*)$/) {
	    $name = $1;
	    # replace local hostname by 'localhost'
	    $name =~ s/\Q$fq_hostname\E/localhost/g;
	    $name =~ s/[0-9hms]+ ago//g;
	} elsif (/^m$/) {
	    &flush;
	    &clean;
	} else {
	    warn "* bad output ignored: $_";
	}
    }
    kill('INT',  $lsof_pid);
    kill('KILL', $lsof_pid);
    close(PIPE);
}

sub hangup {
    $hanguped = 1;
    $SIG{'HUP'} = \&hangup;
}

sub flush {
    return unless $pid && $proto;
    return if &skip;
    $tag = sprintf("%-9s %5d %8s %1s %s", $command, $pid, $user,
		   substr($proto, 0, 1), $name);
    unless (defined($seen{$tag})) {
	print "+$tag\n";
	$printed++;
    }
    $seen{$tag} = 1;
}

sub clean {
    my(@to_delete, $tag);

    if ($hanguped) {
	$hanguped = 0;
	@to_delete = keys(%seen);
	print "# ", &timestamp, " hangup received, rescanning all connections\n"
	    if $verbose;
    } else {
	@to_delete = ();
	foreach $tag (keys(%seen)) {
	    if ($seen{$tag} == 0) {
		# not seen this time: delete it
		push(@to_delete, $tag);
		print "-$tag\n";
		$printed++;
	    } else {
		# seen this time: reset the flag
		$seen{$tag} = 0;
	    }
	}
    }
    grep(delete($seen{$_}), @to_delete);
    if ($printed > 10) {
	print "# ", &timestamp, "\n" if $verbose;
	$printed = 0;
    }
}

sub skip {
    #
    # put stuff here to ignore some connections, for instance:
    #

    # what we get when the socket gets created...
    return(1) if $name eq '*:0';
    return(1) if $name =~ /^localhost:(\d+)$/ && $1 > 1000;
#
# UDP & TCP stuff
#
    #
    # ignore common daemons
    #
    if ($name =~ /^\*:/ && $user eq 'root' && $pid < 300) {
	return(1) if $command =~ /^inetd(\.afs)?$/;
	return(1) if $command =~ /^rpc\.(stat|lock)d$/;
	return(1) if $command eq 'syslogd' && $name eq '*:syslog';
    }
    #
    # forking beasts: portmap, ypbind, inetd
    #
    if ($command eq 'portmap' && $user eq 'daemon') {
	return(1) if $name =~ /^\*:/;
    } elsif ($command eq 'ypbind') {
	return(1) if $name =~ /^\*:\d+$/;
    }
#
# TCP-only stuff
#
    return(0) unless $proto eq 'TCP';
    #
    # outgoing commands: ftp, telnet, r*
    #
    if ($command eq 'ftp') {
	return(1) if $name =~ /:ftp(-data)?$/;
    } elsif ($command eq 'telnet') {
	return(1) if $name =~ /:telnet$/;
    } elsif ($command eq 'remsh') {
	if ($name =~ /:(\d?\d\d\d)->.+:(\d?\d\d\d)$/) {
	    return(1) if $1 < 1024 && $1 > 990 && $2 < 1024 && $2 > 990;
	} elsif ($name =~ /:(\d?\d\d\d)->.+:(shell|ta-rauth)$/) {
	    return(1) if $1 < 1024 && $1 > 990;
	} elsif ($name =~ /^\*:(\d?\d\d\d)$/) {
	    return(1) if $1 < 1024 && $1 > 990;
	}
    }
    return(0);
}

sub timestamp {
    my($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst);

    ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
    sprintf("%d/%02d/%02d-%02d:%02d:%02d", $year + 1900, $mon+1, $mday,
      $hour, $min, $sec);
}


## isexec($path) -- is $path executable
#
# $path   = absolute or relative path to file to test for executabiity.
#	    Paths that begin with neither '/' nor '.' that arent't found as
#	    simple references are also tested with the path prefixes of the
#	    PATH environment variable.  

sub
isexec {
    my ($path) = @_;
    my ($i, @P, $PATH);

    $path =~ s/^\s+|\s+$//g;
    if ($path eq "") { return(""); }
    if (($path =~ m#^[\/\.]#)) {
	if (-x $path) { return($path); }
	return("");
    }
    $PATH = $ENV{PATH};
    @P = split(":", $PATH);
    for ($i = 0; $i <= $#P; $i++) {
	if (-x "$P[$i]/$path") { return("$P[$i]/$path"); }
    }
    return("");
}