#!/usr/bin/perl
# (c) Copyright 2006-2010, 2016. CodeWeavers, Inc.
use warnings;
use strict;

# Portable which(1) implementation
sub cxwhich($$;$)
{
    my ($dirs, $app, $noexec)=@_;
    if ($app =~ /^\//)
    {
        return $app if ((-x $app or $noexec) and -f $app);
    }
    elsif ($app =~ /\//)
    {
        require Cwd;
        my $path=Cwd::cwd() . "/$app";
        return $path if ((-x $path or $noexec) and -f $path);
    }
    else
    {
        foreach my $dir (split /:/, $dirs)
        {
            return "$dir/$app" if ($dir ne "" and (-x "$dir/$app" or $noexec) and -f "$dir/$app");
        }
    }
    return undef;
}

# Fast dirname() implementation
sub _cxdirname($)
{
    my ($path)=@_;
    return undef if (!defined $path);
    return "." if ($path !~ s!/+[^/]+/*$!!s);
    return "/" if ($path eq "");
    return $path;
}

# Locate where CrossOver is installed by looking for the directory
# where the cxmenu script is located, unwinding symlinks on the way
sub locate_cx_root(;$)
{
    my ($fallback)=@_;
    my $argv0=cxwhich($ENV{PATH},$0);
    $argv0=$0 if (!defined $argv0);
    if ($argv0 !~ m+^/+)
    {
        require Cwd;
        $argv0=Cwd::cwd() . "/$argv0";
    }
    my $dir=_cxdirname($argv0);
    my $bindir=$dir;
    $bindir =~ s%/lib$%/bin%;
    while (!-x "$bindir/cxmenu" or !-f "$bindir/cxmenu")
    {
        last if (!-l $argv0);
        $argv0=readlink($argv0);
        $argv0="$dir/$argv0" if ($argv0 !~ m+^/+);
        $dir=_cxdirname($argv0);
        $bindir=$dir;
        $bindir =~ s%/lib$%/bin%;
    }
    $bindir =~ s%/(?:\./)+%/%g;
    $bindir =~ s%/\.$%%;
    $ENV{CX_ROOT}=_cxdirname($bindir);
    if ((!-x "$ENV{CX_ROOT}/bin/cxmenu" or !-f "$ENV{CX_ROOT}/bin/cxmenu") and
        $fallback)
    {
        $ENV{CX_ROOT}=$fallback;
    }
    if (!-x "$ENV{CX_ROOT}/bin/cxmenu" or !-f "$ENV{CX_ROOT}/bin/cxmenu")
    {
        my $name0=$0;
        $name0 =~ s+^.*/++;
        print STDERR "$name0:error: could not find CrossOver in '$ENV{CX_ROOT}'\n";
        exit 1;
    }
    return $ENV{CX_ROOT};
}

BEGIN {
    unshift @INC, locate_cx_root() . "/lib/perl";
}
use CXLog;
use CXUtils;

# Process command-line options
my $opt_quiet;
my $opt_verbose;
my $opt_help;
require CXOpts;
my $cxopts=CXOpts->new(["stop_on_unknown","stop_on_non_option"]);
$cxopts->add_options(["quiet!"      => \$opt_quiet,
                      "verbose!"    => \$opt_verbose,
                      "?|h|help"    => \$opt_help
                     ]);
my $err=$cxopts->parse();
CXLog::fdopen(2) if ($opt_verbose);


# Validate the command line options
my $usage;
if ($err)
{
    cxerr("$err\n");
    $usage=2;
}
elsif ($opt_help)
{
    $usage=0;
}
elsif (!@ARGV)
{
    cxerr("you must specify the file to scan\n");
    $usage=2;
}


# Print usage
if (defined $usage)
{
    my $name0=cxname0();
    if ($usage)
    {
        cxerr("try '$name0 --help' for more information\n");
        exit $usage;
    }
    print "Usage: $name0 [--help] [--quiet] [--verbose] FILE\n";

    print "\n";
    print "Invokes a native antivirus tool to scan the specified file for Windows viruses.\n";

    print "\n";
    print "Options:\n";
    print "  FILE            The file to scan\n";
    print "  --quiet         Don't display the 'Scanning...' message\n";
    print "  --verbose       Print more information about what is going on\n";
    print "  --help, -h      Shows this help message\n";

    print "\n";
    print "The exit code is 0 if the file contains no virus, 1 if it is infected, 2 for usage errors, and 3 if no antivirus tool is available.\n";
    exit 0;
}

my $pid;
if (!$opt_quiet)
{
    $pid=cxwait(1, "--no-focus", "Scanning for viruses");
}


# Import the CrossOver settings
my $productid=CXUtils::get_product_id();
require CXConfig;
my $cxconfig=CXConfig->new("$ENV{CX_ROOT}/etc/$productid.conf",
                           "$ENV{HOME}/.$productid/$productid.conf");
my $scanner=$cxconfig->get("CrossOver", "AntiVirusCommand");
my ($clean, $match);

if (!$scanner)
{
    $scanner=cxwhich($ENV{PATH}, "clamdscan");
    if (defined $scanner)
    {
        my $cmd=join(" ", shquote_string($scanner), "--no-summary",
                     (map { shquote_string($_) } @ARGV), "2>&1");
        my $output=cxbackquote($cmd);
        if ($? == 0)
        {
            # No virus found
            kill(15, $pid) if (defined $pid);
            exit 0;
        }
        elsif ($? == 256)
        {
            # Found a virus
            print $output;
            kill(15, $pid) if (defined $pid);
            exit 1;
        }
        # Else clamdscan did not work
    }
    my @known_avs=(
        ["clamscan --no-summary --", "0", "1"],          # Clam AntiVirus
        ["avastcmd", "[02]", "[13]"],                    # Avast Antivirus
        ["avgscan", "0", "[4567]"],                      # AVG Anti-Virus
        ["uvscan --exit-on-error", "(?:0|13)", "[cd]"],  # McAfee LinuxShield
        ["fpscan --adware", "0", ".?[1235679abdef]"],    # F-Prot Antivirus
        ["antivir", "0", "[123]"],                       # AntiVir Workstation
        ["sweep --", "(?:0|14)", "(?:3|18)"],            # Sophos Anti-virus
        ["savscan --", "(?:0|14)", "(?:3|18)"]           # Sophos Anti-virus (alternate name)
    );
    foreach my $av (@known_avs)
    {
        my ($candidate, $c, $m)=@$av;
        my @cmd=split / /, $candidate;
        $scanner=cxwhich($ENV{PATH}, shift @cmd);
        if ($scanner)
        {
            $scanner=join(" ", shquote_string($scanner), @cmd);
            ($clean, $match)=($c, $m);
            last;
        }
    }
}
else
{
    $scanner=CXUtils::argv2shcmd(map { expand_string($_) } CXUtils::cmdline2argv($scanner));
    $clean=$cxconfig->get("CrossOver", "AntiVirusClean");
    $clean="0" if (!defined $clean);
    $match=$cxconfig->get("CrossOver", "AntiVirusMatch");
    $match="1" if (!defined $match);
}

if (!$scanner)
{
    cxlog("Found no antivirus tool\n");
    kill(15, $pid) if (defined $pid);
    exit 3;
}

my $cmd=join(" ", $scanner, (map { shquote_string($_) } @ARGV));
my $output=cxbackquote($cmd);
kill(15, $pid) if (defined $pid);
if (($? & 0xff) == 0)
{
    my $rc=sprintf("%x", $? >> 8);
    if ($rc =~ /^$clean$/i)
    {
        # No virus found or they got all cleaned
        exit 0;
    }
    if ($rc =~ /^$match$/i)
    {
        # Found a virus
        print $output;
        exit 1;
    }
}
# The virus scanner malfunctionned
print $output;
printf("\%s: scanner exit code was 0x\%x\n", cxname0(), $?);
exit 2;