NAME
Mail::ClamAV - Perl extension for the clamav virus scanner
SYNOPSIS
use Mail::ClamAV qw/:all/;
# $Mail::ClamAV::Error in numeric context return clamav's
# error status code which corresponds to the constants which
# can be exported
my $c = new Mail::ClamAV("/path/to/directory/or/file")
or die "Failed to load db: $Mail::ClamAV::Error (", 0+$Mail::;
# You can get retdbdir() to get the database dir in
# clamav's conf
my $c = new Mail::ClamAV(retdbdir())
or die "Failed to load db: $Mail::ClamAV::Error";
# When database is loaded, you must create the proper trie with:
$c->build or die "Failed to build engine: $Mail::ClamAV::Error";
# check to see if we need to reload
if ($c->statchkdir) {
$c = new Mail::ClamAV(retdbdir());
$c->build or die "Failed to build engine: $Mail::ClamAV::Error";
}
# Set some limits (only applies to scan())
$c->maxreclevel(4);
$c->maxfiles(20);
$c->maxfilesize(1024 * 1024 * 20); # 20 megs
$c->archivememlim(0); # limit memory usage for bzip2 (0/1)
# Scan a filehandle (scandesc in clamav)
# scan(FileHandle or path, Bitfield of options)
my $status = $c->scan(FH, CL_SCAN_ARCHIVE|CL_SCAN_MAIL);
# Scan a file (scanfile in clamav)
my $status = $c->scan("/path/to/file.eml", CL_SCAN_MAIL);
# $status is an overloaded object
die "Failed to scan: $status" unless $status;
if ($status->virus) {
print "Message is a virus: $status\n";
}
else {
print "No virus found!\n";
}
DESCRIPTION
Clam AntiVirus is an anti-virus toolkit for UNIX http://www.clamav.com/. This module provide a simple interface to its C API.
EXPORT
None by default.
Exportable constants
Options for scanning.
- CL_SCAN_STDOPT
-
This is an alias for a recommended set of scan options. You should use it to make your software ready for new features in the future versions of libclamav.
- CL_SCAN_RAW
-
Use it alone if you want to disable support for special files.
- CL_SCAN_ARCHIVE
-
This flag enables transparent scanning of various archive formats.
- CL_SCAN_BLOCKENCRYPTED
-
With this flag the library will mark encrypted archives as viruses (Encrypted.Zip, Encrypted.RAR).
- CL_SCAN_BLOCKMAX
-
Mark archives as viruses if maxfiles, maxfilesize, or maxreclevel limit is reached.
- CL_SCAN_MAIL
-
Enable support for mail files.
- CL_SCAN_MAILURL
-
The mail scanner will download and scan URLs listed in a mail body. This flag should not be used on loaded servers. Due to potential problems please do not enable it by default but make it optional.
- CL_SCAN_OLE2
-
Enables support for OLE2 containers (used by MS Office and .msi files).
- CL_SCAN_PE
-
This flag enables deep scanning of Portable Executable files and allows libclamav to unpack executables compressed with run-time unpackers.
- CL_SCAN_ELF
-
Enable support for ELF files.
- CL_SCAN_BLOCKBROKEN
-
libclamav will try to detect broken executables and mark them as Broken.Executable.
- CL_SCAN_HTML
-
This flag enables HTML normalisation (including ScrEnc decryption).
- CL_SCAN_ALGORITHMIC
-
Enable algorithmic detection of viruses.
- CL_SCAN_PHISHING_DOMAINLIST
-
With a minor version bump clamav development team removed this and broke backwards compatibility, so it is no longer supported in this module as of 0.22.
- CL_SCAN_PHISHING_BLOCKSSL
-
Phishing module: always block SSL mismatches in URLs.
- CL_SCAN_PHISHING_BLOCKCLOAK
-
Phishing module: always block cloaked URLs.
Status returns. You can get the status code by putting the status object returned into into numeric context.
my $status = $c->scan("foo.txt");
print "Status: ", ($status + 0), "\n";
The following are returned statuses if no error occured.
- CL_CLEAN
-
no viruses found
- CL_VIRUS
-
virus found, put the status in scalar context to see the type
Error statuses
- CL_EMAXREC
-
recursion limit exceeded
- CL_EMAXSIZE
-
size limit exceeded
- CL_EMAXFILES
-
files limit exceeded
- CL_EACCES
-
access denied
- CL_ENULLARG
-
null argument
- CL_ETMPFILE
-
tmpfile() failed
- CL_EMEM
-
memory allocation error
- CL_EOPEN
-
file open error
- CL_EMALFDB
-
malformed database
- CL_ETMPDIR
-
mkdir() failed
- CL_ECVD
-
not a CVD file (or broken)
- CL_EFORMAT
-
bad format or broken file
- CL_ENCINIT
-
NodalCore initialization failed
- CL_ENCLOAD
-
error loading NodalCore database
- CL_ENCIO
-
general NodalCore I/O error
Exportable functions
These function can be exported either individually or using the :all export flags
- retdbdir
-
This function returns the path to the database directory specified when clamav was compiled.
METHODS
Settings
NOTE These settings only apply to scan()
and archives (CL_SCAN_ARCHIVE).
- maxreclevel
-
Sets the maximum recursion level into archives [default 5].
- maxmailrec
-
With a minor version bump clamav development team removed this and broke backwards compatibility, so it is no longer supported in this module as of 0.22.
- maxfiles
-
Maximum number of files that will be scanned [default 1000]. A value of zero disables the check.
- maxfilesize
-
Maximum file size that will be scanned in bytes [default 10M]. A value of zero disables the check.
- maxratio
-
With a minor version bump clamav development team removed this and broke backwards compatibility, so it is no longer supported in this module as of 0.22.
- archivememlim
-
Turns on/off memory usage limits for bzip2. [default 1]
Scanning
All of these methods return a status object. This object is overloaded to make things cleaner. In boolean context this will return false if there was an error. For example: my $status = $c->scan("foo.txt"); die "Error scanning: $status" unless $status;
As you probably just noticed, $status in scalar context returns the error message. In addition to the overloading you just saw, $status has the following methods:
- errno
-
The numeric value (if any) clamav returned.
- clean
-
This will be true if the message was not a virus and an error did not occur.
- virus
-
Returns true if the message is a virus.
- error
-
Return the error message (if any). This is the same thing as quoting $status.
- count
-
Returns the number of messages scanned. Only works with archives.
- scan(FileHandle or Path, Bitfield of options)
-
scan()
takes a FileHanle or path and passed the file descriptor for that off to clamav. The second argument is a bitfield of options, CL_SCAN_MAIL, CL_SCAN_ARCHIVE or CL_SCAN_RAW "Exportable constants".This function returns the status object discussed earlier.
Note that if you are running in taint mode (-T) and a tainted path is passed to
scan()
, it willcroak()
. - scanbuff($buff)
-
This function was taken out of ClamAV in 0.90 and was thus taken out of Mail::ClamAV.
Data Directory stats
If the path passed into new()
is a directory Mail::ClamAV will set things up to check for updated database files. Calling the statchkdir()
will check the database directory to the stats we have in memory. If anything has changed true is returned, otherwise false.
NOTE: trying to use statchkdir()
when you passed in a database file instead of directory will produce a fatal error.
statchkdir()
is useful for long running daemons that need to check to see if it is time to reload the database. Reloading is simply getting a new Mail::ClamAV object and initializing it.
SEE ALSO
The ClamAV API documentation http://www.clamav.net/doc/html-0.65/node44.html
AUTHOR
Scott Beck <sbeck@gossamer-threads.com>
COPYRIGHT AND LICENSE
Copyright (C) 2003 by Gossamer Threads Inc. http://www.gossamer-threads.com
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.1 or, at your option, any later version of Perl 5 you may have available.