#!/usr/bin/env python
# aclamfilter: procmail filter for ClamAV virus-checking
# By Adam Sampson <ats@offog.org>
# Based on Matt Hahnfeld's ClamFilter: http://www.everysoft.com/clamfilter.html

BLOCK = 8192
PREFIX = "X-Offog-"

import sys, os, commands, tempfile

def die(s):
	sys.stderr.write("aclamfilter: " + s + "\n")
	sys.stderr.flush()
	sys.exit(1)

def main():
	fn = tempfile.mktemp()
	
	try:
		f = open(fn, "w")
		while 1:
			d = sys.stdin.read(BLOCK)
			if d == "": break
			f.write(d)
		f.close()
	except IOError:
		die("Unable to write temporary file " + fn)

	try:
		(pr, pw) = os.pipe()
	except:
		die("pipe() failed")

	try:
		pid = os.fork()
	except:
		die("fork() failed")

	if pid == 0:
		os.close(pr)
		fd = os.open(fn, os.O_RDONLY)
		os.dup2(fd, 0)
		os.close(fd)
		os.dup2(pw, 1)
		os.dup2(pw, 2)
		cmd = ["clamdscan", "--stdout", "--recursive", "-"]
		os.execvp(cmd[0], cmd)
		sys.stderr.write("aclamfilter: cannot exec " + cmd[0] + "\n")
		sys.stderr.flush()
		os._exit(0)
	os.close(pw)

	f = os.fdopen(pr)
	found = []
	while 1:
		l = f.readline()
		if l == "": break
		l = l.strip()
		i = l.find(": ")
		if l.endswith(" FOUND") and i != -1:
			found.append(l[i + 2:-6])
	f.close()

	(deadpid, status) = os.waitpid(pid, 0)
	if (status >> 8) == 0:
		headers = ""
	else:
		headers = PREFIX + "Virus-Found: " + (" ".join(found)) + "\n"

	f = open(fn, "r")
	while 1:
		l = f.readline()
		if l == "\n" or l == "": break
		sys.stdout.write(l)
	sys.stdout.write(headers)
	sys.stdout.write(l)
	while 1:
		d = f.read(BLOCK)
		if d == "": break
		sys.stdout.write(d)
	sys.stdout.flush()
	f.close()

	os.unlink(fn)
	sys.exit(0)

if __name__ == "__main__":
	main()