avast! for sendmail/milter

Avast Business Avast Business for Linux
1

hi all,
the beta package integrating avast! into sendmail is available at:

http://www2.asw.cz/~mensik/avast4milter-2.0.0b.tar.gz

2

updated version available:
http://www2.asw.cz/~mensik/avast4milter-2.0.1b.tar.gz

3

There’s a problem with 2.0.1b.
In A4FI_HEADER you copy headers to ‘textline’ variable with length of 1001.
You assume that incoming headers have less length. And you dont even check it.
I think that sendmail assembles multiline headers so length can actually be much more than 1001. So 2.0.1b just causes a segmentation fault.
Here’s my patch:

diff -u avastmilter.c.orig avastmilter.c

— avastmilter.c.orig Thu Dec 1 11:39:10 2005
+++ avastmilter.c Sat Dec 24 05:47:08 2005
@@ -383,7 +383,7 @@
{
struct a4fiPriv *priv;
int errval;

  •   char textline[SMTPPROTOCOL_MAXTEXTLINE+1];

  •   const char *splitter = ": ";
  ssize_t nwritten;

  priv = (struct a4fiPriv*)smfi_getpriv( ctx );

@@ -392,12 +392,11 @@
return SMFIS_TEMPFAIL;
}

  •   strcpy( textline, headerf );

  •   strcat( textline, ": " );

  •   strcat( textline, headerv );

  •   strcat( textline, STR_CRLF );

  •   if( file_write( priv->fd, textline, strlen(textline), &nwritten, &errval ) == -1 ) {

  •   if( file_write( priv->fd, headerf, strlen(headerf), &nwritten, &errval ) == -1 ||

  •       file_write( priv->fd, splitter, strlen(splitter), &nwritten, &errval ) == -1 ||

  •       file_write( priv->fd, headerv, strlen(headerv), &nwritten, &errval ) == -1 ||

  •       file_write( priv->fd, STR_CRLF, strlen(STR_CRLF), &nwritten, &errval ) == -1

  •     ) {
          char errstr[128];
          errorstring( errval, errstr, sizeof(errstr) );
          syslog( LOG_ERR, "data write error: %s", errstr );
4

avast4milter fixed and enhanced:

http://www2.asw.cz/~mensik/avast4milter-2.0.1rc.tar.gz
http://www2.asw.cz/~mensik/avast4milter-2.0.1rc-1.i586.rpm