commit - 1f2ab849c05c3eb4eaf9088536733e351050c98e
commit + 0e6fee11c89b146aa5419bbdf26514bc34bdaf81
blob - /dev/null
blob + 03d3f0eb209159507d8139f49c81973b5b54e60e (mode 755)
--- /dev/null
+++ mail/lib/validateattachment
+#!/usr/local/plan9/bin/rc
+rfork n
+
+. 9.rc
+
+# exit status matching:
+#
+# *discard* - is really bad, refuse the message
+# *accept* - is really good, leave attachment alone
+# * - rewrite attachment to have .suspect extension
+#
+
+# magic exit statuses known to vf
+accept=10
+discard=13
+
+wrap=123 # anything but 10, 13
+
+if(! ~ $#* 1){
+ echo usage: validateattachment mboxfile >[1=2]
+ exit usage
+}
+
+upas/unvf < $1 >$1.unvf
+file=$1.unvf
+fn sigexit { rm $file }
+
+fn save {
+# d=`{date -n}
+# cp $file /n/other/upas/tmp/$d.$1
+# cp raw /n/other/upas/tmp/$d.$1.raw
+# whatis x >/n/other/upas/tmp/$d.$1.file
+}
+
+x=`{file <$file | sed s/stdin://}
+x=$"x
+switch($x){
+case *Ascii* *text* *'c program'* *'rc executable'*
+ save accept
+ exit $accept
+
+case *'zip archive'*
+ # >[2=1] because sometimes we get zip files we can't parse
+ # but the errors look like
+ # unzip: reading data for philw.doc.scr failed: ...
+ # so we can still catch these.
+ if(unzip -tsf $file >[2=1] | grep -si ' |\.(scr|exe|pif|bat|com)$'){
+ echo executables inside zip file!
+ exit $discard
+ }
+
+case jpeg 'PNG image' bmp 'GIF image' *'plan 9 image'
+ save accept
+ exit $accept
+
+case *Microsoft* *Office*
+ save wrap
+ exit $wrap
+
+case *MSDOS*
+ # no executables
+ echo $x
+ exit $discard
+}
+
+save wrap
+exit $wrap
+
+