Only interpret the last command line argument as a file to

be preprocessed if it is specified as an absolute pathname.

PR:		bin/16179

sbin/ipfw/ipfw.8

@@ -20,7 +20,7 @@
 .Oc
 .Op Fl U Ar macro
 .Oc
-.Ar file
+.Ar pathname
 .Nm ipfw
 .Op Fl f | q
 .Cm flush
@@ -207,8 +207,10 @@ To ease configuration, rules can be put into a file which is
 processed using
 .Nm
 as shown in the first synopsis line.
-The
-.Ar file
+An absolute
+.Ar pathname
+must be used.
+The file
 will be read line by line and applied as arguments to the
 .Nm
 utility.
@@ -216,7 +218,7 @@ utility.
 Optionally, a preprocessor can be specified using
 .Fl p Ar preproc
 where
-.Ar file
+.Ar pathname
 is to be piped through.
 Useful preprocessors include
 .Xr cpp 1

sbin/ipfw/ipfw.c

@@ -2363,7 +2363,7 @@ main(ac, av)
 	 * directory, things will fail miserably.
 	 */
 
-	if (ac > 1 && access(av[ac - 1], R_OK) == 0) {
+	if (ac > 1 && av[ac - 1][0] == '/' && access(av[ac - 1], R_OK) == 0) {
 		qflag = pflag = i = 0;
 		lineno = 0;