libxtables: do some option structure checking
libxt_recent's use of numeric values >200 always looked worrisome. Now
here is a validation routine for such.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/xtables.c b/xtables.c
index 5b7526c..f8014a6 100644
--- a/xtables.c
+++ b/xtables.c
@@ -730,6 +730,17 @@
return compatible_revision(name, revision, afinfo->so_rev_target);
}
+static void xtables_check_options(const char *name, const struct option *opt)
+{
+ for (; opt->name != NULL; ++opt)
+ if (opt->val < 0 || opt->val >= XT_OPTION_OFFSET_SCALE) {
+ fprintf(stderr, "%s: Extension %s uses invalid "
+ "option value %d\n",xt_params->program_name,
+ name, opt->val);
+ exit(1);
+ }
+}
+
void xtables_register_match(struct xtables_match *me)
{
struct xtables_match **i, *old;
@@ -760,6 +771,9 @@
exit(1);
}
+ if (me->extra_opts != NULL)
+ xtables_check_options(me->name, me->extra_opts);
+
/* ignore not interested match */
if (me->family != afinfo->family && me->family != AF_UNSPEC)
return;
@@ -845,6 +859,9 @@
exit(1);
}
+ if (me->extra_opts != NULL)
+ xtables_check_options(me->name, me->extra_opts);
+
/* ignore not interested target */
if (me->family != afinfo->family && me->family != AF_UNSPEC)
return;