netfilter: x_tables: rectify XT_FUNCTION_MAXNAMELEN usage
There has been quite a confusion in userspace about
XT_FUNCTION_MAXNAMELEN; because struct xt_entry_match used MAX-1,
userspace would have to do an awkward MAX-2 for maximum length
checking (due to '\0'). This patch adds a new define that matches the
definition of XT_TABLE_MAXNAMELEN - being the size of the actual
struct member, not one off.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 50c8672..eeb4884 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
#define XT_FUNCTION_MAXNAMELEN 30
+#define XT_EXTENSION_MAXNAMELEN 29
#define XT_TABLE_MAXNAMELEN 32
struct xt_entry_match {
@@ -12,8 +13,7 @@
__u16 match_size;
/* Used by userspace */
- char name[XT_FUNCTION_MAXNAMELEN-1];
-
+ char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
} user;
struct {
@@ -36,8 +36,7 @@
__u16 target_size;
/* Used by userspace */
- char name[XT_FUNCTION_MAXNAMELEN-1];
-
+ char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
} user;
struct {
@@ -70,8 +69,7 @@
/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
* kernel supports, if >= revision. */
struct xt_get_revision {
- char name[XT_FUNCTION_MAXNAMELEN-1];
-
+ char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
};
@@ -291,7 +289,7 @@
struct xt_match {
struct list_head list;
- const char name[XT_FUNCTION_MAXNAMELEN-1];
+ const char name[XT_EXTENSION_MAXNAMELEN];
u_int8_t revision;
/* Return true or false: return FALSE and set *hotdrop = 1 to
@@ -330,7 +328,7 @@
struct xt_target {
struct list_head list;
- const char name[XT_FUNCTION_MAXNAMELEN-1];
+ const char name[XT_EXTENSION_MAXNAMELEN];
u_int8_t revision;
/* Returns verdict. Argument order changed since 2.6.9, as this