fib_rules: fix suppressor names and default values

This change brings the suppressor attribute names into line; it also changes
the data types to provide a more consistent interface.

While -1 indicates that the suppressor is not enabled, values >= 0 for
suppress_prefixlen or suppress_ifgroup  reject routing decisions violating the
constraint.

This changes the previously presented behaviour of suppress_prefixlen, where a
prefix length _less_ than the attribute value was rejected. After this change,
a prefix length less than *or* equal to the value is considered a violation of
the rule constraint.

It also changes the default values for default and newly added rules (disabling
any suppression for those).

Signed-off-by: Stefan Tomanek <stefan.tomanek@wertarbyte.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index d13c461b..9d0fcbaa 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -19,7 +19,7 @@
 	u32			flags;
 	u32			table;
 	int			suppress_ifgroup;
-	u8			table_prefixlen_min;
+	int			suppress_prefixlen;
 	u8			action;
 	u32			target;
 	struct fib_rule __rcu	*ctarget;
@@ -84,7 +84,7 @@
 	[FRA_FWMARK]	= { .type = NLA_U32 }, \
 	[FRA_FWMASK]	= { .type = NLA_U32 }, \
 	[FRA_TABLE]     = { .type = NLA_U32 }, \
-	[FRA_TABLE_PREFIXLEN_MIN] = { .type = NLA_U8 }, \
+	[FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 }, \
 	[FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, \
 	[FRA_GOTO]	= { .type = NLA_U32 }