osf: add version fingerprint support

Add support for version fingerprint in "osf" expression. Example:

table ip foo {
	chain bar {
		type filter hook input priority filter; policy accept;
		osf ttl skip name "Linux"
		osf ttl skip version "Linux:4.20"
	}
}

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/expression.h b/include/expression.h
index 6d72f64c..6416ac09 100644
--- a/include/expression.h
+++ b/include/expression.h
@@ -350,6 +350,7 @@ struct expr {
 		struct {
 			/* EXPR_OSF */
 			uint8_t			ttl;
+			uint32_t		flags;
 		} osf;
 	};
 };