osf: add ttl option support

Add support for ttl option in "osf" expression. Example:

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

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

1 files changed, 22 insertions, 2 deletions

diff --git a/src/osf.c b/src/osf.c
index 85c95739..b98d1650 100644
--- a/src/osf.c
+++ b/src/osf.c
@@ -5,13 +5,31 @@
 #include <osf.h>
 #include <json.h>
 
+static const char *osf_ttl_int_to_str(const uint8_t ttl)
+{
+	if (ttl == 1)
+		return "ttl loose ";
+	else if (ttl == 2)
+		return "ttl skip ";
+
+	return "";
+}
+
 static void osf_expr_print(const struct expr *expr, struct output_ctx *octx)
 {
-	nft_print(octx, "osf name");
+	const char *ttl_str = osf_ttl_int_to_str(expr->osf.ttl);
+
+	nft_print(octx, "osf %sname", ttl_str);
 }
 
 static void osf_expr_clone(struct expr *new, const struct expr *expr)
 {
+	new->osf.ttl = expr->osf.ttl;
+}
+
+static bool osf_expr_cmp(const struct expr *e1, const struct expr *e2)
+{
+	return e1->osf.ttl == e2->osf.ttl;
 }
 
 static const struct expr_ops osf_expr_ops = {
@@ -19,10 +37,11 @@ static const struct expr_ops osf_expr_ops = {
 	.name		= "osf",
 	.print		= osf_expr_print,
 	.clone		= osf_expr_clone,
+	.cmp		= osf_expr_cmp,
 	.json		= osf_expr_json,
 };
 
-struct expr *osf_expr_alloc(const struct location *loc)
+struct expr *osf_expr_alloc(const struct location *loc, const uint8_t ttl)
 {
 	unsigned int len = NFT_OSF_MAXGENRELEN * BITS_PER_BYTE;
 	const struct datatype *type = &string_type;
@@ -30,6 +49,7 @@ struct expr *osf_expr_alloc(const struct location *loc)
 
 	expr = expr_alloc(loc, &osf_expr_ops, type,
 			  BYTEORDER_HOST_ENDIAN, len);
+	expr->osf.ttl = ttl;
 
 	return expr;
 }