payload: accept ethertype in hexadecimal

You can use the symbols ip, ip6, arp and vlan, or alternatively
the ethertype protocol number.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 21 insertions, 1 deletions

diff --git a/src/payload.c b/src/payload.c
index bcbc0d43..942bc857 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -930,6 +930,24 @@ static const struct symbol_table ethertype_tbl = {
 	},
 };
 
+static struct error_record *ethertype_parse(const struct expr *sym,
+					    struct expr **res)
+{
+	struct error_record *erec;
+
+	erec = sym->dtype->basetype->parse(sym, res);
+	if (erec != NULL)
+		return erec;
+	if (*res)
+		return NULL;
+	return symbolic_constant_parse(sym, &ethertype_tbl, res);
+}
+
+static void ethertype_print(const struct expr *expr)
+{
+	return symbolic_constant_print(&ethertype_tbl, expr);
+}
+
 const struct datatype ethertype_type = {
 	.type		= TYPE_ETHERTYPE,
 	.name		= "ethertype",
@@ -937,7 +955,9 @@ const struct datatype ethertype_type = {
 	.byteorder	= BYTEORDER_HOST_ENDIAN,
 	.size		= 2 * BITS_PER_BYTE,
 	.basetype	= &integer_type,
-	.sym_tbl	= &ethertype_tbl,
+	.basefmt	= "0x%.4Zx",
+	.print		= ethertype_print,
+	.parse		= ethertype_parse,
 };
 
 #define ETHHDR_TEMPLATE(__name, __dtype, __member) \