netlink: consistently use NLA_POLICY_EXACT_LEN()

Change places that open-code NLA_POLICY_EXACT_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Author: jmberg-intel

src/netlink.c

@@ -20,21 +20,21 @@ static struct genl_family genl_family;
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
-	[WGDEVICE_A_PUBLIC_KEY]		= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
+	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
 	[WGDEVICE_A_FLAGS]		= { .type = NLA_U32 },
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
 	[WGDEVICE_A_PEERS]		= { .type = NLA_NESTED }
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
-	[WGPEER_A_PRESHARED_KEY]			= { .type = NLA_EXACT_LEN, .len = NOISE_SYMMETRIC_KEY_LEN },
+	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(NOISE_SYMMETRIC_KEY_LEN),
 	[WGPEER_A_FLAGS]				= { .type = NLA_U32 },
 	[WGPEER_A_ENDPOINT]				= { .type = NLA_MIN_LEN, .len = sizeof(struct sockaddr) },
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
-	[WGPEER_A_LAST_HANDSHAKE_TIME]			= { .type = NLA_EXACT_LEN, .len = sizeof(struct __kernel_timespec) },
+	[WGPEER_A_LAST_HANDSHAKE_TIME]			= NLA_POLICY_EXACT_LEN(sizeof(struct __kernel_timespec)),
 	[WGPEER_A_RX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_TX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_ALLOWEDIPS]				= { .type = NLA_NESTED },