nvme-keyring: implement nvme_tls_psk_default()

Implement a function to select the preferred PSK for TLS.
A 'retained' PSK should be preferred over a 'generated' PSK,
and SHA-384 should be preferred to SHA-256.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/nvme-keyring.h b/include/linux/nvme-keyring.h
index 32bd264a71e6..4efea9dd967c 100644
--- a/include/linux/nvme-keyring.h
+++ b/include/linux/nvme-keyring.h
@@ -8,12 +8,20 @@
 
 #ifdef CONFIG_NVME_KEYRING
 
+key_serial_t nvme_tls_psk_default(struct key *keyring,
+		const char *hostnqn, const char *subnqn);
+
 key_serial_t nvme_keyring_id(void);
 int nvme_keyring_init(void);
 void nvme_keyring_exit(void);
 
 #else
 
+static inline key_serial_t nvme_tls_psk_default(struct key *keyring,
+		const char *hostnqn, const char *subnqn)
+{
+	return 0;
+}
 static inline key_serial_t nvme_keyring_id(void)
 {
 	return 0;