[PATCH 5/9] nvme-keyring: add nvme_tls_psk_refresh()

[Hannes Reinecke <hare@kernel.org>]

Add a function to refresh a generated PSK in the specified keyring.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 drivers/nvme/common/keyring.c | 64 +++++++++++++++++++++++++++++++++++
 include/linux/nvme-keyring.h  |  9 +++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/nvme/common/keyring.c b/drivers/nvme/common/keyring.c
index ed5167f942d8..8cb253fcd586 100644
--- a/drivers/nvme/common/keyring.c
+++ b/drivers/nvme/common/keyring.c
@@ -124,6 +124,70 @@ static struct key *nvme_tls_psk_lookup(struct key *keyring,
 	return key_ref_to_ptr(keyref);
 }
 
+/**
+ * nvme_tls_psk_refresh - Refresh TLS PSK
+ * @keyring: Keyring holding the TLS PSK
+ * @hostnqn: Host NQN to use
+ * @subnqn: Subsystem NQN to use
+ * @hmac_id: Hash function identifier
+ * @data: TLS PSK key material
+ * @data_len: Length of @data
+ * @digest: TLS PSK digest
+ *
+ * Refresh a generated version 1 TLS PSK with the identity generated
+ * from @hmac_id, @hostnqn, @subnqn, and @digest in the keyring given
+ * by @keyring.
+ *
+ * Returns the updated key success or an error pointer otherwise.
+ */
+struct key *nvme_tls_psk_refresh(struct key *keyring,
+		const char *hostnqn, const char *subnqn, u8 hmac_id,
+		u8 *data, size_t data_len, const char *digest)
+{
+	key_perm_t keyperm =
+		KEY_POS_SEARCH | KEY_POS_VIEW | KEY_POS_READ |
+		KEY_POS_WRITE | KEY_POS_LINK | KEY_POS_SETATTR |
+		KEY_USR_SEARCH | KEY_USR_VIEW | KEY_USR_READ;
+	char *identity;
+	key_ref_t keyref;
+	key_serial_t keyring_id;
+	struct key *key;
+
+	if (!hostnqn || !subnqn || !data || !data_len)
+		return ERR_PTR(-EINVAL);
+
+	identity = kasprintf(GFP_KERNEL, "NVMe1G%02d %s %s %s",
+		 hmac_id, hostnqn, subnqn, digest);
+	if (!identity)
+		return ERR_PTR(-ENOMEM);
+
+	if (!keyring)
+		keyring = nvme_keyring;
+	keyring_id = key_serial(keyring);
+	pr_debug("keyring %x refresh tls psk '%s'\n",
+		 keyring_id, identity);
+	keyref = key_create_or_update(make_key_ref(keyring, true),
+				"psk", identity, data, data_len,
+				keyperm, KEY_ALLOC_NOT_IN_QUOTA |
+				      KEY_ALLOC_BUILT_IN |
+				      KEY_ALLOC_BYPASS_RESTRICTION);
+	if (IS_ERR(keyref)) {
+		pr_debug("refresh tls psk '%s' failed, error %ld\n",
+			 identity, PTR_ERR(keyref));
+		kfree(identity);
+		return ERR_PTR(-ENOKEY);
+	}
+	kfree(identity);
+	/*
+	 * Set the default timeout to 1 hour
+	 * as suggested in TP8018.
+	 */
+	key = key_ref_to_ptr(keyref);
+	key_set_timeout(key, 3600);
+	return key;
+}
+EXPORT_SYMBOL_GPL(nvme_tls_psk_refresh);
+
 /*
  * NVMe PSK priority list
  *
diff --git a/include/linux/nvme-keyring.h b/include/linux/nvme-keyring.h
index 19d2b256180f..351a02b1bbc3 100644
--- a/include/linux/nvme-keyring.h
+++ b/include/linux/nvme-keyring.h
@@ -8,6 +8,9 @@
 
 #if IS_ENABLED(CONFIG_NVME_KEYRING)
 
+struct key *nvme_tls_psk_refresh(struct key *keyring,
+		const char *hostnqn, const char *subnqn, u8 hmac_id,
+		u8 *data, size_t data_len, const char *digest);
 key_serial_t nvme_tls_psk_default(struct key *keyring,
 		const char *hostnqn, const char *subnqn);
 
@@ -15,6 +18,12 @@ key_serial_t nvme_keyring_id(void);
 struct key *nvme_tls_key_lookup(key_serial_t key_id);
 #else
 
+static struct key *nvme_tls_psk_refresh(struct key *keyring,
+		const char *hostnqn, char *subnqn, u8 hmac_id,
+		u8 *data, size_t data_len, const char *digest)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
 static inline key_serial_t nvme_tls_psk_default(struct key *keyring,
 		const char *hostnqn, const char *subnqn)
 {
-- 
2.35.3