[PATCH 01/18] nvme-keyring: register '.nvme' keyring

[Hannes Reinecke <hare@suse.de>]

Register a '.nvme' keyring to hold keys for TLS and DH-HMAC-CHAP.
We need a separate keyring as for NVMe the might not be a userspace
process attached (eg during reconnect), and so the use of a session
keyring or any other process-related keyrings might not be possible.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/common/Makefile  |  2 +-
 drivers/nvme/common/keyring.c | 36 +++++++++++++++++++++++++++++++++++
 drivers/nvme/host/core.c      | 10 +++++++++-
 include/linux/nvme-keyring.h  | 12 ++++++++++++
 4 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 drivers/nvme/common/keyring.c
 create mode 100644 include/linux/nvme-keyring.h

diff --git a/drivers/nvme/common/Makefile b/drivers/nvme/common/Makefile
index 720c625b8a52..c4e3b312d2cc 100644
--- a/drivers/nvme/common/Makefile
+++ b/drivers/nvme/common/Makefile
@@ -4,4 +4,4 @@ ccflags-y			+= -I$(src)
 
 obj-$(CONFIG_NVME_COMMON)	+= nvme-common.o
 
-nvme-common-y			+= auth.o
+nvme-common-y			+= auth.o keyring.o
diff --git a/drivers/nvme/common/keyring.c b/drivers/nvme/common/keyring.c
new file mode 100644
index 000000000000..3a6e8a0b38e2
--- /dev/null
+++ b/drivers/nvme/common/keyring.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Hannes Reinecke, SUSE Linux
+ */
+
+#include <linux/module.h>
+#include <linux/nvme.h>
+#include <linux/seq_file.h>
+#include <linux/key-type.h>
+#include <keys/user-type.h>
+
+static struct key *nvme_keyring;
+
+int nvme_keyring_init(void)
+{
+	int err;
+
+	nvme_keyring = keyring_alloc(".nvme",
+				     GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+				     current_cred(),
+				     (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				     (KEY_USR_ALL & ~KEY_USR_SETATTR),
+				     KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+	if (IS_ERR(nvme_keyring))
+		return PTR_ERR(nvme_keyring);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_keyring_init);
+
+void nvme_keyring_exit(void)
+{
+	key_revoke(nvme_keyring);
+	key_put(nvme_keyring);
+}
+EXPORT_SYMBOL_GPL(nvme_keyring_exit);
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d4be525f8100..839bc7587f54 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -25,6 +25,7 @@
 #include "nvme.h"
 #include "fabrics.h"
 #include <linux/nvme-auth.h>
+#include <linux/nvme-keyring.h>
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
@@ -5415,11 +5416,17 @@ static int __init nvme_core_init(void)
 		goto unregister_generic_ns;
 	}
 
-	result = nvme_init_auth();
+	result = nvme_keyring_init();
 	if (result)
 		goto destroy_ns_chr;
+
+	result = nvme_init_auth();
+	if (result)
+		goto keyring_exit;
 	return 0;
 
+keyring_exit:
+	nvme_keyring_exit();
 destroy_ns_chr:
 	class_destroy(nvme_ns_chr_class);
 unregister_generic_ns:
@@ -5443,6 +5450,7 @@ static int __init nvme_core_init(void)
 static void __exit nvme_core_exit(void)
 {
 	nvme_exit_auth();
+	nvme_keyring_exit();
 	class_destroy(nvme_ns_chr_class);
 	class_destroy(nvme_subsys_class);
 	class_destroy(nvme_class);
diff --git a/include/linux/nvme-keyring.h b/include/linux/nvme-keyring.h
new file mode 100644
index 000000000000..a875c06cc922
--- /dev/null
+++ b/include/linux/nvme-keyring.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Hannes Reinecke, SUSE Software Solutions
+ */
+
+#ifndef _NVME_KEYRING_H
+#define _NVME_KEYRING_H
+
+int nvme_keyring_init(void);
+void nvme_keyring_exit(void);
+
+#endif
-- 
2.35.3