scsi: zfcp: report FC Endpoint Security in sysfs

Add an interface to read Fibre Channel Endpoint Security information of FCP
channels and their connections to FC remote ports. It comes in the form of
new sysfs attributes that are attached to the CCW device representing the
FCP device and its zfcp port objects.

The read-only sysfs attribute "fc_security" of a CCW device representing a
FCP device shows the FC Endpoint Security capabilities of the device.
Possible values are: "unknown", "unsupported", "none", or a comma-
separated list of one or more mnemonics and/or one hexadecimal value
representing the supported FC Endpoint Security:

  Authentication: Authentication supported
  Encryption    : Encryption supported

The read-only sysfs attribute "fc_security" of a zfcp port object shows the
FC Endpoint Security used on the connection between its parent FCP device
and the FC remote port. Possible values are: "unknown", "unsupported",
"none", or a mnemonic or hexadecimal value representing the FC Endpoint
Security used:

  Authentication: Connection has been authenticated
  Encryption    : Connection is encrypted

Both sysfs attributes may return hexadecimal values instead of mnemonics,
if the mnemonic lookup table does not contain an entry for the FC Endpoint
Security reported by the FCP device.

Link: https://lore.kernel.org/r/20200312174505.51294-7-maier@linux.ibm.com
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 69 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 494b9fe9cc94..45d53166d0d1 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -4,7 +4,7 @@
  *
  * sysfs attributes.
  *
- * Copyright IBM Corp. 2008, 2010
+ * Copyright IBM Corp. 2008, 2020
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -370,6 +370,42 @@ static ZFCP_DEV_ATTR(adapter, diag_max_age, 0644,
 		     zfcp_sysfs_adapter_diag_max_age_show,
 		     zfcp_sysfs_adapter_diag_max_age_store);
 
+static ssize_t zfcp_sysfs_adapter_fc_security_show(
+	struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct ccw_device *cdev = to_ccwdev(dev);
+	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
+	unsigned int status;
+	int i;
+
+	if (!adapter)
+		return -ENODEV;
+
+	/*
+	 * Adapter status COMMON_OPEN implies xconf data and xport data
+	 * was done. Adapter FC Endpoint Security capability remains
+	 * unchanged in case of COMMON_ERP_FAILED (e.g. due to local link
+	 * down).
+	 */
+	status = atomic_read(&adapter->status);
+	if (0 == (status & ZFCP_STATUS_COMMON_OPEN))
+		i = sprintf(buf, "unknown\n");
+	else if (!(adapter->adapter_features & FSF_FEATURE_FC_SECURITY))
+		i = sprintf(buf, "unsupported\n");
+	else {
+		i = zfcp_fsf_scnprint_fc_security(
+			buf, PAGE_SIZE - 1, adapter->fc_security_algorithms,
+			ZFCP_FSF_PRINT_FMT_LIST);
+		i += scnprintf(buf + i, PAGE_SIZE - i, "\n");
+	}
+
+	zfcp_ccw_adapter_put(adapter);
+	return i;
+}
+static ZFCP_DEV_ATTR(adapter, fc_security, S_IRUGO,
+		     zfcp_sysfs_adapter_fc_security_show,
+		     NULL);
+
 static struct attribute *zfcp_adapter_attrs[] = {
 	&dev_attr_adapter_failed.attr,
 	&dev_attr_adapter_in_recovery.attr,
@@ -383,6 +419,7 @@ static struct attribute *zfcp_adapter_attrs[] = {
 	&dev_attr_adapter_status.attr,
 	&dev_attr_adapter_hardware_version.attr,
 	&dev_attr_adapter_diag_max_age.attr,
+	&dev_attr_adapter_fc_security.attr,
 	NULL
 };
 
@@ -426,6 +463,36 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
 }
 static DEVICE_ATTR(unit_remove, S_IWUSR, NULL, zfcp_sysfs_unit_remove_store);
 
+static ssize_t zfcp_sysfs_port_fc_security_show(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
+{
+	struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
+	struct zfcp_adapter *adapter = port->adapter;
+	unsigned int status = atomic_read(&port->status);
+	int i;
+
+	if (0 == (status & ZFCP_STATUS_COMMON_OPEN) ||
+	    0 == (status & ZFCP_STATUS_COMMON_UNBLOCKED) ||
+	    0 == (status & ZFCP_STATUS_PORT_PHYS_OPEN) ||
+	    0 != (status & ZFCP_STATUS_COMMON_ERP_FAILED) ||
+	    0 != (status & ZFCP_STATUS_COMMON_ACCESS_BOXED))
+		i = sprintf(buf, "unknown\n");
+	else if (!(adapter->adapter_features & FSF_FEATURE_FC_SECURITY))
+		i = sprintf(buf, "unsupported\n");
+	else {
+		i = zfcp_fsf_scnprint_fc_security(
+			buf, PAGE_SIZE - 1, port->connection_info,
+			ZFCP_FSF_PRINT_FMT_SINGLEITEM);
+		i += scnprintf(buf + i, PAGE_SIZE - i, "\n");
+	}
+
+	return i;
+}
+static ZFCP_DEV_ATTR(port, fc_security, S_IRUGO,
+		     zfcp_sysfs_port_fc_security_show,
+		     NULL);
+
 static struct attribute *zfcp_port_attrs[] = {
 	&dev_attr_unit_add.attr,
 	&dev_attr_unit_remove.attr,
@@ -433,6 +500,7 @@ static struct attribute *zfcp_port_attrs[] = {
 	&dev_attr_port_in_recovery.attr,
 	&dev_attr_port_status.attr,
 	&dev_attr_port_access_denied.attr,
+	&dev_attr_port_fc_security.attr,
 	NULL
 };
 static struct attribute_group zfcp_port_attr_group = {