scsi: target: iscsi: Control authentication per ACL

Add acls/{ACL}/attrib/authentication attribute that controls authentication
for particular ACL. By default, this attribute inherits a value of the
authentication attribute of the target port group to keep backward
compatibility.

Authentication attribute has 3 states:

 "0" - authentication is turned off for this ACL

 "1" - authentication is required for this ACL

 "-1" - authentication is inherited from TPG

Link: https://lore.kernel.org/r/20220523095905.26070-4-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/iscsi/iscsi_target_configfs.c

@@ -314,6 +314,36 @@ ISCSI_NACL_ATTR(random_datain_pdu_offsets);
 ISCSI_NACL_ATTR(random_datain_seq_offsets);
 ISCSI_NACL_ATTR(random_r2t_offsets);
 
+static ssize_t iscsi_nacl_attrib_authentication_show(struct config_item *item,
+		char *page)
+{
+	struct se_node_acl *se_nacl = attrib_to_nacl(item);
+	struct iscsi_node_acl *nacl = to_iscsi_nacl(se_nacl);
+
+	return sprintf(page, "%d\n", nacl->node_attrib.authentication);
+}
+
+static ssize_t iscsi_nacl_attrib_authentication_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_node_acl *se_nacl = attrib_to_nacl(item);
+	struct iscsi_node_acl *nacl = to_iscsi_nacl(se_nacl);
+	s32 val;
+	int ret;
+
+	ret = kstrtos32(page, 0, &val);
+	if (ret)
+		return ret;
+	if (val != 0 && val != 1 && val != NA_AUTHENTICATION_INHERITED)
+		return -EINVAL;
+
+	nacl->node_attrib.authentication = val;
+
+	return count;
+}
+
+CONFIGFS_ATTR(iscsi_nacl_attrib_, authentication);
+
 static struct configfs_attribute *lio_target_nacl_attrib_attrs[] = {
 	&iscsi_nacl_attrib_attr_dataout_timeout,
 	&iscsi_nacl_attrib_attr_dataout_timeout_retries,
@@ -323,6 +353,7 @@ static struct configfs_attribute *lio_target_nacl_attrib_attrs[] = {
 	&iscsi_nacl_attrib_attr_random_datain_pdu_offsets,
 	&iscsi_nacl_attrib_attr_random_datain_seq_offsets,
 	&iscsi_nacl_attrib_attr_random_r2t_offsets,
+	&iscsi_nacl_attrib_attr_authentication,
 	NULL,
 };
 

drivers/target/iscsi/iscsi_target_nego.c

@@ -813,6 +813,7 @@ static int iscsi_target_do_authentication(
 
 static bool iscsi_conn_auth_required(struct iscsit_conn *conn)
 {
+	struct iscsi_node_acl *nacl;
 	struct se_node_acl *se_nacl;
 
 	if (conn->sess->sess_ops->SessionType) {
@@ -839,7 +840,12 @@ static bool iscsi_conn_auth_required(struct iscsit_conn *conn)
 
 	pr_debug("Known ACL %s is trying to connect\n",
 		 se_nacl->initiatorname);
-	return conn->tpg->tpg_attrib.authentication;
+
+	nacl = to_iscsi_nacl(se_nacl);
+	if (nacl->node_attrib.authentication == NA_AUTHENTICATION_INHERITED)
+		return conn->tpg->tpg_attrib.authentication;
+
+	return nacl->node_attrib.authentication;
 }
 
 static int iscsi_target_handle_csg_zero(

drivers/target/iscsi/iscsi_target_nodeattrib.c

@@ -30,6 +30,7 @@ void iscsit_set_default_node_attribues(
 {
 	struct iscsi_node_attrib *a = &acl->node_attrib;
 
+	a->authentication = NA_AUTHENTICATION_INHERITED;
 	a->dataout_timeout = NA_DATAOUT_TIMEOUT;
 	a->dataout_timeout_retries = NA_DATAOUT_TIMEOUT_RETRIES;
 	a->nopin_timeout = NA_NOPIN_TIMEOUT;

include/target/iscsi/iscsi_target_core.h

@@ -26,6 +26,7 @@ struct sock;
 #define ISCSI_RX_THREAD_NAME		"iscsi_trx"
 #define ISCSI_TX_THREAD_NAME		"iscsi_ttx"
 #define ISCSI_IQN_LEN			224
+#define NA_AUTHENTICATION_INHERITED	-1
 
 /* struct iscsi_node_attrib sanity values */
 #define NA_DATAOUT_TIMEOUT		3
@@ -715,6 +716,7 @@ struct iscsi_login {
 } ____cacheline_aligned;
 
 struct iscsi_node_attrib {
+	s32			authentication;
 	u32			dataout_timeout;
 	u32			dataout_timeout_retries;
 	u32			default_erl;