iscsi-target: Initial traditional TCP conversion to iscsit_transport

This patch performs the initial conversion of existing traditional iscsi
to use iscsit_transport API callers.  This includes:

- iscsi-np cleanups for iscsit_transport_type
- Add iscsi-np transport calls w/ ->iscsit_setup_up() and ->iscsit_free_np()
- Convert login thread process context to use ->iscsit_accept_np() for
  connections with pre-allocated struct iscsi_conn
- Convert existing socket accept code to iscsit_accept_np()
- Convert login RX/TX callers to use ->iscsit_get_login_rx() and
  ->iscsit_put_login_tx() to exchange request/response PDUs
- Convert existing socket login RX/TX calls into iscsit_get_login_rx()
  and iscsit_put_login_tx()
- Change iscsit_close_connection() to invoke ->iscsit_free_conn() +
  iscsit_put_transport() calls.
- Add iscsit_register_transport() + iscsit_unregister_transport() calls
  to module init/exit

v4 changes:

- Add missing iscsit_put_transport() call in iscsi_target_setup_login_socket()
  failure case

v2 changes:

- Update module init/exit to use register_transport() + unregister_transport()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target.c

@@ -49,6 +49,8 @@
 #include "iscsi_target_device.h"
 #include "iscsi_target_stat.h"
 
+#include <target/iscsi/iscsi_transport.h>
+
 static LIST_HEAD(g_tiqn_list);
 static LIST_HEAD(g_np_list);
 static DEFINE_SPINLOCK(tiqn_lock);
@@ -401,8 +403,7 @@ struct iscsi_np *iscsit_add_np(
 	spin_unlock_bh(&np_lock);
 
 	pr_debug("CORE[0] - Added Network Portal: %s:%hu on %s\n",
-		np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
-		"TCP" : "SCTP");
+		np->np_ip, np->np_port, np->np_transport->name);
 
 	return np;
 }
@@ -441,11 +442,10 @@ int iscsit_reset_np_thread(
 	return 0;
 }
 
-static int iscsit_del_np_comm(struct iscsi_np *np)
+static void iscsit_free_np(struct iscsi_np *np)
 {
 	if (np->np_socket)
 		sock_release(np->np_socket);
-	return 0;
 }
 
 int iscsit_del_np(struct iscsi_np *np)
@@ -467,20 +467,32 @@ int iscsit_del_np(struct iscsi_np *np)
 		send_sig(SIGINT, np->np_thread, 1);
 		kthread_stop(np->np_thread);
 	}
-	iscsit_del_np_comm(np);
+
+	np->np_transport->iscsit_free_np(np);
 
 	spin_lock_bh(&np_lock);
 	list_del(&np->np_list);
 	spin_unlock_bh(&np_lock);
 
 	pr_debug("CORE[0] - Removed Network Portal: %s:%hu on %s\n",
-		np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
-		"TCP" : "SCTP");
+		np->np_ip, np->np_port, np->np_transport->name);
 
+	iscsit_put_transport(np->np_transport);
 	kfree(np);
 	return 0;
 }
 
+static struct iscsit_transport iscsi_target_transport = {
+	.name			= "iSCSI/TCP",
+	.transport_type		= ISCSI_TCP,
+	.owner			= NULL,
+	.iscsit_setup_np	= iscsit_setup_np,
+	.iscsit_accept_np	= iscsit_accept_np,
+	.iscsit_free_np		= iscsit_free_np,
+	.iscsit_get_login_rx	= iscsit_get_login_rx,
+	.iscsit_put_login_tx	= iscsit_put_login_tx,
+};
+
 static int __init iscsi_target_init_module(void)
 {
 	int ret = 0;
@@ -557,6 +569,8 @@ static int __init iscsi_target_init_module(void)
 		goto ooo_out;
 	}
 
+	iscsit_register_transport(&iscsi_target_transport);
+
 	if (iscsit_load_discovery_tpg() < 0)
 		goto r2t_out;
 
@@ -587,6 +601,7 @@ static void __exit iscsi_target_cleanup_module(void)
 	iscsi_deallocate_thread_sets();
 	iscsi_thread_set_free();
 	iscsit_release_discovery_tpg();
+	iscsit_unregister_transport(&iscsi_target_transport);
 	kmem_cache_destroy(lio_cmd_cache);
 	kmem_cache_destroy(lio_qr_cache);
 	kmem_cache_destroy(lio_dr_cache);
@@ -4053,6 +4068,12 @@ int iscsit_close_connection(
 
 	if (conn->sock)
 		sock_release(conn->sock);
+
+	if (conn->conn_transport->iscsit_free_conn)
+		conn->conn_transport->iscsit_free_conn(conn);
+
+	iscsit_put_transport(conn->conn_transport);
+
 	conn->thread_set = NULL;
 
 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");

drivers/target/iscsi/iscsi_target_core.h

@@ -60,7 +60,7 @@
 
 #define ISCSI_IOV_DATA_BUFFER		5
 
-enum tpg_np_network_transport_table {
+enum iscsit_transport_type {
 	ISCSI_TCP				= 0,
 	ISCSI_SCTP_TCP				= 1,
 	ISCSI_SCTP_UDP				= 2,
@@ -503,6 +503,7 @@ struct iscsi_conn {
 	u16			login_port;
 	u16			local_port;
 	int			net_size;
+	int			login_family;
 	u32			auth_id;
 	u32			conn_flags;
 	/* Used for iscsi_tx_login_rsp() */
@@ -562,9 +563,12 @@ struct iscsi_conn {
 	struct list_head	immed_queue_list;
 	struct list_head	response_queue_list;
 	struct iscsi_conn_ops	*conn_ops;
+	struct iscsi_login	*conn_login;
+	struct iscsit_transport *conn_transport;
 	struct iscsi_param_list	*param_list;
 	/* Used for per connection auth state machine */
 	void			*auth_protocol;
+	void			*context;
 	struct iscsi_login_thread_s *login_thread;
 	struct iscsi_portal_group *tpg;
 	/* Pointer to parent session */
@@ -663,17 +667,20 @@ struct iscsi_login {
 	u8 first_request;
 	u8 version_min;
 	u8 version_max;
+	u8 login_complete;
+	u8 login_failed;
 	char isid[6];
 	u32 cmd_sn;
 	itt_t init_task_tag;
 	u32 initial_exp_statsn;
 	u32 rsp_length;
 	u16 cid;
 	u16 tsih;
-	char *req;
-	char *rsp;
+	char req[ISCSI_HDR_LEN];
+	char rsp[ISCSI_HDR_LEN];
 	char *req_buf;
 	char *rsp_buf;
+	struct iscsi_conn *conn;
 } ____cacheline_aligned;
 
 struct iscsi_node_attrib {
@@ -754,6 +761,8 @@ struct iscsi_np {
 	struct task_struct	*np_thread;
 	struct timer_list	np_login_timer;
 	struct iscsi_portal_group *np_login_tpg;
+	void			*np_context;
+	struct iscsit_transport *np_transport;
 	struct list_head	np_list;
 } ____cacheline_aligned;