[SCSI] iscsi: add transport end point callbacks

add transport end point callbacks so iscsi drivers that cannot connect
from userspace, like iscsi tcp, using sockets do not have to
implement their own socket infrastructure.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Author: Or Gerlitz

drivers/scsi/iscsi_tcp.c

@@ -1975,7 +1975,7 @@ iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 
 static int
 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
-		    struct iscsi_cls_conn *cls_conn, uint32_t transport_fd,
+		    struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 		    int is_leading)
 {
 	struct iscsi_conn *conn = cls_conn->dd_data;
@@ -1985,7 +1985,7 @@ iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 	int err;
 
 	/* lookup for existing socket */
-	sock = sockfd_lookup(transport_fd, &err);
+	sock = sockfd_lookup((int)transport_eph, &err);
 	if (!sock) {
 		printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
 		return -EEXIST;

drivers/scsi/scsi_transport_iscsi.c

@@ -928,6 +928,40 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
 	return err;
 }
 
+static int
+iscsi_if_transport_ep(struct iscsi_transport *transport,
+		      struct iscsi_uevent *ev, int msg_type)
+{
+	struct sockaddr *dst_addr;
+	int rc = 0;
+
+	switch (msg_type) {
+	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
+		if (!transport->ep_connect)
+			return -EINVAL;
+
+		dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
+		rc = transport->ep_connect(dst_addr,
+					   ev->u.ep_connect.non_blocking,
+					   &ev->r.ep_connect_ret.handle);
+		break;
+	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
+		if (!transport->ep_poll)
+			return -EINVAL;
+
+		ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
+						   ev->u.ep_poll.timeout_ms);
+		break;
+	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
+		if (!transport->ep_disconnect)
+			return -EINVAL;
+
+		transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
+		break;
+	}
+	return rc;
+}
+
 static int
 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
@@ -974,7 +1008,7 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 		if (session && conn)
 			ev->r.retcode =	transport->bind_conn(session, conn,
-					ev->u.b_conn.transport_fd,
+					ev->u.b_conn.transport_eph,
 					ev->u.b_conn.is_leading);
 		else
 			err = -EINVAL;
@@ -1009,6 +1043,11 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case ISCSI_UEVENT_GET_STATS:
 		err = iscsi_if_get_stats(transport, nlh);
 		break;
+	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
+	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
+	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
+		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
+		break;
 	default:
 		err = -EINVAL;
 		break;

include/scsi/iscsi_if.h

@@ -43,6 +43,10 @@ enum iscsi_uevent_e {
 	ISCSI_UEVENT_GET_STATS		= UEVENT_BASE + 10,
 	ISCSI_UEVENT_GET_PARAM		= UEVENT_BASE + 11,
 
+	ISCSI_UEVENT_TRANSPORT_EP_CONNECT	= UEVENT_BASE + 12,
+	ISCSI_UEVENT_TRANSPORT_EP_POLL		= UEVENT_BASE + 13,
+	ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT	= UEVENT_BASE + 14,
+
 	/* up events */
 	ISCSI_KEVENT_RECV_PDU		= KEVENT_BASE + 1,
 	ISCSI_KEVENT_CONN_ERROR		= KEVENT_BASE + 2,
@@ -69,7 +73,7 @@ struct iscsi_uevent {
 		struct msg_bind_conn {
 			uint32_t	sid;
 			uint32_t	cid;
-			uint32_t	transport_fd;
+			uint64_t	transport_eph;
 			uint32_t	is_leading;
 		} b_conn;
 		struct msg_destroy_conn {
@@ -102,6 +106,16 @@ struct iscsi_uevent {
 			uint32_t	sid;
 			uint32_t	cid;
 		} get_stats;
+		struct msg_transport_connect {
+			uint32_t	non_blocking;
+		} ep_connect;
+		struct msg_transport_poll {
+			uint64_t	ep_handle;
+			uint32_t	timeout_ms;
+		} ep_poll;
+		struct msg_transport_disconnect {
+			uint64_t	ep_handle;
+		} ep_disconnect;
 	} u;
 	union {
 		/* messages k -> u */
@@ -124,6 +138,9 @@ struct iscsi_uevent {
 			uint32_t	cid;
 			uint32_t	error; /* enum iscsi_err */
 		} connerror;
+		struct msg_transport_connect_ret {
+			uint64_t	handle;
+		} ep_connect_ret;
 	} r;
 } __attribute__ ((aligned (sizeof(uint64_t))));
 

include/scsi/scsi_transport_iscsi.h

@@ -88,7 +88,7 @@ struct iscsi_transport {
 				uint32_t cid);
 	int (*bind_conn) (struct iscsi_cls_session *session,
 			  struct iscsi_cls_conn *cls_conn,
-			  uint32_t transport_fd, int is_leading);
+			  uint64_t transport_eph, int is_leading);
 	int (*start_conn) (struct iscsi_cls_conn *conn);
 	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
@@ -119,6 +119,10 @@ struct iscsi_transport {
 	int (*xmit_mgmt_task) (struct iscsi_conn *conn,
 			       struct iscsi_mgmt_task *mtask);
 	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
+	int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
+			   uint64_t *ep_handle);
+	int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
+	void (*ep_disconnect) (uint64_t ep_handle);
 };
 
 /*