iSCSI Redirect support

This patch adds support for persistant portals like they are common
to storage arrays with different interfaces or physical members.

include/iscsi.h

@@ -231,6 +231,7 @@ enum scsi_status {
 	SCSI_STATUS_GOOD                 = 0,
 	SCSI_STATUS_CHECK_CONDITION      = 2,
 	SCSI_STATUS_RESERVATION_CONFLICT = 0x18,
+	SCSI_STATUS_REDIRECT             = 0x101,
 	SCSI_STATUS_CANCELLED            = 0x0f000000,
 	SCSI_STATUS_ERROR                = 0x0f000001
 };

lib/connect.c

@@ -35,6 +35,10 @@ struct connect_task {
 	int lun;
 };
 
+static void
+iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data _U_,
+		 void *private_data);
+
 static void
 iscsi_testunitready_cb(struct iscsi_context *iscsi, int status,
 		       void *command_data, void *private_data)
@@ -82,6 +86,14 @@ iscsi_login_cb(struct iscsi_context *iscsi, int status, void *command_data _U_,
 {
 	struct connect_task *ct = private_data;
 
+    if (status == 0x101 && iscsi->target_address) {
+		iscsi_disconnect(iscsi);
+		if (iscsi_connect_async(iscsi, iscsi->target_address, iscsi_connect_cb, iscsi->connect_data) != 0) {
+			return;
+		}
+		return;
+    }
+
 	if (status != 0) {
 		ct->cb(iscsi, SCSI_STATUS_ERROR, NULL, ct->private_data);
 		return;

lib/login.c

@@ -1088,6 +1088,13 @@ iscsi_process_login_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 		size -= len + 1;
 	}
 
+    if (status == 0x101 && iscsi->target_address) {
+		DPRINTF(iscsi,2,"target requests redirect to %s",iscsi->target_address);
+		pdu->callback(iscsi, SCSI_STATUS_REDIRECT, NULL,
+				  pdu->private_data);
+		return 0;
+    }
+
 	if (status != 0) {
 		iscsi_set_error(iscsi, "Failed to log in to target. Status: %s(%d)",
 				       login_error_str(status), status);