Patent Document

This application relates to U.S. Ser. No. 12/983,996, filed Jan. 4, 2011, which is a continuation of International Application PCT/US2008/009972, with an International Filing Date of Aug. 21, 2008, which claims the benefit of U.S. Provisional Application No. 61/080,806, filed Jul. 15, 2008, each of which is incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to storage arrays generally and, more particularly, to a method and/or apparatus for implementing a system for the injection of protocol specific errors used during the certification of components in a storage area network. 
     BACKGROUND OF THE INVENTION 
     Conventional drive arrays do not offer tools that can inject errors in an Internet Small Computer System Interface (iSCSI) protocol format. Some tools are available for other protocols, such as Fibre Channel. However, a Fibre Channel tool needs a separate analyzer, which can be expensive. 
     Such an analyzer is placed between an initiator and a target device. Using the analyzer, the Protocol Data Unit (PDU) sent from the initiator to the target will be intercepted. Some bits in the PDU stack will be modified to introduce errors in the response. One conventional approach for error injection uses a Finisar Xgig protocol analyzer (available from Finisar Corporation of Sunnyvale Calif.) between the initiator and target connectivity. 
     Disadvantages with such an error injection system include (i) extra cost involved in the Finisar Analyzer, (ii) the need for a protocol expert to locate the required bit and to vary the bit, (iii) the extra space and/or cabling needed, (iv) the inability to operate on a remote setup, (v) the need for an extra PC/Laptop to monitor and modify the Analyzer, and/or (vi) the need for tapping the data to modify and resend it may cause some delay in transmission. Even with such a hardware device, a user is not able to inject iSCSI errors. Such a device is not able to provide iSCSI jammer functions. 
     It would be desirable to implement a system for injecting protocol specific errors (e.g., iSCSI) during the certification of an iSCSI components in a storage area network. 
     SUMMARY OF THE INVENTION 
     The present invention concerns an apparatus comprising an initiator circuit and a target circuit. The initiator circuit may be configured to (i) communicate with a network through a first interface and (ii) generate testing sequences to be sent to the network. The target circuit may be configured to (i) receive the testing sequences from the network through a second network interface and (ii) respond to the testing sequences. 
     The objects, features and advantages of the present invention include providing a test system that may (i) inject errors in a PDU, (ii) be implemented without a dedicated hardware device, (iii) be implemented without a protocol expert to monitor the traffic, (iv) be implemented without a separate PC/Laptop for monitoring and modifying the PDU response, (v) be implemented without tapping the network traffic, (vi) avoid delays, (vii) automate the testing process, (viii) provide an easy to use system even if the test is executed manually, (ix) be implemented in software, (x) allow efficient feature and enhancement upgrades through software, (xi) provide design and debugging flexibility, and/or (xii) allow modification of a fault injection to stay compatible with future protocol releases and/or versions without the cost of updating hardware. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which: 
         FIG. 1  is a diagram illustrating the present invention; 
         FIG. 2  is a more detailed diagram of the present invention; and 
         FIG. 3  is a flow diagram of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The certification of an internet Small Computer System Interface (iSCSI) array controller uses tools which allow the injection of protocol. The invention concerns the introduction (or injection) of protocol specific errors in a PDU directly from within an existing component, such as an initiator. In one example, the present invention may be implemented as a software module implemented within such an existing component. The errors may be used to validate whether a target, such as an array controller, responds and recovers properly from infected erroneous data inputs. Such responses may be implemented without causing one or more of the following (i) unexpected/unaccepted errors, (ii) data corruption, (iii) loss of access to data, (iv) I/O Errors, (v) I/O timeouts, (vi) array controller hang ups and/or (vi) other errors. 
     The present invention may provide a system for injecting errors in a Protocol Data Unit (PDU) that may be performed at the PDU generation stage. The present invention may avoid tapping the data between transmissions and/or may avoid modifying the data. By using a software initiator, the protocol specific errors may be injected in the PDUs while the PDUs are being generated. 
     Referring to  FIG. 1 , a block diagram of a system  100  is shown in accordance with a preferred embodiment of the present invention. The system  100  illustrates error injection during generation of PDU. The system  100  generally comprises a block (or circuit)  102 , a block (or circuit)  104 , a block (or circuit)  106 , a block (or circuit)  108 , a block (or circuit)  109  and a network  110 . The circuit  102  may be implemented as an initiator circuit. The circuit  104  may be implemented as a host circuit. The circuit  106  may be implemented as a network device, such as a hub, regulator, switch, etc. In one example, the circuit  106  may be implemented as a fibre channel switch. An example of such a switch may be found in co-pending application Ser. No. 61/080,762, Filed Jul. 15, 2008, which is incorporated by reference in its entirety. In one example, the circuit  108  may be implemented as a storage (or drive) enclosure. In one example, the circuit  109  may be implemented as a storage (or drive) enclosure. The network  110  may be implemented as an Ethernet network. 
     The circuit  102  is shown connected to the network  110  through an IP connection (e.g., 192.168.20.21). The particular IP address may be varied for the particular network environment. Similarly, the device  104  is shown having an IP connection (e.g., 192.168.20.34) and an IP connection (e.g., 192.168.20.33). The IP address  33  and the IP address  34  may provide a multi-path connection from the device  104  to the network  110 . The device  104  may also connect to the network  110  through the switch  106  and the circuit  102 . 
     In one example, the system  100  may use an iSCSI software initiator  102 . However, other protocol specific initiators may be implemented to meet the design criteria of a particular implementation. In an iSCSI environment, a /PROC virtual file system may be implemented to inject error during PDU generation. The “/” generally indicates a directory structure and the “PROC” generally indicates a directory name. The particular name may be varied to meet the design criteria of a particular implementation. In one example, such a virtual file system may be implemented in a Linux operation system. However, other operating systems may be implemented to meet the design criteria of a particular implementation. By modifying the values in the PROC file system, which the iSCSI initiator  102  uses while generating PDU, the system  100  may inject one or more errors into the PROC file system. The errors may be controlled in a manner useful for testing the way a particular network environment reacts to actual errors. The controlled errors may be used for testing prior to setting the network to a “live” state. The PDU transmission may be logged in the host circuit  104  which may be used for further analysis. 
     The complete testing using error injection may be automated using a shell/expect script. Automation of such scripts may contain details such as (i) Internet Protocol (IP) address of Initiator and Target, (ii) Port Number for communication [e.g., default 3260], (iii) Logon credentials (if needed), and/or (iv) values to be varied in PROC entry etc. 
     System specifications may include (i) Linux machine with 2.6 kernel as the initiator host  104 , (ii) development packages installed in the host  104 , (iii) a software initiator with error injection module, (iv) a NIC (Network Interface Card) port to connect to the initiator  102 , (v) support for shell/expect script, and/or (vi) if a firewall is present, communication through the specified port should be enabled. 
     Referring to  FIG. 2 , a more detailed diagram of the initiator target  100  is shown. The initiator  102  generally comprises a block (or circuit)  111  and a block (or circuit)  112 . The circuit  111  may be implemented as a testing section (or circuit). The circuit  111  generally comprises a block (or circuit)  114 , a block (or circuit)  116  and a block (or circuit)  118 . The circuit  112  may be implemented as a script circuit. The circuit  114  may be implemented as a PROC circuit. The circuit  116  may be implemented as a kernel circuit. The circuit  118  may be implemented as a user circuit. 
     The initiator  102  may have an input/output  120  and an input/output  122 . The inputs/outputs  120  and  122  may generate a signal ERROR_FLOW. The protocol specific errors generated by the initiator  102  may be included in the signal ERROR_FLOW. The signal ERROR_FLOW may be presented (or connected) from input/output  120  to the input/output  128 . The signal ERROR_FLOW may also be presented (or connected) from input/output  122  to the input/output  130 . The input/output  120  may be connected to the input/output  128  by a network cable  124 . The input/output  122  may be connected to the input/output  122  by the network cable  126 . In one example, the network cable  124  and the network cable  126  may be implemented as Fibre channel cables (or links). However, other types of links may be implemented to meet the design criteria of a particular implementation. 
     The host circuit  104  generally comprises an input/output  140  and an input/output  142 . The signal ERROR_FLOW may be presented (or connected) from the input/output  132  to the input/output  140 . The signal ERROR_FLOW may be presented (or connected) from the input/output  134  to the input/output  142 . The input/output  132  may be connected to the input/output  140  by a network cable  136 . The input/output  134  may be connected to the input/output  142  by the network cable  138 . In one example, the network cable  136  and the network cable  138  may be implemented as Fibre channel cables (or links). However, other types of links may be implemented to meet the design criteria of a particular implementation. 
     Referring to  FIG. 3 , a flow diagram  300  is shown. The flow diagram  300  generally comprises a step (or state)  302 , a step (or state)  304 , a step (or state)  306 , a step (or state)  308 , a step (or state)  310 , a step (or state)  312  and a step (or state)  314 . The step  302  provides a shell/expect script that would be created with the required value to change in the PROC entries. The state  304  determines that once the script is executed the PROC value will be changed. The step  306  determines that while generating PDU, the initiator  102  will look into the PROC entries to acquire the key equal to the value pairs of the PDU. The step  308  determines that the PROC entry contains the value which was set by the script, hence the PDU generated contains the erroneous value. The step  310  determines that the PDU will be sent to the target  104 . The step  312  determines that upon receiving the erroneous value from the initiator  102  the target  104  should respond properly for the erroneous value. The step  314  determines when to certify whether the target  104  responded properly for the erroneous value received from the initiator  102 . The iSCSI services are normally started in both the initiator  102  and target  104 . 
     The system  100  may inject errors in the PDU response without tapping the original communication. Various values PROC entries may be charged. For example, “Active Version Change, CHAP (Challenge Handshake Authentication Protocol) A, CHAP C Length, Delay PDU response, Drop PDU, Drop Connection, Inject Digest Error, under run, over run, CRC error, reset, etc.” The system  100  may be used to provide error injection even on a remote setup using the switch  106 . 
     The present invention may be extended to inject errors in software target  104  which enables testing of the initiator  102 . Such an implementation may simulate erroneous conditions at initiator  102 , by modifying the PDU values to obtain the expected result. The present invention may work with any device capable of sending iSCSI request PDUs and receiving iSCSI response PDUs. The present invention may be expanded to inject errors in a target for testing the initiator  102 . The present invention may be implemented with any iSCSI target devices (e.g., iSCSI Controllers, key iSCSI software targets, etc.) that need to be tested. Other protocols (e.g., other than iSCSI) may also be implemented. 
     The function performed by the software module of  FIG. 3  may be implemented using a conventional general purpose digital computer programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). 
     The present invention may also be implemented by the preparation of ASICs, FPGAs, or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s). 
     The present invention thus may also include a computer product which may be a storage medium including instructions which can be used to program a computer to perform a process in accordance with the present invention. The storage medium can include, but is not limited to, any type of disk including floppy disk, optical disk, CD-ROM, magneto-optical disks, ROMs, RAMS, EPROMs, EEPROMs, Flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions. 
     While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention.

Technology Category: 5