WO2016121078A1

WO2016121078A1 - Communication system and communication method

Info

Publication number: WO2016121078A1
Application number: PCT/JP2015/052612
Authority: WO
Inventors: 松本　典剛; 山田　勉
Original assignee: 株式会社日立製作所
Priority date: 2015-01-30
Filing date: 2015-01-30
Publication date: 2016-08-04

Abstract

The present invention addresses the problem of preventing, in performing data communication among a plurality of applications or OSs, a problem of some OSs or the like from spreading to other OSs or the like. As a solution, the present invention provides a communication system, wherein: when request data as a request to a server system is issued by an application executed on an OS of a client system, communication-only data corresponding to the content of the request data is generated, and the generated communication-only data is transmitted to the server system via a first communication path; and when receiving the communication-only data from the client system, the server system selects pseudo data corresponding to the communication-only data from among a plurality of pieces of pseudo data stored in advance, and performs processing for an application executed on an OS on the server side by using the selected pseudo data.

Description

Communication system and communication method

The present invention relates to a communication system and a communication method.

In recent years, in order to improve the performance of a processor, a method of improving processing performance by mounting a plurality of cores to suppress power consumption, rather than increasing the operating frequency, is becoming mainstream. In addition, a technique has been established in which a plurality of OSs (operating systems) are mounted on one processor and each OS is operated independently. As described above, with the advancement of processor and OS mounting techniques, various applications can be simultaneously mounted and executed in parallel on a single or a plurality of processors. For example, in an embedded device used in a control system or the like, a lightweight OS for real-time processing and an OS for network processing are simultaneously installed in a processor and executed in parallel without affecting real-time control. An environment that can use abundant network functions can be realized.

In this way, when a plurality of OSs are installed in a processor, communication between the OSs is generally performed using a shared memory. In addition, in order to facilitate data processing on the application side, communication between OSs uses server / client communication using the TCP / IP protocol. However, when the data communication path between OSs is not an IP network, such as communication between processors or between cores, the TCP / IP protocol cannot be used as it is.

Therefore, for example, as shown in Patent Document 1, a method for realizing server-client communication using the TCP / IP protocol on the application side by tunneling using a virtual network interface is shown on the application side.

JP 2011-239343 A

When performing data communication between a plurality of OSs using information system technology such as TCP / IP, it is necessary to prevent some OS failures from affecting other OS processes. For example, when an OS or application connected to a network becomes unable to operate normally due to a cyber attack or virus infection, it is necessary to prevent damage from spreading to other OSs and applications. In the above-described known technology, there is no particular description about security measures when a virtual network interface is used.

Therefore, the present invention provides a communication system or a communication method that can prevent problems of some OSs from spreading to other OSs when data communication is performed between a plurality of applications or OSs. Objective.

In order to solve the above-described problem, one of the representative communication apparatuses and methods of the present invention is configured such that when request data that is a request to the server system is issued by an application executed on the OS of the client system, The communication dedicated data corresponding to the content of the request data is generated, and the generated communication dedicated data is transmitted to the server system via the first communication path, and the server system receives the communication dedicated data from the client system. Upon receipt, the pseudo data corresponding to the communication-dedicated data is selected from a plurality of pseudo data stored in advance, and the processing of the application executed on the server side OS is performed using the selected pseudo data It is.

According to the present invention, when data communication is performed between a plurality of applications or OSs, it is possible to prevent problems of some OSs from spreading to other OSs.

It is the figure which showed an example of the structure of the data processor in 1st Embodiment. It is the figure which showed an example of the structure of the data processor in 1st Embodiment. It is the figure which showed an example of the structure of the data processor in 1st Embodiment. It is the figure which showed an example of the processing sequence of the data processor in 1st Embodiment. It is the figure which showed an example of the processing flow of the protocol determination part and detoxification part in 1st Embodiment. It is the figure which showed an example of the detoxification process of the detoxification part in 1st Embodiment. It is the figure which showed an example of the processing flow of the pseudo data setting / selection part in 1st Embodiment. It is the figure which showed an example of the structure of the data processor in 2nd Embodiment. It is the figure which showed an example of the processing flow of the sequence management part in 2nd Embodiment. It is the figure which showed an example of the processing flow of the sequence management part in 2nd Embodiment. It is the figure which showed an example of the processing sequence of the data processor in 2nd Embodiment. It is the figure which showed an example of the processing sequence of the data processor in 2nd Embodiment. It is the figure which showed an example of the processing sequence of the data processor in 2nd Embodiment. It is the figure which showed an example of the structure of the data processor in 3rd Embodiment. It is the figure which showed an example of the processing sequence of the data processor in 3rd Embodiment.

Next, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as appropriate.

(First embodiment)
The present embodiment particularly relates to a data processing apparatus in which a plurality of arithmetic devices perform data processing using a storage device, and a secure communication method via a storage device between the plurality of arithmetic devices. As shown in FIG. 1, the data processing apparatus 1 in the first embodiment includes a calculation unit 2, a storage unit 3, a virtual network interface 4 (hereinafter abbreviated as a virtual network IF 4), a one-way communication path 5, and a dedicated path 6. An OS 7, a protocol stack 8, an application 9, and a setting input unit 10 are configured.

The calculation unit 2 has a function of performing reading and writing of data with the storage unit 3 and performing calculation processing in accordance with instructions stored in the storage unit 3. For example, an integrated circuit such as a processor, a core of the processor, or an LSI (Large Scale Integration). As shown in FIG. 1, a plurality of calculation units 2 may be installed for each function or OS 7, or a plurality of functions or OS 7 may be processed by only one calculation device as shown in FIG.

The storage unit 33 has a function of holding data such as programs. For example, a processor built-in register, a volatile memory, a nonvolatile memory, a hard disk, and the like. The protocol stack 8 is software for executing communication using a predetermined communication protocol such as the TCP / IP protocol stack 8. The OS 7 and the protocol stack 8 may be mounted separately as shown in FIG. 1, or the functions of the OS 7 and the protocol stack 8 may be integrated as shown in FIG. Further, software corresponding to an application may directly perform data communication using the virtual network IF 4 without installing the OS 7 or the protocol stack 8.

The application 9 is software for performing data communication with another OS 7, and is, for example, a server application 9 (hereinafter abbreviated as a server application 9) or a client application 9 (hereinafter abbreviated as a client application 9). In this example, the server application 9 is installed on the computing unit 2A side and the client application 9 is installed on the computing unit 2B side. However, both the server application 9 and the client application 9 functions are installed on one side. May be.

The virtual net IF 4 includes a pseudo data setting / selection unit 11, a pseudo data list 12, a protocol determination unit 13, and a detoxification unit 14. The virtual network IF 4 is an interface for performing data communication between the server application 9 and the client application 9 via the one-way communication path 5 and the dedicated path 6, and has a data format that can be processed by the general-purpose OS 7 and the protocol stack 8. It has a function to enable virtual communication.

Here, when the OS 7 processed by the calculation unit 2 is equipped with both the server application 9 and the client application 9, the virtual IF 4 needs the above-described configuration, but when only the server application 9 is installed, The virtual net IF 4 only needs to have only the pseudo data setting / selection unit 11 and the pseudo data list 12. Similarly, when only the client application 9 is installed, the virtual network IF 4 may have only the protocol determination unit 13 and the harmless unit 14.

Further, in the following detailed description of the present embodiment, the data processing apparatus having the configuration shown in FIG. 1 is taken as an example, but the maximum number of computing units 2, virtual net IFs 4, OS7, etc. is not limited to two. . For example, as shown in FIG. 3, a plurality of arithmetic units 2 may be connected to virtual nets IF 4 of other plural arithmetic units 2 via a one-way communication path 5 and a dedicated path 6, respectively. In this case, the virtual network IF may have only a function for the server application 9, may have only a function for the client application 9, or may have both functions.

The protocol determination unit 13 has a function of determining a protocol type and a data format of data received from the client application 9 or the server application 9 and determining how to process the data. The detoxification unit 14 has a function of detoxifying (sanitizing) the transmission data from the client application 9 and transmitting it as the detoxification data 16 via the dedicated path 6. Details of the detoxification will be described later.

The pseudo data setting / selection unit 11 has a function of receiving the detoxified data 16, selecting the pseudo data 17 corresponding to the detoxified data 16 from the pseudo data list 12, and transmitting it to the server application 9 side. Further, according to an instruction from the setting input unit 10, it has a function of setting an association between the detoxification data 16 and the pseudo data 17 to be selected. Further, it may have a function of adding, deleting, changing, etc., the pseudo data 17 registered in the pseudo data list 12.

The pseudo data list 12 is a set of data having the same type of data format as the request data 15 transmitted from the client application 9 to the server application 9, for example. The setting input unit 10 is an interface for setting the association between the detoxification data 16 and the pseudo data 17, and is, for example, an application interface (API) or a human machine interface (HMI). Note that the setting input unit 10 may not be mounted if the processing method of the pseudo data setting / selection unit 11 and the contents of the pseudo data list 12 are not changed.

The one-way communication path 5 is a communication path for directly sending actual data such as response data 18 transmitted from the server application 9 to the client application 9 side. For example, it may be a network such as Ethernet, or may be an internal bus such as a memory bus, or a peripheral interface such as PCI or PCI-Express. The dedicated path 6 is a means for transmitting the harmless data 16 from the client application 9 side to the server application 9 side. The dedicated path 6 may be a network, an internal bus, or a peripheral interface as with the one-way communication path 5, or may be a simple signal line, a serial communication path, or a parallel communication path. For example, an I / O signal or an interrupt signal. However, the dedicated path 6 and the one-way communication path 5 do not share data.

An example of a processing sequence in the data processing apparatus 1 when the client application 9 transmits request data 15 to the server application 9 and the server application 9 returns response data 18 to the client will be described with reference to FIG. .

First, the client application 9 transmits request data 15 to the server application 9 (processing S401). The request data 15 is, for example, a SYN packet for requesting connection establishment in TCP communication, an HTTP request used in Web server / client communication, or the like. Next, the protocol determination unit 13 determines the data type or the like of the request data 15 and determines how to process it (processing S402). For example, when the request data 15 is transmitted from the client application 9 to the server application 9, the request data is transferred to the detoxification unit 14 and the process is entrusted (process S403).

Next, the detoxification unit 14 detoxifies the request data 15 and converts it into the detoxification data 16 (process S404). The detailed processing flow of the protocol determination unit 13 and the detoxification unit 14 will be described later. The detoxification data 16 is transmitted to the server application 9 side via the dedicated path 6 (processing S405). Next, the pseudo data setting / selection unit 11 on the server application 9 side receives the harmless data 16 and selects the pseudo data 17 corresponding to the harmless data 16 from the pseudo data list 12 (processing S406). The pseudo data list 12 transmits the selected pseudo data 17 to the server application 9 side directly or via the pseudo data setting / selection unit 11 (process S407).

In the server application 9, for example, response data 18 is generated according to the received pseudo data 17 as a server process (process S408), and is transmitted to the client application 9 via the one-way communication path 5 (process S409). The response data 18 is, for example, a SYN / ACK packet used for establishing a connection in TCP communication, an HTTP response used in Web server / client communication, or the like.

Finally, the protocol determination unit 13 receives the response data 18 from the server, and performs the determination process in the same manner as the process S402 (process S410). If response data is received from the server application 9 side to the client application 9 side, the received data is transmitted to the client application side (step S411). Here, the processing S410 is omitted, and the response data 18 from the server application 9 side may be directly transmitted to the client application 9 side.

The detailed processing flow of the protocol determination unit 13 and the detoxification unit 14 will be described with reference to FIG. First, the protocol determination unit 13 determines whether or not the received data has a valid data format (processing S501). For example, the header or footer information of the data packet is analyzed to determine whether or not the protocol type can be processed. A CRC check or the like may be executed to determine the presence or absence of data errors.

Next, when it is determined that the received data is normal, it is determined whether the address information of the data transmission source or the transmission destination is valid (processing S502). For example, when the transmission source is the address of the client application 9 side and the transmission destination is the address of the server application 9 side, the request data 15 is determined and the data is transmitted to the harmless unit 14. Here, in addition to the address information, there is a method of determining based on information such as a port number in the case of TCP protocol or UDP protocol. Moreover, when it is not the data transmitted to the detoxification part, you may determine whether it is the response data 18 from the server application 9 side (process S505). For example, if the data transmission source address is the address on the server application 9 side and the transmission destination is its own address, it is determined that the data is the response data 18 and the data may be transmitted to the client application 9 side (processing S506). ).

Next, when data is transmitted to the detoxification unit 14, it is determined whether or not the data is to be detoxified (processing S503). If the data is to be detoxified, the detoxification process is executed, and the detoxification data 16 is transmitted to the server application 9 side via the dedicated path 6 (process S504). If negative determinations are made in steps S501, S503, and S505, error processing such as abnormality / warning notification to the application 9 may be executed and the processing may be terminated (step S507).

An example of the detoxification process in the detoxification unit 14 will be described with reference to FIG. The detoxification unit assigns an identification number or the like corresponding to the format of the request data 15 transmitted by the client application 9 as the detoxification data 16. For example, the detoxification data 16 corresponding to the ACK packet in TCP communication is set to “0”. Similarly, identification numbers such as “1” and “2” are assigned to SYN packets and SYN / ACK packets, respectively. In addition, an identification number “3” is assigned when the data format is a specific pattern A (data A), and an identification number “4” is assigned when the data format is data B or data C. If the data format is not specified, it may be discarded as invalid data and notified to the client application 9 as an error. Here, the association between the request data 15 and the detoxification data 16 may be a method other than this example, or the setting input unit 10 may be provided to set the association from the outside.

For example, all or part of the header or footer information of the request data 15 may be left, and data combined with the above-described identification number may be made harmless data. Further, a hash value calculated using a known compression technique or encryption technique may be used as the harmless data 16.

An example of the processing flow of the pseudo data setting / selection unit 11 will be described with reference to FIG. First, it is determined whether or not the detoxification data 16 has been received from the dedicated path 6 (processing S701). When the detoxification data 16 is received, it is determined whether or not the detoxification data 16 is set in advance by the setting input unit 10 (step S702). If the invalid sanitization data 16 is not set, error processing such as abnormality / warning notification to the application 9 side may be executed and the processing may be terminated (processing S707). If the detoxified data 16 has been set, the corresponding pseudo data 17 is selected from the pseudo data list 12 (step S703).

Next, it is determined whether or not the content of the selected pseudo data 17 needs to be changed (processing S704). If it is not necessary to change the data, the pseudo data 17 is transmitted as it is to the server application 9 side (step S706). If the data needs to be changed, a part of the data is changed in the pseudo data setting / selection unit 11 and then transmitted to the server application 9 (processing S7056 and processing S706). As a selection method of the pseudo data 17 in the processing process S703, for example, there is a method of executing a process reverse to the conversion process from the request data 15 to the detoxification data 16 shown in FIG. For example, when the identification number “0” is received as the detoxification data 16, an ACK packet may be selected as the pseudo data 17. Similarly, when the identification numbers “1”, “2”, and “3” are received as the detoxification data 16, the SYN packet, the SYN / ACK packet, and the data A are selected as the pseudo data 17, respectively. When the identification number “4” is received, both data B and data C are selected as the pseudo data 17.

The change of the pseudo data in the process S705 is, for example, changing the data header or footer information from a preset value. For example, when the harmless data 16 includes header information, there is a method of reflecting the difference in the header information on the pseudo data 17 side. Further, when the detoxification data 16 is composed of only a simple identification number, variable information such as a sequence number is individually managed on the server application 9 side and the client application 9 side so that they can be consistent with each other. There are methods such as setting values. A detailed example will be described in the second embodiment.

Further, the processing method in processing S702, processing S703, processing S704, and processing S705 and the contents of the pseudo data list 12 may be set or changed by the setting input unit 10.

As described above, according to the present embodiment, the data request from the client application 9 side is not transmitted directly to the server application 9 side, but is harmless, so that harmful data is transferred from the client application 9 side to the server application 9 side. Can be prevented from being sent to. On the other hand, by using the pseudo data 17 on the application side, it is possible to use a communication protocol corresponding to bidirectional communication while restricting actual data communication in one direction.
(Second Embodiment)
A data processing device 21 in the second embodiment will be described with reference to FIG. As in the first embodiment, the calculation unit 2, the storage unit 3, the virtual net IF 22, the one-way communication path 5, the dedicated path 6, the OS 7, the protocol stack 8, the application 9, and the setting input unit 10 are configured. Note that the functions of the calculation unit 2, the storage unit 3, the one-way communication path 5, the dedicated path 6, the OS 7, the protocol stack 8, the application 9, and the setting input unit 10 are the same as those in the first embodiment, and therefore will not be described or illustrated. Omitted.

The virtual network IF 22 includes a pseudo data setting / selection unit 23, a pseudo data list 24, a protocol determination unit 25, a detoxification unit 26, a sequence management unit 27, and a flow control unit 28. The virtual network IF 22 has functions of performing sequence management and flow control in data transmission / reception between the server application 9 and the client application 9 in addition to the same functions as in the first embodiment. The sequence management unit 27 has a function of managing sequence information of data transmitted and received between the applications 9. The flow control unit 28 has a function of performing flow control of data transmitted and received between the applications 9.

FIG. 8 shows a processing flow of the sequence management unit 27 on the client application 9 side. First, it is determined whether or not sequence management of data received by the protocol determination unit 25 is necessary (processing S901). For example, the protocol determination unit 25 identifies the protocol type from data header information and the like, and determines whether the protocol requires sequence management, such as the TCP protocol. If the sequence management is unnecessary, the process is terminated. If necessary, it is determined whether the sequence information of the received data is valid (process S902). For example, it is determined whether or not a sequence number that has been recorded in the past is consistent, and if a mismatch has occurred, an error process or the like is executed (processing S906).

Next, when the sequence information is valid, it is determined whether the data transmission direction is from the client application 9 to the server application 9 or from the server application 9 to the client application 9 (step S903). In the case of data transmission from the client application 9 side to the server application 9 side, that is, when it is necessary to execute the detoxification process in the detoxification unit 26, the sequence information of the data is stored (process S904). Conversely, in the case of data transmission from the server application 9 side to the client application 9 side, the sequence information of the data to be transmitted to the client application 9 side is restored based on the stored sequence information.

FIG. 10 shows a processing flow of the sequence management unit 27 on the server application 9 side. First, it is determined whether or not the sequence management of the data selected by the pseudo data setting / selection unit 23 is necessary (processing S1001). For example, there is a method of identifying the protocol type from the header information of the data as in the above-described processing S901. If it is determined that sequence management is necessary, it is determined whether the target data is a connection newly created between the server application 9 and the client application 9 (step S1002). For example, there is a method of determining whether or not it is the first data transmission / reception in a series of data transmission / reception generated by communication between a specific server and client, and holding the flag information as to whether or not the communication is the first communication. . In the case of a new connection, pseudo sequence information to be given to the pseudo data 17 is issued and stored together with the above flag information (processing S1003). If it is not a new connection, the stored pseudo sequence information is updated and reflected in the sequence information of the pseudo data 17 (step S1004).

Here, in FIG. 9 and FIG. 10, the sequence management unit 27 on the server application 9 side and the client application 9 side has been described as operating in different processing flows, but the functions of both the server application 9 and the client application In the case of having both, the processing flow can be executed also for the sequence management unit.

An example of a processing sequence of the data processing apparatus in the present embodiment will be described with reference to FIG. This sequence is an example in the case of performing the same processing as the three-way handshake when establishing a connection in TCP communication. First, the client application 9 sends a SYN packet for establishing a TCP connection with the server application 9 (step S1101). Here, it is assumed that the X number is assigned to the SYN packet as a sequence (SEQ) number by processing on the client application side. Next, the protocol determination unit 25 receives the SYN packet as the request data 15, and the sequence management unit 27 stores the sequence number X of the SYN packet (processing S1102).

Next, the detoxifying unit 26 detoxifies the SYN packet according to the same processing flow as in the first embodiment (processing S1103). Here, it is assumed that the identification number “1” is transmitted as the harmless data 16 to the pseudo data setting / selecting unit 23 on the server application 9 side via the dedicated path 6 (processing S1104). The pseudo data setting / selection unit 23 selects a SYN packet from the pseudo data list 24 as the pseudo data 17 corresponding to the detoxified data 16 according to the same processing flow as in the first embodiment (processing S1105). Here, in the case of normal server / client communication, it is necessary to transmit the data to which the sequence number X given by the client application 9 is given to the server application 9 side, but the sequence number is not transmitted by detoxification. . Accordingly, the sequence management unit 27 on the server application 9 side generates a pseudo sequence number Y and assigns it to the pseudo data as a new sequence number (processing S1106).

Therefore, the SYN packet with the sequence number Y is sent to the server application 9 side (processing S1107). The server application 9 executes a server process corresponding to the reception of the SYN packet (process S1108). Here, a SYN / ACK packet in which Z is newly added as the sequence number and Y + 1 is set in the ACK number is sent to the client application 9 side (processing S1109).

When the protocol determination unit 25 on the client application 9 side receives the SYN / ACK packet sent from the server application 9 side, the sequence management unit 27 transmits it to the client application side based on the sequence number stored in step S1102 The sequence information of the data to be restored is restored (processing S9). That is, the ACK number of the SYN / ACK packet is changed to X + 1. Therefore, the SYN / ACK packet having the sequence number Z and the ACK number X + 1 is sent to the client application 9 side (processing S1111).

Next, since the client application 9 can determine that the SYN / ACK packet corresponding to the SYN packet transmitted in the process S1101 has been normally received, the client application 9 transmits an ACK packet (process S1112). That is, an ACK packet in which X + 1 is set as the sequence number and Z + 1 is set as the ACK number is transmitted (processing S1113). Similar to the processing S1102, the protocol determination unit 25 receives the ACK packet as the request data 15, and the sequence management unit 27 stores the sequence number X + 1 of the ACK packet (processing S1114). Next, the ACK packet is rendered harmless in the same manner as in the processing 1103 (processing S1115), and the identification number “0” is transmitted as the harmless data 16 to the server application 9 side via the dedicated path 6 (processing S1116).

The pseudo data setting / selection unit 23 selects an ACK packet from the pseudo data list 24 as the pseudo data 17 corresponding to the detoxified data 16 as in the process 1105 (process S1117). Here, in normal server / client communication, it is necessary to send the sequence number X + 1 and the ACK number Z + 1 assigned by the client application 9 to the server application 9, but the sequence information is transmitted by detoxification. It has not been. Therefore, based on the pseudo sequence generated in process S1106, the sequence management unit 27 assigns Y + 1 as the pseudo sequence number (process S1118). At the same time, in process S1108 and process S1109, Z + 1 is assigned as the ACK number based on the sequence number Z assigned by the server application 9 side.

Therefore, an ACK packet in which the sequence number Y + 1 and the ACK number Z + 1 are set is sent to the server application 9 side (processing S1119). Finally, the server application 9 side executes server processing corresponding to reception of the SYN packet (processing S1120). That is, since the server application 9 side can determine that a normal ACK packet has been received as a reply to the SYN / ACK packet transmitted to the client application 9 side, a 3-way handshake in the TCP protocol is established, and the connection between the server and the client is established. It will be established.

A sequence for transmitting and receiving data packets using the TCP connection established using FIG. 12 will be described. An example in which a data packet is transmitted from the server application 9 side to the client application 9 side is shown. First, the server application 9 transmits a data packet in which Z + α is set as a sequence number and Y + β is set as an ACK number to the client application 9 side (processing S1201). Next, when the protocol determination unit 25 on the client application 9 side receives the data packet sent from the server application 9 side, the sequence management unit 27 uses the sequence number stored in the above-described processing S1114 to The ACK number of the packet is changed to X + β (processing S1202). Therefore, the data packet with the sequence number Z + α and the ACK number X + β is sent to the client application 9 side (processing S1203). On the client application 9 side, an ACK packet corresponding to the received data packet is issued (processing S1204). That is, an ACK packet set to sequence number X + β and ACK number Z + α ′ is transmitted (processing S1205). The protocol determination unit 25 receives the ACK packet as transmission data from the client application 9 side, and the sequence management unit 27 stores the sequence number X + β of the ACK packet (processing S1206). The detoxification section 26 detoxifies the ACK packet in the same manner as described above (process S1207), and then transmits the identification number “0” as the detoxification data 16 to the server application 9 side via the dedicated path 6 ( Process S1208).

The pseudo data setting / selection unit 23 on the server application 9 side selects an ACK packet from the pseudo data list 24 as the pseudo data 17 corresponding to the harmless data 16 (processing S1209). Here, in the case of normal server / client communication, it is necessary to set the sequence number X + β and the ACK number Z + α ′ assigned by the client application 9 side to the data to the server application 9 side. The sequence number is not communicated. Therefore, similarly to the above-described processing S1118, the sequence management unit 27 on the server application 9 side assigns the pseudo sequence number Y + β and the ACK number Z + α ′ (processing S1210). Therefore, an ACK packet in which sequence number Y + β and ACK number Z + α ′ are set is sent to the server application 9 (step S1211). The server application 9 side executes server processing corresponding to reception of the ACK packet (processing S1212). For example, the sequence number Z + α ′ and the ACK number Y + β ′ are set as the next data packet and sent to the client application 9 side (step S1213). Thereafter, similarly, the sequence management unit on the client application 9 side returns the sequence information of the data to be transmitted to the client application 9 side from the stored sequence information (processing S1214). Finally, the data packet set with the sequence number Z + α ′ and the ACK number X + β ′ is sent to the client application 9 side (processing S1215).

Here, in the process S1212 on the server application 9 side, for example, there is a method of executing a data packet retransmission process when an ACK packet from the client side cannot be received within a predetermined time, that is, when a timeout occurs. Further, when inconsistency is detected in the sequence number or ACK number, retransmission processing or error processing may be executed.

An example of a processing sequence using the flow control unit 28 will be described with reference to FIG. Here, a processing example in the case where a plurality of data packets such as UDP are continuously transmitted from the server application 9 side is shown. First, when data transmission from the server application 9 occurs (processing S1301), the flow control unit 28 temporarily stores the received data in an internal buffer or the like, via the one-way communication path 5, The data are sequentially transmitted to the client application 9 side (processing S1302). Here, the data storage in the buffer or the like may be executed on the flow control unit 28 side on the server application 9 side or may be executed on the flow control unit 28 side on the client application 9 side.

Next, the flow control unit 28 on the client application 9 side sequentially transmits the data packets received by the protocol determination unit 25 to the client application 9 side (processing S1303). At the same time, the flow control unit 28 generates a pseudo ACK packet to notify the server application 9 that the data packet has been normally received, and transmits the ACK packet to the harmless unit 26 (processing S1304). The detoxification unit 26 detoxifies the ACK packet and transmits, for example, the identification number “0” as the detoxification data 16 to the server application 9 side via the dedicated path 6 (processing S1305). Here, the flow control unit 28 directly instructs the detoxification unit 26 to transmit a predetermined identification number “0”, instead of generating a pseudo ACK packet and transmitting it to the detoxification unit 26. May be.

When the pseudo data setting / selection unit 23 on the server application 9 side receives the identification number “0” corresponding to ACK as the harmless data 16, the flow control unit 28 normally transmits the first data packet. It determines with having been completed (process S1306), and a data packet is continued to the client application 9 side (process S1307). Here, for example, when the harmless data 16 with the identification number “0” corresponding to the ACK from the client side cannot be received within a predetermined time, that is, when a timeout occurs, the data packet retransmission process may be executed. Alternatively, transmission of the data packet may be interrupted and notified to the server application side.

In the data processing device 21 in the second embodiment, the processes of the sequence management unit 27 and the flow control unit 28 described above may be performed separately or in parallel.

As described above, according to the present embodiment, the data request from the client application 9 side is not transmitted directly to the server application 9 side, but is harmless, so that harmful data is transferred from the client application 9 side to the server application 9 side. Can be prevented from being sent to. Furthermore, in data communication between applications, it is possible to execute sequence management and flow control, which are difficult without bidirectional communication, while restricting actual data communication in one direction.

(Third embodiment)
A data processing apparatus according to the third embodiment will be described with reference to FIG. As in the first embodiment or the second embodiment, the calculation unit 2, the storage unit 3, the virtual network IF 32, the one-way communication path 5, the dedicated path 6, the OS 7, the protocol stack 8, the application 9, and the setting input unit 10 Composed. The functions of the calculation unit 2, the storage unit 3, the one-way communication path 5, the dedicated path 6, the OS 7, the protocol stack 8, the application 9, and the setting input unit 10 are the same as those in the first embodiment or the second embodiment. Therefore, explanation or illustration is omitted.

The virtual network IF 32 includes a pseudo data setting / selection unit 33, a pseudo data list 34, a protocol determination unit 35, a detoxification unit 36, and a priority control unit 37. The virtual network IF 32 has a function of performing priority control of data transmitted and received between the server application 9 and the client application 9 in addition to the same functions as in the first embodiment. The priority control unit 37 has a function of performing priority control of data transmitted and received between the applications 9.

An example of a data processing sequence in this embodiment will be described with reference to FIG. First, when data is transmitted from the client application 9 (process S1501), the priority control unit 37 sets the priority of the data (process S1502). The priority setting may be specified on the application 9 side, or the protocol determination unit 35 may identify the protocol type of the data and automatically assign a predetermined priority. Next, the detoxification unit 36 transmits the detoxification data 16 to the server application 9 side by a method according to the priority setting (processing S1503). Here, it is assumed that the detoxification data 16 having a low priority is transmitted. As a method for setting the priority, for example, there is a method in which a plurality of dedicated paths 6 are prepared for each priority and transmitted to the dedicated path 6 according to the priority. Further, a method of giving priority information to the detoxification data 16 and transmitting it may be used.

The pseudo data setting / selection unit 33 on the server application 9 side selects the pseudo data 17 corresponding to the detoxified data when the detoxified data 16 is received (processing S1504). Here, the priority control unit 37 executes the priority process according to the priority of the received harmless data (process S1505). That is, it transmits to a server application side in an order with a high priority. For example, when the harmless data 16 with higher priority is received (process S1506), the pseudo data 17 with higher priority is sent to the server application 9 side first (process S1507). The server application 9 side executes server processing according to the acquired pseudo data 17 (step S1508), and transmits data to the client application 9 side (step S1509). When receiving data from the server application 9 side, the protocol determination unit 35 on the client application 9 side similarly performs priority control, and transmits the data from the higher priority data to the client application 9 side in order (processing S1510). . Here, in the priority control in step S1505, when the low-priority data transmission processing (processing S1511 and S1512) is processed before the high-priority data transmission processing (processing S1507 and S1509). In the priority control process in the process 1510, data with high priority may be transmitted to the client application 9 side first.

Note that the data processing of the priority control unit 37 in the present embodiment may be performed in parallel with the data processing of the sequence management unit 27 and the data processing of the flow control unit 28 in the second embodiment.

As described above, according to the present embodiment, the data request from the client application 9 side is not transmitted directly to the server application 9 side, but is harmless, so that harmful data is transferred from the client application 9 side to the server application 9 side. Can be prevented from being sent to. Further, by performing data priority control, highly real-time data communication processing can be executed securely.

As described in the first to third embodiments, when data is shared among a plurality of applications or OSs, a problem occurs in some data processing by limiting the data communication direction to one direction. However, it is possible to prevent other data processing from being affected.

Also, on the application side, a general-purpose bidirectional communication method such as TCP / IP can be used securely. Furthermore, even if a general-purpose processor or an old processor that does not have a security function mounted by default is used, a strong security function can be realized.

In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment. Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

1, 21, 31 Data processor 2 Arithmetic unit 2
3 Storage unit 3
4, 22, 32 Virtual network interface 5 One-way communication path 6 Dedicated path
7 OS
8 Protocol stack 9 Application 10

Setting input unit

11, 23, 33 Pseudo data setting /

selection unit

12, 24, 34

Pseudo data list

13, 24, 35

Protocol judgment unit

14, 26, 36 Detoxification unit 15 Request data 16 Detoxification Data 17 Pseudo data 18 Response data 27 Sequence management unit 28 Flow control unit 37 Priority control unit

Claims

A server system on which the server-side OS is executed;
A client system on which the client-side OS is executed;
A first communication path used for communication from the client system to the server system,
When request data, which is a request to the server system, is issued by an application executed on the client-side OS, the client system generates communication-specific data corresponding to the content of the request data, and generates the request data Transmitting the communication-dedicated data to the server system via the first communication path;
When the server system receives the communication-dedicated data from the client system, the server system selects from among a plurality of pseudo-data that pre-stores pseudo data corresponding to the communication-dedicated data, and uses the selected pseudo data to select the server Communication system that performs processing of applications executed on the OS on the side.
In claim 1,
A second communication path capable of communicating only in one direction from the server system to the client system;
Communication from the client system to the server system is performed via the first communication path by the communication dedicated data simplified in a predetermined format,
Communication from the server system to the client system is performed via the second communication path.
In claim 1,
The client system selects the code corresponding to the type of the request data to generate the communication dedicated data,
The server system selects corresponding pseudo data from the code in the received communication-dedicated data, and the selected pseudo data corresponds to the request data that is the basis of the received communication data. A communication system characterized by content.
In claim 2,
When the server system processes communication data to the client system, and when the client system processes data dedicated to communication to the server system, the server system and the client system sequence with each other. A communication system characterized by managing information.
In claim 4,
When the server system receives the communication-dedicated data from the client system, the server system sets pseudo-sequence information in the communication-dedicated data, and adds sequence information corresponding to the pseudo-sequence information to communication data to be sent to the client system. Send
The said client system updates the sequence information provided to the said communication using the sequence information provided to the received said communication data, The communication system characterized by the above-mentioned.
In claim 4,
A communication system, wherein at least one of the plurality of types of communication-dedicated data generated by the client system indicates that the communication data transmitted by the server system has been normally received by the client system.
In claim 6,
The server system, after transmitting the communication data to the client system, executes a time-out process when not receiving communication-dedicated data indicating that the data has been normally received within a predetermined time. A featured communication system.
In claim 1,
A priority is set for the communication-only data sent from the client system to the server system,
When the server system receives a plurality of the communication dedicated data, the server system changes the data processing order according to the priority of the received communication dedicated data.
When request data, which is a request to the server system, is issued by an application executed on the OS of the client system, communication dedicated data corresponding to the content of the request data is generated, and the generated communication dedicated data is the first To the server system via the communication path of
When the server system receives the communication-dedicated data from the client system, the server system selects from among a plurality of pseudo-data that pre-stores pseudo data corresponding to the communication-dedicated data, and uses the selected pseudo data to select the server Communication method for processing an application executed on the OS on the side.
In claim 9,
Communication from the client system to the server system is performed via the first communication path by the communication dedicated data simplified in a predetermined format,
The communication from the server system to the client system is performed via a second communication path capable of communication in only one direction from the server system to the client system.
In claim 10,
The client system generates the communication dedicated data including a code corresponding to the type of the request data,
The server system selects corresponding pseudo data using the code in the received communication dedicated data, and the selected pseudo data is added to the request data that is the source of the received communication data. A communication method characterized by corresponding contents.