JPWO2009075007A1 - Communication control device and communication control method - Google Patents

Abstract

The communication control apparatus 10 includes a first database 50 that stores reference data serving as a reference for determining a method for controlling communication data for a plurality of types of communication data, and a reference data search target regardless of a plurality of types. A position detection circuit 32 that extracts data of a predetermined length as a comparison target data from a predetermined position of the acquired communication data, and a comparison target that is extracted according to the type of the acquired communication data Of the data, a mask circuit 380 that masks data other than the search target data, a search circuit 30 that searches the first database 50 for reference data included in the masked comparison target data, and a search result of the search circuit 30 And a processing execution circuit 40 for controlling communication data.

Description

  The present invention relates to a communication control technique, and more particularly to a communication control apparatus and a communication control method for controlling communication data.

  With the development of the Internet infrastructure and the widespread use of communication terminals such as mobile phone terminals, personal computers, and VoIP (Voice over Internet Protocol) telephone terminals, the number of Internet users is increasing explosively. Under such circumstances, security problems such as computer viruses, hacking, and spam mails are becoming obvious, and a technique for appropriately controlling communication is required.

Although it has become possible to easily access a vast amount of information using the Internet, it is also true that harmful information is flooding, and regulations on the source of harmful information cannot be caught up. is there. In order to create an environment in which everyone can use the Internet safely and effectively, technology that appropriately controls access to harmful content is required.
International Publication WO2006-087832 Pamphlet

  In recent years, due to the exhaustion of IP addresses in IPv4, the transition to IPv6 in which a larger address space is prepared is progressing, but both packets of IPv4 and IPv6 are communicated during the transitional period. Thus, there is a need for a technique for appropriately controlling a plurality of types of communication data.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for appropriately controlling a plurality of types of communication data.

  One embodiment of the present invention relates to a communication control apparatus. The communication control device is a database that stores reference data serving as a reference for determining a method for controlling communication data for a plurality of types of communication data, and is a search target for the reference data regardless of the plurality of types. An extraction unit that extracts data of a predetermined length from the predetermined position of the acquired communication data as comparison target data so that the search target data is included, and the extracted comparison target data according to the type of the acquired communication data Among them, a mask circuit that masks data other than the search target data, a search circuit that searches reference data included in the masked comparison target data from the database, and the communication according to a search result of the search circuit And a processing execution circuit for controlling data.

  The reference data stored in the database has the same data length as the comparison target data, and the position of the search target data in the comparison target data according to the type of communication data to be compared with the reference data Data at positions other than may be masked. The mask circuit stores the same data as the data stored at the masked position among the reference data stored in the database at a position other than the search target data in the comparison target data. May be.

  The mask circuit may store data functioning as a wild card at a position other than the search target data in the comparison target data.

  Another aspect of the present invention relates to a communication control method. In this communication control method, for a plurality of types of communication data, data of a predetermined length is compared with data to be compared from a predetermined position of the acquired communication data so that reference data serving as a reference for determining a method for controlling the communication data is included. And extracting and comparing the data other than the search target data to be searched by the search circuit among the extracted comparison target data according to the type of the acquired communication data and supplying the data to the search circuit And a step of searching for reference data included in the comparison target data from a database storing the reference data by the search circuit, and a step of controlling the communication data according to a search result. Features.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to provide a technique for appropriately controlling a plurality of types of communication data.

It is a figure which shows the structure of the communication control system which concerns on a premise technique. It is a figure which shows the structure of the conventional communication control apparatus. It is a figure which shows the structure of the communication control apparatus which concerns on a premise technique. It is a figure which shows the internal structure of a packet processing circuit. It is a figure which shows the internal structure of a position detection circuit. It is a figure which shows the example of the internal data of a 1st database. It is a figure which shows another example of the internal data of a 1st database. It is a figure which shows another example of the internal data of a 1st database. It is a figure which shows the structure of the comparison circuit contained in a binary search circuit. It is a figure which shows the example of the internal data of a 2nd database. It is a figure which shows another example of the internal data of a 2nd database. It is a figure which shows another structural example of the communication control apparatus which concerns on a premise technique. It is a figure which shows the internal structure of the packet processing circuit for URL filtering. FIG. 14A is a diagram showing an example of internal data of a virus / phishing site list, FIG. 14B is a diagram showing an example of internal data of a white list, and FIG. It is a figure which shows the example of the internal data of a black list. It is a figure which shows the example of the internal data of a common category list | wrist. FIGS. 16A, 16B, 16C, and 16D are diagrams showing examples of internal data of the second database. It is a figure which shows the priority of a virus / phishing site list, a white list, a black list, and a common category list. It is a figure which shows the structure of the packet processing circuit of the communication control apparatus which concerns on embodiment. It is a figure which shows the example of the internal data of a user database.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Communication control apparatus, 12 Communication control unit, 14 Switching control part, 20 Packet processing circuit, 30 Search circuit, 32 Position detection circuit, 33 Comparison circuit, 34 Index circuit, 35 Comparison circuit, 36 Binary search circuit, 40 Process execution circuit 50 first database, 57 user database, 60 second database, 100 communication control system, 110 operation monitoring server, 120 connection management server, 130 message output server, 140 log management server, 150 database server, 160 URL database, 161 virus / Phishing site list, 162 white list, 163 black list, 164 common category list, 380 mask circuit, 382 work memory.

(Prerequisite technology)
First, as a prerequisite technology, an outline of the configuration and operation of the communication control device and its peripheral devices will be described, and further, a URL filtering technology using the communication control device will be described.

  FIG. 1 shows a configuration of a communication control system according to the base technology. The communication control system 100 includes a communication control device 10 and various peripheral devices provided to support the operation of the communication control device 10. The communication control apparatus 10 of the base technology realizes a URL filtering function provided by an Internet service provider or the like. The communication control device 10 provided in the network path acquires an access request for content, analyzes the content, and determines whether to permit access to the content. If access to the content is permitted, the communication control apparatus 10 sends the access request to the server that holds the content. If access to the content is prohibited, the communication control apparatus 10 discards the access request and returns a warning message or the like to the request source. In the base technology, the communication control apparatus 10 receives an access request such as a “GET” request message of HTTP (HyperText Transfer Protocol), and the URL of the content of the access destination is a list of reference data for determining whether access is permitted or not. To determine whether or not access to the content is permitted.

  The peripheral devices include an operation monitoring server 110, a connection management server 120, a message output server 130, a log management server 140, and a database server 150. The connection management server 120 manages the connection to the communication control device 10. For example, when the communication control device 10 processes a packet transmitted from a mobile phone terminal, the connection management server 120 uses the information that uniquely identifies the mobile phone terminal included in the packet, and the user of the communication control device 10 Authenticate that Once authenticated, a packet sent from the IP address temporarily attached to the mobile phone terminal is sent to the communication control device 10 without being authenticated by the connection management server 120 for a certain period of time and processed. . The message output server 130 outputs a message to the access request destination or request source according to the access permission / rejection result determined by the communication control apparatus 10. The log management server 140 manages the operation history of the communication control apparatus 10. The database server 150 acquires the latest database from the URL database 160 and inputs it to the communication control apparatus 10. In order to update the database without stopping the operation of the communication control apparatus 10, the communication control apparatus 10 may have a backup database. The operation monitoring server 110 monitors the operation status of peripheral devices such as the communication control device 10, the connection management server 120, the message output server 130, the log management server 140, and the database server 150. The operation monitoring server 110 has the highest priority in the communication control system 100, and performs monitoring control of the communication control device 10 and all peripheral devices. As will be described later, the communication control device 10 is configured by a dedicated hardware circuit. However, the operation monitoring server 110 uses a boundary scan circuit by using a technique such as Japanese Patent No. 3041340 by the present applicant. By inputting / outputting monitoring data to / from the communication control device 10 or the like, the operation status can be monitored even during operation of the communication control device 10.

  As will be described below, the communication control system 100 of the base technology controls the communication control device 10 configured by a dedicated hardware circuit for speeding up by a server group having various functions connected to the periphery. With this configuration, various functions can be realized with the same configuration by appropriately replacing the software of the server group. According to the base technology, such a highly flexible communication control system can be provided.

  FIG. 2 shows a configuration of a conventional communication control device 1. The conventional communication control device 1 includes a communication control unit 2 on the reception side, a packet processing unit 3, and a communication control unit 4 on the transmission side. The communication control units 2 and 4 include PHY processing units 5a and 5b that perform processing on the physical layer of the packet, and MAC processing units 6a and 6b that perform processing on the MAC layer of the packet, respectively. The packet processing unit 3 includes a protocol processing unit that performs processing according to a protocol, such as an IP processing unit 7 that performs IP (Internet Protocol) protocol processing and a TCP processing unit 8 that performs TCP (Transport Control Protocol) protocol processing. And an AP processing unit 9 that performs application layer processing. The AP processing unit 9 performs processing such as filtering according to the data included in the packet.

  In the conventional communication control apparatus 1, the packet processing unit 3 is realized by software using a CPU that is a general-purpose processor and an OS that runs on the CPU. However, with such a configuration, the performance of the communication control device 1 depends on the performance of the CPU, and there is a limit to the implementation of a communication control device that can process a large-capacity packet at high speed. For example, in the case of a 64-bit CPU, the maximum amount of data that can be processed simultaneously at a time is 64 bits, and there has been no communication control device having higher performance. Further, since it is assumed that there is an OS having a general-purpose function, there is no possibility that a security hole exists, and maintenance work such as OS version upgrade is required.

  FIG. 3 shows the configuration of the communication control apparatus of the base technology. The communication control device 10 is configured by dedicated hardware using a wired logic circuit in place of the packet processing unit 3 realized by software including a CPU and an OS in the conventional communication control device 1 shown in FIG. A packet processing circuit 20 is provided. Rather than processing communication data with an OS and software that run on a CPU that is a general-purpose processing circuit, a dedicated hardware circuit for processing communication data is provided, thereby limiting the performance limit caused by the CPU, OS, etc. It is possible to overcome and realize a communication control device with high processing capability.

  For example, when searching for whether or not the data included in the packet includes reference data that is a criterion for filtering in order to perform packet filtering or the like, the communication data and the reference data are compared using the CPU. However, only 64 bits can be compared at a time, and even if it is attempted to improve the processing speed, there is a problem that the performance of the CPU reaches a peak. In the CPU, it is necessary to repeat the process of reading 64 bits from the communication data into the memory, comparing with the reference data, and then reading the next 64 bits into the memory. Time is rate limiting and processing speed is limited.

  On the other hand, in the base technology, a dedicated hardware circuit configured by a wired logic circuit is provided to compare communication data and reference data. This circuit includes a plurality of comparators provided in parallel to enable comparison of data lengths longer than 64 bits, for example, a data length of 1024 bits. In this way, by providing dedicated hardware, a large number of bit matching operations can be executed in parallel at the same time. The communication control apparatus 1 using a conventional CPU can process 1024 bits at a time, which can process only 64 bits at a time, and can dramatically improve the processing speed. If the number of comparators is increased, the processing capability is improved, but the cost and size also increase. Therefore, an optimum hardware circuit may be designed in consideration of desired processing performance, cost, size, and the like. The dedicated hardware circuit may be realized using an FPGA (Field Programmable Gate Array) or the like.

  Further, the communication control apparatus 10 of the base technology is configured by dedicated hardware using a wired logic circuit, and therefore does not require an OS (Operating System). For this reason, there is no need for OS installation, bug handling, version upgrade, and the like, and costs and man-hours for management and maintenance can be reduced. Unlike CPUs that require general-purpose functions, unnecessary functions are not included, so unnecessary resources are not used, and cost reduction, circuit area reduction, and processing speed improvement can be expected. . Furthermore, unlike conventional communication control devices that use an OS, it does not have an extra function, so it is unlikely that security holes will occur, and is resistant to attacks from malicious third parties via the network. Is excellent.

  The conventional communication control apparatus 1 processes a packet by software premised on a CPU and an OS, receives all data of the packet, performs protocol processing, and passes the data to the application. On the other hand, in the communication control device 10 of the base technology, since processing is performed by a dedicated hardware circuit, it is not necessary to start processing after receiving all data of the packet, and receive data necessary for processing. Then, the process can be started at an arbitrary time without waiting for the reception of subsequent data. For example, position detection processing in a position detection circuit described later can be started when position specifying data for specifying the position of comparison target data is received. As described above, since various processes can be executed in a floating manner without waiting for reception of all data, the time required to process packet data can be shortened.

  FIG. 4 shows the internal configuration of the packet processing circuit. The packet processing circuit 20 includes a first database 50 that stores reference data serving as a reference for determining the content of processing to be performed on communication data, and whether the received communication data includes reference data. Whether or not the search circuit 30 for searching by comparing the communication data with the reference data, and the second database 60 for storing the search result by the search circuit 30 and the contents of the processing to be executed on the communication data in association with each other. And a processing execution circuit 40 that processes communication data based on the search result by the search circuit 30 and the conditions stored in the second database 60.

  When the search circuit 30 divides the reference data stored in the first database 50 into three or more ranges, the position detection circuit 32 detects the position of the comparison target data to be compared with the reference data from the communication data. An index circuit 34 that is an example of a determination circuit that determines to which of the ranges the comparison target data belongs; a binary search circuit 36 that searches for reference data that matches the comparison target data in the determined range; including. Although any search technique can be used as a method for searching the comparison target data from the reference data, the binary search method is used in the base technique.

  FIG. 5 shows the internal configuration of the position detection circuit. The position detection circuit 32 includes a plurality of comparison circuits 33a to 33f for comparing the position specifying data for specifying the position of the comparison target data with the communication data. Here, six comparison circuits 33a to 33f are provided, but the number of comparison circuits may be arbitrary as will be described later. Communication data is input to each of the comparison circuits 33a to 33f with a predetermined data length, for example, shifted by 1 byte. In the plurality of comparison circuits 33a to 33f, the position specifying data to be detected and the communication data are compared in parallel at the same time.

  In the base technology, as an example for explaining the operation of the communication control apparatus 10, the character string “No. ##” included in the communication data is detected, and the number “##” included in the character string is detected. A case where a process of discarding a packet is performed when “#” is compared with the reference data and when the packet matches the reference data is permitted.

  In the example of FIG. 5, in order to detect the position specifying data “No.” for specifying the position of the number “####” from the communication data, the communication data “01No. 361. Each character is shifted and input to the comparison circuits 33a to 33f. That is, the comparison circuit 33a has “01N”, the comparison circuit 33b has “1No”, the comparison circuit 33c has “No.”, the comparison circuit 33d has “o.”, And the comparison circuit 33e has “ . 3 ”and“ 36 ”are input to the comparison circuit 33f. Here, the comparison circuits 33a to 33f simultaneously perform comparison with the position specifying data “No.”. Thereby, the comparison circuit 33c matches, and it is detected that the character string “No.” exists in the third character from the head of the communication data. In this way, it is detected that numerical data that is comparison target data exists after the position specifying data “No.” detected by the position detection circuit 32.

  If similar processing is performed by the CPU, first, the character string “01N” is compared with “No.”, and then the character string “1No” is compared with “No.”. Since it is necessary to execute comparison processing one by one, improvement in detection speed cannot be expected. On the other hand, in the communication control apparatus 10 of the base technology, by providing the plurality of comparison circuits 33a to 33f in parallel, simultaneous parallel comparison processing that cannot be performed by the CPU becomes possible, and the processing speed is remarkably improved. be able to. As the number of comparison circuits increases, the number of positions that can be compared simultaneously increases, so the detection speed also improves.However, considering the cost, size, etc., a sufficient number of comparison circuits are required to obtain the desired detection speed. What is necessary is just to provide.

  The position detection circuit 32 may be used not only for detecting position specifying data but also for detecting a character string for general use. Further, not only the character string but also the position specifying data may be detected in bit units.

  FIG. 6 shows an example of internal data of the first database. In the first database 50, reference data serving as a reference for determining processing contents such as packet filtering, routing, switching, and replacement is sorted and stored according to some sort condition. In the example of FIG. 6, 1000 pieces of reference data are stored.

  In the first record of the first database 50, an offset 51 indicating the position of the comparison target data in the communication data is stored. For example, in a TCP packet, since the data configuration in the packet is determined in units of bits, if a position such as flag information for determining the processing content of the packet is set as the offset 51, only necessary bits are set. Since the processing contents can be determined by comparing the two, the processing efficiency can be improved. Even if the data structure of the packet is changed, it can be dealt with by changing the offset 51. The first database 50 may store the data length of the comparison target data. As a result, the comparison can be performed by operating only the necessary comparators, so that the search efficiency can be improved.

  When the reference data stored in the first database 50 is divided into three or more ranges 52a to 52d, the index circuit 34 determines to which of the ranges the comparison target data belongs. In the example of FIG. 6, 1000 pieces of reference data are divided into four ranges 52a to 52d, 250 pieces each. The index circuit 34 includes a plurality of comparison circuits 35a to 35c that compare the reference data at the boundary of the range with the comparison target data. By comparing the comparison target data with the boundary reference data simultaneously in parallel by the comparison circuits 35a to 35c, it is possible to determine in which range the comparison target data belongs by one comparison process.

  The boundary reference data input to the comparison circuits 35 a to 35 c of the index circuit 34 may be set by a device provided outside the communication control device 10, or the reference data at a predetermined position in the first database 50 is previously stored. You may make it input automatically. In the latter case, even if the first database 50 is updated, the reference data at a predetermined position in the first database 50 is automatically input to the comparison circuits 35a to 35c. Processing can be executed.

  As described above, when the binary search is executed by the CPU, a plurality of comparisons cannot be executed simultaneously. However, in the communication control device 10 of the base technology, by providing a plurality of comparison circuits 35a to 35c in parallel, Simultaneous parallel processing can be performed, and the search speed can be remarkably improved.

  When the range is determined by the index circuit 34, the binary search circuit 36 executes a search by the binary search method. The binary search circuit 36 further divides the range determined by the index circuit 34 into two, and compares the reference data at the boundary position with the comparison target data to determine which range it belongs to. The binary search circuit 36 includes a plurality of comparison circuits for comparing the reference data and the comparison target data in bit units, for example, 1024 in the base technology, and simultaneously executes 1024-bit bit matching. When it is determined which of the two divided ranges, the reference data at the boundary position is read by dividing the range into two and compared with the comparison target data. Thereafter, this process is repeated to further limit the range, and finally, reference data that matches the comparison target data is searched.

  The operation will be described in more detail using the example described above. In the communication data shown in FIG. 5, the comparison target data following the position specifying data “No.” is the number “361”. Since there is a space for one character between the position specifying data “No.” and the comparison target data “361”, the offset 51 is set to “8” bits in order to remove this space from the comparison target data. Is set. The binary search circuit 36 skips “8” bits, that is, one byte, from the communication data following the position specifying data “No.”, and reads “361” as the comparison target data.

  “361” is input as comparison target data to the comparison circuits 35a to 35c of the index circuit 34, and reference data “378” at the boundary between the ranges 52a and 52b is input to the comparison circuit 35a as reference data. The reference data “704” at the boundary between the ranges 52b and 52c is input to 35b, and the reference data “937” at the boundary between the ranges 52c and 52d is input to the comparison circuit 35c. The comparison circuits 35a to 35c perform comparison at the same time, and it is determined that the comparison target data “361” belongs to the range 52a. Thereafter, the binary search circuit 36 searches whether or not the comparison target data “361” exists in the reference data.

  FIG. 7 shows another example of internal data of the first database. In the example shown in FIG. 7, the number of reference data is less than the number of data that can be held in the first database 50, here 1000. At this time, the first database 50 stores the reference data in descending order from the last data position. Then, 0 is stored in the remaining data. As a database loading method, data is placed from the back of the loading area without placing data from the beginning, and if there is a space at the beginning of the loading area, all the space is zero-suppressed, so the database is always full. The maximum time for binary search can be made constant. Further, when “0” is read as the reference data during the search, the binary search circuit 36 can determine the range without performing the comparison and can proceed to the next comparison because the comparison result is self-explanatory. Thereby, the search speed can be improved.

  In the software processing by the CPU, when the reference data is stored in the first database 50, the reference data is stored in ascending order from the first data position. For example, the maximum value is stored in the remaining data. In this case, the comparison process as described above cannot be omitted in the binary search. The comparison technique described above is realized by configuring the search circuit 30 with a dedicated hardware circuit.

  FIG. 8 shows still another example of the internal data of the first database. In the example shown in FIG. 8, the reference data is not equally divided into three or more ranges, but the number of reference data belonging to the range is uneven, such as 500 for the range 52a and 100 for the range 52b. It has become. These ranges may be set according to the distribution of the appearance frequency of the reference data in the communication data. That is, the ranges may be set so that the sum of the appearance frequencies of the reference data belonging to the respective ranges is substantially the same. Thereby, search efficiency can be improved. The reference data input to the comparison circuits 35a to 35c of the index circuit 34 may be changeable from the outside. Thereby, a range can be set dynamically and search efficiency can be optimized.

  FIG. 9 shows a configuration of a comparison circuit included in the binary search circuit. As described above, the binary search circuit 36 includes 1024 comparison circuits 36a, 36b,. Each of the comparison circuits 36a, 36b,... Receives the reference data 54 and the comparison target data 56 one bit at a time, and compares them. The internal configurations of the comparison circuits 35a to 35c of the index circuit 34 are the same. In this way, by executing the comparison process with a dedicated hardware circuit, a large number of comparison circuits can be operated in parallel and a large number of bits can be compared simultaneously, so that the comparison process can be speeded up. .

  FIG. 10 shows an example of internal data of the second database. The second database 60 includes a search result column 62 for storing a search result by the search circuit 30 and a processing content column 64 for storing the content of processing to be executed on communication data, and corresponds the search result to the processing content. Hold it. In the example of FIG. 10, a condition is set such that when the reference data is included in the communication data, passage of the packet is permitted, and when the reference data is not included, the packet is discarded. The process execution circuit 40 searches the second database 60 for process contents based on the search result, and executes the process on the communication data. The processing execution circuit 40 may also be realized by a wired logic circuit.

  FIG. 11 shows another example of internal data of the second database. In the example of FIG. 11, the processing content is set for each reference data. When packet replacement is performed, replacement destination data may be stored in the second database 60. When packet routing or switching is performed, information on the route may be stored in the second database 60. The process execution circuit 40 executes processes such as filtering, routing, switching, and replacement stored in the second database 60 according to the search result by the search circuit 30. As shown in FIG. 11, when setting the processing content for each reference data, the first database 50 and the second database 60 may be integrated.

  The first database and the second database are rewritable from the outside. By exchanging these databases, various data processing and communication control can be realized using the same communication control device 10. In addition, two or more databases storing reference data to be searched may be provided to perform multi-stage search processing. At this time, two or more databases that store search results and processing contents in association with each other may be provided to realize more complicated conditional branching. As described above, when a plurality of databases are provided to perform multi-stage search, a plurality of position detection circuits 32, index circuits 34, binary search circuits 36, etc. may be provided.

  The data used for the comparison described above may be compressed by the same compression logic. In comparison, if the comparison source data and the comparison destination data are compressed by the same method, the same comparison as usual is possible. As a result, the amount of data loaded at the time of comparison can be reduced. If the amount of data to be loaded is reduced, the time required to read data from the memory is reduced, so that the overall processing time can also be reduced. Further, since the amount of the comparator can be reduced, it is possible to contribute to downsizing, weight reduction, and cost reduction of the apparatus. The data used for the comparison may be stored in a compressed form, or may be compressed after being read from the memory and before the comparison.

  FIG. 12 shows another configuration example of the communication control apparatus of the base technology. The communication control apparatus 10 shown in this figure has two communication control units 12 having the same configuration as the communication control apparatus 10 shown in FIG. Moreover, the switching control part 14 which controls operation | movement of each communication control unit 12 is provided. Each communication control unit 12 has two input / output interfaces 16 and is connected to two networks on the upstream side and the downstream side via the input / output interfaces 16. The communication control unit 12 inputs communication data from one of the networks and outputs the processed data to the other network. The switching control unit 14 switches the direction of communication data flow in the communication control unit 12 by switching input / output of the input / output interface 16 provided in each communication control unit 12. Thereby, not only one direction but two-way communication control becomes possible.

  The switching control unit 14 may perform control so that one of the communication control units 12 processes an inbound packet and the other processes an outbound packet, or may control both to process an inbound packet. May handle outbound packets. Thereby, for example, the direction of communication to be controlled can be made variable in accordance with the traffic status and purpose.

  The switching control unit 14 may acquire the operation status of each communication control unit 12 and switch the communication control direction according to the operation status. For example, when one communication control unit 12 is in a standby state and the other communication control unit 12 is operating, when it is detected that the communication control unit 12 has stopped due to a failure or the like, The communication control unit 12 may be operated. Thereby, the fault tolerance of the communication control apparatus 10 can be improved. Further, when maintenance such as database update is performed on one communication control unit 12, the other communication control unit 12 may be operated as an alternative. Thereby, maintenance can be performed appropriately without stopping the operation of the communication control apparatus 10.

  Three or more communication control units 12 may be provided in the communication control device 10. For example, the switching control unit 14 acquires the traffic status, and controls the communication direction of each communication control unit 12 so that more communication control units 12 are allocated to the communication control process in the direction with a large amount of communication. May be. Thereby, even if the communication amount in a certain direction increases, it is possible to minimize a decrease in communication speed.

  A part of the communication control unit 2 or 4 may be shared between the plurality of communication control units 12. A part of the packet processing circuit 20 may be shared.

The following aspects can be considered as the data processing apparatus described above.
[Aspect 1]
A first storage unit that stores reference data serving as a reference for determining the content of processing to be performed on the acquired data;
A search unit for searching whether or not the reference data is included in the data by comparing the data and the reference data;
A second storage unit that stores the search result by the search unit and the content of the process in association with each other;
A processing unit that executes processing associated with the search result for the data based on the search result,
The data processing device, wherein the search unit is configured by a wired logic circuit.

[Aspect 2]
2. The data processing apparatus according to aspect 1, wherein the wired logic circuit includes a plurality of first comparison circuits that compare the data and the reference data in bit units.

[Aspect 3]
2. The data processing apparatus according to claim 1, wherein the search unit includes a position detection circuit that detects a position of comparison target data to be compared with the reference data from the data.

[Aspect 4]
In the data processing device according to aspect 3, the position detection circuit includes a plurality of second comparison circuits that compare the data with position specifying data for specifying the position of the comparison target data, and the plurality of second comparison circuits. A data processing apparatus, wherein the data is inputted to the circuit by shifting the position by a predetermined data length and compared in parallel with the position specifying data.

[Aspect 5]
In the data processing device according to any one of aspects 1 to 2, the search unit includes a binary search circuit that searches whether the reference data is included in the data by a binary search. Data processing device.

[Aspect 6]
In the data processing device according to aspect 5, when the number of data of the reference data is smaller than the number of data that can be held in the first storage unit, the reference data is stored in descending order from the last data position of the first storage unit. A data processing apparatus that stores data and stores 0 in the remaining data.

[Aspect 7]
In the data processing device according to any one of aspects 1 to 6, the search unit should compare with the reference data when dividing the plurality of reference data stored in the first storage unit into three or more ranges. A data processing apparatus comprising: a determination circuit that determines to which of the ranges the comparison target data belongs.

[Aspect 8]
In the data processing device according to aspect 7, the determination circuit includes a plurality of third comparison circuits that compare the reference data of the boundary of the range with the comparison target data, and the comparison target data is generated by the plurality of third comparison circuits. A data processing apparatus for simultaneously determining which of the three or more ranges belongs in parallel.

[Aspect 9]
9. The data processing device according to aspect 8, wherein the reference data stored at a predetermined position in the first storage unit is input to the third comparison circuit as reference data for the boundary. .

[Aspect 10]
The data processing device according to aspect 7 or 8, wherein the range is set according to a distribution of appearance frequencies of the reference data in the data.

[Aspect 11]
In the data processing device according to any one of aspects 1 to 10, the first storage unit further stores information indicating a position of comparison target data in the data, and the search unit stores information indicating the position. A data processing apparatus that extracts the comparison target data based on the data.

[Aspect 12]
The data processing device according to any one of aspects 1 to 11, wherein the first storage unit or the second storage unit is provided to be rewritable from the outside.

[Aspect 13]
In the data processing device according to any one of aspects 1 to 12, when the search unit acquires data to be compared with the reference data without waiting for acquisition of all data of the communication packet, A data processing apparatus which starts comparison of reference data.

[Aspect 14]
A plurality of the data processing devices according to any one of the first to thirteenth aspects are provided, and each of the data processing devices includes two interfaces for inputting / outputting data to / from a communication line. A data processing apparatus, wherein the direction of processing the data is variably controlled by switching the output.

  Next, a URL filtering technique using the above-described communication control device 10 will be described.

  FIG. 13 shows the internal configuration of the packet processing circuit 20 for URL filtering. The packet processing circuit 20 includes a user database 57, a virus / phishing site list 161, a white list 162, a black list 163, and a common category list 164 as the first database 50. The user database 57 stores information on users who use the communication control device 10. The communication control apparatus 10 receives information identifying the user from the user, and matches the information received by the search circuit 30 with the user database 57 to authenticate the user. As information for identifying a user, a source address stored in an IP header of a TCP / IP packet may be used, or a user ID and a password may be received from the user. In the former case, since the storage location of the source address in the packet is determined, it is not necessary to detect the location by the location detection circuit 32 when matching with the user database 57 in the search circuit 30, and the source address is used as the offset 51. It is only necessary to specify the storage location. If it is authenticated that the user is registered in the user database 57, then the URL of the content includes a virus / phishing site list 161, a white list 162, and a black list 163 in order to determine whether or not access to the content is permitted. , And the common category list 164. Since the white list 162 and the black list 163 are provided for each user, when the user is authenticated and the user ID is uniquely determined, the white list 162 and the black list 163 of the user are given to the search circuit 30.

  The virus / phishing site list 161 stores a list of URLs of contents including computer viruses and a list of URLs of “罠” sites used for phishing scams. An access request for the content of the URL stored in the virus / phishing site list 161 is rejected. As a result, even if the user is not aware or deceived and tries to access a virus site or phishing site, the user can be appropriately prohibited from access and protected from the damage caused by the virus or phishing scam. it can. In addition, since the list of virus sites and phishing sites is stored in the user's terminal and access is not restricted on the terminal side, access restriction is performed centrally by the communication control device 10 provided in the communication path, so that more reliable In addition, it is possible to restrict access efficiently. The communication control apparatus 10 acquires and holds a list of authenticated sites that have been certified by a certification authority as being a legitimate site that is not a virus site or a phishing site, and permits access to URLs stored in the list. You may do it. In addition, when a legitimate site is hijacked due to hacking, etc. and a virus is incorporated or used for phishing, legitimate site operators are hijacked in the virus / phishing site list 161 The URL of the site may be registered, and access may be temporarily prohibited until the site is restored to a normal state. Further, information such as an IP number, a TCP number, and a MAC address may be combined and checked together with the URL list. As a result, a more accurate prohibition condition can be set, and thus virus sites and phishing sites can be filtered more reliably.

  The white list 162 is provided for each user, and stores a list of URLs of contents permitted to be accessed. The black list 163 is provided for each user, and stores a list of URLs of contents whose access is prohibited. 14A shows an example of internal data of the virus / phishing site list 161, FIG. 14B shows an example of internal data of the white list 162, and FIG. 14C shows an example of the black list 163. An example of internal data is shown. The virus / phishing site list 161, the white list 162, and the black list 163 have a category number column 165, a URL column 166, and a title column 167, respectively. The URL column 166 stores URLs of contents that are permitted or prohibited to be accessed. The category number column 165 stores content category numbers. The title column 167 stores the title of the content.

  The common category list 164 stores a list for classifying the content indicated by the URL into a plurality of categories. FIG. 15 shows an example of internal data of the common category list 164. The common category list 164 also includes a category number column 165, a URL column 166, and a title column 167.

  The communication control apparatus 10 extracts the URL included in the “GET” request message or the like, and whether the URL is included in the virus / phishing site list 161, the white list 162, the black list 163, or the common category list 164. The search circuit 30 searches for whether or not. At this time, for example, a character string “http: //” may be detected by the position detection circuit 32, and a data string following the character string may be extracted as target data. The extracted URL is matched with the reference data of the virus / phishing site list 161, the white list 162, the black list 163, and the common category list 164 by the index circuit 34 and the binary search circuit 36.

  FIGS. 16A, 16B, 16C, and 16D show examples of internal data of the second database 60 for URL filtering. FIG. 16A shows search results and processing contents for the virus / phishing site list 161. When the URL included in the GET request or the like matches the URL included in the virus / phishing site list 161, access to the URL is prohibited. FIG. 16B shows search results and processing contents for the white list 162. When the URL included in the GET request or the like matches the URL included in the white list 162, access to the URL is permitted. FIG. 16C shows search results and processing contents for the black list 163. When the URL included in the GET request or the like matches the URL included in the black list 163, access to the URL is prohibited.

  FIG. 16D shows search results and processing contents for the common category list 164. As shown in FIG. 16D, for the search result for the common category list 164, the user can individually set whether to permit or prohibit access to the contents belonging to the category for each category. it can. The second database 60 related to the common category list 164 is provided with a user ID column 168 and a category column 169. The user ID column 168 stores an ID for identifying the user. The category column 169 stores information indicating whether the user permits access to content belonging to the category for each of the 57 categories. When the URL included in the GET request matches the URL included in the common category list 164, whether or not access to the URL is permitted is determined based on the category of the URL and the user ID. In FIG. 16D, the number of common categories is 57, but other common categories may be used.

  FIG. 17 shows the priorities of the virus / phishing site list 161, white list 162, black list 163, and common category list 164. In the base technology, the priority is higher in the order of the virus / phishing site list 161, the white list 162, the black list 163, and the common category list 164. For example, the URL of the content permitted to be stored in the white list 162 is URL. However, if the URL is stored in the virus / phishing site list 161, access is prohibited as content including a computer virus or content used for phishing.

  Conventionally, when performing matching in consideration of such priorities using software, for example, the first hit is performed by matching in order from the list with the highest priority, or from the list with the lower priority Either matching was done in order, and then the one that was hit later was overwritten, or either method was taken. However, in the base technology, a search circuit 30a for matching the virus / phishing site list 161 and a search circuit 30b for matching the white list 162 are obtained by using the communication control device 10 configured by a dedicated hardware circuit. In addition, a search circuit 30c for matching the black list 163 and a search circuit 30d for matching the common category list 164 are provided, and each search circuit 30 performs matching in parallel at the same time. If there is a hit in a plurality of lists, the one with higher priority is adopted. Thereby, even if a plurality of databases are provided and priorities are set for them, the search time can be greatly reduced.

  Whether the virus / phishing site list 161, the white list 162, the black list 163, or the common category list 164 is prioritized to determine whether access is permitted may be set in the second database 60, for example. The conditions of the second database 60 may be rewritten according to which list has priority.

  In this way, when performing filtering based on URL using a plurality of databases, it is configured so that the priority can be set in the database and filtering processing according to the priority can be performed, and the virus / By giving the highest priority to filtering by the phishing site list 161, access to the virus site and phishing site can be surely prohibited regardless of the setting status of the white list 162 and the like by the user. Thereby, a user can be appropriately protected from the damage of a virus or a phishing scam.

  When access to the content is permitted, the process execution circuit 40 outputs a signal for notifying the message output server 130 of the fact. The message output server 130 sends out a “GET” request message to the server holding the content. When access to the content is prohibited, when the process execution circuit 40 outputs a signal for notifying the message output server 130 to that effect, the message output server 130 sends a “GET” request message to the access destination server. Discard without sending. At this time, a response message indicating that access is prohibited may be transmitted to the request source. Alternatively, it may be forcibly transferred to another web page. In this case, the process execution circuit 40 rewrites and sends the destination address and URL to those of the transfer destination. Information such as the response message and the transfer destination URL may be stored in the second database 60, the message output server 130, or the like.

  The message output server 130 uses a ping command or the like to confirm that the request source actually exists, and if it exists, confirms the state and outputs a message to the request source. Good. The message transmitted from the message output server 130 to the request source may be set for each user, for each content to be accessed, for each category, or for each database such as the white list 162 and the black list 163. It may be settable. For example, the screen displayed when access is prohibited may be customized and registered in the message output server 130 by the user. Further, as described above, when a legitimate site is hacked and access is temporarily restricted, a message for guiding to the mirror site of the legitimate site may be output.

  The message output server 130 may manage the message transmission history and use the message transmission history information for various controls. For example, if a large number of access requests are sent from the same request source in a short time, there is a possibility of a denial of service attack (DoS attack), and the request source is included in the access denial list. It may be registered and blocked without sending a packet from the request source to the request destination. Further, the message transmission history may be statistically processed and provided to a website administrator or the like. Thereby, a user's access history can be utilized for marketing, or it can be utilized for control of a communication situation. In addition, the number of message transmissions can be reduced or increased depending on the situation. For example, when an access request is transmitted from a specific IP number, it is possible to send many times as many messages as the one request message.

  With the above configuration and operation, access to inappropriate content can be prohibited. Further, since the search circuit 30 is a dedicated hardware circuit composed of an FPGA or the like, high-speed search processing is realized as described above, and filtering processing is executed while minimizing the influence on traffic. Can do. By providing such a filtering service, an Internet service provider or the like can increase added value and attract more users.

  The white list 162 or the black list 163 may be provided in common for all users.

(Embodiment)
Next, a technique for controlling a plurality of types of communication data in the communication control apparatus 10 described above will be described. For example, due to the exhaustion of IP addresses in IPv4, the transition to IPv6 with a larger address space is in progress, but both IPv4 and IPv6 packets are communicated during the transitional period, A technique for appropriately controlling both packets is required. In the present embodiment, among the plurality of types of communication data, according to the type of communication data, only the data to be searched is left and other data is masked to switch the data to be searched. explain.

  FIG. 18 shows a configuration of a packet processing circuit of the communication control apparatus according to the embodiment. The packet processing circuit 20 shown in FIG. 18 further includes a mask circuit 380 and a work memory 382 in addition to the configuration of the packet processing circuit 20 of the communication control apparatus 10 of the base technology shown in FIG. Other configurations and operations are the same as those of the base technology.

  In the present embodiment, an example of authenticating a transmission source user by searching a transmission source IP address of an IP packet acquired by the communication control device 10 from a user database 57 storing an IP address of a legitimate user's terminal. Will be described.

  In the present embodiment, the position detection circuit 32 functions as an extraction unit that extracts data of a predetermined length from a predetermined position of communication data as comparison target data. The position and data length of the communication data from which the position detection circuit 32 extracts comparison target data are set so that the search target data to be searched in the search circuit 30 is included regardless of the type of communication data. In the example of the present embodiment, the comparison target data is extracted so that the source IP address to be searched is included in both the IPv4 packet and the IPv6 packet.

  In IPv6, a “source IP address” of 128 bits is stored after the 65th bit from the top of the IP header. In IPv4, after the 65th bit from the beginning of the packet header, an 8-bit “Time to Live”, an 8-bit “Protocol”, and a 16-bit “Header Checksum” ”, 32-bit“ source IP address ”, 32-bit“ destination IP address (Destination Address) ”, variable-length“ Option ”and“ Padding ”are stored. Yes. Therefore, the position detection circuit 32 extracts 128 bits from the 65th bit of the IP header as comparison target data so that the transmission source IP address that is the search target data is included in any packet, and the mask circuit Send to 380.

  In this case, if it is an IPv6 packet, the position detection circuit 32 will just extract the “source IP address” as the comparison target data. The comparison target data is extracted in the form of an oval. The position detection circuit 32 notifies the mask circuit 380 of the IP version number stored in the IP header for the operation of the mask circuit 380.

  The mask circuit 380 masks data other than the search target data to be searched by the search circuit 30 among the comparison target data extracted by the position detection circuit 32 in accordance with the type of the acquired communication data. To supply. The mask circuit 380 refers to the “Version” of the IP header notified from the position detection circuit 32. If the version is “6”, the mask circuit 380 sends the extracted comparison target data to the index circuit 34 as it is. If the version is “4”, the mask circuit 380 temporarily stores the extracted comparison target data in the work memory 382 and masks data other than the “source IP address” in the comparison target data. That is, the mask circuit 380 masks 32 bits from the beginning of the comparison target data and 64 bits from the 65th bit. As a result, the comparison target data generated from the IPv4 packet is masked leaving only the “source IP address” to be searched. The mask circuit 380 sends the masked comparison target data to the index circuit 34.

  FIG. 19 shows an example of internal data of the user database 57. The user database 57 stores a list of IP addresses of user terminals as reference data in order for the communication control apparatus 10 to authenticate a user who is a transmission source of communication data. The user database 57 stores an IPv6 IP address and an IPv4 IP address, and both reference data have the same data length as the comparison target data extracted by the position detection circuit 32. Data at positions other than the position of the search target data in the comparison target data is masked according to the type of communication data to be compared with the reference data. That is, the IPv6 128-bit IP address is stored as it is, but the IPv4 32-bit IP address is the 33rd bit from the beginning of the 128-bit bit string that is the same as the bit length of the IPv6 IP address. To 64th bit, and “0” is set in the remaining bits.

  The mask circuit 380 uses the same data as the data stored in the reference data stored in the user database 57 at a position other than the position of the search target data in the comparison target data. Store in position. Therefore, in the example of the present embodiment, the mask circuit 380 stores “0” at the position where the comparison target data is to be masked. The data stored at the position to be masked may be arbitrary data as long as it is used in common with the reference data of the user database 57.

  The index circuit 34 and the binary search circuit 36 search the user database 57 for the comparison target data supplied from the mask circuit 380 in the same manner as the method described in the base technology. Thus, even when the position of the search target data in the comparison target data differs depending on the type of communication data, the reference data stored in the first database 50 and the comparison extracted by the position detection circuit 32 Since both of the target data are masked so that the search target data is included at the same position, the search can be executed using the same index circuit 34 and binary search circuit 36. Therefore, it is possible to search for desired data among communication data with a simple configuration.

  When the communication data before masking by the mask circuit 380 is required, the processing execution circuit 40 reads the original communication data not masked from the work memory 382 and performs necessary control. As described above, according to the technique of the present embodiment, it is possible to appropriately control a plurality of types of communication data.

  The mask circuit 380 may store data functioning as a wild card at a position other than the search target data in the comparison target data. The comparators of the index circuit 34 and the binary search circuit 36, when data functioning as a wild card is input, output a signal indicating that they match. The comparator that compares the data at the position where the wild card is stored may be treated as if a signal indicating that the two match is output without inputting the data. In this case, arbitrary data may be stored in the reference data of the user database 57 at the position to be masked.

  Of the reference data in the user database 57, data that functions as a wild card may be stored at a position other than the position of the search target data in the comparison target data. In this case, the mask circuit 380 and the work memory 382 may not be provided.

  The process execution circuit 40 may convert the IP address of the user who has been successfully authenticated. For example, when the user is identified using the IPv4 IP address in the first database 50, the second database 60, or another communication device, the process execution circuit 40 keeps the IPv4 IP address as it is, You may unify into IPv4 by converting the IP address of IPv6 into the IP address of IPv4. Conversely, it may be converted to IPv6 by converting an IPv4 IP address into an IPv6 IP address. When the user is identified using the user ID in the first database 50, the second database 60, or another communication device, the process execution circuit 40 uses the IPv4 and IPv6 IP addresses as the user ID. May be converted to

  The communication control apparatus 10 according to the present embodiment is a completely transparent communication device that does not have an IP address, and executes the above function without physically receiving communication data. That is, the communication control apparatus 10 captures communication data passing through the network, omits processing required for physical incoming calls such as protocol processing, performs the above-described processing, and retransmits the communication data to the network according to a predetermined condition. Put out. The conventional communication device receives and controls the communication data addressed to its own device, but the communication control device 10 according to the present embodiment captures the communication data that is not transmitted to the own device. To control. Therefore, the source and destination devices and the other communication devices provided in the communication path do not require any change in settings or the like due to the provision of the communication control device 10, and the presence of the communication control device 10 exists. It is possible to communicate without being conscious of Therefore, according to the technique of the present embodiment, the above-described communication control can be performed without greatly modifying the communication system. Moreover, since the communication control apparatus 10 of this Embodiment does not have an IP address, it is not attacked by a malicious hacker etc., and is excellent in security.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  The present invention can be applied to a communication control apparatus that controls communication.

Claims (5)

For a plurality of types of communication data, a database storing reference data serving as a reference for determining a method for controlling the communication data;
An extraction unit that extracts data of a predetermined length as a comparison target data from a predetermined position of the acquired communication data so that the search target data to be searched for the reference data is included regardless of the plurality of types;
A mask circuit that masks data other than the search target data out of the extracted comparison target data according to the type of the acquired communication data;
A search circuit that searches the database for reference data contained in the masked comparison target data;
A process execution circuit for controlling the communication data according to a search result of the search circuit;
A communication control apparatus comprising:   The reference data stored in the database has the same data length as the comparison target data, and the position of the search target data in the comparison target data according to the type of communication data to be compared with the reference data The communication control apparatus according to claim 1, wherein data at positions other than is masked.   The mask circuit stores the same data as the data stored at the masked position among the reference data stored in the database at a position other than the search target data in the comparison target data. The communication control apparatus according to claim 2.   4. The communication control device according to claim 1, wherein the mask circuit stores data functioning as a wild card at a position other than the search target data in the comparison target data. 5. Extracting a predetermined length of data as a comparison target data from a predetermined position of the acquired communication data so as to include reference data serving as a reference for determining a method for controlling the communication data for a plurality of types of communication data;
Masking data other than the search target data to be searched by the search circuit from the extracted comparison target data according to the type of the acquired communication data, and supplying the masked data to the search circuit;
Searching the reference data included in the comparison target data from the database storing the reference data by the search circuit;
Controlling the communication data according to a search result;
A communication control method comprising:

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