JPH0787480B2 - Multi-protocol processor - Google Patents

Description

The present invention relates to a communication protocol processing device in a data communication system.

2. Description of the Related Art FIG. 6 shows a block diagram of a conventional communication protocol processing device. In FIG. 6, reference numeral 1 is a communication protocol processing device having a communication function of the information processing device 30. Reference numeral 1'denotes a communication protocol processing device possessed by another information processing device on the network, and has the same function as 1. Reference numeral 2 is a transmission line to which the communication protocol processing device is connected. Reference numeral 3 denotes a network interface unit that transmits / receives data to / from the transmission path 2 in the communication protocol processing device 1. Reference numeral 4 denotes a processor, which performs communication protocol processing and comprehensive control of the communication protocol processing device 1. A memory 5 is used as a storage unit for the communication protocol processing program code of the processor 4 and communication data. Reference numeral 6 denotes a bus for mutual communication among the processor 4, the memory 5, the network interface unit 3, and the terminal interface unit 7, through which information such as control codes and communication data flows. A bus 8 is used by the information processing apparatus 30 to exchange data with the communication protocol processing apparatus 1 via the terminal interface unit 7.

In the above configuration example, the communication protocol processing devices 1 and 1 '
Data communication between them is performed as follows. The communication protocol processing device 1 ′ creates transmission data according to a protocol (for example, OSI protocol) defined in advance in this network system, and sends it to the transmission line 2.
The transmission data includes header information in which a source address, a destination address, a checksum, etc. are written. The structure of the header information is specified by the protocol used. The communication protocol processing device 1 that receives this data from the transmission line 2 analyzes the header information of the received data in the network interface unit 3 based on the protocol of the OSI lower layer protocol, and if the received data is addressed to itself, The received data is taken into the memory 5 via 6, the OSI upper layer communication protocol processing program is executed under the processor 4, and necessary information is transmitted to the information processing apparatus 30 via the terminal interface unit 7.
Further, if the received data is not addressed to itself, the network interface unit 3 retransmits the received data as it is to the transmission line 2 again.
Put it back up.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, the communication protocol processing as described above is possible only when the communication protocol processing device processes only one predetermined communication protocol (OSI protocol in this case). Each communication protocol processor has several different types of communication protocols (eg OSI and TCP).
/ IP and XNS) is implemented and the user is allowed to use an arbitrary protocol, proper protocol processing cannot be performed without knowing which protocol the received data follows.

It is an object of the present invention to provide a multi-protocol processing device which is capable of implementing a proper protocol process on received data by mounting a plurality of types of communication protocol processing programs on the communication protocol processing device.

Means for Solving Problems To process different types of communication protocols in a network system that performs data communication between information processing devices by selecting an arbitrary communication protocol from a plurality of types of feasible communication protocols A plurality of necessary communication protocol processing programs, means for assuming a communication protocol corresponding to the received data, means for extracting specific information from the header content of the received data based on the assumption, and using the specific information for the above The hypothesis means is provided with a judgment means for judging whether the hypothesis of the assumed communication protocol is correct, and when the data is received, the assumption means, the extraction means and the judgment means are executed to determine the communication protocol corresponding to the received data, and the plurality of types Select and execute the communication protocol processing program corresponding to the received data from the communication protocol It is configured to do.

Effect The present invention can determine the communication protocol used from the header information of the received data by the above-described configuration, and therefore changes the existing protocol by providing a special identifier for identifying the communication protocol. Multi-protocol processing is possible without adding.

Embodiment FIG. 1 shows a block diagram of a multi-protocol processing apparatus according to an embodiment of the present invention, in which the same parts as those in the conventional example of FIG. In FIG. 1, reference numeral 20 is a multi-protocol processing device having a communication function of the information processing device 30. Reference numeral 20 'is a multi-protocol processing device possessed by another information processing device on the network and has the same function as 20. Reference numeral 21 is a protocol determination unit that transmits and receives data between the multi-protocol processing device 20 and the transmission path 2, and particularly determines the protocol for received data.
A ROM 22 stores a plurality of types of communication protocol processing program codes, and a processing program corresponding to the protocol determined by the protocol determining unit 21 is loaded into the memory 5.

The operation of the multi-protocol processing device 20 of this embodiment configured as described above will be described below. For the sake of simplicity, the communication protocol implemented by the multi-protocol processor 20 is, as shown in FIG. 2, the upper four layers of the OSI protocol (application, presentation, session, and transport layers) and TCP. (Transmission
Control Protocol) and upper protocol combined into two types, transport layer and TC
It is assumed that P interfaces with a common lower layer protocol. The user process is generated by the information processing device 30 shown in FIG. When the multi-protocol processing device 20 of FIG. 1 receives the data addressed to itself from the transmission line 2, the protocol determining unit 21
The lower layer protocols shown in the figure are executed. Since the data processed by the lower layer protocol conforms to either the TCP or the transport layer protocol, its header part should have the data format shown in FIG. 3 or FIG. FIG. 3 is a block diagram of the TCP header, and FIG. 4 is a block diagram of the protocol data unit of the transport layer. Therefore, the protocol determination unit 21 executes the process shown in FIG. 5 to determine which protocol. The process 41 of FIG. 5 assumes the protocol of the received data.

Now, suppose that the protocol is TCP.
The process 42 extracts information characteristic of TCP from the header part of the data based on the TCP protocol. In the case of TCP, the structure of the header is as shown in Fig. 3, so the 17th byte from the beginning of the header is used as the information used for protocol judgment.
Extract the checksum written in the 18th byte. The process 43 determines the authenticity of the protocol assumed in the process 41 based on the information extracted in the process 42. In the case of TCP, the checksum of the received data is actually calculated, and if it matches the value of the checksum extracted in the process 42, it is determined that the assumed protocol is correct. If they do not match, it is determined that the hypothesized protocol was incorrect, and this time, in process 41, the OSI protocol is assumed.
In process 42, the header information is analyzed according to the OSI protocol. In the OSI protocol, the header part of the transport protocol data unit is configured as shown in Fig. 4, so the checksum value written in the variable part is extracted and used as the judgment material in the next process 43. To do. The position where the checksum value is stored can be known by using the value of LI that represents the length of the header portion in the first byte of the header and the bit pattern "11000011" for checksum identification. In process 43, the checksum is actually calculated for the received data by the method specified by the OSI protocol and processed.
The value is compared with the value obtained in 42 to make a judgment. When the correct protocol is determined by the determination of the process 43, the post-process of the process 44 is performed. Here, processing such as notifying the processor 4 of the protocol processing program to be loaded from the ROM 22 in FIG. Thereafter, this received data is taken into the memory 5 via the bus 6, and the protocol processing program loaded in the memory 5 is executed by the processor 4. Necessary information is transmitted to the information processing device 30 via the terminal interface unit 7, and a series of reception processing ends.

As described above, according to the present embodiment, the protocol of the received data can be reliably determined by the simple process of confirming the correctness of the checksum of the header information in the protocol determination unit 21.

Although the protocol processing program code is loaded from the ROM 22 to the memory 5 each time data is received by the processing 44 in the present embodiment, all the program codes of the ROM 22 may be resident in the memory 5.

Effects of the Invention As described above, according to the present invention, a plurality of protocols can be implemented by simply performing a simple process without changing an existing protocol or providing a special identifier for protocol identification. A network system for transferring data between the communication protocol processing devices can be constructed, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram of a multi-protocol processing apparatus according to an embodiment of the present invention, FIG. 2 is a layer diagram of a protocol implemented in the same embodiment, and FIG. 3 is a header structure of a TCP protocol handled in the same embodiment. FIG. 4 is a block diagram of a transport protocol data unit handled in the same embodiment, FIG. 5 is a diagram showing a process for determining a protocol in the same embodiment, and FIG. 6 is a communication protocol processing device of a conventional example. It is a block diagram. 1, 1 '... Communication protocol processor, 2 ... Transmission path, 3
...... Network interface unit, 4 ... Processor, 5 ... Memory, 6 ... Bus, 7 ... Terminal interface unit, 8 ... Bus, 20,20 '... Multi-protocol processing device, 21 ... Multi-protocol processing Device, 22 ... RO
M, 30 ... Information processing device.

Claims (1)

[Claims] 1. A network system for performing data communication between information processing devices by selecting an arbitrary communication protocol from a plurality of types of practicable communication protocols, and a plurality of communication systems required to process different types of communication protocols. Communication protocol processing program, means for assuming a communication protocol corresponding to received data, means for extracting specific information from the header content of the received data under the assumption, and the assumption means using the specific information. A determination means for determining whether the assumed communication protocol is correct or not is provided, and when the data is received, the above-mentioned assumption means, extraction means, and determination means are executed to determine the communication protocol corresponding to the received data, and from the plurality of types of communication protocols A multiprocessor that selects and executes a communication protocol processing program corresponding to the received data. Col processing apparatus.