JP6061480B2 - Communication device control method and communication device - Google Patents

Description

  The present invention relates to a communication device control method for determining a port number used for communication and a communication device that executes the control method.

As a protocol for communication apparatuses to communicate with each other, there is TCP (Transmission Control Protocol). In many common program environments, TCP operations are implemented as part of the OS. An application operating in the userland performs communication processing using TCP by using an API (Application Program Interface) prepared by an OS (Operation System). For example, in UNIX (registered trademark), this function is realized by an API called Socket.
In TCP, a 16-bit identifier called a port number is used to identify a transmission / reception application operating on a device that performs TCP communication. In order to prevent the same port number from being used between different applications, an OS that implements TCP performs a duplication check to confirm whether or not normal use of the port number has occurred. For example, in UNIX (registered trademark), when an application performs a duplication check in a bind function that specifies a port number, and another application already uses the port number, the bind function call is returned with an error. It has become. This allows the application to check whether the port number that it wants to use can actually be used. Further, when it cannot be used, it is possible to take measures such as using another port number.

JP-A-11-175439

However, depending on the development platform, there is a case where the above-described duplication check mechanism is not prepared. There are also development environments in which detailed operation specifications are not disclosed to application developers even if they are prepared. In such an environment, there is a concern that the application cannot confirm whether the port number that the user wants to use can actually be used, and misidentifies that the port number that cannot actually be used can be used.
The present invention has been made in view of the above problems, and it is an object of the present invention to make it possible to check whether a specific port number can be used even in a situation where the operation of the port number duplication check function is not clear. is there.

  The communication device of the present invention includes a connection unit that performs a connection process for connecting to a predetermined port number of a communication interface, and, if the connection process by the connection unit is successful, the connection unit until the connection process by the connection unit fails Control means for controlling the connection means to perform the connection processing while switching the port number to be performed, and processing for opening the port number that failed in the connection processing in response to the failure of the connection processing. An opening means to perform, a communication means for communicating with another communication device using the port number when the opening of the port number for which the connection processing has failed by the opening means, and the connection by the opening means Resuming means for resuming control by the control means when opening of the port of the port number that has failed in processing has failed It has a.

  According to the present invention, it is possible to confirm whether or not a specific port number can be used even in a situation where the operation of the port number duplication check function is not clear.

It is a figure which shows an example of the hardware constitutions of the communication apparatus concerning one Embodiment of this invention. It is a figure which shows an example of the functional block structure of the communication apparatus concerning one Embodiment of this invention. It is a flowchart showing the operation | movement flow of the communication apparatus concerning one Embodiment of this invention. It is a sequence chart showing operation | movement of the communication apparatus concerning one Embodiment of this invention.

  Hereinafter, the communication apparatus according to the present embodiment will be described in detail with reference to the drawings.

  FIG. 1 is a hardware configuration diagram of a communication device 100 according to the present embodiment.

  The display unit 101 performs various displays for the user. The operation unit 102 includes operation buttons, switches, and the like for the user to operate the communication apparatus 100. The display unit 101 and the operation unit 102 can also be configured by a touch panel. The storage unit 103 stores and manages various data such as wireless communication network information, data transmission / reception information, and communication device information. The power supply unit 104 supplies power to each unit of the communication device 100, and supplies power from an external power source and power of the built-in battery. The clock unit 105 measures time. The control unit 106 controls the communication device 100 according to a control program stored in the ROM 107 and RAM 108. The ROM 107 stores control instructions, that is, computer programs. The RAM 108 is used as a work area for the control unit 106. The control unit 106 executes each control program stored in the ROM 107 and the RAM 108, thereby constituting each unit in the description of FIGS.

  The antenna 111 is an antenna for performing wireless LAN communication. The wireless LAN antenna control unit 109 controls the antenna 111. The communication interface unit (communication IF) 110 performs communication processing such as network search, construction, connection, and management. In the present embodiment, the communication IF 110 is described as a wireless LAN interface compliant with the IEEE 802.11 standard.

  FIG. 2 is a functional block diagram of the communication device 200 that functionally represents the communication device 100.

  The functional block of the communication device 200 is a software configuration that is stored as a program in the ROM 107 and executed by the control unit 106. Part or all of the functional blocks of the communication terminal may be implemented as hardware. The block configuration of FIG. 2 is an example, and the role configuration of each block such as configuring the TCP processing unit 230 and the IP processing unit 240 as one block or distributing the TCP processing unit 230 into a plurality of blocks is illustrated in FIG. It is not limited to two examples.

  The server processing unit 210 is a processing unit that realizes a server function when communicating with an external communication device that is a communication partner. The process of FIG. 3 described later is included in the process of the server processing unit 210. The TCP processing unit 230 is a processing unit that implements a TCP (Transmission Control Protocol) communication process. The IP processing unit 240 is a processing unit that implements IP (Internet Protocol) communication processing. The Socket interface 220 implements an interface to the communication protocol processing unit of the TCP processing unit 230 and the IP processing unit 240. In the present embodiment, the TCP processing unit 230 and the IP processing unit 240 are mounted as part of an OS (operation system). The server processing unit 210 is implemented as an application. The Socket interface 220 is an interface located between the application and the OS.

  FIG. 3 is an operation flowchart when the control unit 106 of the communication apparatus 100 executes a control program stored in the ROM 107 and RAM 108 and starts communication processing with an external communication apparatus by wireless LAN communication. The control unit 106 of the communication apparatus 100 executes the process of FIG. 3 and starts data communication using the port number that can be opened.

  3 is described as being performed by the control unit 106, but the processing in FIG. 3 may be performed by the communication interface unit (wireless LAN interface unit) 110. Further, the processing in FIG. 3 is also processing performed by the functional block in FIG. 2 as described in FIG.

  When this process is started, the address acquisition unit of the control unit 106 of the communication apparatus 100 acquires the IP address assigned to the wireless LAN interface (S301). Subsequently, the setting unit of the control unit 106 temporarily sets a port number (n) used for communication with the external communication device (S302). In this embodiment, first, n is temporarily set to 49152 as a predetermined port number. Next, the connection unit of the control unit 106 attempts TCP connection processing to the port number determined in S302 of the IP address acquired in S301 (S303). When the TCP connection process is successful (Yes in S304), the determination unit of the control unit 106 determines that the communication device 100 cannot use the port number n. Then, the disconnection unit of the control unit 106 disconnects the connection to the port n (S305). After the disconnecting unit disconnects the connection to the port n, the setting unit of the control unit 106 changes the port number to be connected to another port number and tries to use the port number after the change. Specifically, 1 is added to n, and a new port number (n) used for communication with the external communication device is set temporarily (S306). If the new value of n does not exceed the maximum value set as the set value (No in S307), the connection unit of the control unit 106 again performs TCP connection processing for the port number added in S306 of the IP address acquired in S301. Try (S303). As a result of adding n in S306, when the value of n exceeds the maximum value determined as a setting value (Yes in S307), the setting unit of the control unit 106 determines that there is no port number that can be used by the communication device 100, and an error (S308) This process is terminated.

  If the TCP connection process fails as a result of the connection process in S303 (No in S304), the determination unit of the control unit 106 determines that the port number n that has failed in the TCP connection process can be used. Then, the port control unit of the control unit 106 opens the port number n for which the TCP connection process has failed as a standby port from the external communication device (S309). If the open process is successful (Yes in S310), the notification unit of the control unit 106 notifies the open port number n to the external communication device (S311), and the process is successfully completed. In the present embodiment, the communication apparatus 100 notifies the external apparatus of the standby port number n by transmitting a multicast packet including information of the port number n from the wireless LAN interface.

  If the open process in S309 has failed (No in S310), the port control unit of the control unit 106 determines that the port number n for which the open process has failed cannot be used. After that, the setting unit of the control unit 106 tries to use another port number, similarly to the case where the connection process of S303 fails.

  Next, an example of an operation flow when an application opens a standby port in the communication apparatus 100 will be described with reference to FIG.

  As a premise, before the application (server processing unit 210) of the communication apparatus 100 starts processing, the IP address 192.168.0.1 is assigned to the wireless LAN interface by the address assignment processing of the IP processing unit 240 (S401). . Further, it is assumed that port 49152 of the IP address has already been opened by the port opening process of the TCP processing unit 230 (S402). Note that any method may be used to set the IP address in S401. For example, it may be set using DHCP (Dynamic Host Configuration Protocol), or an IP address specified by a user operation may be set. Similarly, any method may be used for opening the port 49152 in S402. For example, the OS may be opened, or another application may be opened. Further, communication between the application (server processing unit 210) and the TCP processing unit 230 and communication between the application (server processing unit 210) and the IP processing unit 240 are performed via the Socket interface 220.

  When the application (server processing unit 210) starts connection waiting processing in the above-described state (S403), the application requests the OS IP processing unit 240 to notify the IP address assigned to the wireless LAN interface from the OS. (S404). The IP processing unit 240 of the OS notifies the application (server processing unit 210) of the IP address assigned to the wireless LAN interface, so that the application acquires the IP address assigned to the wireless LAN interface (S405).

  Subsequently, the application (server processing unit 210) attempts TCP connection to the TCP processing unit 230 of the OS addressed to the port 49152 of the IP address acquired in S405 (S406). Since port 49152 has already been opened in S402, the connection processing in S406 has been successful, and the TCP processing unit 230 notifies the application (server processing unit 210) that the connection processing has been successful (S407). Upon receiving the notification in S407, the application (server processing unit 210) determines that port 49152 cannot be used, and disconnects the connection established in S406 and S407 (S408 and S409). Subsequently, the application (server processing unit 210) changes the port number (S306 and S307 in FIG. 3) and sets the new port number to 49153. Then, TCP connection is attempted to the TCP processing unit 230 to the 49153 port of the IP address acquired in S405 (S410).

  Since port 49153 is not yet used in communication device 100 (not opened), the connection process in S410 fails, and TCP processing unit 230 notifies the application (server processing unit 210) of the connection failure (S411). ). Upon receiving the notification in S411, the application (server processing unit 210) determines that the port 49153 can be used, and tries to open the port 49153 to the TCP processing unit 230 (S412). The TCP processing unit 230 of the OS receives the request of S412 and opens port 49153, and notifies the application (server processing unit 210) of the processing result (success) (S414).

  When the application (server processing unit 210) succeeds in opening the port, the application (server processing unit 210) notifies the opened communication port number to the external communication device (S415). For notification of the port number to the external communication device, protocol data for notification from the TCP processing unit 230 and the IP processing unit 240 is added to the communication frame in accordance with an instruction from the application (server processing unit 210). Then, after the protocol data is added, the data is transmitted to the external communication device that is the communication partner via the communication interface unit 110.

  Upon receiving the notification in S415, the external communication device recognizes the connection destination port number (number 49153). The external communication apparatus performs TCP connection to the port number received in S415 (S416). The communication device 100 sequentially processes the packets received via the communication interface unit 110 by the IP processing unit 240 and the TCP processing unit 230. Then, the TCP processing unit 230 notifies the application (server processing unit 210) that the connection has been accepted, so that the connection using the port number (49153) with the external communication device is performed (S416).

  Thereafter, data communication (S417) becomes possible between the communication device 100 and the external communication device.

  The above is an example of a typical embodiment of the present invention, but the present invention is not limited to the embodiment described above and shown in the drawings, and can be appropriately modified and implemented without departing from the scope of the present invention. .

  In the above embodiment, the communication apparatus 100 communicates with an external communication apparatus using a wireless LAN interface, but the present invention is not limited to this. For example, the communication device 100 may include a wired LAN interface and communicate with an external communication device using the wired LAN interface. In that case, all the processes of S301, S303, S309, and S311 shown in FIG. 3 are executed for the wired LAN interface.

  In the above embodiment, the IP address of the interface that communicates with the external communication device is acquired (S301), and the connection to the acquired IP address is attempted (S303). It can be an address.

  In the above embodiment, the initial value of the port number (n) to be connected is 49152, but the present invention is not limited to this. An arbitrary value may be used as the initial value of n as long as the value is within the range defined as the port number specification.

  Further, after determining that the port number cannot be used, the port number to be next connected is assumed to be a value obtained by adding 1 to n (S306), and the connection process is repeated until n exceeds the set value. The present invention is not limited to this. For example, the port number to be connected next specified in S306 may be determined randomly within a certain range. The termination condition shown in S307 may be determined based on the number of times the connection process in S303 has been tried, or may be determined based on the elapsed time since the process in FIG. 3 was started.

  Further, when the port number n that has been successfully opened is notified to the external communication device (S311), the communication device 100 notifies this by transmitting a multicast packet from the wireless LAN interface. However, the present invention limits this. It is not a thing. For example, it may be notified by a broadcast packet or a unicast packet. Further, the notification may be performed using an interface other than the wireless LAN (infrared communication, Bluetooth (registered trademark), NFC (Near Field Communication), 3GPP mobile phone communication system (3G, LTE), etc.).

(Other examples)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

DESCRIPTION OF SYMBOLS 100 Communication apparatus which implements this invention 101 Display part 102 Operation part 103 Memory | storage part 104 Power supply part 105 Clock part 116 Control part 107 ROM
108 RAM
109 Wireless LAN Antenna Control Unit 110 Communication Interface Unit 111 Wireless LAN Antenna

Claims (9)

A communication device,
A connection means for performing connection processing for connecting to a predetermined port number of the communication interface in order to select a port number used in the communication when starting communication with another communication device ;
Control means for controlling the connection means to perform the connection process while switching the port number to be connected until the connection process by the connection means fails when the connection process by the connection means is successful;
An open means for performing processing for opening the port of the port number for which the connection processing has failed in response to the failure of the connection processing;
Successful open port of the connection process failed port by the open means, communication means for communicating with the other communication apparatus by using the port number,
A resuming means for resuming control by the control means when opening of the port of the port number for which the connection processing has failed by the open means;
A communication apparatus comprising:   The communication apparatus according to claim 1, further comprising notification means for notifying the other communication apparatus of the port number when the opening by the opening means is successful.   The communication apparatus according to claim 1, wherein the connection unit performs the connection process on an address assigned to the communication interface.   The communication apparatus according to claim 1, wherein the connection unit performs the connection process on a loopback address.   5. The communication apparatus according to claim 1, wherein the connection process is a connection process compliant with TCP (Transmission Control Protocol). 6.   6. The control unit according to claim 1, wherein if the connection unit does not fail in the connection process for each port number within a predetermined range, the control unit terminates the process with an error. 6. Communication equipment.   The communication apparatus according to claim 1, wherein if the connection unit does not fail the connection process within a predetermined time, the control unit ends the process with an error. A communication device control method comprising:
A connection step of performing connection processing for connecting to a predetermined port number of the communication interface in order to select a port number to be used in the communication when starting communication with another communication device ;
If the connection process is successful, a control step for controlling the connection process while switching the port number to be connected until the connection process fails,
In response to the failure of the connection process, an open step of performing a process for opening a port number that has failed in the connection process;
In the open process, if successfully opened the ports of the failed port number to the connection processing, and a communication step of using the port number for communicating with the other communication apparatus,
In the opening step, when opening of the port of the port number that failed in the connection process has failed, a resuming step of resuming control in the control step;
A control method characterized by comprising:   The program for operating a computer as a communication apparatus of any one of Claim 1 to 7.

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