CN101719921B - Method for generating routing protocol component in software development of reconfigurable router - Google Patents

Abstract

A method for generating a BGP routing protocol component in software development of a reconfigurable router belongs to the field of reconfigurable network research and is characterized by comprising the following steps: the description of the component function interface, the behavior, the environment and the basic static information, the step of selecting the components which form the required components from the component library to generate the components, and then the component interface function, the component function and the component performance test are carried out. The invention has the advantages of less coding workload, low coupling degree, good integration and high code reuse degree.

Description

Generation method of routing protocol components in reconfigurable router software development

technical field

A component generation method in reconfigurable router software development belongs to the research field of reconfigurable networks.

Background technique

The new service-oriented network technology system is a feasible idea for the future development of the Internet. The key to realize the service-oriented new network technology system is to study the open reconfigurable routing and switching node technology. The basis of the open reconfigurable routing and switching node technology is the component processing technology supported by the platform. Firstly, three levels of processing are defined—platform, component and component. Platform is a system that can be reconfigured to complete various tasks, component is a unit that can be reconfigured to achieve specific functions, and component is a module that can be reconfigured to implement specified processing.

Component generation, management and testing are important core components of the reconfigurable routing and switching software development environment, and an important supporting technology for realizing open reconfigurable routing and switching nodes. This method provides a component-based component generation framework, which can develop component unit library conveniently and quickly.

The component technology in the reconfigurable routing and switching platform is to make the router design and development like the machinery manufacturing industry, which can be assembled with various standard and non-standard parts, or like the construction industry, it can be built with various building materials. All kinds of buildings. The goal of componentization of routing and switching systems is to conveniently and dynamically integrate functional components that can be provided by different manufacturers, different units or individuals, and implemented on different operating systems or hardware platforms into an organism. These components are required to be interoperable. Realizing the componentization of routing and switching functions is a cutting-edge system design idea, which plays a vital role in promoting the healthy development of routing and switching equipment manufacturing and the entire network industry.

Components can be used in different environments, and can also be used in combination in the same environment, so components need to provide clear interface specifications to interact with the corresponding environment. Component encapsulation, design and external representation should be separated as much as possible. Components function externally or interact between components through the interface defined by the specification. Component users only need to know the interface of the component, and do not care about its internal implementation. This is the key to the separation of design and implementation. The component development platform should provide the rules of component interaction, and implement a container-like standard environment based on these rules. Therefore, it can be said that the component development platform truly provides a component development model that is isolated from the system, from the hardware, and from the environment.

The key to the development of component development platform is to study the current and future development of component technology and complete related work: what kind of components are needed in the system, internal basic structure and extended structure, basic attributes and extended attributes of components, methods of component interaction, and component connection rules , the environment in which the component exists, etc. The corresponding supporting technology and system structure will be reflected in the component development platform. Figure 1 shows the architecture of the reconfigurable routing and switching development environment.

This paper proposes that component-based component generation method is applied to router software, mainly to solve the problem of tailoring and reusability of router software. Because the router products of current router manufacturers are divided into series, the functions of different series are different, which is reflected in the software. However, it will consume a lot of manpower and material resources for router developers to develop different router software for different router series. Therefore, there is an urgent need for a method that can make software with low coupling, good tailoring, and high code reuse—that is, software componentization. Therefore, the description and generation method of the software component proposed by the present invention can achieve this purpose. The software after componentization can be easily tailored and reassembled to generate software with new functions.

The routing protocol component BGP, namely Border Gateway Protocol, is a protocol for exchanging routing information between gateways in autonomous network systems. BGP is an exterior gateway protocol designed for TCP/IP Internet and used between multiple autonomous domains. It is neither based on a pure link state algorithm nor a pure distance vector algorithm. Its main function is to exchange network reachability information with BGP in other autonomous domains. Each autonomous domain can run different interior gateway protocols. The BGP update information includes the paired information of the network number/autonomous domain path. The autonomous domain path includes the autonomous domain strings that must pass through to reach a specific network, and these update information are sent out through TCP to ensure the reliability of transmission.

Contents of the invention

The purpose of the present invention is to:

The method of describing and generating components in routing software is proposed, mainly to reduce code coupling, strengthen the independence of modules, solve the problem of tailoring and reusability of router software, and reduce the writing work of a large number of repetitive codes.

The present invention is characterized in that:

The method is realized according to the following steps in the reconfigurable routing and switching platform on the vxworks platform:

Step (1.): Component description, including: component interface specification description, component behavior description, component external feature description, component basic static information description, and component environment description, where:

Step (1.1): Description of component interface specification, including:

Step (1.1.1): Description of component input interface

The component input interface reflects the service provided by the environment for the component, and the input interface of the BGP routing protocol component includes:

BGP routing protocol component and TCP Socket interface to complete the reception of protocol messages,

The interface between the BGP routing protocol component and the user configuration management component CFM to complete the configuration of user commands,

The interface between the BGP routing protocol component and the routing management component is described in detail of the input interface, and the message format adopted is: source component id, destination component id, message type, routing table item 1,,,,, routing table item N ,

Step (1.1.2): Description of component output interface

The output interface of the component reflects the service provided by the component for the environment, and the output interface of the BGP routing protocol component includes:

BGP routing protocol component and TCP Socket interface to complete the sending of protocol messages,

The interface between the BGP routing protocol component and the user configuration management component CFM is used to complete the return of configuration results. The interface messages of the configuration message used are: source component id, destination id, message type, message length, configuration information 1,,,,, Configuration information M,

Step (1.2): Description of component behavior, including:

Constraints on the order of service calls in the interface,

Component concurrency constraints: whether the component's services accept concurrent access, whether there are data and services that require mutually exclusive access,

Abnormal conditions and various exception handling during the processing of the service,

Step (1.3): Description of the external characteristics of the component, including:

Requirements for sending and receiving external protocol messages of components: message format and trigger conditions for sending and receiving,

External time limit requirements of components, at least including: satisfying the duration of various timers of the protocol state machine and the processing steps after timeout,

The controllability of the component to the outside, at least includes: the form and format of configuration information input that the component accepts, and the feedback information during configuration,

Step (1.4): A description of the environment of the component, including at least: the operating system and hardware platform as well as the compiler and existing links,

Step (1.5): Description of the basic static information of the component, including: component identification ID, component of the BGP routing protocol, BGP protocol number identification, component name, component type, description of all services and operations provided by the component externally, and interface description , component constraints;

Step (2): Component Generation

Step (2.1): Coding to realize component functions

Step (2.1.1): select the required meta-components from the meta-component library, at least including: routing table entry binary tree, linked list and message queue,

Step (2.2.2): Name the component to be realized,

Step (2.1.3): Modify the selected meta-component code according to the configuration, and pack it into the component to be generated,

Step (2.2): Code the component interface,

Step (2.3): compile the code generated in step (2.1) and step (2.2), generate an executable target file,

Step (2.4): Put the component obtained in step (2.2) into the component library, copy the component file into the specified directory, and add the component to the component table.

When there is no meta-component of the component to be developed in the meta-component library: firstly name the component to be realized, and secondly define each interface function independently.

In the process of generating components, the invention has the advantages of less coding workload, low coupling degree, good integration and high code reuse. The development cycle of components is relatively short.

Description of drawings

Figure 1. Schematic diagram of the architecture of the reconfigurable routing and switching development environment.

Figure 2. Schematic diagram of component development steps.

Fig. 3. Interface message format of BGP protocol component and routing management component.

Fig. 4. Interface message format of BGP protocol component and user configuration management component.

Figure 5. Interface message format of BGP protocol component and device management component.

Detailed ways

Based on the reconfigurable router software development environment, combined with the generation of routing protocol BGP components, the generation and management of components are realized according to the following steps and functional requirements:

Step (1.): Description of the component

Component description is the basis of component retrieval technology. Component description also provides a means for component reusers to understand and use components. In component management, component description plays a very important role. The component development platform must understand components through component description files to manage components and improve the interoperability between components.

Step (1.1): Description of component interface specification:

It is necessary to describe the input interface and output interface of the component. The input interface of a component represents the services provided by the environment, and the output interface represents the services it provides to the environment. The input and output interfaces of components determine the connection between components.

Step (1.1.1): Describe the input interface of the component:

Including interface type and interface details. The interface types include messages, pipes, semaphores, signals, and shared global variables. The detailed description of the interface is to clearly describe the specific format definition of the type of interface used, such as the message format of the message type interface.

The input interfaces of BGP components include:

a. BGP protocol component and TCP Socket interface to complete the reception of protocol messages.

b. The interface between the BGP protocol component and the user configuration module to complete the user command configuration.

Command example:

Router bgp as mum enables the bgp component

Neighbor ip remote as mum配置bgp邻居

Neighbor ip remote as mum configure bgp neighbor

c. The interface between the BGP protocol component and the routing management component to receive the routing update information of the routing management module. Taking the interface of the BGP protocol component and the routing management component as an example, carry out the detailed description of the input interface (see accompanying drawing 3):

Step (1.1.2): The method of describing component output interface is the same as 1.1.1.

The output interfaces of BGP components include:

a. The BGP protocol components interface with the TCP Socket to complete the sending of the protocol message.

b. The interface between the BGP protocol component and the user configuration management component to return the configuration result.

c. The interface between the BGP protocol component and the routing management component sends the routing information to the routing management component to complete the routing update of the global routing table.

The following takes the interface between the BGP protocol component and the configuration management component CFM as an example to describe the details of the output interface.

Interface message of configuration information (see Figure 4):

Message interface of interface information (see accompanying drawing 5):

Step (1.2): Describe component behavior. Include a description of the following points:

● Constraints on the order of service calls in the interface;

● Concurrency constraints of components: whether its services accept concurrent access; whether there are data and services that require mutually exclusive access, and if so, list them.

●Exceptional conditions and handling of various exceptions during service processing.

Step (1.3): Describe the external characteristics of the component.

Step (1.3.1): Describe the sending and receiving requirements of the component's external protocol messages: the specific content included is the message format and the triggering conditions for sending and receiving.

Step (1.3.2): Describe the external time limit requirements of the component, mainly including the duration of various timers satisfying the protocol state machine and the processing steps after timeout.

Step (1.3.3): Describe the controllability of the component to the outside, mainly including the form and format of configuration information input that the component accepts, and the feedback information during configuration.

Step (1.4): Describe the environment of the component. Here it refers to the large software environment where the component is located, including the operating system and hardware platform, as well as the compiler and the existing link library.

Step (1.5): Organize the basic static information of the components, including the following specific details:

●Component identification (ID): unique identification in the system.

Based on the uniqueness of each protocol number, the routing protocol component can be identified by the protocol number.

● Component name.

The routing protocol BGP component is directly named "component BGP".

●Component type (basic\business).

The BGP component type is a routing protocol.

●Component function description: description of all services (functions) and operations provided by the component.

The main functions provided by BGP are: one is to generate and maintain a routing table based on its own algorithm for use by the routing management module; the other is to publish the network reachability information of the autonomous system to other autonomous systems,

●Interface description.

■ Interfaces provided to other components or programs

interface name (parameter list): return value (including exceptions).

To enable the BGP protocol, the system needs to call the interface function bgp_open() provided by the BGP component to the system. The parameter of this function is empty, and the return value is int type. It returns 0 for successful startup and 1 for startup failure.

■ Interfaces that require support from other programs or components.

BGP requires the system to provide system calls such as timers and message processing, and also requires sending and receiving messages through TCP.

●Component constraints (semantic description): For example, an operation can only be called if a certain property falls within the specified range, and an operation must be called after another operation is called.

When BGP establishes a socket connection, operations such as listen and connet must be performed after the bind operation.

●Other component characteristics:

■With or without state, whether it can serve multiple client programs.

■ Deployment description: the constraints of deployment. Such as the operating system the component runs on, the required space, etc.

■Customization ability: customize the services that components can provide.

■Component maintainer information (name\creation date).

■ Component version.

Step (2): Generation of components

Step (2.1): Code to realize the function of the component, mainly in the following two ways:

●Method 1: Developers can use the meta-components in the meta-component library to compose components, the process is as follows

■ Select the meta-components required to make up the component

■Name the component to be realized

■Select component framework and template

■The system partially modifies the selected component code according to the developer's choice and configuration (including file name modification, makefile modification, project file modification, etc.), and packages it into the project of the component to be generated

■The developer edits the code automatically generated by the system from the configuration

●Method 2: If there is no meta-component that meets the component to be developed in the component component library, the developer can completely independently develop the component into the library

■Name the component to be realized

■Developers independently define the functions of each interface

Step (2.2): According to the description of step 1, code to realize the interface of the component

Step (2.3): Compile the code generated in the above two steps to generate an executable object file

Step (2.4): Put the component into the component library, that is, copy the constituent files of the component into the designated directory, and add the component into the component table.

Step (3): component testing;

After the components are generated through the above steps, component testing is required.

Step (3.1): component interface function test;

For a single component, test the data transmission and reception of the interface defined in the component description to ensure that the data is correctly transmitted and received, and after the data is received correctly, the data is processed and the final result data is generated In line with expectations.

For bgp components, the details are as follows:

Whether the component bgp can execute corresponding actions by receiving the configuration command information of the configuration management component CFM. For example, after the bgp is configured to start running and the neighbors are configured, can the bgp component establish a tcp connection with the configured neighbors and carry out the route learning process. Whether Bgp can process normally after receiving the route, whether it can strive to save the route and deliver the route information to the route management component in the format specified in step 1.1.1.

Step (3.2): component function test;

For the developed components, test the functions that the components should have. Ensure that the function of the component conforms to the description of the function of the component.

For the bgp component, the specific component function test is: test whether the BGP component has learned the route from other bgp peers, whether other peers have learned the route from the local bgp protocol, and whether the local bgp component will learn The routing is correctly handed over to the routing management component.

Step (3.3): component performance test;

For components that can complete functions correctly, it is necessary to test the running time, occupied memory, processor, etc. of the components. Pass if the test results are as expected.

For the bgp component, a stress test can be performed: when 100,000 pieces of routing information are pushed into the component, check whether the bgp component has lost routes, and check whether the bgp component has correctly handed over all learned routes to the routing management component.

When traditional router software development adapts to new requirements, a lot of repetitive code writing is required. And for the reuse of existing code, it is not very ideal. Using the method of software componentization can improve code reuse and efficiency to a certain extent.

After strictly following steps 1, 2, and 3, a software component with complete functions and low coupling can be obtained.

Claims (2)

1. the generation method of the BGP (i.e. Border Gateway Protocol) routing protocol component in the reconfigurable router development, it is characterized in that, described method is to realize according to the following steps in reconfigurable routing exchange platform with vxworks platform: Step (1.): Component description, including: component interface specification description, component behavior description, component external feature description, component basic static information description, and component environment description, where: Step (1.1): Description of component interface specification, including: Step (1.1.1): Description of component input interface The component input interface reflects the service provided by the environment for the component, and the input interface of the BGP (i.e. Border Gateway Protocol) routing protocol component includes: BGP (i.e. Border Gateway Protocol) routing protocol component and TCP Socket interface to complete the reception of protocol messages, The interface between the BGP (i.e. Border Gateway Protocol) routing protocol component and the user configuration management component CFM to complete the configuration of user commands, The interface of the BGP (i.e. Border Gateway Protocol) routing protocol component and the routing management component carries out the detailed description of the input interface, and the message format adopted is: source component id, destination component id, message type, first routing entry 1, ......, the Nth routing table entry N, Step (1.1.2): Description of component output interface The output interface of the component reflects the service provided by the component for the environment, and the output interface of the BGP (ie Border Gateway Protocol) routing protocol component includes: BGP (i.e. Border Gateway Protocol) routing protocol component and TCP Socket interface to complete the sending of protocol messages, The interface between the BGP (i.e. Border Gateway Protocol) routing protocol component and the user configuration management component CFM is used to complete the return of the configuration result. The interface message of the configuration message used is: source component id, destination id, message type, message length, first Configuration information 1, ..., the Mth configuration information M, Step (1.2): Description of component behavior, including: Constraints on the order of service calls in the interface, Component concurrency constraints: whether the component's services accept concurrent access, whether there are data and services that require mutually exclusive access, Abnormal conditions and various exception handling during the processing of the service, Step (1.3): Description of the external characteristics of the component, including: Requirements for sending and receiving external protocol messages of components: message format and trigger conditions for sending and receiving, External time limit requirements of components, at least including: satisfying the duration of various timers of the protocol state machine and the processing steps after timeout, The controllability of the component to the outside, at least includes: the form and format of configuration information input that the component accepts, and the feedback information during configuration, Step (1.4): A description of the environment of the component, including at least: the operating system and hardware platform as well as the compiler and existing links, Step (1.5): Description of the basic static information of the component, including: component identification ID, the BGP (i.e. Border Gateway Protocol) routing protocol component, BGP (i.e. Border Gateway Protocol) protocol number identification, component name, component type, component Provide external descriptions of all services and operations, interface descriptions, and component constraints; Step (2): Component Generation Step (2.1): Coding to realize component functions Step (2.1.1): select the required meta-components from the meta-component library, at least including: routing table entry binary tree, linked list and message queue, Step (2.2.2): Name the component to be realized, Step (2.1.3): Modify the selected meta-component code according to the configuration, and pack it into the component to be generated, Step (2.2): Code the component interface, Step (2.3): compile the code generated in step (2.1) and step (2.2), generate an executable target file, Step (2.4): Put the component obtained in step (2.2) into the component library, copy the component file into the specified directory, and add the component to the component table. 2. the generation method of the BGP (i.e. Border Gateway Protocol) routing protocol component in the reconfigurable router development according to claim 1, it is characterized in that, when there is no meta-component of the component to be developed in the described meta-component library Time rules: first name the components to be realized, and then define the functions of each interface independently.

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