基于嵌入式无线传输文件系统的研究与设计

发布时间：2018-05-25 04:42

本文选题：ARM + 嵌入式Linux　；参考：《电子科技大学》2012年硕士论文

【摘要】：论文针对专用嵌入式无线设备多用户模式文件传输系统做了深入的研究，改进并实现了基于专用无线嵌入式设备后台文件传输系统。主要进行了嵌入式设备操作系统定制裁剪移植，驱动加载，搭建无线组网平台以及在嵌入式设备有限的硬件资源条件下，对后台软件文件传输系统机制进行优化改进的工作。在提高系统的稳定性，安全性与系统程序执行效率，并保证系统的可应用性等方面取得了一些成果。本次研究针对通用的嵌入式设备，设计思想具有应用上的普遍性，且代码设计具有很高的可移植性。为达到性能要求，本文设计了自适应动态优化线程池，用于实现多线程程序设计。并对线程池中线程任务调度方式进行优化，以提高系统任务执行效率。详细设计了线程间同步处理，提出了死锁预防的优化与条件变量和互斥量联合使用进行线程池管理与临界资源的保护方案。设计系统链表，实现了应用系统中链表的统一实现与管理方案，降低了程序的代码量与程序复杂程度。为保证系统功能的完善性，实现了系统等待队列与任务超时等待处理线程。针对系统的稳定性，在设计中使用了linux操作系统中的管道信号机制与意外退出压栈函数的方式进行了意外中断机制处理设计。分析了TCP/IP传输原理，使用单包握手协议与海量数据流的方法解决了TCP/IP在传输过程中包粘连的问题，并保证了系统数据传输的速率。在系统安全性能上，使用了OpenSSL开源工具包提供的RSA加密算法对传输数据进行了加密处理。在用户信息安全性的设计上，采用了改进型的MD5密文算法进行用户数据信息的存储与验证，保证用户数据信息的安全性，并基于MD5算法进行了文件完整性验证的设计。针对用户文件权限，论文基于linux系统中的文件属性位进行了文件权限功能扩展性设计。通过以上的技术手段，针对性的进行了嵌入式设备无线文件系统的研究与设计，使系统较传统的多线程设计方式在访问效率上有了10-30%的提高。系统链表机制的设计，简化了系统约20%的代码量。系统意外中断处理机制使系统的稳定性得到了保证。基于RSA与改进型MD5码设计，保证了系统数据安全性，，并使用户信息的安全等级的到了很大的提升。系统应用性方面，较传统文件传输系统进行了功能性上的扩展，实现了等待队列，超时等待，文件权限管理等。
[Abstract]:In this paper, the multi-user mode file transfer system of special embedded wireless device is studied deeply, and the background file transfer system based on special wireless embedded device is improved and realized. It mainly carries on the embedded equipment operating system custom cut transplant, the driver loads, builds the wireless networking platform, and under the embedded equipment limited hardware resources condition, carries on the optimized improvement to the backstage software file transfer system mechanism. Some achievements have been made in improving the system stability, security, system program execution efficiency, and ensuring the application of the system. This research aims at the general embedded device, the design idea has the universality in the application, and the code design has the very high portability. In order to meet the performance requirements, an adaptive dynamic optimization thread pool is designed to implement multithread programming. The scheduling mode of thread task in thread pool is optimized to improve the efficiency of system task execution. The synchronization between threads is designed in detail, and the optimization of deadlock prevention and the combination of conditional variables and mutex are proposed for thread pool management and critical resource protection. The system linked list is designed to realize the unified implementation and management of the linked list in the application system and to reduce the code amount and the complexity of the program. In order to ensure the perfection of the system function, the system wait queue and the task timeout waiting thread are implemented. In view of the stability of the system, the pipeline signal mechanism in linux operating system and the unexpected exit from the stack function are used to deal with the unexpected interruption mechanism in the design. The principle of TCP/IP transmission is analyzed and the problem of packet adhesion in TCP/IP transmission process is solved by using the method of single packet handshake protocol and massive data stream and the data transmission rate of the system is guaranteed. In terms of system security, the RSA encryption algorithm provided by OpenSSL Open Source Toolkit is used to encrypt the transmitted data. In the design of user information security, the improved MD5 ciphertext algorithm is used to store and verify user data information to ensure the security of user data information, and the design of file integrity verification based on MD5 algorithm is presented. Aiming at the user file permission, this paper designs the extensibility of file permission function based on the file attribute bit in linux system. Through the above technical means, the research and design of wireless file system for embedded devices are carried out, which makes the system more efficient than the traditional multi-thread design method in the access efficiency of 10-30%. The design of the linked list simplifies about 20% of the system code. The stability of the system is guaranteed by the system unexpected interrupt handling mechanism. Based on RSA and improved MD5 code design, the system data security is guaranteed, and the security level of user information is greatly improved. Compared with the traditional file transfer system, the application of the system extends the function of waiting queue, timeout waiting, file permission management and so on.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP368.1;TN92

【参考文献】