Real-time Ethernet field bus data packet processing method based on original socket

Abstract

The invention relates to a real-time Ethernet field bus network data packet processing method based on PACKETMMAP, and relates to the technical field of numerical control, in particular to the technical field of real-time Ethernet field buses, and specifically relates to a real-time Ethernet field bus data packet processing method based on an original socket, and the original socket adopts a PACKETMMAP method. The method comprises the following steps: firstly, analyzing a transmission path of a real-time Ethernet fieldbus data packet from a network card driver to a kernel network protocol stack, and establishing a capture point of the real-time Ethernet fieldbus data packet at an entrance of the kernel network protocol stack; then, analyzing the characteristics of the data packet at the capture point, and establishing a data packet capture and forwarding method based on PACKETMMAP; and finally, according to the bus protocol type to which the data packet belongs, designing an analysis processing method of the data packet in the real-time Ethernet bus component in the user space.

Description

technical field [0001] The invention relates to the technical field of numerical control, in particular to the field of real-time Ethernet field bus technology, and in particular to a method for processing data packets of the real-time Ethernet field bus based on raw sockets. The raw sockets adopt the PACKET_MMAP method. Background technique [0002] The PACKET_MMAP mechanism is a socket programming interface based on memory mapping provided by the kernel. This mechanism allocates a kernel buffer area in the kernel space and maps it to the user space, and then the application program in the user space obtains the mapping to the user through the mmap system call. Spatial data. The PACKET_MMAP mechanism is very efficient, it provides a configurable size ring buffer mapped to user space. In this way, the buffer shared by the kernel space and the user space can also reduce data copying. [0003] Middle and low-end CNC systems have high requirements for real-time performance, b...

Images