Linux Network card driver programming (1)

One. Network Card driver Architecture analysis

1. Linux Network Subsystem

#系统调用接口层

Provides a unified way for applications to access the network subsystem.

#协议无关层

Provides a common way to use the Transport layer protocol.

#协议栈的实现

Implementing a specific network protocol

#设备无关层

Common interface for protocol and device-driven communication

#设备驱动程序

2. Important Data structures

2.1 Network card description structure

In the Linux kernel, each NIC is described by a "net_device" structure, and some of the key members are:

#char Name[ifnamsiz]

Device name, such as: eth%d

#unsigned Long Base_addr

I/O base Address

#const struct Net_device_ops *netdev_ops;

2.2 Network card Operation Collection

Description: Similar to the file_operations structure in character device drivers, the NET_DEVICE_OPS structure records the operations supported by the NIC.

static const struct Net_device_ops Dm9000_netdev_ops =

{

. ndo_open= Dm9000_open,

. ndo_stop= Dm9000_stop,

. ndo_start_xmit= Dm9000_start_xmit,

. ndo_do_ioctl= Dm9000_ioctl,

. ndo_validate_addr= Eth_validate_addr,

. ndo_set_mac_address= Eth_mac_addr,

};

2.3 Network Packets

Each network packet in the Linux kernel is described by a socket buffer struct struct sk_buff,

That is, a SK_BUFF structure is a network packet, and pointers to Sk_buff are often called SKB.

3. Network Card driver Architecture analysis

1. cs8900.c

　　　　　

Linux Network card driver programming (1)