目录

​​一、问题描述​​

​​二、问题处理​​

​​udevadm info -a -p /sys/class/net/FE0​​

​​udevadm info -a -p /sys/class/net/FE1​​

一、问题描述

        本人使用两张以太网卡，分别为emac、gmac，insmod加载两张网卡驱动后，一张为FE0，一张为eth0，与我的初衷需要生成的FE0、FE1不符合，出现问题的udev配置文件如下

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="FE0"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="FE1"

通过udevadm monitor命令监控发现，其实以上两条规则匹配的内容是一致的，导致无法生产FE0、FE1，所以需要增加一条匹配键来区分这两个网卡设备。

二、问题处理

首先我们需要找到这两个设备的差异项，通过udevadm info命令

udevadm info -a -p /sys/class/net/FE0

clou@SMIOS:/etc/udev/rules.d# udevadm info -a -p /sys/class/net/FE0

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/soc/emac0/net/FE0':
    KERNEL=="FE0"
    SUBSYSTEM=="net"
    DRIVER==""
    ATTR{addr_assign_type}=="3"
    ATTR{addr_len}=="6"
    ATTR{address}=="7a:56:90:5b:2f:4f"
    ATTR{broadcast}=="ff:ff:ff:ff:ff:ff"
    ATTR{carrier}=="1"
    ATTR{dev_id}=="0x0"
    ATTR{dormant}=="0"
    ATTR{duplex}=="full"
    ATTR{flags}=="0x1003"
    ATTR{ifalias}==""
    ATTR{ifindex}=="19"
    ATTR{iflink}=="19"
    ATTR{link_mode}=="0"
    ATTR{mtu}=="1500"
    ATTR{netdev_group}=="0"
    ATTR{operstate}=="up"
    ATTR{power/async}=="disabled"
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_kids}=="0"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_enabled}=="disabled"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"
    ATTR{power/runtime_usage}=="0"
    ATTR{queues/rx-0/rps_cpus}=="0"
    ATTR{queues/rx-0/rps_flow_cnt}=="0"
    ATTR{queues/tx-0/byte_queue_limits/hold_time}=="1000"
    ATTR{queues/tx-0/byte_queue_limits/inflight}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit_max}=="1879048192"
    ATTR{queues/tx-0/byte_queue_limits/limit_min}=="0"
    ATTR{queues/tx-0/tx_timeout}=="0"
    ATTR{queues/tx-0/xps_cpus}=="0"
    ATTR{speed}=="100"
    ATTR{statistics/collisions}=="0"
    ATTR{statistics/multicast}=="0"
    ATTR{statistics/rx_bytes}=="217282"
    ATTR{statistics/rx_compressed}=="0"
    ATTR{statistics/rx_crc_errors}=="0"
    ATTR{statistics/rx_dropped}=="7"
    ATTR{statistics/rx_errors}=="0"
    ATTR{statistics/rx_fifo_errors}=="0"
    ATTR{statistics/rx_frame_errors}=="0"
    ATTR{statistics/rx_length_errors}=="0"
    ATTR{statistics/rx_missed_errors}=="0"
    ATTR{statistics/rx_over_errors}=="0"
    ATTR{statistics/rx_packets}=="1981"
    ATTR{statistics/tx_aborted_errors}=="0"
    ATTR{statistics/tx_bytes}=="46857"
    ATTR{statistics/tx_carrier_errors}=="0"
    ATTR{statistics/tx_compressed}=="0"
    ATTR{statistics/tx_dropped}=="0"
    ATTR{statistics/tx_errors}=="0"
    ATTR{statistics/tx_fifo_errors}=="0"
    ATTR{statistics/tx_heartbeat_errors}=="0"
    ATTR{statistics/tx_packets}=="328"
    ATTR{statistics/tx_window_errors}=="0"
    ATTR{tx_queue_len}=="1000"
    ATTR{type}=="1"

  looking at parent device '/devices/soc/emac0':
    KERNELS=="emac0"
    SUBSYSTEMS=="platform"
    DRIVERS=="sun4i-emac"
    ATTRS{power/async}=="disabled"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_kids}=="0"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_enabled}=="disabled"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{power/runtime_usage}=="0"

  looking at parent device '/devices/soc':
    KERNELS=="soc"
    SUBSYSTEMS=="platform"
    DRIVERS==""
    ATTRS{power/async}=="disabled"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_kids}=="0"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_enabled}=="disabled"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{power/runtime_usage}=="0"

注意其中的匹配键：KERNELS=="emac0"

udevadm info -a -p /sys/class/net/FE1

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/soc/gmac0/net/FE1':
    KERNEL=="FE1"
    SUBSYSTEM=="net"
    DRIVER==""
    ATTR{addr_assign_type}=="0"
    ATTR{addr_len}=="6"
    ATTR{address}=="36:c9:e3:f1:b8:05"
    ATTR{broadcast}=="ff:ff:ff:ff:ff:ff"
    ATTR{dev_id}=="0x0"
    ATTR{flags}=="0x1002"
    ATTR{ifalias}==""
    ATTR{ifindex}=="32"
    ATTR{iflink}=="32"
    ATTR{link_mode}=="0"
    ATTR{mtu}=="1500"
    ATTR{netdev_group}=="0"
    ATTR{operstate}=="down"
    ATTR{power/async}=="disabled"
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_kids}=="0"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_enabled}=="disabled"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"
    ATTR{power/runtime_usage}=="0"
    ATTR{queues/rx-0/rps_cpus}=="0"
    ATTR{queues/rx-0/rps_flow_cnt}=="0"
    ATTR{queues/tx-0/byte_queue_limits/hold_time}=="1000"
    ATTR{queues/tx-0/byte_queue_limits/inflight}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit_max}=="1879048192"
    ATTR{queues/tx-0/byte_queue_limits/limit_min}=="0"
    ATTR{queues/tx-0/tx_timeout}=="0"
    ATTR{queues/tx-0/xps_cpus}=="0"
    ATTR{statistics/collisions}=="0"
    ATTR{statistics/multicast}=="0"
    ATTR{statistics/rx_bytes}=="0"
    ATTR{statistics/rx_compressed}=="0"
    ATTR{statistics/rx_crc_errors}=="0"
    ATTR{statistics/rx_dropped}=="0"
    ATTR{statistics/rx_errors}=="0"
    ATTR{statistics/rx_fifo_errors}=="0"
    ATTR{statistics/rx_frame_errors}=="0"
    ATTR{statistics/rx_length_errors}=="0"
    ATTR{statistics/rx_missed_errors}=="0"
    ATTR{statistics/rx_over_errors}=="0"
    ATTR{statistics/rx_packets}=="0"
    ATTR{statistics/tx_aborted_errors}=="0"
    ATTR{statistics/tx_bytes}=="0"
    ATTR{statistics/tx_carrier_errors}=="0"
    ATTR{statistics/tx_compressed}=="0"
    ATTR{statistics/tx_dropped}=="0"
    ATTR{statistics/tx_errors}=="0"
    ATTR{statistics/tx_fifo_errors}=="0"
    ATTR{statistics/tx_heartbeat_errors}=="0"
    ATTR{statistics/tx_packets}=="0"
    ATTR{statistics/tx_window_errors}=="0"
    ATTR{tx_queue_len}=="1000"
    ATTR{type}=="1"

  looking at parent device '/devices/soc/gmac0':
    KERNELS=="gmac0"
    SUBSYSTEMS=="platform"
    DRIVERS=="sunxi-gmac"
    ATTRS{power/async}=="enabled"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_kids}=="0"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_enabled}=="disabled"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{power/runtime_usage}=="0"

  looking at parent device '/devices/soc':
    KERNELS=="soc"
    SUBSYSTEMS=="platform"
    DRIVERS==""
    ATTRS{power/async}=="disabled"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_kids}=="0"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_enabled}=="disabled"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{power/runtime_usage}=="0"

注意其中的匹配键：KERNELS=="gmac0"

所以，分别把以上两条键值添加到规则表中

KERNELS=="emac0", SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="FE0"
KERNELS=="gmac0", SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="FE1"

常用匹配键：
    * KERNEL     - 匹配设备在内核中的命名
    * SUBSYSTEM  - 匹配设备(在sysfs中)的subsystem名
    * DRIVER     - 匹配设备对应的驱动名
    * ATTR       - 匹配设备在sysfs中属性
    * KERNELS    - 匹配设备及其父亲在内核中的命名
    * SUBSYSTEMS - 匹配设备及其父亲(在sysfs中)的subsystem名
    * DRIVERS    - 匹配设备及其父亲对应的驱动名
    * ATTRS      - 匹配设备及其父亲在sysfs中属性
      注：父亲表示直到最上层的所有祖先

至此，两张相同的网卡emac、gmac同时加载，通过udev规则实现了匹配。

udev匹配两张网卡_linux

 

三、其它

/usr/lib/udev/rules.d/70-persistent-net.rules 和 /etc/udev/udev.d/70-persistent-net.rules的区别，前者为系统，后者为用户添加规则，用户添加的规则比系统的优先级要高。