swconfig allows you to configure configurable Ethernet network switches.
It is considered legacy and new switch drivers should use the DSA (distributed switch architecture) kernel framework which makes it possible to use standard userspace tools such as
ip to configure the switches.
Make sure you can safemode or TTL before changing network/switch settings
swconfig supports the following hardware switches using the mentioned
|Driver||Ethernet switches models||Hardware wiring|
|adm6996||Infineon/ADMTek 6996M/L/FC||MDIO / GPIO|
|b53||Broadcom BCM5325/5365/5395/5398/53115/53125/53128/53010/53011/53012/53018/53019/63xx||MDIO / SPI / MMIO|
|ip17xx||IC+ IP178C IP175A/C/D||MDIO|
|rtl8366s||Realtek RTL8366S||MDIO GPIO/SMI|
|rtl8366rb||Realtek RTL8366RB||MDIO GPIO/SMI|
swconfig dev switch0 show
swconfig dev rtl8366rb show
and you will obtain:
VLAN 1: info: VLAN 1: Ports: '12345t', members=003e, untag=001e, fid=0 fid: 0 ports: 1 2 3 4 5t VLAN 2: info: VLAN 2: Ports: '05t', members=0021, untag=0001, fid=0 fid: 0 ports: 0 5t
swconfig dev rt305x help switch0: rt305x(rt305x-esw), ports: 7 (cpu @ 6), vlans: 4096 --switch Attribute 1 (int): enable_vlan (VLAN mode (1:enabled)) Attribute 2 (int): alternate_vlan_disable (Use en_vlan instead of doubletag to disable VLAN mode) Attribute 3 (none): apply (Activate changes in the hardware) Attribute 4 (none): reset (Reset the switch) --vlan Attribute 1 (ports): ports (VLAN port mapping) --port Attribute 1 (int): disable (Port state (1:disabled)) Attribute 2 (int): doubletag (Double tagging for incoming vlan packets (1:enabled)) Attribute 3 (int): untag (Untag (1:strip outgoing vlan tag)) Attribute 4 (int): led (LED mode (0:link, 1:100m, 2:duplex, 3:activity, 4:collision, 5:linkact, 6:duplcoll, 7:10mact, 8:1) Attribute 5 (int): lan (HW port group (0:wan, 1:lan)) Attribute 6 (int): recv_bad (Receive bad packet counter) Attribute 7 (int): recv_good (Receive good packet counter) Attribute 8 (int): pvid (Primary VLAN ID) Attribute 9 (string): link (Get port link information)
swconfig dev rtl8366rb help switch1: rtl8366rb(RTL8366RB), ports: 6 (cpu @ 5), vlans: 4096 --switch Attribute 1 (int): enable_learning (Enable learning, enable aging) Attribute 2 (int): enable_vlan (Enable VLAN mode) Attribute 3 (int): enable_vlan4k (Enable VLAN 4K mode) Attribute 4 (none): reset_mibs (Reset all MIB counters) Attribute 5 (int): blinkrate (Get/Set LED blinking rate (0 = 43ms, 1 = 84ms, 2 = 120ms, 3 = 170ms, 4 = 340ms, 5 = 670ms)) Attribute 6 (int): enable_qos (Enable QOS) Attribute 7 (none): apply (Activate changes in the hardware) Attribute 8 (none): reset (Reset the switch) --vlan Attribute 1 (string): info (Get vlan information) Attribute 2 (int): fid (Get/Set vlan FID) Attribute 3 (ports): ports (VLAN port mapping) --port Attribute 1 (none): reset_mib (Reset single port MIB counters) Attribute 2 (string): mib (Get MIB counters for port) Attribute 3 (int): led (Get/Set port group (0 - 3) led mode (0 - 15)) Attribute 4 (int): disable (Get/Set port state (enabled or disabled)) Attribute 5 (int): rate_in (Get/Set port ingress (incoming) bandwidth limit in kbps) Attribute 6 (int): rate_out (Get/Set port egress (outgoing) bandwidth limit in kbps) Attribute 7 (int): pvid (Primary VLAN ID) Attribute 8 (string): link (Get port link information)
disable: ssh > swconfig dev switch0 port 4 set disable 1 enable: ssh > swconfig dev switch0 port 4 set disable 0
Note: Make sure to apply any changes made previously with the “set” command.
swconfig dev rtl8366s port 0 set led 2 swconfig dev rtl8366rb set apply
swconfig dev switch0 set enable_vlan 0 swconfig dev switch0 set apply
Generic Netlink Switch configuration API
The following documentation covers the Linux Ethernet switch configuration API which is based on the Generic Netlink infrastructure.
Most Ethernet switches found in small routers are managed switches which allow the following operations:
Such switches can be connected to the controlling CPU using different hardware busses, but most commonly:
As of today the usual way to configure such a switch was either to write a specific driver or to write an user-space application which would have to know about the hardware differences and figure out a way to access the switch registers (spidev, SIOCIGGMIIREG, mmap…) from user-space.
This has multiple issues:
The goal of the switch configuration API is to provide a common basis to build re-usable and extensible switch drivers with the following ideas in mind:
Based on these design goals the Generic Netlink kernel/user-space communication mechanism was chosen because it allows for all design goals to be met.
The Marvell Distributed Switch Architecture (DSA) drivers is an existing solution which is a heavy switch driver infrastructure, is Marvell-centric, only supports MDIO connected switches, mangles an Ethernet driver transmit/receive paths and does not offer a central control path for the user.
swconfig is vendor agnostic, does not mangle the transmit/receive path of an Ethernet driver and is focused on the control path of the switch rather that the data path. It is based on Generic Netlink to allow for each switch driver to easily extend the swconfig API without causing major core parts rework each and every time someone has a specific feature to implement and offers a central configuration point with a well-defined API.
* More info e.g. at LWN.net 2017-04-19: The rise of Linux-based networking hardware:
“The Linux kernel manipulates switches with three different operation structures:
netdev_ops. Certain switches, however, also need distributed switch architecture (DSA).
DSA's development was parallel to swconfig, written by the OpenWrt project. The main difference between swconfig and DSA is that DSA-supported switches show one network interface per port, whereas swconfig-configured switches show up as a single port, which limits the amount of information that can be extracted from the switch. For example, you cannot have per-port traffic statistics with swconfig. That limitation is what led to the creation of the switchdev framework, when swconfig was proposed (then refused) for inclusion in mainline. Another goal of switchdev was to support bridge hardware offloading and network interface card (NIC) virtualization…”
The main data structure of the switch configuration API is a “struct switch_dev” which contains the following members:
A particular switch device is registered/unregistered using the following pair of functions:
register_switch(struct switch_dev *sw_dev, struct net_device *dev); unregister_switch(struct switch_dev);
A given switch driver can be backed by any kind of underlying bus driver (i2c client, GPIO driver, MMIO driver, directly into the Ethernet MAC driver…).
The set of common operations to all switches is represented by the “struct switch_dev_ops” function pointers, these common operations are defined as such:
The switch_dev_ops structure also contains an extensible way of representing and querying switch specific features, 3 different types of attributes are available:
Each of these 3 categories must be represented using an array of “struct switch_attr” attributes. This structure must be filed with:
The “struct switch_attr” directly maps to a Generic Netlink type of command and will be automatically discovered by the “swconfig” user-space utility without requiring user-space changes.