Wi-Fi: Difference between revisions

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This document describes how to set up a wireless network connection with WPA encryption.
Alpine Linux supports both wireless daemons i.e [[#wpa_supplicant|wpa_supplicant]] and [[iwd]]. This page describes how to set up a wireless network connection with WPA encryption using [[#wpa_supplicant|wpa_supplicant]] and provides the troubleshooting steps to configure wireless interface/drivers.
{{Note|Using both wireless daemons i.e [[#wpa_supplicant|wpa_supplicant]] and [[iwd]] simultaneously lead to conflicts.}}


== Install necessary drivers and software  ==
== Prerequisites ==


First make sure your wireless drivers are loaded properly. (if you are using a '''Broadcom chipset''', see the [[#Broadcom_Wi-Fi_Chipset_Users|section at the bottom of this post]].)
Working wireless drivers. In most cases installing {{Pkg|linux-firmware}} should get you the required drivers. Installation of this package can produce errors on diskless or data disk modes. If such errors occur, switch to system disk mode.
To list your available network interfaces: {{Cmd|ip link}}
or {{Cmd|ip a}}


Install {{Pkg|wireless-tools}} and {{Pkg|wpa_supplicant}}.
Refer to [[#Troubleshooting|Troubleshooting]] section to see if you don't see any wireless interfaces (e.g. {{Path|wlan0}}). You probably need to load and/or install drivers/firmware. If you are using a '''Broadcom chipset''', see the [[#Broadcom_Wi-Fi_Chipset_Users|Broadcom Wi-Fi section]].
{{Cmd|apk add wireless-tools wpa_supplicant}}


== Manual Configuration  ==
Bring up the desired interface: {{Cmd|# ip link set wlan0 up}}


List your available network interfaces. If you don't see any wireless interfaces (e.g. {{Path|wlan0}}), you probably need to load and/or install extra drivers/firmware.
== wpa_supplicant  ==
{{Cmd|ip link}}
{{Seealso|iwd}}


Bring the desired interface up.
Networking [[Configure_Networking#Network_setup-scripts|setup-scripts]] can configure your wifi quickly using <code>wpa_supplicant</code> which can be used with [[NetworkManager]], the standard Linux network configuration tool suite.  If the above does not meet your requirement, please follow the steps outlined on this page for manual configuration.
{{Cmd|ip link set wlan0 up}}


{{Note|If this errors with <code>ioctl 0x8914 failed: No error information</code>, that's <code>busybox ip</code>'s way of saying your wireless radio is rfkill'd. See [https://wiki.archlinux.org/index.php/Wireless_network_configuration#Rfkill_caveat here] for information on how to unblock your wireless radio; the base installation should have <code>busybox rfkill</code> available.}}
To get started install {{Pkg|wpa_supplicant}} package: {{Cmd|# apk add wpa_supplicant}}


Use this command to add your Wi-Fi network to wpa_supplicant: {{Cmd|# wpa_passphrase 'ExampleWifiSSID' 'ExampleWifiPassword' > /etc/wpa_supplicant/wpa_supplicant.conf}}
''(Access point not broadcasting its SSID requires additional line <code>scan_ssid=1</code> in the file {{Path|/etc/wpa_supplicant/wpa_supplicant.conf}})''


Use the interface to scan for wireless access points. Make sure the ESSID you want to connect to appears here.
{{Note|the Wi-Fi SSID and password are case sensitive and the single quote before and after the SSID and password need to be there}}
{{Cmd|iwlist wlan0 scanning}}


Associate the interface with desired ESSID.
Start wpa_supplicant in the foreground to check if wireless connection succeeds.{{Cmd|# wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf}}
{{Cmd|iwconfig wlan0 essid ExampleWifi}}


Sanity check: the interface should be configured with {{Path|ESSID:"ExampleWifi"}}.
'''Optional security precaution:'''
{{Cmd|iwconfig wlan0}}


Create a wpa_supplicant configuration stanza for the wireless access point.
By default {{Pkg|wpa_supplicant}} will store your Wi-Fi password in plain text:{{Cat|/etc/wpa_supplicant/wpa_supplicant.conf|<nowiki>network={
{{Cmd|wpa_passphrase 'ExampleWifi' 'ExampleWifiPassword' > /etc/wpa_supplicant/wpa_supplicant.conf}}
    ssid="<YourSSIDShouldBeHere>"
''(Access point not broadcasting its SSID requires additional line <code>scan_ssid=1</code> in the file <code>wpa_supplicant.conf</code>)''
        #psk="<YourPasswordShouldBeHereInPlainText>"
    psk=<RandomLettersAndNumbersShouldBeHere>
}</nowiki>}}
If you dont want your stored password in plain text just delete the line with <code>#psk="<YourPasswordShouldBeHereInPlainText>"</code> on it.


If all is well, run it as a daemon in the background by setting the {{Path|-B}} option. {{Cmd|# wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf}}


Start wpa_supplicant in the foreground to make sure the connection succeeds.
Configure the interface with an IP address.{{Cmd|# udhcpc -i wlan0}}
{{Cmd|wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf}}


If all is well, run it as a daemon in the background by setting the {{Path|-B}} option.
Sanity check: the interface should have a {{Path|inet}} address. {{Cmd|$ ip addr show wlan0}}
{{Cmd|wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf}}


Configure the interface with an IP address.
Add a entry for the desired interface (e.g. <code>wlan0</code>) in the file as follows:{{Cat|/etc/network/interfaces|auto lo
{{Cmd|udhcpc -i wlan0}}
auto wlan0
iface wlan0 inet dhcp}}
 
{{Warning|Don't remove or comment out the '''auto lo''' entry}}
 
Sanity check: Make sure {{Path|/etc/wpa_supplicant/wpa_supplicant.conf}} is the correct configuration for the wireless access point you want to connect to.
 
Bring the interface down. {{Cmd|# ip link set wlan0 down}}


Sanity check: the interface should have an {{Path|inet}} address.
Manually restart (or '''start''') '''networking'''.{{Cmd|# rc-service networking --quiet restart &}}
{{Cmd|ip addr show wlan0}}


== Automatic Configuration on System Boot  ==
Perform [[Configure_Networking#Connectivity_testing|sanity checks]]. For issues related to name resolution, refer [[Configure_Networking#Configuring_DNS|Networking]] section.


Add a stanza for the desired interface (e.g. {{Path|wlan0}}) to {{Path|/etc/network/interfaces}}:
=== Service configuration ===


<pre>
Proceed to configure wpa_supplicant service to start automatically on boot, if networking works properly: {{Cmd|# rc-update add wpa_supplicant boot}}
auto wlan0
Also ensure that '''networking''' is set to automatically start on boot: {{Cmd|# rc-update add networking boot}}
iface wlan0 inet dhcp
 
</pre>
Manage wpa_supplicant service using the standard '''start''', '''stop''' and '''restart''' options. For eg: to start wpa_supplicant service: {{Cmd|# rc-service wpa_supplicant start}}
 
=== Launching udhcpc through wpa_cli actions ===


Make sure {{Path|/etc/wpa_supplicant/wpa_supplicant.conf}} is the correct configuration for the wireless access point you want to connect to.
With the above configuration, udhcpc will only run once at boot. If the Wifi isn't available then, or the network changes after booting, udhcpc needs to be notified. You can automatically notify udhcpc of network changes by using a wpa_cli action file, such as the one installed by default at {{Path|/etc/wpa_supplicant/wpa_cli.sh}}.


Bring the interface down.
To manually start a wpa_cli daemon with an action file, use the `-a` option: {{Cmd|# wpa_cli -a /etc/wpa_supplicant/wpa_cli.sh}}


{{Cmd|ifconfig wlan0 down}}
To do this automatically, use the `wpa_cli` service included in {{Pkg|wpa_supplicant-openrc}}: {{Cat|/etc/conf.d/wpa_cli|<nowiki>WPACLI_OPTS="-a /etc/wpa_supplicant/wpa_cli.sh"</nowiki>}}
Add the service to start at boot: {{Cmd|# rc-update add wpa_cli boot}}


Manually start wpa_supplicant.
== Troubleshooting ==


{{Cmd|/etc/init.d/wpa_supplicant start}}
=== Check dmesg ===


If all is well (confirm with the sanity checks in [[#Manual_Configuration|Manual Configuration]]), configure wpa_supplicant to start automatically on boot.
Run dmesg and check for errors related to the wireless interface. Usually, dmesg gives maximum information related to network and all other hardware.
{{Cmd|# dmesg}}


{{Cmd|rc-update add wpa_supplicant boot}}
=== checking network cards ===


{{Cmd|$ cat /proc/net/dev }} lists the network interfaces that are detected. If the expected interfaces are not available, Check what network hardware chip you have using lspci or lsusb:


=== Launching udhcpc through wpa_cli actions ===
{{Cmd|$ lspci -nn }}
{{Cmd|$ lsusb }}


With the above configuration, udhcpc will only run once at boot.
Refer [[How to get regular stuff working#Hardware_Management|hardware management]], if the default outputs shown above lacks sufficient information.
If the Wifi isn't available then, or the network changes in between, it needs to be notified.
This is done through the wpa_cli action script in /etc/wpa_supplicant/wpa_cli.sh


{{Cmd|rc-update add wpa_cli boot}}
Check what driver the card uses and modprobe it. Check that the card is in master mode.
Check what driver you need on the [https://wireless.wiki.kernel.org/en/users/Drivers/b43#list_of_hardware b43 compatibility page]


== Broadcom Wi-Fi Chipset Users  ==
=== Broadcom Wi-Fi Chipset Users  ===


The Broadcom chipset is quite popular among older computers. You will need to compile the firmware manually for this chipset as it is not included.  
The Broadcom chipset is quite popular among older computers. The b43 driver is included in the linux-lts or linux-edge kernel packages. However, you might need to compile the firmware manually for this chipset as it is not included in linux-firmware for some cards.  


You can check if you have a Broadcom chipset by using dmesg:
To check what broadcom chip you have using lspci:


{{Cmd|dmesg {{!}} grep Broadcom}}
{{Cmd|$ lspci -nn -d 14e4:}}


First install the SDK an Git:
====B43====
{{Cmd|apk add alpine-sdk git}}


Then git clone aports from git.alpinelinux.org.
Download firmware cutter. {{Cmd|$ apk add b43-fwcutter}}


Now we have everything to download the proprietary driver and extract the firmware from it: {{Cmd|<nowiki># export FIRMWARE_INSTALL_DIR="/lib/firmware"
$ wget http://www.lwfinger.com/b43-firmware/broadcom-wl-5.100.138.tar.bz2
$ tar xjf broadcom-wl-5.100.138.tar.bz2
$ b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" broadcom-wl-5.100.138/linux/wl_apsta.o</nowiki>}}


{{Cmd|git clone git://git.alpinelinux.org/aports}}
More information can be found [http://linuxwireless.sipsolutions.net/en/users/Drivers/b43/#Other_distributions_not_mentioned_above here].


Change your directory to '''aports/non-free/b43-firmware''', then build it.
Now you need to use modprobe so the device will show up: {{Cmd|# modprobe b43}}


{{Tip|You can't be root and must be a user of the group abuild (use groupadd f.e. '''addgroup $(whoami) abuild''')}}
Now continue with the normal instructions.  
{{Tip|If this is your first time building a package you will need to generate a key for use in signing packages (use '''abuild-keygen -a -i''')}}


{{Cmd|abuild -r}}
====wl====


Install the generated packge file (it will be in ~/packages/) - make sure to pass '''--allow-untrusted'''
First install the software we need to build a driver[https://unix.stackexchange.com/questions/606073/how-to-build-kernel-modules-in-alpine-3-12 ^]: {{Cmd|apk add git alpine-sdk linux-headers}}


{{Cmd|apk add --allow-untrusted ~/packages/...pkg}}
Then install the driver build repo (this is archived, however it's legacy so that doesn't matter): {{Cmd|git clone https://github.com/antoineco/broadcom-wl
cd broadcom-wl
}}


Now we need fwcutter, which is executed from the firmware package:
Then follow the build instructions listed in the git repo: {{Cmd|make
doas make install
doas depmod -A
doas modprobe wl
}}


{{Cmd|apk add b43-fwcutter b43-firmware}}
Reboot and you have a working wl driver. Now continue with the normal instructions.


Now you need to use modprobe so the device will show up:
=== Rfkill ===


{{Cmd|modprobe b43}}
An error message <code>ioctl 0x8914 failed: No error information</code>, is the <code>busybox ip</code>'s way of saying your wireless radio is rfkilled, which means the wireless card is blocked by kernel. This can be changed using rfkill. To show the current status of your Wi-Fi:
<p style="background-color:#f9f9f9; border:1px dashed #2f6fab; line-height:1.1em; padding:1em; font-family:monospace; font-size:10pt; white-space:pre; overflow:auto;"><span style="color:green;">~</span>'''$''' rfkill list
0: phy0: wlan
    Soft blocked: no
    Hard blocked: no
</p>


To automate this on startup add it to /etc/modules:
If the card is hard-blocked, use the hardware button or switch to unblock it. If the card is not hard-blocked but soft-blocked, use the following command: {{Cmd|# rfkill unblock wifi}}


{{Cmd|echo b43 >> /etc/modules}}
== See Also ==


Now continue with the normal instructions.  
* [[Configure_Networking| Networking in Alpine Linux]]
* [[Iwd|iwd]] - An alternate to wpa_supplicant
* [[NetworkManager]] - Front-end to Networking
* [https://wiki.postmarketos.org/wiki/WiFi PostmarketOS Wiki]
* [https://wiki.archlinux.org/title/Network_configuration/Wireless Archwiki]
* [https://wiki.gentoo.org/wiki/Wi-Fi Gentoo Wiki]


[[Category:Networking]]
[[Category:Networking]]

Revision as of 15:06, 10 January 2025

Alpine Linux supports both wireless daemons i.e wpa_supplicant and iwd. This page describes how to set up a wireless network connection with WPA encryption using wpa_supplicant and provides the troubleshooting steps to configure wireless interface/drivers.

Note: Using both wireless daemons i.e wpa_supplicant and iwd simultaneously lead to conflicts.

Prerequisites

Working wireless drivers. In most cases installing linux-firmware should get you the required drivers. Installation of this package can produce errors on diskless or data disk modes. If such errors occur, switch to system disk mode.

To list your available network interfaces:

ip link

or

ip a

Refer to Troubleshooting section to see if you don't see any wireless interfaces (e.g. wlan0). You probably need to load and/or install drivers/firmware. If you are using a Broadcom chipset, see the Broadcom Wi-Fi section.

Bring up the desired interface:

# ip link set wlan0 up

wpa_supplicant

Networking setup-scripts can configure your wifi quickly using wpa_supplicant which can be used with NetworkManager, the standard Linux network configuration tool suite. If the above does not meet your requirement, please follow the steps outlined on this page for manual configuration.

To get started install wpa_supplicant package:

# apk add wpa_supplicant

Use this command to add your Wi-Fi network to wpa_supplicant:

# wpa_passphrase 'ExampleWifiSSID' 'ExampleWifiPassword' > /etc/wpa_supplicant/wpa_supplicant.conf

(Access point not broadcasting its SSID requires additional line scan_ssid=1 in the file /etc/wpa_supplicant/wpa_supplicant.conf)

Note: the Wi-Fi SSID and password are case sensitive and the single quote before and after the SSID and password need to be there

Start wpa_supplicant in the foreground to check if wireless connection succeeds.

# wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

Optional security precaution:

By default wpa_supplicant will store your Wi-Fi password in plain text:

Contents of /etc/wpa_supplicant/wpa_supplicant.conf

network={ ssid="<YourSSIDShouldBeHere>" #psk="<YourPasswordShouldBeHereInPlainText>" psk=<RandomLettersAndNumbersShouldBeHere> }

If you dont want your stored password in plain text just delete the line with #psk="<YourPasswordShouldBeHereInPlainText>" on it.

If all is well, run it as a daemon in the background by setting the -B option.

# wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

Configure the interface with an IP address.

# udhcpc -i wlan0

Sanity check: the interface should have a inet address.

$ ip addr show wlan0

Add a entry for the desired interface (e.g. wlan0) in the file as follows:

Contents of /etc/network/interfaces

auto lo auto wlan0 iface wlan0 inet dhcp
Warning: Don't remove or comment out the auto lo entry


Sanity check: Make sure /etc/wpa_supplicant/wpa_supplicant.conf is the correct configuration for the wireless access point you want to connect to.

Bring the interface down.

# ip link set wlan0 down

Manually restart (or start) networking.

# rc-service networking --quiet restart &

Perform sanity checks. For issues related to name resolution, refer Networking section.

Service configuration

Proceed to configure wpa_supplicant service to start automatically on boot, if networking works properly:

# rc-update add wpa_supplicant boot

Also ensure that networking is set to automatically start on boot:

# rc-update add networking boot

Manage wpa_supplicant service using the standard start, stop and restart options. For eg: to start wpa_supplicant service:

# rc-service wpa_supplicant start

Launching udhcpc through wpa_cli actions

With the above configuration, udhcpc will only run once at boot. If the Wifi isn't available then, or the network changes after booting, udhcpc needs to be notified. You can automatically notify udhcpc of network changes by using a wpa_cli action file, such as the one installed by default at /etc/wpa_supplicant/wpa_cli.sh.

To manually start a wpa_cli daemon with an action file, use the `-a` option:

# wpa_cli -a /etc/wpa_supplicant/wpa_cli.sh

To do this automatically, use the `wpa_cli` service included in wpa_supplicant-openrc:

Contents of /etc/conf.d/wpa_cli

WPACLI_OPTS="-a /etc/wpa_supplicant/wpa_cli.sh"

Add the service to start at boot:

# rc-update add wpa_cli boot

Troubleshooting

Check dmesg

Run dmesg and check for errors related to the wireless interface. Usually, dmesg gives maximum information related to network and all other hardware.

# dmesg

checking network cards

$ cat /proc/net/dev

lists the network interfaces that are detected. If the expected interfaces are not available, Check what network hardware chip you have using lspci or lsusb:

$ lspci -nn

$ lsusb

Refer hardware management, if the default outputs shown above lacks sufficient information.

Check what driver the card uses and modprobe it. Check that the card is in master mode. Check what driver you need on the b43 compatibility page

Broadcom Wi-Fi Chipset Users

The Broadcom chipset is quite popular among older computers. The b43 driver is included in the linux-lts or linux-edge kernel packages. However, you might need to compile the firmware manually for this chipset as it is not included in linux-firmware for some cards.

To check what broadcom chip you have using lspci:

$ lspci -nn -d 14e4:

B43

Download firmware cutter.

$ apk add b43-fwcutter

Now we have everything to download the proprietary driver and extract the firmware from it:

# export FIRMWARE_INSTALL_DIR="/lib/firmware" $ wget http://www.lwfinger.com/b43-firmware/broadcom-wl-5.100.138.tar.bz2 $ tar xjf broadcom-wl-5.100.138.tar.bz2 $ b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" broadcom-wl-5.100.138/linux/wl_apsta.o

More information can be found here.

Now you need to use modprobe so the device will show up:

# modprobe b43

Now continue with the normal instructions.

wl

First install the software we need to build a driver^:

apk add git alpine-sdk linux-headers

Then install the driver build repo (this is archived, however it's legacy so that doesn't matter):

git clone https://github.com/antoineco/broadcom-wl cd broadcom-wl

Then follow the build instructions listed in the git repo:

make doas make install doas depmod -A doas modprobe wl

Reboot and you have a working wl driver. Now continue with the normal instructions.

Rfkill

An error message ioctl 0x8914 failed: No error information, is the busybox ip's way of saying your wireless radio is rfkilled, which means the wireless card is blocked by kernel. This can be changed using rfkill. To show the current status of your Wi-Fi:

~$ rfkill list 0: phy0: wlan Soft blocked: no Hard blocked: no

If the card is hard-blocked, use the hardware button or switch to unblock it. If the card is not hard-blocked but soft-blocked, use the following command:

# rfkill unblock wifi

See Also