Dev1 Galaxy Forum / [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Tue, 12 Mar 2024 19:23:18 +0000

Just a quick follow-up regarding haveged.

TL;DR version:
With modern linux kernels (5.6 or later) there is no need to install haveged on a GNU/Linux box being used as a wireless router.

Detailed version:
Entropy is needed for fast communication between wireless router and wireless clients (due to wpa2 cryptography operations). It used to be recommended to run cat /proc/sys/kernel/random/entropy_avail on the router and, if result was less than 1000, to install haveged and run it as a daemon to augment router's entropy pool.
Turns out that linux 5.6 incorporated a haveged-inspired mechanism that generates entropy extremely quickly (~200 MiB/s), making the haveged daemon obsolete for this use case (fast entropy generation). Also, result of cat /proc/sys/kernel/random/entropy_avail is now meaningless (the command always returns "256").

Ref: https://github.com/jirka-h/haveged/issues/57

P.S. Would the forum moderator kindly delete haveged from Reply #18 (two places) and Reply #21 (one place)? I tried to delete it myself, but was denied ("You do not have permission to access this page").

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (mtbvfr) — Sun, 25 Feb 2024 21:17:36 +0000

Hi Bruno et al,

The nmcli command fixes things on the Lenovo L540.

After I enter my sudo password for running v2.3 of skinny-create-ap, there is no more output in the Terminal app. It simply returns to the Command Prompt.

Thanks! again, MTB.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Wed, 21 Feb 2024 04:10:38 +0000

If I run nmcli dev set wlan0 managed no, how do I undo the effects of this when I've finished using the Access Point

With nmcli dev set wlan0 managed yes

or does the command sudo pkill hostapd; sudo pkill -f 'dnsmasq.*/tmp/dnsmasq.conf' take care of this?

No.

Regarding wicd, its last stable release was in 2016 and last merge request from 2019. You could try it but the software is unmaintained.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (mtbvfr) — Tue, 20 Feb 2024 12:31:45 +0000

Hi Bruno,

NetworkManager is installed and running when I experience the handle_probe_req: send failed issue.

If I run nmcli dev set wlan0 managed no, how do I undo the effects of this when I've finished using the Access Point or does the command sudo pkill hostapd; sudo pkill -f 'dnsmasq.*/tmp/dnsmasq.conf' take care of this?

Is wicd a viable alternative to NetworkManager?

I will try testing tomorrow.

Thanks, MTB.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Mon, 19 Feb 2024 18:43:57 +0000

Hello again, mtbvfr. The nmcli command (see reply #25 just above) made the "handle_probe_req: send failed" messages disappear on my ThinkPad X230 with Devuan Daedalus Now the hotspot created with skinny-create-ap is completely stable.

I updated the script in reply #18 to include the nmcli command. I will go ahead and mark the thread as "Solved" (almost 7 years later--haha).

P.S. Please let me know if the nmcli command fixes things on your Lenovo L540. As for your other laptops, I'll leave those for you and other users to troubleshoot. I suggest scrutinizing the wifi hardware (not all hardware supports AP mode), excluding interference from network managers, and excluding interference from other software (e.g., rfkill).

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Mon, 19 Feb 2024 17:53:27 +0000

Sometimes, after a while, "handle_probe_req: send failed" is output multiple times.

Hi mtbvfr. I cannot reproduce the problem on my ThinkPad X200 with ALFA USB wifi adapter and Tiny Core Linux.

I don't normally run the skinny-create-ap script on my ThinkPad X230 with Devuan Daedalus but I gave it a try and I am able to reproduce your problem:

$ sudo skinny-create-ap wlx00127b20535e wlan0 DevuanHotspot TopSecret123
...
[I can connect to the hotspot using my phone, and phone can access the internet without any problems for several minutes]
wlx00127b20535e: INTERFACE-DISABLED 
wlx00127b20535e: INTERFACE-ENABLED 
[here the phone loses connection to the hotspot]
handle_probe_req: send failed
handle_probe_req: send failed
handle_probe_req: send failed
handle_probe_req: send failed
handle_probe_req: send failed
handle_probe_req: send failed

Since the hotspot works perfectly for several minutes before failing, I suspect the sudden failure is related to either power management or a networking daemon (e.g., NetworkManager) interfering.

One big difference between my X200 with TCL and X230 with Daedalus is that the latter uses NetworkManager.

Two questions for you, mtbvfr:

1. On your Lenovo L540 using Devuan Daedalus, is NetworkManager installed and running when you experience the "handle_probe_req: send failed" issue?

2. If you run nmcli dev set wlan0 managed no and then start the hotspot with sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123 does the "handle_probe_req: send failed" problem go away?

I'm testing #2 right now.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (aluma) — Mon, 19 Feb 2024 17:37:32 +0000

The idea is interesting, but one thing is not entirely good.
I don’t know how it is in other countries, but our cost ALFA AWUS036ACHM is approximately the same as TP-LINK Archer AX1500 Wi-Fi 6.
https://www.tp-link.com/us/home-network … er-ax1500/

But repeaters are simply much cheaper.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Mon, 19 Feb 2024 15:04:40 +0000

Hi mtbvfr. There are a lot of moving parts here. I will look at this on the weekend when I have more time.

But I do have two cents of advice that I can give right away:

Over the years, I've had many headaches of the type you're having now. I am not exaggerating when I say that all of my wifi-related headaches went away when I started using hand-picked hardware (ALFA AWUS036ACHM) and hand-picked minimalist OS (Tiny Core Linux) on my GNU/Linux box being used as a wireless router.

In other words, every problem I've ever encountered related to creating wifi hotspots were either due to poor hardware support or an OS that was getting in the way by doing things that I did not expect or desire.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (mtbvfr) — Mon, 19 Feb 2024 10:19:45 +0000

Hi Bruno et al,

Firstly, there is no mention of wlan0 in /etc/network/interfaces in any of the Operating Systems mentioned below.

My first test was on the Lenovo L540 (Intel Centrino Advanced-N 6235 WLAN card which has a 2x2 antenna) and using MX Linux 19.4 which can't detect the external Wi-Fi Hotspots (signals from Neighbours routers) around me. In other words, when I click on the Network Manager icon in the Notification Area of the Taskbar, no external Wi-Fi Hotpots are shown as being available.

The following output was produced even though I have the same packages installed as detailed in the BASH script but maybe they aren't the correct versions:

MX-19:~
$ sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123
[sudo] password for mtbvfr:
Configuration file: /tmp/hostapd.conf
nl80211: Could not configure driver mode
nl80211: deinit ifname=wlan0 disabled_11b_rates=0
nl80211 driver initialization failed.
wlan0: interface state UNINITIALIZED->DISABLED
wlan0: AP-DISABLED
wlan0: CTRL-EVENT-TERMINATING
hostapd_free_hapd_data: Interface wlan0 wasn't started

MX 19.4 has firmware-iwlwifi (Version: 20210818-1~mx19+1) installed.

The second test on the Lenovo L540, using Devuan daedalus, produced the following result:

devuanL540:~$ sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123
[sudo] password for mtbvfr:
wlan0: interface state UNINITIALIZED->ENABLED
wlan0: AP-ENABLED

I was then able to connect the phones to this hotspot and access the Internet.

When I clicked on the NetworkManager icon in the Notification Bar the following was output:

wlan0: INTERFACE-DISABLED
wlan0: INTERFACE-ENABLED

Sometimes, after a while, "handle_probe_req: send failed" is output multiple times.

One cause is when I turn on WiFi on the phone.

So, I have to use the sudo pkill hostapd; sudo pkill -f 'dnsmasq.*/tmp/dnsmasq.conf' command and then run skinny-create-ap again after which the following output is produced.

RTNETLINK answers: File exists
wlan0: interface state UNINITIALIZED->ENABLED
wlan0: AP-ENABLED

When the phone is reconnected, the following output is produced.

wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: authenticated
wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: associated (aid 1)
wlan0: AP-STA-CONNECTED xx:xx:xx:xx:xx:xx
wlan0: STA xx:xx:xx:xx:xx:xx RADIUS: starting accounting session 70EB940985C9755A
wlan0: STA xx:xx:xx:xx:xx:xx WPA: pairwise key handshake completed (RSN)
wlan0: EAPOL-4WAY-HS-COMPLETED xx:xx:xx:xx:xx:xx

When I turn off the WiFi on the phone the following is output.

wlan0: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: disassociated
wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)

In the same OS environment, when I click on the Network Manager icon in the Notification Area of the Taskbar, no external Wi-Fi Hotspots are shown as being available.

skinny-create-ap works on the Lenovo L540 under MX Linux 23.2 but, still, no external Wi-Fi Hotspots are shown as being available when I click on the Network Manager icon in the Notification Area of the Taskbar.

MX 23.2 has firmware-iwlwifi (Version: 20230210-5) installed.

On the Dell Latitude E6530, using Devuan daedalus, the following output was received when I tried using skinny-create-ap:

mtbvfr@devuan5Host:~$ sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123
[sudo] password for mtbvfr:
nl80211: Could not configure driver mode
nl80211: deinit ifname=wlan0 disabled_11b_rates=0
nl80211 driver initialization failed.
wlan0: interface state UNINITIALIZED->DISABLED
wlan0: AP-DISABLED
wlan0: CTRL-EVENT-TERMINATING
hostapd_free_hapd_data: Interface wlan0 wasn't started

When I click on the Network Manager icon, in the Notification Area of the Taskbar, external Wi-Fi Hotspots are shown as being available.

Devuan daedalus has firmware-iwlwifi (Version: 20230210-5) installed.

I get the same results for MX23.2 on the Dell Latitude E6530.

The command "iw list" produces the following output for the Dell Latitude E6530:

sudo iw list
Wiphy phy0
	wiphy index: 0
	max # scan SSIDs: 20
	max scan IEs length: 95 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 0 (up to 0m)
	Device supports RSN-IBSS.
	Supported Ciphers:
		* WEP40 (00-0f-ac:1)
		* WEP104 (00-0f-ac:5)
		* TKIP (00-0f-ac:2)
		* CCMP-128 (00-0f-ac:4)
		* CCMP-256 (00-0f-ac:10)
		* GCMP-128 (00-0f-ac:8)
		* GCMP-256 (00-0f-ac:9)
	Available Antennas: TX 0 RX 0
	Supported interface modes:
		 * IBSS
		 * managed
		 * monitor
	Band 1:
		Capabilities: 0x107e
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			No RX STBC
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT Max RX data rate: 450 Mbps
		HT TX/RX MCS rate indexes supported: 0-23
		Bitrates (non-HT):
			* 1.0 Mbps
			* 2.0 Mbps (short preamble supported)
			* 5.5 Mbps (short preamble supported)
			* 11.0 Mbps (short preamble supported)
			* 6.0 Mbps
			* 9.0 Mbps
			* 12.0 Mbps
			* 18.0 Mbps
			* 24.0 Mbps
			* 36.0 Mbps
			* 48.0 Mbps
			* 54.0 Mbps
		Frequencies:
			* 2412 MHz [1] (15.0 dBm)
			* 2417 MHz [2] (15.0 dBm)
			* 2422 MHz [3] (15.0 dBm)
			* 2427 MHz [4] (15.0 dBm)
			* 2432 MHz [5] (15.0 dBm)
			* 2437 MHz [6] (15.0 dBm)
			* 2442 MHz [7] (15.0 dBm)
			* 2447 MHz [8] (15.0 dBm)
			* 2452 MHz [9] (15.0 dBm)
			* 2457 MHz [10] (15.0 dBm)
			* 2462 MHz [11] (15.0 dBm)
			* 2467 MHz [12] (15.0 dBm) (no IR)
			* 2472 MHz [13] (15.0 dBm) (no IR)
	Band 2:
		Capabilities: 0x107e
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			No RX STBC
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT Max RX data rate: 450 Mbps
		HT TX/RX MCS rate indexes supported: 0-23
		Bitrates (non-HT):
			* 6.0 Mbps
			* 9.0 Mbps
			* 12.0 Mbps
			* 18.0 Mbps
			* 24.0 Mbps
			* 36.0 Mbps
			* 48.0 Mbps
			* 54.0 Mbps
		Frequencies:
			* 5180 MHz [36] (15.0 dBm) (no IR)
			* 5200 MHz [40] (15.0 dBm) (no IR)
			* 5220 MHz [44] (15.0 dBm) (no IR)
			* 5240 MHz [48] (15.0 dBm) (no IR)
			* 5260 MHz [52] (15.0 dBm) (no IR, radar detection)
			* 5280 MHz [56] (15.0 dBm) (no IR, radar detection)
			* 5300 MHz [60] (15.0 dBm) (no IR, radar detection)
			* 5320 MHz [64] (15.0 dBm) (no IR, radar detection)
			* 5500 MHz [100] (15.0 dBm) (no IR, radar detection)
			* 5520 MHz [104] (15.0 dBm) (no IR, radar detection)
			* 5540 MHz [108] (15.0 dBm) (no IR, radar detection)
			* 5560 MHz [112] (15.0 dBm) (no IR, radar detection)
			* 5580 MHz [116] (15.0 dBm) (no IR, radar detection)
			* 5600 MHz [120] (15.0 dBm) (no IR, radar detection)
			* 5620 MHz [124] (15.0 dBm) (no IR, radar detection)
			* 5640 MHz [128] (15.0 dBm) (no IR, radar detection)
			* 5660 MHz [132] (15.0 dBm) (no IR, radar detection)
			* 5680 MHz [136] (15.0 dBm) (no IR, radar detection)
			* 5700 MHz [140] (15.0 dBm) (no IR, radar detection)
			* 5745 MHz [149] (15.0 dBm) (no IR)
			* 5765 MHz [153] (15.0 dBm) (no IR)
			* 5785 MHz [157] (15.0 dBm) (no IR)
			* 5805 MHz [161] (15.0 dBm) (no IR)
			* 5825 MHz [165] (15.0 dBm) (no IR)
	Supported commands:
		 * new_interface
		 * set_interface
		 * new_key
		 * start_ap
		 * new_station
		 * new_mpath
		 * set_mesh_config
		 * set_bss
		 * authenticate
		 * associate
		 * deauthenticate
		 * disassociate
		 * join_ibss
		 * join_mesh
		 * remain_on_channel
		 * set_tx_bitrate_mask
		 * frame
		 * frame_wait_cancel
		 * set_wiphy_netns
		 * set_channel
		 * probe_client
		 * set_noack_map
		 * register_beacons
		 * start_p2p_device
		 * set_mcast_rate
		 * connect
		 * disconnect
		 * set_qos_map
		 * set_multicast_to_unicast
	software interface modes (can always be added):
		 * monitor
	interface combinations are not supported
	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
	Device supports TX status socket option.
	Device supports HT-IBSS.
	Device supports SAE with AUTHENTICATE command
	Device supports scan flush.
	Device supports per-vif TX power setting
	Driver supports full state transitions for AP/GO clients
	Driver supports a userspace MPM
	Device supports static SMPS
	Device supports dynamic SMPS
	Device supports configuring vdev MAC-addr on create.
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Supported TX frame types:
		 * IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-device: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
	Supported RX frame types:
		 * IBSS: 0x40 0xb0 0xc0 0xd0
		 * managed: 0x40 0xb0 0xd0
		 * AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * mesh point: 0xb0 0xc0 0xd0
		 * P2P-client: 0x40 0xd0
		 * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * P2P-device: 0x40 0xd0
	Supported extended features:
		* [ RRM ]: RRM
		* [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
		* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
		* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
		* [ EXT_KEY_ID ]: Extended Key ID support
		* [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
		* [ DEL_IBSS_STA ]: deletion of IBSS station support
		* [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
		* [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support

How is it that the Intel Centrino 6300 has AP and AP/VLAN as Supported TX and RX Frame Types and "start_ap" as a Supported Command but does not have AP and AP/VLAN as "Supported interface modes"?

Can anyone explain why not all WLAN cards have AP and AP/VLAN as "Supported interface modes"?

Regarding the Dell Latitude E6530, can anyone recommend a 3x3 Antenna PCIe Half Mini Card that can be used as an Access Point?

Can anyone explain why the L540 isn't detecting the external Wi-Fi Hotpots? Is it because it only has 2 antennas?

The Android phones can see these external Hotspots as can the Dell Latitude E6530.

The Centrino Ultimate-N 6300 supports 802.11a/g/n.

https://www.intel.com/content/www/us/en … tions.html

The Centrino Advanced-N 6235 supports 802.11a/b/g/n.

https://www.intel.com/content/www/us/en … tions.html

Thanks!!, MTB.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Fri, 16 Feb 2024 15:24:00 +0000

For sake of completeness, here are two variations on the skinny-create-ap script in reply #18. Both are tested and working for me.

Variation 1: nftables instead of iptables
If you would rather use the more modern nftables packet filtering interface for linux, only two tweaks need to be made to the instructions in reply #18.

1. Packages to install:

sudo apt install iproute2 nftables dnsmasq hostapd haveged

2. Replace the script's setup_nat() function with this version:

setup_nat()
{
	nft add table ip nat
	nft add chain ip nat postrouting { type nat hook postrouting priority 0\; policy accept\; }
	nft add rule ip nat postrouting masquerade
}

Variation 2: 5 GHz hotspot instead of 2.4 GHz
This assumes your hardware supports it.

For me, creating a 5 GHz hotspot is simply a matter of replacing the script's setup_ap() function with this version:

setup_ap()
{
	# create hostapd config file:
	echo "
ssid=$ssid
interface=$lan_if
driver=nl80211
country_code=US
channel=44
ignore_broadcast_ssid=0
hw_mode=a
auth_algs=1
wpa=2 
wpa_passphrase=$password
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP
rsn_pairwise=CCMP

# N
ieee80211n=1
wmm_enabled=1
ht_capab=[HT40+][HT40-][SHORT-GI-20][SHORT-GI-40]
" >/tmp/hostapd.conf

	# start hostapd:
	hostapd /tmp/hostapd.conf
}

You may need to tweak the country_code, channel, and ht_capab variables, but the above settings are pretty vanilla.

I hope that reply #18 and this reply #21 provide all you need to setup your own GNU/Linux-powered router

Happy hacking!

----------

PS1: Regarding range--If you're going to have a GNU/Linux laptop working full-time as a wireless router, you should consider using a USB wifi adapter rather than laptop's built-in wireless card because it will give you much better signal strength/range. I've been using an ALFA AWUS036ACHM for this purpose for years and it has served me well. You can find information about USB wifi adapters on linux here.

PS2: On "router" vs. "wifi repeater"--This seems like a silly distinction. In both cases, the laptop is creating a wireless access point and forwarding packets between two networks. Conceptually, it makes no difference whether your device is sharing a wired or wireless internet connection. Put another way, a "wifi repeater" is just a special kind of router where the networks on both sides of the router have a wireless physical layer.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Thu, 15 Feb 2024 14:42:48 +0000

You might want to disable automatic start of dnsmasq

Hi dzz. My skinny-create-ap script (in reply #18) starts dnsmasq in such a way that there is no clash if another instance of dnsmasq is already running. In general, multiple instances of dnsmasq can happily be running on the same machine as long as no two instances try to bind to the same interface.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (dzz) — Thu, 15 Feb 2024 13:15:49 +0000

Thanks GNUser for this thread. Useful for me as I have only wireless here (in some areas only) from a neighbour's router.

It seems create_ap is no longer maintained, so let's not bother with it.

True but its been forked, and maintained (in the last 2 months) elsewhere:

https://github.com/lakinduakash/linux-wifi-hotspot

There is a deb package with python-based GUI (but usable from cli only). Or build your own from the source, as did I. Working here, tested only on ceres so far, at least as wireless repeater. I'm using network-manager, that seems to be detected and not permanantly interfered with. I now have optional connection in a previously dead zone via another Devuan box.

Using 2x cheap usb wireless adapters, couldnt get either to work alone.

You might want to disable automatic start of dnsmasq (sysv-rc-conf) unless you got reason not to.

I will try your more minimal script at some point.

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Thu, 15 Feb 2024 04:55:30 +0000

Hi mtbvfr. Thanks for the private message with the requested info.

I understand your laptop has a successful internet connection using ethernet cable on the eth0 nic, and you want to share that internet connection wirelessly by creating an access point on wlan0.

Based on the information you provided, it seems wlan0 is ready to be used for this purpose--its driver/firmware is loaded and it supports AP mode.

It seems create_ap is no longer maintained, so let's not bother with it.

I managed to get this working on Devuan Daedalus as follows:

0. No need to uninstall or disable NetworkManager if you have it

1. Install some packages:

sudo apt install iproute2 iptables dnsmasq hostapd haveged

2. Create a script named skinny-create-ap somewhere in your PATH and make it executable. Script should look like this:

#!/bin/sh

# skinny-create-ap v2.3 (February 19, 2024)
# Bruno "GNUser" Dantas (GPLv3)

# Purpose: Turn a GNU/Linux system into a wireless router
# Dependencies: iproute2 iptables dnsmasq hostapd
# Not a dependency but highly recommended: haveged
# Syntax: $ sudo skinny-create-ap    
# Example usage: $ sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123
# To turn off the hotspot: $ sudo pkill hostapd; sudo pkill -f 'dnsmasq.*/tmp/dnsmasq.conf'

# user variables:
lan_if="$1"
wan_if="$2"
ssid="$3"
password="$4"
ip_stem=192.168.50
channel=6
#dns_server=1.1.1.1

main()
{
	prevent_nm_interference
	setup_kernel
	setup_nat
	setup_dhcp
	setup_ap
}

prevent_nm_interference()
{
	nmcli dev set "$lan_if" managed no >/dev/null 2>&1
}

setup_kernel()
{
	echo 1 >/proc/sys/net/ipv4/conf/"$wan_if"/forwarding
	echo 1 >/proc/sys/net/ipv4/ip_forward
}

setup_nat()
{
	iptables -t nat -A POSTROUTING -o "$wan_if" -j MASQUERADE
	iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
	iptables -A FORWARD -i "$lan_if" -o "$wan_if" -j ACCEPT
}

setup_dhcp()
{
	# first, bring up $lan_if and give it a suitable ip address:
	if ip link set "$lan_if" up; then
		ip addr add $ip_stem.1/24 dev "$lan_if"
	else
		echo "$lan_if does not exist or cannot be brought up. Make sure necessary driver +/- firmware is installed." >&2
		exit 1
	fi

	# create dnsmasq config file:
	echo "
dhcp-leasefile=/tmp/dnsmasq.leases
dhcp-range=$ip_stem.100,$ip_stem.200,255.255.255.0,24h
#dhcp-option-force=option:dns-server,$dns_server
" >/tmp/dnsmasq.conf

	# start dnsmasq (with care not to clash with any dnsmasq instances that might already be running):
	dnsmasq --interface="$lan_if" --bind-interfaces --except-interface=lo -C /tmp/dnsmasq.conf 
}

setup_ap()
{
	# create hostapd config file:
	echo "
ssid=$ssid
interface=$lan_if
driver=nl80211
channel=$channel
ignore_broadcast_ssid=0
hw_mode=g
auth_algs=1
wpa=2 
wpa_passphrase=$password
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP
rsn_pairwise=CCMP

# N
ieee80211n=1
wmm_enabled=1
" >/tmp/hostapd.conf

	# start hostapd:
	hostapd /tmp/hostapd.conf &
}

main

3. Run the script like this, for example:

sudo skinny-create-ap wlan0 eth0 DevuanHotspot TopSecret123

Now your wireless devices (e.g., Android phone) should be able to connect to DevuanHotspot using the password TopSecret123.

Let me know how you fare.

----------

PS1: Regarding radio frequency--the shell script above creates a 2.4 GHz 802.11n ("Wi-Fi 4") access point. 2.4 GHz is a good default because it has better range, simpler configuration, no regulatory issues, and broader hardware support in AP mode. If your wireless nic supports creation of 5 GHz AP and you would prefer 5 GHz, just tweak the "setup_ap" function as appropriate (let me know if you need help).

PS2: Regarding DNS lookups--if you want dnsmasq to tell wireless clients which dns sever to use, just uncomment the two lines where you see dns_server. If you leave those two lines commented, wireless clients will rely on the router (i.e., your laptop) to resolve domain names, which is a perfectly sane default.

PS3: To turn the hotspot off, run this command: sudo pkill hostapd; sudo pkill -f 'dnsmasq.*/tmp/dnsmasq.conf'

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (GNUser) — Wed, 14 Feb 2024 19:27:23 +0000

Hi, mtbvfr. I'll be happy to try to help you. First, two quick questions, please:

1. Does your laptop have a working internet connection?

2. Does the wireless interface that you want to use to create the access point show up when you run ifconfig -a?

Re: [SOLVED] GNU/Linux laptop as router, vpn router, or wifi repeater

dummy@example.com (mtbvfr) — Wed, 14 Feb 2024 05:05:08 +0000

@GNUser

Hi Folks,

Well, I finally got around to giving it a go but no luck. What do you suggest that I try?

The following is the output in Terminal.

command failed: No such device (-19)
ap0 could not be created within the time limit.
Cleaning up...
cat: /tmp/forwarding.saved: No such file or directory
cat: /tmp/ip_forward.saved: No such file or directory
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
iptables: Bad rule (does a matching rule exist in that chain?).
Cannot find device "ap0"
Device "ap0" does not exist.
command failed: No such device (-19)

The following is some of my System Information.

System:
  Host: devuanL540 Kernel: 6.1.0-10-amd64 arch: x86_64 bits: 64 Desktop: Xfce
    v: 4.18.1 Distro: Devuan GNU/Linux 5 (daedalus)
Machine:
  Type: Laptop System: LENOVO product: 20AUS0P500 v: ThinkPad L540
    serial: 
  Mobo: LENOVO model: 20AUS0P500 v: 0B98405 Std serial: 
    UEFI: LENOVO v: J4ET64WW(1.64) date: 05/29/2014
Network:
  Device-1: Intel Ethernet I217-V driver: e1000e
  IF: eth0 state: up speed: 1000 Mbps duplex: full mac: xx:xx:xx:xx:xx:xx
  Device-2: Intel Centrino Advanced-N 6235 driver: iwlwifi
  IF: wlan0 state: down mac: xx:xx:xx:xx:xx:xx

The following is from the iwconfig command.

lo        no wireless extensions.

eth0      no wireless extensions.

wlan0     IEEE 802.11  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=15 dBm
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

The following is from the "iw list" command.

Wiphy phy0
	wiphy index: 0
	max # scan SSIDs: 20
	max scan IEs length: 195 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 0 (up to 0m)
	Device supports RSN-IBSS.
	Supported Ciphers:
		* WEP40 (00-0f-ac:1)
		* WEP104 (00-0f-ac:5)
		* TKIP (00-0f-ac:2)
		* CCMP-128 (00-0f-ac:4)
		* CCMP-256 (00-0f-ac:10)
		* GCMP-128 (00-0f-ac:8)
		* GCMP-256 (00-0f-ac:9)
	Available Antennas: TX 0 RX 0
	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
	Band 1:
		Capabilities: 0x107e
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			No RX STBC
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT Max RX data rate: 300 Mbps
		HT TX/RX MCS rate indexes supported: 0-15
		Bitrates (non-HT):
			* 1.0 Mbps
			* 2.0 Mbps (short preamble supported)
			* 5.5 Mbps (short preamble supported)
			* 11.0 Mbps (short preamble supported)
			* 6.0 Mbps
			* 9.0 Mbps
			* 12.0 Mbps
			* 18.0 Mbps
			* 24.0 Mbps
			* 36.0 Mbps
			* 48.0 Mbps
			* 54.0 Mbps
		Frequencies:
			* 2412 MHz [1] (15.0 dBm)
			* 2417 MHz [2] (15.0 dBm)
			* 2422 MHz [3] (15.0 dBm)
			* 2427 MHz [4] (15.0 dBm)
			* 2432 MHz [5] (15.0 dBm)
			* 2437 MHz [6] (15.0 dBm)
			* 2442 MHz [7] (15.0 dBm)
			* 2447 MHz [8] (15.0 dBm)
			* 2452 MHz [9] (15.0 dBm)
			* 2457 MHz [10] (15.0 dBm)
			* 2462 MHz [11] (15.0 dBm)
			* 2467 MHz [12] (15.0 dBm) (no IR)
			* 2472 MHz [13] (15.0 dBm) (no IR)
	Band 2:
		Capabilities: 0x107e
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			No RX STBC
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT Max RX data rate: 300 Mbps
		HT TX/RX MCS rate indexes supported: 0-15
		Bitrates (non-HT):
			* 6.0 Mbps
			* 9.0 Mbps
			* 12.0 Mbps
			* 18.0 Mbps
			* 24.0 Mbps
			* 36.0 Mbps
			* 48.0 Mbps
			* 54.0 Mbps
		Frequencies:
			* 5180 MHz [36] (15.0 dBm) (no IR)
			* 5200 MHz [40] (15.0 dBm) (no IR)
			* 5220 MHz [44] (15.0 dBm) (no IR)
			* 5240 MHz [48] (15.0 dBm) (no IR)
			* 5260 MHz [52] (15.0 dBm) (no IR, radar detection)
			* 5280 MHz [56] (15.0 dBm) (no IR, radar detection)
			* 5300 MHz [60] (15.0 dBm) (no IR, radar detection)
			* 5320 MHz [64] (15.0 dBm) (no IR, radar detection)
			* 5500 MHz [100] (15.0 dBm) (no IR, radar detection)
			* 5520 MHz [104] (15.0 dBm) (no IR, radar detection)
			* 5540 MHz [108] (15.0 dBm) (no IR, radar detection)
			* 5560 MHz [112] (15.0 dBm) (no IR, radar detection)
			* 5580 MHz [116] (15.0 dBm) (no IR, radar detection)
			* 5600 MHz [120] (15.0 dBm) (no IR, radar detection)
			* 5620 MHz [124] (15.0 dBm) (no IR, radar detection)
			* 5640 MHz [128] (15.0 dBm) (no IR, radar detection)
			* 5660 MHz [132] (15.0 dBm) (no IR, radar detection)
			* 5680 MHz [136] (15.0 dBm) (no IR, radar detection)
			* 5700 MHz [140] (15.0 dBm) (no IR, radar detection)
			* 5745 MHz [149] (15.0 dBm) (no IR)
			* 5765 MHz [153] (15.0 dBm) (no IR)
			* 5785 MHz [157] (15.0 dBm) (no IR)
			* 5805 MHz [161] (15.0 dBm) (no IR)
			* 5825 MHz [165] (15.0 dBm) (no IR)
	Supported commands:
		 * new_interface
		 * set_interface
		 * new_key
		 * start_ap
		 * new_station
		 * new_mpath
		 * set_mesh_config
		 * set_bss
		 * authenticate
		 * associate
		 * deauthenticate
		 * disassociate
		 * join_ibss
		 * join_mesh
		 * remain_on_channel
		 * set_tx_bitrate_mask
		 * frame
		 * frame_wait_cancel
		 * set_wiphy_netns
		 * set_channel
		 * probe_client
		 * set_noack_map
		 * register_beacons
		 * start_p2p_device
		 * set_mcast_rate
		 * connect
		 * disconnect
		 * set_qos_map
		 * set_multicast_to_unicast
	WoWLAN support:
		 * wake up on disconnect
		 * wake up on magic packet
		 * wake up on pattern match, up to 20 patterns of 16-128 bytes,
		   maximum packet offset 0 bytes
		 * can do GTK rekeying
		 * wake up on GTK rekey failure
		 * wake up on EAP identity request
		 * wake up on rfkill release
	software interface modes (can always be added):
		 * AP/VLAN
		 * monitor
	valid interface combinations:
		 * #{ managed } <= 1, #{ AP } <= 1,
		   total <= 2, #channels <= 1, STA/AP BI must match
		 * #{ managed } <= 2,
		   total <= 2, #channels <= 1
	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
	Device supports TX status socket option.
	Device supports HT-IBSS.
	Device supports SAE with AUTHENTICATE command
	Device supports scan flush.
	Device supports per-vif TX power setting
	Driver supports full state transitions for AP/GO clients
	Driver supports a userspace MPM
	Device supports static SMPS
	Device supports dynamic SMPS
	Device supports configuring vdev MAC-addr on create.
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Supported TX frame types:
		 * IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
		 * P2P-device: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
	Supported RX frame types:
		 * IBSS: 0x40 0xb0 0xc0 0xd0
		 * managed: 0x40 0xb0 0xd0
		 * AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * mesh point: 0xb0 0xc0 0xd0
		 * P2P-client: 0x40 0xd0
		 * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
		 * P2P-device: 0x40 0xd0
	Supported extended features:
		* [ RRM ]: RRM
		* [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
		* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
		* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
		* [ EXT_KEY_ID ]: Extended Key ID support
		* [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
		* [ DEL_IBSS_STA ]: deletion of IBSS station support
		* [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
		* [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support

Thanks!