RTW(4)

✨ NAME ✨

okay bestie, welcome to RTW(4) — this is the rtw page from the Kernel Interfaces Manual, and it’s literally all about the Realtek RTL8180L IEEE 802.11b wireless network driver. 💖

🦋 SYNOPSIS 🦋

vibe check, here’s how it attaches:

rtw* at cardbus? function ?
rtw* at pci? dev ? function ?

💅 DESCRIPTION 💅

rtw is the driver for PCI/CardBus 802.11b wireless adapters based on the Realtek RTL8180L. no cap. ✨

These devices can have a whole lineup of radio transceivers — for example the Philips SA2400A, Maxim MAX2820, and GCT GRF5101 — but heads up, not all of them are currently supported. 🫶

vibe check: these are the modes the rtw driver can operate in:

• BSS mode — also known as infrastructure mode. This is what you use when associating with an access point, and all traffic passes through it. This mode is the default. 👑
• IBSS mode — also known as IEEE ad-hoc mode or peer-to-peer mode. This is the standardized method of operating without an access point. Stations associate with a service set. However, actual connections between stations are peer-to-peer.
• Host AP — in this mode the driver acts as an access point (base station) for other cards. main character energy, honestly.
• monitor mode — in this mode the driver is able to receive packets without associating with an access point. This disables the internal receive filter and enables the card to capture packets from networks which it wouldn't normally have access to, or to scan for access points. 💅

rtw supports software WEP. Wired Equivalent Privacy (WEP) is the de facto encryption standard for wireless networks. It can be typically configured in one of three modes: no encryption; 40-bit encryption; or 104-bit encryption. Unfortunately, due to serious weaknesses in WEP protocol it is strongly recommended that it not be used as the sole mechanism to secure wireless communication. WEP is not enabled by default.

🚨 bestie, that WEP warning is not a vibe: serious weaknesses, so don’t make it your only security move.

🎀 CONFIGURATION 🎀

The rtw driver can be configured at runtime with ifconfig(8) or on boot with ifconfig.if(5) using the following parameters:

• bssid bssid — set the BSSID you want.
• -bssid — unset the desired BSSID. In this mode the interface will automatically select a BSSID, which is the default.
• chan n — set the channel (radio frequency) the driver uses, based on the given channel ID n.
• -chan — unset the desired channel. In this mode the driver will automatically select a channel, which is the default.
• media media — the rtw driver supports the following media types:
  • autoselect — enable autoselection of the media type and options.
  • DS1 — set 802.11b DS 1Mbps operation.
  • DS2 — set 802.11b DS 2Mbps operation.
  • DS5 — set 802.11b DS 5.5Mbps operation.
  • DS11 — set 802.11b DS 11Mbps operation.
• mediaopt opts — the rtw driver supports the following media options:
  • hostap — select Host AP operation.
  • ibss — select IBSS operation.
  • monitor — select monitor mode.
• -mediaopt opts — disable the specified media options on the driver and return it to the default mode of operation (BSS).
• ssid id — set the network ID. The id can either be any text string up to 32 characters in length, or a series of hexadecimal digits up to 64 digits. An empty id string allows the interface to connect to any available access points. By default the rtw driver uses an empty string. Note that network ID is synonymous with Extended Service Set ID (ESSID).
• nwkey key — enable WEP encryption using the specified key. The key can either be a string, a series of hexadecimal digits (preceded by 0x), or a set of keys of the form n:k1,k2,k3,k4, where n specifies which of the keys will be used for transmitted packets, and the four keys, k1 through k4, are configured as WEP keys. If a set of keys is specified, a comma (,) within the key must be escaped with a backslash (\). Note that if multiple keys are used, their order must be the same within the network. rtw is capable of using both 40-bit (5 characters or 10 hexadecimal digits) or 104-bit (13 characters or 26 hexadecimal digits) keys.
• -nwkey — disable WEP encryption. This is the default mode of operation.
• nwkey persist — enable WEP encryption with the persistent key stored in the network card.

🔥 HARDWARE 🔥

The following adapters should work — slay:

• Belkin F5D6020 V3 — CardBus
• Buffalo WLI-CB-B11 — CardBus
• Corega CG-WLCB11V3 — CardBus
• D-Link DWL-610 — CardBus
• Level-One WPC-0101 — CardBus
• Linksys WPC11 v4 — CardBus
• Netgear MA521 — CardBus
• Ovislink AirLive WL-1120PCM — CardBus
• Planet WL-3553 — CardBus
• TrendNET TEW-266PC — CardBus
• VCTnet PC-11B1 — CardBus

🌈 EXAMPLES 🌈

The following ifconfig.if(5) example creates a host-based access point on boot:

inet 192.168.1.1 255.255.255.0 NONE media autoselect \
        mediaopt hostap ssid my_net chan 11

Configure rtw0 for WEP, using hex key 0x1deadbeef1:

# ifconfig rtw0 nwkey 0x1deadbeef1

Return rtw0 to its default settings:

# ifconfig rtw0 -bssid -chan media autoselect \
        ssid "" -nwkey

Join an existing BSS network, my_net:

# ifconfig rtw0 192.168.1.1 netmask 0xffffff00 ssid my_net

👑 SEE ALSO 👑

Go peek at these, iykyk: arp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4), ifconfig.if(5), ifconfig(8).

Realtek, http://www.realtek.com.tw.

🕰️ HISTORY 🕰️

The rtw device driver first appeared in NetBSD 3.0 and then in OpenBSD 3.7. ✨

🫶 AUTHORS 🫶

The rtw driver was written by David Young ⟨dyoung@NetBSD.org⟩ and ported to OpenBSD by Jonathan Gray <jsg@openbsd.org>, who wrote this man page. 💖

💀 BUGS 💀

this is the rough part, bestie: only the Philips SA2400A and Maxim MAX2820 RF transceivers are known to work. Devices incorporating a GCT RF transceiver are not supported due to a lack of documentation from GCT. 😭

While PCI devices will attach most of them are not able to transmit. 💀

---

and that’s the whole RTW(4) page, bestie — this cutie came from the Debian manual set, dated December 29, 2004. periodt. 🫶