.\" Copyright (c) 2010 Damien Bergamini <damien.bergamini@free.fr>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" $FreeBSD$
.\"
.Dd June 9, 2016
.Dt URTWN 4
.Os
.Sh NAME
.Nm urtwn
.Nd Realtek RTL8188CU/RTL8188RU/RTL8188EU/RTL8192CU USB IEEE 802.11b/g/n wireless network device
.Sh SYNOPSIS
.Cd "options URTWN_WITHOUT_UCODE"
.Pp
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device ehci"
.Cd "device uhci"
.Cd "device ohci"
.Cd "device usb"
.Cd "device urtwn"
.Cd "device wlan"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_urtwn_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver supports USB 2.0 wireless network devices based on Realtek
RTL8188CUS, RTL8188CE-VAU, RTL8188EUS, RTL8188RU and RTL8192CU chipsets.
.Pp
The RTL8188CUS and RTL8188EUS are highly integrated 802.11n adapters that
combine a MAC, a 1T1R capable baseband and an RF in a single chip.
They operate in the 2GHz spectrum only.
The RTL8188RU is a high-power variant of the RTL8188CUS.
The RTL8188CE-VAU is a PCI Express Mini Card adapter that attaches
to the USB interface.
.Pp
The RTL8192CU is a highly integrated multiple-in, multiple-out (MIMO)
802.11n adapter that combines a MAC, a 2T2R capable baseband and an
RF in a single chip.
It operates in the 2GHz spectrum only.
.Pp
All chips have hardware support for  WEP, AES-CCM and TKIP encryption.
.Pp
The driver supports
.Cm station ,
.Cm adhoc ,
.Cm hostap ,
and
.Cm monitor
mode operation.
Only one virtual interface may be configured at any time.
.Pp
This driver may use the firmware built with the
.Nm urtwnfw
module for some additional features
(when URTWN_WITHOUT_UCODE kernel option is not set).
.Sh FILES
.Bl -tag -width ".Pa /usr/share/doc/legal/realtek.LICENSE" -compact
.It Pa /usr/share/doc/legal/realtek.LICENSE
.Nm
firmware license
.El
.Sh HARDWARE
The
.Nm
driver supports Realtek RTL8188CU/RTL8188RU/RTL8188EU/RTL8192CU based USB
IEEE 802.11b/g/n wireless network adapters, including:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It Alfa AWUS036NHR v2
.It ASUS USB-N10 NANO
.It Belkin F7D1102 Surf Wireless Micro
.It D-Link DWA-123 rev D1
.It D-Link DWA-125 rev D1
.It D-Link DWA-131
.It Edimax EW-7811Un
.It Elecom WDC-150SU2M
.It Netgear WNA1000M
.It Realtek RTL8192CU
.It Realtek RTL8188CUS
.It TP-LINK TL-WN723N v3
.It TP-LINK TL-WN725N v2
.El
.Sh EXAMPLES
Join an existing BSS network (i.e., connect to an access point):
.Bd -literal -offset indent
ifconfig wlan create wlandev urtwn0 inet 192.168.0.20 \e
    netmask 0xffffff00
.Ed
.Pp
Join a specific BSS network with network name
.Dq Li my_net :
.Pp
.Dl "ifconfig wlan create wlandev urtwn0 ssid my_net up"
.Pp
Join a specific BSS network with 64-bit WEP encryption:
.Bd -literal -offset indent
ifconfig wlan create wlandev urtwn0 ssid my_net \e
        wepmode on wepkey 0x1234567890 weptxkey 1 up
.Ed
.Pp
Create an IBSS network with 128-bit WEP encryption on the channel 4:
.Bd -literal -offset indent
ifconfig wlan0 create wlandev urtwn0 wlanmode adhoc ssid my_net \e
	wepmode on wepkey 0x01020304050607080910111213 weptxkey 1 \e
	channel 4
.Ed
.Pp
Join/create an 802.11b IBSS network with network name
.Dq Li my_net :
.Bd -literal -offset indent
ifconfig wlan0 create wlandev urtwn0 wlanmode adhoc
ifconfig wlan0 inet 192.168.0.22 netmask 0xffffff00 ssid my_net \e
	mode 11b
.Ed
.Pp
Create an 802.11g host-based access point:
.Bd -literal -offset indent
ifconfig wlan0 create wlandev urtwn0 wlanmode hostap
ifconfig wlan0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \e
	mode 11g
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "urtwn%d: error %d, could not read firmware %s"
For some reason, the driver was unable to read the microcode file from the
filesystem.
The file might be missing or corrupted.
.It "urtwn%d: device timeout"
A frame dispatched to the hardware for transmission did not complete in time.
The driver will reset the hardware.
This should not happen.
.El
.Sh SEE ALSO
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr urtwnfw 4 ,
.Xr usb 4 ,
.Xr wlan 4 ,
.Xr wlan_amrr 4 ,
.Xr wlan_ccmp 4 ,
.Xr wlan_tkip 4 ,
.Xr wlan_wep 4 ,
.Xr ifconfig 8 ,
.Xr wpa_supplicant 8
.Rs
.%T Realtek
.%U http://www.realtek.com.tw
.Re
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 4.9
and
.Fx 10.0 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Damien Bergamini Aq Mt damien@openbsd.org .
.Sh CAVEATS
The
.Nm
driver currently does not support A-MPDU 802.11n transmit aggregation.
.Pp
For non-RTL8188EUS chips
.Dq "rate control"
algorithm is absent; this may result in increased packet loss in noisy
networks.