1.\" Copyright (c) 2004 Daniel Hartmeier 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 8.\" - Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" - Redistributions in binary form must reproduce the above 11.\" copyright notice, this list of conditions and the following 12.\" disclaimer in the documentation and/or other materials provided 13.\" with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16.\" "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 25.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26.\" POSSIBILITY OF SUCH DAMAGE. 27.\" 28.\" $OpenBSD: cdce.4,v 1.26 2020/05/12 13:03:52 schwarze Exp $ 29.\" 30.Dd $Mdocdate: May 12 2020 $ 31.Dt CDCE 4 32.Os 33.Sh NAME 34.Nm cdce 35.Nd USB Communication Device Class Ethernet device 36.Sh SYNOPSIS 37.Cd "cdce* at uhub?" 38.Sh DESCRIPTION 39The 40.Nm 41driver provides support for USB Host-to-Host (aka USB-to-USB) bridges 42based on the USB Communication Device Class (CDC) and Ethernet subclass, 43including the following: 44.Pp 45.Bl -bullet -compact -offset indent 46.It 47Acer Labs USB 2.0 Data Link 48.It 49Dell Wireless 5530 50.It 51Dell Wireless 5540 52.It 53FRITZ!Box Fon ata 1020 54.It 55G.Mate YP3X00 56.It 57Lenovo Thinkpad USB 3.0 Ethernet adapter (FRU 03X6903) 58.It 59Motorola USBNET 60.It 61NetChip EthernetGadget 62.It 63Prolific PL-2501 64.It 65Sony Ericsson K610i 66.It 67Sony Ericsson F3705g 68.It 69Yota LU156 70.It 71ZTE MF831 LTE USB modem 72.It 73ZTE MF920V portable LTE WiFi router 74.It 75Zyxel P-971M 76.El 77.Pp 78The USB bridge appears as a regular network interface on both sides, 79transporting Ethernet frames. 80USB 1.x bridges support speeds of up to 12Mbps, and USB 2.0 speeds of 81up to 480Mbps. 82Packets are 83received and transmitted over separate USB bulk transfer endpoints. 84.Pp 85The 86.Nm 87driver does not support different media types or options. 88For more information on configuring this device, see 89.Xr ifconfig 8 . 90.Sh DIAGNOSTICS 91.Bl -diag 92.It "cdce0: extra ethernet descriptor" 93There is more than one Ethernet descriptor. 94.It "cdce0: no data interface" 95The data interface announced by the union descriptor cannot be found. 96.It "cdce0: no descriptor for interrupt endpoint N" 97.It "cdce0: interface alternate setting N failed" 98.It "cdce0: no descriptor for bulk endpoint N" 99.It "cdce0: could not find data bulk in/out" 100For a manually added USB vendor/product, these errors indicate 101that the bridge is not compatible with the driver. 102.It "cdce0: watchdog timeout" 103A packet was queued for transmission and a transmit command was 104issued, however the device failed to acknowledge the transmission 105before a timeout expired. 106.It "cdce0: no memory for rx list -- packet dropped!" 107Memory allocation through MGETHDR or MCLGET failed, the system 108is running low on mbufs. 109.It "cdce0: abort/close rx/tx/interrupt pipe failed" 110.It "cdce0: rx/tx list init failed" 111.It "cdce0: open rx/tx/interrupt pipe failed" 112.It "cdce0: usb error on rx/tx" 113.El 114.Sh SEE ALSO 115.Xr arp 4 , 116.Xr intro 4 , 117.Xr netintro 4 , 118.Xr usb 4 , 119.Xr hostname.if 5 , 120.Xr ifconfig 8 121.Rs 122.%T "Universal Serial Bus Class Definitions for Communication Devices" 123.%U https://www.usb.org/document-library/class-definitions-communication-devices-12 124.Re 125.Rs 126.%T "Data sheet Prolific PL-2501 Host-to-Host Bridge/Network Controller" 127.Re 128.Sh HISTORY 129The 130.Nm 131device driver first appeared in 132.Ox 3.6 . 133.Sh AUTHORS 134.An -nosplit 135The 136.Nm 137driver was written by 138.An Craig Boston Aq Mt craig@tobuj.gank.org 139based on the 140.Xr aue 4 141driver written by 142.An Bill Paul Aq Mt wpaul@windriver.com 143and ported to 144.Ox 145by 146.An Daniel Hartmeier Aq Mt dhartmei@openbsd.org . 147.Sh CAVEATS 148Many USB devices notoriously fail to report their class and interfaces 149correctly. 150Undetected products might work flawlessly when their vendor and product IDs 151are added to the driver manually. 152