1.\" 2.\" Copyright (c) 1998, 1999 Kenneth D. Merry. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD: src/share/man/man4/pass.4,v 1.5.2.5 2001/08/17 13:08:39 ru Exp $ 29.\" $DragonFly: src/share/man/man4/pass.4,v 1.3 2007/09/06 11:29:30 swildner Exp $ 30.\" 31.Dd October 10, 1998 32.Dt PASS 4 33.Os 34.Sh NAME 35.Nm pass 36.Nd CAM application passthrough driver 37.Sh SYNOPSIS 38.Cd device pass 39.Cd device pass2 at scbus0 target 3 unit 0 40.Sh DESCRIPTION 41The 42.Nm 43driver provides a way for userland applications to issue CAM CCBs to the 44kernel. 45.Pp 46Since the 47.Nm 48driver allows direct access to the CAM subsystem, system administrators 49should exercise caution when granting access to this driver. If used 50improperly, this driver can allow userland applications to crash a machine 51or cause data loss. 52.Pp 53The 54.Nm 55driver attaches to every 56.Tn SCSI 57device found in the system. 58Since it attaches to every device, it provides a generic means of accessing 59.Tn SCSI 60devices, and allows the user to access devices which have no 61"standard" peripheral driver associated with them. 62.Sh KERNEL CONFIGURATION 63It is only necessary to configure one 64.Nm 65device in the kernel; 66.Nm 67devices are automatically allocated as 68.Tn SCSI 69devices are found. 70.Sh IOCTLS 71.Bl -tag -width ".Dv CAMGETPASSTHRU" 72.It Dv CAMIOCOMMAND 73This ioctl takes most kinds of CAM CCBs and passes them through to the CAM 74transport layer for action. Note that some CCB types are not allowed 75through the passthrough device, and must be sent through the 76.Xr xpt 4 77device instead. Some examples of xpt-only CCBs are 78.Dv XPT_SCAN_BUS , 79.Dv XPT_DEV_MATCH , 80.Dv XPT_RESET_BUS , 81.Dv XPT_SCAN_LUN , 82.Dv XPT_ENG_INQ , 83and 84.Dv XPT_ENG_EXEC . 85These CCB types have various attributes that make it illogical or 86impossible to service them through the passthrough interface. 87.It Dv CAMGETPASSTHRU 88This ioctl takes an 89.Dv XPT_GDEVLIST 90CCB, and returns the passthrough device 91corresponding to the device in question. Although this ioctl is available 92through the 93.Nm 94driver, it is of limited use, since the caller must already know that 95the device in question is a passthrough device if they're issuing this 96ioctl. It is probably more useful to issue this ioctl through the 97.Xr xpt 4 98device. 99.El 100.Sh FILES 101.Bl -tag -width /dev/passn -compact 102.It Pa /dev/pass Ns Ar n 103Character device nodes for the 104.Nm 105driver. There should be one of these for each device accessed through the 106CAM subsystem. 107.El 108.Sh DIAGNOSTICS 109None. 110.Sh SEE ALSO 111.Xr cam 3 , 112.Xr cam_cdbparse 3 , 113.Xr xpt 4 , 114.Xr camcontrol 8 115.Sh HISTORY 116The CAM passthrough driver first appeared in 117.Fx 3.0 . 118.Sh AUTHORS 119.An Kenneth Merry Aq ken@FreeBSD.org 120.Sh BUGS 121It might be nice to have a way to asynchronously send CCBs through the 122passthrough driver. This would probably require some sort of read/write 123interface or an asynchronous ioctl interface. 124