1.\" Copyright (c) 2002 2.\" Nate Lawson. 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.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Neither the name of the author nor the names of any co-contributors 10.\" may be used to endorse or promote products derived from this software 11.\" without specific prior written permission. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY Nate Lawson AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD: src/share/man/man4/targ.4,v 1.3.2.1 2003/02/18 22:07:11 njl Exp $ 26.\" $DragonFly: src/share/man/man4/targ.4,v 1.6 2008/07/09 16:23:55 thomas Exp $ 27.\" 28.Dd November 15, 2002 29.Dt TARG 4 30.Os 31.Sh NAME 32.Nm targ 33.Nd SCSI target emulator driver 34.Sh SYNOPSIS 35.Cd device targ 36.Sh DESCRIPTION 37The 38.Nm 39driver provides an interface for usermode programs to emulate SCSI target 40devices. 41A sample program that emulates a disk drive (similar to 42.Xr da 4 ) 43can be found in 44.Pa /usr/share/examples/scsi_target . 45.Pp 46The 47.Nm 48driver supplies control devices, 49.Pa /dev/targ0 , 50.Pa /dev/targ1 , 51etc. 52If a device is already in use, 53.Xr open 2 54will fail and 55.Va errno 56will be set to 57.Er EBUSY . 58After opening the device, the file descriptor must be bound to a 59specific bus/target/LUN and enabled to process CCBs using the 60.Dv TARGIOCENABLE 61ioctl. 62The process then uses 63.Xr write 2 64to send CCBs to the SIM and 65.Xr poll 2 66or 67.Xr kqueue 2 68to see if responses are ready. 69Pointers to completed CCBs are returned via 70.Xr read 2 . 71Any data transfers requested by the user CCBs are done via zero-copy IO. 72.Sh IOCTLS 73The following 74.Xr ioctl 2 75calls are defined in the header file 76.In bus/cam/scsi/scsi_targetio.h . 77.Bl -tag -width ".Dv TARGIOCDISABLE" 78.It Dv TARGIOCENABLE 79.Pq Vt "struct ioc_enable_lun" 80Enable target mode on the LUN specified by the following structure: 81.Bd -literal -offset indent 82struct ioc_enable_lun { 83 path_id_t path_id; 84 target_id_t target_id; 85 lun_id_t lun_id; 86 int grp6_len; 87 int grp7_len; 88}; 89.Ed 90.Pp 91The selected path (bus), target, and LUN must not already be in use or 92.Er EADDRINUSE 93is returned. 94If 95.Va grp6_len 96or 97.Va grp7_len 98are non-zero, reception of vendor-specific commands 99is enabled. 100.It Dv TARGIOCDISABLE 101Disable target mode and abort all pending CCBs. 102The CCBs may optionally be read as they complete. 103.Dv TARGIOCENABLE 104can then be called to activate a different LUN. 105Multiple disable calls have no effect. 106The 107.Xr close 2 108system call automatically disables target mode if enabled. 109.It Dv TARGIOCDEBUG 110.Pq Vt int 111Enables 112.Dv CAM_PERIPH 113debugging if the argument is non-zero, otherwise disables 114it. 115.El 116.Sh FILES 117.Bl -tag -width ".Pa /sys/bus/cam/scsi/scsi_target.c" -compact 118.It In bus/cam/scsi/scsi_targetio.h 119describes the usermode interface. 120.It Pa /sys/bus/cam/scsi/scsi_target.c 121is the driver source file. 122.It Pa /dev/targ* 123are the control devices. 124.El 125.Sh SEE ALSO 126.Pa /usr/share/examples/scsi_target , 127.Xr ahc 4 , 128.Xr isp 4 , 129.Xr scsi 4 130.Rs 131.%T "FreeBSD Target Information" 132.%O http://www.root.org/~nate/freebsd/ 133.Re 134.Sh AUTHORS 135.An -nosplit 136The 137.Nm 138driver first appeared in 139.Fx 3.0 140and was written by 141.An Justin T. Gibbs . 142It was rewritten 143for 144.Fx 5.0 145by 146.An Nate Lawson Aq nate@root.org . 147.Sh BUGS 148Currently, only the 149.Xr ahc 4 150and 151.Xr isp 4 152drivers fully support target mode. 153.Pp 154The 155.Xr ahc 4 156driver does not support tagged queuing in target mode. 157