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.\" 27.Dd November 15, 2002 28.Dt TARG 4 29.Os 30.Sh NAME 31.Nm targ 32.Nd SCSI target emulator driver 33.Sh SYNOPSIS 34.Cd device targ 35.Sh DESCRIPTION 36The 37.Nm 38driver provides an interface for usermode programs to emulate SCSI target 39devices. 40A sample program that emulates a disk drive (similar to 41.Xr da 4 ) 42can be found in 43.Pa /usr/share/examples/scsi_target . 44.Pp 45The 46.Nm 47driver supplies control devices, 48.Pa /dev/targ0 , 49.Pa /dev/targ1 , 50etc. 51If a device is already in use, open(2) will fail and 52.Va errno 53will be set to 54.Er EBUSY . 55After opening the device, the file descriptor must be bound to a 56specific bus/target/LUN and enabled to process CCBs using the 57.Dv TARGIOCENABLE 58ioctl. 59The process then uses 60.Xr write 2 61to send CCBs to the SIM and 62.Xr poll 2 63or 64.Xr kqueue 2 65to see if responses are ready. 66Pointers to completed CCBs are returned via 67.Xr read 2 . 68Any data transfers requested by the user CCBs are done via zero-copy IO. 69.Sh IOCTLS 70The following 71.Xr ioctl 2 72calls are defined in the header file 73.Aq Pa cam/scsi/scsi_targetio.h . 74.Bl -tag -width ".Dv TARGIOCDISABLE" 75.It Dv TARGIOCENABLE 76.Pq Vt "struct ioc_enable_lun" 77Enable target mode on the LUN specified by the following structure: 78.Bd -literal -offset indent 79struct ioc_enable_lun { 80 path_id_t path_id; 81 target_id_t target_id; 82 lun_id_t lun_id; 83 int grp6_len; 84 int grp7_len; 85}; 86.Ed 87.Pp 88The selected path (bus), target, and LUN must not already be in use or 89.Er EADDRINUSE 90is returned. 91If 92.Va grp6_len 93or 94.Va grp7_len 95are non-zero, reception of vendor-specific commands 96is enabled. 97.It Dv TARGIOCDISABLE 98Disable target mode and abort all pending CCBs. 99The CCBs may optionally be read as they complete. 100.Dv TARGIOCENABLE 101can then be called to activate a different LUN. 102Multiple disable calls have no effect. 103The 104.Xr close 2 105system call automatically disables target mode if enabled. 106.It Dv TARGIOCDEBUG 107.Pq Vt int 108Enables 109.Dv CAM_PERIPH 110debugging if the argument is non-zero, otherwise disables 111it. 112.El 113.Sh FILES 114.Bl -tag -width ".Pa /sys/cam/scsi/scsi_target.c" -compact 115.It Aq Pa cam/scsi/scsi_targetio.h 116describes the usermode interface. 117.It Pa /sys/cam/scsi/scsi_target.c 118is the driver source file. 119.It Pa /dev/targ* 120are the control devices. 121.El 122.Sh SEE ALSO 123.Pa /usr/share/examples/scsi_target , 124.Xr ahc 4 , 125.Xr isp 4 , 126.Xr scsi 4 127.Rs 128.%T "FreeBSD Target Information" 129.%O http://www.root.org/~nate/freebsd/ 130.Re 131.Sh BUGS 132Currently, only the 133.Xr ahc 4 134and 135.Xr isp 4 136drivers fully support target mode. 137.Pp 138The 139.Xr ahc 4 140driver does not support tagged queuing in target mode. 141.Sh AUTHORS 142.An -nosplit 143The 144.Nm 145driver first appeared in 146.Fx 3.0 147and was written by 148.An Justin T. Gibbs . 149It was rewritten 150for 151.Fx 5.0 152by 153.An Nate Lawson Aq nate@root.org . 154