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