Date: Tue, 22 Sep 2020 23:02:02 +0000 (UTC) From: Warner Losh <imp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r366027 - head/share/man/man9 Message-ID: <202009222302.08MN22H3076890@repo.freebsd.org>
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Author: imp Date: Tue Sep 22 23:02:01 2020 New Revision: 366027 URL: https://svnweb.freebsd.org/changeset/base/366027 Log: Add devctl_notify(9) man page Document the calls to send messages to userland via devctl. devctl_notify will create a message for the specified system, subsystem and type, optionally adding additional information. Reviewed by: bcr Differential Revision: https://reviews.freebsd.org/D26520 Added: head/share/man/man9/devctl_notify.9 (contents, props changed) Modified: head/share/man/man9/Makefile Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Tue Sep 22 23:01:57 2020 (r366026) +++ head/share/man/man9/Makefile Tue Sep 22 23:02:01 2020 (r366027) @@ -121,6 +121,7 @@ MAN= accept_filter.9 \ DEVICE_SHUTDOWN.9 \ DEV_MODULE.9 \ dev_refthread.9 \ + devctl_notify.9 \ devctl_process_running.9 \ devctl_safe_quote_sb.9 \ devctl_ Added: head/share/man/man9/devctl_notify.9 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/share/man/man9/devctl_notify.9 Tue Sep 22 23:02:01 2020 (r366027) @@ -0,0 +1,78 @@ +.\" +.\" Copyright (c) 2020 M Warner Losh +.\" +.\" This program is free software. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 22, 2020 +.Dt DEVCTL_NOTIFY 9 +.Os +.Sh NAME +.Nm devctl_notify +.Nd Send a message, via devctl, to userland +.Sh SYNOPSIS +.In sys/devctl.h +.Ft void +.Fn devctl_notify "const char *system" "const char *subsystem" "const char *type" "const char *data" +.Sh DESCRIPTION +Send a notification to user land via +.Xr devctl 4 . +See +.Xr devctl 4 +for the format of these messages. +.Pp +The +.Nm +function creates a string using the following template: +.Bd -literal +snprintf(buffer, sizeof(buffer), "!system=%s subsystem=%s type=%s", + system, subsystem, type); +.Ed +.Pp +The +.Va system , +.Va subsystem , +and +.Va type +pointers cannot be NULL. +.Pp +The +.Va data +argument may be NULL (for no additions) or a message formatted +properly for +.Xr devctl 4 . +A space will be added to the above template and this argument copied +verbatim to form the message passed to userland. +Senders should balance between only passing data that userland can not +discover itself and sending all the data userland will want to use to +decide what to do with the message. +.Pp +The current total message length limit is just under 1kb. +Senders should try to remain well below this limit. +.Sh SEE ALSO +.Xr devctl 4 , +.Xr devd 8 +.Sh AUTHORS +This manual page was written by +.An M. Warner Losh
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