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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/index.html | 6 | ||||
| -rw-r--r-- | doc/s6-devd.html | 4 | ||||
| -rw-r--r-- | doc/s6-uevent-listener.html | 99 | ||||
| -rw-r--r-- | doc/s6-uevent-spawner.html | 79 | ||||
| -rw-r--r-- | doc/upgrade.html | 11 |
5 files changed, 195 insertions, 4 deletions
diff --git a/doc/index.html b/doc/index.html index a899be8..a0fe7d7 100644 --- a/doc/index.html +++ b/doc/index.html @@ -32,7 +32,7 @@ <li> A Linux-based system with a standard C development environment </li> <li> GNU make, version 4.0 or later </li> <li> <a href="http://skarnet.org/software/skalibs/">skalibs</a> version -2.3.1.0 or later. It's a build-time requirement. It's also a run-time +2.3.1.2 or later. It's a build-time requirement. It's also a run-time requirement if you link against the shared version of the skalibs library. </li> </ul> @@ -47,7 +47,7 @@ library. </li> <h3> Download </h3> <ul> - <li> The current released version of s6-linux-utils is <a href="s6-linux-utils-2.0.1.0.tar.gz">2.0.1.0</a>. </li> + <li> The current released version of s6-linux-utils is <a href="s6-linux-utils-2.0.2.0.tar.gz">2.0.2.0</a>. </li> <li> Alternatively, you can checkout a copy of the s6-linux-utils git repository: <pre> git clone git://git.skarnet.org/s6-linux-utils </pre> </li> </ul> @@ -79,6 +79,8 @@ the previous versions of s6-linux-utils and the current one. </li> <ul> <li><a href="s6-chroot.html">The <tt>s6-chroot</tt> program</a></li> <li><a href="s6-devd.html">The <tt>s6-devd</tt> program</a></li> +<li><a href="s6-uevent-listener.html">The <tt>s6-uevent-listener</tt> program</a></li> +<li><a href="s6-uevent-spawner.html">The <tt>s6-uevent-spawner</tt> program</a></li> <li><a href="s6-freeramdisk.html">The <tt>s6-freeramdisk</tt> program</a></li> <li><a href="s6-halt.html">The <tt>s6-halt</tt> program</a></li> <li><a href="s6-hostname.html">The <tt>s6-hostname</tt> program</a></li> diff --git a/doc/s6-devd.html b/doc/s6-devd.html index 5ae6160..c67429a 100644 --- a/doc/s6-devd.html +++ b/doc/s6-devd.html @@ -36,7 +36,7 @@ hotplug events, as the <em>udev</em> program does. </li> the event variables added to the environment, just as if <em>prog...</em> had been registered in <tt>/proc/sys/kernel/hotplug</tt>. </li> <li> However, unlike the kernel, s6-devd spawns the <em>prog...</em> helpers -sequentially: it waits for an instance to finish before spawning another one. </li> +sequentially: it waits for an instance to finish before spawning another one. </li> <li> s6-devd is a long-lived program; it exits 0 when it receives a SIGTERM. If a helper program is alive at that time, s6-devd waits for it to die before exiting. </li> @@ -68,7 +68,7 @@ fork and logs to stderr.) </li> even if you are not using the <tt>-t</tt> option to s6-devd. Since helpers are spawned sequentially, slow helpers can make events queue up and fill the netlink kernel buffer. </li> - <li> If you are using <a href="http://busybox.net/">busybox</a> and want a + <li> If you are using <a href="http://busybox.net/">busybox</a> and want a minimal udev-style dynamic <tt>/dev</tt> handling, <tt>/sbin/mdev</tt> is a suitable <em>prog...</em> helper. </li> <li> The point of s6-devd is that it runs the helpers sequentially, so it solves diff --git a/doc/s6-uevent-listener.html b/doc/s6-uevent-listener.html new file mode 100644 index 0000000..9050e9f --- /dev/null +++ b/doc/s6-uevent-listener.html @@ -0,0 +1,99 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>s6-linux-utils: the s6-uevent-listener program</title> + <meta name="Description" content="s6-linux-utils: the s6-uevent-listener program" /> + <meta name="Keywords" content="s6 linux administration root utilities devd mdev udev s6-uevent-listener uevent" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">s6-linux-utils</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>s6-uevent-listener</tt> program </h1> + +<p> +<tt>s6-uevent-listener</tt> spawns a long-lived helper program. +It then listens to the netlink interface for uevents (also called +"hotplug" or "udev" events), and passes those events to the +helper program's standard input, using a simple format. +</p> + +<h2> Interface </h2> + +<pre> + s6-uevent-listener [ -v <em>verbosity</em> ] [ -b kbufsz ] <em>prog...</em> +</pre> + +<ul> + <li> s6-uevent-listener spawns <em>prog...</em> with a pipe writing to +<em>prog</em>' stdin. </li> + <li> s6-uevent-listener binds to the netlink interface and listens for +hotplug events, as the <em>udev</em> program does. </li> + <li> It tranmits event information to <em>prog</em> via the pipe. </li> + <li> s6-uevent-listener, as well as <em>prog</em>, are long-lived programs. +When it receives a SIGTERM, s6-uevent-listener stops listening; it will +exit as soon as it has flushed its event queue to <em>prog</em>. </li> +</ul> + +<h2> Options </h2> + +<ul> + <li> <tt>-v</tt> <em>verbosity</em> : be more or less verbose. +Default verbosity is 1. 0 will only print fatal error messages, 3 will +print warnings every time the netlink interface sends something +unexpected. </li> + <li> <tt>-b</tt> <em>kbufsz</em> : try and reserve a kernel buffer of +<em>kbufsz</em> bytes for the netlink queue. Too large a buffer wastes kernel memory; +too small a buffer risks losing events. The default is 65536. </li> +</ul> + +<h2> Protocol </h2> + +<ul> + <li> <em>prog</em> should read a series of events on its stdin, and exit +on EOF. </li> + <li> An event is a series of null-terminated strings as they are sent by +the kernel to the netlink; s6-uevent-listener adds a final empty string +(i.e. an additional null character) to mark the end of the series. </li> + <li> The first string is a short description of the event; it normally +contains the string "@/". Other strings after the first are of the form +"VARIABLE=value", and describe the environment which a hotplug helper +for the event (registered in <tt>/proc/sys/kernel/hotplug</tt>) would be +spawned with. </li> + <li> Example (newlines added for clarity): <pre> +add@/class/input/input9/mouse2\0 +ACTION=add\0 +DEVPATH=/class/input/input9/mouse2\0 +SUBSYSTEM=input\0 +SEQNUM=106\0 +PHYSDEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2Â2/2Â2:1.0 +PHYSDEVBUS=usb\0 +PHYSDEVDRIVER=usbhid\0 +MAJOR=13\0 +MINOR=34\0 +\0 </pre> </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> s6-uevent-listener is a daemon; it should be run under a proper supervision system such +as <a href="http://skarnet.org/software/s6/">s6</a>. </li> +<li> If you are running s6-uevent-listener, <em>prog...</em> should be the +only program handling uevents, which means that +<tt>/proc/sys/kernel/hotplug</tt> should be empty. </li> + <li> If you want the serialization benefit of the netlink, but still +want to spawn a program such as <a href="http://busybox.net/">busybox</a>'s +or <a href="http://landley.net/toybox/">toybox</a>'s <tt>mdev</tt>, use +<tt><a href="s6-uevent-spawner.html">s6-uevent-spawner</a> mdev</tt> as +s6-uevent-listener's <em>prog</em>. </li> +</ul> + +</body> +</html> diff --git a/doc/s6-uevent-spawner.html b/doc/s6-uevent-spawner.html new file mode 100644 index 0000000..e9be726 --- /dev/null +++ b/doc/s6-uevent-spawner.html @@ -0,0 +1,79 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>s6-linux-utils: the s6-uevent-spawner program</title> + <meta name="Description" content="s6-linux-utils: the s6-uevent-spawner program" /> + <meta name="Keywords" content="s6 linux administration root utilities devd mdev udev hotplug" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">s6-linux-utils</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>s6-uevent-spawner</tt> program </h1> + +<p> +<tt>s6-uevent-spawner</tt> listens to its standard input for +netlink-style events, and launches a helper program for every event, +similarly to what the hotplug interface does. +</p> + +<p> + It is meant to be used together with +<a href="s6-uevent-listener.html">s6-uevent-listener</a>. +</p> + +<h2> Interface </h2> + +<pre> + s6-uevent-spawner [ -v <em>verbosity</em> ] [ -l <em>linevar</em> ] [ -t <em>l</em>:<em>t</em>:<em>k</em> ] <em>prog...</em> +</pre> + +<ul> + <li> s6-uevent-spawner listens to its stdin for a series of strings +representing kernel uevents, as formatted by +<a href="s6-uevent-listener.html">s6-uevent-listener</a>. </li> + <li> For every event it reads, it spawns <em>prog...</em> with +the event variables added to the environment, just as if <em>prog...</em> +had been registered in <tt>/proc/sys/kernel/hotplug</tt>. However, +it reads the events sequentially, and waits for a <em>prog</em> instance +to finish before spawning another one. </li> + <li> When s6-uevent-spawner receives EOF: if an instance of +<em>prog</em> is alive, it first waits for it to die. Then it exits +0. </li> +</ul> + +<h2> Options </h2> + +<ul> + <li> <tt>-v</tt> <em>verbosity</em> : be more or less verbose. +Default verbosity is 1. 0 only prints fatal error messages. 3 is too much. </li> + <li> <tt>-l</tt> <em>linevar</em> : make the event description +(i.e. the first string in the netlink message announcing the event) +available in <em>prog</em> under the environment variable <em>linevar</em>. +By default, this first string is ignored - it is not needed, all the +event information is already in the other variables. </li> + <li> <tt>-t</tt> <em>l:t:k</em> : If <em>l</em>, <em>t</em> or <em>k</em> is +specified, they specify timeouts; by default, they are infinite. +If <em>prog...</em> is still alive after <em>l</em> milliseconds, s6-devd sends +it a SIGTERM. Then, if <em>prog...</em> is still alive after <em>t</em> more +milliseconds, s6-devd sends it a SIGKILL. Then, if <em>prog...</em> is still +alive after <em>k</em> more milliseconds, s6-uevent-spawner yells and exits 99. </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> The <em>prog...</em> helper should be very short-lived, +even if you are not using the <tt>-t</tt> option to s6-devd. Since helpers are +spawned sequentially, slow helpers can make events queue up and fill up +buffers. </li> +</ul> + +</body> +</html> diff --git a/doc/upgrade.html b/doc/upgrade.html index b9dcfeb..847324d 100644 --- a/doc/upgrade.html +++ b/doc/upgrade.html @@ -17,6 +17,17 @@ <h1> What has changed in s6-linux-utils </h1> +<h2> in 2.0.2.0 </h2> + +<ul> + <li> skalibs dependency bumped to 2.3.1.1 </li> + <li> New commands: +<a href="s6-uevent-listener.html">s6-uevent-listener</a> and +<a href="s6-uevent-spawner.html">s6-uevent-spawner</a> <li> + <li> <a href="s6-devd.html">s6-devd</a> is now a wrapper +around those commands. </li> +</ul> + <h2> in 2.0.1.0 </h2> <ul> |