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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2014-12-15 23:08:59 +0000 |
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| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2014-12-15 23:08:59 +0000 |
| commit | e0fc82203d677a6f1e808e9a1a46176c109d89be (patch) | |
| tree | e9609209b755e3f7a8480aea86601ffe9d4ca540 /doc/s6-sudoc.html | |
| download | s6-networking-e0fc82203d677a6f1e808e9a1a46176c109d89be.tar.xz | |
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diff --git a/doc/s6-sudoc.html b/doc/s6-sudoc.html new file mode 100644 index 0000000..0ca9918 --- /dev/null +++ b/doc/s6-sudoc.html @@ -0,0 +1,80 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>s6-networking: the s6-sudoc program</title> + <meta name="Description" content="s6-networking: the s6-sudoc program" /> + <meta name="Keywords" content="s6-networking s6-sudoc sudo setuid suid unix privilege gain getpeereid client" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">s6-networking</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>s6-sudoc</tt> program </h1> + +<p> +<tt>s6-sudoc</tt> talks to a peer <a href="s6-sudod.html">s6-sudod</a> +program over a Unix socket, passing it command-line arguments, environment +variables and standard descriptors. +</p> + +<h2> Interface </h2> + +<pre> + s6-sudoc [ -e ] [ -t <em>timeoutconn</em> ] [ -T <em>timeoutrun</em> ] [ <em>args...</em> ] +</pre> + +<ul> + <li> s6-sudoc transmits its standard input, standard output and standard error +via fd-passing over a Unix socket that must be open on its descriptors 6 and 7. + It expects a <a href="s6-sudod.html">s6-sudod</a> process to be receiving them +on the other side. </li> +<li> It also transmits its command-line arguments <em>args</em>, and also its +environment by default. Note that s6-sudod will not necessarily accept all the +environment variables that s6-sudoc tries to transmit. </li> + <li> s6-sudoc waits for the server program run by s6-sudod to finish. It exits +the same exit code as the server program. If the server program is killed by a +signal, s6-sudoc kills itself with the same signal. </li> +</ul> + +<h2> Options </h2> + +<ul> + <li> <tt>-e</tt> : do not attempt to transmit any environment variables +to <a href="s6-sudod.html">s6-sudod</a>. </li> + <li> <tt>-t <em>timeoutconn</em></tt> : if s6-sudod has not +managed to process the given information and start the server program after +<em>timeoutconn</em> milliseconds, give up. By default, <em>timeoutconn</em> +is 0, meaning infinite. Note that there is no reason to set up a nonzero +<em>timeoutconn</em> with a large value: s6-sudod is not supposed to block. +The option is only there to protect against ill-written services. </li> + <li> <tt>-T <em>timeoutrun</em></tt> : if the server program +has not exited after <em>timeoutrun</em> milliseconds, give up. By +default, <em>timeoutrun</em> is 0, meaning infinite. </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> If s6-sudoc is killed, or exits after <em>timeoutrun</em> milliseconds, +while the server program is still running, s6-sudod will send a SIGTERM and a +SIGCONT to the server program - but this does not guarantee that it will die. +If the server program keeps running, it might still read from the file that +was s6-sudoc's stdin, or write to the files that were s6-sudod's stdout or +stderr. <strong>This is a potential security risk</strong>. +Administrators should audit their server programs to make sure this does not +happen. </li> + <li> More generally, anything using signals or terminals will not be +handled transparently by the s6-sudoc + s6-sudod mechanism. The mechanism +was designed to allow programs to gain privileges in specific situations: +short-lived, simple, noninteractive processes. It was not designed to emulate +the full suid functionality and will not go out of its way to do so. </li> +</ul> + +</body> +</html> |