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diff --git a/doc/skabus-rpc-daemon.html b/doc/skabus-rpc-daemon.html new file mode 100644 index 0000000..bd9b575 --- /dev/null +++ b/doc/skabus-rpc-daemon.html @@ -0,0 +1,137 @@ +<html> + <head> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>skabus: the skabus-rpc-daemon program</title> + <meta name="Description" content="skabus: the skabus-rpc-daemon program" /> + <meta name="Keywords" content="skabus skabus-rpc unix linux socket rpc mapper server daemon" /> + <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">skabus</a><br /> +<a href="//skarnet.org/software/">Software</a><br /> +<a href="//skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>skabus-rpc-daemon</tt> program </h1> + +<p> +<tt>skabus-rpc-daemon</tt> is a RPC mapper <em>daemon</em>, i.e. a +long-lived program. +It listens on a Unix domain socket, then +accepts client connections. It allows clients to register interfaces +and methods; it transmits queries from a client Q to the appropriate +client R that can handle them; it then transmits the answer back to +client Q. +</p> + +<h2> Interface </h2> + +<pre> + skabus-rpc-daemon [ -1 ] [ -v <em>verbosity</em> ] [ -D | -d ] [ -c <em>maxconn</em> ] [ -b <em>backlog</em> ] [ -G <em>gidlist</em> ] [ -g <em>gid</em> ] [ -u <em>uid</em> ] [ -U ] [ -t <em>clienttimeout</em> ] [ -T <em>lameducktimeout</em> ] [ -i <em>rulesdir</em> | -x <em>rulesfile</em> ] [ -S | -s ] [ -J | -j ] <em>path</em> +</pre> + +<ul> + <li> skabus-rpc-daemon binds to the Unix domain socket at path. </li> + <li> If applicable, it drops root privileges. </li> + <li> It listens to its socket and accepts client connections. </li> + <li> Clients are handled as described in the +<a href="skabus-rpcd.html">skabus-rpcd</a> page. </li> +</ul> + +<p> + skabus-rpc-daemon is just a wrapper that binds to its socket and drops +privileges before executing into +<a href="skabus-rpcd.html">skabus-rpcd</a>. For details of the daemon's +operation, see the <a href="skabus-rpcd.html">skabus-rpcd</a> documentation. +</p> + +<h2> Options </h2> + +<ul> + <li> <tt>-1</tt> : write a newline to stdout, before +closing it, right after binding and listening to the Unix socket. +If stdout is suitably redirected, this can be used by monitoring +programs to check when the server is ready to accept connections. </li> + <li> <tt>-v <em>verbosity</em></tt> : be quiet, normally +verbose, or more verbose, depending on if <em>verbosity</em> is 0, +1, or more. The default is 1. </li> + <li> <tt>-d</tt> : allow instant rebinding to the same path +even if it has been used not long ago - this is the SO_REUSEADDR flag to +<a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/setsockopt.html">setsockopt()</a> +and is generally used with server programs. This is the default. Note that +<em>path</em> will be deleted if it already exists at program start time. </li> + <li> <tt>-D</tt> : disallow instant rebinding to the same path. </li> + <li> <tt>-c <em>maxconn</em></tt> : accept at most +<em>maxconn</em> concurrent client connections. Default is 40. It is +impossible to set it higher than the value of the SKABUS_RPC_MAX macro, +which is 1000. Client connections to this server are usually long-lived; +make sure to correctly tune that number to your needs. </li> + <li> <tt>-b <em>backlog</em></tt> : set a maximum of +<em>backlog</em> backlog connections on the socket. Extra +connection attempts will rejected by the kernel. </li> + <li> <tt>-G <em>gidlist</em></tt> : change skabus-rpc-daemon's +supplementary group list to <em>gidlist</em> after binding the socket. +This is only valid when run as root. <em>gidlist</em> must be a +comma-separated list of numerical group IDs. </li> + <li> <tt>-g <em>gid</em></tt> : change skabus-rpc-daemon's groupid +to <em>gid</em> after binding the socket. This is only valid when run +as root. </li> + <li> <tt>-u <em>uid</em></tt> : change skabus-rpc-daemon's userid +to <em>uid</em> after binding the socket. This is only valid when run +as root. </li> + <li> <tt>-U</tt> : change skabus-rpc-daemon's user id, group id and +supplementary group list +according to the values of the UID, GID and GIDLIST environment variables +after binding the socket. This is only valid when run as root. +This can be used with the +<a href="s6-envuidgid.html">s6-envuidgid</a> +program to easily script a service that binds to a privileged socket +then drops its privileges to those of a named non-root account. </li> + <li> <tt>-t <em>clienttimeout</em></tt> : disconnect a client +if it's in the middle of an operation and it has not written or read any +data in <em>clienttimeout</em> milliseconds. By default, <em>clienttimeout</em> +is 0, which means infinite. </li> + <li> <tt>-T <em>lameducktimeout</em></tt> : give clients +<em>lameducktimeout</em> milliseconds to finish their current operation +before exiting after skabus-rpc-daemon has received a SIGTERM. By default, +<em>lameducktimeout</em> is 0, which means infinite. </li> + <li> <tt>-x <em>rulesfile</em></tt> : read access rights +configuration from CDB file <em>rulesfile</em>. </li> + <li> <tt>-i <em>rulesdir</em></tt> : read access rights +configuration from the filesystem in directory <em>rulesdir</em>. </li> + <li> <tt>-S</tt> : paranoid identification mode. Disallows +unspecified clients from registering +under any identifier. This is the default. </li> + <li> <tt>-s</tt> : free registration. Allows unspecified clients +to register with any identifier. </li> + <li> <tt>-J</tt> : paranoid interface registration. Disallows +unspecified clients from registering interfaces. This is the default. </li> + <li> <tt>-j</tt> : free interface registration. Allows unspecified clients +to register any interface name. </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> skabus-rpc-daemon does not interpret its options itself. It just +dispatches them to the appropriate program on the command line that +it builds. </li> + <li> From the user's point of view, skabus-rpc-daemon behaves like a +long-lived process, even if the long-lived process itself is called +<a href="skabus-rpcd.html">skabus-rpcd</a>. Every operational detail +of skabus-rpcd applies to skabus-rpc-daemon as well; in particular, +make sure to properly +<a href="skabus-rpcd.html#configuration">configure the clients' +access rights</a>. </li> + <li> skabus-rpc-daemon is meant to be used in a s6 run script, as +a supervised local service. It does not fork itself or write to syslog. +However, it can be run under any infrastructure, including other +supervision infrastructures, OpenRC, systemd, or SysV scripts. </li> +</ul> + +</body> +</html> |