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9fbbfb5757a1e3e86d7dea62c4e63ffc2303ca2bAutomatic Updater - Copyright (C) 2004, 2005, 2007-2009 Internet Systems Consortium, Inc. ("ISC")
75c0816e8295e180f4bc7f10db3d0d880383bc1cMark Andrews - Copyright (C) 2000, 2001 Internet Software Consortium.
4a14ce5ba00ab7bc55c99ffdcf59c7a4ab902721Automatic Updater - Permission to use, copy, modify, and/or distribute this software for any
6ea1b817e31b89a627e146fe69e23ea0a64c89ecBob Halley - purpose with or without fee is hereby granted, provided that the above
6ea1b817e31b89a627e146fe69e23ea0a64c89ecBob Halley - copyright notice and this permission notice appear in all copies.
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
8a66318e41ed14c5a88130e8c362610e8faa2121Mark Andrews - PERFORMANCE OF THIS SOFTWARE.
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4abdfc917e6635a7c81d1f931a0c79227e72d025Mark Andrews<a name="id2476275"></a><div class="titlepage"></div>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span class="application">lwresd</span> — lightweight resolver daemon</p>
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews<div class="cmdsynopsis"><p><code class="command">lwresd</code> [<code class="option">-c <em class="replaceable"><code>config-file</code></em></code>] [<code class="option">-C <em class="replaceable"><code>config-file</code></em></code>] [<code class="option">-d <em class="replaceable"><code>debug-level</code></em></code>] [<code class="option">-f</code>] [<code class="option">-g</code>] [<code class="option">-i <em class="replaceable"><code>pid-file</code></em></code>] [<code class="option">-m <em class="replaceable"><code>flag</code></em></code>] [<code class="option">-n <em class="replaceable"><code>#cpus</code></em></code>] [<code class="option">-P <em class="replaceable"><code>port</code></em></code>] [<code class="option">-p <em class="replaceable"><code>port</code></em></code>] [<code class="option">-s</code>] [<code class="option">-t <em class="replaceable"><code>directory</code></em></code>] [<code class="option">-u <em class="replaceable"><code>user</code></em></code>] [<code class="option">-v</code>] [<code class="option">-4</code>] [<code class="option">-6</code>]</p></div>
9fbbfb5757a1e3e86d7dea62c4e63ffc2303ca2bAutomatic Updater<a name="id2543467"></a><h2>DESCRIPTION</h2>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span><strong class="command">lwresd</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein is the daemon providing name lookup
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein services to clients that use the BIND 9 lightweight resolver
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein library. It is essentially a stripped-down, caching-only name
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein server that answers queries using the BIND 9 lightweight
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein resolver protocol rather than the DNS protocol.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span><strong class="command">lwresd</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein listens for resolver queries on a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein UDP port on the IPv4 loopback interface, 127.0.0.1. This
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein means that <span><strong class="command">lwresd</strong></span> can only be used by
9fbbfb5757a1e3e86d7dea62c4e63ffc2303ca2bAutomatic Updater processes running on the local machine. By default, UDP port
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein number 921 is used for lightweight resolver requests and
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Incoming lightweight resolver requests are decoded by the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein server which then resolves them using the DNS protocol. When
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the DNS lookup completes, <span><strong class="command">lwresd</strong></span> encodes
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the answers in the lightweight resolver format and returns
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein them to the client that made the request.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein If <code class="filename">/etc/resolv.conf</code> contains any
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <code class="option">nameserver</code> entries, <span><strong class="command">lwresd</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein sends recursive DNS queries to those servers. This is similar
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein to the use of forwarders in a caching name server. If no
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <code class="option">nameserver</code> entries are present, or if
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein forwarding fails, <span><strong class="command">lwresd</strong></span> resolves the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein queries autonomously starting at the root name servers, using
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein a built-in list of root server hints.
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews Use IPv4 only even if the host machine is capable of IPv6.
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <code class="option">-4</code> and <code class="option">-6</code> are mutually
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews Use IPv6 only even if the host machine is capable of IPv4.
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <code class="option">-4</code> and <code class="option">-6</code> are mutually
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews<dt><span class="term">-c <em class="replaceable"><code>config-file</code></em></span></dt>
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews Use <em class="replaceable"><code>config-file</code></em> as the
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews configuration file instead of the default,
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <code class="filename">/etc/lwresd.conf</code>.
731cc132f22dbc9e0ecd7035dce314a61076d31bAutomatic Updater <code class="option">-c</code> can not be used with <code class="option">-C</code>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-C <em class="replaceable"><code>config-file</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Use <em class="replaceable"><code>config-file</code></em> as the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein configuration file instead of the default,
731cc132f22dbc9e0ecd7035dce314a61076d31bAutomatic Updater <code class="option">-C</code> can not be used with <code class="option">-c</code>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-d <em class="replaceable"><code>debug-level</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Set the daemon's debug level to <em class="replaceable"><code>debug-level</code></em>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Debugging traces from <span><strong class="command">lwresd</strong></span> become
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein more verbose as the debug level increases.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Run the server in the foreground (i.e. do not daemonize).
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Run the server in the foreground and force all logging
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews<dt><span class="term">-i <em class="replaceable"><code>pid-file</code></em></span></dt>
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews Use <em class="replaceable"><code>pid-file</code></em> as the
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews PID file instead of the default,
18fa75b694d056da4be3ebfc2185d007d4882752Automatic Updater <code class="filename">/var/run/lwresd/lwresd.pid</code>.
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews<dt><span class="term">-m <em class="replaceable"><code>flag</code></em></span></dt>
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews Turn on memory usage debugging flags. Possible flags are
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <em class="replaceable"><code>usage</code></em>,
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <em class="replaceable"><code>trace</code></em>,
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <em class="replaceable"><code>record</code></em>,
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <em class="replaceable"><code>size</code></em>, and
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <em class="replaceable"><code>mctx</code></em>.
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews These correspond to the ISC_MEM_DEBUGXXXX flags described in
a1b05dea35aa30b152a47115e18bbe679d3fcf19Mark Andrews <code class="filename"><isc/mem.h></code>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-n <em class="replaceable"><code>#cpus</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Create <em class="replaceable"><code>#cpus</code></em> worker threads
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein to take advantage of multiple CPUs. If not specified,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <span><strong class="command">lwresd</strong></span> will try to determine the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein number of CPUs present and create one thread per CPU.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein If it is unable to determine the number of CPUs, a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein single worker thread will be created.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-P <em class="replaceable"><code>port</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Listen for lightweight resolver queries on port
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>port</code></em>. If
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not specified, the default is port 921.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-p <em class="replaceable"><code>port</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Send DNS lookups to port <em class="replaceable"><code>port</code></em>. If not
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein specified, the default is port 53. This provides a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein way of testing the lightweight resolver daemon with a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein name server that listens for queries on a non-standard
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein port number.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Write memory usage statistics to <code class="filename">stdout</code>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein This option is mainly of interest to BIND 9 developers
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein and may be removed or changed in a future release.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-t <em class="replaceable"><code>directory</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein to <em class="replaceable"><code>directory</code></em> after
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein processing the command line arguments, but before
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein reading the configuration file.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein This option should be used in conjunction with the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <code class="option">-u</code> option, as chrooting a process
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein running as root doesn't enhance security on most
d71e2e0c61df16ff37c9934c371a4a60c08974f7Mark Andrews systems; the way <code class="function">chroot(2)</code> is
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein defined allows a process with root privileges to
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein escape a chroot jail.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-u <em class="replaceable"><code>user</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein to <em class="replaceable"><code>user</code></em> after completing
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein privileged operations, such as creating sockets that
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein listen on privileged ports.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Report the version number and exit.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="filename">/etc/resolv.conf</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The default configuration file.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="filename">/var/run/lwresd.pid</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The default process-id file.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <span class="citerefentry"><span class="refentrytitle">lwres</span>(3)</span>,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <span class="citerefentry"><span class="refentrytitle">resolver</span>(5)</span>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span class="corpauthor">Internet Systems Consortium</span>