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diff --git a/static/freebsd/man4/ng_async.4 3.html b/static/freebsd/man4/ng_async.4 3.html new file mode 100644 index 00000000..f2f373fe --- /dev/null +++ b/static/freebsd/man4/ng_async.4 3.html @@ -0,0 +1,139 @@ +<table class="head"> + <tr> + <td class="head-ltitle">NG_ASYNC(4)</td> + <td class="head-vol">Device Drivers Manual</td> + <td class="head-rtitle">NG_ASYNC(4)</td> + </tr> +</table> +<div class="manual-text"> +<section class="Sh"> +<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> +<p class="Pp"><code class="Nm">ng_async</code> — + <span class="Nd">asynchronous framing netgraph node type</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> +<p class="Pp"><code class="In">#include + <<a class="In">sys/types.h</a>></code> + <br/> + <code class="In">#include + <<a class="In">netgraph/ng_async.h</a>></code></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp">The <code class="Nm">async</code> node type performs conversion + between synchronous frames and asynchronous frames, as defined for the PPP + protocol in RFC 1662. Asynchronous framing uses flag bytes and + octet-stuffing to simulate a frame oriented connection over an + octet-oriented asynchronous serial line.</p> +<p class="Pp">The node transmits and receives asynchronous data on the + <code class="Dv">async</code> hook. Mbuf boundaries of incoming data are + ignored. Once a complete packet has been received, it is decoded and + stripped of all framing bytes, and transmitted out the + <code class="Dv">sync</code> hook as a single frame.</p> +<p class="Pp">Synchronous frames are transmitted and received on the + <code class="Dv">sync</code> hook. Packets received on this hook are encoded + as asynchronous frames and sent out on <code class="Dv">async</code>. + Received packets should start with the address and control fields, or the + PPP protocol field if address and control field compression is employed, and + contain no checksum field. If the first four bytes are <code class="Dv">0xff + 0x03 0xc0 0x21</code> (an LCP protocol frame) then complete control + character escaping is enabled for that frame (in PPP, LCP packets are always + sent with no address and control field compression and all control + characters escaped).</p> +<p class="Pp">This node supports “flag sharing” for packets + transmitted on <code class="Dv">async</code>. This is an optimization where + the trailing flag byte of one frame is shared with the opening flag byte of + the next. Flag sharing between frames is disabled after one second of + transmit idle time.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HOOKS"><a class="permalink" href="#HOOKS">HOOKS</a></h1> +<p class="Pp">This node type supports the following hooks:</p> +<dl class="Bl-tag"> + <dt id="async"><var class="Va">async</var></dt> + <dd>Asynchronous connection. Typically this hook would be connected to a + <a class="Xr">ng_tty(4)</a> node, which handles transmission of serial + data over a tty device.</dd> + <dt id="sync"><var class="Va">sync</var></dt> + <dd>Synchronous connection. This hook sends and receives synchronous frames. + For PPP, these frames should contain address, control, and protocol + fields, but no checksum field. Typically this hook would be connected to + an individual link hook of a <a class="Xr">ng_ppp(4)</a> type node.</dd> +</dl> +</section> +<section class="Sh"> +<h1 class="Sh" id="CONTROL_MESSAGES"><a class="permalink" href="#CONTROL_MESSAGES">CONTROL + MESSAGES</a></h1> +<p class="Pp">This node type supports the generic control messages, plus the + following:</p> +<dl class="Bl-tag"> + <dt id="NGM_ASYNC_CMD_SET_CONFIG"><a class="permalink" href="#NGM_ASYNC_CMD_SET_CONFIG"><code class="Dv">NGM_ASYNC_CMD_SET_CONFIG</code></a> + (<code class="Ic">setconfig</code>)</dt> + <dd>Sets the node configuration, which is described by a + <code class="Dv">struct ng_async_cfg</code>: + <div class="Bd Pp Bd-indent Li"> + <pre>struct ng_async_cfg { + u_char enabled; /* Turn encoding on/off */ + uint16_t amru; /* Max receive async frame length */ + uint16_t smru; /* Max receive sync frame length */ + uint32_t accm; /* ACCM encoding */ +};</pre> + </div> + The <code class="Dv">enabled</code> field enables or disables all + encoding/decoding functions (default disabled). When disabled, the node + operates in simple “pass through” mode. The + <code class="Dv">amru</code> and <code class="Dv">smru</code> fields are + the asynchronous and synchronous MRU (maximum receive unit) values, + respectively. These both default to 1600; note that the async MRU applies + to the incoming frame length after asynchronous decoding. The + <code class="Dv">accm</code> field is the asynchronous character control + map, which controls the escaping of characters 0x00 thorough 0x1f (default + 0xffffffff).</dd> + <dt id="NGM_ASYNC_CMD_GET_CONFIG"><a class="permalink" href="#NGM_ASYNC_CMD_GET_CONFIG"><code class="Dv">NGM_ASYNC_CMD_GET_CONFIG</code></a> + (<code class="Ic">getconfig</code>)</dt> + <dd>This command returns the current configuration structure.</dd> + <dt id="NGM_ASYNC_CMD_GET_STATS"><a class="permalink" href="#NGM_ASYNC_CMD_GET_STATS"><code class="Dv">NGM_ASYNC_CMD_GET_STATS</code></a> + (<code class="Ic">getstats</code>)</dt> + <dd>This command returns a <code class="Dv">struct ng_async_stat</code> + containing node statistics for packet, octet, and error counts.</dd> + <dt id="NGM_ASYNC_CMD_CLR_STATS"><a class="permalink" href="#NGM_ASYNC_CMD_CLR_STATS"><code class="Dv">NGM_ASYNC_CMD_CLR_STATS</code></a> + (<code class="Ic">clrstats</code>)</dt> + <dd>Clears the node statistics.</dd> +</dl> +</section> +<section class="Sh"> +<h1 class="Sh" id="SHUTDOWN"><a class="permalink" href="#SHUTDOWN">SHUTDOWN</a></h1> +<p class="Pp">This node shuts down upon receipt of a + <code class="Dv">NGM_SHUTDOWN</code> control message, or when all hooks have + been disconnected.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE + ALSO</a></h1> +<p class="Pp"><a class="Xr">netgraph(4)</a>, <a class="Xr">ng_ppp(4)</a>, + <a class="Xr">ng_tty(4)</a>, <a class="Xr">ngctl(8)</a></p> +<p class="Pp"><cite class="Rs"><span class="RsA">W. Simpson</span>, + <span class="RsT">PPP in HDLC-link Framing</span>, <span class="RsO">RFC + 1662</span>.</cite></p> +<p class="Pp"><cite class="Rs"><span class="RsA">W. Simpson</span>, + <span class="RsT">The Point-to-Point Protocol (PPP)</span>, + <span class="RsO">RFC 1661</span>.</cite></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1> +<p class="Pp">The <code class="Nm">ng_async</code> node type was implemented in + <span class="Ux">FreeBSD 4.0</span>.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1> +<p class="Pp"><span class="An">Archie Cobbs</span> + <<a class="Mt" href="mailto:archie@FreeBSD.org">archie@FreeBSD.org</a>></p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">November 13, 2012</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |