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diff --git a/static/netbsd/man4/tap.4 3.html b/static/netbsd/man4/tap.4 3.html deleted file mode 100644 index 544b5ee3..00000000 --- a/static/netbsd/man4/tap.4 3.html +++ /dev/null @@ -1,138 +0,0 @@ -<table class="head"> - <tr> - <td class="head-ltitle">TAP(4)</td> - <td class="head-vol">Device Drivers Manual</td> - <td class="head-rtitle">TAP(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">tap</code> — <span class="Nd">Ethernet - tunnel software network interface</span></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> -<p class="Pp"><code class="Cd">pseudo-device tap</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">tap</code> driver allows the creation and use - of virtual Ethernet devices. Those interfaces appear just as any real - Ethernet NIC to the kernel, but can also be accessed by userland through a - character device node in order to read frames being sent by the system or to - inject frames. In that respect it is very similar to what - <a class="Xr">tun(4)</a> provides.</p> -<section class="Ss"> -<h2 class="Ss" id="INTERFACE_CREATION"><a class="permalink" href="#INTERFACE_CREATION">INTERFACE - CREATION</a></h2> -<p class="Pp">Interfaces may be created in two different ways: using the - <a class="Xr">ifconfig(8)</a> <code class="Cm">create</code> command with a - specified device number, or its <a class="Xr">ioctl(2)</a> equivalent, - <code class="Dv">SIOCIFCREATE</code>, or using the special cloning device - <span class="Pa">/dev/tap</span>.</p> -<p class="Pp">The former works the same as any other cloning network interface: - the administrator can create and destroy interfaces at any time, notably at - boot time. This is the easiest way of combining <code class="Nm">tap</code> - and <a class="Xr">bridge(4)</a>. Later, userland will actually access the - interfaces through the specific device nodes - <span class="Pa">/dev/tapN</span>.</p> -<p class="Pp">The latter is aimed at applications that need a virtual Ethernet - device for the duration of their execution. A new interface is created at - the opening of <span class="Pa">/dev/tap</span>, and is later destroyed when - the last process using the file descriptor closes it.</p> -</section> -<section class="Ss"> -<h2 class="Ss" id="CHARACTER_DEVICES"><a class="permalink" href="#CHARACTER_DEVICES">CHARACTER - DEVICES</a></h2> -<p class="Pp">Whether the <code class="Nm">tap</code> devices are accessed - through the special cloning device <span class="Pa">/dev/tap</span> or - through the specific devices <span class="Pa">/dev/tapN</span>, the possible - actions to control the matching interface are the same.</p> -<p class="Pp">When using <span class="Pa">/dev/tap</span> though, as the - interface is created on-the-fly, its name is not known immediately by the - application. Therefore the <code class="Dv">TAPGIFNAME</code> ioctl is - provided. It should be the first action an application using the special - cloning device will do. It takes a pointer to a <var class="Ft">struct - ifreq</var> as an argument.</p> -<p class="Pp">Ethernet frames sent out by the kernel on a - <code class="Nm">tap</code> interface can be obtained by the controlling - application with <a class="Xr">read(2)</a>. It can also inject frames in the - kernel with <a class="Xr">write(2)</a>. There is absolutely no validation of - the content of the injected frame, it can be any data, of any length.</p> -<p class="Pp">One call of <a class="Xr">write(2)</a> will inject a single frame - in the kernel, as one call of <a class="Xr">read(2)</a> will retrieve a - single frame from the queue, to the extent of the provided buffer. If the - buffer is not large enough, the frame will be truncated.</p> -<p class="Pp"><code class="Nm">tap</code> character devices support the - <code class="Dv">FIONREAD</code> ioctl which returns the size of the next - available frame, or 0 if there is no available frame in the queue.</p> -<p class="Pp">They also support non-blocking I/O through the - <code class="Dv">FIONBIO</code> ioctl. In that mode, - <code class="Er">EWOULDBLOCK</code> is returned by <a class="Xr">read(2)</a> - when no data is available.</p> -<p class="Pp">Asynchronous I/O is supported through the - <code class="Dv">FIOASYNC</code>, <code class="Dv">FIOSETOWN</code>, and - <code class="Dv">FIOGETOWN</code> ioctls. The first will enable - <code class="Dv">SIGIO</code> generation, while the two other configure the - process group that will receive the signal when data is ready.</p> -<p class="Pp">Synchronisation may also be achieved through the use of - <a class="Xr">select(2)</a>, <a class="Xr">poll(2)</a>, or - <a class="Xr">kevent(2)</a>.</p> -</section> -<section class="Ss"> -<h2 class="Ss" id="ETHERNET_ADDRESS"><a class="permalink" href="#ETHERNET_ADDRESS">ETHERNET - ADDRESS</a></h2> -<p class="Pp">When a <code class="Nm">tap</code> device is created, it is - assigned an Ethernet address of the form f2:0b:a4:xx:xx:xx. This address can - later be changed using <a class="Xr">ifconfig(8)</a> to add an active link - layer address, or directly via the <code class="Dv">SIOCALIFADDR</code> - ioctl on a <code class="Dv">PF_LINK</code> socket, as it is not available on - the ioctl handler of the character device interface.</p> -</section> -<section class="Ss"> -<h2 class="Ss" id="LINK_STATE"><a class="permalink" href="#LINK_STATE">LINK - STATE</a></h2> -<p class="Pp">When an application has opened the <code class="Nm">tap</code> - character device the link is considered up, otherwise down. As such, it is - best to open the character device once connectivity has been established so - that Duplicate Address Detection, if applicable, can be performed. If - connectivity is lost, the character device should be closed.</p> -</section> -</section> -<section class="Sh"> -<h1 class="Sh" id="FILES"><a class="permalink" href="#FILES">FILES</a></h1> -<dl class="Bl-tag Bl-compact"> - <dt><span class="Pa">/dev/tap</span></dt> - <dd>cloning device</dd> - <dt><span class="Pa">/dev/tap[0-9]*</span></dt> - <dd>individual character device nodes</dd> -</dl> -</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">bridge(4)</a>, <a class="Xr">l2tp(4)</a>, - <a class="Xr">tun(4)</a>, <a class="Xr">vether(4)</a>, - <a class="Xr">ifconfig(8)</a></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">tap</code> driver first appeared in - <span class="Ux">NetBSD 3.0</span>.</p> -</section> -<section class="Sh"> -<h1 class="Sh" id="CAVEATS"><a class="permalink" href="#CAVEATS">CAVEATS</a></h1> -<p class="Pp">Starting from <span class="Ux">NetBSD 10.0</span>, the - <code class="Nm">tap</code> driver can no longer be used as a - <a class="Xr">bridge(4)</a> endpoint because it supports a link state based - on if it has been opened or not. Use the <a class="Xr">vether(4)</a> driver - instead as it's been explicitly designed for this purpose.</p> -</section> -</div> -<table class="foot"> - <tr> - <td class="foot-date">May 2, 2022</td> - <td class="foot-os">NetBSD 10.1</td> - </tr> -</table> |