diff options
Diffstat (limited to 'share/man/man4')
| -rw-r--r-- | share/man/man4/tun.4 | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/share/man/man4/tun.4 b/share/man/man4/tun.4 index e2955ec3e65..3246e35ef90 100644 --- a/share/man/man4/tun.4 +++ b/share/man/man4/tun.4 @@ -1,4 +1,4 @@ -.\" $OpenBSD: tun.4,v 1.27 2003/12/08 10:03:43 markus Exp $ +.\" $OpenBSD: tun.4,v 1.28 2004/06/25 04:09:02 claudio Exp $ .\" .\" Copyright (c) 2003 Marcus D. Watts All rights reserved. .\" @@ -53,13 +53,24 @@ interface can be created at runtime using the command or by opening the character special device .Pa /dev/tunN . .Pp +Both layer 3 and layer 2 tunnenling is supported. +Layer 3 tunneling is the default mode, to enable layer 2 tunneling mode the +.Ar link0 +flag needs to be set with +.Xr ifconfig 8 . +In layer 2 mode the +.Nm +interface is simulating an Ethernet network interface. +.Pp Each device has the exclusive open property; it cannot be opened if it is already open and in use by another process. Each read returns at most one packet; if insufficient buffer space is provided, the packet is truncated. Each write supplies exactly one packet. Each packet read or written is prefixed with a tunnel header consisting of -a 4 byte network byte order integer containing the address family. +a 4 byte network byte order integer containing the address family in the case +of layer 3 tunneling. +In layer 2 mode the 4 byte tunnel header is replaced with a Ethernet header. On the last close of the device, all packets are discarded, the device is marked down, and all routes via the device are removed. @@ -120,13 +131,16 @@ Can be used to set non-blocking I/O. Can be used to cause signal .Dv SIGIO to be sent when a packet can be read. -.It Dv TIOCSPGRP Fa int *pgpp +.It Dv TIOCSPGRP Fa int *pgrp .It Dv TIOCGPGRP Fa int *pgrp Get or set the process group to which signals might be sent via .Dv FIOASYNC . .It Dv FIONREAD Fa int *count Gets the byte count of the next packet available to be read. +.It Dv SIOCGIFADDR Fa struct ether_addr *addr +.It Dv SIOCSIFADDR Fa struct ether_addr *addr +Get or set the ethernet address of the device in layer 2 mode. .El .Sh FILES .Bl -tag -width /dev/tun* -compact @@ -164,16 +178,18 @@ recognized. .Pp Ioctl commands may fail with: .Bl -tag -width Er -.It Bq EBUSY -.Dv TUNSIFMODE -and the interface was up. .It Bq EINVAL Attempt to set both .Dv IFF_POINTOPOINT and .Dv IFF_BROADCAST with -.Dv TUNSIFMODE . +.Dv TUNSIFMODE +or using +.Dv SIOCGIFADDR +or +.Dv SIOCSIFADDR +in layer 3 mode. .It Bq ENOTTY Unrecognized ioctl command. .El |