xref: /freebsd/share/man/man4/ng_gif.4 (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
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27.\" Author: Brooks Davis <brooks@FreeBSD.org>
28.\"
29.\" $FreeBSD$
30.\"
31.Dd September 18, 2001
32.Dt NG_GIF 4
33.Os
34.Sh NAME
35.Nm ng_gif
36.Nd generic tunnel interface netgraph node type
37.Sh SYNOPSIS
38.In netgraph/ng_gif.h
39.Sh DESCRIPTION
40The
41.Nm
42netgraph node type allows
43.Xr gif 4
44interfaces to interact with
45the
46.Xr netgraph 4
47networking subsystem.
48Once the
49.Nm
50module is loaded in the kernel, a node is automatically created
51for each
52.Xr gif 4
53interface in the system.
54Each node will attempt to name itself with the same name
55as the associated interface.
56All
57.Nm
58nodes are persistent for as long as the interface itself exists.
59.Pp
60Two hooks are supported:
61.Dv lower
62and
63.Dv orphans .
64The hook name
65.Dv divert
66may be used as an alias for
67.Dv lower ,
68and is provided for compatibility with
69.Xr ng_ether 4 .
70In reality the two names represent the same hook.
71.Pp
72The
73.Dv lower
74hook is a connection to the raw
75.Xr gif 4
76device.
77When connected, all incoming packets are diverted out this hook.
78Writing to this hook results in a raw encapsulated packet being transmitted
79by the device.
80Normal outgoing packets are not affected by
81.Dv lower
82being connected.
83.Pp
84The
85.Dv orphans
86hook is equivalent to
87.Dv lower ,
88except that only unrecognized packets (that would otherwise be discarded)
89are written to the hook, and normal incoming traffic is unaffected.
90At most one of
91.Dv orphans
92and
93.Dv lower
94may be connected at any time.
95.Pp
96In all cases, frames are raw packets with the address family of the
97packet attached to the front.
98.Pp
99When no hooks are connected, packets flow normally upwards and downwards.
100.Sh HOOKS
101This node type supports the following hooks:
102.Bl -tag -width ".Dv orphans"
103.It Dv lower
104Connection to the lower device link layer.
105.It Dv orphans
106Like
107.Dv lower ,
108but only receives unrecognized packets.
109.El
110.Sh CONTROL MESSAGES
111This node type supports only the generic control messages.
112.Sh EXAMPLES
113This command dumps all unrecognized packets received by the
114.Li gif0
115interface to standard output decoded in hex and ASCII:
116.Pp
117.Dl "nghook -a gif0: orphans"
118.Sh SEE ALSO
119.Xr gif 4 ,
120.Xr netgraph 4 ,
121.Xr netintro 4 ,
122.Xr ifconfig 8 ,
123.Xr ngctl 8 ,
124.Xr nghook 8
125.Sh AUTHORS
126.An Brooks Davis Aq brooks@FreeBSD.org
127