xref: /freebsd/share/man/man4/ng_ksocket.4 (revision eddc45e797c4582384a29504a26f4ef02b23a946)
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33.\" Author: Archie Cobbs <archie@FreeBSD.org>
34.\"
35.\" $FreeBSD$
36.\"
37.Dd November 15, 1999
38.Dt NG_KSOCKET 4
39.Os FreeBSD
40.Sh NAME
41.Nm ng_ksocket
42.Nd kernel socket netgraph node type
43.Sh SYNOPSIS
44.Fd #include <netgraph/ng_ksocket.h>
45.Sh DESCRIPTION
46A
47.Nm ksocket
48node is both a netgraph node and a BSD socket.  The
49.Nm
50node type allows one to open a socket inside the kernel and have
51it appear as a Netgraph node.  The
52.Nm
53node type is the reverse of the socket node type (see
54.Xr ng_socket 4 ) :
55whereas the socket node type enables the user-level manipulation (via
56a socket) of what is normally a kernel-level entity (the associated
57Netgraph node), the
58.Nm
59node type enables the kernel-level manipulation (via a Netgraph node) of
60what is normally a user-level entity (the associated socket).
61.Pp
62A
63.Nm
64node allows at most one hook connection.  Connecting to the node is
65equivalent to opening the associated socket.  The name given to the hook
66determines what kind of socket the node will open (see below).
67When the hook is disconnected and/or the node is shutdown, the
68associated socket is closed.
69.Sh HOOKS
70This node type supports a single hook connection at a time.
71The name of the hook must be of the form
72.Dv Em <family>/<type>/<proto> ,
73where the
74.Dv Em family ,
75.Dv Em type ,
76and
77.Dv Em proto
78are the decimal equivalent of the same arguments to
79.Xr socket 2 .
80Alternately, aliases for the commonly used values are accepted as
81well.  For example
82.Dv inet/dgram/udp
83is a more readable but equivalent version of
84.Dv 2/2/17 .
85.Sh CONTROL MESSAGES
86This node type supports the generic control messages, plus the following:
87.Bl -tag -width foo
88.It Dv NGM_KSOCKET_BIND
89This functions exactly like the
90.Xr bind 2
91system call.  The
92.Dv "struct sockaddr"
93socket address parameter should be supplied as an argument.
94.It Dv NGM_KSOCKET_LISTEN
95This functions exactly like the
96.Xr listen 2
97system call.  The backlog paramter (a single 32 bit
98.Dv int )
99should be supplied as an argument.
100.It Dv NGM_KSOCKET_CONNECT
101This functions exactly like the
102.Xr connect 2
103system call.  The
104.Dv "struct sockaddr"
105destination address parameter should be supplied as an argument.
106.It Dv NGM_KSOCKET_ACCEPT
107Currently unimplemented.
108.It Dv NGM_KSOCKET_GETNAME
109Equivalent to the
110.Xr getname 2
111system call.  The name is returned as a
112.Dv "struct sockaddr"
113in the arguments field of the reply.
114.It Dv NGM_KSOCKET_GETPEERNAME
115Equivalent to the
116.Xr getpeername 2
117system call.  The name is returned as a
118.Dv "struct sockaddr"
119in the arguments field of the reply.
120.It Dv NGM_KSOCKET_SETOPT
121Equivalent to the
122.Xr setsockopt 2
123system call, except that the option name, level, and value are passed in a
124.Dv "struct ng_ksocket_sockopt" .
125.It Dv NGM_KSOCKET_GETOPT
126Equivalent to the
127.Xr getsockopt 2
128system call, except that the option is passed in a
129.Dv "struct ng_ksocket_sockopt" .
130When sending this command, the
131.Dv value
132field should be empty; upon return, it will contain the
133retrieved value.
134.El
135.Pp
136.Sh ASCII FORM CONTROL MESSAGES
137For control messages that pass a
138.Dv "struct sockaddr"
139in the argument field, the normal
140.Tn ASCII
141equivalent of the C structure
142is an acceptable form.  For the
143.Dv PF_INET
144and
145.Dv PF_LOCAL
146address families, a more convenient form is also used, which is
147the protocol family name, followed by a slash, followed by the actual
148address.  For
149.Dv PF_INET ,
150the address is an IP address followed by an optional colon and port number.
151For
152.Dv PF_LOCAL ,
153the address is the pathname as a doubly quoted string.
154.Pp
155Examples:
156.Bl -tag -width XXXXXXXXXX
157.It Dv PF_LOCAL
158local/"/tmp/foo.socket"
159.It Dv PF_INET
160inet/192.168.1.1:1234
161.It Other
162.Dv "\&{ family=16 len=16 data=[0x70 0x00 0x01 0x23] \&}"
163.El
164.Pp
165For control messages that pass a
166.Dv "struct ng_ksocket_sockopt" ,
167the normal
168.Tn ASCII
169form for that structure is used.  In the future, more
170convenient encoding of the more common socket options may be supported.
171.Sh SHUTDOWN
172This node shuts down upon receipt of a
173.Dv NGM_SHUTDOWN
174control message, or when the hook is disconnected.
175Shutdown of the node closes the associated socket.
176.Sh SEE ALSO
177.Xr socket 2 ,
178.Xr netgraph 4 ,
179.Xr ng_socket 4 ,
180.Xr ngctl 8
181.Sh HISTORY
182The
183.Nm
184node type was implemented in
185.Fx 4.0 .
186.Sh AUTHORS
187.An Archie Cobbs Aq archie@FreeBSD.org
188