xref: /freebsd/share/man/man4/ng_ksocket.4 (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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33.\" Author: Archie Cobbs <archie@FreeBSD.org>
34.\"
35.\" $FreeBSD$
36.\"
37.Dd June 8, 2004
38.Dt NG_KSOCKET 4
39.Os
40.Sh NAME
41.Nm ng_ksocket
42.Nd kernel socket netgraph node type
43.Sh SYNOPSIS
44.In sys/types.h
45.In netgraph/ng_ksocket.h
46.Sh DESCRIPTION
47A
48.Nm ksocket
49node is both a netgraph node and a
50.Bx
51socket.
52The
53.Nm
54node type allows one to open a socket inside the kernel and have
55it appear as a Netgraph node.
56The
57.Nm
58node type is the reverse of the socket node type (see
59.Xr ng_socket 4 ) :
60whereas the socket node type enables the user-level manipulation (via
61a socket) of what is normally a kernel-level entity (the associated
62Netgraph node), the
63.Nm
64node type enables the kernel-level manipulation (via a Netgraph node) of
65what is normally a user-level entity (the associated socket).
66.Pp
67A
68.Nm
69node allows at most one hook connection.
70Connecting to the node is
71equivalent to opening the associated socket.
72The name given to the hook
73determines what kind of socket the node will open (see below).
74When the hook is disconnected and/or the node is shutdown, the
75associated socket is closed.
76.Sh HOOKS
77This node type supports a single hook connection at a time.
78The name of the hook must be of the form
79.Em <family>/<type>/<proto> ,
80where the
81.Em family ,
82.Em type ,
83and
84.Em proto
85are the decimal equivalent of the same arguments to
86.Xr socket 2 .
87Alternately, aliases for the commonly used values are accepted as
88well.
89For example
90.Dv inet/dgram/udp
91is a more readable but equivalent version of
92.Dv 2/2/17 .
93.Pp
94Data received into socket is sent out via hook.
95Data received on hook is sent out from socket, if the latter is
96connected (an
97.Dv NGM_KSOCKET_CONNECT
98was sent to node before).
99If socket is not connected, destination
100.Vt "struct sockaddr"
101must be supplied in an mbuf tag with cookie
102.Dv NGM_KSOCKET_COOKIE
103and type
104.Dv NG_KSOCKET_TAG_SOCKADDR
105attached to data.
106Otherwise
107.Nm
108will return
109.Er ENOTCONN
110to sender.
111.Sh CONTROL MESSAGES
112This node type supports the generic control messages, plus the following:
113.Bl -tag -width foo
114.It Dv NGM_KSOCKET_BIND
115This functions exactly like the
116.Xr bind 2
117system call.
118The
119.Vt "struct sockaddr"
120socket address parameter should be supplied as an argument.
121.It Dv NGM_KSOCKET_LISTEN
122This functions exactly like the
123.Xr listen 2
124system call.
125The backlog parameter (a single 32 bit
126.Dv int )
127should be supplied as an argument.
128.It Dv NGM_KSOCKET_CONNECT
129This functions exactly like the
130.Xr connect 2
131system call.
132The
133.Vt "struct sockaddr"
134destination address parameter should be supplied as an argument.
135.It Dv NGM_KSOCKET_ACCEPT
136Currently unimplemented.
137.It Dv NGM_KSOCKET_GETNAME
138Equivalent to the
139.Xr getsockname 2
140system call.
141The name is returned as a
142.Vt "struct sockaddr"
143in the arguments field of the reply.
144.It Dv NGM_KSOCKET_GETPEERNAME
145Equivalent to the
146.Xr getpeername 2
147system call.
148The name is returned as a
149.Vt "struct sockaddr"
150in the arguments field of the reply.
151.It Dv NGM_KSOCKET_SETOPT
152Equivalent to the
153.Xr setsockopt 2
154system call, except that the option name, level, and value are passed in a
155.Vt "struct ng_ksocket_sockopt" .
156.It Dv NGM_KSOCKET_GETOPT
157Equivalent to the
158.Xr getsockopt 2
159system call, except that the option is passed in a
160.Vt "struct ng_ksocket_sockopt" .
161When sending this command, the
162.Dv value
163field should be empty; upon return, it will contain the
164retrieved value.
165.El
166.Sh ASCII FORM CONTROL MESSAGES
167For control messages that pass a
168.Vt "struct sockaddr"
169in the argument field, the normal
170.Tn ASCII
171equivalent of the C structure
172is an acceptable form.
173For the
174.Dv PF_INET
175and
176.Dv PF_LOCAL
177address families, a more convenient form is also used, which is
178the protocol family name, followed by a slash, followed by the actual
179address.
180For
181.Dv PF_INET ,
182the address is an IP address followed by an optional colon and port number.
183For
184.Dv PF_LOCAL ,
185the address is the pathname as a doubly quoted string.
186.Pp
187Examples:
188.Bl -tag -width XXXXXXXXXX
189.It Dv PF_LOCAL
190local/"/tmp/foo.socket"
191.It Dv PF_INET
192inet/192.168.1.1:1234
193.It Other
194.Dv "\&{ family=16 len=16 data=[0x70 0x00 0x01 0x23] \&}"
195.El
196.Pp
197For control messages that pass a
198.Vt "struct ng_ksocket_sockopt" ,
199the normal
200.Tn ASCII
201form for that structure is used.
202In the future, more
203convenient encoding of the more common socket options may be supported.
204.Sh SHUTDOWN
205This node shuts down upon receipt of a
206.Dv NGM_SHUTDOWN
207control message, or when the hook is disconnected.
208Shutdown of the node closes the associated socket.
209.Sh SEE ALSO
210.Xr socket 2 ,
211.Xr netgraph 4 ,
212.Xr ng_socket 4 ,
213.Xr ngctl 8 ,
214.Xr mbuf_tags 9
215.Sh HISTORY
216The
217.Nm
218node type was implemented in
219.Fx 4.0 .
220.Sh AUTHORS
221.An Archie Cobbs Aq archie@FreeBSD.org
222