ng_ksocket -- kernel socket netgraph node type
#include <netgraph/ng_ksocket.h>
A ksocket node is both a netgraph node and a BSD socket. The ng_ksocket
node type allows one to open a socket inside the kernel and have it
appear as a Netgraph node. The ng_ksocket node type is the reverse of
the socket node type (see ng_socket(4)): whereas the socket node type
enables the user-level manipulation (via a socket) of what is normally a
kernel-level entity (the associated Netgraph node), the ng_ksocket node
type enables the kernel-level manipulation (via a Netgraph node) of what
is normally a user-level entity (the associated socket).
A ng_ksocket node allows at most one hook connection. Connecting to the
node is equivalent to opening the associated socket. The name given to
the hook determines what kind of socket the node will open (see below).
When the hook is disconnected and/or the node is shutdown, the associated
socket is closed.
This node type supports a single hook connection at a time. The name of
the hook must be of the form <family>/<type>/<proto>, where the family,
type, and proto are the decimal equivalent of the same arguments to
socket(2). Alternately, aliases for the commonly used values are
accepted as well. For example inet/dgram/udp is a more readable but
equivalent version of 2/2/17.
This node type supports the generic control messages, plus the following:
NGM_KSOCKET_BIND
This functions exactly like the bind(2) system call. The struct
sockaddr socket address parameter should be supplied as an argument.
NGM_KSOCKET_LISTEN
This functions exactly like the listen(2) system call. The backlog
parameter (a single 32 bit int) should be supplied as an argument.
NGM_KSOCKET_CONNECT
This functions exactly like the connect(2) system call. The struct
sockaddr destination address parameter should be supplied as an
argument.
NGM_KSOCKET_ACCEPT
Currently unimplemented.
NGM_KSOCKET_GETNAME
Equivalent to the getsockname(2) system call. The name is returned
as a struct sockaddr in the arguments field of the reply.
NGM_KSOCKET_GETPEERNAME
Equivalent to the getpeername(2) system call. The name is returned
as a struct sockaddr in the arguments field of the reply.
NGM_KSOCKET_SETOPT
Equivalent to the setsockopt(2) system call, except that the option
name, level, and value are passed in a struct ng_ksocket_sockopt.
NGM_KSOCKET_GETOPT
Equivalent to the getsockopt(2) system call, except that the option
is passed in a struct ng_ksocket_sockopt. When sending this command,
the value field should be empty; upon return, it will contain
the retrieved value.
ASCII FORM CONTROL MESSAGES [Toc] [Back] For control messages that pass a struct sockaddr in the argument field,
the normal ASCII equivalent of the C structure is an acceptable form.
For the PF_INET and PF_LOCAL address families, a more convenient form is
also used, which is the protocol family name, followed by a slash, followed
by the actual address. For PF_INET, the address is an IP address
followed by an optional colon and port number. For PF_LOCAL, the address
is the pathname as a doubly quoted string.
Examples:
PF_LOCAL local/"/tmp/foo.socket"
PF_INET inet/192.168.1.1:1234
Other { family=16 len=16 data=[0x70 0x00 0x01 0x23] }
For control messages that pass a struct ng_ksocket_sockopt, the normal
ASCII form for that structure is used. In the future, more convenient
encoding of the more common socket options may be supported.
This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
when the hook is disconnected. Shutdown of the node closes the associated
socket.
socket(2), netgraph(4), ng_socket(4), ngctl(8)
The ng_ksocket node type was implemented in FreeBSD 4.0.
Archie Cobbs <[email protected]>
FreeBSD 5.2.1 November 15, 1999 FreeBSD 5.2.1 [ Back ] | 