freebsd-skq/usr.bin/sockstat/sockstat.1
Michael Tuexen 9e644c2300 tcp: add support for TCP over UDP
Adding support for TCP over UDP allows communication with
TCP stacks which can be implemented in userspace without
requiring special priviledges or specific support by the OS.
This is joint work with rrs.

Reviewed by:		rrs
Sponsored by:		Netflix, Inc.
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D29469
2021-04-18 16:16:42 +02:00

223 lines
5.7 KiB
Groff

.\"-
.\" Copyright (c) 1999 Dag-Erling Coïdan Smørgrav
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.\" $FreeBSD$
.\"
.Dd March 28, 2021
.Dt SOCKSTAT 1
.Os
.Sh NAME
.Nm sockstat
.Nd list open sockets
.Sh SYNOPSIS
.Nm
.Op Fl 46CcLlnSsUuvw
.Op Fl j Ar jid
.Op Fl p Ar ports
.Op Fl P Ar protocols
.Sh DESCRIPTION
The
.Nm
command lists open Internet or
.Ux
domain sockets.
.Pp
The following options are available:
.Bl -tag -width Fl
.It Fl 4
Show
.Dv AF_INET
(IPv4) sockets.
.It Fl 6
Show
.Dv AF_INET6
(IPv6) sockets.
.It Fl C
Display the congestion control module, if applicable.
This is currently only implemented for TCP.
.It Fl c
Show connected sockets.
.It Fl j Ar jail
Show only sockets belonging to the specified jail ID or name.
.It Fl L
Only show Internet sockets if the local and foreign addresses are not
in the loopback network prefix
.Li 127.0.0.0/8 ,
or do not contain the IPv6 loopback address
.Li ::1 .
.It Fl l
Show listening sockets.
.It Fl n
Do not resolve numeric UIDs to user names.
.It Fl p Ar ports
Only show Internet sockets if the local or foreign port number
is on the specified list.
The
.Ar ports
argument is a comma-separated list of port numbers and ranges
specified as first and last port separated by a dash.
.It Fl P Ar protocols
Only show sockets of the specified
.Ar protocols .
The
.Ar protocols
argument is a comma-separated list of protocol names,
as they are defined in
.Xr protocols 5 .
.It Fl q
Quiet mode, do not print the header line.
.It Fl S
Display the protocol stack, if applicable.
This is currently only implemented for TCP.
.It Fl s
Display the protocol state, if applicable.
This is currently only implemented for SCTP and TCP.
.It Fl U
Display the remote UDP encapsulation port number, if applicable.
This is currently only implemented for SCTP and TCP.
.It Fl u
Show
.Dv AF_LOCAL
.Pq Ux
sockets.
.It Fl v
Verbose mode.
.It Fl w
Use wider field size for displaying addresses.
.El
.Pp
If neither
.Fl 4 , 6
or
.Fl u
is specified,
.Nm
will list sockets in all three domains.
.Pp
If neither
.Fl c
or
.Fl l
is specified,
.Nm
will list both listening and connected sockets.
.Pp
The information listed for each
socket is:
.Bl -tag -width "FOREIGN ADDRESS"
.It Li USER
The user who owns the socket.
.It Li COMMAND
The command which holds the socket.
.It Li PID
The process ID of the command which holds the socket.
.It Li FD
The file descriptor number of the socket.
.It Li PROTO
The transport protocol associated with the socket for Internet
sockets, or the type of socket
.Pq stream, datagram, or seqpacket
for
.Ux
sockets.
.It Li LOCAL ADDRESS
For Internet sockets, this is the address the local end of the socket
is bound to (see
.Xr getsockname 2 ) .
For bound
.Ux
sockets, it is the socket's filename.
For other
.Ux
sockets, it is a right arrow followed by the endpoint's filename, or
.Dq Li ??
if the endpoint could not be determined.
.It Li FOREIGN ADDRESS
(Internet sockets only)
The address the foreign end of the socket is bound to (see
.Xr getpeername 2 ) .
.It Li ENCAPS
The remote UDP encapsulation port number if
.Fl U
is specified (only for SCTP or TCP).
.It Li PATH STATE
The path state if
.Fl s
is specified (only for SCTP).
.It Li CONN STATE
The connection state if
.Fl s
is specified (only for SCTP or TCP).
.It Li STACK
The protocol stack if
.Fl S
is specified (only for TCP).
.It Li CC
The congestion control if
.Fl C
is specified (only for TCP).
.El
.Pp
If a socket is associated with more than one file descriptor,
it is shown multiple times.
If a socket is not associated with any file descriptor,
the first four columns have no meaning.
.Sh EXAMPLES
Show information for IPv4 sockets listening on port 22 using protocol
TCP:
.Bd -literal -offset indent
$ sockstat -4 -l -P tcp -p 22
.Ed
.Pp
Show information for sockets using either TCP or UDP, if neither, the local nor
the foreign addresses are in the loopback network:
.Bd -literal -offset indent
$ sockstat -L -P tcp,udp
.Ed
.Pp
Show TCP IPv6 sockets which are listening and connected (default):
.Bd -literal -offset indent
$ sockstat -6 -P tcp
.Ed
.Sh SEE ALSO
.Xr fstat 1 ,
.Xr netstat 1 ,
.Xr procstat 1 ,
.Xr inet 4 ,
.Xr inet6 4 ,
.Xr protocols 5
.Sh HISTORY
The
.Nm
command appeared in
.Fx 3.1 .
.Sh AUTHORS
The
.Nm
command and this manual page were written by
.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org .