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freebsd/usr.bin/netstat/netstat.1
Bosko Milekic 099a0e588c Bring in mbuma to replace mballoc.
mbuma is an Mbuf & Cluster allocator built on top of a number of
extensions to the UMA framework, all included herein.

Extensions to UMA worth noting:
  - Better layering between slab <-> zone caches; introduce
    Keg structure which splits off slab cache away from the
    zone structure and allows multiple zones to be stacked
    on top of a single Keg (single type of slab cache);
    perhaps we should look into defining a subset API on
    top of the Keg for special use by malloc(9),
    for example.
  - UMA_ZONE_REFCNT zones can now be added, and reference
    counters automagically allocated for them within the end
    of the associated slab structures.  uma_find_refcnt()
    does a kextract to fetch the slab struct reference from
    the underlying page, and lookup the corresponding refcnt.

mbuma things worth noting:
  - integrates mbuf & cluster allocations with extended UMA
    and provides caches for commonly-allocated items; defines
    several zones (two primary, one secondary) and two kegs.
  - change up certain code paths that always used to do:
    m_get() + m_clget() to instead just use m_getcl() and
    try to take advantage of the newly defined secondary
    Packet zone.
  - netstat(1) and systat(1) quickly hacked up to do basic
    stat reporting but additional stats work needs to be
    done once some other details within UMA have been taken
    care of and it becomes clearer to how stats will work
    within the modified framework.

From the user perspective, one implication is that the
NMBCLUSTERS compile-time option is no longer used.  The
maximum number of clusters is still capped off according
to maxusers, but it can be made unlimited by setting
the kern.ipc.nmbclusters boot-time tunable to zero.
Work should be done to write an appropriate sysctl
handler allowing dynamic tuning of kern.ipc.nmbclusters
at runtime.

Additional things worth noting/known issues (READ):
   - One report of 'ips' (ServeRAID) driver acting really
     slow in conjunction with mbuma.  Need more data.
     Latest report is that ips is equally sucking with
     and without mbuma.
   - Giant leak in NFS code sometimes occurs, can't
     reproduce but currently analyzing; brueffer is
     able to reproduce but THIS IS NOT an mbuma-specific
     problem and currently occurs even WITHOUT mbuma.
   - Issues in network locking: there is at least one
     code path in the rip code where one or more locks
     are acquired and we end up in m_prepend() with
     M_WAITOK, which causes WITNESS to whine from within
     UMA.  Current temporary solution: force all UMA
     allocations to be M_NOWAIT from within UMA for now
     to avoid deadlocks unless WITNESS is defined and we
     can determine with certainty that we're not holding
     any locks when we're M_WAITOK.
   - I've seen at least one weird socketbuffer empty-but-
     mbuf-still-attached panic.  I don't believe this
     to be related to mbuma but please keep your eyes
     open, turn on debugging, and capture crash dumps.

This change removes more code than it adds.

A paper is available detailing the change and considering
various performance issues, it was presented at BSDCan2004:
http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf
Please read the paper for Future Work and implementation
details, as well as credits.

Testing and Debugging:
    rwatson,
    brueffer,
    Ketrien I. Saihr-Kesenchedra,
    ...
Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00

442 lines
12 KiB
Groff

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.\" @(#)netstat.1 8.8 (Berkeley) 4/18/94
.\" $FreeBSD$
.\"
.Dd March 25, 2004
.Dt NETSTAT 1
.Os
.Sh NAME
.Nm netstat
.Nd show network status
.Sh DESCRIPTION
The
.Nm
command symbolically displays the contents of various network-related
data structures.
There are a number of output formats,
depending on the options for the information presented.
.Bl -tag -width indent
.It Xo
.Bk -words
.Nm
.Op Fl AaLnSW
.Op Fl f Ar protocol_family | Fl p Ar protocol
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Display a list of active sockets
(protocol control blocks)
for each network protocol,
for a particular
.Ar protocol_family ,
or for a single
.Ar protocol .
If
.Fl A
is also present,
show the address of a protocol control block (PCB)
associated with a socket; used for debugging.
If
.Fl a
is also present,
show the state of all sockets;
normally sockets used by server processes are not shown.
If
.Fl L
is also present,
show the size of the various listen queues.
The first count shows the number of unaccepted connections,
the second count shows the amount of unaccepted incomplete connections,
and the third count is the maximum number of queued connections.
If
.Fl S
is also present,
show network addresses as numbers (as with
.Fl n )
but show ports symbolically.
.It Xo
.Bk -words
.Nm
.Fl i | I Ar interface
.Op Fl abdnt
.Op Fl f Ar address_family
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Show the state of all network interfaces or a single
.Ar interface
which have been auto-configured
(interfaces statically configured into a system, but not
located at boot time are not shown).
An asterisk
.Pq Dq Li *
after an interface name indicates that the interface is
.Dq down .
If
.Fl a
is also present, multicast addresses currently in use are shown
for each Ethernet interface and for each IP interface address.
Multicast addresses are shown on separate lines following the interface
address with which they are associated.
If
.Fl b
is also present, show the number of bytes in and out.
If
.Fl d
is also present, show the number of dropped packets.
If
.Fl t
is also present, show the contents of watchdog timers.
If
.Fl W
is also present, print interface names using a wider field size.
.It Xo
.Bk -words
.Nm
.Fl w Ar wait
.Op Fl I Ar interface
.Op Fl d
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
At intervals of
.Ar wait
seconds,
display the information regarding packet
traffic on all configured network interfaces
or a single
.Ar interface .
If
.Fl d
is also present, show the number of dropped packets.
.It Xo
.Bk -words
.Nm
.Fl s Op Fl s
.Op Fl z
.Op Fl f Ar protocol_family | Fl p Ar protocol
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Display system-wide statistics for each network protocol,
for a particular
.Ar protocol_family ,
or for a single
.Ar protocol .
If
.Fl s
is repeated, counters with a value of zero are suppressed.
If
.Fl z
is also present, reset statistic counters after displaying them.
.It Xo
.Bk -words
.Nm
.Fl i | I Ar interface Fl s
.Op Fl f Ar protocol_family | Fl p Ar protocol
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Display per-interface statistics for each network protocol,
for a particular
.Ar protocol_family ,
or for a single
.Ar protocol .
.It Xo
.Bk -words
.Nm
.Fl m
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Show statistics recorded by the memory management routines
.Pq Xr mbuf 9 .
The network manages a private pool of memory buffers.
.It Xo
.Bk -words
.Nm
.Fl r
.Op Fl AanW
.Op Fl f Ar address_family
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Display the contents of all routing tables,
or a routing table for a particular
.Ar address_family .
If
.Fl A
is also present,
show the contents of the internal Patricia tree
structures; used for debugging.
If
.Fl a
is also present,
show protocol-cloned routes
(routes generated by an
.Dv RTF_PRCLONING
parent route);
normally these routes are not shown.
When
.Fl W
is also present,
show the path MTU
for each route,
and print interface
names with a wider
field size.
.It Xo
.Bk -words
.Nm
.Fl rs
.Op Fl s
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Display routing statistics.
If
.Fl s
is repeated, counters with a value of zero are suppressed.
.It Xo
.Bk -words
.Nm
.Fl g
.Op Fl W
.Op Fl f Ar address_family
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Show information related to multicast (group address) routing.
By default, show the IP Multicast virtual-interface and routing tables,
and multicast group memberships.
.It Xo
.Bk -words
.Nm
.Fl gs
.Op Fl s
.Op Fl f Ar address_family
.Op Fl M Ar core
.Op Fl N Ar system
.Ek
.Xc
Show multicast routing statistics.
If
.Fl s
is repeated, counters with a value of zero are suppressed.
.El
.Pp
Some options have the general meaning:
.Bl -tag -width flag
.It Fl f Ar address_family , Fl p Ar protocol
Limit display to those records
of the specified
.Ar address_family
or a single
.Ar protocol .
The following address families and protocols are recognized:
.Pp
.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
.It Em Family
.Em Protocols
.It Cm inet Pq Dv AF_INET
.Cm bdg , divert , icmp , igmp , ip , ipsec , pim, tcp , udp
.It Cm inet6 Pq Dv AF_INET6
.Cm bdg , icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
.It Cm pfkey Pq Dv PF_KEY
.Cm pfkey
.It Cm atalk Pq Dv AF_APPLETALK
.Cm ddp
.It Cm netgraph , ng Pq Dv AF_NETGRAPH
.Cm ctrl , data
.It Cm ipx Pq Dv AF_IPX
.Cm ipx , spx
.\".It Cm ns Pq Dv AF_NS
.\".Cm idp , ns_err , spp
.\".It Cm iso Pq Dv AF_ISO
.\".Cm clnp , cltp , esis , tp
.It Cm unix Pq Dv AF_UNIX
.It Cm link Pq Dv AF_LINK
.El
.Pp
The program will complain if
.Ar protocol
is unknown or if there is no statistics routine for it.
.It Fl M
Extract values associated with the name list from the specified core
instead of the default
.Pa /dev/kmem .
.It Fl N
Extract the name list from the specified system instead of the default,
which is the kernel image the system has booted from.
.It Fl n
Show network addresses and ports as numbers.
Normally
.Nm
attempts to resolve addresses and ports,
and display them symbolically.
.It Fl W
In certain displays, avoid truncating addresses even if this causes
some fields to overflow.
.El
.Pp
The default display, for active sockets, shows the local
and remote addresses, send and receive queue sizes (in bytes), protocol,
and the internal state of the protocol.
Address formats are of the form
.Dq host.port
or
.Dq network.port
if a socket's address specifies a network but no specific host address.
When known, the host and network addresses are displayed symbolically
according to the databases
.Xr hosts 5
and
.Xr networks 5 ,
respectively.
If a symbolic name for an address is unknown, or if
the
.Fl n
option is specified, the address is printed numerically, according
to the address family.
For more information regarding
the Internet IPv4
.Dq dot format ,
refer to
.Xr inet 3 .
Unspecified,
or
.Dq wildcard ,
addresses and ports appear as
.Dq Li * .
.Pp
The interface display provides a table of cumulative
statistics regarding packets transferred, errors, and collisions.
The network addresses of the interface
and the maximum transmission unit
.Pq Dq mtu
are also displayed.
.Pp
The routing table display indicates the available routes and their status.
Each route consists of a destination host or network, and a gateway to use
in forwarding packets.
The flags field shows a collection of information about the route stored
as binary choices.
The individual flags are discussed in more detail in the
.Xr route 8
and
.Xr route 4
manual pages.
The mapping between letters and flags is:
.Bl -column ".Li W" ".Dv RTF_WASCLONED"
.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
.It Li S Ta Dv RTF_STATIC Ta "Manually added"
.It Li U Ta Dv RTF_UP Ta "Route usable"
.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
.El
.Pp
Direct routes are created for each
interface attached to the local host;
the gateway field for such entries shows the address of the outgoing interface.
The refcnt field gives the
current number of active uses of the route.
Connection oriented
protocols normally hold on to a single route for the duration of
a connection while connectionless protocols obtain a route while sending
to the same destination.
The use field provides a count of the number of packets
sent using that route.
The interface entry indicates the network interface utilized for the route.
.Pp
When
.Nm
is invoked with the
.Fl w
option and a
.Ar wait
interval argument, it displays a running count of statistics related to
network interfaces.
An obsolescent version of this option used a numeric parameter
with no option, and is currently supported for backward compatibility.
By default, this display summarizes information for all interfaces.
Information for a specific interface may be displayed with the
.Fl I
option.
.Sh SEE ALSO
.Xr fstat 1 ,
.Xr nfsstat 1 ,
.Xr ps 1 ,
.Xr sockstat 1 ,
.Xr inet 4 ,
.Xr route 4 ,
.Xr unix 4 ,
.Xr hosts 5 ,
.Xr networks 5 ,
.Xr protocols 5 ,
.Xr services 5 ,
.Xr iostat 8 ,
.Xr route 8 ,
.Xr trpt 8 ,
.Xr vmstat 8 ,
.Xr mbuf 9
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .
.Pp
IPv6 support was added by WIDE/KAME project.
.Sh BUGS
The notion of errors is ill-defined.