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diff --git a/share/man/man4/ifmib.4 b/share/man/man4/ifmib.4 new file mode 100644 index 000000000000..3cffbeab1816 --- /dev/null +++ b/share/man/man4/ifmib.4 @@ -0,0 +1,196 @@ +.\" Copyright 1996 Massachusetts Institute of Technology +.\" +.\" Permission to use, copy, modify, and distribute this software and +.\" its documentation for any purpose and without fee is hereby +.\" granted, provided that both the above copyright notice and this +.\" permission notice appear in all copies, that both the above +.\" copyright notice and this permission notice appear in all +.\" supporting documentation, and that the name of M.I.T. not be used +.\" in advertising or publicity pertaining to distribution of the +.\" software without specific, written prior permission. M.I.T. makes +.\" no representations about the suitability of this software for any +.\" purpose. It is provided "as is" without express or implied +.\" warranty. +.\" +.\" THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS +.\" ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, +.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT +.\" SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd November 15, 1996 +.Dt IFMIB 4 +.Os +.Sh NAME +.Nm ifmib +.Nd Management Information Base for network interfaces +.Sh SYNOPSIS +.In sys/types.h +.In sys/socket.h +.In sys/sysctl.h +.In sys/time.h +.In net/if.h +.In net/if_mib.h +.Sh DESCRIPTION +The +.Nm +facility is an application of the +.Xr sysctl 3 +interface to provide management information about network interfaces +to client applications such as +.Xr netstat 1 , +.Xr slstat 8 , +and +.Tn SNMP +management agents. +This information is structured as a table, where +each row in the table represents a logical network interface (either a +hardware device or a software pseudo-device like +.Xr lo 4 ) . +There are two columns in the table, each containing a single +structure: one column contains generic information relevant to all +interfaces, and the other contains information specific to the +particular class of interface. +(Generally the latter will implement +the +.Tn SNMP +.Tn MIB +defined for that particular interface class, if one exists and can be +implemented in the kernel.) +.Pp +The +.Nm +facility is accessed via the +.Dq Li net.link.generic +branch of the +.Xr sysctl 3 +MIB. +The manifest constants for each level in the +.Xr sysctl 3 +.Ar name +are defined in +.In net/if_mib.h . +The index of the last row in the table is given by +.Dq Li net.link.generic.system.ifcount +(or, using the manifest constants, +.Dv CTL_NET , +.Dv PF_LINK , +.Dv NETLINK_GENERIC , +.Dv IFMIB_SYSTEM , +.Dv IFMIB_IFCOUNT ) . +A management application searching for a particular interface should +start with row 1 and continue through the table row-by-row until the +desired interface is found, or the interface count is reached. +Note that the table may be sparse, i.e., a given row may not exist, +indicated by an +.Va errno +of +.Er ENOENT . +Such an error should be ignored, and the next row should be checked. +.Pp +The generic interface information, common to all interfaces, +can be accessed via the following procedure: +.Bd -literal -offset indent +int +get_ifmib_general(int row, struct ifmibdata *ifmd) +{ + int name[6]; + size_t len; + + name[0] = CTL_NET; + name[1] = PF_LINK; + name[2] = NETLINK_GENERIC; + name[3] = IFMIB_IFDATA; + name[4] = row; + name[5] = IFDATA_GENERAL; + + len = sizeof(*ifmd); + + return sysctl(name, 6, ifmd, &len, (void *)0, 0); +} +.Ed +.Pp +The fields in +.Li struct ifmibdata +are as follows: +.Bl -tag -width "ifmd_snd_drops" +.It Li ifmd_name +.Pq Li "char []" +the name of the interface, including the unit number +.It Li ifmd_pcount +.Pq Li int +the number of promiscuous listeners +.It Li ifmd_flags +.Pq Li int +the interface's flags (defined in +.In net/if.h ) +.It Li ifmd_snd_len +.Pq Li int +the current instantaneous length of the send queue +.It Li ifmd_snd_drops +.Pq Li int +the number of packets dropped at this interface because the send queue +was full +.It Li ifmd_data +.Pq Li struct if_data +more information from a structure defined in +.In net/if.h +(see +.Xr if_data 9 ) +.El +.Pp +Class-specific information can be retrieved by examining the +.Dv IFDATA_LINKSPECIFIC +column instead. +Note that the form and length of the structure will +depend on the class of interface. +For +.Dv IFT_ETHER , +.Dv IFT_ISO88023 , +and +.Dv IFT_STARLAN +interfaces, the structure is called +.Dq Li struct ifmib_iso_8802_3 +(defined in +.In net/if_mib.h ) , +and implements a superset of the +.Tn "RFC 1650" +MIB for Ethernet-like networks. +.\" This will eventually be defined in an ethermib(4) page. +For +.Dv IFT_SLIP , +the structure is a +.Dq Li struct sl_softc +.Pq In net/if_slvar.h . +.Sh SEE ALSO +.Xr sysctl 3 , +.Xr intro 4 , +.Xr ifnet 9 +.\" .Xr ethermib 4 , +.Rs +.%T "Definitions of Managed Objects for the Ethernet-like Interface Types Using SMIv2" +.%A F. Kastenholz +.%D August 1994 +.%O RFC 1650 +.Re +.Sh HISTORY +The +.Nm +interface first appeared in +.Fx 2.2 . +.Sh BUGS +Many Ethernet-like interfaces do not yet support the Ethernet MIB; +the interfaces known to support it include +.Xr ed 4 +and +.Xr de 4 . +Regardless, all interfaces automatically support the generic MIB. |