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.Dd October 7, 2010
.Dt SNMP_VACM 3
.Os
.Sh NAME
.Nm snmp_vacm
.Nd "View-based Access Control module for"
.Xr bsnmpd 1
.Sh LIBRARY
.Pq begemotSnmpdModulePath."vacm" = "/usr/lib/snmp_vacm.so"
.Sh DESCRIPTION
The
.Nm snmp_vacm
module implements SNMPv3 View-based Access Control Model MIB as defined in
RFC 3415. The module is used to manage the internal lists of SNMPv1, v2c and
v3 user names and groups and their access rights to fetch or modify the values
of the MIB objects maintained by
.Nm bsnmpd
and the modules loaded in the daemon.
The module must be loaded for
.Nm bsnmpd
to implement proper view-based access control. If the module is not loaded,
access is granted to all configured SNMPv1 & SNMPv2c communities and SNMPv3
USM users.
.Sh IMPLEMENTATION NOTES
An entry in any table implemented by this MIB may be created by setting the
relevant RowStatus column to createAndGo (4) - in fact, any other value for
those columns in a SET operation will cause an error. When an entry is created,
any of its columns that is not used as index, is set to the default value as
specified in the SNMP-VIEW-BASED-ACM-MIB. All entries maintained by the module
are persistent after reboot if created via
.Nm bsnmpd 's
config file, otherwise entries created via SNMP are lost after reboot.
A short description of the objects in the MIB follows.
.Bl -tag -width "XXXXXXXXX"
.It Va vacmContextTable
A read-only table that consists of a list of SNMP contexts available in
.Nm bsnmpd .
.It Va vacmSecurityToGroupTable
The table contains a list of SNMPv1, v2c and v3 user names and the groups
they belong to.
.It Va vacmAccessTable
The table contains a list of SNMP contexts to groups mappings and respectively
the names of the SNMP views under those contexts, to which users in the group
are granted read-only, read-write access or receive notifications for the
objects under the subtree in the relevant view.
.It Va vacmViewTreeFamilyTable
The table contains a list of SNMP views, i.e. entries specifying the OID of a
MIB subtree and whether access to the objects under this subtree is to be
allowed or forbidden.
.El
.Sh FILES
.Bl -tag -width "XXXXXXXXX"
.It Pa /usr/share/snmp/defs/vacm_tree.def
The description of the MIB tree implemented by
.Nm .
.El
.Sh SEE ALSO
.Xr bsnmpd 1 ,
.Xr gensnmptree 1 ,
.Xr snmpmod 3
.Sh STANDARDS
IETF RFC 3415
.Sh AUTHORS
.An Shteryana Shopova Aq syrinx@FreeBSD.org