From 9a0915f3a15999a5edd11ea00b7426a1cbf63bb4 Mon Sep 17 00:00:00 2001
From: Bill Fenner <>
Date: Sun, 2 Dec 2007 18:55:54 +0000
Subject: [PATCH] Infrastructure for SNMPv3 support: - Save the SecName passed
 into the constructor - Create an update() function, which replaces the
 underlying   SNMP session using different parameters. - Return the SecName
 instead of community from snmp_comm() when using   SNMPv3.  This is a little
 wrong, but is probably better than returning   undef.

---
 Info.pm | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/Info.pm b/Info.pm
index d630ad56..1c79332c 100644
--- a/Info.pm
+++ b/Info.pm
@@ -905,11 +905,59 @@ sub new {
     $new_obj->{args}      = \%args;
     $new_obj->{snmp_ver}  = $args{Version}   || 2;
     $new_obj->{snmp_comm} = $args{Community} || 'public';
+    $new_obj->{snmp_user} = $args{SecName}   || 'initial';
 
     return $auto_specific ?
         $new_obj->specify() : $new_obj;
 }
 
+=item update()
+
+Replace the existing session with a new one with updated values,
+without re-identifying the device.  The only supported changes are
+to Community or Context.
+
+Clears the object cache.
+
+This is useful, e.g., when a device supports multiple contexts
+(via changes to the Community string, or via the SNMPv3 Context
+parameter), but a context that you want to access does not support
+the objects (e.g., sysObjectID, sysDescr) that we use to identify
+the device.
+
+=cut
+
+sub update {
+    my $obj = shift;
+    my %update_args = @_;
+    my %sess_args = (%{$obj->{args}}, %update_args);
+
+    # silently only update "the right" args
+    delete $sess_args{Debug};
+    delete $sess_args{DebugSNMP};
+    delete $sess_args{AutoSpecify};
+    delete $sess_args{BulkRepeaters};
+    delete $sess_args{BulkWalk};
+    delete $sess_args{LoopDetect};
+    delete $sess_args{BigInt};
+    delete $sess_args{MibDirs};
+
+    my $sess = new SNMP::Session( 'UseEnums' => 1, %sess_args , 'RetryNoSuch' => $obj->{nosuch});
+    unless (defined $sess){
+        $obj->error_throw("SNMP::Info::update() Failed to Create new Session. ");
+        return undef;
+    }
+
+    # Session object created but SNMP connection failed.
+    my $sess_err = $sess->{ErrorStr} || '';
+    if ($sess_err){
+        $obj->error_throw("SNMP::Info::update() Net-SNMP session creation failed. $sess_err");
+        return undef;
+    }
+    $obj->clear_cache();
+    return $obj->session($sess);
+}
+
 =back
 
 =head2 Data is Cached
@@ -1288,7 +1336,11 @@ Returns SNMP Community string used in connection.
 
 sub snmp_comm {
     my $self = shift;
-    return $self->{snmp_comm};
+    if ($self->{snmp_ver} == 3) {
+	return $self->{snmp_user};
+    } else {
+	return $self->{snmp_comm};
+    }
 }
 
 =item $info->snmp_ver()