Add net-snmp ifAlias hook

New script to produce ifAlias information from sysfs.

2 files changed, 123 insertions, 0 deletions

diff --git a/scripts/snmp/if-mib-alias b/scripts/snmp/if-mib-alias
new file mode 100755
index 00000000..c713bfe8
--- /dev/null
+++ b/scripts/snmp/if-mib-alias
@@ -0,0 +1,120 @@
+#! /usr/bin/perl
+
+# **** License ****
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# This code was originally developed by Vyatta, Inc.
+# Portions created by Vyatta are Copyright (C) 2007 Vyatta, Inc.
+# All Rights Reserved.
+#
+# Author: Stig Thormodsrud
+# Date: October 2010
+# Description: script is run as net-snmp extension to read interface alias
+#
+# **** End License ****
+
+use strict;
+use warnings;
+use feature "switch";
+
+# Collect interface alias values
+sub get_alias {
+    my @interfaces;
+
+    open (my $ip, '-|', 'ip li')
+	or die "Can't run ip command\n";
+    my $index;
+    while(<$ip>) {
+	if (/^(\d+): ([^:]*): /) {
+	    $index = $1;
+	    $interfaces[$index] = $2;
+	} elsif (/^ +alias (.*)$/) {
+	    $interfaces[$index] = $1;
+	}
+    }
+    close $ip;
+    return @interfaces;
+}
+
+sub get_oid {
+    my $oid = shift;
+    die "Not a valid Object ID: $oid"
+	unless ($oid =~ /^[0-9.]*\.(\d)$/);
+    my $ifindex = $1;
+    my @interfaces = get_alias();
+
+    my $ifalias = $interfaces[$ifindex];
+    print "$oid\nstring\n$ifalias\n" if $ifalias;
+}
+
+sub get_next {
+    my $oid = shift;
+    die "Not a valid Object ID: $oid"
+	unless ($oid =~ /^([0-9.]*)\.(\d)$/);
+    my $base = $1;
+    my $ifindex = $2;
+    my @interfaces = get_alias();
+
+    while (++$ifindex <= $#interfaces) {
+	my $ifalias = $interfaces[$ifindex];
+	if ($ifalias) {
+	    print "$base.$ifindex\nstring\n$ifalias\n";
+	    last;
+	}
+    }
+}
+
+sub ifindextoname {
+    my $ifindex = shift;
+
+    open (my $ip, '-|', 'ip li')
+	or die "Can't run ip command\n";
+    my $index;
+    while(<$ip>) {
+	next unless (/^(\d+): ([^:]*): /);
+	return $2 if ($1 == $ifindex);
+    }
+    return;
+}
+
+sub set_oid {
+    my ($oid, $target, $value) = @_;
+    die "Not a valid Object ID: $oid"
+	unless ($oid =~ /^[0-9.]*\.(\d)$/);
+    my $ifindex = $1;
+    unless ($target eq 'string') {
+	print "wrong-type\n";
+	return;
+    }
+
+    my $ifname = ifindextoname($ifindex);
+    if ($ifname) {
+	system("ip li set $ifname alias '$value' >/dev/null 2>&1");
+	print "not-writeable\n"	if ($? != 0);
+    }
+}
+
+sub usage {
+    warn "Usage: $0 {-g|-n} OID\n";
+    warn "       $0 -s OID TARGET VALUE\n";
+    exit 1;
+}
+
+usage unless $#ARGV >= 1;
+
+given ($ARGV[0]) {
+    when ('-g') { get_oid ($ARGV[1]); }
+    when ('-n') { get_next ($ARGV[1]); }
+    when ('-s') { set_oid ($ARGV[1], $ARGV[2], $ARGV[3]); }
+    default {
+	warn "$ARGV[0] unknown flag\n";
+	usage;
+    }
+}
diff --git a/scripts/snmp/vyatta-snmp.pl b/scripts/snmp/vyatta-snmp.pl
index e977d619..a812eb32 100644
--- a/scripts/snmp/vyatta-snmp.pl
+++ b/scripts/snmp/vyatta-snmp.pl
@@ -154,6 +154,9 @@ sub snmp_get_constants {
     print "sysServices 14\n";
     print "agentaddress ", join(',',@addr), "\n";
 
+    # add hook to read IF-MIB::ifAlias from sysfs
+    print "pass .1.3.6.1.2.1.31.1.1.1.18 /opt/vyatta/sbin/if-mib-alias\n";
+
     print "smuxpeer .1.3.6.1.4.1.3317.1.2.2\n";		# ospfd
     print "smuxpeer .1.3.6.1.4.1.3317.1.2.5\n";		# bgpd
     print "smuxpeer .1.3.6.1.4.1.3317.1.2.3\n";		# ripd