path: root/scripts/snmp/vyatta-snmp-v3.pl

#!/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) 2013 Vyatta, Inc.
# All Rights Reserved.
#
# **** End License ****

use strict;
use warnings;

use lib "/opt/vyatta/share/perl5/";
use Vyatta::Config;
use File::Copy;
use Getopt::Long;
use Socket;
use Socket6;

my $snmp_v3_level      = 'service snmp v3';
my $snmp_init          = 'invoke-rc.d snmpd';
my $snmpd_conf         = '/etc/snmp/snmpd.conf';
my $snmpd_usr_conf     = '/usr/share/snmp/snmpd.conf';
my $snmpd_var_conf     = '/var/lib/snmp/snmpd.conf';
my $snmpd_conf_tmp     = "/tmp/snmpd.conf.$$";
my $snmpd_usr_conf_tmp = "/tmp/snmpd.usr.conf.$$";
my $snmpd_var_conf_tmp = "/tmp/snmpd.var.conf.$$";
my $versionfile        = '/opt/vyatta/etc/version';
my $local_agent        = 'unix:/var/run/snmpd.socket';
my $vyatta_config_file = '/config/snmp/snmp_conf.ini';

my %VConfig = ();

my %OIDs = (
    "md5",  ".1.3.6.1.6.3.10.1.1.2", "sha", ".1.3.6.1.6.3.10.1.1.3",
    "aes",  ".1.3.6.1.6.3.10.1.2.4", "des", ".1.3.6.1.6.3.10.1.2.2",
    "none", ".1.3.6.1.6.3.10.1.2.1"
);

# generate a random character hex string
sub randhex {
    my $length = shift;
    return join "", map { unpack "H*", chr( rand(256) ) } 1 .. ( $length / 2 );
}

sub parse_config_file {
    open( my $cfg, '<', $vyatta_config_file )
      or return;
    while (<$cfg>) {
        chomp;       # no newline
        s/#.*//;     # no comments
        s/^\s+//;    # no leading white
        s/\s+$//;    # no trailing white
        next unless length;    # anything left?
        my ( $var, $value ) = split( /\s*=\s*/, $_, 2 );
        $VConfig{$var} = $value;
    }
    close($cfg);
}

sub write_config_file {
    open( my $config_file, '>', "$vyatta_config_file" );
    for my $key ( keys %VConfig ) {
        my $value = $VConfig{$key};
        print $config_file "$key=$value\n";
    }
    close $config_file;
}

sub snmpd_running {
    open( my $pidf, '<', "/var/run/snmpd.pid" )
      or return;
    my $pid = <$pidf>;
    close $pidf;

    chomp $pid;
    my $exe = readlink "/proc/$pid/exe";

    return ( defined($exe) && $exe eq "/usr/sbin/snmpd" );
}

sub check_snmp_exit_code {
    my $code = shift;

    # snmpd can start/restart with exit code 256 if trap-target is unavailable
    if ( $code != 0 && $code != 256 ) {
        return 1;
    }
    else {
        return 0;
    }
}

sub snmpd_stop {
    system(
"start-stop-daemon --stop --exec /usr/sbin/snmpd --oknodo -R 2 > /dev/null 2>&1"
    );
    if ( check_snmp_exit_code($?) ) {
        print "ERROR: Can not stop snmpd!\n";
        exit(1);
    }
}

sub snmpd_start {
    system("$snmp_init start > /dev/null 2>&1");
    if ( check_snmp_exit_code($?) ) {
        print "ERROR: Can not start snmpd!\n";
        exit(1);
    }
}

sub snmpd_update {
    system("$snmp_init reload > /dev/null 2>&1");
    if ( check_snmp_exit_code($?) ) {
        print "ERROR: Can not reload snmpd!\n";
        exit(1);
    }
}

sub snmpd_restart {
    system("$snmp_init restart > /dev/null 2>&1");
    if ( check_snmp_exit_code($?) ) {
        print "ERROR: Can not restart snmpd!\n";
        exit(1);
    }
}

sub get_version {
    my $version = "unknown-version";

    if ( open( my $f, '<', $versionfile ) ) {
        while (<$f>) {
            chomp;
            if (m/^Version\s*:\s*(.*)$/) {
                $version = $1;
                last;
            }
        }
        close $f;
    }
    return $version;
}

sub ipv6_disabled {
    socket( my $s, PF_INET6, SOCK_DGRAM, 0 )
      or return 1;
    close($s);
    return;
}

sub set_tsm {
    my $config = get_snmp_config();
    if ( $config->exists("tsm") ) {
        my $port      = $config->returnValue("tsm port");
        my $local_key = $config->returnValue("tsm local-key");
        system(
"sed -i 's/^agentaddress.*\$/&,tlstcp:$port,dtlsudp:$port/' $snmpd_conf_tmp"
        );
        system("echo \"[snmp] localCert $local_key\" >> $snmpd_conf_tmp");
    }
}

sub snmp_delete {
    snmpd_stop();

    my @files = ( $snmpd_conf, $snmpd_usr_conf, $snmpd_var_conf );
    foreach my $file (@files) {
        if ( -e $file ) {
            unlink($file);
        }
    }
}

sub get_snmp_config {
    my $config = new Vyatta::Config;
    $config->setLevel($snmp_v3_level);
    return $config;
}

sub set_views {
    print "# views \n";
    my $config = get_snmp_config();
    foreach my $view ( $config->listNodes("view") ) {
        foreach my $oid ( $config->listNodes("view $view oid") ) {
            my $mask = '';
            $mask = $config->returnValue("view $view oid $oid mask")
              if $config->exists("view $view oid $oid mask");
            if ( $config->exists("view $view oid $oid exclude") ) {
                print "view $view excluded .$oid $mask\n";
            }
            else {
                print "view $view included .$oid $mask\n";
            }
        }
    }
    print "\n";
}

sub set_groups {
    print
"#access\n#             context sec.model sec.level match  read    write  notif\n";
    my $config = get_snmp_config();
    foreach my $group ( $config->listNodes("group") ) {
        my $mode     = $config->returnValue("group $group mode");
        my $view     = $config->returnValue("group $group view");
        my $secLevel = $config->returnValue("group $group seclevel");
        if ( $mode eq "ro" ) {
            print "access $group \"\" usm $secLevel exact $view none none\n";
            print "access $group \"\" tsm $secLevel exact $view none none\n";
        }
        else {
            print "access $group \"\" usm $secLevel exact $view $view none\n";
            print "access $group \"\" tsm $secLevel exact $view $view none\n";
        }
    }
    print "\n";
}

sub set_users_in_etc {

    print "#group\n";
    my $tsm_counter = 0;
    my $config      = get_snmp_config();
    foreach my $user ( $config->listNodes("user") ) {
        $config->setLevel( $snmp_v3_level . " user $user" );
        if ( $config->exists("group") ) {
            my $group = $config->returnValue("group");
            print "group $group usm $user\n";
            print "group $group tsm $user\n";
        }
        if ( $config->exists("tsm-key") ) {
            my $cert = $config->returnValue("tsm-key");
            $tsm_counter++;
            print "certSecName $tsm_counter $cert --sn $user\n";
        }
    }

    print "\n";
}

sub set_users_to_other {
    open( my $usr_conf, '>>', $snmpd_usr_conf_tmp )
      or die "Couldn't open $snmpd_usr_conf_tmp - $!";
    open( my $var_conf, '>>', $snmpd_var_conf_tmp )
      or die "Couldn't open $snmpd_var_conf_tmp - $!";

    print $var_conf "\n";

    my $config  = get_snmp_config();
    my $needTsm = 0;
    if ( $config->exists("tsm") ) {
        $needTsm = 1;
    }

    my %trap_users = ();

    foreach my $trap ( $config->listNodes("trap-target") ) {
        $trap_users{ $config->returnValue("trap-target $trap user") } = 1;
    }

    foreach my $user ( $config->listNodes("user") ) {
        delete $trap_users{$user};
        $config->setLevel( $snmp_v3_level . " user $user" );
        my $auth_type = $config->returnValue("auth type");
        my $priv_type = $config->returnValue("privacy type");
        if ( $config->exists("auth") ) {
            if ( $config->exists("auth plaintext-key") ) {
                my $auth_key = $config->returnValue("auth plaintext-key");
                my $priv_key = '';
                $priv_key = $config->returnValue("privacy plaintext-key")
                  if $config->exists("privacy plaintext-key");
                print $var_conf
"createUser $user \U$auth_type\E $auth_key \U$priv_type\E $priv_key\n";
            }
            else {
                my $name_print    = get_printable_name($user);
                my $EngineID      = $VConfig{"User.$user.EngineID"};
                my $auth_type_oid = $OIDs{$auth_type};
                my $auth_key_hex  = $config->returnValue("auth encrypted-key");

                my ( $priv_type_oid, $priv_key_hex );
                if ( $config->exists("privacy") ) {
                    $priv_type_oid = $OIDs{$priv_type};
                    $priv_key_hex =
                      $config->returnValue("privacy encrypted-key");
                }
                else {
                    $priv_type_oid = $OIDs{'none'};
                    $priv_key_hex  = '0x';
                }
                print $var_conf
"usmUser 1 3 $EngineID $name_print $name_print NULL $auth_type_oid $auth_key_hex $priv_type_oid $priv_key_hex 0x\n";
            }
        }
        my $mode = $config->returnValue("mode");
        my $end  = "auth";
        if ( $config->exists("privacy") ) {
            $end = "priv";
        }
        print $usr_conf $mode . "user $user $end\n";
        if ($needTsm) {
            print $usr_conf $mode . "user -s tsm $user $end\n";
        }
    }

    foreach my $user ( keys %trap_users ) {
        my $name_print = get_printable_name($user);
        print $var_conf "usmUser 1 3 0x"
          . randhex(26)
          . " $name_print $name_print NULL .1.3.6.1.6.3.10.1.1.2 0x"
          . randhex(32)
          . " .1.3.6.1.6.3.10.1.2.1 0x 0x\n";
        print $usr_conf "rouser $user auth\n";
    }

    print $var_conf "setserialno " . $VConfig{"serialno"} . "\n"
      if exists $VConfig{"serialno"};
    print $var_conf "oldEngineID " . $VConfig{"oldEngineID"} . "\n"
      if exists $VConfig{"oldEngineID"};

    close $usr_conf;
    close $var_conf;
}

sub get_printable_name {
    my $name = shift;
    if ( $name =~ /-/ ) {
        my @array = unpack( 'C*', $name );
        my $stringHex = '0x';
        foreach my $c (@array) {
            $stringHex .= sprintf( "%lx", $c );
        }
        return $stringHex;
    }
    else {
        return "\"$name\"";
    }
}

sub update_users_vyatta_conf {
    %VConfig = ();
    open( my $var_conf, '<', $snmpd_var_conf )
      or die "Couldn't open $snmpd_usr_conf - $!";
    my $config = get_snmp_config();
    while ( my $line = <$var_conf> ) {
        if ( $line =~ /^setserialno (.*)$/ ) {
            $VConfig{"serialno"} = $1;
        }
        if ( $line =~ /^oldEngineID (.*)$/ ) {
            $VConfig{"oldEngineID"} = $1;
        }
        if ( $line =~ /^usmUser / ) {
            my @values = split( / /, $line );
            my $name = $values[4];
            if ( $name =~ /^"(.*)"$/ ) {
                $name = $1;
            }
            else {
                $name = pack( 'H*', $name );
            }

            # this file contain users for trap-target and vyatta... user
            # these users recreating automatically on each commit
            if ( $config->exists("user $name") ) {
                $VConfig{"User.$name.EngineID"} = $values[3];
                system(
"/opt/vyatta/sbin/my_set service snmp v3 user \"$name\" auth encrypted-key $values[8] > /dev/null"
                );
                if ( $values[10] ne "\"\"" && $values[10] ne "0x" ) {
                    system(
"/opt/vyatta/sbin/my_set service snmp v3 user \"$name\" privacy encrypted-key $values[10] > /dev/null"
                    );
                    system(
"/opt/vyatta/sbin/my_delete service snmp v3 user \"$name\" privacy plaintext-key > /dev/null"
                    );
                }
                system(
"/opt/vyatta/sbin/my_delete service snmp v3 user \"$name\" auth plaintext-key > /dev/null"
                );
            }
        }
    }
    close $var_conf;
}

sub set_hosts {
    print "#trap-target\n";
    my $config = get_snmp_config();
    foreach my $target ( $config->listNodes("trap-target") ) {
        $config->setLevel( $snmp_v3_level . " trap-target $target" );
        my $auth_key = '';
        if ( $config->exists("auth plaintext-key") ) {
            $auth_key = "-A " . $config->returnValue("auth plaintext-key");
        }
        else {
            $auth_key = "-3m " . $config->returnValue("auth encrypted-key");
        }
        my $auth_type   = $config->returnValue("auth type");
        my $user        = $config->returnValue("user");
        my $port        = $config->returnValue("port");
        my $protocol    = $config->returnValue("protocol");
        my $type        = $config->returnValue("type");
        my $inform_flag = '-Ci';
        $inform_flag = '-Ci' if ( $type eq 'inform' );

        if ( $type eq 'trap' ) {
            $inform_flag = '-e ' . $config->returnValue("engineid");
        }
        my $privacy  = '';
        my $secLevel = 'authNoPriv';
        if ( $config->exists("privacy") ) {
            my $priv_key = '';
            if ( $config->exists("privacy plaintext-key") ) {
                $priv_key =
                  "-X " . $config->returnValue("privacy plaintext-key");
            }
            else {
                $priv_key =
                  "-3M " . $config->returnValue("privacy encrypted-key");
            }
            my $priv_type = $config->returnValue("privacy type");
            $privacy  = "-x $priv_type $priv_key";
            $secLevel = 'authPriv';
        }

        # TODO
        # set -3m / -3M for auth / priv  for master
        # or -3k / -3K for local
        my $target_print = $target;
        if ( $target =~ /:/ ) {
            $target_print = "[$target]";
            $protocol     = $protocol . "6";
        }
        print
"trapsess -v 3 $inform_flag -u $user -l $secLevel -a $auth_type $auth_key $privacy $protocol:$target_print:$port\n";
    }
    print "\n";
}

sub check_user_auth_changes {
    my $config = get_snmp_config();
    if ( $config->isChanged("user") ) {
        my $haveError = 0;
        foreach my $user ( $config->listNodes("user") ) {
            $config->setLevel( $snmp_v3_level . " user $user" );
            if ( $config->exists("auth") ) {
                if (
                    $config->isChanged("auth encrypted-key")
                    || (   $config->exists("privacy")
                        && $config->isChanged("privacy encrypted-key") )
                  )
                {
                    $haveError = 1;
                    print
"Discard encrypted-key on user \"$user\". You can't change encrypted key. It does not supported yet.\n";
                }
                my $isAuthKeyChanged = $config->isChanged("auth plaintext-key");
                my $isAuthChanged    = $isAuthKeyChanged
                  || $config->isChanged("auth type");
                if ( ( $isAuthChanged || $config->isDeleted("privacy") )
                    && !$isAuthKeyChanged )
                {
                    $haveError = 1;
                    print "Please, set auth plaintext-key for user \"$user\"\n";
                }
                if ( $config->exists("privacy") ) {
                    my $isPrivKeyChanged =
                      $config->isChanged("privacy plaintext-key");
                    my $isPrivChanged = $isPrivKeyChanged
                      || $config->isChanged("privacy type");
                    if ( $isPrivChanged && !$isAuthKeyChanged ) {
                        $haveError = 1;
                        print
                          "Please, set auth plaintext-key for user \"$user\"\n";
                    }
                    if ( ( $isAuthChanged || $isPrivChanged )
                        && !$isPrivKeyChanged )
                    {
                        $haveError = 1;
                        print
"Please, set privacy plaintext-key for user \"$user\"\n";
                    }
                }
            }
            else {
                if ( $config->exists("privacy") ) {
                    $haveError = 1;
                    print "Please, delete privacy for user \"$user\"\n";
                }
            }
        }
        if ($haveError) {
            exit(1);
        }
    }
}

sub check_relation {
    my $config    = get_snmp_config();
    my $haveError = 0;
    foreach my $user ( $config->listNodes("user") ) {
        if ( $config->exists("user $user group") ) {
            my $group = $config->returnValue("user $user group");
            if ( !$config->exists("group $group") ) {
                $haveError = 1;
                print
"Please, create group \"$group\". It's need for user \"$user\"\n";
            }
        }
    }
    foreach my $group ( $config->listNodes("group") ) {
        my $view = $config->returnValue("group $group view");
        if ( !$config->exists("view $view") ) {
            $haveError = 1;
            print
              "Please, create view \"$view\". It's need for group \"$group\"\n";
        }
    }
    if ($haveError) {
        exit(1);
    }
}

sub check_tsm_port {
    my $config = get_snmp_config();
    if ( $config->isChanged("tsm port") ) {
        my $port   = $config->returnValue("tsm port");
        my $reg    = ":$port\$";
        my $output = `netstat -anltup | awk '{print  \$4}'`;
        foreach my $line ( split( /\n/, $output ) ) {
            if ( $line =~ /$reg/ ) {
                print
                  "Actually port $port is using. It can not be used for tsm.\n";
                exit(1);
            }
        }
    }
}

sub check_seclevel {
    my $config    = get_snmp_config();
    my $haveError = 0;
    if ( $config->isChanged("user") || $config->isChanged("group") ) {
        foreach my $user ( $config->listNodes("user") ) {
            if ( $config->exists("user $user group") ) {
                my $group = $config->returnValue("user $user group");
                if (   $config->isChanged("user $user")
                    || $config->isChanged("group $group") )
                {
                    my $group_seclevel =
                      $config->returnValue("group $group seclevel");
                    if ( $config->exists("user $user privacy") ) {
                        if ( $group_seclevel eq "auth" ) {
                            print
"User \"$user\" have privacy, but group \"$group\" have \"auth\" as seclevel. So auth and priv work both.\n";
                        }
                    }
                    else {
                        if ( $group_seclevel eq "priv" ) {
                            print
"User \"$user\" will not work, because he haven't privacy, but group \"$group\" have \"priv\" as seclevel.\n";
                            $haveError = 1;
                        }
                    }
                }
            }
        }
    }
    if ($haveError) {
        exit(1);
    }
}

sub copy_conf_to_tmp {

    # these files already contain SNMPv2 configuration
    copy( $snmpd_conf, $snmpd_conf_tmp )
      or die "Couldn't copy $snmpd_conf to $snmpd_conf_tmp - $!";
    copy( $snmpd_usr_conf, $snmpd_usr_conf_tmp )
      or die "Couldn't copy $snmpd_usr_conf to $snmpd_usr_conf_tmp - $!";
    copy( $snmpd_var_conf, $snmpd_var_conf_tmp )
      or die "Couldn't copy $snmpd_var_conf to $snmpd_var_conf_tmp - $!";
}

sub snmp_update {

    copy_conf_to_tmp();

    set_tsm();

    open( my $fh, '>>', $snmpd_conf_tmp )
      or die "Couldn't open $snmpd_conf_tmp - $!";

    select $fh;

    set_views();
    set_groups();
    set_hosts();
    set_users_in_etc();

    close $fh;
    select STDOUT;

    move( $snmpd_conf_tmp, $snmpd_conf )
      or die "Couldn't move $snmpd_conf_tmp to $snmpd_conf - $!";

    my $config = get_snmp_config();

    parse_config_file();
    snmpd_stop();
    set_users_to_other();
    move( $snmpd_usr_conf_tmp, $snmpd_usr_conf )
      or die "Couldn't move $snmpd_usr_conf_tmp to $snmpd_usr_conf - $!";
    move( $snmpd_var_conf_tmp, $snmpd_var_conf )
      or die "Couldn't move $snmpd_var_conf_tmp to $snmpd_var_conf - $!";
    snmpd_start();
    snmpd_stop();
    snmpd_start();
    update_users_vyatta_conf();
    write_config_file();

}

sub snmp_check {
    check_user_auth_changes();
    check_relation();
    check_tsm_port();
    check_seclevel();
}

my $check_config;
my $update_snmp;
my $delete_snmp;

GetOptions(
    "check-config!" => \$check_config,
    "update-snmp!"  => \$update_snmp,
    "delete-snmp!"  => \$delete_snmp
);

snmp_check()  if ($check_config);
snmp_update() if ($update_snmp);
snmp_delete() if ($delete_snmp);