Section 3.42.17. HostStateChangeHook

3.42.17. HostStateChangeHook

This optional parameter allows you to define a Perl function that will be called when the reachability of a next hop Host changes. See section Section 3.42.1. Failure algorithm for more about reachability detection. The following arguments are passed in the following order:

Reference to the request that was sent to the Host but received no reply and triggered the change state. Request type is Status-Server when this request type is used for reachability detection.
Reference to this Radius::AuthRADSEC structure
Reference to the Radius::Host structure for the remote host
New host state. One of integer constant values:
- $Radius::AuthRADIUS::HOST_STATE::REACHABLE
- $Radius::AuthRADIUS::HOST_STATE::UNREACHABLE
IP address of the Host that is now reachable or unreachable
Port on the Host that is now reachable or unreachable

The hook code is compiled by Perl when Radiator starts up. Compilation errors in your hook code will be reported to the log file at start-up time. Runtime errors in your hook will also be reported to the log file when your hook executes. Multiline hooks (i.e. with trailing backslashes (\)) are parsed by Radiator into one long line. Therefore you should not use trailing comments in your hook.

HostStateChangeHook can be an arbitrarily complicated Perl function, that might run external processes, consult databases, change the contents of the current request or many other things. The following example shows how to use the state constants, store the state over hook invocations and log information from the hook.

HostStateChangeHook sub { \
    my ($p, $self, $host, $new_state, $ip, $port) = @_; \

    my $old_state = $host->{state_change_hook_current_state}; \
    $old_state = $Radius::AuthRADIUS::HOST_STATE::REACHABLE
        unless defined $old_state; \

    return if $old_state == $new_state; \
    $host->{state_change_hook_current_state} = $new_state; \

    my $st = ($new_state == $Radius::AuthRADIUS::HOST_STATE::UNREACHABLE) ?
             'Unreachable' : 'Reachable'; \
    my $msg = "HostStateChangeHook: IP '$ip', Port '$port', New State: '$st'"; \
    $self->log($main::LOG_INFO, "$self->{log_class_identifier} $msg", $p); \
    return; }