zeek/scripts/base/frameworks/netcontrol/plugins/acld.bro
Daniel Thayer d91dd8d9a8 Fix Bro and unit tests when broker is not enabled
When Bro was compiled with broker disabled, then some Bro scripts
were referencing functions and types that were not defined.  Fixed
by adding @ifdefs to several scripts.  Removed one @ifdef because
it was causing several unit tests to fail.

Also fixed the @TEST-REQUIRES check in tests that rely on broker so
that such tests are skipped when broker is disabled.
2016-05-10 06:24:35 -05:00

297 lines
8 KiB
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##! Acld plugin for the netcontrol framework.
module NetControl;
@load ../main
@load ../plugin
@load base/frameworks/broker
@ifdef ( Broker::__enable )
export {
type AclRule : record {
command: string;
cookie: count;
arg: string;
comment: string &optional;
};
type AcldConfig: record {
## The acld topic used to send events to
acld_topic: string;
## Broker host to connect to
acld_host: addr;
## Broker port to connect to
acld_port: port;
## Do we accept rules for the monitor path? Default false
monitor: bool &default=F;
## Do we accept rules for the forward path? Default true
forward: bool &default=T;
## Predicate that is called on rule insertion or removal.
##
## p: Current plugin state
##
## r: The rule to be inserted or removed
##
## Returns: T if the rule can be handled by the current backend, F otherwhise
check_pred: function(p: PluginState, r: Rule): bool &optional;
};
## Instantiates the acld plugin.
global create_acld: function(config: AcldConfig) : PluginState;
redef record PluginState += {
acld_config: AcldConfig &optional;
## The ID of this acld instance - for the mapping to PluginStates
acld_id: count &optional;
};
## Hook that is called after a rule is converted to an acld rule.
## The hook may modify the rule before it is sent to acld.
## Setting the acld command to F will cause the rule to be rejected
## by the plugin
##
## p: Current plugin state
##
## r: The rule to be inserted or removed
##
## ar: The acld rule to be inserted or removed
global NetControl::acld_rule_policy: hook(p: PluginState, r: Rule, ar: AclRule);
## Events that are sent from us to Broker
global acld_add_rule: event(id: count, r: Rule, ar: AclRule);
global acld_remove_rule: event(id: count, r: Rule, ar: AclRule);
## Events that are sent from Broker to us
global acld_rule_added: event(id: count, r: Rule, msg: string);
global acld_rule_removed: event(id: count, r: Rule, msg: string);
global acld_rule_error: event(id: count, r: Rule, msg: string);
}
global netcontrol_acld_peers: table[port, string] of PluginState;
global netcontrol_acld_topics: set[string] = set();
global netcontrol_acld_id: table[count] of PluginState = table();
global netcontrol_acld_current_id: count = 0;
const acld_add_to_remove: table[string] of string = {
["drop"] = "restore",
["whitelist"] = "remwhitelist",
["blockhosthost"] = "restorehosthost",
["droptcpport"] = "restoretcpport",
["dropudpport"] = "restoreudpport",
["droptcpdsthostport"] ="restoretcpdsthostport",
["dropudpdsthostport"] ="restoreudpdsthostport",
["permittcpdsthostport"] ="unpermittcpdsthostport",
["permitudpdsthostport"] ="unpermitudpdsthostport",
["nullzero"] ="nonullzero"
};
event NetControl::acld_rule_added(id: count, r: Rule, msg: string)
{
if ( id !in netcontrol_acld_id )
{
Reporter::error(fmt("NetControl acld plugin with id %d not found, aborting", id));
return;
}
local p = netcontrol_acld_id[id];
event NetControl::rule_added(r, p, msg);
}
event NetControl::acld_rule_removed(id: count, r: Rule, msg: string)
{
if ( id !in netcontrol_acld_id )
{
Reporter::error(fmt("NetControl acld plugin with id %d not found, aborting", id));
return;
}
local p = netcontrol_acld_id[id];
event NetControl::rule_removed(r, p, msg);
}
event NetControl::acld_rule_error(id: count, r: Rule, msg: string)
{
if ( id !in netcontrol_acld_id )
{
Reporter::error(fmt("NetControl acld plugin with id %d not found, aborting", id));
return;
}
local p = netcontrol_acld_id[id];
event NetControl::rule_error(r, p, msg);
}
function acld_name(p: PluginState) : string
{
return fmt("Acld-%s", p$acld_config$acld_topic);
}
# check that subnet specifies an addr
function check_sn(sn: subnet) : bool
{
if ( is_v4_subnet(sn) && subnet_width(sn) == 32 )
return T;
if ( is_v6_subnet(sn) && subnet_width(sn) == 128 )
return T;
Reporter::error(fmt("Acld: rule_to_acl_rule was given a subnet that does not specify a distinct address where needed - %s", sn));
return F;
}
function rule_to_acl_rule(p: PluginState, r: Rule) : AclRule
{
local e = r$entity;
local command: string = "";
local arg: string = "";
if ( e$ty == ADDRESS )
{
if ( r$ty == DROP )
command = "drop";
else if ( r$ty == WHITELIST )
command = "whitelist";
arg = cat(e$ip);
}
else if ( e$ty == FLOW )
{
local f = e$flow;
if ( ( ! f?$src_h ) && ( ! f?$src_p ) && f?$dst_h && f?$dst_p && ( ! f?$src_m ) && ( ! f?$dst_m ) )
{
if ( !check_sn(f$dst_h) )
command = ""; # invalid addr, do nothing
else if ( is_tcp_port(f$dst_p) && r$ty == DROP )
command = "droptcpdsthostport";
else if ( is_tcp_port(f$dst_p) && r$ty == WHITELIST )
command = "permittcpdsthostport";
else if ( is_udp_port(f$dst_p) && r$ty == DROP)
command = "dropucpdsthostport";
else if ( is_udp_port(f$dst_p) && r$ty == WHITELIST)
command = "permitucpdsthostport";
arg = fmt("%s %d", subnet_to_addr(f$dst_h), f$dst_p);
}
else if ( f?$src_h && ( ! f?$src_p ) && f?$dst_h && ( ! f?$dst_p ) && ( ! f?$src_m ) && ( ! f?$dst_m ) )
{
if ( !check_sn(f$src_h) || !check_sn(f$dst_h) )
command = "";
else if ( r$ty == DROP )
command = "blockhosthost";
arg = fmt("%s %s", subnet_to_addr(f$src_h), subnet_to_addr(f$dst_h));
}
else if ( ( ! f?$src_h ) && ( ! f?$src_p ) && ( ! f?$dst_h ) && f?$dst_p && ( ! f?$src_m ) && ( ! f?$dst_m ) )
{
if ( is_tcp_port(f$dst_p) && r$ty == DROP )
command = "droptcpport";
else if ( is_udp_port(f$dst_p) && r$ty == DROP )
command = "dropudpport";
arg = fmt("%d", f$dst_p);
}
}
local ar = AclRule($command=command, $cookie=r$cid, $arg=arg);
if ( r?$location )
ar$comment = r$location;
hook NetControl::acld_rule_policy(p, r, ar);
return ar;
}
function acld_check_rule(p: PluginState, r: Rule) : bool
{
local c = p$acld_config;
if ( p$acld_config?$check_pred )
return p$acld_config$check_pred(p, r);
if ( r$target == MONITOR && c$monitor )
return T;
if ( r$target == FORWARD && c$forward )
return T;
return F;
}
function acld_add_rule_fun(p: PluginState, r: Rule) : bool
{
if ( ! acld_check_rule(p, r) )
return F;
local ar = rule_to_acl_rule(p, r);
if ( ar$command == "" )
return F;
Broker::send_event(p$acld_config$acld_topic, Broker::event_args(acld_add_rule, p$acld_id, r, ar));
return T;
}
function acld_remove_rule_fun(p: PluginState, r: Rule) : bool
{
if ( ! acld_check_rule(p, r) )
return F;
local ar = rule_to_acl_rule(p, r);
if ( ar$command in acld_add_to_remove )
ar$command = acld_add_to_remove[ar$command];
else
return F;
Broker::send_event(p$acld_config$acld_topic, Broker::event_args(acld_remove_rule, p$acld_id, r, ar));
return T;
}
function acld_init(p: PluginState)
{
Broker::enable();
Broker::connect(cat(p$acld_config$acld_host), p$acld_config$acld_port, 1sec);
Broker::subscribe_to_events(p$acld_config$acld_topic);
}
event Broker::outgoing_connection_established(peer_address: string, peer_port: port, peer_name: string)
{
if ( [peer_port, peer_address] !in netcontrol_acld_peers )
# ok, this one was none of ours...
return;
local p = netcontrol_acld_peers[peer_port, peer_address];
plugin_activated(p);
}
global acld_plugin = Plugin(
$name=acld_name,
$can_expire = F,
$add_rule = acld_add_rule_fun,
$remove_rule = acld_remove_rule_fun,
$init = acld_init
);
function create_acld(config: AcldConfig) : PluginState
{
if ( config$acld_topic in netcontrol_acld_topics )
Reporter::warning(fmt("Topic %s was added to NetControl acld plugin twice. Possible duplication of commands", config$acld_topic));
else
add netcontrol_acld_topics[config$acld_topic];
local host = cat(config$acld_host);
local p: PluginState = [$acld_config=config, $plugin=acld_plugin, $acld_id=netcontrol_acld_current_id];
if ( [config$acld_port, host] in netcontrol_acld_peers )
Reporter::warning(fmt("Peer %s:%s was added to NetControl acld plugin twice.", host, config$acld_port));
else
netcontrol_acld_peers[config$acld_port, host] = p;
netcontrol_acld_id[netcontrol_acld_current_id] = p;
++netcontrol_acld_current_id;
return p;
}
@endif