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4a3dfe69b1
If the analyzer is not found directly attached to the connection, useless error messages are being output. There are now several cases where analyzers are attached within other analyzers so the connection itself doesn't know about the analyzer. This hides these useless messages.
104 lines
2.8 KiB
Text
104 lines
2.8 KiB
Text
##! Activates port-independent protocol detection and selectively disables
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##! analyzers if protocol violations occur.
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module DPD;
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export {
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## Add the DPD logging stream identifier.
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redef enum Log::ID += { LOG };
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## The record type defining the columns to log in the DPD logging stream.
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type Info: record {
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## Timestamp for when protocol analysis failed.
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ts: time &log;
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## Connection unique ID.
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uid: string &log;
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## Connection ID containing the 4-tuple which identifies endpoints.
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id: conn_id &log;
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## Transport protocol for the violation.
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proto: transport_proto &log;
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## The analyzer that generated the violation.
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analyzer: string &log;
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## The textual reason for the analysis failure.
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failure_reason: string &log;
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## Disabled analyzer IDs. This is only for internal tracking
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## so as to not attempt to disable analyzers multiple times.
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disabled_aids: set[count];
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};
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## Analyzers which you don't want to throw
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const ignore_violations: set[Analyzer::Tag] = set() &redef;
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## Ignore violations which go this many bytes into the connection.
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## Set to 0 to never ignore protocol violations.
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const ignore_violations_after = 10 * 1024 &redef;
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}
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redef record connection += {
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dpd: Info &optional;
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};
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event bro_init() &priority=5
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{
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Log::create_stream(DPD::LOG, [$columns=Info, $path="dpd"]);
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}
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event protocol_confirmation(c: connection, atype: Analyzer::Tag, aid: count) &priority=10
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{
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local analyzer = Analyzer::name(atype);
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if ( fmt("-%s",analyzer) in c$service )
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delete c$service[fmt("-%s", analyzer)];
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add c$service[analyzer];
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}
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event protocol_violation(c: connection, atype: Analyzer::Tag, aid: count,
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reason: string) &priority=10
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{
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local analyzer = Analyzer::name(atype);
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# If the service hasn't been confirmed yet, don't generate a log message
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# for the protocol violation.
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if ( analyzer !in c$service )
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return;
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delete c$service[analyzer];
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add c$service[fmt("-%s", analyzer)];
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local info: Info;
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info$ts=network_time();
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info$uid=c$uid;
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info$id=c$id;
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info$proto=get_conn_transport_proto(c$id);
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info$analyzer=analyzer;
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info$failure_reason=reason;
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c$dpd = info;
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}
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event protocol_violation(c: connection, atype: Analyzer::Tag, aid: count, reason: string) &priority=5
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{
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if ( !c?$dpd || aid in c$dpd$disabled_aids )
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return;
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local size = c$orig$size + c$resp$size;
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if ( ignore_violations_after > 0 && size > ignore_violations_after )
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return;
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if ( atype in ignore_violations )
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return;
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# Disable the analyzer that raised the last core-generated event.
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disable_analyzer(c$id, aid, F);
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add c$dpd$disabled_aids[aid];
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}
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event protocol_violation(c: connection, atype: Analyzer::Tag, aid: count,
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reason: string) &priority=-5
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{
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if ( c?$dpd )
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{
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Log::write(DPD::LOG, c$dpd);
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delete c$dpd;
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}
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}
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