zeek/src/packet_analysis/Analyzer.cc
2021-05-18 11:52:03 -07:00

135 lines
3.2 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#include "zeek/packet_analysis/Analyzer.h"
#include "zeek/Dict.h"
#include "zeek/DebugLogger.h"
#include "zeek/RunState.h"
#include "zeek/session/Manager.h"
#include "zeek/util.h"
namespace zeek::packet_analysis {
Analyzer::Analyzer(std::string name, bool report_unknown_protocols) :
report_unknown_protocols(report_unknown_protocols)
{
Tag t = packet_mgr->GetComponentTag(name);
if ( ! t )
reporter->InternalError("unknown packet_analysis name %s", name.c_str());
Init(t);
}
Analyzer::Analyzer(const Tag& tag)
{
Init(tag);
}
void Analyzer::Init(const Tag& _tag)
{
tag = _tag;
}
void Analyzer::Initialize()
{
default_analyzer = LoadAnalyzer("default_analyzer");
}
zeek::packet_analysis::AnalyzerPtr Analyzer::LoadAnalyzer(const std::string &name)
{
auto& analyzer = zeek::id::find(GetModuleName() + name);
if ( ! analyzer )
return nullptr;
auto& analyzer_val = analyzer->GetVal();
if ( ! analyzer_val )
return nullptr;
return packet_mgr->GetAnalyzer(analyzer_val->AsEnumVal());
}
const Tag Analyzer::GetAnalyzerTag() const
{
assert(tag);
return tag;
}
const char* Analyzer::GetAnalyzerName() const
{
assert(tag);
return packet_mgr->GetComponentName(tag).c_str();
}
bool Analyzer::IsAnalyzer(const char* name)
{
assert(tag);
return packet_mgr->GetComponentName(tag) == name;
}
AnalyzerPtr Analyzer::Lookup(uint32_t identifier) const
{
return dispatcher.Lookup(identifier);
}
bool Analyzer::ForwardPacket(size_t len, const uint8_t* data, Packet* packet,
uint32_t identifier) const
{
auto inner_analyzer = Lookup(identifier);
if ( ! inner_analyzer )
inner_analyzer = default_analyzer;
if ( inner_analyzer == nullptr )
{
if ( report_unknown_protocols )
{
DBG_LOG(DBG_PACKET_ANALYSIS, "Analysis in %s failed, could not find analyzer for identifier %#x.",
GetAnalyzerName(), identifier);
packet_mgr->ReportUnknownProtocol(GetAnalyzerName(), identifier, data, len);
return false;
}
else
return true;
}
DBG_LOG(DBG_PACKET_ANALYSIS, "Analysis in %s succeeded, next layer identifier is %#x.",
GetAnalyzerName(), identifier);
return inner_analyzer->AnalyzePacket(len, data, packet);
}
bool Analyzer::ForwardPacket(size_t len, const uint8_t* data, Packet* packet) const
{
if ( default_analyzer )
return default_analyzer->AnalyzePacket(len, data, packet);
DBG_LOG(DBG_PACKET_ANALYSIS, "Analysis in %s stopped, no default analyzer available.",
GetAnalyzerName());
if ( report_unknown_protocols )
Weird("no_suitable_analyzer_found", packet);
return true;
}
void Analyzer::DumpDebug() const
{
#ifdef DEBUG
DBG_LOG(DBG_PACKET_ANALYSIS, "Dispatcher for %s", this->GetAnalyzerName());
dispatcher.DumpDebug();
#endif
}
void Analyzer::RegisterProtocol(uint32_t identifier, AnalyzerPtr child)
{
if ( run_state::detail::zeek_init_done )
reporter->FatalError("Packet protocols cannot be registered after zeek_init has finished.");
dispatcher.Register(identifier, std::move(child));
}
void Analyzer::Weird(const char* name, Packet* packet, const char* addl) const
{
session_mgr->Weird(name, packet, addl, GetAnalyzerName());
}
} // namespace zeek::packet_analysis