Simplify and fix TCP netprobe probe (#690)

* add connect failure metric
* simplify tcp probe. use target id for transaction id.
* remove header, add some comments
* use port based transaction id (via string) for icmp

src/handlers/netprobe/NetProbeStreamHandler.cpp

@@ -79,7 +79,7 @@ void NetProbeStreamHandler::probe_signal_send(pcpp::Packet &payload, TestType ty
         }
     } else if (type == TestType::TCP) {
         if (auto tcp = payload.getLayerOfType<pcpp::TcpLayer>(); tcp != nullptr) {
-            _metrics->process_netprobe_tcp(static_cast<uint32_t>(tcp->getSrcPort()), true, name, stamp);
+            _metrics->process_netprobe_tcp(true, name, stamp);
         }
     }
 }
@@ -92,7 +92,7 @@ void NetProbeStreamHandler::probe_signal_recv(pcpp::Packet &payload, TestType ty
         }
     } else if (type == TestType::TCP) {
         if (auto tcp = payload.getLayerOfType<pcpp::TcpLayer>(); tcp != nullptr) {
-            _metrics->process_netprobe_tcp(static_cast<uint32_t>(tcp->getDstPort()), false, name, stamp);
+            _metrics->process_netprobe_tcp(false, name, stamp);
         }
     }
 }
@@ -119,6 +119,7 @@ void NetProbeMetricsBucket::specialized_merge(const AbstractMetricsBucket &o, Me
         if (group_enabled(group::NetProbeMetrics::Counters)) {
             _targets_metrics[targetId]->attempts += target.second->attempts;
             _targets_metrics[targetId]->successes += target.second->successes;
+            _targets_metrics[targetId]->connect_failures += target.second->connect_failures;
             _targets_metrics[targetId]->dns_failures += target.second->dns_failures;
             _targets_metrics[targetId]->timed_out += target.second->timed_out;
         }
@@ -143,6 +144,7 @@ void NetProbeMetricsBucket::to_prometheus(std::stringstream &out, Metric::LabelM
         if (group_enabled(group::NetProbeMetrics::Counters)) {
             target.second->attempts.to_prometheus(out, target_labels);
             target.second->successes.to_prometheus(out, target_labels);
+            target.second->connect_failures.to_prometheus(out, target_labels);
             target.second->dns_failures.to_prometheus(out, target_labels);
             target.second->timed_out.to_prometheus(out, target_labels);
         }
@@ -198,6 +200,7 @@ void NetProbeMetricsBucket::to_opentelemetry(metrics::v1::ScopeMetrics &scope, t
         if (group_enabled(group::NetProbeMetrics::Counters)) {
             target.second->attempts.to_opentelemetry(scope, start_ts, end_ts, target_labels);
             target.second->successes.to_opentelemetry(scope, start_ts, end_ts, target_labels);
+            target.second->connect_failures.to_opentelemetry(scope, start_ts, end_ts, target_labels);
             target.second->dns_failures.to_opentelemetry(scope, start_ts, end_ts, target_labels);
             target.second->timed_out.to_opentelemetry(scope, start_ts, end_ts, target_labels);
         }
@@ -252,6 +255,7 @@ void NetProbeMetricsBucket::to_json(json &j) const
         if (group_enabled(group::NetProbeMetrics::Counters)) {
             target.second->attempts.to_json(j["targets"][targetId]);
             target.second->successes.to_json(j["targets"][targetId]);
+            target.second->connect_failures.to_json(j["targets"][targetId]);
             target.second->dns_failures.to_json(j["targets"][targetId]);
             target.second->timed_out.to_json(j["targets"][targetId]);
         }
@@ -311,9 +315,12 @@ void NetProbeMetricsBucket::process_failure(ErrorType error, const std::string &
             break;
         case ErrorType::Timeout:
             ++_targets_metrics[target]->timed_out;
+            break;
         case ErrorType::SocketError:
         case ErrorType::InvalidIp:
-        case ErrorType::ConnectionFailure:
+        case ErrorType::ConnectFailure:
+            ++_targets_metrics[target]->connect_failures;
+            break;
         default:
             break;
         }
@@ -374,12 +381,14 @@ void NetProbeMetricsManager::process_netprobe_icmp(pcpp::IcmpLayer *layer, const
 
     if (layer->getMessageType() == pcpp::ICMP_ECHO_REQUEST) {
         if (auto request = layer->getEchoRequestData(); request != nullptr) {
-            _request_reply_manager->start_transaction((static_cast<uint32_t>(request->header->id) << 16) | request->header->sequence, {{stamp, {0, 0}}, target});
+            auto ping_id = (static_cast<uint32_t>(request->header->id) << 16) | request->header->sequence;
+            _request_reply_manager->start_transaction(std::to_string(ping_id), {{stamp, {0, 0}}, target});
         }
         live_bucket()->process_attempts(_deep_sampling_now, target);
     } else if (layer->getMessageType() == pcpp::ICMP_ECHO_REPLY) {
         if (auto reply = layer->getEchoReplyData(); reply != nullptr) {
-            auto xact = _request_reply_manager->maybe_end_transaction((static_cast<uint32_t>(reply->header->id) << 16) | reply->header->sequence, stamp);
+            auto ping_id = (static_cast<uint32_t>(reply->header->id) << 16) | reply->header->sequence;
+            auto xact = _request_reply_manager->maybe_end_transaction(std::to_string(ping_id), stamp);
             if (xact.first == Result::Valid) {
                 live_bucket()->new_transaction(_deep_sampling_now, xact.second);
             } else if (xact.first == Result::TimedOut) {
@@ -389,16 +398,16 @@ void NetProbeMetricsManager::process_netprobe_icmp(pcpp::IcmpLayer *layer, const
     }
 }
 
-void NetProbeMetricsManager::process_netprobe_tcp(uint32_t port, bool send, const std::string &target, timespec stamp)
+void NetProbeMetricsManager::process_netprobe_tcp(bool send, const std::string &target, timespec stamp)
 {
     // base event
     new_event(stamp);
 
     if (send) {
-        _request_reply_manager->start_transaction(port, {{stamp, {0, 0}}, target});
+        _request_reply_manager->start_transaction(target, {{stamp, {0, 0}}, target});
         live_bucket()->process_attempts(_deep_sampling_now, target);
     } else {
-        auto xact = _request_reply_manager->maybe_end_transaction(port, stamp);
+        auto xact = _request_reply_manager->maybe_end_transaction(target, stamp);
         if (xact.first == Result::Valid) {
             live_bucket()->new_transaction(_deep_sampling_now, xact.second);
         } else if (xact.first == Result::TimedOut) {

src/handlers/netprobe/NetProbeStreamHandler.h

@@ -49,6 +49,7 @@ struct Target {
     Counter successes;
     Counter minimum;
     Counter maximum;
+    Counter connect_failures;
     Counter dns_failures;
     Counter timed_out;
 
@@ -59,7 +60,8 @@ struct Target {
         , successes(NET_PROBE_SCHEMA, {"successes"}, "Total Net Probe successes")
         , minimum(NET_PROBE_SCHEMA, {"response_min_us"}, "Minimum response time measured in the reporting interval")
         , maximum(NET_PROBE_SCHEMA, {"response_max_us"}, "Maximum response time measured in the reporting interval")
-        , dns_failures(NET_PROBE_SCHEMA, {"dns_lookup_failures"}, "Total Net Probe failures when performed DNS lookup")
+        , connect_failures(NET_PROBE_SCHEMA, {"connect_failures"}, "Total Net Probe failures when performing a TCP socket connection")
+        , dns_failures(NET_PROBE_SCHEMA, {"dns_lookup_failures"}, "Total Net Probe failures when performing a DNS lookup")
         , timed_out(NET_PROBE_SCHEMA, {"packets_timeout"}, "Total Net Probe timeout transactions")
     {
     }
@@ -98,7 +100,7 @@ class NetProbeMetricsBucket final : public visor::AbstractMetricsBucket
 
 class NetProbeMetricsManager final : public visor::AbstractMetricsManager<NetProbeMetricsBucket>
 {
-    typedef TransactionManager<uint32_t, NetProbeTransaction, std::hash<uint32_t>> NetProbeTransactionManager;
+    typedef TransactionManager<std::string, NetProbeTransaction, std::hash<std::string>> NetProbeTransactionManager;
     std::unique_ptr<NetProbeTransactionManager> _request_reply_manager;
 
 public:
@@ -122,7 +124,7 @@ class NetProbeMetricsManager final : public visor::AbstractMetricsManager<NetPro
     void process_filtered(timespec stamp);
     void process_failure(ErrorType error, const std::string &target);
     void process_netprobe_icmp(pcpp::IcmpLayer *layer, const std::string &target, timespec stamp);
-    void process_netprobe_tcp(uint32_t port, bool send, const std::string &target, timespec stamp);
+    void process_netprobe_tcp(bool send, const std::string &target, timespec stamp);
 };
 
 class NetProbeStreamHandler final : public visor::StreamMetricsHandler<NetProbeMetricsManager>

src/inputs/netprobe/NetProbe.h

@@ -24,7 +24,7 @@ enum class ErrorType {
     SocketError,
     DnsLookupFailure,
     InvalidIp,
-    ConnectionFailure
+    ConnectFailure
 };
 
 enum class TestType {

src/inputs/netprobe/PingProbe.cpp

@@ -184,6 +184,9 @@ bool PingProbe::start(std::shared_ptr<uvw::Loop> io_loop)
         throw NetProbeException("PingProbe - unable to initialize AsyncHandle receiver");
     }
     _recv_handler->on<uvw::AsyncEvent>([this](const auto &, auto &) {
+        // note this processes received packets across ALL active ping probes (because of the single receiver thread)
+        // the expectation is that packets which did not originate from this probe will be ignored by the handler attached to this probe,
+        // since it did not originate from it
         for (auto &[packet, stamp] : PingReceiver::recv_packets) {
             _recv(packet, TestType::Ping, _name, stamp);
         }

src/inputs/netprobe/TcpProbe.cpp

@@ -31,44 +31,17 @@ bool TcpProbe::start(std::shared_ptr<uvw::Loop> io_loop)
     }
 
     _interval_timer->on<uvw::TimerEvent>([this](const auto &, auto &) {
-        _internal_sequence = 0;
-        _timeout_timer = _io_loop->resource<uvw::TimerHandle>();
-        if (!_timeout_timer) {
-            throw NetProbeException("Netprobe - unable to initialize timeout TimerHandle");
-        }
-
-        _timeout_timer->on<uvw::TimerEvent>([this](const auto &, auto &) {
-            _internal_sequence = _config.packets_per_test;
-            _fail(ErrorType::Timeout, TestType::Ping, _name);
-            if (_internal_timer) {
-                _internal_timer->stop();
-            }
-            _interval_timer->again();
-        });
 
         if (!_dns.empty()) {
             auto [ip, ipv4] = _resolve_dns();
             _ip_str = ip;
             _is_ipv4 = ipv4;
             if (_ip_str.empty()) {
-                _fail(ErrorType::DnsLookupFailure, TestType::Ping, _name);
+                _fail(ErrorType::DnsLookupFailure, TestType::TCP, _name);
                 return;
             }
         }
-
-        _internal_timer = _io_loop->resource<uvw::TimerHandle>();
-        _internal_timer->on<uvw::TimerEvent>([this](const auto &, auto &) {
-            if (_internal_sequence < _config.packets_per_test) {
-                _internal_sequence++;
-                _timeout_timer->stop();
-                _timeout_timer->start(uvw::TimerHandle::Time{_config.timeout_msec}, uvw::TimerHandle::Time{0});
-                _perform_tcp_process();
-            }
-        });
-        _timeout_timer->start(uvw::TimerHandle::Time{_config.timeout_msec}, uvw::TimerHandle::Time{0});
         _perform_tcp_process();
-        _internal_sequence++;
-        _internal_timer->start(uvw::TimerHandle::Time{_config.packets_interval_msec}, uvw::TimerHandle::Time{_config.packets_interval_msec});
     });
 
     _interval_timer->start(uvw::TimerHandle::Time{0}, uvw::TimerHandle::Time{_config.interval_msec});
@@ -80,33 +53,32 @@ void TcpProbe::_perform_tcp_process()
 {
     _client = _io_loop->resource<uvw::TCPHandle>();
     _client->on<uvw::ErrorEvent>([this](const auto &, auto &) {
-        _fail(ErrorType::ConnectionFailure, TestType::Ping, _name);
+        _fail(ErrorType::ConnectFailure, TestType::TCP, _name);
     });
     _client->once<uvw::CloseEvent>([this](const uvw::CloseEvent &, uvw::TCPHandle &) {
-        timespec stamp;
-        std::timespec_get(&stamp, TIME_UTC);
-        pcpp::Packet packet;
-        auto layer = pcpp::TcpLayer(static_cast<uint16_t>(_port), _client_port);
-        packet.addLayer(&layer);
-        _recv(packet, TestType::TCP, _name, stamp);
     });
-    _client->once<uvw::ShutdownEvent>([](const uvw::ShutdownEvent &, uvw::TCPHandle &handle) {
+    _client->once<uvw::ShutdownEvent>([this](const uvw::ShutdownEvent &, uvw::TCPHandle &handle) {
         handle.close();
     });
     _client->once<uvw::ConnectEvent>([this](const uvw::ConnectEvent &, uvw::TCPHandle &handle) {
         timespec stamp;
         std::timespec_get(&stamp, TIME_UTC);
-        _client_port = static_cast<uint16_t>(handle.sock().port);
         pcpp::Packet packet;
-        auto layer = pcpp::TcpLayer(_client_port, static_cast<uint16_t>(_port));
+        auto layer = pcpp::TcpLayer(0, static_cast<uint16_t>(_dst_port));
         packet.addLayer(&layer);
-        _send(packet, TestType::TCP, _name, stamp);
+        _recv(packet, TestType::TCP, _name, stamp);
         handle.shutdown();
     });
+    timespec stamp;
+    std::timespec_get(&stamp, TIME_UTC);
+    pcpp::Packet packet;
+    auto layer = pcpp::TcpLayer(0, static_cast<uint16_t>(_dst_port));
+    packet.addLayer(&layer);
+    _send(packet, TestType::TCP, _name, stamp);
     if (_is_ipv4) {
-        _client->connect<uvw::TCPHandle::IPv4>(_ip_str, _port);
+        _client->connect<uvw::TCPHandle::IPv4>(_ip_str, _dst_port);
     } else {
-        _client->connect<uvw::TCPHandle::IPv6>(_ip_str, _port);
+        _client->connect<uvw::TCPHandle::IPv6>(_ip_str, _dst_port);
     }
 }
 

src/inputs/netprobe/TcpProbe.h

@@ -11,24 +11,13 @@
 
 namespace visor::input::netprobe {
 
-/**
- * @class PingProbe
- * @brief PingProbe class used for sending ICMP Echo Requests.
- *
- *  This class is created for each specified target. However, it reuses a shared socket per thread (per UV_LOOP).
- *  I.e. each unique NetProbeInputStream with Ping Type will have a socket to send ICMP Echo Request.
- */
 class TcpProbe final : public NetProbe
 {
-    uint32_t _port;
-    uint16_t _client_port;
+    uint32_t _dst_port;
     bool _init{false};
     bool _is_ipv4{false};
-    uint16_t _internal_sequence{0};
     std::string _ip_str;
     std::shared_ptr<uvw::TimerHandle> _interval_timer;
-    std::shared_ptr<uvw::TimerHandle> _internal_timer;
-    std::shared_ptr<uvw::TimerHandle> _timeout_timer;
 
     std::shared_ptr<uvw::TCPHandle> _client;
 
@@ -37,8 +26,7 @@ class TcpProbe final : public NetProbe
 public:
     TcpProbe(uint16_t id, const std::string &name, const pcpp::IPAddress &ip, const std::string &dns, uint32_t port)
         : NetProbe(id, name, ip, dns)
-        , _port(port)
-        , _client_port(0){};
+        , _dst_port(port) {};
     ~TcpProbe() = default;
     bool start(std::shared_ptr<uvw::Loop> io_loop) override;
     bool stop() override;