Saving work on commsdsl2wireshark dissector.

Author: arobenko

app/commsdsl2wireshark/src/Wireshark.cpp

@@ -15,6 +15,7 @@
 
 #include "Wireshark.h"
 
+#include "WiresharkFrame.h"
 #include "WiresharkGenerator.h"
 #include "WiresharkSchema.h"
 
@@ -123,13 +124,6 @@ std::string Wireshark::wiresharkDissectFuncInternal() const
     const std::string Templ =
         "-- Main Dissector Entry Point\n"
         "function #^#NAME#$#.dissector(tvb, pinfo, tree)\n"
-        "    #^#REPLACE#$#\n"
-        "    if tvb:len() == 0 then\n"
-        "        return\n"
-        "    end\n"
-        "\n"
-        "    pinfo.cols.protocol = #^#NAME#$#.name\n"
-        "\n"
         "    #^#BODY#$#\n"
         "end\n"
         ;
@@ -140,11 +134,11 @@ std::string Wireshark::wiresharkDissectFuncInternal() const
 
     util::GenReplacementMap repl = {
         {"NAME", wiresharkProtocolObjName(m_wiresharkGenerator)},
-        {"REPLACE", std::move(replaceCode)},
+        {"BODY", std::move(replaceCode)},
     };
 
     if (!bodyReplaced) {
-        // TODO: Add frame function
+        repl["BODY"] = wiresharkDissectFuncBodyInternal();
     }
 
     return util::genProcessTemplate(Templ, repl);
@@ -186,5 +180,56 @@ std::string Wireshark::wiresharkCodeInternal() const
     return util::genStrListToString(elems, "\n", "");
 }
 
+std::string Wireshark::wiresharkDissectFuncBodyInternal() const
+{
+    util::GenStringsList elems;
+    auto frames = m_wiresharkGenerator.genProtocolSchema().genGetAllFrames();
+    for (auto* f : frames) {
+        assert(f != nullptr);
+        auto& wiresharkFrame = WiresharkFrame::wiresharkCast(*f);
+        static const std::string FrameTempl =
+            "result, next_offset = #^#NAME#$#(tvb, tree)\n"
+            "if result then\n"
+            "    break\n"
+            "end\n"
+        ;
+
+        util::GenReplacementMap frameRepl = {
+            {"NAME", wiresharkFrame.wiresharkDissectName()}
+        };
+
+        elems.push_back(util::genProcessTemplate(FrameTempl, frameRepl));
+    }
+
+    const std::string Templ =
+        "if tvb:len() == 0 then\n"
+        "    return\n"
+        "end\n"
+        "\n"
+        "pinfo.cols.protocol = #^#NAME#$#.name\n"
+        "\n"
+        "local result = false\n"
+        "local next_offset = 0\n"
+        "repeat\n"
+        "    #^#FRAMES#$#\n"
+        "until true\n"
+        "\n"
+        "if not result then\n"
+        "   return\n"
+        "end\n"
+        "\n"
+        "if next_offset < tvb:len() then\n"
+        "    pinfo.desegment_offset = next_offset\n"
+        "    pinfo.desegment_len = DESEGMENT_ONE_MORE_SEGMENT\n"
+        "end\n"
+    ;
+
+    util:: GenReplacementMap repl = {
+        {"FRAMES", util::genStrListToString(elems, "\n", "")}
+    };
+
+    return util::genProcessTemplate(Templ, repl);
+}
+
 } // namespace commsdsl2wireshark
 

app/commsdsl2wireshark/src/Wireshark.h

@@ -39,6 +39,7 @@ class Wireshark
     std::string wiresharkDissectFuncInternal() const;
     std::string wiresharkFieldsRegistrationInternal() const;
     std::string wiresharkCodeInternal() const;
+    std::string wiresharkDissectFuncBodyInternal() const;
 
     WiresharkGenerator& m_wiresharkGenerator;
 };

app/commsdsl2wireshark/src/WiresharkFrame.cpp

@@ -16,10 +16,15 @@
 #include "WiresharkFrame.h"
 
 #include "WiresharkGenerator.h"
+#include "WiresharkInterface.h"
+#include "WiresharkNamespace.h"
 
 #include "commsdsl/gen/strings.h"
 #include "commsdsl/gen/util.h"
 
+#include <algorithm>
+#include <cassert>
+
 namespace strings = commsdsl::gen::strings;
 namespace util = commsdsl::gen::util;
 
@@ -94,8 +99,21 @@ bool WiresharkFrame::genPrepareImpl()
         m_wiresharkLayers.push_back(WiresharkLayer::wiresharkCast(l));
     }
 
-    // TODO: validate frame
-    m_validFrame = true;
+    auto* iFace = wiresharkInterfaceInternal();
+    do {
+        if (iFace == nullptr) {
+            genGenerator().genLogger().genDebug("No valid interface for frame " + genName());
+            break;
+        }
+
+        m_validFrame =
+            std::all_of(
+                m_wiresharkLayers.begin(), m_wiresharkLayers.end(),
+                [iFace](auto* l)
+                {
+                    return l->wiresharkIsInterfaceSupported(*iFace);
+                });
+    } while (false);
     return true;
 }
 
@@ -120,4 +138,13 @@ std::string WiresharkFrame::wiresharkLayersDissectCodeInternal() const
     return util::genStrListToString(layers, "\n", "\n");
 }
 
+const WiresharkInterface* WiresharkFrame::wiresharkInterfaceInternal() const
+{
+    auto* parent = genGetParent();
+    assert(parent != nullptr);
+    assert(parent->genElemType() == commsdsl::gen::GenElem::GenType_Namespace);
+    auto* parentNs = WiresharkNamespace::wiresharkCast(static_cast<const commsdsl::gen::GenNamespace*>(parent));
+    return parentNs->wiresharkInterface();
+}
+
 } // namespace commsdsl2wireshark

app/commsdsl2wireshark/src/WiresharkFrame.h

@@ -23,6 +23,7 @@ namespace commsdsl2wireshark
 {
 
 class WiresharkGenerator;
+class WiresharkInterface;
 class WiresharkFrame final : public commsdsl::gen::GenFrame
 {
     using GenBase = commsdsl::gen::GenFrame;
@@ -55,6 +56,7 @@ class WiresharkFrame final : public commsdsl::gen::GenFrame
 private:
     std::string wiresharkDissectBodyInternal() const;
     std::string wiresharkLayersDissectCodeInternal() const;
+    const WiresharkInterface* wiresharkInterfaceInternal() const;
 
     WiresharkLayersAccessList m_wiresharkLayers;
     bool m_validFrame = false;

app/commsdsl2wireshark/src/WiresharkLayer.cpp

@@ -101,6 +101,11 @@ std::string WiresharkLayer::wiresharkDissectCode() const
     return util::genProcessTemplate(Templ, repl);
 }
 
+bool WiresharkLayer::wiresharkIsInterfaceSupported(const WiresharkInterface& iFace) const
+{
+    return wiresharkIsInterfaceSupportedImpl(iFace);
+}
+
 std::string WiresharkLayer::wiresharkDissectBodyImpl() const
 {
     auto* field = WiresharkField::wiresharkCast(m_genLayer.genMemberField());
@@ -123,6 +128,11 @@ std::string WiresharkLayer::wiresharkDissectBodyImpl() const
     return util::genProcessTemplate(Templ, repl);
 }
 
+bool WiresharkLayer::wiresharkIsInterfaceSupportedImpl([[maybe_unused]] const WiresharkInterface& iFace) const
+{
+    return true;
+}
+
 std::string WiresharkLayer::wiresharkFieldDissectCodeInternal() const
 {
     auto* field = WiresharkField::wiresharkCast(m_genLayer.genMemberField());

app/commsdsl2wireshark/src/WiresharkLayer.h

@@ -22,6 +22,7 @@
 namespace commsdsl2wireshark
 {
 
+class WiresharkInterface;
 class WiresharkLayer
 {
 public:
@@ -46,8 +47,11 @@ class WiresharkLayer
     std::string wiresharkDissectName() const;
     std::string wiresharkDissectCode() const;
 
+    bool wiresharkIsInterfaceSupported(const WiresharkInterface& iFace) const;
+
 protected:
     virtual std::string wiresharkDissectBodyImpl() const;
+    virtual bool wiresharkIsInterfaceSupportedImpl(const WiresharkInterface& iFace) const;
 
 private:
     std::string wiresharkFieldDissectCodeInternal() const;

app/commsdsl2wireshark/src/WiresharkValueLayer.cpp

@@ -16,6 +16,7 @@
 #include "WiresharkValueLayer.h"
 
 #include "WiresharkGenerator.h"
+#include "WiresharkInterface.h"
 
 namespace commsdsl2wireshark
 {
@@ -26,4 +27,9 @@ WiresharkValueLayer::WiresharkValueLayer(WiresharkGenerator& generator, ParseLay
 {
 }
 
+bool WiresharkValueLayer::wiresharkIsInterfaceSupportedImpl(const WiresharkInterface& iFace) const
+{
+    return genIsInterfaceSupported(&iFace);
+}
+
 } // namespace commsdsl2wireshark

app/commsdsl2wireshark/src/WiresharkValueLayer.h

@@ -33,6 +33,9 @@ class WiresharkValueLayer final : public commsdsl::gen::GenValueLayer, public Wi
     using GenElem = commsdsl::gen::GenElem;
 
     WiresharkValueLayer(WiresharkGenerator& generator, ParseLayer parseObj, GenElem* parent);
+
+protected:
+    virtual bool wiresharkIsInterfaceSupportedImpl(const WiresharkInterface& iFace) const override;
 };
 
 } // namespace commsdsl2wireshark