implement custom protobuf debug string creation (#4532)

* implement custom protobuf debug log string creation * add version guards * add missing header * debian10 repository misses headers * clean up logging messages a bit * fix some more formatting on debug messages
2026-01-07 19:02:35 -08:00 · 2022-02-23 23:46:23 +01:00
parent eb3ce1fd7e
commit 7108eb42c8
10 changed files with 178 additions and 51 deletions
--- a/common/debug_pb_message.cpp
+++ b/common/debug_pb_message.cpp
@@ -0,0 +1,116 @@
+#include "debug_pb_message.h"
+
+#include "stringsizes.h"
+
+#include <QList>
+#include <QString>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/message.h>
+#include <google/protobuf/text_format.h>
+
+// google/protobuf/stubs/strutil.h is missing on some systems!
+namespace google
+{
+namespace protobuf
+{
+std::string CEscape(const std::string &src);
+} // namespace protobuf
+} // namespace google
+
+// FastFieldValuePrinter is added in protobuf 3.4, going out of our way to add the old FieldValuePrinter is not worth it
+#if GOOGLE_PROTOBUF_VERSION > 3004000
+
+// value printer to use for all values, will snip too long contents
+class LimitedPrinter : public ::google::protobuf::TextFormat::FastFieldValuePrinter
+{
+public:
+    void PrintString(const std::string &val,
+                     ::google::protobuf::TextFormat::BaseTextGenerator *generator) const override;
+};
+
+// value printer to use for specifc values, will expunge sensitive info
+class SafePrinter : public ::google::protobuf::TextFormat::FastFieldValuePrinter
+{
+public:
+    void PrintString(const std::string &val,
+                     ::google::protobuf::TextFormat::BaseTextGenerator *generator) const override;
+
+    static void applySafePrinter(const ::google::protobuf::Message &message,
+                                 ::google::protobuf::TextFormat::Printer &printer);
+};
+
+void LimitedPrinter::PrintString(const std::string &val,
+                                 ::google::protobuf::TextFormat::BaseTextGenerator *generator) const
+{
+    auto length = val.length();
+    if (length > MAX_TEXT_LENGTH) {
+        generator->PrintString("\"" + ::google::protobuf::CEscape(val.substr(0, MAX_NAME_LENGTH)) + "... ---snip--- (" +
+                               std::to_string(length) + " bytes total) \"");
+    } else {
+        ::google::protobuf::TextFormat::FastFieldValuePrinter::PrintString(val, generator);
+    }
+}
+
+void SafePrinter::PrintString(const std::string & /*val*/,
+                              ::google::protobuf::TextFormat::BaseTextGenerator *generator) const
+{
+    generator->PrintLiteral("\" ---value expunged--- \"");
+}
+
+void SafePrinter::applySafePrinter(const ::google::protobuf::Message &message,
+                                   ::google::protobuf::TextFormat::Printer &printer)
+{
+    const auto *reflection = message.GetReflection();
+    std::vector<const google::protobuf::FieldDescriptor *> fields;
+    reflection->ListFields(message, &fields);
+    for (const auto *field : fields) {
+        switch (field->cpp_type()) {
+            case ::google::protobuf::FieldDescriptor::CPPTYPE_STRING:
+                if (field->name().find("password") != std::string::npos) { // name contains password
+                    auto *safePrinter = new SafePrinter();
+                    if (!printer.RegisterFieldValuePrinter(field, safePrinter))
+                        delete safePrinter; // in case safePrinter has not been taken ownership of
+                }
+                break;
+            case google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE:
+                if (field->is_repeated()) {
+                    for (int i = 0; i < reflection->FieldSize(message, field); ++i) {
+                        applySafePrinter(reflection->GetRepeatedMessage(message, field, i), printer);
+                    }
+                } else {
+                    applySafePrinter(reflection->GetMessage(message, field), printer);
+                }
+                break;
+            default:
+                break;
+        }
+    }
+}
+#endif // GOOGLE_PROTOBUF_VERSION > 3004000
+
+QString getSafeDebugString(const ::google::protobuf::Message &message)
+{
+#if GOOGLE_PROTOBUF_VERSION > 3001000
+    auto size = message.ByteSizeLong();
+#else
+    auto size = message.ByteSize();
+#endif
+
+    ::google::protobuf::TextFormat::Printer printer;
+    printer.SetSingleLineMode(true); // compact mode
+    printer.SetExpandAny(true);      // prints all fields
+
+#if GOOGLE_PROTOBUF_VERSION > 3004000
+    // printer takes ownership of the LimitedPrinter and will delete it
+    printer.SetDefaultFieldValuePrinter(new LimitedPrinter());
+    // check field names an create SafePrinters for necessary fields
+    SafePrinter::applySafePrinter(message, printer);
+#else
+    // removing passwords from debug output will only be supported on newer protobuf versions
+    printer.SetTruncateStringFieldLongerThan(MAX_TEXT_LENGTH);
+#endif // GOOGLE_PROTOBUF_VERSION > 3004000
+
+    std::string debug_string;
+    printer.PrintToString(message, &debug_string);
+    return QString::number(size) + " bytes " + QString::fromStdString(debug_string);
+}