fix: fix possible unwrappered exception throwing when sw8 contains illegal span id (#120)

Signed-off-by: wangbaiping <[email protected]>

Author: wbpcode

source/propagation_impl.cc

@@ -18,6 +18,7 @@
 #include <memory>
 
 #include "absl/memory/memory.h"
+#include "absl/strings/numbers.h"
 #include "absl/strings/string_view.h"
 #include "cpp2sky/exception.h"
 #include "source/utils/base64.h"
@@ -60,15 +61,20 @@ SpanContextImpl::SpanContextImpl(absl::string_view header_value) {
 
   if (fields[0] != "0" && fields[0] != "1") {
     throw TracerException(
-        "Invalid span context format. sample field must be 0 or 1.");
+        "Invalid span context format. Sample field must be 0 or 1.");
   }
 
   // Sampling is always true
   sample_ = true;
   trace_id_ = Base64::decodeWithoutPadding(absl::string_view(fields[1]));
   trace_segment_id_ =
       Base64::decodeWithoutPadding(absl::string_view(fields[2]));
-  span_id_ = std::stoi(fields[3]);
+
+  if (!absl::SimpleAtoi(fields[3], &span_id_)) {
+    throw TracerException(
+        "Invalid span id format. Span id field must be integer number.");
+  }
+
   service_ = Base64::decodeWithoutPadding(absl::string_view(fields[4]));
   service_instance_ =
       Base64::decodeWithoutPadding(absl::string_view(fields[5]));

source/propagation_impl.h

@@ -42,10 +42,10 @@ class SpanContextImpl : public SpanContext {
  private:
   // Based on
   // https://github.com/apache/skywalking/blob/master/docs/en/protocols/Skywalking-Cross-Process-Propagation-Headers-Protocol-v3.md
-  bool sample_ = true;
+  bool sample_{true};
   std::string trace_id_;
   std::string trace_segment_id_;
-  int32_t span_id_;
+  int32_t span_id_{};
   std::string service_;
   std::string service_instance_;
   std::string endpoint_;

test/propagation_test.cc

@@ -36,6 +36,10 @@ static constexpr absl::string_view invalid_sample =
     "3-MQ==-NQ==-3-bWVzaA==-aW5zdGFuY2U=-L2FwaS92MS9oZWFsdGg=-"
     "ZXhhbXBsZS5jb206ODA4MA==";
 
+static constexpr absl::string_view invalid_span_id =
+    "1-MQ==-NQ==-abc-bWVzaA==-aW5zdGFuY2U=-L2FwaS92MS9oZWFsdGg=-"
+    "ZXhhbXBsZS5jb206ODA4MA==";
+
 TEST(TestSpanContext, Basic) {
   auto data = std::string(sample.data());
   SpanContextImpl sc(data);
@@ -62,6 +66,7 @@ TEST(TestSpanContext, MalformedSpanContext) {
     auto data = std::string(invalid_sample.data());
     EXPECT_THROW(SpanContextImpl{data}, TracerException);
   }
+  { EXPECT_THROW(SpanContextImpl{invalid_span_id}, TracerException); }
 }
 
 }  // namespace cpp2sky