Fix linking against stdc++ and fix verbosity

Author: cmeister2

curl_fuzzer.cc

@@ -28,8 +28,53 @@
 #include "curl_fuzzer.h"
 #include "curl_fuzzer_scenario.h"
 
+#if defined(__has_include)
+#  if __has_include(<sanitizer/lsan_interface.h>)
+#    include <sanitizer/lsan_interface.h>
+#    define CURL_FUZZER_HAS_LSAN 1
+#  else
+#    define CURL_FUZZER_HAS_LSAN 0
+#  endif
+#else
+#  define CURL_FUZZER_HAS_LSAN 0
+#endif
+
 #include <libprotobuf-mutator/src/libfuzzer/libfuzzer_macro.h>
 
+namespace {
+
+bool ShouldRunPerScenarioLeakCheck()
+{
+  static int cached = -1;
+  if(cached == -1) {
+    const char *env = getenv("FUZZ_PER_SCENARIO_LEAK_CHECK");
+    cached = (env != NULL && env[0] != '\0' && strcmp(env, "0") != 0) ? 1 : 0;
+  }
+  return cached == 1;
+}
+
+bool FuzzOptionIsSet(const FUZZ_DATA *fuzz, CURLoption opt)
+{
+  size_t idx = static_cast<size_t>(opt % 1000);
+  if(idx >= FUZZ_CURLOPT_TRACKER_SPACE) {
+    return false;
+  }
+  return fuzz->options[idx] != 0;
+}
+
+void EnforceScenarioLeakCleanliness()
+{
+#if CURL_FUZZER_HAS_LSAN
+  if(ShouldRunPerScenarioLeakCheck()) {
+    __lsan_do_leak_check();
+  }
+#else
+  (void)ShouldRunPerScenarioLeakCheck();
+#endif
+}
+
+} // namespace
+
 DEFINE_BINARY_PROTO_FUZZER(const curl::fuzzer::proto::Scenario &scenario)
 {
   CurlFuzzerRunScenario(scenario);
@@ -54,6 +99,14 @@ int CurlFuzzerRunScenario(const curl::fuzzer::proto::Scenario &scenario)
     FV_PRINTF(&fuzz, "SCENARIO: ApplyScenario failed with rc=%d\n", rc);
     goto EXIT_LABEL;
   }
+
+  if(!FuzzOptionIsSet(&fuzz, CURLOPT_URL)) {
+    if(fuzz.verbose) {
+      FV_PRINTF(&fuzz, "SCENARIO: skipping transfer due to missing CURLOPT_URL\n");
+    }
+    goto EXIT_LABEL;
+  }
+
   FV_PRINTF(&fuzz,
             "SCENARIO: successfully applied scenario, starting transfer\n");
 
@@ -90,6 +143,7 @@ int CurlFuzzerRunScenario(const curl::fuzzer::proto::Scenario &scenario)
 EXIT_LABEL:
 
   fuzz_terminate_fuzz_data(&fuzz);
+  EnforceScenarioLeakCleanliness();
 
   /* This function must always return 0. Non-zero codes are reserved. */
   return 0;
@@ -282,6 +336,7 @@ void fuzz_terminate_fuzz_data(FUZZ_DATA *fuzz)
     curl_formfree(fuzz->httppost);
     fuzz->httppost = NULL;
   }
+  fuzz->last_post_part = NULL;
 
   // free after httppost and last_post_part.
   if (fuzz->post_body != NULL) {