Add --verbose option to bpf2c (#4140)

Signed-off-by: Alan Jowett <[email protected]>
microsoft · Jan 18, 2025 · 5f890b1 · 5f890b1
1 parent 788e423
commit 5f890b1
Show file tree

Hide file tree

Showing 4 changed files with 66 additions and 2 deletions.
diff --git a/tests/bpf2c_tests/elf_bpf.cpp b/tests/bpf2c_tests/elf_bpf.cpp
@@ -319,3 +319,56 @@ TEST_CASE("bad malformed ELF", "[bpf2c_cli]")
         REQUIRE(err == expected_error);
     }
 }
+
+TEST_CASE("Verbose output", "[bpf2c_cli]")
+{
+    std::string non_verbose_error;
+    std::string verbose_error;
+    auto test = [&](bool verbose) -> std::string {
+        std::vector<const char*> argv;
+        argv.push_back("bpf2c.exe");
+        argv.push_back("--bpf");
+        argv.push_back("droppacket_unsafe.o");
+        if (verbose) {
+            argv.push_back("--verbose");
+        }
+        auto [out, err, result_value] = run_test_main(argv);
+        REQUIRE(result_value != 0);
+        REQUIRE(!err.empty());
+        REQUIRE(err.find("Verification failed for DropPacket with error Verification failed") != std::string::npos);
+        return err;
+    };
+
+    non_verbose_error = test(false);
+    verbose_error = test(true);
+
+    REQUIRE(non_verbose_error != verbose_error);
+    REQUIRE(non_verbose_error.length() < verbose_error.length());
+
+    // Count Pre-Invariant and Post-Invariant lines in the verbose output.
+    int pre_invariant = 0;
+    int post_invariant = 0;
+    std::istringstream verbose_stream(verbose_error);
+    std::string line;
+    while (std::getline(verbose_stream, line)) {
+        if (line.find("Pre-invariant") != std::string::npos) {
+            pre_invariant++;
+        }
+        if (line.find("Post-invariant") != std::string::npos) {
+            post_invariant++;
+        }
+    }
+
+    REQUIRE(pre_invariant == 25);
+    REQUIRE(post_invariant == 25);
+
+    // Check to make sure that the verbose flag doesn't cause verification to fail.
+    std::vector<const char*> argv;
+    argv.push_back("bpf2c.exe");
+    argv.push_back("--bpf");
+    argv.push_back("droppacket.o");
+    argv.push_back("--verbose");
+    auto [out, err, result_value] = run_test_main(argv);
+    REQUIRE(result_value == 0);
+    REQUIRE(err.empty());
+}
diff --git a/tests/sample/sample.vcxproj b/tests/sample/sample.vcxproj
@@ -303,7 +303,7 @@
       <Command>
         $(ClangExec) $(ClangFlags) -I../xdp -I../socket -I./ext/inc -I../../netebpfext -I. -I../../undocked/tests/sample/ext/inc -c undocked\%(Filename).c -o $(OutputPath)%(Filename).o
         pushd $(OutDir)
-        powershell -NonInteractive -ExecutionPolicy Unrestricted .\Convert-BpfToNative.ps1 -FileName %(Filename) -IncludeDir $(SolutionDir)\include -Platform $(Platform) -Packages $(SolutionDir)\packages -Configuration $(KernelConfiguration) -KernelMode $true
+        powershell -NonInteractive -ExecutionPolicy Unrestricted .\Convert-BpfToNative.ps1 -FileName %(Filename) -IncludeDir $(SolutionDir)\include -Platform $(Platform) -Packages $(SolutionDir)\packages -Configuration $(KernelConfiguration) -KernelMode $true -Verbose
         powershell -NonInteractive -ExecutionPolicy Unrestricted .\Convert-BpfToNative.ps1 -FileName %(Filename) -IncludeDir $(SolutionDir)\include -Platform $(Platform) -Packages $(SolutionDir)\packages -Configuration $(Configuration) -KernelMode $false
         popd
       </Command>

diff --git a/tools/bpf2c/Convert-BpfToNative.ps1.template b/tools/bpf2c/Convert-BpfToNative.ps1.template
@@ -122,6 +122,10 @@ if ($PSBoundParameters.ContainsKey("Type")) {
     $AdditionalOptions += " --type $Type"
 }
 
+if ($VerbosePreference -eq "Continue") {
+    $AdditionalOptions += " --verbose"
+}
+
 msbuild /p:BinDir="$BinDir\" /p:OutDir="$OutDir\" /p:IncludeDir="$IncludeDir" /p:Configuration="$Configuration" /p:Platform="$Platform" /p:FileName="$FileName" /p:AdditionalOptions="$AdditionalOptions" /p:ResourceFile="$ResourceFile" /p:Packages="$Packages" $ProjectFile
 
 if ($LASTEXITCODE -ne 0) {

diff --git a/tools/bpf2c/bpf2c.cpp b/tools/bpf2c/bpf2c.cpp
@@ -143,6 +143,7 @@ main(int argc, char** argv)
         std::string output_file_name;
         std::string type_string = "";
         std::string hash_algorithm = EBPF_HASH_ALGORITHM;
+        bool verbose = false;
         std::vector<std::string> parameters(argv + 1, argv + argc);
         auto iter = parameters.begin();
         auto iter_end = parameters.end();
@@ -227,6 +228,12 @@ main(int argc, char** argv)
                   }
                   return false;
               }}},
+            {"--verbose",
+             {"Show verbose failure information",
+              [&]() {
+                  verbose = true;
+                  return true;
+              }}},
         };
 
         for (; iter != iter_end; ++iter) {
@@ -305,7 +312,7 @@ main(int argc, char** argv)
                     program->section_name,
                     program->program_name,
                     (global_program_type_set) ? &program_type : &program->program_type,
-                    EBPF_VERIFICATION_VERBOSITY_NORMAL,
+                    verbose ? EBPF_VERIFICATION_VERBOSITY_INFORMATIONAL : EBPF_VERIFICATION_VERBOSITY_NORMAL,
                     &report,
                     &error_message,
                     &stats) != 0) {