Add test pass to run bpf_conformance with ELF

Signed-off-by: Alan Jowett <alanjo@microsoft.com>

Fix build on platforms without elf

Signed-off-by: Alan Jowett <alanjo@microsoft.com>

Skip ELF on aarch64 cross-compile

Signed-off-by: Alan Jowett <alanjo@microsoft.com>

CMakeLists.txt

@@ -21,6 +21,14 @@ include("cmake/settings.cmake")
 include("cmake/options.cmake")
 include("cmake/version.cmake")
 
+find_path(UBPF_ELF_H_PATH "elf.h" NO_CACHE)
+if(UBPF_ELF_H_PATH)
+  set(UBPF_HAS_ELF_H true)
+
+else()
+  message(WARNING "ubpf - elf.h was not found, disabling ELF support")
+endif()
+
 if(UBPF_ENABLE_TESTS)
   include("CTest")
 endif()

ubpf_plugin/CMakeLists.txt

@@ -80,4 +80,24 @@ foreach(file ${files})
     if(EXPECT_FAILURE)
         set_tests_properties(${file}-Interpreter PROPERTIES WILL_FAIL TRUE)
     endif()
+
+    if(UBPF_ELF_H_PATH AND NOT CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64)
+        add_test(
+            NAME ${file}-JIT-ELF
+            COMMAND ${BPF_CONFORMANCE_RUNNER} --elf true --test_file_path ${file} ${PLUGIN_JIT}
+        )
+
+        if(EXPECT_FAILURE)
+            set_tests_properties(${file}-JIT-ELF PROPERTIES WILL_FAIL TRUE)
+        endif()
+
+        add_test(
+            NAME ${file}-Interpreter-ELF
+            COMMAND ${BPF_CONFORMANCE_RUNNER} --elf true --test_file_path ${file} ${PLUGIN_INTERPRET}
+        )
+
+        if(EXPECT_FAILURE)
+            set_tests_properties(${file}-Interpreter-ELF PROPERTIES WILL_FAIL TRUE)
+        endif()
+    endif()
 endforeach()

ubpf_plugin/ubpf_plugin.cc

@@ -48,20 +48,6 @@ base16_decode(const std::string &input)
     return output;
 }
 
-/**
- * @brief Convert a vector of bytes to a vector of ebpf_inst.
- *
- * @param[in] bytes Vector of bytes.
- * @return Vector of ebpf_inst.
- */
-std::vector<ebpf_inst>
-bytes_to_ebpf_inst(std::vector<uint8_t> bytes)
-{
-    std::vector<ebpf_inst> instructions(bytes.size() / sizeof(ebpf_inst));
-    memcpy(instructions.data(), bytes.data(), bytes.size());
-    return instructions;
-}
-
 /**
  * @brief This program reads BPF instructions from stdin and memory contents from
  * the first agument. It then executes the BPF program and prints the
@@ -70,6 +56,7 @@ bytes_to_ebpf_inst(std::vector<uint8_t> bytes)
 int main(int argc, char **argv)
 {
     bool jit = false; // JIT == true, interpreter == false
+    bool is_elf = false;
     std::vector<std::string> args(argv, argv + argc);
     std::string program_string;
     std::string memory_string;
@@ -102,6 +89,12 @@ int main(int argc, char **argv)
         jit = false;
         args.erase(args.begin());
     }
+#if defined(UBPF_HAS_ELF_H)
+    if (args.size() > 0 && args[0] == "--elf") {
+        is_elf = true;
+        args.erase(args.begin());
+    }
+#endif
 
     if (args.size() > 0 && args[0].size() > 0)
     {
@@ -113,7 +106,7 @@ int main(int argc, char **argv)
         std::getline(std::cin, program_string);
     }
 
-    std::vector<ebpf_inst> program = bytes_to_ebpf_inst(base16_decode(program_string));
+    auto program_byte = base16_decode(program_string);
     std::vector<uint8_t> memory = base16_decode(memory_string);
 
     std::unique_ptr<ubpf_vm, decltype(&ubpf_destroy)> vm(ubpf_create(), ubpf_destroy);
@@ -140,12 +133,28 @@ int main(int argc, char **argv)
         return 1;
     }
 
-    if (ubpf_load(vm.get(), program.data(), static_cast<uint32_t>(program.size() * sizeof(ebpf_inst)), &error) != 0)
-    {
-        std::cerr << "Failed to load program: " << error << std::endl;
-        std::cout << "Failed to load code: " << error << std::endl;
-        free(error);
+    if (is_elf) {
+#if defined(UBPF_HAS_ELF_H)
+        if (ubpf_load_elf(vm.get(), program_byte.data(), static_cast<uint32_t>(program_byte.size()), &error) != 0)
+        {
+            std::cerr << "Failed to load program: " << error << std::endl;
+            std::cout << "Failed to load code: " << error << std::endl;
+            free(error);
+            return 1;
+        }
+#else
+        std::cerr << "ELF support not compiled in" << std::endl;
         return 1;
+#endif
+    }
+    else {
+        if (ubpf_load(vm.get(), program_byte.data(), static_cast<uint32_t>(program_byte.size()), &error) != 0)
+        {
+            std::cerr << "Failed to load program: " << error << std::endl;
+            std::cout << "Failed to load code: " << error << std::endl;
+            free(error);
+            return 1;
+        }
     }
 
     uint64_t actual_result;

vm/CMakeLists.txt

@@ -1,6 +1,5 @@
 # Copyright (c) 2022-present, IO Visor Project
 # SPDX-License-Identifier: Apache-2.0
-
 #
 # Copyright (c) 2022-present, IO Visor Project
 # All rights reserved.