1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "dlfcn_symlink_support.h" 18 19 #include <gtest/gtest.h> 20 21 #include <dlfcn.h> 22 #include <libgen.h> 23 #include <link.h> 24 #include <unistd.h> 25 26 #include <android-base/strings.h> 27 28 #include <algorithm> 29 #include <string> 30 #include <vector> 31 32 static const constexpr char* source_file_name = "libdlext_test.so"; 33 static const constexpr char* symlink_name_prefix = "libdlext_test_"; 34 35 static int dl_callback(struct dl_phdr_info *info, size_t /* size */, void *data) { 36 // The case when path is not absolute and is equal to source_file_name 37 // is disregarded intentionally since in bionic dlpi_name should always 38 // be realpath to a shared object. 39 const std::string suffix = std::string("/") + source_file_name; 40 41 // TODO (dimitry): remove this check once fake libdl.so is gone 42 if (info->dlpi_name == nullptr) { 43 // This is linker imposing as libdl.so - skip it 44 return 0; 45 } 46 47 if (android::base::EndsWith(info->dlpi_name, suffix)) { 48 std::string* path = reinterpret_cast<std::string*>(data); 49 *path = info->dlpi_name; 50 return 1; // found 51 } 52 53 return 0; 54 } 55 56 void create_dlfcn_test_symlink(const char* suffix, std::string* result) { 57 void* handle = dlopen(source_file_name, RTLD_NOW); 58 std::string source_file_path; 59 60 ASSERT_TRUE(handle != nullptr) << dlerror(); 61 ASSERT_TRUE(dl_iterate_phdr(dl_callback, &source_file_path) == 1) 62 << "dl_phdr_info for \"" << source_file_name << "\" was not found."; 63 64 dlclose(handle); 65 std::vector<char> buf; 66 std::copy(source_file_path.begin(), source_file_path.end(), std::back_inserter(buf)); 67 buf.push_back('\0'); 68 69 std::string path_dir = dirname(&buf[0]); 70 std::string link_path = path_dir + "/" + symlink_name_prefix + suffix + ".so"; 71 72 ASSERT_TRUE(symlink(source_file_path.c_str(), link_path.c_str()) == 0) << strerror(errno); 73 *result = link_path; 74 } 75 76 void remove_dlfcn_test_symlink(const std::string& path) { 77 ASSERT_TRUE(unlink(path.c_str()) == 0) << strerror(errno); 78 } 79
