Merge "libcutils: fs_config: fix "system/<partition>/" aliasing" (cd3584e9) · Commits · e / os / android_system_core

libcutils/fs_config.cpp

+19 −20

Original line number	Diff line number	Diff line
		@@ -266,14 +266,27 @@ static bool is_partition(const char* path, size_t len) {
		return false;
		}

		static inline bool prefix_cmp(bool partial, const char* prefix, size_t len, const char* path,
		size_t plen) {
		return ((partial && plen >= len) \|\| (plen == len)) && !strncmp(prefix, path, len);
		}

		// alias prefixes of "<partition>/<stuff>" to "system/<partition>/<stuff>" or
		// "system/<partition>/<stuff>" to "<partition>/<stuff>"
		static bool prefix_cmp(const char* prefix, const char* path, size_t len) {
		if (!strncmp(prefix, path, len)) return true;
		static bool fs_config_cmp(bool partial, const char* prefix, size_t len, const char* path,
		size_t plen) {
		// If name ends in * then allow partial matches.
		if (!partial && prefix[len - 1] == '*') {
		len--;
		partial = true;
		}

		if (prefix_cmp(partial, prefix, len, path, plen)) return true;

		static const char system[] = "system/";
		if (!strncmp(path, system, strlen(system))) {
		path += strlen(system);
		plen -= strlen(system);
		} else if (len <= strlen(system)) {
		return false;
		} else if (strncmp(prefix, system, strlen(system))) {
		@@ -282,25 +295,11 @@ static bool prefix_cmp(const char* prefix, const char* path, size_t len) {
		prefix += strlen(system);
		len -= strlen(system);
		}
		return is_partition(prefix, len) && !strncmp(prefix, path, len);
		}

		static bool fs_config_cmp(bool dir, const char* prefix, size_t len, const char* path, size_t plen) {
		if (dir) {
		if (plen < len) {
		return false;
		}
		} else {
		// If name ends in * then allow partial matches.
		if (prefix[len - 1] == '*') {
		return prefix_cmp(prefix, path, len - 1);
		}
		if (plen != len) {
		return false;
		}
		}
		return prefix_cmp(prefix, path, len);
		return is_partition(prefix, len) && prefix_cmp(partial, prefix, len, path, plen);
		}
		#ifndef __ANDROID_VNDK__
		auto __for_testing_only__fs_config_cmp = fs_config_cmp;
		#endif

		void fs_config(const char* path, int dir, const char* target_out_path, unsigned* uid, unsigned* gid,
		unsigned* mode, uint64_t* capabilities) {

libcutils/tests/fs_config.cpp

+47 −0

Original line number	Diff line number	Diff line
		@@ -29,12 +29,39 @@

		extern const fs_path_config* __for_testing_only__android_dirs;
		extern const fs_path_config* __for_testing_only__android_files;
		extern bool (__for_testing_only__fs_config_cmp)(bool, const char, size_t, const char*, size_t);

		// Maximum entries in system/core/libcutils/fs_config.cpp:android_* before we
		// hit a nullptr termination, before we declare the list is just too big or
		// could be missing the nullptr.
		static constexpr size_t max_idx = 4096;

		static const struct fs_config_cmp_test {
		bool dir;
		const char* prefix;
		const char* path;
		bool match;
		} fs_config_cmp_tests[] = {
		// clang-format off
		{ true, "system/lib", "system/lib/hw", true },
		{ true, "vendor/lib", "system/vendor/lib/hw", true },
		{ true, "system/vendor/lib", "vendor/lib/hw", true },
		{ true, "system/vendor/lib", "system/vendor/lib/hw", true },
		{ false, "vendor/bin/wifi", "system/vendor/bin/w", false },
		{ false, "vendor/bin/wifi", "system/vendor/bin/wifi", true },
		{ false, "vendor/bin/wifi", "system/vendor/bin/wifi2", false },
		{ false, "system/vendor/bin/wifi", "system/vendor/bin/wifi", true, },
		{ false, "odm/bin/wifi", "system/odm/bin/wifi", true },
		{ false, "oem/bin/wifi", "system/oem/bin/wifi", true },
		{ false, "data/bin/wifi", "system/data/bin/wifi", false },
		{ false, "system/bin/*", "system/bin/wifi", true },
		{ false, "vendor/bin/*", "system/vendor/bin/wifi", true },
		{ false, "system/bin/*", "system/bin", false },
		{ false, "system/vendor/bin/*", "vendor/bin/wifi", true },
		{ false, NULL, NULL, false },
		// clang-format on
		};

		static bool check_unique(std::vector<const char*>& paths, const std::string& config_name,
		const std::string& prefix) {
		bool retval = false;
		@@ -106,6 +133,22 @@ static bool check_unique(const fs_path_config* paths, const char* type_name,
		return check_unique(paths_tmp, config, prefix) \|\| retval;
		}

		static bool check_fs_config_cmp(const fs_config_cmp_test* tests) {
		bool match, retval = false;
		for (size_t idx = 0; tests[idx].prefix; ++idx) {
		match = __for_testing_only__fs_config_cmp(tests[idx].dir, tests[idx].prefix,
		strlen(tests[idx].prefix), tests[idx].path,
		strlen(tests[idx].path));
		if (match != tests[idx].match) {
		GTEST_LOG_(ERROR) << tests[idx].path << (match ? " matched " : " didn't match ")
		<< tests[idx].prefix;
		retval = true;
		break;
		}
		}
		return retval;
		}

		#define endof(pointer, field) (offsetof(typeof(*(pointer)), field) + sizeof((pointer)->field))

		static bool check_unique(const std::string& config, const std::string& prefix) {
		@@ -199,3 +242,7 @@ TEST(fs_config, odm_dirs_alias) {
		TEST(fs_config, odm_files_alias) {
		check_two(__for_testing_only__android_files, "files", "odm/");
		}

		TEST(fs_config, system_alias) {
		EXPECT_FALSE(check_fs_config_cmp(fs_config_cmp_tests));
		}