Revert "Revert "Add derive_gid flag for mounting sdcardfs"" (ac8dc7e7) · Commits · e / os / android_system_core

sdcard/sdcard.cpp

+40 −20

Original line number	Diff line number	Diff line
		@@ -317,17 +317,31 @@ static void run(const char* source_path, const char* label, uid_t uid,
		LOG(FATAL) << "terminated prematurely";
		}

		static bool sdcardfs_setup(const std::string& source_path, const std::string& dest_path, uid_t fsuid,
		gid_t fsgid, bool multi_user, userid_t userid, gid_t gid, mode_t mask) {
		std::string opts = android::base::StringPrintf("fsuid=%d,fsgid=%d,%smask=%d,userid=%d,gid=%d",
		fsuid, fsgid, multi_user?"multiuser,":"", mask, userid, gid);
		static bool sdcardfs_setup(const std::string& source_path, const std::string& dest_path,
		uid_t fsuid, gid_t fsgid, bool multi_user, userid_t userid, gid_t gid,
		mode_t mask, bool derive_gid) {
		std::string opts = android::base::StringPrintf(
		"fsuid=%d,fsgid=%d,%s%smask=%d,userid=%d,gid=%d", fsuid, fsgid,
		multi_user ? "multiuser," : "", derive_gid ? "derive_gid," : "", mask, userid, gid);

		if (mount(source_path.c_str(), dest_path.c_str(), "sdcardfs",
		MS_NOSUID \| MS_NODEV \| MS_NOEXEC \| MS_NOATIME, opts.c_str()) == -1) {
		if (derive_gid) {
		PLOG(ERROR) << "trying to mount sdcardfs filesystem without derive_gid";
		/* Maybe this isn't supported on this kernel. Try without. */
		opts = android::base::StringPrintf("fsuid=%d,fsgid=%d,%smask=%d,userid=%d,gid=%d",
		fsuid, fsgid, multi_user ? "multiuser," : "", mask,
		userid, gid);
		if (mount(source_path.c_str(), dest_path.c_str(), "sdcardfs",
		MS_NOSUID \| MS_NODEV \| MS_NOEXEC \| MS_NOATIME, opts.c_str()) == -1) {
		PLOG(ERROR) << "failed to mount sdcardfs filesystem";
		return false;
		}

		} else {
		PLOG(ERROR) << "failed to mount sdcardfs filesystem";
		return false;
		}
		}
		return true;
		}

		@@ -353,7 +367,8 @@ static bool sdcardfs_setup_bind_remount(const std::string& source_path, const st
		}

		static void run_sdcardfs(const std::string& source_path, const std::string& label, uid_t uid,
		gid_t gid, userid_t userid, bool multi_user, bool full_write) {
		gid_t gid, userid_t userid, bool multi_user, bool full_write,
		bool derive_gid) {
		std::string dest_path_default = "/mnt/runtime/default/" + label;
		std::string dest_path_read = "/mnt/runtime/read/" + label;
		std::string dest_path_write = "/mnt/runtime/write/" + label;
		@@ -363,10 +378,10 @@ static void run_sdcardfs(const std::string& source_path, const std::string& labe
		// Multi-user storage is fully isolated per user, so "other"
		// permissions are completely masked off.
		if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
		AID_SDCARD_RW, 0006)
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY, 0027)
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write,
		AID_EVERYBODY, full_write ? 0007 : 0027)) {
		AID_SDCARD_RW, 0006, derive_gid) \|\|
		!sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY, 0027) \|\|
		!sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
		full_write ? 0007 : 0027)) {
		LOG(FATAL) << "failed to sdcardfs_setup";
		}
		} else {
		@@ -374,11 +389,11 @@ static void run_sdcardfs(const std::string& source_path, const std::string& labe
		// the Android directories are masked off to a single user
		// deep inside attr_from_stat().
		if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
		AID_SDCARD_RW, 0006)
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read,
		AID_EVERYBODY, full_write ? 0027 : 0022)
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write,
		AID_EVERYBODY, full_write ? 0007 : 0022)) {
		AID_SDCARD_RW, 0006, derive_gid) \|\|
		!sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY,
		full_write ? 0027 : 0022) \|\|
		!sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
		full_write ? 0007 : 0022)) {
		LOG(FATAL) << "failed to sdcardfs_setup";
		}
		}
		@@ -435,7 +450,8 @@ static int usage() {
		<< " -g: specify GID to run as"
		<< " -U: specify user ID that owns device"
		<< " -m: source_path is multi-user"
		<< " -w: runtime write mount has full write access";
		<< " -w: runtime write mount has full write access"
		<< " -P preserve owners on the lower file system";
		return 1;
		}

		@@ -447,12 +463,13 @@ int main(int argc, char **argv) {
		userid_t userid = 0;
		bool multi_user = false;
		bool full_write = false;
		bool derive_gid = false;
		int i;
		struct rlimit rlim;
		int fs_version;

		int opt;
		while ((opt = getopt(argc, argv, "u:g:U:mw")) != -1) {
		while ((opt = getopt(argc, argv, "u:g:U:mwG")) != -1) {
		switch (opt) {
		case 'u':
		uid = strtoul(optarg, NULL, 10);
		@@ -469,6 +486,9 @@ int main(int argc, char **argv) {
		case 'w':
		full_write = true;
		break;
		case 'G':
		derive_gid = true;
		break;
		case '?':
		default:
		return usage();
		@@ -512,7 +532,7 @@ int main(int argc, char **argv) {
		}

		if (should_use_sdcardfs()) {
		run_sdcardfs(source_path, label, uid, gid, userid, multi_user, full_write);
		run_sdcardfs(source_path, label, uid, gid, userid, multi_user, full_write, derive_gid);
		} else {
		run(source_path, label, uid, gid, userid, multi_user, full_write);
		}