Merge "Plumb through volume UUID when building paths."

cmds/installd/Android.mk

@@ -12,6 +12,7 @@ LOCAL_MODULE := libinstalld
 LOCAL_MODULE_TAGS := eng tests
 LOCAL_SRC_FILES := $(common_src_files)
 LOCAL_CFLAGS := $(common_cflags)
+LOCAL_SHARED_LIBRARIES := libbase
 LOCAL_ADDITIONAL_DEPENDENCIES += $(LOCAL_PATH)/Android.mk
 include $(BUILD_STATIC_LIBRARY)
 
@@ -24,7 +25,12 @@ LOCAL_MODULE := installd
 LOCAL_MODULE_TAGS := optional
 LOCAL_CFLAGS := $(common_cflags)
 LOCAL_SRC_FILES := installd.cpp $(common_src_files)
-LOCAL_SHARED_LIBRARIES := libcutils liblog libselinux
+LOCAL_SHARED_LIBRARIES := \
+    libbase \
+    libcutils \
+    liblog \
+    libselinux \
+
 LOCAL_STATIC_LIBRARIES := libdiskusage
 LOCAL_ADDITIONAL_DEPENDENCIES += $(LOCAL_PATH)/Android.mk
 include $(BUILD_EXECUTABLE)

cmds/installd/commands.cpp

@@ -33,11 +33,8 @@ dir_rec_t android_media_dir;
 dir_rec_t android_mnt_expand_dir;
 dir_rec_array_t android_system_dirs;
 
-int install(const char *pkgname, uid_t uid, gid_t gid, const char *seinfo)
+int install(const char *uuid, const char *pkgname, uid_t uid, gid_t gid, const char *seinfo)
 {
-    char pkgdir[PKG_PATH_MAX];
-    char libsymlink[PKG_PATH_MAX];
-    char applibdir[PKG_PATH_MAX];
     struct stat libStat;
 
     if ((uid < AID_SYSTEM) || (gid < AID_SYSTEM)) {
@@ -45,20 +42,8 @@ int install(const char *pkgname, uid_t uid, gid_t gid, const char *seinfo)
         return -1;
     }
 
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, 0)) {
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, 0));
-        ALOGE("cannot create package path\n");
+    const char* pkgdir = _pkgdir.c_str();
-        return -1;
-    }
-
-    if (create_pkg_path(libsymlink, pkgname, PKG_LIB_POSTFIX, 0)) {
-        ALOGE("cannot create package lib symlink origin path\n");
-        return -1;
-    }
-
-    if (create_pkg_path_in_dir(applibdir, &android_app_lib_dir, pkgname, PKG_DIR_POSTFIX)) {
-        ALOGE("cannot create package lib symlink dest path\n");
-        return -1;
-    }
 
     if (mkdir(pkgdir, 0751) < 0) {
         ALOGE("cannot create dir '%s': %s\n", pkgdir, strerror(errno));
@@ -70,42 +55,14 @@ int install(const char *pkgname, uid_t uid, gid_t gid, const char *seinfo)
         return -1;
     }
 
-    if (lstat(libsymlink, &libStat) < 0) {
-        if (errno != ENOENT) {
-            ALOGE("couldn't stat lib dir: %s\n", strerror(errno));
-            return -1;
-        }
-    } else {
-        if (S_ISDIR(libStat.st_mode)) {
-            if (delete_dir_contents(libsymlink, 1, NULL) < 0) {
-                ALOGE("couldn't delete lib directory during install for: %s", libsymlink);
-                return -1;
-            }
-        } else if (S_ISLNK(libStat.st_mode)) {
-            if (unlink(libsymlink) < 0) {
-                ALOGE("couldn't unlink lib directory during install for: %s", libsymlink);
-                return -1;
-            }
-        }
-    }
-
     if (selinux_android_setfilecon(pkgdir, pkgname, seinfo, uid) < 0) {
         ALOGE("cannot setfilecon dir '%s': %s\n", pkgdir, strerror(errno));
-        unlink(libsymlink);
         unlink(pkgdir);
         return -errno;
     }
 
-    if (symlink(applibdir, libsymlink) < 0) {
-        ALOGE("couldn't symlink directory '%s' -> '%s': %s\n", libsymlink, applibdir,
-                strerror(errno));
-        unlink(pkgdir);
-        return -1;
-    }
-
     if (chown(pkgdir, uid, gid) < 0) {
         ALOGE("cannot chown dir '%s': %s\n", pkgdir, strerror(errno));
-        unlink(libsymlink);
         unlink(pkgdir);
         return -1;
     }
@@ -113,12 +70,10 @@ int install(const char *pkgname, uid_t uid, gid_t gid, const char *seinfo)
     return 0;
 }
 
-int uninstall(const char *pkgname, userid_t userid)
+int uninstall(const char *uuid, const char *pkgname, userid_t userid)
 {
-    char pkgdir[PKG_PATH_MAX];
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, userid));
-
+    const char* pkgdir = _pkgdir.c_str();
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, userid))
-        return -1;
 
     remove_profile_file(pkgname);
 
@@ -143,9 +98,8 @@ int renamepkg(const char *oldpkgname, const char *newpkgname)
     return 0;
 }
 
-int fix_uid(const char *pkgname, uid_t uid, gid_t gid)
+int fix_uid(const char *uuid, const char *pkgname, uid_t uid, gid_t gid)
 {
-    char pkgdir[PKG_PATH_MAX];
     struct stat s;
 
     if ((uid < AID_SYSTEM) || (gid < AID_SYSTEM)) {
@@ -153,10 +107,8 @@ int fix_uid(const char *pkgname, uid_t uid, gid_t gid)
         return -1;
     }
 
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, 0)) {
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, 0));
-        ALOGE("cannot create package path\n");
+    const char* pkgdir = _pkgdir.c_str();
-        return -1;
-    }
 
     if (stat(pkgdir, &s) < 0) return -1;
 
@@ -179,35 +131,20 @@ int fix_uid(const char *pkgname, uid_t uid, gid_t gid)
     return 0;
 }
 
-int delete_user_data(const char *pkgname, userid_t userid)
+int delete_user_data(const char *uuid, const char *pkgname, userid_t userid)
 {
-    char pkgdir[PKG_PATH_MAX];
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, userid));
-
+    const char* pkgdir = _pkgdir.c_str();
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, userid))
-        return -1;
 
     return delete_dir_contents(pkgdir, 0, NULL);
 }
 
-int make_user_data(const char *pkgname, uid_t uid, userid_t userid, const char* seinfo)
+int make_user_data(const char *uuid, const char *pkgname, uid_t uid, userid_t userid, const char* seinfo)
 {
-    char pkgdir[PKG_PATH_MAX];
-    char applibdir[PKG_PATH_MAX];
-    char libsymlink[PKG_PATH_MAX];
     struct stat libStat;
 
-    // Create the data dir for the package
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, userid));
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, userid)) {
+    const char* pkgdir = _pkgdir.c_str();
-        return -1;
-    }
-    if (create_pkg_path(libsymlink, pkgname, PKG_LIB_POSTFIX, userid)) {
-        ALOGE("cannot create package lib symlink origin path\n");
-        return -1;
-    }
-    if (create_pkg_path_in_dir(applibdir, &android_app_lib_dir, pkgname, PKG_DIR_POSTFIX)) {
-        ALOGE("cannot create package lib symlink dest path\n");
-        return -1;
-    }
 
     if (mkdir(pkgdir, 0751) < 0) {
         ALOGE("cannot create dir '%s': %s\n", pkgdir, strerror(errno));
@@ -219,47 +156,14 @@ int make_user_data(const char *pkgname, uid_t uid, userid_t userid, const char*
         return -errno;
     }
 
-    if (lstat(libsymlink, &libStat) < 0) {
-        if (errno != ENOENT) {
-            ALOGE("couldn't stat lib dir for non-primary: %s\n", strerror(errno));
-            unlink(pkgdir);
-            return -1;
-        }
-    } else {
-        if (S_ISDIR(libStat.st_mode)) {
-            if (delete_dir_contents(libsymlink, 1, NULL) < 0) {
-                ALOGE("couldn't delete lib directory during install for non-primary: %s",
-                        libsymlink);
-                unlink(pkgdir);
-                return -1;
-            }
-        } else if (S_ISLNK(libStat.st_mode)) {
-            if (unlink(libsymlink) < 0) {
-                ALOGE("couldn't unlink lib directory during install for non-primary: %s",
-                        libsymlink);
-                unlink(pkgdir);
-                return -1;
-            }
-        }
-    }
-
     if (selinux_android_setfilecon(pkgdir, pkgname, seinfo, uid) < 0) {
         ALOGE("cannot setfilecon dir '%s': %s\n", pkgdir, strerror(errno));
-        unlink(libsymlink);
         unlink(pkgdir);
         return -errno;
     }
 
-    if (symlink(applibdir, libsymlink) < 0) {
-        ALOGE("couldn't symlink directory for non-primary '%s' -> '%s': %s\n", libsymlink,
-                applibdir, strerror(errno));
-        unlink(pkgdir);
-        return -1;
-    }
-
     if (chown(pkgdir, uid, uid) < 0) {
         ALOGE("cannot chown dir '%s': %s\n", pkgdir, strerror(errno));
-        unlink(libsymlink);
         unlink(pkgdir);
         return -errno;
     }
@@ -301,24 +205,23 @@ int delete_user(userid_t userid)
     return status;
 }
 
-int delete_cache(const char *pkgname, userid_t userid)
+int delete_cache(const char *uuid, const char *pkgname, userid_t userid)
 {
-    char cachedir[PKG_PATH_MAX];
+    std::string _cachedir(
-
+            create_package_data_path(uuid, pkgname, userid) + CACHE_DIR_POSTFIX);
-    if (create_pkg_path(cachedir, pkgname, CACHE_DIR_POSTFIX, userid))
+    const char* cachedir = _cachedir.c_str();
-        return -1;
 
     /* delete contents, not the directory, no exceptions */
     return delete_dir_contents(cachedir, 0, NULL);
 }
 
-int delete_code_cache(const char *pkgname, userid_t userid)
+int delete_code_cache(const char *uuid, const char *pkgname, userid_t userid)
 {
-    char codecachedir[PKG_PATH_MAX];
+    std::string _codecachedir(
-    struct stat s;
+            create_package_data_path(uuid, pkgname, userid) + CACHE_DIR_POSTFIX);
+    const char* codecachedir = _codecachedir.c_str();
 
-    if (create_pkg_path(codecachedir, pkgname, CODE_CACHE_DIR_POSTFIX, userid))
+    struct stat s;
-        return -1;
 
     /* it's okay if code cache is missing */
     if (lstat(codecachedir, &s) == -1 && errno == ENOENT) {
@@ -336,6 +239,7 @@ int delete_code_cache(const char *pkgname, userid_t userid)
  * also require that apps constantly modify file metadata even
  * when just reading from the cache, which is pretty awful.
  */
+// TODO: extend to know about other volumes
 int free_cache(int64_t free_size)
 {
     cache_t* cache;
@@ -467,7 +371,7 @@ int rm_dex(const char *path, const char *instruction_set)
     }
 }
 
-int get_size(const char *pkgname, userid_t userid, const char *apkpath,
+int get_size(const char *uuid, const char *pkgname, userid_t userid, const char *apkpath,
              const char *libdirpath, const char *fwdlock_apkpath, const char *asecpath,
              const char *instruction_set, int64_t *_codesize, int64_t *_datasize,
              int64_t *_cachesize, int64_t* _asecsize)
@@ -524,11 +428,10 @@ int get_size(const char *pkgname, userid_t userid, const char *apkpath,
         }
     }
 
-    if (create_pkg_path(path, pkgname, PKG_DIR_POSTFIX, userid)) {
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, userid));
-        goto done;
+    const char* pkgdir = _pkgdir.c_str();
-    }
 
-    d = opendir(path);
+    d = opendir(pkgdir);
     if (d == NULL) {
         goto done;
     }
@@ -1457,21 +1360,16 @@ done:
     return 0;
 }
 
-int linklib(const char* pkgname, const char* asecLibDir, int userId)
+int linklib(const char* uuid, const char* pkgname, const char* asecLibDir, int userId)
 {
-    char pkgdir[PKG_PATH_MAX];
-    char libsymlink[PKG_PATH_MAX];
     struct stat s, libStat;
     int rc = 0;
 
-    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, userId)) {
+    std::string _pkgdir(create_package_data_path(uuid, pkgname, userId));
-        ALOGE("cannot create package path\n");
+    std::string _libsymlink(_pkgdir + PKG_LIB_POSTFIX);
-        return -1;
+
-    }
+    const char* pkgdir = _pkgdir.c_str();
-    if (create_pkg_path(libsymlink, pkgname, PKG_LIB_POSTFIX, userId)) {
+    const char* libsymlink = _libsymlink.c_str();
-        ALOGE("cannot create package lib symlink origin path\n");
-        return -1;
-    }
 
     if (stat(pkgdir, &s) < 0) return -1;
 
@@ -1640,7 +1538,8 @@ fail:
     return -1;
 }
 
-int restorecon_data(const char* pkgName, const char* seinfo, uid_t uid)
+// TODO: extend to know about other volumes
+int restorecon_data(const char *uuid, const char* pkgName, const char* seinfo, uid_t uid)
 {
     struct dirent *entry;
     DIR *d;

cmds/installd/installd.cpp

@@ -33,7 +33,7 @@ static int do_ping(char **arg __unused, char reply[REPLY_MAX] __unused)
 
 static int do_install(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return install(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]); /* pkgname, uid, gid, seinfo */
+    return install(nullptr, arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]); /* pkgname, uid, gid, seinfo */
 }
 
 static int do_dexopt(char **arg, char reply[REPLY_MAX] __unused)
@@ -61,7 +61,7 @@ static int do_rm_dex(char **arg, char reply[REPLY_MAX] __unused)
 
 static int do_remove(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return uninstall(arg[0], atoi(arg[1])); /* pkgname, userid */
+    return uninstall(nullptr, arg[0], atoi(arg[1])); /* pkgname, userid */
 }
 
 static int do_rename(char **arg, char reply[REPLY_MAX] __unused)
@@ -71,7 +71,7 @@ static int do_rename(char **arg, char reply[REPLY_MAX] __unused)
 
 static int do_fixuid(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return fix_uid(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
+    return fix_uid(nullptr, arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
 }
 
 static int do_free_cache(char **arg, char reply[REPLY_MAX] __unused) /* TODO int:free_size */
@@ -81,12 +81,12 @@ static int do_free_cache(char **arg, char reply[REPLY_MAX] __unused) /* TODO int
 
 static int do_rm_cache(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return delete_cache(arg[0], atoi(arg[1])); /* pkgname, userid */
+    return delete_cache(nullptr, arg[0], atoi(arg[1])); /* pkgname, userid */
 }
 
 static int do_rm_code_cache(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return delete_code_cache(arg[0], atoi(arg[1])); /* pkgname, userid */
+    return delete_code_cache(nullptr, arg[0], atoi(arg[1])); /* pkgname, userid */
 }
 
 static int do_get_size(char **arg, char reply[REPLY_MAX])
@@ -98,7 +98,7 @@ static int do_get_size(char **arg, char reply[REPLY_MAX])
     int res = 0;
 
         /* pkgdir, userid, apkpath */
-    res = get_size(arg[0], atoi(arg[1]), arg[2], arg[3], arg[4], arg[5],
+    res = get_size(nullptr, arg[0], atoi(arg[1]), arg[2], arg[3], arg[4], arg[5],
             arg[6], &codesize, &datasize, &cachesize, &asecsize);
 
     /*
@@ -112,12 +112,12 @@ static int do_get_size(char **arg, char reply[REPLY_MAX])
 
 static int do_rm_user_data(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return delete_user_data(arg[0], atoi(arg[1])); /* pkgname, userid */
+    return delete_user_data(nullptr, arg[0], atoi(arg[1])); /* pkgname, userid */
 }
 
 static int do_mk_user_data(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return make_user_data(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]);
+    return make_user_data(nullptr, arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]);
                              /* pkgname, uid, userid, seinfo */
 }
 
@@ -138,7 +138,7 @@ static int do_movefiles(char **arg __unused, char reply[REPLY_MAX] __unused)
 
 static int do_linklib(char **arg, char reply[REPLY_MAX] __unused)
 {
-    return linklib(arg[0], arg[1], atoi(arg[2]));
+    return linklib(nullptr, arg[0], arg[1], atoi(arg[2]));
 }
 
 static int do_idmap(char **arg, char reply[REPLY_MAX] __unused)
@@ -148,7 +148,7 @@ static int do_idmap(char **arg, char reply[REPLY_MAX] __unused)
 
 static int do_restorecon_data(char **arg, char reply[REPLY_MAX] __attribute__((unused)))
 {
-    return restorecon_data(arg[0], arg[1], atoi(arg[2]));
+    return restorecon_data(nullptr, arg[0], arg[1], atoi(arg[2]));
                              /* pkgName, seinfo, uid*/
 }
 

cmds/installd/installd.h

@@ -31,6 +31,7 @@
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <string>
 
 #include <cutils/fs.h>
 #include <cutils/sockets.h>
@@ -138,10 +139,8 @@ typedef struct {
 
 /* util.c */
 
-int create_pkg_path_in_dir(char path[PKG_PATH_MAX],
+std::string create_package_data_path(const char* volume_uuid,
-                                const dir_rec_t* dir,
+        const char* package_name, userid_t user);
-                                const char* pkgname,
-                                const char* postfix);
 
 int create_pkg_path(char path[PKG_PATH_MAX],
                     const char *pkgname,
@@ -208,20 +207,20 @@ void remove_profile_file(const char *pkgname);
 
 /* commands.c */
 
-int install(const char *pkgname, uid_t uid, gid_t gid, const char *seinfo);
+int install(const char *uuid, const char *pkgname, uid_t uid, gid_t gid, const char *seinfo);
-int uninstall(const char *pkgname, userid_t userid);
+int uninstall(const char *uuid, const char *pkgname, userid_t userid);
 int renamepkg(const char *oldpkgname, const char *newpkgname);
-int fix_uid(const char *pkgname, uid_t uid, gid_t gid);
+int fix_uid(const char *uuid, const char *pkgname, uid_t uid, gid_t gid);
-int delete_user_data(const char *pkgname, userid_t userid);
+int delete_user_data(const char *uuid, const char *pkgname, userid_t userid);
-int make_user_data(const char *pkgname, uid_t uid, userid_t userid, const char* seinfo);
+int make_user_data(const char *uuid, const char *pkgname, uid_t uid, userid_t userid, const char* seinfo);
 int make_user_config(userid_t userid);
 int delete_user(userid_t userid);
-int delete_cache(const char *pkgname, userid_t userid);
+int delete_cache(const char *uuid, const char *pkgname, userid_t userid);
-int delete_code_cache(const char *pkgname, userid_t userid);
+int delete_code_cache(const char *uuid, const char *pkgname, userid_t userid);
 int move_dex(const char *src, const char *dst, const char *instruction_set);
 int rm_dex(const char *path, const char *instruction_set);
 int protect(char *pkgname, gid_t gid);
-int get_size(const char *pkgname, userid_t userid, const char *apkpath, const char *libdirpath,
+int get_size(const char *uuid, const char *pkgname, userid_t userid, const char *apkpath, const char *libdirpath,
              const char *fwdlock_apkpath, const char *asecpath, const char *instruction_set,
              int64_t *codesize, int64_t *datasize, int64_t *cachesize, int64_t *asecsize);
 int free_cache(int64_t free_size);
@@ -230,9 +229,9 @@ int dexopt(const char *apk_path, uid_t uid, bool is_public, const char *pkgName,
            bool debuggable, const char* oat_dir);
 int mark_boot_complete(const char *instruction_set);
 int movefiles();
-int linklib(const char* target, const char* source, int userId);
+int linklib(const char *uuid, const char* target, const char* source, int userId);
 int idmap(const char *target_path, const char *overlay_path, uid_t uid);
-int restorecon_data(const char* pkgName, const char* seinfo, uid_t uid);
+int restorecon_data(const char *uuid, const char* pkgName, const char* seinfo, uid_t uid);
 int create_oat_dir(const char* oat_dir, const char *instruction_set);
 int rm_package_dir(const char* apk_path);
 int calculate_oat_file_path(char path[PKG_PATH_MAX], const char *oat_dir, const char *apk_path,

cmds/installd/tests/Android.mk

@@ -8,6 +8,7 @@ test_src_files := \
     installd_utils_test.cpp
 
 shared_libraries := \
+    libbase \
     libutils \
     libcutils \
 

cmds/installd/tests/installd_utils_test.cpp

@@ -321,6 +321,7 @@ TEST_F(UtilsTest, CreatePkgPath_LongPkgNameSuccess) {
 
     const char *prefix = TEST_DATA_DIR PRIMARY_USER_PREFIX;
     size_t offset = strlen(prefix);
+
     EXPECT_STREQ(pkgname, path + offset)
              << "Package path should be a really long string of a's";
 }
@@ -371,20 +372,6 @@ TEST_F(UtilsTest, CreatePkgPath_SecondaryUser) {
             << "Package path should be in /data/user/";
 }
 
-TEST_F(UtilsTest, CreatePkgPathInDir_ProtectedDir) {
-    char path[PKG_PATH_MAX];
-
-    dir_rec_t dir;
-    dir.path = (char*) "/data/app-private/";
-    dir.len = strlen(dir.path);
-
-    EXPECT_EQ(0, create_pkg_path_in_dir(path, &dir, "com.example.package", ".apk"))
-            << "Should successfully create package path.";
-
-    EXPECT_STREQ("/data/app-private/com.example.package.apk", path)
-            << "Package path should be in /data/app-private/";
-}
-
 TEST_F(UtilsTest, CreatePersonaPath_Primary) {
     char path[PKG_PATH_MAX];
 
@@ -482,4 +469,14 @@ TEST_F(UtilsTest, AppendAndIncrement_TooBig) {
             << "String should fail because it's too large to fit";
 }
 
+TEST_F(UtilsTest, CreatePackageDataPath) {
+    EXPECT_EQ("/data/data/com.example", create_package_data_path(nullptr, "com.example", 0));
+    EXPECT_EQ("/data/user/10/com.example", create_package_data_path(nullptr, "com.example", 10));
+
+    EXPECT_EQ("/mnt/expand/57f8f4bc-abf4-655f-bf67-946fc0f9f25b/user/0/com.example",
+            create_package_data_path("57f8f4bc-abf4-655f-bf67-946fc0f9f25b", "com.example", 0));
+    EXPECT_EQ("/mnt/expand/57f8f4bc-abf4-655f-bf67-946fc0f9f25b/user/10/com.example",
+            create_package_data_path("57f8f4bc-abf4-655f-bf67-946fc0f9f25b", "com.example", 10));
+}
+
 }

cmds/installd/utils.cpp

@@ -16,88 +16,71 @@
 
 #include "installd.h"
 
+#include <base/stringprintf.h>
+#include <base/logging.h>
+
 #define CACHE_NOISY(x) //x
 
-int create_pkg_path_in_dir(char path[PKG_PATH_MAX],
+using android::base::StringPrintf;
-                                const dir_rec_t* dir,
-                                const char* pkgname,
-                                const char* postfix)
-{
-     const size_t postfix_len = strlen(postfix);
 
-     const size_t pkgname_len = strlen(pkgname);
+/**
-     if (pkgname_len > PKG_NAME_MAX) {
+ * Check that given string is valid filename, and that it attempts no
-         return -1;
+ * parent or child directory traversal.
+ */
+static bool is_valid_filename(const std::string& name) {
+    if (name.empty() || (name == ".") || (name == "..")
+            || (name.find('/') != std::string::npos)) {
+        return false;
+    } else {
+        return true;
     }
-
-     if (is_valid_package_name(pkgname) < 0) {
-         return -1;
-     }
-
-     if ((pkgname_len + dir->len + postfix_len) >= PKG_PATH_MAX) {
-         return -1;
-     }
-
-     char *dst = path;
-     size_t dst_size = PKG_PATH_MAX;
-
-     if (append_and_increment(&dst, dir->path, &dst_size) < 0
-             || append_and_increment(&dst, pkgname, &dst_size) < 0
-             || append_and_increment(&dst, postfix, &dst_size) < 0) {
-         ALOGE("Error building APK path");
-         return -1;
-     }
-
-     return 0;
 }
 
 /**
- * Create the package path name for a given package name with a postfix for
+ * Create the path name where package data should be stored for the given
- * a certain userid. Returns 0 on success, and -1 on failure.
+ * volume UUID, package name, and user ID. An empty UUID is assumed to be
+ * internal storage.
  */
-int create_pkg_path(char path[PKG_PATH_MAX],
+std::string create_package_data_path(const char* volume_uuid,
-                    const char *pkgname,
+        const char* package_name, userid_t user) {
-                    const char *postfix,
+    CHECK(is_valid_filename(package_name));
-                    userid_t userid)
+    CHECK(is_valid_package_name(package_name) == 0);
-{
+
-    size_t userid_len;
+    if (volume_uuid == nullptr) {
-    const char* userid_prefix;
+        if (user == 0) {
-    if (userid == 0) {
+            // /data/data/com.example
-        userid_prefix = PRIMARY_USER_PREFIX;
+            return StringPrintf("%sdata/%s", android_data_dir.path, package_name);
-        userid_len = 0;
         } else {
-        userid_prefix = SECONDARY_USER_PREFIX;
+            // /data/user/0/com.example
-        userid_len = snprintf(NULL, 0, "%d", userid);
+            return StringPrintf("%suser/%u/%s", android_data_dir.path, user, package_name);
+        }
+    } else {
+        CHECK(is_valid_filename(volume_uuid));
+
+        // /mnt/expand/uuid/user/0/com.example
+        return StringPrintf("%s%s/user/%u/%s", android_mnt_expand_dir.path,
+                volume_uuid, user, package_name);
+    }
 }
 
-    const size_t prefix_len = android_data_dir.len + strlen(userid_prefix)
+int create_pkg_path(char path[PKG_PATH_MAX], const char *pkgname,
-            + userid_len + 1 /*slash*/;
+        const char *postfix, userid_t userid) {
-    char prefix[prefix_len + 1];
+    if (is_valid_package_name(pkgname) != 0) {
-
+        path[0] = '\0';
-    char *dst = prefix;
-    size_t dst_size = sizeof(prefix);
-
-    if (append_and_increment(&dst, android_data_dir.path, &dst_size) < 0
-            || append_and_increment(&dst, userid_prefix, &dst_size) < 0) {
-        ALOGE("Error building prefix for APK path");
         return -1;
     }
 
-    if (userid != 0) {
+    std::string _tmp(create_package_data_path(nullptr, pkgname, userid) + postfix);
-        int ret = snprintf(dst, dst_size, "%d/", userid);
+    const char* tmp = _tmp.c_str();
-        if (ret < 0 || (size_t) ret != userid_len + 1) {
+    if (strlen(tmp) >= PKG_PATH_MAX) {
-            ALOGW("Error appending UID to APK path");
+        path[0] = '\0';
         return -1;
+    } else {
+        strcpy(path, tmp);
+        return 0;
     }
 }
 
-    dir_rec_t dir;
-    dir.path = prefix;
-    dir.len = prefix_len;
-
-    return create_pkg_path_in_dir(path, &dir, pkgname, postfix);
-}
-
 /**
  * Create the path name for user data for a certain userid.
  * Returns 0 on success, and -1 on failure.
@@ -182,6 +165,10 @@ int is_valid_package_name(const char* pkgname) {
     const char *x = pkgname;
     int alpha = -1;
 
+    if (strlen(pkgname) > PKG_NAME_MAX) {
+        return -1;
+    }
+
     while (*x) {
         if (isalnum(*x) || (*x == '_')) {
                 /* alphanumeric or underscore are fine */