/*
** Copyright 2008, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "utils.h"
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/xattr.h>
#include <sys/statvfs.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <cutils/properties.h>
#include <log/log.h>
#include <private/android_filesystem_config.h>
#include "globals.h" // extern variables.
#ifndef LOG_TAG
#define LOG_TAG "installd"
#endif
#define DEBUG_XATTRS 0
using android::base::StringPrintf;
namespace android {
namespace installd {
/**
* Check that given string is valid filename, and that it attempts no
* parent or child directory traversal.
*/
bool is_valid_filename(const std::string& name) {
if (name.empty() || (name == ".") || (name == "..")
|| (name.find('/') != std::string::npos)) {
return false;
} else {
return true;
}
}
static void check_package_name(const char* package_name) {
CHECK(is_valid_filename(package_name));
CHECK(is_valid_package_name(package_name));
}
/**
* Create the path name where package app contents should be stored for
* the given volume UUID and package name. An empty UUID is assumed to
* be internal storage.
*/
std::string create_data_app_package_path(const char* volume_uuid,
const char* package_name) {
check_package_name(package_name);
return StringPrintf("%s/%s",
create_data_app_path(volume_uuid).c_str(), package_name);
}
/**
* Create the path name where package data should be stored for the given
* volume UUID, package name, and user ID. An empty UUID is assumed to be
* internal storage.
*/
std::string create_data_user_ce_package_path(const char* volume_uuid,
userid_t user, const char* package_name) {
check_package_name(package_name);
return StringPrintf("%s/%s",
create_data_user_ce_path(volume_uuid, user).c_str(), package_name);
}
std::string create_data_user_ce_package_path(const char* volume_uuid, userid_t user,
const char* package_name, ino_t ce_data_inode) {
// For testing purposes, rely on the inode when defined; this could be
// optimized to use access() in the future.
auto fallback = create_data_user_ce_package_path(volume_uuid, user, package_name);
if (ce_data_inode != 0) {
auto user_path = create_data_user_ce_path(volume_uuid, user);
DIR* dir = opendir(user_path.c_str());
if (dir == nullptr) {
PLOG(ERROR) << "Failed to opendir " << user_path;
return fallback;
}
struct dirent* ent;
while ((ent = readdir(dir))) {
if (ent->d_ino == ce_data_inode) {
auto resolved = StringPrintf("%s/%s", user_path.c_str(), ent->d_name);
#if DEBUG_XATTRS
if (resolved != fallback) {
LOG(DEBUG) << "Resolved path " << resolved << " for inode " << ce_data_inode
<< " instead of " << fallback;
}
#endif
closedir(dir);
return resolved;
}
}
LOG(WARNING) << "Failed to resolve inode " << ce_data_inode << "; using " << fallback;
closedir(dir);
return fallback;
} else {
return fallback;
}
}
std::string create_data_user_de_package_path(const char* volume_uuid,
userid_t user, const char* package_name) {
check_package_name(package_name);
return StringPrintf("%s/%s",
create_data_user_de_path(volume_uuid, user).c_str(), package_name);
}
int create_pkg_path(char path[PKG_PATH_MAX], const char *pkgname,
const char *postfix, userid_t userid) {
if (!is_valid_package_name(pkgname)) {
path[0] = '\0';
return -1;
}
std::string _tmp(create_data_user_ce_package_path(nullptr, userid, pkgname) + postfix);
const char* tmp = _tmp.c_str();
if (strlen(tmp) >= PKG_PATH_MAX) {
path[0] = '\0';
return -1;
} else {
strcpy(path, tmp);
return 0;
}
}
std::string create_data_path(const char* volume_uuid) {
if (volume_uuid == nullptr) {
return "/data";
} else if (!strcmp(volume_uuid, "TEST")) {
CHECK(property_get_bool("ro.debuggable", false));
return "/data/local/tmp";
} else {
CHECK(is_valid_filename(volume_uuid));
return StringPrintf("/mnt/expand/%s", volume_uuid);
}
}
/**
* Create the path name for app data.
*/
std::string create_data_app_path(const char* volume_uuid) {
return StringPrintf("%s/app", create_data_path(volume_uuid).c_str());
}
/**
* Create the path name for user data for a certain userid.
*/
std::string create_data_user_ce_path(const char* volume_uuid, userid_t userid) {
std::string data(create_data_path(volume_uuid));
if (volume_uuid == nullptr) {
if (userid == 0) {
return StringPrintf("%s/data", data.c_str());
} else {
return StringPrintf("%s/user/%u", data.c_str(), userid);
}
} else {
return StringPrintf("%s/user/%u", data.c_str(), userid);
}
}
/**
* Create the path name for device encrypted user data for a certain userid.
*/
std::string create_data_user_de_path(const char* volume_uuid, userid_t userid) {
std::string data(create_data_path(volume_uuid));
return StringPrintf("%s/user_de/%u", data.c_str(), userid);
}
/**
* Create the path name for media for a certain userid.
*/
std::string create_data_media_path(const char* volume_uuid, userid_t userid) {
return StringPrintf("%s/media/%u", create_data_path(volume_uuid).c_str(), userid);
}
std::string create_data_media_obb_path(const char* volume_uuid, const char* package_name) {
return StringPrintf("%s/media/obb/%s", create_data_path(volume_uuid).c_str(), package_name);
}
std::string create_data_media_package_path(const char* volume_uuid, userid_t userid,
const char* data_type, const char* package_name) {
return StringPrintf("%s/Android/%s/%s", create_data_media_path(volume_uuid, userid).c_str(),
data_type, package_name);
}
std::string create_data_misc_legacy_path(userid_t userid) {
return StringPrintf("%s/misc/user/%u", create_data_path(nullptr).c_str(), userid);
}
std::string create_primary_cur_profile_dir_path(userid_t userid) {
return StringPrintf("%s/cur/%u", android_profiles_dir.path, userid);
}
std::string create_primary_current_profile_package_dir_path(userid_t user,
const std::string& package_name) {
check_package_name(package_name.c_str());
return StringPrintf("%s/%s",
create_primary_cur_profile_dir_path(user).c_str(), package_name.c_str());
}
std::string create_primary_ref_profile_dir_path() {
return StringPrintf("%s/ref", android_profiles_dir.path);
}
std::string create_primary_reference_profile_package_dir_path(const std::string& package_name) {
check_package_name(package_name.c_str());
return StringPrintf("%s/ref/%s", android_profiles_dir.path, package_name.c_str());
}
std::string create_data_dalvik_cache_path() {
return "/data/dalvik-cache";
}
// Keep profile paths in sync with ActivityThread and LoadedApk.
const std::string PROFILE_EXT = ".prof";
const std::string PRIMARY_PROFILE_NAME = "primary" + PROFILE_EXT;
std::string create_current_profile_path(userid_t user, const std::string& location,
bool is_secondary_dex) {
if (is_secondary_dex) {
// Secondary dex profiles are stored next to the dex files using .prof extension.
return StringPrintf("%s%s", location.c_str(), PROFILE_EXT.c_str());
} else {
// Profiles for primary apks are under /data/misc/profiles/cur.
std::string profile_dir = create_primary_current_profile_package_dir_path(user, location);
return StringPrintf("%s/%s", profile_dir.c_str(), PRIMARY_PROFILE_NAME.c_str());
}
}
std::string create_reference_profile_path(const std::string& location, bool is_secondary_dex) {
if (is_secondary_dex) {
// Secondary dex reference profiles are stored next to the dex files under the oat folder.
size_t dirIndex = location.rfind('/');
CHECK(dirIndex != std::string::npos)
<< "Unexpected dir structure for secondary dex " << location;
std::string dex_dir = location.substr(0, dirIndex);
std::string dex_name = location.substr(dirIndex +1);
return StringPrintf("%s/oat/%s%s",
dex_dir.c_str(), dex_name.c_str(), PROFILE_EXT.c_str());
} else {
// Reference profiles for primary apks are stored in /data/misc/profile/ref.
std::string profile_dir = create_primary_reference_profile_package_dir_path(location);
return StringPrintf("%s/%s", profile_dir.c_str(), PRIMARY_PROFILE_NAME.c_str());
}
}
std::vector<userid_t> get_known_users(const char* volume_uuid) {
std::vector<userid_t> users;
// We always have an owner
users.push_back(0);
std::string path(create_data_path(volume_uuid) + "/" + SECONDARY_USER_PREFIX);
DIR* dir = opendir(path.c_str());
if (dir == NULL) {
// Unable to discover other users, but at least return owner
PLOG(ERROR) << "Failed to opendir " << path;
return users;
}
struct dirent* ent;
while ((ent = readdir(dir))) {
if (ent->d_type != DT_DIR) {
continue;
}
char* end;
userid_t user = strtol(ent->d_name, &end, 10);
if (*end == '\0' && user != 0) {
LOG(DEBUG) << "Found valid user " << user;
users.push_back(user);
}
}
closedir(dir);
return users;
}
int calculate_tree_size(const std::string& path, int64_t* size,
int32_t include_gid, int32_t exclude_gid, bool exclude_apps) {
FTS *fts;
FTSENT *p;
int64_t matchedSize = 0;
char *argv[] = { (char*) path.c_str(), nullptr };
if (!(fts = fts_open(argv, FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV, NULL))) {
if (errno != ENOENT) {
PLOG(ERROR) << "Failed to fts_open " << path;
}
return -1;
}
while ((p = fts_read(fts)) != NULL) {
switch (p->fts_info) {
case FTS_D:
case FTS_DEFAULT:
case FTS_F:
case FTS_SL:
case FTS_SLNONE:
int32_t uid = p->fts_statp->st_uid;
int32_t gid = p->fts_statp->st_gid;
int32_t user_uid = multiuser_get_app_id(uid);
int32_t user_gid = multiuser_get_app_id(gid);
if (exclude_apps && ((user_uid >= AID_APP_START && user_uid <= AID_APP_END)
|| (user_gid >= AID_CACHE_GID_START && user_gid <= AID_CACHE_GID_END)
|| (user_gid >= AID_SHARED_GID_START && user_gid <= AID_SHARED_GID_END))) {
// Don't traverse inside or measure
fts_set(fts, p, FTS_SKIP);
break;
}
if (include_gid != -1 && gid != include_gid) {
break;
}
if (exclude_gid != -1 && gid == exclude_gid) {
break;
}
matchedSize += (p->fts_statp->st_blocks * 512);
break;
}
}
fts_close(fts);
#if MEASURE_DEBUG
if ((include_gid == -1) && (exclude_gid == -1)) {
LOG(DEBUG) << "Measured " << path << " size " << matchedSize;
} else {
LOG(DEBUG) << "Measured " << path << " size " << matchedSize << "; include " << include_gid
<< " exclude " << exclude_gid;
}
#endif
*size += matchedSize;
return 0;
}
int create_move_path(char path[PKG_PATH_MAX],
const char* pkgname,
const char* leaf,
userid_t userid ATTRIBUTE_UNUSED)
{
if ((android_data_dir.len + strlen(PRIMARY_USER_PREFIX) + strlen(pkgname) + strlen(leaf) + 1)
>= PKG_PATH_MAX) {
return -1;
}
sprintf(path, "%s%s%s/%s", android_data_dir.path, PRIMARY_USER_PREFIX, pkgname, leaf);
return 0;
}
/**
* Checks whether the package name is valid. Returns -1 on error and
* 0 on success.
*/
bool is_valid_package_name(const std::string& packageName) {
// This logic is borrowed from PackageParser.java
bool hasSep = false;
bool front = true;
auto it = packageName.begin();
for (; it != packageName.end() && *it != '-'; it++) {
char c = *it;
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
front = false;
continue;
}
if (!front) {
if ((c >= '0' && c <= '9') || c == '_') {
continue;
}
}
if (c == '.') {
hasSep = true;
front = true;
continue;
}
LOG(WARNING) << "Bad package character " << c << " in " << packageName;
return false;
}
if (front) {
LOG(WARNING) << "Missing separator in " << packageName;
return false;
}
for (; it != packageName.end(); it++) {
char c = *it;
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) continue;
if ((c >= '0' && c <= '9') || c == '_' || c == '-' || c == '=') continue;
LOG(WARNING) << "Bad suffix character " << c << " in " << packageName;
return false;
}
return true;
}
static int _delete_dir_contents(DIR *d,
int (*exclusion_predicate)(const char *name, const int is_dir))
{
int result = 0;
struct dirent *de;
int dfd;
dfd = dirfd(d);
if (dfd < 0) return -1;
while ((de = readdir(d))) {
const char *name = de->d_name;
/* check using the exclusion predicate, if provided */
if (exclusion_predicate && exclusion_predicate(name, (de->d_type == DT_DIR))) {
continue;
}
if (de->d_type == DT_DIR) {
int subfd;
DIR *subdir;
/* always skip "." and ".." */
if (name[0] == '.') {
if (name[1] == 0) continue;
if ((name[1] == '.') && (name[2] == 0)) continue;
}
subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
if (subfd < 0) {
ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
result = -1;
continue;
}
subdir = fdopendir(subfd);
if (subdir == NULL) {
ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
close(subfd);
result = -1;
continue;
}
if (_delete_dir_contents(subdir, exclusion_predicate)) {
result = -1;
}
closedir(subdir);
if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
result = -1;
}
} else {
if (unlinkat(dfd, name, 0) < 0) {
ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
result = -1;
}
}
}
return result;
}
int delete_dir_contents(const std::string& pathname, bool ignore_if_missing) {
return delete_dir_contents(pathname.c_str(), 0, NULL, ignore_if_missing);
}
int delete_dir_contents_and_dir(const std::string& pathname, bool ignore_if_missing) {
return delete_dir_contents(pathname.c_str(), 1, NULL, ignore_if_missing);
}
int delete_dir_contents(const char *pathname,
int also_delete_dir,
int (*exclusion_predicate)(const char*, const int),
bool ignore_if_missing)
{
int res = 0;
DIR *d;
d = opendir(pathname);
if (d == NULL) {
if (ignore_if_missing && (errno == ENOENT)) {
return 0;
}
ALOGE("Couldn't opendir %s: %s\n", pathname, strerror(errno));
return -errno;
}
res = _delete_dir_contents(d, exclusion_predicate);
closedir(d);
if (also_delete_dir) {
if (rmdir(pathname)) {
ALOGE("Couldn't rmdir %s: %s\n", pathname, strerror(errno));
res = -1;
}
}
return res;
}
int delete_dir_contents_fd(int dfd, const char *name)
{
int fd, res;
DIR *d;
fd = openat(dfd, name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
if (fd < 0) {
ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
return -1;
}
d = fdopendir(fd);
if (d == NULL) {
ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
close(fd);
return -1;
}
res = _delete_dir_contents(d, 0);
closedir(d);
return res;
}
static int _copy_owner_permissions(int srcfd, int dstfd)
{
struct stat st;
if (fstat(srcfd, &st) != 0) {
return -1;
}
if (fchmod(dstfd, st.st_mode) != 0) {
return -1;
}
return 0;
}
static int _copy_dir_files(int sdfd, int ddfd, uid_t owner, gid_t group)
{
int result = 0;
if (_copy_owner_permissions(sdfd, ddfd) != 0) {
ALOGE("_copy_dir_files failed to copy dir permissions\n");
}
if (fchown(ddfd, owner, group) != 0) {
ALOGE("_copy_dir_files failed to change dir owner\n");
}
DIR *ds = fdopendir(sdfd);
if (ds == NULL) {
ALOGE("Couldn't fdopendir: %s\n", strerror(errno));
return -1;
}
struct dirent *de;
while ((de = readdir(ds))) {
if (de->d_type != DT_REG) {
continue;
}
const char *name = de->d_name;
int fsfd = openat(sdfd, name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
int fdfd = openat(ddfd, name, O_WRONLY | O_NOFOLLOW | O_CLOEXEC | O_CREAT, 0600);
if (fsfd == -1 || fdfd == -1) {
ALOGW("Couldn't copy %s: %s\n", name, strerror(errno));
} else {
if (_copy_owner_permissions(fsfd, fdfd) != 0) {
ALOGE("Failed to change file permissions\n");
}
if (fchown(fdfd, owner, group) != 0) {
ALOGE("Failed to change file owner\n");
}
char buf[8192];
ssize_t size;
while ((size = read(fsfd, buf, sizeof(buf))) > 0) {
write(fdfd, buf, size);
}
if (size < 0) {
ALOGW("Couldn't copy %s: %s\n", name, strerror(errno));
result = -1;
}
}
close(fdfd);
close(fsfd);
}
return result;
}
int copy_dir_files(const char *srcname,
const char *dstname,
uid_t owner,
uid_t group)
{
int res = 0;
DIR *ds = NULL;
DIR *dd = NULL;
ds = opendir(srcname);
if (ds == NULL) {
ALOGE("Couldn't opendir %s: %s\n", srcname, strerror(errno));
return -errno;
}
mkdir(dstname, 0600);
dd = opendir(dstname);
if (dd == NULL) {
ALOGE("Couldn't opendir %s: %s\n", dstname, strerror(errno));
closedir(ds);
return -errno;
}
int sdfd = dirfd(ds);
int ddfd = dirfd(dd);
if (sdfd != -1 && ddfd != -1) {
res = _copy_dir_files(sdfd, ddfd, owner, group);
} else {
res = -errno;
}
closedir(dd);
closedir(ds);
return res;
}
int64_t data_disk_free(const std::string& data_path) {
struct statvfs sfs;
if (statvfs(data_path.c_str(), &sfs) == 0) {
return sfs.f_bavail * sfs.f_frsize;
} else {
PLOG(ERROR) << "Couldn't statvfs " << data_path;
return -1;
}
}
int get_path_inode(const std::string& path, ino_t *inode) {
struct stat buf;
memset(&buf, 0, sizeof(buf));
if (stat(path.c_str(), &buf) != 0) {
PLOG(WARNING) << "Failed to stat " << path;
return -1;
} else {
*inode = buf.st_ino;
return 0;
}
}
/**
* Write the inode of a specific child file into the given xattr on the
* parent directory. This allows you to find the child later, even if its
* name is encrypted.
*/
int write_path_inode(const std::string& parent, const char* name, const char* inode_xattr) {
ino_t inode = 0;
uint64_t inode_raw = 0;
auto path = StringPrintf("%s/%s", parent.c_str(), name);
if (get_path_inode(path, &inode) != 0) {
// Path probably doesn't exist yet; ignore
return 0;
}
// Check to see if already set correctly
if (getxattr(parent.c_str(), inode_xattr, &inode_raw, sizeof(inode_raw)) == sizeof(inode_raw)) {
if (inode_raw == inode) {
// Already set correctly; skip writing
return 0;
} else {
PLOG(WARNING) << "Mismatched inode value; found " << inode
<< " on disk but marked value was " << inode_raw << "; overwriting";
}
}
inode_raw = inode;
if (setxattr(parent.c_str(), inode_xattr, &inode_raw, sizeof(inode_raw), 0) != 0 && errno != EOPNOTSUPP) {
PLOG(ERROR) << "Failed to write xattr " << inode_xattr << " at " << parent;
return -1;
} else {
return 0;
}
}
/**
* Read the inode of a specific child file from the given xattr on the
* parent directory. Returns a currently valid path for that child, which
* might have an encrypted name.
*/
std::string read_path_inode(const std::string& parent, const char* name, const char* inode_xattr) {
ino_t inode = 0;
uint64_t inode_raw = 0;
auto fallback = StringPrintf("%s/%s", parent.c_str(), name);
// Lookup the inode value written earlier
if (getxattr(parent.c_str(), inode_xattr, &inode_raw, sizeof(inode_raw)) == sizeof(inode_raw)) {
inode = inode_raw;
}
// For testing purposes, rely on the inode when defined; this could be
// optimized to use access() in the future.
if (inode != 0) {
DIR* dir = opendir(parent.c_str());
if (dir == nullptr) {
PLOG(ERROR) << "Failed to opendir " << parent;
return fallback;
}
struct dirent* ent;
while ((ent = readdir(dir))) {
if (ent->d_ino == inode) {
auto resolved = StringPrintf("%s/%s", parent.c_str(), ent->d_name);
#if DEBUG_XATTRS
if (resolved != fallback) {
LOG(DEBUG) << "Resolved path " << resolved << " for inode " << inode
<< " instead of " << fallback;
}
#endif
closedir(dir);
return resolved;
}
}
LOG(WARNING) << "Failed to resolve inode " << inode << "; using " << fallback;
closedir(dir);
return fallback;
} else {
return fallback;
}
}
/**
* Validate that the path is valid in the context of the provided directory.
* The path is allowed to have at most one subdirectory and no indirections
* to top level directories (i.e. have "..").
*/
static int validate_path(const dir_rec_t* dir, const char* path, int maxSubdirs) {
size_t dir_len = dir->len;
const char* subdir = strchr(path + dir_len, '/');
// Only allow the path to have at most one subdirectory.
if (subdir != NULL) {
++subdir;
if ((--maxSubdirs == 0) && strchr(subdir, '/') != NULL) {
ALOGE("invalid apk path '%s' (subdir?)\n", path);
return -1;
}
}
// Directories can't have a period directly after the directory markers to prevent "..".
if ((path[dir_len] == '.') || ((subdir != NULL) && (*subdir == '.'))) {
ALOGE("invalid apk path '%s' (trickery)\n", path);
return -1;
}
return 0;
}
/**
* Checks whether a path points to a system app (.apk file). Returns 0
* if it is a system app or -1 if it is not.
*/
int validate_system_app_path(const char* path) {
size_t i;
for (i = 0; i < android_system_dirs.count; i++) {
const size_t dir_len = android_system_dirs.dirs[i].len;
if (!strncmp(path, android_system_dirs.dirs[i].path, dir_len)) {
return validate_path(android_system_dirs.dirs + i, path, 1);
}
}
return -1;
}
bool validate_secondary_dex_path(const std::string& pkgname, const std::string& dex_path,
const char* volume_uuid, int uid, int storage_flag) {
CHECK(storage_flag == FLAG_STORAGE_CE || storage_flag == FLAG_STORAGE_DE);
std::string app_private_dir = storage_flag == FLAG_STORAGE_CE
? create_data_user_ce_package_path(
volume_uuid, multiuser_get_user_id(uid), pkgname.c_str())
: create_data_user_de_package_path(
volume_uuid, multiuser_get_user_id(uid), pkgname.c_str());
dir_rec_t dir;
if (get_path_from_string(&dir, app_private_dir.c_str()) != 0) {
LOG(WARNING) << "Could not get dir rec for " << app_private_dir;
return false;
}
// Usually secondary dex files have a nested directory structure.
// Pick at most 10 subdirectories when validating (arbitrary value).
// If the secondary dex file is >10 directory nested then validation will
// fail and the file will not be compiled.
return validate_path(&dir, dex_path.c_str(), /*max_subdirs*/ 10) == 0;
}
/**
* Get the contents of a environment variable that contains a path. Caller
* owns the string that is inserted into the directory record. Returns
* 0 on success and -1 on error.
*/
int get_path_from_env(dir_rec_t* rec, const char* var) {
const char* path = getenv(var);
int ret = get_path_from_string(rec, path);
if (ret < 0) {
ALOGW("Problem finding value for environment variable %s\n", var);
}
return ret;
}
/**
* Puts the string into the record as a directory. Appends '/' to the end
* of all paths. Caller owns the string that is inserted into the directory
* record. A null value will result in an error.
*
* Returns 0 on success and -1 on error.
*/
int get_path_from_string(dir_rec_t* rec, const char* path) {
if (path == NULL) {
return -1;
} else {
const size_t path_len = strlen(path);
if (path_len <= 0) {
return -1;
}
// Make sure path is absolute.
if (path[0] != '/') {
return -1;
}
if (path[path_len - 1] == '/') {
// Path ends with a forward slash. Make our own copy.
rec->path = strdup(path);
if (rec->path == NULL) {
return -1;
}
rec->len = path_len;
} else {
// Path does not end with a slash. Generate a new string.
char *dst;
// Add space for slash and terminating null.
size_t dst_size = path_len + 2;
rec->path = (char*) malloc(dst_size);
if (rec->path == NULL) {
return -1;
}
dst = rec->path;
if (append_and_increment(&dst, path, &dst_size) < 0
|| append_and_increment(&dst, "/", &dst_size)) {
ALOGE("Error canonicalizing path");
return -1;
}
rec->len = dst - rec->path;
}
}
return 0;
}
int copy_and_append(dir_rec_t* dst, const dir_rec_t* src, const char* suffix) {
dst->len = src->len + strlen(suffix);
const size_t dstSize = dst->len + 1;
dst->path = (char*) malloc(dstSize);
if (dst->path == NULL
|| snprintf(dst->path, dstSize, "%s%s", src->path, suffix)
!= (ssize_t) dst->len) {
ALOGE("Could not allocate memory to hold appended path; aborting\n");
return -1;
}
return 0;
}
/**
* Check whether path points to a valid path for an APK file. The path must
* begin with a whitelisted prefix path and must be no deeper than |maxSubdirs| within
* that path. Returns -1 when an invalid path is encountered and 0 when a valid path
* is encountered.
*/
static int validate_apk_path_internal(const char *path, int maxSubdirs) {
const dir_rec_t* dir = NULL;
if (!strncmp(path, android_app_dir.path, android_app_dir.len)) {
dir = &android_app_dir;
} else if (!strncmp(path, android_app_private_dir.path, android_app_private_dir.len)) {
dir = &android_app_private_dir;
} else if (!strncmp(path, android_app_ephemeral_dir.path, android_app_ephemeral_dir.len)) {
dir = &android_app_ephemeral_dir;
} else if (!strncmp(path, android_asec_dir.path, android_asec_dir.len)) {
dir = &android_asec_dir;
} else if (!strncmp(path, android_mnt_expand_dir.path, android_mnt_expand_dir.len)) {
dir = &android_mnt_expand_dir;
if (maxSubdirs < 2) {
maxSubdirs = 2;
}
} else {
return -1;
}
return validate_path(dir, path, maxSubdirs);
}
int validate_apk_path(const char* path) {
return validate_apk_path_internal(path, 1 /* maxSubdirs */);
}
int validate_apk_path_subdirs(const char* path) {
return validate_apk_path_internal(path, 3 /* maxSubdirs */);
}
int append_and_increment(char** dst, const char* src, size_t* dst_size) {
ssize_t ret = strlcpy(*dst, src, *dst_size);
if (ret < 0 || (size_t) ret >= *dst_size) {
return -1;
}
*dst += ret;
*dst_size -= ret;
return 0;
}
char *build_string2(const char *s1, const char *s2) {
if (s1 == NULL || s2 == NULL) return NULL;
int len_s1 = strlen(s1);
int len_s2 = strlen(s2);
int len = len_s1 + len_s2 + 1;
char *result = (char *) malloc(len);
if (result == NULL) return NULL;
strcpy(result, s1);
strcpy(result + len_s1, s2);
return result;
}
char *build_string3(const char *s1, const char *s2, const char *s3) {
if (s1 == NULL || s2 == NULL || s3 == NULL) return NULL;
int len_s1 = strlen(s1);
int len_s2 = strlen(s2);
int len_s3 = strlen(s3);
int len = len_s1 + len_s2 + len_s3 + 1;
char *result = (char *) malloc(len);
if (result == NULL) return NULL;
strcpy(result, s1);
strcpy(result + len_s1, s2);
strcpy(result + len_s1 + len_s2, s3);
return result;
}
int ensure_config_user_dirs(userid_t userid) {
// writable by system, readable by any app within the same user
const int uid = multiuser_get_uid(userid, AID_SYSTEM);
const int gid = multiuser_get_uid(userid, AID_EVERYBODY);
// Ensure /data/misc/user/<userid> exists
auto path = create_data_misc_legacy_path(userid);
return fs_prepare_dir(path.c_str(), 0750, uid, gid);
}
int wait_child(pid_t pid)
{
int status;
pid_t got_pid;
while (1) {
got_pid = waitpid(pid, &status, 0);
if (got_pid == -1 && errno == EINTR) {
printf("waitpid interrupted, retrying\n");
} else {
break;
}
}
if (got_pid != pid) {
ALOGW("waitpid failed: wanted %d, got %d: %s\n",
(int) pid, (int) got_pid, strerror(errno));
return 1;
}
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
return 0;
} else {
return status; /* always nonzero */
}
}
/**
* Prepare an app cache directory, which offers to fix-up the GID and
* directory mode flags during a platform upgrade.
* The app cache directory path will be 'parent'/'name'.
*/
int prepare_app_cache_dir(const std::string& parent, const char* name, mode_t target_mode,
uid_t uid, gid_t gid) {
auto path = StringPrintf("%s/%s", parent.c_str(), name);
struct stat st;
if (stat(path.c_str(), &st) != 0) {
if (errno == ENOENT) {
// This is fine, just create it
if (fs_prepare_dir_strict(path.c_str(), target_mode, uid, gid) != 0) {
PLOG(ERROR) << "Failed to prepare " << path;
return -1;
} else {
return 0;
}
} else {
PLOG(ERROR) << "Failed to stat " << path;
return -1;
}
}
mode_t actual_mode = st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO | S_ISGID);
if (st.st_uid != uid) {
// Mismatched UID is real trouble; we can't recover
LOG(ERROR) << "Mismatched UID at " << path << ": found " << st.st_uid
<< " but expected " << uid;
return -1;
} else if (st.st_gid == gid && actual_mode == target_mode) {
// Everything looks good!
return 0;
} else {
// Mismatched GID/mode is recoverable; fall through to update
LOG(DEBUG) << "Mismatched cache GID/mode at " << path << ": found " << st.st_gid
<< " but expected " << gid;
}
// Directory is owned correctly, but GID or mode mismatch means it's
// probably a platform upgrade so we need to fix them
FTS *fts;
FTSENT *p;
char *argv[] = { (char*) path.c_str(), nullptr };
if (!(fts = fts_open(argv, FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV, NULL))) {
PLOG(ERROR) << "Failed to fts_open " << path;
return -1;
}
while ((p = fts_read(fts)) != NULL) {
switch (p->fts_info) {
case FTS_DP:
if (chmod(p->fts_path, target_mode) != 0) {
PLOG(WARNING) << "Failed to chmod " << p->fts_path;
}
// Intentional fall through to also set GID
case FTS_F:
if (chown(p->fts_path, -1, gid) != 0) {
PLOG(WARNING) << "Failed to chown " << p->fts_path;
}
break;
case FTS_SL:
case FTS_SLNONE:
if (lchown(p->fts_path, -1, gid) != 0) {
PLOG(WARNING) << "Failed to chown " << p->fts_path;
}
break;
}
}
fts_close(fts);
return 0;
}
} // namespace installd
} // namespace android