Dianne Hackborn d0c5f515c0 Fix issue #6295373: "Package com.google.android.apps.authenticator2 has...
...mismatched uid: X on disk, Y in settings" errors on Froyo and Gingerbread

Deal more gracefully with the uid changing in three ways:

1. If the uid on disk has become root, then have installd change it to
   the application's uid.  This is to correct a potential case where
   installd was interrupted while linking or unlinking the libs dir,
   during which it temporarily changes the owner of the dir to root
   so that a malicious app can not get in its way.  So if the uid on
   disk has become root, we assume we can safely just change it back
   to the correct uid.

2. When scaning packages at boot, use the same "delete and rebuild data
   directory" code for third party applications as we have for system
   applications.  This allows us to at least end up in a state where the
   app will run, even if its data is lost.

3. But we really don't want to get in to case 2, so if an application
   update is being installed and we find that the uid we now have for
   the app is different than the one on disk, fail the update.  This will
   protect against for example a developer changing the sharedUserId of
   their app and getting into this bad state.

Bug: 6295373
Change-Id: Ic802fdd818ac62449ff3c61d1fff1aa4d4942f39
2012-06-07 16:57:57 -07:00

422 lines
12 KiB
C

/*
** 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 "installd.h"
#define BUFFER_MAX 1024 /* input buffer for commands */
#define TOKEN_MAX 8 /* max number of arguments in buffer */
#define REPLY_MAX 256 /* largest reply allowed */
static int do_ping(char **arg, char reply[REPLY_MAX])
{
return 0;
}
static int do_install(char **arg, char reply[REPLY_MAX])
{
return install(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
}
static int do_dexopt(char **arg, char reply[REPLY_MAX])
{
/* apk_path, uid, is_public */
return dexopt(arg[0], atoi(arg[1]), atoi(arg[2]));
}
static int do_move_dex(char **arg, char reply[REPLY_MAX])
{
return move_dex(arg[0], arg[1]); /* src, dst */
}
static int do_rm_dex(char **arg, char reply[REPLY_MAX])
{
return rm_dex(arg[0]); /* pkgname */
}
static int do_remove(char **arg, char reply[REPLY_MAX])
{
return uninstall(arg[0], atoi(arg[1])); /* pkgname, userid */
}
static int do_rename(char **arg, char reply[REPLY_MAX])
{
return renamepkg(arg[0], arg[1]); /* oldpkgname, newpkgname */
}
static int do_fixuid(char **arg, char reply[REPLY_MAX])
{
return fix_uid(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
}
static int do_free_cache(char **arg, char reply[REPLY_MAX]) /* TODO int:free_size */
{
return free_cache((int64_t)atoll(arg[0])); /* free_size */
}
static int do_rm_cache(char **arg, char reply[REPLY_MAX])
{
return delete_cache(arg[0]); /* pkgname */
}
static int do_protect(char **arg, char reply[REPLY_MAX])
{
return protect(arg[0], atoi(arg[1])); /* pkgname, gid */
}
static int do_get_size(char **arg, char reply[REPLY_MAX])
{
int64_t codesize = 0;
int64_t datasize = 0;
int64_t cachesize = 0;
int64_t asecsize = 0;
int res = 0;
/* pkgdir, apkpath */
res = get_size(arg[0], arg[1], arg[2], arg[3], &codesize, &datasize, &cachesize, &asecsize);
/*
* Each int64_t can take up 22 characters printed out. Make sure it
* doesn't go over REPLY_MAX in the future.
*/
snprintf(reply, REPLY_MAX, "%" PRId64 " %" PRId64 " %" PRId64 " %" PRId64,
codesize, datasize, cachesize, asecsize);
return res;
}
static int do_rm_user_data(char **arg, char reply[REPLY_MAX])
{
return delete_user_data(arg[0], atoi(arg[1])); /* pkgname, userid */
}
static int do_mk_user_data(char **arg, char reply[REPLY_MAX])
{
return make_user_data(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, userid */
}
static int do_rm_user(char **arg, char reply[REPLY_MAX])
{
return delete_persona(atoi(arg[0])); /* userid */
}
static int do_clone_user_data(char **arg, char reply[REPLY_MAX])
{
return clone_persona_data(atoi(arg[0]), atoi(arg[1]), atoi(arg[2]));
}
static int do_movefiles(char **arg, char reply[REPLY_MAX])
{
return movefiles();
}
static int do_linklib(char **arg, char reply[REPLY_MAX])
{
return linklib(arg[0], arg[1]);
}
static int do_unlinklib(char **arg, char reply[REPLY_MAX])
{
return unlinklib(arg[0]);
}
struct cmdinfo {
const char *name;
unsigned numargs;
int (*func)(char **arg, char reply[REPLY_MAX]);
};
struct cmdinfo cmds[] = {
{ "ping", 0, do_ping },
{ "install", 3, do_install },
{ "dexopt", 3, do_dexopt },
{ "movedex", 2, do_move_dex },
{ "rmdex", 1, do_rm_dex },
{ "remove", 2, do_remove },
{ "rename", 2, do_rename },
{ "fixuid", 3, do_fixuid },
{ "freecache", 1, do_free_cache },
{ "rmcache", 1, do_rm_cache },
{ "protect", 2, do_protect },
{ "getsize", 4, do_get_size },
{ "rmuserdata", 2, do_rm_user_data },
{ "movefiles", 0, do_movefiles },
{ "linklib", 2, do_linklib },
{ "unlinklib", 1, do_unlinklib },
{ "mkuserdata", 3, do_mk_user_data },
{ "rmuser", 1, do_rm_user },
{ "cloneuserdata", 3, do_clone_user_data },
};
static int readx(int s, void *_buf, int count)
{
char *buf = _buf;
int n = 0, r;
if (count < 0) return -1;
while (n < count) {
r = read(s, buf + n, count - n);
if (r < 0) {
if (errno == EINTR) continue;
ALOGE("read error: %s\n", strerror(errno));
return -1;
}
if (r == 0) {
ALOGE("eof\n");
return -1; /* EOF */
}
n += r;
}
return 0;
}
static int writex(int s, const void *_buf, int count)
{
const char *buf = _buf;
int n = 0, r;
if (count < 0) return -1;
while (n < count) {
r = write(s, buf + n, count - n);
if (r < 0) {
if (errno == EINTR) continue;
ALOGE("write error: %s\n", strerror(errno));
return -1;
}
n += r;
}
return 0;
}
/* Tokenize the command buffer, locate a matching command,
* ensure that the required number of arguments are provided,
* call the function(), return the result.
*/
static int execute(int s, char cmd[BUFFER_MAX])
{
char reply[REPLY_MAX];
char *arg[TOKEN_MAX+1];
unsigned i;
unsigned n = 0;
unsigned short count;
int ret = -1;
// ALOGI("execute('%s')\n", cmd);
/* default reply is "" */
reply[0] = 0;
/* n is number of args (not counting arg[0]) */
arg[0] = cmd;
while (*cmd) {
if (isspace(*cmd)) {
*cmd++ = 0;
n++;
arg[n] = cmd;
if (n == TOKEN_MAX) {
ALOGE("too many arguments\n");
goto done;
}
}
cmd++;
}
for (i = 0; i < sizeof(cmds) / sizeof(cmds[0]); i++) {
if (!strcmp(cmds[i].name,arg[0])) {
if (n != cmds[i].numargs) {
ALOGE("%s requires %d arguments (%d given)\n",
cmds[i].name, cmds[i].numargs, n);
} else {
ret = cmds[i].func(arg + 1, reply);
}
goto done;
}
}
ALOGE("unsupported command '%s'\n", arg[0]);
done:
if (reply[0]) {
n = snprintf(cmd, BUFFER_MAX, "%d %s", ret, reply);
} else {
n = snprintf(cmd, BUFFER_MAX, "%d", ret);
}
if (n > BUFFER_MAX) n = BUFFER_MAX;
count = n;
// ALOGI("reply: '%s'\n", cmd);
if (writex(s, &count, sizeof(count))) return -1;
if (writex(s, cmd, count)) return -1;
return 0;
}
/**
* Initialize all the global variables that are used elsewhere. Returns 0 upon
* success and -1 on error.
*/
void free_globals() {
size_t i;
for (i = 0; i < android_system_dirs.count; i++) {
if (android_system_dirs.dirs[i].path != NULL) {
free(android_system_dirs.dirs[i].path);
}
}
free(android_system_dirs.dirs);
}
int initialize_globals() {
// Get the android data directory.
if (get_path_from_env(&android_data_dir, "ANDROID_DATA") < 0) {
return -1;
}
// Get the android app directory.
if (copy_and_append(&android_app_dir, &android_data_dir, APP_SUBDIR) < 0) {
return -1;
}
// Get the android protected app directory.
if (copy_and_append(&android_app_private_dir, &android_data_dir, PRIVATE_APP_SUBDIR) < 0) {
return -1;
}
// Get the sd-card ASEC mount point.
if (get_path_from_env(&android_asec_dir, "ASEC_MOUNTPOINT") < 0) {
return -1;
}
// Take note of the system and vendor directories.
android_system_dirs.count = 2;
android_system_dirs.dirs = calloc(android_system_dirs.count, sizeof(dir_rec_t));
if (android_system_dirs.dirs == NULL) {
ALOGE("Couldn't allocate array for dirs; aborting\n");
return -1;
}
// system
if (get_path_from_env(&android_system_dirs.dirs[0], "ANDROID_ROOT") < 0) {
free_globals();
return -1;
}
// append "app/" to dirs[0]
char *system_app_path = build_string2(android_system_dirs.dirs[0].path, APP_SUBDIR);
android_system_dirs.dirs[0].path = system_app_path;
android_system_dirs.dirs[0].len = strlen(system_app_path);
// vendor
// TODO replace this with an environment variable (doesn't exist yet)
android_system_dirs.dirs[1].path = "/vendor/app/";
android_system_dirs.dirs[1].len = strlen(android_system_dirs.dirs[1].path);
return 0;
}
int initialize_directories() {
// /data/user
char *user_data_dir = build_string2(android_data_dir.path, SECONDARY_USER_PREFIX);
// /data/data
char *legacy_data_dir = build_string2(android_data_dir.path, PRIMARY_USER_PREFIX);
// /data/user/0
char *primary_data_dir = build_string3(android_data_dir.path, SECONDARY_USER_PREFIX,
"0");
int ret = -1;
if (user_data_dir != NULL && primary_data_dir != NULL && legacy_data_dir != NULL) {
ret = 0;
// Make the /data/user directory if necessary
if (access(user_data_dir, R_OK) < 0) {
if (mkdir(user_data_dir, 0711) < 0) {
return -1;
}
if (chown(user_data_dir, AID_SYSTEM, AID_SYSTEM) < 0) {
return -1;
}
if (chmod(user_data_dir, 0711) < 0) {
return -1;
}
}
// Make the /data/user/0 symlink to /data/data if necessary
if (access(primary_data_dir, R_OK) < 0) {
ret = symlink(legacy_data_dir, primary_data_dir);
}
free(user_data_dir);
free(legacy_data_dir);
free(primary_data_dir);
}
return ret;
}
int main(const int argc, const char *argv[]) {
char buf[BUFFER_MAX];
struct sockaddr addr;
socklen_t alen;
int lsocket, s, count;
if (initialize_globals() < 0) {
ALOGE("Could not initialize globals; exiting.\n");
exit(1);
}
if (initialize_directories() < 0) {
ALOGE("Could not create directories; exiting.\n");
exit(1);
}
lsocket = android_get_control_socket(SOCKET_PATH);
if (lsocket < 0) {
ALOGE("Failed to get socket from environment: %s\n", strerror(errno));
exit(1);
}
if (listen(lsocket, 5)) {
ALOGE("Listen on socket failed: %s\n", strerror(errno));
exit(1);
}
fcntl(lsocket, F_SETFD, FD_CLOEXEC);
for (;;) {
alen = sizeof(addr);
s = accept(lsocket, &addr, &alen);
if (s < 0) {
ALOGE("Accept failed: %s\n", strerror(errno));
continue;
}
fcntl(s, F_SETFD, FD_CLOEXEC);
ALOGI("new connection\n");
for (;;) {
unsigned short count;
if (readx(s, &count, sizeof(count))) {
ALOGE("failed to read size\n");
break;
}
if ((count < 1) || (count >= BUFFER_MAX)) {
ALOGE("invalid size %d\n", count);
break;
}
if (readx(s, buf, count)) {
ALOGE("failed to read command\n");
break;
}
buf[count] = 0;
if (execute(s, buf)) break;
}
ALOGI("closing connection\n");
close(s);
}
return 0;
}