sdcard: Fix bad merge
A few changes got dropped along merge resolution. This adds them back
Affected CLs:
Ie188cb044be2ad87166f2d43c32a1f6b97660de0
Ibdb72ad16a1e6c3a01edcb03d003c42de7a03cd6
Change-Id: I1924f5a4bd7564ceaf9bb3a45b7fb7804b3619d7
diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index 3481ec3..70bbf26 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -28,11 +28,16 @@
#include <sys/types.h>
#include <unistd.h>
+#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/macros.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
#include <cutils/fs.h>
#include <cutils/multiuser.h>
+#include <cutils/properties.h>
+
#include <packagelistparser/packagelistparser.h>
#include <libminijail.h>
@@ -73,6 +78,9 @@
#include "fuse.h"
+#define PROP_SDCARDFS_DEVICE "ro.sys.sdcardfs"
+#define PROP_SDCARDFS_USER "persist.sys.sdcardfs"
+
/* Supplementary groups to execute with. */
static const gid_t kGroups[1] = { AID_PACKAGE_INFO };
@@ -307,6 +315,98 @@
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);
+
+ if (mount(source_path.c_str(), dest_path.c_str(), "sdcardfs",
+ MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()) != 0) {
+ PLOG(ERROR) << "failed to mount sdcardfs filesystem";
+ return false;
+ }
+
+ return true;
+}
+
+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) {
+ 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;
+
+ umask(0);
+ if (multi_user) {
+ // 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(source_path, dest_path_read, uid, gid, multi_user, userid,
+ AID_EVERYBODY, 0027)
+ || !sdcardfs_setup(source_path, dest_path_write, uid, gid, multi_user, userid,
+ AID_EVERYBODY, full_write ? 0007 : 0027)) {
+ LOG(FATAL) << "failed to sdcardfs_setup";
+ }
+ } else {
+ // Physical storage is readable by all users on device, but
+ // 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(source_path, dest_path_read, uid, gid, multi_user, userid,
+ AID_EVERYBODY, full_write ? 0027 : 0022)
+ || !sdcardfs_setup(source_path, dest_path_write, uid, gid, multi_user, userid,
+ AID_EVERYBODY, full_write ? 0007 : 0022)) {
+ LOG(FATAL) << "failed to sdcardfs_setup";
+ }
+ }
+
+ // Will abort if priv-dropping fails.
+ drop_privs(uid, gid);
+
+ if (multi_user) {
+ std::string obb_path = source_path + "/obb";
+ fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
+ }
+
+ exit(0);
+}
+
+static bool supports_sdcardfs(void) {
+ std::string filesystems;
+ if (!android::base::ReadFileToString("/proc/filesystems", &filesystems)) {
+ PLOG(ERROR) << "Could not read /proc/filesystems";
+ return false;
+ }
+ for (const auto& fs : android::base::Split(filesystems, "\n")) {
+ if (fs.find("sdcardfs") != std::string::npos) return true;
+ }
+ return false;
+}
+
+static bool should_use_sdcardfs(void) {
+ char property[PROPERTY_VALUE_MAX];
+
+ // Allow user to have a strong opinion about state
+ property_get(PROP_SDCARDFS_USER, property, "");
+ if (!strcmp(property, "force_on")) {
+ LOG(WARNING) << "User explicitly enabled sdcardfs";
+ return supports_sdcardfs();
+ } else if (!strcmp(property, "force_off")) {
+ LOG(WARNING) << "User explicitly disabled sdcardfs";
+ return false;
+ }
+
+ // Fall back to device opinion about state
+ if (property_get_bool(PROP_SDCARDFS_DEVICE, false)) {
+ LOG(WARNING) << "Device explicitly enabled sdcardfs";
+ return supports_sdcardfs();
+ } else {
+ LOG(WARNING) << "Device explicitly disabled sdcardfs";
+ return false;
+ }
+}
+
static int usage() {
LOG(ERROR) << "usage: sdcard [OPTIONS] <source_path> <label>"
<< " -u: specify UID to run as"
@@ -389,6 +489,10 @@
sleep(1);
}
- run(source_path, label, uid, gid, userid, multi_user, full_write);
+ if (should_use_sdcardfs()) {
+ run_sdcardfs(source_path, label, uid, gid, userid, multi_user, full_write);
+ } else {
+ run(source_path, label, uid, gid, userid, multi_user, full_write);
+ }
return 1;
}