commit 53947a36629425f9e63f9c422e567fd0a6c19dfc
author Sudheer Shanka <sudheersai@google.com> Wed Aug 01 10:24:13 2018 -0700
committer Sudheer Shanka <sudheersai@google.com> Wed Aug 01 10:24:13 2018 -0700
tree e2e9a36e70322b19c097ae37e93ebb529990b853
parent 62bbb2b1d204dd3ee09d7082bbe89e7f8d2c52d6

Update vold to prepare package sandboxes for primary volume.

Vold is updated to create package specific sandboxes for primary
volume and mount them at
"/mnt/user/<user-id>/package/<package-name>/<primary-label>".
This will later be mounted at /storage when a new process starts.

Bug: 111890351
Test: Manually verified that a package has access to "/sdcard" and
      "/storage/emulated/0", both of which are just the package specific
      sandboxes and the package doesn't have access to other sandboxes
      and can't see other package names.

Change-Id: I72dc8ae9eb2260a298159c5de18387dad2f9de48

model/EmulatedVolume.cpp

diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index 6e1ffce..25ea602 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -17,8 +17,8 @@
 #include "EmulatedVolume.h"
 #include "Utils.h"
 
-#include <android-base/stringprintf.h>
 #include <android-base/logging.h>
+#include <android-base/stringprintf.h>
 #include <cutils/fs.h>
 #include <private/android_filesystem_config.h>
 #include <utils/Timers.h>
@@ -69,6 +69,7 @@
 
     setInternalPath(mRawPath);
     setPath(StringPrintf("/storage/%s", label.c_str()));
+    setLabel(label);
 
     if (fs_prepare_dir(mFuseDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
             fs_prepare_dir(mFuseRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||

model/PublicVolume.cpp

diff --git a/model/PublicVolume.cpp b/model/PublicVolume.cpp
index 9f2ed85..4076e73 100644
--- a/model/PublicVolume.cpp
+++ b/model/PublicVolume.cpp
@@ -129,6 +129,7 @@
     } else {
         setPath(mRawPath);
     }
+    setLabel(stableName);
 
     if (fs_prepare_dir(mRawPath.c_str(), 0700, AID_ROOT, AID_ROOT)) {
         PLOG(ERROR) << getId() << " failed to create mount points";

model/VolumeBase.cpp

diff --git a/model/VolumeBase.cpp b/model/VolumeBase.cpp
index 429f134..cf3d54e 100644
--- a/model/VolumeBase.cpp
+++ b/model/VolumeBase.cpp
@@ -136,6 +136,16 @@
     return OK;
 }
 
+status_t VolumeBase::setLabel(const std::string& label) {
+    if (mState != State::kChecking) {
+        LOG(WARNING) << getId() << " label change requires state checking";
+        return -EBUSY;
+    }
+
+    mLabel = label;
+    return OK;
+}
+
 android::sp<android::os::IVoldListener> VolumeBase::getListener() {
     if (mSilent) {
         return nullptr;

model/VolumeBase.h

diff --git a/model/VolumeBase.h b/model/VolumeBase.h
index 4aa8b02..2052c15 100644
--- a/model/VolumeBase.h
+++ b/model/VolumeBase.h
@@ -84,6 +84,7 @@
     State getState() { return mState; }
     const std::string& getPath() { return mPath; }
     const std::string& getInternalPath() { return mInternalPath; }
+    const std::string& getLabel() { return mLabel; }
 
     status_t setDiskId(const std::string& diskId);
     status_t setPartGuid(const std::string& partGuid);
@@ -114,6 +115,7 @@
     status_t setId(const std::string& id);
     status_t setPath(const std::string& path);
     status_t setInternalPath(const std::string& internalPath);
+    status_t setLabel(const std::string& label);
 
     android::sp<android::os::IVoldListener> getListener();
 
@@ -140,6 +142,12 @@
     std::string mInternalPath;
     /* Flag indicating that volume should emit no events */
     bool mSilent;
+    /**
+     * Label used for representing the package sandboxes on external storage volumes.
+     * For emulated volume, this would be "emulated" and for public volumes, UUID if available,
+     * otherwise some other unique id.
+     */
+    std::string mLabel;
 
     /* Volumes stacked on top of this volume */
     std::list<std::shared_ptr<VolumeBase>> mVolumes;