Introduce new command callback to shell.
This introduces a new feature of the IBinder command protocol
to allow the shell command implementation to call back into
its caller to ask it to open files in the calling context. This
is needed so that commands that have arguments specifying files
can open those files as the calling shell, not the system (or
whatever) process.
Test: Manual
Change-Id: Idd5b49ea21057864cc9cef816b3e4afbf01948fc
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 4780757..175e982 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -32,6 +32,7 @@
"IProcessInfoService.cpp",
"IResultReceiver.cpp",
"IServiceManager.cpp",
+ "IShellCallback.cpp",
"MemoryBase.cpp",
"MemoryDealer.cpp",
"MemoryHeapBase.cpp",
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 7ce2a31..890ef30 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -21,6 +21,7 @@
#include <binder/BpBinder.h>
#include <binder/IInterface.h>
#include <binder/IResultReceiver.h>
+#include <binder/IShellCallback.h>
#include <binder/Parcel.h>
#include <stdio.h>
@@ -62,7 +63,8 @@
status_t IBinder::shellCommand(const sp<IBinder>& target, int in, int out, int err,
- Vector<String16>& args, const sp<IResultReceiver>& resultReceiver)
+ Vector<String16>& args, const sp<IShellCallback>& callback,
+ const sp<IResultReceiver>& resultReceiver)
{
Parcel send;
Parcel reply;
@@ -74,6 +76,7 @@
for (size_t i = 0; i < numArgs; i++) {
send.writeString16(args[i]);
}
+ send.writeStrongBinder(callback != NULL ? IInterface::asBinder(callback) : NULL);
send.writeStrongBinder(resultReceiver != NULL ? IInterface::asBinder(resultReceiver) : NULL);
return target->transact(SHELL_COMMAND_TRANSACTION, send, &reply);
}
@@ -232,6 +235,8 @@
for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
args.add(data.readString16());
}
+ sp<IShellCallback> shellCallback = IShellCallback::asInterface(
+ data.readStrongBinder());
sp<IResultReceiver> resultReceiver = IResultReceiver::asInterface(
data.readStrongBinder());
diff --git a/libs/binder/IShellCallback.cpp b/libs/binder/IShellCallback.cpp
new file mode 100644
index 0000000..8b97301
--- /dev/null
+++ b/libs/binder/IShellCallback.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#define LOG_TAG "ShellCallback"
+
+#include <binder/IShellCallback.h>
+
+#include <utils/Log.h>
+#include <binder/Parcel.h>
+#include <utils/String8.h>
+
+#include <private/binder/Static.h>
+
+namespace android {
+
+// ----------------------------------------------------------------------
+
+class BpShellCallback : public BpInterface<IShellCallback>
+{
+public:
+ explicit BpShellCallback(const sp<IBinder>& impl)
+ : BpInterface<IShellCallback>(impl)
+ {
+ }
+
+ virtual int openOutputFile(const String16& path, const String16& seLinuxContext) {
+ Parcel data, reply;
+ data.writeInterfaceToken(IShellCallback::getInterfaceDescriptor());
+ data.writeString16(path);
+ data.writeString16(seLinuxContext);
+ remote()->transact(OP_OPEN_OUTPUT_FILE, data, &reply, 0);
+ reply.readExceptionCode();
+ int fd = reply.readParcelFileDescriptor();
+ return fd >= 0 ? dup(fd) : fd;
+
+ }
+};
+
+IMPLEMENT_META_INTERFACE(ShellCallback, "com.android.internal.os.IShellCallback");
+
+// ----------------------------------------------------------------------
+
+status_t BnShellCallback::onTransact(
+ uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
+{
+ switch(code) {
+ case OP_OPEN_OUTPUT_FILE: {
+ CHECK_INTERFACE(IShellCallback, data, reply);
+ String16 path(data.readString16());
+ String16 seLinuxContext(data.readString16());
+ int fd = openOutputFile(path, seLinuxContext);
+ if (reply != NULL) {
+ reply->writeNoException();
+ if (fd >= 0) {
+ reply->writeInt32(1);
+ reply->writeParcelFileDescriptor(fd, true);
+ } else {
+ reply->writeInt32(0);
+ }
+ } else if (fd >= 0) {
+ close(fd);
+ }
+ return NO_ERROR;
+ } break;
+ default:
+ return BBinder::onTransact(code, data, reply, flags);
+ }
+}
+
+}; // namespace android
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 572c284..601df46 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -1153,6 +1153,12 @@
return err;
}
+status_t Parcel::writeParcelFileDescriptor(int fd, bool takeOwnership)
+{
+ writeInt32(0);
+ return writeFileDescriptor(fd, takeOwnership);
+}
+
status_t Parcel::writeUniqueFileDescriptor(const base::unique_fd& fd) {
return writeDupFileDescriptor(fd.get());
}
@@ -1984,7 +1990,6 @@
return h;
}
-
int Parcel::readFileDescriptor() const
{
const flat_binder_object* flat = readObject(true);
@@ -1996,6 +2001,17 @@
return BAD_TYPE;
}
+int Parcel::readParcelFileDescriptor() const
+{
+ int32_t hasComm = readInt32();
+ int fd = readFileDescriptor();
+ if (hasComm != 0) {
+ // skip
+ readFileDescriptor();
+ }
+ return fd;
+}
+
status_t Parcel::readUniqueFileDescriptor(base::unique_fd* val) const
{
int got = readFileDescriptor();