libbinder: add ancillaryFd support in RpcTransportTipcTrusty (1c18a808) · Commits · e / os / android_frameworks_native

libs/binder/Parcel.cpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -1439,7 +1439,8 @@ status_t Parcel::writeFileDescriptor(int fd, bool takeOwnership) {
		case RpcSession::FileDescriptorTransportMode::NONE: {
		return FDS_NOT_ALLOWED;
		}
		case RpcSession::FileDescriptorTransportMode::UNIX: {
		case RpcSession::FileDescriptorTransportMode::UNIX:
		case RpcSession::FileDescriptorTransportMode::TRUSTY: {
		if (rpcFields->mFds == nullptr) {
		rpcFields->mFds = std::make_unique<decltype(rpcFields->mFds)::element_type>();
		}

libs/binder/RpcState.cpp

+15 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,7 @@ static bool enableAncillaryFds(RpcSession::FileDescriptorTransportMode mode) {
		case RpcSession::FileDescriptorTransportMode::NONE:
		return false;
		case RpcSession::FileDescriptorTransportMode::UNIX:
		case RpcSession::FileDescriptorTransportMode::TRUSTY:
		return true;
		}
		}
		@@ -1205,6 +1206,20 @@ status_t RpcState::validateParcel(const sp<RpcSession>& session, const Parcel& p
		rpcFields->mFds->size(), kMaxFdsPerMsg);
		return BAD_VALUE;
		}
		break;
		}
		case RpcSession::FileDescriptorTransportMode::TRUSTY: {
		// Keep this in sync with trusty_ipc.h!!!
		// We could import that file here on Trusty, but it's not
		// available on Android
		constexpr size_t kMaxFdsPerMsg = 8;
		if (rpcFields->mFds->size() > kMaxFdsPerMsg) {
		*errorMsg = StringPrintf("Too many file descriptors in Parcel for Trusty "
		"IPC connection: %zu (max is %zu)",
		rpcFields->mFds->size(), kMaxFdsPerMsg);
		return BAD_VALUE;
		}
		break;
		}
		}
		}

libs/binder/include/binder/RpcSession.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -100,6 +100,8 @@ public:
		NONE = 0,
		// Send file descriptors via unix domain socket ancillary data.
		UNIX = 1,
		// Send file descriptors as Trusty IPC handles.
		TRUSTY = 2,
		};

		/**

libs/binder/trusty/OS.cpp

+10 −3

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@

		#if defined(TRUSTY_USERSPACE)
		#include <openssl/rand.h>
		#include <trusty_ipc.h>
		#else
		#include <lib/rand/rand.h>
		#endif
		@@ -23,6 +24,7 @@
		#include <binder/RpcTransportTipcTrusty.h>

		#include "../OS.h"
		#include "TrustyStatus.h"

		using android::base::Result;

		@@ -43,9 +45,14 @@ status_t getRandomBytes(uint8_t* data, size_t size) {
		#endif // TRUSTY_USERSPACE
		}

		status_t dupFileDescriptor(int /oldFd/, int* /newFd/) {
		// TODO: implement separately
		return INVALID_OPERATION;
		status_t dupFileDescriptor(int oldFd, int* newFd) {
		int res = dup(oldFd);
		if (res < 0) {
		return statusFromTrusty(res);
		}

		*newFd = res;
		return OK;
		}

		std::unique_ptr<RpcTransportCtxFactory> makeDefaultRpcTransportCtxFactory() {

libs/binder/trusty/RpcTransportTipcTrusty.cpp

+53 −6

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@

		#define LOG_TAG "RpcTransportTipcTrusty"

		#include <inttypes.h>
		#include <trusty_ipc.h>

		#include <binder/RpcSession.h>
		@@ -47,7 +48,7 @@ public:
		status_t interruptableWriteFully(
		FdTrigger* /fdTrigger/, iovec* iovs, int niovs,
		const std::optional<android::base::function_ref<status_t()>>& /altPoll/,
		const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* /ancillaryFds/)
		const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds)
		override {
		if (niovs < 0) {
		return BAD_VALUE;
		@@ -58,12 +59,32 @@ public:
		size += iovs[i].iov_len;
		}

		handle_t msgHandles[IPC_MAX_MSG_HANDLES];
		ipc_msg_t msg{
		.num_iov = static_cast<uint32_t>(niovs),
		.iov = iovs,
		.num_handles = 0, // TODO: add ancillaryFds
		.num_handles = 0,
		.handles = nullptr,
		};

		if (ancillaryFds != nullptr && !ancillaryFds->empty()) {
		if (ancillaryFds->size() > IPC_MAX_MSG_HANDLES) {
		// This shouldn't happen because we check the FD count in RpcState.
		ALOGE("Saw too many file descriptors in RpcTransportCtxTipcTrusty: "
		"%zu (max is %u). Aborting session.",
		ancillaryFds->size(), IPC_MAX_MSG_HANDLES);
		return BAD_VALUE;
		}

		for (size_t i = 0; i < ancillaryFds->size(); i++) {
		msgHandles[i] =
		std::visit([](const auto& fd) { return fd.get(); }, ancillaryFds->at(i));
		}

		msg.num_handles = ancillaryFds->size();
		msg.handles = msgHandles;
		}

		ssize_t rc = send_msg(mSocket.fd.get(), &msg);
		if (rc == ERR_NOT_ENOUGH_BUFFER) {
		// Peer is blocked, wait until it unblocks.
		@@ -97,8 +118,7 @@ public:
		status_t interruptableReadFully(
		FdTrigger* /fdTrigger/, iovec* iovs, int niovs,
		const std::optional<android::base::function_ref<status_t()>>& /altPoll/,
		std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* /ancillaryFds/)
		override {
		std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) override {
		if (niovs < 0) {
		return BAD_VALUE;
		}
		@@ -124,11 +144,16 @@ public:
		return status;
		}

		LOG_ALWAYS_FATAL_IF(mMessageInfo.num_handles > IPC_MAX_MSG_HANDLES,
		"Received too many handles %" PRIu32, mMessageInfo.num_handles);
		bool haveHandles = mMessageInfo.num_handles != 0;
		handle_t msgHandles[IPC_MAX_MSG_HANDLES];

		ipc_msg_t msg{
		.num_iov = static_cast<uint32_t>(niovs),
		.iov = iovs,
		.num_handles = 0, // TODO: support ancillaryFds
		.handles = nullptr,
		.num_handles = mMessageInfo.num_handles,
		.handles = haveHandles ? msgHandles : 0,
		};
		ssize_t rc = read_msg(mSocket.fd.get(), mMessageInfo.id, mMessageOffset, &msg);
		if (rc < 0) {
		@@ -141,6 +166,28 @@ public:
		"Message offset exceeds length %zu/%zu", mMessageOffset,
		mMessageInfo.len);

		if (haveHandles) {
		if (ancillaryFds != nullptr) {
		ancillaryFds->reserve(ancillaryFds->size() + mMessageInfo.num_handles);
		for (size_t i = 0; i < mMessageInfo.num_handles; i++) {
		ancillaryFds->emplace_back(base::unique_fd(msgHandles[i]));
		}

		// Clear the saved number of handles so we don't accidentally
		// read them multiple times
		mMessageInfo.num_handles = 0;
		haveHandles = false;
		} else {
		ALOGE("Received unexpected handles %" PRIu32, mMessageInfo.num_handles);
		// It should be safe to continue here. We could abort, but then
		// peers could DoS us by sending messages with handles in them.
		// Close the handles since we are ignoring them.
		for (size_t i = 0; i < mMessageInfo.num_handles; i++) {
		::close(msgHandles[i]);
		}
		}
		}

		// Release the message if all of it has been read
		if (mMessageOffset == mMessageInfo.len) {
		releaseMessage();