libbinder: Session ID implemented directly.
In preparation for removing RpcAddress.
Bug: 182940634
Test: binderRpcTest (w & w/o LOG_RPC_DETAIL)
Change-Id: I945e650bbab9f8df4f785b689983b62c59bb8674
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index ad9ba96..ad04702 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -23,6 +23,8 @@
#include <thread>
#include <vector>
+#include <android-base/file.h>
+#include <android-base/hex.h>
#include <android-base/scopeguard.h>
#include <binder/Parcel.h>
#include <binder/RpcServer.h>
@@ -290,17 +292,29 @@
}
}
+ std::vector<uint8_t> sessionId;
+ if (status == OK) {
+ if (header.sessionIdSize > 0) {
+ sessionId.resize(header.sessionIdSize);
+ status = client->interruptableReadFully(server->mShutdownTrigger.get(),
+ sessionId.data(), sessionId.size());
+ if (status != OK) {
+ ALOGE("Failed to read session ID for client connecting to RPC server: %s",
+ statusToString(status).c_str());
+ // still need to cleanup before we can return
+ }
+ }
+ }
+
bool incoming = false;
uint32_t protocolVersion = 0;
- RpcAddress sessionId = RpcAddress::zero();
bool requestingNewSession = false;
if (status == OK) {
incoming = header.options & RPC_CONNECTION_OPTION_INCOMING;
protocolVersion = std::min(header.version,
server->mProtocolVersion.value_or(RPC_WIRE_PROTOCOL_VERSION));
- sessionId = RpcAddress::fromRawEmbedded(&header.sessionId);
- requestingNewSession = sessionId.isZero();
+ requestingNewSession = sessionId.empty();
if (requestingNewSession) {
RpcNewSessionResponse response{
@@ -342,15 +356,26 @@
return;
}
+ // Uniquely identify session at the application layer. Even if a
+ // client/server use the same certificates, if they create multiple
+ // sessions, we still want to distinguish between them.
+ constexpr size_t kSessionIdSize = 32;
+ sessionId.resize(kSessionIdSize);
size_t tries = 0;
do {
// don't block if there is some entropy issue
if (tries++ > 5) {
- ALOGE("Cannot find new address: %s", sessionId.toString().c_str());
+ ALOGE("Cannot find new address: %s",
+ base::HexString(sessionId.data(), sessionId.size()).c_str());
return;
}
- sessionId = RpcAddress::random(true /*forServer*/);
+ base::unique_fd fd(TEMP_FAILURE_RETRY(
+ open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOFOLLOW)));
+ if (!base::ReadFully(fd, sessionId.data(), sessionId.size())) {
+ ALOGE("Could not read from /dev/urandom to create session ID");
+ return;
+ }
} while (server->mSessions.end() != server->mSessions.find(sessionId));
session = RpcSession::make();
@@ -370,7 +395,7 @@
auto it = server->mSessions.find(sessionId);
if (it == server->mSessions.end()) {
ALOGE("Cannot add thread, no record of session with ID %s",
- sessionId.toString().c_str());
+ base::HexString(sessionId.data(), sessionId.size()).c_str());
return;
}
session = it->second;
@@ -432,16 +457,17 @@
}
void RpcServer::onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) {
- auto id = session->mId;
- LOG_ALWAYS_FATAL_IF(id == std::nullopt, "Server sessions must be initialized with ID");
- LOG_RPC_DETAIL("Dropping session with address %s", id->toString().c_str());
+ const std::vector<uint8_t>& id = session->mId;
+ LOG_ALWAYS_FATAL_IF(id.empty(), "Server sessions must be initialized with ID");
+ LOG_RPC_DETAIL("Dropping session with address %s",
+ base::HexString(id.data(), id.size()).c_str());
std::lock_guard<std::mutex> _l(mLock);
- auto it = mSessions.find(*id);
+ auto it = mSessions.find(id);
LOG_ALWAYS_FATAL_IF(it == mSessions.end(), "Bad state, unknown session id %s",
- id->toString().c_str());
+ base::HexString(id.data(), id.size()).c_str());
LOG_ALWAYS_FATAL_IF(it->second != session, "Bad state, session has id mismatch %s",
- id->toString().c_str());
+ base::HexString(id.data(), id.size()).c_str());
(void)mSessions.erase(it);
}