libbinder: Return status_t from RpcTransport::peek()

Result<> pulls in over 100k of extra libc++ code on Trusty
so this CL replaces it with status_t as the result type of
RpcTransport::peek().

Bug: 224644083
Test: atest binderRpcTest
Change-Id: Idde111245794dc4afd421f3a723feacc8c3a346e

5 files changed, 45 insertions, 29 deletions

diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 2e7084e12e..173e30a2e7 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -660,8 +660,14 @@ status_t RpcState::getAndExecuteCommand(const sp<RpcSession::RpcConnection>& con
 status_t RpcState::drainCommands(const sp<RpcSession::RpcConnection>& connection,
                                  const sp<RpcSession>& session, CommandType type) {
     uint8_t buf;
-    while (connection->rpcTransport->peek(&buf, sizeof(buf)).value_or(0) > 0) {
-        status_t status = getAndExecuteCommand(connection, session, type);
+    while (true) {
+        size_t num_bytes;
+        status_t status = connection->rpcTransport->peek(&buf, sizeof(buf), &num_bytes);
+        if (status == WOULD_BLOCK) break;
+        if (status != OK) return status;
+        if (!num_bytes) break;
+
+        status = getAndExecuteCommand(connection, session, type);
         if (status != OK) return status;
     }
     return OK;
diff --git a/libs/binder/RpcTransportRaw.cpp b/libs/binder/RpcTransportRaw.cpp
index 636e5d06e5..7cfc78082e 100644
--- a/libs/binder/RpcTransportRaw.cpp
+++ b/libs/binder/RpcTransportRaw.cpp
@@ -24,9 +24,6 @@
 #include "FdTrigger.h"
 #include "RpcState.h"
 
-using android::base::ErrnoError;
-using android::base::Result;
-
 namespace android {
 
 namespace {
@@ -35,12 +32,20 @@ namespace {
 class RpcTransportRaw : public RpcTransport {
 public:
     explicit RpcTransportRaw(android::base::unique_fd socket) : mSocket(std::move(socket)) {}
-    Result<size_t> peek(void *buf, size_t size) override {
+    status_t peek(void* buf, size_t size, size_t* out_size) override {
         ssize_t ret = TEMP_FAILURE_RETRY(::recv(mSocket.get(), buf, size, MSG_PEEK));
         if (ret < 0) {
-            return ErrnoError() << "recv(MSG_PEEK)";
+            int savedErrno = errno;
+            if (savedErrno == EAGAIN || savedErrno == EWOULDBLOCK) {
+                return WOULD_BLOCK;
+            }
+
+            LOG_RPC_DETAIL("RpcTransport peek(): %s", strerror(savedErrno));
+            return -savedErrno;
         }
-        return ret;
+
+        *out_size = static_cast<size_t>(ret);
+        return OK;
     }
 
     template <typename SendOrReceive>
diff --git a/libs/binder/RpcTransportTls.cpp b/libs/binder/RpcTransportTls.cpp
index 3936204bdf..bc68c379ce 100644
--- a/libs/binder/RpcTransportTls.cpp
+++ b/libs/binder/RpcTransportTls.cpp
@@ -37,10 +37,6 @@
 #define LOG_TLS_DETAIL(...) ALOGV(__VA_ARGS__) // for type checking
 #endif
 
-using android::base::ErrnoError;
-using android::base::Error;
-using android::base::Result;
-
 namespace android {
 namespace {
 
@@ -165,17 +161,8 @@ public:
         return ret;
     }
 
-    // |sslError| should be from Ssl::getError().
-    // If |sslError| is WANT_READ / WANT_WRITE, poll for POLLIN / POLLOUT respectively. Otherwise
-    // return error. Also return error if |fdTrigger| is triggered before or during poll().
-    status_t pollForSslError(android::base::borrowed_fd fd, int sslError, FdTrigger* fdTrigger,
-                             const char* fnString, int additionalEvent,
-                             const std::function<status_t()>& altPoll) {
+    status_t toStatus(int sslError, const char* fnString) {
         switch (sslError) {
-            case SSL_ERROR_WANT_READ:
-                return handlePoll(POLLIN | additionalEvent, fd, fdTrigger, fnString, altPoll);
-            case SSL_ERROR_WANT_WRITE:
-                return handlePoll(POLLOUT | additionalEvent, fd, fdTrigger, fnString, altPoll);
             case SSL_ERROR_SYSCALL: {
                 auto queue = toString();
                 LOG_TLS_DETAIL("%s(): %s. Treating as DEAD_OBJECT. Error queue: %s", fnString,
@@ -191,6 +178,22 @@ public:
         }
     }
 
+    // |sslError| should be from Ssl::getError().
+    // If |sslError| is WANT_READ / WANT_WRITE, poll for POLLIN / POLLOUT respectively. Otherwise
+    // return error. Also return error if |fdTrigger| is triggered before or during poll().
+    status_t pollForSslError(android::base::borrowed_fd fd, int sslError, FdTrigger* fdTrigger,
+                             const char* fnString, int additionalEvent,
+                             const std::function<status_t()>& altPoll) {
+        switch (sslError) {
+            case SSL_ERROR_WANT_READ:
+                return handlePoll(POLLIN | additionalEvent, fd, fdTrigger, fnString, altPoll);
+            case SSL_ERROR_WANT_WRITE:
+                return handlePoll(POLLOUT | additionalEvent, fd, fdTrigger, fnString, altPoll);
+            default:
+                return toStatus(sslError, fnString);
+        }
+    }
+
 private:
     bool mHandled = false;
 
@@ -274,7 +277,7 @@ class RpcTransportTls : public RpcTransport {
 public:
     RpcTransportTls(android::base::unique_fd socket, Ssl ssl)
           : mSocket(std::move(socket)), mSsl(std::move(ssl)) {}
-    Result<size_t> peek(void* buf, size_t size) override;
+    status_t peek(void* buf, size_t size, size_t* out_size) override;
     status_t interruptableWriteFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
                                      const std::function<status_t()>& altPoll) override;
     status_t interruptableReadFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
@@ -286,7 +289,7 @@ private:
 };
 
 // Error code is errno.
-Result<size_t> RpcTransportTls::peek(void* buf, size_t size) {
+status_t RpcTransportTls::peek(void* buf, size_t size, size_t* out_size) {
     size_t todo = std::min<size_t>(size, std::numeric_limits<int>::max());
     auto [ret, errorQueue] = mSsl.call(SSL_peek, buf, static_cast<int>(todo));
     if (ret < 0) {
@@ -294,13 +297,15 @@ Result<size_t> RpcTransportTls::peek(void* buf, size_t size) {
         if (err == SSL_ERROR_WANT_WRITE || err == SSL_ERROR_WANT_READ) {
             // Seen EAGAIN / EWOULDBLOCK on recv(2) / send(2).
             // Like RpcTransportRaw::peek(), don't handle it here.
-            return Error(EWOULDBLOCK) << "SSL_peek(): " << errorQueue.toString();
+            errorQueue.clear();
+            return WOULD_BLOCK;
         }
-        return Error() << "SSL_peek(): " << errorQueue.toString();
+        return errorQueue.toStatus(err, "SSL_peek");
     }
     errorQueue.clear();
     LOG_TLS_DETAIL("TLS: Peeked %d bytes!", ret);
-    return ret;
+    *out_size = static_cast<size_t>(ret);
+    return OK;
 }
 
 status_t RpcTransportTls::interruptableWriteFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
diff --git a/libs/binder/include/binder/RpcTransport.h b/libs/binder/include/binder/RpcTransport.h
index ade2d94609..751c4f905d 100644
--- a/libs/binder/include/binder/RpcTransport.h
+++ b/libs/binder/include/binder/RpcTransport.h
@@ -22,7 +22,6 @@
 #include <memory>
 #include <string>
 
-#include <android-base/result.h>
 #include <android-base/unique_fd.h>
 #include <utils/Errors.h>
 
@@ -41,7 +40,7 @@ public:
     virtual ~RpcTransport() = default;
 
     // replacement of ::recv(MSG_PEEK). Error code may not be set if TLS is enabled.
-    [[nodiscard]] virtual android::base::Result<size_t> peek(void *buf, size_t size) = 0;
+    [[nodiscard]] virtual status_t peek(void *buf, size_t size, size_t *out_size) = 0;
 
     /**
      * Read (or write), but allow to be interrupted by a trigger.
diff --git a/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h b/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
index 094addd690..50d12c408f 100644
--- a/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
+++ b/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
@@ -18,6 +18,7 @@
 
 #include <memory>
 #include <mutex>
+#include <vector>
 
 #include <binder/RpcAuth.h>
 #include <binder/RpcCertificateFormat.h>