From db833d36e9e318252e01f9a7d4608702634e673c Mon Sep 17 00:00:00 2001
From: John Knox <jknox@fb.com>
Date: Wed, 31 Oct 2018 11:13:14 -0700
Subject: [PATCH] Add max rsocket payload size

Summary:
We're seeing some crashes when attempting to send payloads larger than are supported by rsocket.
Instead of crashing, skip the message, but log it so we can see what it's containing.

This is where the failure occurs: https://github.com/rsocket/rsocket-cpp/blob/master/rsocket/framing/FramedDuplexConnection.cpp#L64

Reviewed By: passy

Differential Revision: D12857616

fbshipit-source-id: 2b02d7f5dd6499ba81783d3f8aefcbb64d9d408a
---
 xplat/Flipper/FlipperConnectionManagerImpl.cpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/xplat/Flipper/FlipperConnectionManagerImpl.cpp b/xplat/Flipper/FlipperConnectionManagerImpl.cpp
index a4b29fedc..30be9a64d 100644
--- a/xplat/Flipper/FlipperConnectionManagerImpl.cpp
+++ b/xplat/Flipper/FlipperConnectionManagerImpl.cpp
@@ -29,6 +29,8 @@ static constexpr int connectionKeepaliveSeconds = 10;
 static constexpr int securePort = 8088;
 static constexpr int insecurePort = 8089;
 
+static constexpr int maxPayloadSize = 0xFFFFFF;
+
 namespace facebook {
 namespace flipper {
 
@@ -216,9 +218,22 @@ void FlipperConnectionManagerImpl::setCallbacks(Callbacks* callbacks) {
 
 void FlipperConnectionManagerImpl::sendMessage(const folly::dynamic& message) {
   flipperEventBase_->add([this, message]() {
+    std::string json = folly::toJson(message);
+    rsocket::Payload payload = rsocket::Payload(json);
+    auto payloadLength = payload.data->computeChainDataLength();
+
+    DCHECK_LE(payloadLength, maxPayloadSize);
+    if (payloadLength > maxPayloadSize) {
+      auto logMessage =
+          std::string(
+              "Error: Skipping sending message larger than max rsocket payload: ") +
+          json;
+      log(logMessage);
+      return;
+    }
     if (client_) {
       client_->getRequester()
-          ->fireAndForget(rsocket::Payload(folly::toJson(message)))
+          ->fireAndForget(std::move(payload))
           ->subscribe([]() {});
     }
   });