From 6fd8c49d50803bbccfcc11b195f9e334a6e835e9 Mon Sep 17 00:00:00 2001
From: Pedro Tanaka <pedro.tanaka@shopify.com>
Date: Tue, 14 Jan 2025 12:46:59 +0100
Subject: [PATCH] Prevent ENOBUFS errors by skipping UDP send buffer size
 configuration (#392)

The previous implementation attempted to set the UDP socket's send buffer
size, which could lead to ENOBUFS errors in some environments. This change:
- Overrides setup_socket in UDPConnection to skip buffer size configuration
- Improves socket creation by using the correct address family
- Updates error message to be more accurate ("Failed to setup socket")

This prevents potential buffer-related errors while maintaining the original
functionality for other connection types.
---
 CHANGELOG.md                                 |  4 ++++
 Gemfile                                      |  5 +++++
 lib/statsd/instrument/connection_behavior.rb |  2 +-
 lib/statsd/instrument/udp_connection.rb      |  9 +++++++--
 lib/statsd/instrument/version.rb             |  2 +-
 test/udp_sink_test.rb                        | 14 --------------
 6 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0c6c0c3d..dd6fb003 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ section below.
 
 ## Unreleased changes
 
+## Version 3.9.9
+
+- [#392](https://github.com/Shopify/statsd-instrument/pull/392) - Prevent ENOBUFS errors when using UDP, by skipping setting socket buffer size.
+
 ## Version 3.9.8
 
 - [#390](https://github.com/Shopify/statsd-instrument/pull/391) - Fixing bug in Environment when using UDS. The max packet size option was not being passed to the 
diff --git a/Gemfile b/Gemfile
index f6ef0d3c..0d053075 100644
--- a/Gemfile
+++ b/Gemfile
@@ -19,4 +19,9 @@ platform :mri do
   if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("3.2")
     gem "vernier", require: false
   end
+
+  # From Ruby >= 3.5, logger is not part of the stdlib anymore
+  if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("3.5")
+    gem "logger"
+  end
 end
diff --git a/lib/statsd/instrument/connection_behavior.rb b/lib/statsd/instrument/connection_behavior.rb
index 4a651157..0e8e7fcf 100644
--- a/lib/statsd/instrument/connection_behavior.rb
+++ b/lib/statsd/instrument/connection_behavior.rb
@@ -42,7 +42,7 @@ def setup_socket(original_socket)
         original_socket
       rescue IOError => e
         StatsD.logger.debug do
-          "[#{self.class.name}] Failed to create socket: #{e.class}: #{e.message}"
+          "[#{self.class.name}] Failed to setup socket: #{e.class}: #{e.message}"
         end
         nil
       end
diff --git a/lib/statsd/instrument/udp_connection.rb b/lib/statsd/instrument/udp_connection.rb
index a291319c..b7f9ff5f 100644
--- a/lib/statsd/instrument/udp_connection.rb
+++ b/lib/statsd/instrument/udp_connection.rb
@@ -25,11 +25,16 @@ def type
 
       private
 
+      def setup_socket(original_socket)
+        original_socket
+      end
+
       def socket
         @socket ||= begin
-          udp_socket = UDPSocket.new
+          family = Addrinfo.udp(host, port).afamily
+          udp_socket = UDPSocket.new(family)
           setup_socket(udp_socket)&.tap do |s|
-            s.connect(@host, @port)
+            s.connect(host, port)
           end
         end
       end
diff --git a/lib/statsd/instrument/version.rb b/lib/statsd/instrument/version.rb
index fb5ec9b5..793dca58 100644
--- a/lib/statsd/instrument/version.rb
+++ b/lib/statsd/instrument/version.rb
@@ -2,6 +2,6 @@
 
 module StatsD
   module Instrument
-    VERSION = "3.9.8"
+    VERSION = "3.9.9"
   end
 end
diff --git a/test/udp_sink_test.rb b/test/udp_sink_test.rb
index 7fe9c2da..ef3c6059 100644
--- a/test/udp_sink_test.rb
+++ b/test/udp_sink_test.rb
@@ -151,25 +151,11 @@ def test_socket_error_should_invalidate_socket
       seq = sequence("connect_fail_connect_succeed")
 
       # First attempt
-      socket.expects(:setsockopt)
-        .with(Socket::SOL_SOCKET, Socket::SO_SNDBUF, StatsD::Instrument::UdpConnection::DEFAULT_MAX_PACKET_SIZE)
-        .in_sequence(seq)
-      socket.expects(:getsockopt)
-        .with(Socket::SOL_SOCKET, Socket::SO_SNDBUF)
-        .returns(mock(int: StatsD::Instrument::UdpConnection::DEFAULT_MAX_PACKET_SIZE))
-        .in_sequence(seq)
       socket.expects(:connect).with("localhost", 8125).in_sequence(seq)
       socket.expects(:send).raises(Errno::EDESTADDRREQ).in_sequence(seq)
       socket.expects(:close).in_sequence(seq)
 
       # Second attempt after error
-      socket.expects(:setsockopt)
-        .with(Socket::SOL_SOCKET, Socket::SO_SNDBUF, StatsD::Instrument::UdpConnection::DEFAULT_MAX_PACKET_SIZE)
-        .in_sequence(seq)
-      socket.expects(:getsockopt)
-        .with(Socket::SOL_SOCKET, Socket::SO_SNDBUF)
-        .returns(mock(int: StatsD::Instrument::UdpConnection::DEFAULT_MAX_PACKET_SIZE))
-        .in_sequence(seq)
       socket.expects(:connect).with("localhost", 8125).in_sequence(seq)
       socket.expects(:send).twice.returns(1).in_sequence(seq)
       socket.expects(:close).in_sequence(seq)