[PATCH] drop MSG_EOR for AF_UNIX + SOCK_SEQPACKET

[Eric Wong <e@80x24.org>]

Using MSG_EOR with these local sockets is not necessary, and
appears to trigger a truncation bug on OpenBSD 7.3.

Link: https://marc.info/?i=20230826020759.M335788@dcvr
---
 lib/dtas/player/client_handler.rb | 2 +-
 lib/dtas/unix_accepted.rb         | 4 ++--
 lib/dtas/unix_client.rb           | 2 +-
 test/test_unixserver.rb           | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/dtas/player/client_handler.rb b/lib/dtas/player/client_handler.rb
index 2914fe7..3c5fe5d 100644
--- a/lib/dtas/player/client_handler.rb
+++ b/lib/dtas/player/client_handler.rb
@@ -564,7 +564,7 @@ def state_file_dump_async(io, sf)
         rescue => e
           res = "ERR dumping to #{xs(sf.path)} #{e.message}"
         end
-        io.to_io.send(res, Socket::MSG_EOR)
+        io.to_io.send(res, 0)
       ensure
         exit!(0)
       end
diff --git a/lib/dtas/unix_accepted.rb b/lib/dtas/unix_accepted.rb
index a84eade..63d3ce0 100644
--- a/lib/dtas/unix_accepted.rb
+++ b/lib/dtas/unix_accepted.rb
@@ -17,7 +17,7 @@ def initialize(sock)
   # returns :wait_readable on success
   def emit(msg)
     if @sbuf.empty?
-      case rv = @to_io.sendmsg_nonblock(msg, Socket::MSG_EOR, exception: false)
+      case rv = @to_io.sendmsg_nonblock(msg, 0, exception: false)
       when :wait_writable
         @sbuf << msg
         rv
@@ -34,7 +34,7 @@ def emit(msg)
 
   # flushes pending data if it got buffered
   def writable_iter
-    case @to_io.sendmsg_nonblock(@sbuf[0], Socket::MSG_EOR, exception: false)
+    case @to_io.sendmsg_nonblock(@sbuf[0], 0, exception: false)
     when :wait_writable then return :wait_writable
     else
       @sbuf.shift
diff --git a/lib/dtas/unix_client.rb b/lib/dtas/unix_client.rb
index 71f833c..8c73b7d 100644
--- a/lib/dtas/unix_client.rb
+++ b/lib/dtas/unix_client.rb
@@ -24,7 +24,7 @@ def initialize(path = self.class.default_path)
 
   def req_start(args)
     args = xs(args) if Array === args
-    @to_io.send(args, Socket::MSG_EOR)
+    @to_io.send(args, 0)
   end
 
   def req_ok(args, timeout = nil)
diff --git a/test/test_unixserver.rb b/test/test_unixserver.rb
index 7e99b9e..c91354d 100644
--- a/test/test_unixserver.rb
+++ b/test/test_unixserver.rb
@@ -41,7 +41,7 @@ def test_server_loop
     @srv.run_once # nothing
     msgs = []
     clients = []
-    client.send("HELLO", Socket::MSG_EOR)
+    client.send("HELLO", 0)
     @srv.run_once do |c, msg|
       clients << c
       msgs << msg