Set LINELEN to 8k for clients that support long messages

This matches the value already negotiated for cap multiline. I think we could go up to 16k without difficulty, but 8k is probably sufficient. This also tells gen_tcp to use an 8k buffer; the default buffer size is about 1.5k (one TCP packet, maybe?) and cuts off longer commands, with tragic results.
progval · Feb 12, 2024 · 7ece9ae · 7ece9ae
1 parent 80dc1da
commit 7ece9ae
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diff --git a/lib/irc/handler.ex b/lib/irc/handler.ex
@@ -607,6 +607,8 @@ defmodule M51.IrcConn.Handler do
       "CHANMODES=b,,,i",
       "CHANTYPES=#!",
       "CHATHISTORY=100",
+      # Matrix limit is 64k for the whole event, so this is fairly conservative.
+      "LINELEN=8192",
       "MAXTARGETS=1",
       # https://github.com/ircv3/ircv3-specifications/pull/510
       "MSGREFTYPES=msgid",

diff --git a/lib/irc_server.ex b/lib/irc_server.ex
@@ -40,7 +40,7 @@ defmodule M51.IrcServer do
   end
 
   defp accept(port, retries_left \\ 10) do
-    case :gen_tcp.listen(port, [:binary, :inet6, packet: :line, active: false, reuseaddr: true]) do
+    case :gen_tcp.listen(port, [:binary, :inet6, packet: :line, active: false, reuseaddr: true, buffer: 8192]) do
       {:ok, server_sock} ->
         Logger.info("Listening on port #{port}")
         loop_accept(server_sock)

diff --git a/test/irc/handler_test.exs b/test/irc/handler_test.exs
@@ -20,7 +20,7 @@ defmodule M51.IrcConn.HandlerTest do
 
   @cap_ls_302 ":server. CAP * LS :account-tag batch draft/account-registration=before-connect draft/channel-rename draft/chathistory draft/message-redaction draft/multiline=max-bytes=8192 draft/no-implicit-names draft/sasl-ir echo-message extended-join labeled-response message-tags sasl=PLAIN server-time soju.im/account-required standard-replies userhost-in-names\r\n"
   @cap_ls ":server. CAP * LS :account-tag batch draft/account-registration draft/channel-rename draft/chathistory draft/message-redaction draft/multiline draft/no-implicit-names draft/sasl-ir echo-message extended-join labeled-response message-tags sasl server-time soju.im/account-required standard-replies userhost-in-names\r\n"
-  @isupport "CASEMAPPING=rfc3454 CLIENTTAGDENY=*,-draft/react,-draft/reply CHANLIMIT= CHANMODES=b,,,i CHANTYPES=#! CHATHISTORY=100 MAXTARGETS=1 MSGREFTYPES=msgid PREFIX= TARGMAX=JOIN:1,PART:1 UTF8ONLY :are supported by this server\r\n"
+  @isupport "CASEMAPPING=rfc3454 CLIENTTAGDENY=*,-draft/react,-draft/reply CHANLIMIT= CHANMODES=b,,,i CHANTYPES=#! CHATHISTORY=100 LINELEN=8192 MAXTARGETS=1 MSGREFTYPES=msgid PREFIX= TARGMAX=JOIN:1,PART:1 UTF8ONLY :are supported by this server\r\n"
 
   setup do
     start_supervised!({MockMatrixClient, {self()}})