From 9cdac1cb60aa9590b36623243f5462d604307667 Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Sun, 25 Oct 2026 12:54:46 +0300
Subject: [PATCH] splice() pipes closed with fdclose(), the loop forgetting
 them first

sockmap waits on its splice() pipes as on its sockets, and on an event
loop a pipe waited on is registered there like a socket. They were
closed with close(), past the socket functions, so the loop kept the
registration of a closed descriptor, which epoll and kqueue drop on the
close: a socket given the same number later was taken for it, never
registered, and its fiber waited on it forever. fdclose() tells the
loop first.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/common.c     | 10 ++++++++++
 src/mainclient.c |  8 ++++----
 src/proxy.h      |  3 +++
 src/sockmap.c    |  8 ++++----
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/src/common.c b/src/common.c
index 5016d14..03d5435 100644
--- a/src/common.c
+++ b/src/common.c
@@ -492,6 +492,16 @@ struct sockfuncs so = {
 	def_closesocket
 };
 
+#ifndef _WIN32
+/* close() of a descriptor a fiber may have waited on, a pipe of splice():
+   its loop forgets it first, or a socket given the same number later would
+   be taken for it, and never registered. */
+int fdclose(int fd){
+	if(fiberclosefunc) fiberclosefunc(fd);
+	return close(fd);
+}
+#endif
+
 /* Whether s, found readable, is: data or its end there. A fiber's wait
    may answer with what a socket was reported ready for, until an
    operation finds it not to be: whatever takes readability for an end,
diff --git a/src/mainclient.c b/src/mainclient.c
index 47ea0f5..9bf0a0d 100644
--- a/src/mainclient.c
+++ b/src/mainclient.c
@@ -393,10 +393,10 @@ void releaseparam(struct clientparam * param) {
 	param->clibuf = param->clibufdata;
 	param->srvbuf = param->srvbufdata;
 #ifdef WITHSPLICE
-	if(param->pipecli[0] >= 0) close(param->pipecli[0]);
-	if(param->pipecli[1] >= 0) close(param->pipecli[1]);
-	if(param->pipesrv[0] >= 0) close(param->pipesrv[0]);
-	if(param->pipesrv[1] >= 0) close(param->pipesrv[1]);
+	if(param->pipecli[0] >= 0) fdclose(param->pipecli[0]);
+	if(param->pipecli[1] >= 0) fdclose(param->pipecli[1]);
+	if(param->pipesrv[0] >= 0) fdclose(param->pipesrv[0]);
+	if(param->pipesrv[1] >= 0) fdclose(param->pipesrv[1]);
 	param->pipecli[0] = param->pipecli[1] = param->pipesrv[0] = param->pipesrv[1] = -1;
 #endif
 	/* Not shut down on Windows: there shutting down receiving resets the
diff --git a/src/proxy.h b/src/proxy.h
index 998e7f1..326d451 100644
--- a/src/proxy.h
+++ b/src/proxy.h
@@ -337,6 +337,9 @@ extern int (*fiberpollfunc)(struct pollfd *fds, unsigned nfds, int timeout);
 extern void (*fiberblockfunc)(SOCKET s, short events);
 extern void (*fiberclosefunc)(SOCKET s);
 int sockreadable(SOCKET s);
+#ifndef _WIN32
+int fdclose(int fd);
+#endif
 void nonblock(SOCKET sock);
 int sysresolves(int mode);
 int acceptagain(void);
diff --git a/src/sockmap.c b/src/sockmap.c
index c2b547f..e625ef3 100644
--- a/src/sockmap.c
+++ b/src/sockmap.c
@@ -1009,13 +1009,13 @@ CLEANRET:
  /* empty pipes stay with the connection for its next mapping; one still
     holding data, left by an error or a timeout, cannot be used again */
  if(inclientpipe && pipecli[0] >= 0){
-	close(pipecli[0]);
-	close(pipecli[1]);
+	fdclose(pipecli[0]);
+	fdclose(pipecli[1]);
 	pipecli[0] = pipecli[1] = -1;
  }
  if(inserverpipe && pipesrv[0] >= 0){
-	close(pipesrv[0]);
-	close(pipesrv[1]);
+	fdclose(pipesrv[0]);
+	fdclose(pipesrv[1]);
 	pipesrv[0] = pipesrv[1] = -1;
  }
 #endif