Applying the "Connection reset by peer"

[Max Bowsher]

bart.coninckx at watco.be wrote:
> Hi all,
>
> we're suffering heavily from the "connection reset by peer" problem
> when running Rsync on WinNT.
> Great was our relief when seeing Randy's message in
> http://www.mail-archive.com/rsync@lists.samba.org/msg01918.html
>
> I immediately installed the full Cygwin to recompile Rsync, but since
> I'm far from a C guru, I'm a bit puzzled with the last 2 lines in
> Randy's patch:
>
> cleanup.c:_exit_cleanup() just before exit(code)
> socket.c:start_accept_loop() just before _exit(ret)
>
>
> should I simply put "_exit_cleanup()" before "exit(code)" in
> cleanup.c with nothing in between the "()" ? (same for socket.c?)

Not quite - put "close_all();" there. But the socket.c code seems to have
changed since then. The temporary variable ret seems to have been tidied away.

I have attached a patch against rsync-2.5.5:

cd rsync-2.5.5    # wherever you unpacked the source tarball
patch -i crbp.patch

It adds the temporary variable I mention above, and implements the instructions
given in the email link you mention above.

Please note, that I have simply made the instructions easier to follow, I have
not checked them for correctness. (Although I don't see anything obviously
wrong.)

> I disregard these two lines and compiled the EXE again and it seems
> to be working, haven't tested it thoroughly though...

Without adding those 2 calls to close_all(), there should be no change.

Max.
-------------- next part --------------
--- socket.c.orig	2002-08-22 18:43:18.000000000 +0100
+++ socket.c	2002-08-22 18:48:11.000000000 +0100
@@ -427,11 +427,14 @@
 #endif
 
 		if ((pid = fork()) == 0) {
+			int ret;
 			close(s);
 			/* open log file in child before possibly giving
 			   up privileges  */
 			log_open();
-			_exit(fn(fd));
+			ret = fn(fd);
+			close_all();
+			_exit(ret);
 		} else if (pid < 0) {
 			rprintf(FERROR,
 				RSYNC_NAME
--- cleanup.c.orig	2002-08-22 18:43:13.000000000 +0100
+++ cleanup.c	2002-08-22 18:45:15.000000000 +0100
@@ -35,6 +35,32 @@
 
 pid_t cleanup_child_pid = -1;
 
+void close_all()
+/* rmo: 5/31/01
+   Close all open sockets and files, allowing a (somewhat) graceful
+   shutdown() of socket connections.  This eliminates the abortive
+   TCP RST sent by a Winsock-based system when the close() occurs.
+   
+   See http://www.mail-archive.com/rsync@lists.samba.org/msg01918.html
+*/
+{
+    int max_fd;
+    int fd;
+    int ret;
+    struct stat st;
+
+    max_fd = sysconf(_SC_OPEN_MAX) - 1;
+    for (fd = max_fd; fd >= 0; fd--) {
+      ret = fstat(fd,&st);
+      if (fstat(fd,&st) == 0){                /* Open fd */
+            if (is_a_socket(fd)) {
+              ret = shutdown(fd,2);           /* Somewhat graceful */
+            }
+            ret = close(fd);
+      }
+    }
+}
+
 /*
  * Code is one of the RERR_* codes from errcode.h.
  */
@@ -90,6 +116,7 @@
 		rprintf(FINFO,"_exit_cleanup(code=%d, file=%s, line=%d): about to call exit(%d)\n", 
 			ocode, file, line, code);
 
+	close_all();
 	exit(code);
 }