rsync - Apr 2002 - Patch to avoid 'Connection reset by peer' error for rsync on cygwin

The problem is caused because rsync does not close its sockets, and WinSock is a
quite strict on this. The solution is to shutdown and close the fd.
This is a 5-minute hack I've done to fix the obvious occurrences of the
problem.
It might be better to extend rsyncs cleanup functions for this, but here it is
anyway to alert people to the problem and its fix.

Max.

BEGIN PATCH
diff -mru rsync-2.5.5/clientserver.c rsync-2.5.5-tweaked/clientserver.c
--- rsync-2.5.5/clientserver.c Wed Mar 27 01:03:13 2002
+++ rsync-2.5.5-tweaked/clientserver.c Wed Apr  3 11:01:57 2002
@@ -486,39 +486,44 @@
  }

  if (!read_line(fd, line, sizeof(line)-1)) {
-  return -1;
+  goto exitwithnomodule;
  }

  if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
   io_printf(fd,"@ERROR: protocol startup error\n");
-  return -1;
+  goto exitwithnomodule;
  }

  while (i == -1) {
   line[0] = 0;
   if (!read_line(fd, line, sizeof(line)-1)) {
-   return -1;
+   goto exitwithnomodule;
   }

   if (!*line || strcmp(line,"#list")==0) {
    send_listing(fd);
-   return -1;
+   goto exitwithnomodule;
   }

   if (*line == '#') {
    /* it's some sort of command that I don't understand */
    io_printf(fd,"@ERROR: Unknown command '%s'\n", line);
-   return -1;
+   goto exitwithnomodule;
   }

   i = lp_number(line);
   if (i == -1) {
    io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
-   return -1;
+   goto exitwithnomodule;
   }
  }

  return rsync_module(fd, i);
+
+exitwithnomodule:
+ shutdown(fd,SHUT_WR);
+ close(fd);
+ return -1;
 }


END PATCH

Does anybody know if this might cause problems on non-Windows machines?
Would "shutdown" need to be checked in configure, or is it implemented
on
all Unix variants?  I don't recall ever seeing a need for it on Unix.

- Dave

On Wed, Apr 03, 2002 at 11:39:57AM +0100, Max Bowsher
wrote:
> The problem is caused because rsync does not close its sockets, and WinSock
is a
> quite strict on this. The solution is to shutdown and close the fd.
> This is a 5-minute hack I've done to fix the obvious occurrences of the
problem.
> It might be better to extend rsyncs cleanup functions for this, but here it
is
> anyway to alert people to the problem and its fix.
> 
> Max.
> 
> BEGIN PATCH
> diff -mru rsync-2.5.5/clientserver.c rsync-2.5.5-tweaked/clientserver.c
> --- rsync-2.5.5/clientserver.c Wed Mar 27 01:03:13 2002
> +++ rsync-2.5.5-tweaked/clientserver.c Wed Apr  3 11:01:57 2002
> @@ -486,39 +486,44 @@
>   }
> 
>   if (!read_line(fd, line, sizeof(line)-1)) {
> -  return -1;
> +  goto exitwithnomodule;
>   }
> 
>   if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
>    io_printf(fd,"@ERROR: protocol startup error\n");
> -  return -1;
> +  goto exitwithnomodule;
>   }
> 
>   while (i == -1) {
>    line[0] = 0;
>    if (!read_line(fd, line, sizeof(line)-1)) {
> -   return -1;
> +   goto exitwithnomodule;
>    }
> 
>    if (!*line || strcmp(line,"#list")==0) {
>     send_listing(fd);
> -   return -1;
> +   goto exitwithnomodule;
>    }
> 
>    if (*line == '#') {
>     /* it's some sort of command that I don't understand */
>     io_printf(fd,"@ERROR: Unknown command '%s'\n", line);
> -   return -1;
> +   goto exitwithnomodule;
>    }
> 
>    i = lp_number(line);
>    if (i == -1) {
>     io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
> -   return -1;
> +   goto exitwithnomodule;
>    }
>   }
> 
>   return rsync_module(fd, i);
> +
> +exitwithnomodule:
> + shutdown(fd,SHUT_WR);
> + close(fd);
> + return -1;
>  }
> 
> 
> END PATCH
> 
> 
> 
> 
> -- 
> To unsubscribe or change options:
http://lists.samba.org/mailman/listinfo/rsync
> Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html

Max Bowsher [maxb@ukf.net] writes:
> I though that shutdown acts as below:
(no data loss)
> SUSv2 is annoyingly somewhat vague on the specifics.
So are the FreeBSD/Linux man pages.  They don't specifically indicate
truncation or flushing of data, although I don't recall ever thinking
of shutdown() as truncating.

To be, what Microsoft got wrong in WinSock is _requiring_ shutdown()
to reliably close a socket while ensuring all final data gets
delivered.  It certainly caught me by surprise (and annoyance) at one
point.  I rarely ever used it in a Unix environment, but I do think it
should be safe.

-- David

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What is the status of this patch? (Ideally I'd like it to make it in to
2.5.6,
so I can stop using a modified version). I have successfully used rsync with the
patch on Linux, and have done a test where a client does connect(), then
sleep(), whilst the server does write(), shutdown(,SHUT_WR),close(), before the
client does read(), and this completes successfully.

If there is anything else I should do to help it along, please let me know.

Max.

What is the status of my patch?

If the answer is 'In a ToDo list', then I will be quite happy, but if
there are
any objections to it, I would like to resolve them.

Thankyou.

Max.