Fw: Windows 2000 breaks the samba client

[Jeremy Allison]

Ok I've fixed it. Turns out it was a weird little bug in Win2k...
well, maybe :-).

It seems that the RAP functions in Win2k can't cope
with a max buffer reply size of 64K (0xFFFF) - it returns "No server
memory" instead of the requested reply. So I fixed the problem
by dropping the buffer size reply from 0xFFFF to 0xFFE0 in
the Samba client code - an empirical number determined by trial
and error (as are so many things in Microsoft's protocol :-).

The old buffer value of 0xFFFF works correctly with all previous
versions of Windows (and should be the correct value to use,
as you really do want to have the maximum permitted share
list size returned), but Win2K seems to be "different". Hmmmm :-).

I have attached the patch for 2.0.6 (it should apply
cleanly to 2.0.6, and with a few minor offsets to older
and newer versions of Samba as well) and also have checked
the changes into the HEAD and 2.0.7 trees.

I also took the opportunity to improve the error reporting
of share enumeration failures in the client code (as we
were just silently ignoring them).

So, no malevolent Microsoft plots :-), just a plain old
bug (sorry to dissapoint "X-Files" fans :-) :-). Whether
this is a bug in Samba or in Win2k I'll leave the reader
to decide...... (fade out with Twilight Zone music :-).

What *is* clear is that Microsoft didn't regression test
with the Samba *client* code (although I know they did
with the server code).

Here's the patch - enjoy :-).

Cheers,

	Jeremy Allison,
	Samba Team.

PS. Thanks to Antoine BUSCH from Corel Corp. for providing
a very helpful hint. I *love* Open Source :-).

PPS. Also thanks to VA Linux Systems (my employer) for allowing
me to drop everything, run out and buy Win2K server, put it on
a spare machine, and mess with it for a while :-).

PPPS. Dwight, if you want to publish this in LinuxToday now,
to let people know the facts ("Just the Facts Ma'am" :-) be my guest.

---------------------cut here-----------------------------
--- libsmb/clientgen.c.orig	Fri Feb 25 10:33:23 2000
+++ libsmb/clientgen.c	Fri Feb 25 10:33:31 2000
@@ -600,7 +600,7 @@
 /****************************************************************************
 call a NetShareEnum - try and browse available connections on a host
 ****************************************************************************/
-BOOL cli_RNetShareEnum(struct cli_state *cli, void (*fn)(const char *, uint32, const char *))
+int cli_RNetShareEnum(struct cli_state *cli, void (*fn)(const char *, uint32, const char *))
 {
   char *rparam = NULL;
   char *rdata = NULL;
@@ -618,12 +618,16 @@
   pstrcpy(p,"B13BWz");
   p = skip_string(p,1);
   SSVAL(p,0,1);
-  SSVAL(p,2,0xFFFF);
+  /*
+   * Win2k needs a *smaller* buffer than 0xFFFF here -
+   * it returns "out of server memory" with 0xFFFF !!! JRA.
+   */
+  SSVAL(p,2,0xFFE0);
   p += 4;
 
   if (cli_api(cli, 
               param, PTR_DIFF(p,param), 1024,  /* Param, length, maxlen */
-              NULL, 0, 0xFFFF,            /* data, length, maxlen */
+              NULL, 0, 0xFFE0,            /* data, length, maxlen - Win2k needs a small buffer here too ! */
               &rparam, &rprcnt,                /* return params, length */
               &rdata, &rdrcnt))                /* return data, length */
     {
--- client/client.c.orig	Wed Nov 10 18:35:59 1999
+++ client/client.c	Fri Feb 25 10:33:37 2000
@@ -1555,10 +1555,15 @@
 ****************************************************************************/
 static BOOL browse_host(BOOL sort)
 {
+	int ret;
+
         printf("\n\tSharename      Type      Comment\n");
         printf("\t---------      ----      -------\n");
 
-	return cli_RNetShareEnum(cli, browse_fn);
+	if((ret = cli_RNetShareEnum(cli, browse_fn)) == -1)
+		printf("Error returning browse list: %s\n", cli_errstr(cli));
+
+	return (ret != -1);
 }
 
 /****************************************************************************
--- include/proto.h.orig	Fri Feb 25 10:36:38 2000
+++ include/proto.h	Fri Feb 25 10:37:02 2000
@@ -435,7 +435,7 @@
 	     char **rparam, int *rprcnt,
 	     char **rdata, int *rdrcnt);
 BOOL cli_NetWkstaUserLogon(struct cli_state *cli,char *user, char *workstation);
-BOOL cli_RNetShareEnum(struct cli_state *cli, void (*fn)(const char *, uint32, const char *));
+int cli_RNetShareEnum(struct cli_state *cli, void (*fn)(const char *, uint32, const char *));
 BOOL cli_NetServerEnum(struct cli_state *cli, char *workgroup, uint32 stype,
 		       void (*fn)(const char *, uint32, const char *));
 BOOL cli_session_setup(struct cli_state *cli, 
---------------------cut here-----------------------------
-- 
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