Initial revamp of the libsmbclient interface.

The libsmbclient interface has suffered from difficulty of improvement and
feature enrichment without causing ABI breakage.  Although there were a number
of issues, the primary ones were:

(a) the user of the library would manually manipulate the context structure
    members, meaning that nothing in the context structure could change other
    than adding stuff at the end;

(b) there were three methods of setting options: setting bits in a flags field
    within the context structure, setting explicit options variables within an
    options structure in the context structure, and by calling the
    smbc_option_set() function;

(c) the authentication callback did not traditionally provide enough
    information to the callee which required adding an option for a callback
    with a different signature, and now there are requests for even more
    information at the callback, requiring yet a third signature and option to
    set it (if we implement that feature).

This commit provides a reorganization of the code which fixes (a) and (b).
The context structure is now entirely opaque, and there are setter and getter
functions for manipulating it.  This makes maintaining ABI consistency much,
much easier.

Additionally, the options setting/getting has been unified into a single
mechanism using smbc_option_set() and smbc_option_get().

Yet to be completed is a refactoring of the authentication callback (c).

The test programs in examples/libsmbclient have been modified (if necessary;
some applications require no changes at all) for the new API and a few have
been minimally tested.

Derrell

source/libsmb/libsmb_misc.c

@@ -0,0 +1,73 @@
+/* 
+   Unix SMB/Netbios implementation.
+   SMB client library implementation
+   Copyright (C) Andrew Tridgell 1998
+   Copyright (C) Richard Sharpe 2000, 2002
+   Copyright (C) John Terpstra 2000
+   Copyright (C) Tom Jansen (Ninja ISD) 2002 
+   Copyright (C) Derrell Lipman 2003-2008
+   Copyright (C) Jeremy Allison 2007, 2008
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "libsmbclient.h"
+#include "libsmb_internal.h"
+
+
+/* 
+ * check if an element is part of the list. 
+ */
+int
+SMBC_dlist_contains(SMBCFILE * list, SMBCFILE *p)
+{
+	if (!p || !list) return False;
+	do {
+		if (p == list) return True;
+		list = list->next;
+	} while (list);
+	return False;
+}
+
+
+/*
+ * Convert an SMB error into a UNIX error ...
+ */
+int
+SMBC_errno(SMBCCTX *context,
+           struct cli_state *c)
+{
+	int ret = cli_errno(c);
+	
+        if (cli_is_dos_error(c)) {
+                uint8 eclass;
+                uint32 ecode;
+
+                cli_dos_error(c, &eclass, &ecode);
+                
+                DEBUG(3,("smbc_error %d %d (0x%x) -> %d\n", 
+                         (int)eclass, (int)ecode, (int)ecode, ret));
+        } else {
+                NTSTATUS status;
+
+                status = cli_nt_error(c);
+
+                DEBUG(3,("smbc errno %s -> %d\n",
+                         nt_errstr(status), ret));
+        }
+
+	return ret;
+}
+