1 files changed, 158 insertions, 0 deletions
diff --git a/source3/libsmb/conncache.c b/source3/libsmb/conncache.c
new file mode 100644
index 0000000000..e6604617d6
--- /dev/null
+++ b/source3/libsmb/conncache.c
@@ -0,0 +1,158 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Winbind daemon connection manager
+
+   Copyright (C) Tim Potter 		2001
+   Copyright (C) Andrew Bartlett 	2002
+   Copyright (C) Gerald (Jerry) Carter 	2003
+   
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+#include "includes.h"
+
+#define FAILED_CONNECTION_CACHE_TIMEOUT 30 /* Seconds between attempts */
+
+#define CONNCACHE_ADDR		1
+#define CONNCACHE_NAME		2
+
+/* cache entry contains either a server name **or** and IP address as 
+   the key.  This means that a server could have two entries (one for each key) */
+   
+struct failed_connection_cache {
+	fstring 	domain_name;
+	fstring 	controller;
+	time_t 		lookup_time;
+	NTSTATUS 	nt_status;
+	struct failed_connection_cache *prev, *next;
+};
+
+static struct failed_connection_cache *failed_connection_cache;
+
+/**********************************************************************
+ Check for a previously failed connection
+**********************************************************************/
+
+NTSTATUS check_negative_conn_cache( const char *domain, const char *server )
+{
+	struct failed_connection_cache *fcc;
+	NTSTATUS result = NT_STATUS_UNSUCCESSFUL;
+	
+	/* can't check if we don't have strings */
+	
+	if ( !domain || !server )
+		return NT_STATUS_OK;
+
+	for (fcc = failed_connection_cache; fcc; fcc = fcc->next) {
+	
+		if ( !(strequal(domain, fcc->domain_name) && strequal(server, fcc->controller)) )
+			continue; /* no match; check the next entry */
+		
+		/* we have a match so see if it is still current */
+
+		if ((time(NULL) - fcc->lookup_time) > FAILED_CONNECTION_CACHE_TIMEOUT) 
+		{
+			/* Cache entry has expired, delete it */
+
+			DEBUG(10, ("check_negative_conn_cache: cache entry expired for %s, %s\n", 
+				domain, server ));
+
+			DLIST_REMOVE(failed_connection_cache, fcc);
+			SAFE_FREE(fcc);
+
+			return NT_STATUS_OK;
+		}
+
+		/* The timeout hasn't expired yet so return false */
+
+		DEBUG(10, ("check_negative_conn_cache: returning negative entry for %s, %s\n", 
+			domain, server ));
+
+		result = fcc->nt_status;
+		return result;
+	}
+
+	/* end of function means no cache entry */	
+	return NT_STATUS_OK;
+}
+
+/**********************************************************************
+ Add an entry to the failed conneciton cache (aither a name of dotted 
+ decimal IP
+**********************************************************************/
+
+void add_failed_connection_entry(const char *domain, const char *server, NTSTATUS result) 
+{
+	struct failed_connection_cache *fcc;
+
+	SMB_ASSERT(!NT_STATUS_IS_OK(result));
+
+	/* Check we already aren't in the cache.  We always have to have 
+	   a domain, but maybe not a specific DC name. */
+
+	for (fcc = failed_connection_cache; fcc; fcc = fcc->next) {			
+		if ( strequal(fcc->domain_name, domain) && strequal(fcc->controller, server) ) 
+		{
+			DEBUG(10, ("add_failed_connection_entry: domain %s (%s) already tried and failed\n",
+				   domain, server ));
+			return;
+		}
+	}
+
+	/* Create negative lookup cache entry for this domain and controller */
+
+	if ( !(fcc = (struct failed_connection_cache *)malloc(sizeof(struct failed_connection_cache))) ) 
+	{
+		DEBUG(0, ("malloc failed in add_failed_connection_entry!\n"));
+		return;
+	}
+	
+	ZERO_STRUCTP(fcc);
+	
+	fstrcpy( fcc->domain_name, domain );
+	fstrcpy( fcc->controller, server );
+	fcc->lookup_time = time(NULL);
+	fcc->nt_status = result;
+	
+	DEBUG(10,("add_failed_connection_entry: added domain %s (%s) to failed conn cache\n",
+		domain, server ));
+	
+	DLIST_ADD(failed_connection_cache, fcc);
+}
+
+/****************************************************************************
+****************************************************************************/
+ 
+void flush_negative_conn_cache( void )
+{
+	struct failed_connection_cache *fcc;
+	
+	fcc = failed_connection_cache;
+
+	while (fcc) {
+		struct failed_connection_cache *fcc_next;
+
+		fcc_next = fcc->next;
+		DLIST_REMOVE(failed_connection_cache, fcc);
+		free(fcc);
+
+		fcc = fcc_next;
+	}
+
+}
+
+