This commit was manufactured by cvs2svn to create branch 'SAMBA_3_0'.(This used to be commit 6938b5b98abd9ba055a46583a05c4fc07e32f529)

1 files changed, 252 insertions, 0 deletions

diff --git a/source3/libsmb/namecache.c b/source3/libsmb/namecache.c
new file mode 100644
index 0000000000..fc09d8eac2
--- /dev/null
+++ b/source3/libsmb/namecache.c
@@ -0,0 +1,252 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   NetBIOS name cache module.
+
+   Copyright (C) Tim Potter, 2002
+   
+   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"
+
+static BOOL done_namecache_init;
+static BOOL enable_namecache;
+static TDB_CONTEXT *namecache_tdb;
+
+struct nc_value {
+	time_t expiry;		     /* When entry expires */
+	int count;		     /* Number of addresses */
+	struct in_addr ip_list[0];   /* Address list */
+};
+
+/* Initialise namecache system */
+
+void namecache_enable(void)
+{
+	/* Check if we have been here before, or name caching disabled
+           by setting the name cache timeout to zero. */ 
+
+	if (done_namecache_init)
+		return;
+
+	done_namecache_init = True;
+
+	if (lp_name_cache_timeout() == 0) {
+		DEBUG(5, ("namecache_init: disabling netbios name cache\n"));
+		return;
+	}
+
+	/* Open namecache tdb in read/write or readonly mode */
+
+	namecache_tdb = tdb_open_log(
+		lock_path("namecache.tdb"), 0,
+		TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
+
+	if (!namecache_tdb) {
+		DEBUG(5, ("namecache_init: could not open %s\n",
+			  lock_path("namecache.tdb")));
+		return;
+	}
+
+	DEBUG(5, ("namecache_init: enabling netbios namecache, timeout %d "
+		  "seconds\n", lp_name_cache_timeout()));
+
+	enable_namecache = True;
+}
+
+/* Return a key for a name and name type.  The caller must free
+   retval.dptr when finished. */
+
+static TDB_DATA namecache_key(const char *name, int name_type)
+{
+	TDB_DATA retval;
+	char *keystr;
+
+	asprintf(&keystr, "%s#%02X", strupper_static(name), name_type);
+
+	retval.dsize = strlen(keystr) + 1;
+	retval.dptr = keystr;
+
+	return retval;
+}
+
+/* Return a data value for an IP list.  The caller must free
+   retval.dptr when finished. */
+
+static TDB_DATA namecache_value(struct in_addr *ip_list, int num_names, 
+				time_t expiry)
+{
+	TDB_DATA retval;
+	struct nc_value *value;
+	int size;
+
+	size = sizeof(struct nc_value) + sizeof(struct in_addr) *
+		num_names;
+
+	value = (struct nc_value *)malloc(size);
+		
+	value->expiry = expiry;
+	value->count = num_names;
+
+	memcpy(value->ip_list, ip_list, num_names * sizeof(struct in_addr));
+
+	retval.dptr = (char *)value;
+	retval.dsize = size;
+
+	return retval;
+}
+
+/* Store a name in the name cache */
+
+void namecache_store(const char *name, int name_type,
+		     int num_names, struct in_addr *ip_list)
+{
+	TDB_DATA key, value;
+	time_t expiry;
+	int i;
+
+	if (!enable_namecache)
+		return;
+
+	DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
+		  num_names, num_names == 1 ? "": "es", name, name_type));
+
+	for (i = 0; i < num_names; i++) 
+		DEBUGADD(5, ("%s%s", inet_ntoa(ip_list[i]),
+			     i == (num_names - 1) ? "" : ", "));
+
+	DEBUGADD(5, ("\n"));
+
+	key = namecache_key(name, name_type);
+
+	/* Cache pdc location or dc lists for only a little while
+	   otherwise if we lock on to a bad DC we can potentially be
+	   out of action for the entire cache timeout time! */
+
+	if (name_type != 0x1b || name_type != 0x1c)
+		expiry = time(NULL) + 10;
+	else
+		expiry = time(NULL) + lp_name_cache_timeout();
+
+	value = namecache_value(ip_list, num_names, expiry);
+
+	tdb_store(namecache_tdb, key, value, TDB_REPLACE);
+
+	free(key.dptr);
+	free(value.dptr);
+}
+
+/* Look up a name in the name cache.  Return a mallocated list of IP
+   addresses if the name is contained in the cache. */
+
+BOOL namecache_fetch(const char *name, int name_type, struct in_addr **ip_list,
+		     int *num_names)
+{
+	TDB_DATA key, value;
+	struct nc_value *data;
+	time_t now;
+	int i;
+
+	if (!enable_namecache)
+		return False;
+
+	/* Read value */
+
+	key = namecache_key(name, name_type);
+
+	value = tdb_fetch(namecache_tdb, key);
+	
+	if (!value.dptr) {
+		DEBUG(5, ("namecache_fetch: %s#%02x not found\n",
+			  name, name_type));
+		goto done;
+	}
+
+	data = (struct nc_value *)value.dptr;
+
+	/* Check expiry time */
+
+	now = time(NULL);
+
+	if (now > data->expiry) {
+
+		DEBUG(5, ("namecache_fetch: entry for %s#%02x expired\n",
+			  name, name_type));
+
+		tdb_delete(namecache_tdb, key);
+
+		value = tdb_null;
+
+		goto done;
+	}
+
+	if ((data->expiry - now) > lp_name_cache_timeout()) {
+
+		/* Someone may have changed the system time on us */
+
+		DEBUG(5, ("namecache_fetch: entry for %s#%02x has bad expiry\n",
+			  name, name_type));
+
+		tdb_delete(namecache_tdb, key);
+
+		value = tdb_null;
+
+		goto done;
+	}
+
+	/* Extract and return namelist */
+
+	*ip_list = (struct in_addr *)malloc(
+		sizeof(struct in_addr) * data->count);
+	
+	memcpy(*ip_list, data->ip_list, sizeof(struct in_addr) *
+	       data->count);
+
+	*num_names = data->count;
+
+	DEBUG(5, ("namecache_fetch: returning %d address%s for %s#%02x: ",
+		  *num_names, *num_names == 1 ? "" : "es", name, name_type));
+
+	for (i = 0; i < *num_names; i++)
+		DEBUGADD(5, ("%s%s", inet_ntoa((*ip_list)[i]),
+			     i == (*num_names - 1) ? "" : ", "));
+
+	DEBUGADD(5, ("\n"));
+
+done:
+	SAFE_FREE(key.dptr);
+	SAFE_FREE(value.dptr);
+
+	return value.dsize > 0;
+}
+
+/* Flush all names from the name cache */
+
+void namecache_flush(void)
+{
+	int result;
+
+	if (!namecache_tdb)
+		return;
+
+	result = tdb_traverse(namecache_tdb, tdb_traverse_delete_fn, NULL);
+
+	if (result == -1)
+		DEBUG(5, ("namecache_flush: error deleting cache entries\n"));
+	else
+		DEBUG(5, ("namecache_flush: deleted %d cache entr%s\n", 
+			  result, result == 1 ? "y" : "ies"));
+}