Merge from HEAD - mimir's new gencache based namecache code.

Andrew Bartlett
(This used to be commit f79324f730c400342f445c931b0d75ff756d7cc7)

1 files changed, 153 insertions, 170 deletions

diff --git a/source3/libsmb/namecache.c b/source3/libsmb/namecache.c
index 724e0237d2..40777011a1 100644
--- a/source3/libsmb/namecache.c
+++ b/source3/libsmb/namecache.c
@@ -1,9 +1,10 @@
 /* 
    Unix SMB/CIFS implementation.
 
-   NetBIOS name cache module.
-
-   Copyright (C) Tim Potter, 2002
+   NetBIOS name cache module on top of gencache mechanism.
+   
+   Copyright (C) Tim Potter         2002
+   Copyright (C) Rafal Szczesniak   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
@@ -22,242 +23,224 @@
 
 #include "includes.h"
 
-static BOOL done_namecache_init;
-static BOOL enable_namecache;
-static TDB_CONTEXT *namecache_tdb;
+#define NBTKEY_FMT  "NBT/%s#%02X"
 
-struct nc_value {
-	time_t expiry;		     /* When entry expires */
-	int count;		     /* Number of addresses */
-	struct in_addr ip_list[1];   /* Address list */
-};
 
-/* Initialise namecache system */
+/**
+ * Initialise namecache system. Function calls gencache
+ * initialisation function to perform necessary actions
+ * 
+ * @return true upon successful initialisation of the cache or
+ *         false on failure
+ **/
 
 BOOL 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 False;
-
-	done_namecache_init = True;
+	/*
+	 * Check if name caching disabled by setting the name cache
+	 * timeout to zero.
+	 */ 
 
 	if (lp_name_cache_timeout() == 0) {
-		DEBUG(5, ("namecache_init: disabling netbios name cache\n"));
+		DEBUG(5, ("namecache_enable: disabling netbios name cache\n"));
 		return False;
 	}
 
-	/* Open namecache tdb in read/write or readonly mode */
+	/* Init namecache by calling gencache initialisation */
 
-	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")));
+	if (!gencache_init()) {
+		DEBUG(2, ("namecache_enable: Couldn't initialise namecache on top of gencache.\n"));
 		return False;
 	}
 
-	DEBUG(5, ("namecache_init: enabling netbios namecache, timeout %d "
+	/* I leave it for now, though I don't think we really need this (mimir, 27.09.2002) */
+	DEBUG(5, ("namecache_enable: enabling netbios namecache, timeout %d "
 		  "seconds\n", lp_name_cache_timeout()));
 
-	enable_namecache = True;
-
 	return 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)
+/**
+ * Shutdown namecache. Routine calls gencache close function
+ * to safely close gencache file.
+ *
+ * @return true upon successful shutdown of the cache or
+ *         false on failure
+ **/
+ 
+BOOL namecache_shutdown(void)
 {
-	TDB_DATA retval;
-	char *keystr;
-
-	asprintf(&keystr, "%s#%02X", strupper_static(name), name_type);
-
-	retval.dsize = strlen(keystr) + 1;
-	retval.dptr = keystr;
-
-	return retval;
+	if (!gencache_shutdown()) {
+		DEBUG(2, ("namecache_shutdown: Couldn't close namecache on top of gencache.\n"));
+		return False;
+	}
+	
+	DEBUG(5, ("namecache_shutdown: netbios namecache closed successfully.\n"));
+	return True;
 }
 
-/* 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 = sizeof(struct nc_value);
 
-	if (num_names > 0)
-		size += sizeof(struct in_addr) * (num_names-1);
+/**
+ * Generates a key for netbios name lookups on basis of
+ * netbios name and type.
+ * The caller must free returned key string when finished.
+ *
+ * @param name netbios name string (case insensitive)
+ * @param name_type netbios type of the name being looked up
+ *
+ * @return string consisted of uppercased name and appended
+ *         type number
+ */
 
-	value = (struct nc_value *)malloc(size);
-
-	memset(value, 0, size);
-
-	value->expiry = expiry;
-	value->count = num_names;
-
-	if (ip_list)
-		memcpy(value->ip_list, ip_list, sizeof(struct in_addr) * num_names);
-
-	retval.dptr = (char *)value;
-	retval.dsize = size;
+static char* namecache_key(const char *name, int name_type)
+{
+	char *keystr;
+	asprintf(&keystr, NBTKEY_FMT, strupper_static(name), name_type);
 
-	return retval;
+	return keystr;
 }
 
-/* Store a name in the name cache */
 
-void namecache_store(const char *name, int name_type,
-		     int num_names, struct in_addr *ip_list)
+/**
+ * Store a name(s) in the name cache
+ *
+ * @param name netbios names array
+ * @param name_type integer netbios name type
+ * @param num_names number of names being stored
+ * @param ip_list array of in_addr structures containing
+ *        ip addresses being stored
+ **/
+
+BOOL namecache_store(const char *name, int name_type,
+                     int num_names, struct in_addr *ip_list)
 {
-	TDB_DATA key, value;
 	time_t expiry;
+	char *key, *value_string;
 	int i;
 
-	if (!enable_namecache)
-		return;
+	/*
+	 * we use gecache call to avoid annoying debug messages about
+	 * initialised namecache again and again...
+	 */
+	if (!gencache_init()) return False;
 
 	DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
-		  num_names, num_names == 1 ? "": "es", name, name_type));
+	          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) ? "" : ", "));
+		             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! */
+	/* 
+	 * 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)
+	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);
+	/*
+	 * Generate string representation of ip addresses list
+	 * First, store the number of ip addresses and then
+	 * place each single ip
+	 */
+	ipstr_list_make(&value_string, ip_list, num_names);
+	
+	/* set the entry */
+	return (gencache_set(key, value_string, expiry));
 }
 
-/* Look up a name in the name cache.  Return a mallocated list of IP
-   addresses if the name is contained in the cache. */
+
+/**
+ * Look up a name in the cache.
+ *
+ * @param name netbios name to look up for
+ * @param name_type netbios name type of @param name
+ * @param ip_list mallocated list of IP addresses if found in the cache,
+ *        NULL otherwise
+ * @param num_names number of entries found
+ *
+ * @return true upon successful fetch or
+ *         false if name isn't found in the cache or has expired
+ **/
 
 BOOL namecache_fetch(const char *name, int name_type, struct in_addr **ip_list,
-		     int *num_names)
+                     int *num_names)
 {
-	TDB_DATA key, value;
-	struct nc_value *data = NULL;
-	time_t now;
-	int i;
+	char *key, *value;
+	time_t timeout;
 
-	*ip_list = NULL;
 	*num_names = 0;
 
-	if (!enable_namecache)
-		return False;
+	/* exit now if null pointers were passed as they're required further */
+	if (!ip_list || !num_names) return False;
 
-	/* Read value */
+	if (!gencache_init())
+		return False;
 
+	/* 
+	 * Use gencache interface - lookup the key
+	 */
 	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 */
-
-	DEBUG(5, ("namecache_fetch: returning %d address%s for %s#%02x: ",
-		  data->count, data->count == 1 ? "" : "es", name, name_type));
-
-	if (data->count) {
-
-		*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;
-		
-		for (i = 0; i < *num_names; i++)
-			DEBUGADD(5, ("%s%s", inet_ntoa((*ip_list)[i]),
-				     i == (*num_names - 1) ? "" : ", "));
-
+	if (!gencache_get(key, &value, &timeout)) {
+		DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
+		SAFE_FREE(key);
+		return False;
+	} else {
+		DEBUG(5, ("name %s#%02X found.\n", name, name_type));
 	}
+	
+	/*
+	 * Split up the stored value into the list of IP adresses
+	 */
+	*num_names = ipstr_list_parse(value, ip_list);
+	
+	SAFE_FREE(key);
+	SAFE_FREE(value);		 
+	return *num_names > 0;		/* true only if some ip has been fetched */
+}
 
-	DEBUGADD(5, ("\n"));
 
-done:
-	SAFE_FREE(key.dptr);
-	SAFE_FREE(data);
+/**
+ * Delete single namecache entry. Look at the
+ * gencache_iterate definition.
+ *
+ **/
 
-	return value.dsize > 0;
+static void flush_netbios_name(const char* key, const char *value, time_t timeout, void* dptr)
+{
+	gencache_del(key);
+	DEBUG(5, ("Deleting entry %s\n", key));
 }
 
-/* Flush all names from the name cache */
+
+/**
+ * Flush all names from the name cache.
+ * It's done by gencache_iterate()
+ *
+ * @return True upon successful deletion or
+ *         False in case of an error
+ **/
 
 void namecache_flush(void)
 {
-	int result;
-
-	if (!namecache_tdb)
+	if (!gencache_init())
 		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"));
+	/* 
+	 * iterate through each NBT cache's entry and flush it
+	 * by flush_netbios_name function
+	 */
+	gencache_iterate(flush_netbios_name, NULL, "NBT/*");
+	DEBUG(5, ("Namecache flushed\n"));
 }
+