diff options
Diffstat (limited to 'source/libsmb/namecache.c')
-rw-r--r-- | source/libsmb/namecache.c | 404 |
1 files changed, 174 insertions, 230 deletions
diff --git a/source/libsmb/namecache.c b/source/libsmb/namecache.c index e3e7ac4e3c2..6ab20e42741 100644 --- a/source/libsmb/namecache.c +++ b/source/libsmb/namecache.c @@ -1,10 +1,9 @@ /* Unix SMB/CIFS implementation. - NetBIOS name cache module on top of gencache mechanism. - - Copyright (C) Tim Potter 2002 - Copyright (C) Rafal Szczesniak 2002 + 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 @@ -23,299 +22,244 @@ #include "includes.h" -#define NBTKEY_FMT "NBT/%s#%02X" +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[1]; /* Address list */ +}; -/** - * Initialise namecache system. Function calls gencache - * initialisation function to perform necessary actions - * - * @return true upon successful initialisation of the cache or - * false on failure - **/ +/* Initialise namecache system */ BOOL namecache_enable(void) { - /* - * Check if name caching disabled by setting the name cache - * timeout to zero. - */ + /* 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; if (lp_name_cache_timeout() == 0) { - DEBUG(5, ("namecache_enable: disabling netbios name cache\n")); + DEBUG(5, ("namecache_init: disabling netbios name cache\n")); return False; } - /* Init namecache by calling gencache initialisation */ + /* Open namecache tdb in read/write or readonly mode */ - if (!gencache_init()) { - DEBUG(2, ("namecache_enable: Couldn't initialise namecache on top of gencache.\n")); + 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 False; } - /* 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 " + DEBUG(5, ("namecache_init: 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. */ -/** - * 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) +static TDB_DATA namecache_key(const char *name, int name_type) { - 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; -} + TDB_DATA retval; + char *keystr; + + asprintf(&keystr, "%s#%02X", strupper_static(name), name_type); + + retval.dsize = strlen(keystr) + 1; + retval.dptr = keystr; + return retval; +} -/** - * 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 - */ +/* Return a data value for an IP list. The caller must free + retval.dptr when finished. */ -static char* namecache_key(const char *name, int name_type) +static TDB_DATA namecache_value(struct in_addr *ip_list, int num_names, + time_t expiry) { - char *keystr; - asprintf(&keystr, NBTKEY_FMT, strupper_static(name), name_type); + TDB_DATA retval; + struct nc_value *value; + int size = sizeof(struct nc_value); - return keystr; -} + if (num_names > 0) + size += sizeof(struct in_addr) * (num_names-1); + + value = (struct nc_value *)malloc(size); + + memset(value, 0, size); + value->expiry = expiry; + value->count = num_names; -/** - * 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 - **/ + if (ip_list) + memcpy(value->ip_list, ip_list, sizeof(struct in_addr) * num_names); -BOOL namecache_store(const char *name, int name_type, - int num_names, struct ip_service *ip_list) + 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; - char *key, *value_string; int i; - BOOL ret; - - /* - * we use gecache call to avoid annoying debug messages about - * initialised namecache again and again... - */ - if (!gencache_init()) return False; - - if ( DEBUGLEVEL >= 5 ) { - 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:%d%s", inet_ntoa(ip_list[i].ip), - ip_list[i].port, (i == (num_names - 1) ? "" : ","))); - - DEBUGADD(5, ("\n")); - } - + + 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); - expiry = time(NULL) + lp_name_cache_timeout(); - - /* - * Generate string representation of ip addresses list - * First, store the number of ip addresses and then - * place each single ip - */ - if (!ipstr_list_make(&value_string, ip_list, num_names)) { - SAFE_FREE(key); - SAFE_FREE(value_string); - return False; - } - - /* set the entry */ - ret = gencache_set(key, value_string, expiry); - SAFE_FREE(key); - SAFE_FREE(value_string); - return ret; + + /* 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. */ -/** - * 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 ip_service **ip_list, - int *num_names) +BOOL namecache_fetch(const char *name, int name_type, struct in_addr **ip_list, + int *num_names) { - char *key, *value; - time_t timeout; + TDB_DATA key, value; + struct nc_value *data = NULL; + time_t now; + int i; + *ip_list = NULL; *num_names = 0; - /* exit now if null pointers were passed as they're required further */ - if (!ip_list || !num_names) return False; - - if (!gencache_init()) + if (!enable_namecache) return False; - /* - * Use gencache interface - lookup the key - */ + /* Read value */ + key = namecache_key(name, name_type); - if (!gencache_get(key, &value, &timeout)) { - DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type)); - gencache_del(key); - SAFE_FREE(key); - SAFE_FREE(value); - 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); + value = tdb_fetch(namecache_tdb, key); - SAFE_FREE(key); - SAFE_FREE(value); - - return *num_names > 0; /* true only if some ip has been fetched */ -} + if (!value.dptr) { + DEBUG(5, ("namecache_fetch: %s#%02x not found\n", + name, name_type)); + goto done; + } + data = (struct nc_value *)value.dptr; -/** - * Delete single namecache entry. Look at the - * gencache_iterate definition. - * - **/ + /* Check expiry time */ -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)); -} + now = time(NULL); + if (now > data->expiry) { -/** - * 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 - **/ + DEBUG(5, ("namecache_fetch: entry for %s#%02x expired\n", + name, name_type)); -void namecache_flush(void) -{ - if (!gencache_init()) - return; + tdb_delete(namecache_tdb, key); - /* - * 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")); -} + SAFE_FREE(value.dptr); + value = tdb_null; -/* Construct a name status record key. */ + goto done; + } -static char *namecache_status_record_key(const char *name, int name_type1, - int name_type2, struct in_addr keyip) -{ - char *keystr; + if ((data->expiry - now) > lp_name_cache_timeout()) { - asprintf(&keystr, "NBT/%s#%02X.%02X.%s", - strupper_static(name), name_type1, name_type2, inet_ntoa(keyip)); - return keystr; -} + /* Someone may have changed the system time on us */ -/* Store a name status record. */ + DEBUG(5, ("namecache_fetch: entry for %s#%02x has bad expiry\n", + name, name_type)); -BOOL namecache_status_store(const char *keyname, int keyname_type, - int name_type, struct in_addr keyip, - const char *srvname) -{ - char *key; - time_t expiry; - BOOL ret; + tdb_delete(namecache_tdb, key); - if (!gencache_init()) - return False; + SAFE_FREE(value.dptr); + value = tdb_null; - key = namecache_status_record_key(keyname, keyname_type, name_type, keyip); - if (!key) - return False; + goto done; + } - expiry = time(NULL) + lp_name_cache_timeout(); - ret = gencache_set(key, srvname, expiry); + /* Extract and return namelist */ - if (ret) - DEBUG(5, ("namecache_status_store: entry %s -> %s\n", key, srvname )); - else - DEBUG(5, ("namecache_status_store: entry %s store failed.\n", key )); + 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) ? "" : ", ")); + + } + + DEBUGADD(5, ("\n")); - SAFE_FREE(key); - return ret; +done: + SAFE_FREE(key.dptr); + SAFE_FREE(value.dptr); + + return value.dsize > 0; } -/* Fetch a name status record. */ +/* Flush all names from the name cache */ -BOOL namecache_status_fetch(const char *keyname, int keyname_type, - int name_type, struct in_addr keyip, char *srvname_out) +void namecache_flush(void) { - char *key = NULL; - char *value = NULL; - time_t timeout; + int result; - if (!gencache_init()) - return False; - - key = namecache_status_record_key(keyname, keyname_type, name_type, keyip); - if (!key) - return False; + if (!namecache_tdb) + return; - if (!gencache_get(key, &value, &timeout)) { - DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n", key)); - gencache_del(key); - SAFE_FREE(key); - SAFE_FREE(value); - return False; - } else { - DEBUG(5, ("namecache_status_fetch: key %s -> %s\n", key, value )); - } + result = tdb_traverse(namecache_tdb, tdb_traverse_delete_fn, NULL); - strlcpy(srvname_out, value, 16); - SAFE_FREE(key); - SAFE_FREE(value); - return True; + 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")); } |