1/* 2 Unix SMB/CIFS implementation. 3 4 NetBIOS name cache module on top of gencache mechanism. 5 6 Copyright (C) Tim Potter 2002 7 Copyright (C) Rafal Szczesniak 2002 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 2 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22*/ 23 24#include "includes.h" 25 26#define NBTKEY_FMT "NBT/%s#%02X" 27 28 29/** 30 * Initialise namecache system. Function calls gencache 31 * initialisation function to perform necessary actions 32 * 33 * @return true upon successful initialisation of the cache or 34 * false on failure 35 **/ 36 37BOOL namecache_enable(void) 38{ 39 /* 40 * Check if name caching disabled by setting the name cache 41 * timeout to zero. 42 */ 43 44 if (lp_name_cache_timeout() == 0) { 45 DEBUG(5, ("namecache_enable: disabling netbios name cache\n")); 46 return False; 47 } 48 49 /* Init namecache by calling gencache initialisation */ 50 51 if (!gencache_init()) { 52 DEBUG(2, ("namecache_enable: Couldn't initialise namecache on top of gencache.\n")); 53 return False; 54 } 55 56 /* I leave it for now, though I don't think we really need this (mimir, 27.09.2002) */ 57 DEBUG(5, ("namecache_enable: enabling netbios namecache, timeout %d " 58 "seconds\n", lp_name_cache_timeout())); 59 60 return True; 61} 62 63 64/** 65 * Shutdown namecache. Routine calls gencache close function 66 * to safely close gencache file. 67 * 68 * @return true upon successful shutdown of the cache or 69 * false on failure 70 **/ 71 72BOOL namecache_shutdown(void) 73{ 74 if (!gencache_shutdown()) { 75 DEBUG(2, ("namecache_shutdown: Couldn't close namecache on top of gencache.\n")); 76 return False; 77 } 78 79 DEBUG(5, ("namecache_shutdown: netbios namecache closed successfully.\n")); 80 return True; 81} 82 83 84/** 85 * Generates a key for netbios name lookups on basis of 86 * netbios name and type. 87 * The caller must free returned key string when finished. 88 * 89 * @param name netbios name string (case insensitive) 90 * @param name_type netbios type of the name being looked up 91 * 92 * @return string consisted of uppercased name and appended 93 * type number 94 */ 95 96static char* namecache_key(const char *name, int name_type) 97{ 98 char *keystr; 99 asprintf(&keystr, NBTKEY_FMT, strupper_static(name), name_type); 100 101 return keystr; 102} 103 104 105/** 106 * Store a name(s) in the name cache 107 * 108 * @param name netbios names array 109 * @param name_type integer netbios name type 110 * @param num_names number of names being stored 111 * @param ip_list array of in_addr structures containing 112 * ip addresses being stored 113 **/ 114 115BOOL namecache_store(const char *name, int name_type, 116 int num_names, struct ip_service *ip_list) 117{ 118 time_t expiry; 119 char *key, *value_string; 120 int i; 121 BOOL ret; 122 123 /* 124 * we use gecache call to avoid annoying debug messages about 125 * initialised namecache again and again... 126 */ 127 if (!gencache_init()) return False; 128 129 if ( DEBUGLEVEL >= 5 ) { 130 DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ", 131 num_names, num_names == 1 ? "": "es", name, name_type)); 132 133 for (i = 0; i < num_names; i++) 134 DEBUGADD(5, ("%s:%d%s", inet_ntoa(ip_list[i].ip), 135 ip_list[i].port, (i == (num_names - 1) ? "" : ","))); 136 137 DEBUGADD(5, ("\n")); 138 } 139 140 key = namecache_key(name, name_type); 141 expiry = time(NULL) + lp_name_cache_timeout(); 142 143 /* 144 * Generate string representation of ip addresses list 145 * First, store the number of ip addresses and then 146 * place each single ip 147 */ 148 if (!ipstr_list_make(&value_string, ip_list, num_names)) { 149 SAFE_FREE(key); 150 SAFE_FREE(value_string); 151 return False; 152 } 153 154 /* set the entry */ 155 ret = gencache_set(key, value_string, expiry); 156 SAFE_FREE(key); 157 SAFE_FREE(value_string); 158 return ret; 159} 160 161 162/** 163 * Look up a name in the cache. 164 * 165 * @param name netbios name to look up for 166 * @param name_type netbios name type of @param name 167 * @param ip_list mallocated list of IP addresses if found in the cache, 168 * NULL otherwise 169 * @param num_names number of entries found 170 * 171 * @return true upon successful fetch or 172 * false if name isn't found in the cache or has expired 173 **/ 174 175BOOL namecache_fetch(const char *name, int name_type, struct ip_service **ip_list, 176 int *num_names) 177{ 178 char *key, *value; 179 time_t timeout; 180 181 *num_names = 0; 182 183 /* exit now if null pointers were passed as they're required further */ 184 if (!ip_list || !num_names) return False; 185 186 if (!gencache_init()) 187 return False; 188 189 /* 190 * Use gencache interface - lookup the key 191 */ 192 key = namecache_key(name, name_type); 193 194 if (!gencache_get(key, &value, &timeout)) { 195 DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type)); 196 gencache_del(key); 197 SAFE_FREE(key); 198 SAFE_FREE(value); 199 return False; 200 } else { 201 DEBUG(5, ("name %s#%02X found.\n", name, name_type)); 202 } 203 204 /* 205 * Split up the stored value into the list of IP adresses 206 */ 207 *num_names = ipstr_list_parse(value, ip_list); 208 209 SAFE_FREE(key); 210 SAFE_FREE(value); 211 212 return *num_names > 0; /* true only if some ip has been fetched */ 213} 214 215 216/** 217 * Delete single namecache entry. Look at the 218 * gencache_iterate definition. 219 * 220 **/ 221 222static void flush_netbios_name(const char* key, const char *value, time_t timeout, void* dptr) 223{ 224 gencache_del(key); 225 DEBUG(5, ("Deleting entry %s\n", key)); 226} 227 228 229/** 230 * Flush all names from the name cache. 231 * It's done by gencache_iterate() 232 * 233 * @return True upon successful deletion or 234 * False in case of an error 235 **/ 236 237void namecache_flush(void) 238{ 239 if (!gencache_init()) 240 return; 241 242 /* 243 * iterate through each NBT cache's entry and flush it 244 * by flush_netbios_name function 245 */ 246 gencache_iterate(flush_netbios_name, NULL, "NBT/*"); 247 DEBUG(5, ("Namecache flushed\n")); 248} 249 250/* Construct a name status record key. */ 251 252static char *namecache_status_record_key(const char *name, int name_type1, 253 int name_type2, struct in_addr keyip) 254{ 255 char *keystr; 256 257 asprintf(&keystr, "NBT/%s#%02X.%02X.%s", 258 strupper_static(name), name_type1, name_type2, inet_ntoa(keyip)); 259 return keystr; 260} 261 262/* Store a name status record. */ 263 264BOOL namecache_status_store(const char *keyname, int keyname_type, 265 int name_type, struct in_addr keyip, 266 const char *srvname) 267{ 268 char *key; 269 time_t expiry; 270 BOOL ret; 271 272 if (!gencache_init()) 273 return False; 274 275 key = namecache_status_record_key(keyname, keyname_type, name_type, keyip); 276 if (!key) 277 return False; 278 279 expiry = time(NULL) + lp_name_cache_timeout(); 280 ret = gencache_set(key, srvname, expiry); 281 282 if (ret) 283 DEBUG(5, ("namecache_status_store: entry %s -> %s\n", key, srvname )); 284 else 285 DEBUG(5, ("namecache_status_store: entry %s store failed.\n", key )); 286 287 SAFE_FREE(key); 288 return ret; 289} 290 291/* Fetch a name status record. */ 292 293BOOL namecache_status_fetch(const char *keyname, int keyname_type, 294 int name_type, struct in_addr keyip, char *srvname_out) 295{ 296 char *key = NULL; 297 char *value = NULL; 298 time_t timeout; 299 300 if (!gencache_init()) 301 return False; 302 303 key = namecache_status_record_key(keyname, keyname_type, name_type, keyip); 304 if (!key) 305 return False; 306 307 if (!gencache_get(key, &value, &timeout)) { 308 DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n", key)); 309 gencache_del(key); 310 SAFE_FREE(key); 311 SAFE_FREE(value); 312 return False; 313 } else { 314 DEBUG(5, ("namecache_status_fetch: key %s -> %s\n", key, value )); 315 } 316 317 strlcpy(srvname_out, value, 16); 318 SAFE_FREE(key); 319 SAFE_FREE(value); 320 return True; 321} 322