source/lib/dbwrap_tdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Database interface wrapper around tdb
   4    Copyright (C) Volker Lendecke 2005-2007
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 struct db_tdb_ctx {
  23         struct tdb_wrap *wtdb;
  24 };
  25
  26 static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag);
  27 static NTSTATUS db_tdb_delete(struct db_record *rec);
  28
  29 static int db_tdb_record_destr(struct db_record* data)
  30 {
  31         struct db_tdb_ctx *ctx =
  32                 talloc_get_type_abort(data->private_data, struct db_tdb_ctx);
  33
  34         /* This hex_encode() call allocates memory on data context. By way how current
  35            __talloc_free() code works, it is OK to allocate in the destructor as
  36            the children of data will be freed after call to the destructor and this
  37            new 'child' will be caught and freed correctly.
  38          */
  39         DEBUG(10, (DEBUGLEVEL > 10
  40                    ? "Unlocking key %s\n" : "Unlocking key %.20s\n",
  41                    hex_encode(data, (unsigned char *)data->key.dptr,
  42                               data->key.dsize)));
  43
  44         if (tdb_chainunlock(ctx->wtdb->tdb, data->key) != 0) {
  45                 DEBUG(0, ("tdb_chainunlock failed\n"));
  46                 return -1;
  47         }
  48         return 0;
  49 }
  50
  51 struct tdb_fetch_locked_state {
  52         TALLOC_CTX *mem_ctx;
  53         struct db_record *result;
  54 };
  55
  56 static int db_tdb_fetchlock_parse(TDB_DATA key, TDB_DATA data,
  57                                   void *private_data)
  58 {
  59         struct tdb_fetch_locked_state *state =
  60                 (struct tdb_fetch_locked_state *)private_data;
  61
  62         state->result = (struct db_record *)talloc_size(
  63                 state->mem_ctx,
  64                 sizeof(struct db_record) + key.dsize + data.dsize);
  65
  66         if (state->result == NULL) {
  67                 return 0;
  68         }
  69
  70         state->result->key.dsize = key.dsize;
  71         state->result->key.dptr = ((uint8 *)state->result)
  72                 + sizeof(struct db_record);
  73         memcpy(state->result->key.dptr, key.dptr, key.dsize);
  74
  75         state->result->value.dsize = data.dsize;
  76
  77         if (data.dsize > 0) {
  78                 state->result->value.dptr = state->result->key.dptr+key.dsize;
  79                 memcpy(state->result->value.dptr, data.dptr, data.dsize);
  80         }
  81         else {
  82                 state->result->value.dptr = NULL;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static struct db_record *db_tdb_fetch_locked(struct db_context *db,
  89                                      TALLOC_CTX *mem_ctx, TDB_DATA key)
  90 {
  91         struct db_tdb_ctx *ctx = talloc_get_type_abort(db->private_data,
  92                                                        struct db_tdb_ctx);
  93         struct tdb_fetch_locked_state state;
  94
  95         /* Do not accidently allocate/deallocate w/o need when debug level is lower than needed */
  96         if(DEBUGLEVEL >= 10) {
  97                 char *keystr = hex_encode(NULL, (unsigned char*)key.dptr, key.dsize);
  98                 DEBUG(10, (DEBUGLEVEL > 10
  99                            ? "Locking key %s\n" : "Locking key %.20s\n",
 100                            keystr));
 101                 TALLOC_FREE(keystr);
 102         }
 103
 104         if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
 105                 DEBUG(3, ("tdb_chainlock failed\n"));
 106                 return NULL;
 107         }
 108
 109         state.mem_ctx = mem_ctx;
 110         state.result = NULL;
 111
 112         tdb_parse_record(ctx->wtdb->tdb, key, db_tdb_fetchlock_parse, &state);
 113
 114         if (state.result == NULL) {
 115                 db_tdb_fetchlock_parse(key, tdb_null, &state);
 116         }
 117
 118         if (state.result == NULL) {
 119                 tdb_chainunlock(ctx->wtdb->tdb, key);
 120                 return NULL;
 121         }
 122
 123         talloc_set_destructor(state.result, db_tdb_record_destr);
 124
 125         state.result->private_data = talloc_reference(state.result, ctx);
 126         state.result->store = db_tdb_store;
 127         state.result->delete_rec = db_tdb_delete;
 128
 129         DEBUG(10, ("Allocated locked data 0x%p\n", state.result));
 130
 131         return state.result;
 132 }
 133
 134 struct tdb_fetch_state {
 135         TALLOC_CTX *mem_ctx;
 136         int result;
 137         TDB_DATA data;
 138 };
 139
 140 static int db_tdb_fetch_parse(TDB_DATA key, TDB_DATA data,
 141                               void *private_data)
 142 {
 143         struct tdb_fetch_state *state =
 144                 (struct tdb_fetch_state *)private_data;
 145
 146         state->data.dptr = (uint8 *)talloc_memdup(state->mem_ctx, data.dptr,
 147                                                   data.dsize);
 148         if (state->data.dptr == NULL) {
 149                 state->result = -1;
 150                 return 0;
 151         }
 152
 153         state->data.dsize = data.dsize;
 154         return 0;
 155 }
 156
 157 static int db_tdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 158                         TDB_DATA key, TDB_DATA *pdata)
 159 {
 160         struct db_tdb_ctx *ctx = talloc_get_type_abort(
 161                 db->private_data, struct db_tdb_ctx);
 162
 163         struct tdb_fetch_state state;
 164
 165         state.mem_ctx = mem_ctx;
 166         state.result = 0;
 167         state.data = tdb_null;
 168
 169         tdb_parse_record(ctx->wtdb->tdb, key, db_tdb_fetch_parse, &state);
 170
 171         if (state.result == -1) {
 172                 return -1;
 173         }
 174
 175         *pdata = state.data;
 176         return 0;
 177 }
 178
 179 static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag)
 180 {
 181         struct db_tdb_ctx *ctx = talloc_get_type_abort(rec->private_data,
 182                                                        struct db_tdb_ctx);
 183
 184         /*
 185          * This has a bug: We need to replace rec->value for correct
 186          * operation, but right now brlock and locking don't use the value
 187          * anymore after it was stored.
 188          */
 189
 190         return (tdb_store(ctx->wtdb->tdb, rec->key, data, flag) == 0) ?
 191                 NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
 192 }
 193
 194 static NTSTATUS db_tdb_delete(struct db_record *rec)
 195 {
 196         struct db_tdb_ctx *ctx = talloc_get_type_abort(rec->private_data,
 197                                                        struct db_tdb_ctx);
 198
 199         if (tdb_delete(ctx->wtdb->tdb, rec->key) == 0) {
 200                 return NT_STATUS_OK;
 201         }
 202
 203         if (tdb_error(ctx->wtdb->tdb) == TDB_ERR_NOEXIST) {
 204                 return NT_STATUS_NOT_FOUND;
 205         }
 206
 207         return NT_STATUS_UNSUCCESSFUL;
 208 }
 209
 210 struct db_tdb_traverse_ctx {
 211         struct db_context *db;
 212         int (*f)(struct db_record *rec, void *private_data);
 213         void *private_data;
 214 };
 215
 216 static int db_tdb_traverse_func(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
 217                                 void *private_data)
 218 {
 219         struct db_tdb_traverse_ctx *ctx =
 220                 (struct db_tdb_traverse_ctx *)private_data;
 221         struct db_record rec;
 222
 223         rec.key = kbuf;
 224         rec.value = dbuf;
 225         rec.store = db_tdb_store;
 226         rec.delete_rec = db_tdb_delete;
 227         rec.private_data = ctx->db->private_data;
 228
 229         return ctx->f(&rec, ctx->private_data);
 230 }
 231
 232 static int db_tdb_traverse(struct db_context *db,
 233                            int (*f)(struct db_record *rec, void *private_data),
 234                            void *private_data)
 235 {
 236         struct db_tdb_ctx *db_ctx =
 237                 talloc_get_type_abort(db->private_data, struct db_tdb_ctx);
 238         struct db_tdb_traverse_ctx ctx;
 239
 240         ctx.db = db;
 241         ctx.f = f;
 242         ctx.private_data = private_data;
 243         return tdb_traverse(db_ctx->wtdb->tdb, db_tdb_traverse_func, &ctx);
 244 }
 245
 246 static NTSTATUS db_tdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
 247 {
 248         return NT_STATUS_MEDIA_WRITE_PROTECTED;
 249 }
 250
 251 static NTSTATUS db_tdb_delete_deny(struct db_record *rec)
 252 {
 253         return NT_STATUS_MEDIA_WRITE_PROTECTED;
 254 }
 255
 256 static int db_tdb_traverse_read_func(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
 257                                 void *private_data)
 258 {
 259         struct db_tdb_traverse_ctx *ctx =
 260                 (struct db_tdb_traverse_ctx *)private_data;
 261         struct db_record rec;
 262
 263         rec.key = kbuf;
 264         rec.value = dbuf;
 265         rec.store = db_tdb_store_deny;
 266         rec.delete_rec = db_tdb_delete_deny;
 267         rec.private_data = ctx->db->private_data;
 268
 269         return ctx->f(&rec, ctx->private_data);
 270 }
 271
 272 static int db_tdb_traverse_read(struct db_context *db,
 273                            int (*f)(struct db_record *rec, void *private_data),
 274                            void *private_data)
 275 {
 276         struct db_tdb_ctx *db_ctx =
 277                 talloc_get_type_abort(db->private_data, struct db_tdb_ctx);
 278         struct db_tdb_traverse_ctx ctx;
 279
 280         ctx.db = db;
 281         ctx.f = f;
 282         ctx.private_data = private_data;
 283         return tdb_traverse_read(db_ctx->wtdb->tdb, db_tdb_traverse_read_func, &ctx);
 284 }
 285
 286 static int db_tdb_get_seqnum(struct db_context *db)
 287
 288 {
 289         struct db_tdb_ctx *db_ctx =
 290                 talloc_get_type_abort(db->private_data, struct db_tdb_ctx);
 291         return tdb_get_seqnum(db_ctx->wtdb->tdb);
 292 }
 293
 294 struct db_context *db_open_tdb(TALLOC_CTX *mem_ctx,
 295                                const char *name,
 296                                int hash_size, int tdb_flags,
 297                                int open_flags, mode_t mode)
 298 {
 299         struct db_context *result = NULL;
 300         struct db_tdb_ctx *db_tdb;
 301
 302         result = TALLOC_ZERO_P(mem_ctx, struct db_context);
 303         if (result == NULL) {
 304                 DEBUG(0, ("talloc failed\n"));
 305                 goto fail;
 306         }
 307
 308         result->private_data = db_tdb = TALLOC_P(result, struct db_tdb_ctx);
 309         if (db_tdb == NULL) {
 310                 DEBUG(0, ("talloc failed\n"));
 311                 goto fail;
 312         }
 313
 314         db_tdb->wtdb = tdb_wrap_open(db_tdb, name, hash_size, tdb_flags,
 315                                      open_flags, mode);
 316         if (db_tdb->wtdb == NULL) {
 317                 DEBUG(3, ("Could not open tdb: %s\n", strerror(errno)));
 318                 goto fail;
 319         }
 320
 321         result->fetch_locked = db_tdb_fetch_locked;
 322         result->fetch = db_tdb_fetch;
 323         result->traverse = db_tdb_traverse;
 324         result->traverse_read = db_tdb_traverse_read;
 325         result->get_seqnum = db_tdb_get_seqnum;
 326         result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
 327         return result;
 328
 329  fail:
 330         if (result != NULL) {
 331                 TALLOC_FREE(result);
 332         }
 333         return NULL;
 334 }