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Diffstat (limited to '')
-rw-r--r-- | lib/dbwrap/dbwrap.c | 736 |
1 files changed, 736 insertions, 0 deletions
diff --git a/lib/dbwrap/dbwrap.c b/lib/dbwrap/dbwrap.c new file mode 100644 index 0000000..19f6c29 --- /dev/null +++ b/lib/dbwrap/dbwrap.c @@ -0,0 +1,736 @@ +/* + Unix SMB/CIFS implementation. + Database interface wrapper + Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2006 + + Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com) + + 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 3 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, see <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#include "lib/util/debug.h" +#include "lib/util/fault.h" +#include "lib/util/talloc_stack.h" +#include "dbwrap/dbwrap.h" +#include "dbwrap/dbwrap_private.h" +#include "lib/util/util_tdb.h" +#include "lib/util/tevent_ntstatus.h" + +/* + * Fall back using fetch if no genuine exists operation is provided + */ + +static int dbwrap_fallback_exists(struct db_context *db, TDB_DATA key) +{ + NTSTATUS status = dbwrap_parse_record(db, key, NULL, NULL); + return NT_STATUS_IS_OK(status) ? 1 : 0; +} + +static int delete_record(struct db_record *rec, void *data) +{ + NTSTATUS status = dbwrap_record_delete(rec); + return NT_STATUS_IS_OK(status) ? 0 : -1; +} + +/* + * Fallback wipe implementation using traverse and delete if no genuine + * wipe operation is provided + */ +static int dbwrap_fallback_wipe(struct db_context *db) +{ + NTSTATUS status = dbwrap_trans_traverse(db, delete_record, NULL); + return NT_STATUS_IS_OK(status) ? 0 : -1; +} + +static int do_nothing(struct db_record *rec, void *unused) +{ + return 0; +} + +/* + * Fallback check operation: just traverse. + */ +static int dbwrap_fallback_check(struct db_context *db) +{ + NTSTATUS status = dbwrap_traverse_read(db, do_nothing, NULL, NULL); + return NT_STATUS_IS_OK(status) ? 0 : -1; +} + +/* + * Wrapper functions for the backend methods + */ + +TDB_DATA dbwrap_record_get_key(const struct db_record *rec) +{ + return rec->key; +} + +TDB_DATA dbwrap_record_get_value(const struct db_record *rec) +{ + SMB_ASSERT(rec->value_valid); + return rec->value; +} + +NTSTATUS dbwrap_record_storev(struct db_record *rec, + const TDB_DATA *dbufs, int num_dbufs, int flags) +{ + NTSTATUS status; + + /* + * Invalidate before rec->storev() is called, give + * rec->storev() the chance to re-validate rec->value. + */ + rec->value_valid = false; + + status = rec->storev(rec, dbufs, num_dbufs, flags); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + return NT_STATUS_OK; +} + +NTSTATUS dbwrap_record_store(struct db_record *rec, TDB_DATA data, int flags) +{ + return dbwrap_record_storev(rec, &data, 1, flags); +} + +NTSTATUS dbwrap_record_delete(struct db_record *rec) +{ + NTSTATUS status; + + status = rec->delete_rec(rec); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + rec->value = tdb_null; + + return NT_STATUS_OK; +} + +struct dbwrap_merge_dbs_state { + struct db_context *to; + int flags; +}; + +/* Copy a single record to the db_context passed in private_data */ +static int dbwrap_merge_dbs_copy_record(struct db_record *rec, + void *private_data) +{ + struct dbwrap_merge_dbs_state *state = private_data; + + TDB_DATA data = dbwrap_record_get_value(rec); + TDB_DATA key = dbwrap_record_get_key(rec); + NTSTATUS status = dbwrap_store(state->to, key, data, state->flags); + + return NT_STATUS_IS_OK(status) ? 0 : 1; +} + +NTSTATUS +dbwrap_merge_dbs(struct db_context *to, struct db_context *from, int flags) +{ + struct dbwrap_merge_dbs_state state = {.to = to, .flags = flags}; + + return dbwrap_traverse(from, + dbwrap_merge_dbs_copy_record, + &state, + NULL); +} + +const char *locked_dbs[DBWRAP_LOCK_ORDER_MAX]; + +static void debug_lock_order(int level) +{ + int i; + DEBUG(level, ("lock order:")); + for (i=0; i<DBWRAP_LOCK_ORDER_MAX; i++) { + DEBUGADD(level, + (" %d:%s", + i + 1, + locked_dbs[i] ? locked_dbs[i] : "<none>")); + } + DEBUGADD(level, ("\n")); +} + +void dbwrap_lock_order_lock(const char *db_name, + enum dbwrap_lock_order lock_order) +{ + int idx; + + DBG_INFO("check lock order %d for %s\n", + (int)lock_order, + db_name); + + if (!DBWRAP_LOCK_ORDER_VALID(lock_order)) { + DBG_ERR("Invalid lock order %d of %s\n", + lock_order, + db_name); + smb_panic("lock order violation"); + } + + for (idx=lock_order-1; idx<DBWRAP_LOCK_ORDER_MAX; idx++) { + if (locked_dbs[idx] != NULL) { + DBG_ERR("Lock order violation: Trying %s at %d while " + "%s at %d is locked\n", + db_name, + (int)lock_order, + locked_dbs[idx], + idx + 1); + debug_lock_order(0); + smb_panic("lock order violation"); + } + } + + locked_dbs[lock_order-1] = db_name; + + debug_lock_order(10); +} + +void dbwrap_lock_order_unlock(const char *db_name, + enum dbwrap_lock_order lock_order) +{ + DBG_INFO("release lock order %d for %s\n", + (int)lock_order, + db_name); + + if (!DBWRAP_LOCK_ORDER_VALID(lock_order)) { + DBG_ERR("Invalid lock order %d of %s\n", + lock_order, + db_name); + smb_panic("lock order violation"); + } + + if (locked_dbs[lock_order-1] == NULL) { + DBG_ERR("db %s at order %d unlocked\n", + db_name, + (int)lock_order); + smb_panic("lock order violation"); + } + + if (locked_dbs[lock_order-1] != db_name) { + DBG_ERR("locked db at lock order %d is %s, expected %s\n", + (int)lock_order, + locked_dbs[lock_order-1], + db_name); + smb_panic("lock order violation"); + } + + locked_dbs[lock_order-1] = NULL; +} + +struct dbwrap_lock_order_state { + struct db_context *db; +}; + +static int dbwrap_lock_order_state_destructor( + struct dbwrap_lock_order_state *s) +{ + struct db_context *db = s->db; + dbwrap_lock_order_unlock(db->name, db->lock_order); + return 0; +} + +static struct dbwrap_lock_order_state *dbwrap_check_lock_order( + struct db_context *db, TALLOC_CTX *mem_ctx) +{ + struct dbwrap_lock_order_state *state; + + state = talloc(mem_ctx, struct dbwrap_lock_order_state); + if (state == NULL) { + DBG_WARNING("talloc failed\n"); + return NULL; + } + state->db = db; + + dbwrap_lock_order_lock(db->name, db->lock_order); + talloc_set_destructor(state, dbwrap_lock_order_state_destructor); + + return state; +} + +static struct db_record *dbwrap_fetch_locked_internal( + struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key, + struct db_record *(*db_fn)(struct db_context *db, TALLOC_CTX *mem_ctx, + TDB_DATA key)) +{ + struct db_record *rec; + struct dbwrap_lock_order_state *lock_order = NULL; + + if (db->lock_order != DBWRAP_LOCK_ORDER_NONE) { + lock_order = dbwrap_check_lock_order(db, mem_ctx); + if (lock_order == NULL) { + return NULL; + } + } + rec = db_fn(db, mem_ctx, key); + if (rec == NULL) { + TALLOC_FREE(lock_order); + return NULL; + } + (void)talloc_steal(rec, lock_order); + rec->db = db; + return rec; +} + +struct db_record *dbwrap_fetch_locked(struct db_context *db, + TALLOC_CTX *mem_ctx, + TDB_DATA key) +{ + return dbwrap_fetch_locked_internal(db, mem_ctx, key, + db->fetch_locked); +} + +struct db_context *dbwrap_record_get_db(struct db_record *rec) +{ + return rec->db; +} + +struct dbwrap_fetch_state { + TALLOC_CTX *mem_ctx; + TDB_DATA data; +}; + +static void dbwrap_fetch_parser(TDB_DATA key, TDB_DATA data, + void *private_data) +{ + struct dbwrap_fetch_state *state = + (struct dbwrap_fetch_state *)private_data; + + state->data.dsize = data.dsize; + state->data.dptr = (uint8_t *)talloc_memdup(state->mem_ctx, data.dptr, + data.dsize); +} + +NTSTATUS dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx, + TDB_DATA key, TDB_DATA *value) +{ + struct dbwrap_fetch_state state; + NTSTATUS status; + + if (value == NULL) { + return NT_STATUS_INVALID_PARAMETER; + } + + state.mem_ctx = mem_ctx; + + status = dbwrap_parse_record(db, key, dbwrap_fetch_parser, &state); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + if ((state.data.dsize != 0) && (state.data.dptr == NULL)) { + return NT_STATUS_NO_MEMORY; + } + *value = state.data; + return NT_STATUS_OK; +} + +bool dbwrap_exists(struct db_context *db, TDB_DATA key) +{ + int result; + if (db->exists != NULL) { + result = db->exists(db, key); + } else { + result = dbwrap_fallback_exists(db,key); + } + return (result == 1); +} + +struct dbwrap_store_state { + TDB_DATA data; + int flags; + NTSTATUS status; +}; + +static void dbwrap_store_fn( + struct db_record *rec, + TDB_DATA value, + void *private_data) +{ + struct dbwrap_store_state *state = private_data; + state->status = dbwrap_record_store(rec, state->data, state->flags); +} + +NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key, + TDB_DATA data, int flags) +{ + struct dbwrap_store_state state = { .data = data, .flags = flags }; + NTSTATUS status; + + status = dbwrap_do_locked(db, key, dbwrap_store_fn, &state); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + return state.status; +} + +struct dbwrap_delete_state { + NTSTATUS status; +}; + +static void dbwrap_delete_fn( + struct db_record *rec, + TDB_DATA value, + void *private_data) +{ + struct dbwrap_delete_state *state = private_data; + state->status = dbwrap_record_delete(rec); +} + +NTSTATUS dbwrap_delete(struct db_context *db, TDB_DATA key) +{ + struct dbwrap_delete_state state = { .status = NT_STATUS_NOT_FOUND }; + NTSTATUS status; + + status = dbwrap_do_locked(db, key, dbwrap_delete_fn, &state); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + return state.status; +} + +NTSTATUS dbwrap_traverse(struct db_context *db, + int (*f)(struct db_record*, void*), + void *private_data, + int *count) +{ + int ret = db->traverse(db, f, private_data); + + if (ret < 0) { + return NT_STATUS_INTERNAL_DB_CORRUPTION; + } + + if (count != NULL) { + *count = ret; + } + + return NT_STATUS_OK; +} + +NTSTATUS dbwrap_traverse_read(struct db_context *db, + int (*f)(struct db_record*, void*), + void *private_data, + int *count) +{ + int ret = db->traverse_read(db, f, private_data); + + if (ret < 0) { + return NT_STATUS_INTERNAL_DB_CORRUPTION; + } + + if (count != NULL) { + *count = ret; + } + + return NT_STATUS_OK; +} + +static void dbwrap_null_parser(TDB_DATA key, TDB_DATA val, void* data) +{ + return; +} + +NTSTATUS dbwrap_parse_record(struct db_context *db, TDB_DATA key, + void (*parser)(TDB_DATA key, TDB_DATA data, + void *private_data), + void *private_data) +{ + if (parser == NULL) { + parser = dbwrap_null_parser; + } + return db->parse_record(db, key, parser, private_data); +} + +struct dbwrap_parse_record_state { + struct db_context *db; + TDB_DATA key; + uint8_t _keybuf[64]; +}; + +static void dbwrap_parse_record_done(struct tevent_req *subreq); + +struct tevent_req *dbwrap_parse_record_send( + TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct db_context *db, + TDB_DATA key, + void (*parser)(TDB_DATA key, TDB_DATA data, void *private_data), + void *private_data, + enum dbwrap_req_state *req_state) +{ + struct tevent_req *req = NULL; + struct tevent_req *subreq = NULL; + struct dbwrap_parse_record_state *state = NULL; + NTSTATUS status; + + req = tevent_req_create(mem_ctx, &state, struct dbwrap_parse_record_state); + if (req == NULL) { + *req_state = DBWRAP_REQ_ERROR; + return NULL; + } + + *state = (struct dbwrap_parse_record_state) { + .db = db, + }; + + if (parser == NULL) { + parser = dbwrap_null_parser; + } + + *req_state = DBWRAP_REQ_INIT; + + if (db->parse_record_send == NULL) { + /* + * Backend doesn't implement async version, call sync one + */ + status = db->parse_record(db, key, parser, private_data); + if (tevent_req_nterror(req, status)) { + *req_state = DBWRAP_REQ_DONE; + return tevent_req_post(req, ev); + } + + *req_state = DBWRAP_REQ_DONE; + tevent_req_done(req); + return tevent_req_post(req, ev); + } + + /* + * Copy the key into our state ensuring the key data buffer is always + * available to all the dbwrap backends over the entire lifetime of the + * async request. Otherwise the caller might have free'd the key buffer. + */ + if (key.dsize > sizeof(state->_keybuf)) { + state->key.dptr = talloc_memdup(state, key.dptr, key.dsize); + if (tevent_req_nomem(state->key.dptr, req)) { + return tevent_req_post(req, ev); + } + } else { + memcpy(state->_keybuf, key.dptr, key.dsize); + state->key.dptr = state->_keybuf; + } + state->key.dsize = key.dsize; + + subreq = db->parse_record_send(state, + ev, + db, + state->key, + parser, + private_data, + req_state); + if (tevent_req_nomem(subreq, req)) { + *req_state = DBWRAP_REQ_ERROR; + return tevent_req_post(req, ev); + } + + tevent_req_set_callback(subreq, + dbwrap_parse_record_done, + req); + return req; +} + +static void dbwrap_parse_record_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data( + subreq, struct tevent_req); + struct dbwrap_parse_record_state *state = tevent_req_data( + req, struct dbwrap_parse_record_state); + NTSTATUS status; + + status = state->db->parse_record_recv(subreq); + TALLOC_FREE(subreq); + if (!NT_STATUS_IS_OK(status)) { + tevent_req_nterror(req, status); + return; + } + + tevent_req_done(req); +} + +NTSTATUS dbwrap_parse_record_recv(struct tevent_req *req) +{ + return tevent_req_simple_recv_ntstatus(req); +} + +NTSTATUS dbwrap_do_locked(struct db_context *db, TDB_DATA key, + void (*fn)(struct db_record *rec, + TDB_DATA value, + void *private_data), + void *private_data) +{ + struct db_record *rec; + + if (db->do_locked != NULL) { + NTSTATUS status; + + if (db->lock_order != DBWRAP_LOCK_ORDER_NONE) { + dbwrap_lock_order_lock(db->name, db->lock_order); + } + + status = db->do_locked(db, key, fn, private_data); + + if (db->lock_order != DBWRAP_LOCK_ORDER_NONE) { + dbwrap_lock_order_unlock(db->name, db->lock_order); + } + + return status; + } + + rec = dbwrap_fetch_locked(db, db, key); + if (rec == NULL) { + return NT_STATUS_NO_MEMORY; + } + + /* + * Invalidate rec->value, nobody shall assume it's set from + * within dbwrap_do_locked(). + */ + rec->value_valid = false; + + fn(rec, rec->value, private_data); + + TALLOC_FREE(rec); + + return NT_STATUS_OK; +} + +int dbwrap_wipe(struct db_context *db) +{ + if (db->wipe == NULL) { + return dbwrap_fallback_wipe(db); + } + return db->wipe(db); +} + +int dbwrap_check(struct db_context *db) +{ + if (db->check == NULL) { + return dbwrap_fallback_check(db); + } + return db->check(db); +} + +int dbwrap_get_seqnum(struct db_context *db) +{ + return db->get_seqnum(db); +} + +int dbwrap_transaction_start(struct db_context *db) +{ + if (!db->persistent) { + /* + * dbwrap_ctdb has two different data models for persistent + * and non-persistent databases. Transactions are supported + * only for the persistent databases. This check is here to + * prevent breakages of the cluster case, autobuild at this + * point only tests non-clustered Samba. Before removing this + * check, please make sure that this facility has also been + * added to dbwrap_ctdb. + * + * Thanks, vl + */ + DEBUG(1, ("transactions not supported on non-persistent " + "database %s\n", db->name)); + return -1; + } + return db->transaction_start(db); +} + +NTSTATUS dbwrap_transaction_start_nonblock(struct db_context *db) +{ + if (db->transaction_start_nonblock) { + return db->transaction_start_nonblock(db); + } else { + return dbwrap_transaction_start(db) == 0 ? NT_STATUS_OK + : NT_STATUS_UNSUCCESSFUL; + } +} + +int dbwrap_transaction_commit(struct db_context *db) +{ + return db->transaction_commit(db); +} + +int dbwrap_transaction_cancel(struct db_context *db) +{ + return db->transaction_cancel(db); +} + +size_t dbwrap_db_id(struct db_context *db, uint8_t *id, size_t idlen) +{ + return db->id(db, id, idlen); +} + +bool dbwrap_is_persistent(struct db_context *db) +{ + return db->persistent; +} + +const char *dbwrap_name(struct db_context *db) +{ + return db->name; +} + +static ssize_t tdb_data_buf(const TDB_DATA *dbufs, int num_dbufs, + uint8_t *buf, size_t buflen) +{ + size_t needed = 0; + uint8_t *p = buf; + int i; + + for (i=0; i<num_dbufs; i++) { + size_t thislen = dbufs[i].dsize; + + needed += thislen; + if (needed < thislen) { + /* wrap */ + return -1; + } + + if (p != NULL && (thislen != 0) && (needed <= buflen)) { + memcpy(p, dbufs[i].dptr, thislen); + p += thislen; + } + } + + return needed; +} + + +NTSTATUS dbwrap_merge_dbufs(TDB_DATA *buf, TALLOC_CTX *mem_ctx, + const TDB_DATA *dbufs, int num_dbufs) +{ + ssize_t len = tdb_data_buf(dbufs, num_dbufs, NULL, 0); + + if (len == -1) { + return NT_STATUS_INVALID_PARAMETER; + } + + if (buf->dsize != len) { + uint8_t *tmp; + + tmp = talloc_realloc(mem_ctx, buf->dptr, uint8_t, len); + if (tmp == NULL && len != 0) { + return NT_STATUS_NO_MEMORY; + } + + buf->dptr = tmp; + buf->dsize = len; + } + + tdb_data_buf(dbufs, num_dbufs, buf->dptr, buf->dsize); + + return NT_STATUS_OK; +} |