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samba-mirror/source3/lib/dbwrap/dbwrap_watch.c
Christof Schmitt b041a589ae Remove function name from callers of DBG_*
It is now added automatically.

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2015-10-21 23:13:17 +02:00

482 lines
12 KiB
C

/*
Unix SMB/CIFS implementation.
Watch dbwrap record changes
Copyright (C) Volker Lendecke 2012
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 "includes.h"
#include "system/filesys.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap_watch.h"
#include "dbwrap_open.h"
#include "lib/util/util_tdb.h"
#include "lib/util/tevent_ntstatus.h"
static struct db_context *dbwrap_record_watchers_db(void)
{
static struct db_context *watchers_db;
if (watchers_db == NULL) {
char *db_path = lock_path("dbwrap_watchers.tdb");
if (db_path == NULL) {
return NULL;
}
watchers_db = db_open(
NULL, db_path, 0,
TDB_CLEAR_IF_FIRST | TDB_INCOMPATIBLE_HASH,
O_RDWR|O_CREAT, 0600, DBWRAP_LOCK_ORDER_3,
DBWRAP_FLAG_NONE);
TALLOC_FREE(db_path);
}
return watchers_db;
}
static size_t dbwrap_record_watchers_key(struct db_context *db,
struct db_record *rec,
uint8_t *wkey, size_t wkey_len)
{
size_t db_id_len = dbwrap_db_id(db, NULL, 0);
uint8_t db_id[db_id_len];
size_t needed;
TDB_DATA key;
dbwrap_db_id(db, db_id, db_id_len);
key = dbwrap_record_get_key(rec);
needed = sizeof(uint32_t) + db_id_len + key.dsize;
if (wkey_len >= needed) {
SIVAL(wkey, 0, db_id_len);
memcpy(wkey + sizeof(uint32_t), db_id, db_id_len);
memcpy(wkey + sizeof(uint32_t) + db_id_len,
key.dptr, key.dsize);
}
return needed;
}
static bool dbwrap_record_watchers_key_parse(
TDB_DATA wkey, uint8_t **p_db_id, size_t *p_db_id_len, TDB_DATA *key)
{
size_t db_id_len;
if (wkey.dsize < sizeof(uint32_t)) {
DEBUG(1, ("Invalid watchers key\n"));
return false;
}
db_id_len = IVAL(wkey.dptr, 0);
if (db_id_len > (wkey.dsize - sizeof(uint32_t))) {
DEBUG(1, ("Invalid watchers key, wkey.dsize=%d, "
"db_id_len=%d\n", (int)wkey.dsize, (int)db_id_len));
return false;
}
if (p_db_id != NULL) {
*p_db_id = wkey.dptr + sizeof(uint32_t);
}
if (p_db_id_len != NULL) {
*p_db_id_len = db_id_len;
}
if (key != NULL) {
key->dptr = wkey.dptr + sizeof(uint32_t) + db_id_len;
key->dsize = wkey.dsize - sizeof(uint32_t) - db_id_len;
}
return true;
}
static NTSTATUS dbwrap_record_add_watcher(TDB_DATA w_key, struct server_id id)
{
struct TALLOC_CTX *frame = talloc_stackframe();
struct db_context *db;
struct db_record *rec;
TDB_DATA value;
struct server_id *ids;
size_t num_ids;
NTSTATUS status;
db = dbwrap_record_watchers_db();
if (db == NULL) {
status = map_nt_error_from_unix(errno);
goto fail;
}
rec = dbwrap_fetch_locked(db, talloc_tos(), w_key);
if (rec == NULL) {
status = map_nt_error_from_unix(errno);
goto fail;
}
value = dbwrap_record_get_value(rec);
if ((value.dsize % sizeof(struct server_id)) != 0) {
status = NT_STATUS_INTERNAL_DB_CORRUPTION;
goto fail;
}
ids = (struct server_id *)value.dptr;
num_ids = value.dsize / sizeof(struct server_id);
ids = talloc_array(talloc_tos(), struct server_id,
num_ids + 1);
if (ids == NULL) {
status = NT_STATUS_NO_MEMORY;
goto fail;
}
memcpy(ids, value.dptr, value.dsize);
ids[num_ids] = id;
num_ids += 1;
status = dbwrap_record_store(
rec, make_tdb_data((uint8_t *)ids, talloc_get_size(ids)), 0);
fail:
TALLOC_FREE(frame);
return status;
}
static NTSTATUS dbwrap_record_del_watcher(TDB_DATA w_key, struct server_id id)
{
struct TALLOC_CTX *frame = talloc_stackframe();
struct db_context *db;
struct db_record *rec;
struct server_id *ids;
size_t i, num_ids;
TDB_DATA value;
NTSTATUS status;
db = dbwrap_record_watchers_db();
if (db == NULL) {
status = map_nt_error_from_unix(errno);
goto fail;
}
rec = dbwrap_fetch_locked(db, talloc_tos(), w_key);
if (rec == NULL) {
status = map_nt_error_from_unix(errno);
goto fail;
}
value = dbwrap_record_get_value(rec);
if ((value.dsize % sizeof(struct server_id)) != 0) {
status = NT_STATUS_INTERNAL_DB_CORRUPTION;
goto fail;
}
ids = (struct server_id *)value.dptr;
num_ids = value.dsize / sizeof(struct server_id);
for (i=0; i<num_ids; i++) {
if (serverid_equal(&id, &ids[i])) {
ids[i] = ids[num_ids-1];
value.dsize -= sizeof(struct server_id);
break;
}
}
if (value.dsize == 0) {
status = dbwrap_record_delete(rec);
goto done;
}
status = dbwrap_record_store(rec, value, 0);
fail:
done:
TALLOC_FREE(frame);
return status;
}
struct dbwrap_record_watch_state {
struct tevent_context *ev;
struct db_context *db;
struct tevent_req *req;
struct messaging_context *msg;
TDB_DATA w_key;
};
static bool dbwrap_record_watch_filter(struct messaging_rec *rec,
void *private_data);
static void dbwrap_record_watch_done(struct tevent_req *subreq);
static int dbwrap_record_watch_state_destructor(
struct dbwrap_record_watch_state *state);
struct tevent_req *dbwrap_record_watch_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct db_record *rec,
struct messaging_context *msg)
{
struct tevent_req *req, *subreq;
struct dbwrap_record_watch_state *state;
struct db_context *watchers_db;
NTSTATUS status;
req = tevent_req_create(mem_ctx, &state,
struct dbwrap_record_watch_state);
if (req == NULL) {
return NULL;
}
state->db = dbwrap_record_get_db(rec);
state->ev = ev;
state->req = req;
state->msg = msg;
watchers_db = dbwrap_record_watchers_db();
if (watchers_db == NULL) {
tevent_req_nterror(req, map_nt_error_from_unix(errno));
return tevent_req_post(req, ev);
}
state->w_key.dsize = dbwrap_record_watchers_key(
state->db, rec, NULL, 0);
state->w_key.dptr = talloc_array(state, uint8_t, state->w_key.dsize);
if (tevent_req_nomem(state->w_key.dptr, req)) {
return tevent_req_post(req, ev);
}
dbwrap_record_watchers_key(
state->db, rec, state->w_key.dptr, state->w_key.dsize);
subreq = messaging_filtered_read_send(
state, ev, state->msg, dbwrap_record_watch_filter, state);
if (tevent_req_nomem(subreq, req)) {
return tevent_req_post(req, ev);
}
tevent_req_set_callback(subreq, dbwrap_record_watch_done, req);
status = dbwrap_record_add_watcher(
state->w_key, messaging_server_id(state->msg));
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
talloc_set_destructor(state, dbwrap_record_watch_state_destructor);
return req;
}
static bool dbwrap_record_watch_filter(struct messaging_rec *rec,
void *private_data)
{
struct dbwrap_record_watch_state *state = talloc_get_type_abort(
private_data, struct dbwrap_record_watch_state);
if (rec->msg_type != MSG_DBWRAP_MODIFIED) {
return false;
}
if (rec->num_fds != 0) {
return false;
}
if (rec->buf.length != state->w_key.dsize) {
return false;
}
return memcmp(rec->buf.data, state->w_key.dptr, rec->buf.length) == 0;
}
static int dbwrap_record_watch_state_destructor(
struct dbwrap_record_watch_state *s)
{
if (s->msg != NULL) {
dbwrap_record_del_watcher(
s->w_key, messaging_server_id(s->msg));
}
return 0;
}
static void dbwrap_watch_record_stored_fn(TDB_DATA key, TDB_DATA data,
void *private_data)
{
struct messaging_context *msg = private_data;
size_t i, num_ids;
if ((data.dsize % sizeof(struct server_id)) != 0) {
DBG_WARNING("Invalid data size: %zu\n", data.dsize);
return;
}
num_ids = data.dsize / sizeof(struct server_id);
for (i=0; i<num_ids; i++) {
struct server_id dst;
NTSTATUS status;
memcpy(&dst, data.dptr + i * sizeof(struct server_id),
sizeof(struct server_id));
status = messaging_send_buf(msg, dst, MSG_DBWRAP_MODIFIED,
key.dptr, key.dsize);
if (!NT_STATUS_IS_OK(status)) {
struct server_id_buf tmp;
DBG_WARNING("messaging_send to %s failed: %s\n",
server_id_str_buf(dst, &tmp),
nt_errstr(status));
}
}
}
static void dbwrap_watch_record_stored(struct db_context *db,
struct db_record *rec,
void *private_data)
{
struct messaging_context *msg = talloc_get_type_abort(
private_data, struct messaging_context);
struct db_context *watchers_db;
size_t wkey_len = dbwrap_record_watchers_key(db, rec, NULL, 0);
uint8_t wkey_buf[wkey_len];
TDB_DATA wkey = { .dptr = wkey_buf, .dsize = wkey_len };
NTSTATUS status;
watchers_db = dbwrap_record_watchers_db();
if (watchers_db == NULL) {
return;
}
dbwrap_record_watchers_key(db, rec, wkey_buf, wkey_len);
status = dbwrap_parse_record(watchers_db, wkey,
dbwrap_watch_record_stored_fn, msg);
if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
return;
}
if (!NT_STATUS_IS_OK(status)) {
DBG_WARNING("dbwrap_parse_record failed: %s\n",
nt_errstr(status));
}
}
void dbwrap_watch_db(struct db_context *db, struct messaging_context *msg)
{
dbwrap_set_stored_callback(db, dbwrap_watch_record_stored, msg);
}
static void dbwrap_record_watch_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(
subreq, struct tevent_req);
struct messaging_rec *rec;
int ret;
ret = messaging_filtered_read_recv(subreq, talloc_tos(), &rec);
TALLOC_FREE(subreq);
if (ret != 0) {
tevent_req_nterror(req, map_nt_error_from_unix(ret));
return;
}
tevent_req_done(req);
}
NTSTATUS dbwrap_record_watch_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx,
struct db_record **prec)
{
struct dbwrap_record_watch_state *state = tevent_req_data(
req, struct dbwrap_record_watch_state);
NTSTATUS status;
TDB_DATA key;
struct db_record *rec;
bool ok;
if (tevent_req_is_nterror(req, &status)) {
return status;
}
if (prec == NULL) {
return NT_STATUS_OK;
}
ok = dbwrap_record_watchers_key_parse(state->w_key, NULL, NULL, &key);
if (!ok) {
return NT_STATUS_INTERNAL_DB_ERROR;
}
rec = dbwrap_fetch_locked(state->db, mem_ctx, key);
if (rec == NULL) {
return NT_STATUS_INTERNAL_DB_ERROR;
}
*prec = rec;
return NT_STATUS_OK;
}
struct dbwrap_watchers_traverse_read_state {
int (*fn)(const uint8_t *db_id, size_t db_id_len, const TDB_DATA key,
const struct server_id *watchers, size_t num_watchers,
void *private_data);
void *private_data;
};
static int dbwrap_watchers_traverse_read_callback(
struct db_record *rec, void *private_data)
{
struct dbwrap_watchers_traverse_read_state *state =
(struct dbwrap_watchers_traverse_read_state *)private_data;
uint8_t *db_id;
size_t db_id_len;
TDB_DATA w_key, key, w_data;
int res;
w_key = dbwrap_record_get_key(rec);
w_data = dbwrap_record_get_value(rec);
if (!dbwrap_record_watchers_key_parse(w_key, &db_id, &db_id_len,
&key)) {
return 0;
}
if ((w_data.dsize % sizeof(struct server_id)) != 0) {
return 0;
}
res = state->fn(db_id, db_id_len, key,
(struct server_id *)w_data.dptr,
w_data.dsize / sizeof(struct server_id),
state->private_data);
return res;
}
void dbwrap_watchers_traverse_read(
int (*fn)(const uint8_t *db_id, size_t db_id_len, const TDB_DATA key,
const struct server_id *watchers, size_t num_watchers,
void *private_data),
void *private_data)
{
struct dbwrap_watchers_traverse_read_state state;
struct db_context *db;
db = dbwrap_record_watchers_db();
if (db == NULL) {
return;
}
state.fn = fn;
state.private_data = private_data;
dbwrap_traverse_read(db, dbwrap_watchers_traverse_read_callback,
&state, NULL);
}
static int dbwrap_wakeall_cb(const uint8_t *db_id, size_t db_id_len,
const TDB_DATA key,
const struct server_id *watchers,
size_t num_watchers,
void *private_data)
{
struct messaging_context *msg = talloc_get_type_abort(
private_data, struct messaging_context);
uint32_t i;
DATA_BLOB blob;
blob.data = key.dptr;
blob.length = key.dsize;
for (i=0; i<num_watchers; i++) {
messaging_send(msg, watchers[i], MSG_DBWRAP_MODIFIED, &blob);
}
return 0;
}
void dbwrap_watchers_wakeall(struct messaging_context *msg)
{
dbwrap_watchers_traverse_read(dbwrap_wakeall_cb, msg);
}