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Diffstat (limited to '')
-rw-r--r-- | source3/lib/server_mutex.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/source3/lib/server_mutex.c b/source3/lib/server_mutex.c new file mode 100644 index 0000000..cbb8357 --- /dev/null +++ b/source3/lib/server_mutex.c @@ -0,0 +1,104 @@ +/* + Unix SMB/CIFS implementation. + Authenticate against a remote domain + Copyright (C) Andrew Tridgell 1992-2002 + Copyright (C) Andrew Bartlett 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 + 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 "lib/tdb_wrap/tdb_wrap.h" +#include "util_tdb.h" +#include "lib/param/param.h" + +/* For reasons known only to MS, many of their NT/Win2k versions + need serialised access only. Two connections at the same time + may (in certain situations) cause connections to be reset, + or access to be denied. + + This locking allows smbd's multithread architecture to look + like the single-connection that NT makes. */ + +struct named_mutex { + struct tdb_wrap *tdb; + char *name; +}; + +static int unlock_named_mutex(struct named_mutex *mutex) +{ + tdb_unlock_bystring(mutex->tdb->tdb, mutex->name); + return 0; +} + +struct named_mutex *grab_named_mutex(TALLOC_CTX *mem_ctx, const char *name, + int timeout) +{ + struct named_mutex *result; + struct loadparm_context *lp_ctx; + char *fname; + + result = talloc(mem_ctx, struct named_mutex); + if (result == NULL) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + lp_ctx = loadparm_init_s3(result, loadparm_s3_helpers()); + if (lp_ctx == NULL) { + DEBUG(0, ("loadparm_init_s3 failed\n")); + talloc_free(result); + return NULL; + } + + result->name = talloc_strdup(result, name); + if (result->name == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + fname = lock_path(talloc_tos(), "mutex.tdb"); + if (fname == NULL) { + TALLOC_FREE(result); + return NULL; + } + + result->tdb = tdb_wrap_open(result, fname, + lpcfg_tdb_hash_size(lp_ctx, fname), + lpcfg_tdb_flags(lp_ctx, + TDB_DEFAULT | + TDB_CLEAR_IF_FIRST | + TDB_INCOMPATIBLE_HASH), + O_RDWR|O_CREAT, 0600); + TALLOC_FREE(fname); + talloc_unlink(result, lp_ctx); + if (result->tdb == NULL) { + DEBUG(1, ("Could not open mutex.tdb: %s\n", + strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + if (tdb_lock_bystring_with_timeout(result->tdb->tdb, name, + timeout) != 0) { + DEBUG(1, ("Could not get the lock for %s\n", name)); + TALLOC_FREE(result); + return NULL; + } + + talloc_set_destructor(result, unlock_named_mutex); + return result; +} |