/* Unix SMB/CIFS implementation. Implementation of a reliable server_exists() Copyright (C) Volker Lendecke 2010 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 "serverid.h" struct serverid_key { pid_t pid; #ifdef CLUSTER_SUPPORT uint32_t vnn; #endif }; bool serverid_parent_init(void) { struct tdb_wrap *db; /* * Open the tdb in the parent process (smbd) so that our * CLEAR_IF_FIRST optimization in tdb_reopen_all can properly * work. */ db = tdb_wrap_open(talloc_autofree_context(), lock_path("serverid.tdb"), 0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST, O_RDWR|O_CREAT, 0644); if (db == NULL) { DEBUG(1, ("could not open serverid.tdb: %s\n", strerror(errno))); return false; } return true; } struct serverid_data { uint64_t unique_id; uint32_t msg_flags; }; static struct db_context *serverid_db(void) { static struct db_context *db; if (db != NULL) { return db; } db = db_open(talloc_autofree_context(), lock_path("serverid.tdb"), 0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST, O_RDWR|O_CREAT, 0644); return db; } static void serverid_fill_key(const struct server_id *id, struct serverid_key *key) { ZERO_STRUCTP(key); key->pid = id->pid; #ifdef CLUSTER_SUPPORT key->vnn = id->vnn; #endif } bool serverid_register(const struct server_id *id, uint32_t msg_flags) { struct db_context *db; struct serverid_key key; struct serverid_data data; struct db_record *rec; TDB_DATA tdbkey, tdbdata; NTSTATUS status; bool ret = false; db = serverid_db(); if (db == NULL) { return false; } serverid_fill_key(id, &key); tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key)); rec = db->fetch_locked(db, talloc_tos(), tdbkey); if (rec == NULL) { DEBUG(1, ("Could not fetch_lock serverid.tdb record\n")); return false; } ZERO_STRUCT(data); data.unique_id = id->unique_id; data.msg_flags = msg_flags; tdbdata = make_tdb_data((uint8_t *)&data, sizeof(data)); status = rec->store(rec, tdbdata, 0); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Storing serverid.tdb record failed: %s\n", nt_errstr(status))); goto done; } ret = true; done: TALLOC_FREE(rec); return ret; } bool serverid_register_self(uint32_t msg_flags) { struct server_id pid; pid = procid_self(); return serverid_register(&pid, msg_flags); } bool serverid_deregister(const struct server_id *id) { struct db_context *db; struct serverid_key key; struct db_record *rec; TDB_DATA tdbkey; NTSTATUS status; bool ret = false; db = serverid_db(); if (db == NULL) { return false; } serverid_fill_key(id, &key); tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key)); rec = db->fetch_locked(db, talloc_tos(), tdbkey); if (rec == NULL) { DEBUG(1, ("Could not fetch_lock serverid.tdb record\n")); return false; } status = rec->delete_rec(rec); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Deleting serverid.tdb record failed: %s\n", nt_errstr(status))); goto done; } ret = true; done: TALLOC_FREE(rec); return ret; } bool serverid_deregister_self(void) { struct server_id pid; pid = procid_self(); return serverid_deregister(&pid); } struct serverid_exists_state { const struct server_id *id; bool exists; }; static int server_exists_parse(TDB_DATA key, TDB_DATA data, void *priv) { struct serverid_exists_state *state = (struct serverid_exists_state *)priv; uint64_t unique_id; if (data.dsize != sizeof(struct serverid_data)) { return -1; } /* memcpy, data.dptr might not be aligned */ memcpy(&unique_id, data.dptr, sizeof(unique_id)); state->exists = (state->id->unique_id == unique_id); return 0; } bool serverid_exists(const struct server_id *id) { struct db_context *db; struct serverid_exists_state state; struct serverid_key key; TDB_DATA tdbkey; db = serverid_db(); if (db == NULL) { return false; } serverid_fill_key(id, &key); tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key)); state.id = id; state.exists = false; if (db->parse_record(db, tdbkey, server_exists_parse, &state) == -1) { return false; } return state.exists; } static bool serverid_rec_parse(const struct db_record *rec, struct server_id *id, uint32_t *msg_flags) { struct serverid_key key; struct serverid_data data; if (rec->key.dsize != sizeof(key)) { DEBUG(1, ("Found invalid key length %d in serverid.tdb\n", (int)rec->key.dsize)); return false; } if (rec->value.dsize != sizeof(data)) { DEBUG(1, ("Found invalid value length %d in serverid.tdb\n", (int)rec->value.dsize)); return false; } memcpy(&key, rec->key.dptr, sizeof(key)); memcpy(&data, rec->value.dptr, sizeof(data)); id->pid = key.pid; #ifdef CLUSTER_SUPPORT id->vnn = key.vnn; #endif id->unique_id = data.unique_id; *msg_flags = data.msg_flags; return true; } struct serverid_traverse_read_state { int (*fn)(const struct server_id *id, uint32_t msg_flags, void *private_data); void *private_data; }; static int serverid_traverse_read_fn(struct db_record *rec, void *private_data) { struct serverid_traverse_read_state *state = (struct serverid_traverse_read_state *)private_data; struct server_id id; uint32_t msg_flags; if (!serverid_rec_parse(rec, &id, &msg_flags)) { return 0; } return state->fn(&id, msg_flags,state->private_data); } bool serverid_traverse_read(int (*fn)(const struct server_id *id, uint32_t msg_flags, void *private_data), void *private_data) { struct db_context *db; struct serverid_traverse_read_state state; db = serverid_db(); if (db == NULL) { return false; } state.fn = fn; state.private_data = private_data; return db->traverse_read(db, serverid_traverse_read_fn, &state); } struct serverid_traverse_state { int (*fn)(struct db_record *rec, const struct server_id *id, uint32_t msg_flags, void *private_data); void *private_data; }; static int serverid_traverse_fn(struct db_record *rec, void *private_data) { struct serverid_traverse_state *state = (struct serverid_traverse_state *)private_data; struct server_id id; uint32_t msg_flags; if (!serverid_rec_parse(rec, &id, &msg_flags)) { return 0; } return state->fn(rec, &id, msg_flags, state->private_data); } bool serverid_traverse(int (*fn)(struct db_record *rec, const struct server_id *id, uint32_t msg_flags, void *private_data), void *private_data) { struct db_context *db; struct serverid_traverse_state state; db = serverid_db(); if (db == NULL) { return false; } state.fn = fn; state.private_data = private_data; return db->traverse(db, serverid_traverse_fn, &state); }