/* Unix SMB/CIFS implementation. Locking functions Copyright (C) Andrew Tridgell 1992-2000 Copyright (C) Jeremy Allison 1992-2006 Copyright (C) Volker Lendecke 2005 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 . Revision History: 12 aug 96: Erik.Devriendt@te6.siemens.be added support for shared memory implementation of share mode locking May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode locking to deal with multiple share modes per open file. September 1997. Jeremy Allison (jallison@whistle.com). Added oplock support. rewritten completely to use new tdb code. Tridge, Dec '99 Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000. Added Unix Extensions POSIX locking support. Jeremy Allison Mar 2006. */ #include "includes.h" #include "lib/util/time_basic.h" #include "system/filesys.h" #include "lib/util/server_id.h" #include "share_mode_lock_private.h" struct share_mode_lock { struct file_id id; struct share_mode_data *cached_data; }; #define SHARE_MODE_ENTRY_PREPARE_STATE_LCK_SPACE 1 #include "share_mode_lock.h" #include "locking/proto.h" #include "smbd/globals.h" #include "dbwrap/dbwrap.h" #include "dbwrap/dbwrap_open.h" #include "dbwrap/dbwrap_private.h" #include "../libcli/security/security.h" #include "serverid.h" #include "messages.h" #include "util_tdb.h" #include "../librpc/gen_ndr/ndr_open_files.h" #include "source3/lib/dbwrap/dbwrap_watch.h" #include "locking/leases_db.h" #include "../lib/util/memcache.h" #include "lib/util/tevent_ntstatus.h" #include "g_lock.h" #include "smbd/fd_handle.h" #include "lib/global_contexts.h" #undef DBGC_CLASS #define DBGC_CLASS DBGC_LOCKING #define DBG_GET_SHARE_MODE_LOCK(__status, ...) \ DBG_PREFIX( \ NT_STATUS_EQUAL(__status, NT_STATUS_NOT_FOUND) ? \ DBGLVL_DEBUG : DBGLVL_ERR, \ (__VA_ARGS__)) /* the locking database handle */ static struct g_lock_ctx *lock_ctx; static struct g_lock_lock_cb_state *current_share_mode_glck = NULL; static bool share_mode_g_lock_within_cb(TDB_DATA key); static NTSTATUS share_mode_g_lock_dump(TDB_DATA key, void (*fn)(struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data), void *private_data) { if (share_mode_g_lock_within_cb(key)) { return g_lock_lock_cb_dump(current_share_mode_glck, fn, private_data); } return g_lock_dump(lock_ctx, key, fn, private_data); } static NTSTATUS share_mode_g_lock_writev(TDB_DATA key, const TDB_DATA *dbufs, size_t num_dbufs) { if (share_mode_g_lock_within_cb(key)) { return g_lock_lock_cb_writev(current_share_mode_glck, dbufs, num_dbufs); } return g_lock_writev_data(lock_ctx, key, dbufs, num_dbufs); } static bool locking_init_internal(bool read_only) { struct db_context *backend; char *db_path; brl_init(read_only); if (lock_ctx != NULL) { return True; } db_path = lock_path(talloc_tos(), "locking.tdb"); if (db_path == NULL) { return false; } backend = db_open(NULL, db_path, SMBD_VOLATILE_TDB_HASH_SIZE, SMBD_VOLATILE_TDB_FLAGS | TDB_SEQNUM, read_only?O_RDONLY:O_RDWR|O_CREAT, 0644, DBWRAP_LOCK_ORDER_NONE, DBWRAP_FLAG_NONE); TALLOC_FREE(db_path); if (!backend) { DEBUG(0,("ERROR: Failed to initialise locking database\n")); return False; } lock_ctx = g_lock_ctx_init_backend( NULL, global_messaging_context(), &backend); if (lock_ctx == NULL) { TALLOC_FREE(backend); return false; } g_lock_set_lock_order(lock_ctx, DBWRAP_LOCK_ORDER_1); if (!posix_locking_init(read_only)) { TALLOC_FREE(lock_ctx); return False; } return True; } bool locking_init(void) { return locking_init_internal(false); } bool locking_init_readonly(void) { return locking_init_internal(true); } /******************************************************************* Deinitialize the share_mode management. ******************************************************************/ bool locking_end(void) { brl_shutdown(); TALLOC_FREE(lock_ctx); return true; } /******************************************************************* Form a static locking key for a dev/inode pair. ******************************************************************/ static TDB_DATA locking_key(const struct file_id *id) { return make_tdb_data((const uint8_t *)id, sizeof(*id)); } /******************************************************************* Share mode cache utility functions that store/delete/retrieve entries from memcache. For now share the statcache (global cache) memory space. If a lock record gets orphaned (which shouldn't happen as we're using the same locking_key data as lookup) it will eventually fall out of the cache via the normal LRU trim mechanism. If necessary we can always make this a separate (smaller) cache. ******************************************************************/ static DATA_BLOB memcache_key(const struct file_id *id) { return data_blob_const((const void *)id, sizeof(*id)); } static void share_mode_memcache_store(struct share_mode_data *d) { const DATA_BLOB key = memcache_key(&d->id); struct file_id_buf idbuf; DBG_DEBUG("stored entry for file %s epoch %"PRIx64" key %s\n", d->base_name, d->unique_content_epoch, file_id_str_buf(d->id, &idbuf)); /* Ensure everything stored in the cache is pristine. */ SMB_ASSERT(!d->modified); SMB_ASSERT(!d->not_stored); /* * Ensure the memory going into the cache * doesn't have a destructor so it can be * cleanly evicted by the memcache LRU * mechanism. */ talloc_set_destructor(d, NULL); /* Cache will own d after this call. */ memcache_add_talloc(NULL, SHARE_MODE_LOCK_CACHE, key, &d); } /* * NB. We use ndr_pull_hyper on a stack-created * struct ndr_pull with no talloc allowed, as we * need this to be really fast as an ndr-peek into * the first 10 bytes of the blob. */ static enum ndr_err_code get_share_mode_blob_header( const uint8_t *buf, size_t buflen, uint64_t *pepoch, uint16_t *pflags) { struct ndr_pull ndr = { .data = discard_const_p(uint8_t, buf), .data_size = buflen, }; NDR_CHECK(ndr_pull_hyper(&ndr, NDR_SCALARS, pepoch)); NDR_CHECK(ndr_pull_uint16(&ndr, NDR_SCALARS, pflags)); return NDR_ERR_SUCCESS; } static int share_mode_data_nofree_destructor(struct share_mode_data *d) { return -1; } static struct share_mode_data *share_mode_memcache_fetch( TALLOC_CTX *mem_ctx, struct file_id id, const uint8_t *buf, size_t buflen) { const DATA_BLOB key = memcache_key(&id); enum ndr_err_code ndr_err; struct share_mode_data *d; uint64_t unique_content_epoch; uint16_t flags; void *ptr; struct file_id_buf idbuf; ptr = memcache_lookup_talloc(NULL, SHARE_MODE_LOCK_CACHE, key); if (ptr == NULL) { DBG_DEBUG("failed to find entry for key %s\n", file_id_str_buf(id, &idbuf)); return NULL; } /* sequence number key is at start of blob. */ ndr_err = get_share_mode_blob_header( buf, buflen, &unique_content_epoch, &flags); if (ndr_err != NDR_ERR_SUCCESS) { /* Bad blob. Remove entry. */ DBG_DEBUG("bad blob %u key %s\n", (unsigned int)ndr_err, file_id_str_buf(id, &idbuf)); memcache_delete(NULL, SHARE_MODE_LOCK_CACHE, key); return NULL; } d = (struct share_mode_data *)ptr; if (d->unique_content_epoch != unique_content_epoch) { DBG_DEBUG("epoch changed (cached %"PRIx64") (new %"PRIx64") " "for key %s\n", d->unique_content_epoch, unique_content_epoch, file_id_str_buf(id, &idbuf)); /* Cache out of date. Remove entry. */ memcache_delete(NULL, SHARE_MODE_LOCK_CACHE, key); return NULL; } /* Move onto mem_ctx. */ d = talloc_move(mem_ctx, &ptr); /* * Now we own d, prevent the cache from freeing it * when we delete the entry. */ talloc_set_destructor(d, share_mode_data_nofree_destructor); /* Remove from the cache. We own it now. */ memcache_delete(NULL, SHARE_MODE_LOCK_CACHE, key); /* And reset the destructor to none. */ talloc_set_destructor(d, NULL); DBG_DEBUG("fetched entry for file %s epoch %"PRIx64" key %s\n", d->base_name, d->unique_content_epoch, file_id_str_buf(id, &idbuf)); return d; } /* * 132 is the sizeof an ndr-encoded struct share_mode_entry_buf. * Reading/writing entries will immediately error out if this * size differs (push/pull is done without allocs). */ struct share_mode_entry_buf { uint8_t buf[132]; }; #define SHARE_MODE_ENTRY_SIZE (sizeof(struct share_mode_entry_buf)) static bool share_mode_entry_put( const struct share_mode_entry *e, struct share_mode_entry_buf *dst) { DATA_BLOB blob = { .data = dst->buf, .length = sizeof(dst->buf) }; enum ndr_err_code ndr_err; if (DEBUGLEVEL>=10) { DBG_DEBUG("share_mode_entry:\n"); NDR_PRINT_DEBUG(share_mode_entry, discard_const_p(void, e)); } ndr_err = ndr_push_struct_into_fixed_blob( &blob, e, (ndr_push_flags_fn_t)ndr_push_share_mode_entry); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_WARNING("ndr_push_share_mode_entry failed: %s\n", ndr_errstr(ndr_err)); return false; } return true; } static bool share_mode_entry_get( const uint8_t ptr[SHARE_MODE_ENTRY_SIZE], struct share_mode_entry *e) { enum ndr_err_code ndr_err = NDR_ERR_SUCCESS; DATA_BLOB blob = { .data = discard_const_p(uint8_t, ptr), .length = SHARE_MODE_ENTRY_SIZE, }; ndr_err = ndr_pull_struct_blob_all_noalloc( &blob, e, (ndr_pull_flags_fn_t)ndr_pull_share_mode_entry); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_WARNING("ndr_pull_share_mode_entry failed\n"); return false; } return true; } /* * locking.tdb records consist of * * uint32_t share_mode_data_len * uint8_t [share_mode_data] This is struct share_mode_data in NDR * * 0 [SHARE_MODE_ENTRY_SIZE] Sorted array of share modes, * 1 [SHARE_MODE_ENTRY_SIZE] filling up the rest of the data in the * 2 [SHARE_MODE_ENTRY_SIZE] g_lock.c maintained record in locking.tdb */ struct locking_tdb_data { const uint8_t *share_mode_data_buf; size_t share_mode_data_len; const uint8_t *share_entries; size_t num_share_entries; }; static bool locking_tdb_data_get( struct locking_tdb_data *data, const uint8_t *buf, size_t buflen) { uint32_t share_mode_data_len, share_entries_len; if (buflen == 0) { *data = (struct locking_tdb_data) { 0 }; return true; } if (buflen < sizeof(uint32_t)) { return false; } share_mode_data_len = PULL_LE_U32(buf, 0); buf += sizeof(uint32_t); buflen -= sizeof(uint32_t); if (buflen < share_mode_data_len) { return false; } share_entries_len = buflen - share_mode_data_len; if ((share_entries_len % SHARE_MODE_ENTRY_SIZE) != 0) { return false; } *data = (struct locking_tdb_data) { .share_mode_data_buf = buf, .share_mode_data_len = share_mode_data_len, .share_entries = buf + share_mode_data_len, .num_share_entries = share_entries_len / SHARE_MODE_ENTRY_SIZE, }; return true; } struct locking_tdb_data_fetch_state { TALLOC_CTX *mem_ctx; uint8_t *data; size_t datalen; }; static void locking_tdb_data_fetch_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct locking_tdb_data_fetch_state *state = private_data; state->datalen = datalen; state->data = talloc_memdup(state->mem_ctx, data, datalen); } static NTSTATUS locking_tdb_data_fetch( TDB_DATA key, TALLOC_CTX *mem_ctx, struct locking_tdb_data **ltdb) { struct locking_tdb_data_fetch_state state = { 0 }; struct locking_tdb_data *result = NULL; NTSTATUS status; bool ok; result = talloc_zero(mem_ctx, struct locking_tdb_data); if (result == NULL) { return NT_STATUS_NO_MEMORY; } state.mem_ctx = result; status = share_mode_g_lock_dump(key, locking_tdb_data_fetch_fn, &state); if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { /* * Just return an empty record */ goto done; } if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_g_lock_dump failed: %s\n", nt_errstr(status)); return status; } if (state.datalen == 0) { goto done; } ok = locking_tdb_data_get(result, state.data, state.datalen); if (!ok) { DBG_ERR("locking_tdb_data_get failed for %zu bytes\n", state.datalen); TALLOC_FREE(result); return NT_STATUS_INTERNAL_DB_CORRUPTION; } done: *ltdb = result; return NT_STATUS_OK; } static NTSTATUS locking_tdb_data_store( TDB_DATA key, const struct locking_tdb_data *ltdb, const TDB_DATA *share_mode_dbufs, size_t num_share_mode_dbufs) { uint8_t share_mode_data_len_buf[4]; TDB_DATA dbufs[num_share_mode_dbufs+3]; NTSTATUS status; if ((ltdb->share_mode_data_len == 0) && (ltdb->num_share_entries == 0) && (num_share_mode_dbufs == 0)) { /* * Nothing to write */ status = share_mode_g_lock_writev(key, NULL, 0); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_g_lock_writev(NULL) failed: %s\n", nt_errstr(status)); } return status; } PUSH_LE_U32(share_mode_data_len_buf, 0, ltdb->share_mode_data_len); dbufs[0] = (TDB_DATA) { .dptr = share_mode_data_len_buf, .dsize = sizeof(share_mode_data_len_buf), }; dbufs[1] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_mode_data_buf), .dsize = ltdb->share_mode_data_len, }; if (ltdb->num_share_entries > SIZE_MAX/SHARE_MODE_ENTRY_SIZE) { /* overflow */ return NT_STATUS_BUFFER_OVERFLOW; } dbufs[2] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries), .dsize = ltdb->num_share_entries * SHARE_MODE_ENTRY_SIZE, }; if (num_share_mode_dbufs != 0) { memcpy(&dbufs[3], share_mode_dbufs, num_share_mode_dbufs * sizeof(TDB_DATA)); } status = share_mode_g_lock_writev(key, dbufs, ARRAY_SIZE(dbufs)); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_g_lock_writev() failed: %s\n", nt_errstr(status)); } return status; } /******************************************************************* Get all share mode entries for a dev/inode pair. ********************************************************************/ static struct share_mode_data *parse_share_modes( TALLOC_CTX *mem_ctx, struct file_id id, const uint8_t *buf, size_t buflen) { struct share_mode_data *d; enum ndr_err_code ndr_err; DATA_BLOB blob; /* See if we already have a cached copy of this key. */ d = share_mode_memcache_fetch(mem_ctx, id, buf, buflen); if (d != NULL) { return d; } d = talloc(mem_ctx, struct share_mode_data); if (d == NULL) { DEBUG(0, ("talloc failed\n")); goto fail; } blob = (DATA_BLOB) { .data = discard_const_p(uint8_t, buf), .length = buflen, }; ndr_err = ndr_pull_struct_blob_all( &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_WARNING("ndr_pull_share_mode_data failed: %s\n", ndr_errstr(ndr_err)); goto fail; } if (DEBUGLEVEL >= 10) { DEBUG(10, ("parse_share_modes:\n")); NDR_PRINT_DEBUG(share_mode_data, d); } return d; fail: TALLOC_FREE(d); return NULL; } static NTSTATUS share_mode_data_ltdb_store(struct share_mode_data *d, TDB_DATA key, struct locking_tdb_data *ltdb, const TDB_DATA *share_mode_dbufs, size_t num_share_mode_dbufs) { DATA_BLOB blob = { 0 }; NTSTATUS status; if (!d->modified) { DBG_DEBUG("share_mode_data not modified\n"); goto store; } d->unique_content_epoch = generate_unique_u64(d->unique_content_epoch); if (DEBUGLEVEL >= 10) { DBG_DEBUG("\n"); NDR_PRINT_DEBUG(share_mode_data, d); } if (ltdb->num_share_entries != 0 || num_share_mode_dbufs != 0) { enum ndr_err_code ndr_err; ndr_err = ndr_push_struct_blob( &blob, ltdb, d, (ndr_push_flags_fn_t)ndr_push_share_mode_data); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_ERR("ndr_push_share_mode_data failed: %s\n", ndr_errstr(ndr_err)); return ndr_map_error2ntstatus(ndr_err); } } ltdb->share_mode_data_buf = blob.data; ltdb->share_mode_data_len = blob.length; store: status = locking_tdb_data_store(key, ltdb, share_mode_dbufs, num_share_mode_dbufs); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_store failed: %s\n", nt_errstr(status)); return status; } d->modified = false; d->not_stored = (ltdb->share_mode_data_len == 0); return NT_STATUS_OK; } /******************************************************************* If modified, store the share_mode_data back into the database. ********************************************************************/ static NTSTATUS share_mode_data_store(struct share_mode_data *d) { TDB_DATA key = locking_key(&d->id); struct locking_tdb_data *ltdb = NULL; NTSTATUS status; if (!d->modified) { DBG_DEBUG("not modified\n"); return NT_STATUS_OK; } if (DEBUGLEVEL >= 10) { DBG_DEBUG("\n"); NDR_PRINT_DEBUG(share_mode_data, d); } status = locking_tdb_data_fetch(key, d, <db); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_fetch failed: %s\n", nt_errstr(status)); return status; } status = share_mode_data_ltdb_store(d, key, ltdb, NULL, 0); TALLOC_FREE(ltdb); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_ltdb_store failed: %s\n", nt_errstr(status)); return status; } return NT_STATUS_OK; } /******************************************************************* Allocate a new share_mode_data struct, mark it unmodified. fresh is set to note that currently there is no database entry. ********************************************************************/ static struct share_mode_data *fresh_share_mode_lock( TALLOC_CTX *mem_ctx, const char *servicepath, const struct smb_filename *smb_fname, const struct timespec *old_write_time) { struct share_mode_data *d; if ((servicepath == NULL) || (smb_fname == NULL) || (old_write_time == NULL)) { return NULL; } d = talloc_zero(mem_ctx, struct share_mode_data); if (d == NULL) { goto fail; } d->unique_content_epoch = generate_unique_u64(0); d->base_name = talloc_strdup(d, smb_fname->base_name); if (d->base_name == NULL) { goto fail; } if (smb_fname->stream_name != NULL) { d->stream_name = talloc_strdup(d, smb_fname->stream_name); if (d->stream_name == NULL) { goto fail; } } d->servicepath = talloc_strdup(d, servicepath); if (d->servicepath == NULL) { goto fail; } d->old_write_time = full_timespec_to_nt_time(old_write_time); d->flags = SHARE_MODE_SHARE_DELETE | SHARE_MODE_SHARE_WRITE | SHARE_MODE_SHARE_READ; d->modified = false; d->not_stored = true; return d; fail: DEBUG(0, ("talloc failed\n")); TALLOC_FREE(d); return NULL; } /* * Key that's locked with g_lock */ static struct file_id share_mode_lock_key_id = {}; static TDB_DATA share_mode_lock_key = { .dptr = (uint8_t *)&share_mode_lock_key_id, .dsize = sizeof(share_mode_lock_key_id), }; static size_t share_mode_lock_key_refcount = 0; static bool share_mode_g_lock_within_cb(TDB_DATA key) { int cmp; if (current_share_mode_glck == NULL) { return false; } cmp = tdb_data_cmp(share_mode_lock_key, key); if (cmp != 0) { struct file_id_buf existing; DBG_ERR("Can not lock two share modes " "simultaneously: existing %s requested %s\n", file_id_str_buf(share_mode_lock_key_id, &existing), tdb_data_dbg(key)); smb_panic(__location__); return false; } return true; } /* * We can only ever have one share mode locked. Use a static * share_mode_data pointer that is shared by multiple nested * share_mode_lock structures, explicitly refcounted. */ static struct share_mode_data *static_share_mode_data = NULL; /******************************************************************* Either fetch a share mode from the database, or allocate a fresh one if the record doesn't exist. ********************************************************************/ struct get_static_share_mode_data_state { TALLOC_CTX *mem_ctx; struct file_id id; const char *servicepath; const struct smb_filename *smb_fname; const struct timespec *old_write_time; NTSTATUS status; }; static void get_static_share_mode_data_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct get_static_share_mode_data_state *state = private_data; struct share_mode_data *d = NULL; struct locking_tdb_data ltdb = { 0 }; if (datalen != 0) { bool ok; ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_ERR("locking_tdb_data_get failed\n"); state->status = NT_STATUS_INTERNAL_DB_CORRUPTION; return; } } if (ltdb.share_mode_data_len == 0) { if (state->smb_fname == NULL) { state->status = NT_STATUS_NOT_FOUND; return; } d = fresh_share_mode_lock( state->mem_ctx, state->servicepath, state->smb_fname, state->old_write_time); if (d == NULL) { state->status = NT_STATUS_NO_MEMORY; return; } } else { d = parse_share_modes( lock_ctx, state->id, ltdb.share_mode_data_buf, ltdb.share_mode_data_len); if (d == NULL) { state->status = NT_STATUS_INTERNAL_DB_CORRUPTION; return; } } d->id = state->id; static_share_mode_data = d; } static NTSTATUS get_static_share_mode_data( struct file_id id, const char *servicepath, const struct smb_filename *smb_fname, const struct timespec *old_write_time) { struct get_static_share_mode_data_state state = { .mem_ctx = lock_ctx, .id = id, .servicepath = servicepath, .smb_fname = smb_fname, .old_write_time = old_write_time, }; NTSTATUS status; SMB_ASSERT(static_share_mode_data == NULL); status = share_mode_g_lock_dump( share_mode_lock_key, get_static_share_mode_data_fn, &state); if (!NT_STATUS_IS_OK(status)) { DBG_GET_SHARE_MODE_LOCK(status, "share_mode_g_lock_dump failed: %s\n", nt_errstr(status)); return status; } if (!NT_STATUS_IS_OK(state.status)) { DBG_GET_SHARE_MODE_LOCK(state.status, "get_static_share_mode_data_fn failed: %s\n", nt_errstr(state.status)); return state.status; } return NT_STATUS_OK; } struct file_id share_mode_lock_file_id(const struct share_mode_lock *lck) { return lck->id; } NTSTATUS share_mode_lock_access_private_data(struct share_mode_lock *lck, struct share_mode_data **data) { /* * For now we always have lck->cached_data, * but we may change that in future. */ SMB_ASSERT(lck->cached_data != NULL); *data = lck->cached_data; return NT_STATUS_OK; } /******************************************************************* Get a share_mode_lock, Reference counted to allow nested calls. ********************************************************************/ static int share_mode_lock_destructor(struct share_mode_lock *lck); static bool share_mode_lock_skip_g_lock; static NTSTATUS get_share_mode_lock_internal( struct file_id id, const char *servicepath, const struct smb_filename *smb_fname, const struct timespec *old_write_time, struct share_mode_lock *lck) { NTSTATUS status; *lck = (struct share_mode_lock) { .id = id, }; if (share_mode_lock_key_refcount == 0) { if (!share_mode_lock_skip_g_lock) { TDB_DATA key = locking_key(&id); status = g_lock_lock( lock_ctx, key, G_LOCK_WRITE, (struct timeval) { .tv_sec = 3600 }, NULL, NULL); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("g_lock_lock failed: %s\n", nt_errstr(status)); return status; } } share_mode_lock_key_id = id; } if (!file_id_equal(&share_mode_lock_key_id, &id)) { struct file_id_buf existing; struct file_id_buf requested; DBG_ERR("Can not lock two share modes " "simultaneously: existing %s requested %s\n", file_id_str_buf(share_mode_lock_key_id, &existing), file_id_str_buf(id, &requested)); smb_panic(__location__); goto fail; } SMB_ASSERT(share_mode_lock_key_refcount < SIZE_MAX); share_mode_lock_key_refcount += 1; if (static_share_mode_data != NULL) { goto done; } status = get_static_share_mode_data( id, servicepath, smb_fname, old_write_time); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("get_static_share_mode_data failed: %s\n", nt_errstr(status)); share_mode_lock_key_refcount -= 1; goto fail; } done: lck->cached_data = static_share_mode_data; if (CHECK_DEBUGLVL(DBGLVL_DEBUG)) { struct file_id_buf returned; DBG_DEBUG("Returning %s (data_cached=%u key_refcount=%zu)\n", file_id_str_buf(id, &returned), static_share_mode_data != NULL, share_mode_lock_key_refcount); } return NT_STATUS_OK; fail: if (share_mode_lock_key_refcount == 0) { if (!share_mode_lock_skip_g_lock) { NTSTATUS ulstatus = g_lock_unlock(lock_ctx, share_mode_lock_key); if (!NT_STATUS_IS_OK(ulstatus)) { DBG_ERR("g_lock_unlock failed: %s\n", nt_errstr(ulstatus)); } } } return status; } static NTSTATUS put_share_mode_lock_internal(struct share_mode_lock *lck) { NTSTATUS status; SMB_ASSERT(share_mode_lock_key_refcount > 0); share_mode_lock_key_refcount -= 1; if (share_mode_lock_key_refcount > 0) { return NT_STATUS_OK; } status = share_mode_data_store(static_share_mode_data); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_store failed: %s\n", nt_errstr(status)); return status; } if (!share_mode_lock_skip_g_lock) { status = g_lock_unlock(lock_ctx, share_mode_lock_key); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("g_lock_unlock failed: %s\n", nt_errstr(status)); return status; } } if (!static_share_mode_data->not_stored) { /* * This is worth keeping. Without share modes, * share_mode_data_store above has left nothing in the * database. */ share_mode_memcache_store(static_share_mode_data); static_share_mode_data = NULL; } TALLOC_FREE(static_share_mode_data); return NT_STATUS_OK; } static int share_mode_lock_destructor(struct share_mode_lock *lck) { NTSTATUS status; status = put_share_mode_lock_internal(lck); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(status)); smb_panic("put_share_mode_lock_internal failed\n"); } return 0; } /******************************************************************* Fetch a share mode where we know one MUST exist. This call reference counts it internally to allow for nested lock fetches. ********************************************************************/ struct share_mode_lock *get_existing_share_mode_lock(TALLOC_CTX *mem_ctx, const struct file_id id) { struct share_mode_lock *lck = NULL; NTSTATUS status; lck = talloc(mem_ctx, struct share_mode_lock); if (lck == NULL) { return NULL; } status = get_share_mode_lock_internal(id, NULL, /* servicepath */ NULL, /* smb_fname */ NULL, /* old_write_time */ lck); if (!NT_STATUS_IS_OK(status)) { DBG_GET_SHARE_MODE_LOCK(status, "get_share_mode_lock_internal() failed - %s\n", nt_errstr(status)); TALLOC_FREE(lck); return NULL; } talloc_set_destructor(lck, share_mode_lock_destructor); return lck; } static void share_mode_wakeup_waiters_fn( struct share_mode_lock *lck, void *private_data) { if (share_mode_g_lock_within_cb(share_mode_lock_key)) { g_lock_lock_cb_wake_watchers(current_share_mode_glck); return; } g_lock_wake_watchers(lock_ctx, share_mode_lock_key); } NTSTATUS share_mode_wakeup_waiters(struct file_id id) { return share_mode_do_locked_vfs_denied(id, share_mode_wakeup_waiters_fn, NULL); } struct fsp_update_share_mode_flags_state { struct files_struct *fsp; enum ndr_err_code ndr_err; uint64_t share_mode_epoch; uint16_t share_mode_flags; }; static void fsp_update_share_mode_flags_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct fsp_update_share_mode_flags_state *state = private_data; struct locking_tdb_data ltdb = { 0 }; if (datalen != 0) { bool ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_DEBUG("locking_tdb_data_get failed\n"); return; } } if (ltdb.share_mode_data_len == 0) { /* Likely a ctdb tombstone record, ignore it */ return; } if (exclusive.pid != 0) { struct server_id self = messaging_server_id(state->fsp->conn->sconn->msg_ctx); bool is_self = server_id_equal(&self, &exclusive); if (!is_self) { /* * If someone else is holding an exclusive * lock, pretend there's a read lease */ state->share_mode_flags = SHARE_MODE_LEASE_READ; return; } } state->ndr_err = get_share_mode_blob_header(ltdb.share_mode_data_buf, ltdb.share_mode_data_len, &state->share_mode_epoch, &state->share_mode_flags); } static NTSTATUS fsp_update_share_mode_flags(struct files_struct *fsp) { struct fsp_update_share_mode_flags_state state = { .fsp = fsp, }; int seqnum = g_lock_seqnum(lock_ctx); TDB_DATA key = {0}; NTSTATUS status; if (seqnum == fsp->share_mode_flags_seqnum) { return NT_STATUS_OK; } key = locking_key(&fsp->file_id); status = share_mode_g_lock_dump(key, fsp_update_share_mode_flags_fn, &state); if (!NT_STATUS_IS_OK(status)) { /* no DBG_GET_SHARE_MODE_LOCK here! */ DBG_ERR("share_mode_g_lock_dump returned %s\n", nt_errstr(status)); return status; } if (!NDR_ERR_CODE_IS_SUCCESS(state.ndr_err)) { DBG_ERR("get_share_mode_blob_header returned %s\n", ndr_errstr(state.ndr_err)); return ndr_map_error2ntstatus(state.ndr_err); } fsp->share_mode_flags_seqnum = seqnum; fsp->share_mode_flags = state.share_mode_flags; return NT_STATUS_OK; } bool file_has_read_lease(struct files_struct *fsp) { NTSTATUS status; status = fsp_update_share_mode_flags(fsp); if (!NT_STATUS_IS_OK(status)) { /* Safe default for leases */ return true; } return (fsp->share_mode_flags & SHARE_MODE_LEASE_READ) != 0; } #define share_mode_lock_assert_private_data(__lck) \ _share_mode_lock_assert_private_data(__lck, __func__, __location__) static struct share_mode_data *_share_mode_lock_assert_private_data( struct share_mode_lock *lck, const char *caller_function, const char *caller_location) { struct share_mode_data *d = NULL; NTSTATUS status; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { struct file_id id = share_mode_lock_file_id(lck); struct file_id_buf id_buf; /* Any error recovery possible here ? */ D_ERR("%s:%s(): share_mode_lock_access_private_data() " "failed for id=%s - %s\n", caller_location, caller_function, file_id_str_buf(id, &id_buf), nt_errstr(status)); smb_panic(caller_location); return NULL; } return d; } NTTIME share_mode_changed_write_time(struct share_mode_lock *lck) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); return d->changed_write_time; } void share_mode_set_changed_write_time(struct share_mode_lock *lck, struct timespec write_time) { struct file_id fileid = share_mode_lock_file_id(lck); struct share_mode_data *d = share_mode_lock_assert_private_data(lck); struct file_id_buf ftmp; struct timeval_buf tbuf; NTTIME nt = full_timespec_to_nt_time(&write_time); DBG_INFO("%s id=%s\n", timespec_string_buf(&write_time, true, &tbuf), file_id_str_buf(fileid, &ftmp)); if (d->changed_write_time != nt) { d->modified = true; d->changed_write_time = nt; } } void share_mode_set_old_write_time(struct share_mode_lock *lck, struct timespec write_time) { struct file_id fileid = share_mode_lock_file_id(lck); struct share_mode_data *d = share_mode_lock_assert_private_data(lck); struct file_id_buf ftmp; struct timeval_buf tbuf; NTTIME nt = full_timespec_to_nt_time(&write_time); DBG_INFO("%s id=%s\n", timespec_string_buf(&write_time, true, &tbuf), file_id_str_buf(fileid, &ftmp)); if (d->changed_write_time != nt) { d->modified = true; d->old_write_time = nt; } } const char *share_mode_servicepath(struct share_mode_lock *lck) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); return d->servicepath; } char *share_mode_filename(TALLOC_CTX *mem_ctx, struct share_mode_lock *lck) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); bool has_stream = (d->stream_name != NULL); char *fname = NULL; fname = talloc_asprintf( mem_ctx, "%s%s%s", d->base_name, has_stream ? ":" : "", has_stream ? d->stream_name : ""); return fname; } char *share_mode_data_dump( TALLOC_CTX *mem_ctx, struct share_mode_lock *lck) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); struct ndr_print *p = talloc(mem_ctx, struct ndr_print); char *ret = NULL; if (p == NULL) { return NULL; } *p = (struct ndr_print) { .print = ndr_print_string_helper, .depth = 1, .private_data = talloc_strdup(mem_ctx, ""), }; if (p->private_data == NULL) { TALLOC_FREE(p); return NULL; } ndr_print_share_mode_data(p, "SHARE_MODE_DATA", d); ret = p->private_data; TALLOC_FREE(p); return ret; } void share_mode_flags_get( struct share_mode_lock *lck, uint32_t *access_mask, uint32_t *share_mode, uint32_t *lease_type) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); uint16_t flags = d->flags; if (access_mask != NULL) { *access_mask = ((flags & SHARE_MODE_ACCESS_READ) ? FILE_READ_DATA : 0) | ((flags & SHARE_MODE_ACCESS_WRITE) ? FILE_WRITE_DATA : 0) | ((flags & SHARE_MODE_ACCESS_DELETE) ? DELETE_ACCESS : 0); } if (share_mode != NULL) { *share_mode = ((flags & SHARE_MODE_SHARE_READ) ? FILE_SHARE_READ : 0) | ((flags & SHARE_MODE_SHARE_WRITE) ? FILE_SHARE_WRITE : 0) | ((flags & SHARE_MODE_SHARE_DELETE) ? FILE_SHARE_DELETE : 0); } if (lease_type != NULL) { *lease_type = ((flags & SHARE_MODE_LEASE_READ) ? SMB2_LEASE_READ : 0) | ((flags & SHARE_MODE_LEASE_WRITE) ? SMB2_LEASE_WRITE : 0) | ((flags & SHARE_MODE_LEASE_HANDLE) ? SMB2_LEASE_HANDLE : 0); } } void share_mode_flags_set( struct share_mode_lock *lck, uint32_t access_mask, uint32_t share_mode, uint32_t lease_type, bool *modified) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); uint16_t flags = 0; flags |= (access_mask & (FILE_READ_DATA | FILE_EXECUTE)) ? SHARE_MODE_ACCESS_READ : 0; flags |= (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? SHARE_MODE_ACCESS_WRITE : 0; flags |= (access_mask & (DELETE_ACCESS)) ? SHARE_MODE_ACCESS_DELETE : 0; flags |= (share_mode & FILE_SHARE_READ) ? SHARE_MODE_SHARE_READ : 0; flags |= (share_mode & FILE_SHARE_WRITE) ? SHARE_MODE_SHARE_WRITE : 0; flags |= (share_mode & FILE_SHARE_DELETE) ? SHARE_MODE_SHARE_DELETE : 0; flags |= (lease_type & SMB2_LEASE_READ) ? SHARE_MODE_LEASE_READ : 0; flags |= (lease_type & SMB2_LEASE_WRITE) ? SHARE_MODE_LEASE_WRITE : 0; flags |= (lease_type & SMB2_LEASE_HANDLE) ? SHARE_MODE_LEASE_HANDLE : 0; if (d->flags == flags) { return; } if (modified != NULL) { *modified = true; } d->flags = flags; d->modified = true; } struct share_mode_watch_state { bool blockerdead; struct server_id blocker; bool within_cb; }; static void share_mode_watch_done(struct tevent_req *subreq); struct tevent_req *share_mode_watch_send( TALLOC_CTX *mem_ctx, struct tevent_context *ev, struct share_mode_lock *lck, struct server_id blocker) { struct file_id id = share_mode_lock_file_id(lck); TDB_DATA key = locking_key(&id); struct tevent_req *req = NULL, *subreq = NULL; struct share_mode_watch_state *state = NULL; req = tevent_req_create( mem_ctx, &state, struct share_mode_watch_state); if (req == NULL) { return NULL; } if (share_mode_g_lock_within_cb(key)) { state->within_cb = true; subreq = g_lock_lock_cb_watch_data_send(state, ev, current_share_mode_glck, blocker); if (tevent_req_nomem(subreq, req)) { return tevent_req_post(req, ev); } } else { subreq = g_lock_watch_data_send(state, ev, lock_ctx, key, blocker); if (tevent_req_nomem(subreq, req)) { return tevent_req_post(req, ev); } } tevent_req_set_callback(subreq, share_mode_watch_done, req); return req; } static void share_mode_watch_done(struct tevent_req *subreq) { struct tevent_req *req = tevent_req_callback_data( subreq, struct tevent_req); struct share_mode_watch_state *state = tevent_req_data( req, struct share_mode_watch_state); NTSTATUS status; if (state->within_cb) { status = g_lock_lock_cb_watch_data_recv( subreq, &state->blockerdead, &state->blocker); if (tevent_req_nterror(req, status)) { return; } } else { status = g_lock_watch_data_recv( subreq, &state->blockerdead, &state->blocker); if (tevent_req_nterror(req, status)) { return; } } tevent_req_done(req); } NTSTATUS share_mode_watch_recv( struct tevent_req *req, bool *blockerdead, struct server_id *blocker) { struct share_mode_watch_state *state = tevent_req_data( req, struct share_mode_watch_state); NTSTATUS status; if (tevent_req_is_nterror(req, &status)) { return status; } if (blockerdead != NULL) { *blockerdead = state->blockerdead; } if (blocker != NULL) { *blocker = state->blocker; } return NT_STATUS_OK; } struct fetch_share_mode_unlocked_state { TALLOC_CTX *mem_ctx; struct file_id id; struct share_mode_lock *lck; }; static void fetch_share_mode_unlocked_parser( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct fetch_share_mode_unlocked_state *state = private_data; struct locking_tdb_data ltdb = { 0 }; if (datalen != 0) { bool ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_DEBUG("locking_tdb_data_get failed\n"); return; } } if (ltdb.share_mode_data_len == 0) { /* Likely a ctdb tombstone record, ignore it */ return; } state->lck = talloc(state->mem_ctx, struct share_mode_lock); if (state->lck == NULL) { DEBUG(0, ("talloc failed\n")); return; } state->lck->id = state->id; state->lck->cached_data = parse_share_modes( state->lck, state->id, ltdb.share_mode_data_buf, ltdb.share_mode_data_len); if (state->lck->cached_data == NULL) { DBG_DEBUG("parse_share_modes failed\n"); TALLOC_FREE(state->lck); } } /******************************************************************* Get a share_mode_lock without locking the database or reference counting. Used by smbstatus to display existing share modes. ********************************************************************/ struct share_mode_lock *fetch_share_mode_unlocked(TALLOC_CTX *mem_ctx, struct file_id id) { struct fetch_share_mode_unlocked_state state = { .mem_ctx = mem_ctx, .id = id, }; TDB_DATA key = locking_key(&id); NTSTATUS status; status = g_lock_dump( lock_ctx, key, fetch_share_mode_unlocked_parser, &state); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("g_lock_dump failed: %s\n", nt_errstr(status)); return NULL; } return state.lck; } struct fetch_share_mode_state { struct file_id id; struct share_mode_lock *lck; NTSTATUS status; }; static void fetch_share_mode_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data); static void fetch_share_mode_done(struct tevent_req *subreq); /** * @brief Get a share_mode_lock without locking or refcounting * * This can be used in a clustered Samba environment where the async dbwrap * request is sent over a socket to the local ctdbd. If the send queue is full * and the caller was issuing multiple async dbwrap requests in a loop, the * caller knows it's probably time to stop sending requests for now and try * again later. * * @param[in] mem_ctx The talloc memory context to use. * * @param[in] ev The event context to work on. * * @param[in] id The file id for the locking.tdb key * * @param[out] queued This boolean out parameter tells the caller whether the * async request is blocked in a full send queue: * * false := request is dispatched * * true := send queue is full, request waiting to be * dispatched * * @return The new async request, NULL on error. **/ struct tevent_req *fetch_share_mode_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev, struct file_id id, bool *queued) { struct tevent_req *req = NULL, *subreq = NULL; struct fetch_share_mode_state *state = NULL; *queued = false; req = tevent_req_create(mem_ctx, &state, struct fetch_share_mode_state); if (req == NULL) { return NULL; } state->id = id; subreq = g_lock_dump_send( state, ev, lock_ctx, locking_key(&id), fetch_share_mode_fn, state); if (tevent_req_nomem(subreq, req)) { return tevent_req_post(req, ev); } tevent_req_set_callback(subreq, fetch_share_mode_done, req); return req; } static void fetch_share_mode_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct fetch_share_mode_state *state = talloc_get_type_abort( private_data, struct fetch_share_mode_state); struct locking_tdb_data ltdb = { 0 }; if (datalen != 0) { bool ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_DEBUG("locking_tdb_data_get failed\n"); return; } } if (ltdb.share_mode_data_len == 0) { /* Likely a ctdb tombstone record, ignore it */ return; } state->lck = talloc(state, struct share_mode_lock); if (state->lck == NULL) { DBG_WARNING("talloc failed\n"); state->status = NT_STATUS_NO_MEMORY; return; } state->lck->id = state->id, state->lck->cached_data = parse_share_modes( state->lck, state->id, ltdb.share_mode_data_buf, ltdb.share_mode_data_len); if (state->lck->cached_data == NULL) { DBG_DEBUG("parse_share_modes failed\n"); state->status = NT_STATUS_INTERNAL_DB_CORRUPTION; TALLOC_FREE(state->lck); return; } } static void fetch_share_mode_done(struct tevent_req *subreq) { struct tevent_req *req = tevent_req_callback_data( subreq, struct tevent_req); struct fetch_share_mode_state *state = tevent_req_data( req, struct fetch_share_mode_state); NTSTATUS status; status = g_lock_dump_recv(subreq); TALLOC_FREE(subreq); if (tevent_req_nterror(req, status)) { return; } if (tevent_req_nterror(req, state->status)) { return; } tevent_req_done(req); } NTSTATUS fetch_share_mode_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct share_mode_lock **_lck) { struct fetch_share_mode_state *state = tevent_req_data( req, struct fetch_share_mode_state); struct share_mode_lock *lck = NULL; NTSTATUS status; if (tevent_req_is_nterror(req, &status)) { tevent_req_received(req); return status; } if (state->lck == NULL) { tevent_req_received(req); return NT_STATUS_NOT_FOUND; } lck = talloc_move(mem_ctx, &state->lck); if (DEBUGLEVEL >= 10) { DBG_DEBUG("share_mode_data:\n"); NDR_PRINT_DEBUG(share_mode_data, lck->cached_data); } *_lck = lck; tevent_req_received(req); return NT_STATUS_OK; } struct share_mode_forall_state { TDB_DATA key; int (*fn)(struct file_id fid, const struct share_mode_data *data, void *private_data); void *private_data; }; static void share_mode_forall_dump_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct share_mode_forall_state *state = private_data; struct file_id fid; struct locking_tdb_data ltdb = { 0 }; bool ok; struct share_mode_data *d; if (state->key.dsize != sizeof(fid)) { DBG_DEBUG("Got invalid key length %zu\n", state->key.dsize); return; } memcpy(&fid, state->key.dptr, sizeof(fid)); ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_DEBUG("locking_tdb_data_get() failed\n"); return; } d = parse_share_modes( talloc_tos(), fid, ltdb.share_mode_data_buf, ltdb.share_mode_data_len); if (d == NULL) { DBG_DEBUG("parse_share_modes() failed\n"); return; } state->fn(fid, d, state->private_data); TALLOC_FREE(d); } static int share_mode_forall_fn(TDB_DATA key, void *private_data) { struct share_mode_forall_state *state = private_data; NTSTATUS status; state->key = key; status = share_mode_g_lock_dump( key, share_mode_forall_dump_fn, private_data); if (!NT_STATUS_IS_OK(status)) { DBG_GET_SHARE_MODE_LOCK(status, "g_lock_dump failed: %s\n", nt_errstr(status)); } return 0; } int share_mode_forall(int (*fn)(struct file_id fid, const struct share_mode_data *data, void *private_data), void *private_data) { struct share_mode_forall_state state = { .fn = fn, .private_data = private_data }; int ret; if (lock_ctx == NULL) { return 0; } ret = g_lock_locks( lock_ctx, share_mode_forall_fn, &state); if (ret < 0) { DBG_ERR("g_lock_locks failed\n"); } return ret; } struct share_entry_forall_state { struct file_id fid; const struct share_mode_data *data; int (*fn)(struct file_id fid, const struct share_mode_data *data, const struct share_mode_entry *entry, void *private_data); void *private_data; int ret; }; static bool share_entry_traverse_walker( struct share_mode_entry *e, bool *modified, void *private_data) { struct share_entry_forall_state *state = private_data; state->ret = state->fn( state->fid, state->data, e, state->private_data); return (state->ret != 0); } static int share_entry_traverse_fn(struct file_id fid, const struct share_mode_data *data, void *private_data) { struct share_entry_forall_state *state = private_data; struct share_mode_lock lck = { .id = fid, .cached_data = discard_const_p(struct share_mode_data, data) }; bool ok; state->fid = fid; state->data = data; ok = share_mode_forall_entries( &lck, share_entry_traverse_walker, state); if (!ok) { DBG_ERR("share_mode_forall_entries failed\n"); return false; } return state->ret; } /******************************************************************* Call the specified function on each entry under management by the share mode system. ********************************************************************/ int share_entry_forall(int (*fn)(struct file_id fid, const struct share_mode_data *data, const struct share_mode_entry *entry, void *private_data), void *private_data) { struct share_entry_forall_state state = { .fn = fn, .private_data = private_data }; return share_mode_forall(share_entry_traverse_fn, &state); } static int share_mode_entry_cmp( struct server_id pid1, uint64_t share_file_id1, struct server_id pid2, uint64_t share_file_id2) { int cmp; cmp = server_id_cmp(&pid1, &pid2); if (cmp != 0) { return cmp; } if (share_file_id1 != share_file_id2) { return (share_file_id1 < share_file_id2) ? -1 : 1; } return 0; } static size_t share_mode_entry_find( const uint8_t *data, size_t num_share_modes, struct server_id pid, uint64_t share_file_id, struct share_mode_entry *e, bool *match) { ssize_t left, right, middle; *match = false; if (num_share_modes == 0) { return 0; } left = 0; right = (num_share_modes-1); while (left <= right) { const uint8_t *middle_ptr = NULL; int cmp; bool ok; middle = left + ((right - left) / 2); middle_ptr = data + middle * SHARE_MODE_ENTRY_SIZE; DBG_DEBUG("left=%zu, right=%zu, middle=%zu, middle_ptr=%p\n", left, right, middle, middle_ptr); ok = share_mode_entry_get(middle_ptr, e); if (!ok) { DBG_DEBUG("share_mode_entry_get failed\n"); return 0; } cmp = share_mode_entry_cmp( e->pid, e->share_file_id, pid, share_file_id); if (cmp == 0) { *match = true; return middle; } if (cmp < 0) { right = middle-1; } else { left = middle+1; } } return left; } bool set_share_mode(struct share_mode_lock *lck, struct files_struct *fsp, uid_t uid, uint64_t mid, uint16_t op_type, const struct smb2_lease_key *lease_key, uint32_t share_access, uint32_t access_mask) { struct share_mode_data *d = share_mode_lock_assert_private_data(lck); TDB_DATA key = locking_key(&d->id); struct server_id my_pid = messaging_server_id( fsp->conn->sconn->msg_ctx); struct locking_tdb_data *ltdb = NULL; size_t idx; struct share_mode_entry e = { .pid.pid = 0 }; struct share_mode_entry_buf e_buf; NTSTATUS status; bool ok, found; TDB_DATA dbufs[3]; size_t num_dbufs = 0; status = locking_tdb_data_fetch(key, talloc_tos(), <db); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_fetch failed: %s\n", nt_errstr(status)); return false; } DBG_DEBUG("num_share_modes=%zu\n", ltdb->num_share_entries); idx = share_mode_entry_find( ltdb->share_entries, ltdb->num_share_entries, my_pid, fh_get_gen_id(fsp->fh), &e, &found); if (found) { DBG_WARNING("Found duplicate share mode\n"); status = NT_STATUS_INTERNAL_DB_CORRUPTION; goto done; } e = (struct share_mode_entry) { .pid = my_pid, .share_access = share_access, .private_options = fh_get_private_options(fsp->fh), .access_mask = access_mask, .op_mid = mid, .op_type = op_type, .time.tv_sec = fsp->open_time.tv_sec, .time.tv_usec = fsp->open_time.tv_usec, .share_file_id = fh_get_gen_id(fsp->fh), .uid = (uint32_t)uid, .flags = (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) ? SHARE_MODE_FLAG_POSIX_OPEN : 0, .name_hash = fsp->name_hash, }; if (op_type == LEASE_OPLOCK) { const struct GUID *client_guid = fsp_client_guid(fsp); e.client_guid = *client_guid; e.lease_key = *lease_key; } ok = share_mode_entry_put(&e, &e_buf); if (!ok) { DBG_DEBUG("share_mode_entry_put failed\n"); status = NT_STATUS_INTERNAL_ERROR; goto done; } DBG_DEBUG("idx=%zu, found=%d\n", idx, (int)found); if (idx > 0) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries), .dsize = idx * SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } dbufs[num_dbufs] = (TDB_DATA) { .dptr = e_buf.buf, .dsize = SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; if (idx < ltdb->num_share_entries) { size_t num_after_idx = (ltdb->num_share_entries-idx); dbufs[num_dbufs] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries) + idx * SHARE_MODE_ENTRY_SIZE, .dsize = num_after_idx * SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } { size_t i; for (i=0; imodified = true; } /* * If there was any existing data in * ltdb->share_entries, it's now been * moved and we've split it into: * * num_dbufs = 3 * dbufs[0] -> old sorted data less than new_entry * dbufs[1] -> new_share_mode_entry * dbufs[2] -> old sorted_data greater than new entry. * * So the old data inside ltdb->share_entries is * no longer valid. * * If we're storing a brand new entry the * dbufs look like: * * num_dbufs = 1 * dbufs[0] -> new_share_mode_entry * * Either way we must set ltdb->share_entries = NULL * and ltdb->num_share_entries = 0 so that * locking_tdb_data_store() doesn't use it to * store any data. It's no longer there. */ ltdb->share_entries = NULL; ltdb->num_share_entries = 0; status = share_mode_data_ltdb_store(d, key, ltdb, dbufs, num_dbufs); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_ltdb_store failed: %s\n", nt_errstr(status)); } done: TALLOC_FREE(ltdb); return NT_STATUS_IS_OK(status); } static bool share_mode_for_one_entry( bool (*fn)(struct share_mode_entry *e, bool *modified, void *private_data), void *private_data, size_t *i, uint8_t *data, size_t *num_share_modes, bool *writeback) { DATA_BLOB blob = { .data = data + (*i) * SHARE_MODE_ENTRY_SIZE, .length = SHARE_MODE_ENTRY_SIZE, }; struct share_mode_entry e = {.pid.pid=0}; enum ndr_err_code ndr_err = NDR_ERR_SUCCESS; bool modified = false; bool stop = false; struct server_id e_pid; uint64_t e_share_file_id; ndr_err = ndr_pull_struct_blob_all_noalloc( &blob, &e, (ndr_pull_flags_fn_t)ndr_pull_share_mode_entry); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_WARNING("ndr_pull_share_mode_entry failed\n"); *i += 1; return false; } if (DEBUGLEVEL >= 10) { DBG_DEBUG("entry[%zu]:\n", *i); NDR_PRINT_DEBUG(share_mode_entry, &e); } e_pid = e.pid; e_share_file_id = e.share_file_id; stop = fn(&e, &modified, private_data); DBG_DEBUG("entry[%zu]: modified=%d, e.stale=%d\n", *i, (int)modified, (int)e.stale); if (e.stale) { if (DEBUGLEVEL>=10) { DBG_DEBUG("share_mode_entry:\n"); NDR_PRINT_DEBUG(share_mode_entry, &e); } if (*i < *num_share_modes) { memmove(blob.data, blob.data + SHARE_MODE_ENTRY_SIZE, (*num_share_modes - *i - 1) * SHARE_MODE_ENTRY_SIZE); } *num_share_modes -= 1; *writeback = true; return stop; } if (modified) { if (DEBUGLEVEL>=10) { DBG_DEBUG("share_mode_entry:\n"); NDR_PRINT_DEBUG(share_mode_entry, &e); } /* * Make sure sorting order is kept intact */ SMB_ASSERT(server_id_equal(&e_pid, &e.pid)); SMB_ASSERT(e_share_file_id == e.share_file_id); ndr_err = ndr_push_struct_into_fixed_blob( &blob, &e, (ndr_push_flags_fn_t) ndr_push_share_mode_entry); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_WARNING("ndr_push_share_mode_entry " "failed: %s\n", ndr_errstr(ndr_err)); /* * Not much we can do, just ignore it */ } *i += 1; *writeback = true; return stop; } if (stop) { return true; } *i += 1; return false; } bool share_mode_forall_entries( struct share_mode_lock *lck, bool (*fn)(struct share_mode_entry *e, bool *modified, void *private_data), void *private_data) { struct file_id id = share_mode_lock_file_id(lck); struct share_mode_data *d = NULL; TDB_DATA key = locking_key(&id); struct locking_tdb_data *ltdb = NULL; uint8_t *share_entries = NULL; size_t num_share_entries; bool writeback = false; NTSTATUS status; bool stop = false; size_t i; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { struct file_id_buf id_buf; /* Any error recovery possible here ? */ DBG_ERR("share_mode_lock_access_private_data() failed for " "%s - %s\n", file_id_str_buf(id, &id_buf), nt_errstr(status)); return false; } status = locking_tdb_data_fetch(key, talloc_tos(), <db); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_fetch failed: %s\n", nt_errstr(status)); return false; } DBG_DEBUG("num_share_modes=%zu\n", ltdb->num_share_entries); num_share_entries = ltdb->num_share_entries; share_entries = discard_const_p(uint8_t, ltdb->share_entries); i = 0; while (inum_share_entries != 0 ) && (num_share_entries == 0)) { /* * This routine wiped all share entries, let * share_mode_data_store() delete the record */ d->modified = true; } ltdb->num_share_entries = num_share_entries; ltdb->share_entries = share_entries; status = share_mode_data_ltdb_store(d, key, ltdb, NULL, 0); TALLOC_FREE(ltdb); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_ltdb_store failed: %s\n", nt_errstr(status)); return false; } return true; } struct share_mode_count_entries_state { size_t num_share_modes; NTSTATUS status; }; static void share_mode_count_entries_fn( struct server_id exclusive, size_t num_shared, const struct server_id *shared, const uint8_t *data, size_t datalen, void *private_data) { struct share_mode_count_entries_state *state = private_data; struct locking_tdb_data ltdb = { 0 }; bool ok; ok = locking_tdb_data_get(<db, data, datalen); if (!ok) { DBG_WARNING("locking_tdb_data_get failed for %zu\n", datalen); state->status = NT_STATUS_INTERNAL_DB_CORRUPTION; return; } state->num_share_modes = ltdb.num_share_entries; state->status = NT_STATUS_OK; } NTSTATUS share_mode_count_entries(struct file_id fid, size_t *num_share_modes) { struct share_mode_count_entries_state state = { .status = NT_STATUS_NOT_FOUND, }; NTSTATUS status; status = g_lock_dump( lock_ctx, locking_key(&fid), share_mode_count_entries_fn, &state); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("g_lock_dump failed: %s\n", nt_errstr(status)); return status; } if (!NT_STATUS_IS_OK(state.status)) { DBG_DEBUG("share_mode_count_entries_fn failed: %s\n", nt_errstr(state.status)); return state.status; } *num_share_modes = state.num_share_modes; return NT_STATUS_OK; } static bool share_mode_entry_do( struct share_mode_data *d, struct server_id pid, uint64_t share_file_id, void (*fn)(struct share_mode_entry *e, size_t num_share_modes, bool *modified, void *private_data), void *private_data) { TDB_DATA key = locking_key(&d->id); struct locking_tdb_data *ltdb = NULL; size_t idx; bool found = false; bool modified = false; struct share_mode_entry e; uint8_t *e_ptr = NULL; NTSTATUS status; bool ret = false; status = locking_tdb_data_fetch(key, talloc_tos(), <db); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_fetch failed: %s\n", nt_errstr(status)); return false; } DBG_DEBUG("num_share_modes=%zu\n", ltdb->num_share_entries); idx = share_mode_entry_find( ltdb->share_entries, ltdb->num_share_entries, pid, share_file_id, &e, &found); if (!found) { DBG_WARNING("Did not find share mode entry for %"PRIu64"\n", share_file_id); goto done; } if (DEBUGLEVEL>=10) { DBG_DEBUG("entry[%zu]:\n", idx); NDR_PRINT_DEBUG(share_mode_entry, &e); } fn(&e, ltdb->num_share_entries, &modified, private_data); DBG_DEBUG("entry[%zu]: modified=%d, e.stale=%d\n", idx, (int)modified, (int)e.stale); if (!e.stale && !modified) { ret = true; goto done; } e_ptr = discard_const_p(uint8_t, ltdb->share_entries) + idx * SHARE_MODE_ENTRY_SIZE; if (e.stale) { /* * Move the rest down one entry */ size_t behind = ltdb->num_share_entries - idx - 1; if (behind != 0) { memmove(e_ptr, e_ptr + SHARE_MODE_ENTRY_SIZE, behind * SHARE_MODE_ENTRY_SIZE); } ltdb->num_share_entries -= 1; if (ltdb->num_share_entries == 0) { /* * Tell share_mode_lock_destructor() to delete * the whole record */ d->modified = true; } if (DEBUGLEVEL>=10) { DBG_DEBUG("share_mode_entry:\n"); NDR_PRINT_DEBUG(share_mode_entry, &e); } } else { struct share_mode_entry_buf buf; bool ok; if (ltdb->num_share_entries != 1) { /* * Make sure the sorting order stays intact */ SMB_ASSERT(server_id_equal(&e.pid, &pid)); SMB_ASSERT(e.share_file_id == share_file_id); } ok = share_mode_entry_put(&e, &buf); if (!ok) { DBG_DEBUG("share_mode_entry_put failed\n"); goto done; } memcpy(e_ptr, buf.buf, SHARE_MODE_ENTRY_SIZE); } status = share_mode_data_ltdb_store(d, key, ltdb, NULL, 0); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_ltdb_store failed: %s\n", nt_errstr(status)); goto done; } ret = true; done: TALLOC_FREE(ltdb); return ret; } struct del_share_mode_state { bool ok; }; static void del_share_mode_fn( struct share_mode_entry *e, size_t num_share_modes, bool *modified, void *private_data) { struct del_share_mode_state *state = private_data; e->stale = true; state->ok = true; } bool del_share_mode_open_id(struct share_mode_lock *lck, struct server_id open_pid, uint64_t open_file_id) { struct del_share_mode_state state = { .ok = false }; struct share_mode_data *d = NULL; NTSTATUS status; bool ok; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { /* Any error recovery possible here ? */ return false; } ok = share_mode_entry_do( d, open_pid, open_file_id, del_share_mode_fn, &state); if (!ok) { DBG_DEBUG("share_mode_entry_do failed\n"); return false; } if (!state.ok) { DBG_DEBUG("del_share_mode_fn failed\n"); return false; } return true; } bool del_share_mode(struct share_mode_lock *lck, files_struct *fsp) { struct server_id pid = messaging_server_id(fsp->conn->sconn->msg_ctx); bool ok; ok = del_share_mode_open_id(lck, pid, fh_get_gen_id(fsp->fh)); if (!ok) { struct file_id id = share_mode_lock_file_id(lck); struct file_id_buf id_buf; DBG_ERR("share_mode_lock_access_private_data() failed for " "%s %s\n", file_id_str_buf(id, &id_buf), fsp_str_dbg(fsp)); return false; } return true; } struct remove_share_oplock_state { bool ok; }; static void remove_share_oplock_fn( struct share_mode_entry *e, size_t num_share_modes, bool *modified, void *private_data) { struct remove_share_oplock_state *state = private_data; e->op_type = NO_OPLOCK; *modified = true; state->ok = true; } bool remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp) { struct remove_share_oplock_state state = { .ok = false }; struct share_mode_data *d = NULL; NTSTATUS status; bool ok; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { struct file_id id = share_mode_lock_file_id(lck); struct file_id_buf id_buf; /* Any error recovery possible here ? */ DBG_ERR("share_mode_lock_access_private_data() failed for " "%s %s - %s\n", file_id_str_buf(id, &id_buf), fsp_str_dbg(fsp), nt_errstr(status)); return false; } ok = share_mode_entry_do( d, messaging_server_id(fsp->conn->sconn->msg_ctx), fh_get_gen_id(fsp->fh), remove_share_oplock_fn, &state); if (!ok) { DBG_DEBUG("share_mode_entry_do failed\n"); return false; } if (!state.ok) { DBG_DEBUG("remove_share_oplock_fn failed\n"); return false; } if (fsp->oplock_type == LEASE_OPLOCK) { remove_lease_if_stale( lck, fsp_client_guid(fsp), &fsp->lease->lease.lease_key); } share_mode_wakeup_waiters(fsp->file_id); return true; } struct downgrade_share_oplock_state { bool ok; }; static void downgrade_share_oplock_fn( struct share_mode_entry *e, size_t num_share_modes, bool *modified, void *private_data) { struct downgrade_share_oplock_state *state = private_data; e->op_type = LEVEL_II_OPLOCK; *modified = true; state->ok = true; } bool downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp) { struct downgrade_share_oplock_state state = { .ok = false }; struct share_mode_data *d = NULL; NTSTATUS status; bool ok; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { struct file_id id = share_mode_lock_file_id(lck); struct file_id_buf id_buf; /* Any error recovery possible here ? */ DBG_ERR("share_mode_lock_access_private_data() failed for " "%s %s - %s\n", file_id_str_buf(id, &id_buf), fsp_str_dbg(fsp), nt_errstr(status)); return false; } ok = share_mode_entry_do( d, messaging_server_id(fsp->conn->sconn->msg_ctx), fh_get_gen_id(fsp->fh), downgrade_share_oplock_fn, &state); if (!ok) { DBG_DEBUG("share_mode_entry_do failed\n"); return false; } if (!state.ok) { DBG_DEBUG("downgrade_share_oplock_fn failed\n"); return false; } d->flags |= SHARE_MODE_LEASE_READ; d->modified = true; return true; } bool mark_share_mode_disconnected(struct share_mode_lock *lck, struct files_struct *fsp) { struct server_id disconnected_pid = { .pid = 0 }; bool ok; if (fsp->op == NULL) { return false; } if (!fsp->op->global->durable) { return false; } server_id_set_disconnected(&disconnected_pid); ok = reset_share_mode_entry( lck, messaging_server_id(fsp->conn->sconn->msg_ctx), fh_get_gen_id(fsp->fh), disconnected_pid, UINT64_MAX, fsp->op->global->open_persistent_id); return ok; } bool reset_share_mode_entry( struct share_mode_lock *lck, struct server_id old_pid, uint64_t old_share_file_id, struct server_id new_pid, uint64_t new_mid, uint64_t new_share_file_id) { struct file_id id = share_mode_lock_file_id(lck); struct share_mode_data *d = NULL; TDB_DATA key = locking_key(&id); struct locking_tdb_data *ltdb = NULL; struct share_mode_entry e = { .pid.pid = 0 }; struct share_mode_entry_buf e_buf; size_t old_idx; size_t new_idx; bool found; NTSTATUS status; bool ret = false; bool ok; struct file_id_buf id_buf; struct server_id_buf pid_buf1; struct server_id_buf pid_buf2; size_t low_idx1, low_idx2, low_num; size_t mid_idx1, mid_idx2, mid_num; size_t high_idx1, high_idx2, high_num; TDB_DATA dbufs[4]; size_t num_dbufs = 0; status = share_mode_lock_access_private_data(lck, &d); if (!NT_STATUS_IS_OK(status)) { /* Any error recovery possible here ? */ DBG_ERR("share_mode_lock_access_private_data() failed for " "%s - %s\n", file_id_str_buf(id, &id_buf), nt_errstr(status)); return false; } status = locking_tdb_data_fetch(key, talloc_tos(), <db); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("locking_tdb_data_fetch failed: %s\n", nt_errstr(status)); return false; } DBG_DEBUG("%s - num_share_modes=%zu\n", file_id_str_buf(id, &id_buf), ltdb->num_share_entries); new_idx = share_mode_entry_find( ltdb->share_entries, ltdb->num_share_entries, new_pid, new_share_file_id, &e, &found); if (found) { DBG_ERR("%s - num_share_modes=%zu " "found NEW[%s][%"PRIu64"]\n", file_id_str_buf(id, &id_buf), ltdb->num_share_entries, server_id_str_buf(new_pid, &pid_buf2), new_share_file_id); goto done; } old_idx = share_mode_entry_find( ltdb->share_entries, ltdb->num_share_entries, old_pid, old_share_file_id, &e, &found); if (!found) { DBG_WARNING("%s - num_share_modes=%zu " "OLD[%s][%"PRIu64"] not found\n", file_id_str_buf(id, &id_buf), ltdb->num_share_entries, server_id_str_buf(old_pid, &pid_buf1), old_share_file_id); goto done; } DBG_DEBUG("%s - num_share_modes=%zu " "OLD[%s][%"PRIu64"] => idx=%zu " "NEW[%s][%"PRIu64"] => idx=%zu\n", file_id_str_buf(id, &id_buf), ltdb->num_share_entries, server_id_str_buf(old_pid, &pid_buf1), old_share_file_id, old_idx, server_id_str_buf(new_pid, &pid_buf2), new_share_file_id, new_idx); e.pid = new_pid; if (new_mid != UINT64_MAX) { e.op_mid = new_mid; } e.share_file_id = new_share_file_id; ok = share_mode_entry_put(&e, &e_buf); if (!ok) { DBG_WARNING("share_mode_entry_put failed\n"); goto done; } /* * The logic to remove the existing * entry and add the new one at the * same time is a bit complex because * we need to keep the entries sorted. * * The following examples should catch * the corner cases and show that * the {low,mid,high}_{idx1,num} are * correctly calculated and the new * entry is put before or after the mid * elements... * * 1. * 0 * 1 * 2 <- old_idx * new_idx -> 3 * 3 * 4 * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 2 * low_num = low_idx2 - low_idx1; => 2 * * if (new < old) => new; => no * * mid_idx1 = MIN(old_idx+1, new_idx); => 3 * mid_idx2 = MAX(old_idx, new_idx); => 3 * mid_num = mid_idx2 - mid_idx1; => 0 * * if (new >= old) => new; => yes * * high_idx1 = MAX(old_idx+1, new_idx); => 3 * high_idx2 = num_share_entries; => 5 * high_num = high_idx2 - high_idx1 = 2 * * 2. * 0 * 1 * new_idx -> 2 * 2 <- old_idx * 3 * 4 * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 2 * low_num = low_idx2 - low_idx1; => 2 * * if (new < old) => new; => no * * mid_idx1 = MIN(old_idx+1, new_idx); => 2 * mid_idx2 = MAX(old_idx, new_idx); => 2 * mid_num = mid_idx2 - mid_idx1; => 0 * * if (new >= old) => new; => yes * * high_idx1 = MAX(old_idx+1, new_idx); => 3 * high_idx2 = num_share_entries; => 5 * high_num = high_idx2 - high_idx1 = 2 * * 3. * 0 * 1 <- old_idx * 2 * new_idx -> 3 * 3 * 4 * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 1 * low_num = low_idx2 - low_idx1; => 1 * * if (new < old) => new; => no * * mid_idx1 = MIN(old_idx+1, new_idx); => 2 * mid_idx2 = MAX(old_idx, new_idx); => 3 * mid_num = mid_idx2 - mid_idx1; => 1 * * if (new >= old) => new; => yes * * high_idx1 = MAX(old_idx+1, new_idx); => 3 * high_idx2 = num_share_entries; => 5 * high_num = high_idx2 - high_idx1 = 2 * * 4. * 0 * new_idx -> 1 * 1 * 2 * 3 <- old_idx * 4 * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 1 * low_num = low_idx2 - low_idx1; => 1 * * if (new < old) => new; => yes * * mid_idx1 = MIN(old_idx+1, new_idx); => 1 * mid_idx2 = MAX(old_idx, new_idx); => 3 * mid_num = mid_idx2 - mid_idx1; => 2 * * if (new >= old) => new; => no * * high_idx1 = MAX(old_idx+1, new_idx); => 4 * high_idx2 = num_share_entries; => 5 * high_num = high_idx2 - high_idx1 = 1 * * 5. * new_idx -> 0 * 0 * 1 * 2 * 3 * 4 <- old_idx * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 0 * low_num = low_idx2 - low_idx1; => 0 * * if (new < old) => new; => yes * * mid_idx1 = MIN(old_idx+1, new_idx); => 0 * mid_idx2 = MAX(old_idx, new_idx); => 4 * mid_num = mid_idx2 - mid_idx1; => 4 * * if (new >= old) => new; => no * * high_idx1 = MAX(old_idx+1, new_idx); => 5 * high_idx2 = num_share_entries; => 5 * high_num = high_idx2 - high_idx1 = 0 * * 6. * new_idx -> 0 * 0 <- old_idx * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 0 * low_num = low_idx2 - low_idx1; => 0 * * if (new < old) => new; => no * * mid_idx1 = MIN(old_idx+1, new_idx); => 0 * mid_idx2 = MAX(old_idx, new_idx); => 0 * mid_num = mid_idx2 - mid_idx1; => 0 * * if (new >= old) => new; => yes * * high_idx1 = MAX(old_idx+1, new_idx); => 1 * high_idx2 = num_share_entries; => 1 * high_num = high_idx2 - high_idx1 = 0 * * 7. * 0 <- old_idx * new_idx -> 1 * * low_idx1 = 0; * low_idx2 = MIN(old_idx, new_idx); => 0 * low_num = low_idx2 - low_idx1; => 0 * * if (new < old) => new; => no * * mid_idx1 = MIN(old_idx+1, new_idx); => 1 * mid_idx2 = MAX(old_idx, new_idx); => 1 * mid_num = mid_idx2 - mid_idx1; => 0 * * if (new >= old) => new; => yes * * high_idx1 = MAX(old_idx+1, new_idx); => 1 * high_idx2 = num_share_entries; => 1 * high_num = high_idx2 - high_idx1 = 0 */ low_idx1 = 0; low_idx2 = MIN(old_idx, new_idx); low_num = low_idx2 - low_idx1; mid_idx1 = MIN(old_idx+1, new_idx); mid_idx2 = MAX(old_idx, new_idx); mid_num = mid_idx2 - mid_idx1; high_idx1 = MAX(old_idx+1, new_idx); high_idx2 = ltdb->num_share_entries; high_num = high_idx2 - high_idx1; if (low_num != 0) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries) + low_idx1 * SHARE_MODE_ENTRY_SIZE, .dsize = low_num * SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } if (new_idx < old_idx) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = e_buf.buf, .dsize = SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } if (mid_num != 0) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries) + mid_idx1 * SHARE_MODE_ENTRY_SIZE, .dsize = mid_num * SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } if (new_idx >= old_idx) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = e_buf.buf, .dsize = SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } if (high_num != 0) { dbufs[num_dbufs] = (TDB_DATA) { .dptr = discard_const_p(uint8_t, ltdb->share_entries) + high_idx1 * SHARE_MODE_ENTRY_SIZE, .dsize = high_num * SHARE_MODE_ENTRY_SIZE, }; num_dbufs += 1; } { size_t i; for (i=0; ishare_entries = NULL; ltdb->num_share_entries = 0; d->modified = true; status = share_mode_data_ltdb_store(d, key, ltdb, dbufs, num_dbufs); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("share_mode_data_ltdb_store failed: %s\n", nt_errstr(status)); goto done; } ret = true; done: TALLOC_FREE(ltdb); return ret; } struct share_mode_do_locked_vfs_denied_state { struct file_id id; share_mode_do_locked_vfs_fn_t fn; void *private_data; const char *location; NTSTATUS status; }; static void share_mode_do_locked_vfs_denied_fn(struct g_lock_lock_cb_state *glck, void *cb_private) { struct share_mode_do_locked_vfs_denied_state *state = (struct share_mode_do_locked_vfs_denied_state *)cb_private; struct smb_vfs_deny_state vfs_deny = {}; struct share_mode_lock lck; if (glck != NULL) { current_share_mode_glck = glck; } state->status = get_share_mode_lock_internal(state->id, NULL, /* servicepath */ NULL, /* smb_fname */ NULL, /* old_write_time */ &lck); if (!NT_STATUS_IS_OK(state->status)) { DBG_GET_SHARE_MODE_LOCK(state->status, "get_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); if (glck != NULL) { g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; } return; } _smb_vfs_deny_push(&vfs_deny, state->location); state->fn(&lck, state->private_data); _smb_vfs_deny_pop(&vfs_deny, state->location); state->status = put_share_mode_lock_internal(&lck); if (!NT_STATUS_IS_OK(state->status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); smb_panic("put_share_mode_lock_internal failed\n"); return; } if (glck != NULL) { g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; } return; } /** * @brief Run @fn protected with G_LOCK_WRITE in the given file_id * * @fn is NOT allowed to call SMB_VFS_* or similar functions, * which may block for some time in the kernel. * * There must be at least one share_mode_entry, otherwise * NT_STATUS_NOT_FOUND is returned. * * @param[in] id The key for the share_mode record. * @param[in] fn The function to run under the g_lock. * @param[in] private_date A private pointer passed to @fn. */ NTSTATUS _share_mode_do_locked_vfs_denied( struct file_id id, share_mode_do_locked_vfs_fn_t fn, void *private_data, const char *location) { struct share_mode_do_locked_vfs_denied_state state = { .id = id, .fn = fn, .private_data = private_data, .location = location, }; if (share_mode_lock_key_refcount == 0) { TDB_DATA key = locking_key(&id); NTSTATUS status; share_mode_lock_skip_g_lock = true; status = g_lock_lock( lock_ctx, key, G_LOCK_WRITE, (struct timeval) { .tv_sec = 3600 }, share_mode_do_locked_vfs_denied_fn, &state); share_mode_lock_skip_g_lock = false; if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("g_lock_lock failed: %s\n", nt_errstr(status)); return status; } return state.status; } share_mode_do_locked_vfs_denied_fn(NULL, &state); return state.status; } /** * @brief Run @fn protected with G_LOCK_WRITE in the given file_id * * @fn is allowed to call SMB_VFS_* or similar functions, * which may block for some time in the kernel. * * There must be at least one share_mode_entry, otherwise * NT_STATUS_NOT_FOUND is returned. * * @param[in] id The key for the share_mode record. * @param[in] fn The function to run under the g_lock. * @param[in] private_date A private pointer passed to @fn. */ NTSTATUS _share_mode_do_locked_vfs_allowed( struct file_id id, share_mode_do_locked_vfs_fn_t fn, void *private_data, const char *location) { struct share_mode_lock lck; NTSTATUS status; smb_vfs_assert_allowed(); status = get_share_mode_lock_internal(id, NULL, /* servicepath */ NULL, /* smb_fname */ NULL, /* old_write_time */ &lck); if (!NT_STATUS_IS_OK(status)) { DBG_GET_SHARE_MODE_LOCK(status, "get_share_mode_lock_internal failed: %s\n", nt_errstr(status)); return status; } fn(&lck, private_data); status = put_share_mode_lock_internal(&lck); if (!NT_STATUS_IS_OK(status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(status)); smb_panic("put_share_mode_lock_internal failed\n"); return status; } return NT_STATUS_OK; } struct share_mode_entry_prepare_lock_state { struct file_id id; const char *servicepath; const struct smb_filename *smb_fname; const struct timespec *old_write_time; share_mode_entry_prepare_lock_fn_t fn; void *private_data; const char *location; bool keep_locked; struct share_mode_lock *lck; NTSTATUS status; }; static void share_mode_entry_prepare_lock_fn(struct g_lock_lock_cb_state *glck, void *cb_private) { struct share_mode_entry_prepare_lock_state *state = (struct share_mode_entry_prepare_lock_state *)cb_private; struct smb_vfs_deny_state vfs_deny = {}; SMB_ASSERT(glck != NULL); current_share_mode_glck = glck; state->status = get_share_mode_lock_internal(state->id, state->servicepath, state->smb_fname, state->old_write_time, state->lck); if (!NT_STATUS_IS_OK(state->status)) { /* no DBG_GET_SHARE_MODE_LOCK here! */ DBG_ERR("get_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; return; } _smb_vfs_deny_push(&vfs_deny, state->location); state->fn(state->lck, &state->keep_locked, state->private_data); _smb_vfs_deny_pop(&vfs_deny, state->location); if (state->keep_locked) { current_share_mode_glck = NULL; return; } state->status = put_share_mode_lock_internal(state->lck); if (!NT_STATUS_IS_OK(state->status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); smb_panic("put_share_mode_lock_internal failed\n"); return; } g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; return; } NTSTATUS _share_mode_entry_prepare_lock( struct share_mode_entry_prepare_state *prepare_state, struct file_id id, const char *servicepath, const struct smb_filename *smb_fname, const struct timespec *old_write_time, share_mode_entry_prepare_lock_fn_t fn, void *private_data, const char *location) { struct share_mode_entry_prepare_lock_state state = { .id = id, .servicepath = servicepath, .smb_fname = smb_fname, .old_write_time = old_write_time, .fn = fn, .private_data = private_data, .location = location, }; TDB_DATA key = locking_key(&id); NTSTATUS status; SMB_ASSERT(share_mode_lock_key_refcount == 0); SMB_ASSERT(__SHARE_MODE_LOCK_SPACE >= sizeof(struct share_mode_lock)); *prepare_state = (struct share_mode_entry_prepare_state) { .__fid = id, .__lck_ptr = &prepare_state->__lck_space, }; state.lck = prepare_state->__lck_ptr; share_mode_lock_skip_g_lock = true; status = g_lock_lock( lock_ctx, key, G_LOCK_WRITE, (struct timeval) { .tv_sec = 3600 }, share_mode_entry_prepare_lock_fn, &state); share_mode_lock_skip_g_lock = false; if (!state.keep_locked) { prepare_state->__lck_ptr = NULL; } if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("g_lock_lock failed: %s\n", nt_errstr(status)); return status; } return state.status; } struct share_mode_entry_prepare_unlock_state { struct file_id id; share_mode_entry_prepare_unlock_fn_t fn; void *private_data; const char *location; struct share_mode_lock *lck; NTSTATUS status; }; static void share_mode_entry_prepare_unlock_existing_fn( struct share_mode_entry_prepare_unlock_state *state) { if (state->fn != NULL) { struct smb_vfs_deny_state vfs_deny = {}; _smb_vfs_deny_push(&vfs_deny, state->location); state->fn(state->lck, state->private_data); _smb_vfs_deny_pop(&vfs_deny, state->location); } state->status = put_share_mode_lock_internal(state->lck); if (!NT_STATUS_IS_OK(state->status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); smb_panic("put_share_mode_lock_internal failed\n"); return; } return; } static void share_mode_entry_prepare_unlock_relock_fn(struct g_lock_lock_cb_state *glck, void *cb_private) { struct share_mode_entry_prepare_unlock_state *state = (struct share_mode_entry_prepare_unlock_state *)cb_private; struct smb_vfs_deny_state vfs_deny = {}; SMB_ASSERT(glck != NULL); current_share_mode_glck = glck; state->status = get_share_mode_lock_internal(state->id, NULL, /* servicepath */ NULL, /* smb_fname */ NULL, /* old_write_time */ state->lck); if (!NT_STATUS_IS_OK(state->status)) { /* no DBG_GET_SHARE_MODE_LOCK here! */ DBG_ERR("get_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; return; } _smb_vfs_deny_push(&vfs_deny, state->location); state->fn(state->lck, state->private_data); _smb_vfs_deny_pop(&vfs_deny, state->location); state->status = put_share_mode_lock_internal(state->lck); if (!NT_STATUS_IS_OK(state->status)) { DBG_ERR("put_share_mode_lock_internal failed: %s\n", nt_errstr(state->status)); smb_panic("put_share_mode_lock_internal failed\n"); return; } g_lock_lock_cb_unlock(glck); current_share_mode_glck = NULL; return; } NTSTATUS _share_mode_entry_prepare_unlock( struct share_mode_entry_prepare_state *prepare_state, share_mode_entry_prepare_unlock_fn_t fn, void *private_data, const char *location) { struct share_mode_entry_prepare_unlock_state state = { .id = prepare_state->__fid, .fn = fn, .private_data = private_data, .location = location, }; TDB_DATA key = locking_key(&prepare_state->__fid); NTSTATUS status; if (prepare_state->__lck_ptr != NULL) { /* * With an existing lock, we just run the unlock prepare * function following by the unlock. */ SMB_ASSERT(share_mode_lock_key_refcount == 1); state.lck = prepare_state->__lck_ptr; prepare_state->__lck_ptr = NULL; share_mode_entry_prepare_unlock_existing_fn(&state); return state.status; } /* * No existing lock, which means * _share_mode_entry_prepare_lock() didn't steal * the lock... */ SMB_ASSERT(share_mode_lock_key_refcount == 0); if (fn == NULL) { /* * Without an existing lock and without * a prepare function there's nothing to * do... */ return NT_STATUS_OK; } /* * In order to run the unlock prepare function * we need to relock the entry. */ state.lck = &prepare_state->__lck_space; share_mode_lock_skip_g_lock = true; status = g_lock_lock( lock_ctx, key, G_LOCK_WRITE, (struct timeval) { .tv_sec = 3600 }, share_mode_entry_prepare_unlock_relock_fn, &state); share_mode_lock_skip_g_lock = false; if (!NT_STATUS_IS_OK(status)) { DBG_ERR("g_lock_lock failed: %s\n", nt_errstr(status)); return status; } return state.status; }