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-rw-r--r--source4/ntvfs/common/notify.c687
1 files changed, 687 insertions, 0 deletions
diff --git a/source4/ntvfs/common/notify.c b/source4/ntvfs/common/notify.c
new file mode 100644
index 0000000..a434fab
--- /dev/null
+++ b/source4/ntvfs/common/notify.c
@@ -0,0 +1,687 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ Copyright (C) Andrew Tridgell 2006
+
+ 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/>.
+*/
+
+/*
+ this is the change notify database. It implements mechanisms for
+ storing current change notify waiters in a tdb, and checking if a
+ given event matches any of the stored notify waiiters.
+*/
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "messaging/messaging.h"
+#include "lib/messaging/irpc.h"
+#include "librpc/gen_ndr/ndr_notify.h"
+#include "../lib/util/dlinklist.h"
+#include "ntvfs/common/ntvfs_common.h"
+#include "ntvfs/sysdep/sys_notify.h"
+#include "cluster/cluster.h"
+#include "param/param.h"
+#include "lib/util/tsort.h"
+#include "lib/dbwrap/dbwrap.h"
+#include "../lib/util/util_tdb.h"
+
+struct notify_context {
+ struct db_context *db;
+ struct server_id server;
+ struct imessaging_context *imessaging_ctx;
+ struct notify_list *list;
+ struct notify_array *array;
+ int64_t seqnum;
+ struct sys_notify_context *sys_notify_ctx;
+};
+
+
+struct notify_list {
+ struct notify_list *next, *prev;
+ void *private_data;
+ void (*callback)(void *, const struct notify_event *);
+ void *sys_notify_handle;
+ int depth;
+};
+
+#define NOTIFY_KEY "notify array"
+
+#define NOTIFY_ENABLE "notify:enable"
+#define NOTIFY_ENABLE_DEFAULT true
+
+static NTSTATUS notify_remove_all(struct notify_context *notify);
+static void notify_handler(struct imessaging_context *msg_ctx,
+ void *private_data,
+ uint32_t msg_type,
+ struct server_id server_id,
+ size_t num_fds,
+ int *fds,
+ DATA_BLOB *data);
+
+/*
+ destroy the notify context
+*/
+static int notify_destructor(struct notify_context *notify)
+{
+ imessaging_deregister(notify->imessaging_ctx, MSG_PVFS_NOTIFY, notify);
+ notify_remove_all(notify);
+ return 0;
+}
+
+/*
+ Open up the notify.tdb database. You should close it down using
+ talloc_free(). We need the imessaging_ctx to allow for notifications
+ via internal messages
+*/
+struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
+ struct imessaging_context *imessaging_ctx,
+ struct loadparm_context *lp_ctx,
+ struct tevent_context *ev,
+ struct share_config *scfg)
+{
+ struct notify_context *notify;
+
+ if (share_bool_option(scfg, NOTIFY_ENABLE, NOTIFY_ENABLE_DEFAULT) != true) {
+ return NULL;
+ }
+
+ if (ev == NULL) {
+ return NULL;
+ }
+
+ notify = talloc(mem_ctx, struct notify_context);
+ if (notify == NULL) {
+ return NULL;
+ }
+
+ notify->db = cluster_db_tmp_open(notify, lp_ctx, "notify", TDB_SEQNUM);
+ if (notify->db == NULL) {
+ talloc_free(notify);
+ return NULL;
+ }
+
+ notify->server = server;
+ notify->imessaging_ctx = imessaging_ctx;
+ notify->list = NULL;
+ notify->array = NULL;
+ notify->seqnum = dbwrap_get_seqnum(notify->db);
+
+ talloc_set_destructor(notify, notify_destructor);
+
+ /* register with the messaging subsystem for the notify
+ message type */
+ imessaging_register(notify->imessaging_ctx, notify,
+ MSG_PVFS_NOTIFY, notify_handler);
+
+ notify->sys_notify_ctx = sys_notify_context_create(scfg, notify, ev);
+
+ return notify;
+}
+
+
+/*
+ lock the notify db
+*/
+static struct db_record *notify_lock(struct notify_context *notify)
+{
+ TDB_DATA key = string_term_tdb_data(NOTIFY_KEY);
+
+ return dbwrap_fetch_locked(notify->db, notify, key);
+}
+
+static void notify_unlock(struct db_record *lock)
+{
+ talloc_free(lock);
+}
+
+/*
+ load the notify array
+*/
+static NTSTATUS notify_load(struct notify_context *notify)
+{
+ TDB_DATA dbuf;
+ DATA_BLOB blob;
+ enum ndr_err_code ndr_err;
+ int seqnum;
+ NTSTATUS status;
+
+ seqnum = dbwrap_get_seqnum(notify->db);
+
+ if (seqnum == notify->seqnum && notify->array != NULL) {
+ return NT_STATUS_OK;
+ }
+
+ notify->seqnum = seqnum;
+
+ talloc_free(notify->array);
+ notify->array = talloc_zero(notify, struct notify_array);
+ NT_STATUS_HAVE_NO_MEMORY(notify->array);
+
+ status = dbwrap_fetch_bystring(notify->db, notify, NOTIFY_KEY, &dbuf);
+ if (!NT_STATUS_IS_OK(status)) {
+ return NT_STATUS_OK;
+ }
+
+ blob.data = dbuf.dptr;
+ blob.length = dbuf.dsize;
+
+ ndr_err = ndr_pull_struct_blob(&blob, notify->array, notify->array,
+ (ndr_pull_flags_fn_t)ndr_pull_notify_array);
+ talloc_free(dbuf.dptr);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return ndr_map_error2ntstatus(ndr_err);
+ }
+
+ return NT_STATUS_OK;
+}
+
+/*
+ compare notify entries for sorting
+*/
+static int notify_compare(const void *p1, const void *p2)
+{
+ const struct notify_entry *e1 = p1, *e2 = p2;
+ return strcmp(e1->path, e2->path);
+}
+
+/*
+ save the notify array
+*/
+static NTSTATUS notify_save(struct notify_context *notify)
+{
+ TDB_DATA dbuf;
+ DATA_BLOB blob;
+ enum ndr_err_code ndr_err;
+ TALLOC_CTX *tmp_ctx;
+ NTSTATUS status;
+
+ /* if possible, remove some depth arrays */
+ while (notify->array->num_depths > 0 &&
+ notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
+ notify->array->num_depths--;
+ }
+
+ /* we might just be able to delete the record */
+ if (notify->array->num_depths == 0) {
+ return dbwrap_delete_bystring(notify->db, NOTIFY_KEY);
+ }
+
+ tmp_ctx = talloc_new(notify);
+ NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
+
+ ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, notify->array,
+ (ndr_push_flags_fn_t)ndr_push_notify_array);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ talloc_free(tmp_ctx);
+ return ndr_map_error2ntstatus(ndr_err);
+ }
+
+ dbuf.dptr = blob.data;
+ dbuf.dsize = blob.length;
+
+ status = dbwrap_store_bystring(notify->db, NOTIFY_KEY, dbuf,
+ TDB_REPLACE);
+ talloc_free(tmp_ctx);
+ return status;
+}
+
+
+/*
+ handle incoming notify messages
+*/
+static void notify_handler(struct imessaging_context *msg_ctx,
+ void *private_data,
+ uint32_t msg_type,
+ struct server_id server_id,
+ size_t num_fds,
+ int *fds,
+ DATA_BLOB *data)
+{
+ struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
+ enum ndr_err_code ndr_err;
+ struct notify_event ev;
+ TALLOC_CTX *tmp_ctx = talloc_new(notify);
+ struct notify_list *listel;
+
+ if (num_fds != 0) {
+ DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
+ return;
+ }
+
+ if (tmp_ctx == NULL) {
+ return;
+ }
+
+ ndr_err = ndr_pull_struct_blob(data, tmp_ctx, &ev,
+ (ndr_pull_flags_fn_t)ndr_pull_notify_event);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ talloc_free(tmp_ctx);
+ return;
+ }
+
+ for (listel=notify->list;listel;listel=listel->next) {
+ if (listel->private_data == ev.private_data) {
+ listel->callback(listel->private_data, &ev);
+ break;
+ }
+ }
+
+ talloc_free(tmp_ctx);
+}
+
+/*
+ callback from sys_notify telling us about changes from the OS
+*/
+static void sys_notify_callback(struct sys_notify_context *ctx,
+ void *ptr, struct notify_event *ev)
+{
+ struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
+ ev->private_data = listel;
+ listel->callback(listel->private_data, ev);
+}
+
+/*
+ add an entry to the notify array
+*/
+static NTSTATUS notify_add_array(struct notify_context *notify, struct notify_entry *e,
+ void *private_data, int depth)
+{
+ int i;
+ struct notify_depth *d;
+ struct notify_entry *ee;
+
+ /* possibly expand the depths array */
+ if (depth >= notify->array->num_depths) {
+ d = talloc_realloc(notify->array, notify->array->depth,
+ struct notify_depth, depth+1);
+ NT_STATUS_HAVE_NO_MEMORY(d);
+ for (i=notify->array->num_depths;i<=depth;i++) {
+ ZERO_STRUCT(d[i]);
+ }
+ notify->array->depth = d;
+ notify->array->num_depths = depth+1;
+ }
+ d = &notify->array->depth[depth];
+
+ /* expand the entries array */
+ ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
+ d->num_entries+1);
+ NT_STATUS_HAVE_NO_MEMORY(ee);
+ d->entries = ee;
+
+ d->entries[d->num_entries] = *e;
+ d->entries[d->num_entries].private_data = private_data;
+ d->entries[d->num_entries].server = notify->server;
+ d->entries[d->num_entries].path_len = strlen(e->path);
+ d->num_entries++;
+
+ d->max_mask |= e->filter;
+ d->max_mask_subdir |= e->subdir_filter;
+
+ TYPESAFE_QSORT(d->entries, d->num_entries, notify_compare);
+
+ /* recalculate the maximum masks */
+ d->max_mask = 0;
+ d->max_mask_subdir = 0;
+
+ for (i=0;i<d->num_entries;i++) {
+ d->max_mask |= d->entries[i].filter;
+ d->max_mask_subdir |= d->entries[i].subdir_filter;
+ }
+
+ return notify_save(notify);
+}
+
+/*
+ add a notify watch. This is called when a notify is first setup on a open
+ directory handle.
+*/
+NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
+ void (*callback)(void *, const struct notify_event *),
+ void *private_data)
+{
+ struct notify_entry e = *e0;
+ NTSTATUS status;
+ char *tmp_path = NULL;
+ struct notify_list *listel;
+ size_t len;
+ int depth;
+ struct db_record *locked;
+
+ /* see if change notify is enabled at all */
+ if (notify == NULL) {
+ return NT_STATUS_NOT_IMPLEMENTED;
+ }
+
+ locked = notify_lock(notify);
+ if (!locked) {
+ return NT_STATUS_INTERNAL_DB_CORRUPTION;
+ }
+
+ status = notify_load(notify);
+ if (!NT_STATUS_IS_OK(status)) {
+ goto done;
+ }
+
+ /* cope with /. on the end of the path */
+ len = strlen(e.path);
+ if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
+ tmp_path = talloc_strndup(notify, e.path, len-2);
+ if (tmp_path == NULL) {
+ status = NT_STATUS_NO_MEMORY;
+ goto done;
+ }
+ e.path = tmp_path;
+ }
+
+ depth = count_chars(e.path, '/');
+
+ listel = talloc_zero(notify, struct notify_list);
+ if (listel == NULL) {
+ status = NT_STATUS_NO_MEMORY;
+ goto done;
+ }
+
+ listel->private_data = private_data;
+ listel->callback = callback;
+ listel->depth = depth;
+ DLIST_ADD(notify->list, listel);
+
+ /* ignore failures from sys_notify */
+ if (notify->sys_notify_ctx != NULL) {
+ /*
+ this call will modify e.filter and e.subdir_filter
+ to remove bits handled by the backend
+ */
+ status = sys_notify_watch(notify->sys_notify_ctx, &e,
+ sys_notify_callback, listel,
+ &listel->sys_notify_handle);
+ if (NT_STATUS_IS_OK(status)) {
+ talloc_steal(listel, listel->sys_notify_handle);
+ }
+ }
+
+ /* if the system notify handler couldn't handle some of the
+ filter bits, or couldn't handle a request for recursion
+ then we need to install it in the array used for the
+ intra-samba notify handling */
+ if (e.filter != 0 || e.subdir_filter != 0) {
+ status = notify_add_array(notify, &e, private_data, depth);
+ }
+
+done:
+ notify_unlock(locked);
+ talloc_free(tmp_path);
+
+ return status;
+}
+
+/*
+ remove a notify watch. Called when the directory handle is closed
+*/
+NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
+{
+ NTSTATUS status;
+ struct notify_list *listel;
+ int i, depth;
+ struct notify_depth *d;
+ struct db_record *locked;
+
+ /* see if change notify is enabled at all */
+ if (notify == NULL) {
+ return NT_STATUS_NOT_IMPLEMENTED;
+ }
+
+ for (listel=notify->list;listel;listel=listel->next) {
+ if (listel->private_data == private_data) {
+ DLIST_REMOVE(notify->list, listel);
+ break;
+ }
+ }
+ if (listel == NULL) {
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ }
+
+ depth = listel->depth;
+
+ talloc_free(listel);
+
+ locked = notify_lock(notify);
+ if (!locked) {
+ return NT_STATUS_INTERNAL_DB_CORRUPTION;
+ }
+
+ status = notify_load(notify);
+ if (!NT_STATUS_IS_OK(status)) {
+ notify_unlock(locked);
+ return status;
+ }
+
+ if (depth >= notify->array->num_depths) {
+ notify_unlock(locked);
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ }
+
+ /* we only have to search at the depth of this element */
+ d = &notify->array->depth[depth];
+
+ for (i=0;i<d->num_entries;i++) {
+ if (private_data == d->entries[i].private_data &&
+ cluster_id_equal(&notify->server, &d->entries[i].server)) {
+ break;
+ }
+ }
+ if (i == d->num_entries) {
+ notify_unlock(locked);
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ }
+
+ if (i < d->num_entries-1) {
+ memmove(&d->entries[i], &d->entries[i+1],
+ sizeof(d->entries[i])*(d->num_entries-(i+1)));
+ }
+ d->num_entries--;
+
+ status = notify_save(notify);
+
+ notify_unlock(locked);
+
+ return status;
+}
+
+/*
+ remove all notify watches for this messaging server
+*/
+static NTSTATUS notify_remove_all(struct notify_context *notify)
+{
+ NTSTATUS status;
+ int i, depth, del_count=0;
+ struct db_record *locked;
+
+ if (notify->list == NULL) {
+ return NT_STATUS_OK;
+ }
+
+ locked = notify_lock(notify);
+ if (!locked) {
+ return NT_STATUS_INTERNAL_DB_CORRUPTION;
+ }
+
+ status = notify_load(notify);
+ if (!NT_STATUS_IS_OK(status)) {
+ notify_unlock(locked);
+ return status;
+ }
+
+ /* we have to search for all entries across all depths, looking for matches
+ for our server id */
+ for (depth=0;depth<notify->array->num_depths;depth++) {
+ struct notify_depth *d = &notify->array->depth[depth];
+ for (i=0;i<d->num_entries;i++) {
+ if (cluster_id_equal(&notify->server, &d->entries[i].server)) {
+ if (i < d->num_entries-1) {
+ memmove(&d->entries[i], &d->entries[i+1],
+ sizeof(d->entries[i])*(d->num_entries-(i+1)));
+ }
+ i--;
+ d->num_entries--;
+ del_count++;
+ }
+ }
+ }
+
+ if (del_count > 0) {
+ status = notify_save(notify);
+ }
+
+ notify_unlock(locked);
+
+ return status;
+}
+
+
+/*
+ send a notify message to another messaging server
+*/
+static void notify_send(struct notify_context *notify, struct notify_entry *e,
+ const char *path, uint32_t action)
+{
+ struct notify_event ev;
+ DATA_BLOB data;
+ NTSTATUS status;
+ enum ndr_err_code ndr_err;
+ TALLOC_CTX *tmp_ctx;
+
+ ev.action = action;
+ ev.dir = discard_const_p(char, "");
+ ev.path = path;
+ ev.private_data = e->private_data;
+
+ tmp_ctx = talloc_new(notify);
+
+ ndr_err = ndr_push_struct_blob(&data, tmp_ctx, &ev, (ndr_push_flags_fn_t)ndr_push_notify_event);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ talloc_free(tmp_ctx);
+ return;
+ }
+
+ status = imessaging_send(notify->imessaging_ctx, e->server,
+ MSG_PVFS_NOTIFY, &data);
+ if (!NT_STATUS_IS_OK(status)) {
+ talloc_free(tmp_ctx);
+ return;
+ }
+
+ talloc_free(tmp_ctx);
+}
+
+
+/*
+ trigger a notify message for anyone waiting on a matching event
+
+ This function is called a lot, and needs to be very fast. The unusual data structure
+ and traversal is designed to be fast in the average case, even for large numbers of
+ notifies
+*/
+void notify_trigger(struct notify_context *notify,
+ uint32_t action, uint32_t filter, const char *path)
+{
+ NTSTATUS status;
+ int depth;
+ const char *p, *next_p;
+
+ /* see if change notify is enabled at all */
+ if (notify == NULL) {
+ return;
+ }
+
+ status = notify_load(notify);
+ if (!NT_STATUS_IS_OK(status)) {
+ return;
+ }
+
+ /* loop along the given path, working with each directory depth separately */
+ for (depth=0,p=path;
+ p && depth < notify->array->num_depths;
+ p=next_p,depth++) {
+ int p_len = p - path;
+ int min_i, max_i, i;
+ struct notify_depth *d = &notify->array->depth[depth];
+ next_p = strchr(p+1, '/');
+
+ /* see if there are any entries at this depth */
+ if (d->num_entries == 0) continue;
+
+ /* try to skip based on the maximum mask. If next_p is
+ NULL then we know it will be a 'this directory'
+ match, otherwise it must be a subdir match */
+ if (next_p != NULL) {
+ if (0 == (filter & d->max_mask_subdir)) {
+ continue;
+ }
+ } else {
+ if (0 == (filter & d->max_mask)) {
+ continue;
+ }
+ }
+
+ /* we know there is an entry here worth looking
+ for. Use a bisection search to find the first entry
+ with a matching path */
+ min_i = 0;
+ max_i = d->num_entries-1;
+
+ while (min_i < max_i) {
+ struct notify_entry *e;
+ int cmp;
+ i = (min_i+max_i)/2;
+ e = &d->entries[i];
+ cmp = strncmp(path, e->path, p_len);
+ if (cmp == 0) {
+ if (p_len == e->path_len) {
+ max_i = i;
+ } else {
+ max_i = i-1;
+ }
+ } else if (cmp < 0) {
+ max_i = i-1;
+ } else {
+ min_i = i+1;
+ }
+ }
+
+ if (min_i != max_i) {
+ /* none match */
+ continue;
+ }
+
+ /* we now know that the entries start at min_i */
+ for (i=min_i;i<d->num_entries;i++) {
+ struct notify_entry *e = &d->entries[i];
+ if (p_len != e->path_len ||
+ strncmp(path, e->path, p_len) != 0) break;
+ if (next_p != NULL) {
+ if (0 == (filter & e->subdir_filter)) {
+ continue;
+ }
+ } else {
+ if (0 == (filter & e->filter)) {
+ continue;
+ }
+ }
+ notify_send(notify, e, path + e->path_len + 1, action);
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 13:33:08 +0000