/*
- * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * 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, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _LGPL_SOURCE
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/macros.h>
#include <lttng/condition/condition.h>
-#include <lttng/action/action.h>
+#include <lttng/action/action-internal.h>
#include <lttng/notification/notification-internal.h>
#include <lttng/condition/condition-internal.h>
#include <lttng/condition/buffer-usage-internal.h>
#include <lttng/condition/session-consumed-size-internal.h>
+#include <lttng/condition/session-rotation-internal.h>
#include <lttng/notification/channel-internal.h>
#include <time.h>
#define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP)
#define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT)
+enum lttng_object_type {
+ LTTNG_OBJECT_TYPE_UNKNOWN,
+ LTTNG_OBJECT_TYPE_NONE,
+ LTTNG_OBJECT_TYPE_CHANNEL,
+ LTTNG_OBJECT_TYPE_SESSION,
+};
+
struct lttng_trigger_list_element {
- struct lttng_trigger *trigger;
+ /* No ownership of the trigger object is assumed. */
+ const struct lttng_trigger *trigger;
struct cds_list_head node;
};
struct lttng_channel_trigger_list {
struct channel_key channel_key;
+ /* List of struct lttng_trigger_list_element. */
struct cds_list_head list;
+ /* Node in the channel_triggers_ht */
struct cds_lfht_node channel_triggers_ht_node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
+};
+
+/*
+ * List of triggers applying to a given session.
+ *
+ * See:
+ * - lttng_session_trigger_list_create()
+ * - lttng_session_trigger_list_build()
+ * - lttng_session_trigger_list_destroy()
+ * - lttng_session_trigger_list_add()
+ */
+struct lttng_session_trigger_list {
+ /*
+ * Not owned by this; points to the session_info structure's
+ * session name.
+ */
+ const char *session_name;
+ /* List of struct lttng_trigger_list_element. */
+ struct cds_list_head list;
+ /* Node in the session_triggers_ht */
+ struct cds_lfht_node session_triggers_ht_node;
+ /*
+ * Weak reference to the notification system's session triggers
+ * hashtable.
+ *
+ * The session trigger list structure structure is owned by
+ * the session's session_info.
+ *
+ * The session_info is kept alive the the channel_infos holding a
+ * reference to it (reference counting). When those channels are
+ * destroyed (at runtime or on teardown), the reference they hold
+ * to the session_info are released. On destruction of session_info,
+ * session_info_destroy() will remove the list of triggers applying
+ * to this session from the notification system's state.
+ *
+ * This implies that the session_triggers_ht must be destroyed
+ * after the channels.
+ */
+ struct cds_lfht *session_triggers_ht;
+ /* Used for delayed RCU reclaim. */
+ struct rcu_head rcu_node;
};
struct lttng_trigger_ht_element {
struct lttng_trigger *trigger;
struct cds_lfht_node node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct lttng_condition_list_element {
struct cds_list_head node;
};
+/*
+ * Thread safety of notification_client and notification_client_list.
+ *
+ * The notification thread (main thread) and the action executor
+ * interact through client lists. Hence, when the action executor
+ * thread looks-up the list of clients subscribed to a given
+ * condition, it will acquire a reference to the list and lock it
+ * while attempting to communicate with the various clients.
+ *
+ * It is not necessary to reference-count clients as they are guaranteed
+ * to be 'alive' if they are present in a list and that list is locked. Indeed,
+ * removing references to the client from those subscription lists is part of
+ * the work performed on destruction of a client.
+ *
+ * No provision for other access scenarios are taken into account;
+ * this is the bare minimum to make these accesses safe and the
+ * notification thread's state is _not_ "thread-safe" in any general
+ * sense.
+ */
struct notification_client_list {
- struct lttng_trigger *trigger;
+ pthread_mutex_t lock;
+ struct urcu_ref ref;
+ const struct lttng_trigger *trigger;
struct cds_list_head list;
- struct cds_lfht_node notification_trigger_ht_node;
+ /* Weak reference to container. */
+ struct cds_lfht *notification_trigger_clients_ht;
+ struct cds_lfht_node notification_trigger_clients_ht_node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct notification_client {
+ /* Nests within the notification_client_list lock. */
+ pthread_mutex_t lock;
+ notification_client_id id;
int socket;
/* Client protocol version. */
uint8_t major, minor;
*/
struct cds_list_head condition_list;
struct cds_lfht_node client_socket_ht_node;
+ struct cds_lfht_node client_id_ht_node;
struct {
+ /*
+ * If a client's communication is inactive, it means that a
+ * fatal error has occurred (could be either a protocol error or
+ * the socket API returned a fatal error). No further
+ * communication should be attempted; the client is queued for
+ * clean-up.
+ */
+ bool active;
struct {
/*
* During the reception of a message, the reception
struct lttng_dynamic_buffer buffer;
} outbound;
} communication;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct channel_state_sample {
uint64_t highest_usage;
uint64_t lowest_usage;
uint64_t channel_total_consumed;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
static unsigned long hash_channel_key(struct channel_key *key);
-static int evaluate_condition(const struct lttng_condition *condition,
+static int evaluate_buffer_condition(const struct lttng_condition *condition,
struct lttng_evaluation **evaluation,
const struct notification_thread_state *state,
const struct channel_state_sample *previous_sample,
uint64_t latest_session_consumed_total,
struct channel_info *channel_info);
static
-int send_evaluation_to_clients(struct lttng_trigger *trigger,
- struct lttng_evaluation *evaluation,
+int send_evaluation_to_clients(const struct lttng_trigger *trigger,
+ const struct lttng_evaluation *evaluation,
struct notification_client_list *client_list,
struct notification_thread_state *state,
uid_t channel_uid, gid_t channel_gid);
+/* session_info API */
static
void session_info_destroy(void *_data);
static
void session_info_put(struct session_info *session_info);
static
struct session_info *session_info_create(const char *name,
- uid_t uid, gid_t gid);
+ uid_t uid, gid_t gid,
+ struct lttng_session_trigger_list *trigger_list,
+ struct cds_lfht *sessions_ht);
static
void session_info_add_channel(struct session_info *session_info,
struct channel_info *channel_info);
void session_info_remove_channel(struct session_info *session_info,
struct channel_info *channel_info);
+/* lttng_session_trigger_list API */
+static
+struct lttng_session_trigger_list *lttng_session_trigger_list_create(
+ const char *session_name,
+ struct cds_lfht *session_triggers_ht);
+static
+struct lttng_session_trigger_list *lttng_session_trigger_list_build(
+ const struct notification_thread_state *state,
+ const char *session_name);
+static
+void lttng_session_trigger_list_destroy(
+ struct lttng_session_trigger_list *list);
+static
+int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
+ const struct lttng_trigger *trigger);
+
+
static
-int match_client(struct cds_lfht_node *node, const void *key)
+int match_client_socket(struct cds_lfht_node *node, const void *key)
{
/* This double-cast is intended to supress pointer-to-cast warning. */
- int socket = (int) (intptr_t) key;
- struct notification_client *client;
+ const int socket = (int) (intptr_t) key;
+ const struct notification_client *client = caa_container_of(node,
+ struct notification_client, client_socket_ht_node);
- client = caa_container_of(node, struct notification_client,
- client_socket_ht_node);
+ return client->socket == socket;
+}
+
+static
+int match_client_id(struct cds_lfht_node *node, const void *key)
+{
+ /* This double-cast is intended to supress pointer-to-cast warning. */
+ const notification_client_id id = *((notification_client_id *) key);
+ const struct notification_client *client = caa_container_of(
+ node, struct notification_client, client_id_ht_node);
- return !!(client->socket == socket);
+ return client->id == id;
}
static
(channel_key->domain == trigger_list->channel_key.domain));
}
+static
+int match_session_trigger_list(struct cds_lfht_node *node, const void *key)
+{
+ const char *session_name = (const char *) key;
+ struct lttng_session_trigger_list *trigger_list;
+
+ trigger_list = caa_container_of(node, struct lttng_session_trigger_list,
+ session_triggers_ht_node);
+
+ return !!(strcmp(trigger_list->session_name, session_name) == 0);
+}
+
static
int match_channel_state_sample(struct cds_lfht_node *node, const void *key)
{
}
static
-int match_client_list(struct cds_lfht_node *node, const void *key)
+int match_client_list_condition(struct cds_lfht_node *node, const void *key)
{
- struct lttng_trigger *trigger_key = (struct lttng_trigger *) key;
+ struct lttng_condition *condition_key = (struct lttng_condition *) key;
struct notification_client_list *client_list;
- struct lttng_condition *condition;
- struct lttng_condition *condition_key = lttng_trigger_get_condition(
- trigger_key);
+ const struct lttng_condition *condition;
assert(condition_key);
client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
- condition = lttng_trigger_get_condition(client_list->trigger);
+ notification_trigger_clients_ht_node);
+ condition = lttng_trigger_get_const_condition(client_list->trigger);
return !!lttng_condition_is_equal(condition_key, condition);
}
static
-int match_client_list_condition(struct cds_lfht_node *node, const void *key)
+int match_session(struct cds_lfht_node *node, const void *key)
{
- struct lttng_condition *condition_key = (struct lttng_condition *) key;
- struct notification_client_list *client_list;
- struct lttng_condition *condition;
-
- assert(condition_key);
-
- client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
- condition = lttng_trigger_get_condition(client_list->trigger);
+ const char *name = key;
+ struct session_info *session_info = caa_container_of(
+ node, struct session_info, sessions_ht_node);
- return !!lttng_condition_is_equal(condition_key, condition);
+ return !strcmp(session_info->name, name);
}
static
unsigned long lttng_condition_buffer_usage_hash(
- struct lttng_condition *_condition)
+ const struct lttng_condition *_condition)
{
- unsigned long hash = 0;
+ unsigned long hash;
+ unsigned long condition_type;
struct lttng_condition_buffer_usage *condition;
condition = container_of(_condition,
struct lttng_condition_buffer_usage, parent);
+ condition_type = (unsigned long) condition->parent.type;
+ hash = hash_key_ulong((void *) condition_type, lttng_ht_seed);
if (condition->session_name) {
hash ^= hash_key_str(condition->session_name, lttng_ht_seed);
}
static
unsigned long lttng_condition_session_consumed_size_hash(
- struct lttng_condition *_condition)
+ const struct lttng_condition *_condition)
{
- unsigned long hash = 0;
+ unsigned long hash;
+ unsigned long condition_type =
+ (unsigned long) LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE;
struct lttng_condition_session_consumed_size *condition;
uint64_t val;
condition = container_of(_condition,
struct lttng_condition_session_consumed_size, parent);
+ hash = hash_key_ulong((void *) condition_type, lttng_ht_seed);
if (condition->session_name) {
hash ^= hash_key_str(condition->session_name, lttng_ht_seed);
}
return hash;
}
+static
+unsigned long lttng_condition_session_rotation_hash(
+ const struct lttng_condition *_condition)
+{
+ unsigned long hash, condition_type;
+ struct lttng_condition_session_rotation *condition;
+
+ condition = container_of(_condition,
+ struct lttng_condition_session_rotation, parent);
+ condition_type = (unsigned long) condition->parent.type;
+ hash = hash_key_ulong((void *) condition_type, lttng_ht_seed);
+ assert(condition->session_name);
+ hash ^= hash_key_str(condition->session_name, lttng_ht_seed);
+ return hash;
+}
+
/*
* The lttng_condition hashing code is kept in this file (rather than
* condition.c) since it makes use of GPLv2 code (hashtable utils), which we
* don't want to link in liblttng-ctl.
*/
static
-unsigned long lttng_condition_hash(struct lttng_condition *condition)
+unsigned long lttng_condition_hash(const struct lttng_condition *condition)
{
switch (condition->type) {
case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
return lttng_condition_buffer_usage_hash(condition);
case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
return lttng_condition_session_consumed_size_hash(condition);
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ return lttng_condition_session_rotation_hash(condition);
default:
ERR("[notification-thread] Unexpected condition type caught");
abort();
return key_hash ^ domain_hash;
}
+static
+unsigned long hash_client_socket(int socket)
+{
+ return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed);
+}
+
+static
+unsigned long hash_client_id(notification_client_id id)
+{
+ return hash_key_u64(&id, lttng_ht_seed);
+}
+
+/*
+ * Get the type of object to which a given condition applies. Bindings let
+ * the notification system evaluate a trigger's condition when a given
+ * object's state is updated.
+ *
+ * For instance, a condition bound to a channel will be evaluated everytime
+ * the channel's state is changed by a channel monitoring sample.
+ */
+static
+enum lttng_object_type get_condition_binding_object(
+ const struct lttng_condition *condition)
+{
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+ case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+ return LTTNG_OBJECT_TYPE_CHANNEL;
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ return LTTNG_OBJECT_TYPE_SESSION;
+ default:
+ return LTTNG_OBJECT_TYPE_UNKNOWN;
+ }
+}
+
+static
+void free_channel_info_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct channel_info, rcu_node));
+}
+
static
void channel_info_destroy(struct channel_info *channel_info)
{
if (channel_info->name) {
free(channel_info->name);
}
- free(channel_info);
+ call_rcu(&channel_info->rcu_node, free_channel_info_rcu);
+}
+
+static
+void free_session_info_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct session_info, rcu_node));
}
/* Don't call directly, use the ref-counting mechanism. */
if (session_info->channel_infos_ht) {
ret = cds_lfht_destroy(session_info->channel_infos_ht, NULL);
if (ret) {
- ERR("Channel information hash table destroy");
+ ERR("[notification-thread] Failed to destroy channel information hash table");
}
}
+ lttng_session_trigger_list_destroy(session_info->trigger_list);
+
+ rcu_read_lock();
+ cds_lfht_del(session_info->sessions_ht,
+ &session_info->sessions_ht_node);
+ rcu_read_unlock();
free(session_info->name);
- free(session_info);
+ call_rcu(&session_info->rcu_node, free_session_info_rcu);
}
static
}
static
-struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid)
+struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid,
+ struct lttng_session_trigger_list *trigger_list,
+ struct cds_lfht *sessions_ht)
{
struct session_info *session_info;
}
session_info->uid = uid;
session_info->gid = gid;
+ session_info->trigger_list = trigger_list;
+ session_info->sessions_ht = sessions_ht;
end:
return session_info;
error:
return NULL;
}
-/* This function must be called with the RCU read lock held. */
static
-int evaluate_condition_for_client(struct lttng_trigger *trigger,
- struct lttng_condition *condition,
- struct notification_client *client,
- struct notification_thread_state *state)
+bool notification_client_list_get(struct notification_client_list *list)
+{
+ return urcu_ref_get_unless_zero(&list->ref);
+}
+
+static
+void free_notification_client_list_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct notification_client_list,
+ rcu_node));
+}
+
+static
+void notification_client_list_release(struct urcu_ref *list_ref)
+{
+ struct notification_client_list *list =
+ container_of(list_ref, typeof(*list), ref);
+ struct notification_client_list_element *client_list_element, *tmp;
+
+ if (list->notification_trigger_clients_ht) {
+ rcu_read_lock();
+ cds_lfht_del(list->notification_trigger_clients_ht,
+ &list->notification_trigger_clients_ht_node);
+ rcu_read_unlock();
+ list->notification_trigger_clients_ht = NULL;
+ }
+ cds_list_for_each_entry_safe(client_list_element, tmp,
+ &list->list, node) {
+ free(client_list_element);
+ }
+ pthread_mutex_destroy(&list->lock);
+ call_rcu(&list->rcu_node, free_notification_client_list_rcu);
+}
+
+static
+struct notification_client_list *notification_client_list_create(
+ const struct lttng_trigger *trigger)
+{
+ struct notification_client_list *client_list =
+ zmalloc(sizeof(*client_list));
+
+ if (!client_list) {
+ goto error;
+ }
+ pthread_mutex_init(&client_list->lock, NULL);
+ urcu_ref_init(&client_list->ref);
+ cds_lfht_node_init(&client_list->notification_trigger_clients_ht_node);
+ CDS_INIT_LIST_HEAD(&client_list->list);
+ client_list->trigger = trigger;
+error:
+ return client_list;
+}
+
+static
+void publish_notification_client_list(
+ struct notification_thread_state *state,
+ struct notification_client_list *list)
+{
+ const struct lttng_condition *condition =
+ lttng_trigger_get_const_condition(list->trigger);
+
+ assert(!list->notification_trigger_clients_ht);
+
+ list->notification_trigger_clients_ht =
+ state->notification_trigger_clients_ht;
+
+ rcu_read_lock();
+ cds_lfht_add(state->notification_trigger_clients_ht,
+ lttng_condition_hash(condition),
+ &list->notification_trigger_clients_ht_node);
+ rcu_read_unlock();
+}
+
+static
+void notification_client_list_put(struct notification_client_list *list)
+{
+ if (!list) {
+ return;
+ }
+ return urcu_ref_put(&list->ref, notification_client_list_release);
+}
+
+/* Provides a reference to the returned list. */
+static
+struct notification_client_list *get_client_list_from_condition(
+ struct notification_thread_state *state,
+ const struct lttng_condition *condition)
+{
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ struct notification_client_list *list = NULL;
+
+ rcu_read_lock();
+ cds_lfht_lookup(state->notification_trigger_clients_ht,
+ lttng_condition_hash(condition),
+ match_client_list_condition,
+ condition,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (node) {
+ list = container_of(node, struct notification_client_list,
+ notification_trigger_clients_ht_node);
+ list = notification_client_list_get(list) ? list : NULL;
+ }
+
+ rcu_read_unlock();
+ return list;
+}
+
+static
+int evaluate_channel_condition_for_client(
+ const struct lttng_condition *condition,
+ struct notification_thread_state *state,
+ struct lttng_evaluation **evaluation,
+ uid_t *session_uid, gid_t *session_gid)
{
int ret;
struct cds_lfht_iter iter;
struct channel_key *channel_key = NULL;
struct channel_state_sample *last_sample = NULL;
struct lttng_channel_trigger_list *channel_trigger_list = NULL;
- struct lttng_evaluation *evaluation = NULL;
- struct notification_client_list client_list = { 0 };
- struct notification_client_list_element client_list_element = { 0 };
- assert(trigger);
- assert(condition);
- assert(client);
- assert(state);
+ rcu_read_lock();
- /* Find the channel associated with the trigger. */
+ /* Find the channel associated with the condition. */
cds_lfht_for_each_entry(state->channel_triggers_ht, &iter,
- channel_trigger_list , channel_triggers_ht_node) {
+ channel_trigger_list, channel_triggers_ht_node) {
struct lttng_trigger_list_element *element;
cds_list_for_each_entry(element, &channel_trigger_list->list, node) {
- struct lttng_condition *current_condition =
- lttng_trigger_get_condition(
+ const struct lttng_condition *current_condition =
+ lttng_trigger_get_const_condition(
element->trigger);
assert(current_condition);
if (!channel_key){
/* No channel found; normal exit. */
- DBG("[notification-thread] No channel associated with newly subscribed-to condition");
+ DBG("[notification-thread] No known channel associated with newly subscribed-to condition");
ret = 0;
goto end;
}
goto end;
}
- ret = evaluate_condition(condition, &evaluation, state,
+ ret = evaluate_buffer_condition(condition, evaluation, state,
NULL, last_sample,
0, channel_info->session_info->consumed_data_size,
channel_info);
goto end;
}
- if (!evaluation) {
- /* Evaluation yielded nothing. Normal exit. */
- DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client");
+ *session_uid = channel_info->session_info->uid;
+ *session_gid = channel_info->session_info->gid;
+end:
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+const char *get_condition_session_name(const struct lttng_condition *condition)
+{
+ const char *session_name = NULL;
+ enum lttng_condition_status status;
+
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+ status = lttng_condition_buffer_usage_get_session_name(
+ condition, &session_name);
+ break;
+ case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+ status = lttng_condition_session_consumed_size_get_session_name(
+ condition, &session_name);
+ break;
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ status = lttng_condition_session_rotation_get_session_name(
+ condition, &session_name);
+ break;
+ default:
+ abort();
+ }
+ if (status != LTTNG_CONDITION_STATUS_OK) {
+ ERR("[notification-thread] Failed to retrieve session rotation condition's session name");
+ goto end;
+ }
+end:
+ return session_name;
+}
+
+static
+int evaluate_session_condition_for_client(
+ const struct lttng_condition *condition,
+ struct notification_thread_state *state,
+ struct lttng_evaluation **evaluation,
+ uid_t *session_uid, gid_t *session_gid)
+{
+ int ret;
+ struct cds_lfht_iter iter;
+ struct cds_lfht_node *node;
+ const char *session_name;
+ struct session_info *session_info = NULL;
+
+ rcu_read_lock();
+ session_name = get_condition_session_name(condition);
+
+ /* Find the session associated with the trigger. */
+ cds_lfht_lookup(state->sessions_ht,
+ hash_key_str(session_name, lttng_ht_seed),
+ match_session,
+ session_name,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (!node) {
+ DBG("[notification-thread] No known session matching name \"%s\"",
+ session_name);
ret = 0;
goto end;
}
+ session_info = caa_container_of(node, struct session_info,
+ sessions_ht_node);
+ session_info_get(session_info);
+
/*
- * Create a temporary client list with the client currently
- * subscribing.
+ * Evaluation is performed in-line here since only one type of
+ * session-bound condition is handled for the moment.
*/
- cds_lfht_node_init(&client_list.notification_trigger_ht_node);
- CDS_INIT_LIST_HEAD(&client_list.list);
- client_list.trigger = trigger;
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ if (!session_info->rotation.ongoing) {
+ ret = 0;
+ goto end_session_put;
+ }
- CDS_INIT_LIST_HEAD(&client_list_element.node);
- client_list_element.client = client;
- cds_list_add(&client_list_element.node, &client_list.list);
+ *evaluation = lttng_evaluation_session_rotation_ongoing_create(
+ session_info->rotation.id);
+ if (!*evaluation) {
+ /* Fatal error. */
+ ERR("[notification-thread] Failed to create session rotation ongoing evaluation for session \"%s\"",
+ session_info->name);
+ ret = -1;
+ goto end_session_put;
+ }
+ ret = 0;
+ break;
+ default:
+ ret = 0;
+ goto end_session_put;
+ }
- /* Send evaluation result to the newly-subscribed client. */
- DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client");
- ret = send_evaluation_to_clients(trigger, evaluation, &client_list,
- state, channel_info->session_info->uid,
- channel_info->session_info->gid);
+ *session_uid = session_info->uid;
+ *session_gid = session_info->gid;
+end_session_put:
+ session_info_put(session_info);
end:
+ rcu_read_unlock();
return ret;
}
static
-int notification_thread_client_subscribe(struct notification_client *client,
- struct lttng_condition *condition,
- struct notification_thread_state *state,
- enum lttng_notification_channel_status *_status)
-{
- int ret = 0;
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
- struct notification_client_list *client_list;
+int evaluate_condition_for_client(const struct lttng_trigger *trigger,
+ const struct lttng_condition *condition,
+ struct notification_client *client,
+ struct notification_thread_state *state)
+{
+ int ret;
+ struct lttng_evaluation *evaluation = NULL;
+ struct notification_client_list client_list = {
+ .lock = PTHREAD_MUTEX_INITIALIZER,
+ };
+ struct notification_client_list_element client_list_element = { 0 };
+ uid_t object_uid = 0;
+ gid_t object_gid = 0;
+
+ assert(trigger);
+ assert(condition);
+ assert(client);
+ assert(state);
+
+ switch (get_condition_binding_object(condition)) {
+ case LTTNG_OBJECT_TYPE_SESSION:
+ ret = evaluate_session_condition_for_client(condition, state,
+ &evaluation, &object_uid, &object_gid);
+ break;
+ case LTTNG_OBJECT_TYPE_CHANNEL:
+ ret = evaluate_channel_condition_for_client(condition, state,
+ &evaluation, &object_uid, &object_gid);
+ break;
+ case LTTNG_OBJECT_TYPE_NONE:
+ ret = 0;
+ goto end;
+ case LTTNG_OBJECT_TYPE_UNKNOWN:
+ default:
+ ret = -1;
+ goto end;
+ }
+ if (ret) {
+ /* Fatal error. */
+ goto end;
+ }
+ if (!evaluation) {
+ /* Evaluation yielded nothing. Normal exit. */
+ DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client");
+ ret = 0;
+ goto end;
+ }
+
+ /*
+ * Create a temporary client list with the client currently
+ * subscribing.
+ */
+ cds_lfht_node_init(&client_list.notification_trigger_clients_ht_node);
+ CDS_INIT_LIST_HEAD(&client_list.list);
+ client_list.trigger = trigger;
+
+ CDS_INIT_LIST_HEAD(&client_list_element.node);
+ client_list_element.client = client;
+ cds_list_add(&client_list_element.node, &client_list.list);
+
+ /* Send evaluation result to the newly-subscribed client. */
+ DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client");
+ ret = send_evaluation_to_clients(trigger, evaluation, &client_list,
+ state, object_uid, object_gid);
+
+end:
+ return ret;
+}
+
+static
+int notification_thread_client_subscribe(struct notification_client *client,
+ struct lttng_condition *condition,
+ struct notification_thread_state *state,
+ enum lttng_notification_channel_status *_status)
+{
+ int ret = 0;
+ struct notification_client_list *client_list = NULL;
struct lttng_condition_list_element *condition_list_element = NULL;
struct notification_client_list_element *client_list_element = NULL;
enum lttng_notification_channel_status status =
goto error;
}
- rcu_read_lock();
-
/*
* Add the newly-subscribed condition to the client's subscription list.
*/
condition_list_element->condition = condition;
cds_list_add(&condition_list_element->node, &client->condition_list);
- cds_lfht_lookup(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- match_client_list_condition,
- condition,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
+ client_list = get_client_list_from_condition(state, condition);
+ if (!client_list) {
/*
* No notification-emiting trigger registered with this
* condition. We don't evaluate the condition right away
* since this trigger is not registered yet.
*/
free(client_list_element);
- goto end_unlock;
+ goto end;
}
- client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
/*
* The condition to which the client just subscribed is evaluated
* at this point so that conditions that are already TRUE result
* in a notification being sent out.
+ *
+ * The client_list's trigger is used without locking the list itself.
+ * This is correct since the list doesn't own the trigger and the
+ * object is immutable.
*/
if (evaluate_condition_for_client(client_list->trigger, condition,
client, state)) {
WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting.");
ret = -1;
- goto end_unlock;
+ free(client_list_element);
+ goto end;
}
/*
*/
client_list_element->client = client;
CDS_INIT_LIST_HEAD(&client_list_element->node);
+
+ pthread_mutex_lock(&client_list->lock);
cds_list_add(&client_list_element->node, &client_list->list);
-end_unlock:
- rcu_read_unlock();
+ pthread_mutex_unlock(&client_list->lock);
end:
if (_status) {
*_status = status;
}
+ if (client_list) {
+ notification_client_list_put(client_list);
+ }
return ret;
error:
free(condition_list_element);
struct notification_thread_state *state,
enum lttng_notification_channel_status *_status)
{
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
struct notification_client_list *client_list;
struct lttng_condition_list_element *condition_list_element,
*condition_tmp;
* Remove the client from the list of clients interested the trigger
* matching the condition.
*/
- rcu_read_lock();
- cds_lfht_lookup(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- match_client_list_condition,
- condition,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- goto end_unlock;
+ client_list = get_client_list_from_condition(state, condition);
+ if (!client_list) {
+ goto end;
}
- client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
+ pthread_mutex_lock(&client_list->lock);
cds_list_for_each_entry_safe(client_list_element, client_tmp,
&client_list->list, node) {
- if (client_list_element->client->socket != client->socket) {
+ if (client_list_element->client->id != client->id) {
continue;
}
cds_list_del(&client_list_element->node);
free(client_list_element);
break;
}
-end_unlock:
- rcu_read_unlock();
+ pthread_mutex_unlock(&client_list->lock);
+ notification_client_list_put(client_list);
+ client_list = NULL;
end:
lttng_condition_destroy(condition);
if (_status) {
return 0;
}
+static
+void free_notification_client_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct notification_client, rcu_node));
+}
+
static
void notification_client_destroy(struct notification_client *client,
struct notification_thread_state *state)
{
- struct lttng_condition_list_element *condition_list_element, *tmp;
-
if (!client) {
return;
}
- /* Release all conditions to which the client was subscribed. */
- cds_list_for_each_entry_safe(condition_list_element, tmp,
- &client->condition_list, node) {
- (void) notification_thread_client_unsubscribe(client,
- condition_list_element->condition, state, NULL);
- }
-
+ /*
+ * The client object is not reachable by other threads, no need to lock
+ * the client here.
+ */
if (client->socket >= 0) {
(void) lttcomm_close_unix_sock(client->socket);
+ client->socket = -1;
}
+ client->communication.active = false;
lttng_dynamic_buffer_reset(&client->communication.inbound.buffer);
lttng_dynamic_buffer_reset(&client->communication.outbound.buffer);
- free(client);
+ pthread_mutex_destroy(&client->lock);
+ call_rcu(&client->rcu_node, free_notification_client_rcu);
}
/*
struct notification_client *client = NULL;
cds_lfht_lookup(state->client_socket_ht,
- hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed),
- match_client,
+ hash_client_socket(socket),
+ match_client_socket,
(void *) (unsigned long) socket,
&iter);
node = cds_lfht_iter_get_node(&iter);
static
bool buffer_usage_condition_applies_to_channel(
- struct lttng_condition *condition,
- struct channel_info *channel_info)
+ const struct lttng_condition *condition,
+ const struct channel_info *channel_info)
{
enum lttng_condition_status status;
enum lttng_domain_type condition_domain;
static
bool session_consumed_size_condition_applies_to_channel(
- struct lttng_condition *condition,
- struct channel_info *channel_info)
+ const struct lttng_condition *condition,
+ const struct channel_info *channel_info)
{
enum lttng_condition_status status;
const char *condition_session_name = NULL;
}
static
-bool trigger_applies_to_channel(struct lttng_trigger *trigger,
- struct channel_info *channel_info)
+bool trigger_applies_to_channel(const struct lttng_trigger *trigger,
+ const struct channel_info *channel_info)
{
- struct lttng_condition *condition;
+ const struct lttng_condition *condition;
bool trigger_applies;
- condition = lttng_trigger_get_condition(trigger);
+ condition = lttng_trigger_get_const_condition(trigger);
if (!condition) {
goto fail;
}
return applies;
}
+/* Must be called with RCU read lock held. */
static
-int match_session(struct cds_lfht_node *node, const void *key)
+struct lttng_session_trigger_list *get_session_trigger_list(
+ struct notification_thread_state *state,
+ const char *session_name)
{
- const char *name = key;
- struct session_info *session_info = caa_container_of(
- node, struct session_info, sessions_ht_node);
+ struct lttng_session_trigger_list *list = NULL;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
- return !strcmp(session_info->name, name);
+ cds_lfht_lookup(state->session_triggers_ht,
+ hash_key_str(session_name, lttng_ht_seed),
+ match_session_trigger_list,
+ session_name,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (!node) {
+ /*
+ * Not an error, the list of triggers applying to that session
+ * will be initialized when the session is created.
+ */
+ DBG("[notification-thread] No trigger list found for session \"%s\" as it is not yet known to the notification system",
+ session_name);
+ goto end;
+ }
+
+ list = caa_container_of(node,
+ struct lttng_session_trigger_list,
+ session_triggers_ht_node);
+end:
+ return list;
+}
+
+/*
+ * Allocate an empty lttng_session_trigger_list for the session named
+ * 'session_name'.
+ *
+ * No ownership of 'session_name' is assumed by the session trigger list.
+ * It is the caller's responsability to ensure the session name is alive
+ * for as long as this list is.
+ */
+static
+struct lttng_session_trigger_list *lttng_session_trigger_list_create(
+ const char *session_name,
+ struct cds_lfht *session_triggers_ht)
+{
+ struct lttng_session_trigger_list *list;
+
+ list = zmalloc(sizeof(*list));
+ if (!list) {
+ goto end;
+ }
+ list->session_name = session_name;
+ CDS_INIT_LIST_HEAD(&list->list);
+ cds_lfht_node_init(&list->session_triggers_ht_node);
+ list->session_triggers_ht = session_triggers_ht;
+
+ rcu_read_lock();
+ /* Publish the list through the session_triggers_ht. */
+ cds_lfht_add(session_triggers_ht,
+ hash_key_str(session_name, lttng_ht_seed),
+ &list->session_triggers_ht_node);
+ rcu_read_unlock();
+end:
+ return list;
+}
+
+static
+void free_session_trigger_list_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct lttng_session_trigger_list,
+ rcu_node));
+}
+
+static
+void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list *list)
+{
+ struct lttng_trigger_list_element *trigger_list_element, *tmp;
+
+ /* Empty the list element by element, and then free the list itself. */
+ cds_list_for_each_entry_safe(trigger_list_element, tmp,
+ &list->list, node) {
+ cds_list_del(&trigger_list_element->node);
+ free(trigger_list_element);
+ }
+ rcu_read_lock();
+ /* Unpublish the list from the session_triggers_ht. */
+ cds_lfht_del(list->session_triggers_ht,
+ &list->session_triggers_ht_node);
+ rcu_read_unlock();
+ call_rcu(&list->rcu_node, free_session_trigger_list_rcu);
+}
+
+static
+int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
+ const struct lttng_trigger *trigger)
+{
+ int ret = 0;
+ struct lttng_trigger_list_element *new_element =
+ zmalloc(sizeof(*new_element));
+
+ if (!new_element) {
+ ret = -1;
+ goto end;
+ }
+ CDS_INIT_LIST_HEAD(&new_element->node);
+ new_element->trigger = trigger;
+ cds_list_add(&new_element->node, &list->list);
+end:
+ return ret;
+}
+
+static
+bool trigger_applies_to_session(const struct lttng_trigger *trigger,
+ const char *session_name)
+{
+ bool applies = false;
+ const struct lttng_condition *condition;
+
+ condition = lttng_trigger_get_const_condition(trigger);
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ {
+ enum lttng_condition_status condition_status;
+ const char *condition_session_name;
+
+ condition_status = lttng_condition_session_rotation_get_session_name(
+ condition, &condition_session_name);
+ if (condition_status != LTTNG_CONDITION_STATUS_OK) {
+ ERR("[notification-thread] Failed to retrieve session rotation condition's session name");
+ goto end;
+ }
+
+ assert(condition_session_name);
+ applies = !strcmp(condition_session_name, session_name);
+ break;
+ }
+ default:
+ goto end;
+ }
+end:
+ return applies;
+}
+
+/*
+ * Allocate and initialize an lttng_session_trigger_list which contains
+ * all triggers that apply to the session named 'session_name'.
+ *
+ * No ownership of 'session_name' is assumed by the session trigger list.
+ * It is the caller's responsability to ensure the session name is alive
+ * for as long as this list is.
+ */
+static
+struct lttng_session_trigger_list *lttng_session_trigger_list_build(
+ const struct notification_thread_state *state,
+ const char *session_name)
+{
+ int trigger_count = 0;
+ struct lttng_session_trigger_list *session_trigger_list = NULL;
+ struct lttng_trigger_ht_element *trigger_ht_element = NULL;
+ struct cds_lfht_iter iter;
+
+ session_trigger_list = lttng_session_trigger_list_create(session_name,
+ state->session_triggers_ht);
+
+ /* Add all triggers applying to the session named 'session_name'. */
+ cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
+ node) {
+ int ret;
+
+ if (!trigger_applies_to_session(trigger_ht_element->trigger,
+ session_name)) {
+ continue;
+ }
+
+ ret = lttng_session_trigger_list_add(session_trigger_list,
+ trigger_ht_element->trigger);
+ if (ret) {
+ goto error;
+ }
+
+ trigger_count++;
+ }
+
+ DBG("[notification-thread] Found %i triggers that apply to newly created session",
+ trigger_count);
+ return session_trigger_list;
+error:
+ lttng_session_trigger_list_destroy(session_trigger_list);
+ return NULL;
}
static
struct session_info *session = NULL;
struct cds_lfht_node *node;
struct cds_lfht_iter iter;
+ struct lttng_session_trigger_list *trigger_list;
rcu_read_lock();
cds_lfht_lookup(state->sessions_ht,
sessions_ht_node);
assert(session->uid == uid);
assert(session->gid == gid);
+ session_info_get(session);
goto end;
}
- session = session_info_create(name, uid, gid);
+ trigger_list = lttng_session_trigger_list_build(state, name);
+ if (!trigger_list) {
+ goto error;
+ }
+
+ session = session_info_create(name, uid, gid, trigger_list,
+ state->sessions_ht);
if (!session) {
ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
name, uid, gid);
- goto end;
+ lttng_session_trigger_list_destroy(trigger_list);
+ goto error;
}
+ trigger_list = NULL;
+
+ cds_lfht_add(state->sessions_ht, hash_key_str(name, lttng_ht_seed),
+ &session->sessions_ht_node);
end:
rcu_read_unlock();
return session;
+error:
+ rcu_read_unlock();
+ session_info_put(session);
+ return NULL;
}
static
session_info = find_or_create_session_info(state, session_name,
session_uid, session_gid);
if (!session_info) {
- /* Allocation error or an internal error occured. */
+ /* Allocation error or an internal error occurred. */
goto error;
}
goto error;
}
+ rcu_read_lock();
/* Build a list of all triggers applying to the new channel. */
cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
node) {
new_element = zmalloc(sizeof(*new_element));
if (!new_element) {
+ rcu_read_unlock();
goto error;
}
CDS_INIT_LIST_HEAD(&new_element->node);
cds_list_add(&new_element->node, &trigger_list);
trigger_count++;
}
+ rcu_read_unlock();
DBG("[notification-thread] Found %i triggers that apply to newly added channel",
trigger_count);
hash_channel_key(&new_channel_info->key),
&channel_trigger_list->channel_triggers_ht_node);
rcu_read_unlock();
+ session_info_put(session_info);
*cmd_result = LTTNG_OK;
return 0;
error:
return 1;
}
+static
+void free_channel_trigger_list_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct lttng_channel_trigger_list,
+ rcu_node));
+}
+
+static
+void free_channel_state_sample_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct channel_state_sample,
+ rcu_node));
+}
+
static
int handle_notification_thread_command_remove_channel(
struct notification_thread_state *state,
free(trigger_list_element);
}
cds_lfht_del(state->channel_triggers_ht, node);
- free(trigger_list);
+ call_rcu(&trigger_list->rcu_node, free_channel_trigger_list_rcu);
/* Free sampled channel state. */
cds_lfht_lookup(state->channel_state_ht,
struct channel_state_sample,
channel_state_ht_node);
- cds_lfht_del(state->channel_state_ht, node);
- free(sample);
- }
+ cds_lfht_del(state->channel_state_ht, node);
+ call_rcu(&sample->rcu_node, free_channel_state_sample_rcu);
+ }
+
+ /* Remove the channel from the channels_ht and free it. */
+ cds_lfht_lookup(state->channels_ht,
+ hash_channel_key(&key),
+ match_channel_info,
+ &key,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ assert(node);
+ channel_info = caa_container_of(node, struct channel_info,
+ channels_ht_node);
+ cds_lfht_del(state->channels_ht, node);
+ channel_info_destroy(channel_info);
+end:
+ rcu_read_unlock();
+ *cmd_result = LTTNG_OK;
+ return 0;
+}
+
+static
+int handle_notification_thread_command_session_rotation(
+ struct notification_thread_state *state,
+ enum notification_thread_command_type cmd_type,
+ const char *session_name, uid_t session_uid, gid_t session_gid,
+ uint64_t trace_archive_chunk_id,
+ struct lttng_trace_archive_location *location,
+ enum lttng_error_code *_cmd_result)
+{
+ int ret = 0;
+ enum lttng_error_code cmd_result = LTTNG_OK;
+ struct lttng_session_trigger_list *trigger_list;
+ struct lttng_trigger_list_element *trigger_list_element;
+ struct session_info *session_info;
+
+ rcu_read_lock();
+
+ session_info = find_or_create_session_info(state, session_name,
+ session_uid, session_gid);
+ if (!session_info) {
+ /* Allocation error or an internal error occurred. */
+ ret = -1;
+ cmd_result = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ session_info->rotation.ongoing =
+ cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING;
+ session_info->rotation.id = trace_archive_chunk_id;
+ trigger_list = get_session_trigger_list(state, session_name);
+ if (!trigger_list) {
+ DBG("[notification-thread] No triggers applying to session \"%s\" found",
+ session_name);
+ goto end;
+ }
+
+ cds_list_for_each_entry(trigger_list_element, &trigger_list->list,
+ node) {
+ const struct lttng_condition *condition;
+ const struct lttng_action *action;
+ const struct lttng_trigger *trigger;
+ struct notification_client_list *client_list;
+ struct lttng_evaluation *evaluation = NULL;
+ enum lttng_condition_type condition_type;
+ bool client_list_is_empty;
+
+ trigger = trigger_list_element->trigger;
+ condition = lttng_trigger_get_const_condition(trigger);
+ assert(condition);
+ condition_type = lttng_condition_get_type(condition);
+
+ if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING &&
+ cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) {
+ continue;
+ } else if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED &&
+ cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED) {
+ continue;
+ }
+
+ action = lttng_trigger_get_const_action(trigger);
+
+ /* Notify actions are the only type currently supported. */
+ assert(lttng_action_get_type_const(action) ==
+ LTTNG_ACTION_TYPE_NOTIFY);
+
+ client_list = get_client_list_from_condition(state, condition);
+ assert(client_list);
+
+ pthread_mutex_lock(&client_list->lock);
+ client_list_is_empty = cds_list_empty(&client_list->list);
+ pthread_mutex_unlock(&client_list->lock);
+ if (client_list_is_empty) {
+ /*
+ * No clients interested in the evaluation's result,
+ * skip it.
+ */
+ continue;
+ }
+
+ if (cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) {
+ evaluation = lttng_evaluation_session_rotation_ongoing_create(
+ trace_archive_chunk_id);
+ } else {
+ evaluation = lttng_evaluation_session_rotation_completed_create(
+ trace_archive_chunk_id, location);
+ }
- /* Remove the channel from the channels_ht and free it. */
- cds_lfht_lookup(state->channels_ht,
- hash_channel_key(&key),
- match_channel_info,
- &key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
- channel_info = caa_container_of(node, struct channel_info,
- channels_ht_node);
- cds_lfht_del(state->channels_ht, node);
- channel_info_destroy(channel_info);
+ if (!evaluation) {
+ /* Internal error */
+ ret = -1;
+ cmd_result = LTTNG_ERR_UNK;
+ goto put_list;
+ }
+
+ /* Dispatch evaluation result to all clients. */
+ ret = send_evaluation_to_clients(trigger_list_element->trigger,
+ evaluation, client_list, state,
+ session_info->uid,
+ session_info->gid);
+ lttng_evaluation_destroy(evaluation);
+put_list:
+ notification_client_list_put(client_list);
+ if (caa_unlikely(ret)) {
+ break;
+ }
+ }
end:
+ session_info_put(session_info);
+ *_cmd_result = cmd_result;
rcu_read_unlock();
- *cmd_result = LTTNG_OK;
- return 0;
+ return ret;
}
static
* buffers. Therefore, we reject triggers that require that
* mechanism to be available to be evaluated.
*/
- ret = kernel_supports_ring_buffer_snapshot_sample_positions(
- kernel_tracer_fd);
+ ret = kernel_supports_ring_buffer_snapshot_sample_positions();
break;
}
default:
return ret;
}
+/* Must be called with RCU read lock held. */
+static
+int bind_trigger_to_matching_session(const struct lttng_trigger *trigger,
+ struct notification_thread_state *state)
+{
+ int ret = 0;
+ const struct lttng_condition *condition;
+ const char *session_name;
+ struct lttng_session_trigger_list *trigger_list;
+
+ condition = lttng_trigger_get_const_condition(trigger);
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ {
+ enum lttng_condition_status status;
+
+ status = lttng_condition_session_rotation_get_session_name(
+ condition, &session_name);
+ if (status != LTTNG_CONDITION_STATUS_OK) {
+ ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name");
+ ret = -1;
+ goto end;
+ }
+ break;
+ }
+ default:
+ ret = -1;
+ goto end;
+ }
+
+ trigger_list = get_session_trigger_list(state, session_name);
+ if (!trigger_list) {
+ DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system",
+ session_name);
+ goto end;
+
+ }
+
+ DBG("[notification-thread] Newly registered trigger bound to session \"%s\"",
+ session_name);
+ ret = lttng_session_trigger_list_add(trigger_list, trigger);
+end:
+ return ret;
+}
+
+/* Must be called with RCU read lock held. */
+static
+int bind_trigger_to_matching_channels(const struct lttng_trigger *trigger,
+ struct notification_thread_state *state)
+{
+ int ret = 0;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ struct channel_info *channel;
+
+ cds_lfht_for_each_entry(state->channels_ht, &iter, channel,
+ channels_ht_node) {
+ struct lttng_trigger_list_element *trigger_list_element;
+ struct lttng_channel_trigger_list *trigger_list;
+ struct cds_lfht_iter lookup_iter;
+
+ if (!trigger_applies_to_channel(trigger, channel)) {
+ continue;
+ }
+
+ cds_lfht_lookup(state->channel_triggers_ht,
+ hash_channel_key(&channel->key),
+ match_channel_trigger_list,
+ &channel->key,
+ &lookup_iter);
+ node = cds_lfht_iter_get_node(&lookup_iter);
+ assert(node);
+ trigger_list = caa_container_of(node,
+ struct lttng_channel_trigger_list,
+ channel_triggers_ht_node);
+
+ trigger_list_element = zmalloc(sizeof(*trigger_list_element));
+ if (!trigger_list_element) {
+ ret = -1;
+ goto end;
+ }
+ CDS_INIT_LIST_HEAD(&trigger_list_element->node);
+ trigger_list_element->trigger = trigger;
+ cds_list_add(&trigger_list_element->node, &trigger_list->list);
+ DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"",
+ channel->name);
+ }
+end:
+ return ret;
+}
+
/*
* FIXME A client's credentials are not checked when registering a trigger, nor
* are they stored alongside with the trigger.
*
* The effects of this are benign since:
* - The client will succeed in registering the trigger, as it is valid,
- * - The trigger will, internally, be bound to the channel,
+ * - The trigger will, internally, be bound to the channel/session,
* - The notifications will not be sent since the client's credentials
* are checked against the channel at that moment.
*
struct notification_client_list_element *client_list_element, *tmp;
struct cds_lfht_node *node;
struct cds_lfht_iter iter;
- struct channel_info *channel;
bool free_trigger = true;
rcu_read_lock();
* It is not skipped as this is the only action type currently
* supported.
*/
- client_list = zmalloc(sizeof(*client_list));
+ client_list = notification_client_list_create(trigger);
if (!client_list) {
ret = -1;
goto error_free_ht_element;
}
- cds_lfht_node_init(&client_list->notification_trigger_ht_node);
- CDS_INIT_LIST_HEAD(&client_list->list);
- client_list->trigger = trigger;
/* Build a list of clients to which this new trigger applies. */
cds_lfht_for_each_entry(state->client_socket_ht, &iter, client,
client_list_element = zmalloc(sizeof(*client_list_element));
if (!client_list_element) {
ret = -1;
- goto error_free_client_list;
+ goto error_put_client_list;
}
CDS_INIT_LIST_HEAD(&client_list_element->node);
client_list_element->client = client;
cds_list_add(&client_list_element->node, &client_list->list);
}
- cds_lfht_add(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- &client_list->notification_trigger_ht_node);
-
- /*
- * Add the trigger to list of triggers bound to the channels currently
- * known.
- */
- cds_lfht_for_each_entry(state->channels_ht, &iter, channel,
- channels_ht_node) {
- struct lttng_trigger_list_element *trigger_list_element;
- struct lttng_channel_trigger_list *trigger_list;
-
- if (!trigger_applies_to_channel(trigger, channel)) {
- continue;
+ switch (get_condition_binding_object(condition)) {
+ case LTTNG_OBJECT_TYPE_SESSION:
+ /* Add the trigger to the list if it matches a known session. */
+ ret = bind_trigger_to_matching_session(trigger, state);
+ if (ret) {
+ goto error_put_client_list;
}
-
- cds_lfht_lookup(state->channel_triggers_ht,
- hash_channel_key(&channel->key),
- match_channel_trigger_list,
- &channel->key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
- trigger_list = caa_container_of(node,
- struct lttng_channel_trigger_list,
- channel_triggers_ht_node);
-
- trigger_list_element = zmalloc(sizeof(*trigger_list_element));
- if (!trigger_list_element) {
- ret = -1;
- goto error_free_client_list;
+ break;
+ case LTTNG_OBJECT_TYPE_CHANNEL:
+ /*
+ * Add the trigger to list of triggers bound to the channels
+ * currently known.
+ */
+ ret = bind_trigger_to_matching_channels(trigger, state);
+ if (ret) {
+ goto error_put_client_list;
}
- CDS_INIT_LIST_HEAD(&trigger_list_element->node);
- trigger_list_element->trigger = trigger;
- cds_list_add(&trigger_list_element->node, &trigger_list->list);
+ break;
+ case LTTNG_OBJECT_TYPE_NONE:
+ break;
+ default:
+ ERR("[notification-thread] Unknown object type on which to bind a newly registered trigger was encountered");
+ ret = -1;
+ goto error_put_client_list;
}
/*
* current state. Otherwise, the next evaluation cycle may only see
* that the evaluations remain the same (true for samples n-1 and n) and
* the client will never know that the condition has been met.
+ *
+ * No need to lock the list here as it has not been published yet.
*/
cds_list_for_each_entry_safe(client_list_element, tmp,
&client_list->list, node) {
ret = evaluate_condition_for_client(trigger, condition,
client_list_element->client, state);
if (ret) {
- goto error_free_client_list;
+ goto error_put_client_list;
}
}
* Client list ownership transferred to the
* notification_trigger_clients_ht.
*/
+ publish_notification_client_list(state, client_list);
client_list = NULL;
*cmd_result = LTTNG_OK;
-error_free_client_list:
- if (client_list) {
- cds_list_for_each_entry_safe(client_list_element, tmp,
- &client_list->list, node) {
- free(client_list_element);
- }
- free(client_list);
- }
+
+error_put_client_list:
+ notification_client_list_put(client_list);
+
error_free_ht_element:
free(trigger_ht_element);
error:
if (free_trigger) {
- struct lttng_action *action = lttng_trigger_get_action(trigger);
-
- lttng_condition_destroy(condition);
- lttng_action_destroy(action);
lttng_trigger_destroy(trigger);
}
rcu_read_unlock();
return ret;
}
+static
+void free_lttng_trigger_ht_element_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct lttng_trigger_ht_element,
+ rcu_node));
+}
+
static
int handle_notification_thread_command_unregister_trigger(
struct notification_thread_state *state,
enum lttng_error_code *_cmd_reply)
{
struct cds_lfht_iter iter;
- struct cds_lfht_node *node, *triggers_ht_node;
+ struct cds_lfht_node *triggers_ht_node;
struct lttng_channel_trigger_list *trigger_list;
struct notification_client_list *client_list;
- struct notification_client_list_element *client_list_element, *tmp;
struct lttng_trigger_ht_element *trigger_ht_element = NULL;
struct lttng_condition *condition = lttng_trigger_get_condition(
trigger);
- struct lttng_action *action;
enum lttng_error_code cmd_reply;
rcu_read_lock();
cds_list_for_each_entry_safe(trigger_element, tmp,
&trigger_list->list, node) {
- struct lttng_condition *current_condition =
- lttng_trigger_get_condition(
+ const struct lttng_condition *current_condition =
+ lttng_trigger_get_const_condition(
trigger_element->trigger);
assert(current_condition);
* Remove and release the client list from
* notification_trigger_clients_ht.
*/
- cds_lfht_lookup(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- match_client_list,
- trigger,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
- client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
- cds_list_for_each_entry_safe(client_list_element, tmp,
- &client_list->list, node) {
- free(client_list_element);
- }
- cds_lfht_del(state->notification_trigger_clients_ht, node);
- free(client_list);
+ client_list = get_client_list_from_condition(state, condition);
+ assert(client_list);
+
+ /* Put new reference and the hashtable's reference. */
+ notification_client_list_put(client_list);
+ notification_client_list_put(client_list);
+ client_list = NULL;
/* Remove trigger from triggers_ht. */
trigger_ht_element = caa_container_of(triggers_ht_node,
struct lttng_trigger_ht_element, node);
cds_lfht_del(state->triggers_ht, triggers_ht_node);
- condition = lttng_trigger_get_condition(trigger_ht_element->trigger);
- lttng_condition_destroy(condition);
- action = lttng_trigger_get_action(trigger_ht_element->trigger);
- lttng_action_destroy(action);
+ /* Release the ownership of the trigger. */
lttng_trigger_destroy(trigger_ht_element->trigger);
- free(trigger_ht_element);
+ call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu);
end:
rcu_read_unlock();
if (_cmd_reply) {
struct notification_thread_command *cmd;
/* Read the event pipe to put it back into a quiescent state. */
- ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter,
+ ret = lttng_read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter,
sizeof(counter));
- if (ret == -1) {
+ if (ret != sizeof(counter)) {
goto error;
}
pthread_mutex_lock(&handle->cmd_queue.lock);
cmd = cds_list_first_entry(&handle->cmd_queue.list,
struct notification_thread_command, cmd_list_node);
+ cds_list_del(&cmd->cmd_list_node);
+ pthread_mutex_unlock(&handle->cmd_queue.lock);
switch (cmd->type) {
case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER:
DBG("[notification-thread] Received register trigger command");
cmd->parameters.remove_channel.domain,
&cmd->reply_code);
break;
+ case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING:
+ case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED:
+ DBG("[notification-thread] Received session rotation %s command",
+ cmd->type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING ?
+ "ongoing" : "completed");
+ ret = handle_notification_thread_command_session_rotation(
+ state,
+ cmd->type,
+ cmd->parameters.session_rotation.session_name,
+ cmd->parameters.session_rotation.uid,
+ cmd->parameters.session_rotation.gid,
+ cmd->parameters.session_rotation.trace_archive_chunk_id,
+ cmd->parameters.session_rotation.location,
+ &cmd->reply_code);
+ break;
case NOTIFICATION_COMMAND_TYPE_QUIT:
DBG("[notification-thread] Received quit command");
cmd->reply_code = LTTNG_OK;
goto error_unlock;
}
end:
- cds_list_del(&cmd->cmd_list_node);
- lttng_waiter_wake_up(&cmd->reply_waiter);
- pthread_mutex_unlock(&handle->cmd_queue.lock);
+ if (cmd->is_async) {
+ free(cmd);
+ cmd = NULL;
+ } else {
+ lttng_waiter_wake_up(&cmd->reply_waiter);
+ }
return ret;
error_unlock:
/* Wake-up and return a fatal error to the calling thread. */
lttng_waiter_wake_up(&cmd->reply_waiter);
- pthread_mutex_unlock(&handle->cmd_queue.lock);
cmd->reply_code = LTTNG_ERR_FATAL;
error:
/* Indicate a fatal error to the caller. */
return -1;
}
-static
-unsigned long hash_client_socket(int socket)
-{
- return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed);
-}
-
static
int socket_set_non_blocking(int socket)
{
return ret;
}
+/* Client lock must be acquired by caller. */
static
int client_reset_inbound_state(struct notification_client *client)
{
int ret;
+ ASSERT_LOCKED(client->lock);
+
ret = lttng_dynamic_buffer_set_size(
&client->communication.inbound.buffer, 0);
assert(!ret);
ret = -1;
goto error;
}
+ pthread_mutex_init(&client->lock, NULL);
+ client->id = state->next_notification_client_id++;
CDS_INIT_LIST_HEAD(&client->condition_list);
lttng_dynamic_buffer_init(&client->communication.inbound.buffer);
lttng_dynamic_buffer_init(&client->communication.outbound.buffer);
client->communication.inbound.expect_creds = true;
+
+ pthread_mutex_lock(&client->lock);
ret = client_reset_inbound_state(client);
+ pthread_mutex_unlock(&client->lock);
if (ret) {
ERR("[notification-thread] Failed to reset client communication's inbound state");
- ret = 0;
+ ret = 0;
goto error;
}
cds_lfht_add(state->client_socket_ht,
hash_client_socket(client->socket),
&client->client_socket_ht_node);
+ cds_lfht_add(state->client_id_ht,
+ hash_client_id(client->id),
+ &client->client_id_ht_node);
rcu_read_unlock();
return ret;
return ret;
}
-int handle_notification_thread_client_disconnect(
- int client_socket,
+/* RCU read-lock must be held by the caller. */
+/* Client lock must be held by the caller */
+static
+int notification_thread_client_disconnect(
+ struct notification_client *client,
struct notification_thread_state *state)
+{
+ int ret;
+ struct lttng_condition_list_element *condition_list_element, *tmp;
+
+ /* Acquire the client lock to disable its communication atomically. */
+ client->communication.active = false;
+ ret = lttng_poll_del(&state->events, client->socket);
+ if (ret) {
+ ERR("[notification-thread] Failed to remove client socket %d from poll set",
+ client->socket);
+ }
+
+ cds_lfht_del(state->client_socket_ht, &client->client_socket_ht_node);
+ cds_lfht_del(state->client_id_ht, &client->client_id_ht_node);
+
+ /* Release all conditions to which the client was subscribed. */
+ cds_list_for_each_entry_safe(condition_list_element, tmp,
+ &client->condition_list, node) {
+ (void) notification_thread_client_unsubscribe(client,
+ condition_list_element->condition, state, NULL);
+ }
+
+ /*
+ * Client no longer accessible to other threads (through the
+ * client lists).
+ */
+ notification_client_destroy(client, state);
+ return ret;
+}
+
+int handle_notification_thread_client_disconnect(
+ int client_socket, struct notification_thread_state *state)
{
int ret = 0;
struct notification_client *client;
goto end;
}
- ret = lttng_poll_del(&state->events, client_socket);
- if (ret) {
- ERR("[notification-thread] Failed to remove client socket from poll set");
- }
- cds_lfht_del(state->client_socket_ht,
- &client->client_socket_ht_node);
- notification_client_destroy(client, state);
+ pthread_mutex_lock(&client->lock);
+ ret = notification_thread_client_disconnect(client, state);
+ pthread_mutex_unlock(&client->lock);
end:
rcu_read_unlock();
return ret;
rcu_read_lock();
DBG("[notification-thread] Closing all client connections");
cds_lfht_for_each_entry(state->client_socket_ht, &iter, client,
- client_socket_ht_node) {
+ client_socket_ht_node) {
int ret;
- ret = handle_notification_thread_client_disconnect(
- client->socket, state);
+ pthread_mutex_lock(&client->lock);
+ ret = notification_thread_client_disconnect(
+ client, state);
+ pthread_mutex_unlock(&client->lock);
if (ret) {
error_encoutered = true;
}
struct cds_lfht_iter iter;
struct lttng_trigger_ht_element *trigger_ht_element;
+ rcu_read_lock();
cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
node) {
int ret = handle_notification_thread_command_unregister_trigger(
error_occurred = true;
}
}
- return error_occurred ? -1 : 0;
+ rcu_read_unlock();
+ return error_occurred ? -1 : 0;
+}
+
+static
+int client_handle_transmission_status(
+ struct notification_client *client,
+ enum client_transmission_status transmission_status,
+ struct notification_thread_state *state)
+{
+ int ret = 0;
+
+ switch (transmission_status) {
+ case CLIENT_TRANSMISSION_STATUS_COMPLETE:
+ ret = lttng_poll_mod(&state->events, client->socket,
+ CLIENT_POLL_MASK_IN);
+ if (ret) {
+ goto end;
+ }
+
+ client->communication.outbound.queued_command_reply = false;
+ client->communication.outbound.dropped_notification = false;
+ break;
+ case CLIENT_TRANSMISSION_STATUS_QUEUED:
+ /*
+ * We want to be notified whenever there is buffer space
+ * available to send the rest of the payload.
+ */
+ ret = lttng_poll_mod(&state->events, client->socket,
+ CLIENT_POLL_MASK_IN_OUT);
+ if (ret) {
+ goto end;
+ }
+ break;
+ case CLIENT_TRANSMISSION_STATUS_FAIL:
+ ret = notification_thread_client_disconnect(client, state);
+ if (ret) {
+ goto end;
+ }
+ break;
+ case CLIENT_TRANSMISSION_STATUS_ERROR:
+ ret = -1;
+ goto end;
+ default:
+ abort();
+ }
+end:
+ return ret;
}
+/* Client lock must be acquired by caller. */
static
-int client_flush_outgoing_queue(struct notification_client *client,
+enum client_transmission_status client_flush_outgoing_queue(
+ struct notification_client *client,
struct notification_thread_state *state)
{
ssize_t ret;
size_t to_send_count;
+ enum client_transmission_status status;
+
+ ASSERT_LOCKED(client->lock);
assert(client->communication.outbound.buffer.size != 0);
to_send_count = client->communication.outbound.buffer.size;
ret = lttcomm_send_unix_sock_non_block(client->socket,
client->communication.outbound.buffer.data,
to_send_count);
- if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) ||
- (ret > 0 && ret < to_send_count)) {
+ if ((ret >= 0 && ret < to_send_count)) {
DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed",
client->socket);
to_send_count -= max(ret, 0);
&client->communication.outbound.buffer,
to_send_count);
if (ret) {
+ status = CLIENT_TRANSMISSION_STATUS_ERROR;
goto error;
}
-
- /*
- * We want to be notified whenever there is buffer space
- * available to send the rest of the payload.
- */
- ret = lttng_poll_mod(&state->events, client->socket,
- CLIENT_POLL_MASK_IN_OUT);
- if (ret) {
- goto error;
- }
+ status = CLIENT_TRANSMISSION_STATUS_QUEUED;
} else if (ret < 0) {
/* Generic error, disconnect the client. */
- ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)",
+ ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)",
client->socket);
- ret = handle_notification_thread_client_disconnect(
- client->socket, state);
- if (ret) {
- goto error;
- }
+ status = CLIENT_TRANSMISSION_STATUS_FAIL;
} else {
/* No error and flushed the queue completely. */
ret = lttng_dynamic_buffer_set_size(
&client->communication.outbound.buffer, 0);
if (ret) {
+ status = CLIENT_TRANSMISSION_STATUS_ERROR;
goto error;
}
- ret = lttng_poll_mod(&state->events, client->socket,
- CLIENT_POLL_MASK_IN);
- if (ret) {
- goto error;
- }
+ status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
+ }
- client->communication.outbound.queued_command_reply = false;
- client->communication.outbound.dropped_notification = false;
+ ret = client_handle_transmission_status(client, status, state);
+ if (ret) {
+ goto error;
}
return 0;
return -1;
}
+/* Client lock must be acquired by caller. */
static
int client_send_command_reply(struct notification_client *client,
struct notification_thread_state *state,
};
char buffer[sizeof(msg) + sizeof(reply)];
+ ASSERT_LOCKED(client->lock);
+
if (client->communication.outbound.queued_command_reply) {
/* Protocol error. */
goto error;
return -1;
}
+static
+int client_handle_message_unknown(struct notification_client *client,
+ struct notification_thread_state *state)
+{
+ int ret;
+
+ pthread_mutex_lock(&client->lock);
+
+ /*
+ * Receiving message header. The function will be called again
+ * once the rest of the message as been received and can be
+ * interpreted.
+ */
+ const struct lttng_notification_channel_message *msg;
+
+ assert(sizeof(*msg) == client->communication.inbound.buffer.size);
+ msg = (const struct lttng_notification_channel_message *)
+ client->communication.inbound.buffer.data;
+
+ if (msg->size == 0 ||
+ msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) {
+ ERR("[notification-thread] Invalid notification channel message: length = %u",
+ msg->size);
+ ret = -1;
+ goto end;
+ }
+
+ switch (msg->type) {
+ case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE:
+ case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE:
+ case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE:
+ break;
+ default:
+ ret = -1;
+ ERR("[notification-thread] Invalid notification channel message: unexpected message type");
+ goto end;
+ }
+
+ client->communication.inbound.bytes_to_receive = msg->size;
+ client->communication.inbound.msg_type =
+ (enum lttng_notification_channel_message_type) msg->type;
+ ret = lttng_dynamic_buffer_set_size(
+ &client->communication.inbound.buffer, msg->size);
+end:
+ pthread_mutex_unlock(&client->lock);
+ return ret;
+}
+
+static
+int client_handle_message_handshake(struct notification_client *client,
+ struct notification_thread_state *state)
+{
+ int ret;
+ struct lttng_notification_channel_command_handshake *handshake_client;
+ const struct lttng_notification_channel_command_handshake handshake_reply = {
+ .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR,
+ .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR,
+ };
+ const struct lttng_notification_channel_message msg_header = {
+ .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE,
+ .size = sizeof(handshake_reply),
+ };
+ enum lttng_notification_channel_status status =
+ LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
+ char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)];
+
+ pthread_mutex_lock(&client->lock);
+
+ memcpy(send_buffer, &msg_header, sizeof(msg_header));
+ memcpy(send_buffer + sizeof(msg_header), &handshake_reply,
+ sizeof(handshake_reply));
+
+ handshake_client =
+ (struct lttng_notification_channel_command_handshake *)
+ client->communication.inbound.buffer
+ .data;
+ client->major = handshake_client->major;
+ client->minor = handshake_client->minor;
+ if (!client->communication.inbound.creds_received) {
+ ERR("[notification-thread] No credentials received from client");
+ ret = -1;
+ goto end;
+ }
+
+ client->uid = LTTNG_SOCK_GET_UID_CRED(
+ &client->communication.inbound.creds);
+ client->gid = LTTNG_SOCK_GET_GID_CRED(
+ &client->communication.inbound.creds);
+ DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i",
+ client->uid, client->gid, (int) client->major,
+ (int) client->minor);
+
+ if (handshake_client->major !=
+ LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) {
+ status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION;
+ }
+
+ ret = lttng_dynamic_buffer_append(
+ &client->communication.outbound.buffer, send_buffer,
+ sizeof(send_buffer));
+ if (ret) {
+ ERR("[notification-thread] Failed to send protocol version to notification channel client");
+ goto end;
+ }
+
+ client->validated = true;
+ client->communication.active = true;
+
+ ret = client_flush_outgoing_queue(client, state);
+ if (ret) {
+ goto end;
+ }
+
+ ret = client_send_command_reply(client, state, status);
+ if (ret) {
+ ERR("[notification-thread] Failed to send reply to notification channel client");
+ goto end;
+ }
+
+ /* Set reception state to receive the next message header. */
+ ret = client_reset_inbound_state(client);
+ if (ret) {
+ ERR("[notification-thread] Failed to reset client communication's inbound state");
+ goto end;
+ }
+
+end:
+ pthread_mutex_unlock(&client->lock);
+ return ret;
+}
+
+static
+int client_handle_message_subscription(
+ struct notification_client *client,
+ enum lttng_notification_channel_message_type msg_type,
+ struct notification_thread_state *state)
+{
+ int ret;
+ struct lttng_condition *condition;
+ enum lttng_notification_channel_status status =
+ LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
+ struct lttng_payload_view condition_view =
+ lttng_payload_view_from_dynamic_buffer(
+ &client->communication.inbound.buffer,
+ 0, -1);
+ size_t expected_condition_size;
+
+ pthread_mutex_lock(&client->lock);
+ expected_condition_size = client->communication.inbound.buffer.size;
+ pthread_mutex_unlock(&client->lock);
+
+ ret = lttng_condition_create_from_payload(&condition_view, &condition);
+ if (ret != expected_condition_size) {
+ ERR("[notification-thread] Malformed condition received from client");
+ goto end;
+ }
+
+ if (msg_type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) {
+ ret = notification_thread_client_subscribe(
+ client, condition, state, &status);
+ } else {
+ ret = notification_thread_client_unsubscribe(
+ client, condition, state, &status);
+ }
+ if (ret) {
+ goto end;
+ }
+
+ pthread_mutex_lock(&client->lock);
+ ret = client_send_command_reply(client, state, status);
+ if (ret) {
+ ERR("[notification-thread] Failed to send reply to notification channel client");
+ goto end_unlock;
+ }
+
+ /* Set reception state to receive the next message header. */
+ ret = client_reset_inbound_state(client);
+ if (ret) {
+ ERR("[notification-thread] Failed to reset client communication's inbound state");
+ goto end_unlock;
+ }
+
+end_unlock:
+ pthread_mutex_unlock(&client->lock);
+end:
+ return ret;
+}
+
static
int client_dispatch_message(struct notification_client *client,
struct notification_thread_state *state)
switch (client->communication.inbound.msg_type) {
case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN:
{
- /*
- * Receiving message header. The function will be called again
- * once the rest of the message as been received and can be
- * interpreted.
- */
- const struct lttng_notification_channel_message *msg;
-
- assert(sizeof(*msg) ==
- client->communication.inbound.buffer.size);
- msg = (const struct lttng_notification_channel_message *)
- client->communication.inbound.buffer.data;
-
- if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) {
- ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size);
- ret = -1;
- goto end;
- }
-
- switch (msg->type) {
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE:
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE:
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE:
- break;
- default:
- ret = -1;
- ERR("[notification-thread] Invalid notification channel message: unexpected message type");
- goto end;
- }
-
- client->communication.inbound.bytes_to_receive = msg->size;
- client->communication.inbound.msg_type =
- (enum lttng_notification_channel_message_type) msg->type;
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.inbound.buffer, msg->size);
- if (ret) {
- goto end;
- }
+ ret = client_handle_message_unknown(client, state);
break;
}
case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE:
{
- struct lttng_notification_channel_command_handshake *handshake_client;
- struct lttng_notification_channel_command_handshake handshake_reply = {
- .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR,
- .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR,
- };
- struct lttng_notification_channel_message msg_header = {
- .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE,
- .size = sizeof(handshake_reply),
- };
- enum lttng_notification_channel_status status =
- LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
- char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)];
-
- memcpy(send_buffer, &msg_header, sizeof(msg_header));
- memcpy(send_buffer + sizeof(msg_header), &handshake_reply,
- sizeof(handshake_reply));
-
- handshake_client =
- (struct lttng_notification_channel_command_handshake *)
- client->communication.inbound.buffer.data;
- client->major = handshake_client->major;
- client->minor = handshake_client->minor;
- if (!client->communication.inbound.creds_received) {
- ERR("[notification-thread] No credentials received from client");
- ret = -1;
- goto end;
- }
-
- client->uid = LTTNG_SOCK_GET_UID_CRED(
- &client->communication.inbound.creds);
- client->gid = LTTNG_SOCK_GET_GID_CRED(
- &client->communication.inbound.creds);
- DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i",
- client->uid, client->gid, (int) client->major,
- (int) client->minor);
-
- if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) {
- status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION;
- }
-
- ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer,
- send_buffer, sizeof(send_buffer));
- if (ret) {
- ERR("[notification-thread] Failed to send protocol version to notification channel client");
- goto end;
- }
-
- ret = client_flush_outgoing_queue(client, state);
- if (ret) {
- goto end;
- }
-
- ret = client_send_command_reply(client, state, status);
- if (ret) {
- ERR("[notification-thread] Failed to send reply to notification channel client");
- goto end;
- }
-
- /* Set reception state to receive the next message header. */
- ret = client_reset_inbound_state(client);
- if (ret) {
- ERR("[notification-thread] Failed to reset client communication's inbound state");
- goto end;
- }
- client->validated = true;
+ ret = client_handle_message_handshake(client, state);
break;
}
case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE:
case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE:
{
- struct lttng_condition *condition;
- enum lttng_notification_channel_status status =
- LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
- const struct lttng_buffer_view condition_view =
- lttng_buffer_view_from_dynamic_buffer(
- &client->communication.inbound.buffer,
- 0, -1);
- size_t expected_condition_size =
- client->communication.inbound.buffer.size;
-
- ret = lttng_condition_create_from_buffer(&condition_view,
- &condition);
- if (ret != expected_condition_size) {
- ERR("[notification-thread] Malformed condition received from client");
- goto end;
- }
-
- if (client->communication.inbound.msg_type ==
- LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) {
- ret = notification_thread_client_subscribe(client,
- condition, state, &status);
- } else {
- ret = notification_thread_client_unsubscribe(client,
- condition, state, &status);
- }
- if (ret) {
- goto end;
- }
-
- ret = client_send_command_reply(client, state, status);
- if (ret) {
- ERR("[notification-thread] Failed to send reply to notification channel client");
- goto end;
- }
-
- /* Set reception state to receive the next message header. */
- ret = client_reset_inbound_state(client);
- if (ret) {
- ERR("[notification-thread] Failed to reset client communication's inbound state");
- goto end;
- }
+ ret = client_handle_message_subscription(client,
+ client->communication.inbound.msg_type, state);
break;
}
default:
struct notification_client *client;
ssize_t recv_ret;
size_t offset;
+ bool message_is_complete = false;
client = get_client_from_socket(socket, state);
if (!client) {
goto end;
}
+ pthread_mutex_lock(&client->lock);
offset = client->communication.inbound.buffer.size -
client->communication.inbound.bytes_to_receive;
if (client->communication.inbound.expect_creds) {
client->communication.inbound.buffer.data + offset,
client->communication.inbound.bytes_to_receive);
}
+ if (recv_ret >= 0) {
+ client->communication.inbound.bytes_to_receive -= recv_ret;
+ message_is_complete = client->communication.inbound
+ .bytes_to_receive == 0;
+ }
+ pthread_mutex_unlock(&client->lock);
if (recv_ret < 0) {
goto error_disconnect_client;
}
- client->communication.inbound.bytes_to_receive -= recv_ret;
- if (client->communication.inbound.bytes_to_receive == 0) {
+ if (message_is_complete) {
ret = client_dispatch_message(client, state);
if (ret) {
/*
*/
goto error_disconnect_client;
}
- } else {
- goto end;
}
end:
return ret;
error_disconnect_client:
- ret = handle_notification_thread_client_disconnect(socket, state);
+ pthread_mutex_lock(&client->lock);
+ ret = notification_thread_client_disconnect(client, state);
+ pthread_mutex_unlock(&client->lock);
return ret;
}
goto end;
}
+ pthread_mutex_lock(&client->lock);
ret = client_flush_outgoing_queue(client, state);
+ pthread_mutex_unlock(&client->lock);
if (ret) {
goto end;
}
* forego this double-multiplication or it could be performed
* as fixed-point math.
*
- * Note that caching should accomodate the case where the
+ * Note that caching should accommodates the case where the
* condition applies to multiple channels (i.e. don't assume
* that all channels matching my_chann* have the same size...)
*/
}
static
-int evaluate_condition(const struct lttng_condition *condition,
+int evaluate_buffer_condition(const struct lttng_condition *condition,
struct lttng_evaluation **evaluation,
const struct notification_thread_state *state,
const struct channel_state_sample *previous_sample,
break;
case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
*evaluation = lttng_evaluation_session_consumed_size_create(
- condition_type,
latest_session_consumed_total);
break;
default:
}
static
-int client_enqueue_dropped_notification(struct notification_client *client,
- struct notification_thread_state *state)
+int client_enqueue_dropped_notification(struct notification_client *client)
{
int ret;
struct lttng_notification_channel_message msg = {
.size = 0,
};
+ ASSERT_LOCKED(client->lock);
+
ret = lttng_dynamic_buffer_append(
&client->communication.outbound.buffer, &msg,
sizeof(msg));
return ret;
}
+/*
+ * Permission checks relative to notification channel clients are performed
+ * here. Notice how object, client, and trigger credentials are involved in
+ * this check.
+ *
+ * The `object` credentials are the credentials associated with the "subject"
+ * of a condition. For instance, a `rotation completed` condition applies
+ * to a session. When that condition is met, it will produce an evaluation
+ * against a session. Hence, in this case, the `object` credentials are the
+ * credentials of the "subject" session.
+ *
+ * The `trigger` credentials are the credentials of the user that registered the
+ * trigger.
+ *
+ * The `client` credentials are the credentials of the user that created a given
+ * notification channel.
+ *
+ * In terms of visibility, it is expected that non-privilieged users can only
+ * register triggers against "their" objects (their own sessions and
+ * applications they are allowed to interact with). They can then open a
+ * notification channel and subscribe to notifications associated with those
+ * triggers.
+ *
+ * As for privilieged users, they can register triggers against the objects of
+ * other users. They can then subscribe to the notifications associated to their
+ * triggers. Privilieged users _can't_ subscribe to the notifications of
+ * triggers owned by other users; they must create their own triggers.
+ *
+ * This is more a concern of usability than security. It would be difficult for
+ * a root user reliably subscribe to a specific set of conditions without
+ * interference from external users (those could, for instance, unregister
+ * their triggers).
+ */
static
-int send_evaluation_to_clients(struct lttng_trigger *trigger,
- struct lttng_evaluation *evaluation,
+int send_evaluation_to_clients(const struct lttng_trigger *trigger,
+ const struct lttng_evaluation *evaluation,
struct notification_client_list* client_list,
struct notification_thread_state *state,
- uid_t channel_uid, gid_t channel_gid)
+ uid_t object_uid, gid_t object_gid)
{
int ret = 0;
- struct lttng_dynamic_buffer msg_buffer;
+ struct lttng_payload msg_payload;
struct notification_client_list_element *client_list_element, *tmp;
- struct lttng_notification *notification;
- struct lttng_condition *condition;
- ssize_t expected_notification_size, notification_size;
- struct lttng_notification_channel_message msg;
-
- lttng_dynamic_buffer_init(&msg_buffer);
-
- condition = lttng_trigger_get_condition(trigger);
- assert(condition);
-
- notification = lttng_notification_create(condition, evaluation);
- if (!notification) {
- ret = -1;
- goto end;
- }
+ const struct lttng_notification notification = {
+ .condition = (struct lttng_condition *) lttng_trigger_get_const_condition(trigger),
+ .evaluation = (struct lttng_evaluation *) evaluation,
+ };
+ struct lttng_notification_channel_message msg_header = {
+ .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION,
+ };
+ const struct lttng_credentials *trigger_creds = lttng_trigger_get_credentials(trigger);
- expected_notification_size = lttng_notification_serialize(notification,
- NULL);
- if (expected_notification_size < 0) {
- ERR("[notification-thread] Failed to get size of serialized notification");
- ret = -1;
- goto end;
- }
+ lttng_payload_init(&msg_payload);
- msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION;
- msg.size = (uint32_t) expected_notification_size;
- ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg));
+ ret = lttng_dynamic_buffer_append(&msg_payload.buffer, &msg_header,
+ sizeof(msg_header));
if (ret) {
goto end;
}
- ret = lttng_dynamic_buffer_set_size(&msg_buffer,
- msg_buffer.size + expected_notification_size);
+ ret = lttng_notification_serialize(¬ification, &msg_payload);
if (ret) {
- goto end;
- }
-
- notification_size = lttng_notification_serialize(notification,
- msg_buffer.data + sizeof(msg));
- if (notification_size != expected_notification_size) {
ERR("[notification-thread] Failed to serialize notification");
ret = -1;
goto end;
}
+ /* Update payload size. */
+ ((struct lttng_notification_channel_message *) msg_payload.buffer.data)
+ ->size = (uint32_t)(
+ msg_payload.buffer.size - sizeof(msg_header));
+
+ pthread_mutex_lock(&client_list->lock);
cds_list_for_each_entry_safe(client_list_element, tmp,
&client_list->list, node) {
struct notification_client *client =
client_list_element->client;
- if (client->uid != channel_uid && client->gid != channel_gid &&
+ ret = 0;
+ pthread_mutex_lock(&client->lock);
+ if (client->uid != object_uid && client->gid != object_gid &&
client->uid != 0) {
/* Client is not allowed to monitor this channel. */
- DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel");
- continue;
+ DBG("[notification-thread] Skipping client at it does not have the object permission to receive notification for this trigger");
+ goto unlock_client;
+ }
+
+ if (client->uid != trigger_creds->uid && client->gid != trigger_creds->gid) {
+ DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger");
+ goto unlock_client;
}
DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)",
- client->socket, msg_buffer.size);
+ client->socket, msg_payload.buffer.size);
if (client->communication.outbound.buffer.size) {
/*
* Outgoing data is already buffered for this client;
if (!client->communication.outbound.dropped_notification) {
client->communication.outbound.dropped_notification = true;
ret = client_enqueue_dropped_notification(
- client, state);
+ client);
if (ret) {
- goto end;
+ goto unlock_client;
}
}
- continue;
+ goto unlock_client;
}
ret = lttng_dynamic_buffer_append_buffer(
&client->communication.outbound.buffer,
- &msg_buffer);
+ &msg_payload.buffer);
if (ret) {
- goto end;
+ goto unlock_client;
}
ret = client_flush_outgoing_queue(client, state);
if (ret) {
- goto end;
+ goto unlock_client;
+ }
+unlock_client:
+ pthread_mutex_unlock(&client->lock);
+ if (ret) {
+ goto end_unlock_list;
}
}
ret = 0;
+
+end_unlock_list:
+ pthread_mutex_unlock(&client_list->lock);
end:
- lttng_notification_destroy(notification);
- lttng_dynamic_buffer_reset(&msg_buffer);
+ lttng_payload_reset(&msg_payload);
return ret;
}
trigger_list = caa_container_of(node, struct lttng_channel_trigger_list,
channel_triggers_ht_node);
cds_list_for_each_entry(trigger_list_element, &trigger_list->list,
- node) {
- struct lttng_condition *condition;
- struct lttng_action *action;
- struct lttng_trigger *trigger;
- struct notification_client_list *client_list;
+ node) {
+ const struct lttng_condition *condition;
+ const struct lttng_action *action;
+ const struct lttng_trigger *trigger;
+ struct notification_client_list *client_list = NULL;
struct lttng_evaluation *evaluation = NULL;
+ bool client_list_is_empty;
+ ret = 0;
trigger = trigger_list_element->trigger;
- condition = lttng_trigger_get_condition(trigger);
+ condition = lttng_trigger_get_const_condition(trigger);
assert(condition);
- action = lttng_trigger_get_action(trigger);
+ action = lttng_trigger_get_const_action(trigger);
/* Notify actions are the only type currently supported. */
- assert(lttng_action_get_type(action) ==
+ assert(lttng_action_get_type_const(action) ==
LTTNG_ACTION_TYPE_NOTIFY);
/*
* Check if any client is subscribed to the result of this
* evaluation.
*/
- cds_lfht_lookup(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- match_client_list,
- trigger,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
-
- client_list = caa_container_of(node,
- struct notification_client_list,
- notification_trigger_ht_node);
- if (cds_list_empty(&client_list->list)) {
+ client_list = get_client_list_from_condition(state, condition);
+ assert(client_list);
+ client_list_is_empty = cds_list_empty(&client_list->list);
+ if (client_list_is_empty) {
/*
* No clients interested in the evaluation's result,
* skip it.
*/
- continue;
+ goto put_list;
}
- ret = evaluate_condition(condition, &evaluation, state,
+ ret = evaluate_buffer_condition(condition, &evaluation, state,
previous_sample_available ? &previous_sample : NULL,
&latest_sample,
previous_session_consumed_total,
latest_session_consumed_total,
channel_info);
if (caa_unlikely(ret)) {
- goto end_unlock;
+ goto put_list;
}
if (caa_likely(!evaluation)) {
- continue;
+ goto put_list;
}
/* Dispatch evaluation result to all clients. */
channel_info->session_info->uid,
channel_info->session_info->gid);
lttng_evaluation_destroy(evaluation);
+put_list:
+ notification_client_list_put(client_list);
if (caa_unlikely(ret)) {
- goto end_unlock;
+ break;
}
}
end_unlock: