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 {
+ 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. */
struct cds_lfht_node client_id_ht_node;
struct {
/*
- * If a client's communication is inactive, it means a fatal
- * error (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.
+ * 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 {
assert(condition_key);
client_list = caa_container_of(node, struct notification_client_list,
- notification_trigger_ht_node);
+ notification_trigger_clients_ht_node);
condition = lttng_trigger_get_const_condition(client_list->trigger);
return !!lttng_condition_is_equal(condition_key, condition);
return NULL;
}
-/* RCU read lock must be held by the caller. */
+static
+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,
{
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;
+ }
- return node ? caa_container_of(node,
- struct notification_client_list,
- notification_trigger_ht_node) : NULL;
+ rcu_read_unlock();
+ return list;
}
-/* This function must be called with the RCU read lock held. */
static
int evaluate_channel_condition_for_client(
const struct lttng_condition *condition,
struct channel_state_sample *last_sample = NULL;
struct lttng_channel_trigger_list *channel_trigger_list = NULL;
+ rcu_read_lock();
+
/* Find the channel associated with the condition. */
cds_lfht_for_each_entry(state->channel_triggers_ht, &iter,
channel_trigger_list, channel_triggers_ht_node) {
*session_uid = channel_info->session_info->uid;
*session_gid = channel_info->session_info->gid;
end:
+ rcu_read_unlock();
return ret;
}
return session_name;
}
-/* This function must be called with the RCU read lock held. */
static
int evaluate_session_condition_for_client(
const struct lttng_condition *condition,
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. */
end_session_put:
session_info_put(session_info);
end:
+ rcu_read_unlock();
return ret;
}
-/* This function must be called with the RCU read lock held. */
static
int evaluate_condition_for_client(const struct lttng_trigger *trigger,
const struct lttng_condition *condition,
{
int ret;
struct lttng_evaluation *evaluation = NULL;
- struct notification_client_list client_list = { 0 };
+ 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;
* Create a temporary client list with the client currently
* subscribing.
*/
- cds_lfht_node_init(&client_list.notification_trigger_ht_node);
+ cds_lfht_node_init(&client_list.notification_trigger_clients_ht_node);
CDS_INIT_LIST_HEAD(&client_list.list);
client_list.trigger = trigger;
enum lttng_notification_channel_status *_status)
{
int ret = 0;
- struct notification_client_list *client_list;
+ 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.
*/
* since this trigger is not registered yet.
*/
free(client_list_element);
- goto end_unlock;
+ goto end;
}
/*
* 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;
free(client_list_element);
- goto end_unlock;
+ 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);
* Remove the client from the list of clients interested the trigger
* matching the condition.
*/
- rcu_read_lock();
client_list = get_client_list_from_condition(state, condition);
if (!client_list) {
- goto end_unlock;
+ goto end;
}
+ 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) {
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);
+ pthread_mutex_destroy(&client->lock);
call_rcu(&client->rcu_node, free_notification_client_rcu);
}
return client;
}
-/*
- * Call with rcu_read_lock held (and hold for the lifetime of the returned
- * client pointer).
- */
-static
-struct notification_client *get_client_from_id(notification_client_id id,
- struct notification_thread_state *state)
-{
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
- struct notification_client *client = NULL;
-
- cds_lfht_lookup(state->client_id_ht,
- hash_client_id(id),
- match_client_id,
- &id,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- goto end;
- }
-
- client = caa_container_of(node, struct notification_client,
- client_id_ht_node);
-end:
- return client;
-}
-
static
bool buffer_usage_condition_applies_to_channel(
const struct lttng_condition *condition,
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);
client_list = get_client_list_from_condition(state, condition);
assert(client_list);
- if (cds_list_empty(&client_list->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.
/* Internal error */
ret = -1;
cmd_result = LTTNG_ERR_UNK;
- goto end;
+ goto put_list;
}
/* Dispatch evaluation result to all clients. */
session_info->uid,
session_info->gid);
lttng_evaluation_destroy(evaluation);
+put_list:
+ notification_client_list_put(client_list);
if (caa_unlikely(ret)) {
- goto end;
+ break;
}
}
end:
* 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);
-
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_free_client_list;
+ goto error_put_client_list;
}
break;
case LTTNG_OBJECT_TYPE_CHANNEL:
*/
ret = bind_trigger_to_matching_channels(trigger, state);
if (ret) {
- goto error_free_client_list;
+ goto error_put_client_list;
}
break;
case LTTNG_OBJECT_TYPE_NONE:
default:
ERR("[notification-thread] Unknown object type on which to bind a newly registered trigger was encountered");
ret = -1;
- goto error_free_client_list;
+ 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:
return ret;
}
-static
-void free_notification_client_list_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct notification_client_list,
- rcu_node));
-}
-
static
void free_lttng_trigger_ht_element_rcu(struct rcu_head *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);
client_list = get_client_list_from_condition(state, condition);
assert(client_list);
- 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,
- &client_list->notification_trigger_ht_node);
- call_rcu(&client_list->rcu_node, free_notification_client_list_rcu);
+ /* 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,
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;
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);
- cds_lfht_del(state->client_id_ht,
- &client->client_id_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;
}
return error_occurred ? -1 : 0;
}
+/* Client lock must be acquired by caller. */
static
int client_flush_outgoing_queue(struct notification_client *client,
struct notification_thread_state *state)
ssize_t ret;
size_t to_send_count;
+ ASSERT_LOCKED(client->lock);
+
assert(client->communication.outbound.buffer.size != 0);
to_send_count = client->communication.outbound.buffer.size;
DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue",
/* Generic error, disconnect the client. */
ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)",
client->socket);
- ret = handle_notification_thread_client_disconnect(
- client->socket, state);
+ ret = notification_thread_client_disconnect(client, state);
if (ret) {
goto error;
}
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;
- client->communication.active = 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;
- struct lttng_payload_view condition_view =
- lttng_payload_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_payload(&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;
}
.size = 0,
};
+ ASSERT_LOCKED(client->lock);
+
ret = lttng_dynamic_buffer_append(
&client->communication.outbound.buffer, &msg,
sizeof(msg));
}
/* Update payload size. */
- ((struct lttng_notification_channel_message * ) msg_payload.buffer.data)->size =
- (uint32_t) (msg_payload.buffer.size - sizeof(msg_header));
+ ((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;
+ 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 object permission to receive notification for this trigger");
- continue;
+ 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");
- continue;
+ goto unlock_client;
}
DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)",
ret = client_enqueue_dropped_notification(
client);
if (ret) {
- goto end;
+ goto unlock_client;
}
}
- continue;
+ goto unlock_client;
}
ret = lttng_dynamic_buffer_append_buffer(
&client->communication.outbound.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_payload_reset(&msg_payload);
return ret;
const struct lttng_condition *condition;
const struct lttng_action *action;
const struct lttng_trigger *trigger;
- struct notification_client_list *client_list;
+ 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_const_condition(trigger);
assert(condition);
*/
client_list = get_client_list_from_condition(state, condition);
assert(client_list);
- if (cds_list_empty(&client_list->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_buffer_condition(condition, &evaluation, state,
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:
projects / deliverable / lttng-tools.git / commitdiff
