struct lttng_trigger_list_element {
/* No ownership of the trigger object is assumed. */
- const struct lttng_trigger *trigger;
+ struct lttng_trigger *trigger;
struct cds_list_head node;
};
struct cds_list_head node;
};
-struct notification_client_list_element {
- struct notification_client *client;
- 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;
- /* 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;
- uid_t uid;
- gid_t gid;
- /*
- * Indicates if the credentials and versions of the client have been
- * checked.
- */
- bool validated;
- /*
- * Conditions to which the client's notification channel is subscribed.
- * List of struct lttng_condition_list_node. The condition member is
- * owned by the client.
- */
- 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
- * buffers' "size" is set to contain the current
- * message's complete payload.
- */
- struct lttng_dynamic_buffer buffer;
- /* Bytes left to receive for the current message. */
- size_t bytes_to_receive;
- /* Type of the message being received. */
- enum lttng_notification_channel_message_type msg_type;
- /*
- * Indicates whether or not credentials are expected
- * from the client.
- */
- bool expect_creds;
- /*
- * Indicates whether or not credentials were received
- * from the client.
- */
- bool creds_received;
- /* Only used during credentials reception. */
- lttng_sock_cred creds;
- } inbound;
- struct {
- /*
- * Indicates whether or not a notification addressed to
- * this client was dropped because a command reply was
- * already buffered.
- *
- * A notification is dropped whenever the buffer is not
- * empty.
- */
- bool dropped_notification;
- /*
- * Indicates whether or not a command reply is already
- * buffered. In this case, it means that the client is
- * not consuming command replies before emitting a new
- * one. This could be caused by a protocol error or a
- * misbehaving/malicious client.
- */
- bool queued_command_reply;
- struct lttng_dynamic_buffer buffer;
- } outbound;
- } communication;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
struct channel_state_sample {
struct channel_key key;
struct cds_lfht_node channel_state_ht_node;
struct lttng_session_trigger_list *list);
static
int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
- const struct lttng_trigger *trigger);
+ struct lttng_trigger *trigger);
+static
+int client_handle_transmission_status(
+ struct notification_client *client,
+ enum client_transmission_status transmission_status,
+ struct notification_thread_state *state);
static
int match_client_socket(struct cds_lfht_node *node, const void *key)
return NULL;
}
-static
+LTTNG_HIDDEN
bool notification_client_list_get(struct notification_client_list *list)
{
return urcu_ref_get_unless_zero(&list->ref);
rcu_read_unlock();
}
-static
+LTTNG_HIDDEN
void notification_client_list_put(struct notification_client_list *list)
{
if (!list) {
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,
static
int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
- const struct lttng_trigger *trigger)
+ struct lttng_trigger *trigger)
{
int ret = 0;
struct lttng_trigger_list_element *new_element =
struct lttng_session_trigger_list *trigger_list;
struct lttng_trigger_list_element *trigger_list_element;
struct session_info *session_info;
+ const struct lttng_credentials session_creds = {
+ .uid = session_uid,
+ .gid = session_gid,
+ };
rcu_read_lock();
node) {
const struct lttng_condition *condition;
const struct lttng_action *action;
- const struct lttng_trigger *trigger;
+ 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;
+ enum action_executor_status executor_status;
trigger = trigger_list_element->trigger;
condition = lttng_trigger_get_const_condition(trigger);
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);
+ /*
+ * Ownership of `evaluation` transferred to the action executor
+ * no matter the result.
+ */
+ executor_status = action_executor_enqueue(state->executor,
+ trigger, evaluation, &session_creds,
+ client_list);
+ evaluation = NULL;
+ switch (executor_status) {
+ case ACTION_EXECUTOR_STATUS_OK:
+ break;
+ case ACTION_EXECUTOR_STATUS_ERROR:
+ case ACTION_EXECUTOR_STATUS_INVALID:
+ /*
+ * TODO Add trigger identification (name/id) when
+ * it is added to the API.
+ */
+ ERR("Fatal error occurred while enqueuing action associated with session rotation trigger");
+ ret = -1;
+ goto put_list;
+ case ACTION_EXECUTOR_STATUS_OVERFLOW:
+ /*
+ * TODO Add trigger identification (name/id) when
+ * it is added to the API.
+ *
+ * Not a fatal error.
+ */
+ WARN("No space left when enqueuing action associated with session rotation trigger");
+ ret = 0;
+ goto put_list;
+ default:
+ abort();
+ }
+
put_list:
notification_client_list_put(client_list);
if (caa_unlikely(ret)) {
/* Must be called with RCU read lock held. */
static
-int bind_trigger_to_matching_session(const struct lttng_trigger *trigger,
+int bind_trigger_to_matching_session(struct lttng_trigger *trigger,
struct notification_thread_state *state)
{
int ret = 0;
/* Must be called with RCU read lock held. */
static
-int bind_trigger_to_matching_channels(const struct lttng_trigger *trigger,
+int bind_trigger_to_matching_channels(struct lttng_trigger *trigger,
struct notification_thread_state *state)
{
int ret = 0;
cmd->reply_code = LTTNG_OK;
ret = 1;
goto end;
+ case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE:
+ {
+ const enum client_transmission_status client_status =
+ cmd->parameters.client_communication_update
+ .status;
+ const notification_client_id client_id =
+ cmd->parameters.client_communication_update.id;
+ struct notification_client *client;
+
+ rcu_read_lock();
+ client = get_client_from_id(client_id, state);
+
+ if (!client) {
+ /*
+ * Client error was probably already picked-up by the
+ * notification thread or it has disconnected
+ * gracefully while this command was queued.
+ */
+ DBG("Failed to find notification client to update communication status, client id = %" PRIu64,
+ client_id);
+ ret = 0;
+ } else {
+ pthread_mutex_lock(&client->lock);
+ ret = client_handle_transmission_status(
+ client, client_status, state);
+ pthread_mutex_unlock(&client->lock);
+ }
+ rcu_read_unlock();
+ break;
+ }
default:
ERR("[notification-thread] Unknown internal command received");
goto error_unlock;
/* Client lock must be acquired by caller. */
static
enum client_transmission_status client_flush_outgoing_queue(
- struct notification_client *client,
- struct notification_thread_state *state)
+ struct notification_client *client)
{
ssize_t ret;
size_t to_send_count;
ASSERT_LOCKED(client->lock);
+ if (!client->communication.active) {
+ status = CLIENT_TRANSMISSION_STATUS_FAIL;
+ goto end;
+ }
+
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",
&client->communication.outbound.buffer,
to_send_count);
if (ret) {
- status = CLIENT_TRANSMISSION_STATUS_ERROR;
goto error;
}
status = CLIENT_TRANSMISSION_STATUS_QUEUED;
ret = lttng_dynamic_buffer_set_size(
&client->communication.outbound.buffer, 0);
if (ret) {
- status = CLIENT_TRANSMISSION_STATUS_ERROR;
goto error;
}
status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
}
-
- ret = client_handle_transmission_status(client, status, state);
- if (ret) {
- goto error;
- }
-
- return 0;
+end:
+ return status;
error:
- return -1;
+ return CLIENT_TRANSMISSION_STATUS_ERROR;
}
/* Client lock must be acquired by caller. */
.size = sizeof(reply),
};
char buffer[sizeof(msg) + sizeof(reply)];
+ enum client_transmission_status transmission_status;
ASSERT_LOCKED(client->lock);
goto error;
}
- ret = client_flush_outgoing_queue(client, state);
+ transmission_status = client_flush_outgoing_queue(client);
+ ret = client_handle_transmission_status(
+ client, transmission_status, state);
if (ret) {
goto error;
}
enum lttng_notification_channel_status status =
LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)];
+ enum client_transmission_status transmission_status;
pthread_mutex_lock(&client->lock);
client->validated = true;
client->communication.active = true;
- ret = client_flush_outgoing_queue(client, state);
+ transmission_status = client_flush_outgoing_queue(client);
+ ret = client_handle_transmission_status(
+ client, transmission_status, state);
if (ret) {
goto end;
}
{
int ret;
struct notification_client *client;
+ enum client_transmission_status transmission_status;
client = get_client_from_socket(socket, state);
if (!client) {
}
pthread_mutex_lock(&client->lock);
- ret = client_flush_outgoing_queue(client, state);
+ transmission_status = client_flush_outgoing_queue(client);
+ ret = client_handle_transmission_status(
+ client, transmission_status, state);
pthread_mutex_unlock(&client->lock);
if (ret) {
goto end;
}
static
-int client_enqueue_dropped_notification(struct notification_client *client)
+int client_notification_overflow(struct notification_client *client)
{
- int ret;
- struct lttng_notification_channel_message msg = {
+ int ret = 0;
+ const struct lttng_notification_channel_message msg = {
.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED,
- .size = 0,
};
ASSERT_LOCKED(client->lock);
+ DBG("Dropping notification addressed to client (socket fd = %i)",
+ client->socket);
+ if (client->communication.outbound.dropped_notification) {
+ /*
+ * The client already has a "notification dropped" message
+ * in its outgoing queue. Nothing to do since all
+ * of those messages are coalesced.
+ */
+ goto end;
+ }
+
+ client->communication.outbound.dropped_notification = true;
ret = lttng_dynamic_buffer_append(
&client->communication.outbound.buffer, &msg,
sizeof(msg));
+ if (ret) {
+ PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue",
+ client->socket);
+ }
+end:
return ret;
}
+static int client_handle_transmission_status_wrapper(
+ struct notification_client *client,
+ enum client_transmission_status status,
+ void *user_data)
+{
+ return client_handle_transmission_status(client, status,
+ (struct notification_thread_state *) user_data);
+}
+
+static
+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 object_uid, gid_t object_gid)
+{
+ return notification_client_list_send_evaluation(client_list,
+ lttng_trigger_get_const_condition(trigger), evaluation,
+ lttng_trigger_get_credentials(trigger),
+ &(struct lttng_credentials){
+ .uid = object_uid, .gid = object_gid},
+ client_handle_transmission_status_wrapper, state);
+}
+
/*
* Permission checks relative to notification channel clients are performed
* here. Notice how object, client, and trigger credentials are involved in
* interference from external users (those could, for instance, unregister
* their triggers).
*/
-static
-int send_evaluation_to_clients(const struct lttng_trigger *trigger,
+LTTNG_HIDDEN
+int notification_client_list_send_evaluation(
+ struct notification_client_list *client_list,
+ const struct lttng_condition *condition,
const struct lttng_evaluation *evaluation,
- struct notification_client_list* client_list,
- struct notification_thread_state *state,
- uid_t object_uid, gid_t object_gid)
+ const struct lttng_credentials *trigger_creds,
+ const struct lttng_credentials *source_object_creds,
+ report_client_transmission_result_cb client_report,
+ void *user_data)
{
int ret = 0;
struct lttng_payload msg_payload;
struct notification_client_list_element *client_list_element, *tmp;
const struct lttng_notification notification = {
- .condition = (struct lttng_condition *) lttng_trigger_get_const_condition(trigger),
+ .condition = (struct lttng_condition *) condition,
.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);
lttng_payload_init(&msg_payload);
pthread_mutex_lock(&client_list->lock);
cds_list_for_each_entry_safe(client_list_element, tmp,
&client_list->list, node) {
+ enum client_transmission_status transmission_status;
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");
- goto unlock_client;
+ if (source_object_creds) {
+ if (client->uid != source_object_creds->uid &&
+ client->gid != source_object_creds->gid &&
+ client->uid != 0) {
+ /*
+ * Client is not allowed to monitor this
+ * object.
+ */
+ 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) {
* notification since the socket spilled-over to the
* queue.
*/
- DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)",
- client->socket);
- if (!client->communication.outbound.dropped_notification) {
- client->communication.outbound.dropped_notification = true;
- ret = client_enqueue_dropped_notification(
- client);
- if (ret) {
- goto unlock_client;
- }
+ ret = client_notification_overflow(client);
+ if (ret) {
+ goto unlock_client;
}
- goto unlock_client;
}
ret = lttng_dynamic_buffer_append_buffer(
goto unlock_client;
}
- ret = client_flush_outgoing_queue(client, state);
+ transmission_status = client_flush_outgoing_queue(client);
+ ret = client_report(client, transmission_status, user_data);
if (ret) {
goto unlock_client;
}
bool previous_sample_available = false;
struct channel_state_sample previous_sample, latest_sample;
uint64_t previous_session_consumed_total, latest_session_consumed_total;
+ struct lttng_credentials channel_creds;
/*
* The monitoring pipe only holds messages smaller than PIPE_BUF,
goto end_unlock;
}
+ channel_creds = (typeof(channel_creds)) {
+ .uid = channel_info->session_info->uid,
+ .gid = channel_info->session_info->gid,
+ };
+
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) {
const struct lttng_condition *condition;
const struct lttng_action *action;
- const struct lttng_trigger *trigger;
+ struct lttng_trigger *trigger;
struct notification_client_list *client_list = NULL;
struct lttng_evaluation *evaluation = NULL;
bool client_list_is_empty;
+ enum action_executor_status executor_status;
ret = 0;
trigger = trigger_list_element->trigger;
goto put_list;
}
- /* Dispatch evaluation result to all clients. */
- ret = send_evaluation_to_clients(trigger_list_element->trigger,
- evaluation, client_list, state,
- channel_info->session_info->uid,
- channel_info->session_info->gid);
- lttng_evaluation_destroy(evaluation);
+ /*
+ * Ownership of `evaluation` transferred to the action executor
+ * no matter the result.
+ */
+ executor_status = action_executor_enqueue(state->executor,
+ trigger, evaluation, &channel_creds,
+ client_list);
+ evaluation = NULL;
+ switch (executor_status) {
+ case ACTION_EXECUTOR_STATUS_OK:
+ break;
+ case ACTION_EXECUTOR_STATUS_ERROR:
+ case ACTION_EXECUTOR_STATUS_INVALID:
+ /*
+ * TODO Add trigger identification (name/id) when
+ * it is added to the API.
+ */
+ ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
+ ret = -1;
+ goto put_list;
+ case ACTION_EXECUTOR_STATUS_OVERFLOW:
+ /*
+ * TODO Add trigger identification (name/id) when
+ * it is added to the API.
+ *
+ * Not a fatal error.
+ */
+ WARN("No space left when enqueuing action associated with buffer-condition trigger");
+ ret = 0;
+ goto put_list;
+ default:
+ abort();
+ }
+
put_list:
notification_client_list_put(client_list);
if (caa_unlikely(ret)) {
projects / lttng-tools.git / blobdiff