/*
- * 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.
*/
+#include "lttng/action/action.h"
+#include "lttng/trigger/trigger-internal.h"
#define _LGPL_SOURCE
#include <urcu.h>
#include <urcu/rculfhash.h>
#include <lttng/condition/session-consumed-size-internal.h>
#include <lttng/condition/session-rotation-internal.h>
#include <lttng/notification/channel-internal.h>
+#include <lttng/trigger/trigger-internal.h>
#include <time.h>
#include <unistd.h>
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 list;
/* Node in the channel_triggers_ht */
struct cds_lfht_node channel_triggers_ht_node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
/*
struct lttng_trigger_ht_element {
struct lttng_trigger *trigger;
struct cds_lfht_node node;
+ struct cds_lfht_node node_by_name_uid;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct lttng_condition_list_element {
struct cds_list_head node;
};
-struct notification_client_list_element {
- struct notification_client *client;
- struct cds_list_head node;
-};
-
-struct notification_client_list {
- const struct lttng_trigger *trigger;
- struct cds_list_head list;
- struct cds_lfht_node notification_trigger_ht_node;
-};
-
-struct notification_client {
- 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 {
- 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;
-};
-
struct channel_state_sample {
struct channel_key key;
struct cds_lfht_node channel_state_ht_node;
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);
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
+void free_lttng_trigger_ht_element_rcu(struct rcu_head *node);
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
}
static
-int match_condition(struct cds_lfht_node *node, const void *key)
+int match_trigger(struct cds_lfht_node *node, const void *key)
{
- struct lttng_condition *condition_key = (struct lttng_condition *) key;
- struct lttng_trigger_ht_element *trigger;
- struct lttng_condition *condition;
+ struct lttng_trigger *trigger_key = (struct lttng_trigger *) key;
+ struct lttng_trigger_ht_element *trigger_ht_element;
- trigger = caa_container_of(node, struct lttng_trigger_ht_element,
+ trigger_ht_element = caa_container_of(node, struct lttng_trigger_ht_element,
node);
- condition = lttng_trigger_get_condition(trigger->trigger);
- assert(condition);
- return !!lttng_condition_is_equal(condition_key, condition);
+ return !!lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger);
}
static
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 !strcmp(session_info->name, name);
}
+/*
+ * Match trigger based on name and credentials only.
+ * Name duplication is NOT allowed for the same uid.
+ */
+static
+int match_trigger_by_name_uid(struct cds_lfht_node *node,
+ const void *key)
+{
+ bool match = false;
+ const char *name;
+ const char *key_name;
+ enum lttng_trigger_status status;
+ const struct lttng_credentials *key_creds;
+ const struct lttng_credentials *node_creds;
+ const struct lttng_trigger *trigger_key =
+ (const struct lttng_trigger *) key;
+ const struct lttng_trigger_ht_element *trigger_ht_element =
+ caa_container_of(node,
+ struct lttng_trigger_ht_element,
+ node_by_name_uid);
+
+ status = lttng_trigger_get_name(trigger_ht_element->trigger, &name);
+ assert(status == LTTNG_TRIGGER_STATUS_OK);
+
+ status = lttng_trigger_get_name(trigger_key, &key_name);
+ assert(status == LTTNG_TRIGGER_STATUS_OK);
+
+ /* Compare the names. */
+ if (strcmp(name, key_name) != 0) {
+ goto end;
+ }
+
+ /* Compare the owners' UIDs. */
+ key_creds = lttng_trigger_get_credentials(trigger_key);
+ node_creds = lttng_trigger_get_credentials(trigger_ht_element->trigger);
+
+ match = lttng_credentials_is_equal_uid(key_creds, node_creds);
+
+end:
+ return match;
+}
+
+/*
+ * Hash trigger based on name and credentials only.
+ */
+static
+unsigned long hash_trigger_by_name_uid(const struct lttng_trigger *trigger)
+{
+ unsigned long hash = 0;
+ const struct lttng_credentials *trigger_creds;
+ const char *trigger_name;
+ enum lttng_trigger_status status;
+
+ status = lttng_trigger_get_name(trigger, &trigger_name);
+ if (status == LTTNG_TRIGGER_STATUS_OK) {
+ hash = hash_key_str(trigger_name, lttng_ht_seed);
+ }
+
+ trigger_creds = lttng_trigger_get_credentials(trigger);
+ hash ^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds->uid),
+ lttng_ht_seed);
+
+ return hash;
+}
+
static
unsigned long lttng_condition_buffer_usage_hash(
const struct lttng_condition *_condition)
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
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;
+ return LTTNG_OBJECT_TYPE_CHANNEL;
case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
return LTTNG_OBJECT_TYPE_SESSION;
}
}
+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. */
&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
return NULL;
}
-/* RCU read lock must be held by the caller. */
+LTTNG_HIDDEN
+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);
+ notification_client_list_get(list);
+
+ 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();
+}
+
+LTTNG_HIDDEN
+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;
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");
* 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) {
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;
}
- lttng_dynamic_buffer_reset(&client->communication.inbound.buffer);
- lttng_dynamic_buffer_reset(&client->communication.outbound.buffer);
- free(client);
+ client->communication.active = false;
+ lttng_payload_reset(&client->communication.inbound.payload);
+ lttng_payload_reset(&client->communication.outbound.payload);
+ 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);
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,
goto end;
}
- list = caa_container_of(node,
+ list = caa_container_of(node,
struct lttng_session_trigger_list,
session_triggers_ht_node);
end:
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 =
if (!session) {
ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
name, uid, gid);
+ lttng_session_trigger_list_destroy(trigger_list);
goto error;
}
trigger_list = NULL;
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);
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,
channel_state_ht_node);
cds_lfht_del(state->channel_state_ht, node);
- free(sample);
+ call_rcu(&sample->rcu_node, free_channel_state_sample_rcu);
}
/* Remove the channel from the channels_ht and free it. */
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 = LTTNG_OPTIONAL_INIT_VALUE(session_uid),
+ .gid = LTTNG_OPTIONAL_INIT_VALUE(session_gid),
+ };
rcu_read_lock();
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;
struct lttng_evaluation *evaluation = NULL;
enum lttng_condition_type condition_type;
+ enum action_executor_status executor_status;
trigger = trigger_list_element->trigger;
condition = lttng_trigger_get_const_condition(trigger);
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);
-
- if (cds_list_empty(&client_list->list)) {
- /*
- * 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);
/* Internal error */
ret = -1;
cmd_result = LTTNG_ERR_UNK;
- goto end;
+ goto put_list;
+ }
+
+ /*
+ * 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();
}
- /* 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)) {
- goto end;
+ break;
}
}
end:
* 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:
/* 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;
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;
hash_channel_key(&channel->key),
match_channel_trigger_list,
&channel->key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
+ &lookup_iter);
+ node = cds_lfht_iter_get_node(&lookup_iter);
assert(node);
trigger_list = caa_container_of(node,
struct lttng_channel_trigger_list,
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/session,
- * - The notifications will not be sent since the client's credentials
- * are checked against the channel at that moment.
- *
- * If this function returns a non-zero value, it means something is
- * fundamentally broken and the whole subsystem/thread will be torn down.
+static
+bool is_trigger_action_notify(const struct lttng_trigger *trigger)
+{
+ bool is_notify = false;
+ unsigned int i, count;
+ enum lttng_action_status action_status;
+ const struct lttng_action *action =
+ lttng_trigger_get_const_action(trigger);
+ enum lttng_action_type action_type;
+
+ assert(action);
+ action_type = lttng_action_get_type(action);
+ if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
+ is_notify = true;
+ goto end;
+ } else if (action_type != LTTNG_ACTION_TYPE_GROUP) {
+ goto end;
+ }
+
+ action_status = lttng_action_group_get_count(action, &count);
+ assert(action_status == LTTNG_ACTION_STATUS_OK);
+
+ for (i = 0; i < count; i++) {
+ const struct lttng_action *inner_action =
+ lttng_action_group_get_at_index(
+ action, i);
+
+ action_type = lttng_action_get_type(inner_action);
+ if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
+ is_notify = true;
+ goto end;
+ }
+ }
+
+end:
+ return is_notify;
+}
+
+static bool trigger_name_taken(struct notification_thread_state *state,
+ const struct lttng_trigger *trigger)
+{
+ struct cds_lfht_iter iter;
+
+ /*
+ * No duplicata is allowed in the triggers_by_name_uid_ht.
+ * The match is done against the trigger name and uid.
+ */
+ cds_lfht_lookup(state->triggers_by_name_uid_ht,
+ hash_trigger_by_name_uid(trigger),
+ match_trigger_by_name_uid,
+ trigger,
+ &iter);
+ return !!cds_lfht_iter_get_node(&iter);
+}
+
+static
+enum lttng_error_code generate_trigger_name(
+ struct notification_thread_state *state,
+ struct lttng_trigger *trigger, const char **name)
+{
+ enum lttng_error_code ret_code = LTTNG_OK;
+ bool taken = false;
+ enum lttng_trigger_status status;
+
+ do {
+ const int ret = lttng_trigger_generate_name(trigger,
+ state->trigger_id.name_offset++);
+ if (ret) {
+ /* The only reason this can fail right now. */
+ ret_code = LTTNG_ERR_NOMEM;
+ break;
+ }
+
+ status = lttng_trigger_get_name(trigger, name);
+ assert(status == LTTNG_TRIGGER_STATUS_OK);
+
+ taken = trigger_name_taken(state, trigger);
+ } while (taken || state->trigger_id.name_offset == UINT64_MAX);
+
+ return ret_code;
+}
+
+/*
+ * FIXME A client's credentials are not checked when registering a 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/session,
+ * - The notifications will not be sent since the client's credentials
+ * are checked against the channel at that moment.
+ *
+ * If this function returns a non-zero value, it means something is
+ * fundamentally broken and the whole subsystem/thread will be torn down.
*
* If a non-fatal error occurs, just set the cmd_result to the appropriate
* error code.
struct notification_client *client;
struct notification_client_list *client_list = NULL;
struct lttng_trigger_ht_element *trigger_ht_element = NULL;
- struct notification_client_list_element *client_list_element, *tmp;
+ struct notification_client_list_element *client_list_element;
struct cds_lfht_node *node;
struct cds_lfht_iter iter;
+ const char* trigger_name;
bool free_trigger = true;
+ struct lttng_evaluation *evaluation = NULL;
+ struct lttng_credentials object_creds;
+ uid_t object_uid;
+ gid_t object_gid;
+ enum action_executor_status executor_status;
+ const uint64_t trigger_tracer_token =
+ state->trigger_id.next_tracer_token++;
rcu_read_lock();
+ /* Set the trigger's tracer token. */
+ lttng_trigger_set_tracer_token(trigger, trigger_tracer_token);
+
+ if (lttng_trigger_get_name(trigger, &trigger_name) ==
+ LTTNG_TRIGGER_STATUS_UNSET) {
+ const enum lttng_error_code ret_code = generate_trigger_name(
+ state, trigger, &trigger_name);
+
+ if (ret_code != LTTNG_OK) {
+ /* Fatal error. */
+ ret = -1;
+ *cmd_result = ret_code;
+ goto error;
+ }
+ } else if (trigger_name_taken(state, trigger)) {
+ /* Not a fatal error. */
+ *cmd_result = LTTNG_ERR_TRIGGER_EXISTS;
+ ret = 0;
+ goto error;
+ }
+
condition = lttng_trigger_get_condition(trigger);
assert(condition);
/* Add trigger to the trigger_ht. */
cds_lfht_node_init(&trigger_ht_element->node);
+ cds_lfht_node_init(&trigger_ht_element->node_by_name_uid);
trigger_ht_element->trigger = trigger;
node = cds_lfht_add_unique(state->triggers_ht,
lttng_condition_hash(condition),
- match_condition,
- condition,
+ match_trigger,
+ trigger,
&trigger_ht_element->node);
if (node != &trigger_ht_element->node) {
/* Not a fatal error, simply report it to the client. */
goto error_free_ht_element;
}
+ node = cds_lfht_add_unique(state->triggers_by_name_uid_ht,
+ hash_trigger_by_name_uid(trigger),
+ match_trigger_by_name_uid,
+ trigger,
+ &trigger_ht_element->node_by_name_uid);
+ if (node != &trigger_ht_element->node_by_name_uid) {
+ /* Not a fatal error, simply report it to the client. */
+ cds_lfht_del(state->triggers_ht, &trigger_ht_element->node);
+ *cmd_result = LTTNG_ERR_TRIGGER_EXISTS;
+ goto error_free_ht_element;
+ }
+
/*
* Ownership of the trigger and of its wrapper was transfered to
* the triggers_ht.
* It is not skipped as this is the only action type currently
* supported.
*/
- client_list = zmalloc(sizeof(*client_list));
- 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_socket_ht_node) {
- if (!trigger_applies_to_client(trigger, client)) {
- continue;
+ if (is_trigger_action_notify(trigger)) {
+ client_list = notification_client_list_create(trigger);
+ if (!client_list) {
+ ret = -1;
+ goto error_free_ht_element;
}
- client_list_element = zmalloc(sizeof(*client_list_element));
- if (!client_list_element) {
- ret = -1;
- goto error_free_client_list;
+ /* Build a list of clients to which this new trigger applies. */
+ cds_lfht_for_each_entry (state->client_socket_ht, &iter, client,
+ client_socket_ht_node) {
+ if (!trigger_applies_to_client(trigger, client)) {
+ continue;
+ }
+
+ client_list_element =
+ zmalloc(sizeof(*client_list_element));
+ if (!client_list_element) {
+ ret = -1;
+ 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_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);
+ /*
+ * Client list ownership transferred to the
+ * notification_trigger_clients_ht.
+ */
+ publish_notification_client_list(state, client_list);
+ }
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:
break;
default:
- ERR("[notification-thread] Unknown object type on which to bind a newly registered trigger was encountered");
+ ERR("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;
}
/*
- * Since there is nothing preventing clients from subscribing to a
- * condition before the corresponding trigger is registered, we have
- * to evaluate this new condition right away.
+ * The new trigger's condition must be evaluated against the current
+ * state.
+ *
+ * In the case of `notify` action, nothing preventing clients from
+ * subscribing to a condition before the corresponding trigger is
+ * registered, we have to evaluate this new condition right away.
*
* At some point, we were waiting for the next "evaluation" (e.g. on
* reception of a channel sample) to evaluate this new condition, but
* 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.
*/
- 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;
- }
+ 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;
+ break;
+ case LTTNG_OBJECT_TYPE_UNKNOWN:
+ default:
+ ret = -1;
+ break;
+ }
+
+ if (ret) {
+ /* Fatal error. */
+ goto error_put_client_list;
+ }
+
+ LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid);
+ LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid);
+
+ DBG("Newly registered trigger's condition evaluated to %s",
+ evaluation ? "true" : "false");
+ if (!evaluation) {
+ /* Evaluation yielded nothing. Normal exit. */
+ ret = 0;
+ goto end;
}
/*
- * Client list ownership transferred to the
- * notification_trigger_clients_ht.
+ * Ownership of `evaluation` transferred to the action executor
+ * no matter the result.
*/
- client_list = NULL;
+ executor_status = action_executor_enqueue(state->executor, trigger,
+ evaluation, &object_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 to newly registered trigger");
+ ret = -1;
+ goto error_put_client_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 to newly registered trigger");
+ ret = 0;
+ goto end;
+ default:
+ abort();
+ }
+end:
*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);
- }
+ DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64,
+ trigger_name, trigger_tracer_token);
+
+error_put_client_list:
+ notification_client_list_put(client_list);
+
error_free_ht_element:
- free(trigger_ht_element);
+ if (trigger_ht_element) {
+ /* Delayed removal due to RCU constraint on delete. */
+ call_rcu(&trigger_ht_element->rcu_node,
+ free_lttng_trigger_ht_element_rcu);
+ }
+
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,
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_lfht_lookup(state->triggers_ht,
lttng_condition_hash(condition),
- match_condition,
- condition,
+ match_trigger,
+ trigger,
&iter);
triggers_ht_node = cds_lfht_iter_get_node(&iter);
if (!triggers_ht_node) {
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);
- free(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_by_name_uid_ht, &trigger_ht_element->node_by_name_uid);
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->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 {
+ ret = client_handle_transmission_status(
+ client, client_status, state);
+ }
+ rcu_read_unlock();
+ break;
+ }
default:
ERR("[notification-thread] Unknown internal command received");
goto error_unlock;
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)
{
{
int ret;
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.inbound.buffer, 0);
- assert(!ret);
+
+ lttng_payload_clear(&client->communication.inbound.payload);
client->communication.inbound.bytes_to_receive =
sizeof(struct lttng_notification_channel_message);
LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1);
LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1);
ret = lttng_dynamic_buffer_set_size(
- &client->communication.inbound.buffer,
+ &client->communication.inbound.payload.buffer,
client->communication.inbound.bytes_to_receive);
+
return 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);
+ lttng_payload_init(&client->communication.inbound.payload);
+ lttng_payload_init(&client->communication.outbound.payload);
client->communication.inbound.expect_creds = true;
+
ret = client_reset_inbound_state(client);
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;
+
error:
notification_client_destroy(client, state);
return ret;
}
-int handle_notification_thread_client_disconnect(
- int client_socket,
+/*
+ * RCU read-lock must be held by the caller.
+ * Client lock must _not_ 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. */
+ pthread_mutex_lock(&client->lock);
+ client->communication.active = false;
+ cds_lfht_del(state->client_socket_ht, &client->client_socket_ht_node);
+ cds_lfht_del(state->client_id_ht, &client->client_id_ht_node);
+ pthread_mutex_unlock(&client->lock);
+
+ ret = lttng_poll_del(&state->events, client->socket);
+ if (ret) {
+ ERR("[notification-thread] Failed to remove client socket %d from poll set",
+ client->socket);
+ }
+
+ /* 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);
+ ret = notification_thread_client_disconnect(client, state);
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);
+ ret = notification_thread_client_disconnect(
+ client, state);
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;
}
}
+ rcu_read_unlock();
return error_occurred ? -1 : 0;
}
static
-int client_flush_outgoing_queue(struct notification_client *client,
+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;
+ }
+
+ 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
+enum client_transmission_status client_flush_outgoing_queue(
+ struct notification_client *client)
{
ssize_t ret;
size_t to_send_count;
+ enum client_transmission_status status;
+ struct lttng_payload_view pv = lttng_payload_view_from_payload(
+ &client->communication.outbound.payload, 0, -1);
+ const int fds_to_send_count =
+ lttng_payload_view_get_fd_handle_count(&pv);
+
+ 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;
+ if (pv.buffer.size == 0) {
+ /*
+ * If both data and fds are equal to zero, we are in an invalid
+ * state.
+ */
+ assert(fds_to_send_count != 0);
+ goto send_fds;
+ }
+
+ /* Send data. */
+ to_send_count = pv.buffer.size;
DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue",
client->socket);
ret = lttcomm_send_unix_sock_non_block(client->socket,
- client->communication.outbound.buffer.data,
+ pv.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);
- memcpy(client->communication.outbound.buffer.data,
- client->communication.outbound.buffer.data +
- client->communication.outbound.buffer.size - to_send_count,
+ memmove(client->communication.outbound.payload.buffer.data,
+ pv.buffer.data +
+ pv.buffer.size - to_send_count,
to_send_count);
ret = lttng_dynamic_buffer_set_size(
- &client->communication.outbound.buffer,
+ &client->communication.outbound.payload.buffer,
to_send_count);
if (ret) {
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;
+ goto end;
} else if (ret < 0) {
- /* Generic error, disconnect the client. */
- ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)",
+ /* Generic error, disable the client's communication. */
+ 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;
- }
+ client->communication.active = false;
+ status = CLIENT_TRANSMISSION_STATUS_FAIL;
+ goto end;
} else {
- /* No error and flushed the queue completely. */
+ /*
+ * No error and flushed the queue completely.
+ *
+ * The payload buffer size is used later to
+ * check if there is notifications queued. So albeit that the
+ * direct caller knows that the transmission is complete, we
+ * need to set the buffer size to zero.
+ */
ret = lttng_dynamic_buffer_set_size(
- &client->communication.outbound.buffer, 0);
- if (ret) {
- goto error;
- }
- ret = lttng_poll_mod(&state->events, client->socket,
- CLIENT_POLL_MASK_IN);
+ &client->communication.outbound.payload.buffer, 0);
if (ret) {
goto error;
}
+ }
+
+send_fds:
+ /* No fds to send, transmission is complete. */
+ if (fds_to_send_count == 0) {
+ status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
+ goto end;
+ }
+
+ ret = lttcomm_send_payload_view_fds_unix_sock_non_block(
+ client->socket, &pv);
+ if (ret < 0) {
+ /* Generic error, disable the client's communication. */
+ ERR("[notification-thread] Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)",
+ client->socket);
+ client->communication.active = false;
+ status = CLIENT_TRANSMISSION_STATUS_FAIL;
+ goto end;
+ } else if (ret == 0) {
+ /* Nothing could be sent. */
+ status = CLIENT_TRANSMISSION_STATUS_QUEUED;
+ } else {
+ /* Fd passing is an all or nothing kind of thing. */
+ status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
+ /*
+ * The payload _fd_array count is used later to
+ * check if there is notifications queued. So although the
+ * direct caller knows that the transmission is complete, we
+ * need to clear the _fd_array for the queuing check.
+ */
+ lttng_dynamic_pointer_array_clear(
+ &client->communication.outbound.payload
+ ._fd_handles);
+ }
+
+end:
+ if (status == CLIENT_TRANSMISSION_STATUS_COMPLETE) {
+ client->communication.outbound.queued_command_reply = false;
+ client->communication.outbound.dropped_notification = false;
+ lttng_payload_clear(&client->communication.outbound.payload);
+ }
+
+ return status;
+error:
+ return CLIENT_TRANSMISSION_STATUS_ERROR;
+}
+
+static
+bool client_has_outbound_data_left(
+ const struct notification_client *client)
+{
+ const struct lttng_payload_view pv = lttng_payload_view_from_payload(
+ &client->communication.outbound.payload, 0, -1);
+ const bool has_data = pv.buffer.size != 0;
+ const bool has_fds = lttng_payload_view_get_fd_handle_count(&pv);
+
+ return has_data || has_fds;
+}
+
+/* Client lock must _not_ be held by the caller. */
+static
+int client_send_command_reply(struct notification_client *client,
+ struct notification_thread_state *state,
+ enum lttng_notification_channel_status status)
+{
+ int ret;
+ struct lttng_notification_channel_command_reply reply = {
+ .status = (int8_t) status,
+ };
+ struct lttng_notification_channel_message msg = {
+ .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY,
+ .size = sizeof(reply),
+ };
+ char buffer[sizeof(msg) + sizeof(reply)];
+ enum client_transmission_status transmission_status;
+
+ memcpy(buffer, &msg, sizeof(msg));
+ memcpy(buffer + sizeof(msg), &reply, sizeof(reply));
+ DBG("[notification-thread] Send command reply (%i)", (int) status);
+
+ pthread_mutex_lock(&client->lock);
+ if (client->communication.outbound.queued_command_reply) {
+ /* Protocol error. */
+ goto error_unlock;
+ }
+
+ /* Enqueue buffer to outgoing queue and flush it. */
+ ret = lttng_dynamic_buffer_append(
+ &client->communication.outbound.payload.buffer,
+ buffer, sizeof(buffer));
+ if (ret) {
+ goto error_unlock;
+ }
+
+ transmission_status = client_flush_outgoing_queue(client);
+
+ if (client_has_outbound_data_left(client)) {
+ /* Queue could not be emptied. */
+ client->communication.outbound.queued_command_reply = true;
+ }
+
+ pthread_mutex_unlock(&client->lock);
+ ret = client_handle_transmission_status(
+ client, transmission_status, state);
+ if (ret) {
+ goto error;
+ }
+
+ return 0;
+error_unlock:
+ pthread_mutex_unlock(&client->lock);
+error:
+ return -1;
+}
+
+static
+int client_handle_message_unknown(struct notification_client *client,
+ struct notification_thread_state *state)
+{
+ int ret;
+ /*
+ * 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.payload.buffer.size);
+ msg = (const struct lttng_notification_channel_message *)
+ client->communication.inbound.payload.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.fds_to_receive = msg->fds;
+ client->communication.inbound.msg_type =
+ (enum lttng_notification_channel_message_type) msg->type;
+ ret = lttng_dynamic_buffer_set_size(
+ &client->communication.inbound.payload.buffer, msg->size);
+
+ /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */
+ msg = NULL;
+end:
+ 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)];
+
+ 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.payload.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->communication.outbound.queued_command_reply = false;
- client->communication.outbound.dropped_notification = false;
+ 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;
}
- return 0;
-error:
- return -1;
+ pthread_mutex_lock(&client->lock);
+ /* Outgoing queue will be flushed when the command reply is sent. */
+ ret = lttng_dynamic_buffer_append(
+ &client->communication.outbound.payload.buffer, send_buffer,
+ sizeof(send_buffer));
+ if (ret) {
+ ERR("[notification-thread] Failed to send protocol version to notification channel client");
+ goto end_unlock;
+ }
+
+ client->validated = true;
+ client->communication.active = true;
+ pthread_mutex_unlock(&client->lock);
+
+ /* 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;
+ }
+
+ /* Flushes the outgoing queue. */
+ ret = client_send_command_reply(client, state, status);
+ if (ret) {
+ ERR("[notification-thread] Failed to send reply to notification channel client");
+ goto end;
+ }
+
+ goto end;
+end_unlock:
+ pthread_mutex_unlock(&client->lock);
+end:
+ return ret;
}
static
-int client_send_command_reply(struct notification_client *client,
- struct notification_thread_state *state,
- enum lttng_notification_channel_status status)
+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_notification_channel_command_reply reply = {
- .status = (int8_t) status,
- };
- struct lttng_notification_channel_message msg = {
- .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY,
- .size = sizeof(reply),
- };
- char buffer[sizeof(msg) + sizeof(reply)];
+ 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_payload(
+ &client->communication.inbound.payload,
+ 0, -1);
+ size_t expected_condition_size;
- if (client->communication.outbound.queued_command_reply) {
- /* Protocol error. */
- goto error;
+ /*
+ * No need to lock client to sample the inbound state as the only
+ * other thread accessing clients (action executor) only uses the
+ * outbound state.
+ */
+ expected_condition_size = client->communication.inbound.payload.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;
}
- memcpy(buffer, &msg, sizeof(msg));
- memcpy(buffer + sizeof(msg), &reply, sizeof(reply));
- DBG("[notification-thread] Send command reply (%i)", (int) status);
+ 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);
+ }
- /* Enqueue buffer to outgoing queue and flush it. */
- ret = lttng_dynamic_buffer_append(
- &client->communication.outbound.buffer,
- buffer, sizeof(buffer));
if (ret) {
- goto error;
+ goto end;
}
- ret = client_flush_outgoing_queue(client, state);
+ /* Set reception state to receive the next message header. */
+ ret = client_reset_inbound_state(client);
if (ret) {
- goto error;
+ ERR("[notification-thread] Failed to reset client communication's inbound state");
+ goto end;
}
- if (client->communication.outbound.buffer.size != 0) {
- /* Queue could not be emptied. */
- client->communication.outbound.queued_command_reply = true;
+ ret = client_send_command_reply(client, state, status);
+ if (ret) {
+ ERR("[notification-thread] Failed to send reply to notification channel client");
+ goto end;
}
- return 0;
-error:
- return -1;
+end:
+ return ret;
}
static
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:
ssize_t recv_ret;
size_t offset;
+ rcu_read_lock();
client = get_client_from_socket(socket, state);
if (!client) {
/* Internal error, abort. */
goto end;
}
- offset = client->communication.inbound.buffer.size -
+ offset = client->communication.inbound.payload.buffer.size -
client->communication.inbound.bytes_to_receive;
if (client->communication.inbound.expect_creds) {
recv_ret = lttcomm_recv_creds_unix_sock(socket,
- client->communication.inbound.buffer.data + offset,
+ client->communication.inbound.payload.buffer.data + offset,
client->communication.inbound.bytes_to_receive,
&client->communication.inbound.creds);
if (recv_ret > 0) {
}
} else {
recv_ret = lttcomm_recv_unix_sock_non_block(socket,
- client->communication.inbound.buffer.data + offset,
+ client->communication.inbound.payload.buffer.data + offset,
client->communication.inbound.bytes_to_receive);
}
- if (recv_ret < 0) {
+ if (recv_ret >= 0) {
+ client->communication.inbound.bytes_to_receive -= recv_ret;
+ } else {
goto error_disconnect_client;
}
- client->communication.inbound.bytes_to_receive -= recv_ret;
- if (client->communication.inbound.bytes_to_receive == 0) {
- ret = client_dispatch_message(client, state);
- if (ret) {
+ if (client->communication.inbound.bytes_to_receive != 0) {
+ /* Message incomplete wait for more data. */
+ ret = 0;
+ goto end;
+ }
+
+ assert(client->communication.inbound.bytes_to_receive == 0);
+
+ /* Receive fds. */
+ if (client->communication.inbound.fds_to_receive != 0) {
+ ret = lttcomm_recv_payload_fds_unix_sock_non_block(
+ client->socket,
+ client->communication.inbound.fds_to_receive,
+ &client->communication.inbound.payload);
+ if (ret > 0) {
/*
- * Only returns an error if this client must be
- * disconnected.
+ * Fds received. non blocking fds passing is all
+ * or nothing.
*/
+ ssize_t expected_size;
+
+ expected_size = sizeof(int) *
+ client->communication.inbound
+ .fds_to_receive;
+ assert(ret == expected_size);
+ client->communication.inbound.fds_to_receive = 0;
+ } else if (ret == 0) {
+ /* Received nothing. */
+ ret = 0;
+ goto end;
+ } else {
goto error_disconnect_client;
}
- } else {
- goto end;
}
+
+ /* At this point the message is complete.*/
+ assert(client->communication.inbound.bytes_to_receive == 0 &&
+ client->communication.inbound.fds_to_receive == 0);
+ ret = client_dispatch_message(client, state);
+ if (ret) {
+ /*
+ * Only returns an error if this client must be
+ * disconnected.
+ */
+ goto error_disconnect_client;
+ }
+
end:
+ rcu_read_unlock();
return ret;
+
error_disconnect_client:
- ret = handle_notification_thread_client_disconnect(socket, state);
- return ret;
+ ret = notification_thread_client_disconnect(client, state);
+ goto end;
}
/* Client ready to receive outgoing data. */
{
int ret;
struct notification_client *client;
+ enum client_transmission_status transmission_status;
+ rcu_read_lock();
client = get_client_from_socket(socket, state);
if (!client) {
/* Internal error, abort. */
goto end;
}
- ret = client_flush_outgoing_queue(client, state);
+ pthread_mutex_lock(&client->lock);
+ transmission_status = client_flush_outgoing_queue(client);
+ pthread_mutex_unlock(&client->lock);
+
+ ret = client_handle_transmission_status(
+ client, transmission_status, state);
if (ret) {
goto end;
}
end:
+ rcu_read_unlock();
return ret;
}
* 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 client_enqueue_dropped_notification(struct notification_client *client,
- struct notification_thread_state *state)
+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,
+ &client->communication.outbound.payload.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 channel_uid, gid_t channel_gid)
+ uid_t object_uid, gid_t object_gid)
+{
+ const struct lttng_credentials creds = {
+ .uid = LTTNG_OPTIONAL_INIT_VALUE(object_uid),
+ .gid = LTTNG_OPTIONAL_INIT_VALUE(object_gid),
+ };
+
+ return notification_client_list_send_evaluation(client_list,
+ lttng_trigger_get_const_condition(trigger), evaluation,
+ lttng_trigger_get_credentials(trigger),
+ &creds,
+ 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
+ * 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).
+ */
+LTTNG_HIDDEN
+int notification_client_list_send_evaluation(
+ struct notification_client_list *client_list,
+ const struct lttng_condition *condition,
+ const struct lttng_evaluation *evaluation,
+ 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_dynamic_buffer msg_buffer;
+ 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,
};
- lttng_dynamic_buffer_init(&msg_buffer);
+ lttng_payload_init(&msg_payload);
- ret = lttng_dynamic_buffer_append(&msg_buffer, &msg_header,
+ ret = lttng_dynamic_buffer_append(&msg_payload.buffer, &msg_header,
sizeof(msg_header));
if (ret) {
goto end;
}
- ret = lttng_notification_serialize(¬ification, &msg_buffer);
+ ret = lttng_notification_serialize(¬ification, &msg_payload);
if (ret) {
ERR("[notification-thread] Failed to serialize notification");
ret = -1;
}
/* Update payload size. */
- ((struct lttng_notification_channel_message * ) msg_buffer.data)->size =
- (uint32_t) (msg_buffer.size - sizeof(msg_header));
+ ((struct lttng_notification_channel_message *) msg_payload.buffer.data)
+ ->size = (uint32_t)(
+ msg_payload.buffer.size - sizeof(msg_header));
+
+ /* Update the payload number of fds. */
+ {
+ const struct lttng_payload_view pv = lttng_payload_view_from_payload(
+ &msg_payload, 0, -1);
+
+ ((struct lttng_notification_channel_message *)
+ msg_payload.buffer.data)->fds = (uint32_t)
+ lttng_payload_view_get_fd_handle_count(&pv);
+ }
+ 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;
- if (client->uid != channel_uid && client->gid != channel_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;
+ ret = 0;
+ pthread_mutex_lock(&client->lock);
+ if (!client->communication.active) {
+ /*
+ * Skip inactive client (protocol error or
+ * disconnecting).
+ */
+ DBG("Skipping client at it is marked as inactive");
+ goto skip_client;
+ }
+
+ if (source_object_creds) {
+ if (client->uid != lttng_credentials_get_uid(source_object_creds) &&
+ client->gid != lttng_credentials_get_gid(source_object_creds) &&
+ 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 skip_client;
+ }
+ }
+
+ if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) {
+ DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger");
+ goto skip_client;
}
DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)",
- client->socket, msg_buffer.size);
- if (client->communication.outbound.buffer.size) {
+ client->socket, msg_payload.buffer.size);
+
+ if (client_has_outbound_data_left(client)) {
/*
* Outgoing data is already buffered for this client;
* drop the notification and enqueue a "dropped
* 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, state);
- if (ret) {
- goto end;
- }
+ ret = client_notification_overflow(client);
+ if (ret) {
+ /* Fatal error. */
+ goto skip_client;
}
- continue;
}
- ret = lttng_dynamic_buffer_append_buffer(
- &client->communication.outbound.buffer,
- &msg_buffer);
+ ret = lttng_payload_copy(&msg_payload, &client->communication.outbound.payload);
if (ret) {
- goto end;
+ /* Fatal error. */
+ goto skip_client;
}
- ret = client_flush_outgoing_queue(client, state);
+ transmission_status = client_flush_outgoing_queue(client);
+ pthread_mutex_unlock(&client->lock);
+ ret = client_report(client, transmission_status, user_data);
if (ret) {
- goto end;
+ /* Fatal error. */
+ goto end_unlock_list;
+ }
+
+ continue;
+
+skip_client:
+ pthread_mutex_unlock(&client->lock);
+ if (ret) {
+ /* Fatal error. */
+ goto end_unlock_list;
}
}
ret = 0;
+
+end_unlock_list:
+ pthread_mutex_unlock(&client_list->lock);
end:
- lttng_dynamic_buffer_reset(&msg_buffer);
+ lttng_payload_reset(&msg_payload);
return ret;
}
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 = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->uid),
+ .gid = LTTNG_OPTIONAL_INIT_VALUE(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) {
+ node) {
const struct lttng_condition *condition;
- const struct lttng_action *action;
- const struct lttng_trigger *trigger;
- struct notification_client_list *client_list;
+ struct lttng_trigger *trigger;
+ struct notification_client_list *client_list = NULL;
struct lttng_evaluation *evaluation = NULL;
+ enum action_executor_status executor_status;
+ ret = 0;
trigger = trigger_list_element->trigger;
condition = lttng_trigger_get_const_condition(trigger);
assert(condition);
- 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);
/*
* Check if any client is subscribed to the result of this
* evaluation.
*/
client_list = get_client_list_from_condition(state, condition);
- assert(client_list);
- if (cds_list_empty(&client_list->list)) {
- /*
- * No clients interested in the evaluation's result,
- * skip it.
- */
- continue;
- }
ret = evaluate_buffer_condition(condition, &evaluation, state,
previous_sample_available ? &previous_sample : NULL,
latest_session_consumed_total,
channel_info);
if (caa_unlikely(ret)) {
- goto end_unlock;
+ goto put_list;
}
if (caa_likely(!evaluation)) {
- continue;
+ goto put_list;
+ }
+
+ if (!lttng_trigger_should_fire(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);
+ lttng_trigger_fire(trigger);
+
+ /*
+ * 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)) {
- goto end_unlock;
+ break;
}
}
end_unlock:
projects / lttng-tools.git / blobdiff