X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;fp=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;h=e3c35f3a5e9e4f7cbbabfe48b923ed0556a05b9d;hp=73ec72f89c308b86ce2c95da5c364738d5b42680;hb=1831ae68b70dece8e9b847081526495adbbf05e5;hpb=25357057de5ae4dd2a572e8f9b893c1b90cbd60a diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c index 73ec72f89..e3c35f3a5 100644 --- a/src/bin/lttng-sessiond/notification-thread-events.c +++ b/src/bin/lttng-sessiond/notification-thread-events.c @@ -19,12 +19,15 @@ #include #include #include +#include #include #include #include #include #include +#include #include +#include #include #include @@ -50,7 +53,7 @@ enum lttng_object_type { 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; }; @@ -108,6 +111,7 @@ struct lttng_session_trigger_list { struct lttng_trigger_ht_element { struct lttng_trigger *trigger; struct cds_lfht_node node; + struct cds_lfht_node node_by_name; /* call_rcu delayed reclaim. */ struct rcu_head rcu_node; }; @@ -117,85 +121,17 @@ 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; - /* call_rcu delayed reclaim. */ - struct rcu_head rcu_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; - /* call_rcu delayed reclaim. */ - struct rcu_head rcu_node; +/* + * Facilities to carry the different notifications type in the action processing + * code path. + */ +struct lttng_trigger_notification { + union { + struct lttng_ust_trigger_notification *ust; + uint64_t *kernel; + } u; + uint64_t id; + enum lttng_domain_type type; }; struct channel_state_sample { @@ -258,20 +194,29 @@ void lttng_session_trigger_list_destroy( struct lttng_session_trigger_list *list); static int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, - const struct lttng_trigger *trigger); + struct lttng_trigger *trigger); static -int match_client(struct cds_lfht_node *node, const void *key) +int match_client_socket(struct cds_lfht_node *node, const void *key) { /* This double-cast is intended to supress pointer-to-cast warning. */ - int socket = (int) (intptr_t) key; - struct notification_client *client; + const int socket = (int) (intptr_t) key; + const struct notification_client *client = caa_container_of(node, + struct notification_client, client_socket_ht_node); - client = caa_container_of(node, struct notification_client, - client_socket_ht_node); + return client->socket == socket; +} - 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->id == id; } static @@ -326,18 +271,42 @@ int match_channel_info(struct cds_lfht_node *node, const void *key) } 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; + bool match = false; + struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; + struct lttng_trigger_ht_element *trigger_ht_element; + const struct lttng_credentials *creds_key; + const struct lttng_credentials *creds_node; - 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); + match = lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger); + if (!match) { + goto end; + } + + /* Validate credential */ + /* TODO: this could be moved to lttng_trigger_equal depending on how we + * handle root behaviour on disable and listing. + */ + creds_key = lttng_trigger_get_credentials(trigger_key); + creds_node = lttng_trigger_get_credentials(trigger_ht_element->trigger); + match = lttng_credentials_is_equal(creds_key, creds_node); +end: + return !!match; +} + +static +int match_trigger_token(struct cds_lfht_node *node, const void *key) +{ + const uint64_t *_key = key; + struct notification_trigger_tokens_ht_element *element; + + element = caa_container_of(node, struct notification_trigger_tokens_ht_element, + node); + return *_key == element->token ; } static @@ -350,7 +319,7 @@ int match_client_list_condition(struct cds_lfht_node *node, const void *key) 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); @@ -366,6 +335,23 @@ int match_session(struct cds_lfht_node *node, const void *key) return !strcmp(session_info->name, name); } +/* + * Match function for string node. + */ +static int match_str(struct cds_lfht_node *node, const void *key) +{ + struct lttng_trigger_ht_element *trigger_ht_element; + const char *name; + + trigger_ht_element = caa_container_of(node, struct lttng_trigger_ht_element, + node_by_name); + + /* TODO error checking */ + lttng_trigger_get_name(trigger_ht_element->trigger, &name); + + return hash_match_key_str(name, (void *) key); +} + static unsigned long lttng_condition_buffer_usage_hash( const struct lttng_condition *_condition) @@ -442,6 +428,22 @@ unsigned long lttng_condition_session_rotation_hash( return hash; } +static +unsigned long lttng_condition_event_rule_hash( + const struct lttng_condition *_condition) +{ + unsigned long hash, condition_type; + struct lttng_condition_event_rule *condition; + + condition = container_of(_condition, + struct lttng_condition_event_rule, parent); + condition_type = (unsigned long) condition->parent.type; + hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); + + /* TODO: further hasg using the event rule? on pattern maybe?*/ + return hash; +} + /* * The lttng_condition hashing code is kept in this file (rather than * condition.c) since it makes use of GPLv2 code (hashtable utils), which we @@ -459,6 +461,8 @@ unsigned long lttng_condition_hash(const struct lttng_condition *condition) case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: return lttng_condition_session_rotation_hash(condition); + case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT: + return lttng_condition_event_rule_hash(condition); default: ERR("[notification-thread] Unexpected condition type caught"); abort(); @@ -475,6 +479,18 @@ unsigned long hash_channel_key(struct channel_key *key) 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 @@ -495,6 +511,8 @@ enum lttng_object_type get_condition_binding_object( case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: return LTTNG_OBJECT_TYPE_SESSION; + case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT: + return LTTNG_OBJECT_TYPE_NONE; default: return LTTNG_OBJECT_TYPE_UNKNOWN; } @@ -666,7 +684,90 @@ error: 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); + + 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, @@ -674,20 +775,24 @@ struct notification_client_list *get_client_list_from_condition( { struct cds_lfht_node *node; struct cds_lfht_iter iter; + struct notification_client_list *list = NULL; + rcu_read_lock(); cds_lfht_lookup(state->notification_trigger_clients_ht, lttng_condition_hash(condition), match_client_list_condition, condition, &iter); node = cds_lfht_iter_get_node(&iter); - - return node ? caa_container_of(node, - struct notification_client_list, - notification_trigger_ht_node) : NULL; + if (node) { + list = container_of(node, struct notification_client_list, + notification_trigger_clients_ht_node); + list = notification_client_list_get(list) ? list : NULL; + } + rcu_read_unlock(); + return list; } -/* This function must be called with the RCU read lock held. */ static int evaluate_channel_condition_for_client( const struct lttng_condition *condition, @@ -703,6 +808,8 @@ int evaluate_channel_condition_for_client( 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) { @@ -777,6 +884,7 @@ int evaluate_channel_condition_for_client( *session_uid = channel_info->session_info->uid; *session_gid = channel_info->session_info->gid; end: + rcu_read_unlock(); return ret; } @@ -812,7 +920,6 @@ end: 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, @@ -826,6 +933,7 @@ int evaluate_session_condition_for_client( 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. */ @@ -879,10 +987,10 @@ int evaluate_session_condition_for_client( 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, @@ -891,7 +999,9 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, { 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; @@ -911,6 +1021,7 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, &evaluation, &object_uid, &object_gid); break; case LTTNG_OBJECT_TYPE_NONE: + DBG("[notification-thread] Newly subscribed-to condition not binded to object, nothing to evaluate"); ret = 0; goto end; case LTTNG_OBJECT_TYPE_UNKNOWN: @@ -933,7 +1044,7 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, * 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; @@ -957,7 +1068,7 @@ int notification_thread_client_subscribe(struct notification_client *client, 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 = @@ -986,8 +1097,6 @@ int notification_thread_client_subscribe(struct notification_client *client, goto error; } - rcu_read_lock(); - /* * Add the newly-subscribed condition to the client's subscription list. */ @@ -1003,20 +1112,24 @@ int notification_thread_client_subscribe(struct notification_client *client, * 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; } /* @@ -1026,13 +1139,17 @@ int notification_thread_client_subscribe(struct notification_client *client, */ 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); @@ -1088,23 +1205,24 @@ int notification_thread_client_unsubscribe( * 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) { @@ -1123,24 +1241,22 @@ static void notification_client_destroy(struct notification_client *client, struct notification_thread_state *state) { - struct lttng_condition_list_element *condition_list_element, *tmp; - if (!client) { return; } - /* Release all conditions to which the client was subscribed. */ - cds_list_for_each_entry_safe(condition_list_element, tmp, - &client->condition_list, node) { - (void) notification_thread_client_unsubscribe(client, - condition_list_element->condition, state, NULL); - } - + /* + * The client object is not reachable by other threads, no need to lock + * the client here. + */ if (client->socket >= 0) { (void) lttcomm_close_unix_sock(client->socket); + client->socket = -1; } + client->communication.active = false; lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); + pthread_mutex_destroy(&client->lock); call_rcu(&client->rcu_node, free_notification_client_rcu); } @@ -1157,8 +1273,8 @@ struct notification_client *get_client_from_socket(int socket, 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); @@ -1172,6 +1288,34 @@ end: 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, @@ -1375,7 +1519,7 @@ void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list *list) static int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, - const struct lttng_trigger *trigger) + struct lttng_trigger *trigger) { int ret = 0; struct lttng_trigger_list_element *new_element = @@ -1762,6 +1906,7 @@ int handle_notification_thread_command_session_rotation( struct notification_client_list *client_list; struct lttng_evaluation *evaluation = NULL; enum lttng_condition_type condition_type; + bool client_list_is_empty; trigger = trigger_list_element->trigger; condition = lttng_trigger_get_const_condition(trigger); @@ -1785,7 +1930,10 @@ int handle_notification_thread_command_session_rotation( client_list = get_client_list_from_condition(state, condition); assert(client_list); - if (cds_list_empty(&client_list->list)) { + pthread_mutex_lock(&client_list->lock); + client_list_is_empty = cds_list_empty(&client_list->list); + pthread_mutex_unlock(&client_list->lock); + if (client_list_is_empty) { /* * No clients interested in the evaluation's result, * skip it. @@ -1805,7 +1953,7 @@ int handle_notification_thread_command_session_rotation( /* Internal error */ ret = -1; cmd_result = LTTNG_ERR_UNK; - goto end; + goto put_list; } /* Dispatch evaluation result to all clients. */ @@ -1814,8 +1962,10 @@ int handle_notification_thread_command_session_rotation( 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: @@ -1826,59 +1976,294 @@ end: } static -int condition_is_supported(struct lttng_condition *condition) +int handle_notification_thread_command_add_application( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + int read_side_trigger_event_application_pipe, + enum lttng_error_code *_cmd_result) { - int ret; + int ret = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_trigger_source_element *element = NULL; - switch (lttng_condition_get_type(condition)) { - case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: - case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: - { - enum lttng_domain_type domain; + element = zmalloc(sizeof(*element)); + if (!element) { + cmd_result = LTTNG_ERR_NOMEM; + ret = -1; + goto end; + } - ret = lttng_condition_buffer_usage_get_domain_type(condition, - &domain); - if (ret) { - ret = -1; - goto end; - } + CDS_INIT_LIST_HEAD(&element->node); + element->fd = read_side_trigger_event_application_pipe; - if (domain != LTTNG_DOMAIN_KERNEL) { - ret = 1; - goto end; - } + pthread_mutex_lock(&handle->event_trigger_sources.lock); + cds_list_add(&element->node, &handle->event_trigger_sources.list); + pthread_mutex_unlock(&handle->event_trigger_sources.lock); - /* - * Older kernel tracers don't expose the API to monitor their - * buffers. Therefore, we reject triggers that require that - * mechanism to be available to be evaluated. - */ - ret = kernel_supports_ring_buffer_snapshot_sample_positions(); - break; - } - default: - ret = 1; + /* TODO: remove on failure to add to list? */ + + /* Adding the read side pipe to the event poll */ + ret = lttng_poll_add(&state->events, + read_side_trigger_event_application_pipe, + LPOLLIN | LPOLLERR); + + DBG3("[notification-thread] Adding application event source from fd: %d", read_side_trigger_event_application_pipe); + if (ret < 0) { + /* TODO: what should be the value of cmd_result??? */ + ERR("[notification-thread] Failed to add event source pipe fd to pollset"); + goto end; } + end: + *_cmd_result = cmd_result; return ret; } -/* Must be called with RCU read lock held. */ static -int bind_trigger_to_matching_session(const struct lttng_trigger *trigger, - struct notification_thread_state *state) +int handle_notification_thread_command_remove_application( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + int read_side_trigger_event_application_pipe, + enum lttng_error_code *_cmd_result) { int ret = 0; - const struct lttng_condition *condition; - const char *session_name; - struct lttng_session_trigger_list *trigger_list; + enum lttng_error_code cmd_result = LTTNG_OK; - condition = lttng_trigger_get_const_condition(trigger); - switch (lttng_condition_get_type(condition)) { - case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: - case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: - { - enum lttng_condition_status status; + /* TODO: missing a lock propably to revisit */ + struct notification_event_trigger_source_element *source_element, *tmp; + cds_list_for_each_entry_safe(source_element, tmp, + &handle->event_trigger_sources.list, node) { + if (source_element->fd != read_side_trigger_event_application_pipe) { + continue; + } + + DBG("[notification-thread] Removed event source from event source list"); + cds_list_del(&source_element->node); + break; + } + + DBG3("[notification-thread] Removing application event source from fd: %d", read_side_trigger_event_application_pipe); + /* Removing the read side pipe to the event poll */ + ret = lttng_poll_del(&state->events, + read_side_trigger_event_application_pipe); + if (ret < 0) { + /* TODO: what should be the value of cmd_result??? */ + ERR("[notification-thread] Failed to remove event source pipe fd from pollset"); + goto end; + } + +end: + *_cmd_result = cmd_result; + return ret; +} + +static int handle_notification_thread_command_get_tokens( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + struct lttng_triggers **triggers, + enum lttng_error_code *_cmd_result) +{ + int ret = 0, i = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct cds_lfht_iter iter; + struct notification_trigger_tokens_ht_element *element; + struct lttng_triggers *local_triggers = NULL; + + local_triggers = lttng_triggers_create(); + if (!local_triggers) { + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + + rcu_read_lock(); + cds_lfht_for_each_entry ( + state->trigger_tokens_ht, &iter, element, node) { + ret = lttng_triggers_add(local_triggers, element->trigger); + if (ret < 0) { + cmd_result = LTTNG_ERR_FATAL; + ret = -1; + goto end; + } + + /* Ownership is shared with the lttng_triggers object */ + lttng_trigger_get(element->trigger); + + i++; + } + + /* Passing ownership up */ + *triggers = local_triggers; + local_triggers = NULL; + +end: + rcu_read_unlock(); + lttng_triggers_destroy(local_triggers); + *_cmd_result = cmd_result; + return ret; +} + +static +int handle_notification_thread_command_list_triggers( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + uid_t uid, + gid_t gid, + struct lttng_triggers **triggers, + enum lttng_error_code *_cmd_result) +{ + int ret = 0, i = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct cds_lfht_iter iter; + struct lttng_trigger_ht_element *trigger_ht_element; + struct lttng_triggers *local_triggers = NULL; + const struct lttng_credentials *creds; + + long scb, sca; + unsigned long count; + + rcu_read_lock(); + cds_lfht_count_nodes(state->triggers_ht, &scb, &count, &sca); + + /* TODO check downcasting */ + local_triggers = lttng_triggers_create(); + if (!local_triggers) { + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + + cds_lfht_for_each_entry (state->triggers_ht, &iter, + trigger_ht_element, node) { + /* Only return the trigger for which the requestion client have + * access. For now the root user can only list its own + * triggers. + * TODO: root user behavior + */ + creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); + if ((uid != creds->uid) || (gid != creds->gid)) { + continue; + } + + ret = lttng_triggers_add(local_triggers, trigger_ht_element->trigger); + if (ret < 0) { + ret = -1; + goto end; + } + /* Ownership is shared with the lttng_triggers object */ + lttng_trigger_get(trigger_ht_element->trigger); + + i++; + } + + /* Passing ownership up */ + *triggers = local_triggers; + local_triggers = NULL; + +end: + rcu_read_unlock(); + lttng_triggers_destroy(local_triggers); + *_cmd_result = cmd_result; + return ret; +} + +static +int condition_is_supported(struct lttng_condition *condition) +{ + int ret; + + switch (lttng_condition_get_type(condition)) { + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: + { + enum lttng_domain_type domain; + + ret = lttng_condition_buffer_usage_get_domain_type(condition, + &domain); + if (ret) { + ret = -1; + goto end; + } + + if (domain != LTTNG_DOMAIN_KERNEL) { + ret = 1; + goto end; + } + + /* + * Older kernel tracers don't expose the API to monitor their + * buffers. Therefore, we reject triggers that require that + * mechanism to be available to be evaluated. + */ + ret = kernel_supports_ring_buffer_snapshot_sample_positions(); + break; + } + case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT: + { + /* TODO: + * Check for kernel support. + * Check for ust support ?? + */ + ret = 1; + break; + } + default: + ret = 1; + } +end: + return ret; +} + +static +int action_is_supported(struct lttng_action *action) +{ + int ret; + + switch (lttng_action_get_type(action)) { + case LTTNG_ACTION_TYPE_NOTIFY: + case LTTNG_ACTION_TYPE_START_SESSION: + case LTTNG_ACTION_TYPE_STOP_SESSION: + case LTTNG_ACTION_TYPE_ROTATE_SESSION: + case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION: + { + /* TODO validate that this is true for kernel in regards to + * rotation and snapshot. Start stop is not a problem notify + * either. + */ + /* For now all type of actions are supported */ + ret = 1; + break; + } + case LTTNG_ACTION_TYPE_GROUP: + { + /* TODO: Iterate over all internal actions and validate that + * they are supported + */ + ret = 1; + break; + + } + default: + ret = 1; + } + + return ret; +} + +/* Must be called with RCU read lock held. */ +static +int bind_trigger_to_matching_session(struct lttng_trigger *trigger, + struct notification_thread_state *state) +{ + int ret = 0; + const struct lttng_condition *condition; + const char *session_name; + struct lttng_session_trigger_list *trigger_list; + + condition = lttng_trigger_get_const_condition(trigger); + switch (lttng_condition_get_type(condition)) { + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: + { + enum lttng_condition_status status; status = lttng_condition_session_rotation_get_session_name( condition, &session_name); @@ -1911,7 +2296,7 @@ end: /* 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; @@ -1955,95 +2340,26 @@ end: return ret; } -/* - * FIXME A client's credentials are not checked when registering a trigger, nor - * are they stored alongside with the trigger. - * - * The effects of this are benign since: - * - The client will succeed in registering the trigger, as it is valid, - * - The trigger will, internally, be bound to the channel/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. - */ -static -int handle_notification_thread_command_register_trigger( +static int action_notify_register_trigger( struct notification_thread_state *state, - struct lttng_trigger *trigger, - enum lttng_error_code *cmd_result) + struct lttng_trigger *trigger) { + int ret = 0; struct lttng_condition *condition; 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 cds_lfht_node *node; struct cds_lfht_iter iter; - bool free_trigger = true; - - rcu_read_lock(); + struct notification_client_list_element *client_list_element, *tmp; condition = lttng_trigger_get_condition(trigger); assert(condition); - ret = condition_is_supported(condition); - if (ret < 0) { - goto error; - } else if (ret == 0) { - *cmd_result = LTTNG_ERR_NOT_SUPPORTED; - goto error; - } else { - /* Feature is supported, continue. */ - ret = 0; - } - - trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); - if (!trigger_ht_element) { - ret = -1; - goto error; - } - - /* Add trigger to the trigger_ht. */ - cds_lfht_node_init(&trigger_ht_element->node); - trigger_ht_element->trigger = trigger; - - node = cds_lfht_add_unique(state->triggers_ht, - lttng_condition_hash(condition), - match_condition, - condition, - &trigger_ht_element->node); - if (node != &trigger_ht_element->node) { - /* Not a fatal error, simply report it to the client. */ - *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. - */ - trigger_ht_element = NULL; - free_trigger = false; - - /* - * The rest only applies to triggers that have a "notify" action. - * It is not skipped as this is the only action type currently - * supported. - */ - client_list = zmalloc(sizeof(*client_list)); + client_list = notification_client_list_create(trigger); if (!client_list) { ret = -1; - goto error_free_ht_element; + goto end; } - 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, @@ -2055,23 +2371,19 @@ int handle_notification_thread_command_register_trigger( client_list_element = zmalloc(sizeof(*client_list_element)); if (!client_list_element) { ret = -1; - goto error_free_client_list; + goto error_put_client_list; } CDS_INIT_LIST_HEAD(&client_list_element->node); client_list_element->client = client; cds_list_add(&client_list_element->node, &client_list->list); } - cds_lfht_add(state->notification_trigger_clients_ht, - lttng_condition_hash(condition), - &client_list->notification_trigger_ht_node); - switch (get_condition_binding_object(condition)) { case LTTNG_OBJECT_TYPE_SESSION: /* Add the trigger to the list if it matches a known session. */ ret = bind_trigger_to_matching_session(trigger, state); if (ret) { - goto error_free_client_list; + goto error_put_client_list; } break; case LTTNG_OBJECT_TYPE_CHANNEL: @@ -2081,7 +2393,7 @@ int handle_notification_thread_command_register_trigger( */ 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: @@ -2089,7 +2401,7 @@ int handle_notification_thread_command_register_trigger( default: ERR("[notification-thread] Unknown object type on which to bind a newly registered trigger was encountered"); ret = -1; - goto error_free_client_list; + goto error_put_client_list; } /* @@ -2117,13 +2429,15 @@ int handle_notification_thread_command_register_trigger( * current state. Otherwise, the next evaluation cycle may only see * that the evaluations remain the same (true for samples n-1 and n) and * the client will never know that the condition has been met. + * + * No need to lock the list here as it has not been published yet. */ cds_list_for_each_entry_safe(client_list_element, tmp, &client_list->list, node) { ret = evaluate_condition_for_client(trigger, condition, client_list_element->client, state); if (ret) { - goto error_free_client_list; + goto error_put_client_list; } } @@ -2131,25 +2445,252 @@ int handle_notification_thread_command_register_trigger( * Client list ownership transferred to the * notification_trigger_clients_ht. */ + publish_notification_client_list(state, client_list); client_list = NULL; +error_put_client_list: + notification_client_list_put(client_list); +end: + return ret; +} - *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); +static +bool trigger_name_taken(struct notification_thread_state *state, const char *name) +{ + struct cds_lfht_node *triggers_by_name_ht_node; + struct cds_lfht_iter iter; + /* TODO change hashing for trigger */ + cds_lfht_lookup(state->triggers_by_name_ht, + hash_key_str(name, lttng_ht_seed), + match_str, + name, + &iter); + triggers_by_name_ht_node = cds_lfht_iter_get_node(&iter); + if (triggers_by_name_ht_node) { + return true; + } else { + return false; + } + +} +static +void generate_trigger_name(struct notification_thread_state *state, struct lttng_trigger *trigger, const char **name) +{ + /* Here the offset criteria guarantee an end. This will be a nice + * bikeshedding conversation. I would simply generate uuid and use them + * as trigger name. + */ + bool taken = false; + do { + lttng_trigger_generate_name(trigger, state->trigger_id.name_offset); + /* TODO error checking */ + lttng_trigger_get_name(trigger, name); + taken = trigger_name_taken(state, *name); + if (taken) { + state->trigger_id.name_offset++; + } + } while (taken || state->trigger_id.name_offset == UINT32_MAX); +} + +static bool action_is_notify(const struct lttng_action *action) +{ + /* TODO for action groups we need to iterate over all of them */ + enum lttng_action_type type = lttng_action_get_type_const(action); + bool ret = false; + enum lttng_action_status status; + const struct lttng_action *tmp; + unsigned int i, count; + + switch (type) { + case LTTNG_ACTION_TYPE_NOTIFY: + ret = true; + break; + case LTTNG_ACTION_TYPE_GROUP: + status = lttng_action_group_get_count(action, &count); + if (status != LTTNG_ACTION_STATUS_OK) { + assert(0); + } + for (i = 0; i < count; i++) { + tmp = lttng_action_group_get_at_index_const(action, i); + assert(tmp); + ret = action_is_notify(tmp); + if (ret) { + break; + } + } + break; + default: + ret = false; + break; + } + + return ret; +} + +/* + * TODO: REVIEW THIS COMMENT. + * 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. + * + * If a non-fatal error occurs, just set the cmd_result to the appropriate + * error code. + */ +static +int handle_notification_thread_command_register_trigger( + struct notification_thread_state *state, + struct lttng_trigger *trigger, + enum lttng_error_code *cmd_result) +{ + int ret = 0; + int is_supported; + struct lttng_condition *condition; + struct lttng_action *action; + struct lttng_trigger_ht_element *trigger_ht_element = NULL; + struct notification_trigger_tokens_ht_element *trigger_tokens_ht_element = NULL; + struct cds_lfht_node *node; + const char* trigger_name; + bool free_trigger = true; + + assert(trigger->creds.set); + + rcu_read_lock(); + + /* Set the trigger's key */ + lttng_trigger_set_key(trigger, state->trigger_id.token_generator); + + if (lttng_trigger_get_name(trigger, &trigger_name) == LTTNG_TRIGGER_STATUS_UNSET) { + generate_trigger_name(state, trigger, &trigger_name); + } else if (trigger_name_taken(state, trigger_name)) { + /* Not a fatal error */ + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + ret = 0; + goto error; + } + + condition = lttng_trigger_get_condition(trigger); + assert(condition); + + action = lttng_trigger_get_action(trigger); + assert(action); + + is_supported = condition_is_supported(condition); + if (is_supported < 0) { + goto error; + } else if (is_supported == 0) { + ret = 0; + *cmd_result = LTTNG_ERR_NOT_SUPPORTED; + goto error; + } + + is_supported = action_is_supported(action); + if (is_supported < 0) { + goto error; + } else if (is_supported == 0) { + ret = 0; + *cmd_result = LTTNG_ERR_NOT_SUPPORTED; + goto error; + } + + trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); + if (!trigger_ht_element) { + ret = -1; + goto error; + } + + /* Add trigger to the trigger_ht. */ + cds_lfht_node_init(&trigger_ht_element->node); + cds_lfht_node_init(&trigger_ht_element->node_by_name); + + /* + * This element own the trigger object from now own, this is why there + * is no lttng_trigger_get here. + * This thread is now the owner of the trigger object. + */ + trigger_ht_element->trigger = trigger; + + node = cds_lfht_add_unique(state->triggers_ht, + lttng_condition_hash(condition), + match_trigger, + trigger, + &trigger_ht_element->node); + if (node != &trigger_ht_element->node) { + /* Not a fatal error, simply report it to the client. */ + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + goto error_free_ht_element; + } + + node = cds_lfht_add_unique(state->triggers_by_name_ht, + hash_key_str(trigger_name, lttng_ht_seed), + match_str, + trigger_name, + &trigger_ht_element->node_by_name); + if (node != &trigger_ht_element->node_by_name) { + /* This should never happen */ + /* Not a fatal error, simply report it to the client. */ + /* TODO remove from the trigger_ht */ + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + goto error_free_ht_element; + } + + if (lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT) { + trigger_tokens_ht_element = zmalloc(sizeof(*trigger_tokens_ht_element)); + if (!trigger_tokens_ht_element) { + ret = -1; + goto error; + } + + /* Add trigger token to the trigger_tokens_ht. */ + cds_lfht_node_init(&trigger_tokens_ht_element->node); + trigger_tokens_ht_element->token = trigger->key.value; + trigger_tokens_ht_element->trigger = trigger; + + node = cds_lfht_add_unique(state->trigger_tokens_ht, + hash_key_u64(&trigger_tokens_ht_element->token, lttng_ht_seed), + match_trigger_token, + &trigger_tokens_ht_element->token, + &trigger_tokens_ht_element->node); + if (node != &trigger_tokens_ht_element->node) { + /* TODO: THIS IS A FATAL ERROR... should never happen */ + /* Not a fatal error, simply report it to the client. */ + *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. Same for token ht element if necessary. + */ + trigger_tokens_ht_element = NULL; + trigger_ht_element = NULL; + free_trigger = false; + + if (action_is_notify(action)) { + ret = action_notify_register_trigger(state, trigger); + if (ret < 0) { + /* TODO should cmd_result be set here? */ + ret = -1; + goto error_free_ht_element; } - free(client_list); } + + /* Increment the trigger unique id generator */ + state->trigger_id.token_generator++; + *cmd_result = LTTNG_OK; + error_free_ht_element: free(trigger_ht_element); + free(trigger_tokens_ht_element); error: if (free_trigger) { - struct lttng_action *action = lttng_trigger_get_action(trigger); - - lttng_condition_destroy(condition); - lttng_action_destroy(action); lttng_trigger_destroy(trigger); } rcu_read_unlock(); @@ -2157,16 +2698,16 @@ error: } static -void free_notification_client_list_rcu(struct rcu_head *node) +void free_lttng_trigger_ht_element_rcu(struct rcu_head *node) { - free(caa_container_of(node, struct notification_client_list, + free(caa_container_of(node, struct lttng_trigger_ht_element, rcu_node)); } static -void free_lttng_trigger_ht_element_rcu(struct rcu_head *node) +void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head *node) { - free(caa_container_of(node, struct lttng_trigger_ht_element, + free(caa_container_of(node, struct notification_trigger_tokens_ht_element, rcu_node)); } @@ -2180,19 +2721,22 @@ int handle_notification_thread_command_unregister_trigger( 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; + struct lttng_action *action = lttng_trigger_get_action(trigger); enum lttng_error_code cmd_reply; rcu_read_lock(); + /* TODO change hashing for trigger */ + /* TODO Disabling for the root user is not complete, for now the root + * user cannot disable the trigger from another user. + */ 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) { @@ -2209,13 +2753,7 @@ int handle_notification_thread_command_unregister_trigger( cds_list_for_each_entry_safe(trigger_element, tmp, &trigger_list->list, node) { - const struct lttng_condition *current_condition = - lttng_trigger_get_const_condition( - trigger_element->trigger); - - assert(current_condition); - if (!lttng_condition_is_equal(condition, - current_condition)) { + if (!lttng_trigger_is_equal(trigger, trigger_element->trigger)) { continue; } @@ -2226,30 +2764,45 @@ int handle_notification_thread_command_unregister_trigger( } } - /* - * Remove and release the client list from - * notification_trigger_clients_ht. - */ - client_list = get_client_list_from_condition(state, condition); - assert(client_list); + if (lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT) { + struct notification_trigger_tokens_ht_element *trigger_tokens_ht_element; + cds_lfht_for_each_entry(state->trigger_tokens_ht, &iter, trigger_tokens_ht_element, + node) { + if (!lttng_trigger_is_equal(trigger, trigger_tokens_ht_element->trigger)) { + continue; + } - cds_list_for_each_entry_safe(client_list_element, tmp, - &client_list->list, node) { - free(client_list_element); + /* TODO talk to all app and remove it */ + DBG("[notification-thread] Removed trigger from tokens_ht"); + cds_lfht_del(state->trigger_tokens_ht, + &trigger_tokens_ht_element->node); + call_rcu(&trigger_tokens_ht_element->rcu_node, free_notification_trigger_tokens_ht_element_rcu); + + break; + } + } + + if (action_is_notify(action)) { + /* + * Remove and release the client list from + * notification_trigger_clients_ht. + */ + client_list = get_client_list_from_condition(state, condition); + assert(client_list); + + /* Put new reference and the hashtable's reference. */ + notification_client_list_put(client_list); + notification_client_list_put(client_list); + client_list = NULL; } - cds_lfht_del(state->notification_trigger_clients_ht, - &client_list->notification_trigger_ht_node); - call_rcu(&client_list->rcu_node, free_notification_client_list_rcu); /* 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_ht, &trigger_ht_element->node_by_name); 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); call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu); end: @@ -2327,6 +2880,47 @@ int handle_notification_thread_command( cmd->parameters.session_rotation.location, &cmd->reply_code); break; + case NOTIFICATION_COMMAND_TYPE_ADD_APPLICATION: + ret = handle_notification_thread_command_add_application( + handle, + state, + cmd->parameters.application.read_side_trigger_event_application_pipe, + &cmd->reply_code); + break; + case NOTIFICATION_COMMAND_TYPE_REMOVE_APPLICATION: + ret = handle_notification_thread_command_remove_application( + handle, + state, + cmd->parameters.application.read_side_trigger_event_application_pipe, + &cmd->reply_code); + break; + case NOTIFICATION_COMMAND_TYPE_GET_TOKENS: + { + struct lttng_triggers *triggers = NULL; + ret = handle_notification_thread_command_get_tokens( + handle, state, &triggers, &cmd->reply_code); + cmd->reply.get_tokens.triggers = triggers; + ret = 0; + break; + + cmd->reply_code = LTTNG_OK; + ret = 0; + break; + } + case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS: + { + struct lttng_triggers *triggers = NULL; + ret = handle_notification_thread_command_list_triggers( + handle, + state, + cmd->parameters.list_triggers.uid, + cmd->parameters.list_triggers.gid, + &triggers, + &cmd->reply_code); + cmd->reply.list_triggers.triggers = triggers; + ret = 0; + break; + } case NOTIFICATION_COMMAND_TYPE_QUIT: DBG("[notification-thread] Received quit command"); cmd->reply_code = LTTNG_OK; @@ -2342,7 +2936,12 @@ int handle_notification_thread_command( } end: cds_list_del(&cmd->cmd_list_node); - lttng_waiter_wake_up(&cmd->reply_waiter); + if (cmd->is_async) { + free(cmd); + cmd = NULL; + } else { + lttng_waiter_wake_up(&cmd->reply_waiter); + } pthread_mutex_unlock(&handle->cmd_queue.lock); return ret; error_unlock: @@ -2355,12 +2954,6 @@ error: 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) { @@ -2384,11 +2977,14 @@ end: return ret; } +/* Client lock must be acquired by caller. */ static int client_reset_inbound_state(struct notification_client *client) { int ret; + ASSERT_LOCKED(client->lock); + ret = lttng_dynamic_buffer_set_size( &client->communication.inbound.buffer, 0); assert(!ret); @@ -2419,11 +3015,16 @@ int handle_notification_thread_client_connect( ret = -1; goto error; } + pthread_mutex_init(&client->lock, NULL); + client->id = state->next_notification_client_id++; CDS_INIT_LIST_HEAD(&client->condition_list); lttng_dynamic_buffer_init(&client->communication.inbound.buffer); lttng_dynamic_buffer_init(&client->communication.outbound.buffer); client->communication.inbound.expect_creds = true; + + pthread_mutex_lock(&client->lock); ret = client_reset_inbound_state(client); + pthread_mutex_unlock(&client->lock); if (ret) { ERR("[notification-thread] Failed to reset client communication's inbound state"); ret = 0; @@ -2467,6 +3068,9 @@ int handle_notification_thread_client_connect( 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; @@ -2475,9 +3079,45 @@ error: return ret; } -int handle_notification_thread_client_disconnect( - int client_socket, +/* RCU read-lock must be held by the caller. */ +static +int notification_thread_client_disconnect( + struct notification_client *client, struct notification_thread_state *state) +{ + int ret; + struct lttng_condition_list_element *condition_list_element, *tmp; + + /* Acquire the client lock to disable its communication atomically. */ + pthread_mutex_lock(&client->lock); + client->communication.active = false; + ret = lttng_poll_del(&state->events, client->socket); + if (ret) { + ERR("[notification-thread] Failed to remove client socket %d from poll set", + client->socket); + } + pthread_mutex_unlock(&client->lock); + + cds_lfht_del(state->client_socket_ht, &client->client_socket_ht_node); + cds_lfht_del(state->client_id_ht, &client->client_id_ht_node); + + /* Release all conditions to which the client was subscribed. */ + cds_list_for_each_entry_safe(condition_list_element, tmp, + &client->condition_list, node) { + (void) notification_thread_client_unsubscribe(client, + condition_list_element->condition, state, NULL); + } + + /* + * Client no longer accessible to other threads (through the + * client lists). + */ + notification_client_destroy(client, state); + return ret; +} + +int handle_notification_thread_client_disconnect( + int client_socket, struct notification_thread_state *state) { int ret = 0; struct notification_client *client; @@ -2494,13 +3134,7 @@ int handle_notification_thread_client_disconnect( 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; @@ -2516,11 +3150,11 @@ int handle_notification_thread_client_disconnect_all( 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; } @@ -2550,11 +3184,63 @@ int handle_notification_thread_trigger_unregister_all( } 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; + + ASSERT_LOCKED(client->lock); + + switch (transmission_status) { + case CLIENT_TRANSMISSION_STATUS_COMPLETE: + ret = lttng_poll_mod(&state->events, client->socket, + CLIENT_POLL_MASK_IN); + if (ret) { + goto end; + } + + client->communication.outbound.queued_command_reply = false; + client->communication.outbound.dropped_notification = false; + break; + case CLIENT_TRANSMISSION_STATUS_QUEUED: + /* + * We want to be notified whenever there is buffer space + * available to send the rest of the payload. + */ + ret = lttng_poll_mod(&state->events, client->socket, + CLIENT_POLL_MASK_IN_OUT); + if (ret) { + goto end; + } + break; + case CLIENT_TRANSMISSION_STATUS_FAIL: + ret = notification_thread_client_disconnect(client, state); + if (ret) { + goto end; + } + break; + case CLIENT_TRANSMISSION_STATUS_ERROR: + ret = -1; + goto end; + default: + abort(); + } +end: + return ret; +} + +/* Client lock must be acquired by caller. */ +static +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; + + ASSERT_LOCKED(client->lock); assert(client->communication.outbound.buffer.size != 0); to_send_count = client->communication.outbound.buffer.size; @@ -2580,25 +3266,12 @@ int client_flush_outgoing_queue(struct notification_client *client, 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; } else if (ret < 0) { /* Generic error, disconnect the client. */ - ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", + ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)", client->socket); - ret = handle_notification_thread_client_disconnect( - client->socket, state); - if (ret) { - goto error; - } + status = CLIENT_TRANSMISSION_STATUS_FAIL; } else { /* No error and flushed the queue completely. */ ret = lttng_dynamic_buffer_set_size( @@ -2606,21 +3279,15 @@ int client_flush_outgoing_queue(struct notification_client *client, if (ret) { goto error; } - ret = lttng_poll_mod(&state->events, client->socket, - CLIENT_POLL_MASK_IN); - if (ret) { - goto error; - } - - client->communication.outbound.queued_command_reply = false; - client->communication.outbound.dropped_notification = false; + status = CLIENT_TRANSMISSION_STATUS_COMPLETE; } - return 0; + return status; error: - return -1; + return CLIENT_TRANSMISSION_STATUS_ERROR; } +/* Client lock must be acquired by caller. */ static int client_send_command_reply(struct notification_client *client, struct notification_thread_state *state, @@ -2635,6 +3302,9 @@ int client_send_command_reply(struct notification_client *client, .size = sizeof(reply), }; char buffer[sizeof(msg) + sizeof(reply)]; + enum client_transmission_status transmission_status; + + ASSERT_LOCKED(client->lock); if (client->communication.outbound.queued_command_reply) { /* Protocol error. */ @@ -2650,22 +3320,214 @@ int client_send_command_reply(struct notification_client *client, &client->communication.outbound.buffer, buffer, sizeof(buffer)); if (ret) { - goto error; + goto error; + } + + transmission_status = client_flush_outgoing_queue(client); + ret = client_handle_transmission_status( + client, transmission_status, state); + if (ret) { + goto error; + } + + if (client->communication.outbound.buffer.size != 0) { + /* Queue could not be emptied. */ + client->communication.outbound.queued_command_reply = true; + } + + return 0; +error: + return -1; +} + +static +int client_handle_message_unknown(struct notification_client *client, + struct notification_thread_state *state) +{ + int ret; + + pthread_mutex_lock(&client->lock); + + /* + * Receiving message header. The function will be called again + * once the rest of the message as been received and can be + * interpreted. + */ + const struct lttng_notification_channel_message *msg; + + assert(sizeof(*msg) == client->communication.inbound.buffer.size); + msg = (const struct lttng_notification_channel_message *) + client->communication.inbound.buffer.data; + + if (msg->size == 0 || + msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { + ERR("[notification-thread] Invalid notification channel message: length = %u", + msg->size); + ret = -1; + goto end; + } + + switch (msg->type) { + case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: + case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: + case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: + break; + default: + ret = -1; + ERR("[notification-thread] Invalid notification channel message: unexpected message type"); + goto end; + } + + client->communication.inbound.bytes_to_receive = msg->size; + client->communication.inbound.msg_type = + (enum lttng_notification_channel_message_type) msg->type; + ret = lttng_dynamic_buffer_set_size( + &client->communication.inbound.buffer, msg->size); +end: + pthread_mutex_unlock(&client->lock); + return ret; +} + +static +int client_handle_message_handshake(struct notification_client *client, + struct notification_thread_state *state) +{ + int ret; + struct lttng_notification_channel_command_handshake *handshake_client; + const struct lttng_notification_channel_command_handshake handshake_reply = { + .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, + .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, + }; + const struct lttng_notification_channel_message msg_header = { + .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, + .size = sizeof(handshake_reply), + }; + enum lttng_notification_channel_status status = + LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; + char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; + enum client_transmission_status transmission_status; + + pthread_mutex_lock(&client->lock); + + memcpy(send_buffer, &msg_header, sizeof(msg_header)); + memcpy(send_buffer + sizeof(msg_header), &handshake_reply, + sizeof(handshake_reply)); + + handshake_client = + (struct lttng_notification_channel_command_handshake *) + client->communication.inbound.buffer + .data; + client->major = handshake_client->major; + client->minor = handshake_client->minor; + if (!client->communication.inbound.creds_received) { + ERR("[notification-thread] No credentials received from client"); + ret = -1; + goto end; + } + + client->uid = LTTNG_SOCK_GET_UID_CRED( + &client->communication.inbound.creds); + client->gid = LTTNG_SOCK_GET_GID_CRED( + &client->communication.inbound.creds); + DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", + client->uid, client->gid, (int) client->major, + (int) client->minor); + + if (handshake_client->major != + LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { + status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; + } + + ret = lttng_dynamic_buffer_append( + &client->communication.outbound.buffer, send_buffer, + sizeof(send_buffer)); + if (ret) { + ERR("[notification-thread] Failed to send protocol version to notification channel client"); + goto end; + } + + transmission_status = client_flush_outgoing_queue(client); + ret = client_handle_transmission_status( + client, transmission_status, state); + if (ret) { + goto end; + } + + ret = client_send_command_reply(client, state, status); + if (ret) { + ERR("[notification-thread] Failed to send reply to notification channel client"); + goto end; + } + + /* Set reception state to receive the next message header. */ + ret = client_reset_inbound_state(client); + if (ret) { + ERR("[notification-thread] Failed to reset client communication's inbound state"); + goto end; + } + client->validated = true; + client->communication.active = true; + +end: + pthread_mutex_unlock(&client->lock); + return ret; +} + +static +int client_handle_message_subscription( + struct notification_client *client, + enum lttng_notification_channel_message_type msg_type, + struct notification_thread_state *state) +{ + int ret; + struct lttng_condition *condition; + enum lttng_notification_channel_status status = + LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; + const struct lttng_buffer_view condition_view = + lttng_buffer_view_from_dynamic_buffer( + &client->communication.inbound.buffer, + 0, -1); + size_t expected_condition_size; + + pthread_mutex_lock(&client->lock); + expected_condition_size = client->communication.inbound.buffer.size; + pthread_mutex_unlock(&client->lock); + + ret = lttng_condition_create_from_buffer(&condition_view, &condition); + if (ret != expected_condition_size) { + ERR("[notification-thread] Malformed condition received from client"); + goto end; + } + + if (msg_type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { + ret = notification_thread_client_subscribe( + client, condition, state, &status); + } else { + ret = notification_thread_client_unsubscribe( + client, condition, state, &status); + } + if (ret) { + goto end; } - ret = client_flush_outgoing_queue(client, state); + pthread_mutex_lock(&client->lock); + ret = client_send_command_reply(client, state, status); if (ret) { - goto error; + ERR("[notification-thread] Failed to send reply to notification channel client"); + goto end_unlock; } - if (client->communication.outbound.buffer.size != 0) { - /* Queue could not be emptied. */ - client->communication.outbound.queued_command_reply = true; + /* Set reception state to receive the next message header. */ + ret = client_reset_inbound_state(client); + if (ret) { + ERR("[notification-thread] Failed to reset client communication's inbound state"); + goto end_unlock; } - return 0; -error: - return -1; +end_unlock: + pthread_mutex_unlock(&client->lock); +end: + return ret; } static @@ -2687,158 +3549,19 @@ int client_dispatch_message(struct notification_client *client, 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: @@ -2856,6 +3579,7 @@ int handle_notification_thread_client_in( struct notification_client *client; ssize_t recv_ret; size_t offset; + bool message_is_complete = false; client = get_client_from_socket(socket, state); if (!client) { @@ -2864,6 +3588,7 @@ int handle_notification_thread_client_in( goto end; } + pthread_mutex_lock(&client->lock); offset = client->communication.inbound.buffer.size - client->communication.inbound.bytes_to_receive; if (client->communication.inbound.expect_creds) { @@ -2880,12 +3605,17 @@ int handle_notification_thread_client_in( client->communication.inbound.buffer.data + offset, client->communication.inbound.bytes_to_receive); } + if (recv_ret >= 0) { + client->communication.inbound.bytes_to_receive -= recv_ret; + message_is_complete = client->communication.inbound + .bytes_to_receive == 0; + } + pthread_mutex_unlock(&client->lock); if (recv_ret < 0) { goto error_disconnect_client; } - client->communication.inbound.bytes_to_receive -= recv_ret; - if (client->communication.inbound.bytes_to_receive == 0) { + if (message_is_complete) { ret = client_dispatch_message(client, state); if (ret) { /* @@ -2894,13 +3624,11 @@ int handle_notification_thread_client_in( */ goto error_disconnect_client; } - } else { - goto end; } end: return ret; error_disconnect_client: - ret = handle_notification_thread_client_disconnect(socket, state); + ret = notification_thread_client_disconnect(client, state); return ret; } @@ -2910,6 +3638,7 @@ int handle_notification_thread_client_out( { int ret; struct notification_client *client; + enum client_transmission_status transmission_status; client = get_client_from_socket(socket, state); if (!client) { @@ -2918,7 +3647,11 @@ int handle_notification_thread_client_out( goto end; } - ret = client_flush_outgoing_queue(client, state); + pthread_mutex_lock(&client->lock); + 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; } @@ -3089,33 +3822,77 @@ end: } 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, 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) +{ + 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); +} + +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 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 = { @@ -3141,16 +3918,40 @@ int send_evaluation_to_clients(const struct lttng_trigger *trigger, ((struct lttng_notification_channel_message * ) msg_buffer.data)->size = (uint32_t) (msg_buffer.size - sizeof(msg_header)); + pthread_mutex_lock(&client_list->lock); cds_list_for_each_entry_safe(client_list_element, tmp, &client_list->list, node) { + 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 (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; + } + } + + /* TODO: what is the behavior for root client on non root + * trigger? Since multiple triggers (different user) can have the same condition + * but with different action group that can have each a notify. + * Does the root client receive multiple notification for all + * those triggers with the same condition or only notification + * for triggers the root user configured? + * For now we do the later. All users including the root user + * can only receive notification from trigger it registered. + */ + if (client->uid != trigger_creds->uid && client->gid != trigger_creds->gid) { + DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); + goto unlock_client; } DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", @@ -3163,37 +3964,302 @@ int send_evaluation_to_clients(const struct lttng_trigger *trigger, * 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) { + goto unlock_client; } - continue; } ret = lttng_dynamic_buffer_append_buffer( &client->communication.outbound.buffer, &msg_buffer); if (ret) { - goto end; + 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 end; + goto unlock_client; + } +unlock_client: + pthread_mutex_unlock(&client->lock); + if (ret) { + goto end_unlock_list; } } ret = 0; + +end_unlock_list: + pthread_mutex_unlock(&client_list->lock); end: lttng_dynamic_buffer_reset(&msg_buffer); return ret; } +int perform_event_action_notify(struct notification_thread_state *state, + const struct lttng_trigger *trigger, + const struct lttng_trigger_notification *notification, + const struct lttng_action *action) +{ + int ret; + struct notification_client_list *client_list; + struct lttng_evaluation *evaluation = NULL; + const struct lttng_credentials *creds = lttng_trigger_get_credentials(trigger); + + /* + * Check if any client is subscribed to the result of this + * evaluation. + */ + client_list = get_client_list_from_condition(state, trigger->condition); + assert(client_list); + if (cds_list_empty(&client_list->list)) { + ret = 0; + goto end; + } + + evaluation = lttng_evaluation_event_rule_create(trigger->name); + if (!evaluation) { + ERR("Failed to create event rule hit evaluation"); + ret = -1; + goto end; + } + + /* Dispatch evaluation result to all clients. + * Note that here the passed credentials are the one from the trigger, + * this is because there is no internal object binded to the trigger per + * see and the credential validation is done at the registration level + * for the event rule based trigger. For a channel the credential + * validation can only be done on notify since the trigger can be + * registered before the channel/session creation. + */ + ret = send_evaluation_to_clients(trigger, + evaluation, client_list, state, + creds->uid, + creds->gid); + lttng_evaluation_destroy(evaluation); + if (caa_unlikely(ret)) { + goto end; + } +end: + return ret; + +} + +/* This can be called recursively, pass NULL for action on the first iteration */ +int perform_event_action(struct notification_thread_state *state, + const struct lttng_trigger *trigger, + const struct lttng_trigger_notification *notification, + const struct lttng_action *action) +{ + int ret = 0; + enum lttng_action_type action_type; + + assert(trigger); + + if (!action) { + action = lttng_trigger_get_const_action(trigger); + } + + action_type = lttng_action_get_type_const(action); + DBG("Handling action %s for trigger id %s (%" PRIu64 ")", + lttng_action_type_string(action_type), trigger->name, + trigger->key.value); + + switch (action_type) { + case LTTNG_ACTION_TYPE_GROUP: + { + /* Recurse into the group */ + const struct lttng_action *tmp = NULL; + unsigned int count = 0; + (void) lttng_action_group_get_count(action, &count); + for (int i = 0; i < count; i++) { + tmp = lttng_action_group_get_at_index_const(action, i); + assert(tmp); + ret = perform_event_action(state, trigger, notification, tmp); + if (ret < 0) { + goto end; + } + } + break; + } + case LTTNG_ACTION_TYPE_NOTIFY: + { + ret = perform_event_action_notify(state, trigger, notification, action); + break; + } + default: + break; + } +end: + return ret; +} + +int handle_notification_thread_event(struct notification_thread_state *state, + int pipe, + enum lttng_domain_type domain) +{ + int ret; + struct lttng_ust_trigger_notification ust_notification; + uint64_t kernel_notification; + struct cds_lfht_node *node; + struct cds_lfht_iter iter; + struct notification_trigger_tokens_ht_element *element; + struct lttng_trigger_notification notification; + void *reception_buffer; + size_t reception_size; + enum action_executor_status executor_status; + struct notification_client_list *client_list = NULL; + + notification.type = domain; + + switch(domain) { + case LTTNG_DOMAIN_UST: + reception_buffer = (void *) &ust_notification; + reception_size = sizeof(ust_notification); + notification.u.ust = &ust_notification; + break; + case LTTNG_DOMAIN_KERNEL: + reception_buffer = (void *) &kernel_notification; + reception_size = sizeof(kernel_notification); + notification.u.kernel = &kernel_notification; + break; + default: + assert(0); + } + + /* + * The monitoring pipe only holds messages smaller than PIPE_BUF, + * ensuring that read/write of sampling messages are atomic. + */ + /* TODO: should we read as much as we can ? EWOULDBLOCK? */ + + ret = lttng_read(pipe, reception_buffer, reception_size); + if (ret != reception_size) { + ERR("[notification-thread] Failed to read from event source pipe (fd = %i)", + pipe); + /* TODO: Should this error out completly. + * This can happen when an app is killed as of today + * ret = -1 cause the whole thread to die and fuck up + * everything. + */ + goto end; + } + + switch(domain) { + case LTTNG_DOMAIN_UST: + notification.id = ust_notification.id; + break; + case LTTNG_DOMAIN_KERNEL: + notification.id = kernel_notification; + break; + default: + assert(0); + } + + /* Find triggers associated with this token. */ + rcu_read_lock(); + cds_lfht_lookup(state->trigger_tokens_ht, + hash_key_u64(¬ification.id, lttng_ht_seed), match_trigger_token, + ¬ification.id, &iter); + node = cds_lfht_iter_get_node(&iter); + if (caa_unlikely(!node)) { + /* TODO: is this an error? This might happen if the receive side + * is slow to process event from source and that the trigger was + * removed but the app still kicking. This yield another + * question on the trigger lifetime and when we can remove a + * trigger. How to guarantee that all event with the token idea + * have be processed? Do we want to provide this guarantee? + * + * Update: I have encountered this when using a trigger on + * sched_switch and then removing it. The frequency is quite + * high hence we en up exactly in the mentionned scenario. + * AFAIK this might be the best way to handle this. + */ + ret = 0; + goto end_unlock; + } + element = caa_container_of(node, + struct notification_trigger_tokens_ht_element, + node); + + if (!lttng_trigger_is_ready_to_fire(element->trigger)) { + ret = 0; + goto end_unlock; + } + + client_list = get_client_list_from_condition(state, + lttng_trigger_get_const_condition(element->trigger)); + executor_status = action_executor_enqueue( + state->executor, element->trigger, client_list); + switch (executor_status) { + case ACTION_EXECUTOR_STATUS_OK: + ret = 0; + break; + case ACTION_EXECUTOR_STATUS_OVERFLOW: + { + struct notification_client_list_element *client_list_element, + *tmp; + + /* + * Not a fatal error; this is expected and simply means the + * executor has too much work queued already. + */ + ret = 0; + + if (!client_list) { + break; + } + + /* Warn clients that a notification (or more) was dropped. */ + 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; + + pthread_mutex_lock(&client->lock); + ret = client_notification_overflow(client); + if (ret) { + /* Fatal error. */ + goto next_client; + } + + transmission_status = + client_flush_outgoing_queue(client); + ret = client_handle_transmission_status( + client, transmission_status, state); + if (ret) { + /* Fatal error. */ + goto next_client; + } +next_client: + pthread_mutex_unlock(&client->lock); + if (ret) { + break; + } + } + pthread_mutex_lock(&client_list->lock); + break; + } + case ACTION_EXECUTOR_STATUS_ERROR: + /* Fatal error, shut down everything. */ + ERR("Fatal error encoutered while enqueuing action"); + ret = -1; + goto end_unlock; + default: + /* Unhandled error. */ + abort(); + } + +end_unlock: + notification_client_list_put(client_list); + rcu_read_unlock(); +end: + return ret; +} + int handle_notification_thread_channel_sample( struct notification_thread_state *state, int pipe, enum lttng_domain_type domain) @@ -3332,16 +4398,23 @@ int handle_notification_thread_channel_sample( 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; + bool client_list_is_empty; + ret = 0; trigger = trigger_list_element->trigger; condition = lttng_trigger_get_const_condition(trigger); assert(condition); action = lttng_trigger_get_const_action(trigger); + + if (!lttng_trigger_is_ready_to_fire(trigger)) { + goto put_list; + } /* Notify actions are the only type currently supported. */ + /* TODO support other type of action */ assert(lttng_action_get_type_const(action) == LTTNG_ACTION_TYPE_NOTIFY); @@ -3351,12 +4424,13 @@ int handle_notification_thread_channel_sample( */ client_list = get_client_list_from_condition(state, condition); assert(client_list); - if (cds_list_empty(&client_list->list)) { + client_list_is_empty = cds_list_empty(&client_list->list); + if (client_list_is_empty) { /* * No clients interested in the evaluation's result, * skip it. */ - continue; + goto put_list; } ret = evaluate_buffer_condition(condition, &evaluation, state, @@ -3366,11 +4440,11 @@ int handle_notification_thread_channel_sample( latest_session_consumed_total, channel_info); if (caa_unlikely(ret)) { - goto end_unlock; + goto put_list; } if (caa_likely(!evaluation)) { - continue; + goto put_list; } /* Dispatch evaluation result to all clients. */ @@ -3379,8 +4453,10 @@ int handle_notification_thread_channel_sample( channel_info->session_info->uid, channel_info->session_info->gid); lttng_evaluation_destroy(evaluation); +put_list: + notification_client_list_put(client_list); if (caa_unlikely(ret)) { - goto end_unlock; + break; } } end_unlock: