X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;h=827cf2c1459f5ee4cb683ac3fd5b0699ab5d9b82;hp=40450304297230b96cdf980afde1b516dc6c02c9;hb=f712e5f6c7a77e92abed2f0d0740b9512d1fa4e2;hpb=f8522f5cc357c0d80257d5ace1cd556a88305c0c diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c index 404503042..827cf2c14 100644 --- a/src/bin/lttng-sessiond/notification-thread-events.c +++ b/src/bin/lttng-sessiond/notification-thread-events.c @@ -21,13 +21,18 @@ #include #include #include +#include +#include #include #include #include #include #include +#include +#include #include #include +#include #include #include @@ -35,6 +40,8 @@ #include #include +#include "condition-internal.h" +#include "event-notifier-error-accounting.h" #include "notification-thread.h" #include "notification-thread-events.h" #include "notification-thread-commands.h" @@ -44,6 +51,9 @@ #define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) #define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) +/* The tracers currently limit the capture size to PIPE_BUF (4kb on linux). */ +#define MAX_CAPTURE_SIZE (PIPE_BUF) + enum lttng_object_type { LTTNG_OBJECT_TYPE_UNKNOWN, LTTNG_OBJECT_TYPE_NONE, @@ -112,6 +122,7 @@ struct lttng_trigger_ht_element { struct lttng_trigger *trigger; struct cds_lfht_node node; struct cds_lfht_node node_by_name_uid; + struct cds_list_head client_list_trigger_node; /* call_rcu delayed reclaim. */ struct rcu_head rcu_node; }; @@ -189,6 +200,11 @@ int client_handle_transmission_status( enum client_transmission_status transmission_status, struct notification_thread_state *state); +static +int handle_one_event_notifier_notification( + struct notification_thread_state *state, + int pipe, enum lttng_domain_type domain); + static void free_lttng_trigger_ht_element_rcu(struct rcu_head *node); @@ -277,6 +293,17 @@ int match_trigger(struct cds_lfht_node *node, const void *key) return !!lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger); } +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 int match_client_list_condition(struct cds_lfht_node *node, const void *key) { @@ -288,7 +315,7 @@ int match_client_list_condition(struct cds_lfht_node *node, const void *key) client_list = caa_container_of(node, struct notification_client_list, notification_trigger_clients_ht_node); - condition = lttng_trigger_get_const_condition(client_list->trigger); + condition = client_list->condition; return !!lttng_condition_is_equal(condition_key, condition); } @@ -303,6 +330,38 @@ int match_session(struct cds_lfht_node *node, const void *key) return !strcmp(session_info->name, name); } +static +const char *notification_command_type_str( + enum notification_thread_command_type type) +{ + switch (type) { + case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: + return "REGISTER_TRIGGER"; + case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: + return "UNREGISTER_TRIGGER"; + case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: + return "ADD_CHANNEL"; + case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: + return "REMOVE_CHANNEL"; + case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING: + return "SESSION_ROTATION_ONGOING"; + case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED: + return "SESSION_ROTATION_COMPLETED"; + case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE: + return "ADD_TRACER_EVENT_SOURCE"; + case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE: + return "REMOVE_TRACER_EVENT_SOURCE"; + case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS: + return "LIST_TRIGGERS"; + case NOTIFICATION_COMMAND_TYPE_QUIT: + return "QUIT"; + case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE: + return "CLIENT_COMMUNICATION_UPDATE"; + default: + abort(); + } +} + /* * Match trigger based on name and credentials only. * Name duplication is NOT allowed for the same uid. @@ -368,105 +427,6 @@ unsigned long hash_trigger_by_name_uid(const struct lttng_trigger *trigger) return hash; } -static -unsigned long lttng_condition_buffer_usage_hash( - const struct lttng_condition *_condition) -{ - unsigned long hash; - unsigned long condition_type; - struct lttng_condition_buffer_usage *condition; - - condition = container_of(_condition, - struct lttng_condition_buffer_usage, parent); - - condition_type = (unsigned long) condition->parent.type; - hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); - if (condition->session_name) { - hash ^= hash_key_str(condition->session_name, lttng_ht_seed); - } - if (condition->channel_name) { - hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); - } - if (condition->domain.set) { - hash ^= hash_key_ulong( - (void *) condition->domain.type, - lttng_ht_seed); - } - if (condition->threshold_ratio.set) { - uint64_t val; - - val = condition->threshold_ratio.value * (double) UINT32_MAX; - hash ^= hash_key_u64(&val, lttng_ht_seed); - } else if (condition->threshold_bytes.set) { - uint64_t val; - - val = condition->threshold_bytes.value; - hash ^= hash_key_u64(&val, lttng_ht_seed); - } - return hash; -} - -static -unsigned long lttng_condition_session_consumed_size_hash( - const struct lttng_condition *_condition) -{ - unsigned long hash; - unsigned long condition_type = - (unsigned long) LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE; - struct lttng_condition_session_consumed_size *condition; - uint64_t val; - - condition = container_of(_condition, - struct lttng_condition_session_consumed_size, parent); - - hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); - if (condition->session_name) { - hash ^= hash_key_str(condition->session_name, lttng_ht_seed); - } - val = condition->consumed_threshold_bytes.value; - hash ^= hash_key_u64(&val, lttng_ht_seed); - return hash; -} - -static -unsigned long lttng_condition_session_rotation_hash( - const struct lttng_condition *_condition) -{ - unsigned long hash, condition_type; - struct lttng_condition_session_rotation *condition; - - condition = container_of(_condition, - struct lttng_condition_session_rotation, parent); - condition_type = (unsigned long) condition->parent.type; - hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); - assert(condition->session_name); - hash ^= hash_key_str(condition->session_name, lttng_ht_seed); - return hash; -} - -/* - * The lttng_condition hashing code is kept in this file (rather than - * condition.c) since it makes use of GPLv2 code (hashtable utils), which we - * don't want to link in liblttng-ctl. - */ -static -unsigned long lttng_condition_hash(const struct lttng_condition *condition) -{ - switch (condition->type) { - case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: - case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: - return lttng_condition_buffer_usage_hash(condition); - case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: - return lttng_condition_session_consumed_size_hash(condition); - case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: - case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: - return lttng_condition_session_rotation_hash(condition); - default: - ERR("[notification-thread] Unexpected condition type caught"); - abort(); - } -} - static unsigned long hash_channel_key(struct channel_key *key) { @@ -509,6 +469,8 @@ 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_ON_EVENT: + return LTTNG_OBJECT_TYPE_NONE; default: return LTTNG_OBJECT_TYPE_UNKNOWN; } @@ -700,62 +662,121 @@ void notification_client_list_release(struct urcu_ref *list_ref) container_of(list_ref, typeof(*list), ref); struct notification_client_list_element *client_list_element, *tmp; + lttng_condition_put(list->condition); + 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) { + &list->clients_list, node) { free(client_list_element); } + + assert(cds_list_empty(&list->triggers_list)); + pthread_mutex_destroy(&list->lock); call_rcu(&list->rcu_node, free_notification_client_list_rcu); } +static +bool condition_applies_to_client(const struct lttng_condition *condition, + struct notification_client *client) +{ + bool applies = false; + struct lttng_condition_list_element *condition_list_element; + + cds_list_for_each_entry(condition_list_element, &client->condition_list, + node) { + applies = lttng_condition_is_equal( + condition_list_element->condition, + condition); + if (applies) { + break; + } + } + + return applies; +} + static struct notification_client_list *notification_client_list_create( - const struct lttng_trigger *trigger) + struct notification_thread_state *state, + const struct lttng_condition *condition) { - struct notification_client_list *client_list = - zmalloc(sizeof(*client_list)); + struct notification_client *client; + struct cds_lfht_iter iter; + struct notification_client_list *client_list; + client_list = zmalloc(sizeof(*client_list)); if (!client_list) { - goto error; + PERROR("Failed to allocate notification client list"); + goto end; } + pthread_mutex_init(&client_list->lock, NULL); + /* + * The trigger that owns the condition has the first reference to this + * client list. + */ 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; -} + CDS_INIT_LIST_HEAD(&client_list->clients_list); + CDS_INIT_LIST_HEAD(&client_list->triggers_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); + /* + * Create a copy of the condition so that it's independent of any + * trigger. The client list may outlive the trigger object (which owns + * the condition) that is used to create it. + */ + client_list->condition = lttng_condition_copy(condition); + + /* Build a list of clients to which this new condition applies. */ + cds_lfht_for_each_entry (state->client_socket_ht, &iter, client, + client_socket_ht_node) { + struct notification_client_list_element *client_list_element; + + if (!condition_applies_to_client(condition, client)) { + continue; + } + + client_list_element = zmalloc(sizeof(*client_list_element)); + if (!client_list_element) { + goto error_put_client_list; + } - assert(!list->notification_trigger_clients_ht); - notification_client_list_get(list); + CDS_INIT_LIST_HEAD(&client_list_element->node); + client_list_element->client = client; + cds_list_add(&client_list_element->node, &client_list->clients_list); + } - list->notification_trigger_clients_ht = + client_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); + /* + * Add the client list to the global list of client list. + */ + cds_lfht_add_unique(state->notification_trigger_clients_ht, + lttng_condition_hash(client_list->condition), + match_client_list_condition, + client_list->condition, + &client_list->notification_trigger_clients_ht_node); rcu_read_unlock(); + goto end; + +error_put_client_list: + notification_client_list_put(client_list); + client_list = NULL; + +end: + return client_list; } -LTTNG_HIDDEN void notification_client_list_put(struct notification_client_list *list) { if (!list) { @@ -1019,6 +1040,7 @@ 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 bound to object, nothing to evaluate"); ret = 0; goto end; case LTTNG_OBJECT_TYPE_UNKNOWN: @@ -1042,12 +1064,11 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, * subscribing. */ cds_lfht_node_init(&client_list.notification_trigger_clients_ht_node); - CDS_INIT_LIST_HEAD(&client_list.list); - client_list.trigger = trigger; + CDS_INIT_LIST_HEAD(&client_list.clients_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_list_add(&client_list_element.node, &client_list.clients_list); /* Send evaluation result to the newly-subscribed client. */ DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); @@ -1068,6 +1089,7 @@ int notification_thread_client_subscribe(struct notification_client *client, 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; + struct lttng_trigger_ht_element *trigger_ht_element; enum lttng_notification_channel_status status = LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; @@ -1117,17 +1139,24 @@ int notification_thread_client_subscribe(struct notification_client *client, * 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. + * Note the iteration on all triggers which share an identical + * `condition` than the one to which the client is registering. This is + * done to ensure that the client receives a distinct notification for + * all triggers that have a `notify` action that have this condition. */ - 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; + pthread_mutex_lock(&client_list->lock); + cds_list_for_each_entry(trigger_ht_element, + &client_list->triggers_list, client_list_trigger_node) { + if (evaluate_condition_for_client(trigger_ht_element->trigger, condition, + client, state)) { + WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); + ret = -1; + free(client_list_element); + pthread_mutex_unlock(&client_list->lock); + goto end; + } } + pthread_mutex_unlock(&client_list->lock); /* * Add the client to the list of clients interested in a given trigger @@ -1138,7 +1167,7 @@ int notification_thread_client_subscribe(struct notification_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); + cds_list_add(&client_list_element->node, &client_list->clients_list); pthread_mutex_unlock(&client_list->lock); end: if (_status) { @@ -1209,7 +1238,7 @@ int notification_thread_client_unsubscribe( pthread_mutex_lock(&client_list->lock); cds_list_for_each_entry_safe(client_list_element, client_tmp, - &client_list->list, node) { + &client_list->clients_list, node) { if (client_list_element->client->id != client->id) { continue; } @@ -1402,25 +1431,6 @@ fail: return false; } -static -bool trigger_applies_to_client(struct lttng_trigger *trigger, - struct notification_client *client) -{ - bool applies = false; - struct lttng_condition_list_element *condition_list_element; - - cds_list_for_each_entry(condition_list_element, &client->condition_list, - node) { - applies = lttng_condition_is_equal( - condition_list_element->condition, - lttng_trigger_get_condition(trigger)); - if (applies) { - break; - } - } - return applies; -} - /* Must be called with RCU read lock held. */ static struct lttng_session_trigger_list *get_session_trigger_list( @@ -1690,7 +1700,7 @@ int handle_notification_thread_command_add_channel( DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", channel_name, session_name, channel_key_int, - channel_domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); + lttng_domain_type_str(channel_domain)); CDS_INIT_LIST_HEAD(&trigger_list); @@ -1791,7 +1801,7 @@ int handle_notification_thread_command_remove_channel( struct channel_info *channel_info; DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", - channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); + channel_key, lttng_domain_type_str(domain)); rcu_read_lock(); @@ -1985,110 +1995,422 @@ end: } static -int condition_is_supported(struct lttng_condition *condition) +int handle_notification_thread_command_add_tracer_event_source( + struct notification_thread_state *state, + int tracer_event_source_fd, + enum lttng_domain_type domain_type, + enum lttng_error_code *_cmd_result) { - int ret; + int ret = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_tracer_event_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; - } + element->fd = tracer_event_source_fd; + element->domain = domain_type; - if (domain != LTTNG_DOMAIN_KERNEL) { - ret = 1; - goto end; - } + cds_list_add(&element->node, &state->tracer_event_sources_list); - /* - * 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; + DBG3("[notification-thread] Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(domain_type)); + + /* Adding the read side pipe to the event poll. */ + ret = lttng_poll_add(&state->events, tracer_event_source_fd, LPOLLIN | LPOLLERR); + if (ret < 0) { + ERR("[notification-thread] Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(element->domain)); + cds_list_del(&element->node); + free(element); + goto end; } + + element->is_fd_in_poll_set = true; + end: + *_cmd_result = cmd_result; 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 drain_event_notifier_notification_pipe( + struct notification_thread_state *state, + int pipe, enum lttng_domain_type domain) { - 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; + struct lttng_poll_event events = {0}; + int ret; - status = lttng_condition_session_rotation_get_session_name( - condition, &session_name); - if (status != LTTNG_CONDITION_STATUS_OK) { - ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); - ret = -1; - goto end; - } - break; - } - default: - ret = -1; + ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); + if (ret < 0) { + ERR("[notification-thread] Error creating lttng_poll_event"); goto end; } - trigger_list = get_session_trigger_list(state, session_name); - if (!trigger_list) { - DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", - session_name); + ret = lttng_poll_add(&events, pipe, LPOLLIN); + if (ret < 0) { + ERR("[notification-thread] Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d", + pipe); goto end; - } - DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", - session_name); - ret = lttng_session_trigger_list_add(trigger_list, trigger); + while (true) { + /* + * Continue to consume notifications as long as there are new + * ones coming in. The tracer has been asked to stop producing + * them. + * + * LPOLLIN is explicitly checked since LPOLLHUP is implicitly + * monitored (on Linux, at least) and will be returned when + * the pipe is closed but empty. + */ + ret = lttng_poll_wait_interruptible(&events, 0); + if (ret == 0 || (LTTNG_POLL_GETEV(&events, 0) & LPOLLIN) == 0) { + /* No more notification to be read on this pipe. */ + ret = 0; + goto end; + } else if (ret < 0) { + PERROR("Failed on lttng_poll_wait_interruptible() call"); + ret = -1; + goto end; + } + + ret = handle_one_event_notifier_notification(state, pipe, domain); + if (ret) { + ERR("[notification-thread] Error consuming an event notifier notification from pipe: fd = %d", + pipe); + } + } end: + lttng_poll_clean(&events); return ret; } -/* Must be called with RCU read lock held. */ static -int bind_trigger_to_matching_channels(struct lttng_trigger *trigger, - struct notification_thread_state *state) +int handle_notification_thread_command_remove_tracer_event_source( + struct notification_thread_state *state, + int tracer_event_source_fd, + enum lttng_error_code *_cmd_result) { int ret = 0; - struct cds_lfht_node *node; - struct cds_lfht_iter iter; - struct channel_info *channel; - - cds_lfht_for_each_entry(state->channels_ht, &iter, channel, - channels_ht_node) { - struct lttng_trigger_list_element *trigger_list_element; - struct lttng_channel_trigger_list *trigger_list; - struct cds_lfht_iter lookup_iter; + bool found = false; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_tracer_event_source_element *source_element = NULL, *tmp; - if (!trigger_applies_to_channel(trigger, channel)) { + cds_list_for_each_entry_safe(source_element, tmp, + &state->tracer_event_sources_list, node) { + if (source_element->fd != tracer_event_source_fd) { continue; } - cds_lfht_lookup(state->channel_triggers_ht, + DBG("[notification-thread] Removed tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + cds_list_del(&source_element->node); + found = true; + break; + } + + if (!found) { + /* + * This is temporarily allowed since the poll activity set is + * not properly cleaned-up for the moment. This is adressed in + * an upcoming fix. + */ + source_element = NULL; + goto end; + } + + if (!source_element->is_fd_in_poll_set) { + /* Skip the poll set removal. */ + goto end; + } + + DBG3("[notification-thread] Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + + /* Removing the fd from the event poll set. */ + ret = lttng_poll_del(&state->events, tracer_event_source_fd); + if (ret < 0) { + ERR("[notification-thread] Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + cmd_result = LTTNG_ERR_FATAL; + goto end; + } + + source_element->is_fd_in_poll_set = false; + + ret = drain_event_notifier_notification_pipe(state, tracer_event_source_fd, + source_element->domain); + if (ret) { + ERR("[notification-thread] Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + cmd_result = LTTNG_ERR_FATAL; + goto end; + } + + /* + * The drain_event_notifier_notification_pipe() call might have read + * data from an fd that we received in event in the latest _poll_wait() + * call. Make sure the thread call poll_wait() again to ensure we have + * a clean state. + */ + state->restart_poll = true; + +end: + free(source_element); + *_cmd_result = cmd_result; + return ret; +} + +static +int condition_on_event_update_error_count(struct lttng_trigger *trigger) +{ + int ret = 0; + uint64_t error_count = 0; + struct lttng_condition *condition; + enum event_notifier_error_accounting_status status; + + condition = lttng_trigger_get_condition(trigger); + assert(lttng_condition_get_type(condition) == + LTTNG_CONDITION_TYPE_ON_EVENT); + + status = event_notifier_error_accounting_get_count(trigger, &error_count); + if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) { + uid_t trigger_owner_uid; + const char *trigger_name; + const enum lttng_trigger_status trigger_status = + lttng_trigger_get_owner_uid( + trigger, &trigger_owner_uid); + + assert(trigger_status == LTTNG_TRIGGER_STATUS_OK); + if (lttng_trigger_get_name(trigger, &trigger_name) != LTTNG_TRIGGER_STATUS_OK) { + trigger_name = "(unnamed)"; + } + + ERR("Failed to get event notifier error count of trigger for update: trigger owner = %d, trigger name = '%s'", + trigger_owner_uid, trigger_name); + ret = -1; + } + + lttng_condition_on_event_set_error_count(condition, error_count); + return ret; +} + +int handle_notification_thread_remove_tracer_event_source_no_result( + struct notification_thread_state *state, + int tracer_event_source_fd) +{ + int ret; + enum lttng_error_code cmd_result; + + ret = handle_notification_thread_command_remove_tracer_event_source( + state, tracer_event_source_fd, &cmd_result); + (void) cmd_result; + return ret; +} + +static int handle_notification_thread_command_list_triggers( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + uid_t client_uid, + struct lttng_triggers **triggers, + enum lttng_error_code *_cmd_result) +{ + int ret = 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; + + rcu_read_lock(); + + local_triggers = lttng_triggers_create(); + if (!local_triggers) { + /* Not a fatal error. */ + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + + cds_lfht_for_each_entry(state->triggers_ht, &iter, + trigger_ht_element, node) { + /* + * Only return the triggers to which the client has access. + * The root user has visibility over all triggers. + */ + creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); + if (client_uid != lttng_credentials_get_uid(creds) && client_uid != 0) { + continue; + } + + if (lttng_trigger_needs_tracer_notifier(trigger_ht_element->trigger)) { + ret = condition_on_event_update_error_count( + trigger_ht_element->trigger); + assert(!ret); + } + + ret = lttng_triggers_add(local_triggers, + trigger_ht_element->trigger); + if (ret < 0) { + /* Not a fatal error. */ + ret = 0; + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + } + + /* Transferring ownership to the caller. */ + *triggers = local_triggers; + local_triggers = NULL; + +end: + rcu_read_unlock(); + lttng_triggers_destroy(local_triggers); + *_cmd_result = cmd_result; + return ret; +} + +static +bool condition_is_supported(struct lttng_condition *condition) +{ + bool is_supported; + + switch (lttng_condition_get_type(condition)) { + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: + { + int ret; + enum lttng_domain_type domain; + + ret = lttng_condition_buffer_usage_get_domain_type(condition, + &domain); + assert(ret == 0); + + if (domain != LTTNG_DOMAIN_KERNEL) { + is_supported = true; + 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. + * + * Assume unsupported on error. + */ + is_supported = kernel_supports_ring_buffer_snapshot_sample_positions() == 1; + break; + } + case LTTNG_CONDITION_TYPE_ON_EVENT: + { + const struct lttng_event_rule *event_rule; + enum lttng_domain_type domain; + const enum lttng_condition_status status = + lttng_condition_on_event_get_rule( + condition, &event_rule); + + assert(status == LTTNG_CONDITION_STATUS_OK); + + domain = lttng_event_rule_get_domain_type(event_rule); + if (domain != LTTNG_DOMAIN_KERNEL) { + is_supported = true; + goto end; + } + + /* + * Older kernel tracers can't emit notification. Therefore, we + * reject triggers that require that mechanism to be available + * to be evaluated. + * + * Assume unsupported on error. + */ + is_supported = kernel_supports_event_notifiers() == 1; + break; + } + default: + is_supported = true; + } +end: + return is_supported; +} + +/* 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); + if (status != LTTNG_CONDITION_STATUS_OK) { + ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); + ret = -1; + goto end; + } + break; + } + default: + ret = -1; + goto end; + } + + trigger_list = get_session_trigger_list(state, session_name); + if (!trigger_list) { + DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", + session_name); + goto end; + + } + + DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", + session_name); + ret = lttng_session_trigger_list_add(trigger_list, trigger); +end: + return ret; +} + +/* Must be called with RCU read lock held. */ +static +int bind_trigger_to_matching_channels(struct lttng_trigger *trigger, + struct notification_thread_state *state) +{ + int ret = 0; + struct cds_lfht_node *node; + struct cds_lfht_iter iter; + struct channel_info *channel; + + cds_lfht_for_each_entry(state->channels_ht, &iter, channel, + channels_ht_node) { + struct lttng_trigger_list_element *trigger_list_element; + struct lttng_channel_trigger_list *trigger_list; + struct cds_lfht_iter lookup_iter; + + if (!trigger_applies_to_channel(trigger, channel)) { + continue; + } + + cds_lfht_lookup(state->channel_triggers_ht, hash_channel_key(&channel->key), match_channel_trigger_list, &channel->key, @@ -2196,6 +2518,79 @@ enum lttng_error_code generate_trigger_name( return ret_code; } +static inline +void notif_thread_state_remove_trigger_ht_elem( + struct notification_thread_state *state, + struct lttng_trigger_ht_element *trigger_ht_element) +{ + assert(state); + assert(trigger_ht_element); + + cds_lfht_del(state->triggers_ht, &trigger_ht_element->node); + cds_lfht_del(state->triggers_by_name_uid_ht, &trigger_ht_element->node_by_name_uid); +} + +static +enum lttng_error_code setup_tracer_notifier( + struct notification_thread_state *state, + struct lttng_trigger *trigger) +{ + enum lttng_error_code ret; + enum event_notifier_error_accounting_status error_accounting_status; + struct cds_lfht_node *node; + uint64_t error_counter_index = 0; + struct lttng_condition *condition = lttng_trigger_get_condition(trigger); + struct notification_trigger_tokens_ht_element *trigger_tokens_ht_element = NULL; + + trigger_tokens_ht_element = zmalloc(sizeof(*trigger_tokens_ht_element)); + if (!trigger_tokens_ht_element) { + ret = LTTNG_ERR_NOMEM; + goto end; + } + + /* Add trigger token to the trigger_tokens_ht. */ + cds_lfht_node_init(&trigger_tokens_ht_element->node); + trigger_tokens_ht_element->token = LTTNG_OPTIONAL_GET(trigger->tracer_token); + 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) { + ret = LTTNG_ERR_TRIGGER_EXISTS; + goto error_free_ht_element; + } + + error_accounting_status = event_notifier_error_accounting_register_event_notifier( + trigger, &error_counter_index); + if (error_accounting_status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) { + if (error_accounting_status == EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE) { + DBG("Trigger group error accounting counter full."); + ret = LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING_FULL; + } else { + ERR("Error registering trigger for error accounting"); + ret = LTTNG_ERR_EVENT_NOTIFIER_REGISTRATION; + } + + goto error_remove_ht_element; + } + + lttng_condition_on_event_set_error_counter_index( + condition, error_counter_index); + + ret = LTTNG_OK; + goto end; + +error_remove_ht_element: + cds_lfht_del(state->trigger_tokens_ht, &trigger_tokens_ht_element->node); +error_free_ht_element: + free(trigger_tokens_ht_element); +end: + return ret; +} + /* * FIXME A client's credentials are not checked when registering a trigger. * @@ -2219,12 +2614,9 @@ int handle_notification_thread_command_register_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; struct cds_lfht_node *node; - struct cds_lfht_iter iter; const char* trigger_name; bool free_trigger = true; struct lttng_evaluation *evaluation = NULL; @@ -2261,15 +2653,10 @@ int handle_notification_thread_command_register_trigger( condition = lttng_trigger_get_condition(trigger); assert(condition); - ret = condition_is_supported(condition); - if (ret < 0) { - goto error; - } else if (ret == 0) { + /* Some conditions require tracers to implement a minimal ABI version. */ + if (!condition_is_supported(condition)) { *cmd_result = LTTNG_ERR_NOT_SUPPORTED; goto error; - } else { - /* Feature is supported, continue. */ - ret = 0; } trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); @@ -2307,11 +2694,26 @@ int handle_notification_thread_command_register_trigger( } /* - * Ownership of the trigger and of its wrapper was transfered to - * the triggers_ht. + * Some triggers might need a tracer notifier depending on its + * condition and actions. */ - trigger_ht_element = NULL; - free_trigger = false; + if (lttng_trigger_needs_tracer_notifier(trigger)) { + enum lttng_error_code error_code; + + error_code = setup_tracer_notifier(state, trigger); + if (error_code != LTTNG_OK) { + notif_thread_state_remove_trigger_ht_elem(state, + trigger_ht_element); + if (error_code == LTTNG_ERR_NOMEM) { + ret = -1; + } else { + *cmd_result = error_code; + ret = 0; + } + + goto error_free_ht_element; + } + } /* * The rest only applies to triggers that have a "notify" action. @@ -2319,45 +2721,44 @@ int handle_notification_thread_command_register_trigger( * supported. */ if (is_trigger_action_notify(trigger)) { - client_list = notification_client_list_create(trigger); + /* + * Find or create the client list of this condition. It may + * already be present if another trigger is already registered + * with the same condition. + */ + client_list = get_client_list_from_condition(state, condition); if (!client_list) { - ret = -1; - goto error_free_ht_element; - } - - /* 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; + /* + * No client list for this condition yet. We create new + * one and build it up. + */ + client_list = notification_client_list_create(state, condition); + if (!client_list) { + ERR("Error creating notification client list for trigger %s", trigger->name); + goto error_free_ht_element; } - - CDS_INIT_LIST_HEAD(&client_list_element->node); - client_list_element->client = client; - cds_list_add(&client_list_element->node, - &client_list->list); } - /* - * Client list ownership transferred to the - * notification_trigger_clients_ht. - */ - publish_notification_client_list(state, client_list); + CDS_INIT_LIST_HEAD(&trigger_ht_element->client_list_trigger_node); + + pthread_mutex_lock(&client_list->lock); + cds_list_add(&trigger_ht_element->client_list_trigger_node, &client_list->triggers_list); + pthread_mutex_unlock(&client_list->lock); } + /* + * Ownership of the trigger and of its wrapper was transfered to + * the triggers_ht. Same for token ht element if necessary. + */ + trigger_ht_element = NULL; + free_trigger = false; + switch (get_condition_binding_object(condition)) { case LTTNG_OBJECT_TYPE_SESSION: /* Add the trigger to the list if it matches a known session. */ ret = bind_trigger_to_matching_session(trigger, state); if (ret) { - goto error_put_client_list; + goto error_free_ht_element; } break; case LTTNG_OBJECT_TYPE_CHANNEL: @@ -2367,7 +2768,7 @@ int handle_notification_thread_command_register_trigger( */ ret = bind_trigger_to_matching_channels(trigger, state); if (ret) { - goto error_put_client_list; + goto error_free_ht_element; } break; case LTTNG_OBJECT_TYPE_NONE: @@ -2375,7 +2776,7 @@ int handle_notification_thread_command_register_trigger( default: ERR("Unknown object type on which to bind a newly registered trigger was encountered"); ret = -1; - goto error_put_client_list; + goto error_free_ht_element; } /* @@ -2412,11 +2813,15 @@ int handle_notification_thread_command_register_trigger( ret = evaluate_session_condition_for_client(condition, state, &evaluation, &object_uid, &object_gid); + LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); + LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); break; case LTTNG_OBJECT_TYPE_CHANNEL: ret = evaluate_channel_condition_for_client(condition, state, &evaluation, &object_uid, &object_gid); + LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); + LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); break; case LTTNG_OBJECT_TYPE_NONE: ret = 0; @@ -2429,18 +2834,15 @@ int handle_notification_thread_command_register_trigger( if (ret) { /* Fatal error. */ - goto error_put_client_list; + goto error_free_ht_element; } - 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; + goto success; } /* @@ -2461,7 +2863,7 @@ int handle_notification_thread_command_register_trigger( */ ERR("Fatal error occurred while enqueuing action associated to newly registered trigger"); ret = -1; - goto error_put_client_list; + goto error_free_ht_element; case ACTION_EXECUTOR_STATUS_OVERFLOW: /* * TODO Add trigger identification (name/id) when @@ -2471,18 +2873,16 @@ int handle_notification_thread_command_register_trigger( */ WARN("No space left when enqueuing action associated to newly registered trigger"); ret = 0; - goto end; + goto success; default: abort(); } -end: +success: *cmd_result = LTTNG_OK; DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64, trigger_name, trigger_tracer_token); - -error_put_client_list: - notification_client_list_put(client_list); + goto end; error_free_ht_element: if (trigger_ht_element) { @@ -2490,11 +2890,11 @@ error_free_ht_element: call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu); } - error: if (free_trigger) { lttng_trigger_destroy(trigger); } +end: rcu_read_unlock(); return ret; } @@ -2506,10 +2906,47 @@ void free_lttng_trigger_ht_element_rcu(struct rcu_head *node) rcu_node)); } +static +void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head *node) +{ + free(caa_container_of(node, struct notification_trigger_tokens_ht_element, + rcu_node)); +} + +static +void teardown_tracer_notifier(struct notification_thread_state *state, + const struct lttng_trigger *trigger) +{ + struct cds_lfht_iter iter; + 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; + } + + event_notifier_error_accounting_unregister_event_notifier( + trigger_tokens_ht_element->trigger); + + /* 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; + } +} + static int handle_notification_thread_command_unregister_trigger( struct notification_thread_state *state, - struct lttng_trigger *trigger, + const struct lttng_trigger *trigger, enum lttng_error_code *_cmd_reply) { struct cds_lfht_iter iter; @@ -2517,7 +2954,7 @@ int handle_notification_thread_command_unregister_trigger( struct lttng_channel_trigger_list *trigger_list; struct notification_client_list *client_list; struct lttng_trigger_ht_element *trigger_ht_element = NULL; - struct lttng_condition *condition = lttng_trigger_get_condition( + const struct lttng_condition *condition = lttng_trigger_get_const_condition( trigger); enum lttng_error_code cmd_reply; @@ -2543,13 +2980,7 @@ 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; } @@ -2560,23 +2991,33 @@ 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); - - /* Put new reference and the hashtable's reference. */ - notification_client_list_put(client_list); - notification_client_list_put(client_list); - client_list = NULL; + if (lttng_trigger_needs_tracer_notifier(trigger)) { + teardown_tracer_notifier(state, trigger); + } - /* 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); + + if (is_trigger_action_notify(trigger)) { + /* + * Remove and release the client list from + * notification_trigger_clients_ht. + */ + client_list = get_client_list_from_condition(state, condition); + assert(client_list); + + pthread_mutex_lock(&client_list->lock); + cds_list_del(&trigger_ht_element->client_list_trigger_node); + pthread_mutex_unlock(&client_list->lock); + + /* 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. */ + notif_thread_state_remove_trigger_ht_elem(state, trigger_ht_element); /* Release the ownership of the trigger. */ lttng_trigger_destroy(trigger_ht_element->trigger); @@ -2610,21 +3051,22 @@ int handle_notification_thread_command( struct notification_thread_command, cmd_list_node); cds_list_del(&cmd->cmd_list_node); pthread_mutex_unlock(&handle->cmd_queue.lock); + + DBG("[notification-thread] Received `%s` command", + notification_command_type_str(cmd->type)); switch (cmd->type) { case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: - DBG("[notification-thread] Received register trigger command"); - ret = handle_notification_thread_command_register_trigger( - state, cmd->parameters.trigger, + ret = handle_notification_thread_command_register_trigger(state, + cmd->parameters.register_trigger.trigger, &cmd->reply_code); break; case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: - DBG("[notification-thread] Received unregister trigger command"); ret = handle_notification_thread_command_unregister_trigger( - state, cmd->parameters.trigger, + state, + cmd->parameters.unregister_trigger.trigger, &cmd->reply_code); break; case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: - DBG("[notification-thread] Received add channel command"); ret = handle_notification_thread_command_add_channel( state, cmd->parameters.add_channel.session.name, @@ -2637,7 +3079,6 @@ int handle_notification_thread_command( &cmd->reply_code); break; case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: - DBG("[notification-thread] Received remove channel command"); ret = handle_notification_thread_command_remove_channel( state, cmd->parameters.remove_channel.key, cmd->parameters.remove_channel.domain, @@ -2645,9 +3086,6 @@ int handle_notification_thread_command( break; case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING: case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED: - DBG("[notification-thread] Received session rotation %s command", - cmd->type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING ? - "ongoing" : "completed"); ret = handle_notification_thread_command_session_rotation( state, cmd->type, @@ -2658,8 +3096,34 @@ int handle_notification_thread_command( cmd->parameters.session_rotation.location, &cmd->reply_code); break; + case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE: + ret = handle_notification_thread_command_add_tracer_event_source( + state, + cmd->parameters.tracer_event_source.tracer_event_source_fd, + cmd->parameters.tracer_event_source.domain, + &cmd->reply_code); + break; + case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE: + ret = handle_notification_thread_command_remove_tracer_event_source( + state, + cmd->parameters.tracer_event_source.tracer_event_source_fd, + &cmd->reply_code); + 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, + &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; ret = 1; goto end; @@ -3750,8 +4214,7 @@ int send_evaluation_to_clients(const struct lttng_trigger *trigger, }; return notification_client_list_send_evaluation(client_list, - lttng_trigger_get_const_condition(trigger), evaluation, - lttng_trigger_get_credentials(trigger), + trigger, evaluation, &creds, client_handle_transmission_status_wrapper, state); } @@ -3792,9 +4255,8 @@ int send_evaluation_to_clients(const struct lttng_trigger *trigger, LTTNG_HIDDEN int notification_client_list_send_evaluation( struct notification_client_list *client_list, - const struct lttng_condition *condition, + const struct lttng_trigger *trigger, 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) @@ -3803,12 +4265,14 @@ int notification_client_list_send_evaluation( struct lttng_payload msg_payload; struct notification_client_list_element *client_list_element, *tmp; const struct lttng_notification notification = { - .condition = (struct lttng_condition *) condition, + .trigger = (struct lttng_trigger *) trigger, .evaluation = (struct lttng_evaluation *) evaluation, }; struct lttng_notification_channel_message msg_header = { .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION, }; + const struct lttng_credentials *trigger_creds = + lttng_trigger_get_credentials(trigger); lttng_payload_init(&msg_payload); @@ -3842,7 +4306,7 @@ int notification_client_list_send_evaluation( pthread_mutex_lock(&client_list->lock); cds_list_for_each_entry_safe(client_list_element, tmp, - &client_list->list, node) { + &client_list->clients_list, node) { enum client_transmission_status transmission_status; struct notification_client *client = client_list_element->client; @@ -3871,7 +4335,7 @@ int notification_client_list_send_evaluation( } } - if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) { + if (client->uid != lttng_credentials_get_uid(trigger_creds)) { DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); goto skip_client; } @@ -3926,6 +4390,285 @@ end: return ret; } +static +struct lttng_event_notifier_notification *recv_one_event_notifier_notification( + int notification_pipe_read_fd, enum lttng_domain_type domain) +{ + int ret; + uint64_t token; + struct lttng_event_notifier_notification *notification = NULL; + char *capture_buffer = NULL; + size_t capture_buffer_size; + void *reception_buffer; + size_t reception_size; + + struct lttng_ust_abi_event_notifier_notification ust_notification; + struct lttng_kernel_event_notifier_notification kernel_notification; + + /* Init lttng_event_notifier_notification */ + switch(domain) { + case LTTNG_DOMAIN_UST: + reception_buffer = (void *) &ust_notification; + reception_size = sizeof(ust_notification); + break; + case LTTNG_DOMAIN_KERNEL: + reception_buffer = (void *) &kernel_notification; + reception_size = sizeof(kernel_notification); + break; + default: + abort(); + } + + /* + * The monitoring pipe only holds messages smaller than PIPE_BUF, + * ensuring that read/write of tracer notifications are atomic. + */ + ret = lttng_read(notification_pipe_read_fd, reception_buffer, + reception_size); + if (ret != reception_size) { + PERROR("Failed to read from event source notification pipe: fd = %d, size to read = %zu, ret = %d", + notification_pipe_read_fd, reception_size, ret); + ret = -1; + goto end; + } + + switch(domain) { + case LTTNG_DOMAIN_UST: + token = ust_notification.token; + capture_buffer_size = ust_notification.capture_buf_size; + break; + case LTTNG_DOMAIN_KERNEL: + token = kernel_notification.token; + capture_buffer_size = kernel_notification.capture_buf_size; + break; + default: + abort(); + } + + if (capture_buffer_size == 0) { + capture_buffer = NULL; + goto skip_capture; + } + + if (capture_buffer_size > MAX_CAPTURE_SIZE) { + ERR("[notification-thread] Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes", + capture_buffer_size, MAX_CAPTURE_SIZE); + goto end; + } + + capture_buffer = zmalloc(capture_buffer_size); + if (!capture_buffer) { + ERR("[notification-thread] Failed to allocate capture buffer"); + goto end; + } + + /* Fetch additional payload (capture). */ + ret = lttng_read(notification_pipe_read_fd, capture_buffer, capture_buffer_size); + if (ret != capture_buffer_size) { + ERR("[notification-thread] Failed to read from event source pipe (fd = %i)", + notification_pipe_read_fd); + goto end; + } + +skip_capture: + notification = lttng_event_notifier_notification_create(token, domain, + capture_buffer, capture_buffer_size); + if (notification == NULL) { + goto end; + } + + /* + * Ownership transfered to the lttng_event_notifier_notification object. + */ + capture_buffer = NULL; + +end: + free(capture_buffer); + return notification; +} + +static +int dispatch_one_event_notifier_notification(struct notification_thread_state *state, + struct lttng_event_notifier_notification *notification) +{ + struct cds_lfht_node *node; + struct cds_lfht_iter iter; + struct notification_trigger_tokens_ht_element *element; + enum lttng_trigger_status trigger_status; + struct lttng_evaluation *evaluation = NULL; + enum action_executor_status executor_status; + struct notification_client_list *client_list = NULL; + const char *trigger_name; + int ret; + unsigned int capture_count = 0; + + /* Find triggers associated with this token. */ + rcu_read_lock(); + cds_lfht_lookup(state->trigger_tokens_ht, + hash_key_u64(¬ification->tracer_token, lttng_ht_seed), + match_trigger_token, ¬ification->tracer_token, &iter); + node = cds_lfht_iter_get_node(&iter); + if (caa_unlikely(!node)) { + /* + * This is not an error, slow consumption of the tracer + * notifications can lead to situations where a trigger is + * removed but we still get tracer notifications matching a + * trigger that no longer exists. + */ + ret = 0; + goto end_unlock; + } + + element = caa_container_of(node, + struct notification_trigger_tokens_ht_element, + node); + + if (!lttng_trigger_should_fire(element->trigger)) { + ret = 0; + goto end_unlock; + } + + lttng_trigger_fire(element->trigger); + + trigger_status = lttng_trigger_get_name(element->trigger, &trigger_name); + assert(trigger_status == LTTNG_TRIGGER_STATUS_OK); + + if (lttng_condition_on_event_get_capture_descriptor_count( + lttng_trigger_get_const_condition(element->trigger), + &capture_count) != LTTNG_CONDITION_STATUS_OK) { + ERR("Failed to get capture count"); + ret = -1; + goto end; + } + + if (!notification->capture_buffer && capture_count != 0) { + ERR("Expected capture but capture buffer is null"); + ret = -1; + goto end; + } + + evaluation = lttng_evaluation_on_event_create( + container_of(lttng_trigger_get_const_condition( + element->trigger), + struct lttng_condition_on_event, + parent), + notification->capture_buffer, + notification->capture_buf_size, false); + + if (evaluation == NULL) { + ERR("[notification-thread] Failed to create event rule hit evaluation while creating and enqueuing action executor job"); + ret = -1; + 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, evaluation, NULL, 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; + + /* No clients subscribed to notifications for this trigger. */ + 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->clients_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_unlock(&client_list->lock); + break; + } + case ACTION_EXECUTOR_STATUS_INVALID: + case ACTION_EXECUTOR_STATUS_ERROR: + /* Fatal error, shut down everything. */ + ERR("Fatal error encoutered while enqueuing action to the action executor"); + ret = -1; + goto end_unlock; + default: + /* Unhandled error. */ + abort(); + } + +end_unlock: + notification_client_list_put(client_list); + rcu_read_unlock(); +end: + return ret; +} + +static +int handle_one_event_notifier_notification( + struct notification_thread_state *state, + int pipe, enum lttng_domain_type domain) +{ + int ret = 0; + struct lttng_event_notifier_notification *notification = NULL; + + notification = recv_one_event_notifier_notification(pipe, domain); + if (notification == NULL) { + /* Reception failed, don't consider it fatal. */ + ERR("[notification-thread] Error receiving an event notifier notification from tracer: fd = %i, domain = %s", + pipe, lttng_domain_type_str(domain)); + goto end; + } + + ret = dispatch_one_event_notifier_notification(state, notification); + if (ret) { + ERR("[notification-thread] Error dispatching an event notifier notification from tracer: fd = %i, domain = %s", + pipe, lttng_domain_type_str(domain)); + goto end; + } + +end: + lttng_event_notifier_notification_destroy(notification); + return ret; +} + +int handle_notification_thread_event_notification(struct notification_thread_state *state, + int pipe, enum lttng_domain_type domain) +{ + return handle_one_event_notifier_notification(state, pipe, domain); +} + int handle_notification_thread_channel_sample( struct notification_thread_state *state, int pipe, enum lttng_domain_type domain) @@ -3979,8 +4722,7 @@ int handle_notification_thread_channel_sample( */ DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", latest_sample.key.key, - domain == LTTNG_DOMAIN_KERNEL ? "kernel" : - "user space"); + lttng_domain_type_str(domain)); goto end_unlock; } channel_info = caa_container_of(node, struct channel_info,