X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;h=c318f833c87f6f2930b1090b384f31cea3d62013;hp=e01a00538ba8d2f04c389086860ebfd933798e9f;hb=fbc9f37df245d544a7705ba576297df791220b44;hpb=17182cfd13b6d35cf8c80d4f9ccf8d2bdd1a05f2 diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c index e01a00538..c318f833c 100644 --- a/src/bin/lttng-sessiond/notification-thread-events.c +++ b/src/bin/lttng-sessiond/notification-thread-events.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -110,6 +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_uid; /* call_rcu delayed reclaim. */ struct rcu_head rcu_node; }; @@ -187,6 +189,9 @@ int client_handle_transmission_status( enum client_transmission_status transmission_status, struct notification_thread_state *state); +static +void free_lttng_trigger_ht_element_rcu(struct rcu_head *node); + static int match_client_socket(struct cds_lfht_node *node, const void *key) { @@ -261,18 +266,15 @@ 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; + struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; + struct lttng_trigger_ht_element *trigger_ht_element; - trigger = caa_container_of(node, struct lttng_trigger_ht_element, + trigger_ht_element = caa_container_of(node, struct lttng_trigger_ht_element, node); - condition = lttng_trigger_get_condition(trigger->trigger); - assert(condition); - return !!lttng_condition_is_equal(condition_key, condition); + return !!lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger); } static @@ -301,6 +303,71 @@ int match_session(struct cds_lfht_node *node, const void *key) return !strcmp(session_info->name, name); } +/* + * Match trigger based on name and credentials only. + * Name duplication is NOT allowed for the same uid. + */ +static +int match_trigger_by_name_uid(struct cds_lfht_node *node, + const void *key) +{ + bool match = false; + const char *name; + const char *key_name; + enum lttng_trigger_status status; + const struct lttng_credentials *key_creds; + const struct lttng_credentials *node_creds; + const struct lttng_trigger *trigger_key = + (const struct lttng_trigger *) key; + const struct lttng_trigger_ht_element *trigger_ht_element = + caa_container_of(node, + struct lttng_trigger_ht_element, + node_by_name_uid); + + status = lttng_trigger_get_name(trigger_ht_element->trigger, &name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + status = lttng_trigger_get_name(trigger_key, &key_name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + /* Compare the names. */ + if (strcmp(name, key_name) != 0) { + goto end; + } + + /* Compare the owners' UIDs. */ + key_creds = lttng_trigger_get_credentials(trigger_key); + node_creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); + + match = lttng_credentials_is_equal_uid(key_creds, node_creds); + +end: + return match; +} + +/* + * Hash trigger based on name and credentials only. + */ +static +unsigned long hash_trigger_by_name_uid(const struct lttng_trigger *trigger) +{ + unsigned long hash = 0; + const struct lttng_credentials *trigger_creds; + const char *trigger_name; + enum lttng_trigger_status status; + + status = lttng_trigger_get_name(trigger, &trigger_name); + if (status == LTTNG_TRIGGER_STATUS_OK) { + hash = hash_key_str(trigger_name, lttng_ht_seed); + } + + trigger_creds = lttng_trigger_get_credentials(trigger); + hash ^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds->uid), + lttng_ht_seed); + + return hash; +} + static unsigned long lttng_condition_buffer_usage_hash( const struct lttng_condition *_condition) @@ -1807,8 +1874,8 @@ int handle_notification_thread_command_session_rotation( struct lttng_trigger_list_element *trigger_list_element; struct session_info *session_info; const struct lttng_credentials session_creds = { - .uid = session_uid, - .gid = session_gid, + .uid = LTTNG_OPTIONAL_INIT_VALUE(session_uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(session_gid), }; rcu_read_lock(); @@ -1917,6 +1984,61 @@ end: 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; + } + + 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 int condition_is_supported(struct lttng_condition *condition) { @@ -2085,6 +2207,50 @@ end: return is_notify; } +static bool trigger_name_taken(struct notification_thread_state *state, + const struct lttng_trigger *trigger) +{ + struct cds_lfht_iter iter; + + /* + * No duplicata is allowed in the triggers_by_name_uid_ht. + * The match is done against the trigger name and uid. + */ + cds_lfht_lookup(state->triggers_by_name_uid_ht, + hash_trigger_by_name_uid(trigger), + match_trigger_by_name_uid, + trigger, + &iter); + return !!cds_lfht_iter_get_node(&iter); +} + +static +enum lttng_error_code generate_trigger_name( + struct notification_thread_state *state, + struct lttng_trigger *trigger, const char **name) +{ + enum lttng_error_code ret_code = LTTNG_OK; + bool taken = false; + enum lttng_trigger_status status; + + do { + const int ret = lttng_trigger_generate_name(trigger, + state->trigger_id.name_offset++); + if (ret) { + /* The only reason this can fail right now. */ + ret_code = LTTNG_ERR_NOMEM; + break; + } + + status = lttng_trigger_get_name(trigger, name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + taken = trigger_name_taken(state, trigger); + } while (taken || state->trigger_id.name_offset == UINT64_MAX); + + return ret_code; +} + /* * FIXME A client's credentials are not checked when registering a trigger. * @@ -2114,13 +2280,39 @@ int handle_notification_thread_command_register_trigger( struct notification_client_list_element *client_list_element; struct cds_lfht_node *node; struct cds_lfht_iter iter; + const char* trigger_name; bool free_trigger = true; struct lttng_evaluation *evaluation = NULL; struct lttng_credentials object_creds; + uid_t object_uid; + gid_t object_gid; enum action_executor_status executor_status; + const uint64_t trigger_tracer_token = + state->trigger_id.next_tracer_token++; rcu_read_lock(); + /* Set the trigger's tracer token. */ + lttng_trigger_set_tracer_token(trigger, trigger_tracer_token); + + if (lttng_trigger_get_name(trigger, &trigger_name) == + LTTNG_TRIGGER_STATUS_UNSET) { + const enum lttng_error_code ret_code = generate_trigger_name( + state, trigger, &trigger_name); + + if (ret_code != LTTNG_OK) { + /* Fatal error. */ + ret = -1; + *cmd_result = ret_code; + goto error; + } + } else if (trigger_name_taken(state, trigger)) { + /* Not a fatal error. */ + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + ret = 0; + goto error; + } + condition = lttng_trigger_get_condition(trigger); assert(condition); @@ -2143,12 +2335,13 @@ int handle_notification_thread_command_register_trigger( /* Add trigger to the trigger_ht. */ cds_lfht_node_init(&trigger_ht_element->node); + cds_lfht_node_init(&trigger_ht_element->node_by_name_uid); trigger_ht_element->trigger = trigger; node = cds_lfht_add_unique(state->triggers_ht, lttng_condition_hash(condition), - match_condition, - condition, + match_trigger, + trigger, &trigger_ht_element->node); if (node != &trigger_ht_element->node) { /* Not a fatal error, simply report it to the client. */ @@ -2156,6 +2349,18 @@ int handle_notification_thread_command_register_trigger( goto error_free_ht_element; } + node = cds_lfht_add_unique(state->triggers_by_name_uid_ht, + hash_trigger_by_name_uid(trigger), + match_trigger_by_name_uid, + trigger, + &trigger_ht_element->node_by_name_uid); + if (node != &trigger_ht_element->node_by_name_uid) { + /* Not a fatal error, simply report it to the client. */ + cds_lfht_del(state->triggers_ht, &trigger_ht_element->node); + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + goto error_free_ht_element; + } + /* * Ownership of the trigger and of its wrapper was transfered to * the triggers_ht. @@ -2260,21 +2465,21 @@ int handle_notification_thread_command_register_trigger( switch (get_condition_binding_object(condition)) { case LTTNG_OBJECT_TYPE_SESSION: ret = evaluate_session_condition_for_client(condition, state, - &evaluation, &object_creds.uid, - &object_creds.gid); + &evaluation, &object_uid, + &object_gid); break; case LTTNG_OBJECT_TYPE_CHANNEL: ret = evaluate_channel_condition_for_client(condition, state, - &evaluation, &object_creds.uid, - &object_creds.gid); + &evaluation, &object_uid, + &object_gid); break; case LTTNG_OBJECT_TYPE_NONE: ret = 0; - goto error_put_client_list; + break; case LTTNG_OBJECT_TYPE_UNKNOWN: default: ret = -1; - goto error_put_client_list; + break; } if (ret) { @@ -2282,12 +2487,15 @@ int handle_notification_thread_command_register_trigger( goto error_put_client_list; } + LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); + LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); + DBG("Newly registered trigger's condition evaluated to %s", evaluation ? "true" : "false"); if (!evaluation) { /* Evaluation yielded nothing. Normal exit. */ ret = 0; - goto error_put_client_list; + goto end; } /* @@ -2318,18 +2526,26 @@ int handle_notification_thread_command_register_trigger( */ WARN("No space left when enqueuing action associated to newly registered trigger"); ret = 0; - goto error_put_client_list; + goto end; default: abort(); } +end: *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); error_free_ht_element: - free(trigger_ht_element); + if (trigger_ht_element) { + /* Delayed removal due to RCU constraint on delete. */ + call_rcu(&trigger_ht_element->rcu_node, + free_lttng_trigger_ht_element_rcu); + } + error: if (free_trigger) { lttng_trigger_destroy(trigger); @@ -2364,8 +2580,8 @@ int handle_notification_thread_command_unregister_trigger( 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) { @@ -2414,6 +2630,7 @@ int handle_notification_thread_command_unregister_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); /* Release the ownership of the trigger. */ @@ -2496,6 +2713,20 @@ int handle_notification_thread_command( cmd->parameters.session_rotation.location, &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; @@ -3582,11 +3813,15 @@ int send_evaluation_to_clients(const struct lttng_trigger *trigger, struct notification_thread_state *state, uid_t object_uid, gid_t object_gid) { + const struct lttng_credentials creds = { + .uid = LTTNG_OPTIONAL_INIT_VALUE(object_uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(object_gid), + }; + return notification_client_list_send_evaluation(client_list, lttng_trigger_get_const_condition(trigger), evaluation, lttng_trigger_get_credentials(trigger), - &(struct lttng_credentials){ - .uid = object_uid, .gid = object_gid}, + &creds, client_handle_transmission_status_wrapper, state); } @@ -3693,8 +3928,8 @@ int notification_client_list_send_evaluation( } if (source_object_creds) { - if (client->uid != source_object_creds->uid && - client->gid != source_object_creds->gid && + if (client->uid != lttng_credentials_get_uid(source_object_creds) && + client->gid != lttng_credentials_get_gid(source_object_creds) && client->uid != 0) { /* * Client is not allowed to monitor this @@ -3705,7 +3940,7 @@ int notification_client_list_send_evaluation( } } - if (client->uid != trigger_creds->uid && client->gid != trigger_creds->gid) { + if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) { DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); goto skip_client; } @@ -3894,8 +4129,8 @@ int handle_notification_thread_channel_sample( } channel_creds = (typeof(channel_creds)) { - .uid = channel_info->session_info->uid, - .gid = channel_info->session_info->gid, + .uid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->gid), }; trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, @@ -3933,6 +4168,12 @@ int handle_notification_thread_channel_sample( goto put_list; } + if (!lttng_trigger_should_fire(trigger)) { + goto put_list; + } + + lttng_trigger_fire(trigger); + /* * Ownership of `evaluation` transferred to the action executor * no matter the result.