+++ /dev/null
-/*
- * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#include "lttng/action/action.h"
-#include "lttng/trigger/trigger-internal.h"
-#define _LGPL_SOURCE
-#include <urcu.h>
-#include <urcu/rculfhash.h>
-
-#include <common/defaults.h>
-#include <common/error.h>
-#include <common/futex.h>
-#include <common/unix.h>
-#include <common/dynamic-buffer.h>
-#include <common/hashtable/utils.h>
-#include <common/sessiond-comm/sessiond-comm.h>
-#include <common/macros.h>
-#include <lttng/condition/condition.h>
-#include <lttng/action/action-internal.h>
-#include <lttng/notification/notification-internal.h>
-#include <lttng/condition/condition-internal.h>
-#include <lttng/condition/buffer-usage-internal.h>
-#include <lttng/condition/session-consumed-size-internal.h>
-#include <lttng/condition/session-rotation-internal.h>
-#include <lttng/notification/channel-internal.h>
-
-#include <time.h>
-#include <unistd.h>
-#include <assert.h>
-#include <inttypes.h>
-#include <fcntl.h>
-
-#include "notification-thread.h"
-#include "notification-thread-events.h"
-#include "notification-thread-commands.h"
-#include "lttng-sessiond.h"
-#include "kernel.h"
-
-#define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP)
-#define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT)
-
-enum lttng_object_type {
- LTTNG_OBJECT_TYPE_UNKNOWN,
- LTTNG_OBJECT_TYPE_NONE,
- LTTNG_OBJECT_TYPE_CHANNEL,
- LTTNG_OBJECT_TYPE_SESSION,
-};
-
-struct lttng_trigger_list_element {
- /* No ownership of the trigger object is assumed. */
- struct lttng_trigger *trigger;
- struct cds_list_head node;
-};
-
-struct lttng_channel_trigger_list {
- struct channel_key channel_key;
- /* List of struct lttng_trigger_list_element. */
- struct cds_list_head list;
- /* Node in the channel_triggers_ht */
- struct cds_lfht_node channel_triggers_ht_node;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
-/*
- * List of triggers applying to a given session.
- *
- * See:
- * - lttng_session_trigger_list_create()
- * - lttng_session_trigger_list_build()
- * - lttng_session_trigger_list_destroy()
- * - lttng_session_trigger_list_add()
- */
-struct lttng_session_trigger_list {
- /*
- * Not owned by this; points to the session_info structure's
- * session name.
- */
- const char *session_name;
- /* List of struct lttng_trigger_list_element. */
- struct cds_list_head list;
- /* Node in the session_triggers_ht */
- struct cds_lfht_node session_triggers_ht_node;
- /*
- * Weak reference to the notification system's session triggers
- * hashtable.
- *
- * The session trigger list structure structure is owned by
- * the session's session_info.
- *
- * The session_info is kept alive the the channel_infos holding a
- * reference to it (reference counting). When those channels are
- * destroyed (at runtime or on teardown), the reference they hold
- * to the session_info are released. On destruction of session_info,
- * session_info_destroy() will remove the list of triggers applying
- * to this session from the notification system's state.
- *
- * This implies that the session_triggers_ht must be destroyed
- * after the channels.
- */
- struct cds_lfht *session_triggers_ht;
- /* Used for delayed RCU reclaim. */
- struct rcu_head rcu_node;
-};
-
-struct lttng_trigger_ht_element {
- struct lttng_trigger *trigger;
- struct cds_lfht_node node;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
-struct lttng_condition_list_element {
- struct lttng_condition *condition;
- struct cds_list_head node;
-};
-
-struct channel_state_sample {
- struct channel_key key;
- struct cds_lfht_node channel_state_ht_node;
- uint64_t highest_usage;
- uint64_t lowest_usage;
- uint64_t channel_total_consumed;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
-static unsigned long hash_channel_key(struct channel_key *key);
-static int evaluate_buffer_condition(const struct lttng_condition *condition,
- struct lttng_evaluation **evaluation,
- const struct notification_thread_state *state,
- const struct channel_state_sample *previous_sample,
- const struct channel_state_sample *latest_sample,
- uint64_t previous_session_consumed_total,
- uint64_t latest_session_consumed_total,
- struct channel_info *channel_info);
-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);
-
-
-/* session_info API */
-static
-void session_info_destroy(void *_data);
-static
-void session_info_get(struct session_info *session_info);
-static
-void session_info_put(struct session_info *session_info);
-static
-struct session_info *session_info_create(const char *name,
- uid_t uid, gid_t gid,
- struct lttng_session_trigger_list *trigger_list,
- struct cds_lfht *sessions_ht);
-static
-void session_info_add_channel(struct session_info *session_info,
- struct channel_info *channel_info);
-static
-void session_info_remove_channel(struct session_info *session_info,
- struct channel_info *channel_info);
-
-/* lttng_session_trigger_list API */
-static
-struct lttng_session_trigger_list *lttng_session_trigger_list_create(
- const char *session_name,
- struct cds_lfht *session_triggers_ht);
-static
-struct lttng_session_trigger_list *lttng_session_trigger_list_build(
- const struct notification_thread_state *state,
- const char *session_name);
-static
-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,
- struct lttng_trigger *trigger);
-
-static
-int client_handle_transmission_status(
- struct notification_client *client,
- enum client_transmission_status transmission_status,
- struct notification_thread_state *state);
-
-static
-int match_client_socket(struct cds_lfht_node *node, const void *key)
-{
- /* This double-cast is intended to supress pointer-to-cast warning. */
- const int socket = (int) (intptr_t) key;
- const struct notification_client *client = caa_container_of(node,
- struct notification_client, client_socket_ht_node);
-
- return client->socket == socket;
-}
-
-static
-int match_client_id(struct cds_lfht_node *node, const void *key)
-{
- /* This double-cast is intended to supress pointer-to-cast warning. */
- const notification_client_id id = *((notification_client_id *) key);
- const struct notification_client *client = caa_container_of(
- node, struct notification_client, client_id_ht_node);
-
- return client->id == id;
-}
-
-static
-int match_channel_trigger_list(struct cds_lfht_node *node, const void *key)
-{
- struct channel_key *channel_key = (struct channel_key *) key;
- struct lttng_channel_trigger_list *trigger_list;
-
- trigger_list = caa_container_of(node, struct lttng_channel_trigger_list,
- channel_triggers_ht_node);
-
- return !!((channel_key->key == trigger_list->channel_key.key) &&
- (channel_key->domain == trigger_list->channel_key.domain));
-}
-
-static
-int match_session_trigger_list(struct cds_lfht_node *node, const void *key)
-{
- const char *session_name = (const char *) key;
- struct lttng_session_trigger_list *trigger_list;
-
- trigger_list = caa_container_of(node, struct lttng_session_trigger_list,
- session_triggers_ht_node);
-
- return !!(strcmp(trigger_list->session_name, session_name) == 0);
-}
-
-static
-int match_channel_state_sample(struct cds_lfht_node *node, const void *key)
-{
- struct channel_key *channel_key = (struct channel_key *) key;
- struct channel_state_sample *sample;
-
- sample = caa_container_of(node, struct channel_state_sample,
- channel_state_ht_node);
-
- return !!((channel_key->key == sample->key.key) &&
- (channel_key->domain == sample->key.domain));
-}
-
-static
-int match_channel_info(struct cds_lfht_node *node, const void *key)
-{
- struct channel_key *channel_key = (struct channel_key *) key;
- struct channel_info *channel_info;
-
- channel_info = caa_container_of(node, struct channel_info,
- channels_ht_node);
-
- return !!((channel_key->key == channel_info->key.key) &&
- (channel_key->domain == channel_info->key.domain));
-}
-
-static
-int match_condition(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;
-
- trigger = 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);
-}
-
-static
-int match_client_list_condition(struct cds_lfht_node *node, const void *key)
-{
- struct lttng_condition *condition_key = (struct lttng_condition *) key;
- struct notification_client_list *client_list;
- const struct lttng_condition *condition;
-
- assert(condition_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);
-
- return !!lttng_condition_is_equal(condition_key, condition);
-}
-
-static
-int match_session(struct cds_lfht_node *node, const void *key)
-{
- const char *name = key;
- struct session_info *session_info = caa_container_of(
- node, struct session_info, sessions_ht_node);
-
- return !strcmp(session_info->name, name);
-}
-
-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)
-{
- unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed);
- unsigned long domain_hash = hash_key_ulong(
- (void *) (unsigned long) key->domain, lttng_ht_seed);
-
- 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
- * object's state is updated.
- *
- * For instance, a condition bound to a channel will be evaluated everytime
- * the channel's state is changed by a channel monitoring sample.
- */
-static
-enum lttng_object_type get_condition_binding_object(
- const struct lttng_condition *condition)
-{
- switch (lttng_condition_get_type(condition)) {
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
- case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
- return LTTNG_OBJECT_TYPE_CHANNEL;
- case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
- case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
- return LTTNG_OBJECT_TYPE_SESSION;
- default:
- return LTTNG_OBJECT_TYPE_UNKNOWN;
- }
-}
-
-static
-void free_channel_info_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct channel_info, rcu_node));
-}
-
-static
-void channel_info_destroy(struct channel_info *channel_info)
-{
- if (!channel_info) {
- return;
- }
-
- if (channel_info->session_info) {
- session_info_remove_channel(channel_info->session_info,
- channel_info);
- session_info_put(channel_info->session_info);
- }
- if (channel_info->name) {
- free(channel_info->name);
- }
- call_rcu(&channel_info->rcu_node, free_channel_info_rcu);
-}
-
-static
-void free_session_info_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct session_info, rcu_node));
-}
-
-/* Don't call directly, use the ref-counting mechanism. */
-static
-void session_info_destroy(void *_data)
-{
- struct session_info *session_info = _data;
- int ret;
-
- assert(session_info);
- if (session_info->channel_infos_ht) {
- ret = cds_lfht_destroy(session_info->channel_infos_ht, NULL);
- if (ret) {
- ERR("[notification-thread] Failed to destroy channel information hash table");
- }
- }
- lttng_session_trigger_list_destroy(session_info->trigger_list);
-
- rcu_read_lock();
- cds_lfht_del(session_info->sessions_ht,
- &session_info->sessions_ht_node);
- rcu_read_unlock();
- free(session_info->name);
- call_rcu(&session_info->rcu_node, free_session_info_rcu);
-}
-
-static
-void session_info_get(struct session_info *session_info)
-{
- if (!session_info) {
- return;
- }
- lttng_ref_get(&session_info->ref);
-}
-
-static
-void session_info_put(struct session_info *session_info)
-{
- if (!session_info) {
- return;
- }
- lttng_ref_put(&session_info->ref);
-}
-
-static
-struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid,
- struct lttng_session_trigger_list *trigger_list,
- struct cds_lfht *sessions_ht)
-{
- struct session_info *session_info;
-
- assert(name);
-
- session_info = zmalloc(sizeof(*session_info));
- if (!session_info) {
- goto end;
- }
- lttng_ref_init(&session_info->ref, session_info_destroy);
-
- session_info->channel_infos_ht = cds_lfht_new(DEFAULT_HT_SIZE,
- 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
- if (!session_info->channel_infos_ht) {
- goto error;
- }
-
- cds_lfht_node_init(&session_info->sessions_ht_node);
- session_info->name = strdup(name);
- if (!session_info->name) {
- goto error;
- }
- session_info->uid = uid;
- session_info->gid = gid;
- session_info->trigger_list = trigger_list;
- session_info->sessions_ht = sessions_ht;
-end:
- return session_info;
-error:
- session_info_put(session_info);
- return NULL;
-}
-
-static
-void session_info_add_channel(struct session_info *session_info,
- struct channel_info *channel_info)
-{
- rcu_read_lock();
- cds_lfht_add(session_info->channel_infos_ht,
- hash_channel_key(&channel_info->key),
- &channel_info->session_info_channels_ht_node);
- rcu_read_unlock();
-}
-
-static
-void session_info_remove_channel(struct session_info *session_info,
- struct channel_info *channel_info)
-{
- rcu_read_lock();
- cds_lfht_del(session_info->channel_infos_ht,
- &channel_info->session_info_channels_ht_node);
- rcu_read_unlock();
-}
-
-static
-struct channel_info *channel_info_create(const char *channel_name,
- struct channel_key *channel_key, uint64_t channel_capacity,
- struct session_info *session_info)
-{
- struct channel_info *channel_info = zmalloc(sizeof(*channel_info));
-
- if (!channel_info) {
- goto end;
- }
-
- cds_lfht_node_init(&channel_info->channels_ht_node);
- cds_lfht_node_init(&channel_info->session_info_channels_ht_node);
- memcpy(&channel_info->key, channel_key, sizeof(*channel_key));
- channel_info->capacity = channel_capacity;
-
- channel_info->name = strdup(channel_name);
- if (!channel_info->name) {
- goto error;
- }
-
- /*
- * Set the references between session and channel infos:
- * - channel_info holds a strong reference to session_info
- * - session_info holds a weak reference to channel_info
- */
- session_info_get(session_info);
- session_info_add_channel(session_info, channel_info);
- channel_info->session_info = session_info;
-end:
- return channel_info;
-error:
- channel_info_destroy(channel_info);
- return NULL;
-}
-
-LTTNG_HIDDEN
-bool notification_client_list_get(struct notification_client_list *list)
-{
- return urcu_ref_get_unless_zero(&list->ref);
-}
-
-static
-void free_notification_client_list_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct notification_client_list,
- rcu_node));
-}
-
-static
-void notification_client_list_release(struct urcu_ref *list_ref)
-{
- struct notification_client_list *list =
- container_of(list_ref, typeof(*list), ref);
- struct notification_client_list_element *client_list_element, *tmp;
-
- if (list->notification_trigger_clients_ht) {
- rcu_read_lock();
- cds_lfht_del(list->notification_trigger_clients_ht,
- &list->notification_trigger_clients_ht_node);
- rcu_read_unlock();
- list->notification_trigger_clients_ht = NULL;
- }
- cds_list_for_each_entry_safe(client_list_element, tmp,
- &list->list, node) {
- free(client_list_element);
- }
- pthread_mutex_destroy(&list->lock);
- call_rcu(&list->rcu_node, free_notification_client_list_rcu);
-}
-
-static
-struct notification_client_list *notification_client_list_create(
- const struct lttng_trigger *trigger)
-{
- struct notification_client_list *client_list =
- zmalloc(sizeof(*client_list));
-
- if (!client_list) {
- goto error;
- }
- pthread_mutex_init(&client_list->lock, NULL);
- urcu_ref_init(&client_list->ref);
- cds_lfht_node_init(&client_list->notification_trigger_clients_ht_node);
- CDS_INIT_LIST_HEAD(&client_list->list);
- client_list->trigger = trigger;
-error:
- return client_list;
-}
-
-static
-void publish_notification_client_list(
- struct notification_thread_state *state,
- struct notification_client_list *list)
-{
- const struct lttng_condition *condition =
- lttng_trigger_get_const_condition(list->trigger);
-
- assert(!list->notification_trigger_clients_ht);
- notification_client_list_get(list);
-
- list->notification_trigger_clients_ht =
- state->notification_trigger_clients_ht;
-
- rcu_read_lock();
- cds_lfht_add(state->notification_trigger_clients_ht,
- lttng_condition_hash(condition),
- &list->notification_trigger_clients_ht_node);
- rcu_read_unlock();
-}
-
-LTTNG_HIDDEN
-void notification_client_list_put(struct notification_client_list *list)
-{
- if (!list) {
- return;
- }
- return urcu_ref_put(&list->ref, notification_client_list_release);
-}
-
-/* Provides a reference to the returned list. */
-static
-struct notification_client_list *get_client_list_from_condition(
- struct notification_thread_state *state,
- const struct lttng_condition *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);
- 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;
-}
-
-static
-int evaluate_channel_condition_for_client(
- const struct lttng_condition *condition,
- struct notification_thread_state *state,
- struct lttng_evaluation **evaluation,
- uid_t *session_uid, gid_t *session_gid)
-{
- int ret;
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
- struct channel_info *channel_info = NULL;
- struct channel_key *channel_key = NULL;
- 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) {
- struct lttng_trigger_list_element *element;
-
- cds_list_for_each_entry(element, &channel_trigger_list->list, node) {
- const struct lttng_condition *current_condition =
- lttng_trigger_get_const_condition(
- element->trigger);
-
- assert(current_condition);
- if (!lttng_condition_is_equal(condition,
- current_condition)) {
- continue;
- }
-
- /* Found the trigger, save the channel key. */
- channel_key = &channel_trigger_list->channel_key;
- break;
- }
- if (channel_key) {
- /* The channel key was found stop iteration. */
- break;
- }
- }
-
- if (!channel_key){
- /* No channel found; normal exit. */
- DBG("[notification-thread] No known channel associated with newly subscribed-to condition");
- ret = 0;
- goto end;
- }
-
- /* Fetch channel info for the matching channel. */
- cds_lfht_lookup(state->channels_ht,
- hash_channel_key(channel_key),
- match_channel_info,
- channel_key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
- channel_info = caa_container_of(node, struct channel_info,
- channels_ht_node);
-
- /* Retrieve the channel's last sample, if it exists. */
- cds_lfht_lookup(state->channel_state_ht,
- hash_channel_key(channel_key),
- match_channel_state_sample,
- channel_key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (node) {
- last_sample = caa_container_of(node,
- struct channel_state_sample,
- channel_state_ht_node);
- } else {
- /* Nothing to evaluate, no sample was ever taken. Normal exit */
- DBG("[notification-thread] No channel sample associated with newly subscribed-to condition");
- ret = 0;
- goto end;
- }
-
- ret = evaluate_buffer_condition(condition, evaluation, state,
- NULL, last_sample,
- 0, channel_info->session_info->consumed_data_size,
- channel_info);
- if (ret) {
- WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition");
- goto end;
- }
-
- *session_uid = channel_info->session_info->uid;
- *session_gid = channel_info->session_info->gid;
-end:
- rcu_read_unlock();
- return ret;
-}
-
-static
-const char *get_condition_session_name(const struct lttng_condition *condition)
-{
- const char *session_name = NULL;
- enum lttng_condition_status status;
-
- switch (lttng_condition_get_type(condition)) {
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
- status = lttng_condition_buffer_usage_get_session_name(
- condition, &session_name);
- break;
- case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
- status = lttng_condition_session_consumed_size_get_session_name(
- condition, &session_name);
- break;
- case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
- case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
- status = lttng_condition_session_rotation_get_session_name(
- condition, &session_name);
- break;
- default:
- abort();
- }
- if (status != LTTNG_CONDITION_STATUS_OK) {
- ERR("[notification-thread] Failed to retrieve session rotation condition's session name");
- goto end;
- }
-end:
- return session_name;
-}
-
-static
-int evaluate_session_condition_for_client(
- const struct lttng_condition *condition,
- struct notification_thread_state *state,
- struct lttng_evaluation **evaluation,
- uid_t *session_uid, gid_t *session_gid)
-{
- int ret;
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
- 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. */
- cds_lfht_lookup(state->sessions_ht,
- hash_key_str(session_name, lttng_ht_seed),
- match_session,
- session_name,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- DBG("[notification-thread] No known session matching name \"%s\"",
- session_name);
- ret = 0;
- goto end;
- }
-
- session_info = caa_container_of(node, struct session_info,
- sessions_ht_node);
- session_info_get(session_info);
-
- /*
- * Evaluation is performed in-line here since only one type of
- * session-bound condition is handled for the moment.
- */
- switch (lttng_condition_get_type(condition)) {
- case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
- if (!session_info->rotation.ongoing) {
- ret = 0;
- goto end_session_put;
- }
-
- *evaluation = lttng_evaluation_session_rotation_ongoing_create(
- session_info->rotation.id);
- if (!*evaluation) {
- /* Fatal error. */
- ERR("[notification-thread] Failed to create session rotation ongoing evaluation for session \"%s\"",
- session_info->name);
- ret = -1;
- goto end_session_put;
- }
- ret = 0;
- break;
- default:
- ret = 0;
- goto end_session_put;
- }
-
- *session_uid = session_info->uid;
- *session_gid = session_info->gid;
-
-end_session_put:
- session_info_put(session_info);
-end:
- rcu_read_unlock();
- return ret;
-}
-
-static
-int evaluate_condition_for_client(const struct lttng_trigger *trigger,
- const struct lttng_condition *condition,
- struct notification_client *client,
- struct notification_thread_state *state)
-{
- int ret;
- struct lttng_evaluation *evaluation = NULL;
- 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;
-
- assert(trigger);
- assert(condition);
- assert(client);
- assert(state);
-
- switch (get_condition_binding_object(condition)) {
- case LTTNG_OBJECT_TYPE_SESSION:
- ret = evaluate_session_condition_for_client(condition, state,
- &evaluation, &object_uid, &object_gid);
- break;
- case LTTNG_OBJECT_TYPE_CHANNEL:
- ret = evaluate_channel_condition_for_client(condition, state,
- &evaluation, &object_uid, &object_gid);
- break;
- case LTTNG_OBJECT_TYPE_NONE:
- ret = 0;
- goto end;
- case LTTNG_OBJECT_TYPE_UNKNOWN:
- default:
- ret = -1;
- goto end;
- }
- if (ret) {
- /* Fatal error. */
- goto end;
- }
- if (!evaluation) {
- /* Evaluation yielded nothing. Normal exit. */
- DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client");
- ret = 0;
- goto end;
- }
-
- /*
- * Create a temporary client list with the client currently
- * 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_element.node);
- client_list_element.client = client;
- cds_list_add(&client_list_element.node, &client_list.list);
-
- /* Send evaluation result to the newly-subscribed client. */
- DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client");
- ret = send_evaluation_to_clients(trigger, evaluation, &client_list,
- state, object_uid, object_gid);
-
-end:
- return ret;
-}
-
-static
-int notification_thread_client_subscribe(struct notification_client *client,
- struct lttng_condition *condition,
- struct notification_thread_state *state,
- enum lttng_notification_channel_status *_status)
-{
- int ret = 0;
- 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 =
- LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
-
- /*
- * Ensure that the client has not already subscribed to this condition
- * before.
- */
- cds_list_for_each_entry(condition_list_element, &client->condition_list, node) {
- if (lttng_condition_is_equal(condition_list_element->condition,
- condition)) {
- status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED;
- goto end;
- }
- }
-
- condition_list_element = zmalloc(sizeof(*condition_list_element));
- if (!condition_list_element) {
- ret = -1;
- goto error;
- }
- client_list_element = zmalloc(sizeof(*client_list_element));
- if (!client_list_element) {
- ret = -1;
- goto error;
- }
-
- /*
- * Add the newly-subscribed condition to the client's subscription list.
- */
- CDS_INIT_LIST_HEAD(&condition_list_element->node);
- condition_list_element->condition = condition;
- cds_list_add(&condition_list_element->node, &client->condition_list);
-
- client_list = get_client_list_from_condition(state, condition);
- if (!client_list) {
- /*
- * No notification-emiting trigger registered with this
- * condition. We don't evaluate the condition right away
- * since this trigger is not registered yet.
- */
- free(client_list_element);
- 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;
- }
-
- /*
- * Add the client to the list of clients interested in a given trigger
- * if a "notification" trigger with a corresponding condition was
- * added prior.
- */
- 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);
- 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);
- free(client_list_element);
- return ret;
-}
-
-static
-int notification_thread_client_unsubscribe(
- struct notification_client *client,
- struct lttng_condition *condition,
- struct notification_thread_state *state,
- enum lttng_notification_channel_status *_status)
-{
- struct notification_client_list *client_list;
- struct lttng_condition_list_element *condition_list_element,
- *condition_tmp;
- struct notification_client_list_element *client_list_element,
- *client_tmp;
- bool condition_found = false;
- enum lttng_notification_channel_status status =
- LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
-
- /* Remove the condition from the client's condition list. */
- cds_list_for_each_entry_safe(condition_list_element, condition_tmp,
- &client->condition_list, node) {
- if (!lttng_condition_is_equal(condition_list_element->condition,
- condition)) {
- continue;
- }
-
- cds_list_del(&condition_list_element->node);
- /*
- * The caller may be iterating on the client's conditions to
- * tear down a client's connection. In this case, the condition
- * will be destroyed at the end.
- */
- if (condition != condition_list_element->condition) {
- lttng_condition_destroy(
- condition_list_element->condition);
- }
- free(condition_list_element);
- condition_found = true;
- break;
- }
-
- if (!condition_found) {
- status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION;
- goto end;
- }
-
- /*
- * Remove the client from the list of clients interested the trigger
- * matching the condition.
- */
- client_list = get_client_list_from_condition(state, condition);
- if (!client_list) {
- 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->id != client->id) {
- continue;
- }
- cds_list_del(&client_list_element->node);
- free(client_list_element);
- break;
- }
- pthread_mutex_unlock(&client_list->lock);
- notification_client_list_put(client_list);
- client_list = NULL;
-end:
- lttng_condition_destroy(condition);
- if (_status) {
- *_status = status;
- }
- return 0;
-}
-
-static
-void free_notification_client_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct notification_client, rcu_node));
-}
-
-static
-void notification_client_destroy(struct notification_client *client,
- struct notification_thread_state *state)
-{
- if (!client) {
- return;
- }
-
- /*
- * 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_payload_reset(&client->communication.inbound.payload);
- lttng_payload_reset(&client->communication.outbound.payload);
- pthread_mutex_destroy(&client->lock);
- call_rcu(&client->rcu_node, free_notification_client_rcu);
-}
-
-/*
- * Call with rcu_read_lock held (and hold for the lifetime of the returned
- * client pointer).
- */
-static
-struct notification_client *get_client_from_socket(int socket,
- 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_socket_ht,
- hash_client_socket(socket),
- match_client_socket,
- (void *) (unsigned long) socket,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- goto end;
- }
-
- client = caa_container_of(node, struct notification_client,
- client_socket_ht_node);
-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,
- const struct channel_info *channel_info)
-{
- enum lttng_condition_status status;
- enum lttng_domain_type condition_domain;
- const char *condition_session_name = NULL;
- const char *condition_channel_name = NULL;
-
- status = lttng_condition_buffer_usage_get_domain_type(condition,
- &condition_domain);
- assert(status == LTTNG_CONDITION_STATUS_OK);
- if (channel_info->key.domain != condition_domain) {
- goto fail;
- }
-
- status = lttng_condition_buffer_usage_get_session_name(
- condition, &condition_session_name);
- assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name);
-
- status = lttng_condition_buffer_usage_get_channel_name(
- condition, &condition_channel_name);
- assert((status == LTTNG_CONDITION_STATUS_OK) && condition_channel_name);
-
- if (strcmp(channel_info->session_info->name, condition_session_name)) {
- goto fail;
- }
- if (strcmp(channel_info->name, condition_channel_name)) {
- goto fail;
- }
-
- return true;
-fail:
- return false;
-}
-
-static
-bool session_consumed_size_condition_applies_to_channel(
- const struct lttng_condition *condition,
- const struct channel_info *channel_info)
-{
- enum lttng_condition_status status;
- const char *condition_session_name = NULL;
-
- status = lttng_condition_session_consumed_size_get_session_name(
- condition, &condition_session_name);
- assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name);
-
- if (strcmp(channel_info->session_info->name, condition_session_name)) {
- goto fail;
- }
-
- return true;
-fail:
- return false;
-}
-
-static
-bool trigger_applies_to_channel(const struct lttng_trigger *trigger,
- const struct channel_info *channel_info)
-{
- const struct lttng_condition *condition;
- bool trigger_applies;
-
- condition = lttng_trigger_get_const_condition(trigger);
- if (!condition) {
- goto fail;
- }
-
- switch (lttng_condition_get_type(condition)) {
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
- trigger_applies = buffer_usage_condition_applies_to_channel(
- condition, channel_info);
- break;
- case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
- trigger_applies = session_consumed_size_condition_applies_to_channel(
- condition, channel_info);
- break;
- default:
- goto fail;
- }
-
- return trigger_applies;
-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(
- struct notification_thread_state *state,
- const char *session_name)
-{
- struct lttng_session_trigger_list *list = NULL;
- struct cds_lfht_node *node;
- struct cds_lfht_iter iter;
-
- cds_lfht_lookup(state->session_triggers_ht,
- hash_key_str(session_name, lttng_ht_seed),
- match_session_trigger_list,
- session_name,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- /*
- * Not an error, the list of triggers applying to that session
- * will be initialized when the session is created.
- */
- DBG("[notification-thread] No trigger list found for session \"%s\" as it is not yet known to the notification system",
- session_name);
- goto end;
- }
-
- list = caa_container_of(node,
- struct lttng_session_trigger_list,
- session_triggers_ht_node);
-end:
- return list;
-}
-
-/*
- * Allocate an empty lttng_session_trigger_list for the session named
- * 'session_name'.
- *
- * No ownership of 'session_name' is assumed by the session trigger list.
- * It is the caller's responsability to ensure the session name is alive
- * for as long as this list is.
- */
-static
-struct lttng_session_trigger_list *lttng_session_trigger_list_create(
- const char *session_name,
- struct cds_lfht *session_triggers_ht)
-{
- struct lttng_session_trigger_list *list;
-
- list = zmalloc(sizeof(*list));
- if (!list) {
- goto end;
- }
- list->session_name = session_name;
- CDS_INIT_LIST_HEAD(&list->list);
- cds_lfht_node_init(&list->session_triggers_ht_node);
- list->session_triggers_ht = session_triggers_ht;
-
- rcu_read_lock();
- /* Publish the list through the session_triggers_ht. */
- cds_lfht_add(session_triggers_ht,
- hash_key_str(session_name, lttng_ht_seed),
- &list->session_triggers_ht_node);
- rcu_read_unlock();
-end:
- return list;
-}
-
-static
-void free_session_trigger_list_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct lttng_session_trigger_list,
- rcu_node));
-}
-
-static
-void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list *list)
-{
- struct lttng_trigger_list_element *trigger_list_element, *tmp;
-
- /* Empty the list element by element, and then free the list itself. */
- cds_list_for_each_entry_safe(trigger_list_element, tmp,
- &list->list, node) {
- cds_list_del(&trigger_list_element->node);
- free(trigger_list_element);
- }
- rcu_read_lock();
- /* Unpublish the list from the session_triggers_ht. */
- cds_lfht_del(list->session_triggers_ht,
- &list->session_triggers_ht_node);
- rcu_read_unlock();
- call_rcu(&list->rcu_node, free_session_trigger_list_rcu);
-}
-
-static
-int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
- struct lttng_trigger *trigger)
-{
- int ret = 0;
- struct lttng_trigger_list_element *new_element =
- zmalloc(sizeof(*new_element));
-
- if (!new_element) {
- ret = -1;
- goto end;
- }
- CDS_INIT_LIST_HEAD(&new_element->node);
- new_element->trigger = trigger;
- cds_list_add(&new_element->node, &list->list);
-end:
- return ret;
-}
-
-static
-bool trigger_applies_to_session(const struct lttng_trigger *trigger,
- const char *session_name)
-{
- bool applies = false;
- const struct lttng_condition *condition;
-
- 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 condition_status;
- const char *condition_session_name;
-
- condition_status = lttng_condition_session_rotation_get_session_name(
- condition, &condition_session_name);
- if (condition_status != LTTNG_CONDITION_STATUS_OK) {
- ERR("[notification-thread] Failed to retrieve session rotation condition's session name");
- goto end;
- }
-
- assert(condition_session_name);
- applies = !strcmp(condition_session_name, session_name);
- break;
- }
- default:
- goto end;
- }
-end:
- return applies;
-}
-
-/*
- * Allocate and initialize an lttng_session_trigger_list which contains
- * all triggers that apply to the session named 'session_name'.
- *
- * No ownership of 'session_name' is assumed by the session trigger list.
- * It is the caller's responsability to ensure the session name is alive
- * for as long as this list is.
- */
-static
-struct lttng_session_trigger_list *lttng_session_trigger_list_build(
- const struct notification_thread_state *state,
- const char *session_name)
-{
- int trigger_count = 0;
- struct lttng_session_trigger_list *session_trigger_list = NULL;
- struct lttng_trigger_ht_element *trigger_ht_element = NULL;
- struct cds_lfht_iter iter;
-
- session_trigger_list = lttng_session_trigger_list_create(session_name,
- state->session_triggers_ht);
-
- /* Add all triggers applying to the session named 'session_name'. */
- cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
- node) {
- int ret;
-
- if (!trigger_applies_to_session(trigger_ht_element->trigger,
- session_name)) {
- continue;
- }
-
- ret = lttng_session_trigger_list_add(session_trigger_list,
- trigger_ht_element->trigger);
- if (ret) {
- goto error;
- }
-
- trigger_count++;
- }
-
- DBG("[notification-thread] Found %i triggers that apply to newly created session",
- trigger_count);
- return session_trigger_list;
-error:
- lttng_session_trigger_list_destroy(session_trigger_list);
- return NULL;
-}
-
-static
-struct session_info *find_or_create_session_info(
- struct notification_thread_state *state,
- const char *name, uid_t uid, gid_t gid)
-{
- struct session_info *session = NULL;
- struct cds_lfht_node *node;
- struct cds_lfht_iter iter;
- struct lttng_session_trigger_list *trigger_list;
-
- rcu_read_lock();
- cds_lfht_lookup(state->sessions_ht,
- hash_key_str(name, lttng_ht_seed),
- match_session,
- name,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (node) {
- DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)",
- name, uid, gid);
- session = caa_container_of(node, struct session_info,
- sessions_ht_node);
- assert(session->uid == uid);
- assert(session->gid == gid);
- session_info_get(session);
- goto end;
- }
-
- trigger_list = lttng_session_trigger_list_build(state, name);
- if (!trigger_list) {
- goto error;
- }
-
- session = session_info_create(name, uid, gid, trigger_list,
- state->sessions_ht);
- if (!session) {
- ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
- name, uid, gid);
- lttng_session_trigger_list_destroy(trigger_list);
- goto error;
- }
- trigger_list = NULL;
-
- cds_lfht_add(state->sessions_ht, hash_key_str(name, lttng_ht_seed),
- &session->sessions_ht_node);
-end:
- rcu_read_unlock();
- return session;
-error:
- rcu_read_unlock();
- session_info_put(session);
- return NULL;
-}
-
-static
-int handle_notification_thread_command_add_channel(
- struct notification_thread_state *state,
- const char *session_name, uid_t session_uid, gid_t session_gid,
- const char *channel_name, enum lttng_domain_type channel_domain,
- uint64_t channel_key_int, uint64_t channel_capacity,
- enum lttng_error_code *cmd_result)
-{
- struct cds_list_head trigger_list;
- struct channel_info *new_channel_info = NULL;
- struct channel_key channel_key = {
- .key = channel_key_int,
- .domain = channel_domain,
- };
- struct lttng_channel_trigger_list *channel_trigger_list = NULL;
- struct lttng_trigger_ht_element *trigger_ht_element = NULL;
- int trigger_count = 0;
- struct cds_lfht_iter iter;
- struct session_info *session_info = NULL;
-
- 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");
-
- CDS_INIT_LIST_HEAD(&trigger_list);
-
- session_info = find_or_create_session_info(state, session_name,
- session_uid, session_gid);
- if (!session_info) {
- /* Allocation error or an internal error occurred. */
- goto error;
- }
-
- new_channel_info = channel_info_create(channel_name, &channel_key,
- channel_capacity, session_info);
- if (!new_channel_info) {
- goto error;
- }
-
- rcu_read_lock();
- /* Build a list of all triggers applying to the new channel. */
- cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
- node) {
- struct lttng_trigger_list_element *new_element;
-
- if (!trigger_applies_to_channel(trigger_ht_element->trigger,
- new_channel_info)) {
- continue;
- }
-
- new_element = zmalloc(sizeof(*new_element));
- if (!new_element) {
- rcu_read_unlock();
- goto error;
- }
- CDS_INIT_LIST_HEAD(&new_element->node);
- new_element->trigger = trigger_ht_element->trigger;
- cds_list_add(&new_element->node, &trigger_list);
- trigger_count++;
- }
- rcu_read_unlock();
-
- DBG("[notification-thread] Found %i triggers that apply to newly added channel",
- trigger_count);
- channel_trigger_list = zmalloc(sizeof(*channel_trigger_list));
- if (!channel_trigger_list) {
- goto error;
- }
- channel_trigger_list->channel_key = new_channel_info->key;
- CDS_INIT_LIST_HEAD(&channel_trigger_list->list);
- cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node);
- cds_list_splice(&trigger_list, &channel_trigger_list->list);
-
- rcu_read_lock();
- /* Add channel to the channel_ht which owns the channel_infos. */
- cds_lfht_add(state->channels_ht,
- hash_channel_key(&new_channel_info->key),
- &new_channel_info->channels_ht_node);
- /*
- * Add the list of triggers associated with this channel to the
- * channel_triggers_ht.
- */
- cds_lfht_add(state->channel_triggers_ht,
- hash_channel_key(&new_channel_info->key),
- &channel_trigger_list->channel_triggers_ht_node);
- rcu_read_unlock();
- session_info_put(session_info);
- *cmd_result = LTTNG_OK;
- return 0;
-error:
- channel_info_destroy(new_channel_info);
- session_info_put(session_info);
- return 1;
-}
-
-static
-void free_channel_trigger_list_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct lttng_channel_trigger_list,
- rcu_node));
-}
-
-static
-void free_channel_state_sample_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct channel_state_sample,
- rcu_node));
-}
-
-static
-int handle_notification_thread_command_remove_channel(
- struct notification_thread_state *state,
- uint64_t channel_key, enum lttng_domain_type domain,
- enum lttng_error_code *cmd_result)
-{
- struct cds_lfht_node *node;
- struct cds_lfht_iter iter;
- struct lttng_channel_trigger_list *trigger_list;
- struct lttng_trigger_list_element *trigger_list_element, *tmp;
- struct channel_key key = { .key = channel_key, .domain = domain };
- struct channel_info *channel_info;
-
- DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain",
- channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space");
-
- rcu_read_lock();
-
- cds_lfht_lookup(state->channel_triggers_ht,
- hash_channel_key(&key),
- match_channel_trigger_list,
- &key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- /*
- * There is a severe internal error if we are being asked to remove a
- * channel that doesn't exist.
- */
- if (!node) {
- ERR("[notification-thread] Channel being removed is unknown to the notification thread");
- goto end;
- }
-
- /* Free the list of triggers associated with this channel. */
- trigger_list = caa_container_of(node, struct lttng_channel_trigger_list,
- channel_triggers_ht_node);
- cds_list_for_each_entry_safe(trigger_list_element, tmp,
- &trigger_list->list, node) {
- cds_list_del(&trigger_list_element->node);
- free(trigger_list_element);
- }
- cds_lfht_del(state->channel_triggers_ht, node);
- call_rcu(&trigger_list->rcu_node, free_channel_trigger_list_rcu);
-
- /* Free sampled channel state. */
- cds_lfht_lookup(state->channel_state_ht,
- hash_channel_key(&key),
- match_channel_state_sample,
- &key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- /*
- * This is expected to be NULL if the channel is destroyed before we
- * received a sample.
- */
- if (node) {
- struct channel_state_sample *sample = caa_container_of(node,
- struct channel_state_sample,
- channel_state_ht_node);
-
- cds_lfht_del(state->channel_state_ht, node);
- call_rcu(&sample->rcu_node, free_channel_state_sample_rcu);
- }
-
- /* Remove the channel from the channels_ht and free it. */
- cds_lfht_lookup(state->channels_ht,
- hash_channel_key(&key),
- match_channel_info,
- &key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- assert(node);
- channel_info = caa_container_of(node, struct channel_info,
- channels_ht_node);
- cds_lfht_del(state->channels_ht, node);
- channel_info_destroy(channel_info);
-end:
- rcu_read_unlock();
- *cmd_result = LTTNG_OK;
- return 0;
-}
-
-static
-int handle_notification_thread_command_session_rotation(
- struct notification_thread_state *state,
- enum notification_thread_command_type cmd_type,
- const char *session_name, uid_t session_uid, gid_t session_gid,
- uint64_t trace_archive_chunk_id,
- struct lttng_trace_archive_location *location,
- enum lttng_error_code *_cmd_result)
-{
- int ret = 0;
- enum lttng_error_code cmd_result = LTTNG_OK;
- struct lttng_session_trigger_list *trigger_list;
- struct lttng_trigger_list_element *trigger_list_element;
- struct session_info *session_info;
- const struct lttng_credentials session_creds = {
- .uid = session_uid,
- .gid = session_gid,
- };
-
- rcu_read_lock();
-
- session_info = find_or_create_session_info(state, session_name,
- session_uid, session_gid);
- if (!session_info) {
- /* Allocation error or an internal error occurred. */
- ret = -1;
- cmd_result = LTTNG_ERR_NOMEM;
- goto end;
- }
-
- session_info->rotation.ongoing =
- cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING;
- session_info->rotation.id = trace_archive_chunk_id;
- trigger_list = get_session_trigger_list(state, session_name);
- if (!trigger_list) {
- DBG("[notification-thread] No triggers applying to session \"%s\" found",
- session_name);
- goto end;
- }
-
- cds_list_for_each_entry(trigger_list_element, &trigger_list->list,
- node) {
- const struct lttng_condition *condition;
- struct lttng_trigger *trigger;
- struct notification_client_list *client_list;
- struct lttng_evaluation *evaluation = NULL;
- enum lttng_condition_type condition_type;
- enum action_executor_status executor_status;
-
- trigger = trigger_list_element->trigger;
- condition = lttng_trigger_get_const_condition(trigger);
- assert(condition);
- condition_type = lttng_condition_get_type(condition);
-
- if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING &&
- cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) {
- continue;
- } else if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED &&
- cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED) {
- continue;
- }
-
- client_list = get_client_list_from_condition(state, condition);
- if (cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) {
- evaluation = lttng_evaluation_session_rotation_ongoing_create(
- trace_archive_chunk_id);
- } else {
- evaluation = lttng_evaluation_session_rotation_completed_create(
- trace_archive_chunk_id, location);
- }
-
- if (!evaluation) {
- /* Internal error */
- ret = -1;
- cmd_result = LTTNG_ERR_UNK;
- goto put_list;
- }
-
- /*
- * Ownership of `evaluation` transferred to the action executor
- * no matter the result.
- */
- executor_status = action_executor_enqueue(state->executor,
- trigger, evaluation, &session_creds,
- client_list);
- evaluation = NULL;
- switch (executor_status) {
- case ACTION_EXECUTOR_STATUS_OK:
- break;
- case ACTION_EXECUTOR_STATUS_ERROR:
- case ACTION_EXECUTOR_STATUS_INVALID:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- */
- ERR("Fatal error occurred while enqueuing action associated with session rotation trigger");
- ret = -1;
- goto put_list;
- case ACTION_EXECUTOR_STATUS_OVERFLOW:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- *
- * Not a fatal error.
- */
- WARN("No space left when enqueuing action associated with session rotation trigger");
- ret = 0;
- goto put_list;
- default:
- abort();
- }
-
-put_list:
- notification_client_list_put(client_list);
- if (caa_unlikely(ret)) {
- break;
- }
- }
-end:
- session_info_put(session_info);
- *_cmd_result = cmd_result;
- rcu_read_unlock();
- 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;
- }
- default:
- ret = 1;
- }
-end:
- 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);
- 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,
- &lookup_iter);
- node = cds_lfht_iter_get_node(&lookup_iter);
- assert(node);
- trigger_list = caa_container_of(node,
- struct lttng_channel_trigger_list,
- channel_triggers_ht_node);
-
- trigger_list_element = zmalloc(sizeof(*trigger_list_element));
- if (!trigger_list_element) {
- ret = -1;
- goto end;
- }
- CDS_INIT_LIST_HEAD(&trigger_list_element->node);
- trigger_list_element->trigger = trigger;
- cds_list_add(&trigger_list_element->node, &trigger_list->list);
- DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"",
- channel->name);
- }
-end:
- return ret;
-}
-
-static
-bool is_trigger_action_notify(const struct lttng_trigger *trigger)
-{
- bool is_notify = false;
- unsigned int i, count;
- enum lttng_action_status action_status;
- const struct lttng_action *action =
- lttng_trigger_get_const_action(trigger);
- enum lttng_action_type action_type;
-
- assert(action);
- action_type = lttng_action_get_type_const(action);
- if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
- is_notify = true;
- goto end;
- } else if (action_type != LTTNG_ACTION_TYPE_GROUP) {
- goto end;
- }
-
- action_status = lttng_action_group_get_count(action, &count);
- assert(action_status == LTTNG_ACTION_STATUS_OK);
-
- for (i = 0; i < count; i++) {
- const struct lttng_action *inner_action =
- lttng_action_group_get_at_index(
- action, i);
-
- action_type = lttng_action_get_type_const(inner_action);
- if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
- is_notify = true;
- goto end;
- }
- }
-
-end:
- return is_notify;
-}
-
-/*
- * FIXME A client's credentials are not checked when registering a trigger.
- *
- * The effects of this are benign since:
- * - The client will succeed in registering the trigger, as it is valid,
- * - The trigger will, internally, be bound to the channel/session,
- * - The notifications will not be sent since the client's credentials
- * are checked against the channel at that moment.
- *
- * If this function returns a non-zero value, it means something is
- * fundamentally broken and the whole subsystem/thread will be torn down.
- *
- * If a non-fatal error occurs, just set the cmd_result to the appropriate
- * error code.
- */
-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;
- 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;
- bool free_trigger = true;
- struct lttng_evaluation *evaluation = NULL;
- struct lttng_credentials object_creds;
- enum action_executor_status executor_status;
-
- rcu_read_lock();
-
- 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.
- */
- if (is_trigger_action_notify(trigger)) {
- client_list = notification_client_list_create(trigger);
- 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;
- }
-
- 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);
- }
-
- 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;
- }
- break;
- case LTTNG_OBJECT_TYPE_CHANNEL:
- /*
- * Add the trigger to list of triggers bound to the channels
- * currently known.
- */
- ret = bind_trigger_to_matching_channels(trigger, state);
- if (ret) {
- goto error_put_client_list;
- }
- break;
- case LTTNG_OBJECT_TYPE_NONE:
- break;
- default:
- ERR("Unknown object type on which to bind a newly registered trigger was encountered");
- ret = -1;
- goto error_put_client_list;
- }
-
- /*
- * The new trigger's condition must be evaluated against the current
- * state.
- *
- * In the case of `notify` action, nothing preventing clients from
- * subscribing to a condition before the corresponding trigger is
- * registered, we have to evaluate this new condition right away.
- *
- * At some point, we were waiting for the next "evaluation" (e.g. on
- * reception of a channel sample) to evaluate this new condition, but
- * that was broken.
- *
- * The reason it was broken is that waiting for the next sample
- * does not allow us to properly handle transitions for edge-triggered
- * conditions.
- *
- * Consider this example: when we handle a new channel sample, we
- * evaluate each conditions twice: once with the previous state, and
- * again with the newest state. We then use those two results to
- * determine whether a state change happened: a condition was false and
- * became true. If a state change happened, we have to notify clients.
- *
- * Now, if a client subscribes to a given notification and registers
- * a trigger *after* that subscription, we have to make sure the
- * condition is evaluated at this point while considering only the
- * 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.
- */
- 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);
- break;
- case LTTNG_OBJECT_TYPE_CHANNEL:
- ret = evaluate_channel_condition_for_client(condition, state,
- &evaluation, &object_creds.uid,
- &object_creds.gid);
- break;
- case LTTNG_OBJECT_TYPE_NONE:
- ret = 0;
- goto error_put_client_list;
- case LTTNG_OBJECT_TYPE_UNKNOWN:
- default:
- ret = -1;
- goto error_put_client_list;
- }
-
- if (ret) {
- /* Fatal error. */
- goto error_put_client_list;
- }
-
- 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;
- }
-
- /*
- * Ownership of `evaluation` transferred to the action executor
- * no matter the result.
- */
- executor_status = action_executor_enqueue(state->executor, trigger,
- evaluation, &object_creds, client_list);
- evaluation = NULL;
- switch (executor_status) {
- case ACTION_EXECUTOR_STATUS_OK:
- break;
- case ACTION_EXECUTOR_STATUS_ERROR:
- case ACTION_EXECUTOR_STATUS_INVALID:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- */
- ERR("Fatal error occurred while enqueuing action associated to newly registered trigger");
- ret = -1;
- goto error_put_client_list;
- case ACTION_EXECUTOR_STATUS_OVERFLOW:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- *
- * Not a fatal error.
- */
- WARN("No space left when enqueuing action associated to newly registered trigger");
- ret = 0;
- goto error_put_client_list;
- default:
- abort();
- }
-
- *cmd_result = LTTNG_OK;
-
-error_put_client_list:
- notification_client_list_put(client_list);
-
-error_free_ht_element:
- free(trigger_ht_element);
-error:
- if (free_trigger) {
- lttng_trigger_destroy(trigger);
- }
- rcu_read_unlock();
- return ret;
-}
-
-static
-void free_lttng_trigger_ht_element_rcu(struct rcu_head *node)
-{
- free(caa_container_of(node, struct lttng_trigger_ht_element,
- rcu_node));
-}
-
-static
-int handle_notification_thread_command_unregister_trigger(
- struct notification_thread_state *state,
- struct lttng_trigger *trigger,
- enum lttng_error_code *_cmd_reply)
-{
- struct cds_lfht_iter iter;
- struct cds_lfht_node *triggers_ht_node;
- 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(
- trigger);
- enum lttng_error_code cmd_reply;
-
- rcu_read_lock();
-
- cds_lfht_lookup(state->triggers_ht,
- lttng_condition_hash(condition),
- match_condition,
- condition,
- &iter);
- triggers_ht_node = cds_lfht_iter_get_node(&iter);
- if (!triggers_ht_node) {
- cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND;
- goto end;
- } else {
- cmd_reply = LTTNG_OK;
- }
-
- /* Remove trigger from channel_triggers_ht. */
- cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list,
- channel_triggers_ht_node) {
- struct lttng_trigger_list_element *trigger_element, *tmp;
-
- 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)) {
- continue;
- }
-
- DBG("[notification-thread] Removed trigger from channel_triggers_ht");
- cds_list_del(&trigger_element->node);
- /* A trigger can only appear once per channel */
- break;
- }
- }
-
- /*
- * 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;
-
- /* 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_ht, triggers_ht_node);
-
- /* 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:
- rcu_read_unlock();
- if (_cmd_reply) {
- *_cmd_reply = cmd_reply;
- }
- return 0;
-}
-
-/* Returns 0 on success, 1 on exit requested, negative value on error. */
-int handle_notification_thread_command(
- struct notification_thread_handle *handle,
- struct notification_thread_state *state)
-{
- int ret;
- uint64_t counter;
- struct notification_thread_command *cmd;
-
- /* Read the event pipe to put it back into a quiescent state. */
- ret = lttng_read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter,
- sizeof(counter));
- if (ret != sizeof(counter)) {
- goto error;
- }
-
- pthread_mutex_lock(&handle->cmd_queue.lock);
- cmd = cds_list_first_entry(&handle->cmd_queue.list,
- struct notification_thread_command, cmd_list_node);
- cds_list_del(&cmd->cmd_list_node);
- pthread_mutex_unlock(&handle->cmd_queue.lock);
- switch (cmd->type) {
- case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER:
- DBG("[notification-thread] Received register trigger command");
- ret = handle_notification_thread_command_register_trigger(
- state, cmd->parameters.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,
- &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,
- cmd->parameters.add_channel.session.uid,
- cmd->parameters.add_channel.session.gid,
- cmd->parameters.add_channel.channel.name,
- cmd->parameters.add_channel.channel.domain,
- cmd->parameters.add_channel.channel.key,
- cmd->parameters.add_channel.channel.capacity,
- &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,
- &cmd->reply_code);
- 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,
- cmd->parameters.session_rotation.session_name,
- cmd->parameters.session_rotation.uid,
- cmd->parameters.session_rotation.gid,
- cmd->parameters.session_rotation.trace_archive_chunk_id,
- cmd->parameters.session_rotation.location,
- &cmd->reply_code);
- break;
- case NOTIFICATION_COMMAND_TYPE_QUIT:
- DBG("[notification-thread] Received quit command");
- cmd->reply_code = LTTNG_OK;
- ret = 1;
- goto end;
- case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE:
- {
- const enum client_transmission_status client_status =
- cmd->parameters.client_communication_update
- .status;
- const notification_client_id client_id =
- cmd->parameters.client_communication_update.id;
- struct notification_client *client;
-
- rcu_read_lock();
- client = get_client_from_id(client_id, state);
-
- if (!client) {
- /*
- * Client error was probably already picked-up by the
- * notification thread or it has disconnected
- * gracefully while this command was queued.
- */
- DBG("Failed to find notification client to update communication status, client id = %" PRIu64,
- client_id);
- ret = 0;
- } else {
- ret = client_handle_transmission_status(
- client, client_status, state);
- }
- rcu_read_unlock();
- break;
- }
- default:
- ERR("[notification-thread] Unknown internal command received");
- goto error_unlock;
- }
-
- if (ret) {
- goto error_unlock;
- }
-end:
- if (cmd->is_async) {
- free(cmd);
- cmd = NULL;
- } else {
- lttng_waiter_wake_up(&cmd->reply_waiter);
- }
- return ret;
-error_unlock:
- /* Wake-up and return a fatal error to the calling thread. */
- lttng_waiter_wake_up(&cmd->reply_waiter);
- cmd->reply_code = LTTNG_ERR_FATAL;
-error:
- /* Indicate a fatal error to the caller. */
- return -1;
-}
-
-static
-int socket_set_non_blocking(int socket)
-{
- int ret, flags;
-
- /* Set the pipe as non-blocking. */
- ret = fcntl(socket, F_GETFL, 0);
- if (ret == -1) {
- PERROR("fcntl get socket flags");
- goto end;
- }
- flags = ret;
-
- ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK);
- if (ret == -1) {
- PERROR("fcntl set O_NONBLOCK socket flag");
- goto end;
- }
- DBG("Client socket (fd = %i) set as non-blocking", socket);
-end:
- return ret;
-}
-
-static
-int client_reset_inbound_state(struct notification_client *client)
-{
- int ret;
-
-
- lttng_payload_clear(&client->communication.inbound.payload);
-
- client->communication.inbound.bytes_to_receive =
- sizeof(struct lttng_notification_channel_message);
- client->communication.inbound.msg_type =
- LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN;
- LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1);
- LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1);
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.inbound.payload.buffer,
- client->communication.inbound.bytes_to_receive);
-
- return ret;
-}
-
-int handle_notification_thread_client_connect(
- struct notification_thread_state *state)
-{
- int ret;
- struct notification_client *client;
-
- DBG("[notification-thread] Handling new notification channel client connection");
-
- client = zmalloc(sizeof(*client));
- if (!client) {
- /* Fatal error. */
- 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_payload_init(&client->communication.inbound.payload);
- lttng_payload_init(&client->communication.outbound.payload);
- client->communication.inbound.expect_creds = true;
-
- ret = client_reset_inbound_state(client);
- if (ret) {
- ERR("[notification-thread] Failed to reset client communication's inbound state");
- ret = 0;
- goto error;
- }
-
- ret = lttcomm_accept_unix_sock(state->notification_channel_socket);
- if (ret < 0) {
- ERR("[notification-thread] Failed to accept new notification channel client connection");
- ret = 0;
- goto error;
- }
-
- client->socket = ret;
-
- ret = socket_set_non_blocking(client->socket);
- if (ret) {
- ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking");
- goto error;
- }
-
- ret = lttcomm_setsockopt_creds_unix_sock(client->socket);
- if (ret < 0) {
- ERR("[notification-thread] Failed to set socket options on new notification channel client socket");
- ret = 0;
- goto error;
- }
-
- ret = lttng_poll_add(&state->events, client->socket,
- LPOLLIN | LPOLLERR |
- LPOLLHUP | LPOLLRDHUP);
- if (ret < 0) {
- ERR("[notification-thread] Failed to add notification channel client socket to poll set");
- ret = 0;
- goto error;
- }
- DBG("[notification-thread] Added new notification channel client socket (%i) to poll set",
- client->socket);
-
- rcu_read_lock();
- cds_lfht_add(state->client_socket_ht,
- hash_client_socket(client->socket),
- &client->client_socket_ht_node);
- cds_lfht_add(state->client_id_ht,
- hash_client_id(client->id),
- &client->client_id_ht_node);
- rcu_read_unlock();
-
- return ret;
-
-error:
- notification_client_destroy(client, state);
- return ret;
-}
-
-/*
- * RCU read-lock must be held by the caller.
- * Client lock must _not_ be held by the caller.
- */
-static
-int notification_thread_client_disconnect(
- struct notification_client *client,
- struct notification_thread_state *state)
-{
- int ret;
- struct lttng_condition_list_element *condition_list_element, *tmp;
-
- /* Acquire the client lock to disable its communication atomically. */
- pthread_mutex_lock(&client->lock);
- client->communication.active = false;
- cds_lfht_del(state->client_socket_ht, &client->client_socket_ht_node);
- cds_lfht_del(state->client_id_ht, &client->client_id_ht_node);
- pthread_mutex_unlock(&client->lock);
-
- ret = lttng_poll_del(&state->events, client->socket);
- if (ret) {
- ERR("[notification-thread] Failed to remove client socket %d from poll set",
- client->socket);
- }
-
- /* Release all conditions to which the client was subscribed. */
- cds_list_for_each_entry_safe(condition_list_element, tmp,
- &client->condition_list, node) {
- (void) notification_thread_client_unsubscribe(client,
- condition_list_element->condition, state, NULL);
- }
-
- /*
- * Client no longer accessible to other threads (through the
- * client lists).
- */
- notification_client_destroy(client, state);
- return ret;
-}
-
-int handle_notification_thread_client_disconnect(
- int client_socket, struct notification_thread_state *state)
-{
- int ret = 0;
- struct notification_client *client;
-
- rcu_read_lock();
- DBG("[notification-thread] Closing client connection (socket fd = %i)",
- client_socket);
- client = get_client_from_socket(client_socket, state);
- if (!client) {
- /* Internal state corruption, fatal error. */
- ERR("[notification-thread] Unable to find client (socket fd = %i)",
- client_socket);
- ret = -1;
- goto end;
- }
-
- ret = notification_thread_client_disconnect(client, state);
-end:
- rcu_read_unlock();
- return ret;
-}
-
-int handle_notification_thread_client_disconnect_all(
- struct notification_thread_state *state)
-{
- struct cds_lfht_iter iter;
- struct notification_client *client;
- bool error_encoutered = false;
-
- 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) {
- int ret;
-
- ret = notification_thread_client_disconnect(
- client, state);
- if (ret) {
- error_encoutered = true;
- }
- }
- rcu_read_unlock();
- return error_encoutered ? 1 : 0;
-}
-
-int handle_notification_thread_trigger_unregister_all(
- struct notification_thread_state *state)
-{
- bool error_occurred = false;
- struct cds_lfht_iter iter;
- struct lttng_trigger_ht_element *trigger_ht_element;
-
- rcu_read_lock();
- cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
- node) {
- int ret = handle_notification_thread_command_unregister_trigger(
- state, trigger_ht_element->trigger, NULL);
- if (ret) {
- error_occurred = true;
- }
- }
- rcu_read_unlock();
- return error_occurred ? -1 : 0;
-}
-
-static
-int client_handle_transmission_status(
- struct notification_client *client,
- enum client_transmission_status transmission_status,
- struct notification_thread_state *state)
-{
- int ret = 0;
-
- switch (transmission_status) {
- case CLIENT_TRANSMISSION_STATUS_COMPLETE:
- ret = lttng_poll_mod(&state->events, client->socket,
- CLIENT_POLL_MASK_IN);
- if (ret) {
- goto end;
- }
-
- break;
- case CLIENT_TRANSMISSION_STATUS_QUEUED:
- /*
- * We want to be notified whenever there is buffer space
- * available to send the rest of the payload.
- */
- ret = lttng_poll_mod(&state->events, client->socket,
- CLIENT_POLL_MASK_IN_OUT);
- if (ret) {
- goto end;
- }
- break;
- case CLIENT_TRANSMISSION_STATUS_FAIL:
- ret = notification_thread_client_disconnect(client, state);
- if (ret) {
- goto end;
- }
- break;
- case CLIENT_TRANSMISSION_STATUS_ERROR:
- ret = -1;
- goto end;
- default:
- abort();
- }
-end:
- return ret;
-}
-
-/* Client lock must be acquired by caller. */
-static
-enum client_transmission_status client_flush_outgoing_queue(
- struct notification_client *client)
-{
- ssize_t ret;
- size_t to_send_count;
- enum client_transmission_status status;
- struct lttng_payload_view pv = lttng_payload_view_from_payload(
- &client->communication.outbound.payload, 0, -1);
- const int fds_to_send_count =
- lttng_payload_view_get_fd_handle_count(&pv);
-
- ASSERT_LOCKED(client->lock);
-
- if (!client->communication.active) {
- status = CLIENT_TRANSMISSION_STATUS_FAIL;
- goto end;
- }
-
- if (pv.buffer.size == 0) {
- /*
- * If both data and fds are equal to zero, we are in an invalid
- * state.
- */
- assert(fds_to_send_count != 0);
- goto send_fds;
- }
-
- /* Send data. */
- to_send_count = pv.buffer.size;
- DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue",
- client->socket);
-
- ret = lttcomm_send_unix_sock_non_block(client->socket,
- pv.buffer.data,
- to_send_count);
- if ((ret >= 0 && ret < to_send_count)) {
- DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed",
- client->socket);
- to_send_count -= max(ret, 0);
-
- memcpy(client->communication.outbound.payload.buffer.data,
- pv.buffer.data +
- pv.buffer.size - to_send_count,
- to_send_count);
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.outbound.payload.buffer,
- to_send_count);
- if (ret) {
- goto error;
- }
-
- status = CLIENT_TRANSMISSION_STATUS_QUEUED;
- goto end;
- } else if (ret < 0) {
- /* Generic error, disable the client's communication. */
- ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)",
- client->socket);
- client->communication.active = false;
- status = CLIENT_TRANSMISSION_STATUS_FAIL;
- goto end;
- } else {
- /*
- * No error and flushed the queue completely.
- *
- * The payload buffer size is used later to
- * check if there is notifications queued. So albeit that the
- * direct caller knows that the transmission is complete, we
- * need to set the buffer size to zero.
- */
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.outbound.payload.buffer, 0);
- if (ret) {
- goto error;
- }
- }
-
-send_fds:
- /* No fds to send, transmission is complete. */
- if (fds_to_send_count == 0) {
- status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
- goto end;
- }
-
- ret = lttcomm_send_payload_view_fds_unix_sock_non_block(
- client->socket, &pv);
- if (ret < 0) {
- /* Generic error, disable the client's communication. */
- ERR("[notification-thread] Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)",
- client->socket);
- client->communication.active = false;
- status = CLIENT_TRANSMISSION_STATUS_FAIL;
- goto end;
- } else if (ret == 0) {
- /* Nothing could be sent. */
- status = CLIENT_TRANSMISSION_STATUS_QUEUED;
- } else {
- /* Fd passing is an all or nothing kind of thing. */
- status = CLIENT_TRANSMISSION_STATUS_COMPLETE;
- /*
- * The payload _fd_array count is used later to
- * check if there is notifications queued. So although the
- * direct caller knows that the transmission is complete, we
- * need to clear the _fd_array for the queuing check.
- */
- lttng_dynamic_pointer_array_clear(
- &client->communication.outbound.payload
- ._fd_handles);
- }
-
-end:
- if (status == CLIENT_TRANSMISSION_STATUS_COMPLETE) {
- client->communication.outbound.queued_command_reply = false;
- client->communication.outbound.dropped_notification = false;
- lttng_payload_clear(&client->communication.outbound.payload);
- }
-
- return status;
-error:
- return CLIENT_TRANSMISSION_STATUS_ERROR;
-}
-
-static
-bool client_has_outbound_data_left(
- const struct notification_client *client)
-{
- const struct lttng_payload_view pv = lttng_payload_view_from_payload(
- &client->communication.outbound.payload, 0, -1);
- const bool has_data = pv.buffer.size != 0;
- const bool has_fds = lttng_payload_view_get_fd_handle_count(&pv);
-
- return has_data || has_fds;
-}
-
-/* Client lock must _not_ be held by the caller. */
-static
-int client_send_command_reply(struct notification_client *client,
- struct notification_thread_state *state,
- enum lttng_notification_channel_status status)
-{
- int ret;
- struct lttng_notification_channel_command_reply reply = {
- .status = (int8_t) status,
- };
- struct lttng_notification_channel_message msg = {
- .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY,
- .size = sizeof(reply),
- };
- char buffer[sizeof(msg) + sizeof(reply)];
- enum client_transmission_status transmission_status;
-
- memcpy(buffer, &msg, sizeof(msg));
- memcpy(buffer + sizeof(msg), &reply, sizeof(reply));
- DBG("[notification-thread] Send command reply (%i)", (int) status);
-
- pthread_mutex_lock(&client->lock);
- if (client->communication.outbound.queued_command_reply) {
- /* Protocol error. */
- goto error_unlock;
- }
-
- /* Enqueue buffer to outgoing queue and flush it. */
- ret = lttng_dynamic_buffer_append(
- &client->communication.outbound.payload.buffer,
- buffer, sizeof(buffer));
- if (ret) {
- goto error_unlock;
- }
-
- transmission_status = client_flush_outgoing_queue(client);
-
- if (client_has_outbound_data_left(client)) {
- /* Queue could not be emptied. */
- client->communication.outbound.queued_command_reply = true;
- }
-
- pthread_mutex_unlock(&client->lock);
- ret = client_handle_transmission_status(
- client, transmission_status, state);
- if (ret) {
- goto error;
- }
-
- return 0;
-error_unlock:
- pthread_mutex_unlock(&client->lock);
-error:
- return -1;
-}
-
-static
-int client_handle_message_unknown(struct notification_client *client,
- struct notification_thread_state *state)
-{
- int ret;
- /*
- * Receiving message header. The function will be called again
- * once the rest of the message as been received and can be
- * interpreted.
- */
- const struct lttng_notification_channel_message *msg;
-
- assert(sizeof(*msg) == client->communication.inbound.payload.buffer.size);
- msg = (const struct lttng_notification_channel_message *)
- client->communication.inbound.payload.buffer.data;
-
- if (msg->size == 0 ||
- msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) {
- ERR("[notification-thread] Invalid notification channel message: length = %u",
- msg->size);
- ret = -1;
- goto end;
- }
-
- switch (msg->type) {
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE:
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE:
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE:
- break;
- default:
- ret = -1;
- ERR("[notification-thread] Invalid notification channel message: unexpected message type");
- goto end;
- }
-
- client->communication.inbound.bytes_to_receive = msg->size;
- client->communication.inbound.fds_to_receive = msg->fds;
- client->communication.inbound.msg_type =
- (enum lttng_notification_channel_message_type) msg->type;
- ret = lttng_dynamic_buffer_set_size(
- &client->communication.inbound.payload.buffer, msg->size);
-
- /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */
- msg = NULL;
-end:
- return ret;
-}
-
-static
-int client_handle_message_handshake(struct notification_client *client,
- struct notification_thread_state *state)
-{
- int ret;
- struct lttng_notification_channel_command_handshake *handshake_client;
- const struct lttng_notification_channel_command_handshake handshake_reply = {
- .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR,
- .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR,
- };
- const struct lttng_notification_channel_message msg_header = {
- .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE,
- .size = sizeof(handshake_reply),
- };
- enum lttng_notification_channel_status status =
- LTTNG_NOTIFICATION_CHANNEL_STATUS_OK;
- char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)];
-
- memcpy(send_buffer, &msg_header, sizeof(msg_header));
- memcpy(send_buffer + sizeof(msg_header), &handshake_reply,
- sizeof(handshake_reply));
-
- handshake_client =
- (struct lttng_notification_channel_command_handshake *)
- client->communication.inbound.payload.buffer
- .data;
- client->major = handshake_client->major;
- client->minor = handshake_client->minor;
- if (!client->communication.inbound.creds_received) {
- ERR("[notification-thread] No credentials received from client");
- ret = -1;
- goto end;
- }
-
- client->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;
- }
-
- pthread_mutex_lock(&client->lock);
- /* Outgoing queue will be flushed when the command reply is sent. */
- ret = lttng_dynamic_buffer_append(
- &client->communication.outbound.payload.buffer, send_buffer,
- sizeof(send_buffer));
- if (ret) {
- ERR("[notification-thread] Failed to send protocol version to notification channel client");
- goto end_unlock;
- }
-
- client->validated = true;
- client->communication.active = true;
- pthread_mutex_unlock(&client->lock);
-
- /* Set reception state to receive the next message header. */
- ret = client_reset_inbound_state(client);
- if (ret) {
- ERR("[notification-thread] Failed to reset client communication's inbound state");
- goto end;
- }
-
- /* Flushes the outgoing queue. */
- ret = client_send_command_reply(client, state, status);
- if (ret) {
- ERR("[notification-thread] Failed to send reply to notification channel client");
- goto end;
- }
-
- goto end;
-end_unlock:
- pthread_mutex_unlock(&client->lock);
-end:
- return ret;
-}
-
-static
-int client_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;
- struct lttng_payload_view condition_view =
- lttng_payload_view_from_payload(
- &client->communication.inbound.payload,
- 0, -1);
- size_t expected_condition_size;
-
- /*
- * No need to lock client to sample the inbound state as the only
- * other thread accessing clients (action executor) only uses the
- * outbound state.
- */
- expected_condition_size = client->communication.inbound.payload.buffer.size;
- ret = lttng_condition_create_from_payload(&condition_view, &condition);
- if (ret != expected_condition_size) {
- ERR("[notification-thread] Malformed condition received from client");
- goto end;
- }
-
- 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;
- }
-
- /* 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_send_command_reply(client, state, status);
- if (ret) {
- ERR("[notification-thread] Failed to send reply to notification channel client");
- goto end;
- }
-
-end:
- return ret;
-}
-
-static
-int client_dispatch_message(struct notification_client *client,
- struct notification_thread_state *state)
-{
- int ret = 0;
-
- if (client->communication.inbound.msg_type !=
- LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE &&
- client->communication.inbound.msg_type !=
- LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN &&
- !client->validated) {
- WARN("[notification-thread] client attempted a command before handshake");
- ret = -1;
- goto end;
- }
-
- switch (client->communication.inbound.msg_type) {
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN:
- {
- ret = client_handle_message_unknown(client, state);
- break;
- }
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE:
- {
- ret = client_handle_message_handshake(client, state);
- break;
- }
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE:
- case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE:
- {
- ret = client_handle_message_subscription(client,
- client->communication.inbound.msg_type, state);
- break;
- }
- default:
- abort();
- }
-end:
- return ret;
-}
-
-/* Incoming data from client. */
-int handle_notification_thread_client_in(
- struct notification_thread_state *state, int socket)
-{
- int ret = 0;
- struct notification_client *client;
- ssize_t recv_ret;
- size_t offset;
-
- rcu_read_lock();
- client = get_client_from_socket(socket, state);
- if (!client) {
- /* Internal error, abort. */
- ret = -1;
- goto end;
- }
-
- offset = client->communication.inbound.payload.buffer.size -
- client->communication.inbound.bytes_to_receive;
- if (client->communication.inbound.expect_creds) {
- recv_ret = lttcomm_recv_creds_unix_sock(socket,
- client->communication.inbound.payload.buffer.data + offset,
- client->communication.inbound.bytes_to_receive,
- &client->communication.inbound.creds);
- if (recv_ret > 0) {
- client->communication.inbound.expect_creds = false;
- client->communication.inbound.creds_received = true;
- }
- } else {
- recv_ret = lttcomm_recv_unix_sock_non_block(socket,
- client->communication.inbound.payload.buffer.data + offset,
- client->communication.inbound.bytes_to_receive);
- }
- if (recv_ret >= 0) {
- client->communication.inbound.bytes_to_receive -= recv_ret;
- } else {
- goto error_disconnect_client;
- }
-
- if (client->communication.inbound.bytes_to_receive != 0) {
- /* Message incomplete wait for more data. */
- ret = 0;
- goto end;
- }
-
- assert(client->communication.inbound.bytes_to_receive == 0);
-
- /* Receive fds. */
- if (client->communication.inbound.fds_to_receive != 0) {
- ret = lttcomm_recv_payload_fds_unix_sock_non_block(
- client->socket,
- client->communication.inbound.fds_to_receive,
- &client->communication.inbound.payload);
- if (ret > 0) {
- /*
- * Fds received. non blocking fds passing is all
- * or nothing.
- */
- ssize_t expected_size;
-
- expected_size = sizeof(int) *
- client->communication.inbound
- .fds_to_receive;
- assert(ret == expected_size);
- client->communication.inbound.fds_to_receive = 0;
- } else if (ret == 0) {
- /* Received nothing. */
- ret = 0;
- goto end;
- } else {
- goto error_disconnect_client;
- }
- }
-
- /* At this point the message is complete.*/
- assert(client->communication.inbound.bytes_to_receive == 0 &&
- client->communication.inbound.fds_to_receive == 0);
- ret = client_dispatch_message(client, state);
- if (ret) {
- /*
- * Only returns an error if this client must be
- * disconnected.
- */
- goto error_disconnect_client;
- }
-
-end:
- rcu_read_unlock();
- return ret;
-
-error_disconnect_client:
- ret = notification_thread_client_disconnect(client, state);
- goto end;
-}
-
-/* Client ready to receive outgoing data. */
-int handle_notification_thread_client_out(
- struct notification_thread_state *state, int socket)
-{
- int ret;
- struct notification_client *client;
- enum client_transmission_status transmission_status;
-
- rcu_read_lock();
- client = get_client_from_socket(socket, state);
- if (!client) {
- /* Internal error, abort. */
- ret = -1;
- goto end;
- }
-
- pthread_mutex_lock(&client->lock);
- transmission_status = client_flush_outgoing_queue(client);
- pthread_mutex_unlock(&client->lock);
-
- ret = client_handle_transmission_status(
- client, transmission_status, state);
- if (ret) {
- goto end;
- }
-end:
- rcu_read_unlock();
- return ret;
-}
-
-static
-bool evaluate_buffer_usage_condition(const struct lttng_condition *condition,
- const struct channel_state_sample *sample,
- uint64_t buffer_capacity)
-{
- bool result = false;
- uint64_t threshold;
- enum lttng_condition_type condition_type;
- const struct lttng_condition_buffer_usage *use_condition = container_of(
- condition, struct lttng_condition_buffer_usage,
- parent);
-
- if (use_condition->threshold_bytes.set) {
- threshold = use_condition->threshold_bytes.value;
- } else {
- /*
- * Threshold was expressed as a ratio.
- *
- * TODO the threshold (in bytes) of conditions expressed
- * as a ratio of total buffer size could be cached to
- * forego this double-multiplication or it could be performed
- * as fixed-point math.
- *
- * Note that caching should accommodates the case where the
- * condition applies to multiple channels (i.e. don't assume
- * that all channels matching my_chann* have the same size...)
- */
- threshold = (uint64_t) (use_condition->threshold_ratio.value *
- (double) buffer_capacity);
- }
-
- condition_type = lttng_condition_get_type(condition);
- if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) {
- DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64,
- threshold, sample->highest_usage);
-
- /*
- * The low condition should only be triggered once _all_ of the
- * streams in a channel have gone below the "low" threshold.
- */
- if (sample->highest_usage <= threshold) {
- result = true;
- }
- } else {
- DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64,
- threshold, sample->highest_usage);
-
- /*
- * For high buffer usage scenarios, we want to trigger whenever
- * _any_ of the streams has reached the "high" threshold.
- */
- if (sample->highest_usage >= threshold) {
- result = true;
- }
- }
-
- return result;
-}
-
-static
-bool evaluate_session_consumed_size_condition(
- const struct lttng_condition *condition,
- uint64_t session_consumed_size)
-{
- uint64_t threshold;
- const struct lttng_condition_session_consumed_size *size_condition =
- container_of(condition,
- struct lttng_condition_session_consumed_size,
- parent);
-
- threshold = size_condition->consumed_threshold_bytes.value;
- DBG("[notification-thread] Session consumed size condition being evaluated: threshold = %" PRIu64 ", current size = %" PRIu64,
- threshold, session_consumed_size);
- return session_consumed_size >= threshold;
-}
-
-static
-int evaluate_buffer_condition(const struct lttng_condition *condition,
- struct lttng_evaluation **evaluation,
- const struct notification_thread_state *state,
- const struct channel_state_sample *previous_sample,
- const struct channel_state_sample *latest_sample,
- uint64_t previous_session_consumed_total,
- uint64_t latest_session_consumed_total,
- struct channel_info *channel_info)
-{
- int ret = 0;
- enum lttng_condition_type condition_type;
- const bool previous_sample_available = !!previous_sample;
- bool previous_sample_result = false;
- bool latest_sample_result;
-
- condition_type = lttng_condition_get_type(condition);
-
- switch (condition_type) {
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
- if (caa_likely(previous_sample_available)) {
- previous_sample_result =
- evaluate_buffer_usage_condition(condition,
- previous_sample, channel_info->capacity);
- }
- latest_sample_result = evaluate_buffer_usage_condition(
- condition, latest_sample,
- channel_info->capacity);
- break;
- case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
- if (caa_likely(previous_sample_available)) {
- previous_sample_result =
- evaluate_session_consumed_size_condition(
- condition,
- previous_session_consumed_total);
- }
- latest_sample_result =
- evaluate_session_consumed_size_condition(
- condition,
- latest_session_consumed_total);
- break;
- default:
- /* Unknown condition type; internal error. */
- abort();
- }
-
- if (!latest_sample_result ||
- (previous_sample_result == latest_sample_result)) {
- /*
- * Only trigger on a condition evaluation transition.
- *
- * NOTE: This edge-triggered logic may not be appropriate for
- * future condition types.
- */
- goto end;
- }
-
- if (!evaluation || !latest_sample_result) {
- goto end;
- }
-
- switch (condition_type) {
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
- case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
- *evaluation = lttng_evaluation_buffer_usage_create(
- condition_type,
- latest_sample->highest_usage,
- channel_info->capacity);
- break;
- case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
- *evaluation = lttng_evaluation_session_consumed_size_create(
- latest_session_consumed_total);
- break;
- default:
- abort();
- }
-
- if (!*evaluation) {
- ret = -1;
- goto end;
- }
-end:
- return ret;
-}
-
-static
-int client_notification_overflow(struct notification_client *client)
-{
- int ret = 0;
- const struct lttng_notification_channel_message msg = {
- .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED,
- };
-
- 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.payload.buffer, &msg,
- sizeof(msg));
- if (ret) {
- PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue",
- client->socket);
- }
-end:
- return ret;
-}
-
-static int client_handle_transmission_status_wrapper(
- struct notification_client *client,
- enum client_transmission_status status,
- void *user_data)
-{
- return client_handle_transmission_status(client, status,
- (struct notification_thread_state *) user_data);
-}
-
-static
-int send_evaluation_to_clients(const struct lttng_trigger *trigger,
- const struct lttng_evaluation *evaluation,
- struct notification_client_list* client_list,
- struct notification_thread_state *state,
- uid_t object_uid, gid_t object_gid)
-{
- return notification_client_list_send_evaluation(client_list,
- lttng_trigger_get_const_condition(trigger), evaluation,
- lttng_trigger_get_credentials(trigger),
- &(struct lttng_credentials){
- .uid = object_uid, .gid = object_gid},
- client_handle_transmission_status_wrapper, state);
-}
-
-/*
- * Permission checks relative to notification channel clients are performed
- * here. Notice how object, client, and trigger credentials are involved in
- * this check.
- *
- * The `object` credentials are the credentials associated with the "subject"
- * of a condition. For instance, a `rotation completed` condition applies
- * to a session. When that condition is met, it will produce an evaluation
- * against a session. Hence, in this case, the `object` credentials are the
- * credentials of the "subject" session.
- *
- * The `trigger` credentials are the credentials of the user that registered the
- * trigger.
- *
- * The `client` credentials are the credentials of the user that created a given
- * notification channel.
- *
- * In terms of visibility, it is expected that non-privilieged users can only
- * register triggers against "their" objects (their own sessions and
- * applications they are allowed to interact with). They can then open a
- * notification channel and subscribe to notifications associated with those
- * triggers.
- *
- * As for privilieged users, they can register triggers against the objects of
- * other users. They can then subscribe to the notifications associated to their
- * triggers. Privilieged users _can't_ subscribe to the notifications of
- * triggers owned by other users; they must create their own triggers.
- *
- * This is more a concern of usability than security. It would be difficult for
- * a root user reliably subscribe to a specific set of conditions without
- * interference from external users (those could, for instance, unregister
- * their triggers).
- */
-LTTNG_HIDDEN
-int notification_client_list_send_evaluation(
- struct notification_client_list *client_list,
- const struct lttng_condition *condition,
- const struct lttng_evaluation *evaluation,
- const struct lttng_credentials *trigger_creds,
- const struct lttng_credentials *source_object_creds,
- report_client_transmission_result_cb client_report,
- void *user_data)
-{
- int ret = 0;
- struct lttng_payload msg_payload;
- struct notification_client_list_element *client_list_element, *tmp;
- const struct lttng_notification notification = {
- .condition = (struct lttng_condition *) condition,
- .evaluation = (struct lttng_evaluation *) evaluation,
- };
- struct lttng_notification_channel_message msg_header = {
- .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION,
- };
-
- lttng_payload_init(&msg_payload);
-
- ret = lttng_dynamic_buffer_append(&msg_payload.buffer, &msg_header,
- sizeof(msg_header));
- if (ret) {
- goto end;
- }
-
- ret = lttng_notification_serialize(¬ification, &msg_payload);
- if (ret) {
- ERR("[notification-thread] Failed to serialize notification");
- ret = -1;
- goto end;
- }
-
- /* Update payload size. */
- ((struct lttng_notification_channel_message *) msg_payload.buffer.data)
- ->size = (uint32_t)(
- msg_payload.buffer.size - sizeof(msg_header));
-
- /* Update the payload number of fds. */
- {
- const struct lttng_payload_view pv = lttng_payload_view_from_payload(
- &msg_payload, 0, -1);
-
- ((struct lttng_notification_channel_message *)
- msg_payload.buffer.data)->fds = (uint32_t)
- lttng_payload_view_get_fd_handle_count(&pv);
- }
-
- pthread_mutex_lock(&client_list->lock);
- cds_list_for_each_entry_safe(client_list_element, tmp,
- &client_list->list, node) {
- enum client_transmission_status transmission_status;
- struct notification_client *client =
- client_list_element->client;
-
- ret = 0;
- pthread_mutex_lock(&client->lock);
- if (!client->communication.active) {
- /*
- * Skip inactive client (protocol error or
- * disconnecting).
- */
- DBG("Skipping client at it is marked as inactive");
- goto skip_client;
- }
-
- if (source_object_creds) {
- if (client->uid != 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 skip_client;
- }
- }
-
- 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 skip_client;
- }
-
- DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)",
- client->socket, msg_payload.buffer.size);
-
- if (client_has_outbound_data_left(client)) {
- /*
- * Outgoing data is already buffered for this client;
- * drop the notification and enqueue a "dropped
- * notification" message if this is the first dropped
- * notification since the socket spilled-over to the
- * queue.
- */
- ret = client_notification_overflow(client);
- if (ret) {
- /* Fatal error. */
- goto skip_client;
- }
- }
-
- ret = lttng_payload_copy(&msg_payload, &client->communication.outbound.payload);
- if (ret) {
- /* Fatal error. */
- goto skip_client;
- }
-
- transmission_status = client_flush_outgoing_queue(client);
- pthread_mutex_unlock(&client->lock);
- ret = client_report(client, transmission_status, user_data);
- if (ret) {
- /* Fatal error. */
- goto end_unlock_list;
- }
-
- continue;
-
-skip_client:
- pthread_mutex_unlock(&client->lock);
- if (ret) {
- /* Fatal error. */
- goto end_unlock_list;
- }
- }
- ret = 0;
-
-end_unlock_list:
- pthread_mutex_unlock(&client_list->lock);
-end:
- lttng_payload_reset(&msg_payload);
- return ret;
-}
-
-int handle_notification_thread_channel_sample(
- struct notification_thread_state *state, int pipe,
- enum lttng_domain_type domain)
-{
- int ret = 0;
- struct lttcomm_consumer_channel_monitor_msg sample_msg;
- struct channel_info *channel_info;
- struct cds_lfht_node *node;
- struct cds_lfht_iter iter;
- struct lttng_channel_trigger_list *trigger_list;
- struct lttng_trigger_list_element *trigger_list_element;
- bool previous_sample_available = false;
- struct channel_state_sample previous_sample, latest_sample;
- uint64_t previous_session_consumed_total, latest_session_consumed_total;
- struct lttng_credentials channel_creds;
-
- /*
- * The monitoring pipe only holds messages smaller than PIPE_BUF,
- * ensuring that read/write of sampling messages are atomic.
- */
- ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg));
- if (ret != sizeof(sample_msg)) {
- ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)",
- pipe);
- ret = -1;
- goto end;
- }
-
- ret = 0;
- latest_sample.key.key = sample_msg.key;
- latest_sample.key.domain = domain;
- latest_sample.highest_usage = sample_msg.highest;
- latest_sample.lowest_usage = sample_msg.lowest;
- latest_sample.channel_total_consumed = sample_msg.total_consumed;
-
- rcu_read_lock();
-
- /* Retrieve the channel's informations */
- cds_lfht_lookup(state->channels_ht,
- hash_channel_key(&latest_sample.key),
- match_channel_info,
- &latest_sample.key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (caa_unlikely(!node)) {
- /*
- * Not an error since the consumer can push a sample to the pipe
- * and the rest of the session daemon could notify us of the
- * channel's destruction before we get a chance to process that
- * 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");
- goto end_unlock;
- }
- channel_info = caa_container_of(node, struct channel_info,
- channels_ht_node);
- DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64", total consumed = %" PRIu64")",
- channel_info->name,
- latest_sample.key.key,
- channel_info->session_info->name,
- latest_sample.highest_usage,
- latest_sample.lowest_usage,
- latest_sample.channel_total_consumed);
-
- previous_session_consumed_total =
- channel_info->session_info->consumed_data_size;
-
- /* Retrieve the channel's last sample, if it exists, and update it. */
- cds_lfht_lookup(state->channel_state_ht,
- hash_channel_key(&latest_sample.key),
- match_channel_state_sample,
- &latest_sample.key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (caa_likely(node)) {
- struct channel_state_sample *stored_sample;
-
- /* Update the sample stored. */
- stored_sample = caa_container_of(node,
- struct channel_state_sample,
- channel_state_ht_node);
-
- memcpy(&previous_sample, stored_sample,
- sizeof(previous_sample));
- stored_sample->highest_usage = latest_sample.highest_usage;
- stored_sample->lowest_usage = latest_sample.lowest_usage;
- stored_sample->channel_total_consumed = latest_sample.channel_total_consumed;
- previous_sample_available = true;
-
- latest_session_consumed_total =
- previous_session_consumed_total +
- (latest_sample.channel_total_consumed - previous_sample.channel_total_consumed);
- } else {
- /*
- * This is the channel's first sample, allocate space for and
- * store the new sample.
- */
- struct channel_state_sample *stored_sample;
-
- stored_sample = zmalloc(sizeof(*stored_sample));
- if (!stored_sample) {
- ret = -1;
- goto end_unlock;
- }
-
- memcpy(stored_sample, &latest_sample, sizeof(*stored_sample));
- cds_lfht_node_init(&stored_sample->channel_state_ht_node);
- cds_lfht_add(state->channel_state_ht,
- hash_channel_key(&stored_sample->key),
- &stored_sample->channel_state_ht_node);
-
- latest_session_consumed_total =
- previous_session_consumed_total +
- latest_sample.channel_total_consumed;
- }
-
- channel_info->session_info->consumed_data_size =
- latest_session_consumed_total;
-
- /* Find triggers associated with this channel. */
- cds_lfht_lookup(state->channel_triggers_ht,
- hash_channel_key(&latest_sample.key),
- match_channel_trigger_list,
- &latest_sample.key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (caa_likely(!node)) {
- goto end_unlock;
- }
-
- channel_creds = (typeof(channel_creds)) {
- .uid = channel_info->session_info->uid,
- .gid = channel_info->session_info->gid,
- };
-
- trigger_list = caa_container_of(node, struct lttng_channel_trigger_list,
- channel_triggers_ht_node);
- cds_list_for_each_entry(trigger_list_element, &trigger_list->list,
- node) {
- const struct lttng_condition *condition;
- struct lttng_trigger *trigger;
- struct notification_client_list *client_list = NULL;
- struct lttng_evaluation *evaluation = NULL;
- enum action_executor_status executor_status;
-
- ret = 0;
- trigger = trigger_list_element->trigger;
- condition = lttng_trigger_get_const_condition(trigger);
- assert(condition);
-
- /*
- * Check if any client is subscribed to the result of this
- * evaluation.
- */
- client_list = get_client_list_from_condition(state, condition);
-
- ret = evaluate_buffer_condition(condition, &evaluation, state,
- previous_sample_available ? &previous_sample : NULL,
- &latest_sample,
- previous_session_consumed_total,
- latest_session_consumed_total,
- channel_info);
- if (caa_unlikely(ret)) {
- goto put_list;
- }
-
- if (caa_likely(!evaluation)) {
- goto put_list;
- }
-
- /*
- * Ownership of `evaluation` transferred to the action executor
- * no matter the result.
- */
- executor_status = action_executor_enqueue(state->executor,
- trigger, evaluation, &channel_creds,
- client_list);
- evaluation = NULL;
- switch (executor_status) {
- case ACTION_EXECUTOR_STATUS_OK:
- break;
- case ACTION_EXECUTOR_STATUS_ERROR:
- case ACTION_EXECUTOR_STATUS_INVALID:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- */
- ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
- ret = -1;
- goto put_list;
- case ACTION_EXECUTOR_STATUS_OVERFLOW:
- /*
- * TODO Add trigger identification (name/id) when
- * it is added to the API.
- *
- * Not a fatal error.
- */
- WARN("No space left when enqueuing action associated with buffer-condition trigger");
- ret = 0;
- goto put_list;
- default:
- abort();
- }
-
-put_list:
- notification_client_list_put(client_list);
- if (caa_unlikely(ret)) {
- break;
- }
- }
-end_unlock:
- rcu_read_unlock();
-end:
- return ret;
-}
projects / lttng-tools.git / blobdiff