X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;h=833b550f87067672a682ccc99bcec710361c90be;hp=e20c476f830342612721dfb0f5d93c9474b80e08;hb=b42ada9013db5428c0fbca358e87c001f5b7e8c4;hpb=7c2551ef99cb5b7a927373a198013601ee43fd9a diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c index e20c476f8..833b550f8 100644 --- a/src/bin/lttng-sessiond/notification-thread-events.c +++ b/src/bin/lttng-sessiond/notification-thread-events.c @@ -1,27 +1,16 @@ /* - * Copyright (C) 2017 - Jérémie Galarneau + * Copyright (C) 2017 Jérémie Galarneau * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License, version 2 only, as - * published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ +#include "lttng/action/action.h" +#include "lttng/trigger/trigger-internal.h" #define _LGPL_SOURCE #include #include -#include "notification-thread.h" -#include "notification-thread-events.h" -#include "notification-thread-commands.h" #include #include #include @@ -31,33 +20,104 @@ #include #include #include -#include +#include #include #include #include +#include +#include +#include +#include #include +#include +#include + #include #include #include #include +#include + +#include "condition-internal.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; + struct cds_lfht_node node_by_name_uid; + /* call_rcu delayed reclaim. */ + struct rcu_head rcu_node; }; struct lttng_condition_list_element { @@ -65,75 +125,17 @@ struct lttng_condition_list_element { struct cds_list_head node; }; -struct notification_client_list_element { - struct notification_client *client; - struct cds_list_head node; -}; - -struct notification_client_list { - struct lttng_trigger *trigger; - struct cds_list_head list; - struct cds_lfht_node notification_trigger_ht_node; -}; - -struct notification_client { - int socket; - /* Client protocol version. */ - uint8_t major, minor; - uid_t uid; - gid_t gid; - /* - * Indicates if the credentials and versions of the client has been - * checked. - */ - bool validated; - /* - * Conditions to which the client's notification channel is subscribed. - * List of struct lttng_condition_list_node. The condition member is - * owned by the client. - */ - struct cds_list_head condition_list; - struct cds_lfht_node client_socket_ht_node; - struct { - struct { - struct lttng_dynamic_buffer buffer; - /* Bytes left to receive for the current message. */ - size_t bytes_to_receive; - /* Type of the message being received. */ - enum lttng_notification_channel_message_type msg_type; - /* - * Indicates whether or not credentials are expected - * from the client. - */ - bool receive_creds; - /* - * Indicates whether or not credentials were received - * from the client. - */ - bool creds_received; - lttng_sock_cred creds; - } inbound; - struct { - /* - * Indicates whether or not a notification addressed to - * this client was dropped because a command reply was - * already buffered. - * - * A notification is dropped whenever the buffer is not - * empty. - */ - bool dropped_notification; - /* - * Indicates whether or not a command reply is already - * buffered. In this case, it means that the client is - * not consuming command replies before emitting a new - * one. This could be caused by a protocol error or a - * misbehaving/malicious client. - */ - bool queued_command_reply; - struct lttng_dynamic_buffer buffer; - } outbound; - } communication; +/* + * Facilities to carry the different notifications type in the action processing + * code path. + */ +struct lttng_event_notifier_notification { + union { + struct lttng_ust_event_notifier_notification *ust; + struct lttng_kernel_event_notifier_notification *kernel; + } notification; + uint64_t token; + enum lttng_domain_type type; }; struct channel_state_sample { @@ -141,19 +143,92 @@ struct channel_state_sample { 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(struct cds_lfht_node *node, const void *key) +void free_lttng_trigger_ht_element_rcu(struct rcu_head *node); + +static +int match_client_socket(struct cds_lfht_node *node, const void *key) { /* This double-cast is intended to supress pointer-to-cast warning. */ - int socket = (int) (intptr_t) key; - struct notification_client *client; + const int socket = (int) (intptr_t) key; + const struct notification_client *client = caa_container_of(node, + struct notification_client, client_socket_ht_node); - client = caa_container_of(node, struct notification_client, - client_socket_ht_node); + return client->socket == socket; +} + +static +int match_client_id(struct cds_lfht_node *node, const void *key) +{ + /* This double-cast is intended to supress pointer-to-cast warning. */ + const notification_client_id id = *((notification_client_id *) key); + const struct notification_client *client = caa_container_of( + node, struct notification_client, client_id_ht_node); - return !!(client->socket == socket); + return client->id == id; } static @@ -169,6 +244,18 @@ int match_channel_trigger_list(struct cds_lfht_node *node, const void *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) { @@ -196,36 +283,26 @@ int match_channel_info(struct cds_lfht_node *node, const void *key) } static -int match_condition(struct cds_lfht_node *node, const void *key) +int match_trigger(struct cds_lfht_node *node, const void *key) { - struct lttng_condition *condition_key = (struct lttng_condition *) key; - struct lttng_trigger_ht_element *trigger; - struct lttng_condition *condition; + struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; + struct lttng_trigger_ht_element *trigger_ht_element; - trigger = caa_container_of(node, struct lttng_trigger_ht_element, + trigger_ht_element = caa_container_of(node, struct lttng_trigger_ht_element, node); - condition = lttng_trigger_get_condition(trigger->trigger); - assert(condition); - return !!lttng_condition_is_equal(condition_key, condition); + return !!lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger); } static -int match_client_list(struct cds_lfht_node *node, const void *key) +int match_trigger_token(struct cds_lfht_node *node, const void *key) { - struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; - struct notification_client_list *client_list; - struct lttng_condition *condition; - struct lttng_condition *condition_key = lttng_trigger_get_condition( - trigger_key); - - assert(condition_key); - - client_list = caa_container_of(node, struct notification_client_list, - notification_trigger_ht_node); - condition = lttng_trigger_get_condition(client_list->trigger); + const uint64_t *_key = key; + struct notification_trigger_tokens_ht_element *element; - return !!lttng_condition_is_equal(condition_key, condition); + element = caa_container_of(node, + struct notification_trigger_tokens_ht_element, node); + return *_key == element->token; } static @@ -233,70 +310,179 @@ 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; - struct lttng_condition *condition; + const struct lttng_condition *condition; assert(condition_key); client_list = caa_container_of(node, struct notification_client_list, - notification_trigger_ht_node); - condition = lttng_trigger_get_condition(client_list->trigger); + notification_trigger_clients_ht_node); + condition = lttng_trigger_get_const_condition(client_list->trigger); return !!lttng_condition_is_equal(condition_key, condition); } static -unsigned long lttng_condition_buffer_usage_hash( - struct lttng_condition *_condition) +int match_session(struct cds_lfht_node *node, const void *key) { - unsigned long hash = 0; - struct lttng_condition_buffer_usage *condition; + const char *name = key; + struct session_info *session_info = caa_container_of( + node, struct session_info, sessions_ht_node); - condition = container_of(_condition, - struct lttng_condition_buffer_usage, parent); + return !strcmp(session_info->name, name); +} - 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); +static +const char *notification_command_type_str( + enum notification_thread_command_type type) +{ + switch (type) { + case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: + return "REGISTER_TRIGGER"; + case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: + return "UNREGISTER_TRIGGER"; + case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: + return "ADD_CHANNEL"; + case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: + return "REMOVE_CHANNEL"; + case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING: + return "SESSION_ROTATION_ONGOING"; + case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED: + return "SESSION_ROTATION_COMPLETED"; + case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE: + return "ADD_TRACER_EVENT_SOURCE"; + case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE: + return "REMOVE_TRACER_EVENT_SOURCE"; + case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS: + return "LIST_TRIGGERS"; + case NOTIFICATION_COMMAND_TYPE_QUIT: + return "QUIT"; + case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE: + return "CLIENT_COMMUNICATION_UPDATE"; + default: + abort(); } - if (condition->domain.set) { - hash ^= hash_key_ulong( - (void *) condition->domain.type, - lttng_ht_seed); +} + +/* + * Match trigger based on name and credentials only. + * Name duplication is NOT allowed for the same uid. + */ +static +int match_trigger_by_name_uid(struct cds_lfht_node *node, + const void *key) +{ + bool match = false; + const char *name; + const char *key_name; + enum lttng_trigger_status status; + const struct lttng_credentials *key_creds; + const struct lttng_credentials *node_creds; + const struct lttng_trigger *trigger_key = + (const struct lttng_trigger *) key; + const struct lttng_trigger_ht_element *trigger_ht_element = + caa_container_of(node, + struct lttng_trigger_ht_element, + node_by_name_uid); + + status = lttng_trigger_get_name(trigger_ht_element->trigger, &name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + status = lttng_trigger_get_name(trigger_key, &key_name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + /* Compare the names. */ + if (strcmp(name, key_name) != 0) { + goto end; } - 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_ratio.set) { - uint64_t val; + /* Compare the owners' UIDs. */ + key_creds = lttng_trigger_get_credentials(trigger_key); + node_creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); + + match = lttng_credentials_is_equal_uid(key_creds, node_creds); + +end: + return match; +} + +/* + * Hash trigger based on name and credentials only. + */ +static +unsigned long hash_trigger_by_name_uid(const struct lttng_trigger *trigger) +{ + unsigned long hash = 0; + const struct lttng_credentials *trigger_creds; + const char *trigger_name; + enum lttng_trigger_status status; - val = condition->threshold_bytes.value; - hash ^= hash_key_u64(&val, lttng_ht_seed); + status = lttng_trigger_get_name(trigger, &trigger_name); + if (status == LTTNG_TRIGGER_STATUS_OK) { + hash = hash_key_str(trigger_name, lttng_ht_seed); } + + trigger_creds = lttng_trigger_get_credentials(trigger); + hash ^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds->uid), + lttng_ht_seed); + return hash; } +static +unsigned long 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); +} + /* - * 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. + * 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 -unsigned long lttng_condition_hash(struct lttng_condition *condition) +enum lttng_object_type get_condition_binding_object( + const struct lttng_condition *condition) { - switch (condition->type) { + switch (lttng_condition_get_type(condition)) { 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_OBJECT_TYPE_CHANNEL; + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: + return LTTNG_OBJECT_TYPE_SESSION; + case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT: + return LTTNG_OBJECT_TYPE_NONE; default: - ERR("[notification-thread] Unexpected condition type caught"); - abort(); + 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) { @@ -304,179 +490,253 @@ void channel_info_destroy(struct channel_info *channel_info) return; } - if (channel_info->session_name) { - free(channel_info->session_name); + 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->channel_name) { - free(channel_info->channel_name); + if (channel_info->name) { + free(channel_info->name); } - free(channel_info); + call_rcu(&channel_info->rcu_node, free_channel_info_rcu); +} + +static +void free_session_info_rcu(struct rcu_head *node) +{ + free(caa_container_of(node, struct session_info, rcu_node)); } +/* Don't call directly, use the ref-counting mechanism. */ static -struct channel_info *channel_info_copy(struct channel_info *channel_info) +void session_info_destroy(void *_data) { - struct channel_info *copy = zmalloc(sizeof(*channel_info)); + struct session_info *session_info = _data; + int ret; - assert(channel_info); - assert(channel_info->session_name); - assert(channel_info->channel_name); + 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); - if (!copy) { - goto end; + 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; - memcpy(copy, channel_info, sizeof(*channel_info)); - copy->session_name = NULL; - copy->channel_name = NULL; + assert(name); - copy->session_name = strdup(channel_info->session_name); - if (!copy->session_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; } - copy->channel_name = strdup(channel_info->channel_name); - if (!copy->channel_name) { + + cds_lfht_node_init(&session_info->sessions_ht_node); + session_info->name = strdup(name); + if (!session_info->name) { goto error; } - cds_lfht_node_init(&channel_info->channels_ht_node); + session_info->uid = uid; + session_info->gid = gid; + session_info->trigger_list = trigger_list; + session_info->sessions_ht = sessions_ht; end: - return copy; + return session_info; error: - channel_info_destroy(copy); + session_info_put(session_info); return NULL; } 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) +void session_info_add_channel(struct session_info *session_info, + struct channel_info *channel_info) { - int ret = 0; - struct cds_lfht_iter iter; - struct cds_lfht_node *node; - struct notification_client_list *client_list; - 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; + 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(); +} - /* - * 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; - } - } +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(); +} - condition_list_element = zmalloc(sizeof(*condition_list_element)); - if (!condition_list_element) { - ret = -1; - goto error; +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; } - client_list_element = zmalloc(sizeof(*client_list_element)); - if (!client_list_element) { - ret = -1; + + 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; } - rcu_read_lock(); - /* - * Add the newly-subscribed condition to the client's subscription list. + * 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 */ - CDS_INIT_LIST_HEAD(&condition_list_element->node); - condition_list_element->condition = condition; - cds_list_add(&condition_list_element->node, &client->condition_list); + 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; +} - /* - * Add the client to the list of clients interested in a given trigger - * if a "notification" trigger with a corresponding condition was - * added prior. - */ - 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) { - free(client_list_element); - goto end_unlock; - } +LTTNG_HIDDEN +bool notification_client_list_get(struct notification_client_list *list) +{ + return urcu_ref_get_unless_zero(&list->ref); +} - client_list = caa_container_of(node, struct notification_client_list, - notification_trigger_ht_node); - client_list_element->client = client; - CDS_INIT_LIST_HEAD(&client_list_element->node); - cds_list_add(&client_list_element->node, &client_list->list); -end_unlock: - rcu_read_unlock(); -end: - if (_status) { - *_status = status; +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; } - return ret; + 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: - free(condition_list_element); - free(client_list_element); - return ret; + return client_list; } static -int notification_thread_client_unsubscribe( - struct notification_client *client, - struct lttng_condition *condition, +void publish_notification_client_list( struct notification_thread_state *state, - enum lttng_notification_channel_status *_status) + struct notification_client_list *list) { - struct cds_lfht_iter iter; - struct cds_lfht_node *node; - 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; + const struct lttng_condition *condition = + lttng_trigger_get_const_condition(list->trigger); - /* 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; - } + assert(!list->notification_trigger_clients_ht); + notification_client_list_get(list); - 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; - } + list->notification_trigger_clients_ht = + state->notification_trigger_clients_ht; - if (!condition_found) { - status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; - goto end; + 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; - /* - * Remove the client from the list of clients interested the trigger - * matching the condition. - */ rcu_read_lock(); cds_lfht_lookup(state->notification_trigger_clients_ht, lttng_condition_hash(condition), @@ -484,351 +744,1695 @@ int notification_thread_client_unsubscribe( condition, &iter); node = cds_lfht_iter_get_node(&iter); - if (!node) { - goto end_unlock; + if (node) { + list = container_of(node, struct notification_client_list, + notification_trigger_clients_ht_node); + list = notification_client_list_get(list) ? list : NULL; } - client_list = caa_container_of(node, struct notification_client_list, - notification_trigger_ht_node); - cds_list_for_each_entry_safe(client_list_element, client_tmp, - &client_list->list, node) { - if (client_list_element->client->socket != client->socket) { - continue; - } - cds_list_del(&client_list_element->node); - free(client_list_element); - break; - } -end_unlock: rcu_read_unlock(); -end: - lttng_condition_destroy(condition); - if (_status) { - *_status = status; - } - return 0; + return list; } static -void notification_client_destroy(struct notification_client *client, - struct notification_thread_state *state) +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) { - struct lttng_condition_list_element *condition_list_element, *tmp; + 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; - if (!client) { - return; - } + rcu_read_lock(); - /* 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); + /* 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 (client->socket >= 0) { - (void) lttcomm_close_unix_sock(client->socket); + if (!channel_key){ + /* No channel found; normal exit. */ + DBG("[notification-thread] No known channel associated with newly subscribed-to condition"); + ret = 0; + goto end; } - lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); - lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); - free(client); -} -/* - * 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; + /* 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); - cds_lfht_lookup(state->client_socket_ht, - hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), - match_client, - (void *) (unsigned long) socket, + /* 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) { + 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; } - client = caa_container_of(node, struct notification_client, - client_socket_ht_node); + 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: - return client; + rcu_read_unlock(); + return ret; } static -bool trigger_applies_to_channel(struct lttng_trigger *trigger, - struct channel_info *info) +const char *get_condition_session_name(const struct lttng_condition *condition) { + const char *session_name = NULL; enum lttng_condition_status status; - struct lttng_condition *condition; - const char *trigger_session_name = NULL; - const char *trigger_channel_name = NULL; - enum lttng_domain_type trigger_domain; - - condition = lttng_trigger_get_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: + 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: - goto fail; + abort(); } - - status = lttng_condition_buffer_usage_get_domain_type(condition, - &trigger_domain); - assert(status == LTTNG_CONDITION_STATUS_OK); - if (info->key.domain != trigger_domain) { - goto fail; + if (status != LTTNG_CONDITION_STATUS_OK) { + ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); + goto end; } +end: + return session_name; +} - status = lttng_condition_buffer_usage_get_session_name( - condition, &trigger_session_name); - assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_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; - status = lttng_condition_buffer_usage_get_channel_name( - condition, &trigger_channel_name); - assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); + rcu_read_lock(); + session_name = get_condition_session_name(condition); - if (strcmp(info->session_name, trigger_session_name)) { - goto fail; - } - if (strcmp(info->channel_name, trigger_channel_name)) { - goto fail; + /* 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; } - return true; -fail: - return false; -} + session_info = caa_container_of(node, struct session_info, + sessions_ht_node); + session_info_get(session_info); -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; + /* + * 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; + } - 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; + *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; } - return applies; -} -static -unsigned long hash_channel_key(struct channel_key *key) -{ - return hash_key_u64(&key->key, lttng_ht_seed) ^ hash_key_ulong( - (void *) (unsigned long) key->domain, lttng_ht_seed); + *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 handle_notification_thread_command_add_channel( - struct notification_thread_state *state, - struct channel_info *channel_info, - enum lttng_error_code *cmd_result) +int evaluate_condition_for_client(const struct lttng_trigger *trigger, + const struct lttng_condition *condition, + struct notification_client *client, + struct notification_thread_state *state) { - struct cds_list_head trigger_list; - struct channel_info *new_channel_info; - struct channel_key *channel_key; - 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; - - DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", - channel_info->channel_name, channel_info->session_name, - channel_info->key.key, channel_info->key.domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); + 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; - CDS_INIT_LIST_HEAD(&trigger_list); + assert(trigger); + assert(condition); + assert(client); + assert(state); - new_channel_info = channel_info_copy(channel_info); - if (!new_channel_info) { - goto error; + 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: + DBG("[notification-thread] Newly subscribed-to condition not bound to object, nothing to evaluate"); + 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; - channel_key = &new_channel_info->key; + CDS_INIT_LIST_HEAD(&client_list_element.node); + client_list_element.client = client; + cds_list_add(&client_list_element.node, &client_list.list); - /* 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; + /* 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); - if (!trigger_applies_to_channel(trigger_ht_element->trigger, - channel_info)) { - continue; - } +end: + return ret; +} - new_element = zmalloc(sizeof(*new_element)); - if (!new_element) { - goto error; +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; } - CDS_INIT_LIST_HEAD(&new_element->node); - new_element->trigger = trigger_ht_element->trigger; - cds_list_add(&new_element->node, &trigger_list); - trigger_count++; } - 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) { + 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; } - channel_trigger_list->channel_key = *channel_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(channel_key), - &new_channel_info->channels_ht_node); /* - * Add the list of triggers associated with this channel to the - * channel_triggers_ht. + * Add the newly-subscribed condition to the client's subscription list. */ - cds_lfht_add(state->channel_triggers_ht, - hash_channel_key(channel_key), - &channel_trigger_list->channel_triggers_ht_node); - rcu_read_unlock(); - *cmd_result = LTTNG_OK; - return 0; + 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: - /* Empty trigger list */ - channel_info_destroy(new_channel_info); - return 1; + free(condition_list_element); + free(client_list_element); + return ret; } 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) +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 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; + 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; - DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", - channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); + /* 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; + } - rcu_read_lock(); + 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; + } - 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. + * Remove the client from the list of clients interested the trigger + * matching the condition. */ - if (!node) { - ERR("[notification-thread] Channel being removed is unknown to the notification thread"); + client_list = get_client_list_from_condition(state, condition); + if (!client_list) { 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); + 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; } - cds_lfht_del(state->channel_triggers_ht, node); - free(trigger_list); + 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; +} - /* 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); +static +void free_notification_client_rcu(struct rcu_head *node) +{ + free(caa_container_of(node, struct notification_client, rcu_node)); +} - cds_lfht_del(state->channel_state_ht, node); - free(sample); +static +void notification_client_destroy(struct notification_client *client, + struct notification_thread_state *state) +{ + if (!client) { + return; } - /* Remove the channel from the channels_ht and free it. */ - cds_lfht_lookup(state->channels_ht, - hash_channel_key(&key), - match_channel_info, - &key, + /* + * 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); - 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); + 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(); - *cmd_result = LTTNG_OK; - return 0; + 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 = LTTNG_OPTIONAL_INIT_VALUE(session_uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(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 handle_notification_thread_command_add_tracer_event_source( + struct notification_thread_state *state, + int tracer_event_source_fd, + enum lttng_domain_type domain_type, + enum lttng_error_code *_cmd_result) +{ + int ret = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_tracer_event_source_element *element = NULL; + + element = zmalloc(sizeof(*element)); + if (!element) { + cmd_result = LTTNG_ERR_NOMEM; + ret = -1; + goto end; + } + + element->fd = tracer_event_source_fd; + element->domain = domain_type; + + cds_list_add(&element->node, &state->tracer_event_sources_list); + + DBG3("[notification-thread] Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(domain_type)); + + /* Adding the read side pipe to the event poll. */ + ret = lttng_poll_add(&state->events, tracer_event_source_fd, LPOLLIN | LPOLLERR); + if (ret < 0) { + ERR("[notification-thread] Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(element->domain)); + cds_list_del(&element->node); + free(element); + goto end; + } + + element->is_fd_in_poll_set = true; + +end: + *_cmd_result = cmd_result; + return ret; +} + +static +int handle_notification_thread_command_remove_tracer_event_source( + struct notification_thread_state *state, + int tracer_event_source_fd, + enum lttng_error_code *_cmd_result) +{ + int ret = 0; + bool found = false; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_tracer_event_source_element *source_element = NULL, *tmp; + + cds_list_for_each_entry_safe(source_element, tmp, + &state->tracer_event_sources_list, node) { + if (source_element->fd != tracer_event_source_fd) { + continue; + } + + DBG("[notification-thread] Removed tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + cds_list_del(&source_element->node); + found = true; + break; + } + + if (!found) { + /* + * This is temporarily allowed since the poll activity set is + * not properly cleaned-up for the moment. This is adressed in + * an upcoming fix. + */ + source_element = NULL; + goto end; + } + + if (!source_element->is_fd_in_poll_set) { + /* Skip the poll set removal. */ + goto end; + } + + DBG3("[notification-thread] Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + + /* Removing the fd from the event poll set. */ + ret = lttng_poll_del(&state->events, tracer_event_source_fd); + if (ret < 0) { + ERR("[notification-thread] Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + tracer_event_source_fd, + lttng_domain_type_str(source_element->domain)); + cmd_result = LTTNG_ERR_FATAL; + goto end; + } + + source_element->is_fd_in_poll_set = false; + +end: + free(source_element); + *_cmd_result = cmd_result; + return ret; +} + +int handle_notification_thread_remove_tracer_event_source_no_result( + struct notification_thread_state *state, + int tracer_event_source_fd) +{ + int ret; + enum lttng_error_code cmd_result; + + ret = handle_notification_thread_command_remove_tracer_event_source( + state, tracer_event_source_fd, &cmd_result); + (void) cmd_result; + return ret; +} + +static int handle_notification_thread_command_list_triggers( + struct notification_thread_handle *handle, + struct notification_thread_state *state, + uid_t client_uid, + struct lttng_triggers **triggers, + enum lttng_error_code *_cmd_result) +{ + int ret = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct cds_lfht_iter iter; + struct lttng_trigger_ht_element *trigger_ht_element; + struct lttng_triggers *local_triggers = NULL; + const struct lttng_credentials *creds; + + rcu_read_lock(); + + local_triggers = lttng_triggers_create(); + if (!local_triggers) { + /* Not a fatal error. */ + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + + cds_lfht_for_each_entry(state->triggers_ht, &iter, + trigger_ht_element, node) { + /* + * Only return the triggers to which the client has access. + * The root user has visibility over all triggers. + */ + creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); + if (client_uid != lttng_credentials_get_uid(creds) && client_uid != 0) { + continue; + } + + ret = lttng_triggers_add(local_triggers, + trigger_ht_element->trigger); + if (ret < 0) { + /* Not a fatal error. */ + ret = 0; + cmd_result = LTTNG_ERR_NOMEM; + goto end; + } + } + + /* Transferring ownership to the caller. */ + *triggers = local_triggers; + local_triggers = NULL; + +end: + rcu_read_unlock(); + lttng_triggers_destroy(local_triggers); + *_cmd_result = cmd_result; + return ret; +} + +static +bool condition_is_supported(struct lttng_condition *condition) +{ + bool is_supported; + + switch (lttng_condition_get_type(condition)) { + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: + case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: + { + int ret; + enum lttng_domain_type domain; + + ret = lttng_condition_buffer_usage_get_domain_type(condition, + &domain); + assert(ret == 0); + + if (domain != LTTNG_DOMAIN_KERNEL) { + is_supported = true; + goto end; + } + + /* + * Older kernel tracers don't expose the API to monitor their + * buffers. Therefore, we reject triggers that require that + * mechanism to be available to be evaluated. + * + * Assume unsupported on error. + */ + is_supported = kernel_supports_ring_buffer_snapshot_sample_positions() == 1; + break; + } + case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT: + { + const struct lttng_event_rule *event_rule; + enum lttng_domain_type domain; + const enum lttng_condition_status status = + lttng_condition_event_rule_get_rule( + condition, &event_rule); + + assert(status == LTTNG_CONDITION_STATUS_OK); + + domain = lttng_event_rule_get_domain_type(event_rule); + if (domain != LTTNG_DOMAIN_KERNEL) { + is_supported = true; + goto end; + } + + /* + * Older kernel tracers can't emit notification. Therefore, we + * reject triggers that require that mechanism to be available + * to be evaluated. + * + * Assume unsupported on error. + */ + is_supported = kernel_supports_event_notifiers() == 1; + break; + } + default: + is_supported = true; + } +end: + return is_supported; +} + +/* Must be called with RCU read lock held. */ +static +int bind_trigger_to_matching_session(struct lttng_trigger *trigger, + struct notification_thread_state *state) +{ + int ret = 0; + const struct lttng_condition *condition; + const char *session_name; + struct lttng_session_trigger_list *trigger_list; + + condition = lttng_trigger_get_const_condition(trigger); + switch (lttng_condition_get_type(condition)) { + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: + case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: + { + enum lttng_condition_status status; + + status = lttng_condition_session_rotation_get_session_name( + condition, &session_name); + if (status != LTTNG_CONDITION_STATUS_OK) { + ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); + ret = -1; + goto end; + } + break; + } + default: + ret = -1; + goto end; + } + + trigger_list = get_session_trigger_list(state, session_name); + if (!trigger_list) { + DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", + session_name); + goto end; + + } + + DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", + session_name); + ret = lttng_session_trigger_list_add(trigger_list, trigger); +end: + return ret; +} + +/* Must be called with RCU read lock held. */ +static +int bind_trigger_to_matching_channels(struct lttng_trigger *trigger, + struct notification_thread_state *state) +{ + int ret = 0; + struct cds_lfht_node *node; + struct cds_lfht_iter iter; + struct channel_info *channel; + + cds_lfht_for_each_entry(state->channels_ht, &iter, channel, + channels_ht_node) { + struct lttng_trigger_list_element *trigger_list_element; + struct lttng_channel_trigger_list *trigger_list; + struct cds_lfht_iter lookup_iter; + + if (!trigger_applies_to_channel(trigger, channel)) { + continue; + } + + cds_lfht_lookup(state->channel_triggers_ht, + hash_channel_key(&channel->key), + match_channel_trigger_list, + &channel->key, + &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(action); + if (action_type == LTTNG_ACTION_TYPE_NOTIFY) { + is_notify = true; + goto end; + } else if (action_type != LTTNG_ACTION_TYPE_GROUP) { + goto end; + } + + action_status = lttng_action_group_get_count(action, &count); + assert(action_status == LTTNG_ACTION_STATUS_OK); + + for (i = 0; i < count; i++) { + const struct lttng_action *inner_action = + lttng_action_group_get_at_index( + action, i); + + action_type = lttng_action_get_type(inner_action); + if (action_type == LTTNG_ACTION_TYPE_NOTIFY) { + is_notify = true; + goto end; + } + } + +end: + return is_notify; +} + +static bool trigger_name_taken(struct notification_thread_state *state, + const struct lttng_trigger *trigger) +{ + struct cds_lfht_iter iter; + + /* + * No duplicata is allowed in the triggers_by_name_uid_ht. + * The match is done against the trigger name and uid. + */ + cds_lfht_lookup(state->triggers_by_name_uid_ht, + hash_trigger_by_name_uid(trigger), + match_trigger_by_name_uid, + trigger, + &iter); + return !!cds_lfht_iter_get_node(&iter); +} + +static +enum lttng_error_code generate_trigger_name( + struct notification_thread_state *state, + struct lttng_trigger *trigger, const char **name) +{ + enum lttng_error_code ret_code = LTTNG_OK; + bool taken = false; + enum lttng_trigger_status status; + + do { + const int ret = lttng_trigger_generate_name(trigger, + state->trigger_id.name_offset++); + if (ret) { + /* The only reason this can fail right now. */ + ret_code = LTTNG_ERR_NOMEM; + break; + } + + status = lttng_trigger_get_name(trigger, name); + assert(status == LTTNG_TRIGGER_STATUS_OK); + + taken = trigger_name_taken(state, trigger); + } while (taken || state->trigger_id.name_offset == UINT64_MAX); + + return ret_code; } /* - * FIXME A client's credentials are not checked when registering a trigger, nor - * are they stored alongside with the trigger. + * FIXME A client's credentials are not checked when registering a trigger. * - * The effects of this are benign: + * 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, + * - 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) + 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, *tmp; + struct notification_client_list_element *client_list_element; + struct notification_trigger_tokens_ht_element *trigger_tokens_ht_element = NULL; struct cds_lfht_node *node; struct cds_lfht_iter iter; - struct channel_info *channel; + const char* trigger_name; bool free_trigger = true; + struct lttng_evaluation *evaluation = NULL; + struct lttng_credentials object_creds; + uid_t object_uid; + gid_t object_gid; + enum action_executor_status executor_status; + const uint64_t trigger_tracer_token = + state->trigger_id.next_tracer_token++; rcu_read_lock(); + /* Set the trigger's tracer token. */ + lttng_trigger_set_tracer_token(trigger, trigger_tracer_token); + + if (lttng_trigger_get_name(trigger, &trigger_name) == + LTTNG_TRIGGER_STATUS_UNSET) { + const enum lttng_error_code ret_code = generate_trigger_name( + state, trigger, &trigger_name); + + if (ret_code != LTTNG_OK) { + /* Fatal error. */ + ret = -1; + *cmd_result = ret_code; + goto error; + } + } else if (trigger_name_taken(state, trigger)) { + /* Not a fatal error. */ + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + ret = 0; + goto error; + } + condition = lttng_trigger_get_condition(trigger); + assert(condition); + + /* Some conditions require tracers to implement a minimal ABI version. */ + if (!condition_is_supported(condition)) { + *cmd_result = LTTNG_ERR_NOT_SUPPORTED; + goto error; + } + trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); if (!trigger_ht_element) { ret = -1; @@ -837,12 +2441,13 @@ int handle_notification_thread_command_register_trigger( /* Add trigger to the trigger_ht. */ cds_lfht_node_init(&trigger_ht_element->node); + cds_lfht_node_init(&trigger_ht_element->node_by_name_uid); trigger_ht_element->trigger = trigger; node = cds_lfht_add_unique(state->triggers_ht, lttng_condition_hash(condition), - match_condition, - condition, + match_trigger, + trigger, &trigger_ht_element->node); if (node != &trigger_ht_element->node) { /* Not a fatal error, simply report it to the client. */ @@ -850,10 +2455,59 @@ int handle_notification_thread_command_register_trigger( goto error_free_ht_element; } + node = cds_lfht_add_unique(state->triggers_by_name_uid_ht, + hash_trigger_by_name_uid(trigger), + match_trigger_by_name_uid, + trigger, + &trigger_ht_element->node_by_name_uid); + if (node != &trigger_ht_element->node_by_name_uid) { + /* Not a fatal error, simply report it to the client. */ + cds_lfht_del(state->triggers_ht, &trigger_ht_element->node); + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + goto error_free_ht_element; + } + + if (lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT) { + trigger_tokens_ht_element = zmalloc(sizeof(*trigger_tokens_ht_element)); + if (!trigger_tokens_ht_element) { + /* Fatal error. */ + ret = -1; + cds_lfht_del(state->triggers_ht, + &trigger_ht_element->node); + cds_lfht_del(state->triggers_by_name_uid_ht, + &trigger_ht_element->node_by_name_uid); + goto error_free_ht_element; + } + + /* Add trigger token to the trigger_tokens_ht. */ + cds_lfht_node_init(&trigger_tokens_ht_element->node); + trigger_tokens_ht_element->token = + LTTNG_OPTIONAL_GET(trigger->tracer_token); + trigger_tokens_ht_element->trigger = trigger; + + node = cds_lfht_add_unique(state->trigger_tokens_ht, + hash_key_u64(&trigger_tokens_ht_element->token, + lttng_ht_seed), + match_trigger_token, + &trigger_tokens_ht_element->token, + &trigger_tokens_ht_element->node); + if (node != &trigger_tokens_ht_element->node) { + /* Internal corruption, fatal error. */ + ret = -1; + *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; + cds_lfht_del(state->triggers_ht, + &trigger_ht_element->node); + cds_lfht_del(state->triggers_by_name_uid_ht, + &trigger_ht_element->node_by_name_uid); + goto error_free_ht_element; + } + } + /* * Ownership of the trigger and of its wrapper was transfered to - * the triggers_ht. + * the triggers_ht. Same for token ht element if necessary. */ + trigger_tokens_ht_element = NULL; trigger_ht_element = NULL; free_trigger = false; @@ -862,123 +2516,224 @@ int handle_notification_thread_command_register_trigger( * It is not skipped as this is the only action type currently * supported. */ - client_list = zmalloc(sizeof(*client_list)); - if (!client_list) { - ret = -1; - goto error_free_ht_element; - } - cds_lfht_node_init(&client_list->notification_trigger_ht_node); - CDS_INIT_LIST_HEAD(&client_list->list); - client_list->trigger = trigger; - - /* Build a list of clients to which this new trigger applies. */ - cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, - client_socket_ht_node) { - if (!trigger_applies_to_client(trigger, client)) { - continue; + if (is_trigger_action_notify(trigger)) { + client_list = notification_client_list_create(trigger); + if (!client_list) { + ret = -1; + goto error_free_ht_element; } - client_list_element = zmalloc(sizeof(*client_list_element)); - if (!client_list_element) { - ret = -1; - goto error_free_client_list; + /* Build a list of clients to which this new trigger applies. */ + cds_lfht_for_each_entry (state->client_socket_ht, &iter, client, + client_socket_ht_node) { + if (!trigger_applies_to_client(trigger, client)) { + continue; + } + + client_list_element = + zmalloc(sizeof(*client_list_element)); + if (!client_list_element) { + ret = -1; + goto error_put_client_list; + } + + CDS_INIT_LIST_HEAD(&client_list_element->node); + client_list_element->client = client; + cds_list_add(&client_list_element->node, + &client_list->list); } - CDS_INIT_LIST_HEAD(&client_list_element->node); - client_list_element->client = client; - cds_list_add(&client_list_element->node, &client_list->list); + + /* + * Client list ownership transferred to the + * notification_trigger_clients_ht. + */ + publish_notification_client_list(state, client_list); } - cds_lfht_add(state->notification_trigger_clients_ht, - lttng_condition_hash(condition), - &client_list->notification_trigger_ht_node); - /* - * Client list ownership transferred to the - * notification_trigger_clients_ht. - */ - client_list = NULL; + 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; + } /* - * Add the trigger to list of triggers bound to the channels currently - * known. + * 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. */ - 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; + switch (get_condition_binding_object(condition)) { + case LTTNG_OBJECT_TYPE_SESSION: + ret = evaluate_session_condition_for_client(condition, state, + &evaluation, &object_uid, + &object_gid); + LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); + LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); + break; + case LTTNG_OBJECT_TYPE_CHANNEL: + ret = evaluate_channel_condition_for_client(condition, state, + &evaluation, &object_uid, + &object_gid); + LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); + LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); + break; + case LTTNG_OBJECT_TYPE_NONE: + ret = 0; + break; + case LTTNG_OBJECT_TYPE_UNKNOWN: + default: + ret = -1; + break; + } - if (!trigger_applies_to_channel(trigger, channel)) { - continue; - } + if (ret) { + /* Fatal error. */ + goto error_put_client_list; + } - cds_lfht_lookup(state->channel_triggers_ht, - hash_channel_key(&channel->key), - match_channel_trigger_list, - &channel->key, - &iter); - node = cds_lfht_iter_get_node(&iter); - assert(node); - /* Free the list of triggers associated with this channel. */ - trigger_list = caa_container_of(node, - struct lttng_channel_trigger_list, - channel_triggers_ht_node); + DBG("Newly registered trigger's condition evaluated to %s", + evaluation ? "true" : "false"); + if (!evaluation) { + /* Evaluation yielded nothing. Normal exit. */ + ret = 0; + goto end; + } - trigger_list_element = zmalloc(sizeof(*trigger_list_element)); - if (!trigger_list_element) { - ret = -1; - goto error_free_client_list; - } - CDS_INIT_LIST_HEAD(&trigger_list_element->node); - trigger_list_element->trigger = trigger; - cds_list_add(&trigger_list_element->node, &trigger_list->list); - /* A trigger can only apply to one channel. */ + /* + * 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 end; + default: + abort(); } +end: *cmd_result = LTTNG_OK; -error_free_client_list: - if (client_list) { - cds_list_for_each_entry_safe(client_list_element, tmp, - &client_list->list, node) { - free(client_list_element); - } - free(client_list); - } + DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64, + trigger_name, trigger_tracer_token); + +error_put_client_list: + notification_client_list_put(client_list); + error_free_ht_element: - free(trigger_ht_element); + if (trigger_ht_element) { + /* Delayed removal due to RCU constraint on delete. */ + call_rcu(&trigger_ht_element->rcu_node, + free_lttng_trigger_ht_element_rcu); + } + + free(trigger_tokens_ht_element); error: if (free_trigger) { - struct lttng_action *action = lttng_trigger_get_action(trigger); - - lttng_condition_destroy(condition); - lttng_action_destroy(action); lttng_trigger_destroy(trigger); } rcu_read_unlock(); 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 +void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head *node) +{ + free(caa_container_of(node, struct notification_trigger_tokens_ht_element, + rcu_node)); +} + +static int handle_notification_thread_command_unregister_trigger( struct notification_thread_state *state, - struct lttng_trigger *trigger, + const struct lttng_trigger *trigger, enum lttng_error_code *_cmd_reply) { struct cds_lfht_iter iter; - struct cds_lfht_node *node, *triggers_ht_node; + struct cds_lfht_node *triggers_ht_node; struct lttng_channel_trigger_list *trigger_list; struct notification_client_list *client_list; - struct notification_client_list_element *client_list_element, *tmp; struct lttng_trigger_ht_element *trigger_ht_element = NULL; - struct lttng_condition *condition = lttng_trigger_get_condition( + const struct lttng_condition *condition = lttng_trigger_get_const_condition( trigger); - struct lttng_action *action; enum lttng_error_code cmd_reply; rcu_read_lock(); cds_lfht_lookup(state->triggers_ht, lttng_condition_hash(condition), - match_condition, - condition, + match_trigger, + trigger, &iter); triggers_ht_node = cds_lfht_iter_get_node(&iter); if (!triggers_ht_node) { @@ -995,52 +2750,62 @@ int handle_notification_thread_command_unregister_trigger( cds_list_for_each_entry_safe(trigger_element, tmp, &trigger_list->list, node) { - struct lttng_condition *current_condition = - lttng_trigger_get_condition( - trigger_element->trigger); - - assert(current_condition); - if (!lttng_condition_is_equal(condition, - current_condition)) { + if (!lttng_trigger_is_equal(trigger, trigger_element->trigger)) { continue; } 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. - */ - cds_lfht_lookup(state->notification_trigger_clients_ht, - lttng_condition_hash(condition), - match_client_list, - trigger, - &iter); - node = cds_lfht_iter_get_node(&iter); - assert(node); - client_list = caa_container_of(node, struct notification_client_list, - notification_trigger_ht_node); - cds_list_for_each_entry_safe(client_list_element, tmp, - &client_list->list, node) { - free(client_list_element); + if (lttng_condition_get_type(condition) == + LTTNG_CONDITION_TYPE_EVENT_RULE_HIT) { + struct notification_trigger_tokens_ht_element + *trigger_tokens_ht_element; + + cds_lfht_for_each_entry (state->trigger_tokens_ht, &iter, + trigger_tokens_ht_element, node) { + if (!lttng_trigger_is_equal(trigger, + trigger_tokens_ht_element->trigger)) { + continue; + } + + DBG("[notification-thread] Removed trigger from tokens_ht"); + cds_lfht_del(state->trigger_tokens_ht, + &trigger_tokens_ht_element->node); + call_rcu(&trigger_tokens_ht_element->rcu_node, + free_notification_trigger_tokens_ht_element_rcu); + + break; + } + } + + if (is_trigger_action_notify(trigger)) { + /* + * Remove and release the client list from + * notification_trigger_clients_ht. + */ + client_list = get_client_list_from_condition(state, condition); + assert(client_list); + + /* Put new reference and the hashtable's reference. */ + notification_client_list_put(client_list); + notification_client_list_put(client_list); + client_list = NULL; } - cds_lfht_del(state->notification_trigger_clients_ht, node); - free(client_list); /* Remove trigger from triggers_ht. */ trigger_ht_element = caa_container_of(triggers_ht_node, struct lttng_trigger_ht_element, node); + cds_lfht_del(state->triggers_by_name_uid_ht, &trigger_ht_element->node_by_name_uid); cds_lfht_del(state->triggers_ht, triggers_ht_node); - condition = lttng_trigger_get_condition(trigger_ht_element->trigger); - lttng_condition_destroy(condition); - action = lttng_trigger_get_action(trigger_ht_element->trigger); - lttng_action_destroy(action); + /* Release the ownership of the trigger. */ lttng_trigger_destroy(trigger_ht_element->trigger); - free(trigger_ht_element); + call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu); end: rcu_read_unlock(); if (_cmd_reply) { @@ -1058,46 +2823,122 @@ int handle_notification_thread_command( uint64_t counter; struct notification_thread_command *cmd; - /* Read event_fd to put it back into a quiescent state. */ - ret = read(handle->cmd_queue.event_fd, &counter, sizeof(counter)); - if (ret == -1) { + /* 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); + + DBG("[notification-thread] Received `%s` command", + notification_command_type_str(cmd->type)); switch (cmd->type) { case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: - DBG("[notification-thread] Received register trigger command"); - ret = handle_notification_thread_command_register_trigger( - state, cmd->parameters.trigger, + ret = handle_notification_thread_command_register_trigger(state, + cmd->parameters.register_trigger.trigger, &cmd->reply_code); break; case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: - DBG("[notification-thread] Received unregister trigger command"); ret = handle_notification_thread_command_unregister_trigger( - state, cmd->parameters.trigger, + state, + cmd->parameters.unregister_trigger.trigger, &cmd->reply_code); break; case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: - DBG("[notification-thread] Received add channel command"); ret = handle_notification_thread_command_add_channel( - state, &cmd->parameters.add_channel, + 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: + 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_ADD_TRACER_EVENT_SOURCE: + ret = handle_notification_thread_command_add_tracer_event_source( + state, + cmd->parameters.tracer_event_source.tracer_event_source_fd, + cmd->parameters.tracer_event_source.domain, + &cmd->reply_code); + break; + case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE: + ret = handle_notification_thread_command_remove_tracer_event_source( + state, + cmd->parameters.tracer_event_source.tracer_event_source_fd, + &cmd->reply_code); + break; + case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS: + { + struct lttng_triggers *triggers = NULL; + + ret = handle_notification_thread_command_list_triggers( + handle, + state, + cmd->parameters.list_triggers.uid, + &triggers, + &cmd->reply_code); + cmd->reply.list_triggers.triggers = triggers; + ret = 0; + break; + } case NOTIFICATION_COMMAND_TYPE_QUIT: - DBG("[notification-thread] Received quit command"); cmd->reply_code = LTTNG_OK; ret = 1; goto end; + 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; @@ -1107,26 +2948,22 @@ int handle_notification_thread_command( goto error_unlock; } end: - cds_list_del(&cmd->cmd_list_node); - futex_nto1_wake(&cmd->reply_futex); - pthread_mutex_unlock(&handle->cmd_queue.lock); + if (cmd->is_async) { + free(cmd); + cmd = NULL; + } else { + lttng_waiter_wake_up(&cmd->reply_waiter); + } return ret; error_unlock: /* Wake-up and return a fatal error to the calling thread. */ - futex_nto1_wake(&cmd->reply_futex); - pthread_mutex_unlock(&handle->cmd_queue.lock); + lttng_waiter_wake_up(&cmd->reply_waiter); cmd->reply_code = LTTNG_ERR_FATAL; error: /* Indicate a fatal error to the caller. */ return -1; } -static -unsigned long hash_client_socket(int socket) -{ - return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); -} - static int socket_set_non_blocking(int socket) { @@ -1151,21 +2988,24 @@ end: } static -void client_reset_inbound_state(struct notification_client *client) +int client_reset_inbound_state(struct notification_client *client) { int ret; - ret = lttng_dynamic_buffer_set_size( - &client->communication.inbound.buffer, 0); - assert(!ret); + + lttng_payload_clear(&client->communication.inbound.payload); client->communication.inbound.bytes_to_receive = sizeof(struct lttng_notification_channel_message); client->communication.inbound.msg_type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; - client->communication.inbound.receive_creds = false; 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( @@ -1182,10 +3022,20 @@ int handle_notification_thread_client_connect( ret = -1; goto error; } + + pthread_mutex_init(&client->lock, NULL); + client->id = state->next_notification_client_id++; CDS_INIT_LIST_HEAD(&client->condition_list); - lttng_dynamic_buffer_init(&client->communication.inbound.buffer); - lttng_dynamic_buffer_init(&client->communication.outbound.buffer); - client_reset_inbound_state(client); + 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) { @@ -1220,22 +3070,64 @@ int handle_notification_thread_client_connect( DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", client->socket); - /* Add to ht. */ 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: + 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 client_socket, struct notification_thread_state *state) { int ret = 0; struct notification_client *client; @@ -1252,13 +3144,7 @@ int handle_notification_thread_client_disconnect( goto end; } - ret = lttng_poll_del(&state->events, client_socket); - if (ret) { - ERR("[notification-thread] Failed to remove client socket from poll set"); - } - cds_lfht_del(state->client_socket_ht, - &client->client_socket_ht_node); - notification_client_destroy(client, state); + ret = notification_thread_client_disconnect(client, state); end: rcu_read_unlock(); return ret; @@ -1274,11 +3160,11 @@ int handle_notification_thread_client_disconnect_all( rcu_read_lock(); DBG("[notification-thread] Closing all client connections"); cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, - client_socket_ht_node) { + client_socket_ht_node) { int ret; - ret = handle_notification_thread_client_disconnect( - client->socket, state); + ret = notification_thread_client_disconnect( + client, state); if (ret) { error_encoutered = true; } @@ -1290,93 +3176,203 @@ int handle_notification_thread_client_disconnect_all( int handle_notification_thread_trigger_unregister_all( struct notification_thread_state *state) { - bool error_occured = false; + 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_occured = true; + error_occurred = true; } } - return error_occured ? -1 : 0; + rcu_read_unlock(); + return error_occurred ? -1 : 0; } static -int client_flush_outgoing_queue(struct notification_client *client, +int client_handle_transmission_status( + struct notification_client *client, + enum client_transmission_status transmission_status, struct notification_thread_state *state) +{ + int ret = 0; + + switch (transmission_status) { + case CLIENT_TRANSMISSION_STATUS_COMPLETE: + ret = lttng_poll_mod(&state->events, client->socket, + CLIENT_POLL_MASK_IN); + if (ret) { + goto end; + } + + break; + case CLIENT_TRANSMISSION_STATUS_QUEUED: + /* + * We want to be notified whenever there is buffer space + * available to send the rest of the payload. + */ + ret = lttng_poll_mod(&state->events, client->socket, + CLIENT_POLL_MASK_IN_OUT); + if (ret) { + goto end; + } + break; + case CLIENT_TRANSMISSION_STATUS_FAIL: + ret = notification_thread_client_disconnect(client, state); + if (ret) { + goto end; + } + break; + case CLIENT_TRANSMISSION_STATUS_ERROR: + ret = -1; + goto end; + default: + abort(); + } +end: + return ret; +} + +/* Client lock must be acquired by caller. */ +static +enum client_transmission_status client_flush_outgoing_queue( + struct notification_client *client) { ssize_t ret; size_t to_send_count; + enum client_transmission_status status; + struct lttng_payload_view pv = lttng_payload_view_from_payload( + &client->communication.outbound.payload, 0, -1); + const int fds_to_send_count = + lttng_payload_view_get_fd_handle_count(&pv); + + ASSERT_LOCKED(client->lock); + + if (!client->communication.active) { + status = CLIENT_TRANSMISSION_STATUS_FAIL; + goto end; + } + + 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; + } - assert(client->communication.outbound.buffer.size != 0); - to_send_count = client->communication.outbound.buffer.size; + /* Send data. */ + to_send_count = pv.buffer.size; DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", client->socket); ret = lttcomm_send_unix_sock_non_block(client->socket, - client->communication.outbound.buffer.data, + pv.buffer.data, to_send_count); - if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || - (ret > 0 && ret < to_send_count)) { + if ((ret >= 0 && ret < to_send_count)) { DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", client->socket); to_send_count -= max(ret, 0); - memcpy(client->communication.outbound.buffer.data, - client->communication.outbound.buffer.data + - client->communication.outbound.buffer.size - to_send_count, + memmove(client->communication.outbound.payload.buffer.data, + pv.buffer.data + + pv.buffer.size - to_send_count, to_send_count); ret = lttng_dynamic_buffer_set_size( - &client->communication.outbound.buffer, + &client->communication.outbound.payload.buffer, to_send_count); if (ret) { goto error; } - /* - * We want to be notified whenever there is buffer space - * available to send the rest of the payload. - */ - ret = lttng_poll_mod(&state->events, client->socket, - CLIENT_POLL_MASK_IN_OUT); - if (ret) { - goto error; - } + status = CLIENT_TRANSMISSION_STATUS_QUEUED; + goto end; } else if (ret < 0) { - /* Generic error, disconnect the client. */ - ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", + /* Generic error, disable the client's communication. */ + ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)", client->socket); - ret = handle_notification_thread_client_disconnect( - client->socket, state); - if (ret) { - goto error; - } + client->communication.active = false; + status = CLIENT_TRANSMISSION_STATUS_FAIL; + goto end; } else { - /* No error and flushed the queue completely. */ + /* + * No error and flushed the queue completely. + * + * The payload buffer size is used later to + * check if there is notifications queued. So albeit that the + * direct caller knows that the transmission is complete, we + * need to set the buffer size to zero. + */ ret = lttng_dynamic_buffer_set_size( - &client->communication.outbound.buffer, 0); - if (ret) { - goto error; - } - ret = lttng_poll_mod(&state->events, client->socket, - CLIENT_POLL_MASK_IN); + &client->communication.outbound.payload.buffer, 0); if (ret) { goto error; } + } + +send_fds: + /* No fds to send, transmission is complete. */ + if (fds_to_send_count == 0) { + status = CLIENT_TRANSMISSION_STATUS_COMPLETE; + goto end; + } + + ret = lttcomm_send_payload_view_fds_unix_sock_non_block( + client->socket, &pv); + if (ret < 0) { + /* Generic error, disable the client's communication. */ + ERR("[notification-thread] Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)", + client->socket); + client->communication.active = false; + status = CLIENT_TRANSMISSION_STATUS_FAIL; + goto end; + } else if (ret == 0) { + /* Nothing could be sent. */ + status = CLIENT_TRANSMISSION_STATUS_QUEUED; + } else { + /* Fd passing is an all or nothing kind of thing. */ + status = CLIENT_TRANSMISSION_STATUS_COMPLETE; + /* + * The payload _fd_array count is used later to + * check if there is notifications queued. So although the + * direct caller knows that the transmission is complete, we + * need to clear the _fd_array for the queuing check. + */ + lttng_dynamic_pointer_array_clear( + &client->communication.outbound.payload + ._fd_handles); + } +end: + if (status == CLIENT_TRANSMISSION_STATUS_COMPLETE) { client->communication.outbound.queued_command_reply = false; client->communication.outbound.dropped_notification = false; + lttng_payload_clear(&client->communication.outbound.payload); } - return 0; + return status; error: - return -1; + 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, @@ -1391,210 +3387,266 @@ int client_send_command_reply(struct notification_client *client, .size = sizeof(reply), }; char buffer[sizeof(msg) + sizeof(reply)]; - - if (client->communication.outbound.queued_command_reply) { - /* Protocol error. */ - goto error; - } + 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.buffer, + &client->communication.outbound.payload.buffer, buffer, sizeof(buffer)); if (ret) { - goto error; + goto error_unlock; } - ret = client_flush_outgoing_queue(client, state); - if (ret) { - goto error; - } + transmission_status = client_flush_outgoing_queue(client); - if (client->communication.outbound.buffer.size != 0) { + 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_dispatch_message(struct notification_client *client, +int client_handle_message_unknown(struct notification_client *client, struct notification_thread_state *state) { - int ret = 0; + 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; - 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"); + 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 (client->communication.inbound.msg_type) { - case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: - { - /* - * Receiving message header. The function will be called again - * once the rest of the message as been received and can be - * interpreted. - */ - const struct lttng_notification_channel_message *msg; - - assert(sizeof(*msg) == - client->communication.inbound.buffer.size); - msg = (const struct lttng_notification_channel_message *) - client->communication.inbound.buffer.data; + 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; + } - 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; - } + 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); - 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; - } + /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */ + msg = NULL; +end: + return ret; +} - client->communication.inbound.bytes_to_receive = msg->size; - client->communication.inbound.msg_type = - (enum lttng_notification_channel_message_type) msg->type; - if (client->communication.inbound.msg_type == - LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE) { - client->communication.inbound.receive_creds = true; - } - ret = lttng_dynamic_buffer_set_size( - &client->communication.inbound.buffer, 0); - if (ret) { - goto end; - } - break; - } - case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: - { - struct lttng_notification_channel_command_handshake *handshake_client; - struct lttng_notification_channel_command_handshake handshake_reply = { +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, - }; - struct lttng_notification_channel_message msg_header = { + }; + 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.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; - } + }; + 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); + 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; + } - 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; + } - ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, - send_buffer, sizeof(send_buffer)); - if (ret) { - ERR("[notification-thread] Failed to send protocol version to notification channel client"); - goto end; - } + client->validated = true; + client->communication.active = true; + pthread_mutex_unlock(&client->lock); - ret = client_flush_outgoing_queue(client, state); - 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; - } + /* 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; + } - /* Set reception state to receive the next message header. */ - client_reset_inbound_state(client); - client->validated = true; + 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: { - struct lttng_condition *condition; - enum lttng_notification_channel_status status = - LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; - const struct lttng_buffer_view condition_view = - lttng_buffer_view_from_dynamic_buffer( - &client->communication.inbound.buffer, - 0, -1); - size_t expected_condition_size = - client->communication.inbound.buffer.size; - - ret = lttng_condition_create_from_buffer(&condition_view, - &condition); - if (ret != expected_condition_size) { - ERR("[notification-thread] Malformed condition received from client"); - goto end; - } - - if (client->communication.inbound.msg_type == - LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { - /* - * FIXME The current state should be evaluated on - * subscription. - */ - ret = notification_thread_client_subscribe(client, - condition, state, &status); - } else { - ret = notification_thread_client_unsubscribe(client, - condition, state, &status); - } - if (ret) { - goto end; - } - - ret = client_send_command_reply(client, state, status); - if (ret) { - ERR("[notification-thread] Failed to send reply to notification channel client"); - goto end; - } - - /* Set reception state to receive the next message header. */ - client_reset_inbound_state(client); + ret = client_handle_message_subscription(client, + client->communication.inbound.msg_type, state); break; } default: @@ -1608,11 +3660,12 @@ end: int handle_notification_thread_client_in( struct notification_thread_state *state, int socket) { - int ret; + 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. */ @@ -1620,58 +3673,82 @@ int handle_notification_thread_client_in( goto end; } - offset = client->communication.inbound.buffer.size; - ret = lttng_dynamic_buffer_set_size( - &client->communication.inbound.buffer, - client->communication.inbound.bytes_to_receive); - if (ret) { - goto end; - } - - if (client->communication.inbound.receive_creds) { + offset = client->communication.inbound.payload.buffer.size - + client->communication.inbound.bytes_to_receive; + if (client->communication.inbound.expect_creds) { recv_ret = lttcomm_recv_creds_unix_sock(socket, - client->communication.inbound.buffer.data + offset, + client->communication.inbound.payload.buffer.data + offset, client->communication.inbound.bytes_to_receive, &client->communication.inbound.creds); if (recv_ret > 0) { - client->communication.inbound.receive_creds = false; + 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.buffer.data + offset, + client->communication.inbound.payload.buffer.data + offset, client->communication.inbound.bytes_to_receive); } - if (recv_ret < 0) { + if (recv_ret >= 0) { + client->communication.inbound.bytes_to_receive -= recv_ret; + } else { goto error_disconnect_client; } - client->communication.inbound.bytes_to_receive -= recv_ret; - ret = lttng_dynamic_buffer_set_size( - &client->communication.inbound.buffer, - client->communication.inbound.buffer.size - - client->communication.inbound.bytes_to_receive); - if (ret) { + if (client->communication.inbound.bytes_to_receive != 0) { + /* Message incomplete wait for more data. */ + ret = 0; goto end; } - if (client->communication.inbound.bytes_to_receive == 0) { - ret = client_dispatch_message(client, state); - if (ret) { + assert(client->communication.inbound.bytes_to_receive == 0); + + /* Receive fds. */ + if (client->communication.inbound.fds_to_receive != 0) { + ret = lttcomm_recv_payload_fds_unix_sock_non_block( + client->socket, + client->communication.inbound.fds_to_receive, + &client->communication.inbound.payload); + if (ret > 0) { /* - * Only returns an error if this client must be - * disconnected. + * Fds received. non blocking fds passing is all + * or nothing. */ + ssize_t expected_size; + + expected_size = sizeof(int) * + client->communication.inbound + .fds_to_receive; + assert(ret == expected_size); + client->communication.inbound.fds_to_receive = 0; + } else if (ret == 0) { + /* Received nothing. */ + ret = 0; + goto end; + } else { goto error_disconnect_client; } - } else { - goto end; } + + /* At this point the message is complete.*/ + assert(client->communication.inbound.bytes_to_receive == 0 && + client->communication.inbound.fds_to_receive == 0); + ret = client_dispatch_message(client, state); + if (ret) { + /* + * Only returns an error if this client must be + * disconnected. + */ + goto error_disconnect_client; + } + end: + rcu_read_unlock(); return ret; + error_disconnect_client: - ret = handle_notification_thread_client_disconnect(socket, state); - return ret; + ret = notification_thread_client_disconnect(client, state); + goto end; } /* Client ready to receive outgoing data. */ @@ -1680,7 +3757,9 @@ int handle_notification_thread_client_out( { 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. */ @@ -1688,29 +3767,32 @@ int handle_notification_thread_client_out( goto end; } - ret = client_flush_outgoing_queue(client, state); + pthread_mutex_lock(&client->lock); + transmission_status = client_flush_outgoing_queue(client); + 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(struct lttng_condition *condition, - struct channel_state_sample *sample, uint64_t buffer_capacity) +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; - struct lttng_condition_buffer_usage *use_condition = container_of( + const struct lttng_condition_buffer_usage *use_condition = container_of( condition, struct lttng_condition_buffer_usage, parent); - if (!sample) { - goto end; - } - if (use_condition->threshold_bytes.set) { threshold = use_condition->threshold_bytes.value; } else { @@ -1722,7 +3804,7 @@ bool evaluate_buffer_usage_condition(struct lttng_condition *condition, * forego this double-multiplication or it could be performed * as fixed-point math. * - * Note that caching should accomodate the case where the + * Note that caching should accommodates the case where the * condition applies to multiple channels (i.e. don't assume * that all channels matching my_chann* have the same size...) */ @@ -1754,32 +3836,73 @@ bool evaluate_buffer_usage_condition(struct lttng_condition *condition, result = true; } } -end: + return result; } static -int evaluate_condition(struct lttng_condition *condition, +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, - struct notification_thread_state *state, - struct channel_state_sample *previous_sample, - struct channel_state_sample *latest_sample, - uint64_t buffer_capacity) + 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; - bool previous_sample_result; + const bool previous_sample_available = !!previous_sample; + bool previous_sample_result = false; bool latest_sample_result; condition_type = lttng_condition_get_type(condition); - /* No other condition type supported for the moment. */ - assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || - condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); - previous_sample_result = evaluate_buffer_usage_condition(condition, - previous_sample, buffer_capacity); - latest_sample_result = evaluate_buffer_usage_condition(condition, - latest_sample, buffer_capacity); + 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)) { @@ -1792,106 +3915,219 @@ int evaluate_condition(struct lttng_condition *condition, goto end; } - if (evaluation && latest_sample_result) { + 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, - buffer_capacity); - if (!*evaluation) { - ret = -1; - goto end; - } + 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_enqueue_dropped_notification(struct notification_client *client, - struct notification_thread_state *state) +int client_notification_overflow(struct notification_client *client) { - int ret; - struct lttng_notification_channel_message msg = { + int ret = 0; + const struct lttng_notification_channel_message msg = { .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, - .size = 0, }; + ASSERT_LOCKED(client->lock); + + DBG("Dropping notification addressed to client (socket fd = %i)", + client->socket); + if (client->communication.outbound.dropped_notification) { + /* + * The client already has a "notification dropped" message + * in its outgoing queue. Nothing to do since all + * of those messages are coalesced. + */ + goto end; + } + + client->communication.outbound.dropped_notification = true; ret = lttng_dynamic_buffer_append( - &client->communication.outbound.buffer, &msg, + &client->communication.outbound.payload.buffer, &msg, sizeof(msg)); + if (ret) { + PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue", + client->socket); + } +end: return ret; } +static int client_handle_transmission_status_wrapper( + struct notification_client *client, + enum client_transmission_status status, + void *user_data) +{ + return client_handle_transmission_status(client, status, + (struct notification_thread_state *) user_data); +} + static -int send_evaluation_to_clients(struct lttng_trigger *trigger, - struct lttng_evaluation *evaluation, +int send_evaluation_to_clients(const struct lttng_trigger *trigger, + const struct lttng_evaluation *evaluation, struct notification_client_list* client_list, struct notification_thread_state *state, - uid_t channel_uid, gid_t channel_gid) + uid_t object_uid, gid_t object_gid) +{ + const struct lttng_credentials creds = { + .uid = LTTNG_OPTIONAL_INIT_VALUE(object_uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(object_gid), + }; + + return notification_client_list_send_evaluation(client_list, + lttng_trigger_get_const_condition(trigger), evaluation, + lttng_trigger_get_credentials(trigger), + &creds, + client_handle_transmission_status_wrapper, state); +} + +/* + * Permission checks relative to notification channel clients are performed + * here. Notice how object, client, and trigger credentials are involved in + * this check. + * + * The `object` credentials are the credentials associated with the "subject" + * of a condition. For instance, a `rotation completed` condition applies + * to a session. When that condition is met, it will produce an evaluation + * against a session. Hence, in this case, the `object` credentials are the + * credentials of the "subject" session. + * + * The `trigger` credentials are the credentials of the user that registered the + * trigger. + * + * The `client` credentials are the credentials of the user that created a given + * notification channel. + * + * In terms of visibility, it is expected that non-privilieged users can only + * register triggers against "their" objects (their own sessions and + * applications they are allowed to interact with). They can then open a + * notification channel and subscribe to notifications associated with those + * triggers. + * + * As for privilieged users, they can register triggers against the objects of + * other users. They can then subscribe to the notifications associated to their + * triggers. Privilieged users _can't_ subscribe to the notifications of + * triggers owned by other users; they must create their own triggers. + * + * This is more a concern of usability than security. It would be difficult for + * a root user reliably subscribe to a specific set of conditions without + * interference from external users (those could, for instance, unregister + * their triggers). + */ +LTTNG_HIDDEN +int notification_client_list_send_evaluation( + struct notification_client_list *client_list, + const struct lttng_condition *condition, + const struct lttng_evaluation *evaluation, + const struct lttng_credentials *trigger_creds, + const struct lttng_credentials *source_object_creds, + report_client_transmission_result_cb client_report, + void *user_data) { int ret = 0; - struct lttng_dynamic_buffer msg_buffer; + struct lttng_payload msg_payload; struct notification_client_list_element *client_list_element, *tmp; - struct lttng_notification *notification; - struct lttng_condition *condition; - ssize_t expected_notification_size, notification_size; - struct lttng_notification_channel_message msg; - - lttng_dynamic_buffer_init(&msg_buffer); + 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, + }; - condition = lttng_trigger_get_condition(trigger); - assert(condition); + lttng_payload_init(&msg_payload); - notification = lttng_notification_create(condition, evaluation); - if (!notification) { - ret = -1; + ret = lttng_dynamic_buffer_append(&msg_payload.buffer, &msg_header, + sizeof(msg_header)); + if (ret) { goto end; } - expected_notification_size = lttng_notification_serialize(notification, - NULL); - if (expected_notification_size < 0) { - ERR("[notification-thread] Failed to get size of serialized notification"); + ret = lttng_notification_serialize(¬ification, &msg_payload); + if (ret) { + ERR("[notification-thread] Failed to serialize notification"); ret = -1; goto end; } - msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; - msg.size = (uint32_t) expected_notification_size; - ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); - if (ret) { - goto end; - } + /* Update payload size. */ + ((struct lttng_notification_channel_message *) msg_payload.buffer.data) + ->size = (uint32_t)( + msg_payload.buffer.size - sizeof(msg_header)); - ret = lttng_dynamic_buffer_set_size(&msg_buffer, - msg_buffer.size + expected_notification_size); - if (ret) { - goto end; - } + /* Update the payload number of fds. */ + { + const struct lttng_payload_view pv = lttng_payload_view_from_payload( + &msg_payload, 0, -1); - notification_size = lttng_notification_serialize(notification, - msg_buffer.data + sizeof(msg)); - if (notification_size != expected_notification_size) { - ERR("[notification-thread] Failed to serialize notification"); - ret = -1; - goto end; + ((struct lttng_notification_channel_message *) + msg_payload.buffer.data)->fds = (uint32_t) + lttng_payload_view_get_fd_handle_count(&pv); } + pthread_mutex_lock(&client_list->lock); cds_list_for_each_entry_safe(client_list_element, tmp, &client_list->list, node) { + enum client_transmission_status transmission_status; struct notification_client *client = client_list_element->client; - if (client->uid != channel_uid && client->gid != channel_gid && - client->uid != 0) { - /* Client is not allowed to monitor this channel. */ - DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); - continue; + ret = 0; + pthread_mutex_lock(&client->lock); + if (!client->communication.active) { + /* + * Skip inactive client (protocol error or + * disconnecting). + */ + DBG("Skipping client at it is marked as inactive"); + goto skip_client; + } + + if (source_object_creds) { + if (client->uid != lttng_credentials_get_uid(source_object_creds) && + client->gid != lttng_credentials_get_gid(source_object_creds) && + client->uid != 0) { + /* + * Client is not allowed to monitor this + * object. + */ + DBG("[notification-thread] Skipping client at it does not have the object permission to receive notification for this trigger"); + goto skip_client; + } + } + + if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) { + DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); + goto skip_client; } DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", - client->socket, msg_buffer.size); - if (client->communication.outbound.buffer.size) { + client->socket, msg_payload.buffer.size); + + if (client_has_outbound_data_left(client)) { /* * Outgoing data is already buffered for this client; * drop the notification and enqueue a "dropped @@ -1899,35 +4135,135 @@ int send_evaluation_to_clients(struct lttng_trigger *trigger, * notification since the socket spilled-over to the * queue. */ - DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", - client->socket); - if (!client->communication.outbound.dropped_notification) { - client->communication.outbound.dropped_notification = true; - ret = client_enqueue_dropped_notification( - client, state); - if (ret) { - goto end; - } + ret = client_notification_overflow(client); + if (ret) { + /* Fatal error. */ + goto skip_client; } - continue; } - ret = lttng_dynamic_buffer_append_buffer( - &client->communication.outbound.buffer, - &msg_buffer); + ret = lttng_payload_copy(&msg_payload, &client->communication.outbound.payload); if (ret) { - goto end; + /* Fatal error. */ + goto skip_client; } - ret = client_flush_outgoing_queue(client, state); + transmission_status = client_flush_outgoing_queue(client); + pthread_mutex_unlock(&client->lock); + ret = client_report(client, transmission_status, user_data); if (ret) { - goto end; + /* Fatal error. */ + goto end_unlock_list; + } + + continue; + +skip_client: + pthread_mutex_unlock(&client->lock); + if (ret) { + /* Fatal error. */ + goto end_unlock_list; } } ret = 0; + +end_unlock_list: + pthread_mutex_unlock(&client_list->lock); +end: + lttng_payload_reset(&msg_payload); + return ret; +} + +int handle_notification_thread_event_notification(struct notification_thread_state *state, + int notification_pipe_read_fd, + enum lttng_domain_type domain) +{ + int ret; + struct lttng_ust_event_notifier_notification ust_notification; + struct lttng_kernel_event_notifier_notification kernel_notification; + struct cds_lfht_node *node; + struct cds_lfht_iter iter; + struct notification_trigger_tokens_ht_element *element; + enum lttng_action_type action_type; + const struct lttng_action *action; + struct lttng_event_notifier_notification notification; + void *reception_buffer; + size_t reception_size; + + notification.type = domain; + + switch(domain) { + case LTTNG_DOMAIN_UST: + reception_buffer = (void *) &ust_notification; + reception_size = sizeof(ust_notification); + notification.notification.ust = &ust_notification; + break; + case LTTNG_DOMAIN_KERNEL: + reception_buffer = (void *) &kernel_notification; + reception_size = sizeof(kernel_notification); + notification.notification.kernel = &kernel_notification; + break; + default: + abort(); + } + + /* + * The monitoring pipe only holds messages smaller than PIPE_BUF, + * ensuring that read/write of tracer notifications are atomic. + */ + ret = lttng_read(notification_pipe_read_fd, reception_buffer, + reception_size); + if (ret != reception_size) { + PERROR("Failed to read from event source notification pipe: fd = %d, size to read = %zu, ret = %d", + notification_pipe_read_fd, reception_size, ret); + ret = -1; + goto end; + } + + switch(domain) { + case LTTNG_DOMAIN_UST: + notification.token = ust_notification.token; + break; + case LTTNG_DOMAIN_KERNEL: + notification.token = kernel_notification.token; + break; + default: + abort(); + } + + /* Find triggers associated with this token. */ + rcu_read_lock(); + cds_lfht_lookup(state->trigger_tokens_ht, + hash_key_u64(¬ification.token, lttng_ht_seed), + match_trigger_token, ¬ification.token, &iter); + node = cds_lfht_iter_get_node(&iter); + if (caa_likely(!node)) { + /* + * This is not an error, slow consumption of the pipe can lead + * to situations where a trigger is removed but we still get + * tracer notification matching to a previous trigger. + */ + ret = 0; + goto end_unlock; + } + + element = caa_container_of(node, + struct notification_trigger_tokens_ht_element, + node); + + action = lttng_trigger_get_const_action(element->trigger); + action_type = lttng_action_get_type(action); + DBG("Received message from tracer event source: event source fd = %d, token = %" PRIu64 ", action type = '%s'", + notification_pipe_read_fd, notification.token, + lttng_action_type_string(action_type)); + + /* TODO: Perform actions */ + + ret = 0; + +end_unlock: + rcu_read_unlock(); end: - lttng_notification_destroy(notification); - lttng_dynamic_buffer_reset(&msg_buffer); return ret; } @@ -1937,13 +4273,15 @@ int handle_notification_thread_channel_sample( { int ret = 0; struct lttcomm_consumer_channel_monitor_msg sample_msg; - struct channel_state_sample previous_sample, latest_sample; 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, @@ -1962,6 +4300,7 @@ int handle_notification_thread_channel_sample( 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(); @@ -1972,7 +4311,7 @@ int handle_notification_thread_channel_sample( &latest_sample.key, &iter); node = cds_lfht_iter_get_node(&iter); - if (!node) { + 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 @@ -1987,12 +4326,16 @@ int handle_notification_thread_channel_sample( } 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")", - channel_info->channel_name, + 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_name, + channel_info->session_info->name, latest_sample.highest_usage, - latest_sample.lowest_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, @@ -2001,18 +4344,24 @@ int handle_notification_thread_channel_sample( &latest_sample.key, &iter); node = cds_lfht_iter_get_node(&iter); - if (node) { + 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 @@ -2031,8 +4380,15 @@ int handle_notification_thread_channel_sample( 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), @@ -2040,69 +4396,94 @@ int handle_notification_thread_channel_sample( &latest_sample.key, &iter); node = cds_lfht_iter_get_node(&iter); - if (!node) { + if (caa_likely(!node)) { goto end_unlock; } + channel_creds = (typeof(channel_creds)) { + .uid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->gid), + }; + trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, channel_triggers_ht_node); cds_list_for_each_entry(trigger_list_element, &trigger_list->list, - node) { - struct lttng_condition *condition; - struct lttng_action *action; + node) { + const struct lttng_condition *condition; struct lttng_trigger *trigger; - struct notification_client_list *client_list; + 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_condition(trigger); + condition = lttng_trigger_get_const_condition(trigger); assert(condition); - action = lttng_trigger_get_action(trigger); - - /* Notify actions are the only type currently supported. */ - assert(lttng_action_get_type(action) == - LTTNG_ACTION_TYPE_NOTIFY); /* * Check if any client is subscribed to the result of this * evaluation. */ - cds_lfht_lookup(state->notification_trigger_clients_ht, - lttng_condition_hash(condition), - match_client_list, - trigger, - &iter); - node = cds_lfht_iter_get_node(&iter); - assert(node); + client_list = get_client_list_from_condition(state, condition); - client_list = caa_container_of(node, - struct notification_client_list, - notification_trigger_ht_node); - if (cds_list_empty(&client_list->list)) { - /* - * No clients interested in the evaluation's result, - * skip it. - */ - continue; + ret = evaluate_buffer_condition(condition, &evaluation, state, + previous_sample_available ? &previous_sample : NULL, + &latest_sample, + previous_session_consumed_total, + latest_session_consumed_total, + channel_info); + if (caa_unlikely(ret)) { + goto put_list; } - ret = evaluate_condition(condition, &evaluation, state, - previous_sample_available ? &previous_sample : NULL, - &latest_sample, channel_info->capacity); - if (ret) { - goto end_unlock; + if (caa_likely(!evaluation)) { + goto put_list; } - if (!evaluation) { - continue; + if (!lttng_trigger_should_fire(trigger)) { + goto put_list; } - /* Dispatch evaluation result to all clients. */ - ret = send_evaluation_to_clients(trigger_list_element->trigger, - evaluation, client_list, state, - channel_info->uid, channel_info->gid); - if (ret) { - goto end_unlock; + lttng_trigger_fire(trigger); + + /* + * Ownership of `evaluation` transferred to the action executor + * no matter the result. + */ + executor_status = action_executor_enqueue(state->executor, + trigger, evaluation, &channel_creds, + client_list); + evaluation = NULL; + switch (executor_status) { + case ACTION_EXECUTOR_STATUS_OK: + break; + case ACTION_EXECUTOR_STATUS_ERROR: + case ACTION_EXECUTOR_STATUS_INVALID: + /* + * TODO Add trigger identification (name/id) when + * it is added to the API. + */ + ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger"); + ret = -1; + goto put_list; + case ACTION_EXECUTOR_STATUS_OVERFLOW: + /* + * TODO Add trigger identification (name/id) when + * it is added to the API. + * + * Not a fatal error. + */ + WARN("No space left when enqueuing action associated with buffer-condition trigger"); + ret = 0; + goto put_list; + default: + abort(); + } + +put_list: + notification_client_list_put(client_list); + if (caa_unlikely(ret)) { + break; } } end_unlock: