--- /dev/null
+/*
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#ifndef LTTNG_SESSIOND_AGENT_H
+#define LTTNG_SESSIOND_AGENT_H
+
+#include <inttypes.h>
+
+#include <common/hashtable/hashtable.hpp>
+#include <lttng/lttng.h>
+
+/* Agent protocol version that is verified during the agent registration. */
+#define AGENT_MAJOR_VERSION 2
+#define AGENT_MINOR_VERSION 0
+
+/*
+ * Hash table that contains the agent app created upon registration indexed by
+ * socket. Global to the session daemon.
+ */
+extern struct lttng_ht *the_agent_apps_ht_by_sock;
+
+/*
+ * Hash table that contains the trigger agents by domain */
+extern struct lttng_ht *the_trigger_agents_ht_by_domain;
+
+struct agent_ht_key {
+ const char *name;
+ int loglevel_value;
+ enum lttng_loglevel_type loglevel_type;
+ const char *filter_expression;
+};
+
+/*
+ * Registration message payload from an agent application. The PID is used to
+ * find back the corresponding UST app object so both socket can be linked.
+ */
+struct agent_register_msg {
+ /* This maps to a lttng_domain_type. */
+ uint32_t domain;
+ uint32_t pid;
+ uint32_t major_version;
+ uint32_t minor_version;
+};
+
+/*
+ * Agent application object created after a successful registration. This
+ * object is linked to its associated UST app by their PID through hash table
+ * lookups.
+ */
+struct agent_app {
+ /*
+ * PID sent during registration of an agent application.
+ */
+ pid_t pid;
+
+ /* Domain of the application. */
+ enum lttng_domain_type domain;
+
+ /*
+ * AGENT TCP socket that was created upon registration.
+ */
+ struct lttcomm_sock *sock;
+
+ /* Initialized with the AGENT sock value. */
+ struct lttng_ht_node_ulong node;
+};
+
+/*
+ * Agent event representation.
+ * Accesses to this structure are protected by the session list lock.
+ */
+struct agent_event {
+ /* Name of the event. */
+ char name[LTTNG_SYMBOL_NAME_LEN];
+ int loglevel_value;
+ enum lttng_loglevel_type loglevel_type;
+
+ /*
+ * Tells if the event is enabled or not on the agent. While this can be
+ * implicitly tested as a boolean, it is in fact a reference count and
+ * the AGENT_EVENT_IS_ENABLED macro should be used to prevent accidental
+ * comparisons to non-zero literals (e.g. '1').
+ *
+ * Multiple triggers and events can map to the same agent event as it
+ * is merely a "filter" in front of a user space tracer enabler.
+ *
+ * This count is updated to ensure an event is only disabled when all
+ * matching enablers are disabled.
+ */
+ unsigned int enabled_count;
+
+ /* Hash table node of the agent domain object. */
+ struct lttng_ht_node_str node;
+
+ /* Filter associated with the event. NULL if none. */
+ struct lttng_bytecode *filter;
+ char *filter_expression;
+ struct lttng_event_exclusion *exclusion;
+};
+
+#define AGENT_EVENT_IS_ENABLED(agent_event) (!!agent_event->enabled_count)
+
+/*
+ * Agent object containing events enabled/disabled for a given domain in a
+ * scope. The scope is typically a session, but can also be "global" in the
+ * context of event notifiers: see event_notifiers_find_agent().
+ */
+struct agent {
+ /*
+ * This indicates if that domain is being used meaning if at least one
+ * event has been at some point in time added to it. This is used so when
+ * listing domains for a session, we can tell or not if the agent is
+ * actually enabled.
+ */
+ unsigned int being_used:1;
+
+ /* What domain this agent is. */
+ enum lttng_domain_type domain;
+
+ /* Contains event indexed by name. */
+ struct lttng_ht *events;
+
+ /* Application context list (struct agent_app_ctx). */
+ struct cds_list_head app_ctx_list;
+
+ /* Node used for the hash table indexed by domain type. */
+ struct lttng_ht_node_u64 node;
+};
+
+/* Allocate agent apps hash table */
+int agent_app_ht_alloc(void);
+/* Clean-up agent apps hash table */
+void agent_app_ht_clean(void);
+
+/* Initialize an already allocated agent domain. */
+int agent_init(struct agent *agt);
+struct agent *agent_create(enum lttng_domain_type domain);
+void agent_destroy(struct agent *agt);
+void agent_add(struct agent *agt, struct lttng_ht *ht);
+
+/* Agent event API. */
+struct agent_event *agent_create_event(const char *name,
+ enum lttng_loglevel_type loglevel_type, int loglevel_value,
+ struct lttng_bytecode *filter,
+ char *filter_expression);
+void agent_add_event(struct agent_event *event, struct agent *agt);
+
+struct agent_event *agent_find_event(const char *name,
+ enum lttng_loglevel_type loglevel_type,
+ int loglevel_value,
+ const char *filter_expression,
+ struct agent *agt);
+void agent_find_events_by_name(const char *name, struct agent *agt,
+ struct lttng_ht_iter* iter);
+void agent_event_next_duplicate(const char *name,
+ struct agent *agt, struct lttng_ht_iter* iter);
+void agent_delete_event(struct agent_event *event, struct agent *agt);
+void agent_destroy_event(struct agent_event *event);
+
+/* Agent context API.*/
+int agent_enable_context(const struct lttng_event_context *ctx,
+ enum lttng_domain_type domain);
+int agent_add_context(const struct lttng_event_context *ctx,
+ struct agent *agt);
+
+/* Agent app API. */
+struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
+ struct lttcomm_sock *sock);
+void agent_add_app(struct agent_app *app);
+void agent_delete_app(struct agent_app *app);
+struct agent_app *agent_find_app_by_sock(int sock);
+void agent_destroy_app(struct agent_app *app);
+void agent_destroy_app_by_sock(int sock);
+int agent_send_registration_done(struct agent_app *app);
+
+/* Agent action API */
+int agent_enable_event(struct agent_event *event,
+ enum lttng_domain_type domain);
+int agent_disable_event(struct agent_event *event,
+ enum lttng_domain_type domain);
+void agent_update(const struct agent *agt, const struct agent_app *app);
+int agent_list_events(struct lttng_event **events,
+ enum lttng_domain_type domain);
+
+struct agent_event *agent_find_event_by_trigger(
+ const struct lttng_trigger *trigger, struct agent *agt);
+
+/* Global event notifier per-domain agents. */
+struct agent *agent_find_by_event_notifier_domain(
+ enum lttng_domain_type domain_type);
+void agent_by_event_notifier_domain_ht_destroy(void);
+int agent_by_event_notifier_domain_ht_create(void);
+
+#endif /* LTTNG_SESSIOND_AGENT_H */
projects / lttng-tools.git / blobdiff