X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fagent.hpp;fp=src%2Fbin%2Flttng-sessiond%2Fagent.hpp;h=2ad42c3f4a6a639e5b8824b414944414c16e0b49;hp=0000000000000000000000000000000000000000;hb=c9e313bc594f40a86eed237dce222c0fc99c957f;hpb=4878de5c7deb512bbdac4fdfc498907efa06fb7c diff --git a/src/bin/lttng-sessiond/agent.hpp b/src/bin/lttng-sessiond/agent.hpp new file mode 100644 index 000000000..2ad42c3f4 --- /dev/null +++ b/src/bin/lttng-sessiond/agent.hpp @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2013 David Goulet + * Copyright (C) 2016 Jérémie Galarneau + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#ifndef LTTNG_SESSIOND_AGENT_H +#define LTTNG_SESSIOND_AGENT_H + +#include + +#include +#include + +/* 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 */