src/bin/lttng-sessiond/agent.h

   1 /*
   2  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   3  * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #ifndef LTTNG_SESSIOND_AGENT_H
  10 #define LTTNG_SESSIOND_AGENT_H
  11
  12 #include <inttypes.h>
  13
  14 #include <common/hashtable/hashtable.h>
  15 #include <lttng/lttng.h>
  16
  17 /* Agent protocol version that is verified during the agent registration. */
  18 #define AGENT_MAJOR_VERSION             2
  19 #define AGENT_MINOR_VERSION             0
  20
  21 /*
  22  * Hash table that contains the agent app created upon registration indexed by
  23  * socket. Global to the session daemon.
  24  */
  25 extern struct lttng_ht *agent_apps_ht_by_sock;
  26
  27 /*
  28  * Hash table that contains the trigger agents by domain */
  29 extern struct lttng_ht *trigger_agents_ht_by_domain;
  30
  31 struct agent_ht_key {
  32         const char *name;
  33         int loglevel_value;
  34         enum lttng_loglevel_type loglevel_type;
  35         const char *filter_expression;
  36 };
  37
  38 /*
  39  * Registration message payload from an agent application. The PID is used to
  40  * find back the corresponding UST app object so both socket can be linked.
  41  */
  42 struct agent_register_msg {
  43         /* This maps to a lttng_domain_type. */
  44         uint32_t domain;
  45         uint32_t pid;
  46         uint32_t major_version;
  47         uint32_t minor_version;
  48 };
  49
  50 /*
  51  * Agent application object created after a successful registration. This
  52  * object is linked to its associated UST app by their PID through hash table
  53  * lookups.
  54  */
  55 struct agent_app {
  56         /*
  57          * PID sent during registration of an agent application.
  58          */
  59         pid_t pid;
  60
  61         /* Domain of the application. */
  62         enum lttng_domain_type domain;
  63
  64         /*
  65          * AGENT TCP socket that was created upon registration.
  66          */
  67         struct lttcomm_sock *sock;
  68
  69         /* Initialized with the AGENT sock value. */
  70         struct lttng_ht_node_ulong node;
  71 };
  72
  73 /*
  74  * Agent event representation.
  75  */
  76 struct agent_event {
  77         /* Name of the event. */
  78         char name[LTTNG_SYMBOL_NAME_LEN];
  79         int loglevel_value;
  80         enum lttng_loglevel_type loglevel_type;
  81
  82         /*
  83          * Tells if the event is enabled or not on the agent.
  84          */
  85         unsigned int enabled:1;
  86
  87         /* Hash table node of the agent domain object. */
  88         struct lttng_ht_node_str node;
  89
  90         /* Filter associated with the event. NULL if none. */
  91         struct lttng_filter_bytecode *filter;
  92         char *filter_expression;
  93         struct lttng_event_exclusion *exclusion;
  94
  95         /*
  96          * Multiple triggers and events can use this agent event.
  97          * The event can only be disabled when the count is zero.
  98          */
  99         unsigned int user_refcount;
 100 };
 101
 102 /*
 103  * Agent object containing events enabled/disabled for it.
 104  */
 105 struct agent {
 106         /*
 107          * This indicates if that domain is being used meaning if at least one
 108          * event has been at some point in time added to it. This is used so when
 109          * listing domains for a session, we can tell or not if the agent is
 110          * actually enabled.
 111          */
 112         unsigned int being_used:1;
 113
 114         /* What domain this agent is. */
 115         enum lttng_domain_type domain;
 116
 117         /* Contains event indexed by name. */
 118         struct lttng_ht *events;
 119
 120         /* Application context list (struct agent_app_ctx). */
 121         struct cds_list_head app_ctx_list;
 122
 123         /* Node used for the hash table indexed by domain type. */
 124         struct lttng_ht_node_u64 node;
 125 };
 126
 127 /* Allocate agent apps hash table */
 128 int agent_app_ht_alloc(void);
 129 /* Clean-up agent apps hash table */
 130 void agent_app_ht_clean(void);
 131
 132 /* Initialize an already allocated agent domain. */
 133 int agent_init(struct agent *agt);
 134 struct agent *agent_create(enum lttng_domain_type domain);
 135 void agent_destroy(struct agent *agt);
 136 void agent_add(struct agent *agt, struct lttng_ht *ht);
 137
 138 /* Agent event API. */
 139 struct agent_event *agent_create_event(const char *name,
 140                 enum lttng_loglevel_type loglevel_type, int loglevel_value,
 141                 struct lttng_filter_bytecode *filter,
 142                 char *filter_expression);
 143 void agent_add_event(struct agent_event *event, struct agent *agt);
 144
 145 struct agent_event *agent_find_event(const char *name,
 146                 enum lttng_loglevel_type loglevel_type,
 147                 int loglevel_value,
 148                 const char *filter_expression,
 149                 struct agent *agt);
 150 void agent_find_events_by_name(const char *name, struct agent *agt,
 151                 struct lttng_ht_iter* iter);
 152 void agent_event_next_duplicate(const char *name,
 153                 struct agent *agt, struct lttng_ht_iter* iter);
 154 void agent_delete_event(struct agent_event *event, struct agent *agt);
 155 void agent_destroy_event(struct agent_event *event);
 156
 157 /* Agent context API.*/
 158 int agent_enable_context(const struct lttng_event_context *ctx,
 159                 enum lttng_domain_type domain);
 160 int agent_add_context(const struct lttng_event_context *ctx,
 161                 struct agent *agt);
 162
 163 /* Agent app API. */
 164 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
 165                 struct lttcomm_sock *sock);
 166 void agent_add_app(struct agent_app *app);
 167 void agent_delete_app(struct agent_app *app);
 168 struct agent_app *agent_find_app_by_sock(int sock);
 169 void agent_destroy_app(struct agent_app *app);
 170 void agent_destroy_app_by_sock(int sock);
 171 int agent_send_registration_done(struct agent_app *app);
 172
 173 /* Agent action API */
 174 int agent_enable_event(struct agent_event *event,
 175                 enum lttng_domain_type domain);
 176 int agent_disable_event(struct agent_event *event,
 177                 enum lttng_domain_type domain);
 178 void agent_update(struct agent *agt, int sock);
 179 int agent_list_events(struct lttng_event **events,
 180                 enum lttng_domain_type domain);
 181
 182 struct agent_event *agent_find_event_by_trigger(
 183                 const struct lttng_trigger *trigger, struct agent *agt);
 184
 185 /* todo: find a better place for this */
 186 struct agent *trigger_find_agent(enum lttng_domain_type domain_type);
 187 void trigger_agent_ht_clean(void);
 188 int trigger_agent_ht_alloc(void);
 189
 190 #endif /* LTTNG_SESSIOND_AGENT_H */