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 struct agent_ht_key {
  28         const char *name;
  29         int loglevel_value;
  30         enum lttng_loglevel_type loglevel_type;
  31         char *filter_expression;
  32 };
  33
  34 /*
  35  * Registration message payload from an agent application. The PID is used to
  36  * find back the corresponding UST app object so both socket can be linked.
  37  */
  38 struct agent_register_msg {
  39         /* This maps to a lttng_domain_type. */
  40         uint32_t domain;
  41         uint32_t pid;
  42         uint32_t major_version;
  43         uint32_t minor_version;
  44 };
  45
  46 /*
  47  * Agent application object created after a successful registration. This
  48  * object is linked to its associated UST app by their PID through hash table
  49  * lookups.
  50  */
  51 struct agent_app {
  52         /*
  53          * PID sent during registration of an agent application.
  54          */
  55         pid_t pid;
  56
  57         /* Domain of the application. */
  58         enum lttng_domain_type domain;
  59
  60         /*
  61          * AGENT TCP socket that was created upon registration.
  62          */
  63         struct lttcomm_sock *sock;
  64
  65         /* Initialized with the AGENT sock value. */
  66         struct lttng_ht_node_ulong node;
  67 };
  68
  69 /*
  70  * Agent event representation.
  71  */
  72 struct agent_event {
  73         /* Name of the event. */
  74         char name[LTTNG_SYMBOL_NAME_LEN];
  75         int loglevel_value;
  76         enum lttng_loglevel_type loglevel_type;
  77
  78         /*
  79          * Tells if the event is enabled or not on the agent.
  80          */
  81         unsigned int enabled:1;
  82
  83         /* Hash table node of the agent domain object. */
  84         struct lttng_ht_node_str node;
  85
  86         /* Filter associated with the event. NULL if none. */
  87         struct lttng_filter_bytecode *filter;
  88         char *filter_expression;
  89         struct lttng_event_exclusion *exclusion;
  90 };
  91
  92 /*
  93  * Agent object containing events enabled/disabled for it.
  94  */
  95 struct agent {
  96         /*
  97          * This indicates if that domain is being used meaning if at least one
  98          * event has been at some point in time added to it. This is used so when
  99          * listing domains for a session, we can tell or not if the agent is
 100          * actually enabled.
 101          */
 102         unsigned int being_used:1;
 103
 104         /* What domain this agent is. */
 105         enum lttng_domain_type domain;
 106
 107         /* Contains event indexed by name. */
 108         struct lttng_ht *events;
 109
 110         /* Application context list (struct agent_app_ctx). */
 111         struct cds_list_head app_ctx_list;
 112
 113         /* Node used for the hash table indexed by domain type. */
 114         struct lttng_ht_node_u64 node;
 115 };
 116
 117 /* Allocate agent apps hash table */
 118 int agent_app_ht_alloc(void);
 119 /* Clean-up agent apps hash table */
 120 void agent_app_ht_clean(void);
 121
 122 /* Initialize an already allocated agent domain. */
 123 int agent_init(struct agent *agt);
 124 struct agent *agent_create(enum lttng_domain_type domain);
 125 void agent_destroy(struct agent *agt);
 126 void agent_add(struct agent *agt, struct lttng_ht *ht);
 127
 128 /* Agent event API. */
 129 struct agent_event *agent_create_event(const char *name,
 130                 enum lttng_loglevel_type loglevel_type, int loglevel_value,
 131                 struct lttng_filter_bytecode *filter,
 132                 char *filter_expression);
 133 void agent_add_event(struct agent_event *event, struct agent *agt);
 134
 135 struct agent_event *agent_find_event(const char *name,
 136                 enum lttng_loglevel_type loglevel_type, int loglevel_value,
 137                 char *filter_expression, struct agent *agt);
 138 void agent_find_events_by_name(const char *name, struct agent *agt,
 139                 struct lttng_ht_iter* iter);
 140 void agent_event_next_duplicate(const char *name,
 141                 struct agent *agt, struct lttng_ht_iter* iter);
 142 void agent_delete_event(struct agent_event *event, struct agent *agt);
 143 void agent_destroy_event(struct agent_event *event);
 144
 145 /* Agent context API.*/
 146 int agent_enable_context(const struct lttng_event_context *ctx,
 147                 enum lttng_domain_type domain);
 148 int agent_add_context(const struct lttng_event_context *ctx,
 149                 struct agent *agt);
 150
 151 /* Agent app API. */
 152 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
 153                 struct lttcomm_sock *sock);
 154 void agent_add_app(struct agent_app *app);
 155 void agent_delete_app(struct agent_app *app);
 156 struct agent_app *agent_find_app_by_sock(int sock);
 157 void agent_destroy_app(struct agent_app *app);
 158 void agent_destroy_app_by_sock(int sock);
 159 int agent_send_registration_done(struct agent_app *app);
 160
 161 /* Agent action API */
 162 int agent_enable_event(struct agent_event *event,
 163                 enum lttng_domain_type domain);
 164 int agent_disable_event(struct agent_event *event,
 165                 enum lttng_domain_type domain);
 166 void agent_update(const struct agent *agt, const struct agent_app *app);
 167 int agent_list_events(struct lttng_event **events,
 168                 enum lttng_domain_type domain);
 169
 170 #endif /* LTTNG_SESSIOND_AGENT_H */