src/bin/lttng-sessiond/agent.h

   1 /*
   2  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #ifndef LTTNG_SESSIOND_AGENT_H
  19 #define LTTNG_SESSIOND_AGENT_H
  20
  21 #define _GNU_SOURCE
  22 #include <inttypes.h>
  23
  24 #include <common/hashtable/hashtable.h>
  25 #include <lttng/lttng.h>
  26
  27 /* Agent protocol version that is verified during the agent registration. */
  28 #define AGENT_MAJOR_VERSION             1
  29 #define AGENT_MINOR_VERSION             0
  30
  31 /*
  32  * Hash table that contains the agent app created upon registration indexed by
  33  * socket. Global to the session daemon.
  34  */
  35 extern struct lttng_ht *agent_apps_ht_by_sock;
  36
  37 struct agent_ht_key {
  38         const char *name;
  39         int loglevel_value;
  40         enum lttng_loglevel_type loglevel_type;
  41 };
  42
  43 /*
  44  * Registration message payload from an agent application. The PID is used to
  45  * find back the corresponding UST app object so both socket can be linked.
  46  */
  47 struct agent_register_msg {
  48         /* This maps to a lttng_domain_type. */
  49         uint32_t domain;
  50         uint32_t pid;
  51         uint32_t major_version;
  52         uint32_t minor_version;
  53 };
  54
  55 /*
  56  * Agent application object created after a successful registration. This
  57  * object is linked to its associated UST app by their PID through hash table
  58  * lookups.
  59  */
  60 struct agent_app {
  61         /*
  62          * PID sent during registration of an agent application.
  63          */
  64         pid_t pid;
  65
  66         /* Domain of the application. */
  67         enum lttng_domain_type domain;
  68
  69         /*
  70          * AGENT TCP socket that was created upon registration.
  71          */
  72         struct lttcomm_sock *sock;
  73
  74         /* Initialized with the AGENT sock value. */
  75         struct lttng_ht_node_ulong node;
  76 };
  77
  78 /*
  79  * Agent event representation.
  80  */
  81 struct agent_event {
  82         /* Name of the event. */
  83         char name[LTTNG_SYMBOL_NAME_LEN];
  84         int loglevel_value;
  85         enum lttng_loglevel_type loglevel_type;
  86
  87         /*
  88          * Tells if the event is enabled or not on the agent.
  89          */
  90         unsigned int enabled:1;
  91
  92         /* Hash table node of the agent domain object. */
  93         struct lttng_ht_node_str node;
  94
  95         /* Filter associated with the event. NULL if none. */
  96         struct lttng_filter_bytecode *filter;
  97         char *filter_expression;
  98         struct lttng_event_exclusion *exclusion;
  99 };
 100
 101 /*
 102  * Agent object containing events enabled/disabled for it.
 103  */
 104 struct agent {
 105         /*
 106          * This indicates if that domain is being used meaning if at least one
 107          * event has been at some point in time added to it. This is used so when
 108          * listing domains for a session, we can tell or not if the agent is
 109          * actually enabled.
 110          */
 111         unsigned int being_used:1;
 112
 113         /* What domain this agent is. */
 114         enum lttng_domain_type domain;
 115
 116         /* Contains event indexed by name. */
 117         struct lttng_ht *events;
 118
 119         /* Node used for the hash table indexed by domain type. */
 120         struct lttng_ht_node_u64 node;
 121 };
 122
 123 /* Allocate agent apps hash table */
 124 int agent_app_ht_alloc(void);
 125 /* Clean-up agent apps hash table */
 126 void agent_app_ht_clean(void);
 127
 128 /* Initialize an already allocated agent domain. */
 129 int agent_init(struct agent *agt);
 130 struct agent *agent_create(enum lttng_domain_type domain);
 131 void agent_destroy(struct agent *agt);
 132 void agent_add(struct agent *agt, struct lttng_ht *ht);
 133
 134 /* Agent event API. */
 135 struct agent_event *agent_create_event(const char *name,
 136                 enum lttng_loglevel_type loglevel_type, int loglevel_value,
 137                 struct lttng_filter_bytecode *filter,
 138                 char *filter_expression);
 139 void agent_add_event(struct agent_event *event, struct agent *agt);
 140
 141 struct agent_event *agent_find_event(const char *name,
 142                 enum lttng_loglevel_type loglevel_type, int loglevel_value,
 143                 struct agent *agt);
 144 void agent_find_events_by_name(const char *name, struct agent *agt,
 145                 struct lttng_ht_iter* iter);
 146 void agent_event_next_duplicate(const char *name,
 147                 struct agent *agt, struct lttng_ht_iter* iter);
 148 void agent_delete_event(struct agent_event *event, struct agent *agt);
 149 void agent_destroy_event(struct agent_event *event);
 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(struct agent *agt, int sock);
 167 int agent_list_events(struct lttng_event **events,
 168                 enum lttng_domain_type domain);
 169
 170 #endif /* LTTNG_SESSIOND_AGENT_H */