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  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #ifndef LTTNG_SESSIOND_AGENT_H
  20 #define LTTNG_SESSIOND_AGENT_H
  21
  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             2
  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         char *filter_expression;
  42 };
  43
  44 /*
  45  * Registration message payload from an agent application. The PID is used to
  46  * find back the corresponding UST app object so both socket can be linked.
  47  */
  48 struct agent_register_msg {
  49         /* This maps to a lttng_domain_type. */
  50         uint32_t domain;
  51         uint32_t pid;
  52         uint32_t major_version;
  53         uint32_t minor_version;
  54 };
  55
  56 /*
  57  * Agent application object created after a successful registration. This
  58  * object is linked to its associated UST app by their PID through hash table
  59  * lookups.
  60  */
  61 struct agent_app {
  62         /*
  63          * PID sent during registration of an agent application.
  64          */
  65         pid_t pid;
  66
  67         /* Domain of the application. */
  68         enum lttng_domain_type domain;
  69
  70         /*
  71          * AGENT TCP socket that was created upon registration.
  72          */
  73         struct lttcomm_sock *sock;
  74
  75         /* Initialized with the AGENT sock value. */
  76         struct lttng_ht_node_ulong node;
  77 };
  78
  79 /*
  80  * Agent event representation.
  81  */
  82 struct agent_event {
  83         /* Name of the event. */
  84         char name[LTTNG_SYMBOL_NAME_LEN];
  85         int loglevel_value;
  86         enum lttng_loglevel_type loglevel_type;
  87
  88         /*
  89          * Tells if the event is enabled or not on the agent.
  90          */
  91         unsigned int enabled:1;
  92
  93         /* Hash table node of the agent domain object. */
  94         struct lttng_ht_node_str node;
  95
  96         /* Filter associated with the event. NULL if none. */
  97         struct lttng_filter_bytecode *filter;
  98         char *filter_expression;
  99         struct lttng_event_exclusion *exclusion;
 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, int loglevel_value,
 147                 char *filter_expression, struct agent *agt);
 148 void agent_find_events_by_name(const char *name, struct agent *agt,
 149                 struct lttng_ht_iter* iter);
 150 void agent_event_next_duplicate(const char *name,
 151                 struct agent *agt, struct lttng_ht_iter* iter);
 152 void agent_delete_event(struct agent_event *event, struct agent *agt);
 153 void agent_destroy_event(struct agent_event *event);
 154
 155 /* Agent context API.*/
 156 int agent_enable_context(struct lttng_event_context *ctx,
 157                 enum lttng_domain_type domain);
 158 int agent_add_context(struct lttng_event_context *ctx, struct agent *agt);
 159
 160 /* Agent app API. */
 161 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
 162                 struct lttcomm_sock *sock);
 163 void agent_add_app(struct agent_app *app);
 164 void agent_delete_app(struct agent_app *app);
 165 struct agent_app *agent_find_app_by_sock(int sock);
 166 void agent_destroy_app(struct agent_app *app);
 167 void agent_destroy_app_by_sock(int sock);
 168 int agent_send_registration_done(struct agent_app *app);
 169
 170 /* Agent action API */
 171 int agent_enable_event(struct agent_event *event,
 172                 enum lttng_domain_type domain);
 173 int agent_disable_event(struct agent_event *event,
 174                 enum lttng_domain_type domain);
 175 void agent_update(struct agent *agt, int sock);
 176 int agent_list_events(struct lttng_event **events,
 177                 enum lttng_domain_type domain);
 178
 179 #endif /* LTTNG_SESSIOND_AGENT_H */