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