| 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 <common/hashtable/hashtable.hpp> |
| 13 | |
| 14 | #include <lttng/lttng.h> |
| 15 | |
| 16 | #include <inttypes.h> |
| 17 | #include <urcu/urcu.h> |
| 18 | |
| 19 | /* Agent protocol version that is verified during the agent registration. */ |
| 20 | #define AGENT_MAJOR_VERSION 2 |
| 21 | #define AGENT_MINOR_VERSION 0 |
| 22 | |
| 23 | /* |
| 24 | * Hash table that contains the agent app created upon registration indexed by |
| 25 | * socket. Global to the session daemon. |
| 26 | */ |
| 27 | extern struct lttng_ht *the_agent_apps_ht_by_sock; |
| 28 | |
| 29 | /* |
| 30 | * Hash table that contains the trigger agents by domain */ |
| 31 | extern struct lttng_ht *the_trigger_agents_ht_by_domain; |
| 32 | |
| 33 | struct agent_ht_key { |
| 34 | const char *name; |
| 35 | int loglevel_value; |
| 36 | enum lttng_loglevel_type loglevel_type; |
| 37 | const char *filter_expression; |
| 38 | }; |
| 39 | |
| 40 | /* |
| 41 | * Registration message payload from an agent application. The PID is used to |
| 42 | * find back the corresponding UST app object so both socket can be linked. |
| 43 | */ |
| 44 | struct agent_register_msg { |
| 45 | /* This maps to a lttng_domain_type. */ |
| 46 | uint32_t domain; |
| 47 | uint32_t pid; |
| 48 | uint32_t major_version; |
| 49 | uint32_t minor_version; |
| 50 | }; |
| 51 | |
| 52 | /* |
| 53 | * Agent application object created after a successful registration. This |
| 54 | * object is linked to its associated UST app by their PID through hash table |
| 55 | * lookups. |
| 56 | */ |
| 57 | struct agent_app { |
| 58 | /* |
| 59 | * PID sent during registration of an agent application. |
| 60 | */ |
| 61 | pid_t pid; |
| 62 | |
| 63 | /* Domain of the application. */ |
| 64 | enum lttng_domain_type domain; |
| 65 | |
| 66 | /* |
| 67 | * AGENT TCP socket that was created upon registration. |
| 68 | */ |
| 69 | struct lttcomm_sock *sock; |
| 70 | |
| 71 | /* Initialized with the AGENT sock value. */ |
| 72 | struct lttng_ht_node_ulong node; |
| 73 | }; |
| 74 | |
| 75 | /* |
| 76 | * Agent event representation. |
| 77 | * Accesses to this structure are protected by the session list lock. |
| 78 | */ |
| 79 | struct agent_event { |
| 80 | /* Name of the event. */ |
| 81 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 82 | int loglevel_value; |
| 83 | enum lttng_loglevel_type loglevel_type; |
| 84 | |
| 85 | /* |
| 86 | * Tells if the event is enabled or not on the agent. While this can be |
| 87 | * implicitly tested as a boolean, it is in fact a reference count and |
| 88 | * the AGENT_EVENT_IS_ENABLED macro should be used to prevent accidental |
| 89 | * comparisons to non-zero literals (e.g. '1'). |
| 90 | * |
| 91 | * Multiple triggers and events can map to the same agent event as it |
| 92 | * is merely a "filter" in front of a user space tracer enabler. |
| 93 | * |
| 94 | * This count is updated to ensure an event is only disabled when all |
| 95 | * matching enablers are disabled. |
| 96 | */ |
| 97 | unsigned int enabled_count; |
| 98 | |
| 99 | /* Hash table node of the agent domain object. */ |
| 100 | struct lttng_ht_node_str node; |
| 101 | |
| 102 | /* Filter associated with the event. NULL if none. */ |
| 103 | struct lttng_bytecode *filter; |
| 104 | char *filter_expression; |
| 105 | struct lttng_event_exclusion *exclusion; |
| 106 | }; |
| 107 | |
| 108 | #define AGENT_EVENT_IS_ENABLED(agent_event) (!!(agent_event)->enabled_count) |
| 109 | |
| 110 | /* |
| 111 | * Agent object containing events enabled/disabled for a given domain in a |
| 112 | * scope. The scope is typically a session, but can also be "global" in the |
| 113 | * context of event notifiers: see event_notifiers_find_agent(). |
| 114 | */ |
| 115 | struct agent { |
| 116 | /* |
| 117 | * This indicates if that domain is being used meaning if at least one |
| 118 | * event has been at some point in time added to it. This is used so when |
| 119 | * listing domains for a session, we can tell or not if the agent is |
| 120 | * actually enabled. |
| 121 | */ |
| 122 | unsigned int being_used:1; |
| 123 | |
| 124 | /* What domain this agent is. */ |
| 125 | enum lttng_domain_type domain; |
| 126 | |
| 127 | /* Contains event indexed by name. */ |
| 128 | struct lttng_ht *events; |
| 129 | |
| 130 | /* Application context list (struct agent_app_ctx). */ |
| 131 | struct cds_list_head app_ctx_list; |
| 132 | |
| 133 | /* Node used for the hash table indexed by domain type. */ |
| 134 | struct lttng_ht_node_u64 node; |
| 135 | }; |
| 136 | |
| 137 | /* Allocate agent apps hash table */ |
| 138 | int agent_app_ht_alloc(); |
| 139 | /* Clean-up agent apps hash table */ |
| 140 | void agent_app_ht_clean(); |
| 141 | |
| 142 | /* Initialize an already allocated agent domain. */ |
| 143 | int agent_init(struct agent *agt); |
| 144 | struct agent *agent_create(enum lttng_domain_type domain); |
| 145 | void agent_destroy(struct agent *agt); |
| 146 | void agent_add(struct agent *agt, struct lttng_ht *ht); |
| 147 | |
| 148 | /* Agent event API. */ |
| 149 | struct agent_event *agent_create_event(const char *name, |
| 150 | enum lttng_loglevel_type loglevel_type, |
| 151 | int loglevel_value, |
| 152 | struct lttng_bytecode *filter, |
| 153 | char *filter_expression); |
| 154 | void agent_add_event(struct agent_event *event, struct agent *agt); |
| 155 | |
| 156 | struct agent_event *agent_find_event(const char *name, |
| 157 | enum lttng_loglevel_type loglevel_type, |
| 158 | int loglevel_value, |
| 159 | const char *filter_expression, |
| 160 | struct agent *agt); |
| 161 | void agent_find_events_by_name(const char *name, struct agent *agt, struct lttng_ht_iter *iter); |
| 162 | void agent_event_next_duplicate(const char *name, struct agent *agt, struct lttng_ht_iter *iter); |
| 163 | void agent_delete_event(struct agent_event *event, struct agent *agt); |
| 164 | void agent_destroy_event(struct agent_event *event); |
| 165 | |
| 166 | /* Agent context API.*/ |
| 167 | int agent_enable_context(const struct lttng_event_context *ctx, enum lttng_domain_type domain); |
| 168 | int agent_add_context(const struct lttng_event_context *ctx, struct agent *agt); |
| 169 | |
| 170 | /* Agent app API. */ |
| 171 | struct agent_app * |
| 172 | agent_create_app(pid_t pid, enum lttng_domain_type domain, struct lttcomm_sock *sock); |
| 173 | void agent_add_app(struct agent_app *app); |
| 174 | void agent_delete_app(struct agent_app *app); |
| 175 | struct agent_app *agent_find_app_by_sock(int sock); |
| 176 | void agent_destroy_app(struct agent_app *app); |
| 177 | void agent_destroy_app_by_sock(int sock); |
| 178 | int agent_send_registration_done(struct agent_app *app); |
| 179 | |
| 180 | /* Agent action API */ |
| 181 | int agent_enable_event(struct agent_event *event, enum lttng_domain_type domain); |
| 182 | int agent_disable_event(struct agent_event *event, enum lttng_domain_type domain); |
| 183 | void agent_update(const struct agent *agt, const struct agent_app *app); |
| 184 | int agent_list_events(struct lttng_event **events, enum lttng_domain_type domain); |
| 185 | |
| 186 | struct agent_event *agent_find_event_by_trigger(const struct lttng_trigger *trigger, |
| 187 | struct agent *agt); |
| 188 | |
| 189 | /* Global event notifier per-domain agents. */ |
| 190 | struct agent *agent_find_by_event_notifier_domain(enum lttng_domain_type domain_type); |
| 191 | void agent_by_event_notifier_domain_ht_destroy(); |
| 192 | int agent_by_event_notifier_domain_ht_create(); |
| 193 | |
| 194 | #endif /* LTTNG_SESSIOND_AGENT_H */ |