| 1 | /* |
| 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #ifndef LTTNG_TRIGGER_H |
| 9 | #define LTTNG_TRIGGER_H |
| 10 | |
| 11 | #include <sys/types.h> |
| 12 | #include <inttypes.h> |
| 13 | |
| 14 | struct lttng_action; |
| 15 | struct lttng_condition; |
| 16 | struct lttng_trigger; |
| 17 | /* A set of triggers. */ |
| 18 | struct lttng_triggers; |
| 19 | |
| 20 | #ifdef __cplusplus |
| 21 | extern "C" { |
| 22 | #endif |
| 23 | |
| 24 | enum lttng_register_trigger_status { |
| 25 | LTTNG_REGISTER_TRIGGER_STATUS_OK = 0, |
| 26 | LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1, |
| 27 | }; |
| 28 | |
| 29 | enum lttng_trigger_status { |
| 30 | LTTNG_TRIGGER_STATUS_OK = 0, |
| 31 | LTTNG_TRIGGER_STATUS_ERROR = -1, |
| 32 | LTTNG_TRIGGER_STATUS_UNKNOWN = -2, |
| 33 | LTTNG_TRIGGER_STATUS_INVALID = -3, |
| 34 | LTTNG_TRIGGER_STATUS_UNSET = -4, |
| 35 | LTTNG_TRIGGER_STATUS_UNSUPPORTED = -5, |
| 36 | LTTNG_TRIGGER_STATUS_PERMISSION_DENIED = -6, |
| 37 | }; |
| 38 | |
| 39 | enum lttng_trigger_firing_policy { |
| 40 | LTTNG_TRIGGER_FIRING_POLICY_EVERY_N = 0, |
| 41 | LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N = 1, |
| 42 | }; |
| 43 | |
| 44 | /* |
| 45 | * Create a trigger object associating a condition and an action. |
| 46 | * |
| 47 | * A trigger associates a condition and an action to take whenever the |
| 48 | * condition evaluates to true. Such actions can, for example, consist |
| 49 | * in the emission of a notification to clients listening through |
| 50 | * notification channels. |
| 51 | * |
| 52 | * The caller retains the ownership of both the condition and action |
| 53 | * and both must be kept alive for the lifetime of the trigger object. |
| 54 | * |
| 55 | * If the action is a notification action with capture descriptors, |
| 56 | * the condition must be an event rule condition. |
| 57 | * |
| 58 | * A trigger must be registered in order to become activate and can |
| 59 | * be destroyed after its registration. |
| 60 | * |
| 61 | * Returns a trigger object on success, NULL on error. |
| 62 | * Trigger objects must be destroyed using the lttng_trigger_destroy() |
| 63 | * function. |
| 64 | */ |
| 65 | extern struct lttng_trigger *lttng_trigger_create( |
| 66 | struct lttng_condition *condition, struct lttng_action *action); |
| 67 | |
| 68 | /* |
| 69 | * Set the user identity (uid) of a trigger. |
| 70 | * |
| 71 | * Only available for the root user (uid 0). |
| 72 | * |
| 73 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 74 | * LTTNG_TRIGGER_STATUS_EPERM if not authorized, |
| 75 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 76 | */ |
| 77 | extern enum lttng_trigger_status lttng_trigger_set_owner_uid( |
| 78 | struct lttng_trigger *trigger, uid_t uid); |
| 79 | |
| 80 | /* |
| 81 | * Get the user identity (uid) of a trigger. |
| 82 | * |
| 83 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 84 | * LTTNG_TRIGGER_STATUS_UNSET if unset, |
| 85 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 86 | */ |
| 87 | extern enum lttng_trigger_status lttng_trigger_get_owner_uid( |
| 88 | const struct lttng_trigger *trigger, uid_t *uid); |
| 89 | |
| 90 | /* |
| 91 | * Get the condition of a trigger. |
| 92 | * |
| 93 | * The caller acquires no ownership of the returned condition. |
| 94 | * |
| 95 | * Returns a condition on success, NULL on error. |
| 96 | */ |
| 97 | extern struct lttng_condition *lttng_trigger_get_condition( |
| 98 | struct lttng_trigger *trigger); |
| 99 | |
| 100 | const struct lttng_condition *lttng_trigger_get_const_condition( |
| 101 | const struct lttng_trigger *trigger); |
| 102 | |
| 103 | /* |
| 104 | * Get the action of a trigger. |
| 105 | * |
| 106 | * The caller acquires no ownership of the returned action. |
| 107 | * |
| 108 | * Returns an action on success, NULL on error. |
| 109 | */ |
| 110 | extern struct lttng_action *lttng_trigger_get_action( |
| 111 | struct lttng_trigger *trigger); |
| 112 | |
| 113 | const struct lttng_action *lttng_trigger_get_const_action( |
| 114 | const struct lttng_trigger *trigger); |
| 115 | |
| 116 | /* |
| 117 | * Get the name of a trigger. |
| 118 | * |
| 119 | * The caller does not assume the ownership of the returned name. |
| 120 | * The name shall only only be used for the duration of the trigger's |
| 121 | * lifetime, or until a different name is set. |
| 122 | * |
| 123 | * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on |
| 124 | * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed, |
| 125 | * or LTTNG_TRIGGER_STATUS_UNSET if a name was not set prior to this call. |
| 126 | */ |
| 127 | extern enum lttng_trigger_status lttng_trigger_get_name( |
| 128 | const struct lttng_trigger *trigger, const char **name); |
| 129 | |
| 130 | /* |
| 131 | * Set the trigger name. |
| 132 | * |
| 133 | * A name is optional. |
| 134 | * A name will be assigned on trigger registration if no name is set. |
| 135 | * |
| 136 | * The name is copied. |
| 137 | * |
| 138 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 139 | * if invalid parameters are passed. |
| 140 | */ |
| 141 | extern enum lttng_trigger_status lttng_trigger_set_name( |
| 142 | struct lttng_trigger *trigger, const char *name); |
| 143 | |
| 144 | /* |
| 145 | * Set the trigger firing policy. |
| 146 | * |
| 147 | * This is optional. By default a trigger is set to fire each time the |
| 148 | * associated condition occurs. |
| 149 | * |
| 150 | * Threshold is the number of times the condition must be hit before the policy |
| 151 | * is enacted. |
| 152 | * |
| 153 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 154 | * if invalid parameters are passed. |
| 155 | */ |
| 156 | extern enum lttng_trigger_status lttng_trigger_set_firing_policy( |
| 157 | struct lttng_trigger *trigger, |
| 158 | enum lttng_trigger_firing_policy policy_type, |
| 159 | uint64_t threshold); |
| 160 | |
| 161 | /* |
| 162 | * Get the trigger firing policy. |
| 163 | * |
| 164 | * Threshold is the number of time the condition must be hit before the policy is |
| 165 | * enacted. |
| 166 | * |
| 167 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 168 | * if invalid parameters are passed. |
| 169 | */ |
| 170 | extern enum lttng_trigger_status lttng_trigger_get_firing_policy( |
| 171 | const struct lttng_trigger *trigger, |
| 172 | enum lttng_trigger_firing_policy *policy_type, |
| 173 | uint64_t *threshold); |
| 174 | |
| 175 | /* |
| 176 | * Destroy (frees) a trigger object. |
| 177 | */ |
| 178 | extern void lttng_trigger_destroy(struct lttng_trigger *trigger); |
| 179 | |
| 180 | /* |
| 181 | * Register a trigger to the session daemon. |
| 182 | * |
| 183 | * The trigger can be destroyed after this call. |
| 184 | * |
| 185 | * Return 0 on success, a negative LTTng error code on error. |
| 186 | */ |
| 187 | extern int lttng_register_trigger(struct lttng_trigger *trigger); |
| 188 | |
| 189 | /* |
| 190 | * Unregister a trigger from the session daemon. |
| 191 | * |
| 192 | * The trigger can be destroyed after this call. |
| 193 | * |
| 194 | * Return 0 on success, a negative LTTng error code on error. |
| 195 | */ |
| 196 | extern int lttng_unregister_trigger(const struct lttng_trigger *trigger); |
| 197 | |
| 198 | /* |
| 199 | * List triggers for the current user. |
| 200 | * |
| 201 | * On success, a newly-allocated trigger set is returned. |
| 202 | * |
| 203 | * The trigger set must be destroyed by the caller (see |
| 204 | * lttng_triggers_destroy()). |
| 205 | * |
| 206 | * Returns LTTNG_OK on success, else a suitable LTTng error code. |
| 207 | */ |
| 208 | extern enum lttng_error_code lttng_list_triggers( |
| 209 | struct lttng_triggers **triggers); |
| 210 | |
| 211 | /* |
| 212 | * Get a trigger from the set at a given index. |
| 213 | * |
| 214 | * Note that the trigger set maintains the ownership of the returned trigger. |
| 215 | * It must not be destroyed by the user, nor should a reference to it be held |
| 216 | * beyond the lifetime of the trigger set. |
| 217 | * |
| 218 | * Returns a trigger, or NULL on error. |
| 219 | */ |
| 220 | extern const struct lttng_trigger *lttng_triggers_get_at_index( |
| 221 | const struct lttng_triggers *triggers, unsigned int index); |
| 222 | |
| 223 | /* |
| 224 | * Get the number of triggers in a trigger set. |
| 225 | * |
| 226 | * Return LTTNG_TRIGGER_STATUS_OK on success, |
| 227 | * LTTNG_TRIGGER_STATUS_INVALID when invalid parameters are passed. |
| 228 | */ |
| 229 | extern enum lttng_trigger_status lttng_triggers_get_count( |
| 230 | const struct lttng_triggers *triggers, unsigned int *count); |
| 231 | |
| 232 | /* |
| 233 | * Destroy a trigger set. |
| 234 | */ |
| 235 | extern void lttng_triggers_destroy(struct lttng_triggers *triggers); |
| 236 | |
| 237 | |
| 238 | #ifdef __cplusplus |
| 239 | } |
| 240 | #endif |
| 241 | |
| 242 | #endif /* LTTNG_TRIGGER_H */ |