| 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 | /* |
| 40 | * Create a trigger object associating a condition and an action. |
| 41 | * |
| 42 | * A trigger associates a condition and an action to take whenever the |
| 43 | * condition evaluates to true. Such actions can, for example, consist |
| 44 | * in the emission of a notification to clients listening through |
| 45 | * notification channels. |
| 46 | * |
| 47 | * Prior to 2.13, the caller had to retain the ownership of both the condition |
| 48 | * and action. Both objects had to be kept alive for the lifetime of the trigger |
| 49 | * object. This is no longer the case as the condition and action objects are |
| 50 | * internally reference counted. It is safe to destroy a condition and an action |
| 51 | * after using them to create a trigger. However, they should no longer be used. |
| 52 | * |
| 53 | * If the action is a notification action with capture descriptors, |
| 54 | * the condition must be an event rule condition. |
| 55 | * |
| 56 | * A trigger must be registered in order to become activate and can |
| 57 | * be destroyed after its registration. |
| 58 | * |
| 59 | * Returns a trigger object on success, NULL on error. |
| 60 | * Trigger objects must be destroyed using the lttng_trigger_destroy() |
| 61 | * function. |
| 62 | */ |
| 63 | extern struct lttng_trigger *lttng_trigger_create( |
| 64 | struct lttng_condition *condition, struct lttng_action *action); |
| 65 | |
| 66 | /* |
| 67 | * Set the user identity (uid) of a trigger. |
| 68 | * |
| 69 | * Only available for the root user (uid 0). |
| 70 | * |
| 71 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 72 | * LTTNG_TRIGGER_STATUS_EPERM if not authorized, |
| 73 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 74 | */ |
| 75 | extern enum lttng_trigger_status lttng_trigger_set_owner_uid( |
| 76 | struct lttng_trigger *trigger, uid_t uid); |
| 77 | |
| 78 | /* |
| 79 | * Get the user identity (uid) of a trigger. |
| 80 | * |
| 81 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 82 | * LTTNG_TRIGGER_STATUS_UNSET if unset, |
| 83 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 84 | */ |
| 85 | extern enum lttng_trigger_status lttng_trigger_get_owner_uid( |
| 86 | const struct lttng_trigger *trigger, uid_t *uid); |
| 87 | |
| 88 | /* |
| 89 | * Get the condition of a trigger. |
| 90 | * |
| 91 | * The caller acquires no ownership of the returned condition. |
| 92 | * |
| 93 | * Returns a condition on success, NULL on error. |
| 94 | */ |
| 95 | extern struct lttng_condition *lttng_trigger_get_condition( |
| 96 | struct lttng_trigger *trigger); |
| 97 | |
| 98 | const struct lttng_condition *lttng_trigger_get_const_condition( |
| 99 | const struct lttng_trigger *trigger); |
| 100 | |
| 101 | /* |
| 102 | * Get the action of a trigger. |
| 103 | * |
| 104 | * The caller acquires no ownership of the returned action. |
| 105 | * |
| 106 | * Returns an action on success, NULL on error. |
| 107 | */ |
| 108 | extern struct lttng_action *lttng_trigger_get_action( |
| 109 | struct lttng_trigger *trigger); |
| 110 | |
| 111 | const struct lttng_action *lttng_trigger_get_const_action( |
| 112 | const struct lttng_trigger *trigger); |
| 113 | |
| 114 | /* |
| 115 | * Get the name of a trigger. |
| 116 | * |
| 117 | * The caller does not assume the ownership of the returned name. |
| 118 | * The name shall only only be used for the duration of the trigger's |
| 119 | * lifetime, or until a different name is set. |
| 120 | * |
| 121 | * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on |
| 122 | * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed, |
| 123 | * or LTTNG_TRIGGER_STATUS_UNSET if a name was not set prior to this call. |
| 124 | */ |
| 125 | extern enum lttng_trigger_status lttng_trigger_get_name( |
| 126 | const struct lttng_trigger *trigger, const char **name); |
| 127 | |
| 128 | /* |
| 129 | * Set the trigger name. |
| 130 | * |
| 131 | * A name is optional. |
| 132 | * A name will be assigned on trigger registration if no name is set. |
| 133 | * |
| 134 | * The name is copied. |
| 135 | * |
| 136 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 137 | * if invalid parameters are passed. |
| 138 | */ |
| 139 | extern enum lttng_trigger_status lttng_trigger_set_name( |
| 140 | struct lttng_trigger *trigger, const char *name); |
| 141 | |
| 142 | /* |
| 143 | * Destroy (frees) a trigger object. |
| 144 | */ |
| 145 | extern void lttng_trigger_destroy(struct lttng_trigger *trigger); |
| 146 | |
| 147 | /* |
| 148 | * Register a trigger to the session daemon. |
| 149 | * |
| 150 | * The trigger can be destroyed after this call. |
| 151 | * |
| 152 | * Return 0 on success, a negative LTTng error code on error. |
| 153 | */ |
| 154 | extern int lttng_register_trigger(struct lttng_trigger *trigger); |
| 155 | |
| 156 | /* |
| 157 | * Unregister a trigger from the session daemon. |
| 158 | * |
| 159 | * The trigger can be destroyed after this call. |
| 160 | * |
| 161 | * Return 0 on success, a negative LTTng error code on error. |
| 162 | */ |
| 163 | extern int lttng_unregister_trigger(const struct lttng_trigger *trigger); |
| 164 | |
| 165 | /* |
| 166 | * List triggers for the current user. |
| 167 | * |
| 168 | * On success, a newly-allocated trigger set is returned. |
| 169 | * |
| 170 | * The trigger set must be destroyed by the caller (see |
| 171 | * lttng_triggers_destroy()). |
| 172 | * |
| 173 | * Returns LTTNG_OK on success, else a suitable LTTng error code. |
| 174 | */ |
| 175 | extern enum lttng_error_code lttng_list_triggers( |
| 176 | struct lttng_triggers **triggers); |
| 177 | |
| 178 | /* |
| 179 | * Get a trigger from the set at a given index. |
| 180 | * |
| 181 | * Note that the trigger set maintains the ownership of the returned trigger. |
| 182 | * It must not be destroyed by the user, nor should a reference to it be held |
| 183 | * beyond the lifetime of the trigger set. |
| 184 | * |
| 185 | * Returns a trigger, or NULL on error. |
| 186 | */ |
| 187 | extern const struct lttng_trigger *lttng_triggers_get_at_index( |
| 188 | const struct lttng_triggers *triggers, unsigned int index); |
| 189 | |
| 190 | /* |
| 191 | * Get the number of triggers in a trigger set. |
| 192 | * |
| 193 | * Return LTTNG_TRIGGER_STATUS_OK on success, |
| 194 | * LTTNG_TRIGGER_STATUS_INVALID when invalid parameters are passed. |
| 195 | */ |
| 196 | extern enum lttng_trigger_status lttng_triggers_get_count( |
| 197 | const struct lttng_triggers *triggers, unsigned int *count); |
| 198 | |
| 199 | /* |
| 200 | * Destroy a trigger set. |
| 201 | */ |
| 202 | extern void lttng_triggers_destroy(struct lttng_triggers *triggers); |
| 203 | |
| 204 | |
| 205 | #ifdef __cplusplus |
| 206 | } |
| 207 | #endif |
| 208 | |
| 209 | #endif /* LTTNG_TRIGGER_H */ |