| 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 <lttng/constant.h> |
| 12 | #include <lttng/lttng-error.h> |
| 13 | #include <lttng/lttng-export.h> |
| 14 | |
| 15 | #include <inttypes.h> |
| 16 | #include <sys/types.h> |
| 17 | |
| 18 | struct lttng_action; |
| 19 | struct lttng_condition; |
| 20 | struct lttng_trigger; |
| 21 | /* A set of triggers. */ |
| 22 | struct lttng_triggers; |
| 23 | |
| 24 | #ifdef __cplusplus |
| 25 | extern "C" { |
| 26 | #endif |
| 27 | |
| 28 | enum lttng_register_trigger_status { |
| 29 | LTTNG_REGISTER_TRIGGER_STATUS_OK = 0, |
| 30 | LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1, |
| 31 | }; |
| 32 | |
| 33 | enum lttng_trigger_status { |
| 34 | LTTNG_TRIGGER_STATUS_OK = 0, |
| 35 | LTTNG_TRIGGER_STATUS_ERROR = -1, |
| 36 | LTTNG_TRIGGER_STATUS_UNKNOWN = -2, |
| 37 | LTTNG_TRIGGER_STATUS_INVALID = -3, |
| 38 | LTTNG_TRIGGER_STATUS_UNSET = -4, |
| 39 | LTTNG_TRIGGER_STATUS_UNSUPPORTED = -5, |
| 40 | LTTNG_TRIGGER_STATUS_PERMISSION_DENIED = -6, |
| 41 | }; |
| 42 | |
| 43 | /* |
| 44 | * Create a trigger object associating a condition and an action. |
| 45 | * |
| 46 | * A trigger associates a condition and an action to take whenever the |
| 47 | * condition evaluates to true. Such actions can, for example, consist |
| 48 | * in the emission of a notification to clients listening through |
| 49 | * notification channels. |
| 50 | * |
| 51 | * Prior to 2.13, the caller had to retain the ownership of both the condition |
| 52 | * and action. Both objects had to be kept alive for the lifetime of the trigger |
| 53 | * object. This is no longer the case as the condition and action objects are |
| 54 | * internally reference counted. It is safe to destroy a condition and an action |
| 55 | * after using them to create a trigger. However, they should no longer be used. |
| 56 | * |
| 57 | * If the action is a notification action with capture descriptors, |
| 58 | * the condition must be an event rule condition. |
| 59 | * |
| 60 | * A trigger must be registered in order to become activate and can |
| 61 | * be destroyed after its registration. |
| 62 | * |
| 63 | * Returns a trigger object on success, NULL on error. |
| 64 | * Trigger objects must be destroyed using the lttng_trigger_destroy() |
| 65 | * function. |
| 66 | */ |
| 67 | LTTNG_EXPORT extern struct lttng_trigger *lttng_trigger_create(struct lttng_condition *condition, |
| 68 | struct lttng_action *action); |
| 69 | |
| 70 | /* |
| 71 | * Set the user identity (uid) of a trigger. |
| 72 | * |
| 73 | * Only available for the root user (uid 0). |
| 74 | * |
| 75 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 76 | * LTTNG_TRIGGER_STATUS_EPERM if not authorized, |
| 77 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 78 | */ |
| 79 | LTTNG_EXPORT extern enum lttng_trigger_status |
| 80 | lttng_trigger_set_owner_uid(struct lttng_trigger *trigger, uid_t uid); |
| 81 | |
| 82 | /* |
| 83 | * Get the user identity (uid) of a trigger. |
| 84 | * |
| 85 | * Returns LTTNG_TRIGGER_STATUS_OK on success, |
| 86 | * LTTNG_TRIGGER_STATUS_UNSET if unset, |
| 87 | * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. |
| 88 | */ |
| 89 | LTTNG_EXPORT extern enum lttng_trigger_status |
| 90 | lttng_trigger_get_owner_uid(const struct lttng_trigger *trigger, uid_t *uid); |
| 91 | |
| 92 | /* |
| 93 | * Get the condition of a trigger. |
| 94 | * |
| 95 | * The caller acquires no ownership of the returned condition. |
| 96 | * |
| 97 | * Returns a condition on success, NULL on error. |
| 98 | */ |
| 99 | LTTNG_EXPORT extern struct lttng_condition * |
| 100 | lttng_trigger_get_condition(struct lttng_trigger *trigger); |
| 101 | |
| 102 | LTTNG_EXPORT extern const struct lttng_condition * |
| 103 | lttng_trigger_get_const_condition(const struct lttng_trigger *trigger); |
| 104 | |
| 105 | /* |
| 106 | * Get the action of a trigger. |
| 107 | * |
| 108 | * The caller acquires no ownership of the returned action. |
| 109 | * |
| 110 | * Returns an action on success, NULL on error. |
| 111 | */ |
| 112 | LTTNG_EXPORT extern struct lttng_action *lttng_trigger_get_action(struct lttng_trigger *trigger); |
| 113 | |
| 114 | LTTNG_EXPORT extern const struct lttng_action * |
| 115 | lttng_trigger_get_const_action(const struct lttng_trigger *trigger); |
| 116 | |
| 117 | /* |
| 118 | * Get the name of a trigger. |
| 119 | * |
| 120 | * The caller does not assume the ownership of the returned name. |
| 121 | * The name shall only only be used for the duration of the trigger's |
| 122 | * lifetime, or until a different name is set. |
| 123 | * |
| 124 | * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on |
| 125 | * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed, |
| 126 | * or LTTNG_TRIGGER_STATUS_UNSET if the trigger is unnamed. |
| 127 | */ |
| 128 | LTTNG_EXPORT extern enum lttng_trigger_status |
| 129 | lttng_trigger_get_name(const struct lttng_trigger *trigger, const char **name); |
| 130 | |
| 131 | /* |
| 132 | * Destroy (frees) a trigger object. |
| 133 | */ |
| 134 | LTTNG_EXPORT extern void lttng_trigger_destroy(struct lttng_trigger *trigger); |
| 135 | |
| 136 | /* |
| 137 | * Register a trigger to the session daemon with a given name. |
| 138 | * |
| 139 | * The trigger object can be destroyed after this call. |
| 140 | * On success, this function will set the trigger's name to `name`. |
| 141 | * |
| 142 | * Returns an LTTng status code. |
| 143 | */ |
| 144 | LTTNG_EXPORT extern enum lttng_error_code |
| 145 | lttng_register_trigger_with_name(struct lttng_trigger *trigger, const char *name); |
| 146 | |
| 147 | /* |
| 148 | * Register a trigger to the session daemon, generating a unique name for its |
| 149 | * owner. |
| 150 | * |
| 151 | * The trigger can be destroyed after this call. |
| 152 | * On success, this function will set the trigger's name to the generated |
| 153 | * name. |
| 154 | * |
| 155 | * Returns an LTTng status code. |
| 156 | */ |
| 157 | LTTNG_EXPORT extern enum lttng_error_code |
| 158 | lttng_register_trigger_with_automatic_name(struct lttng_trigger *trigger); |
| 159 | |
| 160 | /* |
| 161 | * Unregister a trigger from the session daemon. |
| 162 | * |
| 163 | * The trigger can be destroyed after this call. |
| 164 | * |
| 165 | * Return 0 on success, a negative LTTng error code on error. |
| 166 | */ |
| 167 | LTTNG_EXPORT extern int lttng_unregister_trigger(const struct lttng_trigger *trigger); |
| 168 | |
| 169 | /* |
| 170 | * List triggers for the current user. |
| 171 | * |
| 172 | * On success, a newly-allocated trigger set is returned. |
| 173 | * |
| 174 | * The trigger set must be destroyed by the caller (see |
| 175 | * lttng_triggers_destroy()). |
| 176 | * |
| 177 | * Returns LTTNG_OK on success, else a suitable LTTng error code. |
| 178 | */ |
| 179 | LTTNG_EXPORT extern enum lttng_error_code lttng_list_triggers(struct lttng_triggers **triggers); |
| 180 | |
| 181 | /* |
| 182 | * Get a trigger from the set at a given index. |
| 183 | * |
| 184 | * Note that the trigger set maintains the ownership of the returned trigger. |
| 185 | * It must not be destroyed by the user, nor should a reference to it be held |
| 186 | * beyond the lifetime of the trigger set. |
| 187 | * |
| 188 | * Returns a trigger, or NULL on error. |
| 189 | */ |
| 190 | LTTNG_EXPORT extern const struct lttng_trigger * |
| 191 | lttng_triggers_get_at_index(const struct lttng_triggers *triggers, unsigned int index); |
| 192 | |
| 193 | /* |
| 194 | * Get the number of triggers in a trigger set. |
| 195 | * |
| 196 | * Return LTTNG_TRIGGER_STATUS_OK on success, |
| 197 | * LTTNG_TRIGGER_STATUS_INVALID when invalid parameters are passed. |
| 198 | */ |
| 199 | LTTNG_EXPORT extern enum lttng_trigger_status |
| 200 | lttng_triggers_get_count(const struct lttng_triggers *triggers, unsigned int *count); |
| 201 | |
| 202 | /* |
| 203 | * Destroy a trigger set. |
| 204 | */ |
| 205 | LTTNG_EXPORT extern void lttng_triggers_destroy(struct lttng_triggers *triggers); |
| 206 | |
| 207 | /* |
| 208 | * Deprecated: invocations should be replaced by |
| 209 | * lttng_register_trigger_with_automatic_name(). |
| 210 | * |
| 211 | * Register a trigger to the session daemon. |
| 212 | * |
| 213 | * The trigger can be destroyed after this call. |
| 214 | * |
| 215 | * Return 0 on success, a negative LTTng error code on error. |
| 216 | */ |
| 217 | LTTNG_DEPRECATED("Use lttng_register_trigger_with_automatic_name") |
| 218 | LTTNG_EXPORT extern int lttng_register_trigger(struct lttng_trigger *trigger); |
| 219 | |
| 220 | #ifdef __cplusplus |
| 221 | } |
| 222 | #endif |
| 223 | |
| 224 | #endif /* LTTNG_TRIGGER_H */ |