| 1 | /* |
| 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <lttng/trigger/trigger-internal.h> |
| 9 | #include <lttng/condition/condition-internal.h> |
| 10 | #include <lttng/action/action-internal.h> |
| 11 | #include <common/credentials.h> |
| 12 | #include <common/payload.h> |
| 13 | #include <common/payload-view.h> |
| 14 | #include <common/error.h> |
| 15 | #include <common/optional.h> |
| 16 | #include <assert.h> |
| 17 | |
| 18 | LTTNG_HIDDEN |
| 19 | bool lttng_trigger_validate(struct lttng_trigger *trigger) |
| 20 | { |
| 21 | bool valid; |
| 22 | |
| 23 | if (!trigger) { |
| 24 | valid = false; |
| 25 | goto end; |
| 26 | } |
| 27 | |
| 28 | if (!trigger->creds.uid.is_set) { |
| 29 | valid = false; |
| 30 | goto end; |
| 31 | } |
| 32 | |
| 33 | valid = lttng_condition_validate(trigger->condition) && |
| 34 | lttng_action_validate(trigger->action); |
| 35 | end: |
| 36 | return valid; |
| 37 | } |
| 38 | |
| 39 | struct lttng_trigger *lttng_trigger_create( |
| 40 | struct lttng_condition *condition, |
| 41 | struct lttng_action *action) |
| 42 | { |
| 43 | struct lttng_trigger *trigger = NULL; |
| 44 | |
| 45 | if (!condition || !action) { |
| 46 | goto end; |
| 47 | } |
| 48 | |
| 49 | trigger = zmalloc(sizeof(struct lttng_trigger)); |
| 50 | if (!trigger) { |
| 51 | goto end; |
| 52 | } |
| 53 | |
| 54 | urcu_ref_init(&trigger->ref); |
| 55 | |
| 56 | lttng_condition_get(condition); |
| 57 | trigger->condition = condition; |
| 58 | |
| 59 | lttng_action_get(action); |
| 60 | trigger->action = action; |
| 61 | |
| 62 | end: |
| 63 | return trigger; |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Note: the lack of reference counting 'get' on the condition object is normal. |
| 68 | * This API was exposed as such in 2.11. The client is not expected to call |
| 69 | * lttng_condition_destroy on the returned object. |
| 70 | */ |
| 71 | struct lttng_condition *lttng_trigger_get_condition( |
| 72 | struct lttng_trigger *trigger) |
| 73 | { |
| 74 | return trigger ? trigger->condition : NULL; |
| 75 | } |
| 76 | |
| 77 | LTTNG_HIDDEN |
| 78 | const struct lttng_condition *lttng_trigger_get_const_condition( |
| 79 | const struct lttng_trigger *trigger) |
| 80 | { |
| 81 | return trigger->condition; |
| 82 | } |
| 83 | |
| 84 | |
| 85 | /* |
| 86 | * Note: the lack of reference counting 'get' on the action object is normal. |
| 87 | * This API was exposed as such in 2.11. The client is not expected to call |
| 88 | * lttng_action_destroy on the returned object. |
| 89 | */ |
| 90 | struct lttng_action *lttng_trigger_get_action( |
| 91 | struct lttng_trigger *trigger) |
| 92 | { |
| 93 | return trigger ? trigger->action : NULL; |
| 94 | } |
| 95 | |
| 96 | LTTNG_HIDDEN |
| 97 | const struct lttng_action *lttng_trigger_get_const_action( |
| 98 | const struct lttng_trigger *trigger) |
| 99 | { |
| 100 | return trigger->action; |
| 101 | } |
| 102 | |
| 103 | static void trigger_destroy_ref(struct urcu_ref *ref) |
| 104 | { |
| 105 | struct lttng_trigger *trigger = |
| 106 | container_of(ref, struct lttng_trigger, ref); |
| 107 | struct lttng_action *action = lttng_trigger_get_action(trigger); |
| 108 | struct lttng_condition *condition = |
| 109 | lttng_trigger_get_condition(trigger); |
| 110 | |
| 111 | assert(action); |
| 112 | assert(condition); |
| 113 | |
| 114 | /* Release ownership. */ |
| 115 | lttng_action_put(action); |
| 116 | lttng_condition_put(condition); |
| 117 | |
| 118 | free(trigger); |
| 119 | } |
| 120 | |
| 121 | void lttng_trigger_destroy(struct lttng_trigger *trigger) |
| 122 | { |
| 123 | lttng_trigger_put(trigger); |
| 124 | } |
| 125 | |
| 126 | LTTNG_HIDDEN |
| 127 | ssize_t lttng_trigger_create_from_payload( |
| 128 | struct lttng_payload_view *src_view, |
| 129 | struct lttng_trigger **trigger) |
| 130 | { |
| 131 | ssize_t ret, offset = 0, condition_size, action_size; |
| 132 | struct lttng_condition *condition = NULL; |
| 133 | struct lttng_action *action = NULL; |
| 134 | const struct lttng_trigger_comm *trigger_comm; |
| 135 | struct lttng_credentials creds = { |
| 136 | .uid = LTTNG_OPTIONAL_INIT_UNSET, |
| 137 | .gid = LTTNG_OPTIONAL_INIT_UNSET, |
| 138 | }; |
| 139 | |
| 140 | if (!src_view || !trigger) { |
| 141 | ret = -1; |
| 142 | goto end; |
| 143 | } |
| 144 | |
| 145 | /* lttng_trigger_comm header */ |
| 146 | trigger_comm = (typeof(trigger_comm)) src_view->buffer.data; |
| 147 | |
| 148 | /* Set the trigger's creds. */ |
| 149 | if (trigger_comm->uid > (uint64_t) ((uid_t) -1)) { |
| 150 | /* UID out of range for this platform. */ |
| 151 | ret = -1; |
| 152 | goto end; |
| 153 | } |
| 154 | |
| 155 | LTTNG_OPTIONAL_SET(&creds.uid, trigger_comm->uid); |
| 156 | |
| 157 | offset += sizeof(*trigger_comm); |
| 158 | { |
| 159 | /* struct lttng_condition */ |
| 160 | struct lttng_payload_view condition_view = |
| 161 | lttng_payload_view_from_view( |
| 162 | src_view, offset, -1); |
| 163 | |
| 164 | condition_size = lttng_condition_create_from_payload(&condition_view, |
| 165 | &condition); |
| 166 | } |
| 167 | |
| 168 | if (condition_size < 0) { |
| 169 | ret = condition_size; |
| 170 | goto end; |
| 171 | } |
| 172 | |
| 173 | offset += condition_size; |
| 174 | { |
| 175 | /* struct lttng_action */ |
| 176 | struct lttng_payload_view action_view = |
| 177 | lttng_payload_view_from_view( |
| 178 | src_view, offset, -1); |
| 179 | |
| 180 | action_size = lttng_action_create_from_payload(&action_view, &action); |
| 181 | } |
| 182 | |
| 183 | if (action_size < 0) { |
| 184 | ret = action_size; |
| 185 | goto end; |
| 186 | } |
| 187 | offset += action_size; |
| 188 | |
| 189 | /* Unexpected size of inner-elements; the buffer is corrupted. */ |
| 190 | if ((ssize_t) trigger_comm->length != condition_size + action_size) { |
| 191 | ret = -1; |
| 192 | goto error; |
| 193 | } |
| 194 | |
| 195 | *trigger = lttng_trigger_create(condition, action); |
| 196 | if (!*trigger) { |
| 197 | ret = -1; |
| 198 | goto error; |
| 199 | } |
| 200 | |
| 201 | lttng_trigger_set_credentials(*trigger, &creds); |
| 202 | |
| 203 | /* |
| 204 | * The trigger object owns references to the action and condition |
| 205 | * objects. |
| 206 | */ |
| 207 | lttng_condition_put(condition); |
| 208 | condition = NULL; |
| 209 | |
| 210 | lttng_action_put(action); |
| 211 | action = NULL; |
| 212 | |
| 213 | ret = offset; |
| 214 | |
| 215 | error: |
| 216 | lttng_condition_destroy(condition); |
| 217 | lttng_action_destroy(action); |
| 218 | end: |
| 219 | return ret; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Both elements are stored contiguously, see their "*_comm" structure |
| 224 | * for the detailed format. |
| 225 | */ |
| 226 | LTTNG_HIDDEN |
| 227 | int lttng_trigger_serialize(struct lttng_trigger *trigger, |
| 228 | struct lttng_payload *payload) |
| 229 | { |
| 230 | int ret; |
| 231 | size_t header_offset, size_before_payload; |
| 232 | struct lttng_trigger_comm trigger_comm = {}; |
| 233 | struct lttng_trigger_comm *header; |
| 234 | const struct lttng_credentials *creds = NULL; |
| 235 | |
| 236 | creds = lttng_trigger_get_credentials(trigger); |
| 237 | assert(creds); |
| 238 | |
| 239 | trigger_comm.uid = LTTNG_OPTIONAL_GET(creds->uid); |
| 240 | |
| 241 | header_offset = payload->buffer.size; |
| 242 | ret = lttng_dynamic_buffer_append(&payload->buffer, &trigger_comm, |
| 243 | sizeof(trigger_comm)); |
| 244 | if (ret) { |
| 245 | goto end; |
| 246 | } |
| 247 | |
| 248 | size_before_payload = payload->buffer.size; |
| 249 | ret = lttng_condition_serialize(trigger->condition, payload); |
| 250 | if (ret) { |
| 251 | goto end; |
| 252 | } |
| 253 | |
| 254 | ret = lttng_action_serialize(trigger->action, payload); |
| 255 | if (ret) { |
| 256 | goto end; |
| 257 | } |
| 258 | |
| 259 | /* Update payload size. */ |
| 260 | header = (typeof(header)) (payload->buffer.data + header_offset); |
| 261 | header->length = payload->buffer.size - size_before_payload; |
| 262 | end: |
| 263 | return ret; |
| 264 | } |
| 265 | |
| 266 | LTTNG_HIDDEN |
| 267 | bool lttng_trigger_is_equal( |
| 268 | const struct lttng_trigger *a, const struct lttng_trigger *b) |
| 269 | { |
| 270 | /* |
| 271 | * Name is not taken into account since it is cosmetic only. |
| 272 | */ |
| 273 | if (!lttng_condition_is_equal(a->condition, b->condition)) { |
| 274 | return false; |
| 275 | } |
| 276 | |
| 277 | if (!lttng_action_is_equal(a->action, b->action)) { |
| 278 | return false; |
| 279 | } |
| 280 | |
| 281 | if (!lttng_credentials_is_equal(lttng_trigger_get_credentials(a), |
| 282 | lttng_trigger_get_credentials(b))) { |
| 283 | return false; |
| 284 | } |
| 285 | |
| 286 | return true; |
| 287 | } |
| 288 | |
| 289 | LTTNG_HIDDEN |
| 290 | void lttng_trigger_get(struct lttng_trigger *trigger) |
| 291 | { |
| 292 | urcu_ref_get(&trigger->ref); |
| 293 | } |
| 294 | |
| 295 | LTTNG_HIDDEN |
| 296 | void lttng_trigger_put(struct lttng_trigger *trigger) |
| 297 | { |
| 298 | if (!trigger) { |
| 299 | return; |
| 300 | } |
| 301 | |
| 302 | urcu_ref_put(&trigger->ref , trigger_destroy_ref); |
| 303 | } |
| 304 | |
| 305 | LTTNG_HIDDEN |
| 306 | const struct lttng_credentials *lttng_trigger_get_credentials( |
| 307 | const struct lttng_trigger *trigger) |
| 308 | { |
| 309 | return &trigger->creds; |
| 310 | } |
| 311 | |
| 312 | LTTNG_HIDDEN |
| 313 | void lttng_trigger_set_credentials(struct lttng_trigger *trigger, |
| 314 | const struct lttng_credentials *creds) |
| 315 | { |
| 316 | assert(creds); |
| 317 | trigger->creds = *creds; |
| 318 | } |
| 319 | |
| 320 | enum lttng_trigger_status lttng_trigger_set_owner_uid( |
| 321 | struct lttng_trigger *trigger, uid_t uid) |
| 322 | { |
| 323 | enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK; |
| 324 | const struct lttng_credentials creds = { |
| 325 | .uid = LTTNG_OPTIONAL_INIT_VALUE(uid), |
| 326 | .gid = LTTNG_OPTIONAL_INIT_UNSET, |
| 327 | }; |
| 328 | |
| 329 | if (!trigger) { |
| 330 | ret = LTTNG_TRIGGER_STATUS_INVALID; |
| 331 | goto end; |
| 332 | } |
| 333 | |
| 334 | /* Client-side validation only to report a clearer error. */ |
| 335 | if (geteuid() != 0) { |
| 336 | ret = LTTNG_TRIGGER_STATUS_PERMISSION_DENIED; |
| 337 | goto end; |
| 338 | } |
| 339 | |
| 340 | lttng_trigger_set_credentials(trigger, &creds); |
| 341 | |
| 342 | end: |
| 343 | return ret; |
| 344 | } |
| 345 | |
| 346 | enum lttng_trigger_status lttng_trigger_get_owner_uid( |
| 347 | const struct lttng_trigger *trigger, uid_t *uid) |
| 348 | { |
| 349 | enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK; |
| 350 | const struct lttng_credentials *creds = NULL; |
| 351 | |
| 352 | if (!trigger || !uid ) { |
| 353 | ret = LTTNG_TRIGGER_STATUS_INVALID; |
| 354 | goto end; |
| 355 | } |
| 356 | |
| 357 | if (!trigger->creds.uid.is_set ) { |
| 358 | ret = LTTNG_TRIGGER_STATUS_UNSET; |
| 359 | goto end; |
| 360 | } |
| 361 | |
| 362 | creds = lttng_trigger_get_credentials(trigger); |
| 363 | *uid = lttng_credentials_get_uid(creds); |
| 364 | |
| 365 | end: |
| 366 | return ret; |
| 367 | } |