| 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 | #include <inttypes.h> |
| 18 | |
| 19 | LTTNG_HIDDEN |
| 20 | bool lttng_trigger_validate(struct lttng_trigger *trigger) |
| 21 | { |
| 22 | bool valid; |
| 23 | |
| 24 | if (!trigger) { |
| 25 | valid = false; |
| 26 | goto end; |
| 27 | } |
| 28 | |
| 29 | if (!trigger->creds.uid.is_set) { |
| 30 | valid = false; |
| 31 | goto end; |
| 32 | } |
| 33 | |
| 34 | valid = lttng_condition_validate(trigger->condition) && |
| 35 | lttng_action_validate(trigger->action); |
| 36 | end: |
| 37 | return valid; |
| 38 | } |
| 39 | |
| 40 | struct lttng_trigger *lttng_trigger_create( |
| 41 | struct lttng_condition *condition, |
| 42 | struct lttng_action *action) |
| 43 | { |
| 44 | struct lttng_trigger *trigger = NULL; |
| 45 | |
| 46 | if (!condition || !action) { |
| 47 | goto end; |
| 48 | } |
| 49 | |
| 50 | trigger = zmalloc(sizeof(struct lttng_trigger)); |
| 51 | if (!trigger) { |
| 52 | goto end; |
| 53 | } |
| 54 | |
| 55 | urcu_ref_init(&trigger->ref); |
| 56 | |
| 57 | lttng_condition_get(condition); |
| 58 | trigger->condition = condition; |
| 59 | |
| 60 | lttng_action_get(action); |
| 61 | trigger->action = action; |
| 62 | |
| 63 | end: |
| 64 | return trigger; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * Note: the lack of reference counting 'get' on the condition object is normal. |
| 69 | * This API was exposed as such in 2.11. The client is not expected to call |
| 70 | * lttng_condition_destroy on the returned object. |
| 71 | */ |
| 72 | struct lttng_condition *lttng_trigger_get_condition( |
| 73 | struct lttng_trigger *trigger) |
| 74 | { |
| 75 | return trigger ? trigger->condition : NULL; |
| 76 | } |
| 77 | |
| 78 | LTTNG_HIDDEN |
| 79 | const struct lttng_condition *lttng_trigger_get_const_condition( |
| 80 | const struct lttng_trigger *trigger) |
| 81 | { |
| 82 | return trigger->condition; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | /* |
| 87 | * Note: the lack of reference counting 'get' on the action object is normal. |
| 88 | * This API was exposed as such in 2.11. The client is not expected to call |
| 89 | * lttng_action_destroy on the returned object. |
| 90 | */ |
| 91 | struct lttng_action *lttng_trigger_get_action( |
| 92 | struct lttng_trigger *trigger) |
| 93 | { |
| 94 | return trigger ? trigger->action : NULL; |
| 95 | } |
| 96 | |
| 97 | LTTNG_HIDDEN |
| 98 | const struct lttng_action *lttng_trigger_get_const_action( |
| 99 | const struct lttng_trigger *trigger) |
| 100 | { |
| 101 | return trigger->action; |
| 102 | } |
| 103 | |
| 104 | static void trigger_destroy_ref(struct urcu_ref *ref) |
| 105 | { |
| 106 | struct lttng_trigger *trigger = |
| 107 | container_of(ref, struct lttng_trigger, ref); |
| 108 | struct lttng_action *action = lttng_trigger_get_action(trigger); |
| 109 | struct lttng_condition *condition = |
| 110 | lttng_trigger_get_condition(trigger); |
| 111 | |
| 112 | assert(action); |
| 113 | assert(condition); |
| 114 | |
| 115 | /* Release ownership. */ |
| 116 | lttng_action_put(action); |
| 117 | lttng_condition_put(condition); |
| 118 | |
| 119 | free(trigger->name); |
| 120 | free(trigger); |
| 121 | } |
| 122 | |
| 123 | void lttng_trigger_destroy(struct lttng_trigger *trigger) |
| 124 | { |
| 125 | lttng_trigger_put(trigger); |
| 126 | } |
| 127 | |
| 128 | LTTNG_HIDDEN |
| 129 | ssize_t lttng_trigger_create_from_payload( |
| 130 | struct lttng_payload_view *src_view, |
| 131 | struct lttng_trigger **trigger) |
| 132 | { |
| 133 | ssize_t ret, offset = 0, condition_size, action_size, name_size = 0; |
| 134 | struct lttng_condition *condition = NULL; |
| 135 | struct lttng_action *action = NULL; |
| 136 | const struct lttng_trigger_comm *trigger_comm; |
| 137 | const char *name = NULL; |
| 138 | struct lttng_credentials creds = { |
| 139 | .uid = LTTNG_OPTIONAL_INIT_UNSET, |
| 140 | .gid = LTTNG_OPTIONAL_INIT_UNSET, |
| 141 | }; |
| 142 | |
| 143 | if (!src_view || !trigger) { |
| 144 | ret = -1; |
| 145 | goto end; |
| 146 | } |
| 147 | |
| 148 | /* lttng_trigger_comm header */ |
| 149 | trigger_comm = (typeof(trigger_comm)) src_view->buffer.data; |
| 150 | |
| 151 | /* Set the trigger's creds. */ |
| 152 | if (trigger_comm->uid > (uint64_t) ((uid_t) -1)) { |
| 153 | /* UID out of range for this platform. */ |
| 154 | ret = -1; |
| 155 | goto end; |
| 156 | } |
| 157 | |
| 158 | LTTNG_OPTIONAL_SET(&creds.uid, trigger_comm->uid); |
| 159 | |
| 160 | offset += sizeof(*trigger_comm); |
| 161 | |
| 162 | if (trigger_comm->name_length != 0) { |
| 163 | /* Name. */ |
| 164 | const struct lttng_payload_view name_view = |
| 165 | lttng_payload_view_from_view( |
| 166 | src_view, offset, trigger_comm->name_length); |
| 167 | |
| 168 | name = name_view.buffer.data; |
| 169 | if (!lttng_buffer_view_contains_string(&name_view.buffer, name, |
| 170 | trigger_comm->name_length)) { |
| 171 | ret = -1; |
| 172 | goto end; |
| 173 | } |
| 174 | |
| 175 | offset += trigger_comm->name_length; |
| 176 | name_size = trigger_comm->name_length; |
| 177 | } |
| 178 | |
| 179 | { |
| 180 | /* struct lttng_condition */ |
| 181 | struct lttng_payload_view condition_view = |
| 182 | lttng_payload_view_from_view( |
| 183 | src_view, offset, -1); |
| 184 | |
| 185 | condition_size = lttng_condition_create_from_payload(&condition_view, |
| 186 | &condition); |
| 187 | } |
| 188 | |
| 189 | if (condition_size < 0) { |
| 190 | ret = condition_size; |
| 191 | goto end; |
| 192 | } |
| 193 | |
| 194 | offset += condition_size; |
| 195 | { |
| 196 | /* struct lttng_action */ |
| 197 | struct lttng_payload_view action_view = |
| 198 | lttng_payload_view_from_view( |
| 199 | src_view, offset, -1); |
| 200 | |
| 201 | action_size = lttng_action_create_from_payload(&action_view, &action); |
| 202 | } |
| 203 | |
| 204 | if (action_size < 0) { |
| 205 | ret = action_size; |
| 206 | goto end; |
| 207 | } |
| 208 | offset += action_size; |
| 209 | |
| 210 | /* Unexpected size of inner-elements; the buffer is corrupted. */ |
| 211 | if ((ssize_t) trigger_comm->length != condition_size + action_size + name_size) { |
| 212 | ret = -1; |
| 213 | goto error; |
| 214 | } |
| 215 | |
| 216 | *trigger = lttng_trigger_create(condition, action); |
| 217 | if (!*trigger) { |
| 218 | ret = -1; |
| 219 | goto error; |
| 220 | } |
| 221 | |
| 222 | lttng_trigger_set_credentials(*trigger, &creds); |
| 223 | |
| 224 | /* |
| 225 | * The trigger object owns references to the action and condition |
| 226 | * objects. |
| 227 | */ |
| 228 | lttng_condition_put(condition); |
| 229 | condition = NULL; |
| 230 | |
| 231 | lttng_action_put(action); |
| 232 | action = NULL; |
| 233 | |
| 234 | if (name) { |
| 235 | const enum lttng_trigger_status status = |
| 236 | lttng_trigger_set_name(*trigger, name); |
| 237 | |
| 238 | if (status != LTTNG_TRIGGER_STATUS_OK) { |
| 239 | ret = -1; |
| 240 | goto end; |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | ret = offset; |
| 245 | |
| 246 | error: |
| 247 | lttng_condition_destroy(condition); |
| 248 | lttng_action_destroy(action); |
| 249 | end: |
| 250 | return ret; |
| 251 | } |
| 252 | |
| 253 | /* |
| 254 | * Both elements are stored contiguously, see their "*_comm" structure |
| 255 | * for the detailed format. |
| 256 | */ |
| 257 | LTTNG_HIDDEN |
| 258 | int lttng_trigger_serialize(struct lttng_trigger *trigger, |
| 259 | struct lttng_payload *payload) |
| 260 | { |
| 261 | int ret; |
| 262 | size_t header_offset, size_before_payload, size_name; |
| 263 | struct lttng_trigger_comm trigger_comm = {}; |
| 264 | struct lttng_trigger_comm *header; |
| 265 | const struct lttng_credentials *creds = NULL; |
| 266 | |
| 267 | creds = lttng_trigger_get_credentials(trigger); |
| 268 | assert(creds); |
| 269 | |
| 270 | trigger_comm.uid = LTTNG_OPTIONAL_GET(creds->uid); |
| 271 | |
| 272 | if (trigger->name != NULL) { |
| 273 | size_name = strlen(trigger->name) + 1; |
| 274 | } else { |
| 275 | size_name = 0; |
| 276 | } |
| 277 | |
| 278 | trigger_comm.name_length = size_name; |
| 279 | |
| 280 | header_offset = payload->buffer.size; |
| 281 | ret = lttng_dynamic_buffer_append(&payload->buffer, &trigger_comm, |
| 282 | sizeof(trigger_comm)); |
| 283 | if (ret) { |
| 284 | goto end; |
| 285 | } |
| 286 | |
| 287 | size_before_payload = payload->buffer.size; |
| 288 | |
| 289 | /* Trigger name. */ |
| 290 | ret = lttng_dynamic_buffer_append( |
| 291 | &payload->buffer, trigger->name, size_name); |
| 292 | if (ret) { |
| 293 | goto end; |
| 294 | } |
| 295 | |
| 296 | ret = lttng_condition_serialize(trigger->condition, payload); |
| 297 | if (ret) { |
| 298 | goto end; |
| 299 | } |
| 300 | |
| 301 | ret = lttng_action_serialize(trigger->action, payload); |
| 302 | if (ret) { |
| 303 | goto end; |
| 304 | } |
| 305 | |
| 306 | /* Update payload size. */ |
| 307 | header = (typeof(header)) (payload->buffer.data + header_offset); |
| 308 | header->length = payload->buffer.size - size_before_payload; |
| 309 | end: |
| 310 | return ret; |
| 311 | } |
| 312 | |
| 313 | LTTNG_HIDDEN |
| 314 | bool lttng_trigger_is_equal( |
| 315 | const struct lttng_trigger *a, const struct lttng_trigger *b) |
| 316 | { |
| 317 | /* |
| 318 | * Name is not taken into account since it is cosmetic only. |
| 319 | */ |
| 320 | if (!lttng_condition_is_equal(a->condition, b->condition)) { |
| 321 | return false; |
| 322 | } |
| 323 | |
| 324 | if (!lttng_action_is_equal(a->action, b->action)) { |
| 325 | return false; |
| 326 | } |
| 327 | |
| 328 | if (!lttng_credentials_is_equal(lttng_trigger_get_credentials(a), |
| 329 | lttng_trigger_get_credentials(b))) { |
| 330 | return false; |
| 331 | } |
| 332 | |
| 333 | return true; |
| 334 | } |
| 335 | |
| 336 | enum lttng_trigger_status lttng_trigger_set_name(struct lttng_trigger *trigger, |
| 337 | const char* name) |
| 338 | { |
| 339 | char *name_copy = NULL; |
| 340 | enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK; |
| 341 | |
| 342 | if (!trigger || !name || |
| 343 | strlen(name) == 0) { |
| 344 | status = LTTNG_TRIGGER_STATUS_INVALID; |
| 345 | goto end; |
| 346 | } |
| 347 | |
| 348 | name_copy = strdup(name); |
| 349 | if (!name_copy) { |
| 350 | status = LTTNG_TRIGGER_STATUS_ERROR; |
| 351 | goto end; |
| 352 | } |
| 353 | |
| 354 | free(trigger->name); |
| 355 | |
| 356 | trigger->name = name_copy; |
| 357 | name_copy = NULL; |
| 358 | end: |
| 359 | return status; |
| 360 | } |
| 361 | |
| 362 | enum lttng_trigger_status lttng_trigger_get_name( |
| 363 | const struct lttng_trigger *trigger, const char **name) |
| 364 | { |
| 365 | enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK; |
| 366 | |
| 367 | if (!trigger || !name) { |
| 368 | status = LTTNG_TRIGGER_STATUS_INVALID; |
| 369 | goto end; |
| 370 | } |
| 371 | |
| 372 | if (!trigger->name) { |
| 373 | status = LTTNG_TRIGGER_STATUS_UNSET; |
| 374 | } |
| 375 | |
| 376 | *name = trigger->name; |
| 377 | end: |
| 378 | return status; |
| 379 | } |
| 380 | |
| 381 | LTTNG_HIDDEN |
| 382 | int lttng_trigger_assign_name(struct lttng_trigger *dst, |
| 383 | const struct lttng_trigger *src) |
| 384 | { |
| 385 | int ret = 0; |
| 386 | enum lttng_trigger_status status; |
| 387 | |
| 388 | status = lttng_trigger_set_name(dst, src->name); |
| 389 | if (status != LTTNG_TRIGGER_STATUS_OK) { |
| 390 | ret = -1; |
| 391 | ERR("Failed to set name for trigger"); |
| 392 | goto end; |
| 393 | } |
| 394 | end: |
| 395 | return ret; |
| 396 | } |
| 397 | |
| 398 | LTTNG_HIDDEN |
| 399 | void lttng_trigger_set_tracer_token(struct lttng_trigger *trigger, |
| 400 | uint64_t token) |
| 401 | { |
| 402 | assert(trigger); |
| 403 | LTTNG_OPTIONAL_SET(&trigger->tracer_token, token); |
| 404 | } |
| 405 | |
| 406 | LTTNG_HIDDEN |
| 407 | uint64_t lttng_trigger_get_tracer_token(const struct lttng_trigger *trigger) |
| 408 | { |
| 409 | assert(trigger); |
| 410 | |
| 411 | return LTTNG_OPTIONAL_GET(trigger->tracer_token); |
| 412 | } |
| 413 | |
| 414 | LTTNG_HIDDEN |
| 415 | int lttng_trigger_generate_name(struct lttng_trigger *trigger, |
| 416 | uint64_t unique_id) |
| 417 | { |
| 418 | int ret = 0; |
| 419 | char *generated_name = NULL; |
| 420 | |
| 421 | ret = asprintf(&generated_name, "T%" PRIu64 "", unique_id); |
| 422 | if (ret < 0) { |
| 423 | ERR("Failed to generate trigger name"); |
| 424 | ret = -1; |
| 425 | goto end; |
| 426 | } |
| 427 | |
| 428 | ret = 0; |
| 429 | free(trigger->name); |
| 430 | trigger->name = generated_name; |
| 431 | end: |
| 432 | return ret; |
| 433 | } |
| 434 | |
| 435 | LTTNG_HIDDEN |
| 436 | void lttng_trigger_get(struct lttng_trigger *trigger) |
| 437 | { |
| 438 | urcu_ref_get(&trigger->ref); |
| 439 | } |
| 440 | |
| 441 | LTTNG_HIDDEN |
| 442 | void lttng_trigger_put(struct lttng_trigger *trigger) |
| 443 | { |
| 444 | if (!trigger) { |
| 445 | return; |
| 446 | } |
| 447 | |
| 448 | urcu_ref_put(&trigger->ref , trigger_destroy_ref); |
| 449 | } |
| 450 | |
| 451 | LTTNG_HIDDEN |
| 452 | const struct lttng_credentials *lttng_trigger_get_credentials( |
| 453 | const struct lttng_trigger *trigger) |
| 454 | { |
| 455 | return &trigger->creds; |
| 456 | } |
| 457 | |
| 458 | LTTNG_HIDDEN |
| 459 | void lttng_trigger_set_credentials(struct lttng_trigger *trigger, |
| 460 | const struct lttng_credentials *creds) |
| 461 | { |
| 462 | assert(creds); |
| 463 | trigger->creds = *creds; |
| 464 | } |
| 465 | |
| 466 | enum lttng_trigger_status lttng_trigger_set_owner_uid( |
| 467 | struct lttng_trigger *trigger, uid_t uid) |
| 468 | { |
| 469 | enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK; |
| 470 | const struct lttng_credentials creds = { |
| 471 | .uid = LTTNG_OPTIONAL_INIT_VALUE(uid), |
| 472 | .gid = LTTNG_OPTIONAL_INIT_UNSET, |
| 473 | }; |
| 474 | |
| 475 | if (!trigger) { |
| 476 | ret = LTTNG_TRIGGER_STATUS_INVALID; |
| 477 | goto end; |
| 478 | } |
| 479 | |
| 480 | /* Client-side validation only to report a clearer error. */ |
| 481 | if (geteuid() != 0) { |
| 482 | ret = LTTNG_TRIGGER_STATUS_PERMISSION_DENIED; |
| 483 | goto end; |
| 484 | } |
| 485 | |
| 486 | lttng_trigger_set_credentials(trigger, &creds); |
| 487 | |
| 488 | end: |
| 489 | return ret; |
| 490 | } |
| 491 | |
| 492 | enum lttng_trigger_status lttng_trigger_get_owner_uid( |
| 493 | const struct lttng_trigger *trigger, uid_t *uid) |
| 494 | { |
| 495 | enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK; |
| 496 | const struct lttng_credentials *creds = NULL; |
| 497 | |
| 498 | if (!trigger || !uid ) { |
| 499 | ret = LTTNG_TRIGGER_STATUS_INVALID; |
| 500 | goto end; |
| 501 | } |
| 502 | |
| 503 | if (!trigger->creds.uid.is_set ) { |
| 504 | ret = LTTNG_TRIGGER_STATUS_UNSET; |
| 505 | goto end; |
| 506 | } |
| 507 | |
| 508 | creds = lttng_trigger_get_credentials(trigger); |
| 509 | *uid = lttng_credentials_get_uid(creds); |
| 510 | |
| 511 | end: |
| 512 | return ret; |
| 513 | } |