| 1 | /* |
| 2 | * Copyright (C) 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include <grp.h> |
| 10 | #include <pwd.h> |
| 11 | #include <sys/types.h> |
| 12 | #include <unistd.h> |
| 13 | |
| 14 | #include "tracker.h" |
| 15 | #include <common/defaults.h> |
| 16 | #include <common/error.h> |
| 17 | #include <common/hashtable/hashtable.h> |
| 18 | #include <common/hashtable/utils.h> |
| 19 | #include <lttng/lttng-error.h> |
| 20 | #include <lttng/tracker-internal.h> |
| 21 | |
| 22 | #define FALLBACK_USER_BUFLEN 16384 |
| 23 | #define FALLBACK_GROUP_BUFLEN 16384 |
| 24 | |
| 25 | struct lttng_tracker_list *lttng_tracker_list_create(void) |
| 26 | { |
| 27 | struct lttng_tracker_list *t; |
| 28 | |
| 29 | t = zmalloc(sizeof(*t)); |
| 30 | if (!t) { |
| 31 | return NULL; |
| 32 | } |
| 33 | t->ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 34 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 35 | if (!t->ht) { |
| 36 | goto error; |
| 37 | } |
| 38 | CDS_INIT_LIST_HEAD(&t->list_head); |
| 39 | t->state = LTTNG_TRACK_ALL; |
| 40 | return t; |
| 41 | |
| 42 | error: |
| 43 | free(t); |
| 44 | return NULL; |
| 45 | } |
| 46 | |
| 47 | static int match_tracker_key(struct cds_lfht_node *node, const void *key) |
| 48 | { |
| 49 | const struct lttng_tracker_id *tracker_key = key; |
| 50 | struct lttng_tracker_list_node *tracker_node; |
| 51 | |
| 52 | tracker_node = caa_container_of( |
| 53 | node, struct lttng_tracker_list_node, ht_node); |
| 54 | |
| 55 | return lttng_tracker_id_is_equal(tracker_node->id, tracker_key); |
| 56 | } |
| 57 | |
| 58 | static unsigned long hash_tracker_key( |
| 59 | const struct lttng_tracker_id *tracker_key) |
| 60 | { |
| 61 | unsigned long key_hash = 0; |
| 62 | int value; |
| 63 | const char *string; |
| 64 | enum lttng_tracker_id_type type; |
| 65 | |
| 66 | /* We do not care for invalid state during hash computation */ |
| 67 | type = lttng_tracker_id_get_type(tracker_key); |
| 68 | (void) lttng_tracker_id_get_value(tracker_key, &value); |
| 69 | (void) lttng_tracker_id_get_string(tracker_key, &string); |
| 70 | |
| 71 | switch (type) { |
| 72 | case LTTNG_ID_ALL: |
| 73 | break; |
| 74 | case LTTNG_ID_VALUE: |
| 75 | key_hash ^= hash_key_ulong( |
| 76 | (void *) (unsigned long) value, lttng_ht_seed); |
| 77 | break; |
| 78 | case LTTNG_ID_STRING: |
| 79 | key_hash ^= hash_key_str(string, lttng_ht_seed); |
| 80 | break; |
| 81 | case LTTNG_ID_UNKNOWN: |
| 82 | break; |
| 83 | } |
| 84 | key_hash ^= hash_key_ulong( |
| 85 | (void *) (unsigned long) type, lttng_ht_seed); |
| 86 | return key_hash; |
| 87 | } |
| 88 | |
| 89 | static struct lttng_tracker_id **lttng_tracker_list_lookup( |
| 90 | const struct lttng_tracker_list *tracker_list, |
| 91 | const struct lttng_tracker_id *key) |
| 92 | { |
| 93 | struct lttng_tracker_list_node *list_node; |
| 94 | struct cds_lfht_iter iter; |
| 95 | struct cds_lfht_node *node; |
| 96 | |
| 97 | cds_lfht_lookup(tracker_list->ht, hash_tracker_key(key), |
| 98 | match_tracker_key, key, &iter); |
| 99 | node = cds_lfht_iter_get_node(&iter); |
| 100 | if (!node) { |
| 101 | return NULL; |
| 102 | } |
| 103 | list_node = caa_container_of( |
| 104 | node, struct lttng_tracker_list_node, ht_node); |
| 105 | return &list_node->id; |
| 106 | } |
| 107 | |
| 108 | static void destroy_list_node_rcu(struct rcu_head *head) |
| 109 | { |
| 110 | struct lttng_tracker_list_node *n = caa_container_of( |
| 111 | head, struct lttng_tracker_list_node, rcu_head); |
| 112 | |
| 113 | lttng_tracker_id_destroy(n->id); |
| 114 | free(n); |
| 115 | } |
| 116 | |
| 117 | static void _lttng_tracker_list_remove(struct lttng_tracker_list *tracker_list, |
| 118 | struct lttng_tracker_list_node *n) |
| 119 | { |
| 120 | cds_list_del(&n->list_node); |
| 121 | |
| 122 | rcu_read_lock(); |
| 123 | cds_lfht_del(tracker_list->ht, &n->ht_node); |
| 124 | rcu_read_unlock(); |
| 125 | |
| 126 | call_rcu(&n->rcu_head, destroy_list_node_rcu); |
| 127 | } |
| 128 | |
| 129 | static void lttng_tracker_list_reset(struct lttng_tracker_list *tracker_list) |
| 130 | { |
| 131 | struct lttng_tracker_list_node *n, *t; |
| 132 | |
| 133 | cds_list_for_each_entry_safe ( |
| 134 | n, t, &tracker_list->list_head, list_node) { |
| 135 | _lttng_tracker_list_remove(tracker_list, n); |
| 136 | } |
| 137 | tracker_list->state = LTTNG_TRACK_ALL; |
| 138 | } |
| 139 | |
| 140 | /* Protected by session mutex held by caller. */ |
| 141 | int lttng_tracker_list_add(struct lttng_tracker_list *tracker_list, |
| 142 | const struct lttng_tracker_id *_id) |
| 143 | { |
| 144 | struct lttng_tracker_id **id; |
| 145 | struct lttng_tracker_list_node *n = NULL; |
| 146 | int ret; |
| 147 | |
| 148 | if (lttng_tracker_id_get_type(_id) == LTTNG_ID_ALL) { |
| 149 | /* Track all, so remove each individual item. */ |
| 150 | lttng_tracker_list_reset(tracker_list); |
| 151 | ret = LTTNG_OK; |
| 152 | goto error; |
| 153 | } |
| 154 | rcu_read_lock(); |
| 155 | id = lttng_tracker_list_lookup(tracker_list, _id); |
| 156 | /* |
| 157 | * It is okay to release the RCU read lock here since id is only checked |
| 158 | * for != NULL and not dereferenced. |
| 159 | */ |
| 160 | rcu_read_unlock(); |
| 161 | if (id) { |
| 162 | ret = LTTNG_ERR_ID_TRACKED; |
| 163 | goto error; |
| 164 | } |
| 165 | n = zmalloc(sizeof(*n)); |
| 166 | if (!n) { |
| 167 | ret = LTTNG_ERR_NOMEM; |
| 168 | goto error; |
| 169 | } |
| 170 | |
| 171 | n->id = lttng_tracker_id_duplicate(_id); |
| 172 | if (!n->id) { |
| 173 | ret = LTTNG_ERR_NOMEM; |
| 174 | goto error; |
| 175 | } |
| 176 | |
| 177 | cds_list_add_tail(&n->list_node, &tracker_list->list_head); |
| 178 | tracker_list->state = LTTNG_TRACK_LIST; |
| 179 | |
| 180 | rcu_read_lock(); |
| 181 | cds_lfht_add(tracker_list->ht, hash_tracker_key(n->id), &n->ht_node); |
| 182 | rcu_read_unlock(); |
| 183 | |
| 184 | return LTTNG_OK; |
| 185 | |
| 186 | error: |
| 187 | free(n); |
| 188 | return ret; |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Lookup and remove. |
| 193 | * Protected by session mutex held by caller. |
| 194 | */ |
| 195 | int lttng_tracker_list_remove(struct lttng_tracker_list *tracker_list, |
| 196 | const struct lttng_tracker_id *_id) |
| 197 | { |
| 198 | enum lttng_error_code ret = LTTNG_OK; |
| 199 | struct lttng_tracker_id **id; |
| 200 | struct lttng_tracker_list_node *n; |
| 201 | |
| 202 | if (lttng_tracker_id_get_type(_id) == LTTNG_ID_ALL) { |
| 203 | /* Untrack all. */ |
| 204 | lttng_tracker_list_reset(tracker_list); |
| 205 | /* Set state to "track none". */ |
| 206 | tracker_list->state = LTTNG_TRACK_NONE; |
| 207 | goto end; |
| 208 | } |
| 209 | |
| 210 | rcu_read_lock(); |
| 211 | id = lttng_tracker_list_lookup(tracker_list, _id); |
| 212 | if (!id) { |
| 213 | ret = LTTNG_ERR_ID_NOT_TRACKED; |
| 214 | goto rcu_unlock; |
| 215 | } |
| 216 | |
| 217 | n = caa_container_of(id, struct lttng_tracker_list_node, id); |
| 218 | _lttng_tracker_list_remove(tracker_list, n); |
| 219 | |
| 220 | rcu_unlock: |
| 221 | rcu_read_unlock(); |
| 222 | end: |
| 223 | return ret; |
| 224 | } |
| 225 | |
| 226 | void lttng_tracker_list_destroy(struct lttng_tracker_list *tracker_list) |
| 227 | { |
| 228 | int ret; |
| 229 | |
| 230 | if (!tracker_list) { |
| 231 | return; |
| 232 | } |
| 233 | lttng_tracker_list_reset(tracker_list); |
| 234 | ret = cds_lfht_destroy(tracker_list->ht, NULL); |
| 235 | assert(!ret); |
| 236 | free(tracker_list); |
| 237 | } |
| 238 | |
| 239 | static int lttng_lookup_user(const char *username, int *result) |
| 240 | { |
| 241 | struct passwd p, *pres; |
| 242 | int ret, retval = LTTNG_OK; |
| 243 | char *buf = NULL; |
| 244 | ssize_t buflen; |
| 245 | |
| 246 | buflen = sysconf(_SC_GETPW_R_SIZE_MAX); |
| 247 | if (buflen < 0) { |
| 248 | buflen = FALLBACK_USER_BUFLEN; |
| 249 | } |
| 250 | buf = zmalloc(buflen); |
| 251 | if (!buf) { |
| 252 | retval = LTTNG_ERR_NOMEM; |
| 253 | goto end; |
| 254 | } |
| 255 | for (;;) { |
| 256 | ret = getpwnam_r(username, &p, buf, buflen, &pres); |
| 257 | switch (ret) { |
| 258 | case EINTR: |
| 259 | continue; |
| 260 | case ERANGE: |
| 261 | buflen *= 2; |
| 262 | free(buf); |
| 263 | buf = zmalloc(buflen); |
| 264 | if (!buf) { |
| 265 | retval = LTTNG_ERR_NOMEM; |
| 266 | goto end; |
| 267 | } |
| 268 | continue; |
| 269 | default: |
| 270 | goto end_loop; |
| 271 | } |
| 272 | } |
| 273 | end_loop: |
| 274 | |
| 275 | switch (ret) { |
| 276 | case 0: |
| 277 | if (pres == NULL) { |
| 278 | retval = LTTNG_ERR_USER_NOT_FOUND; |
| 279 | } else { |
| 280 | *result = (int) p.pw_uid; |
| 281 | DBG("Lookup of tracker UID/VUID: name '%s' maps to id %d.", |
| 282 | username, *result); |
| 283 | retval = LTTNG_OK; |
| 284 | } |
| 285 | break; |
| 286 | case ENOENT: |
| 287 | case ESRCH: |
| 288 | case EBADF: |
| 289 | case EPERM: |
| 290 | retval = LTTNG_ERR_USER_NOT_FOUND; |
| 291 | break; |
| 292 | default: |
| 293 | retval = LTTNG_ERR_NOMEM; |
| 294 | } |
| 295 | end: |
| 296 | free(buf); |
| 297 | return retval; |
| 298 | } |
| 299 | |
| 300 | static int lttng_lookup_group(const char *groupname, int *result) |
| 301 | { |
| 302 | struct group g, *gres; |
| 303 | int ret, retval = LTTNG_OK; |
| 304 | char *buf = NULL; |
| 305 | ssize_t buflen; |
| 306 | |
| 307 | buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
| 308 | if (buflen < 0) { |
| 309 | buflen = FALLBACK_GROUP_BUFLEN; |
| 310 | } |
| 311 | buf = zmalloc(buflen); |
| 312 | if (!buf) { |
| 313 | retval = LTTNG_ERR_NOMEM; |
| 314 | goto end; |
| 315 | } |
| 316 | for (;;) { |
| 317 | ret = getgrnam_r(groupname, &g, buf, buflen, &gres); |
| 318 | switch (ret) { |
| 319 | case EINTR: |
| 320 | continue; |
| 321 | case ERANGE: |
| 322 | buflen *= 2; |
| 323 | free(buf); |
| 324 | buf = zmalloc(buflen); |
| 325 | if (!buf) { |
| 326 | retval = LTTNG_ERR_NOMEM; |
| 327 | goto end; |
| 328 | } |
| 329 | continue; |
| 330 | default: |
| 331 | goto end_loop; |
| 332 | } |
| 333 | } |
| 334 | end_loop: |
| 335 | |
| 336 | switch (ret) { |
| 337 | case 0: |
| 338 | if (gres == NULL) { |
| 339 | retval = LTTNG_ERR_GROUP_NOT_FOUND; |
| 340 | } else { |
| 341 | *result = (int) g.gr_gid; |
| 342 | DBG("Lookup of tracker GID/GUID: name '%s' maps to id %d.", |
| 343 | groupname, *result); |
| 344 | retval = LTTNG_OK; |
| 345 | } |
| 346 | break; |
| 347 | case ENOENT: |
| 348 | case ESRCH: |
| 349 | case EBADF: |
| 350 | case EPERM: |
| 351 | retval = LTTNG_ERR_GROUP_NOT_FOUND; |
| 352 | break; |
| 353 | default: |
| 354 | retval = LTTNG_ERR_NOMEM; |
| 355 | } |
| 356 | end: |
| 357 | free(buf); |
| 358 | return retval; |
| 359 | } |
| 360 | |
| 361 | int lttng_tracker_id_lookup_string(enum lttng_tracker_type tracker_type, |
| 362 | const struct lttng_tracker_id *id, |
| 363 | int *result) |
| 364 | { |
| 365 | enum lttng_tracker_id_status status; |
| 366 | int value; |
| 367 | const char *string; |
| 368 | |
| 369 | switch (lttng_tracker_id_get_type(id)) { |
| 370 | case LTTNG_ID_ALL: |
| 371 | *result = -1; |
| 372 | return LTTNG_OK; |
| 373 | case LTTNG_ID_VALUE: |
| 374 | status = lttng_tracker_id_get_value(id, &value); |
| 375 | if (status != LTTNG_TRACKER_ID_STATUS_OK) { |
| 376 | return LTTNG_ERR_INVALID; |
| 377 | } |
| 378 | *result = id->value; |
| 379 | return LTTNG_OK; |
| 380 | case LTTNG_ID_STRING: |
| 381 | status = lttng_tracker_id_get_string(id, &string); |
| 382 | if (status != LTTNG_TRACKER_ID_STATUS_OK) { |
| 383 | return LTTNG_ERR_INVALID; |
| 384 | } |
| 385 | switch (tracker_type) { |
| 386 | case LTTNG_TRACKER_PID: |
| 387 | case LTTNG_TRACKER_VPID: |
| 388 | ERR("Lookup of tracker PID/VPID by name unsupported."); |
| 389 | return LTTNG_ERR_INVALID; |
| 390 | case LTTNG_TRACKER_UID: |
| 391 | case LTTNG_TRACKER_VUID: |
| 392 | DBG("Lookup of tracker UID/VUID by name."); |
| 393 | return lttng_lookup_user(string, result); |
| 394 | case LTTNG_TRACKER_GID: |
| 395 | case LTTNG_TRACKER_VGID: |
| 396 | DBG("Lookup of tracker GID/VGID by name."); |
| 397 | return lttng_lookup_group(string, result); |
| 398 | default: |
| 399 | return LTTNG_ERR_INVALID; |
| 400 | } |
| 401 | default: |
| 402 | return LTTNG_ERR_INVALID; |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | /* |
| 407 | * Protected by session mutex held by caller. |
| 408 | * On success, _ids and the ids it contains must be freed by the caller. |
| 409 | */ |
| 410 | int lttng_tracker_id_get_list(const struct lttng_tracker_list *tracker_list, |
| 411 | struct lttng_tracker_ids **_ids) |
| 412 | { |
| 413 | int retval = LTTNG_OK, ret; |
| 414 | struct lttng_tracker_list_node *n; |
| 415 | ssize_t count = 0, i = 0; |
| 416 | struct lttng_tracker_ids *ids = NULL; |
| 417 | struct lttng_tracker_id *id; |
| 418 | enum lttng_tracker_id_status status; |
| 419 | |
| 420 | switch (tracker_list->state) { |
| 421 | case LTTNG_TRACK_LIST: |
| 422 | cds_list_for_each_entry ( |
| 423 | n, &tracker_list->list_head, list_node) { |
| 424 | count++; |
| 425 | } |
| 426 | ids = lttng_tracker_ids_create(count); |
| 427 | if (ids == NULL) { |
| 428 | PERROR("Failed to allocate tracked ID list"); |
| 429 | retval = -LTTNG_ERR_NOMEM; |
| 430 | goto end; |
| 431 | } |
| 432 | cds_list_for_each_entry ( |
| 433 | n, &tracker_list->list_head, list_node) { |
| 434 | id = lttng_tracker_ids_get_pointer_of_index(ids, i); |
| 435 | if (!id) { |
| 436 | retval = -LTTNG_ERR_INVALID; |
| 437 | goto error; |
| 438 | } |
| 439 | |
| 440 | ret = lttng_tracker_id_copy(id, n->id); |
| 441 | if (ret) { |
| 442 | retval = -LTTNG_ERR_NOMEM; |
| 443 | goto error; |
| 444 | } |
| 445 | i++; |
| 446 | } |
| 447 | break; |
| 448 | case LTTNG_TRACK_ALL: |
| 449 | |
| 450 | ids = lttng_tracker_ids_create(1); |
| 451 | if (ids == NULL) { |
| 452 | PERROR("Failed to allocate tracked ID list"); |
| 453 | retval = -LTTNG_ERR_NOMEM; |
| 454 | goto end; |
| 455 | } |
| 456 | |
| 457 | id = lttng_tracker_ids_get_pointer_of_index(ids, 0); |
| 458 | status = lttng_tracker_id_set_all(id); |
| 459 | if (status != LTTNG_TRACKER_ID_STATUS_OK) { |
| 460 | ERR("Invalid tracker id for track all"); |
| 461 | retval = -LTTNG_ERR_INVALID; |
| 462 | goto error; |
| 463 | } |
| 464 | break; |
| 465 | case LTTNG_TRACK_NONE: |
| 466 | /* No ids track, so we return 0 element collection. */ |
| 467 | ids = lttng_tracker_ids_create(0); |
| 468 | if (ids == NULL) { |
| 469 | PERROR("alloc list ids"); |
| 470 | retval = -LTTNG_ERR_NOMEM; |
| 471 | goto end; |
| 472 | } |
| 473 | break; |
| 474 | } |
| 475 | *_ids = ids; |
| 476 | |
| 477 | end: |
| 478 | return retval; |
| 479 | |
| 480 | error: |
| 481 | lttng_tracker_ids_destroy(ids); |
| 482 | return retval; |
| 483 | } |
| 484 | |
| 485 | int lttng_tracker_id_set_list(struct lttng_tracker_list *tracker_list, |
| 486 | const struct lttng_tracker_ids *ids) |
| 487 | { |
| 488 | unsigned int i, count; |
| 489 | const struct lttng_tracker_id *id; |
| 490 | enum lttng_tracker_id_status status; |
| 491 | |
| 492 | assert(tracker_list); |
| 493 | assert(ids); |
| 494 | |
| 495 | lttng_tracker_list_reset(tracker_list); |
| 496 | |
| 497 | status = lttng_tracker_ids_get_count(ids, &count); |
| 498 | if (status != LTTNG_TRACKER_ID_STATUS_OK) { |
| 499 | return LTTNG_ERR_INVALID; |
| 500 | } |
| 501 | |
| 502 | if (count == 0) { |
| 503 | /* Set state to "track none". */ |
| 504 | tracker_list->state = LTTNG_TRACK_NONE; |
| 505 | return LTTNG_OK; |
| 506 | } |
| 507 | |
| 508 | if (count == 1) { |
| 509 | id = lttng_tracker_ids_get_at_index(ids, 0); |
| 510 | if (lttng_tracker_id_get_type(id) == LTTNG_ID_ALL) { |
| 511 | /* Track all. */ |
| 512 | return LTTNG_OK; |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | for (i = 0; i < count; i++) { |
| 517 | int ret; |
| 518 | id = lttng_tracker_ids_get_at_index(ids, i); |
| 519 | ret = lttng_tracker_list_add(tracker_list, id); |
| 520 | if (ret != LTTNG_OK) { |
| 521 | return ret; |
| 522 | } |
| 523 | } |
| 524 | return LTTNG_OK; |
| 525 | } |