| 1 | /* |
| 2 | * Copyright (C) 2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License, version 2 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along |
| 14 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _LGPL_SOURCE |
| 19 | #include <sys/types.h> |
| 20 | #include <pwd.h> |
| 21 | #include <grp.h> |
| 22 | #include <unistd.h> |
| 23 | |
| 24 | #include <common/defaults.h> |
| 25 | #include <common/hashtable/utils.h> |
| 26 | #include <common/hashtable/hashtable.h> |
| 27 | #include <common/error.h> |
| 28 | #include "tracker.h" |
| 29 | #include <lttng/lttng-error.h> |
| 30 | |
| 31 | #define FALLBACK_USER_BUFLEN 16384 |
| 32 | #define FALLBACK_GROUP_BUFLEN 16384 |
| 33 | |
| 34 | struct lttng_tracker_list *lttng_tracker_list_create(void) |
| 35 | { |
| 36 | struct lttng_tracker_list *t; |
| 37 | |
| 38 | t = zmalloc(sizeof(*t)); |
| 39 | if (!t) { |
| 40 | return NULL; |
| 41 | } |
| 42 | t->ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 43 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 44 | if (!t->ht) { |
| 45 | goto error; |
| 46 | } |
| 47 | CDS_INIT_LIST_HEAD(&t->list_head); |
| 48 | t->state = LTTNG_TRACK_ALL; |
| 49 | return t; |
| 50 | |
| 51 | error: |
| 52 | free(t); |
| 53 | return NULL; |
| 54 | } |
| 55 | |
| 56 | static |
| 57 | int match_tracker_key(struct cds_lfht_node *node, const void *key) |
| 58 | { |
| 59 | const struct lttng_tracker_id *tracker_key = key; |
| 60 | struct lttng_tracker_list_node *tracker_node; |
| 61 | |
| 62 | tracker_node = caa_container_of(node, struct lttng_tracker_list_node, |
| 63 | ht_node); |
| 64 | if (tracker_node->id.type != tracker_key->type) |
| 65 | return 0; |
| 66 | switch (tracker_node->id.type) { |
| 67 | case LTTNG_ID_ALL: |
| 68 | return 1; |
| 69 | case LTTNG_ID_VALUE: |
| 70 | if (tracker_node->id.value != tracker_key->value) |
| 71 | return 0; |
| 72 | break; |
| 73 | case LTTNG_ID_STRING: |
| 74 | if (strcmp(tracker_node->id.string, tracker_key->string) != 0) |
| 75 | return 0; |
| 76 | break; |
| 77 | default: |
| 78 | return 0; |
| 79 | } |
| 80 | return 1; |
| 81 | } |
| 82 | |
| 83 | static |
| 84 | unsigned long hash_tracker_key(const struct lttng_tracker_id *tracker_key) |
| 85 | { |
| 86 | unsigned long key_hash = 0; |
| 87 | |
| 88 | switch (tracker_key->type) { |
| 89 | case LTTNG_ID_ALL: |
| 90 | break; |
| 91 | case LTTNG_ID_VALUE: |
| 92 | key_hash ^= hash_key_ulong((void *)(unsigned long)tracker_key->value, |
| 93 | lttng_ht_seed); |
| 94 | break; |
| 95 | case LTTNG_ID_STRING: |
| 96 | key_hash ^= hash_key_str(tracker_key->string, lttng_ht_seed); |
| 97 | break; |
| 98 | case LTTNG_ID_UNKNOWN: |
| 99 | break; |
| 100 | } |
| 101 | key_hash ^= hash_key_ulong((void *)(unsigned long)tracker_key->type, |
| 102 | lttng_ht_seed); |
| 103 | return key_hash; |
| 104 | } |
| 105 | |
| 106 | static |
| 107 | struct lttng_tracker_id *lttng_tracker_list_lookup( |
| 108 | struct lttng_tracker_list *tracker_list, |
| 109 | const struct lttng_tracker_id *key) |
| 110 | { |
| 111 | struct lttng_tracker_list_node *list_node; |
| 112 | struct cds_lfht_iter iter; |
| 113 | struct cds_lfht_node *node; |
| 114 | |
| 115 | cds_lfht_lookup(tracker_list->ht, |
| 116 | hash_tracker_key(key), |
| 117 | match_tracker_key, |
| 118 | key, |
| 119 | &iter); |
| 120 | node = cds_lfht_iter_get_node(&iter); |
| 121 | if (!node) { |
| 122 | return NULL; |
| 123 | } |
| 124 | list_node = caa_container_of(node, struct lttng_tracker_list_node, |
| 125 | ht_node); |
| 126 | return &list_node->id; |
| 127 | } |
| 128 | |
| 129 | static |
| 130 | void destroy_list_node_rcu(struct rcu_head *head) |
| 131 | { |
| 132 | struct lttng_tracker_list_node *n = |
| 133 | caa_container_of(head, struct lttng_tracker_list_node, rcu_head); |
| 134 | |
| 135 | free(n->id.string); |
| 136 | free(n); |
| 137 | } |
| 138 | |
| 139 | static |
| 140 | void _lttng_tracker_list_remove(struct lttng_tracker_list *tracker_list, |
| 141 | struct lttng_tracker_list_node *n) |
| 142 | { |
| 143 | cds_list_del(&n->list_node); |
| 144 | |
| 145 | rcu_read_lock(); |
| 146 | cds_lfht_del(tracker_list->ht, &n->ht_node); |
| 147 | rcu_read_unlock(); |
| 148 | |
| 149 | call_rcu(&n->rcu_head, destroy_list_node_rcu); |
| 150 | } |
| 151 | |
| 152 | static |
| 153 | void lttng_tracker_list_reset(struct lttng_tracker_list *tracker_list) |
| 154 | { |
| 155 | struct lttng_tracker_list_node *n, *t; |
| 156 | |
| 157 | cds_list_for_each_entry_safe(n, t, &tracker_list->list_head, |
| 158 | list_node) { |
| 159 | _lttng_tracker_list_remove(tracker_list, n); |
| 160 | } |
| 161 | tracker_list->state = LTTNG_TRACK_ALL; |
| 162 | } |
| 163 | |
| 164 | /* Protected by session mutex held by caller. */ |
| 165 | int lttng_tracker_list_add(struct lttng_tracker_list *tracker_list, |
| 166 | const struct lttng_tracker_id *_id) |
| 167 | { |
| 168 | struct lttng_tracker_id *id; |
| 169 | struct lttng_tracker_list_node *n; |
| 170 | int ret; |
| 171 | |
| 172 | if (_id->type == LTTNG_ID_ALL) { |
| 173 | /* Track all, so remove each individual item. */ |
| 174 | lttng_tracker_list_reset(tracker_list); |
| 175 | return LTTNG_OK; |
| 176 | } |
| 177 | rcu_read_lock(); |
| 178 | id = lttng_tracker_list_lookup(tracker_list, _id); |
| 179 | rcu_read_unlock(); |
| 180 | if (id) { |
| 181 | return LTTNG_ERR_ID_TRACKED; |
| 182 | } |
| 183 | n = zmalloc(sizeof(*n)); |
| 184 | if (!n) { |
| 185 | return LTTNG_ERR_NOMEM; |
| 186 | } |
| 187 | n->id = *_id; |
| 188 | if (_id->type == LTTNG_ID_STRING) { |
| 189 | n->id.string = strdup(_id->string); |
| 190 | if (!n->id.string) { |
| 191 | ret = LTTNG_ERR_NOMEM; |
| 192 | goto error; |
| 193 | } |
| 194 | } else { |
| 195 | n->id.string = NULL; |
| 196 | } |
| 197 | |
| 198 | cds_list_add_tail(&n->list_node, &tracker_list->list_head); |
| 199 | tracker_list->state = LTTNG_TRACK_LIST; |
| 200 | |
| 201 | rcu_read_lock(); |
| 202 | cds_lfht_add(tracker_list->ht, hash_tracker_key(&n->id), &n->ht_node); |
| 203 | rcu_read_unlock(); |
| 204 | |
| 205 | return LTTNG_OK; |
| 206 | |
| 207 | error: |
| 208 | free(n); |
| 209 | return ret; |
| 210 | } |
| 211 | |
| 212 | /* Lookup and remove */ |
| 213 | /* Protected by session mutex held by caller. */ |
| 214 | int lttng_tracker_list_remove(struct lttng_tracker_list *tracker_list, |
| 215 | const struct lttng_tracker_id *_id) |
| 216 | { |
| 217 | struct lttng_tracker_id *id; |
| 218 | struct lttng_tracker_list_node *n; |
| 219 | |
| 220 | if (_id->type == LTTNG_ID_ALL) { |
| 221 | /* Untrack all. */ |
| 222 | lttng_tracker_list_reset(tracker_list); |
| 223 | /* Set state to "track none". */ |
| 224 | tracker_list->state = LTTNG_TRACK_NONE; |
| 225 | return LTTNG_OK; |
| 226 | } |
| 227 | |
| 228 | rcu_read_lock(); |
| 229 | id = lttng_tracker_list_lookup(tracker_list, _id); |
| 230 | if (!id) { |
| 231 | rcu_read_unlock(); |
| 232 | return LTTNG_ERR_ID_NOT_TRACKED; |
| 233 | } |
| 234 | n = caa_container_of(id, struct lttng_tracker_list_node, id); |
| 235 | _lttng_tracker_list_remove(tracker_list, n); |
| 236 | rcu_read_unlock(); |
| 237 | return LTTNG_OK; |
| 238 | } |
| 239 | |
| 240 | void lttng_tracker_list_destroy(struct lttng_tracker_list *tracker_list) |
| 241 | { |
| 242 | if (!tracker_list) |
| 243 | return; |
| 244 | lttng_tracker_list_reset(tracker_list); |
| 245 | cds_lfht_destroy(tracker_list->ht, NULL); |
| 246 | free(tracker_list); |
| 247 | } |
| 248 | |
| 249 | static |
| 250 | int lttng_lookup_user(const char *username, int *result) |
| 251 | { |
| 252 | struct passwd p, *pres; |
| 253 | int ret, retval = LTTNG_OK; |
| 254 | char *buf = NULL; |
| 255 | ssize_t buflen; |
| 256 | |
| 257 | buflen = sysconf(_SC_GETPW_R_SIZE_MAX); |
| 258 | if (buflen < 0) { |
| 259 | buflen = FALLBACK_USER_BUFLEN; |
| 260 | } |
| 261 | buf = zmalloc(buflen); |
| 262 | if (!buf) { |
| 263 | retval = LTTNG_ERR_NOMEM; |
| 264 | goto end; |
| 265 | } |
| 266 | for (;;) { |
| 267 | ret = getpwnam_r(username, &p, buf, buflen, &pres); |
| 268 | switch (ret) { |
| 269 | case EINTR: |
| 270 | continue; |
| 271 | case ERANGE: |
| 272 | buflen *= 2; |
| 273 | free(buf); |
| 274 | buf = zmalloc(buflen); |
| 275 | if (!buf) { |
| 276 | retval = LTTNG_ERR_NOMEM; |
| 277 | goto end; |
| 278 | } |
| 279 | continue; |
| 280 | default: |
| 281 | goto end_loop; |
| 282 | } |
| 283 | } |
| 284 | end_loop: |
| 285 | |
| 286 | switch (ret) { |
| 287 | case 0: |
| 288 | if (pres == NULL) { |
| 289 | retval = LTTNG_ERR_USER_NOT_FOUND; |
| 290 | } else { |
| 291 | *result = (int) p.pw_uid; |
| 292 | DBG("Lookup of tracker UID/VUID: name '%s' maps to id %d.", |
| 293 | username, *result); |
| 294 | retval = LTTNG_OK; |
| 295 | } |
| 296 | break; |
| 297 | case ENOENT: |
| 298 | case ESRCH: |
| 299 | case EBADF: |
| 300 | case EPERM: |
| 301 | retval = LTTNG_ERR_USER_NOT_FOUND; |
| 302 | break; |
| 303 | default: |
| 304 | retval = LTTNG_ERR_NOMEM; |
| 305 | } |
| 306 | end: |
| 307 | free(buf); |
| 308 | return retval; |
| 309 | } |
| 310 | |
| 311 | static |
| 312 | int lttng_lookup_group(const char *groupname, int *result) |
| 313 | { |
| 314 | struct group g, *gres; |
| 315 | int ret, retval = LTTNG_OK; |
| 316 | char *buf = NULL; |
| 317 | ssize_t buflen; |
| 318 | |
| 319 | buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
| 320 | if (buflen < 0) { |
| 321 | buflen = FALLBACK_GROUP_BUFLEN; |
| 322 | } |
| 323 | buf = zmalloc(buflen); |
| 324 | if (!buf) { |
| 325 | retval = LTTNG_ERR_NOMEM; |
| 326 | goto end; |
| 327 | } |
| 328 | for (;;) { |
| 329 | ret = getgrnam_r(groupname, &g, buf, buflen, &gres); |
| 330 | switch (ret) { |
| 331 | case EINTR: |
| 332 | continue; |
| 333 | case ERANGE: |
| 334 | buflen *= 2; |
| 335 | free(buf); |
| 336 | buf = zmalloc(buflen); |
| 337 | if (!buf) { |
| 338 | retval = LTTNG_ERR_NOMEM; |
| 339 | goto end; |
| 340 | } |
| 341 | continue; |
| 342 | default: |
| 343 | goto end_loop; |
| 344 | } |
| 345 | } |
| 346 | end_loop: |
| 347 | |
| 348 | switch (ret) { |
| 349 | case 0: |
| 350 | if (gres == NULL) { |
| 351 | retval = LTTNG_ERR_GROUP_NOT_FOUND; |
| 352 | } else { |
| 353 | *result = (int) g.gr_gid; |
| 354 | DBG("Lookup of tracker GID/GUID: name '%s' maps to id %d.", |
| 355 | groupname, *result); |
| 356 | retval = LTTNG_OK; |
| 357 | } |
| 358 | break; |
| 359 | case ENOENT: |
| 360 | case ESRCH: |
| 361 | case EBADF: |
| 362 | case EPERM: |
| 363 | retval = LTTNG_ERR_GROUP_NOT_FOUND; |
| 364 | break; |
| 365 | default: |
| 366 | retval = LTTNG_ERR_NOMEM; |
| 367 | } |
| 368 | end: |
| 369 | free(buf); |
| 370 | return retval; |
| 371 | } |
| 372 | |
| 373 | int lttng_tracker_id_lookup_string(enum lttng_tracker_type tracker_type, |
| 374 | const struct lttng_tracker_id *id, |
| 375 | int *result) |
| 376 | { |
| 377 | switch (id->type) { |
| 378 | case LTTNG_ID_ALL: |
| 379 | *result = -1; |
| 380 | return LTTNG_OK; |
| 381 | case LTTNG_ID_VALUE: |
| 382 | *result = id->value; |
| 383 | return LTTNG_OK; |
| 384 | case LTTNG_ID_STRING: |
| 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(id->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(id->string, result); |
| 398 | default: |
| 399 | return LTTNG_ERR_INVALID; |
| 400 | } |
| 401 | break; |
| 402 | default: |
| 403 | return LTTNG_ERR_INVALID; |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | /* Protected by session mutex held by caller. */ |
| 408 | /* On success, _ids and the strings it contains must be freed by caller. */ |
| 409 | ssize_t lttng_tracker_id_get_list(struct lttng_tracker_list *tracker_list, |
| 410 | struct lttng_tracker_id **_ids) |
| 411 | { |
| 412 | struct lttng_tracker_list_node *n; |
| 413 | ssize_t count = 0, i = 0, retval = 0; |
| 414 | struct lttng_tracker_id *ids; |
| 415 | |
| 416 | switch (tracker_list->state) { |
| 417 | case LTTNG_TRACK_LIST: |
| 418 | cds_list_for_each_entry(n, &tracker_list->list_head, list_node) { |
| 419 | count++; |
| 420 | } |
| 421 | ids = zmalloc(sizeof(*ids) * count); |
| 422 | if (ids == NULL) { |
| 423 | PERROR("alloc list ids"); |
| 424 | retval = -LTTNG_ERR_NOMEM; |
| 425 | goto end; |
| 426 | } |
| 427 | cds_list_for_each_entry(n, &tracker_list->list_head, list_node) { |
| 428 | ids[i].type = n->id.type; |
| 429 | ids[i].value = n->id.value; |
| 430 | if (ids[i].type == LTTNG_ID_STRING) { |
| 431 | ids[i].string = strdup(n->id.string); |
| 432 | if (!ids[i].string) { |
| 433 | retval = -LTTNG_ERR_NOMEM; |
| 434 | goto error; |
| 435 | } |
| 436 | } |
| 437 | i++; |
| 438 | } |
| 439 | *_ids = ids; |
| 440 | retval = count; |
| 441 | break; |
| 442 | case LTTNG_TRACK_ALL: |
| 443 | ids = zmalloc(sizeof(*ids)); |
| 444 | if (ids == NULL) { |
| 445 | PERROR("alloc list ids"); |
| 446 | retval = -LTTNG_ERR_NOMEM; |
| 447 | goto end; |
| 448 | } |
| 449 | ids->type = LTTNG_TRACK_ALL; |
| 450 | *_ids = ids; |
| 451 | retval = 1; |
| 452 | break; |
| 453 | case LTTNG_TRACK_NONE: |
| 454 | /* No ids track, so we return 0 element. */ |
| 455 | *_ids = NULL; |
| 456 | break; |
| 457 | } |
| 458 | end: |
| 459 | return retval; |
| 460 | |
| 461 | error: |
| 462 | for (i = 0; i < count; i++) { |
| 463 | free(ids[i].string); |
| 464 | } |
| 465 | free(ids); |
| 466 | return retval; |
| 467 | } |
| 468 | |
| 469 | int lttng_tracker_id_set_list(struct lttng_tracker_list *tracker_list, |
| 470 | struct lttng_tracker_id *_ids, |
| 471 | size_t count) |
| 472 | { |
| 473 | size_t i; |
| 474 | |
| 475 | lttng_tracker_list_reset(tracker_list); |
| 476 | if (count == 1 && _ids[0].type == LTTNG_ID_ALL) { |
| 477 | /* Track all. */ |
| 478 | return LTTNG_OK; |
| 479 | } |
| 480 | if (count == 0) { |
| 481 | /* Set state to "track none". */ |
| 482 | tracker_list->state = LTTNG_TRACK_NONE; |
| 483 | return LTTNG_OK; |
| 484 | } |
| 485 | for (i = 0; i < count; i++) { |
| 486 | struct lttng_tracker_id *id = &_ids[i]; |
| 487 | int ret; |
| 488 | |
| 489 | ret = lttng_tracker_list_add(tracker_list, id); |
| 490 | if (ret != LTTNG_OK) { |
| 491 | return ret; |
| 492 | } |
| 493 | } |
| 494 | return LTTNG_OK; |
| 495 | } |