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f8cc2132 MD |
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 | } |