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e6a39346 JR |
1 | /* |
2 | * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> | |
3 | * | |
4 | * SPDX-License-Identifier: LGPL-2.1-only | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <assert.h> | |
58daac01 | 9 | #include <common/credentials.h> |
e6a39346 JR |
10 | #include <common/error.h> |
11 | #include <common/macros.h> | |
12 | #include <common/payload.h> | |
13 | #include <common/payload-view.h> | |
14 | #include <common/runas.h> | |
959e3c66 JR |
15 | #include <common/hashtable/hashtable.h> |
16 | #include <common/hashtable/utils.h> | |
e6a39346 JR |
17 | #include <lttng/event-rule/event-rule-internal.h> |
18 | #include <lttng/event-rule/syscall-internal.h> | |
19 | ||
20 | #define IS_SYSCALL_EVENT_RULE(rule) \ | |
21 | (lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_SYSCALL) | |
22 | ||
23 | static void lttng_event_rule_syscall_destroy(struct lttng_event_rule *rule) | |
24 | { | |
25 | struct lttng_event_rule_syscall *syscall; | |
26 | ||
27 | if (rule == NULL) { | |
28 | return; | |
29 | } | |
30 | ||
31 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
32 | ||
33 | free(syscall->pattern); | |
34 | free(syscall->filter_expression); | |
35 | free(syscall->internal_filter.filter); | |
36 | free(syscall->internal_filter.bytecode); | |
37 | free(syscall); | |
38 | } | |
39 | ||
40 | static bool lttng_event_rule_syscall_validate( | |
41 | const struct lttng_event_rule *rule) | |
42 | { | |
43 | bool valid = false; | |
44 | struct lttng_event_rule_syscall *syscall; | |
45 | ||
46 | if (!rule) { | |
47 | goto end; | |
48 | } | |
49 | ||
50 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
51 | ||
52 | /* Required field. */ | |
53 | if (!syscall->pattern) { | |
54 | ERR("Invalid syscall event rule: a pattern must be set."); | |
55 | goto end; | |
56 | } | |
57 | ||
58 | valid = true; | |
59 | end: | |
60 | return valid; | |
61 | } | |
62 | ||
63 | static int lttng_event_rule_syscall_serialize( | |
64 | const struct lttng_event_rule *rule, | |
65 | struct lttng_payload *payload) | |
66 | { | |
67 | int ret; | |
68 | size_t pattern_len, filter_expression_len; | |
69 | struct lttng_event_rule_syscall *syscall; | |
70 | struct lttng_event_rule_syscall_comm syscall_comm; | |
71 | ||
72 | if (!rule || !IS_SYSCALL_EVENT_RULE(rule)) { | |
73 | ret = -1; | |
74 | goto end; | |
75 | } | |
76 | ||
77 | DBG("Serializing syscall event rule"); | |
78 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
79 | ||
80 | pattern_len = strlen(syscall->pattern) + 1; | |
81 | ||
82 | if (syscall->filter_expression != NULL) { | |
83 | filter_expression_len = strlen(syscall->filter_expression) + 1; | |
84 | } else { | |
85 | filter_expression_len = 0; | |
86 | } | |
87 | ||
88 | syscall_comm.pattern_len = pattern_len; | |
89 | syscall_comm.filter_expression_len = filter_expression_len; | |
90 | ||
91 | ret = lttng_dynamic_buffer_append( | |
92 | &payload->buffer, &syscall_comm, sizeof(syscall_comm)); | |
93 | if (ret) { | |
94 | goto end; | |
95 | } | |
96 | ||
97 | ret = lttng_dynamic_buffer_append( | |
98 | &payload->buffer, syscall->pattern, pattern_len); | |
99 | if (ret) { | |
100 | goto end; | |
101 | } | |
102 | ||
103 | ret = lttng_dynamic_buffer_append(&payload->buffer, | |
104 | syscall->filter_expression, filter_expression_len); | |
105 | end: | |
106 | return ret; | |
107 | } | |
108 | ||
109 | static bool lttng_event_rule_syscall_is_equal(const struct lttng_event_rule *_a, | |
110 | const struct lttng_event_rule *_b) | |
111 | { | |
112 | bool is_equal = false; | |
113 | struct lttng_event_rule_syscall *a, *b; | |
114 | ||
115 | a = container_of(_a, struct lttng_event_rule_syscall, parent); | |
116 | b = container_of(_b, struct lttng_event_rule_syscall, parent); | |
117 | ||
118 | if (!!a->filter_expression != !!b->filter_expression) { | |
119 | goto end; | |
120 | } | |
121 | ||
122 | assert(a->pattern); | |
123 | assert(b->pattern); | |
124 | if (strcmp(a->pattern, b->pattern)) { | |
125 | goto end; | |
126 | } | |
127 | ||
128 | if (a->filter_expression && b->filter_expression) { | |
129 | if (strcmp(a->filter_expression, b->filter_expression)) { | |
130 | goto end; | |
131 | } | |
132 | } else if (!!a->filter_expression != !!b->filter_expression) { | |
133 | /* One is set and not the other. */ | |
134 | goto end; | |
135 | } | |
136 | ||
137 | is_equal = true; | |
138 | end: | |
139 | return is_equal; | |
140 | } | |
141 | ||
142 | static enum lttng_error_code lttng_event_rule_syscall_generate_filter_bytecode( | |
58daac01 JR |
143 | struct lttng_event_rule *rule, |
144 | const struct lttng_credentials *creds) | |
e6a39346 JR |
145 | { |
146 | int ret; | |
147 | enum lttng_error_code ret_code = LTTNG_OK; | |
148 | struct lttng_event_rule_syscall *syscall; | |
149 | enum lttng_event_rule_status status; | |
150 | const char *filter; | |
151 | struct lttng_filter_bytecode *bytecode = NULL; | |
152 | ||
153 | assert(rule); | |
154 | ||
155 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
156 | ||
157 | /* Generate the filter bytecode. */ | |
158 | status = lttng_event_rule_syscall_get_filter(rule, &filter); | |
159 | if (status == LTTNG_EVENT_RULE_STATUS_UNSET) { | |
160 | filter = NULL; | |
161 | } else if (status != LTTNG_EVENT_RULE_STATUS_OK) { | |
162 | ret_code = LTTNG_ERR_FILTER_INVAL; | |
163 | goto end; | |
164 | } | |
165 | ||
166 | if (filter && filter[0] == '\0') { | |
167 | ret_code = LTTNG_ERR_FILTER_INVAL; | |
168 | goto end; | |
169 | } | |
170 | ||
171 | if (filter == NULL) { | |
172 | /* Nothing to do. */ | |
173 | ret = LTTNG_OK; | |
174 | goto end; | |
175 | } | |
176 | ||
177 | syscall->internal_filter.filter = strdup(filter); | |
178 | if (syscall->internal_filter.filter == NULL) { | |
179 | ret_code = LTTNG_ERR_NOMEM; | |
180 | goto end; | |
181 | } | |
182 | ||
183 | ret = run_as_generate_filter_bytecode( | |
58daac01 | 184 | syscall->internal_filter.filter, creds, &bytecode); |
e6a39346 JR |
185 | if (ret) { |
186 | ret_code = LTTNG_ERR_FILTER_INVAL; | |
187 | } | |
188 | ||
189 | syscall->internal_filter.bytecode = bytecode; | |
190 | bytecode = NULL; | |
191 | ||
192 | end: | |
193 | free(bytecode); | |
194 | return ret_code; | |
195 | } | |
196 | ||
197 | static const char *lttng_event_rule_syscall_get_internal_filter( | |
198 | const struct lttng_event_rule *rule) | |
199 | { | |
200 | struct lttng_event_rule_syscall *syscall; | |
201 | ||
202 | assert(rule); | |
203 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
204 | ||
205 | return syscall->internal_filter.filter; | |
206 | } | |
207 | ||
208 | static const struct lttng_filter_bytecode * | |
209 | lttng_event_rule_syscall_get_internal_filter_bytecode( | |
210 | const struct lttng_event_rule *rule) | |
211 | { | |
212 | struct lttng_event_rule_syscall *syscall; | |
213 | ||
214 | assert(rule); | |
215 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
216 | ||
217 | return syscall->internal_filter.bytecode; | |
218 | } | |
219 | ||
220 | static struct lttng_event_exclusion * | |
221 | lttng_event_rule_syscall_generate_exclusions( | |
222 | const struct lttng_event_rule *rule) | |
223 | { | |
224 | /* Not supported. */ | |
225 | return NULL; | |
226 | } | |
227 | ||
959e3c66 JR |
228 | static unsigned long |
229 | lttng_event_rule_syscall_hash( | |
230 | const struct lttng_event_rule *rule) | |
231 | { | |
232 | unsigned long hash; | |
233 | struct lttng_event_rule_syscall *syscall_rule = | |
234 | container_of(rule, typeof(*syscall_rule), parent); | |
235 | ||
236 | hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_SYSCALL, | |
237 | lttng_ht_seed); | |
238 | hash ^= hash_key_str(syscall_rule->pattern, lttng_ht_seed); | |
239 | if (syscall_rule->filter_expression) { | |
240 | hash ^= hash_key_str(syscall_rule->filter_expression, | |
241 | lttng_ht_seed); | |
242 | } | |
243 | ||
244 | return hash; | |
245 | } | |
246 | ||
e6a39346 JR |
247 | struct lttng_event_rule *lttng_event_rule_syscall_create() |
248 | { | |
249 | struct lttng_event_rule *rule = NULL; | |
250 | struct lttng_event_rule_syscall *syscall_rule; | |
251 | ||
252 | syscall_rule = zmalloc(sizeof(struct lttng_event_rule_syscall)); | |
253 | if (!syscall_rule) { | |
254 | goto end; | |
255 | } | |
256 | ||
257 | rule = &syscall_rule->parent; | |
258 | lttng_event_rule_init( | |
259 | &syscall_rule->parent, LTTNG_EVENT_RULE_TYPE_SYSCALL); | |
260 | syscall_rule->parent.validate = lttng_event_rule_syscall_validate; | |
261 | syscall_rule->parent.serialize = lttng_event_rule_syscall_serialize; | |
262 | syscall_rule->parent.equal = lttng_event_rule_syscall_is_equal; | |
263 | syscall_rule->parent.destroy = lttng_event_rule_syscall_destroy; | |
264 | syscall_rule->parent.generate_filter_bytecode = | |
265 | lttng_event_rule_syscall_generate_filter_bytecode; | |
266 | syscall_rule->parent.get_filter = | |
267 | lttng_event_rule_syscall_get_internal_filter; | |
268 | syscall_rule->parent.get_filter_bytecode = | |
269 | lttng_event_rule_syscall_get_internal_filter_bytecode; | |
270 | syscall_rule->parent.generate_exclusions = | |
271 | lttng_event_rule_syscall_generate_exclusions; | |
959e3c66 | 272 | syscall_rule->parent.hash = lttng_event_rule_syscall_hash; |
e6a39346 JR |
273 | end: |
274 | return rule; | |
275 | } | |
276 | ||
277 | LTTNG_HIDDEN | |
278 | ssize_t lttng_event_rule_syscall_create_from_payload( | |
279 | struct lttng_payload_view *view, | |
280 | struct lttng_event_rule **_event_rule) | |
281 | { | |
282 | ssize_t ret, offset = 0; | |
283 | enum lttng_event_rule_status status; | |
284 | const struct lttng_event_rule_syscall_comm *syscall_comm; | |
285 | const char *pattern; | |
286 | const char *filter_expression = NULL; | |
287 | struct lttng_buffer_view current_buffer_view; | |
288 | struct lttng_event_rule *rule = NULL; | |
289 | ||
290 | if (!_event_rule) { | |
291 | ret = -1; | |
292 | goto end; | |
293 | } | |
294 | ||
295 | if (view->buffer.size < sizeof(*syscall_comm)) { | |
296 | ERR("Failed to initialize from malformed event rule syscall: buffer too short to contain header"); | |
297 | ret = -1; | |
298 | goto end; | |
299 | } | |
300 | ||
301 | current_buffer_view = lttng_buffer_view_from_view( | |
302 | &view->buffer, offset, sizeof(*syscall_comm)); | |
3e6e0df2 | 303 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
e6a39346 JR |
304 | ret = -1; |
305 | goto end; | |
306 | } | |
307 | ||
3e6e0df2 | 308 | syscall_comm = (typeof(syscall_comm)) current_buffer_view.data; |
e6a39346 JR |
309 | rule = lttng_event_rule_syscall_create(); |
310 | if (!rule) { | |
311 | ERR("Failed to create event rule syscall"); | |
312 | ret = -1; | |
313 | goto end; | |
314 | } | |
315 | ||
316 | /* Skip to payload. */ | |
317 | offset += current_buffer_view.size; | |
318 | ||
319 | /* Map the pattern. */ | |
320 | current_buffer_view = lttng_buffer_view_from_view( | |
321 | &view->buffer, offset, syscall_comm->pattern_len); | |
3e6e0df2 | 322 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
e6a39346 JR |
323 | ret = -1; |
324 | goto end; | |
325 | } | |
326 | ||
3e6e0df2 | 327 | pattern = current_buffer_view.data; |
e6a39346 JR |
328 | if (!lttng_buffer_view_contains_string(¤t_buffer_view, pattern, |
329 | syscall_comm->pattern_len)) { | |
330 | ret = -1; | |
331 | goto end; | |
332 | } | |
333 | ||
334 | /* Skip after the pattern. */ | |
335 | offset += syscall_comm->pattern_len; | |
336 | ||
337 | if (!syscall_comm->filter_expression_len) { | |
338 | goto skip_filter_expression; | |
339 | } | |
340 | ||
341 | /* Map the filter_expression. */ | |
342 | current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset, | |
343 | syscall_comm->filter_expression_len); | |
3e6e0df2 | 344 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
e6a39346 JR |
345 | ret = -1; |
346 | goto end; | |
347 | } | |
348 | ||
3e6e0df2 | 349 | filter_expression = current_buffer_view.data; |
e6a39346 JR |
350 | if (!lttng_buffer_view_contains_string(¤t_buffer_view, |
351 | filter_expression, | |
352 | syscall_comm->filter_expression_len)) { | |
353 | ret = -1; | |
354 | goto end; | |
355 | } | |
356 | ||
357 | /* Skip after the pattern. */ | |
358 | offset += syscall_comm->filter_expression_len; | |
359 | ||
360 | skip_filter_expression: | |
361 | ||
362 | status = lttng_event_rule_syscall_set_pattern(rule, pattern); | |
363 | if (status != LTTNG_EVENT_RULE_STATUS_OK) { | |
364 | ERR("Failed to set event rule syscall pattern"); | |
365 | ret = -1; | |
366 | goto end; | |
367 | } | |
368 | ||
369 | if (filter_expression) { | |
370 | status = lttng_event_rule_syscall_set_filter( | |
371 | rule, filter_expression); | |
372 | if (status != LTTNG_EVENT_RULE_STATUS_OK) { | |
373 | ERR("Failed to set event rule syscall pattern"); | |
374 | ret = -1; | |
375 | goto end; | |
376 | } | |
377 | } | |
378 | ||
379 | *_event_rule = rule; | |
380 | rule = NULL; | |
381 | ret = offset; | |
382 | end: | |
383 | lttng_event_rule_destroy(rule); | |
384 | return ret; | |
385 | } | |
386 | ||
387 | enum lttng_event_rule_status lttng_event_rule_syscall_set_pattern( | |
388 | struct lttng_event_rule *rule, const char *pattern) | |
389 | { | |
390 | char *pattern_copy = NULL; | |
391 | struct lttng_event_rule_syscall *syscall; | |
392 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
393 | ||
394 | if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern || | |
395 | strlen(pattern) == 0) { | |
396 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
397 | goto end; | |
398 | } | |
399 | ||
400 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
401 | pattern_copy = strdup(pattern); | |
402 | if (!pattern_copy) { | |
403 | status = LTTNG_EVENT_RULE_STATUS_ERROR; | |
404 | goto end; | |
405 | } | |
406 | ||
407 | if (syscall->pattern) { | |
408 | free(syscall->pattern); | |
409 | } | |
410 | ||
411 | syscall->pattern = pattern_copy; | |
412 | pattern_copy = NULL; | |
413 | end: | |
414 | return status; | |
415 | } | |
416 | ||
417 | enum lttng_event_rule_status lttng_event_rule_syscall_get_pattern( | |
418 | const struct lttng_event_rule *rule, const char **pattern) | |
419 | { | |
420 | struct lttng_event_rule_syscall *syscall; | |
421 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
422 | ||
423 | if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern) { | |
424 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
425 | goto end; | |
426 | } | |
427 | ||
428 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
429 | if (!syscall->pattern) { | |
430 | status = LTTNG_EVENT_RULE_STATUS_UNSET; | |
431 | goto end; | |
432 | } | |
433 | ||
434 | *pattern = syscall->pattern; | |
435 | end: | |
436 | return status; | |
437 | } | |
438 | ||
439 | enum lttng_event_rule_status lttng_event_rule_syscall_set_filter( | |
440 | struct lttng_event_rule *rule, const char *expression) | |
441 | { | |
442 | char *expression_copy = NULL; | |
443 | struct lttng_event_rule_syscall *syscall; | |
444 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
445 | ||
446 | /* TODO: validate that the passed expression is valid. */ | |
447 | ||
448 | if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression || | |
449 | strlen(expression) == 0) { | |
450 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
451 | goto end; | |
452 | } | |
453 | ||
454 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
455 | expression_copy = strdup(expression); | |
456 | if (!expression_copy) { | |
457 | status = LTTNG_EVENT_RULE_STATUS_ERROR; | |
458 | goto end; | |
459 | } | |
460 | ||
461 | if (syscall->filter_expression) { | |
462 | free(syscall->filter_expression); | |
463 | } | |
464 | ||
465 | syscall->filter_expression = expression_copy; | |
466 | expression_copy = NULL; | |
467 | end: | |
468 | return status; | |
469 | } | |
470 | ||
471 | enum lttng_event_rule_status lttng_event_rule_syscall_get_filter( | |
472 | const struct lttng_event_rule *rule, const char **expression) | |
473 | { | |
474 | struct lttng_event_rule_syscall *syscall; | |
475 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
476 | ||
477 | if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression) { | |
478 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
479 | goto end; | |
480 | } | |
481 | ||
482 | syscall = container_of(rule, struct lttng_event_rule_syscall, parent); | |
483 | if (!syscall->filter_expression) { | |
484 | status = LTTNG_EVENT_RULE_STATUS_UNSET; | |
485 | goto end; | |
486 | } | |
487 | ||
488 | *expression = syscall->filter_expression; | |
489 | end: | |
490 | return status; | |
491 | } |