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