event-rule: introduce event rule syscall
[lttng-tools.git] / src / common / event-rule / syscall.c
CommitLineData
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
20static 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
37static 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;
56end:
57 return valid;
58}
59
60static 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);
102end:
103 return ret;
104}
105
106static 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;
135end:
136 return is_equal;
137}
138
139static 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
188end:
189 free(bytecode);
190 return ret_code;
191}
192
193static 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
204static const struct lttng_filter_bytecode *
205lttng_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
216static struct lttng_event_exclusion *
217lttng_event_rule_syscall_generate_exclusions(
218 const struct lttng_event_rule *rule)
219{
220 /* Not supported. */
221 return NULL;
222}
223
224struct 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;
249end:
250 return rule;
251}
252
253LTTNG_HIDDEN
254ssize_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));
279 syscall_comm = (typeof(syscall_comm)) current_buffer_view.data;
280
281 if (!syscall_comm) {
282 ret = -1;
283 goto end;
284 }
285
286 rule = lttng_event_rule_syscall_create();
287 if (!rule) {
288 ERR("Failed to create event rule syscall");
289 ret = -1;
290 goto end;
291 }
292
293 /* Skip to payload. */
294 offset += current_buffer_view.size;
295
296 /* Map the pattern. */
297 current_buffer_view = lttng_buffer_view_from_view(
298 &view->buffer, offset, syscall_comm->pattern_len);
299 pattern = current_buffer_view.data;
300 if (!pattern) {
301 ret = -1;
302 goto end;
303 }
304
305 if (!lttng_buffer_view_contains_string(&current_buffer_view, pattern,
306 syscall_comm->pattern_len)) {
307 ret = -1;
308 goto end;
309 }
310
311 /* Skip after the pattern. */
312 offset += syscall_comm->pattern_len;
313
314 if (!syscall_comm->filter_expression_len) {
315 goto skip_filter_expression;
316 }
317
318 /* Map the filter_expression. */
319 current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset,
320 syscall_comm->filter_expression_len);
321 filter_expression = current_buffer_view.data;
322 if (!filter_expression) {
323 ret = -1;
324 goto end;
325 }
326
327 if (!lttng_buffer_view_contains_string(&current_buffer_view,
328 filter_expression,
329 syscall_comm->filter_expression_len)) {
330 ret = -1;
331 goto end;
332 }
333
334 /* Skip after the pattern. */
335 offset += syscall_comm->filter_expression_len;
336
337skip_filter_expression:
338
339 status = lttng_event_rule_syscall_set_pattern(rule, pattern);
340 if (status != LTTNG_EVENT_RULE_STATUS_OK) {
341 ERR("Failed to set event rule syscall pattern");
342 ret = -1;
343 goto end;
344 }
345
346 if (filter_expression) {
347 status = lttng_event_rule_syscall_set_filter(
348 rule, filter_expression);
349 if (status != LTTNG_EVENT_RULE_STATUS_OK) {
350 ERR("Failed to set event rule syscall pattern");
351 ret = -1;
352 goto end;
353 }
354 }
355
356 *_event_rule = rule;
357 rule = NULL;
358 ret = offset;
359end:
360 lttng_event_rule_destroy(rule);
361 return ret;
362}
363
364enum lttng_event_rule_status lttng_event_rule_syscall_set_pattern(
365 struct lttng_event_rule *rule, const char *pattern)
366{
367 char *pattern_copy = NULL;
368 struct lttng_event_rule_syscall *syscall;
369 enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
370
371 if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern ||
372 strlen(pattern) == 0) {
373 status = LTTNG_EVENT_RULE_STATUS_INVALID;
374 goto end;
375 }
376
377 syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
378 pattern_copy = strdup(pattern);
379 if (!pattern_copy) {
380 status = LTTNG_EVENT_RULE_STATUS_ERROR;
381 goto end;
382 }
383
384 if (syscall->pattern) {
385 free(syscall->pattern);
386 }
387
388 syscall->pattern = pattern_copy;
389 pattern_copy = NULL;
390end:
391 return status;
392}
393
394enum lttng_event_rule_status lttng_event_rule_syscall_get_pattern(
395 const struct lttng_event_rule *rule, const char **pattern)
396{
397 struct lttng_event_rule_syscall *syscall;
398 enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
399
400 if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern) {
401 status = LTTNG_EVENT_RULE_STATUS_INVALID;
402 goto end;
403 }
404
405 syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
406 if (!syscall->pattern) {
407 status = LTTNG_EVENT_RULE_STATUS_UNSET;
408 goto end;
409 }
410
411 *pattern = syscall->pattern;
412end:
413 return status;
414}
415
416enum lttng_event_rule_status lttng_event_rule_syscall_set_filter(
417 struct lttng_event_rule *rule, const char *expression)
418{
419 char *expression_copy = NULL;
420 struct lttng_event_rule_syscall *syscall;
421 enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
422
423 /* TODO: validate that the passed expression is valid. */
424
425 if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression ||
426 strlen(expression) == 0) {
427 status = LTTNG_EVENT_RULE_STATUS_INVALID;
428 goto end;
429 }
430
431 syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
432 expression_copy = strdup(expression);
433 if (!expression_copy) {
434 status = LTTNG_EVENT_RULE_STATUS_ERROR;
435 goto end;
436 }
437
438 if (syscall->filter_expression) {
439 free(syscall->filter_expression);
440 }
441
442 syscall->filter_expression = expression_copy;
443 expression_copy = NULL;
444end:
445 return status;
446}
447
448enum lttng_event_rule_status lttng_event_rule_syscall_get_filter(
449 const struct lttng_event_rule *rule, const char **expression)
450{
451 struct lttng_event_rule_syscall *syscall;
452 enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
453
454 if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression) {
455 status = LTTNG_EVENT_RULE_STATUS_INVALID;
456 goto end;
457 }
458
459 syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
460 if (!syscall->filter_expression) {
461 status = LTTNG_EVENT_RULE_STATUS_UNSET;
462 goto end;
463 }
464
465 *expression = syscall->filter_expression;
466end:
467 return status;
468}
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