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077192fd 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> |
077192fd 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> | |
15 | #include <ctype.h> | |
16 | #include <lttng/constant.h> | |
17 | #include <lttng/event-rule/event-rule-internal.h> | |
18 | #include <lttng/event-rule/kprobe-internal.h> | |
19 | #include <lttng/kernel-probe.h> | |
20 | #include <lttng/kernel-probe-internal.h> | |
21 | #include <stdio.h> | |
22 | ||
23 | #define IS_KPROBE_EVENT_RULE(rule) \ | |
24 | (lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KPROBE) | |
25 | ||
26 | #if (LTTNG_SYMBOL_NAME_LEN == 256) | |
27 | #define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255" | |
28 | #endif | |
29 | ||
30 | static void lttng_event_rule_kprobe_destroy(struct lttng_event_rule *rule) | |
31 | { | |
32 | struct lttng_event_rule_kprobe *kprobe; | |
33 | ||
34 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
35 | ||
36 | lttng_kernel_probe_location_destroy(kprobe->location); | |
37 | free(kprobe->name); | |
38 | free(kprobe); | |
39 | } | |
40 | ||
41 | static bool lttng_event_rule_kprobe_validate( | |
42 | const struct lttng_event_rule *rule) | |
43 | { | |
44 | bool valid = false; | |
45 | struct lttng_event_rule_kprobe *kprobe; | |
46 | ||
47 | if (!rule) { | |
48 | goto end; | |
49 | } | |
50 | ||
51 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
52 | ||
53 | /* Required field. */ | |
54 | if (!kprobe->name) { | |
55 | ERR("Invalid name event rule: a name must be set."); | |
56 | goto end; | |
57 | } | |
58 | ||
59 | /* Required field. */ | |
60 | if(!kprobe->location) { | |
61 | ERR("Invalid name event rule: a location must be set."); | |
62 | goto end; | |
63 | } | |
64 | ||
65 | valid = true; | |
66 | end: | |
67 | return valid; | |
68 | } | |
69 | ||
70 | static int lttng_event_rule_kprobe_serialize( | |
71 | const struct lttng_event_rule *rule, | |
72 | struct lttng_payload *payload) | |
73 | { | |
74 | int ret; | |
75 | size_t name_len, header_offset, size_before_location; | |
76 | struct lttng_event_rule_kprobe *kprobe; | |
77 | struct lttng_event_rule_kprobe_comm kprobe_comm; | |
78 | struct lttng_event_rule_kprobe_comm *header; | |
79 | ||
80 | if (!rule || !IS_KPROBE_EVENT_RULE(rule)) { | |
81 | ret = -1; | |
82 | goto end; | |
83 | } | |
84 | ||
85 | header_offset = payload->buffer.size; | |
86 | ||
87 | DBG("Serializing kprobe event rule."); | |
88 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
89 | ||
90 | name_len = strlen(kprobe->name) + 1; | |
91 | kprobe_comm.name_len = name_len; | |
92 | ||
93 | ret = lttng_dynamic_buffer_append( | |
94 | &payload->buffer, &kprobe_comm, sizeof(kprobe_comm)); | |
95 | if (ret) { | |
96 | goto end; | |
97 | } | |
98 | ||
99 | ret = lttng_dynamic_buffer_append(&payload->buffer, kprobe->name, name_len); | |
100 | if (ret) { | |
101 | goto end; | |
102 | } | |
103 | ||
104 | size_before_location = payload->buffer.size; | |
105 | ||
106 | ret = lttng_kernel_probe_location_serialize(kprobe->location, payload); | |
107 | if (ret < 0) { | |
108 | goto end; | |
109 | } | |
110 | ||
111 | /* Update the header regarding the probe size. */ | |
112 | header = (struct lttng_event_rule_kprobe_comm*) ( | |
113 | (char *) payload->buffer.data + header_offset); | |
114 | header->location_len = payload->buffer.size - size_before_location; | |
115 | ||
116 | ret = 0; | |
117 | ||
118 | end: | |
119 | return ret; | |
120 | } | |
121 | ||
122 | static bool lttng_event_rule_kprobe_is_equal(const struct lttng_event_rule *_a, | |
123 | const struct lttng_event_rule *_b) | |
124 | { | |
125 | bool is_equal = false; | |
126 | struct lttng_event_rule_kprobe *a, *b; | |
127 | ||
128 | a = container_of(_a, struct lttng_event_rule_kprobe, parent); | |
129 | b = container_of(_b, struct lttng_event_rule_kprobe, parent); | |
130 | ||
131 | /* Quick checks */ | |
132 | if (!!a->name != !!b->name) { | |
133 | goto end; | |
134 | } | |
135 | ||
136 | /* Long check */ | |
137 | assert(a->name); | |
138 | assert(b->name); | |
139 | if (strcmp(a->name, b->name)) { | |
140 | goto end; | |
141 | } | |
142 | ||
143 | is_equal = lttng_kernel_probe_location_is_equal( | |
144 | a->location, b->location); | |
145 | end: | |
146 | return is_equal; | |
147 | } | |
148 | ||
149 | static enum lttng_error_code lttng_event_rule_kprobe_generate_filter_bytecode( | |
58daac01 JR |
150 | struct lttng_event_rule *rule, |
151 | const struct lttng_credentials *creds) | |
077192fd JR |
152 | { |
153 | /* Nothing to do. */ | |
154 | return LTTNG_OK; | |
155 | } | |
156 | ||
157 | static const char *lttng_event_rule_kprobe_get_filter( | |
158 | const struct lttng_event_rule *rule) | |
159 | { | |
160 | /* Not supported. */ | |
161 | return NULL; | |
162 | } | |
163 | ||
164 | static const struct lttng_filter_bytecode * | |
165 | lttng_event_rule_kprobe_get_filter_bytecode(const struct lttng_event_rule *rule) | |
166 | { | |
167 | /* Not supported. */ | |
168 | return NULL; | |
169 | } | |
170 | ||
171 | static struct lttng_event_exclusion * | |
172 | lttng_event_rule_kprobe_generate_exclusions(const struct lttng_event_rule *rule) | |
173 | { | |
174 | /* Not supported. */ | |
175 | return NULL; | |
176 | } | |
177 | ||
178 | struct lttng_event_rule *lttng_event_rule_kprobe_create() | |
179 | { | |
180 | struct lttng_event_rule *rule = NULL; | |
181 | struct lttng_event_rule_kprobe *krule; | |
182 | ||
183 | krule = zmalloc(sizeof(struct lttng_event_rule_kprobe)); | |
184 | if (!krule) { | |
185 | goto end; | |
186 | } | |
187 | ||
188 | rule = &krule->parent; | |
189 | lttng_event_rule_init(&krule->parent, LTTNG_EVENT_RULE_TYPE_KPROBE); | |
190 | krule->parent.validate = lttng_event_rule_kprobe_validate; | |
191 | krule->parent.serialize = lttng_event_rule_kprobe_serialize; | |
192 | krule->parent.equal = lttng_event_rule_kprobe_is_equal; | |
193 | krule->parent.destroy = lttng_event_rule_kprobe_destroy; | |
194 | krule->parent.generate_filter_bytecode = | |
195 | lttng_event_rule_kprobe_generate_filter_bytecode; | |
196 | krule->parent.get_filter = lttng_event_rule_kprobe_get_filter; | |
197 | krule->parent.get_filter_bytecode = | |
198 | lttng_event_rule_kprobe_get_filter_bytecode; | |
199 | krule->parent.generate_exclusions = | |
200 | lttng_event_rule_kprobe_generate_exclusions; | |
201 | end: | |
202 | return rule; | |
203 | } | |
204 | ||
205 | LTTNG_HIDDEN | |
206 | ssize_t lttng_event_rule_kprobe_create_from_payload( | |
207 | struct lttng_payload_view *view, | |
208 | struct lttng_event_rule **_event_rule) | |
209 | { | |
210 | ssize_t ret, offset = 0; | |
211 | enum lttng_event_rule_status status; | |
212 | const struct lttng_event_rule_kprobe_comm *kprobe_comm; | |
213 | const char *name; | |
214 | struct lttng_buffer_view current_buffer_view; | |
215 | struct lttng_event_rule *rule = NULL; | |
216 | struct lttng_event_rule_kprobe *kprobe = NULL; | |
217 | struct lttng_kernel_probe_location *location; | |
218 | ||
219 | if (!_event_rule) { | |
220 | ret = -1; | |
221 | goto end; | |
222 | } | |
223 | ||
3e6e0df2 JG |
224 | current_buffer_view = lttng_buffer_view_from_view( |
225 | &view->buffer, offset, sizeof(*kprobe_comm)); | |
226 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { | |
077192fd JR |
227 | ERR("Failed to initialize from malformed event rule kprobe: buffer too short to contain header."); |
228 | ret = -1; | |
229 | goto end; | |
230 | } | |
231 | ||
077192fd | 232 | kprobe_comm = (typeof(kprobe_comm)) current_buffer_view.data; |
077192fd JR |
233 | |
234 | rule = lttng_event_rule_kprobe_create(); | |
235 | if (!rule) { | |
236 | ERR("Failed to create event rule kprobe."); | |
237 | ret = -1; | |
238 | goto end; | |
239 | } | |
240 | ||
241 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
242 | ||
243 | /* Skip to payload */ | |
244 | offset += current_buffer_view.size; | |
245 | ||
246 | { | |
247 | /* Map the name. */ | |
248 | struct lttng_payload_view current_payload_view = | |
249 | lttng_payload_view_from_view(view, offset, | |
250 | kprobe_comm->name_len); | |
251 | ||
3e6e0df2 | 252 | if (!lttng_payload_view_is_valid(¤t_payload_view)) { |
077192fd JR |
253 | ret = -1; |
254 | goto end; | |
255 | } | |
256 | ||
3e6e0df2 | 257 | name = current_payload_view.buffer.data; |
077192fd JR |
258 | if (!lttng_buffer_view_contains_string( |
259 | ¤t_payload_view.buffer, name, | |
260 | kprobe_comm->name_len)) { | |
261 | ret = -1; | |
262 | goto end; | |
263 | } | |
264 | } | |
265 | ||
266 | /* Skip after the name. */ | |
267 | offset += kprobe_comm->name_len; | |
268 | ||
269 | /* Map the kernel probe location. */ | |
270 | { | |
271 | struct lttng_payload_view current_payload_view = | |
272 | lttng_payload_view_from_view(view, offset, | |
273 | kprobe_comm->location_len); | |
274 | ||
3e6e0df2 JG |
275 | if (!lttng_payload_view_is_valid(¤t_payload_view)) { |
276 | ret = -1; | |
277 | goto end; | |
278 | } | |
279 | ||
077192fd JR |
280 | ret = lttng_kernel_probe_location_create_from_payload( |
281 | ¤t_payload_view, &location); | |
282 | if (ret < 0) { | |
283 | ret = -1; | |
284 | goto end; | |
285 | } | |
286 | } | |
287 | ||
288 | if (ret != kprobe_comm->location_len) { | |
289 | ret = -1; | |
290 | goto end; | |
291 | } | |
292 | ||
293 | kprobe->location = location; | |
294 | ||
295 | /* Skip after the location */ | |
296 | offset += kprobe_comm->location_len; | |
297 | ||
298 | status = lttng_event_rule_kprobe_set_name(rule, name); | |
299 | if (status != LTTNG_EVENT_RULE_STATUS_OK) { | |
300 | ERR("Failed to set event rule kprobe name."); | |
301 | ret = -1; | |
302 | goto end; | |
303 | } | |
304 | ||
305 | *_event_rule = rule; | |
306 | rule = NULL; | |
307 | ret = offset; | |
308 | end: | |
309 | lttng_event_rule_destroy(rule); | |
310 | return ret; | |
311 | } | |
312 | ||
313 | enum lttng_event_rule_status lttng_event_rule_kprobe_set_location( | |
314 | struct lttng_event_rule *rule, | |
315 | const struct lttng_kernel_probe_location *location) | |
316 | { | |
317 | struct lttng_kernel_probe_location *location_copy = NULL; | |
318 | struct lttng_event_rule_kprobe *kprobe; | |
319 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
320 | ||
321 | if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !location) { | |
322 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
323 | goto end; | |
324 | } | |
325 | ||
326 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
327 | location_copy = lttng_kernel_probe_location_copy(location); | |
328 | if (!location_copy) { | |
329 | status = LTTNG_EVENT_RULE_STATUS_ERROR; | |
330 | goto end; | |
331 | } | |
332 | ||
333 | if (kprobe->location) { | |
334 | lttng_kernel_probe_location_destroy(kprobe->location); | |
335 | } | |
336 | ||
337 | kprobe->location = location_copy; | |
338 | location_copy = NULL; | |
339 | end: | |
340 | lttng_kernel_probe_location_destroy(location_copy); | |
341 | return status; | |
342 | } | |
343 | ||
344 | enum lttng_event_rule_status lttng_event_rule_kprobe_get_location( | |
345 | const struct lttng_event_rule *rule, | |
346 | const struct lttng_kernel_probe_location **location) | |
347 | { | |
348 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
349 | struct lttng_event_rule_kprobe *kprobe; | |
350 | ||
351 | if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !location) { | |
352 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
353 | goto end; | |
354 | } | |
355 | ||
356 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
357 | *location = kprobe->location; | |
358 | ||
359 | if (!*location) { | |
360 | status = LTTNG_EVENT_RULE_STATUS_UNSET; | |
361 | goto end; | |
362 | } | |
363 | ||
364 | end: | |
365 | return status; | |
366 | } | |
367 | ||
368 | enum lttng_event_rule_status lttng_event_rule_kprobe_set_name( | |
369 | struct lttng_event_rule *rule, const char *name) | |
370 | { | |
371 | char *name_copy = NULL; | |
372 | struct lttng_event_rule_kprobe *kprobe; | |
373 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
374 | ||
375 | if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name || | |
376 | strlen(name) == 0) { | |
377 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
378 | goto end; | |
379 | } | |
380 | ||
381 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
382 | name_copy = strdup(name); | |
383 | if (!name_copy) { | |
384 | status = LTTNG_EVENT_RULE_STATUS_ERROR; | |
385 | goto end; | |
386 | } | |
387 | ||
388 | free(kprobe->name); | |
389 | ||
390 | kprobe->name = name_copy; | |
391 | name_copy = NULL; | |
392 | end: | |
393 | return status; | |
394 | } | |
395 | ||
396 | enum lttng_event_rule_status lttng_event_rule_kprobe_get_name( | |
397 | const struct lttng_event_rule *rule, const char **name) | |
398 | { | |
399 | struct lttng_event_rule_kprobe *kprobe; | |
400 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; | |
401 | ||
402 | if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name) { | |
403 | status = LTTNG_EVENT_RULE_STATUS_INVALID; | |
404 | goto end; | |
405 | } | |
406 | ||
407 | kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent); | |
408 | if (!kprobe->name) { | |
409 | status = LTTNG_EVENT_RULE_STATUS_UNSET; | |
410 | goto end; | |
411 | } | |
412 | ||
413 | *name = kprobe->name; | |
414 | end: | |
415 | return status; | |
416 | } |