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