8b23d58e70aafb81e09893e37c02dc8b6a3199c6
[lttng-tools.git] / src / common / actions / snapshot-session.c
1 /*
2 * Copyright (C) 2019 Simon Marchi <simon.marchi@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/snapshot.h>
12 #include <common/payload.h>
13 #include <common/payload-view.h>
14 #include <lttng/action/action-internal.h>
15 #include <lttng/action/snapshot-session-internal.h>
16 #include <lttng/action/snapshot-session.h>
17 #include <lttng/snapshot.h>
18 #include <lttng/snapshot-internal.h>
19 #include <inttypes.h>
20
21 #define IS_SNAPSHOT_SESSION_ACTION(action) \
22 (lttng_action_get_type(action) == LTTNG_ACTION_TYPE_SNAPSHOT_SESSION)
23
24 struct lttng_action_snapshot_session {
25 struct lttng_action parent;
26
27 /* Owned by this. */
28 char *session_name;
29
30 /*
31 * When non-NULL, use this custom output when taking the snapshot,
32 * rather than the session's registered snapshot output.
33 *
34 * Owned by this.
35 */
36 struct lttng_snapshot_output *output;
37 };
38
39 struct lttng_action_snapshot_session_comm {
40 /* All string lengths include the trailing \0. */
41 uint32_t session_name_len;
42 uint32_t snapshot_output_len;
43
44 /*
45 * Variable data (all strings are null-terminated):
46 *
47 * - session name string
48 * - snapshot output object
49 *
50 */
51 char data[];
52 } LTTNG_PACKED;
53
54 static struct lttng_action_snapshot_session *
55 action_snapshot_session_from_action(struct lttng_action *action)
56 {
57 assert(action);
58
59 return container_of(
60 action, struct lttng_action_snapshot_session, parent);
61 }
62
63 static const struct lttng_action_snapshot_session *
64 action_snapshot_session_from_action_const(const struct lttng_action *action)
65 {
66 assert(action);
67
68 return container_of(
69 action, struct lttng_action_snapshot_session, parent);
70 }
71
72 static bool lttng_action_snapshot_session_validate(struct lttng_action *action)
73 {
74 bool valid = false;
75 struct lttng_action_snapshot_session *action_snapshot_session;
76
77 if (!action) {
78 goto end;
79 }
80
81 action_snapshot_session = action_snapshot_session_from_action(action);
82
83 /* A non-empty session name is mandatory. */
84 if (!action_snapshot_session->session_name ||
85 strlen(action_snapshot_session->session_name) == 0) {
86 goto end;
87 }
88
89 if (action_snapshot_session->output &&
90 !lttng_snapshot_output_validate(action_snapshot_session->output)) {
91 goto end;
92 }
93
94 valid = true;
95 end:
96 return valid;
97 }
98
99 static bool lttng_action_snapshot_session_is_equal(
100 const struct lttng_action *_a, const struct lttng_action *_b)
101 {
102 bool is_equal = false;
103 const struct lttng_action_snapshot_session *a, *b;
104
105 a = action_snapshot_session_from_action_const(_a);
106 b = action_snapshot_session_from_action_const(_b);
107
108 /* Action is not valid if this is not true. */
109 assert(a->session_name);
110 assert(b->session_name);
111 if (strcmp(a->session_name, b->session_name)) {
112 goto end;
113 }
114
115 if (a->output && b->output &&
116 !lttng_snapshot_output_is_equal(a->output, b->output)) {
117 goto end;
118 } else if (!!a->output != !!b->output) {
119 goto end;
120 }
121
122 is_equal = true;
123 end:
124 return is_equal;
125 }
126
127 static size_t serialize_strlen(const char *str)
128 {
129 return str ? strlen(str) + 1 : 0;
130 }
131
132 static int lttng_action_snapshot_session_serialize(
133 struct lttng_action *action, struct lttng_payload *payload)
134 {
135 struct lttng_action_snapshot_session *action_snapshot_session;
136 struct lttng_action_snapshot_session_comm comm = {};
137 int ret;
138 size_t size_before_comm;
139
140 assert(action);
141 assert(payload);
142
143 size_before_comm = payload->buffer.size;
144
145 action_snapshot_session = action_snapshot_session_from_action(action);
146 comm.session_name_len =
147 serialize_strlen(action_snapshot_session->session_name);
148
149 /* Add header. */
150 ret = lttng_dynamic_buffer_append(
151 &payload->buffer, &comm, sizeof(comm));
152 if (ret) {
153 goto end;
154 }
155
156 assert(action_snapshot_session->session_name);
157 DBG("Serializing snapshot session action: session-name: %s",
158 action_snapshot_session->session_name);
159
160 /* Add session name. */
161 ret = lttng_dynamic_buffer_append(&payload->buffer,
162 action_snapshot_session->session_name,
163 comm.session_name_len);
164 if (ret) {
165 goto end;
166 }
167
168 /* Serialize the snapshot output object, if any. */
169 if (action_snapshot_session->output) {
170 const size_t size_before_output = payload->buffer.size;
171 struct lttng_action_snapshot_session_comm *comm_in_payload;
172
173 ret = lttng_snapshot_output_serialize(
174 action_snapshot_session->output,
175 payload);
176 if (ret) {
177 goto end;
178 }
179
180 /* Adjust action length in header. */
181 comm_in_payload = (typeof(comm_in_payload))(
182 payload->buffer.data + size_before_comm);
183 comm_in_payload->snapshot_output_len =
184 payload->buffer.size - size_before_output;
185 }
186
187 end:
188 return ret;
189 }
190
191 static void lttng_action_snapshot_session_destroy(struct lttng_action *action)
192 {
193 struct lttng_action_snapshot_session *action_snapshot_session;
194
195 if (!action) {
196 goto end;
197 }
198
199 action_snapshot_session = action_snapshot_session_from_action(action);
200
201 free(action_snapshot_session->session_name);
202 lttng_snapshot_output_destroy(action_snapshot_session->output);
203 free(action_snapshot_session);
204
205 end:
206 return;
207 }
208
209 ssize_t lttng_action_snapshot_session_create_from_payload(
210 struct lttng_payload_view *view,
211 struct lttng_action **p_action)
212 {
213 ssize_t consumed_len;
214 const char *variable_data;
215 struct lttng_action *action;
216 enum lttng_action_status status;
217 struct lttng_snapshot_output *snapshot_output = NULL;
218 const struct lttng_action_snapshot_session_comm *comm;
219 const struct lttng_payload_view snapshot_session_comm_view =
220 lttng_payload_view_from_view(
221 view, 0, sizeof(*comm));
222
223 action = lttng_action_snapshot_session_create();
224 if (!action) {
225 goto error;
226 }
227
228 if (!lttng_payload_view_is_valid(&snapshot_session_comm_view)) {
229 /* Payload not large enough to contain the header. */
230 goto error;
231 }
232
233 comm = (typeof(comm)) snapshot_session_comm_view.buffer.data;
234 variable_data = (const char *) &comm->data;
235
236 consumed_len = sizeof(struct lttng_action_snapshot_session_comm);
237
238 if (!lttng_buffer_view_contains_string(
239 &view->buffer, variable_data, comm->session_name_len)) {
240 goto error;
241 }
242
243 status = lttng_action_snapshot_session_set_session_name(
244 action, variable_data);
245 if (status != LTTNG_ACTION_STATUS_OK) {
246 goto error;
247 }
248
249 variable_data += comm->session_name_len;
250 consumed_len += comm->session_name_len;
251
252 /* If there is a snapshot output object, deserialize it. */
253 if (comm->snapshot_output_len > 0) {
254 ssize_t snapshot_output_consumed_len;
255 enum lttng_action_status action_status;
256 struct lttng_payload_view snapshot_output_buffer_view =
257 lttng_payload_view_from_view(view, consumed_len,
258 comm->snapshot_output_len);
259
260 if (!lttng_payload_view_is_valid(&snapshot_output_buffer_view)) {
261 ERR("Failed to create buffer view for snapshot output.");
262 goto error;
263 }
264
265 snapshot_output_consumed_len =
266 lttng_snapshot_output_create_from_payload(
267 &snapshot_output_buffer_view,
268 &snapshot_output);
269 if (snapshot_output_consumed_len != comm->snapshot_output_len) {
270 ERR("Failed to deserialize snapshot output object: "
271 "consumed-len: %zd, expected-len: %" PRIu32,
272 snapshot_output_consumed_len,
273 comm->snapshot_output_len);
274 goto error;
275 }
276
277 action_status = lttng_action_snapshot_session_set_output(
278 action, snapshot_output);
279 if (action_status != LTTNG_ACTION_STATUS_OK) {
280 goto error;
281 }
282
283 /* Ownership has been transferred to the action. */
284 snapshot_output = NULL;
285 }
286
287 variable_data += comm->snapshot_output_len;
288 consumed_len += comm->snapshot_output_len;
289 *p_action = action;
290 action = NULL;
291
292 goto end;
293
294 error:
295 consumed_len = -1;
296
297 end:
298 lttng_action_snapshot_session_destroy(action);
299 lttng_snapshot_output_destroy(snapshot_output);
300
301 return consumed_len;
302 }
303
304 struct lttng_action *lttng_action_snapshot_session_create(void)
305 {
306 struct lttng_action *action;
307
308 action = zmalloc(sizeof(struct lttng_action_snapshot_session));
309 if (!action) {
310 goto end;
311 }
312
313 lttng_action_init(action, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION,
314 lttng_action_snapshot_session_validate,
315 lttng_action_snapshot_session_serialize,
316 lttng_action_snapshot_session_is_equal,
317 lttng_action_snapshot_session_destroy);
318
319 end:
320 return action;
321 }
322
323 enum lttng_action_status lttng_action_snapshot_session_set_session_name(
324 struct lttng_action *action, const char *session_name)
325 {
326 struct lttng_action_snapshot_session *action_snapshot_session;
327 enum lttng_action_status status;
328
329 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name ||
330 strlen(session_name) == 0) {
331 status = LTTNG_ACTION_STATUS_INVALID;
332 goto end;
333 }
334
335 action_snapshot_session = action_snapshot_session_from_action(action);
336
337 free(action_snapshot_session->session_name);
338
339 action_snapshot_session->session_name = strdup(session_name);
340 if (!action_snapshot_session->session_name) {
341 status = LTTNG_ACTION_STATUS_ERROR;
342 goto end;
343 }
344
345 status = LTTNG_ACTION_STATUS_OK;
346 end:
347 return status;
348 }
349
350 enum lttng_action_status lttng_action_snapshot_session_get_session_name(
351 const struct lttng_action *action, const char **session_name)
352 {
353 const struct lttng_action_snapshot_session *action_snapshot_session;
354 enum lttng_action_status status;
355
356 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name) {
357 status = LTTNG_ACTION_STATUS_INVALID;
358 goto end;
359 }
360
361 action_snapshot_session = action_snapshot_session_from_action_const(action);
362
363 if (action_snapshot_session->session_name) {
364 *session_name = action_snapshot_session->session_name;
365 status = LTTNG_ACTION_STATUS_OK;
366 } else {
367 status = LTTNG_ACTION_STATUS_UNSET;
368 }
369
370 end:
371
372 return status;
373 }
374
375 enum lttng_action_status lttng_action_snapshot_session_set_output(
376 struct lttng_action *action,
377 struct lttng_snapshot_output *output)
378 {
379 struct lttng_action_snapshot_session *action_snapshot_session;
380 enum lttng_action_status status;
381
382 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !output) {
383 status = LTTNG_ACTION_STATUS_INVALID;
384 goto end;
385 }
386
387 action_snapshot_session = action_snapshot_session_from_action(action);
388
389 lttng_snapshot_output_destroy(action_snapshot_session->output);
390 action_snapshot_session->output = output;
391
392 status = LTTNG_ACTION_STATUS_OK;
393
394 end:
395 return status;
396 }
397
398 enum lttng_action_status lttng_action_snapshot_session_get_output(
399 const struct lttng_action *action,
400 const struct lttng_snapshot_output **output)
401 {
402 const struct lttng_action_snapshot_session *action_snapshot_session;
403 enum lttng_action_status status;
404
405 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action)|| !output) {
406 status = LTTNG_ACTION_STATUS_INVALID;
407 goto end;
408 }
409
410 action_snapshot_session = action_snapshot_session_from_action_const(action);
411
412 if (action_snapshot_session->output) {
413 *output = action_snapshot_session->output;
414 status = LTTNG_ACTION_STATUS_OK;
415 } else {
416 status = LTTNG_ACTION_STATUS_UNSET;
417 }
418
419 end:
420 return status;
421 }
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