7576838650609b245f25f202ca491b3084797d50
[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 struct lttng_action_snapshot_session_comm *comm;
215 const char *variable_data;
216 struct lttng_action *action;
217 enum lttng_action_status status;
218 struct lttng_snapshot_output *snapshot_output = NULL;
219
220 action = lttng_action_snapshot_session_create();
221 if (!action) {
222 goto error;
223 }
224
225 comm = (typeof(comm)) view->buffer.data;
226 variable_data = (const char *) &comm->data;
227
228 consumed_len = sizeof(struct lttng_action_snapshot_session_comm);
229
230 if (!lttng_buffer_view_contains_string(
231 &view->buffer, variable_data, comm->session_name_len)) {
232 goto error;
233 }
234
235 status = lttng_action_snapshot_session_set_session_name(
236 action, variable_data);
237 if (status != LTTNG_ACTION_STATUS_OK) {
238 goto error;
239 }
240
241 variable_data += comm->session_name_len;
242 consumed_len += comm->session_name_len;
243
244 /* If there is a snapshot output object, deserialize it. */
245 if (comm->snapshot_output_len > 0) {
246 ssize_t snapshot_output_consumed_len;
247 enum lttng_action_status action_status;
248 struct lttng_payload_view snapshot_output_buffer_view =
249 lttng_payload_view_from_view(view, consumed_len,
250 comm->snapshot_output_len);
251
252 if (!snapshot_output_buffer_view.buffer.data) {
253 ERR("Failed to create buffer view for snapshot output.");
254 goto error;
255 }
256
257 snapshot_output_consumed_len =
258 lttng_snapshot_output_create_from_payload(
259 &snapshot_output_buffer_view,
260 &snapshot_output);
261 if (snapshot_output_consumed_len != comm->snapshot_output_len) {
262 ERR("Failed to deserialize snapshot output object: "
263 "consumed-len: %zd, expected-len: %" PRIu32,
264 snapshot_output_consumed_len,
265 comm->snapshot_output_len);
266 goto error;
267 }
268
269 action_status = lttng_action_snapshot_session_set_output(
270 action, snapshot_output);
271 if (action_status != LTTNG_ACTION_STATUS_OK) {
272 goto error;
273 }
274
275 /* Ownership has been transferred to the action. */
276 snapshot_output = NULL;
277 }
278
279 variable_data += comm->snapshot_output_len;
280 consumed_len += comm->snapshot_output_len;
281 *p_action = action;
282 action = NULL;
283
284 goto end;
285
286 error:
287 consumed_len = -1;
288
289 end:
290 lttng_action_snapshot_session_destroy(action);
291 lttng_snapshot_output_destroy(snapshot_output);
292
293 return consumed_len;
294 }
295
296 struct lttng_action *lttng_action_snapshot_session_create(void)
297 {
298 struct lttng_action *action;
299
300 action = zmalloc(sizeof(struct lttng_action_snapshot_session));
301 if (!action) {
302 goto end;
303 }
304
305 lttng_action_init(action, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION,
306 lttng_action_snapshot_session_validate,
307 lttng_action_snapshot_session_serialize,
308 lttng_action_snapshot_session_is_equal,
309 lttng_action_snapshot_session_destroy);
310
311 end:
312 return action;
313 }
314
315 enum lttng_action_status lttng_action_snapshot_session_set_session_name(
316 struct lttng_action *action, const char *session_name)
317 {
318 struct lttng_action_snapshot_session *action_snapshot_session;
319 enum lttng_action_status status;
320
321 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name ||
322 strlen(session_name) == 0) {
323 status = LTTNG_ACTION_STATUS_INVALID;
324 goto end;
325 }
326
327 action_snapshot_session = action_snapshot_session_from_action(action);
328
329 free(action_snapshot_session->session_name);
330
331 action_snapshot_session->session_name = strdup(session_name);
332 if (!action_snapshot_session->session_name) {
333 status = LTTNG_ACTION_STATUS_ERROR;
334 goto end;
335 }
336
337 status = LTTNG_ACTION_STATUS_OK;
338 end:
339 return status;
340 }
341
342 enum lttng_action_status lttng_action_snapshot_session_get_session_name(
343 const struct lttng_action *action, const char **session_name)
344 {
345 const struct lttng_action_snapshot_session *action_snapshot_session;
346 enum lttng_action_status status;
347
348 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name) {
349 status = LTTNG_ACTION_STATUS_INVALID;
350 goto end;
351 }
352
353 action_snapshot_session = action_snapshot_session_from_action_const(action);
354
355 if (action_snapshot_session->session_name) {
356 *session_name = action_snapshot_session->session_name;
357 status = LTTNG_ACTION_STATUS_OK;
358 } else {
359 status = LTTNG_ACTION_STATUS_UNSET;
360 }
361
362 end:
363
364 return status;
365 }
366
367 enum lttng_action_status lttng_action_snapshot_session_set_output(
368 struct lttng_action *action,
369 struct lttng_snapshot_output *output)
370 {
371 struct lttng_action_snapshot_session *action_snapshot_session;
372 enum lttng_action_status status;
373
374 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !output) {
375 status = LTTNG_ACTION_STATUS_INVALID;
376 goto end;
377 }
378
379 action_snapshot_session = action_snapshot_session_from_action(action);
380
381 lttng_snapshot_output_destroy(action_snapshot_session->output);
382 action_snapshot_session->output = output;
383
384 status = LTTNG_ACTION_STATUS_OK;
385
386 end:
387 return status;
388 }
389
390 enum lttng_action_status lttng_action_snapshot_session_get_output(
391 const struct lttng_action *action,
392 const struct lttng_snapshot_output **output)
393 {
394 const struct lttng_action_snapshot_session *action_snapshot_session;
395 enum lttng_action_status status;
396
397 if (!action || !IS_SNAPSHOT_SESSION_ACTION(action)|| !output) {
398 status = LTTNG_ACTION_STATUS_INVALID;
399 goto end;
400 }
401
402 action_snapshot_session = action_snapshot_session_from_action_const(action);
403
404 if (action_snapshot_session->output) {
405 *output = action_snapshot_session->output;
406 status = LTTNG_ACTION_STATUS_OK;
407 } else {
408 status = LTTNG_ACTION_STATUS_UNSET;
409 }
410
411 end:
412 return status;
413 }
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